New insights into the neural substrates of the perception of species-specific vocalizations in zebra finches: an fMRI approach
28 September 2017
UAntwerp, Campus Drie Eiken, Building O, Auditorium O1 - Universiteitsplein 1 - 2610 Wilrijk (Antwerp) (route: UAntwerpen, Campus Drie Eiken
5:00 PM - 7:00 PM
Lisbeth Van Ruijssevelt
Annemie Van der Linden
PhD defence Lisbeth Van Ruijssevelt - Department of Biomedical Sciences
In social species, the production and perception of communication signals are critical to survival and reproduction. Mammals and birds, for example, communicate through vocal signals which can carry a multitude of information including the signalers identity as well as his emotional state and the social context in which he resides. An accurate evaluation of these signals is crucial to interpret the sound’s behavioral relevance and decide on the proper response. Despite the importance of such social information processing, relatively little is known about the neurobiological mechanisms underlying the decoding of acoustic information in species-specific vocalizations.
Songbirds, and zebra finches in particular, present an excellent model to study such auditory processing mechanisms. Consequently, this PhD project was aimed at getting better insights into the mechanisms of auditory processing of socially relevant communication signals in zebra finches.
We used functional magnetic resonance imaging (fMRI) which allows to visualize brain activity throughout the entire brain in a non-invasive manner. The technique was applied to study neural processing of songs with varying social relevance. Male zebra finches adjust their song depending on social context. For example, when singing to females they produce songs that are longer, faster, and more stereotyped (female directed ‘FD’ song) compared to when singing while alone (undirected ‘UD’ song). To elucidate how social information is decoded in the brain, we studied FD versus UD song perception in females, who have a strong preference for the FD song. Males, who do not have a similar preference for FD over UD song, were studied as a control group to enable the dissociation of perceptual processes related to the interpretation of social relevance of the signal from mere decoding mechanisms related to differences in acoustic features between the songs. We found that neural responses within the classical auditory pathway are influenced by variation in acoustical features, but not by the song’s behavioral relevance for the receiver. Additionally, we uncovered a novel region outside the classical auditory pathway involved in the interpretation of social information in song and in coordinating resulting behavioral responses.
As such, this PhD project provides unique novel insights into the neural substrates of auditory social cues in zebra finches and thus contributes to the further characterization of mechanisms for social perception in this animal model. Ultimately this can contribute to studies on and the development of appropriate models for social interaction disorders like e.g. autism, in which the interpretation of social information based on prosodic cues of vocalizations, is impaired.