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Anna Wilkinson - One of the best experts on this subject based on the ideXlab platform.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
Christian Agrillo - One of the best experts on this subject based on the ideXlab platform.
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susceptibility to size visual Illusions in a non primate mammal equus caballus
Open Access Journal, 2020Co-Authors: Anansi Cappellato, Maria Elena Miletto Petrazzini, Angelo Bisazza, Marco Dadda, Christian AgrilloAbstract:The perception of different size Illusions is believed to be determined by size-scaling mechanisms that lead individuals to extrapolate inappropriate 3D information from 2D stimuli. The Muller-Lyer illusion represents one of the most investigated size Illusions. Studies on non-human primates showed a human-like perception of this illusory pattern. To date, it is not clear whether non-primate mammals experience a similar illusory effect. Here, we investigated whether horses perceive the Muller-Lyer illusion by using their spontaneous preference for the larger portion of carrot. In control trials, we presented horses with two carrot sticks of different sizes, and in test trials, carrot sticks of identical size were shown to the subjects together with arrowheads made of plastic material and arranged in a way meant to elicit the Muller-Lyer illusion in human observers. In control trials, horses significantly discriminated between the smaller and larger carrot stick. When presented with the illusion, they showed a significant preference for the carrot that humans perceive as longer. Further control trials excluded the possibility that their choices were based on the total size of the carrot stick and the arrowheads together. The susceptibility of horses to this illusion indicates that the perceptual mechanisms underlying size estimation in perissodactyla might be similar to those of primates, notwithstanding the considerable evolutionary divergence in the visual systems of these two mammalian groups.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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motion Illusions as environmental enrichment for zoo animals a preliminary investigation on lions panthera leo
Frontiers in Psychology, 2019Co-Authors: Barbara Regaiolli, Maria Elena Miletto Petrazzini, Caterina Spiezio, Angelo Rizzo, Giorgio Ottolini, Christian AgrilloAbstract:Investigating perceptual and cognitive abilities of zoo animals might help to improve their husbandry and enrich their daily life with new stimuli. Developing new environmental enrichment programs and devices is hence necessary to promote species-specific behaviours that need to be maintained in controlled environments. As far as we are aware, no study has ever tested the potential benefits of motion Illusions as visual enrichment for zoo animals. Starting from a recent study showing that domestic cats are spontaneously attracted by a well-known motion illusion, the Rotating Snake (RS) illusion, we studied whether this illusion could be used as a visual enrichment for big cats. We observed the spontaneous behaviour of three lionesses when three different visual stimuli were placed in their environment: the RS illusion and two control stimuli. The study involved two different periods: the baseline and the RS period, in which the visual stimuli were provided to the lionesses. To assess whether the lionesses were specifically attracted by the RS illusion, we collected data on the number of interactions with the stimuli, as well as on the total time spent interacting with them. To investigate the effect of the illusion on the animals’ welfare, individual and social behaviours were studied and compared between the two periods. The results showed that two lionesses out of three interacted more with the RS stimulus than with the two control stimuli. The fact that the lionesses seemed to be more inclined to interact with the RS stimulus indirectly suggests the intriguing possibility that they were attracted by the illusory motion. Moreover, behavioural changes between the two periods were reported for one of the lionesses, highlighting a reduction in self-directed behaviours and an increase in attentive behaviours, suggesting positive welfare implications. Thus, behavioural observations made before and during the presentation of the stimuli showed that our visual enrichment actually provided positive effects in lionesses. These results call for the development of future studies on the use of visual Illusions in the enrichment programs of zoo animals.
