Articles

What constitutes proof? How much weight can we put on research results?

I’ve been reporting on memory research for 20 years, and this issue has always been at the back of my mind. Do my readers understand these questions? Do they have the background and training to give the proper amount of weight to these particular research findings? I put in hints and code words (“pilot study”; “this study confirms”; “adds to the evidence”; “conclusive”; and so on), but are these enough?

So here is the article I’ve always meant to write.

Short-term vs long-term memory

Working memory is a relatively recent term, a refinement of an older concept - that of short-term memory. Short-term memory was called thus to distinguish it from "long-term memory" - your memory store.

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.

The thing to remember about Ericsson’s famous expertise research, showing us the vital importance of deliberate practice in making an expert, is that it was challenging the long-dominant view that natural-born talent is all-important. But Gladwell’s popularizing of Ericsson’s “10,000 hours” overstates the case, and of course people are only too keen to believe that any height is achievable if you just work hard enough.

The much more believable story is that, yes, practice is vital — a great deal of the right sort of practice — but we can’t disavow “natural” abilities entirely.

Remembering a skill is entirely different from remembering other kinds of knowledge. It’s the difference between knowing how and knowing that.

Humans have a long tradition of holding genes responsible for individual differences in behavior (of course, we called it "blood", then, or "family"). In the 20th century, a counter-belief arose: that it was all down to environment, to upbringing. In more recent decades, we have become increasingly aware of how tightly and complexly genes and environment are entwined.

In the following case study, I explore in depth the issue of learning the geological time scale — names, dates, and defining events. The emphasis is on developing mnemonics, of course, but an important part of the discussion concerns when and when not to use mnemonics, and how to decide.

The Geological Time Scale

Phanerozoic Eon 542 mya—present

  Cenozoic Era 65 mya—present

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.

Our society gives a lot of weight to intelligence. Academics may have been arguing for a hundred years over what, exactly, intelligence is, but ‘everyone knows’ what it means to be smart, and who is smart and who is not — right?

Of course, it’s not that simple, and the ins and outs of academic research have much to teach us about the nature of intelligence and its importance, even if they still haven’t got it all totally sorted yet. Today I want to talk about one particular aspect: how important intelligence is in academic success.

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.