Inhibition-related functions in the human subcortex

Intact inhibition-related functions are paramount to successful and adaptive behaviour in daily life. Two such functions are response inhibition; the ability to suppress ongoing or prepared actions and interference resolution; the ability to selectively inhibit actions that are no longer relevant. How specifically these functions are implemented in the brain is not yet fully understood. Within this thesis I attempt to use advanced cognitive modelling techniques and tailored structural and functional magnetic resonance imaging (MRI) to shed light on this. We begin by detailing the importance of accurate structural imaging and the difficulty of investigating deeper parts of the brain, such as the subcortex. We then define specific subcortical nuclei in detail and quantify them in terms of their biochemical makeup and morphology. To gain an updated insight into the regions involved in response inhibition and interference resolution we performed a meta-analysis of studies exploiting these phenomena in the last decade using activation likelihood estimation. We subsequently sought to compare these types of inhibition intra-individually rather than inter-individually. Using ultra-high field magnetic resonance imaging we investigated response inhibition and interference resolution within the same individuals. Finally, the last chapter focuses on response inhibition where we reprocessed and reanalysed five full Stop Signal Task datasets to investigate discrepancies within the field.