Discriminating the volume of motion-defined solids

We investigated the ability of human observers to discriminate an important global 3-D structural property, namely volume, of motion-defined objects. We used convex transparent wire-frame objects consisting of about 12 planar triangular facets. Two objects, vertically separated by 7°, were shown simultaneously on a computer display. Both revolved at 67°/sec around a common vertical axis through their centers of mass. Observers watched the objects monocularly for an average of three full rotations before they responded. We measured volume discrimination as a function of absolute volume (3–48 cm³; 1 m viewing distance) and shape (cubes, rods, and slabs of different regularity). We found that (1) volume discrimination performance can be described by Weber’s law, (2) Weber fractions depend strongly on the particular combination of shapes used (regular shapes, especially cubes, are easiest to compare, and similar shapes are easier to compare than different shapes), and (3) humans use a representation of volume that is more veridical and stable in the sense of repeatability than a strategy based on the average visible (2-D) area would yield.     

Models of burnout: Implications for interventions

Three process models of burnout are discussed, Cherniss' process model, Golembiewski's phase model and Leiter's process model. Empirical support for each model is reported. The models make different contributions to the problem of burnout and its development, and the kind of interventions that follow from each model seem to represent different targets. The strengths and weaknesses of the three models are assessed, and the relative merits of individual versus organizational level interventions are addressed. More model-driven research is necessary to reduce the problem of burnout for individuals and organizations.     

Tactile perception of thermal diffusivity

The thermal diffusivity of an object is a parameter that controls the rate at which heat is extracted from the hand when it touches that object. It is an important feature for distinguishing materials by means of touch. In order to quantitatively describe the ability of human observers to discriminate between materials on the basis of heat extraction rate, we conducted an experiment in which this heat extraction was performed in a controlled way. In different conditions, subjects were repeatedly asked to select from two stimuli the one that cooled faster. The discrimination threshold was around 43% of the extraction rate. A rate that was twice as slow also yielded twice the absolute threshold. When we halved the temperature difference between the beginning and end of the stimulus, the threshold did not change as much. In separate experiments, we investigated the different cues that were available in the stimulus: initial cooling rate and end temperature. Both cues were used for discrimination, but cooling rate seemed to be the most important.     

Maltreated Children's Memory of Stressful Removals from Their Biological Parents

The effects of stress on memory were examined through a study of 33 3 to 12‐year‐old maltreated children removed from their biological parents by the Child Protective Services because of an emergency (acute) or normal (planned) care order. Children's stress levels were rated by a researcher present during the removal and children's memory of the removal investigated at a later time. The type of removal significantly predicted children's level of stress. ‘Acute removal’ children remembered more from high‐stress phases of the removal than the ‘planned removal’ children. All children had more accurate memories of the low‐stress phases. Details remembered were rated as central or peripheral; more central information was recalled than peripheral information. The ‘acute removal’ children recalled more peripheral information from the high‐stress phases of the removal than the low‐stress phases, a difference, which was not present for the ‘planned removal’ children. Copyright © 2011 John Wiley & Sons, Ltd.     

Replications and extensions in arousal assessment for sex offenders with developmental disabilities

Three adult male sex offenders with developmental disabilities participated in phallometric assessments that involved repeated measures of arousal when exposed to various stimuli. Arousal assessment outcomes were similar to those obtained by Reyes et al. (2006). Additional data-analysis methods provided further information about sexual preferences, thus replicating and extending previous research. The results provide preliminary data for establishing a preference gradient by age. Implications for the use of repeated measures and preference gradients in arousal assessments are discussed.     

Prosocial norm violations fuel power affordance

The question of what makes people rise to power has long puzzled social scientists. Here we examined the novel hypothesis that power is afforded to individuals who exhibit prosocial norm violations—i.e., breaking rules for the benefit of others. Three experiments using different methods provide support for this idea. Individuals who deliberately ignored a prohibition to tilt a bus chair (Study 1; scenario) or to close a window (Study 2; film clip) were afforded more power than individuals who obeyed the rules, but only when the norm violation benefited others (i.e., by giving them more leg space or fresh air). Study 2 further showed that this effect was mediated by perceived social engagement, which was highest among prosocial norm violators. In Study 3 (face-to-face), a confederate who stole coffee from the experimenter's desk was afforded more power than a confederate who took coffee upon invitation, but only when he also offered coffee to the participant. We discuss implications for hierarchy formation, morality, and social engagement.     

Impulse control disorders in obese patients

The aim of this study was to determine the prevalence of impulse control disorders (ICDs) in morbidly obese individuals. One hundred bariatric surgery candidates were examined using a module of the Structured Clinical Interview for DSM-IV that has been developed for ICDs. Nineteen per cent suffered from at least one current ICD and 27% met the criteria for any lifetime ICD, most frequently skin picking (current, 8%; lifetime, 9%), compulsive buying (current 6%, lifetime 8%), and intermittent explosive disorder (current, 5%; lifetime, 10%). Patients with regular binge eating (N?=?25) reported significantly more often a history of at least one ICD compared with those without binge eating. The results indicate a high prevalence of ICDs among morbidly obese prebariatric surgery patients that are related to regular binge eating.     

Early communicative gestures and play as predictors of language development in children born with and without family risk for dyslexia

The present study investigated early communicative gestures, play, and language skills in children born with family risk for dyslexia (FR) and a control group of children without this inheritable risk at ages 12, 15, 18, and 24 months. Participants were drawn from the Tromsø Longitudinal study of Dyslexia (TLD) which follows children's cognitive and language development from age 12 months through Grade 2 in order to identify early markers of developmental dyslexia. Results showed that symbolic play and parent reported play at age 12 months and communicative gestures at age 15 months explained 61% of the variance in productive language at 24 months in the FR group. These early nonlinguistic measures seem to be potentially interesting markers of later language development in children born at risk for dyslexia.     

Ambient Assistive Technologies (AAT): socio-technology as a powerful tool for facing the inevitable sociodemographic challenges?

Due to the socio-demographic change in most developed western countries, elderly populations have been continuously increasing. Therefore, preventive and assistive systems that allow elderly people to independently live in their own homes as long as possible will become an economical if not ethical necessity. These respective technologies are being developed under the term "Ambient Assistive Technologies" (AAT). The EU-funded AAT-project Ambient Lighting Assistance for an Ageing Population (ALADIN) has established the long-term goal to create an adaptive system capable of improving the residential lighting conditions of single living elderly persons also aiming at supporting the preservation of their independence.