In this project, we propose to identify the alterations in neural systems in patients with Parkinson’s Disease (PD) that could account for previously observed reductions in religiosity and in fluent access to religious concepts. We will use advances in functional connectivity magnetic resonance imaging (fcMRI) techniques, new psychophysical cognitive priming techniques, and classical ‘on-off’ levodopa (LD) comparative techniques to identify brain system alterations linked with religious cognition changes in these patients. In addition, two doctoral students and one post-doctoral fellow will be trained in the scientific background and experimental techniques relevant to this project. The post-doc will receive advanced training in fcMRI analyses relevant to ‘religion and brain’ issues while the doctoral students will be integrated into all aspects of hypothesis testing procedures of the project. In a series of publications, we have demonstrated that access to religious concepts is reduced in left-onset patients with PD (McNamara et al., 2006a,b; Butler et al., 2011a,b), that these patients report fewer religious experiences (McNamara et al., 2006a) and fewer religious interests/goals (McNamara et al., 2006b), and that they engage in fewer religious practices (Butler et al., 2011a,b) than age-matched control individuals who are also coping with chronic disease. The proposed studies will identify alterations in brain function that could account for this array of deficits. We believe our work with these patients will identify key sources of their deficits as well as illuminate fundamental issues in the neuroscience of religious beliefs, behaviors, and experiences.