Innholdsfortegnelse for EG20 i New Scientist - The Essential Guides

YOU know your mind. It couldn’t be more familiar: after all, it is basically the essence of you. It somehow generates the very feeling of existing and experiencing the world around you. It drives your behaviours and is the window through which you interpret the world. In our daily lives, most of us don’t tend to spend much time thinking about the mind, and there is probably a good reason for that. When we start to examine the mind through a scientific lens, things become far more uncertain than they intuitively feel. As one scientist quoted in this guide attests, we know more about outer space than we do about our own minds. Even so, there are plenty of good reasons to embark on this endeavour, which is both scientific…

AT FIRST, it seems obvious. Memory is about the past. It is your personal database of things you have experienced. In fact, this repository has a purpose that goes way beyond merely recalling information. Some of the best evidence of this came from studies of people with brain damage or amnesia. One iconic case was of a person known as KC in the early 1980s. After a motorcycle accident, he was left with an impaired episodic memory: he could remember facts, but not personal experiences. The weird thing was, it also stopped him doing something else entirely. He was unable to imagine the future. We now know there is a strong link between being able to remember past events and being able to plan for the future. Imaging studies, for…

IT IS becoming increasingly clear that to really understand mental health, you need to factor in just how much the brain cares about what is going on below the neck. For any animal, survival depends on how well it can detect physical changes that may signal a threat and to take appropriate action to get things back on track. Interoception – the ability to detect these bodily changes, from heartbeat to changing concentrations of certain hormones in the blood, as well as the psychological expression of these as feelings and emotions – is a bit like our sixth sense. Integrated by the brain, these changing bodily sensations feed into our mental state and behaviour, consciously or unconsciously, and have a say in every thought and emotion we have. “Interoception is…

THE placebo effect is a mysterious phenomenon that happens when someone’s medical symptoms are lessened through the power of suggestion and expectation – for instance, if someone’s illness improves after taking a “medicine” known to be ineffective. We don’t know how it happens, but it can be seen in many different conditions, including chronic pain, nausea, high blood pressure and immune disorders, and can be triggered by pills, injections, surgery or even just an authority figure predicting that a medical treatment will help. It is an impressive demonstration of the power of mind over matter. Careful experiments have shown that the power of the placebo effect depends on surprising factors like the appearance of the tablets and a doctor’s bedside manner. Coloured pills work better than white ones; injections and…

According to an increasingly popular concept in cognitive neuroscience called predictive processing, yes. The bedrock idea is simple. Imagine that you are your brain, locked inside the bony vault of the skull, trying to figure out what is out there in the world – a world that, from the perspective of the brain, also includes the body. All you have to go on are noisy and ambiguous sensory signals, which are only indirectly related to what is out there and certainly don’t come with labels attached (“I’m from a cup of coffee! I’m from a tree!”). Perception, in this view, has to be a process of inference – of neurally implemented, probabilistic guesswork. When I see a red coffee cup on the table in front of me, this is because…

DEFINING a “thought” is tricky. We assume we are all talking about the same thing – a conscious mental state – but, in fact, everyone has their own ideas. Our thoughts seem to include five common phenomena: inner speech, inner seeing, feelings or emotions, sensory awareness (such as the sensation of your shoe rubbing) and unsymbolised thinking (explicit thoughts that don’t include the experience of words, images or symbols). ← Chapter 1 has an introduction to inner speech and thoughts What has become clear is that we all think using our own combination of phenomena. A single thought might contain five or more separate, simultaneous images along with inner speech about something else entirely. Even something as straightforward as inner speech isn’t just one thing. It can take the form…

ADHD is officially diagnosed following the guidance in the Diagnostic and Statistical Manual of Mental Disorders or the World Health Organization’s International Classification of Diseases. Both set out more or less the same criteria for diagnosis. There are symptoms of inattention, such as being easily distracted or making careless mistakes, and of hyperactivity, such as having trouble sitting still and interrupting people. Adults must have at least five of these symptoms (for children it is six) and these must have been around since before they were 12 years old. They must manifest in more than one setting, such as their work, home and social life. On top of that, all this must negatively affect their ability to function in those settings. If you tick all those boxes, then a doctor…

DEPRESSION is one of the biggest medical problems worldwide. Low mood and a lack of ability to take pleasure from usual activities are its two core features, often accompanied by a range of physical symptoms, such as appetite loss, fatigue and insomnia. → For more on insomnia, see page 74 The idea that depression is caused by a chemical imbalance in the brain arose in the 1960s, after a medicine aimed at treating low blood pressure was found to trigger low mood in some people. The drug, it turned out, reduces serotonin as well as two other brain chemicals, noradrenaline and dopamine. Antidepressants were then developed that raised one, two or all three of these substances. One of the first was fluoxetine (Prozac), which blocks removal of serotonin from synapses,…

