[Neural bases of perception and recognition of faces]

Abstract

Objective: To analyze the neural bases of perception and the recognition of faces. First of all we consider the concept of functional hemisphere specialization; then we look at the results obtained with regard to the neuroanatomy of processing faces and finally refer to the disorders of recognition of faces in humans. For this we review the clinical evidence obtained from the neuropsychological studies of prosopagnostic patients and the data derived from psychophysiological experiments done using intracranial recordings of nonhuman primates.

Development: The agreement between the results analysed allows us conclude that in both cerebral hemispheres there are neural mechanisms specialized in the perception and recognition of faces, and in particular the ventral and posterior regions of the occipito-temporal cortex play a decisive part in these processes. Similarly experimental findings in nonhuman primates permits explanation of the neural nature of certain neuropsychological disorders seen in man, such as the case of the dissociation between disorders of the recognition of facial identity and disorders of recognition of emotional expression, and also dissociation between the difficulty in recognizing familiar faces and difficulty in recognizing non-familiar faces.

Conclusion: The use of modern neuroimaging techniques and electrophysiological studies using evoked potentials are necessary for greater understanding of these and other disorders related to processing facial information.