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Later Positivity Reflects Post-perceptual Processes: Evidence From Immediate Detection and Delayed Detection Tasks
1Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China.
Frontiers in Psychology
|February 16, 2019
Summary
This study differentiates visual awareness from post-perceptual processing using electrophysiology. Visual awareness negativity (VAN) reflects early visual awareness, while later positivity (LP) indicates post-perceptual reporting processes.
Area of Science:
- Neuroscience
- Cognitive Science
- Psychology
Background:
- Electrophysiological recordings are crucial for understanding neural correlates of consciousness (NCCs).
- Distinguishing neural signals of awareness from subsequent processing is challenging.
- Previous studies identified visual awareness negativity (VAN) and later positivity (LP) as potential NCCs.
Purpose of the Study:
- To dissociate electrophysiological correlates of visual awareness from post-perceptual processes.
- To investigate the temporal dynamics of visual awareness and reporting.
- To clarify the roles of VAN and LP in visual perception.
Main Methods:
- Utilized two detection tasks: immediate and delayed stimulus reporting.
- Employed electrophysiological recordings to measure brain activity.
- Analyzed the amplitude of VAN and LP under different task conditions.
Main Results:
- VAN amplitude remained unaffected by task manipulation, suggesting it reflects early visual awareness.
- LP amplitude was significantly influenced by task demands between 650-850 ms.
- This indicates LP is associated with post-perceptual processing for reporting.
Conclusions:
- VAN is an early electrophysiological marker of visual awareness.
- LP reflects post-perceptual processes involved in reporting perceptual awareness.
- The study successfully dissociates neural signatures of awareness from reporting.
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