The Brain Basis for Misophonia.
Misophonia is an affective sound-processing disorder characterized by the experience of strong negative emotions (anger and anxiety) in response to everyday sounds, such as those generated by other people eating, drinking, chewing, and breathing [1-8]. The commonplace nature of these sounds (often referred to as "trigger sounds") makes misophonia a devastating disorder for sufferers and their families, and yet nothing is known about the underlying mechanism. Using functional and structural MRI coupled with physiological measurements, we demonstrate that misophonic subjects show specific trigger-sound-related responses in brain and body. Specifically, fMRI showed that in misophonic subjects, trigger sounds elicit greatly exaggerated blood-oxygen-level-dependent (BOLD) responses in the anterior insular cortex (AIC), a core hub of the "salience network" that is critical for perception of interoceptive signals and emotion processing. Trigger sounds in misophonics were associated with abnormal functional connectivity between AIC and a network of regions responsible for the processing and regulation of emotions, including ventromedial prefrontal cortex (vmPFC), posteromedial cortex (PMC), hippocampus, and amygdala. Trigger sounds elicited heightened heart rate (HR) and galvanic skin response (GSR) in misophonic subjects, which were mediated by AIC activity. Questionnaire analysis showed that misophonic subjects perceived their bodies differently: they scored higher on interoceptive sensibility than controls, consistent with abnormal functioning of AIC. Finally, brain structural measurements implied greater myelination within vmPFC in misophonic individuals. Overall, our results show that misophonia is a disorder in which abnormal salience is attributed to particular sounds based on the abnormal activation and functional connectivity of AIC.
Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Wellcome Trust Centre for Neuroimaging, 12 Queen Square, London WC1N 3BG, UK. Electronic address: sukhbinder.kumar@ncl.ac.uk.
Sukhbinder
S
Kumar
Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Olana
O
Tansley-Hancock
Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
William
W
Sedley
Wellcome Trust Centre for Neuroimaging, 12 Queen Square, London WC1N 3BG, UK; Institute of Cognitive Neuroscience, 17 Queen Square, London WC1N 3AR, UK.
Joel S
JS
Winston
Wellcome Trust Centre for Neuroimaging, 12 Queen Square, London WC1N 3BG, UK.
Martina F
MF
Callaghan
Wellcome Trust Centre for Neuroimaging, 12 Queen Square, London WC1N 3BG, UK.
Micah
M
Allen
Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0SZ, UK.
Thomas E
TE
Cope
Human Brain Research Laboratory, Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA.
Phillip E
PE
Gander
UCL Ear Institute, 332 Grays Inn Road, London WC1X 8EE, UK.
Doris-Eva
DE
Bamiou
Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; Wellcome Trust Centre for Neuroimaging, 12 Queen Square, London WC1N 3BG, UK.
Timothy D
TD
Griffiths
D000328:Adult; D000786:Anger / Q000502:physiology*; D001008:Anxiety Disorders / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D004644:Emotions / Q000502:physiology; D005260:Female; D005712:Galvanic Skin Response; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013016:Sound / Q000009:adverse effects*; D055815:Young Adult
affective disorders; autonomic response; fMRI; functional connectivity; interoception; misophonia