forgetting

Variety is the key to learning

On a number of occasions I have reported on studies showing that people with expertise in a specific area show larger gray matter volume in relevant areas of the brain. Thus London taxi drivers (who are required to master “The Knowledge” — all the ways and byways of London) have been found to have an increased volume of gray matter in the anterior hippocampus (involved in spatial navigation). Musicians have greater gray matter volume in Broca’s area.

References: 

Kwok, V., Niu Z., Kay P., Zhou K., Mo L., Jin Z., et al. (2011).  Learning new color names produces rapid increase in gray matter in the intact adult human cortex. Proceedings of the National Academy of Sciences.

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Forgetting a skill or procedure

  • Memory for skills — procedural memory — is stored as action sequences, in our unconscious memory.
  • Because this type of memory is very reliable, failures are usually particularly puzzling and even distressing.
  • Because the memory is less accessible, we also tend to have problems dealing with failures.
  • Failures occur when an action sequence becomes disrupted for some reason. When this happens, we have to retrieve the knowledge stored in our conscious memory, that we used when learning the skill.

Have you ever been driving a car and suddenly you’re not sure what to do? You’re traveling along in usual automatic fashion and there comes a moment when you need to engage a new subroutine — say, you need to give way at an intersection, or you stall at the traffic lights, or you stop the car — and suddenly, you don’t know what to do. There’s a flash of panic, even while you’re thinking, “This is stupid, I’ve done this a thousand times”, and then, maybe it’s all right, maybe you have to take a moment to get your head in the right space, and ... okay, you’re off again, control safely in the hands of the automatic pilot.

But you’re unsettled. There are lots of ways our memory fails us. Some of these are very common, so common we just accept them — noone (well, few of us) expect our memories to be 100% perfect all the time. But procedural memory — the memory that allows us to drive a car, ride a bike, type, play the piano, etc — is different from other types of memory. We don’t say “it’s like riding a bicycle” without reason. Once we’ve truly mastered a skill, we expect to have that, for ever. And, for the most part, we do.

The thing about procedural memory — the big difference between it and so-called declarative memory — is that it is not in conscious memory. That’s its huge advantage; we could never perform skills fast enough if they were under conscious control. As we acquire a skill, the declarative information we learn (‘use your little finger on the “a”; the “s” is next to the “a”; the “d” is next to the “s” ’ etc) is transformed into so-called “procedural rules”, which are completely internalized, beyond our conscious manipulation. This greatly reduces the involvement of working memory, and protects the skill from the types of interference that other types of memory are vulnerable to.

It also means that when we do have a failure, we really don’t know how to deal with it. A conscious mental search is not going to retrieve the needed information, because the information we want is not in our accessible database. So what usually happens is that we are forced to default to our backup — the declarative information we encoded during the original learning process. It is this that accounts for the lack of fluency in the subsequent actions; to regain fluency, you must engage the unconscious action sequence.

I don’t know of any research that has looked into these occasional glitches, but I presume that what happens is that the action sequence doesn’t immediately engage. As soon as it doesn’t, we pay attention — that makes it even more likely that the action sequence won’t be triggered, because conscious awareness is precisely what we don’t want.

One piece of research that is relevant to this is a recent study that looked at the phenomenon of “choking” — top athletes performing below par at crucial moments. It’s suggested that the problem lies in part in the athlete paying too much attention to what they’re doing. Skills are the one area of memory where too much attention is deleterious to performance!

I think the best way to deal with this very occasional glitch in performance is to relax, stop thinking about what you’re doing, go back a little in the action sequence to an obvious starting point (if you can’t or don’t need to physically re-do earlier steps, mimic the steps). Remember that skills are stored as sequences, and it’s hard to break in halfway through a sequence, you need to start at the beginning.

You can read more about skill memory and about the best way to practice.

You might also be interested in a related (but separate) issue, that of action slips, which are a product of a lack of attention, not a surfeit.

This article originally appeared in the November 2004 newsletter.

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Forgetting to do things

  • Forgetting future tasks and events is the most common type of memory failure
  • Older adults are in general no worse at this type of remembering than younger adults
  • Older adults may have more difficulty at remembering to do actions at particular times
  • Older adults also need to make more effort in situations when an action cannot be performed immediately, but must be held in memory for a brief period.

The other day I was sitting in the sunshine in my living room going through some journal articles I'd photocopied. I realized I needed to staple the pages together and went down to my study to get the stapler. Approaching my desk, I decided to check my email while I was there. And then, I decided to check my library account online to see whether a book I had requested had turned up. When I'd done that, I went back upstairs to my papers. Where I realized, of course, that I'd forgotten the stapler.

