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Purpose: To compare the objective performance, acceptance and usability of head‐mounted displays (HMDs) to provide evidence‐based data that could be used to increase the efficiency of device referrals based upon a person's vision loss and functional needs. Methods: A cross‐sectional, counterbalanced, individually controlled crossover study was performed on 15 adults with various eye conditions. Performance was measured when using four HMDs: eSight4, Eyedaptic EYE3, Eyedaptic EYE4 and IrisVision Inspire. Performance on clinical visual acuity tests and contrast were assessed, as well as vision‐related activities of daily living (ADL) which were divided into three categories: Reading, Searching & Identifying and Eye–hand Coordination. User‐experience was also assessed. Logistic regression analyses, Friedman one‐way repeated measure analyses of variance by ranks and multivariate permutation testing were used for analysis. Results: There was a significant improvement in visual acuity when using all devices. For contrast tasks, only the eSight4 and Eyedaptic EYE3 improved performance relative to baseline. For most Reading and Searching & Identifying tasks, the odds of being able to perform the tasks were significantly higher while using the devices. However, the actual performance with most devices (e.g., number of words read or reading speed) did not improve significantly over baseline for most tasks. For the Eye–hand Coordination tasks, participants performed equivalent to or significantly poorer than baseline when using the devices. No demographic or clinical predictors of outcomes were identified. Participants expressed dissatisfaction with the devices' effectiveness, acceptability and usability. Conclusions: While performance on clinical tests was better when using the devices, performance on most real‐world ADLs was equal to or worse than baseline. No single device improved performance on all tasks, and performance on any one task was not improved with all the devices. The overall dissatisfaction with the devices paralleled the lack of objective improvement in the performance of real‐world tasks. [ABSTRACT FROM AUTHOR]

The posterior parietal cortex (PPC) integrates multisensory and motor‐related information for generating and updating body representations and movement plans. We used retrograde transneuronal transfer of rabies virus combined with a conventional tracer in macaque monkeys to identify direct and disynaptic pathways to the arm‐related rostral medial intraparietal area (MIP), the ventral lateral intraparietal area (LIPv), belonging to the parietal eye field, and the pursuit‐related lateral subdivision of the medial superior temporal area (MSTl). We found that these areas receive major disynaptic pathways via the thalamus from the nucleus of the optic tract (NOT) and the superior colliculus (SC), mainly ipsilaterally. NOT pathways, targeting MSTl most prominently, serve to process the sensory consequences of slow eye movements for which the NOT is the key sensorimotor interface. They potentially contribute to the directional asymmetry of the pursuit and optokinetic systems. MSTl and LIPv receive feedforward inputs from SC visual layers, which are potential correlates for fast detection of motion, perceptual saccadic suppression and visual spatial attention. MSTl is the target of efference copy pathways from saccade‐ and head‐related compartments of SC motor layers and head‐related reticulospinal neurons. They are potential sources of extraretinal signals related to eye and head movement in MSTl visual‐tracking neurons. LIPv and rostral MIP receive efference copy pathways from all SC motor layers, providing online estimates of eye, head and arm movements. Our findings have important implications for understanding the role of the PPC in representation updating, internal models for online movement guidance, eye‐hand coordination and optic ataxia. [ABSTRACT FROM AUTHOR]

Objective: We introduced learning curves on a detailed step protocol and ergonomic aspect to determine key surgical points in transumbilical single‐port laparoscopic hysterectomy (TSPLH) and to popularize both technical and cognitive methodology on laparoendoscopic single‐site surgery (LESS). Materials and Methods: A retrospective analysis of 87 TSPLH procedures was conducted by a single surgeon in three learning stages. Technical, ergonomic, and cognitive steps were introduced, and surgical outcomes were analyzed. Results: Key production points in TSPLH include developing a clear retroperitoneal space, maintaining appropriate strength and direction with a vaginal manipulator, coagulating the uterine artery, and applying an improved vaginal stump suturing method. Technical factors included instrument domination, hand–eye coordination, and alternating hand functions. Ergonomic techniques focused on shoulder, elbow, arm, wrist, and finger movements, range of motion, muscle power, continuous forces, and flexibility. Improved cognitive factors such as confidence, decision‐making, and communication were also observed. Conclusions: The study aimed to form methodological education on TSPLH and LESS and benefit more surgeons. The detailed production and key ergonomic points will help guide self‐learning and education. Synopsis: The study improves transumbilical single‐port laparoscopic hysterectomy by introducing learning curves on technical, ergonomic, and cognitive aspects, benefiting more surgeons. [ABSTRACT FROM AUTHOR]

Fast movements like saccadic eye movements that occur in the absence of sensory feedback are thought to be controlled by internal feedback. Such internal feedback provides an instantaneous estimate of the output, which serves as a proxy for sensory feedback, that can be used by the controller to correct deviations from the desired plan. In the predominant view, the desired plan/input is encoded in the form of a static displacement signal (endpoint model), believed to be encoded in the spatial map of the superior colliculus (SC). However, recent evidence has shown that SC neurons have a dynamic signal that correlates with saccade velocity, suggesting that information for velocity‐based control is available for generating saccades. Motivated by this observation, we used a novel optimal control framework to test whether saccadic execution could be achieved by tracking a dynamic velocity signal at the input. We validated this velocity tracking model in a task where the peak saccade velocity was modulated by the speed of a concurrent hand movement independent of the saccade endpoint. A comparison showed that in this task, the velocity tracking model performed significantly better than the endpoint model. These results suggest that the saccadic system may have additional flexibility to incorporate a velocity‐based internal feedback control when imposed by task goals or context. [ABSTRACT FROM AUTHOR]

