OK. Can you show me the task?
好的，你能给我看一下实验吗？
Yeah.
当然可以。
When volunteer lies in the scanner, this is what he sees.
当志愿者躺在扫描仪下时，他们会看到这个。
He sees an arrow pointing right or left, and he is asked to press the button right or left accordingly.
他会看到一个指左边或右边的箭头，按要求他就要按方向对应的按钮。
And then occasionally there will be an arrow pointing upwards, and he is asked not to press the button.
有时会突然出现一个向上的箭头，他就什么按钮都不按。
Stop himself from...
抑制自己...
So in a sense he is asked to do nothing?
就是说他什么都不要做？
That's right. He is asked to stop himself from pressing the button.
是的，他要控制自己不按按钮。
And this was the particular bit of the task that we were interested in.
这是实验比较特别的一点，也是我们最感兴趣的部分。
And this is how we put the brakes on...
这也就是我们所说的停止按钮...
Yeah. I guess that sort of braking is the sort of control over behaviour that we do all the time.
我想所谓的停止按钮，也就是我们日常行为的控制器，对吧？
Yeah.
是的。
So Zerrin gave this task to volunteers, inside a brain scanner.
洁琳对躺在脑部扫描器里面的志愿者进行试验。
Each of them had received THC equivalent to smoking one joint.
所有的志愿者都服用了相当于一根大麻烟含量的THC。
She then repeated the experiment with a placebo for comparison.
然后她又对使用安慰剂的对象试验，并进行对比。
What she was looking for was the brain activity in each group as they tried not to press the button in response to the up arrow.
她要找的是每组人看到向上箭头时，他们尝试不去按按钮的脑部活动。
This is the average of 15 volunteers.
这是15个志愿者的平均结果。
And this is the placebo condition, basically this is the normal situation.
这是使用安慰剂那组的结果，基本上属于正常的状况。
So this is the normal brain responding to that task.
这是正常人脑的实验结果。
Yeah, normal brain.
对的，正常人脑。
Yeah. As you can see, certain areas are looking red there which are activated, and that is the pre-frontal cortex.
对。正如你所看到，有一部分是红色的，那表示大脑的前额叶处活跃的部分。
And this is what you would expect in a normal situation, when we are stopping yourself from doing something.
这就是正常情况下，当我们要停止做一些事时的结果。
And this is the average of again 15 people this time who have taken THC, cannabis.
而这则是使用了THC，也就是大麻的15位志愿者的平均结果。
And what you see, very clearly, that in fact the normal areas are not working, there's no activity.
你能明显的看到，正常情况下活跃的区域并没有活动，它们罢工了。
Zerrin believes that the inactivation of these frontal areas of the brain,
洁琳相信，脑前叶也就是理解周围环境的部分，
which interpret our surroundings, might explain some effects of cannabis such as paranoia.
它这种不活跃的状态，可以对大麻的一些影响作出解释，如妄想症。
