Every day, our brains make thousands of decisions. Some research suggests that we make 2,000 decisions every hour. This is astounding, as it covers trivial choices like picking a restaurant to choices on the job or even major life decisions.
However, some decisions are to do with rewards. Or what we perceive as rewards. Reward-based decisions involve balancing potential wins and losses, and this process is driven by complex neural circuitry.
Let’s look at the recent research, some by Harvard Medical School and Harvard University, to shed light on how the brain handles uncertainty and evaluates risk.
Mouse Studies Reveal “Optimist” and “Pessimist” Neurons
This research isn’t based on books or reading. The professionals have carried out experiments to get discernible results.
For example, using odour-reward tasks in mice, researchers identified two neuron groups in the ventral striatum: one signalling better outcomes, the other worse outcomes.
These groups act like an “optimist” and a “pessimist.” They help the animal anticipate the full spectrum of possible rewards. Silencing either group altered behaviour, and this ultimately shows us how these neurons collectively inform decision-making.
But what about humans?
For humans, these findings suggest that we have similar “optimist” and “pessimist” neural circuits that likely help us weigh potential gains and losses in everyday decisions. This may explain why some people are more risk-seeking or cautious. It could even hint at why conditions like depression or addiction may disrupt normal reward-based decision-making.
Dopamine and the Thrill of Uncertainty
Dopamine activity spikes not only when rewards are received but also when they are uncertain. Human brains love the unknown!
Studies in primates show stronger dopamine responses to unpredictable rewards than to guaranteed ones. This explains why uncertainty feels exciting. Our brains are wired to pay attention when outcomes are unclear, fuelling curiosity and engagement, even when we might lose money or actually not get a prize.
This impact is clearest in extreme sports or gambling. For example, you can join casinos still offering 30 free spins no deposit and find enjoyment in not knowing whether you will win the potential prizes.
Paavo Salonen, Online Casino Expert at Mr. Gamble explained that “We see many players who are drawn to the thrill of the unknown when it comes to casinos and sportsbetting. Many believe most of the fun comes from winning. Dopamine is released when you win. However, it’s the anticipation and potential that drives most players.”
Evolutionary Roots of Risk-Seeking
Though gambling is a new phenomenon in the scale of human history, this thrill-seeking behaviour has always been there. Humans and animals evolved to tolerate risk because uncertain rewards often offered survival advantages, like finding food or new territory without knowing if a tribe has already claimed the land.
The example above seems extremely irrelevant. No one has to forage for food in 2026. Yet modern behaviour, from extreme sports, entrepreneurship, or gambling and gaming, still taps into these ancient circuits. This motivates us to pursue high-variance (also known as risky) outcomes when the potential payoff is high.
Brain Regions Driving Reward-Based Decisions
When you explore neuroscience, it’s always good to have a general idea of parts of the brain and the actions they’re responsible for.
This table summarises the neural systems that encode both the idea of potential rewards and the uncertainty associated with each choice. Damage to these regions can impair anticipatory arousal and lead to maladaptive high-risk decisions.
| Brain Region | What it Controls |
| Ventral striatum | Reward prediction |
| Prefrontal cortex | Risk evaluation |
| Anterior cingulate | Anticipatory arousal |
Modern Life and the “Maybe Effect”
Game developers tend to use these neural pathways when designing new experiences. This leads to digital platforms and games that exploit these uncertainty-driven reward systems with the ultimate goal of you spending more time and money on them.
This also goes for social media apps. These send out random notifications in odd patterns to keep you hooked on the idea of a potential reward. The same goes for randomised bonuses in games. Both of these show signs of natural reward variability, and this keeps dopamine circuits active and basically switched on.
Developers and creators should be careful, though. While these factors can enhance curiosity and learning, excessive unpredictability risks overstimulation and fatigue. There is little legislation surrounding this today, but social media companies are beginning to come under fire for predatory algorithms that keep users on the app when it is not beneficial to them.
Balancing Curiosity and Risk
This neuroscience is built into each and every one of us, yet few of us take the time to understand these neural mechanisms. Education is key here, as understanding this theme allows you to harness uncertainty productively. You can begin setting boundaries and prioritising regular rest to help maintain a healthy balance. Always game, gamble, or scroll mindfully!
