An overview of common artifacts in EEG time-series
Below you'll find various examples of EEG artifacts. These examples might help you in detecting artifacts in your own EEG time-series. In our lab we use a semi-automatic procedure that first automatically screens for EEG artifacts, and subsequently the researcher inspects the marked artifacts. This way, false-positives and missed artifacts ca nbe detected.
This example shows movement artifacts (most clearly visible at T8, TP8, and P9) in combination with high-frequency noise (caused by muscle contraction, as well as a poor connection ). These artifacts are marked blue and green in the example. Eye blinks are also visible in this example, most clearly present at the frontal electrodes, coinciding with the VEOG blink activity (bottom channel).
Lead movement and electrode pop
This example shows an electrode movement artifact (CP6) and an electrode pop artifact (P4)
This example shows muscle artifacts over most electrodes. These kinds of artifacts are characterized by high frequency activity that have short duration. You can also see some blink artifacts.
This example shows recurring bursts of muscle artifacts (e.g., being present on the same channel for a second time). Please note that we have used an automatic artifact screening procedure here. That's why some of the muscle artifacts are not detected (as they don't meet the rejection criteria).
This example shows to types of eye-artifacts: a blink detected via the VEOG channel as well as a saccade. The saccade is detected via the HEOG channel. both types of artifacts are mixed into the EEG time-series and are dominant over the frontopolar (Fp-) and anterior-frontal electrodes (AF-) . More frequently observed eye-blink artifacts can be seen in the outer right part of the image (as characterized by a high amplitude activity on the frontopolar & anterior-frontal channels, coinciding with the VEOG activity.