14 2012 Schramberg (Black Forest) - NeNa Conference

th
13 Conference of Junior Neurocientists of Tübingen
NeNa
Science and Education
as Social Transforming Agents
Registration deadline:
st
October 1 2012
Invited speaker:
Miguel Nicolelis
Contact & registration:
www.neuroschool-tuebingen-nena.de
th th
November 12 - 14 2012
Schramberg (Black Forest)
Modified from Luo (2002)

13 th NeNa 2012
(,Neurowissenschaftliche Nachwuchskonferenz’ – ,Conference
of Junior Neuroscientists’)
Welcome to the thirteenth anniversary of the NeNa in Schramberg, Germany. The NeNa is an
annual conference organized by and for young scientists in neuroscience. Since its initiation
in 1999, the NeNa has turned out to be an excellent forum for young researchers to present
and discuss their scientific work besides sharing their knowledge and experiences with peers
in an interdisciplinary and intercultural environment.
This year’s NeNa topic "Science and Education as Social Transforming Agents" is aimed at
emphasizing the importance of building a bridge between science and society, and how this
interaction can be used to improve and develop society. As an example of how this can be
translated into action, we are proud to announce that Prof. Dr. Miguel Nicolelis will be giving
this year’s keynote lecture about his projects in Brazil, which focus on using science as an
agent towards social transformation of a community.
Prof. Dr. Miguel Nicolelis is a Professor at the Department of Neurobiology at Duke University
Medical Center. His work focuses mainly on brain machine interfaces and how machines can
be controlled through the use of neuronal population activity. Among the highlights of his
work, are the proof of principle experiments in which monkeys learned to control robotic
arms using their brain signals; and a novel spinal cord stimulator that eliminates paralytic
symptoms in parkinsonian mice models.
In addition, we are very glad that Tom Baden, currently a Bernstein Postdoctoral fellow at
the Centre for Ophthalmology, Universitätsklinikum Tübingen, has kindly agreed to talk as
a guest speaker about his Neuroscience teaching project in Africa.
The conference in its present form would not have been possible without the contribution and
support of various people. In particular, we would like to thank Professor Hans-Peter Thier
as the initiator and patron of the NeNa conference. We would also like to thank Professor
Horst Herbert, Dr. Katja Thieltges and Mrs. Dagmar Heller-Schmerold for supporting the
organization in various ways. Furthermore, we want to express our gratitude to the Graduate
Training Centre of Neuroscience / International Max Planck Research School Tübingen,
Centre for Integrative Neuroscience CIN, Max Planck Institute for Biological Cybernetics
and Hertie-Institute for Clinical Brain Research for their generous support.
We wish you an interesting and enjoyable stay here in Schramberg and hope that you and
your research plans benefit from your experience at NeNa 2012. Have fun!
This years organizers:
Have fun!
André Maia Chagas, Katharina Dobs, Lena Veit, Marc Junker, Pooja Viswanathan

Contents
Timetable 1
Talks 5
Abhilash Dwarakanath
Motion parallax serves as an independent cue in sound source disambiguation 6
Almut Hoffmann
Ontogeny of object permanence in the carrion crow ( Corvus corone) . . . . 7
Anette Giani
Towards multisensory awareness: Finding (neuronal) mechanisms that enable
the detection and integration of audiovisual stimuli . . . . . . . . . . . . . . 8
Ekaterina Volkova
Motion Capture of Emotional Body Language in Narrative Scenarios . . . . 9
Eliana Garcia
Can extracephalic electric currents modulate brain oscillations and behavior? 10
Evgeny Sheygal
Grasping Familiar Objects: The influence of object recognition on neural substrates
of prehension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Fabricio Lima Brasil
ERD-related BMI control depends on the integrity of the sensorimotor cortex 12
Florian Soyka
Modeling Self-Motion Perception based on the Vestibular System . . . . . . 13
Galyna Pidpruzhnykova
Laminar variability of detection thresholds in rat barrel cortex . . . . . . . . 14
Gerrit Schwesig
Pathway specific theta-gamma dynamics in the hippocampal-entorhinal circuit 15
Josue Luiz Dalboni da Rocha
DTI analysis on Alzheimer’s Patients . . . . . . . . . . . . . . . . . . . . . . 16
Katarina Matic
Quantitative Proteomics Reveals Differentially Regulated Proteins in Fmr1-
KO Mouse and its Genetic Rescue Model . . . . . . . . . . . . . . . . . . . . 17
Lena Veit
Neural correlates of abstract task-switching in carrion crows . . . . . . . . . 18
Mohammad Khazali
The effect of visual and vestibular tilt cues on the subjective visual vertical of
rhesus monkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Nicholas Del Grosso
Interpreting (M)EEG: A first look at Dynamic Causal Modeling . . . . . . . 20
Stephan Streuber
The influence of different sources of visual information on joint action performance
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
i

Thea Zander
On the trail of intuitive coherence judgments: Exploring similarities and differences
in the underlying processes of intuition and implicit memory . . . . 22
Thomas Baden
Higher Education in the Developing World: Teaching Neuroscience in Africa 23
Poster 24
ii
Agnes Kroczek
The influence of visual alcoholic stimuli on error processing depending on alcohol
consumption patterns in healthy subjects: A combined NIRS-EEG study. 25
Aleksandra Smilgin
Purkinje cells of the monkey oculomotor vermis respond to saccades as well as
to smooth pursuit initiation . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Alessandro Nesti
Human sensitivity to different motion intensities . . . . . . . . . . . . . . . . 27
Balint Nagy
Alteration of proliferation / differentiation of oligodendrocyte precursor cells
by axonal activity in the corpus callosum . . . . . . . . . . . . . . . . . . . . 28
Barbara Wirxel
Predictable visual stimuli are perceived earlier than unpredictable events . . 29
Ceren Battal
Did you know, feel that you know or guess the answer? Comparing the neural
correlates of intuitive and feeling-of-knowing responses in memory-based
inferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Chen Chih-Yang
Post-microsaccadic enhancement of slow control . . . . . . . . . . . . . . . . 31
Daniel Arnstein
Saccadic responses of Purkinje cells in the oculomotor vermis exhibit highly
idiosyncratic eye position dependencies . . . . . . . . . . . . . . . . . . . . . 32
David Jule Mack
Better but not faster: Video game players show increased performance but not
shorter reaction times in a visual search task . . . . . . . . . . . . . . . . . . 33
Elena Ilina
Effects of a novel antiepileptic drug - Retigabine - on KCNQ2 mutations associated
with epileptic encephalopathies. . . . . . . . . . . . . . . . . . . . . . 34
Florian Häußinger
Influence of static and dynamic physiological parameters on the measurement
of neural activation with functional near-infrared spectroscopy (fNIRS) . . . 35
Frederico Azevedo, Leonardo Azevedo
Effects of visual attention on neural processing in Rhesus´ V1 by simultaneous
electrophysiology and BOLD-fMRI . . . . . . . . . . . . . . . . . . . . . . . . 36
Gagan Narula
Song discrimination ability of juvenile and adult zebra finches . . . . . . . . 37
Janina Esins
Comparing the other race effect and congenital prosopagnosia using a threeexperiment
test battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Julia Veit
Layer and stimulus specific effects of basal forebrain stimulation on neural
responses in the primary visual cortex . . . . . . . . . . . . . . . . . . . . . . 39
Konstantin Hartmann
Neuronal correlates of visual working memory in the carrion crow (Corvus
corona) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Lili Feng
Molecular Characterization of a Serine Pro-tease Htra1Implicated in AMD . 41
Maike Hege
Right prefrontal cortex alpha activity related to inhibition of responses . . . 42
Marina Fridman
Looking for the path not taken: an investigation of the influence of alternative
motor plans during perceptual and value-based decisions . . . . . . . . . . . 43
Natalja Gavrilov
Rhesus monkey can switch volitionally between distinct call types . . . . . . 44
Ninja Katja Horr
Intuitive Decisional Processes in a Perceptual Discovery Task: An MEG Study. 45
Pooja Viswanathan
Task-specific color selectivity in prefrontal and parietal areas . . . . . . . . . 46
Robin Kemmler
Synaptic interations in the outer retina of the mouse . . . . . . . . . . . . . 47
Sneha Viswanath
The role of adenosine in the neurovascular coupling of the BOLD signal in
early visual cortex of non-human primates . . . . . . . . . . . . . . . . . . . . 48
Sonja Cornelsen
Neuronal correlates of online control in reaching and grasping . . . . . . . . 49
Sudarshan Sekhar
Optimization of Subretinal Electrical Stimulation to Generate Naturalistic
Spiking Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Zong-Peng Sun
Roles of different fastigial nuclei neurons in saccade direction tuning and saccadic
adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Participants 52
iii

Timetable

2
Monday, 12 th November 2012
10:15 am-12 pm Departure from Tübingen/ Station (10:30 am)
12 pm-1 pm Lunch
1 pm-3 pm Introduction Blitz
3 pm-3:30 pm Florian Soyka
Modeling Self-Motion Perception based on the Vestibular System
3:30 pm-4 pm Coffee Break & occupy rooms
4:30 pm-6:30 pm Galyna Pidpruzhnykova
7 pm Dinner
Laminar variability of detection thresholds in rat barrel cortex
Josue Luiz Dalboni da Rocha
DTI analysis on Alzheimer’s Patients
Almut Hoffman
Ontogeny of object permanence in the carrion crow (Corvus corone)
Katarina Matic
Quantitative Proteomics Reveals Differentially Regulated Proteins
in Fmr1-KO Mouse and its Genetic Rescue Model

8 am-9 am Breakfast
9 am-10:30 am Anette Giani
Tuesday, 13 th November 2012
Towards multisensory awareness: Finding (neuronal) mechanisms that
enable the detection and integration of audiovisual stimuli
Gerrit Schwesig
Pathway specific theta-gamma dynamics in the hippocampalentorhinal
circuit
Fabricio Lima Brasil
10:30 am-11 am Coffee Break
11 am-12 pm Eliana Garcia
ERD-related BMI control depends on the integrity of the sensorimotor
cortex
Can extracephalic electric currents modulate brain oscillations and
behavior?
Lena Veit
12 pm-12:30 pm Thomas Baden
12:30 pm-1:30 pm Lunch
2 pm-4 pm Poster Session
4 pm-4:30 pm Coffee Break
Neural correlates of abstract task-switching in carrion crows
Higher Education in the Developing World: Teaching Neuroscience in
Africa
5 pm-7 pm Miguel A. L. Nicolelis
7 pm-8 pm Dinner
Transforming Science - Science and Education as Social Transforming
Agents
8 pm-... pm Group Discussion
3

4
8:00 am-9 am Breakfast
Wednesday, 14 th November 2012
9:00 am-11 am Abhilash Dwarakanath
Motion parallax serves as an independent cue in sound source disambiguation
Evgeny Sheygal
Grasping Familiar Objects: The influence of object recognition on
neural substrates of prehension
Nicholas Del Grosso
Interpreting (M)EEG: A first look at Dynamic Causal Modeling
Stephan Streuber
11:00 am-11:30 am Coffee Break
The influence of different sources of visual information on joint action
performance
11:30 am-12:30 pm Discussions / "Workshops"
12:30 pm-1:30 pm Lunch
1:30 pm-3:00 pm Ekatarina Volkova
Motion Capture of Emotional Body Language in Narrative Scenarios
Thea Zander
On the trail of intuitive coherence judgments: Exploring similarities
and differences in the underlying processes of intuition and implicit
memory
Mohammad Khazali
The effect of visual and vestibular tilt cues on the subjective visual
vertical of rhesus monkeys
3:30 pm Departure to Tübingen

