Response specific temporal expectancy: Evidence from a variable foreperiod paradigm

When a stimulus-response event is frequently paired with a specific foreperiod, response performance for this event is improved after this foreperiod. This phenomenon is referred to as specific temporal expectancy. In four experiments, we investigated whether stimulus- or response-related processing benefits from specific temporal expectancy. In a speeded choice reaction task, different features of the imperative stimuli were frequently paired with foreperiods in such a way that only in some experiments were the responses also frequently paired with foreperiods. Participants revealed evidence for specific temporal expectancy when responses were frequently paired with foreperiods, but not when only the stimuli were frequently paired with foreperiods. We concluded that specific temporal expectancy affects response-related processing.     

Eye vergence is susceptible to the hollow-face illusion

When an observer looks at a hollow mask of a face, a normal convex face is often perceived [the hollow-face illusion--Gregory 1973, in Illusion in Nature and Art (London: Duckworth) pp 49-96]. We show that in exploring an illusory face, the eyes converge at the illusory and not at the real distances of fixated targets like the tip of the nose. The 'vergence error' appears even though the resulting disparities of the two retinal images of the target provide feedback that would allow an immediate correction. It is presumably the success of recognising a familiar object (a face) which overrides the correction of convergence. This suggests that the brain strives for a congruency of eye vergence and distance perception.     

THE MODAL ARGUMENT FOR A PRIORI JUSTIFICATION

Kant famously argued that, from experience, we can only learn how something actually is, but not that it must be so. In this paper, I defend an improved version of Kant's argument for the existence of a priori knowledge, the Modal Argument , against recent objections by Casullo and Kitcher. For the sake of the argument, I concede Casullo's claim that we may know certain counterfactuals in an empirical way and thereby gain epistemic access to some nearby, nomologically possible worlds. But I maintain that our beliefs about metaphysical necessities still cannot be justified empirically. Furthermore, I reject Casullo's deflationary thesis about the significance of such justification. Kitcher's most troublesome objection is that we can gain any modal justification whatsoever through testimony , i.e. in an experiential way. This can be countered by distinguishing between productive sources of justification, like perception, and merely reproductive sources, like testimony. Thus, some productive a priori source will always be needed somewhere. ¹     

Behavioral and physiological responses of young horses to different weaning protocols: a pilot study

In this study, effects of weaning on behavioral and physiological stress parameters in young horses (foals) were determined. Foals were weaned either simultaneously without the presence of adult horses (group A, n?=?6), or in the presence of two adult females familiar but unrelated to the foals (group B, n?=?5), or weaned consecutively by removing two mother horses per day (group C, n?=?6). Behavior, locomotion, salivary cortisol concentration, beat-to-beat (RR) interval, heart rate variability (HRV) and weight were determined. Group A foals lost weight for 2 days (mean?±?SEM) -?8.3?±?1.6?kg, p?相似文献   

Evidence for task-specific resolution of response conflict

When a target requires different responses to a relevant and to an irrelevant task in a task-switching paradigm, there is response conflict. This target-induced response conflict was combined with conflict caused by a subliminally presented prime presented prior to the target. We found that target-related conflict reduced prime-induced conflict effects within the same trial. However, target-related conflict modified prime-related conflict effects according to the irrelevant stimulus-response (S-R) rule, but not according to the relevant S-R rule. Moreover, trial-to-trial modulations of the target congruency effect were observed in task repetition trials, but not in task switch trials. These results indicate that conflict resolution mechanisms, at least under the present circumstances, operate in a strictly task-specific manner.     

The assessment of self-oriented and socially prescribed perfectionism: subscales make a difference

Campbell and Di Paula (2002) suggested differentiating Perfectionistic Striving and Importance of Being Perfect subscales when measuring self-oriented perfectionism and Others' High Standards and Conditional Acceptance subscales when measuring socially prescribed perfectionism. In this study, we investigated the utility of this differentiation by analyzing data from 1,041 students and examining correlations with positive striving and maladaptive evaluation concerns aspects of perfectionism and with positive and negative indicators of well-being and psychological adjustment. As expected, (a) Perfectionistic Striving scores showed higher correlations with positive striving aspects of perfectionism and with positive indicators of well-being and adjustment than Importance of Being Perfect scores, and (b) Conditional Acceptance scores showed higher correlations with maladaptive evaluation concerns aspects of perfectionism and with negative indicators of well-being and adjustment than Others' High Standards scores. The findings indicate that Campbell and Di Paula's differentiation provides for a more detailed and informative assessment of multidimensional perfectionism and its different aspects. Moreover, it provides for new insights into self-oriented and socially prescribed perfectionism and their relationships and associations.     

On the development of perfectionism in adolescence: Perceived parental expectations predict longitudinal increases in socially prescribed perfectionism

Adolescence is regarded a key period when individual differences in perfectionism develop. Yet, so far only a few longitudinal studies have investigated the development of perfectionism in adolescents. Using a longitudinal correlational design with 381 adolescents aged 15–19 years, the present study investigated whether perceived parental expectations and criticism predicted longitudinal increases in self-oriented and socially prescribed perfectionism over 7–9 months. Results showed that perceived parental expectations predicted longitudinal increases in socially prescribed perfectionism: Adolescents who perceived that their parents had high expectations of them at Time 1, showed increased socially prescribed perfectionism from Time 1 to Time 2 compared to adolescents who did not perceive their parents having such high expectations. No such effect was found for self-oriented perfectionism. The findings provide supportive evidence for the social expectations model of the development of perfectionism regarding socially prescribed perfectionism, but not self-oriented perfectionism. Implications of this finding for the understanding of the development of perfectionism and future studies are discussed.     

Twilight of a Dilemma: A Réplique

In light of the nine open peer commentaries, we further explicate the social projection model and highlight its boundaries. We acknowledge that our model—like any extant model—cannot account for all the available empirical data. Yet the model is strong because it explains cooperation in a variety of social dilemmas and experimental games while deploying only one psychological construct as a parameter. Compared with its competitors, the social projection model more openly recognizes the struggle with uncertainty a person caught in a social dilemma must confront. In a series of simulations (and brute math), we show that cooperation can survive when players (humans) stay the Bayesian course.     

Voluntary Engagement in an Open Web-Based Encyclopedia: Wikipedians and Why They Do It

The online encyclopedia Wikipedia is a highly successful “open content” project, written and maintained completely by volunteers. Little is known, however, about the motivation of these volunteers. Results from an online survey among 106 contributors to the German Wikipedia project are presented. Both motives derived from social sciences (perceived benefits, identification with Wikipedia, etc.) as well as perceived task characteristics (autonomy, skill variety, etc.) were assessed as potential predictors of contributors' satisfaction and self-reported engagement. Satisfaction ratings were particularly determined by perceived benefits, identification with the Wikipedia community, and task characteristics. Engagement was particularly determined by high tolerance for opportunity costs and by task characteristics, the latter effect being partially mediated by intrinsic motivation. Relevant task characteristics for contributors' engagement and satisfaction were perceived autonomy, task significance, skill variety, and feedback. Models from social sciences and work psychology complemented each other by suggesting that favorable task experiences might counter perceived opportunity costs in Wikipedia contributors. Moreover, additional data reported by Wikipedia authors indicate the importance of generativity motives.