This type of memory failure — going to do something, getting sidetracked, doing something else and forgetting the original task — is familiar to all of us. As are everyday memory failures like forgetting to put the garbage out; forgetting to take medication at the right time; forgetting a dentist appointment (although there's more than one reason for that!).

This type of memory failure — forgetting the future, as it were — is a failure of a type of memory called prospective memory, and it is probably the most common type of memory failure older adults suffer from. And probably the biggest concern.

It's a concern because it's a failure of memory that has consequences, and those consequences are often not only obvious to ourselves, but also to others. Which makes us feel worse, of course.

But it's not just a matter of being embarrassed. Older adults are particularly vulnerable to thoughts that they are "losing" their memory — and the fear of Alzheimer's lurks in all of us.

So, should you be worried if you forget what you're doing?

Like other types of forgetting or absent-mindedness, it depends on the degree of your forgetfulness. But prospective memory failure is common among older adults for a very good reason. Not because it's a precursor of cognitive impairment, but because it's the most common type of memory failure for everyone.

In fact, older adults in general are no worse than anyone else in this particular memory domain, although they may worry about it more (because they worry about any memory failure more).

In some aspects of prospective memory, older adults are actually better than younger adults! One reason for this is that they are more likely to use memory aids — like writing down reminders, or putting reminder objects in strategic places — to help them remember.

However, it does seem that older adults may do less well at remembering things that have to be done at particular times, and one reason for this seems to be that they tend to be poorer at monitoring time. In these cases, it's therefore a good idea to use timers as reminders.

Older adults also seem to have more trouble in the situation when a remembered intention cannot be performed immediately, but must be held in memory for a brief period. Even 5-10 seconds is too long! Tasks that you are "just about" to perform, but in fact are not doing that very second (because you have some other intervening task to do first) are probably particularly dangerous because you don't feel a need to make an effort to remember them (because you are "just about" to do it). But without rehearsal, information falls out of working memory (the stuff we're holding in the conscious "forefront" of our mind) in seconds. So you do need to make an effort. And often, that's all it needs.

You can read more about planning memory strategies in my ebook on planning memory.

 

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Multitasking

  • Doing more than one task at a time requires us to switch our attention rapidly between the tasks.
  • This is easier if the tasks don't need much attention.
  • Although we think we're saving time, time is lost when switching between tasks; these time costs increase for complex or unfamiliar tasks.
  • Both alcohol and aging affect our ability to switch attention rapidly.

A very common situation today, which is probably responsible for a great deal of modern anxiety about failing memory, is that where we're required to “multitask”, that trendy modern word for trying to do more than one thing at a time. It is a situation for which both the normal consequences of aging and low working memory capacity has serious implications.

There’s an old insult along the lines of “he can’t walk and chew gum”. The insult is a tacit acknowledgment that doing two things at the same time can put a strain on mental resources, and also recognizes (this is the insult part!) that well-practiced activities do not place as much demand on our cognitive resources. We can, indeed, do more than one task at a time, as long as only one of the tasks requires our attention. It is attention that can’t be split.

You may feel that you can, in fact, do two tasks requiring attention simultaneously. For example, talking on a cellphone and driving!

Not true.

What you are in fact doing, is switching your attention rapidly between the two tasks, and you are doing it at some cost.

How big a cost depends on a number of factors. If you are driving a familiar route, with no unexpected events (such as the car in front of you braking hard, or a dog running out on the road), you may not notice the deterioration in your performance. It also helps if the conversation you are having is routine, with little emotional engagement. But if the conversation is stressful, or provokes strong emotion, or requires you to think … well, any of these factors will impact on your ability to drive.

The ability to switch attention between tasks is regulated by a function called prefrontal cortex. This region of the brain appears to be particularly affected by aging, and also by alcohol. Thus, talking on a cellphone while driving drunk is a recipe for disaster! Nor do you have to actually be under the influence to be affected in this way by alcohol; impaired executive control is characteristic of alcoholics.

More commonly, we get older, and as we get older we become less able to switch attention fast.

The ability to switch attention is also related to working memory capacity.

But multitasking is not only a problem for older adults, or those with a low working memory capacity. A study [1] using young adults found that for all types of tasks, time was lost when switching between tasks, and time costs increased with the complexity of the tasks, so it took significantly longer to switch between more complex tasks. Time costs also were greater when subjects switched to tasks that were relatively unfamiliar.

Part of the problem in switching attention is that we have to change “rules”. Rule activation takes significant amounts of time, several tenths of a second — which may not sound much, but can mean the difference between life and death in some situations (such as driving a car), and which even in less dramatic circumstances, adds appreciably to the time it takes to do tasks, if you are switching back and forth repeatedly.

