Emotional processing in schizophrenia: neurobehavioral probes in relation to psychopathology

The application of neurobehavioral methods in functional neuroimaging can provide useful information on the neurobiology of schizophrenia. This process can be enhanced by using a standard set of procedures to construct 'neurobehavioral probes' which are suitable for functional imaging and provide reliable measures discriminating patients from healthy controls. While such probes are available for cognitive tasks, none has been applied to study emotional processing in schizophrenia. We examined emotional discrimination and experience probes and correlated performance with cognitive and clinical measures. Emotion discrimination tasks and mood induction procedures with happy, sad, and neutral facial expressions were administered to 40 patients with schizophrenia. Neuropsychological testing assessed intellectual, attention, abstraction-flexibility, memory, language, spatial, and sensory-motor functions. Emotional performance was compared to a group of 40 normal subjects. Performance for face discrimination was impaired in patients. There was specific impairment in discrimination of happy expressions. Mood induction was effective in both groups, but diminished in patients, especially for happiness. Poorer performance in emotion discrimination correlated with severity of negative symptoms and bizarre behavior. Hallucinations were associated with more pronounced mood induction effects. Emotion discrimination was also correlated with abstraction, memory, language and spatial tasks, while mood induction effects showed no such associations. Thus, the impairment in discriminating and experiencing valence-specific emotions in schizophrenia relates to symptomatology and neuropsychological functioning. The results encourage the use of the emotion discrimination task and the mood induction procedure as neurobehavioral probes in physiologic neuroimaging studies for investigating the neural substrates of emotion.