Researchers have shed light on the chemistry that bonds one person to another by taking brain scans of men being stroked while in their underpants.
据英国《卫报》报道，研究者在对大脑进行扫描时发现，当男性穿着内裤被女性抚摸时，大脑皮层会分泌一种化学物质，增强双方关系。
The Finnish study found that gentle stroking – which was not in sexually arousing areas – changed levels of opioid brain chemicals which work behind the scenes to form lasting bonds in animals.
芬兰科学家研究发现普通程度的抚摸——不触及性敏感地带——将会改变大脑内阿片类化学物质（ opioid brain chemicals）的分泌程度，这些分泌物会在动物体内起到促成长久联系的作用。
The findings suggest that opioids might be the critical chemicals that enables human brains to distinguish between strangers and people who are closer to us, such as friends, families and lovers.
研究表明，阿片类物质可能作为一种非常重要的化学物质，帮助人类大脑区别陌生人以及关系亲密的人，诸如朋友、家人和恋人。
"We know this is hugely important for humans because we have these strong, lasting bondings with friends and relatives and so on. But what kind of system maintains these bonds, and makes them last?" said Lauri Nummenmaa who studies the neural circuitry of emotions at Aalto University in Finland.
芬兰阿尔托大学(Aalto University)情绪神经回路研究员,劳瑞·努曼玛（Lauri Nummenmaa）表示：“这个发现对于人类而言相当重要，因为我们与我们的朋友，亲属等都有着深刻，持久的关系。但究竟是什么样的生理系统在维持这种联系，使得这种关系得以长久保持的呢？”
Studies in animals have shown that opioids can play a crucial role in pairing up. Prairie voles are monogamous in the wild, but when given a drug that blocks opioid in their brains, they seek out other partners. If opioids are blocked in monkeys, they groom others less and neglect their babies.
动物实验中发现，阿片类物质将在两性关系中起到至关重要的作用。野生的草原田鼠属于单配型生物，但当实验组给草原田鼠服用药物，脑中阿片类物质分泌被抑制以后，它们开始寻找其他的伴侣。倘若猴子脑内的阿片类物质被抑制分泌，它们梳理其他同类毛发的次数减少，也不再看护自己的小孩。
To see whether opioids were important in human bonding, the researchers invited nine couples into the lab. The men stripped off to their underpants and lay under a blanket in a PET scanner. The first scan was taken while the men were alone. For the second, their partners touched them gently all over, but avoided anywhere likely to arouse them sexually.
为了研究阿片类物质对于人类关系是否具有重要的作用，研究人员邀请了九对伴侣参加实验。所有男性要求脱去衣物，只保留内衣，然后让他们平躺在正子扫描仪下，盖上毛毯。在他们处于单人环境下时，进行第一次扫描。接着邀请他们的伴侣轻柔的抚摸其全身，但尽量避免触碰他们的性兴奋区，然后对所有男性进行第二次扫描。
"I'm really proud of the Finnish general public," said Nummenmaa. "We had no problem whatsoever in recruiting people for the experiment."
努曼玛表示:“我为芬兰大众感到非常骄傲。”“我们不费力气就找到了愿意参与本次实验的志愿者。”
When the researchers compared the men's scans, they noticed that gentle stroking caused a drop in natural opioids in brain areas called the ventral striatum and the anterior cingulate cortex, which are mainstays of the brain's reward circuitry. This was counter to expectations: they had expected levels to rise.
当研究人员对比两次扫描结果后发现，轻柔的抚摸导致大脑内部腹侧纹状体与前扣带脑皮质分泌自然阿片类物质，而二者正是大脑奖励回路机制的重要区域。但这一发现与之前的预测相违背：研究人员本期待阿片类物质在分泌浓度上有所提升。
Nummenmaa said that opioid might work in a similar way to a painkiller, with the body needing less the more comfortable it was. "The opioid system is typically engaged during pain, so you get a boost in painful situations. The social touching might be doing exactly the opposite. You can think of it as pain alleviation. That might be the underlying mechanism for why hooking up with others makes us feel so good in the first place," said Nummenmaa. Details of the study were given at theSociety for Neuroscience meeting in San Diego.
努曼玛声称，阿片类物质也许在某种程度上与止疼片起着类似的作用，当身体需求减少时，人就会感到更加舒服。努曼玛称：“阿片类系统传统上会在出现疼痛时被分泌出来。所以当你感到疼痛时，它就会被大量分泌出来。而社交性的触碰或许与之完全相反，你可以把它当成缓解疼痛的物质。它或许可以被看成一种基本机制，用于解释为什么当去勾引别人的时候会首先让我们感觉如此棒。”圣地亚哥举行的神经科学学会会议（Society for Neuroscience meeting）上给出了关于此次实验的详细信息。
Opiate drugs have the same effect as the body's natural opioids, and just as people build up tolerances to drugs, develop cravings, and suffer withdrawal symptoms, similar processes play out with relationships.
阿片类药物与人体分泌的自然阿片类物质有着相同的效果，就像人体对药物产生的耐药性曲线一样，会遭遇脱稳状态（withdrawal symptoms）,人类的关系也会经历相同的过程。
"If something similar happens when you are establishing social bonds that would make perfect sense. You would need your daily fix, or at least a fix now and then, and unless you got that you would start to feel pain," said Nummenmaa.
努曼玛表示，"如果你与别人建立某种联系,在你感觉相当好的时候出了点事,除非你不再感到痛苦，否则你就需要来一个日常调整，或者至少时不时需要调整一下你自己。"