Following several collisions involving American warships between 2017 and 2019, one of which claimed the lives of seven sailors, U.S. Navy leadership investigated the causes.
A 2019 report published by the Naval Health Research Center states that “problems in decision-making among the ship’s crew members may have been an important contributing factor” and that “stress may have played a role.”
“Shipboard sailors encounter high levels of stress, as shipboard operations come with unique and often intense stressors that affect the readiness of service members,” the document states. “Although stress can sometimes be motivating, exposure to intense or prolonged stressors has well-documented adverse effects on decision-making and operational performance.”
To prevent such accidents in the future, the Naval Health Research Center examined several programs to help sailors learn how to cope effectively with stress, maintain focus under pressure, and strengthen their ability to withstand difficult and dangerous situations. One such program was the Stress Resilience Training System, developed with the California-based HeartMath Institute.
As part of the program, 92 crew members from one ship were each given an iPad loaded with a dedicated app featuring a biofeedback system that displayed the user’s heart activity in real time. The app incorporated simulations allowing participants to practice techniques they were taught, such as breathing exercises and emotion-shifting methods, in various challenging scenarios. The goal of the exercises was to rapidly reframe feelings of stress and replace them with positive emotions, such as gratitude or care for a loved one.
To assess the program’s impact, the ship’s crew participated in a series of cognitive tests, which were administered twice, at the start of the study and again after eight weeks of using the app. The tests measured decision-making ability, information-processing speed, attention, and planning.
By the end of the eight weeks, the most significant improvement was found in decision-making test scores, which showed an average increase of 65 percent. Information-processing speed also improved, although modestly, at 14 percent.
How did this happen? The answer lies in changes in heart activity, a subject that the HeartMath research team has been studying for many years. In 1995, the team conducted a preliminary study examining the relationship between emotions and heart activity, and the way that that activity subsequently affects brain function.
The study found a connection between the emotions people experience and a physiological measure called heart rate variability (HRV), which examines the small fluctuations in heart rate, or the differences in time intervals between heartbeats.
In the past, a steady heart rate was considered a sign of good health, but today it is known that higher variability (high HRV) actually indicates better physiological flexibility. This flexibility signifies that the heart and nervous system can efficiently adapt to changing demands, such as speeding up during physical activity and slowing down during rest. A person with high HRV tends to cope better with physical exertion, stress, and environmental changes.
In that 1995 study, lead researcher Rollin McCraty and his colleagues instructed participants to enter two contrasting emotional states: recalling an event that made them angry and evoking a feeling of appreciation toward someone. Analysis of their cardiac electrical activities revealed a striking difference: When participants got angry, only an increase in low-frequency bands was recorded, whereas when they showed appreciation, an increase was observed in both low and high frequencies. This difference affected the participants’ HRV.
From Chaos to Coherence
In another study published by the institute’s researchers a year later, they deepened their analysis of HRV data. In that study, 20 subjects were asked to use breathing exercises and meditation to generate positive emotions of appreciation, care, or love. The researchers examined HRV data minutes before and after the exercises.
When the results were plotted on a graph, a striking change was visible: The graph shifted from being chaotic to a much smoother and more ordered pattern. This pattern was defined several years later by the institute’s researchers as “coherent” and reflected the positive effect of emotional feelings on heart rhythm.
“When we’re feeling stress, frustration, anger, anxiety, or worry, the heart rhythm pattern becomes jagged and irregular, and that signal is sent from the heart to the brain,” Deborah Rozman, a leading researcher at HeartMath, said in a lecture posted by Science and Nonduality.
“When we’re feeling love, genuine care, compassion, kindness, and appreciation, all the qualities we associate with the heart, we see this beautiful sine wave, a coherent pattern at the bottom, and the heart brain is sending that pattern to the head brain.”
When such an ordered signal reaches the brain, she said, it contributes to the global synchronization in the brain, so that the brain can operate at its peak capacity.
