A person's heart rate can reveal a lot about how they make decisions when feeling stressed, a Queensland University of Technology academic says.
Economics Associate Professor Uwe Dulleck, from the QUT Business Faculty, said stress in the workplace wasn't necessarily a bad thing, because it was, in fact, a natural reaction that had been given a negative connotation.
Professor Dulleck is leading the Australian arm of a study that was awarded an Australian Research Council grant to study the effects of both positive and negative stress on workers' decision-making.
"The study will use heart rate monitors to measure the stress of people 'on the job' and in the controlled environment of an experimental economics computer laboratory as they interact and communicate," Professor Dulleck said.
"We will measure how much they are stressed in certain situations and whether that is positive or negative stress, this will be measured against how they behaved and what decisions they made - whether they made rational or emotional decisions."
Professor Dulleck said negative stress could be detected by measuring a person's heart beat and its variations over short intervals of time.
"If the heart rate varies, it shows that the body is relaxed with an activity and is feeling positive stress," he said. "In this case the body is more flexible to react to the demands of the situation".
"But if the variations are very limited it shows that the body is not at ease with this activity. This kind of stress hardens the body and makes it operate in a more regular way. In such situations, the body works more like a motor engine - highly efficient in some respects but also more likely to break if unexpected challenges arise.
"We are trying to find what effect this has on decision-making."
Professor Dulleck said study participants would be monitored as they played two games: a game of chance to see what kind of decisions they made when uncertain; and a negotiation game, both before and after socialising with their "opponent", to see what affect communication had on cooperation.
"We will also look at whether they took high or low risks in the game of chance, to learn about attitudes towards risk and whether an individual's worry is over losing money, or the risk of chance itself," he said.
Professor Dulleck said knowing what caused positive and negative stress in individuals and what effect this had on decision making would help businesses improve work for their staff and managers.
"Knowing how stress affects people's behaviour will help in designing training programs for employees as well as achieving a better work-life balance and avoiding burn-out syndromes," he said.
The study is being undertaken in conjunction with Associate Professor Benno Torgler and Dr Cameron Newton from the QUT Centre of Philanthropy and Nonprofit Studies, and three Austrian business partners; a human resources company, a construction company and a nonprofit organization. 
Men's health News From Medical News Today
Wednesday, August 13, 2008
Decisions Under Pressure: It's All In The Heart Beat
Yoga And Meditation Change Gene Response To Stress
Research from the US suggests that mind body techniques like yoga and meditation that put the body in a state of deep rest known as the relaxation response, are capable of changing how genes behave in response to stress.
The study is the work of researchers at Benson-Henry Institute for Mind/Body Medicine at Massachusetts General Hospital (MGH) and the Genomics Center at Beth Israel Deaconess Medical Center (BIDMC) and is published online in the open-access journal PLoS One.
Mind-body practices that produce a relaxation response have been used by people across cultures for thousands of years to prevent and treat disease, wrote the authors in their background to the study.
The relaxation response is characterized by reduction in oxygen intake, increase in exhalation of nitric oxide, and lower psychological distress. Many experts see it as the counterpart to the "flight or fight" stress response that has already been shown by a number of studies to have a distinct pattern of physiological and gene expression changes (called "transcriptional profile").
The researchers for this study wanted to test the idea that the relaxation response also produces changes in gene expression.
The researchers recruited three groups of people. In the first group (called the M group) there were 19 long term practitioners who had been practising various ways of producing the relaxation response every day for a long time (for instance with daily yoga, repeated prayer or meditation practice).
In the second group were another 19 people who they called the "healthy controls" (group N1), who were not daily practitioners, and the third group was like the healthy controls group, except these 20 people completed 8 weeks of relaxation response training (this group was N2).
The researchers assessed transcriptional profiles of the people in all three groups from blood samples.
They found the expressions of a total of 2,209 genes were significantly different between groups M and N1, and a total of 1,561 genes were similarly significantly different between groups N2 and N1.
More importantly, however, was the fact 433 of the genes were common to both sets of comparisons: the same ones were different between M and N1 and between M and N2, so even short term practise of the relaxation response appeared to produce changes in these 433 gene expressions.
Further analysis using techniques called gene ontology and gene set enrichment, showed that groups M and N1 (the long term and the short term practitioners of the relaxation response) exhibited similar physiological changes such as in "cell metabolism, oxidative phosphorylation, generation of reactive oxygen species and response to oxidative stress".
A second phase of the study involving 5 N1 healthy controls, 5 N2 short term practitioners, and 6 M long term practitioners, was done to validate a significant number of genes and pathways.
