March 2021
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Zoom Brown Bag: Visual dependence and visual-postural interactions in aging: from spatial orientation to postural control and navigation
Event Date:Abstract - Healthy aging is accompanied by a decline in many perceptual, cognitive, and motor abilities, which can lead to a loss of autonomy and health risks, most notably falls. Postural control and safe/successful navigation require the integration of sensory information (visual, vestibular and somatosensory), associated with multiple cognitive functions (e.g., attention, planning, memory). Among the factors contributing to daily living risks in older age, some may be associated with a degradation in sensory (re)weighting and a greater reliance on visual cues. Indeed, with older age, there is a greater reliance on visual feedback for postural control, especially with regards to the ground surface. This visual dependence, however, implies a lack of adaptability and often a sub-optimal exploitation of visual cues, given that older adults are also less able to ignore disorienting visual contextual information and to appropriately allocate and share attentional resources. Postural control is therefore an even greater challenge for older adults whilst in unfamiliar, complex, or dynamically changing environments.
In this talk, I will present findings from my doctoral and postdoctoral work on visual-postural interactions in aging, focusing on 1) perceptive and motor manifestations of visual dependence from young, to middle-aged, to older adults, and 2) the postural contribution to aging spatial cognition. I will discuss these topics in terms of individuals’ sensorimotor and cognitive profiles and with the perspective of rehabilitation/training to preserve autonomy in older age. https://www.ski.org/users/catherine-agathos
Improving Zoom accessibility for people with hearing impairments People with hearing impairments often use lipreading and speechreading to improve speech comprehension. This approach is helpful but only works if the speaker’s face and mouth are clearly visible. For the benefit of people with hearing impairments on Zoom calls, please enable your device’s camera whenever you are speaking on Zoom, and face the camera while you speak. (Feel free to disable your camera when you aren’t speaking.)
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Zoom Brown Bag: Macular Degeneration: Implications for scotoma overlap in the two eyes
Event Date:Abstract - I will describe two projects in the lab on functional vision in macular degeneration. Individuals with macular degeneration typically lose vision in the central region of one or both eyes. A binocular scotoma occurs when vision loss occurs in overlapping locations in both eyes, i.e. the intersection of the scotomata in the two eyes. To examine the consequences of a binocular scotoma, we carefully mapped out its extent, and measured accuracy and eye movements in a visual search task. Individuals with binocular scotomata had unique challenges (and adaptations) to visual search, while those with non-overlapping scotomas performed similarly to controls.
In another ongoing project we tested the prediction that stereopsis is impacted by the union of the two eyes’ scotomata. In other words, a scotoma in either eye will impact stereopsis, whether or not it is in a binocularly overlapping region. To test this hypothesis, we mapped the periphery with local disparity stimuli to compare functional stereopsis to the pattern of vision loss in each eye. Our results show that regions with impaired stereopsis are indeed consistent with the union of the scotoma in the two eyes.
Improving Zoom accessibility for people with hearing impairments People with hearing impairments often use lipreading and speechreading to improve speech comprehension. This approach is helpful but only works if the speaker’s face and mouth are clearly visible. For the benefit of people with hearing impairments on Zoom calls, please enable your device’s camera whenever you are speaking on Zoom, and face the camera while you speak. (Feel free to disable your camera when you aren’t speaking.)
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Zoom Brown Bag: Improving Vision Therapy for Binocular Dysfunction Through Performance Feedback
Event Date:Abstract - The prevalence of binocular dysfunction in the general population is greater than any other visual condition besides refractive error and is expected to increase in the coming years. Deficits in binocular coordination can disrupt learning, attention, and daily life. Current treatment approaches predominately require extensive clinical oversight and has been shown to be no more effective than a placebo.
In this talk, I will review two experimentally successful training paradigms for improving binocular coordination. Then argue that these paradigms target different underlying motor processes, fusion initiating and fusion sustaining vergence components, and that a novel combined protocol will be more effective at improving treatment outcomes. I'll also propose that such training can be enhanced through the use of real-time performance feedback and/or a task-relevant sensorimotor decision. Finally, I'll discuss how such a training protocol can take advantage of advances in eye tracking and display technology to be developed for both remote and widespread use. https://www.ski.org/users/brent-parsons Improving Zoom accessibility for people with hearing impairments People with hearing impairments often use lipreading and speechreading to improve speech comprehension. This approach is helpful but only works if the speaker’s face and mouth are clearly visible. For the benefit of people with hearing impairments on Zoom calls, please enable your device’s camera whenever you are speaking on Zoom, and face the camera while you speak. (Feel free to disable your camera when you aren’t speaking.)
