Fig. 1

Training marmoset monkeys to call on command. a Experimental setup. Animals were trained in a double-walled soundproof recording chamber. The schematic block diagram depicts the system used for stimulus presentation, behavioral monitoring, and reward presentation. b Training paradigms. All monkeys were trained in a go/no-go protocol to vocalize whenever a red cue appeared (detection task; upper depiction). One monkey was trained in a successive training period to utter distinct vocalizations in response to red and blue visual cues, respectively (discrimination task; lower depiction). H = hit; M = miss; FA = false alarm; CR = correct rejection. c Spectrograms of representative vocalizations uttered by the experimental animals. d Mean call type distribution of the four monkeys in visual detection sessions. Whiskers indicate standard error (SE)