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Clayton NS, Griffiths DP, Emery NJ, & Dickinson A. (2001). Elements of episodic-like memory in animals. Philos. Trans. R. Soc. Lond. B Biol. Sci., 356, 1483.
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Johnson, C. M. (2001). Distributed primate cognition: a review. Anim. Cogn., 3(4), 167–183.
Abstract: A model of “distributed cognition” is contrasted with the “mental representation” model exemplified by Tomasello and Call's Primate Cognition. Rather than using behavior as a basis for inferences to invisible mental events such as intentions, the distributed approach treats communicative interactions as, themselves, directly observable cognitive events. Similar to a Vygotskian approach, this model characterizes cognition as “co-constructed” by the participants. This approach is thus particularly suitable for studying primates (including humans), whose reliance on multiparty negotiations can undermine the researcher's ability to extrapolate from observable outcomes back to individual intentions. Detailed (e.g., frame-by-frame) analyses of such interactions reveal cross-species differences in the relevant media of information flow (e.g., behavioral coordination, relative gaze) as well as in the flexibility and complexity of the trajectories observed. Plus, with its focus on dynamics, the distributed approach is especially useful for modeling developmental and evolutionary processes. In discussing enculturation and the ontogeny of imitation, its emphasis is on changes in how expert and novice participate in such events, rather than how either may represent them. Primate cognitive evolution is seen as involving changes in context sensitivity, multi-tasking, and the coordination of social attention. Humans in particular – in, especially, the context of teaching – are seen as having specialized in linking co-perception with the refined sensory-motor coordination that enables them to translate observed behavior into strategically similar action. Highlighting the continuity between human and nonhuman development, this promising, complementary model enables us to tap the richness of micro-ethology as a cognitive science.
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Snowdon, C. T. (2001). Social processes in communication and cognition in callitrichid monkeys: a review. Anim. Cogn., 4(3), 247–257.
Abstract: Studies of vocal development in nonhuman primates have found little evidence for plasticity in vocal production, somewhat more for usage of calls, with the greatest plasticity arising in response to calls of others. Generally, similar results were obtained with callitrichid monkeys, the marmosets and tamarins, but with several interesting exceptions. Infant pygmy marmosets show babbling behavior with improvement in adult call structure related to the amount and diversity of babbling. Adult marmosets alter call structure in response to changes in social partners, and wild marmosets have vocal dialects and modify call structure according to how far they are from other group members, suggesting the potential to modify call structure in different social and environmental contexts, though direct learning of novel vocalizations has not been observed. Infant cotton-top tamarins do not produce adult-like calls in appropriate contexts, at least in the first few months of life, but through food sharing from adults infants learn about appropriate foods and the appropriate contexts for food vocalizations. Tamarins modify call structure and usage with changes in social status. Tamarins, unlike other monkeys tested, can learn to avoid noxious foods through observation of other group members, and can learn about novel food locations. Recent studies provide evidence of contextual imitation in marmosets. The plasticity in vocal communication and evidence of social learning in marmosets and tamarins relative to other monkeys may be related to the cooperative breeding system of marmosets and tamarins. With a high degree of behavioral coordination among group members, there is a priority on monitoring signals and behavior of others and adjusting one's own signals and behavior. This creates the context for vocal plasticity and social learning.
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Hare, B. (2001). Can competitive paradigms increase the validity of experiments on primate social cognition? Anim. Cogn., 4(3), 269–280.
Abstract: Experiments vary in their ability to distinguish between competing hypotheses. In tests on primate cognition the majority of this variation is due to an experimenter's ability to test primates in valid settings while providing the adequate amount of experimental control. While experimenters studying primate cognition can use methods of control perfected in captivity, it is still very unclear how to design and then objectively evaluate the external validity of new experimental paradigms. I recommend that more effort be allocated to specify how to create relevant test settings for primates. Primate social life is highly competitive. This means that all aspects of primates themselves, including their cognitive abilities, have likely been shaped by the need to out-compete conspecifics. Based on this hypothesis, sophisticated cognitive abilities of primates might best be demonstrated in competitive contexts. Thus, it is suggested that one possible measure of validity is whether investigators integrate a competitive component into their experimental designs. To evaluate this methodological prediction I review the literature on chimpanzee perspective-taking as a case study including several recent studies that include a competitive component in their experimental designs.
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Xitco, M., Gory, J., & Kuczaj, S. (2001). Spontaneous pointing by bottlenose dolphins (Tursiops truncatus). Anim. Cogn., 4(2), 115–123.
Abstract: Two bottlenose dolphins (Tursiops truncatus) participating in a symbolic communication project spontaneously developed behaviors that resembled pointing and gaze alternation. The dolphins' behavior demonstrated several features reminiscent of referential communicative behavior. It was triadic, involving a signaler, receiver, and referent. It was also indicative, specifying a focus of attention. The dolphins' points were distinct from the act of attending to or acting on objects. Spontaneous dolphin pointing was influenced by the presence of a potential receiver, and the distance between that receiver and the dolphin. These findings suggest that dolphins are capable of producing referential gestures.
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Brown, C. (2001). Familiarity with the test environment improves escape responses in the crimson spotted rainbowfish, Melanotaenia duboulayi. Anim. Cogn., 4(2), 109–113.
