What is memory? 

One simple definition of memory that makes sense to patients, families and carers is: “Memory is the ability to take in, store and retrieve information”. Although people tend to talk about memory as if it were one skill or function or ability, saying, for example “I have a terrible memory” or “she has a photographic memory”, there are in fact many kinds of memory and many ways it can be classified.

We can consider memory in terms of the length of time for which memories are stored; the type of information to be remembered; the modality the information is in; the stages in the process of remembering; explicit or implicit memory; whether recall or recognition is required; whether the memory is retrospective (for things that have already occurred) or prospective (remembering what has to be done) and whether the memory dates from before or after an injury or illness.

Memory problems are common 

Memory problems are common after many kinds of insult to the brain: particularly traumatic brain injury, encephalitis, stroke or Alzheimer’s Disease. Although at present there is no effective way to restore lost memory functioning, we can help people to compensate for their problems and to learn more efficiently.

For those with very severe and widespread cognitive difficulties it may be that the best we can do is to modify or structure or rearrange the environment to help them manage without using memory. 

How can we help those with memory difficulties? 

Although restoration of memory functioning to pre-injury levels is unlikely to occur, there is a considerable amount that can be done to enable memory-impaired people and their relatives to come to terms with their difficulties and surmount a number of them by using various strategies and aids. Compensatory memory aids may encourage a degree of independence. These include diaries, notebooks, tape recorders, mobile phones and voice assistants, which are widely used by the general population but are often problematic for memory-impaired people simply because their successful use involves memory.

However, use of these aids is possible through carefully structured teaching. Another group of strategies we can use in rehabilitation for memory impairment are those which enable people to learn more efficiently. Spaced retrieval, vanishing cues and errorless learning together with mnemonics and rehearsal techniques can be employed to teach new information. Errorless learning is more effective than trial-and-error learning for memory-impaired people. This is because, in order to benefit from our mistakes, we need to be able to remember them. This is difficult or impossible for memory-impaired people. In the absence of episodic memory, making an error may strengthen or reinforce the erroneous response.  

Encoding, storage and retrieval 

In order to remember anything we have to encode it (take it in), store it and retrieve it when needed . We can help with each of these stages too. We can improve people’s ability to encode information by: 

1. simplifying material
2. reducing the amount of information provided 
3. checking that the material or information has been understood 
4. encouraging associations or links 
5. following the little-and-often rule
6. promoting organisation  
7. avoiding trial-and-error learning  

We can help improve storage by testing for retention and by having the memory-impaired person rehearse and practice the material he or she is trying to remember at regular intervals. Expanding rehearsal (also known as spaced retrieval) is a useful method here too, as are other rehearsal and learning strategies. All may lead to better storage. To help with retrieval, we can avoid context-specific learning by teaching information in several different settings. Sometimes first-letter cues are helpful as they are good retrieval cues, but this is of limited value in real life unless the person can systematically go through the alphabet to identify the correct letter. 

Mental retracing is another way of retrieving information but difficult for people with memory problems. Nevertheless, this is a ‘normal’ and popular strategy reported as being used by some of those with memory impairment. In addition to poor memory, many brain-injured people will have other cognitive problems which need to be addressed. The emotional consequences of memory impairment such as anxiety, depression and loneliness should also be addressed in rehabilitation through counselling, anxiety-management techniques and treatment in memory or psychotherapy groups.      

In conclusion, it is possible to reduce the everyday memory problems of survivors of brain injury and help them return to their own most appropriate environments. 

Further reading

Wilson B.A (2009) Memory rehabilitation: integrating theory and practice New York; Guilford Press 

Wilson B.A and Betteridge S Essentials of Neuropsychological Rehabilitation New York: Guilford press 

About the author

Barbara Wilson qualified as a clinical psychologist in 1977 and since 1979 she has worked in Brain Injury Rehabilitation, first at Rivermead Rehabilitation Centre in Oxford, then at Charing Cross Hospital, London and at The University of Southampton Medical School. Since 1990 she has been employed as a Senior Scientist at The Medical Research Council’s Cognition and Brain Sciences Unit, Cambridge.