The symptoms of post-traumatic stress disorder (PTSD) include recurrent disturbing memories, dreams or flashbacks; stress reactions to certain cues; avoidance behaviours; low mood; and feelings such as guilt or shame. Importantly, however, an experience can’t be termed traumatic unless it fits with a list of potential traumas. This list has widened over the years and today includes actual or threatened death, serious injury and sexual violence. A person must have experienced, witnessed or had repeated professional exposure to one of these events in order to qualify for a PTSD diagnosis. It is perfectly normal to experience some PTSD symptoms after a potentially traumatic event. Someone who has been in a car accident and sustained minor injuries, for instance, might have dreams about the accident, flinch at the sound of screeching…

BRAIN fog, as a term, has been used intermittently since the 1800s as a way to characterise sluggish cognition, but it became popular in the 1990s to describe the experience of living with chronic fatigue syndrome (CFS) and some autoimmune conditions. Brain fog isn’t a medical condition in its own right, however, and there are no diagnostic criteria. Rather, it is an umbrella term that covers a wide range of cognitive symptoms, including a lack of mental clarity, memory problems and an inability to focus. It disproportionately affects women. Today, there are dozens of conditions associated with brain fog, including allergies, menopause, attention deficit hyperactivity disorder (ADHD) and kidney failure, as well as mental health conditions such as anxiety and depression. Because of this, it is hard to pin down…

THE idea that nature can give us a mental pick-me-up became popular in the 1980s, after studies demonstrated its calming effects on both body and mind, reducing heart rate, stress hormones and blood pressure. That boost is now known to go further, helping with happiness and well-being, as well as attention, creativity, memory and more. It can also aid sleep, reduce stress, promote positive social interactions and even help generate a sense of meaning to life. Research even shows it can help people experiencing anxiety or depression and ameliorate some symptoms of conditions such as ADHD. ← See page 57 for the ADHD diagnosis explosion People are substantially happier when they are in nature of any kind compared with an urban environment, research shows, even after controlling for things like…

It is easy to picture a brain, but much harder to visualise a mind. Intuitively, we have a sense of what a mind is, and we know how it feels to have one, yet a definition is harder to come by. This is a topic that has puzzled scientists and philosophers for millennia. As studies of the human brain advance rapidly, we are beginning to understand much more about how the mind works and why things can go wrong, but even that doesn’t answer the question of how the machinations of the brain construct the mind. Another approach is to break the mind down into some of its constituent parts, then use those as building blocks with which to rebuild our picture of the mind as a whole.…

CONSCIOUSNESS is, for each of us, all there is: the world, the self, everything. But consciousness is also subjective and difficult to define. The closest we have to a consensus definition is that consciousness is “something it is like to be”. There is something it is like to be me or you – but presumably there is nothing it is like to be a table. How our conscious experiences arise is a long-standing question, one that has perplexed scientists and philosophers for hundreds, if not thousands, of years. The orthodox scientific view today is that consciousness is a property of physical matter, an idea we might call physicalism or materialism. But this is by no means a universally held view, and even within physicalism there is little agreement about how…

WHAT was the last thing you said to yourself in your head? A warm word of encouragement or a scathing put-down? The question of our inner voice is wrapped up in some even bigger questions, such as those concerning the nature of consciousness, our sense of self and how our inner life affects our behaviour. For that reason, a small band of researchers is dedicated to understanding more. It is challenging work, not least because it is impossible to truly listen in on someone else’s inner world. But we are beginning to grasp where inner speech comes from, how it differs between people, its contribution to cognitive skills like memory and its relationship with mental health. In the 1930s, psychologist Lev Vygotsky found that our capacity for inner speech develops…

MEDITATE Styles of meditation, such as mindfulness, that encourage noticing bodily signals and then letting them go may counter the runaway body-mind pathways that can contribute to anxiety. STIMULATE THE VAGUS NERVE DIY ways to do this include breathing at a rate of six breaths per minute, splashing your face in cold water or shutting your eyes and extremely gently pressing on your eyeballs. GET MOVING Sedentary lifestyles leave us out of touch with our bodily signals. Raising your heart and breathing rate via exercise may help to increase sensitivity in a controlled way and to better put them in context. FLOAT Floatation tanks take away external sensory information and help you tune in to your heartbeat and breathing. It may also reduce gut discomfort in eating disorders.…

CAFFEINE: If a strong espresso sets your nerves jangling, that may be largely due to your expectations. Even pure water increased alertness and raised blood pressure in volunteers who were told it contained caffeine. As for those withdrawal symptoms when you can’t get your morning cup of joe, they might be all in your head, too. SPORTS SUPPLEMENTS: There is little scientific backing for many of these products, but studies show that people only have to believe they are taking performance enhancers or energy drinks to show greater stamina and strength. Even the effects of steroids may be boosted by a placebo response. DESIGNER BRANDS: Are they really better than generics? Not necessarily. People tricked into thinking they were wearing designer sunglasses could more easily decipher small writing through the…

