Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Time and frequency domain methods for quantifying common modulation of motor unit firing patterns | Journal of NeuroEngineering and Rehabilitation BioMed Central Research Open Access Time and frequency domain methods for quantifying common modulation of motor unit firing patterns Lance J Myers 1 Zeynep Erim1 2 and Madeleine M Lowery1 2 Address Rehabilitation Institute of Chicago Sensory Motor Performance Program 345 East Superior St Chicago Illinois 60611 USA and 2Department of Physical Medicine and Rehabilitation Feinberg School of Medicine Northwestern University Chicago Illinois USA Email Lance J Myers - l-myers2@ Zeynep Erim - z-erim@ Madeleine M Lowery - m-lowery@ Corresponding author Published 14 October 2004 Received 30 August 2004 Journal of NeuroEngineering and Rehabilitation 2004 1 2 doi 1743-0003-1-2 Accepted 14 October 2004 This article is available from http content 1 1 2 2004 Myers et al licensee BioMed Central Ltd. This is an open-access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background In investigations of the human motor system two approaches are generally employed toward the identification of common modulating drives from motor unit recordings. One is a frequency domain method and uses the coherence function to determine the degree of linear correlation between each frequency component of the signals. The other is a time domain method that has been developed to determine the strength of low frequency common modulations between motor unit spike trains often referred to in the literature as common drive . Methods The relationships between these methods are systematically explored using both mathematical and experimental procedures. A mathematical derivation is presented that shows the theoretical relationship between both time and frequency domain techniques. .