Hermann Weyl on Minkowskian Space–Time and Riemannian Geometry

Hermann Weyl as a founding father of field theory in relativistic physics and quantum theory always stressed the internal logic of mathematical and physical theories. In line with his stance in the foundations of mathematics, Weyl advocated a constructivist approach in physics and geometry. An attempt is made here to present a unified picture of Weyl’s conception of space–time theories from Riemann to Minkowski. The emphasis is on the mathematical foundations of physics and the foundational significance of a constructivist philosophical point of view. I conclude with some remarks on Weyl’s broader philosophical views.     

Race-specific perceptual discrimination improvement following short individuation training with faces

This study explores the effect of individuation training on the acquisition of race-specific expertise. First, we investigated whether practice individuating other-race faces yields improvement in perceptual discrimination for novel faces of that race. Second, we asked whether there was similar improvement for novel faces of a different race for which participants received equal practice, but in an orthogonal task that did not require individuation. Caucasian participants were trained to individuate faces of one race (African American or Hispanic) and to make difficult eye-luminance judgments on faces of the other race. By equating these tasks we are able to rule out raw experience, visual attention, or performance/success-induced positivity as the critical factors that produce race-specific improvements. These results indicate that individuation practice is one mechanism through which cognitive, perceptual, and/or social processes promote growth of the own-race face recognition advantage.     

Does temporal integration of face parts reflect holistic processing?

We examined whether temporal integration of face parts reflects holistic processing or response interference. Participants learned to name two faces “Fred” and two “Bob.” At test, the top and bottom halves of different faces formed composites and were presented briefly separated in time. Replicating prior findings (Singer & Sheinberg, Vision Research, 46, 1838–1847, 2006), naming of the target half for aligned composites was slowed when the irrelevant half was from a face with a different name rather than from the original face. However, no interference was observed when the irrelevant half had a name identical to the name of the target half but came from a different learned face, arguing against a true holistic effect. Instead, response interference was obtained when the target half briefly preceded the irrelevant half. Experiment 2 confirmed a double dissociation of holistic processing versus response interference for intact faces versus temporally separated face halves, suggesting that simultaneous presentation of facial information is critical for holistic processing.     

The foundation of research ethics in community law

The creation of the European Community by the Treaty of Rome in 1957 marked the beginning of the efforts to coordinate and harmonize national policies in many strategic sectors with high economic value, among them several aspects of scientific research. The European Union Law, formerly known as European Community law, now includes a range of ethical principles that apply to research projects developed with the financial support of the European Union. Which were the steps in the integration of the ethics of sciences in the context of the Union? This article aims to study first, what were, and what are the legal bases of the integration of the ethical dimension of researches in life sciences by the European Union and, secondly, the institutional organisation that has been set up in order to discuss the development of common ethical norms, especially bioethics one, and in order to apply these rules which respect national particularities. In this regard, we analyse the relevant legal texts providing a foundation for the creation of a European bio-law and we give an overview of the European institutions' activity in the field of bioethics by looking particularly the health research field.     

Limits of generalization between categories and implications for theories of category specificity

Both domain-specific and expertise accounts of category specialization assume that generalization occurs within a domain but not between domains. Yet it is often difficult to define the boundaries and critical features of object domains. Differences in how categories are defined make it difficult to adjudicate between accounts of category specificity and may lead to contradictory results. For example, evidence for whether car experts recruit the fusiform face area is mixed, and this inconsistency may be due to the inclusion of antique cars in one of those previous studies (e.g., Grill-Spector, Knouf, & Kanwisher, 2004). The present study tested the generalization of expertise from modern to antique cars and found that modern-car experts showed expert discrimination and holistic processing of modern cars but not of antique cars. These findings suggest that the neural specialization underlying perceptual expertise is highly specific and may not generalize to distinct subclasses, even when they share some degree of perceptual and conceptual features.     

Should we reject the expertise hypothesis?

