title: Widespread cortical α-ERD accompanying visual oddball target stimuli is frequency but non-modality specific.
abstract: Previous studies have shown that alpha event-related desynchronization (α-ERD) is associated with reaction to visual stimuli in oddball paradigm, as a reflection of attention allocation and memory updating. The present study tested the hypothesis that it reflects a modality and/or frequency specific mechanism. Electroencephalography (EEG) recordings (64 channels) were performed on 18 healthy subjects during visual, auditory, somatosensory, and pain oddball paradigms. Low- and high-frequency α-rhythm were analyzed on individual basis, and their sources were estimated by low resolution brain electromagnetic tomography (LORETA). α-ERD, served as an index of cortical activation, was computed on the cortical voxel level and compared across the conditions (target vs. non-target), α sub-bands (lower vs. higher frequency), and modalities (visual, auditory, somatosensory, and pain). The results showed that visual α-ERD was mainly generated from occipital cortex for both target and non-target conditions. Its magnitude was enhanced across widespread cortical regions (e.g., bilateral occipital, parietal, and frontal areas) in the target condition and was greater in high-frequency α-band. Finally, α-ERD difference between target and non-target conditions was not higher in visual than that in other control modalities. All these findings indicated that human high-frequency α-ERD reflects cognitive attention processes underlying reaction to oddball target stimuli regardless of stimulus modality.
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Peng
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong, China. Electronic address: yhud@hkucc.hku.hk.
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Developmental and Social Process Psychology, University of Rome "La Sapienza", Rome, Italy.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy; IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Babiloni
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001288:Attention / Q000502:physiology; D001931:Brain Mapping / Q000379:methods*; D003344:Cortical Synchronization / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D009778:Occipital Lobe / Q000502:physiology*; D010146:Pain / Q000523:psychology; D010775:Photic Stimulation
keywords: Alpha event-related desynchronization (α-ERD); Attention; Electroencephalography (EEG); Low resolution brain electromagnetic tomography (LORETA); Visual