推 mulkcs:大推！ 03/16 16:26
推 mulkcs:不過英文報導裡Buckholtz是leader author並非團隊的leader 03/16 16:27
Psychopaths' Brains Wired to Seek Rewards, No Matter the Consequences
ScienceDaily (Mar. 15, 2010) — The brains of psychopaths appear to be wired
to keep seeking a reward at any cost, new research from Vanderbilt University
finds. The research uncovers the role of the brain's reward system in
psychopathy and opens a new area of study for understanding what drives these
individuals.
"This study underscores the importance of neurological research as it relates
to behavior," Dr. Francis S. Collins, director of the National Institutes of
Health, said. "The findings may help us find new ways to intervene before a
personality trait becomes antisocial behavior."
The results were published March 14, 2010, in Nature Neuroscience.
"Psychopaths are often thought of as cold-blooded criminals who take what
they want without thinking about consequences," Joshua Buckholtz, a graduate
student in the Department of Psychology and lead author of the new study,
said. "We found that a hyper-reactive dopamine reward system may be the
foundation for some of the most problematic behaviors associated with
psychopathy, such as violent crime, recidivism and substance abuse."
Previous research on psychopathy has focused on what these individuals lack
-- fear, empathy and interpersonal skills. The new research, however,
examines what they have in abundance -- impulsivity, heightened attraction to
rewards and risk taking. Importantly, it is these latter traits that are most
closely linked with the violent and criminal aspects of psychopathy.
"There has been a long tradition of research on psychopathy that has focused
on the lack of sensitivity to punishment and a lack of fear, but those traits
are not particularly good predictors of violence or criminal behavior," David
Zald, associate professor of psychology and of psychiatry and co-author of
the study, said. "Our data is suggesting that something might be happening on
the other side of things. These individuals appear to have such a strong draw
to reward -- to the carrot -- that it overwhelms the sense of risk or concern
about the stick."
To examine the relationship between dopamine and psychopathy, the researchers
used positron emission tomography, or PET, imaging of the brain to measure
dopamine release, in concert with a functional magnetic imaging, or fMRI,
probe of the brain's reward system.
"The really striking thing is with these two very different techniques we saw
a very similar pattern -- both were heightened in individuals with
psychopathic traits," Zald said.
Study volunteers were given a personality test to determine their level of
psychopathic traits. These traits exist on a spectrum, with violent criminals
falling at the extreme end of the spectrum. However, a normally functioning
person can also have the traits, which include manipulativeness,
egocentricity, aggression and risk taking.
In the first portion of the experiment, the researchers gave the volunteers a
dose of amphetamine, or speed, and then scanned their brains using PET to
view dopamine release in response to the stimulant. Substance abuse has been
shown in the past to be associated with alterations in dopamine responses.
Psychopathy is strongly associated with substance abuse.
"Our hypothesis was that psychopathic traits are also linked to dysfunction
in dopamine reward circuitry," Buckholtz said. "Consistent with what we
thought, we found people with high levels of psychopathic traits had almost
four times the amount of dopamine released in response to amphetamine."
In the second portion of the experiment, the research subjects were told they
would receive a monetary reward for completing a simple task. Their brains
were scanned with fMRI while they were performing the task. The researchers
found in those individuals with elevated psychopathic traits the dopamine
reward area of the brain, the nucleus accumbens, was much more active while
they were anticipating the monetary reward than in the other volunteers.
"It may be that because of these exaggerated dopamine responses, once they
focus on the chance to get a reward, psychopaths are unable to alter their
attention until they get what they're after," Buckholtz said. Added Zald,
"It's not just that they don't appreciate the potential threat, but that the
anticipation or motivation for reward overwhelms those concerns."
The National Institute on Drug Abuse funded the research.
Zald is an investigator in the Vanderbilt Kennedy Center for Research on
Human Development.
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原始網址：
http://www.sciencedaily.com/releases/2010/03/100314150924.htm
Collins做很多和reward有關的研究，這次是做在病患身上。
還蠻有趣的，有人要來翻譯嗎？
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作者: mark89 (Asklepios) 看板: Cognitive
標題: Re: [新知] ScienceDaily-精神病瘓不故一切的追求回報
時間: Tue Mar 16 15:29:18 2010
大腦硬要尋求獎勵 恐致病態心理
http://news.msn.com.tw/news1629305.aspx
更新日期:2010/03/16 06:01
根據今天發布的研究報告，心理病態者的大腦可能硬要尋求獎勵，儘管後果可能危及他人
或自己的性命。研究發現，人體自然分泌的化學物質「多巴胺」，在部分形式的病態暴力
行為與毒癮上，扮演重要角色。
過去的研究把重點放在心理病態者往往缺乏的特質上，好比恐懼、同情和維持正常關係的
能力。然而，田納西州范德堡大學由巴克霍茲（Joshua Buckholtz）率領的研究團隊，深
入檢視的卻是心理病態者有哪些東西是「太過」的，比如衝動以及極度想要尋求冒險和獎
勵。
研究撰寫人之一沙爾狄（David Zald）表示，新數據顯示，心理病態者「對獎勵─也就是
胡蘿蔔─的渴望，已大到掩蓋風險意識或對棍子的顧慮」。關鍵可能在於多巴胺這種神經
介質；多巴胺已知會影響感知和行為，尤其與激勵、懲罰和滿足相關的行為。
古柯鹼、酒精及尼古丁全都刺激大腦的多巴胺腺路。
巴克霍茲說：「我們都認為心理病態者是冷血罪犯，不顧一切後果取得他們想要的東西。
」
「我們發現，過度反應的多巴胺獎勵系統，也許是部分心理病態最有問題行為的基礎，例
如暴力犯罪、累犯和濫用藥物。」
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