An investigation into the neurocognitive processes underlying motor imagery

This thesis investigates the neurocognitive (especially, attentional) mechanisms underlying “motor imagery” (MI), a cognitive ability that involves consciously performing an action in the mind without physically executing associated movements. Research shows that the systematic use of MI (or “mental practice”; MP) can enhance the functioning of motor systems and improve skilled behaviour (e.g., in sport, medicine, music and neurorehabilitation). The most popular explanation for this MI/MP effect on skill learning/performance stems from motor simulation theory (MST; Jeannerod, 1994, 2001, 2006a). Briefly, MST claims that MI and physical movement are “functionally equivalent” because they purportedly share motor representations, activate similar neuroanatomical structures, and rely on the same functional mechanisms. Unfortunately, despite their seminal nature, the tenets of MST have received surprisingly little critical scrutiny. Therefore, the cognitive mechanisms alleged to underlie MI remain unclear. The three papers reported in this thesis sought to fill this gap in research on MI. The first paper critically reviews evidence cited for MST and evaluates the extent to which it accounts for the cognitive mechanisms underlying MI. The second paper investigates the role of attentional/mental effort (as measured by pupil dilation) in expert pianists’ ability to maintain vivid and accurate MI of movements of differing complexity. It concludes that imagined movements that are both complex and fast may require levels of attention that are not sufficiently allocated during MI for accurate performance. The third paper investigates the effect of movement inhibition on attentional processes (as measured by pupil dilation) during MI. It suggests that the inhibitory mechanisms underlying MI may be implemented by multiple routes. Following a critical discussion of these findings, methodological limitations are acknowledged and potentially fruitful new directions for research on MI are identified.