Magnetic Resonance Imaging (MRI) system.
MRI is a non-invasive method to capture images of the brain and other head structures by measuring water molecules in tissues using a high magnetic field (3T). By measuring subtle variations in blood flow in different brain areas, we can also assess brain activity and function during specific mental tasks, known as functional MRI. Additionally, diffusion MRI protocols can visualize neural tracts (connections) across brain structures, and spectroscopy protocols measure concentrations of certain metabolites in brain tissues.
Electroencephalography (EEG) and near-infrared spectroscopy (NIRS) system.
EEG and NIRS are two non-invasive neuroimaging techniques that record real-time brain activity. One captures the brain's electrical activity, while the other records brain activity by measuring oxygenation levels through light diffusion and absorption in the head tissues. For data acquisition, a very light cap with EEG or NIRS sensors is placed on the child's head and quickly becomes unnoticeable. Brain activity can thus be recorded using both techniques separately or in combination at rest, during cognitive task performance, or in response to auditory, visual, etc., stimuli.
Additionally, brain activity from two or more individuals can be simultaneously recorded using a method known as hyperscanning. This approach is used to study real-time neurophysiological processes of social interactions and interpersonal relationships, like brain synchrony during parent-child activities, social interactions between children of different ages, or those with various clinical conditions, etc.