system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 What in our heads goes off when we predict a note or word in a song and we’re right ?

I’ve always loved singing along to a song and guessing the words that comes next. When I get the words right, a lightbulb goes off in my head, what is that?
gpt
Human brains love seeking out patterns, it's a huge part of how we became the dominant species. To encourage this behaviour, our brain gives us a shot of dopamine when we successfully make a match. The dopamine gives us a feeling of reward.

Interestingly, the dopamine spike actually starts when we're anticipating the payoff, before we even get the reward, which is though to encourage looking for the pattern next time.

On the benign side of things, it's why kids watch the same movie over and over - they get a dopamine kick because they can predict what's coming. It's also why we like memes - they're all about pattern matching.

On the evil side, you've got the social media companies and gambling companies that tailor their experience to drive this behaviour. Scrolling through a bunch of boring posts before finding a gem is by design, as is opening 57 loot crates before you get that epic item.