CITATION LIST

Passive language mapping combining real-time oscillation analysis with cortico-cortical evoked potentials for awake craniotomy

This study combined high-gamma activity (HGA) mapping and cortico-cortical evoked potentials (CCEPs) for language mapping during awake craniotomy. This method requires no active patient participation, which is particularly beneficial for patients with language deficits. The findings suggest that this approach can enhance the precision of functional brain mapping, potentially improving surgical outcomes while preserving essential language functions.

Authors: Yukie Tamura, Hiroshi Ogawa, Christoph Kapeller, Robert Prueckl, Fumiya Takeuchi, Ryogo Anei, Anthony Ritaccio, Christoph Guger, Kyousuke Kamada
Journal: Journal of Neurosurgery
Year: 2016
Reference: (Tamura et al., 2016)

Rapid and Minimum Invasive Functional Brain Mapping by Real-Time Visualization of High Gamma Activity During Awake Craniotomy

This study utilized the cortiQ system for real-time identification of motor and language areas through high-gamma activity (HGA) mapping. Compared to electrical cortical stimulation (ECS), the system achieved 100% sensitivity and specificity, confirming its efficacy and reliability.

Authors: Hiroshi Ogawa, Kyousuke Kamada, Christoph Kapeller, Satoru Hiroshima, Robert Prueckl, Christoph Guger
Journal: World Neurosurgery
Year: 2014
Reference: (Ogawa et al., 2014)

cortiQ-based Real-Time Functional Mapping for Epilepsy Surgery

This study evaluated the cortiQ system for passive, real-time identification of motor, sensory, and language areas during epilepsy surgery. By analyzing high-gamma activity from electrocorticographic signals, cortiQ demonstrated high sensitivity and specificity in localizing motor functions, closely aligning with established mapping techniques. Notably, it identified language areas even when electrical stimulation mapping yielded negative results, highlighting its potential to guide surgical resections while preserving essential brain functions.

Authors: Christoph Kapeller, Milena Korostenskaja, Robert Prueckl, Po-Ching Chen, Ki Heyeong Lee, Michael Westerveld, Christine M. Salinas, Jane C. Cook, James E. Baumgartner, Christoph Guger
Journal: Journal of Clinical Neurophysiology
Year: 2015
Reference: (Kapeller et al., 2015)

cortiQ—Clinical Software for Electrocorticographic Real-Time Functional Mapping of the Eloquent Cortex

This paper presents the cortiQ system, a real-time functional mapping tool for the eloquent cortex using electrocorticography. Compared to traditional electrical cortical stimulation (ECS) mapping, cortiQ offers a significantly faster and more efficient alternative, reducing mapping time from over an hour to a few minutes. Validation in two subjects demonstrated high accuracy, with no false positives and only 1.24% false negatives, confirming the reliability of cortiQ for neurosurgical applications.

Authors: Robert Prueckl, Christoph Kapeller, Christian Potes, Milena Korostenskaja, Gerwin Schalk, Ki H. Lee, Christoph Guge
Conference: 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
Year: 2013
Reference: (Prueckl et al., 2013)

Clinical Impact and Implication of Real-Time Oscillation Analysis for Language Mapping

This study evaluated the cortiQ system for functional brain mapping during awake craniotomies. The results were validated against electrical cortical stimulation (ECS) mapping, showing high sensitivity and specificity, even in noisy surgical environments.

Authors: Hiroshi Ogawa, Kyousuke Kamada, Christoph Kapeller, Robert Prueckl, Fumiya Takeuchi, Satoru Hiroshima, Ryogo Anei, Christoph Guger
Journal: World Neurosurgery
Year: 2017
Reference: (Ogawa et al., 2017)

Rapid and Low-Invasive Functional Brain Mapping by Real-Time Visualization of High Gamma Activity for Awake Craniotomy

This paper presents the architecture and workflow of the cortiQ system and validates its performance through two epilepsy cases. Compared to electrical cortical stimulation (ECS) mapping, the system achieved high sensitivity and specificity.

