![]() ![]() The gamma band is selectively increased when active processing of stimuli occurs with attention. The key role which oscillations in the gamma band (>30 Hz) play in brain processes was initially demonstrated in animals, and these findings were subsequently extended to humans. Introduction: The Importance of the High Frequencies of the Electroencephalogram If the artefacts are properly addressed, the neural gamma signal can be uncovered. Recent progress in dealing with these artefacts is described, including either noise cancellation or phased noise template subtraction for power line noise, regression or independent component analysis for correcting extra-ocular muscle activity and mathematical modelling for reducing scalp, face and neck muscle activity. The artefacts of concern originate from: power line noise, saccade-associated contraction of the extra-ocular muscles, activity of muscles in the scalp, face and neck, screen refresh artefacts and activity of the muscles associated with blinking. However, when the human electroencephalogram is recorded on the scalp, this neural high-frequency signal is buried under a range of other electrical signals such that, without careful handling, recordings of the high-frequency electroencephalogram cannot be considered reliable. They are altered in various pathological states, as well as by neuropharmaceuticals, so that they are of interest in drug and clinical investigations. Gamma oscillations (>30 Hz) in the brain are involved in attention, perception and memory.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |