The frontal release signs refer to a group of reflexive behaviors, controlled by the basal ganglia, which are normally evident only in earliest infancy. Examples of these behaviors include rooting (turning the face toward an object if it touches the cheek near the mouth) and puckering of the lips in response to touch of the skin above the upper lip. These instinctual behaviors promote nursing behavior in an infant.

The palmar grasp reflex helps an infant hold onto its mother. In this reaction, the infant grasps at anything that strokes its palm. The Babinski reflex, in which the foot arches away from tactile stimulation on the sole of the foot, is another of these early reflexes. With development of the frontal lobe, these crude automatic behaviors are suppressed. When there is damage to the frontal lobe in adulthood, however, these early reflexes may re-emerge. The presence of frontal release signs in adulthood, therefore, is a sign of significant brain damage.