Sleep and the Time Course of Motor Skill Learning

Abstract

Growing evidence suggests that sleep plays an important role in the process of procedural learning. Most recently, sleep has been implicated in the continued development of motor-skill learning following initial acquisition. However, the temporal evolution of motor learning before and after sleep, the effects of different training regimens, and the long-term development of motor learning across multiple nights of sleep remain unknown. Here, we report data for subjects trained and retested on a sequential finger-tapping task across multiple days. The findings demonstrate firstly that following initial training, small practice-dependent improvements are possible before, but not following the large practice-independent gains that develop across a night of sleep. Secondly, doubling the quantity of initial training does not alter the amount of subsequent sleep-dependent learning that develops overnight. Thirdly, the amount of sleep-dependent learning does not correlate with the amount of practice-dependent learning achieved during training, suggesting the existence of two discrete motor-learning processes. Finally, whereas the majority of sleep-dependent motor-skill learning develops during the first night of sleep following training, additional nights of sleep still offer continued improvements.

Offline consolidation in implicit sequence learning

“…"savings" rather than "enhancement") than participants who stayed awake for a comparable length of time, the difference evened out once the awake group had their normal night's sleep. The Walker, Brakefield, Seidman, et al (2003) found increasingly stronger sequencespecific consolidation with longer intervals, however, in their study sequence knowledge was essentially explicit. Hence, in Experiment 2, we investigated whether the consolidation of implicit sequence learning might benefit from more time by using a one week interval between sessions.…”

“…Evidence of offline motor memory consolidation in conjunction with explicit sequence learning was found when participants performed a finger-tapping task with two training sessions (Doyon et al, 2009;Walker, Brakefield, Morgan, Hobson, & Stickgold, 2002;Walker, Brakefield, Seidman, et al, 2003). Specifically, after one night's sleep, with no further practice between sessions, participants showed marked improvements in speed and accuracy.…”

“…Sequence-specific learning refers to faster responses as a result of the acquisition of sequence-specific knowledge. Many serial reaction time task (SRTT) studies to date have not distinguished between these two components of performance (but see Hallgato et al, 2013;Németh et al, 2010;Song, Howard, & Howard, 2007, for exceptions).Evidence of offline motor memory consolidation in conjunction with explicit sequence learning was found when participants performed a finger-tapping task with two training sessions (Doyon et al, 2009;Walker, Brakefield, Morgan, Hobson, & Stickgold, 2002;Walker, Brakefield, Seidman, et al, 2003). Specifically, after one night's sleep, with no further practice between sessions, participants showed marked improvements in speed and accuracy.…”

Where is the classic interference theory for sleep and memory?

“…In contrast to the declarative system, evidence for the reliance of procedural memory on sleep in humans has been incredibly robust, and currently offers the most promising and informative model of sleep-dependent learning (Buchegger & Meier-Koll 1988;Fischer et al 2002;Gais et al 2000;Karni et al 1994;Smith & MacNeill 1994;Stickgold et al 2000a;2000b;Walker et al 2002;2003b). In the light of this consistency, we will now focus on recent advances in understanding the specific stages of procedural memory development, and discuss the differing contributions that time, wake, and sleep offer.…”

“…2A). However, several new studies suggest that consolidation of procedural memory is not simply determined by time per se, but instead, is more strictly determined by time spent in specific brain states such as wake or sleep, or even certain stages of sleep (Brashers-Krug et al 1996;Fischer et al 2002;Gais et al 2000;Karni et al 1994;Muellbacher et al 2002;Shadmehr & Brashers-Krug 1997;Stickgold et al 2000a;2000b;Walker et al 2002;2003b). Yet, this premise rests critically on one issue: the definition of consolidation.…”