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Stare at the illusion below, let your eyes wander ever so slightly and you'll notice how the spinning circles and dots seem to spontaneously change direction.

From one angle, the spots spin anticlockwise, from another they appear to switch direction - and moving your eyes across the two circles causes a number of different movements to occur.

In reality, the circles do not change direction at all though - it's all an illusion.

When looking directly at a ring above, our brains notice the motion of the spots, not the stripes inside the spots. As a result the circles move anticlockwise. When looking at a ring in the peripheral vision, the brain processes the motion of the stripes, and the circles move in the same direction, which in this instance is clockwise

The optical illusion is so famous, neurologists, psychologists and philosophers have been studying why these visual 'changes' seem to occur for years.

Named Rotating Reversals, the trick was originally presented at the Society for Neuroscience conference in 2008. 

It has been developed and adapted in various guises by Washington-based researchers Professor Arthur Shapiro, Professor Peter Meilstrup, Professor Emily Knight and Professor Zhong-Lin Liu.

More recently, it was posted to Google+ by John Baez at the Centre for Quantum Technologies at the University of California, Riverside.

According to Professor Meilstrup, writing on Mr Baez's post, there are two sources of visual motion present in the illusion.

This includes the circles themselves, and stripes within each circle - known as what's called 'first' and 'second order' motions.

The black and white stripes in the spots move around an axis, and these spots move around the central dot.

The stripes on the left-hand, or red, side are moving in the same direction as the spots. 

But on the right-hand, or yellow, side the stripes and spots move in opposite directions.

'In first order motion, a light feature in one frame moves to and matches a light feature in the next frame, or a dark spot changes position but still remains a dark spot,' explained Professor Meilstrup.

When looking at the Rotating Snake illusion (pictured), a similar visual experience is created. This illusion was created by Professor Akiyoshi Kitaoka, from Ritsumseikan University, in Kyoto, Japan and it comes with a warning on his website, due to the feeling of nausea it could cause some viewers

'However, if the visual system just matched light stripes to light stripes and dark stripes to dark stripes, you wouldn't see the movement of the spots.'

To see the spots move, humans are able to detect that the black and white stripes, or the areas of high and low contrast, are moving. 

Professor Meilstrup continued that our brains devote more attention and processing power to the image that is in the centre of our vision.

Called Rotating Reversals, the illusion was originally presented at the Society for Neuroscience conference in 2008 and has adapted by Washington-based researchers including Professor Arthur Shapiro. This sliding image reveals how changing the contrast between the dots and the background also changes its motion

By contrast, objects on the periphery of our vision are compressed to make sure they are visible through the visual cortex.

As Professor Meilstrup explained: 'So as you switch from looking directly at the yellow spot to viewing it peripherally, you are switching from an, uncompressed to a compressed view.'

This means that looking directly at a ring of circles, our brains notice the motion of the spots, and not the stripes, and as a result the circles move anticlockwise.

In this instance, the stripes appear to flicker rather than move.

However, when looking at a ring in the peripheral vision, the brain process the motion of the stripes within the spots, and the circles appear to move in the same direction as the stripes, which in this instance is clockwise.