Aggregating Sets of Judgments: Two Impossibility Results Compared1

The ``doctrinal paradox'' or ``discursive dilemma'' shows that propositionwise majority voting over the judgments held by multiple individuals on some interconnected propositions can lead to inconsistent collective judgments on these propositions. List and Pettit (2002) have proved that this paradox illustrates a more general impossibility theorem showing that there exists no aggregation procedure that generally produces consistent collective judgments and satisfies certain minimal conditions. Although the paradox and the theorem concern the aggregation of judgments rather than preferences, they invite comparison with two established results on the aggregation of preferences: the Condorcet paradox and Arrow's impossibility theorem. We may ask whether the new impossibility theorem is a special case of Arrow's theorem, or whether there are interesting disanalogies between the two results. In this paper, we compare the two theorems, and show that they are not straightforward corollaries of each other. We further suggest that, while the framework of preference aggregation can be mapped into the framework of judgment aggregation, there exists no obvious reverse mapping. Finally, we address one particular minimal condition that is used in both theorems – an independence condition – and suggest that this condition points towards a unifying property underlying both impossibility results.     

Evaluating validity and test-retest reliability in four drive for muscularity questionnaires

The current study assessed relationships among four commonly used drive for muscularity questionnaires, along with their 7 and 14 day test-retest reliability. Sample 1 was comprised of young British adult males (N=272; M(AGE)=20.3) who completed the questionnaires once. Sample 2, a group of young British adult males (N=54, M(AGE)=19.3), completed the questionnaires three times spaced 7 and 14 days apart. Correlations among Sample 1 ranged from .20 to .82 providing evidence for concurrent and discriminant validities. Evidence for test-retest reliability emerged with intraclass correlations ranging from .78 to .95 (p<.001) and generally nonsignificant t-tests (p>.05). Overall, the data support the psychometric properties of the drive for muscularity inventories; however, the shared variance (35-67%) hints that refinement is possible.     

Posture based motor planning in a sequential grasping task

Movement planning in sequential tasks is revealed by grasping postures. We explored aspects of planning a sequential drawer opening and object manipulation task with regard to arm and torso postures. We conducted a detailed kinematic analysis of joint postures at the wrist, elbow, and shoulder for a one-grasp and a two-grasp sequence of movement. The second of the two-grasp sequence was constrained (uncomfortable). We predicted that planning for the second grasp in a two-grasp sequence would influence arm, torso, and whole-body postures at the first grasp. Participants prepared for the second grasp by adjusting the posture of the elbow and shoulder and the distance they stepped to the drawer. The joint postures at the elbow and shoulder changed in the direction of the intended object grasp. These findings show that anticipatory adjustments are revealed at postures other than the end-effector and lend insight into the mechanisms of sequential movement planning.     

Einzel- und Paarintervention f��r depressive Koronarpatienten

Depressive symptoms in patients presenting with coronary heart disease have an impact on quality of life, health behavior, and prognosis. The psychotherapeutic interventions which had been tested for their efficacy in previous randomized controlled trials, showed only minor effects. A stepwise approach consisting of individual and group psychotherapeutic interventions was tested for efficacy in a German multicenter study. The presented paper describes the therapeutic procedure for two individual sessions and one couple session by means of case examples. The main focus was to determine depressive symptoms along with underlying maladaptive personality traits such as negative affectivity and social inhibition (type D pattern). Depressive mood, disappointments and mortifications both in private and professional life and also during the previous treatment are verbalized. Dysfunctional relation patterns and maladaptive sickness behavior are taken up by the psychotherapist and alternative behavior patterns are developed. The objective of the couple session is strengthening the partnership resources and offering relief of fears and worries relative to the heart disease. The psychotherapeutic procedure is psychodynamically oriented but also contains cognitive-behavioral and interactional treatment approaches.     

When the brain decides: a familiarity-based approach to the recognition heuristic as evidenced by event-related brain potentials

Humans can make fast and highly efficient decisions by using simple heuristics that are assumed to exploit basic cognitive functions. In the study reported here, we used event-related potentials (ERPs) to disclose the psychological mechanisms underlying one of the most frugal decision rules, namely, the recognition heuristic. According to this heuristic, whenever two objects have to be ranked by a specific criterion and only one object is recognized, the recognized object is ranked higher than the unrecognized object. Using a standard recognition-heuristic paradigm, we predicted participants' decisions by analyzing an ERP correlate of familiarity-based recognition occurring 300 to 450 ms after stimulus onset. The measure remained a significant predictor even when later ERP correlates were taken into account. These findings are evidence for the thesis that simple heuristics exploit basic cognitive processes. Specifically, the findings show that familiarity--that is, recognition in the absence of recollection--contributes to decisions made on the basis of such heuristics.     

Internetbasierte Vorbereitung auf eine station?re psychosomatisch-psychotherapeutische Behandlung

Background

Encouraged by promising results of online aftercare programs, this study adapted the concept of internet-based minimal interventions in order to use the time between referral and actual admission to inpatient treatment. The online intervention includes information about the hospital and the treatment and sections which aim to enhance motivation, provide support and allow contact.

Methods

A comprehensive cohort study was conducted with 379 participants in the randomized subcohort. Primary endpoint was the speed of change of the physical, mental and social impairment and of the psychological well-being in the first 2 weeks of inpatient treatment as well as the rates of reliable change 2 weeks after admission.

Results

Both the control and intervention group of the randomized subcohort showed statistically significant improvements in health status. No significant difference in the rate of change was found. The degree of achieved improvement in the physical impairment was equal to the expected intervention effect. A difference in the rates of change was found for the psychological well-being: the intervention group showed 19% more reliable improvements.

Conclusions

The study design and the contents of the intervention were accepted by the patients. The internet-based intervention can help to prepare for treatment and to shorten the settling-in period.     

Category priming with aliens: analysing the influence of targets' prototypicality on the centre surround inhibition mechanism

Marginally perceptible prototypes as primes lead to slowed reactions to related category exemplars as compared to unrelated ones. This at first glance counterintuitive finding has been interpreted as evidence for a particular mechanism of lateral inhibition, namely the centre surround inhibition mechanism. We investigated the semantic surround of category labels by experimentally manipulating the prototypicality of stimuli. Participants first learned two new categories of fantasy creatures in a 5-day-long learning phase before they worked through a semantic priming task with the category prototypes as primes and category exemplars as targets. For high-prototypical targets we observed benefit effects from related primes, whereas for low-prototypical targets we observed cost effects. The results define when the centre surround inhibition mechanism is applied, and furthermore might explain why previous studies with word stimuli (i.e., material that prevents experimental manipulation of prototypicality) observed mixed results concerning the prototypicality of targets.