Glabellar reflex

Glabellar reflex (also known as the "glabellar tap sign") (Glabella) is a primitive reflex. It is elicited by repetitive tapping on the forehead. Subjects blink in response to the first several taps. If the blinking persists, this is known as Myerson's sign and is abnormal and a sign of frontal release; it is often seen in people who have Parkinson's disease.