ABSTRACT
This chapter discusses psycho-physiological studies of imaginal processing during waking and hypnosis, as moderated by hypnotic level, in light of recent shifts in theoretical thinking about the neuropsychophysiological substrates of mental imagery. It examines several theories of visual perception and their applicability to the understanding of mental imagery. Perceptual alterations and suggested hallucinations are the core phenomena of hypnosis. Phenomenologically, imagery is often experienced as being more intense and hallucinatory during hypnosis. Neuroimaging techniques that assess regional brain metabolism offer a sensitive and reliable evaluation of brain function and cerebral organization during cognitive task activity. Commonly given hypnotic suggestions ask persons to "image" or "imagine" an arm getting stiff, regressing to an earlier age, seeing something that is not present or not seeing or feeling or smelling something that is actually present. These mental images may or may not occur in conjunction with incoming sensory stimuli.
