Poster D38, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Individual differences in mixing costs relate to general executive function
Louisa L. Smith1, Naomi P. Friedman1,2, Marie T. Banich1; 1Department of Psychology and Neuroscience, University of Colorado Boulder, 2Institute for Behavioral Genetics, University of Colorado Boulder
Task switching paradigms are used to assess individuals’ ability to enact cognitive control under changing environmental demands. Current accounts of the cognitive processes underlying these tasks focus heavily on active shifting between task sets, i.e. switch costs. However, during trials not requiring a shift, participants must exert sustained control to maintain task goals and overcome interference from competing task sets. The difference in performance between repeat trials within mixed blocks and trials within single-task blocks, i.e. mixing cost, is thought to reflect this additional control demand, but the nature of its processes remain subject to debate. We take a latent variable approach in a large sample (n=749) to investigate mixing costs within an established framework of EFs that captures executive processes common across tasks as well as those unique to specific EFs (Unity/Diversity framework). We first assessed the degree to which individual differences in mixing costs across three different task switching paradigms shared common variance. Each loaded onto a single latent mixing factor (ps<.001) indicating shared underlying processes. Through confirmatory factor analysis, we next investigated the extent to which this latent mixing factor relates to established abilities within the Unity/Diversity framework (Common EF, Updating-Specific, Shifting-Specific). The mixing cost latent variable showed a moderate correlation with the Common EF factor (r=.59, p<.05) and nonsignificant correlations with Updating-Specific and Shifting-Specific (both rs=.11, ps>.10). Results indicate that the additional cognitive control required during mixed block repeat trials relies on common executive processes, as well as unique abilities distinct from both shifting and updating.
Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching