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."
因為我們剛剛告別了舊的一年,所以我們非常熟悉“后知之明”。但是你聽說過盲視么?
盲視現(xiàn)象是指在不用大腦視覺功能器官去真正看東西的情況下,仍然看得見的能力。猴子被證實具有可以在空間中移動的盲視能力,但是到目前為止,還沒有發(fā)現(xiàn)人具備這種能力。
最近《當代生物》(Current Biology)的一篇文章報道了一個中風后失明的病人,中風使他失去了視皮層(大腦中處理視覺輸入的區(qū)域)。他的眼睛和視神經仍然完整無損,研究者們證實該病人通過他仍然完好的眼睛收集一些信息。
研究者們于是給這個盲人做了一個測試。在許多人看來,對于一個盲人來說,這個測試幾乎是不可能完成的。在沒有拐杖的情況下,這個盲人需要繞過一些椅子和盒子穿過大廳。
他非常順利地通過了測試。這就意味著視覺信息可以不通過視皮層而是經由其它途徑達到大腦。也就是說,我們并不一定需要意識到看的體驗去獲取以及處理視覺刺激。
Beatrice de Gelder是該項研究中的作者之一,他說:“我們隨時都在利用我們大腦隱藏的資源,做一些我們認為我們不可能完成的事情。”
對于那句老諺語“我看見了,盲人說”,看來我們需要給它新的含義了。
Vocabulary:
Hindsight: 后知之明;事后聰明
Blindsight: 盲視
Navigate: 航行;使通過
Visual Cortex: 視皮層
Intact: 原封不動的;完整無損的
Cane: 拐杖
Stimuli: 刺激