Stress consequences and biofeedback
Stress consequences can be severe. However, stress can be difficult to define precisely which is a significant complication. Also stress isn't about just the "head or the heart" - it is a whole body event. Just think for a moment - In practical terms, we can imagine that if we paid as much attention to the thoughts we allow in our minds, as to the food we place in our mouths we would be more productive, healthier and an awful lot happier.
Emotional stress can have a major impact on cardiovascular function and this is an effect that originates in the forebrain (including the insular, infralimbic cortices and amygdala. Research has identified the organisation and function of the autonomic control system of the forebrain - the regions in the brain that control these effects.
Autonomic control takes place via a complex series of reflex loops involving progressively higher regions of the brain. Visceral inputs that include those from cardiovascular, gastrointestinal, respiratory and gustatory afferent neurons are all involved. The interested reader can delve into the details in the article by Cechetto referenced below. We will take a shallower path through some of the details.
When we actively feel something, it is truly engaging our whole physiology not just our imagination. Science tells us that every single cell in our body is influenced by our feelings through our nervous system and the flow of our “molecules of emotion”.
Candice Pert came up with this elegant term to describe the hormones within our body that act as a chemical nervous system having the power to make us well or ill. Hundreds of hormones flow because of our emotions and we manifest the consequence of those feelings. Sad feelings actually produce sad bodies. Depressed feelings produce depressed and ageing bodies and happy feelings produce healthier and youthful bodies. This is important because it implies what science confirms. Our feelings and emotions are actually a factor in the development of cancers, heart attacks and many other damaging events. When people talk about the undesirable aspects of stress this is, in essence, what they are talking about.
In case you weren't sure, there is extensive evidence that stress is bad for us. Both clinical and experimental evidence accumulated over many years implicate stress, anger and anxiety in the development of atherosclerosis, myocardial ischemia and infaction, hypertension, cardiac arrhythmia generation and - wait for it - sudden death.
Physicians even in ancient times new about the effects of stress on cardiovascular status. Arabian physician Avicenna used wolves to create mental stress in lambs thereby causing their death. There have been numerous studies that have demonstrated the relationship between acute mental stress and cardiovascular disturbances.
We can induce stress in the lab through the use of tasks such as the Stroop test, mental arithmetic or even simulated public speaking (a significant stressor for many people). (We can induce stress easily without the use of wolves). Using such techniques researchers have shown significant impact upon blood pressure and heart rate for example.
Some results demonstrate a link between so-called Type A personalities and clinical cardiovascular disturbances. Other studies don't find this link between personality and cardiovascular effects. This points to the fact that there is no universal standard for what constitutes an "amount" of stress. We all perceive and respond to stressful events in a very personal way.
People seek emotional balance and release from stress by any number of methods. For example, by getting away from the stressful environment, by meditation, yoga, walking on the beach and so on. But what about when it's not so easy to detatch and remove yourself from that situation and stress becomes chronic? This is where biofeedback methods can help.
In fact, a large percentage of people with chronic stress do not profit very much from relaxation exercises. Sometimes relaxation exercises are given without really knowing what is going on in the body of the person. So sometimes a person with a normal breathing pattern gets the advice to do daily breathing exercises and conversely a person with a disturbed breathing pattern is advised to try progressive relaxation of the muscles.
Wouldn't it be better for stress related complaints if the therapist and client are able to see clearly how the body reacts during relaxation and during stress?
That is what psychophysiological stress profiling is about.
By measuring simultaneously a number of physiological functions, like respiration, heart rate, muscle tension, hand temperature and galvanic skin conductance, the therapist can get a clear view of the way this particular body responds to stress.
Using biofeedback the therapist can see in real-time whether the client is able to relax when the stress is no longer there. Moreover, the therapist can really test the efficacy of a relaxation exercise, so he or she can give better advice about which relaxation exercise is best.
Stress profiling makes it possible for the person to understand his or her complaint and gives the therapist a tool to determine what kind of therapy is needed to tackle the stress related problem.
A standardised stress profile (such as that provided by BioTrace+ software linked to a NeXus biofeedback unit) could be adopted, measuring muscle tension in both trapezius muscles, respiration, heart rate, hand temperature and skin conductance.
The test starts with a baseline of 6 minutes, in which the subject is reading in silence. We need to avoid the subject being "occupied" with relaxing. Then periods of relaxation, marked green in the graphs, are alternated with mental stressors, marked red in the graphs. The stress test ends with a particular breathing exercise, which is slow breathing at a rate of 5-8 breaths per minute, dependent on the normal breathing rate of the person. The stressors used are mental stressors, in the following order: 1) saying the alphabet backwards out loud, 2) think of as many animals as you can starting with the letter R and 3) a maths task such as counting backward from a large number in steps of seven. This 20 minute stress profile offers a lot of valuable information for both client and therapist.
If you would like to read about case studies using Stress Profiling with the NeXus biofeedback units see the article by Matto referenced below
Cechetto, David E (2004)
"Forebrain control of healthy and diseased hearts"
Chapter 7 in Basic and Clinical Neurocardiology
Edited by J Andrew Armour & J L Ardell, Oxford University Press
Matto, Danielle M (
The added value of psychophysiological stress profiling
http://www.bfe.org/library/Psychophysiology Today vol 8 issue 1 August 13 (1).pdf#page=9