Is delayed foveal feedback critical for extra-foveal perception?

Recent neuroimaging evidence suggests that visual inputs arising beyond the fovea can be 'fed back' to foveal visual cortex to construct a new retinotopic representation. However, whether these representations are critical for extra-foveal perception remains unclear. Using transcranial magnetic stimulation we found that relatively late (350-400 msec) disruption of foveal retinotopic cortex impaired perceptual discrimination of objects in the periphery. These results are consistent with the hypothesis that feedback to the foveal retinotopic cortex is crucial for extra-foveal perception, and provide additional evidence for 'constructive' feedback in human vision. (C) 2012 Elsevier Ltd. All rights reserved.