The nation's psychology teachers had a noticeable spring in their step last week after cognitive
neuroscientist and Mind Hacks author
Dr Tom Stafford of the University of Sheffield showed them the power of interactive demonstration. The Research Digest was lucky enough to be in the audience.
Moments into the keynote talk, the teachers and I found ourselves blinded by darkness. As our eyes adjusted, we were told to cover one eye with our hands before the lights were raised again. A little wait for our open eyes to become light-adjusted and then the lights re-dimmed. What would happen to our vision this time? The answer depends on whether adaptation to light levels occurs centrally, in the brain, or locally in each eye. The audience tested this, looking through each eye one at a time and discovering the strange experience of having one eye adapted to the light and one to the dark, thus showing that light adaptation occurs locally. Both eyes open led to a strange, grey, grainy, effect. “Whoever said psychology isn't useful is wrong,” Stafford said. “You now have the perfect strategy for visiting the toilet in the night and finding your way back to your bed in the dark.”
Light adaptation may well occur locally, but what about adaptation to motion? A huge video of a waterfall filled the screen. After a minute staring at the cascading water, the video was stopped and the audience experienced the well-known illusion of the water appearing to flow upwards. But what if the flowing water was watched with just one eye (with the other covered), with the paused video then observed through the previously covered eye? The illusion was still experienced, thus showing that in this case, adaptation to motion had occurred centrally, in the brain.
Here we were, an audience of several hundred, asking questions and finding answers about the organisation of the human brain, all from the comfort of our seats. “The wisdom of psychology,” Stafford said, “is as a way of finding things out and generating facts. Everyone can take part.”
“I'm now going to rewire your brains,” Stafford continued, “by fostering your expectations.” Led Zeppelin's Stairway to Heaven began to fill the lecture room. Then a verse was played backwards (courtesy of
Jeff Milner). Could we hear any words in the backward version? None. But then Stafford told us the hidden lyrics: “Oh here's to my Sweet Satan...”. The backward track was played again, and there the words were, bold, impossible to ignore. Visit the site and see for yourself. “Hours of fun or moral panic, depending on your perspective,” Stafford said.
Once the expectations for what to hear are in place, they can't be undone. You can't
unhear the devilish lyrics once you know about them. This is a powerful demonstration of how our perceptual experiences are based not just on what is served up by our senses, but also on what our brains bring to the table.
“Examples like these teach us that we all have access to the raw materials of psychology,” Stafford said, “but that we can't necessarily trust them. Yet with sceptical enquiry and careful investigation, we can find out how the brain works.”
译文:
黑夜中也能找到从厕所回来的路……
在来自谢菲尔德大学的著名的神经学家汤姆.斯坦福博士兼MIND HACKS的作者展示了相互示范所产生的力量之后，上周心里学家们迎来了一次飞跃。观众非常有幸与这项研究的摘要见面。
让我们快速进入主题，老师和我发现在黑暗中时我们是失明的。当我们眼睛适应了黑暗，我们被告知在灯亮之前用手捂住一只眼睛。一会，我们睁开的眼睛适应光亮以后，灯光将重新变暗。这时我们的视力将发生什么变化？
适应光亮也许会在局部发生，但是这是否会适应于移动的物体呢？一个巨大的瀑布出现在屏幕上，几分钟后，注视着这条瀑布，影像停止，观众感受到那熟悉的瀑布的错觉，似乎在向上流淌。但是如果用一只眼睛观看那流淌的水（一只眼睛闭上），利用停顿的影像然后通过先前闭上的眼睛观看会是怎样的？这种错觉仍然是经验造成的，因此在这种情况下，对于移动物体的适应能力生在头脑的中央部位。
在这，成百上千中的一个观众，问了一个关于人脑构成的问题，斯坦福说“心理学明智之处在于它是利用一种方式去发现问题并阐明事实，每个人可以参与其中”
“我将要重新构架你们的大脑”，斯坦福接着说，“利用培养你们的希望” 莱德·泽普林通向天堂的道路铺满了讲堂。接着倒着朗诵一首诗歌，在这个版本中我们能听懂任何词语么？不能，但是斯坦福博士告诉我们难以发现的诗歌：“哦。给我亲爱的撒旦……”在倒着念一遍，然后词语变粗，不能被忽视。自己游历下这些地点，此时间的快乐和恐慌，取决自己的看法。斯坦福说。
一旦这种期望是适合的，他们将很好的完成。你不能沉寂于特别的诗歌中一旦你了解他们。这是一个很有力的证明，我们有知觉的干感受不是基于我们感官提供的，而是在我们头脑中体现的。
“像这样的例子告诉我们，我们有权使用心理上的元素”斯坦福说，“但我们不能完全相信它”然而带着质问和仔细的研究，我们会找到大脑工作的原理。