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Bovet, D., Vauclair, J., & Blaye, A. (2005). Categorization and abstraction abilities in 3-year-old children: a comparison with monkey data. Anim. Cogn., 8(1), 53–59.
Abstract: Three-year-old children were tested on three categorization tasks of increasing levels of abstraction (used with adult baboons in an earlier study): the first was a conceptual categorization task (food vs toys), the second a perceptual matching task (same vs different objects), and the third a relational matching task in which the children had to sort pairs according to whether or not the two items belonged to the same or different categories. The children were tested using two different procedures, the first a replication of the procedure used with the baboons (pulling one rope for a category or a relationship between two objects, and another rope for the other category or relationship), the second a task based upon children's prior experiences with sorting objects (putting in the same box objects belonging to the same category or a pair of objects exemplifying the same relation). The children were able to solve the first task (conceptual categorization) when tested with the sorting into boxes procedure, and the second task (perceptual matching) when tested with both procedures. The children were able to master the third task (relational matching) only when the rules were clearly explained to them, but not when they could only watch sorting examples. In fact, the relational matching task without explanation requires analogy abilities that do not seem to be fully developed at 3 years of age. The discrepancies in performances between children tested with the two procedures, with the task explained or not, and the discrepancies observed between children and baboons are discussed in relation to differences between species and/or problem-solving strategies.
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Tomasello, M., & Call, J. (2004). The role of humans in the cognitive development of apes revisited. Anim. Cogn., 7(4), 213–215.
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Regolin, L., Marconato, F., & Vallortigara, G. (2004). Hemispheric differences in the recognition of partly occluded objects by newly hatched domestic chicks (Gallus gallus). Anim. Cogn., 7(3), 162–170.
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.
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Evans, T. A., & Westergaard, G. C. (2004). Discrimination of functionally appropriate and inappropriate throwing tools by captive tufted capuchins (Cebus apella). Anim. Cogn., 7(4), 255–262.
Abstract: A tool-throwing task was used to test whether capuchin monkeys understand the difference between functionally appropriate and functionally inappropriate tools. A group of monkeys was trained to obtain a sticky treat from a container outside their enclosure using a projectile attached to one end of an anchored line. Subsequently, these monkeys were given choice tests between functional and nonfunctional versions of tools used in training. A different feature of the tool was varied between alternatives in each choice test. The monkeys chose to use functional tools significantly more often than nonfunctional tools in early exposures to each choice test. A second experiment tested whether these subjects, as well as a second group of minimally trained participants, could distinguish between functional and nonfunctional tools that appeared different from those used in training. A new set of design features was varied between tools in these choice tests. All participants continued to choose functional tools significantly more often than nonfunctional tools, regardless of their tool-throwing experience or the novel appearance of the tools. These results suggest that capuchin monkeys, like chimpanzees studied in similar experiments, are sensitive to a variety of functionally relevant tool features.
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Jackson, R. R., & Li, D. (2004). One-encounter search-image formation by araneophagic spiders. Anim. Cogn., 7(4), 247–254.
Abstract: An experimental study of search-image use by araneophagic jumping spiders (i.e., salticid spiders that prey routinely on other spiders) supports five conclusions. First, araneophagic salticids have an innate predisposition to form search images for specific prey from their preferred prey category (spiders) rather than for prey from a non-preferred category (insects). Second, single encounters are sufficient for forming search images. Third, search images are based on selective attention specifically to optical cues. Fourth, there are trade-offs in attention during search-image use (i.e., forming a search image for one type of spider diminishes the araneophagic salticid's attention to other spiders). Fifth, the araneophagic salticid's adoption of search images is costly to the prey (i.e., when the araneophagic salticid adopts a search, the prey's prospects for surviving encounters with the araneophagic salticid are diminished). Cognitive and ecological implications of search-image use are discussed.
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Yamazaki, Y., Shinohara, N., & Watanabe, S. (2004). Visual discrimination of normal and drug induced behavior in quails (Coturnix coturnix japonica). Anim. Cogn., 7(2), 128–132.
Abstract: The ability to discriminate the physical states of others could be an adaptive behavior, especially for social animals. For example, the ability to discriminate illness behavior would be helpful for avoiding spoiled foods. We report on an experiment with Japanese quails testing whether these birds can discriminate the physical states of conspecifics. The quails were trained to discriminate between moving video images of quails injected with psychoactive drugs and those in a normal (not injected) condition. Methamphetamine (stimulant) or ketamine (anesthetic) were used to produce drug-induced behaviors in conspecifics. The former induced hyperactive behavior and the latter hypoactive behavior. The subject quails could learn the discrimination and showed generalization to novel images of the drug-induced behaviors. They did not, however, show discriminative behavior according to the type and dosage of the drugs. Thus, they categorized the behavior not on the basis of degree of activity, but on the basis of abnormality.
