Self /other recognition and distinction in adolescents’ with Anorexia Nervosa: a double mirror paradigm

Abstract

Background The body plays a major role in defining, understanding and treating anorexia nervosa. Much research has focused on patients' physical body representation or their own perceived body, but without explicit reference to their relationship to others and the social processes involved. Yet, there are a several arguments supporting impairments in interpersonal relationships in these patients. Notably, some evidence suggests that self/other distinction (SOD), the ability to distinguish one's own body, actions and mental representations from those of others could be impaired in anorexia. But research remains scarce in this area. Material and Methods A single-centre, prospective pilot study was conducted to investigate, for the first time, self-recognition and SOD in seven adolescents with anorexia nervosa (AN) compared with matched healthy controls (HCs) using the "Alter Ego"TM double mirror paradigm. This innovative device allows the progressive morphing of one’s own face to that of another and vice versa between two subjects that interact on opposite sides of the device. Two judgement criteria were used: 1) M1: the threshold at which subjects start to recognize their own face during other-to-self morphing, and 2) M2: the threshold at which subjects start to recognize the other’s face during self-to-other morphing. In a second part, the same procedure was reproduced under 5 different sensorimotor conditions to examine their effects on self-recognition and SOD. Results The results showed that the participants with AN exhibited earlier self-recognition in the other-to-self sequence and delayed other-recognition in the self-to-other sequence. Furthermore, in contrast with that of HCs, the critical threshold for switching between self and other varied with the direction of morphing in AN participants. Finally, when anorexic subjects were seated in a chair with the backrest and footrest touching their body, the self-recognition threshold (M1) increased significantly, approaching that of controls. Conclusions Although additional research is needed to replicate the results of this preliminary study, it revealed the first behavioural evidence of altered SOD in individuals with AN through an embodied, semiecological face-recognition paradigm. Relationships between body perception and alterations in interpersonal relationships are discussed as well as new research and therapeutic perspectives are presented.

Your body, my experience: A systematic review of embodiment illusions as a function of and method to improve body image disturbance

“…The main characteristics and results of the 32 included studies are summarised in Appendix C. Studies were published between the years 2006 and 2022 in the English language. Thirty studies were published in peer-reviewed journals and two were from the grey literature (Lavenne-Collot et al, 2022; Wolf et al, 2021). Sample sizes ranged from six to 167, with a median of 36.…”

“…Fourteen studies examined differences in susceptibility to embodiment illusions as a function of BID. Nine (64.29%) reported significantly greater susceptibility amongst those with high (relative to low/no) BID on at least one outcome measure (generally involving medium or large-sized effects; Eshkevari et al, 2012; 2014; Kaplan et al, 2014; Keizer et al, 2014; 2016; Lavenne-Collot et al, 2022; Metral et al, 2017; Mussap & Salton, 2006; Zopf et al, 2016). Three (21.43%) studies reported reduced susceptibility among those with high (relative to low/no) BID on at least one measure, involving medium and large effects (Carey & Preston, 2019; Porras-Garcia et al, 2020; Tagini et al, 2020).…”

“…Clinical conditions and symptoms. Of the 14 studies, six compared individuals with anorexia nervosa to healthy controls: of these, four (66.67%) reported greater susceptibility in the anorexia sample (generally involving medium or large effects; Keizer et al, 2014; 2016; Lavenne-Collot et al, 2022; Zopf et al, 2016); one reported greater susceptibility among the healthy control group (with a medium effect; Porras-Garcia et al, 2020); and the remaining study found no significant difference (with a not discernible small-sized effect; Provenzano et al, 2019). Three studies compared a mixed ED group to healthy controls: two (66.67%) reported greater susceptibility among the ED group, with small to large-sized effects (Eshkevari et al, 2012; 2014).…”

“…Embodiment illusion paradigm. Of the 14 studies, nine employed a real-world paradigm (RHI [ n = 8]; double-mirror paradigm [ n = 1]), of which, eight (88.89%) reported greater susceptibility for those with high (relative to low/no) BID (generally involving medium to large-sized effects; Eshkevari et al, 2012; 2014; Kaplan et al, 2014; Keizer et al, 2014; Lavenne-Collot et al, 2022; Metral et al, 2017; Mussap & Salton, 2006; Zopf et al, 2016). The remaining study reported reduced susceptibility among those with high BID (medium-sized effect; Carey & Preston, 2019).…”

“…Another study observed a significant medium-sized effect only in synchronous conditions, though noting a non-significant small-sized effect for asynchronous conditions (Keizer et al, 2014). The remaining three studies failed to include an asynchronous condition (Mussap & Salton, 2006), compare the two during analyses (Metral et al, 2017), or assess synchrony (i.e., mere observation of another body part with no stimulation; Lavenne-Collot et al, 2022).…”