Understanding the role of visual transients and the temporal autocorrelation of features in extending and closing the attentional window
Open Access
- Author:
- Callahan-Flintoft, Chloe
- Graduate Program:
- Psychology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- March 25, 2019
- Committee Members:
- Bradley Paul Wyble, Dissertation Advisor/Co-Advisor
Bradley Paul Wyble, Committee Chair/Co-Chair
Richard Alan Carlson, Committee Member
Frank Gerard Hillary, Committee Member
John Collins, Outside Member - Keywords:
- Attentional drag theory
attention
feature extraction
N2pc - Abstract:
- Reflexive attention allows the visual system to rapidly select and prioritize important visual information. As our environments are often changing, it is important to understand how this selection process occurs in time. To this end, previous literature finds conflicting results. Discrete display paradigms such as Rapid Serial Visual Presentation (RSVP) find that attention is able to select information presented simultaneously with a cue (Goodbourn & Holcombe, 2015) whereas smoothly changing displays show evidence that attention lags in extraction, selecting information presented over 100 ms after a cue (Carlson, Hogendoorn & Verstraten, 2006). The attentional drag theory, a conceptual model of attention proposed in this dissertation, accounts for this difference by attributing the latency in selecting information not to a difference in the latency of attentional onset, as has been previously hypothesized, but rather to a difference in the duration of attentional engagement. The model proposes that the temporal autocorrelation of a feature (i.e. when features are perceived as smoothly changing) maintains attentional engagement longer, extending the attentional window in time, which results in a later feature selection. Conversely, a visual transient, such as a salient change in the feature of an object, closes the attentional window, allowing for fewer feature values to receive attentional amplification, and, consequently, an earlier selection. The aim of this dissertation is to test the underlying assumptions of the attentional drag theory. Firstly, the effect is demonstrated in a second feature dimension (orientation) and it is shown that the temporal autocorrelation presented after the onset of attention, rather than before, produces the selection latency increase. In examining the influence of a visual transient on attentional engagement, results showed that a transient presented in a task-irrelevant feature can trigger the disengagement of attention. However, this transient needs to be presented at the attended location in order to have such an effect. This influence of one feature’s transient on another’s sampling did not prove to be reciprocal though. When two features were extracted from the same object it was found that a transient in orientation reduced the selection latency of color but a transient in color did not have an effect on the selection latency of orientation. Finally, exploratory analyses were performed on EEG data collected during feature information extraction, but no neural correlates for the varied duration of the attentional window were found. Together the results outline how visual transients and the temporal autocorrelation of a feature affect attentional sampling and could shed important insights into how the brain parses information in time to construct coherent object representations.