A tractography atlas was created with 29 chimpanzee scans with comparable atlases for humans and rhesus macaques (fig. 1). These data were used to compute cortical surface projections, cortical fingerprints, and cortical blueprints. Two fMRI projects were designed to probe object categorization and to disambiguate the processing of concepts, narrative, and social stimuli.
Results
Atlas results (1) replicated known differences between humans, chimpanzees, and macaques regarding the arcuate fasciculus, (2) identified modifications to the superior longitudinal fasciculus system unique to humans, and (3) found modifications to the inferior fronto-occipital fasciculus unique to humans, which has implications for human ventral stream visual processing, which has a role in conceptual processing.
Cortical blueprint results (fig. 2) indicate changes to white matter in human and hominoid lineages in the temporal lobes, as we had hypothesized, but also in inferior parietal areas. Differences between humans and macaques also included changes to lateral prefrontal areas. Thus humans and great apes appear to share modifications to prefrontal white matter, while parietal and posterior temporal white matter was modified after humans diverged from other great apes.
Our fMRI category and conceptual processing project found prefrontal areas, in concert with early visual areas, are involved in processes that support differentiating concepts into categories. This supports an enactivist model of conceptual processing. The results from this study, combined with preliminary findings from a colleague, lead us to design the second fMRI study, in which participants are exposed to longer duration stimuli in an effort to better understand the relationship between conceptual processing and social and other contextual cues.
Dissemination
Four conference posters were presented - (Cortical Evolution Conference, Spain, Society for Neuroscience Conference, USA, Organization for Human Brain Mapping Conference, Italy). Four talks were given (J.B. Johnston Club, USA, Max Planck Institute for Psycholinguistics, NL, Comparative MRI, DE, Bias in AI and Neuroscience Conference, NL). I co-authored 4 additional poster presentations and a conference talk. A paper on white matter mapping (2018), and on the intersection of feminist science and neuroimaging (2019) were published. A book chapter on the human temporal lobe was published (2018) and another is in final editing. Three papers are in preparation, based on the chimpanzee atlas, the blueprint data, and the first fMRI study; a fourth paper is anticipated from the second fMRI project.
I co-organized two international conferences during the grant period - one on the role of bias in AI and neuroscience, held at the host institution (2019) and one on the interface of gender studies and neuroscience, to be held in the host country in 2020. I was also interviewed for a Dutch documentary and for a column in the Dutch newspaper of record.
