Posts tagged anxiety
Posts tagged anxiety
Fear, at the right level, can increase alertness and protect against dangers. Disproportionate fear, on the other hand, can disrupt the sensory perception, be disabling, reduce happiness and therefore become a danger in itself. Anxiety disorders are therefore a psychiatric condition that should not be underestimated. In these disorders, the fear is so strong that there is tremendous psychological strain and living a normal life appears to be impossible. Researchers at the MedUni Vienna have now found a possible explanation as to how social phobias and fear can be triggered in the brain: a missing inhibitory connection or missing “brake” in the brain.
Inside the brain, the amygdala and the orbitofrontal cortex in the frontal lobe form an important control circuit for regulating the emotions. This control circuit is termed the brain’s emotional control centre. Whereas in healthy subjects, this circuit has “negative feedback” and “calmness” was identified, scientists used functional magnetic resonance imaging (MRI) on people with social phobias and found the opposite to be true: an important inhibitory connection is different in these patients, which may explain why they are unable to control their fears.
In collaboration with the Centre for Medical Physics and Biomedical Technology and the University Department of Psychiatry and Psychotherapy at the MedUni Vienna, the research team lead by Christian Windischberger was also able to discover through its recent study at the MedUni Vienna’s High Field MR Centre of Excellence how the areas of the brain that are involved with processing emotions are able to influence each other.
The study participants were shown a series of “emotional faces” while undergoing functional magnetic resonance imaging. fMRI is a non-invasive method which uses radio waves and magnetic fields to measure changes in the levels of oxygen in the blood and therefore neuronal activity in individual regions of the brain. An analysis method developed at University College London was used to provide new perspectives on the data obtained.
Breaking the circle of fear
When emotional facial expressions were shown - from laughing to crying, from happiness to anger - neuronal activity was triggered in the brain. The result: on a purely external basis, the test subjects looked no different, but the healthy subjects were kept calm thanks to their automatic “brake”, despite the emotional nature of the images. For the social phobics, on the other hand, the photographs put their brains into “overdrive”, triggering very strong neuronal activity. This was demonstrated very clearly using the new analysis method: “We have the opportunity not only to localise brain activity and compare it between groups, but we can now also make statements regarding functional connections within the brain. In psychiatric conditions especially, we can assume that there are not complete failures of these connections going on, but rather imbalances in complex regulatory processes,” says Ronald Sladky, the study’s primary author.
This better understanding of the neuronal mechanisms involved will now be used to develop new approaches to treatment. The aim is to understand what effect medications and psycho-therapeutic support have on the networks involved in order to help patients break out of their circles of fear.
While traditional horror video games seek to provide an exciting thrill, Nevermind is a biofeedback-enhanced horror game that has greater ambitions. It requires you to manage your anxiety in alarming scenarios – the more stressed you feel, the harder the game becomes. The aim, says Erin Reynolds, its creator, is for players to learn how to not let their fears get the best of them in nerve-wracking situations and hopefully carry over their gameplay-acquired skills into the real world.
A Garmin cardio chest strap akin to the ones gym-goers use to monitor their workout acts as a sensor, relaying the player’s heart rate information to the game through an ANT+ USB stick. The game calculates the player’s Heart Rate Variability (HRV), measuring the change in the duration between their heartbeats to figure out when their “fight or flight” response has kicked in and adjusts the gameplay accordingly. While Nevermind can’t zero in on specific stressful emotions like frustration or upset, it’s able to detect the intensity of the player’s feelings and gauge how deeply they feel stress at any point during the game.
Instead of having fanged horrors and hordes of zombies jump out from around corners, which might need a learning curve, the game is more subtle in inducing fear and is designed to appeal to non-gamers too. It creates a warped chaotic atmosphere where the creepiness factor is slowly dialed up, with huge screaming heads, blood-spattered doors and thrashing body bags.
Assuming the role of a newly hired Neruroprober at the Neurostalgia Institute, players boldly dive into the troubled minds of traumatized patients who are repressing their most horrific memories. To root out the cause of their suffering, players will need to solve puzzles and be willing to face a host of unimaginable terrors before the patient’s subconscious is ready to release its painful memories.
"This psychological phenomenon is based on how some people cope with severe psychological trauma in real life," Reynolds tells Gizmag. "These are individuals who experienced an event so terrible at some point in their lives that their conscious minds locked all memories of that event away completely. Although the patients can’t recall exactly what, if anything, happened to them, the repressed memories end up festering within their subconscious and create immense challenges in their attempts to live a normal life."
