ACTOGRAPHY BY IMAGE-PROCESSING

The technique of actography by image processing results from the assoc iation of two methods : quantification of motor activity and video rec ording of behavior. The major technical advantage is that only one par ameter is recorded : the video image which can be processed in two dif ferent ways, on-line or off-line for actimetry and for a behavioral st udy. Commercial equipment is used to detect sensitive areas in an imag e by use of sensors markers. Any motion modifies the contrast in certa in parts of the image. If these areas are superimposed with the sensor s markers, motion is detected, and a binary signal is generated which can be picked-up by a micro-computer. After presenting the main techni cal characteristics of this method, the authors assess the accuracy of results obtained using video-recorders operating at normal speed or s low motion, in daylight and under infra-red lighting. An exemple of ap plication of this technique is reported in the third part of this pape r. It concerns the behavioral analysis of wake and sleep in rhesus mon keys restrained in restraining chairs in order to test the efficacy of new psychotropic drugs in neuropharmacology.