Covert spatial attention alters the way things look. Objects situated at attended locations appear bigger, closer, if striped, stripier than qualitatively indiscernible counterparts whose locations are unattended. These results cannot be easily explained in terms of the number and kind of perceived properties of objects. Nor do they appear to be cases of visual illusions. Ned Block has argued t...

The aim of this article is to reinterpret the results obtained from the research analyzing the role played by spatial frequencies in face perception. Two main working lines have been explored in this body of research: (a) the critical bandwidth of spatial frequencies that allows face recognition to take place (the masking approach) and (b) the role played by different spatial frequencies while ...

In this paper we address the problem of f inding the spatial position and orientation of an object from a single image. It is assumed that the image formation process and an object model are known in advance. Sets of image lines are backprojected and constraints on their spatial interpretations are derived. A search space is then constructed where each node represents a space feature with a mod...

Bat echolocation is a dynamic behavior that allows for real-time adaptations in the timing and spectro-temporal design of sonar signals in response to a particular task and environment. To enable detailed, quantitative analyses of adaptive sonar behavior, echolocation call design was investigated in big brown bats, trained to rest on a stationary platform and track a tethered mealworm that appr...

Dealing with knowledge from the human natural environment is one of the most important capabilities that robotic systems should be equipped with to act autonomously. Moreover, a robot cannot perform a given task properly without knowing the meaning of the contained objects. In addition, semantic perception is very challenging and robots must be able to deal with uncertainties and ambiguities th...

Studies on adults have demonstrated that the perception our own body can be manipulated by varying both temporal and spatial properties of multisensory information. While human newborns are capable of detecting the temporal synchrony of visuo-tactile body-related cues, it remains unknown whether they also utilise spatial information for body perception. Twenty newborns were presented with a vid...

This paper reviews the perceptual and technical literature relevant to the generation of accurate acoustic displays for virtual environments. Beginning with an introduction to the process of human auditory perception, this paper critically examines common sound generation methods and techniques and discusses their advantages and disadvantages. The financial support of NSERC, NCE, IRIS, CRESTech...

This paper examines the role of spatial frequency and orientation tuned channels in the perception of visual symmetry. Subjects discriminated between band-pass filtered, white noise textures that either did or did not contain vertical bilateral symmetry (VBS, i.e., around a vertical midline) as a function of the spatial phase disruption imposed on the images. Resistance to phase noise is largel...

Previous studies have attempted to map somatosensory space via haptic matching tasks and have shown that individuals make large and systematic matching errors, the magnitude and angular direction of which vary systematically through the workspace. Based upon such demonstrations, it has been suggested that haptic space is non-Euclidian. This conclusion assumes that spatial perception is modality...

In order to enable the user of a virtual reality system to be fully immersed in the virtual environment, the user must be presented with believable sensory input. Although the majority of virtual environments place the emphasis on visual cues, replicating the complex interactions of sound within an environment will benefit the level of immersion and hence the user’s sense of presence. Three dim...