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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 Vallortigara, G.; Andrew, R.J. url  doi
openurl 
  Title Differential involvement of right and left hemisphere in individual recognition in the domestic chick Type Journal Article
  Year 1994 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 33 Issue 1-2 Pages 41-57  
  Keywords Right hemisphere; Left hemisphere; Domestic fowl; Lateralization; Chick  
  Abstract Right hemisphere advantage in individual recognition (as shown by differences between response to strangers and companions) is clear in the domestic chick. Chicks using the left eye (and so, thanks to the complete optic decussation, predominantly the right hemisphere) discriminate between stranger and companion. Chicks using the right eye discriminate less clearly or not at all. The ability of left eyed chicks to respond to differences between strangers and companions stimuli is associated with a more general ability to detect and respond to novelty: this difference between left and right eyed chicks also holds for stimuli which are not social partners. The right hemisphere also shows advantage in tasks with a spatial component (topographical learning; response to change in the spatial context of a stimulus) in the chick, as in humans. Similar specialisations of the two hemispheres are also revealed in tests which involve olfactory cues presented by social partners. The special properties of the left hemisphere are less well established in the chick. Evidence reviewed here suggests that it tends to respond to selected properties of a stimulus and to use them to assign it to a category; such assignment then allows an appropriate response. When exposed to an imprinting stimulus (visual or auditory) a chick begins by using right eye or ear (suggesting left hemisphere control), and then shifts to the left eye or ear (suggesting right hemisphere control), as exposure continues. The left hemisphere here is thus involved whilst behaviour is dominated by vigorous response to releasing stimuli presented by an object. Subsequent learning about the full detailed properties of the stimulus, which is crucial for individual recognition, may explain the shift to right hemisphere control after prolonged exposure to the social stimulus. There is a marked sex difference in choice tests: females tend to choose companions in tests where males choose strangers. It is possible that this difference is specifically caused by stronger motivation to sustain social contact in female chicks, for which there is extensive evidence. However, sex differences in response to change in familiar stimuli are also marked in tests which do not involve social partners. Finally, in both sexes there are two periods during development in which there age-dependent shifts in bias to use one or other hemisphere. These periods (days 3-5 and 8-11) coincide with two major changes in the social behaviour of chicks reared by a hen in a normal brood. It is argued that one function of these periods is to bring fully into play the hemisphere most appropriate to the type of response to, and learning about, social partners which is needed at particular points in development. Parallels are discussed between the involvement of lateralised processes in the recognition of social partners in chicks and humans.  
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  ISSN 0376-6357 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5341  
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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 0166-4328 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5080  
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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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  Series Volume Series Issue Edition  
  ISSN 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 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 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 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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  Series Volume Series Issue Edition  
  ISSN 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 Regolin, L.; Marconato, F.; Vallortigara, G. doi  openurl
  Title Hemispheric differences in the recognition of partly occluded objects by newly hatched domestic chicks (Gallus gallus) Type Journal Article
  Year 2004 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 7 Issue 3 Pages 162-170  
  Keywords Animals; Discrimination Learning/physiology; Dominance, Cerebral/*physiology; Female; Form Perception/*physiology; Imprinting (Psychology)/*physiology; Pattern Recognition, Visual/*physiology; Photic Stimulation; Random Allocation; Vision, Monocular/*physiology  
  Abstract Domestic chicks are capable of perceiving as a whole objects partly concealed by occluders (“amodal completion”). In previous studies chicks were imprinted on a certain configuration and at test they were required to choose between two alternative versions of it. Using the same paradigm we now investigated the presence of hemispheric differences in amodal completion by testing newborn chicks with one eye temporarily patched. Separate groups of newly hatched chicks were imprinted binocularly: (1) on a square partly occluded by a superimposed bar, (2) on a whole or (3) on an amputated version of the square. At test, in monocular conditions, each chick was presented with a free choice between a complete and an amputated square. In the crucial condition 1, chicks tested with only their left eye in use chose the complete square (like binocular chicks would do); right-eyed chicks, in contrast, tended to choose the amputated square. Similar results were obtained in another group of chicks imprinted binocularly onto a cross (either occluded or amputated in its central part) and required to choose between a complete or an amputated cross. Left-eyed and binocular chicks chose the complete cross, whereas right-eyed chicks did not choose the amputated cross significantly more often. These findings suggest that neural structures fed by the left eye (mainly located in the right hemisphere) are, in the chick, more inclined to a “global” analysis of visual scenes, whereas those fed by the right eye seem to be more inclined to a “featural” analysis of visual scenes.  
