One of the hallmarks of schizophrenia is the distortion of reality, including delusions. Delusions are fixed false beliefs that are held despite contradictory evidence. Delusional schizophrenia patients tend to overestimate the plausibility of potential beliefs that others would consider implausible. However, the mechanisms by which schizophrenia patients develop delusions and hold onto them in the face of contradictory evidence is not well understood. When individuals form beliefs, they assess the plausibility of a potential belief in the context of the evidence at hand. In doing so, they must consider two main factors: whether the potential belief can adequately account for the evidence at hand, and whether there are any other alternate potential beliefs that could account for this evidence. Once a belief has been established, most individuals tend to resist re-evaluating these beliefs when presented with contradictory evidence. This effect is stronger in delusional patients. Jennifer Whitman is working to determine the cognitive underpinnings of delusions. Her studies will compare delusional schizophrenia patients with non-delusional patients and healthy individuals, using simple guessing games to reveal the factors influencing how schizophrenic patients form their beliefs, how they remain fixated on them, and how this differs from non-delusional individuals. She will also conduct neuroimaging studies to identify the brain systems underlying these cognitive mechanisms. Whitman’s work will be useful for informing how delusion-prone individuals can be taught the logical reasoning skills they need to re-evaluate current delusions and avoid developing delusions. Understanding these brain systems may also be relevant for assessing the effectiveness of different pharmacological treatments and predicting relapse and treatment responsiveness by mapping changes in these brain systems over time.