Control and causal learning in the human brain and their links to mental health

Thesis

Humans often collaborate towards joint outcomes and can navigate complex social situations. In this thesis, I investigated the computational and neural mechanisms underlying human learning in social contexts, and their links to schizotypy and depression.

Collaborating with others requires humans to ascertain their individual level of control over shared outcomes (reviewed in chapter 1). I demonstrated that in ambiguous social contexts, people engage in specific patterns of behaviour that I refer to as active disambiguation (chapter 2). This process helps individuals establish what they themselves, as opposed to others, control and what consequence they themselves cause or that another person causes. People identify when active disambiguation is needed and engage in it at that time. A pattern of activity in the supramarginal gyrus, emerging during and after active disambiguation, is linked to establishing controllability and tracking the outcomes from which control is inferred (chapter 3). Activity in this brain region also signals a second learning mechanism, by which individuals attribute outcomes to themselves versus others, in proportion to their perceived control.

Understanding control and agency estimation may inform our understanding of psychological illness. I found that individuals with schizotypal traits rely more on external cues to estimate their level of control and learn about their own abilities (chapter 4). Firstly, they take outcomes furnished from active disambiguation more into account to estimate their control – behaviour which is in fact closer to simulated behaviour from an optimal computational learning model. Secondly, they fail to assign outcomes to themselves when their perceived control is low. Neural signals of outcome processing from active disambiguation are reduced in schizotypy (chapter 5). This reveals a potentially distinct neural mechanism by which outcome attribution may be altered in schizotypal traits.

Authors: Spiering, L

• DOI: 10.5287/ora-kk0m5mv7y
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Subjects: Cognitive neuroscience; Computational neuroscience