Dementia is estimated1 to afflict over 35.5 million people worldwide -- this includes nearly 10 million people in Europe, nearly 4.4 million in North America, nearly 7 million in South and Southeast Asia, about 5.5 million in China and East Asia and about 3 million in Latin America.
Several genes have been implicated in Alzheimer's, but the big one is the e4 allele of the ApoE gene (on chromosome 19). This variant is found in about a quarter of the population.
Having it doesn't mean you are foreordained to develop Alzheimer's, but it certainly increases the risk substantially. The risk goes up considerably more if both of your genes are the e4 variant (remember you inherit two: one from each parent).
The thing to remember about Ericsson’s famous expertise research, showing us the vital importance of deliberate practice in making an expert, is that it was challenging the long-dominant view that natural-born talent is all-important. But Gladwell’s popularizing of Ericsson’s “10,000 hours” overstates the case, and of course people are only too keen to believe that any height is achievable if you just work hard enough.
The much more believable story is that, yes, practice is vital — a great deal of the right sort of practice — but we can’t disavow “natural” abilities entirely.
In a recent news report, I talked about how walking through doorways creates event boundaries, requiring us to update our awareness of current events and making information about the previous location less available. I commented that we should be aware of the consequences of event boundaries for our memory, and how these contextual factors are important elements of our filing system. I want to talk a bit more about that.
It has long been known that spacing practice (reviewing learning or practicing a skill at spaced intervals) is far more effective than massed practice (in one heavy session). An interesting example of this comes from a study that aimed to find the best way of teaching postmen to type (this was at the request of the British Post Office). The researchers put postmen on one of four schedules:
We don’t deliberately practice our memories of events — not as a rule, anyway. But we don’t need to — because just living our life is sufficient to bring about the practice. We remember happy, or unpleasant, events to ourselves, and we recount our memories to other people. Some will become familiar stories that we re-tell again and again. But facts, the sort of information we learn in formal settings such as school and university, these are not something we tend to repeatedly recount to ourselves or others — not for pleasure anyway!
On my walk today, I listened to a downloaded interview from the On Being website. The interview was with ‘vocal magician and conductor’ Bobby McFerrin, and something he said early on in the interview really caught my attention.
As we all know, rhyme and rhythm help make information more memorable. Here's a few ideas that may help you use them more effectively.
Rhythm and rhyme are of course quite separate things, and are processed in different regions of the brain. However, they do share some commonalities in why and how they benefit memory. Rhyme and rhythm impose pattern. For that reason, rhyme and rhythm are particularly valuable when information is not inherently meaningful.
Brain tissue is divided into two types: gray matter and white matter. These names derive very simply from their appearance to the naked eye. Gray matter is made up of the cell bodies of nerve cells. White matter is made up of the long filaments that extend from the cell bodies - the "telephone wires" of the neuronal network, transmitting the electrical signals that carry the messages between neurons.
The volume of gray matter tissue - a measure you will see cited in various reports - is a measure of the density of brain cells in a particular region.
The limitations of working memory have implications for all of us. The challenges that come from having a low working memory capacity are not only relevant for particular individuals, but also for almost all of us at some points of our lives. Because working memory capacity has a natural cycle — in childhood it grows with age; in old age it begins to shrink. So the problems that come with a low working memory capacity, and strategies for dealing with it, are ones that all of us need to be aware of.