Antoine Ritti (1844-1920), forgotten alienist and innovative theorist on the pathophysiology of hallucinations

Antoine Ritti (1844-1920), now forgotten, was an “alienist” or psychiatrist who formulated a theory of hallucination based on thalamic dysfunction, as described in his thesis defended in 1874. Ritti was a student of Jules Luys and used the anatomical-functional discoveries of his teacher to explain that an automatic activity in the thalamus, by stimulating the cortex without reception of sensory information, created autonomous representations, perceived by the patient but not by his entourage, a process occurring spontaneously to some degree. Hence, Ritti seems the first author to introduce the concept of sensory deprivation and release of subcortical function into the pathophysiology of hallucinations. This innovative theory, which gave subcortical structures a role in high-level cognitive function, is very resonant today but was ignored for several decades after Ritti published his work.