Previous studies reported that adolescents with a sport-related concussion history showed prolonged visuomotor deficits during an eye-hand decoupling task until around 1.5–2 years post-event. The present study expands this work, examining whether such deficits do or do not emerge when testing individuals in young adulthood, i.e. later post-event. Twenty-one non-athlete college students with sport-related concussion history from adolescence (CH; M = 21 yrs.; M = 46 months post-concussion, range 10–90 months) and twenty controls with no history of concussion (NoH; M = 21 yrs.) performed two touchscreen-based visuomotor tasks. It included a coupled task where eyes and hand moved in similar directions, and decoupled-task with eyes and hand going to different directions. Movement planning (e.g. reaction time, initial direction error) and execution (e.g. movement time, path length) related variables were analyzed in both groups and conditions. Movement execution measures were similar for both groups and conditions (all p > 0.05). However, movement planning was impaired in the CH participants in the eye-hand decoupling condition (p < 0.05). CH's initial direction error was larger (i.e. worse spatial movement planning) than in the NoH group. Although movement execution deficits shown in earlier work in youth were not present in young adults, the present results suggest that a sport-related concussion sustained in adolescence can lead to prolonged deficits with spatial movement planning processes while performing eye-hand decoupling tasks about four years post-injury. Further research should investigate whether these deficits continue into adulthood and expand control on time since concussion and number of concussion metrics. Highlights Young adult college students with a history of a sport-related concussion from adolescence, tested about four years post-incident, showed spatial movement preparation deficits during an eye-hand decoupling visuomotor task. Eye-hand reversal decoupling errors also correlated with time since concussion in those with concussion history. These prolonged eye-hand decoupling deficits may emerge with ongoing time post-event, as comparable deficits were absent in previous work where youth were tested sooner post-injury. Our current findings point towards long-lasting performance impairments in young adult non-athletes after a sport-related concussion from adolescence. [ABSTRACT FROM AUTHOR]

Specific thalamic nuclei are implicated in healthy aging and age‐related neurodegenerative diseases. However, few methods are available for robust automated segmentation of thalamic nuclei. The threefold aims of this study were to validate the use of a modified thalamic nuclei segmentation method on standard T1 MRI data, to apply this method to quantify age‐related volume declines, and to test functional meaningfulness by predicting performance on motor testing. A modified version of THalamus Optimized Multi‐Atlas Segmentation (THOMAS) generated 22 unilateral thalamic nuclei. For validation, we compared nuclear volumes obtained from THOMAS parcellation of white‐matter‐nulled (WMn) MRI data to T1 MRI data in 45 participants. To examine the effects of age/sex on thalamic nuclear volumes, T1 MRI available from a second data set of 121 men and 117 women, ages 20–86 years, were segmented using THOMAS. To test for functional ramifications, composite regions and constituent nuclei were correlated with Grooved Pegboard test scores. THOMAS on standard T1 data showed significant quantitative agreement with THOMAS from WMn data, especially for larger nuclei. Sex differences revealing larger volumes in men than women were accounted for by adjustment with supratentorial intracranial volume (sICV). Significant sICV‐adjusted correlations between age and thalamic nuclear volumes were detected in 20 of the 22 unilateral nuclei and whole thalamus. Composite Posterior and Ventral regions and Ventral Anterior/Pulvinar nuclei correlated selectively with higher scores from the eye‐hand coordination task. These results support the use of THOMAS for standard T1‐weighted data as adequately robust for thalamic nuclear parcellation. [ABSTRACT FROM AUTHOR]

Objectives: It is well known that a good microsurgeon needs eight important factors: a high resolution view, an optimally magnified view, optimal brightness of the working field, optimal working space, fine surgical instruments and devices, fine motor skills, precise hand-eye coordination, and fine visual perceptions. Of these factors, the first five are highly depending on manufacturer development abilities. The remaining factors have a lots of possibilities that microsurgeons can improve by themselves. A microsurgeon needs to identify shape, size, angle, inclination, length, height, depth, spatial position, centering in the optical field, orthogonality, and parallelism in a second. Knowing one's tendency and acuity in perceptions, learning perceptions that one is not good at, and paying selective attention on one's difficult perceptions, will provide better surgical outcome. Aim of this series of research is designing visual targets measuring specific visual perceptions for microsurgeons, achieving mean values of each perceptions, and identifying the tendency on each perceptions. Material and Methods: Two hundred and eighty volunteer dentists in Japan and France were tested and multiple comparisons were made among age, gender, visual acuity, three magnification levels, and inclination angles against a standard target. Results and Coclusion: There is a tendency that identifying 1° misalignment in parallelism is difficult. [ABSTRACT FROM AUTHOR]

Introduction: Development of dexterity, hand‐eye coordination and self‐assessment are essential during the preclinical training of dental students. To meet this requirement, dental simulators have been developed combining virtual reality with a force feedback haptic interface. The aim of this study was to assess the capability of the VirTeaSy© haptic simulator to discriminate between users with different levels of practical and clinical experience. Materials and Methods: Fifty‐six volunteers divided into five groups (non‐dentists, 1st/3rd/final‐year dental students, recent graduates) had three attempts to prepare an occlusal amalgam cavity using the simulator. Percentages of volumes prepared inside (%IV) and outside (%OV) the required cavity, skill index and progression rate, referring to the evolution of skill index between trials 1 and 3, were assessed. The dental students and recent graduates completed a questionnaire to gather their opinions about their first hands‐on experience with a haptic simulator. Results: The results showed no significant difference between the groups at the first attempt. Following the third attempt, the skill index was improved significantly. Analysis of progression rates, characterised by large standard deviations, did not reveal significant differences between groups. The third attempt showed significant differences in skill index and %IV between 1st‐year undergraduate dental students and both non‐dentists and recent dental graduates. The questionnaire indicated a tendency for dental operators to consider the simulator as a complement to their learning and not a substitute for traditional methods. Conclusion: This study did not show the ability of a basic aptitude test on VirTeaSy© haptic simulator to discriminate between users of different levels of expertise. Optimisations must be considered in order to make simulation‐based assessment clinically relevant. [ABSTRACT FROM AUTHOR]

