Effects of distractors on the perception of right angles

Psychophysiological experiments were performed in which imaginary right angles formed by three spots of light were supplemented by distracting line segments. The subjects' task was to restore the orthogonality disturbed by the distractors. Subjects' errors were assessed in relation to the distance between the basal spots and the distractors. The results led to the suggestion that there are specific lateral interaction processes involving local averaging of information on the positions of stimulus components. Quantitative evaluation of the parameters of this interaction was addressed using a simplified mathematical model constructed on the basis of the concept of displacements of the centers of gravity resulting from summation of the corresponding excitation patterns in the neural networks of the visual system. Good consistency between theoretical and experimental data was obtained.