PT  - JOURNAL ARTICLE
AU  - Sebastian Sporn
AU  - Xiuli Chen
AU  - Joseph M Galea
TI  - Reward-based invigoration of sequential reaching
AID  - 10.1101/2020.06.15.152876
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.06.15.152876
4099  - http://biorxiv.org/content/early/2020/06/16/2020.06.15.152876.short
4100  - http://biorxiv.org/content/early/2020/06/16/2020.06.15.152876.full
AB  - Seeking reward is a powerful tool for shaping human behaviour. While it has been demonstrated that reward invigorates performance of simple movements, its effect on more complex sequential actions is less clear. In addition, it is unknown why reward-based improvements for discrete actions are transient, i.e. performance gains are lost once reward is removed, but appear long lasting for sequential actions. We show across three experiments that reward invigorates sequential reaching performance. Driven by a reward-based increase in speed, movements also exhibited greater coarticulation, smoothness and a closer alignment to a minimum jerk trajectory. Critically, these performance gains were maintained across multiple days even after the removal of reward. We propose that coarticulation, the blending together of sub-movements into a single continuous action, provides a mechanism by which reward can invigorate sequential performance whilst also increasing efficiency. This change in efficiency appears essential for the retention of reward-based improvements in motor behaviour.Competing Interest StatementThe authors have declared no competing interest.