Comparative Cognition Research Research Articles

Understanding the limits to animal cognition

The thriving field of comparative cognition examines the behaviour of diverse animals in cognitive terms. Comparative cognition research has primarily focused on the abilities of animals - what tasks they can do - rather than on the limits of their cognition - tasks that exceed an animal's cognitive abilities. We propose that understanding and identifying cognitive limits is as important as demonstrating the capacities of animal minds. Here, we identify challenges that have deterred the study of cognitive limits related to epistemic, practical and publication problems. The epistemic problem is concerned with how we can confidently infer a cognitive limit from null or negative results. The practical problem is how can we be certain our research has identified a cognitive limit rather than failures in tasks due to methodological or experimental design issues. The publication problem outlines the publication bias toward positive and exciting results over negative or null results in animal cognition. We propose solutions to these three challenges and examples of how to conduct research to confidently identify and confirm cognitive limits in animals. We believe a refocus on the cognitive limits of animals is the next step in the field of comparative cognition. Knowing the limits to the intelligence of different animals will aid us in appreciating the diversity of animal intelligence, and will resolve outstanding questions of how cognition evolves.

The Benefits of Increasing Livestock Species in Comparative Cognition Research

The Benefits of Increasing Livestock Species in Comparative Cognition Research

Taking Welfare into Account in Comparative Cognition Research

Taking Welfare into Account in Comparative Cognition Research

Advancing Our Understanding of Cognition by Including
 Amphibians and Reptiles in Comparative Cognition Research

Advancing Our Understanding of Cognition by Including
 Amphibians and Reptiles in Comparative Cognition Research

Comparative Cognition Research: Where Do We Go from Here?

Comparative Cognition Research: Where Do We Go from Here?

Dynamic object–fruit combinations by introduced Tanimbar corellas (Cacatua goffiniana) in Singapore

Abstract Tanimbar corellas, an important model in comparative cognition research, are endemic to the Tanimbar Islands, Indonesia, but were also introduced to several other locations with a tropical climate. Introduced psittacines offer valuable opportunities to test hypotheses at large temporal and spatial scales, such as geographic distribution of behaviours. Here, we report two opportunistic observations of Tanimbar corellas combining small wooden fragments with two types of tropical fruit (Ketapang and Pong-pong) in Singapore. The observations were recorded and uploaded to YouTube by a local bird-watcher. We analyse the behavioural similarities and differences between object combinations with the Pong-pong fruit in Singapore and extractive tool use on the Wawai fruit in Indonesia. Repeated insertions of the wooden fragment into the fruit and visible ingestion suggest that the combinatory behaviours were most likely related to foraging. This report provides first insights into the presence of advanced technical abilities in geographically separated Tanimbar corellas.

The use of gaze to study cognition: limitations, solutions, and applications to animal welfare.

The study of gaze responses, typically using looking time paradigms, has become a popular approach to improving our understanding of cognitive processes in non-verbal individuals. Our interpretation of data derived from these paradigms, however, is constrained by how we conceptually and methodologically approach these problems. In this perspective paper, we outline the application of gaze studies in comparative cognitive and behavioral research and highlight current limitations in the interpretation of commonly used paradigms. Further, we propose potential solutions, including improvements to current experimental approaches, as well as broad-scale benefits of technology and collaboration. Finally, we outline the potential benefits of studying gaze responses from an animal welfare perspective. We advocate the implementation of these proposals across the field of animal behavior and cognition to aid experimental validity, and further advance our knowledge on a variety of cognitive processes and welfare outcomes.

Comparative Cognition Research Demonstrates the Similarity between Humans and Other Animals.

The field of comparative cognition represents the interface between the cognitive behavior of humans and other animals. In some cases, research demonstrates that other animals are capable of showing similar cognitive processes. In other cases, when animals show behavior thought to be culturally determined in humans, it suggests that simpler processes may be involved. This review examines research primarily with pigeons (out of convenience because of their visual ability). I start with the concept of sameness and follow with the concept of stimulus equivalence, the building blocks of human language. This is followed by research on directed forgetting, the cognitive ability to maintain or forget information. A hallmark of cognition is transitive inference performance (if A < B, and B < C, the understanding that A < C), but the variety of species that show this ability suggests that there may be simpler accounts of this behavior. Similarly, experiments that demonstrate a form of cognitive dissonance in animals suggest that dissonance may not be necessary to explain this biased behavior. Furthermore, examples of sunk cost in pigeons suggests that the human need to continue working on a failing project may also have a biological basis. Finally, pigeons show a preference for a suboptimal choice that is similar to unskilled human gambling, a finding that may clarify why humans are so prone to engage in this typically losing activity.

