Neural activities of theory of mind in individuals with schizophrenia: A meta-analysis of fMRI studies

Neuroimaging evidence regarding the activation of brain regions associated with the Theory of Mind (ToM) in individuals with schizophrenia remains inconsistent. Some studies identified decreased activation in various regions, such as the insula, frontal gyrus, superior temporal gyrus, and precuneus, during ToM tasks in schizophrenia compared with healthy people; others reported increased activation in these areas. Additionally, neural activity of individuals with schizophrenia compared with individuals at risk of schizophrenia has not been uniformly demonstrated. This study selected 44 studies that employed functional magnetic resonance imaging (fMRI) technology to explore ToM in individuals with schizophrenia, healthy controls, and at-risk for schizophrenia groups, adopted an Activation Likelihood Estimation (ALE) meta-analysis to calculate the brain activation regions in the three groups, and further analyzed their differences. Results revealed deficiencies in activation within the mentalization network and mirror neuron system related to ToM processes in individuals with schizophrenia. However, stronger convergent activation in the right middle temporal and superior temporal gyrus indicated compensatory activity in these processes. We also observed stronger convergent activation in the left precuneus and frontal gyrus in individuals at risk of schizophrenia during the ToM processes. This indicated that at-risk individuals also had compensatory activity in ToM processes. These findings shed light on the neural activity characteristics of ToM in individuals with and at risk of schizophrenia.