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Li, W., Howard, J. D., Parrish, T. B., & Gottfried, J. A. (2008). Aversive Learning Enhances Perceptual and Cortical Discrimination of Indiscriminable Odor Cues. Science, 319(5871), 1842–1845.
Abstract: Learning to associate sensory cues with threats is critical for minimizing aversive experience. The ecological benefit of associative learning relies on accurate perception of predictive cues, but how aversive learning enhances perceptual acuity of sensory signals, particularly in humans, is unclear. We combined multivariate functional magnetic resonance imaging with olfactory psychophysics to show that initially indistinguishable odor enantiomers (mirror-image molecules) become discriminable after aversive conditioning, paralleling the spatial divergence of ensemble activity patterns in primary olfactory (piriform) cortex. Our findings indicate that aversive learning induces piriform plasticity with corresponding gains in odor enantiomer discrimination, underscoring the capacity of fear conditioning to update perceptual representation of predictive cues, over and above its well-recognized role in the acquisition of conditioned responses. That completely indiscriminable sensations can be transformed into discriminable percepts further accentuates the potency of associative learning to enhance sensory cue perception and support adaptive behavior.
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Dreber, A., Rand, D. G., Fudenberg, D., & Nowak, M. A. (2008). Winners don/'t punish. Nature, 452(7185), 348–351.
Abstract: A key aspect of human behaviour is cooperation1, 2, 3, 4, 5, 6, 7. We tend to help others even if costs are involved. We are more likely to help when the costs are small and the benefits for the other person significant. Cooperation leads to a tension between what is best for the individual and what is best for the group. A group does better if everyone cooperates, but each individual is tempted to defect. Recently there has been much interest in exploring the effect of costly punishment on human cooperation8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23. Costly punishment means paying a cost for another individual to incur a cost. It has been suggested that costly punishment promotes cooperation even in non-repeated games and without any possibility of reputation effects10. But most of our interactions are repeated and reputation is always at stake. Thus, if costly punishment is important in promoting cooperation, it must do so in a repeated setting. We have performed experiments in which, in each round of a repeated game, people choose between cooperation, defection and costly punishment. In control experiments, people could only cooperate or defect. Here we show that the option of costly punishment increases the amount of cooperation but not the average payoff of the group. Furthermore, there is a strong negative correlation between total payoff and use of costly punishment. Those people who gain the highest total payoff tend not to use costly punishment: winners don't punish. This suggests that costly punishment behaviour is maladaptive in cooperation games and might have evolved for other reasons.
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Milinski, M., & Rockenbach, B. (2008). Human behaviour: Punisher pays. Nature, 452(7185), 297–298.
Abstract: The tendency of humans to punish perceived free-loaders, even at a cost to themselves, is an evolutionary puzzle: punishers perish, and those who benefit the most are those who have never punished at all.
Humans are champions of cooperation. Reciprocity – the idea that, if I help you this time, you'll help me next time1 – is a secret of our success.
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Schmied, C., Waiblinger, S., Scharl, T., Leisch, F., & Boivin, X. (2008). Stroking of different body regions by a human: Effects on behaviour and heart rate of dairy cows. Appl. Anim. Behav. Sci., 109(1), 25–38.
Abstract: From observations of intra-specific social grooming in cattle and studies on human stroking in other species, we hypothesised that cows' reactions to human stroking differ depending on the body regions being stroked. Moreover, we tested, whether cows `reactions to stroking change with the animals' experience of stroking. Sixty dairy cows were stroked in three different body regions, i.e. the withers, W, neck ventral, NV (both licked often in social grooming) and the lateral chest, LC (licked rarely), in a balanced order during 10-min sessions. Behavioural reactions and heart rate during stroking as well as reactions to the human just after stroking were recorded. Two test sessions were carried out with 3 weeks of treatment in-between. During this period, the cows were randomly allocated to four treatment groups: three groups received 5 min of daily stroking in either W, NV or LC and the last one (control group) was exposed to simple human presence. During stroking W and NV, cows showed longer neck stretching and ear hanging than during stroking LC (P < 0.001). Moreover, ear hanging was shown longer when W was stroked as compared to NV (P < 0.001), but neck stretching was observed longer during stroking NV as compared to W only after the treatment period (P < 0.01). In the first test session, more animals showed head shaking and head throwing during stroking W and NV than LC (P < 0.01), whereas in the second test session these behaviours were observed only in few animals. In the first test session heart rate was higher during stroking W than the other body regions (P <= 0.01). In the second test session, the lowest heart rate was found during stroking NV (P < 0.05). Finally, contact with the experimenter following stroking differed for the three body regions stroked in both test sessions (first: P = 0.06, second: P < 0.01); contact was shortest for LC. When comparing both test sessions, stretching the neck and ear hanging increased (P < 0.001), while head shaking and head throwing decreased (P < 0.05); there was no difference for heart rate and contact with the experimenter. The four treatments had no influence on reactions to stroking. To conclude, stroking of body regions often licked during social grooming led to more responses than stroking the one licked rarely. Some reactions, such as stretching the neck, are also observed during social licking. This suggests that cows may in part perceive human stroking of body regions often licked similarly to social licking. This knowledge could be of interest for an improvement in quality of human-cattle interactions.
