Modelling variability in the social brain across the lifespan

Keeping socially active is critical for our health and well-being across the lifespan, particularly in old age. In the elderly, individuals who are less socially active are at higher risk of developing dementia, general cognitive decline, memory loss and motor function problems. New evidence also suggests that as we get older our social behavior may change. Is this due to changes in the brain? Altered social behavior can certainly occur after brain injury, significantly disrupting everyday life, but we still know very little about how which parts of the brain are important for social behavior, and whether they are disrupted with ageing.

Around 57,000 elderly people experienced some form of financial abuse in the past year, and this could be because we get worse at understanding other people's intentions as we age. Other studies show that our willingness to help other people - often referred to as prosocial behaviour - might increase with age. Despite this, there has been very little rigorous research examining these issues: As we get older, do we find it harder to understand what other people are thinking? And are we also more willing to help other people? The aim of this research is examine the biology behind these two questions.

Changes in our social abilities are likely to be linked to changes in the structure and function of the brain. We can use tools from neuroscience and mathematics to quantify these brain changes precisely and link them to how people behave when they interact with others. I will use these tools to answer three questions in samples of young (age 20-35) and older (age 65-80) healthy adults and also in patients with brain injury:

(1) Are social abilities different in the old compared to the young?
I will use two tests that can measure social abilities precisely. The first measures people's ability to understand what other people are intending to do (Social Understanding) while the second measures how much effort people are willing to invest to help others (Prosocial Motivation).

(2) How does the brain reflect these differences in social abilities?
I will use three different brain imaging techniques to examine the circuits in the brain that are linked to social understanding and prosocial motivation. Using this approach I will be able to look at how active these brain areas are during the two tests, and how strongly connected they are.

(3) Which parts of the brain are necessary for social abilities?
I will use brain stimulation tools (transcranial magnetic stimulation, TMS) to try to influence social abilities in young and older adults. TMS is a completely safe and non-invasive tool that is able to induce small but measurable changes in how different parts of the brain function. I will use this technique to examine whether it is possible to change social understanding and prosocial motivation. I will also examine changes in social behaviour in patients who have brain injury. These studies will help to show which parts of the brain are necessary for social behaviour and will provide greater insight into how social behaviour can change after brain damage.

Together, this work will provide the first biological framework to understand how key components of social abilities change across the lifespan and after brain injury. The findings from this project will lay the foundations for future applied approaches that scaffold healthy social ageing, provide greater insight into the mechanisms that underpin social behaviour in the young, and aid those with social behaviour disorders after brain injury. The ultimate aim, in the long term, would be to use the outcomes of this project to develop strategies for improving lifelong health and wellbeing, and reduce expenditure on health and social care systems.

New evidence suggests that as we get older our social abilities, such as our ability to understand other people's intentions (Social Understanding) and our willingness to help others (Prosocial Motivation) can change. Yet, we currently know little about the neurobiology of social behaviour across the lifespan. The aim of this fellowship is to use cutting edge techniques in computational modelling to provide a mechanistic framework for understanding individual differences in the social brain across the lifespan and after brain injury.

(1)Social abilities change across the lifespan, as indexed by reduced social understanding and increased prosocial motivation.
I will perform the first behavioural experiments to quantify and compare social abilities in young and older adults within a computational framework.

(2)Activity in hypothesised cortical regions underpins social understanding and prosocial motivation
I will use a combination of neuroimaging techniques (fMRI, DTI, rsfMRI) to test anatomically specific hypotheses about the regions that underpin social understanding and prosocial motivation. Using DTI and rsfMRI I will test whether age-related changes in the strength of connections between these regions accounts for age-related changes in task performance.

(3)Hypothesised cortical regions are causally involved in social understanding and prosocial motivation
To examine causal contributions of specific brain areas, I will test changes in social abilities after brain stimulation and in patients with brain injury.

This work will provide the first computational and biological framework to understand individual differences in the social brain across the lifespan and how changes in the brain can lead to changes in social behaviour. This will provide researchers, clinicians and industry with an evidence-based framework from which to design strategies to scaffold healthy social ageing and to aid those with recovery after brain injury.

Impact summary

(1) Who will benefit from this research?

By 2060, age-related spending, such as spending on pensions and healthcare, is projected to rise to 26.3% of GDP, equivalent to a rise of around £79bn in the UK, and a rise of up to 29.8% of GDP in the EU (International Longevity Centre, UK). This research has the potential to contribute to the nation's health and wealth by informing policy and practice in ways that will maintain and improve social abilities across the lifespan and after brain injury, with an aim to provide an evidence-base to reduce the amount of age-related spending. Key beneficiaries include professionals working with young and old people, such as doctors, nurses, clinical psychologists, neurologists, occupational therapists, and professionals working in social care; young and old people; patients with brain injury; charities working with the elderly, including Age UK, Age Concern and the Center for Ageing Policy; Charities working with those with brain injury such as Headway and Stroke Association; policy makers in the Department of Health and Department of Work and Pensions; and public and private sector industries.

(2) How will they benefit from this research?

Policy makers in the Department of Health and Work and Pensions/public and private sector industries: In the long term the proposed research has scope to have a broad societal and economic impact, both in the UK and internationally. This research can help to inform knowledge about healthy social ageing and how key social abilities change in older age. In public and private sector industries, these findings may help, in the long term, to inform individuals working in human resources departments in making decisions about recruitment and support of staff.

Ageing and brain injury charities: The research will be of benefit to these groups in the short to medium term. I plan to communicate my research findings widely within these groups to raise awareness of the precise nature of the biology of social abilities, and why there are individual differences. This is vital in a field in which we have a limited evidence-based understanding of changes in social abilities across the lifespan or after brain injury. In the longer term, it is hoped that the research will contribute to the evidence base on which new and improved initiatives can be developed, in partnership with these professionals. Engagement with charities will help their case for supporting individuals to keep socially active and to help elderly individuals and those with brain injury when making social decisions.

Practitioners and social workers: The research is likely to be of benefit to practitioners in the medium term. The findings will provide greater detail of how the brain changes as we age and after brain injury and the impact this may have on people's social abilities. I aim to utilise channels made possible by professional and consortium groups such as Age UK, Stroke Association and OXDARE, so that the research findings may inform both preventative and intervention strategies implemented by social workers and those working in the care of the elderly and neuropsychological patients.

Young and old people, patients with brain injury, and their carers: In the short term, I aim to communicate with a broad demographic of society including young and old people, through the pathways identified in the pathways to impact statement. In the longer term, it is hoped that these groups will benefit from improved understanding. All these groups may find it challenging to understand how social abilities change with age or after brain injury, and the potential consequences of these changes, such as being more vulnerable to financial fraud. A fuller understanding of why and how social abilities may change can make care easier to provide and promote positive social interactions between these groups.