Single reach plans in dorsal premotor cortex during a two-target task

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Science

Background:

• Individuals often face situations with multiple potential actions but must delay execution pending further information.
• A key question in movement science is whether the brain simultaneously plans all options or selects one and switches if necessary.

Purpose of the Study:

• To investigate whether the dorsal premotor cortex plans single or multiple movements during delayed-response tasks.
• To determine how neural activity reflects the deliberation process between potential movement options.

Main Methods:

• Simultaneous recording of neuronal population activity in the macaque dorsal premotor cortex.
• Tracking moment-by-moment neural activity during deliberation between two potential reach targets.
• Analysis of neural signals to identify movement plans and their relationship to subsequent behavior.

Main Results:

• Neural activity consistently indicated a single movement plan at any given time, with varying degrees of target preference.
• Initial movement plans accurately predicted monkey behavior in both free-choice and incorrect cued trials.
• Evidence suggests a bias towards one option early in the decision-making process.

Conclusions:

• The dorsal premotor cortex appears to plan only one movement option at a time.
• Decision-making in delayed-response scenarios is significantly shaped by the initial response to available movement options.
• This finding challenges models that propose simultaneous planning of all potential actions.