Social Requests and Social Affordances: How They Affect the Kinematics of Motor Sequences during Interactions between Conspecifics

Abstract

The present study aimed at determining whether and what factors affect the control of motor sequences related to interactions between conspecifics. Experiment 1 demonstrated that during interactions between conspecifics guided by the social intention of feeding, a social affordance was activated, which modified the kinematics of sequences constituted by reaching-grasping and placing. This was relative to the same sequence directed to an inanimate target. Experiments 2 and 4 suggested that the related-to-feeding social request emitted by the receiver (i.e. the request gesture of mouth opening) is prerequisite in order to activate a social affordance. Specifically, the two experiments showed that the social request to be fed activated a social affordance even when the sequences directed towards a conspecific were not finalized to feed. Experiment 3 showed that moving inside the peripersonal space of a conspecific, who did not produce any social request, marginally affected the sequence. Finally, experiments 5 and 6 indicated that the gaze of a conspecific is necessary to make a social request effective at activating a social affordance. Summing up, the results of the present study suggest that the control of motor sequences can be changed by the interaction between giver and receiver: the interaction is characterized by a social affordance that the giver activates on the basis of social requests produced by the receiver. The gaze of the receiver is a prerequisite to make a social request effective.

Evidence for right-hand feeding biases in a left-handed population

“…Studies have reported differences in the reach-to-grasp phases of throwing and placing actions (Marteniuk, MacKenzie, Jeannerod, Athenes, & Dugas, 1987), lift and show actions (Ferri et al, 2011) and feed and place actions (Ferri et al, 2010;Flindall & Gonzalez, 2013). As has been previously demonstrated, participants in the current investigation produced smaller MGAs when the target object was to be placed in the mouth, rather than simply in a location near the mouth.…”

Moving attractive virtual agent improves interpersonal coordination stability

“…This result is consistent with recent findings obtained during pick-and-place tasks, indicating that a social affordance was activated when they interact with a human being compared to a non-human agent (Becchio, Sartori, Bulgheroni, & Castiello, 2008;Ferri, Campione, Volta, Gianelli, & Gentilucci, 2011). Participants in Becchio et al's study computed a more appropriate kinematic approach when both picking and placing an object onto a human hand, inferring a more ''careful'' strategy when interacting with a human being.…”

Type of gesture, valence, and gaze modulate the influence of gestures on observer's behaviors

“…Concerning request gestures, this was observed in previous studies where the authors found that the kinematics of reaching-grasping and placing and those of reaching-grasping and lifting were altered by the request gestures “give-me-in-the-hand” (Sartori et al, 2009), “feed-me” (Ferri et al, 2011) and “pour” (Innocenti et al, 2012). The fact that gestures understanding and responses preparing are interlaced processes also comes from a fMRI study (Newman-Norlund et al, 2007).…”