Evidence for view-invariant Face Recognition Units in unfamiliar face learning

Many models of face recognition incorporate the idea of a face recognition unit (FRU). This is an abstracted representation formed from each experience of a face. Longmore et al. (2008) devised a face learning experiment to investigate such a construct (i.e., view-invariance) but failed to find evidence of its existence. Three experiments developed Longmore et al.’s study further by using a different learning task, by employing more stimuli. One or two views of previously unfamiliar faces were shown to participants in a serial matching task (learning). Later, participants attempted to recognise both seen and novel views of the learned faces. Experiment one tested participants’ recognition of a novel view, a day after learning. Experiment two was identical, but tested participants on the same day as learning. And experiment three repeated experiment one, but tested participants on a novel view that was outside the rotation of those views learned. Results revealed a significant advantage for recognising a novel view when two views had been learned, rather than a single learned view – for all experiments. The effect of view-invariance found when both views were learned is discussed

Anisotropy and universality: Critical Binder cumulant of the two-dimensional Ising model

We reanalyze transfer matrix and Monte Carlo results for the critical Binder cumulant U* of an anisotropic two-dimensional Ising model on a square lattice in a square geometry with periodic boundary conditions. Spins are coupled between nearest neighboring sites and between next-nearest neighboring sites along one of the lattice diagonals. We find that U* depends only on the asymptotic critical long-distance features of the anisotropy, irrespective of its realization through ferromagnetic or antiferromagnetic next-nearest neighbor couplings. We modify an earlier renormalization-group calculation to obtain a quantitative description of the anisotropy dependence of U*. Our results support our recent claim towards the validity of universality for critical phenomena in the presence of a weak anisotropy.Comment: 4 pages, 2 figures; one reference and some clarifications adde

Elliptic instability in the Lagrangian-averaged Euler-Boussinesq-alpha equations

We examine the effects of turbulence on elliptic instability of rotating stratified incompressible flows, in the context of the Lagragian-averaged Euler-Boussinesq-alpha, or \laeba, model of turbulence. We find that the \laeba model alters the instability in a variety of ways for fixed Rossby number and Brunt-V\"ais\"al\"a frequency. First, it alters the location of the instability domains in the $(\gamma,\cos\theta)-$parameter plane, where $\theta$ is the angle of incidence the Kelvin wave makes with the axis of rotation and $\gamma$ is the eccentricity of the elliptic flow, as well as the size of the associated Lyapunov exponent. Second, the model shrinks the width of one instability band while simultaneously increasing another. Third, the model introduces bands of unstable eccentric flows when the Kelvin wave is two-dimensional. We introduce two similarity variables--one is a ratio of the Brunt-V\"ais\"al\"a frequency to the model parameter $\Upsilon_0 = 1+\alpha^2\beta^2$, and the other is the ratio of the adjusted inverse Rossby number to the same model parameter. Here, $\alpha$ is the turbulence correlation length, and $\beta$ is the Kelvin wave number. We show that by adjusting the Rossby number and Brunt-V\"ais\"al\"a frequency so that the similarity variables remain constant for a given value of $\Upsilon_0$, turbulence has little effect on elliptic instability for small eccentricities $(\gamma \ll 1)$. For moderate and large eccentricities, however, we see drastic changes of the unstable Arnold tongues due to the \laeba model.Comment: 23 pages (sigle spaced w/figure at the end), 9 figures--coarse quality, accepted by Phys. Fluid

Inversion improves the recognition of facial expression in thatcherized images

The Thatcher illusion provides a compelling example of the face inversion effect. However, the marked effect of inversion in the Thatcher illusion contrasts to other studies that report only a small effect of inversion on the recognition of facial expressions. To address this discrepancy, we compared the effects of inversion and thatcherization on the recognition of facial expressions. We found that inversion of normal faces caused only a small reduction in the recognition of facial expressions. In contrast, local inversion of facial features in upright thatcherized faces resulted in a much larger reduction in the recognition of facial expressions. Paradoxically, inversion of thatcherized faces caused a relative increase in the recognition of facial expressions. Together, these results suggest that different processes explain the effects of inversion on the recognition of facial expressions and on the perception of the Thatcher illusion. The grotesque perception of thatcherized images is based on a more orientation-sensitive representation of the face. In contrast, the recognition of facial expression is dependent on a more orientation-insensitive representation. A similar pattern of results was evident when only the mouth or eye region was visible. These findings demonstrate that a key component of the Thatcher illusion is to be found in orientation-specific encoding of the features of the face

Tree species and moisture effects on soil sources of N2O: Quantifying contributions from nitrification and denitrification with O-18 isotopes

