|
|
Hanggi, E. B., Ingersoll, J. F., & Waggoner, T. L. (2007). Color vision in horses (Equus caballus): deficiencies identified using a pseudoisochromatic plate test. J. Comp. Psychol., 121(1), 65–72.
Abstract: In the past, equine color vision was tested with stimuli composed either of painted cards or photographic slides or through physiological testing using electroretinogram flicker photometry. Some studies produced similar results, but others did not, demonstrating that there was not yet a definitive answer regarding color vision in horses (Equus caballus). In this study, a pseudoisochromatic plate test--which is highly effective in testing color vision both in small children and in adult humans--was used for the first time on a nonhuman animal. Stimuli consisted of different colored dotted circles set against backgrounds of varying dots. The coloration of the circles corresponded to the visual capabilities of different types of color deficiencies (anomalous trichromacy and dichromacy). Four horses were tested on a 2-choice discrimination task. All horses successfully reached criterion for gray circles and demonstration circles. None of the horses were able to discriminate the protan-deutan plate or the individual protan or deutan plates. However, all were able to discriminate the tritan plate. The results suggest that horses are dichromats with color vision capabilities similar to those of humans with red-green color deficiencies.
|
|
|
|
Langbein, J., Nurnberg, G., Puppe, B., & Manteuffel, G. (2006). Self-Controlled Visual Discrimination Learning of Group-Housed Dwarf Goats (Capra hircus): Behavioral Strategies and Effects of Relocation on Learning and Memory. J. Comp. Psychol., 120(1), 58–66.
Abstract: In most studies on animal learning, individual animals are tested separately in a specific learning environment and with a limited number of trials per day. An alternative approach is to test animals in a familiar environment in their social group. In this study, the authors--applying a fully automated learning device--investigated voluntary, self-controlled visual shape discrimination learning of group-housed dwarf goats (Capra hircus). The majority of the tested goats showed successful shape discrimination, which indicates the adaptive value of an effective learning strategy. However, in each group, a few individual goats developed behavioral strategies different from shape discrimination to get reward. Relocation impairs memory retrieval (probably by attention shifting) only temporarily for previously learnt shapes. The results demonstrate the usefulness of a self-controlled learning paradigm to assess learning abilities of social species in their normal social settings. This may be especially relevant for captive animals to improve their welfare.
|
|
|
|
Russon, A. E., & Galdikas, B. M. F. (1995). Constraints on great apes' imitation: Model and action selectivity in rehabilitant orangutan (Pongo pygmaeus) imitation. J. Comp. Psychol., 109(1), 5–17.
Abstract: We discuss selectivity in great ape imitation, on the basis of an observational study of spontaneous imitation in free-ranging rehabilitant orangutans (Pongo pygmaeus). Research on great ape imitation has neglected selectivity, although comparative evidence suggests it may be important. We observed orangutans in central Indonesian Borneo and assessed patterns in the models and actions they spontaneously imitated. The patterns we found resembled those reported in humans. Orangutans preferred models with whom they had positive affective relationships (e.g., important caregiver or older sibling) and actions that reflected their current competence, were receptively familiar, and were relevant to tasks that faced them. Both developmental and individual variability were found. We discuss the probable functions of imitation for great apes and the role of selectivity in directing it. We also make suggestions for more effective elicitation of imitation. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
|
|
|
|
Custance, D., Whiten, A., & Fredman, T. (1999). Social learning of an artificial fruit task in capuchin monkeys (Cebus apella). J. Comp. Psychol., 113(1), 13–23.
Abstract: Social learning in 11 human-raised capuchin monkeys (Cebus apella) was investigated using an artificial fruit that was designed as an analogue of natural foraging problems faced by primates. Each subject observed a human model open each of 3 principal components on the fruit in 1 of 2 alternative ways (“morphs”). The capuchin monkeys reproduced, to differing extents, the alternative techniques used for opening 1 component of the task (poking vs. pulling while twisting out a pair of smooth plastic bolts) but not the other 2. From the subjects' actions on the bolt latch, independent coders could recognize which morph they had witnessed, and they observed a degree of matching to the demonstrator's act consistent with simple imitation or object movement reenactment (A learns from watching B how an object, or parts of an object, move). Thus, these capuchins were capable of more complex social learning than has been recently ascribed to monkeys. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
|
|
|
|
Hare, B., & Tomasello, M. (1999). Domestic Dogs (Canis familiaris) Use Human and Conspecific Social Cues to Locate Hidden Food. J. Comp. Psychol., 113(2), 173–177.
Abstract: Ten domestic dogs (Canis familiaris) of different breeds and ages were exposed to 2 different social cues indicating the location of hidden food, each provided by both a human informant and a conspecific informant (for a total of 4 different social cues). For the local enhancement cue, the informant approached the location where food was hidden and then stayed beside it. For the gaze and point cue, the informant stood equidistant between 2 hiding locations and bodily oriented and gazed toward the 1 in which food was hidden (the human informant also pointed). Eight of the 10 subjects, including the one 6-month-old juvenile, were above chance with 2 or more cues. Results are discussed in terms of the phylogenetic and ontogenetic processes by means of which dogs come to use social cues to locate food.
|
|
|
|
Miklosi, A., Pongracz, P., Lakatos, G., Topal, J., & Csanyi, V. (2005). A Comparative Study of the Use of Visual Communicative Signals in Interactions Between Dogs (Canis familiaris) and Humans and Cats (Felis catus) and Humans. J. Comp. Psychol., 119(2), 179–186.
