The soft tissue sloshing around our skulls dictates more than intellectual capacity, brain experts say.

Amrik Singh, who killed himself and his wife in a fire at their Sterling Heights home on Sunday, believed that a Head injury led to his depression and suicidal thoughts.
Doctors realized how much the brain shapes personality in 1848, when railroad foreman Phineas Gage became a medical curiosity.

An accidental explosion on the work site rocketed a 3-foot-long rod through Gage’s brain. Amazingly, he wasn’t killed - but the mild-mannered man took on new personality traits, becoming crass and combative.

Michael Dabbs, president of the Brain Injury Association of Michigan, said some brain injuries can be acute.

“If you were to shoot a bullet through your hand, the damage is going to be relatively confined,” he said. But with head injuries caused by specific trauma - car accidents, for example - the brain bounces around the skull. It bruises. Sometimes, it bleeds.

Dabbs said doctors regularly disagree on the extent of personality changes and neurological damage.

“This is all new science, believe it or not,” he said.

Traumatic brain injuries weren’t recognized by the federal government until 1996, he said. That’s when then-President Bill Clinton signed a law expanding the research of such injuries.

“It’s been only since 1996 that statistical evidence has started to be gathered,” Dabbs said. “You’d think we’d know more about this stuff than we do, but we don’t.”

Some high-profile cases have helped shed light on the condition. Dabbs said the 1981 shooting of Jim Brady, then-President Ronald Reagan’s press secretary, was the “start of the brain injury movement as we know it.” Brady was shot in the head in an assassination attempt.

Other cases include that of Red Wings player Vladimir Konstantinov, whose limo wrecked in 1997. After the hockey player awoke from a coma, he had to relearn basic skills and was no longer able to play alongside his teammates.

Also, family members of actor Spalding Gray said severe head injuries he sustained in a 2001 car crash sent him spiraling into a deep depression, leading to his suicide earlier this year.