Nitrous oxide (N2O) is an important greenhouse gas and participates in the destruction of stratospheric ozone. Soil bacteria produce N2O through denitrification and nitrification, but these processes differ radically in substrate requirements and responses to the environment. Understanding the controls over N2O efflux from soils, and how N2O emissions may change with climate warming and altered precipitation, require quantifying the relative contributions from these groups of soil bacteria to the total N2O flux. Here we used ammonium nitrate (NH4NO3, including substrates for both processes) in which the nitrate has been enriched in the stable isotope of oxygen, O-18, to partition microbial sources of N2O, arguing that a molecule of N2O carrying the O-18 labeled will have been produced by denitrification. We compared the influences of six common tree species on the relative contributions of nitrification and denitrification to N2O flux from soils, using soils from the Siberian afforestation experiment. We also altered soil water content, to test whether denitrification becomes a dominant source of N2O when soil water content increases. Tree species altered the proportion of nitrifier and denitrifier-derived N2O. Wetter soils produced more N2O from denitrification, though the magnitude of this effect varied among tree species. This indicates that the roles of denitrification and nitrification vary with tree species, and, that tree species influence soil responses to increased water content

Stable isotope discrimination during soil denitrification: Production and consumption of nitrous oxide

Measuring the stable isotope composition of nitrous oxide ( N(2)O) evolved from soil could improve our understanding of the relative contributions of the main microbial processes ( nitrification and denitrification) responsible for N(2)O formation in soil. However, interpretation of the isotopic data in N(2)O is complicated by the lack of knowledge of fractionation parameters by different microbial processes responsible for N(2)O production and consumption. Here we report isotopic enrichment for both nitrogen and oxygen isotopes in two stages of denitrification, N(2)O production and N(2)O reduction. We found that during both N(2)O production and reduction, enrichments were higher for oxygen than nitrogen. For both elements, enrichments were larger for N(2)O production stage than for N(2)O reduction. During gross N(2)O production, the ratio of delta(18)O- to-delta(15)N differed between soils, ranging from 1.6 to 2.7. By contrast, during N(2)O reduction, we observed a constant ratio of delta(18)O- to-delta(15)N with a value near 2.5. If general, this ratio could be used to estimate the proportion of N(2)O being reduced in the soil before escaping into the atmosphere. Because N(2)O- reductase enriches N(2)O in both isotopes, the global reduction of N(2)O consumption by soil may contribute to the globally observed isotopic depletion of atmospheric N(2)O

Some Aspects of Leadership in Independent Schools in Alberta

Interest in independent schools has been growing in Canada, partly as a result of some parental dissatisfaction with public schools. The Canadian province of Alberta has legislation in place that permits development of independent schools while simultaneously imposing controls on their operations. A recent study used interviews, observations, and documents to examine the perceptions of principals in eight accredited, funded, independent schools in Alberta about the major factors that affected their leadership role. They especially identified philosophical congruence enhanced by respect and trust, as well as personal relationships, school culture, symbolism, and support from staff of the government's regional offices.Au Canada, on manifeste de plus en plus d'intérêt dans les écoles indépendantes; il s'agit d'un phénomène qui est en partie dû à la l'insatisfaction que certains parents ressentent vis-à-vis des écoles publiques. Dans la province de l'Alberta (Canada), la législation actuelle permet l'établissement d'écoles indépendantes tout en imposant certains contrôles quant à leur fonctionnement. Les auteurs ont voulu identifier les perceptions de huit directeurs d'écoles indépendantes, reconnues et financées en Alberta quant aux principaux facteurs qui influaient sur leur rôle de leadership. Pour ce faire, ils ont eu recours aux entrevues, aux observations et à l'étude de documents. Les directeurs ont surtout évoqué la conformité philosophique assurée par le respect et la confiance, ainsi que les relations personnelles, la culture scolaire, le symbolisme et l'appui de la part du personnel des bureaux régionaux du gouvernement

Some Aspects of Leadership in Independent Schools in Alberta

Interest in independent schools has been growing in Canada, partly as a result of some parental dissatisfaction with public schools. The Canadian province of Alberta has legislation in place that permits development of independent schools while simultaneously imposing controls on their operations. A recent study used interviews, observations, and documents to examine the perceptions of principals in eight accredited, funded, independent schools in Alberta about the major factors that affected their leadership role. They especially identified philosophical congruence enhanced by respect and trust, as well as personal relationships, school culture, symbolism, and support from staff of the government's regional offices.Au Canada, on manifeste de plus en plus d'intérêt dans les écoles indépendantes; il s'agit d'un phénomène qui est en partie dû à la l'insatisfaction que certains parents ressentent vis-à-vis des écoles publiques. Dans la province de l'Alberta (Canada), la législation actuelle permet l'établissement d'écoles indépendantes tout en imposant certains contrôles quant à leur fonctionnement. Les auteurs ont voulu identifier les perceptions de huit directeurs d'écoles indépendantes, reconnues et financées en Alberta quant aux principaux facteurs qui influaient sur leur rôle de leadership. Pour ce faire, ils ont eu recours aux entrevues, aux observations et à l'étude de documents. Les directeurs ont surtout évoqué la conformité philosophique assurée par le respect et la confiance, ainsi que les relations personnelles, la culture scolaire, le symbolisme et l'appui de la part du personnel des bureaux régionaux du gouvernement