Take a look at the picture below. Which of the horizontal lines is longer?
This picture is the famous Ponzo Illusion. The lines are the same length. How did you respond to that question? Did you
- trust what you saw and say that the top line was longer
- think back to a similar illusion that you’ve seen in the past and assume that the lines were the same
- measure the lines to find out for sure
- consider alternative ways to look at and make sense of the image
The first two are probably representative of how we approach many things. We trust our assumptions and senses without verification. That can get us in trouble. The second two represent good critical thinking.
This illusion illustrates a very simple idea: our senses may not be as accurate as they seem. We often rely heavily on what we sense – after all “seeing is believing”, right? It’s reasonable to trust our sense. They are a deeply ingrained part of who we are. But, as the illusion demonstrates, senses can deceive us.
Actually, it’s not our senses that are deceiving us, it is our brain. Senses are just input devices just like microphones or video cameras. It’s the way that those inputs get processed which creates problems. What we “see” isn’t just a simple record of the image that entered our eye. It is influenced by our past experiences and what we’ve seen before. A recent research study showed that when an image enters your eye, two parts of your brain become active. The first is the part responsible for generating the image. The second is the part assocaited with your memory. That’s why family resemblances are often more obvious to strangers than they are to family members. Strangers just see the actual features. Family members “see” all of the stories, experiences, and meaning behind those features which makes each family member appear much more unique.
It’s easy to feel certain about our perceptions because they often seems so real. Those lines in the illusion really look different, don’t they? But don’t be fooled. Our brain dictates everything that we perceive whether it be through sights, sounds, smells, or even thoughts.
Recent discoveries in neuroscience have shown that by the time we become conscious and aware of anything, our brain has already applied several layers of “meaning” to it. Sometimes that meaning is real, other times, like with this illusion, our brains distort it. And, we can’t stop it. Look at the lines again. You know that they are the same yet you cannot stop your brain from making you see them as different.
So, the next time you feel certain about something that you are seeing, hearing, or thinking, remember that it might just be a very convincing illusion created by your brain. You might want to turn to some external source to validate your perceptions.
Brad,
Great post! I agree. What we find so many times in six sigma is that the data challenges our assumptions and we find that what we “know” isn’t true at all. One of the most significant challenges to improvement efforts is getting over our own biases. Its very difficult to fully realize the limits of our knowledge and recognize, with humility, that we don’t know something that we thought we knew.
Hey Chief: Great post. I’m glad you opened the door to this discussion!
I just want to be the devil’s advocate for a minute here and suggest that there’s good reason for our perceptions of optical illusions like the one above. Our bodies exist in space, and we negotiate 3 dimensional spaces all the time. We have to know if a door is wide enough to get through or if a bluff is too steep to safely climb. The reason our perceptions “seem so real” and that “we often rely heavily on what we sense” is because our survival depends on it. Moreover, what we make of what we sense is often right on. So, memory is a good thing. An illusion like yours above is an exception to the kinds of visual cues we process in the spaces we inhabit, no? So, I wouldn’t say that our brains are “deceiving” us as much as they may be cautioning us.
Indulge me please, for another minor rant. The idea that our brains are somehow alien, deceptive, “out to get us” has become a trope in contemporary popular discourse. And, you seem to be holding up THE BRAIN as a distinct and separate entity from our bodies and our minds–pushing the Cartesian myth of a mind-body dichotomy to an extreme. I wonder why. Our language offers us so many ways to represent “the brain”–yet, we seem to want to position it in a very particular way. I think that doing so is problematic, mechanistic, and, well– short-sighted. No doubt it’s part of a vast, right-wing conspiracy 🙂
Our brains function in complex ways, this is true, but wouldn’t you agree that we see with our brains, and brains work in concert with our bodies? My brain is my mind; my mind is me. Most of the time, I can make pretty good decisions about how to negotiate my context. So, can’t my brain be my friend?
I agree that most of the time our senses do make sense. In our book we make a similar point. Probably 90-95% of the time our brains lead us down the right path. The problem is that we don’t always know when 23 are in the 90-95% scenario or the 5-10% scenario. As a result, we sometimes get lulled into a sense of security and certainty since things generally turn out ok.
Our point is just that we need to be mindful of the fact that this other 5-10% exists and is very hard to discern.
I think that the dichotomy we are creating by separating brain from body is mostly just to make people mindful of what is going on in their mind (that sounds ironic). Again, it’s probably an overexaggeration but I think that such a separation is important to get us into the habit of stepping back and questioning what we are experiencing, even when that expereince comes from within – especially when it comes from within.
The integration of brian, mind, body, and self is truly remarkable. But, if left completely unchecked, it can get us in trouble even if it works out ok most of the time.