Available online at www.sciencedirect.com ScienceDirect The role of attention in motor control and learning 1,2 Joo-Hyun Song Performing and learning motor behaviors are fundamental to task features, control motor commands, and make a everyday life. The relations between perceptual input and strategic decision [1–3]. motor output have been studied and are well understood for simple experimental settings. Recent findings, however, Historically, this integrated process has largely been suggest that motor actions also critically depend on cognitive studied by isolating specific subprocesses proposed by factors; these influences are most notable in complex an information-processing framework: sensory informa- environments that place high demands on attention and tion serves as input that is then used to construct an memory. In this review, the role of various aspects of attention internal representation of the world to guide decisions, in motor control is discussed, focusing on the following points: and these commands are executed via motor output. (1) recent findings concerning interactions between attentional Under this conventional, compartmentalized approach, resources and motor skill acquisition, (2) the consistency of it is not surprising that there has been little consideration attentional states (divided versus focused) and motor memory of cognitive influences on motor control (and vice versa) retrieval, and (3) the locus of attention (internal versus external) [4]. For instance, motor control research has focused on and motor performance. These findings collectively highlight factors such as biomechanics, postural control, and the interplay between attention and motor systems, which in reflexive constraints, which are directly related to the turn has practical implications for developing and improving neuromuscular system; conversely, the cognitive motor training and rehabilitation programs. literature has largely focused on factors such as attention, working memory, and decision-making – processes not Addresses typically regarded to be relevant for understanding motor 1 Department of Cognitive, Linguistic and Psychological Sciences, performance. Importantly, however, accumulating recent Brown University, RI 02912, United States 2 evidence suggests that various cognitive factors may Carney Institute for Brain Science, Brown University, Providence, RI 02912, United States impose fundamental constraints on the acquisition and performance of movements [5 ,6,7 ,8]. Corresponding author: Song, Joo-Hyun ([email protected]) In complex, real world environments, we must select and attend to goal-relevant information with limited cognitive Current Opinion in Psychology 2019, 29:261–265 resources while concurrently performing different This review comes from a themed issue on Attention and perception actions. This review focuses on three major topics empha- Edited by Sarah Shomstein, Andrew Leber and Joy Geng sizing the role of attention in motor learning and perfor- mance: (1) how attentional demands influence motor skill acquisition, (2) how the consistency of attentional states (e.g. divided versus focused) between motor learning and recall impacts skill transfer across the two phases, and (3) https://doi.org/10.1016/j.copsyc.2019.08.002 how the locus of attention (e.g. own performance versus 2352-250X/ã 2019 Elsevier Ltd. All rights reserved. performance environment) affects the overall perfor- mance. Taken together, these studies highlight the rela- tion between various attentional processes and motor performance and raise several practical implications for designing effective motor training programs. Furthermore, they demonstrate how considering mutual Acquiring, performing, and remembering pertinent motor influences between cognition and action can provide skills are integral to daily life. Importantly, motor skills exceptional research opportunities to enhance our under- are often performed in environments with high standing of adaptive human behaviors in real life. attentional demands. For example, during an emergency, a pilot must simultaneously operate the aircraft, assess its Attentional demand on acquisition of motor current integrity, and also maintain communications with skills ground authorities. Similarly, a stroke patient recovering To learn a new motor skill like a tennis serve, we monitor the ability to walk also has to divide her/his attention to performance to detect and evaluate movement errors, and cars, other pedestrians, and obstacles in the path in order also identify key transformations that map sensory to avoid collisions. Performing such actions in complex experience to update internal models for future use [9]. environments requires seamless coordination among In such a setting, attention is commonly viewed as a multiple processes to extract sensory information, learn necessary capacity-limited resource that facilitates www.sciencedirect.com Current Opinion in Psychology 2019, 29:261–265 262 Attention and perception multiple cognitive functions and resolves competition attention impairs immediate motor performance, thereby between these processes [10–12]. To investigate whether not considering how it affects memory formation and and how attentional demands influence motor skill retrieval. According to recent work [23,24,25 ,26], the learning, previous studies typically used a dual-task success of motor memory retrieval depends on whether paradigm. In this paradigm, the impairment of motor participants consistently perform the secondary task performance due to the concurrent secondary task is during motor learning and later recall stages, independent regarded as evidence for the necessity of attentional of available attentional resources per se. Specifically, resources in skill acquisition. Secondary tasks in such Song and Be´dard [25 ] asked participants to perform a studies range from tone counting to mental arithmetic visuomotor adaptation task either with or without a con- [13–18]. For example, many of these studies demonstrate current task (e.g. rapid serial visual presentation; RSVP). that performance in a serial reaction time task (SRT), They observed that performing the dual-task itself did where participants are trained to press a series of cued not affect impair immediate performance. Yet, when keys as quickly as possible, is impaired by the secondary participants were tested later during the recall phase, a task. In particular, these studies show that participants fail motor skill learned under the dual-task was remembered to learn the underlying repeated sequence when they only when a similar secondary task was present. When divide attention to a secondary task. This result is participants were tested without the secondary task, their largely consistent with the notion that attention is an performance reverted to untrained levels as though the information-processing resource involved in acquiring motor task had not been learned in the first place. Hence, new motor skills [13–15]. this paradoxical result, in which the level of performance decreases when more attentional resources are available, Dual-task deterioration of motor performance was also suggests that while the secondary task does not interrupt observed in other types of motor learning, including motor memory formation, the dual-task context, or the sensorimotor adaptation and dynamic force adaptation, lack thereof, acts as a vital context for learning. Interest- in which different functional and neural mechanisms are ingly, this task-context-dependent ‘savings’ in motor involved in sequence learning [19,20]. For instance, learning was evident even when the specific secondary Redding et al. [21] showed that simultaneously perform- task or sensory modality differed between learning ing a secondary cognitive task impaired the accuracy of (e.g. RSVP) and recall (e.g. sound discrimination). Thus, pointing in a prism adaptation task, in which the visual the general state of dividing attention during the dual- field was laterally displaced. Taylor and Thoroughman task, but not the specific parameters of stimuli, is [17] further specified which motor control process is associated with motor memory. impaired by the secondary task during force-field adaptation. In this task, participants were required to This reinstatement of attentional-context in visuomotor compensate for the force-induced errors during the move- memory retrieval appears to operate similarly to the ment and to use this information for later movements. environmental context in episodic memory retrieval They demonstrated that divided attention did not impair experiments that demonstrate benefits of having learning the within-movement feedback control, but did reduce and recall take place in consistent environmental subsequent movement adaptation. This suggests that contexts, highlighting encoding-specificity of episodic divided attention to the secondary task interferes with memory [27–29]; however, a notable difference is that a predictive motor control process operating across trials. consistent attentional contexts may form an internal cue In a subsequent task, they also showed that the degree of that overrides the external environmental cue formed by cognitive burden imposed by a secondary task resulted in different secondary tasks. Hence, as long as the atten- a proportional degradation of motor adaptation [16]. tional context integrated during motor memory formation is consistent learned motor skills can be retrieved even if To summarize, while participants need to monitor