| Selective attention plays a key role in our interactions with the visual environment, allowing us to choose the information we seek from the vast amount of information available to us at any single point in time. Attention is an intensively studied topic, but is often approached as reflecting a fixed, static system. The research in this thesis, in contrast, demonstrates the rapid influence of learning and memory on even the most reflexive aspects of attention, such as orienting to salient events. The results show that seemingly 'automatic' aspects of attention are in fact subject to rapid learning and plasticity. The research demonstrates the existence of a primitive learning mechanism for the deployment of transient attention that is not under volitional control, showing that these seemingly reflexive orienting mechanisms are, in fact, capable of learning. The results run counter to the view that attention is summoned automatically and indiscriminately to abruptly appearing stimuli.; Firstly, the results show that when peripheral cues indicate the location of an upcoming target, attentional allocation can be rapidly modulated through pairings of a particular cue feature with the location of the subsequent target. Importantly, this learning is object-based rather than space-based, arising irrespective of the absolute location of cue and target, and is not under top-down control.; Secondly, the results show that between-trial, short-term priming plays a large role in determining visual search performance. This result is surprising, as models of visual search emphasize active top-down guidance by advance knowledge of the target more than passive, automatic priming by immediately preceding trials in determining search performance. Finally, the possible neural correlates of these learning mechanisms are discussed. |
