Memory

by Len Horridge

Understanding memory

We don’t really understand memory yet. Even though there has been a lot of research into how we remember, there is still no universally-agreed model of the mind/brain and how memory works.

With this proviso, memory is best described as a way of accessing things we already know. If you want to understand why the techniques described in this topic may help you to do this more effectively, there are three basic questions to ask:

  1. How are memories formed? (encoding)
  2. How are memories retained? (storage)
  3. How are memories recalled? (retrieval)

The brain

The brain is the hub of the nervous system and is made up of 100 billion (approximately) nerve cells or neurones. Each cell is connected to 10,000 (or so) others through synapses, and it is these connections that create what has been termed a neural network.

Current studies in neuroscience strongly support the notion that a memory is a set of encoded neural connections. The stronger and more numerous the connections, the stronger the memory. Recollection of an event can occur as the result of a stimulus to any of the parts of the brain where a neural connection for the memory exists. If part of the brain is damaged, access to any neural data contained there is lost.

A popular model of memory

One of the most popular models of memory sees it as a present act of consciousness, reconstructive of the past, stimulated by a retrieval cue. The cue is matched to the engrams, or memory fragments, that are encoded into the neural network. Once a match is found, any other connected fragments also become available.

Memories might better be thought of as a collage or a jigsaw puzzle than as whole tape recordings, pictures or video clips. On this model, perceptual or conscious experience does not record all sensory data experienced. In fact, most sensory data is not stored at all. For example, we do not store the feel of our clothes on our body unless there is a specific reason to. We are flooded with HUGE amounts of sensory data every second, and store only a minute proportion of it.

What IS stored are bits and fragments of experience, encoded in engrams. Exactly how they are encoded is not completely understood, but a heightened emotional intensity at the time of the event seems to promote more encoding, and thus a more complete and stable encoded record of the event.

When a memory is recovered, it is actually a present moment reconstruction which is composed of the fragments of what was encoded. These are then filled in with other generic fragments until a coherent whole is created. It is this reconstruction that is made available to the conscious mind and is taken as a full and true memory. This explains the differences in testimony between different witnesses to the same event.

To date, the best research on this has been done by Karl Pribram, who believes that the brain acts as a holographic instrument which is able to take bits of information and construct the whole from these fragments.

Forgetting

If we use the model described in the previous paragraphs, forgetting is due to one or more factors:

  • Weak encoding (which is why we forget most things, including our nightly dreams)
  • Lack of a retrieval cue (we seem to need something to stimulate memory)
  • Time and the event’s replacement in the neural network by later experiences (how many experiences do you remember from many years ago?)
  • Repetitive experiences (you’ll remember the one special meal you had at a special restaurant, but you won’t remember what you had for lunch a year ago Tuesday)
  • A drive to keep us sane (imagine the brain overload that would occur if we were to never forget anything).

The advantage of a bad memory is that one enjoys several times the same good things for the first time.

Frederick Nietzsche

Most lost memories are lost because they were never elaborately encoded in the first place. The chances of remembering something improve with consolidation, which creates strong encoding. Thinking and talking about an experience enhance the chances of remembering it by repeatedly strengthening the encoding.

Accuracy of memory

How accurate and reliable is memory?

Studies on memory have shown that we often construct our memories after the fact; in other words, we are susceptible to suggestions from others that help us fill in the gaps in our memories. That is why, for example, a police officer investigating a crime should not show a picture of a single individual to a victim and ask if the victim recognises the assailant. If the victim is then presented with a line-up and picks out the individual whose picture the victim had been shown, there is no way of knowing whether the victim is remembering the assailant or the picture.

Another interesting fact about memory is that studies have shown that there is no significant correlation between the subjective feeling of certainty a person has about a memory and the memory being accurate.

Also, contrary to what many people believe, hypnosis does not aid memory’s accuracy. Because subjects are extremely suggestible while hypnotised, most legal systems do not allow as evidence in a court of law testimony made while under hypnosis. Studies have shown that subjects may remember more under hypnosis, but that they also make more errors.

When I was younger, I could remember anything, whether it had happened or not.

Mark Twain (1835–1910)

Furthermore, it is possible to create false memories in people’s minds by suggestion – even false memories of previous lives. Memory is so malleable that we should be very cautious in claiming certainty about any given memory without corroborative evidence.

Many people have the experience of thinking they remember a specific event from childhood, only to discover later that it never happened and was a fabrication based on an often repeated story, or a collage of events.