Effects of Sensory-Enhanced Yoga on Symptoms of Combat Stress in Deployed Military Personnel

Effects of Sensory-Enhanced Yoga on Symptoms of Combat Stress in Deployed Military Personnel

By: Carolyn C. Stoller, Jon H. Greuel, Lucy S. Cimini, Mary S. Fowler, Jane A. Koomar

Summary:

The authors of this study examined the effects of “sensory-enhanced hatha yoga on symptoms of combat stress in deployed military personnel, compared their anxiety and sensory processing with that of stateside civilians, and identified any correlations between the State–Trait Anxiety Inventory scales and the Adolescent/Adult Sensory Profile quadrants.” Studies have shown that traditional healthcare treatments for post-traumatic stress disorder(PTSD) such as talk therapies have had limited success. Non-conventional healthcare treatments such as yoga incorporates breath work and movement which increases heart rate and reduces symptoms of PTSD. According to a Walter Reed Medical Center study, yoga nidra reduced the severity of insomnia, depression, anxiety, and fear, all symptoms on the PTSD list.

The authors of this study used a randomized control trial to research the effects of sensory-enhanced hatha yoga on combat stress. Participants had to be deployed to Forward Operating Base Warrior, Kirkuk, or Iraq. Military personnel were contacted by email and flyers to participate in the study. The study consisted of 35 treatment and 35 control participants. According to the authors, “Of the 70 participants, 20 were in the U.S Army and 50 were in the U.S Air Force; 22 were women and 48 were men.” The treatment participants took part in hatha yoga classes for three weeks, seven times a week, a minimum of nine times during the three week period.

Overall, sensory-enhanced hatha yoga was effective in reducing anxiety. Military personnel “showed significantly greater improvements than control participants on 16 of 18 mental health and quality-of-life factors.” Of the 70 participates, 54 percent showed sleep improvements, 37 percent felt more relaxed, 26 percent felt an increase in physical benefits, and 11 percent reported better frustration and anger management. The results of this study supports the use of sensory-enhanced hatha yoga to control and manage combat stress.

Critique:

The authors of this study provided strong evidence that sensory-enhanced hatha yoga reduced PTSD and combat stress. However, I would have liked to gain a better understanding of the background of the participants such as, how long they were deployed and what military occupation specialty they held while in deployment.

Source:

Stoller, C. C., Greuel, J. H., Cimini, L. S., Fowler, M. S., & Koomar, J. A. (2012). Effects of Sensory-Enhanced Yoga on Symptoms of Combat Stress in Deployed Military Personnel. American Journal of Occupational Therapy, 66(1), 59–68. doi:10.5014/ajot.2012.001230

Exercise and the brain: something to chew on

Summary:

Concerning dieting and cognition, Van Praag (2009) found that limited intake reduced the risk of attention deficit.  The intake of a variety of dietary supplements enhanced learning for both animals and humans.  Specifically, fish oil, teas, fruits, folate, spices, and vitamin improved cognitive functions.  While results were only found in rats, particular foods that increased memory are plant-derives foods like grapes, blueberries, strawberries, tea, and cocoa.  Van Praag hypotheses that flavanol in plant-derived foods are the primary ingredient responsible for this increase in cognition.  When dieting is combined with exercise, epicatechin is very effective in enhancing memory and synaptic plasticity.

Exercise is also an effective mechanism to increase cognition.  Past studies have shown that exercise enhances neurogenesis.  Neurogenesis refers to the generation of neurons and connections, or synapses, between those neurons.  An increase in the number of neurons and synapses equates to an increase in memory generation, memory recall, and learning.  Most interestingly, most of the neurogenesis occurs in the hippocampus, the area of the brain most responsible for learning and memory.  As shown by the diagram, diet and exercise work simultaneously to enhance cognitive functions.  

Diagram of diet & exercise effects on cognition. Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680508/

Critique:

Assuming that brain cognition does benefit intelligence analysis in some fashion, diet and exercise does improve cognition (thus intelligence analysis).  It appears that analysts would benefit most from a high-fruit diet combined with regular exercise.  The duration, frequency, and intensity of exercise are unknown, especially since many of Van Praag’s conclusions are based on rats.  However, the genetic similarities between humans and rats, as uncomfortable an idea that is to some, may provide enough grounds for analysts to improve their wellness.

