Loneliness is wired into the human brain. Here's what it looks like.
A large study shows changes in the brain scans of lonely people in the area involved in imagination, memory, and daydreaming.
17 December, 2020
Credit: Adobe Stock
- A study of 40,000 participants shows specific signatures in the brain scans of lonely people.
- Loneliness is linked to variations in grey matter volume and connections in the brain default network.
- This area of the brain is connected to the use of imagination, memory, future planning, and daydreaming.
<p>COVID-19 has exacerbated the worldwide spread of loneliness that had been alarming researchers prior to the pandemic. A new study pinpoints a distinct signature that can be observed in the brains of lonely people and makes the case that social isolation leads to changes in the areas of the brain using memory and imagination.</p><p>The scientists defined loneliness as "the subjective perception of social isolation, or the discrepancy between one's desired and perceived levels of social connection." They based their findings on a large trove of information from about 40,000 participants aged 40 to 69. This was culled from UK's Biobank, an open-access to database for international health scientists. The researchers had access to magnetic resonance imaging (MRI) data, as well as genetics and psychological self-assessments.</p>
<p>The scientists compared the MRI data of the study participants who said they often felt lonely versus those who didn't and discovered key differences. These revolved around the <strong>default network</strong>, an area of the brain responsible for memories, as well as social cognition and imagination. It is employed when we focus on the past or think about the future or daydream about a different present.</p><p>Lonely people's default networks were wired together stronger and unexpectedly had more <strong>grey matter volume</strong>. Lonely people also seemed to show more preservation in the structure of the <strong>fornix</strong>—the nerve fiber bundle that transmits signals from the hippocampus to the default network.</p><p>What is responsible for the brain differences between people who feel lonely and those who don't? The scientists think the answer lies in the function of the default network. Lonely people tend to use their imagination, memories, and hopes more, contend the researchers, in an effort to manage their isolation.</p>
Scientists show what loneliness looks like in the brain
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="63156dc0c87a36da00d48a02eab00822"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/wkWpqlfA_2Q?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>The study's lead author, Nathan Spreng from The Neuro (Montreal Neurological Institute-Hospital) of McGill University in Canada, linked the use of the inner world by lonely people to their unexpected findings:<br></p><p style="margin-left: 20px;">"In the absence of desired social experiences, lonely individuals may be biased towards internally-directed thoughts such as reminiscing or imagining social experiences," stated Spreng in a <a href="https://www.mcgill.ca/neuro/channels/news/scientists-show-what-loneliness-looks-brain-325504" target="_blank">press release.</a> "We know these cognitive abilities are mediated by the default network brain regions. So this heightened focus on self-reflection, and possibly imagined social experiences, would naturally engage the memory-based functions of the default network."</p>
<p>The scientists think their research can help paint a fuller picture of loneliness and how to treat it, as the amount of people experiencing such feelings grows, affecting their health. <a href="https://pubmed.ncbi.nlm.nih.gov/25956016/" target="_blank" rel="noopener noreferrer">Studies</a> on older people showed loneliness was linked to a stronger risk of dementia and cognitive issues.</p><p style="margin-left: 20px;">"Human evolution has been shaped by selection pressures towards enhanced inter-individual cooperation, write the scientists in their <a href="https://www.nature.com/articles/s41467-020-20039-w" target="_blank">study</a>. "Social interactions are crucial for survival, and fulfillment. Our species' extraordinary reliance on other individuals has led to the characterization of humans as the "ultra-social animal". Consequently, the absence of sufficient social engagement can impose substantial physical and psychological costs."</p><p>Check out the study, published in the journal <a href="https://www.nature.com/articles/s41467-020-20039-w" target="_blank">Nature Communications.</a></p>
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Humans are not the only animals that self-medicate
Research shows that sparrows and other animals use plants to heal themselves.
09 December, 2020
Credit: phichak/Adobe Stock
- Researchers find that russet sparrows are among the many animals that self-medicate.