On the basis of a review of the literature and the results of three experiments with dog experts, Robbins and McKone [Robbins, R. A., & McKone, E. (2006). No face-like processing for objects-of-expertise in three behavioural tasks, Cognition] argue that there is little or no evidence supporting an expertise account of the differences in configural processing that are typically observed between faces and non-face objects. In the spirit of a debate that has become overly polarized, we believe that R&M often emphasized relatively unimportant controversial issues at the expense of bigger, more important questions. We also feel that some of R&M's arguments are rooted in methodological confusions that should be clarified because they have implications beyond this specific debate. In this commentary, we first clarify issues surrounding the proper statistical analysis of the composite paradigm, a methodology that is commonly used to assess configural and holistic effects in both face and non-face objects. We then discuss several theoretical issues that we feel are central to the debate regarding accounts of face-specificity. We also briefly review positive evidence for the correlation between measures of behavioral expertise and neural markers of face-selectivity. Unlike R&M, we believe the positive evidence for expertise effects, both behavioral and neural, greatly outweighs evidence stemming from null results and that it clearly motivates the importance of future work on the role of experience in the specialization of visual cortex.     

A visual short-term memory advantage for faces

What determines how much can be stored in visual short-term memory (VSTM)? Studies of VSTM have focused largely on stimulus-based properties such as the number or complexity of the items stored. Recent work also suggests that capacity is severely reduced for items within the same category. However, the importance for VSTM capacity of more qualitative differences in processing for different categories has not been investigated. For example, faces are processed more holistically than other objects. In Experiments 1 and 2, we show that the processing of faces, objects that are crucial socially and for which we possess considerable expertise, overcomes these limitations. More faces can be stored in VSTM than objects from other complex nonface categories. As in prior studies, at short encoding durations we found that capacity for faces was less than that for other categories. However, at longer encoding durations, capacity for faces exceeded that for nonface objects, and this advantage was specific to upright faces. Because inversion reduces holistic processing, the interaction of orientation with VSTM capacity—which occurred for faces but not objects in Experiment 3—suggests that it is holistic processing that confers an advantage for face VSTM when sufficient encoding time is allowed.     

The assessment of recognition memory using the Remember/Know procedure in amnestic mild cognitive impairment and probable Alzheimer’s disease

This study used the Remember/Know (R/K) procedure combined with signal detection analyses to assess recognition memory in 20 elders with amnestic mild cognitive impairment (aMCI), 10 patients with probable Alzheimer’s disease (AD) as well as matched healthy older adults. Signal detection analyses first indicated that aMCI and control participants were comparable on general recognition performance. As regards AD patients, they were impaired relative to both aMCI and healthy elders. When assessing Remember and Know responses the aMCI group showed diminished sensitivity for Remember responses but intact Know responses compared to healthy elders. In contrast, AD patients showed decreased sensitivity for both Remember and Know responses compared to control and aMCI participants. The response bias index revealed that AD patients were more liberal than aMCI and control participants when providing Know responses. On the other measures, response bias was comparable between the groups. Overall, this study indicates that the R/K procedure can characterize different aspects of recognition memory performance in persons with aMCI or AD.     

Ethics Issues with Private Research Ethics Boards: A Breakout Session at the 2009 NCEHR National Conference

Research Ethics Boards (REBs) provide oversight for Canadians that research projects will comply with standards of ethics if the studies are carried out as described in the documents that have been approved. While REBs have traditionally been affiliated with institutions such as universities and hospitals, a number of factors - including the increased volume of research being conducted outside academic centres - have resulted in the establishment of some private or independent REBs. This, in turn, has raised concerns about the credibility of REBs in the private sector and their capacity to handle issues around conflict of interest. This Breakout Session was an opportunity to hear the perspectives of people associated with institutional and private REBs and examine perceived problems with boards in the private sector, scrutinize theoretical and structural differences between types of REBs, and look at whether or not there is room for both institutional and private boards in the Canadian research review landscape.