Eye Tracking and Interhemispheric Interaction in the Distribution of Spatial Attention

Abstract

The patterns of visual attention allocation were investigated in healthy subjects (n = 43) and patients with focal brain lesions (n = 17) using the original method developed for eye tracking in patients while memorizing a series of stimulatory image triplets. Two processes were estimated: delayed reproduction and recognition of stimuli in a series of consecutive visually similar distractors. In healthy subjects both processes correlated to a great extent (r = 0.6; p = 0.00001). The most significant disorders of voluntary verbal reproduction were observed when the left hemisphere of the brain was affected. The overall effectiveness of recognition in the case of brain damage decreased without significant dependence on the lateralization of the focus. Some correlation was observed between realized and remembered information and the patterns of visual fixations (concentrated on the semantic parts of the image or chaotically distributed in the space of stimulus exposure). Ineffective patterns of visual fixation in patients were more often observed in the area contralateral to the lesion. These contralateral stimuli were reproduced and recognized less efficiently in comparison with the central and ipsilateral images. Complete ignoring of the contralateral image in the triplet was observed both in the absence of visual fixation and in combination with the diffuse pattern.