Abstracts 2005 - The Psychonomic Society

Papers 61–67 Friday Morning
11:00–11:15 (61)
Visual Acuity in Virtual and Real Depth. ANKE HUCKAUF, Bauhaus
University, Weimar—Acuity, one of the basic visual functions, is known
to be higher on the horizontal than on the vertical meridian (Rovamu
& Virsu, 1979). We investigated visual acuity in depth and compared
it with acuity in horizontal and vertical directions. Letters were presented
tachistoscopically at 3º, 6º, and 9º of eccentricity in the left,
upper, or backward visual field. Presentation was elicited by an accurate
fixation. For depth acuity, a fixation arrow was placed at various
distances between the monitor and the observer. Letter recognition
was worse in depth than in both other directions, repeatedly and
for all observers. However, the presentation of a virtual fixation arrow
on an auto-stereoscopic monitor resulted in better performance than
did the presentation of a real fixation arrow. This result demonstrates
that accommodation can be controlled independently from vergence.
However, an independent adjustment of accommodation and vergence
does not seem to be under voluntary control.
11:20–11:35 (62)
The Roles of Altitude and Fear in the Perception of Height. JEANINE
K. STEFANUCCI & DENNIS R. PROFFITT, University of Virginia
(read by Dennis R. Proffitt)—People often exhibit normative biases in
their perception of the environment. For instance, slant is typically
overestimated, and distance is usually underestimated. Surprisingly,
the perception of height has rarely been studied. In a series of experiments,
participants performed visual matching assessments of apparent
distance and size while looking down from a balcony or looking up
from the ground. When they were looking down, distances were overestimated
by 60%, and the size of targets on the ground was overestimated
by 22%. When they were looking up, the same distances were
overestimated by 23%, and size estimates for targets viewed from
below were accurate. In addition, a nonoptical variable—fear—was
positively correlated with participants’ overestimation of height. We
suggest that the overestimation of height that occurs when one looks
down from a high place is due to both the altitude and a fear of falling.
11:40–11:55 (63)
Color/Luminance Dissociations Across “How,” “What,” and “Where”
Processing of Normal Participants: A Second Look. ALISSA WINK-
LER, CHARLES E. WRIGHT, & CHARLES CHUBB, University of
California, Irvine (read by Charles E. Wright)—In 2003, we reported
that equiluminant color and isochromatic luminance defined stimuli
that were found to be equisalient in a shape identification (“What”)
task did not support equivalent performance in a pointing (“How”)
task. Such task-related contrasts (TRCs) are consistent with the suggestion
that there exist functionally separate pathways in the architecture
of visual processing. Here, we report new experiments that
(1) replicate our earlier finding of a TRC for color- and luminancedefined
stimuli across the What and How tasks, eliminating methodological
concerns, (2) reveal new TRCs between these tasks and an
allocentric “Where” task, and (3) find no TRCs between speeded and
information-limited variants of the What and Where tasks.
Animal Learning
Conference Rooms B&C, Friday Morning, 10:20–12:00
Chaired by Ralph R. Miller, SUNY, Binghamton
10:20–10:35 (64)
Laws of Learning Appear to Differ for Elemental Cues and Compound
Cues. RALPH R. MILLER & GONZALO P. URCELAY, SUNY,
Binghamton, & KOUJI URUSHIHARA, Osaka Kyoiku University—
The basic laws of learning for cues trained elementally have been intensively
studied for a century. Recently, additional laws of learning
have been identified for elements trained as part of compound cues,
but researchers have assumed, without proper tests, that the laws governing
elements alone also apply to elements within compounds. Experiments
with rats will be reviewed demonstrating that interactions
10
between elements of compound cues not only produce the well documented
phenomena of cue competition, but also, under certain circumstances,
negate laws that apply to elemental cues alone. Examples
of deleterious effects that do not always appear when target training
occurs as part of a compound cue include trial massing, CS lengthening,
latent inhibition, partial reinforcement, degraded contingency,
and US preexposure effects. The addition of any one of these deleterious
treatments to a preparation that otherwise yielded overshadowing
reduced both the effect of the deleterious treatment and the overshadowing
effect. The generality of these findings are discussed.
10:40–10:55 (65)
Out of Sight, Not Out of Mind: Rats Know When an Absent Event
Should Have Been Observed and When It Shouldn’t Have. AARON P.
BLAISDELL, UCLA, MICHAEL WALDMANN, University of Göttingen,
& W. DAVID STAHLMAN, UCLA—We previously failed to
demonstrate second-order conditioning involving tone→light and
light→food pairings in rats. When tested on the second-order tone
alone, rats might have expected the light to occur upon termination of
the tone. However, the light did not occur on tone-alone test trials,
which may have reduced the expectation of food. We tested the hypothesis
that occluding the light bulb at test, thereby removing the expectation
that the light should be observable, would salvage the expectation
of food at test. This hypothesis was confirmed by the
demonstration of greater nosepoking to the tone, relative to an unpaired
control stimulus, when the light bulb was occluded at test, but
no difference in nosepoking when the light bulb was visible. Furthermore,
the temporal location of the increased rate of nosepoking suggests
that rats integrated a tone–food temporal map based on the
tone–light and light–food temporal maps.
11:00–11:15 (66)
Blocking and Pseudoblocking: New Control Experiments With
Honeybees. P. A. COUVILLON, RACHEL E. BLASER, & M. E.
BITTERMAN, University of Hawaii, Manoa—Prompted by doubts
about the adequacy of the various control procedures long used in research
on blocking, we repeated some earlier experiments with honeybees
that had given the appearance of forward, concurrent, and
backward blocking. The new experiments differed from the earlier
ones only in that the target stimulus was omitted during the training
and was encountered for the first time in the test. In the new experiments,
just as in the earlier ones, the blocking groups responded less
to the target stimulus than did the control groups. The results show
that the effects of the different treatments of nontarget stimuli commonly
compared in blocking experiments may generalize to the target
stimulus and, thus, affect responding to that stimulus independently
of experience with it. Implications for research on blocking in
honeybees and other animals are considered.
11:20–11:35 (67)
Delta–9-Tetrahydrocannabinol and Cannabinol, but not Ondansetron,
Interfere With Conditioned Retching in the Suncus murinus:
An Animal Model of Anticipatory Nausea and Vomiting. LINDA A.
PARKER & MAGDALENA KWIATKOWSKA, Wilfrid Laurier University,
& RAPHAEL MECHOULAM, Hebrew University of Jerusalem—Chemotherapy
patients report not only acute nausea and vomiting
during the treatment itself, but also anticipatory nausea and
vomiting upon reexposure to the cues associated with the treatment.
We present a model of anticipatory nausea based on the emetic reactions
of the Suncus murinus (musk shrew). Following three pairings
of a novel distinctive contextual cue with the emetic effects of an injection
of lithium chloride, the context acquired the potential to elicit
conditioned retching in the absence of the toxin. The expression of
this conditioned retching reaction was completely suppressed by pretreatment
with each of the principal cannabinoids found in marijuana,
Δ9-tetrahydrocannabinol or cannabidiol, at a dose that did not suppress
general activity. On the other hand, pretreatment with a dose of
ondansetron (a 5-HT3 antagonist), which interferes with acute vomit-