Socially Isolated People Have Differently Wired Brains and Poorer Cognition

Summary: Social isolation is linked to alterations in brain structure and cognitive deficits. Additionally, social isolation can increase the risk of developing dementia as a person ages.

Source: The Conversation

Why do we get a buzz from being in large groups at festivals, jubilees and other public events? According to the social brain hypothesis, it’s because the human brain specifically evolved to support social interactions. Studies have shown that belonging to a group can lead to improved wellbeing and increased satisfaction with life.

Unfortunately though, many people are lonely or socially isolated. And if the human brain really did evolve for social interaction, we should expect this to affect it significantly. Our recent study, published in Neurology, shows that social isolation is linked to changes in brain structure and cognition – the mental process of acquiring knowledge – it even carries an increased risk of dementia in older adults.

There’s already a lot of evidence in support of the social brain hypothesis. One study mapped the brain regions associated with social interaction in approximately 7,000 people.

It showed that brain regions consistently involved in diverse social interactions are strongly linked to networks that support cognition, including the default mode network (which is active when we are not focusing 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 enables us to regulate our emotions).

We wanted to look more closely at how social isolation affects grey matter – brain regions in the outer layer of the brain, consisting of neurons. We, therefore, investigated data from nearly 500,000 people from the UK Biobank, with a mean age of 57. People were classified as socially isolated if they were living alone, had social contact less than monthly and participated in social activities less than weekly.

Our study also included neuroimaging (MRI) data from approximately 32,000 people. This showed that socially isolated people had poorer cognition, including in memory and reaction time, and lower volume of grey matter in many parts of the brain.

These areas included the temporal region (which processes sounds and helps encode memory), the frontal lobe (which is involved in attention, planning and complex cognitive tasks) and the hippocampus – a key area involved in learning and memory, which is typically disrupted early in Alzheimer’s disease.

We also found a link between the lower grey matter volumes and specific genetic processes that are involved in Alzheimer’s disease.

There were follow-ups with participants 12 years later. This showed that those who were socially isolated, but not lonely, had a 26% increased risk of dementia.

Underlying processes

Social isolation needs to be examined in more detail in future studies to determine the exact mechanisms behind its profound effects on our brains. But it is clear that, if you are isolated, you may be suffering from chronic stress. This in turn has a major impact on your brain, and also on your physical health.

Another factor may be that if we don’t use certain brain areas, we lose some of their function. A study with taxi drivers showed that the more they memorised routes and addresses, the more the volume of the hippocampus increased. It is possible that if we don’t regularly engage in social discussion, for example, our use of language and other cognitive processes, such as attention and memory, will diminish.

This may affect our ability to do many complex cognitive tasks – memory and attention are crucial to complex cognitive thinking in general.

Tackling loneliness

We know that a strong set of thinking abilities throughout life, called “cognitive reserve”, can be built up through keeping 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 ameliorate the course and severity of aging. For example, it can protect against a number of illnesses or mental health disorders, including forms of dementia, schizophrenia and depression, especially following traumatic brain injury.

This shows a man sitting on his own
People who are isolated from others do worse on cognitive tests. Image is in the public domain

There are also lifestyle elements that can improve your cognition and wellbeing, which include a healthy diet and exercise. For Alzheimer’s disease, there are a few pharmacological treatments, but the efficacy of these need to be improved and side effects need to be reduced.

There is hope that in the future there will be better treatments for aging and dementia. One avenue of inquiry in this regard is exogenous ketones – an alternative energy source to glucose – which can be ingested via nutritional supplements.

But as our study shows, tackling social isolation could also help, particularly in old age. Health authorities should do more to check on who is isolated and arrange social activities to help them.

When people are not in a position to interact in person, technology may provide a substitute. However, this may be more applicable to younger generations who are familiar with using technology to communicate. But with training, it may also be effective in reducing social isolation in older adults.

Social interaction is hugely important. One study found that the size of our social group is actually associated with the volume of the orbitofrontal cortex (involved in social cognition and emotion).

