When considering psychological trauma from an enactive perspective and acknowledging that perception and action are intrinsically linked, the mechanisms described in the previous section and their accompanying symptoms can also be understood as an attempt to control oneself, the environment, and the causes of the TE that pervade both perception and action, whether physically or virtually. Thus, understanding PTSD symptoms as an adaptive response to psychological trauma can inform future treatment development, creating a more holistic approach to PTSD treatment that focuses on empowering patients to regain an SA and control over their environment. In this section, we briefly review PTSD symptoms and how they relate to the SA (Table 1).

Intrusive thoughts and memories as well as vivid re-experiencing, also called flashbacks, and traumatic nightmares are common symptoms in the aftermath of a TE [129,130]. These intrusive symptoms are distressing and make it difficult for patients to function in their daily life. Some patients with PTSD may have a tendency to replay the TE mentally in an obsessive-compulsive or addictive fashion, supposedly in an attempt to make sense of it and understand what had happened [131]. Intrusion symptoms can be regarded as a facet of dissociation [104]. Still, the recent findings on the activation of brain structures and neural circuits pointed out in the previous part, which would make PTSD and D-PTSD different entities, oppose this interpretation [114,132]. Intrusion symptoms have recently been analyzed from a Bayesian perspective, where the TE perceptual hypothesis gains a very high prior due to its life-threatening significance and is reselected independently of the actual sensory input [133]. From an enactive perspective, this can be understood as a way for the individual to try to regain some control over the TE to make it less distressing. Indeed, instructions to freely express intrusive thoughts led to a decrease in intrusive sexual assault thoughts over time, while suppressing them led to an automatic rebound in intrusive thoughts over time [134].

In addition to intrusive cognitions, repetitive behaviors, such as re-exposing oneself to potentially traumatic situations, are often seen in individuals with PTSD and can be a way for them to try to regain their SA. This can be observed in patients with C-PTSD and premorbid personality disorders, who may engage in risky or self-destructive behaviors [135]. Perhaps one of the most striking examples of repetition syndrome would be patterns of hypersexuality in children who have been victims of sexual abuse [136]. Patients are at risk of repeated harm, either self-inflicted or at the hands of others, adopting self-destructive behaviors [136] or repeated exposure to violence (suicide attempts, self-mutilation, military enlistment, development of substance use disorders, risky sexual behavior, and inability to give consent for sexual intercourse leading to exposure to rape situations), which can be seen as a tentative to attribute to our own action the destruction of oneself experienced during the original TE [121]. The climax of this viewpoint is found in the classical example of survivors becoming executioners (children who experienced abuse, child soldiers, etc) after a phase of repetitive behaviors such as engaging in plays or reenactments, often seen in childhood traumas [137]. Freud [138] famously discussed the idea of individuals using objects or activities to regain a sense of control over their environment. He gave the example of a baby playing with a toy that represents his mother to feel like he has control over the situation and soothe his distress. This idea was later developed by Winnicott [139] into the concept of transitional objects, used by children to cope with the loss of the subjective omnipotence over their environment, deriving from the caretaker’s attention to the child’s need, a frustration that can be related to the one experienced during a TE. Separation (ie, autonomy) from the parents accompanies the rise of the SA in childhood, as the sum of the attempts to compensate for the loss results in the gained ability to be alone. Intrusive cognitions and repetitive behaviors are thus common symptoms observed in individuals with PTSD, which can be seen as attempts to regain an SA and cope with the psychological trauma. However, these symptoms can also lead to repeated harm or victimization, making it crucial for therapists to develop treatment strategies that focus on restoring the SA while addressing the underlying causes of these symptoms.

The second category of PTSD symptoms is avoidance behaviors [140], that is, the active avoidance of thoughts, feelings, or external reminders of the TE. This can include avoiding certain places, people, or activities that may trigger memories of the event [141]. As patients have lost their SA over what triggers their flashbacks, the best way to control their occurrence is simply to avoid the stimulation. Here again, this might be understood as a displacement of the cause of the TE, where patients assume they can take responsibility for generating these sensory signals that largely surpassed their perception and action capabilities. One possible explanation for avoidance symptoms in PTSD is, therefore, that they may be an attempt by patients to regain their SA over their environment. For example, patients with PTSD due to a car accident may avoid driving, as driving may trigger memories of the TE [142].

