Monocular and Binocular Vision in the Control of Goal-Directed Movement

In the present research the authors examined the time course of binocular integration in goal-directed aiming and grasping. With liquid-crystal goggles, the authors manipulated vision independently to the right and left eyes of 10 students during movement preparation and movement execution. Contrary to earlier findings reported in catching experiments (I. Olivier, D. J. Weeks, K. L. Ricker, J. Lyons, & D. Elliott, 1998), neither a temporal nor a spatial binocular advantage was obtained in 1 grasping and 2 aiming studies. That result suggests that, at least in some circumstances, monocular vision is sufficient for the precise control of limb movements. In a final aiming experiment involving 3-dimen- sional spatial variability and no trial-to-trial visual feedback about performance, binocular vision was associated with greater spatial accuracy. Binocular superiority appeared to be most pronounced when participants were unable to adjust their limb control strategy or procedure on the basis of terminal feedback about performance.     

Force and Directional Force Modulation Effects on Accuracy and Variability in Low-Level Pinch Force Tracking

The authors investigated how varying the required low-level forces and the direction of force change affect accuracy and variability of force production in a cyclic isometric pinch force tracking task. Eighteen healthy right-handed adult volunteers performed the tracking task over 3 different force ranges. Root mean square error and coefficient of variation were higher at lower force levels and during minimum reversals compared with maximum reversals. Overall, the thumb showed greater root mean square error and coefficient of variation scores than did the index finger during maximum reversals, but not during minimum reversals. The observed impaired performance during minimum reversals might originate from history-dependent mechanisms of force production and highly coupled 2-digit performance.     

Impact of Tactile Sensation on Dexterity: A Cross-Sectional Study of Patients With Impaired Hand Function After Stroke

The authors sought to explore the impact of tactile sensation on manual dexterity and the validity of the strength-dexterity test in subjects with chronic impairments after stroke in a cross-sectional study of 24 patients with impaired hand function after stroke. Dexterity was assessed by the strength-dexterity test, Box and Blocks, and Nine-Hole Peg Test, and the ABILHAND questionnaire. Sensation was measured by pinprick, cotton-wool, graphesthesia, and 2-point discrimination tests. Sensation in the paretic hand had strong association with paretic hand performance in the strength-dexterity test and Nine-Hole Peg Test and explained 13% of the variance. Sensation in the nonparetic hand was associated with the results of the ABILHAND questionnaire. Among sensory tests, 2-point discrimination had the strongest association with dexterity tests. No significant correlations between sensation, pinch force, and dexterity tests were found for the nonparetic hand. The strength-dexterity test exhibited strong correlations with the other dexterity measures and with pinch force. There is an association between tactile sensation and dexterous performance in the paretic hand; activity level performance is associated with sensation in the nonparetic hand. The study supports the validity of the strength-dexterity test when applied in subjects in the chronic stage after stroke.     

Grip Force-Load Force Coupling Is Influenced by Altered Visual Feedback about Object Kinematics

Abstract

Recent evidence suggests that visual feedback influences the adjustment of grip force to the changing load force exerted by a grasped object as it is manipulated. The current project investigated how visual feedback of object kinematics affects the coupling of grip force to load force by scaling the apparent displacements of the object viewed in virtual reality. Participants moved the object to manually track a moving virtual target. The predictability of the changing load force exerted by the object was also manipulated by altering the nature of target trajectories (and therefore the nature of object motions). When apparent object displacements increased in magnitude, grip force became more tightly coupled to load force over time. Furthermore, when load force variations were less predictable, the magnitude of apparent object displacements affected the relative degree of continuous versus intermittent coupling of grip force to load force. These findings show that visual feedback of object motion affects the ongoing dynamical coupling between grip force control and load force experienced during manipulation of a grasped object.     

