Empirical underidentification in estimating random utility models: The role of choice sets and standardizations

A standard approach to distinguishing people’s risk preferences is to estimate a random utility model using a power utility function to characterize the preferences and a logit function to capture choice consistency. We demonstrate that with often-used choice situations, this model suffers from empirical underidentification, meaning that parameters cannot be estimated precisely. With simulations of estimation accuracy and Kullback–Leibler divergence measures we examined factors that potentially mitigate this problem. First, using a choice set that guarantees a switch in the utility order between two risky gambles in the range of plausible values leads to higher estimation accuracy than randomly created choice sets or the purpose-built choice sets common in the literature. Second, parameter estimates are regularly correlated, which contributes to empirical underidentification. Examining standardizations of the utility scale, we show that they mitigate this correlation and additionally improve the estimation accuracy for choice consistency. Yet, they can have detrimental effects on the estimation accuracy of risk preference. Finally, we also show how repeated versus distinct choice sets and an increase in observations affect estimation accuracy. Together, these results should help researchers make informed design choices to estimate parameters in the random utility model more precisely.     

Sexual activity is inversely related to women’s perceptions of the facial attractiveness of unknown men

A study was conducted to assess whether individual differences in sexual activity during the past 30 days, in particular penile–vaginal intercourse (PVI; which is associated with measures of relationship quality), are related to the perception of the facial attractiveness of unknown men. Forty-five women reported the frequency of a variety of sexual behaviors and rated the facial attractiveness and friendliness of 24 men. Women who reported more frequent orgasm from masturbation rated men as less friendly. This finding might be reflective of the more anti-social attitude associated with more frequent masturbation. The results also show that women who engaged more frequently in most kinds of sexual behavior, not only PVI, considered unknown men to be less facially attractive. That is, individuals who engage more frequently in a variety of sexual behaviors with their partner perceived unknown men as less attractive and thereby may be less susceptible to the lure of other (or if the only sexual behavior is masturbation, any) men.     

Trunk and center of mass movements during gait in children with juvenile idiopathic arthritis

Motion of the body center of mass (CoM) can often indicate the overall effect of the strategy of forward progression used. In the present study, focus is placed on trunk movements in the sagittal, coronal, and transverse/rotation plane, as well as placement of the CoM, during gait in children with juvenile idiopathic arthritis (JIA). Seventeen children with JIA, all with polyarticular lower extremity involvement were examined before and approximately two weeks after treatment with intra-articular cortico-steroid injections. Movement was recorded with a 6-camera 3D motion analysis system in both the children with JIA and in 21 healthy controls. Trunk and center of mass movements were compared between JIA and controls, and effects of intra-articular cortico-steroid treatment were evaluated. Children with JIA were more posteriorly tilted in the trunk, contrary to the common clinical impression, and had their CoM placed more posterior and off-centred, which may have been a result of pain. With such knowledge, it might be possible to better understand the effects of their pain and involvement, and ultimately to plan a treatment strategy for improving their gait patterns.     

Zur Dynamik der Interaktion in der Supervision

The manifold functions of a supervisor in following the course of complex processes together with the trainee, are: ? to keep the goals of the supervision in view, ? to establish a teaching alliance and to support the wish and ambitions of the candidate to learn, ? to build a platform for the complex interactions with the trainee with regard to the dynamics of the training situation and keeping in mind the institutional influences, ? to lay down the setting for the work, ? to explore and to reflect how transference and counter-transference influence the interaction between patient and analyst as well as between trainee and supervisor, ? to examine these interactions together focussing continuously on the interaction between candidate and patient, and to encourage the candidate to do the same on his own, ? to continuously formulate hypotheses about the core conflict, the transference phenomena and resistance of the patient, ? to explore and reflect on the cooperative work.     

The problem of serial order in behavior: Lashley's legacy

In a prescient paper Karl Lashley (1951) rejected reflex chaining accounts of the sequencing of behavior and argued instead for a more cognitive account in which behavioral sequences are typically controlled with central plans. An important feature of such plans, according to Lashley, is that they are hierarchical. Lashley offered several sources of evidence for the hierarchical organization for behavioral plans, and others afterward provided more evidence for this hypothesis. We briefly review that evidence here and then shift from a focus on the structure of plans (Lashley's point of concentration) to the processes by which plans are formed in real time. Two principles emerge from the studies we review. One is that plans are not formed from scratch for each successive movement sequence but instead are formed by making whatever changes are needed to distinguish the movement sequence to be performed next from the movement sequence that has just been performed. This plan-modification view is supported by two phenomena discovered in our laboratory: the parameter remapping effect, and the handpath priming effect. The other principle we review is that even single movements appear to be controlled with hierarchically organized plans. At the top level are the starting and goal postures. At the lower level are the intermediate states comprising the transition from the starting posture to the goal posture. The latter principle is supported by another phenomenon discovered in our lab, the end-state comfort effect, and by a computational model of motor planning which accounts for a large number of motor phenomena. Interestingly, the computational model hearkens back to a classical method of generating cartoon animations that relies on the production of keyframes first and the production of interframes (intermediate frames) second.     

Effects of object complexity and type on the gaze behavior of children with pervasive developmental disorder

The looking behavior of children with pervasive developmental disorder (PDD) and age- and IQ-matched normal control children was studied using infrared oculography. Stimuli varying in complexity and topic were presented to test whether children with PDD have specific abnormalities in looking behavior to complex stimuli and/or to faces. All children showed more and longer fixations on the complex objects than on the simple objects, especially the complex nonsense figure, but group differences were not found. The results show no evidence for specific abnormalities in looking behavior to either faces or to complex stimuli in high functioning children with PDD.     

Effect of colour pop-out on the recognition of letters in crowding conditions

The crowding effect of adjacent objects on the recognition of a target can be reduced when target and flankers differ in some feature, that is irrelevant to the recognition task. In this study, the mechanisms of this effect were explored using targets and flankers of the same and different colours. It was found that facilitation nearly equal to that of differently coloured targets and flankers can be observed with a differently coloured background blob in the location of the target. The different-colour effect does not require advance knowledge of the target and flanker colours, but the effect increases in the course of three trials with constant mapping of colours. The results are consistent with the notion of exogenous attention that facilitates the processing at the most salient locations in the visual field.     

What Research Has to Say About Gender-Linked Differences in CMC and Does Elementary School Children’s E-mail Use Fit This Picture?

This paper first reviews the literature on computer mediated communication (CMC) to examine whether claims about gender-linked differences in specific attitudes, styles and content in CMC have been validated. Empirical studies were limited, with considerable variation in audiences, tasks, and contexts that was related to varied outcomes. The paper next describes an empirical study on the e-mail communication of elementary school children from ten Dutch classrooms. No gender-linked preference for a person or task-oriented attitude was found. Girls significantly more often employed an elaborate style. Differences between boys and girls on content of communication were subtle rather than robust. The conclusion discusses the functional embedding of CMC and the need to examine jointly antecedents, language acts and consequences.     

Fibromyalgie und Leistungseinschränkung

Interdisciplinary guidelines allowed for new quality standards in pain appraisal. Simultaneously, the scientific notion of fibromyalgia changed from a subjectively overvalued malaise to a central disturbance of coping with stress, which is neurobiologically determined. Therefore, in this article a psychosomatics-based guide is given for the socio-medical appraisal of fibromyalgia with reference to the new International Classification for Functioning and Disability (ICF) of the World Health Organization (WHO). As illustration a case study is presented.