Reevaluation of Piaget’s concept of egocentrism: New perspectives on a misunderstood idea

The paper states the goal of this special issue and briefly summarizes the topics of the papers addressed in this issue.     

Compatibility between tones, head movements, and facial expressions

The study tests the hypothesis of an embodied associative triangle among relative tone pitch (i.e., high or low tones), vertical movement, and facial emotion. In particular, it is tested whether relative pitch automatically activates facial expressions of happiness and anger as well as vertical head movements. Results show robust congruency effects: happiness expressions and upward head tilts are imitated faster when paired with high rather than low tones, while anger expressions and downward head tilts are imitated faster when paired with low rather than high tones. The results add to the growing evidence favoring an embodiment account that emphasizes multimodal representations as the basis of cognition, emotion, and action.     

Sensitivity to initial values in full non‐parametric maximum‐likelihood estimation of the two‐parameter logistic model

Parameters of the two‐parameter logistic model are generally estimated via the expectation–maximization (EM) algorithm by the maximum‐likelihood (ML) method. In so doing, it is beneficial to estimate the common prior distribution of the latent ability from data. Full non‐parametric ML (FNPML) estimation allows estimation of the latent distribution with maximum flexibility, as the distribution is modelled non‐parametrically on a number of (freely moving) support points. It is generally assumed that EM estimation of the two‐parameter logistic model is not influenced by initial values, but studies on this topic are unavailable. Therefore, the present study investigates the sensitivity to initial values in FNPML estimation. In contrast to the common assumption, initial values are found to have notable influence: for a standard convergence criterion, item discrimination and difficulty parameter estimates as well as item characteristic curve (ICC) recovery were influenced by initial values. For more stringent criteria, item parameter estimates were mainly influenced by the initial latent distribution, whilst ICC recovery was unaffected. The reason for this might be a flat surface of the log‐likelihood function, which would necessitate setting a sufficiently tight convergence criterion for accurate recovery of item parameters.     

Bidirectional links and concurrent development of parent-child relationships and boys' offending behavior

This study examined different types of longitudinal associations (i.e., directional links and overlapping developmental changes) between children's delinquency and the quality of parent-child relationships from middle childhood to late adolescence. We used 10-wave interview data of 503 boys, their primary caregivers, and their teachers. Our first aim was to unravel the direction of effects between parent-child relationships and children's offending. Cross-lagged panel models revealed bidirectional links over time between poorer quality parent-child relationships and boys' offending across late childhood (age 7-10), early adolescence (age 10-13) and middle adolescence (age 13-16). Second, we examined the associations between mean changes in delinquency, on the one hand, and mean changes in relationship quality, on the other hand. Although parent-child relationships improved during childhood, their quality decreased in early adolescence and remained stable in middle adolescence. Delinquency increased only in middle adolescence. In five out of six models, the slope factors of relationship quality and offending were strongly correlated, indicating that stronger increases in delinquency were associated with stronger decreases in parent-child relationship quality across childhood, early adolescence, and middle adolescence. The discussion focuses on the theoretical implications of these two types of longitudinal associations.     

Disentangling the adult attention-deficit hyperactivity disorder endophenotype: parametric measurement of attention

Attention deficit hyperactivity disorder (ADHD) persists frequently into adulthood. The decomposition of endophenotypes by means of experimental neuro-cognitive assessment has the potential to improve diagnostic assessment, evaluation of treatment response, and disentanglement of genetic and environmental influences. We assessed four parameters of attentional capacity and selectivity derived from simple psychophysical tasks (verbal report of briefly presented letter displays) and based on a "theory of visual attention." These parameters are mathematically independent, quantitative measures, and previous studies have shown that they are highly sensitive for subtle attention deficits. Potential reductions of attentional capacity, that is, of perceptual processing speed and working memory storage capacity, were assessed with a whole report paradigm. Furthermore, possible pathologies of attentional selectivity, that is, selection of task-relevant information and bias in the spatial distribution of attention, were measured with a partial report paradigm. A group of 30 unmedicated adult ADHD patients and a group of 30 demographically matched healthy controls were tested. ADHD patients showed significant reductions of working memory storage capacity of a moderate to large effect size. Perceptual processing speed, task-based, and spatial selection were unaffected. The results imply a working memory deficit as an important source of behavioral impairments. The theory of visual attention parameter working memory storage capacity might constitute a quantifiable and testable endophenotype of ADHD.     

Changes in processing of masked stimuli across early- and late-night sleep: a study on behavior and brain potentials

Sleep has proven to support the memory consolidation in many tasks including learning of perceptual skills. Explicit, conscious types of memory have been demonstrated to benefit particularly from slow-wave sleep (SWS), implicit, non-conscious types particularly from rapid eye movement (REM) sleep. By comparing the effects of early-night sleep, rich in SWS, and late-night sleep, rich in REM sleep, we aimed to separate the contribution of these two sleep stages in a metacontrast masking paradigm in which explicit and implicit aspects in perceptual learning could be assessed separately by stimulus identification and priming, respectively. We assumed that early sleep intervening between two sessions of task performance would specifically support stimulus identification, while late sleep would specifically support priming. Apart from overt behavior, event-related EEG potentials (ERPs) were measured to record the cortical mechanisms associated with behavioral changes across sleep. In contrast to our hypothesis, late-night sleep appeared to be more important for changes of behavior, both for stimulus identification, which tended to improve across late-night sleep, and for priming, with the increase of errors induced by masked stimuli correlating with the duration of REM sleep. ERP components proved sensitive to presence of target shapes in the masked stimuli and to their priming effects. Of these components, the N2 component, indicating processing of conflict, became larger across early-night sleep and was related to the duration of S4 sleep, the deepest substage of SWS containing particularly high portions of EEG slow waves. These findings suggest that sleep promotes perceptual learning primarily by its REM sleep portion, but indirectly also by way of improved action monitoring supported by deep slow-wave sleep.