Lateralization of the Approach Movement and the Prehension Movement in Infants from 4 to 7 Months

The aim of the study was to analyse lateralized preferences during reaching and grasping in infants relative to changes in manual actions from 4 to 7 months of age. Reaching and grasping movements with visual fixation were studied with objects placed in one of three places on a table: to the left, to the right and in the midline of the infant. Although the two lateralized objects were approached and grasped with ipsilateral hand, movements towards the object in the midline were most often performed with a preferential hand. There was preferential use of the left hand for reaching around the fourth month, then a preferential use of the right hand for grasping from the sixth month. The shape of the left hand during reaching movements terminated in the vicinity of the object. The slower the speed, the closer the hand came to the object. The onset of the prehension was associated with a preferential use of the right hand, which performed grasping, more finely than the left hand. Thus, manual specialization is already present in early infancy: the left hand appears to be dedicated to spatial calibration and the right hand to the task of prehension.     

Bimanual Lifting: Do Fingertip Forces Work Independently or Interactively?

Bimanual coordination is a commonplace activity, but the consequences of using both hands simultaneously are not well understood. The authors examined fingertip forces across 4 experiments in which participants undertook a range of bimanual tasks. They first measured fingertip forces during simultaneous lifts of 2 identical objects, noting that individuals held the objects with more force bimanually than unimanually. They then varied the mass of the objects held by each hand, noting that when both hands lifted together performance was equivalent to unimanual lifts. The authors next measured one hand's static grip force while the other hand lifted an object. They found a gradual reduction of grip force throughout the trial, but once again no evidence of one hand influencing the other. In the final experiment the authors tested whether tapping with one hand could influence the static grip force of its counterpart. Although the authors found no changes in static grip force as a direct consequence of the other hand's actions, they found clear differences from one task to the other, suggesting an effect of task instruction. Overall, these results suggest that fingertip forces are largely independent between hands in a bimanual lifting context, but are sensitive to different task requirements.     

Dynamics of Pushing

A standing individual can use several strategies for modulating pushing force magnitude. Using a static model, researchers have shown that the efficacy of those strategies varies considerably. In the present article, the authors propose a human motor control dynamic model for analyzing transients that occur when an individual is asked to modulate force magnitude. According to the model, the impedances of both the upper and the lower limbs influence the time course of force variations and foot placement has a profound effect on pushing force dynamics. With a feet-together posture, the center of pressure has a limited range of motion and changes in force may be preceded by initial changes in the opposite direction; that is, to decrease force, an individual must first increase force. When the feet are placed apart, individuals can move the center of pressure over a much larger range, thereby modulating pushing force magnitude, without reversing behavior, over a larger range of force magnitudes. Therefore, the best way to control pushing force at the hand may be by using the foot.     

旋转任务中3～5岁儿童空间物体位置编码的研究

本实验探讨3~5岁儿童在对空间物体位置进行编码时,能否有效采用心理旋转策略或根据物体"位置关系"来判断物体方位。实验采用3×4混合设计,在旋转条件下研究上述问题。结果表明:(1)在策略方面,儿童对心理旋转的使用要显著优于利用位置关系进行判断;(2)随着年龄增长,心理旋转的能力不断提高,5岁时进步尤其明显;(3)3~5岁儿童均不能自动利用位置关系对物体位置进行编码,但5岁儿童经提示后可采用此策略。     

Motor Performance and Response Consistency as a Function of Age

The specificity versus generality of motor performance and motor response consistency was investigated as a function of age. 120 Ss, 30 each at age 7, 11, 15, and 19 yr., were given 120 practice trials (60 trials per session with 24 hr interpolated between sessions) on both simple and choice RT tasks. For motor performance the reliability of individual differences was high in both tasks at all ages, while the amount of generality was moderately high in the two younger groups but diminished with age. The reliability coefficients for motor response consistency were low for both tasks but, with two exceptions, statistically significant. There was no evidence for generality in motor response consistency at any age.     

