The problem of prosopagnosia

Beyn, E.S.

doi:10.1093/neucas/2.6.521-c

Cited by 3 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This patient also exhibited symptoms of prosopagnosia and achromatopsia, which have been reported in several other cases of topographical disorientation (e.g. Bornstein and Kidron, 1959;Beyn and Knyazeva, 1962;Pevzner et al, 1962).…”

Section: Impairments Of Recognition and Identification Of Environmentsupporting

confidence: 74%

Topographical disorientation

Farrell

1996

Neurocase

View full text Add to dashboard Cite

The literature on topographical disorientation is reviewed with respect to different types of spatial representation and modes of navigation. It is argued that there is not a strong case for the existence of separate representations for, on the one hand, the identity of environmental features, and, on the other hand, the location of environmental features relative to other landmarks. Identity and location may be considered more profitably as two aspects of one spatial mapping system, which encodes allocentric spatial relationships and permits landmark-based navigation. Egocentric spatial relationships, however, may also be important in navigation. It is argued that damage to the dorsal areas that are implicated in the updating and manipulation of egocentric reference frames, as well as damage to the allocentric system, may result in topographical disorientation.

show abstract

Section: Impairments Of Recognition and Identification Of Environmentsupporting

confidence: 74%

Topographical disorientation

Farrell

1996

Neurocase

View full text Add to dashboard Cite

show abstract

“…Following the earlier argument that drawing tasks require imagery (e.g., Beyn & Knyazeva, 1962), this leaves as a more likely explanation the possibility that children with autism had a deficit in the processing of images of unreal objects. Since both the spontaneous (Condition 1) and the instructed (Condition 2) responses of the subjects with autism were reality-based, it may be that this is the only way in which these subjects are capable of thinking.…”

Section: Discussionmentioning

confidence: 95%

“…Tasks requiring subjects to produce drawings of objects arguably also require the subject to entertain a mental image of that object, and thus drawing tasks have been used to explore mental imagery in patients who have suffered brain damage (e.g., Beyn & Knyazeva, 1962; Levine et al, 1985) as well as in normal development (see e.g., Thomas & Silk, 1990). Drawing in autism has been explored in the past to see if children with autism (including those who do not exhibit a precocious drawing talent) follow the same pattern of development as normal children in their attempts to represent what they see before them.…”

Section: Introductionmentioning

confidence: 99%

Imagining Real and Unreal Things: Evidence of a Dissociation in Autism

Scott

Baron‐Cohen

1996

Journal of Cognitive Neuroscience

153

105

View full text Add to dashboard Cite

Current theories of visual imagery hold that the same neural processes govern both the representation of real objects and the representation of imagined (but real) objects. Here we test whether the representation of imagined (real) objects and the representation of imagined (but unreal) objects depend on the same or different neurocognitive processes. A likely clinical group for a dissociation between these two types of imagination are children with autism, since they show deficits in imaginative play, impoverished imagination is part of their diagnosis, but they can search for hidden objects. The present study explored imagination in autism using experimental methods. Experiment 1 investigated if children with autism could introduce changes to their representations of people and houses, using Karmiloff-Smith's (1989) technique of asking children to draw "impossible" people or houses. Results showed that children with autism were significantly worse than matched controls in their ability to introduce "unreal" changes to their representations of people and houses. Instead, they tended to draw real people or objects. Experiment 2 investigated whether the performance in Experiment 1 by children with autism was due to an inability to disengage from "real world" representations, as executive dysfunction theorists would argue. To do this, the experimenter instructed them on what to draw and how to draw it. Results showed that even when executive control passed to the experimenter in this way, the children with autism were still significantly impaired in their ability to draw imaginary but unreal things relative to the matched controls. Experiment 3 investigated whether the results from Experiments 1 and 2 arose because of a generativity deficit in autism, which might be the executive dysfunction theorists' alternative account. To test this, the same subjects were given a test of Verbal Fluency and a test of imagining multiple functions of a brick. Results showed that the children with autism were no worse than clinical controls in their ability to generate ideas about real objects, suggesting that a global generativity deficit cannot explain the previous findings. Rather, these results point to a specific impairment in the ability to imagine unreal objects. This is discussed in terms of its possible neural dissociability from other kinds of imagery, and in terms of its possible relationship to theory of mind.

show abstract

“…RP confesses attending to hair as a way to collect clues on persons' identity. The use of such strategy can allow him to get by in a limited way in controlled social interactions (as it has been reported also for other prosopagnosics; Ariel & Sadeh, 1996;Bodamer, 1947Bodamer, /1990Beyn & Knyazeva, 1962). RP's accuracy and efficiency in making estimates of the sex and age of a face were evaluated in a task in which hair-based cues were entirely absent (i.e., photos of bald-shaved female and male models).…”

Section: Assessment Of Rp's Deficit With Face Stimulimentioning

confidence: 99%

Prosopagnosia as a Deficit in Encoding Curved Surface

Laeng

Caviness

2001

Journal of Cognitive Neuroscience

View full text Add to dashboard Cite

RP is a case of "developmental" prosopagnosia who, according to brain-imaging segmentation data, shows reduction in volume of a limited set of structures of the right hemisphere. RP is as accurate as control subjects in tasks requiring the perception of nonface objects (e.g., matching subordinate labels to exemplars, naming two-tone images), with the exception of one perceptual task: The matching of different perspectives of amoebae-like stimuli (i.e., volumes made of a single smooth surface). In terms of speed ("efficiency") of responses, RP's performance falls clearly outside the normal limits also in other tasks that include "natural" but nonface stimuli (i.e., animals, artia facts). Specifically, RP is slow in perceptual judgments made at very low (subordinate) levels of semantic categorization and for objects and artifacts whose geometry present much curved features and surface information. We conclude from these analyses that prosopagnosia can be the result of a deficit in the representation of basic geometric volumes made of curved surface. In turn, this points to the importance (necessity) for the normal visual system of such curved and volumetric information in the identification of human faces.

show abstract

The problem of prosopagnosia

Cited by 3 publications

References 0 publications

Topographical disorientation

Topographical disorientation

Imagining Real and Unreal Things: Evidence of a Dissociation in Autism

Prosopagnosia as a Deficit in Encoding Curved Surface

Contact Info

Product

Resources

About