I.Introduction

The training dancers gain throughout their career is highly specific, uniquely shaping the way their brains process information related to movements beyond mere action execution[1].Not only does dance training change the way dancers execute movement,recent research has illustrated that dance training alters the way dancers see movement[1].This phenomenon has generated a body of research that points to professional dancers for insights about the influence of motor expertise on action observation, execution,and understanding.While findings have emphatically advanced the conversation on how the study of dance contributes to advancements in our knowledge of learning and human cognition, there is currently little discourse on how those f ndings can be applied back to dance to further enhance training.

李打油嘴都笑歪了。真的歪，跟我父亲一样，平时看不出，浅笑也看不出，只有笑得特别开心时，笑过后要把笑容收回去的那一瞬间，才会发现，他俩嘴都有点歪。共祖宗嘛，也许家族遗传。估计我也是。可我好像没遇到什么特别开心的事。

In addition to the common actions shared by a lar ge portion of the human population, such as walking and grasping, a dancer’s motor repertoire is composed of specialised and intransitive actions that do not require a physical object or tar get to drive the movement or achieve a goal, such as pirouetting[1].One unit of this motor repertoire is termed a motor representation[1].Wilmerding and Krasnow maintain that the aim of teaching dance is to train these motor representations[2].The present paper will seek to explore the central f ndings in recent action-observation network (AON) research in relation to motor learning theory and praxis in order to highlight the role of observation as an important practice in training motor representations speci f c to dance.It will explore the chief question: How can our knowledge about AON be reinforced pedagogically to promote ef fective observational practices for dancers endeavouring to learn,refine, and maintain motor representations in dance class and while injured?

II.The Action-Observation Network

Dance exists for a multitude of reasons, from cultural integration to commercial entertainment;however, it can also be ar gued that dance, at its essence, exists to be observed.There is a transaction that occurs between performer and spectator, and the currency of this transaction is movement.One executes the movement and the other perceives it, thus introducing the concept that action and perception are represented within the same framework.The first forays into an action-perception system occurred in the 1990s using single-unit recording on the ventral premotor cortices of monkeys[3].The outcome of these recordings demonstrated that neurons in the ventral premotor cortex discharged when the monkey made specific movements and when the monkey observed the experimenter making the same movements[3].Thus,a mirror-like relationship was discerned between the visual action the neurons responded to and the motor response they coded for[3].The first evidence of these“mirror” neurons in humans came from studies using transcranial magnetic stimulation[1,4,5].The localization of such neurons in the premotor, supplementary motor,and parietal cortices nodded to the importance of the motor system for the observation of actions[1,6].The premotor cortex in particular encodes detailed action plans for complex movements, such as dance sequences that require information relating to its visual, auditory,temporal, spatial, and social features, its kinematics, and its composition.Research into the mirror neuron system suggests that action observation activates these action plans[4].

每隔一段时间，团队会在如何才能更有效地工作方面进行反省，然后相应地对自己的行为进行调整。为了保持团队的敏捷性，必须随环境一起变化。

After multiple studies were conducted on primates and humans using a variety of techniques, from motion capture to brain imaging, researchers corroborated the idea that when watching someone perform an action,an individual’s brain will simulate the performance of that action, and the notion of an AON emerged[4,6,7].The AON is a network that broadly encompasses all of the neural regions involved in visual analysis and motor sequencing, effectually unifying the processes involved in action observation and action execution[5,8].Under this union, it is conceivable that an observed action is understood from the inside as a motor possibility and not just from the outside as a visual experience[5].Moreover, evidence suggests that the interactions within the AON are not solely for the purpose of immediate imitation but are sensitive to the lasting ef fects of physical and perceptual experience as well[8].This provides the bedrock for higher mental functions, such as observational learning[4].

Kirsh contends that marking is also a method of anchoring a projection to a tar get—meaning that by having an external representation to “lean on” a dancer can better conceptualize a movement idea[12].This comes from the notion of a distributed vehicle of thought, for which there is an inner part and an outer part that work in tandem to support a clearer thought[12].For Kirsh, the inner part is the mental structure and the outer part is the marked, physical structure[12].While this makes sense in the instance of the dancer rehearsing a piece of choreography, there is still question about the application of marking in a dance class setting.If,according to Hutchinson, the physical form does not need to be self-created[12], could not the external part on which the mental structure is projected be an observed demonstration?

