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.

I was recently asked for advice in the case of increased “brain blocks” — failures to retrieve information that should be readily accessible. This question is, I suspect, of interest to many of my readers, so I thought I would answer it here.

There are many possible causes for an increase in this type of memory failure. These causes fall into three main categories: physical, environmental, and strategic. Let’s deal with the physical first.

Recently a “Framework for Success in Postsecondary Writing” came out in the U.S. This framework talked about the importance of inculcating certain “habits of mind” in students. One of these eight habits was metacognition, which they defined as the ability to reflect on one’s own thinking as well as on the individual and cultural processes used to structure knowledge.

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.

We all know that lack of sleep makes us more prone to attentional failures, more likely to make mistakes, makes new information harder to learn, old information harder to retrieve ... We all know that, right? And yet, so many of us still go to bed too late to get the sleep we need to function well. Of course, some of us go to sleep early enough, we just can’t get to sleep fast enough, or are prone to waking in the night. (Personally, I can count the times I’ve slept through the night without waking in the last fifteen years on my fingers).

Find out about the pegword mnemonic

To celebrate Māori Language Week here in Aotearoa (New Zealand), I've put together a pegword set in te reo:

1. tahi — ahi
2. rua — ua
3. toru — tūru
4. whā — taniwha
5. rima — rama
6. ono — hono
7. whitu — whatu
8. waru — karu
9. iwa — taraiwa
10. tekau — rākau

Planning memory contains your plans and goals (such as, “I must pick up the dry-cleaning today”; “I intend to finish this project within three months”). Forgetting an appointment or a promise is one of the memory problems people get most upset about.

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.

I don't think anyone's going to try arguing that fruit and vegetables are not good for your health! We know they're good. But that's just general "oh, I know it's good for me" — do you know that the benefits are not only for your general health, your protection against obesity and diabetes, cancer and heart disease, but also for your brain. Actually, there's two aspects to this. An unhealthy diet (one rich in junk food, in saturated fat and sugar) is actively bad for your brain, and (the right) healthy diet is actively good for your brain.

The limitations of working memory have implications for all of us. The challenges that come from having a low working memory capacity are not only relevant for particular individuals, but also for almost all of us at some points of our lives. Because working memory capacity has a natural cycle — in childhood it grows with age; in old age it begins to shrink. So the problems that come with a low working memory capacity, and strategies for dealing with it, are ones that all of us need to be aware of.