I talk a lot about how working memory constrains what we can process and remember, but there’s another side to this — long-term memory acts on working memory. That is, indeed, the best way of ‘improving’ your working memory — by organizing and strengthening your long-term memory codes in such a way that large networks of relevant material are readily accessible.
Oddly enough, one of the best ways of watching the effect of long-term memory on working memory is through perception.
I’ve discussed on a number of occasions the effects that stereotypes can have on our cognitive performance. Women, when subtly reminded that females are supposedly worse at math, do more poorly on math tests; African-Americans, when subtly reminded of racial stereotypes, perform more poorly on academic tests. And beliefs about the effect of aging similarly affect memory and cognition in older adults.
External memory aids include such strategies as:
If you have a numbered list to memorize, the best mnemonic strategy is the pegword mnemonic. This mnemonic uses numbers which have been transformed into visual images. Here's the standard 1-10 set.
I add two more:
When we are presented with new information, we try and connect it to information we already hold. This is automatic. Sometimes the information fits in easily; other times the fit is more difficult — perhaps because some of our old information is wrong, or perhaps because we lack some of the knowledge we need to fit them together.
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).
I’ve always been interested in the body’s clocks — and one of the most interesting things is that it is clocks, in the plural. It appears the main clock is located in a part of the brain structure called the hypothalamus (a very important structure in the brain, although not one of much importance to learning and memory). The part of the hypothalamus that regulates time is called the suprachiasmatic nuclei. These cells contain genes that switch on, off, and on again over a 24-hour period, and send electrical pulses and hormones through the body. This is the body’s master clock.
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.
I want to talk to you this month about an educational project that’s been running for some years here in New Zealand. The Project on Learning spent three years (1998-2000) studying, in excruciating detail, the classroom experiences of 9-11 year olds. The study used miniature videocameras, individually worn microphones, as well as trained observers, to record every detail of the experiences of individual students during the course of particular science, maths, or social studies units.
An analysis of English vocabulary* has found that the first 1000 words account for 84.3% of the words used in conversation, 82.3% of the words encountered in fiction, 75.6% of the words in newspapers, and 73.5% of the words in academic texts. The second 1000 accounts for about another 5% (specifically, 6% of conversation, 5.1% of fiction, 4.7% of newspapers, 4.6% of academic texts).