Articles

There hasn't been a lot of research into the effects of herbs and spices on cognition and the brain, unfortunately. But on the positive side, the risk of side-effects is very low, so we don't need a lot of evidence for it to be worth trying.

How many words do you need to learn?

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).

Let's look a little deeper into the value of mnemonics for knowledge acquisition. By “knowledge acquisition”, I mean the sort of information you learn from textbooks — information that is not personal, that you need for the long-term.

In this context, I believe the chief value of mnemonic strategies is to help you recall information that needs to be remembered in a particular order. Thus we use mnemonics to help us remember the order of the planets, the order of musical notes on the stave, the order of the colors in a rainbow.

Distributed practice more effective than massed practice

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:

What constitutes proof? How much weight can we put on research results?

I’ve been reporting on memory research for 20 years, and this issue has always been at the back of my mind. Do my readers understand these questions? Do they have the background and training to give the proper amount of weight to these particular research findings? I put in hints and code words (“pilot study”; “this study confirms”; “adds to the evidence”; “conclusive”; and so on), but are these enough?

So here is the article I’ve always meant to write.

Vocabulary is a sticking point for many language learners. That’s because words have a certain arbitrary quality that makes them hard to memorize. There are two strategies which are very effective with this task: the keyword mnemonic, and retrieval practice. I have written about these extensively in my books Mnemonics for Study, and How to revise & practice.

Frances Yates described the memory strategy valued by the ancient Greeks and Romans as the "Art of Memory" in her widely quoted and seminal book The Art of Memory. Today we know it as the method of loci. But the Art of Memory, as those of the ancient world and those of the medieval world practiced it, is far richer than is implied by that title.

On a number of occasions I have reported on studies showing that people with expertise in a specific area show larger gray matter volume in relevant areas of the brain. Thus London taxi drivers (who are required to master “The Knowledge” — all the ways and byways of London) have been found to have an increased volume of gray matter in the anterior hippocampus (involved in spatial navigation). Musicians have greater gray matter volume in Broca’s area.

I have previously reported on how gait and balance problems have been associated with white matter lesions, and walking speed and grip strength have been associated with dementia and stroke risk.

This is the last part in my series on understanding scientific text. In this part, as promised, I am going to talk about the difficulties novices have with scientific texts; what they or their teachers can do about it; and the problems with introductory textbooks.