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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.

People are poor at assessing their own memory

One thing research seems to show rather consistently is that, for older adults in particular, beliefs about one's own memory performance have little to do with one's actual memory performance¹. People who believe they have a poor memory are usually no worse at remembering than those who believe they have a good memory.

Children’s understanding, and their use of memory and learning strategies, is a considerably more complex situation than most of us realize. To get some feeling for this complexity, let’s start by looking at a specific area of knowledge: mathematics.

Children's math understanding

Here’s a math problem:

Pete has 3 apples. Ann also has some apples. Pete and Ann have 9 apples altogether. How many apples does Ann have?

This seems pretty straightforward, right? How about this one:

The two types of first-letter mnemonics

First-letter mnemonics are, as their name suggests, memory strategies that use the initial letters of words as aids to remembering. This can be an effective technique because initial letters are helpful retrieval cues, as anyone who has endeavored to remember something by mentally running through the letters of the alphabet can attest to.

There are two types of first-letter mnemonic:

I have spoken before, here on the website and in my books, about the importance of setting specific goals and articulating your specific needs. Improving your memory is not a single task, because memory is not a single thing. And as I have discussed when talking about the benefits of ‘brain games’ and ‘brain training’, which are so popular now, there is only a little evidence that we can achieve general across-the-board improvement in our cognitive abilities.

If you have a numbered list to memorize, the best mnemonic strategy is the pegword mnemonic. This mnemonic uses numbers which have been transformed into visual images. Here's the standard 1-10 set.

I add two more:

The mediotemporal lobe (MTL) is a concept rather than a defined brain structure. It includes the hippocampus, the amygdala, and the entorhinal and perirhinal cortices - all structures within the medial area of the temporal lobe.The temporal lobe is in general primarily concerned with sensory experience - specifically, with hearing, and with the integration of information from multiple senses. Part of the temporal lobe also plays a role in memory processing. It is situated below the frontal and parietal lobes, and above the hindbrain.

I talk a lot about how working memory constrains what we can process and remember, but there’s another side to this — long-term memory acts on working memory. That is, indeed, the best way of ‘improving’ your working memory — by organizing and strengthening your long-term memory codes in such a way that large networks of relevant material are readily accessible.

Oddly enough, one of the best ways of watching the effect of long-term memory on working memory is through perception.

Genes

Several genes have been implicated in Alzheimer's, but the big one is the e4 allele of the ApoE gene (on chromosome 19). This variant is found in about a quarter of the population.

Having it doesn't mean you are foreordained to develop Alzheimer's, but it certainly increases the risk substantially. The risk goes up considerably more if both of your genes are the e4 variant (remember you inherit two: one from each parent).

I recently reported on a finding that older adults whose life-space narrowed to their immediate home were significantly more likely to have a faster rate of global cognitive decline or develop mild cognitive impairment or Alzheimer’s.