Concurrent deployment of visual attention and response selection bottleneck in a dual-task: Electrophysiological and behavioural evidence.
The binding problem arises when visual features (colour, orientation), said to be coded in independent brain modules, are to be integrated into unitary percepts. I argue that binding is an ill-posed problem, because those modules are now known to code jointly for multiple features, rendering the feature-binding issue moot. A hierarchical reentrant system explains the emergence of coherent visual objects from primitive features. An initial feed-forward sweep activates many high-level perceptual hypotheses, which descend to lower levels, where they correlate themselves with the ongoing activity. Low correlations are discarded, whereas the hypothesis that yields the highest correlation is confirmed and leads to conscious awareness. In this system, there is no separate binding process that actively assigns features to objects.