Source:

Van Praag, H. (2009, May 12). Exercise and the brain: something to chew on. Retrieved October 14, 2014, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680508/

Effects of Tyrosine, Phentermine, Caffeine d-amphetamine, and Placebo on Cognitive and Motor Performance Deficits During Sleep Deprivation

Summary
A 2003 Department of Defense sponsored experiment studied the effects of various drugs on analytic performance during the course of 40.5 hours of sleep deprivation found that all medication tested significantly improves performance in running memory, logical reasoning, mathematical processing, tracking and visual vigilance tasks during periods of continuous sleep deprivation. All the drugs tested improved some aspects of cognitive and motor performance during sleep deprivation compared to a placebo. The subjects realized the most significant effects during states of sleep deprivation for tasks requiring speed and accuracy.

The literature on the effects of sleep deprivation attributes performance failures to cognitive slowing, memory encoding problems, retrieval problems, reductions in vigilance, deterioration of response time, increased frequency of non-responses, and increased frequency of false responses.  

This experiment investigated and compared the effects of a placebo versus other treatment groups consisting of 20 mg of D-amphetamine, 300 mg/per 70 kg body weight of caffeine, 37.5 mg of phentermine, or 150 mg/per 1 kg of body weight of tyrosine after 32.5 hours without sleep on a series of eleven performance tests administered to 76 individuals in a laboratory set up for the experiment. 

The experiment took place over 5 days demarcated over four phases: Baseline (Days 1-3), Sleep Deprivation (Days 3-4), Medication (Day 4) and Recovery (Day 5). The researchers collected performance test data eight times during the Baseline period and again every 4 hours during the night of no sleep. After 32.5 hours of no sleep, the researchers administered the drug doses to the applicable treatment groups after which two further performance test batteries took place after 34 hours of no sleep and after 38 hours of no sleep. Four additional test sessions took place during the Recovery period. 

Outline of protocol from Figure 1.

The performance tests in the test battery were (in order administered): 

1. Visual Scanning Task: Subject required to scan a matrix of letters to locate the letter K. Subject performed 20 trials per session and performance measure was amount of time to locate the correct letter. 
2. Running Memory Task: Subject viewed series of 80 individually presented letters. When each letter was presented, subject indicated presented letter was same or different from the letter shown previously. Performance measures were percent correct and response delay time (RT). 
3. Logical Reasoning Task: Subject viewed statement in the form A is followed by B then a letter pair was presented and subject indicated whether or not the letter pair relationship was congruent with preceding statement. Subject performed 80 trials per session. Performance measures were response latency per response (RT) and number of errors per session. 
4. Mathematical Reasoning: Subjects solved addition or subtraction problem and indicated whether the answer is greater than or less than five. Subject performed 80 trials per session. Performance measures were percent correct and average response latency (RT) per correct response. 
5. Stroop Task: Subject viewed words RED, GREEN, AND BLUE one at a time. On each presentation, the letters could be red, blue, or green in color. Subject responded according to the color of the letters. Subject performed 80 trials per session. Performance measures were percent correct for congruent and incongruent word-color items and average response latency (RT). 
6. Four-choice Serial Reaction Time Task: Subject saw blinking + sign in one of four quadrants and responded as quickly as possible by pressing a corresponding keyboard key. The + remained visible until subject pressed a key and randomly appeared in one of four quadrants for next trial. Subject performed 75 trials per session. Performance measure was reaction time (RT) for correct responses. 
7. Time Wall Task: Subjects observed an object descend from the top of the monitor at a constant rate toward a target at the bottom of the monitor and the target disappeared after the object descended two-thirds of the way down the screen. Subject pressed a key at the estimated time that the object would contact the target, 20 trials per session. Performance measure was amount of timing error. 
8. Pursuit Tracking Task: Subject saw two cursors in the center of a monitor. Subject moved the mouse to make the top cursor follow the bottom target cursor as closely as possible as it moved at a constant rate across the screen for 3 minutes. Performance measure was amount of error per unit of time for subject cursor deviations from target cursor. 
9. Visual Vigilance Task: Subject observed darkened computer monitor for 40 minutes. At random intervals, a small dim light appeared somewhere on the monitor. The subject pressed an appropriate key when subject detected the dim light on monitor. Performance measures were number of correct responses (out of 40 possible) and the average response latency for correct responses.
10. Trails (B) Task: Subject given sheet of paper with a series of randomly arranged letters and numbers. Using a pencil and starting at number 1, subject traced a path between each succeeding number and letter (i.e. 1-A-2-B etc). Performance measure was time to completion. 
11. Long-term Memory Task: Subjects verbally given a sentence at the beginning of session. Included in sentence was 12 pieces of factual information. After 90 minutes, subject wrote down as much of the sentence as could be remembered. Performance measure was number of correct pieces of information recalled.