Investigating responses to object-labels in the domestic dog (Canis familiaris)

Since the dawn of comparative cognitive research, dogs were suspected to possess some capacity for responding to human spoken language. Neuroimaging studies have supported the existence of relevant mechanisms, but convincing behavioral performance is rare, with only few exceptional dogs worldwide demonstrating a lexicon of object-labels they respond to. In the present study we aimed to investigate if and how a capacity for processing verbal stimuli is expressed in dogs (N = 20), whose alleged knowledge of verbal labels is only backed-up by owner reports taken at face value, and concerning only a few words (on average 5). Dogs were tested in a two-choice paradigm with familiar objects. The experiment was divided into a cue-control condition (objects visible to the owner vs. shielded by a panel, thereby controlling the owner’s ability to emit cues to the dog) and a response type condition (fetching vs. looking). Above chance performance in fetching and looking at the named object emerged on the level of the sample as a whole. Only one individual performed reliably above chance, but the group-level effect did not depend on this data point. The presence of the panel also had no influence, which supports that performance was not driven by non-verbal cues from the owners. The group-level effect suggests that in typical dogs object-label learning is an instable process, either due to the animals primarily engaging in contextual learning or possibly analogous to the early stages of implicit, statistical learning of words in humans and opposed to the rapid mapping reported in exceptional dogs with larger passive vocabulary.

Interaction and ostension: the myth of 4th-order intentionality.

Research in comparative cognition on allegedly uniquely human capacities considers the identification of these human capacities in other species as one of their main points of inquiry. Capacities are applied in their theoretical descriptions to promising empirical data. The conclusion then often is that even though, on a behavioural level, the human and nonhuman cases appear related, on a cognitive level there is no relation whatsoever because the underlying cognitive states diverge in quality. This result seems dissatisfying for two reasons: (1) there is ample empirical evidence that suggests the presence of the capacities in other species, and (2) the claim that the underlying states diverge often hinges on the reference to the theoretical definitions of these capacities only. This opinion piece focuses on the capacity of ostensive intentional communication to demonstrate that the original theoretical analyses often are not befitting a comparative endeavour and should therefore not be used as pivotal reference within comparative research. An outlook will be provided on more promising approaches to identifying ostensive communication, namely an interactive approach that will allow for ostension to not be perceived as a one-turn signalling behaviour, but as interactive, with the possibility of being established in a trial-and-error manner. This article is part of the theme issue 'Revisiting the human 'interaction engine': comparative approaches to social action coordination'.

Great Tits Chosen for Greatness Makes Them Representative: A commentary on Farrar et al.'s "Replications, Comparisons, Sampling and the Problem of Representativeness in Animal Cognition Research"

Studies of animal cognition struggle frequently with the question of how representative results from small samples are for a species. A recent article by Farrar et al. (2021), in this journal, highlights some of the major problems and suggests some solutions to these with cautionary examples drawn from the animal cognition literature. One such example comes from a study of inhibitory control in the great tit, Parus major, by the authors of this commentary. Although we recognize, and agree, that there are issues regarding representativeness in studies of animal cognition, we disagree with the use of our inhibitory control study as a cautionary example. Here, we explain why we think that our study is representative of Great tit inhibitory control. In fact, some of our arguments as to why our study is representative are in agreement with suggestions by Farrar et al (2021), e.g., comparing individuals with different levels of previous experiences in the cognitive paradigm under investigation. Moreover, we also add to Farrar et al.’s (2021) conclusion on how to approach studies with ambiguous representativeness by highlighting the importance of recognizing and discussing methodological differences in studies of cognitive ability. In summary, we do not argue against the valid points laid out by Farrar et al (2021), but discuss important nuances of the representativeness issue to also consider and, most importantly, add an additional point of scrutiny to account for in comparative animal cognition research.

Executive Functions in Birds

Executive functions comprise of top-down cognitive processes that exert control over information processing, from acquiring information to issuing a behavioral response. These cognitive processes of inhibition, working memory, and cognitive flexibility underpin complex cognitive skills, such as episodic memory and planning, which have been repeatedly investigated in several bird species in recent decades. Until recently, avian executive functions were studied in relatively few bird species but have gained traction in comparative cognitive research following MacLean and colleagues’ large-scale study from 2014. Therefore, in this review paper, the relevant previous findings are collected and organized to facilitate further investigations of these core cognitive processes in birds. This review can assist in integrating findings from avian and mammalian cognitive research and further the current understanding of executive functions’ significance and evolution.

