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.
Copyright © 2020 Lansade, Colson, Parias, Reigner, Bertin and Calandreau.
Publication Date: 2020-09-15 PubMed ID: 33041946PubMed Central: PMC7522352DOI: 10.3389/fpsyg.2020.575808Google Scholar: Lookup
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Summary
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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
Researcher Affiliations
- PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.
- LPGP, INRAE, UR1037 Fish Physiology and Genomics, Rennes, France.
- PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.
- Unité Expérimentale de Physiologie Animale de l'Orfrasière, Nouzilly, France.
- PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.
- PRC, INRAE, CNRS, IFCE, University Tours, Nouzilly, France.
References
This article includes 36 references
- Avarguès-Weber A, d'Amaro D, Metzler M, Finke V, Baracchi D, Dyer AG. Does Holistic Processing Require a Large Brain? Insights From Honeybees and Wasps in Fine Visual Recognition Tasks.. Front Psychol 2018;9:1313.
- Bruce V, Young A. Understanding face recognition.. Br J Psychol 1986 Aug;77 ( Pt 3):305-27.
- Burke D, Sulikowski D. The evolution of holistic processing of faces.. Front Psychol 2013;4:11.
- Coulon M, Baudoin C, Heyman Y, Deputte BL. Cattle discriminate between familiar and unfamiliar conspecifics by using only head visual cues.. Anim Cogn 2011 Mar;14(2):279-90.
- Dalla Costa E, Minero M, Lebelt D, Stucke D, Canali E, Leach MC. Development of the Horse Grimace Scale (HGS) as a pain assessment tool in horses undergoing routine castration.. PLoS One 2014;9(3):e92281.
- Dilks DD, Cook P, Weiller SK, Berns HP, Spivak M, Berns GS. Awake fMRI reveals a specialized region in dog temporal cortex for face processing.. PeerJ 2015;3:e1115.
- Ferreira G, Keller M, Saint-Dizier H, Perrin G, Lévy F. Transfer between views of conspecific faces at different ages or in different orientations by sheep.. Behav Processes 2004 Nov 30;67(3):491-9.
- Gleerup KB, Forkman B, Lindegaard C, Andersen PH. An equine pain face.. Vet Anaesth Analg 2015 Jan;42(1):103-14.
- Hintze S, Smith S, Patt A, Bachmann I, Würbel H. Are Eyes a Mirror of the Soul? What Eye Wrinkles Reveal about a Horse's Emotional State.. PLoS One 2016;11(10):e0164017.
- Hjelmas E, Wroldsen J. Recognizing Faces from the Eyes Only. in Proceedings of the 11th Scandinavian Conference on Image Analysis, Greenland.
- Huber L, Racca A, Scaf B, Virányi Z, Range F. Discrimination of familiar human faces in dogs (Canis familiaris).. Learn Motiv 2013 Nov;44(4):258-269.
- Keppel G. Design and Analysis: A Researcher’s Handbook. Washington, DC: Prentice-Hall.
- Knolle F, Goncalves RP, Morton AJ. Sheep recognize familiar and unfamiliar human faces from two-dimensional images.. R Soc Open Sci 2017 Nov;4(11):171228.
- Lampe JF, Andre J. Cross-modal recognition of human individuals in domestic horses (Equus caballus).. Anim Cogn 2012 Jul;15(4):623-30.
- Lansade L, Colson V, Parias C, Trösch M, Reigner F, Calandreau L. Female horses spontaneously identify a photograph of their keeper, last seen six months previously.. Sci Rep 2020 Apr 14;10(1):6302.
- Lansade L, Nowak R, Lainé AL, Leterrier C, Bonneau C, Parias C, Bertin A. Facial expression and oxytocin as possible markers of positive emotions in horses.. Sci Rep 2018 Oct 2;8(1):14680.
- Lansade L, Philippon P, Hervé L, Vidament M. Development of personality tests to use in the field, stable over time and across situations, and linked to horses’ show jumping performance. Appl. Anim. Behav. Sci. 2016;176:43–51.
- Logan AJ, Gordon GE, Loffler G. Contributions of individual face features to face discrimination.. Vision Res 2017 Aug;137:29-39.
- Meinhardt-Injac B, Persike M. Recognition of briefly presented familiar and unfamiliar faces. Psihologija 2009;42:47–66.
- Mongillo P, Scandurra A, Kramer RSS, Marinelli L. Recognition of human faces by dogs (Canis familiaris) requires visibility of head contour.. Anim Cogn 2017 Sep;20(5):881-890.
- Murphy J, Gray KL, Cook R. The composite face illusion.. Psychon Bull Rev 2017 Apr;24(2):245-261.
- Nakabayashi K, Liu CH. Development of holistic vs. featural processing in face recognition.. Front Hum Neurosci 2014;8:831.
- Nakamura K, Takimoto-Inose A, Hasegawa T. Cross-modal perception of human emotion in domestic horses (Equus caballus).. Sci Rep 2018 Jun 21;8(1):8660.
- Nakamura T, Croft DB, Westbrook RF. Domestic pigeons (Columba livia) discriminate between photographs of individual pigeons.. Learn Behav 2003 Nov;31(4):307-17.
- Pokorny JJ, de Waal FB. Monkeys recognize the faces of group mates in photographs.. Proc Natl Acad Sci U S A 2009 Dec 22;106(51):21539-43.
- Proops L, Grounds K, Smith AV, McComb K. Animals Remember Previous Facial Expressions that Specific Humans Have Exhibited.. Curr Biol 2018 May 7;28(9):1428-1432.e4.
- Proops L, McComb K. Cross-modal individual recognition in domestic horses (Equus caballus) extends to familiar humans.. Proc Biol Sci 2012 Aug 22;279(1741):3131-8.
- Proops L, McComb K, Reby D. Cross-modal individual recognition in domestic horses (Equus caballus).. Proc Natl Acad Sci U S A 2009 Jan 20;106(3):947-51.
- Schell A, Rieck K, Schell K, Hammerschmidt K, Fischer J. Adult but not juvenile Barbary macaques spontaneously recognize group members from pictures.. Anim Cogn 2011 Jul;14(4):503-9.
- Smith AV, Proops L, Grounds K, Wathan J, McComb K. Functionally relevant responses to human facial expressions of emotion in the domestic horse (Equus caballus).. Biol Lett 2016 Feb;12(2):20150907.
- Stone SM. Human facial discrimination in horses: can they tell us apart?. Anim Cogn 2010 Jan;13(1):51-61.
- Trindade PHE, Hartmann E, Keeling LJ, Andersen PH, Ferraz GC, Paranhos da Costa MJR. Effect of work on body language of ranch horses in Brazil.. PLoS One 2020;15(1):e0228130.
- Trösch M, Cuzol F, Parias C, Calandreau L, Nowak R, Lansade L. Horses Categorize Human Emotions Cross-Modally Based on Facial Expression and Non-Verbal Vocalizations.. Animals (Basel) 2019 Oct 24;9(11).
- Trösch M, Pellon S, Cuzol F, Parias C, Nowak R, Calandreau L, Lansade L. Horses feel emotions when they watch positive and negative horse-human interactions in a video and transpose what they saw to real life.. Anim Cogn 2020 Jul;23(4):643-653.
- Tsao DY, Moeller S, Freiwald WA. Comparing face patch systems in macaques and humans.. Proc Natl Acad Sci U S A 2008 Dec 9;105(49):19514-9.
- Wathan J, Proops L, Grounds K, McComb K. Horses discriminate between facial expressions of conspecifics.. Sci Rep 2016 Dec 20;6:38322.
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