Animal Cognition Research Articles

Sex-specific effect of long-term fluoxetine exposure on inhibitory control in guppies (Poecilia reticulata)

Environmental contamination with psychoactive drugs poses a serious hazard to wildlife. However, the long-term effects of these bioactive pollutants on animal cognition, a key fitness-enhancing trait, remain unknown. For five years, we exposed multiple generations of guppies (Poecilia reticulata) to environmentally relevant concentrations (0 ng/L, 30 ng/L, 300 ng/L) of the common antidepressant and ubiquitous freshwater pollutant fluoxetine. We aimed to investigate potential transgenerational effects of fluoxetine by comparing an unexposed control population to two exposed populations 10 months after fluoxetine addition was halted. We used a well-established inhibitory control assay to quantify guppies’ cognition, and we measured a key personality trait, ‘boldness’. There was a sex-specific, non-monotonic effect of fluoxetine on cognition. Females in both fluoxetine-exposed groups had significantly lower inhibitory control than unexposed females. By contrast, fluoxetine-exposed males did not differ in their cognitive ability from control (i.e., unexposed) treatment males, but males from the high-concentration treatment had greater inhibitory control than those from the low-concentration treatment. Males from the high-concentration treatment were marginally bolder than those from the low-concentration treatment. Our results are the first evidence that long-term fluoxetine exposure affects inhibitory control in non-humans and highlight the importance of considering the cognitive and legacy impacts of psychoactive pollution on wildlife.

Using Online Media To Study Animal Cognition: Domestic Cat Responses To Reflective Images

In the mirror test of visual self-recognition, if an animal responds to its reflection as its own, rather than how it would respond to a novel individual, the animal may have the capacity to recognize itself in mirrors. Previous studies have offered little information about self-recognition of domestic cats. Here we explore two phenomena that may shed light on whether cats recognize their own reflections or reflective images by gleaning data from social media. We examine TikTok videos where pet owners show cats reflective images with augmented reality (AR) filters; and YouTube videos where cats interact with mirrors. Behavioral sequence analysis revealed little support that cats understand reflective images. Few TikTok cats responded to augmented reality images, and their responses may have been triggered by other cues, such as human touch. In YouTube videos, cats fell into five behavioral clusters, two which were aggressive, and two which were curious. Even curious cats showed little evidence that they have the prerequisite conditions to be tested for mirror self-recognition. We consider whether distinct clusters may indicate that cat personality influences how cats respond to their reflections. We discuss the utility of social media for addressing questions of animal cognition.

Animal Cognition and Animal Welfare: A Review

The cognitive abilities of farm animals, particularly dairy cattle, play a crucial role in their adaptation to and interaction with their surroundings, influencing their performance, welfare and the safety of handlers. Despite the growing recognition of the importance of cognitive capabilities in animal welfare assessment, there remains a limited understanding of the cognitive repertoire of farm animals. Animals can acquire, process, store and act upon information from their environment through a variety of cognitive processes, including perception, learning, memory and decision-making. In order to address the behavioural and cognitive needs of farm animals and eventually improve their welfare and performance, housing systems and management techniques must be tailored with an understanding of these cognitive mechanisms. The practice of removing calves from their mothers immediately after birth, although aimed at disease control and ease of management, raises concerns regarding calf welfare and cognitive development due to social isolation. By providing cognitive enrichment opportunities, such as social interaction and environmental stimulation, animals can develop coping mechanisms for stressful events and enhance their ability to adapt to environmental changes. Moreover, the interconnection between cognition and welfare is complex, with cognitive processes influencing and being influenced by welfare conditions. This bidirectional relationship underscores the importance of considering cognitive functioning in welfare assessment and management practices. It highlights the need for further research to advance our knowledge of farm animal cognition and its implications for welfare and performance.

Postbiotics as a therapeutic tool in Alzheimer's disease: Insights into molecular pathways and neuroprotective effects.

Postbiotics as a therapeutic tool in Alzheimer's disease: Insights into molecular pathways and neuroprotective effects.

Animals as Artists: An Interdisciplinary Conversation on German Copyright Law

The article discusses the question of animal authorship under German copyright law and argues for the advancement of legal research through interdisciplinary conversations. It sets out by outlining the key aspects of German copyright law and arguments from legal discourse and then moves on to discussing those elements within this discourse with the potential for meaningful revisions of current legal practice: the definition of the artwork as an entity uniquely tied to human creators, the notion of creativity and its connection to ‘human dignity,’ and the exclusiveness of current definitions of personhood. It suggests a conversation with various disciplines subsumed under the moniker of the environmental humanities, particularly animal philosophy and ethics, artistic practice and art theory, and environmental anthropology and the comparative study of legal cultures. Such a conversation, it is argued, offers a rich archive and toolkit for revising and advancing legal theory and practice, no least in better alignment with scientific insights into animal cognition and behaviour, but also with greater attention to non-western legal practice.

