domains

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.

Why remembering to do things is so difficult

Remembering intentions is in fact much more difficult than remembering events that have happened, and the primary reason is the lack of retrieval cues. This is why, of all memory tasks, remembering to do things relies most heavily on external memory aids. Reminder notes, calendars, diaries, watch-alarms, oven-timers, leaving objects in conspicuous places — all these external aids are acting as cues to memory.

In partial compensation for the paucity of effective retrieval cues , planning memories are more easily triggered by quite marginal cues. Thus a friend of mine was reminded that her son’s friend would be spending Saturday night with them when she saw an advertisement for a movie about John F. Kennedy (the child’s father had the same initials: JFK).

Setting up effective cues

When we form an intention, we usually link it either to an event (“after we go to the swimming-pool, we’ll go to the supermarket”) or a time (“at 2pm I must ring Fred”). But these trigger events or times frequently fail to remind us of our intention.

This is often because the trigger is not in itself particularly distinctive. Your failure to remember to ring Fred at 2pm, for example, may be because you paid little attention to the clock reaching that time, or because there were other competing activities triggered by that same time signal.

Moreover, not all planning is linked to a trigger event or time. Quite a lot of planning simply waits upon an appropriate opportunity (“must buy some stamps sometime”). Such intentions usually need quite explicit cues. Thus, if I happened to see stamps on sale, I would probably remember my intention, but walking past, or even into, a shop that happens to sell stamps, may not be enough to trigger my memory.

On the other hand, I might keep being reminded of my intention when I am in the same context as when I originally formed the intention (when I am not in a position to carry it out!) — hence your increasing exasperation that you can never remember a particular intention when you can do anything about it.

Link the trigger and the intention

To deal with opportunistic planning, you should try to specify features of an appropriate opportunity. Thus, to remember to buy bread on the way home, you should think about what actions you need to take to buy the bread (for example, going a different route) and try to form a strong link between the trigger event and your action (“today when I get to the traffic lights I’ll turn left”).

A reminder of your intention is much less effective than being reminded of both the trigger event and the intended activity. Even being reminded of the trigger event is better than being reminded of the intention on its own.

To remind yourself to do something, focus on the trigger not the intent itself.

Don’t assume that because something is important to you, you will automatically remember it — somewhat to their surprise, researchers have found no evidence that personal importance has any effect on the likelihood of remembering to do something.

"I'm terrible at remembering names"

"I'm great with names, but I'm hopeless at remembering what I've read."

"I always remember what people tell me about themselves, but I'm always forgetting birthdays and anniversaries."

There is no such thing as a poor memory!

There will be memory domains that you are less skilled at dealing with.

Information comes in different packages

Think about the different types of information you have stored in your memory:

• the name of your dentist
• your PIN number
• the taste of chocolate
• the sound of train whistle
• the scent of a rose
• the feeling of fear
• the knowledge of how to drive a car
• your intention to pick up bread on the way home

etc etc.

Is it likely that these so-different types of information are stored in the same sort of codes in your brain? That they are processed in the same way? That the same types of cues will trigger recall?

No.

The concept of different memory domains is useful

The idea that there are separate memory systems for different types of information has been around a long while. While not all researchers agree on how many different domains there are, the idea of memory as a multimodal system has become respectable among cognitive psychologists. At a practical level, it isn't necessary for us to concern ourselves with the precise details of academic concerns regarding the nature of memory domains and how many there are. The idea of memory domains is a supremely useful one, for anyone wanting to improve their memory.

Different types of information require different memory strategies, and the idea of memory domains helps us match different strategies to different memory tasks. Knowing the principles by which we encode different types of information, we can understand which strategies will be useful.

Knowledge memory vs personal memory

One fundamental distinction that can be made is between your knowledge of "facts", and knowledge that is more personal.

Knowledge memory contains information about the world.

Personal memory contains information about you.

Within knowledge memory, separate domains may exist for numbers, for music, for language, and for stories. These are all types of information which appear to be dealt with in different ways.

Personal memory also contains a number of different domains:

Diagrams and table taken from The Memory Key

Autobiographical memory contains the information you have about yourself. It includes several domains:

• self-description (the source of a large part of your sense of identity), containing information such as:
  • whether or not you like ice-cream
  • what your favorite color is
  • what you think about a political party
• emotional memory, which not only contains our memories of emotional experiences, but also helps us control our moods. By dwelling on appropriate memories, we can sustain a mood. By recalling memories that involve a contrasting emotion, we can change a mood.
• event memory

Your memory for events

This is the largest component of autobiographical memory, containing three separate but related domains:

• memory for specific events that have happened to you
• memory for general events, which tells you the broad sequence of actions in events such as going to a restaurant or going to the dentist
• a potted summary of your life, which enables you to answer such questions as, “Where did you go to school?”, “Where were you working last year?”.

