Explaining Referential Stability of Physics Concepts: The Semantic Embedding Approach

The paper discusses three different ways of explaining the referential stability of concepts of physics. In order to be successful, an approach to referential stability has to provide resources to understand what constitutes the difference between the birth of a new concept with a history of its own, and an innovative step occurring within the lifetime of a persisting concept with stable reference. According to Theodore Arabatzis’ ‘biographical’ approach (Representing Electrons 2006), the historical continuity of representations of the electron manifests itself by the numerical stability of experimental parameters like the charge-to-mass ratio, and the continued acceptance of earlier experiments as manifestations of electron properties. I argue, against Arabatzis’ approach, that the stability of experimental parameters justifies the assumption that there exists a chain of representations of a unique theoretical entity only if this stability occurs against the background of evidence for theoretical continuity. The Bain/Norton approach proposes to add exactly this element to the picture, but fails to reach its aim by focusing on formal similarities of Hamiltonians as an indicator of theoretical continuity. I shall argue that theoretical continuity has to be demonstrated rather on the level of particular solutions. This task is accomplished by the semantic embedding approach by means of defining a co-reference criterion for theoretical terms requiring the existence of semantic embedding relations between the terms that occur in particular solutions of different theories.     

When do motor behaviors (mis)match affective stimuli? An evaluative coding view of approach and avoidance reactions

Affective-mapping effects between affective stimuli and lever movements are critically dependent upon the evaluative meaning of the response labels that are used in the task instructions. In Experiments 1 and 2, affective-mapping effects predicted by specific-muscle-activation and distance-regulation accounts were replicated when the standard response labels towards and away were used but were reversed when identical lever movements were labeled downwards and upwards. In Experiment 3, affective-mapping effects were produced with affectively labeled right and left lever movements that are intrinsically unrelated to approach and avoidance. Experiments 4 and 5 revealed that affective-mapping effects are not mediated by memory retrieval processes and depend on the execution of affectively coded responses. The results support the assumption that evaluative implications of action instructions assign affective codes to motor responses on a representational level that interact with stimulus evaluations on a response selection stage.     

Biased information search in homogeneous groups: confidence as a moderator for the effect of anticipated task requirements

When searching for information, groups that are homogeneous regarding their members' prediscussion decision preferences show a strong bias for information that supports rather than conflicts with the prevailing opinion (confirmation bias). The present research examined whether homogeneous groups blindly search for information confirming their beliefs irrespective of the anticipated task or whether they are sensitive to the usefulness of new information for this forthcoming task. Results of three experiments show that task sensitivity depends on the groups' confidence in the correctness of their decision: Moderately confident groups displayed a strong confirmation bias when they anticipated having to give reasons for their decision but showed a balanced information search or even a dis confirmation bias (i.e., predominately seeking conflicting information) when they anticipated having to refute counterarguments. In contrast, highly confident groups demonstrated a strong confirmation bias independent of the anticipated task requirements.     

Jugenddelinquenz - Aktuelle Präventions - und Interventionskonzepte

This article presents an overview on the concepts and the outcomes of current prevention and intervention measures for juvenile delinquency and offender rehabilitation. The main focus is on a discussion of recent evaluation results. Social skills training, parent training programs, family-oriented early intervention, and multimodal school-based programs are discussed as prevention measures. Cognitive-behavioral and family therapy as well as diverse concepts of offender rehabilitation (e.g., boot camps) are delineated as intervention measures. The article concludes with an integrated evaluation of these results and a discussion of general theoretical and strategic issues.     

Verläufe bei sexuellen Tötungen

This article summarizes main results of studies on forensic psychiatric court reports on 166 men who had been persecuted between 1963 and 1991 for a sexual offence leading to the death of the victim. Comparing perpetrators with a single victim and those with multiple victims we found similar results as in two previous studies with smaller samples: Multiple sexual homicide perpetrators showed more often sexual sadism and other paraphilias, as well as antisocial, schizoid and sadistic personality disorders. Follow-up data from the federal criminal records could be obtained for 139 offenders. Ninety perpetrators had been released after a mean detention of 12.2 years, whereas the 49 offenders who were still in prison or forensic psychiatric hospitals had been detained for a mean period of 20.6 years. The non-released offenders showed more often paraphilias as well as antisocial and sadistic personality disorders than the released perpetrators. Paraphilias and antisocial personality traits are empirically well proven risk factors for criminal recidivism with sexual reoffences. In addition, the non-released sexual homicide perpetrators had higher scores in all applied risk assessment instruments (PCL-R, HCR-20, SVR-20, Static-99). Among the released offenders only 1.1% (n=1) reoffended with a completed homicide and 2.2% (n=2) with attempted homicide. The recidivism rates with sexual and other violent reoffences in this sample of sexual homicide perpetrators were similar to those in a large meta-analysis on recidivism in sexual offenders by Hanson and Morton-Bourgon (4). Since well established risk factors had apparently been “used-up” for the decisions about release or non-release, in the follow-up data about the released offenders only age at the sexual homicide and age at the time of release were found as risk factors for recidivism with any violent (sexual or non-sexual) reoffence, i.e. the younger the offender at the time of the homicide and the younger at the time of release, the more likely is the risk of violent reoffending.     

