The cortical projection areas for somatosensation are mainly located in the postcentral gyrus, and disease of the postcentral gyrus presents with symptoms such as the absence of pain and temperature sensation in the skin of the contralateral body. The somatosensory projection areas are in the posterior central gyrus of the cerebral cortex. The postcentral gyrus is the brain gyrus between the central sulcus and the postcentral sulcus, and this area belongs to the first sensory area, which is the highest level center of somatosensory sensation, and plays a role in the processing of tactile neural information of the limbs. If the nerve cells in the posterior gyrus of the brain are damaged due to cerebral infarction, cerebral hemorrhage, or brain tumor, the skin on the opposite side of the limb will show a decrease in sensitivity to touch, pain, and temperature. Once you find abnormal sensation on one side of the limb, you should consult a doctor in time, follow the doctor’s instructions for examination and treatment, and don’t take it lightly and miss the condition.