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Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation
Published on: May 12, 2014
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Single pulse electrical stimulation in white matter modulates iEEG visual responses in human early visual cortex
Harvey Huang1, Kendrick N Kay2, Nicholas M Gregg3
1Mayo Clinic Medical Scientist Training Program, Mayo Clinic, Rochester, MN.
Biorxiv : the Preprint Server for Biology
|July 14, 2025
Summary
Single electrical pulses can alter brain activity. This study shows electrical stimulation adds noise to broadband signals but amplifies visual evoked potentials, enhancing visual processing.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Computational Neuroscience
Background:
- Electrical stimulation is a key tool for modulating brain networks in clinical settings.
- The precise mechanisms by which single electrical pulses affect connected neuronal populations remain unclear, with possibilities including excitation, inhibition, or noise addition.
- Understanding these mechanisms is crucial for optimizing neurostimulation therapies.
Purpose of the Study:
- To investigate how single electrical pulses modulate neuronal processing of visual stimuli.
- To differentiate the effects of electrical stimulation from visual processing on brain activity.
- To elucidate the interaction between electrical stimulation and visual evoked potentials.
Main Methods:
- Utilized intracranial electroencephalography (iEEG) in two human subjects with electrodes in white matter tracts and visual cortex.
- Delivered single electrical pulses followed by visual stimuli at varying onset times (0, 100, 200 ms).
- Applied finite impulse response (FIR) modeling to decompose broadband and evoked potential responses into stimulation- and visually-induced components.
Main Results:
- Single electrical pulses induced transient broadband increases followed by suppression, demonstrating an additive effect on broadband power, potentially via noise.
- Electrical stimulation did not modulate visual broadband responses.
- Single pulses elicited distinct brain stimulation evoked potentials and significantly modulated visual evoked potentials, amplifying them when stimulation preceded visual onset.
Conclusions:
- Electrical stimulation has dual effects on visual system processing: additive effects on broadband power and amplification of visual evoked potentials.
- Single electrical pulses can enhance the strength or synchrony of visual inputs.
- Findings suggest that electrical stimulation interacts with neural processing to modulate sensory input, with implications for neurostimulation efficacy.
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