Examining the relationship among working memory, movement specific reinvestment and motor performance

Abstract

Working memory is a cognitive construct presented as a multi-component model depicted with a hierarchy. It comprises of the central executive, a supervisory processing system responsible for allocating attentional resource, and the short-term storage subsidiary systems named phonological loop, visuospatial sketchpad and episodic buffer. Working memory capacity (WMC) refers to the ability for top-down attentional control in managing the upkeep of temporary task-relevant information while inhibiting any bottom-up interference from irrelevant distractors. While the storage components are domain-specific towards verbal and visuospatial information, the processing nature of the central executive component is domain-general that deals with regulating both. Traditional theories of motor learning usually revolve around a progression through stages from novelty to expertise. How people learn the movement skills would greatly impact the way they subsequently perform. When learners use performance feedback to test hypotheses, working memory has been proposed to be responsible for the active retrieval of information and conscious motor processing. The differences between learning a skill explicitly or implicitly is in the amount of dependence on working memory and of accumulate declarative knowledge. During skill execution, the act of engaging working memory to monitor and control movement is termed “reinvestment”. The propensity to reinvest can be measured as a personality trait using the Movement-Specific Reinvestment Scale, MSRS, where a higher reinvestment tendency could hinder motor performance in situations when the working memory resource is subjected to competing demands. However, it has yet to be fully explained whether the underlying mechanism of skill performance involves individual differences in working memory capacity (WMC). The relationship between WMC and motor skill performance was investigated in two studies. The first study (Chapter 2) explored whether WMC and two conceptually related psycho-cognitive constructs (i.e. self-control capacity, movement-specific reinvestment) are associated in healthy adults. It was proposed that these three variables potentially influence motor performance. Findings indicated no significant correlation between self-control capacity and other variables. It also suggested that being older was associated with lower WMC and higher propensity for reinvestment. Expanding on the first exploratory study, the second experiment (Chapter 3) further examined how WMC and predisposed reinvestment propensity might affect performance of a fine motor skill under conditions of different cognitive demands in healthy older adults. Results revealed that people with high WMC had an overall advantage in fine motor skill performance across different conditions, and reinvestment appeared to have a negative association with performance such that high reinvestors performed worse but only among those who had low WMC. Overall findings were discussed with respect to methodological issues and the potentials of using the MSRS as a screening tool. Limitations and implications for future motor learning research were explained.