Journal of Comparative Psychology最新文献

Many animals navigate in a structurally complex environment, which requires them to detour around the physical barriers that they encounter. Although many studies in animal cognition suggest that they are able to adeptly avoid obstacles, it is unclear whether a new route is learned to navigate around these barriers and, if so, what sensory information may be used to do so. We investigated detour learning in traveling up a tree in the Australian bull ant, Myrmecia midas, which primarily uses visual landmarks. We first placed a barrier on the ants' upward path. Initially, 46% of foragers were unsuccessful in detouring the obstacle. On subsequent trips, the ants became more successful and established a new route. We observed up to eight successful foraging trips detouring around the barrier. We then tested the same foragers in a series of manipulations, including changing the position of the barrier, making a new gap in the middle of the obstacle, or removing the barrier altogether. The ants mostly showed the same learned motor routine, detouring with a similar path as in the initial trials, suggesting that foragers were not relying on barrier cues and therefore learned a new route around the obstacle. When foragers encountered new olfactory or tactile cues, or the visual environment was blocked; however, their navigation was profoundly disrupted. These results suggest that changing sensory information drastically affects the foragers' navigational performance. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Recent psychophysical experiments have shown that zebra finches (Taeniopygia guttata-a songbird) are surprisingly insensitive to syllable sequence changes in their species-specific motifs while budgerigars (Melopsittacus undulatus-a psittacine) do much better when tested on exactly the same sounds. This is unexpected since zebra finch males learn the order of syllables in their songs when young and sing the same song throughout adulthood. Here we probe the limits of this species difference by testing birds on an order change involving just two syllables, hereafter called bi-syllable phrases. Results show budgerigars still perform better than zebra finches on an order change involving just two syllables. An analysis of response latencies shows that both species respond to an order change in a bi-syllable motif at the onset of the first syllable rather than listening to the entire sequence before responding. Additional tests with one syllable omitted or doubled, or with white noise bursts substituted for syllables, indicate that the first syllable in the sequence has a dominant effect on subsequent discrimination of changes in a bi-syllable pattern. These results are surprising in that zebra finch males sing their full motif syllable sequence with a high degree of stereotypy throughout life, suggesting that this consistency in production may not rely on perceptual mechanisms for processing syllable order in adulthood. Budgerigars, on the other hand, are quite sensitive to bi-syllable order changes, an ability that may be related to useful information being encoded in the sequence of syllables in their natural song. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

In an early scientific description of navigation (finding one's way from a known location to a known destination) in an arthropod, Charles Turner, one of comparative psychology's staunchest early proponents of studying individual variation. The field of comparative psychology has caught up with Charles Turner. In this essay, the author presents an overview of the results of previous studies which suggest that several species of ants use vision effectively to navigate in three dimensions, in daylight, and in darkness. Bull ants, a species that navigates in dim light, have large compound eyes containing receptors that are sensitive to ultraviolet (UV), blue, and green regions of the electromagnetic spectrum. Islam et al.'s findings illustrate a very general point about behavior that comparative psychologists do (and should continue to) take seriously, theoretically, and empirically. When we take the time to look closely, the behavior of individuals varies in biologically and psychologically important ways, no matter the size of their bodies or nervous systems. The adaptability of individuals arises from variation within the individual over time, manifest in this study as the adoption of novel routes as circumstances required. The adaptability of populations arises from variation across individuals, evident in this study in ants that learned to travel directly to the edge of the barrier and ants that learned to travel directly to the barrier, then make a right-angle turn to travel along it to an edge. The sources and consequences of behavioral variability, within and across individuals, and its manifestations across species, must remain core concerns for comparative psychology, as they were for Charles Turner more than 100 years ago. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Two experiments employing an identity matching-to-sample procedure were carried out to clarify the factors affecting global-local visual processing of capuchin monkeys (Sapajus spp.) in comparison with humans. In the first experiment, we assessed the relative ability of the two species to discriminate high, medium, or low spatial frequencies (HSFs, MSFs, or LSFs). Then, in a second experiment, we determined if the use of a procedure designed to induce a bias toward attending given spatial frequencies could produce a top-down or selection-history modulation of global-local visual processing in capuchins and humans. In the first experiment, monkeys discriminated better HSFs. By contrast, humans discriminated better MSFs and LSFs. The second experiment showed an effect of SF processing on global-local processing in both species. However, this effect was confined to local trials only and occurred under different conditions in the two species. In monkeys, it occurred following a bias toward attending HSFs, whereas in humans, it occurred following a bias toward attending LSFs. These results provide new information about the relative sensitivity of humans and capuchins to different spatial frequencies in vision. Moreover, they suggest that global-local visual processing can be modulated in both humans and monkeys by processes that are not confined to attending one or the other level of stimulus structure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

concept formation was once thought to be a uniquely human ability. An increasing variety of nonhuman species have demonstrated aspects of this ability, however, suggesting that conceptualization is a widely shared aspect of cognition. The capacity to form a concept of same-different, in particular, has now been shown in pigeons, primates, bottlenose dolphins, sea lions, and more. Traditional methods of studying abstract concept formation include matching-to-sample (MTS), same/different (S/D), and relational-matching-to-sample tasks, tasks that typically require animals to discriminate sets of planar images. Some of these methods may actually test familiarity, memory, associative learning, or other phenomena rather than a concept of same-different. In the current study, we tested same-different concept formation in domestic dogs using a variation on the S/D task that required subjects to discriminate sets of three-dimensional objects. This method avoids some pitfalls of matching-to-sample and S/D tasks that use two-dimensional images and thousands of training trials. Dogs were able to learn to classify sets of objects as "same" and "different" and proved to be able to immediately transfer this ability to novel sets, including sets of only two objects. Domestic dogs are promising subjects for future studies of same-different conceptualization due to their widespread availability and willingness to work cooperatively with humans. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

