WorldWideScience

Sample records for added motor imagery

  1. Organizing motor imageries.

    Science.gov (United States)

    Hanakawa, Takashi

    2016-03-01

    Over the last few decades, motor imagery has attracted the attention of researchers as a prototypical example of 'embodied cognition' and also as a basis for neuro-rehabilitation and brain-machine interfaces. The current definition of motor imagery is widely accepted, but it is important to note that various abilities rather than a single cognitive entity are dealt with under a single term. Here, motor imagery has been characterized based on four factors: (1) motor control, (2) explicitness, (3) sensory modalities, and (4) agency. Sorting out these factors characterizing motor imagery may explain some discrepancies and variability in the findings from previous studies and will help to optimize a study design in accordance with the purpose of each study in the future. PMID:26602980

  2. The functional alterations associated with motor imagery training: a comparison between motor execution and motor imagery of sequential finger tapping

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    Zhang, Hang; Yao, Li; Long, Zhiying

    2011-03-01

    Motor imagery training, as an effective strategy, has been more and more applied to mental disorders rehabilitation and motor skill learning. Studies on the neural mechanism underlying motor imagery have suggested that such effectiveness may be related to the functional congruence between motor execution and motor imagery. However, as compared to the studies on motor imagery, the studies on motor imagery training are much fewer. The functional alterations associated with motor imagery training and the effectiveness of motor imagery training on motor performance improvement still needs further investigation. Using fMRI, we employed a sequential finger tapping paradigm to explore the functional alterations associated with motor imagery training in both motor execution and motor imagery task. We hypothesized through 14 consecutive days motor imagery training, the motor performance could be improved and the functional congruence between motor execution and motor imagery would be sustained form pre-training phase to post-training phase. Our results confirmed the effectiveness of motor imagery training in improving motor performance and demonstrated in both pre and post-training phases, motor imagery and motor execution consistently sustained the congruence in functional neuroanatomy, including SMA (supplementary motor cortex), PMA (premotor area); M1( primary motor cortex) and cerebellum. Moreover, for both execution and imagery tasks, a similar functional alteration was observed in fusiform through motor imagery training. These findings provided an insight into the effectiveness of motor imagery training and suggested its potential therapeutic value in motor rehabilitation.

  3. Motor imagery development in primary school children.

    NARCIS (Netherlands)

    Caeyenberghs, K.; Tsoupas, J.; Wilson, P.H.; Smits-Engelsman, B.C.M.

    2009-01-01

    Motor imagery provides a unique window on the integrity of movement representation. How this ability unfolds during development remains unknown, however. It was the aim of this cross-sectional study to chart the development of movement imagery over childhood using validated measures, and to examine

  4. Classification of motor imagery performance in acute stroke

    NARCIS (Netherlands)

    Tangwiriyasakul, Chayanin; Mocioiu, V.; Putten, van M.J.A.M.; Rutten, W.L.C.

    2014-01-01

    Objective. Effective motor imagery performance, seen as strong suppression of the sensorimotor rhythm, is the key element in motor imagery therapy. Therefore, optimization of methods to classify whether the subject is performing the imagery task is a prerequisite. An optimal classification method sh

  5. Mental representation and motor imagery training.

    Science.gov (United States)

    Schack, Thomas; Essig, Kai; Frank, Cornelia; Koester, Dirk

    2014-01-01

    Research in sports, dance and rehabilitation has shown that basic action concepts (BACs) are fundamental building blocks of mental action representations. BACs are based on chunked body postures related to common functions for realizing action goals. In this paper, we outline issues in research methodology and an experimental method, the structural dimensional analysis of mental representation (SDA-M), to assess action-relevant representational structures that reflect the organization of BACs. The SDA-M reveals a strong relationship between cognitive representation and performance if complex actions are performed. We show how the SDA-M can improve motor imagery training and how it contributes to our understanding of coaching processes. The SDA-M capitalizes on the objective measurement of individual mental movement representations before training and the integration of these results into the motor imagery training. Such motor imagery training based on mental representations (MTMR) has been applied successfully in professional sports such as golf, volleyball, gymnastics, windsurfing, and recently in the rehabilitation of patients who have suffered a stroke. PMID:24904368

  6. Mental Representation and Motor Imagery Training

    Directory of Open Access Journals (Sweden)

    Thomas eSchack

    2014-05-01

    Full Text Available Research in sports, dance and rehabilitation has shown that Basic Action Concepts (BACs are fundamental building blocks of mental action representations. BACs are based on chunked body postures related to common functions for realizing action goals. In this paper, we outline issues in research methodology and an experimental method, SDA-M (structural dimensional analysis of mental representation, to assess action-relevant representational structures that reflect the organization of BACs. The SDA-M reveals a strong relationship between cognitive representation and performance if complex actions are performed. We show how the SDA-M can improve motor imagery training and how it contributes to our understanding of coaching processes. The SDA-M capitalizes on the objective measurement of individual mental movement representations before training and the integration of these results into the motor imagery training. Such motor imagery training based on mental representations has been applied successfully in professional sports such as golf, volleyball, gymnastics, windsurfing, and recently in the rehabilitation of patients who have suffered a stroke.

  7. Selective effect of physical fatigue on motor imagery accuracy.

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    Franck Di Rienzo

    Full Text Available While the use of motor imagery (the mental representation of an action without overt execution during actual training sessions is usually recommended, experimental studies examining the effect of physical fatigue on subsequent motor imagery performance are sparse and yielded divergent findings. Here, we investigated whether physical fatigue occurring during an intense sport training session affected motor imagery ability. Twelve swimmers (nine males, mean age 15.5 years conducted a 45 min physically-fatiguing protocol where they swam from 70% to 100% of their maximal aerobic speed. We tested motor imagery ability immediately before and after fatigue state. Participants randomly imagined performing a swim turn using internal and external visual imagery. Self-reports ratings, imagery times and electrodermal responses, an index of alertness from the autonomic nervous system, were the dependent variables. Self-reports ratings indicated that participants did not encounter difficulty when performing motor imagery after fatigue. However, motor imagery times were significantly shortened during posttest compared to both pretest and actual turn times, thus indicating reduced timing accuracy. Looking at the selective effect of physical fatigue on external visual imagery did not reveal any difference before and after fatigue, whereas significantly shorter imagined times and electrodermal responses (respectively 15% and 48% decrease, p<0.001 were observed during the posttest for internal visual imagery. A significant correlation (r=0.64; p<0.05 was observed between motor imagery vividness (estimated through imagery questionnaire and autonomic responses during motor imagery after fatigue. These data support that unlike local muscle fatigue, physical fatigue occurring during intense sport training sessions is likely to affect motor imagery accuracy. These results might be explained by the updating of the internal representation of the motor sequence, due to

  8. Auditory and motor imagery modulate learning in music performance

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    Brown, Rachel M.; Palmer, Caroline

    2013-01-01

    Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians' encoding (during Learning, as they practiced novel melodies), and retrieval (during Recall of those melodies). Pianists learned melodies by listening without performing (auditory learning) or performing without sound (motor learning); following Learning, pianists performed the melodies from memory with auditory feedback (Recall). During either Learning (Experiment 1) or Recall (Experiment 2), pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced) and temporal regularity (variability of quarter-note interonset intervals) were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists' pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2). Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1): Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2): Higher auditory imagery skill predicted greater temporal regularity during Recall in the presence of

  9. Auditory and motor imagery modulate learning in music performance.

    Science.gov (United States)

    Brown, Rachel M; Palmer, Caroline

    2013-01-01

    Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians' encoding (during Learning, as they practiced novel melodies), and retrieval (during Recall of those melodies). Pianists learned melodies by listening without performing (auditory learning) or performing without sound (motor learning); following Learning, pianists performed the melodies from memory with auditory feedback (Recall). During either Learning (Experiment 1) or Recall (Experiment 2), pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced) and temporal regularity (variability of quarter-note interonset intervals) were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists' pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2). Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1): Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2): Higher auditory imagery skill predicted greater temporal regularity during Recall in the presence of

  10. 2012 Oconee County, Georgia ADS80 Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — All imagery was collected during the 2012 Spring flying season during leaf-off conditions for deciduous vegetation in the State of Georgia. The sun angle was at...

  11. Using Mental Imagery To Enhance Children's Motor Performance.

    Science.gov (United States)

    Short, Sandra E.; Afremow, James; Overby, Lynnette

    2001-01-01

    Students' motor performance can be enhanced through the use of mental imagery. This article presents nine ways that physical education teachers and coaches can use mental imagery to accomplish various outcomes. These include imagery for: learning, performing, focusing, self-confidence, motivation, arousal, changing negatives into positives,…

  12. Current insights in the development of children's motor imagery ability

    NARCIS (Netherlands)

    Spruijt, S.; Kamp, J. van der; Steenbergen, B.

    2015-01-01

    Over the last two decades, the number of studies on motor imagery in children has witnessed a large expansion. Most studies used the hand laterality judgment paradigm or the mental chronometry paradigm to examine motor imagery ability. The main objective of the current review is to collate these stu

  13. Current insights in the development of children's motor imagery ability.

    NARCIS (Netherlands)

    Spruijt, S.; Kamp, J. van der; Steenbergen, B.

    2015-01-01

    Over the last two decades, the number of studies on motor imagery in children has witnessed a large expansion. Most studies used the hand laterality judgment paradigm or the mental chronometry paradigm to examine motor imagery ability. The main objective of the current review is to collate these stu

  14. Auditory and motor imagery modulate learning in music performance

    Directory of Open Access Journals (Sweden)

    Rachel M. Brown

    2013-07-01

    Full Text Available Skilled performers such as athletes or musicians can improve their performance by imagining the actions or sensory outcomes associated with their skill. Performers vary widely in their auditory and motor imagery abilities, and these individual differences influence sensorimotor learning. It is unknown whether imagery abilities influence both memory encoding and retrieval. We examined how auditory and motor imagery abilities influence musicians’ encoding (during Learning, as they practiced novel melodies, and retrieval (during Recall of those melodies. Pianists learned melodies by listening without performing (auditory learning or performing without sound (motor learning; following Learning, pianists performed the melodies from memory with auditory feedback (Recall. During either Learning (Experiment 1 or Recall (Experiment 2, pianists experienced either auditory interference, motor interference, or no interference. Pitch accuracy (percentage of correct pitches produced and temporal regularity (variability of quarter-note interonset intervals were measured at Recall. Independent tests measured auditory and motor imagery skills. Pianists’ pitch accuracy was higher following auditory learning than following motor learning and lower in motor interference conditions (Experiments 1 and 2. Both auditory and motor imagery skills improved pitch accuracy overall. Auditory imagery skills modulated pitch accuracy encoding (Experiment 1: Higher auditory imagery skill corresponded to higher pitch accuracy following auditory learning with auditory or motor interference, and following motor learning with motor or no interference. These findings suggest that auditory imagery abilities decrease vulnerability to interference and compensate for missing auditory feedback at encoding. Auditory imagery skills also influenced temporal regularity at retrieval (Experiment 2: Higher auditory imagery skill predicted greater temporal regularity during Recall in the

  15. Bridging the gap between motor imagery and motor execution with a brain-robot interface.

    Science.gov (United States)

    Bauer, Robert; Fels, Meike; Vukelić, Mathias; Ziemann, Ulf; Gharabaghi, Alireza

    2015-03-01

    According to electrophysiological studies motor imagery and motor execution are associated with perturbations of brain oscillations over spatially similar cortical areas. By contrast, neuroimaging and lesion studies suggest that at least partially distinct cortical networks are involved in motor imagery and execution. We sought to further disentangle this relationship by studying the role of brain-robot interfaces in the context of motor imagery and motor execution networks. Twenty right-handed subjects performed several behavioral tasks as indicators for imagery and execution of movements of the left hand, i.e. kinesthetic imagery, visual imagery, visuomotor integration and tonic contraction. In addition, subjects performed motor imagery supported by haptic/proprioceptive feedback from a brain-robot-interface. Principal component analysis was applied to assess the relationship of these indicators. The respective cortical resting state networks in the α-range were investigated by electroencephalography using the phase slope index. We detected two distinct abilities and cortical networks underlying motor control: a motor imagery network connecting the left parietal and motor areas with the right prefrontal cortex and a motor execution network characterized by transmission from the left to right motor areas. We found that a brain-robot-interface might offer a way to bridge the gap between these networks, opening thereby a backdoor to the motor execution system. This knowledge might promote patient screening and may lead to novel treatment strategies, e.g. for the rehabilitation of hemiparesis after stroke.

  16. Motor imagery modulation of body sway is task-dependent and relies on imagery ability

    Directory of Open Access Journals (Sweden)

    Thiago eLemos

    2014-05-01

    Full Text Available AbstractIn this study we investigate to what extent the effects of motor imagery on postural sway are constrained by movement features and the subject’s imagery ability. Twenty-three subjects were asked to imagine three movements using the kinesthetic modality: rising on tiptoes, whole-body forward reaching, and whole-body lateral reaching. After each task, subjects reported the level of imagery vividness and were subsequently grouped into a HIGH group (scores ≥3, moderately intense imagery or a LOW group (scores ≤2, mildly intense imagery. An eyes closed trial was used as a control task. Center of gravity (COG coordinates were collected, along with surface EMG of the deltoid (medial and anterior portion and lateral gastrocnemius muscles. COG variability was quantified as the amount of fluctuations in position and velocity in the forward-backward and lateral directions. Changes in COG variability during motor imagery were observed only for the HIGH group. COG variability in the forward-backward direction was increased during the rising on tiptoes imagery, compared with the control task (p=0.01 and the lateral reaching imagery (p=0.02. Conversely, COG variability in the lateral direction was higher in rising on tiptoes and lateral reaching imagery than during the control task (p0.08 or task (p>0.46 for any of the tested muscles. In summary, motor imagery influences body sway dynamics in a task-dependent manner, and relies on the subject’ imagery ability.

  17. What Do Eye Gaze Metrics Tell Us about Motor Imagery?

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    Elodie Poiroux

    Full Text Available Many of the brain structures involved in performing real movements also have increased activity during imagined movements or during motor observation, and this could be the neural substrate underlying the effects of motor imagery in motor learning or motor rehabilitation. In the absence of any objective physiological method of measurement, it is currently impossible to be sure that the patient is indeed performing the task as instructed. Eye gaze recording during a motor imagery task could be a possible way to "spy" on the activity an individual is really engaged in. The aim of the present study was to compare the pattern of eye movement metrics during motor observation, visual and kinesthetic motor imagery (VI, KI, target fixation, and mental calculation. Twenty-two healthy subjects (16 females and 6 males, were required to perform tests in five conditions using imagery in the Box and Block Test tasks following the procedure described by Liepert et al. Eye movements were analysed by a non-invasive oculometric measure (SMI RED250 system. Two parameters describing gaze pattern were calculated: the index of ocular mobility (saccade duration over saccade + fixation duration and the number of midline crossings (i.e. the number of times the subjects gaze crossed the midline of the screen when performing the different tasks. Both parameters were significantly different between visual imagery and kinesthesic imagery, visual imagery and mental calculation, and visual imagery and target fixation. For the first time we were able to show that eye movement patterns are different during VI and KI tasks. Our results suggest gaze metric parameters could be used as an objective unobtrusive approach to assess engagement in a motor imagery task. Further studies should define how oculomotor parameters could be used as an indicator of the rehabilitation task a patient is engaged in.

  18. Adding Insult to Imagery? Art Education and Censorship

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    Sweeny, Robert W.

    2007-01-01

    The "Adding Insult to Imagery? Artistic Responses to Censorship and Mass-Media" exhibition opened in January 16, 2006, Kipp Gallery on the Indiana University of Pennsylvania campus. Eleven gallery-based works, 9 videos, and 10 web-based artworks comprised the show; each dealt with the relationship between censorship and mass mediated images. Many…

  19. Current insights in the development of children’s motor imagery ability

    Directory of Open Access Journals (Sweden)

    Steffie eSpruijt

    2015-06-01

    Full Text Available Over the last two decades, the number of studies on motor imagery in children has witnessed a large expansion. Most studies used the hand laterality judgment paradigm or the mental chronometry paradigm to examine motor imagery ability. The main objective of the current review is to collate these studies to provide a more comprehensive insight in children’s motor imagery development and its age of onset. Motor imagery is a form of motor cognition and aligns with forward (or predictive models of motor control. Studying age-related differences in motor imagery ability in children therefore provides insight in underlying processes of motor development during childhood. Another motivation for studying age-related differences in motor imagery is that in order to effectively apply motor imagery training in children (with motor impairments, it is pertinent to first establish the age at which children are actually able to perform motor imagery.Overall, performance in the imagery tasks develops between 5 and 12 years of age. The age of motor imagery onset, however, remains equivocal, as some studies indicate that children of 5 to 7 years old can already enlist motor imagery in an implicit motor imagery task, whereas other studies using explicit instructions revealed that children do not use motor imagery before the age of 10. From the findings of the current study, we can conclude that motor imagery training is potentially a feasible method for paediatric rehabilitation in children from 5 years on. We suggest that younger children are most likely to benefit from motor imagery training that is presented in an implicit way. Action observation training might be a beneficial adjunct to implicit motor imagery training. From 10 years of age, more explicit forms of motor imagery training can be effectively used.

  20. Enhancing voluntary imitation through attention and motor imagery.

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    Bek, Judith; Poliakoff, Ellen; Marshall, Hannah; Trueman, Sophie; Gowen, Emma

    2016-07-01

    Action observation activates brain areas involved in performing the same action and has been shown to increase motor learning, with potential implications for neurorehabilitation. Recent work indicates that the effects of action observation on movement can be increased by motor imagery or by directing attention to observed actions. In voluntary imitation, activation of the motor system during action observation is already increased. We therefore explored whether imitation could be further enhanced by imagery or attention. Healthy participants observed and then immediately imitated videos of human hand movement sequences, while movement kinematics were recorded. Two blocks of trials were completed, and after the first block participants were instructed to imagine performing the observed movement (Imagery group, N = 18) or attend closely to the characteristics of the movement (Attention group, N = 15), or received no further instructions (Control group, N = 17). Kinematics of the imitated movements were modulated by instructions, with both Imagery and Attention groups being closer in duration, peak velocity and amplitude to the observed model compared with controls. These findings show that both attention and motor imagery can increase the accuracy of imitation and have implications for motor learning and rehabilitation. Future work is required to understand the mechanisms by which these two strategies influence imitation accuracy. PMID:26892882

  1. The correlation between motor impairments and event-related desynchronization during motor imagery in ALS patients

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    Kasahara Takashi

    2012-06-01

    Full Text Available Abstract Background The event-related desynchronization (ERD in EEG is known to appear during motor imagery, and is thought to reflect cortical processing for motor preparation. The aim of this study is to examine the modulation of ERD with motor impairment in ALS patients. ERD during hand motor imagery was obtained from 8 ALS patients with a variety of motor impairments. ERD was also obtained from age-matched 11 healthy control subjects with the same motor task. The magnitude and frequency of ERD were compared between groups for characterization of ALS specific changes. Results The ERD of ALS patients were significantly smaller than those of control subjects. Bulbar function and ERD were negatively correlated in ALS patients. Motor function of the upper extremities did was uncorrelated with ERD. Conclusions ALS patients with worsened bulbar scales may show smaller ERD. Motor function of the upper extremities did was uncorrelated with ERD.

  2. Rehearsal strategies during motor-sequence learning in old age : Execution vs motor imagery

    NARCIS (Netherlands)

    Stoter, Arjan J. R.; Scherder, Erik J. A.; Kamsma, Yvo P. T.; Mulder, Theo

    2008-01-01

    Motor imagery and action-based rehearsal were compared during motor sequence-learning by young adults (M = 25 yr., SD = 3) and aged adults (M = 63 yr., SD = 7). General accuracy of aged adults was lower than that of young adults (F-1,F-28 = 7.37, p = .01) even though working-memory capacity was equi

  3. Best practice for motor imagery: a systematic literature review on motor imagery training elements in five different disciplines

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    Scheidhauer Anne

    2011-06-01

    Full Text Available Abstract Background The literature suggests a beneficial effect of motor imagery (MI if combined with physical practice, but detailed descriptions of MI training session (MITS elements and temporal parameters are lacking. The aim of this review was to identify the characteristics of a successful MITS and compare these for different disciplines, MI session types, task focus, age, gender and MI modification during intervention. Methods An extended systematic literature search using 24 databases was performed for five disciplines: Education, Medicine, Music, Psychology and Sports. References that described an MI intervention that focused on motor skills, performance or strength improvement were included. Information describing 17 MITS elements was extracted based on the PETTLEP (physical, environment, timing, task, learning, emotion, perspective approach. Seven elements describing the MITS temporal parameters were calculated: study duration, intervention duration, MITS duration, total MITS count, MITS per week, MI trials per MITS and total MI training time. Results Both independent reviewers found 96% congruity, which was tested on a random sample of 20% of all references. After selection, 133 studies reporting 141 MI interventions were included. The locations of the MITS and position of the participants during MI were task-specific. Participants received acoustic detailed MI instructions, which were mostly standardised and live. During MI practice, participants kept their eyes closed. MI training was performed from an internal perspective with a kinaesthetic mode. Changes in MI content, duration and dosage were reported in 31 MI interventions. Familiarisation sessions before the start of the MI intervention were mentioned in 17 reports. MI interventions focused with decreasing relevance on motor-, cognitive- and strength-focused tasks. Average study intervention lasted 34 days, with participants practicing MI on average three times per week for 17

  4. The effect of motor imagery with specific implement in expert badminton player.

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    Wang, Z; Wang, S; Shi, F-Y; Guan, Y; Wu, Y; Zhang, L-L; Shen, C; Zeng, Y-W; Wang, D-H; Zhang, J

    2014-09-01

    Motor skill can be improved with mental simulation. Implements are widely used in daily life and in various sports. However, it is unclear whether the utilization of implements enhances the effect of mental simulation. The present study was designed to investigate the different effects of motor imagery in athletes and novices when they handled a specific implement. We hypothesize that athletes have better motor imagery ability than novices when they hold a specific implement for the sport. This is manifested as higher motor cortical excitability in athletes than novices during motor imagery with the specific implement. Sixteen expert badminton players and 16 novices were compared when they held a specific implement such as a badminton racket and a non-specific implement such as a a plastic bar. Motor imagery ability was measured with a self-evaluation questionnaire. Transcranial magnetic stimulation was used to test the motor cortical excitability during motor imagery. Motor-evoked potentials (MEPs) in the first dorsal interosseous (FDI) and extensor carpi radialis muscles were recorded. Athletes reported better motor imagery than novices when they held a specific implement. Athletes exhibited more MEP facilitation than novices in the FDI muscle with the specific implement applied during motor imagery. The MEP facilitation is correlated with motor imagery ability in athletes. We conclude that the effects of motor imagery with a specific implement are enhanced in athletes compared to novices and the difference between two groups is caused by long-term physical training of athletes with the specific implement.

  5. Can motor imagery and hypnotic susceptibility explain Conversion Disorder with motor symptoms?

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    Srzich, Alexander J; Byblow, Winston D; Stinear, James W; Cirillo, John; Anson, J Greg

    2016-08-01

    Marked distortions in sense of agency can be induced by hypnosis in susceptible individuals, including alterations in subjective awareness of movement initiation and control. These distortions, with associated disability, are similar to those experienced with Conversion Disorder (CD), an observation that has led to the hypothesis that hypnosis and CD share causal mechanisms. The purpose of this review is to explore the relationships among motor imagery (MI), hypnotic susceptibility, and CD, then to propose how MI ability may contribute to hypnotic responding and CD. Studies employing subjective assessments of mental imagery have found little association between imagery abilities and hypnotic susceptibility. A positive association between imagery abilities and hypnotic susceptibility becomes apparent when objective measures of imagery ability are employed. A candidate mechanism to explain motor responses during hypnosis is kinaesthetic MI, which engages a strategy that involves proprioception or the "feel" of movement when no movement occurs. Motor suppression imagery (MSI), a strategy involving inhibition of movement, may provide an alternate objective measurable phenomenon that underlies both hypnotic susceptibility and CD. Evidence to date supports the idea that there may be a positive association between kinaesthetic MI ability and hypnotic susceptibility. Additional evidence supports a positive association between hypnotic susceptibility and CD. Disturbances in kinaesthetic MI performance in CD patients indicate that MI mechanisms may also underlie CD symptoms. Further investigation of the above relationships is warranted to explain these phenomena, and establish theoretical explanations underlying sense of agency. PMID:27346334

  6. Local Temporal Correlation Common Spatial Patterns for Single Trial EEG Classification during Motor Imagery

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    Rui Zhang

    2013-01-01

    Full Text Available Common spatial pattern (CSP is one of the most popular and effective feature extraction methods for motor imagery-based brain-computer interface (BCI, but the inherent drawback of CSP is that the estimation of the covariance matrices is sensitive to noise. In this work, local temporal correlation (LTC information was introduced to further improve the covariance matrices estimation (LTCCSP. Compared to the Euclidean distance used in a previous CSP variant named local temporal CSP (LTCSP, the correlation may be a more reasonable metric to measure the similarity of activated spatial patterns existing in motor imagery period. Numerical comparisons among CSP, LTCSP, and LTCCSP were quantitatively conducted on the simulated datasets by adding outliers to Dataset IVa of BCI Competition III and Dataset IIa of BCI Competition IV, respectively. Results showed that LTCCSP achieves the highest average classification accuracies in all the outliers occurrence frequencies. The application of the three methods to the EEG dataset recorded in our laboratory also demonstrated that LTCCSP achieves the highest average accuracy. The above results consistently indicate that LTCCSP would be a promising method for practical motor imagery BCI application.

  7. Comparison of Sensory-motor Rhythm and Movement Related Cortical Potential during Ballistic and Repetitive Motor Imagery

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    XU Ren; JIANG Ning; MRACHACZ-KERSTING Natalie; DREMSTRUP Kim; FARINA Dario

    2014-01-01

    In this study, we compared two types of EEG modalities, sensory-motor rhythms (SMR) and movement related cortical potentials (MRCP), on four healthy subjects performing ballistic or repetitive movement imagination. The EEG waveform morphology across subjects was similar for MRCPs, whereas there was not a clear pattern for SMRs. The rank-sum test showed a significant difference between the amplitude of baseline and that of the MRCP as early as 2 s prior to imagery onset, for both types of motor imageries, indicating strong discriminative power of MRCPs for predicting movement onset. For SMR, this type of discriminative power was relatively weak and highly subject-specific. On the other hand, the SMR landscape under the two movement imagery types was distinctive, holding a potential for discriminating the two movement imagery types. These preliminary results presented different characteristics of SMR and MRCP under different motor imageries, providing valuable information regarding the design and implementation of motor imagery based on BCI system.

  8. Neurofeedback using real-time near-infrared spectroscopy enhances motor imagery related cortical activation.

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    Masahito Mihara

    Full Text Available Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practices in the form of motor imagery have been implemented in rehabilitation regimes of stroke patients with favorable results. Because direct monitoring of motor imagery is difficult, feedback of cortical activities related to motor imagery (neurofeedback could help to enhance efficacy of mental practice with motor imagery. To determine the feasibility and efficacy of a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS, two separate experiments were performed. Experiment 1 was used in five subjects to evaluate whether real-time cortical oxygenated hemoglobin signal feedback during a motor execution task correlated with reference hemoglobin signals computed off-line. Results demonstrated that the NIRS-mediated neurofeedback system reliably detected oxygenated hemoglobin signal changes in real-time. In Experiment 2, 21 subjects performed motor imagery of finger movements with feedback from relevant cortical signals and irrelevant sham signals. Real neurofeedback induced significantly greater activation of the contralateral premotor cortex and greater self-assessment scores for kinesthetic motor imagery compared with sham feedback. These findings suggested the feasibility and potential effectiveness of a NIRS-mediated real-time neurofeedback system on performance of kinesthetic motor imagery. However, these results warrant further clinical trials to determine whether this system could enhance the effects of mental practice in stroke patients.

  9. Motor imagery training in hemiplegic cerebral palsy: a potentially useful therapeutic tool for rehabilitation

    NARCIS (Netherlands)

    Steenbergen, B.; Craje, Céline; Nilsen, D.M.; Gordon, A.M.

    2009-01-01

    Converging evidence indicates that motor deficits in cerebral palsy (CP) are related not only to problems with execution, but also to impaired motor planning. Current rehabilitation mainly focuses on alleviating compromised motor execution. Motor imagery is a promising method of training the more 'c

  10. Detection of motor imagery of brisk walking from electroencephalogram.

    Science.gov (United States)

    Yang, Huijuan; Guan, Cuntai; Wang, Chuan Chu; Ang, Kai Keng

    2015-04-15

    Rehabilitation of lower limbs is equally as important as that of upper limbs. This paper presented a study to detect motor imagery of walking (MI-Walking) from background idle state. Broad overlapping neuronal networks involved in reorganization following motor imagery introduce redundancy. We hypothesized that MI-Walking could be robustly detected by constraining dependency among selected features and class separations. Hence, we proposed to jointly select channels and frequency bands involved in MI-Walking by optimizing/regularizing the objective function formulated on the dependency between features and class labels, redundancy between to-be-selected with selected features, and separations between classes, namely, "regularized maximum dependency with minimum redundancy-based joint channel and frequency band selection (RMDR-JCFS)". Evaluated on electroencephalography (EEG) data of 11 healthy subjects, the results showed that the selected channels were mainly located at premotor cortex, mid-central area overlaying supplementary motor area (SMA), prefrontal cortex, foot area sensory cortex and leg and arm sensorimotor representation area. Broad frequencies of alpha, mu and beta rhythms were involved. Our proposed method yielded an averaged accuracy of 76.67%, which was 9.08%, 5.03%, 7.03%, 14.15% and 3.88% higher than that obtained by common spatial pattern (CSP), filter-bank CSP, sliding window discriminate CSP, filter-bank power and maximum dependency and minimum redundancy methods, respectively. Further, our method yielded significantly superior performance compared with other channel selection methods, and it yielded an averaged session-to-session accuracy of 70.14%. These results demonstrated the potentials of detecting MI-Walking using proposed method for stroke rehabilitation.

  11. Efficient resting-state EEG network facilitates motor imagery performance

    Science.gov (United States)

    Zhang, Rui; Yao, Dezhong; Valdés-Sosa, Pedro A.; Li, Fali; Li, Peiyang; Zhang, Tao; Ma, Teng; Li, Yongjie; Xu, Peng

    2015-12-01

    Objective. Motor imagery-based brain-computer interface (MI-BCI) systems hold promise in motor function rehabilitation and assistance for motor function impaired people. But the ability to operate an MI-BCI varies across subjects, which becomes a substantial problem for practical BCI applications beyond the laboratory. Approach. Several previous studies have demonstrated that individual MI-BCI performance is related to the resting state of brain. In this study, we further investigate offline MI-BCI performance variations through the perspective of resting-state electroencephalography (EEG) network. Main results. Spatial topologies and statistical measures of the network have close relationships with MI classification accuracy. Specifically, mean functional connectivity, node degrees, edge strengths, clustering coefficient, local efficiency and global efficiency are positively correlated with MI classification accuracy, whereas the characteristic path length is negatively correlated with MI classification accuracy. The above results indicate that an efficient background EEG network may facilitate MI-BCI performance. Finally, a multiple linear regression model was adopted to predict subjects’ MI classification accuracy based on the efficiency measures of the resting-state EEG network, resulting in a reliable prediction. Significance. This study reveals the network mechanisms of the MI-BCI and may help to find new strategies for improving MI-BCI performance.

  12. New evidence of corticospinal network modulation induced by motor imagery.

    Science.gov (United States)

    Grosprêtre, Sidney; Lebon, Florent; Papaxanthis, Charalambos; Martin, Alain

    2016-03-01

    Motor imagery (MI) is the mental simulation of movement, without the corresponding muscle contraction. Whereas the activation of cortical motor areas during MI is established, the involvement of spinal structures is still under debate. We used original and complementary techniques to probe the influence of MI on spinal structures. Amplitude of motor-evoked potentials (MEPs), cervico-medullary-evoked potentials (CMEPs), and Hoffmann (H)-reflexes of the flexor carpi radialis (FCR) muscle and of the triceps surae muscles was measured in young, healthy subjects at rest and during MI. Participants were asked to imagine maximal voluntary contraction of the wrist and ankle, while the targeted limb was fixed (static condition). We confirmed previous studies with an increase of FCR MEPs during MI compared with rest. Interestingly, CMEPs, but not H-reflexes, also increased during MI, revealing a possible activation of subcortical structures. Then, to investigate the effect of MI on the spinal network, we used two techniques: 1) passive lengthening of the targeted muscle via an isokinetic dynamometer and 2) conditioning of H-reflexes with stimulation of the antagonistic nerve. Both techniques activate spinal inhibitory presynaptic circuitry, reducing the H-reflex amplitude at rest. In contrast, no reduction of H-reflex amplitude was observed during MI. These findings suggest that MI has modulatory effects on the spinal neuronal network. Specifically, the activation of low-threshold spinal structures during specific conditions (lengthening and H-reflex conditioning) highlights the possible generation of subliminal cortical output during MI. PMID:26719089

  13. Oscillatory entrainment of the motor cortical network during motor imagery is modulated by the feedback modality.

    Science.gov (United States)

    Vukelić, Mathias; Gharabaghi, Alireza

    2015-05-01

    Neurofeedback of self-regulated brain activity in circumscribed cortical regions is used as a novel strategy to facilitate functional restoration following stroke. Basic knowledge about its impact on motor system oscillations and functional connectivity is however scarce. Specifically, a direct comparison between different feedback modalities and their neural signatures is missing. We assessed a neurofeedback training intervention of modulating β-activity in circumscribed sensorimotor regions by kinesthetic motor imagery (MI). Right-handed healthy participants received two different feedback modalities contingent to their MI-associated brain activity in a cross-over design: (I) visual feedback with a brain-computer interface (BCI) and (II) proprioceptive feedback with a brain-robot interface (BRI) orthosis attached to the right hand. High-density electroencephalography was used to examine the reactivity of the cortical motor system during the training session of each task by studying both local oscillatory power entrainment and distributed functional connectivity. Both feedback modalities activated a distributed functional connectivity network of coherent oscillations. A significantly higher skill and lower variability of self-controlled sensorimotor β-band modulation could, however, be achieved in the BRI condition. This gain in controlling regional motor oscillations was accompanied by functional coupling of remote β-band and θ-band activity in bilateral fronto-central regions and left parieto-occipital regions, respectively. The functional coupling of coherent θ-band oscillations correlated moreover with the skill of regional β-modulation thus revealing a motor learning related network. Our findings indicate that proprioceptive feedback is more suitable than visual feedback to entrain the motor network architecture during the interplay between motor imagery and feedback processing thus resulting in better volitional control of regional brain activity.

  14. Multiple roles of motor imagery during action observation

    Directory of Open Access Journals (Sweden)

    Stefan eVogt

    2013-11-01

    Full Text Available Over the last 20 years, the topics of action observation (AO and motor imagery (MI have been largely studied in isolation from each other, despite the early integrative account by Jeannerod (1994, 2001. Recent neuroimaging studies demonstrate enhanced cortical activity when AO and MI are performed concurrently ('AO+MI', compared to either AO or MI performed in isolation. These results indicate the potentially beneficial effects of AO+MI, and they also demonstrate that the underlying neurocognitive processes are partly shared. We separately review the evidence for MI and AO as forms of motor simulation, and present two quantitative literature analyses that indeed indicate rather little overlap between the two bodies of research. We then propose a spectrum of concurrent AO+MI states, from congruent AO+MI where the contents of AO and MI widely overlap, over coordinative AO+MI, where observed and imagined action are different but can be coordinated with each other, to cases of conflicting AO+MI. We believe that an integrative account of AO and MI is theoretically attractive, that it should generate novel experimental approaches, and that it can also stimulate a wide range of applications in sport, occupational therapy, and neurorehabilitation.

  15. MOTOR IMAGERY AND TENNIS SERVE PERFORMANCE: THE EXTERNAL FOCUS EFFICACY

    Directory of Open Access Journals (Sweden)

    Aymeric Guillot

    2013-06-01

    Full Text Available There is now ample evidence that motor imagery (MI contributes to enhance motor performance. Previous research also demonstrated that directing athletes' attention to the effects of their movements on the environment is more effective than focusing on the action per se. The present study aimed therefore at evaluating whether adopting an external focus during MI contributes to enhance tennis serve performance. Twelve high-level young tennis players were included in a test-retest procedure. The effects of regular training were first evaluated. Then, players were subjected to a MI intervention during which they mentally focused on ball trajectory and specifically visualized the space above the net where the serve can be successfully hit. Serve performance was evaluated during both a validated serve test and a real match. The main results showed a significant increase in accuracy and velocity during the ecological serve test after MI practice, as well as a significant improvement in successful first serves and won points during the match. Present data therefore confirmed the efficacy of MI in combination of physical practice to improve tennis serve performance, and further provided evidence that it is feasible to adopt external attentional focus during MI. Practical applications are discussed

  16. Combining motor imagery with selective sensation toward a hybrid-modality BCI.

    Science.gov (United States)

    Yao, Lin; Meng, Jianjun; Zhang, Dingguo; Sheng, Xinjun; Zhu, Xiangyang

    2014-08-01

    A hybrid modality brain-computer interface (BCI) is proposed in this paper, which combines motor imagery with selective sensation to enhance the discrimination between left and right mental tasks, e.g., the classification between left/ right stimulation sensation and right/ left motor imagery. In this paradigm, wearable vibrotactile rings are used to stimulate both the skin on both wrists. Subjects are required to perform the mental tasks according to the randomly presented cues (i.e., left hand motor imagery, right hand motor imagery, left stimulation sensation or right stimulation sensation). Two-way ANOVA statistical analysis showed a significant group effect (F (2,20) = 7.17, p = 0.0045), and the Benferroni-corrected multiple comparison test (with α = 0.05) showed that the hybrid modality group is 11.13% higher on average than the motor imagery group, and 10.45% higher than the selective sensation group. The hybrid modality experiment exhibits potentially wider spread usage within ten subjects crossed 70% accuracy, followed by four subjects in motor imagery and five subjects in selective sensation. Six subjects showed statistically significant improvement ( Benferroni-corrected) in hybrid modality in comparison with both motor imagery and selective sensation. Furthermore, among subjects having difficulties in both motor imagery and selective sensation, the hybrid modality improves their performance to 90% accuracy. The proposed hybrid modality BCI has demonstrated clear benefits for those poorly performing BCI users. Not only does the requirement of motor and sensory anticipation in this hybrid modality provide basic function of BCI for communication and control, it also has the potential for enhancing the rehabilitation during motor recovery.

  17. Assessing motor imagery using the hand rotation task: Does performance change across childhood?

    NARCIS (Netherlands)

    Butson, M.L.; Hyde, C.; Steenbergen, B.; Williams, J.

    2014-01-01

    This study examined at what age children can engage in the hand rotation task (as a measure of motor imagery); whether engagement changes across development and; the influence of age and motor skill on performance. Children were aged 5-12 years (N = 101; 52 girls), with no IQ or motor skill impairme

  18. Using motor imagery to study the neural substrates of dynamic balance

    OpenAIRE

    Murielle Ursulla Ferraye; Bettina Debû; Lieke Heil; Mark Carpenter; Bastiaan Roelof Bloem; Ivan Toni

    2014-01-01

    This study examines the cerebral structures involved in dynamic balance using a motor imagery (MI) protocol. We recorded cerebral activity with functional magnetic resonance imaging while subjects imagined swaying on a balance board along the sagittal plane to point a laser at target pairs of different sizes (small, large). We used a matched visual imagery (VI) control task and recorded imagery durations during scanning. MI and VI durations were differentially influenced by the sway accuracy ...

  19. Context-aware adaptive spelling in motor imagery BCI

    Science.gov (United States)

    Perdikis, S.; Leeb, R.; Millán, J. d. R.

    2016-06-01

    Objective. This work presents a first motor imagery-based, adaptive brain-computer interface (BCI) speller, which is able to exploit application-derived context for improved, simultaneous classifier adaptation and spelling. Online spelling experiments with ten able-bodied users evaluate the ability of our scheme, first, to alleviate non-stationarity of brain signals for restoring the subject’s performances, second, to guide naive users into BCI control avoiding initial offline BCI calibration and, third, to outperform regular unsupervised adaptation. Approach. Our co-adaptive framework combines the BrainTree speller with smooth-batch linear discriminant analysis adaptation. The latter enjoys contextual assistance through BrainTree’s language model to improve online expectation-maximization maximum-likelihood estimation. Main results. Our results verify the possibility to restore single-sample classification and BCI command accuracy, as well as spelling speed for expert users. Most importantly, context-aware adaptation performs significantly better than its unsupervised equivalent and similar to the supervised one. Although no significant differences are found with respect to the state-of-the-art PMean approach, the proposed algorithm is shown to be advantageous for 30% of the users. Significance. We demonstrate the possibility to circumvent supervised BCI recalibration, saving time without compromising the adaptation quality. On the other hand, we show that this type of classifier adaptation is not as efficient for BCI training purposes.

  20. Electroencephalographic Motor Imagery Brain Connectivity Analysis for BCI: A Review.

    Science.gov (United States)

    Hamedi, Mahyar; Salleh, Sh-Hussain; Noor, Alias Mohd

    2016-06-01

    Recent research has reached a consensus on the feasibility of motor imagery brain-computer interface (MI-BCI) for different applications, especially in stroke rehabilitation. Most MI-BCI systems rely on temporal, spectral, and spatial features of single channels to distinguish different MI patterns. However, no successful communication has been established for a completely locked-in subject. To provide more useful and informative features, it has been recommended to take into account the relationships among electroencephalographic (EEG) sensor/source signals in the form of brain connectivity as an efficient tool of neuroscience. In this review, we briefly report the challenges and limitations of conventional MI-BCIs. Brain connectivity analysis, particularly functional and effective, has been described as one of the most promising approaches for improving MI-BCI performance. An extensive literature on EEG-based MI brain connectivity analysis of healthy subjects is reviewed. We subsequently discuss the brain connectomes during left and right hand, feet, and tongue MI movements. Moreover, key components involved in brain connectivity analysis that considerably affect the results are explained. Finally, possible technical shortcomings that may have influenced the results in previous research are addressed and suggestions are provided. PMID:27137671

  1. Context-aware adaptive spelling in motor imagery BCI

    Science.gov (United States)

    Perdikis, S.; Leeb, R.; Millán, J. d. R.

    2016-06-01

    Objective. This work presents a first motor imagery-based, adaptive brain–computer interface (BCI) speller, which is able to exploit application-derived context for improved, simultaneous classifier adaptation and spelling. Online spelling experiments with ten able-bodied users evaluate the ability of our scheme, first, to alleviate non-stationarity of brain signals for restoring the subject’s performances, second, to guide naive users into BCI control avoiding initial offline BCI calibration and, third, to outperform regular unsupervised adaptation. Approach. Our co-adaptive framework combines the BrainTree speller with smooth-batch linear discriminant analysis adaptation. The latter enjoys contextual assistance through BrainTree’s language model to improve online expectation-maximization maximum-likelihood estimation. Main results. Our results verify the possibility to restore single-sample classification and BCI command accuracy, as well as spelling speed for expert users. Most importantly, context-aware adaptation performs significantly better than its unsupervised equivalent and similar to the supervised one. Although no significant differences are found with respect to the state-of-the-art PMean approach, the proposed algorithm is shown to be advantageous for 30% of the users. Significance. We demonstrate the possibility to circumvent supervised BCI recalibration, saving time without compromising the adaptation quality. On the other hand, we show that this type of classifier adaptation is not as efficient for BCI training purposes.

  2. Patients' Views on a Combined Action Observation and Motor Imagery Intervention for Parkinson's Disease

    Science.gov (United States)

    Webb, Jordan; Gowen, Emma; Vogt, Stefan; Crawford, Trevor J.; Sullivan, Matthew S.; Poliakoff, Ellen

    2016-01-01

    Background. Action observation and motor imagery activate neural structures involved in action execution, thereby facilitating movement and learning. Although some benefits of action observation and motor imagery have been reported in Parkinson's disease (PD), methods have been based on stroke rehabilitation and may be less suitable for PD. Moreover, previous studies have focused on either observation or imagery, yet combining these enhances effects in healthy participants. The present study explores the feasibility of a PD-specific home-based intervention combining observation, imagery, and imitation of meaningful everyday actions. Methods. A focus group was conducted with six people with mild to moderate PD and two companions, exploring topics relating to the utility and feasibility of a home-based observation and imagery intervention. Results. Five themes were identified. Participants reported their experiences of exercise and use of action observation and motor imagery in everyday activities, and the need for strategies to improve movement was expressed. Motivational factors including feedback, challenge, and social support were identified as key issues. The importance of offering a broad range of actions and flexible training was also highlighted. Conclusions. A home-based intervention utilising action observation and motor imagery would be useful and feasible in mild to moderate PD. PMID:27777809

  3. Patients’ Views on a Combined Action Observation and Motor Imagery Intervention for Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Judith Bek

    2016-01-01

    Full Text Available Background. Action observation and motor imagery activate neural structures involved in action execution, thereby facilitating movement and learning. Although some benefits of action observation and motor imagery have been reported in Parkinson’s disease (PD, methods have been based on stroke rehabilitation and may be less suitable for PD. Moreover, previous studies have focused on either observation or imagery, yet combining these enhances effects in healthy participants. The present study explores the feasibility of a PD-specific home-based intervention combining observation, imagery, and imitation of meaningful everyday actions. Methods. A focus group was conducted with six people with mild to moderate PD and two companions, exploring topics relating to the utility and feasibility of a home-based observation and imagery intervention. Results. Five themes were identified. Participants reported their experiences of exercise and use of action observation and motor imagery in everyday activities, and the need for strategies to improve movement was expressed. Motivational factors including feedback, challenge, and social support were identified as key issues. The importance of offering a broad range of actions and flexible training was also highlighted. Conclusions. A home-based intervention utilising action observation and motor imagery would be useful and feasible in mild to moderate PD.

  4. Improvement in precision grip force control with self-modulation of primary motor cortex during motor imagery

    Directory of Open Access Journals (Sweden)

    Maria Laura eBlefari

    2015-02-01

    Full Text Available Motor imagery (MI has shown effectiveness in enhancing motor performance. This may be due to the common neural mechanisms underlying MI and motor execution (ME. The main region of the ME network, the primary motor cortex (M1, has been consistently linked to motor performance. However, the activation of M1 during motor imagery is controversial, which may account for inconsistent rehabilitation therapy outcomes using MI. Here, we examined the relationship between contralateral M1 (cM1 activation during MI and changes in sensorimotor performance. To aid cM1 activity modulation during MI, we used real-time fMRI neurofeedback-guided MI based on cM1 hand area blood oxygen level dependent (BOLD signal in healthy subjects, performing kinesthetic MI of pinching. We used multiple regression analysis to examine the correlation between cM1 BOLD signal and changes in motor performance during an isometric pinching task of those subjects who were able to activate cM1 during motor imagery. Activities in premotor and parietal regions were used as covariates. We found that cM1 activity was positively correlated to improvements in accuracy as well as overall performance improvements, whereas other regions in the sensorimotor network were not. The association between cM1 activation during MI with performance changes indicates that subjects with stronger cM1 activation during MI may benefit more from MI training, with implications towards targeted neurotherapy.

  5. Stimulation through Simulation? Motor Imagery and Functional Reorganization in Hemiplegic Stroke Patients

    Science.gov (United States)

    Johnson-Frey, Scott H.

    2004-01-01

    A key factor influencing reorganization of function in damaged neural networks of the adult brain is stimulation. How to stimulate motor areas of patients with paralyses is a formidable challenge. One possibility is to use internal movement simulations, or motor imagery, as an alternative to conventional therapeutic interventions that require…

  6. Short time sports exercise boosts motor imagery patterns: Implications of mental practice in rehabilitation programs

    Directory of Open Access Journals (Sweden)

    Selina Christin Wriessnegger

    2014-06-01

    Full Text Available Motor imagery (MI is a commonly used paradigm for the study of motor learning or cognitive aspects of action control. The rationale for using MI training to promote the relearning of motor function arises from research on the functional correlates that MI shares with the execution of physical movements. While most of the previous studies investigating MI were based on simple movements in the present study a more attractive mental practice was used to investigate cortical activation during MI. We measured cerebral responses with functional magnetic resonance imaging (fMRI in twenty three healthy volunteers as they imagined playing soccer or tennis before and after a short physical sports exercise. Our results demonstrated that only 10 minutes of training are enough to boost motor imagery patterns in motor related brain regions including premotor cortex and supplementary motor area (SMA but also fronto-parietal and subcortical structures. This supports previous findings that motor imagery has beneficial effects especially in combination with motor execution when used in motor rehabilitation or motor learning processes. We conclude that sports MI combined with an interactive game environment could be a promising additional tool in future rehabilitation programs aiming to improve upper or lower limb functions or support neuroplasticity.

  7. Effect of biased feedback on motor imagery learning in BCI-teleoperation system

    Directory of Open Access Journals (Sweden)

    Maryam eAlimardani

    2014-04-01

    Full Text Available Feedback design is an important issue in motor imagery BCI systems. Regardless, to date it has not been reported how feedback presentation can optimize co-adaptation between a human brain and such systems. This paper assesses the effect of realistic visual feedback on users’ BC performance and motor imagery skills. We previously developed a tele-operation system for a pair of humanlike robotic hands and showed that BCI control of such hands along with first-person perspective visual feedback of movements can arouse a sense of embodiment in the operators. In the first stage of this study, we found that the intensity of this ownership illusion was associated with feedback presentation and subjects’ performance during BCI motion control. In the second stage, we probed the effect of positive and negative feedback bias on subjects’ BCI performance and motor imagery skills. Although the subject specific classifier, which was set up at the beginning of experiment, detected no significant change in the subjects’ online performance, evaluation of brain activity patterns revealed that subjects’ self-regulation of motor imagery features improved due to a positive bias of feedback and a possible occurrence of ownership illusion. Our findings suggest that in general training protocols for BCIs, manipulation of feedback can play an important role in the optimization of subjects’ motor imagery skills.

  8. Neural evidence for compromised motor imagery in right hemiparetic cerebral palsy

    Directory of Open Access Journals (Sweden)

    Michiel Van Elk

    2010-11-01

    Full Text Available In the present EEG study we investigated the neural and temporal dynamics of motor imagery in participants with right-sided HCP (n = 10 and in left-handed control participants (n = 10. A mental rotation task was used in which participants were required to judge the laterality of hand pictures. At a behavioral level participants with HCP were slower in making hand laterality judgments compared to control subjects, especially when presented with pictures representing the affected hand. At a neural level, individuals with HCP were characterized by a reduced rotation-related negativity (RRN over parietal areas, that was delayed in onset with respect to control participants. Interestingly, participants that were relatively mildly impaired showed a stronger RRN for the rotation of right hand stimuli than participants that were more strongly impaired in their motor function, suggesting a direct relation between the motor imagery process and the biomechanical constraints of the participant. Together, the results provide new insights in the relation between motor imagery and motor capabilities and indicate that participants with HCP may be characterized by a compromised ability to use motor imagery.

  9. Spectral entropy analysis of different alpha band rhythms in relation to hand motor imagery

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The event-related desynchronization/synchronization(ERD/ERS) time courses of lower and upper alpha band rhythms during hand motor imagery are investigated respectively by Fourier Sectral Entropy (FSE) in this paper. By analyzing one group of BCI competition data, it was found that FSE within upper alpha band displays a pronounced increase and decrease over contralateral and ipsilaterai brain areas respectively at the onset of hand motor imagery, which is corresponding to the antagonistic ERD/ERS patterns in previous studies. Different from the upper alpha activity pattern, FSE within lower alpha band displays a consistent increase over both two hemispheres hand representative areas. The preliminary results show that FSE could disclose the different behaviors of the upper and lower alpha band rhythms so that a new idea with the complexity measure is provided to characterize functional dissociation of lower and upper frequency alpha rhythms in relation to hand motor imagery.

  10. The Importance of Visual Feedback Design in BCIs; from Embodiment to Motor Imagery Learning

    Science.gov (United States)

    Alimardani, Maryam; Nishio, Shuichi; Ishiguro, Hiroshi

    2016-01-01

    Brain computer interfaces (BCIs) have been developed and implemented in many areas as a new communication channel between the human brain and external devices. Despite their rapid growth and broad popularity, the inaccurate performance and cost of user-training are yet the main issues that prevent their application out of the research and clinical environment. We previously introduced a BCI system for the control of a very humanlike android that could raise a sense of embodiment and agency in the operators only by imagining a movement (motor imagery) and watching the robot perform it. Also using the same setup, we further discovered that the positive bias of subjects’ performance both increased their sensation of embodiment and improved their motor imagery skills in a short period. In this work, we studied the shared mechanism between the experience of embodiment and motor imagery. We compared the trend of motor imagery learning when two groups of subjects BCI-operated different looking robots, a very humanlike android’s hands and a pair of metallic gripper. Although our experiments did not show a significant change of learning between the two groups immediately during one session, the android group revealed better motor imagery skills in the follow up session when both groups repeated the task using the non-humanlike gripper. This result shows that motor imagery skills learnt during the BCI-operation of humanlike hands are more robust to time and visual feedback changes. We discuss the role of embodiment and mirror neuron system in such outcome and propose the application of androids for efficient BCI training. PMID:27598310

  11. Efficacy of motor imagery in post-stroke rehabilitation: a systematic review

    Directory of Open Access Journals (Sweden)

    Puhan Milo A

    2008-03-01

    Full Text Available Abstract Background Evaluation of how Motor Imagery and conventional therapy (physiotherapy or occupational therapy compare to conventional therapy only in their effects on clinically relevant outcomes during rehabilitation of persons with stroke. Design Systematic review of the literature Methods We conducted an electronic database search in seven databases in August 2005 and also hand-searched the bibliographies of studies that we selected for the review. Two reviewers independently screened and selected all randomized controlled trials that compare the effects of conventional therapy plus Motor Imagery to those of only conventional therapy on stroke patients. The outcome measurements were: Fugl-Meyer Stroke Assessment upper extremity score (66 points and Action Research Arm Test upper extremity score (57 points. Due to the high variability in the outcomes, we could not pool the data statistically. Results We identified four randomized controlled trials from Asia and North America. The quality of the included studies was poor to moderate. Two different Motor imagery techniques were used (three studies used audiotapes and one study had occupational therapists apply the intervention. Two studies found significant effects of Motor Imagery in the Fugl-Meyer Stroke Assessment: Differences between groups amounted to 11.0 (1.0 to 21.0 and 3.2 (-4 to 10.3 respectively and in the Action Research Arm Test 6.1 (-6.2 to 18.4 and 15.8 (0.5 to 31.0 respectively. One study did not find a significant effect in the Fugl-Meyer Stroke Assessment and Color trail Test (p = 0.28 but in the task-related outcomes (p > 0.001. Conclusion Current evidence suggests that Motor imagery provides additional benefits to conventional physiotherapy or occupational therapy. However, larger and methodologically sounder studies should be conducted to assess the benefits of Motor imagery.

  12. The Importance of Visual Feedback Design in BCIs; from Embodiment to Motor Imagery Learning.

    Science.gov (United States)

    Alimardani, Maryam; Nishio, Shuichi; Ishiguro, Hiroshi

    2016-01-01

    Brain computer interfaces (BCIs) have been developed and implemented in many areas as a new communication channel between the human brain and external devices. Despite their rapid growth and broad popularity, the inaccurate performance and cost of user-training are yet the main issues that prevent their application out of the research and clinical environment. We previously introduced a BCI system for the control of a very humanlike android that could raise a sense of embodiment and agency in the operators only by imagining a movement (motor imagery) and watching the robot perform it. Also using the same setup, we further discovered that the positive bias of subjects' performance both increased their sensation of embodiment and improved their motor imagery skills in a short period. In this work, we studied the shared mechanism between the experience of embodiment and motor imagery. We compared the trend of motor imagery learning when two groups of subjects BCI-operated different looking robots, a very humanlike android's hands and a pair of metallic gripper. Although our experiments did not show a significant change of learning between the two groups immediately during one session, the android group revealed better motor imagery skills in the follow up session when both groups repeated the task using the non-humanlike gripper. This result shows that motor imagery skills learnt during the BCI-operation of humanlike hands are more robust to time and visual feedback changes. We discuss the role of embodiment and mirror neuron system in such outcome and propose the application of androids for efficient BCI training.

