Learning is essential to behavior, enabling organisms to draw on past experience to improve choices. A fundamental question is how different brain systems involved in learning interact to support adaptive decisions. With funding from the National Science Foundation, Daphne Shohamy is addressing this fundamental question. One way in which people gradually learn the relationship between actions and outcomes is by using trial-by-error feedback. This type of learning has traditionally been defined as implicit or habitual, and it is thought to depend on a neural structure called the striatum. A distinct and independent learning system is thought to uniquely support explicit memory for facts and events and to depend on the hippocampus. Emerging data suggest that this dual-system view of memory is over-simplified. This research program explores how different brain systems for learning interact and jointly guide behavior. The project adopts an integrative approach that draws on functional magnetic resonance imaging (fMRI) studies in healthy individuals, combined with studies of learning in patients with isolated damage to specific brain systems. Imaging studies provide insight into the spatial and temporal characteristics of brain and cognitive mechanisms. Patient studies augment evidence of the necessity of a system for specific learning processes. By integrating functional imaging and patient research, results from this project will contribute to a deeper understanding of the role of the striatum and the hippocampus in learning, and of how these learning systems interact to guide adaptive behavior.
This research program provides unique opportunities for training and education at both the undergraduate and graduate levels. Integrating multiple core tools of cognitive neuroscience (functional imaging, patient studies, behavioral analyses), students are trained in different approaches to a unified research question. Through this training, they learn to value the principle of converging methods, a theme that is further emphasized in a program of regular joint meetings with students and faculty in laboratories with complementary expertise. Determining the brain and cognitive mechanisms underlying different forms of learning will lay the foundation for potential future interventions to improve education and treat learning deficits, both in healthy individuals and in individuals with brain disorders. To facilitate this translational process, the research program forms the basis of a program of public outreach about the relevance of research on learning and the brain for education and public health. Public lectures and an undergraduate course on cognitive neuroscience in the media focus on broad communication of the relevance of cognitive neuroscience research for many aspects of society, including education, law and medicine.
