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I don't think anyone's going to try arguing that fruit and vegetables are not good for your health! We know they're good. But that's just general "oh, I know it's good for me" — do you know that the benefits are not only for your general health, your protection against obesity and diabetes, cancer and heart disease, but also for your brain. Actually, there's two aspects to this. An unhealthy diet (one rich in junk food, in saturated fat and sugar) is actively bad for your brain, and (the right) healthy diet is actively good for your brain.

Context is absolutely critical to successful communication. Think of the common experience of being a stranger at a family gathering or a meeting of close friends. Even familiar words and phrases may take on a different or additional meaning, among people who have a shared history. Many jokes and comments will be completely unintelligible, though you all speak the same language.

Do experts simply know "more" than others, or is there something qualitatively different about an expert's knowledge compared to the knowledge of a non-expert?

While most of us are not aiming for an expert's knowledge in many of the subjects we study or learn about, it is worthwhile considering the ways in which expert knowledge is different, because it shows us how to learn, and teach, more effectively.

Short-term vs long-term memory

Working memory is a relatively recent term, a refinement of an older concept - that of short-term memory. Short-term memory was called thus to distinguish it from "long-term memory" - your memory store.

We all like simple solutions. However much we may believe we are ‘above’ black-&-white dichotomies, that of course we understand that every situation is complex, nevertheless we have a brain that can only think of a very very few things at once. So it's unsurprising that we are drawn to solutions that can be summed up simply, that can fit comfortably within the limitations of working memory.

In the following case study, I explore in depth the issue of learning the geological time scale — names, dates, and defining events. The emphasis is on developing mnemonics, of course, but an important part of the discussion concerns when and when not to use mnemonics, and how to decide.


The Geological Time Scale

Phanerozoic Eon 542 mya—present

  Cenozoic Era 65 mya—present

Reading is a deceptive skill, for it is not a single process, but a number of processes. Thus, while you might be a fluent reader, in that you can swiftly and easily decode the letter-markings, and quickly access the meaning of the words, that doesn't mean you're a skilled reader of informational texts.

Genes

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).

Alzheimer's disease currently affects one in 10 people over age 65 and nearly half of those over age 85.

More than 19 million Americans say they have a family member with the disease, and 37 million say they know somebody affected with Alzheimer's.

In the United States, the average lifetime cost per Alzheimer patient is US$174,000. (These figures are from the U.S. Alzheimer's Association).

This post is the second part in a four-part series on how education delivery is changing, and the set of literacies required in today’s world. Part 1 looked at the changing world of textbooks. This post looks at the oral equivalent of textbooks: direct instruction or lecturing.