Receptive-field sizes during remapping and uniform transsaccadic updating across the visual space.

Forward receptive-field (RF) remapping, a mechanism for transsaccadic updating of retinal positions and perceptual stability, transiently changes cells' eccentricities and thus could also change their RF sizes, yet few studies examined RF sizes during remapping. A related issue is how the mechanism ensures the desired uniform updating across the visual space - a subtraction of the saccade vector from stimuli's retinal positions wherever they appear - given highly nonuniform RF sizes and cortical magnification over eccentricities. We analyzed our recent circuit model for remapping/updating after incorporating eccentricity-dependent RF sizes and found that when the corollary-discharge-gated connections achieve uniform updating in the visual space, the model predicts no change to cells' RF sizes despite their receiving inputs from other cells with different RF sizes. In contrast, if the updating were uniform in the cortical space but not visual space, cells' RF sizes would change during remapping. We analyzed the data from the lateral intraparietal area and frontal eye fields and found that remapping magnitudes are similar for cells of different eccentricities. We then confirmed the prediction that RF sizes did not change significantly during remapping. These results reveal a circuit mechanism for uniform updating and perceptual stability across the entire visual field.