@article {4564, title = {Circuit dynamics of approach-avoidance conflict in humans.}, journal = {bioRxiv}, year = {2025}, month = {2025 Jan 01}, abstract = {

Debilitating anxiety is pervasive in the modern world. Choices to approach or avoid are common in everyday life and excessive avoidance is a cardinal feature of all anxiety disorders. Here, we used intracranial EEG to define a distributed prefrontal-limbic circuit dynamics supporting approach and avoidance. Presurgical epilepsy patients (n=20) performed an approach-avoidance conflict decision-making task inspired by the arcade game Pac-Man, where participants trade-off real-time harvesting rewards with potential losses from attack. As patients approached increasing rewards and threats, we found evidence of a limbic circuit mediated by increased theta power in the hippocampus, amygdala, orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC), which then drops rapidly during avoidance. Theta band connectivity between these regions increases during approach and falls during avoidance, with OFC serving as a connector in this circuit with high theta coherence across limbic regions, but also with regions outside of the limbic system, including the lateral prefrontal cortex. Importantly, the degree of OFC-driven connectivity predicts how long participants approach, with enhanced network synchronicity extending approach times. Finally, under ghost attack, the system dynamically switches to a sustained increase in high-frequency activity (70-150Hz) in the middle frontal gyrus (MFG), marking the retreat from the ghost. The results provide evidence for a distributed prefrontal-limbic circuit, mediated by theta oscillations, underlying approach-avoidance conflict.

}, issn = {2692-8205}, doi = {10.1101/2024.12.31.630927}, author = {Staveland, Brooke R and Oberschulte, Julia and Kim-McManus, Olivia and Willie, Jon T and Brunner, Peter and Dastjerdi, Mohammad and Lin, Jack J and Hsu, Ming and Knight, Robert T} } @article {4584, title = {Anatomical registration of intracranial electrodes. Robust model-based localization and deformable smooth brain-shift compensation methods.}, journal = {J Neurosci Methods}, volume = {404}, year = {2024}, month = {2024 Apr}, pages = {110056}, abstract = {

BACKGROUND: Intracranial electrodes are typically localized from post-implantation CT artifacts. Automatic~algorithms localizing low signal-to-noise ratio artifacts and high-density electrode arrays are missing. Additionally, implantation of grids/strips introduces brain deformations, resulting in registration errors when fusing post-implantation CT and pre-implantation MR images. Brain-shift compensation methods project electrode coordinates to cortex, but either fail to produce smooth solutions or do not account for brain deformations.

NEW METHODS: We first introduce GridFit, a model-based fitting approach that simultaneously localizes all electrodes{\textquoteright} CT artifacts in grids, strips, or depth arrays. Second, we present CEPA, a brain-shift compensation algorithm combining orthogonal-based projections, spring-mesh models, and spatial regularization constraints.

RESULTS: We tested GridFit on \~{}6000 simulated scenarios. The localization of CT artifacts showed robust performance under difficult scenarios, such as noise, overlaps, and high-density implants (<1~mm errors). Validation with data from 20 challenging patients showed 99\% accurate localization of the electrodes (3160/3192). We tested CEPA brain-shift compensation with data from 15 patients. Projections accounted for simple mechanical deformation principles with <~0.4~mm errors. The inter-electrode distances smoothly changed across neighbor electrodes, while changes in inter-electrode distances linearly increased with projection distance.

COMPARISON WITH EXISTING METHODS: GridFit succeeded in difficult scenarios that challenged available methods and outperformed visual localization by preserving the inter-electrode distance. CEPA registration errors were smaller than those obtained for well-established alternatives. Additionally, modeling resting-state high-frequency activity in five patients further supported CEPA.

CONCLUSION: GridFit and CEPA are versatile tools for registering intracranial electrode coordinates, providing highly accurate results even in the most challenging implantation scenarios. The methods are implemented in the iElectrodes open-source toolbox.

}, keywords = {Brain, Cerebral Cortex, Electrodes, Electrodes, Implanted, Electroencephalography, Humans, Magnetic Resonance Imaging}, issn = {1872-678X}, doi = {10.1016/j.jneumeth.2024.110056}, author = {Blenkmann, Alejandro Omar and Leske, Sabine Liliana and Llorens, Ana{\"\i}s and Lin, Jack J and Chang, Edward F and Brunner, Peter and Schalk, Gerwin and Ivanovic, Jugoslav and Larsson, P{\r a}l Gunnar and Knight, Robert Thomas and Endestad, Tor and Solbakk, Anne-Kristin} } @article {4561, title = {Anatomical registration of intracranial electrodes. Robust model-based localization and deformable smooth brain-shift compensation methods}, journal = {Journal of Neuroscience Methods}, volume = {404}, year = {2024}, pages = {110056}, author = {Blenkmann, Alejandro Omar and Leske, Sabine Liliana and Llorens, Ana{\"\i}s and Lin, Jack J and Chang, Edward F and Brunner, Peter and Schalk, Gerwin and Ivanovic, Jugoslav and Larsson, P{\r a}l Gunnar and Knight, Robert Thomas and others} } @article {4566, title = {The development of aperiodic neural activity in the human brain.}, journal = {bioRxiv}, year = {2024}, month = {2024 Nov 09}, abstract = {

The neurophysiological mechanisms supporting brain maturation are fundamental to attention and memory capacity across the lifespan. Human brain regions develop at different rates, with many regions developing into the third and fourth decades of life. Here, in this preregistered study (https://osf.io/gsru7), we analyzed intracranial EEG (iEEG) recordings from widespread brain regions in a large developmental cohort. Using task-based (i.e., attention to-be-remembered visual stimuli) and task-free (resting-state) data from 101 children and adults (5.93 - 54.00 years, 63 males; electrodes = 5691), we mapped aperiodic (1/{\textflorin}-like) activity, a proxy of excitation:inhibition (E:I) balance with steeper slopes indexing inhibition and flatter slopes indexing excitation. We reveal that aperiodic slopes flatten with age into young adulthood in both association and sensorimotor cortices, challenging models of early sensorimotor development based on brain structure. In prefrontal cortex (PFC), attentional state modulated age effects, revealing steeper task-based than task-free slopes in adults and the opposite in children, consistent with the development of cognitive control. Age-related differences in task-based slopes also explained age-related gains in memory performance, linking the development of PFC cognitive control to the development of memory. Last, with additional structural imaging measures, we reveal that age-related differences in gray matter volume are differentially associated with aperiodic slopes in association and sensorimotor cortices. Our findings establish developmental trajectories of aperiodic activity in localized brain regions and illuminate the development of PFC inhibitory control during adolescence in the development of attention and memory.

}, issn = {2692-8205}, doi = {10.1101/2024.11.08.622714}, author = {Cross, Zachariah R and Gray, Samantha M and Dede, Adam J O and Rivera, Yessenia M and Yin, Qin and Vahidi, Parisa and Rau, Elias M B and Cyr, Christopher and Holubecki, Ania M and Asano, Eishi and Lin, Jack J and McManus, Olivia Kim and Sattar, Shifteh and Saez, Ignacio and Girgis, Fady and King-Stephens, David and Weber, Peter B and Laxer, Kenneth D and Schuele, Stephan U and Rosenow, Joshua M and Wu, Joyce Y and Lam, Sandi K and Raskin, Jeffrey S and Chang, Edward F and Shaikhouni, Ammar and Brunner, Peter and Roland, Jarod L and Braga, Rodrigo M and Knight, Robert T and Ofen, Noa and Johnson, Elizabeth L} }