  13. The Importance of Visual Feedback Design in BCIs; from Embodiment to Motor Imagery Learning.

    Science.gov (United States)

    Alimardani, Maryam; Nishio, Shuichi; Ishiguro, Hiroshi

    2016-01-01

    Brain computer interfaces (BCIs) have been developed and implemented in many areas as a new communication channel between the human brain and external devices. Despite their rapid growth and broad popularity, the inaccurate performance and cost of user-training are yet the main issues that prevent their application out of the research and clinical environment. We previously introduced a BCI system for the control of a very humanlike android that could raise a sense of embodiment and agency in the operators only by imagining a movement (motor imagery) and watching the robot perform it. Also using the same setup, we further discovered that the positive bias of subjects' performance both increased their sensation of embodiment and improved their motor imagery skills in a short period. In this work, we studied the shared mechanism between the experience of embodiment and motor imagery. We compared the trend of motor imagery learning when two groups of subjects BCI-operated different looking robots, a very humanlike android's hands and a pair of metallic gripper. Although our experiments did not show a significant change of learning between the two groups immediately during one session, the android group revealed better motor imagery skills in the follow up session when both groups repeated the task using the non-humanlike gripper. This result shows that motor imagery skills learnt during the BCI-operation of humanlike hands are more robust to time and visual feedback changes. We discuss the role of embodiment and mirror neuron system in such outcome and propose the application of androids for efficient BCI training. PMID:27598310

  14. Classification of Motor Imagery EEG Signals with Support Vector Machines and Particle Swarm Optimization

    Science.gov (United States)

    Ma, Yuliang; Ding, Xiaohui; She, Qingshan; Luo, Zhizeng; Potter, Thomas; Zhang, Yingchun

    2016-01-01

    Support vector machines are powerful tools used to solve the small sample and nonlinear classification problems, but their ultimate classification performance depends heavily upon the selection of appropriate kernel and penalty parameters. In this study, we propose using a particle swarm optimization algorithm to optimize the selection of both the kernel and penalty parameters in order to improve the classification performance of support vector machines. The performance of the optimized classifier was evaluated with motor imagery EEG signals in terms of both classification and prediction. Results show that the optimized classifier can significantly improve the classification accuracy of motor imagery EEG signals. PMID:27313656

  15. Classification of Motor Imagery EEG Signals with Support Vector Machines and Particle Swarm Optimization.

    Science.gov (United States)

    Ma, Yuliang; Ding, Xiaohui; She, Qingshan; Luo, Zhizeng; Potter, Thomas; Zhang, Yingchun

    2016-01-01

    Support vector machines are powerful tools used to solve the small sample and nonlinear classification problems, but their ultimate classification performance depends heavily upon the selection of appropriate kernel and penalty parameters. In this study, we propose using a particle swarm optimization algorithm to optimize the selection of both the kernel and penalty parameters in order to improve the classification performance of support vector machines. The performance of the optimized classifier was evaluated with motor imagery EEG signals in terms of both classification and prediction. Results show that the optimized classifier can significantly improve the classification accuracy of motor imagery EEG signals. PMID:27313656

  16. An adaptive filter bank for motor imagery based Brain Computer Interface.

    Science.gov (United States)

    Thomas, Kavitha P; Guan, Cuntai; Tong, Lau Chiew; Prasad, Vinod A

    2008-01-01

    Brain Computer Interface (BCI) provides an alternative communication and control method for people with severe motor disabilities. Motor imagery patterns are widely used in Electroencephalogram (EEG) based BCIs. These motor imagery activities are associated with variation in alpha and beta band power of EEG signals called Event Related Desynchronization/synchronization (ERD/ERS). The dominant frequency bands are subject-specific and therefore performance of motor imagery based BCIs are sensitive to both temporal filtering and spatial filtering. As the optimum filter is strongly subject-dependent, we propose a method that selects the subject-specific discriminative frequency components using time-frequency plots of Fisher ratio of two-class motor imagery patterns. We also propose a low complexity adaptive Finite Impulse Response (FIR) filter bank system based on coefficient decimation technique which can realize the subject-specific bandpass filters adaptively depending on the information of Fisher ratio map. Features are extracted only from the selected frequency components. The proposed adaptive filter bank based system offers average classification accuracy of about 90%, which is slightly better than the existing fixed filter bank system. PMID:19162856

  17. Effects of motor imagery combined with functional electrical stimulation on upper limb motor function of patients with acute ischemic stroke

    Directory of Open Access Journals (Sweden)

    Shou-feng LIU

    2015-03-01

    Full Text Available Objective To explore the effects of motor imagery (MI combined with the third generation functional electrical stimulation (FES on upper limb motor function in acute ischemic stroke patients with hemiplegia.  Methods Forty acute ischemic stroke patients, within 48 h of onset, were randomly divided into FES group (N = 20 and combination group (FES combined with motor imagery, N = 20. All patients received basic routine rehabilitation training, for example, good limb positioning, accepting braces, balance training and training in the activities of daily living (ADL. FES group received the third generation FES therapy and the combination group also received motor imagery for 2 weeks. All of the patients were assessed with Fugl-Meyer Assessment (FMA, Action Research Arm Test (ARAT and active range of motion (AROM of wrist dorsiflexion before and after 2 weeks of treatment.  Results After 2 weeks of treatment, the 2 groups had significantly higher FMA score, ARAT score and AROM of wrist dorsiflexion than that in pre-treatment (P = 0.000, for all. Besides, the FMA score (t = - 2.528, P = 0.016, ARAT score (t = - 2.562, P = 0.014 and AROM of wrist dorsiflexion (t = - 2.469, P = 0.018 in the combination group were significantly higher than that in the FES group. There were interactions of treatment methods with observation time points (P < 0.05, for all.  Conclusions Motor imagery combined with the third generation FES can effectively promote the recovery of upper limb motor function and motion range of wrist dorsiflexion in patients with acute ischemic stroke. DOI: 10.3969/j.issn.1672-6731.2015.03.008

  18. Passive reading and motor imagery about hand actions and tool-use actions: an fMRI study.

    Science.gov (United States)

    Yang, Jie; Shu, Hua

    2014-02-01

    Recent studies have shown that motor activations in action verb comprehension can be modulated by task demands (e.g., motor imagery vs. passive reading) and the specificity of action verb meaning. However, how the two factors work together to influence the involvement of the motor system during action verb comprehension is still unclear. To address the issue, the current study investigated the brain activations in motor imagery and passive reading of verbs about hand actions and tool-use actions. Three types of Chinese verbs were used, including hand-action verbs and two types of tool-use verbs emphasizing either the hand or tools information. Results indicated that all three types of verbs elicited common activations in hand motor areas during passive reading and motor imagery. Contrast analyses showed that in the hand verbs and the tool verbs where the hand information was emphasized, motor imagery elicited stronger effects than passive reading in the superior frontal gyrus, supplemental motor area and cingulate cortex that are related to motor control and regulation. For tool-use verbs emphasizing tools information, the motor imagery task elicited stronger activity than passive reading in occipital regions related to visual imagery. These results suggest that motor activations during action verb comprehension can be modulated by task demands and semantic features of action verbs. The sensorimotor simulation during language comprehension is flexible and determined by the interactions between linguistic and extralinguistic contexts.

  19. Motor imagery and EEG-based control of spelling devices and neuroprostheses.

    Science.gov (United States)

    Neuper, Christa; Müller-Putz, Gernot R; Scherer, Reinhold; Pfurtscheller, Gert

    2006-01-01

    A brain-computer interface (BCI) transforms signals originating from the human brain into commands that can control devices or applications. With this, a BCI provides a new non-muscular communication channel, which can be used to assist patients who have highly compromised motor functions. The Graz-BCI uses motor imagery and associated oscillatory EEG signals from the sensorimotor cortex for device control. As a result of research in the past 15 years, the classification of ERD/ERS patterns in single EEG trials during motor execution and motor imagery forms the basis of this sensorimotor-rhythm controlled BCI. The major frequency bands of cortical oscillations considered here are the 8-13 and 15-30 Hz bands. This chapter describes the basic methods used in Graz-BCI research and outlines possible clinical applications. PMID:17071244

  20. Motor imagery and stroke rehabilitation : A critical discussion

    NARCIS (Netherlands)

    de Vries, Sjoerd; Mulder, Theo

    2007-01-01

    Motor disorders are a frequent consequence of stroke and much effort is invested in the re-acquisition of motor control. Although patients often regain some of their lost function after therapy, most remain chronically disabled. Functional recovery is achieved largely through reorganization processe

  1. Mild impairments of motor imagery skills in children with DCD

    NARCIS (Netherlands)

    Noten, M.M.P.G.; Wilson, P.; Ruddock, S.; Steenbergen, B.

    2014-01-01

    It has been hypothesized that the underlying mechanism of clumsy motor behaviour in children with Developmental Coordination Disorder (DCD) is caused by a deficit in the internal modelling for motor control. An internal modelling deficit can be shown on a behavioural level by a task that requires mo

  2. Using motor imagery to study the neural substrates of dynamic balance

    NARCIS (Netherlands)

    Ferraye, M.U.; Debû, B.H.G.; Heil, L.; Carpenter, M.; Bloem, B.R.; Toni, I.

    2014-01-01

    This study examines the cerebral structures involved in dynamic balance using a motor imagery (MI) protocol. We recorded cerebral activity with functional magnetic resonance imaging while subjects imagined swaying on a balance board along the sagittal plane to point a laser at target pairs of differ

  3. Phantom limb perception interferes with motor imagery after unilateral upper-limb amputation.

    Science.gov (United States)

    Lyu, Yuanyuan; Guo, Xiaoli; Bekrater-Bodmann, Robin; Flor, Herta; Tong, Shanbao

    2016-01-01

    A potential contributor to impaired motor imagery in amputees is an alteration of the body schema as a result of the presence of a phantom limb. However, the nature of the relationship between motor imagery and phantom experiences remains unknown. In this study, the influence of phantom limb perception on motor imagery was investigated using a hand mental rotation task by means of behavioral and electrophysiological measures. Compared with healthy controls, significantly prolonged response time for both the intact and missing hand were observed specifically in amputees who perceived a phantom limb during the task but not in amputees without phantom limb perception. Event-related desynchronization of EEG in the beta band (beta-ERD) in central and parietal areas showed an angular disparity specifically in amputees with phantom limb perception, with its source localized in the right inferior parietal lobule. The response time as well as the beta-ERD values were significantly positively correlated with phantom vividness. Our results suggest that phantom limb perception during the task is an important interferential factor for motor imagery after amputation and the interference might be related to a change of the body representation resulting from an unnatural posture of the phantom limb. PMID:26879749

  4. Translation of EEG spatial filters from resting to motor imagery using independent component analysis.

    Directory of Open Access Journals (Sweden)

    Yijun Wang

    Full Text Available Electroencephalogram (EEG-based brain-computer interfaces (BCIs often use spatial filters to improve signal-to-noise ratio of task-related EEG activities. To obtain robust spatial filters, large amounts of labeled data, which are often expensive and labor-intensive to obtain, need to be collected in a training procedure before online BCI control. Several studies have recently developed zero-training methods using a session-to-session scenario in order to alleviate this problem. To our knowledge, a state-to-state translation, which applies spatial filters derived from one state to another, has never been reported. This study proposes a state-to-state, zero-training method to construct spatial filters for extracting EEG changes induced by motor imagery. Independent component analysis (ICA was separately applied to the multi-channel EEG in the resting and the motor imagery states to obtain motor-related spatial filters. The resultant spatial filters were then applied to single-trial EEG to differentiate left- and right-hand imagery movements. On a motor imagery dataset collected from nine subjects, comparable classification accuracies were obtained by using ICA-based spatial filters derived from the two states (motor imagery: 87.0%, resting: 85.9%, which were both significantly higher than the accuracy achieved by using monopolar scalp EEG data (80.4%. The proposed method considerably increases the practicality of BCI systems in real-world environments because it is less sensitive to electrode misalignment across different sessions or days and does not require annotated pilot data to derive spatial filters.

  5. Increased muscle activation following motor imagery during the rehabilitation of the anterior cruciate ligament.

    Science.gov (United States)

    Lebon, Florent; Guillot, Aymeric; Collet, Christian

    2012-03-01

    Motor imagery (MI) is the mental representation of an action without any concomitant movement. MI has been used frequently after peripheral injuries to decrease pain and facilitate rehabilitation. However, little is known about the effects of MI on muscle activation underlying the motor recovery. This study aimed to assess the therapeutic effects of MI on the activation of lower limb muscles, as well as on the time course of functional recovery and pain after surgery of the anterior cruciate ligament (ACL). Twelve patients with a torn ACL were randomly assigned to a MI or control group, who both received a series of physiotherapy. Electromyographic activity of the quadriceps, pain, anthropometrical data, and lower limb motor ability were measured throughout a 12-session therapy. The data provided evidence that MI elicited greater muscle activation, even though imagery practice did not result in pain decrease. Muscle activation increase might originate from a redistribution of the central neuronal activity, as there was no anthropometric change in lower limb muscles after imagery practice. This study confirmed the effectiveness of integrating MI in a rehabilitation process by facilitating muscular properties recovery following motor impairment. MI may thus be considered a reliable adjunct therapy to help injured patients to recover motor functions after reconstructive surgery of ACL.

  6. Discrimination of EEG-Based Motor Imagery Tasks by Means of a Simple Phase Information Method

    Directory of Open Access Journals (Sweden)

    Ana Loboda

    2014-10-01

    Full Text Available We propose an off-line analysis method in order to discriminate between motor imagery tasks manipulated in a brain computer interface system. A measure of large-scale synchronization based on phase locking value is established. The results indicate that it can take advantage of the phase synchrony between scalp-recorded EEG activity in the supplementary motor area and in sezorimotor area, computing the differences between the active and the relaxation states. Phase locking value features are more discriminative in ß rhythm than in µ rhythm. The proposed method is simple, computationally efficient and proves good results on EEG Motor Movement/Imagery Dataset available from PhysioNet research resource for physiologic signals.

  7. Motor timing deficits in sequential movements in Parkinson disease are related to action planning: a motor imagery study.

    Directory of Open Access Journals (Sweden)

    Laura Avanzino

    Full Text Available Timing of sequential movements is altered in Parkinson disease (PD. Whether timing deficits in internally generated sequential movements in PD depends also on difficulties in motor planning, rather than merely on a defective ability to materially perform the planned movement is still undefined. To unveil this issue, we adopted a modified version of an established test for motor timing, i.e. the synchronization-continuation paradigm, by introducing a motor imagery task. Motor imagery is thought to involve mainly processes of movement preparation, with reduced involvement of end-stage movement execution-related processes. Fourteen patients with PD and twelve matched healthy volunteers were asked to tap in synchrony with a metronome cue (SYNC and then, when the tone stopped, to keep tapping, trying to maintain the same rhythm (CONT-EXE or to imagine tapping at the same rhythm, rather than actually performing it (CONT-MI. We tested both a sub-second and a supra-second inter-stimulus interval between the cues. Performance was recorded using a sensor-engineered glove and analyzed measuring the temporal error and the interval reproduction accuracy index. PD patients were less accurate than healthy subjects in the supra-second time reproduction task when performing both continuation tasks (CONT-MI and CONT-EXE, whereas no difference was detected in the synchronization task and on all tasks involving a sub-second interval. Our findings suggest that PD patients exhibit a selective deficit in motor timing for sequential movements that are separated by a supra-second interval and that this deficit may be explained by a defect of motor planning. Further, we propose that difficulties in motor planning are of a sufficient degree of severity in PD to affect also the motor performance in the supra-second time reproduction task.

  8. Action verbs and the primary motor cortex: a comparative TMS study of silent reading, frequency judgments, and motor imagery.

    Science.gov (United States)

    Tomasino, Barbara; Fink, Gereon R; Sparing, Roland; Dafotakis, Manuel; Weiss, Peter H

    2008-01-01

    Single pulse transcranial magnetic stimulation (TMS) was applied to the hand area of the left primary motor cortex or, as a control, to the vertex (STIMULATION: TMS(M1) vs. TMS(vertex)) while right-handed volunteers silently read verbs related to hand actions. We examined three different tasks and time points for stimulation within the same experiment: subjects indicated with their left foot when they (i) had finished reading, (ii) had judged whether the corresponding movement involved a hand rotation after simulating the hand movement, and (iii) had judged whether they would frequently encounter the action verb in a newspaper (TASK: silent reading, motor imagery, and frequency judgment). Response times were compared between TMS(M1) and TMS(vertex), both applied at different time points after stimulus onset (DELAY: 150, 300, 450, 600, and 750 ms). TMS(M1) differentially modulated task performance: there was a significant facilitatory effect of TMS(M1) for the imagery task only (about 88 ms), with subjects responding about 10% faster (compared to TMS(vertex)). In contrast, response times for silent reading and frequency judgments were unaffected by TMS(M1). No differential effect of the time point of TMS(M1) was observed. The differential effect of TMS(M1) when subjects performed a motor imagery task (relative to performing silent reading or frequency judgments with the same set of verbs) suggests that the primary motor cortex is critically involved in processing action verbs only when subjects are simulating the corresponding movement. This task-dependent effect of hand motor cortex TMS on the processing of hand-related action verbs is discussed with respect to the notion of embodied cognition and the associationist theory. PMID:18328510

  9. The Movement Imagery Questionnaire-Revised, Second Edition (MIQ-RS Is a Reliable and Valid Tool for Evaluating Motor Imagery in Stroke Populations

    Directory of Open Access Journals (Sweden)

    Andrew J. Butler

    2012-01-01

    Full Text Available Mental imagery can improve motor performance in stroke populations when combined with physical therapy. Valid and reliable instruments to evaluate the imagery ability of stroke survivors are needed to maximize the benefits of mental imagery therapy. The purposes of this study were to: examine and compare the test-retest intra-rate reliability of the Movement Imagery Questionnaire-Revised, Second Edition (MIQ-RS in stroke survivors and able-bodied controls, examine internal consistency of the visual and kinesthetic items of the MIQ-RS, determine if the MIQ-RS includes both the visual and kinesthetic dimensions of mental imagery, correlate impairment and motor imagery scores, and investigate the criterion validity of the MIQ-RS in stroke survivors by comparing the results to the KVIQ-10. Test-retest analysis indicated good levels of reliability (ICC range: .83–.99 and internal consistency (Cronbach α: .95–.98 of the visual and kinesthetic subscales in both groups. The two-factor structure of the MIQ-RS was supported by factor analysis, with the visual and kinesthetic components accounting for 88.6% and 83.4% of the total variance in the able-bodied and stroke groups, respectively. The MIQ-RS is a valid and reliable instrument in the stroke population examined and able-bodied populations and therefore useful as an outcome measure for motor imagery ability.

  10. Prediction of motor imagery based brain computer interface performance using a reaction time test.

    Science.gov (United States)

    Darvishi, Sam; Abbott, Derek; Baumert, Mathias

    2015-08-01

    Brain computer interfaces (BCIs) enable human brains to interact directly with machines. Motor imagery based BCI (MI-BCI) encodes the motor intentions of human agents and provides feedback accordingly. However, 15-30% of people are not able to perform vivid motor imagery. To save time and monetary resources, a number of predictors have been proposed to screen for users with low BCI aptitude. While the proposed predictors provide some level of correlation with MI-BCI performance, simple, objective and accurate predictors are currently not available. Thus, in this study we have examined the utility of a simple reaction time (SRT) test for predicting MI-BCI performance. We enrolled 10 subjects and measured their motor imagery performance with either visual or proprioceptive feedback. Their reaction time was also measured using a SRT test. The results show a significant negative correlation (r ≈ -0.67) between SRT and MI-BCI performance. Therefore SRT may be used as a simple and reliable predictor of MI-BCI performance. PMID:26736893

  11. Using motor imagery to study the neural substrates of dynamic balance.

    Directory of Open Access Journals (Sweden)

    Murielle Ursulla Ferraye

    Full Text Available This study examines the cerebral structures involved in dynamic balance using a motor imagery (MI protocol. We recorded cerebral activity with functional magnetic resonance imaging while subjects imagined swaying on a balance board along the sagittal plane to point a laser at target pairs of different sizes (small, large. We used a matched visual imagery (VI control task and recorded imagery durations during scanning. MI and VI durations were differentially influenced by the sway accuracy requirement, indicating that MI of balance is sensitive to the increased motor control necessary to point at a smaller target. Compared to VI, MI of dynamic balance recruited additional cortical and subcortical portions of the motor system, including frontal cortex, basal ganglia, cerebellum and mesencephalic locomotor region, the latter showing increased effective connectivity with the supplementary motor area. The regions involved in MI of dynamic balance were spatially distinct but contiguous to those involved in MI of gait (Bakker et al., 2008; Snijders et al., 2011; Crémers et al., 2012, in a pattern consistent with existing somatotopic maps of the trunk (for balance and legs (for gait. These findings validate a novel, quantitative approach for studying the neural control of balance in humans. This approach extends previous reports on MI of static stance (Jahn et al., 2004, 2008, and opens the way for studying gait and balance impairments in patients with neurodegenerative disorders.

  12. Classification of four-class motor imagery employing single-channel electroencephalography.

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    Sheng Ge

    Full Text Available With advances in brain-computer interface (BCI research, a portable few- or single-channel BCI system has become necessary. Most recent BCI studies have demonstrated that the common spatial pattern (CSP algorithm is a powerful tool in extracting features for multiple-class motor imagery. However, since the CSP algorithm requires multi-channel information, it is not suitable for a few- or single-channel system. In this study, we applied a short-time Fourier transform to decompose a single-channel electroencephalography signal into the time-frequency domain and construct multi-channel information. Using the reconstructed data, the CSP was combined with a support vector machine to obtain high classification accuracies from channels of both the sensorimotor and forehead areas. These results suggest that motor imagery can be detected with a single channel not only from the traditional sensorimotor area but also from the forehead area.

  13. Monitoring Local Regional Hemodynamic Signal Changes during Motor Execution and Motor Imagery Using Near-Infrared Spectroscopy

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    Naoki eIso

    2016-01-01

    Full Text Available The aim of this study was to clarify the topographical localization of motor-related regional hemodynamic signal changes during motor execution (ME and motor imagery (MI by using near-infrared spectroscopy (NIRS, as this technique is more clinically expedient than established methods (e.g. fMRI. Twenty right-handed healthy subjects participated in this study. The experimental protocol was a blocked design consisting of 3 cycles of 20 s of task performance and 30 s of rest. The tapping sequence task was performed with their fingers under 4 conditions: ME and MI with the right or left hand. Hemodynamic brain activity was measured with NIRS to monitor changes in oxygenated hemoglobin (oxy-Hb concentration. Oxy-Hb in the somatosensory motor cortex (SMC increased significantly only during contralateral ME and showed a significant interaction between task and hand. There was a main effect of hand in the left SMC. Although there were no significant main effects or interactions in the supplemental motor area (SMA and premotor area (PMA, oxy-Hb increased substantially under all conditions. These results clarified the topographical localization by motor-related regional hemodynamic signal changes during ME and MI by using NIRS.

  14. BRAIN-COMPUTER-INTERFACE – SUPPORTED MOTOR IMAGERY TRAININTG FOR PATIENTS WITH HEMIPARESIS

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    O. A. Mokienko

    2013-01-01

    Full Text Available The aim of study was to assess the feasibility of motor imagery supported brain-computer interface in patients with hemiparesis. 13 patients with central paresis of the hand and 15 healthy volunteers were learning to control EEG-based interface with feedback. No differences on interface control quality were found between patients and healthy subjects. The trainings were accompanied by the desynchronization of sensorimotor rhythm. In patients with cortical damage the source of EEG-activity was dislocated.

  15. A neural network-based optimal spatial filter design method for motor imagery classification.

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    Ayhan Yuksel

    Full Text Available In this study, a novel spatial filter design method is introduced. Spatial filtering is an important processing step for feature extraction in motor imagery-based brain-computer interfaces. This paper introduces a new motor imagery signal classification method combined with spatial filter optimization. We simultaneously train the spatial filter and the classifier using a neural network approach. The proposed spatial filter network (SFN is composed of two layers: a spatial filtering layer and a classifier layer. These two layers are linked to each other with non-linear mapping functions. The proposed method addresses two shortcomings of the common spatial patterns (CSP algorithm. First, CSP aims to maximize the between-classes variance while ignoring the minimization of within-classes variances. Consequently, the features obtained using the CSP method may have large within-classes variances. Second, the maximizing optimization function of CSP increases the classification accuracy indirectly because an independent classifier is used after the CSP method. With SFN, we aimed to maximize the between-classes variance while minimizing within-classes variances and simultaneously optimizing the spatial filter and the classifier. To classify motor imagery EEG signals, we modified the well-known feed-forward structure and derived forward and backward equations that correspond to the proposed structure. We tested our algorithm on simple toy data. Then, we compared the SFN with conventional CSP and its multi-class version, called one-versus-rest CSP, on two data sets from BCI competition III. The evaluation results demonstrate that SFN is a good alternative for classifying motor imagery EEG signals with increased classification accuracy.

  16. Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players

    OpenAIRE

    Aymeric Guillot; Franck Di Rienzo; Vincent Pialoux; Germain Simon; Sarah Skinner; Isabelle Rogowski

    2015-01-01

    The aim of this study was to investigate the effects of implementing motor imagery (MI) during specific tennis high intensity intermittent training (HIIT) sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included ver...

  17. An Algorithm for Idle-State Detection in Motor-Imagery-Based Brain-Computer Interface

    OpenAIRE

    Yijun Wang; Dan Zhang; Xiaorong Gao; Bo Hong; Shangkai Gao

    2007-01-01

    For a robust brain-computer interface (BCI) system based on motor imagery (MI), it should be able to tell when the subject is not concentrating on MI tasks (the “idle state”) so that real MI tasks could be extracted accurately. Moreover, because of the diversity of idle state, detecting idle state without training samples is as important as classifying MI tasks. In this paper, we propose an algorithm for solving this ...

  18. Cognitive alterations in motor imagery process after left hemispheric ischemic stroke.

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    Jing Yan

    Full Text Available BACKGROUND: Motor imagery training is a promising rehabilitation strategy for stroke patients. However, few studies had focused on the neural mechanisms in time course of its cognitive process. This study investigated the cognitive alterations after left hemispheric ischemic stroke during motor imagery task. METHODOLOGY/PRINCIPAL FINDINGS: Eleven patients with ischemic stroke in left hemisphere and eleven age-matched control subjects participated in mental rotation task (MRT of hand pictures. Behavior performance, event-related potential (ERP and event-related (desynchronization (ERD/ERS in beta band were analyzed to investigate the cortical activation. We found that: (1 The response time increased with orientation angles in both groups, called "angle effect", however, stoke patients' responses were impaired with significantly longer response time and lower accuracy rate; (2 In early visual perceptual cognitive process, stroke patients showed hypo-activations in frontal and central brain areas in aspects of both P200 and ERD; (3 During mental rotation process, P300 amplitude in control subjects decreased while angle increased, called "amplitude modulation effect", which was not observed in stroke patients. Spatially, patients showed significant lateralization of P300 with activation only in contralesional (right parietal cortex while control subjects showed P300 in both parietal lobes. Stroke patients also showed an overall cortical hypo-activation of ERD during this sub-stage; (4 In the response sub-stage, control subjects showed higher ERD values with more activated cortical areas particularly in the right hemisphere while angle increased, named "angle effect", which was not observed in stroke patients. In addition, stroke patients showed significant lower ERD for affected hand (right response than that for unaffected hand. CONCLUSIONS/SIGNIFICANCE: Cortical activation was altered differently in each cognitive sub-stage of motor imagery after

  19. 4-CLASS MOTOR IMAGERY CLASSIFICATION FOR POST STROKE REHABILITATION USING BRAIN-COMPUTER INTERFACE

    OpenAIRE

    Aarathi Kumar*, Nisha. P. V

    2016-01-01

    Brain-Computer Interface (BCI) is a mechanism that helps in the control/communication of one’s environment through the brain signals obtained directly from the brain via an EEG signal acquisition unit. A BCI incorporating Motor Imagery for post-stroke rehabilitation of upper limbs and knee in fully disabled patients is designed. It helps in restoring some of the activities of the daily living. It aids post-stroke sufferers to carry out functionalities like movement of right an...

  20. Real-Time Brain-Computer Interface System Based on Motor Imagery

    Institute of Scientific and Technical Information of China (English)

    Tie-Jun Liu; Ping Yang; Xu-Yong Peng; Yu Huang; De-Zhong Yao

    2009-01-01

    A brain-computer interface (BCI) real-time system based on motor imagery translates the user's motor intention into a real-time control signal for peripheral equipments.A key problem to be solved for practical applications is real-time data collection and processing.In this paper,a real-time BCI system is implemented on computer with electroencephalogram amplifier.In our implementation,the on-line voting method is adopted for feedback control strategy,and the voting results are used to control the cursor horizontal movement.Three subjects take part in the experiment.The results indicate that the best accuracy is 90%.

  1. Effect of Motor Imagery on the F-Wave Parameters in Hemiparetic Stroke Survivors

    OpenAIRE

    Naseri, Mahshid; Petramfar, Peyman; Ashraf, Alireza

    2015-01-01

    Objective To assess the effect of motor imagery, as a rehabilitation method in stroke, on F-wave parameters that undergo changes during upper motor neuron involvement. Methods Twenty-one fully conscious hemiparetic stroke survivors with a completely plegic hand (power 0/5) and a minimum interval of 72 hours since stroke were recruited into this study. The mean F-wave latency, amplitude, and persistence in the median and ulnar nerves were measured in both the affected and non-affected sides at...

  2. A Wearable Channel Selection-Based Brain-Computer Interface for Motor Imagery Detection.

    Science.gov (United States)

    Lo, Chi-Chun; Chien, Tsung-Yi; Chen, Yu-Chun; Tsai, Shang-Ho; Fang, Wai-Chi; Lin, Bor-Shyh

    2016-02-06

    Motor imagery-based brain-computer interface (BCI) is a communication interface between an external machine and the brain. Many kinds of spatial filters are used in BCIs to enhance the electroencephalography (EEG) features related to motor imagery. The approach of channel selection, developed to reserve meaningful EEG channels, is also an important technique for the development of BCIs. However, current BCI systems require a conventional EEG machine and EEG electrodes with conductive gel to acquire multi-channel EEG signals and then transmit these EEG signals to the back-end computer to perform the approach of channel selection. This reduces the convenience of use in daily life and increases the limitations of BCI applications. In order to improve the above issues, a novel wearable channel selection-based brain-computer interface is proposed. Here, retractable comb-shaped active dry electrodes are designed to measure the EEG signals on a hairy site, without conductive gel. By the design of analog CAR spatial filters and the firmware of EEG acquisition module, the function of spatial filters could be performed without any calculation, and channel selection could be performed in the front-end device to improve the practicability of detecting motor imagery in the wearable EEG device directly or in commercial mobile phones or tablets, which may have relatively low system specifications. Finally, the performance of the proposed BCI is investigated, and the experimental results show that the proposed system is a good wearable BCI system prototype.

  3. A Wearable Channel Selection-Based Brain-Computer Interface for Motor Imagery Detection

    Directory of Open Access Journals (Sweden)

    Chi-Chun Lo

    2016-02-01

    Full Text Available Motor imagery-based brain-computer interface (BCI is a communication interface between an external machine and the brain. Many kinds of spatial filters are used in BCIs to enhance the electroencephalography (EEG features related to motor imagery. The approach of channel selection, developed to reserve meaningful EEG channels, is also an important technique for the development of BCIs. However, current BCI systems require a conventional EEG machine and EEG electrodes with conductive gel to acquire multi-channel EEG signals and then transmit these EEG signals to the back-end computer to perform the approach of channel selection. This reduces the convenience of use in daily life and increases the limitations of BCI applications. In order to improve the above issues, a novel wearable channel selection-based brain-computer interface is proposed. Here, retractable comb-shaped active dry electrodes are designed to measure the EEG signals on a hairy site, without conductive gel. By the design of analog CAR spatial filters and the firmware of EEG acquisition module, the function of spatial filters could be performed without any calculation, and channel selection could be performed in the front-end device to improve the practicability of detecting motor imagery in the wearable EEG device directly or in commercial mobile phones or tablets, which may have relatively low system specifications. Finally, the performance of the proposed BCI is investigated, and the experimental results show that the proposed system is a good wearable BCI system prototype.

  4. Evaluation of Methods for Estimating Fractal Dimension in Motor Imagery-Based Brain Computer Interface

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    Chu Kiong Loo

    2011-01-01

    Full Text Available A brain computer interface BCI enables direct communication between a brain and a computer translating brain activity into computer commands using preprocessing, feature extraction, and classification operations. Feature extraction is crucial, as it has a substantial effect on the classification accuracy and speed. While fractal dimension has been successfully used in various domains to characterize data exhibiting fractal properties, its usage in motor imagery-based BCI has been more recent. In this study, commonly used fractal dimension estimation methods to characterize time series Katz's method, Higuchi's method, rescaled range method, and Renyi's entropy were evaluated for feature extraction in motor imagery-based BCI by conducting offline analyses of a two class motor imagery dataset. Different classifiers fuzzy k-nearest neighbours FKNN, support vector machine, and linear discriminant analysis were tested in combination with these methods to determine the methodology with the best performance. This methodology was then modified by implementing the time-dependent fractal dimension TDFD, differential fractal dimension, and differential signals methods to determine if the results could be further improved. Katz's method with FKNN resulted in the highest classification accuracy of 85%, and further improvements by 3% were achieved by implementing the TDFD method.

  5. Flying across Galaxy Clusters with Google Earth: additional imagery from SDSS co-added data

    International Nuclear Information System (INIS)

    Galaxy clusters are spectacular. We provide a Google Earth compatible imagery for the deep co-added images from the Sloan Digital Sky Survey and make it a tool for examing galaxy clusters. Google Earth (in sky mode) provides a highly interactive environment for visualizing the sky. By encoding the galaxy cluster information into a kml/kmz file, one can use Google Earth as a tool for examining galaxy clusters and fly across them freely. However, the resolution of the images provided by Google Earth is not very high. This is partially because the major imagery google earth used is from Sloan Digital Sky Survey (SDSS) (SDSS collaboration 2000) and the resolutions have been reduced to speed up the web transferring. To have higher resolution images, you need to add your own images in a way that Google Earth can understand. The SDSS co-added data are the co-addition of ∼100 scans of images from SDSS stripe 82 (Annis et al. 2010). It provides the deepest images based on SDSS and reach as deep as about redshift 1.0. Based on the co-added images, we created color images in a way as described by Lupton et al. (2004) and convert the color images to Google Earth compatible images using wcs2kml (Brewer et al. 2007). The images are stored at a public server at Fermi National Accelerator Laboratory and can be accessed by the public. To view those images in Google Earth, you need to download a kmz file, which contains the links to the color images, and then open the kmz file with your Google Earth. To meet different needs for resolutions, we provide three kmz files corresponding to low, medium and high resolution images. We recommend the high resolution one as long as you have a broadband Internet connection, though you should choose to download any of them, depending on your own needs and Internet speed. After you open the downloaded kmz file with Google Earth (in sky mode), it takes about 5 minutes (depending on your Internet connection and the resolution of images you want

  6. Modulation of mu rhythm desynchronization during motor imagery by transcranial direct current stimulation

    Directory of Open Access Journals (Sweden)

    Kimura Akio

    2010-06-01

    Full Text Available Abstract Background The mu event-related desynchronization (ERD is supposed to reflect motor preparation and appear during motor imagery. The aim of this study is to examine the modulation of ERD with transcranial direct current stimulation (tDCS. Methods Six healthy subjects were asked to imagine their right hand grasping something after receiving a visual cue. Electroencephalograms (EEGs were recorded near the left M1. ERD of the mu rhythm (mu ERD by right hand motor imagery was measured. tDCS (10 min, 1 mA was used to modulate the cortical excitability of M1. Anodal, cathodal, and sham tDCS were tested in each subject with a randomized sequence on different days. Each condition was separated from the preceding one by more than 1 week in the same subject. Before and after tDCS, mu ERD was assessed. The motor thresholds (MT of the left M1 were also measured with transcranial magnetic stimulation. Results Mu ERD significantly increased after anodal stimulation, whereas it significantly decreased after cathodal stimulation. There was a significant correlation between mu ERD and MT. Conclusions Opposing effects on mu ERD based on the orientation of the stimulation suggest that mu ERD is affected by cortical excitability.

  7. Robot-Aided Upper-Limb Rehabilitation Based on Motor Imagery EEG

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    Baoguo Xu

    2011-09-01

    Full Text Available Stroke is a leading cause of disability worldwide. In this paper, a novel robot‐assisted rehabilitation system based on motor imagery electroencephalography (EEG is developed for regular training of neurological rehabilitation for upper limb stroke patients. Firstly, three‐dimensional animation was used to guide the patient image the upper limb movement and EEG signals were acquired by EEG amplifier. Secondly, eigenvectors were extracted by harmonic wavelet transform (HWT and linear discriminant analysis (LDA classifier was utilized to classify the pattern of the left and right upper limb motor imagery EEG signals. Finally, PC triggered the upper limb rehabilitation robot to perform motor therapy and gave the virtual feedback. Using this robot‐assisted upper limb rehabilitation system, the patientʹs EEG of upper limb movement imagination is translated to control rehabilitation robot directly. Consequently, the proposed rehabilitation system can fully explore the patientʹs motivation and attention and directly facilitate upper limb post‐stroke rehabilitation therapy. Experimental results on unimpaired participants were presented to demonstrate the feasibility of the rehabilitation system. Combining robot‐assisted training with motor imagery‐ based BCI will make future rehabilitation therapy more effective. Clinical testing is still required for further proving this assumption.

  8. Adaptive Stacked Generalization for Multiclass Motor Imagery-Based Brain Computer Interfaces.

    Science.gov (United States)

    Nicolas-Alonso, Luis F; Corralejo, Rebeca; Gomez-Pilar, Javier; Álvarez, Daniel; Hornero, Roberto

    2015-07-01

    Practical motor imagery-based brain computer interface (MI-BCI) applications are limited by the difficult to decode brain signals in a reliable way. In this paper, we propose a processing framework to address non-stationarity, as well as handle spectral, temporal, and spatial characteristics associated with execution of motor tasks. Stacked generalization is used to exploit the power of classifier ensembles for combining information coming from multiple sources and reducing the existing uncertainty in EEG signals. The outputs of several regularized linear discriminant analysis (RLDA) models are combined to account for temporal, spatial, and spectral information. The resultant algorithm is called stacked RLDA (SRLDA). Additionally, an adaptive processing stage is introduced before classification to reduce the harmful effect of intersession non-stationarity. The benefits of the proposed method are evaluated on the BCI Competition IV dataset 2a. We demonstrate its effectiveness in binary and multiclass settings with four different motor imagery tasks: left-hand, right-hand, both feet, and tongue movements. The results show that adaptive SRLDA outperforms the winner of the competition and other approaches tested on this multiclass dataset.

  9. Motor imagery modality in expert dancers: an investigation of hip and pelvis kinematics in demi-plié and sauté.

    Science.gov (United States)

    Coker, Elizabeth; McIsaac, Tara L; Nilsen, Dawn

    2015-06-01

    Elite dancers often engage in mental practice during training, but little is known about the effects of discrete, repetitive motor imagery on dance movement performance. This study compared the effects of two motor imagery modalities, third-person visual imagery and kinesthetic imagery, on hip and pelvis kinematics during two technical dance movements, plié and sauté. Twenty-four female dancers (mean age: 26.04; mean years of training: 19.63) were randomly assigned to a type of imagery practice: visual imagery (VI), kinesthetic imagery (KI), or a mental arithmetic task control condition (MAT). No statistically significant effects of imagery group or task type were found for external hip rotation, sagittal pelvic excursion, or a ratio relating hip to pelvic movement, suggesting that imagery practice did not affect either temporal or kinematic characteristics of the plié or sauté. PMID:26045397

  10. Functional Magnetic Resonance Imaging Neurofeedback-guided Motor Imagery Training and Motor Training for Parkinson’s Disease: Randomized Trial

    Science.gov (United States)

    Subramanian, Leena; Morris, Monica Busse; Brosnan, Meadhbh; Turner, Duncan L.; Morris, Huw R.; Linden, David E. J.

    2016-01-01

    Objective: Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback (NF) uses feedback of the patient’s own brain activity to self-regulate brain networks which in turn could lead to a change in behavior and clinical symptoms. The objective was to determine the effect of NF and motor training (MOT) alone on motor and non-motor functions in Parkinson’s Disease (PD) in a 10-week small Phase I randomized controlled trial. Methods: Thirty patients with Parkinson’s disease (PD; Hoehn and Yahr I-III) and no significant comorbidity took part in the trial with random allocation to two groups. Group 1 (NF: 15 patients) received rt-fMRI-NF with MOT. Group 2 (MOT: 15 patients) received MOT alone. The primary outcome measure was the Movement Disorder Society—Unified PD Rating Scale-Motor scale (MDS-UPDRS-MS), administered pre- and post-intervention “off-medication”. The secondary outcome measures were the “on-medication” MDS-UPDRS, the PD Questionnaire-39, and quantitative motor assessments after 4 and 10 weeks. Results: Patients in the NF group were able to upregulate activity in the supplementary motor area (SMA) by using motor imagery. They improved by an average of 4.5 points on the MDS-UPDRS-MS in the “off-medication” state (95% confidence interval: −2.5 to −6.6), whereas the MOT group improved only by 1.9 points (95% confidence interval +3.2 to −6.8). The improvement in the intervention group meets the minimal clinically important difference which is also on par with other non-invasive therapies such as repetitive Transcranial Magnetic Stimulation (rTMS). However, the improvement did not differ significantly between the groups. No adverse events were reported in either group. Interpretation: This Phase I study suggests that NF combined with MOT is safe and improves motor symptoms immediately after treatment, but larger trials are needed to explore its superiority over active control conditions. PMID:27375451

  11. Motor Imagery and Its Effect on Complex Regional Pain Syndrome: An Integrative Review

    Science.gov (United States)

    de Souza, Nélio Silva; Martins, Ana Carolina Gomes; Bastos, Victor Hugo do Vale; Leite, Marco Antônio A.; Teixeira, Silmar; Velasques, Bruna; Ribeiro, Pedro; Bittencourt, Juliana; Matta, André Palma da Cunha; Filho, Pedro Moreira

    2015-01-01

    The motor imagery (MI) has been proposed as a treatment in the complex regional pain syndrome type 1 (CRPS-1), since it seems to promote a brain reorganization effect on sensory-motor areas of pain perception. The aim of this paper is to investigate, through an integrative critical review, the influence of MI on the CRPS-1, correlating their evidence to clinical practice. Research in PEDro, Medline, Bireme and Google Scholar databases was conducted. Nine randomized controlled trials (level 2), 1 non-controlled clinical study (level 3), 1 case study (level 4), 1 systematic review (level 1), 2 review articles and 1 comment (level 5) were found. We can conclude that MI has shown effect in reducing pain and functionality that remains after 6 months of treatment. However, the difference between the MI strategies for CRPS-1 is unknown as well as the intensity of mental stress influences the painful response or effect of MI or other peripheral neuropathies. PMID:26788264

  12. Bipolar electrode selection for a motor imagery based brain computer interface

    Science.gov (United States)

    Lou, Bin; Hong, Bo; Gao, Xiaorong; Gao, Shangkai

    2008-09-01

    A motor imagery based brain-computer interface (BCI) provides a non-muscular communication channel that enables people with paralysis to control external devices using their motor imagination. Reducing the number of electrodes is critical to improving the portability and practicability of the BCI system. A novel method is proposed to reduce the number of electrodes to a total of four by finding the optimal positions of two bipolar electrodes. Independent component analysis (ICA) is applied to find the source components of mu and alpha rhythms, and optimal electrodes are chosen by comparing the projection weights of sources on each channel. The results of eight subjects demonstrate the better classification performance of the optimal layout compared with traditional layouts, and the stability of this optimal layout over a one week interval was further verified.

  13. Motor imagery and its effect on complex regional pain syndrome: an integrative review

    Directory of Open Access Journals (Sweden)

    Nélio Silva de Souza

    2015-12-01

    Full Text Available The motor imagery (MI has been proposed as a treatment in the complex regional pain syndrome type 1 (CRPS-1, since it seems to promote a brain reorganization effect on sensory- motor areas of pain perception. The aim of this paper is to investigate, through an integrative critical review, the influence of MI on the CRPS-1, correlating their evidence to clinical practice. Research in PEDro, Medline, Bireme and Google Scholar databases was conducted. Nine randomized controlled trials (level 2, 1 non-controlled clinical study (level 3, 1 case study (level 4, 1 systematic review (level 1, 2 review articles and 1 comment (level 5 were found. We can conclude that MI has shown effect in reducing pain and functionality that remains after 6 months of treatment. However, the difference between the MI strategies for CRPS-1 is unknown as well as the intensity of mental stress influences the painful response or effect of MI or other peripheral neuropathies.

  14. Testing the Self-Similarity Exponent to Feature Extraction in Motor Imagery Based Brain Computer Interface Systems

    Science.gov (United States)

    Rodríguez-Bermúdez, Germán; Sánchez-Granero, Miguel Ángel; García-Laencina, Pedro J.; Fernández-Martínez, Manuel; Serna, José; Roca-Dorda, Joaquín

    2015-12-01

    A Brain Computer Interface (BCI) system is a tool not requiring any muscle action to transmit information. Acquisition, preprocessing, feature extraction (FE), and classification of electroencephalograph (EEG) signals constitute the main steps of a motor imagery BCI. Among them, FE becomes crucial for BCI, since the underlying EEG knowledge must be properly extracted into a feature vector. Linear approaches have been widely applied to FE in BCI, whereas nonlinear tools are not so common in literature. Thus, the main goal of this paper is to check whether some Hurst exponent and fractal dimension based estimators become valid indicators to FE in motor imagery BCI. The final results obtained were not optimal as expected, which may be due to the fact that the nature of the analyzed EEG signals in these motor imagery tasks were not self-similar enough.

  15. Discrimination of Motor Imagery-Induced EEG Patterns in Patients with Complete Spinal Cord Injury

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    G. Pfurtscheller

    2009-01-01

    Full Text Available EEG-based discrimination between different motor imagery states has been subject of a number of studies in healthy subjects. We investigated the EEG of 15 patients with complete spinal cord injury during imagined right hand, left hand, and feet movements. In detail we studied pair-wise discrimination functions between the 3 types of motor imagery. The following classification accuracies (mean ± SD were obtained: left versus right hand 65.03% ± 8.52, left hand versus feet 68.19% ± 11.08, and right hand versus feet 65.05% ± 9.25. In 5 out of 8 paralegic patients, the discrimination accuracy was greater than 70% but in only 1 out of 7 tetraplagic patients. The present findings provide evidence that in the majority of paraplegic patients an EEG-based BCI could achieve satisfied results. In tetraplegic patients, however, it is expected that extensive training-sessions are necessary to achieve a good BCI performance at least in some subjects.

  16. When music tempo affects the temporal congruence between physical practice and motor imagery.

    Science.gov (United States)

    Debarnot, Ursula; Guillot, Aymeric

    2014-06-01

    When people listen to music, they hear beat and a metrical structure in the rhythm; these perceived patterns enable coordination with the music. A clear correspondence between the tempo of actual movement (e.g., walking) and that of music has been demonstrated, but whether similar coordination occurs during motor imagery is unknown. Twenty participants walked naturally for 8m, either physically or mentally, while listening to slow and fast music, or not listening to anything at all (control condition). Executed and imagined walking times were recorded to assess the temporal congruence between physical practice (PP) and motor imagery (MI). Results showed a difference when comparing slow and fast time conditions, but each of these durations did not differ from soundless condition times, hence showing that body movement may not necessarily change in order to synchronize with music. However, the main finding revealed that the ability to achieve temporal congruence between PP and MI times was altered when listening to either slow or fast music. These data suggest that when physical movement is modulated with respect to the musical tempo, the MI efficacy of the corresponding movement may be affected by the rhythm of the music. Practical applications in sport are discussed as athletes frequently listen to music before competing while they mentally practice their movements to be performed. PMID:24681309

  17. Motor imagery in Asperger syndrome: testing action simulation by the hand laterality task.

    Directory of Open Access Journals (Sweden)

    Massimiliano Conson

    Full Text Available Asperger syndrome (AS is a neurodevelopmental condition within the Autism Spectrum Disorders (ASD characterized by specific difficulties in social interaction, communication and behavioural control. In recent years, it has been suggested that ASD is related to a dysfunction of action simulation processes, but studies employing imitation or action observation tasks provided mixed results. Here, we addressed action simulation processes in adolescents with AS by means of a motor imagery task, the classical hand laterality task (to decide whether a rotated hand image is left or right; mental rotation of letters was also evaluated. As a specific marker of action simulation in hand rotation, we assessed the so-called biomechanical effect, that is the advantage for judging hand pictures showing physically comfortable versus physically awkward positions. We found the biomechanical effect in typically-developing participants but not in participants with AS. Overall performance on both hand laterality and letter rotation tasks, instead, did not differ in the two groups. These findings demonstrated a specific alteration of motor imagery skills in AS. We suggest that impaired mental simulation and imitation of goal-less movements in ASD could be related to shared cognitive mechanisms.

  18. A standardized motor imagery introduction program (MIIP for neuro-rehabilitation: development and evaluation

    Directory of Open Access Journals (Sweden)

    Christine eWondrusch

    2013-08-01

    Full Text Available Background: For patients with central nervous system lesions and sensorimotor impairments a solid motor imagery (MI introduction is crucial to understand and use MI to improve motor performance. The study’s aim was to develop and evaluate a standardized MI group introduction program (MIIP for patients after stroke, multiple sclerosis, Parkinson’s disease, and traumatic brain injury. Methods:Phase 1: Based on literature a MIIP was developed comprising MI theory (definition, type, mode, perspective, planning and MI practice (performance, control. Phase 2: Development of a 27-item self-administered MIIP evaluation questionnaire, assessing MI knowledge self-evaluation of the ability to perform MI and patient satisfaction with the MIIP. Phase 3: Evaluation of MIIP and MI questionnaire by 2 independent MI experts based on predefined criteria and 2 patients using semi-structured interviews.Phase 4: Case series with a pre-post design to evaluate MIIP (3x30minutes using the MI questionnaire, Imaprax, Kinaesthetic and Visual Imagery Questionnaire, and Mental Chronometry. The paired t-test and the Wilcoxon signed-rank test were used to determine significant changes.Results: Data of eleven patients were analysed (5 females; age 62.3±14.1 years. Declarative MI knowledge improved significantly from 5.4±2.2 to 8.8±2.9 (p=0.010. Patients demonstrated good satisfaction with MIIP (mean satisfaction score: 83.2±11.4 %. MI ability remained on a high level but showed no significant change, except a significant decrease in the Kinaesthetic and Visual Imagery Questionnaire score.Conclusion: The presented MIIP seems to be valid and feasible for patients with central nervous system lesions and sensorimotor impairments resulting in improved MI knowledge. MIIP sessions can be held in groups of four or less. MI ability and Mental Chronometry remained unchanged after 3 training sessions.

  19. Brain oscillatory activity during motor imagery in EEG-fMRI coregistration.

    Science.gov (United States)

    Formaggio, Emanuela; Storti, Silvia Francesca; Cerini, Roberto; Fiaschi, Antonio; Manganotti, Paolo

    2010-12-01

    The purpose of the present work was to investigate the correlation between topographical changes in brain oscillatory activity and the blood oxygenation level-dependent (BOLD) signal during a motor imagery (MI) task using electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) coregistration. EEG was recorded in 7 healthy subjects inside a 1.5 T MR scanner during the imagination of the kinesthetic experience of movement. A Fast Fourier Transform was applied to EEG signal in the rest and active conditions. We used the event-related-synchronization (ERS)/desynchronization (ERD) approach to characterize where the imagination of movement produces a decrease in alpha and beta power. The mean alpha map showed ERD decrease localized over the contralateral sensory motor area (SM1c) and a light desynchronization in the ipsilateral sensory motor area (SM1i); whereas the mean beta map showed ERD decrease over the supplementary motor area (SMA). fMRI showed significant activation in SMA, SM1c, SM1i. The correlation is negative in the contralateral side and positive in the ipsilateral side. Using combined EEG-fMRI signals we obtained useful new information on the description of the changes in oscillatory activity in alpha and beta bands during MI and on the investigation of the sites of BOLD activity as possible sources in generating these rhythms. By correlating BOLD and ERD/ERS we may identify more accurately which regions contribute to changes of the electrical response. PMID:20850237

  20. Adaptive Motor Imagery: A Multimodal Study of Immobilization-Induced Brain Plasticity.

    Science.gov (United States)

    Burianová, Hana; Sowman, Paul F; Marstaller, Lars; Rich, Anina N; Williams, Mark A; Savage, Greg; Al-Janabi, Shahd; de Lissa, Peter; Johnson, Blake W

    2016-03-01

    The consequences of losing the ability to move a limb are traumatic. One approach that examines the impact of pathological limb nonuse on the brain involves temporary immobilization of a healthy limb. Here, we investigated immobilization-induced plasticity in the motor imagery (MI) circuitry during hand immobilization. We assessed these changes with a multimodal paradigm, using functional magnetic resonance imaging (fMRI) to measure neural activation, magnetoencephalography (MEG) to track neuronal oscillatory dynamics, and transcranial magnetic stimulation (TMS) to assess corticospinal excitability. fMRI results show a significant decrease in neural activation for MI of the constrained hand, localized to sensorimotor areas contralateral to the immobilized hand. MEG results show a significant decrease in beta desynchronization and faster resynchronization in sensorimotor areas contralateral to the immobilized hand. TMS results show a significant increase in resting motor threshold in motor cortex contralateral to the constrained hand, suggesting a decrease in corticospinal excitability in the projections to the constrained hand. These results demonstrate a direct and rapid effect of immobilization on MI processes of the constrained hand, suggesting that limb nonuse may not only affect motor execution, as evidenced by previous studies, but also MI. These findings have important implications for the effectiveness of therapeutic approaches that use MI as a rehabilitation tool to ameliorate the negative effects of limb nonuse. PMID:25477368

  1. How feedback, motor imagery, and reward influence brain self-regulation using real-time fMRI.

    Science.gov (United States)

    Sepulveda, Pradyumna; Sitaram, Ranganatha; Rana, Mohit; Montalba, Cristian; Tejos, Cristian; Ruiz, Sergio

    2016-09-01

    The learning process involved in achieving brain self-regulation is presumed to be related to several factors, such as type of feedback, reward, mental imagery, duration of training, among others. Explicitly instructing participants to use mental imagery and monetary reward are common practices in real-time fMRI (rtfMRI) neurofeedback (NF), under the assumption that they will enhance and accelerate the learning process. However, it is still not clear what the optimal strategy is for improving volitional control. We investigated the differential effect of feedback, explicit instructions and monetary reward while training healthy individuals to up-regulate the blood-oxygen-level dependent (BOLD) signal in the supplementary motor area (SMA). Four groups were trained in a two-day rtfMRI-NF protocol: GF with NF only, GF,I with NF + explicit instructions (motor imagery), GF,R with NF + monetary reward, and GF,I,R with NF + explicit instructions (motor imagery) + monetary reward. Our results showed that GF increased significantly their BOLD self-regulation from day-1 to day-2 and GF,R showed the highest BOLD signal amplitude in SMA during the training. The two groups who were instructed to use motor imagery did not show a significant learning effect over the 2 days. The additional factors, namely motor imagery and reward, tended to increase the intersubject variability in the SMA during the course of training. Whole brain univariate and functional connectivity analyses showed common as well as distinct patterns in the four groups, representing the varied influences of feedback, reward, and instructions on the brain. Hum Brain Mapp 37:3153-3171, 2016. © 2016 Wiley Periodicals, Inc. PMID:27272616

  2. Assessing the feasibility of time-resolved fNIRS to detect brain activity during motor imagery

    Science.gov (United States)

    Abdalmalak, Androu; Milej, Daniel; Diop, Mamadou; Naci, Lorina; Owen, Adrian M.; St. Lawrence, Keith

    2016-03-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive optical technique for detecting brain activity, which has been previously used during motor and motor executive tasks. There is an increasing interest in using fNIRS as a brain computer interface (BCI) for patients who lack the physical, but not the mental, ability to respond to commands. The goal of this study is to assess the feasibility of time-resolved fNIRS to detect brain activity during motor imagery. Stability tests were conducted to ensure the temporal stability of the signal, and motor imagery data were acquired on healthy subjects. The NIRS probes were placed on the scalp over the premotor cortex (PMC) and supplementary motor area (SMA), as these areas are responsible for motion planning. To confirm the fNIRS results, subjects underwent functional magnetic resonance imaging (fMRI) while performing the same task. Seven subjects have participated to date, and significant activation in the SMA and/or the PMC during motor imagery was detected by both fMRI and fNIRS in 4 of the 7 subjects. No activation was detected by either technique in the remaining three participants, which was not unexpected due to the nature of the task. The agreement between the two imaging modalities highlights the potential of fNIRS as a BCI, which could be adapted for bedside studies of patients with disorders of consciousness.