Talks

Talk 1
Motion parallax serves as an independent cue in sound source
disambiguation
Abhilash Dwarakanath, Cesare Parise, Jessica Hartcher-O’Brien, Marc
Ernst
Max Planck Institute for Biological Cybernetics
In the absence of dominant cues to the distance of a sound source from the observer, estimating
absolute or relative distance becomes difficult. Motion parallax may contribute to
this estimation. However, its role as an independent cue has not yet been investigated. To
address this issue, we designed an experiment that included logarithmically varying distance
of sound source along the depth plane of the observer, elimination of distance related loudness
using perceptual loudness equalization and to and fro (laterally) movement of subjects while
the sounds were generated in three conditions a simultaneous playback, sequential playback
and simultaneous playback of phase-interrupted sounds. Sequential presentation of the low
and high sound subjects showed a substantial improvement in distance estimates relative
to the baseline static condition. Improvement was also observed for the simultaneous phase
interrupted sound condition. Here we demonstrate for the first time the existence of auditory
motion parallax from lateral self- motion and show that it aids distance estimation of sound
position. Interestingly, a bias to perceive low frequency sounds as farther away was also observed.
Auditory depth perception is improved by lateral observer motion, which alters the
inter-aural difference cues available.
6

Talk 2
Ontogeny of object permanence in the carrion crow ( Corvus corone)
Almut Hoffmann, Vanessa Rüttler, Andreas Nieder
Eberhard Karls Universität Tübingen - Institute for Neurobiology
Object permanence refers to the knowledge that an object still exists when out of sight
or displaced. Many animal species develop object permanence skills in a similar sequence
as human infants, but few master the most complex aspects, such as representing invisible
displaced objects (Piagetian Stage 6). We tested six developing hand-raised carrion crows on
Piagetian object permanence and we could demonstrate that the competence of this ability
developed gradually and that the crows reached Piagetian Stage 6. The overall pattern of
the development and competence of object permanence in crows is similar to other corvid
species. The absolute ages at which corvid species pass the tests seem to be a function of
hatching-to-fledging time.
7

Talk 3
Towards multisensory awareness: Finding (neuronal) mechanisms that
enable the detection and integration of audiovisual stimuli
Anette Giani, Uta Noppeney
Max Planck Institute for Biological Cybernetics
In daily life our sensory systems continuously receive complex information from different
sensory modalities, such as vision, audition or touch. To form unified and coherent percepts
this information needs to be integrated across the various senses; a process called multisensory
integration. Multisensory information stemming from natural environments, such as market
places or busy roads, can be extremely diverse. Moreover limited processing capacities allow
only a small subset of the complex sensory information to enter awareness. Hence, two main
questions arise: Which are the (neuronal) mechanisms that enable sensory awareness? And
is perceptual awareness necessary for multisensory integration to occur? During my PhD I
used magnetoencephalography (MEG) and psychophysical measurements, trying to find some
answers to these questions, which I will be presenting during this talk.
8

Talk 4
Motion Capture of Emotional Body Language in Narrative Scenarios
Ekaterina P. Volkova, Betty J. Mohler, Heinrich H. Bülthoff
Max Planck Institute for Biological Cybernetics
We interact with the world we live in by moving in it. The interaction is versatile and includes
communications through speech and gestures, which serve as media to transmit ideas and
emotions. A narrator, be it a professional actor on the stage or a friend telling an anecdote,
expresses her ideas (the content) and feelings (the emotional colouring) through the choice
of words and syntactical structures, her prosody, facial expressions and body language. Our
present focus is on emotional body language, which became a field of intensive research several
decades ago. Before psychopsysical experiments or trajectory analysis can take place, a set
of mocap (motion capture) data has to be accumulated. This can be done with different
equipment setups and by now human motion can be captured fairly precisely at a high
frame rate. One of the major decisions for the researchers however is the choice of scenarios
according to which the actors are to perform motion. This question is especially tricky when
we deal with emotions, since the problems of sincerity and naturalness come into play. There
are several ways to induce emotions and moods in people, but for motion capture the socalled
imagination technique has been used most frequently. The actors are asked to evoke
an emotion in themselves by recalling a past event. The main drawbacks of this technique
in mocap are the following: (1) it is still impossible to ensure that the emotions are sincere
and the motion is natural and not artificial or exaggerated; (2) the emotional categories often
rapidly succeed each other in random fashion; (3) the emotional scenarios can be very abstract
and taken out of context. We have developed an experimental setup where the emotional body
language can be captured in a maximally natural yet controlled manner. The participants are
asked to imagine they are narrating a fairy-tale to children. They perform several tasks on the
text before their acting in recorded. The setup allows the actors to narrate the story at their
own pace, move freely and does not require them to learn the text by heart, yet the recorded
data can be easily extracted and processed after the motion capture session. The resulting
extracted data can then analysed for various features or used in perceptual experiments.
9

Talk 5
Can extracephalic electric currents modulate brain oscillations and
behavior?
Eliana Garcia Cossio, Matthias Witkowski,Stephen Robinson, Niels
Birbaumer, Surjo Soekadar
Eberhard Karls Universität Tübingen - Institute of Medical Psychology and
Behavioural Neurobiology
Transcranial direct current stimulation (tDCS) is a non-invasive technique influencing cognition,
motor function, learning and memory. Despite its impact in the treatment of neurologic
and psychiatric disorders, the effects of these currents on brain oscillations remained an
enigma because of the impossibility to record them simultaneously as electromagnetic noise
substantially interferes with electro- and magnetoencephalographic (EEG/MEG) recordings.
Here we introduce a novel technique to assess human neuromagnetic brain oscillations during
simultaneous application of extracephalic electric currents. We show that tDCS has polarity
dependent effects on the contingent magnetic variation (CMV), a slow cortical potential
(SCP) associated with excitability changes in the cortex during preparation and execution
of an externally cued motor task. While anodal stimulation applied to the primary motor
cortex was associated with higher amplitudes of the CMV and faster reaction times, cathodal
stimulation attenuated the CMV and resulted in slower reaction times. Sham stimulation
had no effect on CMV and reaction times. This is the first study that investigated the online
effects of tDCS on SCP providing evidence that brain oscillations and motor behavior can be
specifically and purposefully modulated through externally applied electric currents.
10

Talk 6
Grasping Familiar Objects: The influence of object recognition on neural
substrates of prehension
Evgeny Sheygal, Marc Himmelbach, Jason Martin
Eberhard Karls Universität Tübingen - Universitätsklinikum
The grasping network of the human dorsal stream is widely believed to rely solely on absolute
object properties like its size and distance. In our slow event fMRI Study we challenge this
view by comparing the BOLD signals of healthy participants grasping monocolored geometric
blocks vs. familiar everyday objects. Among the brain areas showing significant signal
differences between the conditions we find the occipitotemporal cortex as well as the anterior
intraparietal sulcus (aIPS) and the anterior supramarginal gyrus (aSMG). These findings are
consistent with a small number of similar studies. Furthermore we conducted a control block
design experiment to make sure that the resulting activations are not caused by passive viewing
of the objects. We conveyed a region of interest analysis based on the activation peaks
of the grasping experiment, and discovered no significant differnces for viewing familiar vs.
geometric objects in these areas. Conclusively we hypothesize that object recognition plays
an important role in simplifying prehension control during everyday grasping actions.
11

Talk 7
ERD-related BMI control depends on the integrity of the sensorimotor
cortex
Fabricio Lima Brasil, Marco Rocha Curado, Matthias Witkowski, Eliana
Garcia Cossio, Ander Ramos Murguialday, Niels Birbaumer, Surjo
Raphael Soekadar
Eberhard Karls Universität Tübingen / Institute of Medical Psychology and
Behavioral Neurobiology
Introduction: An alpha variant wave called mu (µ) can be found over the motor cortex that
is reduced with movement, or the intention to move - which is called event-related desynchronization
(ERD). The thalamocortical network plays an important role in the generation of
alpha activity. Hypothesis: ERD-related Brain Machine Interface (BMI) control depends on
the integrity of the sensorymotor cortex. Background: Several studies show that sources of
alpha ERD would be distributed in primary sensorimotor (M1-S1) and supplementary motor
(SMA) areas. Electrode C3/C4 is placed over the hand area (EEG, 10/20 system). Methods:
39 severely affected chronic stroke patients (18 mixed lesion, 21 subcortical lesion) underwent
a 4-weeks of daily BMI training. Two sessions were compared: The better of first 2 and last
2 days of the ipsilesional channel C. ERD was calculated using Matlab and statistics with
SPSS. Results: Paired samples t-test showed no difference between groups comparing the
beginning and the end of the training. Independent samples t-test showed that patients with
cortical/subcortical lesions showed significant difference on the pre (p = .004) and on the
post (p = .005) measurements. Only four patients improved more than 10% over training.
All had the cortex intact and the thalamus affected. Conclusion: Our results suggest that
ERDs generation is directly related with integrity of the sensorimotor cortex. Integrity of
thalamus has a minor effect in the improvements of ERDs.
12

Talk 8
Modeling Self-Motion Perception based on the Vestibular System
Florian Soyka
Max Planck Institute for Biological Cybernetics
Understanding self-motion perception is important, e.g., for developing perception-based diagnostics
for patients suffering from vestibular disorders, or for improving the realism of
motion simulation. Here, self-motion perception was quantified with direction discrimination
thresholds and reaction times for translational and rotational motions. Models based on the
physiology of the vestibular system, which plays a central role in sensing inertial motions, are
introduced that are able to describe psychophysical measurements. The Max Planck Institute
CyberMotion Simulator was used to measure thresholds for 9 translational and 9 rotational
motion stimuli with varying acceleration profiles. A forced-choice paradigm was used in which
blindfolded participants had to judge the directions of motions with varying peak accelerations
until the threshold acceleration was found that yielded a predefined performance level
(e.g. 75% correct answers). A similar task was used with supra threshold accelerations in order
to measure reaction times for 4 translational and 4 rotational motions. The results show that
thresholds and reaction times depend on the actual shape and duration of an acceleration
profile. The proposed models were fit to threshold measurements and are able to describe
thresholds for arbitrary motion profiles. In accordance with previous research, the estimated
model parameters indicate that velocity storage does not influence rotational thresholds. For
translational motions, it was found that the sensitivity to jerk (the time derivative of acceleration)
is higher than previously assumed. Furthermore, the models identified based on
threshold measurements are able to predict differences between reaction times for varying motion
profiles measured in another group of participants. This is an important finding, because
it links reaction times and threshold measurements. Therefore, future research will be able to
identify self-motion perception models based on reaction times. This is advantageous, since
reaction time tasks are more convenient for participants and require fewer trials, allowing for
faster testing.
13

