Poster C48, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Predicting Individual tDCS-Linked Working Memory Benefits Through Resting-State fMRI
Adelle Cerreta1, Ryan Mruczek2, Marian Berryhill1; 1University of Nevada, Reno, 2Worcester State University
Working memory (WM) improvement is sought in training protocols because it is essential for most cognitive tasks. New reports suggest WM improvement follows cognitive training paired with anodal transcranial direct current stimulation (tDCS) targeting frontoparietal networks. One unexpected observation is that general benefits across participants emerge after multiple paired sessions, whereas only a subset of participants benefit after a single session. One explanation is that some participants have greater connectivity in task-relevant networks so a single tDCS session elicits improved WM performance, whereas participants with less connectivity may require more sessions to achieve similar benefits. We term this the Hypothesis of tDCS: Deepen or Grow (HOT:DOG). To test HOT:DOG we collected resting-state fMRI (rs-fMRI) connectivity scans prior to conducting a 5-session tDCS+WM training study. This permitted evaluations of correlations between default mode network (DMN) connectivity at rest and first day performance, echoing the single session paradigms, and with final day performance, echoing multiple session paradigms. The top and bottom third of OSPAN scores on Day 1 correlated with a significant difference in DMN connectivity in the right occipital lobe (MNI: 54, -66, 17), while Day 5 average task performance correlated with a significant difference in DMN connectivity in right occipitotemporal cortex (MNI: 48, -50, -4). These results show that after both a single session and 5 sessions of tDCS, participants with stronger DMN connectivity at rest exhibited higher WM performance scores. Further research will pinpoint the location and amount of stimulation necessary to grow connections in the low performing groups.
Topic Area: EXECUTIVE PROCESSES: Working memory