Showing papers on "Facial recognition system published in 1966"

Facial recognition in brain-damaged patients. An experimental approach.

Abstract: THE FIELD OF AGNOSIA recently has been broadened by a new form which, in the opinion of many authors, possesses an individual character and a certain significance for localization: agnosia for faces or prosopagnosia. Patients with this disorder complain that they are no longer able to recognize even very familiar faces, such as those of dose relatives, without recourse to noting significant features of the face, such as a birthmark, mustache, or scar; visual details not connected with the face, such as clothing; or nonvisual characteristics, such as tone of voice. Bodamerl was the first to distinguish between this form of agnosia and object agnosia, to which it previously had been ascribed. The cases which have been described since then, as well as the interpretation given to them, recently have been summarized by Gentili and associates2 and H6caen and Angelergues.3 The explanations of the nature of this symptom may be outlined as follows: 11 Prosopagnosia is a distinctive type of agnosia caused by the impairment of a specialized perceptual ability (the recognition of human faces) which starts developing separately during the first months after birth.4 21 Prosopagnosia is not an autonomous condition, just as the other specialized forms of agnosia are not autonomous conditions. All these errors in visual recognition may be related to impairment of visual perception, which is altered quantitatively as well as qualitatively in terms of either an abnormal “Funktionswandel”5,6 or a deficit of morphosynthesis.2 A majority of the authors who have examined prosopagnostic patients, however, are skeptical that a postulated defect in visual analyzers can suffice to explain the symptom. Furthermore, HCcaen and Angelergues3 note that, in contrast to object agnosia, prosopagnosia tends to be more frequent in patients with brain damage in the right hemisphere than in those suffering from left-hemisphere damage. This suggests the existence of specialized centers for this type of recognition and makes it difficult to ascribe the disorder to a simple alteration of the sensory function. On the other hand, the prominence of prosopagnosia in patients with right-hemisphere brain damage, although evident in the cases reported by Hhcaen and Angelergue~,~ cannot be accepted without reservation. Clinical observation of the symptom might be masked by concomitant aphasia in patients suffering from left-hemisphere damage. As one studies a number of the cases described in the literature, it becomes clear that many times prosopagnosia is discovered accidentally by the physician in the course of his interview with the patient without the latter mentioning it at all. Thus, the deficit could well be overlooked in the case of aphasic patients. 31 The basic defect in prosopagnosia is the incapacity to detect the individual character of objects or stimulus patterns within a single homogenous category from the standpoint of overall f ~ r m . ~ , ~ ~ It must be noted that these patients recognize a face to be a face and fre-