Low-frequency oscillations in the human temporal lobe change at spatial and cognitive event boundaries during real-world navigation

The ultimate goal of neuroscience is to understand and explain real-world behavior in terms of brain activity, and to use these insights to develop therapeutic approaches for neural disorders. Traditional neuroimaging methods, like fMRI, require participants to be stationary, limiting research studies' complexity and realism. By using mobile recording devices synchronized with intracranial EEG recordings in epilepsy patients with an implanted deep brain recording system, we can study the neural basis of everyday human activities such as navigation and memory encoding in a more natural way that captures the complexity, scale, and functional characteristics of real-world experiences. We asked five RNS participants to learn a 0.75-mile route around campus with only instructions to remember the route well enough to navigate back to the beginning. Subjects walked the route 7-8 times across two days, with the 1st walk guided (encoding) and 6-7 of the walks navigated by the participant themselves (navigation retrieval). Local field potential data between 1-85 Hz was continuously collected throughout each participant's walk synchronized with a suite of 1st person experience sensors at millisecond precision. Findings across all participants suggest that theta band power (5-8 Hz) in the medial and lateral temporal lobe significantly increases when participants are navigating outdoors relative to indoor navigation. We also find evidence that temporal lobe low-frequency oscillatory power changes immediately after participants passed through spatial transitions. Taken together, these initial findings support our hypotheses that medial and lateral temporal lobe activity reliably changes around real-world spatial and cognitive event boundaries.