BACTERIA have been associated with sickness almost since they were discovered 350 years ago by biologist and microscope pioneer Antonie van Leeuwenhoek. It wasn’t until the 21st century that we got the first hint microbes might also influence how we feel. It started with very clean mice. In 2004, Nobuyuki Sudo at Kyushu University, Japan, found that mice lacking microbes had an abnormal response to stress. These so-called germ-free mice are born through antiseptic caesarean sections and raised in a sterile environment. Such animals don’t exist in nature because microbes are inescapable: they coat the skin and are especially fond of the mucous lining of the gut. They accumulate in the colon, which has the right conditions to support a dense population of bacteria, fungi and viruses. Without a protective…

Why are we prejudiced? What happens in our brains when we make assumptions about people who look or speak differently to us? Working with Susan Fiske at Princeton University, Lasana Harris researches the brain mechanisms underlying dehumanisation and has revealed the surprising ease with which we can stop ourselves from having empathy for the plights of others. Dehumanisation is a horrifying word, and yet your work suggests it is something we all do. Why is that? Firstly, if I want to do something to another human being that is something I don’t typically like doing to human beings, then I’m going to need to not think about their mind while I do it. The other reason is that dehumanisation is a way to regulate emotional responses, preventing us from identifying…

Professional goalkeepers in football are quicker at processing information from different senses than players in other positions, which could explain why they are so good at making split-second decisions on the field. David McGovern at Dublin City University in Ireland and his colleagues wondered whether goalkeepers’ unique role meant that they perceived the world differently to the rest of the team. “Goalkeepers have to make decisions quickly with limited information,” he says. To investigate, they recruited 20 professional goalkeepers, 20 other players and 20 people who didn’t play professional football, all of whom were men. Each person was shown one or two images that flashed briefly on a screen, followed by one, two or zero beep sounds. Typically, when one flash and two beeps are shown in close succession, people…

AROUND 1 in 20 of us experiences a strange connection between our senses. For these people, words may take on a certain colour, or music might evoke a particular taste or texture. This condition is named synaesthesia. Famous synaesthetes include artists such as David Hockney and Wassily Kandinsky, and studies have found that people with synaesthesia are more likely than the rest of the population to pursue creative hobbies like painting or poetry. Scientists have known about synaesthesia for more than 200 years, but there was little scientific interest in it. What gives rise to this peculiar trait remains poorly understood, but research on the subject has now picked up and we have some ideas. As infants, our brains cells have millions of connections that are pruned away as we…

UNWANTED thoughts that get stuck in your head can be a symptom of various mental health conditions, including anxiety, depression and obsessive compulsive disorder. But intrusive thoughts are far more common than you might imagine. For instance, 64 per cent of women and 56 per cent of men experience intrusive thoughts about driving a car off the road. But it doesn’t explain why certain thoughts – often dark ones – get stuck in our minds. Ethan Kross at the University of Michigan calls this “chatter” and notes that it usually entails thinking about oneself – your experiences, emotions, desires and needs. “We become flooded with emotion and we lose sight of the bigger picture where solutions to our problems often lie,” he says. Everyone gets this from time to time,…

DEMENTIA usually strikes people in older age, leading them to become progressively more forgetful and confused. It is becoming the leading cause of death in many Western countries. Some of this is down to doctors being more willing to put dementia on death certificates, but there is also a real rise. Dementia doesn’t kill directly, but by making people frailer and less able to eat, it leaves them vulnerable to infections like pneumonia. There is no effective treatment for dementia. But those who have it can be helped with practical approaches like music therapy or reminiscence therapy, in which people are encouraged to talk about memories from their past. The most common form of dementia is Alzheimer’s disease, characterised by a build-up of clumps in the brain, formed of proteins…

Hypnosis doesn’t have a reputation as being particularly scientific, but perhaps surprisingly, it may help in the treatment of mental health conditions. A hypnotic “trance” can be described as a state of focused attention, concentration and inner absorption, accompanied by a loss of awareness of the other things around you. It is a state you are likely to have experienced before – when you have been so absorbed in an activity that you don’t notice anything around you or the passage of time. In 2018, research found that hypnosis reduced anxiety, with the average participant who received it showing more improvement than 84 per cent of people who didn’t receive it. What’s more, there was no difference in benefit between those who used self-hypnosis and those given guided hypnotherapy. There…

