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Patients with schizophrenia have difficulty recognising the emotion that corresponds to a given facial expression. According to signal detection theory, two separate processes are involved in facial emotion perception: a sensory process (measured by sensitivity which is the ability to distinguish one facial emotion from another facial emotion) and a cognitive decision process (measured by response criterion which is the tendency to judge a facial emotion as a particular emotion). It is uncertain whether facial emotion recognition deficits in schizophrenia are primarily due to impaired sensitivity or response bias. In this study, we hypothesised that individuals with schizophrenia would have both diminished sensitivity and different response criteria in facial emotion recognition across different emotions compared with healthy controls. Twenty-five individuals with a DSM-IV diagnosis of schizophrenia were compared with age and IQ matched healthy controls. Participants performed a "yes-no" task by indicating whether the 88 Ekman faces shown briefly expressed one of the target emotions in three randomly ordered runs (happy, sad and fear). Sensitivity and response criteria for facial emotion recognition was calculated as d-prime and In(beta) respectively using signal detection theory. Patients with schizophrenia showed diminished sensitivity (d-prime) in recognising happy faces, but not faces that expressed fear or sadness. By contrast, patients exhibited a significantly less strict response criteria (In(beta)) in recognising fearful and sad faces. Our results suggest that patients with schizophrenia have a specific deficit in recognising happy faces, whereas they were more inclined to attribute any facial emotion as fearful or sad.

BackgroundThe ability to appreciate humour is essential to successful human interactions. In this study, we hypothesized that individuals with schizophrenia would have diminished ability to recognize and appreciate humour. The relationship between humour experience and clinical symptoms, cognitive and social functioning was examined.MethodThirty patients with a DSM-IV diagnosis of schizophrenia were compared with 30 age-, gender-, IQ- and ethnicity-matched healthy controls. Humour recognition was measured by identification of humorous moments in four silent slapstick comedy film clips and calculated as d-prime (d′) according to signal detection theory. Humour appreciation was measured by self-report mood state and funniness ratings. Patients were assessed for clinical symptoms, theory of mind ability, executive function [using the Wisconsin Card Sorting Test (WCST)] and social functioning [using the Life Skills Profile (LSP)].ResultsPatient and control groups did not differ in the funniness ratings they attributed to the video clips. Patients with schizophrenia had a lower d′ (humour) compared to the controls, after controlling for (1) the performance of a baseline recognition task with a non-humorous video clip and (2) severity of depressive symptoms. In patients, d′ (humour) had significant negative correlation with delusion and depression scores, the perseverative error score of the WCST and the total scores of the LSP.ConclusionsCompared with controls, patients with schizophrenia were less sensitive at detecting humour but similarly able to appreciate humour. The degree of humour recognition difficulty may be associated with the extent of executive dysfunction and thus contribute to the psychosocial impairment in patients with schizophrenia.

We asked 24 schizophrenia patients and 24 healthy comparison subjects to complete a parametric working memory version of the continuous performance test. Patients exhibited a relatively rapid performance decline with increasing working memory demands. We suggest an interaction between sustained attention and working memory abnormalities in schizophrenia.

Our ability to interact physically with objects in the external world critically depends on temporal coupling between perception and movement (sensorimotor timing) and swift behavioral adjustment to changes in the environment (error correction). In this study, we investigated the neural correlates of the correction of subliminal and supraliminal phase shifts during a sensorimotor synchronization task. In particular, we focused on the role of the cerebellum because this structure has been shown to play a role in both motor timing and error correction. Experiment 1 used fMRI to show that the right cerebellar dentate nucleus and primary motor and sensory cortices were activated during regular timing and during the correction of subliminal errors. The correction of supraliminal phase shifts led to additional activations in the left cerebellum and right inferior parietal and frontal areas. Furthermore, a psychophysiological interaction analysis revealed that supraliminal error correction was associated with enhanced connectivity of the left cerebellum with frontal, auditory, and sensory cortices and with the right cerebellum. Experiment 2 showed that suppression of the left but not the right cerebellum with theta burst TMS significantly affected supraliminal error correction. These findings provide evidence that the left lateral cerebellum is essential for supraliminal error correction during sensorimotor synchronization.