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Proceedings. Biological sciences2012; 279(1741); 3131-3138; doi: 10.1098/rspb.2012.0626

Cross-modal individual recognition in domestic horses (Equus caballus) extends to familiar humans.

Abstract: It has recently been shown that some non-human animals can cross-modally recognize members of their own taxon. What is unclear is just how plastic this recognition system can be. In this study, we investigate whether an animal, the domestic horse, is capable of spontaneous cross-modal recognition of individuals from a morphologically very different species. We also provide the first insights into how cross-modal identity information is processed by examining whether there are hemispheric biases in this important social skill. In our preferential looking paradigm, subjects were presented with two people and playbacks of their voices to determine whether they were able to match the voice with the person. When presented with familiar handlers subjects could match the specific familiar person with the correct familiar voice. Horses were significantly better at performing the matching task when the congruent person was standing on their right, indicating marked hemispheric specialization (left hemisphere bias) in this ability. These results are the first to demonstrate that cross-modal recognition in animals can extend to individuals from phylogenetically very distant species. They also indicate that processes governed by the left hemisphere are central to the cross-modal matching of visual and auditory information from familiar individuals in a naturalistic setting.
Publication Date: 2012-05-16 PubMed ID: 22593108PubMed Central: PMC3385734DOI: 10.1098/rspb.2012.0626Google 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.

This research study investigates whether domestic horses can recognize familiar humans not just visually, but also by the sound of their voice, demonstrating the capability for cross-modal recognition between different species. The study also suggests a left hemisphere bias in this ability.

About the Research

  • The study focuses on exploring the ability of an animal to cross-modally recognize individuals of a significantly different species, using domestic horses as subjects for the research.
  • It expands upon previous knowledge that some non-human animals are capable of cross-modal recognition within their own species.
  • Cross-modal recognition refers to the ability to match information acquired from different sensory modalities – in this case, matching a familiar voice (auditory input) to a visual image of a person (visual input).

Methodology and Key Findigs

  • The researchers used a preferential looking paradigm where horses were presented with two people along with playbacks of their voices.
  • The objective was to determine whether horses could accurately identify a familiar person by matching their voice with their image.
  • The results indicated that when presented with familiar handlers, horses could indeed match the familiar person with the correct voice.
  • The study found a marked hemispheric specialization in this ability – horses were significantly better at performing the matching task when the person was positioned on their right side, indicating a left hemisphere bias.

Significance of the Research

  • This study is the first to demonstrate that cross-modal recognition in animals can extend to individuals from phylogenetically very distant species – in this case, humans.
  • It also suggests that processes governed by the left hemisphere play a crucial role in the cross-modal matching of visual and auditory information from familiar individuals.
  • This understanding can contribute to advancements in animal cognition study, particularly relating to interspecies understanding and communication.

Cite This Article

APA
Proops L, McComb K. (2012). Cross-modal individual recognition in domestic horses (Equus caballus) extends to familiar humans. Proc Biol Sci, 279(1741), 3131-3138. https://doi.org/10.1098/rspb.2012.0626

Publication

ISSN: 1471-2954
NlmUniqueID: 101245157
Country: England
Language: English
Volume: 279
Issue: 1741
Pages: 3131-3138

Researcher Affiliations

Proops, Leanne
  • Mammal Vocal Communication and Cognition Research, School of Psychology, University of Sussex, Brighton BN1 9QH, UK. leanne.proops@gmail.com
McComb, Karen

    MeSH Terms

    • Animals
    • Auditory Perception
    • Female
    • Horses / psychology
    • Humans
    • Male
    • Recognition, Psychology
    • Social Behavior
    • Species Specificity
    • Visual Perception

