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Updated: Nov 6, 2025
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Visualizing Visual Adaptation
Published on: April 24, 2017
9.2K
The human visual system differentially represents subjectively and objectively invisible stimuli.
Timo Stein1, Daniel Kaiser2, Johannes J Fahrenfort1,3
1Brain and Cognition, Department of Psychology, University of Amsterdam, the Netherlands.
Plos Biology
|May 5, 2021
Summary
Measuring conscious awareness impacts understanding of unconscious processing. Different methods reveal varying levels of information in visual cortex, affecting theories of consciousness.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Visual Perception
Background:
- Assessing unconscious processing necessitates measuring conscious awareness.
- Awareness measures are subjective (self-report) or objective (performance-based).
- The choice of awareness measure can influence conclusions about unconscious processing and its neural basis.
Purpose of the Study:
- To investigate how subjective versus objective awareness measures affect the detection of information processing in visual cortex.
- To compare the neural correlates of consciousness associated with different awareness measurement approaches.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was used to measure brain activity in 43 subjects.
- Subjects viewed masked faces and houses under conditions of subjective or objective invisibility.
- Category information was analyzed in different visual processing areas.
Main Results:
- Objectively invisible stimuli showed category information in both early and higher-level visual areas.
- Subjectively invisible stimuli exhibited a posterior-to-anterior gradient of information, similar to visible stimuli.
- Information processing for objectively invisible stimuli remained consistent across visual hierarchy, unlike subjective invisibility.
Conclusions:
- The extent of unconscious information processing is influenced by the chosen measurement approach (subjective vs. objective).
- Subjective and objective awareness measures are linked to distinct neural correlates of consciousness.
- Findings have implications for understanding consciousness and developing neural theories of awareness.
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