Objective: Build a microlaryngoscopy surgical simulator for endoscopic laryngeal surgery using standard microsurgical instruments and a CO2 laser. Study design: Anatomical modeling, CAD design and 3D printed manufacturing. Subjects and methods: We created a modular design for a microlaryngoscopy simulator in CAD software. Components include plastic and stainless‐steel models of a standard operating laryngoscope and a cassette system for mounting porcine or synthetic models of the vocal folds. All simulator parts, including the metallic laryngoscope model, were manufactured using 3D printing technology. Tumors were simulated in porcine tissue models by injecting a soy protein‐based tumor phantom. Residents and faculty in the Louisiana State University otolaryngology department evaluated the system. Each participant performed microlaryngoscopy with laser resection on a porcine larynx and cold instrument procedures on synthetic vocal folds. Participants scored the simulator using a 5‐point Likert scale. Results: The microlaryngeal surgical simulator demonstrated in this project is realistic, economical, and easily assembled. We have included 3D printed parts files and detailed assembly instructions that will enable educators interested in surgical simulation to build the device. Participants in the simulator evaluation session felt that the simulator faithfully represented the procedure to resect vocal fold lesions using a CO2 laser. The synthetic model allows the trainee to develop hand‐eye coordination while using standard laryngeal instruments. Conclusions: The simulator described herein will enable surgeons to acquire the surgical skills necessary to perform operative microlaryngoscopy prior to operating on live patients. [ABSTRACT FROM AUTHOR]

Stereo matching algorithms have been developed for many years but basically focus only on the implementation of existing datasets and are rarely applied to real scenarios, such as industrial robot scenarios. Traditional stereo matching algorithms have a high error rate, and deep learning algorithms are difficult to obtain good results in real scenarios because of their weak generalisation ability and difficult access to training data. In order to use stereo matching algorithms for industrial robot guidance, it is better to design a new traditional algorithm with low time complexity for the characteristics of industrial robot scenarios dominated by planar facets. This paper proposes a new matching method based on subrows of pixels, instead of individual pixels, in order to improve robustness of matching and reduce running time. First, the pixel strings from the same row of the left and right images are divided into several colour‐identical or colour‐gradient segments. Then, the colour and length of the two left and right pixel segment are used as clues to determine a matching relation and obtain the matching type. Then, all match types can be determined according to non‐crossing mapping. Each match type can reason backward to the corresponding spatial state of the stimulus source so that the disparity of pixels in pixel segments representing the spatial state can be calculated. This new matching method makes full use of the stimulus homology constraints and projective geometric constraints of row‐aligned images. The method can obtain good results in industrial robot scenarios and be applied for industrial robot guidance. [ABSTRACT FROM AUTHOR]

Virtual reality (VR) has been applied to many fields such as visualization, architecture, education, medical science, and sports simulation. Recent VR advancements allow direct manipulation of three‐dimensional (3D) objects in interactive displays, but problems of inefficiency in movement due to inaccuracy in depth perception have been reported. As human interaction in virtual environments (VE) is being realized, factors that may affect depth perception and movement need to be addressed. This study investigated the effects of viewing angle, stereo viewing technology, and visual cues on hand movement performance in a 3D movement task. Ten right‐handed participants performed continuous Fitts' pointing tasks using a computer mouse. Participants were asked to move a cursor to a target ball as quickly as possible. Fitts' law was employed to test effects to capture differences while the hand was moving in the 3D space under three factors, angle of declination, visual depth, and space cue and with varied index of difficulty (ID). Movement time (MT), error rate, and throughput (TP) were recorded as dependent variables. This study found significant effects of angle of declination, visual depth, space cue, and ID. This study investigated the effectiveness of hand movements in 3D environments for a further immersive VE using a two‐dimensional (2D) mouse. Potential applications of this research include the design of interactive 3D display interfaces in which fast and accurate selection is required and the manipulation of 3D objects in 3D environments may be expected. [ABSTRACT FROM AUTHOR]

Social interactions provide a crucial context for early learning and cognitive development during infancy. Action prediction—the ability to anticipate an observed action—facilitates successful, coordinated interaction and is an important social‐cognitive skill in early development. However, current knowledge about infant action prediction comes largely from screen‐based laboratory tasks. We know little about what infants' action prediction skills look like during real‐time, free‐flowing interactions with a social partner. In the current study, we used head‐mounted eyetracking to quantify 9‐month‐old infants' visual anticipations of their parents' actions during free‐flowing parent–child play. Our findings reveal that infants do anticipate their parents' actions during dynamic interactions at rates significantly higher than would be expected by chance. In addition, the frequency with which they do so is associated with child‐led joint attention and hand‐eye coordination. These findings are the first to reveal infants' action prediction behaviors in a more naturalistic context than prior screen‐based studies, and they support the idea that action prediction is inherently linked to motor development and plays an important role in infants' social‐cognitive development. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=9HrmcicfiqE [ABSTRACT FROM AUTHOR]

