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Sample records for providing visual feedback

  1. Mobile in vivo camera robots provide sole visual feedback for abdominal exploration and cholecystectomy.

    Science.gov (United States)

    Rentschler, M E; Dumpert, J; Platt, S R; Ahmed, S I; Farritor, S M; Oleynikov, D

    2006-01-01

    The use of small incisions in laparoscopy reduces patient trauma, but also limits the surgeon's ability to view and touch the surgical environment directly. These limitations generally restrict the application of laparoscopy to procedures less complex than those performed during open surgery. Although current robot-assisted laparoscopy improves the surgeon's ability to manipulate and visualize the target organs, the instruments and cameras remain fundamentally constrained by the entry incisions. This limits tool tip orientation and optimal camera placement. The current work focuses on developing a new miniature mobile in vivo adjustable-focus camera robot to provide sole visual feedback to surgeons during laparoscopic surgery. A miniature mobile camera robot was inserted through a trocar into the insufflated abdominal cavity of an anesthetized pig. The mobile robot allowed the surgeon to explore the abdominal cavity remotely and view trocar and tool insertion and placement without entry incision constraints. The surgeon then performed a cholecystectomy using the robot camera alone for visual feedback. This successful trial has demonstrated that miniature in vivo mobile robots can provide surgeons with sufficient visual feedback to perform common procedures while reducing patient trauma.

  2. The effects of providing visual feedback and auditory stimulation using a robotic device on balance and gait abilities in persons with stroke: a pilot study

    National Research Council Canada - National Science Library

    Jae Ho Park; ; Yijung Chung

    2016-01-01

    Objective: The purpose of this study was to investigate the effects of providing visual feedback and auditory stimulation using a robotic device on balance and gait abilities in stroke patients. Design...

  3. Adaptation effects in static postural control by providing simultaneous visual feedback of center of pressure and center of gravity.

    Science.gov (United States)

    Takeda, Kenta; Mani, Hiroki; Hasegawa, Naoya; Sato, Yuki; Tanaka, Shintaro; Maejima, Hiroshi; Asaka, Tadayoshi

    2017-07-19

    The benefit of visual feedback of the center of pressure (COP) on quiet standing is still debatable. This study aimed to investigate the adaptation effects of visual feedback training using both the COP and center of gravity (COG) during quiet standing. Thirty-four healthy young adults were divided into three groups randomly (COP + COG, COP, and control groups). A force plate was used to calculate the coordinates of the COP in the anteroposterior (COPAP) and mediolateral (COPML) directions. A motion analysis system was used to calculate the coordinates of the center of mass (COM) in both directions (COMAP and COMML). The coordinates of the COG in the AP direction (COGAP) were obtained from the force plate signals. Augmented visual feedback was presented on a screen in the form of fluctuation circles in the vertical direction that moved upward as the COPAP and/or COGAP moved forward and vice versa. The COP + COG group received the real-time COPAP and COGAP feedback simultaneously, whereas the COP group received the real-time COPAP feedback only. The control group received no visual feedback. In the training session, the COP + COG group was required to maintain an even distance between the COPAP and COGAP and reduce the COGAP fluctuation, whereas the COP group was required to reduce the COPAP fluctuation while standing on a foam pad. In test sessions, participants were instructed to keep their standing posture as quiet as possible on the foam pad before (pre-session) and after (post-session) the training sessions. In the post-session, the velocity and root mean square of COMAP in the COP + COG group were lower than those in the control group. In addition, the absolute value of the sum of the COP - COM distances in the COP + COG group was lower than that in the COP group. Furthermore, positive correlations were found between the COMAP velocity and COP - COM parameters. The results suggest that the novel visual feedback training that

  4. Revisiting corrective saccades: role of visual feedback

    Science.gov (United States)

    Tian, Jing; Ying, Howard S.; Zee, David S.

    2013-01-01

    To clarify the role of visual feedback in the generation of corrective movements after inaccurate primary saccades, we used a visually-triggered saccade task in which we varied how long the target was visible. The target was on for only 100 ms (OFF100ms), on until the start of the primary saccade (OFFonset) or on for 2 s (ON). We found that the tolerance for the post-saccadic error was small (− 2%) with a visual signal (ON) but greater (−6%) without visual feedback (OFF100ms). Saccades with an error of −10%, however, were likely to be followed by corrective saccades regardless of whether or not visual feedback was present. Corrective saccades were generally generated earlier when visual error information was available; their latency was related to the size of the error. The LATER (Linear Approach to Threshold with Ergodic Rate) model analysis also showed a comparable small population of short latency corrective saccades irrespective of the target visibility. Finally, we found, in the absence of visual feedback, the accuracy of corrective saccades across subjects was related to the latency of the primary saccade. Our findings provide new insights into the mechanisms underlying the programming of corrective saccades: 1) the preparation of corrective saccades begins along with the preparation of the primary saccades, 2) the accuracy of corrective saccades depends on the reaction time of the primary saccades and 3) if visual feedback is available after the initiation of the primary saccade, the prepared correction can be updated. PMID:23891705

  5. Revisiting corrective saccades: role of visual feedback.

    Science.gov (United States)

    Tian, Jing; Ying, Howard S; Zee, David S

    2013-08-30

    To clarify the role of visual feedback in the generation of corrective movements after inaccurate primary saccades, we used a visually-triggered saccade task in which we varied how long the target was visible. The target was on for only 100ms (OFF100ms), on until the start of the primary saccade (OFFonset) or on for 2s (ON). We found that the tolerance for the post-saccadic error was small (-2%) with a visual signal (ON) but greater (-6%) without visual feedback (OFF100ms). Saccades with an error of -10%, however, were likely to be followed by corrective saccades regardless of whether or not visual feedback was present. Corrective saccades were generally generated earlier when visual error information was available; their latency was related to the size of the error. The LATER (Linear Approach to Threshold with Ergodic Rate) model analysis also showed a comparable small population of short latency corrective saccades irrespective of the target visibility. Finally, we found, in the absence of visual feedback, the accuracy of corrective saccades across subjects was related to the latency of the primary saccade. Our findings provide new insights into the mechanisms underlying the programming of corrective saccades: (1) the preparation of corrective saccades begins along with the preparation of the primary saccades, (2) the accuracy of corrective saccades depends on the reaction time of the primary saccades and (3) if visual feedback is available after the initiation of the primary saccade, the prepared correction can be updated. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Providing Feedback: Practical Skills and Strategies.

    Science.gov (United States)

    Sarkany, David; Deitte, Lori

    2017-06-01

    Feedback is an essential component of education. It is designed to influence, reinforce, and change behaviors, concepts, and attitudes in learners. Although providing constructive feedback can be challenging, it is a learnable skill. The negative consequences of destructive feedback or lack of feedback all together are far-reaching. This article summarizes the components of constructive feedback and provides readers with tangible skills to enhance their ability to give effective feedback to learners and peers. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  7. Haptic Feedback Compared with Visual Feedback for BCI

    OpenAIRE

    Kauhanen, L.; Palomäki, T; Jylänki, P.; Aloise, F; Nuttin, Marnix; Millán, José del R.

    2006-01-01

    Feedback plays an important role when learning to use a Brain-Computer Interface (BCI). Here we compare visual and haptic feedback in a short experiment. By imagining left and right hand movements, six subjects tried to control a BCI with the help of either visual or haptic feedback every 1s. Alpha band EEG signals from C3 and C4 were classified. The classifier was updated after each prediction using correct class information. Thus feedback could be given throughout the experiment. Subjects g...

  8. The influence of force feedback and visual feedback in grasping tissue laparoscopically

    NARCIS (Netherlands)

    Heijnsdijk, E. A. M.; Pasdeloup, A.; van der Pijl, A. J.; Dankelman, J.; Gouma, D. J.

    2004-01-01

    Background: Due to the limited force feedback provided by laparoscopic instruments, surgeons may have difficulty in applying the appropriate force on the tissue. The aim of this study was to determine the influence of force feedback and visual feedback on the exerted pinch force. Methods: A grasper

  9. Revisiting corrective saccades: Role of visual feedback

    OpenAIRE

    Tian, Jing; Ying, Howard S.; Zee, David S.

    2013-01-01

    To clarify the role of visual feedback in the generation of corrective movements after inaccurate primary saccades, we used a visually-triggered saccade task in which we varied how long the target was visible. The target was on for only 100 ms (OFF100ms), on until the start of the primary saccade (OFFonset) or on for 2 s (ON). We found that the tolerance for the post-saccadic error was small (− 2%) with a visual signal (ON) but greater (−6%) without visual feedback (OFF100ms). Saccades with a...

  10. The influence of force feedback and visual feedback in grasping tissue laparoscopically.

    Science.gov (United States)

    Heijnsdijk, E A M; Pasdeloup, A; van der Pijl, A J; Dankelman, J; Gouma, D J

    2004-06-01

    Due to the limited force feedback provided by laparoscopic instruments, surgeons may have difficulty in applying the appropriate force on the tissue. The aim of this study was to determine the influence of force feedback and visual feedback on the exerted pinch force. A grasper with a force sensor in the jaws was developed. Subjects with and without laparoscopic experience grasped and pulled pig bowel with a force of 5 N. The applied pinch force was measured during tasks of 1-s and 1-min duration. Visual feedback was provided in half the measurements. Force feedback was adjusted by changing the mechanical efficiency of the forceps from 30% to 90%. The mean pinch force applied was 6.8 N (+/-0.5), whereas the force to prevent slippage was 3.0 N (+/-0.4). Improving the mechanical efficiency had no effect on the pinch force for the 1-s measurements. The amount of excessive pinch force when holding tissue for 1 min was lower at 30% mechanical efficiency compared with 90% (105% vs 131%, p = 0.04). The tissue slipped more often when the subject had no visual feedback (2% vs 8%, p = 0.02). Force feedback and visual feedback play a more limited role than expected in the task of grasping tissue with laparoscopic forceps.

  11. Efficient visual recalibration from either visual or haptic feedback: the importance of being wrong.

    Science.gov (United States)

    Adams, Wendy J; Kerrigan, Iona S; Graf, Erich W

    2010-11-03

    The human visual system adapts to the changing statistics of its environment. For example, the light-from-above prior, an assumption that aids the interpretation of ambiguous shading information, can be modified by haptic (touch) feedback. Here we investigate the mechanisms that drive this adaptive learning. In particular, we ask whether visual information can be as effective as haptics in driving visual recalibration and whether increased information (feedback from multiple modalities) induces faster learning. During several hours' training, feedback encouraged observers to modify their existing light-from-above assumption. Feedback was one of the following: (1) haptic only, (2) haptic and stereoscopic (providing binocular shape information), or (3) stereoscopic only. Haptic-only feedback resulted in substantial learning; the perceived shape of shaded objects was modified in accordance with observers' new light priors. However, the addition of continuous visual feedback (condition 2) substantially reduced learning. When visual-only feedback was provided intermittently (condition 3), mimicking the time course of the haptic feedback of conditions 1 and 2, substantial learning returned. The intermittent nature of conflict information, or feedback, appears critical for learning. It causes an initial, erroneous percept to be corrected. Contrary to previous proposals, we found no particular advantage for cross-modal feedback. Instead, we suggest that an "oops" factor drives efficient learning; recalibration is prioritized when a mismatch exists between sequential representations of an object property. This "oops" factor appears important both across and within sensory modalities, suggesting a general principle for perceptual learning and recalibration.

  12. Enhanced visual feedback for slip prevention with a prosthetic hand.

    Science.gov (United States)

    Engeberg, Erik D; Meek, Sanford

    2012-12-01

    Upper limb amputees have no direct sense of the grip force applied by a prosthetic hand; thus, precise control of the applied grip force is difficult for amputees. Since there is little object deformation when rigid objects are grasped, it is difficult for amputees to visually gauge the applied grip force in this situation. To determine if the applied grip force from a prosthetic hand can be visually displayed and used to more efficaciously grasp objects. Experimental controlled trial. Force feedback is used in the control algorithm for the prosthetic hand and supplied visually to the user through a bicolor LED experimentally mounted to the thumb. Several experiments are performed by able-bodied test subjects to rate the usefulness of the additional visual feedback when manipulating a clearly visible, brittle object that can break if grasped too firmly. A hybrid force-velocity sliding mode controller is used with and without additional visual force feedback supplied to the operators. Subjective evaluations and success rates from the test subjects indicate a statistically significant reduction in breaking the grasped object when using the prosthesis with the extra visual feedback. The additional visual force feedback can effectively facilitate the manipulation of brittle objects. Clinical relevance The novel approach of this research is the implementation of a noninvasive, effective and economic technique to visually indicate the grip force applied by a prosthetic hand to upper limb amputees. This technique provides a statistically significant improvement when handling brittle objects.

  13. Differential effects of visual feedback on subjective visual vertical accuracy and precision.

    Directory of Open Access Journals (Sweden)

    Daniel Bjasch

    Full Text Available The brain constructs an internal estimate of the gravitational vertical by integrating multiple sensory signals. In darkness, systematic head-roll dependent errors in verticality estimates, as measured by the subjective visual vertical (SVV, occur. We hypothesized that visual feedback after each trial results in increased accuracy, as physiological adjustment errors (A-/E-effect are likely based on central computational mechanisms and investigated whether such improvements were related to adaptational shifts of perceived vertical or to a higher cognitive strategy. We asked 12 healthy human subjects to adjust a luminous arrow to vertical in various head-roll positions (0 to 120deg right-ear down, 15deg steps. After each adjustment visual feedback was provided (lights on, display of previous adjustment and of an earth-vertical cross. Control trials consisted of SVV adjustments without feedback. At head-roll angles with the largest A-effect (90, 105, and 120deg, errors were reduced significantly (p0.05 influenced. In seven subjects an additional session with two consecutive blocks (first with, then without visual feedback was completed at 90, 105 and 120deg head-roll. In these positions the error-reduction by the previous visual feedback block remained significant over the consecutive 18-24 min (post-feedback block, i.e., was still significantly (p<0.002 different from the control trials. Eleven out of 12 subjects reported having consciously added a bias to their perceived vertical based on visual feedback in order to minimize errors. We conclude that improvements of SVV accuracy by visual feedback, which remained effective after removal of feedback for ≥18 min, rather resulted from a cognitive strategy than by adapting the internal estimate of the gravitational vertical. The mechanisms behind the SVV therefore, remained stable, which is also supported by the fact that SVV precision - depending mostly on otolith input - was not affected by visual

  14. Adding vibrotactile feedback to a myoelectric-controlled hand improves performance when online visual feedback is disturbed.

    Science.gov (United States)

    Raveh, Eitan; Portnoy, Sigal; Friedman, Jason

    2018-01-17

    We investigated whether adding vibrotactile feedback to a myoelectric-controlled hand, when visual feedback is disturbed, can improve performance during a functional test. For this purpose, able-bodied subjects, activating a myoelectric-controlled hand attached to their right hand performed the modified Box & Blocks test, grasping and manipulating wooden blocks over a partition. This was performed in 3 conditions, using a repeated-measures design: in full light, in a dark room where visual feedback was disturbed and no auditory feedback - one time with the addition of tactile feedback provided during object grasping and manipulation, and one time without any tactile feedback. The average time needed to transfer one block was measured, and an infrared camera was used to give information on the number of grasping errors during performance of the test. Our results show that when vibrotactile feedback was provided, performance time was reduced significantly, compared with when no vibrotactile feedback was available. Furthermore, the accuracy of grasping and manipulation was improved, reflected by significantly fewer errors during test performance. In conclusion, adding vibrotactile feedback to a myoelectric-controlled hand has positive effects on functional performance when visual feedback is disturbed. This may have applications to current myoelectric-controlled hands, as adding tactile feedback may help prosthesis users to improve their functional ability during daily life activities in different environments, particularly when limited visual feedback is available or desirable. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Providing Effective Feedback to EFL Student Teachers

    Science.gov (United States)

    Ali, Holi Ibrahim Holi; Al-Adawi, Hamed Ahmed

    2013-01-01

    Feedback on school practicum is of utmost importance for student teachers to help them to develop their pedagogical and teaching skills. This paper attempts to collect data from both student teachers and their mentors in an ELT teacher training programme in Oman to answer the questions which are raised by this study: 1) What kind of feedback do…

  16. The Effects of Visual Feedback Distortion with Unilateral Leg Loading on Gait Symmetry.

    Science.gov (United States)

    Tobar, Carlos; Martinez, Eva; Rhouni, Nada; Kim, Seung-Jae

    2018-02-01

    Our prior work provides evidence that visual feedback distortion drives an implicit adaptation; a gradual distortion of visual representation of step length modulated subjects' step lengths away from symmetry. To further explore the effect of the visual feedback distortion on unconscious change in step symmetry, we investigated whether such adaptation would occur even in the presence of altered limb mechanics by adding mass to one side of the leg. 26 subjects performed three 8-min trials (weight only, weight plus visual feedback, and weight plus visual feedback distortion) of treadmill walking. During the weight only trial, the subjects wore a 5 lb mass around the right ankle. The modification of limb inertia caused asymmetric gait. The visual feedback showing right and left step length information as bar graphs was displayed on a computer screen. To add visual feedback distortion, we increased the length of one side of the visual bars by 10% above the actual step length, and the visual distortion was implemented for the side that took longer in response to the added mass. We found that even when adjustments were made to unilateral loading, the subjects spontaneously changed their step symmetry in response to the visual distortion, which resulted in a more symmetric gait. This change may be characterized by sensory prediction errors, and our results suggest that visual feedback distortion has a significant impact on gait symmetry regardless of other conditions affecting limb mechanics. A rehabilitation program employing visual feedback distortion may provide an effective way to restore gait symmetry.

  17. Trans-Tibial Amputee Gait Correction through Real-Time Visual Feedback

    OpenAIRE

    Seyyed Farhad Tabatabi Ghomshe; Reza Osqueizadeh; Seyyedeh Hoda Nabavi

    2016-01-01

    Objective: The present paper reports on program of work undertaken to evaluate the effect of real time visual feedback on kinematics of prosthetic gait. Methods: A total of 6 below-knee male amputees were included in the study. Each individual underwent three trials of self-selected speed treadmill walking, in which real time visual feedback was provided from forward, backward, and lateral views, together with a control trial without any visual feedback. Kinematic reference values were ca...

  18. Reach adaptation and proprioceptive recalibration following terminal visual feedback of the hand

    Directory of Open Access Journals (Sweden)

    Victoria eBarkley

    2014-09-01

    Full Text Available We have shown that when subjects reach with continuous, misaligned visual feedback of their hand, their reaches are adapted and proprioceptive sense of hand position is recalibrated to partially match the visual feedback (Salomonczyk et al., 2011. It is unclear if similar changes arise after reaching with visual feedback that is provided only at the end of the reach (i.e., terminal feedback, when there are shorter temporal intervals for subjects to experience concurrent visual and proprioceptive feedback. Subjects reached to targets with an aligned hand-cursor that provided visual feedback at the end of each reach movement across a 99-trial training block, and with a rotated cursor over 3 successive blocks of 99 trials each. After each block, no cursor reaches, to measure aftereffects, and felt hand positions were measured. Felt hand position was determined by having subjects indicate the position of their unseen hand relative to a reference marker. We found that subjects adapted their reaches following training with rotated terminal visual feedback, yet slightly less (i.e., reach aftereffects were smaller, than subjects from a previous study who experienced continuous visual feedback. Nonetheless, current subjects recalibrated their sense of felt hand position in the direction of the altered visual feedback, but this proprioceptive change increased incrementally over the three rotated training blocks. Final proprioceptive recalibration levels were comparable to our previous studies in which subjects performed the same task with continuous visual feedback. Thus, compared to reach training with continuous, but altered visual feedback, subjects who received terminal altered visual feedback of the hand produced significant but smaller reach aftereffects and similar changes in hand proprioception when given extra training. Taken together, results suggest that terminal feedback of the hand is sufficient to drive motor adaptation, and also

  19. Reach adaptation and proprioceptive recalibration following terminal visual feedback of the hand

    Science.gov (United States)

    Barkley, Victoria; Salomonczyk, Danielle; Cressman, Erin K.; Henriques, Denise Y. P.

    2014-01-01

    We have shown that when subjects reach with continuous, misaligned visual feedback of their hand, their reaches are adapted and proprioceptive sense of hand position is recalibrated to partially match the visual feedback (Salomonczyk et al., 2011). It is unclear if similar changes arise after reaching with visual feedback that is provided only at the end of the reach (i.e., terminal feedback), when there are shorter temporal intervals for subjects to experience concurrent visual and proprioceptive feedback. Subjects reached to targets with an aligned hand-cursor that provided visual feedback at the end of each reach movement across a 99-trial training block, and with a rotated cursor over three successive blocks of 99 trials each. After each block, no cursor reaches, to measure aftereffects, and felt hand positions were measured. Felt hand position was determined by having subjects indicate the position of their unseen hand relative to a reference marker. We found that subjects adapted their reaches following training with rotated terminal visual feedback, yet slightly less (i.e., reach aftereffects were smaller), than subjects from a previous study who experienced continuous visual feedback. Nonetheless, current subjects recalibrated their sense of felt hand position in the direction of the altered visual feedback, but this proprioceptive change increased incrementally over the three rotated training blocks. Final proprioceptive recalibration levels were comparable to our previous studies in which subjects performed the same task with continuous visual feedback. Thus, compared to reach training with continuous, but altered visual feedback, subjects who received terminal altered visual feedback of the hand produced significant but smaller reach aftereffects and similar changes in hand proprioception when given extra training. Taken together, results suggest that terminal feedback of the hand is sufficient to drive motor adaptation, and also proprioceptive

  20. Self-Evaluation and Recruitment of Feedback for Enhanced Social Interaction by a Student with Visual Impairment

    Science.gov (United States)

    Jindal-Snape, Divya

    2005-01-01

    A student who is visually impaired was trained to evaluate his social behavior and to recruit feedback from his sighted peers, who were trained by him to provide the feedback. The self-recruitment of feedback improved the student's accuracy in evaluating social skills requiring visual cues. In addition, the peers extended their feedback to other…

  1. The role of visual feedback in supervision of grammatical spelling.

    Science.gov (United States)

    Veys, Emilie; Hupet, Michel

    2011-06-01

    Native French speakers (N = 24; M age = 20.1 yr.) were orally presented with sentences they were asked to write on a digitizing tablet, either with full visual feedback or with no visual feedback. The study assessed the extent to which the visual feedback contributed to supervising of verbal agreement processes, either postgraphically (detecting and revising any error that has been produced) or pregraphically (checking the graphemic plan before it is transcribed). The proportion of erroneous agreements was smaller with visual feedback (7%) than without (14%). The proportion of erroneous agreements that were spontaneously corrected was much higher with visual feedback (34%) than without (0%). There were significantly more pauses right before or within the transcription of the verbal inflection with visual feedback (8%) than without (3%).

  2. Learning expressive percussion performance under different visual feedback conditions

    OpenAIRE

    Brandmeyer, A.; Timmers, R.; Sadakata, M.; Desain, P.

    2010-01-01

    A study was conducted to test the effect of two different forms of real-time visual feedback on expressive percussion performance. Conservatory percussion students performed imitations of recorded teacher performances while receiving either high-level feedback on the expressive style of their performances, low-level feedback on the timing and dynamics of the performed notes, or no feedback. The high-level feedback was based on a Bayesian analysis of the performances, while the low-level feedb...

  3. Augmented visual feedback-aided interventions for motor rehabilitation in Parkinson's disease: a systematic review.

    Science.gov (United States)

    Kearney, Elaine; Shellikeri, Sanjana; Martino, Rosemary; Yunusova, Yana

    2018-01-09

    A systematic review was performed to (1) evaluate the effectiveness of augmented visual feedback-based treatments for motor rehabilitation in Parkinson's disease, and (2) examine treatment design factors associated with enhanced outcomes following these treatments. Eight databases were searched from their start-date up to January 2017 using the key terms Parkinson's Disease and augmented visual feedback. Two independent raters screened the abstracts and full articles for inclusion. Relevant data were extracted and summarized, and methodological quality of accepted articles was assessed. Eight single-group studies and 10 randomized control trials were included in the review. Augmented visual feedback-based treatments resulted in improved outcomes with small to large effect sizes post-treatment for the majority of impairment, activity, participation, and global motor function measures, and these improvements were often superior to traditional rehabilitation/education programs. Enhanced treatment outcomes were observed in studies that provided large amounts and high intensities of treatment; gamified feedback; and provided knowledge of performance feedback in real-time on 100% of practice trials. Augmented visual feedback appears to be a useful motor rehabilitation tool in Parkinson's disease; however, high-quality, rigorous studies remain limited. Future studies should consider factors that enhance rehabilitation outcomes when designing augmented visual feedback-based interventions. Implications for rehabilitation Augmented visual feedback is a useful tool for motor rehabilitation in Parkinson's disease; augmented visual feedback-based treatments are often superior to traditional programs. These treatments are associated with improved outcomes in impairment, activity, participation, and global motor function domains. Rehabilitation professionals can optimize their use of augmented visual feedback-based treatments by providing large amounts and a high intensity of

  4. OpinionSeer: interactive visualization of hotel customer feedback.

    Science.gov (United States)

    Wu, Yingcai; Wei, Furu; Liu, Shixia; Au, Norman; Cui, Weiwei; Zhou, Hong; Qu, Huamin

    2010-01-01

    The rapid development of Web technology has resulted in an increasing number of hotel customers sharing their opinions on the hotel services. Effective visual analysis of online customer opinions is needed, as it has a significant impact on building a successful business. In this paper, we present OpinionSeer, an interactive visualization system that could visually analyze a large collection of online hotel customer reviews. The system is built on a new visualization-centric opinion mining technique that considers uncertainty for faithfully modeling and analyzing customer opinions. A new visual representation is developed to convey customer opinions by augmenting well-established scatterplots and radial visualization. To provide multiple-level exploration, we introduce subjective logic to handle and organize subjective opinions with degrees of uncertainty. Several case studies illustrate the effectiveness and usefulness of OpinionSeer on analyzing relationships among multiple data dimensions and comparing opinions of different groups. Aside from data on hotel customer feedback, OpinionSeer could also be applied to visually analyze customer opinions on other products or services.

  5. Feedback in Clinical Education, Part I: Characteristics of Feedback Provided by Approved Clinical Instructors

    Science.gov (United States)

    Nottingham, Sara; Henning, Jolene

    2014-01-01

    Context Providing students with feedback is an important component of athletic training clinical education; however, little information is known about the feedback that Approved Clinical Instructors (ACIs; now known as preceptors) currently provide to athletic training students (ATSs). Objective To characterize the feedback provided by ACIs to ATSs during clinical education experiences. Design Qualitative study. Setting One National Collegiate Athletic Association Division I athletic training facility and 1 outpatient rehabilitation clinic that were clinical sites for 1 entry-level master's degree program accredited by the Commission on Accreditation of Athletic Training Education. Patients or Other Participants A total of 4 ACIs with various experience levels and 4 second-year ATSs. Data Collection and Analysis Extensive field observations were audio recorded, transcribed, and integrated with field notes for analysis. The constant comparative approach of open, axial, and selective coding was used to inductively analyze data and develop codes and categories. Member checking, triangulation, and peer debriefing were used to promote trustworthiness of the study. Results The ACIs gave 88 feedback statements in 45 hours and 10 minutes of observation. Characteristics of feedback categories included purpose, timing, specificity, content, form, and privacy. Conclusions Feedback that ACIs provided included several components that made each feedback exchange unique. The ACIs in our study provided feedback that is supported by the literature, suggesting that ACIs are using current recommendations for providing feedback. Feedback needs to be investigated across multiple athletic training education programs to gain more understanding of certain areas of feedback, including frequency, privacy, and form. PMID:24143902

  6. Using Turnitin to Provide Feedback on L2 Writers' Texts

    Science.gov (United States)

    Kostka, Ilka; Maliborska, Veronika

    2016-01-01

    Second language (L2) writing instructors have varying tools at their disposal for providing feedback on students' writing, including ones that enable them to provide written and audio feedback in electronic form. One tool that has been underexplored is Turnitin, a widely used software program that matches electronic text to a wide range of…

  7. Guideline implementation in clinical practice: Use of statistical process control charts as visual feedback devices

    Directory of Open Access Journals (Sweden)

    Fahad A Al-Hussein

    2009-01-01

    Conclusions: A process of audits in the context of statistical process control is necessary for any improvement in the implementation of guidelines in primary care. Statistical process control charts are an effective means of visual feedback to the care providers.

  8. Learning expressive percussion performance under different visual feedback conditions

    NARCIS (Netherlands)

    Brandmeyer, A.; Timmers, R.; Sadakata, M.; Desain, P.W.M.

    2011-01-01

    A study was conducted to test the effect of two different forms of real-time visual feedback on expressive percussion performance. Conservatory percussion students performed imitations of recorded teacher performances while receiving either high-level feedback on the expressive style of their

  9. A feedback model of visual attention

    OpenAIRE

    Spratling, M. W.; Johnson, M H

    2004-01-01

    Feedback connections are a prominent feature of cortical anatomy and are likely to have a significant functional role in neural information processing. We present a neural network model of cortical feedback that successfully simulates neurophysiological data associated with attention. In this domain, our model can be considered a more detailed, and biologically plausible, implementation of the biased competition model of attention. However, our model is more general as it can also explain a v...

  10. The Effect of Concurrent Visual Feedback on Controlling Swimming Speed

    Directory of Open Access Journals (Sweden)

    Szczepan Stefan

    2016-03-01

    Full Text Available Introduction. Developing the ability to control the speed of swimming is an important part of swimming training. Maintaining a defined constant speed makes it possible for the athlete to swim economically at a low physiological cost. The aim of this study was to determine the effect of concurrent visual feedback transmitted by the Leader device on the control of swimming speed in a single exercise test. Material and methods. The study involved a group of expert swimmers (n = 20. Prior to the experiment, the race time for the 100 m distance was determined for each of the participants. In the experiment, the participants swam the distance of 100 m without feedback and with visual feedback. In both variants, the task of the participants was to swim the test distance in a time as close as possible to the time designated prior to the experiment. In the first version of the experiment (without feedback, the participants swam the test distance without receiving real-time feedback on their swimming speed. In the second version (with visual feedback, the participants followed a beam of light moving across the bottom of the swimming pool, generated by the Leader device. Results. During swimming with visual feedback, the 100 m race time was significantly closer to the time designated. The difference between the pre-determined time and the time obtained was significantly statistically lower during swimming with visual feedback (p = 0.00002. Conclusions. Concurrently transmitting visual feedback to athletes improves their control of swimming speed. The Leader device has proven useful in controlling swimming speed.

  11. Learning expressive percussion performance under different visual feedback conditions.

    Science.gov (United States)

    Brandmeyer, Alex; Timmers, Renee; Sadakata, Makiko; Desain, Peter

    2011-03-01

    A study was conducted to test the effect of two different forms of real-time visual feedback on expressive percussion performance. Conservatory percussion students performed imitations of recorded teacher performances while receiving either high-level feedback on the expressive style of their performances, low-level feedback on the timing and dynamics of the performed notes, or no feedback. The high-level feedback was based on a Bayesian analysis of the performances, while the low-level feedback was based on the raw participant timing and dynamics data. Results indicated that neither form of feedback led to significantly smaller timing and dynamics errors. However, high-level feedback did lead to a higher proficiency in imitating the expressive style of the target performances, as indicated by a probabilistic measure of expressive style. We conclude that, while potentially disruptive to timing processes involved in music performance due to extraneous cognitive load, high-level visual feedback can improve participant imitations of expressive performance features.

  12. The Effect of Performance Feedback Provided to Student-Teachers Working with Multiple Disabilities

    Science.gov (United States)

    Safak, Pinar; Yilmaz, Hatice Cansu; Demiryurek, Pinar; Dogus, Mustafa

    2016-01-01

    The aim of the study was to investigate the effect of performance feedback (PF) provided to student teachers working with students with multiple disabilities and visual impairment (MDVI) on their teaching skills. The study group of the research was composed of 11 student teachers attending to the final year of the Teaching Students with Visual…

  13. Feedback providing improvement strategies and reflection on feedback use: Effects on students' writing motivation, process, and performance

    NARCIS (Netherlands)

    Duijnhouwer, H.; Prins, F.J.; Stokking, K.M.

    2012-01-01

    This study investigated the effects of feedback providing improvement strategies and a reflection assignment on students’ writing motivation, process, and performance. Students in the experimental feedback condition (n = 41) received feedback including improvement strategies, whereas students in the

  14. Visual feedback for retuning to just intonation intervals

    Science.gov (United States)

    Ayers, R. Dean; Nordquist, Peter R.; Corn, Justin S.

