Table 1.

Literature Review. Table summarizing previous reports utilizing partial correlation/ covariance approaches. Table shows the reference, solution adopted to allow partial correlation estimation, number of regions on interest (ROIs) and number of subject included. The general area of scientific inquiry is also noted.

Reference	Conditioning Strategy	# of ROIs/ components	# of Subjects	Scientific Topic
Liu et al., 2008	No conditioning	90	31 controls, 31 schizophrenics	Small world structure in schizophrenia
Balenzuela et al., 2010	No conditioning	90	12 controls, 12 back pain patients	Graph analysis of functional connectivity in lower back pain
Zhang et al., 2011	No conditioning	90	63 controls, 30 MDD	Small world structure in major depressive disorder
Marrelec et al., 2006	Limit # of ROIs	6	7	Motor system organization
Fransson and Marrelec, 2008	Limit # of ROIs	9	17	DMN organization
Zhang et al., 2008	Limit # of ROIs	5	17	Thalamic organization
Liang et al., 2011	ICA dimensionality reduction	38	6 rats	Network organization in the awake rate
Yu et al., 2011	ICA dimensionality reduction	57	19 controls, 19 schizophrenics	Small world structure in schizophrenia
Smith et al., 2013 ^*	ICA dimensionality reduction	22/78	20	Methods development for the connectome project
Varoquaux et al., 2010	L₁ Normalization	122	20	Covariance model selection
Fiecas et al., 2013	L₁ Normalization	90	25	Test-retest reliability assessment
Smith et al., 2013 ^*	L₁ Normalization	22/78	20	Methods development for the connectome project
Ryali et al., 2012	Elastic Net Normalization	90	22	Stability of different regularization techniques
Varoquaux et al., 2012	Markov Structure (L1 and Ledoit-Wolf)	105	12	RSN vs small-world brain organization
Deligianni et al., 2014	Ledoit-Wolf shrinkage	82	17	Relationship between BOLD and EEG functional connectivity

Smith et al., 2013 compared multiple approaches so is presented twice