It means go to bed. Mattresses were once stuffed with hay or straw, so the image is ofyou flopping down on your mattress and hitting the hay.
Causes. There is no known single cause for autism spectrum disorder, but it is generally accepted that it is caused by abnormalities in brain structure or function. Brain scans show differences in the shape and structure of the brain in children with autism compared to in neurotypical children.auses. There is no known single cause for autism spectrum disorder, but it is generally accepted that it is caused by abnormalities in brain structure or function. Brain scans show differences in the shape and structure of the brain in children with autism compared to in neurotypical children.
Autism forms the core of the autism spectrum disorders. Asperger syndrome is closest to autism in signs and likely causes; unlike autism, people with Asperger syndrome usually have no significant delay in language development, according to the older DSM-4 criteria. PDD-NOS is diagnosed when the criteria are not met for a more specific disorder.