Perceived slant has often been characterized as a component of 3D shape perception for polyhedral objects. Like 3D shape, slant is often perceived inaccurately. Lind, Lee, Mazanowski, Kountouriotis, ...and Bingham (2014) found that 3D shape was perceived accurately with perspective changes ≥45°. We now similarly tested perception of 3D slant. To account for their results, Lind et al. (2014) developed a bootstrap model based on the assumption that optical information yields perception of 3D relief structure then used with large perspective changes to bootstrap to perception of 3D Euclidean structure. However, slant perception usually entails planar surfaces and structure-from-motion fails in the absence of noncoplanar points. Nevertheless, the displays in Lind et al. (2014) included stereomotion in addition to monocular optical flow. Because stereomotion is higher order, the bootstrap model might apply in the case of strictly planar surfaces. We investigated whether stereomotion, monocular structure-from-motion (SFM), or the combination of the two would yield accurate 3D slant perception with large continuous perspective change. In Experiment 1, we found that judgments of slant were inaccurate in all information conditions. In Experiment 2, we added noncoplanar structure to the surfaces. We found that judgments in the monocular SFM and combined conditions now became correct once perspective changes were ≥45°, replicating the results of Lind et al. (2014) and supporting the bootstrap model. In short, we found that noncoplanar structure was required to enable accurate perception of 3D slant with sufficiently large perspective changes.
Public Significance Statement
A majority of the studies on slant perception as well as perception of other spatial properties, like shape, have shown perception is inaccurate. This is a problem for the control of actions that are not continuously guided by vision. In this study, we investigated visual information generated by motion, and showed that with sufficiently large continuous perspective change, surface orientation was perceived accurately. Such perspective changes would be generated by the locomotion of observers in everyday environments. This result not only provided additional confirmation for a model developed in a previous study on accurate shape perception, but also showed that the 3D structure of natural environments is important for perception of surface orientations.
In Inhabited Spaces, Nicole Guenther Discenza examines a variety of Anglo-Latin and Old English texts to shed light on Anglo-Saxon understandings of space.
Speech is robustly audiovisual from early in infancy. Here we show that audiovisual speech perception in 4.5-month-old infants is influenced by sensorimotor information related to the lip movements ...they make while chewing or sucking. Experiment 1 consisted of a classic audiovisual matching procedure, in which two simultaneously displayed talking faces (visual i and u) were presented with a synchronous vowel sound (audio /i/ or /u/). Infants' looking patterns were selectively biased away from the audiovisual matching face when the infants were producing lip movements similar to those needed to produce the heard vowel. Infants' looking patterns returned to those of a baseline condition (no lip movements, looking longer at the audiovisual matching face) when they were producing lip movements that did not match the heard vowel. Experiment 2 confirmed that these sensorimotor effects interacted with the heard vowel, as looking patterns differed when infants produced these same lip movements while seeing and hearing a talking face producing an unrelated vowel (audio /a/). These findings suggest that the development of speech perception and speech production may be mutually informative.
We present novel evidence showing that new self-relevant visual associations can affect performance in simple shape recognition tasks. Participants associated labels for themselves, other people, or ...neutral terms with geometric shapes and then immediately judged whether subsequent label-shape pairings were matched. Across 4 experiments there was a reliable self-prioritization benefit on response times and perceptual sensitivity that remained across different presentation contexts (with self, best friend, and unfamiliar others in Experiment 1; with self, best friend, and neutral terms, and with self, mother, and neutral terms in Experiments 2A and 2B, respectively). Control studies in Experiment 3 indicated that the results did not reflect the length, concreteness, or familiarity of the words. The self-prioritization effect on shape matching also increased when stimuli were degraded (self shapes showing weaker effects of degradation) in Experiment 4A, consistent with self-information modulating perceptual processing. A similar effect was found when people associated different reward values to the shape in Experiment 4B. The results indicate that associating a stimulus to the self modulates its subsequent perceptual processing, and this may operate by self-associated shapes automatically evoking the reward system. (Contains 3 tables, 5 figures and 4 footnotes.)
Human multisensory systems are known to bind inputs from the different sensory modalities into a unified percept, a process that leads to measurable behavioral benefits. This integrative process can ...be observed through multisensory illusions, including the McGurk effect and the sound-induced flash illusion, both of which demonstrate the ability of one sensory modality to modulate perception in a second modality. Such multisensory integration is highly dependent upon the temporal relationship of the different sensory inputs, with perceptual binding occurring within a limited range of asynchronies known as the temporal binding window (TBW). Previous studies have shown that this window is highly variable across individuals, but it is unclear how these variations in the TBW relate to an individual's ability to integrate multisensory cues. Here we provide evidence linking individual differences in multisensory temporal processes to differences in the individual's audiovisual integration of illusory stimuli. Our data provide strong evidence that the temporal processing of multiple sensory signals and the merging of multiple signals into a single, unified perception, are highly related. Specifically, the width of right side of an individuals' TBW, where the auditory stimulus follows the visual, is significantly correlated with the strength of illusory percepts, as indexed via both an increase in the strength of binding synchronous sensory signals and in an improvement in correctly dissociating asynchronous signals. These findings are discussed in terms of their possible neurobiological basis, relevance to the development of sensory integration, and possible importance for clinical conditions in which there is growing evidence that multisensory integration is compromised.
