Date of Degree
PhD (Doctor of Philosophy)
Shaun P. Vecera
Complex behaviors require selectively attending to task-relevant items, and ignoring conspicuous, irrelevant items. For example, driving requires selectively attending to other cars on the road while ignoring flashing billboards. Dominant models of attentional control posit that we avoid distraction by biasing attention towards task-relevant items, and our ability to avoid distraction depends on the strength and specificity of this bias. I find that a strong, specific bias towards task-relevant items is insufficient for preventing distraction. Instead, preventing distraction also requires past experience ignoring distractors. I also find that long-term memory systems, rather than visual short-term memory or priming memory systems, maintain this experience. Based upon these findings, I propose that effective attentional control not only demands a strong, specific bias towards task-relevant items, but also requires that observers learn to ignore conspicuous, irrelevant items.
When driving, maintaining attention on task-relevant items, such as other cars on the road, is critical for avoiding dangerous events. Attention researchers posit that maintaining attention on task-relevant items depends solely on our ability to discriminate between relevant and irrelevant items. For instance, when we can easily discriminate between relevant items, such as cars, and irrelevant items, such as billboards, we selectively attend the relevant items. When we cannot discriminate between relevant and irrelevant items, we attend to both the relevant and irrelevant items. Here, I test whether target discriminability is sufficient for preventing distraction of if we also must learn to ignore conspicuous items. I find that even when participants can easily discriminate between relevant and irrelevant items, participants must learn to ignore conspicuous items. Without this learning, the conspicuous items distract participants. I call this learned distractor rejection. I go on to investigate how participants maintain learned distractor rejection. I find that the learned ability to ignore conspicuous distractors persists over extended delays, demonstrating that long-term memory systems support learned distractor rejection. These results indicate that our ability to maintain attention on task-relevant items not only depends on our ability to discriminate between relevant and irrelevant items, but also our learned ability to ignore conspicuous items and this learning persists over extended periods of time.
publicabstract, Attention, Attentional Capture, Attentional Control, Distraction, Distractor Rejection, Experience and attentional control
ix, 100 pages
Includes bibliographical references (pages 90-100).
Copyright 2015 Daniel Brown Vatterott