To take an example close to home, people required to write a report while repeatedly checking their email took half again as long to finish the report compared to those who didn't switch between tasks!

In other words, while multitasking may seem more efficient, it may not actually BE more efficient. It may in fact take more time in the end, and the tasks may of course be performed more poorly. And then there is the stress; switching between tasks places demands on your mental resources, and that is stressful. (And not only are we poorer at such task-switching as we age, we also tend to be less able to handle stress).

There is another aspect to multitasking that deserves mention. It has been speculated that rapid switching between tasks may impede long-term memory encoding. I don’t know of any research on this, but it is certainly plausible.

So, what can we do about it?

Well, the main thing is to be aware of the problems. Accept that multitasking is not a particularly desirably situation; that it costs you time and quality of performance; that your ability to multitask will be impeded by fatigue, alcohol, stress, emotion, distraction (e.g., don’t add to your problems by having music on as well); that your ability will also be impaired by age. Understand that multitasking involves switching attention between tasks, not simultaneous performance; and that it will therefore be successful to the extent that the tasks are familiar and well-practised.

This article originally appeared in the February 2005 newsletter.

References: 

Rubinstein, J.S., Meyer, D.E. & Evans, J.E. 2001. Executive Control of Cognitive Processes in Task Switching. Journal of Experimental Psychology - Human Perception and Performance, 27 (4), 763-797.

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Short-Term Memory Problems

  • Short-term memory problems are, by and large, attention problems.
  • Attention involves both the ability to keep focused on the information you want to keep active, and the ability to not be distracted by competing and irrelevant stimuli.
  • You need to actively attend to keep information active, particularly as you get older.
  • Many of us over-estimate how much information we can keep active at one time.

Many people, particularly as they get older, have concerns about short-term memory problems: going to another room to do something and then forgetting why you’re there; deciding to do something, becoming distracted by another task, and then forgetting the original intention; uncertainty about whether you have just performed a routine task; forgetting things you’ve said or done seconds after having said or done them; thinking of something you want to say during a conversation, then forgetting what it was by the time it’s your turn to speak, and so on.

This is clearly an issue for many of us. Part of the reason, I believe, is simply that we expect too much from ourselves. For example, research has shown that even a very, very short delay between recalling an intention and being able to carry it out is sufficient to dramatically reduce the likelihood that you will remember to do the intended action — we are talking about a delay of only 10 seconds!

The problem is exacerbated by age (I’m not talking about advanced age — I’m afraid certain aspects of cognitive processing begin to decline as early as the 30s).

Part of the problem is also that we tend to believe that we don’t need to do anything to maintain a thought, particularly when it has “popped” into our minds easily. But current estimates are that unrehearsed information lingers in working memory for less than two seconds!

Some of these problems are dealt with in my article on action slips (these problems are not, strictly speaking, a failure of memory, but a failure in attention), and in my e-book on Remembering intentions.

But in this article I want to talk about another aspect: the relationship between working memory, and attention (and, as it happens, intelligence!).

In my article on working memory and intelligence I talk about the difference between crystallized and fluid intelligence — that fluid intelligence is probably a better measure of what we think of as “intelligence”, and that working memory capacity is often used synonymously with fluid intelligence. A new theory is that the relationship between working memory and fluid intelligence is due to the ability to control attention.

This theory emphasizes the role of attention in keeping information active (i.e. in working memory), and argues that working memory capacity is not, as usually thought, about the number of items or amount of information that can be held at one time. Instead, it reflects the extent to which a person can control attention, particularly in situations where there is competing information / demands.

I have to say that this makes an awful lot of sense to me. I can’t, in the space I have here, go into all the evidence for and against the theory, but here’s one situation which is interesting. The “cocktail party phenomenon” is a well-known method in psychology, whereby people are given two streams of audio, one for each ear, and instructed to listen only to one. At some point, the person’s name is spoken into the unattended stream, and about a third of people pick that up. In a recent take of that classic study, researchers compared the performance of people as a function of their working memory capacity. Only 20% of those with a high capacity heard their name in the unattended channel compared to 65% of low-capacity people. The point being that a critical aspect of good attentional control is the ability to block our irrelevant information.

This ability is one that we already know is worsened by increasing age.

The message from all this, I guess, is that:

  • short-term memory problems are, by and large, attention problems.
  • attention involves both the ability to keep focused on the information you want to keep active, and the ability to not be distracted by competing and irrelevant stimuli.
  • you need to actively attend to keep information active, particularly as you get older.
  • many of us over-estimate how much information we can keep active at one time.