    2005-04-01

    Musicians become used to equal temperament pitch intervals due to their widespread use in tuning pianos and other fixed-pitch instruments. For unaccompanied singing and some other performance situations, a more harmonious blending of sounds can be achieved by shifting to just intonation intervals. Lissajous figures provide immediate and striking visual feedback that emphasizes the frequency ratios and pitch intervals found among the first few members of a single harmonic series. Spirograph patterns (hypotrochoids) are also especially simple for ratios of small whole numbers, and their use for providing feedback to singers has been suggested previously [G. W. Barton, Jr., Am. J. Phys. 44(6), 593-594 (1976)]. A hybrid mixture of these methods for comparing two frequencies generates what appears to be a three dimensional Lissajous figure-a cylindrical wire mesh that rotates about its tilted vertical axis, with zero tilt yielding the familiar Lissajous figure. Sine wave inputs work best, but the sounds of flute, recorder, whistling, and a sung ``oo'' are good enough approximations to work well. This initial study compares the three modes of presentation in terms of the ease with which a singer can obtain a desired pattern and recognize its shape.

  15. Eye movement feedback fails to improve visual search performance.

    Science.gov (United States)

    Peltier, Chad; Becker, Mark W

    2017-01-01

    Many real-world searches (e.g., radiology and baggage screening) have rare targets. When targets are rare, observers perform rapid, incomplete searches, leading to higher miss rates. To improve search for rare (10% prevalence) targets, we provided eye movement feedback (EMF) to observers during their searches. Although the nature of the EMF varied across experiments, each method informed observers about the regions of the display that had not yet been inspected. We hypothesized that feedback would help guide attention to unsearched areas and increase the proportion of the display searched before making a target-absent response, thereby increasing accuracy. An eye tracker was used to mark fixated areas by either removing a semiopaque gray overlay (Experiments 1 and 4) as portions of the display were fixated or by adding the overlay once the eye left a segment of the image (Experiments 2 and 4). Experiment 3 provided automated EMF, such that a new region was uncovered every 540 milliseconds. Across experiments, we varied whether people searched for "Waldo" in images from "Where's Waldo?" search books or searched for a T among offset Ls. We found weak evidence that EMF improves accuracy in Experiment 1. However, in the remaining experiments, EMF had no effect (Experiment 4), or even reduced accuracy (Experiments 2 and 3). We conclude that the one positive result we found is likely a Type I error and that the EMF method that we used is unlikely to improve visual search performance.

  16. Haptic and Visual feedback in 3D Audio Mixing Interfaces

    DEFF Research Database (Denmark)

    Gelineck, Steven; Overholt, Daniel

    2015-01-01

    This paper describes the implementation and informal evaluation of a user interface that explores haptic feedback for 3D audio mixing. The implementation compares different approaches using either the LEAP Motion for mid-air hand gesture control, or the Novint Falcon for active haptic feed- back...... in order to augment the perception of the 3D space. We compare different interaction paradigms implemented using these interfaces, aiming to increase speed and accuracy and reduce the need for constant visual feedback. While the LEAP Motion relies upon visual perception and proprioception, users can forego...

  17. Providing Rapid Feedback in Generated Modular Language Environments

    NARCIS (Netherlands)

    Kats, L.C.L.; De Jonge, M.; Nilsson-Nyman, E.; Visser, E.

    2009-01-01

    This paper is a pre-print of: Providing Rapid Feedback in Generated Modular Language Environments. Adding Error Recovery to Scannerless Generalized-LR Parsing. In: Gary T. Leavens, editor, Proceedings of the 24th ACM SIGPLAN Conference on Object-Oriented Programing, Systems, Languages, and

  18. A method for calculating active feedback system to provide vertical ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 68; Issue 4. A method for calculating active feedback system to provide vertical position control of plasma in a tokamak. Nizami Gasilov. Research ... Nizami Gasilov1. Faculty of Engineering, Baskent University, Eskisehir Yolu 20. km, Baglica, 06530 Ankara, Turkey ...

  19. 5 CFR 9701.407 - Monitoring performance and providing feedback.

    Science.gov (United States)

    2010-01-01

    ... implementing directives and policies, supervisors must— (a) Monitor the performance of their employees and the organization; and (b) Provide timely periodic feedback to employees on their actual performance with respect to their performance expectations, including one or more interim performance reviews during each appraisal...

  20. Enhancing Healthcare Provider Feedback and Personal Health Literacy

    DEFF Research Database (Denmark)

    Kaltoft, Mette Kjer; Nielsen, Jesper Bo; Salkeld, Glenn

    2015-01-01

    In this protocol for a pilot study we seek to establish the feasibility of using a web-based survey to simultaneously supply healthcare organisations and agencies with feedback on a key aspect of the care experience they provide and increase the generic health decision literacy of the individuals...

  1. The role of visual and direct force feedback in robotics-assisted mitral valve annuloplasty.

    Science.gov (United States)

    Currie, Maria E; Talasaz, Ali; Rayman, Reiza; Chu, Michael W A; Kiaii, Bob; Peters, Terry; Trejos, Ana Luisa; Patel, Rajni

    2017-09-01

    The objective of this work was to determine the effect of both direct force feedback and visual force feedback on the amount of force applied to mitral valve tissue during ex vivo robotics-assisted mitral valve annuloplasty. A force feedback-enabled master-slave surgical system was developed to provide both visual and direct force feedback during robotics-assisted cardiac surgery. This system measured the amount of force applied by novice and expert surgeons to cardiac tissue during ex vivo mitral valve annuloplasty repair. The addition of visual (2.16 ± 1.67), direct (1.62 ± 0.86), or both visual and direct force feedback (2.15 ± 1.08) resulted in lower mean maximum force applied to mitral valve tissue while suturing compared with no force feedback (3.34 ± 1.93 N; P forces on cardiac tissue during robotics-assisted mitral valve annuloplasty suturing, force feedback may be required. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Use of visual CO2 feedback as a retrofit solution for improving classroom air quality

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Da Silva, Nuno Alexandre Faria

    2015-01-01

    Carbon dioxide (CO2) sensors that provide a visual indication were installed in classrooms during normal school operation. During 2-week periods, teachers and students were instructed to open the windows in response to the visual CO2 feedback in 1week and open them, as they would normally do...... and the other pair with no cooling. Classrooms were matched by grade. Providing visual CO2 feedback reduced CO2 levels, as more windows were opened in this condition. This increased energy use for heating and reduced the cooling requirement in summertime. Split cooling reduced the frequency of window opening...... only when no visual CO2 feedback was present....

  3. Three Principles for the Design of Energy Feedback Visualizations

    DEFF Research Database (Denmark)

    Brewer, Robert S.; Xu, Yongwen; Lee, George E.

    2013-01-01

    To achieve the full benefits of the Smart Grid, end users must become active participants in the energy ecosystem. This paper presents the Kukui Cup challenge, a multifaceted serious game designed around the topic of energy conservation that incorporates a variety of energy feedback visualizations...

  4. Effects of visual feedback on manipulation performance and patient ratings.

    Science.gov (United States)

    Triano, John J; Scaringe, John; Bougie, Jacqueline; Rogers, Carolyn

    2006-06-01

    This study examined the explicit targeted outcome (a criterion standard) and visual feedback on the immediate change in and the short-term retention of performance by novice operators for a high-velocity, low-amplitude procedure under realistic conditions. This study used a single-blind randomized experimental design. Forty healthy male (n = 26) and female (n = 14) chiropractic student volunteers with no formal training in spinal manipulative therapy participated. Biomechanical parameters of an L4 mammillary push spinal manipulation procedure performed by novice operators were quantified. Participants were randomly assigned to 2 groups and paired. One group received visual feedback from load-time histories of their performance compared with a criterion standard before a repeat performance. Participants then performed a 10-minute distractive exercise consisting of National Board of Chiropractic Examiners review questions. The second group received no feedback. An independent rating of performance was conducted for each participant by his/her partner. Results were analyzed separately for biomechanical parameters for partner ratings using the Student t test with levels of significance (P visual feedback was associated with change in the biomechanical performance of group 2, a minimum of 14% and a maximum of 32%. Statistical analysis rating of the performance favored the feedback group on 4 of the parameters (fast, P < .0008; force, P < .0056; precision, P < .0034; and composite, P < .0016). Quantitative feedback, based on a tangible conceptualization of the target performance, resulted in immediate and significant improvement in all measured parameters. Newly developed skills were retained at least over short intervals even after distractive tasks. Learning what to do with feedback on one's own performance may be more important than the classic teaching of how to do it.

  5. Real-time computer-based visual feedback improves visual acuity in downbeat nystagmus - a pilot study.

    Science.gov (United States)

    Teufel, Julian; Bardins, S; Spiegel, Rainer; Kremmyda, O; Schneider, E; Strupp, M; Kalla, R

    2016-01-04

    Patients with downbeat nystagmus syndrome suffer from oscillopsia, which leads to an unstable visual perception and therefore impaired visual acuity. The aim of this study was to use real-time computer-based visual feedback to compensate for the destabilizing slow phase eye movements. The patients were sitting in front of a computer screen with the head fixed on a chin rest. The eye movements were recorded by an eye tracking system (EyeSeeCam®). We tested the visual acuity with a fixed Landolt C (static) and during real-time feedback driven condition (dynamic) in gaze straight ahead and (20°) sideward gaze. In the dynamic condition, the Landolt C moved according to the slow phase eye velocity of the downbeat nystagmus. The Shapiro-Wilk test was used to test for normal distribution and one-way ANOVA for comparison. Ten patients with downbeat nystagmus were included in the study. Median age was 76 years and the median duration of symptoms was 6.3 years (SD +/- 3.1y). The mean slow phase velocity was moderate during gaze straight ahead (1.44°/s, SD +/- 1.18°/s) and increased significantly in sideward gaze (mean left 3.36°/s; right 3.58°/s). In gaze straight ahead, we found no difference between the static and feedback driven condition. In sideward gaze, visual acuity improved in five out of ten subjects during the feedback-driven condition (p = 0.043). This study provides proof of concept that non-invasive real-time computer-based visual feedback compensates for the SPV in DBN. Therefore, real-time visual feedback may be a promising aid for patients suffering from oscillopsia and impaired text reading on screen. Recent technological advances in the area of virtual reality displays might soon render this approach feasible in fully mobile settings.

  6. Use of visual feedback in retraining balance following acute stroke.

    Science.gov (United States)

    Walker, C; Brouwer, B J; Culham, E G

    2000-09-01

    Visual feedback related to weight distribution and center-of-pressure positioning has been shown to be effective in increasing stance symmetry following stroke, although it is not clear whether functional balance ability also improves. This study compared the relative effectiveness of visual feedback training of center-of-gravity (CoG) positioning with conventional physical therapy following acute stroke. Forty-six people who had strokes within 80 days before the study, resulting in unilateral hemiparesis, and who were in need of balance retraining participated. Initially, subjects were randomly assigned to visual feedback or conventional physical therapy groups for balance retraining until 16 subjects per group were recruited. The next 14 subjects were assigned to a control group. All subjects received physical therapy and occupational therapy (regular therapy) 2 hours a day, and subjects in the 2 experimental groups received additional balance training 30 minutes a day until discharge. The visual feedback group received information about their CoG position as they shifted their weight during various activities. The conventional therapy group received verbal and tactile cues to encourage symmetrical stance and weight shifting. Static (postural sway) and activity-based measures of balance (Berg Balance Scale, gait speed, and the Timed "Up & Go" Test) were contrasted across the 3 groups at baseline, at discharge, and at 1 month following discharge using an analysis of variance for repeated measures. All groups demonstrated marked improvement over time for all measures of balance ability, with the greatest improvements occurring in the period from baseline to discharge. No between-group differences were detected in any of the outcome measures. Visual feedback or conventional balance training in addition to regular therapy affords no added benefit when offered in the early stages of rehabilitation following stroke.

  7. Feedback Providing Improvement Strategies and Reflection on Feedback Use: Effects on Students' Writing Motivation, Process, and Performance

    Science.gov (United States)

    Duijnhouwer, Hendrien; Prins, Frans J.; Stokking, Karel M.

    2012-01-01

    This study investigated the effects of feedback providing improvement strategies and a reflection assignment on students' writing motivation, process, and performance. Students in the experimental feedback condition (n = 41) received feedback including improvement strategies, whereas students in the control feedback condition (n = 41) received…

  8. A feedback system in residency to evaluate CanMEDS roles and provide high-quality feedback : Exploring its application

    NARCIS (Netherlands)

    Renting, Nienke; Gans, Rijk O. B.; Borleffs, Jan C. C.; Van Der Wal, Martha A.; Jaarsma, A. Debbie C.; Cohen-Schotanus, Janke

    Introduction: Residents benefit from regular, high quality feedback on all CanMEDS roles during their training. However, feedback mostly concerns Medical Expert, leaving the other roles behind. A feedback system was developed to guide supervisors in providing feedback on CanMEDS roles. We analyzed

  9. Development of a teleoperated micromanipulation system with visual and haptic feedback

    Science.gov (United States)

    Ferreira, Antoine; Cassier, Claude; Haddab, Yassine; Rougeot, Patrick; Chaillet, Nicolas

    2001-10-01

    Concerning the teleoperation between different scale worlds, it is important to take into account the scaling effect problem in terms of manipulator precision, human sensation, environment accessibility, dexterity, etc. To consider these different problems, this paper presents the development of a new macro-micro teleoperated micromanipulator, with two kinds of micromanipulation systems: a piezoelectric microgripper and an atomic force microscope (AFM) operating under an optical microscope. The natural force feedback sensation exerted on the piezoelectric microgripper is given through a teleoperated two-fingered planar hand mechanism. This system provides the human operator with natural force feedback sensation and augmented visual feedback while telemanipulating objects in the micro world. Firstly, the bilateral control system with active force feedback based on hybrid master-slave technologies is modeled. The results include the use of force feedback and power assist in order to demonstrate the feasibility and practicability of the micro-teleoperated system. Then, in order to improve the visual feedback issued form the optical microscope of the station, a virtual micro 3D environment is proposed. By combining 2D microscope images and augmented reality-based programming techniques, we reconstructed exactly the operational microworld. Finally, some experiments have been carried out in order to verify the validity of the proposed bilateral control scheme and to calibrate the developed virtual model incorporating visual and haptic feedback.

  10. The generation of secondary saccades without postsaccadic visual feedback.

    Science.gov (United States)

    Ohl, Sven; Brandt, Stephan A; Kliegl, Reinhold

    2013-04-12

    Primary saccades are often followed by small secondary saccades, which are generally thought to reduce the distance between the saccade endpoint and target location. Accumulated evidence demonstrates that secondary saccades are subject to various influences, among which retinal feedback during postsaccadic fixation constitutes only one important signal. Recently, we reported that target eccentricity and an orientation bias influence the generation of secondary saccades. In the present study, we examine secondary saccades in the absence of postsaccadic visual feedback. Although extraretinal signals (e.g., efference copy) have received widespread attention in eye-movement studies, it is still unclear whether an extraretinal error signal contributes to the programming of secondary saccades. We have observed that secondary saccade latency and amplitude depend on primary saccade error despite the absence of postsaccadic visual feedback. Strong evidence for an extraretinal error signal influencing secondary saccade programming is given by the observation that secondary saccades are more likely to be oriented in a direction opposite to the primary saccade as primary saccade error shifts from target undershoot to overshoot. We further show how the functional relationship between primary saccade landing position and secondary saccade characteristics varies as a function of target eccentricity. We propose that initial target eccentricity and an extraretinal error signal codetermine the postsaccadic activity distribution in the saccadic motor map when no visual feedback is available.

  11. Brain-actuated gait trainer with visual and proprioceptive feedback

    Science.gov (United States)

    Liu, Dong; Chen, Weihai; Lee, Kyuhwa; Chavarriaga, Ricardo; Bouri, Mohamed; Pei, Zhongcai; Millán, José del R.

    2017-10-01

    Objective. Brain-machine interfaces (BMIs) have been proposed in closed-loop applications for neuromodulation and neurorehabilitation. This study describes the impact of different feedback modalities on the performance of an EEG-based BMI that decodes motor imagery (MI) of leg flexion and extension. Approach. We executed experiments in a lower-limb gait trainer (the legoPress) where nine able-bodied subjects participated in three consecutive sessions based on a crossover design. A random forest classifier was trained from the offline session and tested online with visual and proprioceptive feedback, respectively. Post-hoc classification was conducted to assess the impact of feedback modalities and learning effect (an improvement over time) on the simulated trial-based performance. Finally, we performed feature analysis to investigate the discriminant power and brain pattern modulations across the subjects. Main results. (i) For real-time classification, the average accuracy was 62.33 +/- 4.95 % and 63.89 +/- 6.41 % for the two online sessions. The results were significantly higher than chance level, demonstrating the feasibility to distinguish between MI of leg extension and flexion. (ii) For post-hoc classification, the performance with proprioceptive feedback (69.45 +/- 9.95 %) was significantly better than with visual feedback (62.89 +/- 9.20 %), while there was no significant learning effect. (iii) We reported individual discriminate features and brain patterns associated to each feedback modality, which exhibited differences between the two modalities although no general conclusion can be drawn. Significance. The study reported a closed-loop brain-controlled gait trainer, as a proof of concept for neurorehabilitation devices. We reported the feasibility of decoding lower-limb movement in an intuitive and natural way. As far as we know, this is the first online study discussing the role of feedback modalities in lower-limb MI decoding. Our results suggest that

  12. Self-Produced Tickle Sensation by Manipulating Visual Feedback

    Directory of Open Access Journals (Sweden)

    Hiroyuki Iizuka

    2011-10-01

    Full Text Available The aim of the present paper was to clarify how the distinction of self- (sense of agency, SOA and other-produced behavior can be synthesized and recognized in multisensory integration as our cognitive processes. To address this issue, we used tickling paradigm that it is hard for us to tickle ourselves. Previous studies show that tickle sensation by their own motion increases if more delay is given between self-motion of tickling and tactile stimulation (Blakemore et al. 1998, 1999. We introduced visual feedbacks to the tickling experiments. In our hypothesis, integration of vision, proprioception, and motor commands forms the SOA and disintegration causes the breakdown the SOA, which causes the feeling of others, producing tickling sensation even by tickling oneself. We used video-see-through HMD to suddenly delay the real-time images of their hand tickling motions. The tickle sensation was measured by subjective response in the following conditions; 1 tickling oneself without any visual modulation, 2 tickled by others, 3 tickling oneself with visual feedback manipulation. The statistical analysis of ranked evaluation of tickle sensations showed that the delay of visual feedback causes the increase of tickle sensation. The SOA was discussed with Blakemore's and our results.

  13. Real-time feedback on nonverbal clinical communication. Theoretical framework and clinician acceptance of ambient visual design.

    Science.gov (United States)

    Hartzler, A L; Patel, R A; Czerwinski, M; Pratt, W; Roseway, A; Chandrasekaran, N; Back, A

    2014-01-01

    This article is part of the focus theme of Methods of Information in Medicine on "Pervasive Intelligent Technologies for Health". Effective nonverbal communication between patients and clinicians fosters both the delivery of empathic patient-centered care and positive patient outcomes. Although nonverbal skill training is a recognized need, few efforts to enhance patient-clinician communication provide visual feedback on nonverbal aspects of the clinical encounter. We describe a novel approach that uses social signal processing technology (SSP) to capture nonverbal cues in real time and to display ambient visual feedback on control and affiliation--two primary, yet distinct dimensions of interpersonal nonverbal communication. To examine the design and clinician acceptance of ambient visual feedback on nonverbal communication, we 1) formulated a model of relational communication to ground SSP and 2) conducted a formative user study using mixed methods to explore the design of visual feedback. Based on a model of relational communication, we reviewed interpersonal communication research to map nonverbal cues to signals of affiliation and control evidenced in patient-clinician interaction. Corresponding with our formulation of this theoretical framework, we designed ambient real-time visualizations that reflect variations of affiliation and control. To explore clinicians' acceptance of this visual feedback, we conducted a lab study using the Wizard-of-Oz technique to simulate system use with 16 healthcare professionals. We followed up with seven of those participants through interviews to iterate on the design with a revised visualization that addressed emergent design considerations. Ambient visual feedback on non- verbal communication provides a theoretically grounded and acceptable way to provide clinicians with awareness of their nonverbal communication style. We provide implications for the design of such visual feedback that encourages empathic patient

  14. Trans-Tibial Amputee Gait Correction through Real-Time Visual Feedback

    Directory of Open Access Journals (Sweden)

    Seyyed Farhad Tabatabi Ghomshe

    2016-03-01

    Full Text Available Objective: The present paper reports on program of work undertaken to evaluate the effect of real time visual feedback on kinematics of prosthetic gait. Methods: A total of 6 below-knee male amputees were included in the study. Each individual underwent three trials of self-selected speed treadmill walking, in which real time visual feedback was provided from forward, backward, and lateral views, together with a control trial without any visual feedback. Kinematic reference values were captured via VICON motion analysis system, and one-minute slots of data sets were processed by its Workstation software (Plug in Gait, which were than statistically analyzed running Wilcoxon Signed-Rank Test. Results: Statistical analyses revealed significant differences in stance phase (Z=0.923, p=0.031 and stride length (Z=-1.807, p=0.043 between normal and affected sides in front visual feedback mode. Stance phase was generally extended on normal legs, and there appeared to be reductions in hip joint range of motion on affected limbs. Stride time followed relatively comparable patterns in both sides across all trials. Conclusion: The results suggest that providing visualization in the context of amputee gait rehabilitation may provide an effective way to help subjects correct gait patterns and thereby it may improve the outcome of rehabilitation.

  15. Learning without knowing: subliminal visual feedback facilitates ballistic motor learning

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Leukel, Christian; Nielsen, Jens Bo

    ). It is a well- described phenomenon that we may respond to features of our surroundings without being aware of them. It is also a well-known principle, that learning is reinforced by augmented feedback on motor performance. In the present experiment we hypothesized that motor learning may be facilitated...... by subconscious (subliminal) augmented visual feedback on motor performance. To test this, 45 subjects participated in the experiment, which involved learning of a ballistic task. The task was to execute simple ankle plantar flexion movements as quickly as possible within 200 ms and to continuously improve...... of the feedback) was assessed in a separate test prior to the actual experiment and additional perceptual tests were performed after the learning session. In all 3 intervention groups motor performance improved as a result of practice. Not surprisingly the learning effect was significantly larger if subjects...

  16. Proprioceptive deafferentation slows down the processing of visual hand feedback

    DEFF Research Database (Denmark)

    Balslev, Daniela; Miall, R Chris; Cole, Jonathan

    2007-01-01

    . Correlation analyses suggested that reaction time was influenced by the size of the visual error rather than the visuo-proprioceptive conflict or the variance in cursor position. We suggest that during movements intact proprioception is necessary for the rapid processing of visual feedback.......During visually guided movements both vision and proprioception inform the brain about the position of the hand, so interaction between these two modalities is presumed. Current theories suggest that this interaction occurs by sensory information from both sources being fused into a more reliable...... was compared under conditions with normal and reduced proprioception after 1-Hz rTMS over the hand-contralateral somatosensory cortex. Proprioceptive deafferentation slowed down the reaction time for initiating a motor correction in response to a visual perturbation in hand position, but not to a target jump...

  17. Visual Feedback of Tongue Movement for Novel Speech Sound Learning

    OpenAIRE

    Katz, William F.; Sonya eMehta

    2015-01-01

    Pronunciation training studies have yielded important information concerning the processing of audiovisual (AV) information. Second language (L2) learners show increased reliance on bottom-up, multimodal input for speech perception (compared to monolingual individuals). However, little is known about the role of viewing one's own speech articulation processes during speech training. The current study investigated whether real-time, visual feedback for tongue movement can improve a speaker's l...

  18. Motor sequence learning occurs despite disrupted visual and proprioceptive feedback

    Directory of Open Access Journals (Sweden)

    Boyd Lara A

    2008-07-01

    Full Text Available Abstract Background Recent work has demonstrated the importance of proprioception for the development of internal representations of the forces encountered during a task. Evidence also exists for a significant role for proprioception in the execution of sequential movements. However, little work has explored the role of proprioceptive sensation during the learning of continuous movement sequences. Here, we report that the repeated segment of a continuous tracking task can be learned despite peripherally altered arm proprioception and severely restricted visual feedback regarding motor output. Methods Healthy adults practiced a continuous tracking task over 2 days. Half of the participants experienced vibration that altered proprioception of shoulder flexion/extension of the active tracking arm (experimental condition and half experienced vibration of the passive resting arm (control condition. Visual feedback was restricted for all participants. Retention testing was conducted on a separate day to assess motor learning. Results Regardless of vibration condition, participants learned the repeated segment demonstrated by significant improvements in accuracy for tracking repeated as compared to random continuous movement sequences. Conclusion These results suggest that with practice, participants were able to use residual afferent information to overcome initial interference of tracking ability related to altered proprioception and restricted visual feedback to learn a continuous motor sequence. Motor learning occurred despite an initial interference of tracking noted during acquisition practice.

  19. Enhance students’ motivation to learn programming by using direct visual feed-back

    DEFF Research Database (Denmark)

    Kofoed, Lise B.; Reng, Lars

    2011-01-01

    The technical subjects chosen are within programming. Using image-processing algorithms as means to provide direct visual feedback for learning basic C/C++. The pedagogical approach is within a PBL framework and is based on dialogue and collaborative learning. At the same time the intention was t...... to a satisfactory level seen from the study board’s point of view....

  20. Ultrasound as Visual Feedback in Speech Habilitation: Exploring Consultative Use in Rural British Columbia, Canada

    Science.gov (United States)

    Bernhardt, B. May; Bacsfalvi, Penelope; Adler-Bock, Marcy; Shimizu, Reiko; Cheney, Audrey; Giesbrecht, Nathan; O'Connell, Maureen; Sirianni, Jason; Radanov, Bosko

    2008-01-01

    Ultrasound has shown promise as a visual feedback tool in speech therapy. Rural clients, however, often have minimal access to new technologies. The purpose of the current study was to evaluate consultative treatment using ultrasound in rural communities. Two speech-language pathologists (SLPs) trained in ultrasound use provided consultation with…

  1. Effect of a contact monitoring system with immediate visual feedback on hand hygiene compliance.

    Science.gov (United States)

    Storey, S J; FitzGerald, G; Moore, G; Knights, E; Atkinson, S; Smith, S; Freeman, O; Cryer, P; Wilson, A P R

    2014-10-01

    Hand hygiene compliance is traditionally monitored by visual methods that are open to bias and strictly limited in time and place. Automatic monitoring may be more effective for infection control as well as performance management. To establish accuracy and acceptability of an automatic contact monitoring system for hand hygiene. Monitoring equipment was installed across 55 beds in three wards, and included modified identity badges, bedside furniture, sinks and alcohol gel dispensers. Badges were in near-skin contact (through uniform) and could detect alcohol vapour. All devices were linked by wi-fi. A traffic light system on the badge provided immediate feedback to staff and patients on the hand hygiene status of a member of staff on approach to a patient. Compliance was logged automatically. Following a period of immediate feedback, no visual feedback was given for two weeks. Subsequently, feedback was given using red/green lights for 10 days, followed by retrospective feedback to the ward. Hand hygiene was verified independently by an observer. Hand hygiene compliance increased from 21% of 97 opportunities to 66% of 197 opportunities during active immediate feedback. Compliance decreased when feedback was provided to wards retrospectively. Six staff (26%) avoided wearing a badge, saying that it was too heavy or they were not on the ward all day. Only three of 30 patients stated that they would challenge staff who had not performed hand hygiene. Automatic contact monitoring with immediate feedback was effective in increasing hand hygiene compliance, but feedback given retrospectively did not prevent a decrease in compliance. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  2. Generalization and Maintenance of Social Skills of Children with Visual Impairments: Self-Evaluation and the Role of Feedback

    Science.gov (United States)

    Jindal-Snape, Divya

    2004-01-01

    A multiple baseline design across behaviors was used with two visually impaired girls to establish the effectiveness of self-evaluation and the role of feedback. In both cases, self-evaluation was effective in increasing the girls' social skills and social interaction. Implications of the role of significant others in providing feedback are…

  3. Visual feedback of tongue movement for novel speech sound learning

    Directory of Open Access Journals (Sweden)

    William F Katz

    2015-11-01

    Full Text Available Pronunciation training studies have yielded important information concerning the processing of audiovisual (AV information. Second language (L2 learners show increased reliance on bottom-up, multimodal input for speech perception (compared to monolingual individuals. However, little is known about the role of viewing one’s own speech articulation processes during speech training. The current study investigated whether real-time, visual feedback for tongue movement can improve a speaker’s learning of non-native speech sounds. An interactive 3D tongue visualization system based on electromagnetic articulography (EMA was used in a speech training experiment. Native speakers of American English produced a novel speech sound (/ɖ̠/; a voiced, coronal, palatal stop before, during, and after trials in which they viewed their own speech movements using the 3D model. Talkers’ productions were evaluated using kinematic (tongue-tip spatial positioning and acoustic (burst spectra measures. The results indicated a rapid gain in accuracy associated with visual feedback training. The findings are discussed with respect to neural models for multimodal speech processing.

  4. Visual Feedback of Tongue Movement for Novel Speech Sound Learning.

    Science.gov (United States)

    Katz, William F; Mehta, Sonya

    2015-01-01

    Pronunciation training studies have yielded important information concerning the processing of audiovisual (AV) information. Second language (L2) learners show increased reliance on bottom-up, multimodal input for speech perception (compared to monolingual individuals). However, little is known about the role of viewing one's own speech articulation processes during speech training. The current study investigated whether real-time, visual feedback for tongue movement can improve a speaker's learning of non-native speech sounds. An interactive 3D tongue visualization system based on electromagnetic articulography (EMA) was used in a speech training experiment. Native speakers of American English produced a novel speech sound (/ɖ/; a voiced, coronal, palatal stop) before, during, and after trials in which they viewed their own speech movements using the 3D model. Talkers' productions were evaluated using kinematic (tongue-tip spatial positioning) and acoustic (burst spectra) measures. The results indicated a rapid gain in accuracy associated with visual feedback training. The findings are discussed with respect to neural models for multimodal speech processing.

  5. Visualization feedback for musical ensemble practice: a case study on phrase articulation and dynamics

    Science.gov (United States)

    Knight, Trevor; Boulliot, Nicolas; Cooperstock, Jeremy R.

    2012-01-01

    We consider the possible advantages of visualization in supporting musical interpretation. Specifically, we investigate the use of visualizations in making a subjective judgement of a student's performance compared to reference "expert" performance for particular aspects of musical performance-articulation and dynamics. Our assessment criteria for the effectiveness of the feedback are based on the consistency of judgements made by the participants using each modality, that is to say, in determining how well the student musician matches the reference musician, the time taken to evaluate each pair of samples, and subjective opinion of perceived utility of the feedback. For articulation, differences in the mean scores assigned by the participants to the reference versus the student performance were not statistically significant for each modality. This suggests that while the visualization strategy did not offer any advantage over presentation of the samples by audio playback alone, visualization nevertheless provided sufficient information to make similar ratings. For dynamics, four of our six participants categorized the visualizations as helpful. The means of their ratings for the visualization-only and both-together conditions were not statistically different but were statistically different from the audio-only treatment, indicating a dominance of the visualizations when presented together with audio. Moreover, the ratings of dynamics under the visualization-only condition were significantly more consistent than the other conditions.

  6. A counterbalanced cross-over study of the effects of visual, auditory and no feedback on performance measures in a simulated cardiopulmonary resuscitation

    Directory of Open Access Journals (Sweden)

    Baxley Susan M

    2011-08-01

    Full Text Available Abstract Background Previous research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR. Feedback on rate and depth mitigate decline in performance quality but not completely with the residual performance decline attributed to rescuer fatigue. The purpose of this study was to examine the effects of feedback (none, auditory only and visual only on the quality of CPR and rescuer fatigue. Methods Fifteen female volunteers performed 10 minutes of 30:2 CPR in each of three feedback conditions: none, auditory only, and visual only. Visual feedback was displayed continuously in graphic form. Auditory feedback was error correcting and provided by a voice assisted CPR manikin. CPR quality measures were collected using SkillReporter® software. Blood lactate (mmol/dl and perceived exertion served as indices of fatigue. One-way and two way repeated measures analyses of variance were used with alpha set a priori at 0.05. Results Visual feedback yielded a greater percentage of correct compressions (78.1 ± 8.2% than did auditory (65.4 ± 7.6% or no feedback (44.5 ± 8.1%. Compression rate with auditory feedback (87.9 ± 0.5 compressions per minute was less than it was with both visual and no feedback (p Conclusions In this study feedback mitigated the negative effects of fatigue on CPR performance and visual feedback yielded better CPR performance than did no feedback or auditory feedback. The perfect confounding of sensory modality and periodicity of feedback (visual feedback provided continuously and auditory feedback provided to correct error leaves unanswered the question of optimal form and timing of feedback.