有些朋友或者学生，常常会觉得我很容易满足，奇怪我为什么会在很多事情里都能行到较好的那一面。我也不知道为什么，我只是觉得，一切的事物都是互为因果的，尤其是爱情，你若善待它，它一定善待你。

In a study that used functional neuroimaging to characterize the neural underpinnings of observational learning with and without the added bene f t of physical practice, Cross et al.found that observational learning alone can lead to robust response changes within the AON[8].Findings from this study also indicated a high correspondence between neural regions activated by passive observation and physical practice[8].These active regions—the dorsolateral prefrontal cortex and the cerebellum—work together to assist in the procedural learning of motor sequences and the flexible recall of previously learned sequences, which is a critical facet of observational learning[8].Taken together, these f ndings suggest that physical and observational learning share common neural substrates[8].Therefore, action observation may be as ef fective as physical practice in facilitating dance training[8].

Perhaps the most interesting aspect of Cross et al.’s research was that participants were not instructed to observe movement with the intent to learn or perform it[8].Hence, it would seem that observational learning occurs even when attention is not focused.This begs the question: If learning can be facilitated passively,what happens when observation is enacted with direct attention?

III.Observation in Dance Class

Marking for others is only reliable when used to convey information about space, position, and structural form—information that is grossly visually processed[12].In watching a mark, observers miss out on certain attributes, such as intensity, motion dynamics, and f ne detail that are important to learning motor representations.Therefore, if a teacher’s aim in marking is to prepare the dancer motorically, why mark? Moreover, marking is so idiosyncratic, especially in less codified dance genres, such as contemporary,that when one marks, observers may not perceive the full-out movement in the marked version unless the observers have been primed to the full-out movement previously[12].Consequently, marking is rendered ineffective when learning novel movement phrases.Dancers rarely mark a phrase they do not know; neither should teachers when demonstrating new material.Indeed, Magill stresses that when demonstrating key features of a movement skill, the demonstrator should be certain that all observers can clearly see the features[11].This suggests that dance teachers, if able,should demonstrate movement phrases full out.If not able, teachers should have a student demonstrate the phrase full out and provide feedback as necessary.Teachers should strive to mark only in circumstances when motor schemata have been stabilised through extensive practice (for example, in a professional-level ballet class).

Learning is best facilitated when an individual’s attention is focused on one task[11].One research study demonstrated that participants who engaged in an isolated movement-related activity during the time interval between the demonstration of a movement sequence and the attempt to reproduce that movement sequence recalled fewer movements than those who did not engage in the isolated movement-related activity[11].This decrease in recall suggests that a diverted attentional focus affects memory consolidation.In dance classes across all genres, dancers are seen“marking” movement sequences—or dancing the phrases in a less than complete manner—as they learn them[12].Ballet dancers might use their arms to mark what their feet will do during a barre exercise,or contemporary dancers might mark floor-work,walking up-right through the space while the teacher demonstrates the sequence “full-out” on the floor.Does this type of marking divert dancers’ attention and impact their capacity to learn?

Marking for oneself can be seen as advantageous,particularly when a dancer is rehearsing a piece of choreography and wants to reserve ener gy but also desires to review sequence and examine spatiality.But what about marking for oneself in a dance class setting? Marking enables a dancer to physically simulate a process necessary to generate a conception of target motor representations that are more vivid and complete than mental images alone[12].Kirsh maintains that marking primes the neural systems involved in creating tar get motor representations, thereby activating cortical areas responsible for the full-out versions[12].Given that marking implicates motor preparation, spatial planning, and proprioceptive monitoring, it is proposed that even more areas of the cortex are activated in marking than in mental rehearsal[12].However, because the AON encompasses all of the neural regions accountable for perceptual processing, it can be ar gued that observing serves the same purpose as marking.And if motor programmes are indeed activated the same way in marking as they are in observing, why mark altogether?

