THIS paper summarizes visual events reported by patients with intractable temporal lobe epilepsy when brain tissue was stimulated by means of depth electrodes. The study of such visual events yields information pertinent to the processes involved in perception, memory, and imagery formation.
Temporal lobe seizures often are preceded by auras which consist of some kind of internal or external (as projected) sensation. The sensations may be of hallucinatory vividness and intensity and may be simple or complex in any modality of sensation. An example of a simple visual hallucination would be flickering lights; a complex visual hallucination might be an animated scene involving apparitions of people. Auditory, vestibular, kinesthetic, olfactory, gustatory, visceral, or somatosensory hallucinations may occur.Intrusive visual thought images, lacking the apparent real existence or vividness of a true hallucination, are sometimes reported as an aura experience. Such visual images are usually
Horowitz MJ, Adams JE, Rutkin BB. Visual Imagery on Brain Stimulation. Arch Gen Psychiatry. 1968;19(4):469-486. doi:10.1001/archpsyc.1968.01740100085013