Newsportal - Ruhr-Universität Bochum
Humans identify emotions in voices of all air-breathing vertebrates
Amphibians, reptiles, mammals – all of them communicate via acoustic signals. And humans are able to assess the emotional value of these signals. This has been shown in a new study conducted by researchers at Vrije Universiteit Brussel and Ruhr-Universität Bochum, in collaboration with colleagues from Alberta, Canada, and Vienna, Austria, in the journal “Proceedings of the Royal Society B”. They interpreted these findings as evidence that there might be a universal code for the vocal expression and perception of emotions in the animal kingdom. Previous studies had demonstrated that humans are capable of identifying emotions in the voices of different mammals. The new study results have been expanded to include amphibians and reptiles.
The team headed by Dr Piera Filippi, currently at the University of Aix-Marseille and the Max Planck Institute for Psycholinguistics in the Netherlands, included, amongst others, three academics from Bochum: philosophy scholar Prof Dr Albert Newen, biopsychologist Prof Dr Dr h. c. Onur Güntürkün and assistant professor Dr Sebastian Ocklenburg.
Animal voices for different classes of vertebrates
Participants in the study included 75 individuals whose native language was English, German or Mandarin. They listened to audio recordings of nine different species of land-living vertebrates in the classes mammals, amphibians and reptiles, with the latter including birds and other reptiles (see audio samples below).
Participants were able to distinguish between high and low levels of arousal in the acoustic signals of all animal classes. To do so, they mainly relied on frequency-related parameters in the signal.
“The findings suggest that fundamental mechanisms for the acoustic expression of emotions exist across all classes of vertebrates,” conclude the authors. The evolutionary roots of this signal system might be shared by all vocalizing vertebrates. This finding goes in the direction of what Charles Darwin suggested more than a century ago, namely that acoustic expressions of emotion can be traced back to our earliest land-dwelling ancestors.
Audio samples of animal calls
The collaboration between Piera Filippi and the researchers from Bochum was realised thanks to a fellowship that was awarded by the Center for Mind, Brain and Cognitive Evolution in Bochum.
Piera Filippi et al.: Humans recognize emotional arousal in vocalizations across all classes of terrestrial vertebrates: Evidence for acoustic universals, in: Proceedings of the Royal Society B, 2017, DOI:10.1098/rspb.2017.0990
Dr Piera Filippi
Brain and Language Research Institute
University of Aix-Marseille, France
and Max Planck Institute for Psycholinguistics
Nijmegen, the Netherlands
Phone: +32 483 180754, +33 7 85026938
Prof Dr Onur Güntürkün
Department of Biopsychology
Faculty of Psychology
Ruhr-Universität Bochum, Germany
Phone: +49 234 32 26213
Prof Dr Albert Newen
Institute of Philosophy II
Faculty of Philosophy and Educational Research
Ruhr-Universität Bochum, Germany
Phone: +49 234 32 22139
Prof Dr Bart De Boer
Artificial Intelligence Lab
Vrije Universiteit Brussel, Belgium
26 July 2017