But how many friends do we need? Researchers often refer to “Dunbar’s number” to describe the size of social groups, finding that we are not able to maintain more than 150 relationships and only typically manage five close relationships.

However, there are some reports which suggest a lack of empirical evidence surrounding Dunbar’s number and further research into the optimal size of social groups is required.

It is hard to argue with the fact that humans are social animals and gain enjoyment from connecting with others, whatever age we are. But, as we are increasingly uncovering, it also crucial for the health of our cognition.

About this social isolation research news

Authors: Barbara Jacquelyn Sahakian, Christelle Langley, Chun Shen, and Jianfeng Feng
Source: The Conversation
Contact: Barbara Jacquelyn Sahakian, Christelle Langley, Chun Shen, and Jianfeng Feng – The Conversation
Image: The image is in the public domain

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  1. If social isolation is harmful, can breaking out of it reverse any damage that may have already been done? I’m talking about doing things like attending and participating in 12 Step Recovery groups, Meetup Groups and so forth.

  2. I just crossed this article while scrolling down on my daily recommendation news. I can say this article is nor scientific nor have good quality. They oversize things and have no real conclusion. Neuroscience you should know that dementia, alzemier and other mental diseases r more related to genetics and trauma throughout life than social interactions on elderly time.
    Pls, correct your page cause this may cause problems for ppl already struggling in social life.

  3. This is nonsense, just another way of pinning introverts as bad people or having mental issues. I hate being in large crowds and I for the most part avoid people now because I’ve come to learn that the real monsters are humans.

  4. This article is an outrageous bastardization of this research. And the research itself is not nearly statistically significant enough to justify such a strong conclusion. It’s not even strong enough to suggest correlation, nonetheless causation.
    These are wild claims being published by an alleged science site? You should be ashamed of yourself. This is click baiting at best.
    Are you going to write an article about how excessive socialization actually blinds you from the faults of the people immediately in front of you while magnifying the faults of those you don’t know. That’s probably how you came to these outrageous claims in the first place.

  5. I don’t think this is a good article. I am not scientist but I think is irresponsible to put an article with such a general conclusion. What about monks? Or yogis? Or people that by choice decide to meditate for months or years? What about scientist? Researchers? Many of those have very little social interaction yet their brain works amazingly fine. Now I feel anxious and depressed by reading this. I am then a loser, lonely middle age woman going through menopause and waiting for dementia to get me.

  6. Wow. “Why do we get a buzz from being in large groups…” Stop reading right there. This is not a scholarly article or anything close. Not everyone feels this way in large groups. While the majority of people are more extroverted, there is a sizable percentage of people who are introverted. This article is badly extroverted biased and yet another attempt to make us introverts feel like something is wrong with us. My guess? Stress is one of the biggest factors in every health issue, so stress from isolation for extroverts or stress from exhaustion at always having to fit in to extroverted dominated systems leads to to dementia.

    Join the introvert revolution! Be happy by yourself or in small groups and find a way to make it work for you.

  7. What about mass incarceration for long period s of time? I spent nearly 10 years with less then 1000 in entire facility.. 300 in a unit.. I’ve been out over 5 years but now after pandemic it’s like having to remerge into public or society again but it’s even harder then before. Especially now that I have a 2yr old born right at start of pandemic. I know I’m stressed but I’m more numb then anything I think.But society n doctors don’t see it as a issue or real problem. @m I just instatutionalized? I was thriving until son and pandemic…n I’m struggling so bad but no one understands what I’m going through..

    1. I do.. I understand… if that helps u any. The isolation that Covid caused & once the ‘self isolating’ restrictions were lifted WOULD be just like being released from prison absolutely! I would imagine the restrictions laid upon us would have set u & many others back to the same feelings u got when u started ur bit… the anxiety, the fear, depression, its ALL very real!
      I know this also… u managed to survive a 10yr bit, brought a new life into this world..which is 1 of the best part about being alive.. u got this.. when u start doubting urself take a moment to gaze into the face of ur child… THATS what makes life worth living! I wish all the best to u & ur family.. God bless!

