Functional principles of whisker-mediated touch perception

In the progression of events wherein the rodent whisker sensory system constructs a percept of the world around the animal, neurons exercise distinct functional roles; here we review recent progress in our understanding of the principles for response organization in the system. The whisker’s mechanical properties and anchoring to the follicle shape the forces transmitted to specialized receptors. The sensory and motor systems are intimately interconnected, giving rise to two forms of whisker-mediated sensation: generative and receptive. The sensory pathway exemplifies fundamental concepts in computation and coding: hierarchical feature selectivity, sparseness, adaptive representations, and population coding. The central processing of signals can be considered a sequence of filters. At the level of cortex, neurons represent object features by a coordinated population code which encompasses cells with heterogeneous properties.