Summary Prägnanz was suggested by Max Wertheimer in the 1920s as subsuming all “Laws of Gestalt” as they apply to visual awareness. Thus, it assumes a prominent position in any account of Gestalt phenomena. From a phenomenological perspective, some visual stimuli evidently “have more Prägnanz” than others, so Prägnanz seems to be an intensive quality. Here, we investigate the intricacies that need to be faced on the way to a definition of formal scales. Such measures naturally depend both upon the (...) stimulus and upon the observer. Structural complexity bottlenecks of visual systems play a role, as well as the relevance to biological fitness, that is the affinity to the optical user interface. This positions the notion of Prägnanz squarely within the realm of biology. Indeed, the familiar “releasers” of ethology are singular cases of extremely high Prägnanz. (shrink)

Summary In the visual arts, the constructions of the spatial and chromatic structures of pictures can hardly be separated from each other. The phenomenological approach from the perspective of the arts provides an independent and worthwhile approach to the topic of colour and space. We address some matters of composition in design and, to some extent, in naturalistic painting. The phenomenological approach from the perspective of the arts reveals various topics that invite further investigation by the means of generic vision (...) science. However, although such studies might lead to increased academic insight, a thorough inquiry by the means of experimental phenomenology might well lead to formal descriptions that come somewhat closer to possible applications in the visual arts. (shrink)

Nous abordons ici l’étude de la phénoménologie des objets visuels à partir de comptes rendus verbaux, de réponses à des questions ou de descriptions spontanées, ainsi que d’associations libres. Nous demandons même parfois aux sujets de réaliser de simples croquis. Cet éventail de méthodes permet de sonder la structure profonde de la conscience visuelle. Celle-ci est avant tout révélée par ce qui n’est pas spontanément mentionné par des qualités accidentelles ou encore par des changements induits lors de variations ou ajouts (...) mineurs. Nous avons trouvé une concordance remarquable parmi un grand nombre de participants. Ceci démonte que les comptes-rendus verbaux permettent d’explorer puissamment la structure de la conscience visuelle. Tout comme le langage, les « objets visuels simples » ont des racines profondes dans la conscience. Ces fondations « invisibles » servent à définir des figures simples, un « carré » par exemple, comme des objets prototypiques et uniques. La nature des « objets visuels » implique ainsi l’existence d’un « vaste domaine invisible ». Sans une telle prise en compte, la compréhension correcte de la nature de l’objet visuel n’est pas possible. Cette découverte devrait permettre de mener à une théorie de la syntaxe formelle des formes visuelles fondamentales. (shrink)

In this paper we contrast bounded and ecological rationality with a proposed alternative, generative rationality. Ecological approaches to rationality build on the idea of humans as “intuitive statisticians” while we argue for a more generative conception of humans as “probing organisms.” We first highlight how ecological rationality’s focus on cues and statistics is problematic for two reasons: the problem of cue salience, and the problem of cue uncertainty. We highlight these problems by revisiting the statistical and cue-based logic that underlies (...) ecological rationality, which originate from the misapplication of concepts in psychophysics. We then work through the most popular experimental task in the ecological rationality literature—the city size task—to illustrate how psychophysical assumptions have informally been linked to ecological rationality. After highlighting these problems, we contrast ecological rationality with a proposed alternative, generative rationality. Generative rationality builds on biology—in contrast to ecological rationality’s focus on statistics. We argue that in uncertain environments cues are rarely given or available for statistical processing. Therefore we focus on the psychogenesis of awareness rather than psychophysics of cues. For any agent or organism, environments “teem” with indefinite cues, meanings and potential objects, the salience or relevance of which is scarcely obvious based on their statistical or physical properties. We focus on organism-specificity and the organism-directed probing that shapes awareness and perception. Cues in teeming environments are noticed when they serve as cues-for-something, requiring what might be called a “cue-to-clue” transformation. In this sense, awareness toward a cue or cues is actively “grown.” We thus argue that perception might more productively be seen as the presentation of cues and objects rather than their representation. This generative approach not only applies to relatively mundane organism interactions with their environments—as well as organism-object relationships and their embodied nature—but also has significant implications for understanding the emergence of novelty in economic settings. We conclude with a discussion of how our arguments link with—but modify—Herbert Simon’s popular “scissors” metaphor, as it applies to bounded rationality and its implications for decision making in uncertain, teeming environments. (shrink)

I consider the geometrical structure of the apparent visual field. Although the optics of vision is well understood, the nature of visual awareness remains largely in the dark. A famous attempt at a formal description of the apparent visual field was by Helmholtz, in the late nineteenth century. It purportedly explains the phenomenon of the subjective curvatures often reported when viewing objectively straight lines of great extent. I consider the general problem, and suggest an alternative formal account. On phenomenological grounds (...) the very existence of a coherent geometry may be doubted. Yet, although seemingly an academic question, the issue has very real consequences. The two models I consider here may approximately apply to certain visual modes. The nature of such visual modes is discussed. (shrink)

Summary Franz Brentano, 1838–1917, introduced the intriguing concept of “plerosis” in order to account for aspects of the continuum that were “explained” by formal mathematics in ways that he considered absurd from the perspective of intuition, especially visual awareness and imagery. In doing this, he pointed in directions later developed by the Dutch mathematician Luitzen Brouwer. Brentano’s notion of plerosis involves distinct though coincident points, which one might call “atomic entities with parts”. This notion fits the modern concepts of “receptive (...) field” in neurophysiology, “perceptive field” in psychology and “differential operator” in the formal theory of scale space. We identify Brentano’s boundary points as the primordial atomic Gestalts of visual imagery. The concept deserves to play a key role in Gestalt theory. (shrink)