2010/01/01 by Lyudmila Trut, Lyudmila N. Trut, Anastasia Kharlamova +7 · 7 citations
Biochemistry, Genetics and Molecular Biology · Psychology · #Animal Vocal Communication and Behavior #Human-Animal Interaction Studies #Neuroendocrine regulation and behavior
paper · doi:10.1163/000579510x528242
Summary The hypothesis of similarity in trends of acoustic characteristics regardless of the sign of emotional arousal, positive or negative, has been advanced based on human vocalizations. For non-human mammals, testing is complicated because the same stimulus cannot evoke opposite (positive and negative) internal states, to trigger the respective vocalizations. To resolve this concern, we designed an experimental procedure using Tame and Aggressive strains of silver foxes, with genetically predetermined positive or negative emotional responses to humans respectively. We analyzed features of vocalizations produced by callers at different fox‐human distances, assuming changes in vocal responses reflect the shifts of human-related positive arousal in Tame foxes and human-related negative arousal in Aggressive foxes. Both strains showed similar trends for changes in calling rate and proportion of time spent vocalizing toward higher levels in response to greater emotional arousal, positive in Tame foxes and negative in Aggressive foxes. At the same time, strains showed distinctive trends for the proportions of different call types and maximum amplitude frequency. We infer that the variables with similar trends reflect the strength of emotional arousal, regardless of triggering internal states, whereas variables with distinctive trends are specifically related to the sign of emotion in silver fox.