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Cognitive tests sensitive to the integrity of the medial temporal lobe (MTL), such as mnemonic discrimination of perceptually similar stimuli, may be useful early markers of risk for cognitive decline in older populations. Perceptual discrimination of stimuli with overlapping features also relies on MTL but remains relatively unexplored in this context. We assessed mnemonic discrimination in two test formats (Forced Choice, Yes/No) and perceptual discrimination of objects and scenes in 111 community-dwelling older adults at different risk status for cognitive impairment based on neuropsychological screening. We also investigated associations between performance and MTL sub-region volume and thickness. The at-risk group exhibited reduced entorhinal thickness and impaired perceptual and mnemonic discrimination. Perceptual discrimination impairment partially explained group differences in mnemonic discrimination and correlated with entorhinal thickness. Executive dysfunction accounted for Yes/No deficits in at-risk adults, demonstrating the importance of test format for the interpretation of memory decline. These results suggest that perceptual discrimination tasks may be useful tools for detecting incipient cognitive impairment related to reduced MTL integrity in nonclinical populations. more...

Large-brained birds, such as corvids and parrots, tend to fail tests for self-recognition (mirror self-recognition [MSR]), but the limited positive evidence for MSR in these species has been questioned due to methodological limitations. In the present study, we aimed to investigate MSR in ravens by performing three mirror tests: a mirror exposure test, a mirror preference test, and a mark test. Across all three tests, the ravens' behavior was not consistent with MSR. Three out of six ravens infrequently interacted with the mirror and the nonmirror surfaces. Two birds explored the mirror and occasionally displayed contingent behaviors. Finally, the ravens made very few social displays toward the mirror, suggesting that at this stage they did not treat their reflection as a conspecific. These findings, along with the current evidence available, raise further questions on the validity of relying on one test to establish self-recognition and call for the development of methods beyond mirror tests to explore self-recognition in nonhuman animals. (PsycInfo Database Record (c) 2022 APA, all rights reserved). more...

Funder: European Commission; FundRef: http://dx.doi.org/10.13039/501100000780; Grant(s): Marie Skłodowska-Curie Fellowship MENTALIZINGORIGINS Grant reference: 752373, Funder: FP7 Ideas: European Research Council; Grant(s): ERC Grant Agreement N 3399933, 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. more...

Animal cognition research aims to understand animal minds by using a diverse range of methods across an equally diverse range of species. Throughout its history, the field has sought to mitigate various biases that occur when studying animal minds, from experimenter effects to anthropomorphism. Recently, there has also been a focus on how common scientific practices might affect the reliability and validity of published research. Usually, these issues are discussed in the literature by a small group of scholars with a specific interest in the topics. This study aimed to survey a wider range of animal cognition researchers to ask about their attitudes towards classic and contemporary issues facing the field. Two-hundred and ten active animal cognition researchers completed our survey, and provided answers on questions relating to bias, replicability, statistics, publication, and belief in animal cognition. Collectively, researchers were wary of bias in the research field as a whole, but less so in their own work. Despite sometimes (39.7% of responses) or often (38.8% of responses) hoping for one result over another, researchers reported that they could often (45.8% of responses) or always (38.4% of responses) detach from any biases to perform objectively fair tests of animal cognition. Over 70% of researchers endorsed Morgan’s canon as a useful principle but many caveated this in their free-text responses, and researchers self-reported that a median of 80% of their studies had been published. Their free-text responses suggested a stronger publication bias against negative and inconclusive results, and results that questioned “preferred” theories. Researchers rarely reported having performed questionable research practices themselves — however they thought that other researchers sometimes (52.7% of responses) or often (27.9% of responses) perform them. Researchers near unanimously agreed that replication studies are important but too infrequently performed in animal cognition research, and 44.7% of researchers agreed that their own area (44.7% of responses), or other areas (73.0% of responses) of research could experience a ‘replication crisis’ if replication studies were performed. Consistently, participants’ free-text responses provided a nuanced picture of the challenges animal cognition research faces, and highlighted many possible improvements. Overall, these data provide a picture of active researchers’ beliefs about the animal cognition research processes that can be used to inform debates on where and how the field can improve. more...

Corvids appear to be capable of adjusting their behaviour according to another’s perspective, knowledge and desire. For example, Eurasian jays have been found to employ a variety of cache protection strategies to minimise cache loss by responding to cues about the visual perspective or current desire of an observing conspecific. However, it is not known whether these jays (or any other corvid) can integrate multiple cues about different mental states and perform the optimal response accordingly. Across five experiments, we found little evidence that our Eurasian jays responded to either the visual perspective or current desire of another agent. In Experiments 1 and 2 we investigated whether Eurasian jays can limit the risk of cache loss by responding simultaneously to cues about the desire and perspective of a potential conspecific pilferer. Building on established paradigms, we used opaque and clear barriers to manipulate the observer’s visual access to cache locations, and specific satiety to manipulate the observer’s desire towards different types of food. Across both experiments the jays’ caching pattern provided no evidence that they could integrate information about the observer’s desire and perspective. Moreover, the results were also inconsistent with the previously reported effects that jays protect their caches by responding to either the visual access or specific satiety of the observer independently. To gain further insight into these unexpected results, we conducted three more experiments. In Experiments 3 and 4, we attempted to replicate the previous finding that Eurasian jays prefer to cache behind an opaque barrier over a clear barrier when observed by a conspecific than when caching in private. In Experiment 5, we further investigated the previous finding that jays preferentially cache a type of food that had been eaten to satiety by a conspecific over a food that had not been eaten by the conspecific. Experiments 3, 4 and 5 found no significant effects in the direction of the previously reported effects, questioning their robustness. We conclude by discussing the implications of our study for the field of corvid cognition and highlight several key issues that affect the reliability of comparative cognition research. more...

