title: Neural correlates of visual extinction or awareness in a series of patients with right temporoparietal damage.
abstract: Patients with visual extinction following right-hemisphere damage can typically detect left visual field stimulation when it is presented in isolation, but tend to miss this when it is paired with competing concurrent right visual stimulation. Some single-case studies have provided preliminary evidence that right visual cortex may show residual activation for contralesional, extinguished visual stimuli. Here we go beyond prior work by using individual retinotopic mapping and online eye-tracking during fMRI to study activity in stimulus-responsive retinotopic visual cortex for a case series of four extinction patients. We found consistent activation of retinotopic right visual cortex for bilateral visual stimulation that resulted in left extinction. This residual unconscious activation included areas V1 to V3 and was not due to inadvertent eye movements. We also provide further evidence for the emerging view that awareness may require activity of frontal and parietal regions well beyond visual cortex.
authors.affiliation: a Medical Research Council Cognition and Brain Sciences Unit , Cambridge , UK.
authors.forename: Margarita
authors.initials: M
authors.lastname: Sarri
authors.forename: Christian C
authors.initials: CC
authors.lastname: Ruff
authors.forename: Geraint
authors.initials: G
authors.lastname: Rees
authors.forename: Jon
authors.initials: J
authors.lastname: Driver