How a child with disabilities and disorders processes information is dependent upon the disability. You're mainly looking at three areas of of processing: receiving the information, processing the information, expressing the information. Children can have disabilities relating to receiving information. These can can be hearing disabilities and interpretation disabilities. The child may approach the presentation of information in an inaccurate way. Then there are children with actual comprehension, processing diabilities. These diasabilities allow the child to take in the information but then not be able to assimilate it into prior learning, or the child may misplace the information in their mind. Finally, a child with a disability may have difficulty expressing what they know. They may have received and processed the information correctly but cannot express that they have that learning. This disabilty of expressive language can mask true learning that is taking place. I've added a link to a book that has excellent information about teaching students with disabilities.