Single additive mechanism predicts lateral interactions effects-computational model.

The mechanism underlying the lateral interactions (LI) phenomenon is still an enigma. Over the years, several groups have tried to explain the phenomenon and suggested models to predict its psychophysical results. Most of these models comprise both inhibitory and facilitatory mechanisms for describing the LI phenomenon. Their studies' assumption that a significant inhibition mechanism exists is based on the classical interpretation of the threshold elevation perceived in psychophysical experiments. In this work, we suggest a different interpretation of the threshold elevation obtained experimentally. Our model proposes and demonstrates how a facilitatory additive mechanism can solely predict both the facilitation and "inhibition" aspects of the phenomenon, without the need for an additional inhibitory mechanism, at least for the two flankers' configurations. Though the model is simple it succeeds to predict the LI effect under a large variety of stimuli configurations and parameters. The model is in agreement with both classical and recent psychophysical and neurophysiological results. We suggest that the LI mechanism plays a role in creating an educated guess to form a continuation of gratings and textures based on the surrounding visual stimuli.