Neuronal substrates of vocal processing in primates
Many social animals, including primates, rely on vocal information for their social interactions, and are experts at interpreting voices. We know that the temporal lobe in the brains of humans and other primates contain dedicated areas specialized for processing voices. However how vocal information is encoded at the neuronal level in these brain regions was unknown.
I have addressed several aspects of this question in my PhD research, performed in Prof. Nikos Logothetis’ Physiology of Cognitive Processes Department at the Max Planck Institute for Biological Cybernetics under the supervision of Dr. Christopher Petkov. To do so, I used extracellular electrophysiology to characterize the neuronal processing of communication signals in a higher-order ‘voice’-sensitive area in primates. This work newly revealed specialized neuronal substrates for voice processing, ‘voice cells’ that appear to use a different stimulus encoding strategy than analogous ‘face cells’ in the visual modality (Perrodin et al., Current Biology 2011). Next I studied how vocal processing is affected by a simultaneously presented face (Perrodin et al., Journal of Neuroscience 2014). Finally, I described how the type of neuronal multisensory influences can be predicted by natural asynchronies in audiovisual communication signals, via an oscillatory phase-resetting mechanism (Perrodin et al, PNAS 2015). In a recent review paper my co-authors and I considered the wider conceptual implications of our and others’ experimental work on current theoretical models for person identity processing in the brains of humans and nonhuman primates (Perrodin et al, TiCS).