Endogeneous and Exogenous Control of Visual Selection: A Review of the Literature
INSTITUTE FOR PERCEPTION RVO-TNO SOESTERBERG (NETHERLANDS)
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Among the most fundamental issues of visual attention research is the extent to which visual selection is controlled by properties of the stimulus or by the intentions, goals and beliefs of the observer. Before selective attention operates, preattentive processes perform some basic analyses segmenting the visual field into functional perceptual units. The crucial question is whether the allocation of attention to these perceptual units is under the endogenous control of the observer intentions, goals, beliefs or under the exogenous control of stimulation. This report discusses evidence regarding the endogenous and exogenous control of attention in tasks in which subjects search for a particular basic feature e.g., search for a unique color, shape, brightness. The present review suggests that selectivity in these type of search tasks is dependent on the relative saliency of the stimulus attributes. It is concluded that the visual system automatically calculates differences in basic features e.g., difference in shape, color, brightness and that visual information occupying the position of the highest saliency across stimulus dimensions is exogenously passed on to the central representation that is responsible for further stimulus analysis. Alternative explanations of the present findings and tentative speculations resulting from the present approach are discussed.
- Anatomy and Physiology
- Human Factors Engineering and Man Machine Systems