How to Better Remember the Past

By Benjamin J. Griffiths, Ph.D.; edits by Patricia Lockwood, Ph.D., and Jo Cutler, Ph.D.

We’ve all been there. You head out to the supermarket and, as soon as you arrive, you realise you’ve completely forgotten what you came to buy. Why do we forget such simple things? Scientists suggest it is because of the “context-dependent” nature of our memories. In this post, we ask why our memories can be so tricky to recall and explore techniques that may help boost our ability to remember key information.

Many of our long-term memories are thought to be “context-dependent”; this means that our ability to recall the memory depends on how similar the learning and recalling environments (or “contexts”) are. When we memorise a shopping list at home, and then try and recall the shopping list in the supermarket, we have changed our environment and this impairs our ability to recall the list. This can also help to explain another important phenomenon — why when we return home, we suddenly remember everything we forgot to pick up at the store. We are back in the environment in which we learned the list helps us remember everything we forgot to pick up.

A deep dive into “context-dependent” memory

What evidence is there to suggest that long-term memories are “context-dependent”? A classic example is the diver study by Godden and Baddeley in the 1970s. Godden and Baddeley took a group of experienced divers up to a loch in the highlands of Scotland and subjected them to a bizarre memory test. The divers had to learn a list of words (much like a shopping list) on land or underwater, and then later recall that list while either on land or underwater. When divers were in the same environment during both learning and testing (e.g., they both learned and remembered the list underwater), they were much better at remembering the words. Matching the context between learning and recall helped their memory.

So, what’s going on here? Why does context help (or hinder) our memories? One influential theory suggests that context can act as a cue to help recall target memories. This happens because when we create a memory, we automatically glue together every detail of the event into a singular memory trace — this includes not only the target information (e.g., the items on the shopping list) but also surrounding contextual details (e.g., the sounds and smells of the kitchen). When we return to the same environment, these contextual details act as a mental spotlight to help us search for that list of ingredients we need to remember. In a different environment, however, we cannot make use of this spotlight, leading to a more challenging search of our memories.

Remembering events where they happened can boost our recall

Source: Lisa Fotios/Pexels

And what is the brain up to during these key moments of memory? While creating and recalling memories depend on many brain regions, the context-dependent nature of our memories seems to depend principally upon the hippocampus. The hippocampus is thought to glue target information to the surrounding contextual information during memory formation and then use contextual cues (such as the current environment) to bring these memories back to life. In line with these ideas, research conducted by myself and others has shown that the level of hippocampal engagement during memory formation predicts how greatly we benefit from the overlap of context between learning and recall. Indeed, when the hippocampus is damaged, individuals may completely lose the ability to form long-lasting memories, highlighting just how important the hippocampus is to memory.

Putting the theory into practice

So, matching the context we learn in to the context we remember in will help our memory. But how can we make the most of this knowledge in daily life? Well, if we know where we might need to remember something, we can try our best to learn in that same environment. For example, if there is an important work presentation coming up, we can try and practice in the same room where the presentation will occur in. The contextual overlap between the practice and the main event may give you that extra little boost needed to deliver a spectacular presentation.

But what happens when we can’t match the contexts between learning and memory? What happens when we want to recall a shopping list, where the learning environment is inherently different than the recall environment? Well, we could instead use a “mental” context; a context that doesn’t exist in the physical world, but instead sits within our mind. A powerful technique in this vein is the “Method of Loci”. The Method of Loci involves imagining a familiar journey you take (e.g., the commute to work) and mentally tying or linking items from your shopping list to landmarks on that journey. For example, you might tie “bread” to the park you pass when you leave your house, and “milk” to the stadium you pass further down the road. Then, when you need to remember your shopping list, you recall the pattern of your commute and this in turn will help you recall the food products you mentally placed along the way. While a seemingly peculiar method to remember your shopping list, time and time again, research has shown that the Method of Loci drastically improves our memory.

Wrapping Up

It will come as a surprise to no one to learn that our memories are imperfect; we are certainly going to forget key bits of information at the times we need it most. However, armed with the knowledge of context, we can do a little bit to hack memory to work in our favour. If we know where or when we might need a particular memory, we can try our best to learn that information in the same environment, and if that’s not possible, we can create our own mental contexts to help instead. It may take a little practice, but it will certainly pay off.