To Explore the Neural Processing Mechanism of Cerebellum Involved in Facial Expression Recognition Based on Transcranial Magnetic Stimulation

Experiment 1: Utilizing a transcranial magnetic stimulation-electroencephalography/functional near-infrared spectroscopy system, the investigators aim to determine whether transcranial magnetic stimulation of the cerebellum can alter neural oscillations and blood flow changes in the prefrontal cortex. The investigators will recruit 80 healthy volunteers and 80 stroke patients with middle cerebral artery infarction, each meeting the inclusion criteria. Twenty healthy volunteers and twenty patients will be randomly selected to receive a single-pulse transcranial magnetic stimulation (TMS) to the cerebellar vermis. The investigators will record cerebellar transcranial evoked potentials (TEP) in the EEG to assess cerebellar cortical excitability and inhibition and evaluate individuals using functional near-infrared spectroscopy to analyze changes in prefrontal blood flow and brain networks. The other 40 healthy volunteers and 40 patients will receive a single-pulse TMS to the right or left cerebellum, and similar assessments will be made. The remaining 20 healthy volunteers and 20 patients will receive a sham iTBS, with similar assessments.

Experiment 2: Through a facial expression recognition task, this experiment aims to clarify the cerebellum's increased perception of negative emotions, thereby achieving a rebalance from "controlled" to "automatic" regulation of negative emotions, ultimately playing a role in "automatic" emotional adjustment. The 80 healthy volunteers from Experiment 1 will be equally divided into four groups based on stimulation site: the cerebellar vermis; the right cerebellum; the left cerebellum; the sham stimulation. Each group will perform the facial expression recognition task during the TMS stimulation. The investigators will collect functional near-infrared spectroscopy and task-based EEG data from the participants during stimulation while also recording their response times, accuracy rates, and completion conditions, including their tolerance of the experiment and any adverse events.