ABSTRACT
We have already seen that there is overwhelming evidence that the brain computes multiple sources of information over multiple channels. In preceding chapters we have reviewed studies that provide evidence for the independence of colour, identity, and location. We have considered the way in which attention might move over the visual field and noted that attention is affected fected by perceptual grouping and that objects rather than locations can be attended to. What we have not yet considered is how the separate codes are combined into objects. Clearly, this is crucial. We do not inhabit a world of fragmented colours, shapes and meanings, but interact with meaningful objects which are segregated such that the correct attributes of individual objects are combined. In addition to the question of how attributes are combined, there is another question concerning visual search: how does attention find a designated target in a cluttered visual field? It is to these questions that we now turn.
