Change-point analysis of single-trial EEG of auditory and visual oddball tasks
The brain rhythms defined by specific frequency-bands of electroencephalography (EEG) signal are generally thought to represent diverse cognitive processes which wax and wane with sub-second resolutions at different parts of the cortex. Furthermore, single-trial analysis of EEG is believed to show more realistic pictures of ongoing and event-related activities of the brain with millisecond resolution. Here, we present a nonparametric multiple change-point detection and estimation method for analysis of single-trial EEG recorded during auditory and visual oddball tasks. In a simple attention task like oddball, the frontal cortex of the brain is responsible for distinguishing and responding appropriately to target and standard events. With sub-second resolution at the frontal cortex, we show that the α-band activity changes according to “inhibition timing” hypothesis and the β-band activity is in line with “maintaining the status quo” hypothesis.