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Plotnik, J., Nelson, P. A., & de Waal, F. B. M. (2003). Visual field information in the face perception of chimpanzees (Pan troglodytes). Ann N Y Acad Sci, 1000, 94–98.
Abstract: Evidence for a visual field advantage (VFA) in the face perception of chimpanzees was investigated using a modification of a free-vision task. Four of six chimpanzee subjects previously trained on a computer joystick match-to-sample paradigm were able to distinguish between images of neutral face chimeras consisting of two left sides (LL) or right sides (RR) of the face. While an individual's ability to make this distinction would be unlikely to determine their suitability for the VFA tests, it was important to establish that distinctive information was available in test images. Data were then recorded on their choice of the LL vs. RR chimera as a match to the true, neutral image; a bias for one of these options would indicate an hemispatial visual field advantage. Results suggest that chimpanzees, unlike humans, do not exhibit a left visual field advantage. These results have important implications for studies on laterality and asymmetry in facial signals and their perception in primates.
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Riedel, J., Buttelmann, D., Call, J., & Tomasello, M. (2006). Domestic dogs (Canis familiaris) use a physical marker to locate hidden food. Anim. Cogn., 9(1), 27–35.
Abstract: Dogs can use the placement of an arbitrary marker to locate hidden food in an object-choice situation. We tested domestic dogs (Canis familiaris) in three studies aimed at pinning down the relative contributions of the human's hand and the marker itself. We baited one of two cups (outside of the dogs' view) and gave the dog a communicative cue to find the food. Study 1 systematically varied dogs' perceptual access to the marker placing event, so that dogs saw either the whole human, the hand only, the marker only, or nothing. Follow-up trials investigated the effect of removing the marker before the dog's choice. Dogs used the marker as a communicative cue even when it had been removed prior to the dog's choice and attached more importance to this cue than to the hand that placed it although the presence of the hand boosted performance when it appeared together with the marker. Study 2 directly contrasted the importance of the hand and the marker and revealed that the effect of the marker diminished if it had been associated with both cups. In contrast touching both cups with the hand had no effect on performance. Study 3 investigated whether the means of marker placement (intentional or accidental) had an effect on dogs' choices. Results showed that dogs did not differentiate intentional and accidental placing of the marker. These results suggest that dogs use the marker as a genuine communicative cue quite independently from the experimenter's actions.
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Nielsen, M., Collier-Baker, E., Davis, J. M., & Suddendorf, T. (2005). Imitation recognition in a captive chimpanzee (Pan troglodytes). Anim. Cogn., 8(1), 31–36.
Abstract: This study investigated the ability of a captive chimpanzee (Pan troglodytes) to recognise when he is being imitated. In the experimental condition of test 1a, an experimenter imitated the postures and behaviours of the chimpanzee as they were being displayed. In three control conditions the same experimenter exhibited (1) actions that were contingent on, but different from, the actions of the chimpanzee, (2) actions that were not contingent on, and different from, the actions of the chimpanzee, or (3) no action at all. The chimpanzee showed more “testing” sequences (i.e., systematically varying his actions while oriented to the imitating experimenter) and more repetitive behaviour when he was being imitated, than when he was not. This finding was replicated 4 months later in test 1b. When the experimenter repeated the same actions she displayed in the experimental condition of test 1a back to the chimpanzee in test 2, these actions now did not elicit those same testing sequences or repetitive behaviours. However, a live imitation condition did. Together these results provide the first evidence of imitation recognition in a nonhuman animal.
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Fichtel, C. (2004). Reciprocal recognition of sifaka ( Propithecus verreauxi verreauxi) and redfronted lemur ( Eulemur fulvus rufus) alarm calls. Anim. Cogn., 7(1), 45–52.
