Watch and Learn: The Cognitive Neuroscience of Learning from Others’ Actions
Authors: Richard Ramsey, David M. Kaplan, Emily S. Cross
Journal: Trends in Neurosciences (2021)

Understanding how the human brain translates visual information into skilled motor performance has been assisted and constrained by the discovery of mirror neurons.Emerging evidence highlights how observational motor learning involves a far more diffuse network of brain regions and cognitive processes, which are shaped by the context and complexity of the motor task to be learned.A greater emphasis on combining functional decomposition and functional integration approaches should facilitate paradigms and discoveries that move us closer toward understanding how we learn from watching others in complex, real-world scenarios. The mirror neuron system has dominated understanding of observational learning from a cognitive neuroscience perspective. Our review highlights the value of observational learning frameworks that integrate a more diverse and distributed set of cognitive and brain systems, including those implicated in sensorimotor transformations, as well as in more general processes such as executive control, reward, and social cognition. We argue that understanding how observational learning occurs in the real world will require neuroscientific frameworks that consider how visuomotor processes interface with more general aspects of cognition, as well as how learning context and action complexity shape mechanisms supporting learning from watching others. The mirror neuron system has dominated understanding of observational learning from a cognitive neuroscience perspective. Our review highlights the value of observational learning frameworks that integrate a more diverse and distributed set of cognitive and brain systems, including those implicated in sensorimotor transformations, as well as in more general processes such as executive control, reward, and social cognition. We argue that understanding how observational learning occurs in the real world will require neuroscientific frameworks that consider how visuomotor processes interface with more general aspects of cognition, as well as how learning context and action complexity shape mechanisms supporting learning from watching others. Whether learning to dance Gangnam Style, open a bottle of champagne, or tie shoelaces, humans learn a great deal by simply watching others [1.Hodges N.J. et al.What is modelled during observational learning?.J. Sports Sci. 2007; 25: 531-545Crossref PubMed Scopus (95) Google Scholar,2.Vogt S. Thomaschke R. From visuo-motor interactions to imitation learning: behavioural and brain imaging studies.J. Sports Sci. 2007; 25: 497-517Crossref PubMed Scopus (106) Google Scholar]. Learning by observation can have many benefits over physical practice without observation. This is especially true in dangerous or novel environments where poor initial performance can be costly, such as learning to drop in on a skateboard ramp without first watching someone else do it successfully. Equally, learning by watching others is beneficial in social situations where active participation is not possible, such as watching your supervisor give critical feedback to a colleague. As such, observational learning has been of considerable interest to experts from a variety of disciplines, including social and developmental psychology, sport and exercise science, comparative biology and robotics, where researchers are examining how we learn from watching others across a range of behaviors, from simple motor movements to complex social interactions [1.Hodges N.J. et al.What is modelled during observational learning?.J. Sports Sci. 2007; 25: 531-545Crossref PubMed Scopus (95) Google Scholar,3.Bandura A. Walters R.H. Social Learning Theory.Vol. 1. Prentice-Hall Englewood Cliffs, 1977Google Scholar, 4.Csibra G. Gergely G. Natural pedagogy.Trends Cogn. Sci. 2009; 13: 148-153Abstract Full Text Full Text PDF PubMed Scopus (842) Google Scholar, 5.Carcea I. Froemke R.C. Biological mechanisms for observational learning.Curr. Opin. Neurobiol. 2019; 54: 178-185Crossref PubMed Scopus (12) Google Scholar]. Contemporary empirical study into how we learn from watching others originated, to a large extent, in the social learning (see Glossary) research of Albert Bandura and colleagues starting in the 1960s [3.Bandura A. Walters R.H. Social Learning Theory.Vol. 1. Prentice-Hall Englewood Cliffs, 1977Google Scholar,6.Bandura A. Jeffrey R.W. Role of symbolic coding and rehearsal processes in observational learning.J. Pers. Soc. Psychol. 