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Measurement of Neurophysiological Signals of Ignoring and Attending Processes in Attention Control
Published on: July 5, 2015
Perceptual visual grouping under inattention: electrophysiological functional imaging
Irene Razpurker-Apfeld1, Hillel Pratt
1Evoked Potentials Laboratory, Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel. irenea@013.net.il
Brain and Cognition
|March 5, 2008
Summary
Visual grouping complexity impacts processing, even during inattention. Simple grouping patterns are processed under inattention, unlike complex ones, showing distinct brain activity.
Area of Science:
- Cognitive Neuroscience
- Visual Perception
- Electrophysiology
Background:
- Perceptual grouping organizes visual scenes.
- The influence of grouping complexity on unconscious processing is not fully understood.
Purpose of the Study:
- To investigate how visual grouping complexity affects processing under inattention.
- To differentiate the neural correlates of simple versus complex grouping patterns during unawareness.
Main Methods:
- Participants performed a similarity judgment task with simple and complex irrelevant visual grouping patterns.
- Event-related potentials (ERPs) were recorded.
- Source current density was estimated using low-resolution electromagnetic tomography (LORETA).
Main Results:
- Both simple and complex grouping patterns elicited brain activation in occipital, parieto-temporal, and frontal areas, despite subjective unawareness.
- Behaviorally, only simple grouping patterns were processed under inattention.
- Processing of simple patterns showed longer latency and higher activation starting at 130 ms compared to complex patterns.
Conclusions:
- Visual grouping patterns differing in shape formation complexity are distinguishable by the brain, even without conscious awareness.
- The complexity of visual grouping influences its processing under conditions of inattention.
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