Counting on the mental number line to make a move: sensorimotor ('pen') control and numerical processing

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human-Computer Interaction

Background:

• Mathematics often involves writing implements, raising questions about the link between numerical processing and sensorimotor control.
• The mental number line (MNL) is a cognitive tool influenced by cultural spatial organization, affecting mathematical task performance.
• The MNL effect demonstrates that culturally standard number line orientations enhance performance.

Purpose of the Study:

• To investigate the relationship between numerical processing and sensorimotor control using a stylus-based task.
• To examine how cognitive load, specifically reversing the mental number line (MNL), affects both response selection and movement execution.
• To determine if individual motor abilities influence performance on numerical tasks with varying cognitive demands.

Main Methods:

• Participants moved a stylus to cross lines at locations indicated by symbolic numbers (1-9).
• Number color cued whether the line orientation was 'normal' (left-right) or 'reversed' (right-left).
• Experiments involved consistent blocks of trials and a mixed block with random line direction variations, measuring response time and movement duration.

Main Results:

• The MNL effect was confirmed as robust.
• Cognitive load from reversing the MNL significantly impacted movement execution duration in mixed trials.
• Individual motor abilities predicted performance in difficult mixed trials but not in easier, consistent blocks.

Conclusions:

• Numerical processing is not independent of motor capabilities.
• Cognitive load associated with mental number line manipulation has tangible effects on motor control.
• Findings have implications for understanding the interplay between numerical cognition and physical action.