Schedule of Events | Symposia

Sketchpad Series

Modulation of Cognitive Control and Reading &Language Networks through Noninvasive Brain Stimulation: pilot results for in-scanner tACS

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom

Katherine Aboud¹, Clair Min Kyung Hong², Andrew Janson³; ¹Vanderbilt University

Reading comprehension is critical for success, but one in five US adults struggle to understand written text. Despite extensive research, effective interventions remain elusive. To address this urgent need, we employed a cutting-edge, in-scanner non-invasive brain stimulation intervention targeting specific network pathways supporting positive RC outcomes. Previous work has found that communication between cognitive control network (CCN) and reading and language network (RLN) hubs supports greater resilience to difficulty during reading comprehension. Here, we present our preliminary findings from in-scanner high-definition transcranial alternating current stimulation (HD-tACS) with a novel application of joint independent component analysis (jICA) of fMRI and EEG data. We administered low-intensity tACS (2 mA; individualized theta frequency) to the left dorsolateral prefrontal cortex (DLPFC) and/or the left angular gyrus (AG) for 25 minutes while participants read expository text passages in the MRI scanner. We found early evidence that stimulation, compared to sham, impacts reading comprehension measures and modulates areas important for comprehending text, including areas in the default mode network. Furthermore, functional connectivity analysis from a 7-minute pre- vs. post-stimulation resting-state fMRI showed increased connectivity between frontal and parietal lobes after stimulation. This increased connectivity suggests more efficient cognitive control mechanisms such as facilitating semantic integration, retrieval, and maintenance of relevant contextual information. This pilot study lays out a framework in which to implement non-invasive brain stimulation in the enhancement of discourse comprehension and provides insight into the effects of stimulation on brain network activation.

Topic Area: LANGUAGE: Other