Saccadic eye movements rapidly displace the image of the world that is projected onto the retinas. In anticipation of each saccade, many neurons in the visual system shift their receptive fields. This presaccadic change in visual sensitivity, known as remapping, was first documented in the parietal cortex and has been studied in many other brain regions. Remapping requires information about upcoming saccades via corollary discharge. Analyses of neurons in a corollary discharge pathway that targets the frontal eye field (FEF) suggest that remapping may be assembled in the FEF's local microcircuitry. Complementary data from reversible inactivation, neural recording, and modeling studies provide evidence that remapping contributes to transsaccadic continuity of action and perception. Multiple forms of remapping have been reported in the FEF and other brain areas, however, and questions remain about the reasons for these differences. In this review of recent progress, we identify three hypotheses that may help to guide further investigations into the structure and function of circuits for remapping. eye movements; perception; remapping; saccades; vision WE PERCEIVE THE ENVIRONMENT as continuous, but neurons in the brain take samples that are constrained in space and time. Specific ranges of stimuli drive a neuron to produce action potentials. From the 1960s through the 1970s, it was essentially dogma that the stimulus-spike relationship of a sensory neuron revealed its "receptive field," the portion of the world to which a sensory neuron responds. Response gain could be modulated by internal factors such as attention or external factors such as contrast, but the structure of receptive fields seemed immutable and their function, to report what is out there, seemed passive. In the case of the visual system, neurons were assumed to have static receptive fields relative to the fovea.Evidence for exceptions to this rule emerged in the 1980s, and the dogma was overturned in the 1990s, when behaving animal preparations allowed for studies in which eye movements were incorporated as factors in experimental design. It became clear that around the time of saccades the spatial structure of receptive fields can change. Here we summarize the advances in our understanding of labile receptive field location with a focus on circuit-level studies from the past 20 years. Progress has been made in elucidating the mechanisms of receptive field remapping both at the macrocircuit level (pathways between brain areas) and the microcircuit level (processing within brain areas). Recent physiological and modeling experiments have leveraged this circuit information to explore the visuomotor and perceptual functions of remapping. Taken together, a new picture of the genesis and role of presaccadic remapping emerges, yielding testable hypotheses for future work.
Presaccadic Visual RemappingThe first hint that visual receptive fields can be spatially dynamic was reported by Mays and Sparks (1980) in a study of neurons located in the intermediate...