The laws and principles which predict how perceptual qualities can be extracted from the most elementary visual signals were discovered by the Gestalt psychologists(e.g., Wertheimer,1923; Metzger,1930, translated and re-editedbySpillmann in 2009 and2012, respectively). Their seminal work has inspired visual science ever since, andhas led to exciting discoveries which have confirmed the Gestalt idea that the human brain would have an astonishing capacity for selecting and combining critical visual signals to generate output representations for decision making and action. This capacity of (...) selection and integration enables the perception of form and space, and the correct estimation of relative positions, trajectories, and distances of objects represented in planar images. This paper addresses problems of perceptual organization with critical implications for visual interfaces, and the design of surgical simulator platforms in particular. (shrink)

Apparent motion is an illusion in which two sequentially presented and spatially separated stimuli give rise to the experience of one moving stimulus. This phenomenon has been deployed in various philosophical arguments for and against various theories of consciousness, time consciousness and the ontology of time. Nevertheless, philosophers have continued working within a framework that does not reflect the current understanding of apparent motion. The main objectives of this paper are to expose the shortcomings of the explanations provided for apparent (...) motion and to offer an alternative explanation for the phenomenon. (shrink)

Summary In recent years, the concept of simplicity in perception has acquired a leading role, above all thanks to scholars linked to Bayesian modeling and to theories like structural information theory derived from information theory. Unfortunately, two misleading ideas made their way into the discussion: that in perception, simplicity is equivalent to Prägnanz and that Occam’s razor plays a role in the simplicity of percepts. Here it is shown that in Gestalt theory, simplicity is only one of the factors of (...) Prägnanz and that the use of Occam’s razor is improper, because it applies only to the theories that generate, in this case, a percept, and not to the product of the theory. (shrink)

Human articulated motion can be readily recognized robustly even from impoverished so-called point-light displays. Such sequence information is processed by separate visual processing channels recruiting different stages at low and intermediate levels of the cortical visual processing hierarchy. The different contributions that motion and form information make to form articulated, or biological, motion perception are still under investigation. Here we investigate experimentally whether and how specific spatio-temporal features, such as extrema in the motion energy or maximum limb expansion, indicated by (...) the lateral and longitudinal extension, constrain the formation of the representations of articulated body motion. In order to isolate the relevant stimulus properties we suggest a novel masking technique, which allows to selectively impair the ankle information of the body configuration while keeping the motion of the point-light locations intact. Our results provide evidence that maxima in feature channel representations, e.g., the lateral or longitudinal extension, define elemental features to specify key poses of biological motion patterns. These findings provide support for models which aim at automatically building visual representations for the cortical processing of articulated motion by identifying temporally localized events in a continuous input stream. (shrink)