Dramatic neurological deficits may emerge due to brain damage or deafferentation of sensory input to the brain. These deficits result from disruption to the normal state of interactions between areas within the neural network. The traditional view is that the majority of neurons and connections are laid down early in life, and although some will later adapt, few will be created beyond early childhood. It is not clear whether experience can provoke substantial changes in functional patterns and wiring of the adult brain, and whether any such changes involve the recruitment and strengthening of existing functional areas and pathways, or include genuinely new properties not otherwise present. Understanding the intrinsic abilities and limits of the nervous system to repair itself after damage has enormous clinical significance.
We study processes of cortical reorganization in the adult human brain following cases of peripheral and cortical lesions to the visual system. These include lesions along the retina, optic nerve, chiasm, post-chiasmal pathways and the hierarchal organized areas in the visual cortex. We study questions of spatial reorganization that compensates for a reduced amount of visual information arriving at the cortex (Levin et al., Neuron 2010, Raz et al., JNNP 2010), as well as temporal reorganization that compensates for the delayed arrival of visual information to the cortex (Levin et al., AAN abstract 2013).