Spectral dynamics of electroencephalographic activity during auditory information processing

• Published in: Hearing research 2003-02, Vol.176 (1), p.25-41
• Main Authors: Cacace, Anthony T, McFarland, Dennis J
• Format: Article
• Language: English
• Subjects: Adult; Auditory Perception - physiology; Biological and medical sciences; Cortical Synchronization; Discrimination (Psychology); Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Electroencephalography; Event-related brain dynamics; Event-related desynchronization; Event-related synchronization; Evoked Potentials; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Mental Processes - physiology; Middle Aged; Psychophysics; Reaction Time; Spectral analysis; Time domain analysis; Vertebrates: nervous system and sense organs
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(02)00715-3

Dynamics of electroencephalographic (EEG) activity during auditory information processing were evaluated in response to changes in stimulus complexity, stimulus discriminability and attention using the oddball paradigm. In comparison to pre-stimulus baseline conditions, auditory stimulation synchronized EEG activity in delta, theta and alpha frequency bands. Event-related synchronization (ERS) effects were greatest at approximately 3 Hz (theta frequency band), and their magnitude depended on stimulus and task demands. Event-related desynchronization (ERD) of EEG activity was observed in the beta frequency band. This effect was greatest at approximately 21 Hz but occurred only for easily discriminable stimuli in attention-related target conditions. Because active discrimination tasks also required a button-press response with the right hand, ERDs involved more complex responses that may be related to a combination of perceptual, motor and cognitive processes. These results demonstrate that oddball and attention-related EEG responses to auditory stimulation could be characterized in the frequency domain. The specific design and analysis features described herein may prove useful since they provide a simple index of the brain’s response to stimulation while at the same time provide powerful information not contained in typical time domain analysis.