1973; 26: 122Crossref Scopus (0) Google Scholar, 7.Carroll W.R. Bandura A. The role of visual monitoring in observational learning of action patterns: making the unobservable observable.J. Mot. Behav. 1982; 14: 153-167Crossref PubMed Google Scholar, 8.Carroll W.R. Bandura A. Representational guidance of action production in observational learning: a causal analysis.J. Mot. Behav. 1990; 22: 85-97Crossref PubMed Google Scholar]. Much of this early work focused on the role of an observer’s motivation to learn and social factors relevant to the model. Over the past several decades, however, empirical interest in examining observational learning has come increasingly from the action domain, with considerable attention from cognitive neuroscientists who have begun to explore and characterize the systems within the human brain that translate visual signals into motor output [2.Vogt S. Thomaschke R. From visuo-motor interactions to imitation learning: behavioural and brain imaging studies.J. Sports Sci. 2007; 25: 497-517Crossref PubMed Scopus (106) Google Scholar,9.Cross E.S. et al.Sensitivity of the action observation network to physical and observational learning.Cerebr. Cortex. 2009; 19: 315-326Crossref PubMed Scopus (290) Google Scholar, 10.Cross E.S. et al.Learning to tie the knot: the acquisition of functional object representations by physical and observational experience.PLoS One. 2017; 12e0185044Crossref PubMed Scopus (8) Google Scholar, 11.Sakreida K. et al.Cognitive control structures in the imitation learning of spatial sequences and rhythms – an fMRI study.Cereb. Cortex. 2018; 28: 907-923Crossref PubMed Scopus (10) Google Scholar, 12.Hodges N.J. Observations on action-observation research: an autobiographical retrospective across the past two decades.Kinesiol. Rev. 2017; 6: 240-260Crossref Scopus (6) Google Scholar]. While tremendous progress has been made in identifying the neural correlates supporting observational learning of others’ actions, our understanding of how we learn from watching the actions of others remains in its infancy. The foundational structure of relevant cognitive and brain systems remains largely unknown and many key questions still need to be addressed. By synthesizing initial findings from several relevant subdisciplines of human neuroscience and placing them within a wider context of observational learning across species and agents, we aim to provide an overview of the progress that has been made towards understanding brain-based mechanisms that support observational learning. We also outline important next steps that, if taken, could generate a more complete understanding of this ubiquitous and vital capacity. Much like human neuroscience research in general, observational learning research within cognitive neuroscience has tended to focus on understanding the role of a restricted set of brain areas, such as the human mirror neuron system. This focus has undoubtedly contributed to our knowledge about how we learn from watching others, but it has also come at the expense of understanding and appreciating the roles played by a wider set of systems, as well as how such systems interact. These additional systems include the motor system more generally, as well as regions associated with semantic processing, attention, and memory. What is currently lacking, therefore, are frameworks describing how the brain enables information to be incorporated across distributed neural networks, some of which may be particularly relevant for action learning and others that may support a host of more general cognitive processes. Human social life is simply too complex to understand by focusing exclusively on the operation of subsystems in isolation. For example, if a clear understanding of motor development in children or expertise in dancers and athletes is to be developed, it is vital to study more than a restricted set of motor skills suitable for laboratory study (such as key pressing or moving a manipulandum), where the focus is on a subset of component systems. Likewise, if socially harmonious robotic agents that learn from and adapt to human actions are to be developed, this will require