Abstract
Monkey feature conjunction search data [1] indicate that colour is more important than form in driving the scan path. Target object-based attentional effects appear to develop over a time course beginning later than spatial attention in area V4 [2,3] and target-coloured features are enhanced in parallel across the visual scene in this area [4]. Parietal area LIP encodes colour information where this is behaviourally relevant [6] and may act as a saliency map [7] that determines positions of potential targets during visual search. This computational model shows that object-based attention in V4 is able to provide featural information to LIP necessary for it to become an integrator of information used to guide the scan path towards behaviourally relevant features. The model suggests that spatial inhibition of return in the scan path may be implemented within parietal cortex [8] partly as a result of a scene-based “novelty” bias, possibly supplied by frontal regions [9]. Resultant active vision scan paths detect target-coloured stimuli across the scene, as found in [1]. Also, the area within which object-based attention develops and a target can be identified [10] may be constrained by the initial spatial focus of attention.
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