Poster F5, Tuesday, March 27, 8:00-10:00 am, Exhibit Hall C
Neural Mechanisms Underlying the Interactive Relationship between Working Memory and Cognitive Control During Conflict Processing
Khoi Vo1, Elise Demeter2, Tobias Egner1, Marty Woldorff1; 1Duke University, 2University of North Carolina Charlotte
Recent studies have suggested working memory (WM) and attentional control rely on shared resources. For example, holding a color word in WM during a color-discrimination task can elicit interference similar to the classic Stroop effect. Whether the neural dynamics underlying these behavioral effects differ, however, is unknown. Here, we addressed this question by recording EEG (N=26) during the WM-Stroop and classic-Stroop tasks, as well as a condition where participants held a number (rather than a color-word) in WM during a classic-Stroop task. We focused on the negative-incongruency (Ninc) ERP effect (incongruent-minus-congruent) as a neural marker of conflict processing during the Stroop task, and the P300 to the WM probe as a marker for WM cue representation. Behaviorally, responses in all three color-discrimination tasks were slower and less accurate on incongruent than congruent trials, but this effect did not differ between tasks. In contrast, the Ninc neural effect was elicited in all three color-discrimination tasks, but was substantially earlier and stronger in the WM-color task. We posit that having an active representation of a color word in WM is more difficult to suppress during color-discrimination of a nonmatching color, but this effect is mitigated by earlier and stronger conflict resolution. Behavioral responses to the subsequent WM probes were slower and less accurate following incongruent versus congruent color-discrimination processing, which was reflected in decreased P300s. These results thus suggest cognitive interference degraded WM strength, further supporting the interactive relationship between WM and cognitive control within shared neural resources.
Topic Area: ATTENTION: Nonspatial