PhD Conferral Mrs. Catherine (Carine) J. Vossen, MSc.
Supervisors: prof.dr. E.A. Joosten; prof.dr. J. van Os, UU/UM
Co-supervisors: dr. R. Lousberg
"Cortical processing of pain; the role of habituation"
Pain is a subjective, multidimensional experience that depends on many factors, including pain stimulus intensity, expectations and mood. Compared to questionnaires, pain event-related potentials (pain ERP) allow pain to be evaluated more objectively. Pain ERP means that people receive pain stimuli, for instance electrical stimuli applied to the finger, with simultaneous registration of electrical brain activity. Habituation is an important phenomena following repeated exposure to pain stimuli, describing the progressive decrease of brain signal amplitude. Habituation occurs less in people with chronic pain and is considered a potential key mechanism in the development of chronic pain. Pain hypervigilance, i.e. heightened vigilance for pain sensations, has an impact on pain experience as well. This dissertation examines the relationship between habituation, hypervigilance and chronic pain. We used a new analysis method called the Event-Related Fixed-Interval Area (ERFIA) multilevel method, which not only evaluates ERP peaks, but also examines the pain ERP in closer detail. We showed that stimulus intensity, habituation and hypervigilance had an impact on large sections of the ERP. People with chronic pain showed reduced habituation independent of hypervigilance. Both chronic pain and hypervigilance were independently associated with reduced habituation of the pain ERP. These findings are relevant to the development of future treatment strategies.