【雙語(yǔ)版】什么是恐懼條件實(shí)驗(yàn)？/恐懼制約 What is Fear Conditioning?
恐懼條件實(shí)驗(yàn)的內(nèi)容為聯(lián)想式學(xué)習(xí)任務(wù)[1]，不了解條件反射實(shí)驗(yàn)的，可以參照
在實(shí)驗(yàn)中，首先對(duì)實(shí)驗(yàn)對(duì)象（小鼠）施加條件刺激（響聲）和非條件刺激（電擊）的組合，以使小鼠習(xí)得該條件刺激，表現(xiàn)出條件反射（驚嚇后的停滯、靜止）。
其次，通過將實(shí)驗(yàn)對(duì)象置于不同環(huán)境（通常為兩種），設(shè)置不同的刺激組合，以條件反應(yīng)的出現(xiàn)頻率等來(lái)判斷恐懼本身的習(xí)得與消失。
該實(shí)驗(yàn)常用來(lái)檢測(cè)某種藥物的效果，或研究特定腦區(qū)對(duì)恐懼反應(yīng)的影響。[2]
流程大致如下：
第一天，在環(huán)境1（訓(xùn)練環(huán)境）中，小鼠被施加條件刺激和非條件刺激的組合，刺激間存在時(shí)間間隔。
第二天，在環(huán)境2（光源，地板材質(zhì)等不同）中，僅施加條件刺激。
第三天，小鼠重新被安置于環(huán)境1，不施加任何刺激。
在此過程中，習(xí)得的條件反射常是完全的靜止不動(dòng)，且持續(xù)超過一定時(shí)間。三天內(nèi)的條件反射都會(huì)被記錄。
除了恐懼條件實(shí)驗(yàn)，還存在延遲恐懼條件實(shí)驗(yàn)，二者的區(qū)別在于后者施加兩種刺激時(shí)，中間無(wú)時(shí)間間隔。
Fear Conditioning FC is a type of associative learning task, in which the subject (mice) learnt to associate stimulus by?paired Conditional Stimuli CS (a tone) and Aversive?Unconditional Stimuli US (mild electric shock), and this lead to its Conditional Response CR.
The mice is placed in different context. By recording the CR in different context with different set of stimuli, we can analyse how the learning goes of certain aversive stimuli.
The FC is often used to test certain drugs or to research on the process of learning fear for particular brain area.
The protocol usually goes as follows:
on the 1st day, the mice is put in Context A (also called the Training Context), and undergoes paired US (shock) and CS (tone), with the US occurs some time after the CS.?
on the 2nd day, the mice is put in Context B (different floor texture or light source), and would be stimulated with CS alone.
on the 3rd day, the mice is put in Context A again with no?stimuli.
During this process, the CR is usually defined as Freezing, a complete lack of motion which lasts longer than 0.75s. The CR in different context is recorded for further analysis.
Other than FC, there is also one called Delayed FC. The difference is that in the latter one, there is no time between US and CS.
參考：
[1] Fear Conditioning, https://med.stanford.edu/sbfnl/services/bm/lm/bml-fear.html
[2] Klein et al, .
