Name: Cody A. Mashburn

Ph.D. Dissertation Proposal Meeting

Date: Monday, April 15th, 2024

Time: 3:30pm EST

Location: J.S. Coon 148 and/or virtual: https://gatech.zoom.us/j/97526894452

Dissertation Chair/Advisor:

Dr. Randall Engle—School of Psychology, Georgia Institute of Technology

Dissertation Committee Members:

Dr. Rick Thomas—School of Psychology, Georgia Institute of Technology

Dr. Mark Wheeler—School of Psychology, Georgia Institute of Technology

Dr. Scott Moffat—School of Psychology, Georgia Institute of Technology

Dr. Andrew Conway—Department of Psychology, New Mexico State University

Title: Explaining individual differences in the rate of focusing attention: Dissociating attention control from drift rates

Abstract: The top-down control of attention and the speed of information processing are two candidate causes of individual differences in other higher order cognitive abilities. However, the relationship between attention control and processing speed remains unclear. While some studies show that the two constructs are related but distinct (e.g., Burgoyne et al., 2023), others contend that the two constructs are virtually indistinguishable (Löffler et al., 2024). The proposed study adds to this discussion by comparing attention control and processing speed as measured by drift rates from the Ratcliff (1978) drift-diffusion model for predicting working memory capacity and fluid intelligence. This will reveal whether attention control and drift rates are unique and whether one is more important for predicting higher-order abilities. This study also goes beyond previous correlational approaches and compares attention control and processing speed as explanations of individual differences in selective attention across two versions of an Eriksen flanker task (Eriksen & Eriksen, 1974). Flanker tasks require participants to identify the central target stimulus in a string of other symbols. These symbols can either match the target symbol (e.g., HHHHH) or they can differ from the central target (e.g., HHSHH). When the central target differs from the others, participants must selectively attend to the central target to respond accurately. Those with better attention control are expected to focus attention on incongruent trials more quickly than those lower in attention control (Heitz & Engle, 2007). If participants with faster in drift rates also focus attention faster than those with slower drift rates, this will indicate that drift rates are sensitive to individual differences in selective attention. If they do not, then this will be evidence for discriminant validity between attention control and drift rates.