Dominant paradigms in motor behavior research: the motor-action controversy revisited

In 1992, Abernethy and Sparrow published an evaluation of the historical development of the field of motor behavior research as published from 1977 up to 1988 in the Journal of Motor Behavior. The present study extends their evaluation from 1988 through 2005 using content analyses of articles on motor control and learning in this journal. Papers were categorized into the two dominant and contrasting paradigms, the motor systems approach and the action systems approach. Analysis suggests that the field of motor behavior research has changed considerably over the last three decades. The action systems approach is now the leading approach, but the motor systems approach has, however, not perished. In a Kuhnian perspective, the results might be consistent with a more long-lasting crisis, and from the available data it is not possible to predict a future outcome of the dispute between the two approaches.     

孤独症儿童动作发展障碍的神经机制

动作发展障碍(Developmental motor disorders)是孤独症谱系障碍的常见特征。通过系统回顾孤独症儿童动作发展障碍的神经科学研究, 发现γ-氨基丁酸和5-羟色胺浓度的改变及γ-氨基丁酸相关蛋白和Shank蛋白的表达异常不仅会损害中枢神经系统的发育, 而且还能导致突触兴奋性与抑制性失衡, 进而改变孤独症儿童小脑和大脑皮层运动区的功能连接。孤独症儿童小脑、基底神经节和胼胝体结构的改变对全脑的连通性产生了负面影响。神经生化机制和脑结构的异常共同导致了脑功能的异常, 最终造成孤独症儿童的动作发展障碍。此外, 动作发展障碍与孤独症核心症状共同的神经基础主要包括镜像神经元系统紊乱, 丘脑、基底神经节和小脑异常以及SLC7A5和PTEN 基因突变。未来研究需要关注与运动密切相关的其他神经递质, 如乙酰胆碱和多巴胺; 探索动作发展障碍神经网络的动态机制及其形成; 剖析该障碍的神经机制和自闭症核心症状神经机制的相互作用。     

Inhibitory mechanisms of attention in identification and localization tasks: time course and disruption.

It has been proposed that 1 component of the mechanism of visual selective attention is active inhibition of distracting information. A series of studies examines the time course of inhibition and the possible interfering effects of other task demands. Results demonstrate that inhibition can last at least 7 s after selection processes and that it is unaffected by predictable, unrelated intervening events. However, intervening events that are less predictable, or are the same as the inhibited stimulus, disrupt inhibition. Such results motivate a reconsideration of the previous view of distractor inhibition as a transient, fragile phenomenon.     

The utility of connectionism for motor learning: a reinterpretation of contextual interference in movement schemas

Using the general framework of schema theory, and building on it, the present article takes a connectionist approach to motor learning and to contextual interference effects. These phenomena were simulated in an exploratory manner in neural networks. The outcome closely reflects previous research with humans. In a simulated ballistic movement task, networks performed worse during practice but showed better transfer when target movement distances were presented in a random rather than a blocked fashion. Connectionism provides a parsimonious account of the effect in terms of properties inherent in the parallel distributed network.     

The neural circuitry supporting goal maintenance during cognitive control: a comparison of expectancy AX-CPT and dot probe expectancy paradigms

Goal maintenance is an aspect of cognitive control that has been identified as critical for understanding psychopathology according to criteria of the NIMH-sponsored CNTRICS (Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia) and Research Domain Criteria (RDoC) initiatives. CNTRICS proposed the expectancy AX-CPT, and its visual-spatial parallel the dot probe expectancy (DPX), as valid measures of the cognitive and neural processes thought to be relevant for goal maintenance. The goal of this study was to specifically examine the functional neural correlates and connectivity patterns of both goal maintenance tasks in the same subset of subjects to further validate their neural construct validity and clarify our understanding of the nature and function of the neural circuitry engaged by the tasks. Twenty-six healthy control subjects performed both the letter (AX) and dot pattern (DPX) variants of the CPT during fMRI. Behavioral performance was similar between tasks. The 2 tasks engaged the same brain networks including dorsolateral prefrontal cortex (DLPFC) and dorsal parietal regions, supporting their validity as complementary measures of the goal maintenance construct. Interestingly there was greater engagement of the frontal opercular insula region during the expectancy AX-CPT (letter) and greater functional connectivity between the PFC and medial temporal lobe in the DPX (dot pattern). These differences are consistent with differential recruitment of phonological and visual-spatial processes by the two tasks and suggest that additional long-term memory systems may be engaged by the dot probe version.     

