The Force/Force-Variability Relationship Under Controlled Temporal Conditions

Previously, an inverted U relationship between force and force variability was demonstrated in both static and dynamic responses. Recent research suggests that the inverted U function may be due to a lack of control of the temporal aspects of the response. To investigate this hypothesis, we examined the relationship between force and force variability in rapid movements under controlled temporal conditions. Subjects (N = 4) made rapid reversal responses with a horizontal lever (using elbow flexion and extension) such that the time to reversal (160 ms) and the distance to reversal (45°) were held constant in each of six load conditions (either 0, .260, .520, .780,1.040, or 1.560 kg added to the lever). When time to reversal and time to peak acceleration were held constant, a curvilinear relationship between force and force variability resulted, suggesting that the inverted U function is related to control of the temporal aspects of the response.     

Still cautious: Personality characteristics of extremely low birth weight adults in their early 30s

Extremely low birth weight survivors (ELBW; <1000 g) display a personality style characterized by cautiousness, shyness, and risk aversion in their 20s. We examined whether non-impaired ELBW survivors were still more cautious than their normal birth weight (NBW) peers at ages 30–35 and assessed the stability of this personality characteristic across approximately a decade in the oldest known cohort of ELBW survivors. Of the 154 participants tested at ages 22–26, 111 (i.e., 72%) of them returned approximately 10 years later [i.e., 69% (49/71) ELBW and 75% (62/83) NBW], and once again they completed the Eysenck Personality Questionnaire-Revised (EPQ-R). We created the same theoretically and empirically derived composite measure of cautiousness at each visit by summing the EPQ-R psychoticism scale (reverse scored) and the EPQ-R lie scale. We found that ELBW adults reported higher cautiousness than their NBW counterparts at ages 30–35. We also found that levels of cautiousness remained stable over approximately 10 years in both groups. Our findings suggest that individuals born at ELBW were more cautious than NBW peers and that this personality characteristic remained stable into their early 30s. The present study appears to be the first empirical demonstration of personality stability among adult ELBW survivors.     

Repeated measurement of salivary cortisol within and across days among shy young adults

Temperamental shyness emerges early in childhood and remains relatively stable throughout development and has been associated with high and low levels of the stress hormone cortisol. Studies examining the relation between shyness and cortisol have been limited because they have traditionally collected only one measure of cortisol on a single day in the laboratory, restricting the reliability and diurnal profile of the measure in the participant’s everyday environment. We collected 15 saliva samples across three separate days (i.e., upon waking, +60 min post-waking, +8 h post-waking, +10 h post-waking, and bedtime) in a sample of healthy young adults selected for high and low shyness in order to characterize a portion of the diurnal cortisol rhythm. Overall, shy individuals demonstrated relatively lower cortisol across the day and across multiple mornings than non-shy adults. Higher self-reported social anxiety across multiple measures was also related to lower total cortisol levels across all participants. The present study replicates and extends our previous findings of low salivary cortisol measured in the laboratory in shy adults to repeated measurement in their everyday environments.     

Methods for second order meta-analysis and illustrative applications

This paper presents methods for second order meta-analysis along with several illustrative applications. A second order meta-analysis is a meta-analysis of a number of statistically independent and methodologically comparable first order meta-analyses examining ostensibly the same relationship in different contexts. First order meta-analysis greatly reduces sampling error variance but does not eliminate it. The residual sampling error is called second order sampling error. The purpose of a second order meta-analysis is to estimate the proportion of the variance in mean meta-analytic effect sizes across multiple first order meta-analyses attributable to second order sampling error and to use this information to improve accuracy of estimation for each first order meta-analytic estimate. We present equations and methods based on the random effects model for second order meta-analysis for three situations and three empirical applications of second order meta-analysis to illustrate the potential value of these methods to the pursuit of cumulative knowledge.     

