Interactions between perception and action in a reaction task with overlapping S-R assignments

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human-Computer Interaction

Background:

• Investigating the intricate relationship between sensory perception and motor action is crucial for understanding human behavior.
• Previous research has explored stimulus-response (S-R) associations, but the impact of temporally overlapping, functionally unrelated stimuli and responses remains less understood.

Purpose of the Study:

• To examine the influence of perceived motion on executed movements when stimuli and responses are not explicitly linked.
• To determine if a contrast effect exists between perception and action, and explore its directionality and robustness.

Main Methods:

• Participants performed movements on a graphic tablet while observing visual motion stimuli on a screen.
• A novel experimental paradigm was employed where motion on trial n-1 guided movement on trial n, and motion on trial n guided movement on trial n+1.
• Four experiments systematically varied stimulus-response mapping, motion presentation, and temporal intervals.

Main Results:

• A significant contrast effect was observed: viewing small motions enhanced movement size, while viewing large motions decreased it.
• This contrast effect was consistent regardless of motion presentation modality or the timing between motion and movement.
• The effect was also demonstrated in the reverse direction, from action to perception.

Conclusions:

• A contrast effect significantly modulates the perception-action relationship, even when stimuli and responses are functionally independent.
• This phenomenon is proposed to result from a selective code modification mechanism that enhances the distinctiveness of overlapping perceptual and motor codes.
• Findings suggest a shared representational domain for perception and action.