Sucking reflexes appear in positive infants from 0 to 3 months of age, and when something is placed in the infant’s mouth, the infant will suck; after 6 weeks, the breathing, sucking, and swallowing reflexes coordinate with each other, and feeding becomes more efficient. Newborns have not yet developed their chewing function and can only take in mother’s milk or formula through sucking action. Therefore, when objects such as cotton swabs or fingertips are placed in the infant’s mouth, the infant will naturally appear to suck. It disappears on its own 3-4 months after birth and is gradually replaced by active feeding movements. However, during sleep and on some other occasions, the infant still shows spontaneous sucking movements for a period of time. If the sucking reflex disappears or is significantly weakened in the neonatal period, it suggests an intracerebral lesion; if it is hyperactive, it is a sign of hunger; its presence after 1 year of age suggests cortical dysfunction. So, what causes a positive sucking reflex? The presence of a positive sucking reflex in non-childhood is most often seen in frontal lobe lesions and pseudobulbar palsy. Frontal lobe lesions often cause symptoms:significant memory impairment up to varying degrees of dementia. Damage to the anterior frontal lobe manifests as mental, emotional, personality, behavioral and intellectual disturbances. Posterior frontal lobe lesions cause contralateral motor deficits, irritative frontal lobe floor symptoms cause vegetative dysfunction, destructive lesions cause mental disturbances, anger and lignocardia, and anterior cingulate lesions cause pupillary dilation, bradycardia, and slowed respiration.