Fig. 2.
Stimulus preprocessing and reconstruction. The mechanics of the receiver's ear extract the slow amplitude modulation s(t) of a rapidly oscillating sound-pressure wave w(t). Auditory receptor neurons then encode s(t) into the membrane voltage V(t). As a first step of the stimulus reconstruction, the spike train y(t) is extracted from the voltage trace. Within linear reconstruction, each spike is then replaced by an optimal filter function to yield sest(t), the estimate of s(t). As shown by this example, stimulus reconstruction does not aim at recovering the original, complete physical stimulus w(t) but instead requires the identification of a representation of the stimulus that is relevant for the animal, in the present case the AM signal s(t).