An alternative explanation for avoidance symptoms in PTSD is that they serve as a means of self-protection, aiming to minimize the risk and vulnerability to risk. Social cognition impairment is commonly observed in PTSD [143]. By avoiding social situations, patients can shield themselves from re-experiencing the TE and encountering additional distress. Another instance is postdisaster PTSD, which is more likely to occur if the disaster originates from human actions as opposed to natural causes [144,145]. This underscores the greater psychological impact of interpersonal trauma, as it is perceived as potentially controllable, thus amplifying the distress. Patients may instinctively seek to regain the SA by avoiding situations associated with interpersonal trauma when addressing PTSD symptoms.

It should be noted that substance use is often seen as a form of avoidance in individuals with PTSD who may use drugs or alcohol as a way to numb or suppress their traumatic memories [146] or to escape from the difficult emotions that can accompany these memories. For example, self-reported PTSD is associated with increased use of 3,4-Methylenedioxymethamphetamine (MDMA) in adolescents with substance use disorders [147], and substance abuse is widespread in victims of childhood sexual abuse [148]. In addition to numbing their emotions, substance use can also be a way for individuals with PTSD to avoid trauma reminders (people, places, or situations).

Negative cognitions are thoughts and beliefs about oneself, others, and the world that are negatively distorted and not based on reality. They include beliefs that one is to blame for the TE, that the world is dangerous and unpredictable, and that one is not safe. They also include decreased interest in activities, negative emotions, and the feeling of being isolated. They may be a way of coping with the loss of the SA. Patients with PTSD often believe they are to blame (ie, the feeling of guilt) for the TE, perhaps as this belief provides them with a (virtual) sense of control over the situation. By experiencing guilt and self-blaming, they make sense of the event and feel like they have some SA over it—“I am responsible for exposing myself to the environment that generated the TE” [149].

In addition, negative cognitions in PTSD relate to the prediction of an expected loss of the SA. A TE can cause a person to feel vulnerable and at risk: negative cognitions may be a way of anticipating and preparing for future loss of control. For example, patients with PTSD may believe that the world is dangerous and unpredictable, as this belief helps them to be prepared for potential threats. This culminates with the concept of signal anxiety developed by Freud [150], one of the main defense mechanisms. By expecting the worst, patients are able to feel like they have some control over their environment and can protect themselves from further harm. Klein [151] related trauma negative cognitions to the “depressive position” in the early phase of existence. This preverbal infantile attitude comes with a loss of subjective omnipotence (ie, control) over external objects that coincides with the emergence of emotional valence in infancy: the child becomes aware that objects not only gratify (“good object”) but can also frustrate (“bad object”), generating feelings of guilt and grief and a desire for reparation. This example of “proto-traumas” or “micro-traumas” experienced repeatedly during early childhood lightens what happens when a real TE occurs later in life, altering the sense of control and leading to greater PTSD susceptibility [99,152,153]. These negative thoughts and beliefs may be a way of coping with the distress and vulnerability caused by the TE, but in a vicious cycle, they can also have negative effects on daily life and overall well-being related to an expected loss of the SA, if nothing is done to remedy it.

