Chasing language through the brain: Successive parallel networks Weili Zheng d , Geeth Kavya Minama Reddy a , Falcon Dai a , Ayushi Chandramani a , David Brang b , Scott Hunter c , Michael H. Kohrman h , Sandra Rose a , Marvin Rossi e , James Tao a , Shasha Wu a , Richard Byrne f , David M. Frim g , Peter Warnke g , Vernon L. Towle a,⇑ a Department of Neurology, The University of Chicago, Chicago, IL, USA b Department of Psychology, University of Michigan, Ann Arbor, MI, USA c Department of Psychiatry and Behavioral Neuroscience, The University of Chicago, Chicago, IL, USA d Department of Engineering, The University of Illinois, Chicago, IL, USA e Department of Neurology, Rush University, Chicago, IL, USA f Department of Surgery, Rush University, Chicago, IL, USA g Department of Surgery, The University of Chicago, 5841 S. Maryland Ave, 60487 Chicago, IL, USA h Department of Pediatrics, The University of Chicago, Chicago, IL 60487, USA article info Article history: Accepted 11 October 2020 Available online 31 October 2020 Keywords: Cortical mapping Cortical language networks Functional mapping Electrocorticography ECoG power Gamma activity highlights  High-frequency (gamma) electrocorticographic activity indicates the sequence of cortical activation during different language and memory tasks.  Linguistic cognitive tasks induce successive activations that precede in both parallel and sequential manners across the cortex.  Identifying specific cortical gyri from structural MRI allows grouping functional activations across several patients to describe a common mode of activation for each task. abstract Objective: To describe the spatio-temporal dynamics and interactions during linguistic and memory tasks. Methods: Event-related electrocorticographic (ECoG) spectral patterns obtained during cognitive tasks from 26 epilepsy patients (aged: 9–60 y) were analyzed in order to examine the spatio-temporal patterns of activation of cortical language areas. ECoGs (1024 Hz/channel) were recorded from 1567 subdural elec- trodes and 510 depth electrodes chronically implanted over or within the frontal, parietal, occipital and/ or temporal lobes as part of their surgical work-up for intractable seizures. Six language/memory tasks were performed, which required responding verbally to auditory or visual word stimuli. Detailed analysis of electrode locations allowed combining results across patients. Results: Transient increases in induced ECoG gamma power (70–100 Hz) were observed in response to hearing words (central superior temporal gyrus), reading text and naming pictures (occipital and fusi- form cortex) and speaking (pre-central, post-central and sub-central cortex). Conclusions: Between these activations there was widespread spatial divergence followed by conver- gence of gamma activity that reliably identified cortical areas associated with task-specific processes. Significance: The combined dataset supports the concept of functionally-specific locally parallel language networks that are widely distributed, partially interacting in succession to serve the cognitive and behav- ioral demands of the tasks. Ó 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved. 1. Introduction Beginning with the earliest clinicopathologic stroke studies of the aphasias (Broca, 1865; Wernicke, 1874; Lichtheim, 1885), lan- https://doi.org/10.1016/j.clinph.2020.10.007 1388-2457/Ó 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved. ⇑ Corresponding author at: Department of Neurology, MC-2030, The University of Chicago, 5841 S. Maryland Avenue, Chicago, IL 60637, USA. E-mail address: towle@uchicago.edu (V.L. Towle). Clinical Neurophysiology 132 (2021) 80–93 Contents lists available at ScienceDirect Clinical Neurophysiology journal homepage: www.elsevier.com/locate/clinph