Electrocortical and hemodynamic measures reliably identify enhanced activity in the ventral and dorsal visual cortices during the perception of emotionally arousing versus neutral images, an effect that may reflect directive feedback from the subcortical amygdala. However, other brain regions strongly modulate visual attention, such as frontal eye fields (FEF) and intraparietal sulcus (IPS). He...

The effects of aging on motion perception in healthy older adults Lia E. Tsotsos Doctor of Philosophy Department of Psychology, Neuroscience and Behaviour McMaster University 2012 Motion perception is required for nearly all aspects of daily living. It is fundamental to our ability to move within, and interact with, our dynamic environment. Previous work has shown that the ability to perceive a...

Monitor is a portable vibrotactile aid to improve the ability of people with severe hearing impairment or deafblindness to detect, identify, and recognize the direction of sound-producing events. It transforms and adapts sounds to the frequency sensitivity range of the skin. The aid was evaluated in the field. Four females (44-54 years) with Usher Syndrome I (three with tunnel vision and one wi...

This work is intended to provide some ideas on the use of a Gaussian-derivative model for visual perception, called the Hermite transform, to extract motion information from an image sequence. Gaussian-derivative operators have long been used in computer vision for feature extraction and are relevant in visual system modeling. A directional energy is defined in terms of the 1-D Hermite transfor...

Several different directional anisotropies have been found in global motion perception. The purpose of this study was to examine the role of the motion sensitive cortical area V5/MT+ in directional anisotropies for translational flow fields. Experiments 1 and 2 tested direction discrimination and detection of moving random dot patterns. When the speed of motion was 8 deg/s, lower coherence thre...

Directional selectivity refers to a neuron’s ability to produce substantially different responses for stimulus motions of different direction. A directionally selective (DS) cell will fire many spikes in response to object motion in one direction (the preferred direction) while responding weakly, if at all, for motion in the opposite (null) direction. This directional “trigger feature” is often...

The quantitative (or fuzzy qualitative) assessment of directional spatial relationships (such as “to the right of”, “above”, “south of”...) between two areal objects often relies on the computation of a histogram of angles, which provides a representation of the relative position of the objects. In a recent paper, the notion of the histogram of forces was introduced. Here, we show that this pow...

There has been a considerable interest in the development of human-like image perception systems. Although a number of algorithms have been proposed so far, it is still a challenging task to achieve a human-like robustness in image perception under various circumstances. For robust image perception, the feature representation algorithm which extracts essential features from an image and represe...

This paper is a description of recent advances in off-line signature verification research performed at our laboratory. Related works pertain to structural interpretation of signature images, directional PDF used as a global shape factor, the Extended Shadow Code (ESC) and the fuzzy ESC, a cognitive approach based on the Fuzzy ARTMAP, and shape factors related to visual perception.

In this work we consider development of IR-based communication and perception mechanisms for real microrobotic systems. It is demonstrated that a specific combination of hardware and software elements provides capabilities for navigation, objects recognition, directional and unidirectional communication. We discuss open issues and their resolution based on the experiments in the swarm of micror...