Neural Basis of Binocular Vision and Amblyopia PDF

Neural Basis of Binocular Vision and Amblyopia 30 January 2024 15:44 Main Ideas Notes What is amblyopia? Referred to as lazy high Highly prevalent (~3% of population) Notes EEG responses - Baker et al. (2015) Steady-state visual evoked potentials (SSVEPs) to measure contrast response functions of am...

Neural Basis of Binocular Vision and Amblyopia 30 January 2024 15:44 Main Ideas Notes What is amblyopia? Referred to as lazy high Highly prevalent (~3% of population) Notes EEG responses - Baker et al. (2015) Steady-state visual evoked potentials (SSVEPs) to measure contrast response functions of amblyopic (N=10) and control (N=5) observers, to flickering stimuli Results Input to one eye is disturbed during development Strabismus (squint – effects ~50% of cases) Results showed a monocular response that increases monotonically with increasing contrast level Anisometropia (difference in refractive power) Ptsosis (drooping of the eye lid) Cataract (clouding of the lens) Clinical definition of at least a two-line difference between the eyes Critical period for treatment to be effective (~ 7 years old) Notes Contrast response functions Binocular tr By adju artificia Over tim suppre Also a significant reduction in response amplitude for the amblyopic eye compared to the fellow eye Plot of left is an fmri study and on right is from a monkey simple cell Vision with two eyes vs. one eye Visual sensitivity is improved when viewing through two eyes compared to one eye Binocular vision Healthy vision This advantage of binocular vision is defined as the ‘binocular summation ratio’ (BSR) Healthy vision: A monocular stimulus needs to be presented at a contrast 1.4 ( √2) - 2 times higher than a binocular stimulus to be equally detectable (Baker, Lygo, Meese, & Georgeson, 2018) Amblyopia: Binocular summation is negligible in amblyopia (BSR =