The Lateral Coding of Rotations

A number of experimental studies have consistently shown the locus of spatial S-R compatibility effects to be the selection of the response within an abstract memory code. The purpose of the present study was to test, in the particular case of wheel rotations, the general proposition that any response that a subject internally codes in terms of left and right may be interfered with by the lateral location of the stimuli in a Simon paradigm. Experiment 1 showed that the auditory Simon effect occurred in a task where the subjects had to rotate a steering wheel bimanually either clockwise or counterclockwise according to sound pitch, despite the fact that responses of this kind are undefined with respect to laterality. Experiment 2 confirmed this result in a unimanual rotation condition and suggested that the ear-rotation compatibility effect may be added to the effect of a biomechanical factor, pronation versus supination, supporting the idea of an abstract motor code. In Experiment 3, subjects rotated the steering wheel with their hands on the lowest part of the wheel. When the response movement made the spot of a C.R.T. move laterally in accordance with the performed rotation, the subjects coded their response directly in terms of its effect on the visual display. For subjects not receiving visual feedback, no compatibility effect occurred. However, the individual data were compatible with the notion that some subjects in this group coded their responses in terms of wheel rotations, and others in terms of hand movements.     

言语编码和视空编码在时间—空间联结中的作用

时间和空间存在反应编码联合效应（spatial—temporal association of response codes effect, STEARC）,该效应的编码是视觉空间性还是言语性还存在争议。本研究借鉴Georges（2015）的研究方式,以2秒内的时距为刺激,实验1采用言语反应和空间反应,词语和空间与时距的关系分为一致和不一致。结果发现言语反应时,短时距用“左边”反应快,长时距用“右边”反应快,空间反应时,时距和空间的一致性效应消失,表明言语编码参与两种反应形式的STEARC效应。实验2将词语改为箭头朝向（视觉编码条件）,发现视觉编码和空间编码存在于相对应的反应形式中。研究表明时空关系的编码形式与具体任务要求有关。     

Applications of the Speed–Accuracy Trade-off and Impulse-Variability Theory for Teaching Ballistic Motor Skills

Bridging the gap between innovative research and teaching is a fundamental necessity for physical education practitioners to promote motor skill development and competency. This requires practitioners to understand, synthesize, and appropriately apply relevant research from different academic domains in their instructional environments. Ballistic motor skills such as kicking, throwing, and striking are fundamentally integrated into many games and sports and provide a foundation for physical activity and fitness for children and adults. Unfortunately, many individuals do not attain a high level of competence in these types of skills by adolescence. The purpose of this review is to integrate theory, pedagogical best practices, and current evidence on studies relating to Fitts’ Law’s application of the speed–accuracy trade-off and impulse-variability theory to provide an evidence-based framework for promoting effective instructional environments for learning ballistic motor skills.     

The Logic of Location

I consider the idea of a propositional logic of location based on the following semantic framework, derived from ideas of Prior. We have a collection L of locations and a collection S of statements such that a statement may be evaluated for truth at each location. Typically one and the same statement may be true at one location and false at another. Given this semantic framework we may proceed in two ways: introducing names for locations, predicates for the relations among them and an “at” preposition to express the value of statements at locations; or introduce statement operators which do not name locations but whose truth-conditional effect depends on the truth or falsity of embedded statements at various locations. The latter is akin to Prior’s approach to tense logic. In any logic of location there will be some basic operators which we can define. By ringing the changes on the topology of locations, different logical systems may be generated, and the challenge for the logician is then in each case to find operators, axioms and rules yielding a proof theory adequate to the semantics. The generality of the approach is illustrated with familiar and not so familiar examples from modal, tense and place logic, mathematics, and even the logic of games.

相似文献   

The Location of Properties

This paper argues that, assuming properties exist and must be located in spacetime, the prevailing view that they are exactly located where their instances are is false. Instead a property is singularly located at just one region, namely the union of its instance's locations. This bears not just on issues in the metaphysics of properties, but also on the debate over whether multi‐location is conceivable and/or possible (and, by proxy, any theory that relies on that e.g. certain formulations of endurantism/perdurantism).     

The development of temporal coordination in children

The ability to learn temporal patterns in sequenced actions was investigated in elementary-school age children. Temporal learning depends upon a process of integrating timing patterns with action sequences. Children ages 6-13 and young adults performed a serial response time task in which a response and a timing sequence were presented repeatedly in a phase-matched manner, allowing for integrative learning. The degree of integrative learning was measured as the slowing in performance that resulted when phase-shifting the sequences. Learning was similar for the children and adults on average but increased with age for the children. Executive function measured by Wisconsin Card Sorting Test (WCST) performance as well as a measure of response speed also improved with age. Finally, WCST performance and response speed predicted temporal learning. Taken together, the results indicate that temporal learning continues to develop in pre-adolescents and that maturing executive function or processing speed may play an important role in acquiring temporal patterns in sequenced actions and the development of this ability.     

