Jiazhen Hong

Jiazhen Hong

AI Research Scientist @ EMOTIV · Ph.D. in Computer Engineering @ Rutgers University

Completed his Ph.D. with Prof. Laleh Najafizadeh at the Integrated Systems & NeuroImaging Laboratory. Now an AI Research Scientist at EMOTIV.

Research focuses on foundation models, LLMs, multimodal learning, and scalable machine learning systems for biomedical and time-series data, spanning distributed training, self-supervised representation learning, local model deployment, and healthcare AI applications.

Research Background

Jiazhen Hong is an AI Research Scientist at EMOTIV and holds a Ph.D. in Computer Engineering from Rutgers University. His research focuses on foundation models, large language models, multimodal learning, and scalable AI systems for biomedical and time-series data. At EMOTIV, he works on large-scale neural foundation models, distributed GPU training, long-context modeling, and transferable representation learning. His broader research spans healthcare AI, assistive technologies, human-centered AI, and locally deployed LLM-integrated systems. He has published in Scientific Reports, IEEE TKDE, IEEE TBME, NeurIPS, ICDM, EMBC, ISBI, and NER. Before Rutgers, he conducted machine learning and biostatistics research for early cancer detection at Harvard Medical School.

Recent Highlights

📢 Journal & Conference Papers

🏆 Awards & Honors

🎉 Career Milestones

Jiazhen Hong, Wei Qian, Yudong Chen, Yuqian Zhang
[IEEE TKDE 2025] IEEE Transactions on Knowledge and Data Engineering
We introduce a geometric framework for k-means that characterizes the structure of local optima in clustering. The approach reveals the geometric relationships between solutions and provides theoretical guarantees for cluster detection under diverse data distributions.
Jiazhen Hong, Weinan Wang, Laleh Najafizadeh
[Nature Portfolio 2026] Scientific Reports
We introduce ChatBCI, a P300 speller that integrates large language models to provide context-driven word prediction during EEG-based spelling. The system significantly reduces keystrokes and writing time (-53% and -62%) while increasing information transfer rate by 229% compared to conventional letter-by-letter BCI spellers.
Jiazhen Hong, Pradyumna Rao, Weinan Wang, Laleh Najafizadeh
[IEEE TBME Special Issue] IEEE Transactions on Biomedical Engineering
We introduce ChatBCI-Assist, an intent-based P300 speller that integrates a locally-deployed large language model with an adaptive stopping strategy for real-time EEG-based communication. The system achieves record-level online performance, reaching 30.7 characters/min (105.2 bits/min ITR) and 147.1 bits/min semantic information transfer rate, enabling faster and more natural sentence composition in practical BCI communication.
SpellerSSL Framework
Jiazhen Hong, Geoff Mackellar, Soheila Ghane
[NeurIPS 2025] The Thirty-ninth Annual Conference on Neural Information Processing Systems
We propose SpellerSSL, a self-supervised learning framework that combines P300 aggregation with cross-domain EEG pretraining to learn generalizable representations for speller BCIs. The method achieves 94% character recognition with only 7 repetitions, reaches 21.86 bits/min information transfer rate, and reduces calibration data requirements by 60%.
EEGM2 Framework
Jiazhen Hong, Geoffrey Mackellar, Soheila Ghane
[IEEE ICDM 2025] IEEE International Conference on Data Mining
We introduce EEGM2, a self-supervised framework for long-sequence EEG modeling that integrates a U-shaped encoder–decoder with the Mamba-2 state-space architecture to achieve linear computational complexity and efficient long-range dependency modeling. The approach improves representation learning for EEG signals, enabling scalable training, faster inference, and strong cross-subject generalization across diverse EEG datasets.
NER 2025
Jiazhen Hong, Laleh Najafizadeh
[IEEE NER 2025] IEEE EMBS 12th Annual International Conference on Neural Engineering
