What are Mental Images?

What are Mental Images?

From a common-sense point of view, answering this question seems relatively easy. Everyone is generally agreed that having a mental image is

SEEING SOMETHING IN THE MIND'S EYE.

This is distinct from actually seeing something "out there" in physical reality. When we have a mental image of something, we picture it inwardly.

What common experiences are connoted by "having a mental image"? Many types of experiences readily suggest themselves, including

  • HAVING A DREAM
  • REMEMBERING SOMETHING CLEARLY
  • HALLUCINATING
  • CREATING AN ACTIVE FANTASY (DAYDREAMING)
  • SOLVING A PROBLEM OR PUZZLE WITH A MENTAL PICTURE
  • VISUALIZING AN OBJECT IN SPACE.

    • Although these intuitions about mental images are common-place and seem straight-forward, many philosophic problems are presented by the notion of mental images. The reason is that framing an answer to this question "what is a mental image?" presumes we have some sort of answers to other more general, and exceedingly difficult questions: What are mental phenomena in general? What are their characteristics? When we say that we "see something in the mind's eye" what do we really mean? How are we to understand the notion of some "thing" being "inside" the mind? Is there a special realm, or "mental space" in which mental objects may be said to exist or reside? Surely, we want to avoid the connotation that mental images are like ordinary physical objects residing in physical space. If mental images are not physical things, does this mean there is a special category of "things" that are mental or non-material in nature? Again, when we say that we "see" mental images, what can this really mean? How is "inward" seeing different from "seeing" things "out there." Is it really the same thing? Is "see" the right word to use when we speak of experiencing mental images?

    Philosophers and psychologists who aim at discovering the nature of mental images have found it difficult to answer these additional questions. One way to begin answering these questions is to notice that most people would probably agree having a mental image is

    SIMILAR TO ACTUALLY SEEING SOMETHING.

    It is crucial to note, however, that no matter how "similar" such an experiece may be to seeing, the phrase "having a mental image" means the experience does not involve actual vision -- that is, we are not actually seeing any physical object when we have a mental image. We might put it this way: having a mental image is

    "SEEING" SOMETHING THAT IS NOT THERE.

    The quotes around the word "seeing" are necessary, for we do not mean we literally "see" something that is not there when we are having a mental image. Even a person who is having a hallucination does not actually SEE anything.

    The degree to which, or even whether, having mental images ought to be thought of as SIMILAR to seeing, has been the subject of much debate in philosophy and psychology. One of the fundamental problems faced by

    EMPIRICAL PSYCHOLOGY

    is that it requires concrete experimental evidence and clearly defined terms. There has been a long-standing dispute whether the science of psychology should be primarily concerned with

    SUBJECTIVE DESCRIPTIONS OF MENTAL STATES

    (e.g.,"I am having the mental image of a cat") or on

    BEHAVIOR AND THEORIES ABOUT THE CAUSES OF BEHAVIOR

    (e.g., "the subject pointed to a picture of a cat, because the subject's brain cells had been previously stimulated by a similar image"). This dispute has led to two basic notions about the nature of mental images. The first notion adheres more closely to to approach we have developed above: mental images involve an experience similar to seeing that occurs in the absence of anything that can actually be seen. This approach has been used to formulate a formal definition of mental imagery in traditional psychology.

    The traditional approach concentrates on formulating the similarities and differences among the various types of imagery recognized by common experience, as well as those produced in special circumstances (e.g., through the effect of drugs or laboratory experiments). The similarities and differences among these experiences indicate that it may be useful to categorize mental images according to imagery types. From the traditional perspective, this inventory or properties of various types of mental images will help us answer the initial question, "What are mental images?"

    The second notion concentrates on the requirements for gathering experimental data and for generating computational theories about the mind. It has been used to develop a definition, or approach, in contemporary psychology and cognitive science.

    The organization of these introductory pages derives from the first, or common-sense sense notion of mental images used in traditional psychology and the various imagery types it recognizes, but the basics of the cognitive science approach are included as well.

    Return to Introduction to Mental Images Page

    Revised: June 6, 2000