Visual Attention and Perceptual Categorisation

• Main Author: Guest, Duncan
• Published: University of Warwick 2007
• Subjects: 150.724
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490408

Process models of categorisation have been developed to account for the interactions between perceptual processes and decisional processes in categorisation. The formalised relation between perceptual and decisional processes described in the extended generalised context model (K Lamberts, 1995, 1998) has been shown to provide a good account of time course data from categorisation tasks as well as other tasks such as perceptual matching and recognition. In a set of four experiments the assumption in the extended generalised context model that visual attention has a negligible influence on perceptual and decisional processes was examined. Experiment 1 and 2 examined whether visual attention could influence perceptual processing and Experiment 3 and 4 examined whether visual attention could influence both perceptual and decisional processes in categorisation. Contrary to previous findings Experiments 1-4 demonstrated that visual attention can have a large influence on perceptual processing in categorisation. Consistent with previous results it was found that visual attention does not influence decisional processes in categorisation and that there are multiple systems of attention controlling decisional and perceptual processes in categorisation. In Experiment 5 and 6, the extended generalised context model was extended for application to visual search tasks. Experiments 5 and ~ examined whether this new model could account for the time course of similarity effects in visual search. The new model provided a good account of the time course of similarity effects and display size effects. The implications of these findings are discussed in relation to the research on perceptual and decisional processes in categorisation and alternative theories of visual search.