Sensory expectations shape neural population dynamics in motor circuits.

Area of Science:

• Neuroscience
• Motor Control
• Computational Neuroscience

Background:

• Motor cortical activity during preparation is well-studied for self-initiated actions.
• Movements are often triggered or corrected by sensory inputs from body disturbances.
• Predictable disturbances can be prepared for to improve movement precision.

Purpose of the Study:

• To investigate if expectations about sensory inputs influence preparatory activity in motor circuits.
• To determine how probabilistic cues about mechanical perturbations affect movement preparation and responses.
• To explore the neural basis of incorporating sensory expectations into motor preparation.

Main Methods:

• High-density neural recordings in humans and monkeys.
• Probabilistic cueing of mechanical perturbation direction.
• Neural network modeling coupled with a biomechanical arm model.

Main Results:

• Humans and monkeys incorporated sensory expectations into movement preparation, improving corrective responses.
• Preparatory signals related to sensory expectations were widespread across brain areas, including motor cortex.
• The neural geometry of these signals scaled with perturbation probability and reflected early sensory input processing.

Conclusions:

• Preparatory activity in motor circuits configures responses not only for self-initiated actions but also for sensory-triggered events.
• Sensory expectations are integrated into motor preparation, leading to more efficient responses to predictable disturbances.
• Neural mechanisms exist to rapidly process sensory input and adjust motor commands based on expectations.