Zoom Brown Bag: Excitatory and Suppressive Contribution to Binocular Interactions in Human Visual Cortex

Abstract:During binocular viewing, visual inputs from the two eyes interact at the level of visual cortex. In normal vision, visual inputs from the two eyes are balanced. However, in amblyopic vision, visual inputs from the amblyopic eye are reduced due to loss of visual acuity and contrast sensitivity. In this talk, I will present my recent lab work on how excitatory and suppressive interactions contribute to binocular contrast interactions along the visual cortical hierarchy of humans with normal and amblyopic vision, using source-imaged SSVEP and frequency-domain analysis of dichoptic stimuli over a wide range of relative contrast between the two eyes. A dichoptic contrast gain control model was used to characterize binocular interactions in amblyopia and provided a quantitative comparison to normal vision. Our model fits revealed different patterns of binocular interactions between normal and amblyopic vision. Strabismic amblyopia significantly reduced excitatory contributions to binocular interactions, whereas suppressive contributions remained intact. Our results provide robust evidence supporting the view that the preferential loss of excitatory interactions disrupts binocular interactions in strabismic amblyopia. https://www.ski.org/users/chuan-hou 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.)