Doctoral Dissertation Research: The Evolution of the Neural Basis of Learning and Behavioral Control

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Every thought, memory, and decision that someone experiences is created by different parts of the brain. And while great progress has been made in understanding the functions of diverse brain networks, their evolution remains less well characterized. This doctoral dissertation project focuses on a crucial network in the evolution of intelligence, the cortico-striatal system (CSS), which mediates learning and the regulation of behavior, two of the most outstanding cognitive adaptations in humans. The investigator measures the neuroanatomical variation of the CSS across many primate species, thereby enhancing our understanding of the evolutionary changes in the brain that led to the emergence of human intelligence and cognition. The project also includes public science outreach activities and generation of open source data. This research also has impact beyond the anthropological sciences by informing clinical research on species-specific vulnerability to neurodegenerative diseases and addiction. This project studies the relative size and connectivity of the CSS across primates. As specific subregions of the striatum mediate different modes of learning and stages of behavioral control, the investigator quantifies the variation of the relative volumes of the three striatal nuclei to understand how CSS-based learning and behav-ioral optimization have evolved in primates. The connectivity of the striatal subregions is measured across pri-mates to elucidate selection on cortico-striatal pathways that may relate to species-specific behavioral de-mands. The project employs phylogenetic comparative methods to model changes in scaling and rates of evolu-tion of functionally specific components of the CSS at different taxonomic levels (e.g., primate order, anthro-poid suborder, human genus). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.