- It's not clear whether this pervasive capability is learned behavior or instinctive.
- It's likely animals have discovered some remedies we don't yet know about.
<p>This week, researchers from China published a <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(20)31525-6" target="_blank">study</a> in which an intriguing behavior of russet swallows was described. The birds apparently administer what amounts to preventative medicine to their offspring: wormwood that kills parasites and promotes growth. This suggests two things: that they understand the beneficial properties of the plant, and that they are aware of and invest in their chicks' future.</p><p>Remarkable as this may seem, the sparrows are just the latest addition to an already long list of animals that self-medicate, a capability that raises big questions. Is this behavior learned or is it instinctual? Is the knowledge shared among animal communities and families? Do animals try out different substances until they feel better? Does illness simply induce a physical taste for beneficial plants? Has natural selection favored the survival of animals who just happen to ingest medicinal substances?</p><p>The field of study that looks at animals who self-medicate is called <em>zoopharmacognosy</em>. "I believe every species alive today is self-medicating in one way or another," Michael Huffman of the Primate Research Institute at Kyoto University told the <a href="https://www.nytimes.com/2017/05/18/magazine/the-self-medicating-animal.html" target="_blank">New York Times</a> in 2017. "It's just a fact of life."</p>
Animal pharmacists
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDk0MjIwMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NjU2MTA3OX0.dDunXAmY_nt9cVj7bTvR1GIblfDifR_Feodv7Fg0vVI/img.jpg?width=980" id="b6f6b" class="rm-shortcode" data-rm-shortcode-id="af091db92f286d9d168da2451a442db7" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />Credit: karenkh/Adobe Stock
<p>In that New York Times article, Huffman tells the story of a chimp he observed named Chausiku who treated a malaise by chewing the juice from the <em>Vernonia amygdalina</em> plant. According to a local ranger, the plant contains potent medicine but is also deadly at larger doses. Chausiku somehow knew just how much juice to ingest, and she recovered her energy in a few days. She recovered with a powerful appetite, suggesting the resolution of some manner of intestinal distress. Subsequent testing of the plant revealed it has multiple compounds with strong anti-parasitic qualities.</p><p>It seems clear that this sort of medicinal savvy is widespread throughout the animal kingdom. A PNAS article was <a href="National%20Center%20for%20Biotechnology%20Information" target="_blank">shared</a> by the National Center for Biotechnology Information in 2014. It noted, among other examples:</p><ul><li>Reports of bears, deer, and elk consuming medical plants.</li><li>Elephants in Kenya that induce delivery of their calves by eating certain leaves.</li><li>Lizards that eat a particular anti-venom root when bit by a snake.</li><li>Red and green macaws that ingest clay that calms their digestion (dirt antacids!) and kills bacteria.</li><li>Female wooly spider monkeys in Brazil whose fertility is enhanced by eating certain plants.</li></ul><p>It may be primates who are most adept at self-medicating. Chimpanzees, bonobos, and gorillas are often seen swallowing rough leaves that clear their digestive tracts of parasites. Chimps with roundworms will also eat terrible-tasting plants that cure such infestations.</p><p>Numerous animals—such as the sparrows noted earlier and certain caterpillars—eat plants that kill or repel parasites.</p><p>Those russet sparrows aren't the only ones who seem to be planning head, either. There are ants that use antibacterial spruce-tree resin to keep their nests germ free. Finches and sparrow line their nests with cigarette butts that keep mites under control.</p>Animal science, luck, and/or instinct?
