Virtual environments for motor rehabilitation: review.

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

Visuomotor perception in children with attention deficit hyperactivity disorder--combined type.

Children with Attention Deficit Hyperactivity Disorder--Combined Type (ADHD-CT) defined by behavioral characteristics of inattention, impulsivity, and hyperactivity including weaknesses in fine motor coordination and poor motor inhibition frequently exhibit poor handwriting and penmanship. Performance of children on visuomotor tasks is further complicated, as most studies have not excluded children with specific learning disabilities who are known to do poorly on these tests. This study was designed to examine the performance of children diagnosed with this disorder, without learning disabilities on visuomotor tasks. 26 preadolescent patients were administered a battery of tests that included the Bender-Gestalt, Conners' Parent Rating Scale, Continuous Performance Task, and Wide Range Achievement Test-Third Edition Scores on the Bender-Gestalt test averaged significantly lower than Koppitz normative data. This study lends support to the hypothesis that ADHD-CT children without learning disabilities exhibit deficits on tasks requiring visuomotor perception.     

Baby steps: investigating the development of perceptual–motor couplings in infancy

There are cells in our motor cortex that fire both when we perform and when we observe similar actions. It has been suggested that these perceptual‐motor couplings in the brain develop through associative learning during correlated sensorimotor experience. Although studies with adult participants have provided support for this hypothesis, there is no direct evidence that associative learning also underlies the initial formation of perceptual–motor couplings in the developing brain. With the present study we addressed this question by manipulating infants’ opportunities to associate the visual and motor representation of a novel action, and by investigating how this influenced their sensorimotor cortex activation when they observed this action performed by others. Pre‐walking 7–9‐month‐old infants performed stepping movements on an infant treadmill while they either observed their own real‐time leg movements (Contingent group) or the previously recorded leg movements of another infant (Non‐contingent control group). Infants in a second control group did not perform any steps and only received visual experience with the stepping actions. Before and after the training period we measured infants’ sensorimotor alpha suppression, as an index of sensorimotor cortex activation, while they watched videos of other infants’ stepping actions. While we did not find greater sensorimotor alpha suppression following training in the Contingent group as a whole, we nevertheless found that the strength of the visuomotor contingency experienced during training predicted the amount of sensorimotor alpha suppression at post‐test in this group. We did not find any effects of motor experience alone. These results suggest that the development of perceptual–motor couplings in the infant brain is likely to be supported by associative learning during correlated visuomotor experience.     

The beneficial effect of synchronized action on motor and perceptual timing in children

We examined the role of action in motor and perceptual timing across development. Adults and children aged 5 or 8 years old learned the duration of a rhythmic interval with or without concurrent action. We compared the effects of sensorimotor versus visual learning on subsequent timing behaviour in three different tasks: rhythm reproduction (Experiment 1), rhythm discrimination (Experiment 2) and interval discrimination (Experiment 3). Sensorimotor learning consisted of sensorimotor synchronization (tapping) to an isochronous visual rhythmic stimulus (ISI = 800 ms), whereas visual learning consisted of simply observing this rhythmic stimulus. Results confirmed our hypothesis that synchronized action during learning systematically benefitted subsequent timing performance, particularly for younger children. Action‐related improvements in accuracy were observed for both motor and perceptual timing in 5 years olds and for perceptual timing in the two older age groups. Benefits on perceptual timing tasks indicate that action shapes the cognitive representation of interval duration. Moreover, correlations with neuropsychological scores indicated that while timing performance in the visual learning condition depended on motor and memory capacity, sensorimotor learning facilitated an accurate representation of time independently of individual differences in motor and memory skill. Overall, our findings support the idea that action helps children to construct an independent and flexible representation of time, which leads to coupled sensorimotor coding for action and time.     

Motor sequence learning and reading ability: is poor reading associated with sequencing deficits?

