Speaker
Description
Visuospatial processing deficits are commonly observed in individuals with cerebral visual impairment (CVI), even in cases where visual acuity and visual field functions are intact. CVI is a brain-based visual disorder associated with the maldevelopment of central visual pathways and structures. However, the neurophysiological basis underlying higher-order perceptual impairments in this condition has not been clearly identified, which in turn poses limits on developing rehabilitative interventions. Using eye-tracking and EEG recordings, we assessed the profile and performance of visual search on a naturalistic virtual reality-based task. Adolescents with CVI and age-matched controls with neurotypical development were instructed to search, locate, and then fixate on a specific target placed among surrounding distractors at two levels of task difficulty. We investigated ocular behaviour (i.e., success rate, reaction time, and gaze error) and neural oscillations, analysing both evoked and induced components of a broadband frequency range (4–55 Hz). Behavioural data showed an overall visual search impairment in CVI participants. Neural oscillations analysis revealed, regardless of task difficulty, markedly reduced evoked theta activity and higher induced gamma response in CVI. Moreover, while in controls, induced alpha activity increased with task difficulty, this modulation was absent in the CVI group, identifying a potential neural correlate of visual search and distractor suppression deficits. We conclude that pervasive impairments of visual search in CVI are associated with substantial alterations across a wide range of neural oscillation frequencies. Alterations were found in both evoked and induced oscillatory components, suggesting the involvement of feedforward and feedback processing.
| If you're submitting a symposium talk, what's the symposium title? | Spazio sensoriale: Esplorando le dimensioni e lo sviluppo della percezione del corpo e dell’ambiente con e senza disabilità sensoriale |
|---|---|
| If you're submitting a symposium, or a talk that is part of a symposium, is this a junior symposium? | No |
