Fig. 1
Diverse cortical responses and behavioral timing during social facial touch. a The social gap paradigm11. Rats separated on two platforms will reach across the gap to engage in social facial touch. In social facial touch, rats align their snouts and whisk to palpate each other’s faces with their mystacial vibrissae. We recorded the behavior of male and female rats by videography from above in visual darkness under infrared illumination13,16,17. b Anatomical location of vibrissa motor cortex (‘VMC’—the primary motor representation of the mystacial vibrissae), cingulate cortex (‘ACC’—a putative homolog of human/primate anterior cingulate cortex), prelimbic cortex (‘PrL’—a putative homolog of human/primate medial prefrontal cortex), barrel cortex (‘S1’—the primary somatosensory representation of the mystacial vibrissae), and auditory cortex (‘A1’). c Example peri-stimulus time histograms (PSTHs) of touch-activated single neurons (Wilcoxon signed-rank test), aligned to the first whisker-to-whisker touch in each social-touch episode. The raster plot above shows single trials, black dots indicate single spikes, and the vertical line indicates the beginning of social facial touch. The black line below indicates mean firing rate, smoothed with an Alpha kernel (τ = 75 ms); shaded area indicates s.e.m. d Example PSTHs of touch-suppressed single neurons (Wilcoxon signed-rank test), aligned to the first whisker-to-whisker touch in each social-touch episode. Same plotting convention as in (c). e Top: Histograms of touch duration (red) and inter-touch time (blue) of social facial touch episodes. The time axes of both plots are clipped at 10 s. Below: Probability distributions of touch duration (red) and inter-touch interval (blue) of social-touch episodes, plotted on a logarithmic timescale. The two distributions span multiple orders of magnitude and strongly overlap
