Fig. 3: The majority of speed and angular velocity cells presents conjunctive coding.

a Intersection between angular head velocity (AHV), grid and head direction (HD) cells. The bar on the left shows the proportions of cells qualifying as grid (yellow, 17.8%), HD (blue, 53.3%) and grid x HD (green, 7.7%) cells in the total population. In grey are cells neither coding for HD nor grid. The bar on the right (pink contour) shows the same distribution among cells qualifying as AHV cells (grid: 13.4%; HD: 55.3%; grid x HD: 5.7%). b Scatterplots showing the intersection between grid, HD and AHV scores. Plot on the left: unidirectional – UniDir – AHV: i.e., CCW-AHV and CW-AHV. Plot on the right: bidirectional – BiDir– AHV. The colour code is the same as in (a). A pink contour denotes a modulation by AHV. Dotted lines represent region-averaged classification thresholds, computed to guide the visualisation. c Same as in (a) for speed cells. The red contour bar represents percentages of principal cells within the speed cell population (grid: 18.8%; HD: 35.4%; grid x HD: 3.3%). d Same as in (b) for speed cells. A red contour denotes a modulation by speed. e Examples of the four different kinds of AHV modulated cells, colour coded as in (a). From left to right: AHV tuning curve, HD polar plot, spatial firing rate map, spatial autocorrelogram. f Examples of the four different kinds of speed modulated cells, colour coded as in (c). Same plot as in (e).