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Zoom Colloquium: Identifying neural sub-systems underlying human stereopsis
Event Date:Abstract -The psychophysical and oculomotor literatures have long proposed that stereoscopic vision is served by multiple underlying subsystems. The subsystems are usually construed in terms of dichotomies, e.g patent vs qualitative, local vs global, first-order vs second-order, transient vs sustained, absolute vs relative, etc. Whether these multiple sub-systems are all independent is a matter of debate and moreover, there is very little known about their neural basis. Here I will describe recent work in which we attempt to unify two of the more prominent dichotomies — one spatial — absolute vs relative disparity and the other temporal — transient vs sustained. In a series of high-density EEG experiments using dynamic random dot stereograms that alternate between a flat plane and a stereo grating at 2 Hz, we find that odd harmonic components of the response reflect relative disparity extraction and that even harmonic components reflect absolute disparity extraction. Moreover, the odd harmonics reflect a sustained temporal mechanism, while the even harmonics reflect a transient mechanism. Taken together our results indicate that relative disparities are processed by sustained mechanisms while absolute disparity processing is transient in nature. https://profiles.stanford.edu/anthony-norcia
Improving Zoom accessibility for people with hearing impairments People with hearing impairments often use lipreading and speechreading to improve speech comprehension. This approach is helpful but only works if the speaker’s face and mouth are clearly visible. For the benefit of people with hearing impairments on Zoom calls, please enable your device’s camera whenever you are speaking on Zoom, and face the camera while you speak. (Feel free to disable your camera when you aren’t speaking.)
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Zoom Colloquium: The third dimension of eye movements: torsion and visual-vestibular integration
Event Date:Abstract - Whenever we tilt our head towards the shoulder our eyes partially compensate by rotating around the line of sight in the opposite direction. This combination of head tilt and torsional eye movements results in a tilted retinal image, while we nevertheless perceive the world as still and upright. I will present the development of a new method to measure torsional eye movements reliably, which has enabled us to study the relationship between torsion and perception in the lab and the effects of vestibular loss in the clinic. I will show how stimulating the temporo-parietal cortex can alter perception of upright without affecting torsional eye movements, confirming the role of this area in the multisensory process maintaining upright perception. I will also present how patients can reweight different sensory inputs after acute vestibular loss and how measuring torsion helps us understand the effect of strong magnetic fields on the vestibular system. https://vision.berkeley.edu/posts/welcome-dr-jorge-otero-milan https://optometry.berkeley.edu/people/jorge-otero-millan-phd/ Improving Zoom accessibility for people with hearing impairments
People with hearing impairments often use lipreading and speechreading to improve speech comprehension. This approach is helpful but only works if the speaker’s face and mouth are clearly visible. For the benefit of people with hearing impairments on Zoom calls, please enable your device’s camera whenever you are speaking on Zoom, and face the camera while you speak. (Feel free to disable your camera when you aren’t speaking.)
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Zoom Brown Bag: An Indoor Navigation System using Computer Vision and Sign Recognition
Event Date:Abstract - Indoor navigation is a significant challenge for people with visual impairments, who often lack access to visual cues such as informational signs, landmarks, and structural features that people with normal vision rely on for wayfinding. I will describe various approaches to recognizing and analyzing informational signs, such as Exit and restroom signs, in a building. These approaches will be incorporated in iNavigate, a smartphone app we are developing that provides accessible indoor navigation assistance. The app combines a digital map of the environment with computer vision and inertial sensing to estimate the user’s location on the map in real-time. These approaches can recognize and analyze any sign from a small number of training images to multiple types of signs be processed simultaneously in each video frame. When a sign is recognized in the environment, we can estimate the sign’s distance from the camera, which provides useful information to help iNavigate estimate the user’s location on the map.
https://www.ski.org/users/ali-cheraghi
Improving Zoom accessibility for people with hearing impairments People with hearing impairments often use lipreading and speechreading to improve speech comprehension. This approach is helpful but only works if the speaker’s face and mouth are clearly visible. For the benefit of people with hearing impairments on Zoom calls, please enable your device’s camera whenever you are speaking on Zoom, and face the camera while you speak. (Feel free to disable your camera when you aren’t speaking.)
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