Abstract: Dogs' (Canis familiaris) and cats' (Felis catus) interspecific communicative behavior toward humans was investigated. In Experiment 1, the ability of dogs and cats to use human pointing gestures in an object-choice task was compared using 4 types of pointing cues differing in distance between the signaled object and the end of the fingertip and in visibility duration of the given signal. Using these gestures, both dogs and cats were able to find the hidden food; there was no significant difference in their performance. In Experiment 2, the hidden food was made inaccessible to the subjects to determine whether they could indicate the place of the hidden food to a naive owner. Cats lacked some components of attention-getting behavior compared with dogs. The results suggest that individual familiarization with pointing gestures ensures high-level performance in the presence of such gestures; however, species-specific differences could cause differences in signaling toward the human.
|
|
|
|
Fragaszy, D. M., & Visalberghi E. (1989). Social influences on the acquisition of tool-using behaviors in tufted capuchin monkeys (Cebus apella). J. Comp. Psychol., 103(2), 159–170.
Abstract: To identify behaviors related to acquisition of tool-use in tufted capuchins (Cebus apella), we presented two tool-using tasks to two groups, extending findings by Westergaard and Fragaszy (1987) and Visalberghi (in press). Five Ss learned to use the tools in each task. The primary predictor of success was level of interest in the task. Observation of others at the apparatus did not facilitate exploratory behaviors or contact with the tools in the observers. Most animals performed exploratory behaviors more often when they were at the apparatus alone than when with another, whether or not the other was using a tool. Observers were quick to learn the relationship between another's activities and the appearance of food. We conclude that capuchins do not readily learn about instrumental relations by observation of others or imitate other's acts. Imitation probably plays no role in the spread of novel instrumental behaviors among monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
|
|
|
|
Call J. (2004). Inferences about the location of food in the great apes (Pan paniscus, Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus). J. Comp. Psychol., 118(2), 232.
Abstract: Bonobos (Pan paniscus; n = 4), chimpanzees (Pan troglodytes; n = 12), gorillas (Gorilla gorilla; n = 8), and orangutans (Pongo pygmaeus; n = 6) were presented with 2 cups (1 baited) and given visual or auditory information about their contents. Visual information consisted of letting subjects look inside the cups. Auditory information consisted of shaking the cup so that the baited cup produced a rattling sound. Subjects correctly selected the baited cup both when they saw or heard the food. Nine individuals were above chance in both visual and auditory conditions. More important, subjects as a group selected the baited cup when only the empty cup was either shown or shaken, which means that subjects chose correctly without having seen or heard the food (i.e., inference by exclusion). Control tests showed that subjects were not more attracted to noisy cups, avoided shaken noiseless cups, or learned to use auditory information as a cue during the study. It is concluded that subjects understood that the food caused the noise, not simply that the noise was associated with the food. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
|
|
|
|
Pack, A. A., & Herman, L. M. (2004). Bottlenosed Dolphins (Tursiops truncatus) Comprehend the Referent of Both Static and Dynamic Human Gazing and Pointing in an Object-Choice Task. J. Comp. Psychol., 118(2), 160–171.
Abstract: The authors tested 2 bottlenosed dolphins (Tursiops truncatus) for their understanding of human-directed gazing or pointing in a 2-alternative object-choice task. A dolphin watched a human informant either gazing at or pointing toward 1 of 2 laterally placed objects and was required to perform a previously indicated action to that object. Both static and dynamic gaze, as well as static and dynamic direct points and cross-body points, yielded errorless or nearly errorless performance. Gaze with the informant's torso obscured (only the head was shown) produced no performance decrement, but gaze with eyes only resulted in chance performance. The results revealed spontaneous understanding of human gaze accomplished through head orientation, with or without the human informant's eyes obscured, and demonstrated that gaze-directed cues were as effective as point-directed cues in the object-choice task. (PsycINFO Database Record (c) 2009 APA, all rights reserved)
|
|
|
|
Kubinyi, E., Topál, J., Miklósi, Á., & Csányi, V. (2003). Dogs (Canis familiaris) learn their owners via observation in a manipulation task. J. Comp. Psychol., 117(2), 156–165.
Abstract: Eighty-seven pet dogs (Canis familiaris) were involved in an experiment in which they had to solve a task to obtain a ball. After witnessing a full demonstration by their owner (10 times pushing the handle of the box, which released a ball), most dogs preferred to touch the handle sooner and more frequently in comparison with other parts of the box, and they used the handle to get the ball. In contrast dogs in 3 control groups developed their own respective methods. The lack of emergence of the ball and playing after the demonstration did not affect the learning performance strongly. This suggests that in dogs the outcome of a demonstration plays only a restricted role in the manifestation of social learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
|
|
