RT Journal Article SR Electronic T1 Engraved hexagons on an Ice Age ivory: a neurological perspective on an anthropological debate JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 1174 OP 1176 DO 10.1136/jnnp-2013-307044 VO 85 IS 10 A1 G D Schott YR 2014 UL http://jnnp.bmj.com/content/85/10/1174.abstract AB