{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T03:05:48Z","timestamp":1792638348232,"version":"4.5.0"},"reference-count":74,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,1,6]],"date-time":"2026-01-06T00:00:00Z","timestamp":1767657600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T00:00:00Z","timestamp":1769731200000},"content-version":"vor","delay-in-days":24,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Sci Rep"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    Reduced rapid-eye-movement (REM) sleep is associated with impaired learning in many species. We developed a reversal learning test (RLT) suitable for field conditions to explore this association in 16 healthy horses. Nocturnal REM-like sleep behavior was recorded five times for 48\u00a0h over a six-week period. The horses performed a target training task followed by an RLT using two objects. When the horses reached a predefined frequency of touching the object, the spatial location was reversed. Mean test parameters were statistically analysed using GENLIN models, longitudinal continuous variables were analysed using linear repeated measures models, and dichotomous repeated measures were analysed using GEE models and Kaplan-Meier method. Altogether 15\/16 horses completed RLT by reversing three or more times. Most errors occurred before the second and third reversals. Overall, REM sleep duration (mean\u2009\u00b1\u2009SE) was 46.1\u2009\u00b1\u20098.7\u00a0min. However, there were ten horses that exhibited REM-like sleep for less than 30\u00a0min (10.6\u2009\u00b1\u20092.2\u00a0min, range 0.0\u201328.0\u00a0min), while six horses exhibited REM-like sleep for at least 30\u00a0min (42.3\u2009\u00b1\u20094.8\u00a0min, range 36.6\u201365.8\u00a0min). Longer REM sleep was associated with a greater number of reversals (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009=\u20090.04), while no relationship was found with error rate. Survival analysis further indicated a significant difference in progression probability between groups, with horses with shorter REM sleep having a 50% chance of progressing after five reversals, compared to six reversals for longer REM sleepers (\n                    <jats:italic>p<\/jats:italic>\n                    \u2009&lt;\u20090.05). We present here a method to test horses\u2019 reversal learning ability on site over a single day. We found that short REM-like sleep duration without clinical signs of sleep disturbances in horses was associated with poorer performance and lower perseverance during the RLT.\n                  <\/jats:p>","DOI":"10.1038\/s41598-025-34463-9","type":"journal-article","created":{"date-parts":[[2026,1,6]],"date-time":"2026-01-06T16:16:15Z","timestamp":1767716175000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Effect of horse sleep behavior on performance in a field-side spatial reversal learning test"],"prefix":"10.1038","volume":"16","author":[{"given":"Mira Joanna","family":"H\u00e4m\u00e4l\u00e4inen","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Iina Liisa","family":"Brotherus","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Henna-Kaisa Margareta","family":"Wigren","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tuire Eriikka","family":"Kaimio","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heli","family":"Suomala","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna-Mari","family":"Olbricht","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura Talvikki","family":"H\u00e4nninen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna