EXTRACTION OF PERCEPTUALLY SALIENT CONTOURS BY STRIATE CORTICAL NETWORKS

We present a cortical-based model for computing the perceptual salienc e of contours embedded in noisy images, It has been suggested that hor izontal intra-cortical connections in primary visual cortex may modula te contrast detection thresholds and pre-attentive ''pop-out'', In our model, horizontal connections mediate context-dependent facilitatory and inhibitory interactions among oriented cells, Strongly facilitated cells undergo temporal synchronization; and perceptual salience is de termined by the level of synchronized activity. The model accounts for a range of reported psychophysical and physiological effects of conto ur salience. In particular, the model proposes that intrinsic properti es of synchronization account for the increased salience of smooth, cl osed contours. Application of the model to real images is demonstrated , (C) 1998 Elsevier Science Ltd, All rights reserved.