基于fNIRS的运动执行与运动想象脑激活模式比较

使用《运动想象问卷−修订版》筛选出的30名被试(男女各半), 采用功能性近红外光谱成像技术(fNIRS)监测被试在执行实际举哑铃(男生, 4磅和8磅; 女生, 2磅和4磅)任务和想象举同等重量哑铃任务时, 其大脑皮层氧合血红蛋白浓度的变化。结果发现：男女被试在运动执行与运动想象任务下都激活了主运动皮层; 且运动执行的大脑激活水平高于运动想象。在执行实际运动任务时, 运动强度显著影响大脑皮层血氧浓度的变化, 表现出左半球偏侧化优势; 在执行想象运动任务时, 运动强度没有影响大脑皮层血氧浓度的变化, 且无偏侧化现象。     

Time for action versus action in time: time estimation differs between motor preparation and execution

Theories relating to time perception and motor performance predict very different temporal distortions depending on the synchronisation or succession of temporal processing and motor behaviour. However, our knowledge about the temporal difference between motor preparation and execution is still scarce. In order to expand on prior studies, two different time reproduction tasks were utilised to measure motor preparation and motor execution. We found that motor preparation of a planned action allows participants to complete the time reproduction task more accurately and, in short duration trials, less variably than for motor execution. Furthermore, under-reproduction was found in motor preparation compared to motor execution, which may be caused by increased temporal information processing. According to the attentional gate theory, more attention allocated to time processing and reduced motor distraction leads to less temporal distortion in the motor preparation. The findings are also important for designing to study consciousness, temporal and visual processing.     

动作的创造性操作与原型效应

对各种不同动作操作水平的被试,进行动作操作图式的操作实验。结果发现：１．经过系列动作的学习,可以形成动作原型。２．动作原型对于动作操作有影响作用,这种原型效应明显地表现在动作的创造性操作上。３．动作操作水平与动作原型效应有密切关系,动作原型效应,在操作水平高的人的动作操作上,表现最为明显。４．动作原型效应受背景条件所制约。     

Effects of repetitive motor training on movement representations in adult squirrel monkeys: role of use versus learning

Current evidence indicates that repetitive motor behavior during motor learning paradigms can produce changes in representational organization in motor cortex. In a previous study, we trained adult squirrel monkeys on a repetitive motor task that required the retrieval of food pellets from a small-diameter well. It was found that training produced consistent task-related changes in movement representations in primary motor cortex (M1) in conjunction with the acquisition of a new motor skill. In the present study, we trained adult squirrel monkeys on a similar motor task that required pellet retrievals from a much larger diameter well. This large-well retrieval task was designed to produce repetitive use of a limited set of distal forelimb movements in the absence of motor skill acquisition. Motor activity levels, estimated by the total number of finger flexions performed during training, were matched between the two training groups. This experiment was intended to evaluate whether simple, repetitive motor activity alone is sufficient to produce representational plasticity in cortical motor maps. Detailed analysis of the motor behavior of the monkeys indicates that their retrieval behavior was highly successful and stereotypical throughout the training period, suggesting that no new motor skills were learned during the performance of the large-well retrieval task. Comparisons between pretraining and posttraining maps of M1 movement representations revealed no task-related changes in the cortical area devoted to individual distal forelimb movement representations. We conclude that repetitive motor activity alone does not produce functional reorganization of cortical maps. Instead, we propose that motor skill acquisition, or motor learning, is a prerequisite factor in driving representational plasticity in M1.     

Rapid plastic changes of human primary motor cortex with repetitive motor practice and transcranial magnetic stimulation

Excitability changes of human primary motor cortex are assumed to be associated with motor learning processes. To examine motor behavioral and neural mechanisms in these processes, the adaptive motor learning processes of the index finger abduction were investigated using motor evoked potential (MEP) elicited from the first dorsal interosseous and extensor carpi radialis muscles. Practice effects were examined on changes of MEP amplitudes elicited from these muscles during motor imagery. Given general consensus that the MEP amplitude change during motor imagery is a useful parameter reflecting changes in excitability of the human primary motor cortex, the present results, that MEP amplitudes of both muscles increased with repeated practice by the index finger abduction and that magnitudes of MEP amplitudes of both muscles (motor learning curves) were clearly different, suggested that participation of the muscles performing the index finger abduction gradually changed with practice. Short-term plastic changes of human primary motor cortex occur with repetitive practice and such adaptive change in human primary motor cortex is expressed in human voluntary movement that becomes more automatic.     

