image Scientific American, February 2000
image scanned by Patricia Clark

AUTISM'S EFFECTS include changes to the brain stem, the region just above the spinal cord.
The brain stem of a person with autism is shorter than a normal brain stem; the structures at the
junction of the pons and the medulla(such as the facial nucleus and the trapezoid body) are closer
to the structures of the lower medulla(the hypoglossal and the inferior olive).
It is as though a band of tissue were missing. The brain stem of a person with autism also lacks the
superior olive and has a smaller-than-normal facial nucleus.
Such changes could occur only in early gestation.