  3. Feature combination for classifying single-trial ECoG during motor imagery of different sessions

    Institute of Scientific and Technical Information of China (English)

    Wei Qingguo; Meng Fei; Wang Yijun; Gao Xiaorong; Gao Shangkai

    2007-01-01

    The input signals of brain-computer interfaces (BCIs) may be either scalp electroencephalogram (EEG) or electrocorticogram (ECoG) recorded from subdural electrodes. To make BCIs practical, the classifiers for discriminating different brain states must have the ability of session-to-session transfer. This paper proposes an algorithm for classifying single-trial ECoG during motor imagery of different sessions. Three features, derived from two physiological phenomena, movement-related potentials (MRP) and event-related desynchronization (ERD), and extracted by common spatial subspace decomposition (CSSD) and waveform mean, are combined to perform classification tasks. The specific signal processing methods utilized are described in detail. The algorithm was successfully applied to Data Set I of BCI Competition Ⅲ, and achieved a classification accuracy of 91% on test set.

  4. Time sparsification of EEG signals in motor-imagery based brain computer interfaces.

    Science.gov (United States)

    Higashi, Hiroshi; Tanaka, Toshihisa

    2012-01-01

    We propose a method of sparsifying EEG signals in the time domain for common spatial patterns (CSP) which are often used for feature extraction in brain computer interfaces (BCI). For accurate classification, it is important to analyze the period of time when a BCI user performs a mental task. We address this problem by optimizing the CSP cost with a time sparsification that removes unnecessary samples from the classification. We design a cost function that has CSP spatial weights and time window as optimization parameters. To find these parameters, we use alternating optimization. In an experiment on classification of motor-imagery EEG signals, the proposed method increased classification accuracy by 6% averaged over five subjects.

  5. Quaternion-Based Signal Analysis for Motor Imagery Classification from Electroencephalographic Signals

    Directory of Open Access Journals (Sweden)

    Patricia Batres-Mendoza

    2016-03-01

    Full Text Available Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA to represent EEG signals obtained using a brain-computer interface (BCI device to detect and interpret cognitive activity. This quaternion-based signal analysis technique can extract features to represent brain activity related to motor imagery accurately in various mental states. Experimental tests in which users where shown visual graphical cues related to left and right movements were used to collect BCI-recorded signals. These signals were then classified using decision trees (DT, support vector machine (SVM and k-nearest neighbor (KNN techniques. The quantitative analysis of the classifiers demonstrates that this technique can be used as an alternative in the EEG-signal modeling phase to identify mental states.

  6. Investigating brief motor imagery for an ERD/ERS based BCI.

    Science.gov (United States)

    Thomas, Eoin; Fruitet, Joan; Clerc, Maureen

    2012-01-01

    This study establishes the effectiveness of event related synchronisation (ERS) features for a system paced brain computer interface (BCI). In particular, the relationship between the duration of motor imagery (MI) and the quality of the features extracted from the ERS is investigated. To this end, two groups of users performed brief (2s) or sustained (4s) MI, and offline single trial BCIs were validated on each group based on features extracted from the EEG before, during and after MI. The BCIs were designed to recognise two intentional control tasks and a no-control state. Cross-validated results indicate that brief MI leads to more informative ERS features than sustained MI. PMID:23366538

  7. Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players

    Science.gov (United States)

    Guillot, Aymeric; Di Rienzo, Franck; Pialoux, Vincent; Simon, Germain; Skinner, Sarah; Rogowski, Isabelle

    2015-01-01

    The aim of this study was to investigate the effects of implementing motor imagery (MI) during specific tennis high intensity intermittent training (HIIT) sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included verbal encouragements for physical efforts and served as control condition. Results revealed that similar cardiac demand was observed during both sessions, while implementing MI maintained groundstroke accuracy. Embedding MI during HIIT enabled the development of physical fitness and the preservation of stroke performance. These findings bring new insight to tennis and conditioning coaches in order to fulfil the benefits of specific playing HIIT sessions, and therefore to optimise the training time. PMID:26580804

  8. Quaternion-Based Signal Analysis for Motor Imagery Classification from Electroencephalographic Signals.

    Science.gov (United States)

    Batres-Mendoza, Patricia; Montoro-Sanjose, Carlos R; Guerra-Hernandez, Erick I; Almanza-Ojeda, Dora L; Rostro-Gonzalez, Horacio; Romero-Troncoso, Rene J; Ibarra-Manzano, Mario A

    2016-01-01

    Quaternions can be used as an alternative to model the fundamental patterns of electroencephalographic (EEG) signals in the time domain. Thus, this article presents a new quaternion-based technique known as quaternion-based signal analysis (QSA) to represent EEG signals obtained using a brain-computer interface (BCI) device to detect and interpret cognitive activity. This quaternion-based signal analysis technique can extract features to represent brain activity related to motor imagery accurately in various mental states. Experimental tests in which users where shown visual graphical cues related to left and right movements were used to collect BCI-recorded signals. These signals were then classified using decision trees (DT), support vector machine (SVM) and k-nearest neighbor (KNN) techniques. The quantitative analysis of the classifiers demonstrates that this technique can be used as an alternative in the EEG-signal modeling phase to identify mental states. PMID:26959029

  9. Three-Class EEG-Based Motor Imagery Classification Using Phase-Space Reconstruction Technique

    Science.gov (United States)

    Djemal, Ridha; Bazyed, Ayad G.; Belwafi, Kais; Gannouni, Sofien; Kaaniche, Walid

    2016-01-01

    Over the last few decades, brain signals have been significantly exploited for brain-computer interface (BCI) applications. In this paper, we study the extraction of features using event-related desynchronization/synchronization techniques to improve the classification accuracy for three-class motor imagery (MI) BCI. The classification approach is based on combining the features of the phase and amplitude of the brain signals using fast Fourier transform (FFT) and autoregressive (AR) modeling of the reconstructed phase space as well as the modification of the BCI parameters (trial length, trial frequency band, classification method). We report interesting results compared with those present in the literature by utilizing sequential forward floating selection (SFFS) and a multi-class linear discriminant analysis (LDA), our findings showed superior classification results, a classification accuracy of 86.06% and 93% for two BCI competition datasets, with respect to results from previous studies. PMID:27563927

  10. Single-trial connectivity estimation for classification of motor imagery data

    Science.gov (United States)

    Billinger, Martin; Brunner, Clemens; Müller-Putz, Gernot R.

    2013-08-01

    Objective. Many brain-computer interfaces (BCIs) use band power (BP) changes in the electroencephalogram to distinguish between different motor imagery (MI) patterns. Most current approaches do not take connectivity of separated brain areas into account. Our objective is to introduce single-trial connectivity features and apply these features to BCI data. Approach. We introduce a procedure for extracting single-trial connectivity estimates from vector autoregressive (VAR) models of independent components in a BCI setting. Main results. In a simulated BCI, we demonstrate that the directed transfer function (DTF) with full-frequency normalization and the direct DTF give classification results similar to BP, while other measures such as the partial directed coherence perform significantly worse. Significance. We show that single-trial MI classification is possible with connectivity measures extracted from VAR models, and that a BCI could potentially utilize such measures.

  11. Programming an offline-analyzer of motor imagery signals via python language.

    Science.gov (United States)

    Alonso-Valerdi, Luz María; Sepulveda, Francisco

    2011-01-01

    Brain Computer Interface (BCI) systems control the user's environment via his/her brain signals. Brain signals related to motor imagery (MI) have become a widespread method employed by the BCI community. Despite the large number of references describing the MI signal treatment, there is not enough information related to the available programming languages that could be suitable to develop a specific-purpose MI-based BCI. The present paper describes the development of an offline-analysis system based on MI-EEG signals via open-source programming languages, and the assessment of the system using electrical activity recorded from three subjects. The analyzer recognized at least 63% of the MI signals corresponding to three classes. The results of the offline analysis showed a promising performance considering that the subjects have never undergone MI trainings.

  12. Common Spatio-Time-Frequency Patterns for Motor Imagery-Based Brain Machine Interfaces

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    Hiroshi Higashi

    2013-01-01

    Full Text Available For efficient decoding of brain activities in analyzing brain function with an application to brain machine interfacing (BMI, we address a problem of how to determine spatial weights (spatial patterns, bandpass filters (frequency patterns, and time windows (time patterns by utilizing electroencephalogram (EEG recordings. To find these parameters, we develop a data-driven criterion that is a natural extension of the so-called common spatial patterns (CSP that are known to be effective features in BMI. We show that the proposed criterion can be optimized by an alternating procedure to achieve fast convergence. Experiments demonstrate that the proposed method can effectively extract discriminative features for a motor imagery-based BMI.

  13. Multisubject Learning for Common Spatial Patterns in Motor-Imagery BCI

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    Dieter Devlaminck

    2011-01-01

    Full Text Available Motor-imagery-based brain-computer interfaces (BCIs commonly use the common spatial pattern filter (CSP as preprocessing step before feature extraction and classification. The CSP method is a supervised algorithm and therefore needs subject-specific training data for calibration, which is very time consuming to collect. In order to reduce the amount of calibration data that is needed for a new subject, one can apply multitask (from now on called multisubject machine learning techniques to the preprocessing phase. Here, the goal of multisubject learning is to learn a spatial filter for a new subject based on its own data and that of other subjects. This paper outlines the details of the multitask CSP algorithm and shows results on two data sets. In certain subjects a clear improvement can be seen, especially when the number of training trials is relatively low.

  14. Quantifying the role of motor imagery in brain-machine interfaces

    Science.gov (United States)

    Marchesotti, Silvia; Bassolino, Michela; Serino, Andrea; Bleuler, Hannes; Blanke, Olaf

    2016-04-01

    Despite technical advances in brain machine interfaces (BMI), for as-yet unknown reasons the ability to control a BMI remains limited to a subset of users. We investigate whether individual differences in BMI control based on motor imagery (MI) are related to differences in MI ability. We assessed whether differences in kinesthetic and visual MI, in the behavioral accuracy of MI, and in electroencephalographic variables, were able to differentiate between high- versus low-aptitude BMI users. High-aptitude BMI users showed higher MI accuracy as captured by subjective and behavioral measurements, pointing to a prominent role of kinesthetic rather than visual imagery. Additionally, for the first time, we applied mental chronometry, a measure quantifying the degree to which imagined and executed movements share a similar temporal profile. We also identified enhanced lateralized μ-band oscillations over sensorimotor cortices during MI in high- versus low-aptitude BMI users. These findings reveal that subjective, behavioral, and EEG measurements of MI are intimately linked to BMI control. We propose that poor BMI control cannot be ascribed only to intrinsic limitations of EEG recordings and that specific questionnaires and mental chronometry can be used as predictors of BMI performance (without the need to record EEG activity).

  15. EEG and behavioural correlates of different forms of motor imagery during action observation in rhythmical actions.

    Science.gov (United States)

    Eaves, D L; Behmer, L P; Vogt, S

    2016-07-01

    Recent studies show that participants can engage in motor imagery (MI) and action observation (AO) simultaneously (AO+MI), indicating a capacity for dual action simulation. Here we studied the electrophysiological correlates and behavioural outcomes of two forms of AO+MI, along with pure MI and pure AO control conditions. In synchronised AO+MI, participants imagined performing a rhythmical action in synchrony with an observed distractor action. In contrast in static AO+MI, where the imagery served to conflict with AO, participants imagined holding a static hand posture during AO. Following synchronised AO+MI, rhythmical execution was strongly biased toward the cycle time of the previously observed rhythm ('imitation bias'), whereas a weaker bias was found following pure MI, and particularly for static AO+MI. In line with these findings, event-related desynchronisation (ERD) in primary sensorimotor and parietal regions was more pronounced in synchronised AO+MI compared to both pure AO and pure MI. These ERD amplitudes were, however, highly similar for static and synchronised AO+MI; suggesting that, regardless of co-represented content, both AO+MI states produced stronger motor activations than single action simulation. In contrast, synchronised AO+MI produced significantly stronger ERD in rostral prefrontal cortex compared to the other three conditions. This specific rostral prefrontal involvement most likely reflected additional cognitive processing for aligning dual action simulations. Together these results provide an important empirical validation of different AO+MI states, in that the imitation bias was strongly modulated by the content of the AO+MI instructions, and that synchronised AO+MI produced stronger behavioural and neurophysiological effects compared to pure AO or MI. PMID:27266395

  16. An Algorithm for Idle-State Detection in Motor-Imagery-Based Brain-Computer Interface

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    Yijun Wang

    2007-07-01

    Full Text Available For a robust brain-computer interface (BCI system based on motor imagery (MI, it should be able to tell when the subject is not concentrating on MI tasks (the “idle state” so that real MI tasks could be extracted accurately. Moreover, because of the diversity of idle state, detecting idle state without training samples is as important as classifying MI tasks. In this paper, we propose an algorithm for solving this problem. A three-class classifier was constructed by combining two two-class classifiers, one specified for idle-state detection and the other for these two MI tasks. Common spatial subspace decomposition (CSSD was used to extract the features of event-related desynchronization (ERD in two motor imagery tasks. Then Fisher discriminant analysis (FDA was employed in the design of two two-class classifiers for completion of detecting each task, respectively. The algorithm successfully provided a way to solve the problem of “idle-state detection without training samples.” The algorithm was applied to the dataset IVc from BCI competition III. A final result with mean square error of 0.30 was obtained on the testing set. This is the winning algorithm in BCI competition III. In addition, the algorithm was also validated by applying to the EEG data of an MI experiment including “idle” task.

  17. Non-invasive detection of high gamma band activity during motor imagery

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    Melissa M Smith

    2014-10-01

    Full Text Available High gamma oscillations (70-150 Hz; HG are rapidly evolving, spatially localized neurophysiological signals that are believed to be the best representative signature of engaged neural populations. The HG band has been best characterized from invasive electrophysiological approaches such as electrocorticography (ECoG because of the increased signal-to-noise ratio that results when by-passing the scalp and skull. Despite the recent observation that HG activity can be detected non-invasively by electroencephalography (EEG, it is unclear to what extent EEG can accurately resolve the spatial distribution of HG signals during active task engagement. We have overcome some of the limitations inherent to acquiring HG signals across the scalp by utilizing individual head anatomy in combination with an inverse modeling method. We applied a linearly constrained minimum variance beamformer (LCMV method on EEG data during a motor imagery paradigm to extract a time-frequency spectrogram at every voxel location on the cortex. To confirm spatially distributed patterns of HG responses, we contrasted overlapping maps of the EEG HG signal with BOLD fMRI data acquired from the same set of neurologically normal subjects during a separate session. We show that scalp-based HG band activity detected by EEG during motor imagery spatially co-localizes with BOLD fMRI data. Taken together, these results suggest that EEG can accurately resolve spatially specific estimates of local cortical high frequency signals, potentially opening an avenue for non-invasive measurement of HG potentials from diverse sets of neurologically impaired populations for diagnostic and therapeutic purposes

  18. Role of the primary motor cortex in the early boost in performance following mental imagery training.

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    Ursula Debarnot

    Full Text Available Recently, it has been suggested that the primary motor cortex (M1 plays a critical role in implementing the fast and transient post-training phase of motor skill consolidation, known to yield an early boost in performance. Whether a comparable early boost in performance occurs following motor imagery (MIM training is still unknown. To address this issue, two groups of subjects learned a finger tapping sequence either by MIM or physical practice (PP. In both groups, performance increased significantly in the post-training phase when compared with the pre-training phase and further increased after a 30 min resting period, indicating that both MIM and PP trainings were equally efficient and induced an early boost in motor performance. This conclusion was corroborated by the results of an additional control group. In a second experiment, we then investigated the causal role of M1 in implementing the early boost process resulting from MIM training. To do so, we inhibited M1 by applying a continuous theta-burst stimulation (cTBS in healthy volunteers just after they learnt, by MIM, the same finger-tapping task as in Experiment #1. As a control, cTBS was applied over the vertex of subjects who underwent the same experiment. We found that cTBS applied over M1 selectively abolished the early boost process subsequent to MIM training. Altogether, the present study provides evidence that MIM practice induces an early boost in performance and demonstrates that M1 is causally involved in this process. These findings further divulge some degree of behavioral and neuronal similitude between MIM and PP.

  19. 2014 Horry County, SC ADS80 4-Band 8 Bit Imagery

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    National Oceanic and Atmospheric Administration, Department of Commerce — All imagery was collected during the 2014 Spring flying season during leaf-off conditions for deciduous vegetation in the State of South Carolina. The sun angle was...

  20. 2013 Rio Puerto Nuevo, Puerto Rico ADS40 4-Band Imagery

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    National Oceanic and Atmospheric Administration, Department of Commerce — Imagery acquired with airborne sensors contain camera and terrain related distortions which make the images unsuitable for geospatial analysis as positions within...

  1. Mental representation and mental practice: experimental investigation on the functional links between motor memory and motor imagery.

    Science.gov (United States)

    Frank, Cornelia; Land, William M; Popp, Carmen; Schack, Thomas

    2014-01-01

    Recent research on mental representation of complex action has revealed distinct differences in the structure of representational frameworks between experts and novices. More recently, research on the development of mental representation structure has elicited functional changes in novices' representations as a result of practice. However, research investigating if and how mental practice adds to this adaptation process is lacking. In the present study, we examined the influence of mental practice (i.e., motor imagery rehearsal) on both putting performance and the development of one's representation of the golf putt during early skill acquisition. Novice golfers (N = 52) practiced the task of golf putting under one of four different practice conditions: mental, physical, mental-physical combined, and no practice. Participants were tested prior to and after a practice phase, as well as after a three day retention interval. Mental representation structures of the putt were measured, using the structural dimensional analysis of mental representation. This method provides psychometric data on the distances and groupings of basic action concepts in long-term memory. Additionally, putting accuracy and putting consistency were measured using two-dimensional error scores of each putt. Findings revealed significant performance improvements over the course of practice together with functional adaptations in mental representation structure. Interestingly, after three days of practice, the mental representations of participants who incorporated mental practice into their practice regime displayed representation structures that were more similar to a functional structure than did participants who did not incorporate mental practice. The findings of the present study suggest that mental practice promotes the cognitive adaptation process during motor learning, leading to more elaborate representations than physical practice only. PMID:24743576

  2. Motor imagery for severely motor-impaired patients: evidence for brain-computer interfacing as superior control solution.

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    Johannes Höhne

    Full Text Available Brain-Computer Interfaces (BCIs strive to decode brain signals into control commands for severely handicapped people with no means of muscular control. These potential users of noninvasive BCIs display a large range of physical and mental conditions. Prior studies have shown the general applicability of BCI with patients, with the conflict of either using many training sessions or studying only moderately restricted patients. We present a BCI system designed to establish external control for severely motor-impaired patients within a very short time. Within only six experimental sessions, three out of four patients were able to gain significant control over the BCI, which was based on motor imagery or attempted execution. For the most affected patient, we found evidence that the BCI could outperform the best assistive technology (AT of the patient in terms of control accuracy, reaction time and information transfer rate. We credit this success to the applied user-centered design approach and to a highly flexible technical setup. State-of-the art machine learning methods allowed the exploitation and combination of multiple relevant features contained in the EEG, which rapidly enabled the patients to gain substantial BCI control. Thus, we could show the feasibility of a flexible and tailorable BCI application in severely disabled users. This can be considered a significant success for two reasons: Firstly, the results were obtained within a short period of time, matching the tight clinical requirements. Secondly, the participating patients showed, compared to most other studies, very severe communication deficits. They were dependent on everyday use of AT and two patients were in a locked-in state. For the most affected patient a reliable communication was rarely possible with existing AT.

  3. Low cost implementation of a Motor Imagery experiment with BCI system and its use in neurorehabilitation.

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    Munoz, John E; Rios, Luis H; Henao, Oscar A

    2014-01-01

    The application of rehabilitation programs based on videogames with brain-computer interfaces (BCI) allows to provide feedback to the user with the expectation of stimulate the brain plasticity that will restore the motor control. The use of specific mental strategies such as Motor Imagery (MI) in neuroscientific experiments with BCI systems often requires the acquisition of sophisticated interfaces and specialized software for execution, which usually have a high implementation costs. We present a combination of low-cost hardware and open-source software for the implementation of videogame based on virtual reality with MI and its potential use as neurotherapy for stroke patients. Three machine learning algorithms for the BCI signals classification are shown: LDA (Linear Discriminant Analysis) and two Support Vector Machines (SVM) in order to determine which task of MI is being performed by the user in a particular moment of the experiment. All classification algorithms was evaluated in 8 healthy subjects, the average accuracy of the best classifier was 96.7%, which shows that it is possible to carry out serious neuroscientific experiments with MI using low-cost BCI systems and achieve comparable accuracies with more sophisticated and expensive devices. PMID:25570187

  4. A Fully Automated Trial Selection Method for Optimization of Motor Imagery Based Brain-Computer Interface.

    Science.gov (United States)

    Zhou, Bangyan; Wu, Xiaopei; Lv, Zhao; Zhang, Lei; Guo, Xiaojin

    2016-01-01

    Independent component analysis (ICA) as a promising spatial filtering method can separate motor-related independent components (MRICs) from the multichannel electroencephalogram (EEG) signals. However, the unpredictable burst interferences may significantly degrade the performance of ICA-based brain-computer interface (BCI) system. In this study, we proposed a new algorithm frame to address this issue by combining the single-trial-based ICA filter with zero-training classifier. We developed a two-round data selection method to identify automatically the badly corrupted EEG trials in the training set. The "high quality" training trials were utilized to optimize the ICA filter. In addition, we proposed an accuracy-matrix method to locate the artifact data segments within a single trial and investigated which types of artifacts can influence the performance of the ICA-based MIBCIs. Twenty-six EEG datasets of three-class motor imagery were used to validate the proposed methods, and the classification accuracies were compared with that obtained by frequently used common spatial pattern (CSP) spatial filtering algorithm. The experimental results demonstrated that the proposed optimizing strategy could effectively improve the stability, practicality and classification performance of ICA-based MIBCI. The study revealed that rational use of ICA method may be crucial in building a practical ICA-based MIBCI system. PMID:27631789

  5. Virtual reality and motor imagery: promising tools for assessment and therapy in Parkinson's disease.

    Science.gov (United States)

    Mirelman, Anat; Maidan, Inbal; Deutsch, Judith E

    2013-09-15

    Motor imagery (MI) and virtual reality (VR) are two evolving therapeutic approaches that make use of cognitive function to study and enhance movement, in particular, balance and mobility of people with Parkinson's disease (PD). This review examines the literature on the use of VR and MI in the assessment of mobility and as a therapeutic intervention to improve balance and gait in patients with PD. A study was eligible for inclusion if MI or VR were used to assess motor or cognitive function to improve gait, balance, or mobility in patients with PD. Data were extracted on the following categories: participants; study design; intervention (type, duration, and frequency); and outcomes. Intervention studies were evaluated for quality using the Physiotherapy Evidence Database scale. Sixteen studies were identified; 4 articles used MI and 12 used VR for assessment and treatment of gait impairments in PD. The studies included small samples and were diverse in terms of methodology. Quality of the intervention trials varied from fair for VR to good for MI. The benefits of using MI and VR for assessment and treatment were noted. Encouraging findings on the potential benefits of using MI and VR in PD were found, although further good-quality research is still needed. Questions remain on the optimal use, content of interventions, and generalizability of findings across the different stages of the disease. The possible mechanisms underlying MI and VR and recommendations for future research and therapy are also presented.

  6. Online and Offline Performance Gains Following Motor Imagery Practice: A Comprehensive Review of Behavioral and Neuroimaging Studies.

    Science.gov (United States)

    Di Rienzo, Franck; Debarnot, Ursula; Daligault, Sébastien; Saruco, Elodie; Delpuech, Claude; Doyon, Julien; Collet, Christian; Guillot, Aymeric

    2016-01-01

    There is now compelling evidence that motor imagery (MI) promotes motor learning. While MI has been shown to influence the early stages of the learning process, recent data revealed that sleep also contributes to the consolidation of the memory trace. How such "online" and "offline" processes take place and how they interact to impact the neural underpinnings of movements has received little attention. The aim of the present review is twofold: (i) providing an overview of recent applied and fundamental studies investigating the effects of MI practice (MIP) on motor learning; and (ii) detangling applied and fundamental findings in support of a sleep contribution to motor consolidation after MIP. We conclude with an integrative approach of online and offline learning resulting from intense MIP in healthy participants, and underline research avenues in the motor learning/clinical domains. PMID:27445755

  7. Motor imagery during action observation modulates automatic imitation effects in rhythmical actions

    Directory of Open Access Journals (Sweden)

    Daniel Lloyd Eaves

    2014-02-01

    Full Text Available We have previously shown that passively observing a task-irrelevant rhythmical action can bias the cycle time of a subsequently executed rhythmical action. Here we use the same paradigm to investigate the impact of different forms of motor imagery (MI during action observation (AO on this automatic imitation (AI effect. Participants saw a picture of the instructed action followed by a rhythmical distractor movie, wherein cycle time was subtly manipulated across trials. They then executed the instructed rhythmical action. When participants imagined performing the instructed action in synchrony with the distractor action (AO + MI, a strong imitation bias was found that was significantly greater than in our previous study. The bias was pronounced equally for compatible and incompatible trials, wherein observed and imagined actions were different in type (e.g., face washing vs. painting or plane of movement, or both. In contrast, no imitation bias was observed when MI conflicted with AO. In Experiment 2, motor execution synchronised with AO produced a stronger imitation bias compared to AO + MI, showing an advantage in synchronisation for overt execution over MI. Furthermore, the bias was stronger when participants synchronised the instructed action with the distractor movie, compared to when they synchronised the distractor action with the distractor movie. Although we still observed a significant bias in the latter condition, this finding indicates a degree of specificity in AI effects for the identity of the synchronised action. Overall, our data show that MI can substantially modulate the effects of AO on subsequent execution, wherein: (1 combined AO + MI can enhance AI effects relative to passive AO; (2 observed and imagined actions can be flexibly coordinated across different action types and planes; and (3 conflicting AO + MI can abolish AI effects. Therefore, combined AO + MI instructions should be considered in motor training and

  8. EEG classification for motor imagery and resting state in BCI applications using multi-class Adaboost extreme learning machine

    Science.gov (United States)

    Gao, Lin; Cheng, Wei; Zhang, Jinhua; Wang, Jue

    2016-08-01

    Brain-computer interface (BCI) systems provide an alternative communication and control approach for people with limited motor function. Therefore, the feature extraction and classification approach should differentiate the relative unusual state of motion intention from a common resting state. In this paper, we sought a novel approach for multi-class classification in BCI applications. We collected electroencephalographic (EEG) signals registered by electrodes placed over the scalp during left hand motor imagery, right hand motor imagery, and resting state for ten healthy human subjects. We proposed using the Kolmogorov complexity (Kc) for feature extraction and a multi-class Adaboost classifier with extreme learning machine as base classifier for classification, in order to classify the three-class EEG samples. An average classification accuracy of 79.5% was obtained for ten subjects, which greatly outperformed commonly used approaches. Thus, it is concluded that the proposed method could improve the performance for classification of motor imagery tasks for multi-class samples. It could be applied in further studies to generate the control commands to initiate the movement of a robotic exoskeleton or orthosis, which finally facilitates the rehabilitation of disabled people.

  9. Long-lasting cortical reorganization as the result of motor imagery of throwing a ball in a virtual tennis court

    Directory of Open Access Journals (Sweden)

    Ana-Maria eCebolla

    2015-12-01

    Full Text Available In order to characterize the neural signature of a motor imagery (MI task, the present study investigates for the first time the oscillation characteristics including both of the time-frequency measurements, event related spectral perturbation (ERSP and intertrial coherence (ITC underlying the variations in the temporal measurements (ERP directly related to a motor imagery task. We hypothesize that significant variations in both of the time-frequency measurements underlie the specific changes in the ERP directly related to motor imagery. For the motor imagery task, we chose a simple everyday task (throwing a tennis ball, that does not require any particular motor expertise, set within the controlled virtual reality scenario of a tennis court. When compared to the rest condition a consistent, long-lasting negative fronto-central ERP wave was accompanied by significant changes in both time frequency measurements suggesting long-lasting cortical activity reorganization. The ERP wave was characterised by two peaks at about 300 ms (N300 and 1000 ms (N1000. The N300 component was centrally localized on the scalp and was accompanied by significant phase consistency in the delta brain rhythms in the contralateral central scalp areas. The N1000 component spread wider centrally and was accompanied by a significant power decrease (or ERD in low beta brain rhythms localized in fronto-precentral and parieto-occipital scalp areas and also by a significant power increase (or ERS in theta brain rhythms spreading fronto-centrally. During the transition from N300 to N1000, a contralateral alpha (mu as well as post-central and parieto- theta rhythms occurred. The visual representation of movement formed in the minds of participants might underlie a top-down process from the fronto-central areas which is reflected by the amplitude changes observed in the fronto-central ERPs and by the significant phase synchrony in contralateral fronto-central delta and

  10. The effect of leisure activity golf practice on motor imagery: an fMRI study in middle adulthood

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    Ladina eBezzola

    2012-03-01

    Full Text Available Much is known about practice-induced plasticity of the motor system. But it is not clear whether the activity in the motor network induced by mental motor imagery is influenced by actually practicing the imagined motor tasks.In a longitudinal study design with two measurement time-points, functional magnetic resonance imaging (fMRI was used to explore dynamic changes in the brain in response to training of highly complex movements by participants of 40 to 60 years of age. The investigated motor learning task entailed golf training practiced by novices as leisure activity. Additionally, data from an age and sex-matched control group without golf training was collected.Results show increased hemodynamic responses during mental rehearsal of a golf swing in non-primary cortical motor areas, sub-cortical motor areas, and parietal regions of the novice golfers and the control subjects. This result complements previous mental imagery research that shows involvement of motor areas during mental rehearsal of a complex movement, especially in subjects with low skill level. More importantly, changes were only found between the two measurement time-points in the golf novice group with a decrease in hemodynamic responses in non-primary motor areas after the 40 hours of golf practice. Thus, the results indicate that a complex physical leisure activity induces functional neuroplasticity in the seldom studied population of middle-aged adults, and that this effect is evident during mental rehearsal of the practiced task. This finding supports the idea that (a a skill improvement is associated with a modified activation pattern in the associated neuronal network that can be identified during mental rehearsal of the practiced task, and that (b a strict training protocol is not necessary to induce functional neuroplasticity.

  11. Motor imagery, P300 and error-related EEG-based robot arm movement control for rehabilitation purpose.

    Science.gov (United States)

    Bhattacharyya, Saugat; Konar, Amit; Tibarewala, D N

    2014-12-01

    The paper proposes a novel approach toward EEG-driven position control of a robot arm by utilizing motor imagery, P300 and error-related potentials (ErRP) to align the robot arm with desired target position. In the proposed scheme, the users generate motor imagery signals to control the motion of the robot arm. The P300 waveforms are detected when the user intends to stop the motion of the robot on reaching the goal position. The error potentials are employed as feedback response by the user. On detection of error the control system performs the necessary corrections on the robot arm. Here, an AdaBoost-Support Vector Machine (SVM) classifier is used to decode the 4-class motor imagery and an SVM is used to decode the presence of P300 and ErRP waveforms. The average steady-state error, peak overshoot and settling time obtained for our proposed approach is 0.045, 2.8% and 44 s, respectively, and the average rate of reaching the target is 95%. The results obtained for the proposed control scheme make it suitable for designs of prosthetics in rehabilitative applications.

  12. Short-term effects of integrated motor imagery practice on muscle activation and force performance.

    Science.gov (United States)

    Di Rienzo, F; Blache, Y; Kanthack, T F D; Monteil, K; Collet, C; Guillot, A

    2015-10-01

    The effect of motor imagery (MI) practice on isometric force development is well-documented. However, whether practicing MI during rest periods of physical training improves the forthcoming performance remains unexplored. We involved 18 athletes in a counterbalanced design including three physical training sessions scheduled over five consecutive days. Training involved 10 maximal isometric contractions against a force plate, with the elbow at 90°. During two sessions, we integrated MI practice (focusing on either muscle activation or relaxation) during the inter-trial rest periods. We measured muscle performance from force plate and electromyograms of the biceps brachii and anterior deltoideus. We continuously monitored electrodermal activity (EDA) to control sympathetic nervous system activity. MI of muscle activation resulted in higher isometric force as compared to both MI of muscle relaxation and passive recovery (respectively +2.1% and +3.5%). MI practice of muscle relaxation also outperformed the control condition (+1.9%). Increased activation of the biceps brachii was recorded under both MI practice conditions compared to control. Biceps brachii activation was similar between the two MI practice conditions, but electromyography revealed a marginal trend toward greater activation of the anterior deltoideus during MI practice of muscle activation. EDA and self-reports indicated that these effects were independent from physiological arousal and motivation. These results might account for priming effects of MI practice yielding to higher muscle activation and force performance. Present findings may be of interest for applications in sports training and neurologic rehabilitation. PMID:26241339

  13. Haptic, Virtual Interaction and Motor Imagery: Entertainment Tools and Psychophysiological Testing

    Directory of Open Access Journals (Sweden)

    Sara Invitto

    2016-03-01

    Full Text Available In this work, the perception of affordances was analysed in terms of cognitive neuroscience during an interactive experience in a virtual reality environment. In particular, we chose a virtual reality scenario based on the Leap Motion controller: this sensor device captures the movements of the user’s hand and fingers, which are reproduced on a computer screen by the proper software applications. For our experiment, we employed a sample of 10 subjects matched by age and sex and chosen among university students. The subjects took part in motor imagery training and immersive affordance condition (a virtual training with Leap Motion and a haptic training with real objects. After each training sessions the subject performed a recognition task, in order to investigate event-related potential (ERP components. The results revealed significant differences in the attentional components during the Leap Motion training. During Leap Motion session, latencies increased in the occipital lobes, which are entrusted to visual sensory; in contrast, latencies decreased in the frontal lobe, where the brain is mainly activated for attention and action planning.

  14. Haptic, Virtual Interaction and Motor Imagery: Entertainment Tools and Psychophysiological Testing.

    Science.gov (United States)

    Invitto, Sara; Faggiano, Chiara; Sammarco, Silvia; De Luca, Valerio; De Paolis, Lucio T

    2016-01-01

    In this work, the perception of affordances was analysed in terms of cognitive neuroscience during an interactive experience in a virtual reality environment. In particular, we chose a virtual reality scenario based on the Leap Motion controller: this sensor device captures the movements of the user's hand and fingers, which are reproduced on a computer screen by the proper software applications. For our experiment, we employed a sample of 10 subjects matched by age and sex and chosen among university students. The subjects took part in motor imagery training and immersive affordance condition (a virtual training with Leap Motion and a haptic training with real objects). After each training sessions the subject performed a recognition task, in order to investigate event-related potential (ERP) components. The results revealed significant differences in the attentional components during the Leap Motion training. During Leap Motion session, latencies increased in the occipital lobes, which are entrusted to visual sensory; in contrast, latencies decreased in the frontal lobe, where the brain is mainly activated for attention and action planning. PMID:26999151

  15. Multiresolution analysis over graphs for a motor imagery based online BCI game.

    Science.gov (United States)

    Asensio-Cubero, Javier; Gan, John Q; Palaniappan, Ramaswamy

    2016-01-01

    Multiresolution analysis (MRA) over graph representation of EEG data has proved to be a promising method for offline brain-computer interfacing (BCI) data analysis. For the first time we aim to prove the feasibility of the graph lifting transform in an online BCI system. Instead of developing a pointer device or a wheel-chair controller as test bed for human-machine interaction, we have designed and developed an engaging game which can be controlled by means of imaginary limb movements. Some modifications to the existing MRA analysis over graphs for BCI have also been proposed, such as the use of common spatial patterns for feature extraction at the different levels of decomposition, and sequential floating forward search as a best basis selection technique. In the online game experiment we obtained for three classes an average classification rate of 63.0% for fourteen naive subjects. The application of a best basis selection method helps significantly decrease the computing resources needed. The present study allows us to further understand and assess the benefits of the use of tailored wavelet analysis for processing motor imagery data and contributes to the further development of BCI for gaming purposes. PMID:26599827

  16. The comparison between motor imagery and verbal rehearsal on the learning of sequential movements

    Directory of Open Access Journals (Sweden)

    Arnaud eSaimpont

    2013-11-01

    Full Text Available Mental practice refers to the cognitive rehearsal of a physical activity. It is widely used by athletes to enhance their performance and its efficiency to help train motor function in people with physical disabilities is now recognized. Mental practice is generally based on motor imagery (MI i.e. the conscious simulation of a movement without its actual execution. It may also be based on verbal rehearsal (VR i.e. the silent rehearsal of the labels associated with an action. In this study, the effect of MI training or VR on the learning and retention of a foot-sequence task was investigated. Thirty right-footed subjects, aged between 22 and 37 years old (mean: 27.4±4.1 years and randomly assigned to one of three groups, practiced a serial reaction time task involving a sequence of three dorsiflexions and three plantar flexions with the left foot. One group (n=10 mentally practiced the sequence with MI for five weeks, another group (n=10 mentally practiced the sequence with VR of the foot positions for the same duration, and a control group (n=10 did not practice the sequence mentally. The time to perform the practiced sequence as well as an unpracticed sequence was recorded before training, immediately after training and six months after training (retention. The main results showed that the speed improvement after training was significantly greater in the MI group compared to the control group and tended to be greater in the VR group compared to the control group. The improvement in performance did not differ in the MI and VR groups. At retention, however, no difference in response times was found among the three groups, indicating that the effect of mental practice did not last over a long period without training. Interestingly, this pattern of results was similar for the practiced and non-practiced sequence. Overall, these results suggest that both MI training and VR help to improve motor performance and that mental practice may induce non

  17. Supplementary motor area and primary auditory cortex activation in an expert break-dancer during the kinesthetic motor imagery of dance to music.

    Science.gov (United States)

    Olshansky, Michael P; Bar, Rachel J; Fogarty, Mary; DeSouza, Joseph F X

    2015-01-01

    The current study used functional magnetic resonance imaging to examine the neural activity of an expert dancer with 35 years of break-dancing experience during the kinesthetic motor imagery (KMI) of dance accompanied by highly familiar and unfamiliar music. The goal of this study was to examine the effect of musical familiarity on neural activity underlying KMI within a highly experienced dancer. In order to investigate this in both primary sensory and motor planning cortical areas, we examined the effects of music familiarity on the primary auditory cortex [Heschl's gyrus (HG)] and the supplementary motor area (SMA). Our findings reveal reduced HG activity and greater SMA activity during imagined dance to familiar music compared to unfamiliar music. We propose that one's internal representations of dance moves are influenced by auditory stimuli and may be specific to a dance style and the music accompanying it. PMID:25301352

  18. Multi-class motor imagery EEG decoding for brain-computer interfaces

    Directory of Open Access Journals (Sweden)

    Deng eWang

    2012-10-01

    Full Text Available Recent studies show that scalp electroencephalography (EEG as a non-invasive interface has great potential for brain-computer interfaces (BCIs. However, one factor that has limited practical applications for EEG-based BCI so far is the difficulty to decode brain signals in a reliable and efficient way. This paper proposes a new robust processing framework for decoding of multi-class motor imagery (MI that is based on five main processing steps. (i Raw EEG segmentation without the need of visual artifact inspection. (ii Considering that EEG recordings are often contaminated not just by electrooculography (EOG but also other types of artifacts, we propose to first implement an automatic artifact correction method that combines regression analysis with independent component analysis (ICA for recovering the original source signals. (iii The significant difference between frequency components based on event-related (de- synchronization and sample entropy is then used to find non-continuous discriminating rhythms. After spectral filtering using the discriminating rhythms, a channel selection algorithm is used to select only relevant channels. (iv Feature vectors are extracted based on the inter-class diversity and time-varying dynamic characteristics of the signals. (v Finally, a support vector machine (SVM is employed for four-class classification. We tested our proposed algorithm on experimental data that was obtained from dataset 2a of BCI competition IV (2008. The overall four-class kappa values (between 0.41 and 0.80 were comparable to other models but without requiring any artifact-contaminated trial removal. The performance showed that multi-class MI tasks can be reliably discriminated using artifact-contaminated EEG recordings from a few channels. This may be a promising avenue for online robust EEG-based BCI applications.

  19. High theta and low alpha powers may be indicative of BCI-illiteracy in motor imagery.

    Directory of Open Access Journals (Sweden)

    Minkyu Ahn

    Full Text Available In most brain computer interface (BCI systems, some target users have significant difficulty in using BCI systems. Such target users are called 'BCI-illiterate'. This phenomenon has been poorly investigated, and a clear understanding of the BCI-illiteracy mechanism or a solution to this problem has not been reported to date. In this study, we sought to demonstrate the neurophysiological differences between two groups (literate, illiterate with a total of 52 subjects. We investigated recordings under non-task related state (NTS which is collected during subject is relaxed with eyes open. We found that high theta and low alpha waves were noticeable in the BCI-illiterate relative to the BCI-literate people. Furthermore, these high theta and low alpha wave patterns were preserved across different mental states, such as NTS, resting before motor imagery (MI, and MI states, even though the spatial distribution of both BCI-illiterate and BCI-literate groups did not differ. From these findings, an effective strategy for pre-screening subjects for BCI illiteracy has been determined, and a performance factor that reflects potential user performance has been proposed using a simple combination of band powers. Our proposed performance factor gave an r = 0.59 (r(2 = 0.34 in a correlation analysis with BCI performance and yielded as much as r = 0.70 (r(2 = 0.50 when seven outliers were rejected during the evaluation of whole data (N = 61, including BCI competition datasets (N = 9. These findings may be directly applicable to online BCI systems.

  20. Comparison Analysis: Granger Causality and New Causality and Their Applications to Motor Imagery.

    Science.gov (United States)

    Hu, Sanqing; Wang, Hui; Zhang, Jianhai; Kong, Wanzeng; Cao, Yu; Kozma, Robert

    2016-07-01

    In this paper we first point out a fatal drawback that the widely used Granger causality (GC) needs to estimate the autoregressive model, which is equivalent to taking a series of backward recursive operations which are infeasible in many irreversible chemical reaction models. Thus, new causality (NC) proposed by Hu et al. (2011) is theoretically shown to be more sensitive to reveal true causality than GC. We then apply GC and NC to motor imagery (MI) which is an important mental process in cognitive neuroscience and psychology and has received growing attention for a long time. We study causality flow during MI using scalp electroencephalograms from nine subjects in Brain-computer interface competition IV held in 2008. We are interested in three regions: Cz (central area of the cerebral cortex), C3 (left area of the cerebral cortex), and C4 (right area of the cerebral cortex) which are considered to be optimal locations for recognizing MI states in the literature. Our results show that: 1) there is strong directional connectivity from Cz to C3/C4 during left- and right-hand MIs based on GC and NC; 2) during left-hand MI, there is directional connectivity from C4 to C3 based on GC and NC; 3) during right-hand MI, there is strong directional connectivity from C3 to C4 which is much clearly revealed by NC than by GC, i.e., NC largely improves the classification rate; and 4) NC is demonstrated to be much more sensitive to reveal causal influence between different brain regions than GC. PMID:26099149

  1. Dynamic frequency feature selection based approach for classification of motor imageries.

    Science.gov (United States)

    Luo, Jing; Feng, Zuren; Zhang, Jun; Lu, Na

    2016-08-01

    Electroencephalography (EEG) is one of the most popular techniques to record the brain activities such as motor imagery, which is of low signal-to-noise ratio and could lead to high classification error. Therefore, selection of the most discriminative features could be crucial to improve the classification performance. However, the traditional feature selection methods employed in brain-computer interface (BCI) field (e.g. Mutual Information-based Best Individual Feature (MIBIF), Mutual Information-based Rough Set Reduction (MIRSR) and cross-validation) mainly focus on the overall performance on all the trials in the training set, and thus may have very poor performance on some specific samples, which is not acceptable. To address this problem, a novel sequential forward feature selection approach called Dynamic Frequency Feature Selection (DFFS) is proposed in this paper. The DFFS method emphasized the importance of the samples that got misclassified while only pursuing high overall classification performance. In the DFFS based classification scheme, the EEG data was first transformed to frequency domain using Wavelet Packet Decomposition (WPD), which is then employed as the candidate set for further discriminatory feature selection. The features are selected one by one in a boosting manner. After one feature being selected, the importance of the correctly classified samples based on the feature will be decreased, which is equivalent to increasing the importance of the misclassified samples. Therefore, a complement feature to the current features could be selected in the next run. The selected features are then fed to a classifier trained by random forest algorithm. Finally, a time series voting-based method is utilized to improve the classification performance. Comparisons between the DFFS-based approach and state-of-art methods on BCI competition IV data set 2b have been conducted, which have shown the superiority of the proposed algorithm. PMID:27253616

  2. Improving the discrimination of hand motor imagery via virtual reality based visual guidance.

    Science.gov (United States)

    Liang, Shuang; Choi, Kup-Sze; Qin, Jing; Pang, Wai-Man; Wang, Qiong; Heng, Pheng-Ann

    2016-08-01

    While research on the brain-computer interface (BCI) has been active in recent years, how to get high-quality electrical brain signals to accurately recognize human intentions for reliable communication and interaction is still a challenging task. The evidence has shown that visually guided motor imagery (MI) can modulate sensorimotor electroencephalographic (EEG) rhythms in humans, but how to design and implement efficient visual guidance during MI in order to produce better event-related desynchronization (ERD) patterns is still unclear. The aim of this paper is to investigate the effect of using object-oriented movements in a virtual environment as visual guidance on the modulation of sensorimotor EEG rhythms generated by hand MI. To improve the classification accuracy on MI, we further propose an algorithm to automatically extract subject-specific optimal frequency and time bands for the discrimination of ERD patterns produced by left and right hand MI. The experimental results show that the average classification accuracy of object-directed scenarios is much better than that of non-object-directed scenarios (76.87% vs. 69.66%). The result of the t-test measuring the difference between them is statistically significant (p = 0.0207). When compared to algorithms based on fixed frequency and time bands, contralateral dominant ERD patterns can be enhanced by using the subject-specific optimal frequency and the time bands obtained by our proposed algorithm. These findings have the potential to improve the efficacy and robustness of MI-based BCI applications. PMID:27282228

  3. Effects of imagery motor training on torque production of ankle plantar flexor muscles

    NARCIS (Netherlands)

    Zijdewind, Inge; Toering, ST; Bessem, B; van der Laan, O; Diercks, RL

    2003-01-01

    The aim of this study was to investigate in control subjects the effect of imagery training on the torque of plantar-flexor muscles of the ankle. Twenty-nine subjects were allocated to one of three groups that performed either imagery training, low-intensity strength training, or no training (only m

  4. Dizzy people perform no worse at a motor imagery task requiring whole body mental rotation; a case-control comparison

    Directory of Open Access Journals (Sweden)

    Sarah B Wallwork

    2013-06-01

    Full Text Available We wanted to find out whether people who suffer from dizziness take longer than people who do not, to perform a motor imagery task that involves implicit whole body rotation. Our prediction was that people in the ‘dizzy’ group would take longer at a left/right neck rotation judgment task but not a left/right hand judgment task, because actually performing the former, but not the latter, would exacerbate their dizziness. Secondly, we predicted that when dizzy participants responded to neck rotation images, responses would be greatest when images were in the upside-down orientation; an orientation with greatest dizzy-provoking potential. To test this idea, we used a case-control comparison design. One hundred and eighteen participants who suffered from dizziness and 118 age, gender, arm pain and neck pain matched controls took part in the study. Participants undertook two motor imagery tasks; a left/right neck rotation judgment task and a left/right hand judgment task. The tasks were completed using the Recognise program; an on-line reaction time task program. Images of neck rotation were shown in four different orientations; 0°, 90°, 180° and 270°. Participants were asked to respond to each ‘neck’ image identifying it as either ‘right neck rotation’ or a ‘left neck rotation’, or for hands, a right or a left hand. Results showed that participants in the ‘dizzy’ group were slower than controls at both tasks (p= 0.015, but this was not related to task (p= 0.498. Similarly, ‘dizzy’ participants were not proportionally worse at images of different orientations (p= 0.878. Our findings suggest impaired performance in dizzy people, an impairment that may be confined to motor imagery or may extend more generally.

  5. 基于fNIRS的运动执行与运动想象脑激活模式比较%Comparison of motor execution and motor imagery brain activation patterns:A fNIRS Study

    Institute of Scientific and Technical Information of China (English)

    白学军; 张琪涵; 章鹏; 周菘; 刘颖; 宋星; 彭国慧

    2016-01-01

    It is widely believed that activity in the primary motor cortex relates only to motor execution. However, the extent to which similar activity occurs when imagining motor movements remains to be determined and, while some researchers report activity in the primary motor cortex during both motor execution and motor imagery tasks (e.g.Solodkin et al., 2004; Sharma et al., 2008), others report no effects of motor imagery (e.g., Binkofski et al., 2000; Hanakawa et al., 2003; Hétu et al., 2013). It is still unknown whether brain activation patterns of motor execution and motor imagery are similar, and whether both tasks activate the primary motor cortex. In addition, it is also unclear about the effect of imagination intensity on the primary motor cortex (this effect has been well established in motor execution tasks). Accordingly, the present research investigated the relationship between the intensity of real and imagined exercise on cortical activity using functional near-infrared spectroscopy (fNIRS), especially in the primary motor cortex. A preliminary assessment used 10 participants (5 male, 5 female), who did not take part in the main experiment, to establish an appropriate level of exercise intensity. For the main experiment, 30 participants (15 male, 15 female) with high imagination ability were selected using the Motor Imagery Questionnaire (Revised). These participants performed a motor execution task in which they actually lifted dumbbells under two levels of exercise intensity (males, 4 pounds and 8 pounds; females, 2 pounds and 4 pounds) and an imagery version of this task in which they imagined lifting dumbbells of these weights. The fNIRS was used to measure cortical changes in oxygen level during the performance of the two tasks. Finally, on completion of the imagery task, the “motor imagery self-assessment questionnaire” was administered to assess the quality of the participants’ imagination. All participants reported that they could imagine

  6. Autonomously Propelled Motors for Value-Added Product Synthesis and Purification.

    Science.gov (United States)

    Srivastava, Sarvesh K; Schmidt, Oliver G

    2016-06-27

    A proof-of-concept design for autonomous, self-propelling motors towards value-added product synthesis and separation is presented. The hybrid motor design consists of two distinct functional blocks. The first, a sodium borohydride (NaBH4 ) granule, serves both as a reaction prerequisite for the reduction of vanillin and also as a localized solid-state fuel in the reaction mixture. The second capping functional block consisting of a graphene-polymer composite serves as a hydrophobic matrix to attract the reaction product vanillyl alcohol (VA), resulting in facile separation of this edible value-added product. These autonomously propelled motors were fabricated at a length scale down to 400 μm, and once introduced in the reaction environment showed rapid bubble-propulsion followed by high-purity separation of the reaction product (VA) by the virtue of the graphene-polymer cap acting as a mesoporous sponge. The concept has excellent potential towards the synthesis/isolation of industrially important compounds, affinity-based product separation, pollutant remediation (such as heavy metal chelation/adsorption), as well as localized fuel-gradients as an alternative to external fuel dependency. PMID:27123788

  7. Neural and cortical analysis of swallowing and detection of motor imagery of swallow for dysphagia rehabilitation-A review.

    Science.gov (United States)

    Yang, H; Ang, K K; Wang, C; Phua, K S; Guan, C

    2016-01-01

    Swallowing is an essential function in our daily life; nevertheless, stroke or other neurodegenerative diseases can cause the malfunction of swallowing function, ie, dysphagia. The objectives of this review are to understand the neural and cortical basis of swallowing and tongue, and review the latest techniques on the detection of motor imagery of swallow (MI-SW) and motor imagery of tongue movements (MI-TM), so that a practical system can be developed for the rehabilitation of poststroke dysphagia patients. Specifically, we firstly describe the swallowing process and how the swallowing function is assessed clinically. Secondly, we review the techniques that performed the neural and cortical analysis of swallowing and tongue based on different modalities such as functional magnetic resonance imaging, positron emission tomography, near-infrared spectroscopy (NIRS), and magnetoencephalography. Thirdly, we review the techniques that performed detection and analysis of MI-SW and MI-TM for dysphagia stroke rehabilitation based on electroencephalography (EEG) and NIRS. Finally, discussions on the advantages and limitations of the studies are presented; an example system and future research directions for the rehabilitation of stroke dysphagia patients are suggested. PMID:27590970

  8. The effect of leisure activity golf practice on motor imagery: an fMRI study in middle adulthood.

    Science.gov (United States)

    Bezzola, Ladina; Mérillat, Susan; Jäncke, Lutz

    2012-01-01

    Much is known about practice-induced plasticity of the motor system. But it is not clear how a physical training influences the mental rehearsal of the practiced task and its associated hemodynamic responses. In the present longitudinal study with two measurement time-points, we used the method of functional magnetic resonance imaging (fMRI) and a motor imagery task, in order to explore the dynamic neuro-functional changes induced by a highly complex physical training. The 11 golf novices between the age of 40 and 60 years practiced the motor training as leisure activity. Additionally, data from an age and sex-matched control group without golf training was collected. As a main result, we demonstrate that changes between the two measurement time-points were only found in the golf novice group. The golf novices showed a decrease in hemodynamic responses during the mental rehearsal of the golf swing in non-primary motor areas after the 40 h of golf practice. Thus, the results indicate that a complex physical leisure activity induces functional neuroplasticity in the seldom studied population of middle-aged adults, and that this effect is evident during mental rehearsal of the practiced task. This finding supports the idea that (a) a skill improvement is associated with a modified activation pattern in the associated neuronal network that can be identified during mental rehearsal of the practiced task, and that (b) a strict training protocol is not necessary to induce functional neuroplasticity. PMID:22479243

  9. Impaired motor planning and motor imagery in children with unilateral spastic cerebral palsy: challenges for the future of pediatric rehabilitation.

    NARCIS (Netherlands)

    Steenbergen, B.; Jongbloed-Pereboom, M.; Spruijt, S.; Gordon, A.M.

    2013-01-01

    Compromised action performance is one of the most characteristic features of children with unilateral spastic cerebral palsy (USCP). Current rehabilitation efforts predominantly aim to improve the capacity and performance of the affected arm. Recent evidence, however, suggests that compromised motor

  10. Anodal transcranial direct current stimulation enhances the effects of motor imagery training in a finger tapping task.

    Science.gov (United States)

    Saimpont, Arnaud; Mercier, Catherine; Malouin, Francine; Guillot, Aymeric; Collet, Christian; Doyon, Julien; Jackson, Philip L

    2016-01-01

    Motor imagery (MI) training and anodal transcranial direct current stimulation (tDCS) applied over the primary motor cortex can independently improve hand motor function. The main objective of this double-blind, sham-controlled study was to examine whether anodal tDCS over the primary motor cortex could enhance the effects of MI training on the learning of a finger tapping sequence. Thirty-six right-handed young human adults were assigned to one of three groups: (i) who performed MI training combined with anodal tDCS applied over the primary motor cortex; (ii) who performed MI training combined with sham tDCS; and (iii) who received tDCS while reading a book. The MI training consisted of mentally rehearsing an eight-item complex finger sequence for 13 min. Before (Pre-test), immediately after (Post-test 1), and at 90 min after (Post-test 2) MI training, the participants physically repeated the sequence as fast and as accurately as possible. An anova showed that the number of sequences correctly performed significantly increased between Pre-test and Post-test 1 and remained stable at Post-test 2 in the three groups (P < 0.001). Furthermore, the percentage increase in performance between Pre-test and Post-test 1 and Post-test 2 was significantly greater in the group that performed MI training combined with anodal tDCS compared with the other two groups (P < 0.05). As a potential physiological explanation, the synaptic strength within the primary motor cortex could have been reinforced by the association of MI training and tDCS compared with MI training alone and tDCS alone. PMID:26540137

  11. Action Verbs and the Primary Motor Cortex: A Comparative TMS Study of Silent Reading, Frequency Judgments, and Motor Imagery

    Science.gov (United States)

    Tomasino, Barbara; Fink, Gereon R.; Sparing, Roland; Dafotakis, Manuel; Weiss, Peter H.

    2008-01-01

    Single pulse transcranial magnetic stimulation (TMS) was applied to the hand area of the left primary motor cortex or, as a control, to the vertex (STIMULATION: TMS[subscript M1] vs. TMS[subscript vertex]) while right-handed volunteers silently read verbs related to hand actions. We examined three different tasks and time points for stimulation…

  12. Use of video observation and motor imagery on jumping performance in national rhythmic gymnastics athletes.

    Science.gov (United States)

    Battaglia, Claudia; D'Artibale, Emanuele; Fiorilli, Giovanni; Piazza, Marina; Tsopani, Despina; Giombini, Arrigo; Calcagno, Giuseppe; di Cagno, Alessandra

    2014-12-01

    The aim of this study was to evaluate whether a mental training protocol could improve gymnastic jumping performance. Seventy-two rhythmic gymnasts were randomly divided into an experimental and control group. At baseline, experimental group completed the Movement Imagery Questionnaire Revised (MIQ-R) to assess the gymnast ability to generate movement imagery. A repeated measures design was used to compare two different types of training aimed at improving jumping performance: (a) video observation and PETTLEP mental training associated with physical practice, for the experimental group, and (b) physical practice alone for the control group. Before and after six weeks of training, their jumping performance was measured using the Hopping Test (HT), Drop Jump (DJ), and Counter Movement Jump (CMJ). Results revealed differences between jumping parameters F(1,71)=11.957; pprotocol described herein was shown to improve jumping performance, thereby preserving the elite athlete's energy for other tasks. PMID:25457420

  13. Using Fractal and Local Binary Pattern Features for Classification of ECOG Motor Imagery Tasks Obtained from the Right Brain Hemisphere.

