David Amaral of the MIND Institute at UC-Davis says ideally, treatment should begin before autism has a chance to cause permanent changes in children's brains.

NPR: Researchers Set Sights on Early Autism Diagnosis

This does not involve permanent changes to the brain's structure.

ECONOMIST: Memory and emotion: Thanks for no memory | The

Moreover, the studies do not distinguish between permanent changes in a rich person's taxable income and temporary effects that are due to timing alone.

ECONOMIST: How much do high-income people respond to tax changes?