  7. A method for calculating active feedback system to provide vertical ...

    Indian Academy of Sciences (India)

    not difficult to see that ϕ (+∞)=+∞. Therefore, for the equation ϕ (γ)=0to have no positive root, the fulfillment of the following condition is necessary: ϕ (0) = (R−1w, a) − w0 ≥ 0. (12). We will call (12) as the necessary condition of vertical position control by active feedbacks. 5. Problem of selection of active feedback system.

  8. Teacher's Attitude into Different Approach to Providing Feedback to Students in Higher Education

    Science.gov (United States)

    Chaqmaqchee, Zina Adil

    2015-01-01

    Feedback within higher education has an effective role in teaching staffs mode. The treatise on teachers' methods of feedback is represented to demonstrate how the novel feedback can help the academic staffs to provide an effective feedback for students in their assignments and written draft. The study investigates the academic staff's methods of…

  9. Head and Tibial Acceleration as a Function of Stride Frequency and Visual Feedback during Running.

    Directory of Open Access Journals (Sweden)

    Michael A Busa

    Full Text Available Individuals regulate the transmission of shock to the head during running at different stride frequencies although the consequences of this on head-gaze stability remain unclear. The purpose of this study was to examine if providing individuals with visual feedback of their head-gaze orientation impacts tibial and head accelerations, shock attenuation and head-gaze motion during preferred speed running at different stride frequencies. Fifteen strides from twelve recreational runners running on a treadmill at their preferred speed were collected during five stride frequencies (preferred, ±10% and ±20% of preferred in two visual task conditions (with and without real-time visual feedback of head-gaze orientation. The main outcome measures were tibial and head peak accelerations assessed in the time and frequency domains, shock attenuation from tibia to head, and the magnitude and velocity of head-gaze motion. Decreasing stride frequency resulted in greater vertical accelerations of the tibia (p<0.01 during early stance and at the head (p<0.01 during early and late stance; however, for the impact portion the increase in head acceleration was only observed for the slowest stride frequency condition. Visual feedback resulted in reduced head acceleration magnitude (p<0.01 and integrated power spectral density in the frequency domain (p<0.01 in late stance, as well as overall of head-gaze motion (p<0.01. When running at preferred speed individuals were able to stabilize head acceleration within a wide range of stride frequencies; only at a stride frequency 20% below preferred did head acceleration increase. Furthermore, impact accelerations of the head and tibia appear to be solely a function of stride frequency as no differences were observed between feedback conditions. Increased visual task demands through head gaze feedback resulted in reductions in head accelerations in the active portion of stance and increased head-gaze stability.

  10. A counterbalanced cross-over study of the effects of visual, auditory and no feedback on performance measures in a simulated cardiopulmonary resuscitation.

    Science.gov (United States)

    Cason, Carolyn L; Trowbridge, Cynthia; Baxley, Susan M; Ricard, Mark D

    2011-08-02

    Previous research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR). Feedback on rate and depth mitigate decline in performance quality but not completely with the residual performance decline attributed to rescuer fatigue. The purpose of this study was to examine the effects of feedback (none, auditory only and visual only) on the quality of CPR and rescuer fatigue. Fifteen female volunteers performed 10 minutes of 30:2 CPR in each of three feedback conditions: none, auditory only, and visual only. Visual feedback was displayed continuously in graphic form. Auditory feedback was error correcting and provided by a voice assisted CPR manikin. CPR quality measures were collected using SkillReporter® software. Blood lactate (mmol/dl) and perceived exertion served as indices of fatigue. One-way and two way repeated measures analyses of variance were used with alpha set a priori at 0.05. Visual feedback yielded a greater percentage of correct compressions (78.1 ± 8.2%) than did auditory (65.4 ± 7.6%) or no feedback (44.5 ± 8.1%). Compression rate with auditory feedback (87.9 ± 0.5 compressions per minute) was less than it was with both visual and no feedback (p < 0.05). CPR performed with no feedback (39.2 ± 0.5 mm) yielded a shallower average depth of compression and a lower percentage (55 ± 8.9%) of compressions within the accepted 38-50 mm range than did auditory or visual feedback (p < 0.05). The duty cycle for auditory feedback (39.4 ± 1.6%) was less than it was with no feedback (p < 0.05). Auditory feedback produced lower lactate concentrations than did visual feedback (p < 0.05) but there were no differences in perceived exertion. In this study feedback mitigated the negative effects of fatigue on CPR performance and visual feedback yielded better CPR performance than did no feedback or auditory feedback

  11. Visual areas exert feedforward and feedback influences through distinct frequency channels

    NARCIS (Netherlands)

    Bastos, A.M.; Vezoli, J.; Bosman, C.A.; Schoffelen, J.M.; Oostenveld, R.; Dowdall, J.R.; de Weerd, P.; Kennedy, H.; Fries, P.

    2015-01-01

    Visual cortical areas subserve cognitive functions by interacting in both feedforward and feedback directions. While feedforward influences convey sensory signals, feedback influences modulate feedforward signaling according to the current behavioral context. We investigated whether these interareal

  12. The Effects of Self-Generated Synchronous and Asynchronous Visual Speech Feedback on Overt Stuttering Frequency

    Science.gov (United States)

    Snyder, Gregory J.; Hough, Monica Strauss; Blanchet, Paul; Ivy, Lennette J.; Waddell, Dwight

    2009-01-01

    Purpose: Relatively recent research documents that visual choral speech, which represents an externally generated form of synchronous visual speech feedback, significantly enhanced fluency in those who stutter. As a consequence, it was hypothesized that self-generated synchronous and asynchronous visual speech feedback would likewise enhance…

  13. Experimental System for Investigation of Visual Sensory Input in Postural Feedback Control

    Directory of Open Access Journals (Sweden)

    Jozef Pucik

    2012-01-01

    Full Text Available The human postural control system represents a biological feedback system responsible for maintenance of upright stance. Vestibular, proprioceptive and visual sensory inputs provide the most important information into the control system, which controls body centre of mass (COM in order to stabilize the human body resembling an inverted pendulum. The COM can be measured indirectly by means of a force plate as the centre of pressure (COP. Clinically used measurement method is referred to as posturography. In this paper, the conventional static posturography is extended by visual stimulation, which provides insight into a role of visual information in balance control. Visual stimuli have been designed to induce body sway in four specific directions – forward, backward, left and right. Stabilograms were measured using proposed single-PC based system and processed to calculate velocity waveforms and posturographic parameters. The parameters extracted from pre-stimulus and on-stimulus periods exhibit statistically significant differences.

  14. Exploring the value of peer feedback in online learning for the provider

    NARCIS (Netherlands)

    Marijke Kral; Gino Camp; Esther van Popta; Robert Jan Simons; Rob L. Martens

    2017-01-01

    This paper reviews studies of peer feedback from the novel perspective of the providers of that feedback. The possible learning benefits of providing peer feedback in online learning have not been extensively studied. The goal of this study was therefore to explore the process of providing online

  15. Perception of CPR quality: Influence of CPR feedback, Just-in-Time CPR training and provider role.

    Science.gov (United States)

    Cheng, Adam; Overly, Frank; Kessler, David; Nadkarni, Vinay M; Lin, Yiqun; Doan, Quynh; Duff, Jonathan P; Tofil, Nancy M; Bhanji, Farhan; Adler, Mark; Charnovich, Alex; Hunt, Elizabeth A; Brown, Linda L

    2015-02-01

    Many healthcare providers rely on visual perception to guide cardiopulmonary resuscitation (CPR), but little is known about the accuracy of provider perceptions of CPR quality. We aimed to describe the difference between perceived versus measured CPR quality, and to determine the impact of provider role, real-time visual CPR feedback and Just-in-Time (JIT) CPR training on provider perceptions. We conducted secondary analyses of data collected from a prospective, multicenter, randomized trial of 324 healthcare providers who participated in a simulated cardiac arrest scenario between July 2012 and April 2014. Participants were randomized to one of four permutations of: JIT CPR training and real-time visual CPR feedback. We calculated the difference between perceived and measured quality of CPR and reported the proportion of subjects accurately estimating the quality of CPR within each study arm. Participants overestimated achieving adequate chest compression depth (mean difference range: 16.1-60.6%) and rate (range: 0.2-51%), and underestimated chest compression fraction (0.2-2.9%) across all arms. Compared to no intervention, the use of real-time feedback and JIT CPR training (alone or in combination) improved perception of depth (pPerception of depth is more accurate in CPR providers versus team leaders (27.8% vs. 7.4%; p=0.043) when using real-time feedback. Healthcare providers' visual perception of CPR quality is poor. Perceptions of CPR depth are improved by using real-time visual feedback and with prior JIT CPR training. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. A Multimedia Visual Feedback in the Web-controlled Laboratory

    Directory of Open Access Journals (Sweden)

    J. Turan

    2012-06-01

    Full Text Available The paper presents development work related to create WWW based remote control laboratory for teaching Applied Photonics. In order to minimize the cost at the end-user domain, simple WWW browser with fundamental plug-in (Java applets, HTML Pages and LabWindows applets to support the remote control and video transmission functionality of the remote control is proposed. As for telepresence and monitoring of device actions, a simple type zooming web-camera is connected to the hosting multimedia PC via the USB port. The web-camera assists in visual feedback of the system and presents the feeling of telepresence for the end-user (student. USB web-cameras are normally efficient and the presence of another video server is not necessary in this case, thanks to LabWindows.

  17. Sensorimotor control of gait: A novel approach for the study of the interplay of visual and proprioceptive feedback

    Directory of Open Access Journals (Sweden)

    Ryan eFrost

    2015-02-01

    Full Text Available Sensorimotor control theories propose that the central nervous system exploits expected sensory consequences generated by motor commands for movement planning, as well as online sensory feedback for comparison with expected sensory feedback for monitoring and correcting, if needed, ongoing motor output. In our study, we tested this theoretical framework by quantifying the functional role of expected versus actual proprioceptive feedback for planning and regulation of gait in humans. We addressed this question by using a novel methodological approach to deliver fast perturbations of the walking surface stiffness, in conjunction with a virtual reality system that provided visual feedback of upcoming changes of surface stiffness. In the predictable experimental condition, we asked subjects to learn associating visual feedback of changes in floor stiffness (sand patch during locomotion to quantify kinematic and kinetic changes in gait. In the unpredictable experimental condition, we perturbed floor stiffness at unpredictable instances during the gait to characterize the gait-phase dependent strategies in recovering the locomotor cycle. For the unpredictable conditions, visual feedback of changes in floor stiffness was absent or inconsistent with tactile and proprioceptive feedback. The investigation of these perturbation-induced effects on legs kinematics revealed that visual feedback of upcoming changes in floor stiffness allows for both early (preparatory and late (post-perturbation changes in leg kinematics. However, when proprioceptive feedback is not available, the early responses do not occur while the late responses are preserved although in a, slightly attenuated form. The methods proposed and the preliminary results of this study open new directions for the investigation of the relative role of visual, tactile, and proprioceptive feedback on gait control, with potential implications for designing novel robot-assisted gait rehabilitation

  18. Sensorimotor Learning of Acupuncture Needle Manipulation Using Visual Feedback.

    Directory of Open Access Journals (Sweden)

    Won-Mo Jung

    Full Text Available Humans can acquire a wide variety of motor skills using sensory feedback pertaining to discrepancies between intended and actual movements. Acupuncture needle manipulation involves sophisticated hand movements and represents a fundamental skill for acupuncturists. We investigated whether untrained students could improve their motor performance during acupuncture needle manipulation using visual feedback (VF.Twenty-one untrained medical students were included, randomly divided into concurrent (n = 10 and post-trial (n = 11 VF groups. Both groups were trained in simple lift/thrusting techniques during session 1, and in complicated lift/thrusting techniques in session 2 (eight training trials per session. We compared the motion patterns and error magnitudes of pre- and post-training tests.During motion pattern analysis, both the concurrent and post-trial VF groups exhibited greater improvements in motion patterns during the complicated lifting/thrusting session. In the magnitude error analysis, both groups also exhibited reduced error magnitudes during the simple lifting/thrusting session. For the training period, the concurrent VF group exhibited reduced error magnitudes across all training trials, whereas the post-trial VF group was characterized by greater error magnitudes during initial trials, which gradually reduced during later trials.Our findings suggest that novices can improve the sophisticated hand movements required for acupuncture needle manipulation using sensorimotor learning with VF. Use of two types of VF can be beneficial for untrained students in terms of learning how to manipulate acupuncture needles, using either automatic or cognitive processes.

  19. Power Assist Control of Robotic Wheelchair Based on Visual Feedback

    Science.gov (United States)

    Oda, Naoki; Shimizu, Hiroyuki

    This paper describes a vision based self-velocity estimation and its feedback system under force/torque sensor-less power assisting control of wheelchair robot. In this method, three dimensional information obtained by stereo images, and the optical flow vectors are also used for self-velocity estimation in real-time. The human force is estimated by sensor-less reaction force observer, and the assisting force is calculated by using its estimated force and virtual impedance model. In the paper, the force based assist function is integrated into visual feedback motion controller. This approach using vision and force based assist control makes it possible to facilitate the direct intelligent interactions between human force and environments such as human following assist, obstacle avoidance one and so on. Such assist functions are changeable by the selection of the weighting matrix in the velocity estimation, which is based on weighted least square solutions from optical flow vectors. The validity of the proposed approach is verified by several experimental results.

  20. Visual feedback alters force control and functional activity in the visuomotor network after stroke

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    Derek B. Archer

    2018-01-01

    Full Text Available Modulating visual feedback may be a viable option to improve motor function after stroke, but the neurophysiological basis for this improvement is not clear. Visual gain can be manipulated by increasing or decreasing the spatial amplitude of an error signal. Here, we combined a unilateral visually guided grip force task with functional MRI to understand how changes in the gain of visual feedback alter brain activity in the chronic phase after stroke. Analyses focused on brain activation when force was produced by the most impaired hand of the stroke group as compared to the non-dominant hand of the control group. Our experiment produced three novel results. First, gain-related improvements in force control were associated with an increase in activity in many regions within the visuomotor network in both the stroke and control groups. These regions include the extrastriate visual cortex, inferior parietal lobule, ventral premotor cortex, cerebellum, and supplementary motor area. Second, the stroke group showed gain-related increases in activity in additional regions of lobules VI and VIIb of the ipsilateral cerebellum. Third, relative to the control group, the stroke group showed increased activity in the ipsilateral primary motor cortex, and activity in this region did not vary as a function of visual feedback gain. The visuomotor network, cerebellum, and ipsilateral primary motor cortex have each been targeted in rehabilitation interventions after stroke. Our observations provide new insight into the role these regions play in processing visual gain during a precisely controlled visuomotor task in the chronic phase after stroke.

  1. Feature-Specific Organization of Feedback Pathways in Mouse Visual Cortex.

    Science.gov (United States)

    Huh, Carey Y L; Peach, John P; Bennett, Corbett; Vega, Roxana M; Hestrin, Shaul

    2018-01-08

    Higher and lower cortical areas in the visual hierarchy are reciprocally connected [1]. Although much is known about how feedforward pathways shape receptive field properties of visual neurons, relatively little is known about the role of feedback pathways in visual processing. Feedback pathways are thought to carry top-down signals, including information about context (e.g., figure-ground segmentation and surround suppression) [2-5], and feedback has been demonstrated to sharpen orientation tuning of neurons in the primary visual cortex (V1) [6, 7]. However, the response characteristics of feedback neurons themselves and how feedback shapes V1 neurons' tuning for other features, such as spatial frequency (SF), remain largely unknown. Here, using a retrograde virus, targeted electrophysiological recordings, and optogenetic manipulations, we show that putatively feedback neurons in layer 5 (hereafter "L5 feedback") in higher visual areas, AL (anterolateral area) and PM (posteromedial area), display distinct visual properties in awake head-fixed mice. AL L5 feedback neurons prefer significantly lower SF (mean: 0.04 cycles per degree [cpd]) compared to PM L5 feedback neurons (0.15 cpd). Importantly, silencing AL L5 feedback reduced visual responses of V1 neurons preferring low SF (mean change in firing rate: -8.0%), whereas silencing PM L5 feedback suppressed responses of high-SF-preferring V1 neurons (-20.4%). These findings suggest that feedback connections from higher visual areas convey distinctly tuned visual inputs to V1 that serve to boost V1 neurons' responses to SF. Such like-to-like functional organization may represent an important feature of feedback pathways in sensory systems and in the nervous system in general. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Can Turnitin Be Used to Provide Instant Formative Feedback?

    Science.gov (United States)

    Rolfe, Vivien

    2011-01-01

    New students face the challenge of making a smooth transition between school and university, and with regards to academic practice, there are often gaps between student expectations and university requirements. This study supports the use of the plagiarism detection service Turnitin to give students instant feedback on essays to help improve…

  3. High-speed visual feedback for realizing high-performance robotic manipulation

    Science.gov (United States)

    Huang, S.; Bergström, N.; Yamakawa, Y.; Senoo, T.; Ishikawa, M.

    2017-02-01

    High-speed vision sensing becomes a driving factor in developing new methods for robotic manipulation. In this paper we present two such methods in order to realize high-performance manipulation. First, we present a dynamic compensation approach which aims to achieve simultaneously fast and accurate positioning under various (from system to external environment) uncertainties. Second, a high-speed motion strategy for manipulating flexible objects is introduced to address the issue of deformation uncertainties. Both methods rely on high-speed visual feedback and are model independent, which we believe is essential to ensure good flexibility in a wide range of applications. The high-speed visual feedback tracks the relative error between the working tool and the target in image coordinates, which implies that there is no need for accurate calibrations of the vision system. Tasks for validating these methods were implemented and experimental results were provided to illustrate the effectiveness of the proposed methods.

  4. Attention Paid to Feedback Provided by a Computer-Based Assessment for Learning on Information Literacy

    Science.gov (United States)

    Timmers, Caroline; Veldkamp, Bernard

    2011-01-01

    Three studies are presented on attention paid to feedback provided by a computer-based assessment for learning on information literacy. Results show that the attention paid to feedback varies greatly. In general the attention focuses on feedback of incorrectly answered questions. In each study approximately fifty percent of the respondents paid…

  5. Audio-visual feedback improves the BCI performance in the navigational control of a humanoid robot.

    Science.gov (United States)

    Tidoni, Emmanuele; Gergondet, Pierre; Kheddar, Abderrahmane; Aglioti, Salvatore M

    2014-01-01

    Advancement in brain computer interfaces (BCI) technology allows people to actively interact in the world through surrogates. Controlling real humanoid robots using BCI as intuitively as we control our body represents a challenge for current research in robotics and neuroscience. In order to successfully interact with the environment the brain integrates multiple sensory cues to form a coherent representation of the world. Cognitive neuroscience studies demonstrate that multisensory integration may imply a gain with respect to a single modality and ultimately improve the overall sensorimotor performance. For example, reactivity to simultaneous visual and auditory stimuli may be higher than to the sum of the same stimuli delivered in isolation or in temporal sequence. Yet, knowledge about whether audio-visual integration may improve the control of a surrogate is meager. To explore this issue, we provided human footstep sounds as audio feedback to BCI users while controlling a humanoid robot. Participants were asked to steer their robot surrogate and perform a pick-and-place task through BCI-SSVEPs. We found that audio-visual synchrony between footsteps sound and actual humanoid's walk reduces the time required for steering the robot. Thus, auditory feedback congruent with the humanoid actions may improve motor decisions of the BCI's user and help in the feeling of control over it. Our results shed light on the possibility to increase robot's control through the combination of multisensory feedback to a BCI user.

  6. Audio-visual feedback improves the BCI performance in the navigational control of a humanoid robot

    Directory of Open Access Journals (Sweden)

    Emmanuele eTidoni

    2014-06-01

    Full Text Available Advancement in brain computer interfaces (BCI technology allows people to actively interact in the world through surrogates. Controlling real humanoid robots using BCI as intuitively as we control our body represents a challenge for current research in robotics and neuroscience. In order to successfully interact with the environment the brain integrates multiple sensory cues to form a coherent representation of the world. Cognitive neuroscience studies demonstrate that multisensory integration may imply a gain with respect to a single modality and ultimately improve the overall sensorimotor performance. For example, reactivity to simultaneous visual and auditory stimuli may be higher than to the sum of the same stimuli delivered in isolation or in temporal sequence. Yet, knowledge about whether audio-visual integration may improve the control of a surrogate is meager. To explore this issue, we provided human footstep sounds as audio feedback to BCI users while controlling a humanoid robot. Participants were asked to steer their robot surrogate and perform a pick-and-place task through BCI-SSVEPs. We found that audio-visual synchrony between footsteps sound and actual humanoid’s walk reduces the time required for steering the robot. Thus, auditory feedback congruent with the humanoid actions may improve motor decisions of the BCI’s user and help in the feeling of control over it. Our results shed light on the possibility to increase robot’s control through the combination of multisensory feedback to a BCI user.

  7. Teaching and Learning Writing through Providing Teacher’s Feedback

    Directory of Open Access Journals (Sweden)

    Sihem Boubekeur

    2015-11-01

    Full Text Available Teaching English as a foreign language refers to instructing English to learners who are non native speakers. Mastering the language very well does not mean neither that the teacher can instruct writing in a good way; nor the student can compose coherently. Writing is a fundamental skill in both learning and teaching processes; in which EFL students need to master. Yet; the latter is considered as a complex and difficult task in that learners have to explore their thoughts and ideas via communicating on a paper; but clearly. Thus; since learners are required to write extended essays appropriately; they need to be aware of their mistakes via receiving teachers’ feedback which could be an effective strategy that enhances the students’ writing capacities.

  8. Influence of visual feedback in the regulation of arm stiffness following stroke.

    Science.gov (United States)

    Piovesan, Davide; Casadio, Maura; Morasso, Pietro; Giannoni, Psiche

    2011-01-01

    Stroke survivors strongly rely on visual feedback to control their movements, since segmental reflexes are characterized by an inherent hyper-excitability. To test the effect of visual feedback on the modulation of arm stability we estimated the stiffness of the paretic arm in nine stroke survivors during robot mediated therapy, where subjects trained with and without vision. While several studies found a negligible effect in unimpaired individuals, our results highlighted a marked reduction of stroke survivors' arm stiffness in absence of visual feedback.

  9. Neural Substrates of Visual Spatial Coding and Visual Feedback Control for Hand Movements in Allocentric and Target-Directed Tasks

    Science.gov (United States)

    Thaler, Lore; Goodale, Melvyn A.

    2011-01-01

    Neuropsychological evidence suggests that different brain areas may be involved in movements that are directed at visual targets (e.g., pointing or reaching), and movements that are based on allocentric visual information (e.g., drawing or copying). Here we used fMRI to investigate the neural correlates of these two types of movements in healthy volunteers. Subjects (n = 14) performed right hand movements in either a target-directed task (moving a cursor to a target dot) or an allocentric task (moving a cursor to reproduce the distance and direction between two distal target dots) with or without visual feedback about their hand movement. Movements were monitored with an MR compatible touch panel. A whole brain analysis revealed that movements in allocentric conditions led to an increase in activity in the fundus of the left intra-parietal sulcus (IPS), in posterior IPS, in bilateral dorsal premotor cortex (PMd), and in the lateral occipital complex (LOC). Visual feedback in both target-directed and allocentric conditions led to an increase in activity in area MT+, superior parietal–occipital cortex (SPOC), and posterior IPS (all bilateral). In addition, we found that visual feedback affected brain activity differently in target-directed as compared to allocentric conditions, particularly in the pre-supplementary motor area, PMd, IPS, and parieto-occipital cortex. Our results, in combination with previous findings, suggest that the LOC is essential for allocentric visual coding and that SPOC is involved in visual feedback control. The differences in brain activity between target-directed and allocentric visual feedback conditions may be related to behavioral differences in visual feedback control. Our results advance the understanding of the visual coordinate frame used by the LOC. In addition, because of the nature of the allocentric task, our results have relevance for the understanding of neural substrates of magnitude estimation and vector coding of

  10. The Effect of Visual Feedback on Writing Size in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Adriaan R. E. Potgieser

    2015-01-01

    Full Text Available Parkinson’s disease (PD leads to impairment in multiple cognitive domains. Micrographia is a relatively early PD sign of visuomotor dysfunction, characterized by a global reduction in writing size and a decrement in size during writing. Here we aimed to investigate the effect of withdrawal of visual feedback on writing size in patients with PD. Twenty-five patients with non-tremor-dominant PD without cognitive dysfunction and twenty-five age-matched controls had to write a standard sentence with and without visual feedback. We assessed the effect of withdrawal of visual feedback by measuring vertical word size (i, horizontal length of the sentence (ii, and the summed horizontal word length without interspacing (iii, comparing patients with controls. In both patients and controls, writing was significantly larger without visual feedback. This enlargement did not significantly differ between the groups. Smaller handwriting significantly correlated with increased disease severity. Contrary to previous observations that withdrawal of visual feedback caused increased writing size in specifically PD, we did not find differences between patients and controls. Both groups wrote larger without visual feedback, which adds insight in general neuronal mechanisms underlying the balance between feed-forward and feedback in visuomotor control, mechanisms that also hold for grasping movements.

  11. Combined mirror visual and auditory feedback therapy for upper limb phantom pain: a case report

    Directory of Open Access Journals (Sweden)

    Yan Kun

    2011-01-01

    Full Text Available Abstract Introduction Phantom limb sensation and phantom limb pain is a very common issue after amputations. In recent years there has been accumulating data implicating 'mirror visual feedback' or 'mirror therapy' as helpful in the treatment of phantom limb sensation and phantom limb pain. Case presentation We present the case of a 24-year-old Caucasian man, a left upper limb amputee, treated with mirror visual feedback combined with auditory feedback with improved pain relief. Conclusion This case may suggest that auditory feedback might enhance the effectiveness of mirror visual feedback and serve as a valuable addition to the complex multi-sensory processing of body perception in patients who are amputees.

  12. Augmented visual feedback counteracts the effects of surface muscular functional electrical stimulation on physiological tremor

    Science.gov (United States)

    2013-01-01

    Background Recent studies suggest that surface muscular functional electrical stimulation (FES) might suppress neurological upper limb tremor. We assessed its effects on upper limb physiological tremor, which is mainly driven by mechanical-reflex oscillations. We investigated the interaction between FES and augmented visual feedback, since (a) most daily activities are performed using visual cues, and (b) augmented visual feedback exacerbates upper limb tremor. Methods 10 healthy subjects (23.4 ± 7.7 years) performed 2 postural tasks with combinations of FES (4 sites; frequency of stimulation: 30 Hz; pulse width: 300 microsec; range of current delivered 10–34 mAmp) and augmented visual feedback. Results Spectral analysis of tremor showed a decrease of power spectral density to 62.18% (p = 0.01), of the integral in the 8-12 Hz frequency band to 57.67% (p = 0.003), and of tremor root mean square (RMS) to 57.16% (p = 0.002) during FES, without any changes in tremor frequency. Augmented visual feedback blocked the beneficial effect of FES, as confirmed by power spectral analysis (p = 0.01). We found a statistically significant interaction between augmented visual feedback and electrical stimulation (p = 0.039). Conclusions Augmented visual feedback antagonizes the effects of FES on physiological tremor. The absence of changes of peak frequency argues against an effect of FES on mechanical properties of the upper limb. PMID:24063436

  13. A Surgical Robot Teleoperation Framework for Providing Haptic Feedback Incorporating Virtual Environment-Based Guidance

    OpenAIRE

    Munawar, Adnan; Fischer, Gregory

    2016-01-01

    In robot-assisted teleoperated laparoscopic surgeries, the patient side manipulators are controlled via the master manipulators, operated by the surgeon. The current generation of robots approved for laparoscopic surgery lack haptic feedback. In theory, haptic feedback could enhance the surgical procedures by providing a palpable sense of the environment as a function of surgeon’s hands movements. This research presents an overall control framework for haptic feedback on existing robot platfo...

  14. The positive effect of mirror visual feedback on arm control in children with spastic hemiparetic cerebral palsy is dependent on which arm is viewed.

    Science.gov (United States)

    Smorenburg, Ana R P; Ledebt, Annick; Feltham, Max G; Deconinck, Frederik J A; Savelsbergh, Geert J P

    2011-09-01

    Mirror visual feedback has previously been found to reduce disproportionate interlimb variability and neuromuscular activity in the arm muscles in children with Spastic Hemiparetic Cerebral Palsy (SHCP). The aim of the current study was to determine whether these positive effects are generated by the mirror per se (i.e. the illusory perception of two symmetrically moving limbs, irrespective of which arm generates the mirror visual feedback) or by the visual illusion that the impaired arm has been substituted and appears to move with less jerk and in synchrony with the less-impaired arm (i.e. by mirror visual feedback of the less-impaired arm only). Therefore, we compared the effect of mirror visual feedback from the impaired and the less-impaired upper limb on the bimanual coupling and neuromuscular activity during a bimanual coordination task. Children with SHCP were asked to perform a bimanual symmetrical circular movement in three different visual feedback conditions (i.e. viewing the two arms, viewing only one arm, and viewing one arm and its mirror image), combined with two head orientation conditions (i.e. looking from the impaired and looking from the less-impaired body side). It was found that mirror visual feedback resulted in a reduction in the eccentric activity of the Biceps Brachii Brevis in the impaired limb compared to the condition with actual visual feedback from the two arms. More specifically, this effect was exclusive to mirror visual feedback from the less-impaired arm and absent when mirror visual feedback from the impaired arm was provided. Across conditions, the less-impaired arm was the leading limb, and the nature of this coupling was independent from visual condition or head orientation. Also, mirror visual feedback did not affect the intensity of the mean neuromuscular activity or the muscle activity of the Triceps Brachii Longus. It was concluded that the positive effects of mirror visual feedback in children with SHCP are not just the

  15. Volunteer Expert Readers: Drawing on the University Community to Provide Professional Feedback for Engineering Student Writers

    Science.gov (United States)

    Moskovitz, Cary

    2017-01-01

    This paper reports on a 3-year study utilizing a novel approach to providing students in an introductory engineering course with feedback on drafts of course writing projects. In the Volunteer Expert Reader (VER) approach, students are matched with university alumni or employees who have the background to give feedback from the perspective of the…

  16. Auris System: Providing Vibrotactile Feedback for Hearing Impaired Population

    Directory of Open Access Journals (Sweden)

    Felipe Alves Araujo

    2017-01-01

    Full Text Available Deafness, an issue that affects millions of people around the globe, is manifested in different intensities and related to many causes. This impairment negatively affects different aspects of the social life of the deaf people, and music-centered situations (concerts, religious events, etc. are obviously not inviting for them. The Auris System was conceived to provide the musical experimentation for people who have some type of hearing loss. This system is able to extract musical information from audio and create a representation for music pieces using different stimuli, a new media format to be interpreted by other senses than the hearing. In addition, the system defines a testing methodology based on a noninvasive brain activity recording using an electroencephalographic (EEG device. The results of the tests are being used to better understand the human musical cognition, in order to improve the accuracy of the Auris musical representation.

  17. Auris System: Providing Vibrotactile Feedback for Hearing Impaired Population.

    Science.gov (United States)

    Alves Araujo, Felipe; Lima Brasil, Fabricio; Candido Lima Santos, Allison; de Sousa Batista Junior, Luzenildo; Pereira Fonseca Dutra, Savio; Eduardo Coelho Freire Batista, Carlos

    2017-01-01

    Deafness, an issue that affects millions of people around the globe, is manifested in different intensities and related to many causes. This impairment negatively affects different aspects of the social life of the deaf people, and music-centered situations (concerts, religious events, etc.) are obviously not inviting for them. The Auris System was conceived to provide the musical experimentation for people who have some type of hearing loss. This system is able to extract musical information from audio and create a representation for music pieces using different stimuli, a new media format to be interpreted by other senses than the hearing. In addition, the system defines a testing methodology based on a noninvasive brain activity recording using an electroencephalographic (EEG) device. The results of the tests are being used to better understand the human musical cognition, in order to improve the accuracy of the Auris musical representation.

  18. Haptically facilitated bimanual training combined with augmented visual feedback in moderate to severe hemiplegia

    Science.gov (United States)

    Boos, Amy; Qiu, Qinyin; Fluet, Gerard G.; Adamovich, Sergei V.

