Academic literature on the topic 'Figure-ground perception. Time perception. Orientation (Psychology)'

How does biological motion perception change with display orientation? As previously shown, display inversion (180°) completely prevents veridical perception of biological motion. However, with upright orientation (0°), observers are able to recover the invariant structure through biological motion despite reverse transformation (showing the film backwards) or changing the presentation rate (Pavlova, 1995 Perception24 Supplement, 112). In the present experiments, observers saw the biological motion pattern at various display deviations, from inverted to upright orientation (180°, 150°, 120°, 90°, 60°, 30°, 0°), in the right or left hemifield, on a circular screen monitor. The display consisted of an array of 11 dots on the main joints of an invisible walker moving as if on a treadmill. While viewing (60 s), observers pressed a key each time their perception changed from one stable percept to another (eg when the direction of apparent rotation of the pattern reversed). The perceived multistability (the number of key-presses) increased as orientation was varied from inverted to 90°, and then decreased between 90° and upright. The recognition of walking figure improved abruptly with changing orientation: at deviations of 60° and 30° most observer reported seeing the walking figure spontaneously, yet the pattern was seen as multistable. The findings imply the relative power of constraints (such as orientation) in perception of biological motion that is discussed in relation to the KSD principle in event perception [Runeson, 1994, in Perceiving Events and Objects Eds Jansson, Epstein, Bergström (Hillsdale, NJ: Erlbaum) pp 383 – 405].

One of the processes of visual perception is to organise 2-D images into figure and ground, assigning the borders to the figure. We have studied the neural basis of this phenomenon. We recorded from orientation-selective cells of areas V1 and V2 in the awake, fixating monkey. A square (typically 4 deg) of uniform colour or gray was displayed in a uniform surround field (11 deg) of different colour or gray. The square was much larger than the response fields of the cells studied. Its orientation and colour were optimised for each cell. In interleaved tests, we centred two opposite edges of the square in the RF, and also reversed the colours of square and surround, resulting in four different display combinations. Flipping edges and colours produced pairs of displays with an identical edge in the response field, but the figure on opposite sides. The display was static for each period of fixation, and mean spike numbers per second were measured. Many cells were selective for the sign of local contrast. In V2 we found cells that were highly discriminative for the direction of the figure, eg responding 10 times more to the left edge of a gray square with white surround than to the right edge of a white square with gray surround. In some cells, this discrimination was nearly independent of the figure size. The response could either be independent of local contrast (general edge assignment), or conditional on figure colour (joint assignment of edge and colour). We have observed direction-of-figure preference also in V1, but with smaller discrimination ratios. We conclude that figural edge assignment is part of early cortical processing.

This is a report of a studio experiment to explore how images from the camera obscura could have been used directly by artists of Vermeer’s era. It has a pragmatic and practical approach, bringing a painter’s eye and experience to the problems of transferring images from the lens to a canvas, using the primitive technology and unrefined materials available then. It addresses how an artist could use the condensed, flattened images from camera obscura projections in his painting process, when the subject could appear reversed and inverted on the screen or on the wall. It considers how the limitations of the materials that make transfers possible might affect studio practice, and ultimately the stylistic qualities of the work produced. This paper outlines a simple printing method that would enable the seventeenth-century painter to transfer monochrome images, corrected in orientation, from the lens to a canvas with relative ease, for use as the painting progressed in the stages prescribed at the time. Prints made on the ground layer could form the basis of underpainting, while those on top layers could transfer highlights and optical effects, not seen with the naked eye. This technique would allow the painter to be in the light of his studio, facing his motif, when working in colour. Reference is made to art historical literature and contemporary workshop treatises, and all materials used are authentic. The results obtained using this process are consistent with the visual evidence of the way in which Vermeer applied his paint, and with recent scientific examination of his work. The findings suggest possible causes for some of the unusual qualities of Vermeer’s work, in particular the strong tonal polarity in the underpainting with no evidence of drawing, his choice of material in the ground layers, and the qualities of variable focus.

