Psychology Dictionary

Psychology Terms: P Parallel Processing Parietal Lobes Parsing Path Constraints Pattern Recognition Peg Word Systems Perseveration Phineas Gage Phonemes Phonological Buffer Phonology Photoreceptors Phrase-Structure Ambiguity Phrase-Structure Rules Place of Articulation Pop-out Effect Positron Emission Tomography Post Stimulus Mask Postsynaptic Membrane Pragmatic Reasoning Schema Pragmatic Rules Prefrontal Cortex Preparation Prescriptive Rules Presynaptic Membrane Primacy Effect Primary Motor Projection Areas Primary Sensory Projection Areas Priming Effect Proactive Interference Problem Space Procedural Memories Process Purity Processing Fluency Production Systems Prosody Prosopagnosia Prototype Theory Pseudowords Psycholinguistics

Psychology >> Psychology Dictionary >> Prosopagnosia

Free Email
You@v.gg

Email Login
Password
	New users Sign Up!

Premium Email Services

Personals

Prosopagnosia

A syndrome affecting people with bilateral lesions in the region adjoining the parietal and occipital lobes.

People with prosopagnosia lose their ability to recognize familiar faces (their family members or even themselves) and to make other fine-grained discriminations within a highly-familiar category.

Despite this dramatic deficit, their other visual abilities seem to stay relatively intact.
Prosopagnosic patients can easily and accurately describe visual objects, including facial features.
It is only the conscious recognition of familiar faces that prosopagnosics have difficulty with.

But do they recognize them unconsciously? To answer this question a version of the Guilty Knowledge Test was used. Of course prosopagnosic patients are not guilty of anything, and no one is accusing them of lying when they say they do not reocgnize their family members' faces. But suppose a prosopagnosic patient was presented with a picture of a family member and then heard five names, all of this while the his skin conductance responses were being recorded. In this case, the patients show a marked change in skin conductance when presented with the name of a family member - even when they guess that the picture matched the name of one of the distractors.
The same result is obtained with pictures of famous people.

It appears, then, that although prosopagnosic patients cannot consciously recognize familiar faces, they nevertheless retain the ability to do so at an unconscious, physiological level.

In short, the problem with prosopagnosia (as well as with amnesia) is not that the patients do not know something but that they do not know that they know.