| Home | << 1 2 3 4 5 6 7 8 9 10 >> [11–20] |
|
Barrett, L., & Henzi, P. (2005). The social nature of primate cognition. Proc Biol Sci, 272(1575), 1865–1875.
Abstract: The hypothesis that the enlarged brain size of the primates was selected for by social, rather than purely ecological, factors has been strongly influential in studies of primate cognition and behaviour over the past two decades. However, the Machiavellian intelligence hypothesis, also known as the social brain hypothesis, tends to emphasize certain traits and behaviours, like exploitation and deception, at the expense of others, such as tolerance and behavioural coordination, and therefore presents only one view of how social life may shape cognition. This review outlines work from other relevant disciplines, including evolutionary economics, cognitive science and neurophysiology, to illustrate how these can be used to build a more general theoretical framework, incorporating notions of embodied and distributed cognition, in which to situate questions concerning the evolution of primate social cognition.
|
|
Joffe, T. H., & Dunbar, R. I. (1997). Visual and socio-cognitive information processing in primate brain evolution. Proc Biol Sci, 264(1386), 1303–1307.
Abstract: Social group size has been shown to correlate with neocortex size in primates. Here we use comparative analyses to show that social group size is independently correlated with the size of non-V1 neocortical areas, but not with other more proximate components of the visual system or with brain systems associated with emotional cueing (e.g. the amygdala). We argue that visual brain components serve as a social information 'input device' for socio-visual stimuli such as facial expressions, bodily gestures and visual status markers, while the non-visual neocortex serves as a 'processing device' whereby these social cues are encoded, interpreted and associated with stored information. However, the second appears to have greater overall importance because the size of the V1 visual area appears to reach an asymptotic size beyond which visual acuity and pattern recognition may not improve significantly. This is especially true of the great ape clade (including humans), that is known to use more sophisticated social cognitive strategies.
Keywords: Animals; Brain/anatomy & histology/*physiology; Cognition/physiology; *Evolution; Geniculate Bodies/anatomy & histology/physiology; Humans; Mental Processes/physiology; Neocortex/physiology; Primates/anatomy & histology/*physiology/*psychology; *Social Behavior; Visual Cortex/anatomy & histology/physiology
|
|
Zucca, P., Milos, N., & Vallortigara, G. (2007). Piagetian object permanence and its development in Eurasian jays (Garrulus glandarius). Anim. Cogn., 10(2), 243–258.
Abstract: Object permanence in Eurasian jays (Garrulus glandarius) was investigated using a complete version of the Uzgiris and Hunt scale 1. Nine hand-raised jays were studied, divided into two groups according to their different developmental stages (experiment 1, older jays: 2-3 months old, n = 4; experiment 2, younger jays: 15 days old, n = 5). In the first experiment, we investigated whether older jays could achieve piagetian stage 6 of object permanence. Tasks were administered in a fixed sequence (1-15) according to the protocols used in other avian species. The aim of the second experiment was to check whether testing very young jays before their development of “neophobia” could influence the achievement times of piagetian stages. Furthermore, in this experiment tasks were administered randomly to investigate whether the jays' achievement of stage 6 follows a fixed sequence related to the development of specific cognitive abilities. All jays tested in experiments 1 and 2 fully achieved piagetian stage 6 and no “A not B” errors were observed. Performance on visible displacement tasks was better than performance on invisible ones. The results of experiment 2 show that “neophobia” affected the response of jays in terms of achievement times; the older jays in experiment 1 took longer to pass all the tasks when compared with the younger, less neophobic, jays in experiment 2. With regard to the achieving order, jays followed a fixed sequence of acquisition in experiment 2, even if tasks were administered randomly, with the exception of one subject. The results of these experiments support the idea that piagetian stages of cognitive development exist in avian species and that they progress through relatively fixed sequences.
Keywords: Animals; *Behavior, Animal; Birds/*physiology; *Cognition; *Cues
|
|
Tanaka, M. (2007). Recognition of pictorial representations by chimpanzees (Pan troglodytes). Anim. Cogn., 10(2), 169–179.
