|Alternative Title||Prospection in Patients with Schizophrenia and Individuals with Social Anhedonia|
|Place of Conferral||中国科学院心理研究所|
|Keyword||前瞻功能 快感缺失 精神分裂症 脑成像 干预|
Anhedonia is a core feature of negative symptoms in schizophrenia and is often refractory to conventional treatment. The underlying neurobiological mechanism of anhedonia is still unclear. Schizophrenia patients have been shown to exhibit intact consummatory pleasure but deficits in anticipatory pleasure. As one of the subclinical populations along the schizophrenia spectrum, individuals with high social anhedonia (HSA) also exhibit diminished anticipatory pleasure. Investigating this subclinical sample not only benefits understanding of the underlying mechanisms of hedonic deficits along the psychotic continuum, but also facilitates early identification and intervention. Recent studies suggest that prospection could be one of the important processes underlying anticipatory pleasure. Prospection refers to the ability to simulated future episodes in one's mind, which is closely associated with emotion experience/regulation and motivation. Prospection is associated with activation of a core network including the prefrontal cortex (PFC), the medial temporal cortex and the posterior cingulate cortex, which overlaps with the Default Mode Network (DMN).
However, little is known about prospection in the schizophrenia spectrum. It is unclear how individuals with HSA prospect their future events and little is known about the relationship between prospection and pleasure experience in schizophrenia patients and individuals with HSA. No study has examined the neural correlates of prospection in these samples. In addition, although preliminary results have suggested prospection training may alleviate anhedonia in schizophrenia, further research is needed to improve the design of the intervention and test its effectiveness.
Study 1 investigated the behavioural performance of prospection and its correlation with anticipatory pleasure experience in schizophrenia patients and individuals with HSA. We found that both the groups of participants exhibited impairment in prospection, such as decreased richness of thought/emotion details and a low sense of pre-experience. Moreover, prospection variables were significantly correlated with anticipatory pleasure measured by self-report scales in both groups.
Study 2 examined grey matter (GM) correlates of prospection in schizophrenia patients and individuals with HSA. We found that prospection impairments of patients were associated with decreased GM volume in the PFC and the right hippocampus. Moreover, GM volume in the right lateral PFC was found to mediate the relationship between prospection and working memory in schizophrenia patients. There was a tendency that prospection was correlated with GM volume in the right temporal pole and the postcentral cortex in individuals with HSA, which needs further verification.
Study 3 investigated the association between prospection and resting-state functional connectivity of the DMN in schizophrenia patients and individuals with HSA. We found that altered functional connectivity of the DMN seeds was correlated with prospection performance in both groups of participants. Specifically, hypo-connectivity between the ventral medial PFC and the right superior temporal gyrus was associated with decreased richness of thought/emotion details in schizophrenia patients, while functional connectivity between the retrosplenial cortex and the fusiform gyrus was correlated with richness of event details in individuals with HSA.
Study 4 aimed to explore brain activation during positive prospection in HSA. We found reduced activation at the striatum, the precuneus cortex and the anterior cingulate cortex (ACC) when HSA individuals prospected positive future events (vs. neutral future events). Moreover, social interaction of positive episodes was correlated with engagement of the bilateral amygdala in the event elaboration stage in the social anhedonia group. In the control group, this prospection index was associated with activation in the ACC in the event elaboration stage.
In Study _5, we developed a group-based prospection intervention to alleviate anhedonia in patients with schizophrenia. Preliminary findings indicated that this intervention might be effective in alleviating anhedonia in schizophrenia patients. After the prospection training, an increase in self-report pleasure experience and objectively measured motivation, as well as improvement in negative symptoms were shown in schizophrenia patients.
In conclusion, we demonstrated that individuals with HSA exhibited not only prospection impairments at the behaviour level, but abnormal brain activations during positive prospection. We also investigated neural correlates of prospection in both schizophrenia patients and individuals with HSA and developed a prospection intervention which might be effective in alleviating anhedonia in schizophrenia patients.
|杨卓娅. 精神分裂症患者和高社会快感缺失个体的前瞻功能研究[D]. 中国科学院心理研究所. 中国科学院大学,2019.|
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