Test-retest reliability of EEG spectra during a working memory task

Area of Science:

• Neuroscience
• Cognitive Science
• Psychophysiology

Background:

• Inter-individual variation in electroencephalography (EEG) spectra is substantial, even during identical cognitive tasks.
• Understanding the stability of task-induced EEG spectra over extended periods is critical for reliable neuroimaging research.

Purpose of the Study:

• To investigate the longitudinal stability of task-induced EEG power spectra in healthy adults.
• To determine if EEG spectral features remain consistent over intervals exceeding one year.

Main Methods:

• Recorded EEG in 41 healthy adults performing a modified Sternberg task.
• Re-recorded EEG in 20 subjects after 12-40 months, analyzing peak frequency, peak height, and spectral shape.
• Utilized generalized linear models and cross-validation to assess intra-individual stability versus inter-individual variation.

Main Results:

• High intra-individual stability of EEG power spectra was observed over extended periods (12-40 months).
• Spectral shape was the most significant contributor to recognizing individual EEG sessions.
• The model achieved high accuracy (99.3% correct pairwise comparisons, 87.5% sensitivity, 99.5% specificity).

Conclusions:

• Task-induced EEG power spectra exhibit significant intra-individual stability over more than a year, surpassing inter-individual differences.
• This high stability validates the use of interleaved EEG-fMRI measurements and allows for robust assessment of longitudinal cognitive changes.