Donald Broadbent, an intimidating tutor and later a scary boss, used to describe how once, when shutting up his house for the night, he carefully set a lettuce on the doorstep for the milkman and put the milk bottles in the rabbit hutch. Also when, going to his bedroom to dress to go out, he found himself in bed in his pyjamas (He was a shy man who did not much enjoy social occasions). These are just the kinds of slips that comedians attribute to failing memory in old age but desuetude was not his problem. To the great sadness of all who knew him, he died long before his brilliance dimmed. His slips of action were probably due to intense preoccupations with much more interesting things than milk-deliveries, famished rabbits or the prospect of a boring evening
While working in Manchester I was lucky to be a colleague of Jim Reason, a world expert on how human errors cause dramatic aircraft accidents, failures of nuclear power stations and cardiac surgery but also small glitches in ordinary domestic lives .1 As part of this research he developed a “Slips of Mind” questionnaire that had identified individuals whose everyday lives had become particularly error-prone such as women experiencing problems of menopause or patients undergoing chemotherapy. To test the folklore that the older we get the absent-minded and unreliable we become we gave this questionnaire to our Manchester volunteers to check what they had to tell us about their own experiences of absent-mindedness.
The results troubled Jim because though his questionnaire had reliably picked up differences between many groups of people our volunteers’ reports of their everyday errors did not increase with age or reduce with higher intelligence. Scores on his questionnaire were also unrelated to scores on simple laboratory memory tests. We were less puzzled because this had become a familiar result in our laboratory and in the general literature on mental ageing. As people grow old most do not report making more memory errors. People of all ages, but perhaps especially if they are old, tend to be diffident about their own abilities if they are depressed 2 but, surprisingly, differences in their ages or intelligence test scores or on objective memory tests do not seem to affect their confidence in themselves one way or another.
One reason is that we have no absolute standards against which to judge our mental abilities. We can only compare ourselves against others, or against the demands that our lives make of us. If we share demanding jobs with extraordinarily able colleagues, or if we live with formidably competent partners, we are likely to become pretty humble about our competence. If we are lucky enough to be surrounded by less competent people we can become overweening. Age does not just affect our brains and so our mental abilities; it alters our daily lives. As we grow older our lives become less demanding and more predictable; routines and habits become simpler and more reliable; there are fewer observers to bring our lapses to our attention and perhaps those that remain have become used to us, and have grown more lenient. Our slips are mostly unimportant and leave no scars on our relationships or our memories. The complacency with which the oldest volunteers answered Jim’s excellent questionnaire simply means that, unlike the exceptional young people he had studied, they were never tested by demands to run nuclear power stations, fly aircraft, drive trains, be responsible for safety on oil rigs, manage complex surgical procedures or care for demanding young families.
If we are lucky our lapses may amuse rather than exasperate our families and friends but there is some evidence that, in general, young adults regard slips by older people as sad signs of mental decline while older people are more sympathetic with each other’s lapses and do not regard them as being omens of irreversible and malign change 3.
One exception to the tolerance of the young is that they may find it hard to suppress irritation when we repeat a comment, or a story many, many times, or forget that we have already taken our daily medicine and overdose by having more. Asher Koriat and his colleagues pointed out that this highlights a distinction between remembering things that are said to us or happen to us (“input monitoring” ) and things that we ourselves have done or said (“output monitoring”)4. They compared how well old and young adults remembered words that they were asked to remember (input monitoring) and other words that they had categorised as being, for example, the name of a living or inanimate thing (“output monitoring”). Older volunteers were worse at remembering words about which they had made decisions than those that they had intended, and tried, to remember. Perhaps this is the key: an active decision to remember improves recall more than simply having to do something about a word or event without feeling any obligation to later recall it. Gill Cohen and Dorothy Faulkner expanded this theme by showing that older people are quite poor at remembering things that they themselves have done and even confuse these with memories of things that they had only thought of doing 5. As often, T.S. Eliot got it first : ”between the act and the intention there falls the shadow”.
A key is that memory is more about prediction than reminiscence. Our memories of the past may be pleasant, interesting or distressing but, without them, we would be at a loss to anticipate our tomorrows or plan ahead to manage or avoid future events. Suzanne Corkin touchingly illustrates this in the first paragraph of her account of the famous neuropsychological patient, Henry Molaison6 who, during more than twenty years after bi-lateral damage to his hippocampus could never again remember what had happened more than ten minutes ago. When asked what he would do tomorrow he replied, with characteristic good nature “whatever is beneficial”. Without any guide from his yesterdays he could anticipate nothing about his tomorrows. As Sue implies by the title of her book he lived in a “Permanent Present Tense” without a past or future.