Talk 9
Laminar variability of detection thresholds in rat barrel cortex
Galyna Pidpruzhnykova, Dominik Brugger
Eberhard Karls Universität Tübingen
Cortical microstimulation is a prospective technology for restoring lost sensory functions, like
vision in blind patients. Optimization of microstimulation techniques involves increasing the
spatial resolution of applied signals, which can be achieved by using smaller intensities for
the stimulation. Here we investigated the effect of patterns of evoked activity on the percept
in rat barrel cortex at different cortical depths. Rats were chronically implanted with sixteenmicroelectrode
silicon probes and trained to respond to the stimuli by licking a water tube.
Stimuli were delivered to eight different depths of rat barrel cortex ranging from 0.2 mm to
1.6 mm. The obtained spatial profile of detection thresholds showed that the most sensitive
cortical layer to microstimulation is layer IV of rat primary somatosensory cortex. Analysis of
local field potentials showed temporally concentrated activation patterns for layers with lower
detection thresholds, while for less sensitive layers the evoked activity was spatially combined
and temporally spread, but this issue needs further investigation. The present results thus
suggest application of microstimulation to cortical layer IV for maximally effective cortical
stimulation.
14

Talk 10
Pathway specific theta-gamma dynamics in the hippocampal-entorhinal
circuit
Gerrit Schwesig, Anton Sirota
Eberhard Karls Universität Tübingen
Brain state dependent oscillatory neuronal dynamics as reflected in the local field potentials
(LFPs) have been proposed to fascilitate and organize information transfer within and across
brain structures. Detailed analysis of oscillatory interactions within neocortex and many
subcortical structures however is often hampered by the fact that LFPs are volume averaged
signals and local cytoarchitectonic complexities therefore often prevent sufficiently clear mapping
of LFP sources to anatomical structures. In contrast, the hippocampal formation and
its primary input-output partners the lateral and medial entorhinal cortices (LEC and MEC)
lend themselves as a model system for this question because of their comparatively simple and
spatially well defined circuit architecture including several unidirectional pathways targeting
nonoverlapping dendritic compartments in Dentate Gyrus, CA3 and CA1. We used simultaneous
high density recordings of local field potentials in all of the mentioned areas in freely
moving rats to assess local and interregional dynamics in the theta and gamma range across
layers of MEC and LEC cortex as well as subfields CA1, CA3 and Dentate Gyrus of Hippocampus.
First we demonstrate different distributions of gamma rhythms between MEC and
LEC. Furthermore we are able to show entorhinal-hippocampal pathway specific gamma synchronization,
which emerges in different entorhinal layers, exhibits distinct frequency ranges
and tends to occur at specific phases of ongoing theta oscillation. These specific mappings
between oscillatory dynamics and well defined anatomical pathways may support the organization
of hippocampal processing during encoding and retrieval processes.
15

Talk 11
DTI analysis on Alzheimer’s Patients
Josue Luiz Dalboni da Rocha, Ivanei Bramati, Balint Varkuti, Fernanda
Moll, Jorge Moll, Ranganatha Sitaram
Eberhard Karls Universität Tübingen
The current treatments for Alzheimers Disease (AD) are only able to slow the progression
of mental deterioration, making early diagnosis essential to promote better quality of life for
patients (Kalus, 2006). The worlds main standard criteria for the clinical diagnosis of AD are
the NINCDS-ADRDA Alzheimer’s Criteria, from 1984. These criteria require neuropsychological
and histological tests for the detection of AD. In the most recent years, anatomical,
physiological and biochemical parameters which reflect specific features of disease have been
incorporated to the diagnostic criteria. In terms of imaging based diagnosis, the Diffusion
Tensor Imaging (DTI) is highly promising, whose development may provide much earlier evidences
of the disease than the neuropsychological symptoms. DTI is a magnetic resonance
imaging (MRI) technique to estimate the brain connectivity, providing connectivity atlas.
In this work, AD and MCI patients are analyzed under the DTI technique in order to find
patterns of abnormality in the brain connectivity, in contrast to control volunteers. To select
these classification patterns, Graph Theory approaches are used as features. After the
selection of a Region of Interest (ROI), the Support Vector Machine is applied as classifier.
16

Talk 12
Quantitative Proteomics Reveals Differentially Regulated Proteins in
Fmr1-KO Mouse and its Genetic Rescue Model
Katarina Matic ,Karsten Krug, Emily Osterweil, Mark Bear, Boris Macek
Eberhard Karls Universität Tübingen - Interfaculty Institute for Cell Biology
Fragile X syndrome (FXS) is the most common cause of heritable mental retardation, as well
as leading identified cause of autism. It is caused by transcriptional silencing of the FMR1 gene
that encodes the fragile X mental retardation protein (FMRP). Nevertheless, pathogenesis of
the disease is unknown. Exaggerated metabotropic glutamate receptor (mGluR5) signaling
is a hallmark of the fragile X syndrome. Reversal of many FXS-related abnormalities can be
achieved at the molecular level upon treatment of Fmr1 KO mice with mGluR5 antagonists
such as MPEP and Fenobam. The Bear lab has recently shown that Fmr1 mutant mice with
reduced mGluR5 expression (Fmr1 KO/mGluR5-het cross) are able to correct most of the
features of the disorder relevant to the human FXS phenotype. We used quantitative mass
spectrometry-based proteomics to perform global comparison of protein levels in isolated
hippocampi of the WT, Fmr1 KO and Fmr1 KO/mGluR5-het cross mice. Two orthogonal
quantitative proteomics approaches were applied - stable isotope-labeled (SILAC) mouse
brain tissue as an internal standard for quantitation and label-free quantitation. We detected
more than 8,000 and quantified over 4,000 proteins across the three analyzed genotypes. Preliminary
results reveal high individual variability in measured protein levels between analyzed
mice, but also identify more than 100 proteins significantly changed in the Fmr1 KO mice.
mRNA of many of these proteins has recently been detected as a target of FMRP. Interestingly,
some significantly regulated proteins were changing more than 2 fold between Fmr1-KO
and Fmr1-KO/mGluR5 het KO. However, there was no overlap between statistically significant
ratios. High ratio variability and relatively low overlap between significantly regulated
proteins likely resulted from relatively few significant outliers in analyzed mice. None the less,
proteins that are significantly changing between Fmr1-KO and Fmr1-KO/mGluR5 het KO
may play a role in molecular mechanisms of genetic rescue.
17

Talk 13
Neural correlates of abstract task-switching in carrion crows
Lena Veit, Andreas Nieder
Eberhard Karls Universität Tübingen - Institute for Neurobiology
Even though they lack a layered neocortex, birds, particularly corvids, have been shown to
match or surpass primates in many cognitive tasks. The associative forebrain areas underlying
these abilities evolved independently from different anatomical structures of the telencephalic
pallium in birds and mammals. Therefore, the investigation of the neuronal mechanisms
underlying cognitive functions in corvid birds will help to decipher the general principles and
evolutionary constraints for the design of highly cognitive vertebrate brains. To study the
neural underpinnings of executive control functions in corvids, we trained two carrion crows
(Corvus corone) on an abstract rule-switching task which required them to flexibly apply
rules to match two identical or two different visual images, respectively. They mastered this
delayed rule-switching task with two sets of rule-cues from different modalities and novel
sets of sample images each day (average performance 88.8% correct). We next recorded the
activity of single neurons in the NCL (nidopallium caudolaterale), a proposed avian analogue
of the mammalian prefrontal cortex (PFC). We found single NCL-neurons which showed
elevated activity to one of the two behavioral rules. To control whether cells were merely
responding to sensory properties of the rule cue, each rule (same or different) was instructed
using one of two rule cues from different modalities. Many of the neurons encoded only the
behavioral rule, abstracting over different sample images and the modality of the rule cue.
In trials when the birds made an error, rule coding was weaker or even reversed, suggesting
that the activity of the recorded neurons was relevant to the birds ´ behavior on a trial-by-trial
basis. This represents, to our knowledge, the first combined recording of behavior and single
unit activity in awake behaving corvids, introducing crows as a promising new model to study
the neuronal basis of high-level cognition. The rule-coding NCL neurons resemble abstract
rule neurons found in the primate PFC using very similar paradigms. Thus, there seems
to be similar encoding of the task by rule-selective neurons in two functionally equivalent
associative forebrain areas of different evolutionary origin. This suggests that animals which
are able to learn this cognitively demanding task found similar neurophysiological solutions
through convergent evolution.
18

Talk 14
The effect of visual and vestibular tilt cues on the subjective visual
vertical of rhesus monkeys
Mohammad Khazali, Nabil Daddaoua, Peter Dicke, Peter Thier
Hertie-Institute for Clinical Brain Research
Our perception of the world as upright is reliably stable despite frequent changes of the
orientation of head and body. This is the result of an ecologically adequate reinterpretation
of the orientation of the retinal image in the light of visual, vestibular and somatosensory
information. The subjective visual vertical (SVV) is a measure of the percept visual upright.
The SVV of human subjects roll tilted relative to gravity shows slight deviations from the
ideal of a fully tilt-independent visual percept, although reports on the direction of this
deviation vary for small static body roll tilts (

Talk 15
Interpreting (M)EEG: A first look at Dynamic Causal Modeling
Nicholas A. Del Grosso, Woosang Cho, Leonhard Läer
Eberhard Karls Universität Tübingen - Institute of Medical Psychology
Neural processes that underlie behavior are characterized between information passing between
cell populations, not only by the singular activation of populations themselves. To
model cognitive processes, causal connectivity models between neural sources are necessary.
Dynamic Causal Modeling (DCM) is a Bayesian modeling framework that can be used to test
causal relationships between neural sources. Unlike the sensor-driven analyses normally done
in electrophysiology research, DCM and the Jenson neural mass model offer an opportunity
for noninvasive electrophysiologists to generate and test theories of brain function while still
playing on the strengths of whole-brain noninvasive electrophysiology. In our pilot study, we
replicated the results of an auditory mismatch electroencephalography (EEG) study done by
Garrido et al in 2008 showing that mismatch negativity signals are brought on by a combination
of adaptation within the primary auditory cortex and top-down model adjustment
from the superior temporal gyri and inferior frontal gyri. Further, we show how the Bayesian
framework of DCM allows us to add in magnetoencephalography (MEG) data to produce
stronger evidence for specific cognitive models.
20

Talk 16
The influence of different sources of visual information on joint action
performance
Stephan Streuber
Max Planck Institute for Biological Cybernetics
Humans are social beings and they often act jointly together with other humans (joint actions)
rather than alone. Successful joint action requires the understanding and the coordination
of ones own actions with another persons actions. The research attempts to advance our
knowledge about joint action coordination by extending existing research in two novel and
important ways. First, prominent theories of joint action agree on visual information being
critical for successful joint action coordination but are vague about the exact source of visual
information being used during a joint action. However, in a real life interaction several sources
of visual information exist which inform an interaction partner about the ongoing course of
the interaction (e.g. visual information about objects, tools, other persons). Knowing which
sources of visual information are used, however, is important for a more detailed characterization
of the functioning of action coordination in joint actions. Second, previous studies
investigating the role of visual information in social settings often constrain the experimental
tasks to artificial laboratory settings. To examine joint action mechanisms under realistic
conditions I devised experimental tasks that allowed a close-to-natural joint action. As a
result the perceptual and motor components of the experimental tasks were less constrained
allowing for a more natural interaction compared to previous studies. The current research
examines the importance of different sources of visual information on joint action coordination
under realistic settings. In three studies I examined the influence of different sources
of visual information (Study 1), the functional role of different sources of visual information
(Study 2), and the effect of social context on the use of visual information (Study 3) in a
table tennis game. The results of these studies revealed that (1) visual anticipation of the
interaction partner and the interaction object is critical in natural joint actions, (2) different
sources of visual information are critical at different temporal phases during the joint action,
and (3) the social context modulates the importance of different sources of visual information.
In sum, this work provides important and new empirical evidence about the importance of
different sources of visual information in close-to-natural joint actions.
21

