Animal Cognition最新文献

When rewards occur after a delay, signals that the wait will be shorter than average can be valuable. A recent study by Macias et al. (2024) found that pigeons preferred an alternative providing signals for a short or long delay to food over an alternative that provided no signals about delay. Preference for the signalled alternative increased with increases in the ratio of the long to short delay, with the average delay held constant. Here we report a preregistered experiment that tested the effect of changing the average delay, with the ratio of long to short delays held constant. Pigeons preferred the signalled alternative, and this preference was higher at longer delays (20 s and 40 s) than shorter delays (2 s and 4 s). This finding is opposite to the predictions from the modified Delta-Sigma model proposed by Macias et al., but fits well with predictions of the Signal for Good News (SiGN) model, which assumes that signals for a reduction in delay to reward reinforce choice.

Accurate detection of pathologies like pulmonary lung nodules is critical as they can be a marker of a potential cancerous, life-threatening condition. The detection of such nodules, however, is a difficult visual task requiring extensive radiological training. But, considering this process as a perceptual categorization task generates avenues for using pigeons to understand the underlying visual processes as these birds are experts at categorizing objects and behaviors visually, using a highly flexible and accurate visual cognition. Using a go/no-go paradigm, we presented six pigeons with short movies of CT sections that contained a solid lung nodule (Abnormal) or CT sections without nodules (Normal). Half the pigeons were reinforced for pecking during Abnormal, and the other half during Normal. Pigeons learned to detect the nodules and generalized their discrimination to novel exemplars, indicating the use of implicit visual categorization processes. Critically, this categorization transferred to different, visually distinct abnormalities (emphysema and ground glass nodules). Hence, pigeons can be employed as an animal model for evaluating perceptual processes during abnormality detection and may give insight into novel radiological training optimized by pigeons’ implicit visual cognitive mechanisms instead of explicit didactic instruction.

Prosocial behaviors, such as cooperation and food sharing, are critical for maintaining group cohesion in social species, yet the influence of transient physiological states on these behaviors remains poorly understood. This study investigates how short-term ecological factors impact social behavior in common marmosets (Callithrix jacchus), a highly prosocial nonhuman primate species. Specifically, we tested how food divisibility (small vs. large food items) and time since food access (TSFA; 0 h, 1 h, and 3 h) influenced food sharing behavior. Results revealed that larger food portions consistently promoted prosocial interactions, while longer durations since food access shifted behavior toward individualism. No significant interaction effect between TSFA and food size was observed. These findings suggest that marmoset prosociality is sensitive to immediate ecological conditions, reflecting flexible, context-dependent social decision-making.

The capacity to understand the intentions of other agents is a useful capacity for all social organisms. Several studies to date have explored whether domesticated dogs (Canis familiaris) share this capacity. Although previous studies show that dogs behave differently toward humans who are unable versus unwilling to share food, it remains unclear whether dogs can use this information to guide broader social decisions such as partner selection. We therefore asked whether dogs would rely on an agent’s intentions—being unable versus unwilling to give food—when choosing whom to approach. In four within-subjects experiments (total N = 86), we gave dogs a choice between two experimenters: an unable experimenter who tried but failed to deliver a reward and an unwilling experimenter who intentionally withheld it. We found that dogs preferred to approach the unable over the unwilling experimenter but only in cases where they were familiarized to the two agents using an asymmetric but predictable reward schedule. Dogs showed no preference for an unable over an unwilling experimenter when given no rewards (Experiment 1), when receiving rewards from both experimenters’ sides (Experiment 2), or when rewards were delivered randomly between the experimenters’ sides (Experiment 4). Dogs showed a clear preference only when a single experimenter’s side was consistently paired with a reward in Experiment 3, regardless of that experimenter’s role. These results suggest that dogs can exploit intention information when choosing social partners, but only under specific motivational contexts.

This narrative review synthesises current knowledge on the effects of habitat complexity, defined as the variation in physical structures within ecosystems, on fish cognition, brain morphology, and personality. Globally, habitat complexity is declining through a process known as habitat simplification, with largely unknown effects on animal cognition. Owing to their remarkable diversity and capacity for neural plasticity, fish provide an ideal model for investigating these cognitive consequences. We first examine how habitat complexity shapes brain structure both between and within species. The results highlight that species from more complex habitats often evolve larger brains and specific brain regions, like the telencephalon and cerebellum, which are crucial for advanced cognitive and motor functions. Conversely, a lack of structural complexity, such as experienced in hatchery environments, can lead to smaller brains in fishes, though this effect can be mitigated by physical environmental enrichment. The paper then explores the impact of habitat complexity on four key areas of fish cognition, i.e., general cognition including simple learning and executive functions, spatial cognition, social cognition, and numeracy. We then propose an intricate three-way interaction between habitat complexity, personality, and cognition, whereby changes in habitat complexity can indirectly alter cognition via changes in personality. The review concludes by identifying areas for future research and warns that the continued simplification of aquatic habitats may pose a significant threat to the cognitive abilities and adaptive capacity of fish in an increasingly altered world.