And if you want strategies to help you keep more information active, I suggest you look at improving your ability to chunk, condense and label information. If you can reduce a chunk of information to a single label quickly, all you need to do is remember the label. (I explain all this at length in my book The Memory Key, but I’m afraid it needs far too much explanation to go into here).

Anyway, I hope this helps those of you (most of us!) with short-term memory problems.

This article originally appeared in the April 2005 newsletter.

References: 

Heitz, R.P., Unsworth, N. & Engle, R.W. 2004. Working memory capacity, attention control, and fluid intelligence. In O. Wilhelm & R,W. Engle (eds.) Handbook of Understanding and Measuring Intelligence. London: Sage Publications.

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Everyday memory problems

  • Frequent failures to retrieve information that should be readily accessible can generally be attributed to physical, environmental, and strategic reasons.
  • Physical reasons encompass health problems, lack of sleep, and stress.
  • Environmental reasons mainly concern how distracted you are.
  • Strategic reasons concern a failure to adopt effective memory strategies as situations and abilities change.

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.

Physical reasons for memory failure

Before looking at applying new strategies or making changes to your environment, you should first rule out the possibility that your memory difficulties are caused by health problems. To do this, you should consider whether memory failure is your sole symptom. If it is (and I have to say, I suspect this will rarely be true), then, fine, go straight to considering your environment and your habits. However, if you have other symptoms, however unrelated, then consider the possibility that your mental problems are part and parcel of some underlying physical dysfunction.

It may be something as simple as lack of sleep. In fact, considering how widespread the modern trend of not getting enough sleep is, I’d say look at that first. Don’t underestimate the importance of sleep in ensuring your brain is firing on all cylinders.

After sleep, I suggest you look at the other modern disease: allergies / sensitivities of various kinds. (I am assuming you don’t have a major health problem — presumably you would already be aware of this). If you suffer from these, you will have a raft of symptoms, possibly minor, but startling in their array if you stop and think about them.

For example, in my own case, I first considered food sensitivities because of serious fatigue. However, once I found the major offender (wheat), and realized that, indeed, food sensitivity was to blame, I listed all the various things “wrong” with me — things I was used to, that I just thought were how I was, such as achy joints. I filled a page with such ailments! (And, yes, to my complete astonishment, after having achy joints most of my life, I no longer get them now that I know the offending foods). My point is that if you’re suffering from food or chemical sensitivities, you will almost certainly suffer from multiple symptoms.

And, of course, the final modern disease is that old bugbear, stress.

I think it’s fair to say that adequate sleep, adequate exercise, and appropriate diet will ameliorate most of the “minor” physical ailments that impede memory (I hasten to add that I’m using “minor” only to distinguish such complaints from major disorders that require medical intervention).

I’m not saying that ensuring you eat right, sleep well, and exercise sufficiently, is easy! But don’t expect these things not to affect you, particularly as you age (and we’re not talking serious age, here; even in your thirties, you can’t get away with the complete disregard you may have shown in your twenties).

So much for physical causes. What about the environment?

Environmental reasons for memory failure

If you’re madly busy, if you’re having to keep many different things in mind, then you must expect this to take its toll on your mental resources, especially as you age. Don’t compare yourself to others — we are all different, and all have different capacities. Some people thrive on situations that would send another person to a hospital bed. You know yourself if you feel too stretched, if you’re juggling too many things, have too many responsibilities or too many people looking to you ... Don’t go by what you think you ought to be able to manage, go by what you can manage.

Strategic reasons for memory failure

And then there’s strategies. What you do to manage your life, your tasks, your memory needs. Most of us developed strategies for dealing with these matters early in life, when our mental and physical abilities were at their peak, when we had fewer complications in our lives. When these strategies begin to fail, most of us blame ourselves — that there is something “wrong” with us. In most cases, however, the fault is simply that the strategies were not particularly good ones. We got away with using them because we did not, at that point in our lives, require particularly effective strategies. Now we do. Accept that, and move on.

What to do

So, my advice to those of you suffering from this type of forgetfulness is to first consider whether your health is compromised or your capacities too stretched. Secondly (and whether or not these conditions are true), look for strategies that will relieve some of the burdens on your memory. Remember that, in today’s world, most of us put far more demands on our memory than has been the case at any previous point in human history. So don’t be afraid to use external aids to memory. Design your life, and build routines, that minimize the demands on your memory as best you can. And never take for granted that you will remember anything that you have made no deliberate attempt to remember.

You can find more specific advice for specific memory problems at:

Action Slips

Short-Term Memory Problems

Word-finding problems

Tip-of-the-tongue experiences

Multitasking problems

Forgetting a skill or procedure

This article originally appeared in the June 2004 newsletter.

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