Articles
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.
I don’t often talk about motor or skill memory — that is, the memory we use when we type or drive a car or play the piano. It’s one of the more mysterious domains of memory. We all know, of course, that this is a particularly durable kind of memory. It’s like riding a bicycle, we say — meaning that it’s something we’re not likely to have forgotten, something that will come back to us very readily, even if it’s been a very long time since we last used the skill.
Retrieval practice, as its name suggests, is a simple strategy that involves retrieving the target information one or more times prior to testing. It is not the same as repetition or rehearsal! The idea is not to simply repeat the correct information, but to try and retrieve it. Feedback as to the correct answer may or may not follow.
There was an alarming article recently in the Guardian newspaper. It said that in the UK, diabetes is now nearly four times as common as all forms of cancer combined. Some 3.6 million people in the UK are thought to have type 2 diabetes (2.8 are diagnosed, but there’s thought to be a large number undiagnosed) and nearly twice as many people are at high risk of developing it. The bit that really stunned me? Diabetes costs the health service roughly 10% of its entire budget.
In the last part I talked about retrieval structures and their role in understanding what you’re reading. As promised, this month I’m going to focus on understanding scientific text in particular, and how it differs from narrative text.
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.
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).
Until recent times, attention has always been quite a mysterious faculty. We’ve never doubted attention mattered, but it’s only in the past few years that we’ve appreciated how absolutely central it is for all aspects of cognition, from perception to memory. The rise in our awareness of its importance has come in the wake of, and in parallel with, our understanding of working memory, for the two work hand-in-hand.
What do we mean by word-finding problems?
Here are some examples:
- increasing use of circumlocutions rather than specific terms (e.g., "I wonder where the thing that goes here is")
- use of empty phrases, indefinite terms, and pronouns without antecedents (i.e., referring to something or someone as "it" or "him / her" without first identifying them by name)
- increased frequency of pauses
These problems are all characteristic of Alzheimer's, but also, to a much lesser extent, of normal aging.