    Science.gov (United States)

    Xu, Fangzhou; Zhou, Weidong; Zhen, Yilin; Yuan, Qi; Wu, Qi

    2016-09-01

    The feature extraction and classification of brain signal is very significant in brain-computer interface (BCI). In this study, we describe an algorithm for motor imagery (MI) classification of electrocorticogram (ECoG)-based BCI. The proposed approach employs multi-resolution fractal measures and local binary pattern (LBP) operators to form a combined feature for characterizing an ECoG epoch recording from the right hemisphere of the brain. A classifier is trained by using the gradient boosting in conjunction with ordinary least squares (OLS) method. The fractal intercept, lacunarity and LBP features are extracted to classify imagined movements of either the left small finger or the tongue. Experimental results on dataset I of BCI competition III demonstrate the superior performance of our method. The cross-validation accuracy and accuracy is 90.6% and 95%, respectively. Furthermore, the low computational burden of this method makes it a promising candidate for real-time BCI systems. PMID:27255798

  14. EEG Event-Related Desynchronization of patients with stroke during motor imagery of hand movement

    Science.gov (United States)

    Tabernig, Carolina B.; Carrere, Lucía C.; Lopez, Camila A.; Ballario, Carlos

    2016-04-01

    Brain Computer Interfaces (BCI) can be used for therapeutic purposes to improve voluntary motor control that has been affected post stroke. For this purpose, desynchronization of sensorimotor rhythms of the electroencephalographic signal (EEG) can be used. But it is necessary to study what happens in the affected motor cortex of this people. In this article, we analyse EEG recordings of hemiplegic stroke patients to determine if it is possible to detect desynchronization in the affected motor cortex during the imagination of movements of the affected hand. Six patients were included in the study; four evidenced desynchronization in the affected hemisphere, one of them showed no results and the EEG recordings of the last patient presented high noise level. These results suggest that we could use the desynchronization of sensorimotor rhythms of the EEG signal as a BCI paradigm in a rehabilitation programme.

  15. Feature Selection Strategy for Classification of Single-Trial EEG Elicited by Motor Imagery

    DEFF Research Database (Denmark)

    Prasad, Swati; Tan, Zheng-Hua; Prasad, Ramjee;

    2011-01-01

    Brain-Computer Interface (BCI) provides new means of communication for people with motor disabilities by utilizing electroencephalographic activity. Selection of features from Electroencephalogram (EEG) signals for classification plays a key part in the development of BCI systems. In this paper, we...

  16. Motor imagery evokes increased somatosensory activity in parkinson's disease patients with tremor

    NARCIS (Netherlands)

    Helmich, R.C.G.; Bloem, B.R.; Toni, I.

    2012-01-01

    Parkinson's disease (PD) is surprisingly heterogeneous: some patients have a prominent resting tremor, while others never develop this symptom. Here we investigate whether the functional organization of the voluntary motor system differs between PD patients with and without resting tremor, and wheth

  17. Motor imagery evokes increased somatosensory activity in parkinson's disease patients with tremor.

    NARCIS (Netherlands)

    Helmich, R.C.G.; Bloem, B.R.; Toni, I.

    2012-01-01

    Parkinson's disease (PD) is surprisingly heterogeneous: some patients have a prominent resting tremor, while others never develop this symptom. Here we investigate whether the functional organization of the voluntary motor system differs between PD patients with and without resting tremor, and wheth

  18. Comparison of EEG-features and classification methods for motor imagery in patients with disorders of consciousness.

    Directory of Open Access Journals (Sweden)

    Yvonne Höller

    Full Text Available Current research aims at identifying voluntary brain activation in patients who are behaviorally diagnosed as being unconscious, but are able to perform commands by modulating their brain activity patterns. This involves machine learning techniques and feature extraction methods such as applied in brain computer interfaces. In this study, we try to answer the question if features/classification methods which show advantages in healthy participants are also accurate when applied to data of patients with disorders of consciousness. A sample of healthy participants (N = 22, patients in a minimally conscious state (MCS; N = 5, and with unresponsive wakefulness syndrome (UWS; N = 9 was examined with a motor imagery task which involved imagery of moving both hands and an instruction to hold both hands firm. We extracted a set of 20 features from the electroencephalogram and used linear discriminant analysis, k-nearest neighbor classification, and support vector machines (SVM as classification methods. In healthy participants, the best classification accuracies were seen with coherences (mean = .79; range = .53-.94 and power spectra (mean = .69; range = .40-.85. The coherence patterns in healthy participants did not match the expectation of central modulated [Formula: see text]-rhythm. Instead, coherence involved mainly frontal regions. In healthy participants, the best classification tool was SVM. Five patients had at least one feature-classifier outcome with p[Formula: see text]0.05 (none of which were coherence or power spectra, though none remained significant after false-discovery rate correction for multiple comparisons. The present work suggests the use of coherences in patients with disorders of consciousness because they show high reliability among healthy subjects and patient groups. However, feature extraction and classification is a challenging task in unresponsive patients because there is no ground truth to validate the results.

  19. Comparison of EEG-features and classification methods for motor imagery in patients with disorders of consciousness.

    Science.gov (United States)

    Höller, Yvonne; Bergmann, Jürgen; Thomschewski, Aljoscha; Kronbichler, Martin; Höller, Peter; Crone, Julia S; Schmid, Elisabeth V; Butz, Kevin; Nardone, Raffaele; Trinka, Eugen

    2013-01-01

    Current research aims at identifying voluntary brain activation in patients who are behaviorally diagnosed as being unconscious, but are able to perform commands by modulating their brain activity patterns. This involves machine learning techniques and feature extraction methods such as applied in brain computer interfaces. In this study, we try to answer the question if features/classification methods which show advantages in healthy participants are also accurate when applied to data of patients with disorders of consciousness. A sample of healthy participants (N = 22), patients in a minimally conscious state (MCS; N = 5), and with unresponsive wakefulness syndrome (UWS; N = 9) was examined with a motor imagery task which involved imagery of moving both hands and an instruction to hold both hands firm. We extracted a set of 20 features from the electroencephalogram and used linear discriminant analysis, k-nearest neighbor classification, and support vector machines (SVM) as classification methods. In healthy participants, the best classification accuracies were seen with coherences (mean = .79; range = .53-.94) and power spectra (mean = .69; range = .40-.85). The coherence patterns in healthy participants did not match the expectation of central modulated [Formula: see text]-rhythm. Instead, coherence involved mainly frontal regions. In healthy participants, the best classification tool was SVM. Five patients had at least one feature-classifier outcome with p[Formula: see text]0.05 (none of which were coherence or power spectra), though none remained significant after false-discovery rate correction for multiple comparisons. The present work suggests the use of coherences in patients with disorders of consciousness because they show high reliability among healthy subjects and patient groups. However, feature extraction and classification is a challenging task in unresponsive patients because there is no ground truth to validate the results. PMID:24282545

  20. Modulation of hand motor-related area during motor imagery and motor execution before and after middle 2/5 of the MS6 line scalp acupuncture stimulation: An fMRI study.

    Science.gov (United States)

    Romeo, Zanardi; Marta, Maieron; Barbara, Tomasino

    2016-03-01

    Scalp acupuncture (SA) combines the concept of cerebral cortex organization with the principles of acupuncture. The SA stimulates sections of the cerebral cortex. We studied the functional modulation of the left hand sensorimotor area induced by SA in order to investigate the specificity of the SA-related functional effects of the middle 2/5 of the MS6 line of the left side, which corresponds to the upper limb motor segment of the primary motor area. To this purpose, we compared the pre- and post-SA functional activation patterns during an implicit motor imagery task (handedness decision in which participants simulated rotational hand movements) and an explicit manual motor execution task. Feet and mouth movements, and the fMRI changes in their respective representations were used as control conditions. Only SA on the hand area of the left side (as compared to the mouth and the foot representations which were used as control conditions) exerted a release effect on the right hand area. In addition, an increased activation of the superior parietal lobe was seen, which is involved in movement control and planning. Taken together, these preliminary findings may shed light on the SA effects and confirm a prolonged effect of SA even after cessation of needling stimulation. PMID:26799679

  1. Age-specific activation of cerebral areas in motor imagery - a fMRI study

    International Nuclear Information System (INIS)

    The objectives of this study were to study the age-specific activation patterns of cerebral areas during motor execution (ME) and motor imaging (MI) of the upper extremities and to discuss the age-related neural mechanisms associated with ME or MI. The functional magnetic resonance imaging technique was used to monitor the pattern and intensity of brain activation during the ME and MI of the upper extremities in 20 elderly (>50 years) and 19 young healthy subjects (<25 years). No major differences were identified regarding the activated brain areas during ME or MI between the two groups; however, a minor difference was noted. The intensity of the activated brain area during ME was stronger in the older group than in the younger group, while the results with MI were the opposite. The posterior central gyrus and supplementary motor area during MI were more active in the younger group than in the older group. The putamen, lingual, and so on demonstrated stronger activation during dominant hand MI in the older group. The results of this study revealed that the brain structure was altered and that neuronal activity was attenuated with age, and the cerebral cortex and subcortical tissues were found to be over-activated to achieve the same level of ME and MI, indicating that the activating effects of the left hemisphere enhanced with age, whereas the inhibitory effects declined during ME, and activation of the right hemisphere became more difficult during MI. (orig.)

  2. Age-specific activation of cerebral areas in motor imagery - a fMRI study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Li [Chongqing University, Key Laboratory of Biorheological Science and Technology of Ministry of Education, Bioengineering College, Chongqing (China); Third Military Medical University, Department of Medical Image, College of Biomedical Engineering, Chongqing (China); Qiu, Mingguo; Zhang, Jingna; Zhang, Ye; Sang, Linqiong [Third Military Medical University, Department of Medical Image, College of Biomedical Engineering, Chongqing (China); Liu, Chen; Yang, Jun [Third Military Medical University, Department of Radiology, Southwest Hospital, Chongqing (China); Yan, Rubing [Third Military Medical University, Department of Rehabilitation, Southwest Hospital, Chongqing (China); Zheng, Xiaolin [Chongqing University, Key Laboratory of Biorheological Science and Technology of Ministry of Education, Bioengineering College, Chongqing (China)

    2014-04-15

    The objectives of this study were to study the age-specific activation patterns of cerebral areas during motor execution (ME) and motor imaging (MI) of the upper extremities and to discuss the age-related neural mechanisms associated with ME or MI. The functional magnetic resonance imaging technique was used to monitor the pattern and intensity of brain activation during the ME and MI of the upper extremities in 20 elderly (>50 years) and 19 young healthy subjects (<25 years). No major differences were identified regarding the activated brain areas during ME or MI between the two groups; however, a minor difference was noted. The intensity of the activated brain area during ME was stronger in the older group than in the younger group, while the results with MI were the opposite. The posterior central gyrus and supplementary motor area during MI were more active in the younger group than in the older group. The putamen, lingual, and so on demonstrated stronger activation during dominant hand MI in the older group. The results of this study revealed that the brain structure was altered and that neuronal activity was attenuated with age, and the cerebral cortex and subcortical tissues were found to be over-activated to achieve the same level of ME and MI, indicating that the activating effects of the left hemisphere enhanced with age, whereas the inhibitory effects declined during ME, and activation of the right hemisphere became more difficult during MI. (orig.)

  3. A novel Morse code-inspired method for multiclass motor imagery brain-computer interface (BCI) design.

    Science.gov (United States)

    Jiang, Jun; Zhou, Zongtan; Yin, Erwei; Yu, Yang; Liu, Yadong; Hu, Dewen

    2015-11-01

    Motor imagery (MI)-based brain-computer interfaces (BCIs) allow disabled individuals to control external devices voluntarily, helping us to restore lost motor functions. However, the number of control commands available in MI-based BCIs remains limited, limiting the usability of BCI systems in control applications involving multiple degrees of freedom (DOF), such as control of a robot arm. To address this problem, we developed a novel Morse code-inspired method for MI-based BCI design to increase the number of output commands. Using this method, brain activities are modulated by sequences of MI (sMI) tasks, which are constructed by alternately imagining movements of the left or right hand or no motion. The codes of the sMI task was detected from EEG signals and mapped to special commands. According to permutation theory, an sMI task with N-length allows 2 × (2(N)-1) possible commands with the left and right MI tasks under self-paced conditions. To verify its feasibility, the new method was used to construct a six-class BCI system to control the arm of a humanoid robot. Four subjects participated in our experiment and the averaged accuracy of the six-class sMI tasks was 89.4%. The Cohen's kappa coefficient and the throughput of our BCI paradigm are 0.88 ± 0.060 and 23.5bits per minute (bpm), respectively. Furthermore, all of the subjects could operate an actual three-joint robot arm to grasp an object in around 49.1s using our approach. These promising results suggest that the Morse code-inspired method could be used in the design of BCIs for multi-DOF control. PMID:26340647

  4. A novel Morse code-inspired method for multiclass motor imagery brain-computer interface (BCI) design.

    Science.gov (United States)

    Jiang, Jun; Zhou, Zongtan; Yin, Erwei; Yu, Yang; Liu, Yadong; Hu, Dewen

    2015-11-01

    Motor imagery (MI)-based brain-computer interfaces (BCIs) allow disabled individuals to control external devices voluntarily, helping us to restore lost motor functions. However, the number of control commands available in MI-based BCIs remains limited, limiting the usability of BCI systems in control applications involving multiple degrees of freedom (DOF), such as control of a robot arm. To address this problem, we developed a novel Morse code-inspired method for MI-based BCI design to increase the number of output commands. Using this method, brain activities are modulated by sequences of MI (sMI) tasks, which are constructed by alternately imagining movements of the left or right hand or no motion. The codes of the sMI task was detected from EEG signals and mapped to special commands. According to permutation theory, an sMI task with N-length allows 2 × (2(N)-1) possible commands with the left and right MI tasks under self-paced conditions. To verify its feasibility, the new method was used to construct a six-class BCI system to control the arm of a humanoid robot. Four subjects participated in our experiment and the averaged accuracy of the six-class sMI tasks was 89.4%. The Cohen's kappa coefficient and the throughput of our BCI paradigm are 0.88 ± 0.060 and 23.5bits per minute (bpm), respectively. Furthermore, all of the subjects could operate an actual three-joint robot arm to grasp an object in around 49.1s using our approach. These promising results suggest that the Morse code-inspired method could be used in the design of BCIs for multi-DOF control.

  5. A semi-supervised support vector machine approach for parameter setting in motor imagery-based brain computer interfaces

    Science.gov (United States)

    Long, Jinyi; Yu, Zhuliang

    2010-01-01

    Parameter setting plays an important role for improving the performance of a brain computer interface (BCI). Currently, parameters (e.g. channels and frequency band) are often manually selected. It is time-consuming and not easy to obtain an optimal combination of parameters for a BCI. In this paper, motor imagery-based BCIs are considered, in which channels and frequency band are key parameters. First, a semi-supervised support vector machine algorithm is proposed for automatically selecting a set of channels with given frequency band. Next, this algorithm is extended for joint channel-frequency selection. In this approach, both training data with labels and test data without labels are used for training a classifier. Hence it can be used in small training data case. Finally, our algorithms are applied to a BCI competition data set. Our data analysis results show that these algorithms are effective for selection of frequency band and channels when the training data set is small. PMID:21886673

  6. Moving without moving: immediate management following lumbar spine surgery using a graded motor imagery approach: a case report.

    Science.gov (United States)

    Louw, Adriaan; Schmidt, Stephen G; Louw, Colleen; Puentedura, Emilio J

    2015-01-01

    Representational body maps are dynamically maintained in the brain and negatively influenced by neglect, decreased movement and pain. Graded motor imagery (GMI) utilizing various tactile and cognitive processes has shown efficacy in decreasing pain, disability and movement restrictions in musculoskeletal pain. Limited information is known about the cortical changes patients undergo during lumbar surgery (LS), let alone the therapeutic effect of GMI for LS. A 56-year-old patient underwent LS for low back pain, leg pain and progressive neurological deficit. Twenty-four hours prior to and 48 h after LS various psychometric, physical movement and tactile acuity measurements were recorded. Apart from predictable postoperative increases in pain, fear-avoidance, disability and movement-restrictions, pressure pain thresholds (PPT), two-point discrimination (TPD) and tactile acuity was greatly reduced. The patient underwent six physiotherapy (PT) treatments receiving a GMI program aimed at restoring the PPT, TPD and tactile acuity. The results revealed that GMI techniques applied to a patient immediately after LS caused marked improvements in movement (flexion average improvement/session 3.3 cm; straight leg raise average 8.3°/session) and an immediate hypoalgesic effect. GMI may provide PT with a non-threatening therapeutic treatment for the acute LS patient and establish a new role for PT in acute LS patients. PMID:26395828

  7. Classification of Two Class Motor Imagery Tasks Using Hybrid GA-PSO Based K-Means Clustering

    Directory of Open Access Journals (Sweden)

    Suraj

    2015-01-01

    Full Text Available Transferring the brain computer interface (BCI from laboratory condition to meet the real world application needs BCI to be applied asynchronously without any time constraint. High level of dynamism in the electroencephalogram (EEG signal reasons us to look toward evolutionary algorithm (EA. Motivated by these two facts, in this work a hybrid GA-PSO based K-means clustering technique has been used to distinguish two class motor imagery (MI tasks. The proposed hybrid GA-PSO based K-means clustering is found to outperform genetic algorithm (GA and particle swarm optimization (PSO based K-means clustering techniques in terms of both accuracy and execution time. The lesser execution time of hybrid GA-PSO technique makes it suitable for real time BCI application. Time frequency representation (TFR techniques have been used to extract the feature of the signal under investigation. TFRs based features are extracted and relying on the concept of event related synchronization (ERD and desynchronization (ERD feature vector is formed.

  8. Single-trial classification of motor imagery differing in task complexity: a functional near-infrared spectroscopy study

    Directory of Open Access Journals (Sweden)

    Wolf Martin

    2011-06-01

    Full Text Available Abstract Background For brain computer interfaces (BCIs, which may be valuable in neurorehabilitation, brain signals derived from mental activation can be monitored by non-invasive methods, such as functional near-infrared spectroscopy (fNIRS. Single-trial classification is important for this purpose and this was the aim of the presented study. In particular, we aimed to investigate a combined approach: 1 offline single-trial classification of brain signals derived from a novel wireless fNIRS instrument; 2 to use motor imagery (MI as mental task thereby discriminating between MI signals in response to different tasks complexities, i.e. simple and complex MI tasks. Methods 12 subjects were asked to imagine either a simple finger-tapping task using their right thumb or a complex sequential finger-tapping task using all fingers of their right hand. fNIRS was recorded over secondary motor areas of the contralateral hemisphere. Using Fisher's linear discriminant analysis (FLDA and cross validation, we selected for each subject a best-performing feature combination consisting of 1 one out of three channel, 2 an analysis time interval ranging from 5-15 s after stimulation onset and 3 up to four Δ[O2Hb] signal features (Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis. Results The results of our single-trial classification showed that using the simple combination set of channels, time intervals and up to four Δ[O2Hb] signal features comprising Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis, it was possible to discriminate single-trials of MI tasks differing in complexity, i.e. simple versus complex tasks (inter-task paired t-test p ≤ 0.001, over secondary motor areas with an average classification accuracy of 81%. Conclusions Although the classification accuracies look promising they are nevertheless subject of considerable subject-to-subject variability. In the discussion we address each of these aspects, their

  9. Adding effect of current displacement and magnetic circuit saturation in an asynchronous motor mathematical model

    Directory of Open Access Journals (Sweden)

    I.A. Tsodik

    2014-04-01

    Full Text Available A methodology of an asynchronous motor mathematical model synthesis is described. Experiments are suggested to be conducted in the following sequence. Geometrical models are first built in AutoCAD, then imported to Comsol Multiphysics, and further processed in Matlab with computation of coefficients and dependences applied in the asynchronous motor mathematical model.

  10. Long-Lasting Cortical Reorganization as the Result of Motor Imagery of Throwing a Ball in a Virtual Tennis Court

    Science.gov (United States)

    Cebolla, Ana M.; Petieau, Mathieu; Cevallos, Carlos; Leroy, Axelle; Dan, Bernard; Cheron, Guy

    2015-01-01

    In order to characterize the neural signature of a motor imagery (MI) task, the present study investigates for the first time the oscillation characteristics including both of the time-frequency measurements, event related spectral perturbation and intertrial coherence (ITC) underlying the variations in the temporal measurements (event related potentials, ERP) directly related to a MI task. We hypothesize that significant variations in both of the time-frequency measurements underlie the specific changes in the ERP directly related to MI. For the MI task, we chose a simple everyday task (throwing a tennis ball), that does not require any particular motor expertise, set within the controlled virtual reality scenario of a tennis court. When compared to the rest condition a consistent, long-lasting negative fronto-central ERP wave was accompanied by significant changes in both time frequency measurements suggesting long-lasting cortical activity reorganization. The ERP wave was characterized by two peaks at about 300 ms (N300) and 1000 ms (N1000). The N300 component was centrally localized on the scalp and was accompanied by significant phase consistency in the delta brain rhythms in the contralateral central scalp areas. The N1000 component spread wider centrally and was accompanied by a significant power decrease (or event related desynchronization) in low beta brain rhythms localized in fronto-precentral and parieto-occipital scalp areas and also by a significant power increase (or event related synchronization) in theta brain rhythms spreading fronto-centrally. During the transition from N300 to N1000, a contralateral alpha (mu) as well as post-central and parieto-theta rhythms occurred. The visual representation of movement formed in the minds of participants might underlie a top-down process from the fronto-central areas which is reflected by the amplitude changes observed in the fronto-central ERPs and by the significant phase synchrony in contralateral fronto

  11. Imagery : correlação entre o motor imagery e as habilidades técnicas no basquetebol, em escalões de cadetes e juniores B.

    OpenAIRE

    Silva, Luís Miguel Correia da

    2015-01-01

    Dissertação apresentada à Escola Superior de Educação do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Atividade Física. A presente investigação tem como principal propósito verificar se existe correlação entre o imagery e as habilidades técnicas do basquetebol, para os gestos técnicos do deslizamento defensivo, drible, passe e lançamento. Pretende também contribuir para a compreensão do conceito de imagery, podendo auxi...

  12. Motor Imagery Experiences and Use: Asking Patients after Stroke Where, When, What, Why, and How They Use Imagery: A Qualitative Investigation

    Directory of Open Access Journals (Sweden)

    Corina Schuster

    2012-01-01

    Full Text Available Background. A framework on where, when, what, why, and how to use imagery from sports psychology was explored whether it can be applied in patients after stroke in their chronic stage. Methods. Eleven patients (ages 31–85, 3 females, 1.3–6.4 years after stroke were interviewed. Semistructured interviews were conducted before and after a two-week MI intervention period with six MI sessions. Information was obtained regarding experiences and knowledge of MI, and the evaluation of an MI practical example. The coding scheme was based on the framework and a hierarchical categorisation. Results. Information regarding domains where, when, what, why, and how to use imagery was addressed. Patients imagined themselves as healthy individuals, did not focus on surroundings during MI practice,and reported to use positive imagery only. After MI training, patients became more flexible regarding their location and position during MI practice. Conclusions. MI became an automatic process, and patients did not need specific concentration and quietness as mentioned in the first interview. Patients recommended daily MI training and began to transfer MI to practice movements that were affected by the stroke. In contrast to sports, patients did not talk about how MI was triggered rather than how MI was designed.

  13. 普拉提运动想象的脑电功率谱分析%Power spectral analysis of EEG during Pilates motor imagery

    Institute of Scientific and Technical Information of China (English)

    孙红敏; 边志杰; 崔冬; 李小俚

    2012-01-01

    Neural plasticity and movement therapy techniques have been widely used in brain rehabilitation of functional disorders, but still lack of scientific basis. Aiming at this problem, the EEG power spectral of Pilates trained college students in resting and motor imagery states ias analysed. Compared with the resting state, the Alpha peak frequency was significantly increased among the whole brain, and the Beta peak frequency is increased among the forehead and fronto-central area in the Pilates motor imagery. The statistical results show that the connection among the brain neural network can be improved, thus the function of specific brain areas can be affected by Pilates motor imagery. A guide has been provided for the promotion of Pilates exercise and the use of the Pilates motor imagery in the disease rehabilitation field in the future.%神经可塑性技术和运动疗法已经在大脑功能障碍疾病的康复中得到了广泛应用,但仍然缺乏科学依据.针对此问题,本文对受过普拉提训练的大学生在静息和运动想象过程中脑电功率谱进行分析.结果发现与静息状态相比,普拉提运动想象会引起整个脑区的Alpha主峰频率显著增加,前额和额中央区的Beta主峰频率显著增加.该研究统计结果表明普拉提运动确实能够改善大脑神经网络之间的连接,进而影响特定脑区的功能,这可能为将来普拉提运动的推广和将普拉提运动想象应用于脑功能疾病康复领域提供了参考依据.

  14. Robot-Assisted Proprioceptive Training with Added Vibro-Tactile Feedback Enhances Somatosensory and Motor Performance

    Science.gov (United States)

    Cuppone, Anna Vera; Squeri, Valentina; Semprini, Marianna; Masia, Lorenzo; Konczak, Jürgen

    2016-01-01

    This study examined the trainability of the proprioceptive sense and explored the relationship between proprioception and motor learning. With vision blocked, human learners had to perform goal-directed wrist movements relying solely on proprioceptive/haptic cues to reach several haptically specified targets. One group received additional somatosensory movement error feedback in form of vibro-tactile cues applied to the skin of the forearm. We used a haptic robotic device for the wrist and implemented a 3-day training regimen that required learners to make spatially precise goal-directed wrist reaching movements without vision. We assessed whether training improved the acuity of the wrist joint position sense. In addition, we checked if sensory learning generalized to the motor domain and improved spatial precision of wrist tracking movements that were not trained. The main findings of the study are: First, proprioceptive acuity of the wrist joint position sense improved after training for the group that received the combined proprioceptive/haptic and vibro-tactile feedback (VTF). Second, training had no impact on the spatial accuracy of the untrained tracking task. However, learners who had received VTF significantly reduced their reliance on haptic guidance feedback when performing the untrained motor task. That is, concurrent VTF was highly salient movement feedback and obviated the need for haptic feedback. Third, VTF can be also provided by the limb not involved in the task. Learners who received VTF to the contralateral limb equally benefitted. In conclusion, somatosensory training can significantly enhance proprioceptive acuity within days when learning is coupled with vibro-tactile sensory cues that provide feedback about movement errors. The observable sensory improvements in proprioception facilitates motor learning and such learning may generalize to the sensorimotor control of the untrained motor tasks. The implications of these findings for

  15. Block aerial triangulation based on two flight levels ADS40 imagery data%利用双高度层ADS40影像进行区域网空中三角测量

    Institute of Scientific and Technical Information of China (English)

    丁启伟; 戴晨光; 刘亚璠; 万欢

    2012-01-01

    Aerial triangulation, which is the crucial part in the photogrammetry process, is a method to calculate the plane coordinates and elevation of the tie points and the exterior orientation parameters of the photo based on some amount control points. With the development of navigating and positioning technique, highly accurate POS system is equipped on the aerial aircraft to record the position and attitude of the camera at the shooting moment, which is used to support the aerial triangulation. In this paper, it used the two flight levels ADS40 imagery data, POS data and some ground control data to perform aerial triangulation based on ORIMA software. And finally the accuracy of the aerial triangulation with two flight levels imagery data was compared with that of the solo flight level imagery data.%空中三角测量是利用航摄像片与被摄目标之间的空间几何位置关系,根据少量的野外控制点,计算节点的平面坐标与高程以及航摄像片的外方位元素的方法,是摄影测量过程中的重要环节.随着导航定位技术的发展,高精度POS装置被广泛安装到航拍飞机上,用于记录航拍时刻相机的位置与姿态,从而进行辅助空中三角测量.本文研究利用双高度层的ADS40航线影像,结合POS数据,利用一定数量的控制点,基于ORIMA软件进行空中三角测量,并对其解算精度与同一区域单高度层航线影像的空三精度进行比较.

  16. Motor Imagery EEG Classification Based on CI-HMM%基于CI-HMM的运动想象脑电信号分类

    Institute of Scientific and Technical Information of China (English)

    孟明; 满海涛; 佘青山

    2013-01-01

    针对隐马尔科夫模型在运动想象脑电信号分类应用中,其独立性假设与脑电信号间相关性的不一致问题,提出一种基于Choquet模糊积分隐马尔科夫模型的脑电信号分类方法。该模型应用模糊积分的单调性取代了概率测度的可加性,放宽了隐马尔科夫模型的独立性假设。利用重叠滑动窗对脑电信号分段,然后对每段数据提取绝对均值、波长和小波包相对能量特征,构成特征序列用于CI-HMM的训练和分类。选取2008年BCI竞赛Datasets 1的两类运动想象数据进行分类实验,结果表明,该方法有效提高了隐马尔科夫模型方法对运动想象脑电信号分类的性能。%In the applications of hidden Markov model( HMM) in motor imagery electroencephalogram( EEG) classi-fication,the independence assumption of HMM is inconsistent with the inherent correlation of EEG signals. In order to resolve the problem,an EEG classification method based on Choquet fuzzy integral HMM( CI-HMM) is proposed. The independence assumption of HMM is relaxed by substituting the monotonicity of fuzzy integrals for the additivity of probability measures. Each signal was segmented using overlapping sliding window. Then from each segment,the absolute mean,wavelength and wavelet packet based relative energy features were extracted to constitute observation sequence for the CI-HMM training and classification. The BCI Competition 2008 Datasets 1 with two classes of motor imagery were selected for classification experiments. The experimental results show that this method can effectively improve the performance of the HMM method used in motor imagery EEG classification.

  17. Performance evaluation of a motor-imagery-based EEG-Brain computer interface using a combined cue with heterogeneous training data in BCI-Naive subjects

    Directory of Open Access Journals (Sweden)

    Lee Youngbum

    2011-10-01

    Full Text Available Abstract Background The subjects in EEG-Brain computer interface (BCI system experience difficulties when attempting to obtain the consistent performance of the actual movement by motor imagery alone. It is necessary to find the optimal conditions and stimuli combinations that affect the performance factors of the EEG-BCI system to guarantee equipment safety and trust through the performance evaluation of using motor imagery characteristics that can be utilized in the EEG-BCI testing environment. Methods The experiment was carried out with 10 experienced subjects and 32 naive subjects on an EEG-BCI system. There were 3 experiments: The experienced homogeneous experiment, the naive homogeneous experiment and the naive heterogeneous experiment. Each experiment was compared in terms of the six audio-visual cue combinations and consisted of 50 trials. The EEG data was classified using the least square linear classifier in case of the naive subjects through the common spatial pattern filter. The accuracy was calculated using the training and test data set. The p-value of the accuracy was obtained through the statistical significance test. Results In the case in which a naive subject was trained by a heterogeneous combined cue and tested by a visual cue, the result was not only the highest accuracy (p Conclusions We propose the use of this measuring methodology of a heterogeneous combined cue for training data and a visual cue for test data by the typical EEG-BCI algorithm on the EEG-BCI system to achieve effectiveness in terms of consistence, stability, cost, time, and resources management without the need for a trial and error process.

  18. Combining Self-Organizing Mapping and Supervised Affinity Propagation Clustering Approach to Investigate Functional Brain Networks Involved in Motor Imagery and Execution with fMRI Measurements

    Directory of Open Access Journals (Sweden)

    Jiang eZhang

    2015-07-01

    Full Text Available AbstractClustering analysis methods have been widely applied to identifying the functional brain networks of a multitask paradigm. However, the previously used clustering analysis techniques are computationally expensive and thus impractical for clinical applications. In this study a novel method, called SOM-SAPC that combines self-organizing mapping (SOM and supervised affinity propagation clustering (SAPC, is proposed and implemented to identify the motor execution (ME and motor imagery (MI networks. In SOM-SAPC, SOM was first performed to process fMRI data and SAPC is further utilized for clustering the patterns of functional networks. As a result, SOM-SAPC is able to significantly reduce the computational cost for brain network analysis. Simulation and clinical tests involving ME and MI were conducted based on SOM-SAPC, and the analysis results indicated that functional brain networks were clearly identified with different response patterns and reduced computational cost. In particular, three activation clusters were clearly revealed, which include parts of the visual, ME and MI functional networks. These findings validated that SOM-SAPC is an effective and robust method to analyze the fMRI data with multitasks.

  19. Windscreen wiper fluid without added screenwash in motor vehicles: a newly identified risk factor for Legionnaires' disease.

    Science.gov (United States)

    Wallensten, Anders; Oliver, Isabel; Ricketts, Katherine; Kafatos, George; Stuart, James M; Joseph, Carol

    2010-09-01

    A source of infection is rarely identified for sporadic cases of Legionnaires' disease. We found that professional drivers are five times more commonly represented among community acquired sporadic cases in England and Wales than expected. We therefore investigated possible risk exposures in relation to driving or spending time in a motor vehicle. A case control study including all surviving community acquired sporadic cases in England and Wales with onset between 12 July 2008 and 9 March 2009 was carried out. Cases were contacted by phone and controls were consecutively recruited by sequential digital dialling matched by area code, sex and age group. Those who consented were sent a questionnaire asking questions on driving habits, potential sources in vehicles and known risk factors. The results were analysed using logistic regression. 75 cases and 67 controls were included in the study. Multivariable analysis identified two exposures linked to vehicle use associated with an increased risk of Legionnaires' disease: Driving through industrial areas (OR 7.2, 95%CI 1.5-33.7) and driving or being a passenger in a vehicle with windscreen wiper fluid not containing added screenwash (OR 47.2, 95%CI 3.7-603.6). Not adding screenwash to windscreen wiper fluid is a previously unidentified risk factor and appears to be strongly associated with community acquired sporadic cases of Legionnaires' disease. We estimated that around 20% of community acquired sporadic cases could be attributed to this exposure. A simple recommendation to use screenwash may mitigate transmission of Legionella bacteria to drivers and passengers. PMID:20532623

  20. Different performances in static and dynamic imagery and real locomotion. An exploratory trial.

    Directory of Open Access Journals (Sweden)

    Augusto eFusco

    2014-10-01

    Full Text Available Motor imagery is a mental representation of an action without its physical execution. Recently, the simultaneous movement of the body has been added to the mental simulation. This refers to dynamic motor imagery (dMI. This study was aimed at analyzing the temporal features for static and dMI in different locomotor conditions (natural walking, NW, light running, LR, lateral walking, LW, backward walking, BW, and whether these performances were more related to all the given conditions or present only in walking. We have been also evaluated the steps performed in the dMI in comparison with the ones performed by real locomotion. Twenty healthy participants (29.3 ± 5.1 y. old were asked to move towards a visualized target located at 10mt. In dMI, no significant temporal differences respect the actual locomotion were found for all the given tasks (NW: p=0.058, LR: p=0.636, BW: p=0.096; LW: p=0,487. Significant temporal differences between static imagery and actual movements were found for LR (p<0.001 and LW (p<0.001, due to an underestimation of time needed to achieve the target in imagined locomotion. Significant differences in terms of number of steps among tasks were found for LW (p<0.001 and BW (p=0.036, whereas neither in NW (p=0.124 nor LR (p=0.391 between dMI and real locomotion.Our results confirmed that motor imagery is a task-dependent process, with walking being temporally closer than other locomotor conditions. Moreover, the time records of dynamic motor imagery are nearer to the ones of actual locomotion respect than the ones of static motor imagery. Keywords: Walking, dynamic motor imagery, human locomotion, chronometry.

  1. Imagery Training on the Influence of Transfer of the Motor Skill to Non - dominant Hand%表象训练对动作技能向非利手迁移的影响

    Institute of Scientific and Technical Information of China (English)

    朱婷婷; 王小亮

    2012-01-01

    研究采用三组被试,一个控制组,两个实验组进行镜画试验。探讨了表象训练对动作技能向非利手迁移的影响,结果表明:正确的表象训练对动作技能向非利手的正迁移起到了显著的促进作用。%There were three groups in the Mirror drawing test, a control group and two experimental groups. In this study, experiment designed to explore the impact of imagery training on motor skills to transfer to the non - dominant hand, the results show that : the right imagery training on motor skills played a significant role in promo- ting positive transfer to the non -dominant hand.

  2. Motor imagery-induced EEG patterns in individuals with spinal cord injury and their impact on brain-computer interface accuracy

    Science.gov (United States)

    Müller-Putz, G. R.; Daly, I.; Kaiser, V.

    2014-06-01

    Objective. Assimilating the diagnosis complete spinal cord injury (SCI) takes time and is not easy, as patients know that there is no ‘cure' at the present time. Brain-computer interfaces (BCIs) can facilitate daily living. However, inter-subject variability demands measurements with potential user groups and an understanding of how they differ to healthy users BCIs are more commonly tested with. Thus, a three-class motor imagery (MI) screening (left hand, right hand, feet) was performed with a group of 10 able-bodied and 16 complete spinal-cord-injured people (paraplegics, tetraplegics) with the objective of determining what differences were present between the user groups and how they would impact upon the ability of these user groups to interact with a BCI. Approach. Electrophysiological differences between patient groups and healthy users are measured in terms of sensorimotor rhythm deflections from baseline during MI, electroencephalogram microstate scalp maps and strengths of inter-channel phase synchronization. Additionally, using a common spatial pattern algorithm and a linear discriminant analysis classifier, the classification accuracy was calculated and compared between groups. Main results. It is seen that both patient groups (tetraplegic and paraplegic) have some significant differences in event-related desynchronization strengths, exhibit significant increases in synchronization and reach significantly lower accuracies (mean (M) = 66.1%) than the group of healthy subjects (M = 85.1%). Significance. The results demonstrate significant differences in electrophysiological correlates of motor control between healthy individuals and those individuals who stand to benefit most from BCI technology (individuals with SCI). They highlight the difficulty in directly translating results from healthy subjects to participants with SCI and the challenges that, therefore, arise in providing BCIs to such individuals.

  3. On the use of convolutional neural networks and augmented CSP features for multi-class motor imagery of EEG signals classification.

    Science.gov (United States)

    Yang, Huijuan; Sakhavi, Siavash; Ang, Kai Keng; Guan, Cuntai

    2015-01-01

    Learning the deep structures and unknown correlations is important for the detection of motor imagery of EEG signals (MI-EEG). This study investigates the use of convolutional neural networks (CNNs) for the classification of multi-class MI-EEG signals. Augmented common spatial pattern (ACSP) features are generated based on pair-wise projection matrices, which covers various frequency ranges. We propose a frequency complementary feature map selection (FCMS) scheme by constraining the dependency among frequency bands. Experiments are conducted on BCI competition IV dataset IIa with 9 subjects. Averaged cross-validation accuracy of 68.45% and 69.27% is achieved for FCMS and all feature maps, respectively, which is significantly higher (4.53% and 5.34%) than random map selection and higher (1.44% and 2.26%) than filter-bank CSP (FBCSP). The results demonstrate that the CNNs are capable of learning discriminant, deep structure features for EEG classification without relying on the handcrafted features. PMID:26736829

  4. Single trial predictors for gating motor-imagery brain-computer interfaces based on sensorimotor rhythm and visual evoked potentials

    Directory of Open Access Journals (Sweden)

    Andrew eGeronimo

    2016-04-01

    Full Text Available For brain-computer interfaces (BCIs that utilize visual cues to direct the user, the neural signals extracted by the computer are representative of ongoing processes, visual evoked responses, and voluntary modulation. We proposed to use three brain signatures for predicting success on a single trial of a BCI task. The first two features, the amplitude and phase of the pre-trial mu amplitude, were chosen as a correlate for cortical excitability. The remaining feature, related to the visually evoked response to the cue, served as a possible measure of fixation and attention to the task. Of these three features, mu rhythm amplitude over the central electrodes at the time of cue presentation and to a lesser extent the single trial visual evoked response were correlated with the success on the subsequent imagery task. Despite the potential for gating trials using these features, an offline gating simulation was limited in its ability to produce an increase in device throughput. This discrepancy highlights a distinction between the identification of predictive features, and the use of this knowledge in an online BCI. Using such a system, we cannot assume that the user will respond similarly when faced with a scenario where feedback is altered by trials that are gated on a regular basis. The results of this study suggest the possibility of using individualized, pre-task neural signatures for personalized and asynchronous (self-paced BCI applications, although these effects need to be quantified in a real-time adaptive scenario in a future study.

  5. Kinesthetic imagery of musical performance.

    Science.gov (United States)

    Lotze, Martin

    2013-01-01

    Musicians use different kinds of imagery. This review focuses on kinesthetic imagery, which has been shown to be an effective complement to actively playing an instrument. However, experience in actual movement performance seems to be a requirement for a recruitment of those brain areas representing movement ideation during imagery. An internal model of movement performance might be more differentiated when training has been more intense or simply performed more often. Therefore, with respect to kinesthetic imagery, these strategies are predominantly found in professional musicians. There are a few possible reasons as to why kinesthetic imagery is used in addition to active training; one example is the need for mental rehearsal of the technically most difficult passages. Another reason for mental practice is that mental rehearsal of the piece helps to improve performance if the instrument is not available for actual training as is the case for professional musicians when they are traveling to various appearances. Overall, mental imagery in musicians is not necessarily specific to motor, somatosensory, auditory, or visual aspects of imagery, but integrates them all. In particular, the audiomotor loop is highly important, since auditory aspects are crucial for guiding motor performance. All these aspects result in a distinctive representation map for the mental imagery of musical performance. This review summarizes behavioral data, and findings from functional brain imaging studies of mental imagery of musical performance. PMID:23781196

  6. LMD算法与运动想象脑电信号的时频分析%LMD algorithm and time-frequency analysis of motor imagery signal

    Institute of Scientific and Technical Information of China (English)

    张晓楠; 刘建平

    2013-01-01

    脑电信号是极其复杂的非平稳信号,为了精确处理运动想象脑电信号,采用LMD(局域均值分解)方法对其进行时频分析。首先给出仿真信号的LMD分解及时频分布,而后对左右手运动想象脑电信号进行LMD时频分析。研究结果表明,LMD具有较强的时频刻画能力,能够精确描述脑电信号的非线性时变特性,是对脑电信号进行时频分析的有效方法。%The electroencephalogram (EEG) signal is a very complex non-stationary signal. Local mean decomposition (LMD) method is adopted to perform the time-frequency analysis in EEG signal processing. LMD and time-frequency distribu-tion of a simulation signal is given. The LMD time-frequency analysis for the motor imagery EEG signal of right and left hands is carried out. The results show that LMD has a strong ability to clearly describe the time-frequency distribution,and can accurately describe the nonlinear and non-stationary characteristics of EEG signal. LMD is an effective method of time-frequency analysis in EEG signal processing.

  7. User Experience May be Producing Greater Heart Rate Variability than Motor Imagery Related Control Tasks during the User-System Adaptation in Brain-Computer Interfaces

    Science.gov (United States)

    Alonso-Valerdi, Luz M.; Gutiérrez-Begovich, David A.; Argüello-García, Janet; Sepulveda, Francisco; Ramírez-Mendoza, Ricardo A.

    2016-01-01

    Brain-computer interface (BCI) is technology that is developing fast, but it remains inaccurate, unreliable and slow due to the difficulty to obtain precise information from the brain. Consequently, the involvement of other biosignals to decode the user control tasks has risen in importance. A traditional way to operate a BCI system is via motor imagery (MI) tasks. As imaginary movements activate similar cortical structures and vegetative mechanisms as a voluntary movement does, heart rate variability (HRV) has been proposed as a parameter to improve the detection of MI related control tasks. However, HR is very susceptible to body needs and environmental demands, and as BCI systems require high levels of attention, perceptual processing and mental workload, it is important to assess the practical effectiveness of HRV. The present study aimed to determine if brain and heart electrical signals (HRV) are modulated by MI activity used to control a BCI system, or if HRV is modulated by the user perceptions and responses that result from the operation of a BCI system (i.e., user experience). For this purpose, a database of 11 participants who were exposed to eight different situations was used. The sensory-cognitive load (intake and rejection tasks) was controlled in those situations. Two electrophysiological signals were utilized: electroencephalography and electrocardiography. From those biosignals, event-related (de-)synchronization maps and event-related HR changes were respectively estimated. The maps and the HR changes were cross-correlated in order to verify if both biosignals were modulated due to MI activity. The results suggest that HR varies according to the experience undergone by the user in a BCI working environment, and not because of the MI activity used to operate the system. PMID:27458384

  8. 基于HHT和改进CSP算法的运动想象BCI系统%Brain-Computer Interface System of Motor Imagery Base on HHT and Improved CSP

    Institute of Scientific and Technical Information of China (English)

    叶竞; 石锐; 何庆华

    2012-01-01

    Human motor imagery tasks evoke kinds of electroencephalogram (EEG) signal. A brain computer interface is a system that can translate the signal of brain for using in communication and control. By comparing mainstream methods of time-frequency analysis, this paper has adopted Hil- bert- Huang Transform (HHT) to obtain the marginal spectrum and time domain amplitude spectrum to make the time-frequency analysis of EEG. To further enhance' noise ratio of the EEG signal, an im- proved CSP algorithm has been applied. Combined with time-domain energy analysis, reduced dimen- sion feature by sliding window is extracted to make a further improvement in feature selection. The re- suits of experiment indicate that the method can extract feature and classify effectively.%为进一步提高脑电信号的信噪比,通过希尔伯特一黄变换对脑电信号进行时频分析,得到对应的边际谱与瞬时幅值谱。采用改进公共空间模式算法处理信号,结合时域二阶矩能量分析方法,提取经滑动窗截取降维后的能量特征,基于提取的特征对脑电信号进行识别。实验结果表明,该方法能够有效地实现特征提取和模式识别。

  9. User Experience May be Producing Greater Heart Rate Variability than Motor Imagery Related Control Tasks during the User-System Adaptation in Brain-Computer Interfaces.

    Science.gov (United States)

    Alonso-Valerdi, Luz M; Gutiérrez-Begovich, David A; Argüello-García, Janet; Sepulveda, Francisco; Ramírez-Mendoza, Ricardo A

    2016-01-01

    Brain-computer interface (BCI) is technology that is developing fast, but it remains inaccurate, unreliable and slow due to the difficulty to obtain precise information from the brain. Consequently, the involvement of other biosignals to decode the user control tasks has risen in importance. A traditional way to operate a BCI system is via motor imagery (MI) tasks. As imaginary movements activate similar cortical structures and vegetative mechanisms as a voluntary movement does, heart rate variability (HRV) has been proposed as a parameter to improve the detection of MI related control tasks. However, HR is very susceptible to body needs and environmental demands, and as BCI systems require high levels of attention, perceptual processing and mental workload, it is important to assess the practical effectiveness of HRV. The present study aimed to determine if brain and heart electrical signals (HRV) are modulated by MI activity used to control a BCI system, or if HRV is modulated by the user perceptions and responses that result from the operation of a BCI system (i.e., user experience). For this purpose, a database of 11 participants who were exposed to eight different situations was used. The sensory-cognitive load (intake and rejection tasks) was controlled in those situations. Two electrophysiological signals were utilized: electroencephalography and electrocardiography. From those biosignals, event-related (de-)synchronization maps and event-related HR changes were respectively estimated. The maps and the HR changes were cross-correlated in order to verify if both biosignals were modulated due to MI activity. The results suggest that HR varies according to the experience undergone by the user in a BCI working environment, and not because of the MI activity used to operate the system.

  10. Motor and mental training in older people: Transfer, interference, and associated functional neural responses.

    Science.gov (United States)

    Boraxbekk, C J; Hagkvist, Filip; Lindner, Philip

    2016-08-01

    Learning new motor skills may become more difficult with advanced age. In the present study, we randomized 56 older individuals, including 30 women (mean age 70.6 years), to 6 weeks of motor training, mental (motor imagery) training, or a combination of motor and mental training of a finger tapping sequence. Performance improvements and post-training functional magnetic resonance imaging (fMRI) were used to investigate performance gains and associated underlying neural processes. Motor-only training and a combination of motor and mental training improved performance in the trained task more than mental-only training. The fMRI data showed that motor training was associated with a representation in the premotor cortex and mental training with a representation in the secondary visual cortex. Combining motor and mental training resulted in both premotor and visual cortex representations. During fMRI scanning, reduced performance was observed in the combined motor and mental training group, possibly indicating interference between the two training methods. We concluded that motor and motor imagery training in older individuals is associated with different functional brain responses. Furthermore, adding mental training to motor training did not result in additional performance gains compared to motor-only training and combining training methods may result in interference between representations, reducing performance. PMID:27450266

  11. Imaginería motora graduada en el síndrome de miembro fantasma con dolor Graded motor imagery in the phantom limb syndrome with pain

    Directory of Open Access Journals (Sweden)

    M. A. Morales-Osorio

    2012-08-01

    Full Text Available Nuevas investigaciones sobre los cambios corticales en pacientes con dolor crónico han llevado a una reevaluación de las patologías que cursan con dolor crónico y sus tratamientos. Este es el caso del síndrome de miembro fantasma con dolor (SMFD, el cual se centraba en los estímulos nociceptivos periféricos, y ahora se replantean como una disfunción a nivel central. Una de las herramientas altamente evidencia y muchas veces desconocida para los terapeutas es la imaginería motora graduada (IMG. Esta técnica intenta normalizar la secuencia de procesamientos centrales para remediar el dolor crónico amparado en la neurociencias y en dos regalos de esta, como son las neuronas espejos y la neuromatriz. Este artículo resume brevemente los componentes básicos de la IMG, su aplicación y sus beneficios, la cual es la base de trabajo de nuestra línea de investigación, diseñado para los pacientes con SMFD, perteneciente a un centro clínico de la ciudad de Cartagena de Indias en Colombia.New investigations on cortical changes in patients with chronic pain have led to a reassessment of the pathologies that occur with chronic pain and its treatment. This is the case of Phantom limb syndrome with pain (PLP, which focused on peripheral nociceptive stimulus, and are now rethinking as a dysfunction at central level. One of the tools often highly evidence and therapists is unknown to the Graded motor imagery (IMG. This technique attempts to normalize the central processing sequence to remedy chronic pain, supported in the neurosciences and the two gifts, such as mirror neurons and the neuromatrix. This article briefly summarizes the basic components of IMG, your application and its benefits, which is the working basis of our research, designed for patients with SMFD belonging to a clinical center in Cartagena de Indias in Colombia.

  12. Applying a brain-computer interface to support motor imagery practice in people with stroke for upper limb recovery: a feasibility study

    Directory of Open Access Journals (Sweden)

    McDonough Suzanne

    2010-12-01

    Full Text Available Abstract Background There is now sufficient evidence that using a rehabilitation protocol involving motor imagery (MI practice in conjunction with physical practice (PP of goal-directed rehabilitation tasks leads to enhanced functional recovery of paralyzed limbs among stroke sufferers. It is however difficult to confirm patient engagement during an MI in the absence of any on-line measure. Fortunately an EEG-based brain-computer interface (BCI can provide an on-line measure of MI activity as a neurofeedback for the BCI user to help him/her focus better on the MI task. However initial performance of novice BCI users may be quite moderate and may cause frustration. This paper reports a pilot study in which a BCI system is used to provide a computer game-based neurofeedback to stroke participants during the MI part of a protocol. Methods The participants included five chronic hemiplegic stroke sufferers. Participants received up to twelve 30-minute MI practice sessions (in conjunction with PP sessions of the same duration on 2 days a week for 6 weeks. The BCI neurofeedback performance was evaluated based on the MI task classification accuracy (CA rate. A set of outcome measures including action research arm test (ARAT and grip strength (GS, was made use of in assessing the upper limb functional recovery. In addition, since stroke sufferers often experience physical tiredness, which may influence the protocol effectiveness, their fatigue and mood levels were assessed regularly. Results Positive improvement in at least one of the outcome measures was observed in all the participants, while improvements approached a minimal clinically important difference (MCID for the ARAT. The on-line CA of MI induced sensorimotor rhythm (SMR modulation patterns in the form of lateralized event-related desynchronization (ERD and event-related synchronization (ERS effects, for novice participants was in a moderate range of 60-75% within the limited 12 training

  13. Effect of Motor Imagery on Unilateral Spatial Neglect in Stroke Patients%运动想象疗法在脑卒中偏侧忽略训练中的应用①

    Institute of Scientific and Technical Information of China (English)

    葛晴霞; 郭根平; 章慧霞

    2013-01-01

    Objective To observe the effect of motor imagery on unilateral spatial neglect (USN) in stroke patients. Methods 40 stroke patients with USN were divided into treatment group (n=20) and control group (n=20). Both groups received routine physical therapy train-ing, while the treatment group received motor imagery in addition. All the patients were assessed with Chinese Behavioral Inattention Test (CBIT), Mini-mental State Examination (MMSE), Fugl-Meyer assessment (FMA) and modified Barthel index (MBI) before and 8 weeks af-ter treatment. Results The scores of CBIT, MMSE, FMA and MBI were better in the treatment group than in the control group (P0.05),治疗8周后治疗组各项指标优于对照组(P<0.05)。结论运动想象疗法结合常规康复可改善脑卒中偏侧忽略问题,提高日常生活活动能力。

  14. 专家与新手运动表象过程中的脑电变化特点研究%Research on EEG Characteristics of Expert and Novice in Motor Imagery

    Institute of Scientific and Technical Information of China (English)

    安燕; 郑樊慧

    2012-01-01

    Motor imagery is a mental training methods widely used in training and competition,and it's an indispensable field in sport psychology as well.From the perspective of psychophysiology,electroencephalography(EEG) was adopted as the main method of this study in order to explore the characteristics of EEG change in motor imagery process of the difference between expert athletes and novice.The results suggested: During the experiment,it was found that there was no difference between the brain neurology activeness of experts and novice under relaxed condition.No advantage was seen in either left or right hemisphere.During the motor imagery,the different position between expert and novice appeared with movement-related areas,significant differences of δ wave frequency were found left frontal pole、left central and left parietal,α wave frequency were shown left central lobe 、parietal lobes and left occipital lobe,In β wave frequency,significant differences appeared in right parietal,the cortical activation was distributed in the left.Compared with relaxed condition,α wave power percentage in visual motor imagery decreased and increased in kinesthesia motor imagery%运动表象是运动员在训练和比赛中广泛使用的一种非常有效的心理训练方法,也是研究者十分关注的重要研究主题。研究采用EEG来对运动表象进行测量,从心理生理学的角度探索专家与新手之间的差别,研究得出:专家与新手之间安静状态下大脑的神经活跃程度相似,并未因训练不同而产生差异。在运动表象过程中大脑左右半球并没有出现大脑侧性优势。运动表象时专家与新手的差异性出现与运动相关的区域,δ波在左额极区(FP1)、左中央区(C3)、左顶区(P3);α波在左中央区(C3)和左顶区(P3)、右顶区(P4)和左枕区(O1);β波在右顶区(P4)存在显著性差异,其皮层激活在左侧区域分布广泛。运动表象过

  15. Kinesthetic imagery of musical performance

    Directory of Open Access Journals (Sweden)

    Martin eLotze

    2013-06-01

    Full Text Available Musicians use different kinds of imagery. This review focuses on kinesthetic imagery, which has been shown to be an effective complement to actively playing an instrument. However, experience in actual movement performance seems to be a requirement for a recruitment of those brain areas representing movement ideation during imagery. An internal model of movement performance might be more differentiated when training has been more intense or simply performed more often. Therefore, with respect to kinesthetic imagery, these strategies are predominantly found in professional musicians. There are a few possible reasons as to why kinesthetic imagery is used in addition to active training; one example is the need for mental rehearsal of the technically most difficult passages. Training difficult passages repeatedly has the potential to induce fatigue in tendons and muscles and can ultimately result in the development of dystonia. Another reason for mental practice is that mental rehearsal of the piece helps to improve performance if the instrument is not available for actual training as is the case for professional musicians when they are travelling to various appearances. Overall, mental imagery in musicians is not necessarily specific to motor, somatosensory, auditory or visual aspects of imagery, but integrates them all. In particular, the audiomotor loop is highly important, since auditory aspects are crucial for guiding motor performance. Furthermore, slight co-movement, for instance of the fingers, usually occurs when imagining musical performance, a situation different to the laboratory condition where movement execution is strictly controlled. All these aspects result in a distinctive representation map for the mental imagery of musical performance. This review summarizes behavioral data, and findings from functional brain imaging studies of mental imagery of musical performance.