    Grant Funding

    • Biotechnology and Biological Sciences Research Council

    References

    This article includes 46 references
    1. Ettlinger G. Analysis of cross-modal effects and their relationship to language. 1967 In Brain mechanisms underlying speech (ed. Darley F. L.), pp. 53–60 New York, NY: Grune & Stratton.
    2. Seyfarth RM, Cheney DL. Seeing who we hear and hearing who we see.. Proc Natl Acad Sci U S A 2009 Jan 20;106(3):669-70.
    3. 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.
    4. Sliwa J, Duhamel JR, Pascalis O, Wirth S. Spontaneous voice-face identity matching by rhesus monkeys for familiar conspecifics and humans.. Proc Natl Acad Sci U S A 2011 Jan 25;108(4):1735-40.
    5. Bovet D, Deputte BL. Matching vocalizations to faces of familiar conspecifics in grey-cheeked mangabeys (Lophocebus albigena).. Folia Primatol (Basel) 2009;80(3):220-32.
      doi: 10.1159/000235688doi: 10.1159/000235688pubmed: 19710557google scholar: lookup
    6. Kondo N, Izawa E, Watanabe S. Crows cross-modally recognize group members but not non-group members.. Proc Biol Sci 2012 May 22;279(1735):1937-42.
    7. Scott LS, Pascalis O, Nelson CA. A Domain-General Theory of the Development of Perceptual Discrimination.. Curr Dir Psychol Sci 2007;16(4):197-201.
    8. Pascalis O, Scott LS, Kelly DJ, Shannon RW, Nicholson E, Coleman M, Nelson CA. Plasticity of face processing in infancy.. Proc Natl Acad Sci U S A 2005 Apr 5;102(14):5297-300.
    9. Adachi I, Kuwahata H, Fujita K. Dogs recall their owner's face upon hearing the owner's voice.. Anim Cogn 2007 Jan;10(1):17-21.
    10. Stone SM. Human facial discrimination in horses: can they tell us apart?. Anim Cogn 2010 Jan;13(1):51-61.
    11. Krueger K, Flauger B, Farmer K, Maros K. Horses (Equus caballus) use human local enhancement cues and adjust to human attention.. Anim Cogn 2011 Mar;14(2):187-201.
    12. Taubert J. Chimpanzee faces are 'special' to humans.. Perception 2009;38(3):343-56.
      doi: 10.1068/p6254doi: 10.1068/p6254pubmed: 19485131google scholar: lookup
    13. MacNeilage PF, Rogers LJ, Vallortigara G. Origins of the left & right brain.. Sci Am 2009 Jul;301(1):60-7.
    14. Rogers L J. Relevance of brain and behavioural lateralization to animal welfare. Appl. Anim. Behav. Sci 2010 127, 1–11.
    15. Rogers L J. Lateralization in vertebrates: its early evolution, general pattern, and development. Adv. Study Behav 2002 31, 107–161.
    16. Davidson R J. Emotion and affective style: hemispheric substrates. Psychol. Sci 1992 3, 39–43.
    17. Ley RG, Bryden MP. Hemispheric differences in processing emotions and faces.. Brain Lang 1979 Jan;7(1):127-38.
    18. Workman L, Peters S, Taylor S. Lateralisation of perceptual processing of pro- and anti-social emotions displayed in chimeric faces.. Laterality 2000 Jul;5(3):237-49.
      doi: 10.1080/713754378doi: 10.1080/713754378pubmed: 15513144google scholar: lookup
    19. Daisley JN, Mascalzoni E, Rosa-Salva O, Rugani R, Regolin L. Lateralization of social cognition in the domestic chicken (Gallus gallus).. Philos Trans R Soc Lond B Biol Sci 2009 Apr 12;364(1519):965-81.
    20. Farmer K, Krueger K, Byrne RW. Visual laterality in the domestic horse (Equus caballus) interacting with humans.. Anim Cogn 2010 Mar;13(2):229-38.
    21. Campanella S, Belin P. Integrating face and voice in person perception.. Trends Cogn Sci 2007 Dec;11(12):535-43.
    22. von Kriegstein K, Giraud AL. Implicit multisensory associations influence voice recognition.. PLoS Biol 2006 Oct;4(10):e326.
    23. Joassin F, Pesenti M, Maurage P, Verreckt E, Bruyer R, Campanella S. Cross-modal interactions between human faces and voices involved in person recognition.. Cortex 2011 Mar;47(3):367-76.