A "STRANGE" framework has been proposed to mitigate the effects of sampling biases in animal experiments (WebsterRutz, Nature, 582, 337-340, 2020). While sampling biases are likely a major cause of poor replicability and generalizability in animal behavior research, a more comprehensive and cautious approach is needed to effectively guide decision-making in animal research. more...

Previous research reported that corvids preferentially cache food in a location where no food will be available or cache more of a specific food in a location where this food will not be available. Here, we consider possible explanations for these prospective caching behaviours and directly compare two competing hypotheses. The Compensatory Caching Hypothesis suggests that birds learn to cache more of a particular food in places where that food was less frequently available in the past. In contrast, the Future Planning Hypothesis suggests that birds recall what-when-where features of specific past events to predict the future availability of food. We designed a protocol in which the two hypotheses predict different caching patterns across different caching locations such that the two explanations can be disambiguated. We formalised the hypotheses in a Bayesian model comparison and tested this protocol in two experiments with one of the previously tested species, namely Eurasian jays. Consistently across the two experiments, the observed caching pattern did not support either hypothesis; rather it was best explained by a uniform distribution of caches over the different caching locations. Future research is needed to gain more insight into the cognitive mechanism underpinning corvids’ caching for the future. more...

Twenty years after Povinelli’s “Folk Physics for Apes”, this paper assesses how researchers have made claims about animal physical cognition, and the statistical inferences that have been used to support them. These data are relevant in light of the current replicability issues facing science. We surveyed 116 published experiments from 63 papers on physical cognition, which included data from 43 different species of animals. Across these experiments most sample sizes were small, with often fewer than 10 animals being tested. However, in contrast to related psychological disciplines, we found that only 62% of our sample of physical cognition research made positive claims. This suggests that animal physical cognition does not have a strong publication bias towards positive results. Furthermore, we found evidence that researchers are making many true statistical inferences at the individual level, i.e. whether individual animals pass certain tests of physical cognition or not. In contrast, the strength of evidence of statistical effects at the group level was weaker and consistent with many effect sizes being overestimated. Overall, our analysis provides a cautiously optimistic analysis of reliability and bias in animal physical cognition research, however it is nevertheless likely that a non-negligible proportion of results will be difficult to replicate. more...

Fayet, Hansen and Biro (1) provide two observations of Atlantic puffins, Fratercula arctica performing self-directed actions while holding a stick in their beaks. The authors interpret this as evidence of tool use as they suggest that the stick was manipulated towards the birds’ plumage with the specific goal of scratching. While these are interesting observations, the authors do not address a simple and likely explanation of the self-directed actions that does not constitute tool use; that the observations occurred by chance. As such, their conclusions about tool use and cognition in seabirds are premature. more...

A “STRANGE” framework has been proposed to mitigate the effects of sampling biases in animal experiments (Webster & Rutz, Nature, 582, 337– 340, 2020). While sampling biases are likely a major cause of poor replicability and generalizability in animal behavior research, a more comprehensive and cautious approach is needed to effectively guide decision- making in animal research. more...

A prominent vein of comparative cognition research asks which cognitive abilities may be ascribed to different species. Here, we argue that the current structure of comparative cognition makes it near impossible to evaluate the accuracy of many of the claims produced by the field’s empirical research. We base this argument on six observations: i) the field is biased towards confirming more exceptional abilities in animals, ii) a likely high rate of false positive discovery, iii) the persistence of the bias towards more exceptional abilities, even in the presence of strong methodological criticism, iv) the absence of a formal method to assess evidence of absence of a cognitive ability, v) the ambiguity in definitions used to make claims, and vi) the small size of the research field. We then highlight how the widespread methodological and conceptual criticism in the comparative cognition literature does not facilitate scientific progress, rather it can impede it by creating an illusion of scientific rigour. Finally, we call for a reform of our research field that draws on recent developments in related fields and the Open Science movement. more...

When given privileged information of an object’s true location, adults often overestimate the likelihood that a protagonist holding a false belief will search in the correct location for that object. This type of egocentric bias is often labelled the ‘curse of knowledge’. Interestingly, the magnitude of this bias may be modulated by the social distance between the perspective taker and target. However, this social distance effect has yet to be fully demonstrated when adults reason about false beliefs. Using a continuous false belief task, we investigated i) whether adults were biased by their own knowledge when reasoning about another’s false belief, ii) whether the magnitude of this egocentric bias was modulated by social distance, and iii) whether this social distance effect extended to a heterospecific out-group, namely a dog. To test these hypotheses we conducted three experiments. In Experiment 1 (N = 283), we used an established continuous false belief task, in Experiment 2 (N = 281) we modified this task, and Experiment 3 (N = 744) was a direct replication of Experiment 2. Across these experiments, the curse of knowledge effect was reliably replicated when adults mentalised about an in-group protagonist, and replicated in two of the three studies (Experiments 1 and 3) when adults mentalised about out-group protagonists. In an internal-meta analysis, the curse of knowledge effect was present across all conditions, and there was no effect of social distance. Hence, overall these data are not consistent with the hypothesis that social distance modulates adults’ egocentric biases when reasoning about false beliefs. The finding that egocentric biases of a similar magnitude were observed when adults mentalised about an in-group protagonist and a dog suggests that interpersonal dissimilarity is not in itself sufficient to reduce egocentric bias when reasoning about false beliefs. more...