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Published on: April 16, 2014
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Shared and Diverging Neural Dynamics Underlying False and Veridical Perception
Joost Haarsma1, Dorottya Hetenyi2, Peter Kok2
1Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, United Kingdom joost.haarsma@maastrichtuniversity.nl.
Summary
False perceptions, like seeing gratings in noise, involve brain signals similar to real ones. High confidence in false perceptions uniquely involves increased prestimulus alpha/beta brainwave power.
Area of Science:
- Neuroscience
- Cognitive Science
- Visual Perception
Background:
- False visual perceptions can be as convincing as veridical ones, suggesting overlapping neural mechanisms.
- False perceptions likely originate from internally generated signals, distinct from external stimuli.
Purpose of the Study:
- To investigate the neural overlap between veridical and false visual perception.
- To analyze how the brain processes content discrimination and detection in both true and false percepts.
- To identify unique neural signatures associated with high-confidence false perceptions.
Main Methods:
- Applied multivariate analyses to human magnetoencephalography (MEG) data.
- Participants performed a visual discrimination task with and without actual grating stimuli.
- Noise-only trials were designed to exclude external orientation signals.
Main Results:
- Decoding analyses identified sensory signals corresponding to the content of false percepts.
- High-confidence false percepts, unlike veridical ones, correlated with increased prestimulus alpha/beta power (11-14 Hz).
- A shared neural code for confidence in stimulus presence was observed for both false and veridical percepts.
Conclusions:
- False visual percepts are underpinned by neural signals for both sensory content and detection, mirroring veridical perception.
- Increased prestimulus alpha/beta power is a unique neural correlate of high-confidence false perceptions, possibly indicating top-down influence.
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