Asymmetries in the Regulation of Visually Guided Aiming

An experiment was conducted to examine the contribution of sensory information to asymmetries in manual aiming. Movements were performed in four vision conditions. In the full-vision condition (FV), subjects were afforded vision of both the hand and the target throughout the course of the movement. In the ambient-illumination-off condition (AO), the room lights were extinguished at movement initiation, preventing vision of the moving limb. In the target-off (TO) condition, the target was extinguished upon initiation of the movement. In a no-vision (NV) condition, ambient illumination was removed and the target was extinguished upon initiation of the response movement. Results indicated that accuracy was superior in the full-vision and target-off conditions and when movements were made by the right hand. Movements made by the right hand were also of shorter mean duration. The magnitudes of performance asymmetries were uninfluenced by vision condition. Analyses of movement kinematics revealed that movements made in conditions in which there was vision of the limb exhibited a greater number of discrete modifications of the movement trajectory. On an individual-trial basis, no relationship existed between accuracy and the occurrence of discrete modifications. These data suggest that although vision greatly enhances accuracy, discrete modifications subserved by vision reflect the imposition of nonfunctional zero-order control processes upon continuous higher-order control regimes.     

Coupling of Eye,Finger, Elbow,and Shoulder Movements During Manual Aiming

Temporal and spatial coupling of point of gaze (PG) and movements of the finger, elbow, and shoulder during a speeded aiming task were examined. Ten participants completed 40-cm aiming movements with the right arm, in a situation that allowed free movement of the eyes, head, arm, and trunk. On the majority of trials, a large initial saccade undershot the target slightly, and 1 or more smaller corrective saccades brought the eyes to the target position. The finger, elbow, and shoulder exhibited a similar pattern of undershooting their final positions, followed by small corrective movements. Eye movements usually preceded limb movements, and the eyes always arrived at the target well in advance of the finger. There was a clear temporal coupling between primary saccade completion and peak acceleration of the finger, elbow, and shoulder. The initiation of limb-segment movement usually occurred in a proximal-to-distal pattern. Increased variability in elbow and shoulder position as the movement progressed may have served to reduce variability in finger position. The spatial-temporal coupling of PG with the 3 limb segments was optimal for the pick up of visual information about the position of the finger and the target late in the movement.     

"人工美女"意味着什么--浅析"人工美女"效应

"人工美女"的产生是社会进步、思想开放的结果,也是市场经济发展结果.一方面,社会进步、思想开放,给予美容受术者以足够的尊重和理解,使他们有了选择不同生活方式的自由,敢于公开"露脸";另一方面,市场经济的发展使她们愿意公开"露脸".而商家为谋取经济利益,打着"人工美女"的旗号,刻意进行商业炒作,将伤及广大消费者,危及美容外科行业.我们应以科学的态度、实事求是的精神予以坚决抵制,倡导在追求形体美和容貌美的同时,注重心灵美的培养,营造出一种真、善、美的社会环境.     

Determining the Temporal Limits of a Visual Sample for Visual Regulation

The author examined the minimum amount of time needed for vision to increase aiming accuracy and decrease movement duration. Participants selected when they would receive a visual sample during aiming movements by pressing a switch held with the left hand. The sample was one of the following durations: 40 ms, 30 ms, 20 ms, 10 ms, or 0 ms (no vision). Decreased accuracy in the no-vision condition compared to the vision conditions was observed when the duration of the impending sample was unknown (Experiment 1). Samples 40 ms in duration were sufficient to decrease endpoint variability when the duration of the sample was known before the movement (Experiment 2). These results indicate that short visual samples can be used to decrease movement time and increase accuracy and that knowledge of the impending visual context can impact the individual's subsequent behavior.     

The Role of Oculomotor Information in the Learning of Sequential Aiming Movements

With their eyes initially on either the home, midline, or final end position, 30 participants practiced a 2-target aiming movement. After 120 acquisition trials, participants performed a retention test and were then transferred to each of the other 2 eye conditions. During acquisition, all groups improved over practice, but the home group showed the greatest improvement. The temporal improvement was most pronounced in the times spent after peak velocity. Retention and transfer tests indicated that participants performed best under eye-movement conditions that were the same as the 1 they had practiced in. There was also positive transfer of training between conditions in which the oculomotor information was similar. Thus, to optimize learning, one should practice under the same afferent and oculomotor conditions that will be required for the final performance.     

