SLEEP 2011 Abstract Supplement

A. Basic Science IX. Learning, Memory and Cognition
0221
ROLE OF SLEEP IN VISUOMOTOR ADAPTATION MEMORY
CONSOLIDATION ASSESSED BY fMRI
Albouy G 1,2 , Sterpenich V 2 , Vandewalle G 1,2 , Darsaud A 2 , Gais S 2 ,
Rauchs G 2 , Desseilles M 2 , Dang-Vu T 2 , Degueldre C 2 , Maquet P 2,3
1
CRIUGM, University of Montreal, Montreal, QC, Canada, 2 Cyclotron
Research Centre, University of Liège, Liege, Belgium, 3 Department of
Neurology, University of Liège, Liege, Belgium
Introduction: The aim of this study was to determine the influence of
sleep on the cerebral correlates of visuomotor adaptation consolidation
using fMRI.
Methods: Thirty-one subjects were scanned during 2 separate sessions
referred to as the training and retest sessions while they performed a motor
adaptation task that required to reach for visual targets using a mouse
with the hand while adapting to systematic rotation imposed on the perceived
dot trajectory. After training, subjects were randomly assigned to
one of two groups according to whether they would be allowed to sleep
or be totally sleep deprived during the first post-training night. The retest
session took place 72h after training for subjects of both groups allowing
two recovery nights for sleep deprived subjects.
Results: Several parameters were used to measure performance (different
measures of speed and accuracy). For the training session, an ANO-
VA conducted on these parameters showed that performance improved
with practice in both groups similarly. The ANOVA on between-session
effects revealed a significant main effect of session and a group by session
interaction. Planned comparisons showed a stabilization of performance
in the sleep group but a significant deterioration of performance
in sleep deprived subjects between sessions. The main effect of practice
of the learned deviation during training and retest sessions recruited a
large cerebello-cortical network. Responses increased linearly with performance
improvement over the training session bilaterally in the putamen,
motor cortex, intraparietal sulcus, in the right cerebellum and left
medial prefrontal cortex. No changes in brain responses were observed
between training and retest sessions in sleepers as compared to sleepdeprived
subjects, suggesting a stability of the cerebral network used
during training to perform the task during retest. In contrast, in sleepdeprived
subjects as compared to sleepers, responses increased at retest
as compared to training in a cerebello-cortical network.
Conclusion: In sum, visuomotor adaptation consolidation is sensitive
to the sleep status: sleep led to a stabilization of performance whereas
performance deteriorated after sleep deprivation. The maintenance in
performance levels observed in sleepers was accompanied by a stabilization
of cerebral responses. In contrast, the deterioration of performance
in sleep-deprived subjects was illustrated by increased responses
in a cerebello-cortical network.
Support (If Any): This research was supported by F.N.R.S., Reine Elisabeth
Medical Foundation, ULg, P.A.I./I.A.P.
0222
EFFECTS OF SLEEP EXTENSION AND ACUTE SLEEP
DEPRIVATION ON COGNITIVE PERFORMANCE IN
HABITUAL SHORT SLEEPERS AND LONG SLEEPERS
Mograss MA 1,2 , Wielinga SH 1,3 , Baddam S 1 , Lockyer BJ 1 ,
Aeschbach D 1,2
1
Division of Sleep Medicine, Brigham & Women’s Hospital, Boston,
MA, USA, 2 Division of Sleep Medicine, Harvard Medical School,
Boston, MA, USA, 3 Psychology, Vrije Universiteit, Amsterdam,
Netherlands
Introduction: Previous studies found that short sleepers live under and
tolerate higher homeostatic sleep pressure than long sleepers. However,
it is not known whether this is reflected in trait-like differences in objective
performance. Here we investigated whether short and long sleepers
differ in sustained attention when exposed to high levels and low levels
of homeostatic sleep pressure.
