The Brain Is a Co-Conspirator in a Vicious Stress Loop

For the past difficult months you have been exposed to the bleeding edge of our negative economy.

Housing markets spontaneously combust, coworkers quickly disappear and the stifled, tortured moans of diminishing savings and pension plans can be heard through the walls and floorboards,

Now you have the awful sensation that your body’s stress response has taken on a self-replicating and ultimately self-defeating life of its own.

Well, Congratulations! for once you may have it right.

Stress Indicators
It's bad enough that chronic stress has been shown to raise blood pressure, stiffen arteries, suppress the immune system, heighten the risk of diabetes, depression and Alzheimer’s disease and make one a very unhappy and undesirable companion. Now researchers have discovered that the sensation of being highly stressed can drastically rewire the brain in ways that promote's a sinister persistence.

Repetitive Disorder
Reporting earlier this summer in the journal Science, Nuno Sousa of the Life and Health Sciences Research Institute at the University of Minho in Portugal and his colleagues described experiments in which chronically stressed rats lost their elastic rat cunning and instead fell back on familiar routines and rote responses, like compulsively pressing a bar for food pellets they had no intention of eating.

Pet Perturbations
Moreover, the rats’ behavioural perturbations were reflected by a pair of complementary changes in their underlying neural circuitry. On the one hand, regions of the brain associated with executive decision-making and goal-directed behaviours had shriveled, while, conversely, brain sectors linked to repeatative habit formation had bloomed.

Cognitively Predisposed
In other words, the rodents were now cognitively predisposed to keep doing the same things over and over, to run laps in the same dead-end rat race rather than seek a pipeline to greener paths or sewers. “Behaviours become very habitual and occur much quicker in stressed animals than in the controls, and what's worse, the stressed animals can’t shift back to goal-directed behaviours when that would be the better approach,” Dr. Sousa said. “It is a vicious circle.”

Rat In a Rut
Robert Sapolsky, a neurobiologist who studies stress at Stanford University School of Medicine, said, “This is a great model for understanding why stressed people end up in a rut, and then continue to dig themelves deeper and deeper into that rut.”

The truth is, Dr. Sapolsky said, “we’re lousy at recognising when our normal coping mechanisms aren’t working. Our response is usually to do it five times more, instead of thinking, maybe it’s time to try something new.”

Perversity
Perseverance and determination can be an admirable trait and is essential for all success in life, but when taken too far and at the wrong time, it becomes, uncontrollable repetition or simple perversity (?).

“If I were to try to break into the world of modern dance, after the first few rejections the logical response might be, get more practice first,” said Dr. Sapolsky, the author of “Why Zebras Don’t Get Ulcers,” among other books. “but after the 12,000th rejection, maybe I should realise this isn’t a viable career option.”

Reversible
Happily, the stress-induced changes in behaviour and brain appear to be reversible. To rattle the rats to the point where their stress response remained demonstrably hyperactive, the researchers exposed the animals to four weeks of varying degrees of stress: moderate electric shocks, being encaged with dominant rats, prolonged dunks in water.

Those animals who were chronically stressed were then compared with their non-stressed peers. The stressed rats had no trouble learning a task like pressing a bar to get a food pellet or a squirt of sugar water, but they had difficulty deciding when to stop pressing the bar, as normal rats easily did.

Restoration
Fortunately, after some R&R, four weeks’ vacation in a supportive setting, free of bullies and Tasers, the formerly stressed rats looked and behaved just like the controls; able to innovate, discriminate and would stop pressing the bar.

The atrophied synaptic connections in the decisive regions of the prefrontal cortex resprouted, while the overgrown dendritic vines of the habit-prone sensorimotor striatum retreated.

Resilient and Plastic
According to Bruce S. McEwen, head of the neuroendocrinology laboratory at Rockefeller University, the new findings offer a particularly elegant demonstration of a principle that researchers have just begun to grasp. “The brain is a very resilient and plastic organ,” he said. “Dendrites and synapses retract and reform, and reversible remodeling can occur throughout life.”