The sensor detects how scared or stressed the player gets as they move through the patient’s subconscious, recovering ten Polaroid photographs that each represent a distressful memory. Once all the photographs have been collected, they’ll have to differentiate the false memories from the five true ones and reconstruct the traumatizing memory. If they start to feel more fear, which the game sets out to trigger, the gameplay becomes perceptibly difficult. While some situations impact players more than others, they are all designed to push the player’s buttons.
For example, in the “car maze” section players follow the guiding sound of a blaring car horn through a twisting cave-like maze of crashed and wrecked cars full of disorienting imagery. As the player’s fear levels rise, the visuals become increasingly distorted until they are barely able to see what’s ahead of them.
"Some players become anxious over the car horn, others over the complexity of the maze, some over the imagery – there are a whole host things in this area that can rile up one’s nerves," says Reynolds. "The player needs to have a good grasp on how to calm down by this point in the game as it’s a nearly impossible challenge to escape the maze while scared or stressed."
In another scenario, the player explores a grotesque kitchen to find an ambiguous writhing mass in an oven and a giant bloodied refrigerator buzzing with flies that offers a puzzle. If the player gets rattled trying to solve the puzzle in this disturbing setting, milk starts flooding the room, pouring in from all over. Sloshing around in the waist-high milk makes it harder to move and the more anxious the player feels, the more milk floods in until it drowns them. If they are able to calm down in time the milk stops pouring in and drains out. If not, they drown and the game pulls them out of the room, returning them to the peaceful surroundings of the Institute until they feel ready again.
Making the game tougher as the player’s fear increases might seem counter-intuitive, but its developers were very clear about designing it that way. “We wanted players to become aware in a very real way of when their anxiety levels were starting to become elevated and reward them for being able to manage that anxiety on the fly,” Reynolds tells us. “We knew making the environment change so significantly that it would impact what the player was doing would get their attention.”
Developed as part of a Master of Fine Arts (MFA) thesis project within the University of Southern California’s Interactive Media and Games Division, Nevermind took about a year to build and presently exists as a “proof of concept game.” It has one level with one patient’s subconscious mind connected to a hub area that’s built to support the minds of 10 more patients. A play through takes about an hour. Reynolds plans to get a Kickstarter project going and launch the game with a variety of disturbed patients in late 2014. The team also plans to conduct thorough studies of the game’s impact on players and explore its use in therapy.
Will playing the game have us reacting to freaky situations with a Yoda-like serene gaze? Its developers hope it will help.
“Nevermind draws players in with the promise of a fun, exciting horror game that uses some spiffy new technology, but I hope it ultimately leaves them better equipped to take on the world more bravely and confidently than ever before,” Reynolds tells us. “In a way, it’s the biggest puzzle in the game – how do you solve your gut, knee-jerk reactions to unpleasant scenarios? If you can figure it out in the game, you’ll find success. If you can figure it out in life, you’ll find success there too.”
A research team at Worcester Polytechnic Institute (WPI) and The Rockefeller University in New York has developed a novel system to image brain activity in multiple awake and unconstrained worms. The technology, which makes it possible to study the genetics and neural circuitry associated with animal behavior, can also be used as a high-throughput screening tool for drug development targeting autism, anxiety, depression, schizophrenia, and other brain disorders.
Image: Neurons in the worms (marked by arrows) glow as the animals sense attractive odors.
The team details their technology and early results in the paper “High-throughput imaging of neuronal activity in Caenorhabditis elegans,” published on-line in advance of print by the journal Proceedings of the National Academy of Sciences.
"One of our major objectives is to understand the neural signals that direct behavior—how sensory information is processed through a network of neurons leading to specific decisions and responses," said Dirk Albrecht, PhD, assistant professor of biomedical engineering at WPI and senior author of the paper. Albrecht led the research team both at WPI and at Rockefeller, where he served previously as a postdoctoral researcher in the lab of Cori Bargmann, PhD, a Howard Hughes Medical Institute Investigator and a co-author of the new paper.
