• Question: I understand that when we see things are brain picks it up upside down but why does are brain do this?

    Asked by Jess to Barbara, Matt, Ravinder, Sophie, Tristan on 15 Mar 2015. This question was also asked by jamjarjarvis.
    • Photo: Barbara Shih

      Barbara Shih answered on 15 Mar 2015:

      When light travel through the lenses in our eyes (or in cameras), they bend (change directions they move in, known as refraction), which is why the images are projected onto our retina upside down.
      (A little more about refraction and lenses: http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/visiblelight_solarsystem/telescopesrev1.shtml).

      I couldn’t find an exact reason why brains are evolved to adapt to flip the image back the right way round, other than that it’s probably more advantagous. This adaptation is also seen experimentally- in experiments where subjects wore glasses that flip what the subject see the wrong way round for several days, brains are able to adapt and flip the images back. The brain does a lot of image/visual manipulation that allow us to interact with our enviroment efficiently. This is quite a good video that describes so examples of them if you’re interested. https://www.youtube.com/watch?v=ZflIMBxyIak

    • Photo: Matthew Moore

      Matthew Moore answered on 19 Mar 2015:

      Probably for coordination! So as the light is refracted it ends up, upside down, if everything else works assuming our feet are at the bottom then it would be easiest to coordinate movement in the same orientation, rather than everything having to be signalled in opposite (like when you look in the mirror and your left arm seems to be on the right hand side).

      Otherwise, there would be no problem with the world being upside down! We wouldn’t know any different

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