title: Modulation of emotional appraisal by false physiological feedback during fMRI.
abstract: BACKGROUND
  James and Lange proposed that emotions are the perception of physiological reactions. Two-level theories of emotion extend this model to suggest that cognitive interpretations of physiological changes shape self-reported emotions. Correspondingly false physiological feedback of evoked or tonic bodily responses can alter emotional attributions. Moreover, anxiety states are proposed to arise from detection of mismatch between actual and anticipated states of physiological arousal. However, the neural underpinnings of these phenomena previously have not been examined.
  
  
  RESULTS
  We undertook a functional brain imaging (fMRI) experiment to investigate how both primary and second-order levels of physiological (viscerosensory) representation impact on the processing of external emotional cues. 12 participants were scanned while judging face stimuli during both exercise and non-exercise conditions in the context of true and false auditory feedback of tonic heart rate. We observed that the perceived emotional intensity/salience of neutral faces was enhanced by false feedback of increased heart rate. Regional changes in neural activity corresponding to this behavioural interaction were observed within included right anterior insula, bilateral mid insula, and amygdala. In addition, right anterior insula activity was enhanced during by asynchronous relative to synchronous cardiac feedback even with no change in perceived or actual heart rate suggesting this region serves as a comparator to detect physiological mismatches. Finally, BOLD activity within right anterior insula and amygdala predicted the corresponding changes in perceived intensity ratings at both a group and an individual level.
  
  
  CONCLUSIONS
  Our findings identify the neural substrates supporting behavioural effects of false physiological feedback, and highlight mechanisms that underlie subjective anxiety states, including the importance of the right anterior insula in guiding second-order "cognitive" representations of bodily arousal state.
authors.affiliation: Clinical Imaging Sciences Centre, Brighton Sussex Medical School, University of Sussex, Brighton, United Kingdom; Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom. mgray@bsms.ac.uk
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Gray
authors.forename: Neil A
authors.initials: NA
authors.lastname: Harrison
authors.forename: Stefan
authors.initials: S
authors.lastname: Wiens
authors.forename: Hugo D
authors.initials: HD
authors.lastname: Critchley
mesh_terms: D000328:Adult; D001007:Anxiety / Q000523:psychology*; D001676:Biofeedback, Psychology; D001931:Brain Mapping; D003243:Consciousness; D004644:Emotions / Q000502:physiology*; D015444:Exercise; D005149:Facial Expression; D056228:Feedback, Sensory; D005260:Female; D006339:Heart Rate; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male