Kristina","family":"Mykk\u00e4nen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,1,6]]},"reference":[{"key":"34463_CR1","doi-asserted-by":"publisher","first-page":"1050","DOI":"10.1016\/j.neuron.2023.03.005","volume":"111","author":"S Brodt","year":"2023","unstructured":"Brodt, S., Inostroza, M., Niethard, N. & Born, J. Sleep\u2014A brain-state serving systems memory consolidation. Neuron 111, 1050\u20131075 (2023).","journal-title":"Neuron"},{"key":"34463_CR2","doi-asserted-by":"publisher","first-page":"114","DOI":"10.1038\/nrn2762","volume":"11","author":"S Diekelmann","year":"2010","unstructured":"Diekelmann, S. & Born, J. The memory function of sleep. Nat. Rev. Neurosci. 11, 114\u2013126 (2010).","journal-title":"Nat. Rev. Neurosci."},{"key":"34463_CR3","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1038\/s41386-019-0432-6","volume":"45","author":"AN Hudson","year":"2020","unstructured":"Hudson, A. N., Van Dongen, H. P. A. & Honn, K. A. Sleep deprivation, vigilant attention, and brain function: a review. Neuropsychopharmacology 45, 21\u201330 (2020).","journal-title":"Neuropsychopharmacology"},{"key":"34463_CR4","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1016\/j.neubiorev.2018.03.017","volume":"89","author":"O Tkachenko","year":"2018","unstructured":"Tkachenko, O. & Dinges, D. F. Interindividual variability in neurobehavioral response to sleep loss: A comprehensive review. Neurosci. Biobehav Rev. 89, 29\u201348 (2018).","journal-title":"Neurosci. Biobehav Rev."},{"key":"34463_CR5","doi-asserted-by":"crossref","unstructured":"Yuksel, C. et al. Both slow wave and rapid eye movement sleep contribute to emotional memory consolidation. Commun Biol 8, 485 (2025).","DOI":"10.1038\/s42003-025-07868-5"},{"key":"34463_CR6","doi-asserted-by":"publisher","first-page":"167","DOI":"10.1016\/j.conb.2017.05.001","volume":"44","author":"R Boyce","year":"2017","unstructured":"Boyce, R., Williams, S. & Adamantidis, A. REM sleep and memory. Curr. Opin. Neurobiol. 44, 167\u2013177 (2017).","journal-title":"Curr. Opin. Neurobiol."},{"key":"34463_CR7","first-page":"658","volume":"31","author":"Y Ruckebusch","year":"1970","unstructured":"Ruckebusch, Y., Barbey, P. & Quillemot, P. Stages of sleep in the horse (Equus caballus). Les etats de sommeil Chez Le cheval (Equus caballus). CR soc. Biol. 31, 658\u2013665 (1970).","journal-title":"CR soc. Biol."},{"key":"34463_CR8","first-page":"22","volume":"12","author":"TH Belling","year":"1990","unstructured":"Belling, T. H. Sleep patterns in the horse. Equine Pract. 12, 22\u201327 (1990).","journal-title":"Equine Pract."},{"key":"34463_CR9","doi-asserted-by":"publisher","first-page":"630","DOI":"10.1111\/j.1939-1676.2008.0096.x","volume":"22","author":"DC Williams","year":"2008","unstructured":"Williams, D. C. et al. Qualitative and quantitative characteristics of the electroencephalogram in normal horses during spontaneous drowsiness and sleep. J. Vet. Intern. Med. 22, 630\u2013638 (2008).","journal-title":"J. Vet. Intern. Med."},{"key":"34463_CR10","doi-asserted-by":"publisher","first-page":"355","DOI":"10.1046\/j.1469-7580.2003.00166.x","volume":"202","author":"SO Schuurman","year":"2003","unstructured":"Schuurman, S. O., Kersten, W. & Weijs, W. A. The equine Hind limb is actively stabilized during standing. J. Anat. 202, 355\u2013362 (2003).","journal-title":"J. Anat."},{"key":"34463_CR11","doi-asserted-by":"publisher","first-page":"R1237","DOI":"10.1016\/j.cub.2017.10.026","volume":"27","author":"J Peever","year":"2017","unstructured":"Peever, J. & Fuller, P. M. The biology of REM sleep. Curr. Biol. 27, R1237\u2013R1248 (2017).","journal-title":"Curr. Biol."