Interestingly enough, not every task showed performance deficits due to sleep deprivation. 

Results for tasks that showed performance deficits related to sleep deprivation from Table II.

Tasks involving performance measures related to time stress such as speed and accuracy showed more consistent performance deficits during sleep deprivation than performance measures related to accuracy alone. All four drugs had a primary performance benefit of an improved response delay time, with auxiliary benefits in reduction of error for visual vigilance and pursuit tracking tasks. 

Prior to this research, the performance improvements from D-amphetamine and caffeine were well known by the body of literature. In contrast, phentermine and tyrosine were not. The article indicates that phentermine has very low abuse potential and mimicked the performance affects of D-amphetamine. The effects of Tyrosine supplementation were delayed compared to the effects of other substances (effects on performance not realized until 5.5 hours after dose administration compared to 1.5 hours for other substances) but a perceived benefit is that Tyrosine is a naturally occurring, non-essential amino acid with no known potential for physiological addiction abuse.

Critique
An issue with performing the same type of tests repeatedly within the same treatment groups is improvement related to learning how to "game" a test rather than improvement related to the consumption of performing enhancing drugs. The researchers administered a freebie "pretest" on the first day of the experiment yet the researchers indicate that eight sessions during the Baseline period were needed to overcome learning effects based on pilot research findings. The statistical analysis assessed performance data for 10 of the 18 testing sessions. Only four sessions on Day 3 were considered as baseline performance. Day 5 sessions representing the recovery period after sleep deprivation were also excluded.

An organization-wide adoption of drugs to mitigate performance deficits due to sleep deprivation during critical time crunches must additionally factor tolerance and withdrawal effects. Even a psychoactive drug perceived as relatively benign like caffeine can induce symptoms of psychosis such as hallucinations and hearing voices at large enough doses in otherwise healthy individuals according to 2009 research at Durham University and consistent use of 300 mg per day of caffeine is enough to cause tolerance side effects. 


Sources

Richard A. Magill; William F. Waters; George A. Bray; Julia Volaufova; Steven R. Smith; Harris R. Lieberman; Nancy McNevin; Donna H. Ryan. "Effects of Tyrosine, Phentermine, Caffeine _d-amphetamine, and Placebo on Cognitive and Motor Performance Deficits During Sleep Deprivation." Nutritional Neuroscience. 2003  

Simon R. Jones; Charles Fernyhough. "Caffeine, stress, and proneness to psychosis-like experiences: A preliminary investigation." Personality and Individual Differences. 2009

The Effects of Caffeine on Cognitive Fatigue

Summary

A study performed by Sunni Newton (2009) sought to examine the effect of caffeine on cognitive fatigue. This study examined the effects of caffeine on performance and self report mood measures during the execution of complex cognitive tasks. The end results of this study showed that complex task performance improved while using caffeine.

Cognitive fatigue is a factor that decreases task engagement and increases the resistance to further exert energy towards a task. Cognitive fatigue observed through changes in a person’s work performance, their physiological processes, and subjective feelings.  

To perform this study, Newton split 116 participants into two groups, a control group that was given a placebo and an experimental group that was administered a dose of caffeine. Participants received the caffeine dose (170mg) or the placebo by chewing two pieces of gum after the first hour of the test. The dose was given after an hour to ensure that a baseline was gathered for the experimental group.

Groups of 2 to 12 persons participated in a 4.5 hour testing session which alternated between self report questionnaires and exam questions. The questionnaire solicited responses from the participants regarding alertness and their perceived level of fatigue, while the exams were problems sets composed of 8 questions. Newton compiled the questions from college textbooks on the following subjects: science, history, English, and human interest.

The results of the study, which Newton analyzed using an ANOVA, showed that the placebo group reported a greater amount of fatigue throughout the test while the caffeine group reported less fatigue and performed better on the complex tasks.