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Goto, K., Wills, A. J., & Lea, S. E. G. (2004). Global-feature classification can be acquired more rapidly than local-feature classification in both humans and pigeons. Anim. Cogn., 7(2), 109–113.
Abstract: When humans process visual stimuli, global information often takes precedence over local information. In contrast, some recent studies have pointed to a local precedence effect in both pigeons and nonhuman primates. In the experiment reported here, we compared the speed of acquisition of two different categorizations of the same four geometric figures. One categorization was on the basis of a local feature, the other on the basis of a readily apparent global feature. For both humans and pigeons, the global-feature categorization was acquired more rapidly. This result reinforces the conclusion that local information does not always take precedence over global information in nonhuman animals.
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Fortes, A. F., Merchant, H., & Georgopoulos, A. P. (2004). Comparative and categorical spatial judgments in the monkey: “high” and “low”. Anim. Cogn., 7(2), 101–108.
Abstract: Adult human subjects can classify the height of an object as belonging to either of the “high” or “low” categories by utilizing an abstract concept of midline that divides the vertical dimension into two halves. Children lack this abstract concept of midline, do not have a sense that these categories are directional opposites, and their categorical and comparative usages of high(er) or low(er) are restricted to the corresponding poles. We investigated the abilities of a rhesus monkey to perform categorical judgments in space. We were also interested in the presence of the congruity effect (a decrease in response time when the objects compared are closer to the category pole) in the monkey. The presence of this phenomenon in the monkey would allow us to relate the behavior of the animal to the two major competing hypotheses that have been suggested to explain the congruity effect in humans: the analog and semantic models. The monkey was trained in delayed match-to-sample tasks in which it had to categorize objects as belonging to either a high or low category. The monkey was able to generate an abstract notion of midline in a fashion similar to that of adult human subjects. The congruity effect was also present in the monkey. These findings, taken together with the notion that monkeys are not considered to think in propositional terms, may favor an analog comparison model in the monkey.
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Schwartz, B. L., Meissner, C. A., Hoffman, M., Evans, S., & Frazier, L. D. (2004). Event memory and misinformation effects in a gorilla (Gorilla gorilla gorilla). Anim. Cogn., 7(2), 93–100.
Abstract: Event memory and misinformation effects were examined in an adult male gorilla ( Gorilla gorilla gorilla). The gorilla witnessed a series of unique events, involving a familiar person engaging in a novel behavior (experiment 1), a novel person engaging in a novel behavior (experiment 2), or the presentation of a novel object (experiment 3). Following a 5- to 10-min retention interval, a tester gave the gorilla three photographs mounted on wooden cards: a photograph depicting the correct person or object and two distractor photographs drawn from the same class. The gorilla responded by returning a photograph. If correct, he was reinforced with food. Across three experiments, the gorilla performed significantly above chance at recognizing the target photograph. In experiment 4, the gorilla showed at-chance performance when the event was followed by misinformation (a class-consistent, but incorrect photograph), but significantly above-chance performance when no misinformation occurred (either correct photograph or no photograph). Although the familiarity can account for these data, they are also consistent with an episodic-memory interpretation.
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Beran, M. J. (2004). Long-term retention of the differential values of Arabic numerals by chimpanzees (Pan troglodytes). Anim. Cogn., 7(2), 86–92.
Abstract: As previously reported (Beran and Rumbaugh, 2001), two chimpanzees used a joystick to collect dots, one-at-a-time, on a computer monitor, and then ended a trial when the number of dots collected was equal to the Arabic numeral presented for the trial. Here, the chimpanzees were presented with the task again after an interval of 6 months and then again after an additional interval of 3.25 years. During each interval, the chimpanzees were not presented with the task, and this allowed an assessment of the extent to which both animals retained the values of each Arabic numeral. Despite lower performance at each retention interval compared to the original study, both chimpanzees performed above chance levels in collecting a quantity of dots equal to the target numeral, one chimpanzee for the numerals 1-7, and the second chimpanzee for the numerals 1-6. For the 3.25-year retention, errors were more dispersed around each target numeral than in the original study, but the chimpanzees' performances again appeared to be based on a continuous representation of magnitude rather than a discrete representation of number. These data provide an experimental demonstration of long-term retention of the differential values of Arabic numerals by chimpanzees.
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