These may be thought of as being connected hierarchically:

Recalling specific events

Event memory is usually entered via the general-event level, although the information we are searching for is usually at the specific-event level. Thus, if you're trying to retrieve the memory of going to see the movie Titanic, you will probably start by accessing the general event "going to the pictures"

Specific events over time become merged into a general event - all the occasions you've been to the dentist, for example, have blurred into a generic "script", which encapsulates the key experiences and actions that are typical of the going-to-the-dentist event. After the specific event has become consolidated into the script, only distinctive events are likely to be specifically remembered. That is, events when something unusual/interesting/humorous happened.

The power of these scripts is such that people often "remember" details of a specific event that never happened, merely because they are typical of the script for that event.

Our memory for events reflects what we expect to happen.

It is perhaps because of this that unexpected events and new events (first-time experiences) are better remembered. If you don't have an existing script for the event, or if the event is atypical enough not to easily fit an existing script, then you can't mold the experience to your expectations.

The more distinctive an event - the more the event breaks with your script for that type of event - the better your memory for that particular event will be. (Failures to remember trivial events, such as where you’ve put something, or whether you’ve done something, are reflections of the fact that we pay little attention to routine actions that are, as it were, already scripted).

To remember an event therefore, you should look for distinctive details.

What makes a good cue for remembering events?

One of the most interesting areas of research in the study of event memory is a small set of diary studies. In one such study, a Dutch psychologist called Willem Wagenaar recorded his day's events every day for six years, noting down:

• who was involved
• what the event was
• where it occurred
• when it occurred

Wagenaar was hoping to discover which of these different bits of information were the best retrieval cues. At the conclusion of his study he reported that what was the best cue, followed by who and where. When was the least effective (have you ever tried to remember an event on the basis of its approximate date?).

There is nothing particularly special about these types of information however. Later, Wagenaar reanalyzed his data, and found that most of the difference in the memorability of these cues was due to their relative distinctiveness. Thus, the nature of the event is usually the most distinctive aspect of the event, and the people involved, and the location, are usually more distinctive bits of information than the date or time of occurrence.

To remember a specific event, we need a key - a unique feature that allows us to readily distinguish that event from similar events.

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.

One important difference between the idea of short-term memory and working memory, is that short-term memory was conceived of as a thing. Different from long-term memory (variously analogized as a library, a filing system, a computer) chiefly in the duration of the records it held. But working memory, as its name suggests, is now conceived more as a process than a thing. A state of mind. A pattern of activation.

Working memory contains the information of which you are immediately aware.

To put information into our memory store, it must ... be worked on - i.e., be held in working memory. To get information out of the memory store - to “remember” something - it must again be in an active state - be in working memory. How can we know what we remember if we're not conscious of it?

However, you can only keep something "active" for a very short time without your conscious attention. It is this which so limits working memory capacity.

The magic number seven

Probably the most widely known fact about working memory is that it can only hold around seven chunks of information (between 5 and 9). However, this tells us little about the limits of working memory because the size of a chunk is indeterminate.

1 2 3 4 5 6 7 are seven different chunks - if you remember each digit separately (as you would, for example, if you were not familiar with the digits - as a young child isn't). But for those of us who are only too well-versed in our numbers, 1 through to 7 could be a single chunk.

Recent research suggests however, that it is not so much the number of chunks that is important. What may be important may be how long it takes you to say the words (information is usually held in working memory in the form of an acoustic - sound-based - code). It appears that you can only hold in working memory what you can say in 1.5 — 2 seconds. Slow speakers are therefore penalized.

Your working memory capacity

What we term "working memory" contains several functions, including the "central executive" which coordinates and manages the various tasks needed. The extent to which working memory is domain-specific (different "working memories", if you like, for different sensory and cognitive systems, such as language, spatial memory, number) is still very much debated. However, at a practical level, we may think of working memory as containing several different components, for which you have different "capacities". Thus, your capacity for numbers may well be quite different from your capacity for words, and both from your capacity for visual images.