    2015-01-01

    This study describes the design and feasibility testing of a hand rehabilitation system that provides haptic assistance for hand opening in moderate to severe hemiplegia while subjects attempt to perform bilateral hand movements. A cable-actuated exoskeleton robot assists the subjects in performing impaired finger movements but is controlled by movement of the unimpaired hand. In an attempt to combine the neurophysiological stimuli of bilateral movement and action observation during training, visual feedback of the impaired hand is replaced by feedback of the unimpaired hand, either by using a sagittaly oriented mirror or a virtual reality setup with a pair of virtual hands presented on a flat screen controlled with movement of the unimpaired hand, providing a visual image of their paretic hand moving normally. Joint angles for both hands are measured using data gloves. The system is programmed to maintain a symmetrical relationship between the two hands as they respond to commands to open and close simultaneously. Three persons with moderate to severe hemiplegia secondary to stroke trained with the system for eight, 30 to 60 minute sessions without adverse events. Each demonstrated positive motor adaptations to training. The system was well tolerated by persons with moderate to severe upper extremity hemiplegia. Further testing of its effects on motor ability with a broader range of clinical presentations is indicated. PMID:22254998

  19. Early infant’s use of visual feedback in voluntary reaching for a spatial target

    Directory of Open Access Journals (Sweden)

    Livia Silveira Pogetti

    2013-08-01

    Full Text Available Capacity of using visual feedback by infants at the age of reaching onset has been controversial. In this investigation we assessed movement kinematics in the task of reaching for a toy in 5-month-olds, comparing movements performed with the preferred arm under full vision versus visual occlusion. That comparison was made in consecutive periods of visual occlusion. Analysis of results revealed that visual occlusion led to decreased straightness of arm displacement toward the toy as compared to full vision. Longer periods of occlusion did not augment that effect. These results offer preliminary evidence for use of visual feedback early in infants’ reaching development. Reconciliation of previous and current findings is made by proposing a hybrid mode of feedback processing for manual control reweighting the roles of vision and proprioception as a function of availability of environmental information.

  20. Early infant's use of visual feedback in voluntary reaching for a spatial target

    Science.gov (United States)

    Pogetti, Lívia S.; de Souza, Rosana M.; Tudella, Eloísa; Teixeira, Luis A.

    2013-01-01

    Capacity of using visual feedback by infants at the age of reaching onset has been controversial. In this investigation we assessed movement kinematics in the task of reaching for a toy in 5-month-olds, comparing movements performed with the preferred arm under full vision versus visual occlusion. That comparison was made in consecutive periods of visual occlusion. Analysis of results revealed that visual occlusion led to decreased straightness of arm displacement toward the toy as compared to full vision. Longer periods of occlusion did not augment that effect. These results offer preliminary evidence for use of visual feedback early in infants' reaching development. Reconciliation of previous and current findings is made by proposing a hybrid mode of feedback processing for manual control reweighting the roles of vision and proprioception as a function of availability of environmental information. PMID:23950753

  1. Visual reliance for balance control in older adults persists when visual information is disrupted by artificial feedback delays.

    Directory of Open Access Journals (Sweden)

    Ting Ting Yeh

    Full Text Available Sensory information from our eyes, skin and muscles helps guide and correct balance. Less appreciated, however, is that delays in the transmission of sensory information between our eyes, limbs and central nervous system can exceed several 10s of milliseconds. Investigating how these time-delayed sensory signals influence balance control is central to understanding the postural system. Here, we investigate how delayed visual feedback and cognitive performance influence postural control in healthy young and older adults. The task required that participants position their center of pressure (COP in a fixed target as accurately as possible without visual feedback about their COP location (eyes-open balance, or with artificial time delays imposed on visual COP feedback. On selected trials, the participants also performed a silent arithmetic task (cognitive dual task. We separated COP time series into distinct frequency components using low and high-pass filtering routines. Visual feedback delays affected low frequency postural corrections in young and older adults, with larger increases in postural sway noted for the group of older adults. In comparison, cognitive performance reduced the variability of rapid center of pressure displacements in young adults, but did not alter postural sway in the group of older adults. Our results demonstrate that older adults prioritize vision to control posture. This visual reliance persists even when feedback about the task is delayed by several hundreds of milliseconds.

  2. Visual Reliance for Balance Control in Older Adults Persists When Visual Information Is Disrupted by Artificial Feedback Delays

    Science.gov (United States)

    Balasubramaniam, Ramesh

    2014-01-01

    Sensory information from our eyes, skin and muscles helps guide and correct balance. Less appreciated, however, is that delays in the transmission of sensory information between our eyes, limbs and central nervous system can exceed several 10s of milliseconds. Investigating how these time-delayed sensory signals influence balance control is central to understanding the postural system. Here, we investigate how delayed visual feedback and cognitive performance influence postural control in healthy young and older adults. The task required that participants position their center of pressure (COP) in a fixed target as accurately as possible without visual feedback about their COP location (eyes-open balance), or with artificial time delays imposed on visual COP feedback. On selected trials, the participants also performed a silent arithmetic task (cognitive dual task). We separated COP time series into distinct frequency components using low and high-pass filtering routines. Visual feedback delays affected low frequency postural corrections in young and older adults, with larger increases in postural sway noted for the group of older adults. In comparison, cognitive performance reduced the variability of rapid center of pressure displacements in young adults, but did not alter postural sway in the group of older adults. Our results demonstrate that older adults prioritize vision to control posture. This visual reliance persists even when feedback about the task is delayed by several hundreds of milliseconds. PMID:24614576

  3. Audio-Visual Feedback for Self-monitoring Posture in Ballet Training

    DEFF Research Database (Denmark)

    Knudsen, Esben Winther; Hølledig, Malte Lindholm; Bach-Nielsen, Sebastian Siem

    2017-01-01

    An application for ballet training is presented that monitors the posture position (straightness of the spine and rotation of the pelvis) deviation from the ideal position in real-time. The human skeletal data is acquired through a Microsoft Kinect v2. The movement of the student is mirrored......-coded. In an experiment with 9-12 year-old dance students from a ballet school, comparing the audio-visual feedback modality with no feedback leads to an increase in posture accuracy (p card feedback and expert interviews indicate that the feedback is considered fun and useful...... for training independently from the teacher....

  4. Learning feedback and feedforward control in a mirror-reversed visual environment.

    Science.gov (United States)

    Kasuga, Shoko; Telgen, Sebastian; Ushiba, Junichi; Nozaki, Daichi; Diedrichsen, Jörn

    2015-10-01

    When we learn a novel task, the motor system needs to acquire both feedforward and feedback control. Currently, little is known about how the learning of these two mechanisms relate to each other. In the present study, we tested whether feedforward and feedback control need to be learned separately, or whether they are learned as common mechanism when a new control policy is acquired. Participants were trained to reach to two lateral and one central target in an environment with mirror (left-right)-reversed visual feedback. One group was allowed to make online movement corrections, whereas the other group only received visual information after the end of the movement. Learning of feedforward control was assessed by measuring the accuracy of the initial movement direction to lateral targets. Feedback control was measured in the responses to sudden visual perturbations of the cursor when reaching to the central target. Although feedforward control improved in both groups, it was significantly better when online corrections were not allowed. In contrast, feedback control only adaptively changed in participants who received online feedback and remained unchanged in the group without online corrections. Our findings suggest that when a new control policy is acquired, feedforward and feedback control are learned separately, and that there may be a trade-off in learning between feedback and feedforward controllers. Copyright © 2015 the American Physiological Society.

  5. A flexible postoperative debriefing process can effectively provide formative resident feedback.

    Science.gov (United States)

    Cook, Mackenzie R; Watters, Jennifer M; Barton, Jeffrey S; Kamin, Carol; Brown, Sarah N; Deveney, Karen E; Kiraly, Laszlo N

    2015-05-01

    Providing residents with formative operative feedback is one of the ongoing challenges in modern surgical education. This is highlighted by the recent American Board of Surgery requirement for formal operative assessments. A flexible and adaptable procedure feedback process may allow attending surgeons to provide qualitative and quantitative feedback to residents while encouraging surgeons-in-training to critically reflect on their own performance. We designed and implemented a flexible feedback process in which residents initiated a postoperative feedback discussion and completed a Procedure Feedback Form (PFF) with their supervising attending surgeon. Comparisons were made between the quantitative and qualitative assessments of attending and resident surgeons. Free text statements describing strengths and weaknesses were analyzed using grounded theory with constant comparison. We identified 346 assessments of 48 surgery residents performing 38 different cases. There was good inter-rater reliability between resident and attending surgeons' quantitative assessment, Goodman and Kruskal gamma > 0.65. Key themes identified on qualitative analysis included flow, technique, synthesis/decision, outcomes, knowledge, and communication/attitudes. Subthematic analysis demonstrated that our novel debriefing procedure was easily adaptable to a wide variety of clinical settings and grew more individualized for senior learners. This procedure feedback process is easily adaptable to a wide variety of cases and supports resident self-reflection. The process grows in nuance and complexity with the learner and may serve as a guide for a flexible and widely applicable postoperative feedback process. Copyright © 2015. Published by Elsevier Inc.

  6. Reducing Trunk Compensation in Stroke Survivors: A Randomized Crossover Trial Comparing Visual and Force Feedback Modalities.

    Science.gov (United States)

    Valdés, Bulmaro Adolfo; Schneider, Andrea Nicole; Van der Loos, H F Machiel

    2017-10-01

    To investigate whether the compensatory trunk movements of stroke survivors observed during reaching tasks can be decreased by force and visual feedback, and to examine whether one of these feedback modalities is more efficacious than the other in reducing this compensatory tendency. Randomized crossover trial. University research laboratory. Community-dwelling older adults (N=15; 5 women; mean age, 64±11y) with hemiplegia from nontraumatic hemorrhagic or ischemic stroke (>3mo poststroke), recruited from stroke recovery groups, the research group's website, and the community. In a single session, participants received augmented feedback about their trunk compensation during a bimanual reaching task. Visual feedback (60 trials) was delivered through a computer monitor, and force feedback (60 trials) was delivered through 2 robotic devices. Primary outcome measure included change in anterior trunk displacement measured by motion tracking camera. Secondary outcomes included trunk rotation, index of curvature (measure of straightness of hands' path toward target), root mean square error of hands' movement (differences between hand position on every iteration of the program), completion time for each trial, and posttest questionnaire to evaluate users' experience and system's usability. Both visual (-45.6% [45.8 SD] change from baseline, P=.004) and force (-41.1% [46.1 SD], P=.004) feedback were effective in reducing trunk compensation. Scores on secondary outcome measures did not improve with either feedback modality. Neither feedback condition was superior. Visual and force feedback show promise as 2 modalities that could be used to decrease trunk compensation in stroke survivors during reaching tasks. It remains to be established which one of these 2 feedback modalities is more efficacious than the other as a cue to reduce compensatory trunk movement. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. Visual feedback attenuates mean concentric barbell velocity loss, and improves motivation, competitiveness, and perceived workload in male adolescent athletes.

    Science.gov (United States)

    Weakley, Jonathon Js; Wilson, Kyle M; Till, Kevin; Read, Dale B; Darrall-Jones, Joshua; Roe, Gregory; Phibbs, Padraic J; Jones, Ben

    2017-07-12

    It is unknown whether instantaneous visual feedback of resistance training outcomes can enhance barbell velocity in younger athletes. Therefore, the purpose of this study was to quantify the effects of visual feedback on mean concentric barbell velocity in the back squat, and to identify changes in motivation, competitiveness, and perceived workload. In a randomised-crossover design (Feedback vs. Control) feedback of mean concentric barbell velocity was or was not provided throughout a set of 10 repetitions in the barbell back squat. Magnitude-based inferences were used to assess changes between conditions, with almost certainly greater differences in mean concentric velocity between the Feedback (0.70 ±0.04 m·s) and Control (0.65 ±0.05 m·s) observed. Additionally, individual repetition mean concentric velocity ranged from possibly (repetition number two: 0.79 ±0.04 vs. 0.78 ±0.04 m·s) to almost certainly (repetition number 10: 0.58 ±0.05 vs. 0.49 ±0.05 m·s) greater when provided feedback, while almost certain differences were observed in motivation, competitiveness, and perceived workload, respectively. Providing adolescent male athletes with visual kinematic information while completing resistance training is beneficial for the maintenance of barbell velocity during a training set, potentially enhancing physical performance. Moreover, these improvements were observed alongside increases in motivation, competitiveness and perceived workload providing insight into the underlying mechanisms responsible for the performance gains observed. Given the observed maintenance of barbell velocity during a training set, practitioners can use this technique to manipulate training outcomes during resistance training.

  8. Relative efficacy of various strategies for visual feedback in standing balance activities.

    Science.gov (United States)

    Kennedy, Michael W; Crowell, Charles R; Striegel, Aaron D; Villano, Michael; Schmiedeler, James P

    2013-09-01

    Seventy-nine young, healthy adults were led through static balance and weight-shifting activities in order to study the effects of visual feedback on balance. Based on their performance, the relative effects of various feedback properties were analyzed: (1) arrangement [direct center of pressure (CoP) vs. lateral weight distribution feedback], (2) numbers (presence vs. absence of numeric feedback), and (3) dimensionality (1D vs. 2D CoP information). In the static balance activity, subjects were instructed to maintain equal weight across both feet; in the dynamic weight-shifting activity, subjects were instructed to shift their weight to each displayed target location. For static balance, lateral symmetry and sway were measured by classical parameters using CoP, center of gravity (CoG), and the difference between the two (CoP-CoG). Weight-shifting balance performance was measured using the time required to shift between target CoP positions. Results indicated that feedback arrangement had a significant effect on static sway and dynamic weight shifting, with direct CoP feedback resulting in better balance performance than lateral weight distribution. Also, numbers had a significant effect on static sway, reducing lateral sway compared to feedback without numbers. Finally, 2D CoP feedback resulted in faster performance than 1D CoP feedback in dynamic weight shifting. These results show that altering different properties of visual feedback can have significant effects on resulting balance performance; therefore, proper selection of visual feedback strategy needs to take these effects into consideration.

  9. The Effect of Delayed Visual Feedback on Synchrony Perception in a Tapping Task

    Directory of Open Access Journals (Sweden)

    Mirjam Keetels

    2011-10-01

    Full Text Available Sensory events following a motor action are, within limits, interpreted as a causal consequence of those actions. For example, the clapping of the hands is initiated by the motor system, but subsequently visual, auditory, and tactile information is provided and processed. In the present study we examine the effect of temporal disturbances in this chain of motor-sensory events. Participants are instructed to tap a surface with their finger in synchrony with a chain of 20 sound clicks (ISI 750 ms. We examined the effect of additional visual information on this ‘tap-sound’-synchronization task. During tapping, subjects will see a video of their own tapping hand on a screen in front of them. The video can either be in synchrony with the tap (real-time recording, or can be slightly delayed (∼40–160 ms. In a control condition, no video is provided. We explore whether ‘tap-sound’ synchrony will be shifted as a function of the delayed visual feedback. Results will provide fundamental insights into how the brain preserves a causal interpretation of motor actions and their sensory consequences.

  10. A real-time articulatory visual feedback approach with target presentation for second language pronunciation learning.

    Science.gov (United States)

    Suemitsu, Atsuo; Dang, Jianwu; Ito, Takayuki; Tiede, Mark

    2015-10-01

    Articulatory information can support learning or remediating pronunciation of a second language (L2). This paper describes an electromagnetic articulometer-based visual-feedback approach using an articulatory target presented in real-time to facilitate L2 pronunciation learning. This approach trains learners to adjust articulatory positions to match targets for a L2 vowel estimated from productions of vowels that overlap in both L1 and L2. Training of Japanese learners for the American English vowel /æ/ that included visual training improved its pronunciation regardless of whether audio training was also included. Articulatory visual feedback is shown to be an effective method for facilitating L2 pronunciation learning.

  11. Adaptation of movement endpoints to perturbations of visual feedback

    NARCIS (Netherlands)

    van den Dobbelsteen, John; Brenner, Eli; Smeets, Jeroen B.J.

    We investigated the extent to which humans can quickly adapt their goal-directed arm movements to perturbed feedback. We predicted that the magnitude of adaptation to a changed relationship between vision and kinesthesia would depend on the type of perturbation, being largest when the perturbation

  12. Effect of visual distraction and auditory feedback on patient effort during robot-assisted movement training after stroke

    Directory of Open Access Journals (Sweden)

    Reinkensmeyer David J

    2011-04-01

    Full Text Available Abstract Background Practicing arm and gait movements with robotic assistance after neurologic injury can help patients improve their movement ability, but patients sometimes reduce their effort during training in response to the assistance. Reduced effort has been hypothesized to diminish clinical outcomes of robotic training. To better understand patient slacking, we studied the role of visual distraction and auditory feedback in modulating patient effort during a common robot-assisted tracking task. Methods Fourteen participants with chronic left hemiparesis from stroke, five control participants with chronic right hemiparesis and fourteen non-impaired healthy control participants, tracked a visual target with their arms while receiving adaptive assistance from a robotic arm exoskeleton. We compared four practice conditions: the baseline tracking task alone; tracking while also performing a visual distracter task; tracking with the visual distracter and sound feedback; and tracking with sound feedback. For the distracter task, symbols were randomly displayed in the corners of the computer screen, and the participants were instructed to click a mouse button when a target symbol appeared. The sound feedback consisted of a repeating beep, with the frequency of repetition made to increase with increasing tracking error. Results Participants with stroke halved their effort and doubled their tracking error when performing the visual distracter task with their left hemiparetic arm. With sound feedback, however, these participants increased their effort and decreased their tracking error close to their baseline levels, while also performing the distracter task successfully. These effects were significantly smaller for the participants who used their non-paretic arm and for the participants without stroke. Conclusions Visual distraction decreased participants effort during a standard robot-assisted movement training task. This effect was greater for

  13. Computer-Supported Feedback Message Tailoring for Healthcare Providers in Malawi: Proof-of-Concept

    Science.gov (United States)

    Landis-Lewis, Zach; Douglas, Gerald P; Hochheiser, Harry; Kam, Matthew; Gadabu, Oliver; Bwanali, Mwatha; Jacobson, Rebecca S

    2015-01-01

    Although performance feedback has the potential to help clinicians improve the quality and safety of care, healthcare organizations generally lack knowledge about how this guidance is best provided. In low-resource settings, tools for theory-informed feedback tailoring may enhance limited clinical supervision resources. Our objectives were to establish proof-of-concept for computer-supported feedback message tailoring in Malawi, Africa. We conducted this research in five stages: clinical performance measurement, modeling the influence of feedback on antiretroviral therapy (ART) performance, creating a rule-based message tailoring process, generating tailored messages for recipients, and finally analysis of performance and message tailoring data. We retrospectively generated tailored messages for 7,448 monthly performance reports from 11 ART clinics. We found that tailored feedback could be routinely generated for four guideline-based performance indicators, with 35% of reports having messages prioritized to optimize the effect of feedback. This research establishes proof-of-concept for a novel approach to improving the use of clinical performance feedback in low-resource settings and suggests possible directions for prospective evaluations comparing alternative designs of feedback messages. PMID:26958217

  14. Active training and driving-specific feedback improve older drivers' visual search prior to lane changes.

    Science.gov (United States)

    Lavallière, Martin; Simoneau, Martin; Tremblay, Mathieu; Laurendeau, Denis; Teasdale, Normand

    2012-03-02

    Driving retraining classes may offer an opportunity to attenuate some effects of aging that may alter driving skills. Unfortunately, there is evidence that classroom programs (driving refresher courses) do not improve the driving performance of older drivers. The aim of the current study was to evaluate if simulator training sessions with video-based feedback can modify visual search behaviors of older drivers while changing lanes in urban driving. In order to evaluate the effectiveness of the video-based feedback training, 10 older drivers who received a driving refresher course and feedback about their driving performance were tested with an on-road standardized evaluation before and after participating to a simulator training program (Feedback group). Their results were compared to a Control group (12 older drivers) who received the same refresher course and in-simulator active practice as the Feedback group without receiving driving-specific feedback. After attending the training program, the Control group showed no increase in the frequency of the visual inspection of three regions of interests (rear view and left side mirrors, and blind spot). In contrast, for the Feedback group, combining active training and driving-specific feedbacks increased the frequency of blind spot inspection by 100% (32.3 to 64.9% of verification before changing lanes). These results suggest that simulator training combined with driving-specific feedbacks helped older drivers to improve their visual inspection strategies, and that in-simulator training transferred positively to on-road driving. In order to be effective, it is claimed that driving programs should include active practice sessions with driving-specific feedbacks. Simulators offer a unique environment for developing such programs adapted to older drivers' needs.

  15. Active training and driving-specific feedback improve older drivers' visual search prior to lane changes

    Directory of Open Access Journals (Sweden)

    Lavallière Martin

    2012-03-01

    Full Text Available Abstract Background Driving retraining classes may offer an opportunity to attenuate some effects of aging that may alter driving skills. Unfortunately, there is evidence that classroom programs (driving refresher courses do not improve the driving performance of older drivers. The aim of the current study was to evaluate if simulator training sessions with video-based feedback can modify visual search behaviors of older drivers while changing lanes in urban driving. Methods In order to evaluate the effectiveness of the video-based feedback training, 10 older drivers who received a driving refresher course and feedback about their driving performance were tested with an on-road standardized evaluation before and after participating to a simulator training program (Feedback group. Their results were compared to a Control group (12 older drivers who received the same refresher course and in-simulator active practice as the Feedback group without receiving driving-specific feedback. Results After attending the training program, the Control group showed no increase in the frequency of the visual inspection of three regions of interests (rear view and left side mirrors, and blind spot. In contrast, for the Feedback group, combining active training and driving-specific feedbacks increased the frequency of blind spot inspection by 100% (32.3 to 64.9% of verification before changing lanes. Conclusions These results suggest that simulator training combined with driving-specific feedbacks helped older drivers to improve their visual inspection strategies, and that in-simulator training transferred positively to on-road driving. In order to be effective, it is claimed that driving programs should include active practice sessions with driving-specific feedbacks. Simulators offer a unique environment for developing such programs adapted to older drivers' needs.

  16. Real-time visual feedback of COM and COP motion properties differentially modifies postural control structures.

    Science.gov (United States)

    Kilby, Melissa C; Molenaar, Peter C M; Slobounov, Semyon M; Newell, Karl M

    2017-01-01

    The experiment was setup to investigate the control of human quiet standing through the manipulation of augmented visual information feedback of selective properties of the motion of two primary variables in postural control: center of pressure (COP) and center of mass (COM). Five properties of feedback information were contrasted to a no feedback dual-task (watching a movie) control condition to determine the impact of visual real-time feedback on the coordination of the joint motions in postural control in both static and dynamic one-leg standing postures. The feedback information included 2D COP or COM position and macro variables derived from the COP and COM motions, namely virtual time-to-contact (VTC) and the COP-COM coupling. The findings in the static condition showed that the VTC and COP-COM coupling feedback conditions decreased postural motion more than the 2D COP or COM positional information. These variables also induced larger sway amplitudes in the dynamic condition showing a more progressive search strategy in exploring the stability limits. Canonical correlation analysis (CCA) found that COP-COM coupling contributed less than the other feedback variables to the redundancy of the system reflected in the common variance between joint motions and properties of sway motion. The COP-COM coupling had the lowest weighting of the motion properties to redundancy under the feedback conditions but overall the qualitative pattern of the joint motion structures was preserved within the respective static and dynamic balance conditions.

  17. Imposed visual feedback delay of an action changes mass perception based on the sensory prediction error

    Directory of Open Access Journals (Sweden)

    Takuya eHonda

    2013-10-01

    Full Text Available While performing an action, the timing of when the sensory feedback is given can be used to establish the causal link between the action and its consequence. It has been shown that delaying the visual feedback while carrying an object makes people feel the mass of the object to be greater, suggesting that the feedback timing can also impact the perceived quality of an external object. In this study, we investigated the origin of the feedback timing information that influences the mass perception of the external object.Participants made a straight reaching movement while holding a manipulandum. The movement of the manipulandum was presented as a cursor movement on a monitor. In Experiment 1, various delays were imposed between the actual trajectory and the cursor movement. The participants’ perceived mass of the manipulandum significantly increased as the delay increased to 400 ms, but this gain did not reach significance when the delay was 800 ms. This suggests the existence of a temporal tuning mechanism for incorporating the visual feedback into the perception of mass. In Experiment 2, we examined whether the increased mass perception during the visual delay was due to the prediction error of the visual consequence of an action or to the actual delay of the feedback itself. After the participants adapted to the feedback delay, the perceived mass of the object became lighter than before, indicating that updating the temporal prediction model for the visual consequence diminishes the overestimation of the object’s mass. We propose that the misattribution of the visual delay into mass perception is induced by the sensorimotor prediction error, possibly when the amount of delay (error is within the range that can reasonably include the consequence of an action.

  18. A qualitative study on feedback provided by students in nurse education.

    Science.gov (United States)

    Chan, Zenobia C Y; Stanley, David John; Meadus, Robert J; Chien, Wai Tong

    2017-08-01

    This study aims to help nurse educators/academics understand the perspectives and expectations of students providing their feedback to educators about teaching performance and subject quality. The aim of this study is to reveal students' voices regarding their feedback in nurse education in order to shed light on how the current student feedback practice may be modified. A qualitative study using focus group inquiry. Convenience sampling was adopted and participants recruited from one school of nursing in Hong Kong. A total of 66 nursing students from two pre-registration programs were recruited for seven focus group interviews: one group of Year 1 students (n=21), two groups of Year 3 students (n=27), and four groups of Final Year students (n=18). The interviews were guided by a semi-structured interview guideline and the interview narratives were processed through content analysis. The trustworthiness of this study was guaranteed through peer checking, research meetings, and an audit trail. The participants' privacy was protected throughout the study. Four core themes were discerned based on the narratives of the focus group interviews: (1) "timing of collecting feedback at more than one time point"; (2) "modify the questions being asked in collecting student feedback"; (3) "are electronic means of collecting feedback good enough?; and (4) "what will be next for student feedback?". This study is significant in the following three domains: 1) it contributed to student feedback because it examined the issue from a student's perspective; 2) it explored the timing and channels for collecting feedback from the students' point of view; and 3) it showed the preferred uses of student feedback. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  19. A Systematic Review of the Literature on Parenting of Young Children with Visual Impairments and the Adaptions for Video-Feedback Intervention to Promote Positive Parenting (VIPP)

    NARCIS (Netherlands)

    van den Broek, Ellen G. C.; van Eijden, Ans J P M; Overbeek, Mathilde M.; Kef, Sabina; Sterkenburg, Paula S.; Schuengel, Carlo

    Secure parent-child attachment may help children to overcome the challenges of growing up with a visual or visual-and-intellectual impairment. A large literature exists that provides a blueprint for interventions that promote parental sensitivity and secure attachment. The Video-feedback

  20. Can real-time visual feedback during gait retraining reduce metabolic demand for individuals with transtibial amputation?

    Directory of Open Access Journals (Sweden)

    Elizabeth Russell Esposito

    Full Text Available The metabolic demand of walking generally increases following lower extremity amputation. This study used real-time visual feedback to modify biomechanical factors linked to an elevated metabolic demand of walking in individuals with transtibial amputation. Eight persons with unilateral, traumatic transtibial amputation and 8 uninjured controls participated. Two separate bouts of real-time visual feedback were provided during a single session of gait retraining to reduce 1 center of mass sway and 2 thigh muscle activation magnitudes and duration. Baseline and post-intervention data were collected. Metabolic rate, heart rate, frontal plane center of mass sway, quadriceps and hamstrings muscle activity, and co-contraction indices were evaluated during steady state walking at a standardized speed. Visual feedback successfully decreased center of mass sway 12% (p = 0.006 and quadriceps activity 12% (p = 0.041; however, thigh muscle co-contraction indices were unchanged. Neither condition significantly affected metabolic rate during walking and heart rate increased with center-of-mass feedback. Metabolic rate, center of mass sway, and integrated quadriceps muscle activity were all not significantly different from controls. Attempts to modify gait to decrease metabolic demand may actually adversely increase the physiological effort of walking in individuals with lower extremity amputation who are young, active and approximate metabolic rates of able-bodied adults.

  1. Can real-time visual feedback during gait retraining reduce metabolic demand for individuals with transtibial amputation?

    Science.gov (United States)

    Russell Esposito, Elizabeth; Choi, Harmony S; Darter, Benjamin J; Wilken, Jason M

    2017-01-01

    The metabolic demand of walking generally increases following lower extremity amputation. This study used real-time visual feedback to modify biomechanical factors linked to an elevated metabolic demand of walking in individuals with transtibial amputation. Eight persons with unilateral, traumatic transtibial amputation and 8 uninjured controls participated. Two separate bouts of real-time visual feedback were provided during a single session of gait retraining to reduce 1) center of mass sway and 2) thigh muscle activation magnitudes and duration. Baseline and post-intervention data were collected. Metabolic rate, heart rate, frontal plane center of mass sway, quadriceps and hamstrings muscle activity, and co-contraction indices were evaluated during steady state walking at a standardized speed. Visual feedback successfully decreased center of mass sway 12% (p = 0.006) and quadriceps activity 12% (p = 0.041); however, thigh muscle co-contraction indices were unchanged. Neither condition significantly affected metabolic rate during walking and heart rate increased with center-of-mass feedback. Metabolic rate, center of mass sway, and integrated quadriceps muscle activity were all not significantly different from controls. Attempts to modify gait to decrease metabolic demand may actually adversely increase the physiological effort of walking in individuals with lower extremity amputation who are young, active and approximate metabolic rates of able-bodied adults.

  2. Relationship between subjective test feedback provided by high-school athletes during computer-based assessment of baseline cognitive functioning and self-reported symptoms.

    Science.gov (United States)

    Schatz, Philip; Neidzwski, Katherine; Moser, Rosemarie Scolaro; Karpf, Robin

    2010-06-01

    Subjective feedback about distractions or problems encountered during computerized assessment was provided by 538 out of a pool of 1659 high-school athletes who completed baseline testing using ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing). Three types of feedback were included: (a) environmental, (b) computer-based (mechanical), and (c) instruction-based (associated with difficulty understanding test instructions). One-way analyses of variance were conducted and revealed relationships between greater symptom reporting and any type of feedback, environmental feedback, and instruction-based feedback. Increased symptom reporting was noted for female students. Additional relationships were noted between providing computer-based feedback and faster reaction time; and between history of concussion and providing instruction-based feedback. Athletes endorsing more symptoms at baseline scored significantly worse on ImPACT, as reflected in decreased visual memory performance. Results suggest that feedback provided during computerized assessment may yield information about symptom reporting and test-taking style, which may also be of particular interpretive utility when athletes minimize their symptoms.

  3. Influence of visual feedback on human task performance in ITER remote handling

    Energy Technology Data Exchange (ETDEWEB)

    Schropp, Gwendolijn Y.R., E-mail: g.schropp@heemskerk-innovative.nl [Utrecht University, Utrecht (Netherlands); Heemskerk Innovative Technology, Noordwijk (Netherlands); Heemskerk, Cock J.M. [Heemskerk Innovative Technology, Noordwijk (Netherlands); Kappers, Astrid M.L.; Tiest, Wouter M. Bergmann [Helmholtz Institute-Utrecht University, Utrecht (Netherlands); Elzendoorn, Ben S.Q. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM/FOM, Partner in the Trilateral Euregio Clusterand ITER-NL, PO box 1207, 3430 BE Nieuwegein (Netherlands); Bult, David [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM/FOM, Partner in the Trilateral Euregio Clusterand ITER-NL, PO box 1207, 3430 BE Nieuwegein (Netherlands)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer The performance of human operators in an ITER-like test facility for remote handling. Black-Right-Pointing-Pointer Different sources of visual feedback influence how fast one can complete a maintenance task. Black-Right-Pointing-Pointer Insights learned could be used in design of operator work environment or training procedures. - Abstract: In ITER, maintenance operations will be largely performed by remote handling (RH). Before ITER can be put into operation, safety regulations and licensing authorities require proof of maintainability for critical components. Part of the proof will come from using standard components and procedures. Additional verification and validation is based on simulation and hardware tests in 1:1 scale mockups. The Master Slave manipulator system (MS2) Benchmark Product was designed to implement a reference set of maintenance tasks representative for ITER remote handling. Experiments were performed with two versions of the Benchmark Product. In both experiments, the quality of visual feedback varied by exchanging direct view with indirect view (using video cameras) in order to measure and analyze its impact on human task performance. The first experiment showed that both experienced and novice RH operators perform a simple task significantly better with direct visual feedback than with camera feedback. A more complex task showed a large variation in results and could not be completed by many novice operators. Experienced operators commented on both the mechanical design and visual feedback. In a second experiment, a more elaborate task was tested on an improved Benchmark product. Again, the task was performed significantly faster with direct visual feedback than with camera feedback. In post-test interviews, operators indicated that they regarded the lack of 3D perception as the primary factor hindering their performance.

  4. Nonimmersive virtual reality mirror visual feedback therapy and its application for the treatment of complex regional pain syndrome: an open-label pilot study.

