Involvement of physiological reactivity and interoception in emotional experience after a traumatic brain injury

Emotional experience is based, among other factors, on physiological reactivity (PR) and the awareness of this reactivity corresponding to interoception. After a traumatic brain injury (TBI), patients exhibit reduced PR and interoception, raising questions about the integrity of their emotional experience.

To examine this issue, 26 men with moderate to severe TBI (age: 37 ± 11) and 26 healthy male controls (age: 35 ± 14) watched emotional films (amusement, tenderness, anger, disgust). PR was measured via electrodermal activity (EDA) and heart rate variability (HRV). After each film, an emotional evaluation was completed using the Differential Emotional Scale (DES). Interoception was measured through a heartbeat counting (HBC) task and the Multidimensional Assessment of Interoceptive Awareness (MAIA) questionnaire.

Compared to controls, TBI participants scored lower on the MAIA Emotional Awareness and Noticing subscales, and exhibited lower EDA and HRV during the anger and tenderness films. However, emotional evaluations and HBC task scores were similar between groups. Positive correlations were found between emotional evaluation and the MAIA scale.

These results suggest a dissociation between emotional experience and PR after TBI and decreased interoceptive sensitivity. Since interoception links PR and emotional experience, exploring the impact of reduced interoception on this dissociation could improve our understanding of post-TBI emotional functioning.