A Macintosh-based system performs stimulus control and data acquisition, and an off-line analysis, in experiments on visually driven neurons in frog. The stimulus is a target moved on a modified XY recorder. The computer is equipped with a multifunction input/output board to perform stimulus control and data acquisition. The graphical programming system LabVIEW 2 was used to develop the 'Vision 93' package made of 4 main 'virtual instruments' (VIs). By means of DOCS-Exp, the user controls the experiment via screen displays which look like front panels of electronic instruments. DOCS-Preproc performs a user-controlled spike detection and computes mean impulse rate values. DOCS-SAS displays the instantaneous frequency, mean impulse rate, spike counts or interspike time intervals as staircase histograms and/or spline smoothed curves. Finally, DOCS - x - Functions computes and graphs quantitative stimulus/response relationships in terms of velocity, diameter, orientation and configuration of the target. The functionalities of these main VIs are presented and original software components are detailed. System operation is illustrated by using the successive VIs to process a sample signal record.