Gestalt psychologists in the early part of the century challenged psychophysical notions that perceptual phenomena can be understood from a punctate (‘atomistic’) analysis of the elements present in the stimulus. Their ideas also inhibited later attempts to explain vision in terms of single-unit recordings from individual neurons. A rapprochement between Gestalt phenomenology and physiology seemed unlikely when the first ECVP was held in Marburg, Germany, in 1978. Since that time, response properties of neurons have been discovered that invite an interpretation of visual phenomena (including ‘illusions’) in terms of neuronal processing. Indeed, it is now possible to understand some Gestalt phenomena on the basis of known neurophysiological mechanisms. I begin by outlining the great strides that have been made since the advent of microelectrode recording from single neurons. Initially, cells (‘detectors’) selectively responding to the contrast, spatial frequency, wavelength, orientation, movement, and disparity of a stimulus placed in their receptive fields were used to interpret simple perceptual phenomena (eg, Mach bands, Hermann grids, tilt aftereffect, MAE). In recent years, cells at higher levels of the visual system have been discovered that might explain a number of more complex phenomena: the perception of illusory (occluded) contours by end-stopped cells in area V2, the filling-in of artificial scotomata by neurons in V3, colour constancy by ‘perceptive’ neurons in V4, and the perception of coherent motion in dynamic noise patterns by cells in MT. Studies of flow fields and biological motion in area MST have recently been added to account for our perceptions as we move through our environment. Prompted by these findings, a shift from local to global interactions ‘beyond the classical receptive field’ has taken place in our search for the neural substrates of perception. Current research has focused on three kinds of mechanisms: (i) converging feed-forward projections as the basis for new response properties emerging at higher levels, (ii) recruitment of lateral connections to explain filling-in, and (iii) backward propagation from higher to lower levels to account for binding and figure - ground segregation. How such mechanisms compute large-scale surface properties such as brightness, colour, and depth from local features—indeed how they construct the surfaces themselves from complex natural scenes—is only one of the many questions that are under scrutiny today. Future research will have to tackle the all-important question: How does the analysed information come together again? Furthermore, the contributions of eye movements, attention, learning, other sense modalities, and motor actions will have to be taken into consideration before we arrive at a more complete understanding of visual perception.

Perception of intentions and dispositions of others is an essential ingredient of adaptive daily-life social behaviour. Dynamics of moving images leads to veridical perception of social attributes. Anecdotal observations in art, science, and popular culture indicate that dynamic imbalance can be revealed in static images. Here, we ask whether perceived dynamics of abstract figures is related to emotional attribution. Participants first estimated instability of geometric shapes rotated in 15° steps in the image plane, and then rated the intensity of basic emotions that can be ascribed to the figures. We found no substantial link between the deviation of the figures from the vertical orientation and perceived instability. Irrespective of shape, a strong positive correlation was found between negative emotions and perceived instability. By contrast, positive emotions were inversely linked with deviation of the figure from vertical orientation. The work demonstrates for the first time that dynamics conveyed by static images enables specific emotional attributions, and agrees well with the assumption that neural networks for production of movements and understanding the dispositions of others are intimately linked. The findings are also of importance for exploring the ability to reveal social properties through dynamics in normal and abnormal development, for example in patients with early brain injury or autistic spectrum disorders.

The advent of inexpensive consumer virtual reality equipment enables many more researchers to study perception with naturally moving observers. One such system, the HTC Vive, offers a large field-of-view, high-resolution head mounted display together with a room-scale tracking system for less than a thousand U.S. dollars. If the position and orientation tracking of this system is of sufficient accuracy and precision, it could be suitable for much research that is currently done with far more expensive systems. Here we present a quantitative test of the HTC Vive’s position and orientation tracking as well as its end-to-end system latency. We report that while the precision of the Vive’s tracking measurements is high and its system latency (22 ms) is low, its position and orientation measurements are provided in a coordinate system that is tilted with respect to the physical ground plane. Because large changes in offset were found whenever tracking was briefly lost, it cannot be corrected for with a one-time calibration procedure. We conclude that the varying offset between the virtual and the physical tracking space makes the HTC Vive at present unsuitable for scientific experiments that require accurate visual stimulation of self-motion through a virtual world. It may however be suited for other experiments that do not have this requirement.

