Abstracts 2005 - The Psychonomic Society

Papers 242–248 Saturday Afternoon
ROEDIGER III, & JEFFREY D. KARPICKE, Washington University
(read by Henry L. Roediger III)—Free recall is often assumed to be a
direct index of recollection. However, some research suggests that automatic
activation contributes to free recall. In three experiments, we
examined the contribution of controlled and automatic processes to
recall using the process dissociation procedure. Subjects studied categorized
word lists under full- or divided-attention conditions. Later,
they were forced to try to recall all of the words they studied, guessing
if necessary (i.e., an inclusion condition). They also were required
to produce an equal number of new category exemplars (i.e., exclusion).
Results indicate that divided-attention reduced the recollection
estimate (R), but the automaticity estimate (A) was equivalent for both
full- and divided-attention conditions. Follow-up experiments estimating
R and A using forced recall with subjective memory reports
(remember/know/guess) and traditional free recall instructions led to
identical results. These data indicate that, contrary to conventional
wisdom, automatic processes makes a substantial contribution to free
recall.
4:10–4:25 (242)
On the Status of Unconscious Memory: Merikle and Reingold (1991)
Revisited. DAVID R. SHANKS & CHRISTOPHER J. BERRY, University
College London, & RICHARD N. A. HENSON, MRC Cognition
& Brain Sciences Unit—Merikle and Reingold (1991) reported priming
for words in the absence of recognition memory in matched indirect
(implicit) and direct (explicit) memory tests. Their striking result
provides powerful and widely cited support for unconscious memory
processes in normal subjects. Using the same paradigm, we report a
series of experiments failing to replicate this key result. After a study
phase, new and previously unattended words were presented against
a background mask. Participants decided whether each word was old
or new (direct task) or whether the contrast between the word and the
background was high or low (indirect task). Unlike Merikle and Reingold,
we consistently found that the magnitude of recognition memory
was greater than or equal to that of priming. These results question
the existence of implicit memory and are, instead, compatible
with the view that performance on implicit and explicit memory tasks
is mediated by a single conscious process.
4:30–4:45 (243)
Using Remember–Know Estimates Versus Categories to Explore
the Wane of Childhood Amnesia. KRISTI S. MULTHAUP, DIANA
AIKEN, ALLISON KAVANAGH, & CATHERINE JAHNES, Davidson
College—To determine the wane of childhood amnesia, recent studies
have used a threshold procedure in which participants classify
childhood memories as remember or know memories (e.g., Bruce,
Dolan, & Phillips-Grant, 2000; Multhaup, Johnson, & Tetirick, 2005).
These studies have yielded a consistent finding of roughly 4.7 years
as the transition point from childhood amnesia to the development of
autobiographical memories. However, autobiographical memories are so
complex, it is likely that a given childhood memory has aspects that are
remembered and other aspects that are known. The present research
modified prior procedures by allowing participants to estimate the percentages
of given childhood memories that were remembered or known,
rather than forcing participants to place their memories entirely into
either category. The transition point with the modified estimation procedure
is roughly 4.7 years of age, replicating the prior findings.
4:50–5:05 (244)
Using Sampling and Recovery to Estimate Context and Item Effects
in Memory. DAVID E. HUBER, YOONHEE JANG, & JAMES P.
VAN OVERSCHELDE, University of Maryland, College Park—Many
global memory models assume that memory retrieval consists of two
components, with sampling depending on the effectiveness of contextual
cuing and the relative strength of encoding and recovery depending
on the adequacy of lexical–semantic knowledge for target
items. Using data from two different sets of experiments, we applied
a simplified version of sampling and recovery to describe data pat-
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terns in terms of the respective contributions of context and item. In
two recall experiments, we measured the effects of preexposure training
on recall of high- and low-frequency words in pure and mixed
lists. In other experiments, we tested recall and recognition for the
“list before the last,” examining interference as a function of intervening
list length and target list length. Similar to signal detection theory,
this descriptive memory modeling is applied to individual subject
data, with the resultant parameters analyzed using standard
inferential statistics.
5:10–5:25 (245)
On Jost’s Law, Individual Differences, and Asymptotes. ANDREW J.
HEATHCOTE, University of Newcastle, & MICHAEL S. HUMPHREYS,
University of Queensland—On the basis of an analysis of participantaverage
retention functions, Wixted (2004) rejected exponential forgetting
and supported Jost’s law. His conclusions depend on two assumptions,
that eventually forgetting is complete (asymptotically,
retention is zero) and that participant averaging does not cause bias.
We show that participant averaging did bias his analyses, and that
when this bias is avoided by analyzing individual participant retention
functions, results support an asymptote greater than zero and exponential
forgetting for most participants. We propose a model of forgetting
based on retrieval failure that is consistent with exponential
forgetting, nonzero asymptotes, and individual differences.
Attention During Tracking and Motion
Grand Ballroom West, Saturday Afternoon, 4:10–5:30
Chaired by Todd S. Horowitz
Brigham & Women’s Hospital and Harvard Medical School
4:10–4:25 (246)
How Do Distractors Affect Performance on the Multiple-Object
Tracking Task? TODD S. HOROWITZ, Brigham & Women’s Hospital
and Harvard Medical School, & SKYLER S. PLACE, Brigham & Women’s
Hospital—Recent evidence from multiple-object tracking (MOT)
experiments suggests that distractors must be actively suppressed.
Does distractor suppression require the same attentional resource as
target tracking? To answer this question, we developed a new MOT
task that allows us to vary target and distractor load independently.
Observers tracked one, four, or eight target disks moving against a
grid of stationary disks. After 2–4 sec, moving disks stopped coincident
with the grid, then all disks changed color to mask targets. One
stationary disk was probed, requiring a yes or no response. We tested
the effect of the mere presence of distractors by comparing performance
with zero distractors and one distractor; there was no effect. Next, observers
tracked four targets with zero, one, two, three, or four distractors.
The number of distractors had no effect. Segregating targets
from distractors does not draw on the resource used to track targets.
4:30–4:45 (247)
The Dynamics of Time-Sharing Control. PAMELA S. TSANG, JEFF
T. FLINN, BRYAN V. STORK, & JEFF M. DEVRIES, Wright State
University—This study examined the cognitive and motor control of
time-sharing a continuous tracking task and a discrete spatial processing
task. A dynamic task difficulty manipulation and the relative
priority manipulation were used to induce resource allocation between
the time-shared tasks. Difficulty of the tracking task was manipulated
dynamically within a trial. Task difficulty and response modality of
the spatial task were manipulated between trials. A microanalysis of
the continuous performance time locked to the response of the discrete
task was used to examine the structural constraints and strategic
control of the time-sharing performance. Forty-two subjects completed
approximately 20 h of task performance each.
4:50–5:05 (248)
The Role of Attention in Processing Rotary Motion Across Fixations.
ALEXANDER POLLATSEK, IBRAHIM DAHLSTROM-HAKKI, &