By tying together more than a century of memory research at Cambridge, the Memory Lab gives us tangible ways to improve, preserve and understand our memory.
When anxious thoughts flood our minds, they compete for space in our working memory and impair our ability to recall long-term memories. If we can find ways to reduce stress and anxiety, our memory can often bounce back.
Jon Simons
What is a memory?
Is it a distinct pattern of brain activity, a blueprint for future behaviour, or a skill that we can improve with a little training? Probably all these things and more, argues Jon Simons, Professor of Cognitive Neuroscience in the Department of Psychology and Head of the School of the Biological Sciences.
Jon's Memory Lab studies all aspects of memory. They invite volunteers to complete memory tasks online, in the laboratory, or sometimes while lying in an MRI machine while the team scans their brains.
If memory serves
The biochemical changes that represent memories range across the brain's real estate. A long list of factors determine which brain areas light up during the experience: whether a memory is being encoded or reconstructed, whether it's an old or a new pattern, and what kind of information it deals with.
"We know that the hippocampus is crucial for forming new memories, but it's not necessarily the permanent storage site," Jon says. "For long-term storage, we also recruit cortical areas - the frontal lobes, temporal lobes, parietal lobes and more."
To plot a route through tangled terrain, researchers divide memory into different types. Short-term memory lasts a minute at most and has a limited capacity - around 7 items give-or-take, according to Harvard's George Miller in the 1950s. Think of repeating numbers to yourself while jotting down someone's phone number. If we don't record those numbers fast enough, they'll fade quickly.
But even short-term memory isn't unitary. Alan Baddeley (Churchill 1959), former director of Cambridge's Medical Research Council (MRC) Applied Psychology Unit (now called the MRC Cognition and Brain Sciences Unit), coined a new way of understanding how short-term memories are stored and manipulated. His 'working memory' model proposes that separate brain systems deal with different kinds of inputs. One part rehearses and replays sounds, for instance, while another holds visual information like a 'mental canvas'.
This is different yet again from our long-term memories. These deeper experiences can stay with us for a lifetime. Recalling them can be thought of as a kind of 'mental time-travel', allowing us to subjectively relive past events complete with the sights, smells and sounds of cherished scenes.
Researchers now believe that we reconstruct our memories each time we experience them. From scant traces, we extrapolate the narrative of what happened. In this way, memory is a creative act, not a simple recap. One classic Cambridge study revealed how our memories are morphed by bias, beliefs, feelings and expectations.
Cambridge's long memory
Enter the elegant study of Sir Frederic Bartlett, Cambridge's first Psychology professor.
Bartlett's book 'Remembering' (1932) made use of a now famous story: the war of the ghosts.
In this Native American folk tale, a man meets warriors paddling their canoes downriver, who invite him to join a war party. He later realises the men are ghosts, waging war on the living.
Bartlett taught his Edwardian undergraduates this tale, then asked them to retell it in their own words. Over several retellings, his students altered key elements of the story so that it sounded more like the world they knew. 'Canoes' became 'boats', while mentions of 'spirits' were dropped altogether.
Bartlett's study showed the effects of culture on recall, and how the changes we make to our memories aren't random. Even if we're not conscious of doing so, we prefer to change story elements so that they align with our expectations, biases and cultural norms.
This feature of memory has massive implications for how we remember the past. Eye-witness testimony will be prey to the same biases. Unintentional errors, made in favour of what is familiar to us, are very difficult to avoid.
Another titan of memory research was an undergraduate while Bartlett was teaching. During World War II, Brenda Milner (Newnham 1936) helped the Psychology department repurpose itself for the war effort. After this, Milner moved to Canada to analyse patient Henry Molaison (formerly known as H M). Molaison would become one of the most famous patients in all of psychology.
Molaison had profound amnesia. This was due to experimental surgery, where doctors removed his hippocampus to try and improve his epilepsy. Milner meticulously documented how Molaison's memory functioned after surgery. She showed how he was unable to form new memories or remember events from the years leading up to his surgery, but that his memories from earlier in life remained intact. This work transformed our understanding of the hippocampus' role in memory.
Psychologists like Milner and Bartlett showed us the primacy of the hippocampus and highlighted the creative nature of memory. Modern Cambridge researchers can take our investigations even further.
Peak performance
With all we now know about memory, can we understand what makes for better performance?
Together with Professor Simon Baron-Cohen and his team at the Autism Research Centre, Jon is currently studying thousands of the UK's best memorisers to find the keys to their prowess. Volunteers completed a battery of memory tests online - the best performers then came for brain scans and further testing in the lab.
Their early results suggest some interesting traits, as well as the strategies people use to enhance their abilities.
"There's a psychological trait called 'systemising'," says Jon. "It's found in people who have a drive to analyse and construct rule-based ways of thinking. Those kinds of people seem to be more likely to have exceptional memories."
Simon Baron-Cohen was the first to define this trait. He did so in relation to people on the autism spectrum, for whom 'systemising' is set very high.
So if you happen to think like a 'systemiser', you may have a better memory. If you don't, there are also concrete strategies to boost your memory capacities.
"Mnemonics are an evidence-based technique that can improve our memories," Jon explains. "They often involve thinking spatially. Start by visualising somewhere you know well, then mentally 'place' important information in that map. You can then 'travel through' that map when recalling."
Think Sherlock's 'mind palace' from the BBC adaptation of Arthur Conan Doyle's books. Jon points out that pre-BBC, this strategy was familiar to ancient Greek and Roman orators. They called it the method of loci, using it as a way to remember extremely long speeches. It can also be helpful for everyday tasks, like remembering a shopping list.
Jon's tip for this method is to make the memory triggers striking. Associate the eggs on your shopping list with a fire-breathing dragon guarding its young, for example, and the sensory impression might be distinct enough to stand out from the background noise.
"The more bizarre the better! Our memories have a big job in trying to differentiate one memory from another. We can help it out by making key information more distinctive. This helps our brains to distinguish memories from one another, and stop irrelevant ones from overlapping or interfering."
Indeed, one of the functions of the hippocampus is to perform pattern separation - trying to make our memories distinct. If memories are too similar, we find it harder to recall specific experiences.
This might go some way to explaining the 'brain fog' many experienced during COVID-19 lockdowns. With days inside tending to repeat familiar routines, we had less distinct and varied experiences. Our brains were less able to create rich, meaningful memories. Looking back on 2020 and 2021, people find it hard to separate what happened when.
There's a lesson for non-lockdown living here too. If we want a rich life that feels like it lasts longer and is full of accessible, interesting memories, we should prioritise variety in our experience.
To further improve memory function, we should strive to decrease stress, fear and anxiety (where possible). These emotional states increase our cognitive load and reduce our memory abilities.
"When anxious thoughts flood our minds, they compete for space in our working memory and impair our ability to recall long-term memories. They pull attention and resources away from the things we'd like to focus on. If we can find ways to reduce stress and anxiety, our memory can often bounce back."
While this might be easier said than done, science has concrete recommendations for reducing stress and anxiety. Done consistently, a healthy diet, regular exercise and a good sleep schedule, as well as techniques like mindfulness practice, can have transformative effects.
Researchers like Jon are deepening our understanding of what memories are. The Memory Lab follows an illustrious line of Cambridge psychologists who identified key pieces of memory's endless puzzle. Wherever the next steps lead, they will affirm a wonder of nature: the intricate patterns our mind weaves to make sense of the world outside.
For a handy guide to building mental resilience, check out Brain Boost by Dr Barbara Sahakian and Dr Christelle Langley. To focus on fighting anxiety with scientific techniques, try Dr Olivia Remes.