a fuller understanding not only of how skills are acquired by observation but also how they fit with other states and processes such as motivation, goals, and intentions. Without incorporating these perspectives, one is likely to fall short of a holistic understanding of the processes and systems that support observational learning in the human brain, how these develop and change across the lifespan, and how these might be modeled in artificial agents. Given the varieties of observational learning that have been studied to date (Box 1), it is important to establish the scope of this review. We focus on a specific type of observational learning – namely observational motor learning, where action observation leads to an enduring refinement to motor performance. We have organized the review into three main parts. First, owing to its dominance, we review research into the role of the human mirror neuron system in observational learning. Next, we review evidence implicating motor processes extending beyond the mirror system in observational learning. We outline how research on sequence learning and motor adaptation in particular informs our understanding of the neural substrates underlying observational learning. Finally, we review evidence highlighting the roles played by non-motor systems in observational learning, such as those associated with cognitive control and reward. We also detail how systems or frameworks that might seem less relevant to understanding observational learning, such as semantic and memory systems, as well as 'real-life' neuroscience approaches, also hold considerable potential for making progress in this endeavor.Box 1Varieties of Observational LearningMultiple types of observational learning exist and, like many subdomains of cognitive neuroscience, the use of vague terminology fuels confusion and hinders progress [107.Lenartowicz A. et al.Towards an ontology of cognitive control.Top. Cogn. Sci. 2010; 2: 678-692Crossref PubMed Scopus (0) Google Scholar,108.Poldrack R. et al.The cognitive atlas: toward a knowledge foundation for cognitive neuroscience.Front. Neuroinformatics. 2011; 5Crossref PubMed Scopus (135) Google Scholar]. We define here the specific type of observational learning that we focus on to distinguish it from related, but distinct, interests. Our aim is to provide operational definitions and distinctions that are important for this article’s discussions, and we recognize that strict definitions of broad consensus may be beyond reach, given the complexity of the topic.At its broadest, observational learning can be conceived as any instance where one observes someone and learns something new or modifies a previously learned skill or behavior. We define learning here as an enduring change in the way that an organism responds, based on its experiences [109.Kimble G.A. Hilgard and Marquis' "Conditioning and Learning". Appleton-Century-Crofts, 1961Google Scholar]. In this review we focus on a subtype of observational learning that has two necessary requirements: (i) an action must be observed, and (ii) an enduring change to motor performance must occur. Several implications follow from this operational definition. First, one can study the cognitive and brain mechanisms associated with action observation without studying learning [17.Caspers S. et al.ALE meta-analysis of action observation and imitation in the human brain.NeuroImage. 2010; 50: 1148-1167Crossref PubMed Scopus (762) Google Scholar, 18.Molenberghs P. et al.Brain regions with mirror properties: a meta-analysis of 125 human fMRI studies.Neurosci. Biobehav. Rev. 2012; 36: 341-349Crossref PubMed Scopus (476) Google Scholar, 19.Hardwick R.M. et al.Neural correlates of action: comparing meta-analyses of imagery, observation, and execution.Neurosci. Biobehav. Rev. 2018; 94: 31-44Crossref PubMed Scopus (138) Google Scholar,26.Cross E.S. et al.Building a motor simulation de novo: observation of dance by dancers.Neuroimage. 2006; 31: 1257-1267Crossref PubMed Scopus (529) Google Scholar,110.Rizzolatti G. Sinigaglia C. The mirror mechanism: a basic principle of brain function.Nat. Rev. Neurosci. 