Can a 40-Hz “rhythm” help the injured brain recover? What gamma entrainment research suggests for TBI. After a traumatic brain injury (TBI) - whether from a fall, sports collision, car crash, or blast exposure - people often describe the aftermath in the same way: brain fog, slowed thinking, memory lapses, fatigue, sleep disruption, irritability.  The injury may be “mild” on a scan, yet life can feel anything but mild. One reason recovery can be so complicated is that TBI doe