Articles

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 recently reported on a finding that memories are stronger when the pattern of brain activity is more closely matched on each repetition, a finding that might appear to challenge the long-standing belief that it’s better to learn in different contexts. Because these two theories are very important for effective learning and remembering, I want to talk more about this question of encoding variability, and how both theories can be true.

Autobiographical memory contains the information you have about yourself. It includes several domains:

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.

We don’t deliberately practice our memories of events — not as a rule, anyway. But we don’t need to — because just living our life is sufficient to bring about the practice. We remember happy, or unpleasant, events to ourselves, and we recount our memories to other people. Some will become familiar stories that we re-tell again and again. But facts, the sort of information we learn in formal settings such as school and university, these are not something we tend to repeatedly recount to ourselves or others — not for pleasure anyway!

Prevalence of Parkinson's Disease

After Alzheimer's disease, the second most common neurodegenerative disorder is Parkinson’s disease. In the U.S., at least 500,000 are believed to have Parkinson’s, and about 50,000 new cases are diagnosed every year¹ (I have seen other estimates of 1 million and 1.5 million — and researchers saying the numbers are consistently over-estimated while others that they are consistently under-estimated!). In the U.K., the numbers are 120,000 and 10,000².

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.

Consider our facts about blood:

• arteries are thick and elastic and carry blood that is rich in oxygen from the heart.
• veins are thinner, less elastic, and carry blood rich in carbon dioxide back to the heart.

We could, as is often advised, simply turn these into why questions. And we can answer these on the basis of the connections we’ve already made:

Why are arteries elastic?

Because they need to accommodate changes in pressure

Why are arteries thick?

Because they need to accommodate high pressure

As I said in my discussion of different scripts, Russian uses the Cyrillic alphabet. Here it is (the 3rd column shows the English counterpart):

А  а   a

Б  б   b

В  в   v

Г  г   g

Д  д   d

Е  е   ye

• 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.