  Address Department of General Psychology, University of Padova, Via Venezia 8, 35131, Padova, Italy. lucia.regolin@unipd.it  
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  Series Volume Series Issue Edition  
  ISSN 1435-9448 ISBN Medium  
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  Notes PMID:15241654 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2519  
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Author Zucca, P.; Antonelli, F.; Vallortigara, G. doi  openurl
  Title Detour behaviour in three species of birds: quails (Coturnix sp.), herring gulls (Larus cachinnans) and canaries (Serinus canaria) Type Journal Article
  Year 2005 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 8 Issue 2 Pages 122-128  
  Keywords Animals; *Avoidance Learning; *Birds; Canaries; Charadriiformes; Coturnix; *Discrimination Learning; Orientation; *Space Perception; *Spatial Behavior; Species Specificity  
  Abstract Detour behaviour is the ability of an animal to reach a goal stimulus by moving round any interposed obstacle. It has been widely studied and has been proposed as a test of insight learning in several species of mammals, but few data are available in birds. A comparative study in three species of birds, belonging to different eco-ethological niches, allows a better understanding of the cognitive mechanism of such detour behaviour. Young quails (Coturnix sp.), herring gulls (Larus cachinnans) and canaries (Serinus canaria), 1 month old, 10-25 days old and 4-6 months old, respectively, were tested in a detour situation requiring them to abandon a clear view of a biologically interesting object (their own reflection in a mirror) in order to approach that object. Birds were placed in a closed corridor, at one end of which was a barrier through which the object was visible. Four different types of barrier were used: vertical bar, horizontal bar, grid and transparent. Two symmetrical apertures placed midline in the corridor allowed the birds to adopt routes passing around the barrier. After entering the apertures, birds could turn either right or left to re-establish social contact with the object in the absence of any local sensory cues emanating from it. Quails appeared able to solve the task, though their performance depended on the type of barrier used, which appeared to modulate their relative interest in approaching the object or in exploring the surroundings. Young herring gulls also showed excellent abilities to locate spatially the out-of-view object, except when the transparent barrier was used. Canaries, on the other hand, appeared completely unable to solve the detour task, whatever barrier was in use. It is suggested that these species differences can be accounted for in terms of adaptation to a terrestrial or aerial environment.  
  Address Laboratory of Animal Cognition and Comparative Neuroscience, Department of Psychology, University of Trieste, Via S. Anastasio 12, 34100, Trieste, Italy. zucca@units.it  
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  ISSN 1435-9448 ISBN Medium  
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  Notes PMID:15449104 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2506  
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Author Sovrano, V.A.; Bisazza, A.; Vallortigara, G. doi  openurl
  Title How fish do geometry in large and in small spaces Type Journal Article
  Year 2007 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 10 Issue 1 Pages 47-54  
  Keywords Animals; *Association Learning; Color Perception; Cues; *Discrimination Learning; *Distance Perception; *Fishes; Male; Pattern Recognition, Visual; Social Environment; *Space Perception; Visual Perception  
  Abstract It has been shown that children and non-human animals seem to integrate geometric and featural information to different extents in order to reorient themselves in environments of different spatial scales. We trained fish (redtail splitfins, Xenotoca eiseni) to reorient to find a corner in a rectangular tank with a distinctive featural cue (a blue wall). Then we tested fish after displacement of the feature on another adjacent wall. In the large enclosure, fish chose the two corners with the feature, and also tended to choose among them the one that maintained the correct arrangement of the featural cue with respect to geometric sense (i.e. left-right position). In contrast, in the small enclosure, fish chose both the two corners with the features and the corner, without any feature, that maintained the correct metric arrangement of the walls with respect to geometric sense. Possible reasons for species differences in the use of geometric and non-geometric information are discussed.  
  Address Department of General Psychology, University of Padua, Via Venezia, 8, 35131, Padova, Italy. valeriaanna.sovrano@unipd.it  
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  Series Volume Series Issue Edition  
  ISSN 1435-9448 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:16794851 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2462  
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