Anomalous Bodily Maps of Emotions in Schizophrenia

Abstract

Objective Embodied emotions arise from interoceptive and somatosensory processes, and are essential to the development of a stable sense of self. Emotional embodiment is therefore inherently interwoven with our sense of bodily self-awareness, and allows us to navigate complex social situations. Given that the core feature of schizophrenia (SZ) is characterized by the presence of bodily self-disturbances and social-emotional deficits, we hypothesized that embodiment of emotion would be disrupted in SZ. Method Twenty-six medicated individuals with SZ and 26 demographically matched controls used a computerized topographical mapping tool (“EmBODY”) to indicate on a body outline where they felt bodily sensations while experiencing an emotion. There were 13 different emotions plus a neutral state. The resulting bodily maps of emotions were quantitatively compared between groups using linear discriminant analysis and similarity scores. Results Bodily maps of emotions were anomalous in SZ as indicated by indistinguishable maps across different emotions. Relative to the control group, patients reported less discrete and less clear bodily sensations across emotions. In particular, bodily maps for low-arousal emotions were atypical in comparison with healthy controls. Conclusions Anomalous and undifferentiated mapping of embodied emotions in SZ could lead to deficits in linking bodily sensations to conceptual categories of emotions. Disrupted emotional embodiment could also contribute to poor social functioning. Abnormal bodily sensations of emotions might therefore be a promising target for future psychosocial interventions.

Body-maps of emotions in bilateral vestibulopathy

“…Experiments with the emBODY tool in large samples of healthy participants revealed that different emotions are consistently associated with different bodymaps [9,10]. These body-maps of emotions are consistent across different cultures [9], developed between age 6 and 17 to become spatially specific [11], and they appear to be altered in clinical conditions [12].…”

“…Second, we analyzed the number of colored pixels corresponding to activation and deactivation for each emotional word per participant [12] (Fig. 1c).…”

“…Pre-processing and statistical analyses were adapted from Refs. [9,12]. Silhouettes contained 50,364 pixels for which the color intensity was coded from 0 to 100.…”

“…This suggests that BVP patients may be less aware of their interoceptive signals, i.e., the signals from the gastro-intestinal tract, blood vessels, kidneys, heart, etc., when presented with different emotional words. The emBODY tool revealed abnormal, less clear, and less differentiated body-maps of emotions in patients with schizophrenia [12], known to have lower interoceptive accuracy and higher disembodiment than healthy controls [17]. There is evidence that anosmia [18] and sensorimotor deafferentation in spinal cord injury [19] can decrease interoceptive accuracy.…”

Interoceptive Functioning in Schizophrenia and Schizotypy

“…In schizophrenia, this basic sense of the bodily self is disrupted (Bleuler, 1911;Sass and Parnas 2003). Narratives of aberrant self experiences (e.g., Kean 2009;Saks, 2007) are supported by contemporary empirical evidence documenting anomalous body ownership, agency, and emotional embodiment in this population (Hur et al, 2014;Raballo et al, 2021;Thakkar et al, 2011;Torregrossa et al, 2019). Importantly, such anomalous self-experiences predate schizophrenia onset (Nelson et al, 2012) and may lead to social impairments and disconnection (Michael and Park, 2016).…”