Abstract: Redfronted lemurs ( Eulemur fulvus rufus) and Verreaux's sifakas ( Propithecus verreauxi verreauxi) occur sympatrically in western Madagascar. Both species exhibit a so-called mixed alarm call system with functionally referential alarm calls for raptors and general alarm calls for carnivores and raptors. General alarm calls also occur in other contexts associated with high arousal, such as inter-group encounters. Field playback experiments were conducted to investigate whether interspecific recognition of alarm calls occurs in both species, even though the two species rarely interact. In a crossed design, redfronted lemur and sifaka alarm calls were broadcast to individuals of both species, using the alarm call of chacma baboons ( Papio cynocephalus) as a control. Both species responded with appropriate escape strategies and alarm calls after playbacks of heterospecific aerial alarm calls. Similarly, they reacted appropriately to playbacks of heterospecific general alarm calls. Playbacks of baboon alarm calls elicited no specific responses in either lemur species, indicating that an understanding of interspecific alarm calls caused the responses and not alarm calls in general. Thus, the two lemur species have an understanding of each other's aerial as well as general alarm calls, suggesting that even in species that do not form mutualistic associations and rarely interact, common predator pressure has been sufficient for the development of heterospecific call recognition.
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Hare, J. F., Sealy, S. G., Underwood, T. J., Ellison, K. S., & Stewart, R. L. M. (2003). Evidence of self-referent phenotype matching revisited: airing out the armpit effect. Anim. Cogn., 6(1), 65–68.
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Mateo, J. M., & Johnston, R. E. (2003). Kin recognition by self-referent phenotype matching: weighing the evidence. Anim. Cogn., 6(1), 73–76.
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Hauber, M. E., & Sherman, P. W. (2003). Designing and interpreting experimental tests of self-referent phenotype matching. Anim. Cogn., 6(1), 69–71.
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Soproni, K., Miklósi, Á., Topál, J., & Csányi, V. (2002). Dogs' (Canis familiaris) responsiveness to human pointing gestures. J Comp Psychol, 116(1), 27–34.
Abstract: In a series of 3 experiments, dogs (Canis familiaris) were presented with variations of the human pointing gesture: gestures with reversed direction of movement, cross-pointing, and different arm extensions. Dogs performed at above chance level if they could see the hand (and index finger) protruding from the human body contour. If these minimum requirements were not accessible, dogs still could rely on the body position of the signaler. The direction of movement of the pointing arm did not influence the performance. In summary, these observations suggest that dogs are able to rely on relatively novel gestural forms of the human communicative pointing gesture and that they are able to comprehend to some extent the referential nature of human pointing.
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Holekamp, K. E., Sakai, S. T., & Lundrigan, B. L. (2007). Social intelligence in the spotted hyena (Crocuta crocuta). Philos Trans R Soc Lond B Biol Sci, 362(1480), 523–538.
Abstract: If the large brains and great intelligence characteristic of primates were favoured by selection pressures associated with life in complex societies, then cognitive abilities and nervous systems with primate-like attributes should have evolved convergently in non-primate mammals living in large, elaborate societies in which social dexterity enhances individual fitness. The societies of spotted hyenas are remarkably like those of cercopithecine primates with respect to size, structure and patterns of competition and cooperation. These similarities set an ideal stage for comparative analysis of social intelligence and nervous system organization. As in cercopithecine primates, spotted hyenas use multiple sensory modalities to recognize their kin and other conspecifics as individuals, they recognize third-party kin and rank relationships among their clan mates, and they use this knowledge adaptively during social decision making. However, hyenas appear to rely more intensively than primates on social facilitation and simple rules of thumb in social decision making. No evidence to date suggests that hyenas are capable of true imitation. Finally, it appears that the gross anatomy of the brain in spotted hyenas might resemble that in primates with respect to expansion of frontal cortex, presumed to be involved in the mediation of social behaviour.
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Palmer, M. E., Calve, M. R., & Adamo, S. A. (2006). Response of female cuttlefish Sepia officinalis (Cephalopoda) to mirrors and conspecifics: evidence for signaling in female cuttlefish. Anim. Cogn., 9(2), 151–155.
Abstract: Cuttlefish have a large repertoire of body patterns that are used for camouflage and interspecific signaling. Intraspecific signaling by male cuttlefish has been well documented but studies on signaling by females are lacking. We found that females displayed a newly described body pattern termed Splotch toward their mirror image and female conspecifics, but not to males, prey or inanimate objects. Female cuttlefish may use the Splotch body pattern as an intraspecific signal, possibly to reduce agonistic interactions. The ability of females to produce a consistent body pattern in response to conspecifics and mirrors suggests that they can recognize same-sex conspecifics using visual cues, despite the lack of sexual dimorphism visible to human observers.
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