Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG) signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA) to represent EEG signals obtained using a brain-computer interface (BCI) device to detect and interpret cognitive activity. This quaternion-based signa...

The effects of inhibition of locus coeruleus neuronal discharge activity on cortical and hippocampal electroencephalographic activity were examined in halothane-anesthetized rats. A combined recording/infusion probe was used to place 35-150-nl infusions of the alpha 2-noradrenergic agonist, clonidine (1 ng/nl) which inhibits locus coeruleus neuronal discharge activity, immediately adjacent to t...

We introduce methods for signal and associated variability estimation based on hierarchical nonparametric smoothing with application to the Sleep Heart Health Study (SHHS). SHHS is the largest electroencephalographic (EEG) collection of sleep-related data, which contains, at each visit, two quasi-continuous EEG signals for each subject. The signal features extracted from EEG data are then used ...

Objective: A common problem in magnetoencephalographic (MEG) and electroencephalographic (EEG) experimental paradigms relying on the estimation of brain evoked responses is lengthy time experiment, which stems from need to acquire a large number repeated recordings. Using bootstrap approach, we aim at reliably reducing these trials. Methods: To this end, assessed five variants non-parametric bo...

Nine children had simultaneous continuous electroencephalographic monitoring and temperature recording immediately after febrile convulsions. Background electroencephalographic rhythms did not alter with temperature and with one exception, seizure discharges occurred only during sustained high pyrexia.