Pathways involved in human conscious vision contribute to obstacle-avoidance behaviour

Constanze Hesse, Alison R. Lane, Lina Aimola, Thomas Schenk

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Human patients with visual field defects following damage to their primary visual cortex (V1) will often misperceive the midpoint of a horizontal line. They tend to shift the midpoint away from the real position towards their blind field. In patients with unilateral neglect, where midpoint shifts can also be observed, these perceptual errors do not lead to errors in an obstacle-avoidance task, which also requires the ability to find the midpoint between two obstacles. This dissociation in neglect patients was taken as evidence that obstacle-avoidance performance is guided by visual information from the dorsal visual stream. Recently it was shown that a patient with hemianopia could avoid an obstacle presented in his blind field. This suggests that obstacle-avoidance behaviour can be guided by subconscious vision alone involving a direct route from extrageniculate structures in the brain to dorsal stream areas. To investigate whether obstacle avoidance relies only on this subconscious route or also uses information from pathways involved in conscious vision, we examined the effect of the hemianopic shift on obstacle-avoidance behaviour. This shift is found in tasks where a conscious visual judgement is required and presumably arises in pathways underlying conscious vision (V1 and ventral stream areas). We compared the performance of six patients with left hemianopia with the performance of six patients with right hemianopia. We found a clear bias in both groups, which also affected obstacle-avoidance performance. It is thus concluded that obstacle avoidance does not bypass the system for conscious vision completely.
Original languageEnglish
Pages (from-to)2383–2390
Number of pages8
JournalEuropean Journal of Neuroscience
Issue number3
Early online date16 May 2012
Publication statusPublished - Aug 2012


  • blindsight
  • dorsal
  • hemianopia
  • neglect
  • two-visual systems
  • ventral


Dive into the research topics of 'Pathways involved in human conscious vision contribute to obstacle-avoidance behaviour'. Together they form a unique fingerprint.

Cite this