Cognitive control of vocalizations in corvid songbirds

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Avian vocalisations are one of the most extravagant communicative signals in the animal kingdom. The elaborate and often plastic vocalisations of songbirds in particular, which are learned by vocal imitation of conspecifics, require highly controlled execution of complex motor programmes. Because of the similarities in how songs are heard, learned and produced, the avian song system serves as a model system to study sensory-motor aspects of human speech. However, as of yet, relatively little is known about whether songbirds can cognitively control their vocalisations. More specifically, we do not know whether or not they can volitionally emit or withhold vocalisations, as opposed to only vocalise reflexively and in response to specific hedonic cues, such as food or predators. In a set of three studies, I propose to explore this question by training carrion crows, a species of songbird known for their sophisticated behavioural repertoire, to vocalise in response to arbitrary learned cues, and to withhold vocalisations to other cues. In order to assess the neuronal mechanisms of this behaviour, electrophysiological signals from the brain area “nidopallium caudolaterale” (NCL) will be recorded. The NCL is a high-level associative area, which is considered as functionally analogous to the primate prefrontal cortex because it is involved in decision making, working memory, and abstract cognition. Lastly, it will be assessed whether the NCL is causally involved in volitional vocalisations by temporarily inactivating this brain area. Additional recordings in area HVC, a nucleus considered to be involved in the control of vocal sequences, will explore functional connections of the song-system and the NCL in vocal control. This set of studies will yield insights about the neural circuits and mechanisms underlying the cognitive control of vocal behaviour in the avian species. This line of research promises to link aspects of executive funtions to the plastic sensory-motor network of the avian song system.