Interleaved TMS-fMRI Explains Variability in TMS Response

Motivation: TMS has become an invaluable asset in both research and clinical environments. However, variability in individual responses to TMS is a persistent issue, which limits its broader adoption. Goal(s): The integration of TMS with fMRI through interleaved paradigms is a promising strategy for gaining insights into the factors that underlie this response variability. Approach: Adopting an interleaved TMS-fMRI approach we explored the different factors of stimulation dose, sex differences, and cognitive state. Results: Interleaved TMS-fMRI revealed individual dose-response patterns. Inherent sex differences were found between men and women. Precise timing of TMS relative to cognitive state demonstrated differential effects on relevant brain regions. Impact: The findings represent a critical step toward addressing the challenge of response variability. TMS-fMRI promises to be a valuable tool for not only understanding factors that influence TMS response but also for potentially enhancing response rates in TMS applications.