Most cognitive processes decline with age
It does appear that most component processes of cognition decline with advanced age if the difficulty level is sufficiently high. For example, the following processes have all shown age effects:
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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.
Impaired vision is common in old age and even more so in Alzheimer’s disease, and this results not only from damage in the association areas of the brain but also from problems in lower-level areas. A major factor in whether visual impairment impacts everyday function is contrast sensitivity.
To use note-taking effectively, you need to understand that its primary value is not in the record you produce, it is in the process itself. The process of taking notes guides the memory codes you make. Note-taking is a strategy for making information meaningful. It is therefore only effective to the extent that you paraphrase, organize and make sense of the information while taking notes.
Because it holds some personal resonance for me, my recent round-up of genetic news called to mind food allergies. Now food allergies can be tricky beasts to diagnose, and the reason is, they’re interactive. Maybe you can eat a food one day and everything’s fine; another day, you break out in hives. This is not simply a matter of the amount you have eaten, the situation is more complex than that.
To use a strategy effectively, you need to understand why it works, how it works, when it works and when it doesn’t.
For example, all students take notes — not everyone knows how to do it well. Research into the effectiveness of note-taking has found — surprise, surprise — that sometimes note-taking helps you remember information, and sometimes it doesn’t1.
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.
I want to talk to you this month about an educational project that’s been running for some years here in New Zealand. The Project on Learning spent three years (1998-2000) studying, in excruciating detail, the classroom experiences of 9-11 year olds. The study used miniature videocameras, individually worn microphones, as well as trained observers, to record every detail of the experiences of individual students during the course of particular science, maths, or social studies units.
The effects of exercise on cognitive function in older adults
A number of studies in the past few years have provided evidence that physical exercise can ameliorate the effects of aging on the brain, in terms both of preventing or postponing dementia, and reducing the more normal age-related decline in cognitive function. The reasons for the effect are almost certainly multiple, for example:
Although I’m a cognitive psychologist and consequently think that memory and cognition is mostly about your mastery of effective strategies, when it comes to age-related cognitive decline, I’m a big believer in the importance of diet and exercise. But while we know these things can play an important role in why some people develop cognitive impairment and even dementia as they age, and others don’t, we don’t yet know with any great certainty exactly what exercise programs would be the best use of our time, and what diet would have the most benefit.