An open question in comparative psychology is whether the source of correlations among different measures of ability (the g factor) is shared between species, or is distinct. This is examined using data on the performance of three monkey species (tufted capuchins, black-handed spider monkeys, and long-tailed macaques) on 16 cognitive ability measures. The differences between species pairs across measures are not generally strongly related to the degree to which the g factor loads on each subtest. Iteratively removing the subtests with the lowest coefficients of variance (CV), and recorrelating the species differences with subtest g-loadings was found to increase the association between the two. Across iterations, subtest pooled CV strongly and positively predicts the increase in the degree to which g-loadings are predictive of species difference in two comparisons, but is a weaker predictor in the comparison between tufted capuchins and black-handed spider monkeys. These associations were not related to phylogenetic distance but were very strongly related to species differences in the means of certain ecological factors. g-scores computed for each species on the basis of the three subtests with the highest CV values exhibited very-high magnitude (>.9) associations with species-level G-scores. G is simply the species-level equivalent of g, resulting from covariation among cognitive ability measures at the level of species differences. Finally, as with previous studies, subtests that show the greatest species differences seem to draw on executive functioning, and attention, suggesting that these may be a phylogenetically conserved source of g across many animal taxa. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Comments on an article by Limor Raviv et al. (see record 2023-07345-001). Raviv et al. argue that the conflicting findings from human language and from studies of communication in nonhuman animals boil down to different levels of analysis used by researchers studying non-humans compared with those studying humans. Researchers studying nonhuman animal communication typically focus on the size of signal repertoires or the structural variation within and among signals within a repertoire. Researchers studying human language, conversely, largely focus on the question of grammatical rules that govern the way units (words and phrases) are put together in speech streams. Rules of composition that govern the way units are put together are considered more complex in nonhuman signaling systems, but simpler in human language systems. The discrepancy here, according to Raviv et al., stems from two sources. According to the commenting authors, the take home message of Raviv et al. is one that will be helpful to future studies of the evolution of communication systems. Raviv et al. recommend that we work harder to avoid terms such as "complex" and "simple" with regard to communication and instead focus on the specifics of what we are analyzing. Phrases such as "larger repertoire size" or "stronger compositional structure" represent cleaner and more neutral phrases for discussions of communication and would better allow findings from non-humans and from humans to be compared. Finally, Raviv et al. advocate for greater collaborative work across nonhuman and human communication systems, and interdisciplinary work has a long history of fundamental discoveries. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Visual illusions are of particular interest to cognitive researchers because they reflect the active role of the brain in processing the world around us. Yousif and Scholl (2019) recently described a new visual experience, the one-is-more illusion, in which adult humans perceived continuous objects as longer than sets of discrete objects of equal length. In the current study, we investigated this phenomenon in human children (Homo sapiens) and rhesus macaques (Macaca mulatta). Children were presented with a computerized 2-choice discrimination task and successfully selected the longer of 2 images for control trials. On trials in which 2 versions of the same image were presented (identical in length), and one was of a continuous form and the other consisted of 2 or more distinct units, children showed a bias for the continuous object. Monkeys were given the same computerized task and learned to choose the longer of 2 otherwise identical stimuli. However, monkeys did not show a bias to choose the continuous probe images as longer than the discrete images in the critical test trials with equal-length stimuli. These results are discussed in light of developmental and comparative research on related illusory experiences and perceptual mechanisms. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Associating with kin provides individual benefits but requires that these relationships be detectable. In humans, facial phenotype matching might help assess paternity; however, evidence for it is mixed. In chimpanzees, concealing visual cues of paternity may be beneficial due to their promiscuous mating system and the considerable risk of infanticide by males. On the other hand, detecting kin can also aid chimpanzees in avoiding inbreeding and in forming alliances that improve kin-mediated fitness. Although previous studies assessing relatedness based on facial resemblance in chimpanzees exist, they used images of captive populations in whom selection pressures and reproductive opportunities are controlled and only assessed maternity or paternity of adult offspring. In natural populations, the chances of infanticide are highest during early infancy, suggesting that young infants would benefit most from paternity concealment, whereas adults and subadults would benefit from the detection of all types of kin, including half-siblings. In our experiment, we conducted an online study with human participants, in which they had to assess the relatedness of chimpanzees based on facial similarity. To address previous methodological constraints, we used chimpanzee images across all ages, as well as maternal and paternal half-siblings. We found that kin status was detected above chance across all relatedness categories, with easier kin detection of father-offspring pairs, females, and older chimpanzees. Together, these findings support the existence of paternity confusion in infant chimpanzees and provide a possible mechanism for incest avoidance and kin-based social alliances in older individuals. (PsycInfo Database Record (c) 2022 APA, all rights reserved).