زبان پریشی جسمانی: عدم تطابق بدن با احساس واکنش استرس اتونوم در اختلالات فکری و روانی

Background Although one of the main characteristics of psychopaths is a deficit in emotion, it is unknown whether they show a fundamental impairment in appropriately recognizing their own body sensations during an emotion-inducing task. Method Skin conductance and heart rate were recorded in 138 males during a social stressor together with subjective reports of body sensations. Psychopathic traits were assessed using the Psychopathy Checklist-Revised (PCL-R) 2nd edition (Hare, 2003). Results Nonpsychopathic controls who reported higher body sensations showed higher heart rate reactivity, but this verbal-autonomic consistency was not found in psychopathic individuals. This mind–body disconnection is particularly associated with the interpersonal-affective factor of psychopathy. Conclusions Findings are the first to document this body sensation–autonomic mismatch in psychopaths, and suggest that somatic aphasia – the inaccurate identification and recognition of one's own somatic states – may partly underlie the interpersonal-affective features of psychopathy.

Psychopathic individuals are characterized by a constellation of traits, including interpersonal-affective (e.g., superficial charm, manipulativeness, lack of affect and emotion) and antisocial features (e.g., impulsivity and aggression (Hare, 2003)). One prominent theoretical perspective of the underlying neurobiological basis of psychopathy is the somatic marker hypothesis (Damasio, 1994), which proposes that appropriate autonomic functioning is critical to experiencing emotional states that guide prosocial behavior and good decision making. It is assumed that emotions associated with previous experiences provide dispositional or visceral markers that function as alarm signals, alerting the individual to the potential negative outcome of a certain action. This somatic marker has been termed as “an unpleasant gut feeling” (Damasio, 1994, p. 173) which includes both visceral and nonvisceral sensations in response to external stimuli, and which are associated with both positive and negative emotional states. Damage to the ventromedial prefrontal cortex and other structures involved in the representation and regulation of body states (including amygdala, insula, somatosensory cortex, cingulate, basal ganglia and brain-stem nuclei) has been argued to result in an inability to experience this “gut feeling” which in turn may predispose to psychopathic and antisocial behavior (Bechara et al., 1999). There has been some support for the somatic marker hypothesis. For example, using the Iowa Gambling Task, several studies have found that while nonpsychopathic individuals learned to avoid “risky” decks, psychopaths made more risky decisions over time, indicating their inability to guide behavior based on somatic markers (Blair et al., 2001, Mitchell et al., 2002 and van Honk et al., 2002). However, some have failed to find this relationship (Blair and Cipolotti, 2000), or have found that the relation is moderated by attention, anxiety, or social status (Blair and Cipolotti, 2000, Gao et al., 2009, Lösel and Schmucker, 2004 and Schmitt et al., 1999). Using a different paradigm, Raine and colleagues (Ishikawa et al., 2001 and Raine et al., 2000) have provided additional supporting evidence. Individuals with high antisocial personality traits and psychopathy displayed significantly reduced autonomic reactivity when giving a speech about their personal faults compared to those with low traits, and also showed reduced gray matter in the ventromedial cortex, orbitofrontal cortex, and amygdala (Yang et al., 2005 and Yang et al., 2010). Damasio (2000) suggested that this social stressor is particularly useful for eliciting secondary emotions such as guilt and embarrassment, and that a lack of somatic markers resulted in socially abnormal behavior in psychopaths. Impairments in this cortical–subcortical network may underlie an individual's inability to interpret or label body sensation, which in turn may give rise to risky decision-making in psychopathic individuals (Bechara et al., 1999, Birbaumer et al., 2005, Blair, 2007 and Yang et al., 2010). Despite this body of research, no study has examined whether psychopaths are unaware of their body sensations at the somatic level. It has long been theorized that emotion experiences arise directly from the perception of body changes (e.g., James, 1884). Given that a fundamental emotion deficit is viewed by many as the core feature of psychopathy (Cleckley, 1976 and Patrick, 1994), it could be hypothesized that psychopaths may be relatively less sensitive to their body changes during emotional events, and thus are unable to accurately perceive their somatic reactions, which may then contribute to their affective deficiency. What also appears entirely unexplored is the mismatch or decoupling between objective measures of body responses (autonomic changes), and subjective verbal reports of body changes in psychopaths. Psychopaths describe emotional experiences, albeit in a fashion that is stereotyped and at times wooden ( Cleckley, 1976). For example, studies have shown that although compared to nonpsychopathic controls, psychopathic individuals show autonomic hyporesponsivity including reduced fear-potentiated startle and smaller skin conductance magnitudes, the two groups’ subjective experience to emotional stimuli are rated similar ( Benning et al., 2005, Flor et al., 2002 and Patrick et al., 1993). Furthermore, these psychophysiological deficits are often attributed to the interpersonal-affective factor of psychopathy ( Patrick, 2007). Given that psychopaths are characterized by emotional deficits, it is possible that they are describing emotions that they think they should feel based on exteroceptive cues, but do not consciously experience. The expectation is that normal individuals may be relatively accurate in perceiving and interpreting their body changes; if they show an objective autonomic increase to a social stressor, they should be able to verbally report corresponding body sensations. In contrast, if there is a disruption in the appropriate sensation of body reactions to a stressor in psychopaths, one would expect somatic aphasia – a mismatch between the subjective report and objective autonomic measures of their body sensations. This study attempts to address this issue by measuring skin conductance and heart rate reactivity during a social stressor in a community sample. All participants were recruited from temporary employment agencies and psychopathic traits were assessed using the PCL-R (Hare, 2003). It is hypothesized that in a social stressor: (1) psychopathic and nonpsychopathic controls will show similar verbal reports of body sensations experienced, and (2) nonpsychopathic controls who report high body sensation will exhibit high autonomic responses, whereas this consistency would not be observed in psychopaths. Finally, we aim to explore which of the two factors of psychopathy, i.e. interpersonal-affective and antisocial behavior, will be particularly associated with the mismatch between autonomic measure and verbal reports of body sensations.