To study neuronal activity, Albrecht’s lab uses the tiny worm Caenorhabditis elegans (C. elegans), a nematode found in many environments around the world. A typical adult C. elegans is just 1 millimeter long and has 969 cells, of which 302 are neurons. Despite its small size, the worm is a complex organism able to do all of the things animals must do to survive. It can move, eat, mate, and process environmental cues that help it forage for food or react to threats. As a bonus for researchers, C.elegans is transparent. By using various imaging technologies, including optical microscopes, one can literally see into the worm and watch physiological processes in real time.
Numerous studies have been done by “worm labs” around the world exploring various neurological processes in C. elegans. These have typically been done using one worm at a time, with the animal’s body fixed in place on a slide. In their new paper, Albrecht’s team details how they imaged, recorded, and analyzed specific neurons in multiple animals as they wormed their way around a custom-designed microfluidic array, called an arena, where they were exposed to favorable or hostile sensory cues.
Specifically, the team engineered a strain of worms with neurons near the head that would glow when they sensed food odors. In experiments involving up to 23 worms at a time, Albrecht’s team infused pulses of attractive or repulsive odors into the arena and watched how the worms reacted. In general, the worms moved towards the positive odors and away from the negative odors, but the behaviors did not always follow this pattern. “We were able to show that the sensory neurons responded to the odors similarly in all the animals, but their behavioral responses differed significantly,” Albrecht said. “These animals are genetically identical, and they were raised together in the same environment, so where do their different choices come from?”
In addition to watching the head neurons light up as they picked up odor cues, the new system can trace signaling through “interneurons.” These are pathways that connect external sensors to the rest of the network (the “worm brain”) and send signals to muscle cells that adjust the worm’s movement based on the cues. Numerous brain disorders in people are believed to arise when neural networks malfunction. In some cases the malfunction is dramatic overreaction to a routine stimulus, while in others it is a lack of appropriate reactions to important cues. Since C. elegans and humans share many of the same genes, discovering genetic causes for differing neuronal responses in worms could be applicable to human physiology. Experimental compounds designed to modulate the action of nerve cells and neuronal networks could be tested first on worms using Albrecht’s new system. The compounds would be infused in the worm arena, along with other stimuli, and the reaction of the worms’ nervous systems could be imaged and analyzed.
"The basis of our work is to combine biomedical engineering and neuroscience to answer some of these fundamental questions and hopefully gain insight that would be beneficial for understanding and eventually treating human disorders," Albrecht said.
Research released today reveals new mechanisms and areas of the brain associated with anxiety and depression, presenting possible targets to understand and treat these debilitating mental illnesses. The findings were presented at Neuroscience 2013, the annual meeting of the Society for Neuroscience and the world’s largest source of emerging news about brain science and health.
More than 350 million people worldwide suffer from clinical depression and between 5 and 25 percent of adults suffer from generalized anxiety, according to the World Health Organization. The resulting emotional and financial costs to people, families, and society are significant. Further, antidepressants are not always effective and often cause severe side effects.
Today’s new findings show that:
Other recent findings discussed show that:
“Today’s findings represent our rapidly growing understanding of the individual molecules and brain circuits that may contribute to depression and anxiety,” said press conference moderator Lisa Monteggia, PhD, of the University of Texas Southwestern Medical Center, an expert on mechanisms of antidepressant action. “These exciting discoveries represent the potential for significant changes in how we diagnose and treat these illnesses that touch millions.”
Research by the University of Liverpool has found that people experiencing depressive episodes display increased brain activity when they think about themselves.
Using functional magnetic resonance imaging (fMRI) brain imaging technologies, scientists found that people experiencing a depressive episode process information about themselves in the brain differently to people who are not depressed.
Researchers scanned the brains of people in major depressive episodes and those that weren’t whilst they chose positive, negative and neutral adjectives to describe either themselves or the British Queen - a figure significantly removed from their daily lives but one that all participants were familiar with.
Professor Peter Kinderman, Head of the University’s Institute of Psychology, Health and Society, said: “We found that participants who were experiencing depressed mood chose significantly fewer positive words and more negative and neutral words to describe themselves, in comparison to participants who were not depressed.
“That’s not too surprising, but the brain scans also revealed significantly greater blood oxygen levels in the medial superior frontal cortex – the area associated with processing self-related information – when the depressed participants were making judgments about themselves.
“This research leads the way for further studies into the psychological and neural processes that accompany depressed mood. Understanding more about how people evaluate themselves when they are depressed, and how neural processes are involved could lead to improved understanding and care.”
