Voluntary stimulus production enhances deviance processing in the brain.Int J Psychophysiol. 2006 Jan; 59(1):15-21.IJ
Humans often get information by voluntary action. However, little is known about how stimulus processing is modulated by self-production of stimuli. In the present study, event-related brain potentials were recorded from 16 student volunteers performing an auditory three-stimulus oddball task in two conditions. In the self condition, the stimuli were triggered by participants' voluntary button presses. In the auto condition, the same stimuli were presented automatically by a computer with the same interstimulus intervals as those in the self condition. Perceptually deviant nontarget stimuli elicited a larger P3 and a larger subsequent positivity in the self condition than in the auto condition, whereas low-deviant target stimuli elicited a P3 with equally high amplitude in both conditions. The findings suggest that voluntary stimulus production enhances orienting of attention (reflected in the P3a component) and subsequent memory updating (reflected in the P3b component) for deviant stimuli, but does not affect the response to task-relevant stimuli. Voluntary action may activate the perceptual representation of its most frequent outcomes and this anticipatory activation may make deviant stimuli more salient in the context.