Marmoset Behavioral Response to Intruder

Testing was conducted similarly to that previously described (49 (link)). Marmosets were separated from their cage mate into the upper-right quadrant of their home cage 8 minutes before the end of the drug pre-treatment time. Following this, an unfamiliar human intruder entered the room and stood 40cm from the cage, maintaining eye contact throughout the 2-minute test period. The intruder was a researcher wearing a realistic human mask (Masks Direct) unfamiliar to the marmoset and wearing familiar scrubs. The order of masks and infusions were counterbalanced across marmosets with at least 2 weeks between each test. Behavior was recorded using a camera (GoPro Hero 5) and a microphone was used to record vocalisations (Sennheiser MKE 400).