    Science.gov (United States)

    Sato, Kenji; Fukumori, Satoshi; Matsusaki, Takashi; Maruo, Tomoko; Ishikawa, Shinichi; Nishie, Hiroyuki; Takata, Ken; Mizuhara, Hiroaki; Mizobuchi, Satoshi; Nakatsuka, Hideki; Matsumi, Masaki; Gofuku, Akio; Yokoyama, Masataka; Morita, Kiyoshi

    2010-04-01

    Chronic pain conditions such as phantom limb pain and complex regional pain syndrome are difficult to treat, and traditional pharmacological treatment and invasive neural block are not always effective. Plasticity in the central nervous system occurs in these conditions and may be associated with pain. Mirror visual feedback therapy aims to restore normal cortical organization and is applied in the treatment of chronic pain conditions. However, not all patients benefit from this treatment. Virtual reality technology is increasingly attracting attention for medical application, including as an analgesic modality. An advanced mirror visual feedback system with virtual reality technology may have increased analgesic efficacy and benefit a wider patient population. In this preliminary work, we developed a virtual reality mirror visual feedback system and applied it to the treatment of complex regional pain syndrome. A small open-label case series. Five patients with complex regional pain syndrome received virtual reality mirror visual feedback therapy once a week for five to eight sessions on an outpatient basis. Patients were monitored for continued medication use and pain intensity. Four of the five patients showed >50% reduction in pain intensity. Two of these patients ended their visits to our pain clinic after five sessions. Our results indicate that virtual reality mirror visual feedback therapy is a promising alternative treatment for complex regional pain syndrome. Further studies are necessary before concluding that analgesia provided from virtual reality mirror visual feedback therapy is the result of reversing maladaptive changes in pain perception.

  5. Visual Feedback Dominates the Sense of Agency for Brain-Machine Actions

    Science.gov (United States)

    Evans, Nathan; Gale, Steven; Schurger, Aaron; Blanke, Olaf

    2015-01-01

    Recent advances in neuroscience and engineering have led to the development of technologies that permit the control of external devices through real-time decoding of brain activity (brain-machine interfaces; BMI). Though the feeling of controlling bodily movements (sense of agency; SOA) has been well studied and a number of well-defined sensorimotor and cognitive mechanisms have been put forth, very little is known about the SOA for BMI-actions. Using an on-line BMI, and verifying that our subjects achieved a reasonable level of control, we sought to describe the SOA for BMI-mediated actions. Our results demonstrate that discrepancies between decoded neural activity and its resultant real-time sensory feedback are associated with a decrease in the SOA, similar to SOA mechanisms proposed for bodily actions. However, if the feedback discrepancy serves to correct a poorly controlled BMI-action, then the SOA can be high and can increase with increasing discrepancy, demonstrating the dominance of visual feedback on the SOA. Taken together, our results suggest that bodily and BMI-actions rely on common mechanisms of sensorimotor integration for agency judgments, but that visual feedback dominates the SOA in the absence of overt bodily movements or proprioceptive feedback, however erroneous the visual feedback may be. PMID:26066840

  6. Attentional capture? Synchronized feedback signals from the isthmi boost retinal signals to higher visual areas.

    Science.gov (United States)

    Marín, Gonzalo J; Durán, Ernesto; Morales, Cristian; González-Cabrera, Cristian; Sentis, Elisa; Mpodozis, Jorge; Letelier, Juan Carlos

    2012-01-18

    When a salient object in the visual field captures attention, the neural representation of that object is enhanced at the expense of competing stimuli. How neural activity evoked by a salient stimulus evolves to take precedence over the neural activity evoked by other stimuli is a matter of intensive investigation. Here, we describe in pigeons (Columba livia) how retinal inputs to the optic tectum (TeO, superior colliculus in mammals), triggered by moving stimuli, are selectively relayed on to the rotundus (Rt, caudal pulvinar) in the thalamus, and to its pallial target, the entopallium (E, extrastriate cortex). We show that two satellite nuclei of the TeO, the nucleus isthmi parvocelullaris (Ipc) and isthmi semilunaris (SLu), send synchronized feedback signals across tectal layers. Preventing the feedback from Ipc but not from SLu to a tectal location suppresses visual responses to moving stimuli from the corresponding region of visual space in all Rt subdivisions. In addition, the bursting feedback from the Ipc imprints a bursting rhythm on the visual signals, such that the visual responses of the Rt and the E acquire a bursting modulation significantly synchronized to the feedback from Ipc. As the Ipc feedback signals are selected by competitive interactions, the visual responses within the receptive fields in the Rt tend to synchronize with the tectal location receiving the "winning" feedback from Ipc. We propose that this selective transmission of afferent activity combined with the cross-regional synchronization of the areas involved represents a bottom-up mechanism by which salient stimuli capture attention.

  7. Tactile Gap Detection Deteriorates during Bimanual Symmetrical Movements under Mirror Visual Feedback.

    Directory of Open Access Journals (Sweden)

    Janet H Bultitude

    Full Text Available It has been suggested that incongruence between signals for motor intention and sensory input can cause pain and other sensory abnormalities. This claim is supported by reports that moving in an environment of induced sensorimotor conflict leads to elevated pain and sensory symptoms in those with certain painful conditions. Similar procedures can lead to reports of anomalous sensations in healthy volunteers too. In the present study, we used mirror visual feedback to investigate the effects of sensorimotor incongruence on responses to stimuli that arise from sources external to the body, in particular, touch. Incongruence between the sensory and motor signals for the right arm was manipulated by having the participants make symmetrical or asymmetrical movements while watching a reflection of their left arm in a parasagittal mirror, or the left hand surface of a similarly positioned opaque board. In contrast to our prediction, sensitivity to the presence of gaps in tactile stimulation of the right forearm was not reduced when participants made asymmetrical movements during mirror visual feedback, as compared to when they made symmetrical or asymmetrical movements with no visual feedback. Instead, sensitivity was reduced when participants made symmetrical movements during mirror visual feedback relative to the other three conditions. We suggest that small discrepancies between sensory and motor information, as they occur during mirror visual feedback with symmetrical movements, can impair tactile processing. In contrast, asymmetrical movements with mirror visual feedback may not impact tactile processing because the larger discrepancies between sensory and motor information may prevent the integration of these sources of information. These results contrast with previous reports of anomalous sensations during exposure to both low and high sensorimotor conflict, but are nevertheless in agreement with a forward model interpretation of perceptual

  8. Effects of visual feedback-induced variability on motor learning of handrim wheelchair propulsion.

    Science.gov (United States)

    Leving, Marika T; Vegter, Riemer J K; Hartog, Johanneke; Lamoth, Claudine J C; de Groot, Sonja; van der Woude, Lucas H V

    2015-01-01

    It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process. 17 Participants received visual feedback-based practice (feedback group) and 15 participants received regular practice (natural learning group). Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1st 4-min block) and optimize it in the prescribed direction (2nd 4-min block). To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability. The feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group. These results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not always appear

  9. The Influence of Mirror-Visual Feedback on Training-Induced Motor Performance Gains in the Untrained Hand.

    Directory of Open Access Journals (Sweden)

    Paola Reissig

    Full Text Available The well-documented observation of bilateral performance gains following unilateral motor training, a phenomenon known as cross-limb transfer, has important implications for rehabilitation. It has recently been shown that provision of a mirror image of the active hand during unilateral motor training has the capacity to enhance the efficacy of this phenomenon when compared to training without augmented visual feedback (i.e., watching the passive hand, possibly via action observation effects [1]. The current experiment was designed to confirm whether mirror-visual feedback (MVF during motor training can indeed elicit greater performance gains in the untrained hand compared to more standard visual feedback (i.e., watching the active hand. Furthermore, discussing the mechanisms underlying any such MVF-induced behavioural effects, we suggest that action observation and the cross-activation hypothesis may both play important roles in eliciting cross-limb transfer. Eighty participants practiced a fast-as-possible two-ball rotation task with their dominant hand. During training, three different groups were provided with concurrent visual feedback of the active hand, inactive hand or a mirror image of the active hand with a fourth control group receiving no training. Pre- and post-training performance was measured in both hands. MVF did not increase the extent of training-induced performance changes in the untrained hand following unilateral training above and beyond those observed for other types of feedback. The data are consistent with the notion that cross-limb transfer, when combined with MVF, is mediated by cross-activation with action observation playing a less unique role than previously suggested. Further research is needed to replicate the current and previous studies to determine the clinical relevance and potential benefits of MVF for cases that, due to the severity of impairment, rely on unilateral training programmes of the unaffected limb

  10. Manipulating the fidelity of lower extremity visual feedback to identify obstacle negotiation strategies in immersive virtual reality.

    Science.gov (United States)

    Kim, Aram; Zhou, Zixuan; Kretch, Kari S; Finley, James M

    2017-07-01

    The ability to successfully navigate obstacles in our environment requires integration of visual information about the environment with estimates of our body's state. Previous studies have used partial occlusion of the visual field to explore how information about the body and impending obstacles are integrated to mediate a successful clearance strategy. However, because these manipulations often remove information about both the body and obstacle, it remains to be seen how information about the lower extremities alone is utilized during obstacle crossing. Here, we used an immersive virtual reality (VR) interface to explore how visual feedback of the lower extremities influences obstacle crossing performance. Participants wore a head-mounted display while walking on treadmill and were instructed to step over obstacles in a virtual corridor in four different feedback trials. The trials involved: (1) No visual feedback of the lower extremities, (2) an endpoint-only model, (3) a link-segment model, and (4) a volumetric multi-segment model. We found that the volumetric model improved success rate, placed their trailing foot before crossing and leading foot after crossing more consistently, and placed their leading foot closer to the obstacle after crossing compared to no model. This knowledge is critical for the design of obstacle negotiation tasks in immersive virtual environments as it may provide information about the fidelity necessary to reproduce ecologically valid practice environments.

  11. Effects of angular gain transformations between movement and visual feedback on coordination performance in unimanual circling

    Directory of Open Access Journals (Sweden)

    Martina eRieger

    2014-03-01

    Full Text Available Tool actions are characterized by a transformation (of spatio-temporal and/or force-related characteristics between movements and their resulting consequences in the environment. This transformation has to be taken into account, when planning and executing movement and its existence may affect performance. In the present study we investigated how angular gain transformations between movement and visual feedback during circling movements affect coordination performance. Participants coordinated the visual feedback (feedback dot with a continuously circling stimulus (stimulus dot on a computer screen in order to produce mirror symmetric trajectories of them. The movement angle was multiplied by a gain factor (0.5 to 2; 9 levels before it was presented on the screen. Thus, the angular gain transformations changed the spatio-temporal relationship between the movement and its feedback in visual space, and resulted in a non-constant mapping of movement to feedback positions. Coordination performance was best with gain = 1. With high gains the feedback dot was in lead of the stimulus dot, with small gains it lagged behind. Anchoring (reduced movement variability occurred when the two trajectories were close to each other. Awareness of the transformation depended on the deviation of the gain from 1. In conclusion, the size of an angular gain transformation as well as its mere presence influence performance in a situation in which the mapping of movement positions to visual feedback positions is not constant. When designing machines or tools that involve transformations between movements and their external consequences, one should be aware that the mere presence of angular gains may result in performance decrements and that there can be flaws in the representation of the transformation.

  12. Providing Behavioral Feedback to Students in an Alternative High School Setting

    Science.gov (United States)

    Whitcomb, Sara A.; Hefter, Sheera; Barker, Elizabeth

    2016-01-01

    This column provides an example method for improving the consistency and quality of daily behavioral feedback provided to students in an alternative high school setting. Often, homeroom or advisory periods are prime points in the day for students to review their behavior from the previous day and set goals for a successful day to come. The method…

  13. Dual Delayed Feedback Provides Sensitivity and Robustness to the NF-κB Signaling Module

    Science.gov (United States)

    Kearns, Jeffrey D.; Hasty, Jeff; Hoffmann, Alexander; Tsimring, Lev S.

    2013-01-01

    Many cellular stress-responsive signaling systems exhibit highly dynamic behavior with oscillatory features mediated by delayed negative feedback loops. What remains unclear is whether oscillatory behavior is the basis for a signaling code based on frequency modulation (FM) or whether the negative feedback control modules have evolved to fulfill other functional requirements. Here, we use experimentally calibrated computational models to interrogate the negative feedback loops that regulate the dynamic activity of the transcription factor NF-B. Linear stability analysis of the model shows that oscillatory frequency is a hard-wired feature of the primary negative feedback loop and not a function of the stimulus, thus arguing against an FM signaling code. Instead, our modeling studies suggest that the two feedback loops may be tuned to provide for rapid activation and inactivation capabilities for transient input signals of a wide range of durations; by minimizing late phase oscillations response durations may be fine-tuned in a graded rather than quantized manner. Further, in the presence of molecular noise the dual delayed negative feedback system minimizes stochastic excursions of the output to produce a robust NF-B response. PMID:23825938

  14. Neuronal correlates of continuous manual tracking under varying visual movement feedback in a virtual reality environment.

    Science.gov (United States)

    Limanowski, Jakub; Kirilina, Evgeniya; Blankenburg, Felix

    2017-02-01

    To accurately guide one's actions online, the brain predicts sensory action feedback ahead of time based on internal models, which can be updated by sensory prediction errors. The underlying operations can be experimentally investigated in sensorimotor adaptation tasks, in which moving under perturbed sensory action feedback requires internal model updates. Here we altered healthy participants' visual hand movement feedback in a virtual reality setup, while assessing brain activity with functional magnetic resonance imaging (fMRI). Participants tracked a continually moving virtual target object with a photorealistic, three-dimensional (3D) virtual hand controlled online via a data glove. During the continuous tracking task, the virtual hand's movements (i.e., visual movement feedback) were repeatedly periodically delayed, which participants had to compensate for to maintain accurate tracking. This realistic task design allowed us to simultaneously investigate processes likely operating at several levels of the brain's motor control hierarchy. FMRI revealed that the length of visual feedback delay was parametrically reflected by activity in the inferior parietal cortex and posterior temporal cortex. Unpredicted changes in visuomotor mapping (at transitions from synchronous to delayed visual feedback periods or vice versa) activated biological motion-sensitive regions in the lateral occipitotemporal cortex (LOTC). Activity in the posterior parietal cortex (PPC), focused on the contralateral anterior intraparietal sulcus (aIPS), correlated with tracking error, whereby this correlation was stronger in participants with higher tracking performance. Our results are in line with recent proposals of a wide-spread cortical motor control hierarchy, where temporoparietal regions seem to evaluate visuomotor congruence and thus possibly ground a self-attribution of movements, the LOTC likely processes early visual prediction errors, and the aIPS computes action goal errors and

  15. Providing physicians with feedback on how they supervise students during patient contacts.

    Science.gov (United States)

    Dolmans, D H J M; Wolfhagen, H A P; Gerver, W J; De Grave, W; Scherpbier, A J J A

    2004-08-01

    In this descriptive study an instrument is presented that has been developed to provide physicians with feedback about their strengths and weaknesses in facilitating student learning during patient contacts. The instrument is strongly theory based, i.e. it is based on current general theories of context-bound learning environments, and forms of facilitation promoting transfer of knowledge to actual professional practice. In addition, it has been developed in cooperation with physicians supervising students during patient contacts. The authors have shown how physicians can be provided with individualized feedback on their performance in supervising students during patient contacts.

  16. The effects of augmented visual feedback during balance training in Parkinson's disease: study design of a randomized clinical trial.

    Science.gov (United States)

    van den Heuvel, Maarten R C; van Wegen, Erwin E H; de Goede, Cees J T; Burgers-Bots, Ingrid A L; Beek, Peter J; Daffertshofer, Andreas; Kwakkel, Gert

    2013-10-04

    Patients with Parkinson's disease often suffer from reduced mobility due to impaired postural control. Balance exercises form an integral part of rehabilitative therapy but the effectiveness of existing interventions is limited. Recent technological advances allow for providing enhanced visual feedback in the context of computer games, which provide an attractive alternative to conventional therapy. The objective of this randomized clinical trial is to investigate whether a training program capitalizing on virtual-reality-based visual feedback is more effective than an equally-dosed conventional training in improving standing balance performance in patients with Parkinson's disease. Patients with idiopathic Parkinson's disease will participate in a five-week balance training program comprising ten treatment sessions of 60 minutes each. Participants will be randomly allocated to (1) an experimental group that will receive balance training using augmented visual feedback, or (2) a control group that will receive balance training in accordance with current physical therapy guidelines for Parkinson's disease patients. Training sessions consist of task-specific exercises that are organized as a series of workstations. Assessments will take place before training, at six weeks, and at twelve weeks follow-up. The functional reach test will serve as the primary outcome measure supplemented by comprehensive assessments of functional balance, posturography, and electroencephalography. We hypothesize that balance training based on visual feedback will show greater improvements on standing balance performance than conventional balance training. In addition, we expect that learning new control strategies will be visible in the co-registered posturographic recordings but also through changes in functional connectivity.

  17. Technology-Assisted Rehabilitation of Writing Skills in Parkinson's Disease: Visual Cueing versus Intelligent Feedback.

    Science.gov (United States)

    Nackaerts, Evelien; Nieuwboer, Alice; Farella, Elisabetta

    2017-01-01

    Recent research showed that visual cueing can have both beneficial and detrimental effects on handwriting of patients with Parkinson's disease (PD) and healthy controls depending on the circumstances. Hence, using other sensory modalities to deliver cueing or feedback may be a valuable alternative. Therefore, the current study compared the effects of short-term training with either continuous visual cues or intermittent intelligent verbal feedback. Ten PD patients and nine healthy controls were randomly assigned to one of these training modes. To assess transfer of learning, writing performance was assessed in the absence of cueing and feedback on both trained and untrained writing sequences. The feedback pen and a touch-sensitive writing tablet were used for testing. Both training types resulted in improved writing amplitudes for the trained and untrained sequences. In conclusion, these results suggest that the feedback pen is a valuable tool to implement writing training in a tailor-made fashion for people with PD. Future studies should include larger sample sizes and different subgroups of PD for long-term training with the feedback pen.

  18. Stochastic two-delay differential model of delayed visual feedback effects on postural dynamics

    NARCIS (Netherlands)

    Boulet, J.; Balasubramaniam, R.; Daffertshofer, A.; Longtin, A.

    2010-01-01

    We report on experiments and modelling involving the 'visuo-postural control loop' in the upright stance. We experimentally manipulated an artificial delay to the visual feedback during standing, presented at delays ranging from 0 to 1 s in increments of 250 ms. Using stochastic delay differential

  19. Interactive Football-Training Based on Rebounders with Hit Position Sensing and Audio-Visual Feedback

    DEFF Research Database (Denmark)

    Jensen, Mads Møller; Grønbæk, Kaj; Thomassen, Nikolaj

    2014-01-01

    -visual feedback. Football Lab enables the creation of novel training games, which aim to improve players’ technical skills, and simultaneously function as a tool for measuring player performance and development over time. A logging of the Football Lab was conducted through 92 weeks, where the platform...

  20. A dual visual-local feedback model of the vergence eye movement system

    NARCIS (Netherlands)

    Erkelens, C.J.|info:eu-repo/dai/nl/069562296

    2011-01-01

    Pure vergence movements are the eye movements that we make when we change our binocular fixation between targets differing in distance but not in direction relative to the head. Pure vergence is slow and controlled by visual feedback. Saccades are the rapid eye movements that we make between targets

  1. Promoting Increased Pitch Variation in Oral Presentations with Transient Visual Feedback

    Directory of Open Access Journals (Sweden)

    Rebecca Hincks

    2009-10-01

    Full Text Available This paper investigates learner response to a novel kind of intonation feedback generated from speech analysis. Instead of displays of pitch curves, our feedback is flashing lights that show how much pitch variation the speaker has produced. The variable used to generate the feedback is the standard deviation of fundamental frequency as measured in semitones. Flat speech causes the system to show yellow lights, while more expressive speech that has used pitch to give focus to any part of an utterance generates green lights. Participants in the study were 14 Chinese students of English at intermediate and advanced levels. A group that received visual feedback was compared with a group that received audio feedback. Pitch variation was measured at four stages: in a baseline oral presentation; for the first and second halves of three hours of training; and finally in the production of a new oral presentation. Both groups increased their pitch variation with training, and the effect lasted after the training had ended. The test group showed a significantly higher increase than the control group, indicating that the feedback is effective. These positive results imply that the feedback could be beneficially used in a system for practicing oral presentations.

  2. Effect of Animated Graphic Annotations and Immediate Visual Feedback in Aiding Japanese Pronunciation Learning: A Comparative Study

    Science.gov (United States)

    Hew, Soon-Hin; Ohki, Mitsuru

    2004-01-01

    This study examines the effectiveness of imagery and electronic visual feedback in facilitating students' acquisition of Japanese pronunciation skills. The independent variables, animated graphic annotation (AGA) and immediate visual feedback (IVF) were integrated into a Japanese computer-assisted language learning (JCALL) program focused on the…

  3. The Role of Visual Feedback and Creative Exploration for the Improvement of Timing Accuracy in Performing Musical Ornaments

    NARCIS (Netherlands)

    Timmers, R.; Sadakata, M.; Desain, P.W.M.

    2012-01-01

    in developing a visual feedback system for a creative activity such as music performance, the objective is not just to reinforce one particular manner of performing. Instead, a desirable characteristic might be that the visual feedback enhances flexibility and originality, in addition to

  4. What Motivates Students to Provide Feedback to Teachers about Teaching and Learning? An Expectancy Theory Perspective

    Science.gov (United States)

    Caulfield, Jay

    2007-01-01

    The purpose of this empirical research study was to investigate what motivates students to provide formative anonymous feedback to teachers regarding their perceptions of the teaching and learning experience in order to improve student learning. Expectancy theory, specifically Vroom's Model, was used as the conceptual framework for the study.…

  5. Systematic tracking, visualizing, and interpreting of consumer feedback for drinking water quality.

    Science.gov (United States)

    Dietrich, Andrea M; Phetxumphou, Katherine; Gallagher, Daniel L

    2014-12-01

    Consumer feedback and complaints provide utilities with useful data about consumer perceptions of aesthetic water quality in the distribution system. This research provides a systematic approach to interpret consumer complaint water quality data provided by four water utilities that recorded consumer complaints, but did not routinely process the data. The utilities tended to write down a myriad of descriptors that were too numerous or contained a variety of spellings so that electronic "harvesting" was not possible and much manual labor was required to categorize the complaints into majors areas, such as suggested by the Drinking Water Taste and Odor Wheel or existing check-sheets. When the consumer complaint data were categorized and visualized using spider (or radar) and run-time plots, major taste, odor, and appearance patterns emerged that clarified the issue and could provide guidance to the utility on the nature and extent of the problem. A caveat is that while humans readily identify visual issues with the water, such as color, cloudiness, or rust, describing specific tastes and odors in drinking water is acknowledged to be much more difficult for humans to achieve without training. This was demonstrated with two utility groups and a group of consumers identifying the odors of orange, 2-methylisoborneol, and dimethyl trisulfide. All three groups readily and succinctly identified the familiar orange odor. The two utility groups were much more able to identify the musty odor of 2-methylisoborneol, which was likely familiar to them from their work with raw and finished water. Dimethyl trisulfide, a garlic-onion odor associated with sulfur compounds in drinking water, was the least familiar to all three groups, although the laboratory staff did best. These results indicate that utility personnel should be tolerant of consumers who can assuredly say the water is different, but cannot describe the problem. Also, it indicates that a T&O program at a utility would

  6. Intensive treatment with ultrasound visual feedback for speech sound errors in childhood apraxia

    Directory of Open Access Journals (Sweden)

    Jonathan L Preston

    2016-08-01

    Full Text Available Ultrasound imaging is an adjunct to traditional speech therapy that has shown to be beneficial in the remediation of speech sound errors. Ultrasound biofeedback can be utilized during therapy to provide clients additional knowledge about their tongue shapes when attempting to produce sounds that are in error. The additional feedback may assist children with childhood apraxia of speech in stabilizing motor patterns, thereby facilitating more consistent and accurate productions of sounds and syllables. However, due to its specialized nature, ultrasound visual feedback is a technology that is not widely available to clients. Short-term intensive treatment programs are one option that can be utilized to expand access to ultrasound biofeedback. Schema-based motor learning theory suggests that short-term intensive treatment programs (massed practice may assist children in acquiring more accurate motor patterns. In this case series, three participants ages 10-14 diagnosed with childhood apraxia of speech attended 16 hours of speech therapy over a two-week period to address residual speech sound errors. Two participants had distortions on rhotic sounds, while the third participant demonstrated lateralization of sibilant sounds. During therapy, cues were provided to assist participants in obtaining a tongue shape that facilitated a correct production of the erred sound. Additional practice without ultrasound was also included. Results suggested that all participants showed signs of acquisition of sounds in error. Generalization and retention results were mixed. One participant showed generalization and retention of sounds that were treated; one showed generalization but limited retention; and the third showed no evidence of generalization or retention. Individual characteristics that may facilitate generalization are discussed. Short-term intensive treatment programs using ultrasound biofeedback may result in the acquisition of more accurate motor

  7. Real-Time Knee Adduction Moment Feedback for Gait Retraining Through Visual and Tactile Displays

    KAUST Repository

    Wheeler, Jason W.

    2011-01-01

    The external knee adduction moment (KAM) measured during gait is an indicator of tibiofemoral joint osteoarthritis progression and various strategies have been proposed to lower it. Gait retraining has been shown to be an effective, noninvasive approach for lowering the KAM. We present a new gait retraining approach in which the KAM is fed back to subjects in real-time during ambulation. A study was conducted in which 16 healthy subjects learned to alter gait patterns to lower the KAM through visual or tactile (vibration) feedback. Participants converged on a comfortable gait in just a few minutes by using the feedback to iterate on various kinematic modifications. All subjects adopted altered gait patterns with lower KAM compared with normal ambulation (average reduction of 20.7%). Tactile and visual feedbacks were equally effective for real-time training, although subjects using tactile feedback took longer to converge on an acceptable gait. This study shows that real-time feedback of the KAM can greatly increase the effectiveness and efficiency of subject-specific gait retraining compared with conventional methods. © 2011 American Society of Mechanical Engineers.

  8. Automated numerical simulation of biological pattern formation based on visual feedback simulation framework

    Science.gov (United States)

    Sun, Mingzhu; Xu, Hui; Zeng, Xingjuan; Zhao, Xin

    2017-01-01

    There are various fantastic biological phenomena in biological pattern formation. Mathematical modeling using reaction-diffusion partial differential equation systems is employed to study the mechanism of pattern formation. However, model parameter selection is both difficult and time consuming. In this paper, a visual feedback simulation framework is proposed to calculate the parameters of a mathematical model automatically based on the basic principle of feedback control. In the simulation framework, the simulation results are visualized, and the image features are extracted as the system feedback. Then, the unknown model parameters are obtained by comparing the image features of the simulation image and the target biological pattern. Considering two typical applications, the visual feedback simulation framework is applied to fulfill pattern formation simulations for vascular mesenchymal cells and lung development. In the simulation framework, the spot, stripe, labyrinthine patterns of vascular mesenchymal cells, the normal branching pattern and the branching pattern lacking side branching for lung branching are obtained in a finite number of iterations. The simulation results indicate that it is easy to achieve the simulation targets, especially when the simulation patterns are sensitive to the model parameters. Moreover, this simulation framework can expand to other types of biological pattern formation. PMID:28225811

  9. Teachers' Accounts of Their Perceptions and Practices of Providing Written Feedback to Nursing Students on Their Assignments

    Science.gov (United States)

    Iqbal, Sajid; Gul, Raisa; Lakhani, Arusa; Rizvi, Nusrat Fatima

    2014-01-01

    Written feedback can facilitate students' learning in several ways. However, the teachers' practices of written feedback may be affected by various factors. This study aimed to explore the nurse teachers' accounts of their perceptions and practices of providing written feedback. A descriptive exploratory design was employed in the study. A…

  10. Attainment and retention of force moderation following laparoscopic resection training with visual force feedback.

    Science.gov (United States)

    Hernandez, Rafael; Onar-Thomas, Arzu; Travascio, Francesco; Asfour, Shihab

    2017-11-01

    Laparoscopic training with visual force feedback can lead to immediate improvements in force moderation. However, the long-term retention of this kind of learning and its potential decay are yet unclear. A laparoscopic resection task and force sensing apparatus were designed to assess the benefits of visual force feedback training. Twenty-two male university students with no previous experience in laparoscopy underwent relevant FLS proficiency training. Participants were randomly assigned to either a control or treatment group. Both groups trained on the task for 2 weeks as follows: initial baseline, sixteen training trials, and post-test immediately after. The treatment group had visual force feedback during training, whereas the control group did not. Participants then performed four weekly test trials to assess long-term retention of training. Outcomes recorded were maximum pulling and pushing forces, completion time, and rated task difficulty. Extreme maximum pulling force values were tapered throughout both the training and retention periods. Average maximum pushing forces were significantly lowered towards the end of training and during retention period. No significant decay of applied force learning was found during the 4-week retention period. Completion time and rated task difficulty were higher during training, but results indicate that the difference eventually fades during the retention period. Significant differences in aptitude across participants were found. Visual force feedback training improves on certain aspects of force moderation in a laparoscopic resection task. Results suggest that with enough training there is no significant decay of learning within the first month of the retention period. It is essential to account for differences in aptitude between individuals in this type of longitudinal research. This study shows how an inexpensive force measuring system can be used with an FLS Trainer System after some retrofitting. Surgical

  11. Real-Time Visual Feedback of Airflow in Voice Training: Aerodynamic Properties of Two Flow Ball Devices.

    Science.gov (United States)

    Lã, Filipa M B; Wistbacka, Greta; Andrade, Pedro Amarante; Granqvist, Svante

    2017-05-01

    Flow ball devices have been used as teaching tools to provide visual real-time feedback of airflow during singing. This study aims at exploring static back pressure and ball height as function of flow for two devices, marketed as flow ball and floating ball game. This is a comparative descriptive study. A flow-driven vocal tract simulator was used to investigate the aerodynamic properties of these two devices, testing them for four different ball sizes. The flow range investigated was between 0 and 0.5 L/s. Audio, flow, pressure, and ball height were recorded. The flow pressure profiles for both tested devices were similar to those observed in previous studies on narrow tubes. For lifting the ball, both devices had a flow and a pressure threshold. The tested floating ball game required considerably higher back pressure for a given flow as compared with the flow ball. Both tested devices have similar effects on back pressure as straws of 3.7 and 3.0 mm in diameter for the flow ball and the floating ball game, respectively. One might argue that both devices could be used as tools for practicing semi-occluded vocal tract exercises, with the additional benefit of providing real-time visual feedback of airflow during phonation. The flow threshold, combined with the flow feedback, would increase awareness of flow, rather than of pressure, during exercises using a flow ball device. Published by Elsevier Inc.

  12. A dual visual-local feedback model of the vergence eye movement system.

    Science.gov (United States)

    Erkelens, Casper J

    2011-09-27

    Pure vergence movements are the eye movements that we make when we change our binocular fixation between targets differing in distance but not in direction relative to the head. Pure vergence is slow and controlled by visual feedback. Saccades are the rapid eye movements that we make between targets differing in direction. Saccades are extremely fast and controlled by a local, non-visual feedback loop. Usually, we change our fixation between targets that differ in both distance and direction. Then, vergence eye movements are combined with saccades. A number of models have been proposed to explain the dynamics of saccade-related vergence movements. The models have in common that visual input is ignored for the duration of the responses. This type of control is realistic for saccades but not for vergence. Here, I present computations performed to investigate if a model using dual visual and local feedback can replace the current models. Simulations and stability analysis lead to a model that computes an estimate of target vergence instead of retinal disparity and uses this signal as the main drive. Further analysis shows that the model describes the dynamics of pure vergence responses over the full physiological range, saccade-related vergence movements, and vergence adaptation. The structure of the model leads to new hypotheses about the control of vergence.

  13. Advanced age brings a greater reliance on visual feedback to maintain balance during walking.

    Science.gov (United States)

    Franz, Jason R; Francis, Carrie A; Allen, Matthew S; O'Connor, Shawn M; Thelen, Darryl G

    2015-04-01

    We implemented a virtual reality system to quantify differences in the use of visual feedback to maintain balance during walking between healthy young (n=12, mean age: 24 years) and healthy old (n=11, 71 years) adults. Subjects walked on a treadmill while watching a speed-matched, virtual hallway with and without mediolateral visual perturbations. A motion capture system tracked center of mass (CoM) motion and foot kinematics. Spectral analysis, detrended fluctuation analysis, and local divergence exponents quantified old and young adults' dynamic response to visual perturbations. Old and young adults walked normally with comparable CoM spectral characteristics, lateral step placement temporal persistence, and local divergence exponents. Perturbed visual flow induced significantly larger changes in mediolateral CoM motion in old vs. young adults. Moreover, visual perturbations disrupted the control of lateral step placement and compromised local dynamic stability more significantly in old than young adults. Advanced age induces a greater reliance on visual feedback to maintain balance during waking, an effect that may compensate for degradations in somatosensation. Our findings are relevant to the early diagnosis of sensory-induced balance impairments and also point to the potential use of virtual reality to evaluate sensory rehabilitation and balance training programs for old adults. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Effects of visual feedback-induced variability on motor learning of handrim wheelchair propulsion.

