Structured Neural Variability from Repeated Naturalistic Video Watching Experiences.

Area of Science:

• Neuroscience
• Cognitive Science
• Brain Imaging

Background:

• The brain integrates perception and interpretation for environmental navigation.
• It's often assumed neural processes are invariant to repeated experiences.

Purpose of the Study:

• Investigate how neural responses to naturalistic stimuli evolve across multiple viewings.
• Examine changes in brain activity patterns with repeated exposure to visual stimuli.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used.
• Twenty participants viewed 24 short videos across five separate scanning sessions.
• Analyzed between-subject correlations (BSC) and within-subject correlations (WSC) of neural activity.

Main Results:

• BSC decreased with repeated viewing, indicating increased individual variability.
• WSC consistently exceeded BSC, showing individuals are more consistent with themselves than others.
• Early visual cortex showed increasing neural dissimilarity with viewing, reduced feature coupling, and altered default mode network interaction.
• Ventromedial prefrontal cortex (vmPFC) exhibited temporal proximity effects, with activity patterns reflecting session recency rather than viewing number.
• vmPFC temporal structure correlated with participants' fluctuating video preferences.

Conclusions:

• Repeated experiences are processed differently each time.
• Sensory systems adapt to familiar input by altering neural responses.
• Interpretive systems dynamically reshape meaning based on internal states and temporal context.