4-6岁儿童在小模型旋转任务中的线索学习与位置学习*

以90名4-6岁儿童为被试,探讨了儿童在小模型旋转任务中利用线索学习和位置学习表征空间位置的年龄特点。研究结果表明:(1)儿童对线索学习的利用要优于对位置学习的利用;(2)4岁儿童已经可以使用线索学习的方式表征空间位置,但到6岁左右才开始能够使用基于方向的位置学习;(3)线索特征对于儿童的线索学习有显著影响,明显、突出的线索有利于儿童的线索学习。     

The Assertive Interaction Coding System

Conceptual and theoretical issues concerning the assessment of assertive behavior are discussed. A summary of a variety of instruments utilized in experimental and clinical settings is offered that reflects these issues. This review is followed by the presentation of a new assessment device developed by the authors—the Assertive Interaction Coding System. Research evidence as to its reliability and validity in experimental and clinical settings is presented. Implications for its use in clinical and research protocols are addressed.     

Visual‐motor and executive functions in children born preterm: The Bender Visual Motor Gestalt Test revisited

Böhm, B., Lundequist, A. & Smedler, A.‐C. (2010). Visual‐motor and executive functions in children born preterm: The Bender Visual Motor Gestalt Test revisited. Scandinavian Journal of Psychology, 51, 376–384. Visual‐motor development and executive functions were investigated with the Bender Test at age 5½ years in 175 children born preterm and 125 full‐term controls, within the longitudinal Stockholm Neonatal Project. Assessment also included WPPSI‐R and NEPSY neuropsychological battery for ages 4–7 ( Korkman, 1990 ). Bender protocols were scored according to Brannigan & Decker (2003) , Koppitz (1963) and a complementary neuropsychological scoring system (ABC), aimed at executive functions and developed for this study. Bender results by all three scoring systems were strongly related to overall cognitive level (Performance IQ), in both groups. The preterm group displayed inferior visual‐motor skills compared to controls also when controlling for IQ. The largest group differences were found on the ABC scoring, which shared unique variance with NEPSY tests of executive function. Multiple regression analyses showed that hyperactive behavior and inattention increased the risk for visual‐motor deficits in children born preterm, whereas no added risk was seen among hyperactive term children. Gender differences favoring girls were strongest within the preterm group, presumably reflecting the specific vulnerability of preterm boys. The results indicate that preterm children develop a different neurobehavioral organization from children born at term, and that the Bender test with a neuropsychological scoring is a useful tool in developmental screening around school start.     

Bilateral Transfer as a Function of Mental Imagery

Three experiments are reported which investigate the role of mental imagery in the bilateral transfer from right to left hand of rotary pursuit skill. In Experiment 1 both mental imagery and physical rehearsal showed significant positive transfer relative to a control condition. However, work decrement may have accumulated and transferred in the physical rehearsal group thereby depressing this group’s left-hand performance. Experiment 2 was conducted under conditions designed to allow work decrement to dissipate prior to transfer to the contralateral limb. The data still showed no difference between physical re-hearsal and mental imagery. One interpretation of these data is that work decrement was present under both the physical rehearsal and mental imagery manipulations in Experiment 1. The data from Experiment 3 confirmed this interpretation as well as replicated the positive transfer effects found for mental imagery in Experiments 1 and 2. The data are discussed in terms of central versus peripheral explanatory mechanisms.     

论政治道德的定位

政治生活的整合和政治文明的建设要求对政治道德进行合理的定位。政治道德的定位问题既涉及政治道德体系的内容问题,又关涉什么样的政治道德才是合理的问题。政治道德应该定位于政治公共领域这一客观基础;应该定位于个人权利与公共利益相结合的视角;应该定位于目的（或者功利）与道义（或者义务）的统一。