Complex Brain Network Analysis and Its Applications to Brain Disorders: A Survey

Table 5

Overview of functional brain network studies in SCZ.

Study	Modality	Subjects	Node definition	Edge definition	Network type	Main findings
Lynall et al., 2010 [111]	fMRI	12 SCZ; 15 HC	72 regions in AAL atlas	Wavelet correlation	Binary	(1) Reduced clustering coefficient and small-world index, reduced probability of high degree hubs, and increased robustness in SCZ.; (2) Reduced degree and clustering coefficient in medial parietal, premotor and cingulate, and right orbitofrontal cortical regions in SCZ.
Su et al., 2015 [112]	fMRI	49 SCZ; 28 HC	90 regions in AAL atlas	Pearson correlation	Weighted	(1) Lower global efficiency in SCZ.; (2) The severity of psychopathology, negative symptoms, and depression and anxiety symptoms were related to global efficiency in SCZ.
Hadley et al., 2016 [113]	fMRI	32 SCZ; 32 HC	278 regions [114]	Wavelet correlation	Binary	(1) Reduced global efficiency and increased clustering coefficients in SCZ.; (2) Aberrant functional integration and segregation in SCZ.
Ganella et al., 2017 [115]	fMRI	42; TR-SCZ; 42 HC	116 regions in AAL atlas	Pearson correlation	Binary	(1) Reduced global brain functional connectivity and reduced strength in frontotemporal, frontooccipital, and temporooccipital connections in TR-SCZ.; (2) Reduced global efficiency and increased local efficiency in TR-SCZ.
Jhung et al., 2013 [116]	EEG	12 SCZ; 13 UHR; 13 HC	64 channels	Synchronization likelihood	Binary	(1) Reduced small-world property in the theta band during the working memory task in SCZ compared with HC.; (2) The small-world index of the UHR was intermediate value among SCZ, UHR, and HC during the working memory task.
Shim et al., 2014 [35]	EEG	34 SCZ; 34 HC	314 dipole sources	Phase locking value	Weighted	(1) Reduced clustering coefficients and increased path lengths in SCZ.; (2) The severity of SCZ symptoms was negatively correlated with the clustering coefficient and positively correlated with path length.
Yin et al., 2017 [87]	EEG	14; P-SCZ; 14; N-SCZ; 14 HC	32 electrodes	Mutual information	Binary	(1) Smaller clustering coefficient, larger average characteristic path length, lower global efficiency, lower local efficiency, and smaller degrees in SCZ.; (2) SCZ patients had fewer information interactions than HCs, and P-SCZ had more information interactions than N-SCZ.