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Poster Session: Characterising Visual Evoked Potential contrast response functions using achromatic and chromatic
Joel Martin1, Zoe Darrasse2, Jasna Martinovic1
1The University of Edinburgh.
Journal of Vision
|April 11, 2025
Summary
Visual evoked potentials (VEPs) to chromatic and achromatic stimuli reveal distinct contrast response functions. This study characterizes these differences using Gabor stimuli, providing foundational data for visual neuroscience research.
Area of Science:
- Neuroscience
- Visual Science
- Psychophysics
Background:
- The human visual system differentiates chromatic and achromatic information via cone signals and specific neural mechanisms.
- Visual Evoked Potentials (VEPs) exhibit morphological differences in response to chromatic versus achromatic stimuli.
Purpose of the Study:
- To characterize Visual Evoked Potential (VEP) contrast response functions for chromatic and achromatic Gabor stimuli.
- To establish normative data for VEPs to aid future studies on visual function, particularly in individuals with bipolar disorder.
Main Methods:
- Recorded electroencephalograms (EEGs) while 27 participants viewed chromatic (isoluminant) and achromatic 0.8 cycles per degree Gabor stimuli at varying contrast levels.
- Collected VEPs, detection thresholds, and salience matching data to analyze contrast response functions and individual differences.
Main Results:
- Achromatic stimuli elicited pattern-onset VEPs with a P1 component that saturated at higher contrasts.
- Chromatic stimuli produced a single negative VEP deflection, with amplitude and latency varying more linearly with contrast.
Conclusions:
- Gabor stimuli are suitable for deriving VEP contrast gain functions.
- The study provides initial normative VEP data for chromatic and achromatic stimuli, crucial for future clinical research.
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