Semi-on-line implementation of an alias-free sampling system for neuronal signals

Spectral analysis of neuronal impulse trains is complicated by the extensive bandwidth of such signals which makes regular sampling in time difficult because of frequency aliasing. A program is described which uses a new method of sampling neuronal impulse trains by treatment of the impulses with an ideal digital filter to prevent such aliasing. The program uses the Digital Equipment Corporation LAB-8 Computer and performs the digital filtering at the same time as it is observing the impulses and a simultaneous analog voltage which normally constitute the input and output signals of a neural receptor or effector system. The program is an addition to the spectral analysis package of programs described previously by the same authors.