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Updated: May 22, 2026
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Methods to Explore the Influence of Top-down Visual Processes on Motor Behavior
Published on: April 16, 2014
Pathways involved in human conscious vision contribute to obstacle-avoidance behaviour
Constanze Hesse1, Alison R Lane, Lina Aimola
1Cognitive Neuroscience Research Unit, Wolfson Research Institute, Durham University, University Boulevard, Stockton-on-Tees TS17 6BH, UK. c.hesse@abdn.ac.uk
The European Journal of Neuroscience
|May 18, 2012
Summary
Patients with visual field defects show perceptual errors in judging line midpoints. These errors also impact obstacle avoidance, indicating that conscious vision pathways are involved, not just subconscious routes.
Area of Science:
- Neuroscience
- Visual Perception
- Cognitive Psychology
Background:
- Patients with primary visual cortex (V1) damage misperceive line midpoints, shifting them towards their blind field.
- Obstacle avoidance tasks, requiring midpoint judgment, are unaffected by these perceptual errors in unilateral neglect patients, suggesting dorsal stream involvement.
- Previous findings showed hemianopia patients avoiding obstacles in their blind field, implying subconscious vision via extrageniculate pathways to the dorsal stream.
Purpose of the Study:
- To investigate if obstacle avoidance relies solely on subconscious vision or also involves conscious vision pathways.
- To examine the influence of the hemianopic perceptual shift on obstacle-avoidance behavior.
Main Methods:
- Compared obstacle-avoidance performance in six patients with left hemianopia and six with right hemianopia.
- Assessed the effect of the hemianopic shift, a known perceptual error in conscious vision tasks, on obstacle avoidance.
Main Results:
- A significant bias was observed in both left and right hemianopia patient groups.
- This bias in conscious visual judgment also affected their performance in the obstacle-avoidance task.
Conclusions:
- Obstacle avoidance behavior is not entirely independent of the visual system responsible for conscious perception.
- Findings suggest that pathways involved in conscious vision contribute to obstacle avoidance, challenging the notion of a purely subconscious route.
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