LET’S be honest, it is what we think about the most: ourselves. What we want to eat or do, how we feel and whom we love. It is the essence of being. This selfhood generally feels like a continuous “me” sitting somewhere in our heads, a me that is the same today as yesterday. “Most people feel that they are a coherent, integrated individual. They have free will, they are making their choices and they’re looking out through their eyes at the world around them,” says Bruce Hood at the University of Bristol, UK, author of The Self Illusion. And that is just what selfhood seems to be – an illusion. “You are actually a collection of conflicting messages and signals and thought processes,” says Hood. “And these are somehow…

We tend to think of the brain as the puppet-master of the body. It is the control centre, firing off instructions and determining how we move, feel and think. Not so fast. Recent discoveries reveal the true, two-way nature of communication between the body and brain, with the body often calling the shots on the outputs from the mind. All this leads to a better understanding of who we really are, and how to harness the power of the body over the mind to improve everything from concentration to mental health.…

IF YOU had to point to the place where consciousness emerges, you would probably aim your finger squarely at your head. That is the easy bit. Exactly where the brain circuitry for consciousness lies, or how the physical properties therein seemingly transform into the subjective feeling of being, are questions that have bamboozled us for centuries. And it turns out that we might have been looking in the wrong place all along. ← Turn back to page 12 for more on consciousness The brain on its own isn’t enough to generate subjective experience, says Catherine Tallon-Baudry, a neuroscientist at the Ecole Normale Supérieure in Paris. Without the body, the self simply wouldn’t exist. “Just as the notion of ‘car’ exists only if a certain number of components are present and…

THE way we think about food can powerfully influence our satiety long after we have finished eating, and thanks to the mind-body connection, it can even shape our hormonal responses and the meal’s passage through the gut. As a result, our expectations around food can determine whether we will experience greater hunger pangs after we eat, and if we will find it harder to resist snacking later in the day. Astonishingly, this is all down to way that food is described, irrespective of the number of calories actually consumed. Fortunately, there are many ways to change our food mindsets, and they all centre on the idea that pleasure is an essential ingredient for any weight-loss regime. As paradoxical as it may seem, cultivating an indulgent attitude to food may be…

HOW’S your driving? If you are anything like the average person, you probably think it is pretty good. One study found that 74 per cent of drivers believed themselves to be better than average behind the wheel. And, perversely, those who had been in a crash were slightly more confident about their abilities than drivers who hadn’t been. This, of course, doesn’t reflect reality. Unless there are a handful of truly dreadful drivers, not everybody can be better than average. And yet if you ask people to rate themselves on almost any positive trait – competence, intelligence, honesty, originality, friendliness, reliability and many others – most put themselves in the better-than-average category. Ask them similar questions about negative traits and they will rate themselves as less likely than average to…

WHEN you are absorbed in a novel, what does your mind’s eye see? For many of us, it is a foggy, low-contrast approximation of the scenes described, no matter how evocatively they are written. Not so for Clare Dudeney. “When people describe things, especially gory things, I visualise them so vividly it’s like I’m experiencing them first-hand,” she says. “A few years ago, I was on the train reading a passage about someone who got a nail stuck in their foot and I passed out.” Dudeney is one of an unknown number of people with this ability, known as hyperphantasia. Mental imagery is inherently private, and it is hard enough to articulate what you see in your own mind’s eye, never mind get a sense of how it compares with…

What is parental burnout? Parental burnout is like any burnout. It’s an exhaustion disorder, but takes place in the parental domain. You are exhausted because of your parental role, even if you don’t have difficult or ill children. What are the symptoms? There are three main ones. The first is exhaustion, which is not a mere fatigue. It is more than fatigue. If you’re exhausted, and especially if you’re emotionally exhausted, it won’t disappear with a good night’s sleep. The second symptom is emotional distancing from your children. At some point, you keep the little energy you have left for yourself. The last symptom is the loss of pleasure and fulfilment in your parental role. Who is most likely to be affected? Parental burnout affects around 5 per cent of…

IN THE past few years, scientists have made a concerted effort to better understand not only what therapy does to the brain, but also who it helps and why. Psychotherapy is a catch-all term that describes the application of ideas from the field of psychology to treat mental or emotional problems. It draws on various schools of thought: some focus on the mind and brain, some on our relationships with others, and some on the connection between body and mind. But does it work? If you ask therapists working with people with mental health conditions, the answer is a resounding yes. The UK Council for Psychotherapy, a professional body representing UK-based therapists, points to combined analyses of hundreds of different studies. These meta-analyses show that psychotherapy is effective in both…

PEOPLE have known the importance of quietness for centuries: in many religions, silence is promoted as a vital healing process. The problem is, the world is getting louder, and according to the World Health Organization, our world is too noisy and this is harming our health. To counter this, a number of researchers have now turned their attention to the power of silence for the mind and how best to get that peace and quiet. One finding is that silence can help people more easily get into the kind of meditative state that can promote healing and well-being, and a flotation tank – a small, enclosed pod filled with salty water that blocks out all external noise – seems the perfect way to test the idea. Research has found that…