Human cognition requires the coordination of neural activity across widespread brain networks. Here, we describe a new mechanism for large-scale coordination in the human brain: traveling waves of theta and alpha oscillations. Examining direct brain recordings from neurosurgical patients performing a memory task, we found contiguous clusters of cortex in individual patients with oscillations at specific frequencies within 2 to 15 Hz. These oscillatory clusters displayed spatial phase gradients, indicating that they formed traveling waves that propagated at ∼0.25-0.75 m/s. Traveling waves were relevant behaviorally because their propagation correlated with task events and was more consistent when subjects performed the task well. Human traveling theta and alpha waves can be modeled by a network of coupled oscillators because the direction of wave propagation correlated with the spatial orientation of local frequency gradients. Our findings suggest that oscillations support brain connectivity by organizing neural processes across space and time.

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Summary 14Human cognition requires the coordination of neural activity across widespread brain networks. 15Here we describe a new mechanism for large-scale coordination in the human brain: traveling (which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.

We read with much interest the special article by Frerk and colleagues 1 about recent updated guidelines on the management of unanticipated difficult intubation in adults. The article appears to be very informative and assists in decision making. The authors described use of the scalpel-finger-bougie technique in case of impalpable cricothyroid membrane and suggested a midline vertical skin incision of 8-10 cm directed caudad to cephalad. We found an 8-10 cm length of incision over the trachea to be quite debatable, as it can lead to higher risk of bleeding/oozing from the local tissues making poor visualization of landmarks and risk of infection postoperatively. However, it can help in better palpation of the cricothyroid membrane. 2 We suggest the authors should acknowledge the use of techniques such as infiltration of local anaesthetic along with epinephrine, or the standby measures such as application of cautery (monopolar/bipolar), to stop bleeding at the local site while performing the procedure in an emergency.