Question

Motor control requires a lot of coordination and fine-tuning for smooth and coordinated movement. Explain 1 example of FEEDFORWARD control and 1 example of FEEDBACK control in the motor control system.

Answer 1

ANS :Motor control is the regulation of movement in organisms that possess a nervous system. Motor control includes reflexes as well as directed movement.To control movement, the nervous system must integrate multimodal sensory information (both from the external world as well as proprioception) and elicit the necessary signals to recruit muscles to carry out a goal. This pathway spans many disciplines, including multisensory integration, signal processing, coordination, biomechanics, and cognition,

Feedback control :In a feedback controller, a desired output is compared continuously with the actual output, and adjustments are made during the execution of the movement until the actual movement matches the desired movement.Feedback control enables the motor system to react to sensory input that indicates deviations form the planned movement. In contrast to local feedback control, the defining feature of coordinative feedback control is that motor commands to one effector depend on sensory feedback from another effector. Such dependency can, for example, be observed in the reaction of the shoulder in responses to perturbations of the elbow, or in the reaction of one hand in response to perturbations of the other.

Feebforward control :Coordination is also achieved in a predictive, feed-forward manner. For example, to make a successful reaching movement, the muscular activity around the shoulder joint needs to be tightly coordinated with the muscular activity around the elbow joint to compensate for the interaction torques and to ensure a straight reaching trajectory. The term “synergy” is often introduced to explain coordination across different muscles. As a descriptive term, a synergy simply refers to the strong regularities in the spatiotemporal pattern of muscle commands, and the observation that large portions of the variance of recorded muscle activity can be described by a small number of linear components