Visual hallucinations are due to activation of visual memory circuits by diffuse toxicity, as seen in the moribund Elizabeth I, who: “…sword in hand…thrust at the arras on the walls of the bedroom at the spectres which tormented her.”

Tactile hallucinations are due to activation of tactile memory circuits by diffuse toxicity, as seen in John Hutley, whose formication is described in The Stroller’s Tale from The Pickwick Papers: “…hideous crawling things, with eyes that stared upon him, and filled the very air around, glistening horribly amidst the thick darkness of the place.”

The auditory hallucinations of schizophrenia are not perceptions without stimuli, they are apperceptions without responses, specifically the corollary discharges of arousal that normally indicate apperceptive ownership of one’s responses to perception: apperception minus corollary discharge equals perception. 

Arousal that has been inhibited during childhood is intensified by the hormones of adolescence, and because the arousal is unfamiliar, it appears to be perceptive rather than apperceptive: there is a lack of apperceptive memories inclusive of first-person singular pronouns with which to connect and understand the intensified arousal.

The experience of self, and thus of first-person singular pronouns, requires the conjunction of subject activations and object inhibitions: at a moment when the subject feels alive, the object characterises the subject to the subject, without subjectivity.

Supposedly supernatural, occult, talismanic, and magical events are apperceptions by naive, or disingenuous, individuals, who do not ask, or who decide not to ask themselves: “Why am I choosing to behave in this way, in this place, at this time?”

Illusions vary within and between subjects, so they should be tested with systematic control of subjects and stimuli. When scans can distinguish between cortical layers, illusions will show less activation in the layers that perceive than in the layers that remember.

We recall apperceptions through our mind’s eye and our mind’s ear.