Simulating and predicting others’ actions

Journal of Neuroscience, 2014

A frontoparietal action-observation network (AON) has been proposed to support understanding others' actions and goals. We show that the AON "ticks together" in human subjects who are sharing a third person's feelings. During functional magnetic resonance imaging, 20 volunteers watched movies depicting boxing matches passively or while simulating a prespecified boxer's feelings. Instantaneous intersubject phase synchronization (ISPS) was computed to derive multisubject voxelwise similarity of hemodynamic activity and inter-area functional connectivity. During passive viewing, subjects' brain activity was synchronized in sensory projection and posterior temporal cortices. Simulation induced widespread increase of ISPS in the AON (premotor, posterior parietal, and superior temporal cortices), primary and secondary somatosensory cortices, and the dorsal attention circuits (frontal eye fields, intraparietal sulcus). Moreover, interconnectivity of these regions strengthened during simulation. We propose that sharing a third person's feelings synchronizes the observer's own brain mechanisms supporting sensations and motor planning, thereby likely promoting mutual understanding.

Social Neuroscience, 2019

The mirror neuron system (MNS) becomes active during action execution and action observation, which is presumably reflected by reductions in mu (8-13 Hz) activity in the electroencephalogram over the sensorimotor cortex. The function of the MNS is still fiercely debated. The current study aimed to investigate a role of the MNS in anticipating others' actions by examining whether the MNS was activated-indexed by mu power suppressionprior to the onset of observed actions when the onset and type of action could be predicted on the basis of environmental cues. Young adults performed and observed cued grasping and placing actions in a card game in a real-life setting, while the predictability of the observed actions was manipulated using rules. Significant mu suppression, relative to within-trial baseline activity, was found both prior to and during executed actions, but also during action observation, and, crucially, prior to observed actions provided they were predictable. No anticipatory mu reductions were found prior to unpredictable observed actions. These results suggest top-down modulation of MNS activity by conceptual knowledge. This is the first study to demonstrate mu suppression prior to action onsetpossibly reflecting MNS anticipatory activity-by explicitly manipulating predictability.

Topics in Cognitive Science, 2009

Drawing on recent findings in the cognitive and neurosciences, this article discusses how people manage to predict each other's actions, which is fundamental for joint action. We explore how a common coding of perceived and performed actions may allow actors to predict the what, when, and where of others' actions. The ''what'' aspect refers to predictions about the kind of action the other will perform and to the intention that drives the action. The ''when'' aspect is critical for all joint actions requiring close temporal coordination. The ''where'' aspect is important for the online coordination of actions because actors need to effectively distribute a common space. We argue that although common coding of perceived and performed actions alone is not sufficient to enable one to engage in joint action, it provides a representational platform for integrating the actions of self and other. The final part of the paper considers links between lower-level processes like action simulation and higher-level processes like verbal communication and mental state attribution that have previously been at the focus of joint action research.

New Ideas in Psychology, 2013

Although the idea of action simulation is nowadays popular in cognitive science, neuroscience and robotics, many aspects of the simulative processes remain unclear from empirical, computational, and neural perspectives. In the first part of the article, we provide a critical review and assessment of action simulation theories advanced so far in the wider literature of embodied and motor cognition. We focus our analysis on twelve key questions, and discuss them in the context of human and (occasionally) primate studies. In the second part of the article, we describe an integrative neuro-computational account of action simulation, which links the neural substrate (as revealed in neuroimaging studies of action simulation) to the components of a computational architecture that includes internal modeling, action monitoring and inhibition mechanisms.

Our social skills are critically determined by our ability to understand and appropriately respond to actions performed by others. However despite its obvious importance, the mechanisms enabling action understanding in humans have remained largely unclear. A popular but controversial belief is that parts of the motor system contribute to our ability to understand observed actions. Here, using a novel behavioral paradigm, we investigated this belief by examining a causal relation between action production, and a component of action understanding - outcome prediction, the ability of a person to predict the outcome of observed actions. We asked dart experts to watch novice dart throwers and predict the outcome of their throws. We modulated the feedbacks provided to them, caused a specific improvement in the expert’s ability to predict watched actions while controlling the other experimental factors, and exhibited that a change (improvement) in their outcome prediction ability results in a progressive and proportional deterioration in the expert’s own darts performance. This causal relationship supports involvement of the motor system in outcome prediction by humans of actions observed in others.

During the lengthy and complex process of human evolution our ancestors had to adapt to extremely testing situations in which survival depended on making rapid choices that subjected muscles and the body as a whole to extreme tension. In order to seize a prey traveling at speeds that could reach 36 km per hour Homo sapiens had just thousandths of a second in which to anticipate the right moment and position himself before the prey arrived. He also had to prepare the appropriate gesture, tensing his muscles and overcoming the resistance determined by body weight. While we are no longer faced with an environment that is anything so threatening, our brain continues to use these mechanisms day in day out to save time and energy, enabling us to avoid situations of danger, sense in advance the intentions of an interlocutor, and more besides. In this article we set out to show that our brain is not only a reactive mechanism, capable of reacting quickly to the stimuli that arrive from the external environment, but is above all a pro-active mechanism that allows us to make hypotheses, anticipate the consequences of actions, and formulate expectations: in short, to wrong foot an adversary.

The Journal of Neuroscience, 2020

2012

Assigning meaning to the actions of other subjects is an essential aspect of everyday social communication. A major contribution in understanding the brain mechanism supporting recognition of others’ actions was the discovery of ‘mirror neurons’, which are activated both when a monkey grasps an object and when he observes other subjects executing the same grasps. However, our recent findings indicate that the system responsible for understanding the actions of other subjects encompasses the entire brain circuitry that supports action execution, rather than just the part of cortex containing ‘mirror neurons’. These findings contradict the widely held notion 99 How Do we unDerstanD tHe actions of otHers? that ‘mirror neurons’ alone code the meaning of observed actions performed by other subjects, and instead support the theory that we decode others’ actions by activating our own action system, i.e. by mentally simulating the observed acts.

Brain Research, 2006

A large number of cognitive neuroscience studies point to the similarities in the neural circuits activated during the generation, imagination, as well as observation of one's own and other's behavior. Such findings support the shared representations account of social cognition, which is suggested to provide the basic mechanism for social interaction. Mental simulation may also be a representational tool to understand the self and others. However, successfully navigating these shared representationsboth within oneself and between individualsconstitutes an essential functional property of any autonomous agent. It will be argued that self-awareness and agency, mediated by the temporoparietal (TPJ) area and the prefrontal cortex, are critical aspects of the social mind. Thus, differences as well as similarities between self and other representations at the neural level may be related to the degrees of self-awareness and agency. Overall, these data support the view that social cognition draws on both domain-general mechanisms and domain-specific embodied representations.