Spatial stimulus generalization as a function of white noise and activation level.

Judgments of the numerousness of patterns of dots vary with the size of the background on which the dots are presented The direction of this judgmental illusion depends upon the experimental correlation between background size and actual number of dots When the correlation is positive, judged numerousness varies inversely with background size, however, when the correlation is negative, the illusion is reversed The subjective correlations estimated from an expectancy-contrast model were found to be a monotonic function of the 7 actual correlations used in 2 experiments These results replicate and extend previous findings for the stze-numerosity illusion