Why does being active in large groups at festivals, jubilees, and other public events generate such a buzz? According to the social brain theory, the human brain has largely evolved to support social interactions. It has shown that belonging to a group can lead to improved happiness and increased satisfaction with life.
Despite this, many individuals are lonely or socially isolated. And since the human brain really did develop for social interaction, we should expect it to be significant.
Our recent research, published in Neurology, demonstrates that social isolation is linked to changes in brain structure and cognition the mental process of learning it even carries a higher risk of dementia in older adults.
There''s already a lot of evidence to support the social brain hypothesis. One study mapped the brain regions associated with social interaction in around 7,000 people.
It found that brain regions constantly involved in diverse social interactions are well-connected to networks that support cognition, such as the default mode network (which is active when we are not focused on the outside world), the salience network (which helps us select what we pay attention to), the subcortical network (involved in memory, emotion, and motivation) and the central executive network (which allows us to regulate our emotions).
We wanted to look at how social isolation impacts grey matter brain regions in the outer layer of the brain, consisting of neurons. We, therefore, collected data from nearly 500,000 people in the UK Biobank, with a median age of 57.
If people were living alone, had less social contact monthly and participated in social activities less than weekly, they would be classified as socially isolated.
Interestingly, we included neuroimaging (MRI) data from around 32,000 people. This showed that socially isolated individuals had poorer cognition, including in memory and reaction time, and decreased the amount of grey matter in many tissues of the brain.
These areas included the temporal area (which processes sounds and assists encode memory), the frontal lobe (which is involved in attention, planning, and cognitive tasks) and the hippocampus, which is a key area involved in learning and memory, which is typically disrupted early in Alzheimer''s disease.
A connection between the lower grey matter volumes and specific genetic components involved in Alzheimer''s disease has been also discovered.
Twelve years later, there were follow-ups with participants. This showed that individuals who were socially isolated, but not lonely, had a 26 percent increase in dementia.
In future discussions, social isolation should be studied more closely to better understand the key mechanisms behind its profound effects on our brains. However, it is clear that, if you are isolated, you may be suffering from chronic stress. This has a significant impact on your brain, as well as your physical health.
If we don''t use certain brain areas, we lose some of their function. A study with taxi drivers showed that the greater their routes and addresses, the greater the volume of the hippocampus, therefore, it is possible that our use of language and other cognitive functions, such as attention and memory, may be reduced.
This may adversely impact our ability to deal with several complex cognitive tasks, but memory and attention are crucial to developing complex cognitive thinking in general.
We know that a large set of thinking abilities throughout life, referred to as "cognitive reserve," can be built up by maintaining your brain active. A good way to do this is by learning new things, such as another language or a musical instrument.
Cognitive reserve has been shown to improve the course and severity of ageing. For example, it can help combat a variety of illness or mental health difficulties, including dementia, schizophrenia, and depression, particularly following a traumatic brain injury.
A variety of lifestyle concepts can increase your cognition and wellbeing, including a healthy diet and exercise. For Alzheimer''s disease, there are a few pharmacological therapies, but the efficacy of these therapies must be enhanced, and side effects must be reduced.
Exogenous ketones are a valuable alternative energy source to glucose, which can be ingested via nutritional supplements.
Especially in early age, tackling social isolation might be beneficial, according to our study. Health authorities should do more to check on who is isolated and organize social activities to assist them.
When people are not in a position to interact in person, technology may be a substitute. However, this may be more applicable to younger people who are familiar with using technology to communicate. However, training may be beneficial in reducing social isolation in older adults.
Social interaction is enormously important. One study discovered that the width of our social group is actually linked to the volume of the orbitofrontal cortex (involved in social cognition and emotion).
For example, how many friends do we need, use "Dunbar" to describe the size of social groups, finding that we are not capable to maintain more than 150 relationships and only typically manage five close relationships.
Despite a number of claims, there are still hints about a lack of evidence about Dunbar''s number, and further research is required.
Humans are social animals, and we gain access to others regardless of the age we are. But, as we become more aware, it is also essential to our health.
Barbara Jacquelyn Sahakian, a research associate with cognitive neuroscience at the University of Cambridge, and Chun Shen, a research fellow at Fudan University, and Jianfeng Feng, a researcher in science and technology at Fudan University.
This article has been published from The Conversation under a Creative Commons license.