After more than three centuries, Molyneux's question continues to challenge our understanding of cognition and perceptual systems. Locke, the original recipient of the question, approached it as a theoretical exercise relevant to long-standing philosophical issues, such as nativism, the possibility of common sensibles, and the empiricism-rationalism debate. However, philosophers were quick to adopt the experimentalist's stance as soon as they became aware of recoveries from congenital blindness through ophtalmic surgery. Such recoveries were widely reported to support empiricist positions, suggesting that (...) the question had found its empirical answer. Contrary to this common view, we argue that studies of patients recovering from early blindness through surgery cannot provide an answer. In fact, because of the very nature of such ophtalmological interventions it is impossible to test the question in the empirical conditions outlined by Molyneux. Thus we propose that Molyneux's question be treated as an early thought experiment of a specific kind. Although thought experiments of this kind cannot be turned into actual experimental conditions, they provide a conceptual restructuring of theories. Such restructuring in turn leads to new predictions that can then be tested by normal experiments. In accord with this interpretation, we show that Molyneux's question can be analyzed into a hierarchy of specific questions about vision in its phenomenal and sensory-motor components. Some of these questions do lead to actual experimental conditions that could be studied empirically. (shrink)

The planning/control distinction is an important tool in the study of sensorimotor transformations. However, published data from our laboratories suggest that, contrary to what is predicted by the proposed model, (1) structures in the superior parietal lobe of both monkeys and humans can be involved in movement planning; and (2) fast pointing actions can be immune to visual illusions even if they are performed without visual feedback. The planning–control model as proposed by Glover is almost certainly too schematic.

Because theories of visual perception have traditionally concentrated on form, artists have generally dealt with the problem of color through their own observation and intuition. In _Color Harmonies,_ Augusto Garau systematically investigates the role of both color and form in visual perception and presents an original theory of the aesthetic relations among colors. Garau, a painter who teaches the psychology of form, pays particular attention to the way colors behave when organized in patterns. His theory of color combination addresses two (...) principal compositional elements: the relations between figure and ground and the phenomenon of transparency. Garau meticulously analyzes the use of color in paintings by masters such as Cézanne, Picasso, and Matisse to show how his theory applies to actual works of art. Containing many full-color examples, his introduction to the workings of color relations is of great practical use to art historians and critics, artists, interior decorators, fashion and set designers, and anyone who works with color to display information or convey emotions. "In an area of the psychology of art where reliable guidance is still so hard to come by, [Garau's] well-supported contributions to the theory of color composition ought to be welcomed by practitioners and scholars alike."—from the Foreword by Rudolf Arnheim. (shrink)

Trichromacy may result from an adaptation to the regularities in terrestrial illumination. However, we suggest that a complete characterization of the challenges faced by colour perception must include changes in surface surround and illuminant changes due to inter-reflections between surfaces in cluttered scenes. Furthermore, our trichromatic system may have evolved to allow the detection of brownish-reddish edibles against greenish backgrounds. [Shepard].