The video above shows a visualization of neural activity in the nematode brain (upper left panel). Each colored sphere represents a neuron, and its location in the drawing above shows the position of that neuron in the worm's head. The size and color of a sphere (upper right) indicates the level of neural activity, with small purple spheres standing for the least amount of activity and the large yellow spheres meaning the most. By watching neurons that grow and shrink, the viewer can get an impression of the range of neural activity in the worm. The lower left and right panels show the worm's movement in real time and the worm's location plotted on a graph. (Video courtesy of Andrew Leifer, Lewis-Sigler Institute for Integrative Genomics)