Authors: Kyousuke Kamada, Hiroshi Ogawa, Christoph Kapeller, Robert Prueckl, and Christoph Guger
Conference: 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
Year: 2014
Reference: (Kamada et al., 2014)

Multi-modal Mapping of the Face Selective Ventral Temporal Cortex–A Group Study With Clinical Implications for ECS, ECoG, and fMRI

This study investigated the localization of face-selective regions in the ventral temporal cortex using three modalities: electrical cortical stimulation (ECS), electrocorticography (ECoG), and functional magnetic resonance imaging (fMRI). Five patients with intractable epilepsy underwent these mapping techniques to identify face-selective areas. Face-selective regions were identified in all patients with fMRI, four patients with ECoG, and two patients with ECS. The findings highlight the potential of combining these modalities for precise functional mapping, which is crucial for preserving critical cognitive functions during neurosurgical procedures.

Authors: Takahiro Sanada, Christoph Kapeller, Michael Jordan, Johannes Grünwald, Takashi Mitsuhashi, Hiroshi Ogawa, Ryohei Anei, and Christoph Guger
Journal: Frontiers in Human Neuroscience
Year: 2021
Reference: (Sanada et al., 2021)

Passive Functional Mapping Guides Electrical Cortical Stimulation for Efficient Determination of Eloquent Cortex in Epilepsy Patients

This study utilized the cortiQ system to integrate real-time functional mapping (RTFM) with electrical cortical stimulation (ECS) for identifying eloquent cortex regions in epilepsy patients. By using RTFM to guide ECS, the approach reduced the number of required electrical stimulations by 40%, significantly lowering procedural risks and improving the patient experience.

Authors: Robert Prueckl, Christoph Kapeller, Johannes Gruenwald, Hiroshi Ogawa, Kyousuke Kamada, Milena Korostenskaja, James Swift, Josef Scharinger, Günter Edlinger, Christoph Guger
Conference: 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
Year: 2017
Reference: (Prueckl et al., 2017)

MORE PUBLIACTIONS…

CITATION LIST

Facephenes and Rainbows: Causal Evidence for Functional and Anatomical Specificity of Face and Color Processing in the Human Brain

This study investigated the causal relationship between specific brain regions and the perception of faces and colors. By applying direct electrical stimulation to face-selective and color-selective regions in patients undergoing neurosurgery, the researchers induced perceptual experiences such as seeing illusory faces (“facephenes”) and color sensations (“rainbows”). These findings provide direct evidence for the functional and anatomical specificity of face and color processing areas in the human brain, enhancing our understanding of how distinct visual information is processed.

Authors: Gerwin Schalk, Christoph Kapeller, Christoph Guger, Hiroshi Ogawa, Satoru Hiroshima, Rosa Lafer-Sousa, Zeynep M. Saygin, Kyousuke Kamada, Nancy Kanwisher
Journal: Proceedings of the National Academy of Sciences (PNAS)
Year: 2017
Reference: (Schalk et al., 2017)

Passive language mapping combining real-time oscillation analysis with cortico-cortical evoked potentials for awake craniotomy

This study combined high-gamma activity (HGA) mapping and cortico-cortical evoked potentials (CCEPs) for language mapping during awake craniotomy. This method requires no active patient participation, which is particularly beneficial for patients with language deficits. The findings suggest that this approach can enhance the precision of functional brain mapping, potentially improving surgical outcomes while preserving essential language functions.

Authors: Yukie Tamura, Hiroshi Ogawa, Christoph Kapeller, Robert Prueckl, Fumiya Takeuchi, Ryogo Anei, Anthony Ritaccio, Christoph Guger, Kyousuke Kamada
Journal: Journal of Neurosurgery
Year: 2016
Reference: (Tamura et al., 2016)

Tailor-Made Surgery Based on Functional Networks for Intractable Epilepsy

This study explores the potential of cortico-cortical evoked potential (CCEP) neuromodulation for tailoring epilepsy surgery based on functional networks. This approach demonstrated the feasibility of neuromodulation in refining surgical planning and improving seizure outcomes. The findings highlight CCEP neuromodulation as a promising tool for optimizing epilepsy treatment by preserving critical functions while disrupting epileptic networks.

Authors: Kyousuke Kamada, Christoph Kapeller, Fumiya Takeuchi, Johannes Gruenwald, and Christoph Guger
Journal: Frontiers in Neurology
Year: 2020
Reference: (Kamada et al., 2020)

Disconnection of the Pathological Connectome for Multifocal Epilepsy Surgery

This study explored the use of high-gamma activity (HGA) mapping and cortico-cortical evoked potential (CCEP) recording for preoperative planning and intraoperative monitoring in epilepsy surgery. By integrating these techniques with tractography, the authors identified and selectively disconnected pathological brain networks in patients with intractable epilepsy. CCEP monitoring confirmed successful network disconnection, leading to long-term seizure freedom in all cases. These findings highlight the potential of HGA and CCEP in improving surgical precision and patient outcomes in epilepsy treatment.

