This work, performed by means of time-resolved high-resolution birefringence measurements, establishes the switching mechanism of electrically commanded surfaces _ECS_ for liquid-crystal displays. A distinct polar electro-optic response, due to the field-induced in-plane switching of the molecules of the 200-nm ferroelectric liquid crystalline polysiloxane alignment layer representing ECS, was detected in a cell filled with isotropic liquid _hexadecane_. The similarity between this response and the one reported recently in cells containing the same ECS but with a nematic liquid-crystal bulk with negative dielectric anisotropy (Delta-epsilo
