From mirror neurons to joint actions

The discovery of mirror neurons has given rise to a number of interpretations of their functions together with speculations on their potential role in the evolution of specifically human capacities. Thus, mirror neurons have been thought to ground many aspects of human social cognition, including the capacity to engage in cooperative collective actions and to understand them. We propose an evaluation of this latter claim. On the one hand, we will argue that mirror neurons do not by themselves provide a sufficient basis for the forms of agentive understanding and shared intentionality involved in cooperative collective actions. On the other hand, we will also argue that mirror neurons can nevertheless play an important role in an account of the production and understanding of joint action, insofar as they provide the basic constituents of implicit agent-neutral representations and are useful elements in a process of online mutual adjustment of participants' actions

Complementary actions

Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person). Successful complementary interactions are founded on the abilities: (i) to simulate another person's movements, (ii) to predict another person's future action/s, (iii) to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv) to complete the social interaction by integrating the predicted effects of one's own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception-action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions

Complementary Actions

Human beings come into the world wired for social interaction. At the fourteenth week of gestation, twin fetuses already display interactive movements specifically directed towards their co- twin. Readiness for social interaction is also clearly expressed by the newborn who imitate facial gestures, suggesting that there is a common representation mediating action observation and execution. While actions that are observed and those that are planned seem to be functionally equivalent, it is unclear if the visual representation of an observed action inevitably leads to its motor representation. This is particularly true with regard to complementary actions (from the Latin complementum ; i.e. that fills up), a specific class of movements which differ, while interacting, with observed ones. In geometry, angles are defined as complementary if they form a right angle. In art and design, complementary colors are color pairs that, when combined in the right proportions, produce white or black. As a working definition, complementary actions refer here to any form of social interaction wherein two (or more) individuals complete each other\u2019s actions in a balanced way. Successful complementary interactions are founded on the abilities:\ua0 (1)\ua0 to simulate another person\u2019s movements; (2)\ua0 to predict another person\u2019s future action/ s; (3)\ua0to produce an appropriate congruent/ incongruent response that completes the other person\u2019s action/ s; and (4)\ua0to integrate the predicted effects of one\u2019s own and another person\u2019s actions. It is the neurophysiological mechanism that underlies this process which forms the main theme of this chapte

Two brains in action: joint-action coding in the primate frontal cortex

Daily life often requires the coordination of our actions with those of another partner. After sixty years (1968-2018) of behavioral neurophysiology of motor control, the neural mechanisms which allow such coordination in primates are unknown. We studied this issue by recording cell activity simultaneously from dorsal premotor cortex (PMd) of two male interacting monkeys trained to coordinate their hand forces to achieve a common goal. We found a population of 'joint-action cells' that discharged preferentially when monkeys cooperated in the task. This modulation was predictive in nature, since in most cells neural activity led in time the changes of the "own" and of the "other" behavior. These neurons encoded the joint-performance more accurately than 'canonical action-related cells', activated by the action per se, regardless of the individual vs. interactive context. A decoding of joint-action was obtained by combining the two brains activities, using cells with directional properties distinguished from those associated to the 'solo' behaviors. Action observation-related activity studied when one monkey observed the consequences of the partner's behavior, i.e. the cursor's motion on the screen, did not sharpen the accuracy of 'joint-action cells' representation, suggesting that it plays no major role in encoding joint-action. When monkeys performed with a non-interactive partner, such as a computer, 'joint-action cells' representation of the "other" (non-cooperative) behavior was significantly degraded. These findings provide evidence of how premotor neurons integrate the time-varying representation of the self-action with that of a co-actor, thus offering a neural substrate for successful visuo-motor coordination between individuals.SIGNIFICANT STATEMENTThe neural bases of inter-subject motor coordination were studied by recording cell activity simultaneously from the frontal cortex of two interacting monkeys, trained to coordinate their hand forces to achieve a common goal. We found a new class of cells, preferentially active when the monkeys cooperated, rather than when the same action was performed individually. These 'joint-action neurons' offered a neural representation of joint-behaviors by far more accurate than that provided by the canonical action-related cells, modulated by the action per se regardless of the individual/interactive context. A neural representation of joint-performance was obtained by combining the activity recorded from the two brains. Our findings offer the first evidence concerning neural mechanisms subtending interactive visuo-motor coordination between co-acting agents

Imitation, mirror neurons and autism

Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show activity in relation both to specific actions performed by self and matching actions performed by others, providing a potential bridge between minds. MN systems exist in primates without imitative and ‘theory of mind’ abilities and we suggest that in order for them to have become utilized to perform social cognitive functions, sophisticated cortical neuronal systems have evolved in which MNs function as key elements. Early developmental failures of MN systems are likely to result in a consequent cascade of developmental impairments characterised by the clinical syndrome of autism

Better Vision Through Manipulation

For the purposes of manipulation, we would like to know what parts of the environment are physically coherent ensembles - that is, which parts will move together, and which are more or less independent. It takes a great deal of experience before this judgement can be made from purely visual information. This paper develops active strategies for acquiring that experience through experimental manipulation, using tight correlations between arm motion and optic flow to detect both the arm itself and the boundaries of objects with which it comes into contact. We argue that following causal chains of events out from the robot's body into the environment allows for a very natural developmental progression of visual competence, and relate this idea to results in neuroscience

