Daydreaming in a class and not hearing what the teacher is saying until your name is called is an example of selective attention. selective exposure. perceptual acceptuation. halo effect.

Selective attention - This is the process by which our mind is capable of focusing on certain specific stimuli even in the presence of many other stimuli at the same time. This way, our mind can tune out things that we find unimportant so that we can concentrate on those things that we find important. Although it can get us into trouble in class most of the time, it is actually a blessing for us. Imagine what would have happened if your mind had to process each and every sound and stimulus around you, including a barking dog, the whirring of a machine, a bird cooing outside ... would have given you a bad headache all the time!