Biomedical subjects

Pier F Ferrari

Publications and source records attributed to Pier F Ferrari.

3 recordsLinked to original sources

PubMed2006

Do facial gestures, visibility or speed of movement influence gaze following responses in pigtail macaques?

This study investigated whether a human model's facial gestures, speed of head turn and visibility of face influenced gaze-following responses (GFR) in pigtail macaques. A human provided gaze cues by turning her head 90 degrees in one of four directions. Head turns were immediately followed by a facial movement (pucker, eyebrow raise, tongue protrusion, neutral), or were executed swiftly (<0.5 s), slowly (3 s) or whilst facing away from the monkeys. All monkeys reliably followed the gaze in all conditions with no differences between conditions. A greater frequency of GFR was found in females compared to males, and two hypotheses for this finding are discussed.

Animals↗

PubMed2006

Neonatal imitation in rhesus macaques.

The emergence of social behaviors early in life is likely crucial for the development of mother-infant relationships. Some of these behaviors, such as the capacity of neonates to imitate adult facial movements, were previously thought to be limited to humans and perhaps the ape lineage. Here we report the behavioral responses of infant rhesus macaques (Macaca mulatta) to the following human facial and hand gestures: lip smacking, tongue protrusion, mouth opening, hand opening, and opening and closing of eyes (control condition). In the third day of life, infant macaques imitate lip smacking and tongue protrusion. On the first day of life, the model's mouth openings elicited a similar matched behavior (lip smacking) in the infants. These imitative responses are present at an early stage of development, but they are apparently confined to a narrow temporal window. Because lip smacking is a core gesture in face-to-face interactions in macaques, neonatal imitation may serve to tune infants' affiliative responses to the social world. Our findings provide a quantitative description of neonatal imitation in a nonhuman primate species and suggest that these imitative capacities, contrary to what was previously thought, are not unique to the ape and human lineage. We suggest that their evolutionary origins may be traced to affiliative gestures with communicative functions.

Animals↗

PubMed2005

Macaques (Macaca nemestrina) recognize when they are being imitated.

This study investigated whether monkeys recognize when a human experimenter imitates their actions towards an object. Two experimenters faced 10 pigtailed macaques, who were given access to an interesting object. One experimenter imitated the monkeys' object-directed actions, the other performed temporally contingent but structurally different object-directed actions. Results show a significant visual preference for the imitator during manual object manipulations, but not mouthing actions. We argue that the ability to match actions could be based on both visual-visual and kinaesthetic-visual matching skills, and that mirror neurons, which have both visual and motor properties, could serve as a neural basis for recognizing imitation. However, imitation recognition as assessed by visual preference does not necessarily imply the capacity to attribute imitative intentionality to the imitator. The monkeys might implicitly recognize when they are being imitated without deeper insight into the mental processes of others.

Animals↗