When observation is considered in the context of dance, it has clear motoric objectives.Whether it is to perfect one’s own repertoire by watching the teacher or to synchronize with others in a group, dancers learn by reproducing the movements they observe[9,10].Therefore,it is reasonable to assume that motor stimulation through observation, as evidenced by the workings of the AON,has important applications for dancers learning, re f ning,and maintaining skills in the dance studio and while injured[4].

【解读】 高通量测序属于分子遗传检测手段，开展临床应用应当遵循分子遗传项目的通用标准和原则。比如，实验室应该满足临床PCR实验室管理规范、技术人员应当具备PCR上岗证、遗传咨询人员应当在具备产前诊断资格的机构开展咨询并具备遗传咨询资质。实验室对基因突变的分析流程应当具备GATK分析能力、ANNOVA注释能力，突变分析须遵照ACMG指南。

步骤2 分别随机选择3种运行状态下部分双谱时频图组成训练样本集XTrain(i)(i=1,2,3)(i代表滚动轴承的3种运行状态),对训练样本集XTrain(i)(i=1,2,3)的子集Vi(i=1,2,3)分别进行SNMF,得到3种运行状态下的标准图像集Wi(i=1,2,3).

In a study conducted by Calvo-Merino et al.,dancers who viewed familiar movement material showed strong activation of brain areas that are consistent in episodic memory and contribute to recall from the longterm storage of allocentric information—these areas are the cingulate, retrosplenial, and parahippocampal regions[4].It is postulated that observation without a secondary attentional task, such as marking, could activate these more speci f c brain regions and reinforce memory consolidation.Although contrary to Kirsh’s belief that the addition of marking aids memory consolidation by reducing a dancer’s cognitive load,observing without marking supports the paradigm of augmented rest within a dance class[12].Augmented rest(or distributed practice) is not only beneficial in that it offers the dancer time for physical recovery, but it allows the nervous system time to process new motor patterns[11].Furthermore, observing could be superior to marking in reducing a dancer’s mental effort because there is no need for a dancer to conceptually represent the details of a movement phrase when the representation is already present.

Cross et al.states that observational learning is not def ned by the type of instruction; rather, it is def ned by the learner not performing concurrent physical practice at the time instructions are provided[8].Thus, dancers should be encouraged to completely cease activity during demonstration to observe, re f ect, and interrogate presented information.As little as 12 seconds with no interference can promote memory retention and transfer better than the immediate repetition of a movement sequence[8].And in keeping with the consideration that observational learning is a form of augmented rest, Schmidt and Lee posit that the most successful strategy when employing demonstration is interspersing demonstrated information with practice attempts—as opposed to having all demonstrated information precede physical practice—so that the dancer can be engaged in the problem-solving aspect of learning while still receiving rest between attempts[13].

In an experiment by Cross, Hamilton, and Grafton that investigated the extent to which observing and imaging actions requires prior physical experience,modern dancers were asked to either observe actions,imagine their own performing actions, or both observe and imagine actions[8].While there was an evident increase in brain activity with combined observation and imagination regardless of embodiment, the more embodied the movement was within the dancer,the stronger the brain activity was[8].This adds to the research of Calvo-Merino et al.that found that previous physical experience with an observed movement was necessary for forceful activation in the AON[4,10].Therefore, it may behove injured dancers to do everything within their physical ability to have an experience with a movement task in class.For instance, if a dancer is side-lined with a lower leg injury and the class is learning a novel movement representation, he or she should still endeavour to have a full-out experience with the upper body.In addition, Calvo-Merino et al.also revealed that there was greater premotor, parietal, and cerebellar activity in dancers who saw movements from their own motor repertoire[10].Therefore, perhaps a more inconsequential conclusion is that when observing a dance class with gender-specific movements,injured male dancers should focus on observing male movements, whereas injured female dancers should focus on observing female movements.

The present paper makes a recommendation against dancers marking for themselves in dance class,but what about dance teachers marking movement phrases for dancers? In an ef fort to direct a dancer’s attentional focus during observation, it is recommended that dance teachers make the crucial aspects of a motor representation explicit so that students actively engage in the problem-solving process[2,11].There of course remains a question of if “crucial aspects” of movement even exist when, in dance, movement itself is crucial.Yet in light of the query over marking, it can be asked: What are the most crucial aspects to demonstrate full out, and what aspects are acceptable to mark? It is agreed that in a mark, only certain aspects of a movement phrase are attended to, but whether or not these are the “crucial aspects” remains uncertain.

