| Popis: |
Publisher Summary The fact that the impulses from skin receptors and proprioceptors of the hand are transmitted via oligosynaptic pathways to separate clusters of cells within area 4 of the motor cortex indicates a distinct functional link between the peripheral input and the cortical output. Nevertheless, precise knowledge about the mode by which hand muscles are controlled by peripheral inputs is missing. Neither is it known which part is played by the spinal stretch reflex, which has not been abandoned completely even in intrinsic hand muscles, nor is it agreed whether the proposed transcortical reflex acts in a “servo-like” or a “triggered” fashion. A quantitative approach was used to study the balance in gain between the spinal stretch reflex and the “long-latency” reflex. Sinusoidal analysis was chosen, because this technique provides estimates of gain and loop time of a feed-back system in operation. In the oculomotor system, sinusoidal analysis has been successfully applied to study the transfer function of various reflexes, which made it possible to describe some of the investigated subsystems in mathematical terms. It is shown in the chapter that in the skeletomotor system, sinusoidal analysis can also provide data, which may be used as a first building block of a quantitative description of the reflex control of hand muscles. |