自闭症谱系障碍者抑制控制的影响因素及神经机制

自闭症谱系障碍(ASD)是一种起源于儿童期的神经发育障碍, ASD的重复刻板行为与其抑制控制发展有密切关系。使用Go/No-go、Flanker及Stroop等范式的研究发现, ASD者抑制控制受损主要表现为反应抑制和干扰抑制能力存在缺陷; 其主要影响因素是任务状态、被试年龄及取样; 涉及的脑区和脑网络集中在前额皮层、前扣带回和基底神经节; 涉及的基因集中在谷氨酸盐、γ-氨基丁酸与5-羟色胺三种神经递质。未来应从脑机制研究入手, 综合考虑任务状态、个体特征对研究结果造成的影响, 并着力开发更有效的干预模式。     

Virtual environments for motor rehabilitation: review.

In this paper, the current "state of the art" for virtual reality (VR) applications in the field of motor rehabilitation is reviewed. The paper begins with a brief overview of available equipment options. Next, a discussion of the scientific rationale for use of VR in motor rehabilitation is provided. Finally, the major portion of the paper describes the various VR systems that have been developed for use with patients, and the results of clinical studies reported to date in the literature. Areas covered include stroke rehabilitation (upper and lower extremity training, spatial and perceptual-motor training), acquired brain injury, Parkinson's disease, orthopedic rehabilitation, balance training, wheelchair mobility and functional activities of daily living training, and the newly developing field of telerehabilitation. Four major findings emerge from these studies: (1) people with disabilities appear capable of motor learning within virtual environments; (2) movements learned by people with disabilities in VR transfer to real world equivalent motor tasks in most cases, and in some cases even generalize to other untrained tasks; (3) in the few studies (n = 5) that have compared motor learning in real versus virtual environments, some advantage for VR training has been found in all cases; and (4) no occurrences of cybersickness in impaired populations have been reported to date in experiments where VR has been used to train motor abilities.     

Shifting visual attention and selecting motor responses: distinct attentional mechanisms.

Does shifting visual attention require the same central mechanism as that required for selecting overt motor responses? In Experiment 1, Ss performed 2 tasks: a speeded manual response to a tone and an unspeeded report of a cued target letter in a brief masked array. Stimulus onset asynchrony (SOA) between tone and array was varied. If the attention shift to the target was delayed by the first task, then there should be more second-task errors at short SOAs and on trials with slow first-task responses. In fact, SOA effects and dependencies were minimal. Results were unchanged in further experiments in which the relation between cue and target was symbolic, spatially "unnatural," or based on the color of the target. Two additional experiments validated key assumptions of the method. The results confirm that although selection of motor responses constitutes a processing bottleneck, the control of visual attention operates independently of this bottleneck.     

Remembering intentions: A critical review of existing experimental paradigms

Remembering that one intends to do something is distinguished from remembering what one intends to do, and crucial design requirements for research on the former are elucidated. All of the few published studies on remembering intentions are classified into four possible research paradigms and are reviewed for design adequacy in the light of these crucial requirements. It is concluded that the best, but perhaps most difficult to implement, studies in the domain are those conducted under laboratory control in which one must remember to perform a single, repeated or multiple instances of natural-seeming behaviour that one perceives to be entirely irrelevant to the purposes of the study in which one is engaged.     

Cognition in schizophrenia: core psychological and neural mechanisms

The challenge in understanding cognitive impairment in schizophrenia is that people with this illness have deficits in an array of domains. Here, we briefly review evidence regarding the pattern of deficits within three domains: context processing, working memory and episodic memory. We suggest that there may be a common mechanism driving deficits in these domains - an impairment in the ability to actively represent goal information in working memory to guide behavior, a function we refer to as proactive control. We suggest that such deficits in proactive control reflect impairments in dorsolateral prefrontal cortex, its interactions with other brain regions, such as parietal cortex, thalamus and striatum, and the influence of neurotransmitter systems, such as dopamine, GABA and glutamate.     

