"Imagine what it feels like to take a bite of your favorite food. That brief moment of pleasure you feel is your brain's way of registering that the outcome was better than you thought, and it nudges you to repeat actions that lead to these rewarding moments. In the field of psychophysiology, we can better understand something called reward processing by looking at someone's reward-related brain activity. When we experience reward, there is an electrical response in the brain associated with decision-making, motivation, and reward processing. This can be measured using an electroencephalogram, or EEG for short. EEG measures electrical activity of the brain using electrodes that are embedded in a mesh-like cap over a participant's scalp while they complete different types of tasks. We can study reward processing by having participants complete a simple gambling task. In this task, participants are shown two doors, and in each trial, pick a door that reveals either a win, representing monetary gain, or a loss. We can see an electrical response in the brain, known as the reward positivity, which occurs approximately 250 milliseconds after receiving feedback, which is roughly twice the duration of an eye blink. Rewards to reward can provide insight into different features of mental health, such as depression, where a core symptom is the loss of interest or the inability to experience pleasure in typical enjoyable activities, known as anhedonia. Research has shown that people with depression often show a reduced brain response to positive outcomes or feedback, compared to those who do not currently experience depression. Reward processing is a regular part of daily life, important for learning and survival. By leveraging more data, we can begin to understand more about mental health issues such as depression. This time you take a bite of your favorite chocolate cake, you can recognize the positive sensation you feel as reward."