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDk0MjIwNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNDg3MDk2OH0.92VlwYZMrIqtctCl0v23vaWlBXLzbyFicDovEBaPvWY/img.jpg?width=980" id="8fa28" class="rm-shortcode" data-rm-shortcode-id="276c7472b74b6591f8150b8bee7b5534" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="617" />Credit: Thaut Images/Adobe Stock
<p>If science is the practice of making observations, particularly of cause and effect, it may be that these animals are practicing a science of their own. As psychologist Robin Dunbar tell the Times, this method is simply how people and other living beings work out the way things work: "Science is a genuine universal, characteristic of all advanced life-forms."</p><p>An animal's source of medical knowledge may be as simple as that which comes to an individual with digestive issues who just happens to eat a plant that makes them feel better, a bit of knowledge that will come in handy when it once again gets sick. Perhaps others nearby see what's happened and learn the trick to recovering from a stomach ache themselves. Perhaps offspring learn the medicine by observing their adults. Emory University's <a href="http://www.biology.emory.edu/research/deRoode/" target="_blank">Jaap de Roode</a>, speaking with <a href="https://www.npr.org/sections/health-shots/2013/04/09/176694090/on-call-in-the-wild-animals-play-doctor-too?/" target="_blank" rel="noopener noreferrer">NPR</a>, says that "primates are not so different from us. They can learn from each other and they can make associations between ... taking medicinal plants and feeling better."</p><p>On the other hand, it could also be natural selection at work. An animal with a natural inclination toward this kind of plant may ingest it when its tummy hurts. It then survives to reproduce while other individuals with tummy aches don't. The animal uses the plant medicinally without any particular knowledge or understanding.</p><p>"People used to believe that you had to be very smart to [self-medicate]," says de Roode, but this may not be so. He cites the example of parasite-infected monarch butterflies who will lay their eggs in anti-parasitic milkweed, given the option. "I wouldn't say it's a conscious choice, but it's a choice," he says, since healthy monarchs don't exhibit such a preference.</p><p>However this works, experts say we would be wise to keep an eye on all these non-human practitioners — there may be cures they know about that human physicians haven't yet caught onto. As de Roode says, animals "have been studying medicine much longer than we have."</p>
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Zebrafish give new insight to sound sensitivity in autism
These tiny fish are helping scientists understand how the human brain processes sound.
24 November, 2020
Credit: peter verreussel / Adobe Stock
- Fragile X syndrome is a genetic disorder caused by changes in a gene that scientists call the "fragile X mental retardation 1 (FMR1)" gene. People who have FXS or autism often struggle with sensitivity to sound.
- According to the research team, FXS is caused by the disruption of a gene. By disrupting that same gene in zebrafish larvae, they can examine the effects and begin to understand more about this disrupted gene in the human brain.
- Using the zebrafish, Dr. Constantin and the team were able to gather insights into which parts of the brain are used to process sensory information.
<p>Associate professor Ethan Scott and Dr. Lena Constantin <a href="https://www.sciencedaily.com/releases/2020/11/201110102527.htm" rel="noopener noreferrer" target="_blank">recently carried out a study</a> using zebrafish that carry the same genetic mutations as humans with "Fragile X" syndrome and autism. During their research, they discovered the neural networks and pathways that produce hypersensitivities to sound in both zebrafish and humans. </p><p><strong>What is Fragile X syndrome? </strong></p><p><a href="https://www.cdc.gov/ncbddd/fxs/facts.html" rel="noopener noreferrer" target="_blank">Fragile X syndrome</a> (commonly referred to as FXS) is a genetic disorder caused by changes in a gene that scientists call the "fragile X mental retardation 1 (FMR1)" gene. This gene typically makes a protein called fragile X mental retardation protein (FMRP) that's needed for typical brain development. The brains of people with FXS do not make this protein, and if it is there, it's abnormal. </p><p><strong>What is autism? </strong></p><p><a href="https://www.cdc.gov/ncbddd/autism/facts.html" rel="noopener noreferrer" target="_blank">Autism spectrum disorder</a> (ASD) is a developmental disability that can cause significant social, communication, and behavioral challenges. People with ASD may communicate, interact, behave, and learn in different ways than most other people. A current diagnosis of ASD now includes several conditions that were previously diagnosed separately such as autistic disorder, pervasive developmental disorder, and Asperger syndrome.</p>
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By disrupting a specific gene in Zebrafish, we're able to better understand the same disruption of that gene in humans with FXS or autism.
