Overview
Electroencephalography (EEG) records the brain's spontaneous electrical activity over a period of time, as recorded from multiple electrodes placed on the scalp. This simulator maps clinical voltage oscillations using a synthetic biophysical model representing cortical pyramidal neuronal assemblies.
By implementing the international 10-20 standard placement system across sixteen discrete scalp locations (including pre-frontal, frontal, central, parietal, occipital, and temporal regions), this instrument exposes the spatial-temporal dynamics of the cortex. The wave signals generated procedurally mirror real-life biopotentials, capturing synchronous extracellular current flows associated with local field potentials.
Advanced modeling techniques inside the console simulate biological artifacts such as eyeblinks (transient ocular biopotentials observed on pre-frontal arrays Fp1 and Fp2) and continuous pink noise (representing 1/f spectral power decay inherent in normal biological media). This creates an exceptionally rich canvas environment for students, educators, and neural engineering researchers.
How to Use
1. Adjust Modulators: Alter the dynamic brain-state sliders (Attention, Relaxation, Workload) to immediately shift the physiological simulation. Notice how increasing Relaxation elevates Alpha wave amplitude specifically in O1 and O2 channels, simulating alpha-blocking behavior seen during eyes-closed states.
2. Time & Volt Scale Controls: Drag the Time Base Velocity (Speed) and Microvolt Scale (Amplitude) slider controllers. The raw canvases render these modifications instantly with high-contrast oscilloscope sweep patterns.
3. Target Sonification: Select your desired anatomical target using the dropdown selector. The designated scalp coordinate immediately routes to both the Real-Time FFT Spectral display and the audio synthesizer.
4. Auditory Feedback: Toggle the "Audio Feed" button. The simulator uses the Web Audio API to convert raw voltage measurements from the active channel into low-frequency acoustic hums, where volume and sweep rates map directly to real-time microvolt excursions.
Technical Details
The core synthesis engine generates 16 independent channel streams utilizing procedurally generated oscillator arrays at a sample frequency ($f_s$) of 256 Hz. Each clinical band (Delta, Theta, Alpha, Beta, Gamma) is synthesized via independent, phase-shifted differential sine paths.
Spectral densities are mapped dynamically in real-time. Attention values scale the beta and gamma components, Relaxation regulates the alpha component (with a 1.8x spatial multiplier in occipital channels), and Workload controls the theta component. Blink artifacts are modeled as smooth positive half-sine wave injections with randomized 3 to 8 second interval parameters on pre-frontal channels.
Acoustic feedback maps the output frequency spectrum to multi-oscillator waves, creating organic soundscapes that change with the biophysical state. If the selected channel undergoes high Alpha amplitude, the binaural synthesizer drops to deep alpha-associated carrier beats (150 Hz base, frequency-modulated by live neural inputs).
Future Directions
Engineering roadmaps target the integration of web-native Lab Streaming Layer (LSL) sockets, allowing researchers to bind physical Bluetooth neural headbands directly to this browser runtime environment.
We are developing a modular Independent Component Analysis (ICA) sandbox module designed to mathematically isolate eye-blinks, muscle tension (electromyographic noise), and cardiovascular pulse artifact contamination in real-time.
Additionally, future updates will feature a full 3D source localization model mapping scalp surface potential measurements down onto a three-dimensional rendering of the cerebral cortex, providing clinical estimates of deep brain current density pathways in real-time.