DISINHIBITION  [ back to Glossary Index ]
Disinhibition refers to anti-social behavior in which frontal lobe control over impulses is missing. A person with disinhibition from a TBI will engage in a variety of behaviors tending to alienate others, including talking or laughing way too loud, making crude sexual remarks or engaging in appropriate grabbing of other people's sexual parts, becoming angry, threatening and even violent over objectively minor provocation, grabbing food off other people's plates and eating it, etc. The brain malfunction responsible for disinhibition has been located in the brain area behind the eyes, called the orbito-frontal region, especially the ventro-medial portion of the pre-frontal lobes. Research on childhood development shows the wiring of the orbito-frontal brain area is largely complete by age 18 months, and that the quality of the wiring is heavily influenced by how the parent or caretaker treats the child. Warmth, nurturing and affectionate holding, touching and cooing make the toddler feel safe and loved and promote the health of that brain area. Screaming, hitting and shaking the toddler do just the opposite. Neuro-imaging studies on death row inmates and the most violent prison inmates show they all have defective connections in their orbito-frontal region. This is associated with childhood abuse and neglect as well as traumatic brain damage occurring in early adulthood when such persons get in fights and suffer violent head contact. Bad wiring the orbito-frontal region is associated with imbalances in mood chemicals, which make a person sense threat and hostility all around him, even when there is none. In the most dramatic cases, orbito-frontal damage creates a person with something akin to Road Rage. Since orbito-frontal damage occurs on a wide spectrum from very mild to very severe, so does the level of disinhibition. For a professional person in a competitive business environment where perfect self-control is required for success, even mild disinhibition can lower earning capacity and income, and lead to social exclusion.