Virtual reality: A new track in psychological research

One major challenge of social interaction research is to achieve high experimental control over social interactions to allow for rigorous scientific reasoning. Virtual reality (VR) promises this level of control. Pan and Hamilton guide us with a detailed review on existing and future possibilities and challenges of using VR for social interaction research. Here, we extend the discussion to methodological and practical implications when using VR.     

Asymmetric cost and benefit perceptions in willingness-to-donate decisions

Charitable giving entails the act of foregoing personal resources in order to improve the conditions of other people. In the present paper, we systematically examine two dimensions integral to donation decisions that have thus far received relatively little attention but can explain charitable behavior rather well: the perceptions of cost for the donor and benefit for the recipients. In line with current theories in judgment and decision making, we hypothesize that people weigh these dimensions subjectively and perceive them asymmetrically, consistent with prospect theory. Costs for the donor are typically perceived as losses, whereas benefits for recipients are perceived as gains. In four studies, we presented several scenarios to participants in which both donation amounts (costs) and number of lives helped (benefits) were manipulated while keeping the ratio of costs and benefits constant. Results from Studies 1 and 2 showed that willingness to help decreased as donation amounts and number of lives helped increased. Additionally, Studies 3 and 4 provide evidence for a solution to reduce the asymmetry and increase donation amounts as the number of lives at risk increases.     

Why Higher Working Memory Capacity May Help You Learn: Sampling,Search, and Degrees of Approximation

Algorithms for approximate Bayesian inference, such as those based on sampling (i.e., Monte Carlo methods), provide a natural source of models of how people may deal with uncertainty with limited cognitive resources. Here, we consider the idea that individual differences in working memory capacity (WMC) may be usefully modeled in terms of the number of samples, or “particles,” available to perform inference. To test this idea, we focus on two recent experiments that report positive associations between WMC and two distinct aspects of categorization performance: the ability to learn novel categories, and the ability to switch between different categorization strategies (“knowledge restructuring”). In favor of the idea of modeling WMC as a number of particles, we show that a single model can reproduce both experimental results by varying the number of particles—increasing the number of particles leads to both faster category learning and improved strategy‐switching. Furthermore, when we fit the model to individual participants, we found a positive association between WMC and best‐fit number of particles for strategy switching. However, no association between WMC and best‐fit number of particles was found for category learning. These results are discussed in the context of the general challenge of disentangling the contributions of different potential sources of behavioral variability.     

Withdrawing attention at little or no cost: Detection and discrimination tasks

We used a concurrent-task paradigm to investigate the attentional cost of simple visual tasks. As in earlier studies, we found that detecting a unique orientation in an array of oriented elements (“pop-out”) carries little or no attentional cost. Surprisingly, this is true at all levels of performance and holds even when pop-out is barely discriminable. We discuss this finding in the context of our previous report that the attentional cost of stimulus detection is strongly influenced by the presence and nature of other stimuli in the display (Braun, 1994b). For discrimination tasks, we obtained a similarly mixed outcome: Discrimination of letter shape carried a high attentional cost whereas discrimination of color and orientation did not. Taken together, these findings lead us to modify our earlier position on the attentional costs of detection and discrimination tasks (Sagi & Julesz, 1985). We now believe that observers enjoy a significant degree of “ambient” visual awareness outside the focus of attention, permitting them to both detect and discriminate certain visual information. We hypothesize that the information in question is selected by a competition for saliency at the level of early vision.     

Visual attention and perceptual grouping.

Perceptual organization is thought to involve an analysis of both textural discontinuities and perceptual grouping. In earlier work, we found that textural discontinuities were detected normally even when visual attention was engaged elsewhere. Here we report how perceptual grouping is affected when visual attention is engaged by a concurrent visual task. To elicit perceptual grouping, we used the Gestalt demonstrations of grouping on the basis of proximity and of similarity. Four tasks were investigated, some requiring the observer to discriminate between horizontal and vertical grouping, and some requiring the observer to merely detect the presence or absence of grouping. Visual attention was engaged at the center of the display by a form identification task. The detection of a textural discontinuity served as a control task. Concurrent form identification conflicted with all four grouping tasks, resulting in a significant reduction of grouping performance in each case. No performance reduction was observed when either form identification or grouping discrimination was combined with the detection of a textural discontinuity. These results suggest that perceptual grouping and form identification compete for visual attention, whereas the detection of a textural discontinuity does not.     

On Brentano's objections to Kant's theory of knowledge

The main purpose of this essay is to examine Brentano's rejection of Kant's theory of a priori concepts and synthetic a priori judgments. The essay begins by recalling the views of Descartes and Locke about the acquisition of knowledge, since Brentano regards them as on the whole correct or, at least, as pointing in the right direction and since he regards Kant's epistemology as obscurantist and reactionary (Section 1). There follows a brief characterization of Brentano's conception of knowledge as based on self-evident inner perception and analytic propositions, i.e. propositions which are true ex terminis (Section 2). Next some aspects of Kant's epistemology are compared with corresponding features of Brentano's doctrine (Section 3). In the light of this comparison the validity of Brentano's criticisms is examined (Section 4). In conclusion an independent view of the function of concepts and of their relation to perception is briefly outlined and contrasted with the views of Kant and Brentano (Section 5).