Alleviating PTSD Stress and Risk in Fighters – ScienceDaily

According to the researchers, such a technique could provide measures facilitating the development of procedures to alleviate stress and the emergence of conditions such as post-traumatic stress disorder in combatants.

"The human brain is considered by many to be the most complex organ in existence, with more than a billion neurons and over a billion interconnections," said Dr. Bruce West , Senior Scientist in Mathematics and Information Science at the US Army Research. Office and ARL member.

According to West, it is the functioning of this extraordinary complex network of neurons that harbors human thought, and through the central nervous system, that allows the functioning of most, if not all, physiological networks, such as cardiovascular.

However, according to the researchers, even with the central role that the brain plays in enabling our existence, very little is known about how it works.

Therefore, measures of how the brain performs its various functions are key indicators for understanding, particularly for maintaining the health and well-being of military personnel.

A small but measurable electrical signal generated by the mammalian brain was captured in the electrocardiogram of small animals by Caton in 1875 and in human brains by Berger in 1925.

Norbert Wiener, half a century later, provided the mathematical tools needed to penetrate the mysterious relationships between brain waves in EEG time series and brain function.

According to West, progress in this direction has been slow and, after more than a century of data collection and analysis, there is no EEG motif taxonomy that delineates the correspondence between these models and brain activity. .

The technique developed by West and his academic partners generalises the evolutionary game theory, a mathematical technique historically used in the formulation of decision-making in war games.

Their findings are reported in an article published in the August issue of The boundaries of physiology.

In this article titled "Bridging Waves and Crucial Events in Brain Dynamics," West, with Gyanendra Bohara and Paolo Grigolini of the University of North Texas, successfully proposes and tests a new model of collective behavior in the brain. which bridges the gap between the waves and the random fluctuations of the EEG data.

"The starting point for military decision-making has historically been game theory, in which players cooperate or discard each other, and with pairwise interactions receive different payoffs for certain strategies to always win," said West. "When the game extends to groups in which individual strategy choices are made sequentially and can evolve over time, the situation evolves and offers a wider variety of outcomes, including the formation of collective states in which collective. "

It turns out, says West, that the technique developed to process EEG data, the self-organized time criticality method, or SOTC method, incorporates a strategy that is an extension of the evolutionary game theory in modeling the brain dynamics.

"The collective or critical state of the neural network is reached spontaneously by the internal dynamics of the brain and, as for all critical phenomena, its emergent properties are determined by the macroscopic scale independently of the dynamics at the microscopic scale.

This macroscopic scale is directly accessible by the EEG spectrum.

The EEG spectrum, obtained by the SOTC method, decays as the Brownian motion at high frequencies, peaks at an intermediate frequency (alpha wave) and has a reverse power law at low frequencies.

In the case of the brain, the reverse power law has revealed that there is a wide range of time scales on which the brain is able to meet the demands placed on it.

This spectrum suggests flexibility in response, reflecting a potential range from concentration on a single task for hours to a quick fight against physical aggression.

"This means that in the foreseeable future, the physical training of the warriors, as well as the necessary follow-up of the progress associated with this training, will be extended to the brain," said West. "The reliable treatment of brain activity, as well as the interpretation of the treated EEG signal, will guide the development of reliable techniques to reduce stress, improve situational awareness and increase the ability to manage the patient." uncertainty, both on the battlefield and on the outside. "

West said the research team even speculates that such an understanding of brain dynamics can provide the information needed to mitigate the onset of PTSD through early detection and intervention, as is commonly done. for more obvious diseases.

According to West, going forward with this research can go in at least two ways.

"One of the solutions is to apply these promising results to sets of data relevant to the military," said West. "For example, to quantify how the EEG recordings of warriors with PTSD differ from a control group of warriors and how this measure changes under different therapeutic and drug protocols.The other method is to refine the technique, for example is the most robust, while maintaining sensitivity. "

Whatever the case may be, these Army scientists strive to carry out the technology to help the soldier of the future succeed in an ever changing world and battlefield.

Earlier this year, the research team published work on treating heart rate and the indirect influence of heart rate on brain dynamics. This work examined how the brain influences the functioning of the body by directly measuring how the physiological system (cardiovascular in this case) responds to changes in the brain (through meditation).

This current work focuses on the processing of EEG data and the direct interpretation of brain dynamics; It examines how the rhythmic behavior of brain waves (alpha, beta, gamma waves, etc.) can be considered compatible with fluctuations in brain wave data.

Both articles are part of an ongoing ARL-University of North Texas study to determine whether fluctuations in all physiological systems are produced by a previously unidentified mechanism that we call critical events.