# The effects of sex and age on movie-watching functional connectivity and movie clip classification

## TL;DR

This study explores how sex, age, and movie clips influence brain connectivity patterns during movie watching, revealing distinct neural responses and high classification accuracy.

## Contribution

The study introduces a detailed analysis of sex- and age-specific functional connectivity patterns and their interaction with movie stimuli.

## Key findings

- Females show stronger connectivity in visual, limbic, and default mode networks compared to males.
- Age increases functional connectivity in specific networks during early adulthood.
- Movie clips significantly influence functional connectivity, with high classification accuracy using FC features.

## Abstract

Functional connectivity (FC) is a key tool for understanding the complex interactions within the human brain, highlighting connections between various regions. This study delves into the multifaceted influences shaping functional magnetic resonance imaging FC patterns during movie watching, focusing on the effects of sex, age, and movie clip. Leveraging the Human Connectome Project dataset, we systematically examine FC patterns elicited during movie watching. Notably, sex-specific variations in FC are observed, with females exhibiting heightened FC within visual, limbic, and default mode networks, while males display predominant intra-network connectivity within somatomotor and attention networks. Age-related variations further manifest, revealing FC increases with age in early adulthood (21–35 years old) within some specific networks. Moreover, our investigation unveils the profound influence of movie clips on FC patterns, with significant interactions observed between clips, sex, and age. Feature selection using the Average Cross-Session Correlation method highlights FC as distinct fingerprints of clips, and the Support Vector Machine classifier shows high accuracy (Accuracy > 0.9) when using these features. Our findings underscore the importance of considering individual demographic factors and external stimuli in understanding neural connectivity dynamics during movie-watching, with implications for both basic neuroscience research and clinical neuroimaging applications.

The online version contains supplementary material available at 10.1007/s00429-025-02962-0.