    24. Hertrich I, Dietrich S, Ackermann H. Cross-modal interactions during perception of audiovisual speech and nonspeech signals: an fMRI study.. J Cogn Neurosci 2011 Jan;23(1):221-37.
    25. Gaffan D, Harrison S. Auditory-visual associations, hemispheric specialization and temporal-frontal interaction in the rhesus monkey.. Brain 1991 Oct;114 ( Pt 5):2133-44.
    26. Delfour F, Marten K. Lateralized visual behavior in bottlenose dolphins (Tursiops truncatus) performing audio-visual tasks: the right visual field advantage.. Behav Processes 2006 Jan 10;71(1):41-50.
    27. Spelke E S. Preferential looking methods as tools for the study of cognition in infancy. 1985 In Measurement of audition and vision in the first year of postnatal life (eds Gottleib G., Krasnegor N.), pp. 323–363 Norwood, NJ: Ablex.
    28. Ghazanfar AA, Turesson HK, Maier JX, van Dinther R, Patterson RD, Logothetis NK. Vocal-tract resonances as indexical cues in rhesus monkeys.. Curr Biol 2007 Mar 6;17(5):425-30.
    29. Leopold DA, Rhodes G. A comparative view of face perception.. J Comp Psychol 2010 Aug;124(3):233-51.
      doi: 10.1037/a0019460doi: 10.1037/a0019460pmc: PMC2998394pubmed: 20695655google scholar: lookup
    30. Adachi I, Kuwahata H, Fujita K, Tomonaga M, Matsuzawa T. Plasticity of ability to form cross-modal representations in infant Japanese macaques.. Dev Sci 2009 Apr;12(3):446-52.
    31. Racca A, Amadei E, Ligout S, Guo K, Meints K, Mills D. Discrimination of human and dog faces and inversion responses in domestic dogs (Canis familiaris).. Anim Cogn 2010 May;13(3):525-33.
    32. Sugita Y. Face perception in monkeys reared with no exposure to faces.. Proc Natl Acad Sci U S A 2008 Jan 8;105(1):394-8.
    33. Kendrick KM. Brain asymmetries for face recognition and emotion control in sheep.. Cortex 2006 Jan;42(1):96-8.
    34. Guo K, Meints K, Hall C, Hall S, Mills D. Left gaze bias in humans, rhesus monkeys and domestic dogs.. Anim Cogn 2009 May;12(3):409-18.
    35. Belin P. Voice processing in human and non-human primates.. Philos Trans R Soc Lond B Biol Sci 2006 Dec 29;361(1476):2091-107.
    36. Brancucci A, Lucci G, Mazzatenta A, Tommasi L. Asymmetries of the human social brain in the visual, auditory and chemical modalities.. Philos Trans R Soc Lond B Biol Sci 2009 Apr 12;364(1519):895-914.
    37. Peirce JW, Kendrick KM. Functional asymmetry in sheep temporal cortex.. Neuroreport 2002 Dec 20;13(18):2395-9.
    38. Seeck M, Michel CM, Mainwaring N, Cosgrove R, Blume H, Ives J, Landis T, Schomer DL. Evidence for rapid face recognition from human scalp and intracranial electrodes.. Neuroreport 1997 Aug 18;8(12):2749-54.
    39. Rhodes G. Lateralized processes in face recognition.. Br J Psychol 1985 May;76 ( Pt 2):249-71.
    40. Vallortigara G, Snyder A, Kaplan G, Bateson P, Clayton NS, Rogers LJ. Are animals autistic savants.. PLoS Biol 2008 Feb;6(2):e42.
    41. Proops L, McComb K. Attributing attention: the use of human-given cues by domestic horses (Equus caballus).. Anim Cogn 2010 Mar;13(2):197-205.
    42. Duberstein K J, Gilkeson J A. Determination of sex differences in personality and trainability of yearling horses utilizing a handler questionnaire. Appl. Anim. Behav. Sci 2010 128, 57–63.
    43. Cameron EZ, Setsaas TH, Linklater WL. Social bonds between unrelated females increase reproductive success in feral horses.. Proc Natl Acad Sci U S A 2009 Aug 18;106(33):13850-3.
    44. Murphy J, Sutherland A, Arkins S. Idiosyncratic motor laterality in the horse. Appl. Anim. Behav. Sci 2005 91, 297–310.
    45. Brooks DE, Komàromy AM, Källberg ME. Comparative retinal ganglion cell and optic nerve morphology.. Vet Ophthalmol 1999;2(1):3-11.
    46. Harman AM, Moore S, Hoskins R, Keller P. Horse vision and an explanation for the visual behaviour originally explained by the 'ramp retina'.. Equine Vet J 1999 Sep;31(5):384-90.

