SLEEP 2011 Abstract Supplement

A. Basic Science IX. Learning, Memory and Cognition
Introduction: Sleep deprivation (SD) at retrieval enhances false memories
(FM), while sleep satiety at retrieval reduces FM. Existing literature
about FM formation does not examine effects of type of SD or interaction
of gender and SD on FM formation. Here, we describe the effects
of gender and type of SD on recognition and FM formation rates in an
object memory task.
Methods: Thirty-nine subjects were assigned to either 30h total sleep
deprivation (TSD, n=21, 12F, age=24.6±4.8) or partial sleep deprivation
(PSD, 4h TIB/night for 5 nights; n=18, 11F, age=25.1±5.8) and administered
the Deese-Roediger-McDermott Shapes task while well-rested
(WR; 9h TIB/night for 6 nights) and during SD (counterbalanced order).
During testing, four types of shapes were presented: true shapes (shapes
previously shown), lures (probes for FM), different color foils (DC: difof
such replay in humans has not yet been directly demonstrated. Here
we studied patients who exhibit overt behaviors during sleep to test
whether sequences of movements trained during the day may be spontaneously
reenacted by the patients during sleep.
Methods: We recruited 19 sleepwalkers (who displayed complex and
purposeful behaviors emerging from non REM sleep), 20 patients with
REM sleep behavior disorder (who enacted their dreams in REM sleep)
and 18 healthy controls. Continuous video sleep recordings were performed
during sleep following intensive training on a sequence of large
movements (learned during a variant of the serial reaction time task).
Results: Both patient groups showed learning of the intensively trained
motor sequence after sleep. We report the re-enactement of a fragment
of the recently trained motor behavior during one sleepwalking episode.
Conclusion: This study provides, to our knowledge, the first evidence
of a temporally-structured replay of a learned behavior during sleep
in humans. Our observation also suggests that the study of such sleep
disorders may provide unique and critical information about cognitive
functions operating during sleep.
Support (If Any): The study was funded by the Brain Research Federation
(FRC) and ADOREP (grants to I.A.), France Parkinson and the
French Sleep Society (SFRMS) (grants to D.O.), and by the Swiss National
Science Foundation (grants to S.S.). I.C. was awarded an European
Network of Sleep Training Laboratories (ENSTL) grant from the
European Sleep Research Society (ESRS) for this project. The funders
had no role in study design, data collection and analysis, decision to
publish, or preparation of the manuscript.
0252
SLEEP AND MEMORY CONSOLIDATION: META-ANALYSIS
OF THE LITERATURE
Porte HS
Psychology, Cornell University, Ithaca, NY, USA
Introduction: In the investigation of sleep and memory processing, scientific
disagreement persists. To identify origins of disagreement, metaanalysis
of the literature was undertaken.
Methods: 1. Each of 30 representative studies was categorized according
to sleep state (Stage 2, slow wave sleep, or REM) most closely associated
with consolidation of an experimental learning task. To correctly
categorize certain studies, spindle density was accorded category status.
Human studies and rat studies were examined separately. 2. Under each
stage rubric (e.g., SWS: Human), studies were summarized according
to independent variable (e.g., “Retention interval: early sleep or wake
vs. late sleep or wake”); dependent variable (e.g., “visual texture discrimination”);
result (e.g., “Early sleep and in particular early plus late
sleep facilitate learning”); and author-designated memory category (e.g.,
“visual procedural”).
Results: Only sleep state categories and the relations of these to author-designated
memory categories are reported here. Human Studies:
Stage 2 and/or spindle density facilitates or is increased by motor procedural
learning; is decreased by declarative learning (word pairs with
retroactive interference). Spindle density increases during the first 270
minutes of sleep after intensive verbal declarative (word pair) training.
SWS (early sleep) facilitates verbal declarative, nonverbal declarative,
and visual implicit/visual procedural learning; transfers implicit to explicit
learning (“insight”). Stage REM (late sleep) facilitates procedural,
visual implicit, verbal nondeclarative, nonverbal nondeclarative, declarative,
and episodic learning. Rat Studies: Spindle density increases
during the first hour of sleep after declarative (odor + reward) learning.
SWS replays spatial learning. Stage REM facilitates spatial learning and
complex operant learning; replays spatial learning; interacts with fear
conditioning.
Conclusion: Disagreement in the sleep and memory literature originates
in factors ranging from historical inconsistencies in nomenclature to unitary
mapping of memory category onto sleep state. Consistencies within
and across human and animal data, and recent emphases on the neural
state architecture of sleep, may augur paradigm convergence.
0253
EFFECTS OF SLEEP ON KNOWLEDGE INTEGRATION AND
AUTOMATICITY OF PROCESSING
Tham E, Lindsay S, Gaskell G
Department of Psychology, University of York, York, United Kingdom
Introduction: Recent research indicates that sleep benefits consolidation
of novel words. We investigated effects of sleep on knowledge integration
and automaticity of processing using Size Congruity Effects
(SCEs) and Semantic Distance Effects (SDEs) in second-language
learning. SCEs occur when participants compare semantic size or physical
font size of written-word pairs: correct responses are faster when
both dimensions are congruent. SDEs involve swifter semantic size
judgements for distant items (e.g., BEE-COW) compared with closer
items (e.g., DOG-COW). These effects reflect automaticity in activating
meanings; well-integrated novel words may exhibit greater SCE
and SDE effects than unintegrated items. We predicted that participants
who slept between learning and testing would show stronger SCE/SDEs
for Mandarin characters learnt during training than participants who remained
awake for a comparable duration.
Methods: Participants learned six Mandarin characters referring to
different-sized animals in the evening (N=12) or morning (N=12), and
tested after 12-hours of sleep or wake. During testing, participants saw
item-pairs differing in physical (font) size and semantic (referent) size.
In half the trials, relative physical and semantic sizes were congruent and
in half they were incongruent. In separate tasks, participants selected the
physically or semantically larger item. Both tasks were conducted using
newly learned Mandarin characters; equivalent tasks using English stimuli
provided baseline performance and controlled for circadian effects.
Results: Repeated-measures ANOVAs revealed significant interactions
between sleep and congruity, and between sleep and semantic distance
for semantic comparisons of Mandarin characters, whereby participants
who slept exhibited stronger SCEs and SDEs than those who remained
awake. There were no equivalent interactions between sleep and congruity
or semantic distance for English stimuli.
Conclusion: Participants who slept between training and testing showed
stronger SCEs and SDEs for Mandarin semantic comparisons. This suggests
that sleep is associated with enhanced automaticity in second-language
learning, supporting an integrative role for sleep in declarative
memory consolidation.
0254
GENDER EFFECTS ON FALSE MEMORY FORMATION
Ta J 1,3 , McDevitt EA 1,4 , Campos M 1,3 , Drummond SP 1,2,4
1
Research Services, VA San Diego Healthcare System, San Diego, CA,
USA, 2 Psychology Services, VA San Diego Healthcare System, San
Diego, CA, USA, 3 Department of Psychology, University of California,
San Diego, La Jolla, CA, USA, 4 Department of Psychiatry, University
of California, San Diego, La Jolla, CA, USA
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SLEEP, Volume 34, Abstract Supplement, 2011