Abstract
Previous evidence of attention deficits in individuals with amblyopia (Popple & Levi, 2008; Secen et al., 2011) has relied on studies that were conducted purely in the visual domain. However, it is unknown whether amblyopes are also impaired when visual attention is cued within the auditory domain. To test this, we recorded event-related potentials (ERPs) to examine differences in attentional orienting to an auditory cue when observing with an amblyopic (AE) vs. dominant eye (DE). While fixating, a brief auditory cue prompted observers to attend to one of two locations in the left and right visual field, where stimuli were later bilaterally presented following a 800ms cue-target-interval. The target stimulus was a tilted Gabor patch that appeared on the cued side in 5% of the trials, and on the uncued side in another 5%. In all other cases, stimuli were horizontally-oriented Gabor patches. Observers were instructed to respond via key press only when the target stimulus appeared in the cued location. Contrast and orientation of targets were adjusted prior to recordings such that each individual could achieve 75-90% accuracy on the task while viewing monocularly with each eye. To isolate cued-attention effects, ERPs recorded for contralaterally-cued events were subtracted from ipsilaterally-cued events for the AE and DE. Our preliminary results indicate that during the cue-target-interval, anterior electrodes (F7, F5, F3) showed greater modulation to the auditory cue in the DE in comparison to the AE, with two contralateral positivity peaks at 100-180ms and 200-450ms. The observed differences in event-related lateralization effects provide initial evidence of decreased attentional orienting when viewing with the AE, even when driven by cues in the auditory domain. As directing attention to a visual stimulus can boost the speed and accuracy of its processing, increasing this orienting response may help improve other aspects of amblyopic viewing.
Meeting abstract presented at VSS 2013