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Author Regolin, L.; Tommasi, L.; Vallortigara, G. doi  openurl
  Title Visual perception of biological motion in newly hatched chicks as revealed by an imprinting procedure Type Journal Article
  Year 2000 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 3 Issue 1 Pages 53-60  
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  Abstract Day-old chicks were exposed to point-light animation sequences depicting either a walking hen or a rotating cylinder. On a subsequent free-choice test (experiment 1) the chicks approached the novel stimulus, irrespective of this being the hen or the cylinder. In order to obtain equivalent local motion vectors, in experiments 2 and 3 newly hatched chicks were exposed either to a point-light animation sequence depicting a walking hen, or to a positionally scrambled walking hen (i.e. an animation in which exactly the same set of dots in motion as that employed for the walking hen was presented, but with spatially randomized starting positions). Chicks tested on day 1 (experiment 2) or on day 2 (i.e. after a period in the dark following exposure on day 1 (experiment 3)) proved able to discriminate the two animation sequences: males preferentially approached the novel stimulus, females the familiar one. These results indicate that discrimination was not based on local motion vectors, but rather on the temporally integrated motion sequence.  
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  Call Number Equine Behaviour @ team @ Serial 3314  
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Author Vallortigara, G.; Regolin, L.; Rigoni, M.; Zanforlin, M. doi  openurl
  Title Delayed search for a concealed imprinted object in the domestic chick Type Journal Article
  Year 1998 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 1 Issue 1 Pages 17-24  
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  Abstract Five-day-old chicks were accustomed to follow an imprinted object (a small red ball with which they had been reared) that was moving slowly in a large arena, until it disappeared behind an opaque screen. In experiments, each chick was initially confined in a transparent cage, from where it could see and track the ball while it moved towards, and then beyond, one of two screens. The screens could be either identical or differ in colour and pattern. Either immediately after the disappearance of the ball, or with a certain delay, the chick was released and allowed to search for its imprinted object behind either screen. The results showed that chicks took into account the directional cue provided by the ball movement and its concealment, up to a delay period of about 180 s, independently of the perceptual characteristics of the two screens. If an opaque partition was positioned in front of the transparent cage immediately after the ball had disappeared, so that, throughout the delay, neither the goal-object nor the two screens were visible, chicks were still capable of remembering and choosing the correct screen, though over a much shorter period of about 60 s. The results suggest that, at least in this precocial bird species, very young chicks can maintain some form of representation of the location where a social partner was last seen, and are also capable of continuously updating this representation so as to take into account successive displacements of the goal-object.  
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  Call Number Equine Behaviour @ team @ Serial 3347  
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Author Sovrano, V.A.; Rainoldi, C.; Bisazza, A.; Vallortigara, G. url  openurl
  Title Roots of brain specializations: preferential left-eye use during mirror-image inspection in six species of teleost fish Type Journal Article
  Year 1999 Publication Behavioural Brain Research Abbreviated Journal Behav. Brain. Res.  
  Volume 106 Issue 1-2 Pages 175-180  
  Keywords Predator fixation; Fish; Left-eye preference  
  Abstract It has recently been reported that predator inspection is more likely to occur when a companion (i.e. the mirror image of the test animal) is visible on the left rather than on the right side of mosquitofish Gambusia holbrooki. This very unexpected outcome could be consistent with the hypothesis of a preferential use of the right eye during sustained fixation of a predator as well as of a preferential use of the left eye during fixation of conspecifics. We measured the time spent in monocular viewing during inspection of their own mirror images in females of six species of fish, belonging to different families--G. holbrooki, Xenotoca eiseni, Phoxinus phoxinus, Pterophyllum scalare, Xenopoecilus sarasinorum, and Trichogaster trichopterus. Results revealed a consistent left-eye preference during sustained fixation in all of the five species. Males of G. holbrooki, which do not normally show any social behaviour, did not exhibit any eye preferences during mirror-image inspection. We found, however, that they could be induced to manifest a left-eye preference, likewise females, if tested soon after capture, when some affiliative tendencies can be observed. These findings add to current evidence in a variety of vertebrate species for preferential involvement of structures located in the right side of the brain in response to the viewing of conspecifics.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 614  
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Author Ghirlanda, S.; Vallortigara, G. url  doi
openurl 
  Title The evolution of brain lateralization: a game-theoretical analysis of population structure Type Journal Article
  Year 2004 Publication Proceedings of the Royal Society of London. Series B: Biological Sciences Abbreviated Journal  
  Volume 271 Issue 1541 Pages 853-857  
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  Abstract In recent years, it has become apparent that behavioural and brain lateralization at the population level is the rule rather than the exception among vertebrates. The study of these phenomena has so far been the province of neurology and neuropsychology. Here, we show how such research can be integrated with evolutionary biology to understand lateralization more fully. In particular, we address the fact that, within a species, left– and right–type individuals often occur in proportions different from one–half (e.g. hand use in humans). The traditional explanations offered for lateralization of brain function (that it may avoid unnecessary duplication of neural circuitry and reduce interference between functions) cannot account for this fact, because increased individual efficiency is unrelated to the alignment of lateralization at the population level. A further puzzle is that such an alignment may even be disadvantageous, as it makes individual behaviour more predictable to other organisms. Here, we show that alignment of the direction of behavioural asymmetries in a population can arise as an evolutionarily stable strategy when individual asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Brain and behavioural lateralization, as we know it in humans and other vertebrates, may have evolved under basically ‘social’ selection pressures.  
