The major theoretical framework relative to the perception of illusory figures is reviewed and discussed in the attempt to provide a unifying explanatory account for these phenomena.

Following the pioneering studies of the receptive field (RF), the concept gained further significance for visual perception by the discovery of input effects from beyond the classical RF. These studies demonstrated that neuronal responses could be modulated by stimuli outside their RFs, consistent with the perception of induced brightness, color, orientation, and motion. Lesion scotomata are similarly modulated perceptually from the surround by RFs that have migrated from the interior to the outer edge of the scotoma and in this way (...) provide filling-in of the void. Large RFs are advantageous to this task. In higher visual areas, such as the middle temporal and inferotemporal lobe, RFs increase in size and lose most of their retinotopic organization while encoding increasingly complex features. Whereas lowerlevel RFs mediate perceptual filling-in, contour integration, and figure–ground segregation, RFs at higher levels serve the perception of grouping by common fate, biological motion, and other biologically relevant stimuli, such as faces. Studies in alert monkeys while freely viewing natural scenes showed that classical and nonclassical RFs cooperate in forming representations of the visual world. Today, our understanding of the mechanisms underlying the RF is undergoing a quantum leap. What had started out as a hierarchical feedforward concept for simple stimuli, such as spots, lines, and bars, now refers to mechanisms involving ascending, descending, and lateral signal flow. By extension of the bottom-up paradigm, RFs are nowadays understood as adaptive processors, enabling the predictive coding of complex scenes. Top-down effects guiding attention and tuned to task-relevant information complement the bottom-up analysis. (shrink)

We present select examples of how visual phenomena can serve as tools to uncoverbrain mechanisms. Specifically, receptive field organization is proposed as a Gestalt-like neural mechanism of perceptual organization. Appropriate phenomena, such as brightness and orientation contrast, subjective contours, filling-in, and aperture-viewed motion, allow for a quantitative comparison between receptive fields and their psychophysical counterparts, perceptive fields. Phenomenology might thus be extended from the study of perceptual qualities to their transphenomenal substrates, including memory functions. In conclusion, classic issues of Gestalt (...) psychology can now be related to modern. (shrink)

Pessoa et al. provide a valuable taxonomy of perceptual completion phenomena, but it is not yet clear whether these phenomena are mediated by one kind of neural mechanism or more. We suggest three possible neural mechanisms of long-range interaction to stimulate further perceptual and neurophysiological investigation of perceptual completion and filling-in.

This classic work in vision science, written by a leading figure in Germany's Gestalt movement in psychology and first published in 1936, addresses topics that remain of major interest to vision researchers today. Wolfgang Metzger's main argument, drawn from Gestalt theory, is that the objects we perceive in visual experience are not the objects themselves but perceptual effigies of those objects constructed by our brain according to natural rules. Gestalt concepts are currently being increasingly integrated into mainstream neuroscience by researchers (...) proposing network processing beyond the classical receptive field. Metzger's discussion of such topics as ambiguous figures, hidden forms, camouflage, shadows and depth, and three-dimensional representations in paintings will interest anyone working in the field of vision and perception, including psychologists, biologists, neurophysiologists, and researchers in computational vision--and artists, designers, and philosophers.Each chapter is accompanied by compelling visual demonstrations of the phenomena described; the book includes 194 illustrations, drawn from visual science, art, and everyday experience, that invite readers to verify Metzger's observations for themselves. Today's researchers may find themselves pondering the intriguing question of what effect Metzger's theories might have had on vision research if Laws of Seeing and its treasure trove of perceptual observations had been available to the English-speaking world at the time of its writing. (shrink)

There are few articles in science that remain relevant over a span of 100 years; Max Wertheimer's pioneering experimental studies on apparent motion and figural organization are notable exceptions. Wertheimer's 1912 account of motion perception started a revolution and established the Gestalt school of psychology. It also paved the way for further investigations of apparent motion perception, including subsequent research by Oliver Braddick, Stuart Anstis, Vilaynur Ramachandran, and others. Wertheimer's 1923 article on figural organization helped define grouping as a principle (...) of figure-ground perception. This book provides contemporary readers and researchers with Wertheimer's two pivotal articles, newly translated into English and each accompanied by a synopsis, and two essays on apparent motion and figural organization that describe the long-term impact of Wertheimer's work. The translation of the original German into readable English prose allows English-language readers for the first time to appreciate Wertheimer's visionary ideas. The accompanying essays tie Wertheimer's phenomenological descriptions to the underlying neuronal mechanisms, bridging the years between the articles' first publication and modern research. (shrink)