title: Frontoparietal EEG alpha-phase synchrony reflects differential attentional demands during word recall and oculomotor dual-tasks.
abstract: To study the relationship between the varying degrees of cognitive load and long-range synchronization among neural networks, we utilized a dual-task paradigm combining concurrent word recall working memory tasks and oculomotor tasks that differentially activate the common frontoparietal (FP) network. We hypothesized that each dual-task combination would generate differential neuronal activation patterns among long-range connection during word retention period. Given that the FP alpha-phase synchronization is involved in attentional top-down processes, one would expect that the long-range synchronization pattern is affected by the degrees of dual-task demand. We measured a single-trial phase locking value in the alpha frequency (8-12 Hz) with electroencephalography in healthy participants. Single-trial phase locking value characterized the synchronization between two brain signals. Our results revealed that different amounts of FP alpha-phase synchronization were produced by different dual-task combinations, particularly during the early phase of the word retention period. These differences were dependent on the individual's working memory capacity and memory load. Our study shows that during dual-task, each oculomotor task, which is subserved by distinct neural network, generates different modulation patterns on long-range neuronal activation and FP alpha-phase synchronization seems to reflect these differential cognitive loads.
authors.affiliation: aCenter for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS) Departments of bBiomedical Engineering cBiological Science, Sungkyunkwan University, Suwon dDepartment of Health Sciences and Technology, Samsung Advanced Institute for Health Science & Technology (SAIHST) eSchool of Business, Sungkyunkwan University, Seoul fCenter for Biosignals, Korea Research Institute of Standards and Science gDepartment of Medical Physics, University of Science and Technology, Daejeon, 16419, Korea.
authors.forename: Gusang
authors.initials: G
authors.lastname: Kwon
authors.forename: Min-Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Sanghyun
authors.initials: S
authors.lastname: Lim
authors.forename: Hyukchan
authors.initials: H
authors.lastname: Kwon
authors.forename: Yong-Ho
authors.initials: YH
authors.lastname: Lee
authors.forename: Kiwoong
authors.initials: K
authors.lastname: Kim
authors.forename: Eun-Ju
authors.initials: EJ
authors.lastname: Lee
authors.forename: Minah
authors.initials: M
authors.lastname: Suh
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001288:Attention / Q000502:physiology*; D004569:Electroencephalography; D058407:Electroencephalography Phase Synchronization; D005133:Eye Movements; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D011939:Mental Recall / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D011932:Reading; D055815:Young Adult