Vision, Action, and Make-Perceive

In this paper, I critically assess the enactive account of visual perception recently defended by Alva Noë (2004). I argue inter alia that the enactive account falsely identifies an object’s apparent shape with its 2D perspectival shape; that it mistakenly assimilates visual shape perception and volumetric object recognition; and that it seriously misrepresents the constitutive role of bodily action in visual awareness. I argue further that noticing an object’s perspectival shape involves a hybrid experience combining both perceptual and imaginative elements – an act of what I call ‘make-perceive.

Color for the perceptual organization of the pictorial plane: Victor Vasarely's legacy to Gestalt psychology

Victor Vasarely's (1906–1997) important legacy to the study of human perception is brought to the forefront and discussed. A large part of his impressive work conveys the appearance of striking three-dimensional shapes and structures in a large-scale pictorial plane. Current perception science explains such effects by invoking brain mechanisms for the processing of monocular (2D) depth cues. Here in this study, we illustrate and explain local effects of 2D color and contrast cues on the perceptual organization in terms of figure-ground assignments, i.e. which local surfaces are likely to be seen as “nearer” or “bigger” in the image plane. Paired configurations are embedded in a larger, structurally ambivalent pictorial context inspired by some of Vasarely's creations. The figure-ground effects these configurations produce reveal a significant correlation between perceptual solutions for “nearer” and “bigger” when other geometric depth cues are missing. In consistency with previous findings on similar, albeit simpler visual displays, a specific color may compete with luminance contrast to resolve the planar ambiguity of a complex pattern context at a critical point in the hierarchical resolution of figure-ground uncertainty. The potential role of color temperature in this process is brought forward here. Vasarely intuitively understood and successfully exploited the subtle context effects accounted for in this paper, well before empirical investigation had set out to study and explain them in terms of information processing by the visual brain

Change blindness: eradication of gestalt strategies

Arrays of eight, texture-defined rectangles were used as stimuli in a one-shot change blindness (CB) task where there was a 50% chance that one rectangle would change orientation between two successive presentations separated by an interval. CB was eliminated by cueing the target rectangle in the first stimulus, reduced by cueing in the interval and unaffected by cueing in the second presentation. This supports the idea that a representation was formed that persisted through the interval before being 'overwritten' by the second presentation (Landman et al, 2003 Vision Research 43149–164]. Another possibility is that participants used some kind of grouping or Gestalt strategy. To test this we changed the spatial position of the rectangles in the second presentation by shifting them along imaginary spokes (by ±1 degree) emanating from the central fixation point. There was no significant difference seen in performance between this and the standard task [F(1,4)=2.565, p=0.185]. This may suggest two things: (i) Gestalt grouping is not used as a strategy in these tasks, and (ii) it gives further weight to the argument that objects may be stored and retrieved from a pre-attentional store during this task

Quasi-Modal Encounters Of The Third Kind: The Filling-In Of Visual Detail

Although Pessoa et al. imply that many aspects of the filling-in debate may be displaced by a regard for active vision, they remain loyal to naive neural reductionist explanations of certain pieces of psychophysical evidence. Alternative interpretations are provided for two specific examples and a new category of filling-in (of visual detail) is proposed

Modelling the human perception of shape-from-shading

Shading conveys information on 3-D shape and the process of recovering this information is called shape-from-shading (SFS). This thesis divides the process of human SFS into two functional sub-units (luminance disambiguation and shape computation) and studies them individually. Based on results of a series of psychophysical experiments it is proposed that the interaction between first- and second-order channels plays an important role in disambiguating luminance. Based on this idea, two versions of a biologically plausible model are developed to explain the human performances observed here and elsewhere. An algorithm sharing the same idea is also developed as a solution to the problem of intrinsic image decomposition in the field of image processing. With regard to the shape computation unit, a link between luminance variations and estimated surface norms is identified by testing participants on simple gratings with several different luminance profiles. This methodology is unconventional but can be justified in the light of past studies of human SFS. Finally a computational algorithm for SFS containing two distinct operating modes is proposed. This algorithm is broadly consistent with the known psychophysics on human SFS

