The first stage of perception is selection or directing attention to a subset of the stimuli available to the senses. In your efforts to read these words, you selectively attend to the marks on the page, and you screen out or ignore the feel of the chair against your body, the noises around you, and thoughts about other tasks you have to do. Selection can be guided through conscious control; for example, you might direct your attention to the conversation at the next table in an effort to eavesdrop. More often, however, the selection of stimuli for further processing happens subconsciously. In other words, our brains

Make a list of things that you notice around you at this moment. Then, concentrate on each of your senses – what you see, hear, smell, and feel – one at a time, and make a list of anything new that you perceive. How do the two lists compare?