Alpha frequency, reaction time, and the speed of processing information

Several experiments indicate that alpha frequency is significantly correlated with the speed of information processing, as measured by reaction times. These data imply that alpha frequency is a timing mechanism for cognitive processes. However, this interpretation contradicts the well-accepted view that there is no single alpha rhythm, but instead an entire population of different alpha oscillations. We present arguments and report data in the attempt to demonstrate that this paradox can be resolved if different states of alpha oscillations are distinguished. The results of the present study show that during a state of desynchronization, task-related shifts in alpha frequency are not ''real'' because they are not related to reaction times. Instead, they most likely reflect power changes in different frequency bands.