Methods: Young (18-30 y) healthy short sleepers (n=7, habitual bedrest
9 h) completed a 28-day inpatient
protocol consisting of 4 days of habitual sleep (HS), 20 days of extended
(12 h) sleep (ES) opportunities, a 36h sleep deprivation (SD) interval
and 2 days of recovery sleep. The psychomotor vigilance task (PVT)
was administered several times throughout the wake episodes. Sleep
was recorded with polysomnography. Total sleep time (TST) and PVT
lapses (reaction times, RT > 500 ms), median speed (1/RT) and the interpercentile
range (IPRange, difference between the 90th and 10th percentile,
1/RT) were analyzed with a mixed model ANOVA with Group
(short, long) and Condition (HS Days 3-4, ES Days 21-23) as fixed effects.
For the SD interval, factors Group and Time awake were used.
Results: In the HS condition, TST was less for the short sleepers
(Mean±SE: 342±10 min) than for the long sleepers (535±8 min). During
the ES condition, TST increased in the short sleepers (533±18 min,
p < 0.001) but was unaffected in the long sleepers (530±16 min). In the
HS condition, there were no differences in PVT performance between
short and long sleepers. When given extended sleep opportunities, PVT
performance improved in the short sleepers (ES vs. HS: lapses 1.0±0.5
vs. 2.4±0.5; median speed 4.09±0.23 x 10-3 vs. 3.95±0.17 x 10-3 ms-1;
IPRange 1.46±0.12 x 10-3 vs. 1.86±0.12 x 10-3 ms-1, p < 0.001) but not
in the long sleepers. ANOVA on PVT performance during SD revealed
that the short sleepers showed fewer lapses (Group x Time awake, p <
0.001) and a more stable response pattern (IPRange: Group, p < 0.04)
than the long sleepers, particularly in the latter part of the SD.
Conclusion: Differences between short and long sleepers in sleep duration
may reflect a trait-like difference in the tolerance to homeostatic
sleep pressure rather than in the capacity to sleep. Short sleepers seem to
possess a ‘cognitive reserve’ that becomes apparent under very low and
very high levels of homeostatic sleep pressure.
Support (If Any): This study was supported by grants RO1HL077399
and M01 RR02635 and UL1 RR025758. MM was supported by a NIH
postdoctoral training fellowship T35GM12453.
0223
SLEEP DEPRIVATION IMPAIRS EFFECTIVE
CONNECTIVITY DURING RESTING STATE
Piantoni G 1 , Cheung BP 2 , Van Veen BD 2 , Romeijn N 1 , Riedner BA 3 ,
Tononi G 3 , Van Der Werf YD 1,4 , Van Someren EJ 1,5
1
Sleep & Cognition, Netherlands Institute for Neuroscience,
Amsterdam, Netherlands, 2 Electrical and Computer Engineering,
University of Wisconsin, Madison, WI, USA, 3 Psychiatry, University
of Wisconsin, Madison, WI, USA, 4 Anatomy and Neurosciences, VU
University Medical Center, Amsterdam, Netherlands, 5 Integrative
Neurophysiology, VU University, Amsterdam, Netherlands
Introduction: Slow waves are a landmark of deep sleep and are thought
to play a key role in preparing our brain to process new information.
Slow waves are thought to travel over the cortex mostly in an anterior-toposterior
direction and a recent study has identified the cingulate cortex
as one of their favorite routes. During wakefulness, cingulate cortices
are also major hubs of information exchange in the brain. Therefore,
we hypothesize that, without the beneficial effect of slow wave activity
(SWA), the transfer of information along the cingulate cortex during the
following day is reduced and, because of the directionality in SWA, the
reduction is more pronounced in one direction than the other.
Methods: As a measure of effective connectivity, we used Granger Causality
(GC) on high-density EEG between preselected sources during
wakefulness, after normal sleep and sleep deprivation. The information
flow of the brain was manipulated by asking 8 participants to keep their
eyes open or closed for two minutes, while EEG signal was recorded
from 64 electrodes. GC was assessed between three regions along the
cingulate cortex for both directions: anterior-to-posterior and posteriorto-anterior.
Results: After normal sleep, GC from the posterior to the anterior cingulate
cortex was higher during eyes-open than during eyes-closed, in
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SLEEP, Volume 34, Abstract Supplement, 2011