Prechtl's assessment of general movements: a diagnostic tool for the functional assessment of the young nervous system

General movements (GMs) are part of the spontaneous movement repertoire and are present from early fetal life onwards until the end of the first half a year of life. GMs are complex, occur frequently, and last long enough to be observed properly. They involve the whole body in a variable sequence of arm, leg, neck, and trunk movements. They wax and wane in intensity, force and speed, and they have a gradual beginning and end. Rotations along the axis of the limbs and slight changes in the direction of movements make them fluent and elegant and create the impression of complexity and variability. If the nervous system is impaired, GMs loose their complex and variable character and become monotonous and poor. Two specific abnormal GM patterns reliably predict later cerebral palsy: 1) a persistent pattern of cramped-synchronized GMs. The movements appear rigid and lack the normal smooth and fluent character. Limb and trunk muscles contract and relax almost simultaneously. 2) The absence of GMs of fidgety character. So-called fidgety movements are small movements of moderate speed with variable acceleration of neck, trunk, and limbs in all directions. Normally, they are the predominant movement pattern in an awake infant at 3 to 5 months. Beside a sensitivity and specificity of 95% each, the assessment of GMs is quick, noninvasive, even nonintrusive, and cost-effective compared with other techniques, e.g., magnetic resonance imaging, brain ultrasound, and traditional neurological examination.     

Colour constancy in goldfish and man: influence of surround size and lightness

Colour constancy was investigated by using a series of 10 simultaneously presented surface colours ranging in small steps from green through gray to red-purple. Goldfish were trained to select one medium test field when the entire setup was illuminated with white light. In the tests, either red or green illumination was used. Colour constancy, as inferred from the choice behaviour, was perfect under green illumination when the test fields were presented on a gray or a white background, but imperfect on a black background. Under red illumination and a white background, however, colour constancy was overcompensated. Here, a colour contrast effect was observed. The influence of background lightness was also found when the surround was restricted to a narrow annulus of 4-11 mm width (test field diameter: 14 mm). By applying colour metrics it could be shown that the von Kries coefficient law can describe the overall effect of colour constancy. For an explanation of the effect of surround size and lightness, lateral inhibitory interactions have to be assumed in addition, which are also responsible for simultaneous colour contrast. Very similar results were obtained in experiments with the same colours in human subjects. They had to name the test field appearing 'neutral' under the different illumination and surround conditions, as tested in the goldfish experiment.     

Patterns of brain acetylcholine release predict individual differences in preferred learning strategies in rats

Acetylcholine release was measured simultaneously in the hippocampus and dorsal striatum of rats before and during training on a maze that could be learned using either a hippocampus-dependent spatial strategy or a dorsal striatum-dependent turning strategy. A probe trial administered after rats reached a criterion of 9/10 correct responses revealed that about half of the rats used a spatial strategy and half a turning strategy to solve the task. Acetylcholine release in the hippocampus, as well as the ratio of acetylcholine release in the hippocampus vs. the dorsal striatum, measured either before or during training, predicted these individual differences in strategy selection during learning. These findings suggest that differences in release of acetylcholine across brain areas may provide a neurobiological marker of individual differences in selection of the strategies rats use to solve a learning task.     

Argumentation and Explanation in Conceptual Change: Indications From Protocol Analyses of Peer-to-Peer Dialog

In this paper we attempt to identify which peer collaboration characteristics may be accountable for conceptual change through interaction. We focus on different socio-cognitive aspects of the peer dialog and relate these with learning gains on the dyadic as well as the individual level. The scientific topic that was used for this study concerns natural selection, a topic for which students' intuitive conceptions have been shown to be particularly robust. Learning tasks were designed according to the socio-cognitive conflict instructional paradigm. After receiving a short instructional intervention on natural selection, paired students were asked to collaboratively construct explanations for certain evolutionary phenomena while engaging in dialectical argumentation. Two quantitative coding schemes were developed, each with a different granularity. The first assessed discrete dialog moves that pertained to dialectical argumentation and to consensual explanation development. The second scheme characterized the dialog as a whole on a number of socio-cognitive dimensions. Results from analyses on the dyadic as well as the individual level revealed that the engagement in dialectical argumentation predicted conceptual learning gains, whereas consensual explanation development did not. These findings open up new venues for research on the mechanisms of learning in and from peer collaboration.     

