Humor processing is a complex social cognition with high-order emotional experience unique to human beings. Its underlying cognitive process consists of expectation, incongruity detection, resolution and appreciation.

Drs. HUANG Jia and Raymond Chan from the Institute of Psychology of the Chinese Academy of Sciences have previously found that individuals with high levels of social anhedonia exhibited deficits in humor processing. Compared to the controls, individuals with high levels of social anhedonia exhibited higher threshold of humor appreciation instead of humor signal detection. Although patients with schizophrenia show both poorer humor signal detection and appreciation compared to controls, the neural mechanism of these deficits remains unclear.

To address this issue, Drs. HUANG Jia and Raymond Chan, along with collaborators from Peking University Sixth Hospital, conducted a further study to examine neural mechanism of humor processing in patients with first-episode schizophrenia.

This study was published in Asian Journal of Psychiatry on Dec. 23. 

They used a fMRI verbal humor paradigm to 40 patients with first-episode schizophrenia and 31 healthy controls to evaluate their humor processing. The task comprised 96 stories, half with a funny punch-line condition and half with an unfunny condition. The participants had to indicate whether the story was funny or not by pressing the keys.

Signal detection analysis showed that patients with first-episode schizophrenia exhibited significantly lower hit rate and sensitivity of humor signals (d'). At the neural level, patients with first-episode schizophrenia exhibited hypo-activation in ventral medial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC), but hyper-activation in middle temporal gyrus (MTG) and superior temporal gyrus (STG) compared to controls.

In addition, brain activations in vmPFC and ACC were positively associated with d' and β values, while activation in STG was positively associated with β values in first-episode schizophrenia patients.

Taken together, these findings suggest the reduced sensitivity of patients with first-episode schizophrenia towards humor signals. Hypo-activations in frontal regions and hyper-activation in temporal regions were associated with the humor processing deficits.

These underlying neural substrates of humor processing deficits in first-episode schizophrenia may represent important putative neural mechanism and potential intervention targets for schizophrenia spectrum disorders.

These results will provide new insights into understanding complex social cognition in psychiatric disorders.