PUTTING THEIR HEADS TOGETHER
Can a healthy long-term relationship or marriage stave off dementia later in life? Researchers at the Macquarie University-based Australian Hearing Hub are exploring the role of hearing and memory collaboration in cognitive and brain health.
Dementia is proving to be one of the greatest global health and social challenges of our time. With no disease-modifying treatment currently available, interventions targeting the modifiable risk factors of dementia currently are our ‘best medicine’.
Recent research has shown that of all the modifiable risk factors for dementia, mid-life hearing loss is one of the most significant.
“We know that untreated hearing loss is associated with an increased risk of developing dementia,” said Professor Amanda Barnier from the Department of Cognitive Science at Macquarie University, and part of an interdisciplinary group of hearing, memory and ageing practitioners and researchers at the Australian Hearing Hub.
“Hearing loss can lead to social disengagement, isolation and depression – themselves all risk factors for developing dementia. So together with collaborators from Cochlear Limited, Australian Hearing and its research arm National Acoustics Laboratory, and Macquarie University’s Centre for the Implementation of Hearing Research and Centre for Emotional Health, we are studying the relationship between hearing loss, successful communication, emotional health and cognitive decline.”
In one recently completed ARC-funded study, Professor Barnier, Dr Celia Harris (also from Cognitive Science) and Professor Greg Savage (from the Department of Psychology) worked with couples who have been married for, on average, 50 years. The researchers investigated whether shared remembering in intimate groups like this can compensate for, and possibly protect, older adults from the effects of cognitive decline and very early dementia.
This research was conducted in partnership with the Australian Imaging, Biomarkers and Lifestyle (AIBL) Study of Ageing, established in 2006 to discover the factors that predict subsequent development of Alzheimer’s disease. Professor Savage and Professor Ralph Martins (from Macquarie University’s Department of Biomedical Sciences) are two of the leaders of this study, the largest of its kind in Australia.
Working with AIBL, Professor Barnier, Dr Harris and Professor Savage interviewed long-married couples about their memories of daily life – such as the names of friends, holidays they had taken and events of their wedding day – first alone, then together.
“We ask them to engage in memory collaboration – to remember different kinds of information together,” explained Dr Harris. “We compare their joint remembering with how they remember alone, and map the ways in which they support one another’s cognition. We hope to identify the communication or conversational strategies that couples use to successfully remember together.”
The researchers are testing ‘distributed cognition’ – an idea from philosophy that says we use and rely on people and things outside our head to support and scaffold everyday mental processes.
“As children, our parents teach us what is worth remembering and help us when we forget,” said Dr Harris. “As adults, we jog our memories with objects in our environment such as markers in the landscape, photo albums, travel souvenirs and iPhones. We also form ‘transactive memory systems’ with partners, family and friends to share the load of encoding, storing and retrieving important memories and information.”
An important finding is that couples remember much more on average when interviewed together than when interviewed alone, especially for more personally relevant memory tasks.
Additionally, the researchers are working to identify communication strategies that predict successful memory collaboration.
“Couples who agree on a strategy for remembering together, who offer memory cues to one another and who acknowledge and repeat their partner’s contributions typically remember better together,” explained Dr Harris. “Also, couples who are sensitive to one another’s memory abilities are more likely to use memory strategies that increase their collaborative success.”
The possibility that older adults may benefit cognitively from collaborating with their partner might help to explain fascinating new findings from an analysis of over 812,000 people involved in 15 studies of dementia from around the world: married people were found to have a 42 per cent lower risk of developing dementia than lifelong singletons and a 20 per cent lower risk than bereaved people.
In studying long-married AIBL couples, the researchers are also finding that not all couples collaborate successfully. Couples who disagree on a memory strategy or who correct or discount the contributions of their partners appear less successful when remembering together. Also, couples where one partner dominates the conversation show less evidence of the collaborative strategies that predict memory success.
The researchers noticed another important pattern – although they weren’t looking for it to begin with.
“Couples who report hearing difficulties in everyday life and who seem to have trouble hearing one another during our interviews appear to gain much less benefit from remembering together,” said Professor Barnier.
“Difficulty hearing your family and friends is not just socially isolating but is cognitively isolating as well. If you are cognitively isolated, you may miss out on the benefits of distributed cognition.”
The research team is about to embark on a large, cross-sectional, observational program to tests possible links between hearing loss and cognitive impairment. This research will evaluate whether hearing treatment can improve communication and collaboration, can combat social isolation and depression, and have flow-on benefits for cognitive performance and health.
BE AN EARLY BIRD: GET ON TOP OF HEARING LOSS EARLY
Research shows that people with mild symptoms of hearing loss may be twice as likely to develop dementia than those with healthy hearing. People with severe hearing loss may be five times more likely to develop dementia.
Intervening early in hearing loss can help people to stay socially and cognitively connected. Hearing interventions may also reduce the risk of developing dementia later in life. Unfortunately, people wait 7-10 years on average following a diagnosis of hearing loss before seeking treatment.
There ARE strategies to help: Start by making an appointment with your GP who will refer you to an audiologist for an assessment. The audiologist can determine the type and magnitude of the hearing loss and provide solutions for managing it. Some hearing services are subsidised by the Australian Government (for more information, see www.hearingservices.gov.au) or some types of private health insurance.
THE COST OF DEMENTIA TO AUSTRALIA
Around 400,000 Australians and 47 million people worldwide are living with dementia, with about 300,000 family members, friends and others are involved in their care. By 2056, an estimated 1.1 million Australians (131 million worldwide) will be living with dementia at a cost of nearly $37 billion to our nation.
ABOUT THE AUSTRALIAN HEARING HUB
Macquarie University and the Australian Hearing Hub are hosts to leading hearing health providers, researchers and innovators from Australian Hearing, Cochlear Limited and the National Acoustic Laboratories. It is home to the ARC Centre of Excellence in Cognition and its Disorders, the Macquarie University Centre for Implementation of Hearing Research, the Macquarie University Centre of Emotional Health, and the Departments of Cognitive Science, Linguistics and Psychology.