Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Max Planck School of Cognition, Leipzig, Germany
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Bernstein Center for Computational Neuroscience, Charité – Universitätsmedizin Berlin, Berlin, Germany
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Roche Pharma Research and Early Development, Neuroscience and Rare Diseases, Roche Innovation Center Basel, F. Hoffmann–La Roche Ltd., Basel, Switzerland
LIFE – Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany; Department of Psychology, IU International University of Applied Sciences, Erfurt, Germany; Department of Psychiatry and Psychotherapy, University of Leipzig Medical Center, Leipzig, Germany
LIFE – Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany; Department of Psychiatry and Psychotherapy, University of Leipzig Medical Center, Leipzig, Germany
Department of Psychiatry and Psychotherapy, University of Leipzig Medical Center, Leipzig, Germany
Ulrich Hegerl
Department of Psychiatry, Psychosomatics and Psychotherapy, Goethe University Frankfurt, Frankfurt, Germany
Markus Loffler
LIFE – Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany; Institute for Medical Informatics, Statistics and Epidemiology (IMISE), University of Leipzig, Leipzig, Germany
Arno Villringer
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Clinic for Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
Evoked responses and oscillations represent two major electrophysiological phenomena in the human brain yet the link between them remains rather obscure. Here we show how most frequently studied EEG signals: the P300-evoked response and alpha oscillations (8–12 Hz) can be linked with the baseline-shift mechanism. This mechanism states that oscillations generate evoked responses if oscillations have a non-zero mean and their amplitude is modulated by the stimulus. Therefore, the following predictions should hold: (1) the temporal evolution of P300 and alpha amplitude is similar, (2) spatial localisations of the P300 and alpha amplitude modulation overlap, (3) oscillations are non-zero mean, (4) P300 and alpha amplitude correlate with cognitive scores in a similar fashion. To validate these predictions, we analysed the data set of elderly participants (N=2230, 60–82 years old), using (a) resting-state EEG recordings to quantify the mean of oscillations, (b) the event-related data, to extract parameters of P300 and alpha rhythm amplitude envelope. We showed that P300 is indeed linked to alpha rhythm, according to all four predictions. Our results provide an unifying view on the interdependency of evoked responses and neuronal oscillations and suggest that P300, at least partly, is generated by the modulation of alpha oscillations.
