Biology of emotions

It’s late in the evening and Lina is walking home. She was very surprised when Michael asked her to take a long walk in the park, and then watch a film. But the date was really nice, and she’s very happy she went. All of a sudden, Lina hears footsteps behind her, and she starts feeling afraid. But what does it really mean — to be surprised, happy, afraid?

We use the words surprise, happiness and fear to describe our emotions. Along with sadness, disgust and anger, they are the basic emotions all of us experience. But what are emotions really? Emotions are what we experience as a strong feeling, a response to our surroundings. Scientists don’t know a lot about emotions yet, but they do know that there is one particular part of the brain that plays a very important role — the limbic system.

When we see, hear or feel something, that information is carried to the brain. There, the limbic system detects it, and marks it as mostly pleasant or mostly unpleasant. For example, when someone jumps at you to scare you, that goes into the ‘unpleasant’ category, whereas someone surprising you with your favourite food goes into the ‘pleasant’ category. The two categories each trigger a different part of the limbic system. That part then sends out chemical signals to other systems in the body.

These systems control how your body responds to an emotion. One of them is the autonomic nervous system. Now that Lina is walking home after her date, she still feels all warm inside. Whenever Michael crosses her mind her heart beats just a little faster than usual. She feels so happy she can’t control her smile.

But as soon as she hears footsteps behind her, her heart starts beating much faster. She starts sweating and breathing fast. In both cases Lina’s body is responding to the situation Lina is in. This helps her prepare to react to the situation – for example, talking to Michael about how she feels, or running away from danger. Lina actually feels these changes in her body before she realises what emotion she is experiencing.

This is because her body needs to be prepared as fast as possible in case the situation is dangerous and she needs to get away. Emotions really help us make decisions and take actions in our everyday life. And yet often, everyday life requires us to overcome emotions, just like Michael overcame fear when he asked Lina out. Leon! Don’t ever do that to me, ever again!

You scared me so much! What are you doing out at this time anyway? I was… with a friend… and time just passed so quickly! Oooh what a surprise! Leon’s got a mystery ‘friend'!

Ugh, no, I mean, maybe, I don’t know, what if he doesn’t like me? Come on, don’t be sad! I’m sure he likes you. You need to tell me more about him, but now let’s get home before mum and dad get angry with us for being out this late.