Uncovering atypical gaze patterns in cerebral visual impairment: New insights from an exploratory gaze-based analysis

Abstract

Individuals with cerebral visual impairment (CVI) often struggle with visuospatial processing, particularly in highly cluttered or complex environments. These challenges are commonly assessed through visual search tasks, using global measures such as reaction time (RT), accuracy, and search area. Accordingly, impaired search performance in CVI manifests as longer RTs, lower accuracy, and broader search areas. However, rather than elucidating the underlying mechanism of the impaired search process, these measures decode its outcome. In the present study, we utilized eye-tracking data to compute detailed measures of fixation count and duration, aiming to characterize gaze pattern sequences and determine whether prolonged RTs in CVI stem from slower visual scanning or increased fixation counts. Our reanalysis of two previously published datasets reveals that longer RTs in CVI arise from elevated fixation counts, specifically on distractors, rather than from slower visual scanning. Our findings indicate recurrent disruptions in maintaining gaze on the target, likely reflecting difficulties in sustaining attention on the target, suppressing distractors, and preventing inhibition of return. Together, these findings highlight an inefficient search pattern that is more biased toward distractors than focused on targets. By revealing these underlying mechanisms, gaze-based measures offer a deeper understanding of visuospatial processing deficits in CVI.