Task Complexity Modulates Sleep-Related Offline Learning in Sequential Motor Skills

Abstract

Recently, a number of authors have advocated the introduction of gross motor tasks into research on sleep-related motor offline learning. Such tasks are often designed to be more complex than traditional key-pressing tasks. However, until now, little effort has been undertaken to scrutinize the role of task complexity in any systematic way. Therefore, the effect of task complexity on the consolidation of gross motor sequence memory was examined by our group in a series of three experiments. Criterion tasks always required participants to produce unrestrained arm movement sequences by successively fitting a small peg into target holes on a pegboard. The sequences always followed a certain spatial pattern in the horizontal plane. The targets were visualized prior to each transport movement on a computer screen. The tasks differed with respect to sequence length and structural complexity. In each experiment, half of the participants initially learned the task in the morning and were retested 12 h later following a wake retention interval. The other half of the subjects underwent practice in the evening and was retested 12 h later following a night of sleep. The dependent variables were the error rate and total sequence execution time (inverse to the sequence execution speed). Performance generally improved during acquisition. The error rate was always low and remained stable during retention. The sequence execution time significantly decreased again following sleep but not after waking when the sequence length was long and structural complexity was high. However, sleep-related offline improvements were absent when the sequence length was short or when subjects performed a highly regular movement pattern. It is assumed that the occurrence of sleep-related offline performance improvements in sequential motor tasks is associated with a sufficient amount of motor task complexity.

Adult Gross Motor Learning and Sleep: Is There a Mutual Benefit?

“…Another reason could be that greater cognitive efforts induce fatigue, which can be successfully restored in sleep. The importance of task complexity was emphasized in a recent study [ 81 ] wherein the sleep-related improvements were absent with shorter sequences and more regular movement patterns.…”

Acquisition and consolidation of sequential footstep movements with physical and motor imagery practice

“…3 The plurality of gross motor paradigms developed so far has revealed inconsistencies in the findings, especially related to sleep-dependent consolidation. [4][5][6] For instance, Genzel et al 7 reported sleep-dependent gains in performance following sequential motor learning with the lower limbs (ie, dance choreography), while no-sleep benefits were observed following whole-body motor adaptation (ie, learning to ride an inverted-steering bicycle). 4 Nevertheless, it has been postulated that gross motor learning has to be sequentially structured, sufficiently challenging, and acquired explicitly in order to benefit from the sleep consolidation effect.…”

“…To address this issue, various fundamental and ecological gross motor paradigms have been used, from uni‐ and bimanual to whole‐body movements 3 . The plurality of gross motor paradigms developed so far has revealed inconsistencies in the findings, especially related to sleep‐dependent consolidation 4‐6 . For instance, Genzel et al 7 reported sleep‐dependent gains in performance following sequential motor learning with the lower limbs (ie, dance choreography), while no‐sleep benefits were observed following whole‐body motor adaptation (ie, learning to ride an inverted‐steering bicycle) 4 .…”

Exploring the Relationship Between Sleep Quality, Sleep-Related Biomarkers, and Motor Skill Acquisition Using Virtual Reality in People With Parkinson's Disease: A Pilot Study

“…Although most previous studies that assessed the effect of sleep on motor skill learning utilized simple tasks that focus on fine motor skills ( 13 ), evidence suggests that research findings on simple motor tasks cannot be generalized to gross and more complex motor skills ( 20 ). This is evident by studies that found the effect of sleep on motor skill learning differs with task complexity ( 40 ). In this current study, participants practiced a novel functional motor task that is similar to daily activities and is often practiced in a rehabilitation setting.…”