Cross-modal recognition in domestic horses (Equus caballus)

Centre for Mammal Vocal Communication Research, Department of Psychology, School of Life Sciences, University of Sussex, Brighton BN1 9QH, United Kingdom.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 01/2009; 106(3):947-51. DOI: 10.1073/pnas.0809127105
Source: PubMed


Individual recognition is considered a complex process and, although it is believed to be widespread across animal taxa, the cognitive mechanisms underlying this ability are poorly understood. An essential feature of individual recognition in humans is that it is cross-modal, allowing the matching of current sensory cues to identity with stored information about that specific individual from other modalities. Here, we use a cross-modal expectancy violation paradigm to provide a clear and systematic demonstration of cross-modal individual recognition in a nonhuman animal: the domestic horse. Subjects watched a herd member being led past them before the individual went of view, and a call from that or a different associate was played from a loudspeaker positioned close to the point of disappearance. When horses were shown one associate and then the call of a different associate was played, they responded more quickly and looked significantly longer in the direction of the call than when the call matched the herd member just seen, an indication that the incongruent combination violated their expectations. Thus, horses appear to possess a cross-modal representation of known individuals containing unique auditory and visual/olfactory information. Our paradigm could provide a powerful way to study individual recognition across a wide range of species.

Download full-text


Available from: David Reby,
  • Source
    • "Such comparisons have shown a lack of certain skills in species living in less complex social systems compared with species in more complex systems (Anderson, 1996; Bond et al., 2003). A growing body of literature indicates that certain cognitive skills that were previously assigned to 'social intelligence', are present also in species living in less complex social systems (Davis, 1992; Proops et al., 2009; Weiß et al., 2010; Wilkinson et al., 2010; Sheehan & Tibbetts, 2011). This hints towards the possibility that these skills are part of a 'general intelligence', the evolutionary origins of which are unlikely to be derived from social challenges (Healy & Rowe, 2007). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The social intelligence hypothesis links the evolution of exceptional cognitive skills to the requirements of complex social systems. Empirical evidence of a connection between cognitive skills and social behaviour on an individual level is lacking. I investigated how cognitive performance in carrion crows correlates with social behaviour. Social behaviour was observed and crows were tested in four tasks previously published elsewhere: qualitative exchange, quantity preference, inequity aversion, heterospecific recognition. I describe correlations between an individuals’ involvement in affiliative and aggressive encounters and performance during these different cognitive tasks. For example, individuals performing better in the qualitative exchange task received more approaches and affiliative interactions. There was a correlation between birds choosing higher quantities during testing and their propensity to initiate aggressive and affiliative interactions with others. Overall these results show a link between social behaviour and individual performance in cognitive tasks.
    Behaviour 10/2014; 152(5). DOI:10.1163/1568539X-00003245 · 1.23 Impact Factor
  • Source
    • "In contrast, the placebo group demonstrated increased attention to the environment (HA, head away from the panels during total and incorrect choices in the third session, with the test), or the handler (P, pushing during correct choices in the first and third sessions with a significant interaction between treatment and duration). Various authors (Mader and Price, 1980; McCall et al., 1981; Krueger and Heinze, 2008; Maros et al., 2008; Proops et al., 2009; Hanggi and Ingersoll, 2009; Proops and McComb, 2010; Krueger et al., 2010; Baragli et al., 2011) have described complex and sophisticated learning abilities in horses. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Modern day horse-human relationships entail different types of sport and riding activities, which all require learning. In evaluating the interaction between learning and emotions, studying normal coping strategies or adaptive responses to the surroundings is critical. 34 horses were involved in a cognitive test, in the absence of physical effort, to analyze performance, as well as physiological and behavioral responses related to learning, memorization and recall, associated to the capacity to reverse a learned model. Synthetic Equine Appeasing Pheromone (EAP) was used in 17 horses in order to modulate their emotional state and evaluate differences in cognitive-emotional response during cognitive effort in comparison to the control group (placebo group). Both groups showed statistically significant changes in heart rate during the test, indicating emotional and physio-cognitive activation. The EAP group produced fewer errors and made more correct choices, showing behaviors related to increased attention, with less influence from environmental stimuli. The capacity to learn to learn, as shown in the bibliography, allows animals to establish conceptual learning, when a normal or positive emotional state (in this case modulated by semiochemicals) is used to control limbic system activation and, consequently, decrease stressful/fearful reactions, resulting in better learning capacities during the cognitive test.
    Behavioural Processes 05/2014; 106. DOI:10.1016/j.beproc.2014.05.004 · 1.57 Impact Factor
  • Source
    • "Looking represents the manifestation of selective attention required to appraise an object or situation (Proops et al., 2009). In this study sample, the looking parameters did not vary substantially with age in the Stress Test. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In humans the expression of emotions varies with aging, but for domestic animals we have little information on this subject. Our aim was to verify the influence of aging (life experience) on the expression of emotions in horses (Equus caballus) in reaction to a stressful stimulus. A total of 98 horses were subjected to the sudden inflation of a balloon in a familiar environment for a period of 5 min, on the assumption that this would induce a negative state. When the balloon was inflated, heart rate variability as an indicator of stress response was monitored. Behaviour related to emotional expression (latency of onset, frequency and length of looking and exploration, frequency of avoidance) was also monitored. The younger horses showed a significantly higher frequency of avoidance as well as greater exploratory activity, while the older subjects were less behaviourally responsive and showed a shift toward control by the sympathetic nervous system, as indicated by lower heart rate variability. The results suggest that aging influences the behaviour and physiology of emotional expression to stressful stimuli in horses. Knowing the effect of aging on stress response could be a critical factor in understanding equine welfare and the development of behavioural patterns.
    Behaviour 03/2014; 151(11):1513–1533. DOI:10.1163/1568539X-00003197 · 1.23 Impact Factor
Show more