Functional connectivity patterns of human magnetoencephalographic recordings: a ‘small-world’ network?

• Published in: Neuroscience letters Vol. 355; no. 1; pp. 25 - 28
• Main Author: Stam, C.J.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 23.01.2004; Elsevier
• Subjects: Action Potentials - physiology; Biological and medical sciences; Brain - anatomy & histology; Brain - physiology; Cognition - physiology; Cortical Synchronization; Electroencephalography; Functional connectivity; Fundamental and applied biological sciences. Psychology; Gamma; Graph theory; Humans; Information processing; Magnetoencephalography; Memory - physiology; Models, Neurological; Nerve Net - anatomy & histology; Nerve Net - physiology; Neural Pathways - anatomy & histology; Neural Pathways - physiology; Small-world network; Synchronization; Vertebrates: nervous system and sense organs; Functional connectivity; Gamma; Magnetoencephalography; Information processing; Small-world network; Graph theory; Synchronization; Human
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2003.10.063

EEG and MEG (magnetoencephalography) are widely used to study functional connectivity between different brain regions. We address the question whether such connectivity patterns display an optimal organization for information processing. MEG recordings of five healthy human subjects were converted to sparsely connected graphs ( N=126; k=15) by applying a suitable threshold to the N∗ N matrix of synchronization strengths. For intermediate frequencies (8–30 Hz) the synchronization patterns were similar to those of an ordered graph with a consistent drop of synchronization strength as a function of distance. For low (<8 Hz) and high (>30 Hz) frequency bands the synchronization patterns displayed the features of a so-called ‘small-world’ network. This might reflect an optimal organization pattern for information processing, connecting any two brain area by only a small number of intermediate steps.