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.
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.
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.
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).
One of my perennial themes is the importance of practice, and in the context of developing expertise, I have talked of ‘deliberate practice’ (a concept articulated by the well-known expertise researcher K. Anders Ericsson). A new paper in the journal Psychology of Music reports on an interesting study that shows how the attributes of music practice change as music students develop in expertise. Music is probably the most studied domain in expertise research, but I think we can gain some general insight from this analysis. Here’s a summary of the findings.
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.
Forget the persistent myth that everything is remembered; that our brains are video cameras whirring away recording everything, and that such 'hidden' knowledge can be brought to light by a hypnotist or alien artefact. Such things are the stuff of fantasy. Of course, there is a nugget of truth there: we can, and do, remember things we've paid no conscious attention to. Sometimes the right question can elicit memories we didn't know we had, in more detail than we imagined we could have. But for the most part, what's not noticed is not remembered. Attention is crucial to memory.
Here are some notes on the water cycle:
Precipitation & flow: “whether they are typhoons or Scotch mists, mountain torrents or field ditches or city sewers, they are simply water sinking back to base level, the sea.”
Evaporation = the act of passively presenting water to the atmosphere to be soaked up + vaporized by the sun’s energy.
Transpiration= evaporation thru plants
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.
A lot of theories have been thrown up over the years as to what we need sleep for (to keep us wandering out of our caves and being eaten by sabertooth tigers, is one of the more entertaining possibilities), but noone has yet been able to point to a specific function of the sleep state that would explain why we have it and why we need so much of it.