Embodied Precision : Intranasal Oxytocin Modulates Multisensory Integration

© 2018 Massachusetts Institute of Technology.Multisensory integration processes are fundamental to our sense of self as embodied beings. Bodily illusions, such as the rubber hand illusion (RHI) and the size-weight illusion (SWI), allow us to investigate how the brain resolves conflicting multisensory evidence during perceptual inference in relation to different facets of body representation. In the RHI, synchronous tactile stimulation of a participant's hidden hand and a visible rubber hand creates illusory body ownership; in the SWI, the perceived size of the body can modulate the estimated weight of external objects. According to Bayesian models, such illusions arise as an attempt to explain the causes of multisensory perception and may reflect the attenuation of somatosensory precision, which is required to resolve perceptual hypotheses about conflicting multisensory input. Recent hypotheses propose that the precision of sensorimotor representations is determined by modulators of synaptic gain, like dopamine, acetylcholine, and oxytocin. However, these neuromodulatory hypotheses have not been tested in the context of embodied multisensory integration. The present, double-blind, placebo-controlled, crossover study ( N = 41 healthy volunteers) aimed to investigate the effect of intranasal oxytocin (IN-OT) on multisensory integration processes, tested by means of the RHI and the SWI. Results showed that IN-OT enhanced the subjective feeling of ownership in the RHI, only when synchronous tactile stimulation was involved. Furthermore, IN-OT increased an embodied version of the SWI (quantified as estimation error during a weight estimation task). These findings suggest that oxytocin might modulate processes of visuotactile multisensory integration by increasing the precision of top-down signals against bottom-up sensory input.Peer reviewedFinal Accepted Versio

The effect of pre-treatment psychoeducation on eating disorder pathology among patients with anorexia nervosa and bulimia nervosa

Pre-treatment psychoeducation can be effective for bulimic groups, but little is known about its effect on patients with anorexia nervosa. This study investigated the impact of a pre-treatment psychoeducational intervention on outpatients with diagnoses of full or atypical anorexia nervosa (N = 54) or bulimia nervosa/atypical eating disorder at a normal weight (N = 43). Each attended a four-session psychoeducational group whilst awaiting outpatient treatment. They completed measures of eating and personality disorder pathology pre-intervention, repeating the measures of eating pathology post-intervention. Effectiveness was tested for each diagnostic group using intention-to-treat analyses. Results confirm that such psychoeducational groups reduce unhealthy eating attitudes among bulimic patients, regardless of initial levels of eating and personality pathology. In contrast, the groups were not effective for anorexia nervosa sufferers. Such groups should be considered routinely during waiting periods for bulimia nervosa treatment, but further research is needed to determine how to help anorexia nervosa patients at this stage

The classification of bulimic eating disorders: a community-based cluster analysis study

Published online by Cambridge University Press 09 Jul 2009There is controversy over how best to classify eating disorders in which there is recurrent binge eating. Many patients with recurrent binge eating do not meet diagnostic criteria for either of the two established eating disorders, anorexia nervosa or bulimia nervosa. The present study was designed to derive an empirically based, and clinically meaningful, diagnostic scheme by identifying subgroups from among those with recurrent binge eating, testing the validity of these subgroups and comparing their predictive validity with that of the DSM-IV scheme. A general population sample of 250 young women with recurrent binge eating was recruited using a two-stage design. Four subgroups among the sample were identified using a Ward's cluster analysis. The first subgroup had either objective or subjective bulimic episodes and vomiting or laxative misuse; the second had objective bulimic episodes and low levels of vomiting or laxative misuse; the third had subjective bulimic episodes and low levels of vomiting or laxative misuse; and the fourth was heterogeneous in character. This cluster solution was robust to replication. It had good descriptive and predictive validity and partial construct validity. The results support the concept of bulimia nervosa and its division into purging and non-purging subtypes. They also suggest a possible new binge eating syndrome. Binge eating disorder, listed as an example of Eating Disorder Not Otherwise Specified within DSM-IV, did not emerge from the cluster analysis.P. J. Hay, C. G. Fairburn and H. A. Dol

The brief (seven-item) eating disorder examination‐questionnaire: evaluation of a non-nested version in men and women