Although it is widely assumed that children with learning disabilities have "sequencing problems," these have not been well specified. A non-verbal serial reaction time (SRT) paradigm was used to evaluate motor sequence learning in 422 children between ages 7 and 11 in relation to reading, cognitive ability level, and attention problems. The children demonstrated the response profile typically associated with motor sequence learning, but the component of the profile indicative of implicit sequence learning was not reliably associated with any of the predictors. Cognitive ability predicted overall response time; cognitive ability, reading, and attention problems each predicted overall accuracy. Explicit learning was predicted by cognitive ability, but not by reading or attention problems. Thus, we found no evidence that poor reading is preferentially associated with a domain general deficit in sequential learning.     

Use of an ecologically based program for teaching motor skills in a naturalistic setting to individuals with disabilities

The purpose of this action study was to apply an ecological program for teaching motor skills to individuals with disabilities in naturalistic settings. The program was developed based on an ecological survey. Participants were 22 individuals with disabilities, ages 7 to 26 years in the Fall of 1998 and 18 individuals with disabilities, ages 7 to 24 in the Winter of 1999. In each semester, a participant received one or two 50-min, training session(s) per week for 10 weeks. The number of steps in a motor-activity task performed correctly by a participant was measured in the first and last sessions in each semester. The magnitude of increase in the motor performance by participants and answers to questions in a short survey by participants' parents were used to describe the group performance. Analysis showed group performance of targeted motor skills could be improved using this ecological program in this local learning lab for special physical education.     

Are there pre-existing neural, cognitive, or motoric markers for musical ability?

Adult musician's brains show structural enlargements, but it is not known whether these are inborn or a consequence of long-term training. In addition, music training in childhood has been shown to have positive effects on visual-spatial and verbal outcomes. However, it is not known whether pre-existing advantages in these skills are found in children who choose to study a musical instrument nor is it known whether there are pre-existing associations between music and any of these outcome measures that could help explain the training effects. To answer these questions, we compared 5- to 7-year-olds beginning piano or string lessons (n=39) with 5- to 7-year-olds not beginning instrumental training (n=31). All children received a series of tests (visual-spatial, non-verbal reasoning, verbal, motor, and musical) and underwent magnetic resonance imaging. We found no pre-existing neural, cognitive, motor, or musical differences between groups and no correlations (after correction for multiple analyses) between music perceptual skills and any brain or visual-spatial measures. However, correlations were found between music perceptual skills and both non-verbal reasoning and phonemic awareness. Such pre-existing correlations suggest similarities in auditory and visual pattern recognition as well a sharing of the neural substrates for language and music processing, most likely due to innate abilities or implicit learning during early development. This baseline study lays the groundwork for an ongoing longitudinal study addressing the effects of intensive musical training on brain and cognitive development, and making it possible to look retroactively at the brain and cognitive development of those children who emerge showing exceptional musical talent.     

DIAGNOSTIC PSYCHOLOGICAL TESTING FOR READING/LEARNING DISORDERS IN PRESCHOOL CHILDREN

ABSTRACT

The assessment of preschool children who are at risk for having specific language/learning disorders when they enter school is a complex undertaking which must involve examining a wide variety of developmental processes. In addition to a thorough medical, developmental and academic history, the clinician should obtain data regarding perceptual‐motor functioning, language and cognitive development, nominal recall, cerebral dominance and directionality, sequential memory, and the integrity of basic sensory modalities. Although the diagnosis of potential learning disorders in preschool children 1s difficult because of the variability in developmental rate of young children, a systematic evaluation of the developmental functions which are classically associated with learning disabilities allows the psychologist to make a responsible and generally accurate statement of the child's current functioning and future potential     

Use of the dichotic listening technique with learning disabilities

Dichotic listening (DL) techniques have been used extensively as a non-invasive procedure to assess language lateralization among children with and without learning disabilities (LD), and with individuals who have other auditory system related brain disorders. Results of studies using DL have indicated that language is lateralized in children with LD and that the lateralized language asymmetries do not develop after age 6 nor are they affected by gender. Observed differences in lateralized language processes between control children and those with LD were found not due to delayed cerebral dominance, but rather to deficits in selective attention. In addition, attention factors have a greater influence on auditory processing of verbal than nonverbal stimuli for children with LD, and children with LD exhibit a general processing bias to the same hemisphere unlike control children. Furthermore, employing directed attention conditions in DL experiments has played an important role in explaining learning disabled children's performance on DL tasks. We conclude that auditory perceptual asymmetries as assessed by DL with children who experience LD are the result of the interaction of hemispheric capability and attention factors.     