Attention is an important process in observational learning[11].When a person observes a model, he or she translates the perceived information into a code that forms the basis of a movement representation that is then stored in long-term memory in a process termed memory consolidation[11].There are four governing principles to memory consolidation, one of which is attention.

“长宜子孙”这四个字的年龄比我的不知大了多少，这也该是我祖父留下的东西吧。最近在家里我还读到他的遗嘱，他用空空两手造就了一份家业，到临死还周到地为儿孙安排了舒适的生活。他叮嘱后人保留着他修建的房屋和他辛苦地搜集起来的书画。但是儿孙们回答他的还是同样的字：分和卖。我很奇怪，为什么这样聪明的老人还不明白一个浅显的道理：财富并不“长宜子孙”，倘使不给他们一个生活技能，不向他们指示一条生活道路，“家”这个小圈子只能摧毁年轻心灵的发育成长，倘使不同时让他们睁起眼睛去看广大世界；财富只能毁灭崇高的理想和善良的气质，要是它只消耗在个人的利益上面。

舞者在整个职业生涯中受到的训练不仅仅塑造了其执行动作的方式，更塑造了其大脑处理与动作相关信息的方式。最近的研究表明，训练改变了舞者看待动作的方式。虽然这些研究结果有力地推进了舞蹈研究有助于知识习得和人类认知的进步这一观点，但目前鲜有针对如何将这些成果应用在舞蹈中以进一步提升训练的研究。本文旨在探讨近期与运动学习实践相关的动作观察神经网络（AON）研究中的核心成果，从而强调“观察”在舞蹈运动表现训练实践中的重要作用。

Herein lies the case for watching peers and attending to their feedback in dance class.While anecdotally, this is already a practise that is fostered by dance teachers, it remains a motor learning principle that merits emphasis.Within a class structure, dancing in groups is believed to help learners gain familiarity with movement phrases while allowing performers more space to move.When novel movement phrases are performed in groups, the individuals not dancing take to the sides of the studio and watch the individuals in the performing group.The dancers who take to the sides often use this time to mark the phrase as it is being performed.However, because motor stimulation and memory consolidation are promoted by observation alone, a strategy that discourages concurrent physical practice may be as ef fective as marking, but with the added advantage of being less distracting and more space-conscious.

Lastly, a note on verbal feedback supplementing action observation: Visual information does not necessarily benefit from synchronous auditory information[6].A novice dancer or a dancer learning a novel movement phrase will need to divide his or her attention between performing the phrase and remembering any verbal instruction[11].Therefore, a minimal amount of verbal feedback should be of fered to a moving, learning dancer so as not to exceed the individual’s attention-capacity limits[11].Unfortunately,providing too much verbal information can be like providing no verbal information at all.For this reason,it may not be constructive for dance teachers to relay corrections while dancers are performing.Rather, it may be of greater benef t to both the moving, learning dancer and the rest of the class to wait until after the dancers have finished performing to of fer verbal feedback.Teachers should direct the correction to the dancers to which it applies, and have the rest of the class listen to the feedback and observe its consequent application attempts.

IV.Observation While Injured

The present paper has addressed how observation can be used to augment learning within a dance class,but how might observation be utilised to supplement an injured dancer’s rehabilitation programme?Seeking alternative ways for injured dancers to remain integrated in dance classes can positively support their healing[14].One of these alternate routes is through inclass observation.Daniels proposes that injured dancers be invited to observe classes with a guided writing response form[14].While the form is a practical idea for class settings in which a grade is required, there is reason to believe that it should not be completed during an actual class.Injured dancers required to attend to a guided writing response form while watching a dance class may become too concerned with responding to prove their engagement that they never fully engage with what they watch.If continued learning, motor maintenance, and class integration is the goal of having an injured dancer observe, then writing during a class may shift the dancer away from that goal.Moreover,Daniels submits that the injured dancer can opt to either observe the class as a whole or watch a single peer[14].Implications of the AON have only been extrapolated from research studies involving one individual observing another individual.Therefore, a dancer may opt to observe one peer at a time, as it is unclear if a dancer will receive the same benefit by observing the class as a whole.

