Final answer:
Shifting control to lower levels of the sensorimotor system during training leads to faster reactions and greater efficiency in executing movements, as well as fine-tuned precision by comparing motor commands and sensory feedback, which is crucial for tasks involving dexterity and coordination.
Step-by-step explanation:
The two advantages of shifting control to lower levels of the sensorimotor system during training are improved efficacy and efficiency. First, when control is shifted away from higher cognitive processes, it allows for faster reactions as lower levels of the motor system can generate responses more quickly without the need for conscious thought. Moreover, engaging lower levels of the sensorimotor system leads to a greater degree of automation, which can facilitate multitasking as the higher cognitive processes are freed up to focus on other tasks. This is particularly evident in associating sensory stimuli with learned behavior, such as when an athlete performs a well-rehearsed move instinctively.
Second, shifting control to lower levels can enhance precision as those levels, including the cerebellum and the spinal cord, are specialized in comparing motor commands and sensory feedback. This specialization ensures that movements are fine-tuned and adjustments are made in real-time to maintain balance or adjust to environmental changes. Such processes are central to activities requiring high levels of dexterity and coordination, like playing a musical instrument or executing complex maneuvers in sports.