Learning influences the encoding of static and dynamic faces and their recognition across different spatial frequencies

Studies on face recognition have shown that observers are faster and more accurate at recognizing faces learned from dynamic sequences than those learned from static snapshots. Here, we investigated whether different learning procedures mediate the advantage for dynamic faces across different spatial frequencies. Observers learned two faces—one dynamic and one static—either in depth (Experiment 1) or using a more superficial learning procedure (Experiment 2). They had to search for the target faces in a subsequent visual search task. We used high-spatial frequency (HSF) and low-spatial frequency (LSF) filtered static faces during visual search to investigate whether the behavioural difference is based on encoding of different visual information for dynamically and statically learned faces. Such encoding differences may mediate the recognition of target faces in different spatial frequencies, as HSF may mediate featural face processing whereas LSF mediates configural processing. Our results show that the nature of the learning procedure alters how observers encode dynamic and static faces, and how they recognize those learned faces across different spatial frequencies. That is, these results point to a flexible usage of spatial frequencies tuned to the recognition task.     

Similarity and categorization: from vision to touch

Even though human perceptual development relies on combining multiple modalities, most categorization studies so far have focused on the visual modality. To better understand the mechanisms underlying multisensory categorization, we analyzed visual and haptic perceptual spaces and compared them with human categorization behavior. As stimuli we used a three-dimensional object space of complex, parametrically-defined objects. First, we gathered similarity ratings for all objects and analyzed the perceptual spaces of both modalities using multidimensional scaling analysis. Next, we performed three different categorization tasks which are representative of every-day learning scenarios: in a fully unconstrained task, objects were freely categorized, in a semi-constrained task, exactly three groups had to be created, whereas in a constrained task, participants received three prototype objects and had to assign all other objects accordingly. We found that the haptic modality was on par with the visual modality both in recovering the topology of the physical space and in solving the categorization tasks. We also found that within-category similarity was consistently higher than across-category similarity for all categorization tasks and thus show how perceptual spaces based on similarity can explain visual and haptic object categorization. Our results suggest that both modalities employ similar processes in forming categories of complex objects.     

Loving without understanding: Raimon Panikkar’s ontological pluralism

Raimon Panikkar is one of the most sophisticated and most profound among contemporary pluralists of religion. His pluralism is radical because it is rooted in the very nature of things, in the pluralism of being itself, beyond all perspectivalism and indeed beyond truth and falsity taken as intellectual categories. I discuss several issues regarding his position. Is he indeed a pluralist or a monist in disguise? Does he do justice to the uniqueness of each religion? Is he not prematurely introducing the eschatological ideal of the harmony of opposites into the historical world where opposites often produce bloody conflicts?     

Naming the Unnameable God: Levinas, Derrida, and Marion

In this essay I present the postmodern phenomenological approach of Levinas, Derrida, and Marion to the problem of naming the unnameable God. For Levinas, God is never experienced directly but only as a third person whose infinity is testified to in the infinity of responsibility to the hungry. For Derrida, God remains the unnameable “wholly other” accessible only as the indeterminate term of pure reference in prayer. For Marion, God remains the object of “de-nomination” through praise. In all three, the problem of naming the unnameable God is necessarily linked to how we relate to fellow human beings, to the hungry in Levinas, justice in Derrida, and charity in Marion. I also reflect on the merits and adequacy of phenomenology as such for speaking of divine transcendence.     

Diamonds are a Philosopher's Best Friends

The knowability paradox is an instance of a remarkable reasoning pattern (actually, a pair of such patterns), in the course of which an occurrence of the possibility operator, the diamond, disappears. In the present paper, it is pointed out how the unwanted disappearance of the diamond may be escaped. The emphasis is not laid on a discussion of the contentious premise of the knowability paradox, namely that all truths are possibly known, but on how from this assumption the conclusion is derived that all truths are, in fact, known. Nevertheless, the solution offered is in the spirit of the constructivist attitude usually maintained by defenders of the anti-realist premise. In order to avoid the paradoxical reasoning, a paraconsistent constructive relevant modal epistemic logic with strong negation is defined semantically. The system is axiomatized and shown to be complete.