reference stimuli

例句：

1. 1. Researchers use reference stimuli to study the effects of drugs on the brain.
   研究者使用参考刺激物来研究药物对大脑的影响。
2. 2. The scientist used reference stimuli to help the patient recover faster.
   这位科学家使用参考刺激物帮助病人更快地恢复。
3. 3. The researchers found that the reference stimuli were effective in treating the patient's condition.
   研究人员发现，参考刺激物在治疗患者病情方面是有效的。