This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sensory System, Subject name: Physiology
Like other sensory systems, the somatosensory system has a descending component that functions to regulate the overall sensitivity of the system. Which of the following selections best describes the function of the coicofugal signals transmitted from the somatosensory coex downward to the thalamus and dorsal column nuclei? 
Select and explain. 
A. Increase or decrease the perception of signal intensity, B. Decrease the ability to detect body position sense, C. Remove the thalamus from the processing of somatosensory signals, D. Allow ascending information to bypass the nucleus cuneatus and gracilis
A: Increase or decrease the perception of signal intensity
Answer: A: Increase or decrease the perception of signal intensity 
Explanation: Descending coical modulation of somatosensation involves in increase or decrease in the perception of signal intensity.