Horizontal rhythmical eye movements consistently diminish the arousal provoked by auditory stimuli

Objectives. Theoretical models implicating the orienting reflex as an explanatory mechanism in the eye-movement desensitization and reprocessing (EMDR) treatment protocol are contrasted and tested empirically. We also test whether EMDR effects are due to a distraction effect. Design. A repeated measure design is used in two experiments. The first experiment employed two independent variables, eye condition (moving vs. stationary) and tone (a pseudo-randomized series of low and high intensity tones). In Expt 2, eye condition was replaced by attentional demand conditions (low or high). In both cases, electrodermal responses served as the dependent variable. Method. Participants were recruited from the Psychology Department at Cardiff University. In Expt 1, participants were required to either pursue a moving stimulus following auditory challenge or engage in an eyes-stationary task. In Expt 2, the task following auditory challenge required participants to identify specific items from letter strings in low and high attentional demand conditions. Results. Lower levels of electrodermal arousal were identified in tasks eliciting eye movements, compared to no eye movements. This effect was not due to the attentional requirements of the task. Conclusions. Eye movements following auditory challenge result in an effect of psychophysiological de-arousal. This supports the reassurance reflex model of EMDR proposed by MacCulloch and Feldman (1996).