Dissociation between the processing of affective and nonaffective faces: a case study.

In this report we describe a patient with a right-hemisphere lesion who showed a dissociation between the processing of affective and nonaffective faces. Although he performed normally on neutral facial tasks, he was impaired in naming and pointing to facial expressions. This dissociation is discussed in terms of four possible mechanisms: (a) a high-level visuoconfigurational defect; (b) an associative agnosic type of defect for facial expressions; (c) a specific "activation" defect; and (d) a visual-verbal disconnection resulting in an anomic type of defect for facial expressions.