Archive for the ‘Stress’ Category

Why we should all be thanking our mothers

Sunday, June 3rd, 2012

One of the most powerful influences on our brains happens also to be one of the most powerful influences on our lives: other people. That ain’t no coincidence, folks – everything about us is related to our brains somehow. But it’s a fascinating area within neuroscience, because, believe it or not, scientists have just recently gotten around to documenting the way our connections with others influence the connections inside our heads.

The top academic journal Nature Neuroscience dedicated last month’s issue to “social neuroscience”, and there’s some cool stuff in there. One review paper talks about the various influences of social experience on our brain’s resiliency to stress. It’s been known for a long time that stressful experiences, especially early in life, cause the brain to develop in a way that makes it particularly vulnerable to stress, and also less cognitively efficient and able to learn. For example, it’s been found that abandoned children who were housed in those notoriously neglectful Romanian orphanages in the 1990s later had profound impairments in their cognitive ability, but – and this is the interesting part – the subsequent impairment was systematically less extensive, the earlier the children were taken into foster care. Other studies have shown that baby mice who are with their mothers have their stress/anxiety circuits kept in an immature state, but if they’re removed from their mothers, those circuits come online earlier in life.

Chronic stress prevents new neurons from forming and causes existing neurons to shrink in the cognitive parts of our brains (the hippocampus and prefrontal cortex, for you neuro-nerds), while in contrast the emotional parts of our brains (nerd alert: the amygdalae and the orbitofrontal cortex) grow and become more sensitive. Social stress (like loneliness, rejection, or conflict) is particularly powerful, and social contact is a powerful buffer against stress. One study showed that the brain’s stress response to impending electric shock was diminished significantly, just by having people hold their spouse’s hand!

It seems that cognitive ability, stress, and social contact are all intimately related to each other. So go out there and hug somebody; it might just make you smarter! And for heaven’s sake, call your mother and say thanks.

Stress, the autonomic nervous system, and Heart Rate Variability Biofeedback

Thursday, April 28th, 2011

Like I said, we’ve been busy around here. I recently produced the following document for an organization with whom we may be working. It serves as an introduction to Choratech’s method for training the nervous system to increase both physical and psychological resiliency to stress.

Heart Rate Variability Biofeedback: Training for Stress Resiliency and Improved Performance

Philip E. Toman, Ph.D.

Choratech

This document summarizes the scientific rationale and the clinical research supporting heart rate variability biofeedback (HRVB) as a means of enhancing the nervous system’s ability to respond effectively to stress, mitigating the negative impacts of stress on the body and the mind, and increasing performance in high-stress contexts.

Stress and the Nervous System

Stress is a situation of challenge and novelty that pushes the organism out of its equilibrium. Our brains and bodies were designed to handle this sort of challenge by mobilizing themselves for action. This is why stress brings about emotional and physiological changes that are activating in nature: under stress, our attention is directed and narrowed toward the source of danger or concern, we feel a sense of discomfort and urgency, we have difficulty with slower and more deliberative kinds of thinking, and our bodies are prepared for action through changes such as increased heart rate and blood pressure, shallower breathing, and the release of stress hormones.

All of these responses are accomplished through a system of close, two-way communication between the brain and the rest of the body, called the autonomic nervous system (ANS). The ANS has two branches, the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system mobilizes the stress response, while the parasympathetic nervous system acts as a “brake” on this response and works to return the organism to a resting state. These two branches are constantly active, dynamically opposing one another. They are also constantly modifying, and being modified by, the activity of the brain.

Our bodies’ response to stress, mediated by arousal of the sympathetic nervous system, was designed to be an effective way of dealing with short-term dangers or problems, such as getting our ancestors away from predators. In situations of immediate physical danger, the system works very well: the sympathetic nervous system helps get us out of trouble, and then the parasympathetic nervous system returns our bodies and brains back to their normal state soon afterward. But life in modern society is not the same as the life lived by our ancestors. It has few physical dangers, but many other stressors that are chronic and long-term in nature. Our worlds are fast-paced and complex, and contain many constant pressures such as workplace challenges, financial concerns, and the need to manage complicated networks of relationships with many different people.

Because the ANS was not designed to handle chronic stress, this kind of stress has negative impacts on the body, the brain, and the mind. Chronic stress increases our risk for chronic physical diseases such as immune system disorders, endocrine disorders, high blood pressure, and heart disease. It also affects the long-term functioning of our brains, reducing our ability to concentrate, interfering with our ability to sleep, and putting us at increased risk for conditions such as anxiety and depression.

The Heart-Brain Connection

Alongside the brain, one of the major centres of the autonomic nervous system is the heart. The heart is much more than a simple blood pump: it has its own “mini-brain” consisting of tens of thousands of neurons, it releases its own hormones, and it is extensively interconnected with the brain and the rest of the body.  Not only does the brain’s activity influence the heart, the heart’s activity also influences the brain.

In addition to being a major determinant of activity in the ANS, the heart is also a useful window into the state of the ANS. Recall that sympathetic arousal increases heart rate, while parasympathetic arousal decreases it. This means that changes in heart rate can be interpreted as representing changes in the state of the balance between the sympathetic and parasympathetic branches of the ANS.

