Information flows through the brain in two directions: bottom-up and top-down. *Bottom-up information flow* in the brain is from the senses to the higher levels of cognitive processing, and then potentially on to motor control. We see bottom-up processing when we are exposed to sensory experiences and perceive them, and then act on them. *Top-down information flow* in the brain is from the higher cognitive levsl back to the sensory levels. We see top-down processing when we process information based on our prior knowledge, either explicitly or tacitly, and that processing effects what we perceive. Take a guess at what is in this picture: ![[dalmatian.jpg]] Can you see the dalmatian in the picture? Before you read the sentence asking you if you see the dalmatian, you may have been baffled by what is in the picture. When vision is processed strictly with bottom-up processing, it is impossible to understand what is going on. Your brain learns over time how to make distinctions in the visual field, and so uses top-down processing to filter what you are perceiving, just as in the dalmatian picture. You may have been baffled by it at first, but once you knew that you were looking for a dalmatian, or once you identified the dalmatian by yourself, it became easy to see. --- #Psychology/Cognition *June 7, 2021* #2021/6