In daily life, all decisions require balancing up whether the rewards (e.g., satisfaction after exercise) are worth the effort. Today, will you socialise after work or stay at home? Can you be bothered to do exercise or shall you just watch TV? How do you decide whether it is worth making extra effort? And why is it that some days this is easier than others?

Most people experience large ups and downs in how motivated they feel. This study found that these “fluctuations” predict how much effort people are willing to make. This is because feeling motivated makes the potential rewards of effort seem more rewarding, both rewards at the time and several hours in the future (even though the rewards themselves are actually the same).

In this study, led by Samuel Hewitt, PhD student, Imaging Neuroscience, UCL Queen Square Institute of Neurology, this was the case regardless of people’s different personalities, genders and characteristics. However, it was even more strongly the case for people who experienced a lower general level of motivation. 

"In day-to-day life, how we feel and whether we decide to do things (or not) can often change very quickly. Smartphones games are a great way to understand how our choices depend on our mental health. In the future, these new research methods may identify how mental health can change over time and affect different aspects of our behaviour." Samuel Hewitt, PhD student, Imaging Neuroscience, UCL Queen Square Institute of Neurology

This work highlights how it is normal to experience big ups and downs in motivation over time and these are important because they change our decisions. This suggests that we should try to learn about the natural fluctuations that each of us experience and remember that everyone is different. If possible, we should design our daily or work life around these ups and downs, for example, by trying to do effortful things when we experience peaks in motivation.
Traditionally, scientists have assumed that mental health and behaviour are pretty stable.

This work highlights that many types of day-to-day decisions may be influenced by how we feel in the moment, suggesting that we are more variable than scientists previously thought. In the future, smartphone games can be used to understand why some people really struggle with motivation, such as when experiencing depression or psychosis, and what we can do to prevent this. 

Links

●    Hewitt et al. Day-to-day fluctuations in motivation drive effort-based decision-making, Proc. Natl. Acad. Sci. U.S.A. 122 (12) e2417964122, https://doi.org/10.1073/pnas.2417964122 (2025).

●   Department of Imaging Neuroscience, UCL Square Institute of Neurology