Talk 17
On the trail of intuitive coherence judgments: Exploring similarities and
differences in the underlying processes of intuition and implicit memory
Thea Zander, Annette Bolte, Jan Born, Thomas Goschke, Kirsten G.
Volz
Werner Reichard Centre for Integrative Neuroscience
So far, the scientific community did not agree upon a generally accepted definition of intuition.
Although there are many different approaches to define intuition, some characteristic features
can be found in all the definitions, thereby functioning as minimal definition of intuition
(Glöckner & Wittemann, 2010). Mostly, intuitive decision making is considered to be a nonconscious
process exerting a positive influence on people’s behavior by drawing on implicitly
acquired knowledge and resulting in some sort of signal, feeling or interpretation. Superficially,
at least, this minimal definition of intuition resembles that of implicit memory. Implicit
memory phenomena are often described as processes that enable a facilitation of remembering
and identification due to a preceding involuntary encoding of the stimulus (Schacter, 1992).
Accordingly, the following key questions arise: Is establishing a clear demarcation between
intuition and implicit memory feasible? If so, what are the distinguishing factors that are
not immediately apparent? We conducted an fMRI study addressing exactly this question.
The paradigm used was a semantic coherence task (Bolte & Goschke, 2005; Bowers et al.,
1990), where we additionally implemented a priming condition to prompt implicit memory
processing. Consequently, participants attent an fMRI experiment, in which intuition and
implicit-memory related tasks have both to be completed. Hence, it is possible to compare
the same participants on basis of the same material. Preliminary behavioural and fMRI results
will be presented at the NeNa.
22

Talk 18
Higher Education in the Developing World: Teaching Neuroscience in
Africa
Thomas Baden, Godino Prieto , Laura Lucia
Eberhard Karls Universität Tübingen
Racing developments in transportation and information technology are transforming our
planet into one global community. But this globalization does not benefit everybody equally.
Despite traditional geo-political barriers waning, in many poorer areas of the world access to
higher education and current scientific progress is still a scarce and valuable resource. Pivotal
to long-term success and stability in these societies is the presence of a group of highly
trained local knowledge workers with a broad outlook. Overcoming global inequality through
education, as well as local empowerment has long been established as worldwide development
goals; however, most existing projects focus at primary and secondary education, neglecting
the role of the tertiary tier. Scientific education is pivotal to the ability of societies to innovate,
move forward and integrate with the global information society. To date, most developing
nations need to import their solutions, innovations and patents from abroad, while losing
their most capable minds to Western universities and the knowledge economy beyond their
borders. Providing top-level education to local elites in their home country is key to enabling
developing societies to take their futures into their own hands and become valuable partners
in the worldwide production of knowledge. To address this issue we launched a Neuroscience
teaching project at Kampala International University (KIU), Uganda in autumn 2011 - the 1st
of its kind in Africa. With generous support from companies as well as nonprofit organizations,
we were able to provide up-to-date scientific knowledge and equipment to a selected group of
students from the region. We linked up current research agendas with locally relevant issues
and conveyed key strategies in neuroscientific research, highlighting how top-level scientific
research can be performed locally with limited budget. Following successful completion of
this pilot project we secured further funding towards annual repetition and expansion of the
course for the years to come. But inequality exists in all areas of higher education. To surpass
the limits of personal expertise we actively seek to promote and publicize our approach to
motivated individuals in other disciplines.
23

Poster

Poster 1
The influence of visual alcoholic stimuli on error processing depending on
alcohol consumption patterns in healthy subjects: A combined NIRS-EEG
study.
Agnes Kroczek, Florian Häußinger, Andreas J. Fallgatter, Ann-Christine
Ehlis
Eberhard Karls Universität Tübingen
In this study error processing was assessed by EEG recordings of event-related potentials
(ERP) simultaneously to the measurement of the hemodynamic response using Near-Infrared
Spectroscopy (NIRS). The simultaneous measurement combines the high temporal resolution
provided through EEG with the enhanced spatial resolution of cortical structures gained by
NIRS. The evaluation of own performance (action monitoring) and especially error-processing
is fundamental to decision making processes. Deficiencies in decision making are prominent
for substance abuse disorders like alcoholism. The error related negativity (ERN) and the
error-positivity (Pe) are ERPs associated with error processing altered in alcoholic patients.
This study revealed differences in error processing even in a healthy population depending on
the alcohol consumption patterns. A modified Eriksen Flanker Task was used to prompt error
commission while alcoholic and nonalcoholic beverages were depicted in order to examine the
influence of alcohol-associated cues on error processing. Compared to light social drinkers,
heavy social drinkers exhibited diminished ERN amplitudes. This difference was even more
pronounced in trials where a visual alcoholic cue preceded error commission. Differences
with the same tendency were reported in studies investigating error monitoring in alcoholics
compared to healthy controls. This preliminary data indicates alterations in neural activation
patterns during error processing as a possible marker for a higher risk to develop a substance
abuse disorder.
25

Poster 2
Purkinje cells of the monkey oculomotor vermis respond to saccades as
well as to smooth pursuit initiation
Aleksandra Smilgin, Peter W. Dicke, Peter Thier
Hertie-Institute for Clinical Brain Research
Saccades and smooth pursuit eye movements (SPEM) are two types of goal directed eye movements
whose kinematics differ profoundly, a fact that may have contributed to the notion that
the underlying neuronal substrates may be separated to a large extent. By the same token,
early work on the oculomotor role of the cerebellum seemed to suggest that also this part
of the brain might dedicate distinct modules to the two types of goal directed movements,
namely the flocculus/ paraflocculus to SPEM and the oculomotor vermis (OMV) to saccades.
Yet, it became clear very soon that lesions of the OMV not only impair saccades but also
the initiation of SPEM and that one may find saccade as well as SPEM related Purkinje
Cell simple spikes (PC SS) responses in the OMV. Moreover, the early work by Suzuki and
Keller (J. Neurophysiol. 1988) seemed to indicate that at least some PCs are sensitive to
both saccades and SPEM, a puzzling finding in view of the very different kinematic demands
of the two. We set out to compare the preferences of so far 80 eye movement related PC
SS units recorded from the OMV for saccades and SPEM. Out of these, 76 (95%) exhibited
significant responses to both saccades and SPEM initiation. In accordance with previous observations,
individual PCs responses showed highly idiosyncratic patterns (eg. bursts, pauses,
burst-pause sequences etc.) which were similar for the saccades and SPEM in roughly half
(42,5%) of the sample neurons. We have previously demonstrated that even the responses
of individual SPEM related PCs allow a reasonable description of SPEM initiation with eye
velocity being the major kinematic variable reflected in the discharge (Dash et al., Cereb.
Cortex 2012). In order to figure out if the same holds for saccades, we fitted the responses
of individual PCs with a linear model with eye position, velocity and acceleration as independent
variables. Independent of the type of eye movement, eye position and velocity were
able to explain a substantial amount of the discharge variance. Yet, eye velocity sensitivity
was substantially higher for SPEM, thereby compensating for the much lower eye velocities.
This finding suggests that OMV PC SS might deploy signals primarily used to optimize eye
movements in the face of viscous forces.
Acknowledgement: This work was supported by the European commission; Marie Curie Initial
Training Network, contract number PITN-GA-2009-238214
26

Poster 3
Human sensitivity to different motion intensities
Alessandro Nesti, Karl Beykirch, Paolo Pretto, Heinrich H. Bülthoff
Max Planck Institute for Biological Cybernetics
Sensory information processes leading to human self-motion perception have been modelled
in the past in terms of visual and inertial stimulations and their interactions. The models,
validated through many psychophysical experiments, rely on the assumption that our sensitivity
to supra-threshold self-motion is not affected by motion intensity. In other words,
the relationship between motion stimulus intensity and human sensitivity to motion is assumed
to be linear. However, recent studies have shown that this relationship is non-linear,
in particular at higher motion intensity. Therefore, the implementation of nonlinearities in
the computational models of human motion perception would increase their accuracy over a
wider range of motion stimulus intensity. Here we test human sensitivity for sinusoidal yaw
rotation in darkness at frequencies of 0.5 Hz and 1 Hz and velocity amplitudes ranging between
0 and 90 deg/s. In a two interval force choice experimental paradigm, subjects undergo
two consecutive rotations in the same direction for each trial. One of these movements is
repeated unchanged in every trial, while the other systematically varies in amplitude. Subjects
are asked to report after each trial which one of the two movements was stronger. An
adaptive staircase adjusts the motion for every trial to identify the smallest detectable change
in stimulus intensity (differential threshold). Results show a power law relationship between
differential thresholds and stimulus intensity, meaning that sensitivity decreases as motion
becomes stronger. No frequency effect is observed. These findings are of particular interest for
the field of vehicle motion simulation, where knowledge about self-motion perception is widely
exploited to overcome the physical limitations of motion-based simulators. Furthermore, the
identification of perceptual nonlinearities in multisensory stimulation will guide future work
into understanding the neural mechanisms responsible for self-motion perception.
27

Poster 4
Alteration of proliferation / differentiation of oligodendrocyte precursor
cells by axonal activity in the corpus callosum
Bálint Nagy, Maria Kukley
Werner Reichardt Centre for Integrative Neuroscience
Neuron-glial antigen 2 (NG2) expressing oligodendrocyte precursor cells (OPCs) differentiate
into myelinating oligodendrocytes during central nervous system (CNS) maturation. However,
OPCs are present and remain proliferative in the adult CNS. Whether these remaining
OPCs are responsible only for myelination during adulthood or if they have some additional
functions in the adult CNS is not known. In the CNS, including the corpus callosum
OPCs receive glutamatergic synaptic input from axons. In vitro culture studies show that the
proliferation and differentiation of OPCs are modified by activation of 2-amino-3-(3-hydroxy-
5-methyl-isoxazol-4-yl)propanoic acid (AMPA)-sensitive glutamate receptors. Therefore it’s
possible that the proliferation and / or differentiation of OPCs are directly regulated by the
glutamate release from callosal axons through AMPA receptors. Nevertheless, this has not
been shown in in vivo studies. In my work I use the combination of in vivo electrophysiology,
ex vivo electrophysiology (whole cell patch clamp from OPCs in brain slices) and immunohistochemistry
(IHC) to demonstrate if the axonal activity modifies the proliferation and
differentiation of OPCs in mice. I stimulated the axons in vivo in the corpus callosum with
chronically implanted electrodes to increase the glutamatergic release onto the OPCs. I have
recorded extracellular field potentials both from anesthetized and freely moving animals to
show that the stimulation is functioning and triggers action potentials through the corpus
callosum. The stimulation paradigm I used caused a large increase in myelination, especially
in the cortex. However, the OPCs´ number did not change in the corpus callosum, although
it increased in the cortex with this stimulation paradigm. It has been shown that ex vivo
the OPCs´ synapses undergo activity dependent modifications. The long term effects of increased
glutamatergic synaptic input on the OPCs´ glutamate receptor-properties have not
been tested. The synaptic AMPA receptor properties and the proliferation of these cells are
both regulated by the activity of the axons. That would mean that the AMPA receptor properties
differ in the different proliferative states. With the use of whole cell patch clamp I will
be able to test this hypothesis.
28

