What are Memories?
Our development is based upon the creation of memories, a complex, brain-wide process that is essential to who we are. Our brains constantly receive sensory inputs from our environment in the form of sight, sound, touch, taste, and smell in the hippocampus region of the brain which, with the frontal cortex, analyzes the input and decides whether they are worth remembering. If they are, they become part of your long-term memory with bits of the information stored in different parts of the brain. How these bits and pieces are later pulled together to form a cohesive memory is still unknown, but scientists believe it is in the synapses and the electrical and chemical signals by which they are connected.
Our Brain is Not a Tape Recorder
Contrary to popular opinion, the brain doesn’t function like a tape recorder or a movie camera collecting every tiny detail of an event which can be replayed in the future. It would physically impossible to store all of the sensory information that bombards us every moment of the day. So the brain stores that small bits of information which is considered most important and reconstructs the rest of the details around those bits when you need it (when you recall the memory). As a consequence, just from a visual viewpoint, you can fail to see things that are there, see things that aren’t there or see something totally different from what is there. The truth, according to neuroscientists and amateur magicians Stephen Macknik and Susana Martinez-Conde, is that your brain constructs what you consider to be reality, visual and otherwise. This is one explanation why two people can experience the same event and have totally different, even opposite recollections of what happened. What you see, hear, feel, and think is based upon what you expect to see, hear, feel, and think. And your expectations are based upon your memories of all you’ve experienced in the past.
Your brain is really a very efficient prediction machine; it takes the bits of data stored from the past (memories) and predicts what will happen next, essentially creating a virtual reality that unusually accurate. For example, even though your eye is roughly equivalent to a one-megapixel camera (less resolution than you probably have on your cell phone), you enjoy a rich, detailed perception of the world. You actually “see” an illusion created by the fill-in processes of your brain.