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Krueger, K., & Flauger, B. (2008). Social feeding decisions in horses (Equus caballus). Behav. Process., 78(1), 76–83.
Abstract: Like many other herbivores, in a natural environment equids feed on rather evenly distributed resources. However, the vegetation in their vast habitats constantly changes. If food is plentiful only little competition occurs over food, and in non-competitive situations domestic horses tend to return to the same feeding site until it is overgrazed. In contrast, they compete over limited food for which the social status of the individuals appears to be important. Especially in ruminants several studies have proved an influence of social organisations, rank, sex and the depletion of feeding sites on the feeding behaviour of individuals. However, it is not yet understood whether and how social aspects affect horses“ feeding decisions. Curiosity about the influence of social rank on the horses” feeding decisions between two, equally with high-quality surplus food-filled buckets placed in different social feeding conditions, led us to create the test below. The observer horses were alternately tested with a dominant and a subordinate demonstrator placed in one of the three different positions. We conclude that domestic horses use social cognition and strategic decision making in order to decide where to feed in a social feeding situation. When possible they tend to return to the same, continuously supplied feeding site and switch to an “avoidance tendency” in the presence of dominant horses or when another horse is already feeding there. Thus, the social rank and the position of conspecifics affect the feeding strategy of horses.
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Maros, K., Gácsi, M., & Miklósi, Á. (2008). Comprehension of human pointing gestures in horses ( Equus caballus ). Anim. Cogn., 11(3), 457–466.
Abstract: Abstract Twenty domestic horses (Equus caballus) were tested for their ability to rely on different human gesticular cues in a two-way object choice task. An experimenter hid food under one of two bowls and after baiting, indicated the location of the food to the subjects by using one of four different cues. Horses could locate the hidden reward on the basis of the distal dynamic-sustained, proximal momentary and proximal dynamic-sustained pointing gestures but failed to perform above chance level when the experimenter performed a distal momentary pointing gesture. The results revealed that horses could rely spontaneously on those cues that could have a stimulus or local enhancement effect, but the possible comprehension of the distal momentary pointing remained unclear. The results are discussed with reference to the involvement of various factors such as predisposition to read human visual cues, the effect of domestication and extensive social experience and the nature of the gesture used by the experimenter in comparative investigations.
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Krueger, K. (2008). Social Ecology of Horses. In j. Korb and J. Heinze (Ed.), Ecology of Social Evolution (pp. 195–206). Heidelberg: Springer Verlag.
Abstract: Horses (Equidae ) are believed to clearly demonstrate the links between ecology and social organization. Their social cognitive abilities enable them to succeed in many different environments, including those provided for them by humans, or the ones domestic horses encounter when escaping from their human care takers. Living in groups takes different shapes in equids. Their aggregation and group cohesion can be explained by Hamilton“s selfish herd theory. However, when an individual joins and to which group it joins appears to be an active individual decision depending on predation pressure, intra group harassment and resource availability. The latest research concerning the social knowledge horses display in eavesdropping experiments affirms the need for an extension of simple herd concepts in horses for a cognitive component. Horses obviously realize the social composition of their group and determine their own position in it. The horses exceedingly flexible social behavior demands for explanations about the cognitive mechanisms, which allow them to make individual decisions. ”Ecology conditions like those that favour the evolution of open behavioural programs sometimes also favour the evolution of the beginnings of consciousness, by favouring conscious choice. Or in other words, consciousness originates with the choice that are left open by open behavioural programs." Popper (1977)
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O'Grady, S. E. (2008). Basic farriery for the performance horse. Vet Clin North Am Equine Pract, 24(1), 203–218.
Abstract: Proper farriery promotes a healthy functional foot and biomechanical efficiency and prevents lameness. Because the equine veterinarian is responsible for the soundness of the horse, a working knowledge of farriery becomes essential. A thorough knowledge of traditional horseshoeing enables the veterinarian to interact with the farrier at the farrier's level; this ultimately enhances and promotes quality hoof care. This article focuses on fundamental farriery and recognizing subtle changes in hoof conformation that can be used to preserve the integrity of the hoof capsule, along with the structures enclosed within, and thus prevent lameness in the performance horse.
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Weishaupt, M. A. (2008). Adaptation strategies of horses with lameness. Vet Clin North Am Equine Pract, 24(1), 79–100.
Abstract: The skill to diagnose lameness in horses is paramount for every equine practitioner. Early recognition of locomotor deficiencies plays a central role in sports medicine management, preventing deterioration of the disease or catastrophic injuries. Horses use characteristic compensatory movements of specific body parts to decrease loading of the affected limb. This article describes the underlying changes in intra- and interlimb coordination and the resulting load redistribution between the limbs. This enables the practitioner to better understand the changes in movement associated with lameness.
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IESM 2008 Test. (2008). Presentation without Fulltext. In IESM Conference Volume (Vol. 1, pp. 5–10).
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