In behavioral and motion research, pieces of equipment for measuring electro-physiological signals, kinematics and video are generally used separately. For motion analysis, various types of equipment for recording kinematics and physiological signals in concert are available from several manufacturers. In our department, the combined recording and analysis of video and physiological data for behavioral research has been used since the mid-1980s.

Researchers in the fields of movement sciences and developmental neurology have long wished to merge motion and behavioral analysis with physiological data. The electrical activity of trunk and limb muscles, respiration, heart action, eye movements and the electrical activity of the brain have all been mentioned as valuable in behavior and motion analyses. These electro-physiological signals represent the neural drive and control of the behavioral system. For maximum flexibility, two options have been implemented for recording physiological data: (i) stationary recording, by means of a fibre optic data-link between the front-end acquisition and the data-recording computer; and (ii) an ambulant system, which records the data at the front-end. The temporal relationships between the signals should, of course, be preserved.

This system allows data input from three sources, each with its own specific data rate: (1) video, at 25 (30) or 50 (60) frames per second (fps); (2) kinematics, from six cameras measuring multiple (up to 24) sets of coordinates at either 50 (60) or 100 (120) per second (cps); and (3) up to 128 channels of physiological data, at a sampling rate of 200 to 2000 Hz. A sync generator synchronizes the digital video camera and the kinematics cameras (which are in essence also video cameras). The digital video camera is connected to the data-recording computer by means of an i-link, which converts video frame number data into a time-code signal. Transmitting this time-code signal from the recording computer to the front-end by means of a radio link synchronizes the data at the front-end. The time-code data is sampled as an extra data channel at the front-end, and either sent over the fibre link with the physiological data (in the stationary mode) or recorded at the front-end (in the ambulant mode). The kinematics data, time-code and (if recording stationary measurements) the physiological data are then transported to the main computer over a 100 MHz Local Area Network.

Paper presented at Measuring Behavior 2002 , 4^th International Conference on Methods and Techniques in Behavioral Research, 27-30 August 2002, Amsterdam, The Netherlands

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