Traditionally, mainstream models of attention have neglected the role of motivationally meaningful stimuli (e.g. threat/reward). These stimuli can cause the rapid and involuntary attraction of attention (attentional capture), and can hence be said to have motivational salience. It is sometimes considered that this capture occurs in a stimulus-driven manner (versus goal-driven). I, however, suggest that attentional capture by motivational salience could be caused by a goal-driven mechanism. To test this we asked three overarching questions: 1) Is detecting motivationally salient stimuli considered important? By using a novel concurrent forced choice task, which isolates the priority of an individual's explicit search goals, we found that individuals believed that it was advantageous to detect and search for motivationally salient stimuli. 2) Can voluntary search goals induce attentional capture? In Chapter 2 we revealed that task-irrelevant threatening stimuli only captured attention, versus neutral distractors, when participants were searching for that category of threatening stimuli. This goal-driven capture effect was robust yet highly specific, affecting only the single specific semantic category, rather than generalising across all related stimuli (Chapter 3). We found an identical pattern of results for reward associated stimuli (alcohol in social drinkers) in Chapter 4, with capture only occurring in the goal-driven condition. The same was true for smoking related images in Chapter 5, and this occurred independently of current nicotine dependence. Additionally, self-selected search goals were capable of inducing attentional capture, not just instructed goals (Chapter 7). 3) How are top-down search goals initially selected? Chapter 6 revealed that search goal priority was positively predicted by stimulus importance and expectancy. This task also revealed a contextual cueing effect on search goal priority, whereby threat was prioritised more in a threatening context (versus safe). On the basis of my findings we propose a novel Importance-Expectancy model of attentional goal selection.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:751879 |
| Date | January 2018 |
| Creators | Brown, Christopher |
| Publisher | University of Sussex |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://sro.sussex.ac.uk/id/eprint/76861/ |
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