MICROSACCADIC RESPONSE DURING INHIBITION OF RETURN IN A TARGET-TARGET PARADIGM

This study examined the relationship between inhibition of return (IOR) in covert orienting and microsaccade statistics. Unlike a previous study [Galfano, G., Betta, E., & Turatto, M. (2004)], IOR was assessed by means of a target–target paradigm, and microsaccade dynamics were monitored as a function of both the Wrst and the second visual event. In line with what has been reported with a cue-target paradigm, a signiWcant directional modulation was observed opposite to the Wrst visual event. Because participants were to respond to any stimulus, this rules out the possibility that the modulation resulted from a generic motor inhibition, showing instead that it is peculiarly coupled to the oculomotor system. Importantly, after the second visual event, a diVerent response was observed in microsaccade orientation, whose direction critically depended of whether the second visual event appeared at the same location as the Wrst visual event. The results are consistent with the notion that IOR is composed of both attentional and oculomotor components, and challenge the view that covert orienting paradigms engage the attentional component in isolation.