2016; 17: 757-765Crossref PubMed Scopus (158) Google Scholar,111.Cross E.S. et al.Robotic movement preferentially engages the action observation network.Hum. Brain Mapp. 2012; 33: 2238-2254Crossref PubMed Scopus (99) Google Scholar]. Indeed, one's ability to perform a triple Axel jump may remain unchanged after watching figure skating in the Olympic Games. Second, learning from observing actions is not the same as imitation, although they may co-occur and do rely on partly shared cognitive and brain processes. To qualify as imitation, one must copy someone, whether intentionally or not [112.Arnold A.J. Winkielman P. The mimicry among us: intra-and inter-personal mechanisms of spontaneous mimicry.J. Nonverbal Behav. 2020; 44: 195-212Crossref Scopus (9) Google Scholar, 113.Heyes C. Automatic imitation.Psychol. Bull. 2011; 137: 463-483Crossref PubMed Scopus (308) Google Scholar, 114.Iacoboni M. Imitation, empathy, and mirror neurons.Annu. Rev. Psychol. 2009; 60: 653-670Crossref PubMed Scopus (820) Google Scholar]. By contrast, one need not immediately imitate someone to learn by observation. For example, one could watch Beyoncé dancing in a music video (without copying her actions at the time) and then be better at reproducing those dance moves the following weekend when dancing in a club. Third, we can distinguish skill learning through observation of other people’s actions from other forms of learning based on watching other people behave more generally, which are collectively referred to as social learning [4.Csibra G. Gergely G. Natural pedagogy.Trends Cogn. Sci. 2009; 13: 148-153Abstract Full Text Full Text PDF PubMed Scopus (842) Google Scholar,115.Gariépy J.-F. et al.Social learning in humans and other animals.Front. Neurosci. 2014; 8: 58PubMed Google Scholar,116.Busching R. Krahé B. With a little help from their peers: the impact of classmates on adolescents’ development of prosocial behavior.J. Youth Adolesc. 2020; : 1-15Google Scholar]. Although observational motor learning is one type of social learning, social learning also encompasses a much broader range of behaviors, some of which are extremely complex, such as how to resist peer pressure to partake in risky behaviors, respond to criticism, or interact appropriately with people from different cultures. Fourth, demonstration that particular cognitive and brain processes support observational learning does not imply that they are uniquely tied to observational learning per se. For example, given the links between motor imagery and action observation [117.Cumming J. Eaves D.L. The nature, measurement, and development of imagery ability.Imagin. Cogn. Pers. 2018; 37: 375-393Crossref Google Scholar, 118.Eaves D.L. et al.Motor imagery during action observation: a brief review of evidence, theory and future research opportunities.Front. Neurosci. 2016; 10: 514Crossref PubMed Scopus (100) Google Scholar, 119.Vogt S. et al.Multiple roles of motor imagery during action observation.Front. Hum. Neurosci. 2013; 7: 807Crossref PubMed Scopus (0) Google Scholar], it is possible that processes common to motor imagery and action observation are involved to some extent when learning by watching others. Multiple types of observational learning exist and, like many subdomains of cognitive neuroscience, the use of vague terminology fuels confusion and hinders progress [107.Lenartowicz A. et al.Towards an ontology of cognitive control.Top. Cogn. Sci. 2010; 2: 678-692Crossref PubMed Scopus (0) Google Scholar,108.Poldrack R. et al.The cognitive atlas: toward a knowledge foundation for cognitive neuroscience.Front. Neuroinformatics. 2011; 5Crossref PubMed Scopus (135) Google Scholar]. We define here the specific type of observational learning that we focus on to distinguish it from related, but distinct, interests. Our aim is to provide operational definitions and distinctions that are important for this article’s discussions, and we recognize that strict definitions of broad consensus may be beyond reach, given the complexity of the topic. At its broadest, observational learning can be conceived as any instance where one observes someone and learns something new or modifies a previously learned skill or behavior. We define learning here as an enduring change in the way that an organism responds, based on its experiences [109.Kimble G.A. Hilgard and Marquis' "Conditioning and Learning". Appleton-Century-Crofts, 1961Google Scholar]. In this review we focus on a subtype of observational learning that has two necessary requirements: (i) an action must be observed, and (ii) an enduring change to motor performance must occur. Several implications follow from this operational definition. First, one can study the cognitive and brain mechanisms associated with action observation without studying learning [17.Caspers S. et al.ALE meta-analysis of action observation and imitation in the human brain.NeuroImage. 