Dr Sukhbinder Kumar is a neuroscientist and is currently working as a Research Fellow at Wellcome Trust Centre for Neuroimaging, University College London (UCL) and Institute of Neuroscience, Newcastle University (UK). He received his PhD from Newcastle University (UK) in 2004. His research concerns understanding brain mechanisms of auditory perception, cognition and emotion processing in normal human subjects and how these mechanisms go wrong in disorders of perception such as musical hallucinations and disorders of emotion processing such as misophonia. To address these questions he uses functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) combined with computational modelling and behavioural testing. Dr Kumar has published over 30 peer-reviewed articles in neuroscience journals.
The Brain Basis For Misophonia | New Castle University Study
Dr. Sukhbinder Kumar and colleagues from the Institute of Neuroscience at New Castle University published a groundbreaking misophonia study in Current Biology (February, 2017). The research team measured three sets of sounds that were presented to both misophonics and to controls while they were in an MRI scanner. Sounds included typical misophonia “trigger sounds”, typically unpleasant sounds, as well as neutral sounds. Measurements of brain activity and autonomic responses (heart rate and galvanic skin response) were recorded in the MRI scanner. After presentation of each sound, misophonic and control subjects rated their level of distress. Common trigger sounds evoked a strong reaction in misophonic subjects, while the typically unpleasant sounds were reported as “annoying”. Notably, the typically unpleasant sounds did not result in heightened reactions in misophonics.
Brain imaging data showed greatly exaggerated activation of the anterior insular cortex (AIC) in people with misophonia, but not in controls. In addition, the heightened reactivity in misophonic subjects was specific to trigger sounds. For controls there was no difference between reactions to unpleasant versus trigger sounds.
The AIC detects personally relevant stimuli in the environment and directs attention to that stimulus. Stronger activation of AIC to trigger sounds demonstrates that misophonic subjects assign higher salience to trigger sounds.
In addition, analysis of functional connectivity of AIC showed hyper-connectivity, which was again specific to trigger sounds and to default mode network (DMN) in misophonic subjects. The DMN is active during internally directed thoughts and recall of memories.
Finally, analysis of structural brain data demonstrated that misophonics have greater myelination in the gray matter of ventromedial prefrontal cortex (vmPFC). This structural difference may account for the abnormal functional connectivity of AIC to DMN in misophonics. Overall, Kumar et al. showed abnormal activation and functional connectivity of AIC underlying the symptoms of misophonia.
Kumar, S., Hancock, OT., Sedley,, W., Winston, JS., Callaghan, MF., Allen M., Cope, TE., Gander, PE., Bamiou, DE., Griffiths, TD (2017). The brain basis for misophonia. Current Biology (in Press)