From the article: > A second study [23] found that high exposure to lead during childhood was linked to a permanent loss of gray matter in the prefrontal corte

From the article: > A second study [23] found that high exposure to lead during childhood was linked to a permanent loss of gray matter in the prefrontal cortex—a part of the brain associated with aggression control as well as what psychologists call "executive functions": emotional regulation, impulse control, attention, verbal reasoning, and mental flexibility.