Beyond inattentional blindness and attentional misdirection: From attentional paradigms to attentional mechanisms

Memmert (2010) tried to foster the development of attentional research by discussing four differences between attentional misdirection (AM) and inattentional blindness (IB). Considering this goal, the comment was received in the intended way by the comments of (Most, 2010) and (Moran and Brady, 2010) who make a number of highly valuable suggestions for further progress. As initially suggested by Memmert (2010) this dialog should help unravel the underlying attentional mechanisms of different paradigms. Therefore, we first discuss the suggested distinction between central and spatial IB by Most (2010). Second, we argue that working memory and perceptual load research seem particularly interesting in this regard and should be taken into consideration when conducting future research along the lines of IB and AM. Third, representative task designs can be an important mosaic piece in across-the-board attention theories and highly useful for deriving further testable hypothesis in naturalistic settings. The most important claim of all commentaries in this issue is that the proposed ideas can all be empirically tested and thereby contribute to the advancement of an unified theoretical framework incorporating IB, AM in consideration of overt and covert attention mechanisms.     

大众与个人审美品位的认知与神经机制

大众与个人的审美品位分别代表了审美活动在个体间的一致性和差异性。将大众品位和个人品位相结合的新趋势正在挑战传统的"普遍性"审美法则,并日益凸显审美反应的个体差异。存在诸多因素可以调节大众和个人审美品位的相对比例,包括刺激类型、专业性、文化背景、先前经验和年龄等。大众与个人审美品位的神经机制中,奖赏系统和默认模式网络扮演重要角色。目前,审美品位与审美加工模型的理论关系有待进一步厘清和验证。未来相关研究可以在拓展审美对象领域、完善大众与个人审美品位与不同审美加工阶段的对应关系等方向上继续开展。     

Cognitive mechanisms of visuomotor transformation in movement imitation: Examining predictions based on models of apraxia and motor control

When we observe a movement and then reproduce it, how is this visual input transformed into motor output? Studies on stroke patients with apraxia suggest that there may be two distinct routes used for gesture imitation; an indirect route that recruits stored movement memories (motor programs) and a direct route that bypasses them. The present study examined 30 healthy adults ages 18–80 (mean age = 44.0 years, SD = 19.5) to learn how motor programs are recruited or bypassed in movement imitation depending upon task conditions (whether familiar letters or novel shapes are imitated) and perceptual factors (whether shapes or letters are perceived). Subjects were asked to imitate the movements of a model who formed shapes and letters on a sheer mesh screen, and to report whether they perceived the task as a shape or a letter. Movements were recorded using a Vicon motion analysis system, and subsequently analyzed to determine the degree of difference between the demonstrated and produced movements. As predicted, letter perception on the letter tasks resulted in increased temporal error when the demonstrated stroke order conflicted with subjects’ habitual pattern of letter formation. No such interference effects were observed when the letter tasks were perceived as shapes. These findings are discussed in the context of current theories on imitation, and implications for rehabilitation and motor re-learning are presented.     

Application of two neural network paradigms to the study of voluntary employee turnover.

Two neural network paradigms--multilayer perceptron and learning vector quantization--were used to study voluntary employee turnover with a sample of 577 hospital employees. The objectives of the study were twofold. The 1st was to assess whether neural computing techniques offered greater predictive accuracy than did conventional turnover methodologies. The 2nd was to explore whether computer models of turnover based on neural network technologies offered new insights into turnover processes. When compared with logistic regression analysis, both neural network paradigms provided considerably more accurate predictions of turnover behavior, particularly with respect to the correct classification of leavers. In addition, these neural network paradigms captured nonlinear relationships that are relevant for theory development. Results are discussed in terms of their implications for future research.     

Age of acquisition: its neural and computational mechanisms

The acquisition of new skills over a life span is a remarkable human ability. This ability, however, is constrained by age of acquisition (AoA); that is, the age at which learning occurs significantly affects the outcome. This is most clearly reflected in domains such as language, music, and athletics. This article provides a perspective on the neural and computational mechanisms underlying AoA in language acquisition. The authors show how AoA modulates both monolingual lexical processing and bilingual language acquisition. They consider the conditions under which syntactic processing and semantic processing may be differentially sensitive to AoA effects in second-language acquisition. The authors conclude that AoA effects are pervasive and that the neural and computational mechanisms underlying learning and sensorimotor integration provide a general account of these effects.