Before revision: A mental image is an experience that, on most occasions, significantly resembles the experience of 'perceiving' some object, event, or scene, but occurs when the relevant object, event, or scene is not actually present to the senses.McKellar, 1957Richardson, 1969Finke, 1989Thomas, 2003 There are sometimes episodes, particularly on falling asleep (hypnagogic imagery) and waking up (hypnopompic imagery), when the mental imagery may be dynamic, phantasmagoric and involuntary in character, repeatedly presenting identifiable objects or actions, spilling over from waking events, or defying perception, presenting a kaleidoscopic field, in which no distinct object can be discerned.
After revision: In philosophy of mind, neuroscience, and cognitive science, a mental image is an experience that, on most occasions, significantly resembles the experience of 'perceiving' some object, event, or scene, but occurs when the relevant object, event, or scene is not actually present to the senses.McKellar, 1957Richardson, 1969Finke, 1989Thomas, 2003 There are sometimes episodes, particularly on falling asleep (hypnagogic imagery) and waking up (hypnopompic imagery), when the mental imagery may be dynamic, phantasmagoric and involuntary in character, repeatedly presenting identifiable objects or actions, spilling over from waking events, or defying perception, presenting a kaleidoscopic field, in which no distinct object can be discerned.