ManyBirds: A multi-site collaborative Open Science approach to avian cognition and behavior research

Comparative cognitive and behavior research aims to investigate cognitive evolution by comparing performance in different species to understand how these abilities have evolved. Ideally, this requires large and diverse samples; however, these can be difficult to obtain by single labs or institutions, leading to potential reproducibility and generalization issues with small, less representative samples. To help mitigate these issues, we are establishing a multi-site collaborative Open Science approach called ManyBirds, with the aim of providing new insight into the evolution of avian cognition and behavior through large-scale comparative studies, following the lead of exemplary ManyPrimates, ManyBabies and ManyDogs projects. Here, we outline a) the replicability crisis and why we should study birds, including the origin of modern birds, avian brains and convergent evolution of cognition; b) the current state of the avian cognition field, including a ‘snapshot’ review; c) the ManyBirds project, with plans, infrastructure, limitations, implications and future directions. In sharing this process, we hope that this may be useful for other researchers in devising similar projects in other taxa, like non-avian reptiles or mammals, and to encourage further collaborations with ManyBirds and related ManyX projects. Ultimately, we hope to promote collaboration between ManyX projects to allow for wider investigation of the evolution of cognition across all animals, including potentially humans.

Little evidence that Eurasian jays protect their caches by responding to cues about a conspecific's desire and visual perspective.

Eurasian jays have been reported to protect their caches by responding to cues about either the visual perspective or current desire of an observing conspecific, similarly to other corvids. Here, we used established paradigms to test whether these birds can - like humans - integrate multiple cues about different mental states and perform an optimal response accordingly. Across five experiments, which also include replications of previous work, we found little evidence that our jays adjusted their caching behaviour in line with the visual perspective and current desire of another agent, neither by integrating these social cues nor by responding to only one type of cue independently. These results raise questions about the reliability of the previously reported effects and highlight several key issues affecting reliability in comparative cognition research.

Intra-specific differences in cognition: bumblebee queens learn better than workers.

Species' cognitive traits are shaped by their ecology, and even within a species, cognition can reflect the behavioural requirements of individuals with different roles. Social insects have a number of discrete roles (castes) within a colony and thus offer a useful system to determine how ecological requirements shape cognition. Bumblebee queens are a critical point in the lifecycle of their colony, since its future success is reliant on a single individual's ability to learn about floral stimuli while finding a suitable nest site; thus, one might expect particularly adept learning capabilities at this stage. I compared wild Bombus vosnesenskii queens and workers on their ability to learn a colour association and found that queens performed better than workers. In addition, queens of another species, B. insularis, a cuckoo species with a different lifecycle but similar requirements at this stage, performed equally well as the non-parasitic queens. To control for differences in foraging experience, I then repeated this comparison with laboratory-based B. impatiens and found that unmated queens performed better than workers. These results add to the body of work on how ecology shapes cognition and opens the door to further research in comparative cognition using wild bees.

How intelligent is a cephalopod? Lessons from comparative cognition.

The soft-bodied cephalopods including octopus, cuttlefish, and squid are broadly considered to be the most cognitively advanced group of invertebrates. Previous research has demonstrated that these large-brained molluscs possess a suite of cognitive attributes that are comparable to those found in some vertebrates, including highly developed perception, learning, and memory abilities. Cephalopods are also renowned for performing sophisticated feats of flexible behaviour, which have led to claims of complex cognition such as causal reasoning, future planning, and mental attribution. Hypotheses to explain why complex cognition might have emerged in cephalopods suggest that a combination of predation, foraging, and competitive pressures are likely to have driven cognitive complexity in this group of animals. Currently, it is difficult to gauge the extent to which cephalopod behaviours are underpinned by complex cognition because many of the recent claims are largely based on anecdotal evidence. In this review, we provide a general overview of cephalopod cognition with a particular focus on the cognitive attributes that are thought to be prerequisites for more complex cognitive abilities. We then discuss different types of behavioural flexibility exhibited by cephalopods and, using examples from other taxa, highlight that behavioural flexibility could be explained by putatively simpler mechanisms. Consequently, behavioural flexibility should not be used as evidence of complex cognition. Fortunately, the field of comparative cognition centres on designing methods to pinpoint the underlying mechanisms that drive behaviours. To illustrate the utility of the methods developed in comparative cognition research, we provide a series of experimental designs aimed at distinguishing between complex cognition and simpler alternative explanations. Finally, we discuss the advantages of using cephalopods to develop a more comprehensive reconstruction of cognitive evolution.

