Corvid caching: Insights from a cognitive model

Caching and recovery of food by corvids is well-studied, but some ambiguous results remain. To help clarify these, we built a computational cognitive model. It is inspired by similar models built for humans, and it assumes that memory strength depends on frequency and recency of use. We compared our model's behavior to that of real birds in previously published experiments. Our model successfully replicated the outcomes of two experiments on recovery behavior and two experiments on cache site choice. Our "virtual birds" reproduced declines in recovery accuracy across sessions, revisits to previously emptied cache sites, a lack of correlation between caching and recovery order, and a preference for caching in safe locations. The model also produced two new explanations. First, that Clark's nutcrackers may become less accurate as recovery progresses not because of differential memory for different cache sites, as was once assumed, but because of chance effects. And second, that Western scrub jays may choose their cache sites not on the basis of negative recovery experiences only, as was previously thought, but on the basis of positive recovery experiences instead. Alternatively, both "punishment" and "reward" may be playing a role. We conclude with a set of new insights, a testable prediction, and directions for future work.     

Young‐age gender differences in mathematics mediated by independent control or uncontrollability

We studied whether the origins of math anxiety can be related to a biologically supported framework of stress induction: (un)controllability perception, here indicated by self‐reported independent efforts in mathematics. Math anxiety was tested in 182 children (8‐ to 11‐year‐olds). Latent factor modeling was used to test hypotheses on plausible causal processes and mediations within competing models in quasi‐experimental contrasts. Uncontrollability perception in mathematics, or (in)dependence of efforts, best fit the data as an antecedent of math anxiety. In addition, the relationship of math anxiety with gender was fully mediated by adaptive perception of control (i.e. controllability). That is, young boys differ from girls in terms of their experience of control in mathematics learning. These differences influence math anxiety. Our findings are consistent with recent suggestions in clinical literature according to which uncontrollability makes women more susceptible to fear and anxiety disorders. A video abstract of this article can be viewed at http://www.youtube.com/watch?v=I4b_47Y-e_U     

From Negative Emotionality to Aggressive Behavior: Maternal and Paternal Parenting Stress as Intervening Factors

Research on Child and Adolescent Psychopathology - Child temperament plays a key role in the development of psychopathology, notably through transactions with the family environment. In particular,...     

Digital embryos: a novel technical approach to investigate perceptual categorization in pigeons (Columba livia) using machine learning

Animal Cognition - Pigeons are classic model animals to study perceptual category learning. To achieve a deeper understanding of the cognitive mechanisms of categorization, a careful consideration...     

Impact of Well-being Interventions for Siblings of Children and Young People with a Chronic Physical or Mental Health Condition: A Systematic Review and Meta-Analysis

Siblings of children and young people with a chronic illness are at increased risk of poor psychological functioning. A number of studies have attempted to implement and evaluate interventions targeting the psychological well-being of this at-risk group. This systematic review summarises the evidence regarding psychological functioning of siblings following an intervention targeting their well-being. The meta-analysis considered behaviour and knowledge, two of the most frequently studied outcomes. The following databases were used: PsycINFO, EMBASE, CINAHL, PubMed, Scopus and Web of Science. Seventeen studies were eligible to be included in the systematic review and eight in the meta-analysis. Results from the systematic review reflected the inconsistency of intervention evaluations in this area with a high level of heterogeneity and a total of 23 outcomes considered across the 17 included studies. The meta-analysis estimated effect sizes using a standardised mean difference (SMD) approach. Pre-post analysis suggested significant improvement in behavioural outcomes and knowledge of their sibling’s health conditions with a SMD of ? 0.44 [95% CI (? 0.6, ? 0.29); p = 0.000] and 0.69 [(95% CI = 0.42, 0.96); p = 0.000], respectively. The SMD was not significant for behavioural outcomes when considering treatment–control studies. In conclusion, the findings suggest interventions for well-being have a positive effect on the psychological functioning of siblings of children and young people with a chronic illness, but their specificity needs to be established. There is a need for further, more methodologically robust research in this area.     

Young macaques (<Emphasis Type="Italic">Macaca fascicularis</Emphasis>) preferentially bias attention towards closer,older, and better tool users

Examining how animals direct social learning during skill acquisition under natural conditions, generates data for examining hypotheses regarding how transmission biases influence cultural change in animal populations. We studied a population of macaques on Koram Island, Thailand, and examined model-based biases during interactions by unskilled individuals with tool-using group members. We first compared the prevalence of interactions (watching, obtaining food, object exploration) and proximity to tool users during interactions, in developing individuals (infants, juveniles) versus mature non-learners (adolescents, adults), to provide evidence that developing individuals are actively seeking information about tool use from social partners. All infants and juveniles, but only 49% of mature individuals carried out interacted with tool users. Macaques predominantly obtained food by scrounging or stealing, suggesting maximizing scrounging opportunities motivates interactions with tool users. However, while interactions by adults was limited to obtaining food, young macaques and particularly infants also watched tool users and explored objects, indicating additional interest in tool use itself. We then ran matrix correlations to identify interaction biases, and what attributes of tool users influenced these. Biases correlated with social affiliation, but macaques also preferentially targeted tool users that potentially increase scrounging and learning opportunities. Results suggest that social structure may constrain social learning, but the motivation to bias interactions towards tool users to maximize feeding opportunities may also socially modulate learning by facilitating close proximity to better tool users, and further interest in tool-use actions and materials, especially during development.     

The emotional male victim: Effects of presentation mode on judged credibility

The emotional victim effect (EVE, i.e., that the emotionality of a victim's demeanor affects perceived credibility) is a robust research finding for female victims of rape but much less explored for other types of victims and crimes. In this article, we investigate the EVE with a male assault complainant. In addition, we vary the presentation mode via which the complainant is shown to the assessors. A sample of law students (N = 81) participated in an experiment where they viewed and assessed credibility of a male complainant who appeared either live or on video. The complainant behaved either in an emotional or a neutral manner. Result showed that the presentation mode but not the EVE affected the assessors' credibility assessments: The complainant was perceived as more truthful when communicating live, as opposed to via video. Practical implications, as well as the generality of the EVE, are discussed.     

Auditory Pareidolia: Effects of Contextual Priming on Perceptions of Purportedly Paranormal and Ambiguous Auditory Stimuli

Reality television programs that explore purportedly paranormal phenomena with pseudoscientific research approaches have emerged in popular culture. These shows commonly feature electronic voice phenomena (EVP), whereby recording devices capture audio signals that are interpreted as paranormal messages. We compared perceptions for voices in EVP with actual speech, acoustic noise, and degraded speech. Some participants were told that the experiment was about speech intelligibility, whereas others were told that the experiment was about paranormal EVP. The paranormal prime increased the proportion of trials for which participants perceived voices in both EVP stimuli and degraded speech. When a voice was detected, low agreement was found regarding the content of EVP messages. In both priming conditions, participants reported general skepticism in the paranormal. Results are discussed in the context of theoretical perspectives on paranormal events, trait‐versus‐state accounts of paranormal beliefs, and pseudoscientific approaches to research. Copyright © 2014 John Wiley & Sons, Ltd.