Authors: Kyousuke Kamada, Hiroshi Ogawa, Christoph Kapeller, Robert Prueckl, Satoru Hiroshima, Yukie Tamura, Fumiya Takeuchi, and Christoph Guger
Journal: Journal of Neurosurgery
Year: 2018
Reference: (Kamada et al., 2018)

MORE PUBLIACTIONS…

CITATION LIST

Mapping of the central sulcus using non-invasive ultra-high-density brain recordings

This study utilized ultra-high-density EEG (uHD EEG) and somatosensory evoked potentials (SSEPs) to delineate the central sulcus non-invasively. With 256 channels and precise electrode placement, EEG data were analyzed using peak detection and unsupervised spectral clustering. The findings show a 95.2% classification accuracy of electrodes relative to the central sulcus, comparable to intracranial recordings. This approach enhances functional brain mapping and could advance neurosurgical planning, clinical monitoring, brain-computer interfacing, and rehabilitation.

Authors: Leonhard Schreiner, Michael Jordan, Sebastian Sieghartsleitner, Christoph Kapeller, Harald Pretl, Kyousuke Kamada, Priscella Asman, Nuri F. Ince, Kai J. Miller & Christoph: Guger
Journal: Scientific Reports
Year: 2024
Reference: (Schreiner et al., 2024a)

Individual finger movement decoding using a novel ultra-high-density electroencephalography-based brain-computer interface system

This study employed uHD EEG with flexible electrode grids to decode individual finger movements. Using 256 channels over the contralateral sensorimotor cortex, EEG data were analyzed with mu and beta band power features and classified via a support vector machine (SVM). The system achieved an average classification accuracy of 64.8%, with the highest accuracy of 70.6% for middle versus ring finger movements. These findings highlight the potential of uHD EEG for precise motor decoding, advancing Brain-Computer Interface (BCI) applications for movement control and rehabilitation.

Authors: Hyemin S. Lee, Leonhard Schreiner, Seong-Hyeon Jo, Sebastian Sieghartsleitner, Michael Jordan, Harald Pretl, Christoph Guger & Hyung-Soon Park
Journal: Frontiers in Neuroscience
Year: 2022
Reference: (Lee et al., 2022)

Neural source reconstruction using a novel ultra-high-density EEG system and vibrotactile stimulation of individual fingers

This study utilized the uHD EEG system and the FieldTrip toolbox for neural source reconstruction. Using minimum norm estimation (MNE) and dipole fitting, somatosensory evoked potentials (SEPs) from vibrotactile stimulation were mapped with high spatial precision. Findings confirmed contralateral somatosensory cortex activation and distinct segregation of individual finger responses. This approach enhances noninvasive neural source localization, benefiting clinical diagnostics and neuroscience research.

Authors: Leonhard Schreiner, Sebastian Sieghartsleitner, Fan Cao, Harald Pretl & Christoph Guger
Conference: 46th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)
Year: 2024
Reference: (Schreiner et al., 2024b)

Hand gesture decoding using ultra-high-density EEG

This study investigated the neural representation of high-level hand gestures using uHD EEG. Two subjects performed motor execution and motor imagery with 352 and 256 electrodes over the sensorimotor cortex. Band power features in the mu and beta bands were classified using a linear SVM, achieving mean accuracies of 72.7% and 71.3%, with “rock” vs. “scissors” yielding the highest accuracy. Compared to standard EEG configurations, uHD EEG improved classification by up to 10%. Future work will explore feature reduction and real-time BCI feedback for enhanced performance.

Authors: Leonhard Schreiner, Sebastian Sieghartsleitner, Kathrin Mayr, Harald Pretl & Christoph Guger
Conference: 11th International IEEE/EMBS Conference on Neural Engineering (NER)
Year: 2023
Reference: (Schreiner et al., 2023)

Mapping Neuromuscular Representation of Grasping Movements Using Ultra High-Density EEG and EMG

This study explored neuromuscular coordination during grasping movements using an ultra-high-density EEG/EMG system. Three subjects performed grasping tasks, revealing event-related desynchronization/synchronization (ERD/S) patterns and classification accuracies for EEG and EMG signals. Subject S02 achieved the highest accuracies (69.4% EEG, 97.8% EMG), while S01 had the lowest (64% EEG, 85.4% EMG). The findings suggest a strong relationship between EEG and EMG activity, highlighting the potential for improved BCI performance through multimodal integration.

