highly significantP < 0.001
S2 as indicated by more sniff time or higher social indexes to S2 than to S1 was highly significant if the ITIs were set at a short interval, 1 or 5 min ( Figure 1B3 , ∗∗∗ P < 0.001), but not at a longer one, 30 min or 6 h ( P > 0.05).