Unifying psychological and biological approaches to understanding animal cognition.

This special issue has two main aims. The first aim is to broaden the scope of the Canadian Journal of Experimental Psychology. This aim is motivated by the simple fact that the journal's mandate includes comparative psychology, but many of the articles published in the journal are currently, and have been for some time, mainly human cognitive in nature. The second aim of this issue is one that we take very seriously, and that is to promote not only comparative cognition and cognitive ecology research but research from a diverse group of scientists. Although the global diversity in this special issue is not exhaustive, there is work highlighted from scientists at institutions in Canada, Germany, Italy, the Netherlands, Spain, the United Kingdom, and the United States. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Mental Structures as Biosemiotic Constraints on the Functions of Non-human (Neuro)Cognitive Systems

This paper approaches the question of how to describe the higher-level internal structures and representations of cognitive systems across various kinds of nonhuman (neuro)cognitive systems. While much research in cognitive (neuro)science and comparative cognition is dedicated to the exploration of the (neuro)cognitive mechanisms and processes with a focus on brain-behavior relations across different non-human species, not much has been done to connect (neuro)cognitive mechanisms and processes and the associated behaviors to plausible higher-level structures and representations of distinct kinds of cognitive systems in non-humans. Although the study of (neuro)cognitive mechanisms and processes can certainly be revealing, (neuro)cognitive mechanisms and processes are underspecified with respect to internal structures and representations of non-human cognitive systems because multiple such mechanisms can target, or be mapped onto, the same internal structure or vice versa. This paper outlines a biosemiotic approach to this linking problem in order to bridge the gap between functions of (neuro)cognitive systems in different species and the higher-level cognitive structures and representations. It is contended that the higher-level internal structures and representations of various cognitive systems are biosemiotic constraints on the (biological) functions of (neuro)cognitive systems that serve to restrict the range of functions (neuro)cognitive systems have or are selected for. This turns out to have implications for issues on the convergent evolution of cognitive traits.

Prospective information-seeking in human children (Homo sapiens): When to seek and what to seek.

Human adults often envisage future events and prepare items or information in advance. Studies have shown that young children can also prepare items for upcoming events, but little is known about their ability to prepare information for such events. Here, we used nonverbal measures, which are widely used in comparative cognitive research, to ask whether children seek information for their future knowledge states or events. In Experiment 1, 4- and 5-year-olds had to find a sticker located under an opaque or transparent cup. The children could observe by peeking while an experimenter placed the sticker for the trial. We found that 5-year-olds peeked for longer in the opaque than the transparent condition but 4-year-olds did not. In Experiment 2, 5- and 6-year-olds had to find stickers in 2 rooms; in 1 room, an actor hid a sticker under 1 of 5 opaque cups, whereas in the other room, another actor placed a sticker under 1 of 5 transparent cups. Children could observe what the actors were doing via a monitor and then choose a room in which to search. Children of both age-groups watched events in the opaque-cup room longer than the transparent-cup room in the first trial. These results suggest that at least 5-year-olds can collect appropriate information for a future task. Our procedure should be easily adaptable for a range of nonhuman species. Studies using this procedure might reveal the phylogenetic distribution of this metacognitive ability. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Bumblebees Use Sequential Scanning of Countable Items in Visual Patterns to Solve Numerosity Tasks.

Most research in comparative cognition focuses on measuring if animals manage certain tasks; fewer studies explore how animals might solve them. We investigated bumblebees’ scanning strategies in a numerosity task, distinguishing patterns with two items from four and one from three, and subsequently transferring numerical information to novel numbers, shapes, and colors. Video analyses of flight paths indicate that bees do not determine the number of items by using a rapid assessment of number (as mammals do in “subitizing”); instead, they rely on sequential enumeration even when items are presented simultaneously and in small quantities. This process, equivalent to the motor tagging (“pointing”) found for large number tasks in some primates, results in longer scanning times for patterns containing larger numbers of items. Bees used a highly accurate working memory, remembering which items have already been scanned, resulting in fewer than 1% of re-inspections of items before making a decision. Our results indicate that the small brain of bees, with less parallel processing capacity than mammals, might constrain them to use sequential pattern evaluation even for low quantities.