Primitive reflex Persistent asymmetrical tonic neck reflex 2019-06-12T10:56:12Z Persistence beyond the normal age (roughly the first half of the first year of life) of the asymmetric tonic neck reflex (ATNR), which is an easily elicited primitive reflex in the immediate newborn period. The ATNR refers to the phenomenon whereby when the face of an infant is turned to one side, the ipsilateral arm and leg extend and the contralateral arm and leg flex. This posture has been compared to a typical posture of fencers. Persistent fencer's reflex Tonic neck reflex asymmetrical and persistent