Mixed emotions may not be mixed after all

As their name would imply, we tend to think of mixed emotions as a blend of different, often contrasting, emotions — but new research suggests that may not be the case.

In their recent paper in Cerebral Cortex, Anthony Vaccaro and team gathered fMRI data from 27 participants as they watched a short film called One Small Step.

Spoilers ahead: the film follows the journey of a young girl as she pursues her childhood dreams of becoming an astronaut, alongside her shoe-making father who supports her along the way. As she grows, she enters university for astrophysics and struggles with her studies, ultimately getting rejected from the astronaut selection program.

Throughout all this, though, her father is ready and waiting with dinner at the ready. One day, she returns and he is no longer there. She's later depicted crying at his grave. While sorting through his belongings, she finds astronaut boots he made for her as a child. This rekindles her motivation, and in the end her efforts are rewarded and she makes it into the astronaut corps. The final scenes of her reaching the moon are interspersed with scenes of her as a child, wearing astronaut boots and playing with her father on her bed.

It's easy to see why this clip was selected to evoke bittersweet feelings. After completing their first watch of the film in the scanner, the participants watched it one more time outside of the scanner, while reporting the valence of emotion that different parts of the film had stirred, as well as times they had cried. The team then compared these two data sets to see what brain activity was occurring alongside positive, negative, and mixed emotions.

What they observed was that at points participants were experiencing mixed emotions, neural activity suggested they weren't just rapidly shifting between positive and negative affective states. Mixed feelings were associated with specific patterns of activity in the amygdala and nucleus accumbens, which differed from patterns seen during exclusively positive and negative emotions. According to the authors, this finding suggests that mixed emotions are a separate emotional experience, rather than being a true 'mix' of two or more feelings.

As if that wasn't cool enough, their analyses also showed that state changes in several areas (specifically the insular cortex, anterior cingulate, amygdala, and nucleus accumbens) allowed them to predict moments when participants would switch between new emotional states.

This work remains to be replicated, but if the conclusions prove to be accurate, the finding that mixed feelings are in fact their own entity could introduce interesting new dynamics to research on emotions.

Read the paper in full:

Vaccaro, A. G., Wu, H., Iyer, R., Shruti Shakthivel, Christie, N. C., Damasio, A., & Kaplan, J. (2024). Neural patterns associated with mixed valence feelings differ in consistency and predictability throughout the brain. Cerebral Cortex, 34(4). https://doi.org/10.1093/cercor/bhae122