},{"key":"34463_CR12","first-page":"591","volume":"2","author":"A Dallaire","year":"1986","unstructured":"Dallaire, A., Rest & Behavior Veterinary Clin. North. America: Equine Pract. 2, 591\u2013607 (1986).","journal-title":"Veterinary Clin. North. America: Equine Pract."},{"key":"34463_CR13","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.jveb.2018.03.014","volume":"26","author":"ELT Chung","year":"2018","unstructured":"Chung, E. L. T., Khairuddin, N. H., Azizan, T. R. P. T. & Adamu, L. Sleeping patterns of horses in selected local horse stables in Malaysia. J. Vet. Behav. 26, 1\u20134 (2018).","journal-title":"J. Vet. Behav."},{"key":"34463_CR14","unstructured":"Kalus, M. Equine Sleep Behavior and Physiology Based on Polysomnographic Examinations (Ludwig-Maximilian University Munich, 2014)."},{"key":"34463_CR15","doi-asserted-by":"publisher","first-page":"723","DOI":"10.1016\/j.anbehav.2005.01.008","volume":"70","author":"SL Lima","year":"2005","unstructured":"Lima, S. L., Rattenborg, N. C., Lesku, J. A. & Amlaner, C. J. Sleeping under the risk of predation. Anim. Behav. 70, 723\u2013736 (2005).","journal-title":"Anim. Behav."},{"key":"34463_CR16","doi-asserted-by":"publisher","first-page":"R213","DOI":"10.1016\/j.cub.2024.01.061","volume":"34","author":"OI Lyamin","year":"2024","unstructured":"Lyamin, O. I., Siegel, J. M. & Sleep Giving it up to get it on. Curr. Biol. 34, R213\u2013R216 (2024).","journal-title":"Curr. Biol."},{"key":"34463_CR17","doi-asserted-by":"publisher","first-page":"144","DOI":"10.1016\/j.conb.2017.04.009","volume":"44","author":"OI Lyamin","year":"2017","unstructured":"Lyamin, O. I., Mukhametov, L. M. & Siegel, J. M. Sleep in the Northern fur seal. Curr. opin. neurobiol. 44, 144\u2013151 (2017).","journal-title":"Curr. opin. neurobiol."},{"key":"34463_CR18","doi-asserted-by":"publisher","first-page":"11","DOI":"10.1016\/j.jevs.2005.11.015","volume":"26","author":"P Raabymagle","year":"2006","unstructured":"Raabymagle, P. & Ladewig, J. Lying behavior in horses in relation to box size. J. Equine Vet. Sci. 26, 11\u201317 (2006).","journal-title":"J. Equine Vet. Sci."},{"key":"34463_CR19","doi-asserted-by":"publisher","first-page":"105229","DOI":"10.1016\/j.applanim.2021.105229","volume":"236","author":"L Greening","year":"2021","unstructured":"Greening, L., Downing, J., Amiouny, D., Lekang, L. & McBride, S. The effect of altering routine husbandry factors on sleep duration and memory consolidation in the horse. Appl. Anim. Behav. Sci. 236, 105229 (2021).","journal-title":"Appl. Anim. Behav. Sci."},{"key":"34463_CR20","doi-asserted-by":"publisher","first-page":"105715","DOI":"10.1016\/j.applanim.2022.105715","volume":"254","author":"L Kjellberg","year":"2022","unstructured":"Kjellberg, L., Sassner, H. & Yngvesson, J. Horses\u2019 resting behaviour in shelters of varying size compared with single boxes. Appl. Anim. Behav. Sci. 254, 105715 (2022).","journal-title":"Appl. Anim. Behav. Sci."},{"key":"34463_CR21","doi-asserted-by":"publisher","unstructured":"Suomala, H., Brotherus, I., H\u00e4nninen, L., Ternman, E. & Mykk\u00e4nen, A. K. Risk factors associated with owner-reported sleep disturbances in nordic horses. Equine Vet. J. 14560 https:\/\/doi.org\/10.1111\/evj.14560 (2025).","DOI":"10.1111\/evj.14560"},{"key":"34463_CR22","doi-asserted-by":"publisher","first-page":"334","DOI":"10.3390\/ani14020334","volume":"14","author":"\u00c2P Barbosa","year":"2024","unstructured":"Barbosa, \u00c2. P. et al. Sleep pattern interference in the cognitive performance of lusitano horses. Animals 14, 334 (2024).","journal-title":"Animals"},{"key":"34463_CR23","doi-asserted-by":"publisher","first-page":"167","DOI":"10.1038\/s41583-021-00428-w","volume":"22","author":"LQ Uddin","year":"2021","unstructured":"Uddin, L. Q. Cognitive and behavioural flexibility: neural mechanisms and clinical considerations. Nat. Rev. Neurosci. 