    Directory of Open Access Journals (Sweden)

    Marika T Leving

    Full Text Available It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are thought to be closely related during the learning process.17 Participants received visual feedback-based practice (feedback group and 15 participants received regular practice (natural learning group. Both groups received equal practice dose of 80 min, over 3 weeks, at 0.24 W/kg at a treadmill speed of 1.11 m/s. To compare both groups the pre- and post-test were performed without feedback. The feedback group received real-time visual feedback on seven propulsion variables with instruction to manipulate the presented variable to achieve the highest possible variability (1st 4-min block and optimize it in the prescribed direction (2nd 4-min block. To increase motor exploration the participants were unaware of the exact variable they received feedback on. Energy consumption and the propulsion technique variables with their respective coefficient of variation were calculated to evaluate the amount of intra-individual variability.The feedback group, which practiced with higher intra-individual variability, improved the propulsion technique between pre- and post-test to the same extent as the natural learning group. Mechanical efficiency improved between pre- and post-test in the natural learning group but remained unchanged in the feedback group.These results suggest that feedback-induced variability inhibited the improvement in mechanical efficiency. Moreover, since both groups improved propulsion technique but only the natural learning group improved mechanical efficiency, it can be concluded that the improvement in mechanical efficiency and propulsion technique do not

  15. Guideline implementation in clinical practice: use of statistical process control charts as visual feedback devices.

    Science.gov (United States)

    Al-Hussein, Fahad A

    2009-01-01

    To use statistical control charts in a series of audits to improve the acceptance and consistant use of guidelines, and reduce the variations in prescription processing in primary health care. A series of audits were done at the main satellite of King Saud Housing Family and Community Medicine Center, National Guard Health Affairs, Riyadh, where three general practitioners and six pharmacists provide outpatient care to about 3000 residents. Audits were carried out every fortnight to calculate the proportion of prescriptions that did not conform to the given guidelines of prescribing and dispensing. Simple random samples of thirty were chosen from a sampling frame of all prescriptions given in the two previous weeks. Thirty six audits were carried out from September 2004 to February 2006. P-charts were constructed around a parametric specification of non-conformities not exceeding 25%. Of the 1081 prescriptions, the most frequent non-conformity was failure to write generic names (35.5%), followed by the failure to record patient's weight (16.4%), pharmacist's name (14.3%), duration of therapy (9.1%), and the use of inappropriate abbreviations (6.0%). Initially, 100% of prescriptions did not conform to the guidelines, but within a period of three months, this came down to 40%. A process of audits in the context of statistical process control is necessary for any improvement in the implementation of guidelines in primary care. Statistical process control charts are an effective means of visual feedback to the care providers.

  16. Thoracic ROM measurement system with visual bio-feedback: system design and biofeedback evaluation.

    Science.gov (United States)

    Ando, Takeshi; Kawamura, Kazuya; Fujitani, Junko; Koike, Tomokazu; Fujimoto, Masashi; Fujie, Masakatsu G

    2011-01-01

    Patients with diseases such as chronic obstructive pulmonary disease (COPD) need to improve their thorax mobility. Thoracic ROM is one of the simplest and most useful indexes to evaluate the respiratory function. In this paper, we have proposed the prototype of a simple thoracic ROM measurement system with real-time visual bio-feedback in the chest expansion test. In this system, the thoracic ROM is measured using a wire-type linear encoder whose wire is wrapped around the thorax. In this paper, firstly, the repeatability and reliability of measured thoracic ROM was confirmed as a first report of the developed prototype. Secondly, we analyzed the effect of the bio-feedback system on the respiratory function. The result of the experiment showed that it was easier to maintain a large and stable thoracic ROM during deep breathing by using the real-time visual biofeedback system of the thoracic ROM.

  17. Assisting the visually impaired: obstacle detection and warning system by acoustic feedback.

    Science.gov (United States)

    Rodríguez, Alberto; Yebes, J Javier; Alcantarilla, Pablo F; Bergasa, Luis M; Almazán, Javier; Cela, Andrés

    2012-12-17

    The aim of this article is focused on the design of an obstacle detection system for assisting visually impaired people. A dense disparity map is computed from the images of a stereo camera carried by the user. By using the dense disparity map, potential obstacles can be detected in 3D in indoor and outdoor scenarios. A ground plane estimation algorithm based on RANSAC plus filtering techniques allows the robust detection of the ground in every frame. A polar grid representation is proposed to account for the potential obstacles in the scene. The design is completed with acoustic feedback to assist visually impaired users while approaching obstacles. Beep sounds with different frequencies and repetitions inform the user about the presence of obstacles. Audio bone conducting technology is employed to play these sounds without interrupting the visually impaired user from hearing other important sounds from its local environment. A user study participated by four visually impaired volunteers supports the proposed system.

  18. Assisting the Visually Impaired: Obstacle Detection and Warning System by Acoustic Feedback

    Directory of Open Access Journals (Sweden)

    Andrés Cela

    2012-12-01

    Full Text Available The aim of this article is focused on the design of an obstacle detection system for assisting visually impaired people. A dense disparity map is computed from the images of a stereo camera carried by the user. By using the dense disparity map, potential obstacles can be detected in 3D in indoor and outdoor scenarios. A ground plane estimation algorithm based on RANSAC plus filtering techniques allows the robust detection of the ground in every frame. A polar grid representation is proposed to account for the potential obstacles in the scene. The design is completed with acoustic feedback to assist visually impaired users while approaching obstacles. Beep sounds with different frequencies and repetitions inform the user about the presence of obstacles. Audio bone conducting technology is employed to play these sounds without interrupting the visually impaired user from hearing other important sounds from its local environment. A user study participated by four visually impaired volunteers supports the proposed system.

  19. Effect of providing feedback and prescribing education on prescription writing: An intervention study.

    Science.gov (United States)

    Ajemigbitse, Adetutu A; Omole, Moses Kayode; Erhun, Wilson O

    2016-01-01

    Accurate medication prescribing important to avoid errors and ensure best possible outcomes. This is a report of assessment of the impact of providing feedback and educational intervention on prescribing error types and rates in routine practice. Doctors' prescriptions from selected wards in two tertiary hospitals in central Nigeria were prospectively reviewed for a 6-month period and assessed for errors; grouped into six categories. Intervention was by providing feedback and educational outreach on the specialty/departmental level at one hospital while the other acted as the control. Chi-squared statistics was used to compare prescribing characteristics pre- and post-intervention. At baseline, error rate was higher at the control site. At the intervention site, statistically significant reductions were obtained for errors involving omission of route of administration (P error rate post intervention (P = 0.984). Though House Officers and Registrars wrote most prescriptions, highest reduction in prescribing error rates post intervention was by the registrars (0.93% to 0.29%, P prescriptions that lacked essential details was common. Intervention resulted in modest changes. Routinely providing feedback and continuing prescriber education will likely sustain error reduction.

  20. State-feedback stabilisation for stochastic non-holonomic mobile robots with uncertain visual servoing parameters

    Science.gov (United States)

    Zhang, Dongkai; Wang, Chaoli; Wei, Guoliang; Zhang, Hengjun; Chen, Hua

    2014-07-01

    The stabilising problem of stochastic non-holonomic mobile robots with uncertain parameters based on visual servoing is addressed in this paper. The model of non-holonomic mobile robots based on visual servoing is extended to the stochastic case, where their forward velocity and angular velocity are both subject to some stochastic disturbances. Based on backstepping technique, state-feedback stabilising controllers are designed for stochastic non-holonomic mobile robots. A switching control strategy for the original system is presented. The proposed controllers guarantee that the closed-loop system is asymptotically stabilised at the zero equilibrium point in probability.

  1. Analyzing effects of providing performance feedback at ward rounds on guideline adherence - the importance of feedback usage analysis and statistical control charts.

    Science.gov (United States)

    Abu-Hanna, Ameen; Eslami, Saeid; Schultz, Marcus J; de Jonge, Evert; de Keizer, Nicolette F

    2010-01-01

    Feedback to clinicians on their past performance is often aimed at increasing adherence to guidelines. We investigate how various analytical approaches influence the interpretation of adherence data. The analytical approaches vary in considering the actual or the intended use of the feedback, and whether outcomes are inspected over time. At base line, a computerized decision support system was employed at the ICU bedside to increase adherence to a mechanical ventilation strategy. We intervened by providing feedback about adherence to the guideline at the daily ward rounds. The outcome measure was the percentage of ventilation time (VT) in excess of the guideline's recommendation. Actual usage of the feedback was logged and data analysis was carried out using two approaches: classical statistics, and statistical process control (SPC) that inspect progress of an outcome over time. Prospective, before/after study. The classical analysis stated that the percentage of ventilation time in excess of the guideline's recommendation decreased significantly due to the feedback (5% reduction, p analysis of the outcome was applied, the effect was deemed not significant. When the actual delivery of feedback over time was also included it showed that the experiment does not allow for conclusive results. The concluded effect of providing feedback on adherence to a guideline depends on whether the actual usage pattern of the feedback and the inspection of the outcome over time are considered. Future evaluative studies should report on usage patterns and progression of outcomes over time.

  2. Feature-saliency and feedback-information interactively impact visual category learning

    Directory of Open Access Journals (Sweden)

    Rubi eHammer

    2015-02-01

    Full Text Available Visual category learning (VCL involves detecting which features are most relevant for categorization. This requires attentional learning, which allows effectively redirecting attention to object’s features most relevant for categorization while also filtering out irrelevant features. When features relevant for categorization are not salient VCL relies also on perceptual learning, which enable becoming more sensitive to subtle yet important differences between objects. Little is known about how attentional learning and perceptual learning interact when VCL relies on both processes at the same time. Here we tested this interaction. Participants performed VCL tasks that varied in feature-saliency (low-saliency tasks that required perceptual learning vs. high-saliency tasks, and in feedback-information (tasks with mid-information, moderately ambiguous feedback that increased attentional load vs. tasks with high-information non-ambiguous feedback. Participants were required learning to categorize novel stimuli by detecting the feature-dimension relevant for categorization. We found that mid-information and high-information feedback were similarly effective for VCL in high-saliency tasks. This suggests that an increased attentional load associated with the processing of moderately ambiguous feedback does not compromise VCL when both the task relevant feature and irrelevant features are salient. In low-saliency VCL tasks performance improvement relied on slower perceptual learning, but when the feedback was highly-informative participants were ultimately capable reaching performances matching those observed in high-saliency VCL tasks. However, VCL was much compromised when features were with low-saliency and the feedback was ambiguous. We suggest that this later learning scenario is characterized by a ‘cognitive loop paradox’ where two interdependent learning processes have to take place simultaneously.

  3. A Computerized Tablet with Visual Feedback of Hand Position for Functional Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Mahta eKarimpoor

    2015-03-01

    Full Text Available Neuropsychological tests - behavioral tasks that very commonly involve handwriting and drawing - are widely used in the clinic to detect abnormal brain function. Functional magnetic resonance imaging (fMRI may be useful in increasing the specificity of such tests. However, performing complex pen-and-paper tests during fMRI involves engineering challenges. Previously, we developed an fMRI-compatible, computerized tablet system to address this issue. However, the tablet did not include visual feedback of hand position (VFHP, a human factors component that may be important for fMRI of certain patient populations. A real-time system was thus developed to provide VFHP and integrated with the tablet in an augmented reality display. The effectiveness of the system was initially tested in young healthy adults who performed various handwriting tasks in front of a computer display with and without VFHP. Pilot fMRI of writing tasks were performed by two representative individuals with and without VFHP. Quantitative analysis of the behavioral results indicated improved writing performance with VFHP. The pilot fMRI results suggest that writing with VFHP requires less neural resources compared to the without VFHP condition, to maintain similar behavior. Thus, the tablet system with VFHP is recommended for future fMRI studies involving patients with impaired brain function and where ecologically valid behavior is important.

  4. Virtual reality visual feedback for hand-controlled scanning probe microscopy manipulation of single molecules.

    Science.gov (United States)

    Leinen, Philipp; Green, Matthew F B; Esat, Taner; Wagner, Christian; Tautz, F Stefan; Temirov, Ruslan

    2015-01-01

    Controlled manipulation of single molecules is an important step towards the fabrication of single molecule devices and nanoscale molecular machines. Currently, scanning probe microscopy (SPM) is the only technique that facilitates direct imaging and manipulations of nanometer-sized molecular compounds on surfaces. The technique of hand-controlled manipulation (HCM) introduced recently in Beilstein J. Nanotechnol. 2014, 5, 1926-1932 simplifies the identification of successful manipulation protocols in situations when the interaction pattern of the manipulated molecule with its environment is not fully known. Here we present a further technical development that substantially improves the effectiveness of HCM. By adding Oculus Rift virtual reality goggles to our HCM set-up we provide the experimentalist with 3D visual feedback that displays the currently executed trajectory and the position of the SPM tip during manipulation in real time, while simultaneously plotting the experimentally measured frequency shift (Δf) of the non-contact atomic force microscope (NC-AFM) tuning fork sensor as well as the magnitude of the electric current (I) flowing between the tip and the surface. The advantages of the set-up are demonstrated by applying it to the model problem of the extraction of an individual PTCDA molecule from its hydrogen-bonded monolayer grown on Ag(111) surface.

  5. Virtual reality visual feedback for hand-controlled scanning probe microscopy manipulation of single molecules

    Directory of Open Access Journals (Sweden)

    Philipp Leinen

    2015-11-01

    Full Text Available Controlled manipulation of single molecules is an important step towards the fabrication of single molecule devices and nanoscale molecular machines. Currently, scanning probe microscopy (SPM is the only technique that facilitates direct imaging and manipulations of nanometer-sized molecular compounds on surfaces. The technique of hand-controlled manipulation (HCM introduced recently in Beilstein J. Nanotechnol. 2014, 5, 1926–1932 simplifies the identification of successful manipulation protocols in situations when the interaction pattern of the manipulated molecule with its environment is not fully known. Here we present a further technical development that substantially improves the effectiveness of HCM. By adding Oculus Rift virtual reality goggles to our HCM set-up we provide the experimentalist with 3D visual feedback that displays the currently executed trajectory and the position of the SPM tip during manipulation in real time, while simultaneously plotting the experimentally measured frequency shift (Δf of the non-contact atomic force microscope (NC-AFM tuning fork sensor as well as the magnitude of the electric current (I flowing between the tip and the surface. The advantages of the set-up are demonstrated by applying it to the model problem of the extraction of an individual PTCDA molecule from its hydrogen-bonded monolayer grown on Ag(111 surface.

  6. Training residential supervisors to provide feedback for maintaining staff teaching skills with people who have severe disabilities.

    OpenAIRE

    Parsons, M B; Reid, D H

    1995-01-01

    We evaluated procedures for training supervisors in a residential setting to provide feedback for maintaining direct-service staff members ' teaching skills with people who have severe disabilities. Using classroom-based instruction and on-the-job observation and feedback, 10 supervisors were initially trained to implement teaching programs themselves. The training improved supervisors' teaching skills but was insufficient to improve the quality of feedback they provided to direct-service sta...

  7. Using Press Ganey Provider Feedback to Improve Patient Satisfaction: A Pilot Randomized Controlled Trial.

    Science.gov (United States)

    Newgard, Craig D; Fu, Rongwei; Heilman, James; Tanski, Mary; John Ma, O; Lines, Alan; Keith French, L

    2017-09-01

    The objective was to conduct a pilot randomized controlled trial to assess the feasibility, logistics, and potential effect of monthly provider funnel plot feedback reports from Press Ganey data and semiannual face-to-face coaching sessions to improve patient satisfaction scores. This was a pilot randomized controlled trial of 25 emergency medicine faculty providers in one urban academic emergency department. We enrolled full-time clinical faculty with at least 12 months of baseline Press Ganey data, who anticipated working in the ED for at least 12 additional months. Providers were randomized into intervention or control groups in a 1:1 ratio. The intervention group had an initial 20-minute meeting to introduce the funnel plot feedback tool and standardized feedback based on their baseline Press Ganey scores and then received a monthly e-mail with their individualized funnel plot depicting cumulative Press Ganey scores (compared to their baseline score and the mean score of all providers) for 12 months. The primary outcome was the difference in Press Ganey "doctor-overall" scores between treatment groups at 12 months. We used a weighted analysis of covariance model to analyze the study groups, accounting for variation in the number of surveys by provider and baseline scores. Of 36 eligible faculty, we enrolled 25 providers, 13 of whom were randomized to the intervention group and 12 to the control group. During the study period, there were 815 Press Ganey surveys returned, ranging from four to 71 surveys per provider. For the standardized overall doctor score over 12 months (primary outcome), there was no difference between the intervention and control groups (difference = 1.3 points, 95% confidence interval = -2.4 to 5.9, p = 0.47). Similarly, there was no difference between groups when evaluating the four categories of doctor-specific patient satisfaction scores from the Press Ganey survey (all p > 0.05). In this pilot trial of monthly provider funnel plot

  8. The Effects of Visual Feedback on CPR Skill Retention in Graduate Student Athletic Trainers

    Directory of Open Access Journals (Sweden)

    Michael G. Miller

    2015-09-01

    Full Text Available Context: Studies examining the effectiveness of cardiopulmonary resuscitation (CPR chest compressions have found compression depth and rate to be less than optimal and recoil to full release to be incomplete. Objective: To determine if visual feedback affects the rate and depth of chest compressions and chest recoil values during CPR training of athletic trainers and to determine retention of proficiency over time. Design: Pre-test, post-test. Setting: Medical simulation laboratory. Participants: Eleven females and one male (23.08+.51 years old, from an Athletic Training Graduate Program. All participants were Certified Athletic Trainers (1.12+.46 years of experience and certified in CPR for the Professional Rescuer. Interventions: Participants completed a pre-test, practice sessions, and a post-test on a SimMan® (Laerdal Medical manikin with visual feedback of skills in real time. After the pre-test, participants received feedback by the investigators. Participants completed practice sessions as needed (range=1-4 sessions, until they reached 100% skill proficiency. After achieving proficiency, participants returned 8 weeks later to perform the CPR skills. Main Outcome Measures: The average of all compression outcome measures (rate, depth, recoil was captured every 10 seconds (6x per min. All participants performed 5 cycles of 30 compressions. A two-tailed paired samples t-test (pre to post was used to compare rate of chest compressions, depth of chest compressions, and recoil of the chest. Significance was set a priori at pResults: There was a significant difference between pre and post-test compression depth average, p=.002. The pre-depth average was 41mm + 9.83mm compared to the post-depth average of 52.26mm + 5mm. There were no significant differences between pre and post-test chest compression rates and recoil. Conclusions: The use of a simulated manikin with visual feedback facilitated participants to reach the recommended compression

  9. Anatomy of hierarchy: feedforward and feedback pathways in macaque visual cortex.

    Science.gov (United States)

    Markov, Nikola T; Vezoli, Julien; Chameau, Pascal; Falchier, Arnaud; Quilodran, René; Huissoud, Cyril; Lamy, Camille; Misery, Pierre; Giroud, Pascale; Ullman, Shimon; Barone, Pascal; Dehay, Colette; Knoblauch, Kenneth; Kennedy, Henry

    2014-01-01

    The laminar location of the cell bodies and terminals of interareal connections determines the hierarchical structural organization of the cortex and has been intensively studied. However, we still have only a rudimentary understanding of the connectional principles of feedforward (FF) and feedback (FB) pathways. Quantitative analysis of retrograde tracers was used to extend the notion that the laminar distribution of neurons interconnecting visual areas provides an index of hierarchical distance (percentage of supragranular labeled neurons [SLN]). We show that: 1) SLN values constrain models of cortical hierarchy, revealing previously unsuspected areal relations; 2) SLN reflects the operation of a combinatorial distance rule acting differentially on sets of connections between areas; 3) Supragranular layers contain highly segregated bottom-up and top-down streams, both of which exhibit point-to-point connectivity. This contrasts with the infragranular layers, which contain diffuse bottom-up and top-down streams; 4) Cell filling of the parent neurons of FF and FB pathways provides further evidence of compartmentalization; 5) FF pathways have higher weights, cross fewer hierarchical levels, and are less numerous than FB pathways. Taken together, the present results suggest that cortical hierarchies are built from supra- and infragranular counterstreams. This compartmentalized dual counterstream organization allows point-to-point connectivity in both bottom-up and top-down directions. Copyright © 2013 Wiley Periodicals, Inc. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  10. Inferring online and offline processing of visual feedback in target-directed movements from kinematic data.

    Science.gov (United States)

    Khan, Michael A; Franks, Ian M; Elliott, Digby; Lawrence, Gavin P; Chua, Romeo; Bernier, Pierre-Michel; Hansen, Steve; Weeks, Daniel J

    2006-01-01

    Vision plays an important role in the planning and execution of target-directed aiming movements. In this review, we highlight the limitations that exist in detecting visual regulation of limb trajectories from traditional kinematic analyses such as the identification of discontinuities in velocity and acceleration. Alternative kinematic analyses that involve examining variability in limb trajectories to infer visual control processes are evaluated. The basic assumption underlying these methods is that noise exists in the neuromotor system that subsequently leads to variability in motor output. This leads to systematic relations in limb trajectory variability at different stages of the movement that are altered when trajectories are modified during movement execution. Hence, by examining the variability in limb trajectories and correlations of kinematic variables throughout movement for vision and no vision conditions, the contribution of visual feedback in the planning and control of movement can be determined.

  11. Effect of Training Japanese L1 Speakers in the Production of American English /r/ Using Spectrographic Visual Feedback

    Science.gov (United States)

    Patten, Iomi; Edmonds, Lisa A.

    2015-01-01

    The present study examines the effects of training native Japanese speakers in the production of American /r/ using spectrographic visual feedback. Within a modified single-subject design, two native Japanese participants produced single words containing /r/ in a variety of positions while viewing live spectrographic feedback with the aim of…

  12. The Rightful Demise of the Sh*t Sandwich: Providing Effective Feedback.

    Science.gov (United States)

    James, Ian Andrew

    2015-11-01

    As a trainee cognitive therapist in the early 1990s, I was taught the Sh*t Sandwich by my supervisor. I continued to use this technique for many years without seeing the need to extend my repertoire of feedback strategies. This article describes a number of other feedback techniques, raising awareness of the processes underpinning feedback, and facilitating reflection on feedback methods. This review examines feedback and the methods of feedback used to improve clinical competence. Evidence informs us that the use of good feedback has a significant effect on learners' outcomes (Milne, 2009). However, despite recognition of its importance, many supervisors fail to give adequate feedback and utilize methods that are sub-optimal. One such problematic method is the notorious "Sh*t Sandwich" (SS), which attempts to hide criticism within a cushion of two positive statements. This paper looks at various models of giving negative and positive feedback, suggesting that our repertoire of feedback methods may require expanding. The review suggests that feedback is a complex process and methods that place an emphasis on the learner as an active participant in the learning process (i.e. interactive approaches) should be encouraged. The paper suggests that negative feedback should generally be avoided in favour of constructive support, accompanied by specific, descriptive, balanced feedback, with new learning being consolidated by role play. Generally, feedback should be given about the task rather than the person, but when it is personalized it should relate to effort rather than ability.

  13. Effect of augmented visual feedback from a virtual reality simulation system on manual dexterity training.

    Science.gov (United States)

    Wierinck, E; Puttemans, V; Swinnen, S; van Steenberghe, D

    2005-02-01

    Little research has been published about the impact of simulation technology on the learning process of novel motor skills. Especially the role of augmented feedback (FB) on the quality of performance and the transfer of the acquired behaviour to a no-augmented FB condition require further investigation. Therefore, novice dental students were randomly assigned to one of three groups and given the task of drilling a geometrical class 1 cavity. The FB group trained under augmented visual FB conditions, provided by the virtual reality (VR) system (DentSim). The no-FB group practised under normal vision conditions, in the absence of augmented FB. A control group performed the test sessions without participating in any training programme. All preparations were evaluated by the VR grading system according to four traditional (outline shape, floor depth, floor smoothness and wall inclination), and two critical, criteria (pulp exposure and damage to adjacent teeth). Performance analyses revealed an overall trend towards significant improvement with training for the experimental groups. The FB group obtained the highest scores. It scored better for floor depth (P < 0.001), whilst the no-FB group was best for floor smoothness (P < 0.005). However, at the retention tests, the FB group demonstrated inferior performance in comparison with the no-FB group. The transfer test on a traditional unit revealed no significant differences between the training groups. Consequently, drilling experience on a VR system under the condition of frequently provided FB and lack of any tutorial input was considered to be not beneficial to learning. The present data are discussed in view of the guidance hypothesis of FB, which refers to the apprentice's dependence on FB.

  14. Real-time fMRI brain-computer interface: Development of a "motivational feedback" subsystem for the regulation of visual cue reactivity

    Directory of Open Access Journals (Sweden)

    Moses O. Sokunbi

    2014-11-01

    Full Text Available Here we present a novel neurofeedback subsystem for the presentation of motivationally relevant visual feedback during the self-regulation of functional brain activation. Our motivational neurofeedback approach uses functional magnetic resonance imaging (fMRI signals elicited by visual cues (pictures and related to motivational processes such as craving or hunger. The visual feedback subsystem provides simultaneous feedback through these images as their size corresponds to the magnitude of fMRI signal change from a target brain area. During self-regulation of cue-evoked brain responses, decreases and increases in picture size thus provide real motivational consequences in terms of cue approach versus cue avoidance, which increases face validity of the approach in applied settings. Further, the outlined approach comprises of neurofeedback (regulation and mirror runs that allow to control for non-specific and task-unrelated effects, such as habituation or neural adaptation. The approach was implemented in the Python programming language. Pilot data from 10 volunteers showed that participants were able to successfully down-regulate individually defined target areas, demonstrating feasibility of the approach. The newly developed visual feedback subsystem can be integrated into protocols for imaging-based brain-computer interfaces (BCI and may facilitate neurofeedback research and applications into healthy and dysfunctional motivational processes, such food craving or addiction.

  15. Joint coordination in young and older adults during quiet stance: effect of visual feedback of the center of pressure.

    Science.gov (United States)

    Freitas, Sandra Maria Sbeghen Ferreira; Duarte, Marcos

    2012-01-01

    How aging affects body sway and joint coordination during quiet standing was investigated under two visual feedback conditions provided on a monitor screen: fixed and moving cursor representing the center of pressure (COP) position measured by a platform. The across-time joint motion variance of ankle, knee, hip, mid-trunk, and cervical spine leading to COP displacement was analyzed using the uncontrolled manifold approach. The body sway was assessed by the COP displacement. Young and older adults showed greater ankle joint contribution to COP displacement than the other joints. However, older adults showed larger variability of knee and mid-trunk joint motions than young adults. During the moving condition, the ankle joint contribution decreased and hip joint contribution increased for both groups, but the COP displacement increased only for the older adults. We conclude that joint coordination and body sway during quiet standing can be modified by providing COP visual feedback and that joint coordination is affected by aging. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. A method of providing engaging formative feedback to large cohort first-year physiology and anatomy students.

    Science.gov (United States)

    Weston-Green, Katrina; Wallace, Margaret

    2016-09-01

    A growing body of evidence demonstrates a critical role for effective, meaningful feedback to enhance student learning. Effective feedback can become part of the learning cycle that is not only a learning opportunity for the student but can also be used to inform the teacher and ongoing curriculum development. Feedback is considered particularly important during the first year of university and can even be viewed as a retention strategy that can help attenuate student performance anxieties and solidify perceptions of academic support. Unfortunately, the provision of individualized, timely feedback can be particularly challenging in first-year courses as they tend to be large and diverse cohort classes that pose challenges of time and logistics. Various forms of generic feedback can provide rapid and cost-effect feedback to large cohorts but may be of limited benefit to students other than signaling weaknesses in knowledge. The present study describes a method that was used to provide formative task-related feedback to a large cohort of first-year physiology and anatomy students. Based on student evaluations presented in this study, this method provided feedback in a manner that engaged students, uncovered underlying misconceptions, facilitated peer discussion, and provided opportunity for new instruction while allowing the lecturer to recognize common gaps in knowledge and inform ongoing curriculum development. Copyright © 2016 The American Physiological Society.

  17. The Effectiveness of Instructor Personalized and Formative Feedback Provided by Instructor in an Online Setting: Some Unresolved Issues

    Science.gov (United States)

    Planar, Dolors; Moya, Soledad

    2016-01-01

    Formative feedback has great potential for teaching and learning in online undergraduate programmes. There is a large number of courses where the main source of feedback is provided by the instructor. This is particularly seen in subjects where assessments are designed based on specific activities which are the same for all students, and where the…

  18. Alpha-beta and gamma rhythms subserve feedback and feedforward influences among human visual cortical areas

    Science.gov (United States)

    Michalareas, Georgios; Vezoli, Julien; van Pelt, Stan; Schoffelen, Jan-Mathijs; Kennedy, Henry; Fries, Pascal

    2016-01-01

    Primate visual cortex is hierarchically organized. Bottom-up and top-down influences are exerted through distinct frequency channels, as was recently revealed in macaques by correlating inter-areal influences with laminar anatomical projection patterns. Because this anatomical data cannot be obtained in human subjects, we selected seven homologous macaque and human visual areas, and correlated the macaque laminar projection patterns to human inter-areal directed influences as measured with magnetoencephalography. We show that influences along feedforward projections predominate in the gamma band, whereas influences along feedback projections predominate in the alpha-beta band. Rhythmic inter-areal influences constrain a functional hierarchy of the seven homologous human visual areas that is in close agreement with the respective macaque anatomical hierarchy. Rhythmic influences allow an extension of the hierarchy to 26 human visual areas including uniquely human brain areas. Hierarchical levels of ventral and dorsal stream visual areas are differentially affected by inter-areal influences in the alpha-beta band. PMID:26777277

  19. Effects of loss of visual feedback on performance of two swimming strokes.

    Science.gov (United States)

    Cicciarella, C F

    1982-12-01

    20 subjects, aged 11 to 21 yr., skilled in competitive swimming in both the crawl and the breaststroke, performed a total of 8 timed swimming trials of 25 yd. in both strokes both with and without blindfolds to test the hypothesis that the loss in performance which would occur with loss of visual feedback is related to the complexity of the motor skill being performed. After correction for differences in the speed of each stroke, the loss in speed (performance decrement) in the more complex stroke (crawl) was significantly greater than the decrement in the less complex (breast) stroke.

  20. Spherical model provides visual aid for cubic crystal study

    Science.gov (United States)

    Bacigalupi, R. J.; Spakowski, A. E.

    1965-01-01

    Transparent sphere of polymethylmethacrylate with major zones and poles of cubic crystals is used to make crystallographic visualizations and to interpret Laue X ray diffraction of single cubic crystals.

  1. Control Framework for Dexterous Manipulation Using Dynamic Visual Servoing and Tactile Sensors’ Feedback

    Directory of Open Access Journals (Sweden)

    Carlos A. Jara

    2014-01-01

    Full Text Available Tactile sensors play an important role in robotics manipulation to perform dexterous and complex tasks. This paper presents a novel control framework to perform dexterous manipulation with multi-fingered robotic hands using feedback data from tactile and visual sensors. This control framework permits the definition of new visual controllers which allow the path tracking of the object motion taking into account both the dynamics model of the robot hand and the grasping force of the fingertips under a hybrid control scheme. In addition, the proposed general method employs optimal control to obtain the desired behaviour in the joint space of the fingers based on an indicated cost function which determines how the control effort is distributed over the joints of the robotic hand. Finally, authors show experimental verifications on a real robotic manipulation system for some of the controllers derived from the control framework.

  2. Effect of visual feedback information on isometric contraction of forearm flexor muscles in men and women after ischemic stroke.

    Science.gov (United States)

    Darbutas, Tomas; Juodžbalienė, Vilma; Skurvydas, Albertas; Krutulytė, Gražina; Rimdeikienė, Inesa; Brazaitis, Marius

    2012-01-01

    The aim of this study was to determine the effect of visual feedback information (VFI) on the isometric contraction of the forearm flexor muscles in men and women after an ischemic stroke when doing a physical load at 20% of strength. The study included healthy subjects (n=20) and subjects after ischemic stroke (n=20). The study was conducted in Lithuanian Sports University. The measurements of maximum voluntary strength (MVS) and accurate isometric contraction were performed using an isokinetic dynamometer Biodex System Pro 3. The absolute errors of isometric contraction of the right arm muscles at 20% of MVS were similar in all the groups during the attempt with visual feedback information. The smallest absolute errors of the healthy subjects were 1.42±0.35 Nm when the task was performed with visual feedback and the greatest absolute errors were 4.69±0.95 Nm (P<0.01) while performing the task without visual feedback. Meanwhile, the smallest and greatest absolute errors of the subjects after ischemic stroke were 1.32±0.45 Nm and 5.05±0.63 Nm, respectively, while performing the task without visual feedback (P<0.01). Maximum voluntary strength was greater in all the groups of men. The absolute errors of isometric contractions of the right and left arm muscles tended to increase in both the men and the women when there was no visual feedback information. The women and the men after an ischemic stroke produced greater absolute errors when performing the task with the right and left arm without visual feedback information than the healthy subjects.