We introduce a novel data-driven dynamic stopping strategy for LLM-based P300 speller BCIs, which adaptively determines when to finalize character selection based on real-time EEG decoding. The method achieves over 260% improvement in information transfer rate compared to traditional fixed-repetition approaches.
EMBC 2025
Jiazhen Hong, Pradyumna Rao, Weinan Wang, Shan Chen, Laleh Najafizadeh
[IEEE EMBC 2025] 47th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
We present ChatBCI4ALS, the first intent-based P300 BCI communication system tailored for individuals with ALS. Online experiments achieve up to 42.16 characters/min typing speed and 128.85 bits/min information transfer rate, significantly advancing real-time BCI communication for assistive applications.
ISBI 2025
Jiazhen Hong, Laleh Najafizadeh
[IEEE ISBI 2025] IEEE International Symposium on Biomedical Imaging
We introduce TopoEEG, an image-based framework that generates sequences of topographic maps from EEG data, preserving both temporal and spatial information for decoding neural dynamics. Leveraging a TimeSformer backbone, the method enables accurate single-trial early detection of P300 responses.
P3T
Jiazhen Hong, Laleh Najafizadeh
[Asilomar ACSSC 2024] 58th Asilomar Conference on Signals, Systems, and Computers
We propose P3T (P300-Transformer), a novel single-trial P300 detector and transfer model designed to optimize the information transfer rate in P300-BCI speller systems while maintaining a high character recognition rate.
EMBC 2022
[IEEE EMBC 2022] 44th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
We propose a deep learning framework utilizing dynamic channel selection for early classification of left and right hand motor imagery tasks, reducing data dimensionality and accelerating real-time BCI decoding.
Selected publications. Bold indicates my name.
2026
[1]
J. Hong, G. Mackellar, and S. Ghane. SAMBA: Toward an EEG Foundation Model via Differential Mamba and Coordinate-Driven Spatial Embedding. NeurIPS 2026, NeurReps Proceedings Track. Workshop
[2]
J. Hong, P. Rao, W. Wang, and L. Najafizadeh. ChatBCI-Assist: An Intent-Based P300 Speller with a Locally-Deployed LLM and Adaptive Stopping Strategy Enabling Record Online Spelling Performance. IEEE Transactions on Biomedical Engineering (TBME), 2026. Journal IEEE
[3]
J. Hong and L. Najafizadeh. Improving Spelling Performance of LLM-based P300 Speller BCIs using Circular Nonadjacent Flashing and Cross-Validated Calibration. IEEE EMBC, 2026. Conference
[4]
P. Rao, J. Hong, W. Wang, and L. Najafizadeh. Llama-4-ALS: A Locally Deployable LLM, Tuned with LoRA and Dynamic Hierarchical Data Augmentation, for Speller-Based AAC. IEEE EMBC, 2026. Conference
[5]
J. Hong, W. Qian, Y. Chen, and Y. Zhang. A Geometric Approach to k-means. IEEE Transactions on Knowledge and Data Engineering (TKDE), 38, 1442–1453, 2026. Journal arXiv IEEE
[6]
A. Subramanian, S. Mai, J. Hong, and L. Najafizadeh. Neural Dynamics of Time Perception Under Acute Pain: An Auditory Temporal Bisection Study. IEEE ISBI, 2026. Conference
2025
[10]
J. Hong and L. Najafizadeh. Enhancing Typing Speed in LLM-based P300 Speller BCIs Using a New Data-Driven Dynamic Stopping Strategy. IEEE EMBS NER, 2025. Conference
[11]
S. Mai, J. Hong, T. Shors, and L. Najafizadeh. Longest Sustained Cortical Activity Duration in Temporal Bisection Task Aligns with Geometric Mean for Log-Spaced Probes. IEEE EMBS NER, 2025. Conference
[12]
J. Hong, P. Rao, W. Wang, S. Chen, and L. Najafizadeh. ChatBCI4ALS: A High-Performance, LLM-Driven Intent-Based BCI Communication System for Individuals with ALS. IEEE EMBC, 2025. Conference
[13]
J. Hong and L. Najafizadeh. TopoEEG: a TimeSformer-Based Topographic Image Representation Method for Single-Trial Early Detection of P300. IEEE ISBI, 2025. Conference
2024
[14]
J. Hong, W. Wang, and L. Najafizadeh. ChatBCI: A Fast P300 Speller BCI Incorporating Generative AI-Based Word Prediction. IEEE Brain Discovery and Neurotechnology Workshop, 2024. Workshop Poster