22, 167\u2013179 (2021).","journal-title":"Nat. Rev. Neurosci."},{"key":"34463_CR24","doi-asserted-by":"publisher","first-page":"157","DOI":"10.1016\/j.cveq.2005.12.020","volume":"22","author":"JJ Bertone","year":"2006","unstructured":"Bertone, J. J. Excessive drowsiness secondary to recumbent sleep deprivation in two horses. Vet. Clin. North. Am. Equine Pract. 22, 157\u2013162 (2006).","journal-title":"Vet. Clin. North. Am. Equine Pract."},{"key":"34463_CR25","doi-asserted-by":"crossref","unstructured":"Bertone, J. J. Sleep and sleep disorders in horses. in Equine Neurology (eds Furr, M. & Reed, S.) 123\u2013129 (Wiley Blackwell, (2015).","DOI":"10.1002\/9781118993712.ch10"},{"key":"34463_CR26","doi-asserted-by":"publisher","first-page":"444","DOI":"10.1111\/j.1365-2869.2010.00823.x","volume":"19","author":"ML Haavisto","year":"2010","unstructured":"Haavisto, M. L. et al. Sleep restriction for the duration of a work week impairs multitasking performance: sleep restriction and multitasking. J. Sleep. Res. 19, 444\u2013454 (2010).","journal-title":"J. Sleep. Res."},{"key":"34463_CR27","doi-asserted-by":"publisher","first-page":"191","DOI":"10.1016\/j.aap.2018.02.013","volume":"126","author":"KA Honn","year":"2019","unstructured":"Honn, K. A., Hinson, J. M., Whitney, P. & Van Dongen, H. P. A. Cognitive flexibility: A distinct element of performance impairment due to sleep deprivation. Accid. Anal. Prev. 126, 191\u2013197 (2019).","journal-title":"Accid. Anal. Prev."},{"key":"34463_CR28","doi-asserted-by":"publisher","first-page":"1626309","DOI":"10.3389\/fnins.2025.1626309","volume":"19","author":"X Sun","year":"2025","unstructured":"Sun, X. et al. The effects of sleep deprivation on cognitive flexibility: a scoping review of outcomes and biological mechanisms. Front. Neurosci. 19, 1626309. https:\/\/doi.org\/10.3389\/fnins.2025.1626309 (2025).","journal-title":"Front. Neurosci."},{"key":"34463_CR29","doi-asserted-by":"publisher","first-page":"12","DOI":"10.1016\/j.neuroscience.2016.03.021","volume":"345","author":"A Izquierdo","year":"2017","unstructured":"Izquierdo, A., Brigman, J. L., Radke, A. K., Rudebeck, P. H. & Holmes, A. The neural basis of reversal learning: an updated perspective. Neuroscience 345, 12\u201326 (2017).","journal-title":"Neuroscience"},{"key":"34463_CR30","doi-asserted-by":"publisher","first-page":"41","DOI":"10.1016\/S0278-2626(03)00284-7","volume":"55","author":"L Clark","year":"2004","unstructured":"Clark, L., Cools, R. & Robbins, T. W. The neuropsychology of ventral prefrontal cortex: Decision-making and reversal learning. Brain Cogn. 55, 41\u201353 (2004).","journal-title":"Brain Cogn."},{"key":"34463_CR31","doi-asserted-by":"publisher","first-page":"1090","DOI":"10.1001\/archneurpsyc.1930.02220110256018","volume":"23","author":"IP Pavlov","year":"1930","unstructured":"Pavlov, I. P. Conditioned reflexes: an investigation of the physiological activity of the cerebral cortex. Arch. Neurol. Psychiatry. 23, 1090 (1930).","journal-title":"Arch. Neurol. Psychiatry"},{"key":"34463_CR32","first-page":"xxii","volume-title":"The Behavior of organisms, an Experimental analysis, Extended Edition xxii\u2013xxiii","author":"BF Skinner","year":"2021","unstructured":"Skinner, B. F. The behavior of organisms at 50. In The Behavior of organisms, an Experimental analysis, Extended Edition xxii\u2013xxiii (B. F. Skinner Foundation, 2021)."