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Pupil size tracks perceptual content and surprise
Niels A Kloosterman1, Thomas Meindertsma, Anouk M van Loon
1Department of Psychology, University of Amsterdam, Weesperplein 4, Amsterdam, 1018XA, the Netherlands; Amsterdam Center for Brain and Cognition, Institute for Interdisciplinary Studies, University of Amsterdam, Amsterdam, the Netherlands.
The European Journal of Neuroscience
|March 11, 2015
Summary
Pupil dilation tracks perceptual content, not just occurrence. Larger pupil dilation during visual target disappearance than reappearance in motion-induced blindness suggests pupil dynamics encode subjective experience.
Area of Science:
- Neuroscience
- Cognitive Science
- Psychology
Background:
- Pupil size changes reflect brainstem activity and global brain states.
- Pupil dynamics can synchronize with cognitive events, like perceptual switches in bistable illusions.
Purpose of the Study:
- To investigate if pupil dilation indicates the content of perceptual switches, not just their occurrence.
- To explore pupil responses during a motion-induced blindness illusion and its replay.
Main Methods:
- Measured pupil diameter in human subjects observing a motion-induced blindness illusion.
- Analyzed pupil dilation amplitude in relation to perceptual disappearance and reappearance events.
- Assessed pupil dilation during a stimulus-evoked replay of the illusion.
Main Results:
- Pupil dilation occurred during perceptual switches and replay.
- Switch-related pupil dilation encoded content, with greater amplitude for disappearance than reappearance.
- Pupil dilation during replay scaled with surprise, but content and surprise effects were independent.
Conclusions:
- Pupil-linked brain systems track both the content and surprise associated with perceptual events.
- Pupil dynamics provide insights into the neural basis of subjective perceptual experience.
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