The function of dynamic grouping in vision

In this review we consider the logic and the evidence relating to the issue of dynamic grouping in human vision. Dynamic grouping is required when the visual system is creating novel descriptions, either because it is dealing with novel stimuli or it is providing information for novel purposes. In such cases, dynamic grouping provides a mechanism for discovering regularities in the data. We consider a number of examples, including grouping of visual information into surface descriptions and contour descriptions. The main issues that arise concern the configurability of the process and the effects of the propagation of local configurations. We then turn to the complex issue of visual search. Visual search allows the experimenter to establish something of the nature of pre-attentive visual descriptions and how these differ from attentive descriptions. We describe the basic results of visual search experiments in terms of the type of grouping involved. Finally, we consider the hypothesis that dynamic grouping is signalled by neuronal synchrony.