Posted on January 21, 2023

You’ve just finished up a full day’s work. As you wearily slide into the driver’s seat, readying yourself to face traffic on the way home, you realize you should eat something. You’re on a quest to be healthier and stick to a budget for the new year, and you know you have a stocked fridge at home to make a week’s work of healthy meals. Then you suddenly remember that trendy new bistro you have been dying to try out, known for its decadent (and expensive) menu! That sounds FAR better, so you text a friend to meet you there in five.  

What happened? Welcome to a phenomenon known as decision fatigue. It is estimated that a normal American adult makes about 35,000 decisions every day (Pignatiello, Martin, & Hickman, 2020). These decisions can be as simple as when take a lunch break, or if you are a health care worker, making judgment calls that can impact someone’s life. The act of making so many decisions for an extended period eventually takes a toll. Our brains fatigue, and instead of logical decisions, we can have the tendency to make impulsive ones instead. This concept is based on the idea that we only have a certain amount of ability to regulate our behavior. The more we have to use our mental and emotional resources to make decisions throughout the day, the more we “deplete our ego,” and the less likely we are to exhibit self-control and make “good” decisions later on (Baumeister, Bratslavsky, Muraven, & Tice, 1998).  

We can look deeper inside the brain at a chemical involved in decision-making called dopamine (DA). DA is associated with our brain’s reward system, which is also involved in the cost-benefit analysis our brain undergoes when we make decisions. Our DA balance in an area of the brain called the nucleus accumbens (Nac) is at a normal level when we are not mentally fatigued. We can make decisions that are more mentally “costly” at first but have a rewarding effect later, because we have enough DA hanging around in the NAc. We can wait to get that pleasurable DA boost. If we have been riding this cost-benefit DA trade-off train all day long, the DA levels in the NAc plummet. Now, if we are faced with a decision that is more work at first with but will pay off later, our NAc doesn’t “see” it that way. It wants DA, so it will “convince” us to choose the option that is easiest and promises the biggest, juiciest reward to get its DA fix, ASAP (Boksem & Tops, 2008). So, at the end of the day, the spendy calorie-buster wins out over the thrifty veggie bowl. 

References

Baumeister, R. F., Bratslavsky, E., Muraven, M., & Tice, D. M. (1998). Ego depletion: is the active self a limited resource? J Pers Soc Psychol, 74(5), 1252-1265. doi:10.1037//0022-3514.74.5.1252 

Boksem, M. A., & Tops, M. (2008). Mental fatigue: costs and benefits. Brain Res Rev, 59(1), 125-139. doi:10.1016/j.brainresrev.2008.07.001 

Pignatiello, G. A., Martin, R. J., & Hickman, R. L., Jr. (2020). Decision fatigue: A conceptual analysis. J Health Psychol, 25(1), 123-135. doi:10.1177/1359105318763510