Retinotopic remapping of the visual system in deaf adults

Abstract

Deaf individuals rely on visual rather than auditory cues to detect events in the periphery, putting a greater demand on neural resources for vision. Comparing visual maps in the brains of early deaf and hearing adults, we found a redistribution of neural resources in the lateral geniculate nucleus and primary visual cortex, with larger representations of the periphery, at a cost of smaller representations of the central visual field.

Short-term plasticity in the visual thalamus

“…However, since parvocellular layers cover the largest majority of the LGN volume, this system should dominate BOLD signals from the LGN region; nevertheless, we found no systematic BOLD modulations with monocular deprivation. Of course, this does not imply that LGN lacks plasticity potential, which may well emerge in other contexts or participants (Castaldi et al, 2016;Jaepel et al, 2017;Levine et al, 2020;Mikellidou et al, 2019;Rose & Bonhoeffer, 2018) or during a stabilization of the short-term plasticity effect, as observed for repeated monocular deprivations in amblyopia (Lunghi et al, 2019). While we cannot exclude that plasticity is possible in LGN, the fact that vPulv responses clearly changed after monocular deprivation in the same dataset where LGN showed no modulation suggests that short-term plasticity effects in LGN, if present, are small or inconsistent.…”

“…The Lateral Geniculate Nucleus (LGN) receives the largest contingent of retinofugal fibers, and it is the main source of feedforward signals to V1 (Blasdel & Lund, 1983;Hendrickson et al, 1978;Hubel & Wiesel, 1972). In humans, there are indications that LGN can shift function following sensory deprivation (Levine et al, 2020;Mikellidou et al, 2019) or restoration (Castaldi et al, 2016). In rodents, plasticity of lateral geniculate nucleus neurons was recently reported (Jaepel et al, 2017;Rose & Bonhoeffer, 2018;Sommeijer et al, 2017).…”