Fig. 6: Speed and angular velocity coding are independent from theta modulation.

a Proportions of unidirectional AHV cells (first row, 31.1%, n = 137), bidirectional AHV cells (second row, 32.9%, n = 145) and speed cells (third row, 62.9%, n = 277) within the population of derivative cells. Dashed bars represent the fraction of theta modulated cells. UniDir-AHV: 12.5%, n = 55; BiDir-AHV: 12.2%, n = 54; speed: 25.9%, n = 114. b Examples of theta modulated (bottom row of each section) and non-modulated (top row each section) derivative cells. The first column shows the firing rate as a function of the angular velocity or speed, the second column shows the time autocorrelogram of the firing rate of the cell. c Power spectrum of cells in (b). First column: power in the range 0–20 Hz; second column: full spectrum (0–200 Hz) (d) Scatterplots of the distribution of theta scores and unidirectional AHV scores (first row), bidirectional AHV scores (second row) and speed scores (third row) in the population. Full black dots represent cell that are theta-modulated but not modulated by AHV or speed; Full coloured dots represent cells modulated by AHV (pink) or speed (red), but not by theta; coloured dots with black contour are cells modulated by both theta and AHV (pink) or speed (red); grey dots represent unclassified cells. e Distribution of speed cells (red, 19.3%), AHV cells (pink, 17.1%), grid cells (yellow, 17.8%), HD cells (blue, 53.3%) and unclassified cells (grey, 30.0%, n = 432) in the whole population. Dashed bars represent the proportions of theta modulated cells in the whole population (white shaded, 42.1%), and in conjunction with speed cells (8.0%), AHV cells (6.6%), grid cells (10.1%), HD cells (24.6%) and unclassified cells (11.1%). f Proportions of theta modulated cells among speed cells (left, red background) and AHV cells (right, pink background). Cells are divided by type: ‘pure speed’ (red, 38.2%), ‘pure AHV’ (pink, 28.6%), conjunctive grid x speed (yellow left, 51.9%), conjunctive grid x AHV (yellow right, 60.6%), conjunctive HD x speed (blue left, 41.8%) and conjunctive HD x AHV (blue right, 43.4%).