Dimension-specific effects of endogenous and exogenous spatial cueing indication for integration of spatial and feature-based attention /

The experiments in this thesis were designed to examine the consequences of endogenous and exogenous spatial cueing in a dual-task set-up. The first experiments, presented in Chapters 2 and 3, explored whether spatial attention generalises across dimensions in the same location. Chapters 4, 5, and 6 contain a second series of experiments using exogenous cues, in which cue properties were manipulated. A dual-task set-up was used in all studies in this thesis, with a display of four random dot kinematograms containing motion and colour features. In order to examine whether endogenous attention may be spatially oriented to only one feature dimension, a central cue was presented that was 70% valid for the location of only one task. Both tasks showed validity effects, but the task for which the cue was informative showed larger attentional modulation. This suggests that spatial attention is not a single 'spotlight' but can be biased in favour of expected features. There was also asymmetry in the tasks, whereby the validity effect was modulated for motion, but comparable for colour regardless of the task for which the cue was informative. This asymmetry was also evident when using uninformative exogenous cues preceding the same tasks. Peripheral luminance and colour cues affected the validity effects for the motion and colour tasks differently, suggesting that the relationship between cue properties and proceeding stimuli modulates attentional effects. The size of a frame cue leads to different attentional effects on tasks of different sizes. These experiments make a considerable contribution to the spatial attention literature, by showing that spatial attention may be biased either by cue properties or cue information, suggesting that spatial attention and feature-based attention may interact. They also provide further evidence that motion is better represented than colour in visual attention.EThOS - Electronic Theses Online ServiceGBUnited Kingdo