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Guppies, Poecilia reticulata, perceive a reversed Delboeuf illusion
Animal Cognition, 2019Co-Authors: Tyrone Lucon-xiccato, Christian Agrillo, Maria Santacà, Maria Elena Miletto Petrazzini, Marco DaddaAbstract:Animals are often required to estimate object sizes during several fitness-related activities, such as choosing mates, foraging, and competing for resources. Some species are susceptible to size Illusions, i.e. the misperception of the size of an object based on the surrounding context, but other species are not. This interspecific variation might be adaptive, reflecting species-specific selective pressures; according to this hypothesis, it is important to test species in which size discrimination has a notable ecological relevance. We tested susceptibility to a size illusion in the guppy, Poecilia reticulata , a fish species required to accurately estimate sizes during mate choice, foraging, and antipredator behaviours. We focussed on the Delboeuf illusion, in which an object is typically perceived to be larger when surrounded by a smaller object. In experiment 1, we trained guppies to select the larger of two circles to obtain a food reward and then tested them using stimuli arranged in a Delboeuf-like pattern. In experiment 2, we tested guppies in a spontaneous food choice task to determine whether the subjective size perception of food items is affected by the surrounding context. Jointly, our experiments indicated that guppies perceived the Delboeuf illusion, but in a reverse direction relative to humans: guppies estimated as larger the stimulus that human perceived as smaller. Our results indicated susceptibility to size Illusions also in a species required to perform accurate size discrimination and support previous evidence of variability in illusion susceptibility across vertebrates.
Maria Santacà - One of the best experts on this subject based on the ideXlab platform.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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Guppies, Poecilia reticulata, perceive a reversed Delboeuf illusion
Animal Cognition, 2019Co-Authors: Tyrone Lucon-xiccato, Christian Agrillo, Maria Santacà, Maria Elena Miletto Petrazzini, Marco DaddaAbstract:Animals are often required to estimate object sizes during several fitness-related activities, such as choosing mates, foraging, and competing for resources. Some species are susceptible to size Illusions, i.e. the misperception of the size of an object based on the surrounding context, but other species are not. This interspecific variation might be adaptive, reflecting species-specific selective pressures; according to this hypothesis, it is important to test species in which size discrimination has a notable ecological relevance. We tested susceptibility to a size illusion in the guppy, Poecilia reticulata , a fish species required to accurately estimate sizes during mate choice, foraging, and antipredator behaviours. We focussed on the Delboeuf illusion, in which an object is typically perceived to be larger when surrounded by a smaller object. In experiment 1, we trained guppies to select the larger of two circles to obtain a food reward and then tested them using stimuli arranged in a Delboeuf-like pattern. In experiment 2, we tested guppies in a spontaneous food choice task to determine whether the subjective size perception of food items is affected by the surrounding context. Jointly, our experiments indicated that guppies perceived the Delboeuf illusion, but in a reverse direction relative to humans: guppies estimated as larger the stimulus that human perceived as smaller. Our results indicated susceptibility to size Illusions also in a species required to perform accurate size discrimination and support previous evidence of variability in illusion susceptibility across vertebrates.
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Preliminary study to investigate the Delboeuf illusion in ring-tailed lemurs (Lemur catta): Methodological Challenges.
Animal Behavior and Cognition, 2017Co-Authors: Maria Santacà, Maria Elena Miletto Petrazzini, Barbara Regaiolli, Caterina Spiezio, Christian AgrilloAbstract:Visual Illusions are commonly used in animal cognition studies to compare visual perception among vertebrates. To date, researchers have focused their attention mainly on birds and mammals, especially apes and monkeys, but no study has investigated sensitivity to visual Illusions in prosimians. Here we investigated whether lemurs (Lemur catta) perceive the Delboeuf illusion, a well-known illusion that occurs when subjects misperceive the relative size of an item because of its surrounding context. In particular, we adopted the spontaneous preference paradigm used in chimpanzees and observed lemurs’ ability to select the larger amount of food. In control trials, we presented two different amounts of food on two identical plates. In test trials, we presented equal food portion sizes on two plates differing in size: If lemurs were sensitive to the illusion, they were expected to select the food portion presented on the smaller plate. In control trials, they exhibited poor performance compared to other mammals previously observed, being able to discriminate between the two quantities only in the presence of a 0.47 ratio. This result prevented us from drawing any conclusion regarding the subjects’ susceptibility to the Delboeuf illusion. In test trials with the illusory pattern, however, the subjects’ choices did not differ from chance. Our data suggest that the present paradigm is not optimal for testing the perception of the Delboeuf illusion in lemurs and highlight the importance of using different methodological approaches to assess the perceptual mechanisms underlying size discrimination among vertebrates
Maria Elena Miletto Petrazzini - One of the best experts on this subject based on the ideXlab platform.
