unconditioned stimulus

基本解释

What's the unconditioned stimulus?
什么是无条件刺激？
The conditioned response is a preparation for the unconditioned stimulus.
条件反应是对无条件刺激的一种准备。
A reinforced trial is when the conditioned stimulus and the unconditioned stimulus go together.
强化尝试是指条件刺激,与无条件刺激同时出现的时候。

So, the idea here is, repeated pairings of the unconditioned stimulus and the conditioned stimulus will give rise to the response.
这里的意思是说，无条件刺激与条件刺激的反复匹配,会引起条件反应。
耶鲁公开课 - 心理学导论课程节选
Now the pain of a bite, being bit, and then the pain and fear of that is an unconditioned stimulus, unconditioned response.
咬伤所带来的疼痛感，和有此所带来的痛苦与恐惧,就是无条件刺激和无条件反应。
耶鲁公开课 - 心理学导论课程节选
When Pavlov put food powder in the dog's mouth and saliva was generated, that's an unconditioned stimulus giving rise to an unconditioned response.
巴甫洛夫给狗喂食,狗会分泌唾液，这就是无条件刺激引起了无条件反应。
耶鲁公开课 - 心理学导论课程节选

any stimulus evoking an unlearnt response, esp in the context of classical conditioning, in which the conditioned stimulus is followed by the unconditioned one