A vivid perception of the moving form of a human figure can be obtained from a few moving light points on the joints of the body. This is known as biological motion perception. It is commonly believed that the perception of biological motion rests on image motion signals. Curiously, however, some patients with lesions to motion processing areas of the dorsal stream are severely impaired in imag...

We investigated the perception of local surface orientation on a simple smooth object, under several different illumination conditions. The perceived local orientation was determined for several points on the surface and quantified as slant and tilt of the local tangent plane. We found an underestimation of the perceived slant and a larger variance for the perceived tilt than for the perceived ...

This study reexamined the perceptual equivalence of active and passive touch using a computer-controlled force-feedback device. Nine subjects explored a 6 x 10-cm workspace, with the index finger resting on a mobile flat plate, and experienced simulated Gaussian ridges and troughs (width, 15 mm; amplitude, 0.5 to 4.5 mm). The device simulated shapes by modulating either lateral resistance with ...

The ability to derive the facing direction of a spatially scrambled point-light walker relies on the motions of the feet and is impaired if they are inverted. We exploited this local inversion effect in three experiments that employed novel stimuli derived from only fragments of full foot trajectories. In Experiment 1, observers were presented with stimuli derived from a single fragment or a pa...

With a sample of Italians selected from 71 Italian counties (N = 1,868), we performed two multilevel analyses aimed at predicting the perceived risk of crime at local (i.e., in the participants' county of residence) and at societal (i.e., in the context of Italian society) levels. A significant proportion of the variation in local risk perception was at the county level. The following individua...

It is clear that texture plays an important role in both human perception and machine vision tasks and, at the global scale of perception, may be regarded as a carrier of region information, Bovik et al. (1). However, since real-world surface textures are very di cult to model mathematically, no exact de nition exists. Therefore, ad-hoc approaches to the analysis of textures have been used, inc...

The combination of electrophysiological recordings with ambiguous visual stimulation made possible the detection of neurons that represent the content of subjective visual perception and perceptual suppression in multiple cortical and subcortical brain regions. These neuronal populations, commonly referred to as the neural correlates of consciousness, are more likely to be found in the temporal...

Point-light walkers have been useful to study the contribution of form and motion to biological motion perception by manipulating the lifetime, number, or spatial distribution of the light points. Recent studies have also manipulated the light points themselves, replacing them with small images of objects. This manipulation degraded the recognizability of biological motion, particularly for loc...

Humans are able to detect blurring of visual images, but the mechanism by which they do so is not clear. A traditional view is that a blurred image looks “unnatural” because of the reduction in energy (either globally or locally) at high frequencies. In this paper, we propose that the disruption of local phase can provide an alternative explanation for blur perception. We show that precisely lo...

Various demonstrations show that a target of constant luminance can be made to appear darker in perceived lightness merely by introducing an adjacent region of higher luminance. This has often been interpreted as a manifestation of contrast effects produced by lateral inhibition, a relatively local process. An alternative interpretation holds that the highest luminance in such a display serves ...