Skip to content

Determining the role of the behavioural inhibition system in humans: an electroencephalographic examination of revised reinforcement sensitivity theory

Student thesis: Doctoral Thesis

Reinforcement Sensitivity Theory (RST) provides a neurological account of animal and human personality through the study of brain-behaviour systems. However, there is uncertainty regarding the role of each brain-behaviour system, particularly the Behavioural Inhibition System (BIS). The most recent version of RST proposes that the BIS responds to goal conflict and directs defensive approach. There is already a great deal of neurological evidence to support this proposal in animals. However, comparatively little neurological research has examined this proposal in humans. To address this, I analysed human EEG activity during goal conflict and defensive approach within three PhD research studies.
in neurological theta can indicate the involvement of the BIS. Therefore, if the BIS responds to goal conflict and directs defensive approach in humans, then increases theta EEG should be visible during goal conflict and defensive approach in humans. To test this, I first examined changes in EEG during a goal conflict task. This particular task improves on previous designs through its use of an ability calibration mechanism5. In a follow up study, I examined changes in sub-second theta during goal conflict using a separate goal conflict task. Finally, in a third study, I employed a unique task that involved a live human confederate, posing as a social threat, to motivate participants toward defensive approach. Frontal-posterior theta coherence increased during goal conflict, across both goal conflict tasks, and during defensive approach, within the defensive approach task. Additionally, midfrontocentral theta CSD power increased during goal conflict, across both goal conflict tasks, but not during defensive approach. Overall, my findings provide novel neurological evidence that the BIS does respond to goal conflict and does direct defensive approach in humans.
Original languageEnglish
Awarding Institution
Supervisors/Advisors
Award dateJun 2019
Relations Get citation (various referencing formats)

ID: 14403485