Impaired facial emotion recognition in a ketamine model of psychosis

Abstract

Objective: Social cognitive disabilities are a common feature in schizophrenia. Given the role of glutamatergic neurotransmission in schizophrenia-related cognitive impairments, we investigated the effects of the glutamatergic NMDA receptor antagonist ketamine on facial emotion recognition.

Methods: Eighteen healthy male subjects were tested on two occasions, one without medication and one after administration with subanesthetic doses of intravenous ketamine. Emotion recognition was examined using the Ekman 60 Faces Test. In addition, attention was measured by the Continuous Performance Test (CPT), and psychopathology was rated using the Psychotomimetic States Inventory (PSI).

Results: Ketamine produced a non-significant deterioration of global emotion recognition abilities. Specifically, the ability to correctly identify the facial expression of sadness was significantly reduced in the ketamine condition. These results were independent of psychotic symptoms and selective attention.

Conclusion: Our results point to the involvement of the glutamatergic system in the ability to recognize facial emotions.