Jisu Kang¹, Daniel Dilks¹; ¹Emory University

When input to a region of adult primary visual cortex (V1) is removed, creating a scotoma, neurons within the deprived region begin responding to stimuli that normally activate adjacent cortex only. In typically sighted individuals, this reorganization can occur within minutes of reversible deprivation and produces a perceptual distortion: a square flashed for 150 ms next to the scotoma is seen as a rectangle stretching into it. Although such rapid reorganization has been linked to changes in GABA-mediated inhibition, little is known about adult V1 reorganization after decades of deprivation. To investigate long-term deprivation, we tested three one-eyed individuals whose V1 regions corresponding to the intact eye’s natural blind spot had been deprived for over 30 years. With brief stimulus presentations (150 ms), long-term deprivation produced the same magnitude of stretching seen after short-term deprivation. But with longer presentations (750 ms) a key difference emerged: the distortion persisted only after long-term deprivation, not short-term deprivation. The persistent perceptual distortion may serve as a behavioral maker of structural – rather than purely functional – reorganization in adult V1 as a result of long-term deprivation.