The involvement of cognitive processing in a perceptual-motor process examined with EEG time-frequency analysis.

OBJECTIVE

For motor activities, visual information is crucial for organizing a movement with respect to a given situation. The present study investigates how cognitive information processing is associated with this visuomotor process.

METHODS

Brain dynamics in executing two perceptual-motor tasks were examined in terms of event-related synchronization (ERS) and event-related desynchronization (ERD) of EEG. Those tasks were (1) reaching toward and grasping a visual object with a pinch grip, and (2) matching the pinch grip size with respect to the perceived object size.

RESULTS

According to the aperture size in the task execution, both the tasks were affected by the perceived object size inducing the Ebbinghaus illusion. The alpha-ERD patterns were associated with the movement execution and appeared to be identical in both the tasks, whilst the gamma-ERS appeared only for the grasping motion.

CONCLUSIONS

These results suggest that cognitive processing was involved not only in the matching task but also in the grasping task. These ERD/ERS patterns are thought to reflect the similarity and difference in the perceptual-motor processes between the two tasks.

SIGNIFICANCE

The analysis of ERD/ERS can provide insight on the qualitative feature in a visuomotor process associated with the involvement of cognitive processing.