6th International Meeting on Retouching of Cultural Heritage, RECH6

RECH Biennial Meeting is one of the largest educational and scientific events in Retouching field, an ideal venue for conservators and scientists to present their research results about retouching. The main focus will be to promote the exchange of ideas, concepts, terminology, methods, techniques and materials applied during the retouching process in different areas of conservation: mural painting, easel painting, sculpture, graphic documentation, architecture, plasterwork, photography, contemporary art, among others. This Meeting aims to address retouching by encouraging papers that contribute to a deeper understanding of this final task of the conservation and restoration intervention. The main theme embraces the concepts of retouching, the criteria and limits in the retouching process, the bad retouching impact on heritage and their technical and scientific developments.This Meeting will discuss real-life approaches on retouching, focusing on practical solutions and on sharing experiencesColomina Subiela, A.; Doménech García, B.; Bailão, A. (2023). 6th International Meeting on Retouching of Cultural Heritage, RECH6. Editorial Universitat Politècnica de València. https://doi.org/10.4995/RECH6.2021.1601

Herm as askesis: prosthetic conditions of painting

This research project asks how a consideration of Greek herm sculpture can be put to use in exploring prosthetic conditions of painting. This question is addressed through a series of essays and a body of studio-based art work, undertaken at the RCA from 2010 to 2015. The written submission contains a series of interconnected essays, through which prosthetic conditions of painting are explored via Greek herm sculpture, in order to reassess the work of contemporary and historical painter’s practices. The first chapter looks to a history of herm sculpture, focusing on the roles it has performed around the age of Alcibiades, of Athens 4 B.C. This assessment is aided by Michel Foucault’s notion of askesis and Pierre Hadot’s work on spiritual exercises. They enable a shift, from understanding the herm as a physical object to the historical roles it has performed in Greek culture — as a desecrated object, boundary-marker, object of ritual and, via its connection to hermes, a means of interpretation, bodily passage and transition. I address a collection of essays ‘Six Memos for the Next Millennium’, by Italo Calvino, and his connection to The Workshop for Potential Literature (Oulipo), in order to understand the use of literary restraints as exercises which offer a preliminary guide to how the herm can be used in this project. Through Foucault, Hadot and Calvino, the herm transitions from object to an askesis — undertaking tasks that perform in essays and paintings. The subsequent essays focus on the work of Lynda Benglis, Orlan, Caravaggio, François Boucher and Imi Knoebel, addressed through contemporary thinkers that undertake considerations of the prosthetic. The intersection of material culture studies, feminist theory, disabilities studies and poststructuralism, offer a view to the prosthetic that creates a platform for a reconsideration of these artists’ work. The herm becomes a silent guide in this project, understanding the prosthetic as imbedded in ideas of the relational — sensitive to the way in which body and paint, silicone and skin can adjoin, supplant, intersect, enhance and compensate, between subjects and objects. By inserting the prosthetic into narratives that question the relationships between bodies, objects and surfaces in these artist’s work — and in asking what they can produce — this project explores and articulates prosthetic conditions of painting

Principles of perceptual grouping: implications for image-guided surgery

Gestalt theory has provided perceptual science with a conceptual framework which has inspired researchers ever since, taking the field of perceptual organization into the 21st century. This opinion article discusses the importance of rules of perceptual organization for the testing and design of visual interface technology. It is argued that major Gestalt principles, such as the law of good continuation or the principle of Praegnanz (suggested translation: salience), taken as examples here, are important to our understanding of visual image processing by a human observer. Perceptual integration of contrast information across collinear space, and the organization of objects in the 2D image plane into figure and ground are of a particular importance here. Visual interfaces for image-guided surgery illustrate the criticality of these two types of perceptual processes for reliable decision making and action. It is concluded that Gestalt theory continues to generate powerful concepts and insights for perceptual science placed within the context of major technological challenges of today

Enlightened Romanticism: Mary Gartside’s colour theory in the age of Moses Harris, Goethe and George Field

The aim of this paper is to evaluate the work of Mary Gartside, a British female colour theorist, active in London between 1781 and 1808. She published three books between 1805 and 1808. In chronological and intellectual terms Gartside can cautiously be regarded an exemplary link between Moses Harris, who published a short but important theory of colour in the second half of the eighteenth century, and J.W. von Goethe’s highly influential Zur Farbenlehre, published in Germany in 1810. Gartside’s colour theory was published privately under the disguise of a traditional water colouring manual, illustrated with stunning abstract colour blots (see example above). Until well into the twentieth century, she remained the only woman known to have published a theory of colour. In contrast to Goethe and other colour theorists in the late 18th and early 19th century Gartside was less inclined to follow the anti-Newtonian attitudes of the Romantic movement