},{"key":"34463_CR33","doi-asserted-by":"publisher","first-page":"51","DOI":"10.1037\/h0062474","volume":"1","author":"HF Harlow","year":"1949","unstructured":"Harlow, H. F. The formation of learning sets. Psychol. Rev. 1, 51\u201365 (1949).","journal-title":"Psychol. Rev."},{"key":"34463_CR34","doi-asserted-by":"publisher","first-page":"92","DOI":"10.1038\/scientificamerican0165-92","volume":"212","author":"ME Bitterman","year":"1965","unstructured":"Bitterman, M. E. The evolution of intelligence. Sci. Am. 212, 92\u2013101 (1965).","journal-title":"Sci. Am."},{"key":"34463_CR35","doi-asserted-by":"crossref","unstructured":"Berg, E. L. & Silverman, J. L. Animal models of autism. in The Neuroscience of Autism 157\u2013196Academic Press, (2022).","DOI":"10.1016\/B978-0-12-816393-1.00010-5"},{"key":"34463_CR36","doi-asserted-by":"publisher","first-page":"215","DOI":"10.1080\/00221325.1962.10533590","volume":"100","author":"JM Warren","year":"1962","unstructured":"Warren, J. M. & Warren, H. B. Reversal learning by horse and raccoon. J. Genet. Psychol. 100, 215\u2013220 (1962).","journal-title":"J. Genet. Psychol."},{"key":"34463_CR37","unstructured":"Voith, V. L. Pattern discrimination, Learning Set formation, Memory retention, Spatial and Visual Reversal Learning by the Horse (The Ohio State University, 1975)."},{"key":"34463_CR38","doi-asserted-by":"publisher","first-page":"583","DOI":"10.2527\/jas1979.492583x","volume":"49","author":"J Fiske","year":"1979","unstructured":"Fiske, J. & Potter, G. Discrimination reversal learning in yearling horses. J. Anim. Sci. 49, 583\u2013588 (1979).","journal-title":"J. Anim. Sci."},{"key":"34463_CR39","doi-asserted-by":"publisher","first-page":"328","DOI":"10.1016\/j.applanim.2006.02.011","volume":"101","author":"TI Martin","year":"2006","unstructured":"Martin, T. I., Zentall, T. R. & Lawrence, L. Simple discrimination reversals in the domestic horse (Equus caballus): effect of discriminative stimulus modality on learning to learn. Appl. Anim. Behav. Sci. 101, 328\u2013338 (2006).","journal-title":"Appl. Anim. Behav. Sci."},{"key":"34463_CR40","doi-asserted-by":"publisher","first-page":"424","DOI":"10.1101\/lm.049510.119","volume":"26","author":"N Mancini","year":"2019","unstructured":"Mancini, N. et al. Reversal learning in drosophila larvae. Learn. Mem. 26, 424\u2013435 (2019).","journal-title":"Learn. Mem."},{"key":"34463_CR41","doi-asserted-by":"crossref","unstructured":"Meagher, R. K. et al. Effects of degree and timing of social housing on reversal learning and response to novel objects in dairy calves. PLoS One 10, e0132828 (2015).","DOI":"10.1371\/journal.pone.0132828"},{"key":"34463_CR42","doi-asserted-by":"crossref","unstructured":"Strobel, B. K., Schmidt, M. A., Harvey, D. O. & Davis, C. J. Image discrimination reversal learning is impaired by sleep deprivation in rats: cognitive rigidity or fatigue? Front Syst. Neurosci 16, 1052441 (2022).","DOI":"10.3389\/fnsys.2022.1052441"},{"key":"34463_CR43","doi-asserted-by":"publisher","first-page":"1012","DOI":"10.1016\/j.neuropharm.2012.07.025","volume":"63","author":"C Ineichen","year":"2012","unstructured":"Ineichen, C. et al. Establishing a probabilistic reversal learning test in mice: evidence for the processes mediating reward-stay and punishment-shift behaviour and for their modulation by serotonin. Neuropharmacology 63, 1012\u20131021 (2012).","journal-title":"Neuropharmacology"},{"key":"34463_CR44","doi-asserted-by":"publisher","first-page":"163","DOI":"10.1016\/0031-9384(69)90075-4","volume":"4","author":"CM Butter","year":"1969","unstructured":"Butter, C. M. Perseveration in extinction and in discrimination reversal tasks following selective frontal ablations in Macaca mulatta. Physiol. Behav. 