Implicit visual learning and the expression of learning

Although the existence of implicit motor learning is now widely accepted, the findings concerning perceptual implicit learning are ambiguous. Some researchers have observed perceptual learning whereas other authors have not. The review of the literature provides different reasons to explain this ambiguous picture, such as differences in the underlying learning processes, selective attention, or differences in the difficulty to express this knowledge. In three experiments, we investigated implicit visual learning within the original serial reaction time task. We used different response devices (keyboard vs. mouse) in order to manipulate selective attention towards response dimensions. Results showed that visual and motor sequence learning differed in terms of RT-benefits, but not in terms of the amount of knowledge assessed after training. Furthermore, visual sequence learning was modulated by selective attention. However, the findings of all three experiments suggest that selective attention did not alter implicit but rather explicit learning processes.     

Discrimination training of phonemic contrasts enhances phonological processing in mainstream school children

Auditory perceptual learning has been proposed as effective for remediating impaired language and for enhancing normal language development. We examined the effect of phonemic contrast discrimination training on the discrimination of whole words and on phonological awareness in 8- to 10-year-old mainstream school children. Eleven phonemic contrast continua were synthesised using linear interpolation coding from real speaker endpoints. Thirty children were pre-tested on the Word Discrimination Test (WDT) and the Phonological Assessment Battery (PhAB). Eighteen then trained for 12 x 30min sessions over 4 weeks using an adaptive three interval two alternative phonemic matching task. The remaining children participated in regular classroom activities. In Post-testing, trained children significantly increased their age-equivalent scores on both the WDT and PhAB by about 2 years. For the PhAB, no improvement was found in the controls. Enhanced performance in the trained children was maintained in a delayed test 5-6 weeks following training. Enhancements on the trained discriminations were weak and variable. The results indicate a dramatic improvement in phonological awareness following phonemic discrimination training without matching perceptual learning.     

Genetics and educational psychology

Background: Molecular genetics, one of the most energetic and exciting areas of science, is slowly but surely coming to educational psychology. Aims: We review recent molecular genetic research on learning disabilities as a sign of things to come in educational psychology. We also consider some misconceptions about genetics that have slowed the acceptance of genetics in educational psychology. Samples: Diverse samples of children with learning disabilities have been studied, primarily in the UK and the USA. Methods: Linkage analysis can detect genes that have large effects on learning disabilities. Association analysis can detect genes of much smaller effect size, which is important because common disorders such as learning disabilities are likely to be influenced by many genes as well as by many environmental factors. Results: For reading disability, replicated linkages have been identified on chromosomes 6, 15 and 18. A gene responsible for a rare type of language impairment has recently been identified. For common language impairment, linkages on chromosomes 16 and 19 have recently been reported. More than 200 genetic disorders, most extremely rare, include mental retardation among their symptoms, and chromosomal abnormalities are a major cause of mental retardation. Conclusions: Although finding specific genes associated with learning disabilities is unlikely to have much of a direct application for teachers in the classroom, such findings will have far‐reaching implications for diagnosis, treatment and prevention of learning disabilities and for research in educational psychology. Educational psychology has been slower to accept evidence for the importance of genetics than other areas of psychology in part because of misconceptions about what it means to say that genetics is important for common complex disorders such as learning disabilities.     

Visual perceptual learning

Perceptual learning refers to the phenomenon that practice or training in perceptual tasks often substantially improves perceptual performance. Often exhibiting stimulus or task specificities, perceptual learning differs from learning in the cognitive or motor domains. Research on perceptual learning reveals important plasticity in adult perceptual systems, and as well as the limitations in the information processing of the human observer. In this article, we review the behavioral results, mechanisms, physiological basis, computational models, and applications of visual perceptual learning.     

