Traveling waves in attention networks inherit the rhythms of sensory systems
Attention emerges from coordinated activity across distributed brain regions, each with their own intrinsic rhythm: alpha (7-12Hz) in visual cortex and theta (3-7Hz) in auditory cortex. When attention is sustained on a visual location, alpha power increases over the corresponding ipsilateral hemisphere, a robust neurophysiological marker of sustained visuospatial attention named alpha…
Attention arises from synchronized activity across various brain regions, each possessing its own inherent rhythm. The visual cortex exhibits alpha rhythm (7-12Hz), while the auditory cortex oscillates at theta frequency (3-7Hz). When concentrating on a specific visual spot, alpha power amplifies on the opposite side of the brain, a consistent neurophysiological indicator of prolonged visuospatial attention known as alpha lateralization.
Recent investigations have also observed a lateralized pattern of alpha traveling waves moving from front to back across the cortex during sustained attention, implying that these waves facilitate top-down inter-regional communication within the attention network. The current study aimed to ascertain whether these traveling waves indeed convey top-down attention signals or if they are simply a consequence of sustained visuospatial attention.
To do so, the researchers employed various sensory modalities (auditory cueing and visual stimulation) to activate different sensory cortices while preserving the task as a visual discrimination exercise. By utilizing electroencephalography, they tested the hypothesis that if traveling waves represent attention signals within the network, their frequency should mirror the intrinsic rhythm of the engaged sensory system: theta for auditory cueing and alpha for visual stimulation.
Conversely, if they are merely a byproduct of attention directed towards visual information, their frequency should remain in the alpha range. The findings corroborate the latter hypothesis: auditory cueing triggered lateralized theta traveling waves, while visual stimulation evoked lateralized alpha traveling waves. More importantly, the lateralization of traveling waves in both frequencies correlated with trial-by-trial alpha power lateralization.
In conclusion, attention signals seem to traverse the brain as waves at the intrinsic rhythm of the engaged sensory system, and they dynamically adjust the lateralization of alpha power in regions pertinent to the task at hand.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
