biostudies-literatureUnknownAtalay ASNICHD NIH HHSNINDS NIH HHSTo enhance mechanistic understanding of effective connectivity in the human brain, we created a tool that links high-temporal resolution transcranial magnetic stimulation electroencephalography (TMS-EEG) with high-spatial resolution diffusion MRI. This tool, Surface to Tractography Real-time EEG Activation Mapping in 4 Dimensions (STREAM-4D), integrates electrophysiologic source estimation models from TMS-evoked potentials (TEPs) with structural connectivity models from diffusion MRI tractography. In a proof-of-principle application, we used STREAM-4D to analyze TMS-EEG and diffusion MRI tractography data in a neurotypical subject across three stimulation sites: premotor, parietal, and occipital cortex. STREAM-4D revealed extensive structural connections associated with the TMS-evoked sourbioRxiv : the preprint server for biology2025.03.06.641642https://www.ebi.ac.uk/biostudies/studies/S-EPMC11952297biostudies-literatureVisualizing Effective Connectivity in the Human Brain.PMC11952297DP2 HD101400R01 NS138257Atalay ASEdlow BLFecchio MfalseVisualizing Effective Connectivity in the Human Brain.To enhance mechanistic understanding of effective connectivity in the human brain, we created a tool that links high-temporal resolution transcranial magnetic stimulation electroencephalography (TMS-EEG) with high-spatial resolution diffusion MRI. This tool, Surface to Tractography Real-time EEG Activation Mapping in 4 Dimensions (STREAM-4D), integrates electrophysiologic source estimation models from TMS-evoked potentials (TEPs) with structural connectivity models from diffusion MRI tractography. In a proof-of-principle application, we used STREAM-4D to analyze TMS-EEG and diffusion MRI tractography data in a neurotypical subject across three stimulation sites: premotor, parietal, and occipital cortex. STREAM-4D revealed extensive structural connections associated with the TMS-evoked sour2025-01-01T00:00:00Z2025 Mar2025-07-07T03:09:18.492Z2025-07-07T03:09:18.492ZS-EPMC119522974016174910.1101/2025.03.06.641642