Abstract: In this study, I investigated chimpanzees' ability to recognize pictorial representations. Four adults and three juvenile chimpanzees were trained to choose images of photographs of flowers among 12 items belonging to four categories on a touch-sensitive monitor. As a generalization test, the following five types of images were presented: (1) novel photographs, (2) colored sketches (more realistic), (3) a colored clip art (cartoon-like images), (4) black-and-white line drawings, and (5) Kanji characters (as the control images). One adult and all three juvenile chimpanzees were able to choose any style of the nonphotographic images of flowers significantly above the chance level, whereas none could choose the correct Kanji characters corresponding to a flower significantly above the chance level. The other three adult chimpanzees' performance level did not exceed the chance level in terms of choosing nonphotographic images although they showed good transfer skills to novel photographs. The results revealed that not all chimpanzees could recognize pictures used by humans without training. The results also suggest “critical period” in acquisition of skill in recognizing pictures in chimpanzees. Only one adult chimpanzee, who had acquired skill in recognizing visual symbols, also recognized pictures aside from the juvenile chimpanzees. Her learning history might have aided her in acquiring this skill. The results of this study suggest a relationship between pictorial competence and symbolic one.
|
|
Tebbich, S., Seed, A. M., Emery, N. J., & Clayton, N. S. (2007). Non-tool-using rooks, Corvus frugilegus, solve the trap-tube problem. Anim. Cogn., 10(2), 225–231.
Abstract: The trap-tube problem is used to assess whether an individual is able to foresee the outcome of its actions. To solve the task, an animal must use a tool to push a piece of food out of a tube, which has a trap along its length. An animal may learn to avoid the trap through a rule based on associative processes, e.g. using the distance of trap or food as a cue, or by understanding relations between cause and effect. This task has been used to test physical cognition in a number of tool-using species, but never a non-tool-user. We developed an experimental design that enabled us to test non-tool-using rooks, Corvus frugilegus. Our modification of the task removed the cognitive requirements of active tool use but still allowed us to test whether rooks can solve the trap-tube problem, and if so how. Additionally, we developed two new control tasks to determine whether rooks were able to transfer knowledge to similar, but novel problems, thus revealing more about the mechanisms involved in solving the task. We found that three out of seven rooks solved the modified trap-tube problem task, showing that the ability to solve the trap-tube problem is not restricted to tool-using animals. We found no evidence that the birds solved the task using an understanding of its causal properties, given that none of the birds passed the novel transfer tasks.
|
|
Chiandetti, C., Regolin, L., Sovrano, V. A., & Vallortigara, G. (2007). Spatial reorientation: the effects of space size on the encoding of landmark and geometry information. Anim. Cogn., 10(2), 159–168.
Abstract: The effects of the size of the environment on animals' spatial reorientation was investigated. Domestic chicks were trained to find food in a corner of either a small or a large rectangular enclosure. A distinctive panel was located at each of the four corners of the enclosures. After removal of the panels, chicks tested in the small enclosure showed better retention of geometrical information than chicks tested in the large enclosure. In contrast, after changing the enclosure from a rectangular-shaped to a square-shaped one, chicks tested in the large enclosure showed better retention of landmark (panels) information than chicks tested in the small enclosure. No differences in the encoding of the overall arrangement of landmarks were apparent when chicks were tested for generalisation in an enclosure differing from that of training in size together with a transformation (affine transformation) that altered the geometric relations between the target and the shape of the environment. These findings suggest that primacy of geometric or landmark information in reorientation tasks depends on the size of the experimental space, likely reflecting a preferential use of the most reliable source of information available during visual exploration of the environment.
|
|
Watanabe, S., & Troje, N. F. (2006). Towards a “virtual pigeon”: a new technique for investigating avian social perception. Anim. Cogn., 9(4), 271–279.
Abstract: The purpose of the present study is to examine the applicability of a computer-generated, virtual animal to study animal cognition. Pigeons were trained to discriminate between movies of a real pigeon and a rat. Then, they were tested with movies of the computer-generated (CG) pigeon. Subjects showed generalization to the CG pigeon, however, they also responded to modified versions in which the CG pigeon was showing impossible movement, namely hopping and walking without its head bobbing. Hence, the pigeons did not attend to these particular details of the display. When they were trained to discriminate between the normal and the modified version of the CG pigeon, they were able to learn the discrimination. The results of an additional partial occlusion test suggest that the subjects used head movement as a cue for the usual vs. unusual CG pigeon discrimination.
