Anterior cingulate cortex activation is related to learning potential on the WCST in schizophrenia patients.

The remediation of executive function in patients with schizophrenia is important in rehabilitation because these skills affect the patient's capacity to function in the community. There is evidence that instructional techniques can improve deficits in the Wisconsin Card Sorting Test (WCST) in some schizophrenia patients. We used a standard test/training phase/standard test format of the WCST to classify 36 schizophrenia patients as high-achievers, learners or non-retainers. All healthy controls performed as high-achievers. An event-related fMRI design assessed neural activation patterns during post-training WCST performance. Patients showed a linear trend between set-shifting related activation in the anterior cingulate cortex and learning potential, i.e. increased activation in high-achievers, a trend for increased activation in learners, and no activation in non-retainers compared to controls. In addition, activation in the temporoparietal cortex was highest in patients classified as learners, whereas in non-retainers activation was increased in the inferior frontal gyrus compared to controls and high-achieving patients. These results emphasize the relevance of the ACC's neural integrity in learning set-shifting strategies for patients with schizophrenia. Also, our results support the hypothesis that compensatory neural activation in patients with schizophrenia helps them to catch up with healthy controls on cognitive tasks.

Theory of mind in patients with schizophrenia: is mentalizing delayed?

OBJECTIVE: Functional imaging studies have used numerous neurocognitive designs to investigate brain activation during theory of mind (ToM) tasks in patients with schizophrenia. The majority of studies asks participants to retrospectively attribute mental states to others. We used a novel animated task to investigate implicit mentalizing online. Because behavioral studies have revealed slower ToM performance reaction times in patients with schizophrenia, we hypothesized that time would influence functional MRI (fMRI) activation patterns also. METHODS: We applied the "Moving Shapes" paradigm, which involves two interacting triangles, to a functional MRI block design and investigated the neural activation patterns of 15 patients with schizophrenia and 14 healthy controls. We additionally analyzed the first and second halves of each video separately to assess time-related differences. RESULTS: Overall, patients with schizophrenia showed increased activation in the inferior and middle frontal gyri, the superior temporal gyrus, the precuneus and the cerebellum compared with controls during ToM versus non-ToM videos. Most importantly, patients with schizophrenia had predominantly increased activation in ToM-related brain areas during the second half of the ToM paradigm, whereas the activation in areas of the ToM-network in healthy controls occurred during the first half of the presentation. CONCLUSIONS: Our results confirm recent findings of significantly stronger neural activations that encompass the fronto-temporo-parietal cerebral areas in patients with schizophrenia compared with controls during ToM tasks. The observation of slower cognitive processing in patients with schizophrenia during mentalizing might explain some of the contradictory imaging findings in these patients and have implications for cognitive remediation.

Theory of Mind in first-episode schizophrenia patients: correlations with cognition and personality traits.

INTRODUCTION: There is substantial evidence for Theory of Mind (ToM) deficits in patients with schizophrenia. Many psychotic symptoms may best be understood in light of an impaired capacity to infer one's own and other persons' mental states and to relate those to executing behavior. The aim of our study was to investigate ToM abilities in first-episode schizophrenia patients and to analyze them in relation to neuropsychological and psychopathological functioning. MATERIALS AND METHODS: A modified Moving Shapes paradigm was used to assess ToM abilities in 23 first-episode patients with schizophrenia and 23 matched healthy controls. Participants had to describe animated triangles which moved (1) randomly, (2) goal-directed, or (3) in complex, socially interactive ways (ToM video sequences). Neuropsychological functioning, psychopathology, autistic and alexithymic features as well as empathetic abilities were correlated with ToM performance. RESULTS: Compared to healthy controls, first-episode schizophrenia patients gave more incorrect descriptions and used less ToM-related vocabulary when responding to socially complex ToM video sequences. No group differences were revealed for videos with random movements. ToM abilities correlated significantly with positive symptoms, reasoning, verbal memory performance and verbal IQ, but not with empathetic abilities or autistic and alexithymic features. When controlling for reasoning, verbal memory performance and verbal IQ, the correctness of video descriptions was still significantly worse in schizophrenia patients. DISCUSSION: The results of our study in first-episode schizophrenia patients underline recent findings on ToM deficits in the early course of schizophrenia. Only a moderate influence of neurocognitive deficits on ToM performance was observed. Impairment in ToM abilities seems to be predominantly independent of clinical state, alexithymia and empathy.