SLEEP 2011 Abstract Supplement

A. Basic Science IX. Learning, Memory and Cognition
0215
SLOW WAVE SLEEP PLAYS A ROLE IN THE TRANSFER
OF STATISTICAL INFORMATION FROM THE MEDIAL
TEMPORAL LOBE TO THE STRIATUM DURING
CONSOLIDATION
Durrant SJ, Cairney S, Lewis PA
School of Psychological Sciences,, University of Manchester,
Manchester, United Kingdom
Introduction: Memory consolidation during sleep has been increasingly
documented in the last decade. Perceptual learning, and in particular
the important field of exposure learning, is currently under-represented
in this research. Here we studied the impact of sleep upon abstraction of
statistical patterns from exposure learning with behavioural, sleep and
functional imaging measures.
Methods: 36 participants divided equally between Sleep and Wake
groups took part in a statistical learning task which involved exposure
to a structured auditory stream followed by an immediate-recall session,
and after a consolidation gap a delayed-recall session, in both of which
they were required to identify short sequences with a structure similar
to the exposure stream. The Sleep group were trained and immediately
tested at 3pm on Day 1. Their overnight sleep was then monitored with
polysomnography, and they were retested in the fMRI scanner at 3pm
on Day 2. Participants in the Wake Group were trained and immediately
tested at 3pm and then placed immediately in an fMRI scanner for the
second test session, with no consolidation delay.
Results: Behaviourally, identification of structured sequences improved
more in the Sleep than the Wake group, and this improvement correlated
with the amount of slow wave sleep obtained. Functionally, we found a
decreased dependence on the medial temporal lobe and increased activation
of the striatum after sleep during correct identification of structured
sequences. Importantly, this functional shift correlated with the amount
of slow wave sleep obtained.
Conclusion: Our findings broadly support the standard model of consolidation
and highlight the importance of slow wave sleep in this process.
They also suggest the existence of a new form of trade-off between
the medial temporal lobe and the striatum similar to a classical training
effect, but which here is dependent on sleep.
0216
THE INFLUENCE OF SLEEP INERTIA ON ATTENTION
SWITCHING
Dear TB, Burke TM, Wright KP
Integrative Physiology, University of Colorado at Boulder, Boulder,
CO, USA
Introduction: Sleep inertia (SI), the grogginess felt upon awakening,
is associated with cognitive performance impairments. The greatest impairments
occur immediately upon awakening and dissipate over the
next few hours. We sought to extend the understanding of SI on cognitive
performance by assessing the impact on attention switching between
spatial orientation and mathematical tasks.
Methods: Performance of ten healthy subjects [4 females
(21.5±3.5yr;mean±SD)] on the Switching Task was assessed within
1min of scheduled awakening and every 10min thereafter until 1h
awake. The Switching Task, known to be sensitive to sleep deprivation,
cued subjects to switch attention between two simultaneously presented
tasks. Subjects either mentally rotated a mannequin and indicated the
hand holding a specified stimulus or completed a simple mathematical
task and indicated if the sum was greater or less than five. Transitions
between tasks were analyzed using 1/mean correct reaction time
while accuracy and speed were analyzed with throughput for each task.
Data were analyzed as deviation from the mean with repeated measure
ANOVA.
Results: Significant main effects of time for the mannequin throughput
and transitions to the mannequin task across SI tests were observed
(p