AUDITORY FEEDBACK CONTROL OF TONIC ELECTRODERMAL ACTIVITY

Abstract

Sixteen dextral males and females were presented auditory feedback, the frequency of which was inversely proportional to the sum of the skin resistance levels (SRLs) of the two hands. The feedback was presented in a two-period change-over design. Seven subjects received 10 minutes of feedback to the left ear first, followed by 10 minutes of feedback to the right ear; the remaining nine subjects received right ear feedback first, followed by feedback to the left ear. In all subjects, the ear not receiving the feedback was presented with a white noise masking stimulus. Subjects were instructed to decrease the frequency of the feedback, and thus increase their SRL, by relaxing and focusing their attention on the feedback.;Analyses of the data failed to demonstrate a significant difference in the increase in SRL (in either hand) between left and right ear presentations of the feedback. However, there was found a vigorous increase in SRL in the right hand following feedback to either ear in either presentation order. This significant increase in right hand SRL was associated with small magnitude decreases or increases in SRL in the left hand. Since the production of increases in SRL in the hands is effected through the inhibitory activity of the contralateral hemisphere, it appears that it is the left hemisphere which is active during the acquisition of electrodermal inhibitory control. It is concluded that the left hemisphere is functionally dominant with regard to the process of acquisition of electrodermal inhibitory control via the use of auditory feedback. It is suggested that the pre-eminence of the left hemisphere in this process may be attributable to the dominance of the left hemisphere in dextrals in the processing to auditory information in general, due to the dominance of the left hemisphere in language-related functioning. Thus, the notion of left hemisphere functional dominance in the acquisition of inhibitory control of the SRL is only applicable at this point to dextrals receiving auditory feedback.