Information gathering and motivated decision making in health and disease

Thesis

Almost every aspect of our lives involves making decisions. From deciding to get out of bed in the morning to saying "I do" at a long-awaited wedding. Humans, like animals, often try to optimise their decisions to maximise reward and avoid losses. Understanding the mechanisms and neural correlates of such behaviours can provide crucial insights into human cognitive and psychological functioning in health and disease. In this thesis, two common forms of motivated decision making are examined: i) decision making under uncertainty and information gathering, and ii) effort-based decision making (EBDM). Through behavioural experimentation, computational modelling, and neuroimaging analysis, I reveal novel mechanisms and brain networks involved in these forms of behaviour and investigate their clinical implication on affect and motivation. In addition to healthy humans, different groups of patients were investigated, including autoimmune limbic encephalitis (ALE), subjective cognitive impairment (SCI), and Alzheimer’s disease (AD). The results across these study groups converged to characterise two potentially dissociable psycho-cognitive-brain axes. The first draws a link between uncertainty processing, affect, and the hippocampus. The second highlights the relationship between apathy (reduced motivation), deficits in EBDM, and key functional brain networks such as default mode and fronto-parietal networks. The findings in this thesis thus highlight an experimental and mechanistic framework for investigating information gathering and EBDM, and provide insights into their clinical implications and associated brain networks.

Authors: Attaallah, B

• DOI: 10.5287/ora-bpgy414vb
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: depression; effort-based decision making; decision making; hippocampus; information gathering; apathy; subjective cognitive impairment; uncertainty; anxiety; Alzheimer's disease; brain networks; limbic encephalitis