Motor competence in fundamental motor skills and sport skill learning: Testing the proficiency barrier hypothesis

We investigated whether motor competence in fundamental motor skills influences sports motor skill learning. Motor competence in fundamental motor skills related to the overhead volleyball serve (i.e., throwing and volleying) was evaluated in 38 children (aged 9–10 yrs) and participants were divided into lower and higher motor competence groups. The groups practiced the volleyball serve under random or constant-random conditions during an acquisition phase and then assessed in pre-test, intermediate, and retention tests. A three-way repeated-measures ANOVA showed performance improvement from pre-test to retention test only for high motor competence groups in fundamental motor skills. Initial competence in fundamental motor skills influences sport skills learning and demonstrates a potential proficiency barrier to learning complex-sports motor skills.     

Computational approaches to motor control

This review will focus on four areas of motor control which have recently been enriched both by neural network and control system models: motor planning, motor prediction, state estimation and motor learning. We will review the computational foundations of each of these concepts and present specific models which have been tested by psychophysical experiments. We will cover the topics of optimal control for motor planning, forward models for motor prediction, observer models of state estimation arid modular decomposition in motor learning. The aim of this review is to demonstrate how computational approaches, as well as proposing specific models, provide a theoretical framework to formalize the issues in motor control.     

A comparison of characteristics,developmental disorders and motor progression between children with and without developmental coordination disorder

Background and aimChildren with Developmental Coordination Disorder (DCD) have difficulty in the development of motor coordination and with learning new motor skills. Studies demonstrate that children with DCD differ in terms of the nature and severity of their motor difficulties, the incidence of co occurring conditions and family background. However, little is known whether these profiles may relate to motor progression over time. The aim of this study was to describe the profiles of children with and without DCD and track motor progression over time.MethodThe characteristics of thirty-four 7–14 year old children (M = 10.07, 85.3% boys) with and without DCD were compared and their motor progression monitored over a two academic years. DCD was identified using DSM5 criteria. The Movement Assessment Battery for Children-2 (MABC-2) was used to classify children as TD (≥25th percentile), having moderate motor coordination difficulties (6-16th percentile) or severe motor coordination difficulties (≤ 5th percentile). The Kaufman Brief Intelligence Test – 2 (KBIT-2) was used to measure full scale IQ. Parent questionnaires were used to gather information on socio economic status and co occurrence of other developmental disorders. We used ANOVA to assess whether there were differences in characteristics between the TD children, children with severe motor coordination difficulties and children with moderate motor coordination difficulties. Linear mixed effect modelling was used to estimate any change in motor performance over time and whether this differed between the three groups of children.ResultsChildren with severe motor coordination difficulties had distinct profiles in motor and non-motor domains, lower IQ and a greater likelihood of having associated characteristics of 2 or more developmental disorders. We found significant differences between the poor motor performance of the severe group compared to the other two groups. Longitudinal analyses revealed stable, persistent and lower motor competence for the severe group. The rate of change in motor proficiency for the typical and severe groups was similar. However, the group with moderate motor difficulties gained on average more points per week compared to the typical group and achieved motor scores in the typically developing range over time.ConclusionsThis is one of the first studies to compare the characteristics and rate of motor progression of children with and without DCD using different motor proficiency cut off scores. The children with severe motor coordination difficulties progressed at the same rate as typically developing peers but remained in the severe group over time, whereas the children with moderate motor coordination difficulties caught up to TDC. The results indicate that different intervention may be required according to the nature and severity of the characteristics in both the motor and non-motor domains of children with DCD.     

幼儿动作发展与动作抑制研究

运用《儿童动作评估检查表》和停止信号任务,通过教师评定和即时行为实验方法,对40名4～6岁幼儿的动作发展水平、动作发展的内部结构、动作抑制的发展趋势和动作抑制与动作一般发展水平之间的关系进行了详细探讨。结果发现,4～6岁幼儿的动作处于一个迅速发展的时期;幼儿在自身与环境的静止或变动情况下,动作发展水平存在不平衡现象,当儿童自身静止并处于静止的环境中时,动作发展水平显著高于儿童自身移动和环境变动状态下的动作水平;男孩与女孩在动作发展的特定条件下存在差异。同时还发现,幼儿的动作反应抑制能力存在明显的年龄发展趋势,随着幼儿年龄的增长,其动作反应抑制能力增强;动作反应抑制能力与一般动作发展水平之间存在显著相关。     

