Face recognition within the reach of neurobiology and beyond it.

Recognition of faces and facial expression is an important component of non-verbal human social behaviour. It is believed to be older phylogenetically than verbal communication in man. Presumably we share basic brain mechanisms of face and mimic recognition with other primates. While palaeoanthropological artifacts indicate the existence of artistic creation in the sculptures and paintings of humans since the upper palaeolithic age (about 30,000 years ago), artistic interest in individual human faces is a rather recent development of mankind, which appeared about 4,500 years ago. Human face and mimic recognition as mimic expression is characterized by some left-right asymmetry, indicating a corresponding discrepancy in the contribution of the left and the right cortical hemisphere to these functions. This opinion is not only supported by data from neuropsychological experiments in normals applying tachistoscopic stimulation to the left or the right visual half-field, but also by the symptoms observed in patients suffering from unilateral cortical lesions. Face and mimic recognition is impaired by left hemisphere or right hemisphere lesions, but for certain aspects a higher contribution is accredited to the right hemisphere by the majority of the investigators. A side bias is also evident in portrait paintings, but this has slowly changed over the last 500 years. The symptom of prosopagnosia, which in rare cases exists in the isolated form, depends not only on the sites of the brain lesion (preferably bilateral, occipitotemporal), but also on the individual training and experience of the patient. Clinical observations as well as the data obtained in microelectrode studies of monkey temporal lobe support the existence of face-specific cortical areas.(ABSTRACT TRUNCATED AT 250 WORDS)