A recent study published in Movement Disorders demonstrated that subthalamic nucleus stimulation modulates cognitive theory of mind in Parkinson’s disease. This work was performed by researchers from Dr. Ye Zheng’s Lab at the Institute of Neuroscience (ION) of the Center for Excellence in Brain Science and Intelligence Technology (CEBSIT) of the Chinese Academy of Sciences (CAS), and Professor Wu Jianjun at the Huashan Hospital, Fudan University. The study, using deep brain stimulation (DBS) and biophysical modeling, found that the subthalamic nucleus (STN) plays a crucial role in human empathy, especially in cognitive Theory of Mind (ToM).

The subthalamic nucleus (STN) is critical in the Theory of Mind (ToM). Deep brain stimulation (DBS) of the associative STN adversely affects cognitive ToM in Parkinson’s disease. Patients with mild cognitive impairment are susceptible to the negative effect of associative STN stimulation and, therefore, need attention in patient treatment and management. [IMAGE: ION/CEBSIT]

We live, survive, and develop in a society. Sophisticated social interaction skills are essential for adapting to society and realizing self-worth. Successful social interaction requires us to accurately infer the mental states of others, including their thoughts, intentions, and emotions, to understand and predict their behaviors. This human high cognitive function is empathy, also referred to as ToM. It encompasses cognitive components (inferring thoughts, thinking as others do) and affective components (inferring emotions, feeling as others feel). Patients with neurodegenerative diseases (e.g., Parkinson’s disease, PD) and neuropsychiatric disorders (e.g., autism spectrum disorder) often struggle to understand others’ thoughts or emotions accurately in social interactions, which leads to difficulties understanding their behaviors and reactions, and living and working normally.

Previous studies mainly focused on the role of the frontal cortex in ToM. It remains unclear how deep brain structures like the STN are engaged in ToM. To fill this gap, this study measured the ToM performance of 34 PD patients with DBS ON and OFF. It combined magnetic resonance imaging (MRI), computed tomography (CT), and biophysical modeling techniques to reconstruct the stimulation site and estimate the volumes of tissue activated. The study revealed that the associative STN plays a causal role in ToM. Stimulation of the associative STN impaired the cognitive component of ToM, without changing the affective component of ToM. Patients with greater associative STN stimulation in the DBS ON state, and especially those with mild cognitive decline, tended to infer others’ thoughts more slowly.

This study, for the first time, mapped ToM to the associative STN, demonstrating the role of the associative STN in understanding others’ thoughts. It not only opens a new window on the research of human social cognitive functions like empathy but also provides clinical insights for patient treatment and management.

This work, entitled “Subthalamic Nucleus Stimulation Modulates Cognitive Theory of Mind in Parkinson’s Disease”, has been published online in Movement Disorders on May 2, 2024. Ms. Xiao Haoyun at CAS’s ION/CEBSIT, and Dr. Lang Liqin at Huashan Hospital are the co-first authors. Dr. Ye Zheng at CAS’s ION/CEBSIT, and Professor Wu Jianjun at Huashan Hospital are the co-corresponding authors. 

For more information, please contact:

Dr. Ye Zheng

E-mail: yez@ion.ac.cn

Institute of Neuroscience,

Center for Excellence in Brain Science and Intelligence Technology,

Chinese Academy of Sciences

Source: Institute of Neuroscience,

Center for Excellence in Brain Science and Intelligence Technology,

Chinese Academy of Sciences