Neural adaptation to a working memory task: A concurrent EEG-FNIRS study

Abstract

Simultaneously recorded electroencephalography (EEG) and functional near infrared spectroscopy (fNIRS) measures from sixteen subjects were used to assess neural correlates of a letter based n-back working memory task. We found that EEG alpha power increased and prefrontal cortical oxygenation decreased with increased practice time for the high memory load condition (2-back), suggesting lower brain activation and a tendency toward the ‘idle’ state. The cortical oxygenation changes for the low memory load conditions (0-back and 1-back) changed very little throughout the training session which the behavioral scores showed high accuracy and a ceiling effect. No significant effect of practice time were found for theta power or the behavioral performance measures.