Multilayered 3D vascular replicas incorporating the complementary advantages of elastomers and hydrogels can serve as a training platform to realistically simulate endovascular intervention, the preferred therapeutic procedure for cardio‐cerebrovascular disease. However, the fabrication process is challenging because of the difficulty in uniformly coating a thin hydrogel layer only on the inner surface of tortuous 3D vascular replicas composed of an elastomer monolayer. This study proposes an effective strategy to design and produce high‐fidelity 3D vascular replicas composed of elastomer–hydrogel multilayers by coating hydrogel polymers with robust interfaces only on the inner surface of the elastomer monolayer. The thin hydrogel layer can impart soft surface elasticity, lubricity, and superaerophobicity to the elastomer monolayer with high bulk elasticity, with deionized water alone as the circulating liquid, without the aid of additional lubricants. Owing to the complementary properties of the elastomers and hydrogels, multilayered 3D vascular replicas facilitate the control of medical devices and internal circulation of fluids, enabling realistic simulations of endovascular intervention under optical images in addition to X‐ray angiography. Furthermore, through practice courses, neurosurgeons demonstrated that the multilayered 3D vascular replicas are a reasonable platform for developing hand–eye coordination with pre‐procedure simulations and case‐specific training on demanding surgical sites. [ABSTRACT FROM AUTHOR]

Aim: We examined the association between having at least one parent born abroad and being diagnosed with a developmental disorder related to speech and language, academic skills or coordination.Methods: This nested case-control study was based on Finnish population records for 1996-2007. Cases from the Finnish Hospital Discharge Register were diagnosed with developmental disorders of speech and language, academic skills and coordination by the end of 2012. We identified 28 192 cases and 106 616 matched controls.Results: Children were more likely to be diagnosed with developmental disorders if they had an immigrant mother than children with two Finnish-born parents, with an adjusted odds ratio (aOR) of 1.3 and 95% confidence interval (95% CI) of 1.2-1.4, an immigrant father (aOR 1.2, 95% CI 1.1-1.3) or two immigrant parents (aOR 1.5, 95% CI 1.3-1.6). The level of development of the parental country of origin was not associated with receiving a diagnosis.Conclusion: Children of immigrant parents were more likely to be diagnosed with developmental disorders and the association was strongest with regard to speech and language disorders. There were similar adjusted odds ratios for mothers, fathers and both parents. The development level of the country of origin was irrelevant. [ABSTRACT FROM AUTHOR]

The present article shows that infant and dyad differences in hand-eye coordination predict dyad differences in joint attention (JA). In the study reported here, 51 toddlers ranging in age from 11 to 24 months and their parents wore head-mounted eye trackers as they played with objects together. We found that physically active toddlers aligned their looking behavior with their parent and achieved a substantial proportion of time spent jointly attending to the same object. However, JA did not arise through gaze following but rather through the coordination of gaze with manual actions on objects as both infants and parents attended to their partner's object manipulations. Moreover, dyad differences in JA were associated with dyad differences in hand following. [ABSTRACT FROM AUTHOR]

An experiment tested the effects of dyad membership and the prospect of completing a motor-skills task on alcohol placebo consumption and task confidence. Participants ( n = 115) completed a taste preference task while alone or in dyads. Half the individuals and half the dyads expected to subsequently complete a motor-skills task and rated task confidence pre and post-consumption. Individuals expecting the task consumed less than those in the non-task condition and felt less confident in their abilities post-consumption. Among those expecting the task, dyad members' consumption did not reduce and their post-consumption confidence was higher than individuals'. Findings suggest dyad membership can lead to overconfidence. Attempts to reduce alcohol related harms must balance the protective properties of dyads with risks of overconfidence. [ABSTRACT FROM AUTHOR]

Joint attention has been extensively studied in the developmental literature because of overwhelming evidence that the ability to socially coordinate visual attention to an object is essential to healthy developmental outcomes, including language learning. The goal of this study was to understand the complex system of sensory-motor behaviors that may underlie the establishment of joint attention between parents and toddlers. In an experimental task, parents and toddlers played together with multiple toys. We objectively measured joint attention-and the sensory-motor behaviors that underlie it-using a dual head-mounted eye-tracking system and frame-by-frame coding of manual actions. By tracking the momentary visual fixations and hand actions of each participant, we precisely determined just how often they fixated on the same object at the same time, the visual behaviors that preceded joint attention and manual behaviors that preceded and co-occurred with joint attention. We found that multiple sequential sensory-motor patterns lead to joint attention. In addition, there are developmental changes in this multi-pathway system evidenced as variations in strength among multiple routes. We propose that coordinated visual attention between parents and toddlers is primarily a sensory-motor behavior. Skill in achieving coordinated visual attention in social settings-like skills in other sensory-motor domains-emerges from multiple pathways to the same functional end. [ABSTRACT FROM AUTHOR]

