Abstract
Healthy individuals direct more attention to the left side, a phenomena known as pseudoneglect. Although visual attentional asymmetries are subtle, they have the ability to influence real-world navigational behaviour. Multisensory targets preferentially attract attention and are detected more quickly, suggesting visual attentional biases could be improved by engaging cross-modal processing. The current study examined whether left and right auditory distractors differentially impact attentional asymmetries. Participants (N=36) completed a standard perceptual landmark task to measure baseline pseudoneglect. In a second landmark task, auditory distractors were presented in conjunction with line stimuli (250ms) and participants judged which portion of the line was longer. Two blocks of trials were completed: one where 80% of distractors were presented to the left ear and one wherein 80% were presented to the right. One participant was excluded for low accuracy. Significant pseudoneglect was observed at baseline. Change scores were computed by subtracting baseline scores from bias scores for auditory distractor trials. A significant interaction between ear (left, right) and distractor frequency (tonic, phasic) occurred [F(1, 34) = 12.932, p = .001, ηp2 = .937]. Pseudoneglect biases were significantly more rightward for right ear distractors, compared to left ear distractors. In the presence of left ear auditory distractors, attentional asymmetries decreased slightly, but were still leftward. For right ear distractors, attention was directed to the right of centre. Phasic right ear distractors elicited significant rightward visuospatial biases, whereas mean asymmetries were rightward for tonic right ear distractors, but not significantly so. The salience of infrequent right ear distractors led attention to be more strongly drawn toward the right side. Although participants were instructed to ignore auditory distractors, overall asymmetries were decreased by their presence. As expected, engaging cross-modal processing improved attentional asymmetries; however, infrequent distractors appear to be highly salient, and therefore capable of creating rightward asymmetries.
Meeting abstract presented at VSS 2016