Patients with PTSD develop a heightened state of awareness, alertness, and physiological arousal to regain a sense of control and SA [154]. This is referred to as hypervigilance [114], characterized by emotional undermodulation, resulting in an increased threat detection and fear learning, and a state of alertness and readiness to respond to these threats [155]. This also includes irritability, difficulty concentrating, sleeping disorders, and an overall sense of feeling on edge. On a sensorimotor level, hypervigilance may manifest as an increased sensitivity to sensory stimuli, such as changes in light or sound, as well as increased physiological arousal, such as increased muscle tension or an elevated heart rate, which is a risk factor for developing PTSD when it immediately follows the TE [156,157]. PTSD is in return a risk factor and shares genetic risk for cardiovascular diseases [158]. By being constantly on guard and ready to respond to potential threats, patients may feel they are able to anticipate and prevent dangerous situations from occurring. This restores the SA that was lost as a result of the TE. Hypervigilance, as an attentional bias toward potential threats, can lead to anxiety and further hypervigilance [155,159]. This can cause the individual to misinterpret ambiguous cues as threats and exaggerate minor threats, as shown by the overactive SN, whose function is to recognize and prioritize stimuli while regulating emotional reactivity [160]. These changes in attention and threat perception can also manifest in the individual’s eye movements [161], leading to an inability to disengage from potential threats. This is referred to in the literature as “oculomotor reflexes” [162]. From a Bayesian inference perspective, dysfunctional SN amounts to aberrant precision control, where precision denotes the confidence placed in prediction errors (mirroring the reliability of the stimulation that causes them) within the hierarchy of information processing, that is, a high precision will favor bottom-up ascending prediction errors, while a low precision will bias perception toward top-down prior beliefs. Interestingly, the SN implies the ACC and insula, which are strongly related to interoception [163]. The dysregulation of bodily signals in psychiatric illnesses may, therefore, offer an important way forward in terms of phenotyping [164,165].

After Winnicott [139], Anzieu [166] developed the concept of “skin-ego,” that is, the presence of a symbolic skin allowing for the creation of psychic and bodily boundaries. In PTSD, this symbolic frontier is blurred or constricted and no longer filters or organizes sensory and perceptual signals as easily. It becomes porous and loses its function as a protective structure between interoceptive cues and cues originating from the external world. This sudden immense vulnerability exacerbates the loss of self-integrity and SO and forces the maintenance of a state of psychic survival with various defensive symptoms involving both temporality and space: agitation, withdrawal, and dissociative symptoms.

The view of peritraumatic dissociation as a protective response can be related to the anthropological interpretation of dissociative experiences with their positive affective valence, with the DMN mainly activated in situations such as daydreaming, hypnotic responses, fatigue, anxiety, drug intoxication, and boredom [167]. In this case, dissociation has a social and discursive meaning rather than being seen as a mechanism. It can thus function adaptively, which depends fundamentally on context [94,168].

By contrast, dissociation interferes with the integration of sensory information and the creation of a coherent sense of self. If dissociative symptoms of PTSD are the reminiscences of peritraumatic dissociation and protect patients against the distress provoked by intrusion symptoms or hyperarousal, they are nevertheless severely debilitating. Patients often complain of the distress related to their dissociative states, which can be transitory or permanent and are associated with high disability. Dissociation can indeed be interpreted literally as the loss of the SA: “if I see myself from an external point of view, thus my body’s actions do not belong to myself” and “if the external world is not real anymore, then I can no longer be an agent in the real world.”

Dissociation can thus at the same time be a loss of the SA and a protective phenomenon against it. There is an ongoing debate on this matter, with the concept of protective dissociation culminating in at-risk professions such as the military or fire service: workers experience deliberate dissociative states [169,170] to gain automatic action and execute tasks more efficiently without being emotionally overwhelmed. Further research is required to thoroughly investigate and clarify this phenomenon. One potential avenue is to distinguish between the passive loss of the SA resulting from external TE and the symptoms actively produced (deliberately or not) by patients as a means to combat passivity (“if it is due to my action or my mind that I lose SA, thus the weight of external events in the loss of SA is reduced”). This includes dissociation or dissociative behaviors (eg, drug use).

GS is a technique that involves using natural body gestures to control and generate sound. It uses sensors to detect the movement of an individual’s body and then translates this movement into sound (Figure 1).

GS allows overcoming VR’s limitations, as it is a screen-free alternative where only the auditory sense is augmented. It enables participant-body-environment coupling, the maintenance of contact with the therapist, and a more individualized virtual environment. It is applicable in case of language barrier, is more acceptable and user-friendly, and provides clinicians with ample opportunities for exploration. However, despite its potential benefits, some challenges might be encountered, such as acceptability. Indeed, patients may refuse to use GS; feel inhibited or startled while using it; and be exposed to various risks, such as allergies to sensors or, in case of improper use, hearing loss due to excessive volume or physical injury from uncontrolled movement. In addition, it is important to exercise caution both in the moment and in selecting sounds according to the way GS is used. For instance, some sounds that might be used for providing a sense of security in some patients could trigger intrusive symptoms in others due to specific traumatic experiences (eg, water sounds for a patient who experienced drowning).