ABSTRACT The dorsal premotor cortex (PMd) is part of the cortical network for arm movements during reach-related behavior. Here we investigate the neuronal projections from the PMd to the midbrain superior colliculus (SC), which also contains reach-related neurons, to investigate how the SC integrates into a cortico-subcortical network responsible for initiation and modulation of goal-directed arm movements. By using anterograde transport of neuronal tracers, we found that the PMd projects most strongly to the deep layers of the lateral part of the SC and the underlying reticular formation corresponding to locations where reach-related neurons have been recorded, and from where descending tectofugal projections arise. A somewhat weaker projection targets the intermediate layers of the SC. By contrast, terminals originating from prearcuate area 8 mainly project to the intermediate layers of the SC. Thus, this projection pattern strengthens the view that different compartments in the SC are involved in the control of gaze and in the control or modulation of reaching movements. The PMD-SC projection assists in the participation of the SC in the skeletomotor system and provides the PMd with a parallel path to elicit forelimb movements. J. Comp. Neurol. 523:2390-2408, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Volitional motor control generally involves deciding 'where to go' and 'how to go there'. Understanding how these two constituent pieces of motor decision coordinate is an important issue in neuroscience. Although the two processes could be intertwined, they are generally thought to occur in series, whereby visuomotor planning begins with the knowledge of a final hand position to attain. However, daily activities are often compatible with an infinity of final hand positions. The purpose of the present study was to test whether the reach endpoint ('where') is an input of arm motor planning ('how') in such ecological settings. To this end, we considered a free pointing task, namely arm pointing to a long horizontal line, and investigated the formation of the reach endpoint through eye-hand coordination. Although eye movement always preceded hand movement, our results showed that the saccade initiation was delayed by ~ 120 ms on average when the line was being pointed to as compared with a single target dot; the hand reaction time was identical in the two conditions. When the latency of saccade initiation was relatively brief, subjects often performed double, or even triple, saccades before hand movement onset. The number of saccades triggered was found to significantly increase as a function of the primary saccade latency and accuracy. These results suggest that knowledge about the reach endpoint built up gradually along with the arm motor planning process, and that the oculomotor system delayed the primary reach-related saccade in order to gain more information about the final hand position. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to determine changes and interrelationships between changes in selected anthropometric growth parameters and motor and physical fitness, among boys over a 2 year period during mid‐adolescence. Methods: Speed, agility, hand‐eye coordination, explosive power, muscle strength, and aerobic endurance were measured once a year, and the anthropometric measurements (stature, body mass, sitting height, arm span, and sitting height ratio), were measured three times per year, 4 months apart (among 73 adolescent boys). A hierarchical linear model, adjusting for covariates and partial correlation analysis (R2) were used to analyze the data. Results: All anthropometric, motor, and physical measurements improved significantly over the two‐year period. Significantly, greater changes were seen between 13 and 14 years in stature, arm span, sitting height and body mass. Changes in muscle strength, speed and agility were mainly significant between 13 and 14 years while the biggest changes occurred in explosive power and upper‐body‐arm‐and‐shoulder‐strength during year 2 (14–15 years). The majority of interrelationships, indicating moderate to small relationships, were found between changes in stature, arm span, and sitting height, and changing strength, speed, agility, and hand eye coordination over the two‐year period, after adjusting for maturity age and physical activity levels. Conclusion: Motor and physical fitness improved significantly from 13 to 15 years, showing definite interrelationships with anthropometric growth during the mid‐adolescence period. Awareness and education about these changes are recommended as it can have significant effects on the sport performance and fitness training of boys during mid‐adolescence. Am. J. Hum. Biol. 26:617–626, 2014. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

When we make hand movements to visual targets, gaze usually leads hand position by a series of saccades to task-relevant locations. Recent research suggests that the slow smooth pursuit eye movement system may interact with the saccadic system in complex tasks, suggesting that the smooth pursuit system can receive non-retinal input. We hypothesise that a combination of saccades and smooth pursuit guides the hand movements towards a goal in a complex environment, using an internal representation of future trajectories as input to the visuomotor system. This would imply that smooth pursuit leads hand position, which is remarkable, as the general idea is that smooth pursuit is driven by retinal slip. To test this hypothesis, we designed a video-game task in which human subjects used their thumbs to move two cursors to a common goal position while avoiding stationary obstacles. We found that gaze led the cursors by a series of saccades interleaved with ocular fixation or pursuit. Smooth pursuit was correlated with neither cursor position nor cursor velocity. We conclude that a combination of fast and slow eye movements, driven by an internal goal instead of a retinal goal, led the cursor movements, and that both saccades and pursuit are driven by an internal representation of future trajectories of the hand. The lead distance of gaze relative to the hand may reflect a compromise between exploring future hand (cursor) paths and verifying that the cursors move along the desired paths. [ABSTRACT FROM AUTHOR]

One must be quick and precise when foveating targets to be reached, because the eyes have to guide the hand trajectory by visual feedback, and we may miss a rapidly moving target if our grasping is not fast and accurate enough. To this end, our brains developed mechanisms coordinating gaze and hand movements to optimize the way in which we foveate and reach. One of these mechanisms is the facilitation of the primary saccade - proven in humans and confirmed here in monkeys - which allows the generation of short-latency gaze movements when reaching towards visual targets. Here we tested whether the neuronal activity in the superior colliculus (SC) accounts for this mechanism; alternatively, cortical saccade-related areas could play a major role in the fast initiation of saccades during such elaborated behaviours bypassing the SC. Upon presentation of a target, neurons located at the rostral pole of the SC started the saccade-related pause in their activity earlier in tasks involving coordinated gaze-reach movements than in tasks in which the saccades were made in isolation. In the same tasks neurons located at the caudal SC reached peak firing rates earlier in coordinated gaze-reach movements than with isolated saccades, confirming the tight coupling between their burst activity latencies and the saccadic reaction times. In sum, our results extend the role of the SC in saccade initiation to coordinated gaze-reach movements, identifying its activity as an important part of the distributed neural system for eye-hand coordination. [ABSTRACT FROM AUTHOR]