Credit: slowmotiongli on Adobe Stock
<p>"Loud noises often cause sensory overload and anxiety in people with autism and Fragile X syndrome -- sensitivity to sound is common to both conditions," <a href="https://www.sciencedaily.com/releases/2020/11/201110102527.htm" target="_blank">Dr. Constantin explained to Science Daily</a>.</p><p><strong>How do zebrafish relate to humans with autism? </strong></p><p>According to the research team, FXS is caused by the disruption of a gene. By disrupting that same gene in zebrafish larvae, they can examine the effects and begin to understand more about this disrupted gene in the human brain. </p><p>The thalamus, according to Dr. Constantin, works as a control center, relaying sensory information from around the body to different parts of the brain. The hindbrain then coordinates different behavioral responses. Using the different sound tests, the team was able to study the whole brain of the zebrafish larvae under microscopes and see the activity of each brain cell individually. </p><p>According to Dr. Constantin, the research team recorded the brain activity of zebrafish larvae while showing them movies or exposing them to bursts of sound. The movies stimulated movement, a reaction to the visual stimuli that was the same for fish with the Fragile X mutation and those without. However, when the fish were given a burst of white noise, there was a dramatic difference in the brain activity of the fish with the Fragile X mutation.<br></p><p>After seeing how the noise radically affected the fish brain, the team designed a range of 12 different volumes of sound and found the Fragile X model fish could hear much quieter volumes than the control fish. </p><p>"The fish with Fragile X mutations had more connections between different regions of their brain and their responses to the sounds were more plentiful in the hindbrain and thalamus," <a href="https://www.sciencedaily.com/releases/2020/11/201110102527.htm" target="_blank">said Dr. Constantin</a>.</p><p>Essentially, the fish with Fragile X mutation had more connections between the regions of their brain and so their responses to the sounds were more notable. </p><p><strong>Understanding how this gene disruption works in zebrafish will give us a better understanding of sound hypersensitivity in humans with FXS or autism.</strong> </p><p>"How our neural pathways develop and respond to the stimulation of our senses gives us insights into which parts of the brain are used and how sensory information is processed," Dr. Constantin said.</p><p>Using the zebrafish, Dr. Constantin and the team were able to gather insights into which parts of the brain are used to process sensory information. </p><p>"We hope that by discovering fundamental information about how the brain processes sound, we will gain further insights into the sensory challenges faced by people with Fragile X syndrome and autism."</p>
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Are brain teasers and apps a waste of time?
Recent research shows that brain teasers don't make you smarter and don't belong in job interviews because they don't reflect real-world problems.
13 November, 2020
Credit: Fletcher Pride on Unsplash
- There is little research to prove that brain games improve general cognition or slow cognitive decline. Rather they simply make you better at playing that specific brain game.
- Brain teasers are a useless tool during job interviews as they can't predict how an interviewee will perform in real world tasks relevant to the job role.
- Exercise, nutrition, socialization, and meditation are probably better brain boosters.
