Increased anticipatory brain response to pleasant touch in women remitted from bulimia nervosa

Abstract

Bulimia nervosa (BN) is characterized by affective instability and dysregulated behaviors (binge eating, fasting, selfinduced vomiting) that disrupt bodily homeostasis. Mechanisms underlying dysregulation in BN are unclear, although altered reward responsivity, anticipatory processing of environmental cues, and interoception (detection and integration of body-state signals to regulate behavior) have been implicated in BN pathophysiology. We aimed to determine whether BN is associated with ineffectively predicting body state or integrating predicted experience with actual experience by examining neural response to anticipation and experience of affective touch, a pleasant interoceptive stimulus that acts on sensory and emotional systems to guide behavior. During fMRI, we administered soft strokes to the palm and forearm in women remitted from BN (RBN; N = 23) and control women (CW; N = 25). A Group (RBN/CW) × Condition (anticipation/touch) interaction was found in the right dorsal caudate; both CW and RBN had increased activation during touch compared with anticipation, with RBN demonstrating marginally greater anticipatory response than CW. For RBN, those individuals who showed greater anticipatory response in the dorsal caudate also reported higher levels of harm avoidance. RBN individuals relative to CW showed greater activation in left putamen and insula during the anticipation but not when experiencing an affective touch. This increase during anticipation rather than the actual experience of the affective touch is consistent with a top-down preparatory process which is associated with harm avoidance and is similar to what has been observed in anxious individuals. This aberrant signal integration could disrupt feedback processing, serving to maintain disordered behavior.

State-specific alterations in the neural computations underlying inhibitory control in women remitted from bulimia nervosa

“…We studied participants in remission from bulimia nervosa to avoid the potentially confounding effects of electrolyte disturbances or recent extreme and symptom-related fluctuations in metabolic state in currently symptomatic individuals. Despite symptom remission, our prior work has detected altered neural responses among women with a history of bulimia nervosa [18][19][20][21].…”

Brain mechanisms for processing caress-like touch in skin-picking disorder

“…For example, in the National Institute of Mental Health's Research Domain Criteria [RDoC] framework, these aspects appear to be either absent or underdeveloped. This is surprising since a multitude of research findings point to the presence of alterations in the processing of CT-optimal (affective) touch in various mental disorders, including diagnoses such as autism, autism spectrum disorders, eating disorders, and borderline personality disorder [ 10 – 12 , 37 ]. Deficits in affective-touch processing are correlated with reduced buffering of stress symptoms [ 38 ], disorganized attachment style [ 39 ], and reduced psychological well-being [ 40 ].…”

Eating disorders: Anorexia nervosa, bulimia nervosa, and binge-eating disorder.

“…The insula is a hub for interoception, and accumulating evidence suggests disturbances in anterior and middorsal insula function in ill and remitted individual with AN (Bischoff-Grethe et al, 2018;Kerr et al, 2016;Wagner et al, 2008). Individuals remitted from AN have also demonstrated a mismatch between insula and corticolimbic response to anticipation and receipt of pleasant touch (anticipation < receipt; Bischoff-Grethe et al, 2018), prolonged aversive breathing restriction (anticipation < receipt; Berner, Simmons, et al, 2018), and thermal heat pain (anticipation > receipt; compared with HC, whereas individuals remitted from BN demonstrate greater anticipatory response to touch (Wierenga et al, 2020) and aversive breathing (Berner, Simmons, et al, 2019), with no difference in receipt. The observed mismatch between subjective experiences and objective brain response in EDs points to abnormal integration and, possibly, disconnection between reported, expected, and actual interoceptive states (Khalsa et al, 2015), although further work is needed to replicate these findings.…”