  16. 运动想象疗法在40例脑卒中康复中临床观察%The effect of motor imagery therapy in stroke rehabilitation training

    Institute of Scientific and Technical Information of China (English)

    杨帆; 林英; 刘淑玉; 罗秀珍

    2014-01-01

    Objective To investigate the effect of motor imagery therapy in stroke rehabilitation training.Methods 80 cases of stroke patients,were randomly divided into observation group and control group,40 cases in each group,the control group by Depart-ment of internal medicine drugscombined with conventional rehabilitation treatment,the observation group in the control group treatment increased based on motor imagery therapy,the treatment effect was compared between the two groups.Results the two groups of pa-tients after treatment by different methods,the observation group the FMA score increased significantly than that of control group,the difference was statistically significant (P<0.05 ).Conclusion in the Department of internal medicine drug treatment andrehabilitation training base,combined with motor imagery therapy on stroke has the advantages of obvious curative effect,economy,safety,is the treatment is worthy of clinical application.%目的:探讨运动想象疗法在脑卒中康复训练中的应用效果。方法:80例脑卒中患者,按随机数字表分成观察组和对照组,每组40例,对照组采用内科药物联合常规康复训练治疗;观察组在对照组治疗方法基础上增加运动想象疗法,比较两组患者治疗效果。结果:两组患者经不同方法治疗后,观察组FMA评分升高明显大于对照组,差异具有统计学意义(P<0.05)。结论:在内科药物治疗和康复训练基础上,结合运动想象疗法治疗脑卒中具有疗效显著、经济、安全等优点,是临床值得推广应用的治疗方法。

  17. Simulation of parafoil reconnaissance imagery

    Science.gov (United States)

    Kogler, Kent J.; Sutkus, Linas; Troast, Douglas; Kisatsky, Paul; Charles, Alain M.

    1995-08-01

    Reconnaissance from unmanned platforms is currently of interest to DoD and civil sectors concerned with drug trafficking and illegal immigration. Platforms employed vary from motorized aircraft to tethered balloons. One appraoch currently under evaluation deploys a TV camera suspended from a parafoil delivered to the area of interest by a cannon launched projectile. Imagery is then transmitted to a remote monitor for processing and interpretation. This paper presents results of imagery obtained from simulated parafoil flights in which software techniques were developed to process-in image degradation caused by atmospheric obscurants and perturbations in the normal parafoil flight trajectory induced by wind gusts. The approach to capturing continuous motion imagery from captive flight test recordings, the introduction of simulated effects, and the transfer of the processed imagery back to video tape is described.

  18. Selective deficit of praxis imagery in ideomotor apraxia.

    Science.gov (United States)

    Ochipa, C; Rapcsak, S Z; Maher, L M; Rothi, L J; Bowers, D; Heilman, K M

    1997-08-01

    We studied imagery for learned, skilled movements (praxis imagery) in a patient with severe ideomotor apraxia and intact language abilities. This patient, who made predominantly spatial and movement errors when performing transitive movements demonstrating the use of tools (transitive gestures), was also impaired in her ability to answer imagery questions about joint movement or the spatial position of the hands during action. However, visual object imagery was spared. The finding of parallel praxis production and praxis imagery deficits in this patient suggests that the same representations used for gesture production are also activated during imagery of motor acts. Our findings also suggest that certain aspects of motor imagery may be dissociable from general object imagery. PMID:9270580

  19. 基于张量分解的运动想象脑电分类算法%A Algorithm Based on Tensor decomposition for Motor Imagery EEG Classifying

    Institute of Scientific and Technical Information of China (English)

    刘华生; 唐艳; 汤井田

    2012-01-01

    论文结合短时傅里叶变(short time Fourier transform,STFT)和平行因子分解(parallel factor,PARAFAC)模型,对运动想象脑电(EEG)进行分类。首先,通过短时傅里叶变换获得左、右手运动想象脑电的时频分布,然后平行因子分解方法从构建的张量数据中提取时域特征,最后采用贝叶斯分类器对特征进行分类。在短时傅里叶变换中,选择合理的窗函数长度和相邻片段重叠程度很重要,对分类结果有较大的影响,通过调整这两个参数,论文提出的方法获得了较好的分类结果。%this article combines STFT and PARAFAC model to classify motor imagery EEG. Firstly, we get time-frequency distribution of left/right hand motor imagery EEG through STFT algorithm; secondly, temporal features are extracted from the resulted tensors using PARAFAC model; finally, a Bayes classifier is used to classify the features. During STFT analysis, the choice of window length and percent of overlap of adjacent segments is important, which has great influences on the classifying result, through adjusting these two parameters, the algorithm introduced here can perform well.

  20. Effects of kinesthetic versus visual imagery practice on two technical dance movements: a pilot study.

    Science.gov (United States)

    Girón, Elizabeth Coker; McIsaac, Tara; Nilsen, Dawn

    2012-03-01

    Motor imagery is a type of mental practice that involves imagining the body performing a movement in the absence of motor output. Dance training traditionally incorporates mental practice techniques, but quantitative effects of motor imagery on the performance of dance movements are largely unknown. This pilot study compared the effects of two different imagery modalities, external visual imagery and kinesthetic imagery, on pelvis and hip kinematics during two technical dance movements, plié and sauté. Each of three female dance students (mean age = 19.7 years, mean years of training = 10.7) was assigned to use a type of imagery practice: visual imagery, kinesthetic imagery, or no imagery. Effects of motor imagery on peak external hip rotation varied by both modality and task. Kinesthetic imagery increased peak external hip rotation for pliés, while visual imagery increased peak external hip rotation for sautés. Findings suggest that the success of motor imagery in improving performance may be task-specific. Dancers may benefit from matching imagery modality to technical tasks in order to improve alignment and thereby avoid chronic injury. PMID:22390952

  1. Mental imagery in music performance: underlying mechanisms and potential benefits.

    Science.gov (United States)

    Keller, Peter E

    2012-04-01

    This paper examines the role of mental imagery in music performance. Self-reports by musicians, and various other sources of anecdotal evidence, suggest that covert auditory, motor, and/or visual imagery facilitate multiple aspects of music performance. The cognitive and motor mechanisms that underlie such imagery include working memory, action simulation, and internal models. Together these mechanisms support the generation of anticipatory images that enable thorough action planning and movement execution that is characterized by efficiency, temporal precision, and biomechanical economy. In ensemble performance, anticipatory imagery may facilitate interpersonal coordination by enhancing online predictions about others' action timing. Overlap in brain regions subserving auditory imagery and temporal prediction is consistent with this view. It is concluded that individual differences in anticipatory imagery may be a source of variation in expressive performance excellence and the quality of ensemble cohesion. Engaging in effortful musical imagery is therefore justified when artistic perfection is the goal.

  2. EEG changes during sequences of visual and kinesthetic motor imagery Alterações no EEG durante sequencias de imagética motora visual e cinestésica

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Stecklow

    2010-08-01

    Full Text Available The evoked cerebral electric response when sequences of complex motor imagery (MI task are executed several times is still unclear. This work aims at investigating the existence of habituation in the cortical response, more specifically in the alpha band peak of parietal and occipital areas (10-20 international system electroencephalogram, EEG, protocol. The EEG signals were acquired during sequences of MI of volleyball spike movement in kinesthetic and visual modalities and also at control condition. Thirty right-handed male subjects (18 to 40 years were assigned to either an 'athlete' or a 'non-athlete' group, both containing 15 volunteers. Paired Wilcoxon tests (with α=0.05 indicates that sequential MI of complex tasks promotes cortical changes, mainly in the power vicinity of the alpha peak. This finding is more pronounced along the initial trials and also for the athletes during the modality of kinesthetic motor imagery.A resposta elétrica cerebral evocada quando sequencias de imagética motora (MI de tarefas complexas são executadas seguidamente no tempo permanecem desconhecidas. Este trabalho objetivou investigar a existência de habituação da resposta cortical, mais especificamente na banda do pico de alfa de áreas parietais e occipitais (sistema internacional 10-20, eletroencefalograma, protocolo de EEG. Os sinais de EEG foram adquiridos durante sequências de MI do movimento de ataque do voleibol nas modalidades cinestésica e visual, e também em condição de controle. Trinta voluntários adultos (entre 18 e 40 anos, destros, do gênero masculino foram agrupados como 'atletas' ou 'não-atletas', sendo cada grupo composto de 15 voluntários. Testes pareados de Wilcoxon (com α=0.05 indicaram que a MI sequencial de tarefas complexas promoveram alterações nas respostas corticais, mais especificamente na região ao redor do pico de alfa. Este achado foi mais pronunciado ao longo dos trechos iniciais e também nos atletas durante

  3. Motor cortical plasticity induced by motor learning through mental practice.

    Directory of Open Access Journals (Sweden)

    Laura eAvanzino

    2015-04-01

    Full Text Available Several investigations suggest that actual and mental actions trigger similar neural substrates. Motor learning via physical practice results in long-term potentiation (LTP-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. However, whether this neuroplasticity process contributes to improve motor performance through mental practice remains to be determined. Here, we tested skill learning-dependent changes in primary motor cortex (M1 excitability and plasticity by means of transcranial magnetic stimulation in subjects trained to physically execute or mentally perform a sequence of finger opposition movements. Before and after physical practice and motor-imagery practice, M1 excitability was evaluated by measuring the input-output (IO curve of motor evoked potentials. M1 long-term potentiation (LTP and long-term depression (LTD-like plasticity was assessed with paired-associative stimulation (PAS of the median nerve and motor cortex using an interstimulus interval of 25 ms (PAS25 or 10 ms (PAS10, respectively. We found that even if after both practice sessions subjects significantly improved their movement speed, M1 excitability and plasticity were differentially influenced by the two practice sessions. First, we observed an increase in the slope of IO curve after physical but not after motor-imagery practice. Second, there was a reversal of the PAS25 effect from LTP-like plasticity to LTD-like plasticity following physical and motor-imagery practice. Third, LTD-like plasticity (PAS10 protocol increased after physical practice, whilst it was occluded after motor-imagery practice. In conclusion, we demonstrated that motor-imagery practice lead to the development of neuroplasticity, as it affected the PAS25- and PAS10- induced plasticity in M1. These results, expanding the current knowledge on how motor-imagery training shapes M1 plasticity, might have a potential impact in

  4. 运动想象疗法对急性脑梗死患者上肢瘫痪的效果及脑功能MRI的改变%Effects and changes of brain functional MRI of motor imagery therapy on acute cerebral infarction patients with upper limb paralysis

    Institute of Scientific and Technical Information of China (English)

    冉茂胜; 叶建军; 马东兵; 张莉; 胡杰杰; 杨旭君; 乔小民; 姜晓萍

    2013-01-01

    Objective To investigate the effects and changes of brain functional MRI (fMRI) of motor imagery therapy on acute cerebral infarction ( ACI) patients with upper limb paralysis. Methods Seventy cases of ACI patients with hemiplegia were randomly divided into the control group (drug therapy + exercise) and motor imagery therapy group, each group had 35 cases. The treatment of motor imagery therapy group was on the basis of control group, add into motor imagery therapy, 2 times a day, for 30 d. Before and 30 d after treatment, the patients were scored by Fugl-Meyer scale (FMA) and functional independence measure scale (FIM) , the active range of motion ( AROM) of ipsilateral wrist was measured by a protractor, and the brain movement activation range was measured by blood oxygen level dependent fMRI. Results After treatment, the FMA, FIM scores of paralysis upper extremity, the AROM and range of brain activation were significantly higher or bigger than before treatment in the two groups (P<0. 05 -0.01). And these indicators of motor imagery therapy group were significantly higher or bigger than those in the control group (P<0. 05 —0.01). Conclusions Motor imagery therapy can promote the recovery of the upper limb motor function in acute cerebral infarction patients with hemiplegia, and expand the brain movement activation range on fMRI.%目的 研究运动想象疗法对急性脑梗死患者上肢瘫痪的效果及脑功能MRI(fMRI)的改变.方法 70例脑梗死偏瘫患者,随机分为对照组(药物治疗+运动)和运动想象治疗组,每组35例.运动想象治疗组在对照组的治疗基础上,进行运动想象疗法,每天2次,连续30 d.在治疗前和治疗后30 d,给患者进行Fugl-Meyer量表(FMA)、功能独立性评定量表(FIM)评分,用量角器测定患侧手腕主动活动范围(AROM);用血氧水平依赖性fMRI测定脑运动激活区范围.结果 两组患者治疗后瘫痪上肢的FMA、FIM评分、AROM及脑激活区的范围均明

  5. Postura da mão e imagética motora: um estudo sobre reconhecimento de partes do corpo Hand posture and motor imagery: a body-part recognition study

    Directory of Open Access Journals (Sweden)

    AP Lameira

    2008-10-01

    Full Text Available OBJETIVOS: Assim como a imagética motora, o reconhecimento de partes do corpo aciona representações somatosensoriais específicas. Essas representações são ativadas implicitamente para comparar o corpo com o estímulo. No presente estudo, investigou-se a influência da informação proprioceptiva da postura no reconhecimento de partes do corpo (mãos e propõe-se a utilização dessa tarefa na reabilitação de pacientes neurológicos. MATERIAIS E MÉTODOS: Dez voluntários destros participaram do experimento. A tarefa era reconhecer a lateralidade de figuras da mão apresentada, em várias perspectivas e em vários ângulos de orientação. Para a figura da mão direita, o voluntário pressionava a tecla direita e para a figura da mão esquerda, a tecla esquerda. Os voluntários realizavam duas sessões: uma com as mãos na postura prona e outra com as mãos na postura supina. RESULTADOS: Os tempos de reação manual (TRM eram maiores para as vistas e orientações, nas quais é difícil realizar o movimento real, mostrando que durante a tarefa, existe um acionamento de representações motoras para comparar o corpo com o estímulo. Além disso, existe uma influência da postura do sujeito em vistas e ângulos específicos. CONCLUSÕES: Estes resultados mostram que representações motoras são ativadas para comparar o corpo com o estímulo e que a postura da mão influencia esta ressonância entre estímulo e parte do corpo.OBJECTIVE: Recognition of body parts activates specific somatosensory representations in a way that is similar to motor imagery. These representations are implicitly activated to compare the body with the stimulus. In the present study, we investigate the influence of proprioceptive information relating to body posture on the recognition of body parts (hands. It proposes that this task could be used for rehabilitation of neurological patients. METHODS: Ten right-handed volunteers participated in this experiment. The

  6. Motor imagery training can improve motor function and gait after stroke%基于镜像神经元理论的运动想象训练对脑卒中患者运动功能及步态的影响

    Institute of Scientific and Technical Information of China (English)

    李岩; 顾旭东; 时美芳; 李辉; 傅建明; 吴华

    2015-01-01

    Objective To investigate the effect of motor imagery therapy based on mirror neuron theory on the motor function and gait in stroke survivors.Methods Forty-nine stroke survivors were randomly divided into a treatment group (n =24) and a control group (n =25) using a random number table.All the patients in both groups were given similar conventional rehabilitation treatment.In addition,the patients in the treatment group were given motor imagery training based on mirror neuron theory once a day for 20 min each time,5 days a week,lasting 8 weeks.The Fugl-Meyer assessment (FMA),Functional Ambulation Categories (FACs),average step length,the percentage of time spent on the intact foot and the paralyzed foot,and 6 minute walking distance were used to evaluate the subjects' motor function and gait before and after 8 weeks of treatment.Results Before the intervention there was no significant difference between the two groups in terms of any of the measurements.At the end of the 8 weeks of treatment all measurements in both groups had significantly improved compared with before training.The averages of all the measures were significantly better in the treatment group than in the control group.Conclusions Motor imagery training based on mirror neuron theory can improve the motor function and gait of stroke survivors.%目的 观察基于镜像神经元理论的运动想象训练对脑卒中患者运动功能及步态的影响.方法 将脑卒中偏瘫患者49例按随机数字表法分为治疗组24例和对照组25例,2组患者均接受常规神经内科药物治疗和常规康复治疗,治疗组在此基础上增加基于镜像神经元理论的运动想象训练,每日1次,每次20 min,每周训练5d,连续训练8周.治疗前和治疗8周后(治疗后)对2组患者的下肢运动功能(FMA)、步行能力(FAC)、双侧平均步长、健侧和患侧负重时间百分比以及6 min步行距离进行评定.结果 2组患者的FMA、FAC、双侧平均步长、健侧和患

  7. 想象足背屈训练对脑梗死偏瘫患者下肢功能恢复的影响%Efficacy of foot dorsiflexion-centered motor imagery training on lower limb function of poststroke hemiplegic patients

    Institute of Scientific and Technical Information of China (English)

    雷艳; 李平; 陈少玲; 王芳; 陈尚杰; 赖伏虎

    2012-01-01

    目的 探讨想象足背屈训练对脑梗死偏瘫患者下肢运动功能恢复的促进作用.方法 将58例脑梗死下肢偏瘫患者随机分为干预组(30例)和对照组(28例),两组患者均接受常规康复治疗,干预组在此基础上进行连续5周的想象足背屈训练.结果 治疗后干预组患者Brunnstrom分期、FMA和MBI评分显著优于对照组(均P<0.01).结论 想象足背屈训练有效促进患者下肢运动功能的恢复及日常生活活动能力的改善.%Objective To observe the effects of foot dorsiflexion-centered motor imagery training on lower limb function of poststroke hemiplegic patients. Methods Fifty-eight poststroke hemiplegic patients were randomly divided into an intervention group of 30 and a control group of 28. All patients were given routine rehabilitation treatment, while the intervention group additionally received foot dorsiflexion-centered motor imagery training for 5 weeks. Results The Brunnstrom staging, the Fugl-Meyer assessment (FMA) score, and the modified Barthel index (MBI) score in the intervention group were significantly higher than those in the control group (P<0. 01 for all). Conclusion Foot dorsiflexion-centered motor imagery training can boost recovery of lower limb function and improve daily life activity of poststroke hemiplegic patients.

  8. Phenomenology of intrusive imagery in obsessive compulsive disorder (OCD).

    OpenAIRE

    Lipton, M.

    2008-01-01

    The study of intrusive mental imagery in anxiety is a growing area of interest. Whilst there is an appreciation of the variation in thematic content (Hirsch & Holmes, 2007), less is understood about the wider phenomenology and function of intrusive imagery across the anxiety disorders. The aim of the review is to adopt a transdiagnostic perspective, and compare and contrast the literature on intrusive imagery in anxiety in terms of the content, prevalence, frequency and characteristics. In ad...

  9. Adaptive Feature Extraction Based on Best Basis of Wavelet Packet for Motor Imagery EEG%基于小波包最优基的运动想象EEG自适应特征提取方法

    Institute of Scientific and Technical Information of China (English)

    李明爱; 林琳; 杨金福

    2011-01-01

    In brain-computer interfaces of imagery movement, a new method which can adaptively extract features on the basis of the best wavelet package basis is proposed to solve the problems such as the low classification accuracy and weak self-adaptation, etc. First, wavelet packet is exploited to decompose the motor imagery EEG signal ; second, the traditional distance criterion is optimized by introducing a weight parameter which reflects the importance of including both the interclass and the intraclass inertias, and this evaluation criterion for classification is not only under the condition that the criteria is additive for the choice of the best wavelet packet basis, but also can effectively improve the separability of the feature information in frequency subbandst Third, the best wavelet packet basis is attained by using a fast search strategy of "from the bottom to the top, from the left to the right", and the classification feature is extracted by choosing the part wavelet package coefficient which can attain higher value by calculating the classification evaluation criterion according to the best basis; The experimental results which are compared with another common method of time and frequency analysis, show that the algorithm could produce high classification accuracy and less time consumption.%针对运动想象脑机接口系统存在分类正确率低、自适应能力差等不足,提出一种基于小波包最优基的自适应特征提取方法;该方法首先对运动想象EEG进行小波包分解;其次,对传统的距离准则进行改进,通过引入权重因子表征对类内距离和类间距离的关注程度,获得一种既可满足小波包最优基评价准则的可加性条件,又有效地增强了频带特征信息的可分离性的评价准则;进而,采用“自底向顶、自左至右”的快速搜索策略获取小波包最优基,并选取最优基对应的分类性能评价值较高的部分频带小波包系数构成分类特征;

  10. Current Resource Imagery Projects

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — Map showing coverage of current Resource imagery projects. High resolution/large scale Resource imagery is typically acquired for the U.S. Forest Service and other...

  11. NAIP 2015 Imagery Feedback

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The NAIP 2015 Imagery Feedback web application allows users to make comments and observations about the quality of the 2015 National Agriculture Imagery Program...

  12. NAIP 2014 Imagery Feedback

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The NAIP 2014 Imagery Feedback map allows users to make comments and observations about the quality of the 2014 National Agriculture Imagery Program (NAIP)...

  13. Application of digital signal processor in brain-computer interface based on motor imagery potential%DSP在基于想象动作电位的脑-机接口中的应用

    Institute of Scientific and Technical Information of China (English)

    赵丽; 高新

    2012-01-01

    应用数字信号处理器设计了一个基于想象动作电位的脑-机接口系统,通过模拟滤波与数字信号器处理相结合的方法,实现了对想象动作电位信息的有效采集和处理.系统在硬件上设计了脑电信号放大器,DSP开发板;对脑电信号放大、AD转换后,通过分类特征提取处理后,完成动作识别与控制命令的输出.将数字信号处理器应用在脑-机接口中,利用数字信号处理器优异的处理能力和丰富的外设资源,实现了一个嵌入式、微型化的脑-机接口构建,实现了脑-机接口实时处理与微型化.%This paper presents motor-imaginary-potential-based brain-computer interface (BCI) interface by using digital signal processor (DSP). Combining analog filtering and digital processing; realize the motor imaginary potential information acquisition effectively and processing. A EEG amplifier and DSP development board were designed in system for hardware. Motor imaginary potential information through EEG-amplifier and AD converted, after classification and feature extraction,gesture recognition will be completed and control command will be output to control peripherals. In this paper, digital signal processor (DSP) is used in brain-computer interface (BCI), using the DSP achieved a brain-computer interface real-time processing and miniaturization with its excellent processing power and rich resources of the peripheral. A on embedded technology Based, Miniaturization of brain-computer interface was built.

  14. Mental Representation and Motor Imagery Training

    OpenAIRE

    Thomas eSchack; Kai eEssig; Cornelia eFrank; Dirk eKoester

    2014-01-01

    Research in sports, dance and rehabilitation has shown that Basic Action Concepts (BACs) are fundamental building blocks of mental action representations. BACs are based on chunked body postures related to common functions for realizing action goals. In this paper, we outline issues in research methodology and an experimental method, SDA-M (structural dimensional analysis of mental representation), to assess action-relevant representational structures that reflect the organization of BACs. Th...

  15. Mental representation and motor imagery training

    OpenAIRE

    Schack, Thomas; Essig, Kai; Frank, Cornelia; Koester, Dirk

    2014-01-01

    Research in sports, dance and rehabilitation has shown that basic action concepts (BACs) are fundamental building blocks of mental action representations. BACs are based on chunked body postures related to common functions for realizing action goals. In this paper, we outline issues in research methodology and an experimental method, the structural dimensional analysis of mental representation (SDA-M), to assess action-relevant representational structures that reflect the organization of BACs...

  16. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop...... architecture that resides beyond their own imag- inative capabilities. In other words the core aim of the assignment is to equip students with an understand- ing that architecture can be devel- oped through a predetermined ge- neric process and that through this process opportunities exist to devel- op...... something original and genuine that decisively challenges the limits of the field of architecture. This un- derstanding is important if students are to avoid mimicking an existing world of imagery in architecture or fragments of it. The point of departure for the MO- TOR assignment is that a car engine...

  17. Aerial Photography and Imagery, Ortho-Corrected - VOLUSIA 2006 Orthophotography

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — 2006, 6 inch Pixel Color Orthophotography - - Panchromatic, red, green, blue and near infrared imagery was acquired using the Leica ADS40 multi-spectral scanner...

  18. Brain activation profiles during kinesthetic and visual imagery: An fMRI study.

    Science.gov (United States)

    Kilintari, Marina; Narayana, Shalini; Babajani-Feremi, Abbas; Rezaie, Roozbeh; Papanicolaou, Andrew C

    2016-09-01

    The aim of this study was to identify brain regions involved in motor imagery and differentiate two alternative strategies in its implementation: imagining a motor act using kinesthetic or visual imagery. Fourteen adults were precisely instructed and trained on how to imagine themselves or others perform a movement sequence, with the aim of promoting kinesthetic and visual imagery, respectively, in the context of an fMRI experiment using block design. We found that neither modality of motor imagery elicits activation of the primary motor cortex and that each of the two modalities involves activation of the premotor area which is also activated during action execution and action observation conditions, as well as of the supplementary motor area. Interestingly, the visual and the posterior cingulate cortices show reduced BOLD signal during both imagery conditions. Our results indicate that the networks of regions activated in kinesthetic and visual imagery of motor sequences show a substantial, while not complete overlap, and that the two forms of motor imagery lead to a differential suppression of visual areas. PMID:27288703

  19. Planning, preparation, execution, and imagery of volitional action.

    Science.gov (United States)

    Deecke, L

    1996-03-01

    There are different motor sets, which a human subject can be in or act from: he or she can be in a self-initiated voluntary movement set (action) or in a response set (re-action). Also, imagery sets are available that are necessary for the acquisition and practice of skill. Most important are such imagery sets for rehearsal in theatre, dance, music, sports, combat, etc. PMID:8713545

  20. Planning, preparation, execution, and imagery of volitional action

    OpenAIRE

    Deecke, Lüder

    1996-01-01

    There are different motor sets, which a human subject can be in or act from: He or she can be in a self-initiated voluntary movement set (action) or in a response set (re-action). Also, imagery sets are available that are necessary for the acquisition and practice of skill. Most important are such imagery sets for rehearsal in theatre, dance, music, sports, combat, etc.

  1. Effect Observation of Placement of Good Posture and Position in Combination with Motor Imagery Training on ;Stroke Patients in Bed%良姿位摆放结合运动表象训练在脑卒中卧床患者中的效果观察

    Institute of Scientific and Technical Information of China (English)

    凌英; 周楠; 杨微

    2016-01-01

    Objective To explore the effect of good posture and position in combined with motor imagery training on the functional recovery of stroke patients in bed. Methods 88 cases of stroke patients with hemiplegia were randomly divided into ex-perimental group and control group,44 cases each group. The control group was treated with posture nursing of good posture and position,while the experimental group was given motor imagery training on the basis of the control group. We analyzed the marked effective rate of limb function recovery 3 weeks and 6 weeks after intervention and adopted the modified Barthel Index( MBI) and simplified Fugl Meyer motor function scale( FMA) to evaluate,respectively. Results The difference of MBI,FMA and FIM statis-tics of patients before enrollment between two groups showed no statistical significance(P>0. 05). 3 and 6 weeks after interven-tion,marked effective rate of experimental group was obviously higher than that of control group and MBI,FMA as well as FIM scores of experimental group were all significantly higher than those of control group,with a statistically significant difference( P0.05);干预3周和6周后,试验组显效率明显高于对照组,MBI、FMA及FIM评分提高分均显著高于对照组,差异有统计学意义(P<0.05)。结论良姿位摆放结合运动表象训练有助于脑卒中偏瘫卧床患者运动功能的恢复,同时缩短康复时间。

  2. Health-related ad information and health motivation effects on product evaluations

    DEFF Research Database (Denmark)

    Chrysochou, Polymeros; Grunert, Klaus G

    2014-01-01

    in ads. Three types of healthrelated ad elements are distinguished: functional claims, process claims and health imagery. These elements were combined in mock ads and an online experiment was run to test the study hypotheses. Results show that health imagery has the largest impact on consumers' product...

  3. Hairy AdS Solitons

    CERN Document Server

    Anabalon, Andres; Choque, David

    2016-01-01

    We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We discuss the role of these solutions for the existence of first order phase transitions for planar hairy black holes within these theories.

  4. Auditory-motor learning influences auditory memory for music.

    Science.gov (United States)

    Brown, Rachel M; Palmer, Caroline

    2012-05-01

    In two experiments, we investigated how auditory-motor learning influences performers' memory for music. Skilled pianists learned novel melodies in four conditions: auditory only (listening), motor only (performing without sound), strongly coupled auditory-motor (normal performance), and weakly coupled auditory-motor (performing along with auditory recordings). Pianists' recognition of the learned melodies was better following auditory-only or auditory-motor (weakly coupled and strongly coupled) learning than following motor-only learning, and better following strongly coupled auditory-motor learning than following auditory-only learning. Auditory and motor imagery abilities modulated the learning effects: Pianists with high auditory imagery scores had better recognition following motor-only learning, suggesting that auditory imagery compensated for missing auditory feedback at the learning stage. Experiment 2 replicated the findings of Experiment 1 with melodies that contained greater variation in acoustic features. Melodies that were slower and less variable in tempo and intensity were remembered better following weakly coupled auditory-motor learning. These findings suggest that motor learning can aid performers' auditory recognition of music beyond auditory learning alone, and that motor learning is influenced by individual abilities in mental imagery and by variation in acoustic features. PMID:22271265

  5. The addition of functional task-oriented mental practice to conventional physical therapy improves motor skills in daily functions after stroke

    Directory of Open Access Journals (Sweden)

    Clarissa C. Santos-Couto-Paz

    2013-12-01

    Full Text Available BACKGROUND: Mental practice (MP is a cognitive strategy which may improve the acquisition of motor skills and functional performance of athletes and individuals with neurological injuries. OBJECTIVE: To determine whether an individualized, specific functional task-oriented MP, when added to conventional physical therapy (PT, promoted better learning of motor skills in daily functions in individuals with chronic stroke (13±6.5 months post-stroke. METHOD: Nine individuals with stable mild and moderate upper limb impairments participated, by employing an A1-B-A2 single-case design. Phases A1 and A2 included one month of conventional PT, and phase B the addition of MP training to PT. The motor activity log (MAL-Brazil was used to assess the amount of use (AOU and quality of movement (QOM of the paretic upper limb; the revised motor imagery questionnaire (MIQ-RS to assess the abilities in kinesthetic and visual motor imagery; the Minnesota manual dexterity test to assess manual dexterity; and gait speed to assess mobility. RESULTS: After phase A1, no significant changes were observed for any of the outcome measures. However, after phase B, significant improvements were observed for the MAL, AOU and QOM scores (p<0.0001, and MIQ-RS kinesthetic and visual scores (p=0.003; p=0.007, respectively. The significant gains in manual dexterity (p=0.002 and gait speed (p=0.019 were maintained after phase A2. CONCLUSIONS: Specific functional task-oriented MP, when added to conventional PT, led to improvements in motor imagery abilities combined with increases in the AOU and QOM in daily functions, manual dexterity, and gait speed.

  6. Performance improvements from imagery:evidence that internal visual imagery is superior to external visual imagery for slalom performance

    Directory of Open Access Journals (Sweden)

    Nichola eCallow

    2013-10-01

    Full Text Available We report three experiments investigating the hypothesis that use of internal visual imagery (IVI would be superior to external visual imagery (EVI for the performance of different slalom-based motor tasks. In Experiment 1, three groups of participants (IVI, EVI, and a control group performed a driving-simulation slalom task. The IVI group achieved significantly quicker lap times than EVI and the control group. In Experiment 2, participants performed a downhill running slalom task under both IVI and EVI conditions. Performance was again quickest in the IVI compared to EVI condition, with no differences in accuracy. Experiment 3 used the same group design as Experiment 1, but with participants performing a downhill ski-slalom task. Results revealed the IVI group to be significantly more accurate than the control group, with no significant differences in time taken to complete the task. These results support the beneficial effects of IVI for slalom-based tasks, and significantly advances our knowledge related to the differential effects of visual imagery perspectives on motor performance.

  7. Imagery Integration Team

    Science.gov (United States)

    Calhoun, Tracy; Melendrez, Dave

    2014-01-01

    The Human Exploration Science Office (KX) provides leadership for NASA's Imagery Integration (Integration 2) Team, an affiliation of experts in the use of engineering-class imagery intended to monitor the performance of launch vehicles and crewed spacecraft in flight. Typical engineering imagery assessments include studying and characterizing the liftoff and ascent debris environments; launch vehicle and propulsion element performance; in-flight activities; and entry, landing, and recovery operations. Integration 2 support has been provided not only for U.S. Government spaceflight (e.g., Space Shuttle, Ares I-X) but also for commercial launch providers, such as Space Exploration Technologies Corporation (SpaceX) and Orbital Sciences Corporation, servicing the International Space Station. The NASA Integration 2 Team is composed of imagery integration specialists from JSC, the Marshall Space Flight Center (MSFC), and the Kennedy Space Center (KSC), who have access to a vast pool of experience and capabilities related to program integration, deployment and management of imagery assets, imagery data management, and photogrammetric analysis. The Integration 2 team is currently providing integration services to commercial demonstration flights, Exploration Flight Test-1 (EFT-1), and the Space Launch System (SLS)-based Exploration Missions (EM)-1 and EM-2. EM-2 will be the first attempt to fly a piloted mission with the Orion spacecraft. The Integration 2 Team provides the customer (both commercial and Government) with access to a wide array of imagery options - ground-based, airborne, seaborne, or vehicle-based - that are available through the Government and commercial vendors. The team guides the customer in assembling the appropriate complement of imagery acquisition assets at the customer's facilities, minimizing costs associated with market research and the risk of purchasing inadequate assets. The NASA Integration 2 capability simplifies the process of securing one

  8. Auditory imagery: empirical findings.

    Science.gov (United States)

    Hubbard, Timothy L

    2010-03-01

    The empirical literature on auditory imagery is reviewed. Data on (a) imagery for auditory features (pitch, timbre, loudness), (b) imagery for complex nonverbal auditory stimuli (musical contour, melody, harmony, tempo, notational audiation, environmental sounds), (c) imagery for verbal stimuli (speech, text, in dreams, interior monologue), (d) auditory imagery's relationship to perception and memory (detection, encoding, recall, mnemonic properties, phonological loop), and (e) individual differences in auditory imagery (in vividness, musical ability and experience, synesthesia, musical hallucinosis, schizophrenia, amusia) are considered. It is concluded that auditory imagery (a) preserves many structural and temporal properties of auditory stimuli, (b) can facilitate auditory discrimination but interfere with auditory detection, (c) involves many of the same brain areas as auditory perception, (d) is often but not necessarily influenced by subvocalization, (e) involves semantically interpreted information and expectancies, (f) involves depictive components and descriptive components, (g) can function as a mnemonic but is distinct from rehearsal, and (h) is related to musical ability and experience (although the mechanisms of that relationship are not clear). PMID:20192565

  9. Imagery and Improvisation in Dance in the Schools.

    Science.gov (United States)

    Magruder, Ella

    1981-01-01

    Improvisation and imagery should be used to strengthen the thin bond between creativity and motor development in children. The approach to dance as an improvisational tool should be made more concrete when working with special populations such as mentally handicapped students. (JN)

  10. Coastal California Digital Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This digital ortho-imagery dataset is a survey of coastal California. The project area consists of approximately 3774 square miles. The project design of the...

  11. NOAA Emergency Response Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is in response to natural disasters. The aerial photography missions were conducted by the NOAA Remote Sensing Division. The...

  12. SHEBA Reconnaissance Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of optical band reconnaissance imagery of the Surface Heat Balance of the Arctic (SHEBA) site acquired between August 1997 and September...

  13. KINESTHETIC IMAGERY TRAINING OF FORCEFUL MUSCLE CONTRACTIONS INCREASES BRAIN SIGNAL AND MUSCLE STRENGTH

    Directory of Open Access Journals (Sweden)

    Wan X Yao

    2013-09-01

    Full Text Available The purpose of this study was to compare the effect of training using internal imagery (IMI; also known as kinesthetic imagery or first person imagery with that of external imagery (EMI; also known as third-person visual imagery of strong muscle contractions on voluntary muscle strengthening. Eighteen young, healthy subjects were randomly assigned to one of three groups (6 in each group: internal motor imagery (IMI, external motor imagery (EMI, or a no-practice control (CTRL group. Training lasted for 6 weeks (~15 min/day, 5 days/week. The participants’ right arm elbow-flexion strength, muscle electrical activity and movement-related cortical potential (MRCP were evaluated before and after training. Only the IMI group showed significant strength gained (10.8% while the EMI (4.8% and CTRL (-3.3% groups did not. Only the IMI group showed a significant elevation in MRCP on scalp locations over both the primary motor (M1 and supplementary motor cortices (EMI group over M1 only and this increase was significantly greater than that of EMI and CTRL groups. These results suggest that training by IMI of forceful muscle contractions was effective in improving voluntary muscle strength without physical exercise. We suggest that the IMI training likely strengthened brain-to-muscle (BTM command that may have improved motor unit recruitment and activation, and led to greater muscle output. Training by internal motor imagery of forceful muscle contractions may change the activity level of cortical motor control network, which may translate into greater descending command to the target muscle and increase its strength.

  14. Commercial imagery archive product development

    Science.gov (United States)

    Sakkas, Alysa

    1999-12-01

    The Lockheed Martin (LM) team had garnered over a decade of operational experience in digital imagery management and analysis for the US Government at numerous worldwide sites. Recently, it set out to create a new commercial product to serve the needs of large-scale imagery archiving and analysis markets worldwide. LM decided to provide a turnkey commercial solution to receive, store, retrieve, process, analyze and disseminate in 'push' or 'pull' modes components and adapted and developed its own algorithms to provide added functionality not commercially available elsewhere. The resultant product, Intelligent Library System, satisfies requirements for (a) a potentially unbounded, data archive automated workflow management for increased user productivity; (c) automatic tracking and management of files stored on shelves; (d) ability to ingest, process and disseminate data involves with bandwidths ranging up to multi-gigabit per second; (e) access through a thin client- to-server network environment; (f) multiple interactive users needing retrieval of filters in seconds from both archived images or in real time, and (g) scalability that maintains information throughput performance as the size of the digital library grows.

  15. 巨刺疗法联合运动想象对卒中患者肢体功能恢复影响%Clinical observation of opposing needling combined with motor imagery on extremity function rehabilitation in patients with stroke

    Institute of Scientific and Technical Information of China (English)

    尤阳

    2015-01-01

    目的:观察巨刺疗法联合运动想象对卒中患者肢体功能恢复的影响。方法将80例卒中后单侧肢体功能障碍患者随机分为2组。治疗组40例,予巨刺疗法联合运动想象治疗;对照组40例,单纯予巨刺疗法治疗。2组均以4周为1个疗程,连续治疗3个疗程后,采用 Fugl -Meyer 运动功能评分(FMA)评定患者运动功能,改良 Barthel 指数(MBI)评定患者日常生活活动能力,改良爱丁堡斯堪的那维亚评分(MESSS)进行神经功能缺损程度评定,并采用 MESSS 评分进行疗效比较。结果治疗组总有效率95.0%,对照组总有效率82.5%,2组总有效率比较差异有统计学意义(P <0.05);2组治疗后 FMA、MBI 及 MESSS 评分与本组治疗前比较差异均有统计学意义(P <0.05),FMA、MBI 评分升高,MESSS 评分降低,且治疗组改善均优于对照组(P <0.05)。结论巨刺疗法联合运动想象可以明显促进卒中后肢体功能障碍患者肢体功能恢复,疗效确切,二者联合相辅相成具有协同作用。%Objective To observe the effects of opposing needling combined with motor imagery on extremity function rehabilitation in patients with stroke .Methods 80 patients with unilateral limb dysfunction after stroke were randomly divided into two groups.40 patients in treatment group were treated by combined therapy of opposing nee -dling and motor imagery.40 patients in control group were treated by simple opposing needling .The course was 4 weeks in two groups.After continual 3 treatment courses,the motor function was evaluated by Fugl -Meyer assessment scale (FMA),the activity of daily living (ADL) was evaluated by modified Barthel index (MBI),the degree of neu-rologic impairment was evaluated by modified Edinburgh Scandinavia stroke scale (MESSS) as well as the clinical ef-ficacy comparison.Results There was statistical significance on total effective rate between

  16. Added Sugars

    Science.gov (United States)

    ... Restaurant Deciphering the Menu Ordering Your Meal Eating Fast Food Dining Out Tips by Cuisine Physical Activity Fitness ... Learn more about reading food labels . Limit your consumption of foods with high amounts of added sugars, ...

  17. Mental imagery for musical changes in loudness

    Directory of Open Access Journals (Sweden)

    Freya eBailes

    2012-12-01

    Full Text Available Musicians imagine music during mental rehearsal, when reading from a score, and while composing. An important characteristic of music is its temporality. Among the parameters that vary through time is sound intensity, perceived as patterns of loudness. Studies of mental imagery for melodies (i.e. pitch and rhythm show interference from concurrent musical pitch and verbal tasks, but how we represent musical changes in loudness is unclear. Theories suggest that our perceptions of loudness change relate to our perceptions of force or effort, implying a motor representation. An experiment was conducted to investigate the modalities that contribute to imagery for loudness change. Musicians performed a within-subjects loudness change recall task, comprising 48 trials. First, participants heard a musical scale played with varying patterns of loudness, which they were asked to remember. There followed an empty interval of 8 seconds (nil distractor control, or the presentation of a series of 4 sine tones, or 4 visual letters or 3 conductor gestures, also to be remembered. Participants then saw an unfolding score of the notes of the scale, during which they were to imagine the corresponding scale in their mind while adjusting a slider to indicate the imagined changes in loudness. Finally, participants performed a recognition task of the tone, letter or gesture sequence. Based on the motor hypothesis, we predicted that observing and remembering conductor gestures would impair loudness change scale recall, while observing and remembering tone or letter string stimuli would not. Results support this prediction, with loudness change recalled less accurately in the gestures condition than in the control condition. An effect of musical training suggests that auditory and motor imagery ability may be closely related to domain expertise.

  18. Efeito das terapias associadas de imagem motora e de movimento induzido por restrição na hemiparesia crônica: estudo de caso Effects of associated therapies of motor imagery and constraint-induced movement in chronic hemiparesis: a case study

    Directory of Open Access Journals (Sweden)

    Claudia Morais Trevisan

    2010-09-01

    Full Text Available Este estudo analisa os efeitos da associação das terapias de imagem motora e de movimento induzido por restrição na reeducação funcional do membro superior (MS de um paciente com deficit sensorial e motor determinado por acidente vascular encefálico (AVE. A terapia de imagem motora (IM consistiu em: 1o, estimulo visual do espelho, em 3 sessões semanais de 30 a 60 minutos por 4 semanas; e 2o, IM com prática mental, em 3 sessões semanais de 15 minutos por 3 semanas. Por último foi aplicada a terapia de indução ao movimento por restrição do membro superior não-afetado por 14 dias, em 10 dos quais foi feita atividade funcional do membro parético por 6 horas diárias. Além da avaliação clinica da sensibilidade e medida da força de preensão palmar, antes do tratamento e após cada modalidade de terapia foi medida a amplitude de movimentos de ombro, cotovelo e punho e aplicada a escala de avaliação motora (EAM. Os escores dos quatro momentos da coleta foram comparados estatisticamente. Após o tratamento os resultados mostraram diferença significativa (pThis study assessed the efficacy of the association of motor imagery and constraint-induced movement therapies in functional rehabilitation of the upper limb in a patient with somatosensory and motor deficits following stroke. Motor imagery (MI therapy, i.e., mental simulation of body image, consisted in: 1st, mirror visual stimulus, at three 30-60-minute weekly sessions for four weeks; and 2nd, MI with mental practice, at three 15-minute sessions per week for three weeks. Lastly, constraint-induced movement therapy was applied for 14 days, in 10 of which the patient underwent 6 hours daily of paretic limb functional training. The patient was assessed at baseline and at the end of each therapy modality as to clinical examination of sensation; hand grip strength; shoulder, elbow and wrist range of motion; and the motor assessment scale (MAS was applied. Scores obtained at the

  19. Wormholes in AdS

    OpenAIRE

    Maldacena, Juan; Maoz, Liat

    2004-01-01

    We construct a few Euclidean supergravity solutions with multiple boundaries. We consider examples where the corresponding boundary field theory is well defined on each boundary. We point out that these configurations are puzzling from the AdS/CFT point of view. A proper understanding of the AdS/CFT dictionary for these cases might yield some information about the physics of closed universes.

  20. 强制性使用运动疗法结合运动想象疗法治疗脑卒中单侧空间忽略患者的疗效观察%The effect of constraint-induced movement therapy combined with motor imagery on unilateral spatial neglect in stroke patients

    Institute of Scientific and Technical Information of China (English)

    徐睿华; 胡翔; 刘琦; 彭金良; 谢作文

    2010-01-01

    Objective To observe the effect of constraint-induced movement therapy combined with motor imagery on unilateral spatial neglect (USN) in stroke patients. Methods Fifty stroke patients with USN were randomly divided into a treatment group ( n = 27 ) and a control group ( n = 23 ). Both groups received routine physical therapy training, including with the Bobath technique and low frequency electrotherapy, while the treatment group received constraint-induced movement therapy and motor imagery in addition. All the patients were assessed with 4 scales of the regular USN assessment ( cancellation tests, line bisection tests, clock drawing tests,copying drawing tests) and with the Barthel index (BI) before and after 8 weeks of treatment. Results After 8 weeks of treatment, both groups' average USN assessments and Barthel indices improved significantly. Furthermore, both the USN results and the Barthel index scores in the treatment group were, on average, significantly better than those in the control group. Conclusion For USN stroke patients, constraint-induced movement therapy combined with motor imagery improves the symptoms of USN and ADL ability significantly better than routine physical therapy treatment alone.%目的 观察强制性运动疗法结合运动想象疗法治疗脑卒中单侧空间忽略患者的疗效.方法 将符合本研究入选标准的50例脑卒中单侧空间忽略患者分为治疗组27例和对照组23例.2组患者均于入院后接受常规康复治疗,治疗组在常规康复治疗的基础上加用强制性运动疗法及运动想象疗法.在治疗前和治疗8周后分别采用删除试验、平分直线法、画钟试验和临摹画图这4种常规单侧忽略检测方法和Barthel指数(BI)对患者进行评定.结果 治疗8周后,对照组患者的单侧忽略检测评分和BI评分较治疗前 改善,差异有统计学意义(P<0.05),治疗组较治疗前改善更为显著(P<0.01);2组间治疗后比较差

  1. Adding Ajax

    CERN Document Server

    Powers, Shelley

    2007-01-01

    Ajax can bring many advantages to an existing web application without forcing you to redo the whole thing. This book explains how you can add Ajax to enhance, rather than replace, the way your application works. For instance, if you have a traditional web application based on submitting a form to update a table, you can enhance it by adding the capability to update the table with changes to the form fields, without actually having to submit the form. That's just one example.Adding Ajax is for those of you more interested in extending existing applications than in creating Rich Internet Applica

  2. NAIP 2015 Imagery Feedback Map

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The NAIP 2015 Imagery Feedback map allows users to make comments and observations about the quality of the 2015 National Agriculture Imagery Program (NAIP)...

  3. Infrared Imagery of Solid Rocket Exhaust Plumes

    Science.gov (United States)

    Moran, Robert P.; Houston, Janice D.

    2011-01-01

    The Ares I Scale Model Acoustic Test program consisted of a series of 18 solid rocket motor static firings, simulating the liftoff conditions of the Ares I five-segment Reusable Solid Rocket Motor Vehicle. Primary test objectives included acquiring acoustic and pressure data which will be used to validate analytical models for the prediction of Ares 1 liftoff acoustics and ignition overpressure environments. The test article consisted of a 5% scale Ares I vehicle and launch tower mounted on the Mobile Launch Pad. The testing also incorporated several Water Sound Suppression Systems. Infrared imagery was employed during the solid rocket testing to support the validation or improvement of analytical models, and identify corollaries between rocket plume size or shape and the accompanying measured level of noise suppression obtained by water sound suppression systems.

  4. Solar Imagery - Chromosphere - Calcium

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of full-disk images of the sun in Calcium (Ca) II K wavelength (393.4 nm). Ca II K imagery reveal magnetic structures of the sun from about...

  5. Selective Efficacy of Static and Dynamic Imagery in Different States of Physical Fatigue.

    Science.gov (United States)

    Kanthack, Thiago Ferreira Dias; Guillot, Aymeric; Altimari, Leandro Ricardo; Nunez Nagy, Susana; Collet, Christian; Di Rienzo, Franck

    2016-01-01

    There is compelling evidence that motor imagery contributes to improved motor performance, and recent work showed that dynamic motor imagery (dMI) might provide additional benefits by comparison with traditional MI practice. However, the efficacy of motor imagery in different states of physical fatigue remains largely unknown, especially as imagery accuracy may be hampered by the physical fatigue states elicited by training. We investigated the effect of static motor imagery (sMI) and dMI on free-throw accuracy in 10 high-level basketball athletes, both in a non-fatigued state (Experiment 1) and immediately after an incremental running test completed until exhaustion (20 m shuttle run-test-Experiment 2). We collected perceived exhaustion and heart rate to quantify the subjective experience of fatigue and energy expenditure. We found that dMI brought better shooting performance than sMI, except when athletes were physically exhausted. These findings shed light on the conditions eliciting optimal use of sMI and dMI. In particular, considering that the current physical state affects body representation, performing dMI under fatigue may result in mismatches between actual and predicted body states.

  6. Selective Efficacy of Static and Dynamic Imagery in Different States of Physical Fatigue.

    Directory of Open Access Journals (Sweden)

    Thiago Ferreira Dias Kanthack

    Full Text Available There is compelling evidence that motor imagery contributes to improved motor performance, and recent work showed that dynamic motor imagery (dMI might provide additional benefits by comparison with traditional MI practice. However, the efficacy of motor imagery in different states of physical fatigue remains largely unknown, especially as imagery accuracy may be hampered by the physical fatigue states elicited by training. We investigated the effect of static motor imagery (sMI and dMI on free-throw accuracy in 10 high-level basketball athletes, both in a non-fatigued state (Experiment 1 and immediately after an incremental running test completed until exhaustion (20 m shuttle run-test-Experiment 2. We collected perceived exhaustion and heart rate to quantify the subjective experience of fatigue and energy expenditure. We found that dMI brought better shooting performance than sMI, except when athletes were physically exhausted. These findings shed light on the conditions eliciting optimal use of sMI and dMI. In particular, considering that the current physical state affects body representation, performing dMI under fatigue may result in mismatches between actual and predicted body states.

  7. Selective Efficacy of Static and Dynamic Imagery in Different States of Physical Fatigue

    Science.gov (United States)

    Ferreira Dias Kanthack, Thiago; Guillot, Aymeric; Ricardo Altimari, Leandro; Nunez Nagy, Susana; Collet, Christian; Di Rienzo, Franck

    2016-01-01

    There is compelling evidence that motor imagery contributes to improved motor performance, and recent work showed that dynamic motor imagery (dMI) might provide additional benefits by comparison with traditional MI practice. However, the efficacy of motor imagery in different states of physical fatigue remains largely unknown, especially as imagery accuracy may be hampered by the physical fatigue states elicited by training. We investigated the effect of static motor imagery (sMI) and dMI on free-throw accuracy in 10 high-level basketball athletes, both in a non-fatigued state (Experiment 1) and immediately after an incremental running test completed until exhaustion (20m shuttle run-test–Experiment 2). We collected perceived exhaustion and heart rate to quantify the subjective experience of fatigue and energy expenditure. We found that dMI brought better shooting performance than sMI, except when athletes were physically exhausted. These findings shed light on the conditions eliciting optimal use of sMI and dMI. In particular, considering that the current physical state affects body representation, performing dMI under fatigue may result in mismatches between actual and predicted body states. PMID:26930279

  8. Coastal Bend Texas Benthic Habitat Mapping Reprocessed DOQQ Aerial Imagery (NODC Accession 0086051)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Coastal Services Center purchased services to reprocess existing digital multi-spectral imagery (ADS-40) and create digital benthic...

  9. Imagery - Lake Ashtabula, ND - 2009 4-Band Orthophoto

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — 4-band aerial imagery was collected by Fugro Horizons using the Leica ADS40(SH52) camera with 30 percent side overlap on 8/26/09. The flight height was 9,600 feet...

  10. The Resting Motor Threshold - Restless or Resting?

    DEFF Research Database (Denmark)

    Karabanov, Anke Ninija; Raffin, Estelle Emeline; Siebner, Hartwig Roman

    2015-01-01

    , the RMT of the right first dorsal interosseus muscle was repeatedly determined using a threshold-hunting procedure while participants performed motor imagery and visual attention tasks with the right or left hand. Data were analyzed using repeated-measure ANOVA. Results RMT differed depending on which...

  11. Mental imagery of speech implicates two mechanisms of perceptual reactivation.

    Science.gov (United States)

    Tian, Xing; Zarate, Jean Mary; Poeppel, David

    2016-04-01

    Sensory cortices can be activated without any external stimuli. Yet, it is still unclear how this perceptual reactivation occurs and which neural structures mediate this reconstruction process. In this study, we employed fMRI with mental imagery paradigms to investigate the neural networks involved in perceptual reactivation. Subjects performed two speech imagery tasks: articulation imagery (AI) and hearing imagery (HI). We found that AI induced greater activity in frontal-parietal sensorimotor systems, including sensorimotor cortex, subcentral (BA 43), middle frontal cortex (BA 46) and parietal operculum (PO), whereas HI showed stronger activation in regions that have been implicated in memory retrieval: middle frontal (BA 8), inferior parietal cortex and intraparietal sulcus. Moreover, posterior superior temporal sulcus (pSTS) and anterior superior temporal gyrus (aSTG) was activated more in AI compared with HI, suggesting that covert motor processes induced stronger perceptual reactivation in the auditory cortices. These results suggest that motor-to-perceptual transformation and memory retrieval act as two complementary mechanisms to internally reconstruct corresponding perceptual outcomes. These two mechanisms can serve as a neurocomputational foundation for predicting perceptual changes, either via a previously learned relationship between actions and their perceptual consequences or via stored perceptual experiences of stimulus and episodic or contextual regularity. PMID:26889603

  12. Cerebral activations related to audition-driven performance imagery in professional musicians.

    Directory of Open Access Journals (Sweden)

    Robert Harris

    Full Text Available Functional Magnetic Resonance Imaging (fMRI was used to study the activation of cerebral motor networks during auditory perception of music in professional keyboard musicians (n = 12. The activation paradigm implied that subjects listened to two-part polyphonic music, while either critically appraising the performance or imagining they were performing themselves. Two-part polyphonic audition and bimanual motor imagery circumvented a hemisphere bias associated with the convention of playing the melody with the right hand. Both tasks activated ventral premotor and auditory cortices, bilaterally, and the right anterior parietal cortex, when contrasted to 12 musically unskilled controls. Although left ventral premotor activation was increased during imagery (compared to judgment, bilateral dorsal premotor and right posterior-superior parietal activations were quite unique to motor imagery. The latter suggests that musicians not only recruited their manual motor repertoire but also performed a spatial transformation from the vertically perceived pitch axis (high and low sound to the horizontal axis of the keyboard. Imagery-specific activations in controls were seen in left dorsal parietal-premotor and supplementary motor cortices. Although these activations were less strong compared to musicians, this overlapping distribution indicated the recruitment of a general 'mirror-neuron' circuitry. These two levels of sensori-motor transformations point towards common principles by which the brain organizes audition-driven music performance and visually guided task performance.

  13. Poor supplementary motor area activation differentiates auditory verbal hallucination from imagining the hallucination.

    Science.gov (United States)

    Raij, Tuukka T; Riekki, Tapani J J

    2012-01-01

    Neuronal underpinnings of auditory verbal hallucination remain poorly understood. One suggested mechanism is brain activation that is similar to verbal imagery but occurs without the proper activation of the neuronal systems that are required to tag the origins of verbal imagery in one's mind. Such neuronal systems involve the supplementary motor area. The supplementary motor area has been associated with awareness of intention to make a hand movement, but whether this region is related to the sense of ownership of one's verbal thought remains poorly known. We hypothesized that the supplementary motor area is related to the distinction between one's own mental processing (auditory verbal imagery) and similar processing that is attributed to non-self author (auditory verbal hallucination). To test this hypothesis, we asked patients to signal the onset and offset of their auditory verbal hallucinations during functional magnetic resonance imaging. During non-hallucination periods, we asked the same patients to imagine the hallucination they had previously experienced. In addition, healthy control subjects signaled the onset and offset of self-paced imagery of similar voices. Both hallucinations and the imagery of hallucinations were associated with similar activation strengths of the fronto-temporal language-related circuitries, but the supplementary motor area was activated more strongly during the imagery than during hallucination. These findings suggest that auditory verbal hallucination resembles verbal imagery in language processing, but without the involvement of the supplementary motor area, which may subserve the sense of ownership of one's own verbal imagery. PMID:24179739

  14. Poor supplementary motor area activation differentiates auditory verbal hallucination from imagining the hallucination☆

    Science.gov (United States)

    Raij, Tuukka T.; Riekki, Tapani J.J.

