EEG

Brief overview of the modality

The electroencephalography (EEG) laboratory houses a Biosemi EEG system. EEG allows for continuous recordings of electrical brain activity with a millisecond time resolution. The EEG signal is a highly rich signal which allows for real time monitoring of brain processes, i.e. real time decoding of thoughts or perecptions. Furthermore, by applying sophisticated analysis methods it is possible to localize where in the brain electrophysiological activity is generated.

The Biosemi System has up to 128 channels mounted in an elastic cap which can be worn comfortably by the participant. The EEG laboratory is acoustically shielded to reduce noise. Stimuli can be presented visually and aurally via Psychtoolbox on a stimulus delivery computer. Simultaneous Eye-tracking is also possible via an Eye-link Eye-tracking system. Electrode positions can be digitized with Polhemus to allow for better source reconstructions.

For data analysis we primarily rely on the FieldTrip, EEGlab and MNE Python toolboxes.

How researchers can access equipment within modality?

To gain access on the EEG there are procedures for training, ethics and project proposals. For the procedures please see the CHBH Operating Procedures and Local Rules.

What research data is produced and what can we understand from this?

The EEG system records ongoing brain activity from humans subjects performing cognitive tasks. The

tasks we use include, but are not limited to attention, motor control, memory, language and speech. This allows for characterizing the brain dynamics – such as neuronal oscillations – associated with a given cognitive function. EEG records the brain activity with a millisecond time-resolution and source modelling approaches allows for localizing where in the brain the activity is activated. As such EEG is an excellent tool for studying the networks engaged in the working brain. Researchers at the CHBH have strong expertise in the role of neuronal oscillations and event-related potentials (ERPs).

How is the modality important in contributing to the CHBH values and principles?

The EEG system is used for conducting fundamental research on cognition as well as to investigate brain dynamics associated with neurological and psychiatric disorders. The data from the EEG system are complementary to data from other techniques housed in the CHBH (such as the MEG, or fMRI). Furthermore, the EEG can be used in combination with other recording techniques (MEG, fMRI) and stimulation techniques (TMS, tES). Therefore, we are integrating the EEG research with other modalities to arrive a synergistic description of brain processes. The research conducted on the EEG system is done in the spirit of open science and we strive to co-register new studies and make our approaches and data freely available.