Kinematic measures of children's reaching were found to reflect stable differences in skill level for planning for future actions. Thirty-five toddlers (18-21 months) were engaged in building block towers (precise task) and in placing blocks into an open container (imprecise task). Sixteen children were retested on the same tasks a year later. Longer deceleration as the hand approached the block for pickup was found in the tower task compared with the imprecise task, indicating planning for the second movement. More skillful toddlers who could build high towers had a longer deceleration phase when placing blocks on the tower than toddlers who built low towers. Kinematic differences between the groups remained a year later when all children could build high towers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the performance of children with visual impairments (VI) aged 7 to 10 years on different types of motor skills. Furthermore, the association between the degree of the VI and motor performance was examined. The motor performance of 48 children with VI (32 males, 16 females; mean age 8y 10mo [SD 1y 1mo]) was assessed using the Movement Assessment Battery for Children (MABC). Their performance was compared with 48 children without VI (33 males, 15 females; mean age 8y 9mo [SD 1y 1mo]). Children with VI showed the poorest performance compared with peers without VI on unimanual speed, eye-hand coordination, catching, static balance, and dynamic balance while moving slowly. There was no significant difference between children with moderate and severe VI, except for bimanual coordination in 7- to 8-year-olds and eye-hand coordination in both the 7- to 8-year-olds and 9- to 10-year-olds, favouring the children with moderate VI. The poor performance compared with children without VI is related to vision, but the degree of the VI does not appear to relate to motor performance, except when associated with bimanual and eye-hand coordination. For children with VI, it seems very important to adjust the environmental context and task to enhance motor performance. [ABSTRACT FROM AUTHOR]

The article describes the development and ergonomic evaluation of an augmented reality (AR) welding helmet. The system provides an augmented user interface with supporting information relevant to the welding process. The experimental studies focused on hand–eye coordination of welders and nonwelders with two prototypes of the augmented reality welding helmet. The first prototype operated at 16 frames per second, whereas the second, improved version had 20 frames per second. In addition, the hand–eye coordination while wearing the welding helmet with video see-through head-mounted display was compared to a performance with natural vision, without any helmet. Experimental results showed significant influence of helmet and occupation on hand–eye coordination. Subjective assessment revealed better rating for stereo perception for the system with the higher frame rate, whereas no significant difference in performance was found between the two frame rates. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 317–330, 2007. [ABSTRACT FROM AUTHOR]

In the past it has often been assumed that the cortical networks for visually guided movement are the same for males and females. Here we use functional magnetic resonance imaging (fMRI) to show significant sex-related differences in human brain activity during visual-to-motor transformation tasks. Although the behavioural performance of the male and female groups did not differ, sex-related differences in levels of blood oxygen level-dependent fMRI activity are apparent in several cortical areas that have previously been demonstrated to be important for visually guided movements. These areas include the primary sensorimotor, dorsal premotor, superior parietal and lateral sulcus regions. Furthermore, the data indicate that the nature of these sex differences depends on the spatial mapping between a visual cue and the motor response that it guides. [ABSTRACT FROM AUTHOR]

Background Shifting gaze and attention ahead of the hand is a natural component in the performance of skilled manual actions. Very few studies have examined the precise co-ordination between the eye and hand in children with Developmental Coordination Disorder (DCD). Methods This study directly assessed the maturity of eye–hand co-ordination in children with DCD. A double-step pointing task was used to investigate the coupling of the eye and hand in 7-year-old children with and without DCD. Sequential targets were presented on a computer screen, and eye and hand movements were recorded simultaneously. Results There were no differences between typically developing (TD) and DCD groups when completing fast single-target tasks. There were very few differences in the completion of the first movement in the double-step tasks, but differences did occur during the second sequential movement. One factor appeared to be the propensity for the DCD children to delay their hand movement until some period after the eye had landed on the target. This resulted in a marked increase in eye–hand lead during the second movement, disrupting the close coupling and leading to a slower and less accurate hand movement among children with DCD. Conclusions In contrast to skilled adults, both groups of children preferred to foveate the target prior to initiating a hand movement if time allowed. The TD children, however, were more able to reduce this foveation period and shift towards a feedforward mode of control for hand movements. The children with DCD persevered with a look-then-move strategy, which led to an increase in error. For the group of DCD children in this study, there was no evidence of a problem in speed or accuracy of simple movements, but there was a difficulty in concatenating the sequential shifts of gaze and hand required for the completion of everyday tasks or typical assessment items. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate cognitive development at the onset of West syndrome (WS) with regard to electroencephalogram (EEG) patterns and visual function. Twenty-five patients (14 males, 11 females) at the onset of spasms (T0) in WS and 2 months later (T1) underwent a full clinical evaluation, including neuroimaging, cognitive assessment, video-EEG, and visual function. Mean age of the patients at spasm onset was 5.9 months (SD 2.5; range 2 to 13mo). Cognitive development, assessed with Griffiths Mental Development Scales (GMDS), was generally impaired at T0 and was significantly related to visual function (p<0.001) at both T0 and T1. In general, there was a specific major impairment in the eye–hand coordination scale of the GMDS which tended to disappear after 2 months in less severe cases. At the onset of spasms, sleep EEG organization seemed to be better related to cognitive abilities than awake hypsarrhythmia. These results support a close link between visual function and cognitive competence in WS and provide additional information to improve the understanding of possible mechanisms underlying cognitive impairment. [ABSTRACT FROM AUTHOR]

The Developmental Test of Visual–Motor Integration (VMI) is commonly used to assess handwriting dysfunction in children. The relationship between handwriting and underlying abilities as measured by the VMI, beyond the writing readiness stage, is unclear. The present study examined the ability of the VMI to discriminate between children with and without handwriting dysfunction.As part of a larger research study, 35 children with handwriting dysfunction from grades 4–6 (as identified by their teachers) and 35 children without handwriting dysfunction were assessed with the VMI.The VMI correctly identified only a small number of the children with handwriting dysfunction (sensitivity, 34%).The authors caution against the routine use of the VMI to assess older school-aged children with handwriting dysfunction. Use of a model of practice and clinical reasoning is recommended to guide the assessment of children with handwriting dysfunction. [ABSTRACT FROM AUTHOR]

Presents psychology-related abstracts. Gaining and sharing information about national and international psychology; Use of psychological tests in the Philippines; Hand-eye dominance and brain electrical asymmetries.

