Fruit flies offer insight into reward-based decisions

Fruit flies offer insight into reward-based decisions


In addition to being a sustainable solution to fast fashion, your favorite thrift store has been the site of some quality vintage pieces. Of course, there are also weekends where you spend hours sorting through musty shoes, but it usually pays off. Or so your brain tells you.

In the animal kingdom, this type of behavior is referred to as matching, and we see it everywhere — in mice, pigeons and yes, even thrifty fashionista. But what is your brain doing when this happens?

Enter the humble fruit fly.

A favored subject for scientists’ studies, research shows fruit flies are capable of decision-making based on their expectations about the likelihood of a reward. In this case, the research team identified the part of the fly’s brain where these value adjustments are made, allowing them to confirm the theory on a smaller, neural-circuit level.

During the experiment, researchers pumped two distinct odors into the arms of a Y-shaped arena. The fly entered and learned to anticipate rewards and base its decision accordingly. Eighty percent of the time, the fly selected the odor that gave 80% of the rewards. Only 20% of the time did it choose the odor that yielded 20% of the rewards.

Why worry about how a fly makes choices? Understanding how even a tiny fly brain processes input into behavior may help researchers better understand how decision-making happens in the brains of larger animals, like people.

This could help advance treatment in diseases like addiction, where the brain’s decision-making system can wreak havoc — perhaps leading to a long-awaited solution. And wouldn’t you like to be a fly on the wall for that?

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