Why We Do What We Do

chapter sixOur Brain and Visual Perception

‘All things are subject to interpretation.’

FRIEDRICH NIETZSCHEPhilosopher, critic, poet and philologist (1844–1900)

ABOUT THIS CHAPTER

Our eyes take in most of the information that comes into our brain. We cannot deal with every single visual input that we receive and so our visual perception is a continuous process of filtering, selecting and interpreting what we see.

In order to make sense of what we take in through our eyes, our brain uses its store of knowledge, beliefs, experiences and expectations as a reference guide. This means that we tend to screen in visual information that supports our view of the world, and screen out information that contradicts it. In effect, we see what we want and expect to see.

Visual processing is a key cognitive process in the brain. This chapter explains how our brain perceives visual information and constructs what we know as our reality.

Part 1: The science explained

How do we see?

Our vision accounts for two-thirds of the electrical activity of the brain, and half of our neural tissue is directly or indirectly related to vision.¹ Vision is so dominant in the brain that it can affect, distort or even overwhelm our other senses.

FIGURE 6.1: How our brain sees

Our ability to take in visual information depends on two of our organs: 1) our eyes to receive visual stimuli and 2) our brain ...