Are subjective cognitive complaints associated with executive functions and mental health of older adults?

Cognitive Processing - Subjective cognitive complaints are used to detect detrimental age-related variations in cognitive efficiency before cognitive decline occurs in late adulthood. Despite this,...     

Finite Mixtures of Hidden Markov Models for Longitudinal Responses Subject to Drop out

Abstract

Drop out is a typical issue in longitudinal studies. When the missingness is non-ignorable, inference based on the observed data only may be biased. This paper is motivated by the Leiden 85+ study, a longitudinal study conducted to analyze the dynamics of cognitive functioning in the elderly. We account for dependence between longitudinal responses from the same subject using time-varying random effects associated with a heterogeneous hidden Markov chain. As several participants in the study drop out prematurely, we introduce a further random effect model to describe the missing data mechanism. The potential dependence between the random effects in the two equations (and, therefore, between the two processes) is introduced through a joint distribution specified via a latent structure approach. The application of the proposal to data from the Leiden 85+ study shows its effectiveness in modeling heterogeneous longitudinal patterns, possibly influenced by the missing data process. Results from a sensitivity analysis show the robustness of the estimates with respect to misspecification of the missing data mechanism. A simulation study provides evidence for the reliability of the inferential conclusions drawn from the analysis of the Leiden 85+ data.     

Penguins perceive variations of source- and filter-related vocal parameters of species-specific vocalisations

Animal Cognition - Animal vocalisations encode a wide range of biological information about the age, sex, body size, and social status of the emitter. Moreover, vocalisations play a significant...     

Context-effect bias in capuchin monkeys (Sapajus spp.): exploring decoy influences in a value-based food choice task

Animal Cognition - Decision making is known to be liable to several context effects. In particular, adding a seemingly irrelevant alternative (decoy) to a set of options can modify preferences:...     

How do you think she feels? Vulnerability in empathy and the role of attention in school‐aged children born extremely preterm

The aim of this study was to examine empathic competence in children born extremely preterm (EP, <28 weeks) given vulnerabilities in social relationships. Empathy in typically developing children is mediated by executive functions. Executive functioning is also impaired in preterm children. Of particular interest in this study are the attentional components of executive functioning as mediators of empathic development. Thirty‐two 7‐year‐old EP children and 40 age‐matched term children participated in the Project K.I.D.S program and completed the Kids Empathy Development Scale (KEDS), Wechsler Intelligence Scale for Children (WISC‐IV), and Test of Everyday Attention for Children (TEA‐Ch). Children born extremely preterm exhibited poorer performance on all measures. The mediating role of attention in empathy competence was not supported by mediation modelling when FSIQ was controlled. As predicted, the EP group showed weaker empathic development relative to typically developing children. They also showed poorer attentional abilities. However, the effect of preterm birth on empathy was not mediated by executive‐level attention. The cognitive mechanisms underpinning poor empathy competence in EP children remain unclear. Future research needs to examine the role of inhibition, social–emotional recognition, and regulation.     

Singing more,singing harsher: occurrence of nonlinear phenomena in a primate’ song

Animal Cognition - Nonlinear phenomena (NLP) in animal vocalizations arise from irregularities in the oscillation of the vocal folds. Various non-mutually exclusive hypotheses have been put forward...