Associative symmetry by pigeons after few-exemplar training

The present experiment investigated whether pigeons can show associative symmetry on a two-alternative matching-to-sample procedure. The procedure consisted of a within-subject sequence of training and testing with reinforcement, and it provided (a) exemplars of symmetrical responding, and (b) all prerequisite discriminations among test samples and comparisons. After pigeons had learned two arbitrary-matching tasks (A-B and C-D), they were given a reinforced symmetry test for half of the baseline relations (B1-A1 and D1-C1). To control for the effects of reinforcement during testing, two novel, nonsymmetrical responses were concurrently reinforced using the other baseline stimuli (D2-A2 and B2-C2). Pigeons matched at chance on both types of relations, thus indicating no evidence for symmetry. These symmetrical and nonsymmetrical relations were then directly trained in order to provide exemplars of symmetry and all prerequisite discriminations for a second test. The symmetrical test relations were now B2-A2 and D2-C2 and the nonsymmetrical relations were D1-A1 and B1-C1. On this test, 1 pigeon showed clear evidence of symmetry, 2 pigeons showed weak evidence, and 1 pigeon showed no evidence. The previous training of all prerequisite discriminations among stimuli, and the within-subject control for testing with reinforcement seem to have set favorable conditions for the emergence of symmetry in nonhumans. However, the variability across subjects shows that methodological variables still remain to be controlled.     

Model Implied Instrumental Variables (MIIVs): An Alternative Orientation to Structural Equation Modeling

Few dispute that our models are approximations to reality. Yet when it comes to structural equation models (SEMs), we use estimators that assume true models (e.g. maximum likelihood) and that can create biased estimates when the model is inexact. This article presents an overview of the Model Implied Instrumental Variable (MIIV) approach to SEMs from Bollen (1996). The MIIV estimator using Two Stage Least Squares (2SLS), MIIV-2SLS, has greater robustness to structural misspecifications than system wide estimators. In addition, the MIIV-2SLS estimator is asymptotically distribution free. Furthermore, MIIV-2SLS has equation-based overidentification tests that can help pinpoint misspecifications. Beyond these features, the MIIV approach has other desirable qualities. MIIV methods apply to higher order factor analyses, categorical measures, growth curve models, dynamic factor analysis, and nonlinear latent variables. Finally, MIIV-2SLS permits researchers to estimate and test only the latent variable model or any other subset of equations. In addition, other MIIV estimators beyond 2SLS are available. Despite these promising features, research is needed to better understand its performance under a variety of conditions that represent empirical applications. Empirical and simulation examples in the article illustrate the MIIV orientation to SEMs and highlight an R package MIIVsem that implements MIIV-2SLS.     

Investigating socio-emotional cognition in late preterm children: A case-control study

ABSTRACT

This study aimed to investigate socio-emotional cognitive competence in late preterm and term born children. Late preterm children (n = 53; 5–10 years) and full-term control children (n = 53; 5–10 years) were evaluated on the four socio-emotional cognitive tests of the Intelligence and Development Scales (IDS): emotion recognition, emotion regulation, social understanding, and social behavioural competence. Compared to full-term children, late preterm children (LPT) performed significantly worse on the emotion recognition and social behavioural competence tasks, but otherwise, no significant differences were found in emotion regulation and social understanding tasks. These findings support the conclusion that late-preterm birth may be associated with negative, but selective, socio-emotional cognitive difficulties. Targeted interventions aimed to limit the incidence of these dysfunctions during childhood could be quite important for LPT children.     

Cognitive and psychomotor tests as predictors of on-road driving ability in older primary care patients

This study examined the accuracy with which different cognitive and psychomotor assessment tools were able to predict driving ability among older primary care patients. A cross-sectional study of 50 older drivers (with an average age of 73.1 ± 7.0 years) was conducted. Participants who had been referred by their physicians for psychological assessment following a fitness-to-drive examination underwent both an on-road driving test and a cognitive assessment protocol that included the Senior Drivers Battery (SDB) that is currently administered at the Mobility and Land Transports Institute (MLTI) in Portugal, the Useful Field of View (UFOV) test, the Stroke Drivers Screening Assessment (SDSA), Addenbrooke’s Cognitive Examination Revised (ACE-R), the Trail Making Test, the Key Search test, and the Wechsler Adult Intelligence Scale (WAIS-III) Vocabulary and Block Design tests. Logistic regression analysis revealed that the performances of the participants on the SDSA, ACE-R, UFOV and SDB were the best predictors of on-road driving. Specific measures of processing speed and divided attention, visuospatial abilities, executive functions, psychomotor speed and global cognitive functioning may be useful for predicting unsafe driving. The practical implications of these findings are discussed with a view to developing new assessment models for determining driving fitness in older adults.