Common marmosets (Callithrix jacchus) excel in a one-trial spatial memory test, yet perform poorly in a classical memory task

When quantifying animal cognition, memory represents one of the most tested domains and is key to understanding cognitive evolution. Memory tests thus play an important role in comparative cognitive research, yet slight variations in the experimental settings can substantially change the outcome, questioning whether different memory tests tap into different memory systems or whether they test memory at all. Here, we first assessed memory performance of 16 common marmosets (Callithrix jacchus) in two distinct paradigms varying in their format and delay. First, we examined marmoset memory in a 24-h delay memory test (24 h-DMT) in which they could freely explore an environment with three novel objects of which one contained food. We examined their retention the day after, and the procedure was iterated cumulatively with previous objects remaining in the enclosure until the marmosets had to choose the correct out of 30 objects. Second, we administered a classical delayed response test (DRT) in the same animals with three objects and a maximum delay of 30 s. In the DRT, marmoset performance was poor and not better than chance after 15 s already. However, individuals excelled in the 24 h-DMT, performing above chance level after 24 h even with tenfold the number of objects to choose from compared to the DRT. Moreover, individual performances in the two tests were not correlated, and typical age effects on memory could not be detected in both experiments. Together, these results suggest that the two tests explore different domains, and that the 24 h-DMT examines long-term memory. The outcome of the DRT is more difficult to assign to memory since individuals performed only moderately even in the 0-s delay condition. This puts into question whether this task design indeed tests memory or other cognitive processes.

Effects of Acetylcholinesterase Inhibition on Animal Cognition: Implications for Nerve Agent Exposure Risk and Potential Countermeasures (Abstract ID: 159152)

Effects of Acetylcholinesterase Inhibition on Animal Cognition: Implications for Nerve Agent Exposure Risk and Potential Countermeasures (Abstract ID: 159152)

Associative learning in pairs tends to reduce individual differences in performance: An experiment with zebra finches (Taeniopygia guttata).

Associative learning in pairs tends to reduce individual differences in performance: An experiment with zebra finches (Taeniopygia guttata).

The Animal-AI Environment: A virtual laboratory for comparative cognition and artificial intelligence research

The Animal-AI Environment is a unique game-based research platform designed to facilitate collaboration between the artificial intelligence and comparative cognition research communities. In this paper, we present the latest version of the Animal-AI Environment, outlining several major features that make the game more engaging for humans and more complex for AI systems. These features include interactive buttons, reward dispensers, and player notifications, as well as an overhaul of the environment’s graphics and processing for significant improvements in agent training time and quality of the human player experience. We provide detailed guidance on how to build computational and behavioural experiments with the Animal-AI Environment. We present results from a series of agents, including the state-of-the-art deep reinforcement learning agent Dreamer-v3, on newly designed tests and the Animal-AI testbed of 900 tasks inspired by research in the field of comparative cognition. The Animal-AI Environment offers a new approach for modelling cognition in humans and non-human animals, and for building biologically inspired artificial intelligence.

Cognitive ecology of surprise in predator–prey interactions

Abstract In this review, we relate theoretical work on the importance of surprise in cognition to empirical research relevant to surprise in predator–prey interactions. There have been multiple proposals as to how surprise should be defined and quantified in the context of animal cognition, including contributions from associative learning, information theory, Bayesian inference and the recent framework of active inference. We argue that active inference provides a novel and powerful approach to quantifying surprise and advances the field by revealing how proactive behaviour on the part of predators relates to reducing surprise. The active inference framework encompasses both proximate (e.g. neurobiological) and ultimate (evolutionary) aspects of surprise and brings new insights into key aspects of prey defences that exploit predator surprise. We focus on surprise in defences that involve a sudden change in prey appearance (such as deimatic displays), and in defences that increase prey unpredictability (such as variation in chemical defences). We review literature that have investigated these phenomena and connect them to active inference. We also consider how multiple prey defences impact surprise in predators. Finally, we consider the implications of active inference for future studies of predator–prey interactions, illustrate how this approach can be used to quantify surprise in prey defences and predict predator behaviour, and outline key questions that can be addressed within this framework. Read the free Plain Language Summary for this article on the Journal blog.

Enhancing cognitive functions in aged dogs and cats: a systematic review of enriched diets and nutraceuticals.

With advancements in veterinary care and the growing recognition of pets as integral member of the family, the lifespans of dogs and cats have significantly increased, leading to a higher prevalence of age-related conditions, including cognitive dysfunction syndrome (CDS). CDS adversely impacts pets' quality of life and presents emotional and practical challenges for owners. Given its similarities to Alzheimer's disease in humans, CDS has gained attention as a target for nutrition-based interventions aimed at preserving cognitive function. This systematic review evaluates the efficacy of enriched diets and nutraceuticals in improving cognition in aging companion animals. A literature search was conducted using PubMed, CAB Abstracts, Web of Science, and Dimensions to identify clinical trials published in English that investigated the effects of enriched diets or nutraceuticals on cognitive functions in aged cats or dogs. Study quality was assessed using a modified CAMARADES checklist. A total of 30 studies (27 canine and 2 feline trials) published between 2002 and 2023 were reviewed. Studies on enriched diets generally demonstrated higher methodological quality compared to those on supplements. Omega-3 fatty acids showed cognitive benefits in aging pets, especially at higher doses, while antioxidants from plant extracts and products and vitamins E and C alone were less effective but remain essential for stabilizing omega-3 fatty acids. Other supplements, including S-adenosyl methionine, medium-chain triglycerides, homotaurine, and apoaequorin, also showed promise. However, future studies must standardize protocols, include robust control groups, and utilize both objective tasks and subjective questionnaires to strengthen conclusions.