EVALUATION OF A TRAINING MANUAL FOR THE ACQUISITION OF BEHAVIORAL ASSESSMENT INTERVIEWING SKILLS

Two procedures were used to teach behavioral assessment interviewing skills: a training manual and one-to-one instruction that included modeling, rehearsal, and feedback. Two graduate students and two advanced undergraduates were trained with each procedure. Interviewing skills were recorded in simulated assessment interviews conducted by each student across baseline and treatment conditions. Each training procedure was evaluated in a multiple baseline across students design. The results showed that both procedures were effective for training behavioral interviewing skills, with all students reaching a level of 90%-100% correct responding. Finally, a group of experts in behavior analysis rated each interviewing skill as relevant to the conduct of an assessment interview and a group of behavioral clinicians socially validated the outcomes of the two procedures.     

The Role of Consistent Context in Rapid Movement Planning: Suboptimal Endpoint Adjustment to Changing Rewards

The authors' purpose was to determine if participants adjusted their endpoint during a rapid aiming task in the context of changing rewards and whether participants needed consistent feedback to do so. Participants aimed to a target that was overlapped by a penalty region. Participants gained points for hitting the target but lost points for hitting the penalty region. The reward value associated with target contact either changed trial to trial, reducing consistent feedback (variable condition) or changed between blocks of trials (blocked condition) with the repetition of reward value within a block increasing the consistency of feedback. Participants adjusted their endpoints with changing reward value in the blocked but not variable condition indicating consistent feedback is needed to adjust endpoint to changing rewards.     

The Coding of Location

One prediction of the recent target hypothesis for movement control (MacNeilage, 1970; Russell, 1976) holds that location reproduction is not solely dependent upon stored kinesthetic information. Three experiments were performed to test this prediction by requiring the subject to reproduce the location with the limb opposite to the one used for criterion production. This switched-limb procedure was assumed to force the subject to rely upon more abstract information rather than the kinesthetic cues of the criterion movement. With movement direction invariant, switched-limb reproduction was equal to same-limb reproduction. The alteration of movement direction hampered switched-limb reproduction but same-limb reproduction was not greatly affected. These findings gave some support to the target hypothesis but suggested that the context of the movement may affect the potency of the location code. Implications of the switched-limb technique for future research were briefly discussed.     

Kinesthetic Compensation for Sensorimotor Rearrangements

ABSTRACT

The authors report a new sensorimotor phenomenon in which participants use hand-sensed kinesthetic information to compensate for rotational sensorimotor rearrangements. This compensation benefits from conscious awareness and is related to hand posture. The technique can reduce control inefficiency with some misalignments by as much as 64%. The results support Y. Guiard's (1987) Guiard, Y. 1987. Asymmetric division of labor in human skilled bimanual action. Journal of Motor Behavior, 19: 486–517. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] suggestion that in bimanual tasks one hand provides an operational frame of reference for the other hand as in a closed kinematic chain. Results with right-handed participants show that the right and left hands are equally effective at providing such a cue. A constant-angular-targeting-error model, similar to that used for hand movements by H. Cunningham and I. Vardi (1990) and for walking by S. K. Rushton, J. M. Harris, M. R. Lloyd, and J. P. Wann (1998), is used to model the trajectories of targeting hand movements demonstrating the phenomenon. The model provides a natural parameter of the error.     

Self-Selected Visual Information During Discrete Manual Aiming

The authors examined strategic selection of visual samples during manual aiming. Participants (N = 12) wore liquid-crystal goggles while performing discrete movements to a small target. Initially, participants controlled a 40-ms visual sample via a switch in their nonaiming hand. Subsequently, experimenter-imposed strategies required participants to take visual samples before movement initiation or early or late in the movement. Although participants adopted a variety of strategies to optimize the use of vision, they were more likely to select a sample during the early stages of the movement. Experimenter-imposed early and late instructions resulted in longer movement times than did self-selected sampling. Compared with late sampling, early sampling resulted in a temporal advantage with similar accuracy.     

Effects of Target Presentation Time,Recall Delay,and Aging on the Accuracy of Manual Pointing to Remembered Targets

The issues addressed in 2 experiments in which 10 younger and 10 older adults participated were (a) whether the retention of a target location in memory for motor control purposes would be facilitated by an increase in target presentation time; (b) whether increasing the recall delay since the last exposure to the target would have deleterious effects on aiming accuracy or variability, or both; and (c) whether those effects would be mediated by aging. The results revealed that there is a short-lived (< 1 s) visual representation of target location. In addition, the results suggested that the nature of that representation dictates a movement strategy favoring higher peak movement velocity. None of the effects reported in the present study was affected by age, suggesting that the coding and retrieving processes of target location in memory for motor control purposes are not affected by age.     

