Synchronous high-amplitude co-fluctuations of functional brain networks during movie-watching

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Functional Neuroimaging

Background:

• Functional connectivity analysis reveals transient, high-amplitude time points called "events."
• These events significantly influence time-averaged connectivity and brain-behavior relationships.
• Event expression differences are linked to hormonal changes and autism spectrum disorder.

Purpose of the Study:

• To investigate the characteristics of neural events during movie watching.
• To determine if these events synchronize across individuals.
• To categorize synchronized events based on their temporal occurrence and properties.

Main Methods:

• Analysis of two independent functional magnetic resonance imaging (fMRI) datasets.
• Participants passively watched movies during scanning.
• Identification and classification of synchronized neural events based on synchronization levels.

Main Results:

• Neural events synchronize across individuals during movie watching.
• Three distinct classes of synchronized events were identified: boundary, during-movie, and non-synchronous.
• Boundary events exhibited higher amplitude, unique co-fluctuation patterns (control/salience activation, visual deactivation), and temporal propagation.
• During-movie events were time-locked to the movie stimulus.
• Brain networks were most similar during synchronous events.

Conclusions:

• Neural events synchronize across individuals, particularly during movie stimuli.
• Synchronized events, especially boundary events, possess unique neurophysiological characteristics.
• Event synchronization provides a framework for understanding inter-brain synchrony and its relation to stimuli.