The human being is the final result of an evolutionary process in which our physiological, anatomical and neuropsychological systems have been developed and perfected. In this sense, in relation to our environment, the neurophysiological responses of our nervous system in stressful situations such as military combat will be governed by phylogenetically modulated circuits, such as the fight and flight reflex, which prepares the organism for survival. As soon as the organism detects a situation that is aversive or compromising its integrity, this information travels to the amygdala, whose neuronal compendium is in charge of emotional processing. This is part of the limbic system, which modulates the response of the organism, producing an activation of the sympathetic branch and predisposing it to fight or flee.
In this sense, combat is one of the most extreme and stressful situations that a human organism can experience because combatants have to deal with a large number of stimuli that can compromise their physical integrity. Researchers have highlighted the presence of this fight and flight reflex in various combat contexts (parachute jump, subsoil combat, symmetric and asymmetric combat), as well as in different units and brigades with different experience and previous training, being, therefore, the activation of this system something common and inherent in military combat situations.
The activation of this system has a direct effect on the psychophysiological response of the military combatant. We observe physiological alterations such as increases in heart rate disproportionate to the effort carried out, overactivation of the sympathetic branch, exacerbated metabolic response in terms of the concentration of lactate and creatine phosphokinase referred, and high levels of cortical activation, evidencing a decrease in information processing and central nervous system fatigue. Likewise, alterations have been reported at the psychological level (alterations in perception, cognition and memory) not only as a chronic effect, but also as an acute one, in response to the combat situation.
All the organic processes previously exposed that happen in combat situation have a direct effect in the processes of acquisition and consolidation of the information. The release of stressful hormones such as glucocorticoids has a direct effect on our central nervous system and higher cognitive processes, interfering with information processing and learning processes or constructs. The release of cortisol –more specifically from corticotropin (which disturbs the process through which the brain collects and stores memories) as a consequence of the anxiogenic response in this context– produces a disintegration of the dendritic spines of these neurons. This limits the ability to collect and store memories through synapses, as well as a reduction in declarative memory; and in the long term, death of the brain cells of the hippocampus, elemental for the formation and consolidation of memories. Likewise, some authors have reported how veteran soldiers present significant morphological attenuations in the volume of the hippocampus, a fact highly marked by the presence of disorders such as post-traumatic stress. In this line, chronic exposure to highly stressful situations, continuously and over long periods of time, impairs communication between neurons in the region of the brain corresponding to learning and memory, which explains the fragile state of psychological health of veteran combatants.
At the research level, after an acute exposure to a combat situation, alterations have been reported in the perception of the body and the perceived effort, in which the soldier is not truly aware of the burden of physical effort involved in combat, a fact that could seriously compromise his physical integrity. Also, alterations of the environment that the obvious soldier, as it has been possible to verify after an analysis of postsimulation by means of questionnaires posmission and analysis of battle-cam. These would be certain elements that could be fundamental to the mission. In one of the studies, a soldier was asked about how many times he had fired. He didn’t have an answer. But after being compared with the data from the vision camera that the soldier was carrying, it was verified that he had fired 22 times with 16 hits. Clinically it would be defined as a total retrograde amnesia of the maneuver carried out, a fact closely related to the cortical overactivation and the sympathetic system
Likewise, in another study in which experienced civilians and soldiers participated in a combat simulation where ethnic cleansing was represented with great fidelity, civilians (war reporters) ignored a large number of elements of the environment, vital to the preparation of the press release. Likewise, the traumatic event (beheading of an insurgent), provoked in the journalists one more case of retrograde amnesia since none of them remembered this event until after 72 hours. Alterations in the passage of time have also been reported. Underground combat simulation studies in low visibility, claustrophobic and narrow conditions, produced an average alteration of 23% in the temporal perception regarding the timing of the mission.
Consequently, the stress perceived by the combatant will have a series of organic and psychological repercussions that will have a negative effect both on his physical integrity and on his health, as well as on the performance of certain tasks or tasks. Because the activation of this fight or flight system is designed to respond to isolated and acute events. Therefore, when the aversive/stressing stimulus chronalizes over time, psychophysiological health problems will show up most clearly. Future research in this area is essential as exposure to these stimuli is continuous in highly stressful professions such as policemen, firefighters and law enforcement. Consequently, knowing the possible variables and interactions in reference to the psychophysiological response in these contexts is vital in order to be able to clearly design action and intervention plans that improve and optimize the psychophysiological response of these groups.
José Francisco Tornero-Aguilera
Professor at the Programa de Doctorado en Actividad Física y Deporte and at the Máster en Actividad Física y Salud
Vicente Javier Clemente-Suárez
Professor at the Grado en Ciencias de la Actividad Física, el Deporte y Fisioterapia and at the International Master in Football Coaching and Management