[15]
J. Hong and L. Najafizadeh. P3T: A Transformer Model for Enhancing Character Recognition Rates in P300 Speller Systems. Asilomar ACSSC, 2024, pp. 514–518. Conference Poster
2022
[16]
J. Hong, F. Shamsi, and L. Najafizadeh. A Deep Learning Framework Based on Dynamic Channel Selection for Early Classification of Left and Right Hand Motor Imagery Tasks. IEEE EMBC, 2022, Glasgow, Scotland, pp. 3550–3553. Conference IEEE Poster
Conference and workshop papers with expanded details.
[1]
Workshop
SAMBA: Toward an EEG Foundation Model via Differential Mamba and Coordinate-Driven Spatial Embedding
J. Hong, G. Mackellar, and S. Ghane
[2]
Conference
Improving Spelling Performance of LLM-based P300 Speller BCIs using Circular Nonadjacent Flashing and Cross-Validated Calibration
J. Hong and L. Najafizadeh
IEEE EMBC, 2026
[3]
Conference
Llama-4-ALS: A Locally Deployable LLM, Tuned with LoRA and Dynamic Hierarchical Data Augmentation, for Speller-Based AAC
P. Rao, J. Hong, W. Wang, and L. Najafizadeh
IEEE EMBC, 2026
[4]
Conference
Neural Dynamics of Time Perception Under Acute Pain: An Auditory Temporal Bisection Study
A. Subramanian, S. Mai, J. Hong, and L. Najafizadeh
IEEE ISBI, 2026
[6]
Workshop
J. Hong, G. Mackellar, and S. Ghane
IEEE ICDM 2025, AI for Time Series Workshop
[7]
Conference
Enhancing Typing Speed in LLM-based P300 Speller BCIs Using a New Data-Driven Dynamic Stopping Strategy
J. Hong and L. Najafizadeh
[8]
Conference
Longest Sustained Cortical Activity Duration in Temporal Bisection Task Aligns with Geometric Mean for Log-Spaced Probes
S. Mai, J. Hong, T. Shors, and L. Najafizadeh
[9]
Conference
ChatBCI4ALS: A High-Performance, LLM-Driven Intent-Based BCI Communication System for Individuals with ALS
J. Hong, P. Rao, W. Wang, S. Chen, and L. Najafizadeh
IEEE EMBC, 2025
[10]
Conference
TopoEEG: a TimeSformer-Based Topographic Image Representation Method for Single-Trial Early Detection of P300
J. Hong and L. Najafizadeh
IEEE ISBI, 2025
[11]
Workshop
ChatBCI: A Fast P300 Speller BCI Incorporating Generative AI-Based Word Prediction
J. Hong, W. Wang, and L. Najafizadeh
IEEE Brain Discovery and Neurotechnology Workshop, 2024
[12]
Conference
P3T: A Transformer Model for Enhancing Character Recognition Rates in P300 Speller Systems
J. Hong and L. Najafizadeh
Asilomar ACSSC, 2024, pp. 514–518
[13]
Manuscripts currently under review.
[1]
Under Review
CORA: Coordinate-Aware ROI Attention for EEG Representation Learning in Cortical Space
J. Hong, S. Mai, and L. Najafizadeh
Journal manuscript under review
[2]
Under Review
Subject-specific Channel Selection Based on Davies-Bouldin Index for EEG Motor Imagery Classification
J. Hong, W. Wang, S. Haghani, and L. Najafizadeh
Journal manuscript under review
[3]
Under Review
A Geometric Spatio-Learnable EEG Foundation Model Across Visual and Auditory Modalities in the Temporal Bisection Task
J. Hong and L. Najafizadeh
Journal manuscript under review

🎓 Advisor

Professor of Electrical & Computer Engineering
Rutgers University

🤝 Collaborators

Neurologist · Dept. of Neurology
Rutgers RWJ Medical School
Associate Professor
University of Wisconsin–Madison
Assistant Professor, ECE
Rutgers University
Co-founder & CTO @ Emotiv · CEO @ Emotiv Research
EMOTIV · Macquarie University
AI/ML Lead · MLE @ Google
University of Melbourne
Postdoctoral Researcher, ECE
Rutgers University
Senior Data Scientist
Novo Nordisk
Ph.D. Mathematical Programming
Cornell University
Ashwini Subramanian
Ph.D. Student, ECE
Rutgers University

🧑‍🎓 Supervised Students

Pradyumna Rao
Ph.D. Student, ECE
Rutgers · 2025–
Logan Pasternak
Ph.D. Student, ECE
Rutgers · 2025–
Siwei Mai
Ph.D. Student, ECE
Rutgers · 2024–
Ankith Kunduru
Undergraduate Student, ECE
Rutgers · 2026–
Joel Paley
Master Student, ECE
Rutgers · 2024
Justin Ding
Master Student, ECE
Rutgers · 2023
William Milne
Master Student, ECE
Rutgers · 2023