Detection of compound spatial patterns: further evidence for different channel interactions.
It is shown that contrast interrelation functions for small compound gratings and for small compound edge-type patterns have different shapes: the former are lozenges, the latter ellipses in the normalised contrast space. These findings can be described by a simple p-norm model, comprising one channel which is most sensitive to the first pattern, another channel which is most sensitive to the second pattern and a non-linear summation of the channel outputs. Since the value of the summation exponent p is constant within but varies between pattern classes, an interpretation of the model parameters is limited to pattern class. Channel models based on the p-norm are discussed, taking into account the interpretation of the first derivative of the contrast interrelation function and the summation exponent, p.
Meinhardt
G
G
FB08, Westfälische Wilhelms-Universität, Münster, Germany.
D003198:Computer Simulation; D015350:Contrast Sensitivity / Q000502:physiology*; D003626:Data Display; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D008432:Mathematical Computing; D008959:Models, Neurological; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D012680:Sensitivity and Specificity; D012684:Sensory Thresholds / Q000502:physiology*