周边视觉的知觉学习

知觉学习是指知觉能力随着知觉训练或经验逐渐改变的现象。它具有特异性-迁移性,可以根据时程划分为快速学习和慢速学习。知觉学习意味着与知觉直接对应的脑区神经元激活方式的变化,并且与注意有着一定的联系。目前周边视觉的知觉学习研究已有一些成果：对于非语词刺激,随着练习,判断目标刺激（例如刺激朝向、游标视敏度）的能力,有很大的提升;对于语词刺激,周边视觉的知觉学习可以帮助提高阅读速度。可以通过提高视觉广度来提高周边视觉的阅读速度。周边视觉的知觉学习还有着重大应用价值,可以帮助中央凹视觉缺损的人们提高周边视觉能力,帮助恢复阅读能力。     

Oculomotor behavior and the level of repetition in motor practice: Effects on pupil dilation,eyeblinks and visual scanning

The benefits of less repetitive practice in motor learning have been explained by the increased demand for memory processes during the execution of motor skills. Recently, a new perspective associating increased demand for perception with less repetitive practice has also been proposed. Augmented information gathering and visual scanning characterize this higher perceptual demand. To extend our knowledge about mental effort and perceptual differences in practice organization, the association between oculomotor behavior and type of practice was investigated. We required participants to press four keys with different absolute and relative timing goals during the acquisition phase. An eye-tracker captured visual scanning of the skill’s absolute and relative information displayed on the screen. Participants were tested 24 h after acquisition by a retention and transfer test. A higher level of both pupil dilation and amount of eyeblinks indicated an increased mental effort in less repetitive practice compared to more repetitive practice. Visual scanning of the skill’s relative and absolute information was specific to the type of practice. The findings indicate many differences in oculomotor behavior associated with the practice schedule.     

Fine motor deficiencies in children with developmental coordination disorder and learning disabilities: an underlying open-loop control deficit

Thirty-two children with Developmental Coordination Disorder (DCD) and learning disabilities (LD) and their age-matched controls attending normal primary schools were investigated using kinematic movement analysis of fine-motor performance. Three hypotheses about the nature of the motor deficits observed in children with LD were tested: general slowness hypothesis, limited information capacity hypothesis, and the motor control mode hypothesis. Measures of drawing movements were analyzed under different task conditions using a Fitts' paradigm. In a reciprocal aiming task, the children drew straight-line segments between two targets 2.5 cm apart. Three Target Sizes were used (0.22, 0.44, and 0.88 cm). Children used an electronic pen that left no trace on the writing tablet. To manipulate the degree of open-loop movement control, the aiming task was performed under two different control regimes: discrete aiming and cyclic aiming. The kinematic analysis of the writing movements of the 32 children with DCD/LD that took part in the experimental study confirmed that besides learning disabilities they have a motor learning problem as well. Overall, the two groups did not differ in response time, nor did they respond differently according to Fitts' Law. Both groups displayed a conventional trade-off between Target Size and average Movement Time. However, while movement errors for children with DCD/LD were minimal on the discrete task, they made significantly more errors on the cyclic task. This, together with faster endpoint velocities, suggests a reduced ability to use a control strategy that emphasizes the terminal control of accuracy. Taken together, the results suggest that children with DCD/LD rely more on feedback during movement execution and have difficulty switching to a feedforward or open-loop strategy.     

Training compliance control yields improved drawing in 5–11 year old children with motor difficulties

There are a large number of children with motor difficulties including those that have difficulty producing movements qualitatively well enough to improve in perceptuo-motor learning without intervention. We have developed a training method that supports active movement generation to allow improvement in a 3D tracing task requiring good compliance control. Previously, we tested a limited age range of children and found that training improved performance on the 3D tracing task and that the training transferred to a 2D drawing test. In the present study, school children (5–11 years old) with motor difficulties were trained in the 3D tracing task and transfer to a 2D drawing task was tested. We used a cross-over design where half of the children received training on the 3D tracing task during the first training period and the other half of the children received training during the second training period. Given previous results, we predicted that younger children would initially show reduced performance relative to the older children, and that performance at all ages would improve with training. We also predicted that training would transfer to the 2D drawing task. However, the pre-training performance of both younger and older children was equally poor. Nevertheless, post-training performance on the 3D task was dramatically improved for both age groups and the training transferred to the 2D drawing task. Overall, this work contributes to a growing body of literature that demonstrates relatively preserved motor learning in children with motor difficulties and further demonstrates the importance of games in therapeutic interventions.     

