SLEEP 2011 Abstract Supplement

A. Basic Science IX. Learning, Memory and Cognition
0218
MEN NEED A NAP TO SHOW PERCEPTUAL LEARNING,
BUT WOMEN DO NOT
McDevitt EA 1,2 , Rokem A 3 , Silver MA 3,4 , Mednick SC 1,2
1
Psychiatry, University of California, San Diego, La Jolla, CA, USA,
2
Research Service, VA San Diego Healthcare System, La Jolla, CA,
USA, 3 Helen Wills Neuroscience Institute, University of California,
Berkeley, Berkeley, CA, USA, 4 School of Optometry, University of
California, Berkeley, Berkeley, CA, USA
Introduction: Sex differences in performance have not been found under
sleep deprivation conditions, although well-rested men generally
exhibit better spatial orientation and reaction times compared to women.
Perceptual learning of texture discrimination is sleep-dependent and
specific to the trained condition. Daytime naps improve task performance
within the same day. We employed a nap paradigm to compare
the benefits of sleep for perceptual learning of motion discrimination in
men and women.
Methods: 95 healthy subjects (age=20.2±2.15yrs) completed a motion
direction discrimination task. At 9AM, thresholds were obtained for
trained and untrained directions of motion, followed by 40min of training.
Subjects were classified into one of two groups: naps (N=51,36F)
(75min; polysomnography-recorded) and no-nap (N=44,22F). At 4PM,
thresholds were re-tested. Learning was computed for two conditions
(trained/untrained directions) for each group (nap/no-nap). We hypothesized
nappers would show more learning than non-nappers and men
would outperform women.
Results: GroupxCondition ANOVA showed a main effect of group on
learning (p=.03). Men and women displayed equivalent task performance.
However, sex-specific ANOVAs revealed men who napped exhibited
increased learning in the trained direction of motion relative to
men who did not nap (p=.03). There was no effect of napping in women.
Post-hoc t-tests showed women learned both with (p