5.1 How conscious are we?
Try this quick test of concentration before moving on.
Activity 4
Take a look at this video – paying close attention – then reveal the discussion below.
Count the passes [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] (open the link in a new window/tab so you can return here easily)
Discussion
So, this wasn’t a test of concentration after all! If you saw the gorilla straight away, you might wonder how anyone could possibly miss it. But in fact, about half of people don’t see it.
(By the way, if you already knew about this ‘invisible gorilla’, you may like to try this one out – open the link in a new window tab so you can return here easily.)
The point here isn’t to show how inadequate our brains are, but rather how remarkable they are. Imagine we were equally aware of every detail in our field of vision, along with all the sounds or sensations around us, every bodily movement we make, and all our thoughts on top of that – the experience would be utterly overwhelming. It’s not that our eyes couldn’t detect the gorilla, but that our brains ‘decided’ it wasn’t important enough to tell us about it, knowing the particular task we were already engaged in. Our brains are equipped to filter out unwanted sensory input like this. They make a lot of unconscious decisions for us!
This can materialise in various ways. Perhaps you’ve experienced the sensation of driving home and finding you can’t then remember the journey. Or maybe you’ve had a sudden flash of inspiration for a problem you’d been trying to solve hours before. There is a great deal going on inside our brains that we don’t directly know about.
Another remarkable example of the brain’s independence is a very unusual condition known as ‘blindsight’. Particular damage to the brain causes people with this condition to think they are blind. However, tests show that their brain can process some visual information and respond to it. For example, when visually exposed to a threat they will react physically, but without the accompanying feeling of being afraid. They can actually see without conscious awareness. This shows that different regions of the brain are responsible for different aspects of ‘seeing’. It seems that only the more recently evolved regions allow for conscious experience.
The question of whether consciousness has an evolutionary advantage is keenly debated. Our brains could still sense our environment and respond to it without us feeling anything. Perhaps it allows us to envisage outcomes for ourselves based on our actions – it helps us to plan ahead. On the other hand, it may just be a by-product of evolutionary brain development.