Background. Continuing trends dated back in the second part of XIX century music culture concentrate on a figure of performing musician. Commercialization an academic art: popularity of performance awards, media supporting for new formats of concert performance, etc. facilitates this largely. Objectives. Public interest conditioned an appearance a lot of scientific research inscribed to problems of musical interpretation. However, a performing oeuvre learning the product, fixation of which even taking to account modern recording capabilities are relative, warrants specific methods. In particular, engaging the conception of values for settlement of a question why performing art products are different with their significance: something becomes a culture phenomenon but something stays at self-actualization level. Methods. For comprehensive study the performing as separate kind of activity it is necessary to involve adjacent humanitaristics areas – psychology and philosophy, which problems of art and it’s osmosis are considered in. In particular, in philosophy art is understood as a kind of human activity aimed at creating new-look material and culture valuables. However, in our perspective more interesting and capacious definition is seem N. Berdyaev’s one: «Art is a human ability to create a new reality from valid material». That picturesque vision of the author’s work, which springs up during an interpretation, often has a wide public interest that let assign to interpretator a status of the creator. Such an understanding of performing musician’s figure significant we can find in foreign philosophers’ works (R. Ingarden, B. Croce) and native music scientists (B. Moskalenko, I. Sukhlenko). Such an understanding of performing musician’s figure significant we can find in foreign philosophers’ works (R. Ingarden, B. Croce) and native music scientists (B. Moskalenko, I. Suchlenko). Results. E. Husserl’s phenomenological conception had a great impact not only on XX th century philosophy but on many humanities science especially art history. It led to the fact that there are many definitions of phenomenon concept, which is interpreted as a reflection of world of ideas, an object that is accessible to the senses, a basic holistic unit of what can be isolated from consciousness, external properties and subject concern revealing its essence, etc. A unite part all of definitions is a sensorial perception as a base of human knowledge based on individual experience and ability of consciousness to self observation and reflection. Stickling example of this is a field of artistry, which individual sensorial perception takes such a big part in that identity of the creator, his feelings often become the centerpiece of work. In musical oeuvre, an outward subjectivization is an acoustic convergent thinking. However, musical thesaurus is enough for power of imagining wakening enabling reproducing and combination the phenomenal stored in composer-performer-hearer’s memory. Performing art based on searching the new acoustic and dramatic source material characteristics. Thereat performer’s work algorithm depends largely on personal intention based on world and mental outlook. The scale of performer identity, his internal conviction power whereby he creates the new acoustic reality is able to notably change all the elements of composer’s intention and affect our perception of musical composition. In that understanding, the special aspects of composer’s activities, its interconnection and correlation with his oeuvre are opened in other view. Brilliant performance reformatting an art space composer’s work frequently appropriates him «double authorship». As a result is a phenomenon of identification with the name of great composer: L. Beethoven’s 5th Symphony – G. Von Karajan / L. Stokowski; J. S. Bach’s Goldberg Variations – G. Gould / R. Tureck; F. Сhopin’s works – V. Sofronitsky / V. Horowitz; P. Tchaikovsky – M. Pletnev. Exactly this influence aspect of performing art on the musical culture interested B. Croce who confirmed that musical composition only exists at the time of execution. However, choice the pair «composer-performer» depends up our perception, our readiness to acceptance an alternative artistic concept. Herewith prescription, forming «set» of value orientation of some shared identity: from group of like-minded persons to mass convictions, has a great impact here. The latter’s impact differs under studying a creativity of famous musicians and soi-disant «second place» musicians who fall under external influence easier than others do. Even in the light of constant changes of public conscience, one can highlight some hard values in it that characterize certain social stratums. However, and these value systems undergo a review for a time and modern society reject what was topically a couple decades ago. The result is that fashion phenomenon on performers or performing style appears. Accordingly, to continue to be relevant performing musician needs to have a gust of latest tendencies in art and to able to save value bases of personal mental outlook. Conclusions. The phenomenological approach to the study of the creative activity of a musician-performer allows one to go beyond the theoretic analysis that is traditional for musicology. Acceptance that the product of performing creativity can be defined as a phenomenon, reflecting several vectors of personal communication (dialogue with oneself, with a composer, public, historical epoch), can help not only in understanding the “musical work of the performer”, but also in understanding the phenomenal significance of performers in modern musical culture.

The assumption that figure-ground segmentation must precede object or shape recognition has been central to theories of visual perception We showed that assumption to be incorrect in an experiment in which observers reported the first perceived figure-ground organization of briefly exposed stimuli depicting two regions sharing a figure-ground border We manipulated the symmetry of the two regions and their orientation-dependent denotivity (roughly, their meaningfulness), and measured how each of these variables influenced figure-ground reports when the stimuli were exposed for 14, 28, 57, 86, or 100 ms, and followed immediately by a mask Influences on figure-ground organization from both symmetry and orientation-dependent object recognition processes were found, both were observed first in the 28-ms condition Object recognition inputs did not dominate symmetry inputs We suggest that object recognition processes may operate simultaneously on both sides of edges detected before figure-ground relationships are determined

348 adolescents, 176 male and 172 female, were administered six different spatial tests. Awareness of figural proportion, figural memory, and figure-ground perception contributed significantly to performance on spatial visualization tests but not to performance on spatial orientation tests. Similarly, severity of hearing loss was correlated with scores on visualization tests but not on spatial-orientation tests.

