Multi-whisker stimulation and its effects on vibrissa units in rat SmI barrel cortex.

Ceramic piezoelectric 'bimorphs' were used to construct multiangular mechanical stimulators which are small enough to attach to separate, adjacent vibrissae on the mystacial face pad of rodents. Use of two stimulators to independently deflect pairs of whiskers revealed that the responses of SmI cortical vibrissa units are determined by the direction in which both hairs are moved, the spatial sequence of the displacements, and the particular combination of whiskers that are stimulated. The stimulators can thus serve as the basic elements in a large array of independently controllable whisker deflectors.