Scientific

Abstract: We present the EchoEye, a sonar-based obstacle detection device we have developed to protect visually impaired travelers from upper-body obstacles that may not be detected by a cane or guide dog. The EchoEye prototype is worn on the head and warns the user about nearby upper-body obstacles by providing vibration feedback when these obstacles are near.  

Abstract: The two eyes are yoked, and yet the visual inputs are disparate in space and time. How the brain works on these disparities to achieve unitary perception is one of the fundamental questions in neuroscience. In this talk, I will first discuss temporal disparity that presumably underlies normal and clinical perceptual phenomena, such as the Pulfrich effect and visual symptoms in patients with optic neuritis. Recent experiments in my lab demonstrated neural signatures of interocular inhibition in visual evoked potentials when asynchrony was introduced in binocular visual stimulation. Second, I will focus on torsional disparity between the eyes. While studied much less than other types of spatial disparity, it is of substantial scientific and technological significance: 1)      Given the importance of orientation tuning in the visual cortices, torsional disparity leading to orientation mismatch between the two retinae compli- cates the correspondence problem in binocular summation and suppression. 2)      It poses one of the most challenging issues in virtual reality technology, such as head-mounted displays (HMD), since torsion differs between the two eyes in vergence, due to the binocular extension of Listing’s law. Investigations in my lab have shown that this indeed is a significant factor in neurologic side effects of HMD. Ways to understand and study the impact of torsion and/or temporal disparities on perception and oculomotor kinematics will be discussed.   Host: John Brabyn

 Abstract:  Accessing scientific content within digital documents is often challenging for people with visual impairments. Text information can be easily accessed by the means of assistive tools such as refreshable braille displays or screen readers. However, mathematical formulae or graphs are difficult to translate into an accessible form while preserving the expressiveness of the original format. Providing accessible content is a burden left to document authors, which requires substantial time and effort. Document authors are also frequently unaware of the need for document accessibility, and they may not have the required know-how to create accessible documents. Thus, scientific content is rarely provided in an accessible format, which creates a barrier for access to STEM education and employment for people with visual impairments.   At laboratory “S. Polin” of the University of Turin, Italy, our research focuses on assistive technologies to enable the access to digital documents with scientific content for people with visual impairments. I will present two of our most recent works: Axessibility is a LaTeX package for generating PDF documents in which mathematical formulae are accessible to people with visual impairments using braille displays or screen readers, without requiring the author to add accessible content manually. AudioFunctions.web is a web-based system that enables blind people to explore mathematical function graphs, using sonification, earcons and speech synthesis to convey the overall shape of the function graph, its key points of interest, is accurate quantitative information at any given point. 

Abstract: Infants’ and children’s brains undergo a large amount of change throughout development. These changes lead to improvements in visual and cognitive abilities – such as visual functions and the ability to pay attention or encode events to memory. During this Brown Bag, I will present the developmental research I completed during my graduate studies, focusing on my Master’s thesis and PhD dissertation work. For my Master’s thesis, I used the Visual Expectation Paradigm (Haith et al., 1988) to study memory in infants. Infants’ anticipatory eye movements were measured on 2 consecutive days. On day 1, infants were trained to form expectations and make anticipatory eye movements based on the predictable color and spatial location of visual stimuli. On day 2, they were presented with either the same stimuli, or different stimuli which varied by color or location. I will present the results and discuss how visual expectation processes are related to mechanisms of memory in infancy. My PhD dissertation examined spatial attention-modulated surround suppression during development. In adults, previous research has demonstrated that a suppressive field is present surrounding a spatial location of attentional focus. This results from top-down attention promoting the processing of relevant stimuli and inhibiting surrounding distractors (Tsotsos, 1995; Hopf et al., 2006). The goal of my dissertation was to examine how this phenomenon manifests in children and adolescents. I will present data proposing that top-down attentional processes are likely still maturing until approximately 12 years of age. https://ski.org/users/audrey-wong-kee-you