Towards a better understanding of the association between motor skills and executive functions in 5- to 6-year-olds: The impact of motor task difficulty

Different lines of evidence suggest an association between motor skills and executive functions (EFs) in kindergarten children. Comparatively little is known about the specific nature of this relationship. In the present study, using a within-subjects design, a sample of 124 five- to six-year-old children completed 12 fine and gross motor tasks of varying nominal difficulty and three EFs tasks. We assumed that difficult motor tasks are less automated than easy motor tasks. Therefore, EFs should be involved more strongly in difficult compared to easy motor tasks. Firstly, results replicated the association between motor skills and EFs. Secondly, results provided a new and differentiated perspective on the evidence of this link. Performance on both easy and difficult fine motor tasks was significantly related to EFs. However, only performance on the difficult, but not on the easy gross motor tasks was significantly correlated with EFs. The findings demonstrate that the challenges and demands inherent in any motor task influence the magnitude of the motor–EFs link. That is, difficult (i.e., less automated) motor tasks require EFs more substantially than easy (i.e., more automated) motor tasks. Results will be discussed with regard to further candidate processes underlying the motor–EFs link.     

Differential reliance of chimpanzees and humans on automatic and deliberate control of motor actions

Humans are often unaware of how they control their limb motor movements. People pay attention to their own motor movements only when their usual motor routines encounter errors. Yet little is known about the extent to which voluntary actions rely on automatic control and when automatic control shifts to deliberate control in nonhuman primates. In this study, we demonstrate that chimpanzees and humans showed similar limb motor adjustment in response to feedback error during reaching actions, whereas attentional allocation inferred from gaze behavior differed. We found that humans shifted attention to their own motor kinematics as errors were induced in motor trajectory feedback regardless of whether the errors actually disrupted their reaching their action goals. In contrast, chimpanzees shifted attention to motor execution only when errors actually interfered with their achieving a planned action goal. These results indicate that the species differed in their criteria for shifting from automatic to deliberate control of motor actions. It is widely accepted that sophisticated motor repertoires have evolved in humans. Our results suggest that the deliberate monitoring of one’s own motor kinematics may have evolved in the human lineage.     

Evaluation of meditation and relaxation on physiological response during the performance of fine motor and gross motor tasks

This study investigated the effects of meditation/relaxation on physiological responses during the performance of a fine motor and a gross motor task. A pretest-posttest control group, randomized-blocks design was used to study a group of 16 meditators and a group of 16 nonmeditators, subgroups of each who relaxed prior to performing on a pursuit-rotor tracking device as a fine motor task and to performing the Luft cycle ergometer protocol to a heart rate of 70% of age-adjusted maximum heart rate as a gross motor task. During each of these tasks heart rate, systolic blood pressure, rate-pressure-product, and EMG activity of the frontalis muscle were monitored. No significant difference in the performance of either the fine motor or the gross motor task was noted for persons practicing meditation and persons who were nonmeditators but were given the opportunity to relax prior to a motor task. Likewise, no significant difference was noted in the pattern of response to the imposed fine motor or gross motor task by meditators or relaxed nonmeditators.     

Physical fitness and health indices in children, adolescents and adults with high or low motor competence

The overall purpose of the study was to examine if individuals with low motor competence achieve age-adequate fitness and health. A group of 149 children, adolescents, and adults with low or high motor competence participated in motor, fitness, and health assessments. Individuals with low motor competence did not differ on their basic physiological health parameters, but they had less optimal levels of overall health and fitness indices than those with high motor competence. As a function of age, musculoskeletal fitness was significantly compromised for the low motor competence group. The metabolic indices suggested that the low motor competence group had significantly higher BMI's compared to the high motor competence group. Motor skills and static balance were significant predictors of the BMI. Exercise intensity differed between children in the low and high motor competence group. The findings suggest that individuals with low motor competence have compromised health-related fitness. In order to discriminate between individuals with high and low motor competence, fitness assessment should include at least back extension, curl ups, and sit and reach. In addition, health-related fitness measurements such as BMI, waist circumference, blood lipid profile and bone mineral density are also recommended.     

