Skip to main content

Articles

Humans are the animals that manipulate their cognitive environment.

Does photographic memory exist?

"Photographic" or eidetic memory is said to occur in some 8% of children, but almost all of these grow out of it. The phenomenon is extremely rare in adults, and indeed the very existence of photographic memory is still somewhat contentious. However, it may be that particular brain abnormalities can lead to ways of processing information that are dramatically different from the normal (see the case of Kim Peek).

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.

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.

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).

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.

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.

A New Yorker cartoon has a man telling his glum wife, “Of course I care about how you imagined I thought you perceived I wanted you to feel.” There are a number of reasons you might find that funny, but the point here is that it is very difficult to follow all the layers. This is a sentence in which mental attributions are made to the 6th level, and this is just about impossible for us to follow without writing it down and/or breaking it down into chunks.

Although I’m a cognitive psychologist and consequently think that memory and cognition is mostly about your mastery of effective strategies, when it comes to age-related cognitive decline, I’m a big believer in the importance of diet and exercise. But while we know these things can play an important role in why some people develop cognitive impairment and even dementia as they age, and others don’t, we don’t yet know with any great certainty exactly what exercise programs would be the best use of our time, and what diet would have the most benefit.

A fascinating article recently appeared in the Guardian, about a woman who found a way to overcome a very particular type of learning disability and has apparently helped a great many children since.