RETROACTIVE HALLUCINATION

The term retroactive hallucination is indebted to the Latin wordsretro(backwards) andagere(to do, to act). It translates roughly as 'a hallucination placed into one's memory'. The termhallucination rétroactivewas coined in or shortly before 1886 by the French internist and hypnotist Hippolyte Bernheim (1837-1919) to denote a percept suggested to a hypnotized subject, which is subsequently accepted, and incorporated into the subject's memory. Bernheim gives the example of a woman, referred to as Marie G., to whom he made the suggestion that she had been out of bed four times in a row the previous night and that she had fallen and hurt her nose. When questioned, Marie G. would not only repeat what had been suggested to her, but would insist that she had a clear memory of walking around at night and seeing all the other patients in the hospital asleep. As noted by the Swiss psychiatrist, hypnotist, and entomologist August Forel (1848-1931), it is disputable whether such 'images' should be allowed to count as hallucinations, even ifone accepts that the hypnotized subject can actually picture the suggested scene. As retrieved memories seldom take the form of " reperceptions, and nothing in Bernheim's text indicates that this was so in the case of Marie G., to designate these false memories as hallucinations would mean stretching the definition of hallucinations beyond its rightful limits.

Bernheim, H. (1886).De la suggestion et de ses applications à la thérapeutique. Paris: Octave Doin.

Forel, A. (1895).Der Hypnotismus. Dritte verbesserte Auflage. Stuttgart: Verlag ven Ferdinand Enke.