Keywords: Animals; Behavioral Research/instrumentation/methods; Columbidae/*physiology; Computer Graphics; *Computer Simulation; Discrimination Learning/*physiology; Generalization (Psychology)/*physiology; Pattern Recognition, Visual/*physiology; Perceptual Masking/physiology; Rats; Recognition (Psychology)/physiology; *Social Behavior; User-Computer Interface
|
|
Call, J. (2006). Inferences by exclusion in the great apes: the effect of age and species. Anim. Cogn., 9(4), 393–403.
Abstract: This study investigated the ability of chimpanzees, gorillas, orangutans, and bonobos to make inferences by exclusion using the procedure pioneered by Premack and Premack (Cognition 50:347-362, 1994) with chimpanzees. Thirty apes were presented with two different food items (banana vs. grape) on a platform and covered with identical containers. One of the items was removed from the container and placed between the two containers so that subjects could see it. After discarding this item, subjects could select between the two containers. In Experiment 1, apes preferentially selected the container that held the item that the experimenter had not discarded, especially if subjects saw the experimenter remove the item from the container (but without seeing the container empty). Experiment 3 in which the food was removed from one of the containers behind a barrier confirmed these results. In contrast, subjects performed at chance levels when a stimulus (colored plastic chip: Exp. 1; food item: Exp. 2 and Exp. 3) designated the item that had been removed. These results indicated that apes made inferences, not just learned to use a discriminative cue to avoid the empty container. Apes perceived and treated the item discarded by the experimenter as if it were the very one that had been hidden under the container. Results suggested a positive relationship between age and inferential ability independent of memory ability but no species differences.
|
|
Clara, E., Regolin, L., Vallortigara, G., & Rogers, L. (2007). Perception of the stereokinetic illusion by the common marmoset (Callithrix jacchus). Anim. Cogn., 10(2), 135–140.
Abstract: Stereokinetic illusions have never been investigated in non-human primates, nor in other mammalian species. These illusions consist in the perception of a 3D solid object when certain 2D stimuli are rotated slowly in the plane perpendicular to the line of sight. The ability to perceive the stereokinetic illusion was investigated in the common marmoset (Callithrix jacchus). Four adult marmosets were trained to discriminate between a solid cylinder and a solid cone for food reward. Once learning criterion was reached, the marmosets were tested in sets of eight probe trials in which the two solid objects used at training were replaced by two rotating 2D stimuli. Only one of these stimuli produced, at least to the human observer, the stereokinetic illusion corresponding to the solid object previously reinforced. At test, the general behaviour and the total time spent by the marmosets observing each stimulus were recorded. The subjects stayed longer near the stimulus producing the stereokinetic illusion corresponding to the solid object reinforced at training than they did near the illusion corresponding to the previously non-rewarded stimulus. Hence, the common marmosets behaved as if they could perceive stereokinetic illusions.
|
|
Benard, J., Stach, S., & Giurfa, M. (2006). Categorization of visual stimuli in the honeybee Apis mellifera. Anim. Cogn., 9(4), 257–270.
Abstract: Categorization refers to the classification of perceptual input into defined functional groups. We present and discuss evidence suggesting that stimulus categorization can also be found in an invertebrate, the honeybee Apis mellifera, thus underlining the generality across species of this cognitive process. Honeybees show positive transfer of appropriate responding from a trained to a novel set of visual stimuli. Such a transfer was demonstrated for specific isolated features such as symmetry or orientation, but also for assemblies (layouts) of features. Although transfer from training to novel stimuli can be achieved by stimulus generalization of the training stimuli, most of these transfer tests involved clearly distinguishable stimuli for which generalization would be reduced. Though in most cases specific experimental controls such as stimulus balance and discriminability are still required, it seems appropriate to characterize the performance of honeybees as reflecting categorization. Further experiments should address the issue of which categorization theory accounts better for the visual performances of honeybees.
|