While GS has found applications in various health contexts, such as physical rehabilitation [213] and music therapy [214], its potential in psychiatric illnesses has largely remained untapped. By combining GS with sensorimotor exercises, patients with PTSD could use their bodily movements to generate sounds and manipulate and control virtual objects and environments, creating a more immersive and engaging experience that leaves room for interaction with the therapist. GS could, therefore, emphasize the body and the sensations of movements that are often overlooked in first-line therapies such as prolonged exposure. By directing attention to the body and the physical sensations experienced, GS could assist patients in connecting with their present moment experience and developing a greater SA [193,215]. Indeed, multisensory retroaction can reinforce patients’ sense of control over their symptoms [213]. Importantly, GS can be combined with guided imagery (GI) to provide a personalized experience for patients, allowing them to manipulate, through sensorimotor exercises, the traumatic memories and facilitate their integration. GI is a behavioral mind-body intervention using appropriate scripts and imagination to manipulate representations and enable positive affective and body responses [216,217]. GI uses sensory integration to enhance affective and cognitive retrocontrol over hyperarousal through muscular relaxation and positive mental images. GI has been shown to improve depression, anxiety, and stress [218] and change the meaning of pain [219] and is also widely used in prolonged exposure as well as a self-management intervention to alleviate PTSD symptoms [220], especially hyperarousal. Nevertheless, individuals are not equal in their ability to engage in GI, and its efficacy is correlated with absorption abilities [221] and stays controversial [222]. Our team has experimented with GS and found that the technology could potentially help augment such abilities and thus mind-body interventions. We identified 5 potential applications of the system following the common course of existing therapies.

Functional alterations in brain circuitry identified in patients with PTSD could already be present before the TE and constitute risk factors for developing PTSD [83]. Occasionally, they may exist before PTSD and worsen after the onset of PTSD. Indeed, PTSD has been found to be highly heritable due to epigenetic factors [83,223-226], which means that prior trauma and cumulative life adversity may induce alterations in brain circuitry responsible for vulnerability to PTSD [99,152,153].

Preventing PTSD, for instance, among at-risk populations such as women, refugees, and military and rescue workers [227] involves more than just averting TEs. It means identifying cognitive impairments predisposing for PTSD and enhancing or correcting these impairments. This includes improving cortical and hippocampus retrocontrol abilities, activating the central executive network or DMN, and regulating the SN to maintain threat detection at an optimal level. Ultimately, this entails bolstering the SA before the TE occurs, potentially averting SA failure, peritraumatic dissociation, and thus PTSD later on. GS could be used to assess vulnerability and prepare military and rescue workers before field operations.

In addition, GS could serve as an SA enhancer in the immediate and postimmediate phases following the TE. During the immediate phase, where defusing by talking [228] aims at reintegrating individuals in the present moment with the presence of the other, GS could help mitigate peritraumatic dissociation by amplifying environmental sounds and facilitating reorientation. In the postimmediate phase, during early psychological interventions or debriefing, which may not prevent the onset of PTSD but may improve subsequent adherence to necessary care [229-235], GS could help reduce stress activation by providing soothing sensorimotor environments.

GS could potentially help patients with PTSD to reduce their hyperarousal symptoms. Patients may indeed engage their senses to focus on the present moment. Using personalized sound environments considered secure by patients (eg, water, beach, and fireplace) can help reduce physiological arousal (eg, elevated heart rate or increased muscle tension). Furthermore, by letting patients control with their body movements the volume of the sounds produced by the device, it may help them acquire the ability to filter the external sensory signals whose input is distorted in PTSD with hypervigilance.