    2012-01-01

    Neuronal underpinnings of auditory verbal hallucination remain poorly understood. One suggested mechanism is brain activation that is similar to verbal imagery but occurs without the proper activation of the neuronal systems that are required to tag the origins of verbal imagery in one's mind. Such neuronal systems involve the supplementary motor area. The supplementary motor area has been associated with awareness of intention to make a hand movement, but whether this region is related to the sense of ownership of one's verbal thought remains poorly known. We hypothesized that the supplementary motor area is related to the distinction between one's own mental processing (auditory verbal imagery) and similar processing that is attributed to non-self author (auditory verbal hallucination). To test this hypothesis, we asked patients to signal the onset and offset of their auditory verbal hallucinations during functional magnetic resonance imaging. During non-hallucination periods, we asked the same patients to imagine the hallucination they had previously experienced. In addition, healthy control subjects signaled the onset and offset of self-paced imagery of similar voices. Both hallucinations and the imagery of hallucinations were associated with similar activation strengths of the fronto-temporal language-related circuitries, but the supplementary motor area was activated more strongly during the imagery than during hallucination. These findings suggest that auditory verbal hallucination resembles verbal imagery in language processing, but without the involvement of the supplementary motor area, which may subserve the sense of ownership of one's own verbal imagery. PMID:24179739

  15. A multimodal electroencephalogram visualization system can promote stroke patients′ motor imagery%在线多模态脑电数据可视化系统在脑卒中患者运动想象训练中的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘斯尧; 李明芬; 刘烨; 张丽清; 吴毅; 唐朝正; 贾杰

    2016-01-01

    Objective To explore the effect of a multimodal electroencephalogram ( EEG) data visualiza-tion system on the motor imagery ability of stroke survivors. Methods Twenty stroke patients were randomly di-vided into an experimental group and a control group, each of 10. Both groups were provided with brain-computer interface-based motor imagery ( MI) training. At the same time, the experimental group was monitored and guided using an online, multimodal EEG data visualization system developed in our department. The classification accuracy ( CA) and event-related desynchronization ( ERD) of the 2 groups′ motor imagery were compared before and after the treatment. Results Before the treatment, no significant differences in the average CA of MI were found be-tween the experiment group (50.92±2.08) and the control group (49.35±4.20)(P>0.05). After the treatment, however, the experimental group′s average CA had increased to (64.52±5.27), significantly higher than that of the control group (51.18±5.02). When the stroke patients imaged affected upper extremity movements, obvious ERD was observed in the α frequency around the bilateral central motor regions of both groups, especially in the experi-mental group, but without significant differences between the two groups. However, no significant changes were found in the ERD of theβwaves of the two groups( P>0.05) . Conclusion The proposed online multimodal elec-troencephalogram data visualization system can help stroke patients imagine movements actively. It is worth sprea-ding in clinical practice.%目的:观察本研究开发的新型在线多模态脑电数据可视化系统对脑卒中患者运动想象的影响。方法采用随机数字表法将20例脑卒中患者分为实验组与对照组。2组患者均给予基于脑-机接口( BCI)的运动想象训练,实验组同时通过在线多模态脑电数据可视化系统进行监测、指导,以实时调整其运动想象模式。比较2组患者治疗前

  16. Kinesthetic imagery of musical performance

    OpenAIRE

    Martin eLotze

    2013-01-01

    Musicians use different kinds of imagery. This review focuses on kinesthetic imagery, which has been shown to be an effective complement to actively playing an instrument. However, experience in actual movement performance seems to be a requirement for a recruitment of those brain areas representing movement ideation during imagery. An internal model of movement performance might be more differentiated when training has been more intense or simply performed more often. Therefore, with respect...

  17. Segmented motor drive - with multi-phase induction motor

    DEFF Research Database (Denmark)

    Bendixen, Flemming Buus

    This PhD project commences in modulation of motor drives, i.e. having the advantage of reducing the number of variants and improves the system reliability at error situations. Four different motor drive topologies with modular construction as common denominator are compared on a general level....... The multi-phase motor is selected for further analysis. The project is limited to examine if increasing the number of phases can improve the characteristics for induction motor drives. In the literature it is demonstrated that torque production in a six-phase motor can be increased, if a 3rd harmonic...... current with 1/6 amplitude is added to the 1st harmonic current. This claim is verified and the optimization of the motor design is extended to, beyond the stator tooth width, also to include the inner diameter of the stator. This means that the lamination sheet is optimized according to two geometrical...

  18. Effect of Motor Imagery Therapy Combined with Electro-acupuncture on Upper limb Function Recovery of Patients with Hemiplegia%运动想象疗法结合电针对卒中患者上肢功能的影响

    Institute of Scientific and Technical Information of China (English)

    张宇燕; 谢辉; 魏妮

    2016-01-01

    Objective:To observe the effect of motor imagery therapy combined with electro -acupuncture on upper limb function re-covery of patients with hemiplegia .Methods:60 cases of patients with hemiplegia were randomly divided into control group , 4 weeks for a course of treatment .Before and after the two courses of treatment , all patients were assisted with Fugl Meyer assessment ( FMA) ,modi-fied Barthel Index ( MBI) and activities of daily living scale .Results:After 8 weeks of treatment , the scores of assessment in all patients were significantly improved compared with before treatment with FMA and MBI ( P<0.05);and it is obvious improved in the comprehen-sive group compared with the control group and the electro -acupuncture group (P<0.05).Conclusion: It is effectively improved the function of upper limb in patients with hemiplegia after stroke by motor imagery therapy combined with electro -acupuncture .%目的:研究电针治疗结合运动想象疗法对脑卒中偏瘫患者上肢功能恢复的作用。方法:选择60例临床确诊的脑卒中偏瘫患者,予MINIMIZE随机分层软件随机分为对照组、电针组及综合组,每组20例。所有患者均接受常规药物治疗及常规康复治疗,电针组单纯增加电针治疗,综合组予电针结合运动想像疗法治疗。4周为1疗程,所有患者由同一治疗师分别于治疗前和治疗2个疗程后予Fugl-Meyer运动功能评定量表(FMA)评定上肢运动功能,予改良Barthel指数(MBI)量表评定日常生活活动能力。结果:治疗8周后,所有患者FMA及MBI评分均较治疗前有显著改善( P<0.05);而综合组各项指标的改善较对照组及电针组更加明显(P<0.05)。结论:电针结合运动想像疗法治疗,可以更有效地促进脑卒中偏瘫患者上肢功能的改善。

  19. Guided Imagery in Career Awareness.

    Science.gov (United States)

    Wilson, William C.; Eddy, John

    1982-01-01

    Suggests guided imagery can stimulate clients to become more aware of the role of personal values, attitudes, and beliefs in career decision making. Presents guidelines, examples, and implications to enable rehabilitation counselors to use guided imagery exercises in career counseling. (Author)

  20. Imagery Rescripting for Personality Disorders

    Science.gov (United States)

    Arntz, Arnoud

    2011-01-01

    Imagery rescripting is a powerful technique that can be successfully applied in the treatment of personality disorders. For personality disorders, imagery rescripting is not used to address intrusive images but to change the implicational meaning of schemas and childhood experiences that underlie the patient's problems. Various mechanisms that may…

  1. The use of technology-supported mental imagery in neurological rehabilitation: a research protocol.

    Science.gov (United States)

    Morganti, Francesca; Gaggioli, Andrea; Castelnuovo, Gianluca; Bulla, Daniel; Vettorello, Marco; Riva, Giuseppe

    2003-08-01

    The human brain can simulate motor actions without physically executing them, and there is a neuro-psychological relationship between imaging and performing a movement. These are shared opinions. In fact there is scientific evidence showing that the mental simulation of an action is correlated to a subliminal activation of the motor system. There is also evidence that virtual stimulation can enhance the acquisition of simple motor sequences. In some situations, virtual training was found to be as beneficial as real training and more beneficial than workbook and no training in teaching complex motor skills to people with learning disabilities. Moreover, studies of brain-injured hemiplegics patients suggest that these patients retain the ability to generate accurate motor images even of actions that they cannot perform. Combined with evidence indicating that motor imagery and motor planning share common neural mechanisms, these observations suggest that supporting mental imagery through non-immersive, low-cost virtual reality (VR) applications may be a potentially effective intervention in the rehabilitation of brain-injured patients. Starting from this background, our goal is to design and develop a new technique for the acquisition of new motor abilities- "imagery enhanced learning" (or I-learning)-to be used in neuro-psychological rehabilitation. A key feature of I-learning is the use of potentially low-cost, Virtual Reality enhanced technology to facilitate motor imagery creating a compelling sense of presence. This paper will discuss the rationale and a preliminary rehabilitation protocol for investigating mental imagery as a means of promoting motor recovery in patients with a neurological disorder. The treatment strategy aims at evoking powerful imaginative responses using an innovative technique which makes no attempt to simulate the real-world motor behavior, but draws the patient's attention to its underlying dynamic structure. This is done by displaying

  2. Playing piano in the mind--an fMRI study on music imagery and performance in pianists.

    Science.gov (United States)

    Meister, I G; Krings, T; Foltys, H; Boroojerdi, B; Müller, M; Töpper, R; Thron, A

    2004-05-01

    Reading of musical notes and playing piano is a very complex motor task which requires years of practice. In addition to motor skills, rapid and effective visuomotor transformation as well as processing of the different components of music like pitch, rhythm and musical texture are involved. The aim of the present study was the investigation of the cortical network which mediates music performance compared to music imagery in 12 music academy students playing the right hand part of a Bartok piece using functional magnetic resonance imaging (fMRI). In both conditions, fMRI activations of a bilateral frontoparietal network comprising the premotor areas, the precuneus and the medial part of Brodmann Area 40 were found. During music performance but not during imagery the contralateral primary motor cortex and posterior parietal cortex (PPC) bilaterally was active. This reflects the role of primary motor cortex for motor execution but not imagery and the higher visuomotor integration requirements during music performance compared to simulation. The notion that the same areas are involved in visuomotor transformation/motor planning and music processing emphasizes the multimodal properties of cortical areas involved in music and motor imagery in musicians.

  3. Poor supplementary motor area activation differentiates auditory verbal hallucination from imagining the hallucination ☆

    OpenAIRE

    Raij, Tuukka T.; Riekki, Tapani J.J.

    2012-01-01

    Neuronal underpinnings of auditory verbal hallucination remain poorly understood. One suggested mechanism is brain activation that is similar to verbal imagery but occurs without the proper activation of the neuronal systems that are required to tag the origins of verbal imagery in one's mind. Such neuronal systems involve the supplementary motor area. The supplementary motor area has been associated with awareness of intention to make a hand movement, but whether this region is related to th...

  4. Motor neglect.

    OpenAIRE

    Laplane, D.; Degos, J D

    1983-01-01

    Motor neglect is characterised by an underutilisation of one side, without defects of strength, reflexes or sensibility. Twenty cases of frontal, parietal and thalamic lesions causing motor neglect, but all without sensory neglect, are reported. It is proposed that the cerebral structures involved in motor neglect are the same as those for sensory neglect and for the preparation of movement. As in sensory neglect, the multiplicity of the structures concerned suggests that this interconnection...

  5. Watch me if you can: imagery ability moderates observational learning effectiveness

    OpenAIRE

    Gavin eLawrence; Nichola eCallow; Ross eRoberts

    2013-01-01

    Recent research has revealed similarities in brain activity during observational learning and motor execution. However, whilst action develops visual, motor and afferent representations during acquisition, action-observation has been proposed to only develop visual-spatial learning via visual representation. In addition, it has been suggested that the vividness of visual representations are determined by imagery ability. Thus, the purpose of the current investigation was to explore the possib...

  6. Online Ad Assignment with an Ad Exchange

    OpenAIRE

    Dvořák, Wolfgang; Henzinger, Monika

    2016-01-01

    Ad exchanges are becoming an increasingly popular way to sell advertisement slots on the internet. An ad exchange is basically a spot market for ad impressions. A publisher who has already signed contracts reserving advertisement impressions on his pages can choose between assigning a new ad impression for a new page view to a contracted advertiser or to sell it at an ad exchange. This leads to an online revenue maximization problem for the publisher. Given a new impression to sell decide whe...

  7. The Imagery Exchange (TIE): Open Source Imagery Management System

    Science.gov (United States)

    Alarcon, C.; Huang, T.; Thompson, C. K.; Roberts, J. T.; Hall, J. R.; Cechini, M.; Schmaltz, J. E.; McGann, J. M.; Boller, R. A.; Murphy, K. J.; Bingham, A. W.

    2013-12-01

    The NASA's Global Imagery Browse Service (GIBS) is the Earth Observation System (EOS) imagery solution for delivering global, full-resolution satellite imagery in a highly responsive manner. GIBS consists of two major subsystems, OnEarth and The Imagery Exchange (TIE). TIE is the GIBS horizontally scaled imagery workflow manager component, an Open Archival Information System (OAIS) responsible for orchestrating the acquisition, preparation, generation, and archiving of imagery to be served by OnEarth. TIE is an extension of the Data Management and Archive System (DMAS), a high performance data management system developed at the Jet Propulsion Laboratory by leveraging open source tools and frameworks, which includes Groovy/Grails, Restlet, Apache ZooKeeper, Apache Solr, and other open source solutions. This presentation focuses on the application of Open Source technologies in developing a horizontally scaled data system like DMAS and TIE. As part of our commitment in contributing back to the open source community, TIE is in the process of being open sourced. This presentation will also cover our current effort in getting TIE in to the hands of the community from which we benefited from.

  8. Dynamic aspects of musical imagery.

    Science.gov (United States)

    Halpern, Andrea R

    2012-04-01

    Auditory imagery can represent many aspects of music, such as the starting pitches of a tune or the instrument that typically plays it. In this paper, I concentrate on more dynamic, or time-sensitive aspects of musical imagery, as demonstrated in two recently published studies. The first was a behavioral study that examined the ability to make emotional judgments about both heard and imagined music in real time. The second was a neuroimaging study on the neural correlates of anticipating an upcoming tune, after hearing a cue tune. That study found activation of several sequence-learning brain areas, some of which varied with the vividness of the anticipated musical memory. Both studies speak to the ways in which musical imagery allows us to judge temporally changing aspects of the represented musical experience. These judgments can be quite precise, despite the complexity of generating the rich internal representations of imagery. PMID:22524360

  9. New percepts via mental imagery?

    Directory of Open Access Journals (Sweden)

    Fred Walter Mast

    2012-10-01

    Full Text Available We are able to extract detailed information from mental images that we were not explicitly aware of during encoding. For example, we can discover a new figure when we rotate a previously seen image in our mind. However, such discoveries are not really new but just new interpretations. In two recent publications, we have shown that mental imagery can lead to perceptual learning (Tartaglia et al., 2009, 2012. Observers imagined the central line of a bisection stimulus for thousands of trials. This training enabled observers to perceive bisection offsets that were invisible before training. Hence, it seems that perceptual learning via mental imagery leads to new percepts. We will argue, however, that these new percepts can occur only within known models. In this sense, perceptual learning via mental imagery exceeds new discoveries in mental images. Still, the effects of mental imagery on perceptual learning are limited. Only perception can lead to really new perceptual experience.

  10. APFO Historical Availability of Imagery

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The APFO Historical Availability ArcGIS Online web map provides an easy to use reference of what historical imagery is available by county from the Aerial...

  11. Investigating the effects of a sensorimotor rhythm-based BCI training on the cortical activity elicited by mental imagery

    Science.gov (United States)

    Toppi, J.; Risetti, M.; Quitadamo, L. R.; Petti, M.; Bianchi, L.; Salinari, S.; Babiloni, F.; Cincotti, F.; Mattia, D.; Astolfi, L.

    2014-06-01

    Objective. It is well known that to acquire sensorimotor (SMR)-based brain-computer interface (BCI) control requires a training period before users can achieve their best possible performances. Nevertheless, the effect of this training procedure on the cortical activity related to the mental imagery ability still requires investigation to be fully elucidated. The aim of this study was to gain insights into the effects of SMR-based BCI training on the cortical spectral activity associated with the performance of different mental imagery tasks. Approach. Linear cortical estimation and statistical brain mapping techniques were applied on high-density EEG data acquired from 18 healthy participants performing three different mental imagery tasks. Subjects were divided in two groups, one of BCI trained subjects, according to their previous exposure (at least six months before this study) to motor imagery-based BCI training, and one of subjects who were naive to any BCI paradigms. Main results. Cortical activation maps obtained for trained and naive subjects indicated different spectral and spatial activity patterns in response to the mental imagery tasks. Long-term effects of the previous SMR-based BCI training were observed on the motor cortical spectral activity specific to the BCI trained motor imagery task (simple hand movements) and partially generalized to more complex motor imagery task (playing tennis). Differently, mental imagery with spatial attention and memory content could elicit recognizable cortical spectral activity even in subjects completely naive to (BCI) training. Significance. The present findings contribute to our understanding of BCI technology usage and might be of relevance in those clinical conditions when training to master a BCI application is challenging or even not possible.

  12. Supplementary motor area deactivation impacts the recovery of hand function from severe peripheral nerve injury

    Institute of Scientific and Technical Information of China (English)

    Ye-chen Lu; Han-qiu Liu; Xu-yun Hua; Yun-dong Shen; Wen-dong Xu; Jian-guang Xu; Yu-dong Gu

    2016-01-01

    Although some patients have successful peripheral nerve regeneration, a poor recovery of hand function often occurs after peripheral nerve injury. It is believed that the capability of brain plasticity is crucial for the recovery of hand function. The supplementary motor area may play a key role in brain remodeling after peripheral nerve injury. In this study, we explored the activation mode of the supplementary motor area during a motor imagery task. We investigated the plasticity of the central nervous system after brachial plexus injury, using the motor imagery task. Results from functional magnetic resonance imaging showed that after brachial plexus injury, the motor imagery task for the affected limbs of the patients triggered no obvious activation of bilateral supplementary motor areas. This result indicates that it is dififcult to excite the supplementary motor areas of brachial plexus injury patients during a motor imagery task, thereby impacting brain remodeling. Deactivation of the supplementary motor area is likely to be a serious problem for brachial plexus injury patients in terms of preparing, initiating and executing certain movements, which may be partly responsible for the unsatisfactory clinical recovery of hand function.

  13. Investigating effects of different artefact types on motor imagery BCI

    DEFF Research Database (Denmark)

    Frølich, Laura; Winkler, Irene; Muller, Klaus-Robert;

    2015-01-01

    Artefacts in recordings of the electroencephalogram (EEG) are a common problem in Brain-Computer Interfaces (BCIs). Artefacts make it difficult to calibrate from training sessions, resulting in low test performance, or lead to artificially high performance when unintentionally used for BCI control...

  14. Electroencephalogram processing in Motor Imagery Based BCI: A tutorial

    NARCIS (Netherlands)

    Garcia Molina, G.

    2008-01-01

    Brain-computer interfaces (BCIs) have been emerging during the last twenty years, as plausible alternatives for offering communication and control to physically challenged people. Yet, the idea of achieving control by simply thinking is appealing to a wider range of users. Availability, lower cost,

  15. Polarised black holes in AdS

    Science.gov (United States)

    Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-06-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.

  16. Motor homopolar

    OpenAIRE

    2007-01-01

    Mostramos la construcción de un modelo de motor homopolar, uno de los más antiguos tipos de motores eléctricos. Se caracterizan porque el campo magnético del imán mantiene siempre la misma polaridad (de ahí su nombre, del griego homos, igual), de modo que, cuando una corriente eléctrica atraviesa el campo magnético, aparece una fuerza que hace girar los elementos no fijados mecánicamente. En el sencillísimo motor homopolar colgado (Schlichting y Ucke 2004), el imán puede girar ...

  17. Application of stepping motor

    International Nuclear Information System (INIS)

    This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

  18. Polarised Black Holes in AdS

    CERN Document Server

    Costa, Miguel S; Oliveira, Miguel; Penedones, João; Santos, Jorge E

    2015-01-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global $AdS_{4}$ with conformal boundary $S^{2}\\times\\mathbb{R}_{t}$. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic $AdS$ behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an $AdS$ soliton that includes the full backreaction of the electric field on the $AdS$ geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both $AdS$ soliton and black hole phases. The corresponding phase diagram generalizes the Hawkin...

  19. Mental imagery of speech and movement implicates the dynamics of internal forward models

    Directory of Open Access Journals (Sweden)

    Xing eTian

    2010-10-01

    Full Text Available The classical concept of efference copies in the context of internal forward models has stimulated productive research in cognitive science and neuroscience. There are compelling reasons to argue for such a mechanism, but finding direct evidence in the human brain remains difficult. Here we investigate the dynamics of internal forward models from an unconventional angle: mental imagery, assessed while recording high temporal resolution neuronal activity using magnetoencephalography (MEG. We compare two overt and covert tasks; our covert, mental imagery tasks are unconfounded by overt input/output demands – but in turn necessitate the development of appropriate multi-dimensional topographic analyses. Finger tapping (studies 1-2 and speech experiments (studies 3-5 provide temporally constrained results that implicate the estimation of an efference copy. We suggest that one internal forward model over parietal cortex subserves the kinesthetic feeling in motor imagery. Secondly, observed auditory neural activity ~170 ms after motor estimation in speech experiments (studies 3-5 demonstrates the anticipated auditory consequences of planned motor commands in a second internal forward model in imagery of speech production. Our results provide neurophysiological evidence from the human brain in favor of internal forward models deploying efference copies in somatosensory and auditory cortex, in finger tapping and speech production tasks, respectively, and also suggest the dynamics and sequential updating structure of internal forward models.

  20. Ad Hoc网络%Ad Hoc Network

    Institute of Scientific and Technical Information of China (English)

    王海涛

    2005-01-01

    首先介绍了Ad Hoc网络的基本概念、技术特点以及关键技术等,然后较为全面地归纳了Ad Hoc网络的典型应用,最后讨论了Ad Hoc网络的发展趋势和有待解决的问题.

  1. NOAA's Use of High-Resolution Imagery

    Science.gov (United States)

    Hund, Erik

    2007-01-01

    NOAA's use of high-resolution imagery consists of: a) Shoreline mapping and nautical chart revision; b) Coastal land cover mapping; c) Benthic habitat mapping; d) Disaster response; and e) Imagery collection and support for coastal programs.

  2. AgSat Imagery Collection Footprints

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — The AgSat Imagery Collection Footprints map shows the imagery footprints which have been collected under the USDA satellite blanket purchase agreement. Click on a...

  3. Publicly Available IKONOS-2 Commercial Imagery

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS Commercial Data Purchases (UCDP) imagery collection is an archive of commercial remote sensing imagery from several different commercial vendors. The UCDP...

  4. Baby Skyrmions in AdS

    OpenAIRE

    Elliot-Ripley, Matthew; Winyard, Thomas

    2015-01-01

    We study the baby Skyrme model in a pure AdS background without a mass term. The tail decays and scalings of massless radial solutions are demonstrated to take a similar form to those of the massive flat space model, with the AdS curvature playing a similar role to the flat space pion mass. We also numerically find minimal energy solutions for a range of higher topological charges and find that they form concentric ring-like solutions. Popcorn transitions (named in analogy with studies of toy...

  5. Perceptual evaluation of color transformed multispectral imagery

    NARCIS (Netherlands)

    Toet, A.; Jong, M.J. de; Hogervorst, M.A.; Hooge, I.T.C.

    2014-01-01

    Color remapping can give multispectral imagery a realistic appearance. We assessed the practical value of this technique in two observer experiments using monochrome intensified (II) and long-wave infrared (IR) imagery, and color daylight (REF) and fused multispectral (CF) imagery. First, we investi

  6. Perceptual evaluation of color transformed multispectral imagery

    Science.gov (United States)

    Toet, Alexander; de Jong, Michael J.; Hogervorst, Maarten A.; Hooge, Ignace T. C.

    2014-04-01

    Color remapping can give multispectral imagery a realistic appearance. We assessed the practical value of this technique in two observer experiments using monochrome intensified (II) and long-wave infrared (IR) imagery, and color daylight (REF) and fused multispectral (CF) imagery. First, we investigated the amount of detail observers perceive in a short timespan. REF and CF imagery yielded the highest precision and recall measures, while II and IR imagery yielded significantly lower values. This suggests that observers have more difficulty in extracting information from monochrome than from color imagery. Next, we measured eye fixations during free image exploration. Although the overall fixation behavior was similar across image modalities, the order in which certain details were fixated varied. Persons and vehicles were typically fixated first in REF, CF, and IR imagery, while they were fixated later in II imagery. In some cases, color remapping II imagery and fusion with IR imagery restored the fixation order of these image details. We conclude that color remapping can yield enhanced scene perception compared to conventional monochrome nighttime imagery, and may be deployed to tune multispectral image representations such that the resulting fixation behavior resembles the fixation behavior corresponding to daylight color imagery.

  7. Perceptual evaluation of colorized nighttime imagery

    Science.gov (United States)

    Toet, Alexander; de Jong, Michael J.; Hogervorst, Maarten A.; Hooge, Ignace T. C.

    2014-02-01

    We recently presented a color transform that produces fused nighttime imagery with a realistic color appearance (Hogervorst and Toet, 2010, Information Fusion, 11-2, 69-77). To assess the practical value of this transform we performed two experiments in which we compared human scene recognition for monochrome intensified (II) and longwave infrared (IR) imagery, and color daylight (REF) and fused multispectral (CF) imagery. First we investigated the amount of detail observers can perceive in a short time span (the gist of the scene). Participants watched brief image presentations and provided a full report of what they had seen. Our results show that REF and CF imagery yielded the highest precision and recall measures, while both II and IR imagery yielded significantly lower values. This suggests that observers have more difficulty extracting information from monochrome than from color imagery. Next, we measured eye fixations of participants who freely explored the images. Although the overall fixation behavior was similar across image modalities, the order in which certain details were fixated varied. Persons and vehicles were typically fixated first in REF, CF and IR imagery, while they were fixated later in II imagery. In some cases, color remapping II imagery and fusion with IR imagery restored the fixation order of these image details. We conclude that color remapping can yield enhanced scene perception compared to conventional monochrome nighttime imagery, and may be deployed to tune multispectral image representation such that the resulting fixation behavior resembles the fixation behavior for daylight color imagery.

  8. Joint selection of time segment and frequency band for classifying multiclass motor imagery EEG data%基于时间段和频带联合选择的多类运动想象脑电数据分类

    Institute of Scientific and Technical Information of China (English)

    魏庆国; 韩仁香

    2014-01-01

    The time and frequency intervals of EEG signals have significant influence on the classification performance of brain-computer interfaces(BCIs).Based on joint selection of time segment and frequency band,a new classification algorithm was proposed to classify multiclass motor imagery BCI systems in this paper.A sliding window was firstly used to segment the EEG signals in time and frequency domain.Then the multiclass common spatial pattern(CSP)was utilized for feature extraction in each pair of time and fre-quency segment.Finally we employed the k-nearest neighbor(KNN)to classify the extracted feature sig-nals.Cross-validated classification accuracy was used for the selection criterion of optimal time and frequen-cy segment.The performance of the algorithm was tested and compared with those of three typical algo-rithms by a classification experiment on a four-class data set.The results suggested that the algorithm could achieve a highest accuracy rate,validating the effectiveness of the j oint selection of time segment and frequency band based classification algorithm.%脑电信号的时间和频率间隔选择对脑机接口的分类性能具有重要的影响。针对多类运动想象脑机接口系统,提出一个新的基于时间段和频带联合选择的分类算法。该算法首先使用滑动窗将运动想象产生的脑电信号在时域和频域进行分割,然后在每一对截取的时间段和频段,使用多类共空域模式算法提取脑电特征信号,最后使用k-最近邻算法对特征信号进行分类。交叉验证的分类识别率作为最优时间段和频带的选择标准。使用一个四类数据集对这个分类算法的性能进行了测试。与现有的3个典型算法比较,这个算法取得了最高的平均分类正确率,证实了这个基于时间段和频带联合选择的分类算法的有效性。

  9. Eternal Black Holes in AdS

    OpenAIRE

    Maldacena, Juan M.

    2001-01-01

    We propose a dual non-perturbative description for maximally extended Schwarzschild Anti-de-Sitter spacetimes. The description involves two copies of the conformal field theory associated to the AdS spacetime and an initial entangled state. In this context we also discuss a version of the information loss paradox and its resolution.

  10. Current status of AdS instability

    CERN Document Server

    CERN. Geneva

    2016-01-01

    arXiv:1403.6471 and thoroughly developed in arXiv:1407.6273. On the other hand the negative cosmological constant allows for the existence of stable, time-periodic, asymptotically AdS solutions of Einstein equations [arXiv:1303.3186].

  11. AdS braneworld with Backreaction

    CERN Document Server

    Bilic, Neven

    2014-01-01

    We review the tachyon model derived from the dynamics of a 3-brane moving in the AdS5 bulk. The bulk geometry is based on the Randall-Sundrum II model extended to include the radion. The effective tachyon Lagrangian is modified due to the back-reaction of the brane on the bulk geometry.

  12. Motor prediction in Brain-Computer Interfaces for controlling mobile robots.

    Science.gov (United States)

    Geng, Tao; Gan, John Q

    2008-01-01

    EEG-based Brain-Computer Interface (BCI) can be regarded as a new channel for motor control except that it does not involve muscles. Normal neuromuscular motor control has two fundamental components: (1) to control the body, and (2) to predict the consequences of the control command, which is called motor prediction. In this study, after training with a specially designed BCI paradigm based on motor imagery, two subjects learnt to predict the time course of some features of the EEG signals. It is shown that, with this newly-obtained motor prediction skill, subjects can use motor imagery of feet to directly control a mobile robot to avoid obstacles and reach a small target in a time-critical scenario.

  13. Dialectical Imagery and Postmodern Research

    Science.gov (United States)

    Davison, Kevin G.

    2006-01-01

    This article suggests utilizing dialectical imagery, as understood by German social philosopher Walter Benjamin, as an additional qualitative data analysis strategy for research into the postmodern condition. The use of images mined from research data may offer epistemological transformative possibilities that will assist in the demystification of…

  14. Superradiant instability in AdS

    CERN Document Server

    Ganchev, Bogdan

    2016-01-01

    The phenomenon of superradiance in the context of asymptotically global AdS spacetimes is investigated with particular accent on its effect on the stability of the systems under consideration. To this end, the concept of an asymptotically AdS spacetime is explained, together with its implications on the boundary conditions at $\\mathcal{I}$, as well as the Newman-Penrose-Teukolsky formalism, whereby the Teukolsky master equation in a most general form for Kerr-AdS is given. Furthermore, work done in the cases of RN-AdS and Kerr-AdS is laid out in a concise manner, putting emphasis on the important steps taken in determining the endpoint of the superradiant instability in the two configurations. For the former this turns out to be a black hole with reduced charge and a static charged scalar condensate around it, whereas for the latter two of the more probable outcomes are presented, both of which imply a violation of one of the cosmic censorships.

  15. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop...

  16. Motor Magnates

    Institute of Scientific and Technical Information of China (English)

    ISABEL DING

    2008-01-01

    @@ The automotive industry is often seen as a man's world. Wang Fengying (王风英) begs to differ. The 38-year-old has presided over Great Wall Motors (长城汽车), the leading pick-up truck and Sport Utility Vehicle(SUV) manufacturer in China for the past five years.

  17. Motor radiculopathy

    OpenAIRE

    Khan, Afsha; Camilleri, Jeremy

    2012-01-01

    A 48-year-old immunosuppressed woman presented to a rheumatology follow-up clinic after suffering from herpes zoster infection. She had manifestations of foot drop 3 months after the initial infection. She was diagnosed with motor radiculopathy following herpes zoster infection that was effectively managed by physiotherapy and amitriptyline.

  18. Instability corners in AdS space

    CERN Document Server

    Dimitrakopoulos, Fotios V; Lippert, Matthew; Yang, I-Sheng

    2014-01-01

    We investigate whether arbitrarily small perturbations in global AdS space are generically unstable and collapse into black holes on the time scale set by gravitational interactions. We argue that current evidence, combined with our analysis, strongly suggests that a set of nonzero measure in the space of initial conditions does not collapse on this time scale. On the other hand, existing results do not provide an equally strong indication whether the unstable solutions also form a set of nonzero measure. We perform an analysis in position space to address this puzzle, and our formalism allows us to directly address the vanishing-amplitude limit. We show that gravitational self-interaction leads to tidal deformations which are equally likely to focus or defocus energy, and we sketch the phase diagram accordingly. We also clarify the connection between gravitational evolution in global AdS and holographic thermalization.

  19. Baby Skyrmions in AdS

    CERN Document Server

    Elliot-Ripley, Matthew

    2015-01-01

    We study the baby Skyrme model in a pure AdS background without a mass term. The tail decays and scalings of massless radial solutions are demonstrated to take a similar form to those of the massive flat space model, with the AdS curvature playing a similar role to the flat space pion mass. We also numerically find minimal energy solutions for a range of higher topological charges and find that they form concentric ring-like solutions. Popcorn transitions (named in analogy with studies of toy models of holographic QCD) from an n layer to an n+1-layer configuration are observed at topological charges 9 and 27 and further popcorn transitions for higher charges are predicted. Finally, a point-particle approximation for the model is derived and used to successfully predict the ring structures and popcorn transitions for higher charge solitons.

  20. Advanced Motors

    Energy Technology Data Exchange (ETDEWEB)

    Knoth, Edward A.; Chelluri, Bhanumathi; Schumaker, Edward J.

    2012-12-14

    Project Summary Transportation energy usage is predicted to increase substantially by 2020. Hybrid vehicles and fuel cell powered vehicles are destined to become more prominent as fuel prices rise with the demand. Hybrid and fuel cell vehicle platforms are both dependent on high performance electric motors. Electric motors for transportation duty will require sizeable low-speed torque to accelerate the vehicle. As motor speed increases, the torque requirement decreases which results in a nearly constant power motor output. Interior permanent magnet synchronous motors (IPMSM) are well suited for this duty. , , These rotor geometries are configured in straight lines and semi circular arc shapes. These designs are of limited configurations because of the lack of availability of permanent magnets of any other shapes at present. We propose to fabricate rotors via a novel processing approach where we start with magnet powders and compact them into a net shape rotor in a single step. Using this approach, widely different rotor designs can be implemented for efficiency. The current limitation on magnet shape and thickness will be eliminated. This is accomplished by co-filling magnet and soft iron powders at specified locations in intricate shapes using specially designed dies and automatic powder filling station. The process fundamentals for accomplishing occurred under a previous Applied Technology Program titled, “Motors and Generators for the 21st Century”. New efficient motor designs that are not currently possible (or cost prohibitive) can be accomplished by this approach. Such an approach to

  1. AdS solutions through transgression

    Energy Technology Data Exchange (ETDEWEB)

    Donos, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Gauntlett, J.P. [Imperial College, London (United Kingdom). Blackett Lab.]|[Imperial College, London (United Kingdom). The Institute for Mathematical Sciences; Kim, Nakwoo [Kyung Hee Univ., Seoul (Korea). Dept. of Physics and Research Inst. of Basic Science

    2008-07-15

    We present new classes of explicit supersymmetric AdS{sub 3} solutions of type IIB supergravity with non-vanishing five-form flux and AdS{sub 2} solutions of D=11 supergravity with electric four-form flux. The former are dual to two-dimensional SCFTs with (0,2) supersymmetry and the latter to supersymmetric quantum mechanics with two supercharges. We also investigate more general classes of AdS{sub 3} solutions of type IIB supergravity and AdS{sub 2} solutions of D=11 supergravity which in addition have non-vanishing three-form flux and magnetic four-form flux, respectively. The construction of these more general solutions makes essential use of the Chern-Simons or ''transgression'' terms in the Bianchi identity or the equation of motion of the field strengths in the supergravity theories. We construct infinite new classes of explicit examples and for some of the type IIB solutions determine the central charge of the dual SCFTs. The type IIB solutions with non-vanishing three-form flux that we construct include a two-torus, and after two T-dualities and an S-duality, we obtain new AdS3 solutions with only the NS fields being non-trivial. (orig.)

  2. The application and efficacy of combined neurofeedback therapy and imagery training in adolescents with Tourette syndrome.

    Science.gov (United States)

    Zhuo, Chuanjun; Li, Li

    2014-07-01

    We aimed to examine the effectiveness of combined neurofeedback therapy and imagery training in adolescent patients with refractory Tourette syndrome. Two patients, aged respectively 14 and 16 years, had been treated with haloperidol and tiapride; however, this medication was ineffective and accompanied by intolerable side effects. In this study, the patients completed 80 sessions of neurofeedback treatment followed by imagery training. The patients were assessed with behavior rating scales both before and after the treatment as well as during follow-up examinations to evaluate the effect of the combined therapy. Patients showed significant improvement in motor tic and vocal tic symptoms, exemplified by a reduction in the frequency and intensity of tics, indicating that neurofeedback, together with imagery training, has a positive therapeutic effect on adolescent patients with medication-refractory Tourette syndrome.

  3. USE OF IMAGERY AND METAPHOR IN ARAVIND ADIGAS THE WHITE TIGER

    Directory of Open Access Journals (Sweden)

    Sushama Kasbekar

    2011-10-01

    highlights how this imagery and metaphor has been used by the writer to bring out the thematic rich and poor divide or the servitude of the poor and overbearing opulence of the rich. The metaphors give added value to the themes and the characters and provide an immediate verbal picture.

  4. Refined Holographic Entanglement Entropy for the AdS Solitons and AdS black Holes

    CERN Document Server

    Ishihara, Masafumi; Ning, Bo

    2012-01-01

    We consider the refinement of the holographic entanglement entropy on a disk region for the holographic dual theories to the AdS solitons and AdS black holes, including the corrected ones by the Gauss-Bonnet term. The AdS soliton is dual to a gapped system with an IR fixed-point. The refinement is obtained by extracting the UV-independent piece of the holographic entanglement entropy. We then study the renormalization group (RG) flow of the refinement by tuning the linear size of the chosen disk region. Our main results are (i) the RG flow of the refinement decreases monotonically for most of the cases; (ii) there is no topological entanglement entropy for AdS$_5$ soliton even with Gauss-Bonnet correction; (iii) for the AdS black holes, the refinement obeys the volume law at IR regime, and the transition between UV and IR regimes is a smooth crossover; however, the crossover will turn into phase transition by the Gauss-Bonnet correction; (iv) for the AdS solitons, there are discontinuous phase transitions bet...

  5. Refined holographic entanglement entropy for the AdS solitons and AdS black holes

    International Nuclear Information System (INIS)

    We consider the refinement of the holographic entanglement entropy for the holographic dual theories to the AdS solitons and AdS black holes, including the corrected ones by the Gauss–Bonnet term. The refinement is obtained by extracting the UV-independent piece of the holographic entanglement entropy, the so-called renormalized entanglement entropy which is independent of the choices of UV cutoff. Our main results are: (i) the renormalized entanglement entropies of the AdSd+1 soliton for d=4,5 are neither monotonically decreasing along the RG flow nor positive-definite, especially around the deconfinement/confinement phase transition; (ii) there is no topological entanglement entropy for AdS5 soliton even with Gauss–Bonnet correction; (iii) for the AdS black holes, the renormalized entanglement entropy obeys an expected volume law at IR regime, and the transition between UV and IR regimes is a smooth crossover even with Gauss–Bonnet correction; (iv) based on AdS/MERA conjecture, we postulate that the IR fixed-point state for the non-extremal AdS soliton is a trivial product state

  6. Predicting AD conversion

    DEFF Research Database (Denmark)

    Liu, Yawu; Mattila, Jussi; Ruiz, Miguel �ngel Mu�oz;

    2013-01-01

    To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool) and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA) on MRI...

  7. Bistatic SAR: Imagery & Image Products.

    Energy Technology Data Exchange (ETDEWEB)

    Yocky, David A.; Wahl, Daniel E.; Jakowatz, Charles V,

    2014-10-01

    While typical SAR imaging employs a co-located (monostatic) RADAR transmitter and receiver, bistatic SAR imaging separates the transmitter and receiver locations. The transmitter and receiver geometry determines if the scattered signal is back scatter, forward scatter, or side scatter. The monostatic SAR image is backscatter. Therefore, depending on the transmitter/receiver collection geometry, the captured imagery may be quite different that that sensed at the monostatic SAR. This document presents imagery and image products formed from captured signals during the validation stage of the bistatic SAR research. Image quality and image characteristics are discussed first. Then image products such as two-color multi-view (2CMV) and coherent change detection (CCD) are presented.

  8. Kinesthetic Imagery and Choreographic Praxis

    OpenAIRE

    Ando, Taku

    2014-01-01

    The aim of this research project is to investigate the practical application of some ideas regarding how dancers can create certain types of mental images that are formed through their kinesthetic perception, which we shall define as ‘kinesthetic images’, and to study the spatial or geometric structures that are often utilized in choreographic and pedagogical dance praxis. The term kinesthetic image is a label for a certain types of mental imagery that are generated through the sensation of m...

  9. Winding Strings in AdS_3

    CERN Document Server

    Minces, P; Minces, Pablo; Nunez, Carmen

    2006-01-01

    Correlation functions of one-unit spectral flowed states in string theory on AdS_3 are considered. We present a formalism which allows to explicitly find the modified Knizhnik-Zamolodchikov and null vector equations to be satisfied by amplitudes of states in w=1 sectors. We give a precise prescription to solve this system of linear differential equations in cases that are relevant to obtain three and four point functions involving spectral flowed string states. We specifically compute three point functions with two and three one-unit spectral flowed operators and also discuss four point functions.

  10. Hereditary motor-sensory, motor, and sensory neuropathies in childhood.

    Science.gov (United States)

    Landrieu, Pierre; Baets, Jonathan; De Jonghe, Peter

    2013-01-01

    Hereditary neuropathies (HN) are categorized according to clinical presentation, pathogenic mechanism based on electrophysiology, genetic transmission, age of occurrence, and, in selected cases, pathological findings. The combination of these parameters frequently orients towards specific genetic disorders. Ruling out a neuropathy secondary to a generalized metabolic disorder remains the first pediatric concern. Primary, motor-sensory are the most frequent HN and are dominated by demyelinating AD forms (CMT1). Others are demyelinating AR forms, axonal AD/AR forms, and forms with "intermediate" electrophysiological phenotype. Pure motor HN represent40 genes with various biological functions have been found responsible for HN. Many are responsible for various phenotypes, including some without the polyneuropathic trait: for the pediatric neurologist, phenotype/genotype correlations constitute a permanent bidirectional exercise.

  11. Commercial imagery archive, management, exploitation, and distribution product development

    Science.gov (United States)

    Hollinger, Bruce; Sakkas, Alysa

    1999-12-01

    The Lockheed Martin (LM) team had garnered over a decade of operational experience on the U.S. Government's IDEX II (Imagery Dissemination and Exploitation) system. Recently, it set out to create a new commercial product to serve the needs of large-scale imagery archiving and analysis markets worldwide. LM decided to provide a turnkey commercial solution to receive, store, retrieve, process, analyze and disseminate in 'push' or 'pull' modes imagery, data and data products using a variety of sources and formats. LM selected 'best of breed' hardware and software components and adapted and developed its own algorithms to provide added functionality not commercially available elsewhere. The resultant product, Intelligent Library System (ILS)TM, satisfies requirements for (a) a potentially unbounded, data archive (5000 TB range) (b) automated workflow management for increased user productivity; (c) automatic tracking and management of files stored on shelves; (d) ability to ingest, process and disseminate data volumes with bandwidths ranging up to multi- gigabit per second; (e) access through a thin client-to-server network environment; (f) multiple interactive users needing retrieval of files in seconds from both archived images or in real time, and (g) scalability that maintains information throughput performance as the size of the digital library grows.

  12. Commercial imagery archive, management, exploitation, and distribution project development

    Science.gov (United States)

    Hollinger, Bruce; Sakkas, Alysa

    1999-10-01

    The Lockheed Martin (LM) team had garnered over a decade of operational experience on the U.S. Government's IDEX II (Imagery Dissemination and Exploitation) system. Recently, it set out to create a new commercial product to serve the needs of large-scale imagery archiving and analysis markets worldwide. LM decided to provide a turnkey commercial solution to receive, store, retrieve, process, analyze and disseminate in 'push' or 'pull' modes imagery, data and data products using a variety of sources and formats. LM selected 'best of breed' hardware and software components and adapted and developed its own algorithms to provide added functionality not commercially available elsewhere. The resultant product, Intelligent Library System (ILS)TM, satisfies requirements for (1) a potentially unbounded, data archive (5000 TB range) (2) automated workflow management for increased user productivity; (3) automatic tracking and management of files stored on shelves; (4) ability to ingest, process and disseminate data volumes with bandwidths ranging up to multi- gigabit per second; (5) access through a thin client-to-server network environment; (6) multiple interactive users needing retrieval of files in seconds from both archived images or in real time, and (7) scalability that maintains information throughput performance as the size of the digital library grows.

  13. Effects of mental imagery styles on shoulder and hip rotations during preparation of pirouettes.

    Science.gov (United States)

    Golomer, Eveline; Bouillette, Arnaud; Mertz, Caroline; Keller, Jean

    2008-07-01

    To analyze individual behavior in spatial navigation especially for pirouette preparations (complete whole-body rotations), the authors studied horizontal shoulder-hip interactions under 2 constraints: postural (right and left supporting legs [SL]) and spatial (clockwise [CW] and counterclockwise [CCW]). They performed kinematic analysis at the start and end of the shoulder-hip horizontal rotations (run-up) with regard to imagery of motor actions. On the basis of the Vividness of Movement Imagery Questionnaire, they classified 8 female expert ballet dancers and 7 untrained female participants according to their movement imagery style (kinesthetic and visual). At the run-up's end, the shoulders initiated the turn independently of SL but differently depending on training: CW for dancers and CCW for untrained participants (their commonly used direction). Kinesthetic and mixed imagery styles prevailed in dancers, whereas simply a mixed style appeared among untrained participants. Thus, dance training enhances the imagery of kinesthetic sensation and influences the choice of spatial direction, facilitating the body-space interaction. PMID:18628105

  14. User Validation of VIIRS Satellite Imagery

    OpenAIRE

    Don Hillger; Tom Kopp; Curtis Seaman; Steven Miller; Dan Lindsey; Eric Stevens; Jeremy Solbrig; William Straka III; Melissa Kreller; Arunas Kuciauskas; Amanda Terborg

    2015-01-01

    Visible/Infrared Imaging Radiometer Suite (VIIRS) Imagery from the Suomi National Polar-orbiting Partnership (S-NPP) satellite is the finest spatial resolution (375 m) multi-spectral imagery of any operational meteorological satellite to date. The Imagery environmental data record (EDR) has been designated as a Key Performance Parameter (KPP) for VIIRS, meaning that its performance is vital to the success of a series of Joint Polar Satellite System (JPSS) satellites that will carry this instr...

  15. Alcohol imagery on New Zealand television

    OpenAIRE

    Reeder Anthony I; Ketchel Juanita; McGee Rob

    2007-01-01

    Abstract Background To examine the extent and nature of alcohol imagery on New Zealand (NZ) television, a content analysis of 98 hours of prime-time television programs and advertising was carried out over 7 consecutive days' viewing in June/July 2004. The main outcome measures were number of scenes in programs, trailers and advertisements depicting alcohol imagery; the extent of critical versus neutral and promotional imagery; and the mean number of scenes with alcohol per hour, and characte...

  16. Advanced Image Processing of Aerial Imagery

    Science.gov (United States)

    Woodell, Glenn; Jobson, Daniel J.; Rahman, Zia-ur; Hines, Glenn

    2006-01-01

    Aerial imagery of the Earth is an invaluable tool for the assessment of ground features, especially during times of disaster. Researchers at the NASA Langley Research Center have developed techniques which have proven to be useful for such imagery. Aerial imagery from various sources, including Langley's Boeing 757 Aries aircraft, has been studied extensively. This paper discusses these studies and demonstrates that better-than-observer imagery can be obtained even when visibility is severely compromised. A real-time, multi-spectral experimental system will be described and numerous examples will be shown.

  17. The Intersection of Imagery Ability, Imagery Use, and Learning Style: An Exploratory Study

    Science.gov (United States)

    Bolles, Gina; Chatfield, Steven J.

    2009-01-01

    This study explores the intersection of the individual's imagery ability, imagery use in dance training and performance, and learning style. Thirty-four intermediate-level ballet and modern dance students at the University of Oregon completed the Movement Imagery Questionnaire-Revised (MIQ-R) and Kolb's Learning Style Inventory-3 (LSI-3). The four…

  18. Value Adding Management

    DEFF Research Database (Denmark)

    Jensen, Per Anker; Katchamart, Akarapong

    2011-01-01

    Purpose: To investigate how Facilities Management (FM) can add value and develop a management concept that can assist facilities managers in implementing value adding strategies and practices. Theory: The study is based on the management model for FM included in the European FM standards, recent...... theories on added value of FM and real estate and the related concept of Value Management from building projects. The study is related to the EuroFM research group on The Added Value of FM. Design/methodology/approach: The study outlines a preliminary theoretical based management concept, which...... the relevance of the basic concept and provides an important example of how Value Adding Management can be implemented and added value measured. Originality/value: The study develops a concept of Value Adding Management, which is new in FM literature. It is expected to increase the awareness of the impacts...

  19. OrthoImagery Submission for Isabella county, MI

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This data set contains 1-meter resolution imagery derived from the 2005 National Agriculture Imagery Program (NAIP) statewide aerial imagery acquisition. Data have...

  20. AdS3: the NHEK generation

    Science.gov (United States)

    Bena, Iosif; Heurtier, Lucien; Puhm, Andrea

    2016-05-01

    It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.

  1. Twistor methods for AdS$_5$

    CERN Document Server

    Adamo, Tim; Williams, Jack

    2016-01-01

    We consider the application of twistor theory to five-dimensional anti-de Sitter space. The twistor space of AdS$_5$ is the same as the ambitwistor space of the four-dimensional conformal boundary; the geometry of this correspondence is reviewed for both the bulk and boundary. A Penrose transform allows us to describe free bulk fields, with or without mass, in terms of data on twistor space. Explicit representatives for the bulk-to-boundary propagators of scalars and spinors are constructed, along with twistor action functionals for the free theories. Evaluating these twistor actions on bulk-to-boundary propagators is shown to produce the correct two-point functions.

  2. Vividness of Object and Spatial Imagery.

    Science.gov (United States)

    Blazhenkova, Olesya

    2016-04-01

    Vividness is one of the fundamental characteristics of visual mental imagery. The first research goal was to examine whether vividness that refer to imagery of pictorial object (color, texture, or shape) versus spatial (three dimensional structure, location, or mechanism) properties constitute separate vividness dimensions. The second goal was to develop a vividness questionnaire separately assessing dimensions of imagery vividness. In Study 1, 111 students (M age = 21.8 years, SD = 1.3) evaluated the vividness of imagery evoked by nine object and nine spatial items from the pilot version of the new Vividness of Object and Spatial Imagery (VOSI) questionnaire, completed a self-report assessment of object and spatial imagery, and rated their aptitudes in art and science. Analysis indicated that imagery vividness comprised object and spatial dimensions. Object vividness items were positively associated with the self-report measure and ratings of artistic abilities, whereas spatial vividness items were positively associated with self-report measure and ratings of science abilities. In Study 2, an independent sample of 205 students (M age = 21 years, SD = 1.7) completed the second version of the VOSI, art and science aptitude ratings, and a number of self-report and performance measures assessing object and spatial imagery. Object and spatial imagery vividness items loaded on factors with 28 retained items; this two-factor vividness model fit the data better than a unidimensional vividness model. The questionnaire had satisfactory Cronbach's α for object vividness scale (.88) and for spatial vividness scale (.85). Correlational analyses supported convergent and discriminative validity of the VOSI. While object imagery vividness and spatial imagery vividness share some underlying vividness variance, they are dissociated into separate dimensions. PMID:27166329

  3. New Percepts via Mental Imagery?

    OpenAIRE

    Fred Walter Mast; Elisa eTartaglia; Michael eHerzog

    2012-01-01

    We are able to extract detailed information from mental images that we were not explicitly aware of during encoding. For example, we can discover a new figure when we rotate a previously seen image in our mind. However, such discoveries are not “really” new but just new “interpretations.” In two recent publications, we have shown that mental imagery can lead to perceptual learning (Tartaglia et al., 2009, 2012). Observers imagined the central line of a bisection stimulus for thousands of tria...

  4. Thematic mapping from satellite imagery

    CERN Document Server

    Denègre, J

    2013-01-01

    Thematic Mapping from Satellite Imagery: A Guidebook discusses methods in producing maps using satellite images. The book is comprised of five chapters; each chapter covers one stage of the process. Chapter 1 tackles the satellite remote sensing imaging and its cartographic significance. Chapter 2 discusses the production processes for extracting information from satellite data. The next chapter covers the methods for combining satellite-derived information with that obtained from conventional sources. Chapter 4 deals with design and semiology for cartographic representation, and Chapter 5 pre

  5. National Agriculture Imagery Program (NAIP) Digital Ortho Imagery for Bent's Old Fort National Historic Site Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — This data set contains imagery from the National Agriculture Imagery Program (NAIP). NAIP acquires digital ortho imagery during the agricultural growing seasons in...

  6. Motor Neuron Diseases

    Science.gov (United States)

    ... Awards Enhancing Diversity Find People About NINDS Motor Neuron Diseases Fact Sheet See a list of all ... can I get more information? What are motor neuron diseases? The motor neuron diseases (MNDs) are a ...

  7. Mental Imagery in Creative Problem Solving.

    Science.gov (United States)

    Polland, Mark J.

    In order to investigate the relationship between mental imagery and creative problem solving, a study of 44 separate accounts reporting mental imagery experiences associated with creative discoveries were examined. The data included 29 different scientists, among them Albert Einstein and Stephen Hawking, and 9 artists, musicians, and writers,…

  8. Imagery, Music, Cognitive Style and Memory.

    Science.gov (United States)

    Stratton, Valerie N.; Zalanowski, Annette

    Paired associate memory was tested with imagery and repetition instructions, with and without background music. Subjects were 64 students enrolled in an introductory psychology course. Music was found to have no effect with imagery instructions, but significantly improved performance with the repetition instructions. Music had different effects on…

  9. Alcohol imagery on New Zealand television

    Directory of Open Access Journals (Sweden)

    Reeder Anthony I

    2007-02-01

    Full Text Available Abstract Background To examine the extent and nature of alcohol imagery on New Zealand (NZ television, a content analysis of 98 hours of prime-time television programs and advertising was carried out over 7 consecutive days' viewing in June/July 2004. The main outcome measures were number of scenes in programs, trailers and advertisements depicting alcohol imagery; the extent of critical versus neutral and promotional imagery; and the mean number of scenes with alcohol per hour, and characteristics of scenes in which alcohol featured. Results There were 648 separate depictions of alcohol imagery across the week, with an average of one scene every nine minutes. Scenes depicting uncritical imagery outnumbered scenes showing possible adverse health consequences of drinking by 12 to 1. Conclusion The evidence points to a large amount of alcohol imagery incidental to storylines in programming on NZ television. Alcohol is also used in many advertisements to market non-alcohol goods and services. More attention needs to be paid to the extent of alcohol imagery on television from the industry, the government and public health practitioners. Health education with young people could raise critical awareness of the way alcohol imagery is presented on television.

  10. ADS National Programmes: India

    International Nuclear Information System (INIS)

    Initial preliminary studies in India on ADS concepts were aimed toward applications such as, one way coupled booster reactor concept, thorium burner concept, enhancement of breeding rate of thorium– fueled fast reactors, and to incinerate Pu and minor actinides discharged from heavy water and fast reactors. These studies led to a roadmap on development of ADS subsystems in India, which was chalked out initially in June 2001. It was realized in these studies that the most challenging subsystem in terms of technology development and capital investment for ADS in India would be the high intensity proton accelerator, and that it must be accomplished in phased manner. Of the two alternative accelerator types, viz. the cyclotron and linear accelerator (linac), it is concluded that only linac would provide the necessary intense beam current for ADS applications. The energy amplifier (EA) scheme, with lead (45.5%) bismuth (55.5%) eutectic (LBE) as target & coolant, which was proposed in the early nineties would be one of the desired configurations of ADS for Indian applications. Additionally, subcritical reactor core of Indian Advanced Heavy Water Reactor (AHWR), with advantages of its low fission power density, and neutron economy is also a candidate among various ADS reactor configurations. These options of ADS configurations for thorium utilization are based on the neutronic properties of 233U isotope as fissile fuel, which are more or less similar in thermal and in moderately fast neutron spectra

  11. Detection of mental imagery and attempted movements in patients with disorders of consciousness using EEG

    Directory of Open Access Journals (Sweden)

    Petar eHorki

    2014-12-01

    Full Text Available Further development of an EEG based communication device for patients with disorders of consciousness (DoC could benefit from addressing the following gaps in knowledge – first, an evaluation of different types of motor imagery; second, an evaluation of passive feet movement as a mean of an initial classifier setup; and third, rapid delivery of biased feedback. To that end we investigated whether complex and / or familiar mental imagery, passive, and attempted feet movement can be reliably detected in patients with DoC using EEG recordings, aiming to provide them with a means of communication. Six patients in a minimally conscious state (MCS took part in this study. The patients were verbally instructed to perform different mental imagery tasks (sport, navigation, as well as attempted feet movements, to induce distinctive event-related (desynchronization (ERD/S patterns in the EEG. Offline classification accuracies above chance level were reached in all three tasks (i.e. attempted feet, sport, and navigation, with motor tasks yielding significant (p<0.05 results more often than navigation (sport: 10 out of 18 sessions; attempted feet: 7 out of 14 sessions; navigation: 4 out of 12 sessions. The passive feet movements, evaluated in one patient, yielded mixed results: whereas time-frequency analysis revealed task-related EEG changes over neurophysiological plausible cortical areas, the classification results were not significant enough (p<0.05 to setup an initial classifier for the detection of attempted movements. Concluding, the results presented in this study are consistent with the current state of the art in similar studies, to which we contributed by comparing different types of mental tasks, notably complex motor imagery and attempted feet movements, within patients. Furthermore, we explored new venues, such as an evaluation of passive feet movement as a mean of an initial classifier setup, and rapid delivery of biased feedback.

