Research shows stored memories are not static

By Sonia B. Glover

A lot of people think we can store an event in our memory and it will always be there; and that if we forget it, the exact memory is still there, but we just can't retrieve it at the moment.

According to research, however, this is not the case. In fact, our stored memories can change over time, and some may not be remembered at all.

Dr. Mark Howe of Memorial's Psychology Department is an expert on memory and has been doing research in the area for the past 15 years, focussing mainly on the development of long-term retention. In a recent interview with the Gazette, he said that his findings are beneficial to everyday life.

"I see memory, and anything that we learn about it, as fundamental to everything we do in life.  And, unfortunately, we see the effects of failing memory in patients with Alzheimer's  Disease.  Memory serves as a basis of how we think; the information that we have stored in our memory determines the types of solutions we arrive at for various problems. Our memory helps us with the simplest things like making a cup of tea."

Dr. Howe said research has discovered many important things about memory; a significant one being that our memory is re-constructive, not reproductive.

"When we are trying to remember an event, we are not necessarily remembering accurately, we are re- constructing it based on whatever fragments of our memory are left of that particular event . . . Our beliefs and values help guide us in this re-constructive process," He explained. "People re-construct their memories in different ways, depending what their needs are, which can lead to false memories."

He said this means the information that is stored in our memory is not static, like first thought.

"Some of the research that I have been doing shows that memory storage changes - what's in there can be altered and it's not there forever. So you may have had an experience that you could remember up to a particular time and all of a sudden you can't consciously remember it. It may not simply be that you can't get to it or retrieve it, maybe it's been altered, maybe it's been updated, or been overwritten by new information."

Dr. Howe said verbatim information fades rapidly from our memory and what remains is the meaning, and added that this is okay for being able to extract the jest of the memory and preserve the meaning of an event; however, it isn't good in terms of recalling details of an event.

This can spell trouble in some situations, such as court cases where memory evidence is used, added Dr. Howe, who is frequently called upon to give expert testimony about memory.

"This can be a problem for memory evidence in a courtroom and I worry in any case where memory is the only evidence because it can be fallible. We always have to be careful when we see evidence from memory, especially in abuse cases," Dr. Howe told the Gazette.

"Memory evidence is very powerful. It can convict or it can set free. It can be bad for a court case because it is not accurate to the degree that is typically needed forensically, but that doesn't mean that people can't give memory evidence that is forensically relevant, they certainly can . . . adults and children."

He pointed out that a situation surrounding memory evidence, such as how the information was solicited or how the person came to know the facts, is an important issue in the courtroom, especially when a young child is involved.

With continued funding support form NSERC, Dr. Howe is now studying early childhood memories and how they are retained over a lifetime. Earlier studies indicated we could remember our life events as far back as four or five years old, but recent studies now show that our memory goes back to the age of two.

So what happens before we are two years old? Is there no memory then?

"Our memory does not just kick in at the age of two; there is indeed a memory before then, but it's not what we call an autobiographical memory," Dr. Howe said. "What I mean is there isn't a memory  of an event that 'happened to me' sort of thing, and the 'me' is not an important part of the memory. At about the age of 18- 24 months, the 'self' becomes part of the memory," he explained further.

Dr. Howe is trying to find out what effect, if any, these early experiences have on later development in a child.

"We've already shown that we cannot remember consciously many of the experiences that happened to us, and some of them may not be there anymore, but if they are there, how do they affect us? So the issue isn't can we ever get back to them consciously because we know we can't, but instead we ask, what impact are these experiences having in childhood development, even though they are not remembering them?"

An important variable in memory is distinctiveness, said Dr. Howe.

"Distinctiveness covers both traumatic and non-traumatic experiences. A lot of people believe that traumatic memories are really memorable and that they can't be tampered with, but in fact they can.  Memory for all events, even important and traumatic events, can be altered in storage and even forgotten," he added.
 

Dr. Howe used neglected children in Romania as an example.

"What do all of these neglected Romanian children remember? Does this abuse have long term consequences even though they may not consciously remember the neglect? Is there
something that's retained that could be influencing their behavior in some way, shape or form?" Dr. Howe asked.

It's questions like these that Dr. Howe is trying to get answers to. He said now knowing that memory storage can be altered, many questions have surfaced.

Describing memory as  "much more complex than first thought", Dr. Howe said  he has some generalizations about which memories will end up being remembered over the long haul, but there's still a lot of work for him to do before making specific scientific predictions.

Dr. Howe said his research on memory will continue for many years yet, adding that it has been very rewarding and engaging.

So how would he rank it on a scale of one to 10?

"I love it, so I'd have to say 20! This is a process of discovery. You are learning new things and producing new knowledge about memory that is important to everyday life and to society… such as memory evidence in the courtroom. We could say our memory can be as important as a life and death situation," Dr. Howe concluded.

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