Tonic Activity Level in the Right Prefrontal Cortex Predicts Individuals' Risk Taking

ABSTRACT— Human risk taking is characterized by a large amount of individual heterogeneity. In this study, we applied resting-state electroencephalography, which captures stable individual differences in neural activity, before subjects performed a risk-taking task. Using a source-localization technique, we found that the baseline cortical activity in the right prefrontal cortex predicts individual risk-taking behavior. Individuals with higher baseline cortical activity in this brain area display more risk aversion than do other individuals. This finding demonstrates that neural characteristics that are stable over time can predict a highly complex behavior such as risk-taking behavior and furthermore suggests that hypoactivity in the right prefrontal cortex might serve as a dispositional indicator of lower regulatory abilities, which is expressed in greater risk-taking behavior.     

Characteristics of ADHD Related to Executive Function: Differential Predictions for Creativity-Related Traits

Although the relationship between creativity and ADHD is uncertain, recent studies examining how dimensionally assessed characteristics of ADHD relate to creativity and divergent thinking in adults suggest an occasional positive, linear relationship between the constructs. However, the executive functions proposed to underlie characteristics of ADHD have not been examined in relation to creativity. This study was conducted to determine how different characteristics of ADHD related to executive functioning (as assessed by the Brown ADD Scales) predict different components of figural divergent thinking, intellectual risk-taking, and creative self-efficacy. Undergraduate engineering students (N = 60) completed the Brown ADD Scales, a figural divergent thinking task, and self-report measures of intellectual risk-taking and creative self-efficacy. A series of multivariate regression models demonstrated that several components of divergent thinking (i.e., fluency, originality, and resistance to closure) were predicted by different characteristics of ADHD. Although fluency was predicted by affect only and originality was predicted by activation only, resistance to closure was predicted by activation, effort, and attention. Additionally, intellectual risk-taking was predicted by memory, effort, and activation, whereas creative self-efficacy was predicted by effort. The implications of these results relating to the relationship between ADHD and creativity, as well as for engineering undergraduate education are discussed.     

Accuracy of Social Perception: An Integration and Review of Meta‐Analyses

This review examines the overall accuracy of social perception across several research topics and identifies factors that influence the accuracy of social perception. Findings from 14 meta‐analyses examining topics such as social/personality judgments, health judgments, legal judgments, and academic/vocational judgments were obtained. Social perception accuracy was generally moderate, yielding an average effect size (r) of .32. However, individual meta‐analytic effects varied widely, with some topics yielding small effects (e.g., lie detection, eyewitness identification) and other topics yielding large effects (e.g., educational judgments, health judgments). Several moderators of social perception accuracy were identified, including the nature of the information source, familiarity of the target, type of personality trait, and severity of the outcome being judged. These findings provide a comprehensive summary and novel integration of disparate findings on the accuracy of social perception. Concluding remarks highlight avenues for future research and call for cross‐disciplinary collaborations that would enhance our understanding of social perception.     

Brightness matching, brightness cancellation, and increment threshold in the Ehrenstein illusion

Matching and cancellation techniques were used to measure the relative strength of the Ehrenstein illusion in dark figures on a light background (negative contrast) and light figures on a dark background (positive contrast). Brightness enhancement on the former was shown to be maximally 0.28 log unit (relative to the detection threshold), and darkness enhancement on the latter 0.43 log unit. Values differed little with figure-ground contrast (down to a minimum of +/- 0.5), but decreased with decreasing level of illumination. The luminance increment (decrement) needed to match the illusory brightness (darkness) was similar in size to the luminance decrement (increment) needed to cancel the illusion. The increment threshold for a small test flash measured in three locations relative to the subjective contour delineating the illusion did not differ systematically. The results are compatible with a neurophysiological explanation of the Ehrenstein illusion in terms of line-induced lateral interaction in hypercomplex receptive fields.     

The evaluation of an equine-assisted therapy programme with a group of boys in a youth care facility

The goal of this study was to evaluate the efficacy of an equine-assisted therapy programme aimed at improving the psychological well-being of boys in a custodial school of industry. Participants were 39 boys who live in a youth care facility for boys who display problem behaviour. They were from different cultural groups (Black, Coloured, and White) and aged between 14 and 18 years. Horses were utilised in the structured sessions to help the boys learn different coping skills through experiential learning. Data were collected on the boys’ level of coping and subjective well-being in order to assess the efficacy of the programme. The data were analysed using independent groups t-test comparisons. The results showed that the programme significantly improved the boys’ subjective well-being, problem focused coping, and emotion focused coping. However, their levels of dysfunctional coping were unchanged following the intervention. An equine-assisted therapy programme appears to show modest evidence of enhancing psychological well-being of adolescent boys in custodial care.