Illusory own body perceptions: Case reports and relevance for bodily self-consciousness

Neurological disorders of body representation have for a long time suggested the importance of multisensory processing of bodily signals for self-consciousness. One such group of disorders – illusory own body perceptions affecting the entire body – has been proposed to be especially relevant in this respect, based on neurological data as well as philosophical considerations. This has recently been tested experimentally in healthy subjects showing that integration of multisensory bodily signals from the entire body with respect to the three aspects: self-location, first-person perspective, and self-location, is crucial for bodily self-consciousness. Here we present clinical and neuroanatomical data of two neurological patients with paroxysmal disorders of full body representation in whom only one of these aspects, self-identification, was abnormal. We distinguish such disorders of global body representation from related but distinct disorders and discuss their relevance for the neurobiology of bodily self-consciousness.     

Viewer perspective affects central bottleneck requirements in spatial translation tasks

A psychological refractory period (PRP) approach and the locus of slack logic were applied to examine the novel question of whether spatial translation processes can begin before the central bottleneck when effector or noneffector stimuli are processed from an egocentric (viewer-centered) perspective. In single tasks, trials requiring spatial translations were considerably slower than trials without translations (Experiment 1). Dual tasks consisted of tone discriminations (Task 1) and spatial translations (Task 2) using PRP methods with different manipulations on perceptual and response demands. When a viewer-centered perspective was used, the effect of spatial translation was reduced at short compared with long stimulus onset asynchronies (SOAs) when the potential for code overlap between tasks was removed (Experiments 2, 3, and 4); this finding supports the view that translation processes can begin before the central bottleneck. When an allocentric (non-viewer-centered) perspective was used (Experiment 5), the slowing associated with spatial translation was additive with SOA, suggesting that the processes of spatial translation cannot begin before the bottleneck. These findings highlight the importance of viewer perspective on central bottleneck requirements. Findings are further discussed in relation to the dorsal-ventral model of action and perception.     

A Certain Kind of Trinity: Dependence, Substance, Explanation

The main contribution of this paper is a novel account of ontological dependence. While dependence is often explained in terms of modality and existence, there are relations of dependence that slip through the mesh of such an account. Starting from an idea proposed by Jonathan Lowe, the article develops an account of ontological dependence based on a notion of explanation; on its basis, certain relations of dependence can be established that cannot be accounted by the modal-existential account. Dependence is only one of two main topics of this paper, for it is approached via a discussion of the category of substance. On a traditional view, substances can be characterised as independent entities. Before the background of a modal-existential account of dependence, this idea appears problematic. The proposed notion of explanatory dependence is shown to vindicate the traditional approach to substance.     

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.     

On believing indirectly for practical reasons

Philosophical Studies - It is often argued that there are no practical reasons for belief because we could not believe for such reasons. A recent reply by pragmatists is that we can often believe...     

Studienbezogene Belastungen, Lebensqualität und Beziehungserleben bei Medizinstudenten

In a cross-sectional study of medical students we examined educational strains, health feeling, and relationship patterns. Work stress was measured using the questionnaire by Jurkat et al., health-related quality of life was measured using the Short Form- (SF-)36 Health Survey, and relationship patterns to the partner as well as to a friend were mapped using“Beziehungsmusterfragebogen“ (BeMus). Study stress was assessed as being high by 60% of the students. Consequently, 39% had not enough time for their partners und 29% had no time for own interests. The mental health averaged significantly below the norm. A high workload and discontent correlated with aggressiveness, especially in the partnership, whereas loving care towards the partner or friend correlated with a high level of satisfaction and a lower strain level. Therefore, an improvement of psychosocial competence in medical students as well as a practice-oriented preparation for the profession is needed.     

Factors affecting conscious awareness in the recollective experience of adults with Asperger's syndrome

have shown a small but significant impairment of autonoetic awareness or remembering involved in the episodic memory experiences of adults with Asperger's syndrome. This was compensated by an increase in experiences of noetic awareness or knowing. The question remains as to whether the residual autonoetic awareness in Asperger individuals is qualitatively the same as that of typical comparison participants. Three experiments are presented in which manipulations that have shown differential effects on different kinds of conscious awareness in memory in typical populations are employed with a sample of adults with Asperger's syndrome. The results suggest that the experiences of remembering reported by such individuals, although reduced in quantity, are qualitatively similar to those seen in the typical population. The results are discussed in the context of current theories of awareness in episodic memory.     

The effects of switching between targets on the performance of a simple motor skill

Little direct evidence has emerged regarding the influence of switching between tasks on the performance of skills studied in the motor domain. The present study reported the results of two experiments that examined the effects of task switching on a simple object projection task, which presumably emphasized processes related to response planning and execution. The experimental task required participants to gently tap a knob to make it travel along two parallel rods until it reached a specified target distance. In both experiments, participants in the repeated conditions performed a single target distance while participants in the switched conditions alternated between two target distances. Results indicated that switching between targets degraded accuracy for the two short targets (30cm, Exp. 1; 20cm, Exp. 2). Results were consistent with the preservation of parameter values [Rosenbaum, D. A., Weber, R. J., Hazelett, W. M., & Hindorff, V. (1986). The parameter remapping effect in human performance. Evidence form tongue twisters and finger fumblers. Journal of Memory and Language, 25, 710-725; Sherwood, D. E. (2007). Separate movement planning and spatial assimilation effects in sequential bimanual aiming movements. Perceptual and Motor Skills, 105, 501-513] and suggested an additional role for persisting activation in accounting for spatial assimilation and magnitude effects.     

Theory‐Driven Subgroup‐Specific Evaluation of an Intervention to Reduce Private Car Use1

In the context of a 2‐wave panel study, we used Ajzen's (1991) theory of planned behavior (TPB) as the theoretical framework for deriving and systematically testing hypotheses as to how an intervention (a “free” ticket for public transportation) influences the travelmode choice of students. The empirical results show that this intervention caused a drastic decrease in students' car use. The effect of the intervention on behavior is mediated by the causal chain postulated by the TPB. In the second step, we analyzed whether there were subgroup‐specific reactions to the intervention. Surprisingly, the subgroup analysis shows that students with more negative attitudes toward policy measures restricting car use reacted more strongly to the intervention than did students with a more positive attitude.