  3. A lightweight augmented virtuality system for providing a faithful and spatially manipulable visual hand representation.

    Science.gov (United States)

    Pusch, Andreas; Martin, Olivier; Coquillart, Sabine

    2011-01-01

    This paper introduces the technical foundations of a system designed to embed a lightweight, faithful and spatially manipulable representation of the user's hand into an otherwise virtual world - Augmented Virtuality (AV). A highly intuitive control during pointing-like near space interaction can be provided to the user, as well as a very flexible means to experimenters, in a variety of non-medical and medical contexts. Our approach essentially relies on stereoscopic video see-through Augmented Reality (AR) technology and a generic, extendible framework for managing 3-D visual hand displacements. Research from human-computer interaction, perception and motor control has contributed to the elaboration of our proposal which combines a) acting in co-location, b) avoiding occlusion violations by assuring a correct scene depth ordering and c) providing a convincing visual feedback of the user's hand. We further present two cases in which this system has already successfully been used and then outline some other applications that we think are promising, for instance, in the fields of neuromotor rehabilitation and experimental neuroscience.

  4. Real-time vision, tactile cues, and visual form agnosia in pantomimed grasping: removing haptic feedback induces a switch from natural to pantomime-like grasps

    Directory of Open Access Journals (Sweden)

    Robert Leslie Whitwell

    2015-05-01

    Full Text Available Investigators study the kinematics of grasping movements (prehension under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. When patient DF, who suffers from visual form agnosia, performs natural grasps, her in-flight hand aperture is scaled to the widths of targets ('grip scaling' that she cannot discriminate amongst. In contrast, when DF's pantomime grasps are based on a memory of a previewed object, her grip scaling is very poor. Her failure on this task has been interpreted as additional support for the dissociation between the use of object vision for action and object vision for perception. Curiously, however, when DF directs her pantomimed grasps towards a displaced imagined copy of a visible object where her fingers make contact with the surface of the table, her grip scaling does not appear to be particularly poor. In the first of two experiments, we revisit this previous work and show that her grip scaling in this real-time pantomime grasping task does not differ from controls, suggesting that terminal tactile feedback from a proxy of the target can maintain DF's grip scaling. In a second experiment with healthy participants, we tested a recent variant of a grasping task in which no tactile feedback is available (i.e. no haptic feedback by comparing the kinematics of target-directed grasps with and without haptic feedback to those of real-time pantomime grasps without haptic feedback. Compared to natural grasps, removing haptic feedback increased RT, slowed the velocity of the reach, reduced grip aperture, sharpened the slopes relating grip aperture to target width, and reduced the final grip aperture. All of these effects were also observed in the pantomime grasping task. Taken together, these results provide compelling support for the view that removing haptic feedback induces a switch from real-time visual control to one that depends more on visual perception and cognitive supervision.

  5. Laser 3-D measuring system and real-time visual feedback for teaching and correcting breathing

    Science.gov (United States)

    Povšič, Klemen; Fležar, Matjaž; Možina, Janez; Jezeršek, Matija

    2012-03-01

    We present a novel method for real-time 3-D body-shape measurement during breathing based on the laser multiple-line triangulation principle. The laser projector illuminates the measured surface with a pattern of 33 equally inclined light planes. Simultaneously, the camera records the distorted light pattern from a different viewpoint. The acquired images are transferred to a personal computer, where the 3-D surface reconstruction, shape analysis, and display are performed in real time. The measured surface displacements are displayed with a color palette, which enables visual feedback to the patient while breathing is being taught. The measuring range is approximately 400×600×500 mm in width, height, and depth, respectively, and the accuracy of the calibrated apparatus is +/-0.7 mm. The system was evaluated by means of its capability to distinguish between different breathing patterns. The accuracy of the measured volumes of chest-wall deformation during breathing was verified using standard methods of volume measurements. The results show that the presented 3-D measuring system with visual feedback has great potential as a diagnostic and training assistance tool when monitoring and evaluating the breathing pattern, because it offers a simple and effective method of graphical communication with the patient.

  6. Eye-Hand Coordination during Visuomotor Adaptation with Different Rotation Angles: Effects of Terminal Visual Feedback.

    Directory of Open Access Journals (Sweden)

    Miya K Rand

    Full Text Available This study examined adaptive changes of eye-hand coordination during a visuomotor rotation task under the use of terminal visual feedback. Young adults made reaching movements to targets on a digitizer while looking at targets on a monitor where the rotated feedback (a cursor of hand movements appeared after each movement. Three rotation angles (30°, 75° and 150° were examined in three groups in order to vary the task difficulty. The results showed that the 30° group gradually reduced direction errors of reaching with practice and adapted well to the visuomotor rotation. The 75° group made large direction errors of reaching, and the 150° group applied a 180° reversal shift from early practice. The 75°and 150° groups, however, overcompensated the respective rotations at the end of practice. Despite these group differences in adaptive changes of reaching, all groups gradually adapted gaze directions prior to reaching from the target area to the areas related to the final positions of reaching during the course of practice. The adaptive changes of both hand and eye movements in all groups mainly reflected adjustments of movement directions based on explicit knowledge of the applied rotation acquired through practice. Only the 30° group showed small implicit adaptation in both effectors. The results suggest that by adapting gaze directions from the target to the final position of reaching based on explicit knowledge of the visuomotor rotation, the oculomotor system supports the limb-motor system to make precise preplanned adjustments of reaching directions during learning of visuomotor rotation under terminal visual feedback.

  7. Effects of Visual Force Feedback on Robot-Assisted Surgical Task Performance

    Science.gov (United States)

    Reiley, Carol E.; Akinbiyi, Takintope; Burschka, Darius; Chang, David C.; Okamura, Allison M.; Yuh, David D.

    2009-01-01

    Background Direct haptic (force or tactile) feedback is negligible in current surgical robotic systems. The relevance of haptic feedback in robot-assisted performances of surgical tasks is controversial. We studied the effects of visual force feedback (VFF), a haptic feedback surrogate, on tying surgical knots with fine sutures similar to those used in cardiovascular surgery. Methods Using a modified da Vinci robotic system (Intuitive Surgical, Inc.) equipped with force-sensing instrument tips and real-time VFF overlays in the console image, ten surgeons each tied 10 knots with and 10 knots without VFF. Four surgeons had significant prior da Vinci experience while the remaining six surgeons did not. Performance parameters, including suture breakage and secure knots, peak and standard deviation of applied forces, and completion times using 5-0 silk sutures were recorded. Chi-square and Student’s t-test analyses determined differences between groups. Results Among surgeon subjects with robotic experience, no differences in measured performance parameters were found between robot-assisted knot ties executed with and without VFF. Among surgeons without robotic experience, however, VFF was associated with lower suture breakage rates, peak applied forces, and standard deviations of applied forces. VFF did not impart differences in knot completion times or loose knots for either surgeon group. Conclusions VFF resulted in reduced suture breakage, lower forces, and decreased force inconsistencies among novice robotic surgeons, although elapsed time and knot quality were unaffected. In contrast, VFF did not affect these metrics among experienced da Vinci surgeons. These results suggest that VFF primarily benefits novice robot-assisted surgeons, with diminishing benefits among experienced surgeons. PMID:18179942

  8. Providing rapid feedback to residents on their teaching skills: an educational strategy for contemporary trainees.

    Science.gov (United States)

    Katz-Sidlow, Rachel J; Baer, Tamar G; Gershel, Jeffrey C

    2016-03-20

    The objective of this study was to assess the attitudes of contemporary residents toward receiving rapid feedback on their teaching skills from their medical student learners. Participants consisted of 20 residents in their second post-graduate training year. These residents facilitated 44 teaching sessions with medical students within our Resident-as-Teacher program. Structured, written feedback from students was returned to the resident within 3 days following each session. Residents completed a short survey about the utility of the feedback, whether they would make a change to future teaching sessions based on the feedback, and what specifically they might change. The survey utilized a 4-point scale ("Not helpful/likely=1" to "Very helpful/likely=4"), and allowed for one free-text response. Free-text responses were hand-coded and underwent qualitative analysis to identify themes. There were 182 student feedback encounters resulting from 44 teaching sessions. The survey response rate was 73% (32/44). Ninety-four percent of residents rated the rapid feedback as "very helpful," and 91% would "very likely" make a change to subsequent sessions based on student feedback. Residents' proposed changes included modifications to session content and/or their personal teaching style. Residents found that rapid feedback received from medical student learners was highly valuable to them in their roles as teachers. A rapid feedback strategy may facilitate an optimal educational environment for contemporary trainees.

  9. Virtual reality in neurosurgical education: part-task ventriculostomy simulation with dynamic visual and haptic feedback.

    Science.gov (United States)

    Lemole, G Michael; Banerjee, P Pat; Luciano, Cristian; Neckrysh, Sergey; Charbel, Fady T

    2007-07-01

    Mastery of the neurosurgical skill set involves many hours of supervised intraoperative training. Convergence of political, economic, and social forces has limited neurosurgical resident operative exposure. There is need to develop realistic neurosurgical simulations that reproduce the operative experience, unrestricted by time and patient safety constraints. Computer-based, virtual reality platforms offer just such a possibility. The combination of virtual reality with dynamic, three-dimensional stereoscopic visualization, and haptic feedback technologies makes realistic procedural simulation possible. Most neurosurgical procedures can be conceptualized and segmented into critical task components, which can be simulated independently or in conjunction with other modules to recreate the experience of a complex neurosurgical procedure. We use the ImmersiveTouch (ImmersiveTouch, Inc., Chicago, IL) virtual reality platform, developed at the University of Illinois at Chicago, to simulate the task of ventriculostomy catheter placement as a proof-of-concept. Computed tomographic data are used to create a virtual anatomic volume. Haptic feedback offers simulated resistance and relaxation with passage of a virtual three-dimensional ventriculostomy catheter through the brain parenchyma into the ventricle. A dynamic three-dimensional graphical interface renders changing visual perspective as the user's head moves. The simulation platform was found to have realistic visual, tactile, and handling characteristics, as assessed by neurosurgical faculty, residents, and medical students. We have developed a realistic, haptics-based virtual reality simulator for neurosurgical education. Our first module recreates a critical component of the ventriculostomy placement task. This approach to task simulation can be assembled in a modular manner to reproduce entire neurosurgical procedures.

  10. Using Track Changes and Word Processor to Provide Corrective Feedback to Learners in Writing

    Science.gov (United States)

    AbuSeileek, A. F.

    2013-01-01

    This study investigated the effect of computer-mediated corrective feedback types in an English as a foreign language (EFL) intact class over time. The participants were 64 English majors who were assigned randomly into three treatment conditions that gave and received computer-mediated corrective feedback while writing (track changes, word…

  11. Effectiveness of a training program in supervisors' ability to provide feedback on residents' communication skills

    NARCIS (Netherlands)

    Junod Perron, N.; Nendaz, M.; Louis-Simonet, M.; Sommer, J.; Gut, A.; Baroffio, A.; Dolmans, D.; Vleuten, C.P.M. van der

    2013-01-01

    Teaching communication skills (CS) to residents during clinical practice remains problematic. Direct observation followed by feedback is a powerful way to teach CS in clinical practice. However, little is known about the effect of training on feedback skills in this field. Controlled studies are

  12. 'Robot' Hand Illusion under Delayed Visual Feedback: Relationship between the Senses of Ownership and Agency.

    Directory of Open Access Journals (Sweden)

    Mohamad Arif Fahmi Ismail

    Full Text Available The rubber hand illusion (RHI is an illusion of the self-ownership of a rubber hand that is touched synchronously with one's own hand. While the RHI relates to visual and tactile integration, we can also consider a similar illusion with visual and motor integration on a fake hand. We call this a "robot hand illusion" (RoHI, which relates to both the senses of ownership and agency. Here we investigate the effect of delayed visual feedback on the RoHI. Participants viewed a virtual computer graphic hand controlled by their hand movement recorded using a data glove device. We inserted delays of various lengths between the participant's hand and the virtual hand movements (90-590 ms, and the RoHI effects for each delay condition were systematically tested using a questionnaire. The results showed that the participants felt significantly greater RoHI effects with temporal discrepancies of less than 190 ms compared with longer temporal discrepancies, both in the senses of ownership and agency. Additionally, participants felt significant, but weaker, RoHI effects with temporal discrepancies of 290-490 ms in the sense of agency, but not in the sense of ownership. The participants did not feel a RoHI with temporal discrepancies of 590 ms in either the senses of agency or ownership. Our results suggest that a time window of less than 200 ms is critical for multi-sensory integration processes constituting self-body image.

  13. Explicit knowledge about the availability of visual feedback affects grasping with the left but not the right hand.

    Science.gov (United States)

    Tang, Rixin; Whitwell, Robert L; Goodale, Melvyn A

    2014-01-01

    Previous research (Whitwell et al. in Exp Brain Res 188:603-611, 2008; Whitwell and Goodale in Exp Brain Res 194:619-629, 2009) has shown that trial history, but not anticipatory knowledge about the presence or absence of visual feedback on an upcoming trial, plays a vital role in determining how that feedback is exploited when grasping with the right hand. Nothing is known about how the non-dominant left hand behaves under the same feedback regimens. In present study, therefore, we compared peak grip aperture (PGA) for left- and right-hand grasps executed with and without visual feedback (i.e., closed- vs. open-loop conditions) in right-handed individuals under three different trial schedules: the feedback conditions were blocked separately, they were randomly interleaved, or they were alternated. When feedback conditions were blocked, the PGA was much larger for open-loop trials as compared to closed-loop trials, although this difference was more pronounced for right-hand grasps than left-hand grasps. Like Whitwell et al., we found that mixing open- and closed-loop trials together, compared to blocking them separately, homogenized the PGA for open- and closed-loop grasping in the right hand (i.e., the PGAs became smaller on open-loop trials and larger on closed-loop trials). In addition, the PGAs for right-hand grasps were entirely determined by trial history and not by knowledge of whether or not visual feedback would be available on an upcoming trial. In contrast to grasps made with the right hand, grasps made by the left hand were affected both by trial history and by anticipatory knowledge of the upcoming visual feedback condition. But these effects were observed only on closed-loop trials, i.e., the PGAs of grasps made with the left hand on closed-loop trials were smaller when participants could anticipate the availability of feedback on an upcoming trial (alternating trials) than when they could not (randomized trials). In contrast, grasps made with the

  14. Enhanced jump performance when providing augmented feedback compared to an external or internal focus of attention.

    Science.gov (United States)

    Keller, Martin; Lauber, Benedikt; Gottschalk, Marius; Taube, Wolfgang

    2015-01-01

    Factors such as an external focus of attention (EF) and augmented feedback (AF) have been shown to improve performance. However, the efficacy of providing AF to enhance motor performance has never been compared with the effects of an EF or an internal focus of attention (IF). Therefore, the aim of the present study was to identify which of the three conditions (AF, EF or IF) leads to the highest performance in a countermovement jump (CMJ). Nineteen volunteers performed 12 series of 8 maximum CMJs. Changes in jump height between conditions and within the series were analysed. Jump heights differed between conditions (P jump heights at the end of the series in AF (+1.60%) and lower jump heights at the end of the series in EF (-1.79%) and IF (-1.68%) were observed. Muscle activity did not differ between conditions. The differences between conditions and within the series provide evidence that AF leads to higher performance and better progression within one series than EF and IF. Consequently, AF seems to outperform EF and IF when maximising jump height.

  15. Anticipation- and error-related EEG signals during realistic human-machine interaction: a study on visual and tactile feedback.

    Science.gov (United States)

    Chavarriaga, Ricardo; Perrin, Xavier; Siegwart, Roland; Millán, José del R

    2012-01-01

    The exploitation of EEG signatures of cognitive processes can provide valuable information to improve interaction with brain actuated devices. In this work we study these correlates in a realistic situation simulated in a virtual reality environment. We focus on cortical potentials linked to the anticipation of future events (i.e. the contingent negative variation, CNV) and error-related potentials elicited by both visual and tactile feedback. Experiments with 6 subjects show brain activity consistent with previous studies using simpler stimuli, both at the level of ERPs and single trial classification. Moreover, we observe comparable signals irrespective of whether the subject was required to perform motor actions. Altogether, these results support the possibility of using these signals for practical brain machine interaction.

  16. Effect of concurrent visual feedback on acquisition of a weightlifting skill.

    Science.gov (United States)

    Sewall, L P; Reeve, T G; Day, R A

    1988-12-01

    Practice in front of a mirror is a common procedure for activities such as dance, gymnastics, and other sports. The purpose of this study was to examine the effect that performing with concurrent visual feedback from a mirror had on the acquisition of the power clean movement. 18 college-age males who had no prior experience with the power clean movement served as subjects who were assigned to one of two groups. One group had use of a mirror during the practice trials and the other practiced without the mirror. All subjects viewed an instructional videotape and had practice trials. All subjects were evaluated for proper technique on a pretest, a posttest without the mirror, and a posttest with the mirror. Analysis showed a significant difference between pre- and posttest performances for both groups and a significant difference between groups on the posttest performances with the mirror. Evidently the videotaped instruction was sufficient to allow both groups to improve in performance of the power clean. Differences in posttest performances with the mirror reflected the type of feedback (with or without the mirror) available during training.

  17. Climate Feedback: Bringing the Scientific Community to Provide Direct Feedback on the Credibility of Climate Media Coverage

    Science.gov (United States)

    Vincent, E. M.; Matlock, T.; Westerling, A. L.

    2015-12-01

    While most scientists recognize climate change as a major societal and environmental issue, social and political will to tackle the problem is still lacking. One of the biggest obstacles is inaccurate reporting or even outright misinformation in climate change coverage that result in the confusion of the general public on the issue.In today's era of instant access to information, what we read online usually falls outside our field of expertise and it is a real challenge to evaluate what is credible. The emerging technology of web annotation could be a game changer as it allows knowledgeable individuals to attach notes to any piece of text of a webpage and to share them with readers who will be able to see the annotations in-context -like comments on a pdf.Here we present the Climate Feedback initiative that is bringing together a community of climate scientists who collectively evaluate the scientific accuracy of influential climate change media coverage. Scientists annotate articles sentence by sentence and assess whether they are consistent with scientific knowledge allowing readers to see where and why the coverage is -or is not- based on science. Scientists also summarize the essence of their critical commentary in the form of a simple article-level overall credibility rating that quickly informs readers about the credibility of the entire piece.Web-annotation allows readers to 'hear' directly from the experts and to sense the consensus in a personal way as one can literaly see how many scientists agree with a given statement. It also allows a broad population of scientists to interact with the media, notably early career scientists.In this talk, we will present results on the impacts annotations have on readers -regarding their evaluation of the trustworthiness of the information they read- and on journalists -regarding their reception of scientists comments.Several dozen scientists have contributed to this effort to date and the system offers potential to

  18. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans.

    Directory of Open Access Journals (Sweden)

    Laura L Wilkinson

    Full Text Available Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300 ml or 500 ml x 2 (amount eaten; 300 ml or 500 ml between-subjects design was employed (10 participants in each condition. In two 'congruent' conditions, the same amount was seen at the outset and then subsequently consumed (300 ml or 500 ml. To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional 'incongruent' conditions, in which 300 ml was seen but 500 ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300 ml or 500 ml. By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300 ml but actually consumed 500 ml ate at a faster rate than participants who saw 500 ml but actually consumed 300 ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation.

  19. EFFECT OF MIRROR VISUAL FEEDBACK ON HAND FUNCTIONS IN CHILDREN WITH HEMIPARESIS

    Directory of Open Access Journals (Sweden)

    Mohammed Ismael Elsepaee

    2016-04-01

    Full Text Available Background: Hemiparetic and hemiplegic cerebral palsy(CP constitute at least a third of all people with CP. Children with hemiparesis are suffering from weak hand muscles and retarded hand use.Mirror therapy is a relatively new approach in rehabilitation used in different neurological disorders. In mirror therapy a mirror is positioned orthogonally in front of the center of the patient’s body. The less-affected (healthy extremity is moved and observed in the mirror. The purpose of this study was to determine the effect of mirror visual feedback on improving hand functions in children with hemiparesis. Methods: Forty children with hemiparesis of both sexes, ranged in age from five to seven years old, participated in this study. They were divided randomly into two groups of equal number (control and study. The control group received a specially designed physical therapy exercise program for four successive weeks while the study group received mirror exercise program in addition to the same program of the control group. Hand functions assessments was done using grasping and object manipulation subtests of Peabody developmental motor scale (PDMS-2. Evaluation was performed pre and post treatment program. Results:There was no significant difference between both groups in the pre-treatment mean values of all measured variables. Also, the results of this study revealed a significant improvement in the scores of the PDMS-2 andin grasp strength of the 2 groups. Post treatment results revealed more improvement in favor of the study group as compared with the control group. Conclusion: Using the mirror visual feedback could help in improving hand functions in children with hemiparesis.

  20. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans.

    Science.gov (United States)

    Wilkinson, Laura L; Ferriday, Danielle; Bosworth, Matthew L; Godinot, Nicolas; Martin, Nathalie; Rogers, Peter J; Brunstrom, Jeffrey M

    2016-01-01

    Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300 ml or 500 ml) x 2 (amount eaten; 300 ml or 500 ml) between-subjects design was employed (10 participants in each condition). In two 'congruent' conditions, the same amount was seen at the outset and then subsequently consumed (300 ml or 500 ml). To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional 'incongruent' conditions, in which 300 ml was seen but 500 ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second) was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300 ml or 500 ml). By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300 ml but actually consumed 500 ml ate at a faster rate than participants who saw 500 ml but actually consumed 300 ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation.

  1. Keeping Pace with Your Eating: Visual Feedback Affects Eating Rate in Humans

    Science.gov (United States)

    Bosworth, Matthew L.; Godinot, Nicolas; Martin, Nathalie; Rogers, Peter J.; Brunstrom, Jeffrey M.

    2016-01-01

    Deliberately eating at a slower pace promotes satiation and eating quickly has been associated with a higher body mass index. Therefore, understanding factors that affect eating rate should be given high priority. Eating rate is affected by the physical/textural properties of a food, by motivational state, and by portion size and palatability. This study explored the prospect that eating rate is also influenced by a hitherto unexplored cognitive process that uses ongoing perceptual estimates of the volume of food remaining in a container to adjust intake during a meal. A 2 (amount seen; 300ml or 500ml) x 2 (amount eaten; 300ml or 500ml) between-subjects design was employed (10 participants in each condition). In two ‘congruent’ conditions, the same amount was seen at the outset and then subsequently consumed (300ml or 500ml). To dissociate visual feedback of portion size and actual amount consumed, food was covertly added or removed from a bowl using a peristaltic pump. This created two additional ‘incongruent’ conditions, in which 300ml was seen but 500ml was eaten or vice versa. We repeated these conditions using a savoury soup and a sweet dessert. Eating rate (ml per second) was assessed during lunch. After lunch we assessed fullness over a 60-minute period. In the congruent conditions, eating rate was unaffected by the actual volume of food that was consumed (300ml or 500ml). By contrast, we observed a marked difference across the incongruent conditions. Specifically, participants who saw 300ml but actually consumed 500ml ate at a faster rate than participants who saw 500ml but actually consumed 300ml. Participants were unaware that their portion size had been manipulated. Nevertheless, when it disappeared faster or slower than anticipated they adjusted their rate of eating accordingly. This suggests that the control of eating rate involves visual feedback and is not a simple reflexive response to orosensory stimulation. PMID:26828922

  2. Strategies to improve effectiveness of physical activity coaching systems: Development of personas for providing tailored feedback.

    Science.gov (United States)

    Achterkamp, Reinoud; Dekker-Van Weering, Marit Gh; Evering, Richard Mh; Tabak, Monique; Timmerman, Josien G; Hermens, Hermie J; Vollenbroek-Hutten, Miriam Mr

    2016-06-27

    Mobile physical activity interventions can be improved by incorporating behavioural change theories. Relations between self-efficacy, stage of change, and physical activity are investigated, enabling development of feedback strategies that can be used to improve their effectiveness. A total of 325 healthy control participants and 82 patients wore an activity monitor. Participants completed a self-efficacy or stage of change questionnaire. Results show that higher self-efficacy is related to higher activity levels. Patients are less active than healthy controls and show a larger drop in physical activity over the day. Patients in the maintenance stage of change are more active than patients in lower stages of change, but show an equally large drop in level of physical activity. Findings suggest that coaching should at least be tailored to level of self-efficacy, stage of change, and physical activity pattern. Tailored coaching strategies are developed, which suggest that increasing self-efficacy of users is most important. Guidelines are provided. © The Author(s) 2016.

  3. Effectiveness of a training program in supervisors' ability to provide feedback on residents' communication skills.

    Science.gov (United States)

    Junod Perron, Noelle; Nendaz, Mathieu; Louis-Simonet, Martine; Sommer, Johanna; Gut, Anne; Baroffio, Anne; Dolmans, Diana; van der Vleuten, Cees

    2013-12-01

    Teaching communication skills (CS) to residents during clinical practice remains problematic. Direct observation followed by feedback is a powerful way to teach CS in clinical practice. However, little is known about the effect of training on feedback skills in this field. Controlled studies are scarce as well as studies that go beyond self-reported data. The aim of the study was to develop and assess the effectiveness of a training program for clinical supervisors on how to give feedback on residents' CS in clinical practice. The authors designed a pretest-posttest controlled study in which clinical supervisors working in two different medical services were invited to attend a sequenced and multifaceted program in teaching CS over a period of 6-9 months. Outcome measures were self-perceived and observed feedback skills collected during questionnaires and three videotaped objective structured teaching encounters. The videotaped feedbacks made by the supervisors were analysed using a 20-item feedback rating instrument. Forty-eight clinical supervisors participated (28 in the intervention, 20 in the control group). After training, a higher percentage of trained participants self-reported and demonstrated statistically significant improvement in making residents more active by exploring residents' needs, stimulating self-assessment, and using role playing to test strategies and checking understanding, with effect sizes ranging from 0.93 to 4.94. A training program on how to give feedback on residents' communication skills was successful in improving clinical supervisors' feedback skills and in helping them operate a shift from a teacher-centered to a more learner-centered approach.

  4. Feedback from higher to lower visual areas for visual recognition may be weaker in the periphery: Glimpses from the perception of brief dichoptic stimuli.

    Science.gov (United States)

    Zhaoping, Li

    2017-07-01

    Eye movements bring attended visual inputs to the center of vision for further processing. Thus, central and peripheral vision should have different functional roles. Here, we use observations of visual perception under dichoptic stimuli to infer that there is a difference in the top-down feedback from higher brain centers to primary visual cortex. Visual stimuli to the two eyes were designed such that the sum and difference of the binocular input from the two eyes have the form of two different gratings. These gratings differed in their motion direction, tilt direction, or color, and duly evoked ambiguous percepts for the corresponding feature. Observers were more likely to perceive the feature in the binocular summation rather than the difference channel. However, this perceptual bias towards the binocular summation signal was weaker or absent in peripheral vision, even when central and peripheral vision showed no difference in contrast sensitivity to the binocular summation signal relative to that to the binocular difference signal. We propose that this bias can arise from top-down feedback as part of an analysis-by-synthesis computation. The feedback is of the input predicted using prior information by the upper level perceptual hypothesis about the visual scene; the hypothesis is verified by comparing the feedback with the actual visual input. We illustrate this process using a conceptual circuit model. In this framework, a bias towards binocular summation can arise from the prior knowledge that inputs are usually correlated between the two eyes. Accordingly, a weaker bias in the periphery implies that the top-down feedback is weaker there. Testable experimental predictions are presented and discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Hardware Implementation of a Spline-Based Genetic Algorithm for Embedded Stereo Vision Sensor Providing Real-Time Visual Guidance to the Visually Impaired

    Directory of Open Access Journals (Sweden)

    James K. Archibald

    2008-04-01

    Full Text Available Many image and signal processing techniques have been applied to medical and health care applications in recent years. In this paper, we present a robust signal processing approach that can be used to solve the correspondence problem for an embedded stereo vision sensor to provide real-time visual guidance to the visually impaired. This approach is based on our new one-dimensional (1D spline-based genetic algorithm to match signals. The algorithm processes image data lines as 1D signals to generate a dense disparity map, from which 3D information can be extracted. With recent advances in electronics technology, this 1D signal matching technique can be implemented and executed in parallel in hardware such as field-programmable gate arrays (FPGAs to provide real-time feedback about the environment to the user. In order to complement (not replace traditional aids for the visually impaired such as canes and Seeing Eyes dogs, vision systems that provide guidance to the visually impaired must be affordable, easy to use, compact, and free from attributes that are awkward or embarrassing to the user. “Seeing Eye Glasses,” an embedded stereo vision system utilizing our new algorithm, meets all these requirements.

  6. Hardware Implementation of a Spline-Based Genetic Algorithm for Embedded Stereo Vision Sensor Providing Real-Time Visual Guidance to the Visually Impaired

    Science.gov (United States)

    Lee, Dah-Jye; Anderson, Jonathan D.; Archibald, James K.

    2008-12-01

    Many image and signal processing techniques have been applied to medical and health care applications in recent years. In this paper, we present a robust signal processing approach that can be used to solve the correspondence problem for an embedded stereo vision sensor to provide real-time visual guidance to the visually impaired. This approach is based on our new one-dimensional (1D) spline-based genetic algorithm to match signals. The algorithm processes image data lines as 1D signals to generate a dense disparity map, from which 3D information can be extracted. With recent advances in electronics technology, this 1D signal matching technique can be implemented and executed in parallel in hardware such as field-programmable gate arrays (FPGAs) to provide real-time feedback about the environment to the user. In order to complement (not replace) traditional aids for the visually impaired such as canes and Seeing Eyes dogs, vision systems that provide guidance to the visually impaired must be affordable, easy to use, compact, and free from attributes that are awkward or embarrassing to the user. "Seeing Eye Glasses," an embedded stereo vision system utilizing our new algorithm, meets all these requirements.

  7. When visuo-motor incongruence aids motor performance : the effect of perceiving motion structures during transformed visual feedback on bimanual coordination

    NARCIS (Netherlands)

    Bogaerts, H; Buekers, MJ; Zaal, FT; Swinnen, SP

    2003-01-01

    Two experiments are reported in which bimanual coordination tasks were performed under correct and transformed visual feedback conditions. Participants were to generate cyclical line-drawing patterns, with varying degrees of coordinative stability, while perceiving correct or transformed visual

  8. Technology-Assisted Rehabilitation of Writing Skills in Parkinson’s Disease: Visual Cueing versus Intelligent Feedback

    Directory of Open Access Journals (Sweden)

    Evelien Nackaerts

    2017-01-01

    Full Text Available Recent research showed that visual cueing can have both beneficial and detrimental effects on handwriting of patients with Parkinson’s disease (PD and healthy controls depending on the circumstances. Hence, using other sensory modalities to deliver cueing or feedback may be a valuable alternative. Therefore, the current study compared the effects of short-term training with either continuous visual cues or intermittent intelligent verbal feedback. Ten PD patients and nine healthy controls were randomly assigned to one of these training modes. To assess transfer of learning, writing performance was assessed in the absence of cueing and feedback on both trained and untrained writing sequences. The feedback pen and a touch-sensitive writing tablet were used for testing. Both training types resulted in improved writing amplitudes for the trained and untrained sequences. In conclusion, these results suggest that the feedback pen is a valuable tool to implement writing training in a tailor-made fashion for people with PD. Future studies should include larger sample sizes and different subgroups of PD for long-term training with the feedback pen.

  9. Grading by Category: A simple method for providing students with meaningful feedback on exams in large courses

    CERN Document Server

    Paul, Cassandra; Weiss, Brenda

    2013-01-01

    Many instructors choose to assess their students using open-ended written exam items that require students to show their understanding of physics by solving a problem and/or explaining a concept. Grading these items is fairly time consuming, and in large courses time constraints prohibit providing significant individualized feedback on students' exams. Instructors typically cross out areas of the response that are incorrect and write the total points awarded or subtracted. Sometimes, instructors will also write a word or two to indicate the error. This paper describes a grading method that provides greater individualized feedback, clearly communicates to students expected performance levels, takes no more time than traditional grading methods for open-ended responses, and seems to encourage more students to take advantage of the feedback provided.

  10. Encouraging Electricity Savings in a University Residential Hall through a Combination of Feedback, Visual Prompts, and Incentives

    Science.gov (United States)

    Bekker, Marthinus J.; Cumming, Tania D.; Osborne, Nikola K. P.; Bruining, Angela M.; McClean, Julia I.; Leland, Louis S., Jr.

