Westergaard, G. C., Liv, C., Rocca, A. M., Cleveland, A., & Suomi, S. J. (2004). Tufted capuchins (Cebus apella) attribute value to foods and tools during voluntary exchanges with humans. Anim. Cogn., 7(1), 19–24.
Abstract: This research examined exchange and value attribution in tufted capuchin monkeys ( Cebus apella). We presented subjects with opportunities to obtain various foods and a tool from an experimenter in exchange for the foods or tool in the subjects' possession. The times elapsed before the first chow biscuits were expelled and/or an exchange took place were recorded as the dependent measures. Laboratory chow biscuits, grapes, apples, and a metal bolt (a tool used to probe for syrup) were used as experimental stimuli. The subjects demonstrated the ability to recognize that exchanges could occur when an experimenter was present with a desirable food. Results indicate that subjects exhibited significant variation in their willingness to barter based upon the types of foods that were both in their possession and presented by the experimenter. Subjects more readily traded chow biscuits for fruit, and more readily traded apples for grapes than grapes for apples. During the exchange of tools and food, the subjects preferred the following in descending order when the probing apparatus was baited with sweet syrup: grapes, metal bolts, and chow biscuits. However when the apparatus was not baited, the values changed to the following in descending order: grapes, chow, and metal bolts. These results indicate that tufted capuchins recognize opportunities to exchange and engage in a simple barter system whereby low-valued foods are readily traded for more highly valued food. Furthermore, these capuchins demonstrate that their value for a tool changes depending upon its utility.
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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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Emery, N. J., Dally, J. M., & Clayton, N. S. (2004). Western scrub-jays ( Aphelocoma californica) use cognitive strategies to protect their caches from thieving conspecifics. Anim. Cogn., 7(1), 37–43.
Abstract: Food caching birds hide food and recover the caches when supplies are less abundant. There is, however, a risk to this strategy because the caches are susceptible to pilfering by others. Corvids use a number of different strategies to reduce possible cache theft. Scrub-jays with previous experience of pilfering other's caches cached worms in two visuospatially distinct caching trays either in private or in the presence of a conspecific. When these storers had cached in private, they subsequently observed both trays out of reach of a conspecific. When these storers had cached in the presence of a conspecific, they subsequently watched the observer pilfering from one of the trays while the other tray was placed in full view, but out of reach. The storers were then allowed to recover the remaining caches 3 h later. Jays cached more worms when they were observed during caching. At the time of recovery, they re-cached more than if they had cached in private, selectively re-caching outside of the trays in sites unbeknown to potential thieves. In addition, after a single pilfering trial, the jays switched their recovery strategy from predominantly checking their caches (i.e. returning to a cache site to see whether the food remained there) to predominantly eating them. Re-caching remained constant across the three trials. These results suggest that scrub-jays use flexible, cognitive caching and recovery strategies to aid in reducing potential future pilfering of caches by conspecifics.
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Arluke, A. (2004). The use of dogs in medical and veterinary training: understanding and approaching student uneasiness. J Appl Anim Welf Sci, 7(3), 197–204.
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Chappell J, & Kacelnik A. (2004). Selection of tool diameter by New Caledonian crows. Anim. Cogn., 7, 121.
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Gould, J. L. (2004). Thinking about thinking: how Donald R. Griffin (1915-2003) remade animal behavior. Anim. Cogn., 7(1), 1–4.
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Cheng, K. (2004). K.J. Jeffery (ed) The neurobiology of spatial behaviour. Anim. Cogn., 7(3), 199–200.
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Josep Call, Brian Hare, Malinda Carpenter, & Michael Tomasello. (2004). `Unwilling' versus `unable': chimpanzees' understanding of human intentional action. Developmental Science, 7, 488–498.
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Sullivan, R. M. (2004). Hemispheric Asymmetry in Stress Processing in Rat Prefrontal Cortex and the Role of Mesocortical Dopamine. Stress, 7(2), 131–143.
Abstract: The prefrontal cortex (PFC) is known to play an important role not only in the regulation of emotion,
but in the integration of affective states with appropriate modulation of autonomic and neuroendocrine
stress regulatory systems. The present review highlights findings in the rat which helps to elucidate the
complex nature of prefrontal involvement in emotion and stress regulation. The medial PFC is
particularly important in this regard and while dorsomedial regions appear to play a suppressive role in
such regulation, the ventromedial (particularly infralimbic) region appears to activate behavioral,
neuroendocrine and sympathetic autonomic systems in response to stressful situations. This may be
especially true of spontaneous stress-related behavior or physiological responses to relatively acute
stressors. The role of the medial PFC is somewhat more complex in conditions involving learned
adjustments to stressful situations, such as the extinction of conditioned fear responses, but it is clear
that the medial PFC is important in incorporating stressful experience for future adaptive behavior. It is
also suggested that mesocortical dopamine plays an important adaptive role in this region by preventing
excessive behavioral and physiological stress reactivity. The rat brain shows substantial hemispheric
specialization in many respects, and while the right PFC is normally dominant in the activation of
stress-related systems, the left may play a role in countering this activation through processes of
interhemispheric inhibition. This proposed basic template for the lateralization of stress regulatory
systems is suggested to be associated with efficient stress and emotional self-regulation, and also to be
shaped by both early postnatal experience and gender differences.
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Markman, E. M., & Abelev, M. (2004). Word learning in dogs? Trends. Cognit. Sci., 8(11), 479–81; discussion 481.
Abstract: In a recent paper, Kaminski, Call and Fischer report pioneering research on word-learning in a dog. In this commentary we suggest ways of distinguishing referential word use from mere association. We question whether the dog is reasoning by exclusion and, if so, compare three explanations – learned heuristics, default assumptions, and pragmatic reasoning – as they apply to children and might apply to dogs. Kaminski et al.'s work clearly raises important questions about the origins and basis of word learning and social cognition.
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