Latest news with #neuroscientist
Yahoo
08-06-2025
- Health
- Yahoo
If anxiety is in my brain, why is my heart pounding? A psychiatrist explains the neuroscience and physiology of fear
Heart in your throat. Butterflies in your stomach. Bad gut feeling. These are all phrases many people use to describe fear and anxiety. You have likely felt anxiety inside your chest or stomach, and your brain usually doesn't hurt when you're scared. Many cultures tie cowardice and bravery more to the heart or the guts than to the brain. But science has traditionally seen the brain as the birthplace and processing site of fear and anxiety. Then why and how do you feel these emotions in other parts of your body? I am a psychiatrist and neuroscientist who researches and treats fear and anxiety. In my book 'Afraid,' I explain how fear works in the brain and the body and what too much anxiety does to the body. Research confirms that while emotions do originate in your brain, it's your body that carries out the orders. While your brain evolved to save you from a falling rock or speeding predator, the anxieties of modern life are often a lot more abstract. Fifty-thousand years ago, being rejected by your tribe could mean death, but not doing a great job on a public speech at school or at work doesn't have the same consequences. Your brain, however, might not know the difference. There are a few key areas of the brain that are heavily involved in processing fear. When you perceive something as dangerous, whether it's a gun pointed at you or a group of people looking unhappily at you, these sensory inputs are first relayed to the amygdala. This small, almond-shaped area of the brain located near your ears detects salience, or the emotional relevance of a situation and how to react to it. When you see something, it determines whether you should eat it, attack it, run away from it or have sex with it. Threat detection is a vital part of this process, and it has to be fast. Early humans did not have much time to think when a lion was lunging toward them. They had to act quickly. For this reason, the amygdala evolved to bypass brain areas involved in logical thinking and can directly engage physical responses. For example, seeing an angry face on a computer screen can immediately trigger a detectable response from the amygdala without the viewer even being aware of this reaction. The hippocampus is near and tightly connected to the amygdala. It's involved in memorizing what is safe and what is dangerous, especially in relation to the environment – it puts fear in context. For example, seeing an angry lion in the zoo and in the Sahara both trigger a fear response in the amygdala. But the hippocampus steps in and blocks this response when you're at the zoo because you aren't in danger. The prefrontal cortex, located above your eyes, is mostly involved in the cognitive and social aspects of fear processing. For example, you might be scared of a snake until you read a sign that the snake is nonpoisonous or the owner tells you it's their friendly pet. Although the prefrontal cortex is usually seen as the part of the brain that regulates emotions, it can also teach you fear based on your social environment. For example, you might feel neutral about a meeting with your boss but immediately feel nervous when a colleague tells you about rumors of layoffs. Many prejudices like racism are rooted in learning fear through tribalism. If your brain decides that a fear response is justified in a particular situation, it activates a cascade of neuronal and hormonal pathways to prepare you for immediate action. Some of the fight-or-flight response – like heightened attention and threat detection – takes place in the brain. But the body is where most of the action happens. Several pathways prepare different body systems for intense physical action. The motor cortex of the brain sends rapid signals to your muscles to prepare them for quick and forceful movements. These include muscles in the chest and stomach that help protect vital organs in those areas. That might contribute to a feeling of tightness in your chest and stomach in stressful conditions. The sympathetic nervous system is the gas pedal that speeds up the systems involved in fight or flight. Sympathetic neurons are spread throughout the body and are especially dense in places like the heart, lungs and intestines. These neurons trigger the adrenal gland to release hormones like adrenaline that travel through the blood to reach those organs and increase the rate at which they undergo the fear response. To assure sufficient blood supply to your muscles when they're in high demand, signals from the sympathetic nervous system increase the rate your heart beats and the force with which it contracts. You feel both increased heart rate and contraction force in your chest, which is why you may connect the feeling of intense emotions to your heart. In your lungs, signals from the sympathetic nervous system dilate airways and often increase your breathing rate and depth. Sometimes this results in a feeling of shortness of breath. As digestion is the last priority during a fight-or-flight situation, sympathetic activation slows down your gut and reduces blood flow to your stomach to save oxygen and nutrients for more vital organs like the heart and the brain. These changes to your gastrointestinal system can be perceived as the discomfort linked to fear and anxiety. All bodily sensations, including those visceral feelings from your chest and stomach, are relayed back to the brain through the pathways via the spinal cord. Your already anxious and highly alert brain then