Authors: Leonhard Schreiner, Pauline Schomaker, Sebastian Sieghartsleitner, Michael Schwarzgruber, Harald Pretl, Andreea I. Sburlea & Christoph Guger
Conference: 9th Graz Brain-Computer Interface Conference
Year: 2024
Reference: (Schreiner, L. et al., 2024)

Increased spatial resolution reveals separated EEG activation of individual finger movements

This study investigated neural representations of single-finger movements using high-density EEG. Two subjects performed voluntary finger movements while 73 ultra-high-density electrodes and nine standard 10-20 electrodes recorded activity over the contralateral sensorimotor cortex. Event-related desynchronization/synchronization (ERD/S) was analyzed in the beta band (13–30 Hz), revealing significant movement-related changes via Wilcoxon signed-rank tests. Topographical plots demonstrated enhanced spatial resolution compared to standard EEG, highlighting the potential of high-density EEG for precise motor mapping in BCI applications.

Authors: Christoph Kapeller, Leonhard Schreiner, Sebastian Sieghartsleitner & Christoph Guger
Conference/Journal: 10th International Brain-Computer Interface Meeting (Kapeller et al., 2023) with detailed Results published in the Master class paper in the Journal of Neural Engineering (Cernera et al., 2025)
Year: 2023 / 2025
References: (Cernera et al., 2025; Kapeller et al., 2023)

Advancing Visual Decoding in EEG: Enhancing Spatial Density in Surface EEG for Decoding Color Perception

This study explored early visual cortex sensitivity using uHD EEG with 512 channels over the occipital region. Three subjects viewed color and black-and-white stimuli while visual evoked potentials (VEPs) were analyzed for temporal dynamics and spatial visualization. A 4-class classification model distinguished red, green, blue, and black-and-white stimuli, achieving an average accuracy of 87.2%. Results showed consistent VEP timing and amplitude, with distinct activation patterns for each stimulus, highlighting the potential of uHD EEG for high-resolution visual processing studies.

Authors: Leonhard Schreiner, Sebastian Sieghartsleitner, Matteo La Rosa, Slobodan Tanackovic, Harald Pretl, Emma Colamarino & Christoph Guger
Conference: IEEE International Conference on Metrology for eXtended Reality, Artificial Intelligence and Neural Engineering (MetroXRAINE)
Year: 2024
Reference: (Schreiner et al., 2024c)

Scaling Law in Neural Data: Non-Invasive Speech Decoding with 175 Hours of EEG Data

This study investigated EEG-based speech decoding for BCIs in an open vocabulary setting. A single participant provided 175 hours of EEG data, analyzed using self-supervised representation learning. The model achieved 48% top-1 and 76% top-10 accuracy, while mitigating myopotential artifacts. Reducing data to 10 hours dropped accuracy to 2.5%, highlighting a strong scaling effect. Increasing data volume enhanced the temporal structure of EEG representations, demonstrating the potential of data-driven speech decoding for neuroprosthetic applications.

Authors: Motoshige Sato, Kenichi Tomeoka, Ilya Horiguchi, Kai Arulkumaran, Ryota Kanai, Shuntaro Sasai
Preprint: arxiv.org
Year: 2024
Reference: (Sato et al., 2024)

Brain-Computer-Interface-Driven Artistic Expression: Real-Time Cognitive Visualization in the Pangolin Scales Animatronic Dress and Screen Dress

This study explores the fusion of BCIs and artistic expression through two interactive wearable projects. The first, a low-channel BCI Screen Dress, uses a 4-channel EEG headband to visualize engagement via animated eyes on embedded screens. The second integrates ultra-high-density EEG into an animatronic dress, translating brain signals into dynamic movements and lighting. Both projects successfully transform cognitive states into interactive art, demonstrating the scalability of BCIs beyond clinical use into fashion, entertainment, and education.

Authors: Leonhard Schreiner, Anouk Wipprecht, Ali Olyanasab, Sebastian Sieghartsleitner, Harald Pretl & Christoph Guger
Journal: Frontiers in Human Neuroscience, Section Brain-Computer Interfaces
Year: 2025
Reference: (Schreiner et al., 2025)

MORE PUBLIACTIONS…