How does our memory work? What can we do to keep it in good shape? Can we actually prevent a decline in memory? These were just some of the questions addressed in a public symposium on the science of memory in Trinity College Dublin’s week-long focus on memory this month.
Lecturers in neuroscience, neuropharmacology, neuropsychiatry and physiology spoke about what we know about how the brain works. Importantly, they also spoke about what we still don’t know about what is arguably the most important organ in the human body.
In his introduction to how memory works, Shane O’Mara, professor of experimental brain research, tricked the audience by showing them well known images (such as a €20 note and the Apple logo), some of which were in reverse form.
Most people couldn’t identify the correct images even though they see them every day. “This is just to show that our memories are fragile and attention saturation and learned irrelevance are factors. A feeling of familiarity is not the same as actually memorising something,” said O’Mara.
Anyone studying for exams should also take note that “exposure to information doesn’t ensure learning”, he said. Learning occurs in three stages – encoding, consolidation and retrieval.
“Re-reading text and practising a skill or new knowledge are the preferred study practices, yet retrieval has a greater effect on learning than either encoding or consolidation,” he said. In other words, answering questions on what you have studied is the most effective learning strategy. And, sleep deprivation causes amnesia.
“We all know this intuitively but studies show it too, so pulling an all-night study session is not as good as doing shorter bouts of study with breaks.”
Physical exercise is also another very significant factor in keeping your memory in good shape. “Education, mental stimulation, diet and social engagement are all important factors but it has now been found that physical activity has a profound effect on memory,” he said.
Dr Áine Kelly, head of physiology in the school of medicine, spoke about the biological basis of memory. “Neurogenesis – which is the birth and development of new neurons [nerve cells] – is the basis of memory in the long term. We know now that new nerve cells develop in humans but 30 years ago, to say this was neuro-scientific heresy.
“Studies have shown that about 700 new neurons are generated every day in the hippocampus area of the brain which means about 1.75 per cent of the hippocampus [the area of the brain responsible for memory] is renewed each day.”
Further studies have shown how physical exercise creates an anti-inflammatory response which protects the body against chronic diseases associated with long-term low-grade inflammation.
“What happens is that secretions from muscles and glands during exercise help us to build cognitive reserve and resilience [ie the ability to learn and remember things] by promoting neurogenesis in the brain,” said Kelly.
And, yes, studies have also shown a physiological response to exercise corresponds to improved performance at a learning task.
Kelly recommends people aim to do 150 minutes of aerobic exercise per week.
Often the mere mention of the word memory strikes fear into people about its potential loss, and Dr Sabina Brennan, research assistant professor at the Trinity College Institute of Neuroscience, spoke about the stigma of dementia and what people can do to promote brain health.
A series of short animation films made by Brennan clarify misconceptions about dementia and encourage everyone to interact with people with dementia. “There is a false belief that nothing can be done to reduce the risk of dementia and that memory is a unitary function,” she said.
Neuroscientists now know that different parts of the brain are responsible for different types of memory such as memory of facts, events, emotions and how to physically do things.
“It’s important to remember that someone with dementia will still have emotional memory. Even if they forget your name, they still are happy to see you and will remember it on some level,” said Brennan.
The animation films, which include one on what you can do to keep your brain healthy, can be watched on hellobrain.eu
Meanwhile, Brennan is about to embark on two new films and a social media awareness raising campaign on the impact of caring for someone with dementia.
Finally, the biggest question of all still eludes researchers, which is how can dementia such as Alzheimer’s disease be cured? Michael Rowan, professor of neuro-pharmacy, spoke about how research into anti-bodies carried in the blood can be used to diagnose dementia, but no cure is currently in sight.
“There are ongoing clinical trials to treat mild to moderate Alzheimer’s disease but it’s at a very preliminary stage,” he said.
Observing the changes in brain structure and function with magnetic resonance imaging (MRI) scans is another area of research into dementia. “It is thought that any potential treatment will be most effective in early-stage disease so we are using MRI to investigate changes in the brain from normal cognition to mild cognitive impairment [mild memory difficulties associated with dementia and some other conditions] to dementia,” explained Dr Arun Bokde, while speaking about the functional anatomy of memory.
The very latest research into dementia stresses that while we may see an increase of cases in the next 15 years or so, overall numbers might be on the decline.
With more emphasis on keeping physically fit, mentally and socially engaged, research is pointing to how we can preserve at least some parts of our memory as we age.
The power of poetry
As part of Trinity Week focus on memory, The Mercer's Institute for Successful Ageing at St James's Hospital in Dublin celebrated the opening of its new building with a poetry reading by poet Michael Longley.
Reading poems on the theme of memory by Donald Hall, Ruth Stone, WB Yeats, Louis MacNeice and himself, Longley brought an appreciative silence to a crowded lecture theatre in Trinity College Dublin.
"I think I can describe myself as successfully aged," said the septuagenarian, sprinkling comments about his 50-year marriage to literary critic, Edna Longley, his much-loved seven grandchildren and the recent death of his twin brother between the verses.
Longley received the 2015 Griffin International Poetry Prize for his book, The Stairwell (2014). “And, my next book will be titled Angel Hill,” he said quietly as he thanked the audience for their attention.