Altered higher-order coupling between brain structure and function with embedded vector representations of...

Area of Science:

• Neuroscience
• Brain Imaging
• Computational Psychiatry

Background:

• Brain function relies on complex direct and indirect regional relationships.
• Understanding higher-order coupling in brain structure and function is crucial for mapping brain dynamics.
• Quantifying connections between non-directly linked brain regions, especially in schizophrenia, remains a challenge.

Purpose of the Study:

• To apply node2vec embedding to characterize brain region features and quantify higher-order coupling.
• To investigate the differences in structural connectivity-functional connectivity (SC-FC) coupling between normal controls and individuals with schizophrenia.
• To identify the role of direct and indirect connections in SC-FC coupling anomalies in schizophrenia.

Main Methods:

• Utilized node2vec embedding to represent features of each brain region (node).
• Calculated pairwise relationships between node embeddings to establish correspondence between brain regions.
• Employed Pearson correlation to quantify higher-order coupling between structural and functional connectivity in normal controls and schizophrenia patients.
• Constructed direct and indirect connections to analyze their respective contributions to coupling.

Main Results:

• Significantly higher higher-order coupling was observed in individuals with schizophrenia compared to controls.
• Anomalous coupling in schizophrenia was predominantly linked to indirect structural connections.
• Indirect structural connections were found to play a critical role in SC-FC coupling.

Conclusions:

• Node2vec embeddings capture subtle network information, offering new insights into SC-FC coupling.
• Indirect structural connections are essential for understanding SC-FC coupling dynamics.
• The brain's structural backbone significantly influences resting-state functional connectivity.