Adult 1 Cerebral Cortex 1 Functional Neuroimaging 1 Humans 1 Magnetic Resonance Imaging 1 Models, Theoretical 1 Scalp 1 Spectroscopy, Near-Infrared 1 adult 1 article 1 brain cortex 1 brain region 1 diagnostic imaging 1 functional near-infrared spectroscopy 1 functional neuroimaging 1 human 1 inter-individual anatomical variability 1 light propagation 1 light scattering 1 near infrared spectroscopy 1 nuclear magnetic resonance imaging 1 physiology 1 procedures 1 scalp 1 scalp-cortex correlation theoretical model 1