Frequency-specific mechanism links human brain networks for spatial attention.
Selective attention allows us to filter out irrelevant information in the environment and focus neural resources on information relevant to our current goals. Functional brain-imaging studies have identified networks of broadly distributed brain regions that are recruited during different attention processes; however, the dynamics by which these networks enable selection are not well understood. Here, we first used functional MRI to localize dorsal and ventral attention networks in human epileptic subjects undergoing seizure monitoring. We subsequently recorded cortical physiology using subdural electrocorticography during a spatial-attention task to study network dynamics. Attention networks become selectively phase-modulated at low frequencies (δ, θ) during the same task epochs in which they are recruited in functional MRI. This mechanism may alter the excitability of task-relevant regions or their effective connectivity. Furthermore, different attention processes (holding vs. shifting attention) are associated with synchrony at different frequencies, which may minimize unnecessary cross-talk between separate neuronal processes.
Department of Biomedical Engineering, Department of Neurological Surgery, Department of Neurology, Department of Radiology, and Department of Anatomy and Neurobiology, Washington University in St. Louis, St. Louis, MO 63110.
Amy L
AL
Daitch
Mohit
M
Sharma
Jarod L
JL
Roland
Serguei V
SV
Astafiev
David T
DT
Bundy
Charles M
CM
Gaona
Abraham Z
AZ
Snyder
Gordon L
GL
Shulman
Eric C
EC
Leuthardt
Maurizio
M
Corbetta
D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004827:Epilepsy / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009415:Nerve Net / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*