Abstract
The dead zone of attention (DZA) was previously found in change blindness research. DZA is a region closely surrounding the centre of interest (CI) where change blindness manifestations are exaggerated. Utochkin (2011) hypothesized that DZA partially consequences from a biologically predisposed search strategy that causes attention to avoid regions near the CI's as they appear to be uninformative. Here we attempted to test this hypothesis. We tried to influence the manifestations of DZA by manipulating this strategy. In order to test the hypothesis, we conducted three similar experiments consisting of two serial blocks. In Block I, observers were exposed to 12 flickering images inducing change blindness. Each image included a change within CI. Observers easily detected changes and subsequently couldn't ignore them. In Block II, images repeated and one marginal change (either near, or far from CI) was added to each previously found CI change. In Experiment 1, Block II was preceded by explicit informing observers about the essence of DZA phenomenon. In Experiment 2, there was no such information but all "near" and "far" changes were blocked to encourage implicit preference of corresponding locations. In Experiment 3, observers received both preliminary information and blocked trials. Results of all experiments were then compared to those reported by Utochkin (2011) in his experiment with the same stimulation but without informing observers and blocking trials. It was found that manipulating trials sequence reduced the search time across an image in Experiment 2. Manipulating information had no effect on search time around an image indicating relative constancy of global strategy. All manipulations reduced the number of missed changes within DZA suggesting local strategic regulation of attentional allocation around CI's. The effect was stronger in Experiments 1 and 3 than in Experiment 2 suggesting different contributions of explicit and implicit strategies.
Meeting abstract presented at VSS 2013