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 spectrum of schizophrenia, 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. On the other hand, 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).
Dr. Raymond Chan from the Neuropsychology and Applied Cognitive Neuroscience (NACN) Laboratory, CAS Key Laboratory of Mental Health, Institute of Psychology and his international collaborators have conducted a study to examine specifically the relationship between functional connectivity of the DMN and prospection in these clinical and subclinical samples. They recruited 40 schizophrenia patients and 29 healthy controls, while 31 individuals with social anhedonia (SocAhn) and 28 controls participated for the study. All participants were asked to complete a prospection task and underwent resting-state functional MRI scans. Functional connectivity between the identified 11 regions of interest and whole brain voxels were calculated and compared between groups, i.e., schizophrenia vs. control and SocAhn vs. control.
Their results showed that hyper-connectivity and hypo-connectivity were observed at the medial temporal lobe (MTL) subsystem of the DMN in patients with schizophrenia. Decreased connectivity between the ventral medial prefrontal cortex (vMPFC) and the right superior temporal gyrus (rSTG) was correlated with poor thought/emotion details in prospection in this clinical group. On the other hand, decreased connectivity between the retrosplenial cortex (Rsp), a region of the MTL subsystem, and the right fusiform gyrus, was observed in individuals with SocAhn and this was correlated with their prospection performance.
Taken together, we found altered functional connectivity of the MTL subsystem in schizophrenia patients and individuals with SocAhn. The most interesting and important finding was the relationship we found between decreased functional connectivity and prospection impairment in schizophrenia patients. The altered functional connectivity was also associated with prospection in individuals with SocAhn.
The study was supported by the National Science Fund China, National Key Research and Development Programme, the Beijing Municipal Science & Technology Commission Grant, and the Beijing Training Project for the Leading Talents in Science and Technology.
This study is now published online in Progress in Neuropsychopharmacology & Biological Psychiatry.
Yang, Z. Y., Zhang, R. T., Li, Y., Wang, Y., Wang, Y. M., Wang, S. K., ？ngür, D., Cheung, E. F. C., Chan, R. C. K.* (2019). Functional connectivity of the default mod network is associated with prospection in schizophrenia patients and individuals with social anhedonia. Progress in Neuropsychopharmacology and Biological Psychiatry, 92, 412-420.
Institute of Psychology