In a review article published by the institute in 2009, researchers explained that they measured alpha waves in the brain and observed their synchronization with heartbeats. They also noted a specific frequency at which the heart rate stabilizes in a sinusoidal pattern. Additional studies pointed to the correlation between brain alpha waves and heart activity during certain emotional states.
McCraty and his colleagues argued in their papers that in a state of coherence, the heart, being a powerful rhythmic oscillator, can entrain the rhythms of other systems in the body, causing them to synchronize with it. In other words, the heart “pulls” breathing, blood pressure, and even other brain rhythms to align with its frequency, creating an overall harmonious synchronization among the body’s systems. McCraty explained that this illustrates how synchronization spreads beyond the brain and affects other bodily systems as well, which converge together into ordered and harmonious patterns.
The institute quickly discovered that biofeedback processes, in which a person receives immediate feedback on the physiological changes in their heart activity, as in the case of the Navy personnel, can help them shift their emotional and physiological state. Through techniques that amplify positive emotions, a person can reach a state of “coherence” with relative efficiency.
Beyond Performance Under Stress
The coherent state offers many benefits. From a health and physiological standpoint, studies have shown that a coherent state contributes to reduced blood pressure in hypertensive patients and to pain relief in people suffering from chronic pain. Similar effects have been observed on the mental level: A coherent state helps women suffering from postpartum depression and patients coping with post-traumatic stress.
The institute’s researchers explained that coherence arises from an interaction between two central nervous systems in the body: the sympathetic nervous system, which is responsible for arousing the body under stress and activating the “fight or flight” response, and the parasympathetic nervous system, which promotes states of calm and recovery.
Rozman explained that in a state of coherence, “the sympathetic and parasympathetic nervous systems are entrained so their powers are working together.” In other words, when we experience anger, frustration, or similar emotions, there is no coordination between the two systems, and each tries to influence heart rate in opposite directions. In contrast, when we show care, kindness, compassion, love, or gratitude, the two systems are coordinated, creating a balanced and harmonious heart rhythm.
The institute’s researchers explained that there is an important difference between relaxation and coherence. In a state of relaxation, the body simply “downshifts”–our nervous system calms down, the heart rate becomes uniform, and the activity of our parasympathetic system (the one responsible for rest and relaxation) increases. Our body is in deep rest, or a state of “low energy.”
Whereas in the state of coherence, the heart and brain work together in a synchronized and harmonious way. We feel calm and focused, yet vital. The body operates at an organized frequency, enabling a better and more balanced response to the environment.
A surprising study by McCraty and colleagues even demonstrated a connection between coherent heart activity and heightened intuition. Twenty-six subjects, trained in HeartMath techniques and able to enter a coherent state, participated in an experiment in which they were shown 45 images—15 emotionally arousing and 30 calming—in two rounds. In one round, they were asked to maintain a coherent state, and in the other, a normal baseline state. The order of the rounds was randomly assigned for each participant. Participants’ heart activity was recorded throughout the experiment.
It turned out that participants’ heart rates decelerated significantly before the emotionally arousing images were shown, whereas no significant deceleration was observed before calming images. In other words, the heart appeared to respond intuitively: It began slowing down in anticipation of an emotionally charged image, as if preparing the body for what was coming; before the calming images were shown, the heart rate remained relatively stable, because the body intuitively “sensed” that there was no need to emotionally prepare itself.
When participants were in a state of coherence, the intuitive effect became even clearer. Before each set of images, participants tried to focus on the heart and maintain a positive emotion, such as appreciation or care, for a short period of time. Some (particularly women) showed a significant heart rate deceleration to future emotional stimuli, suggesting that a coherent state may enhance intuitive sensitivity.
“The heart was sending different neural signals from the heart to the brain, all the way to the frontal lobes, and the brain responded before the computer randomly selected the picture,” Rozman said. “What we found is that people who were practiced in heart coherence … were more connected with the heart’s intuitive guidance.”
This article was originally published by Epoch Magazine Israel.