Spatial frequency range in the detection process—2. Wide bars and sharp edge

Abstract

The effect upon the detectability of broad bars and a sharp edge of ideal low- and high-pass filters was investigated. The results indicate that, for optimum detection of the stimulus, spatial frequency components up to about 5 c deg-1 need to be transmitted. Two models (a multi-channel model, incorporating probability summation across spatial frequency, and a Grating Sensitivity Curve model) were used in attempting to fit the results. The multi-channel model provided a more realistic fit, but both models ultimately failed because of non-linearity in the summation of responses to frequency components.