What happens to the human brain during a traumatic event? When a person experiences trauma, whether that be acute, chronic, or complex, the chemistry inside the brain is altered and the brain begins to function differently. This is a protective mechanism that we all have that quickly kicks in when we are threatened or in harm’s way—this is our brain’s way of insulating and protecting itself. Understanding this brain shift helps victims who have been affected by trauma better understand their experiences and the emotional aftermath of those events.