Poster 5
Predictable visual stimuli are perceived earlier than unpredictable events
Barbara Wirxel, Axel Lindner
Hertie-Institute for Clinical Brain Research
How is it possible that we timely react to visual events despite the significant processing
delays within the visual system? This delay is estimated to be already about 100ms in higher
visual areas, a delay which is relevant if one needs to initiate fast reactions, such as catching a
ball in flight or initiating escape. To compensate such delays the sensorimotor system employs
predictive mechanisms. Yet, it is currently unclear whether delay compensation already occurs
on a strictly perceptual level. Hence, we tested whether predictability of a visual stimulus
affects the time of perceived stimulus onset. Specifically, we hypothesized that predictable
visual stimuli have an earlier perceived onset compared to non-predictable stimuli. We tested
our hypothesis in a psychophysical experiment, in which we initially screened 34 subjects in a
dual task that engaged temporal interval judgements. In the middle of a black screen streams
of individual letters were presented. Each letter was presented for 300ms with a 1000ms
default interval between letters. The sequence of letters was either in alphabetic order and
thus predictable or, alternatively, the last letter of a sequence was chosen at random and
thus not predictable. In each trial subjects had to indicate whether or not the last letter
agreed with the alphabetic order. Moreover, subjects had to estimate whether the duration
of the last interval, which was of varying length, was either longer or shorter as compared
to the preceding intervals of 1000ms duration. Varying the length of the last interval allowed
us to estimate the point of subjective equivalence (PSE) between intervals. As we expected
predictable letters to be perceived earlier, the PSE should be larger in predictable sequences
than the PSE in non-predictable ones. Since our experiment required precise timing we applied
rather strict exclusion criteria to both trials and subjects. For the 10 subjects that survived
these criteria there was a significant shift of the PSE towards larger values for predictable
sequences (median shift: 33.3 ms; p=0.043). Hence, our findings show that predictable visual
stimuli are in fact perceived earlier than non-predictable ones. This suggests that even the
perceptual system is compensating for delays in sensory information processing, allowing us
to establish a timely percept of our environment.
29

Poster 6
Did you know, feel that you know or guess the answer? Comparing the
neural correlates of intuitive and feeling-of-knowing responses in
memory-based inferences
Ceren Battal, Hanna Fechner, Lael Schooler, Kirsten Volz
Werner Reichardt Centre for Integrative Neuroscience
How do people make decisions when time is limited and information is scarce? One suggestion
is by using simple heuristics. The recognition heuristic (RH) is a decision-making strategy
that uses recognition to make inferences from one’s memory about the environment. This is
an ecologically rational strategy, when considering binary-choice tasks, where one object is
recognized and another is not, resulting in a higher gain of inference on the recognized object.
Phenomenological data has revealed that people report to rely on a feeling of knowing (FOK)
when their decisions follow the RH (Volz et al., 2006, 2010). Feeling of knowing has been a
research topic since the mid-sixties and is conceived of as a reliable metacognitive state in
which the exact information cannot be recalled but a sense of knowing (the correct answer) is
experienced. Thus, in studies on metacognitive judgments in the memory domain, as well as
in studies on heuristic decision making, people report relying on a FOK the correct answer.
To test whether decision processes with different/characterized by different phenomenological
states are the same or different, we compared their neural correlates.
30

Poster 7
Post-microsaccadic enhancement of slow control
Chih-Yang Chen, Ziad M. Hafed
Werner Reichardt Centre for Integrative Neuroscience
Active sensation poses unique challenges to sensory systems because moving the sensor necessarily
alters the input sensory stream. Sensory input quality is additionally compromised
if the sensor moves rapidly, as during rapid eye movements, making the period immediately
after the movement critical for recovering reliable sensation. Here, we studied this immediate
post-movement interval for the case of tiny microsaccades during fixation, which rapidly jitter
the "sensor" exactly when it is being voluntarily stabilized to maintain clear vision. We characterized
retinal-image slip in monkeys immediately after tiny microsaccades, by analyzing
post-movement ocular drifts. We observed enhanced slip velocity by up to 28% relative to
pre-microsaccade levels, and for up to 50 ms after movement end. Moreover, we employed a
technique to trigger full-field image motion contingent on real-time microsaccade detection,
and we used the initial ocular following response to this motion as a proxy for changes in early
visual motion processing caused by microsaccades. When the full-field image motion started
during microsaccades, ocular following was strongly suppressed, consistent with detrimental
retinal effects of the movements. However, when the motion started after microsaccades, there
was up to 73% increase in ocular following speed, suggesting an enhanced motion sensitivity.
These results suggest that the interface between even the smallest possible saccades and
"fixation" includes a period of faster-than-usual image slip, as well as an enhanced responsiveness
to image motion, and that both of these mechanisms need to be considered when
interpreting the pervasive neural and perceptual modulations frequently observed around the
time of microsaccades.
31

Poster 8
Saccadic responses of Purkinje cells in the oculomotor vermis exhibit
highly idiosyncratic eye position dependencies
Daniel Arnstein, A. M. Friemann, P. W. Dicke, P. Thier
Hertie-Institute for Clinical Brain Research
Many Purkinje cells (PCs) in the oculomotor vermis (OMV) of the monkey cerebellum exhibit
saccade-related bursts or pauses of their simple spike (SS) discharge, signals thought to play
a central role in the fine-tuning of saccades. There are two reasons to ask if these saccaderelated
responses are orbital position dependent. 1. The OMV receives substantial input
from parietal and frontal areas involved in the planning and execution of saccades via the
dorsal pontine nuclei. In parietal area LIP, and probably also other cortical eye fields, neurons
discharge bursts for saccades to a particular location in retinal coordinates, but this discharge
is scaled by a gain factor whose size depends linearly on the starting position of the eyes.
These "gain fields" have been proposed to play an important role in the transformation of
spatial coordinates between different reference frames. As the OMV has been implicated in
the temporal control of saccades rather than in the spatial coding, gain fields may no longer
be necessary and one might expect that gain modulation is eliminated along the cerebrocerebellar
pathway. 2. On the other hand, the execution of the saccade plan requires that the
motor commands controlling the eye muscles take eye position-dependent forces exerted by
the oculomotor plant into account. Anecdotal observations suggest that the SS discharge of
OMV PCs might compensate for these forces. In order to test if the SS discharge of PCs in
the monkey OMV exhibits orbital position dependency, we recorded a preliminary sample of
PCs while the animals performed fixed-vector saccades, guided by visual targets, from one of
nine eye starting positions in a 20°x20°grid. More than three-quarters of the SS responses of
PCs were saccade-related, and more than half of the saccade-related PCs were modulated by
eye starting position, even when saccade metrics were included as regressors of no interest in
order to account for subtle differences in saccade metrics between the starting positions. Eye
starting position also influenced the baseline firing rate in about one-third of the PCs, but
even when these neurons were excluded, almost half of PCs showed eye position dependency.
However, the eye position dependencies exhibited by PCs were highly idiosyncratic. Only a
few PCs showed planar gain fields reminiscent of those reported in LIP, whereas other PCs
showed a highly irregular eye position dependency with no obvious structure.
32

Poster 9
Better but not faster: Video game players show increased performance but
not shorter reaction times in a visual search task
David Jule Mack, Helene Wiesmann, Uwe J. Ilg
Hertie-Institute for Clinical Brain Research
Nowadays, video games are an omnipresent medium. A survey among teenagers showed that
60% are consuming video games on a daily basis. The ramifications of these games remain
unclear. Negative effects like increased aggressive behavior have been shown as well as beneficial
outcomes like generally faster reaction times (RTs). In our own study we correlated video
game consumption to shorter eye movement RTs. As a follow-up study, we now posed the hypothesis
that this decrease is due to faster attentional processing, rather than an adjustment
of the motor program. We used Nakayama’s visual search task, where test persons (TPs)
have to report the presence and orientation of an oddball, to test our hypothesis. By varying
the cue lead time (CLT) in respect to the search array, the CLT with the TP’s maximum
detection performance can be used as measure of speed for covert attention shifts, without
resorting to manual RTs. 116 TPs aged 15 to 27 years were measured. TPs that played more
than 4 hours per week were classified as players. Contradictory to our hypothesis CLTs of
peak performance were not shorter in players (171 vs. 169 ms, p=0.9613). But they showed
higher peak (79 vs. 72%, p=0.001) and mean (62 vs. 54%, p=0.0007) performances. Our
results suggest that not the actual attention shift is faster in players, but that they deploy a
more efficient strategy to assess the stimulus relevance. This would fit to other findings which
imply that players are better in processing task relevant information.
33

Poster 10
Effects of a novel antiepileptic drug - Retigabine - on KCNQ2 mutations
associated with epileptic encephalopathies.
Elena Ilina, Katja Detert, Holger Lerche, Snezana Maljevic
Eberhard Karls Universität Tübingen
Epilepsy is a common and multifaceted neurological disorder characterised by seizures, which
result from hypersynchronous, excessive neuronal activity. Despite the wide variability of
antiepileptic drugs, one third of patients still does not respond to a conventional treatments.
Therefore, there is a need for novel options of treatment. Retigabine is a third-generation anticonvulsant
compound that has recently been approved by the USFDA as adjunctive therapy
of partial onset seizures. The drug activates potassium currents, thus reducing the neuronal
excitability. Retigabine specifically targets the M-type potassium current, which is carried
by neuronal voltage-gated Kv7 (KCNQ) potassium channels. Mutations affecting the Kv7.2
channel subunit are known as the most common cause of benign familial neonatal seizures
(BFNS), a rare epileptic syndrome appearing in the first days of life with a spontaneous remission
within weeks to months. Recently seven novel Kv7.2 mutations have been associated
with the more severe outcome - an epileptic encephalopathy with developmental delay. When
expressed in Xenopus oocytes, these seven mutations revealed a severe loss-of-function, and
a dominant-negative effect on WT Kv7.2/7.3 channels has been observed for some of them.
This study aims to reveal the effects of Retigabine on the Kv7.2 epileptic encephalopathy mutations
expressed as homo- or hetero- (with Kv7.3 subunits) multimeres in Xenopus oocytes
and analysed using automated two-voltage clamp technique and application of different concentrations
(0, 1 − 100µM) of Retigabine. We are especially interested whether the severe
dominant-negative effect can be reversed by Retigabine, which would make it a promising
compound for the treatment of this severe epileptic syndrome.
34

