Date of Award
5-1-2024
Degree Name
Doctor of Philosophy
Department
Psychology
First Advisor
Habib, Reza
Abstract
Theories of the attentional blink (AB) – a deficit in responding to the second of two temporally proximal stimuli (within 500 ms; Raymond et al., 1992) – generally explain the deficit as resulting from either the dynamics in top-down and bottom-up attentional process, or limitations in the capacity of the hypothesized attentional process. Extensive basic research has been conducted on the neural correlates of top-down and bottom-up attention as well as on the capacity limitations of attention; however, rather than leading to a single definition, the variety and complexity of results has led several taxonomies which differ systematically with the experimental procedures supposed to evidence them. This lack of consensus is a problem for research attempting to explain specific phenomena such as the AB in terms of the proposed attentional process. This dissertation critically reviews the methods and conclusions of research on attention. In Chapter 2, two prominent conceptualizations of attention are discussed within their historical context and some definitional issues are highlighted. In Chapter 3, research on and theories of the AB are discussed in terms of existing taxonomies of attention. An argument is developed that dynamics in attention, as commonly conceptualized, is not necessarily the mechanism eliciting the AB and data from a series of pilot experiments are interpreted within this hypothesis. In Chapters 4 and 5, two cognitive behavioral experiments are discussed which test whether the AB arises due to localized competition within visual processing areas of the brain. Results from experiment 1 demonstrated a different patter of errors during the AB when the second target appeared in the same stimulus stream as the first target than when they switched streams, suggesting that the mechanisms of the AB are different for this condition. Results from experiment 2 demonstrated the typical AB effect and pattern of errors when target letters were defined by the color of a compound stimulus presented behind the letter stream, but a floor effect when the shape of that compound stimulus defined the targets. Although not definitive, these data might be best interpreted within a localized inhibition account of the AB and are less consistent with the prevailing idea of a late-stage attentional bottleneck.
Access
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