The video is depicting electrical activity in the brain. The 3D model of the brain seen in the visualization is derived from magnetic resonance imaging (MRI) data. Electrical activity in the brain is gathered from EEG (electroencephalograph) data. EEG is a non-invasive technology that registers coordinated electrical activity in large groups of neurons through a web of electrodes that are typically worn in a cap that fits over a person’s head.
The golden fibers in the image are myelinated groups of nerve axons called white matter. These axon bundles connect and coordinate communication between different areas of the brain. Signals that pass through the axon bundles are visualized as pulses of light in the video. The different colors that come and go throughout the visualization track activity in different frequency bands (sometimes called “brainwaves”). The brightness of a color indicates the intensity of the activity in a particular frequency band. The model tracks activity in the theta, beta and alpha frequency bands.
Theta, shown in red, is a low frequency band (4 to 7 Hz) that is typically observed in drowsiness or meditation in older children and adults. Beta, shown in green, is a low-to-mid range band (16 to 31 Hz) that is associated with a variety of both mental states and physical activity. For example, beta may be reduced during active movements and increased during anxious thinking. Alpha, shown in blue, is another low frequency band (8 to 15 Hz) that is typically associated with relaxation or closing the eyes. Color mixtures show activity in more than one band. For example, purple shows activity in both the theta and alpha bands.
The visualization seen in the video was made with the Unity3D video game development engine. This is the same game engine that is being used by researchers at the Xerox Research Centre Europe to create virtual scenes that are used to train deep learning networks to solve real-world problems.