[A] What have they found [B] Is it true th

问题：

[A] What have they found
[B] Is it true that laughing can make us healthier
[C] So why do people laugh so much
[D] What makes you laugh
[E] How did you come to research it
[F] So what’s it for
Why are you interested in laughter
It’s a universal phenomenon, and one of the most common things we do. We laugh many times a day, for many different reasons, but rarely think about it, and seldom consciously control it. We know so little about the different kinds and functions of laughter, and my interest really starts there. Why do we do it What can laughter teach us about our positive emotions and social behaviour There’s so much we don’ t know about how the brain contributes to emotion and I think we can get at understanding this by studying laughter.
41. ______
Only 10 or 20 per cent of laughing is a response to humour. Most of the time it’s a message we send to other people--communicating joyful disposition, a willingness to bond and so on. It occupies a special place in social interaction and is a fascinating feature of our biology, with motor, emotional and cognitive components. Scientists study all kinds of emotions and behaviour, but few focus on this most basic ingredient. Laughter gives us a clue that we have powerful systems in our brain which respond to pleasure, happiness and joy. It’s also involved in events such as release of fear.
42. ______
My professional focus has always been on emotional behaviour. I spent many years investigating the neural basis of fear in rats, and came to laughter via that route. When I was working with rats, I noticed that when they were alone,, in an exposed environment, they were scared and quite uncomfortable. Back in a cage with others, they seemed much happier. It looked as if they played with one another--real rough-and-tumble--and I wondered whether they were also laughing. The neurobiologist Jaak Panksepp had shown that juvenile rats make short vocalisations, pitched too high for humans to hear, during rough-and-tumble play. He thinks these are similar to laughter. This made me wonder about the roots of laughter.
43. ______
Everything humans do has a function, and laughing is no exception. Its function is surely communication. We need to build social structures in order to live well in our society and evolution has selected laughter as a useful device for promoting social communication. In other words, it must have a survival advantage for the species.
44. ______
The brain scans are usually done while people are responding to humorous material. You see brainwave activity spread from the sensory processing area of the occi15ital lobe, the bit at the back of the brain that processes visual signals, to the brain’s frontal lobe. It seems that the frontal lobe is involved in recognising things as funny. The left side of the frontal lobe analyses the words and structure of jokes while the right side does the intellectual analyses required to "get" jokes. Finally, activity spreads to the motor areas of the brain controlling the physical task of laughing. We also know about these complex pathways involved in laughter from neurological illness and injury. Sometimes after brain damage, tumours, stroke or brain disorders such as Parkinson’ s disease, people get "stonefaced syndrome" and can’t laugh.
45. ______
I laugh a lot when I watch amateur videos of children, because they’re so natural. I’m sure they’re not forcing anything funny to happen. I don’t particularly laugh hard at jokes, but rather at situations. I also love old comedy movies such as Laurel and Hardy and an extremely ticklish. After starting to study laughter in depth, I began to laugh and smile more in social situations, those involving either closeness or hostility. Laughter re-ally creates a bridge between people, disarms them, and facilitates amicable behaviour.