Poster 11
Influence of static and dynamic physiological parameters on the
measurement of neural activation with functional near-infrared
spectroscopy (fNIRS)
Florian Häußinger, Sebastian Heinzel, Thomas Dresler, Ann-Christine
Ehlis, Andreas Jochen Fallgatter
Eberhard Karls Universität Tübingen - Universitätsklinikum
We have conducted a simulation study in which we found a strong connection between fNIRS
sensitivity and scalp-cortex distance (SCD). By simulating NIR light scattering and absorption
in human head tissue models it could be shown that a high SCD leads to a decreased
volume of light absorbing gray matter and therefore the sensitivity of fNIRS to measure
hemodynamic changes in the cortex is decreased, while it is increased in the scalp. The
head circumference, an easily assessable parameter, was positively correlated with SCD. We
used the simulated volumes of light absorbing scalp (Vscalp) and gray brain matter (Vgray)
to examine the feasibility of fNIRS to measure low frequency oscillations usually observed
within resting state paradigms. We found the signal-to-noise ratio of fNIRS within a frequency
window of [0.01, 0.02] Hz to be significantly correlated with Vscalp and within [0.02,
0.05] to be significantly correlated with Vgray. These findings suggest that fNIRS is feasible
for resting state paradigms, but also that not the whole range of the low frequency window
is accessible. We also conducted a simultaneous fNIRS-fMRI study in which participants
performed a working memory paradigm. We found the SCD to decrease the amplitude of
hemodynamic responses to stimuli as measured by fNIRS. Beyond that, we observed a different
impact of extracranial hemodynamics (as measured by fMRI) on fNIRS-signals. The
signal that maps concentration changes of oxygenated hemoglobin (oxy-signal), was severely
impacted by skin blood flow, whearas the deoxy-signal was hardly affected. By conducting a
simultaneous fNIRS-fMRI session during an inter-temporal choice paradigm, we found an interesting
correlation between brain activation as measured by fMRI and a personality trait of
the participating subjects. In contrast, this correlation could not be found with fNIRS. The
influence of task-evoked extracranial signals impairing especially the oxy-signal may have
been the limiting factor.
35

Poster 12
Effects of visual attention on neural processing in Rhesus´ V1 by
simultaneous electrophysiology and BOLD-fMRI
Frederico A. C. Azevedo, Leonardo A. C. Azevedo, Nikos Logothetis,
Georgios Keliris
Max Planck Institute for Biological Cybernetics
Attention is a cognitive function thought to enhance our ability to select, process, and perceive
only a behaviorally relevant fraction of the immense sensory input impinging on our receptors
(Knudsen, 2007). Early electrophysiological studies in primates demonstrate that attention
can modulate substantially the firing rate of single cells in extrastriate visual areas but has no
or little impact in the primary visual cortex (Moran & Desimone, 1985). In contrast, attention
has been linked to strong bloodoxygen-level-dependent (BOLD) signal modulations in human
subjects (Gandhi et al., 1999). Our goal is to understand how selective visual spatial attention
modulates the neuronal activity in primary visual cortex (V1) and how these effects are
reflected in the different signals (single unit activity, local field potentials, and BOLD). To this
end, we have trained two rhesus macaques to perform an orientation-change detection task in
high field fMRI scanners (4.7T, 7T) while we can simultaneously acquire high-resolution fMRI
maps and electrophysiological signals. Preliminary results suggest that attention modulates
the BOLD and electrophysiological signals in distinct ways. We are currently trying to address
the layer specificity of the effects by using MRI compatible multicontact probes and implanted
RF coils that provide ultra-high resolution maps of the fMRI activations.
36

Poster 13
Song discrimination ability of juvenile and adult zebra finches
Gagan Narula, Aleks Jovalekic, Joshua Herbst, Richard Hahnloser
University of Zurich
Human infants and adults have been shown to be equally competent in perceiving phonetic
categories of their native language. Surprisingly, studies have shown that infants below the
age of 8 to 9 months can perceive differences in acoustically similar phonetic categories in nonnative
languages, while adults cannot. This discriminative ability falls sharply after the age of
10 months, which is considered to be an effect of continuous exposure to sounds of the native
language, possibly associated with allocation of resources for the representation of the same.
Alternatively, the apparent loss could also result from simply aging within a critical sensory
period, which can be viewed as a reduction in the total neural capacity to represent speech and
not as a specific increase in the representation of the native language. To distinguish between
these possibilities, one would need to compare the phoneme discrimination performance of
normally raised adult subjects with those of adults acoustically isolated at a young age - an
unethical experiment in humans. This motivates the use of an appropriate animal model. We
study the auditory discrimination ability of the songbird species zebra finch (Taeniopygia
guttata), since it is also a vocal learner. In our experiment, we present a novel operant
conditioning protocol designed to train juvenile and adult zebra finches, both male and female,
on a difficult auditory discrimination task using zebra finch song syllables as stimuli. Through
controlled alteration of the duration of the stimuli we can create two artificial categories of
syllables: ¨shortänd ¨ long ¨ , to determine how well zebra finches learn the boundary between
them. Our prediction is that young birds learn faster and have finer discrimination abilities
than adults.
37

Poster 14
Comparing the other race effect and congenital prosopagnosia using a
three-experiment test battery
Janina Esins, Johannes Schultz, Bo Ra Kim, Christian Wallraven,
Isabelle Bülthoff
Max Planck Institute for Biological Cybernetics
Congenital prosopagnosia, an innate impairment in recognizing faces, as well as the otherrace-effect,
the disadvantage in recognizing faces of foreign races, both influence face recognition
abilities. Here we compared both phenomena by testing three groups: German congenital
prosopagnosics (cPs), unimpaired German and unimpaired South Korean participants (n=23
per group), on three tests with Caucasian faces. First we ran the Cambridge Face Memory
Test (Duchaine & Nakayama, 2006 Neuropsychologia 44 576-585). Participants had to
recognize Caucasian target faces in a 3AFC task. German controls performed better than
Koreans (p=0.009) who performed better than prosopagnosics (p=0.0001). Variation of the
individual performances was larger for cPs than for Koreans (p = 0.028). In the second experiment,
participants rated the similarity of Caucasian faces (in-house 3D face-database)
which differed parametrically in features or second order relations (configuration). We found
differences between sensitivities to change type (featural or configural, p=0) and between
groups (p=0.005) and an interaction between both factors (p = 0.019). During the third experiment,
participants had to learn exemplars of artificial objects (greebles), natural objects
(shells), and faces and recognize them among distractors. The results showed an interaction
(p = 0.005) between stimulus type and participant group: cPs where better for non-face
stimuli and worse for face stimuli than the other groups. Our results suggest that congenital
prosopagnosia and the other-race-effect affect face perception in different ways. The broad
range in performance for the cPs directs the focus of our future research towards looking for
different forms of congenital prosopagnosia.
38

Poster 15
Layer and stimulus specific effects of basal forebrain stimulation on neural
responses in the primary visual cortex
Julia Veit, Anwesha Bhattacharyya, Robert Kretz, Gregor Rainer
Universität Fribourg
Acetylcholine is an important neuromodulator for regulating activity and plasticity in the
cortex. Cholinergic projections to the cortex originate in the basal forebrain (BF). We use
microstimulation of this region to investigate cholinergic effects on visual processing in the
primary visual cortex (V1) of tree shrews. We recorded spiking activity and local field potentials
(LFPs) from 109 locations through all cortical layers in 9 anesthetized animals with
pairs or triplets of tetrodes during visual stimulation with binary sparse noise. The spectrum
of spontaneous LFP activity typically showed a decrease in low frequency power (

Poster 16
Neuronal correlates of visual working memory in the carrion crow (Corvus
corona)
Konstantin Hartmann, Lena Veit, Andreas Nieder
Eberhard Karls Universität Tübingen - Institute for Neurobiology
Working memory is the ability to temporarily store and manipulate currently important
information to produce goal-directed behaviour. Working memory is thus a cardinal feature
of all sorts of intelligent behaviours and has been studied intensively in mammals, especially
in primates. In primates, neural correlates of working memory are located in the prefrontal
neocortex (PFC) of the frontal lobe. Contrary to mammals, birds show a very differently
evolved brain and do not possess a neocortex. Still, there is no doubt that bird show superior
working memory abilities. Especially corvids are known for their intelligent behaviours that
include high-level cognition. The convergent brain structure representing working memory
in corvids remains elusive. Research on pigeons, however, suggests that a distinct region in
the avian telencephalic pallium, the nidopallium caudolaterale (NCL), serves as the avian
analog of the primate PFC. To investigate neural correlates of working memory in the avian
brain, we trained carrion crows to perfrom a computer-controlled visual delayed matchingto-sample
task, a classic task involving a working memory period. In this task, a sample
image is displayed on a touch screen for 500 ms that the crow needs to encode and memorize
during the following delay period (1000 ms) showing no stimulus at all. Next, four test
images are presented on the touch screen, and the bird is forced to peck the image identical
to the sample image. This behavioural protocol allows us to exclude confounding factors
like reward-expectation and motor-preparation. After the crows proficiently mastered the
task, we extracellularly recorded single unit activity from the behaving corvids´ NCL. As a
neuronal correlate of working memory, we found neurons with sustained activity during the
delay period. These neurons selectively varied their firing rate during the delay period as a
function of the preferred visual stimulus to remember, as statistically analyzed with a nonparametric
ANOVA (P

Poster 17
Molecular Characterization of a Serine Pro-tease Htra1Implicated in AMD
Lili Feng, Elöd Körtvely, Andreas Vogt , Karsten Boldt , Marius Ueffing
Eberhard Karls Universität Tübingen
Molecular Characterization of a Serine Protease Htra1 Implicated in AMD The degeneration
of the retina has already begun by the time the patient is diagnosed with age-related macular
degeneration (AMD) in the clinic, implying on going proteolysis process. Genome-wide
association studies established two major risk haplotypes on chromosome 1 and chromosome
10. This latter locus harbours three genes including Htra1. Being a member of the trypsin
family of serine protease, Htra1 is an attractive candidate for playing a causative role in
the pathogenesis. This secreted protease is known to regulate the availability of insulin-like
growth factors (IGFs) by cleaving IGF-binding proteins, and repressing signalling mediated
by TGF-beta family members. Nevertheless, our results obtained from yeast two-hybrid and
co-immunoprecipitation experiments indicate that Htra1 plays an instrumental role also in
further process. Interestingly, Htra1 was found to interact with complement factor D (CFD).
Because the risk haplotype of complement factor H (CFH) is very strongly associated with
the disease, this interaction may further strengthen the involvement of the complement alternative
pathway in in the development of the symptoms. On the other hand, the physiological
significance of the Htra1-CFD interaction has still remained unknown.
41

