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Updated: Sep 9, 2025
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Detecting Pre-Stimulus Source-Level Effects on Object Perception with Magnetoencephalography
Published on: July 26, 2019
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Pre-stimulus Microstates and Bodily Signals Independently Influence Perceptual Awareness at the Discrimination
Viviana Leupin1, Juliane Britz2
1Department of Psychology, University of Fribourg, University of Fribourg, Rue P.-A. Faucigny 2, Fribourg, CH-1700, Switzerland.
Brain Topography
|August 28, 2025
Summary
Brain and body states independently influence visual perception. Specific EEG microstates (like D) and breathing phases (like inhalation) correlate with unawareness and arousal, respectively, but do not interact.
Area of Science:
- Neuroscience
- Cognitive Science
- Psychology
Background:
- Perceptual awareness is influenced by brain states (EEG microstates) and bodily signals (cardiac, respiratory cycles).
- The interplay between brain and body states in modulating awareness remains unclear.
Purpose of the Study:
- To investigate if pre-stimulus EEG microstates and cardiac/respiratory phases jointly or independently influence awareness of threshold visual stimuli.
- To determine the specific contributions of brain and body states to subjective awareness.
Main Methods:
- An orientation discrimination task was employed to assess awareness of threshold visual stimuli.
- Pre-stimulus EEG microstates were analyzed for aware versus unaware trials, considering cardiac and respiratory phases.
- Statistical comparisons were made between conditions.
Main Results:
- Canonical Microstate D, linked to attentional networks, was more frequent in unaware trials.
- Canonical Microstate A showed greater variance during inhalation, suggesting increased arousal.
- No significant interaction was found between bodily phase and awareness, indicating independent influences.
Conclusions:
- Pre-stimulus brain states and bodily phases independently modulate perceptual awareness.
- Microstate D predicts unawareness, while inhalation is associated with heightened arousal.
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