<p>Brain training apps and programs have sky-rocketed into a billion-dollar market over the past decade. While the promise of revving up intelligence is certainly alluring, the research as to whether or not they actually do anything for your cognitive abilities is dubious. </p>
Why brain training apps dont boost cognition
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDc3ODU2NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY1ODE5MTU3NX0.WnGU3mz2yMZx1IdQKUOhmvOmry_vjuWrBD3nzy4Yy0w/img.jpg?width=1245&coordinates=0%2C0%2C0%2C0&height=700" id="0cf0e" class="rm-shortcode" data-rm-shortcode-id="f70c82d4dcfecf4a45e7e94e59436f92" data-rm-shortcode-name="rebelmouse-image" alt="brain model" data-width="1245" data-height="700" />Credit: Robina Weermeijer on Unsplash
<p><a href="https://www.sciencedaily.com/releases/2017/04/170417095528.htm" target="_blank" rel="noopener noreferrer">A 2017 study</a> conducted by a team of psychologists at Florida State University sought to learn whether brain training games could boost "working memory" in subjects, and consequently the cognitive abilities of reasoning, memory, and processing speed. One group of participants played a brain-training video game called "Mind Frontiers," while another group played crossword games or number puzzles.</p><p>"Our findings and previous studies confirm there's very little evidence these types of games can improve your life in a meaningful way," said Wally Boot, an expert on age-related cognitive decline at FSU who was involved in the study. Another 2017 report monitoring the cognitive skills, brain activity, and decision-making abilities of young adults, concluded that brain-training games "<a href="https://www.medicalnewstoday.com/articles/318374" target="_blank" rel="noopener noreferrer">do not boost cognition</a>." </p><p>What brain games likely do is make you better at playing that specific brain game. Learning is the result of two potential processes that happen to neuron cells in the brain. One is called "long term potentiation," in which already existing connections between neurons are strengthened by firing together in reaction to incoming signals. The other is called "dendritic spine growth." In this process, neurons form new connections with each other by wiring together through a process in which the surface area of dendrites (antenna-like structures that make up the receiving end of a neuron) increases allowing for more neurons to connect with one another. </p><p>In short, "cells that fire together wire together," and when you play brain games, neural connections in the brain network that are engaged while performing the tasks in the game are strengthened. Thus, you may become a genius at solving a particular word puzzle, but there is little evidence to suggest that you will become any better at other puzzles, let alone enhance your cognitive abilities in general. And because those puzzles are so decontextualized from situations you would likely encounter in real life, they are probably useless. </p><p>This was backed up by <a href="https://pubmed.ncbi.nlm.nih.gov/30009838/" target="_blank" rel="noopener noreferrer">a 2018 study</a> in which neuroscientists at Western University in Ontario, Canada, investigated if the cognitive skills acquired from brain-training tasks could be transferred to other tasks that engage the same brain regions. They found no evidence to support that idea. In fact, <a href="https://www.frontiersin.org/articles/10.3389/fnhum.2017.00248/full" target="_blank" rel="noopener noreferrer">video games may do more for your brain.</a></p>Brain teasers don't reflect future job performance
<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDc3ODU2Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNzQyODgwOH0.LcOdRnyLQz6bKyI6N5WGmodQYL2_elOY4K3EArC-s-w/img.jpg?width=1245&coordinates=0%2C405%2C0%2C405&height=700" id="e143b" class="rm-shortcode" data-rm-shortcode-id="3fada375c74e57b7a214b19a0c6a10f8" data-rm-shortcode-name="rebelmouse-image" data-width="1245" data-height="700" />Google logoCredit: Kai Wenzel on Unsplash
<p>So brain puzzles may not do much to boost IQ, but does the ability to work through brain teasers predict intellect or job performance? Afterall, Google, once notorious for its use of brain teasers in job interviews, decided they were "<a href="https://www.nytimes.com/2013/06/20/business/in-head-hunting-big-data-may-not-be-such-a-big-deal.html?pagewanted=all" target="_blank">a complete waste of time</a>" years ago. (A list of some of the tech giant's interview questions <a href="https://www.businessinsider.com/15-google-interview-questions-that-used-to-make-geniuses-feel-dumb-2012-11#how-many-golf-balls-can-fit-in-a-school-bus-1" target="_blank">can be found here</a>, for those curious.)</p><p>"They don't predict anything," Laszlo Bock, senior vice president of people operations at Google, <a href="http://www.nytimes.com/2013/06/20/business/in-head-hunting-big-data-may-not-be-such-a-big-deal.html?pagewanted=all" target="_blank" rel="noopener noreferrer">told the New York Times</a> in 2013. "They serve primarily to make the interviewer feel smart."