Difficulty in remembering people’s names is one of the most common memory tasks that people wish to be better at. And the reason for this is not that their memory is poor, but because it is so embarrassing when their memory lets them down.

This isn’t just an issue at a personal level. It’s a particular issue for anyone who has to deal with a lot of people, many of whom they will see at infrequent intervals. Nothing makes a person — a client, a customer, a student — feel more valued than being remembered.

But we have, in fact, a remarkably good memory for other people’s faces. Think about the ease with which you distinguish between hundreds, even thousands, of human faces, and then think about how hard it is to distinguish between the faces of birds, or dogs, or monkeys. This is not because human faces are any more distinctive than the faces of other animals. Think about how much harder it is for you to distinguish between the faces of people of an unfamiliar racial type.

Contrary to what many European-descended people believe, Asian faces are no less distinctive than European faces, but the differences between any human face are sufficiently subtle that they take a great deal of experience to learn. The importance of learning these subtle differences is shown in the way new babies focus on faces, and prefer them to other objects.

Our memory for other people is of course more than a memory for faces, although that part probably has the most impressive capacity. We also remember people’s names and various biographical details. We can recognize people by hearing their voice, at a distance by seeing their shape or the way that they move, or even by their clothing.

But it’s faces that give certainty.

Many years ago, when I was in my second year at university, I left the student cafeteria and nearly bumped into a young woman in a white lab coat. I murmured some sort of apology and started to move on, and she said my name. I stared at her blankly. She said, ‘You don’t recognize me, do you?’ Even with this prompt, I didn’t immediately get it. I still remember staring at her unfamiliar face, and then … the features seemed to shift under my eyes. It was very weird. Suddenly I knew her. I was mortified, and stunned. I hadn’t seen her in a year, but we’d been best friends all through high school. How could I not immediately recognize her?

Identity information is complex

Identity information is encoded in memory in quite complex ways. To more effectively use those codes, to improve your memory for names, faces, and important personal details, it helps to understand how identity information is recorded in memory.

There are three ways we can “recognize” a person:

• we might recognize them as having been seen before, without recalling anything about them
• we might identify them as a particular person, without recalling their name (“that’s a friend of my son’s”)
• we might identify them by name

If you think about it you will realize that you never, ever, recall information about a person without recognizing them as familiar. While this sounds terribly obvious, there is actually a clinical condition (the Capgras delusion) whereby a person, while recognizing the people around them, believes they have been replaced by doubles (imposters, robots, aliens). This is simply because the normal accompanying feeling of familiarity is missing.

You also never remember a person’s name without knowing who she is. This is because names are held in a separate place to biographical details, and can only be accessed through those details.

Identity codes and how they are structured in memory

Why is there this hierarchy? Why can we only access names through biographical information? Because identity information is ordered. Your memory for a person is not like this:

But like this:

In other words, there are several different kinds of identity information, and they are clustered according to type, and can in fact only be accessed in a particular order.

Of the various identity codes (bits of encoded identity information), there are three kinds that are important for recognizing a person:

• structural codes (physical features)
• semantic codes (biographical details, e.g., occupation, marital status, address)
• name codes

There is a fourth type of code that is useful for remembering unfamiliar faces:

• visually-derived semantic codes (e.g., age, gender, attributions such as “he looks honest/intelligent/sly”)

Semantic codes that are visually derived have an advantage over biographical codes, because the link with the structural code is meaningful and thus strong, whereas the connection between the structural codes and biographical details is entirely arbitrary. To say someone looks like a fox connects meaningfully with the person’s facial features, whereas to say that someone is a lawyer has no particular connection with the person’s face (to say someone looks like a lawyer would of course be meaningfully connected).

Visually-derived semantic codes are useful for remembering new faces because the link with the physical features of the face is strong and meaningful.

However you cannot identify a person without reference to the biographical codes.

The interesting aspect of these different codes is that you can only access them in a particular order:

When you recognize a face as familiar but can’t recall anything about the person, the physical features have failed to trigger the biographical details. When you identify a person by recalling details about them, but can’t recall their name, the biographical information has failed to trigger the name.

Whether the name is recalled therefore depends on the strength of the connection between the biographical details and the name.

In other words, to improve your memory for a person’s identity, you must strengthen the link between the physical features and the biographical information. To improve your memory for the person’s name, you must strengthen the link between the biographical information and the name.

Note: A fascinating account of what it is like to be face-blind, from a person with the condition, can be found at: http://www.choisser.com/faceblind/