Slow Motor Responses to Visual Stimuli of Low Salience in Autism

ABSTRACT

The authors studied 2 tasks that placed differing demands on detecting relevant visual information and generating appropriate gaze shifts in adults and children with and without autism. In Experiment 1, participants fixated a cross and needed to make large gaze shifts, but researchers provided explicit instructions about shifting. Children with autism were indistinguishable from comparison groups in this top-down task. In Experiment 2 (bottom-up), a fixation cross remained or was removed prior to the presentation of a peripheral target of low visual salience. In this gap–effect experiment, children with autism showed lengthened reaction times overall but no specific deficit in overlap trials. The results show evidence of a general deficit in manual responses to visual stimuli of low salience and no evidence of a deficit in top-down attention shifting. Older children with autism appeared able to generate appropriate motor responses, but stimulus-driven visual attention seemed impaired.     

Manualizing psychotherapy: Aaron T. Beck and the origins of Cognitive Therapy of Depression

Abstract

This paper examines the origins of psychiatrist Aaron T. Beck’s 1979 Cognitive Therapy of Depression (CTOD). CTOD was the first psychotherapy manual designed to be used in a randomized controlled trial (RCT). Making psychotherapy amenable to the RCT design had been a ‘holy grail’ for leading American psychotherapy researchers since the late 1960s. Beck’s CTOD – which standardized his treatment so it could be compared with drug treatments in a clinical trial – delivered that holy grail, and ushered in the manualized treatment revolution. Manuals are now a sine qua non in psychotherapy research. In this paper, I explore some of the personal, political, and economic variables that made the idea of a manual irresistible to Beck and to those who first championed him.     

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.     

ACQUISITION AND CROSS-SETTING GENERALIZATION OF MANUAL SIGNS WITH SEVERELY RETARDED INDIVIDUALS

In this study, we assessed the effect of a transfer of stimulus control procedure on the acquisition and cross-setting generalization of manual signs with four profoundly retarded individuals. Two individuals were trained to produce appropriate signs to verbal instructions, whereas the other two were trained until manual signs were controlled by visual stimuli (objects). Data obtained from three probe situations (two for one individual) constituted the dependent variables of the investigation. The results, gathered within a multiple-baseline design across signs showed that (a) individuals acquired the trained signs and (b) maintenance and generalization across settings (classroom, ward) and persons (teachers, ward staff) occurred, but was highly variable between and within individuals.     

空间-时间联合编码效应：来自手动和眼动证据

本研究探讨汉语背景下不同反应方式（手动,眼动）、不同方位（水平,垂直）上空间-时间联合编码效应（STEARC效应）存在的可能性。四个实验均采用两类时间词语诱发被试的时间表征,采用2（时间：过去、将来）×2（反应手/眼跳方向：左、右/上、下）的被试内设计。结果表明汉语背景下的人们将过去和身体左边（上）联系在一起,把将来和右边（下）联系在一起,人们存在自左向右和自上而下的STEARC效应,这种效应不存在手动和眼动的分离,人们对时间的表征不仅是一条时间线,更是一个心理时间地图。     

Attachment-based family therapy for depressed adolescents: programmatic treatment development

Few effective psychosocial treatment models for depressed adolescents have been developed, let alone ones that use the developmentally potent context of the family as the focus of intervention. Attachment-based family therapy (ABFT) is a brief, manualized treatment model tailored to the specific needs of depressed adolescents and their families. Attachment theory serves as the main theoretical framework to guide the process of repairing relational ruptures and rebuilding trustworthy relationships. Empirically supported risk factors for depression are the primary problem states that therapists target with specific treatment strategies or tasks. Parent problem states include criticism/hostility, personal distress, parenting skills, and disengagement. Adolescent problem states include motivation, negative self-concept, poor affect regulation, and disengagement. Intervention tasks include relational reframing, building alliances with the adolescent and with the parent, addressing attachment failures, and building competency. A small, randomized clinical trial provides initial support for the model. Several process research studies, using both qualitative and quantitative methods, have helped refine the clinical guidelines for each treatment task. ABFT is a promising new treatment for depressed adolescents and more research on it is warranted.     

RELAXATION EXERCISE WITH CEREBRAL PALSIED ADULTS SHOWING SPASTICITY

A method for improving the muscle incoordination associated with cerebral palsy was empirically tested. Relaxation exercises, involving the successive tensing and relaxing of the major muscle groups of the body, were performed by four adults with spastic quadraplegia. All four subjects were sheltered workshop employees. Their IQs ranged from normal to mentally deficient. Testing consisted of two timed-trials of both the Placing Test and the Turning Test from the Minnesota Rate of Manipulation Tests. These tests measured the amount of time required to complete various manual manipulations involving pegs and pegboard. A multiple baseline across subjects design was employed to provide experimental control. All subjects showed significant improvement over baseline performance on the tests following the relaxation training. Limitations of this preliminary investigation and implications of these results for future research were noted.     

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.