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Stimulus-specific Cortical Visual Evoked Potential Morphological Patterns
Published on: May 12, 2019
Dynamic causal modelling of precision and synaptic gain in visual perception - an EEG study
Harriet R Brown1, Karl J Friston
1Wellcome Trust Centre for Neuroimaging, UCL, London, UK. harriet.brown.09@ucl.ac.uk
Neuroimage
|July 4, 2012
Summary
Higher visual contrast enhances precision in early visual processing by increasing pyramidal cell gain. This effect diminishes in later brain areas, demonstrating how sensory precision is encoded.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Perception
Background:
- Estimating sensory signal precision is crucial for perception.
- Previous models suggest a link between visual contrast and neural precision.
Purpose of the Study:
- To test if increased visual contrast enhances precision in early visual areas via superficial pyramidal cell gain.
- To investigate the neural mechanisms of sensory precision encoding.
Main Methods:
- Electroencephalography (EEG) and dynamic causal modeling (DCM) were employed.
- Source localization identified neural sources of visual responses.
- Bayesian model selection analyzed connectivity and contrast-dependent changes.
Main Results:
- Increased visual contrast led to higher superficial pyramidal cell gain in early visual areas.
- This contrast-dependent gain decreased at higher hierarchical levels.
- EEG and DCM successfully quantified synaptic parameters related to sensory precision.
Conclusions:
- Increased signal-to-noise ratio is represented by enhanced superficial pyramidal cell gain.
- Synaptic parameters encoding sensory precision can be quantified using EEG and DCM.
