We are proud to announce that Constantina Theofanopoulou will be defending her PhD thesis about the implications of oxytocin in speech on Thursday, the 21st of March, at 15:00 in this location on the UB campus. Her work was supervised by Cedric and co-supervised by Erich Jarvis. If you are curious to know more, read the abstract below or join us for the defense!
The overall aim of my thesis is to shed light on the interplay between the evolution of human sociality and the evolution of human language. My approach is multidisciplinary and includes studies ranging from genomic analyses in humans and other species to behavioral experiments in songbirds. Findings presented here lend genetic evidence to a specific hypothesis under which human sociality can be studied, the ‘self-domestication’ hypothesis, based on significant overlaps identified in the genes under positive selection in modern humans and several domesticated species. We further propose oxytocin as a good candidate molecule that underpins the genetic mechanisms of human prosociality and language, by serving as the molecular basis of social reward in spoken language acquisition. We show modern human-specific alleles in the oxytocin and the paralogous vasopressin/vasotocin receptors (particularly AVPR1A/VTR1A) correlate with a shift towards prosociality in modern-humans, along with three convergent variant changes in modern humans and bonobos, who have also been claimed to be self-domesticated. Additionally, we show an effect of social reward in tuning fine-grained aspects of vocal learning (i.e. pitch learning) in an experiment in zebra finches, providing support for the hypothesis on the importance of social feedback in human spoken-language acquisition. We also present preliminary findings on the role of oxytocin in singing in zebra finches; male zebra finches treated intranasally with an oxytocin-antagonist reduced significantly the number of introductory notes in the song they sang to attract females. Lastly, we propose a universal nomenclature for the vertebrate oxytocin and vasopressin/vasotocin ligands and receptors, which is based on multi-scale synteny analyses. The nomenclature will allow easier translation of findings across vertebrates and foster more informative design of experiments across species.