4. 다음 글의 주제로 가장 적절한 것은?
preferred music listening has been shown to lead to enhanced control over, and effective distraction from, pain-inducing stimuli under laboratory conditions, when compared with non-preferred or experimenter-selected music. similar effects in reducing pain, anxiety and agitated behavior have been found both in clinical settings and in chronic pain in everyday life settings. listening to preferred music rather than experimenter-chosen music or silence produces a lower heart rate and perceived exertion and fatigue rates, and improves cognitive performance in driving simulation tasks. thus listening to preferred music has powerful effects on aspects of behavior outside voluntary control as well as on mood and affect. in these cases, the nature of the musical stimulus has no bearing whatsoever on the effects.

전체적인 글의 주제에서 마지막 문장의 의미가 도대체 어떻게 이해해야 할까요?