Children's initial sleep‐associated changes in motor skill are unrelated to long‐term skill levels

Abstract

Sleep is considered to support the formation of skill memory. In juvenile but not adult song birds learning a tutor's song, a stronger initial deterioration of song performance over night-sleep predicts better song performance in the long run. This and similar observations have stimulated the view of sleep supporting skill formation during development in an unsupervised off-line learning process that, in the absence of external feedback, can initially also enhance inaccuracies in skill performance. Here we explored whether in children learning a motor sequence task, as in song-learning juvenile birds, changes across sleep after initial practice predict performance levels achieved in the long run. The task was a serial reaction time task (SRTT) where subjects had to press buttons which were lighted up in a repeating eight-element sequence as fast as possible. Twenty-five children (8-12 years) practised the task in the evening before nocturnal sleep which was recorded polysomnographically. Retrieval was tested on the following morning and again 1 week later after daily training on the SRTT. As expected, changes in response speed over the initial night of sleep were negatively correlated with final performance speed after the 1-week training. However, unlike in song birds, this correlation was driven by the baseline speed level achieved before sleep. Baseline-corrected changes in speed or variability over the initial sleep period did not predict final performance on the trained SRTT sequence, or on different sequences introduced to assess generalization of the trained behaviour. The lack of correlation between initial sleep-dependent changes and long-term performance might reflect that the children were too experienced for the simple SRTT, possibly also favouring ceiling effects in performance. A consistent association found between sleep spindle activity and explicit sequence knowledge alternatively suggests that the expected correlation was masked by explicit memory systems interacting with skill memory formation.

Different post-training processes in children's and adults' motor skill learning

“…; Z = 2.25, p < .05). As in previous studies [19], early enhancement in children’s performance times was correlated with lower end-of-training performance, r(45) = -.47, p < .001. Correlations between initial or end-of-training performance and later gains (i.e., from delay to 2 weeks post-training) are insignificant.…”

“…Twenty-four hours post-training enhancement is not related to initial skill level [8], suggesting that at least partially different neuronal processes subserve a few-hours post-training and 24 hours post-training performance enhancements in children. This association suggests that unlike later enhancements, which are more related to long-term memory processes, the early enhancement may be related to processes that enhance performance during training [15, 19], and may reflect neuronal processes subserving the experience-driven modification of the motor system [20, 39–41].…”

“…It is not clear if the earlier expression of enhancement also appears in younger children, relative to young adults, and in paradigms different from the 5-item sequence tapping tasks. Furthermore, it is not clear if early post-training gains are associated with the initial level of performance, as are training gains [8, 19]. It is also not clear if these gains are transient or stable across longer (weeks) retention intervals, because previous studies limited the report to 24 h post-training.…”

How do children with autism spectrum disorder form gist memory during sleep? A study of slow oscillation–spindle coupling

“…A spindle was detected whenever this smoothed moving RMS window exceeded an individual threshold (1.5 SD s of the filtered signal in the respective channel) for 0.5–3 s. The detection algorithm has been used in several previous studies (e.g. [ 46 , 47 ]). Its validity is routinely checked in each experiment by experienced staff, by visually inspecting the detected spindles.…”

Nonrapid eye movement sleep characteristics and relations with motor, memory, and cognitive ability from infancy to preadolescence

“…In school‐age children, Zinke et al. (2017) found the number of spindles, and spindle density, were positively associated with next day performance for explicit sequence recall of a motor sequence, but spindle features were not associated with long‐term performance. Astill et al.…”