Objective: Several recent studies have examined the psychometric properties of brief measures of eating disorder attitudes based on the Eating Disorder Examination Questionnaire (EDE-Q). A seven-item version (the EDE-Q7) has been proposed but, as yet, has only been investigated by looking at the items when presented as part of the longer EDE-Q (i.e., as a nested version). The current study presented the EDE-Q7 as a standalone instrument and examined factor structure fit and measurement invariance across male and female genders. Methods: University students (244 women; 155 men; 1 did not identify with either gender) completed questionnaires as part of two independent studies. All individuals completed the EDE-Q7 and measures of eating disorder behaviours. In a mixed-gender subsample (n = 286), measures of depression and eating disorder-specific quality of life were also included. Confirmatory factor analysis of the EDE-Q7 was conducted on males and females independently, in addition to estimates of internal consistency reliability and validity. Measurement invariance was assessed through multigroup confirmatory factor analysis. Results: The EDE-Q7 demonstrated good internal consistency and findings supported measurement invariance by gender. In a mixed-gender subsample, the measure showed positive associations with depression and both eating disorder behaviours and eating disorder-specific quality of life. Discussion: The present study adds to the literature supporting the psychometric properties of the EDE-Q7, extending this to use of the questionnaire as a standalone instrument. Measurement invariance suggests that the measure may be appropriate for college-age men and women, although future studies should establish psychometric properties more fully

Evidence That the Clinical Impairment Assessment (CIA) Subscales Should Not Be Scored: Bifactor Modelling, Reliability, and Validity in Clinical and Community Samples

Aim: The Clinical Impairment Assessment (CIA 3.0) is the most widely used instrument assessing psychosocial impairment secondary to eating disorder symptoms. However, there is conflicting advice regarding the dimensionality and optimal method of scoring the CIA. We sought to resolve this confusion by conducting a comprehensive factor analytic study of the CIA in a community sample (N = 301) and clinical sample comprising patients with a diagnosed eating disorder (N = 209). Convergent and discriminant validity were also assessed. Method: The CIA and measures of eating disorder symptoms were administered to both samples. Results: Factor analyses indicated there is a general impairment factor underlying all items on the CIA that is reliably measured by the CIA Global score. CIA Global demonstrated good convergent and discriminant validity. Conclusions: CIA Global is a reliable and valid measure of psychosocial impairment secondary to eating disorder symptoms; however, subscale scores should not be computed

Changes in the sense of agency : Implications for the psychotherapy of bulimia nervosa- A case study

A sense of agency is a transtheoretical concept that increases our understanding of important processes in psychotherapy. Agency can be described in terms of how strongly the person believes that she can have an impact on her problematic experiences and behaviors. In this case study, a patient's sense of agency in relation to symptoms of bulimia nervosa was assessed during 3 years of psychotherapy. Five distinct phases of agency in relation to eating disorder symptoms were identified: A false sense of agency or no agency at all, a weak sense of agency, a nascent sense of agency, a wavering sense of agency, and a strong sense of agency. A better understanding of patient agency can facilitate adapting approaches and methods best suited for the patient's capacity for change throughout treatment.Peer reviewe

A pragmatic effectiveness study of 10-session cognitive behavioural therapy (CBT-T) for eating disorders: Targeting barriers to treatment provision

Objective Ten‐session cognitive behavioural therapy (CBT‐T) for transdiagnostic eating disorders targets several barriers to treatment, including cost, therapist expertise, and lengthy wait lists. Method We used a case series design to investigate the effectiveness of CBT‐T delivered by trainee psychologists in a postgraduate training clinic. Participants were randomly allocated to commence treatment either immediately or after a 4‐week waitlist period. CBT‐T was delivered to 52 patients, by six different trainees under supervision. Measures of eating disorder cognitions and behaviours, quality of life, and general psychopathology were examined in completer and intention‐to‐treat analyses using multilevel modelling. Last observation carried forward was applied for abstinence, remission, and good outcome analyses to aid comparison with prior studies. Results Significant improvements, associated with medium to large effect sizes, were found for eating disorder cognitions, behaviours quality of life, and negative affect from baseline to posttreatment, and at 1‐ and 3‐month follow‐up. Attrition (38.5%) was comparable with other treatment studies. Conclusion Results provide evidence for the effectiveness of CBT‐T delivered by trainee psychologists for transdiagnostic eating disorder patients, thus tackling some important barriers for treatment. Longer follow‐up, randomised controlled trial designs, and moderator analyses will provide more robust evidence about which patients do best with a shorter therapy

Toward an understanding of risk factors for binge-eating disorder in black and white women: A community-based case-control study

This study sought to identify in white women risk factors specific to binge-eating disorder (BED) and for psychiatric disorders in general, and to compare black and white women on risk factors for BED.

Recent advances in psychological therapies for eating disorders

Recent years have seen substantial consolidation and development of the evidence base for psychological therapies for eating disorders. This review summarises the key changes over that time period. Specific forms of cognitive behavioural therapy and family-based treatment have consolidated and extended their positions as treatments of choice despite the development of novel approaches. However, there is still a significant need for further development and testing to improve recovery rates, particularly in anorexia nervosa