Adams, W.A. (2009). Studying visual imagery with cognitive science: Benefits and drawbacks. [Review of the book, The Visual World in Memory]. PsycCRITIQUES – Contemporary Psychology: APA Review of Books, September 2, 2009, Vol. 54, Release 35, Article 6].
According to some contributors to this edited volume, the study of mental imagery no longer wears the shameful scarlet letter of introspection. Ingenious neurological and behavioral techniques now let us study mental images scientifically. For example, consider the question of whether mental images are really pictures in the head, or merely descriptive representations that use the language of visual perception. Reviewing brain imaging studies, one group of authors finds that there is a 90% overlap in the areas of the brain activated in visual perception and in visual imagination. That is fairly strong evidence that mental images really are pictures in the head, and that is a remarkable thing to be able to say scientifically.
However, science comes at a price. Everything must be defined operationally, exactly, in terms of physical measurements. There is no common sense meaning attached to terms like imagery, consciousness, mind, picture, imagination, recognition, or anything else. Consequently, the reader is never sure if the findings of these studies can be interpreted in ordinary terms. This is a problem of external validity: the scientific operations are so controlled and the definitions so artificially contrived, you no longer know what the study is actually about. Is it a fair trade to sacrifice intuitive understanding to get scientific findings? That is the question this book leaves.