Industrial societies
in the past 100 years, however, have seen
brain size rebound, as childhood nutrition increased and disease
declined.
When the researchers looked at
brain size, they found that for fighters who had increasing levels of tau over time, there was a 7 percent
decline in the volume of their thalamus, which is located
in the center of the
brain and regulates sleep, consciousness, alertness, cognitive function and language while also sending sensory and movement signals to other portions of the
brain.