    Citations

    This article has been cited 57 times.
    1. Felici M, Reddon AR, Maglieri V, Lanatà A, Baragli P. Heart and brain: Change in cardiac entropy is related to lateralised visual inspection in horses. PLoS One 2023;18(8):e0289753.
      doi: 10.1371/journal.pone.0289753pubmed: 37552685google scholar: lookup
    2. Marchand WR. Potential Mechanisms of Action and Outcomes of Equine-Assisted Services for Veterans with a History of Trauma: A Narrative Review of the Literature. Int J Environ Res Public Health 2023 Jul 16;20(14).
      doi: 10.3390/ijerph20146377pubmed: 37510609google scholar: lookup
    3. Gammino B, Palacios V, Root-Gutteridge H, Reby D, Gamba M. Grey wolves (Canis lupus) discriminate between familiar and unfamiliar human voices. Anim Cogn 2023 Sep;26(5):1589-1600.
      doi: 10.1007/s10071-023-01796-9pubmed: 37338632google scholar: lookup
    4. Lõoke M, Guérineau C, Broseghini A, Marinelli L, Mongillo P. Meowing dogs: can dogs recognize cats in a cross-modal violation of expectancy task (Canis familiaris)?. Anim Cogn 2023 Jul;26(4):1335-1344.
      doi: 10.1007/s10071-023-01783-0pubmed: 37171527google scholar: lookup
    5. 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.
      doi: 10.1038/s41598-023-30830-6pubmed: 36890162google scholar: lookup
    6. 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).
      doi: 10.3390/ani12212981pubmed: 36359105google scholar: lookup
    7. Scopa C, Maglieri V, Baragli P, Palagi E. Getting rid of blinkers: the case of mirror self-recognition in horses (Equus caballus). Anim Cogn 2022 Aug;25(4):711-716.
      doi: 10.1007/s10071-022-01638-0pubmed: 35704243google scholar: lookup
    8. Leinwand JG, Fidino M, Ross SR, Hopper LM. Familiarity mediates apes' attentional biases toward human faces. Proc Biol Sci 2022 Apr 27;289(1973):20212599.
      doi: 10.1098/rspb.2021.2599pubmed: 35473378google scholar: lookup
    9. Krueger K, Schwarz S, Marr I, Farmer K. Laterality in Horse Training: Psychological and Physical Balance and Coordination and Strength Rather Than Straightness. Animals (Basel) 2022 Apr 16;12(8).
      doi: 10.3390/ani12081042pubmed: 35454288google scholar: lookup
    10. Baciadonna L, Solvi C, La Cava S, Pilenga C, Gamba M, Favaro L. Cross-modal individual recognition in the African penguin and the effect of partnership. Proc Biol Sci 2021 Oct 13;288(1960):20211463.
      doi: 10.1098/rspb.2021.1463pubmed: 34641734google scholar: lookup
    11. Brubaker L, Schroeder K, Sherwood D, Stroud D, Udell MAR. Horse Behavior towards Familiar and Unfamiliar Humans: Implications for Equine-Assisted Services. Animals (Basel) 2021 Aug 11;11(8).
      doi: 10.3390/ani11082369pubmed: 34438825google scholar: lookup
    12. Lee VE, Thornton A. Animal cognition in an urbanised world. Front Ecol Evol 2021 Mar 4;9.
      doi: 10.3389/fevo.2021.633947pubmed: 34409044google scholar: lookup
    13. Ragonese G, Baragli P, Mariti C, Gazzano A, Lanatà A, Ferlazzo A, Fazio E, Cravana C. Interspecific two-dimensional visual discrimination of faces in horses (Equus caballus). PLoS One 2021;16(2):e0247310.
      doi: 10.1371/journal.pone.0247310pubmed: 33606816google scholar: lookup
    14. Scopa C, Greco A, Contalbrigo L, Fratini E, Lanatà A, Scilingo EP, Baragli P. Inside the Interaction: Contact With Familiar Humans Modulates Heart Rate Variability in Horses. Front Vet Sci 2020;7:582759.
      doi: 10.3389/fvets.2020.582759pubmed: 33330706google scholar: lookup
