To people entering their later years, embarrassed by forgetfulness, the situation seems gloomy. However, although memory change is normal and inevitable even among healthy adults, there are bright spots – in part because memory’s different aspects change at different rates, and in part because new insights into memory are bringing us better ways to cope.

What is Memory?
Memory is best viewed as a process rather than a thing, a verb rather than a noun. To remember means to store and retrieve information over time, according to Dr. Guy Proulx, the director of psychology at Baycrest.

The same learning process applies to snow-suited toddlers finding ice is slippery, to students memorizing the names of the Great Lakes, to vacationers exploring a new city, and to grandparents noticing a grandchild’s favourite toy. As in all of these cases, learning and memory are adaptive.

Memory ability varies from person to person, says Dr. Fergus Craik, a world-renowned authority on memory and a senior scientist at Baycrest’s Rotman Research Institute. Because memory is bound up with other core mental operations, he adds, such as attentiveness and speed of processing, whether people experience generally good or poor memory relates to overall brain efficiency.

Beyond that, researchers have found that “good memory” also relates to expertise and depth of knowledge. Notes Dr. Craik, “Within the individual, the ability to encode, manipulate and retrieve certain kinds of information depends on whether they deal with it frequently.” He cites the eight-year-old dinosaur maven and the 80-year-old lifelong bridge player, both with impressive memories within their specialties.

Dr. Fergus CraikMemory, as a noun, is also the “what” that gets embedded in the brain. Although scientists have not yet completely specified the biology of memory, it is known that memories get laid down in what Dr. Craik describes as “structural networks of neurons [nerve cells, most often in the brain] that are structurally altered so they can fire more easily in retrieval.” The more that people call up these connections, the more quickly they respond to the call. Thus, frequently retrieved memories become more accessible.

Memory is not monolithic; different types serve distinctly different purposes. Those most commonly studied include episodic, which Dr. Craik describes as re-experiencing, at least in part, a previous event (What did I read in the paper this morning?); semantic, the facts and procedures that we learn in full awareness (When do we file our taxes?); working, or holding something in our mind while manipulating it (What’s $10 minus $2?); procedural (How do I button a shirt?); and prospective, laying down an intention to perform a planned action (Remember to pick up milk after work!). Retrospective memory refers to remembering information from the past (Now, where did I put those darn keys?).

Finally, researchers are careful to distinguish between recall and recognition. Recall is remembering things cold, without cues or hints. Recognition is remembering things given relevant information or context, as happens with multiple-choice questions or bringing an eyewitness back to the scene of the crime. The recall/recognition distinction becomes more important as we age – recall gets relatively more difficult, as recognition reminds us of the original event.

Memory & Aging: Like a Fine Wine?
Well, not exactly. Dr. Craik is the first to admit that “some things hold up well as we age and some don’t.” He cites recent evidence that cognitive function peaks when people are in their 20s. What’s more, the frontal lobes, which finally reach their peak maturity early in that decade, are the first to fade, creating a sort of “last in, first out” effect in brain development.

By the 40s, Dr. Craik adds, “There is some lessening of efficiency. We’re not laying down such rich memories and we’re becoming less efficient at retrieving them.”

To be perversely positive, at least this means that memory problems are not unique to old age. Researchers attribute anxiety about middle-aged memory loss to several things: First, slips may increase in frequency, becoming more noticeable and disruptive. Second, society bombards us with negative messages about memory and aging, fanning the flames of fear. Third, there are understandable worries that lapses are the first signs of dementia, such as Alzheimer’s disease.

Researchers are hotly pursuing the kinds of large-scale, long-term studies that will provide the most clear and reliable data on normal changes of aging. In the meantime, some basics may help people to sort out their own situations.

What’s Normal Memory Change, What’s Not?
Most memory changes are normal. Dr. Proulx points out that aging is nothing more than change over time; both body and mind must follow nature’s course. He comments, “If things didn’t change over time, the laws of physics would be blown out the window.”

Aging is both multi-dimensional (biological, psychological, social and cultural) and multi-directional. “There are losses, there are gains, and there are stabilities,” says Dr. Proulx. It’s much the same for memory itself.

 

 

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