ORTHOGRAPHIC HALLUCINATION

The term orthographic hallucination is indebted to the Greek wordsorthos(straight) andgraphein(to draw, to write, to etch, to paint). It translates loosely as 'a hallucination involving letters and spelling'. The term is used to denote a "visual hallucination consisting of written letters, words, or musical notes. It has been suggested that the mediation of orthographic hallucinations is associated primarily with aberrant neuronal activity in the visual word form area, located in the ventral temporal lobe. When orthographic hallucinations present in the form of a written text they are referred to as " visual text hallucinations. When these convey an incentive or command, they may be called " visual command hallucinations.

ffytche, D.H., Lappin, J.M., Philpot, M. (2004). Visual command hallucinations in a patient with pure alexia.Journal of Neurology, Neuro-surgery and Psychiatry, 75, 80-86.