David Thura (IMPACT CRNL)
The mechanisms of reward optimization in decision-making have generally been studied separately from those in movement control. However, during natural behavior, animals are often faced with decisions about actions, and the time they invest in deciding and acting must be optimized together rather than separately to ensure an adapted rate of reward. This implies that the control of decisions and actions share common principles, and perhaps involve overlapping neural circuits.
In this presentation I will first describe behavioral experiments in which humans and monkeys performed visually-guided choices between reaching movements. Results indicate that decision urgency strongly influences reaching kinematics, suggesting that a shared regulation signal determines both decision speed and movement vigor. I will then demonstrate that this shared regulation is supported by neurophysiological recordings in the monkey cortico-basal ganglia network. Secondly, I will describe other behavioral experiments in which reaching constraints are manipulated in blocks of trials, and effects of motor costs on subjects’ decision strategy are assessed. The results suggest a flexible mechanism allowing to maintain the rate of reward in a costly context or after making errors.
Together, the data support a strong and adaptive level of integration of decision-making and movement control during goal-oriented behavior.
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