Figure 1. Mean hourly test performance for caffeine and placebo conditions

Critique

This study was well constructed and executed. The choice to administer the caffeine dose an hour into the test was well thought out and further highlighted the effects of caffeine on task performance. An examination of the effects of caffeine on performance over a longer test time would be interesting to see.

Additionally, participants only had 6 minutes to complete each of the test questions. The constant changing of topic and requirement may have served as a stimulus to the placebo group. It would be beneficial to examine the performance on tasks that take a greater amount of time to complete

Source:

Newton, Sunni. (2009). The effects of caffeine on cognitive fatigue. Georgia Tech University.

Effects of acute bouts of exercise on cognition

Summary:

In his 2003 journal article, Phillip Tomporowski addresses how short periods of exercise affect our cognitive thinking abilities.  He identifies that there is plenty of literature showing that brief bouts of exercise improve both the mood of the participant, as well has their ability to think clearly.  Exercise has also been linked to reducing stress levels as well as anxiety and depression.  At the time of this research though, there was very little evidence to support the hypothesis that short periods of exercise improve cognitive brain functions.

Tomporowski conducted a literature review of the relevant studies relating to exercise and cognitive abilities.  The research was broken into three categories: studies that focused on  1) intense exercise 2) the relation of exercise induced arousal 3) long aerobic physical activities.

1) Relationship of intense exercise on cognitive thinking abilities

At the time, research on intense exercise and its link to cognitive thinking was examined by pushing the subject to near exhaustion (using fast running or biking exercises) and then conduction either a visual or oral test.  The effects of intense exercise on visual cognitive tasks, such as viewing maps and determining distance and routes, did not tend to be affected by intense cardiac workouts.

Studies did find a transient effect on the participants cognitive thinking abilities when presented with problems that required greater response preparation.  Wrisberg and Herbert (1976) only found this deterioration in response time and accuracy to have only a small deduction in thinking abilities.

2) Relationship of exercise induced arousal on cognitive thinking abilities.

Exercise induced arousal has presented many different findings on the participants cognitive thinking abilities.    There is some evidence that suggest it works in a reverse U shape.  For example, Salmela and Ndoye (1986) found that cognitive abilities were highest at 115 beats per minute than at rest or at 145 beats per minute.  Levitt and Gutin (1971) had similar findings were cognitive abilities peaked at 115 beats per minute, reached resting level at 145 beats per minute, and decreased at 175 beats per minute.

Many of the journals Tomporowski reviewed did not show reverse U shape relation to the participants cognitive abilities.  Much of the literature relating to visual recognition showed an increase in visual identification responses.  Allard et al. (1989) found visual recognition to be at its highest when participants were cycling at the highest level of intensity, contradictory to the reverse U shape model suggested by other researchers.

3) Long aerobic physical activities on cognitive thinking abilities

As with the other two categories, there was no agreed upon conclusions.  Travlos and Marisi (1995) found no increase in cognitive cognitive abilities during 50-min cycling exercises where the reaction time of participants were tested.  The same was found by Tomporowski et al. (1987) when testing college students memory during extended periods of running.

Other studies found that prolonged excise helped facilitate decision making processes.  Tests were administered during the exercise as well as during the cool down phases.  In both cases, participants speed in making decisions greatly increased.

Critique:

Tomporowski's literature review of the effects of exercise on cognitive abilities present a great deal of unanswered questions.  A majority of the findings are inconclusive and contradictory to other similar findings.  There are two key takeaways from this that I find important to intelligence analysts.

1) In all three of the categories, there was evidence to suggests that exercise helps improve cognitive tasks involving visual recognition and interpretation.  These results were best while the participant had an elevated heart rate.  Geospatial analysis is one area that I feel could best benefit from exercise and increasing the heart rate of the analysts.  Simple exercises, such as push-ups, jumping jacks, sit-ups, and running in place may help offer boosts in visual recognition to analysts.

2) A majority of the evidence suggests that excise does have some kind of influence on cognitive thinking.  There are many ways to help analysts have an elevated heart rate at work.  Examples include standing desks and treadmills with desks attached.  Exercise facilities located in the building are other options.  While I agree that research must continue into the influence exercise has on cognitive thinking, the intelligence community should start considering exercising as a tool to help improve the short term cognitive abilities of their analysts.

Source:

Tomporowski, Phillip D (2003).  Effects of acute bouts of exercise on cognition.  Acta Psychologica.  P. 297 - 324.