It's around a year since Covid lockdown restrictions were imposed across the world, and heavy is the head that bears lockdown. Coping during this period of national incarceration has been a mental battle – and experts say the dramatic change to our lifestyles, coupled with unprecedented levels of stress, has aged our brains.
If you've been feeling more forgetful, unable to concentrate, and stumbling over the right words, you could be experiencing what's being referred to as "lockdown brain".
Absence of human contact has long been associated with a decline in cognitive function. In 1972, French explorer and scientist Michel Siffre conducted what would become one of the longest self-isolation experiments in history, shutting himself off in a cave in Texas for six months and documenting the mental impact. After a few months, Siffre wrote he "could barely string thoughts together". By the fifth month of isolation he had become so starved for company that he tried to befriend a mouse.
Over the ensuing decades, many studies have elaborated on the impact of time spent alone, such as the English Longitudinal Study of Ageing, which followed 6000 people with an average age of 65 over four years. Those who reported fewer social contacts at the beginning of the study showed the greatest decline in verbal fluency and memory recall by the end.
The godfather of social neuroscience, Professor John Cacioppo, who died in 2018 after decades studying the impact of social isolation on our brains, argued that we are hard-wired as a species to interact. If a human zoo should ever be designed, he argued, its inhabitants should come with the health warning: "do not house in isolation".
Professor Francis McGlone, a neuroscientist based at Liverpool John Moores University, says we should consider the brain as a muscle which needs to be exercised and challenged, with social interaction, novelty and variety. "The brain is a social organ," he says. "We are beginning to see some consequences in terms of memory, loneliness, depression and anxiety when you switch off that ability to socialise."
So what has lockdown done to our brains, and how can we undo the damage?
Monotony has depleted our memories
If you've been experiencing "brain fog" of late – walking into rooms and wondering why you had entered in the first place, for example – it's likely due to how repetitive our lives have become, says Catherine Loveday, professor of cognitive neuropsychology at the University of Westminster. She says the hippocampus (the area of the brain associated with memory) needs different, novel environments, plus physical space, to properly fire up. Having the same conversations with our families in the same room, day in day, out is a recipe for short-term memory decline.
Anecdotally, many are also reporting more moments of "tip of the tongue syndrome" – the phrase neuroscientists use when people experience words just out of reach. Being deprived of social interaction, office chit-chat and having new anecdotes to share with friends are all leading to a decline in verbal fluency.
James Law, professor of speech and language sciences at Newcastle University, says that for many adults, such a decline will be temporary until social interaction resumes.
What to do about it
Try a snooze – researchers in Germany have shown memory improves after taking a nap of 90 minutes or more.
Give your brain a workout by learning a new language, or spending dedicated time on anything outside your lockdown routine – it can even be something as simple as working for the day in a different room.
To improve your verbal fluency, the advice is to have as many proper conversations as possible – say hello to a stranger on your walk, or exchange a few words when buying groceries.
Isolation has caused our brains to shrink
Various studies have shown that people who are lonely have reduced brain volumes in the prefrontal cortex, which affects decision making and social behaviour. Prolonged isolation can affect the hippocampus (learning and memory) and the amygdala, which helps process emotion. If your brain is not constantly challenged through social interaction, its processing capacity begins to decline.
Loneliness causes the release of stress hormones, says Liz Ritchie, a therapeutic psychotherapist at Northampton-based mental health charity St Andrew's Healthcare.
"That impacts on neurotransmitters like dopamine, serotonin and adrenaline, which all play a key role in brain function and mood."
Last month researchers in Canada reported that months of social isolation can lead to a sharp increase in the rate of Alzheimer's disease among the elderly. The study, using medical data from 40,000 British people, found lonely people had a higher concentration of tissue, or grey matter, in the "default networks", the part of the brain that deals with imagination, hypothetical scenarios and memories and which is particularly susceptible to Alzheimer's disease.
What to do about it
Cacioppo's research on military veterans highlights some simple ways to protect against the effects of loneliness. Not allowing yourself to be buried in work and consciously making contact – even a brief exchange in the street – can make a difference, he argues, as well as making an effort each day to do something helpful for others.
He also recommends couples and families do chores together as it provides an opportunity to open up and reconnect.
Boredom has made our brains sluggish
Novelty is key in keeping our brains charged, and the lack of change in our lives similarly affects the ability to properly concentrate. From an evolutionary perspective our brains have adapted to respond to change and once we have learned something is not a threat, we tend to lose focus.
Loveday cites a recent experiment on sea slugs whereby scientists discovered that if you prodded the aquatic creature over a prolonged period of time it grew habituated to the threat and no longer bothered responding. In lockdown, she says, without anywhere to go or anything to do, we are all that sea slug.
"We respond to our circumstances and when they become very unchanging or undemanding it is absolutely to be expected people's concentration will go."
What to do about it
An easy solution to improving concentration, Loveday says, is introducing anything new into your daily routine. "Even walking down a new street or meeting a new person can wake the brain up again."
Screens killed our attention spans
Even prior to the pandemic our attention spans have grown shorter – now averaging roughly between three and six minutes. The switch to working from home, and huge increase in screen use during the pandemic, is likely to have made things worse.
Cal Newport, a computer science professor at Georgetown University and author of new book A World Without Email, says "context switching" between work, emails, messages and social media makes it much harder for the brain to concentrate.
What to do about it
Switching off notifications on devices can help, as can allocating different sections of the day to different tasks – for example, spending mornings on core work, and afternoons responding to emails, says Newport.
Dr Larry Rosen, emeritus professor at California State University, who has spent decades researching the link between technology and reduced attention span, suggests setting timers to train yourself to focus more wholly on individual tasks. Initially, he says, this should be for periods of 15 minutes and then moving up to 30 minutes when you are ready.
And when we're safely back in the office, try to have as much face to face communication with colleagues as possible.
Uncertainty has driven us to distraction
"Uncertainty," says Loveday, "is a huge zapper of cognitive energy." As humans we are constantly anticipating what is next by reflecting what has been and the problem at the moment is the future remains so unclear.
"We have this limited working memory capacity, which means we can only hold and manipulate a certain amount of information in our mind at any one time," she says. "If you are worrying about something or having to work harder on something it will take up that space."
The classic example Loveday gives, and one many of us will have experienced over the past year as we sit at our computers struggling to focus, is being interrupted when you are counting out money and needing to start again.
What to do about it
Move your body. Research published in January by scientists at Rutgers University in Newark, New Jersey, found older adults who took aerobic dance classes twice a week showed improvements in brain areas critical for memory and thinking.
Physical activity, especially when combined with socialising, will also boost your mood and offer a temporary distraction from worrying about the global health crisis.