Sleep-dependent improvement in visuomotor learning: a causal role for slow waves.

摘要: A NUMBER OF STUDIES HAVE SHOWN THAT SLEEP CAN ENHANCE PERFORMANCE PREVIOUSLY LEARNED TASKS.1 SOME SUGGEST COMBINATION of both non-rapid eye movement (NREM) and rapid (REM) sleep is important,2,3 whereas others emphasize either NREM or REM sleep.4 However, assigning a role in memory enhancement to different stages sleep, combination stages, problematic because function likely depends on specific electrophysiologic events, such as slow waves spindles, rather than conventionally defined stages. Furthermore, most experiments so far have been correlative. Thus, it important determine whether sleep-dependent improvements performance are causally related features sleep. During virtually all cortical neurons undergo approximately 1-Hz oscillations, characterized by periods membrane depolarization firing activity (up states) followed hyperpolarization cessation (down states).5 Slow oscillations synchronized cortico-cortical connections,6,7 giving rise low frequency (0.5-4.5 Hz) high amplitude (often > 75 uV) that can be recorded the electroencephalogram (EEG). This wave (SWA, EEG power density between 0.5 4.5 Hz during sleep) thought marker need, at onset, declines further increased after deprivation, reduced naps.8–10 Recently, we used visuomotor adaptation task which subjects learn reach for targets visual display while cursor trajectory, unbeknownst them, rotated computer.11 We showed this was enhanced night but not an equivalent period wakefulness found, using high-density EEG, learning led local increase SWA over right parietal area involved rotation adaptation. Moreover, found postsleep improvement correlated with SWA.11 These results demonstrated regulated locally consequence raised possibility they may improvements. To test hypothesis current study, learned same task,11 were disrupted acoustic stimuli. investigated selective deprivation (SWD) prevented changes SWA.