Older people become keenly aware that memory is about prediction and planning when we find ourselves standing baffled in a room we have just entered trying to remember what we meant to do in it. We have successfully initiated a plan but, halfway through it, have forgotten the goal. Often we fail to resolve this dilemma and do whatever we most often do in that particular location – like Donald Broadbent who successfully got to his bedroom to dress but was sidetracked by his bedtime routine. My colleagues refer to this aspect of memory for the future as “prospective memory” and study it in laboratory tasks in which volunteers are asked to break off activities at specified moments to do something else – such as checking the time on a clock – or to change activities when some particular event occurs. It will not surprise many of us to hear that we become less good at both these kinds of tasks than when we were young but there is encouraging evidence that our failures force us to find new ways of coping that they young do not yet need and so have not yet discovered. Elizabeth Maylor asked elderly Manchester volunteers to telephone her at specified times and found that some of them did this remarkably efficiently, but apparently only because they found elaborate ways to cue themselves – such as piling up furniture about the table on which they kept their telephone 7 . Obviously those who have simple fixed routines into which they can build reminders to trigger any plans that they make have an advantage over others, especially the busy young, who have chaotically unstructured lives. Difficulties in coping are greater for people with such considerable memory losses that they lose track of even comfortably predictable routines and cannot remember to use even simple memory aids. For them new technologies can provide solutions; from electronic diaries providing alerts to do things at particular times to permanent connections with manned “control centres” from which health professionals continuously monitor, update and steer them through their days.
It is alarming to think how easy it has become for our memories to move outside our heads to vast server farms in which our lives, our plans and so our aspirations and hopes can be stored long after we have any use for them. Wearable devices such as miniature cameras already document the patrols and encounters of policemen and soldiers. Devices, such as Google Glasses can already provide very accurate and complete, but numbingly tedious permanent records of entire existences that expand and contradict the dim biological traces on which we depend. This may not do any more for us than the vast collections of un-inspected digital photographs and sound recordings that we already have. I am not excited by these possibilities and do not look forward to spending my last days like Beckett’s sad Krapp, obsessionally playing over his Last Tape, or editing my external electronic memory. No more than I presently feel the need to get my digital photo collection in order at long last. The possibility of having an external virtual memory of remorseless precision and infinite capacity only highlights the advantage of the limited, fuzzy, unreliably self-edited biological record from which I have constructed the little life story with which I have become content. Again Eliot is fast on the ball “Human beings cannot bear too much reality”. Or too much unreality if memory hacking becomes feasible and horrible electronic crimes begin to be committed against our natures.
It may be that if I had an external memory I should be less tedious company because alarms would go off when I once again tell the same story or use the same dull phrase. My patient family would no longer be irritated by my sudden pauses in the kitchen, bewildered whether I came in to make a sandwich, get a drink, check the dishwasher or move on to the lavatory next door. If this happens I shall have lost control of the dimming and fallible recollections that are all that I have with which to work out what it is to be human. I shall become a biological appendage to a huge computer in some other continent. The natural decay of my memory, like a pile of autumn leaves, briefly and gorgeously discolouring as they compost into rich undifferentiated tilth, is a far, far better fate.
- Reason, J. (1990).Human error. Cambridge university press.
- Rabbitt, P., & Abson, V. (1990). ‘Lost and Found’: Some logical and methodological limitations of self‐report questionnaires as tools to study cognitive ageing.British Journal of Psychology, 81(1), 1-16.
- Bieman-Copland, S., & Ryan, E. B. (1998). Age-biased interpretation of memory successes and failures in adulthood.The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 53(2), P105-P111.
- Koriat, A.Ben-Zur, H., & Sheffer, D. (1988). Telling the same story twice: Output monitoring and Age. Journal of \memory and Language, 27, 23-39.
- Cohen, G., & Faulkner, D. (1989). Age differences in source forgetting: Effects on reality monitoring and on eyewitness testimony.Psychology and Aging, 4(1), 10.
- Corkin, S. (2013).Permanent present tense: the unforgettable life of the amnesic patient (Vol. 1000). Basic Books.
- Maylor, E. A. (1990). Age and prospective memory.The Quarterly Journal of Experimental Psychology, 42(3), 471-493.