Dr Joseph Galea: Reward in the motor system

A seminar from Dr Joe Galea, University of Birmingham. Room 1.33-1.34. Hosted by F Mashtaq

The impact of reward on motor behaviour has gathered much interest over the last decade as beneficial effects have been shown on execution, learning and retention. To explain such results, it has been suggested that reward leads to dopamine-dependent habitual-like behaviour, making it a promising tool for rehabilitation. This talk introduces an alternative hypothesis which proposes that the beneficial effects of reward are mainly driven by the greater engagement of cognitive control. Using a range of behavioural tasks, we show that reward-based improvements in memory retention are driven by the development and expression of a cognitive-strategy that is strongly linked to spatial working memory capacity. Next, we show that the trial-by-trial effects of reward on reaching performance (enhanced accuracy and speed) can be, at least partially, explained through increased muscle co-contraction, another possible cognitive-strategy. Finally, we show that reward-based effects on complex sequential actions have initial transient properties, more akin to cognitive control, but which over time appear to become more habitual (reward-based motor coarticulation). These conclusions are discussed in the context of rehabilitation and specifically in the importance of accounting for reward-based cognitive-control mechanisms.