Detection of moving and stationary gratings in the absence of striate cortex

A 30-yr-old woman whose left occipital lobe had been removed because of an arteriovenous malformation was tested for her ability to detect stationary flashing and moving luminance gratings in the right (blind) visual field. With stationary gratings the performance remained close to chance level, but with moving gratings her performance on a 2AFC task rose to an average of close to 68% during 1200 trials. Signals mediated via midbrain structures might be the basis for the above-chance detection of movement.