Figure 2.

Infant marmoset's self-monitoring capacity develops during the first two months. (a) Illustration of the possible ways that infant marmosets can avoid overlaps. They can either reset the timing of vocal production, in which case there is no self-monitoring, or they can respond in a shorter time interval than the interval expected by spontaneous calls, in which case there is self-monitoring. The purple and blue boxes represent infant and parental calls, respectively. The orange and green dotted lines indicate the spontaneous and parent—infant inter-call interval lengths, respectively. (b) Average spontaneous (orange line) and parent–infant inter-call intervals (green line). The shaded regions represent the respective 95% confidence intervals. (c) Difference between spontaneous and parent–infant inter-call intervals (grey line). The grey shaded region represents the 95% confidence interval for the difference.