Dr May Sarsam, from the Mersey Care NHS Trust, said: “This study explored the difference in medical and psychological theories of depression. It showed that brain activity only differed when depressed people thought about themselves, not when they thought about the Queen or when they made other types of judgements, which fits very well with the current psychological theory.
“Thought and neurochemistry should be considered as equally important in our understanding of mental health difficulties such as depression.”
Depression is associated with extensive negative feelings and thoughts. Nearly one-fifth of adults experience anxiety or depression, with the conditions affecting a higher proportion of women than men.
Excessive fear can develop after a traumatic experience, leading to anxiety disorders such as post-traumatic stress disorder and phobias. During exposure therapy, an effective and common treatment for anxiety disorders, the patient confronts a fear or memory of a traumatic event in a safe environment, which leads to a gradual loss of fear. A new study in mice, published online today in Neuron, reports that exposure therapy remodels an inhibitory junction in the amygdala, a brain region important for fear in mice and humans. The findings improve our understanding of how exposure therapy suppresses fear responses and may aid in developing more effective treatments. The study, led by researchers at Tufts University School of Medicine and the Sackler School of Graduate Biomedical Sciences at Tufts, was partially funded by a New Innovator Award from the Office of the Director at the National Institutes of Health.
A fear-inducing situation activates a small group of neurons in the amygdala. Exposure therapy silences these fear neurons, causing them to be less active. As a result of this reduced activity, fear responses are alleviated. The research team sought to understand how exactly exposure therapy silences fear neurons.
The researchers found that exposure therapy not only silences fear neurons but also induces remodeling of a specific type of inhibitory junction, called the perisomatic synapse. Perisomatic inhibitory synapses are connections between neurons that enable one group of neurons to silence another group of neurons. Exposure therapy increases the number of perisomatic inhibitory synapses around fear neurons in the amygdala. This increase provides an explanation for how exposure therapy silences fear neurons.
“The increase in number of perisomatic inhibitory synapses is a form of remodeling in the brain. Interestingly, this form of remodeling does not seem to erase the memory of the fear-inducing event, but suppresses it,” said senior author, Leon Reijmers, Ph.D., assistant professor of neuroscience at Tufts University School of Medicine and member of the neuroscience program faculty at the Sackler School of Graduate Biomedical Sciences at Tufts.
Reijmers and his team discovered the increase in perisomatic inhibitory synapses by imaging neurons activated by fear in genetically manipulated mice. Connections in the human brain responsible for suppressing fear and storing fear memories are similar to those found in the mouse brain, making the mouse an appropriate model organism for studying fear circuits.
Mice were placed in a box and experienced a fear-inducing situation to create a fear response to the box. One group of mice, the control group, did not receive exposure therapy. Another group of mice, the comparison group, received exposure therapy to alleviate the fear response. For exposure therapy, the comparison group was repeatedly placed in the box without experiencing the fear-inducing situation, which led to a decreased fear response in these mice. This is also referred to as fear extinction.
The researchers found that mice subjected to exposure therapy had more perisomatic inhibitory synapses in the amygdala than mice who did not receive exposure therapy. Interestingly, this increase was found around fear neurons that became silent after exposure therapy.
“We showed that the remodeling of perisomatic inhibitory synapses is closely linked to the activity state of fear neurons. Our findings shed new light on the precise location where mechanisms of fear regulation might act. We hope that this will lead to new drug targets for improving exposure therapy,” said first author, Stéphanie Trouche, Ph.D., a former postdoctoral fellow in Reijmers’ lab at Tufts and now a medical research council investigator scientist at the University of Oxford in the United Kingdom.
“Exposure therapy in humans does not work for every patient, and in patients that do respond to the treatment, it rarely leads to a complete and permanent suppression of fear. For this reason, there is a need for treatments that can make exposure therapy more effective,” Reijmers added.
Early life pain alters neural circuits in the brain that regulate stress, suggesting pain experienced by infants who often do not receive analgesics while undergoing tests and treatment in neonatal intensive care may permanently alter future responses to anxiety, stress and pain in adulthood, a research team led by Dr. Anne Murphy, associate director of the Neuroscience Institute at Georgia State University, has discovered.
