We present an investigation into the relation between design princi- ples in Japanese gardens, and their associated perceptual effects. This leads to the realization that a set of design principles described in a Japanese gardening text by Shingen (1466), shows many parallels to the visual effects of perceptual grouping, studied by the Gestalt school of psychology. Guidelines for composition of rock clusters closely relate to perception of visual figure. Garden design elements are arranged into patterns that simplify figure-ground segmentation, while (...) seemingly balancing the visual salience of subparts and the global arrangement. Visual ‘ground’ is analyzed via medial axis transformation (MAT), often associated with shape perception in humans. MAT analysis reveals implicit structure in the visual ground of a quintessential rock garden design. The MAT structure enables formal com- parison of structure of figure and ground. They share some aesthetic qualities, with interesting differences. Both contain naturalistic asymmetric, self-similar, branching structures. While the branching pattern of the ground converges towards the viewer, that of the figure converges in the opposite direction. (shrink)

We present an investigation into the relation between design principles in Japanese gardens, and their associated perceptual effects. This leads to the realization that a set of design principles described in a Japanese gardening text by Shingen (1466), shows many parallels to the visual effects of perceptual grouping, studied by the Gestalt school of psychology. Guidelines for composition of rock clusters closely relate to perception of visual figure. Garden design elements are arranged into patterns that simplify figure-ground segmentation, while seemingly (...) balancing the visual salience of subparts and the global arrangement. Visual ‘ground’ is analyzed via medial axis transformation (MAT), often associated with shape perception in humans. MAT analysis reveals implicit structure in the visual ground of a quintessential rock garden design. The MAT structure enables formal comparison of structure of figure and ground. They share some aesthetic qualities, with interesting differences. Both contain naturalistic asymmetric, self-similar, branching structures. While the branching pattern of the ground converges towards the viewer, that of the figure converges in the opposite direction. (shrink)

Reaction-diffusion systems which have reaction term satisfying f(-q) = -f(q) tend strongly to form striped patterns. Haken’s slaving principle is used to derive differential equations for unstable mode amplitudes close to the Turing instability. This connects a dynamical symmetry to pattern selection, with possible relevance to biological and chemical pattern-forming phenomena.

We present a technique for the analysis of pattern formation by a class of models for the formation of ocular dominance stripes in the striate cortex of some mammals. The method, which employs the adiabatic approximation to derive a set of ordinary differential equations for patterning modes, has been successfully applied to reaction-diffusion models for striped patterns [1]. Models of ocular dominance stripes have been studied [2,3] by computation, or by linearization of the model equations. These techniques do not provide (...) a rationale for the origin of the stripes. We show here that stripe formation is a non-linear property of the models. Our analysis indicates that stripe selection is closely linked to a property in the dynamics of the models which arises from a symmetry between ipsilateral and contralateral synapses to the visual cortex of a given hemisphere. (shrink)

A model of face representation, inspired by the biology of the visual system, is compared to experimental data on the perception of facial similarity. The face representation model uses aggregate primary visual cortex (V1) cell responses topographically linked to a grid covering the face, allowing comparison of shape and texture at corresponding points in two facial images. When a set of relatively similar faces was used as stimuli, this Linked Aggregate Code (LAC) predicted human performance in similarity judgment experiments. When (...) faces of perceivable categories were used, dimensions such as apparent sex and race emerged from the LAC model without training. The dimensional structure of the LAC similarity measure for the mixed category task displayed some psychologically plausible features but also highlighted differences between the model and the human similarity judgements. The human judgements exhibited a racial perceptual bias that was not shared by the LAC model. The results suggest that the LAC based similarity measure may offer a fertile starting point for further modelling studies of face representation in higher visual areas, including studies of the development of biases in face perception. (shrink)

Defenders of Motivational judgment internalism (MJI) argue that in one sense or another, our moral judgments necessarily motivate us to some extent. One of the most prominent defenders is Michael Smith, who in his highly influential book The Moral Problem defends a form of moral rationalism, which is the view that moral reasoning is based on practical reasoning, and thus that moral facts can and are determined a priori. This form of rationalism Smith claims to entail his account about internalism.One (...) of the main merits of Smith’s account of moral motivation is that it allows for individual difference in levels of moral motivation, by making the claim that moral judgments necessarily motivate defeasible. Before elaborating on how Smith does so, I shall first discuss Smith's approach in The Moral Problem, which will also help to set out the basic assumptions that will be taken for granted within this essay. I will then look at the account that he provides, and assess it with respect to one of Russ Shafer-Landau's criticisms thereof. Shafer-Landau rather helpfully puts Smith’s case for his moral rationalism in the form of what he calls ‘the incoherence argument’. The strongest problem that Shafer-Landau has with this argument seems to be with the following claim: ‘it is irrational for an individual to not desire what his fully rational self would desire’. What I hope to conclude is as follows: Although Smith’s account of internalism can for the most part withstand this objection that Shafer-Landau makes to it, even though Smith himself does not demonstrate any incoherence in failing to desire what one’s fully rational self would desire, in that a different kind of incoherence can be defended through other means. This would however result in a requirement for Smith to make significant concessions to his project in The Moral Problem. (shrink)

Contemporary philosopher Michael Walzer described the Problem of Dirty Hands as the choice between achieving a morally good end by violating one's own moral principles and sticking to one's moral principles without achieving this end. Walzer specifically explored this problem in the context of someone in the position of political power who can make a significant impact on the greater good but only through performing morally problematic deeds. In the 2016 film Doctor Strange, there are three characters who see themselves (...) as presented with this problem: the Ancient One, Kaecilius, and Doctor Stephen Strange himself. Of the three characters we've considered, the Ancient One most obviously faced the Problem of Dirty Hands. Dark magic is one of those things that are so dangerous that they're simply forbidden, even by the most adept of users, such as the Ancient One. (shrink)