Our memory is integrally linked with forgetting.
Solomon Shereshevsky (1886-1958) is perhaps the most famous mnemonist of the twentieth century, and became a useful case study in how the brain remembers information. He could retain entire conversations, pages of printed text, blocks of random numbers--most anything that entered through his senses. So complete was his memory that he had to find ways of actually forgetting information so that he could create some order in his daily life. He had to teach himself how to filter out mundane information, writing down phone numbers, for instance, as a way to not remember. In order to effectively remember the things he needed to remember, in other words, he had to teach himself what to forget.
Shereshevsky’s memory and its impact on how we understand the human brain was studied over several decades by Russian psychologist Alexander Luria, and his theorizing about Shereshevsky’s condition (mostly agreed to have been synaesthesia) has contributed to the way we understand memory and learning. To state the description of his case in its most simple terms: Shereshevsky’s unusual condition is how most of our brains would work if we didn’t have the capacity to filter out information--what conventionally has been known as forgetting, or failing to remember. The skill he had to teach himself--consciously forgetting certain information--is what most humans do subconsciously. But we can benefit from his case because it shows us that we, too, can find ways to manipulate the filters that directly affect how we manage the information we want to recall. It is necessary to forget effectively, so that we can remember effectively.
Recent research has upended conventional notions about human memory, but has yet to make a significant impact on teaching and learning. The school of thought that has the most potential to shift our assumptions is what has been called a New Theory of Disuse. The theory is a revision of a century-old theory of disuse that still governs popular notions of memory. The old theory described forgetting as a degrading or erasure of a memory over time because of infrequent retrieval of the memory. The new school of thought (presented here in an early scholarly paper by Robert and Elizabeth Bjork) described forgetting as a problem not of actual loss, but of crowding out a memory with new information, combined with fewer retrievals. Memories don’t degrade, but rather our ability to retrieve them--a memory’s “retrieval strength”--has diminished. A quick video of Robert Bjork explaining this in more depth can be found among the resources at the excellent cognitive neuroscience site GoCognitive.net.
Practical insights from this research abound for those in learning and performance support. Many of the resulting methods, however, run counter to prevailing assumptions about learning. For example, experiments have shown that creating more difficult learning opportunities can improve the long-term retention of the information. Something as simple as quizzing a learner on information before it is introduced can improve the understanding and memory of it after.
In the same way that emotion or mood affects the brain's ability to learn, the context in which the retrieval of memory occurs has a measurable impact on later retrievals of the same information. We'll address some of these methods in future Insight posts. As always, comments are invited.
Morris Davis, PhD, is an Associate Professor at Drew University and Senior Learning, Performance, & Design Consultant to Ontuitive. Twitter: @morleydj.