but what we really want to know is what's happening inside of the brain. 但我们真正想知道的是脑部内部的情形。

So we collaborate with Svein Kleiven's group in Sweden. They've developed a finite element model of the brain. 所以我们与瑞典的Svein Kleiven团队合作，他们研发出了一种脑部有限元素模型。

And so this is a simulation using the data from our mouthguard from the injury I just showed you, and what you see is the brain 这是一个模拟图，模拟所用数据，是刚才影片中那次受伤后我们从牙套中得到的数据，你会看到，

this is a cross-section right in the front of the brain twisting and contorting as I mentioned. 如我之前所述，脑部正前方左右脑交界处发生旋转、扭曲，

So you can see this doesn't look a lot like the CDC video. 所以这和CDC视频中所描述的并不一致。

Now, the colors that you're looking at are how much the brain tissue is being stretched. And so the red is 50 percent. 这里不同颜色所代表的是脑组织被拉伸的程度，红色代表百分之五十。

That means the brain has been stretched to 50 percent of its original length, the tissue in that particular area. 这意味着红色区域的这部分脑组织被拉长了原来长度的50%。

And the main thing I want to draw your attention to is this red spot. 值得注意的是红色点状区域的分布。

So the red spot is very close to the center of the brain, and relatively speaking,  它们非常接近脑部中心，相对而言，

you don't see a lot of colors like that on the exterior surface as the CDC video showed. 和CDC影片中所示不同，脑组织外部红色区域较少。

Now, to explain a little more detail about how we think concussion might be happening, 接下来，我会更详细地阐释我们对脑震荡成因的观点，

one thing I should mention is that we and others have observed that a concussion is more likely when you're struck and your head rotates in this direction 值得一提的是，我们和其他同行都观察到，如果头部被击打并像这样旋转，更容易造成脑震荡。

This is more common in sports like football, but this seems to be more dangerous. So what might be happening there? 橄榄球等运动中这种情况（前后晃动）更为常见，但这种（左右晃动）似乎更为危险。所以这种情况中脑部发生了什么呢？

Well, one thing that you'll notice in the human brain that is different than other animals is we have these two very large lobes. 值得注意的是，人类大脑与其他动物的并不相同，主要差异在于我们有两块儿相当大的大脑额叶。

We have the right brain and the left brain. 它们是我们的右脑和左脑。

And the key thing to notice in this figure here is that right down the center of the right brain and the left brain there's a large fissure that goes deep into the brain. 这幅图中值得注意的是，左右脑中间的正下方有一个深入脑组织的裂缝。

And in that fissure, what you can't see in this image, you'll have to trust me, there is a fibrous sheet of tissue. 虽然这幅图中看不到，但你得相信我，裂缝中有一层纤维化组织。

It's called the falx, and it runs from the front of your head all the way to the back of your head, and it's quite stiff. 它被称为脑镰，脑镰连通头部的最前方和最后方，它很硬。

And so what that allows for is when you're struck and your head rotates in this left-right direction,  当你头部被击中并左右旋转时，

forces can rapidly transmit right down to the center of your brain. 脑镰可以让受力迅速传至脑部中央。