In fact, muscle fibres may be more developed than those of a person without the disorder.
In the other study, researchers from the National Institute of Mental Health and McGill University, using imaging techniques, found that the brains of children with attention-deficit hyperactivity disorder developed normally but more slowly in some areas than the brains of children without the disorder.
But while this variant occurs in a vast majority of people with narcolepsy, it also is carried by many others without the disorder.
In the largest study ever into the genetics of autism, the scientists identified rare genetic variations that were 20% more frequent in children with autism than in children without the disorder.
Researchers at the Mayo Clinic reviewed the medical records of more than 100 autistic children over 18 years and compared them with more than 200 children without the disorder.
It's long been known that medications designed to boost focus and impulse control in children with attention deficit hyperactivity disorder offer the same benefits to people without the disorder.
The next test will be to discover whether people with schizophrenia can also hear, smell, touch and taste things more accurately, but with less attention to context, than those without the disorder.
While these medicines tend to calm people with A.D.H.D., those without the disorder find that just one pill can jolt them with the energy and focus to push through all-night homework binges and stay awake during exams afterward.
Using an imaging device known as a spectroscope, researchers at the University of Washington examined the children before they took part in the study and found that the dyslexic children used four times as much brain energy to process sounds as did children without the disorder.
For instance, Hayden learned of a family with an inherited inability to feel pain, and was able to identify the faulty protein responsible; his lab recently published the results of a preliminary trial of a drug that targets the same protein in people without the disorder, and that may represent an entirely new class of painkillers).