Imagine a pack of predators stalking their prey. The predators may not always move directly toward their target (e.g., when circling around it), but they may be consistently facing toward it. The ...human visual system appears to be extremely sensitive to such situations, even in displays involving simple shapes. We demonstrate this by introducing the wolfpack effect, which is found when several randomly moving, oriented shapes (darts, or discs with "eyes") consistently point toward a moving disc. Despite the randomness of the shapes' movement, they seem to interact with the disc—as if they are collectively pursuing it. This impairs performance in interactive tasks (including detection of actual pursuit), and observers selectively avoid such shapes when moving a disc through the display themselves. These and other results reveal that the wolfpack effect is a novel "social" cue to perceived animacy. And, whereas previous work has focused on the causes of perceived animacy, these results demonstrate its effects, showing how it irresistibly and implicitly shapes visual performance and interactive behavior.
In 1912, Max Wertheimer published his paper on phi motion, widely recognized as the start of Gestalt psychology. Because of its continued relevance in modern psychology, this centennial anniversary ...is an excellent opportunity to take stock of what Gestalt psychology has offered and how it has changed since its inception. We first introduce the key findings and ideas in the Berlin school of Gestalt psychology, and then briefly sketch its development, rise, and fall. Next, we discuss its empirical and conceptual problems, and indicate how they are addressed in contemporary research on perceptual grouping and figure-ground organization. In particular, we review the principles of grouping, both classical (e.g., proximity, similarity, common fate, good continuation, closure, symmetry, parallelism) and new (e.g., synchrony, common region, element and uniform connectedness), and their role in contour integration and completion. We then review classic and new image-based principles of figure-ground organization, how it is influenced by past experience and attention, and how it relates to shape and depth perception. After an integrated review of the neural mechanisms involved in contour grouping, border ownership, and figure-ground perception, we conclude by evaluating what modern vision science has offered compared to traditional Gestalt psychology, whether we can speak of a Gestalt revival, and where the remaining limitations and challenges lie. A better integration of this research tradition with the rest of vision science requires further progress regarding the conceptual and theoretical foundations of the Gestalt approach, which is the focus of a second review article. (Contains 24 figures and 6 tables.)
What factors constrain whether tool use modulates the user's body representations? To date, studies on representational plasticity following tool use have primarily focused on the act of using the ...tool. Here, we investigated whether the tool's morphology also serves to constrain plasticity. In 2 experiments, we varied whether the tool was morphologically similar to a target body part (Experiment 1, hand; Experiment 2, arm). Participants judged the tactile distance between pairs of points applied to their tool-using target body surface and forehead (control surface) before and after tool use. We applied touch in 2 orientations, allowing us to quantify how tool use modulates the representation's shape. Significant representational plasticity in hand shape (increase in width, decrease in length) was found when the tool was morphologically similar to a hand (Experiment 1A), but not when the tool was arm-shaped (Experiment 1B). Conversely, significant representational plasticity was found on the arm when the tool was arm-shaped (Experiment 2B), but not when hand-shaped (Experiment 2A). Taken together, our results indicate that morphological similarity between the tool and the effector constrains tool-induced representational plasticity. The embodiment of tools may thus depend on a match-to-template process between tool morphology and representation of the body.
Despite decades of research, little is known about how people visually perceive object shape. We hypothesize that a promising approach to shape perception is provided by a "visual perception as ...Bayesian inference" framework which augments an emphasis on visual representation with an emphasis on the idea that shape perception is a form of statistical inference. Our hypothesis claims that shape perception of unfamiliar objects can be characterized as statistical inference of 3D shape in an object-centered coordinate system. We describe a computational model based on our theoretical framework, and provide evidence for the model along two lines. First, we show that, counterintuitively, the model accounts for viewpoint-dependency of object recognition, traditionally regarded as evidence against people's use of 3D object-centered shape representations. Second, we report the results of an experiment using a shape similarity task, and present an extensive evaluation of existing models' abilities to account for the experimental data. We find that our shape inference model captures subjects' behaviors better than competing models. Taken as a whole, our experimental and computational results illustrate the promise of our approach and suggest that people's shape representations of unfamiliar objects are probabilistic, 3D, and object-centered.
The research is devoted to the study of the actualization of meanings in a literary text. The study is based on the material of a medieval novel. The subject of the study was the corpus of texts of ...chivalric novels. In the aggregate, the study of (linguistic-rhetorical) works. The analysis was carried out from the position of studying the author's strategy of influencing the reader in order to have a certain attitude to the hero or plot of the work. The author's influencing strategy in novels is conceptually different from the strategies in works of other genres. The fact that in the works of different authors, united by one image of the main character, use similar elements of influence on the reader, which indicates a special perception of the image of the main character in the minds of people of the XII–XV centuries. This perception is formed both from the totality of literary techniques that pass from work to work, and at the level of linguistic means.
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