Challenges and insights of transferring animal maze studies principles to human spatial learning research

Maze tasks, originally developed in animal research, have become a popular method for studying human cognition, particularly with the advent of virtual reality. However, these experiments frequently rely on simplified environments and tasks, which may not accurately reflect the complexity of real-world situations. Our pilot study aims to transfer a multi-alternative maze with a complex task structure, previously demonstrated to be useful in studying animal cognition, to studying human spatial cognition. The challenges to be resolved at this stage included developing a virtual maze and selecting an appropriate instruction that will elicit processes similar to those observed in animal models. A virtual maze was developed, and two types of instructions were provided to the participants: (1) to collect coins; (2) to interact with the maze in order to draw its structure after the game. The results indicate that a more structured instruction with a clear attainable goal (“collect”) prompted more in-depth exploration and engagement with the key elements of the maze, eliciting processes similar to those of animals. While the maze demonstrates promise as a tool for comparative studies, it also has the potential to uncover different aspects of human cognition.

Beyond the null: Recognizing and reporting true negative findings.

Beyond the null: Recognizing and reporting true negative findings.

What an Animal Cognition Researcher Who Did Not Think They Studied Occasion Setting Might Take Home From This Conversation

What an Animal Cognition Researcher Who Did Not Think They Studied Occasion Setting Might Take Home From This Conversation

Occasion Setting in Animal Cognition Research: Some Unaddressed Issues

Occasion Setting in Animal Cognition Research: Some Unaddressed Issues

Cultural Frontiers in Research on Non-Human Primates

This literature review explores recent research on primate communication, social learning, and the presence of social norms in non-human animals. It highlights significant findings, including group-specific communication patterns, the adaptive benefits of social learning through imitation and rapid behavioural mimicry, and the existence of socially maintained behaviours akin to human norms. These studies collectively illustrate the complex social lives of primates and offer valuable insights into the evolutionary origins of human culture and social norms. The review also delves into the philosophical implications of these findings, challenging traditional views of human uniqueness and expanding our understanding of animal behaviour and cognition.

Monkeys engage in visual simulation to solve complex problems.

Monkeys engage in visual simulation to solve complex problems.

Processing Fluency and Predictive Processing: How the Predictive Mind Becomes Aware of its Cognitive Limitations

AbstractPredictive processing is an influential theoretical framework for understanding human and animal cognition. In the context of predictive processing, learning is often reduced to optimizing the parameters of a generative model with a predefined structure. This is known as Bayesian parameter learning. However, to provide a comprehensive account of learning, one must also explain how the brain learns the structure of its generative model. This second kind of learning is known as structure learning. Structure learning would involve true structural changes in generative models. The purpose of the current paper is to describe the processes involved upstream of these structural changes. To do this, we first highlight the remarkable compatibility between predictive processing and the processing fluency theory. More precisely, we argue that predictive processing is able to account for all the main theoretical constructs associated with the notion of processing fluency (i.e., the fluency heuristic, naïve theory, the discrepancy‐attribution hypothesis, absolute fluency, expected fluency, and relative fluency). We then use this predictive processing account of processing fluency to show how the brain could infer whether it needs a structural change for learning the causal regularities at play in the environment. Finally, we speculate on how this inference might indirectly trigger structural changes when necessary.

Death-feigning, animal concepts, and the use of empirical case studies in animal cognition

Death-feigning, animal concepts, and the use of empirical case studies in animal cognition

MeHA: A Computational Framework in Revealing the Genetic Basis of Animal Mental Health Traits Under an Intensive Farming System-A Case Study in Pigs.

Intensively farmed animals such as pigs inevitably experience a certain degree of psychological stress, which leads to a reduction in production performance. Mental health traits are currently difficult to measure, resulting in a gap in understanding their genetic basis. To address this challenge, we propose a computational framework called mental health of animals (MeHA), capable of revealing genes related to animal mental health traits. Using MeHA, we identified 109 candidate genes associated with pig mental health and discovered their intricate connections with critical functions, such as memory, cognition, and neural development, which are essential components of mental health and cognitive performance. Importantly, our findings provide evidence of the potential impact of these genes on economically important traits, including meat quality and piglet survival. This research underscores the importance of genetic studies in enhancing our understanding of animal behavior and cognition, as well as promoting agricultural practices. By applying our approach to study the genetic basis of mental health in pigs as a case, we confirmed that our framework is an effective way to reveal genetic factors affecting animal mental health traits, which contributes to animal welfare and has potential implications for understanding human mental disorders.