Hippocampal-prefrontal contributions to knowledge acquisition and representation
Abstract: Everyday behaviors require a high degree of flexibility, in which prior knowledge is applied to inform behavior in new situations. Such flexibility is thought to be supported in part by memory integration, a process whereby related experiences become interconnected in the brain through recruitment of overlapping neuronal populations. In this talk, I will discuss our work demonstrating that memory integration relies on hippocampal-prefrontal (PFC) circuitry and allows for acquisition of new knowledge beyond what we directly experience. I will show that hippocampal-PFC coupling during encoding of new events that overlap with existing knowledge reflects a memory-by-memory updating process that supports novel reasoning decisions. I will further show that hippocampal-PFC coupling during rest periods following memory updating evince continued restructuring of interrelated memories during offline periods. Moreover, I will discuss how dynamic knowledge restructuring impacts the representation of individual memory elements within hippocampal and PFC subregions, resulting in integrated conceptual representations that reflect the similarities among events. Finally, I will review our recent data, which suggest that the development of reasoning ability through childhood and adolescence may result in part from the maturation of memory integration processes supported by the hippocampus and PFC.