MEMORY is the glue — the cohesive force — that holds together the various aspects of our mental life. Regardless of age, healthy people can experience memory distortion or loss.

In his book,

The Seven Sins of Memory, How the Mind Forgets and Remembers, memory researcher Daniel Schacter describes seven common “sins” of memory. They include three sins of omission: transience, absentmindedness and blocking; and four sins of commission: misattribution, suggestibility, bias, and persistence.

Some of these memory flaws become more pronounced with age. However, unless they are extreme and persistent, they are not considered indicators of Alzheimer’s disease or other memory-impairing illnesses.

TRANSIENCE

This is the tendency to forget facts or events as time passes. A person is most likely to forget information soon after it is learnt. Memory has a “use it or lose it” quality, that is, memories that are recalled and used frequently are least likely to be forgotten.

Some neuroscientists regard transience as beneficial because it clears the brain of unused memories, making way for newer, more useful ones.

ABSENTMINDEDNESS

This occurs when close enough attention is not paid to facts. For example, you forget where you just placed your car keys because you did not focus on where you put them in the first place. Perhaps, you were thinking of something else (or maybe nothing in particular), so your brain did not encode the information securely.

BLOCKING

Has this ever happened to you? Someone asks you a question and the answer is right on the tip of your tongue; you know that you know it, but you just cannot think of it. This tip-of-the-tongue experience is perhaps the most familiar example of blocking, the temporary inability to retrieve a memory.

Blocking does not occur because of lack of attention or because the memory you are looking for has somehow disappeared from your brain. It occurs when a memory is properly stored in your brain, but something is keeping you from finding it. What has happened is that a different but related blocking memory pops into consciousness, impeding access to the required memory.

MISATTRIBUTION

Let us say that you have been asked “Who is John Smith?” You remember quite clearly not only who he is, but also that lately he has been in the news. Then you are asked where you learned these details. You think for a moment and reply that you heard about him on the morning news. However, there was no report about John Smith on the news. Instead, you got your information from the friend you had dinner with on the previous day.

So this is a case of right memory, wrong source.

Misattribution occurs when you remember something accurately in part, but misattribute some detail, for example the time, place or person involved. Misattribution happens to everyone. It is usually harmless, but can have profound consequences, particularly in the criminal justice system.

Misattribution, like many other memory problems, becomes more common with age.

As you age, you absorb fewer details when acquiring information because you may have more trouble concentrating. Additionally, as you grow older, your memories grow older as well.

SUGGESTIBILITY

Imagine that you saw a man running away from a woman who had just been robbed of her cellular phone. You did not get a good look at the thief, but another person on the street insisted that the thief was a man wearing a red plaid shirt. Later, when the police show you photographs of possible suspects, you are confused until you see a man dressed in red plaid shirt. Then you point him out as the thief.

Suggestibility refers to false memories that you develop because someone or something gives you some key information at the same time that you are trying to retrieve a memory. The suggestion fools your mind into thinking it is a real memory.

Suggestibility is the “offender” in memories that adults have of incidents from their childhood that never really happened.

BIAS

Our attitudes and preconceived notions bias our memories – filtering reality. Biases affect memories when they are being encoded in the brain and when they are being retrieved.

Bias can affect all sorts of memories, but among the most interesting examples are people’s recollections of their romantic relationships.

In one study, couples who were dating were asked to evaluate themselves, their partners and their relationships, initially, and then two months later. During the second session, participants were asked to recall what they had said initially. The people whose feelings for their partners and their relationships had become more negative, recalled their initial evaluations as more negative than they really were.

On the other hand, people whose feelings for their partners and their relationships had become more loving recalled their initial evaluations as more positive than they really were.

PERSISTENCE

The persistence of memories about traumatic events, chronic fears and negative feelings is another form of memory problem. Some of these memories accurately reflect horrifying events, while others may be negative distortions of reality. These are many memories that we wish we could erase, but somehow cannot.

People who are suffering from depression and post-traumatic stress disorder (PTSD) are especially prone to having persistent, upsetting memories. Research has shown that depressed people are given to ruminating over unpleasant events in their lives or mistakes that they believe they have made which in turn fuels a vicious cycle of increasing depression.

Flashbacks, persistent, intrusive memories of a traumatic event, are a core feature of PTSD.

Dr. Jacqueline E. Campbell is a family physician, university lecturer and pharmacologist. She is the author of the book A patient’s guide to the treatment of diabetes mellitus. Email: drjcampbell14@yahoo.com