Perceptual filling in of artificially induced scotomas in human vision

Patients with scotomas or blind-spots in their visual field resulting from damage to the visual pathways often report that the pattern from the rest of the visual field 'fills in' to occupy the scotoma. Here we describe a novel technique for generating an artificial perceptual scotoma whic...

Full description

Saved in:
Bibliographic Details
Published in:Nature (London) 1991-04, Vol.350 (6320), p.699-702
Main Authors: Ramachandran, V. S, Gregory, R. L
Format: Article
Language:English
Subjects:
Biological and medical sciences
Eyes & eyesight
Humans
Medical research
Medical sciences
Ophthalmology
Optic Disk
Retina - physiology
Retina - physiopathology
Scotoma - physiopathology
Vision disorders
Vision, Ocular
Visual Cortex - physiology
Visual Cortex - physiopathology
Visual Pathways - physiology
Visual Pathways - physiopathology
Visual Perception
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Patients with scotomas or blind-spots in their visual field resulting from damage to the visual pathways often report that the pattern from the rest of the visual field 'fills in' to occupy the scotoma. Here we describe a novel technique for generating an artificial perceptual scotoma which enabled us to study the spatial and temporal characteristics of this filling-in process. A homogeneous grey square subtending 1.5 degrees was displayed against a background of twinkling two-dimensional noise of equal mean luminance. On steady eccentric fixation for 10 s the square vanished and was filled in by the twinkling noise from the surround. Using this display we found that 'filling in' is an active visual process that probably involves creating an actual neural representation of the surround rather than merely ignoring the absence of information from the scotoma; filling in can occur separately for colour and texture, suggesting separate mechanisms; the filling-in process does not completely suppress information from the scotoma, even after an image has faded completely from consciousness it can nevertheless contribute to motion perception; and the process can be strongly influenced by illusory contours.
ISSN:0028-0836
1476-4687
DOI:10.1038/350699a0