Voluntary and involuntary dynamics of perception-action processing

Abstract

The current study investigated the role of both involuntary motor activations and voluntary stimulus-response (S-R) mappings (i.e., the subjects voluntarily learned altered S-R mappings) in perception-action processing. Involuntary motor activations were triggered by graspable objects, and voluntary S-R mappings were manipulated by adjusting the proportion of compatible trials (PC; 80%, 50%, and 20%) for which the potential motor properties of objects were compatible with the responses. The results showed large positive compatible effects when regular S-R associations were strong (80% PC) but negative compatible effects when reversed S-R associations were established (20% PC). Moreover, the size and developing speed of the compatible effects were larger with 80% PC than with 20% PC. The findings suggest that the direction, magnitude, and developing speed of object affordances are codriven by both involuntary motor activations and voluntary S-R mappings. Specifically, when these two factors are consistent with each other, motor activations will be amplified, and the magnitude and developing speed of affordance effects will thus be increased. However, when they are inconsistent, they will compete with each other, and affordance effects will be decreased or reversed with an increasing proportion of trials within the S-R mappings. The codriven model of perception-action processes reflects the optimization of our cognitive control system for processing a complicated environment.