</p><p>The reason is that while the brain teasers may measure how fast an individual can generate a smart or accurate solution to an abstract problem under pressure, they have little to do with future problems the employee will encounter in the job. Furthermore, the environment in which the brain teaser is asked favors certain personality traits that may be irrelevant to job performance and which do not necessarily reflect intelligence. For example, an introvert whose nerves may impede his or her ability to communicate a quick and creative solution in the context of a job interview. Or, perhaps, a detail, sensory-oriented individual whose problem-solving strength lies in tangible and immediate situations rather than abstract imaginings. </p><p>In short, an employee who can come up with high quality ideas and solutions in situations relevant to a specific job role is far more valuable than one who can come up with a fast idea to a brain teaser that has nothing to do with the company's goals. </p>Better brain boosters
<p>The science on brain training games and teasers is a mixed bag. However, if you're looking for more effective ways to boost your cognition or prevent cognitive decline, here are some that are better backed by research:</p><ul><li><strong>Run or walk.</strong> Several studies have suggested that the parts of the brain that govern thinking and memory are greater in volume in individuals who regularly exercise as opposed to those who don't. What's more, some research has found that engaging in regular exercise of moderate intensity over six months to a year is correlated with an increase in the volume of selected brain regions. Most of this research has focused on aerobic exercise.<br><br> </li><li><strong>Meditate.</strong> Multiple studies have shown that regular mindfulness meditation increases grey matter in the brain, which equates with more neuronal activity and better performance, in certain areas. Research has also found that mindfulness meditation <a href="http://jtoomim.org/brain-training/Zeidan2010_Mindfulness_Meditation.pdf" target="_blank" rel="noopener noreferrer">improves cognition</a>.<br><br> </li><li><strong>Socialize. </strong>Frequent social activity may help to <a href="https://www.health.harvard.edu/newsletter_article/the-health-benefits-of-strong-relationships" target="_blank">delay cognitive decline</a> in old age and boost current cognition. This is because social situations and the development of relationships requires our minds to engage multiple neural networks that are relevant to healthy daily function.<br><br> </li><li><strong>Prioritize nutrition.</strong> "Brain-boosting" foods like fish, dark chocolate, antioxidant-rich berries, and foods with B vitamins like eggs can help build and repair brain cells. </li></ul>
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COVID-19 may cause 'significant' cognitive deficits, study says
A growing body of research suggests COVID-19 can cause neurological damage in some patients.
28 October, 2020
Feydzhet Shabanov via AdobeStock
- The study examined data of cognitive performance collected from more than 84,000 people, more than 12,000 of whom had likely contracted and recovered from COVID-19.
- Compared to healthy participants, the COVID-19 group performed significantly worse on cognitive tests.
- Mental decline in the worst cases were the equivalent of ageing by 10 years.
<p>A new study adds to the <a href="https://bigthink.com/coronavirus/covid-19-brain" target="_blank">growing body of research</a> suggesting COVID-19 may leave some patients with neurological damage.</p><p>The preprint study — which is <a href="https://www.medrxiv.org/content/10.1101/2020.10.20.20215863v1.full" target="_blank">published in medRxiv</a> and has yet to be peer reviewed — examined cognitive test data from 84,285 people, more than 12,000 of whom had either tested positive for COVID-19 or had likely contracted the disease based on previous symptoms.</p><p>The data was collected from the Great British Intelligence Test, which measures cognitive performance in areas like semantic reasoning abilities, spatial problem solving and verbal working memory, to name a few.</p><p>The results showed that people who contracted and recovered from COVID-19 were significantly more likely to score lower on the tests. What's more, people with more severe cases of the disease tended to show greater cognitive deficits.</p><p>Because the researchers didn't have data on participants' cognitive abilities before the pandemic, they compared the scores of the COVID-19 group with a group of healthy controls.</p><p style="margin-left: 20px;">"People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders," the researchers wrote in the study. "They were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty."</p>
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The effect size of cognitive deficits varied across three cognitive domains, which were estimated by applying principal component analysis with varimax rotation to the nine test summary scores.