4, 163\u2013171 (1969).","journal-title":"Physiol. Behav."},{"key":"34463_CR45","doi-asserted-by":"publisher","first-page":"1518","DOI":"10.1136\/jnnp.57.12.1518","volume":"57","author":"ET Rolls","year":"1994","unstructured":"Rolls, E. T., Hornak, J., Wade, D. & McGrath, J. Emotion-related learning in patients with social and emotional changes associated with frontal lobe damage. J. Neurol. Neurosurg. Psychiatry. 57, 1518\u20131524 (1994).","journal-title":"J. Neurol. Neurosurg. Psychiatry"},{"key":"34463_CR46","doi-asserted-by":"publisher","first-page":"896","DOI":"10.2527\/jas1977.454896x","volume":"46","author":"DD Kratzer","year":"1977","unstructured":"Kratzer, D. D., Netherland, W. M., Pulse, R. E. & Baker, J. P. Maze learning in quarter horses. J. Anim. Sci. 46, 896\u2013902 (1977).","journal-title":"J. Anim. Sci."},{"key":"34463_CR47","doi-asserted-by":"publisher","first-page":"2273","DOI":"10.1007\/s11357-013-9524-0","volume":"35","author":"P Mongillo","year":"2013","unstructured":"Mongillo, P. et al. Spatial reversal learning is impaired by age in pet dogs. Age (Omaha). 35, 2273\u20132282 (2013).","journal-title":"Age (Omaha)"},{"key":"34463_CR48","doi-asserted-by":"publisher","first-page":"267","DOI":"10.1016\/S0168-1591(97)00006-3","volume":"54","author":"B Flannery","year":"1997","unstructured":"Flannery, B. Relational discrimination learning in horses. Appl. Anim. Behav. Sci. 54, 267\u2013280 (1997).","journal-title":"Appl. Anim. Behav. Sci."},{"key":"34463_CR49","doi-asserted-by":"publisher","first-page":"103552","DOI":"10.1016\/j.jevs.2021.103552","volume":"100","author":"L Vigouroux","year":"2022","unstructured":"Vigouroux, L., Jolivald, A., Ijichi, C. & Yarnell, K. 89 learning ability and physiological stress response of horses (Equus caballus) undergoing discrimination and reversal learning tasks using a touch screen. J. Equine Vet. Sci. 100, 103552 (2022).","journal-title":"J. Equine Vet. Sci."},{"key":"34463_CR50","doi-asserted-by":"publisher","first-page":"18","DOI":"10.1016\/j.applanim.2017.02.020","volume":"190","author":"AN McLean","year":"2017","unstructured":"McLean, A. N. & Christensen, J. W. The application of learning theory in horse training. Appl. Anim. Behav. Sci. 190, 18\u201327 (2017).","journal-title":"Appl. Anim. Behav. Sci."},{"key":"34463_CR51","doi-asserted-by":"publisher","first-page":"157","DOI":"10.1016\/S0168-1591(96)01157-4","volume":"53","author":"BKF Sappington","year":"1997","unstructured":"Sappington, B. K. F., McCall, C. A., Coleman, D. A., Kuhlers, D. L. & Lishak, R. S. A preliminary study of the relationship between discrimination reversal learning and performance tasks in yearling and 2-year-old horses. Appl. Anim. Behav. Sci. 53, 157\u2013166 (1997).","journal-title":"Appl. Anim. Behav. Sci."},{"key":"34463_CR52","doi-asserted-by":"crossref","unstructured":"Samhita, L. & Gross, H. J. The \u2018Clever Hans phenomenon\u2019 revisited. Commun Integr. Biol 6, e27122 (2013).","DOI":"10.4161\/cib.27122"},{"key":"34463_CR53","unstructured":"Kaimio, T. & Tallberg, M. Hevosen k\u00e4ytt\u00e4ytyminen (Behaviour of the horse). in Hevosen Kanssa 108\u2013109 (WSOY, (2012)."