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Updated: Jun 25, 2026
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Stimulus-specific Cortical Visual Evoked Potential Morphological Patterns
Published on: May 12, 2019
Perceiving electrical stimulation of identified human visual areas
Dona K Murphey1, John H R Maunsell, Michael S Beauchamp
1Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA. dmkim@post.harvard.edu
Summary
Electrical stimulation of human visual cortex can evoke simple percepts. Detection probability varied by visual area, but percept quality and stimulation thresholds were similar across early and late visual areas.
Area of Science:
- Neuroscience
- Visual Perception
- Electrophysiology
Background:
- Electrical stimulation of the brain can evoke percepts.
- Functional magnetic resonance imaging (fMRI) aids in identifying specific visual areas.
- Local-field potentials can confirm the functional selectivity of electrode placement.
Purpose of the Study:
- To investigate if electrical stimulation of human visual areas elicits detectable percepts.
- To determine how the probability of detecting percepts varies with the location in the visual hierarchy.
- To characterize the quality and threshold of percepts elicited by stimulation.
Main Methods:
- Intracranial electrodes were placed over human visual areas identified by fMRI.
- Local-field potentials were recorded to confirm functional area identification (e.g., face-selective responses in FFA).
- Electrical stimulation was applied, and subjects reported percepts in a detection task, with thresholds determined by varying current.
Main Results:
- Stimulation of early visual areas (V1, V2, V3) was almost always detected.
- Stimulation of late visual areas (e.g., FFA) was rarely detected.
- Percepts from late areas were simple shapes and colors, similar to those from early areas; no elaborate percepts were reported.
Conclusions:
- The probability of detecting electrical stimulation varies with visual cortical hierarchy.
- Percept quality and detection thresholds are similar across early and late visual areas.
- Functional microcircuits likely link electrical stimulation to perception, regardless of area complexity.
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