Treatment of Post-traumatic Stress Disorder by Exposure Psychotherapy in Augmented Imagination by Vocal Feedback : Acceptability Study
Treatment of Post-traumatic Stress Disorder by Exposure Psychotherapy in Augmented Imagination by Vocal Feedback : Acceptability Study
We now have many pharmacological and psychotherapeutic treatments for patients suffering from Post Traumatic Stress Disorder (PTSD), including cognitive and behavioral therapy (CBT) by reactivation of traumatic memories. Despite remarkable initial efficacy, only one-third of patients treated with CBT show lasting clinical improvement. On the other hand, the associated drop-out rates vary from 17% to 33%, which may be linked to the difficulty of the task, which implies reactivating the traumatic memory (Bradley et al. 2005).
Alternative treatments for PTSD include blocking chemo-facilitated memory reconsolidation with a beta-blocker, propranolol. Briefly, reconsolidation theory posits that a recalled memory becomes unstable again before consolidating again into long-term memory, hence the term "reconsolidation". During this phase of transitory plasticity, the memory can be modulated, in particular its emotional charge. The use of propranolol has shown its benefit during this phase in patients suffering from PTSD (Brunet et al, 2018). However, the use of this facilitated chemo therapy is limited to patients with no contraindication to taking beta-blockers. In this context, a non-medicinal alternative to attenuate the emotional strength of the memory has a therapeutic interest.
One of the ways in which our emotional experience can be modulated is through the perception of our emotional behavior. According to the theory of self-perception (Bem, 1972) individuals become aware or conscious of their attitudes, emotions and other internal states in part by inferring them from the observation of their own behaviors. Thus when individuals produce sounds or facial expressions typical of specific emotions such as joy, sadness or anger, they will tend to experience an emotional state congruent with their vocal or facial production (Hatfield and Hsee, 1995).
Work on the influence of voice perception, in particular, is experiencing a new boom due to technical developments in the fields of acoustic signal processing. In particular, Dr. Aucouturier's team has created a software device to directly modify the emotional tone of speech formulated orally. For example, for "happy" manipulation, the pitch of the voice is changed with a pitch shifting algorithm to make it more positive, the dynamic range of the voice is increased with a compression algorithm to make it more confident, and its spectral content is modified with a high-pass filter to make it brighter. The results of this work (Aucouturier et al. 2016; Rachman et al. 2018; Goupil et al., 2021) showed an emotional vocal feedback effect: the subjective evaluation that participants make of their emotional state after modification by the device goes in the direction of the emotion created by the platform, even though the participants are typically unaware of the operated modulation. The non-detection of the transformation being a necessary condition for observing the effect of VF on the emotional state of the participant.
The rationale of this study is to test the use of a real-time vocal transformation paradigm during exposure therapy by reactivation of traumatic memory in imagination in patients. During this therapy, the patient is asked to read aloud the very detailed script of the traumatic event. We want to test whether manipulating the emotional tone of the patient's voice online, when reading, can have a facilitating impact on the process of reducing the emotional charge associated with the traumatic script. In order to justify the use of the audio headphones as well as the microphone, and to ensure us of the non-detectability of the transformation operated on the voice, we will explain to our patients that this device (hearing his voice in a headphone during the session of re-exposure to a memory) aims to increase immersion. Our main objective will be to assess the acceptability of this augmented form of psychotherapy, and our secondary objectives will be to assess its technical feasibility and provide initial elements to assess its effectiveness. The results will be compared with data from the literature on the usual treatment (imaginary exposure therapy, with or without propranolol according to the indications).
Inclusion Criteria:
Exclusion Criteria: