SLEEP 2011 Abstract Supplement

A. Basic Science XI. Sleep Deprivation
Conclusion: Extended “recovery” sleep over the weekend reverses the
impact of one work-week of mild sleep restriction on sleepiness but
does not improve performance suggesting that complete performance
recovery may require more that just two days. In addition, it appears that
increased SWS in women compared to men protects them from the effect
of sleep loss on sleepiness and performance impairment, whereas it
enhances recovery from these effects of modest sleep loss.
0275
EFFECTS OF SLEEP DEPRIVATION ON NEURAL
CORRELATES OF RISK-TAKING
Rao H 1,2,3,4 , Luftig D 2 , Lim J 2 , Detre JA 1 , Dinges DF 2
1
Center for Functional Neuroimaging, Department of Neurology
and Radiology, University of Pennsylvania, Philadelphia, PA, USA,
2
Division of Sleep & Chronobiology, Department of Psychiatry,
University of Pennsylvania, Philadelphia, PA, USA, 3 Center
for Functional Brain Imaging, South China Normal University,
Guangzhou, China, 4 Department of Psychology, Sun Yat-Sen
University, Guangzhou, China
Introduction: Sleep deprivation (SD) can induce significant deficits in
vigilant attention, working memory, and executive function. However,
the effects of SD on risk-taking behavior are unclear, with some studies
reporting greater risk-taking behavior while others reporting no changes
following sleep loss. The present study used functional MRI with a
modified balloon analog risk task (BART) paradigm and examined the
effects of 24h of total sleep deprivation (TSD) on the neural correlates
of risk-taking.
Methods: A total of 27 healthy adults (13 male) were scanned on a Siemens
3T Trio scanner while performing a modified BART task at rested
baseline (BL) and after 24h of TSD, using a standard EPI sequence.
During the BART, subjects were required to sequentially inflate a virtual
balloon that could either grow larger or explode. Imaging data were
analyzed by SPM5.
Results: Behavioral data showed no changes of risk-taking propensity
from BL to SD (6.5 vs. 6.6, p>.7). Imaging data showed robust activation
in the mesolimbic, frontal, and visual pathway areas during the
BART both at BL and during SD, which replicated our previous studies.
Direct comparisons between these brain activation patterns indicated no
differences from BL to SD. However, direct comparisons between the
neural responses to the loss events (balloon explosion) showed reduced
activation in the left insula. Furthermore, at BL, both SPM whole brain
analysis and independent ROI analysis showing that insular and striatum
activation level negatively correlated with risk-taking propensity, which
also replicated our previous finding. However, such negative correlations
were not found after SD.
Conclusion: Consistent with literature, our data showed that 24h of
TSD did not change risk-taking behavior. However, significantly reduced
activation in the insula was observed during loss events following
TSD, which may reflect diminished negative emotional response to loss
outcomes during risk-taking. Moreover, the loss of negative correlations
between risk-taking behavior and activation level in insular and
striatum following TSD, suggesting that one night sleep loss can alter
neural mechanisms mediating inter-individual differences in risk-taking
propensity without actual behavioral changes. Overall, our data suggest
that sleep loss alters neural responses associated with risk-taking and
support the hypothesis that neuroimaging findings may be a precursor to
the behavioral changes following long-term sleep deprivation.
Support (If Any): This study is supported by Air Force Office of Scientific
Research Grant FA9550-05-1-0293, NIH Grant R01 HL102119;
in part by the National Space Biomedical Research Institute through
NASA NCC 9-58; and in part by NIH Grants CTRC UL1RR024134
and P30 NS045839.
0276
DIFFERENTIAL EFFECTS OF TOTAL SLEEP DEPRIVATION
ON REGIONAL CORTICAL ACTIVITY AT REST
AND DURING PSYCHOMOTOR VIGILANCE TEST
PERFORMANCE
Rao H 1,2,3,4 , Lim J 2 , Zhu S 1,4 , Wu W 1 , Hu S 1,2 , Detre JA 1 , Dinges DF 2
1
Center for Functional Neuroimaging, Department of Neurology
and Radiology, University of Pennsylvania, Philadelphia, PA, USA,
2
Division of Sleep & Chronobiology, Department of Psychiatry,
University of Pennsylvania, Philadelphia, PA, USA, 3 Center
for Functional Brain Imaging, South China Normal University,
Guangzhou, China, 4 Department of Psychology, Sun Yat-Sen
University, Guangzhou, China
Introduction: Sleep deprivation (SD) degrades multiple aspects of neurocognitive
performance. With few exceptions, recent neuroimaging
studies have reported hypo-activation in fronto-parietal regions during
various tasks following sleep loss. However, most of these studies focused
on the effects of SD on task-induced neural activation, while the
effects of SD on resting brain function without task requirements remain
unexplored. The present study used arterial spin labeling (ASL) perfusion
fMRI and examined the effects of 24h of total SD on brain function
at rest and during a psychomotor vigilance test (PVT).
Methods: A total of 31 healthy adults (16 male) were scanned on a Siemens
3T Trio scanner at non-task resting states and during the PVT after
normal sleep and after 24h of TSD, using a a pseudo-continuous ASL
sequence. Data were analyzed by SPM5. One mean resting CBF image
was generated for each condition from each subject before and after
TSD. Whole brain general linear modeling analysis was conducted.
Results: TSD significantly disrupted PVT performance (p