By strengthening proprioception and sensory modality with movement, patients can learn to tame the external world, the one that has betrayed or shattered. GS would thus help construct coherence and new congruences in multisensory processing: sorting, filtering, or hierarchization. Enhancing the patient’s self with an auditory signal, a vibrational charge to movement from the environment, offers the patient the opportunity to reverse defensive modes of withdrawal: it awakens curiosity and momentarily diverts anxious rumination about the external world. The environment becomes a facilitator of action, contributing to the reshaping of mental images and the reinforcement of motor planning. The patient actively participates, seeking to recombine the missing pattern in psychological trauma, creating sensory coherence and ideas through action. This synergistic process involving the postural system and the psychomotor feedback allowed by GS nourishes past sensorimotor experiences while updating new ones. Patients are placed in a position to synchronize with the world and derive pleasure from this tuning.

Importantly, GS could help patients with PTSD to reduce dissociation symptoms. Sensorimotor therapy facilitates the reconstruction of the body schema to align with functional reality. Patients are guided to inhabit their body and reshape their representations within a somatic reality. Through the pursuit of body wholeness and conscious work on muscle tone, the therapist contributes to this aim. Dance, slow movement in dynamic relaxation, and postural work (eg, Qi gong and yoga), through the antagonistic interplay of tension and relaxation, create a dynamic musculo-psychological synergy. Tonus is initially a function of dialogue with the world. Among the wide variety of sensorimotor or body-oriented therapies, GS could be combined with dance movement therapy (DMT) for instance. DMT has demonstrated its effectiveness in treating PTSD [236,237]. It calls for the awakening of supportive responses: a confident relationship with support generates a repelling force. Attention is focused on coordination and responses to orientation, alignment, and balance in rhythm. DMT is a therapeutic mediation that allows for the revisiting of early tuning connections; engages in the quality of gaze, joint attention, and gesturing; and addresses support, verticalization, and initial connections. Combined with GS, patients may be able to control with their body various elements (eg, rhythm, timbre, melody, harmony, and dynamics) of the music to which they are dancing and position themselves in a realm beneath language: the reality of music interplaying with movement that spatializes and shifts. This dual modality is a prelude to the transformation of psychological trauma through somato-psychological adjustments, when the body becomes “the thought-thinking apparatus” [238]. In essence, GS combined with sensorimotor therapies would work toward the generation of new body images, reinforcing tonic regulation, self-esteem, and primary narcissism and finally restoring not only proprioceptive feelings enabling patients to reintegrate their body, as well as a sense of contact to the ground (ie, reducing depersonalization), but also the SA over incoming sensory signals from external objects (ie, reducing derealization).

GS involving sounds related to triggers of intrusive symptoms or to the TE itself may help patients with PTSD to engage with their environment in a more active, meaningful way than mere passive exposure, controlling intrusive symptoms and overcoming avoidance behaviors. Gradually, they would expose themselves to triggers that they are avoiding, gaining progressively the ability to control them. GS may indeed let the patient control the level of gradual exposure to TE triggers by themself. As in prolonged exposure, the uncontrollability of intrusion symptoms or triggers would then be reduced by the gained ability to control the irruption, intensity, and end of triggers or intrusion symptoms through body-environment interactions.

Social cognition is disturbed in PTSD [143], especially social perception, affective theory of mind, affective empathy, and social interactions. Of note, social cognition is more altered if the TE is interpersonal (ie, originating from human actions) than not interpersonal [239]. Patients with PTSD exhibit an overactive SN, which has a crucial function in affective empathy, which in turn also relates to a higher sensitivity to stress [240] or the negative social impact [241]. The potential higher affective empathy may probably explain the increasing attention on social rehabilitation in PTSD treatment, such as communication training, group therapies, or community programs [242]. Indeed, social rehabilitation favors the sense of belonging, just as collective commemorations of disruptive events are perceived useful by victims and help rebuild social links [243].

Sensorimotor group therapies have recently been found to be effective in treating C-PTSD [244,245]. Just as GS would help restore localization and a sense of contact with the ground and external objects by increasing the sensorimotor afferences, it could also restore the sense of contact with other individuals and help in the process of mourning. The involvement of the body and the sensorimotor pleasures that reconstruct and reshape body schemas enhance bodily sensations of gathering or synchronization. This, in turn, boosts the effective connectivity of the mirror neuron system, which is crucial for social cognition [246].