Abstract
Past studies have found specialized bimodal neurons, which integrate visual and tactile information in the space near the hand (Graziano & Goss, 1993). More recently, researchers demonstrated that these bimodal neurons influence early perceptual processes (Cosman & Vecera, 2010) and attentional prioritization of space (Reed et al., 2006). However, neither of these two studies examined how bimodal neurons interact with the saliency of the stimuli in the display. To answer this question, we investigated salience-based attentional capture by an irrelevant color singleton (Theeuwes, 1992). Participants searched for a shape singleton with an irrelevant color singleton present on half the trials. In addition, participants held their left hand near the display on half the trials and they held their right hand near the display on the other half. Our results confirmed past findings by showing, in distracter absent trials, faster reaction times when the target was near the hand than when the target was far from the hand. In addition, we found distracters near the hand captured attention significantly more than distracters far from the hand. Importantly, hand position affected capture by a color singleton more than hand position facilitated attention to the target shape singleton. Also, when a distracter was present in the display, response times to a target near the hand were no different from response times to a target far from the hand. Our results suggest that the attentional effects of hand position interact with the saliency of the items in the display.