Dissociation between mental imagery and object recognition in a brain-damaged patient

  title={Dissociation between mental imagery and object recognition in a brain-damaged patient},
  author={Marlene Behrmann and Gordon Winocur and Morris Moscovitch},
VISUAL imagery is the creation of mental representations that share many features with veridical visual percepts. Studies of normal and brain-damaged people reinforce the view that visual imagery and visual perception are mediated by a common neural substrate and activate the same representations1–4. Thus, brain-damaged patients with intact vision who have an impairment in perception should have impaired visual imagery. Here we present evidence to the contrary from a patient with severely… 
Intact visual imagery and impaired visual perception in a patient with visual agnosia.
A model in which imagery and perception are strongly associated but are also functionally specialized is proposed, in which C.K. was able to draw objects in considerable detail from memory, and his knowledge of the visual appearance of objects was preserved on a variety of mental imagery tasks.
Disentangling visual imagery and perception of real-world objects
Is there a common substrate for visual recognition and visual imagery
Abstract An analysis of cases of preserved imagery with disturbed perception of objects suggests that visual imagery does not depend on the integrity of topographically organized early visual cortex
Visual and mental exploration of visuo-spatial configurations: Behavioral and neuroimaging approaches
The findings of a research program based on the mental scanning paradigm reveal the similarities and differences between the two kinds of mental images.
Effects of peripheral and central visual impairment on mental imagery capacity


Preserved Visual Imagery and Categorization in a Case of Associative Visual Agnosia
A patient with associative visual agnosia secondary to a penetrating bitemporooccipital lesion remained able to draw complex objects from memory but could not subsequently recognize his sketches, infering a preserved ability to derive internal visual images from semantic memory.
Is visual imagery really visual? Overlooked evidence from neuropsychology.
  • M. Farah
  • Psychology, Art
    Psychological review
  • 1988
Previously overlooked neuropsychological evidence on the relation between imagery and perception is reviewed, and its relative immunity to the foregoing alternative explanations is discussed.
Loss of visual imagery : a generation deficit
Abstract The case of a patient with an impairment in the ability both to generate visual images and to perform certain transformations upon visual images in reported. No impairment of long-term
A case study of mental imagery deficit
A case of integrative visual agnosia.
The results demonstrate that agnosia may be determined by a specific deficit in integrating form information; and that the input description for visual object recognition, disrupted in this patient, is functionally separate from stored object descriptions, which are intact.
Case report of a visual integrative agnosia
Abstract We report the case of a patient with a major defect in visual object recognition after vascular damage in posterior regions of both cerebral hemispheres. We conclude that our subject
A system for drawing and drawing-related neuropsychology
Abstract Drawing and copying are complex synthetic activities. They can be based on visual inputs (designs, pictures, or objects) that are present while the subject is drawing or that are removed
Information representation in visual images