Being-in-the-world-with: Presence Meets Social And Cognitive Neuroscience

In this chapter we will discuss the concepts of “presence” (Inner Presence) and “social presence” (Co-presence) within a cognitive and ecological perspective. Specifically, we claim that the concepts of “presence” and “social presence” are the possible links between self, action, communication and culture. In the first section we will provide a capsule view of Heidegger’s work by examining the two main features of the Heideggerian concept of “being”: spatiality and “being with”. We argue that different visions from social and cognitive sciences – Situated Cognition, Embodied Cognition, Enactive Approach, Situated Simulation, Covert Imitation - and discoveries from neuroscience – Mirror and Canonical Neurons - have many contact points with this view. In particular, these data suggest that our conceptual system dynamically produces contextualized representations (simulations) that support grounded action in different situations. This is allowed by a common coding – the motor code – shared by perception, action and concepts. This common coding also allows the subject for natively recognizing actions done by other selves within the phenomenological contents. In this picture we argue that the role of presence and social presence is to allow the process of self-identification through the separation between “self” and “other,” and between “internal” and “external”. Finally, implications of this position for communication and media studies are discussed by way of conclusion

Rethinking Phylogeny and Ontogeny in Hominin Brain Evolution

Theories of hominin and human cognitive evolution have traditionally focused on the phylogeny of the human brain, and on comparisons of human and primate brains in relation to social or ecological variables. Far less attention has been paid to ontogenetic processes, despite the recognition that experience has a profound influence on adult cognition. In this paper we discuss the interplay between phylogeny and ontogeny by examining relationships between human brain size, developmental scheduling and cognition. The correlates of large brains include not only altered subsistence and life-history strategies to meet associated energetic costs, but also on macro- and micro-scale structural adaptations required to meet increased processing costs. This means that larger brains are of necessity more highly interconnected brains, with higher degrees of folding of the neocortex (gyrification) and higher ratios of myelinated connections between neurons (white matter) to neurons themselves (grey matter). Here we argue that the combination of these evolutionary trends underpins the complexity of human behaviour, as the neural circuits involved in cognitive mechanisms such as the mirror neuron system (the system governing motor emulation and imitation) and theory of mind (fundamental in social cognition) mature only slowly, and require considerable socially-scaffolded experience to develop to their full potential. These abilities are likely to be fundamental in characteristically human behaviours such as the cultural transmission of complex forms of tool manufacture and use, attested to in the archaeological record. Their elaborated modern human forms, we argue, are possible only in the context of the evolution of relatively slower trajectories of brain growth and hence longer periods during which the growing brain can be influenced by experience among modern humans relative to other primates. Here we review some of the differences in ontogenetic brain development between humans and other primates, and compare the rates and trajectories of neural development between ourselves and our closest living relatives the chimpanzees to suggest that the human pattern of expanded periods of growth coupled with slower trajectories of neural development is likely to have been of huge significance during hominin evolution. In addition, we discuss fossil and archaeological proxies which might allow the reconstruction of evolutionary patterns of development, suggesting that it is only post-Homo erectus and specifically among Homo heidelbergensis and Homo neanderthalensis populations that developmental patterns approximate those of modern humans, arguing for a similar – but not identical – role for socially-scaffolded learning of complex technical skills as among modern groups in these species

Multiple roles of motor imagery during action observation

Over the last 20 years, the topics of action observation (AO) and motor imagery (MI) have been largely studied in isolation from each other, despite the early integrative account by Jeannerod (1994, 2001). Recent neuroimaging studies demonstrate enhanced cortical activity when AO and MI are performed concurrently (“AO+MI”), compared to either AO or MI performed in isolation. These results indicate the potentially beneficial effects of AO+MI, and they also demonstrate that the underlying neurocognitive processes are partly shared. We separately review the evidence for MI and AO as forms of motor simulation, and present two quantitative literature analyses that indeed indicate rather little overlap between the two bodies of research. We then propose a spectrum of concurrent AO+MI states, from congruent AO+MI where the contents of AO and MI widely overlap, over coordinative AO+MI, where observed and imagined action are different but can be coordinated with each other, to cases of conflicting AO+MI. We believe that an integrative account of AO and MI is theoretically attractive, that it should generate novel experimental approaches, and that it can also stimulate a wide range of applications in sport, occupational therapy, and neurorehabilitation

Congruent and Incongruent Corticospinal Activations at the Level of Multiple Effectors

Motor resonance is defined as the subliminal activation of the motor system while observing actions performed by others. However, resonating with another person's actions is not always an appropriate response: In real life, people do not just imitate but rather respond in a suitable fashion. A growing body of neurophysiologic studies has demonstrated that motor resonance can be overridden by complementary motor responses (such as preparing a precision grip on a small object when seeing an open hand in sign of request). In this study, we investigated the relationship between congruent and incongruent corticospinal activations at the level of multiple effectors. The modulation of MEPs evoked by single-pulse TMS over the motor cortex was assessed in upper and lower limb muscles of participants observing a soccer player performing a penalty kick straight in their direction. Study results revealed a double dissociation: Seeing the soccer player kicking the ball triggered a motor resonance in the observer's lower limb, whereas the upper limb response afforded by the object was overridden. On the other hand, seeing the ball approaching the observers elicited a complementary motor activation in upper limbs while motor resonance in lower limbs disappeared. Control conditions showing lateral kicks, mimicked kicks, and a ball in penalty area were also included to test the motor coding of object affordances. Results point to a modulation of motor responses in different limbs over the course of action and in function of their relevance in different contexts. We contend that ecologically valid paradigms are nowadays needed to shed light on the motor system functioning in complex forms of interaction