The amount of artifact in the EEG record can vary widely by condition and/or by individual participant. Thus, it is important to examine the amount of EEG data available for analyses after the EEG power and coherence values have been computed by the Fourier analysis software. Each research lab should determine the amount of data they consider to be appropriate for their analyses. It is important to keep in mind that including participants with drastically different amounts of data (e.g., seconds versus minutes) can result in questionable data analyses and conclusions. Furthermore, for research designs where participants are assigned to experimental groups, it is important to verify that the amount of EEG data between the groups (baseline, task-related) is similar. It is also critical to examine the EEG power and coherence values for outliers. As with behavioral datasets, careful handling of the EEG data can help the researcher verify the quality of each EEG recording and the integrity of the dataset.
