Sensory Integration/Sensory Processing
Sensory Integration is a theory and frame of reference that describes a process in the brain, and framework for evaluation and intervention. 
It is based on the main principles of brain function, including: neuroplasticity, development, integration, and feedback. This model of theory was developed in the 1960s by Jean Ayres, a researcher, educator, and occupational therapist. She used her research to identify the sensory and motor constructs for occupation.
Sensory processing refers to the ability to take information from our senses (touch, movement, smell, taste, vision, and hearing) and puts it together with prior information, memories, and knowledge stored in the brain to make a meaningful response. These sensory systems are the building blocks to learning. They include:
Vestibular System (movement sense) – This is the sensory system that responds to changes in head position, body movement through space, and regulates our balance system.
Proprioception System (position sense) – This is the sensory system that interprets the information you receive from your muscles. It tells us where our body parts are and where our body is in space.
Tactile System (touch sense) – This is our sense of touch we receive through our skin. It helps one to learn about their body and the environment they live in. We distinguish touch by two different kinds: light (gives the body an alerting message) and deep (gives the body comfort) touch.
Sensory processing difficulties may impact a child’s ability to participate in their daily occupations. Differences in processing sensory input may impact a child’s development of fine, visual , and gross motor skills. It may also impact social participation, motor planning, participation in self-care, academic success, and feeding.
Sensory based therapy helps to improve the processing of input within the individual, so that they can be active participants in their daily occupations, or activities.