Abstract
The brain has at least two roles as an organ : One is to put a person in an adequate environment, the other is to communicate verbally.
1) Face of Street (town)
A scenary such as street is an important environmental stimulus and its recognition indicates a lot to the recognition-behavior of man. Identifying the face of street is necessary in order to put the self in an adequate environment. The patient of this kind tends to consider his house as not his own and thinks the familiar street as strange. This phenomenon is similar to the prosopagnosia. Thus the agnosia for scene consists of the impossibility to recognize the face of street. Common MRI lesion in our 6 cases lies in the right parahippocampal gyrus.
2) Face of Person (human-being)
Human face is also an important enviromental stimulus. Identifying human face precisely is very important in putting one in an adequate environment and in pursuing a social life. The failure to recognize the human face is called prosopagnosia. The lesion lies in the right fusiform and lingual gyri just posterior to the one which causes the scien agnosia.
The pathophysiology for both the scien agnosia and the prosopagnosia seams to be the disturbance in the right occipito-temporal lobe-hippocampus system. Thus the system of the postero-inferior part of the right hemisphere and hippocampus plays a major role in the recognition of the street and person.
3) Recognition of facial expression
The disturbance of recognition of facial expression doesn't occur in most of the patients suffering from prosopagnosia. The lesions which reveal the disturbance of recognition of facial expression include the basal ganglia and amygdala. Facial expression is one of the ways to communicate non-verbally and its recognition is another role of the brain.
People use the different brain structure in identifying the human face from in understanding the facial expression.
