Journal of Comparative Psychology最新文献

Humans are capable of recognizing the temporal organization of a rhythm by perceiving its metrical structure even when it is evoked only by temporal alterations. There is also plenty of data suggesting that several animal species can track different rhythmic cues. However, there is no clear evidence that nonhuman animals can extract metrical information from an auditory rhythm. To explore this issue, we familiarized rats (Rattus norvegicus) to auditory rhythmic sequences. We then tested them with novel sequences that presented temporal variations at the metrical, grouping, or tone duration level. We observed that the animals responded differently to the familiar versus the novel sequences, suggesting that temporal alterations are sufficient for the animals to discriminate between auditory rhythmic sequences. Likewise, the use of temporal accents could be relevant to provide metrical information, although it is still an open issue the extent to which the animals are able to induce meter from rhythmic sequences. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Sharing food with immature individuals is costly and should therefore only occur when the benefits outweigh the costs. Accordingly, sharing typically decreases when immature individuals get older and become more proficient independent foragers. Providers would gain more if they could adjust food sharing not only to immature age but also to their skill level. Such sensitivity to others' skill deficits is expected to be rare, but may be found in species with high prosociality and other-regarding preferences, such as cooperative breeders. Here, we compared the food-sharing patterns of cooperatively breeding common marmosets (Callithrix jacchus) and closely related but independently breeding squirrel monkeys (Saimiri boliviensis) under two conditions. In the baseline condition, food was easily accessible whereas in the experimental condition, individuals had to solve a puzzle to access the food. We found that the cooperatively breeding marmosets, but not the independently breeding squirrel monkeys, shared more when immatures lacked the skill to obtain the food from the apparatuses. Skill sensitivity might be associated with the presence of other-regarding preferences and a strong proclivity to proactively share food during baseline conditions. This proclivity has evolved in marmosets, but not squirrel monkeys, in the context of cooperative breeding and may facilitate the emergence of skill recognition, information donation, and teaching. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Photophobia, aversion for brightly lit environments, is commonly observed in laboratory nocturnal rodents such as mice and rats, as indicated, for example, by the light-dark box test. The universality of photophobia in laboratory nocturnal rodents rises questions on its corresponding behavior in nature and on what adaptive value may have led to the selection of this behavior during biological evolution. Nocturnality alone is insufficient to explain photophobic behavior, as nocturnal rodents show reduced roaming in the day just because they are sleeping and not because they are choosing to avoid a possibly aversive daylight. On the other hand, a natural behavior more directly related to the photophobia observed in the laboratory is selenophobia (moonlight avoidance), which in free-ranging rodents can be operatively defined as the reduction of exploratory and foraging activities in moonlit nights compared with dark nights. In the case of selenophobia, factors related to nocturnality are ruled out, and light-related factors can be easily isolated. Selenophobia has been found in a wide variety of nocturnal rodents, for which it may represent an antipredatory adaptation. A technology-aided study of selenophobia may strongly contribute to a better understanding of its nature, of the relative contributions of instinct and learning to this behavior, and of its neural underpinnings. In particular, new behavioral and neurophysiological technologies, for example, miniaturized radiocollars, freely accessible testing chambers equipped with infrared video cameras, animal-borne miniaturized video cameras, and noninvasive electrophysiological recordings, may be of particular usefulness to shed light on selenophobia. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Like many other species, dogs have a natural quantity judgment system to assist with decision making to maximize resources. Additionally, dogs are highly sensitive to, and influenced by, human-delivered ostensive (i.e., social) cues. Here, we assessed the influence of one such cue-a high, rising, positive "Oooh!" sound-on dogs' choice of differing quantities of pieces of food presented on two different plates. Subjects (N = 29) received 16 randomized trials of four conditions: 1 versus 1 paired with experimenter "Oooh!" while looking at the one plate, 1 versus 3, 3 versus 1 paired with experimenter "Oooh!," and 1 versus 1. As predicted, dogs chose the larger quantity more often in 1 versus 3 conditions. Contrary to one of our predictions, subjects chose the 1 versus 1+ "Oooh!" at chance levels. However, in support of another prediction, pairing the smaller reward with a positive intonation in 3 versus 1+ "Oooh!" significantly reduced dogs' choice of the larger reward. That is to say, without the presence of words, eye contact, or facial expressions, dogs followed a misguiding cue and chose a smaller reward that a stranger had deemed more valuable than a larger one. Local enhancement as well as a drive to increase social capital with the human are discussed as possible explanations. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Typical approaches to study self-control present subjects with a simultaneous choice between a larger-later (LL) reinforcer and a smaller-sooner (SS) reinforcer. In contrast, in patch-leaving tasks, subjects choose between staying at a patch for an SS (or LL) reinforcer and leaving for an LL (or SS) reinforcer. Previous studies show that blue jays, monkeys, humans, and rats prefer the SS reinforcer in binary-choice tasks, whereas the same subjects prefer the LL reinforcer in equivalent patch-leaving tasks. The current study systematically replicated this research using pigeons. Six pigeons responded in a binary-choice task and in two patch-leaving tasks in which staying led to an LL (Patch-L) or SS (Patch-S) reinforcer. Across conditions, the SS reinforcer delay varied from 5 to 55 s; the LL reinforcer delay was always 60 s. In binary-choice conditions, subjects preferred the SS reinforcer. In Patch-L and Patch-S conditions, subjects preferred the LL and SS reinforcer, respectively, reflecting a bias to stay at the patch. This bias persisted when the stay response was more effortful and when the delays to both reinforcers were equal. This may reflect a species-specific win-stay bias and the differential consequences of staying (which led to a stimulus signaling food) versus leaving (which led to a stimulus never associated with food). Thus, we propose a conditioned-reinforcement account of intertemporal choice in patch-leaving contexts. We suggest several avenues for further investigations of the mechanisms underlying intertemporal choice in different contexts and question the economic equivalence of the operant and patch-leaving procedures. