a, To test for the possibility that airborne sounds activated the imaged neurons in fS1, the forepaw was moved off the stimulator. To test for the possibility that vibrations propagated through the body to the cochlea, loud white noise was used to mask this hypothetical stimulation. The response change ratios (median ± quartiles) relative to the control condition (zero level) averaged across all frequencies with significant activity increases in the control condition show that with the forepaw off the stimulator, sound alone could not drive increases in Δf/f 0 (P < 10−19, two-sided Wilcoxon signed-rank test, z = −9.22, n = 113 cells, 9 mice) and that the white noise mask had only a small aversive effect on the responses (P = 0.006, z = −2.76, n = 128 cells, 9 mice; dots, single neurons; squares, median ± quartiles). Significant increases in Δf/f 0 could be evoked in none of the individual neurons by sound alone at any frequency (P < 0.01, randomization test). b, A representative fS1 neuron activated by forepaw vibrations (black, control condition) was not responsive to sound alone (green, forepaw off condition) and unaffected by the auditory mask (blue, white noise condition). Top, denoised Δf/f 0 responses evoked by 730-Hz and 1,220-Hz vibrations (thin lines, individual stimulus responses; thick lines, mean response). Bottom, frequency tuning curves tested with four vibration amplitudes, as depicted by the greyscale bar, to cover the extended range of frequencies (dots, individual responses; lines, mean response). Inset, cropped two-photon image depicting the same responding neuron in both conditions (yellow arrow). c, To test whether stimulus-locked motor events could drive neural responses in fS1, we trained mice to reach with their forelimb for the water reward following the series of forepaw vibrations on each trial. d–f, Representative neurons responding to reach onset (d), target onset (e) or around the time of water consumption (f) but not to forepaw vibrations. Left and middle, denoised Δf/f 0 responses to reaching and a chosen vibration frequency, respectively (thin lines, individual stimulus responses; thick lines, mean response; green shading in e, range of reach onset times). Right, frequency tuning (dots, individual responses; lines, mean response). g, Representative neuron responding to forepaw vibrations but not forelimb movements. h, Representative neuron responding to both events but not showing frequency-tuned activity. i, Left, median peak Δf/f 0 during reaching versus at preferred vibration frequency for all imaged neurons (n = 156 cells, 3 mice, 8 FOVs). Inset, enlarged view of the data in the black square. Right, depiction of numbers of neurons responding to vibrotactile stimulation (red cross), reaching onset, target onset or water consumption (blue symbols) or to both events (magenta symbols). Source data