A methodology for assessing the functions of emerging speech in children with developmental disabilities

An approach based on Skinner's (1957) theory of verbal behavior has been developed to understand and teach elementary communication skills to children with autism and developmental disabilities (Sundberg & Partington, 1998). However, few studies have directly examined the characteristics of emerging language in children with developmental disabilities. The purpose of this study was to develop and evaluate an assessment for identifying the elementary functions of vocal speech in children. Participants were 4 children with developmental disabilities, aged 6 years to 12 years, who exhibited at least one distinguishable vocal response (word or phrase) frequently in the natural environment. The assessment focused on three verbal operants delineated by Skinner (mand, tact, and intraverbal). One or more functions were identified for at least one vocal response of each child. Results suggested that this assessment would be useful for (a) evaluating Skinner's theory, (b) guiding decisions about language training for individual children, and (c) studying the nature of expressive language development in children with developmental disabilities.     

Simplifying environmental cues in a Morris-type water maze improves place learning in old NMRI mice.

Old virgin female NMRI mice aged 17 months were compared with mice aged 3 months for their spatial learning abilities in two versions of the Morris water maze. The first one was a simplified version with a salient configuration of cues comparable to a black/white discrimination and the second one was the classical version of the Morris test with many distal cues surrounding the maze. In the simplified version, old mice presented a slower rate of acquisition and a transient poorer retention compared to young mice. However, old mice achieved a final level of performance statistically comparable to their young counterparts as assessed by latencies to escape onto the concealed platform and by the spatial bias measured in probe trials at intervals during testing. When subsequently subjected to classical Morris maze learning, the same old animals showed marked learning deficits and were persistently impaired in their latencies to escape onto the platform. They presented no spatial bias for the location of the platform in the different probe trials. When the goal was cued at the end of the experiment, the performances of old mice rapidly improved, showing that motivation, motor disabilities, or fatigue and ability to use proximal cues cannot explain the place learning deficit. Our results were discussed in terms of cognitive versus sensory/perceptual disabilities in aged rats and mice.     

Children with low motor ability have lower visual-motor integration ability but unaffected perceptual skills

The purpose of this study was to examine perceptual, visual-motor abilities and intellectual skills in children with low, average and above average motor abilities. The participants were 144 children (aged 6-10 years) attending elementary school. Three groups of children were identified on the basis of their performance at the TGMD (Test of Gross Motor Development; [Ulrich, D.A. (1985). TGMD, Test of Gross Motor Development. Austin, Texas: PRO-ED. Edizione Italiana a cura di D. Ianes, TEST TGM. Test di valutazione delle abilita grosso-motorie. 1994, Trento: Edizioni Centro Studi Erickson]). Each child received an intelligence test (K-BIT; [Kaufman, A.S., & Kaufman, N.L. (1990). K-BIT. Kaufman Brief Intelligence Test. Circle Pines, MN: American Guidance Service]) and was evaluated for perceptual and visual-motor integration abilities (DTVP; [Hammill, D.D., Pearson, N.A., & Voress, J.K. (1993). Developmental Test of Visual Perception (2nd ed.). Austin, Texas: PRO-ED. Edizione Italiana a cura di D. Ianes, TEST TPV. Test di percezione visiva e integrazione visuo-motoria. Trento: Edizioni Centro Studi Erickson]). Results highlight a significant difference in visual-motor integration between children with high and low gross-motor abilities, in the absence of significant differences in perceptual skills or intellectual ability. The findings are discussed with reference to the concept of atypical brain development [Gilger, J.W., & Kaplan, B.J. (2001). Atypical brain development: A conceptual framework for understanding developmental learning disabilities. Developmental Neuropsychology, 20, 465].