The cost of correcting for error during sensorimotor adaptation

Area of Science:

• Neuroscience
• Cognitive Science
• Machine Learning

Background:

• Motor learning typically relies on a loss function to quantify error.
• The brain's process of learning from error is often slow and resource-intensive.

Purpose of the Study:

• To investigate the hypothesis that motor errors carry an implicit cost for the brain.
• To determine if modulating this implicit cost affects the rate and extent of sensorimotor adaptation.

Main Methods:

• A novel task combining saccade adaptation with motion discrimination was developed.
• The implicit cost of error was modulated by varying the coherence of the discrimination task.
• Pupil diameter was monitored as a physiological indicator of cognitive effort and cost.

Main Results:

• Increased error cost led to greater pupil dilation and enhanced motor learning.
• Conversely, decreased error cost resulted in pupil constriction and reduced learning from the same error magnitude.
• These findings demonstrate a direct link between the implicit cost of error correction and the efficacy of sensorimotor adaptation.

Conclusions:

• The act of correcting motor errors imposes an implicit cost on the brain, involving time and energy expenditure.
• Modulating this implicit cost significantly influences the brain's ability to learn and adapt from errors.
• Understanding and manipulating the implicit cost of error holds potential for optimizing motor learning strategies.