The authors concluded that:
"This study provides the first compelling evidence that the RR [relaxation response] elicits specific gene expression changes in short-term and long- term practitioners."
They wrote that their findings suggest:
"Consistent and constitutive changes in gene expression resulting from RR may relate to long term physiological effects," and that "Our study may stimulate new investigations into applying transcriptional profiling for accurately measuring RR and stress related responses in multiple disease settings."
Dr Herbert Benson, director emeritus of the Benson-Henry Institute and co-senior author of the study said:
"Now we've found how changing the activity of the mind can alter the way basic genetic instructions are implemented," said Benson.
Dr Towia Libermann, director of the BIDMC Genomics Center and also co-senior author of the study added that:
"This is the first comprehensive study of how the mind can affect gene expression, linking what has been looked on as a 'soft' science with the 'hard' science of genomics."
"It is also important because of its focus on gene expression in healthy individuals, rather than in disease states," explained Libermann.
The authors said their study showed that the relaxation response changed the expression of genes involved with inflammation, programmed cell death and the handling of free radicals. Free radicals are normal byproducts of metabolism that the body neutralizes in order to stop damage to cells and tissues.
Co-lead author of the study Dr Jeffery Dusek formerly of the Benson-Henry Institute and now with the Abbott Northwestern Hospital in Minneapolis said:
"Changes in the activation of these same genes have previously been seen in conditions such as post-traumatic stress disorder; but the relaxation-response-associated changes were the opposite of stress-associated changes and were much more pronounced in the long-term practitioners."
Benson said that people across different cultures have been using mind body techniques for thousands of years. They found that it didn't particularly matter which techniques was used, whether it was meditation, yoga, breathing, or repetitive praying, they acted via the same underlying mechanism.
"Now we need to see if similar changes occur in patients who use the relaxation response to help treat stress-related disorders, and those studies are underway now".
Libermann said they used "cutting edge" genomic analysis and the "latest bioinformatics tools to identify potential gene functions, generating hypotheses that can then be tested in laboratory or clinical studies."
"There are a lot of differences in gene expression between one healthy person and another, so it is challenging to analyze the kinds of subtle changes we are seeing and identify what changes are significant and what are just background noise," explained Libermann.
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Gene/Stress Interaction Increases Cognitive Decline In Elderly
The negative effects of stress on cognitive functioning appear to be amplified by a genetic variation associated with Alzheimer's disease, a new federally funded study has found. The genetic variation may, in effect, accelerate the development of age-related cognitive decline by as much as eight years.
Researchers from the Baltimore Memory Study report in The American Journal of Psychiatry (AJP), the official journal of the American Psychiatric Association, that a high level of the stress hormone cortisol in study participants aged 50 to 70 years was associated with worsened cognitive abilities. The researchers also found that the effect was greater among those with a common form of the gene for apolipoprotein E (APOE), which has been shown to increase the risk for Alzheimer's disease.
This gene-environment interaction is reported by Brian Lee, M.H.S., Brian Schwartz, M.D., and colleagues at Johns Hopkins University. The group's findings will be presented online on July 1 under AJP in Advance . The effect appears to increase as the number of copies of a specific APOE gene in the individual increases. Everyone inherits two versions of the APOE gene, known as alleles - one from each parent. The most common APOE alleles are epsilon-2, -3, and -4. Having at least one epsilon-4 allele increases an individual's risk of late-onset Alzheimer's disease. Individuals with two copies of the esiplon-4 version of the gene are particularly susceptible to the damaging effects of cortisol in the brain.
"Our findings indicate that the APOE epsilon-4 allele may increase vulnerability of the aging brain to elevated cortisol levels," said lead author Lee, a doctoral student in epidemiology at the Johns Hopkins Bloomberg School of Public Health. "While our results remain to be replicated, the observed cortisol-APOE interaction is intriguing since both cortisol and APOE have been implicated in cognitive decline associated with aging as well as in Alzheimer's disease."
The effects on cognitive functioning extended to six of the seven areas that were studied: language, eye-hand coordination, executive functioning, verbal memory/learning, visual memory, and ability to copy a complex visual design.
The deficits are similar in magnitude to those seen with advancing age. The authors estimated the equivalent years of increased age, represented by the poorer cognition of the study participants with high cortisol and the epsilon-4 form of the APOE gene. For language ability, the lower scores of people with high cortisol levels and one epsilon-4 copy were comparable to an age increase of eight years. For those with two epsilon-4 copies, the comparable age increase was even larger.
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