# Similar trajectories of psychological states predict marital satisfaction

## TL;DR

Couples with higher marital satisfaction show similar brain activity patterns when watching movies, suggesting shared mental states.

## Contribution

A new method combining inter-subject trajectory similarity and multi-voxel patterns to assess marital satisfaction.

## Key findings

- Married couples showed higher ISTS than random pairs during movie viewing and resting state.
- ISTS was positively linked to marital satisfaction during movie watching.
- Shared neural event patterns predicted marital satisfaction in couples.

## Abstract

Modern mate selection theories suggest that people are more likely to marrysomeone similar to themselves in terms of numerous attributes. Recent researchhas demonstrated a positive relationship between marital satisfaction andinter-subject correlation (ISC) of neural responses while viewing movies inmarried couples. Nevertheless, conventional ISC methods solely captureinformation about similarity in the temporal evolution of region-averaged neuralresponses, disregarding nuanced spatially distributed response topographies.Here, we integrated ISC and multi-voxel pattern (MVP) analysis to capitalizeinter-subject trajectory similarity (ISTS) of MVP. We demonstrated that marriedcouples showed significantly higher ISTS than randomly selected pairs, duringmovie viewing and resting state. The ISTS was particularly positively associatedwith marital satisfaction in married couples while viewing movies. In order toinvestigate latent “psychological states” characterized byrelatively stable patterns of MVP, a hidden Markov model was used to segment theneural events in married couples during viewing movies. We found the ISTS withinmanually defined events was a strong predictor of marital satisfaction. Theseresults suggest that married couples with high-level marital satisfaction mayexperience similar trajectories of mental states when exposed to a commonmarital-related stimulus, and extend our understanding of the neurobiologicalsignatures of intimate relationship.