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| Following on the case of ], in the early 20th century, a medical treatment for insanity involved the severing of the neurons which attached the frontal lobe to the rest of the brain thus rendering it useless. Frontal ] as it is called was later found to have many problems associated, namely that the patients essentially lost all meaning to live. As a result, a less invasive form of frontal lobotomy, known as ], is occasionally used as treatment in modern medicine to ease suffering in terminal patients, or to attempt to remedy psychotic patients who don't respond to drug therapy. | Following on the case of ], in the early 20th century, a medical treatment for insanity involved the severing of the neurons which attached the frontal lobe to the rest of the brain thus rendering it useless. Frontal ] as it is called was later found to have many problems associated, namely that the patients essentially lost all meaning to live. As a result, a less invasive form of frontal lobotomy, known as ], is occasionally used as treatment in modern medicine to ease suffering in terminal patients, or to attempt to remedy psychotic patients who don't respond to drug therapy. | ||
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Revision as of 20:02, 14 February 2004
The frontal lobe is an area in the brains of vertebrates. Located in the front of each cerebral hemisphere, frontal lobes are positioned in front of (anterior to) the parietal lobes. The Temporal Lobes are located beneath and behind the frontal lobes.
Anatomy
In the human brain, the central sulcus separates the frontal lobe from the parietal lobe along the top of each cerebral cortex. The lateral sulcus separates the inferior frontal gyrus of lower frontal lobes from the temporal lobes.
The frontal lobe comprises four major folds of cortical tissue: the precentral gyrus, superior gyrus and the middle gyrus of the frontal gyri, the inferior frontal gyrus.
The precentral gyrus is in front of the central sulcus, and behind the precentral sulcus, which separates it from the frontal gyri. The superior and middle gyri are divided by the superior frontal sulcus. The frontal gyri lie above the inferior frontal gyrus, divided by the inferior frontal sulcus.
The frontal lobes are larger in proportion to other brain areas in many phylogenetically younger vertebrates, when compared to the frontal areas of older species. More of the human brain develops as frontal lobe than in the brains of any other species, comprising the largest individual portion of the human brain.
Function
Frontal lobes assist in planning, coordinating, controlling and executing behavior.
In the human brain, the precentral gyrus and the related cortical tissue that folds into the central sulcus comprise the primary motor area, which controls movements of specific body parts associated with areas of the gyrus, and detects signals from nerves in those same body parts.
Frontal lobes have been found to play a part in impulse control, judgement, language, memory, motor function, problem solving, sexual behavior, socialization and spontaneity.
Cognitive maturity associated with adulthood is marked by related maturation of cerebral fibers in the frontal lobes between late teenager years and early adult years. Research by Dr. Arthur Toga, UCLA, found increased myelin in the frontal lobe gray matter of young adults compared to that of teens, whereas, gray matter in parietal and temporal lobes was more fully matured by teen years. Typical onset of schizophrenia in early adult years correlates with poorly myelinated and thus inefficient connections between cells in the forebrain.
A report from the National Institute of Mental Health says a gene variant that reduces dopamine activity in the prefrontal cortex is related to poorer performance and inefficient functioning of that brain region during working memory tasks, and to slightly increased risk for schizophrenia.
Dopamine-sensitive neurons in the cerbral cortex are found primarily in the frontal lobes. The dopamine system is associated with pleasure, planning and drive. Dopamine tends to limit and select sensory information arriving from the thalamus to the forebrain. Poor regulation of dopamine pathways has been associated with schizophrenia.
Psychological tests that measure frontal lobe function include Finger Tapping, the Token Test and Wisconsin Card Sorting.
Psychosurgery
Following on the case of Phineas Gage, in the early 20th century, a medical treatment for insanity involved the severing of the neurons which attached the frontal lobe to the rest of the brain thus rendering it useless. Frontal Lobotomy as it is called was later found to have many problems associated, namely that the patients essentially lost all meaning to live. As a result, a less invasive form of frontal lobotomy, known as bilateral cingulotomy, is occasionally used as treatment in modern medicine to ease suffering in terminal patients, or to attempt to remedy psychotic patients who don't respond to drug therapy.