Poster 18
Right prefrontal cortex alpha activity related to inhibition of responses
Maike Hege, Krunoslav Stingl
Eberhard Karls Universität Tübingen
Cognitive inhibition is a crucial executive function required to control responses to external
stimuli. A task frequently used to study the inhibition of responses to certain stimuli is the
go-nogo task. Neuroimaging studies have shown that the prefrontal cortex is activated more
strongly on nogo trials and necessary for correct performance on this task. However, time
courses and frequency spectrum of activity in prefrontal cortex have so far not been explored
in human subjects. We recorded magnetic brain activity from 20 lean, female subjects during
a go-nogo task requiring inhibition to food or toys pictures. We observed increased activation
in right dorsolateral prefrontal cortex (rDLPFC), right temporal gyrus, and bilateral medial
cortex on nogo and increased activation in postcentral gyrus on go trials. Extracted time
courses of rDLPFC activation showed increased activation on nogo trials in comparison to
go trials, reaching the maximum difference at around 250 ms. In the frequency domain, we
observed increased activation in the alpha frequency band (8-12 Hz) in nogo trials localized
to rDLPFC. Furthermore, errors on nogo trials were associated with increased alpha activity
in frontal sensors in the prestimulus interval. In conclusion, our data gives further insight into
rDLPFC function during cognitive inhibition and points out a central role for alpha activity
in correct performance during go-nogo task.
42

Poster 19
Looking for the path not taken: an investigation of the influence of
alternative motor plans during perceptual and value-based decisions
Marina Fridman, Axel Lindner
Werner Reichardt Centre for Integrative Neuroscience
The affordance competition hypothesis states that some types of decision making happen
not only through a competition between goals but also between the motor plans of how to
achieve these goals. In addition to neurophysiological studies that have shown alternative
action plans in parietal and premotor cortex, behavioral studies suggest that reach trajectories
can likewise reflect competing motor plans in difficult perceptual decisions. We sought
to replicate these results in a perceptual decision task as well as in a novel, more naturalistic,
value-based decision task. In the latter, participants saw two landscape images in each
trial and had to point to their preferred image. In the perceptual decision task, participants
judged the direction of motion of a moving dot stimulus by pointing to an arrow symbol. In
both tasks we manipulated choice difficulty; in the value-based decision task, difficulty was
determined by whether a clear favorite was present (easy) or not (difficult) in the image pair.
In the perceptual decision task, difficulty was controlled by varying the ratio of dots moving
in each direction. All reach decisions were performed in a virtual environment where, unlike
previous studies, participants had no visual feedback of their hand. After each reach, participants
were asked to report their perceived pointing direction by setting a cursor into that
direction. According to the affordance competition hypothesis, we expected to see evidence
of alternative motor plans in the reach trajectory during difficult decisions, namely in the
shape of trajectories curved towards the unchosen goal, or in a shift of reach endpoints in the
same direction. We also predicted that the perceived pointing direction, which is thought to
depend on corollary discharge of an outgoing motor plan, would change to reflect the motor
plan to the unchosen goal in more difficult choices. Although the manipulation of both experiments
worked, as evidenced by our ability to predict choices in the easy condition (p

Poster 20
Rhesus monkey can switch volitionally between distinct call types
Natalja Gavrilov, Steffen R. Hage, Andreas Nieder
Eberhard Karls Universität Tübingen - Institute for Neurobiology
Speech is one of the key distinguishing features that defines us as human and allows us sophisticated
audio-vocal communication. A necessary criterion for language production is volition.
Speech sounds that we learn throughout our lives can be uttered or withheld on command.
Vocal utterances of non-human primates, our closest phylogenetic relatives, however, are genetically
determined and generally assumed to be highly affective and tightly bond to specific
motivational states. Whether nonhuman primates can decouple their vocalizations from the
accompanied motivational state and instrumentalize them in a goal-directed way remains a
matter of debate for decades. So far, all attempts trying to show that non-human primates
are able to volitionally control their vocalizations failed, were of anecdotal evidence, suffered
from severe methodological shortcomings or confirmed that nonhuman primates produce adequate
motivationally based responses to hedonistic stimuli rather than demonstrating the
capability to volitionally vocalize on command. We trained a rhesus monkey to perform a
computer-controlled "go/nogo" detection task by using its vocalization as a response. The
monkey was required to utter different types of vocalizations in response to distinct arbitrary
visual stimuli to receive a reward. The obtained data were analyzed by applying signal detection
theory (SDT). As a measure of sentitivity, the d-prime-values were calculated. Our
results show that the monkey was able to instrumentalize its vocal utterances in response
of arbitrary visual cues. Importantly, the monkey was able to respond with different vocalizations
in response of different arbitrary visual cues to receive a reward. Throughout the
experimental sessions, the mean d-prime values for grunts and for coos were 1.97 and 1.8,
respectively. This indicates that it was able to decouple its vocal output from a motivational
state. Our results show that monkeys are able to volitionally initiate their vocal output. This
capacity might constitute an obligate communication precursor for the evolution of speech in
the primate lineage. The present study paves the way to study evolutionary aspects of human
speech control in a nonhuman primate.
44

Poster 21
Intuitive Decisional Processes in a Perceptual Discovery Task: An MEG
Study.
Ninja Katja Horr, Christoph Braun, Kirsten Volz
Werner Reichardt Centre for Integrative Neuroscience
Everyday life decisions are often made immediately without consciously thinking through all
possible alternatives and steps of reasoning. Such kinds of decisions can be considered as
intuitive. Taking a look at different attempts to define intuitional mechanisms three common
definition criteria can be worked out: (1) Intuitional mechanisms are not necessarily conscious,
i.e. though reflecting upon them might make them reportable, during the decision itself they
are not, (2) they are strong enough to lead to quick behavioral outcomes and (3) they depend
on prior experience in the sense of not consciously retrieved memory contents that lead
to a decision or solution. Taking those definition criteria into account the present study
uses a modified version of the Waterloo Gestalt Closure Task to operationalize intuition
as the "preliminary perception of coherence" (Bowers et al., 1990). The temporal dynamics
of neuronal mechanisms underlying such coherence judgements are examined with MEG.
Methods and Results from the pilot study are presented and an outlook is given.
45

Poster 22
Task-specific color selectivity in prefrontal and parietal areas
Pooja Viswanathan, Andreas Nieder
Eberhard Karls Universität Tübingen - Institute for Neurobiology
Sensory stimuli often need to be categorized to drive behavior and decisions. The neural
correlates of color categorization, like other categories, have been studied in recent years. It
has been suggested that neurons in the inferior temporal (IT) cortex, that forms the ventral
stream with areas V2 and V4, represent color categories by modulating their firing rates.
These responses also change to represent the behavioral threshold, thus, suggesting a key role
of the IT cortex in color cognition. However, color categorization has not been investigated
in prefrontal or parietal cortices that are often studied in relation to cognitively challenging
categorizations. We recorded neurons from the dorsolateral prefrontal cortex along the bank of
principal sulcus (PFC) and the ventral intraparietal (VIP) area while the monkeys performed
a delayed match to sample color task. The monkeys matched the color of a sample stimulus to
that of test stimuli presented sequentially after a delay period. A color match was reported
by releasing a bar held throughout the trial and rewarded subsequently. Five colors were
selected after testing for above 95% behavioral discrimination performance and presented
foveally as colored dots against a gray background circle. The exact location of the colored
circles within the gray background circle and their total area was varied from trial to trial.
Neurons from both areas show significant modulation (ANOVA, p

Poster 23
Synaptic interations in the outer retina of the mouse
Robin Kemmler, Thomas Euler, Timm Schubert
Eberhard Karls Universität Tübingen
At the very first synapse of the visual system, the photoreceptor synapse, horizontal cells
(HCs) provide inhibitory feedback to cone photoreceptors (cones). This feedback is thought
to dynamically adapt the working range of cones to the ambient light and to contribute an
outer retinal component to the generation of antagonistic receptive fields. Based on data
from different vertebrate species, three distinct types of mechanisms have been proposed to
be involved in the feedback from HCs to cones: hemichannel-based ephaptic, pH-mediated
and GABAergic feedback (reviewed in Thoreson and Mangel, Prog Retin Eye Res, 2012).
Here we aim at investigating which of these feedback mechanisms are present in the mouse
retina and, in case there are multiple candidates, whether these mechanisms operate in parallel
or under different conditions. As all feedback mechanisms described so far modulate
cone output, our approach was to assess the effect of HC feedback on light-evoked Ca2+
responses measured in cone terminals of a transgenic mouse using two-photon microscopy. In
this mouse line (HR2.1:TN-XL; Wei et al., J Neurosci, 2012), cones selectively express the
Ca2+ biosensor TN-XL under the control of the human red opsin promoter. Feedback mechanisms
were pharmacologically dissected using light stimuli of different polarity (stimuli darker
or brighter than background light intensity) and contrast. Application of Carbenoxolone, a
gap junction blocker, increased both resting Ca2+ level and amplitude of light-evoked Ca2+
responses, suggesting the presence of hemichannel-mediated ephaptic feedback in mouse.
Clamping extracellular pH with HEPES reversibly reduced the initial peak of dark-evoked
Ca2+ responses, which argues against an involvement of protons in inhibitory feedback from
HCs to cones but rather suggests that protons play a role in an "excitatory" feedback mechanism
shaping cone responses to dark flash-stimuli. Finally, preliminary experiments in which
we mimicked a potential GABAergic feedback mechanism by applying GABA, decreased the
amplitude of light-evoked Ca2+ responses, consistent with the GABAergic HC feedback hypothesis.
Our data support the presence of ephaptic and GABAergic feedback functioning as
inhibitory feedback mechanisms in the mouse retina. A pH-mediated mechanism, however,
may provide ¨ facilitory ¨ feedback from HCs to cones. Thus, all three feedback mechanisms may
be employed in the outer retina to shape the synaptic output from cones.
47

Poster 24
The role of adenosine in the neurovascular coupling of the BOLD signal in
early visual cortex of non-human primates
Sneha Viswanath, Daniel Zaldivar, Veronika Von Pfoestl, Alexander
Rauch, Nikos K. Logothetis
Werner Reichardt Centre for Integrative Neuroscience
In this study, CPX, an antagonist of adenosine was used to determine the role of adenosine in
uncoupling the vascular and neuronal response observed by the BOLD signal after a strong
visual stimulation in primary visual cortex (V1). We systemically and locally applied CPX
and pharmacologically manipulated the sensory response in the early visual cortex of anaesthetized
macaques. Pharmacological magnetic resonance imaging (phMRI) in combination
with electrophysiology was used to determine the impact of CPX on V1. Results were obtained
from recordings of the BOLD and electrophysiological activity during the injections.
Systemic application of CPX resulted in a disruption of the visual modulation in the BOLD
signal. Local applications of CPX resulted in a decrease in the power of low LFP and an
increase in the power of MUA. In addition it resulted in a decrease in the CV and FF. No
significant changes were observed in the BOLD signal after systemic application of phosphate
buffered saline, which was used as a control. The results show that we indeed observe dissociation
between the vascular and the neuronal activity during adenosinergic modulation.
Apparently adenosine reduces functional hyperaemia, which is reflected by the reduction in
BOLD signal, while underlying neuronal activity is increased, indicated by an increase in
MUA. Further studies have to be conducted using simultaneous sampling of neurochemicals
and phMRI to fully elucidate the functional role of adenosine for the vascular and neuronal
interplay in V1.
48

