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Frontiers in psychology2020; 11; 575808; doi: 10.3389/fpsyg.2020.575808

Human Face Recognition in Horses: Data in Favor of a Holistic Process.

Abstract: Recent studies have demonstrated that horses can recognize humans based simply on visual information. However, none of these studies have investigated whether this involves the recognition of the face itself, or simply identifying people from non-complex external clues, such as hair color. To go beyond this we wanted to know whether certain features of the face were indispensable for this recognition (e.g., colors, hair or eyes). The 11 horses in this study had previously learned to identify four unfamiliar faces (portrait view and in color) presented repeatedly on a screen. We thus assessed whether they were able to identify these same faces spontaneously when they were presented in four other conditions: profile view, black and white, eyes hidden, changed hairstyle. The horses' performances remained higher than chance level for all the conditions. In a choice test under real conditions, they then approached the people whose face they had learned more often than unknown people. In conclusion, when considering all the individuals studied, no single facial element that we tested appears to be essential for recognition, suggesting holistic processing in face recognition. That means horses do not base their recognition solely on an easy clue such as hair color. They can also link faces from photographs with people in real life, indicating that horses do not process images of faces as simple abstract shapes.
Publication Date: 2020-09-15 PubMed ID: 33041946PubMed Central: PMC7522352DOI: 10.3389/fpsyg.2020.575808Google Scholar: Lookup
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  • Journal Article

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.

This research study looks into the ability of horses to recognize human faces, moving beyond identification using simple visual cues like hair color. The findings suggest horses use a holistic process to recognize faces, without relying on any single facial feature.

Research Overview

In the study, researchers conducted a series of tests on 11 horses which had been previously trained to recognize four unfamiliar human faces. These faces were colored, portrait images that were repeatedly presented to the horses on a screen. The main aim of the study was to determine whether horses recognized these faces based on certain specific features, like hair color or eyes, or whether they processed the faces as a whole for recognition.

Experiments and Conditions

  • The tests involved presenting the faces to the horses under different conditions: a side profile of the face, a black and white image, an image with the eyes hidden, and one with a changed hairstyle.
  • The researchers measured the horses’ responses to see if they could still identify the known individuals under these altered conditions.
  • In a real-life test, the horses were given a choice to approach either the individuals whose faces they had been trained to recognize or unknown people.

Findings

  • The test results show the horses’ performances in recognizing the trained images remained higher than chance level for all the conditions, indicating the animals were still able to recognize familiar individuals even without certain facial elements.
  • In the real-life test, the horses showed a higher tendency to approach the known individuals over the unknown ones, reinforcing the idea that they can link faces from photographs with real-life people.

Conclusion

The fact that the horses’ recognition performance did not drop significantly in any of the tests suggests that they do not rely on any single facial element for recognition, indicating a tendency for holistic face processing. Additionally, the direct link between photograph and real-life recognition implies that horses do not see images of faces merely as abstract shapes. Overall, the findings provide strong support for the idea that horses use a holistic process to recognize human faces.

Cite This Article

APA
Lansade L, Colson V, Parias C, Reigner F, Bertin A, Calandreau L. (2020). Human Face Recognition in Horses: Data in Favor of a Holistic Process. Front Psychol, 11, 575808. https://doi.org/10.3389/fpsyg.2020.575808

Publication

ISSN: 1664-1078
NlmUniqueID: 101550902
Country: Switzerland
Language: English
Volume: 11
Pages: 575808
PII: 575808

Researcher Affiliations

Lansade, Léa
  • PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.
Colson, Violaine
  • LPGP, INRAE, UR1037 Fish Physiology and Genomics, Rennes, France.
Parias, Céline
  • PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.
Reigner, Fabrice
  • Unité Expérimentale de Physiologie Animale de l'Orfrasière, Nouzilly, France.
Bertin, Aline
  • PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.
Calandreau, Ludovic
  • PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.

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Citations

This article has been cited 5 times.
  1. Liehrmann O, Cosnard C, Riihonen V, Viitanen A, Alander E, Jardat P, Koski SE, Lummaa V, Lansade L. What drives horse success at following human-given cues? An investigation of handler familiarity and living conditions.. Anim Cogn 2023 Jul;26(4):1283-1294.
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  2. Gouyet C, Ringhofer M, Yamamoto S, Jardat P, Parias C, Reigner F, Calandreau L, Lansade L. Horses cross-modally recognize women and men.. Sci Rep 2023 Mar 8;13(1):3864.
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  4. Popescu S, Lazar EA, Borda C, Blaga Petrean A, Mitrănescu E. Changes in Management, Welfare, Emotional State, and Human-Related Docility in Stallions.. Animals (Basel) 2022 Oct 30;12(21).
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