Information-theory analysis of mouse string-pulling agrees with Fitts's Law: Increasing task difficulty engages...

Area of Science:

• Neuroscience
• Behavioral Science
• Biomechanics

Background:

• Mouse string pulling is a model for skilled motor behavior, assessing neurological and cognitive function.
• The task involves coordinated snout and hand movements to retrieve a string.
• Understanding motor control requires analyzing how task parameters affect movement execution.

Purpose of the Study:

• To investigate how varying string diameter impacts the time allocation and movement characteristics in mouse string pulling.
• To analyze the relationship between task difficulty and sensorimotor strategies using quantitative movement analysis.

Main Methods:

• Utilized 2D markerless pose estimation with deep neural networks for tracking mouse movements.
• Employed MATLAB for image segmentation and heuristic algorithms for object tracking.
• Measured end-point kinematics and string-pulling topography, including cycles, misses, and mouth engagements.

Main Results:

• Reduced string diameter led to significantly longer pull times.
• Mice demonstrated increased pulling cycles, misses, and mouth engagements with thinner strings.
• Changes in pull cycle amplitude and frequency were observed, correlating with increased task difficulty.

Conclusions:

• String diameter influences skilled motor behavior, with smaller diameters increasing task difficulty.
• Movement time increases and compensatory sensorimotor strategies are engaged as task difficulty rises, consistent with Fitts's Law.
• Information-theory principles can quantify the effective use of time in skilled motor tasks.