Neural and Endocrine
Stress may be most readily associated with the nano-second pace of postindustrial society, but the body’s stress response is one of our oldest possessions. Its basic architecture, its linked network of neural and endocrine organs that spit out stimulatory and inhibitory hormones and other factors as needed, looks pretty much the same in us as it does in a goldfish, rat or a frog.

Evading Predators
The stress response is essential for maneuvering through a dynamic world. For evading a predator or chasing down prey, swinging through the trees or fighting off disease. In fulfilling these functions, it is in itself very dynamic and succesful.

As we go about our lives, Dr. McEwen said, the biochemical mediators of the stress response rise and fall, flutter and flare. “Cortisol and adrenaline go up and down,” he said. “Our inflammatory cytokines go up and down.”

Natural Response
The target organs of stress hormones also dance to the same beat: blood pressure climbs and drops, the heart races and slows, the intestines constrict and relax. This system of so-called allostasis, of maintaining control through constant change, stands in contrast to the mechanisms of homeostasis that keep the pH level and oxygen concentration in the blood within a narrow and invariant range.

Balance Restoration
Unfortunately, the dynamism of our stress response makes it vulnerable to disruption, especially when the system is treated too roughly and not according to instructions. In most animals, a serious threat provokes a serious activation of the stimulatory, sympathetic, “fight or flight” side of the stress response but when the danger has passed, the calming parasympathetic circuitry calms everything back down to normal baseline flickering.

Thinking too much
Unfortunately, in humans, the brain thinks too much, extracting phantom threats from every staff meeting or high school dance, and over time the constant hyperactivation of the stress response can unbalance the entire feedback loop.

Health Hazards
Reactions that are desirable in limited, targeted quantities become hazard to your health in promiscuous excess. You need a spike in blood pressure if you’re going to run, to speedily deliver oxygen to your muscles but chronically elevated blood pressure is a source of multiple medical miseries.

Questions
Why should the stressed brain be prone to habit formation? This question remains unaswered but perhaps it is partly to help shunt as many behaviours as possible over to an automatic response mechanism or an 'auto pilot'. Separating the 'thinking' brain from the 'machine' and allowing both to do what they are best at.

The thinking half concentrates it's efforts on solving or dealing with the crisis, whilst the other half keeps the body functioning or simply just cycling a pre-determine routine.

Yet, unless they are 'dis-connected', repetitive habits can become entrenched, and as the novelist Ellen Glasgow observed, “The only difference between a rut and a grave are the dimensions.”

Enough is enough! Stop hitting the bar! It's time to break out of that self destructive cycle. Take the Time to relax, re-appraise your situation and remodel your stressed out brain. It's the only way forward from where you are. Also, you have a responsibility to look closely at your managers, colleagues and staff for signs of stress and the tell-tale signs of instinctive orprotective, repetative behaviours. If you find it, then try to help them break the viscious circle that their brain has created for them, too.

Type A and Type B personality theory

The Type A and Type B personality theory is a personality type theory that describes a pattern of behaviours that were once considered to be a risk factor for coronary heart disease.

Since its inception in the 1950s, the theory has been widely popularised and also widely criticised for its scientific shortcomings.

Type A individuals can be described as impatient, excessively time-conscious, insecure about their status, highly competitive, over-ambitious, business-like, hostile, aggressive, incapable of relaxation in taking the smallest issues too seriously; and are somewhat disliked for the way that they're always rushing and demanding other people to serve to their standards of satisfaction.

They are often high and over-achieving workaholics who multi-task, drive themselves with deadlines, and are unhappy about the smallest of delays. So, because of these characteristics, Type A individuals are often described as "stress junkies."

Type B Personality
Type B individuals, in contrast, are described as patient, relaxed, and easy-going. There is also a Type AB mixed profile for people who cannot be clearly categorised.

In his 1996 book, Type A Behaviour: Its Diagnosis and Treatment, Meyer Friedman suggests that Type A behaviour is expressed in three major symptoms. One of these symptoms is believed to be covert and therefore less observable, whereas the other two are more overt.

