THE EFFECTS OF LEFT VS. RIGHT EAR STIMULATION ON HUMAN STARTLE REFLEX MODULATION

Abstract

It has been reported previously that modulatory effects of pleasant and unpleasant slides on the human acoustic reflex are observed only if startle probes are presented to the left ear or with binaural presentation. The present study examined the effects of the left and the right ear stimulation on modulated startle reflex (as indexed by eyeblink component, measured at the right eye) employing short (2-min) film-clips to elicit emotions. Sixteen right-handed subjects served as volunteers. The experiment included two consecutive sessions, on a single occasion. The acoustic stimuli were presented monaurally to one of the ears in each session, counterbalanced across order. The laterality phenomenon in startle modulation previously observed with affect-toned slides was not confirmed in this experiment. The probable discrepancy will be discussed methodologically.