Corepresentation During Joint Action in Marmoset Monkeys (Callithrix jacchus)

Abstract

Behavioral coordination is a fundamental element of human cooperation. It is facilitated when individuals represent not only their own actions but also those of their partner. Identifying whether action corepresentation is unique to humans or also present in other species is therefore necessary to fully understand the evolution of human cooperation. We used the auditory joint Simon task to assess whether action corepresentation occurs in common marmosets, a monkey species that engages extensively in coordinated action during cooperative infant care. We found that marmosets indeed show a joint Simon effect. Furthermore, when coordinating their behavior in the joint task, they were more likely to look at their partner than in a joint control condition. Corepresentation is thus not unique to humans but also present in the cooperatively breeding marmosets. Since marmosets are small-brained monkeys, our results suggest that routine coordination in space and time, rather than complex cognitive abilities, plays a role in the evolution of corepresentation. Research ArticleHumans are a hyper-cooperative species, and the evolution of human cooperation and its underlying mechanisms continue to be a matter of debate (Richerson et al., 2016;Tomasello & Gonzalez-Cabrera, 2017). Our goal was therefore to investigate whether one such mechanism, namely action corepresentation during joint action, may be present in another highly cooperative primate species, the common marmoset monkey (Callithrix jacchus).When human social partners are jointly engaged in a cooperative task, they corepresent each other's actions-for instance, in the joint Simon task (Sebanz, Knoblich, & Prinz, 2003). This task is based on the individual Simon effect (Simon & Rudell, 1967), which is the compatibility effect arising when an irrelevant feature of a test stimulus interferes with the response, as when a stimulus is played back from one side, whereas the required response is on the opposite side. For instance, in the auditory version (Ruys & Aarts, 2010) of the Simon task (full task), subjects have to learn to discriminate between two sound stimuli, "L" and "R," and choose the corresponding left-or righthand response option. If the stimuli are played back from either the left-hand or the right-hand side of the subject, the task is easier in compatible trials (i.e., when stimulus "L," requiring a left-hand response, is played back from the left-hand side, and stimulus "R," requiring a right-hand response, is played back from the righthand side) than in incompatible trials (i.e., when stimulus "L" is played back from the right-hand side, and stimulus "R" is played back from the left-hand side). This compatibility effect is referred to as the Simon effect. However, when subjects have to solve only half of the task because one response option is not available (i.e., the half task), the corresponding stimulus can be ignored, and the compatibility or Simon effect disappears. Thus, when only one response option is available (e.g., on the right-hand ...

Response Coordination Emerges in Cooperative but Not Competitive Joint Task

“…Several alternative accounts have been proposed to explain the emergence of the JSE (see Prinz, 2015 for a review), including the referential coding account ( Dolk et al, 2011 , 2013 ; Dittrich et al, 2013 ; see Dolk et al, 2014 for a review). The referential coding account proposes that during a joint Go/Nogo Simon task, the presence of any salient action event, generated by a biological or non-biological agent ( Stenzel and Liepelt, 2016 ; Miss and Burkhart, 2018 ), is represented by an action event code. Given the high similarity of the two action events in the Joint Simon task (i.e., pressing a button), participants need to discriminate between internally (one’s own) and externally (the other agent’s) activated events.…”

Reflexive gaze following in common marmoset monkeys

“…Common marmosets are well known for having a peculiar interest in faces [1,2]. Unlike macaques, the species of old world primates studied best, and other non-human primate species, they often engage in mutual gaze, for example in the context of joint action tasks [3]. Many individuals even seek eye contact with their human caretakers (personal observations).…”

Response coordination emerges in cooperative but not competitive joint task

“…Several alternative accounts have been proposed to explain the emergence of the JSE (see Prinz, 2015 for a review), including the referential coding account (Dittrich, Dolk, Rothe-Wulf, Klauer, and Prinz, 2013;Dolk, et al, 2011;Dolk, Hommel, Prinz, and Liepelt, 2013;see Dolk, et al, 2014 for a review). The referential coding account proposes that during a joint Go/Nogo Simon task, the presence of any salient action event, generated by a biological or non-biological agent (Miss and Burkhart, 2018;Stenzel and Liepelt, 2016), is represented by an action event code. Given the high similarity of the two action events in the Joint Simon task (i.e.…”