THE MEMORY CURE by Thomas H. Crook III, Ph.D. & Brenda Adderly, M.H.A., Pocket Books, New York, 1998, 287 pages, $24. ISBN:0-671-02642-9

Thomas H. Crook III, an international expert on memory retention and loss, along with Brenda Adderly, M.H.A., a health care researcher, writer and former staff assistant under Dr. C Everett Koop, explain "What is Memory?" and "Why we Forget."

In each of our lives there comes a time when we are afflicted with more than simple forgetfulness. We begin to forget important things. Since less than 10 percent of us get Alzheimer's disease or irreversible memory loss, there is a large area of loss for which many proposals of alleviation are being investigated. The authors treat the problem of age associate memory impairment (AAMI) which affects all of us past age 40. Dr. Crook has conducted research that actually measures memory loss.

There are four types of memory. Immediate memory lets you look up a telephone number, dial it, and then forget it. Short-term memory or "concentrating" stays with us for minutes or hours but may have no value to us next week. We can usually remember seven chunks of information, give or take two, at the same time. For instance, the letters S-E-E-C-I-A-C-B-S can be thought of as nine chunks (hard for most people to memorize), or as three chunks, SEE, CIA, and CBS (much easier to recall).

Long-term or "permanent" memory stores knowledge about our friends, job, locations, and (hopefully) most of our medical education. It too fades, but more gradually, and can be recalled. The more often recalled, the more permanent it becomes. Long-term memory can store a quadrillion bits of information (10¹⁵ bits--is that really a million times more than my gigabyte hard drive?)

Finally, remote or procedural memory is essentially unforgettable knowledge, much of which seems to have been with us all our lives, and that we always recall this side of Alzheimer's disease. This includes our names, our family, our long-time friends, childhood memories, even how to recite verses learned in grade school. Remote memory is usually not in the forefront of our consciousness until we need it. We then transfer it into long-term memory. If portions of this are forgotten—such as, after 40 years, the loss of our native tongue—it can be restored in a matter of weeks if the previous environment is reproduced, say by a trip back to our ancestral home. It is then available in long-term memory again.

These four types of memory--immediate, short-term, long-term, and remote--decline at different rates with advancing age. Thus, the degree to which age-related loss needs to be "cured" varies also. The first and last types of memory, immediate and remote, decline relatively little. We may have to concentrate a little harder on immediate recall but it is an insignificant absolute figure. At the other end of the scale, remote memory is so deeply embedded that we retain it unless our minds are badly eroded by disease. Even then, many basal memories persist. For example, an avid lifelong golfer in the final throes of Alzheimer's disease was taken to the golf course. He had no idea what day it was, where he was, by whom he was accompanied, or what game was being played. He certainly had no idea why he was there. Yet when shown a golf bag, he chose an appropriate club and his swing, while stiff and a bit ungainly, still showed hints of his former elegant style.

Most declines come in short-term and long-term memory. Of these, the declines in short-term memory are more apparent and observable: the inability to remember names, faces, appointments, to recall where we put our keys--all very noticeable both to the persons forgetting and to family and friends.