 Something that we've been trying to emphasise in this section to the course and something that is important to becoming a better thinker is a recognition to the fact that human cognitive capabilities are significantly constrained in their functioning and thus our thinking is often subject to flaws. As we've talked about, what we perceive of as reality is largely an illusion constructed by our brains. Visual perception is highly filtered and constructed by our mind. Memories are not only constructed but reconstructed every time we access them. Our brains create patterns to information and assign meaning to those patterns then abstracts away from the impression to build larger, more complex patterns. The end product is that our sense of the world around us and ourselves is primarily a construct of our brains. Our perceptions are not passive. There are many ways in which the brain constructs these perceptions. In fact, our brains actively construct a picture of what is going on around us based upon a tiny fraction of all the sensory information that is received. This results in the opportunity for many potential errors, manipulation and distortion in the end product that we often unknowingly assume to be reality. Optical illusions are one example of this, representing times when objects either are not stable or are not aligned with the broader physical context. This results from the fact that the brain has to make assumptions about what is likely to be true. Those assumptions are then used to process sensory information. Typically those assumptions are accurate but when they're not correct the result is an optical illusion. When our brain is constructing our perception of our environment it will introduce lines or connections where it thinks they should be based upon a set of assumptions about what it thinks it should be seeing. Our brains will compare different types of sensory input in order to construct one seamless picture. Irrespective of the data provided it will adjust one sense or the other in order to make things match without one being aware that the original sensory data is not matching. For example when we look at someone clapping their hands the two events of what we see and hear appear to be simultaneous to us when in fact because light travels faster than sound the two events of what we see and hear happen at different times. This is a constructed illusion in our brains which is working in the background to synchronize the two events because it knows that they should be occurring at the same time. As long as the visual and auditory information is within 80 milliseconds of each other the brain will construct them as being simultaneous. One of our strengths as cognitive beings is making connections between different events, ideas, visual patterns or other phenomena. Human cognition is so well designed to see patterns that we sometimes see patterns that are not even present. Brain processing is based largely on pattern recognition most likely because of its underlining structure as a neural network. Attention is very significant to our construction of reality because we are constantly overwhelmed with a vast amount of sensory information and it is not possible to pay attention to even a significant fraction of it at any given instance. As a result we place a huge filter on most of the sensory information that reaches us and pay attention to only what our brains see as being important. We actually pay attention to a very small subset of the available information which we manufacture into a complete account by adding pieces of information as needed. The end result is a story that is largely constructed by our brains altered based upon comparison with what others believe and subject to manipulation in order to reduce cognitive dissonance making it conform with our beliefs and expectations. Likewise human memory is very much flawed in its workings like our perception our memory is not a passive recorder instead our memories are constructed entirely by our brains. In fact they are very much conditioned and contingent upon what we're thinking, feeling and our overall sense of reality at that time. In a study conducted by Ian Skernick and colleagues in 2007 the researchers showed that as many as 27% of young adults incorrectly remembered a false statement as being true only three days after they were told it and this increased with age 40% of older adults misremembered a false statement as being true. They remembered that they had heard the statement before but they did not remember that it was false. We attend to a very small subset of information which we weave into a complete story by adding constructed pieces as needed. The end result is a story that is largely a product of our cognitive workings where sensory input is constructed into meaningful patterns. Not only are the components of what we perceive constructed but also how we put our perceptions together into a meaningful way is also constructed. Recognizing these innate fallibilities in human cognition is an essential step towards effective critical thinking.