Passive Remote Monitoring of Psychophysiological Arousal. Another key barrier to the predictive accuracy of existing risk assessments is their inability to assess the psychophysiological arousal associated with aggression. Neurophysiological theories of aggression suggest that it is driven in part by autonomic nervous system dysregulation (Xxxxx, 2014), reflecting an imbalance between ‘top-down’ control processes and ‘bottom-up’ drives associated with structures of the limbic system (Xxxxxx, 2008) (see Figure 1). This dysregulation can be inferred through changes in electrodermal activity and heart rate variability (HRV; Xxxxx & Xxxxxxx, 2004), indices of sympathetic and parasympathetic nervous system activity. Figure 1 A balance between top-down and bottom-up drives resulting in behavioural inhibition and no aggression (top) versus an overly strong bottom-up drive and inhibited top- down control resulting in aggression (bottom) - adapted from Xxxxx (2014) Previous research has reported an association between both psychophysiological hypoarousal and hyperarousal and aggression (Xxxxxx & Xxxxx, 2000). Psychophysiological under-arousal is thought to underly predatory and planned forms of aggression and is typically reflected among individuals with DPD and psychopathic traits. For example, one dubiously ethical experimental technique is to induce stress among forensic mental health service users, and one study using this technique reported significantly diminished psychophysiological arousal among service users with DPD and psychopathic traits compared to other clinical groups and non-affected controls (Lobbestael et al., 2009). This pattern of hypoarousal is thought to reflect a diminished threat response (Xxxxx et al., 2004; Xxxxxx et al., 2009). Psychophysiological hyperarousal is believed to reflect reactive and impulsive forms of aggression (Xxxxxx et al., 2010), evidenced by elevated electrodermal activity (Xxxxxxxxx et al., 2019; Xxxxxx-Xxxxx et al., 2017) and reduced HRV (Xxxxxxx et al., 2019). Previous research has been unable to capture changes in sympathetic and parasympathetic nervous activity in participants’ everyday life, due to the costs and limited portability of the monitoring equipment. However, advances in passive remote monitoring (e.g. wearable sensors) now enables these parameters to be monitored continuously, with minimal intrusion in participants’ daily activities. There is developing interest in the role that passive remote monitoring technology could play in forensic mental health services...
