Neural correlates of prospection impairments in schizophrenia: Evidence from voxel-based morphometry analysis

Prospection deficits in patients with first-episode schizophrenia: a cross-sectional comparative study

Prospection refers to the ability to simulate and pre-experience future events. Schizophrenia patients have difficulty in anticipating pleasure in future events, but previous studies examined prospection deficits in chronic schizophrenia patients. This study aimed to investigate prospection deficits in first-episode schizophrenia patients. Thirty first-episode schizophrenia patients and 31 healthy controls completed the Affective Prospection Task, which utilized pictorial cues to involve positive, neutral and negative prospection. Participants' ratings regarding the phenomenal characteristics of their prospected events were collected, and their prospected narratives were coded using a valid scoring manual. We also assessed intelligence, working memory and logical memory. The results showed, in all participants, valence of the cues significantly influenced participants' sense of pre-experience, temporal distance, emotion experience, vividness and participation of the prospected events, as well as the richness of sensory details. The two groups did not differ in self-report phenomenal characteristics of their prospected events. For coded characteristics, schizophrenia patients' prospected narratives were less rich in thought/emotion than controls, even after controlling for intelligence and memory deficits. We extended empirical evidence for prospection deficits from chronic schizophrenia samples to first-episode schizophrenia patients.

Common and specific patterns of functional and structural brain alterations in schizophrenia and bipolar disorder: a multimodal voxel-based meta-analysis

BACKGROUND

Schizophrenia and bipolar disorder have been linked to alterations in the functional activity and grey matter volume of some brain areas, reflected in impaired regional homogeneity and aberrant voxel-based morphometry. However, because of variable findings and methods used across studies, identifying patterns of brain alteration in schizophrenia and bipolar disorder has been difficult.

METHODS

We conducted a meta-analysis of differences in regional homogeneity and voxel-based morphometry between patients and healthy controls for schizophrenia and bipolar disorder separately, using seed-based d mapping.

RESULTS

We included 45 publications on regional homogeneity (26 in schizophrenia and 19 in bipolar disorder) and 190 publications on voxel-based morphometry (120 in schizophrenia and 70 in bipolar disorder). Patients with schizophrenia showed increased regional homogeneity in the frontal cortex and striatum and the supplementary motor area; they showed decreased regional homogeneity in the insula, primary sensory cortex (visual and auditory cortices) and sensorimotor cortex. Patients with bipolar disorder showed increased regional homogeneity in the frontal cortex and striatum; they showed decreased regional homogeneity in the insula. Patients with schizophrenia showed decreased grey matter volume in the superior temporal gyrus, inferior frontal gyrus, cingulate cortex and cerebellum. Patients with bipolar disorder showed decreased grey matter volume in the insula, cingulate cortex, frontal cortex and thalamus. Overlap analysis showed that patients with schizophrenia displayed decreased regional homogeneity and grey matter volume in the left insula and left superior temporal gyrus; patients with bipolar disorder displayed decreased regional homogeneity and grey matter volume in the left insula.

LIMITATIONS

The small sample size for our subgroup analysis (unmedicated versus medicated patients and substantial heterogeneity in the results for some regions could limit the interpretability and generalizability of the results.

CONCLUSION

Patients with schizophrenia and bipolar disorder shared a common pattern of regional functional and structural alterations in the insula and frontal cortex. Patients with schizophrenia showed more widespread functional and structural impairment, most prominently in the primary sensory motor areas.

Cognitive and Social Cognitive Self-assessment in Autistic Adults

An aspect of metacognition associated with broader functional abilities in several clinical conditions, but previously unexamined in autism, is self-assessment (i.e., the ability to accurately self-evaluate one's own performance). We compared self-assessment between 37 autistic adults without intellectual disability to 39 non-autistic (NA) controls on a series of three general cognitive and three social cognitive tasks. Whereas autistic adults and NA adults did not differ in their self-assessment accuracy on general cognitive tasks, they did on social cognitive tasks, with autistic adults demonstrating lower accuracy. The direction of their inaccuracy was variable (i.e., both over and underestimation), and self-assessment was largely unrelated to their level of social functioning. Over versus underestimation may have different functional implications, and warrants future investigation.

Enhanced Prefrontal Regional Homogeneity and Its Correlations With Cognitive Dysfunction/Psychopathology in Patients With First-Diagnosed and Drug-Naive Schizophrenia

Background: Schizophrenia, regarded as a neurodevelopmental disorder, is characterized by positive symptoms, negative symptoms, and cognitive dysfunction. Investigating the spontaneous brain activity in patients with schizophrenia can help us understand the underlying pathophysiologic mechanism of schizophrenia. However, results concerning abnormal neural activities and their correlations with cognitive dysfunction/psychopathology of patients with schizophrenia were inconsistent. Methods: We recruited 57 first-diagnosed and drug-naive patients with schizophrenia and 50 matched healthy controls underwent magnetic resonance imaging. The Positive and Negative Syndrome Scale (PANSS) and the MATRICS Consensus Cognitive Battery were used to assess the psychopathology/cognitive dysfunction. Regional homogeneity (ReHo) was used to explore neural activities. Correlation analyses were calculated between abnormal ReHo values and PANSS scores/standardized cognitive scores. Lastly, support vector machine analyses were conducted to evaluate the accuracy of abnormal ReHo values in distinguishing patients with schizophrenia from healthy controls. Results: Patients with schizophrenia showed cognitive dysfunction, and increased ReHo values in the right gyrus rectus, right inferior frontal gyrus/insula and left inferior frontal gyrus/insula compared with those of healthy controls. The ReHo values in the right inferior frontal gyrus/insula were positively correlated with negative symptom scores and negatively correlated with Hopkins verbal learning test-revised/verbal learning. Our results showed that the combination of increased ReHo values in the left inferior frontal gyrus/insula and right gyrus rectus had 78.5% (84/107) accuracy, 85.96% (49/57) sensitivity, and 70.00% specificity, which were higher than other combinations. Conclusions: Hyperactivities were primarily located in the prefrontal regions, and increased ReHo values in the right inferior frontal gyrus/insula might reflect the severity of negative symptoms and verbal learning abilities. The combined increases of ReHo values in these regions might be an underlying biomarker in differentiating patients with schizophrenia from healthy controls.