},{"key":"34463_CR54","doi-asserted-by":"publisher","first-page":"1715","DOI":"10.2527\/2003.8171715x","volume":"81","author":"CA Hall","year":"2003","unstructured":"Hall, C. A., Cassaday, H. J. & Derrington, A. M. The effect of stimulus height on visual discrimination in horses. J. Anim. Sci. 81, 1715\u20131720 (2003).","journal-title":"J. Anim. Sci."},{"key":"34463_CR55","doi-asserted-by":"publisher","first-page":"387","DOI":"10.1016\/j.beproc.2008.02.003","volume":"78","author":"TL Blackmore","year":"2008","unstructured":"Blackmore, T. L., Foster, T. M., Sumpter, C. E. & Temple, W. An investigation of colour discrimination with horses (Equus caballus). Behav. Process. 78, 387\u2013396 (2008).","journal-title":"Behav. Process."},{"key":"34463_CR56","doi-asserted-by":"crossref","unstructured":"Tomonaga, M. et al. A horse\u2019s eye view: size and shape discrimination compared with other mammals. Biol Lett 11, 20150701 (2015).","DOI":"10.1098\/rsbl.2015.0701"},{"key":"34463_CR57","unstructured":"Waring, G. H. Horse Behavior 175\u2013223 (Noyes, 1983)."},{"key":"34463_CR58","unstructured":"McDonnell, S. A Practical Field Guide To Horse Behavior: the Equid Ethogram (A Division of the Blood-Horse, Inc., 2003)."},{"key":"34463_CR59","doi-asserted-by":"crossref","unstructured":"Wilson, R. C., Shenhav, A., Straccia, M. & Cohen, J. D. The 85% Rule for optimal learning. Nat Commun 10, 4646 (2019).","DOI":"10.1038\/s41467-019-12552-4"},{"key":"34463_CR60","doi-asserted-by":"crossref","unstructured":"Buechel, S. D., Boussard, A., Kotrschal, A. & van Der Bijl, W. & Kolm, N. Brain size affects performance in a reversal-learning test. Proceedings of the Royal Society B: Biological Sciences 285, (2018).","DOI":"10.1098\/rspb.2017.2031"},{"key":"34463_CR61","doi-asserted-by":"crossref","unstructured":"Pannewitz, L. & Loftus, L. Frustration in horses: investigating expert opinion on behavioural indicators and causes using a Delphi consultation. Appl Anim. Behav. Sci 258, 105818 (2023).","DOI":"10.1016\/j.applanim.2022.105818"},{"key":"34463_CR62","doi-asserted-by":"crossref","unstructured":"Hartman, N. & Greening, L. M. A preliminary study investigating the influence of auditory stimulation on the occurrence of nocturnal equine Sleep-Related behavior in stabled horses. J Equine Vet. Sci 82, 102782 (2019).","DOI":"10.1016\/j.jevs.2019.07.003"},{"key":"34463_CR63","doi-asserted-by":"publisher","first-page":"117","DOI":"10.1055\/s-2005-867080","volume":"25","author":"JS Durmer","year":"2005","unstructured":"Durmer, J. S. & Dinges, D. F. Neurocognitive consequences of sleep deprivation. Semin Neurol. 25, 117\u2013129 (2005).","journal-title":"Semin Neurol."},{"key":"34463_CR64","doi-asserted-by":"publisher","first-page":"6645","DOI":"10.1038\/s41598-022-10162-7","volume":"12","author":"RD Johnsson","year":"2022","unstructured":"Johnsson, R. D. et al. Sleep loss impairs cognitive performance and alters song output in Australian magpies. Sci. Rep. 12, 6645 (2022).","journal-title":"Sci. Rep."},{"key":"34463_CR65","doi-asserted-by":"publisher","first-page":"656","DOI":"10.1016\/j.beproc.2018.04.004","volume":"157","author":"J Pinheiro-da-Silva","year":"2018","unstructured":"Pinheiro-da-Silva, J., Tran, S. & Luchiari, A. C. Sleep deprivation impairs cognitive performance in zebrafish: A matter of fact? Behav. Process. 157, 656\u2013663 (2018).","journal-title":"Behav. Process."},{"key":"34463_CR66","doi-asserted-by":"publisher","first-page":"697","DOI":"10.1007\/s10071-019-01266-1","volume":"22","author":"DR Samson","year":"2019","unstructured":"Samson, D. R., Vining, A. & Nunn, C. L. Sleep influences cognitive performance in lemurs. Anim. Cogn. 22, 697\u2013706 (2019).","journal-title":"Anim. Cogn."