An estimated 12 percent of live births in the U.S. are considered premature, researchers said. These infants often spend an average of 25 days in neonatal intensive care, where they endure 10-to-18 painful and inflammatory procedures each day, including insertion of feeding tubes and intravenous lines, intubation and repeated heel lance. Despite evidence that pain and stress circuitry in the brain are established and functional in preterm infants, about 65 percent of these procedures are performed without benefit of analgesia. Some clinical studies suggest early life pain has an immediate and long-term impact on responses to stress- and anxiety-provoking events.
The Georgia State study examined whether a single painful inflammatory procedure performed on male and female rat pups on the day of birth alters specific brain receptors that affect behavioral sensitivity to stress, anxiety and pain in adulthood. The findings demonstrated that such an experience is associated with site-specific changes in the brain that regulate how the pups responded to stressful situations. Alterations in how these receptors function have also been associated with mood disorders.
The study findings mirror what is now being reported clinically. Children who experienced unresolved pain following birth show reduced responsiveness to pain and stress.
“While a dampened response to painful and stressful situations may seem advantageous at first, the ability to respond appropriately to a potentially harmful stimulus is necessary in the long term,” Dr. Murphy said.
“The fact that less than 35 percent of infants undergoing painful and invasive procedures receive any sort of pre- or post-operative pain relief needs to be re-evaluated in order to reduce physical and mental health complications associated with preterm birth.”
Scientists increasingly are uncovering answers for human behavior through genetic research. Now, a University of Missouri researcher has found that prosocial behavior, such as volunteering and helping others, is related to the same gene that predisposes individuals to anxiety disorders. Helping such individuals cope with their anxiety may increase their prosocial behavior, the researcher said.
“Prosocial behavior is linked closely to strong social skills and is considered a marker of individuals’ health and well-being,” said Gustavo Carlo, Millsap Professor of Diversity in MU’s College of Human Environmental Sciences. “Social people are more likely to be healthier, excel academically, experience career success and develop deeper interpersonal relationships that may help alleviate stress.”
Carlo and his colleagues found that, on average, those individuals who carried the genotype associated with higher social anxiety were less likely to engage in prosocial behavior.
“Previous research has shown that the brain’s serotonin neurotransmitter system plays an important role in regulating emotions,” said study co-author Scott Stoltenberg, an associate professor at the University of Nebraska-Lincoln. “Our findings suggest that individual differences in social anxiety levels are influenced by this serotonin system gene and that these differences help to partially explain why some people are more likely than others to behave prosocially. Studies like this one show that biological factors are critical influences on how people interact with one another.”
Because prosocial behavior is linked to genetically based anxiety, Carlo suggests that helping nervous individuals cope with their social anxiety through targeted efforts, such as encouragement, support, counseling and medication, could help them engage in more prosocial behavior.
“Some forms of anxieties can be very debilitating for individuals,” Carlo said. “When people have severe levels of social anxiety, such as agoraphobia, which is the fear of public places and large crowds, they will avoid social situations altogether and miss the prosocial opportunities.”
Carlo said that it is difficult to distinguish how much of prosocial behavior is based on learned environmental behavior and how much is biologically based.
“The nature-versus-nurture debate is always interesting,” Carlo said. “However, I think that in our contemporary models of human behavior, we are beginning to understand the interplay between biology and the environment.”
Much of Carlo’s previous study on prosocial development has focused on how environmental influences, such as family relationships, influence prosocial behavior. This study brings researchers closer to understanding the effect that individuals’ biological makeup has on their behaviors, Carlo said.
In evolutionary terms, smell is among the oldest of the senses. In animals ranging from invertebrates to humans, olfaction exerts a primal influence as the brain continuously and subconsciously processes the steady stream of scent molecules that waft under our noses.
And while odors — whether the aroma of stinky socks or the sweet smell of baking bread — are known to stir the emotions, how they exert their influence biologically on the emotional centers of the human brain, evoking passion or disgust, has been a black box.
Now, however, researchers using powerful new brain imaging technologies are peeling back some of the mystery, revealing how anxiety or stress can rewire the brain, linking centers of emotion and olfactory processing, to make typically benign smells malodorous.
Writing today (Sept. 24, 2013) in the Journal of Neuroscience, a team led by Wen Li, a professor of psychology at the UW-Madison Waisman Center, reports that the brains of human subjects experience anxiety induced by disturbing pictures and text of things like car crashes and war transform neutral odors to distasteful ones, fueling a feedback loop that could heighten distress and lead to clinical issues like anxiety and depression.