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susceptibility to size visual Illusions in a non primate mammal equus caballus
Open Access Journal, 2020Co-Authors: Anansi Cappellato, Maria Elena Miletto Petrazzini, Angelo Bisazza, Marco Dadda, Christian AgrilloAbstract:The perception of different size Illusions is believed to be determined by size-scaling mechanisms that lead individuals to extrapolate inappropriate 3D information from 2D stimuli. The Muller-Lyer illusion represents one of the most investigated size Illusions. Studies on non-human primates showed a human-like perception of this illusory pattern. To date, it is not clear whether non-primate mammals experience a similar illusory effect. Here, we investigated whether horses perceive the Muller-Lyer illusion by using their spontaneous preference for the larger portion of carrot. In control trials, we presented horses with two carrot sticks of different sizes, and in test trials, carrot sticks of identical size were shown to the subjects together with arrowheads made of plastic material and arranged in a way meant to elicit the Muller-Lyer illusion in human observers. In control trials, horses significantly discriminated between the smaller and larger carrot stick. When presented with the illusion, they showed a significant preference for the carrot that humans perceive as longer. Further control trials excluded the possibility that their choices were based on the total size of the carrot stick and the arrowheads together. The susceptibility of horses to this illusion indicates that the perceptual mechanisms underlying size estimation in perissodactyla might be similar to those of primates, notwithstanding the considerable evolutionary divergence in the visual systems of these two mammalian groups.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors.
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can reptiles perceive visual Illusions delboeuf illusion in red footed tortoise chelonoidis carbonaria and bearded dragon pogona vitticeps
Journal of Comparative Psychology, 2019Co-Authors: Maria Santacà, Christian Agrillo, Maria Elena Miletto Petrazzini, Anna WilkinsonAbstract:Optical Illusions have been widely used to compare visual perception among vertebrates because they can reveal how the system is able to adapt to visual input. Sensitivity to visual Illusions has never been studied in reptiles. Here, we investigated whether red-footed tortoises, Chelonoidis carbonaria, and bearded dragons, Pogona vitticeps, perceive the Delboeuf illusion. This illusion involves the misperception of the size of a target circle depending upon the context in which it is presented. We adopted the same size discrimination for both species to compare their performance. Animals were presented with two different types of trials. In control trials, they received two different-sized food portions on two plates of the same size. In test trials, they received two same-sized food portions but presented on two different-sized plates. If they perceived the illusion in the same way as humans, we expected them to select the food portion presented on the smaller plate. The tortoises exhibited poor performance in the control trials, which prevented us from drawing any conclusions about their perception of the Delboeuf illusion. In contrast, the bearded dragons selected the larger amount of food in control trials. In test trials, they selected the portion presented on the smaller plate significantly more often than chance, suggesting a human-like sensitivity to the Delboeuf illusion. Our study provides the first evidence of the perception of a visual illusion in a reptile species, suggesting that rather than simply detecting visual input, they interpret sensory information captured by photoreceptors. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
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motion Illusions as environmental enrichment for zoo animals a preliminary investigation on lions panthera leo
Frontiers in Psychology, 2019Co-Authors: Barbara Regaiolli, Maria Elena Miletto Petrazzini, Caterina Spiezio, Angelo Rizzo, Giorgio Ottolini, Christian AgrilloAbstract:Investigating perceptual and cognitive abilities of zoo animals might help to improve their husbandry and enrich their daily life with new stimuli. Developing new environmental enrichment programs and devices is hence necessary to promote species-specific behaviours that need to be maintained in controlled environments. As far as we are aware, no study has ever tested the potential benefits of motion Illusions as visual enrichment for zoo animals. Starting from a recent study showing that domestic cats are spontaneously attracted by a well-known motion illusion, the Rotating Snake (RS) illusion, we studied whether this illusion could be used as a visual enrichment