  12. Mobile ad hoc networking

    CERN Document Server

    John Wiley & Sons

    2004-01-01

    "Assimilating the most up-to-date information on research and development activities in this rapidly growing area, Mobile Ad Hoc Networking covers physical, data link, network, and transport layers, as well as application, security, simulation, and power management issues in sensor, local area, personal, and mobile ad hoc networks. Each of the book's sixteen chapters has been written by a top expert and discusses in-depth the most important topics in the field. Mobile Ad Hoc Networking is an excellent reference and guide for professionals seeking an in-depth examination of topics that also provides a comprehensive overview of the current state-of-the-art."--Jacket.

  13. Coopetitive Ad Auctions

    OpenAIRE

    Hoy, Darrell; Jain, Kamal; Wilkens, Christopher A.

    2012-01-01

    A single advertisement often benefits many parties, for example, an ad for a Samsung laptop benefits Microsoft. We study this phenomenon in search advertising auctions and show that standard solutions, including the status quo ignorance of mutual benefit and a benefit-aware Vickrey-Clarke-Groves mechanism, perform poorly. In contrast, we show that an appropriate first-price auction has nice equilibria in a single-slot ad auction --- all equilibria that satisfy a natural cooperative envy-freen...

  14. AdS_3: the NHEK generation

    CERN Document Server

    Bena, Iosif; Puhm, Andrea

    2015-01-01

    It was argued in arXiv:1203.4227 that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically-AdS_3 x S^3/Z_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.

  15. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1992-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  16. THE ORTHOPAEDIC REHABILITATION OF BALANCE: AN EXPERIMENTAL STUDY ON THE ROLE OF MENTAL IMAGERY AND EMOTIONAL VARIABLES.

    Directory of Open Access Journals (Sweden)

    Santo F. Di Nuovo

    2015-05-01

    Full Text Available Mental Imagery (i.e., processing of objects’ properties and spatial relations, including the ability of mentally rotating and manipulating objects in the space, is relevant for movement and its development, and particularly for rehabilitation of motor skills. Few studies aimed at assessing  the efficacy of imagery training used objective scores of Mental Imagery skills, preferring self-evaluations of these abilities reported by the subjects themselves. The aim of the paper was to explore the relevance of Mental Imagery, assessed by objective tests, in predicting the improvement of balance skills, after a standard rehabilitative training in orthopaedic settings; taking into account also emotional variables as anxiety and depression. A controlled study was conducted assessing the changes in balance skills after rehabilitative training. The sample was composed of 30 orthopaedic inpatients (females 66.7%, age range 47-91 years. To measure the dependent variable for pre-post assessment, B-scale from Performance-oriented mobility assessment test (POMA was used. Independent variables were measured using Mental Imagery Test, Mini-Mental State Examination, Hamilton Depression Rating Scale and Hamilton Anxiety Rating Scales. The best predictor of improvement in balance after rehabilitation is the Mental Imagery test, followed by age and mental efficiency. Anxiety predicts negatively the improvement, while education and depression appear to influence less the rehabilitation process. In conclusion, the study demonstrates that mental imagery is relevant in helping balance rehabilitation. A training of this function could be essential for clinical practice; the trainers should assess preliminarily the subject's attitude and ability to use mental imagery, with the aim of optimizing the rehabilitative process.

  17. Mental practice promotes motor anticipation: evidence from skilled music performance.

    Science.gov (United States)

    Bernardi, Nicolò F; De Buglio, Matteo; Trimarchi, Pietro D; Chielli, Alfonso; Bricolo, Emanuela

    2013-01-01

    Mental practice (MP) has been shown to improve movement accuracy and velocity, but it is not known whether MP can also optimize movement timing. We addressed this question by studying two groups of expert pianists who performed challenging music sequences after either MP or physical practice (PP). Performance and motion-capture data were collected along with responses to imagery questionnaires. The results showed that MP produced performance improvements, although to a lower degree than PP did. MP and PP induced changes in both movement velocity and movement timing, promoting the emergence of movement anticipatory patterns. Furthermore, motor imagery was associated with greater changes in movement velocity, while auditory imagery was associated with greater movement anticipation. Data from a control group that was not allowed to practice confirmed that the changes in accuracy and kinematics were not due to mere repetition of the sequence during testing. This study provides the first evidence of an anticipatory control following MP and extends the present knowledge on the effectiveness of MP to a task of unparalleled motor complexity. The practical implications of MP in the motor domain are discussed. PMID:23970859

  18. Mental practice promotes motor anticipation: evidence from skilled music performance

    Directory of Open Access Journals (Sweden)

    Nicolò Francesco Bernardi

    2013-08-01

    Full Text Available Mental practice (MP has been shown to improve movement accuracy and velocity, but it is not known whether MP can also optimize movement timing. We addressed this question by studying two groups of expert pianists who performed challenging music sequences after either MP or physical practice (PP. Performance and motion-capture data were collected along with responses to imagery questionnaires. The results showed that MP produced performance improvements, although to a lower degree than PP did. MP and PP induced changes in both movement velocity and movement timing, promoting the emergence of movement anticipatory patterns. Furthermore, motor imagery was associated with greater changes in movement velocity, while auditory imagery was associated with greater movement anticipation. Data from a control group that was not allowed to practice confirmed that the changes in accuracy and kinematics were not due to mere repetition of the sequence during testing. This study provides the first evidence of an anticipatory control following MP and extends the present knowledge on the effectiveness of mental practice to a task of unparalleled motor complexity. The practical implications of MP in the motor domain are discussed.

  19. The Sport Imagery Questionnaire for Children (SIQ-C)

    Science.gov (United States)

    Hall, C. R.; Munroe-Chandler, K. J.; Fishburne, G. J.; Hall, N. D.

    2009-01-01

    Athletes of all ages report using imagery extensively to enhance their sport performance. The Sport Imagery Questionnaire (Hall, Mack, Paivio, & Hausenblas, 1998) was developed to assess cognitive and motivational imagery used by adult athletes. No such instrument currently exists to measure the use of imagery by young athletes. The aim of the…

  20. The SWOT analysis of Traditional Chinese Mind & Imagery Therapy

    OpenAIRE

    Ai-Dong JI; Shu-zhen Zheng; Chun-yan Liang; Ji-fei Yang

    2014-01-01

    Mind & Imagery Therapy breathign technique and clinical application is an important part of the inheritance and protection of traditional Chinese medicine, establish Mind & Imagery Therapy department can promote the inheritance and development. To explore the significance and urgency of the hospital building of Mind & Imagery Therapy department, using SWOT analysis method, the traditional Chinese building of Mind & Imagery Therapy department's strengths, weaknesses, opportunit...

  1. Motor Priming in Neurorehabilitation

    OpenAIRE

    Stoykov, Mary Ellen; Madhavan, Sangeetha

    2015-01-01

    Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few ...

  2. ADS National Programmes: Italy

    International Nuclear Information System (INIS)

    Following a preliminary design developed in 1998, based on the Energy Amplifier concept proposed by CERN, a first configuration of a lead-bismuth Eutectic cooled Experimental ADS (LBE-XADS) was worked out in the period 1999–2001, under the aegis of MURST, by a group of Italian organizations led by Ansado Nucleare, with the aim of assessing the feasibility of a small sized (80 MWth) ADS. At the end of 1997 a joint effort of ENEA (National Agency for New Technology, Energy and the Environment) and INFN (National Institute for Nuclear Physics) led to the approval of a national programme by MURST (Minister for University and Scientific and Technological Research) named TRASCO (TRAsmutazione SCOrie) aiming at the study of physics and technologies needed to design an ADS for radioactive waste transmutation. The programme consisted of research subprogrammes on accelerator, neutronics, thermalhydraulics analysis, beam window technology, and material technology and compatibility with Pb and Pb-Bi. At now, most of the activities in support to the ADS development carried out at national level are part of EU-funded Projects. These activities are complemented by the programme agreement (AdP -Accordo di programma), signed between ENEA and the Ministry of Economic Development, which provides in general a range of activities aimed at the development of sustainable nuclear fission systems. Several universities and the national industry are involved, besides ENEA, in the activities

  3. Attentional Demands on Motor-Respiratory Coordination

    Science.gov (United States)

    Hessler, Eric E.; Amazeen, Polemnia G.

    2009-01-01

    Athletic performance requires the pacing of breathing with exercise, known as motor-respiratory coordination (MRC). In this study, we added cognitive and physical constraints while participants intentionally controlled their breathing locations during rhythmic arm movement. This is the first study to examine a cognitive constraint on MRC.…

  4. ADS National Programmes: China

    International Nuclear Information System (INIS)

    In China the conceptual study of an ADS concept which lasted for about five years ended in 1999. As one project of the National Basic Research Programme of China (973 Programme) in energy domain, which is sponsored by the China Ministry of Science and Technology (MOST), a five year programme of fundamental research of ADS physics and related technology was launched in 2000 and passed national review at the end of 2005. From 2007, another five year 973 Programme Key Technology Research of Accelerator Driven Subcritical System for Nuclear waste Transmutation started. The research activities were focused on HPPA physics and technology, reactor physics of external source driven subcritical assembly, nuclear data base and material study. For HPPA, a high current injector consisting of an ECR ion source, LEBT and an RFQ accelerating structure of 3.5 MeV has been built and were being improved. In reactor physics study, a series of neutron multiplication experimental study has been carrying out. The VENUS I facility has been constructed as the basic experimental platform for neutronics study in ADS blanket. VENUS I a zero power subcritical neutron multiplying assembly driven by external neutron produced by a pulsed neutron generator or 252Cf neutron source. The theoretical, experimental and simulation studies on nuclear data, material properties and nuclear fuel circulation related to ADS are carried out in order to provide the database for ADS system analysis. China Institute of Atomic Energy (CIAE), Institute of High Energy Physics (IHEP) and other Chinese institutes carried out the MOST project together. Besides CIAE, China Academy of Science (CAS) pays more and more attention to Advanced Nuclear Fuel Cycles (ANFC). A large programme of ANFC, including ADS and Th based nuclear fuel cycle, has been launched by CAS

  5. Wave directional spectrum from SAR imagery

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A.; Sarma, Y.V.B.; Menon, H.B.; Vethamony, P.

    wave like features, the latter appearing to be of "white noise" nature. There exists a 180 degrees ambiguity in wave direction observed from radar imageries. Based on the method of Atanassov et al (1985), a computer program has been developed...

  6. Technical parameters for specifying imagery requirements

    Science.gov (United States)

    Coan, Paul P.; Dunnette, Sheri J.

    1994-01-01

    Providing visual information acquired from remote events to various operators, researchers, and practitioners has become progressively more important as the application of special skills in alien or hazardous situations increases. To provide an understanding of the technical parameters required to specify imagery, we have identified, defined, and discussed seven salient characteristics of images: spatial resolution, linearity, luminance resolution, spectral discrimination, temporal discrimination, edge definition, and signal-to-noise ratio. We then describe a generalizing imaging system and identified how various parts of the system affect the image data. To emphasize the different applications of imagery, we have constrasted the common television system with the significant parameters of a televisual imaging system for technical applications. Finally, we have established a method by which the required visual information can be specified by describing certain technical parameters which are directly related to the information content of the imagery. This method requires the user to complete a form listing all pertinent data requirements for the imagery.

  7. Dynamic ad hoc networks

    CERN Document Server

    Rashvand, Habib

    2013-01-01

    Motivated by the exciting new application paradigm of using amalgamated technologies of the Internet and wireless, the next generation communication networks (also called 'ubiquitous', 'complex' and 'unstructured' networking) are changing the way we develop and apply our future systems and services at home and on local, national and global scales. Whatever the interconnection - a WiMAX enabled networked mobile vehicle, MEMS or nanotechnology enabled distributed sensor systems, Vehicular Ad hoc Networking (VANET) or Mobile Ad hoc Networking (MANET) - all can be classified under new networking s

  8. Eating ad Libitum

    DEFF Research Database (Denmark)

    Hillersdal, Line

    in the context of the 'ad libitum meal'. The analytical interest is thus what kind of eaters and bodies are enacted in the meal test and what ideas of prevention and treatment are embedded in their standards. Drawing from ongoing empirical work among Danish obesity researchers performing scientific meal tests I...... ask what make up food stuff and eaters in the meal tests? More specifically I explore a scientific testing of changes in taste preferences before and after weight-loss surgery using an ad libitum buffet with a selection of different foods and another testing the effect of exercise on appetite also...

  9. Surface modelling for 2D imagery

    OpenAIRE

    Lieng, Henrik

    2014-01-01

    Vector graphics provides powerful tools for drawing scalable 2D imagery. With the rise of mobile computers, of different types of displays and image resolutions, vector graphics is receiving an increasing amount of attention. However, vector graphics is not the leading framework for creating and manipulating 2D imagery. The reason for this reluctance of employing vector graphical frameworks is that it is difficult to handle complex behaviour of colour across the 2D domain. ...

  10. Guided Imagery and Music - And Beyond?

    DEFF Research Database (Denmark)

    Bonde, Lars Ole

    4 original research articles, one essay, a classical article and two clinical papers documenting the development of theory, research and clinical practice within the receptive music therapy model [The Bonny Method of] Guided Imagery and Music.......4 original research articles, one essay, a classical article and two clinical papers documenting the development of theory, research and clinical practice within the receptive music therapy model [The Bonny Method of] Guided Imagery and Music....

  11. Spontaneous ocular positioning during visual imagery in patients with hemianopia and/or hemineglect.

    Science.gov (United States)

    Fourtassi, Maryam; Rode, Gilles; Tilikete, Caroline; Pisella, Laure

    2016-06-01

    Spontaneous eye movements during imagery are not random and can be used to study and reveal mental visualization processes (Fourtassi et al., 2013; Johansson et al. 2006). For example, we previously showed that during memory recall of French towns via imagery healthy individuals looks straight ahead when recalling Paris and their subsequent gaze positions are significantly correlated with the real GPS coordinates of the recalled towns. This correlation suggests that memory retrieval is done via depictive representations as it is never found when the towns are recalled using verbal fluency. In the present paper we added to this finding by showing that the mental image is spontaneously centered on the head or body midline. In order to investigate the capacities of visual imagery in patients, and by extension, the role of primary visual cortex and fronto-parietal cortex in spatial visual imagery, we recorded gaze positions during memory recall of French towns in an imagery task, a non-imagery task (verbal fluency), and a visually-guided task in five patients with left or right hemianopia and in four patients with hemineglect (two with left hemianopia and two without). The correlation between gaze position and real GPS coordinates of the recalled towns was significant in all hemianopic patients, but in patients with hemineglect this was only the case for towns located on the right half of the map of France. This suggests hemianopic patients can perform spatially consistent mental imagery despite direct or indirect unilateral lesions of the primary visual cortex. In contrast, the left-sided towns recalled by hemineglect patients, revealed that they have some spatial inconsistency or representational difficulty. Hemianopic patients positioned and maintained their gaze in their contralesional hemispace, suggesting that their mental map was not centered on their head or body midline. This contralesional gaze positioning appeared to be a general compensation strategy and

  12. Spontaneous ocular positioning during visual imagery in patients with hemianopia and/or hemineglect.

    Science.gov (United States)

    Fourtassi, Maryam; Rode, Gilles; Tilikete, Caroline; Pisella, Laure

    2016-06-01

    Spontaneous eye movements during imagery are not random and can be used to study and reveal mental visualization processes (Fourtassi et al., 2013; Johansson et al. 2006). For example, we previously showed that during memory recall of French towns via imagery healthy individuals looks straight ahead when recalling Paris and their subsequent gaze positions are significantly correlated with the real GPS coordinates of the recalled towns. This correlation suggests that memory retrieval is done via depictive representations as it is never found when the towns are recalled using verbal fluency. In the present paper we added to this finding by showing that the mental image is spontaneously centered on the head or body midline. In order to investigate the capacities of visual imagery in patients, and by extension, the role of primary visual cortex and fronto-parietal cortex in spatial visual imagery, we recorded gaze positions during memory recall of French towns in an imagery task, a non-imagery task (verbal fluency), and a visually-guided task in five patients with left or right hemianopia and in four patients with hemineglect (two with left hemianopia and two without). The correlation between gaze position and real GPS coordinates of the recalled towns was significant in all hemianopic patients, but in patients with hemineglect this was only the case for towns located on the right half of the map of France. This suggests hemianopic patients can perform spatially consistent mental imagery despite direct or indirect unilateral lesions of the primary visual cortex. In contrast, the left-sided towns recalled by hemineglect patients, revealed that they have some spatial inconsistency or representational difficulty. Hemianopic patients positioned and maintained their gaze in their contralesional hemispace, suggesting that their mental map was not centered on their head or body midline. This contralesional gaze positioning appeared to be a general compensation strategy and

  13. NASA's Global Imagery Management System: TIE

    Science.gov (United States)

    Alarcon, C.; Roberts, J. T.; Huang, T.; Thompson, C. K.; Cechini, M. F.; Hall, J. R.; Murphy, K. J.

    2014-12-01

    NASA's Earth Observing System Data and Information System (EOSDIS)' Global Imagery Browse Services (GIBS) is a system that provides full resolution imagery from a broad set of Earth science disciplines to the public. Using well-accepted standard protocols such as the Open Geospatial Consortium (OGC) Web Map Tile Service (WMTS), GIBS delivers global imagery efficiently and responsively. Behind this service, lies The Imagery Exchange (TIE), a workflow data management solution developed at the Jet Propulsion Laboratory. TIE is an Open Archival Information System responsible for orchestrating the workflow for acquisition, preparation, generation, and archiving of imagery to be served by the GIBS' web mapping tile service, OnEarth. The workflow collects imagery provenance throughout a product's lifecycle by leveraging the EOS Clearing House (ECHO) and other long-term metadata repositories in order to promote reproducibility. Through this focus on metadata, TIE provides spatial and temporal searching capabilities such as an OpenSearch interface as well as facilitating the generation of metadata standards such as the OGC GetCapabilities. Designed as a scalable system, TIE's subsystems can scale-up or scale-down depending on the data volume it handles through the usage of popular open source technologies such as Apache Zookeeper and Grails. This presentation will cover the challenges and solutions to developing such a horizontally scalable data management system where science products are often varied with disparate provenance pertaining to source platforms and instruments, spatial resolutions, processing algorithms, metadata models and packaging specifications.

  14. ADS National Programmes: Belgium

    International Nuclear Information System (INIS)

    The Belgian activities in the field of Accelerator Driven Systems (ADS) are mainly related to the MYRRHA project development. MYRRHA is an accelerator driven, multi purpose fast neutron spectrum facility for R&D, cooled by a lead-bismuth eutectic. SCK•CEN has started the MYRRHA project as a national programme with several national & international bilateral collaboration agreements; the project has now evolved as an European integrated project in the frame of the IPEUROTRANS (European Commission, Sixth Framework Programme). The MYRRHA ‘Draft-2’ predesign file (completed in the early 2005) has been proposed to the partners as a basis for the XT-ADS machine. After a detailed investigation of potential alternatives, the MYRRHA concept (for the subcritical core, the primary coolant system, the accommodation of experimental rigs, the reactor vessel and the spallation target) has been kept with some modifications to achieve the XT-ADS objectives. The most recent version of the XT-ADS design was presented in the 2007 TWG meeting

  15. D-branes in Lorentzian AdS(3)

    CERN Document Server

    Israel, D

    2005-01-01

    We study the exact construction of D-branes in Lorentzian AdS(3). We start by defining a family of conformal field theories that gives a natural Euclidean version of the SL(2,R) CFT and does not correspond to H(3)+, the analytic continuation of AdS(3). We argue that one can recuperate the exact CFT results of Lorentzian AdS(3), upon an analytic continuation in the moduli space of these conformal field theories. Then we construct exact boundary states for various symmetric and symmetry-breaking D-branes in AdS(3).

  16. Localization on $AdS_2\\times S^1$

    CERN Document Server

    David, Justin R; Gupta, Rajesh Kumar; Narain, Kumar

    2016-01-01

    Conformal symmetry relates the metric on $AdS_2 \\times S^{1}$ to that of $S^3$. This implies that under a suitable choice of boundary conditions for fields on $AdS_2$ the partition function of conformal field theories on these spaces must agree which makes $AdS_2 \\times S^{1}$ a good testing ground to study localization on non-compact spaces. We study supersymmetry on $AdS_2\\times S^1$ and determine the localizing Lagrangian for ${\\cal N}=2$ supersymmetric Chern-Simons theory on $AdS_2\\times S^1$. We evaluate the partition function of ${\\cal N}=2$ supersymmetric Chern-Simons theory on $AdS_2 \\times S^1$ using localization, where the radius of $S^1$ is $q$ times that of $AdS_2$. With boundary conditions on $AdS_2\\times S^1$ which ensure that all the physical fields are normalizable and lie in the space of square integrable wave functions in $AdS_2$, the result for the partition function precisely agrees with that of the theory on the $q$-fold covering of $S^3$.

  17. Electric motor handbook

    CERN Document Server

    Chalmers, B J

    2013-01-01

    Electric Motor Handbook aims to give practical knowledge in a wide range of capacities such as plant design, equipment specification, commissioning, operation and maintenance. The book covers topics such as the modeling of steady-state motor performance; polyphase induction, synchronous, and a.c. commutator motors; ambient conditions, enclosures, cooling and loss dissipation; and electrical supply systems and motor drives. Also covered are topics such as variable-speed drives and motor control; materials and motor components; insulation types, systems, and techniques; and the installation, sit

  18. Directed flux motor

    Science.gov (United States)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

  19. Processing Color in Astronomical Imagery

    CERN Document Server

    Arcand, Kimberly K; Rector, Travis; Levay, Zoltan G; DePasquale, Joseph; Smarr, Olivia

    2013-01-01

    Every year, hundreds of images from telescopes on the ground and in space are released to the public, making their way into popular culture through everything from computer screens to postage stamps. These images span the entire electromagnetic spectrum from radio waves to infrared light to X-rays and gamma rays, a majority of which is undetectable to the human eye without technology. Once these data are collected, one or more specialists must process the data to create an image. Therefore, the creation of astronomical imagery involves a series of choices. How do these choices affect the comprehension of the science behind the images? What is the best way to represent data to a non-expert? Should these choices be based on aesthetics, scientific veracity, or is it possible to satisfy both? This paper reviews just one choice out of the many made by astronomical image processors: color. The choice of color is one of the most fundamental when creating an image taken with modern telescopes. We briefly explore the ...

  20. Cognitive aesthetics of alchemical imagery.

    Science.gov (United States)

    Connolly, Angela M

    2013-02-01

    Jung's contribution to the understanding of the relevance of psychology to alchemy has become increasingly invalidated by the ahistorical nature of his approach, just as his tendency to ignore the importance of cognitive aesthetics for an improved comprehension of the functions of alchemical images has prevented Jungians from further extending Jung's insight of the importance of alchemy for psychology. This paper explores the history of the development of alchemical illustrations in Western Europe from the 14(th) to the 16(th) century, tracing the emergent processes over time. It is only when we take into consideration the historical dimension and the aesthetics of alchemical imagery that it becomes possible to demonstrate how the increasing use of certain aesthetic techniques such as the disjunction and recombination of separate metaphorical elements of previous illustrations, the use of compressive combinations and the use of framing devices worked to gradually increase the cognitive function and the symbolical power of the images. If alchemy is still relevant to psychotherapy it is exactly because it helps us to understand the importance of cognitive aesthetics in our approach to the images, metaphors and narratives of our patients.

  1. Cognitive aesthetics of alchemical imagery.

    Science.gov (United States)

    Connolly, Angela M

    2013-02-01

    Jung's contribution to the understanding of the relevance of psychology to alchemy has become increasingly invalidated by the ahistorical nature of his approach, just as his tendency to ignore the importance of cognitive aesthetics for an improved comprehension of the functions of alchemical images has prevented Jungians from further extending Jung's insight of the importance of alchemy for psychology. This paper explores the history of the development of alchemical illustrations in Western Europe from the 14(th) to the 16(th) century, tracing the emergent processes over time. It is only when we take into consideration the historical dimension and the aesthetics of alchemical imagery that it becomes possible to demonstrate how the increasing use of certain aesthetic techniques such as the disjunction and recombination of separate metaphorical elements of previous illustrations, the use of compressive combinations and the use of framing devices worked to gradually increase the cognitive function and the symbolical power of the images. If alchemy is still relevant to psychotherapy it is exactly because it helps us to understand the importance of cognitive aesthetics in our approach to the images, metaphors and narratives of our patients. PMID:23350996

  2. Global Imagery in Online Advertisements

    Science.gov (United States)

    Hynes, Geraldine E.; Janson, Marius

    2007-01-01

    A well-designed online advertisement is essential for effective communication with potential customers and contributes to successful e-commerce. However, creating online sales messages that appeal to a broad range of cultures can pose unique challenges. Internet ads must offer both a globally appealing and a culture-specific message that in turn…

  3. Efeito das terapias associadas de imagem motora e de movimento induzido por restrição na hemiparesia crônica: estudo de caso Effects of associated therapies of motor imagery and constraint-induced movement in chronic hemiparesis: a case study

    OpenAIRE

    Claudia Morais Trevisan; Vanessa Trintinaglia

    2010-01-01

    Este estudo analisa os efeitos da associação das terapias de imagem motora e de movimento induzido por restrição na reeducação funcional do membro superior (MS) de um paciente com deficit sensorial e motor determinado por acidente vascular encefálico (AVE). A terapia de imagem motora (IM) consistiu em: 1o, estimulo visual do espelho, em 3 sessões semanais de 30 a 60 minutos por 4 semanas; e 2o, IM com prática mental, em 3 sessões semanais de 15 minutos por 3 semanas. Por último foi aplicada a...

  4. Handbook on linear motor application

    International Nuclear Information System (INIS)

    This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

  5. EOS-WEBSTER - Providing Satellite Imagery for Everyone

    Science.gov (United States)

    Schloss, A. L.; Moore, B.; Braswell, R.; Hurtt, G.; Armstrong, W.; Blaha, D.; Carmell, T.; Freuder, R.; Routhier, M.; Spencer, S.

    2002-12-01

    The University of New Hampshire's WEB-based System for Terrestrial Ecosystem Research (EOS-WEBSTER) distributes a special collection of data and imagery products for the Earth Science community. This collection includes satellite imagery from several sensors including the MODIS instrument aboard TERRA. Our services have been designed so that different types of users can access and use only the data that they want. Users can search EOS-WEBSTER's collections, create spatial and temporal subsets, and order data in ASCII or binary formats. We have developed a suite of MODIS products covering Amazonia. These products serve the Large Scale Biosphere-Atmosphere Project in Amazonia (LBA), a joint project of the Brazilian government and NASA. Products include 8-day reflectances (MOD09A1), daily fire potential (MOD14A1), and 16-day NDVIs (MOD13Q1), starting in January 2001. EOS-WEBSTER takes care of obtaining the 14 MODIS tiles that cover Amazonia and stitching them together into a seamless regional coverage. Users can cookie-cut the regional data into smaller areas of interest, such as a field site, a political boundary, or a watershed, then choose an output format such as GrADS and retrieve their order by ftp or on CD-ROM. EOS-WEBSTER delivers MODIS to users whether or not they can manipulate the HDF-EOS format. These regional data sets were developed in cooperation with Eros Data Center to facilitate use of MODIS products by the LBA community. Other products and regions can be developed for other user communities if there is enough interest. Please contact us at support@eos-webster.sr.unh.edu for more information. MODIS is only one of a variety of imagery products available from EOS-WEBSTER. Other platforms include Landsat, SPOT-VEGETATION and IKONOS. We provide Landsat imagery data access to educators by supporting the Forest Watch program, an educational project that includes K-12 teachers and students in UNH research activities that assess the state-of-health of local

  6. Management job ads

    DEFF Research Database (Denmark)

    Holmgreen, Lise-Lotte

    2014-01-01

    The article asks whether it is not the responsibility of corporations to address the issue of women being underrepresented in Danish management jobs. In other words, it is argued that corporations should be encouraged to engage more actively in the recruitment of both men and women for management...... jobs by discursively constructing job ads that appeal to both sexes. This argument is part of the broader field of corporate social responsibility, corporate citizenship, and stakeholder management, which involves discussions of the obligations of corporations to acknowledge and mitigate...... the increasingly widespread impact that their activities have on communities and social structures. The article emphasises the need for more active engagement on the part of corporations by analysing the discursive construction of preferred candidates in a small sample of Danish management job ads. By means...

  7. Design of BLDCM Driving and Control System for Motorized Treadmill

    Institute of Scientific and Technical Information of China (English)

    Qi Zhang; Hui Li; Li-Bin Wang

    2007-01-01

    To satisfy the requirement of developing a new generation of motorized treadmill for a famous domestic manufacturer, a brushless DC motor (BLDCM) driving and control system for motorized treadmill is developed. High integration and reliability of this system are ensured under the condition that intelligent power module (TPM) is used and the protection module is included. Periodic current control method is applied to reduce the average current flowing through the armature winding of the motor when the treadmill is required to start with low speed while large load is added. Piecewise proportion-integration-differentiation (PID) control algorithm is applied to solve the problem of speed fluctuation when impulse load is added. The motorized treadmill of a new generation with the driving and control system has the advantages of high reliability, good speed stability, wide timing scope, low cost, and long life-span. And it is very promising for practical applications.

  8. ADS National Programmes: France

    International Nuclear Information System (INIS)

    Studies related to nuclear reactors and radioactive waste started at the French National Centre for Scientific research, CNRS, as a result of the French law on radioactive waste that was published in 1991. They were initially organized around the programme PACE (Physique pour l’Aval du Cycle Electronucléaire = physics of the back end of the nuclear fuel cycle), which became PACEN (Physique pour l’Aval du Cycle et production d’Energie Nucléaire = Physics of the back end of the nuclear fuel cycle and production of nuclear energy) in 2006. Research on accelerator driven systems was from the beginning part of this programme. This research is mainly funded by the National Institute for Nuclear end Particle Physics (IN2P3) of CNRS and within the EURATOM European programmes (FP5, 6 and 7). The programme took place in several stages, and covered various scientific fields, benefitting from expertise of CNRS in the field. More specifically, it aimed and still aims to: – Test and verify the feasibility and design of the ADS concept, in terms of neutronics, physics of materials, design of the accelerator and tests of its prototypical components that have been built (or are at present under construction); – Measure and-or improve nuclear data related to radioactive waste transmutation. Today, most of the activities in support to ADS development carried out by CNRS focus on accelerator developments, GUINEVERE (Generator of Uninterrupted Intense NEutron at the lead VEnus REactor) experiment, ADS core studies, deployment scenarios and nuclear data measurements. The CEA R&D programmes on ADS are mainly focused on the European project EUROTRANS of the 6th Framework programme (2005–2010) and continued in the FREYA project of the 7th Framework Programme

  9. Adding linear orders

    CERN Document Server

    Shelah, Saharon

    2011-01-01

    We address the following question: Can we expand an NIP theory by adding a linear order such that the expansion is still NIP? Easily, if acl(A)=A for all A, then this is true. Otherwise, we give counterexamples. More precisely, there is a totally categorical theory for which every expansion by a linear order has IP. There is also an \\omega-stable NDOP theory for which every expansion by a linear order interprets bounded arithmetic.

  10. Computer Imagery and Neurological Rehabilitation: On the Use of Augmented Reality in Sensorimotor Training to Step Up Naturally Occurring Cortical Reorganization in Patients Following Stroke.

    Science.gov (United States)

    Correa-Agudelo, Esteban; Ferrin, Carlos; Velez, Paulo; Gomez, Juan D

    2016-01-01

    This work promotes the use of computer-generated imagery -as visual illusions- to speed up motor learning in rehabilitation. In support of this, we adhere the principles of experience-dependent neuroplasticity and the positive impact of virtual reality (VR) thereof. Specifically, post-stroke patients will undergo motor therapy with a surrogate virtual limb that fakes the paralyzed limb. Along these lines, their motor intentions will match the visual evidence, which fosters physiological, functional and structural changes over time, for recovery of lost function in an injured brain. How we make up such an illusion using computer graphics, is central to this paper. PMID:27046556

  11. Chronic motor tic disorder

    Science.gov (United States)

    Chronic vocal tic disorder; Tic - chronic motor tic disorder ... Chronic motor tic disorder is more common than Tourette syndrome . Chronic tics may be forms of Tourette syndrome. Tics usually start ...

  12. Fine motor control

    Science.gov (United States)

    ... figure out the child's developmental age. Children develop fine motor skills over time, by practicing and being taught. To have fine motor control, children need: Awareness and planning Coordination ...

  13. Neurocognitive evidence for mental imagery-driven hypoalgesic and hyperalgesic pain regulation.

    Science.gov (United States)

    Fardo, Francesca; Allen, Micah; Jegindø, Else-Marie Elmholdt; Angrilli, Alessandro; Roepstorff, Andreas

    2015-10-15

    Mental imagery has the potential to influence perception by directly altering sensory, cognitive, and affective brain activity associated with imagined content. While it is well established that mental imagery can both exacerbate and alleviate acute and chronic pain, it is currently unknown how imagery mechanisms regulate pain perception. For example, studies to date have been unable to determine whether imagery effects depend upon a general redirection of attention away from pain or focused attentional mechanisms. To address these issues, we recorded subjective, behavioral and ERP responses using 64-channel EEG while healthy human participants applied a mental imagery strategy to decrease or increase pain sensations. When imagining a glove covering the forearm, participants reported decreased perceived intensity and unpleasantness, classified fewer high-intensity stimuli as painful, and showed a more conservative response bias. In contrast, when imagining a lesion on the forearm, participants reported increased pain intensity and unpleasantness, classified more low-intensity stimuli as painful, and displayed a more liberal response bias. Using a mass-univariate approach, we further showed differential modulation of the N2 potentials across conditions, with inhibition and facilitation respectively increasing and decreasing N2 amplitudes between 122 and 180 ms. Within this time window, source localization associated inhibiting vs. facilitating pain with neural activity in cortical regions involved in cognitive inhibitory control and in the retrieval of semantic information (i.e., right inferior frontal and temporal regions). In contrast, the main sources of neural activity associated with facilitating vs. inhibiting pain were identified in cortical regions typically implicated in salience processing and emotion regulation (i.e., left insular, inferior-middle frontal, supplementary motor and precentral regions). Overall, these findings suggest that the content of a

  14. AdS 3-manifolds and Higgs bundles

    DEFF Research Database (Denmark)

    Alessandrini, Daniele; Li, Qiongling

    2015-01-01

    In this paper we investigate the relationships between closed AdS 3-manifolds and Higgs bundles. We have a new way to construct AdS structures that allows us to see many of their properties explicitly, for example we can recover the very recent formula by Tholozan for the volumes. We also find...

  15. Edinburgh Motor Assessment (EMAS)

    OpenAIRE

    Bak, Thomas

    2013-01-01

    Edinburgh Motor Assessment (EMAS) is a brief motor screening test, specifically designed for assessment of patients with dementia, aphasia and other cognitive disorders. It focuses, therefore, on those motor symptoms, which are known to occur in association with these diseases, such as extrapyramidal, amyotrophic, and cerebellar features as well as complex cognitive‐motor phenomena such as apraxia. EMAS has been developed by a team of neurologists and psychiatrists at the ...

  16. CONSOLIDATION OF MOTOR MEMORY

    OpenAIRE

    Krakauer, John W.; Shadmehr, Reza

    2005-01-01

    A question of great recent interest is whether motor memory consolidates in a manner analogous to declarative memories, with the formation of a memory that progresses over time from a fragile state, susceptible to interference by a lesion or a conflicting motor task, to a stabilized state, resistant to such interference. Here, we first review studies that examine the anatomical basis for motor consolidation: evidence implicates cerebellar circuitry for two types of associative motor learning,...

  17. An Examination of Movement Kinematics in Young People with High-functioning Autism and Asperger's Disorder: Further Evidence for a Motor Planning Deficit

    OpenAIRE

    Rinehart, Nicole J.; Bellgrove, Mark A.; Tonge, Bruce J.; Brereton, Avril V.; Howells-Rankin, Debra; Bradshaw, John L.

    2006-01-01

    This paper examines upper-body movement kinematics in individuals with high-functioning autism (HFA) and Asperger's disorder (AD). In general, the results indicate that HFA is more consistently associated with impaired motoric preparation/initiation than AD. The data further suggest that this quantitative difference in motor impairment is not necessarily underpinned by greater executive dysfunction vulnerability in autism relative to AD. Quantitative motoric dissociation between autism and AD...

  18. Evaporation of large black holes in AdS

    International Nuclear Information System (INIS)

    The AdS/CFT correspondence offers a new perspective on the long-standing black hole information paradox. However, to be able to use the available gauge/gravity machinery one is forced to consider so-called 'large' black holes in AdS, and these objects are thermodynamically stable - they do not evaporate. We describe a simple toy model that allows large AdS black holes to decay, by coupling the emitted radiation to an external scalar field propagating in an auxiliary space. This effectively changes the properties of the boundary of AdS, making it partly absorbing. We demonstrate that the evaporation process never ceases by explicitly presenting (a) the transmission coefficient for a wave scattering from the bulk into auxiliary space and (b) the greybody factor for a black 3-brane in an AdS background. Therefore, the model provides an interesting framework to address the information paradox using AdS/CFT techniques.

  19. Motor Neurons that Multitask

    OpenAIRE

    Goulding, Martyn

    2012-01-01

    Animals use a form of sensory feedback termed proprioception to monitor their body position and modify the motor programs that control movement. In this issue of Neuron, Wen et al. (2012) provide evidence that a subset of motor neurons function as proprioceptors in C. elegans, where B-type motor neurons sense body curvature to control the bending movements that drive forward locomotion.

  20. Quantum motor and future

    CERN Document Server

    Fateev, Evgeny G

    2013-01-01

    In a popular language, the possibilities of the Casimir expulsion effect are presented, which can be the basis of quantum motors. Such motors can be in the form of a special multilayer thin film with periodic and complex nanosized structures. Quantum motors of the type of the Casimir platforms can be the base of transportation, energy and many other systems in the future.

  1. Satellite imagery in a nuclear age

    International Nuclear Information System (INIS)

    Increasingly, high resolution satellite imaging systems are becoming available from multiple and diverse sources with capabilities useful for answering security questions. With increased supply, data availability and data authenticity may be assured. In a commercial market a supplier can ill afford the loss in market share that would result from any falsification of data. Similarly rising competitors willing to sell imagery of national security sites will decrease the tendency to endure self-imposed restrictions on sales of those sites. International organizations operating in the security interests of all nations might also gain preferential access. Costa for imagery will also fall to the point were individuals can afford purchases of satellite images. International organizations will find utility in exploiting imagery for solving international security problems. Housed within international organizations possessing competent staff, procedures, and 'shared destiny' stakes in resolving compliance discrepancies, the use of satellite imagery may provide a degree of stability in a world in which individuals, non-governmental organizations and governments may choose to exploit the available information for political gain. The use of satellite imagery outside these international organizations might not necessarily be aimed at seeking mutually beneficial solutions for international problems

  2. Imagery in Dance: A Literature Review.

    Science.gov (United States)

    Pavlik, Katherine; Nordin-Bates, Sanna

    2016-01-01

    Dance imagery is a consciously created mental representation of an experience, either real or imaginary, that may affect the dancer and her or his movement. In this study, imagery research in dance was reviewed in order to: 1. describe the themes and ideas that the current literature has attempted to illuminate and 2. discover the extent to which this literature fits the Revised Applied Model of Deliberate Imagery Use. A systematic search was performed, and 43 articles from 24 journals were found to fit the inclusion criteria. The articles were reviewed, analyzed, and categorized. The findings from the articles were then reported using the Revised Applied Model as a framework. Detailed descriptions of Who, What, When and Where, Why, How, and Imagery Ability were provided, along with comparisons to the field of sports imagery. Limitations within the field, such as the use of non-dance-specific and study-specific measurements, make comparisons and clear conclusions difficult to formulate. Future research can address these problems through the creation of dance-specific measurements, higher participant rates, and consistent methodologies between studies. PMID:27245944

  3. The musician's brain: functional imaging of amateurs and professionals during performance and imagery.

    Science.gov (United States)

    Lotze, M; Scheler, G; Tan, H-R M; Braun, C; Birbaumer, N

    2003-11-01

    We compared activation maps of professional and amateur violinists during actual and imagined performance of Mozart's violin concerto in G major (KV216). Execution and imagination of (left hand) fingering movements of the first 16 bars of the concerto were performed. Electromyography (EMG) feedback was used during imagery training to avoid actual movement execution and EMG recording was employed during the scanning of both executed and imagined musical performances. We observed that professional musicians generated higher EMG amplitudes during movement execution and showed focused cerebral activations in the contralateral primary sensorimotor cortex, the bilateral superior parietal lobes, and the ipsilateral anterior cerebellar hemisphere. The finding that professionals exhibited higher activity of the right primary auditory cortex during execution may reflect an increased strength of audio-motor associative connectivity. It appears that during execution of musical sequences in professionals, a higher economy of motor areas frees resources for increased connectivity between the finger sequences and auditory as well as somatosensory loops, which may account for the superior musical performance. Professionals also demonstrated more focused activation patterns during imagined musical performance. However, the auditory-motor loop was not involved during imagined performances in either musician group. It seems that the motor and auditory systems are coactivated as a consequence of musical training but only if one system (motor or auditory) becomes activated by actual movement execution or live musical auditory stimuli.

  4. Coulomb Friction Driving Brownian Motors

    International Nuclear Information System (INIS)

    We review a family of models recently introduced to describe Brownian motors under the influence of Coulomb friction, or more general non-linear friction laws. It is known that, if the heat bath is modeled as the usual Langevin equation (linear viscosity plus white noise), additional non-linear friction forces are not sufficient to break detailed balance, i.e. cannot produce a motor effect. We discuss two possibile mechanisms to elude this problem. A first possibility, exploited in several models inspired to recent experiments, is to replace the heat bath's white noise by a “collisional noise”, that is the effect of random collisions with an external equilibrium gas of particles. A second possibility is enlarging the phase space, e.g. by adding an external potential which couples velocity to position, as in a Klein—Kramers equation. In both cases, non-linear friction becomes sufficient to achieve a non-equilibrium steady state and, in the presence of an even small spatial asymmetry, a motor effect is produced. (general)

  5. The effect of Ad

    Institute of Scientific and Technical Information of China (English)

    李小艳

    2010-01-01

    There is the trend that now people appreciate those who are slim and regard slim even thin people beautiful. The thinner a person is, the more beautiful. Women, born to pursuit beauty, try various means to follow the trend. We all watch TV, and find a lot of advertisements on diet. The effect of them is tremendous. We all know the fact that it is not at all the better mouse trap will catch mouse. The sales methods are more important. If an advertisement is very interesting and seemingly effective, people will be lured by the ad and then try some of the products.

  6. Solid propellant motor

    Science.gov (United States)

    Shafer, J. I.; Marsh, H. E., Jr. (Inventor)

    1978-01-01

    A case bonded end burning solid propellant rocket motor is described. A propellant with sufficiently low modulus to avoid chamber buckling on cooling from cure and sufficiently high elongation to sustain the stresses induced without cracking is used. The propellant is zone cured within the motor case at high pressures equal to or approaching the pressure at which the motor will operate during combustion. A solid propellant motor with a burning time long enough that its spacecraft would be limited to a maximum acceleration of less than 1 g is provided by one version of the case bonded end burning solid propellant motor of the invention.

  7. Motor/generator

    Science.gov (United States)

    Hickam, Christopher Dale

    2008-05-13

    A motor/generator is provided for connecting between a transmission input shaft and an output shaft of a prime mover. The motor/generator may include a motor/generator housing, a stator mounted to the motor/generator housing, a rotor mounted at least partially within the motor/generator housing and rotatable about a rotor rotation axis, and a transmission-shaft coupler drivingly coupled to the rotor. The transmission-shaft coupler may include a clamp, which may include a base attached to the rotor and a plurality of adjustable jaws.

  8. Induction motor control design

    CERN Document Server

    Marino, Riccardo; Verrelli, Cristiano M

    2010-01-01

    ""Nonlinear and Adaptive Control Design for Induction Motors"" is a unified exposition of the most important steps and concerns in the design of estimation and control algorithms for induction motors. A single notation and modern nonlinear control terminology is used to make the book accessible to readers who are not experts in electric motors at the same time as giving a more theoretical control viewpoint to those who are. In order to increase readability, the book concentrates on the induction motor, eschewing the much more complex and less-well-understood control of asynchronous motors. The

  9. Validation and acceptance of synthetic infrared imagery

    Science.gov (United States)

    Smith, Moira I.; Bernhardt, Mark; Angell, Christopher R.; Hickman, Duncan; Whitehead, Philip; Patel, Dilip

    2004-08-01

    This paper describes the use of an image query database (IQ-DB) tool as a means of implementing a validation strategy for synthetic long-wave infrared images of sea clutter. Specifically it was required to determine the validity of the synthetic imagery for use in developing and testing automatic target detection algorithms. The strategy adopted for exploiting synthetic imagery is outlined and the key issues of validation and acceptance are discussed in detail. A wide range of image metrics has been developed to achieve pre-defined validation criteria. A number of these metrics, which include post processing algorithms, are presented. Furthermore, the IQ-DB provides a robust mechanism for configuration management and control of the large volume of data used. The implementation of the IQ-DB is reviewed in terms of its cardinal point specification and its central role in synthetic imagery validation and EOSS progressive acceptance.

  10. At the mercy of strategies: the role of motor representations in language understanding

    Directory of Open Access Journals (Sweden)

    Barbara eTomasino

    2013-02-01

    Full Text Available Classical cognitive theories hold that word representations in the brain are abstract and amodal, and are independent of the objects’ sensorimotor properties they refer to. An alternative hypothesis emphasises the importance of bodily processes in cognition: the representation of a concept appears to be crucially dependent upon perceptual-motor processes that relate to it. Thus, understanding action-related words would rely upon the same motor structures that also support the execution of the same actions. In this context, motor simulation represents a key component. Our approach is to draw parallels between the literature on mental rotation and the literature on action verb/sentence processing. Here we will discuss recent studies on mental imagery, mental rotation, and language that clearly demonstrate how motor simulation is neither automatic nor necessary to language understanding. These studies have shown that motor representations can or cannot be activated depending on the type of strategy the participants adopt to perform tasks involving motor phrases. On the one hand, participants may imagine the movement with the body parts used to carry out the actions described by the verbs (i.e., motor strategy; on the other, individuals may solve the task without simulating the corresponding movements (i.e., visual strategy. While it is not surprising that the motor strategy is at work when participants process action-related verbs, it is however striking that sensorimotor activation has been reported also for imageable concrete words with no motor content, for non-words with regular phonology, for pseudo-verb stimuli, and also for negations. Based on the extant literature, we will argue that implicit motor imagery is not uniquely used when a body-related stimulus is encountered, and that it is not the type of stimulus that automatically triggers the motor simulation but the type of strategy. Finally, we will also comment on the view that

  11. At the mercy of strategies: the role of motor representations in language understanding.

    Science.gov (United States)

    Tomasino, Barbara; Rumiati, Raffaella Ida

    2013-01-01

    Classical cognitive theories hold that word representations in the brain are abstract and amodal, and are independent of the objects' sensorimotor properties they refer to. An alternative hypothesis emphasizes the importance of bodily processes in cognition: the representation of a concept appears to be crucially dependent upon perceptual-motor processes that relate to it. Thus, understanding action-related words would rely upon the same motor structures that also support the execution of the same actions. In this context, motor simulation represents a key component. Our approach is to draw parallels between the literature on mental rotation and the literature on action verb/sentence processing. Here we will discuss recent studies on mental imagery, mental rotation, and language that clearly demonstrate how motor simulation is neither automatic nor necessary to language understanding. These studies have shown that motor representations can or cannot be activated depending on the type of strategy the participants adopt to perform tasks involving motor phrases. On the one hand, participants may imagine the movement with the body parts used to carry out the actions described by the verbs (i.e., motor strategy); on the other, individuals may solve the task without simulating the corresponding movements (i.e., visual strategy). While it is not surprising that the motor strategy is at work when participants process action-related verbs, it is however striking that sensorimotor activation has been reported also for imageable concrete words with no motor content, for "non-words" with regular phonology, for pseudo-verb stimuli, and also for negations. Based on the extant literature, we will argue that implicit motor imagery is not uniquely used when a body-related stimulus is encountered, and that it is not the type of stimulus that automatically triggers the motor simulation but the type of strategy. Finally, we will also comment on the view that sensorimotor activations

  12. Randall-Sundrum with AdS(7)

    CERN Document Server

    Bao, R; Bao, Ruoyu; Lykken, Joseph

    2005-01-01

    In the same sense that AdS_5 warped geometries arise naturally from Type IIB string theory with stacks of D3 branes, AdS_7 warped geometries arise naturally from M theory with stacks of M5 branes. We compactify two spatial dimensions of AdS_7 to get AdS_5 x \\Sigma^2, where \\Sigma^2 is e.g. a torus T^2 or a sphere S^2. The metric for \\Sigma inherits the same warp factor as appears in the AdS_5. Bulk fields generically have both Kaluza-Klein and winding modes associated with \\Sigma. In the effective 5d action these will contribute exotic new excitations. We analyze the 5d spectrum in detail for the case of a bulk scalar or a graviton in AdS_5 x T^2, in a setup which mimics the first Randall-Sundrum model. The results display several novel features, some of which might be observed in experiments at the LHC. For example, we obtain TeV scale string winding states without lowering the string scale. This is due to the double warping which is a generic feature of winding states along compactified AdS directions. Expe...

  13. Motor degradation prediction methods

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  14. Piezoelectric Motors, an Overview

    Directory of Open Access Journals (Sweden)

    Karl Spanner

    2016-02-01

    Full Text Available Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ultrasonic motors, inertia-drive, and piezo-walk-drive. In this review, a comprehensive summary of piezoelectric motors, with their classification from initial idea to recent progress, is presented. This review also includes some of the industrial and commercial applications of piezoelectric motors that are presently available in the market as actuators.

  15. Neuroplasticity & Motor Learning

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye

    is a measure of our ability to form and store a motor memory of the task. However, the initial memory of the task is labile and may be subject to interference. During and following motor learning plastic changes occur within the central nervous system. On one hand these changes are driven by motor practice......, on the other hand the changes underlie the formation of motor memory and the retention of improved motor performance. During motor learning changes may occur at many different levels within the central nervous system dependent on the type of task and training. Here, we demonstrate different studies from our......Practice of a new motor task is usually associated with an improvement in performance. Indeed, if we stop practicing and return the next day to the same task, we find that our performance has been maintained and may even be better than it was at the start of the first day. This improvement...

  16. USDA/FSA Imagery Programs - Public Map Gallery

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — Imagery programs are an important part of maintaining, creating and updating geospatial data at the USDA Farm Service Agency. Imagery acquisition is provided by the...

  17. NAIP = USDA FSA National Agricultural Imagery Program: 2003 - Present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The National Agriculture Imagery Program (NAIP) acquires aerial imagery during the agricultural growing seasons in the continental U.S. A primary goal of the NAIP...

  18. Dirac operator on fuzzy AdS2

    International Nuclear Information System (INIS)

    In this article we construct the chirality and Dirac operators on fuzzy AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space. (author)

  19. Dirac Operator on Noncommutative AdS_2

    CERN Document Server

    Fakhri, H

    2003-01-01

    In this article we construct the chirality and Dirac operators on noncommutative AdS_2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated with AdS_2. It is shown that the degeneracy of the spectrum present in the commutative AdS_2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.

  20. Dirac operator on fuzzy AdS2

    Science.gov (United States)

    Fakhri, Hossein; Imaanpur, Ali

    2003-03-01

    In this article we construct the chirality and Dirac operators on noncommutative AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.

  1. Dirac Operator on Fuzzy AdS_2

    OpenAIRE

    H. Fakhri; Imaanpur, A.

    2003-01-01

    In this article we construct the chirality and Dirac operators on noncommutative AdS_2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated with AdS_2. It is shown that the degeneracy of the spectrum present in the commutative AdS_2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.

  2. Radius-dependent gauge unification in AdS5

    OpenAIRE

    Choi, Kiwoon; Kim, Hyung Do; Kim, Ian-Woo

    2002-01-01

    We examine the relation of the 4-dimensional low energy coupling of bulk gauge boson in a slice of AdS5 to the 5-dimensional fundamental couplings as a function of the orbifold radius R. This allows us to address the gauge coupling unification in AdS5 by means of the radius running as well as the conventional momentum running. We then compute the radius dependence of 1-loop low energy couplings in generic AdS5 theory with 4-dimensional supersymmetry, and discuss the low energy predictions whe...

  3. Towards integrability for AdS3/CFT2

    CERN Document Server

    Sfondrini, Alessandro

    2014-01-01

    We review the recent progress towards applying worldsheet integrability techniques to the $AdS_3/CFT_2$ correspondence to find its all-loop S matrix and Bethe-Yang equations. We study in full detail the massive sector of $AdS_3\\times S^3\\times T^4$ superstrings supported by pure Ramond-Ramond (RR) fluxes. The extension of this machinery to accommodate massless modes, to the $AdS_3\\times S^3\\times S^3\\times S^1$ pure-RR background and to backgrounds supported by mixed background fluxes is also reviewed. While the results discussed here were found elsewhere, our exposition is original.

  4. On RPC Model of Satellite Imagery

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo; YUAN Xiuxiao

    2006-01-01

    The RPC model has recently raised considerable interest in the photogrammetry and remote sensing community. The RPC is a generalized sensor model that is capable of achieving high approximation accuracy. Unfortunately, the computation of the parameters of RPC model is subject to the initial of the parameter in all available literature. An algorithm for computation of parameters of RPC model without initial value is presented and tested on SPOT-5, CBERS-2, ERS-1 imageries. RPC model is suitable for both push-broom and SAR imagery.

  5. Dissociation Between Visual Attention and Visual Mental Imagery

    OpenAIRE

    Thompson, William L.; Hsiao, Yaling; Kosslyn, Stephen Michael

    2010-01-01

    Visual mental imagery (which involves generating and transforming visual mental representations, i.e., seeing with the mind's eye) and visual attention appear to be distinct processes. However, some researchers have claimed that imagery effects can be explained by appeal to attention (and thus, that imagery is nothing more than a form of attention). In this study, we used a size manipulation to demonstrate that imagery and attention are distinct processes. We reasoned that if participants are...

  6. Primary motor cortex activity reduction under the regulation of SMA by real-time fMRI

    Science.gov (United States)

    Guo, Jia; Zhao, Xiaojie; Li, Yi; Yao, Li; Chen, Kewei

    2012-03-01

    Real-time fMRI (rtfMRI) is a new technology which allows human subjects to observe and control their own BOLD signal change from one or more localized brain regions during scanning. Current rtfMRI-neurofeedback studies mainly focused on the target region itself without considering other related regions influenced by the real-time feedback. However, there always exits important directional influence between many of cooperative regions. On the other hand, rtfMRI based on motor imagery mainly aimed at somatomotor cortex or primary motor area, whereas supplement motor area (SMA) was a relatively more integrated and pivotal region. In this study, we investigated whether the activities of SMA can be controlled utilizing different motor imagery strategies, and whether there exists any possible impact on an unregulated but related region, primary motor cortex (M1). SMA was first localized using overt finger tapping task, the activities of SMA were feedback to subjects visually on line during each of two subsequent imagery motor movement sessions. All thirteen healthy participants were found to be able to successfully control their SMA activities by self-fit imagery strategies which involved no actual motor movements. The activation of right M1 was also found to be significantly reduced in both intensity and extent with the neurofeedback process targeted at SMA, suggestive that not only the part of motor cortex activities were influenced under the regulation of a key region SMA, but also the increased difference between SMA and M1 might reflect the potential learning effect.