    15. Lange A, Bauer L, Futschik A, Waiblinger S, Lürzel S. Talking to Cows: Reactions to Different Auditory Stimuli During Gentle Human-Animal Interactions. Front Psychol 2020;11:579346.
      doi: 10.3389/fpsyg.2020.579346pubmed: 33178082google scholar: lookup
    16. Lansade L, Colson V, Parias C, Reigner F, Bertin A, Calandreau L. Human Face Recognition in Horses: Data in Favor of a Holistic Process. Front Psychol 2020;11:575808.
      doi: 10.3389/fpsyg.2020.575808pubmed: 33041946google scholar: lookup
    17. Quaranta A, d'Ingeo S, Amoruso R, Siniscalchi M. Emotion Recognition in Cats. Animals (Basel) 2020 Jun 28;10(7).
      doi: 10.3390/ani10071107pubmed: 32605256google scholar: lookup
    18. Carlson NV, Kelly EM, Couzin I. Individual vocal recognition across taxa: a review of the literature and a look into the future. Philos Trans R Soc Lond B Biol Sci 2020 Jul 6;375(1802):20190479.
      doi: 10.1098/rstb.2019.0479pubmed: 32420840google scholar: lookup
    19. Schrimpf A, Single MS, Nawroth C. Social Referencing in the Domestic Horse. Animals (Basel) 2020 Jan 18;10(1).
      doi: 10.3390/ani10010164pubmed: 31963699google scholar: lookup
    20. Scopa C, Contalbrigo L, Greco A, Lanatà A, Scilingo EP, Baragli P. Emotional Transfer in Human-Horse Interaction: New Perspectives on Equine Assisted Interventions. Animals (Basel) 2019 Nov 26;9(12).
      doi: 10.3390/ani9121030pubmed: 31779120google scholar: lookup
    21. Semin GR, Scandurra A, Baragli P, Lanatà A, D'Aniello B. Inter- and Intra-Species Communication of Emotion: Chemosignals as the Neglected Medium. Animals (Basel) 2019 Oct 31;9(11).
      doi: 10.3390/ani9110887pubmed: 31683710google scholar: lookup
    22. 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).
      doi: 10.3390/ani9110862pubmed: 31653088google scholar: lookup
    23. Bernauer K, Kollross H, Schuetz A, Farmer K, Krueger K. How do horses (Equus caballus) learn from observing human action?. Anim Cogn 2020 Jan;23(1):1-9.
      doi: 10.1007/s10071-019-01310-0pubmed: 31531748google scholar: lookup
    24. Baba C, Kawai M, Takimoto-Inose A. Are Horses (Equus caballus) Sensitive to Human Emotional Cues?. Animals (Basel) 2019 Aug 29;9(9).
      doi: 10.3390/ani9090630pubmed: 31470656google scholar: lookup
    25. d'Ingeo S, Quaranta A, Siniscalchi M, Stomp M, Coste C, Bagnard C, Hausberger M, Cousillas H. Horses associate individual human voices with the valence of past interactions: a behavioural and electrophysiological study. Sci Rep 2019 Aug 9;9(1):11568.
      doi: 10.1038/s41598-019-47960-5pubmed: 31399629google scholar: lookup
    26. Mendonça RS, Ringhofer M, Pinto P, Inoue S, Hirata S. Feral horses' (Equus ferus caballus) behavior toward dying and dead conspecifics. Primates 2020 Jan;61(1):49-54.
      doi: 10.1007/s10329-019-00728-xpubmed: 31134472google scholar: lookup
    27. Nawroth C, Langbein J, Coulon M, Gabor V, Oesterwind S, Benz-Schwarzburg J, von Borell E. Farm Animal Cognition-Linking Behavior, Welfare and Ethics. Front Vet Sci 2019;6:24.
      doi: 10.3389/fvets.2019.00024pubmed: 30838218google scholar: lookup
    28. Gergely A, Petró E, Oláh K, Topál J. Auditory⁻Visual Matching of Conspecifics and Non-Conspecifics by Dogs and Human Infants. Animals (Basel) 2019 Jan 7;9(1).
      doi: 10.3390/ani9010017pubmed: 30621092google scholar: lookup