2010; 50: 1148-1167Crossref PubMed Scopus (762) Google Scholar, 18.Molenberghs P. et al.Brain regions with mirror properties: a meta-analysis of 125 human fMRI studies.Neurosci. Biobehav. Rev. 2012; 36: 341-349Crossref PubMed Scopus (476) Google Scholar, 19.Hardwick R.M. et al.Neural correlates of action: comparing meta-analyses of imagery, observation, and execution.Neurosci. Biobehav. Rev. 2018; 94: 31-44Crossref PubMed Scopus (138) Google Scholar,26.Cross E.S. et al.Building a motor simulation de novo: observation of dance by dancers.Neuroimage. 2006; 31: 1257-1267Crossref PubMed Scopus (529) Google Scholar,110.Rizzolatti G. Sinigaglia C. The mirror mechanism: a basic principle of brain function.Nat. Rev. Neurosci. 2016; 17: 757-765Crossref PubMed Scopus (158) Google Scholar,111.Cross E.S. et al.Robotic movement preferentially engages the action observation network.Hum. Brain Mapp. 2012; 33: 2238-2254Crossref PubMed Scopus (99) Google Scholar]. Indeed, one's ability to perform a triple Axel jump may remain unchanged after watching figure skating in the Olympic Games. Second, learning from observing actions is not the same as imitation, although they may co-occur and do rely on partly shared cognitive and brain processes. To qualify as imitation, one must copy someone, whether intentionally or not [112.Arnold A.J. Winkielman P. The mimicry among us: intra-and inter-personal mechanisms of spontaneous mimicry.J. Nonverbal Behav. 2020; 44: 195-212Crossref Scopus (9) Google Scholar, 113.Heyes C. Automatic imitation.Psychol. Bull. 2011; 137: 463-483Crossref PubMed Scopus (308) Google Scholar, 114.Iacoboni M. Imitation, empathy, and mirror neurons.Annu. Rev. Psychol. 2009; 60: 653-670Crossref PubMed Scopus (820) Google Scholar]. By contrast, one need not immediately imitate someone to learn by observation. For example, one could watch Beyoncé dancing in a music video (without copying her actions at the time) and then be better at reproducing those dance moves the following weekend when dancing in a club. Third, we can distinguish skill learning through observation of other people’s actions from other forms of learning based on watching other people behave more generally, which are collectively referred to as social learning [4.Csibra G. Gergely G. Natural pedagogy.Trends Cogn. Sci. 2009; 13: 148-153Abstract Full Text Full Text PDF PubMed Scopus (842) Google Scholar,115.Gariépy J.-F. et al.Social learning in humans and other animals.Front. Neurosci. 2014; 8: 58PubMed Google Scholar,116.Busching R. Krahé B. With a little help from their peers: the impact of classmates on adolescents’ development of prosocial behavior.J. Youth Adolesc. 2020; : 1-15Google Scholar]. Although observational motor learning is one type of social learning, social learning also encompasses a much broader range of behaviors, some of which are extremely complex, such as how to resist peer pressure to partake in risky behaviors, respond to criticism, or interact appropriately with people from different cultures. Fourth, demonstration that particular cognitive and brain processes support observational learning does not imply that they are uniquely tied to observational learning per se. For example, given the links between motor imagery and action observation [117.Cumming J. Eaves D.L. The nature, measurement, and development of imagery ability.Imagin. Cogn. Pers. 2018; 37: 375-393Crossref Google Scholar, 118.Eaves D.L. et al.Motor imagery during action observation: a brief review of evidence, theory and future research opportunities.Front. Neurosci. 2016; 10: 514Crossref PubMed Scopus (100) Google Scholar, 119.Vogt S. et al.Multiple roles of motor imagery during action observation.Front. Hum. Neurosci. 