Analysis of the frequency response of the saccadic circuit: numerical simulations

Fundamental mechanisms of a brain circuit's operation can be revealed by qu antitative analysis of the system's dynamic behavior. This approach is part icularly useful for investigation of motor circuits, which generate machine -like outputs and where systems control techniques can be applied to reveal the circuit behavior outside the dynamic range of volitional activation. A s an extension of our previous study of the step response of the saccadic m otor system, this paper presents analytical and numerical considerations fo r the frequency response of the saccadic circuit-the system response to a s teady-state sinusoidal input. Consideration of these responses provides mec hanistic explanation for several aspects of the biological circuit and form alizes constraints for viable models of the saccadic circuit. Most importan tly, these studies provide quantitative predictions for comparison with exp erimental data in vivo and make explicit hypotheses about biological mechan isms for experimental verification. (C) 2001 Elsevier Science Ltd. All righ ts reserved.