The finding is important because it may help scientists understand the dynamic nature of smell perception and the biology of anxiety as the brain rewires itself under stressful circumstances and reinforces negative sensations and feelings.
"After anxiety induction, neutral smells become clearly negative," explains Li, who conducted the study with UW-Madison colleagues Elizabeth Krusemark and Lucas Novak, and Darren Gitelman of Northwestern University’s Feinberg School of Medicine. "People experiencing an increase in anxiety show a decrease in the perceived pleasantness of odors. It becomes more negative as anxiety increases."
Using behavioral techniques and functional magnetic resonance imaging (fMRI), Li’s group looked at the brains of a dozen human subjects with induced anxiety as they processed known neutral odors.
Functional MRI is a technology that enables clinicians and researchers to observe the working brain in action. Before entering the MRI where screens cycle through a series of disturbing pictures and text, subjects were exposed to and rated a panel of neutral smells.
In the course of the experiment, the Wisconsin team observed that two distinct and typically independent circuits of the brain — one dedicated to olfactory processing, the other to emotion — become intimately intertwined under conditions of anxiety. Subsequent to anxiety induction and the imaging process, subjects were asked again to rate the panel of neutral smells, most assigning negative responses to smells they previously rated as neutral.
"In typical odor processing, it is usually just the olfactory system that gets activated," says Li. "But when a person becomes anxious, the emotional system becomes part of the olfactory processing stream."
Although those two systems of the brain are right next to each other, under normal circumstances there is limited crosstalk between the two. However, under conditions of induced anxiety, the Wisconsin team observed the emergence of a unified network cutting across the two systems.
The results may have clinical implications in the sense that it begins to uncover the biological mechanisms at play during periods of anxiety. “We encounter anxiety and as a result we experience the world more negatively. The environment smells bad in the context of anxiety. It can become a vicious cycle, making one more susceptible to a clinical state of anxiety as the effects accumulate. It can potentially lead to a higher level of emotional disturbances with rising ambient sensory stress.”
The space surrounding the body (known by scientists as ‘peripersonal space’), which has previously been thought of as having a gradual boundary, has been given physical limits by new research into the relationship between anxiety and personal space.
New findings have allowed scientists to define the limit of the ‘peripersonal space’ surrounding the face as 20-40cm away. The study is published today in The Journal of Neuroscience.
As well as having numerical limits the specific distance was found to vary between individuals. Those with anxiety traits were found to have larger peripersonal space.
In an experiment, Dr Chiara Sambo and Dr Giandomenico Iannetti from UCL recorded the blink reflex - a defensive response to potentially dangerous stimuli at varying distances from subject’s face. They then compared the reflex data to the results of an anxiety test where subjects rated their levels of anxiety in various situations.
Those who scored highly on the anxiety test tended to react more strongly to stimuli 20cm from their face than subjects who got low scores on the anxiety test. Researchers classified those who reacted more strongly to further away stimuli as having a large ‘defensive peripersonal space’ (DPPS).
A larger DPPS means that those with high anxiety scores perceive threats as closer than non-anxious individuals when the stimulus is the same distance away. The research has led scientists to think that the brain controls the strength of defensive reflexes even though it cannot initiate them.
Dr Giandomenico Iannetti (UCL Neuroscience, Physiology and Pharmacology), lead author of the study, said: “This finding is the first objective measure of the size of the area surrounding the face that each individual considers at high-risk, and thus wants to protect through the most effective defensive motor responses.”
In the experiment, a group of 15 people aged 20 to 37 were chosen for study. Researchers applied an intense electrical stimulus to a specific nerve in the hand which causes the subject to blink. This is called the hand-blink reflex (HBR) which is not under conscious control of the brain.
This reflex was monitored with the subject holding their own hand at 4, 20, 40 and 60 cm away from the face. The magnitude of the reflex was used to determine how dangerous each stimulus was considered, and a larger response for stimuli further from the body indicated a larger DPPS.
Subjects also completed an anxiety test in which they self-scored their predicted level of anxiety in different situations. The results of this test were used to classify individuals as more or less anxious, and were compared to the data from the reflex experiment to determine if there was a link between the two tests.
Scientists hope that the findings can be used as a test to link defensive behaviours to levels of anxiety. This could be particularly useful determining risk assessment ability in those with jobs that encounter dangerous situations such as fire, police and military officers.