Given her deafness, the auditory part of the brain, deprived of its usual input, had started to generate a spontaneous activity of its own, and this took the form of musical hallucinations, mostly musical memories from her earlier life. The brain needed to stay incessantly active, and if it was not getting its usual stimulation..., it would create its own stimulation in the form of hallucinations.
Oliver SacksWe now know that memories are not fixed or frozen, like Proust's jars of preserves in a larder, but are transformed, disassembled, reassembled, and recategorized with every act of recollection.
Oliver SacksIn general, people are afraid to acknowledge hallucinations because they immediately see them as a sign of something awful happening to the brain, whereas in most cases theyre not.
Oliver Sacks