The Journal of Neurology, Neurosurgery and Psychiatry carried a series of six articles on aspects of the neurological examination between 2002 and 2003 which, in some cases, highlighted how little is known about the scientific basis of certain routine clinical tests.¹ One such is the group of reflexes collectively known as “primitive reflexes”, reviewed by Schott and Rossor,² which include the grasp, snout, palmomental, and rooting reflexes. They are usually associated with neurodegenerative diseases causing dementia and, as the authors point out, loosely linked to frontal lobe pathology, but their exact physiological and anatomical substrates are poorly understood.

The well known tactile-evoked rooting reflex is the movement …