Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Conferences, Workshops, Symposiums, and Seminars
  4. Contour-integration deficits in intact visual field of hemianopia patients
 
conference paper

Contour-integration deficits in intact visual field of hemianopia patients

Favrod, Ophélie  
•
Herzog, Michael  
•
Paramei, Galina
2015
Perception
38th European Conference on Visual Perception (ECVP)

We investigated Gestalt perception in the intact visual field (VF) of hemianopia patients. Three patients and matched controls performed a Yes-No figure detection task. Gabor patches of one orientation, making up the outline of a square, were embedded in randomly oriented “background” Gabor patches. Continuity of the square outline was modified by changing the orientation of 4 to 12 out of 16 Gabor patches. In addition, background density (BD) varied from low to high. Figure detection in the intact visual field was impaired in a patient with a temporal-parietal lesion but not in a patient with an occipital lesion. Both patients had frequent false positives when only the background elements or fragmented squares were presented. ‘Pathological completion’ occurred more frequently (i) for higher BDs, (ii) when the fragment ends faced the blind VF, and (iii) for central compared to peripheral presentation. The patient with an optical tract lesion had almost normal figure detection at low BD but impaired performance at higher BDs; no ‘pathological completion’ was observed. Our findings indicate that crowding engenders contour integration deficits in the “intact” VF of hemianopia patients. We attribute the deficits to malfunction of the cortical stage of processing in the visual system.

  • Details
  • Metrics
Type
conference paper
Web of Science ID

WOS:000362287800592

Author(s)
Favrod, Ophélie  
Herzog, Michael  
Paramei, Galina
Date Issued

2015

Publisher

Sage Publications Ltd

Publisher place

London

Published in
Perception
Total of pages

1

Volume

44

Start page

295

Subjects

hemianopia

•

intact visual field

•

contour-integration

•

pathological completion

Editorial or Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
LPSY  
Event nameEvent placeEvent date
38th European Conference on Visual Perception (ECVP)

Liverpool, UK

August 23-27, 2015

Available on Infoscience
September 1, 2015
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/117530
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés