Principles of Visualization
Choosing the Right Plot
The way data is plotted can either reveal or conceal the truth. A bar chart, for example, can hide important details about data distribution that other plots make clear. This interactive example demonstrates how four very different datasets can produce the exact same bar chart, a phenomenon known as "Anscombe's quartet".
A simple bar chart showing the mean. Click buttons to see the underlying data.
The Critical Role of Color
Color is a powerful tool, but misleading palettes like the "rainbow" scale can create false patterns and obscure real ones. Perceptually uniform colormaps are designed to represent data accurately. Toggle between palettes to see the difference.
A perceptually uniform 'Viridis' palette ensures changes in color match changes in data.
EEG: Brain Rhythms
Electroencephalography (EEG) measures the brain's electrical activity. Visualizing this high-dimensional data is key to understanding its spatial, temporal, and spectral characteristics. From simple scalp maps to complex network graphs, each visualization offers a different window into brain function.
Topographic Plot
A topoplot shows the spatial distribution of brain activity on the scalp. Here, we simulate increased alpha-band power (8-12 Hz) in the posterior (bottom) electrodes, a common finding during relaxed, eyes-closed states.
Time-Frequency Representation
This plot reveals how oscillatory power changes over time. This example shows a typical Event-Related Spectral Perturbation (ERSP), with an early power increase followed by a later decrease (desynchronization).
ECG & PPG: Heart Signals
Electrocardiography (ECG) measures the heart's electrical pulses, while photoplethysmography (PPG) measures blood volume changes. Together, they provide a comprehensive view of cardiovascular health. Visualizations range from annotating single heartbeats to analyzing long-term heart rate variability (HRV).
Annotated ECG Waveform
A single heartbeat contains key features like the P, QRS, and T waves. Click the buttons to highlight these features on the waveform.
Poincaré Plot of HRV
This plot visualizes beat-to-beat heart rate variability. The shape of the cloud reveals patterns in autonomic nervous system activity. Compare a healthy heart to one in failure.
EMG: Muscle Activation
Electromyography (EMG) records the electrical signals from muscles. Visualizations can reveal the timing of muscle contractions during complex movements like walking, or even deconstruct the signal into the firing patterns of individual motor neurons—the final command from the nervous system to the muscle.
EMG Envelopes in Gait
Comparing the smoothed EMG signal (envelope) between normal and pathological gait reveals clear differences in muscle timing and activation level.
Motor Unit Firing Raster
This advanced visualization shows the firing times of individual motor units. As force increases, more units are recruited (bottom to top) and they fire faster (rate coding).
Advanced Bio-Imaging
Modern microscopy and imaging technologies have shattered previous limits, allowing us to visualize life at the nanoscale and in stunning 3D. These images are not only scientifically profound but also possess incredible aesthetic beauty, revealing the intricate artistry of biology.
Fruit Fly Nervous System
Confocal Microscopy
Cardiac Lymphatic Network
Light-Sheet Microscopy
Cholesterol in the Liver
Scanning Electron Microscopy
Brain Tractography
Diffusion Tensor Imaging (DTI)
Microplastics in Tissue
Photoacoustic Imaging
Self Reflected
Gilding & Scientific Illustration