Between the late 1800s and the early 1900s, sociologists in Germany focused their interest on the beginning of modern times, the increase in social diversification, the affirmation of an individualistic orientation and, in particular, of metropolises and the appearance of new figures in urban spaces. Tönnies and Simmel concentrated their studies on the social figure of the foreigner as a metaphor of modernity and, though through different cognitive approaches, defined a strongly converging social representation. In both authors we find that the foreigner's ambivalence is based on traits such as lack of fixation in social space, mobility, freedom, individualistic orientation and objectivity. Their considerations differ however in regards to the perception of this figure as being an isolated individual or referred to as a «type»: in Tönnies we see the first orientation, whereas Simmel believes that the foreigner is perceived through reference to a social «type», thus with a more structured representation. In such a way Simmel anticipates a theme that will later be further developed by sociology and social psychology.

The visual system receives a series of fluctuating light patterns on the retina, yet visual perception is strikingly different from this unorganized and ambiguous input. Thus visual processes must organize the input into coherent units, or objects, and segregate them from others. These processes, collectively called perceptual organization, are fundamental to our ability to perceive and interact with objects in the world. Nevertheless, they are not yet understood, perhaps because serial, hierarchical assumptions that were long held impeded progress. In a series of experiments, this dissertation investigated the mechanisms that contribute to perceptual organization and ultimately to our ability to perceive objects. A new hypothesis is that during the course of object assignment potential objects on either side of a border are accessed on a fast pass of processing and engage in inhibitory competition for object status; the winner is perceived as the object and the loser is suppressed, leading that region to be seen as part of the shapeless background. Previous research suggested that at least shape level representations are accessed on the fast pass of processing before object assignment. In the first series of experiments (Chapter 1), we found that meaning (semantics) is also accessed on the fast pass of processing for regions that are ultimately perceived as shapeless grounds. This finding contradicts traditional feed-forward theories of perception that assumed that meaning is accessed only for figures after object assignment. The experiments in Chapter 2 examine activity in the alpha band of the EEG, which has been used as an index of inhibition. More alpha activity was observed when participants viewed stimuli designed such that there was more competition for figural status from the region ultimately perceived as the ground. The results support the proposal that inhibitory competition occurs during the course of object perception, and these results are the first online measure of competition during figure assignment. The final series of experiments (Chapter 3) investigated how quickly saccadic behaviors that required perceptual organization can be initiated. The experiments show that participants can initiate saccades that are based on perceptual organization approximately 200 ms after stimulus onset, much faster than was assumed on feed-forward models of perception. Collectively, these experiment support models of object perception that involve the mutual interaction and competition of objects properties via feedforward and iterative feedback processing, and the eventual suppression of the losing ground regions before object assignment.

One of the best known accounts of the psychology of perception is Richard Gregory’s book Eye and Brain (Gregory 1998). It is relevant to this chapter because it uses an example from archaeology to illustrate the way in which the mind creates visual patterns. The author considers the methods by which excavators distinguish between the remains of rectangular and circular buildings. He considers the Middle Bronze Age settlement of Thorny Down in southern England, where different scholars have inferred the existence of different types of buildings on the basis of the same field evidence. The original excavator was uncertain of the precise form of the settlement (Stone 1941), but, in later years, Piggott identified the site of a large rectangular house there (1965: Figure 87) and Musson recognized circular structures (1970: 267; Figure 57). Gregory’s summary of their method is as follows:… Science and perception work by knowledge and rules, and by analogy . . . [In the case of Thorny Down] some of the holes in the ground might be ancient post holes; others might be rabbit holes, to be ignored. One group of archaeologists accepted close-together large holes as evidence of a grand entrance. They were altogether rejected by other archaeologists. One group constructed a large rectangular hut; the other, a small rectangular hut, and a circular building. ‘Bottomup’ rules—holes being close together and forming straight lines or smooth curves, and ‘top-down’ knowledge or assumptions of which kinds of buildings were likely—affected the ‘perceptions’. Both could have been wrong (1998: 11–12)…. The identification of a rectangular building at Thorny Down took place at a time when it was believed that the Netherlands had been settled from England during the Bronze Age. The argument was based on pottery styles and the distribution of metalwork (Theunissen 2009). Most likely there were contacts in both directions. As the Low Countries were characterized by a tradition of rectilinear architecture, what could be more natural than the construction of a longhouse at a site on the Wessex chalk? Dutch prehistorians attempted to find similar links between domestic architecture on both sides of the North Sea and soon they identified roundhouses of British type in their excavations.