1,720,991 research outputs found
Capuchin monkeys (Sapajus spp.) take advantage of tactile information to visually recognise different object features
No full textAlthough diurnal primate species mainly rely on sight to gather information from the environment, touch is both the first sense to develop and by far the most extensive in Primates. Systematic studies investigating the integration of information coming from the sensory systems of sight and touch are sparse in non-human primates. To date, little is known about possible enhancement effects due to the synergy of these two sensory modalities. Here, we investigated in capuchin monkeys ( n = 12) whether manipulating objects and retaining tactile memory enhanced visual discrimination learning for larger-scale (i.e. size, shape) and smaller-scale (i.e. surface) object features. A two-alternative forced choice task was used to train capuchins to visually select a rewarded stimulus between 2 wooden objects differing in size, shape or surface. Object pairs were presented in 2 conditions: the Sight condition prevented capuchins from haptically perceiving the object features; the Sight & Touch condition allowed them to gain tactile information about the object chosen by sight. Our results showed that the availability of tactile information (Sight & Touch condition) accelerated learning speeds for visual discrimination of object size, shape and surface. Overall, our data demonstrated that the acquisition of tactile information about an object's features allowed capuchins to achieve high levels of visual accuracy faster. These results suggest that information from touch influenced perceptual and/or attentional processes in visual modality and encouraged further investigation on how manual exploration affects object recognition
Integrazione multisensoriale e riconoscimento di oggetti: uccelli e primati non umani a confronto
No full textDo capuchin monkeys (Cebus apella) show analogical reasoning when using tools?. In New Frontiers in Analogy Research, Proceedings of the Second International Conference on Analogy ANALOGY-2009 (pp. 500-501). NBU Series in Cognitive Science Sofia (Bulgaria).
No full textStudent Award for the best oral presentation
No full textThe present study assessed the ability of tufted capuchin monkeys (Sapajus spp.) to solve a visual discrimination problem presented with different procedures (computerised and non-computerised). The study was done at the Unit of Cognitive Primatology and Primate Center, Institute of Cognitive Sciences and Technologies (ISTC), National Research Council of Italy (CNR) in collaboration with the Max Planck Institute for Evolutionary Anthropology of Leipzig and it had yielded results of methodological relevance in comparative visual cognition research. In particular, it has shown that the presentation of the same discrimination task by using different methodologies, even if equivalent from a functional point of view, leads to significant differences in learning speed
Integration of visuo-tactile information in tufted capuchin monkeys (Sapajus spp.) and kea (Nestor notabilis)
No full textIn this study we investigate in capuchin monkeys (Sapajus spp., N=8) and kea (Nestor notabilis, N=8), two species with acute vision and high manipulative skills, whether tactile input affects their performance in visual object discrimination. To this end, we assessed if learning speed and/or accuracy in visual modality were enhanced by tactile exploration of the object surface. Subjects were trained to select one of two PVC cylinders of the same shape and size, but with different textures in two experimental conditions. In the Sight condition the stimuli consisted of two cylinders inserted in transparent Plexiglas tubes in order to prevent the animals from haptically perceiving the texture of the objects. In the Sight & Touch condition the stimuli consisted of two cylinders that were not inserted into tubes, thus allowing the subjects to perceive their textures both visually and haptically. Our results demonstrated that both capuchins and kea (i) required fewer trials to achieve the criterion in the Sight & Touch condition than in the Sight condition, and (ii) showed comparable levels of accuracy in the two conditions at the attainment of the learning criterion. Overall, our findings suggest that, in these two phylogenetically distant species, the acquisition of tactile information during manipulative actions facilitates visual discrimination of objects
Processing of visual hierarchical stimuli by fish (Xenotoca eiseni)
No full textAbstract: Three experiments were designed to investigate visual processing of global and local dimensions of hierarchical stimuli in fish (Xenotoca eiseni). In the first experiment, fish were trained to discriminate between a circle made of circle elements and a cross made of cross elements (consistent stimuli) and tested with a, circle made of crosses and a cross made of circles (inconsistent stimuli) to asses their global/local encoding preferences. Fish were also tested for their ability to discriminate single-element shapes. The second and the third experiments manipulated the density of the local elements (Experiment 2) and the size of the global and local shapes of the stimuli (Experiment 3) to assess whether these variables could affect global or local perception of hierarchical visual patterns in fish. In all the experiments, fish showed a global preference irrespective of the density and the size of the stimuli. This preference was not because of an inability to perceive the local constituents of the stimulus, since both fish trained with consistent and fish trained with inconsistent figures showed a clear capacity to discriminate between single-element shapes. Overall, these results suggest that a global preference is not a unique trait of human beings and that differences among different vertebrate species in the global/local strategies of stimulus encoding may be because of different ecological adaptations making initial elaboration of a visual scene in a global or local way more likely
Visuo-tactile information integration in object discrimination: A comparative study on tufted capuchin monkeys (Sapajus spp.) and kea (Nestor notabilis)
No full textIn comparative visual cognition research, the influence of information acquired by non-visual senses has received little attention. Among non-visual faculties, tactile input is at least as important as visual input in supplying animals with information about the environment. Systematic studies focusing on how attaining information from different sensory modalities can affect perception are rare in non-human species. Here, we investigate, in two species with acute vision and high manipulative skills, capuchin monkeys (Sapajus spp., N=8) and kea (Nestor notabilis, N=8), whether tactile input can influence the performance in a visual discrimination task. To this end, we assessed if learning speed and/or accuracy in visual modality were facilitated by tactile exploration of the object surface. Subjects were trained to discriminate the positive stimulus of two pairs of PVC cylinders of the same shape and size, but with different textures. One pair of stimuli consisted of two cylinders that were inserted in transparent Plexiglas tubes in order to prevent the animals from haptically perceiving the texture of the chosen object (Sight Condition); the other pair of stimuli consisted of two cylinders that were not inserted into tubes, thus allowing the subject to perceive their textures both visually and haptically (Sight & Touch Condition). Our results demonstrated that both
capuchins and kea (i) required fewer trials to achieve the criterion in the Sight & Touch Condition than in the Sight Condition, and (ii) showed comparable levels of accuracy in the two conditions at the attainment of the learning criterion. Overall, our findings suggest that the opportunity to acquire tactile information during manipulative actions facilitates visual discrimination of objects
Effect of stimulus type and experimental procedure on a visual discrimination task. A study on tufted capuchin monkeys (Sapajus spp.).
No full textThe study was aimed at assessing if capuchin monkeys’ learning ability to discriminate stimuli by size varied on the basis of both stimulus types (images, foods and objects) and kind of procedures used for stimulus presentation (computerised and non-computerised). Moreover, subjects’ ability to generalise the solution of the problem across different task conditions has been evaluated
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