Interhemispheric transfer time of audiomotor information

Abstract

Since the crossed–uncrossed difference technique was first described by Poffenberger [Arch. Psychol. 23, 1–73 (1912)], it has been used numerous times to measure interhemispheric transfer time (IHTT) of visuomotor information via the commissural system [see Marzi, Bisiacchi, and Nicoletti, Neuropsychologia 29, 1163–1177 (1991), for a review]. In spite of its widespread use by vision researchers, this technique has never been used to measure IHTT of audiomotor information. In the present study, audiologically normal dextral listeners made a simple reaction time response to brief spatialized bursts of broadband noise presented dichotically over insert earphones. For each listener, one block of 120 trials was completed with each hand. Half of the stimuli in each of the response conditions (right/left hand) were presented in the right hemifield, the remaining half in the left hemifield. Crossed–uncrossed differences were computed for each listener. Results will be discussed in terms of IHTT for audiomotor information and the possibility of cerebral lateralization of auditory localization processing.