2013; 7: 807Crossref PubMed Scopus (0) Google Scholar], it is possible that processes common to motor imagery and action observation are involved to some extent when learning by watching others. We conclude by articulating what is known and what remains to be discovered regarding the cognitive neuroscience of learning from watching others. If the ultimate goal is to understand observational learning as it occurs in daily life, there is a need to consider a distributed and diverse set of interacting neurocognitive systems both within and beyond the human mirror neuron system. It is also imperative to combine evidence gathered from controlled laboratory conditions with work that puts observational learning to the test in complex and rich real-world contexts to better understand how to support and bolster this vital skill. Cognitive neuroscientific investigations into observational learning have focused extensively on the role played by the human mirror neuron system (Box 2). Since the discovery of mirror neurons within premotor and, later, inferior parietal cortices of the non-human primate brain [13.Gallese V. et al.Action recognition in the premotor cortex.Brain. 1996; 119: 593-609Crossref PubMed Google Scholar, 14.Rizzolatti G. et al.Premotor cortex and the recognition of motor actions.Brain Res. Cogn. Brain Res. 1996; 3: 131-141Crossref PubMed Scopus (2980) Google Scholar, 15.Fogassi L. et al.Parietal lobe: from action organization to intention understanding.Science. 2005; 308: 662-667Crossref PubMed Scopus (1343) Google Scholar], researchers have sought to determine whether similar neural processes exist within the human brain. To do so, researchers have used a variety of noninvasive neuroimaging and neurostimulation measures to probe links between action and perception [16.Grèzes J. Decety J. 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Furthermore, research examining learning guitar chords [27.Buccino G. et al.Neural circuits underlying imitation learning of hand actions: an event-related fMRI study.Neuron. 2004; 42: 323-334Abstract Full Text Full Text PDF PubMed Scopus (568) Google Scholar, 28.Higuchi S. et al.Imitation and observational learning of hand actions: prefrontal involvement and connectivity.Neuroimage. 2012; 59: 1668-1683Crossref PubMed Scopus (0) Google Scholar, 29.Gardner T. et al.Using guitar learning to probe the action observation network's response to visuomotor familiarity.NeuroImage. 2017; 156: 174-189Crossref PubMed Scopus (16) Google Scholar], dance movements [9.Cross E.S. et al.Sensitivity of the action observation network to physical and observational learning.Cerebr. Cortex. 2009; 19: 315-326Crossref PubMed Scopus (290) Google Scholar,30.Kirsch L.P. Cross E.S. Additive routes to action learning: layering experience shapes engagement of the action observation network.Cereb. 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Brain Res. 2014; 261: 328-335Crossref PubMed Scopus (26) Google Scholar, 33.Rüther N.N. et al.Observed manipulation enhances left fronto-parietal activations in the processing of unfamiliar tools.PLoS One. 2014; 9e99401Crossref PubMed Scopus (11) Google Scholar] reported converging evidence that frontoparietal brain regions are modulated when observation of others’ actions resulted in subsequent learning. This evidence has led to a general understanding within cognitive neuroscience that action learning by observation relies, at least in part, on functions performed by the mirror neuron system.Box 2Charting the Core and Extended Mirror Neuron SystemsIn the human mirror neuron system literature, most studies relate to activity within inferior parietal and ventral premotor cortices in the human brain [120.Rizzolatti G. Craighero L. The mirror-neuron system.Annu. Rev. Neurosci. 2004; 27: 169-192Crossref PubMed Scopus (4953) Google Scholar]. These cortices represent the human homologs of rhesus macaque monkey brain regions where mirror neurons were first discovered [13.Gallese V. et al.Action recognition in the premotor cortex.Brain. 1996; 119: 593-609Crossref PubMed Google Scholar,121.di Pellegrino G. et al.Understanding motor events: a neurophysiological study.Exp. Brain Res. 1992; 91: 176-180Crossref PubMed Scopus (2064) Google Scholar]. Neurons within macaque ventral premotor and inferior parietal cortices were found to respond to the observation and execution of hand and mouth actions, and early neuroimaging work performed with human participants also found spatial overlap within ventral premotor and inferior parietal cortices when people observed or executed movements [16.Grèzes J. Decety J. Functional anatomy of execution, mental simulation, observation, and verb generation of actions: a meta-analysis.Hum. 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