EEG is a non-invasive tool for the direct recording of electrical signatures of neural activity via electrodes positioned over the scalp, that has the unique advantage of recording very high time-resolution data, in the order of milliseconds.
A state-of-the art EEG/ERP facility is available at the lab. This facility houses two 32 channels Snyamps amplifiers, a Laser Neurolabs YAP Elen, E-Prime software for the presentation of experimental stimuli, and Brain Vision Analyzer, EEGLAB and BESA softwares for EEG/ERPs data analyses.
By means of Event-related potentials (ERPs) is possible to measure brain activity just before, during, and after an event of interest. Under different experimental conditions, qualitative or quantitative changes may be observed in the morphology of the waveforms, the latency, duration, or amplitude of one/more of the peaks, or their distribution over the scalp. Coherence analyses of EEG oscillations is used to study the dynamic interaction of neuronal assemblies that are distributed within and across different specialized brain regions. Rhythmic neural oscillations and their synchronization provide indices of dynamic and flexible communication between and within the cerebral networks underlying a specific behavior or cognitive function (Fries, 2005). Causal functional connectivity between these EEG signals can also be assessed by means of the Granger causality approach, which allows to examine the direction and strength of the connections between the different brain areas during experimental tasks.
Nowadays, simultaneous EEG recording from pair of participants is possible. This provides the unique opportunity to probe human brain activity while participants interact socially. Techniques to analyze EEG oscillations can be used to test to what extent oscillatory synchronization could emerge between two brains during social interaction (interbrain synchronization) and to establish a causal relation appearing between the estimated cortical signals in the different EEG frequency bands between different brain areas of the two brains (interbrain functional connectivity).