dont cross the streams!

Many Shuvs and Zuuls knew what it was to be roasted in the depths of the Slor that day, I can tell you!





A team from University College London finds that when we gaze around in a poorly-lit context, it can fool our brains into seeing things that are not really there.

In the journal PLoS Computational Biology, Prof Li Zhaoping and her colleagues say that the context surrounding what we see is all important - sometimes overriding the evidence gathered by our eyes and even causing us to imagine things.

They were surprised to find that a vague background context has more influence on what we see than one that is bright and well defined, and speculate that this might explain the power of some abstract art and why we can see vivid details in the vague brush strokes of impressionist paintings.

"Everything we see is an hallucination generated by the virtual reality machine inside our head," comments Prof Mike Morgan of The City University, London.

"Normally these hallucinations are vetoed by the information coming through our senses, so we can call perception 'controlled hallucination.'

"But when the input is ambiguous we can see all sorts of things, like the faces de Quincy saw in clouds and carpets. There are hundreds of faces hidden in the textured floors of the platforms at Euston Underground Station, if you look for them."

To reveal the haunting power of context, 18 observers were asked by the UCL team to concentrate on the centre of a black computer screen. Every time a buzzer sounded they pressed one of two buttons to record whether or not they had just seen a small, dim, grey 'target' rectangle in the middle of the screen. It did not appear every time, but when it did appear it was displayed for just 80 milliseconds (80 one thousandths of a second).

"People saw the target much more often if it appeared in the middle of a vertical line of similar looking, grey rectangles, compared to when it appeared in the middle of a pattern of bright, white rectangles. They even registered 'seeing' the target when it wasn't actually there," says Prof Zhaoping.

source: http://www.telegraph.co.uk/earth/main.jhtml?view=DETAILS&grid=&xml=/earth/2008/02/21/scighost121.xml