Symptoms of Type A Behaviour

1. An intrinsic insecurity or insufficient level of self-esteem, considered to be the root cause of the syndrome. This is believed to be covert and therefore less observable.
   
2. Time urgency and impatience, which causes irritation and exasperation.
3. Free floating hostility, which can be triggered by even minor incidents.

Criticism of this Theory
Type A/B theory has been criticised on a number of grounds. For example, statisticians have argued that the original study by Friedman and Rosenman had serious limitations, including large and unequal sample sizes, and less than 1% of the variance in relationship explained by Type A personality.

Psychometrically, the behaviours that define the syndrome are not highly correlated, indicating that this is a grouping of separate tendencies, not a coherent pattern or type. Type theories in general have been criticised as overly simplistic and incapable of assessing the degrees of difference in human personality.

Researchers have also found that Type A behaviour is not a good predictor of coronary heart disease. According to research by Redford Williams of Duke University, the hostility component of Type A personality is the only significant risk factor. Thus, it may be a high level of expressed anger and hostility, not the other elements of Type A behaviour, that constitute the problem.

Therefore, Type A theory is considered to be obsolete by many researchers in contemporary health psychology and personality psychology but, make up your own mind.

Living in a state of Déjà vu

Maybe you've heard this one before but believe me, you haven't. You only think you have.

Mr P, an 80-year-old Polish émigré and former engineer, knew he had memory problems, but it was his wife who described it as a permanent sense of déjà vu. He refused to watch TV or read a newspaper, as he claimed to have seen everything before. When he went out walking he said the same birds sang in the same trees and the same cars drove past at the same time every day. His doctor said he should see a memory specialist, but Mr P refused. He was convinced that he had already been.

Déjà vu can happen to anyone, and anyone who has had it will recognise the description immediately. It is more than just a sense that you have seen or done something before; it is a startling, inappropriate and often disturbing sense that history is repeating, and impossibly so. You can't place where the earlier encounter happened, and it can feel like a premonition or a dream. Subjective, strange and fleeting, not to mention tainted by paranormal explanations, the phenomenon has been a difficult and unpopular one to study.

Now that is changing, spurred in part by Mr P and a handful of people who, like him, have dementia and experience continuous déjà vu, and also by the discovery that there is a group of people with epilepsy who have déjà vu-like auras before a seizure. They are making it possible for researchers to catch the process in action, bringing hope that the secrets of this strange and disturbing phenomenon could finally be unlocked. Surprisingly, not only is déjà vu proving an interesting window on the peculiar ways that our memory works, it is also providing a few clues about how we tell the difference between what is real, imagined, dreamed and remembered - one of the true mysteries of consciousness.

Speculations about past lives or telepathy aside, the first biological explanations of déjà vu were based on ideas that two sensory signals in the brain - perhaps one from each eye or each hemisphere of the brain - for some reason move out of sync, so that people have the experience of reliving the same event. "Mental diplopia", as it was called, is intuitively appealing but the evidence is stacked against it. Information from the two eyes mixes very early in visual processing, long before we perceive a scene. What's more, déjà vu - rather ironically as the term means "already seen" - can occur in blind people, according to Chris Moulin, a psychologist at the University of Leeds, UK, (Brain and Cognition, vol 62, p 264). Then there are the cases of people who have had their two cortical hemispheres surgically separated in an attempt to relieve intractable epilepsy. If the mental diplopia idea were correct you might expect them to have permanent déjà vu, yet there are no reports of this happening.

A second intuitive explanation is some sort of distortion in time perception. Somehow, incoming signals must get misinterpreted and labelled with an inappropriate time stamp, making the experience seem old as well as current. If the brain's memory system is like a tape recorder, it is as if the recording head has got muddled with the playback head. It is an interesting analogy, but it does not appear to have any anatomical basis in the brain.

Now another theory is gaining credibility. Perhaps déjà vu feels like reliving a past experience because we actually are - at least to some extent. Psychologist Anne Cleary of Colorado State University in Fort Collins came to this idea via an interest in memory problems. Keen to explain instances such as when something seems to be on the tip of the tongue, or when we recognise a face but can't place it, she started looking for parallels with déjà vu. "One particular theory of déjà vu is that it may be a memory process," she says. "Features of a new situation may be familiar from some prior situation."