Labelling has a pronounced effect on increasing infants’ attention to objects. At the same time, infants actively seek social cues when presented with novel objects and early signs of communicative intent are considered essential for language learning. Although no other species has been shown to possess language in its integrity, a small group of rare individual dogs (Gifted Word Learners, GWL) shows a limited subset of language-related skills: the capacity to form an extensive vocabulary of object verbal labels rapidly. Comparing these dogs to typical dogs that lack this capacity provides a unique opportunity to study the relationship between vocabulary acquisition and other cognitive traits in a non-human, non-linguistic species that evolved and developed in the human environment. The present study compares the object preferences and tendency to seek social interactions of GWL (N = 10) and typical (N = 21) dogs. During a two-week familiarisation phase, the caretakers and the dogs engaged in play with four dog toys, only two of which were labelled. In contrast, the other two were not labelled during the playful interaction. The subsequent test phase consisted of two trials in which these four toys, along with two novel ones, were placed on the floor, and the caretakers remained passive. The dogs were given 90 s to explore freely. The results did not provide evidence for significant differences between GWL dogs and T dogs’ exploration of the labelled, unlabelled and novel objects. GWL dogs, however, demonstrated a significantly higher propensity to interact with their caretakers while holding a toy in their mouths, notably, mainly presenting the novel toy to their caretakers. GWL dogs’ tendency to interact with the passive caretaker may suggest a greater interest in the social aspect of interacting with objects.

Response inhibition - the ability to suppress or stop actions - is crucial for adaptive behaviour across species. In Part 1 of this study, we presented a conceptual framework for understanding response inhibition as multifaceted. Specifically, we conceptualised response inhibition as a race between a ‘go runner’ and a ‘stop runner’. These runners are modulated by the type of stimulus that triggers the runner, the relative timing between stimuli, and the type of actions that are elicited. In Part 2, the framework is used to make predictions about correlations between different measures of response inhibition across three tasks: the detour barrier task, the thwarting task, and the stop-change task. These predictions were tested in two closely related bird species: herring gulls (Larus argentatus) and lesser black-backed gulls (Larus fuscus). The correlations between specific measures of response inhibition were generally weak. This pattern of results supports the idea that response inhibition is not a unitary ability, but rather a set of partly independent components. These findings highlight the importance of task context and trigger type in shaping inhibitory performance, and they illustrate how conceptual and mathematical models can guide more nuanced interpretations of inhibition across different ecological and experimental settings.

Musicality is the predisposition to process and produce music. In human beings, processing and producing music often involves entrainment, the ability to synchronise behaviour to external auditory rhythms. Most non-human primates have limited entrainment skills; its search in other taxa has shown cases of entrainment much more advanced than any non-human primate in a few taxa, among which birds. Finding convergently-evolved entrainment abilities in several species may highlight shared evolutionary origins. Here, we investigate spontaneous vocal entrainment in rooks, a social corvid, using non-biologically relevant stimuli. We exposed individual rooks to sound sequences varying in tempo and metrical structure, and tested the effect of these two manipulations on temporal adjustments in their song. Of the 11 birds tested, eight sang while listening to the stimuli. Three of them sang often enough for us to analyse their responses to most tempos and meters. We found that two of these individuals were influenced by particular tempi and/or metrical structures: one bird produced shorter vocalisations at slower tempo and another reduced the intervals between its vocalisations upon hearing isochronous sequences with a unary metre and slow tempo. Still, the timing of the start of their vocalisations did not match accurately the timing of the beat of the stimuli. Our results provides additional data on vocal flexibility in this vocal learning species. We cannot exclude that rooks may have attempted to vocally entrain, but the possibility will require further investigations. Despite their evolutionary distance from humans, rooks, and possibly other corvids and songbirds, are interesting species for future studies on rhythmic perception, and could help shed light on convergently evolved building blocks of human musicality.

Cognitive performance in animals can be assessed through the detour task, which challenges spatial navigation, decision-making, and behavioral flexibility. The most common versions of the detour task often fail to involve processing of different environmental cues, the adjusting of behavior to varying obstacles, and motivation, factors that are likely important for cognitive performance. In this study, we aimed to validate a new method for assessing cognitive performance—a detour task with increasing levels of difficulty—using the reef fish Stegastes fuscus. We evaluated the ability of individuals to traverse a 150 cm-long tank in which barriers with doors were progressively introduced across test days, increasing task complexity and requiring flexible detour strategies. Two groups were tested: one with a conspecific as a social stimulus and one without any stimulus. The results revealed that S. fuscus employed different behavioral strategies to complete the task, suggesting spatial learning, route planning, and possible memory use, especially when the social stimulus was present. This novel detour paradigm highlights the species’ cognitive capacity to solve progressively complex spatial challenges. Understanding how stimulus respond to increasing task demands provides valuable insights into animal cognition and behavioral ecology.

The performance of detection dogs relies on their ability to detect and alert to variations of the stimuli upon which they have been trained. As such, research has tended to focus on understanding the likelihood of generalising beyond a trained stimulus set. However, it remains unclear which stimuli dogs perceive as the ‘same’ or ‘different’ to others. Understanding this perception would allow the creation of appropriate training aids to improve the performance of working dogs. The aim of this study was to establish whether dogs were capable of same-different concept learning with odours and whether they could generalise this learning to a novel stimulus set. Dogs were presented with two odours simultaneously and trained to give one indication behaviour if the samples were the same, and an alternative indication if they were different. Four of the ten dogs tested were able to meet the learning criteria, indicating that they could learn the task with the training stimuli. However, none were able to generalise the concept to a new stimulus set. The failure of the dogs to generalise the same-different learning to novel stimuli suggests that the procedure used, while showing some promise, may not be the best approach to assess how dogs perceive odours in relation to each other.