Intention and Motor Representation in Purposive Action

Are there distinct roles for intention and motor representation in explaining the purposiveness of action? Standard accounts of action assign a role to intention but are silent on motor representation. The temptation is to suppose that nothing need be said here because motor representation is either only an enabling condition for purposive action or else merely a variety of intention. This paper provides reasons for resisting that temptation. Some motor representations, like intentions, coordinate actions in virtue of representing outcomes; but, unlike intentions, motor representations cannot feature as premises or conclusions in practical reasoning. This implies that motor representation has a distinctive role in explaining the purposiveness of action. It also gives rise to a problem: were the roles of intention and motor representation entirely independent, this would impair effective action. It is therefore necessary to explain how intentions interlock with motor representations. The solution, we argue, is to recognise that the contents of intentions can be partially determined by the contents of motor representations. Understanding this content‐determining relation enables better understanding how intentions relate to actions.     

Measuring motor imagery ability: A review

The internal nature of motor imagery makes the measurement of motor imagery ability a difficult task. In this review, we describe and evaluate existing measures of motor imagery ability. Following Jeannerod (1994, 1997) we define motor imagery in terms of imagined movement from the first person perspective. We describe how explicit motor imagery ability can be measured by questionnaire and mental chronometry, and how implicit motor imagery ability can be measured through prospective action judgement and motorically driven perceptual decision paradigms. Future research should be directed towards a theoretical analysis of motor imagery ability, the improvement of existing questionnaires and the development of new ones, and the standardisation of existing paradigms.     

The influence of motor function on processing speed in preterm and term-born children

This study investigates the relationship between motor function and processing speed in preterm children. Processing speed was compared in 145 adolescents, born 25–41 weeks gestational age, utilizing tasks including differing motor demands. The influence of motor cortex excitability and functional motor skills on task performance was assessed. For tasks with motoric demands, differences in performance between preterm and term-born children were mediated by the relationship between gestational age, corticomotor excitability, and motor function. There were no differences in non-motor processing speed task performance between preterm and term-born children. Measures of processing speed may be confounded by a timed motor component.     

Rapid modulation of distributed brain activity by Transcranial Magnetic Stimulation of human motor cortex

This paper reviews the effects of single and repetitive transcranial magnetic stimuli (rTMS) delivered to one cortical area and measured across distributed brain regions using electrophysiological measures (e.g. motor thresholds, motor evoked potentials, paired-pulse stimulation), functional neuroimaging (including EEG, PET and fMRI) and behavioural measures. Discussion is restricted to changes in excitability in the primary motor cortex and behaviour during motor tasks following transcranial magnetic stimulation delivered to primary motor and premotor areas. Trains of rTMS have lasting effects on the excitability of intrinsic and corticofugal neurones, altering the responsiveness of local and remote sites. These effects lead to distributed changes in synaptic activity at rest, and during a range of motor tasks. It is possible to impair or improve performance following rTMS, but for most simple motor tasks performance is unaltered. Changes in distributed activity observed with functional imaging during motor behaviour may represent compensatory activity, enabling maintenance of performance; stimulation of additional cortical areas appears to impair performance. A detailed understanding of the distributed changes in excitability following rTMS may facilitate future attempts to modulate motor behaviour in the healthy brain and for therapeutic purposes.     

Individual differences in language development: relationship with motor skill at 21 months

Language development has long been associated with motor development, particularly manual gesture. We examined a variety of motor abilities – manual gesture including symbolic, meaningless and sequential memory, oral motor control, gross and fine motor control – in 129 children aged 21 months. Language abilities were assessed and cognitive and socio‐economic measures controlled for. Oral motor control was strongly associated with language production (vocabulary and sentence complexity), with some contribution from symbolic abilities. Language comprehension, however, was associated with cognitive and socio‐economic measures. We conclude that symbolic, working memory, and mirror neuron accounts of language–motor control links are limited, but that a common neural and motor substrate for nonverbal and verbal oral movements may drive the motor–language association.     

A multi-systems theory of the structure and dynamics of motor functions

A theoretical analysis of the structure and dynamics of human motor functioning is presented from the perspective of a general theory of individuality. Within multifactor-systems theory, the structural units of the six systems of integrative personality (i.e., sensory, motor, cognitive, affect, style, and value) are hierarchical factor structures. Integrative functioning, both within and among systems, is described via the principles of general systems and information-processing theory. Our theoretical synthesis of the structure and dynamics of human motor functioning involves conceptualizing the hierarchy of motor factors as: (a) the basic dimensions of individual differences in the motor domain, (b) classes of decomposable motor programs that specify the spatio-temporal organization of behavior, and (c) decomposable classes of processing components entailed by motor programs. Some of the implications for understanding the role of affect in motor functioning and some research suggestions were presented.