Poster 25
Neuronal correlates of online control in reaching and grasping
Sonja Cornelsen, Marc Himmelbach, Axel Thielscher
Eberhard Karls Universität Tübingen - Universitätsklinikum
Reach-to-grasp movements recruit regions of the parieto-frontal network that can be subdivided
into two neuronal circuits. The dorsomedial circuit, which is traditionally associated
with reaching, comprises the superior parietal occipital cortex (SPOC), the medial intraparietal
sulcus (mIPS), and the dorsal part of the premotor cortex (PMd). The dorsolateral
circuit is associated with grasping and includes the anterior intraparietal sulcus (aIPS), which
is highly interconnected with the ventral part of the premotor cortex (PMv) (Tanne-Gariepy
et al., 2002; Tomassini et al., 2007). However, recent findings argue against a strict functional
separation of both circuits and indicate a modulation of the functional connectivity by the
required amount of online control (Grol et al., 2007). To investigate the functional overlap
of the circuits during online control, we employed a perturbation paradigm that allowed us
to separate the BOLD signal reflecting online control from that of the planning phase. During
fMRI, participants had direct sight of the two target objects that were either unchanged
throughout the movement (unperturbed) or could change their location (reaching perturbed),
size (grasping perturbed), or both after movement onset. We acquired whole-brain functional
images. Based on anatomical landmarks and specific contrasts regions-of-interests (ROIs)
were determined. Importantly, the ROI analyses revealed that neither SPOC, aIPS, mIPS,
nor PMd differed significantly in the comparison of perturbed reaching and perturbed grasping
although the selection of the ROIs was biased in favour of either condition. However,
a comparison of grip size corrections revealed significant differences in the right mIPS, and
the right PMd. A similar pattern emerged for the connectivity analysis that revealed no
modulations of the connectivity for the contrast reaching perturbed and grasping perturbed.
However, during grip size corrections, coupling was increased between SPOC and aIPS, mIPS
and aIPS, and also between PMd and aIPS, indicating a functional overlap of the dorsolateral
and dorsomedial circuit. This argues against a strict functional separation of both circuits
but rather suggests two widely congruent systems that show a slight relative bias towards
either reaching or grasping.
49

Poster 26
Optimization of Subretinal Electrical Stimulation to Generate Naturalistic
Spiking Responses
Sudarshan Sekhar, Daniel Rathbun, Eberhart Zrenner
Eberhard Karls Universität Tübingen - Institute of Ophthalmic Research
Introduction: Our aim is to restore vision to the blind via a subretinal prosthesis. To date,
the Tübingen subretinal implant project has realized the best clinical results of any visual
prosthetic device. However, substantial improvements are still possible through the implementation
of more sophisticated neural coding principles. Our strategy is to characterize the
differences in the spiking responses of mouse retinal ganglion cells to visual and electrical
stimulation and then optimize the association between visual inputs and the electrical output
of the implant to reduce these differences. Methods: Our visual stimulus is a 60 second
¨natural scene ¨movie, while our electrical stimuli consists of a series of monophasic, square
voltage pulses with varying voltages and durations. To quantitatively compare visual and
electrical responses, we calculate information content [Magri et al, BMC Neurosci., 2009],
spike train similarity [Victor et al, Curr. Op. Neurobiol., 2005] and coding precision and reliability
[Berry et al., PNAS, 1997]. Results: We will calculate the information contained in
the spike trains about either visual or electrical stimuli to determine whether responses to
the currently used set of electrical stimuli are capable of encoding as much information as is
found in visual responses. However, since there are many potential codes that could produce
the target amount of information without being interpretable by the brain, we will quantify
the reliability and precision of spiking events to ensure that these visual response statistics
are also well matched by electrical stimulation. Finally, we will quantify how similar repeated
responses to the same stimulus are as well as how similar electrical responses are to visual
responses with the end goal of developing a method of generating electrical stimuli from
visual input whose responses fall within the distribution of normal responses for any given
visual stimulus. Conclusions: The quantities discussed above will serve as a first indication
of how good current prosthetic strategies are at eliciting naturalistic spiking responses. Our
final aim is to improve the algorithm through which light is converted to voltage signals at
each pixel of the Tübingen retinal implant such that the elicited ganglion cell spikes in blind
patients more closely match those of healthy subjects for any given visual stimulus.
50

Poster 27
Roles of different fastigial nuclei neurons in saccade direction tuning and
saccadic adaptation
Zong-Peng Sun, Marc Junker, Fahad Sultan, Peter Dicke, Aleksandra
Smilgin, Peter Thier
Hertie-Institute for Clinical Brain Research
Improving motor behavior based on learning is a key function of the cerebellum. What is the
code the cerebellum uses to adjust the behavior? Many efforts have been made to understand
the function of the cerebellar cortex in motor tasks. Our understanding of the cerebellar
function has historically been based on the precise that the cerebellar cortex is the site of
information processing, or at least memory storage and retrieval. However, as to the deep
cerebellar nuclei (DCN), which are in a key position within cerebellar circuitry and play an
important role in exclusively integrating inputs from the brain stem, the inferior olive, and
the spinal cord with the output of the cerebellar cortex, little is known of the different functions
that the DCN neurons have to provide in a goal-directed task, such as a saccadic eye
movement or in the adaptation of such a motor task. Furthermore, recent studies in rodents
showing differences in morphological and electrophysiological properties between various populations
of neurons in DCN have remained elusive as to their function. Our investigation will
improve our understanding of different functions of DCN neurons. As an only output of the
cerebellum, the roles of Purkinje cells in saccadic eye movement and motor learning have
been well studied, however, as an important station on the way of purkinje cells output, few
studies have conducted on the role of fastigial nuclei in motor learning. The Purkinje cells
of the oculomotor vermis have been well studied and are known to converge on neurons of a
subpart of the DCN, the caudal fastigial nucleus. Different populations of neurons have been
described within this nucleus based on their neurotransmitter content (i.e., Glutamatergic,
GABAergic and Glycinergic) and based on their projection target site. However, the various
populations of neurons of the DCN and the relationship between them and motor learning
remain poorly understood. Our study aims to reveal the roles of different fastigial nuclei neurons
in saccade direction tuning and saccadic adaptation according to their firing properties
(both spontaneous discharge patterns and saccade-related discharge patterns) in vivo.
51

Participants
52
Name Email Address
Organizers
André Maia Chagas andre.chagas@klinikum.uni-tuebingen.de
Katharina Dobs katharina.dobs@tuebingen.mpg.de
Lena Veit lena.veit@uni-tuebingen.de
Marc Junker marc.junker@uni-tuebingen.de
Pooja Viswanathan pooja.viswanathan@student.uni-tuebingen
Participants
Abhilash Dwarakanath abhilash.dwarakanath@tuebingen.mpg.de
Agnes Kroczek Agnes.Kroczek@med.uni-tuebingen.de
Aleksandra Smilgin a_smilgin@yahoo.com
Alessandro Nesti alessandro.nesti@tuebingen.mpg.de
Ali Zaidi ali.zaidi@tuebingen.mpg.de
Almut Hoffmann almut.hoffmann@ntz.de
Anette Giani anette.giani@tuebingen.mpg.de
Anne Suffel Anne.Suffel@gmx.de
Balint Nagy nagyblint@yahoo.com
Barbara Wirxel barbara.wirxel@uni-tuebingen.de
Bartosz Kula bartoszkula@op.pl
Ceren Battal battal.ceren@gmail.com
Chang Yan sunnykirk119@gmail.com
Chen Chih-Yang chen.chih-yang@cin.uni-tuebingen.de
Daiju Abe leongougeon1980@gmail.com
Daniel Arnstein danarnstein@gmail.com
David Jule Mack david-jule.mack@student.uni-tuebingen.de
Dong-Seon Chang dongseonc@gmail.com

Name Email Address
Ekaterina Volkova ekaterina.volkova@tuebingen.mpg.de
Elena Ilina ielenas4c@yandex.ru
Eliana Garcia elilife@gmail.com
Emily Fan eypfan@gmail.com
Erick Ortiz erick.ortiz@med.uni-tuebingen.de
Evgeny Sheygal evgeny.sheygal@student.uni-tuebingen.de
Fabricio Lima Brasil fabriciobrasil@gmail.com
Felix Moll felix87moll@googlemail.com
Florian Franzen Florian.Franzen@student.uni-tuebingen.de
Florian Häußinger florian.haeussinger@med.uni-tuebingen.de
Florian Soyka florian.soyka@tuebingen.mpg.de
Frederico Azevedo frederico.azevedo@tuebingen.mpg.de
Gagan Narula gagan_narula1986@hotmail.com
Galyna Pidpruzhnykova galyna.pidpruzhnykova@gmail.com
Gerrit Schwesig gerrit.schwesig@gmx.de
Gina Eom gina.eom@gmail.com
Hamed Bahmani hamed.bahmani@tuebingen.mpg.de
Jan Winchenbach jan.winchenbach@dzne.de
Janina Esins janina.esins@tuebingen.mpg.de
Josue Luiz Dalboni da Rocha josuedalboni@yahoo.com.br
Juan Sehuanes jfsehuanes@gmail.com
Julia Veit julia.veit@unifr.ch
Katarina Matic katarina.matic@uni-tuebingen.de
Katharina Stegen Katharinastegen@yahoo.de
Katrin Franke katrin_fr88@gmx.de
Konstantin Hartmann konstantin.hartmann@student.uni-tuebingen.de
Leonardo Azevedo leonardocazevedo@gmail.com
Lili Feng lili.feng@uni-tuebingen.de
Lothar Freißmann LuH-Freissmann@web.de
Madison Carr madisonrcarr@gmail.com
Maike Hege maike.hege@med.uni-tuebingen.de
Manuel Schweighauser manuel.schweighauser@uni-tuebingen.de
53

Name Email Address
54
Marco Curado marco.curado@gmail.com
Marina Fridman aniram06@gmail.com
Mehtap Bacioglu mbacioglu@gmail.com
Mohammad Khazali tetaretajoin@hotmail.com
Mojtaba Soltanlou soltanlou@gmail.com
Natalja Gavrilov natalja.gavrilov@student.uni-tuebingen.de
Nele Hellbernd nele.hellbernd@web.de
Nicholas Del Grosso delgrosso.nick@gmail.com
Ninja Katja Horr Ninja78278@aol.com
Rahim Malekshahi rahim.malekshahi@student.uni-tuebingen.de
Robin Kemmler robin.kemmler@gmx.net
Rümeysa Gündüz anterbea@hotmail.com
Ruxandra Barzan ruxandrabarzan@gmail.com
Sneha Viswanath snehav86@gmail.com
Sonja Cornelsen sonja.cornelsen@uni-tuebingen.de
Stephan Streuber stephan.streuber@tuebingen.mpg.de
Stine-Carlotta Dehnke stine-carlotta.dehnke@student.uni-tuebingen.de
Sudarshan Sekhar sudsa89@gmail.com
Svenja Espenhahn S.Espenhahn@gmx.de
Thea Zander thea.zander@cin.uni-tuebingen.de
Theano Mintsi theano.mintsi@epfl.ch
Thomas Baden thomas.baden@uni-tuebingen.de
Urszula Mihulowicz urszula.mihulowicz@klinikum.uni-tuebingen.de
Vineet Arora vineetarora8@gmail.com
Zong-Peng Sun sunzongpeng1987@163.com

Notes