Mental imagery, a type of mental rehearsal that generates visual or kinaesthetic aspects of movement,has been chronicled for its success as an alternative dance training method in maintaining neuromuscular connections for the injured dancer[7,9,14].Yet because mental imagery and action observation share many cortical circuits and both strive to simulate motor representations, it seems logical that a practice of action observation could also be recommended to injured dancers as an alternate mode of training, either in combination with mental imagery or as its own modality.Furthermore, if mental imagery is regarded as fundamental to dance practice, then so too should action observation, for action observation is proven to enable effective mental imagery[7].

Mental imagery and action observation have historically been viewed as discrete modalities, and there are mixed results across studies that strive to compare their advantages[7].However, there is new evidence that supports the super-additive advantages of their combined application[15].The basis for its aggregate value is that action observation removes the necessity for individuals to generate their own mental image while still providing visual, auditory,and temporal cues for successful performance[7].This in turn liberates attentional space for the individuals to image crucial aspects of the movement (whatever those may be)[7].Under this assumption, action observation could very well be the external part on which mental imagery is projected in a distributed vehicle of thought.Experiments cited by Eaves et al.advocate for the pairing of action observation and mental imagery as a tool for motor learning and rehabilitation.In one study in particular, cortical-motor activity was significantly increased during a joint exercise of action observation and motor imagery in comparison to a practice of action observation or mental imagery alone[7].Therefore, an injured dancer may receive the most bene f t in terms of maintaining his or her motor repertoire by observing a peer perform a movement while simultaneously imagining themselves perform that movement.

将所有毕业要求达成度的评价结果进行汇总，对两个年级进行评价时，取两年最小值，如果所有毕业要求的达成度均大于0.65，则认为已达成毕业要求。

In a dance class, ensuring that all observers can clearly see the demonstration may warrant rotating students more frequently in the studio.It has long been presumed that the use of mirrors enhances learning,but there is evidence indicating visual information from the mirror is misleading, and thus diminishes kinaesthetic awareness and motor learning[2].Using the mirror to demonstrate or observe movement, especially when studios are crowded, may not enable the most effective visual processing.This is another instance when rotating a class may be beneficial.It can be argued that in a crowded studio, it is not advantageous to shuffle around that many individuals, and that the mirror is an invaluable tool to see movement from perspectives not probable without the mirror present.In that case, dance teachers, rather, should move around the studio themselves to demonstrate movement phrases from as many dif ferent angles and locations as possible.Nevertheless, the teacher should continue to demonstrate novel movement phrases as frequently as necessary because the more a dancer observes a demonstration, the more opportunity the dancer will have to acquire the movement pattern and parameterize the action[11].

V.Conclusion

The present paper seeks to unpack principles from motor learning theory and evidence from existing AON research to construct critiques of and considerations for current observational practices in dance class and while injured.While it is true, action observation cannot satisfy all of what full-out physical practice can—dance, after all, is a physical art form—it can ef fectively facilitate and/or supplement learning.By considering observation in the dance studio as well as observation for injured dancers, it can be concluded that dancers and teachers should be more intentional in how they approach observation.Although dancers and teachers may feel that by merely observing, dancers are being “lazy,” it is actually true that observation markedly exercises the motor mechanisms imperative to learning, re f ning, and maintaining motor representations.

There are a few limitations to the ar guments outlined in this paper.Because motor networks have not yet begun to crystallize in early development,this paper is more directed toward class settings and circumstances that occur during a dancer’s preprofessional and professional years.Arguments in this paper are based on the assumption that imaging is relatively easy for dancers, especially having not suffered from neurological impairment.Furthermore,arguments in this paper are constructed on evidence largely derived from still-image laboratory studies.Because of major methodological constraints, there are no studies that explore brain activity in the moving body or within a true dance environment.There is no certainty that studies using functional magnetic resonance imaging and transcranial magnetic stimulation carry back into a dance context.