},{"key":"34463_CR67","unstructured":"Skinner, B. F. The Behavior of Organisms: an Experimental analysis (B. F. Skinner Foundation, 1939)."},{"key":"34463_CR68","doi-asserted-by":"publisher","first-page":"241","DOI":"10.1016\/0168-1591(94)90065-5","volume":"40","author":"CJ Sherry","year":"1994","unstructured":"Sherry, C. J., Walters, T. J. & Rodney, G. G. Henry P.J. Behavioral Chaining in the goat (Capra hircus). Appl. Anim. Behav. Sci. 40, 241\u2013251 (1994).","journal-title":"Appl. Anim. Behav. Sci."},{"key":"34463_CR69","doi-asserted-by":"publisher","first-page":"193","DOI":"10.1037\/h0054367","volume":"57","author":"BF Skinner","year":"1950","unstructured":"Skinner, B. F. Are theories of learning necessary? Psychol. Rev. 57, 193\u2013216 (1950).","journal-title":"Psychol. Rev."},{"key":"34463_CR70","doi-asserted-by":"publisher","first-page":"22529","DOI":"10.1038\/s41598-022-26991-5","volume":"12","author":"S Junttila","year":"2022","unstructured":"Junttila, S. et al. Breed differences in social cognition, inhibitory control, and Spatial problem-solving ability in the domestic dog (Canis familiaris). Sci. Rep. 12, 22529. https:\/\/doi.org\/10.1038\/s41598-022-26991-5 (2022).","journal-title":"Sci. Rep."},{"key":"34463_CR71","doi-asserted-by":"crossref","unstructured":"Martin, P. & Bateson, P. Measuring Behaviour an Introductory Guide (Cambridge University, 2007).","DOI":"10.1017\/CBO9780511810893"},{"key":"34463_CR72","doi-asserted-by":"publisher","first-page":"41","DOI":"10.1086\/285786","volume":"146","author":"J Stamps","year":"1995","unstructured":"Stamps, J. Motor learning and the value of familiar space. Am. Nat. 146, 41\u201358 (1995).","journal-title":"Am. Nat."},{"key":"34463_CR73","doi-asserted-by":"publisher","first-page":"16557","DOI":"10.1038\/s41598-017-16729-z","volume":"7","author":"P Baragli","year":"2017","unstructured":"Baragli, P. et al. Consistency and flexibility in solving Spatial tasks: different horses show different cognitive styles. Sci. Rep. 7, 16557 (2017).","journal-title":"Sci. Rep."},{"key":"34463_CR74","doi-asserted-by":"publisher","first-page":"1001","DOI":"10.1007\/s10071-013-0648-5","volume":"16","author":"M Valenchon","year":"2013","unstructured":"Valenchon, M., L\u00e9vy, F., G\u00f3recka-Bruzda, A., Calandreau, L. & Lansade, L. Characterization of long-term memory, resistance to extinction, and influence of temperament during two instrumental tasks in horses. Anim. Cogn. 16, 1001\u20131006 (2013).","journal-title":"Anim. Cogn."}],"container-title":["Scientific Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-34463-9","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-34463-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-34463-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T16:12:47Z","timestamp":1781626367000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.nature.com\/articles\/s41598-025-34463-9"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,6]]},"references-count":74,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,12]]}},"alternative-id":["34463"],"URL":"https:\/\/doi.org\/10.1038\/s41598-025-34463-9","relation":{},"ISSN":["2045-2322"],"issn-type":[{"value":"2045-2322","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,6]]},"assertion":[{"value":"27 June 2025","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"29 December 2025","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"6 January 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare no competing interests.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"4265"}}