Huber, R., van Staaden, M. J., Kaufman, L. S., & Liem, K. F. (1997). Microhabitat Use, Trophic Patterns, and the Evolution of Brain Structure in African Cichlids. Brain Behav Evol, 50(3), 167–182.
Abstract: The species assemblages of cichlids in the three largest African Great Lakes are among the richest concentrations of vertebrate species on earth. The faunas are broadly similar in terms of trophic diversity, species richness, rates of endemism, and taxonomic composition, yet they are historically independent of each other. Hence, they offer a true and unique evolutionary experiment to test hypotheses concerning the mutual dependencies of ecology and brain morphology. We examined the brains of 189 species of cichlids from the three large lakes: Victoria, Tanganyika, and Malawi. A first paper demonstrated that patterns of evolutionary change in cichlid brain morphology are similar across taxonomic boundaries as well as across the three lakes [van Staaden et al., 1995 ZACS 98: 165–178]. Here we report a close relationship between the relative sizes of various brain structures and variables related to the utilization of habitat and prey. Causality is difficult to assign in this context, nonetheless, prey size and agility, turbidity levels, depth, and substrate complexity are all highly predictive of variation in brain structure. Areas associated with primary sensory functions such as vision and taste relate significantly to differences in feeding habits. Turbidity and depth are closely associated with differences in eye size, and large eyes are associated with species that pick plankton from the water column. Piscivorous taxa and others that utilize motile prey are characterized by a well developed optic tectum and a large cerebellum compared to species that prey on molluscs or plants. Structures relating to taste are well developed in species feeding on benthos over muddy or sandy substrates. The data militated against the existence of compensatory changes in brain structure. Thus enhanced development of a particular function is generally not accompanied by a parallel reduction of structures related to other modalities. Although genetic and environmental influences during ontogeny of the brain cannot be isolated, this study provides a rich source of hypotheses concerning the way the nervous system functions under various environmental conditions and how it has responded to natural selection.
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Rogers, L. J. (1997). Early Experiential Effects on Laterality: Research on Chicks has Relevance to Other Species. Laterality, 2(3-4), 199–219.
Abstract: The influence of early experience on the development of lateralisation of hemispheric function was further investigated, using the chick as a model. A range of functions are lateralised in the chick and these correlate with asymmetry in the organisation of the visual projections. Chicks using the right eye and, therefore, primarily the left hemisphere are able to switch from pecking randomly at grain and pebbles to pecking mainly at grain, whereas those using the left eye and primarily the right hemisphere continue to peck at random. Exposure to light during the last days of incubation establishes this lateralisation in males, as a consequence of the embryo being oriented in the egg so that the left eye only is occluded. Males incubated in the dark peck at random when using either the right or left eye. Irrespective of light experience, females perform the same as darkincubated males: they are not influenced by light exposure. Monocular performance of the pebble-grain task is compared to binocular performance, and the sensitive period for the influence of light is delineated. The interactive effects of sex hormone levels on the differentiation of lateralisation are discussed and also the relevance of the results to other species, including humans.
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Russell, C. L., Bard, K. A., & Adamson, L. B. (1997). Social referencing by young chimpanzees (Pan troglodytes). J. Comp. Psychol., 111(2), 185–191.
Abstract: Social referencing is the seeking of information from another individual and the use of that information to evaluate a situation. It is a well-documented ability in human infants but has not been studied experimentally in nonhuman primates. Seventeen young nursery-reared chimpanzees (14 to 41 months old) were observed in a standard social referencing paradigm in which they received happy and fear messages concerning novel objects from a familiar human caregiver. Each chimpanzee looked referentially at their caregiver, and the emotional messages that they received differentially influenced their gaze behavior and avoidance of the novel objects. It is concluded that chimpanzees can acquire information about their complex social and physical environments through social referencing and can use emotional information to alter their own behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
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Schultz, W., Dayan, P., & Montague, P. R. (1997). A Neural Substrate of Prediction and Reward. Science, 275(5306), 1593–1599.
Abstract: The capacity to predict future events permits a creature to detect, model, and manipulate the causal structure of its interactions with its environment. Behavioral experiments suggest that learning is driven by changes in the expectations about future salient events such as rewards and punishments. Physiological work has recently complemented these studies by identifying dopaminergic neurons in the primate whose fluctuating output apparently signals changes or errors in the predictions of future salient and rewarding events. Taken together, these findings can be understood through quantitative theories of adaptive optimizing control.
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Palme, R., & Moestl, E. (1997). Measurement of cortisol metabolites in faeces of sheep as a parameter of cortisol concentration in blood. J. Mammal. Biol., 62, 192–197.
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Shmidt Mech, L. D. (1997). Wolf pack size and food acquisition. Am Nat, 150.
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Kräußlich, H., & Brem, G. (1997). Tierzucht und allgemeine Landwirtschaftslehre für Tiermediziner. Stuttgart: Enke.
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