Exploration biases how forelimb reaches to a spatial target are learned

Area of Science:

• Neuroscience
• Motor Control
• Computational Neuroscience

Background:

• The brain learns diverse motor strategies for actions like reaching.
• Understanding factors biasing strategy learning is crucial for neural bases of movement research.

Approach:

• Introduced a novel spatial forelimb target task for head-fixed mice using a joystick.
• Analyzed learning trajectories, strategy bias (direction vs. endpoint), and sensorimotor cortex involvement.
• Utilized probe tests with shifting start positions and reinforcement learning models for comparison.

Key Points:

• Mice successfully learn covert target reaches, refining exploratory trajectories into controlled movements.
• Learned strategies were biased towards either direction or endpoint control, dependent on individual mice.
• Endpoint learning bias correlated with early spatial directional variability during exploration.

Conclusions:

• Sensorimotor cortex is essential for executing learned forelimb reaches.
• Individual exploratory behavior during training significantly biases the motor control strategies acquired.
• Reinforcement learning models replicate the correlation between exploration variability and learned strategy.