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Zhaoping Li
Department of Psychology, University College London


Wednesday 19 October 2005



Seminar Room B10 (Basement)

Alexandra House, 17 Queen Square, London, WC1N 3AR



A single stage V1 process, not a combination of separate feature maps, creates a bottom up visual saliency map for attentional control --- psychophysical evidences


Highly salient visual locations, e.g., a red item among green ones, attract attention.  The standard view assumes that visual inputs are processed by separate feature maps such as red and green maps, each for a feature value in a few basic dimensions like colour and orientation, which are then summed to a spatial map of bottom-up saliencies or attractions to attention.  We show, using psychophysical experiments on visual search and segmentation, that simple combinations of the feature maps cannot explain the saliency.  Instead, a single stage computation by the primary visual cortex  (V1) is adequate to explain the data.