Electroencephalography (EEG) is a way of measuring electrical brain activity using electrodes filled with a conductive gel placed on the scalp. EEG is often used to measure the brain's response to certain stimuli, using Event-Related Potentials (ERPs). For example, the N400 component (a negative going deflection peaking approximately 400ms post-stimulus onset) is often used to measure detection of semantic anomalies, or surprise
When collecting EEG data with older adults, there are several practical considerations to keep in mind. These include:
Older adults' scalps are typically more prone to bruising. Therefore, it is good practice to be cautious when applying the conductive gel with the blunt needle that is often used. Otherwise, there is a risk of bleeding.
It is common for older adults to have thinning hair or for them to be bald. This may lead to so-called bridged electrodes, meaning that the gel from two electrodes comes into contact with each other, meaning that their signal is bad. Therefore, researchers should be mindful of not overusing the conductive gel.