Hind brainHind brainMid brain
Mid brainMid brainMid brainFore brainFore brain
Spinal cordSpinal cordTypical child
Cerebral hemisphereCerebral hemisphereCerebellumCerebellumPonsPonsMedullaMedulla25 days25 days35 days35 days40 days40 days50 days50 days100 days100 days9 months9 months5 months5 monthsAutistic childFigure 1.12 Development of a typical human and an autistic human fetal brain from
25 days to 5 months of gestation. In the majority of autism cases, the problems arise during
the very early stages of the fetal brain development. A few progenitor neurons, destined to
mature into a specialized faculty are killed or mutated, resulting in ASD. An autistic child’s
brain is larger but has parts missing (see text for details).