Phenomenology and Neurophysiological Mechanisms of Visual Hallucinations in Visually Impaired Patients

RESEARCH QUESTION: are hallucinations of retinal origin explained by predictive coding accounts based on top down interactions between parietal imagery networks and visual areas or can they instead be explained by bottom up models based on deafferentation?

Neuroimaging protocol: Resting state & stimulus related fMRI and with periodic geometric figures which often elicit or mimick hallucinatory patterns.

EXPECTED RESULTS: We expect to discriminate between predictive coding models based on top down interactions between dorsal attention and parietal imagery networks and visual areas and bottom up models based on deafferentation.