title: Sex differences in sleep-dependent perceptual learning.
abstract: Sex differences in learning and memory suggest differences between men and women in mechanisms of neural plasticity. Such differences have been reported in a variety of explicit memory tasks, but implicit memory has not been studied in this context. We investigated differences between men and women in offline consolidation of perceptual learning (PL) of motion direction discrimination. Initially, discrimination thresholds were measured for two opposite directions of motion, followed by approximately 40 minutes of training on one of the directions. During a post-training consolidation period, subjects either took a nap or remained awake. Thresholds were then reassessed for both directions of motion. We found that rapid eye movement (REM) sleep facilitates consolidation of PL but that the pattern of specificity in the REM condition differed between men and women. PL for men whose naps contained REM sleep was highly specific to the trained direction of motion, whereas REM sleep in women resulted in generalized learning to the untrained direction as well as to a novel direction that was not previously tested. Moreover, for subjects in the REM condition, men exhibited greater PL than women for the trained direction. Our findings provide the first evidence of sex differences in the magnitude and specificity of PL and in the role of REM sleep in implicit learning. Our results have important implications for optimization of educational and training strategies designed for males and females.
authors.affiliation: Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States; Veterans Affairs San Diego Healthcare System, Research Service, 3350 La Jolla Village Drive, 9116a, San Diego, CA 92161, United States. Electronic address: mcdevitt@ucr.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: McDevitt
authors.affiliation: Helen Wills Neuroscience Institute, School of Optometry, and Vision Science Graduate Group, University of California, Berkeley, 360 Minor Hall #2020, Berkeley, CA 94720, United States. Electronic address: arokem@gmail.com.
authors.forename: Ariel
authors.initials: A
authors.lastname: Rokem
authors.affiliation: Helen Wills Neuroscience Institute, School of Optometry, and Vision Science Graduate Group, University of California, Berkeley, 360 Minor Hall #2020, Berkeley, CA 94720, United States. Electronic address: masilver@berkeley.edu.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Silver
authors.affiliation: Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States; Veterans Affairs San Diego Healthcare System, Research Service, 3350 La Jolla Village Drive, 9116a, San Diego, CA 92161, United States. Electronic address: smednick@ucr.edu.
authors.forename: Sara C
authors.initials: SC
authors.lastname: Mednick
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D004193:Discrimination Learning / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D017286:Polysomnography; D012684:Sensory Thresholds / Q000502:physiology; D012737:Sex Factors; D012895:Sleep, REM / Q000502:physiology*; D055815:Young Adult
keywords: Generalization; Memory consolidation; Napping; Perceptual learning; REM sleep; Specificity