    29. Leroux M, Hetem RS, Hausberger M, Lemasson A. Cheetahs discriminate familiar and unfamiliar human voices. Sci Rep 2018 Oct 19;8(1):15516.
      doi: 10.1038/s41598-018-33971-1pubmed: 30341369google scholar: lookup
    30. Nawroth C, Albuquerque N, Savalli C, Single MS, McElligott AG. Goats prefer positive human emotional facial expressions. R Soc Open Sci 2018 Aug;5(8):180491.
      doi: 10.1098/rsos.180491pubmed: 30225038google scholar: lookup
    31. Smith AV, Proops L, Grounds K, Wathan J, Scott SK, McComb K. Domestic horses (Equus caballus) discriminate between negative and positive human nonverbal vocalisations. Sci Rep 2018 Aug 29;8(1):13052.
      doi: 10.1038/s41598-018-30777-zpubmed: 30158532google scholar: lookup
    32. 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.
      doi: 10.1038/s41598-018-26892-6pubmed: 29930289google scholar: lookup
    33. Rakotonirina H, Kappeler PM, Fichtel C. The role of facial pattern variation for species recognition in red-fronted lemurs (Eulemur rufifrons). BMC Evol Biol 2018 Feb 13;18(1):19.
      doi: 10.1186/s12862-018-1126-0pubmed: 29433448google scholar: lookup
    34. Benson-Amram S, Gilfillan G, McComb K. Numerical assessment in the wild: insights from social carnivores. Philos Trans R Soc Lond B Biol Sci 2017 Feb 19;373(1740).
      doi: 10.1098/rstb.2016.0508pubmed: 29292356google scholar: lookup
    35. Baragli P, Vitale V, Sighieri C, Lanata A, Palagi E, Reddon AR. Consistency and flexibility in solving spatial tasks: different horses show different cognitive styles. Sci Rep 2017 Nov 29;7(1):16557.
      doi: 10.1038/s41598-017-16729-zpubmed: 29185468google scholar: lookup
    36. Baragli P, Demuru E, Scopa C, Palagi E. Are horses capable of mirror self-recognition? A pilot study. PLoS One 2017;12(5):e0176717.
      doi: 10.1371/journal.pone.0176717pubmed: 28510577google scholar: lookup
    37. Pitcher BJ, Briefer EF, Baciadonna L, McElligott AG. Cross-modal recognition of familiar conspecifics in goats. R Soc Open Sci 2017 Feb;4(2):160346.
      doi: 10.1098/rsos.160346pubmed: 28386412google scholar: lookup
    38. Wathan J, Proops L, Grounds K, McComb K. Horses discriminate between facial expressions of conspecifics. Sci Rep 2016 Dec 20;6:38322.
      doi: 10.1038/srep38322pubmed: 27995958google scholar: lookup
    39. Albuquerque N, Guo K, Wilkinson A, Savalli C, Otta E, Mills D. Dogs recognize dog and human emotions. Biol Lett 2016 Jan;12(1):20150883.
      doi: 10.1098/rsbl.2015.0883pubmed: 26763220google scholar: lookup
    40. Kriengwatana B, Escudero P, Ten Cate C. Revisiting vocal perception in non-human animals: a review of vowel discrimination, speaker voice recognition, and speaker normalization. Front Psychol 2014;5:1543.
      doi: 10.3389/fpsyg.2014.01543pubmed: 25628583google scholar: lookup
    41. Romero T, Nagasawa M, Mogi K, Hasegawa T, Kikusui T. Oxytocin promotes social bonding in dogs. Proc Natl Acad Sci U S A 2014 Jun 24;111(25):9085-90.
      doi: 10.1073/pnas.1322868111pubmed: 24927552google scholar: lookup
    42. Kulahci IG, Drea CM, Rubenstein DI, Ghazanfar AA. Individual recognition through olfactory-auditory matching in lemurs. Proc Biol Sci 2014 Jun 7;281(1784):20140071.
      doi: 10.1098/rspb.2014.0071pubmed: 24741013google scholar: lookup
    43. McComb K, Shannon G, Sayialel KN, Moss C. Elephants can determine ethnicity, gender, and age from acoustic cues in human voices. Proc Natl Acad Sci U S A 2014 Apr 8;111(14):5433-8.
