[thedoc (OP)]

Is fake laughter different to real laughter?
Asked by Jan Freyberg


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[chapter podcast=1000449 track=13.07.20/Naked_Neuroscience_13.07.20_1001140.mp3]  ...or Listen to the Answer[/chapter] or [download as MP3]

[thedoc (OP)]

We answered this question on the show...

We put this question to Professor Sophie Scott from University College London.
Sophie -   Well, there's two ways you can look at this.  Researchers have done [img float=right]/forum/copies/RTEmagicC_800px-Smiling_girl_04.jpg.jpg[/img]a study looking at people laughing.  So, what happens when you're producing laughter?  And what they did was they asked people to produce the laugh and go, “Hahaha” or they went and tickled them while their feet stuck out the end of the scanner to produce real laughter.  Interestingly, the network in the brain looked very, very similar. You could identify a brain area called the hypothalamus.  It is s a small area that was specifically involved in the real laughter.  So, what you might find is that the real laughter and imposed laughter were very similar maybe in motor terms, but there was an emotional difference and you can see they correlate with that for the real laugh. 
Something that we’re interested in is the flip side of that which is what happens when you hear laughter.  We’ve been looking at what happens when you listen to laughs and unbeknown to you, there's actually two different sorts of laughter in there.  There's real laughter and there's posed laughter.  What we find is, that your brain absolutely tells the difference between the two, whether or not you're told to listen for them.  And actually, you get very interesting observations for the posed laughter because when you hear somebody laughing, and they're clearly not actually helplessly laughing, actually, that's most of the laughter you hear.  When you laugh with your friends, you're not most of the time crying with laughter.  So, it’s an important social cue that tells you people are doing it for some reason.  I think you're always trying to work out why people are laughing.  That's why when you hear posed laughter, there's actually more mystery to it.  Real laughter is unambiguous.  Clearly, some of these are helpless mirth whereas that if you hear somebody going, “Ha, ha, ha!”  “Why are they doing that?  Who are they doing it for?  What's the social buzz?”  Your brain really wants to know more about that.
Hannah -   So, your social part of your brain actually gets more activated when it hears fake laughter than when it actually hears real laughter?
Sophie -   Exactly.  Exactly the same brain areas that you used to work out other people’s motivations and thoughts are activated more and you hear people laughing in a posed way.  For the real laughter, you get lots of more auditory activation.  That probably reflects the fact that real laughter, if you think back to the last time you were laughing and you could not stop laughing, you're actually producing incredibly strong pressure in your rib cage since you're forcing the air out in those laughs.  It produces a set of sounds that you don’t produce any other way, and you couldn’t any other way.  So, acoustically, real laughter has some very interesting hallmarks that I think are we get more auditory activation to it.

[LaurenaS]

In terms of the difference, yes they are. You may probably notice most fake laughter already by hearing the sound of it, like certain acoustic features. Fake laughter sound more like a speech