There is increasing interest in understanding the roles of distorted beliefs about the self, ostensibly unrelated to eating, weight and shape, in eating disorders (EDs), but little is known about their neural correlates. We therefore used functional magnetic resonance imaging to investigate the neural correlates of self-referent emotional processing in EDs. During the scan, unmedicated patients with bulimia nervosa (n = 11) and healthy controls (n = 16) responded to personality words previously found to be related to negative self beliefs in EDs and depression. Rating of the negative personality descriptors resulted in reduced activation in patients compared to controls in parietal, occipital and limbic areas including the amygdala. There was no evidence that reduced activity in patients was secondary to increased cognitive control. Different patterns of neural activation between patients and controls may be the result of either habituation to personally relevant negative self beliefs or of emotional blunting in patients.
Recent developments in cognitive theories for eating disorders (EDs) include a role for distorted beliefs about the self with content ostensibly unconnected to weight, shape or eating (e.g. Cooper et al., 2004 and Waller et al., 2007). The content of self beliefs in EDs is negatively valenced and although its specific content has been elusive, evidence suggests it can be distinguished from that more typical of depression (Cooper and Cowen, 2009 and Fairchild and Cooper, 2010). For example, self loathing beliefs are common in EDs, while beliefs of abandonment and deprivation are more typical of depression (Fairchild & Cooper, 2010). In practice, because of high comorbidity both types of belief are common in EDs (Fairchild & Cooper, 2010). Despite the theoretical importance of negative self beliefs (NSBs), there have been no studies to date investigating the neural correlates of these beliefs in EDs. This information could be useful in understanding the role and mechanisms of negative self beliefs (NSBs) in EDs and in supporting the development of treatment strategies.
Processing information about the self has been associated with increased activation across a network of areas such as the medial prefrontal gyrus (MFG), posterior cingulate and the precuneus (e.g. Fossati et al., 2003, Kelley et al., 2002, Lemogne et al., 2009, Rameson et al., 2010 and Whitfield-Gabrieli et al., 2011). For example, asking participants to make a judgement about whether personality traits were self related (self condition) or generally desirable traits (general condition) resulted in an MFG activation that was unique to the self condition (Fossati et al., 2003) and such effects may be enhanced in emotional disorders such as depression (Lemogne et al., 2009). Emotional responses to NSBs further activate regions known to be important in emotional processing more generally such as the amygdala (Goldin, Manber-Ball, Werner, Heimberg, & Gross, 2009). It has been suggested that higher order cortical areas such as anterior cingulate cortex (ACC) and medial and lateral prefrontal cortices are important in regulating emotion (Ochsner & Gross, 2005). Dysfunction in these higher order cortical circuits could contribute psychopathology. For example, although to the best of our knowledge there are no studies of the regulation of negative self beliefs in EDs, a study in another emotional disorder, social anxiety, has demonstrated that higher cognitive control regions are important in regulating emotional responses to NSBs, but these regions are less recruited in individuals with social anxiety disorder than in healthy controls (Goldin et al., 2009).
The present study considered the neural correlates of processing NSBs in unmedicated patients with BN. Although there have been no studies to date of the processing of self-referent emotional information in EDs, studies in the related disorder of depression have revealed aberrant patterns of activations in the MFG in patients (Lemogne et al., 2009). We therefore hypothesised that there would be altered patterns of activation in brain regions known to be important in the processing of NSBs (MFG) and in emotional responses to NSBs (amygdala). Such differences might be secondary to differences in the cognitive regulation of emotional responses to NSB involving higher order cognitive control regions. This seemed especially pertinent given the literature suggesting that negative self beliefs in EDs drive processes designed to regulate their associated affect and behaviour (Waller et al., 2007), as well as the evidence that BN may be associated with impaired cognitive control and impulsivity (Steiger & Bruce, 2007). Although there is considerable overlap between NSBs in ED and depression there is also emerging evidence suggest possible to distinguish between the content of beliefs between the two groups of disorders (Cooper and Cowen, 2009 and Fairchild and Cooper, 2010). We were therefore additionally interested in exploring whether there would be different neural responses to NSBs that have previously been associated with depression and those that have previously been associated with EDs and whether the NSBs associated with eating disorders would lead to the largest group differences.
