Description:

Sensory deprivation models as a gateway to study the brain and cognition

Abstract:

What forces guide brain organization, perception development, and plasticity? When a brain region is deprived of its typical input, what dictates its function? What does this teach us about the content of the underlying representations that our cognitive system and brain have of the external world?

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 association visual cortex organization, and for its object-level representations. Instead these data suggest that these regions pertain to perceptual-cognitive computations which appear to be abstracted from their specific sensory or motor components. The organization of these cortical regions is highly dependent on innate (prenatal) constraints reflecting computational/domain preferences. Network organization in the early topographic cortices also develops in the blind and deaf, raising questions about the role of sensory experience during developmental critical periods. Lastly, sensory-deprived populations can be used in studying conceptual representations independent of sensory referents. This enables disentangling factors of sensory associations and objecthood, revealing a division of labor between medial, dorsal and lateral aspects of left anterior temporal lobe in representing different properties of concepts.

Sensory-deprived populations can thus serve as models to address cognitive questions at multiple levels of representation, supporting a view of a-modal, domain-based concept organization and brain structure. These findings also open new questions of the applicability of this model to effector-independent organization in the action system, the ability to use it for motor rehabilitation, as well as the developmental processes in its basis.