Table 2.

Biological methods by Cohort.

Primary investigator	MRI	EEG	Genetics	Sleep	Startle	Birth weight	HPA	Cardio
Dawson		X Six scalp locations: F3, F4, P3, P4, T3, T4; International 10–20 system. EEG was recorded on a Grass Neurodata Acquisition System (Model 12).					X Cortisol radio immunoassay kits from Pantex	X The Porges-Bohrer moving polynomial algorithm estimates respiratory sinus arrhythmia (RSA), which is a measure of vagus nerve activity or vagal tone
Gotlib	X 1.5-T imaging system (Signa; GE Medical Systems)		X OXTR; Oxytocin receptor gene polymorphism (rs2254298)	X Actiwatch 2 device; Philips Respironics			X Cortisol via Salivettes	X Biopac and ECG using modified lead II configuration scored with Mindware
			5HTTPLR; serotonin-transporter-linked polymorphic region (SLC6A4)
Kovacs		X EEG was recorded at 12 pairs of sites–F3, F4, F7, F8, C3, C4, T7, T8, P3, P4, O1, and O2–using an electrode cap (Electro-Cap International)						X RSA was computed using Fast Fourier transform analysis
Kutcher		X C3 and C4		X Polysomnographic data (Melville Diagnostics Sandman System)
Garber		X Fifteen scalp locations from the 10 to 20 system were used: F3, F4, F7, F8, T3, T4, T5, T6, P3, P4, C3, CZ, C4, Pz, and Fz.
Weissman	X 1.5 T scanner (Siemens Sonata)	X 12 electrodes–F3, F4; F7,F8, C3,C4, T7,T8,P3,P4, P7, P8–using an electrode cap (Electro Cap International)	In progress		X	X

Note: MRI = magnetic resonance imaging; EEG = electroencephalography; HPA=Hypothalamic-pituitary-adrenal axis; T=Tesla; RSA=Respiratory sinus arrhythmia.