Diminished cooperativeness of psychopaths in a prisoner's dilemma game yields higher rewards

Maladaptive social behavior is one of the defining characteristics of psychopathic personality disorder. Nevertheless, maladaptive social behavior has only rarely been observed among psychopaths in experimentally controlled situations. The authors assessed the behavior of criminal psychopaths from high-security psychiatric hospitals in a computer simulation of a social dilemma situation. The psychopaths showed a markedly higher proneness to competitive (i.e., noncooperative) behavior than did healthy adults from the general population. The odds ratio between defection and being a psychopath was estimated at 7.86 in the sample. The probability to choose selfish instead of cooperative behavior was significantly linked to the following subscales of the Psychopathy Personality Inventory-Revised (S. O. Lilienfeld & M. R. Widows, 2005): rebellious nonconformity, Machiavellian egocentricity, and the total score. On average, the psychopathic participants accumulated higher gain and more strongly exploited their counterpart than did the healthy participants.     

A fast numerical algorithm for the estimation of diffusion model parameters

In this paper, we describe a new algorithmic approach for parameter estimation in Ratcliff's [(1978). A theory of memory retrieval. Psychological Review, 85 (2), 59-108] diffusion model. This problem, especially if inter-trial variabilities of parameters are included in the model, is computationally very expensive; the parameter estimation procedure often takes a long time even with today's high-speed computers. The algorithm described here makes the calculation of the cumulative distribution functions for predicted process durations computationally much less expensive. This improvement is achieved by solving the Kolmogorov backward equation numerically instead of employing the previously used closed form solution. Additionally, the algorithm can determine the optimum fit for one of the model parameters (the starting point z) directly, thereby reducing the dimension of the parameter search space by one. The resulting method is shown to be notably faster than the standard (closed-form solution) method for parameter estimation.     

Both predator and prey: emotional arousal in threat and reward

This research examined the psychophysiology of emotional arousal anticipatory to potentially aversive and highly pleasant outcomes. Human brain reactions (event-related potentials) and body reactions (heart rate, skin conductance, the probe startle reflex) were assessed along motivational gradients determined by apparent distance from sites of potential punishment or reward. A predator-prey survival context was simulated using cues that signaled possible money rewards or possible losses; the cues appeared to loom progressively closer to the viewer, until a final step when a rapid key response could ensure reward or avoid a punishing loss. The observed anticipatory response patterns of heightened vigilance and physiological mobilization are consistent with the view that the physiology of emotion is founded on action dispositions that evolved in mammals to facilitate survival by dealing with threats or capturing life-sustaining rewards.     

Stimulus frequency influences spontaneous perceptual reversals in ambiguous apparent motion

The temporal integration of continuous sensory information into a temporally extended percept becomes evident in spontaneous reversals of ambiguous apparent motion. To study the temporal relation of spontaneous percept reversals and temporal stimulus properties, we systematically varied presentation frequency in an ambiguous-apparent-motion paradigm. Moreover, we triggered percept reversals in a manner that was not consciously perceived by manipulating the duration of single frames. We found that the reversal rate depended on the stimulus frequency (with higher frequencies resulting in faster percept reversals) and that we could externally trigger perceptual reversals. Our findings support the idea that spontaneous reversals of ambiguous apparent motion are influenced by bottom-up effects at early processing levels. The paradigm allows for specific contrasts of spontaneous and externally triggered (but otherwise identical) perceptual reversals and, by this means, for further study of the underlying mechanisms.     

Perfectionism and performance in a new basketball training task: Does striving for perfection enhance or undermine performance?

ObjectivesIn the psychology of sport and exercise, the question of how perfectionism affects performance is highly debated. While some researchers have identified perfectionism as a hallmark quality of elite athletes, others see perfectionism as a maladaptive characteristic that undermines, rather than helps, athletic performance. Against this background, the purpose of the present study was to investigate how different aspects of perfectionism predict performance and performance increments.MethodA study was conducted with 122 undergraduate athletes to investigate how perfectionism during training affects performance and performance increments in a series of trials with a new basketball training task. Two aspects of perfectionism were examined: striving for perfection and negative reactions to imperfection.DesignThe design was a correlational prospective design.ResultsResults showed that striving for perfection during training predicted higher performance in the new task. In contrast, negative reactions to imperfection predicted lower performance when athletes attempted the task for the first time, once the positive influence of striving for perfection on task performance was partialled out. However, negative reactions to imperfection did not undermine performance in the consecutive trials. On the contrary, athletes with both high levels of striving for perfection and high levels of negative reactions to imperfection showed the greatest performance increments over the series of trials.ConclusionThe findings suggest that perfectionism is not necessarily a maladaptive characteristic that generally undermines sport performance. Instead, when learning a new training task, perfectionism may enhance performance and lead to performance increments over repeated trials.