Brain fingerprints along the language hierarchy

Area of Science:

• Neuroscience
• Cognitive Science
• Brain Imaging

Background:

• The brain's functional connectome acts as a unique identifier for individuals.
• The specific neural information contributing to this uniqueness is not well understood.

Purpose of the Study:

• To investigate how individual identifiability changes across different levels of the language processing hierarchy.
• To explore the relationship between task complexity, brain functional connectivity, and individual uniqueness.

Main Methods:

• Functional magnetic resonance imaging (fMRI) scans were acquired from subjects during rest and while listening to stories presented in various formats (backward, scrambled, forward).
• Individual identifiability was assessed by comparing functional connectivity profiles across different scan sessions and tasks.
• Analysis was conducted at the whole-brain and functional network levels, comparing auditory and frontoparietal networks.

Main Results:

• Individual identifiability increased with the complexity of the language task, indicating greater distinguishability in more complex conditions.
• High-order networks, such as the frontoparietal network, showed higher individualization compared to low-order networks like the auditory network.
• Increased individual identifiability correlated with increased inter-subject variability in functional connectivities.

Conclusions:

• Task complexity and hierarchical processing in the brain contribute to individual uniqueness.
• High-order cognitive functions engage more individualized neural patterns.
• These findings enhance understanding of brain individualization and may inform the development of connectivity-based biomarkers.