processes these signals at both conscious and unconscious levels. The insula is a part of the brain specifically involved in conscious awareness of your emotions, pain and bodily sensations. The prefrontal cortex also engages in self-awareness, especially by labeling and naming these physical sensations, like feeling tightness or pain in your stomach, and attributing cognitive value to them, like 'this is fine and will go away' or 'this is terrible and I am dying.' These physical sensations can sometimes create a loop of increasing anxiety as they make the brain feel more scared of the situation because of the turmoil it senses in the body. Although the feelings of fear and anxiety start in your brain, you also feel them in your body because your brain alters your bodily functions. Emotions take place in both your body and your brain, but you become aware of their existence with your brain. As the rapper Eminem recounted in his song 'Lose Yourself,' the reason his palms were sweaty, his knees weak and his arms heavy was because his brain was nervous. Leer en español. This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Arash Javanbakht, Wayne State University Read more: Pain and anxiety are linked to breathing in mouse brains – suggesting a potential target to prevent opioid overdose deaths Medication can help you make the most of therapy − a psychologist and neuroscientist explains how New research supports brain cell transplantation as a treatment for some neurological disorders Arash Javanbakht does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Telegraph
25-05-2025
- Health
- Telegraph
Brain scan to detect Alzheimer's before symptoms appear in world first
A world-first brain scanning technique could identify signs of Alzheimer's disease long before symptoms appear. The method, which analyses the cell structure of the brain, has been found to identify subtle changes in the cortical regions, including areas typically affected in the early stages of Alzheimer's disease. At the moment, diagnosis of diseases such as dementia normally relies on questionnaires which show memory problems combined with MRI scans, which can show loss of brain volume. However, this means many people are diagnosed only when the disease has progressed. The British scientists behind the 'precision diagnostic tool' said it could bring hope for millions of people with concerns about dementia. Tests suggest it is able to spot disruption in the structure and function of the cortex, particularly those associated with functions such as memory, decision-making and language. The new technique, called cortical disarray measurement, uses advanced software which analyses MRI scans to pinpoint more subtle signs of neurodegeneration. British company Oxford Brain Diagnostics has now been certified to start offering the method and is in talks with private health providers about rollout. It has already been designated by the US Food and Drug Administration for use in the United States as a 'breakthrough' device. The neuroscientist behind the advances said it meant medical professionals were able to see changes in the brain far earlier, at level normally only be possible via a post-mortem examination. Over the past year, two major treatments for Alzheimer's disease have been given the green light by UK regulators. Donanemab and lecanemab are the first treatments found to slow progression of the disease. However, both have been blocked for use on the NHS on the grounds they are not cost-effective. Experts believe that diagnosing dementia early is key to making treatments more effective and helping to ensure they become more widely available. Almost 1 million people in the UK are are living with dementia, but this number is expected to reach 1.4 million by 2040. Oxford Brain Diagnostics, a spinout company from the University of Oxford, was founded by Dr Steven Chance, former associate professor of neuroscience at Oxford, and Prof Mark Jenkinson, a leading expert in brain imaging. The breakthrough was achieved after the company received funding from UK investment firm BGF and the Oxford Technology & Innovations Fund. Identify other neurodegenerative conditions Studies have found the method can detect neurodegenerative changes before any visible brain shrinkage or atrophy appears on standard imaging as well as distinguish between different types of dementia. It has also been found to predict which individuals with mild cognitive impairment are more likely to develop dementia. The platform could also help to identify other neurodegenerative conditions including Parkinson's disease and multiple sclerosis. Dr Chance said: 'The core technology is founded on my background, looking at the microscopic structure of brains at autopsy for many years. You couldn't do that with a living patient and this is what we needed.' He said the technology could have a 'transformative' impact, bringing hope to 'millions of people who are seeking a non-invasive, precision diagnostic tool to reveal the truth about their brain health'. For now, the target patient market is those suffering mild cognitive decline, allowing professionals to differentiate between types of dementia and other neurodegenerative diseases. Dr Chance said clinics might offer annual MOTs for those with concerns about memory problems. In time, and with the advent of more medicines to treat dementia, such advances could be rolled out to those in mid-life, he said. 'More than 20 per cent of those over 50 have Alzheimer's-type changes, small-scale changes that would be otherwise invisible. These breakthroughs open up a whole new way of monitoring brain health.'