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Music is a ubiquitous feature of human behavior. Yet the origins of human musicality remain poorly understood. One attractive approach has investigated the distribution and components of musicality among nonhuman animals. Here I tested four highly trained pigeons in three experiments for their capacity to discriminate the intervals of the chromatic scale. Using an auditory go/no-go same/different task, the pigeons discriminated intervals spanning different numbers of semitones on each trial as synthesized with two musical instruments (cello and organ). Experiment 1 examined this discrimination using a successive melodic context, while Experiment 2 used a simultaneous harmonic context. Experiment 3 tested pure tones in both contexts. The pigeons were sensitive to the distance among the pitch intervals, but examination of specific diagnostic intervals revealed little evidence for any contribution of human-like musical consonance (perfect fifth and octave) and dissonance (tritone and major seventh) to the discrimination. Although more accomplished in the auditory modality than widely assumed, the current state of the evidence suggests pigeons, while sensitive to the pitched nature of sound, lack essential capacities needed for music perception. The evolutionary implications for the comparative psychology of music are considered. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Striped skunks are omnivorous generalists with patchily distributed food-two selection pressures that are purported to drive the evolution of cognition. Despite this, the cognitive abilities of skunks have rarely been tested. Using the slat-pulling task, we assessed the ability of three striped skunks to reason about the visual patterns of support when two slats were presented (one supporting a food item). We used both functional slats (real wooden slats that gave subjects both visual and functional information when manipulated) and purely representational slats in an arbitrary version of the task (painted lines that provided only visual information). All three skunks found the arbitrary task difficult to learn but nevertheless learned to solve it after thousands of trials. They appeared to respond to visual patterns of contact and perceptual containment between food and painted lines to solve several configurations of the task. Interestingly, only one of three skunks learned to pull supportive over unsupportive slats (despite the addition of functional information). This subject had first learned the visual pattern associated with reward in the arbitrary version, thus showing the transfer of visual patterns from the arbitrary to the functional task. Overall, striped skunks demonstrated the ability to use visual patterns to solve problems despite their relatively poor vision and difficulty in learning the tasks. These findings provide further support for the idea that slat-pulling tasks can be solved by visual pattern learning alone and that this possibility needs to be controlled for in tasks assessing abstract causal reasoning. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Detection dogs are required to learn and alert to multiple different odors during training and to generalize this learning to similar odors when working. They should be both sensitive to variation in the target odors and specific enough to avoid false alerts, but how readily they achieve this is likely to depend on the training method employed. The majority of agencies train by presenting single target odors in isolation, and adding additional odors consecutively, although recent research with rats suggests intermixing the target odors concurrently throughout training may be a more effective approach. This study therefore tested the relative efficacy of intermixed training in dogs. Using an odor-detection lineup, pet dogs were trained to detect two target odors, A and B. Those allocated to the "sequential" group were trained to criterion on odor A and then trained on odor B (or vice versa), the "compound" group were trained on a mixture of AB, and the "intermixed" group trained on A and B concurrently. Each dog was then tested on all combinations of the test stimuli (A, B, and AB), as well as combinations containing a novel interferent (AC, BC, and ABC). Results revealed that dogs trained by the intermixed method made significantly more correct (true positive) indications, and significantly fewer miss (false negative) indications than the other two methods, suggesting that intermixed training is more effective than currently used alternative training methods. Thus, for improved performance and generalization, we recommend detection dog training should use an intermixed method of training. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Play behavior has been extensively studied across species, but its direct role in social relationships remains unclear. Here we use an "isolation versus separation" protocol to identify behaviors associated with relationship renewal in adolescent female rats. Members of a dyad that had been separated for 24 hr, without isolation from other peers, initially increased investigative behaviors relative to nonseparated peers; however, in contrast with social isolation, separation by itself did not increase rough-and-tumble play. The data suggest that increased play following isolation depends on general motivations, rather than a "peer-specific" drive to renew relationships with an individual. This is consistent with a role of play in more general social learning rather than reestablishing bonds or expectations. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Drugs, bomb materials, fruits, and even medical conditions such as cancer are all stimuli that a dog's nose can be trained to detect, and the dog then can report reliable information about those stimuli in terms of presence or absence. This essay discusses the tremendous effort that goes into training expert detection dogs, highlighting different ways of instantiate training. (PsycInfo Database Record (c) 2025 APA, all rights reserved).