O is for Optical illusions

| April 14, 2014

What is the sense you rely on the most? As you are sitting on your chair and sensing your surroundings, what is it that allows you to say with certainty that you are in fact in your room, sipping on your coffee in front of your computer? Most of us will reply; vision!

Humans are predominantly visual creatures. Indeed, 50% of our brain is devoted to visual processing. But can we really say for sure that our sight is providing us with information that completely matches reality? Can we really trust our eyes? I wouldn’t be so sure.

Let me show you a couple of optical illusions in order to illustrate my point;

This one here is called the Munker-White illusion:

All of the gray bars are actually the same color gray. The lightness difference you are experienceing is a massive illusion. An explaination of what is underlying the lightness illusion is provided by a theory which describes the effects of context on color appearance (i.e. Bars in column A seem darker as surrounded by black, bars in columb B seem ligter as surrounded by white).

This idea of context dependency makes a whole lot of sense. All things occur in context. Hence, in order for us interact with our environment in a successful manner, we must understand things in context. As humans, the role of our perceptual apparatus is to extract information from our surroundings and integrate and interpret it in a way that facilitates a successful interaction. As a result, our perception is biased. And this is for our own good, because if we could perceive all the colors, sounds, all of the properties of matter in their full and vivid “realness”, the resulting aesthetic experience would leave us baffled and overwhelmed.