Español Português
"BRAVE NEW BRAIN", Conquering Mental Illness in the Era of the Genome, Nancy C. Andreasen, 2000, pages 68 - 69
Is The Prefrontal Cortex Our Moral Monitor?
The Prefrontal System, or prefrontal cortex, is one of the largest critical subregions in the human brain. Brodmann estimated that it constitutes 29% of the cortex in human beings, as compared to 17% chimpanzees, 7% in dogs, and 3.5% in cats.
Its high degree of development in human beings suggests that it too may mediate a variaty of specifically human functions, often referred to as "executive functions" such as abstract thought, creative problem solving, and temporal sequencing of behavior.
The lesion method provided an early landmark in our understanding of the prefrontal cortex through the case of Phineas Gage, a quarry worker who was injured by explosion that drove an iron bar through his left frontal lobe. Gage survived the bizarre accident, but afterward he began to show serious personality changes that were described by Harlow (the physician who cared for him and saved his life).
Prior to the accident Gage was conscientious, serious, and hardworking, but after recovered he became immature, child-like, socially inappropiate, and irresponsible. Harlow's early descriptions of frontal lobe functions has been supplemented by many subsequent studies of people with frontal tumors, injuries to the frontal lobe, and surgical treatment for epilepsy, psychosis or obsessive-compulsive disorder. This work indicates that substantial damage to the prefrontal cortex produces a syndrome quite similar to that of Gage.
Although general intelligence is not necessarily impaired by frontal lesions, individuals with substantial frontal injury the other capacities such as volitions, the ability to plan, and social judgment.
Two different subtypes of "frontal syndromes" have been observed:
Lesions to the orbital region of the prefrontal cortex (a more "primitive" part of the frontal cortex on its lower surface, just above the eyes) make people euphoric, overactive, and inclined to inappropriate social behavior such as sexual overtures to unknown people.
Lesions to the dorsolateral portion (the outer convexities of the frontal lobes on the side of the brain) make people apathetic, physically inactive, and less able to perform complex cognitive tasks such as formulating an abstract concept.
Within both of these syndromes, however, lies a common core: impairment in the capacity to pursue goal-directed behavior, based in the integration of environmental and internal cues. This is probably the basic functions of the prefrontal cortex.
The prefrontal cortex matures particularly late in human beings, concluding its development in the third decade of an individual’s development. (which partly explains the behavior of "typically adolescent" angry, insecure and confused).
Its high degree of development in human beings suggests that it too may mediate a variaty of specifically human functions, often referred to as "executive functions" such as abstract thought, creative problem solving, and temporal sequencing of behavior.
The lesion method provided an early landmark in our understanding of the prefrontal cortex through the case of Phineas Gage, a quarry worker who was injured by explosion that drove an iron bar through his left frontal lobe. Gage survived the bizarre accident, but afterward he began to show serious personality changes that were described by Harlow (the physician who cared for him and saved his life).
Prior to the accident Gage was conscientious, serious, and hardworking, but after recovered he became immature, child-like, socially inappropiate, and irresponsible. Harlow's early descriptions of frontal lobe functions has been supplemented by many subsequent studies of people with frontal tumors, injuries to the frontal lobe, and surgical treatment for epilepsy, psychosis or obsessive-compulsive disorder. This work indicates that substantial damage to the prefrontal cortex produces a syndrome quite similar to that of Gage.
Although general intelligence is not necessarily impaired by frontal lesions, individuals with substantial frontal injury the other capacities such as volitions, the ability to plan, and social judgment.
Two different subtypes of "frontal syndromes" have been observed:
Lesions to the orbital region of the prefrontal cortex (a more "primitive" part of the frontal cortex on its lower surface, just above the eyes) make people euphoric, overactive, and inclined to inappropriate social behavior such as sexual overtures to unknown people.
Lesions to the dorsolateral portion (the outer convexities of the frontal lobes on the side of the brain) make people apathetic, physically inactive, and less able to perform complex cognitive tasks such as formulating an abstract concept.
Within both of these syndromes, however, lies a common core: impairment in the capacity to pursue goal-directed behavior, based in the integration of environmental and internal cues. This is probably the basic functions of the prefrontal cortex.
The prefrontal cortex matures particularly late in human beings, concluding its development in the third decade of an individual’s development. (which partly explains the behavior of "typically adolescent" angry, insecure and confused).
"BRAVE NEW BRAIN", Conquering Mental Illness in the Era of the Genome, Nancy C. Andreasen, 2000, pages 68 - 69
No comments:
Post a Comment