Transient and sustained effects of an auditory accessory stimulus in a visual go/no go task.

The present study examined the facilitation effects of an auditory accessory stimulus that was irrelevant to a visual reaction time (RT) task as a function of stimulus onset asynchrony between the accessory stimulus and the visual target stimulus. Results of the present experiment showed that the auditory accessory stimulus caused two variations of RT, short-term and long-term, that were distinguished on the basis of stimulus onset asynchrony. This finding suggested that effects of an accessory stimulus consisted of two qualitatively different facilitations. The Transient Facilitation appeared instantly after the onset of the accessory stimulus and then soon decayed, and the Sustained Facilitation increased and decreased more gradually than the former.