Effects of proactive control and reward incentives on the inhibition of sequentially linked motor actions

Efficient behavior demands the ability to link multiple individual actions into coherent behavioral sequences, but the repetition of action sequences in the same context can result in behavior becoming inflex- ible and resistant to change. Proactive control and reward incentives exert beneficial effects on inhibitory control of single, isolated motor responses. However, it is unknown whether these factors can also enhance flexible switching of responses that are embedded within learned action sequences. In three experiments, I investigated the effects of proactive control and reward incentives on participants’ ability to switch responses on a motor sequence learning task that elicits a high number of slips of action on sequence-change trials. Providing task-informative cues and reward incentives led to significant reductions in the number of action slips. However, slips of action continued to occur frequently despite the engagement of proactive con- trol. Furthermore, there was no effect of cueing or reward incentives on the efficiency of response switching. These findings show that proactive control and reward incentives can enhance the participants’ ability to make flexible adaptations to learned sequences of motor actions while also highlighting the limitations of such modulatory effects.