- There is considerable interest in the evolutionary history of the human brain. However since brains do not fossilize we need to rely on our understanding of different extant species. The ability to image the brains of closely related primates is opening new doors to understanding the evolutionary basis of cognitive abilities. We can now revisit classical questions in evolutionary biology with emergent technologies in neuroscience to obtain new insights into the evolutionary history of the human brain, including which animals serve well to model human brain function.
Human speech and language are recent evolutionary adaptations. But the traditional emphasis on the unique aspects of human communication, although generating considerable debate, has resulted in few empirical advances. We are still unclear on how the brains of primates evolved or which animals serve well to model human cognition.
We are gaining new insights into the vocal communication systems in primates. Our comparative vocal communication work also promises to clarify the origins of the speech regions in the human brain, even if these have no direct counterparts in extant species . These new observations are being facilitated by our ability to directly compare monkey imaging data on vocal communication to the available imaging data in humans .
We rely on a combination of functional magnetic resonance imaging (fMRI), microstimulation and multi-electrode electrophysiological recordings in behaving and anesthetized animals.
By using the same noninvasive imaging technology with behaving animals that is now the standard for imaging human brain function we are gaining new insights into the relationship between human and monkey brain networks for vocal communication. To assist medical science more directly, an international collaboration is now revealing the connectivity of the communication networks in monkeys with methods that are unfeasible for use with humans.
Our results with the connectivity of the vocal communication network are already suggesting new hypotheses for testing the function of the primate brain at the neuronal level. In this context we are evaluating how neurons in the anterior temporal lobe integrate faces and voices in behaviorally meaningful communication.