Poster C32, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Doubly Dissociable Neuromorphological Correlates of Memory and Perceptual Inhibition in Healthy Aging
Teal Eich1, Ray Razlighi1, Derek Nee2, John Jonides3, Yaakov Stern1; 1Columbia University, 2Florida State Univerity, 3University of Michigan
Declines in working memory (WM) are a ubiquitous finding within the cognitive-aging literature. A unitary inhibitory selection mechanism that guides attention towards task-relevant information and resolves interference from task-irrelevant information has been proposed to underlie such deficits. Here, we tested whether the time point in the information-processing stream where inhibition occurs affects older relative to younger adults’ performance. Participants were tested on a set of tasks tapping perceptual and memory inhibition. We found that although older adults were impaired relative to younger adults in inhibiting information on both a perceptual and memorial level, the performance across tasks was not correlated, suggesting dissociable inhibitory processes. To further explore this possibility, we assessed the relationship between cortical thickness and inhibitory performance across the two tasks in a subset of the older adults. We found that worse memory inhibition was associated with cortical thinning in the left Ventral Lateral Prefrontal Cortex (VLPFC), a brain area previously shown to be associated with inhibiting information from WM, but not in the right Superior Parietal Lobule (SPL), an area implicated in the top-down control of attention. On the other hand, while impaired perceptual inhibition was associated with reduced cortical thickness in the right SPL, it was not associated with thinning in the left VLPFC. These results demonstrate a double dissociation between older adults’ performance on two types of inhibitory control tasks and cortical thinning in specific brain areas, and argue against a unitary view of inhibitory control processes.
Topic Area: EXECUTIVE PROCESSES: Development & aging