Skip to main content

Articles

Why do we need sleep?

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.

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:

Research with children has demonstrated that the ability to learn new words is greatly affected by working memory span - specifically, by how much information they can hold in that part of working memory called "phonological short-term memory". The constraining effect of working memory capacity on the ability to learn new words appears to continue into adolescence.

Brain autopsies have revealed that a significant number of people die with Alzheimer’s disease evident in their brain, although in life their cognition wasn’t obviously impaired. From this, the idea of a “cognitive reserve” has arisen — the idea that brains with a higher level of neuroplasticity can continue to work apparently normally in the presence of (sometimes quite extensive) brain damage.

Speed-reading techniques

Like many memory improvement courses, speed-reading programs tend to make inflated claims. Also like memory programs, most speed-reading programs proffer the same advice. In essence, speed-reading techniques involve the following components:

In October I reported on a study that found older adults did better than younger adults on a decision-making task that reflected real-world situations more closely than most tasks used in such studies. It was concluded that, while (as previous research has shown) younger adults may do better on simple decision-making tasks, older adults have the edge when it comes to more complex scenarios. Unsurprisingly, this is where experience tells.

One of the points I mention in my book on notetaking is that the very act of taking notes helps us remember — it’s not simply about providing yourself with a record. There are a number of reasons for this, but a recent study bears on one of them. The researchers were interested in whether physically writing by hand has a different effect than typing on a keyboard.

I was listening on my walk today to an interview with Edward Tufte, the celebrated guru of data visualization. He said something I took particular note of, concerning the benefits of concentrating on what you’re seeing, without any other distractions, external or internal. He spoke of his experience of being out walking one day with a friend, in a natural environment, and what it was like to just sit down for some minutes, not talking, in a very quiet place, just looking at the scene.

Here are some notes on the water cycle:

Hydrological (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

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.