A key component of any training exercise is the retention of new information. Trainees are exposed to facts and techniques which they are expected to apply in practical contexts. As human beings we make use of our brain’s ability to retain information for later use, but remembering something is very different from saving something to a computer flash drive. Yet many training programmes treat human memory exactly as if it were computer storage. In order to promote retention of information in trainees it’s important to understand some key facts about how our memory works and the ways we can apply that knowledge to become better at training in general.
Human memory is quite a marvellous thing. Without it we would be unable to learn or thrive. Our intelligence would be wasted without information to digest and, as a species, we would not survive long if we could not learn about the world and how it works.
The nature of our memory, the precise way in which it works, is still largely a mystery to us. However, we know quite a lot about how well (or badly) human memory performs and the various things that improve memory in general, but as with most of the brain it remains a black box that scientists are slowly teasing open.
As wonderful as human memory is, it’s also notable for how unreliable it can be. The work of Elizabeth Loftus (among others) has shown that not only is witness testimony a very poor form of evidence by itself, but that it’s possible to actually implant false memories.1 Through either conscious or unconscious manipulation (on the part of the manipulator) it is possible to make someone remember a fact or an event that is partly or completely fabricated. This includes making people remember and confess to crimes that they never actually committed.
Although we subjectively feel that our memories are highly reliable, the truth is that our perception of our own trustworthiness when it comes to remembering things accurately (or at all) doesn’t come close to matching the actual performance of that memory system. On the flipside of this we’ve seen memory abilities in some people that are far beyond anything we typically observe in humans. You’ve probably heard of the term “photographic” memory, usually in popular culture. The correct name for the related real-world idea is actually eidetic memory and it is a rare phenomenon. Eidetic memory, where it does occur, is mostly found in children and rarely in adults. People who exhibit eidetic memory can recall visual information with high accuracy after only being exposed to it for a short time. “Hollywood” photographic memory has no evidentiary basis in real life.2
Kim Peek, the man upon whom Dustin Hoffman’s Rain Man character was largely based3, had an incredible capacity for retaining facts, even in the form of seemingly raw data. Dates, names, number plates and just about any other listable fact could be recalled with near-perfect accuracy and made for someone who was essentially the grand master of trivia. Kim however, as is often the case in individuals who exhibit this sort of memory ability, had a below average IQ. He needed the lifelong care of his father in order to navigate the complexity of everyday life that most of us with normal memory ability take for granted.
This is just one clear indicator that having a very good memory does not correlate with any given level of intelligence. People with very high IQs may have great memory or merely average memory. There doesn’t seem to be a pattern. In the case of someone like Kim Peek it’s likely that his extraordinary memory was a byproduct of specific brain abnormalities that were also responsible for his below average IQ score. Neither of which seemed to affect his peerless personality, it should be said.
Failure is an Option
Psychologist Daniel Schacter holds that failures of memory can be divided into seven categories4; transience, absent-mindedness, blocking, misattribution, suggestibility, bias and persistence.Of these seven types of memory failure it’s generally only transience and absent-mindedness that have important implications for training. The latter, absent-mindedness, is a type of encoding error. In other words, at the point where the memory should have been “saved” or encoded something went wrong. In this case the absent-minded person was not paying attention whenever the salient event occurred. This is what happens when you absent-mindedly put your car keys or glasses down somewhere and then simply can’t remember where you put them.
It goes without saying that training needs to be designed in such a way that it catches and maintains the focus and attention of your trainees. This is one of the areas where using novel exercises or interactive multimedia aids can play a critical role, since you cannot retain information that was never encoded in the brain in the first place.The second important type of memory failure, transience, comes into play after a memory has been encoded. This is a phenomenon where memory fades or degrades over time.
The human brain is a very efficient housekeeper when it comes to memories. We don’t exactly know what the information capacity of the brain is, but it stands to reason that it isn’t infinite. The brain retains information that it deems important and discards information that serves no apparent purpose. Some have speculated that this consolidation of memory is one of the functions of sleep and may influence the experience of dreaming, but at the moment there’s no way to be completely sure.