The purpose of the ANS is to allow the individual to adapt flexibly to changing environmental conditions. It makes sense, then, that one of the best indices of the capacity of the ANS to modulate its activity is heart rate variability, or HRV. Rather than simply measuring how fast or slow the heart is beating, HRV measures how much the heart rate changes from one beat to the next. Higher variability (larger accelerations and decelerations in the heart rate) indicates a flexible, responsive ANS. In contrast, low HRV (the heart beating in a rigid, metronome-like pattern) is a sign of poor autonomic functioning.  Low HRV has been associated with many physical and emotional problems, including coronary artery disease, high blood pressure, depression, panic disorder, and posttraumatic stress disorder. High HRV is associated with good physical health, and it has also been found among individuals who have a generally positive outlook and the ability to manage and cope with emotional stresses effectively.

HRV Biofeedback

One of the fruits of our increased understanding of the relationship between the heart and the brain has been the development of HRV biofeedback (HRVB) as an intervention to increase the flexibility of the ANS, and thus to increase the resilience of the body and mind to stress. HRVB works by making patterns in the heart rate visible to the individual, allowing him or her to practise producing larger and larger changes in his or her heart rate. This is primarily accomplished through changing breathing patterns. When we breathe at a certain rate (about six breaths a minute), there is a physiological reflex mechanism in the ANS that results in a strong synchronization of our heart rate with our breathing: as we inhale, the heart accelerates, and as we exhale, it decelerates, producing a smooth, wave-like pattern of heart rate changes. In HRVB, the individual spends time every day practising making this wave pattern progressively larger and smoother.

The results of HRVB in published, scientific literature have been impressive. In numerous, independent studies it has had effects on both physical and psychological variables associated with stress and ANS functioning. HRVB has been shown to be effective in reducing the symptoms of several stress-related physical and psychological disorders, including hypertension (high blood pressure), asthma, fibromyalgia, depression, Posttraumatic Stress Disorder (PTSD), and Panic Disorder. In all these studies, participants have reported decreased self-perceived stress, increased ability to cope, reduced anxiety, and more positive mood.

Anecdotally, HRVB has also been noted to be a general performance enhancer. Because stress has a generally disruptive impact on brain performance, it stands to reason that enhancing the brain’s ability to manage stress will also increase its ability to do other things more effectively.

Choratech’s remotely coached HRV Biofeedback with the BioSign Qiu

Choratech has partnered with a world leader in HRVB technology, the German company BioSign GmbH.  BioSign has developed a number of tools for measuring HRV and doing HRV biofeedback. One of these is an elegant handheld device called the Qiu that makes HRVB possible anytime, anywhere. The user holds the Qiu in his or her hand, and blood volume sensors in the device pick up the heart rhythm. The Qiu device collects detailed, research-quality, heartbeat-by-heartbeat information from each practice session. When users synchronize their devices with software on their computers, they can email the data from their sessions to Choratech for analysis, allowing for personalized, remote coaching by Choratech staff. This helps to ensure that the practice is done on schedule, and that users benefit fully from use of the device.

Using the Qiu, Choratech is able to deliver an effective stress-resiliency intervention through remote means, with personalized coaching.

I’ve been doing HRV biofeedback for quite some time now myself, to get used to the technology. I can attest that it makes it much easier during my day to put on the parasympathetic “brake”, with effects that I can feel instantly both physically and emotionally. An additional benefit for me is that it has made me much more aware of how I am reacting to things physically, which in turn gives me cues as to what my emotions are telling me in the moment.

Recent study: New meaning given to concept of a “Bad Hair Day”

Wednesday, September 8th, 2010

Some researchers at an Israeli medical centre and the University of Western Ontario recently figured out that your hair can provide an indicator of your varying levels of stress across the span of several months. When we’re under stress we secrete higher levels of a hormone called cortisol. It’s used as a measure of stress levels in much scientific research, but until recently it was only measured from blood, urine, or saliva – which means it could only reflect current stress levels, not past stress levels. These researchers found that there is cortisol deposited in hair as it grows at its usual rate of one centimetre per month, and so a six-centimetre strand of hair holds about six months’ worth of stress data.

Here’s where it gets interesting: men who had had heart attacks were compared to other men who were visiting the hospital for other reasons, and their hair cortisol records showed significantly more cortisol than those of the other men across three months prior to their admission to hospital.

Take-home message? Stress is highly predictive of heart disease. This has actually been demonstrated repeatedly, in various ways. Depression is also a major predictor of heart disease, and probably for the same reasons. The exact mechanism for this relationship is not known, but it probably has something to do with the functioning of the autonomic nervous system, which is the dual-branch control system that connects the brain to the various other organs of the body, including the heart. Stress is related to dominance of one branch of this system over the other: the sympathetic nervous system (designed to mobilize the organism to deal with challenges and dangers) comes to predominate and the parasympathetic nervous system (associated with safety, calm, and relaxation) becomes outgunned. This is all pretty normal, but chronic stress can lead to a situation of prolonged and severe imbalance in the ANS–and some pretty bad health outcomes, not the least of which is heart disease.

Choratech is soon going to be introducing a product that helps to counteract stress by working to shift the balance within the autonomic nervous system in the parasympathetic direction. This technique, known as heart rate variability (HRV) biofeedback, has shown results in reducing things like anxiety, panic and depression, and serves as an effective general stress-buster. Interestingly, it also pushes cardiac variables in a more healthy direction, which strongly suggests that it will be an effective preventative measure against heart attack and other forms of heart disease. It involves training the communication pathways between the heart and the brain in such a way as to encourage parasympathetic activity, through providing information to the person moment-to-moment about his or her heart rate, and teaching him or her to increase the flexibility and range of the ANS activity, as reflected in the heart rate.

Curious? Contact us and I’ll go through it with you in detail.