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发布时间:2020-06-11 作者:admin 点击:83

Unexpected uncertainty can breed paranoia


上海译锐翻译    2020-6-11   16:01


In times of unexpected uncertainty, such as the sudden appearance of a global pandemic, people may be more prone to paranoia, Yale University researchers suggest in a new study published in the journal eLife.


"When our world changes unexpectedly, we want to blame that volatility on somebody, to make sense of it, and perhaps neutralize it,'' said Yale's Philip Corlett, associate professor of psychiatry and senior author of the study. "Historically in times of upheaval, such as the great fire of ancient Rome in 64 C.E. or the 9/11 terrorist attacks, paranoia and conspiratorial thinking increased."

“当我们的世界发生一些意想不到的变化时,我们希望将这一剧变怪罪在某个人头上,想把这些变化弄清楚,或也许希望能够淡化它”,耶鲁大学精神病学助教兼研究资深作者Philip Corlett表示。“历史上所出现的动荡剧变,比如公元后64年古罗马的大火或9/11恐怖袭击,都会造成妄想症和阴谋思维增加。”

Paranoia is a key symptom of serious mental illness, marked by the belief that other people have malicious intentions. But it also manifests in varying degrees in the general population. For instance, one previous survey found that 20% of the population believed people were against them at some time during the past year; 8% believed that others were actively out to harm them.


The prevailing theory is that paranoia stems from an inability to accurately assess social threats. But Corlett and lead author Erin Reed of Yale hypothesized that paranoia is instead rooted in a more basic learning mechanism that is triggered by uncertainty, even in the absence of social threat.

比较普遍的一个理论是妄想症起源于无法正确评估社会威胁。但是,耶鲁大学的Corlett和首席作者Erin Reed则假设,妄想症其实根源于某个更加基础性的认知机制,这一认知机制由不确定性所触发,即使是在没有社会威胁的情况下。

"We think of the brain as a prediction machine; unexpected change, whether social or not, may constitute a type of threat -- it limits the brain's ability to make predictions," Reed said. "Paranoia may be a response to uncertainty in general, and social interactions can be particularly complex and difficult to predict."


In a series of experiments, they asked subjects with different degrees of paranoia to play a card game in which the best choices for success were changed secretly. People with little or no paranoia were slow to assume that the best choice had changed. However, those with paranoia expected even more volatility in the game. They changed their choices capriciously -- even after a win. The researchers then increased the levels of uncertainty by changing the chances of winning halfway through the game without telling the participants. This sudden change made even the low-paranoia participants behave like those with paranoia, learning less from the consequences of their choices.


In a related experiment, Yale collaborators Jane Taylor and Stephanie Groman trained rats, a relatively asocial species, to complete a similar task where best choices of success changed. Rats who were administered methamphetamine -- known to induce paranoia in humans -- behaved just like paranoid humans. They, too, anticipated high volatility and relied more on their expectations than learning from the task.

在一个相关的实验中,耶鲁大学合作伙伴Jane Taylor和Stephanie Groman对老鼠,一个相对不合群的物种进行了训练。在实验中,老鼠需要完成类似的任务,但是在要完成的任务中,最佳的选择发生了变化。被注射甲基苯丙胺(一种可以导致人类出现妄想症的成分)的老鼠的表现和有妄想症的人群完全一样。它们同样倾向于认为事物反复无常并且更多的依赖于自己的期待而非从任务中学到的经验。

Reed, Corlett and their team then used a mathematical model to compare choices made by rats and humans while performing these similar tasks. The results from the rats that received methamphetamine resembled those of humans with paranoia, researchers found.


"Our hope is that this work will facilitate a mechanistic explanation of paranoia, a first step in the development of new treatments that target those underlying mechanisms," Corlett said.


"The benefit of seeing paranoia through a non-social lens is that we can study these mechanisms in simpler systems, without needing to recapitulate the richness of human social interaction," Reed said.


文章来源:科学日报    编辑:质控部