Sensory processing disorder is when a person’s brain doesn’t process information in an efficient, organized manner.
The information that comes through the senses is supposed to be processed by the brain, and then in return inform the person as to what is going on around him or inside him.
A person who has sensory processing disorder may be processing information in a jumbled fashion, or may be getting too much information at once to effectively process, or he may be not getting enough input from his senses.
A child who is not getting enough sensory input will commonly seek it with behaviors that seem inappropriate or compulsive. A child who is sensitive to sensory input and has too much to process will typically avoid sensory stimulating activities.
Many children are combined “seekers”/”avoiders” for different senses.