Her first experiments seem to support this. In one, she was able to induce familiarity for images of celebrity faces or well-known places, even if the viewer couldn't place the image, simply by first presenting subjects with lists of their names. In another study volunteers reported familiarity with words that sounded similar to ones presented in an earlier list. Nevertheless, Cleary acknowledges that this can't be the whole story. "Déjà vu is unique in that it is not just another instance of familiarity, it actually feels wrong," she says.

How to account for this? One possibility is that déjà vu is based on a memory fragment that comes from something more subtle, such as similarity between the configuration or layout of two scenes. Say you are in the living room of a friend's new house with the eerie feeling that you have been there before, yet knowing you can't possibly. It could be just that the arrangement of furniture is similar to what you have seen before, suggests Cleary, so the sense of familiarity feels misplaced.

To test the idea, her team produced a large range of images showing scenes such as a bar, a bowling alley, landscapes or rooms from a house. Volunteers saw a subset of these, then they were tested on a new set, half of which were entirely novel and the other half resembling scenes from the first set in structure and configuration but not content. Not only did the similar layouts produce familiarity without recall, subjects also reported a sense of the inexplicable, having been told that all the scenes were different.

Although the familiarity idea appeals to many, Moulin, for one, is not convinced. His scepticism stems from a study of a person with epilepsy that he conducted with Akira O'Connor, now at Washington University in St Louis, Missouri. This 39-year-old man's auras of déjà vu were long-lasting enough to conduct experiments during them. The researchers reasoned that if familiarity is at the root of déjà vu, they should be able to stop the experience in its tracks by distracting the man's attention away from whatever scene he was looking at. However, when he looked away or focused on something different, his déjà vu did not dissipate, and would follow his line of vision and his hearing, suggesting that real familiarity is not the key. The fact that an epilepsy aura can cause déjà vu at all suggests that it is erroneous activity in a particular part of the brain that leads to misplaced feelings of familiarity, suggests Moulin.

Hypnotic dissociation

But how? Moulin and O'Connor think déjà vu is the consequence of a dissociation between familiarity and recall. We know that we can have a sense of familiarity for a face or name without actually remembering where we know it from. Using hypnosis, O'Connor and Moulin have been able to create a more mysterious sense of familiarity that leads people to draw parallels with déjà vu. One group of people was given a puzzle to solve. Then, while under hypnosis, they were told they would be given the puzzle again, but would not recall it. Another group did not do the puzzle but were told under hypnosis that they would be given it later and that they would experience feelings of familiarity but not understand why. Both situations produced a sense of eerie familiarity, which some people likened to déjà vu. Moulin and O'Connor hope that their ability to induce a déjà vu-like state in the lab will help them probe the phenomenon. They also believe these experiments support the idea that familiarity and recall are dissociable, and that you can have a sense of familiarity without actually having any prior experience of something.

Studies of the brain also support the idea that separate circuits mediate recollection and familiarity, according to John Aggleton and Malcolm Brown of Cardiff University, UK, who recently reviewed brain imaging and animal studies (Trends in Cognitive Sciences, vol 10, p 455). They point out that different parts of the medial temporal lobe, at the side of the brain, are responsible for different aspects of memory recall (see illustration). The curved tube-like hippocampus, which runs through the centre of the lobe, mediates recollection, particularly of autobiographical memories. Meanwhile, the studies show that the surrounding parahippocampus, particularly the perirhinal cortex, may provide the feelings of familiarity.

This fits well with the evidence from brain scans of Mr P and others like him, who show huge degeneration of neurons in the medial temporal lobe, and the fact that it is epilepsy originating in the medial temporal lobe that leads to déjà vu auras.