Fast Company
09-05-2025
- General
- Fast Company
It's easy to design safer streets. City planners just need to care
Psychologist: 'Design influences behavior.' Neuroscientist: 'Design influences behavior.' Uncivil engineer: 'It's not like my road design influences driver behavior.' Every day, preventable crashes are destroying lives because transportation planners and engineers don't understand that design influences behavior. (I'm being charitable by assuming they don't understand.) Drivers respond to the built environment much the same way water responds to a riverbed. The shape, width, and surface conditions of the riverbed determine the water's speed, turbulence, and direction. Likewise, the width of a road, presence of visual cues, curvature, intersections, and surrounding land use dictate how fast, aggressively, or cautiously people drive. The grocery store model If water sounds like too much of a stretch as a comparison, consider a grocery store. If you want to create public spaces that are intuitive and inviting, and encourage people to engage with their surroundings, then the best place to perfect these skills might be the grocery store. Retail giants understand and exploit the fact that design influences how people move through space. A grocery store is a real place where influencing behavior determines whether a business thrives or dies. Store layout is based on the art of persuasion. It's all about creating an environment that encourages customers to buy more products as easily as possible. Any parent knows this, but it's not just about candy at the cash register. Stores large and small invest time and money understanding human behavior, so they know which techniques work the best to influence buying habits. Expectations and habits Our brains are hardwired to react to buildings and spaces based on their visual characteristics. Tragically, those of us in the infrastructure business weren't taught about how psychology and neuroscience directly relate to everything we plan, design, and construct. Street design doesn't just influence behavior—it creates expectations and habits, often without conscious thought. For example: 1. Lane Width. Wide lanes signal to the brain: 'You're safe going fast.' Narrow lanes or painted-edge lanes create a sensation of compression, signaling: 'Stay alert, slow down.' Wider lanes increase speed, which multiplies injury severity rates exponentially when collisions occur. 2. Sight Lines and Curvature. Long, straight sight lines encourage higher speeds. The farther ahead a driver can see, the more they feel they can safely accelerate. Curved roads, particularly in urban contexts, force natural speed modulation because the driver's sight distance shrinks and perceived risk increases. 3. Street Trees and Vertical Elements. Streets with trees, light posts, benches, and buildings close to the curb create a 'street wall,' giving drivers the impression that the space is tight and shared. A bare, wide-open road without vertical edges feels boundless and invites acceleration. Researchers call this 'edge friction.' The more visual complexity and physical containment along the sides of a street, the slower and more carefully people drive. 4. Speed Limits vs. Speed Cues. Posted speed limits are barely noticed if street design suggests otherwise. A street engineered for 45 mph but posted at 25 mph will still see speeds closer to 45 unless strong visual and physical constraints are introduced. Design speed always wins over posted speed. 5. Lighting and Nighttime Design. Overly bright, highway-style lighting often promotes a false sense of security and encourages speeding. Moderate, pedestrian-scale lighting at consistent intervals supports slower, more cautious driving. Subconscious instructions The human brain processes the street as a series of subconscious instructions. The street is constantly whispering to drivers: 'Relax and go fast,' or 'Pay attention and slow down.' No amount of signage or enforcement will undo the basic psychological script written by engineers. Maybe transportation professionals should start their workday by looking at pictures of horrific crashes on streets that followed status quo design. At some point, someone on staff will have the courage to say, 'What if design influences behavior?'
