Articles

• Is there such a thing as a photographic memory?
• Will memorizing lists and speeches improve my memory?
• I've read that people only use 10% of their brain. Is this true?
• I seem to have more trouble remembering words and names I know perfectly well.

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.

Prevalence of dementia

Dementia is estimated¹ to afflict over 35.5 million people worldwide -- this includes nearly 10 million people in Europe, nearly 4.4 million in North America, nearly 7 million in South and Southeast Asia, about 5.5 million in China and East Asia and about 3 million in Latin America.

As I said in my discussion of different scripts, the Hellenic languages use the Greek alphabet. Here it is. I’m afraid the table is a little complicated, because (a) each letter has a name, which it’s useful to know, and (b) there are some differences in pronunciation between Ancient Greek (which is still a language that people want to learn today), and Modern Greek.

Prevalence

Vascular dementia, as its name suggests, is caused by poor blood flow, produced by a single, localized stroke, or series of strokes.

It is the second most common dementia, accounting for perhaps 17% of dementias. It also co-occurs with Alzheimer's in 25-45% of cases. Although there are other types of dementia that also co-occur with Alzheimer's, mixed dementia generally refers to the co-occurrence of Alzheimer's and vascular dementia.

I’ve recently had a couple of thoughts about flow — that mental state when you lose all sense of time and whatever you’re doing (work, sport, art, whatever) seems to flow with almost magical ease. I’ve mentioned flow a couple of times more or less in passing, but today I want to have a deeper look, because learning (and perhaps especially that rewiring I was talking about in my last post) is most easily achieved if we can achieve "flow" (also known as being ‘in the zone’).

Let’s start with some background.

Having trouble sleeping is perfectly normal, especially as we age. It’s estimated that half of those older than 55 have trouble getting to sleep or staying asleep.

What to do if your sleep is poor

Let’s start with the easiest situation: you’re not getting enough sleep because you wilfully go to bed too late to achieve your needs.

In 2002, a British study scanned the brains of ten "superior memorizers" — eight leading contenders in the World Memory Championships, and two individuals previously studied for their extraordinary memory accomplishments — all people that had demonstrated truly impressive feats of memory, in terms of the ability to quickly memorize hundreds of numbers or unrelated words. The ten "memory champions" were matched with ten controls, who had no memory capabilities out of the ordinary.

Brain tissue is divided into two types: gray matter and white matter. These names derive very simply from their appearance to the naked eye. Gray matter is made up of the cell bodies of nerve cells. White matter is made up of the long filaments that extend from the cell bodies - the "telephone wires" of the neuronal network, transmitting the electrical signals that carry the messages between neurons.

The volume of gray matter tissue - a measure you will see cited in various reports - is a measure of the density of brain cells in a particular region.

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.