Organic Mental Disorders
After being struck on the head by a four-by-four piece of wood, a previously serious and dependable construction worker starts making inappropriate sexual remarks to his coworkers, is easily distracted, and loses his temper over minor provocations. What part of his brain has most likely been damaged?
a. The frontal lobes are associated with the regulation of emotions, the manifestation of behavioral traits usually connected to the personality of an individual, and executive functions (the ability to make appropriate judgments and decisions and to form concepts).
b. They also contain the inhibitory systems for behaviors such as bladder and bowel release.
c. Damage of the frontal lobes causes impairment of these functions but it is not, strictly speaking, a form of dementia, because memory, language, calculation ability, praxis, and IQ are often preserved.
d. Personality changes, disinhibited behavior, and poor judgment are usually seen with lesions of the dorsolateral regions of the frontal lobes.
e. Lesions of the mesial region, which is involved in the regulation of the initiation of movements and emotional responses, cause slowing of motor functions, speech, and emotional reactions.
f. In the most severe cases, patients are mute and akinetic.
g. Lesions of the orbitofrontal area are accompanied by abnormal social behaviors, an excessively good opinion of oneself, jocularity, sexual disinhibition, and lack of concern for others.