In 2009 biochemist Kelsey Martin and his team became the first ever people to capture the moment a memory is formed at the cellular level.5 They observed a distinct difference between memories that were short-term and those that are long-term. Long-term memories are those with strong connections to other neurons (brain cells) that survive the constant pruning of unimportant synapses (the connections between one neuron and the next) so that they remain in a relatively stable network pattern. The key to memory retention in principle is therefore to strengthen the synaptic connections formed when that memory is first encoded. Every time that memory is called upon again or the same information is re-encoded the physical representation of that memory is strengthened and it becomes less likely that the brains housekeeping mechanisms will sweep it away.Of course, this and other views of how memory works are constantly being challenged. We’re still a long way from knowing precisely how the brain remembers.
There are a few ways in which really resilient memories are encoded. Events that are emotionally overwhelming and command an exceptional level of focus tend to immediately encode in a very strong way. People who suffer severe trauma, such as soldiers in times of war, can be saddles with memories that are so strong and vivid that they intrude into consciousness and cause those individuals to “relive” some of that traumatic experience. Which includes experiencing fear and anxiety again. This is commonly known as post-traumatic stress disorder or PTSD and most people with it recover completely from it within a few months, but some are unfortunate enough to be saddled with those vivid recollections for the rest of their lives, especially in the absence of treatment.
Of course, it would be neither ethical nor practical to use fear and anxiety as training mechanisms, although perhaps someone should point that out to teachers who seems to effectively use the fear of punishment or pain to motivate their students to learn. Positive emotions can however be used. By eliciting feelings such as delight, wonder or curiosity you can make it more likely that a memory will encode well by ensuring there is enough focused attention at play.6
The other (more practical) method is review and repetition. It’s probably not news to most people that learning something new once is hardly ever sufficient if you want to retain that information over the long-term. It’s also important that new information is associated with existing information that has already been mastered. If new information is interweaved with a memory structure or network that has solidified, it’s far less likely that this new information will be lost. Human memory is after all highly associative, which is why the use of mnemonics and other associative memory techniques work well to promote retention and recall.
It should be clear that the way that our memory works in incompatible with a “fire-and-forget” approach to training. If you present trainees with new information and then do not quickly move to strengthen and consolidate the relevant memory structures, that information will be forgotten. Few trainers would disagree that it’s important to actively support newly learned information, but the speed with which that information can be lost may come as a surprise to those who think weekly or even monthly training sessions are adequate.
Hermann Ebbinghaus, another psychologist who studied memory in the late 19th century, came up with a graphical plot detailing the results of self-experimentation with memory and recall. There have been various refinements and challenges to the details of the so-called “forgetting curve” over the last century, but the central observation still stands today. Unless you actively work to strengthen and maintain the new neural networks formed in the initial training session it will be rapidly lost.
How quickly are we talking about? The forgetting curve itself suggests that without any sort of rehearsal or review half of new information will be lost within an hour after training. Within a day seventy percent is gone and by the end of the first week you can say goodbye to ninety percent of the info.
This seems drastic, and it is, but remember we see this under controlled circumstances where no attempt to reinforce memory is made. These are also average figures. On an individual basis people may do much better (or worse), especially since there is some natural or incidental strengthening of memory as well. If the training material is especially compelling it will also improve the initial strength of the memories.
The forgetting curve is not some form of gospel that should be adhered to perfectly and it doesn’t apply on an individual basis. The point is to take a lesson from Ebbinghaus’ observations and understand the value of both encoding memory better and sustaining new memories until they are safely and properly lodged in long-term memory.
There are of course many things that can be done both at the design level, during training and through the use of post-training support to counteract the effect of the forgetting curve, but that’s a discussion for a different time.
In the meantime, ask yourself if you’ve observed the effects of the forgetting curve either in yourself or in trainees you’ve encountered. Have you been frustrated by being set back to square one as a trainer? Reflect on your practices when it comes to fostering retention or even measuring whether information has been retained at all.
In a later article we’ll come back to the issue of retention and discuss techniques at various levels of the training process that can mitigate and in some cases eliminate the negative effects of the forgetting curve.