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Application of Granger Causality Analysis of the Directed Functional Connection in Alzheimer's Disease and Mild Cognitive Impairment
Published on: August 7, 2017
Granger causal time-dependent source connectivity in the somatosensory network.
Lin Gao1, Linda Sommerlade2, Brian Coffman3
11] Institute of Biomedical Engineering, Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China [2] State Key Laboratory of Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P. R. China.
This study reveals transient Granger causal interactions in brain activity using magnetoencephalography. It demonstrates a serial processing pathway for somatosensory information, advancing our understanding of neural dynamics.
Area of Science:
- Neuroscience
- Brain Connectivity
- Signal Processing
Background:
- Understanding brain information processing requires exploring transient Granger causal interactions in neural sources.
- Neural patterns are often confounded by time-dependent dynamics, non-stationarity, and noise.
Purpose of the Study:
- To investigate transient Granger causal interactions in somatosensory evoked magnetoencephalography (MEG) source time-series.
- To apply a novel time-varying connectivity approach to analyze fast-changing information flow in the brain.
Main Methods:
- Utilized source time-series from 306-channel MEG recordings of somatosensory evoked responses in 21 healthy subjects.
- Employed a new time-varying connectivity approach combining renormalised partial directed coherence with state space modelling.
- Performed source analysis to identify the origin of MEG signals.
Main Results:
- Somatosensory evoked MEG was primarily generated from contralateral primary somatosensory cortex (SI) and bilateral secondary somatosensory cortices (SII).
- Transient Granger causality identified a serial processing pathway: SI to SII (contralateral and ipsilateral) and SII to SI/SII (contralateral and ipsilateral).
- Results align with known anatomical connectivity, validating the time-varying connectivity analysis.
Conclusions:
- The novel approach provides new insights into transient cortical dynamic connectivity, surpassing the capabilities of previous methods.
- This study validates a new method for analyzing rapid changes in brain communication pathways.
- Findings support a serial processing model for somatosensory information within the brain.
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