Abstract
Neural and behavioral evidence of reorganization in the adult human primary visual cortex (V1) has been reported in patients following long-term deprivation (i.e. months to years) due to stroke or Macular Degeneration. By contrast, reorganization following short-term deprivation (i.e. seconds to minutes) is far less clear: neural evidence is absent, behavioral evidence is sparse, and studies combining neural and behavioral evidence have not been reported. Here we provide the first converging neural and behavioral evidence of rapid reorganization in healthy adult V1. Specifically, we patched one eye, thus noninvasively and reversibly depriving the cortical representation of the other eye’s blind spot (BS), and then tested for reorganization using functional magnetic resonance imaging (fMRI) and psychophysics. Within minutes of eye patching, the cortical representation of the BS in V1, which normally responds to stimuli presented inside the BS in the visual field, began responding to stimuli presented outside of the BS, consistent with evidence from patients with long-term visual cortical deprivation. Crucially, these same stimuli were perceived as elongated (i.e. squares were perceived as rectangles) following deprivation. This rapid reorganization was specific to the deprived cortex only, and is too fast to be the result of structural changes (e.g., the growth of new connections), instead implicating the unmasking of preexisting connections as the underlying neural mechanism. These findings constitute the strongest evidence to date that human V1 retains the capacity for change in adulthood, and that such reorganization can occur in just minutes following the loss of normal visual input.