Performance during face processing differentiates schizophrenia patients with delusional misidentifications.

BACKGROUND: Delusional misidentification syndrome (DMS) is of considerable interest, but rarely diagnosed clinically. It is supposed to occur relatively frequently in schizophrenia, and to be related to the pathophysiology of face processing. Two antagonistic forms of DMS are the hypoidentification (Capgras) and hyperidentification (Fregoli) syndromes. We aimed to highlight differences between these subtypes using a face recognition memory task. METHODS: Twenty schizophrenia patients (10 with DMS) and 21 healthy controls memorized the images of unknown neutral faces (targets). After a 10-min interval, accuracy and reaction times were recorded during a recognition task consisting of targets (newly learned faces), as well as familiar and unfamiliar face images. The 10 DMS patients could be further subdivided into 6 patients with Fregoli syndrome and 4 with Capgras syndrome. RESULTS: Patients with DMS had longer reaction times than controls or patients without DMS (p < 0.001). Fregoli patients had longer reaction times (p < 0.001) and lower discrimination accuracy than Capgras patients (p = 0.019). These results were independent of other clinical variables. CONCLUSIONS: Face recognition differs between clinically identified subgroups of schizophrenia and between types of DMS. The results indicate independent pathophysiological mechanisms for Capgras (hypoidentification) and Fregoli (hyperidentification) syndromes in schizophrenia.

Encoding deficit during face processing within the right fusiform face area in schizophrenia.

Face processing is crucial to social interaction, but is impaired in schizophrenia patients, who experience delays in face recognition, difficulties identifying others, and misperceptions of affective content. The right fusiform face area plays an important role in the early stages of human face processing and thus may be affected in schizophrenia. The aim of the study was therefore to investigate whether face processing deficits are related to dysfunctions of the right fusiform face area in schizophrenia patients compared with controls. In a rapid, event-related functional magnetic resonance imaging (fMRI) design, we investigated the encoding of new faces, as well as the recognition of newly learned, famous, and unfamiliar faces, in 13 schizophrenia patients and 21 healthy controls. We applied region of interest analysis to each individual's right fusiform face area and tested for group differences. Controls displayed higher blood oxygenation level dependent (BOLD) activation during the memorization of faces that were later successfully recognized. In schizophrenia patients, this effect was not observed. During the recognition task, schizophrenia patients exhibited lower BOLD responses, less accuracy, and longer reaction times to famous and unfamiliar faces. Our results support the hypothesis that impaired face processing in schizophrenia is related to early-stage deficits during the encoding and recognition of faces.