In the attempt of understanding what makes humans a different kind of animal, from an anthropological perspective, there is no doubt that the hallmark of the successful evolution of our specie can not be reduced to the idea of having developed a smarter brain, but it rather seems to reside in the ability to optimize a collective behaviour which allows the achievement of goals that a single individual could never achieve if acting alone. One aspect that distinguishes human beings from other species undoubtedly resides on the long-lasting effects of the complexity of social relations among individuals, often achieved through social interactions and cooperation. Despite the importance of such cognitive-motor interrelations between individuals, influencing our daily behaviour, investigations on cognitive and motor functions have been mainly studied in single-brain in action, particularly when these were conducted from a neurophysiological perspective. Here, we will abandon this solipsistic approach and extend, for the first time, the study of motor and cognitive functions, so far investigated on subjects acting individually, to a wider social context with agents performing together with another conspecific. On human subjects the behaviour and EEG responses will be analysed during the joint performance of an attentional task. On non-human primates, instead we will record the neural activity simultaneously from two brains of interacting monkeys, with the aim 1) of analyzing the representation of motor intention wnen performing a given action in different social contexts (individually or together with a partner) and 2) of examining the decision-making processes subtending the choice between cooperating or not, to obtain a desired reward.
The neural mechanisms of cognitive-motor behavior and attentional processes have so far been studied in individual brains, therefore without the influence of the social context on individual¿s neural operations and behavior. However, one of the fundamental aspects of evolutionary success across species is the ability of individuals to interact with their equals. This is particularly true when they desire and/or need to accomplish a common goal requiring the coordination of their actions through a cooperative effort. Despite the importance of these type of interactions, which characterize the behaviour of different species, very little is known about the neural processes associated to inter-individual coordination. In particular, to our knowledge, the only study in which the neuronal activity has been studied during the performance of joint-action tasks has been so far conducted in our lab on non-human primates (Ferrari_Toniolo et al 2019).
The present project will investigate for the first time, the neural representation of the attentional and motivational aspects of the decision-making process related to the choice of cooperating or not with another individual, to obtain a reward. From the behavioral point of view, the experiment will offer an unique opportunity to test in an original fashion the attitude of NHPs to cooperate toward a common goal, in the context of an ad hoc designed experimental protocol. Therefore, the novelty of this study, will consists not only in the analysis of behavioral aspects never studied before in a quantitative fashion, but mainly in a new investigation of the neural mechanisms guiding our primate behavior in a social contexts. We will study the role of frontal cortex, based on the evaluation of the cooperation payoff. This analysis will focus on the neural mechanisms related to the evaluation of the reward magnitude vs. the cost to be paid when coordinating one's own action with that of a co-acting mate.
Furthermore, an additional novelty of the project consists in adopting for the first time within a social (dyadic) context, a paradigm widely used to elicit and measure attention in individual subjects, to assess whether the behavioral and EEG correlates of the attentional performance of each of the two co-actors are similar to those that are observed when each participant performs the same task in isolation.
References:
Ferrari-Toniolo S, Visco-Comandini F, Battaglia-Mayer A. (2019) Two brains in action: Joint-action coding in the primate frontal cortex. J Neurosci, 39 (18), 3514-3528.