Extended Data Fig. 6: Details of the visual stimulus set and receptive field mapping procedure.

a, Example frames from each type of stimulus. Green arrows indicate direction of motion. The natural scene image is shown illustrative purposes. The natural scene images shown to the mice are from refs. ⁵¹ and ⁵². b, Timing diagram for visual stimulus set #1, known as ‘Brain Observatory 1.1’. c, Timing diagram for visual stimulus set #2, known as ‘Functional Connectivity’. d, Receptive field mapping used 20° diameter drifting gratings flashed for 250 ms in each of 81 randomized locations on the screen. A spike raster for one unit shows the timing of spikes on each of 45 trials with the stimulus at a particular location. Collapsing over trials yields a peristimulus time histogram for each location. Collapsing over time yields a spike count for each spatial bin. A matrix of spike counts represents the receptive field for this unit. e, To calculate receptive field properties, the receptive field is first smoothed with a Gaussian filter, and all pixels above a threshold value are selected. The centre of mass of the above-threshold pixels indicates the receptive field location, while the total number of above-threshold pixels indicates the area. These processing steps are shown for 25 receptive fields randomly chosen from one experiment.