Duration of Alpha Suppression Increases with Angle in a Mental Rotation Task

摘要

Magnetic and electric recordings of average power within the restricted alphaband (10-12 Hz) were made over the parietal and occipital -areas of the human scalp while subjects were engaged in the mental imagery task of comparing an object with one previously seen but rotated and perhaps also mirror reflected. Alpha power was found to be suppressed while the subjects were engaged in the comparison, and the duration of suppression increased with the minimum rotation angle to achieve a match. This is additional evidence that visual cortex is engaged in the process of mental imagery. Moreover, for large rotation angles, where the task is markedly more difficult, a shift in the spatial pattern of suppression indicates that the left parietal area of the cortex becomes involved....Brain waves, Alpha waves.