EEG alpha band dissociation with increasing task demands.
In assuming functional differences between different EEG alpha frequency bands, recent studies emphasize the importance of using narrow (8-10 Hz or 10-12 Hz) instead of broad alpha frequency ranges (8-12 Hz). Due to individual differences in alpha activity, it has also been suggested to adjust alpha frequency bands individually for each participant. The present paper highlights the dissociating role of different task demands on the extent of event-related desynchronization (ERD) in different alpha frequency bands. In analyzing the data of four large-scale EEG studies (with sample sizes of 51, 58, 55, and 66, respectively) employing a wide range of cognitive tasks, we found evidence that the correlations between lower and upper alpha band ERD systematically decline as task demands increase.
Institute of Psychology, University of Graz, Universitaetsplatz 2/III, A-8010 Graz, Austria. andreas.fink@uni-graz.at
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D000328:Adult; D000513:Alpha Rhythm; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D003344:Cortical Synchronization; D004213:Dissociative Disorders; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008606:Mental Processes / Q000502:physiology*; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D015203:Reproducibility of Results; D014705:Verbal Behavior / Q000502:physiology