The frontal lobes are considered our emotional control centre and home to our personality. There is no other part of the brain where lesions can cause such a wide variety of symptoms. The frontal lobes are involved in motor function, problem solving, spontaneity, memory, language, initiation, judgement, impulse control and social and sexual behaviour.
Personality changes can be apathy, decreased motivation, emotional lability, irritability, anxiety and depression, disinhibition, increased temper flare-ups, aggression, cursing/swearing, lowered frustration tolerance and inappropriate sexual behaviour. Some people after a brain injury become sexually disinhibited; always talking about sex, trying to touch other people in a sexual manner, or wanting to have sex all of the time.
Sexual disinhibition occurs because of the damage to the part of the brain that helps control our behaviour. This usually improves with further recovery, therapy or some may need medication.
A general apathy or disinterest in life and a lack of self-esteem and self-confidence.
An individual may find themselves laughing uncontrollably at something that is only moderately funny, being unable to stop themselves for several minutes. Episodes may also be mood-incongruent; an individual might laugh uncontrollably when angry or frustrated, for example.