  7. Conical singularities in AdS space time

    International Nuclear Information System (INIS)

    Full text: In recent years, the study of conformal gauge theories from 10-D has been motivated by the AdSd+1/CFTd correspondence, first conjectured by J. Maldacena. The aim of this work is to consider the d = 4 case by analysing the configuration of the N coincident D3 branes. In this context, the work shows that there is a duality between type IIB string theory in AdS5 x S5 and N = 4 SU(N) Super Yang-Mills Theory in the IR. The AdS5/CFT4 correspondence brought also new approaches to the strong coupling problem in QCD. Nowadays, there is a whole line of works that focus on the low dimensional correspondence AdS4/CFT3, like the application to graphene and topological insulators, and the AdS3/CFT2 correspondence, related with the entanglement entropy. In this work, we consider the vortex configuration solution to the AdS4 and AdS3 space-time. The most important motivation is to discuss the boundary theory resulting from these solutions. We have examined a straightforward approach to a holographic computation of the graphene and entanglement entropy in the presence of the conical singularity. After this analysis, we consider the scalar field in the bulk in the presence of this metrics and work out the compactification modes. Taking the holographic point of view, we study and discuss the resulting Green function. (author)

  8. Aerial Photography and Imagery, Ortho-Corrected, 2007 imagery over Eureka Township, Published in 2007, Eureka County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Ortho-Corrected dataset, was produced all or in part from Orthoimagery information as of 2007. It is described as '2007 imagery...

  9. Level Sets and Voronoi based Feature Extraction from any Imagery

    DEFF Research Database (Denmark)

    Sharma, O.; Anton, François; Mioc, Darka

    2012-01-01

    imagery, and 2D/3D acoustic images (from hydrographic surveys). The application involving satellite imagery shown in this paper is coastline detection, but the methodology can be easily applied to feature extraction on any king of imagery. A prototype application that is developed as part of this research...

  10. Wireless Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Hong-Chuan Yang

    2007-01-01

    Full Text Available We study the energy-efficient configuration of multihop paths with automatic repeat request (ARQ mechanism in wireless ad hoc networks. We adopt a cross-layer design approach and take both the quality of each radio hop and the battery capacity of each transmitting node into consideration. Under certain constraints on the maximum tolerable transmission delay and the required packet delivery ratio, we solve optimization problems to jointly schedule the transmitting power of each transmitting node and the retransmission limit over each hop. Numerical results demonstrate that the path configuration methods can either significantly reduce the average energy consumption per packet delivery or considerably extend the average lifetime of the multihop route.

  11. ADS National Programmes: Netherlands

    International Nuclear Information System (INIS)

    The ADS related activities within the Netherlands are concentrated at NRG. From 2000 to 2006, NRG supported SCK•CEN in their development of MYRRHA. The support was mainly devoted to Computational Fluid Dynamics (CFD) simulations for the windowless target option. This collaboration was prolonged within the framework of the EU FP6 EUROTRANS project. Eventually this lead to a solution strategy for the hydraulic (without heat transfer) evaluation of a windowless target with one free surface using an Eulerian-Eulerian modeling approach. As a second free surface was added to the target design later, this approach would need to be revisited. The developed approach was applied to an assess the feasibility of a three feeder windowless target design. This preliminary assessment confirmed that there were no serious show stoppers for a three feeder design. Another study undertaken using related to the windowless target was a preliminary assessment of the risk of lead-bismuth splashing in case of a sudden heat deposition by the beam, e.g. at beam startup or beam interuptions. Within the framework of the EU FP7 CDT project, a window target is currently being assessed thermalhydraulicly in collaboration with SCK•CEN. Within the EU FP5 ASCHLIM project, the state of the art with regard to turbulence modelling for CFD approaches was determined. It was concluded that accurate simulation of heat transport in HLM was not feasible, especially in natural or mixed convection regimes. Within the EU FP7 THINS project this issue is currently being treated. NRG assists the commercial CFD code vendor CD adapco in implementing and testing a promising, academically tested, algebraic heat flux model

  12. Dressing phases of AdS3/CFT2

    CERN Document Server

    Borsato, Riccardo; Sfondrini, Alessandro; Stefanski, Bogdan; Torrielli, Alessandro

    2013-01-01

    We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3 x S3 x T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly-coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their sub-leading order and compare it with recent one-loop perturbative results, and co

  13. Dressing phases of AdS3/CFT2

    Science.gov (United States)

    Borsato, Riccardo; Ohlsson Sax, Olof; Sfondrini, Alessandro; Stefański, Bogdan, Jr.; Torrielli, Alessandro

    2013-09-01

    We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3×S3×T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their subleading order and compare it with recent one-loop perturbative results and comment on their weak-coupling expansion.

  14. Chaos and hydrodynamics near AdS$_2$

    CERN Document Server

    Jensen, Kristan

    2016-01-01

    We revisit AdS$_2$ holography with the Sachdev-Ye-Kitaev models in mind. Our main result is to rewrite a generic theory of gravity near an AdS$_2$ throat as a novel hydrodynamics coupled to the correlation functions of a conformal quantum mechanics. This gives a prescription for the computation of $n$-point functions in the dual quantum mechanics. We thereby find that the dual is maximally chaotic.

  15. Anticipation by multi-modal association through an artificial mental imagery process

    Science.gov (United States)

    Gaona, Wilmer; Escobar, Esaú; Hermosillo, Jorge; Lara, Bruno

    2015-01-01

    Mental imagery has become a central issue in research laboratories seeking to emulate basic cognitive abilities in artificial agents. In this work, we propose a computational model to produce an anticipatory behaviour by means of a multi-modal off-line hebbian association. Unlike the current state of the art, we propose to apply hebbian learning during an internal sensorimotor simulation, emulating a process of mental imagery. We associate visual and tactile stimuli re-enacted by a long-term predictive simulation chain motivated by covert actions. As a result, we obtain a neural network which provides a robot with a mechanism to produce a visually conditioned obstacle avoidance behaviour. We developed our system in a physical Pioneer 3-DX robot and realised two experiments. In the first experiment we test our model on one individual navigating in two different mazes. In the second experiment we assess the robustness of the model by testing in a single environment five individuals trained under different conditions. We believe that our work offers an underpinning mechanism in cognitive robotics for the study of motor control strategies based on internal simulations. These strategies can be seen analogous to the mental imagery process known in humans, opening thus interesting pathways to the construction of upper-level grounded cognitive abilities.

  16. Aerial Photography and Imagery, Uncorrected, historic aerial imagery; 1931-1990, Published in 2006, Washoe County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Uncorrected dataset, was produced all or in part from Hardcopy Maps information as of 2006. It is described as 'historic aerial...

  17. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Taylor County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  18. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Pasco County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  19. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Leon County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  20. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Franklin County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  1. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Washington County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  2. Aerial Photography and Imagery, Ortho-Corrected - FL Bay Ortho Imagery Project Spring 2013

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This file references a single orthogonal imagery tile produced from nadir images captured by Pictometry International during the period of December 30th, 2012 and...

  3. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Palm Beach County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  4. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Glades County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  5. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Martin County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  6. Aerial Photography and Imagery, Ortho-Corrected - 2010 NAIP Imagery - Orange County

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set contains polygons delineating the seams boundary between acquired imagery used in the creation of DOQQs and compressed county mosaic (CCM). The DOQQ...

  7. Aerial Photography and Imagery, Ortho-Corrected, Six inch color imagery, Published in 2006, Harvey County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Aerial Photography and Imagery, Ortho-Corrected dataset, was produced all or in part from Orthoimagery information as of 2006. It is described as 'Six inch...

  8. Dichoptic fusion of thermal and intensified imagery

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.; Hoeven, M. van der

    2006-01-01

    Subjects used the dichoptic combination of a monocular image intensifier (NVG) and a monocular uncooled microbolometer (LWIR) to detect and localise both visual targets and camouflaged thermal targets while moving through a dimly lit complex environment. The NVG imagery enabled the subjects to move

  9. Applying daytime colors to multiband nightvision imagery

    NARCIS (Netherlands)

    Toet, A.

    2003-01-01

    We present a method to give (fused) multiband night-time imagery a natural day-time color appearance. For input, the method requires a false color RGB image that is produced by mapping 3 individual bands (or the first 3 principal components) of a multiband nightvision system to the respective channe

  10. Imagery Rescripting across Disorders: A Practical Guide

    Science.gov (United States)

    Stopa, Lusia

    2011-01-01

    Intrusive images occur in many disorders and, as well as causing distress, they frequently represent important negative meanings about the self, other people, or the world. Imagery rescripting describes a set of therapeutic techniques that are aimed at changing these negative meanings. This special series focuses on when and how to do imagery…

  11. Perceptual evaluation of colorized nighttime imagery

    NARCIS (Netherlands)

    Toet, A.; Jong, M.J. de; Hogervorst, M.A.; Hooge, I.T.C.

    2014-01-01

    We recently presented a color transform that produces fused nighttime imagery with a realistic color appearance (Hogervorst & Toet, 2010, Information Fusion, 11-2, 69-77). To assess the practical value of this transform we performed two experiments in which we compared human scene recognition for mo

  12. Image enhancement for noisy color imagery

    NARCIS (Netherlands)

    Dijk, J.; Hollander, R.J.M. den

    2008-01-01

    Recently new techniques for night vision cameras are developed. So-called EMCCD cameras are able to record color information about the scene. However, in low-light situations this imagery becomes noisy. This is also the case for normal CCD cameras in dark situations or in shadowed areas. In this pap

  13. Lehrbuch Guided Imagery in Music (GIM)

    DEFF Research Database (Denmark)

    Maack, Carola; Geiger, Edith Maria

    Guided Imagery in Music (GIM) ist eine musikpsychotherapeutische Methode, bei welcher der Patient eine Auswahl meist klassischer Musik in einem entspannten Zustand hört und sein Erleben (= Imaginationen) der Therapeutin mitteilt. Theoretische Hintergründe, klinische Anwendung, sowie methodenspezi...

  14. Imagery as a Facilitator of Semantic Integration.

    Science.gov (United States)

    Weed, Keri; Ryan, Ellen Bouchard

    The relationship between processing style (either auditory or visual) and sentence and imagery strategies was investigated with a sample of 80 second-grade children. Assignment to auditory- and visual-processor groups was based on subjects' recall of 16 pictograph sequences, four of which included visual interference and four of which included…

  15. Assessing mental imagery in clinical psychology: A review of imagery measures and a guiding framework

    OpenAIRE

    Pearson, David G.; Deeprose, Catherine; Wallace-Hadrill, Sophie M.A.; Heyes, Stephanie Burnett; Holmes, Emily A.

    2013-01-01

    Mental imagery is an under-explored field in clinical psychology research but presents a topic of potential interest and relevance across many clinical disorders, including social phobia, schizophrenia, depression, and post-traumatic stress disorder. There is currently a lack of a guiding framework from which clinicians may select the domains or associated measures most likely to be of appropriate use in mental imagery research. We adopt an interdisciplinary approach and present a review of s...

  16. Tobacco industry response to public health concern: a content analysis of cigarette ads.

    Science.gov (United States)

    Warner, K E

    1985-01-01

    Public awareness of the health hazards of smoking intensified when the subject received national publicity. To assess tobacco industry tactics to counter adverse publicity, we performed a content analysis of cigarette ads in selected issues of Time magazine, for selected years from 1929-84. The analysis showed direct responses to health concerns in all of the years of major smoking-and-health "events," with the possible exception of 1964, the year of the first Surgeon General's report. During these years large percentages of ads emphasized health themes instead of the conventional cigarette ad imagery. On average, health-theme ads have a higher verbal content than the more pictorial traditional ads. Correspondingly, they employ many fewer models. Health-theme ads tend to emphasize the "technological fix," such as the scientifically designed filter and the low-tar cigarette. Subtle changes in cigarette advertising include the elimination of visible smoke from ads. A decade's concentration on standard health themes, prompted by the "tar wars" of the 1970s, appears to have ended in the 1980s. Advertisers seem to have reverted to the "good times" nonhealth imagery of a bygone era, though possibly to deliver a subtle implicit health message. Understanding industry advertising tactics can assist public health professionals in developing insights into the promotion of smoking and in formulating smoking control strategies. Though highly exploratory and tentative in nature, this study is offered in the spirit of increasing such understanding. PMID:3997535

  17. Motor degradation prediction methods

    International Nuclear Information System (INIS)

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor's duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures

  18. Computer vision-based technologies and commercial best practices for the advancement of the motion imagery tradecraft

    Science.gov (United States)

    Phipps, Marja; Capel, David; Srinivasan, James

    2014-06-01

    Motion imagery capabilities within the Department of Defense/Intelligence Community (DoD/IC) have advanced significantly over the last decade, attempting to meet continuously growing data collection, video processing and analytical demands in operationally challenging environments. The motion imagery tradecraft has evolved accordingly, enabling teams of analysts to effectively exploit data and generate intelligence reports across multiple phases in structured Full Motion Video (FMV) Processing Exploitation and Dissemination (PED) cells. Yet now the operational requirements are drastically changing. The exponential growth in motion imagery data continues, but to this the community adds multi-INT data, interoperability with existing and emerging systems, expanded data access, nontraditional users, collaboration, automation, and support for ad hoc configurations beyond the current FMV PED cells. To break from the legacy system lifecycle, we look towards a technology application and commercial adoption model course which will meet these future Intelligence, Surveillance and Reconnaissance (ISR) challenges. In this paper, we explore the application of cutting edge computer vision technology to meet existing FMV PED shortfalls and address future capability gaps. For example, real-time georegistration services developed from computer-vision-based feature tracking, multiple-view geometry, and statistical methods allow the fusion of motion imagery with other georeferenced information sources - providing unparalleled situational awareness. We then describe how these motion imagery capabilities may be readily deployed in a dynamically integrated analytical environment; employing an extensible framework, leveraging scalable enterprise-wide infrastructure and following commercial best practices.

  19. Motor Axon Pathfinding

    OpenAIRE

    Bonanomi, Dario; Pfaff, Samuel L

    2010-01-01

    Motor neurons are functionally related, but represent a diverse collection of cells that show strict preferences for specific axon pathways during embryonic development. In this article, we describe the ligands and receptors that guide motor axons as they extend toward their peripheral muscle targets. Motor neurons share similar guidance molecules with many other neuronal types, thus one challenge in the field of axon guidance has been to understand how the vast complexity of brain connection...

  20. Discrimination in Online Ad Delivery

    OpenAIRE

    Sweeney, Latanya

    2013-01-01

    A Google search for a person's name, such as "Trevon Jones", may yield a personalized ad for public records about Trevon that may be neutral, such as "Looking for Trevon Jones?", or may be suggestive of an arrest record, such as "Trevon Jones, Arrested?". This writing investigates the delivery of these kinds of ads by Google AdSense using a sample of racially associated names and finds statistically significant discrimination in ad delivery based on searches of 2184 racially associated person...

  1. Cryogenic Electric Motor Tested

    Science.gov (United States)

    Brown, Gerald V.

    2004-01-01

    Technology for pollution-free "electric flight" is being evaluated in a number of NASA Glenn Research Center programs. One approach is to drive propulsive fans or propellers with electric motors powered by fuel cells running on hydrogen. For large transport aircraft, conventional electric motors are far too heavy to be feasible. However, since hydrogen fuel would almost surely be carried as liquid, a propulsive electric motor could be cooled to near liquid hydrogen temperature (-423 F) by using the fuel for cooling before it goes to the fuel cells. Motor windings could be either superconducting or high purity normal copper or aluminum. The electrical resistance of pure metals can drop to 1/100th or less of their room-temperature resistance at liquid hydrogen temperature. In either case, super or normal, much higher current density is possible in motor windings. This leads to more compact motors that are projected to produce 20 hp/lb or more in large sizes, in comparison to on the order of 2 hp/lb for large conventional motors. High power density is the major goal. To support cryogenic motor development, we have designed and built in-house a small motor (7-in. outside diameter) for operation in liquid nitrogen.

  2. Control motor brushless sensorless

    OpenAIRE

    Solchaga Pérez de Lazárraga, Gonzalo

    2015-01-01

    El proyecto consiste en la creación de un circuito capaz de controlar la velocidad de un motor brushless sensorless. Este tipo de motores eléctricos tienen como característica que no tienen escobillas para cambiar la polaridad del bobinado de su interior y tampoco precisan de un sensor que indique que ha realizado una vuelta. Los motores brushless que son controlados por este tipo de circuitos son específicos para aeronaves no tripuladas y requieren un diseño diferente a un motor brushless pe...

  3. ADS National Programmes: Germany

    International Nuclear Information System (INIS)

    The German R&D programme for ADS development is related to the partitioning and transmutation of spent fuel. This programme is implemented mainly by the three national research centres belonging to the Helmholtz Association, i.e. Karlsruhe Institute of Technology (KIT), Forschungszentrum Jülich (FZJ) in cooperation with the Technical University of Aachen (RWTH Aachen) and the Helmholtz Zentrum Dresden Rossendorf (HZDR). The main purpose of this R&D programme is the prospect to manage the high level radioactive waste such as to reduce the burden on a final repository. P&T does not eliminate the need for a final repository whatever the strategy, but it allows the reduction of the radio-toxicity associated with radioactive waste, the increase of the repository capacity as a consequence of the reduction of masses to be stored and their associated residual heat load. Different fuel cycle scenarios to implement P&T can be envisaged. These scenarios have been evaluated to identify the impact of P&T on the characteristics, number and deployment pace of the installations of the fuel cycle (reprocessing, fuel fabrication, storage etc). Almost all activities conducted in the R&D programme are embedded in European and international projects and initiatives. In the following more details on the relevant components of the R&D programme are summarized

  4. Complexity Growth for AdS Black Holes

    CERN Document Server

    Cai, Rong-Gen; Wang, Shao-Jiang; Yang, Run-Qiu; Peng, Rong-Hui

    2016-01-01

    We further investigate the Complexity-Action (CA) duality conjecture for stationary anti de-Sitter (AdS) black holes and derive some exact results for the growth rate of action within Wheeler-DeWitt (WDW) patch at late time approximation, which is dual to the growth rate of quantum complexity of holographic state. Based on the results from the general $D$-dimensional Reissner-Nordstr\\"{o}m (RN)-AdS black hole, rotating/charged Ba\\~{n}ados-Teitelboim-Zanelli (BTZ) black hole, Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a new complexity bound but leave unchanged the conjecture that the stationary AdS black hole in Einstein gravity is the fastest computer in nature.

  5. Comparison of motor praxis and performance in children with varying levels of developmental coordination disorder.

    Science.gov (United States)

    Chang, Shao-Hsia; Yu, Nan-Ying

    2016-08-01

    The praxis test is a less well-documented method to determine functional manifestations of childhood dyspraxia. For this study, children aged 6-8years were recruited as follows: 17 children with DCD, 18 at risk of DCD and 35 without obvious problems in motor coordination. The Movement Assessment Battery for Children (MABC-2) was used to measure motor performance and identify the motor incoordination. This study developed a battery of tests to assess limb praxis using a praxis imagery questionnaire, gesture representation, and questions about knowledge of object use. In the comparison of subtests within the praxis test, significant differences were observed across groups on the praxis imagery questionnaire and gesture representation tests but not on knowledge of object use. Similar results were observed in the correlation analyses, in which a weak relationship between MABC-2 and praxis tests was observed. The DCD group had lower scores on the praxis imagery questionnaire, whereas the group at risk of DCD had lower scores on most gesture production tests. Our study provides a better understanding of the nature of the childhood dyspraxia and sheds light on its effect on motor coordination to identify praxis tests with specific clinical meanings in children with movement disorders. PMID:27101560

  6. Constructing the AdS dual of a Fermi liquid: AdS Black holes with Dirac hair

    CERN Document Server

    \\vCubrović, Mihailo; Schalm, Koenraad

    2010-01-01

    We provide new evidence that the holographic dual to a strongly coupled charged Fermi Liquid has a non-zero fermion density in the bulk. We show that the pole-strength of the stable quasiparticle characterizing the Fermi surface is encoded in the spatially averaged AdS probability density of a single normalizable fermion wavefunction in AdS. Recalling Migdal's theorem which relates the pole strength to the Fermi-Dirac characteristic discontinuity in the number density at $\\ome_F$, we conclude that the AdS dual of a Fermi liquid is described by occupied on-shell fermionic modes in AdS. Encoding the occupied levels in the total probability density of the fermion field directly, we show that an AdS Reissner-Nordstr\\"{o}m black hole in a theory with charged fermions has a critical temperature, at which the system undergoes a first-order transition to a black hole with a non-vanishing profile for the bulk fermion field. Thermodynamics and spectral analysis confirm that the solution with non-zero AdS fermion-profil...

  7. Radargrammetric Digital Surface Models Generation from Terrasar-X Imagery: Case Studies, Problems and Potentialities

    Science.gov (United States)

    Capaldo, P.; Crespi, M.; Fratarcangeli, F.; Nascetti, A.; Pieralice, F.

    2012-07-01

    The interest for the radargrammetric approach to Digital Surface Models (DSMs) generation has been growing in last years thanks to the availability of very high resolution imagery acquired by new SAR (Synthetic Aperture Radar) sensors, as COSMO-SkyMed, Radarsat-2 and TerraSAR-X, which are able to supply imagery up to 1 m ground resolution. DSMs radargrammetric generation approach consists of two basic steps, as for the standard photogrammetry applied to optical imagery: the imagery (at least a stereo pair) orientation and the image matching for the generation of the points cloud. The steps of the radargrammetric DSMs generation have been implemented into SISAR (Software per Immagini Satellitari ad Alta Risoluzione), a scientific software developed at Geodesy and Geomatics Institute of the University of Rome "La Sapienza". Moreover, starting from the radargrammetric orientation model, a tool for the Rational Polynomial Coefficients (RPCs) for SAR images have been implemented. The possibility to generate RPCs, re-parametrizing a rigorous orientation model through a standardized set of coefficients which can be managed by a Rational Polynomial Coefficients (RPFs) model (similarly to optical high resolution imagery) sounds of particular interest since, at present, the most part of SAR imagery (except from Radarsat-2) is not supplied with RPCs, although the corresponding RPFs model is available in several commercial software. In particular the RPCs model has been used in the matching process and in the stereo restitution for the DSMs generation, with the advantage of shorter computational time. This paper discusses the application and the results of the implemented algorithm for radargrammetric DSMs generation from TerraSAR-X SpotLight imagery, acquired in Spotlight mode over Trento (Northern Italy). Urban and extra-urban (forested, cultivated) areas were considered in two different tiles, and a final overall accuracy ranging from 4.5 to 6 meters was achieved as regards

  8. CHOSEN ASPECTS OF THE PRODUCTION OF THE BASIC MAP USING UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    M. Kedzierski

    2016-06-01

    Full Text Available For several years there has been an increasing interest in the use of unmanned aerial vehicles in acquiring image data from a low altitude. Considering the cost-effectiveness of the flight time of UAVs vs. conventional airplanes, the use of the former is advantageous when generating large scale accurate ortophotos. Through the development of UAV imagery, we can update large-scale basic maps. These maps are cartographic products which are used for registration, economic, and strategic planning. On the basis of these maps other cartographic maps are produced, for example maps used building planning. The article presents an assessesment of the usefulness of orthophotos based on UAV imagery to upgrade the basic map. In the research a compact, non-metric camera, mounted on a fixed wing powered by an electric motor was used. The tested area covered flat, agricultural and woodland terrains. The processing and analysis of orthorectification were carried out with the INPHO UASMaster programme. Due to the effect of UAV instability on low-altitude imagery, the use of non-metric digital cameras and the low-accuracy GPS-INS sensors, the geometry of images is visibly lower were compared to conventional digital aerial photos (large values of phi and kappa angles. Therefore, typically, low-altitude images require large along- and across-track direction overlap – usually above 70 %. As a result of the research orthoimages were obtained with a resolution of 0.06 meters and a horizontal accuracy of 0.10m. Digitized basic maps were used as the reference data. The accuracy of orthoimages vs. basic maps was estimated based on the study and on the available reference sources. As a result, it was found that the geometric accuracy and interpretative advantages of the final orthoimages allow the updating of basic maps. It is estimated that such an update of basic maps based on UAV imagery reduces processing time by approx. 40%.

  9. Chosen Aspects of the Production of the Basic Map Using Uav Imagery

    Science.gov (United States)

    Kedzierski, M.; Fryskowska, A.; Wierzbicki, D.; Nerc, P.

    2016-06-01

    For several years there has been an increasing interest in the use of unmanned aerial vehicles in acquiring image data from a low altitude. Considering the cost-effectiveness of the flight time of UAVs vs. conventional airplanes, the use of the former is advantageous when generating large scale accurate ortophotos. Through the development of UAV imagery, we can update large-scale basic maps. These maps are cartographic products which are used for registration, economic, and strategic planning. On the basis of these maps other cartographic maps are produced, for example maps used building planning. The article presents an assessesment of the usefulness of orthophotos based on UAV imagery to upgrade the basic map. In the research a compact, non-metric camera, mounted on a fixed wing powered by an electric motor was used. The tested area covered flat, agricultural and woodland terrains. The processing and analysis of orthorectification were carried out with the INPHO UASMaster programme. Due to the effect of UAV instability on low-altitude imagery, the use of non-metric digital cameras and the low-accuracy GPS-INS sensors, the geometry of images is visibly lower were compared to conventional digital aerial photos (large values of phi and kappa angles). Therefore, typically, low-altitude images require large along- and across-track direction overlap - usually above 70 %. As a result of the research orthoimages were obtained with a resolution of 0.06 meters and a horizontal accuracy of 0.10m. Digitized basic maps were used as the reference data. The accuracy of orthoimages vs. basic maps was estimated based on the study and on the available reference sources. As a result, it was found that the geometric accuracy and interpretative advantages of the final orthoimages allow the updating of basic maps. It is estimated that such an update of basic maps based on UAV imagery reduces processing time by approx. 40%.

  10. Different views of AEGIS / AD-6 Experiment (AD facility) AD-6

    CERN Multimedia

    Maximilien Brice

    2012-01-01

    Different views of AEGIS / AD-6 Experiment (AD facility) in July of 2012. The visible parts are the positron accumulator (blue structures on top of of the antiproton extraction line) and the 5T magnet which traps the antiprotons.

  11. Global geometric properties of AdS space and the AdS/CFT correspondence

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Poisson kernels and relations between them for a massive scalar field in a unit ball Bn with Hua's metric and conformal flat metric are obtained by describing the Bn as a submanifold of an (n+1)-dimensional embedding space. Global geometric properties of the AdS space are discussed. We show that the(n+1)-dimensional AdS space AdSn+1 is isomorphic to RP1×Bn and boundary of the AdS is isomorphic to RP1×Sn-1. Bulk-boundary propagator and the AdS/CFT like correspondence are demonstrated based on these global geometric properties of the RP1×Bn.

  12. AdS-Carroll Branes

    CERN Document Server

    Clark, T E

    2016-01-01

    Coset methods are used to determine the action of a co-dimension one brane (domain wall) embedded in (d+1)-dimensional AdS space in the Carroll limit in which the speed of light goes to zero. The action is invariant under the non-linearly realized symmetries of the AdS-Carroll spacetime. The Nambu-Goldstone field exhibits a static spatial distribution for the brane with a time varying momentum density related to the brane's spatial shape as well as the AdS-C geometry. The AdS-C vector field dual theory is obtained.

  13. The Role of Sensory-Motor Information in Object Recognition: Evidence from Category-Specific Visual Agnosia

    Science.gov (United States)

    Wolk, D.A.; Coslett, H.B.; Glosser, G.

    2005-01-01

    The role of sensory-motor representations in object recognition was investigated in experiments involving AD, a patient with mild visual agnosia who was impaired in the recognition of visually presented living as compared to non-living entities. AD named visually presented items for which sensory-motor information was available significantly more…

  14. Preparation of tungsten disulfide motor oil and its tribological characteristics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Through using mineral oil and synthetic oil to deploy the semisynthesis base oil, modifying the surfaces of ultrafine tungsten disulfide grains by surface chemical embellishment and adsorption embellishment to make them suspended steadily in the base oil as solid lubricating additive, and adding some function additives, the tungsten disulfide motor oil was prepared. The tribological characteristics of this kind motor oil and the well-known motor oils in our country and overseas were studied. The results show that the oil film strength of this kind of motor oil is respectively 1.06 and 1.38 times of that of shell helix ultra motor oil and great wall motor oil, and its sintering load is 1.75 and 2.33 times of that of them, and when tested under 392 N, 1 450 r/min and 30 min, the friction coefficients of friction pairs lubricated by the tungsten disulfide motor oil decrease with the increase of time, meanwhile, the diameter of worn spot is small, and the surface of worn spot is smooth, and no obvious furrows appear. The experiments indicate that the tungsten disulfide motor oil has the better antiwear, antifriction and extreme pressure properties than the well-known motor oils.

  15. Entanglement entropy for free scalar fields in AdS

    CERN Document Server

    Sugishita, Sotaro

    2016-01-01

    We compute entanglement entropy for free massive scalar fields in anti-de Sitter (AdS) space. The entangling surface is a minimal surface whose boundary is a sphere at the boundary of AdS. The entropy can be evaluated from the thermal free energy of the fields on a topological black hole by using the replica method. In odd-dimensional AdS, exact expressions of the Renyi entropy S_n are obtained for arbitrary n. We also evaluate 1-loop corrections coming from the scalar fields to holographic entanglement entropy. Applying the results, we compute the leading difference of entanglement entropy between two holographic CFTs related by a renormalization group flow triggered by a double trace deformation. The difference is proportional to the shift of a central charge under the flow.

  16. Detailed ultraviolet asymptotics for AdS scalar field perturbations

    CERN Document Server

    Evnin, Oleg

    2016-01-01

    We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.

  17. Asymptotically AdS spacetimes with a timelike Kasner singularity

    Science.gov (United States)

    Ren, Jie

    2016-07-01

    Exact solutions to Einstein's equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution's appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.

  18. Microstates at the boundary of AdS

    CERN Document Server

    Mathur, Samir D

    2011-01-01

    The bound states of the D1D5 brane system have a known gravitational description: flat asymptotics, an anti-de Sitter region, and a 'cap' ending the AdS region. We construct perturbations that correspond to the action of chiral algebra generators on Ramond ground states of D1D5 branes. Abstract arguments in the literature suggest that the perturbation should be pure gauge in the AdS region; our perturbation indeed has this structure, with the nontrivial deformation of the geometry occurring at the 'neck' between the AdS region and asymptotic infinity. This 'non-gauge' deformation is needed to provide the nonzero energy and momentum carried by the perturbation. We also suggest implications this structure may have for the majority of microstates which live at the cap.

  19. Null warped AdS in higher spin gravity

    CERN Document Server

    Breunhoelder, Veronika; Grumiller, Daniel; Prohazka, Stefan

    2015-01-01

    We equip three-dimensional spin-3 gravity in the principal embedding with a new set of boundary conditions that we call "asymptotically null warped AdS". We find a chiral copy of the Polyakov-Bershadsky algebra as asymptotic symmetry algebra, reminiscent of the situation in topologically massive gravity with strict null warped AdS boundary conditions. We prove the invertibility of the map between zuvielbein and metric variables and construct a global gauge transformation to half of AdS spin-3 gravity in the diagonal embedding. This explains why the theory is chiral and why the Polyakov-Bershadsky algebra arises. We then introduce chemical potentials, derive the entropy, free energy, and the holographic response functions, and conclude with a discussion.

  20. New massive gravity and AdS(4) counterterms.

    Science.gov (United States)

    Jatkar, Dileep P; Sinha, Aninda

    2011-04-29

    We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory. PMID:21635026

  1. Towards integrability for AdS3/CFT2

    International Nuclear Information System (INIS)

    We review the recent progress towards applying worldsheet integrability techniques to the AdS3/CFT2 correspondence to find its all-loop S matrix and Bethe–Yang equations. We study in full detail the massive sector of AdS3×S3×T4 superstrings supported by pure Ramond–Ramond (RR) fluxes. The extension of this machinery to accommodate massless modes, to the AdS3×S3×S3×S1 pure-RR background and to backgrounds supported by mixed background fluxes is also reviewed. While the results discussed here were found elsewhere, our presentation sometimes deviates from the one found in the original literature in an effort to be pedagogical and self-contained. (topical review)

  2. Logarithmic conformal field theories and AdS correspondence

    OpenAIRE

    Khorrami, A. M. Ghezelbash. M.; Aghamohammadi, A

    1998-01-01

    We generalize the Maldacena correspondence to the logarithmic conformal field theories. We study the correspondence between field theories in (d+1)-dimensional AdS space and the d-dimensional logarithmic conformal field theories in the boundary of $AdS_{d+1}$. Using this correspondence, we get the n-point functions of the corresponding logarithmic conformal field theory in d-dimensions.

  3. MISR Motor Data V003

    Data.gov (United States)

    National Aeronautics and Space Administration — This file contains the output for the Level 1A Motor data (Suggested Usage: MISR SCF processing needs the MISR motor data samples for the analysis of motor...

  4. Phases of Global AdS Black Holes

    CERN Document Server

    Basu, Pallab; Subramanian, P N Bala

    2016-01-01

    We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ($AdS_4$) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.

  5. Phases of global AdS black holes

    Science.gov (United States)

    Basu, Pallab; Krishnan, Chethan; Subramanian, P. N. Bala

    2016-06-01

    We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ( AdS 4) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.

  6. Mixed-symmetry fields in AdS(5), conformal fields, and AdS/CFT

    CERN Document Server

    Metsaev, R R

    2014-01-01

    Mixed-symmetry arbitrary spin massive, massless, and self-dual massive fields in AdS(5) are studied. Light-cone gauge actions for such fields leading to decoupled equations of motion are constructed. Light-cone gauge formulation of mixed-symmetry anomalous conformal currents and shadows in 4d flat space is also developed. AdS/CFT correspondence for normalizable and non-normalizable modes of mixed-symmetry AdS fields and the respective boundary mixed-symmetry anomalous conformal currents and shadows is studied. We demonstrate that the light-cone gauge action for massive mixed-symmetry AdS field evaluated on solution of the Dirichlet problem amounts to the light-cone gauge 2-point vertex of mixed-symmetry anomalous shadow. Also we show that UV divergence of the action for mixed-symmetry massive AdS field with some particular value of mass parameter evaluated on the Dirichlet problem amounts to the action of long mixed-symmetry conformal field, while UV divergence of the action for mixed-symmetry massless AdS fi...

  7. Compact AdS space, Brane geometry and the AdS/CFT correspondence

    CERN Document Server

    Boschi-Filho, H; Boschi-Filho, Henrique; Braga, Nelson R. F.

    2002-01-01

    The AdS/CFT correspondence can be realized in spaces that are globally different but share the same asymptotic behavior. Two known cases are: a compact AdS space and the space generated by a large number of coincident branes. We discuss the physical consistency, in the sense of the Cauchy problem, of these two formulations. We show that the role of the boundary in the compact AdS space is equivalent to that of the flat asymptotic region in the brane space. We also show, by introducing a second coordinate chart for the pure AdS space, that a point at its spatial infinity corresponds to a horizon in the brane system.

  8. Coloring night vision imagery for depth perception

    Institute of Scientific and Technical Information of China (English)

    Xiaojing Gu; Shaoyuan Sun; Jian'an Fang

    2009-01-01

    Depth perception for night vision(NV)imagery could largely improve scene comprehension.We present a novel scheme to give fused multi-band NV imagery smoothly natural color appearance as well as depth sense from color.Our approach is based on simulating color cues by varying saturation values of each object in the color NV image,in correspondence with the ratio between the infrared and low-light-level sensor outputs which in practice is the depth feature for same materials.We render the NV image segment-by-segment by taking advantage of image segmentation,dominant color transfer,saturation variation,and image fusion.Experiments have shown that the proposed scheme can achieve satisfying results.

  9. Guided Imagery and Music with Cancer Survivors

    DEFF Research Database (Denmark)

    Bonde, Lars Ole; Thomasen, Ellen

    at vise, om receptiv musikterapi (Guided Imagery and Music/ GIM*) kan forbedre udskrevne/færdigbehandlede cancer-patienters stemningsleje (mood) og livskvalitet. Den kvantitative effektundersøgelse skal vise, om GIM-terapien har en målbar effekt, mens den kvalitative, fænomenologisk...... potentiale i en cancer-rehabiliteringsproces, dels at gøre nogle erfaringer med undersøgelsesdesignet og de valgte undersøgelsesredskaber (selvrapporteringsskemaer), så der kan fastlægges nogle klinisk relevante effektmål for et større projekt med kontrolgruppe (30 deltagere).: 6 frivillige deltagere får......-hermeneutiske undersøgelse af deltagernes oplevelser (indre forestillingsbilleder) skal vise, hvordan GIM-terapien påvirker selvopfattelsen, stemningslejet, mestringen af følelser og livskvaliteten. Flere mindre forskningsprojekter i USA og Tyskland har indikeret, at receptiv musikterapi/ Guided Imagery and Music (GIM) kan...

  10. Neural decoding of visual imagery during sleep.

    Science.gov (United States)

    Horikawa, T; Tamaki, M; Miyawaki, Y; Kamitani, Y

    2013-05-01

    Visual imagery during sleep has long been a topic of persistent speculation, but its private nature has hampered objective analysis. Here we present a neural decoding approach in which machine-learning models predict the contents of visual imagery during the sleep-onset period, given measured brain activity, by discovering links between human functional magnetic resonance imaging patterns and verbal reports with the assistance of lexical and image databases. Decoding models trained on stimulus-induced brain activity in visual cortical areas showed accurate classification, detection, and identification of contents. Our findings demonstrate that specific visual experience during sleep is represented by brain activity patterns shared by stimulus perception, providing a means to uncover subjective contents of dreaming using objective neural measurement. PMID:23558170

  11. Assessing mental imagery in clinical psychology: a review of imagery measures and a guiding framework.

    Science.gov (United States)

    Pearson, David G; Deeprose, Catherine; Wallace-Hadrill, Sophie M A; Burnett Heyes, Stephanie; Holmes, Emily A

    2013-02-01

    Mental imagery is an under-explored field in clinical psychology research but presents a topic of potential interest and relevance across many clinical disorders, including social phobia, schizophrenia, depression, and post-traumatic stress disorder. There is currently a lack of a guiding framework from which clinicians may select the domains or associated measures most likely to be of appropriate use in mental imagery research. We adopt an interdisciplinary approach and present a review of studies across experimental psychology and clinical psychology in order to highlight the key domains and measures most likely to be of relevance. This includes a consideration of methods for experimentally assessing the generation, maintenance, inspection and transformation of mental images; as well as subjective measures of characteristics such as image vividness and clarity. We present a guiding framework in which we propose that cognitive, subjective and clinical aspects of imagery should be explored in future research. The guiding framework aims to assist researchers in the selection of measures for assessing those aspects of mental imagery that are of most relevance to clinical psychology. We propose that a greater understanding of the role of mental imagery in clinical disorders will help drive forward advances in both theory and treatment.

  12. Maritime target identification in gated viewing imagery

    Science.gov (United States)

    Hammer, Marcus; Hebel, Marcus; Arens, Michael

    2015-10-01

    The growing interest in unmanned surface vehicles, accident avoidance for naval vessels and automated maritime surveillance leads to a growing need for automatic detection, classification and pose estimation of maritime objects in medium and long ranges. Laser radar imagery is a well proven tool for near to medium range, but up to now for higher distances neither the sensor range nor the sensor resolution was satisfying. As a result of the mentioned limitations of laser radar imagery the potential of laser illuminated gated viewing for automated classification and pose estimation was investigated. The paper presents new techniques for segmentation, pose estimation and model-based identification of naval vessels in gated viewing imagery in comparison with the corresponding results of long range data acquired with a focal plane array laser radar system. The pose estimation in the gated viewing data is directly connected with the model-based identification which makes use of the outline of the object. By setting a sufficient narrow gate, the distance gap between the upper part of the ship and the background leads to an automatic segmentation. By setting the gate the distance to the object is roughly known. With this distance and the imaging properties of the camera, the width of the object perpendicular to the line of sight can be calculated. For each ship in the model library a set of possible 2D appearances in the known distance is calculated and the resulting contours are compared with the measured 2D outline. The result is a match error for each reasonable orientation of each model of the library. The result gained from the gated viewing data is compared with the results of target identification by laser radar imagery of the same maritime objects.

  13. Improved VIIRS and MODIS SST Imagery

    OpenAIRE

    Irina Gladkova; Alexander Ignatov; Fazlul Shahriar; Yury Kihai; Don Hillger; Boris Petrenko

    2016-01-01

    Moderate Resolution Imaging Spectroradiometers (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) radiometers, flown onboard Terra/Aqua and Suomi National Polar-orbiting Partnership (S-NPP)/Joint Polar Satellite System (JPSS) satellites, are capable of providing superior sea surface temperature (SST) imagery. However, the swath data of these multi-detector sensors are subject to several artifacts including bow-tie distortions and striping, and require special pre-processing steps. ...

  14. Mental imagery affects subsequent automatic defense responses

    Directory of Open Access Journals (Sweden)

    Muriel A Hagenaars

    2015-06-01

    Full Text Available Automatic defense responses promote survival and appropriate action under threat. They have also been associated with the development of threat-related psychiatric syndromes. Targeting such automatic responses during threat may be useful in populations with frequent threat exposure. Here, two experiments explored whether mental imagery as a pre-trauma manipulation could influence fear bradycardia (a core characteristic of freezing during subsequent analogue trauma (affective picture viewing. Image-based interventions have proven successful in the treatment of threat-related disorders, and are easily applicable. In Experiment 1 43 healthy participants were randomly assigned to an imagery script condition. Participants executed a passive viewing task with blocks of neutral, pleasant and unpleasant pictures after listening to an auditory script that was either related (with a positive or a negative outcome or unrelated to the unpleasant pictures from the passive viewing task. Heart rate was assessed during script listening and during passive viewing. Imagining negative related scripts resulted in greater bradycardia (neutral-unpleasant contrast than imagining positive scripts, especially unrelated. This effect was replicated in Experiment 2 (N = 51, again in the neutral-unpleasant contrast. An extra no-script condition showed that bradycardia was not induced by the negative related script, but rather that a positive script attenuated bradycardia. These preliminary results might indicate reduced vigilance after unrelated positive events. Future research should replicate these findings using a larger sample. Either way, the findings show that highly automatic defense behavior can be influenced by relatively simple mental imagery manipulations.

  15. Improve Motor System Efficiency for a Broad Range of Motors with MotorMaster+ International

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-05-01

    Available at no charge, MotorMaster+ International is designed to support motor systems improvement planning at industrial facilities by identifying the most cost-effective choice when deciding to repair or replace older motor models.

  16. Classification of prefrontal activity due to mental arithmetic and music imagery using hidden Markov models and frequency domain near-infrared spectroscopy

    Science.gov (United States)

    Power, Sarah D.; Falk, Tiago H.; Chau, Tom

    2010-04-01

    Near-infrared spectroscopy (NIRS) has recently been investigated as a non-invasive brain-computer interface (BCI). In particular, previous research has shown that NIRS signals recorded from the motor cortex during left- and right-hand imagery can be distinguished, providing a basis for a two-choice NIRS-BCI. In this study, we investigated the feasibility of an alternative two-choice NIRS-BCI paradigm based on the classification of prefrontal activity due to two cognitive tasks, specifically mental arithmetic and music imagery. Deploying a dual-wavelength frequency domain near-infrared spectrometer, we interrogated nine sites around the frontopolar locations (International 10-20 System) while ten able-bodied adults performed mental arithmetic and music imagery within a synchronous shape-matching paradigm. With the 18 filtered AC signals, we created task- and subject-specific maximum likelihood classifiers using hidden Markov models. Mental arithmetic and music imagery were classified with an average accuracy of 77.2% ± 7.0 across participants, with all participants significantly exceeding chance accuracies. The results suggest the potential of a two-choice NIRS-BCI based on cognitive rather than motor tasks.

  17. BRST Quantization of String Theory in AdS(3)

    CERN Document Server

    Pakman, A

    2003-01-01

    We study the BRST quantization of bosonic and NSR strings propagating in AdS(3) x N backgrounds. The no-ghost theorem is proved using the Frenkel-Garland-Zuckerman method. Regular and spectrally-flowed representations of affine SL(2,R) appear on an equal footing. Possible generalizations to related curved backgrounds are discussed.

  18. Logarithmic AdS waves and Zwei-Dreibein gravity

    NARCIS (Netherlands)

    Bergshoeff, Eric A.; Goya, Andres F.; Merbis, Wout; Rosseel, Jan

    2014-01-01

    We show that the parameter space of Zwei-Dreibein Gravity (ZDG) in AdS(3) exhibits critical points, where massive graviton modes coincide with pure gauge modes and new 'logarithmic' modes appear, similar to what happens in New Massive Gravity. The existence of critical points is shown both at the li

  19. Internet Advertising. Google AdWords versus Facebook Ads

    Directory of Open Access Journals (Sweden)

    Paul PAŞCU

    2014-05-01

    Full Text Available This article describes how to use the applications for Internet advertising, Google AdWords and Facebook Ads. Our attempt is to present the advantages and disadvantages of each of them, the costs and benefits, a useful aspect for companies that plan to start advertising campaigns on the Internet.

  20. Penrose inequality for asymptotically AdS spaces

    Energy Technology Data Exchange (ETDEWEB)

    Itkin, Igor [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Oz, Yaron, E-mail: yaronoz@post.tau.ac.il [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel)

    2012-02-28

    In general relativity, the Penrose inequality relates the mass and the entropy associated with a gravitational background. If the inequality is violated by an initial Cauchy data, it suggests a creation of a naked singularity, thus providing means to consider the cosmic censorship hypothesis. We propose a general form of Penrose inequality for asymptotically locally AdS spaces.

  1. Internet Advertising. Google AdWords versus Facebook Ads

    OpenAIRE

    Paul PAŞCU

    2014-01-01

    This article describes how to use the applications for Internet advertising, Google AdWords and Facebook Ads. Our attempt is to present the advantages and disadvantages of each of them, the costs and benefits, a useful aspect for companies that plan to start advertising campaigns on the Internet.

  2. Predicting AD conversion: comparison between prodromal AD guidelines and computer assisted PredictAD tool.

    Directory of Open Access Journals (Sweden)

    Yawu Liu

    Full Text Available To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA on MRI and CSF biomarkers.Altogether 391 MCI cases (158 AD converters were selected from the ADNI cohort. All the cases had baseline cognitive tests, MRI and/or CSF levels of Aβ1-42 and Tau. Using baseline data, the status of MCI patients (AD or MCI three years later was predicted using current diagnostic research guidelines and the PredictAD software tool designed for supporting clinical diagnostics. The data used were 1 clinical criteria for episodic memory loss of the hippocampal type, 2 visual MTA, 3 positive CSF markers, 4 their combinations, and 5 when the PredictAD tool was applied, automatically computed MRI measures were used instead of the visual MTA results. The accuracies of diagnosis were evaluated with the diagnosis made 3 years later.The PredictAD tool achieved the overall accuracy of 72% (sensitivity 73%, specificity 71% in predicting the AD diagnosis. The corresponding number for a clinician's prediction with the assistance of the PredictAD tool was 71% (sensitivity 75%, specificity 68%. Diagnosis with the PredictAD tool was significantly better than diagnosis by biomarkers alone or the combinations of clinical diagnosis of hippocampal pattern for the memory loss and biomarkers (p≤0.037.With the assistance of PredictAD tool, the clinician can predict AD conversion more accurately than the current diagnostic criteria.

  3. Coset construction of AdS particle dynamics

    CERN Document Server

    Heinze, Martin; Megrelidze, Luka

    2016-01-01

    We analyze dynamics of the AdS$_{N+1}$ particle realized on the coset SO$(2,N)/$SO$(1,N)$. Hamiltonian reduction provides the physical phase space in terms of the coadjoint orbit obtained by boosting a timelike element of ${\\frak so}(2,N)$. We show equivalence of this approach to geometric quantization and to the SO$(N)$ covariant oscillator description, for which the boost generators entail a complicated operator ordering. As an alternative scheme, we introduce dual oscillator variables and derive their algebra at the classical and the quantum level. This simplifies the calculations of the commutators for the boost generators and leads to unitary irreducible representations of ${\\frak so}(2,N)$ for all admissible values of the mass parameter. We furthermore discuss a SO$(N)$ covariant supersymmetric extensions of the oscillator quantization, with its realization for superparticles in AdS$_2$ and AdS$_3$ given by recent works.

  4. Entanglement temperature and perturbed AdS3 geometry

    Science.gov (United States)

    Levine, G. C.; Caravan, B.

    2016-06-01

    Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .

  5. AdS5 backgrounds with 24 supersymmetries

    Science.gov (United States)

    Beck, S.; Gutowski, J.; Papadopoulos, G.

    2016-06-01

    We prove a non-existence theorem for smooth AdS 5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D = 11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS 5 × S 5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if gravitational duals for strictly mathcal{N}=3 superconformal theories in 4-dimensions exist, they are either singular or their internal spaces are not compact.

  6. AdS5 Backgrounds with 24 Supersymmetries

    CERN Document Server

    Beck, S W; Papadopoulos, G

    2016-01-01

    We prove a non-existence theorem for smooth AdS5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D=11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS_5 * S^5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if strictly N=3 superconformal theories in 4-dimensions exist, their gravitational dual backgrounds are either singular or their internal spaces are not compact.

  7. Use of ERTS-1 imagery in forest inventory

    Science.gov (United States)

    Rennie, J. C.; Birth, E. E.

    1974-01-01

    The utility of ERTS-1 imagery when combined with field observations and with aircraft imagery and field observations is evaluated. Satellite imagery consisted of 9-1/2 inch black and white negatives of four multispectral scanner bands taken over Polk County, Tennessee. Aircraft imagery was obtained by a C-130 flying at 23,000 ft over the same area and provided the basis for locating ground plots for field observations. Correspondence between aircraft and satellite imagery was somewhat inaccurate due to seasonal differences in observations and lack of good photogrammetry with the data processing system used. Better correspondence was found between satellite imagery and ground observations. Ways to obtain more accurate data are discussed, and comparisons between aircraft and satellite observations are tabulated.

  8. GATE: computation code for medical imagery, radiotherapy and dosimetry

    International Nuclear Information System (INIS)

    The author presents the GATE code, a simulation software based on the Geant4 development environment developed by the CERN (the European organization for nuclear research) which enables Monte-Carlo type simulation to be developed for tomography imagery using ionizing radiation, and radiotherapy examinations (conventional and hadron therapy) to be simulated. The authors concentrate on the use of medical imagery in carcinology. They comment some results obtained in nuclear imagery and in radiotherapy

  9. Alcohol imagery on popularly viewed television in the UK

    OpenAIRE

    Lyons, Ailsa; McNeill, Ann; Britton, John

    2013-01-01

    Background: Exposure to alcohol consumption and product imagery in films is associated with increased alcohol consumption among young people, but the extent to which exposure also occurs through television is not clear. We have measured the occurrence of alcohol imagery in prime-time broadcasting on UK free-to-air television channels. Methods: Occurrence of alcohol imagery (actual use, implied use, brand appearances or other reference to alcohol) was measured in all broadcasting on the fiv...

  10. Self-dual warped AdS3 black holes

    Science.gov (United States)

    Chen, Bin; Ning, Bo

    2010-12-01

    We study a new class of solutions of three-dimensional topological massive gravity. These solutions can be taken as nonextremal black holes, with their extremal counterparts being discrete quotients of spacelike warped AdS3 along the U(1)L isometry. We study the thermodynamics of these black holes and show that the first law is satisfied. We also show that for consistent boundary conditions, the asymptotic symmetry generators form only one copy of the Virasoro algebra with central charge cL=(4νℓ)/(G(ν2+3)), with which the Cardy formula reproduces the black hole entropy. We compute the real-time correlators of scalar perturbations and find a perfect match with the dual conformal field theory (CFT) predictions. Our study provides a novel example of warped AdS/CFT correspondence: the self-dual warped AdS3 black hole is dual to a CFT with nonvanishing left central charge. Moreover, our investigation suggests that the quantum topological massive gravity asymptotic to the same spacelike warped AdS3 in different consistent ways may be dual to different two-dimensional CFTs.

  11. Ultraviolet asymptotics for quasiperiodic AdS_4 perturbations

    CERN Document Server

    Craps, Ben; Jai-akson, Puttarak; Vanhoof, Joris

    2015-01-01

    Spherically symmetric perturbations in AdS-scalar field systems of small amplitude epsilon approximately periodic on time scales of order 1/epsilon^2 (in the sense that no significant transfer of energy between the AdS normal modes occurs) have played an important role in considerations of AdS stability. They are seen as anchors of stability islands where collapse of small perturbations to black holes does not occur. (This collapse, if it happens, typically develops on time scales of the order 1/epsilon^2.) We construct an analytic treatment of the frequency spectra of such quasiperiodic perturbations, paying special attention to the large frequency asymptotics. For the case of a self-interacting phi^4 scalar field in a non-dynamical AdS background, we arrive at a fairly complete analytic picture involving quasiperiodic spectra with an exponential suppression modulated by a power law at large mode numbers. For the case of dynamical gravity, the structure of the large frequency asymptotics is more complicated....

  12. System and method for motor parameter estimation

    Energy Technology Data Exchange (ETDEWEB)

    Luhrs, Bin; Yan, Ting

    2014-03-18

    A system and method for determining unknown values of certain motor parameters includes a motor input device connectable to an electric motor having associated therewith values for known motor parameters and an unknown value of at least one motor parameter. The motor input device includes a processing unit that receives a first input from the electric motor comprising values for the known motor parameters for the electric motor and receive a second input comprising motor data on a plurality of reference motors, including values for motor parameters corresponding to the known motor parameters of the electric motor and values for motor parameters corresponding to the at least one unknown motor parameter value of the electric motor. The processor determines the unknown value of the at least one motor parameter from the first input and the second input and determines a motor management strategy for the electric motor based thereon.

  13. Motor Vehicle Safety

    Science.gov (United States)

    ... these crashes is one part of motor vehicle safety. Here are some things you can do to ... speed or drive aggressively Don't drive impaired Safety also involves being aware of others. Share the ...

  14. Congenital Ocular Motor Apraxia

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-06-01

    Full Text Available The clinical and neuroradiological findings, and long-term intellectual prognosis in 10 patients (4 boys and 6 girls with congenital ocular motor apraxia (COMA are reviewed by researchers at Tottori University, Yonago, Japan.

  15. Partial motor status epilepticus

    OpenAIRE

    Gilberto Rebello de Mattos; José C. Rollemberg Filho

    1992-01-01

    We report the case of a young female patient with photosensitive primary epilepsy who presented partial motor status epilepticus provoked by the act of shutting the eyes. Clinical, EEG and neuroimage data are presented and discussed.

  16. Congenital Ocular Motor Apraxia

    OpenAIRE

    J Gordon Millichap

    2007-01-01

    The clinical and neuroradiological findings, and long-term intellectual prognosis in 10 patients (4 boys and 6 girls) with congenital ocular motor apraxia (COMA) are reviewed by researchers at Tottori University, Yonago, Japan.

  17. Nonautistic Motor Stereotypies

    OpenAIRE

    J Gordon Millichap

    2008-01-01

    Clinical features and long-term outcomes of 100 children (62 boys and 35 girls) with motor stereotypies were evaluated by review of records and telephone interviews at Johns Hopkins Hospital, Baltimore, MD.

  18. Heritability of motor control and motor learning

    OpenAIRE

    Missitzi, Julia; Gentner, Reinhard; Misitzi, Angelica; Geladas, Nickos; Politis, Panagiotis; Klissouras, Vassilis; Classen, Joseph

    2013-01-01

    Abstract The aim of this study was to elucidate the relative contribution of genes and environment on individual differences in motor control and acquisition of a force control task, in view of recent association studies showing that several candidate polymorphisms may have an effect on them. Forty‐four healthy female twins performed brisk isometric abductions with their right thumb. Force was recorded by a transducer and fed back to the subject on a computer screen. The task was to place the...

  19. LUNAR TERRAIN AND ALBEDO RECONSTRUCTION FROM APOLLO IMAGERY

    Data.gov (United States)

    National Aeronautics and Space Administration — LUNAR TERRAIN AND ALBEDO RECONSTRUCTION FROM APOLLO IMAGERY ARA V NEFIAN*, TAEMIN KIM, MICHAEL BROXTON, AND ZACH MORATTO Abstract. Generating accurate three...

  20. Development of motor control

    OpenAIRE

    Schellekens, Johannes Maria Hubertus

    1985-01-01

    In this thesis, the results of a series of investigations into the barrier function of human skin are presented. In these investigations, the barrier function was assessed by water vapour loss measurements of the skin using a method based on gradient estimation. The aim of this thesis is to study the role and efficiency of motor control and anticipation processes in the development of children with and without disturbances in the motor system. Chapter I is a general introduction to the subjec...