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Home / Equine Research Bank / Sci Rep / Segregation of information about emotional arousal and valen...
Scientific reports2015; 4; 9989; doi: 10.1038/srep09989

Segregation of information about emotional arousal and valence in horse whinnies.

Abstract: Studying vocal correlates of emotions is important to provide a better understanding of the evolution of emotion expression through cross-species comparisons. Emotions are composed of two main dimensions: emotional arousal (calm versus excited) and valence (negative versus positive). These two dimensions could be encoded in different vocal parameters (segregation of information) or in the same parameters, inducing a trade-off between cues indicating emotional arousal and valence. We investigated these two hypotheses in horses. We placed horses in five situations eliciting several arousal levels and positive as well as negative valence. Physiological and behavioral measures collected during the tests suggested the presence of different underlying emotions. First, using detailed vocal analyses, we discovered that all whinnies contained two fundamental frequencies ("F0" and "G0"), which were not harmonically related, suggesting biphonation. Second, we found that F0 and the energy spectrum encoded arousal, while G0 and whinny duration encoded valence. Our results show that cues to emotional arousal and valence are segregated in different, relatively independent parameters of horse whinnies. Most of the emotion-related changes to vocalizations that we observed are similar to those observed in humans and other species, suggesting that vocal expression of emotions has been conserved throughout evolution.
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Publication Date: 2015-04-21 PubMed ID: 25897781PubMed Central: PMC4404681DOI: 10.1038/srep09989Google Scholar: Lookup
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  • Journal Article
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  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The given research investigates how horses communicate different emotions – calmness or excitement, positivity or negativity – through their vocalizations, or ‘whinnies.’ The study finds that various elements of these ‘whinnies’ distinctly convey either the emotional arousal or the valence (positive or negative nature) of the horse’s feelings.

Research Objectives

  • The primary objectives of this research were to explore the means by which emotional dimensions (namely, emotional arousal and valence) are encoded in the vocal parameters of horse whinnies.
  • The researchers aimed to determine whether these two emotional aspects are presented separately (information segregation) or intertwined, which would create a balancing act between cues indicating emotional arousal and emotional valence.

Methodology

  • For their experiment, the researchers exposed horses to five different scenarios designed to elicit varying levels of arousal and both negative and positive emotional valence.
  • They collected physiological and behavioural data during these tests to infer the emotions experienced by the horses.
  • The researchers kept a keen eye on the vocal responses emitted by the horses to understand how they express emotions verbally.

Findings

  • Through minute vocal analyses, the researchers observed that all horse whinnies contain two fundamental frequencies, “F0” and “G0”, which are not harmonically related, implying a biphonic or two-voiced vocalization.
  • The study found that F0 and the energy spectrum encapsulated the arousal level, whereas G0 and the duration of the whinny determined the valence of that emotion.

Significance of the Findings

  • The research proves that emotional arousal and valence cues are divided across different independent vocal parameters of a horse’s whinny. This implies that a horse communicates its emotional state using a complex system where different elements of its vocalizations convey different aspects of its emotions.
  • This study’s observations bear resemblance to the changes seen in human and other species’ vocalizations with emotional shifts, suggesting the possibility of a universal, evolution-conserved vocal expression system for feelings across different species.

Cite This Article

APA
Briefer EF, Maigrot AL, Mandel R, Freymond SB, Bachmann I, Hillmann E. (2015). Segregation of information about emotional arousal and valence in horse whinnies. Sci Rep, 4, 9989. https://doi.org/10.1038/srep09989

Publication

Scientific reports
ISSN: 2045-2322
NlmUniqueID: 101563288
Country: England
Language: English
Volume: 4
Pages: 9989
PII: 9989

Researcher Affiliations

Briefer, Elodie F
  • ETH Zürich, Institute of Agricultural Sciences, Universitätstrasse 2, 8092, Zürich, Switzerland.
Maigrot, Anne-Laure
  • ETH Zürich, Institute of Agricultural Sciences, Universitätstrasse 2, 8092, Zürich, Switzerland.
  • Agroscope - Swiss National Stud Farm, Les Longs Prés, P.O. Box 191, 1580, Avenches, Switzerland.
Mandel, Roi
  • ETH Zürich, Institute of Agricultural Sciences, Universitätstrasse 2, 8092, Zürich, Switzerland.
  • Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University, Rehovot, 76100, Israel.
Freymond, Sabrina Briefer
  • Agroscope - Swiss National Stud Farm, Les Longs Prés, P.O. Box 191, 1580, Avenches, Switzerland.
Bachmann, Iris
  • Agroscope - Swiss National Stud Farm, Les Longs Prés, P.O. Box 191, 1580, Avenches, Switzerland.
Hillmann, Edna
  • ETH Zürich, Institute of Agricultural Sciences, Universitätstrasse 2, 8092, Zürich, Switzerland.

MeSH Terms

  • Animals
  • Arousal / physiology
  • Biological Evolution
  • Cues
  • Euphoria / physiology
  • Female
  • Frustration
  • Horses / physiology
  • Humans
  • Male
  • Sound
  • Vocalization, Animal / physiology

Conflict of Interest Statement

The authors declare that they have no competing financial interests.

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