for big cats. We observed the spontaneous behaviour of three lionesses when three different visual stimuli were placed in their environment: the RS illusion and two control stimuli. The study involved two different periods: the baseline and the RS period, in which the visual stimuli were provided to the lionesses. To assess whether the lionesses were specifically attracted by the RS illusion, we collected data on the number of interactions with the stimuli, as well as on the total time spent interacting with them. To investigate the effect of the illusion on the animals’ welfare, individual and social behaviours were studied and compared between the two periods. The results showed that two lionesses out of three interacted more with the RS stimulus than with the two control stimuli. The fact that the lionesses seemed to be more inclined to interact with the RS stimulus indirectly suggests the intriguing possibility that they were attracted by the illusory motion. Moreover, behavioural changes between the two periods were reported for one of the lionesses, highlighting a reduction in self-directed behaviours and an increase in attentive behaviours, suggesting positive welfare implications. Thus, behavioural observations made before and during the presentation of the stimuli showed that our visual enrichment actually provided positive effects in lionesses. These results call for the development of future studies on the use of visual Illusions in the enrichment programs of zoo animals.
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Preliminary study to investigate the Delboeuf illusion in ring-tailed lemurs (Lemur catta): Methodological Challenges.
Animal Behavior and Cognition, 2017Co-Authors: Maria Santacà, Maria Elena Miletto Petrazzini, Barbara Regaiolli, Caterina Spiezio, Christian AgrilloAbstract:Visual Illusions are commonly used in animal cognition studies to compare visual perception among vertebrates. To date, researchers have focused their attention mainly on birds and mammals, especially apes and monkeys, but no study has investigated sensitivity to visual Illusions in prosimians. Here we investigated whether lemurs (Lemur catta) perceive the Delboeuf illusion, a well-known illusion that occurs when subjects misperceive the relative size of an item because of its surrounding context. In particular, we adopted the spontaneous preference paradigm used in chimpanzees and observed lemurs’ ability to select the larger amount of food. In control trials, we presented two different amounts of food on two identical plates. In test trials, we presented equal food portion sizes on two plates differing in size: If lemurs were sensitive to the illusion, they were expected to select the food portion presented on the smaller plate. In control trials, they exhibited poor performance compared to other mammals previously observed, being able to discriminate between the two quantities only in the presence of a 0.47 ratio. This result prevented us from drawing any conclusion regarding the subjects’ susceptibility to the Delboeuf illusion. In test trials with the illusory pattern, however, the subjects’ choices did not differ from chance. Our data suggest that the present paradigm is not optimal for testing the perception of the Delboeuf illusion in lemurs and highlight the importance of using different methodological approaches to assess the perceptual mechanisms underlying size discrimination among vertebrates
Mariella Pazzaglia - One of the best experts on this subject based on the ideXlab platform.
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restoring tactile awareness through the rubber hand illusion in cervical spinal cord injury
Neurorehabilitation and Neural Repair, 2013Co-Authors: Bigna Lenggenhager, Giorgio Scivoletto, Marco Molinari, Mariella PazzagliaAbstract:Background. Bodily sensations are an important component of corporeal awareness. Spinal cord injury can leave affected body parts insentient and unmoving, leading to specific disturbances in the mental representation of one’s own body and the sense of self. Objective. Here, we explored how Illusions induced by multisensory stimulation influence immediate sensory signals and tactile awareness in patients with spinal cord injuries. Methods. The rubber hand illusion paradigm was applied to 2 patients with chronic and complete spinal cord injury of the sixth cervical spine, with severe somatosensory impairments in 2 of 5 fingers. Results. Both patients experienced a strong illusion of ownership of the rubber hand during synchronous, but not asynchronous, stroking. They also, spontaneously reported basic tactile sensations in their previously numb fingers. Tactile awareness from seeing the rubber hand was enhanced by progressively increasing the stimulation duration. Conclusions. Multisensory Illusions directl...
