Experimental tests for the validation of active numerical human models

The development of numerical human models is a topic of current interdisciplinary research. In the field of automotive safety these models can be applied for the optimization of protection systems. In forensic research human models can be used for the investigation of injury mechanisms and for the prediction and reproduction of injury patterns. However, up to now human models have been validated on the basis of PMHS tests without considering the effects of muscle activity. This paper shows two experimental volunteer test set-ups for the generation of experimental validation data. In a pendulum set-up the influence of muscle activity on the human kinematics was investigated. A drop test set-up was developed for the analysis of the effects of muscle activity on impact response characteristics of muscle tissue. Experimental results, presented in this paper, can be used for the validation and optimization of active numerical human models.     

The Self-Report Symptom Inventory (SRSI): a New Instrument for the Assessment of Distorted Symptom Endorsement

Self-report instruments to detect distorted symptom reporting play a crucial role in clinical and forensic psychology. Most of the instruments currently available for this purpose only list implausible symptoms, which makes them easily identifiable as symptom validity tests. We developed the Self-Report Symptom Inventory (SRSI), combining five self-report scales of genuine symptoms with five pseudosymptom scales to screen for distorted symptom reporting in various domains (e.g., depression, post-traumatic stress). With a preliminary questionnaire version, we collected data in a heterogeneous sample (N?=?239) and performed an item selection, resulting in the final 107-item version. This version was evaluated in civil forensic patients, inmates of a prison, and a population-based sample; N?=?387). Data show that (a) SRSI pseudosymptom scores correlate highly (≥.80) with other instruments tapping distorted symptom endorsement, notably the Structured Inventory of Malingered Symptomatology; (b) High SRSI pseudosymptom scores tend to correlate with underperformance; and (c) The psychometric features of the SRSI are satisfactory, with internal consistency for the total scales >.90 and retest reliability >.85. The instrument appears to be a promising tool for examining symptom exaggeration, but further work is required, in particular cross-validation with other samples and different methods.     

Symptom Validity Testing in Somatoform and Dissociative Disorders: A Critical Review

When patients present with unusual, atypical, and difficult-to-understand complaints known as dissociative and somatoform disorders or medically unexplained symptoms, clinicians may administer symptom validity tests (SVTs) to determine whether or not the patient exhibits negative response bias. Such tests are especially informative in a context where incentives play a substantial role (e.g., the legal arena). If patients fail SVTs and exhibit negative response bias, how should that bias be interpreted? Some authors have argued that psychological problems (e.g., unconscious conflicts and depression) and circumstances (e.g., a cry for help) may explain such bias. In the current article, we critically review this “psychopathology = superordinate” position. We argue that (1) there is no empirical evidence to suggest that psychological problems may foster SVT failure per se and (2) that the “psychopathology = superordinate” position invites circular argumentation: to clarify the nature of the atypical symptoms, SVTs are administered and a negative response bias is found, which is explained away by the atypical symptoms. Negative response bias allows for only one conclusion: the patient’s self-report of symptoms and life history can no longer be taken at face value.     

Fairness to non-participants: a case for a practice-independent egalitarian baseline

Proponents of practice-dependent egalitarianism argue that egalitarian duties and entitlements only apply among participants in morally relevant practices. In this paper, I argue that these views are implausible because they allow for objectionable treatment of non-participants. I show that it is impossible, on the basis of practice-internal considerations alone, to determine the extent to which the pursuit of practices can permissibly limit the opportunities of non-participants. There are opportunities beyond the current holdings of practices to which no one has a privileged claim (such as unowned natural resources), and the distribution of which is a matter of justice. A just distribution of such unowned distributive goods, though, requires a practice-independent distributive baseline. I further show that such a baseline can only be egalitarian because all alternative baselines face serious objections. From this I conclude that any plausible theory of distributive justice must accept some form of equal practice-independent distributive entitlements.     

Symptom Validity Testing in Claimants with Alleged Posttraumatic Stress Disorder: Comparing the Morel Emotional Numbing Test, the Structured Inventory of Malingered Symptomatology, and the Word Memory Test

In independent medical examinations, unjustified claims of posttraumatic stress disorder (PTSD) are to be expected at an increased rate. In a prospective study, consecutive cases of patients claiming PTSD who underwent independent neuropsychiatric evaluation were analyzed. For 61 adult patients, results of three symptom validity tests (Morel Emotional Numbing Test, Structured Inventory of Malingered Symptomatology, and Word Memory Test) were available. Seventy percent of all claimants showed probable negative response bias in at least one of the three tests, 25% in all three tests. High probability of negative response bias was associated with symptom overreporting and demonstration of cognitive deficits in performance tests. The results indicate that high rates of uncooperativeness must be expected in civil forensic patients with claimed PTSD. A multi-method approach to the assessment of response distortion in PTSD claimants is indicated.     

Adolescent Obesity and Young Adult Psychosocial Outcomes: Gender and Racial Differences

Using a sample of 7,881 African American (915 males and 1,073 females) and White (2,864 males and 3,029 females) adolescents from Waves 1 and 3 of the National Longitudinal Study of Adolescent Health, this study examined the psychosocial consequences that obese adolescents encounter as they reach young adulthood. Results indicate that obesity among adolescent females is associated with a lower status attainment in young adulthood than normal weight adolescent females. In addition, obese adolescent females have more depressive symptoms in young adulthood than normal weight females, even after controlling for prior depressive symptoms in adolescence. Obesity status among adolescent males is not associated with poorer psychosocial outcomes in young adulthood. We did not find evidence of an interaction between obesity status and race, indicating no significant differences in psychosocial outcomes for obese White compared to obese African American adolescents.