      doi: 10.1073/pnas.1321543111pubmed: 24616492google scholar: lookup
    44. Rochais C, Henry S, Sankey C, Nassur F, Góracka-Bruzda A, Hausberger M. Visual attention, an indicator of human-animal relationships? A study of domestic horses (Equus caballus). Front Psychol 2014;5:108.
      doi: 10.3389/fpsyg.2014.00108pubmed: 24592244google scholar: lookup
    45. Proops L, Rayner J, Taylor AM, McComb K. The Responses of Young Domestic Horses to Human-Given Cues. PLoS One 2013;8(6):e67000.
      doi: 10.1371/journal.pone.0067000pubmed: 23840572google scholar: lookup
    46. Henselek Y, Fischer J, Schloegl C. Does the stimulus type influence horses' performance in a quantity discrimination task?. Front Psychol 2012;3:504.
      doi: 10.3389/fpsyg.2012.00504pubmed: 23181043google scholar: lookup
    47. Ricci-Bonot C, Brosche K, Baragli P, Nicol C. A systematic review on the effect of individual characteristics and management practices on equine cognition. Anim Cogn 2025 Nov 26;28(1):96.
      doi: 10.1007/s10071-025-02016-2pubmed: 41296132google scholar: lookup
    48. Lee VE, McIvor GE, Thornton A. Wild jackdaws recognise the contact calls of their mate. Anim Cogn 2025 Nov 26;28(1):97.
      doi: 10.1007/s10071-025-02020-6pubmed: 41296111google scholar: lookup
    49. Root-Gutteridge H, Korzeniowska A, Ratcliffe V, Reby D. Domestic dogs (Canis familiaris) recognise meaningful content in monotonous streams of read speech. Anim Cogn 2025 Apr 12;28(1):29.
      doi: 10.1007/s10071-025-01948-zpubmed: 40220068google scholar: lookup
    50. Torres Borda L, Auer U, Jenner F. The role of space availability and affiliation in shaping equine social distances and dynamics. Sci Rep 2025 Mar 25;15(1):10273.
      doi: 10.1038/s41598-025-92943-4pubmed: 40133443google scholar: lookup
    51. Mason MA, Semple S, Marshall HH, McElligott AG. Do goats recognise humans cross-modally?. PeerJ 2025;13:e18786.
      doi: 10.7717/peerj.18786pubmed: 39830959google scholar: lookup
    52. Callara AL, Scopa C, Contalbrigo L, Lanatà A, Scilingo EP, Baragli P, Greco A. Unveiling directional physiological coupling in human-horse interactions. iScience 2024 Sep 20;27(9):110857.
      doi: 10.1016/j.isci.2024.110857pubmed: 39310749google scholar: lookup
    53. Sgadò P, Pross A, Lamanna J, Adiletta A. Face processing in animal models: implications for autism spectrum disorder. Front Neurosci 2024;18:1462272.
      doi: 10.3389/fnins.2024.1462272pubmed: 39184326google scholar: lookup
    54. Goma AA, Uddin J, Kieson E. Lateralised Behavioural Responses in Livestock to Environmental Stressors: Implications for Using Infrared Thermography to Assess Welfare Conditions. Animals (Basel) 2023 Nov 27;13(23).
      doi: 10.3390/ani13233663pubmed: 38067014google scholar: lookup
    55. Maeda T, Yamamoto S. Drone Observation for the Quantitative Study of Complex Multilevel Societies. Animals (Basel) 2023 Jun 8;13(12).
      doi: 10.3390/ani13121911pubmed: 37370421google scholar: lookup
    56. Levey DJ, Poulsen JR, Schaeffer AP, Deochand ME, Oswald JA, Robinson SK, Londoño GA. Wild mockingbirds distinguish among familiar humans. Sci Rep 2023 Jun 24;13(1):10259.
      doi: 10.1038/s41598-023-36225-xpubmed: 37355713google scholar: lookup
    57. Humphrey T, Proops L, Forman J, Spooner R, McComb K. The role of cat eye narrowing movements in cat-human communication. Sci Rep 2020 Oct 5;10(1):16503.
      doi: 10.1038/s41598-020-73426-0pubmed: 33020542google scholar: lookup