Laterality effects in normal subjects' recognition of familiar faces, voices and names. Perceptual and representational components.

A growing body of evidence suggests that a different hemispheric specialization may exist for different modalities of person identification, with a prevalent right lateralization of the sensory-motor systems allowing face and voice recognition and a prevalent left lateralization of the name recognition system. Data supporting this claim concern, however, much more disorders of familiar people recognition observed in patients with focal brain lesions than results of experimental studies conducted in normal subjects. These last data are sparse and in part controversial, but are important from the theoretical point of view, because it is not clear if hemispheric asymmetries in the recognition of faces, voices and names are limited to their perceptual processing, or also extend to the domain of their cortical representations. The present review has tried to clarify this issues, taking into account investigations that have evaluated in normal subjects laterality effects in recognition of familiar names, faces and voices, by means of behavioural, neurophysiological and neuroimaging techniques. Results of this survey indicate that: (a) recognition of familiar faces and voices show a prevalent right lateralization, whereas recognition of familiar names is lateralized to the left hemisphere; (b) the right hemisphere prevalence is greater in tasks involving familiar than unfamiliar faces and voices, and the left hemisphere superiority is greater in the recognition of familiar than unfamiliar names. Taken together, these data suggest that hemispheric asymmetries in the recognition of faces, voices and names are not limited to their perceptual processing, but also extend to the domain of their cortical representations.