The last time someone told you to look at an optical illusion, they probably described it as playing a cool trick on your eyes. But these quirks of perception – as well as most other illusions – have more to do with tricking your brain than anything else.
Rather than thinking about illusions as being something you fall for, scientists have realized that these mis-perceptions are actually powerful glimpses into the work that the brain typically seems to do so easily. In fact, some well-known illusions linked to sights and sounds have such a strong foundation in our brains that they can still affect people who have been blind or deaf since birth.
The obvious question is why we are even susceptible to illusions in the first place. If our brains and senses have developed specifically to help us interpret and navigate the world around us, why is there this room for error? The answer, at least in part, is efficiency.
First we need to make a distinction between sensation – the information sent to our brains from our senses – and perception – the meaning that the brain assigns to this input.
Read the whole story: Scientific American