Receptive-field-like functions inferred from large-area psychophysical measurements

By means of quasi-sinusoidal, circular stimulus patterns, frequency modulated to correct for the radial component of retinal inhomogeneity, we attempt to make all eccentricities within a 16-deg field contribute equally to the threshold response. Wide-field contrast-sensitivity data obtained with these frequency-modulated stimuli are modeled using a canonical form of local contrast sensitivity function (CSF), scaled linearly with eccentricity. Calculating Fourier transforms of the constant-velocity, local CSF, we obtain line-spread and point-spread functions that can also be interpreted as receptive-field responses at various eccentricities. These results are compared to other data on local spatial processing in the retina.