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  Call Number Equine Behaviour @ team @ Serial 5345  
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Author Ghirlanda, S.; Frasnelli, E.; Vallortigara, G. url  doi
openurl 
  Title Intraspecific competition and coordination in the evolution of lateralization Type Journal Article
  Year 2009 Publication Philosophical Transactions of the Royal Society B: Biological Sciences Abbreviated Journal Phil. Trans. Biol. Sci.  
  Volume 364 Issue 1519 Pages 861-866  
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  Abstract Recent studies have revealed a variety of left–right asymmetries among vertebrates and invertebrates. In many species, left- and right-lateralized individuals coexist, but in unequal numbers (‘population-level’ lateralization). It has been argued that brain lateralization increases individual efficiency (e.g. avoiding unnecessary duplication of neural circuitry and reducing interference between functions), thus counteracting the ecological disadvantages of lateral biases in behaviour (making individual behaviour more predictable to other organisms). However, individual efficiency does not require a definite proportion of left- and right-lateralized individuals. Thus, such arguments do not explain population-level lateralization. We have previously shown that, in the context of prey–predator interactions, population-level lateralization can arise as an evolutionarily stable strategy when individually asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Here, we extend our model showing that populations consisting of left- and right-lateralized individuals in unequal numbers can be evolutionarily stable, based solely on strategic factors arising from the balance between antagonistic (competitive) and synergistic (cooperative) interactions.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5346  
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Author Siniscalchi, M.; Sasso, R.; Pepe, A.M.; Dimatteo, S.; Vallortigara, G.; Quaranta, A. url  doi
openurl 
  Title Sniffing with the right nostril: lateralization of response to odour stimuli by dogs Type Journal Article
  Year Publication Animal Behaviour Abbreviated Journal Anim. Behav.  
  Volume In Press, Corrected Proof Issue Pages  
  Keywords animal welfare; Canis familiaris; dog; emotion; laterality olfaction; physiology  
  Abstract Lateralization in dogs, Canis familiaris, has been reported for paw usage and response to visual and acoustic stimuli. Surprisingly, however, no investigation of possible lateralization for the most relevant sensory domain of dogs, namely olfaction, has been carried out. Here we investigated left and right nostril use in dogs freely sniffing different emotive stimuli in unrestrained conditions. When sniffing novel nonaversive stimuli (food, lemon, vaginal secretion and cotton swab odours), dogs showed initial preferential use of the right nostril and then a shift towards use of the left nostril with repeated stimulus presentation. When sniffing arousal stimuli such as adrenaline and veterinary sweat odorants, dogs showed a consistent right nostril bias all over the series of stimulus presentations. Results suggest initial involvement of the right hemisphere in processing of novel stimuli followed by the left hemisphere taking charge of control of routine behaviour. Sustained right nostril response to arousal stimuli appears to be consistent with the idea that the sympathetic hypothalamic-pituitary-adrenal axis is mainly under the control of the right hemisphere. The implications of these findings for animal welfare are discussed.  