We sought to determine whether laterality is related to interhemispheric transfer and bimanual coordination during development. Children between 3 and 8 years of age were observed. In the first part of the experiment, we devised a continuous index to order the subjects according to their laterality. The laterality index included evaluation of hand and eye preference, and the right–left performance difference. In the second part of the experiment, we used this single index to determine whether laterality is related to interhemispheric transfer and bimanual coordination. Interhemispheric transfer was assessed by means of two tactile transfer tasks and one visuo–manual transfer task. We assessed bimanual coordination using the tapping task and the bimanual crank-rotation task. Results showed that right- and left-hand writers overlap on certain measures of laterality. They confirmed the improvement of interhemispheric transfer at around age 5 years, earlier progress in bimanual coordination with mirror than with parallel movements, and the existence of a relationship between visuo–manual interhemispheric transfer and bimanual coordination. The laterality index was not related to interhemispheric transfer, but it was related to the younger subjects' performance on the bimanual crank-rotation task: the less right handed, the better the bimanual coordination. In addition, on the same bimanual task, crossed hand–eye laterality was associated with better performance. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 43: 44–56, 2003. [ABSTRACT FROM AUTHOR]

Objective To assess an inanimate laboratory technique to improve hand— eye coordination in laparoscopy. Subjects 12 members of the medical staff at the Royal Hospital for Women, Sydney, were stratified into three groups: (1) young with no previous laparoscopic experience, i.e. first-year resident; (2) young with some previous experience, i.e. registrar, and (3) mature with extensive experience in operative laparoscopy, i.e. established surgeon. Methods A planned, sequentially more difficult programme of hand—eye coordination exercises using a pelvi-trainer was established. Performance was measured by recording the time taken for each subject to successfully and accurately complete each exercise. Results All subjects showed an improved performance in completing the described exercises. Group 1, showed the most improvement. Group 3 showed the least improvement but demonstrated the best performance. All groups demonstrated a similar performance by the end of the course. Conclusion The pelvi-trainer in conjunction with a structured series of exercises appears to allow a trainee to improve hand—eye coordination significantly. Considering that the same equipment is used as that in the operating theatre, it is reasonable to expect similar improvement in actual surgery. [ABSTRACT FROM AUTHOR]

Examines the effects of experimentally induced minor illnesses on the efficiency of human performance. Reasons for the lack of research on the behavioral effects of minor illnesses; Effects of influenza on the ability to detect and respond quickly to stimuli appearing at irregular intervals; Effects of colds on hand-eye coordination.

This describes a new scheme for eye-hand cooperation in which an active camera is introduced to guide object manipulations via a robot. By introducing an active camera controlled by the visual feedback approach, the observation conditions such as viewpoint, field of view, and resolution that cannot be maintained to satisfy a give task by using a conventional fixed camera, can reach an ideal state that is pre-defined by the given tasks. Since the desired observation condition can be changed freely, it becomes possible to replace motion control in three-dimensional space by two-dimensional visual feedback control, and the realization of a flexible control system for robots that performs qualitative motions such as moving in the direction pointing to the goal, also becomes possible. [ABSTRACT FROM AUTHOR]

Timing and direction of movement of the arms and hands of 7- and 11-month-old infants were examined during bimanual reaching for a transparent cube. Videotape analysis of frames from release of the hands to initial contact of one hand with the cube revealed that hand movement was more often temporarily linked for 7-month infants than for 11-month infants. Also, at 7 months, the hands moved toward the cube in the same direction, whereas at 11 months, they moved in opposite (complementary) directions. Thus, although both 7- and 11-month infants perform bimanual reaching, at 7 months the 2 hands are linked both in timing and direction of movement in a fashion different than at 11 months. [ABSTRACT FROM AUTHOR]

To test whether newborn babies take account of external forces in moving their limbs, spontaneous arm-waving movements were measured while the baby lay supine with its head turned to one side. Free-hanging weights, attached to each wrist by strings passing over pulleys, pulled on the arms in the direction of the toes. The results showed the babies applied compensatory forces to keep the hand they faced moving in the same region. In contrast, the (invisible) contra-lateral hand was pulled down by the weights. In a second experiment, where the arms were occluded, both arms were pulled down, suggesting that sight of the arm was necessary in compensating for the weight. In a third, conclusive experiment the babies viewed the arm they were not facing on a small video-monitor and this time the babies kept the visible contra-lateral hand up despite the weights. The results challenge the general view that spontaneous arm movements of neonates are purposeless and either reflexive or due to spontaneous patterned efference to the muscles. Instead, the findings suggest that in waving their arms, neonates are developing visual control of reaching. [ABSTRACT FROM AUTHOR]

Factorial analyses of various eye-hand coordination tasks were computed by age and sex for longitudinal data from ages 4&fract;12 through 8&fract;12. The results indicated a reduction from 3 to 2 factors between 4&fract;12 and 5&fract;12 years for females and between 5&fract;12 and 6&fract;12 for males. These factors were tentatively identified as patterning and speed. Increases in performance means and decreases in standard deviations occurred with increasing age for both sexes. Generally, sex differences were nonsignificant. Theoretical models of skilled action development are discussed, with the results tending to support a construct standards model. [ABSTRACT FROM AUTHOR]

