Simultaneous motor preparation and execution in a last-moment reach correction task

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• Motor preparation typically precedes movement and influences its characteristics.
• Previous research primarily focused on preparation in delayed reaching tasks.
• The role of motor preparation in online movement adjustments remains less understood.

Purpose of the Study:

• To investigate if motor preparation is engaged during mid-reach modifications.
• To examine neural activity in motor and premotor cortex during reactive reaching tasks.
• To determine if preparatory neural signals contribute to online movement corrections.

Main Methods:

• Monkeys performed reaching movements to targets that could unexpectedly change location before movement onset.
• Neural activity was recorded from the motor cortex and dorsal premotor cortex.
• Analysis focused on identifying neural patterns related to movement timing and target location during preparation and execution.

Main Results:

• Neural activity signaling movement initiation predicted monkeys' responses to target jumps on a trial-by-trial basis.
• Distinct neural patterns were identified for movement timing (when to reach) and target location (where to reach).
• Following a target jump, neural activity exhibited changes in both preparatory and movement-related dimensions, even with minimal initial error.

Conclusions:

• The findings suggest that the motor preparation mechanisms used in delayed reaching are also involved in correcting ongoing movements.
• Motor preparation and execution can occur concurrently.
• This research provides insights into the neural basis of adaptive motor control and online movement adjustments.