The effect of asymLSF on face discrimination.

<p>Each row shows the psychometric functions from one of the three naïve observers. The fraction of “female face” responses is plotted as a function of the proportion of female face in the combined images. The black psychometric function is for the symHSF-only condition plotted here for comparison. The red, green, blue and magenta psychometric functions represent different illumination directions as indicted in the legend. In the female-face asymLSF condition (left column), the psychometric functions shifted gradually to the left as illumination angle increased. Conversely, in the male-face asymLSF condition (right column), the psychometric functions shifted dramatically to the right.