时差N小时 什么是条件反射(下)（在线收听）

Once it reaches the spinal cord, the impulse is routed speedily back to the muscle originally stimulated.

一旦到达脊髓，神经冲动便会迅速返回至最初受到到刺激的肌肉。

This process occurs almost instantaneously, before we’ve even had time to consciously register that the reflex has happened.

整个过程几乎是在瞬间发生的，甚至在我们意识到之前，条件反射就已经发生了。

Although a reflex is automatic, it can change over time, depending on the regularity of the stimulus.

虽然条件反射是自发形成的，但它会随时间变化，这取决于刺激发生的频率。

If a stimulus is repeated continuously, the reflex first undergoes sensitization, meaning that it increases in response.

如果某种刺激在不断地重复，条件反射首先会对这种刺激变得敏感，预示着条件反射的反应次数会增加。

But if the stimulus is repeated beyond a certain point, the reflex begins to decrease until it disappears.

但如果这种重复性的刺激超过了某个点时，条件反射次数就会开始减少至消失。

In other words, you can tame a reflex by, for instance, hearing a sudden loud noise repeatedly until you stop jumping.

换句话说，条件反射是可以克服的，比如反复听突如其来的巨响，直到你不会被吓一跳为止。