projects | Tong Chen

A few things I’ve built. Featured research projects are pieces of my own work on brain imaging and neurodegenerative disease, each with a paper and code. Below them, AI/ML experiments are interactive systems that run live, entirely in your browser. Click any link to open. (Demos are best in desktop Chrome or Edge.)

Featured research projects

MICCAI 2026

Early accept · top 9%

Research Project · first author

HiLoGraph — Hierarchical-Longitudinal Brain Network Representation Learning

Brain changes in neurodegeneration play out at many spatial scales — regions, subnetworks, the whole brain — and over time across longitudinal scans. HiLoGraph is a graph representation-learning framework that models both at once: a hierarchical view of the brain network, learned jointly across longitudinal timepoints, for tracking disease progression.

Paper · Code

MICCAI 2025

Early accept · top 9%

Research Project · first author

A Unified Continuous Staging Framework for Alzheimer's Disease & Lewy Body Dementia

AD and LBD are usually staged with coarse, discrete clinical labels and studied in isolation — but patients lie on a continuum from mild cognitive impairment to dementia. This work places both diseases on a single continuous staging axis built from hierarchical anatomical features, so a patient's position reflects where they truly sit along that continuum.

Paper · Code

AAIC 2025

Alzheimer's & Dementia

Research Project · first author

Disease Embedding Tree — a Finer-Scale Cortical Representation of the Impairment Continuum

Whole-region summaries are too coarse to capture where cortical disease signatures emerge. The Disease Embedding Tree is a finer-scale cortical representation that embeds the AD/LBD cognitive-impairment continuum at a sub-regional scale.

Paper

Interactive Demo

Disease Progression Explorer

Slide along the cognitive-impairment continuum, from normal through MCI to dementia, and watch atrophy spread across a live brain network — reddening the medial temporal lobe for Alzheimer's, the occipital cortex for Lewy body dementia — on one shared staging axis. An interactive illustration of my Unified Continuous Staging work.

Try it live →

Interactive Demo

Brain Connectome Explorer

The brain as an interactive network — the seven functional subnetworks, hub regions, and the circuits that break down first in Alzheimer's. A general illustration of the kind of network representation my research learns from brain MRI. Raise the threshold, isolate a subnetwork, or highlight the AD-implicated regions.

Try it live →

AI/ML experiments

Interactive machine-learning systems I built to run entirely client-side.

Interactive Demo

Browser LLM Chat

A ChatGPT-style assistant running 100% in your browser via WebGPU — no server, no API key.

Interactive Demo

LLM Agent Visualizer

Watch an LLM agent reason step by step — the Reason → Act → Observe (ReAct) loop, animated.

Interactive Demo

Neural Net Playground

Train a neural network from scratch (backprop hand-written in JS) and watch it learn.

Interactive Demo

Attention Explorer

See what a Transformer looks at — a real BERT's self-attention across every layer and head, live in your browser.

Interactive Demo

Semantic Search / RAG

Search by meaning, not keywords — real sentence embeddings in your browser (the core of RAG).

More experiments

Smaller demos: Tokenizer Playground (the real GPT-4 BPE, live) · LLM Knowledge Graph (any topic as a force-directed graph).

Demos are built with vanilla JavaScript; the models run client-side via WebGPU / WebAssembly. The text you enter never leaves your browser — only the model weights are fetched once from a public CDN.