Variation is the Norm: Brain State Dynamics Evoked By Emotional Video Clips

TL;DR

This study reveals that brain activity during emotional experiences varies significantly across individuals, challenging the idea of consistent neural biomarkers for specific emotions.

Contribution

The paper introduces a sequential probabilistic model to analyze temporal brain state dynamics during emotional video viewing, emphasizing individual variability.

Findings

Significant variation in brain state occupancy across individuals watching the same emotional videos.

Brain state patterns are highly individualized, with no universal neural signature for specific emotions.

Variation in brain activity may be the norm in emotional processing, not the exception.

Abstract

For the last several decades, emotion research has attempted to identify a "biomarker" or consistent pattern of brain activity to characterize a single category of emotion (e.g., fear) that will remain consistent across all instances of that category, regardless of individual and context. In this study, we investigated variation rather than consistency during emotional experiences while people watched video clips chosen to evoke instances of specific emotion categories. Specifically, we developed a sequential probabilistic approach to model the temporal dynamics in a participant's brain activity during video viewing. We characterized brain states during these clips as distinct state occupancy periods between state transitions in blood oxygen level dependent (BOLD) signal patterns. We found substantial variation in the state occupancy probability distributions across individuals watching the same video, supporting the hypothesis that when it comes to the brain correlates of emotional experience, variation may indeed be the norm.