Abstract: Animals that are familiar with their environment have been reported to have greater survivorship for a number of reasons related to their knowledge of the terrain, which they recall from memory. In an initial experiment rainbowfish significantly improved their escape response towards a novel trawl apparatus over a sequence of five runs. Escape latencies were still low during a subsequent exposure 11 months after the initial exposure. While part of the improvement in escape success was certainly due to learning associated with the location of the escape route, it is likely that this was aided by habituation to the tank environment and the experimental protocol. In a follow-up experiment, fish that had been kept in the experimental tank for 3 weeks prior to testing, and had become familiar with the test tank, showed significantly lower escape latencies and escaped more often than fish that were not familiar with the test environment. It is suspected that familiarity with the testing arena decreased stress and enabled individuals to detect novel stimuli and devote more attention to them. These findings have significant implications for experimenters studying aspects of animal cognition, such as learning and memory, in laboratory situations.
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Zuberbühler, K. (2001). Predator-specific alarm calls in Campbell's monkeys, Cercopithecus campbelli. Behav. Ecol. Sociobiol., 50(5), 414–422.
Abstract: One of the most prominent behavioural features of many forest primates are the loud calls given by the adult males. Early observational studies repeatedly postulated that these calls function in intragroup spacing or intergroup avoidance. More recent field experiments with Diana monkeys (Cercopithecus diana) of Taï Forest, Ivory Coast, have clearly shown that loud male calls function as predator alarm calls because calls reliably (1) label different predator classes and (2) convey semantic information about the predator type present. Here, I test the alarm call hypothesis another primate, the Campbell's monkey (C. campbelli). Like Diana monkeys, male Campbell's monkeys produce conspicuous loud calls to crowned hawk eagles (Stephanoaetus coronatus) and leopards (Panthera pardus), two of their main predators. Playback experiments showed that monkeys responded to the predator category represented by the different playback stimuli, regardless of whether they consisted of (1) vocalisations of the actual predators (crowned hawk eagle shrieks or leopard growls), (2) alarm calls to crowned hawk eagles or leopards given by other male Campbell's monkeys or (3) alarm calls to crowned hawk eagles or leopards given by sympatric male Diana monkeys. These experiments provide further evidence that non-human primates have evolved the cognitive capacity to produce and respond to referential labels for external events.
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Tanaka, M. (2001). Discrimination and categorization of photographs of natural objects by chimpanzees (Pan troglodytes). Anim. Cogn., 4(3), 201–211.
Abstract: Two experiments assessed the ability of four adult female chimpanzees to categorize natural objects. Chimpanzees were initially trained to match different color photographs of familiar objects from four possible categories. In training, all the comparison stimuli were from the same category in one condition, and from different categories in another condition. For all subjects, training performance was consistently better for the “different category” than for the “same category” trials. Probe trials were shown after training. In probe trials, the sample and positive comparison stimuli were different items from the same category, and the foils were selected from among the three other test categories. Individual performance was above chance in probe trials, suggesting that categorization by chimpanzees may transcend perceptual resemblance. These results were later replicated with novel stimulus items from the same four categories (experiment 2). Altogether, this research demonstrates that chimpanzees grouped perceptually different exemplars within the same category, and further suggests that these animals formed conceptual representations of the categories.
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Lefebvre, L., Juretic, N., Nicolakakis, N., & Timmermans, S. (2001). Is the link between forebrain size and feeding innovations caused by confounding variables? A study of Australian and North American birds. Anim. Cogn., 4(2), 91–97.
Abstract: The short notes of ornithology journals feature new and unusual feeding behaviours, which, when systematically collated, could provide a quantitative estimate of behavioural flexibility in different bird groups. Previous studies suggest that taxonomic variation in the frequency of new behaviours (innovations) is correlated with variation in relative forebrain size. Recent work on primates shows, however, that observer bias can affect innovation frequency. We assess this possibility in birds via three estimates in North America and Australia: the number of full-length papers in academic journals, the frequency of photographs in birding magazines and a questionnaire on reporting bias given to ornithologists at a meeting. We also look at sampling effects due to single journal sources by doing a split-half analysis of our North American database (The Wilson Bulletin vs. six other journals) and adding three new Australian journals to the one we had used previously. In multiple regressions that also included species number per taxon, none of the potential biases could account for the correlation between forebrain size and innovation frequency. Species number was the best predictor of full-length paper frequency, which was the best predictor of photograph numbers. Ornithologists are not preferentially interested in innovative, large-brained taxa, suggesting that the correlation between innovations and neural substrate size is not a spurious effect of the biases examined here.
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López, J., Gómez, Y., Rodríguez, F., Broglio, C., Vargas, J., & Salas, C. (2001). Spatial learning in turtles. Anim. Cogn., 4(1), 49–59.
Abstract: Turtles (Pseudemys scripta) were trained in place, cue and control open-field procedures. The turtles trained in both the place and the cue procedures were able to learn their respective tasks with accuracy. Subsequent probe tests revealed that the turtles trained in the place task relied on the information provided by the extramaze cues to locate the goal. However, for these animals, no single cue was essential for performance, as accurate navigation to the goal was still possible when subsets of extramaze cues were eliminated. Furthermore, the turtles trained in the place task were able to navigate accurately to the goal place from new start locations. These results suggest that the turtles trained in the place task used map-like, relational strategies, by encoding the simultaneous spatial relationships between the goal and the extramaze cues in an allocentric frame of reference. In contrast, the turtles trained in the cue procedure used guidance strategies, i.e. approaching the individual intramaze cue associated to the goal as it were a beacon and largely ignoring the extramaze cues. Thus, the results of this experiment suggest that turtles are able to employ spatial strategies that closely parallel those described in mammals and birds.
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