Realistic work sample tests that were miniature replicas of the criterion task were classified as motor or verbal. The motor work sample had subjects physically manipulate things as tracing a complex electrical circuit or operating a sewing machine, while verbal work samples required individuals to cope with peopleoriented or language-oriented problems. From the literature, the work sample tests selected were those especially designed to represent on-the-job criterion behavior in a specific situation rather than ready-made standardized test's unless the latter had an unmistakable surface relationship to the criterion. The guiding hypothesis was a point-to-point theory which states that the more features in common between the predictor and criterion space, the higher the validity. In a previous review (Asher, 1972), it was found that historical information from the scorable application blank was data with a point-to-point relationship with the criterion and had the highest predictive power from a list of standard predictors including intelligence, personality, interest, perception, motor skill, and mechanical ability. Complex work sample tests that were miniature replicas of specific criterion behavior should also have a point-to-point relationship with the criterion. The results were as follows: 1. When job proficiency was the criterion, realistic motor work sample tests had the highest validity coefficients second only to biographical information. Verbal work sample tests were not as high as the motor, but they were in the top half of the predictors. 2. When the criterion was success in training, verbal work sample tests were more powerful in predicting success in training than in forecasting job proficiency. Verbal work sample tests had substantially more significant validity coefficients than the motor when there was a training criterion. The point-to-point theory does not preclude other possible explanations such as the interaction hypothesis, the work-methods hypothesis, and the transfer-of-experience hypothesis. [ABSTRACT FROM AUTHOR]

Compares the performance of negro and white children on a vocabulary test and an eye-hand coordination test. Environmental influences on the performance of children; Similarity in the growth curves for word knowledge; Absence of statistically reliable difference between negro and white children.

Presents the report of tests which were a part of a program conducted to assess the correlation between eye, hand, and foot coordination in children. Materials used in the test; Procedure used for determining the correspondence of the three body parts; Observations of various researchers regarding the impact of visual acuity on correspondence levels; Main conclusions that were from the study.

Focuses on an aiming test conducted for an analytical study of factors involved in the hand and eye coordination in children which affects their motor ability. Concepts used in experiments conducted by various researchers visual acuity; Apparatus and method used in the experiment conducted to observe hand and eye coordination; Variations included in the program; Analysis of variations in experiment results.

Discusses an experiment conducted on children to determine the importance of eye and hand co-ordination in the act of perception. Details of cards shown to the children in the experiment; Description of the stimulus apparatus used for measuring eye and hand movements; Indications given by a comparison of the movements before and after practice; Possible shortcomings of the experiment.

This study reports the relation between perceptual-motor functioning and hand-eye dominance on 237 female and 216 male Negro 48-month-old Ss. Performances of Ss falling into five hand-eye-dominance categories were compared on two perceptual-motor tasks and Stanford-Binet IQ. Results showed that left-hand-left, eye-dominant Ss gave significantly poorer performances on perceptual-motor and intellectual measures than all other hand-eye-dominant Ss except left-hand-right-eye-dominant Ss. There were no significant differences among comparisons of other hand-eye-dominance groups on these measures. Since the present investigation represents a relatively new approach to sinistrality, there is no direct empirical evidence for comparison; however, support was obtained for a previous study finding left-hand-left-eye-dominant Ss deficient in intellectual functioning. Although expressions of hand-eye dominance appear to be under neurological control, the underlying mechanism seems obscure. A neurological frame of reference is proposed, and further research on etiological factors is suggested. [ABSTRACT FROM AUTHOR]

In this article the authors discuss the use of gaze training to develop basic hand-eye coordination skills for laparoscopic surgery. The authors are critical on the four conditions that need to be met first for gaze training to be a practical solution. Also investigated are the theoretical frameworks and developments in the motor learning literature which may provide educators with important guidelines to develop surgical training curricula.

The article comments on the study "High-precision voluntary movements are largely independent from preceding vertex potentials elicited by sudden sensory events" by M. Kilintari and others in the current issue. Topics include the results showing that a larger vertex wave, evoked immediately before movement onset, leads to faster and more accurate visuomotor control, and salience increases the vertex wave and can increase motor performance.

The article examines effectiveness of 3-D reconstructed image rotation in handeye coordination using box-trainer materials as per Fundamentals of Endoscopic Surgery manual approved by Tokyo Medical and Dental University ethics committee. An imaging converter was created which can generate 3-D processed images in real-time from conventional two dimensional endoscopic images.

In extant primates, the posterior parietal cortex is involved in visuospatial integration, attention, and eye‐hand coordination, which are crucial functions for foraging and feeding behaviors. Paleoneurology studies brain evolution through the analysis of endocasts, that is molds of the inner surface of the braincase. These may preserve imprints of cortical structures, such as sulci, which might be of interest for locating the boundaries of major cortical regions. Old World monkeys (Cercopithecidae) represent an interesting zoological group for evolutionary studies, because of their diverse ecologies and locomotor behaviors. In this study, we quantify parietal lobe variation within the cercopithecid family, in a sample of 30 endocasts including 11 genera and 17 species, by combining landmark‐based and landmark‐free geometric morphometric analyses. More specifically, we quantitatively assess variation of the parietal proportions based on landmarks placed on reliable anatomical references and of parietal lobe surface morphology through deformation‐based methods. The main feature associated with the cercopithecid endocranial variation regards the inverse proportions of parietal and occipital lobes, with colobines, Theropithecus, and Papio displaying relatively larger parietal lobes and smaller occipital lobes compared with cercopithecins. The parietal surface is anteroposteriorly longer and mediolaterally flatter in colobines, while longitudinally shorter but laterally bulging in baboons. Large parietal lobes in colobines and baboons are likely to be independent evolutionary traits, and not necessarily associated with analogous functions or morphogenetic mechanisms. HIGHLIGHTS: Sulcal imprints on the surface of cercopithecid endocranial casts have shown differences between the two subfamilies, cercopithecinae and colobinae. Landmark‐based analysis allowed a quantification of these differences, confirming colobines have proportionately larger parietal lobes. Theropithecus and Papio display colobine‐like proportions. Colobuses and baboons evolved a larger parietal cortex through distinct mechanisms. [ABSTRACT FROM AUTHOR]