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It has been known for decades, on the basis of stroke and brain lesion studies, that the prefrontal cortex plays a major role in the regulation of behavior, and particularly the inhibition of certain behaviors, such as aggression. The earliest and most famous illustration of this is the case of Phineas Gage, who in 1848 had a tamping iron shot through his skull and prefrontal cortex. Though he survived the injury, he afterwards exhibited impulsive and antisocial behavior. Since that time, there have been numerous other instances reported in the neurological literature where damage to the same brain areas are followed by radical changes in behavior, particularly a marked lack of inhibition of sexual or aggressive impulses.
One of the more interesting cases I've read about is that reported by Blair and Cipolotti (2000). Their subject, J.S., was a 56 year-old electrical engineer, who, prior to the cerebral infarction which partially destroyed his prefrontal cortices, had no psychiatric history and according to a relative was quiet and withdrawn. After the prefrontal trauma, J.S.'s behavior was "gravely disturbed," and included physical attacks on others. According to Blair and Cipolotti (2000): Quote:
Standard tests at the hospital revealed neuropsycological deficits, and an MRI was done. This revealed a very large right prefrontal tumor. Following resection of the tumor, the symptoms disappeared completely. However, 7 months later, the subject began experiencing both the headaches and sexual impulse control problems once again. MRI revealed regrowth of the tumor, and after a second resection of the tumor, the behavioral problems again disappeared! See Putting The Brain On Trial Refs and further reading: Anderson et al, 1999. Impairment of social and moral behavior related to early damage in human prefrontal cortex. Nature Neuroscience 2, 1032 - 1037. Best et al, 2002. Evidence for a dysfunctional prefrontal circuit in patients with an impulsive aggressive disorder. Proc. Natl. Acad. Sci. U. S. A. 99: 8448-8453 Blair and Cipolotti, 2000. Impaired social response reversal A case of `acquired sociopathy.' Brain, Vol. 123, No. 6, 1122-1141.. Burns and Swerdlow, 2003. Right Orbitofrontal Tumor With Pedophilia Symptom and Constructional Apraxia Sign. Arch Neurol. 2003;60:437-440. Cai et al, 2002. Serotonin 5-HT1A Receptors Regulate AMPA Receptor Channels through Inhibiting Ca2+/Calmodulin-dependent Kinase II in Prefrontal Cortical Pyramidal Neurons. J. Biol. Chem. 277: 36553-36562 Damasio et al, 1990. Individuals with sociopathic behavior caused by frontal damage fail to respond autonomically to social stimuli. Behav Brain Res 41: 81�94. Davidson et al, 2000. Dysfunction in the Neural Circuitry of Emotion Regulation--A Possible Prelude to Violence. Science 289, pp. 591-594. Kim et al, 2002. Inability to control anger or aggression after stroke. Neurology 58: 1106-1108 New et al, 2002. Blunted Prefrontal Cortical 18Fluorodeoxyglucose Positron Emission Tomography Response to Meta-Chlorophenylpiperazine in Impulsive Aggression. Arch Gen Psychiatry 59: 621-629 Shamay-Tsoory et al, 2003. Characterization of Empathy Deficits following Prefrontal Brain Damage: The Role of the Right Ventromedial Prefrontal Cortex. Journal of Cognitive Neuroscience 15:324-337. Patrick |
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#2 |
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Am I mistaken or would the assertion that, the prefrontal cortex acts in more of a reactive manner in response to an emtional impulse, be consistent with the concept of social behavior as an evolutionary development?
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#3 |
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So, wait...
damage to a physcial part of the brain causes people to engage uncontrollably in acts commonly considered to be "sins"? Hmmmm... (I just make the connections, I don't interpret them. ![]() |
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#4 | |
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Semendeferi et al, 2001. Prefrontal cortex in humans and apes: a comparative study of area 10. Am J Phys Anthropol 114(3):224-41. Stuss and Levine, 2002. Adult clinical neuropsychology: lessons from studies of the frontal lobes. Annu Rev Psychol 53:401-33. Stone et al, 1998. Frontal lobe contributions to theory of mind. J Cogn Neurosci 10(5):640-56. Patrick |
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#5 |
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Thank you ps418 for providing such an interesting thread. I wonder what the defenders of a non-compatibilist version of "free will" have to say about such things...
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