  8. No. That’s absolutely NOT what this study means. I know it’s written in a way that seems to suggest this particular definition of social isolation *causes* problems with memory, cognitive abilities, and even dementia. But – as other commentors noted – that’s not at all what this study was actually studying, nor is there any clear evidence of a *cause and effect* relationship. This study focused on the volume of grey matter in the brain in persons who fit a certain definition of “isolated” – and even then, the researchers are relying on participants who have self-reported to fit this definition. There’s no control group, and I don’t believe it’s made clear how the volume of one’s grey matter directly or indirectly affects specific cognitive processes. Like when they say memory – Long term? Short term? What about one’s working memory? How did they test this? Was it the same test administered to each participant in controlled conditions?

    We don’t know. It doesn’t say. I’m not saying any of this to discredit anyone’s research or to trivialize their findings, and I really don’t believe the writer(s) have any intent to mislead people or engage in sensationalism. BUT after discussing the study, they start throwing in all these other things that have been found to be *associated* with loneliness or social isolation and proceed to write about it like it’s all just one big clear cut case of *cause and effect*… Which they then say isn’t the case because Dunbar’s number isn’t conclusive, and activities like learning new stuff can totally reverse or slow or stop any number of different aspects of cognitive decline. But by the time you’re reading that stuff, you’re way too preoccupied with your impending case of DOOMED BRAIN to digest this fully.

    The bottom line is there are benefits to having healthy relationships. And unhealthy or inadequate relationships can be a major cause of stress for human beings. Having a healthy relationship with yourself is really beneficial, too. If you struggle with self-acceptance, self-worth, or otherwise have some unhealthy features in your relationship with yourself, it’s probably not helping your stress levels or overall health. And that can make life feel harder and harder over time; however, you can do a lot to change, accommodate, learn to accept or forgive or learn from or create more realistic goals for or set healthier boundaries with yourself as these things dictate, and you can improve your relationship with your self and that’s great for you, too.

    Increasingly, articles meant to spread awareness and help destigmatize mental health issues are being presented as “news”. And like so much of the “news”, there’s a lot of incentive to cross over the line into *Fear-mongering * territory. And that’s what’s going on here.

    I’m positive many people shared your emotional reaction to this article. And I’m angry that the people who are responsible for this article are preying on the the very people they’re acting like they’re interested in helping.

    Love ♥️ and Light ✨ to you, my friend!

    1. Thank you for clarifying this. I am going to contact the original researchers to let them know this website is using their study for shameless click baiting.

      1. The original authors of the research are also the authors of this article, explaining their findings in layman’s terms. I am sure they would appreciate your feedback on both their published research and this article they wrote.

        1. Why are you now blocking perfectly legitimate comments? I have addressed this matter on the source The Conversation. I will ensure they are held accountable for this outrageous mischaracterization of already flawed research. And if you are actually a real science site then you will stop posting things like this. Science should have higher standards than disseminating trash like this.

  9. I spent my whole adult life being social. Now I am retired and spend all of my time by myself. I love it. I was so busy being social that I ignored myself. Now I am my own best friend and wouldn’t have any other way.

  10. I’m agoraphobic and pretty much just afraid to be around more than three people at a time. This makes social interaction difficult obviously. I have a hard time getting my thoughts out in an understandable way for most people, but other than that my biggest memory issues are me second guessing myself. I’ve been this way pretty much since birth and I was sheltered by my mother. My childhood and teenage years could be summed up as staring and my bedroom walls pretty much. I remember really odd things in different ways but I remember. Does this mean I will develope Alzheimer’s or dementia?

  11. The accusations are false I am not a social person and I don’t have lower brain cognitive control no one person is the same

  12. This is bullshit. They want everything to be social. That’s how they brainwash people into thinking this crap. Big pharma big med want you to think this shit. Solitude is fine

  13. That’s great. looks like I’m fucked and probably gonna have dimentia later in life. Thanks for letting me know!

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