Hampshire et al.
<p>Participants who suffered the most severe cases of COVID-19, and had to be put on a respirator, showed cognitive "equivalent to the average 10-year decline in global performance between the ages of 20 to 70." For comparison, the study notes that the difference in cognitive performance between this group and the control "equates to an 8.5-point difference in IQ."<br></p><p>The COVID-19 group scored particularly low on tests measuring semantic problem solving and visual selective attention.</p><p style="margin-left: 20px;">"People who have recovered from COVID-19 infection show particularly pronounced problems in multiple aspects of higher cognitive or 'executive' function, an observation that accords with preliminary reports of executive dysfunction in some patients at hospital discharge," the researchers wrote.</p><p>Considering that all participants had recovered from the disease when they completed the cognitive tests, the results suggest that "COVID-19 infection likely has consequences for cognitive function that persist into the recovery phase," the researchers wrote.</p><p>Still, it's unclear whether these deficits (if indeed caused by COVID-19) are permanent, or how long they may last. But there is evidence suggesting that severe respiratory conditions can cause neurological damage. A <a href="https://link.springer.com/article/10.1186/s13054-019-2626-z" target="_blank">2011 study</a>, for example, found that people who'd been hospitalized with acute respiratory distress syndrome can suffer cognitive deficits that persist up to five years after discharge.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYyNzk1Ny9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY2OTU1MjUwMX0.GYEGLdyq2oEfHB1vP5xU-dR5m61uoeRPeWRu_kVEFtQ/img.png?width=980" id="0f97e" class="rm-shortcode" data-rm-shortcode-id="e70e7ab26f9f41c66ae98dd97fb025dd" data-rm-shortcode-name="rebelmouse-image" data-width="1230" data-height="789" />
The Block Rearrange test [featured in the Great British Intelligence Test] measures spatial problem solving.
Credit: Hampshire et al.
<p>It's worth noting the study is limited, mainly because it didn't compare before-and-after cognitive performance of the COVID-19 group. Another possible limitation: People with lower cognitive abilities may be more likely to contract COVID-19 because they're more likely to put themselves in harm's way.</p><p style="margin-left: 20px;">"We consider such a relationship plausible; however, it would not explain why the observed deficits varied in scale with respiratory symptom severity," the researchers wrote. "We also note that the large and socioeconomically diverse nature of the cohort enabled us to include many potentially confounding variables in our analysis."</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYyNzk2MS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY2NzUyOTgxOX0.l6i9JnfM-3FGHeNUMQWf19f4g_SqPrce5AJMfSNR5I4/img.png?width=980" id="d44ac" class="rm-shortcode" data-rm-shortcode-id="76b5f48c920a441400e0b8965ad2cbe0" data-rm-shortcode-name="rebelmouse-image" alt="Doctors treating a COVID-19 patient" data-width="689" data-height="478" />
San Diego-area hospitals treat coronavirus patients during COVID-19 pandemic
Credit: Mario Tama/Getty Images
<p>Only time and further research will tell whether COVID-19 leaves people with lasting cognitive deficits. Scientists are already establishing long-term research projects to answer these questions, such as the <a href="https://www.cambridgebrainsciences.com/studies/covid-brain-study" target="_blank" rel="noopener noreferrer">COVID-19 Brain Study</a>, which aims to monitor the long-term health of 50,000 participants who have tested positive for the disease.</p><p>If you've been diagnosed with COVID-19 and want to enroll in the study, visit <a href="https://www.cambridgebrainsciences.com/studies/covid-brain-study" target="_blank" rel="noopener noreferrer">cambridgebrainsciences.com/studies/covid-brain-study</a>.</p>
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