What can we learn about brain organization from people born blind, deaf or without hands?
How does being born blind, deaf, or without arms, affect brain structure and function? Does our brain depend on sensory information during critical developmental periods for its formation?
I present studies conducted on a group of congenitally blind people using sensory substitution (a transformation of images into sounds) and on a different cohort, of people born without hands, which show that no single sensory or motor system is critically required for visual cortex organization. Instead these data suggest that cortex organization is highly dependent on innate constraints and computation preferences. Hints for similar principles can be found in the auditory cortex. These findings will be discussed with reference to the model of a-modal brain structure and its limitations regarding critical periods and plasticity.