We all know that memories can be unreliable and that this can vary depending on the person, the significance of the event, the time that has elapsed and a host of other factors. This is a serious issue in litigation, when the outcome of a trial – and in turn the fate of millions of pounds or an individual's liberty – can depend on the recollection of a key witness.
A recent Guardian piece on why memories can't be trusted notes that neurologists believe that a "memory" is not stored, like a file, in the form that it was remembered. Instead, when seeking to recall a memory, a person reactivates distributed clusters of cells and synapses spread throughout the brain that were involved in the original experience. Further, there is no evidence of the permanency of individual memories and, it seems more likely, a memory is reconstructed by the brain each time it is recalled – leading to it being different each time. Inevitably, this reconstruction is susceptible to manipulation from outside sources and memories – although recited in good faith – can change or be changed. A person's imagination and their creativity are likely to be activated at the same time as a "memory", and people are often unlikely to be able to distinguish between them. Indeed inaccurate eyewitness evidence is by far the leading cause of wrongful convictions in the US and, according to a New York Times article on the unreliability of memory in the courtroom, 75% of DNA-based exonerations have been related to cases where the witness was failed by their memory.
An interesting study has recently been undertaken by psychologists from the University of Waterloo in Canada, which demonstrated a strong correlation between drawing and memory retention. The study showed that if a person drew something, they were much more likely to remember it than writing it down or reading it out. The benefit appeared to have derived from the brain building a more elaborate set of connections in having to produce a drawing, which was then easier to recall. The study did not cover the recollection of past events but the strength of the correlation between drawing and memory makes it possible that there may be effective tools or techniques to help a person remember an event more accurately. It may be too early to start taking a whiteboard to Court, but memory training may become a feature of witness evidence in the future.