Tag Archives: live science

Laughter experiment at the Science Museum. Credit: Science Museum.

What makes you laugh and cry?

Professor Sophie Scott explains her latest experiment at the museum, exploring the science behind laughter. 

Last year, we had a mouse somewhere in our flat, and we were all stressing out about it a bit. I was at home on my own when I thought I felt something running over my foot. It was a hair pin falling out of my hair, but before I had realized this, I screamed out loud. I screamed loud enough and long enough for me to have time to think things like “Why am I screaming?”, “I am not afraid of mice” and “Pretty sure that was a hairpin”.

The really interesting part of the mouse incident was that my scream was involuntary – I really did not mean to do this (there’s a great example here). Involuntary vocalizations are produced via a neural system we share with other mammals, but a separate network in the brain controls speech. This speech network, which evolved much later, allows us to produce the complex movements which underlie speech and song and to do so voluntarily – we choose when to speak.

A spectrogram of the sentence “the house had nine rooms”. The horizontal axis is time, the vertical axis is frequency.  This shows the acoustic complexity of speech.

A spectrogram of the sentence “the house had nine rooms”. The horizontal axis is time, the vertical axis is frequency. This shows the acoustic complexity of speech. Credit: Sophie Scott

The older, involuntary system is associated with emotional vocalizations in humans – like my screaming or a cry of surprise. These emotional sounds (such as crying, screaming, laughing) are more like animal calls than they are like speech.

This shows laughter. Note how much less complex the sound is. Credit: Sophie Scott.

This shows laughter. The sound is much less complex than speech. Credit: Sophie Scott.

This shows a spectrogram of a cat meowing. As with the laughter, we can see  spectral structure but this does not vary much over time. Credit: Sophie Scott.

This shows a spectrogram of a cat meowing. As with the laughter, we can see spectral structure but this does not vary much over time. Credit: Sophie Scott.

Our more recent voluntary system is associated with speech and song (and other vocal skills such as beatboxing). If this system is damaged, for example, due to a stroke, people can be left with aphasia – a persistent problem with talking. They very often can still make emotional noises, such as laughing, suggesting that the stroke has not damaged this older pathway.

For my research, we are studying what it means to make voluntary and involuntary vocalizations – for example, laughter is used a great deal during conversational speech. Even babies use emotional expressions like crying and laughter in extremely sophisticated ways.

This all suggests that there may be both voluntary and involuntary kinds of emotional sounds. Are laughs and sobs produced in a voluntary or an involuntary fashion really different? How do they sound to us? How does this change as we age?

Laughter experiment at the Science Museum. Credit: Science Museum.

Laughter experiment at the Science Museum. Credit: Science Museum.

To help discover the answers to these questions, we are running an experiment at the Science Museum. We ask people to listen to ‘real’ and ‘posed’ laughter and sobbing sounds to find out how they sound to people. So if you are interested in knowing anything more about voices and emotion do please come along and take part in our research – we promise not to make you scream.

Listen to Your Heart

Dr. Corrinne Burns, Assistant Content Developer in the Contemporary Science team, writes about Listen to your Heart, a Live Science experiment where visitors explore interoception.

How good are you at figuring out what people are thinking? Can you put yourself in someone else’s shoes? Alternatively, are you cool and collected? Can you regulate your emotional responses?

Surprisingly, researchers think that all these qualities could be related to something called interoception – that is, how good you are at sensing the workings of your inner body, like your heartbeat.

We are very familiar with what scientists call exteroceptive signals – sight, sound, smell and other sensory inputs which comes from outside the body. But until I met Dr Manos Tsakiris and his team, I had no idea that we also experience internal sensory input, produced from within our bodies by our ongoing physiological processes. These interoceptive signals create a kind of constant background sensory noise, and some of us are more aware of that noise than others.

Sections of the heart. Engraving made in Paris, 1864.

Sections of the heart. Engraving made in Paris, 1864. Credit: Florilegius / Science & Society Picture Library

Manos wants to know whether there’s a link between how good our interoceptive awareness is, and how well we engage with other people and our environment. We thought this sounded absolutely fascinating, and so we invited Manos and his research team to do some real live experiments right here in the Museum. Now we need you to come down and take part!

So what happens in the experiment? You’ll place your wrist on a sensor, which will count your heartbeats. Now, without looking at the sensor readout – that would be cheating! – you will be asked to really concentrate, and try to count your own heartbeats.

So this bit of the experiment will tell the guys how good your interoceptive awareness is. The next bit of the experiment will test how good you are at interpreting other people’s feelings, or seeing the world from someone else’s perspective. Or maybe how good you are at regulating your emotions, or whether you prefer to rely on your body or your vision to navigate your way around.

The whole thing will only take ten minutes or so, and you’d be contributing to some seriously cool research. This data could, ultimately, help us to understand how interoception creates our sense of self – that sense that there is a “me” residing within our body.

Manos and the team will be our Who Am I? gallery – every Monday, Wednesday and Saturday until 13th July for Listen to your Heart.