AI Designers Find Inspiration in Rat Brains

When the rat sees object A, it must lick the nozzle on the left to get a drop of sweet juice; when it sees object B, the juice will be in the right nozzle. But the objects are presented in various orientations, so the rat has to mentally rotate each shape on display and decide if it matches A or B. Interspersed with training sessions are imaging sessions, for which the rats are taken down the hall to another lab where a bulky microscope is draped in black cloth, looking like an old-fashioned photographer's setup. Here, the team uses a two-photon excitation microscope to examine the animal's visual cortex while it's looking at a screen displaying the now-familiar objects A and B, again in various orientations. The microscope records flashes of fluorescence when its laser hits active neurons, and the 3D video shows patterns that resemble green fireflies winking on and off in a summer night. Cox is keen to see how those patterns change as the animal becomes expert at its task.