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  ISSN (up) 0003-3472 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5394  
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Author Ventolini, N.; Ferrero, E.A.; Sponza, S.; Della Chiesa, A.; Zucca, P.; Vallortigara, G. url  doi
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  Title Laterality in the wild: preferential hemifield use during predatory and sexual behaviour in the black-winged stilt Type Journal Article
  Year 2005 Publication Animal Behaviour Abbreviated Journal Anim. Behav.  
  Volume 69 Issue 5 Pages 1077-1084  
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  Abstract We recorded preferential use of the left and right monocular visual field in black-winged stilts, Himantopus himantopus, during predatory pecking and during courtship and mating behaviour in a naturalistic setting. The stilts had a population-level preference for using their right monocular visual field before predatory pecking; pecks that followed right-hemifield detection were more likely to be successful than pecks that followed left-hemifield detection, as evinced by the occurrence of swallowing and shaking head movements after pecking. In contrast, shaking behaviour, a component of courtship displays, and copulatory attempts by males were more likely to occur when females were seen with the left monocular visual field. Asymmetric hemifield use observed in natural conditions raises interesting issues as to the costs and benefits of population-level behavioural lateralization in wild animals.  
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  ISSN (up) 0003-3472 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5589  
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Author Tommasi, L.; Vallortigara, G. openurl 
  Title Searching for the center: spatial cognition in the domestic chick (Gallus gallus) Type Journal Article
  Year 2000 Publication Journal of Experimental Psychology. Animal Behavior Processes Abbreviated Journal J Exp Psychol Anim Behav Process  
  Volume 26 Issue 4 Pages 477-486  
  Keywords Animals; Behavior, Animal/physiology; Chickens; Cognition/*physiology; Learning/physiology; Male; Space Perception/*physiology; Spatial Behavior/*physiology  
  Abstract Chicks learned to find food hidden under sawdust by ground-scratching in the central position of the floor of a closed arena. When tested inan arena of identical shape but a larger area, chicks searched at 2 different locations, one corresponding to the correct distance (i.e., center) in the smaller (training) arena and the other to the actual center of the test arena. When tested in an arena of the same shape but a smaller area, chicks searched in the center of it. These results suggest that chicks are able to encode information on the absolute and relative distance of the food from the walls of the arena. After training in the presence of a landmark located at the center of the arena, animals searched at the center even after the removal of the landmark. Marked changes in the height of the walls of the arena produced some displacement in searching behavior, suggesting that chicks used the angular size of the walls to estimate distances.  
  Address Department of General Psychology, University of Padua, Italy  
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  ISSN (up) 0097-7403 ISBN Medium  
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  Notes PMID:11056887 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2774  
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Author Vallortigara, G.; Rogers, L.J. url  doi
openurl 
  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  
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  ISSN (up) 0140-525X ISBN Medium  
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  Notes PMID:16209828 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4622  
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Author Siniscalchi, M.; Sasso, R.; Pepe, A.M.; Vallortigara, G.; Quaranta, A. url  doi
openurl 
  Title Dogs turn left to emotional stimuli Type Journal Article
  Year 2010 Publication Behavioural Brain Research Abbreviated Journal Behav. Brain. Res.  
  Volume 208 Issue 2 Pages 516-521  
  Keywords Dog; Laterality; Vision; Behaviour; Physiology; Cognition; Emotion; Animal welfare  
  Abstract During feeding behaviour, dogs were suddenly presented with 2D stimuli depicting the silhouette of a dog, a cat or a snake simultaneously into the left and right visual hemifields. A bias to turn the head towards the left rather than the right side was observed with the cat and snake stimulus but not with the dog stimulus. Latencies to react following stimulus presentation were lower for left than for right head turning, whereas times needed to resume feeding behaviour were higher after left rather than after right head turning. When stimuli were presented only to the left or right visual hemifields, dogs proved to be more responsive to left side presentation, irrespective of the type of stimulus. However, cat and snake stimuli produced shorter latencies to react and longer times to resume feeding following left rather than right monocular visual hemifield presentation. Results demonstrate striking lateralization in dogs, with the right side of the brain more responsive to threatening and alarming stimuli. Possible implications for animal welfare are discussed.  
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  ISSN (up) 0166-4328 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5080  
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