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Author Vallortigara, G.; Rogers, L.J.
Title Survival with an asymmetrical brain: advantages and disadvantages of cerebral lateralization Type Journal Article
Year 2005 Publication The Behavioral and Brain Sciences Abbreviated Journal Behav Brain Sci
Volume 28 Issue 4 Pages 575-89; discussion 589-633
Keywords Animals; Attention/*physiology; Behavior/*physiology; Behavior, Animal/*physiology; Dominance, Cerebral/*physiology; *Evolution; Humans; Models, Biological; Visual Perception/physiology
Abstract Recent evidence in natural and semi-natural settings has revealed a variety of left-right perceptual asymmetries among vertebrates. These include preferential use of the left or right visual hemifield during activities such as searching for food, agonistic responses, or escape from predators in animals as different as fish, amphibians, reptiles, birds, and mammals. There are obvious disadvantages in showing such directional asymmetries because relevant stimuli may be located to the animal's left or right at random; there is no a priori association between the meaning of a stimulus (e.g., its being a predator or a food item) and its being located to the animal's left or right. Moreover, other organisms (e.g., predators) could exploit the predictability of behavior that arises from population-level lateral biases. It might be argued that lateralization of function enhances cognitive capacity and efficiency of the brain, thus counteracting the ecological disadvantages of lateral biases in behavior. However, such an increase in brain efficiency could be obtained by each individual being lateralized without any need to align the direction of the asymmetry in the majority of the individuals of the population. Here we argue that the alignment of the direction of behavioral asymmetries at the population level arises as an “evolutionarily stable strategy” under “social” pressures occurring when individually asymmetrical organisms must coordinate their behavior with the behavior of other asymmetrical organisms of the same or different species.
Address Department of Psychology and B.R.A.I.N. Centre for Neuroscience, University of Trieste, 34123 Trieste, Italy. vallorti@univ.trieste.it
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0140-525X ISBN Medium (up)
Area Expedition Conference
Notes PMID:16209828 Approved no
Call Number Equine Behaviour @ team @ Serial 4622
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Author Reboreda, J.C.; Clayton, N.S.; Kacelnik, A.
Title Species and sex differences in hippocampus size in parasitic and non-parasitic cowbirds Type Journal Article
Year 1996 Publication Neuroreport Abbreviated Journal Neuroreport
Volume 7 Issue 2 Pages 505-508
Keywords Animals; Birds/*physiology; Female; Hippocampus/*anatomy & histology; Male; Nesting Behavior/*physiology; Sex Characteristics; Species Specificity; Telencephalon/anatomy & histology
Abstract To test the hypothesis that selection for spatial abilities which require birds to locate and to return accurately to host nests has produced an enlarged hippocampus in brood parasites, three species of cowbird were compared. In shiny cowbirds, females search for host nests without the assistance of the male; in screaming cowbirds, males and females inspect hosts' nests together; in bay-winged cowbirds, neither sex searches because this species is not a brood parasite. As predicted, the two parasitic species had a relatively larger hippocampus than the non-parasitic species. There were no sex differences in relative hippocampus size in screaming or bay-winged cowbirds, but female shiny cowbirds had a larger hippocampus than the male.
Address Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0959-4965 ISBN Medium (up)
Area Expedition Conference
Notes PMID:8730816 Approved no
Call Number Equine Behaviour @ team @ Serial 4798
Permanent link to this record