Functional hemispheric asymmetries of global/local processing mirrored by the steady-state visual evoked potential

While hemispheric differences in global/local processing have been reported by various studies, it is still under dispute at which processing stage they occur. Primarily, it was assumed that these asymmetries originate from an early perceptual stage. Instead, the content-level binding theory (Hübner & Volberg, 2005) suggests that the hemispheres differ at a later stage at which the stimulus information is bound to its respective level. The present study tested this assumption by means of steady-state evoked potentials (SSVEPs). In particular, we presented hierarchical letters flickering at 12 Hz while participants categorised the letters at a pre- cued level (global or local). The information at the two levels could be congruent or incongruent with respect to the required response. Since content-binding is only necessary if there is a response conflict, asymmetric hemispheric processing should be observed only for incongruent stimuli. Indeed, our results show that the cue and congruent stimuli elicited equal SSVEP global/local effects in both hemispheres. In contrast, incongruent stimuli elicited lower SSVEP amplitudes for a local than for a global target level at left posterior electrodes, whereas a reversed pattern was seen at right hemispheric electrodes. These findings provide further evidence for a level-specific hemispheric advantage with respect to content-level binding. Moreover, the fact that the SSVEP is sensitive to these processes offers the possibility to separately track global and local processing by presenting both level contents with different frequencies.     

Lay concepts of health and illness from a developmental perspective

Abstract

The concepts of children, adolescents and their mothers with regard to different aspects of health and illness in general and five specific diseases were explored in this study. An exploration with fully standardised questions and open answers was subjected to a content analysis. A reliable rating system was developed to score the sophistication of the answers. The study included 99 Ss of the age groups 5, 8, 12 and 16 years, as well as 48 mothers of the children. Many children and adolescents were able to define health positively (well-being) and not merely as the absence of illness. The definition of illness in general was frequently composed of somatic symptoms and disorders, feeling poorly and things one would like to accomplish but can't. The causality explanations of illness in general were dominated by contagion. The concepts of the older children and the mothers were richer, more elaborated, less concrete and less action-oriented than those of the younger children. However, abstract formulations and complex aspects of illness were very rarely expressed. In addition, concepts regarding the characteristics (definition, symptoms, causality, treatment and prevention) of five diseases (cold, measles, heart infarction, cancer and AIDS) were measured. The pattern of results was strongly influenced by age. By and large, the development of most disease concepts was linear with significant differences between age groups. Conversely, within a given age group, significant differences were found in the cognitive level of disease characteristics, either with respect to the same disease or between different diseases (“horizontal shifts”).     

The Parallel Episodic Processing (PEP) model: Dissociating contingency and conflict adaptation in the item-specific proportion congruent paradigm

The present work introduces a computational model, the Parallel Episodic Processing (PEP) model, which demonstrates that contingency learning achieved via simple storage and retrieval of episodic memories can explain the item-specific proportion congruency effect in the colour-word Stroop paradigm. The current work also presents a new experimental procedure to more directly dissociate contingency biases from conflict adaptation (i.e., proportion congruency). This was done with three different types of incongruent words that allow a comparison of: (a) high versus low contingency while keeping proportion congruency constant, and (b) high versus low proportion congruency while keeping contingency constant. Results demonstrated a significant contingency effect, but no effect of proportion congruence. It was further shown that the proportion congruency associated with the colour does not matter, either. Thus, the results quite directly demonstrate that ISPC effects are not due to conflict adaptation, but instead to contingency learning biases.     

Two-Year-Olds' Object Retrieval Based on Television: Testing a Perceptual Account

Two-year-olds frequently fail to use information provided by video to find objects hidden in an adjacent room. Schmitt and Anderson (2002) hypothesized that they fail to map the 2-dimensional (2D) video image onto the 3D layout of the search space. Two experiments tested whether 2-year-olds can successfully use information from video when the search space is 2D or when the information is provided verbally (by telling the child where the toy is hidden). In both experiments, children performed poorly in the video conditions but performed well in direct live experience comparison conditions, contradicting Schmitt and Anderson's hypothesis. Performance was above chance on the first trial in the video conditions, suggesting that 2-year-olds do have a memory of the hiding location, albeit one that is easily disrupted by perseverative errors on subsequent trials. Overall, the results are most consistent with the hypothesis that very young children give priority to direct experience over mediated information.