It is possible that both Moulin and Cleary are correct. The perirhinal cortex may store information about spatial relationships, rather than time, place and sequence of events, and so normal familiarity feelings could come largely from layout and configuration, backing Cleary's findings. Indeed, there may be many ways to produce false familiarity, according to psychologist Alan Brown of Southern Methodist University in Dallas, Texas, author of The déjà vu experience (Psychology press, 2004). His own experiments indicate some other possibilities. For example, he has induced the feeling by distracting volunteers while they saw a glimpse of a scene and then moments later giving them a good look. "If you take a brief glance when distracted, and look at the same scene again afterwards, it can feel like you've seen it before but much earlier," says Brown. He has also induced it by showing people images of things they had forgotten. "Just as a stomach ache can hurt the same way but be caused by lots of different processes, it could be the same way with déjà vu," he says.

The real problem with explaining déjà vu, however, is not how we can get familiarity without recognition, but why it feels so disturbing. "We'd get it all the time if it were just familiarity with real experiences," says Ed Wild from the Institute of Neurology in London. He suggests that mood and emotion are also important contributors to the sensation of déjà vu. We need the right combination of signals, not just the layout of a scene but how we feel at the time, to believe something is familiar when really it is not.

A matter of degree

Moulin agrees it may be matter of degree. The regions thought to mediate recall, familiarity and emotions are all extremely closely linked. A small amount of stimulation could produce a mild sense of familiarity, while a stronger stimulus could spread into neighbouring emotion regions producing a more disturbing feeling, or even the striking sense of doom or premonition some people report with déjà vu.

Cognitive neuroscientist Stefan Köhler from the University of Western Ontario in London, Canada, believes the role of emotion is even more central in generating the sense of weirdness that accompanies déjà vu. He recently had the chance to image the brain of a person cured of epilepsy with déjà vu auras by removal of a large tumour that was triggering the seizures. The excised areas consisted of parts of the hippocampus and perirhinal cortex, but also included the amygdala. It suggests that this region, which is known to be heavily tied up with emotion, was also involved in creating the déjà vu. Köhler speculates that without the appropriate emotional arousal, perhaps the brain cannot recognise a person or place we have encountered before as truly familiar. On the other hand, inappropriate emotional arousal may make us believe something is familiar when actually it is not.

The final element of déjà vu, a sense that it feels impossible, probably comes from the reasoning parts of our brain. According to Köhler, when our rational knowledge tells us one thing, but our emotional instincts tell us another, it can feel very wrong. This final element is missing in people with dementia, including Mr P, who accept their experiences as perfectly normal. Köhler suspects this may be because neurodegeneration in these individuals has caused a disconnection between the temporal lobes, which are generating sensations, and the frontal lobes which are continuously interpreting them.

Our brains are looking for associations all the time. Déjà vu is interesting, says Kohler, because it points to a brain mechanism that helps you interpret what you are doing. When you are having a memory, you have the sensation of recollection. It feels like having a memory, and doesn't feel like daydreaming or current reality. "Déjà vu is a fault in a kind of cognitive process that is going on in the background all the time. When it goes wrong, it's very striking," says Moulin. At the extreme, patients with permanent déjà vu - dubbed déjà vecu, for already experienced - actually make up stories to make sense of it.

While déjà vu is starting to divulge some of its secrets, there is still a long way to go before we understand how we actually decide what is real, imagined, dreamed or experienced, and how these various tags lead to such different conscious experiences. One anecdotal finding that came to light while working on this article is that people who think a lot about déjà vu are more prone to it. I had déjà vu about reading about déjà vu, and researchers have had déjà vu about having déjà vu. It certainly retains mystery enough to justify further study. After all, says Wild, "déjà vu is one of weirdest brain experiences that normal people have".

Stranger becomes stranger yet

• About 10 per cent of people claim never to have experienced déjà vu, while some individuals report having it regularly.

• Children first get it at around age 8 or 9, suggesting that a degree of cognitive maturity is required.

• Déjà vu happens less as you get older and more when you are tired, anxious or stressed.

• It is particularly prevalent in people with certain conditions known to produce problems in time perception, such as schizophrenia and epilepsy.

• Although there is no gene for déjà vu, it is possible that certain versions of genes associated with epilepsy make some of us more prone to it.

• Just reading this article could give you déjà vu.

Article appeared in New Scientist on 25 March 2009 by Helen Phillips