Given that we just said goodbye to another year, we are all pretty familiar with the hindsight. But have you heard of blindsight?

The phenomenon is the ability to see without having the visual brain hardware to actually see. It’s been proven that monkeys have blindsight for navigating through a space, but never in a human, until now.

A recent paper in Current Biology describes a patient who lost his ability to see after suffering strokes that wiped out his visual cortex, the brain area that processes visual input. His eyes and optic nerves remained intact, and the researchers confirmed that some information was being gathered via his still-functioning eyes.

So they gave him what many would think was the impossible test for a blind person. He had to navigate a hallway, around chairs and boxes, without his cane.

He passed the test perfectly. What this implies is that visual information can reach areas of the brain, by routes other than the visual cortex. Meaning, we don’t have to be conscious of the experience of seeing to capture, and respond to, visual stimuli.
“All the time, we are using hidden resources of our brain and doing things we think we are unable to do,” said Beatrice de Gelder, one of the authors.

Gives new meaning to the old saying: "I see, said the blind man."

因为我们刚刚告别了旧的一年，所以我们非常熟悉“后知之明”。但是你听说过盲视么？

盲视现象是指在不用大脑视觉功能器官去真正看东西的情况下，仍然看得见的能力。猴子被证实具有可以在空间中移动的盲视能力，但是到目前为止，还没有发现人具备这种能力。

最近《当代生物》（Current Biology）的一篇文章报道了一个中风后失明的病人，中风使他失去了视皮层（大脑中处理视觉输入的区域）。他的眼睛和视神经仍然完整无损，研究者们证实该病人通过他仍然完好的眼睛收集一些信息。

研究者们于是给这个盲人做了一个测试。在许多人看来，对于一个盲人来说，这个测试几乎是不可能完成的。在没有拐杖的情况下，这个盲人需要绕过一些椅子和盒子穿过大厅。

他非常顺利地通过了测试。这就意味着视觉信息可以不通过视皮层而是经由其它途径达到大脑。也就是说，我们并不一定需要意识到看的体验去获取以及处理视觉刺激。

Beatrice de Gelder是该项研究中的作者之一，他说：“我们随时都在利用我们大脑隐藏的资源，做一些我们认为我们不可能完成的事情。”

对于那句老谚语“我看见了，盲人说”，看来我们需要给它新的含义了。

Vocabulary:

Hindsight: 后知之明；事后聪明
Blindsight: 盲视
Navigate: 航行；使通过
Visual Cortex: 视皮层
Intact: 原封不动的；完整无损的
Cane: 拐杖
Stimuli: 刺激