    2010-01-01

    This experiment investigated the combined use of visual prompts, daily feedback, and rewards to reduce electricity consumption in a university residential hall. After a 17-day baseline period, the experimental intervention was introduced in the intervention hall, and no change was made in the control hall. Energy usage decreased in the…

  11. Real-Time Visual Feedback for Learning to Perform Short Rhythms with Variations in Timing and Loudness

    NARCIS (Netherlands)

    Sadakata, M.; Hoppe, D.; Brandmeyer, A.; Timmers, R.; Desain, P.W.M.

    2008-01-01

    According to learning theories and empirical observations, communication between teachers and students is a crucial factor in effective learning of musical expressions. One possibility for improving this communication could be the introduction of visual feedback (VFB) in the lesson. In the current

  12. Reflections on Mirror Therapy: A Systematic Review of the Effect of Mirror Visual Feedback on the Brain.

    NARCIS (Netherlands)

    Deconinck, F.J.; Smorenburg, A.R.P.; Benham, A.; Ledebt, A.; Feltham, M.; Savelsbergh, G.J.P.

    2014-01-01

    Background. Mirror visual feedback (MVF), a phenomenon where movement of one limb is perceived as movement of the other limb, has the capacity to alleviate phantom limb pain or promote motor recovery of the upper limbs after stroke. The tool has received great interest from health professionals;

  13. The Effects of Task Clarification, Visual Prompts, and Graphic Feedback on Customer Greeting and Up-Selling in a Restaurant

    Science.gov (United States)

    Squires, James; Wilder, David A.; Fixsen, Amanda; Hess, Erica; Rost, Kristen; Curran, Ryan; Zonneveld, Kimberly

    2007-01-01

    An intervention consisting of task clarification, visual prompts, and graphic feedback was evaluated to increase customer greeting and up-selling in a restaurant. A combination multiple baseline and reversal design was used to evaluate intervention effects. Although all interventions improved performance over baseline, the delivery of graphic…

  14. Effects of visual center of pressure feedback on postural control in young and elderly healthy adults and in stroke patients

    NARCIS (Netherlands)

    Dault, Mylène C.; de Haart, Mirjam; Geurts, Alexander C. H.; Arts, Ilse M. P.; Nienhuis, Bart

    2003-01-01

    The goal of this study was to compare young and elderly healthy individuals and elderly stroke patients in their capacity to use visual CP feedback (VF) in controlling both quiet standing and weight shifting and to assess their sensory re-weighing when this VF is withdrawn. A total of 40

  15. A Surgical Robot Teleoperation Framework for Providing Haptic Feedback Incorporating Virtual Envrioment-Based Guidance

    Directory of Open Access Journals (Sweden)

    Adnan Munawar

    2016-08-01

    Full Text Available In robot-assisted tele-operated laparoscopic surgeries, the patient side manipulators are controlled via the master manipulators that are controlled by the surgeon. The current generation of robots approved for laparoscopic surgery lack haptic feedback. In theory, haptic feedback would enhance the surgical procedures by enabling better coordination between the hand movements that are improved by the tactile sense of the operating environment. This research presents an overall control framework for a haptic feedback on existing robot platforms, and demonstrated on the daVinci Research Kit (dVRK system. The paper discusses the implementation of a flexible framework that incorporates a stiffness control with gravity compensation for the surgeons manipulator and a sensing and collision detection algorithm for calculating the interaction between the patients manipulators and the surgical area.

  16. Visual Feedback of the Non-Moving Limb Improves Active Joint-Position Sense of the Impaired Limb in Spastic Hemiparetic Cerebral Palsy

    Science.gov (United States)

    Smorenburg, Ana R. P.; Ledebt, Annick; Deconinck, Frederik J. A.; Savelsbergh, Geert J. P.

    2011-01-01

    This study examined the active joint-position sense in children with Spastic Hemiparetic Cerebral Palsy (SHCP) and the effect of static visual feedback and static mirror visual feedback, of the non-moving limb, on the joint-position sense. Participants were asked to match the position of one upper limb with that of the contralateral limb. The task…

  17. Evidence that baroreflex feedback influences long-term incidental visual memory in men.

    Science.gov (United States)

    Moor, Tobias; Mundorff, Lukas; Bohringer, Andreas; Philippsen, Christine; Langewitz, Wolf; Reino, Silvia Tenés; Schachinger, Hartmut

    2005-11-01

    Sympathetic nervous system (SNS) activity at the time of acquisition is associated with human memory. However, rather than SNS activity per se, it may be afferent baroreflex feedback that is responsible for this effect. A pharmacological design was employed to unload (SNP, sodium nitro-prusside) and load (norepinephrine) baroreceptors. In addition to two placebo periods, epinephrine and esmolol (a peripherally acting beta1-blocker) served as control conditions for altered cardiac perception. During drug infusion blood pressure, heart rate, and perception of heartbeat were tested. Twenty-four healthy men were participated. The participants viewed emotional slides while their electromyographic eye blink responses to random noise bursts were measured (affective startle modulation paradigm) to determine potential drug impact on emotional processing. Subjects were not informed that memory testing would take place after 4 weeks. Drugs did not impact startle, thus indicating unbiased emotional processing at the time of acquisition. Norepinephrine had no effect on heartbeat perception, but improved (p = .002) recognition memory. SNP (p = .0001) increased heartbeat perception but impaired (p = .038) recognition memory. Epinephrine, on the other hand, increased heartbeat perception (p = .0001) yet did not impair but partially improve memory (effect on high arousing pictures only: p = .05). Heartbeat perception in the placebo condition did not correlate with recognition memory (p's > .5). We suggest that baroreflex unloading, with subsequent feedback activation of the SNS, impairs long-term incidental visual recognition memory in humans while baroreflex loading enhances it. Further, we propose that these memory effects are neither secondary to cardiac sensations that accompany SNS activation nor to altered emotional picture processing at the time of acquisition.

  18. Providing Graduated Corrective Feedback in an Intelligent Computer-Assisted Language Learning Environment

    Science.gov (United States)

    Ai, Haiyang

    2017-01-01

    Corrective feedback (CF), a response to linguistic errors made by second language (L2) learners, has received extensive scholarly attention in second language acquisition. While much of the previous research in the field has focused on whether CF facilitates or impedes L2 development, few studies have examined the efficacy of gradually modifying…

  19. Strategies to improve effectiveness of physical activity coaching systems: Development of personas for providing tailored feedback

    NARCIS (Netherlands)

    Achterkamp, Reinoud; van Weering, Marit; Evering, R.M.H.; Tabak, Monique; Timmerman, Josien; Hermens, Hermanus J.; Vollenbroek-Hutten, Miriam Marie Rosé

    2017-01-01

    Mobile physical activity interventions can be improved by incorporating behavioural change theories. Relations between self-efficacy, stage of change, and physical activity are investigated, enabling development of feedback strategies that can be used to improve their effectiveness. A total of 325

  20. Providing Feedback on Computer-Based Algebra Homework in Middle-School Classrooms

    Science.gov (United States)

    Fyfe, Emily R.

    2016-01-01

    Homework is transforming at a rapid rate with continuous advances in educational technology. Computer-based homework, in particular, is gaining popularity across a range of schools, with little empirical evidence on how to optimize student learning. The current aim was to test the effects of different types of feedback on computer-based homework.…

  1. Effect of visual feedback on the occipito-parietal-motor network in Parkinson's disease patients with freezing of gait

    Directory of Open Access Journals (Sweden)

    Priya D Velu

    2014-01-01

    Full Text Available Freezing of gait (FOG is an elusive phenomenon that debilitates a large number of Parkinson’s disease (PD patients regardless of stage of disease, medication status, or DBS implantation. Sensory cues, especially visual feedback cues, have been shown to alleviate FOG episodes or prevent episodes from even occurring. Here, we examine cortical information flow between occipital, parietal, and motor areas during the pre-movement stage of gait in a PD-with-FOG patient that had a strong positive behavioral response to visual cues, a PD-with-FOG patient without any behavioral response to visual cues, and an age-matched healthy control, before and after training with visual feedback. Results for this case study show differences in cortical information flow between the responding PD-with-FOG patient and the other two subjects, notably, an increased information flow in the beta range. Tentatively suggesting the formation of an alternative cortical sensory-motor pathway during training with visual feedback, these results are proposed as subject for further verification employing larger cohorts of patients.

  2. Muscle activation during resistance training with no external load - effects of training status, movement velocity, dominance, and visual feedback.

    Science.gov (United States)

    Gentil, Paulo; Bottaro, Martim; Noll, Matias; Werner, Scott; Vasconcelos, Jessica Cabral; Seffrin, Aldo; Campos, Mario Hebling

    2017-10-01

    To explore the acute effects of training status, movement velocity, dominance, and visual feedback on muscle activation and rating of perceived exertion (RPE) during resistance training with no external load (no-load resistance training; NLRT). Thirty-three men (17 untrained and 16 trained), performed elbow flexions in four NLRT sessions: 1) slow velocity with EMG visual feedback, 2) slow velocity without EMG visual feedback, 3) fast velocity with EMG feedback, and 4) fast velocity without EMG feedback. RPE was measured using the Borg Discomfort scale. EMG for the biceps and triceps were recorded for both arms. EMG feedback had no influence on RPE. The peak and mean EMG values were not different for the biceps (93.8±11.5% and 50±13.1%) and triceps (93.7±23.9% and 49.6±16.2%). The results revealed a difference in the training status, with higher peak EMG for untrained than for trained participants (96.9±20% vs. 90.2±15.6%). However the values for mean EMG were not different between the untrained and trained (50.3±15.7% vs. 49.2±13.7%) participants. There was no difference in the peak (92.8±19% vs. 94.7±20.4%) and mean (49.8±15.0% vs. 49.7±14.5%) EMG values for the dominant and non-dominant sides. Peak EMG values were not different between faster and slower velocities (93.6±19.6% and 93.9±17.8%). However, mean EMG was higher for slower (50.5±14.4%) than for faster (48.5±15.4%) velocities. The peak and mean EMG during contractions with (93.3±17.5% and 49.5±14.1%) and without visual feedback (94.2±19.9% and 50±15.4%) were not significantly different. NLRT produces high levels of muscle activation independent of training, status, dominance, movement velocity, and visual feedback. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Attention to Color Sharpens Neural Population Tuning via Feedback Processing in the Human Visual Cortex Hierarchy.

    Science.gov (United States)

    Bartsch, Mandy V; Loewe, Kristian; Merkel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Tsotsos, John K; Hopf, Jens-Max

    2017-10-25

    Attention can facilitate the selection of elementary object features such as color, orientation, or motion. This is referred to as feature-based attention and it is commonly attributed to a modulation of the gain and tuning of feature-selective units in visual cortex. Although gain mechanisms are well characterized, little is known about the cortical processes underlying the sharpening of feature selectivity. Here, we show with high-resolution magnetoencephalography in human observers (men and women) that sharpened selectivity for a particular color arises from feedback processing in the human visual cortex hierarchy. To assess color selectivity, we analyze the response to a color probe that varies in color distance from an attended color target. We find that attention causes an initial gain enhancement in anterior ventral extrastriate cortex that is coarsely selective for the target color and transitions within ∼100 ms into a sharper tuned profile in more posterior ventral occipital cortex. We conclude that attention sharpens selectivity over time by attenuating the response at lower levels of the cortical hierarchy to color values neighboring the target in color space. These observations support computational models proposing that attention tunes feature selectivity in visual cortex through backward-propagating attenuation of units less tuned to the target.SIGNIFICANCE STATEMENT Whether searching for your car, a particular item of clothing, or just obeying traffic lights, in everyday life, we must select items based on color. But how does attention allow us to select a specific color? Here, we use high spatiotemporal resolution neuromagnetic recordings to examine how color selectivity emerges in the human brain. We find that color selectivity evolves as a coarse to fine process from higher to lower levels within the visual cortex hierarchy. Our observations support computational models proposing that feature selectivity increases over time by attenuating the

  4. Impact of online visual feedback on motor acquisition and retention when learning to reach in a force field.

    Science.gov (United States)

    Batcho, C S; Gagné, M; Bouyer, L J; Roy, J S; Mercier, C

    2016-11-19

    When subjects learn a novel motor task, several sources of feedback (proprioceptive, visual or auditory) contribute to the performance. Over the past few years, several studies have investigated the role of visual feedback in motor learning, yet evidence remains conflicting. The aim of this study was therefore to investigate the role of online visual feedback (VFb) on the acquisition and retention stages of motor learning associated with training in a reaching task. Thirty healthy subjects made ballistic reaching movements with their dominant arm toward two targets, on 2 consecutive days using a robotized exoskeleton (KINARM). They were randomly assigned to a group with (VFb) or without (NoVFb) VFb of index position during movement. On day 1, the task was performed before (baseline) and during the application of a velocity-dependent resistive force field (adaptation). To assess retention, participants repeated the task with the force field on day 2. Motor learning was characterized by: (1) the final endpoint error (movement accuracy) and (2) the initial angle (iANG) of deviation (motor planning). Even though both groups showed motor adaptation, the NoVFb-group exhibited slower learning and higher final endpoint error than the VFb-group. In some condition, subjects trained without visual feedback used more curved initial trajectories to anticipate for the perturbation. This observation suggests that learning to reach targets in a velocity-dependent resistive force field is possible even when feedback is limited. However, the absence of VFb leads to different strategies that were only apparent when reaching toward the most challenging target. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Mirror visual feedback-induced performance improvement and the influence of hand dominance

    Directory of Open Access Journals (Sweden)

    Viola eRjosk

    2016-01-01

    Full Text Available Mirror Visual Feedback (MVF is a promising technique in clinical settings that can be used to augment performance of an untrained limb. Several studies with healthy volunteers and patients using transcranial magnetic stimulation (TMS or functional magnetic resonance imaging (fMRI indicate that functional alterations within primary motor cortex (M1 might be one candidate mechanism that could explain MVF-induced changes in behavior. Until now, most studies have used MVF to improve performance of the non-dominant hand. The question remains if the behavioural effect of MVF differs according to hand dominance. Here, we conducted a study with two groups of young, healthy right-handed volunteers who performed a complex ball-rotation task while receiving MVF of the dominant (n = 16, group 1, MVFDH or non-dominant hand (n = 16, group 2, MVFNDH. We found no significant differences in baseline performance of the untrained hand between groups before MVF was applied. Furthermore, there was no significant difference in the amount of performance improvement between MVFDH and MVFNDH indicating that the outcome of MVF seems not to be influenced by hand dominance. Thus our findings might have important implications in neurorehabilitation suggesting that patients suffering from unilateral motor impairments might benefit from MVF regardless of the dominance of the affected limb.

  6. Using Audience Response Technology to provide formative feedback on pharmacology performance for non-medical prescribing students - a preliminary evaluation

    Directory of Open Access Journals (Sweden)

    Mostyn Alison

    2012-11-01

    individualised handsets and personalised formative feedback highly. The significant correlation between ART response scores and student exam scores suggests that formative feedback can provide students with a useful reference point in terms of their level of exam-readiness.

  7. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a "natural" grasping task induces pantomime-like grasps.

    Science.gov (United States)

    Whitwell, Robert L; Ganel, Tzvi; Byrne, Caitlin M; Goodale, Melvyn A

    2015-01-01

    past. Compared to natural grasps, removing tactile feedback increased RT, slowed the velocity of the reach, reduced in-flight grip aperture, increased the slopes relating grip aperture to target width, and reduced the final grip aperture (FGA). All of these effects were also observed in the real time-pantomime grasping task. These effects seem to be independent of those that arise from using the mirror in general as we also compared grasps directed towards virtual targets to those directed at real ones viewed directly through a pane of glass. These comparisons showed that the grasps directed at virtual targets increased grip aperture, slowed the velocity of the reach, and reduced the slopes relating grip aperture to the widths of the target. Thus, using the mirror has real consequences on grasp kinematics, reflecting the importance of task-relevant sources of online visual information for the programming and updating of natural prehensile movements. Taken together, these results provide compelling support for the view that removing terminal tactile feedback, even when the grasps are target-directed, induces a switch from real-time visual control towards one that depends more on visual perception and cognitive supervision. Providing terminal tactile feedback and real-time visual information can evidently keep the dorsal visuomotor system operating normally for prehensile acts.

  8. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a “natural” grasping task induces pantomime-like grasps

    Science.gov (United States)

    Whitwell, Robert L.; Ganel, Tzvi; Byrne, Caitlin M.; Goodale, Melvyn A.

    2015-01-01

    laboratory in the past. Compared to natural grasps, removing tactile feedback increased RT, slowed the velocity of the reach, reduced in-flight grip aperture, increased the slopes relating grip aperture to target width, and reduced the final grip aperture (FGA). All of these effects were also observed in the real time-pantomime grasping task. These effects seem to be independent of those that arise from using the mirror in general as we also compared grasps directed towards virtual targets to those directed at real ones viewed directly through a pane of glass. These comparisons showed that the grasps directed at virtual targets increased grip aperture, slowed the velocity of the reach, and reduced the slopes relating grip aperture to the widths of the target. Thus, using the mirror has real consequences on grasp kinematics, reflecting the importance of task-relevant sources of online visual information for the programming and updating of natural prehensile movements. Taken together, these results provide compelling support for the view that removing terminal tactile feedback, even when the grasps are target-directed, induces a switch from real-time visual control towards one that depends more on visual perception and cognitive supervision. Providing terminal tactile feedback and real-time visual information can evidently keep the dorsal visuomotor system operating normally for prehensile acts. PMID:25999834

  9. Can providing feedback on driving behavior and training on parental vigilant care affect male teen drivers and their parents?

    Science.gov (United States)

    Farah, Haneen; Musicant, Oren; Shimshoni, Yaara; Toledo, Tomer; Grimberg, Einat; Omer, Haim; Lotan, Tsippy

    2014-08-01

    This study focuses on investigating the driving behavior of young novice male drivers during the first year of driving (three months of accompanied driving and the following nine months of solo driving). The study's objective is to examine the potential of various feedback forms on driving to affect young drivers' behavior and to mitigate the transition from accompanied to solo driving. The study examines also the utility of providing parents with guidance on how to exercise vigilant care regarding their teens' driving. Driving behavior was evaluated using data collected by In-Vehicle Data Recorders (IVDR), which document events of extreme g-forces measured in the vehicles. IVDR systems were installed in 242 cars of the families of young male drivers, however, only 217 families of young drivers aged 17-22 (M=17.5; SD=0.8) completed the one year period. The families were randomly allocated into 4 groups: (1) Family feedback: In which all the members of the family were exposed to feedback on their own driving and on that of the other family members; (2) Parental training: in which in addition to the family feedback, parents received personal guidance on ways to enhance vigilant care regarding their sons' driving; (3) Individual feedback: In which family members received feedback only on their own driving behavior (and were not exposed to the data on other family members); (4) CONTROL: Group that received no feedback at all. The feedback was provided to the different groups starting from the solo period, thus, the feedback was not provided during the supervised period. The data collected by the IVDRs was first analyzed using analysis of variance in order to compare the groups with respect to their monthly event rates. Events' rates are defined as the number of events in a trip divided by its duration. This was followed by the development and estimation of random effect negative binomial models that explain the monthly event rates of young drivers and their parents

  10. Online kinematic regulation by visual feedback for grasp versus transport during reach-to-pinch.

    Science.gov (United States)

    Nataraj, Raviraj; Pasluosta, Cristian; Li, Zong-Ming

    2014-08-01

    This study investigated novel kinematic performance parameters to understand regulation by visual feedback (VF) of the reaching hand on the grasp and transport components during the reach-to-pinch maneuver. Conventional metrics often signify discrete movement features to postulate sensory-based control effects (e.g., time for maximum velocity to signify feedback delay). The presented metrics of this study were devised to characterize relative vision-based control of the sub-movements across the entire maneuver. Movement performance was assessed according to reduced variability and increased efficiency of kinematic trajectories. Variability was calculated as the standard deviation about the observed mean trajectory for a given subject and VF condition across kinematic derivatives for sub-movements of inter-pad grasp (distance between thumb and index finger-pads; relative orientation of finger-pads) and transport (distance traversed by wrist). A Markov analysis then examined the probabilistic effect of VF on which movement component exhibited higher variability over phases of the complete maneuver. Jerk-based metrics of smoothness (minimal jerk) and energy (integrated jerk-squared) were applied to indicate total movement efficiency with VF. The reductions in grasp variability metrics with VF were significantly greater (pjerk, suggesting separate control pathways for each component. The Markov analysis indicated that VF preferentially regulates grasp over transport when continuous control is modeled probabilistically during the movement. Efficiency measures demonstrated VF to be more integral for early motor planning of grasp than transport in producing greater increases in smoothness and trajectory adjustments (i.e., jerk-energy) early compared to late in the movement cycle. These findings demonstrate the greater regulation by VF on kinematic performance of grasp compared to transport and how particular features of this relativistic control occur continually over the

  11. Randomized crossover trial of a pressure sensing visual feedback system to improve mask fitting in noninvasive ventilation.

    Science.gov (United States)

    Brill, Anne-Kathrin; Moghal, Mohammad; Morrell, Mary J; Simonds, Anita K

    2017-10-01

    A good mask fit, avoiding air leaks and pressure effects on the skin are key elements for a successful noninvasive ventilation (NIV). However, delivering practical training for NIV is challenging, and it takes time to build experience and competency. This study investigated whether a pressure sensing system with real-time visual feedback improved mask fitting. During an NIV training session, 30 healthcare professionals (14 trained in mask fitting and 16 untrained) performed two mask fittings on the same healthy volunteer in a randomized order: one using standard mask-fitting procedures and one with additional visual feedback on mask pressure on the nasal bridge. Participants were required to achieve a mask fit with low mask pressure and minimal air leak (bridge, perceived comfort of mask fit and staff- confidence were measured. Compared with standard mask fitting, a lower pressure was exerted on the nasal bridge using the feedback system (71.1 ± 17.6 mm Hg vs 63.2 ± 14.6 mm Hg, P bridge (74.5 ± 21.2 mm Hg vs 66.1 ± 17.4 mm Hg, P = 0.023 and 67 ± 12.1 mm Hg vs 60 ± 10.6 mm Hg, P = 0.002, respectively) using the feedback system and self-rated confidence increased in the untrained group. Real-time visual feedback using pressure sensing technology supported healthcare professionals during mask-fitting training, resulted in a lower pressure on the skin and better mask fit for the volunteer, with increased staff confidence. © 2017 Asian Pacific Society of Respirology.

  12. Interactive balance training integrating sensor-based visual feedback of movement performance: a pilot study in older adults.

    Science.gov (United States)

    Schwenk, Michael; Grewal, Gurtej S; Honarvar, Bahareh; Schwenk, Stefanie; Mohler, Jane; Khalsa, Dharma S; Najafi, Bijan

    2014-12-13

    Wearable sensor technology can accurately measure body motion and provide incentive feedback during exercising. The aim of this pilot study was to evaluate the effectiveness and user experience of a balance training program in older adults integrating data from wearable sensors into a human-computer interface designed for interactive training. Senior living community residents (mean age 84.6) with confirmed fall risk were randomized to an intervention (IG, n = 17) or control group (CG, n = 16). The IG underwent 4 weeks (twice a week) of balance training including weight shifting and virtual obstacle crossing tasks with visual/auditory real-time joint movement feedback using wearable sensors. The CG received no intervention. Outcome measures included changes in center of mass (CoM) sway, ankle and hip joint sway measured during eyes open (EO) and eyes closed (EC) balance test at baseline and post-intervention. Ankle-hip postural coordination was quantified by a reciprocal compensatory index (RCI). Physical performance was quantified by the Alternate-Step-Test (AST), Timed-up-and-go (TUG), and gait assessment. User experience was measured by a standardized questionnaire. After the intervention sway of CoM, hip, and ankle were reduced in the IG compared to the CG during both EO and EC condition (p = .007-.042). Improvement was obtained for AST (p = .037), TUG (p = .024), fast gait speed (p = . 010), but not normal gait speed (p = .264). Effect sizes were moderate for all outcomes. RCI did not change significantly. Users expressed a positive training experience including fun, safety, and helpfulness of sensor-feedback. Results of this proof-of-concept study suggest that older adults at risk of falling can benefit from the balance training program. Study findings may help to inform future exercise interventions integrating wearable sensors for guided game-based training in home- and community environments. Future studies should evaluate the

  13. Feed-forward, feedback and lateral interactions in membrane potentials and spike trains from the visual cortex in vivo.

    Science.gov (United States)

    Eriksson, David; Roland, Per

    2006-01-01

    Neurons in the visual cortex receive input from the lateral geniculate nucleus (feed-forward), higher order visual areas (feedback) and local neurons in the surroundings (lateral interactions). Here we first briefly review the approximate timing and proportion of these three types of influences on the membrane potentials in visual areas 17, 18 and 19. Then we present original results from an independent component analysis of multiunit spike trains in the same visual areas to resolve the contribution from these three sources. We stimulated the visual cortex of the ferret with a small transient contrast square stimulus and recorded the multiunit activity in areas 17, 18 and 19 with single or multiple electrodes. The spike trains had three reproducible components having their maxima at 40, 55 and 105ms after the start of the presentation of the stimulus. The time course of the third component was significantly correlated with the population membrane potential in the supragranular layers of areas 17, 18 and 19. The first spike train component was interpreted as a feed-forward response, the second spike train component as driving the laterally spreading depolarization and the third spike train component as the firing caused by the lateral spreading- and the feedback depolarization.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Maryam Alimardani

    Full Text Available 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.

  16. Preparing the leg for ground contact in running: the contribution of feed-forward and visual feedback.

    Science.gov (United States)

    Müller, Roy; Häufle, Daniel Florian Benedict; Blickhan, Reinhard

    2015-02-01

    While running on uneven ground, humans are able to negotiate visible but also camouflaged changes in ground level. Previous studies have shown that the leg kinematics before touch down change with ground level. The present study experimentally investigated the contributions of visual perception (visual feedback), proprioceptive feedback and feed-forward patterns to the muscle activity responsible for these adaptations. The activity of three bilateral lower limb muscles (m. gastrocnemius medialis, m. tibialis anterior and m. vastus medialis) of nine healthy subjects was recorded during running across visible (drop of 0, -5 and -10 cm) and camouflaged changes in ground level (drop of 0 and -10 cm). The results reveal that at touchdown with longer flight time, m. tibialis anterior activation decreases and m. vastus medialis activation increases purely by feed-forward driven (flight time-dependent) muscle activation patterns, while m. gastrocnemius medialis activation increase is additionally influenced by visual feedback. Thus, feed-forward driven muscle activation patterns are sufficient to explain the experimentally observed adjustments of the leg at touchdown. © 2015. Published by The Company of Biologists Ltd.

  17. Concurrent audio-visual feedback for supporting drivers at intersections : a study using two linked driving simulators.

    NARCIS (Netherlands)

    Houtenbos, M. Winter, J.C.F. de Hale, A.R. Wieringa, P.A. & Hagenzieker, M.P.

    2016-01-01

    A large portion of road traffic crashes occur at intersections for the reason that drivers lack necessary visual information. This research examined the effects of an audio-visual display that provides real-time sonification and visualization of the speed and direction of another car approaching the

  18. Replacing Voice Input with Technology that Provided Immediate Visual and Audio Feedback to Reduce Employee Errors

    Science.gov (United States)

    Goomas, David T.

    2010-01-01

    In this report from the field at two auto parts distribution centers, order selectors picked auto accessories (e.g., fuses, oil caps, tool kits) into industrial plastic totes as part of store orders. Accurately identifying all store order totes via the license plate number was a prerequisite for the warehouse management system (WMS) to track each…

  19. User-centered development and testing of a monitoring system that provides feedback regarding physical functioning to elderly people

    Directory of Open Access Journals (Sweden)

    Vermeulen J

    2013-08-01

    Full Text Available Joan Vermeulen,1 Jacques CL Neyens,1 Marieke D Spreeuwenberg,1 Erik van Rossum,1,2 Walther Sipers,3 Herbert Habets,3 David J Hewson,4 Luc P de Witte1,2 1School for Public Health and Primary Care (CAPHRI, Maastricht University, Maastricht, The Netherlands; 2Research Center for Technology in Care, Zuyd University of Applied Sciences, Heerlen, The Netherlands; 3Expertise Center for Elderly Care, Orbis Medical Center, Sittard, The Netherlands; 4Institute Charles Delaunay, Université de Technologie de Troyes, Troyes, France Purpose: To involve elderly people during the development of a mobile interface of a monitoring system that provides feedback to them regarding changes in physical functioning and to test the system in a pilot study. Methods and participants: The iterative user-centered development process consisted of the following phases: (1 selection of user representatives; (2 analysis of users and their context; (3 identification of user requirements; (4 development of the interface; and (5 evaluation of the interface in the lab. Subsequently, the monitoring and feedback system was tested in a pilot study by five patients who were recruited via a geriatric outpatient clinic. Participants used a bathroom scale to monitor weight and balance, and a mobile phone to monitor physical activity on a daily basis for six weeks. Personalized feedback was provided via the interface of the mobile phone. Usability was evaluated on a scale from 1 to 7 using a modified version of the Post-Study System Usability Questionnaire (PSSUQ; higher scores indicated better usability. Interviews were conducted to gain insight into the experiences of the participants with the system. Results: The developed interface uses colors, emoticons, and written and/or spoken text messages to provide daily feedback regarding (changes in weight, balance, and physical activity. The participants rated the usability of the monitoring and feedback system with a mean score of 5

  20. Oral proton pump inhibitors disrupt horizontal cell-cone feedback and enhance visual hallucinations in macular degeneration patients.

    Science.gov (United States)

    Hanneken, Anne M; Babai, Norbert; Thoreson, Wallace B

    2013-02-27

    Visual hallucinations (VHs) occur in macular degeneration patients with poor vision but normal cognitive function. The underlying mechanisms are poorly understood. We report the identification of pharmaceutical agents that enhance VH and use these agents to examine the contribution of retinal neurons to this syndrome. We detail clinical observations on VH in five macular degeneration patients treated with proton pump inhibitors having the core structure, 2-pyridyl-methylsulfinyl-benzimidazole. We tested possible retinal mechanisms using paired whole cell recordings to examine effects of these compounds on feedback interactions between horizontal cells and cones in amphibian retina. Five patients with advanced wet macular degeneration described patterned VHs that were induced or enhanced by oral proton pump inhibitors. The abnormal images increased with light, disappeared in the dark, and originated in the retina, based on ophthalmodynamometry. Simultaneous paired whole cell recordings from amphibian cones and horizontal cells showed that 2-pyridyl-methylsulfinyl-benzimidazoles blocked the negative shift in voltage dependence and increase in amplitude of the calcium current (ICa) in cones that is induced by changes in horizontal cell membrane potential. These effects disrupt the negative feedback from horizontal cells to cones that is important for the formation of center-surround receptive fields in bipolar and ganglion cells, and thus for normal spatial and chromatic perception. Our study suggests that changes in the output of retinal neurons caused by disturbances in outer retinal feedback mechanisms can enhance patterned visual hallucinations.

  1. Alpha-beta and gamma rhythms subserve feedback and feedforward influences among human visual cortical areas

    National Research Council Canada - National Science Library

    Michalareas, G; Vezoli, J; Pelt, S. van; Schoffelen, J.M; Kennedy, H; Fries, P

    2016-01-01

    ... inter-areal directed influences as measured with magnetoencephalography. We show that influences along feedforward projections predominate in the gamma band, whereas influences along feedback projections predominate in the alpha-beta band...

  2. Influence of Whole-Body Vibration Training Without Visual Feedback on Balance and Lower-Extremity Muscle Strength of the Elderly

    Science.gov (United States)

    Tseng, Shiuan-Yu; Lai, Chung-Liang; Chang, Kai-Ling; Hsu, Pi-Shan; Lee, Meng-Chih; Wang, Chun-Hou

    2016-01-01

    Abstract The purpose of this study was to investigate the influence of whole-body vibration (WBV) training without visual feedback on balance and lower-extremity muscle strength in the elderly. Elderly subjects who did not exercise regularly participated in this study. Subjects were randomly divided into a WBV with eyes open group, a visual feedback-deprived plus WBV (VFDWBV) group, and a control group (0 Hz, eyes open). WBV training was provided over a 3-month period, 3 times per week for 5 min each session. Balance performance was measured with the limits of stability test, and muscle strength was measured with an isokinetic dynamometer. A total of 45 elderly subjects with an average age of 69.22 ± 3.97 years, divided into a WBV group (n = 14), a VFDWBV group (n = 17), and a control group (n = 14), completed the trial. Statistically significant differences were found in the balance performance of the 3 groups at different time points (time × group interaction: F = 13.213, P strength of the knee extensor and flexor muscles had time × group interactions: F = 29.604, P lower-extremity muscle strength than the WBV and control groups. The 6-month follow-up showed that the rates of hospital visits for medical services due to falls were 0% in the WBV group (0/14), 0% in the VFDWBV group (0/17), and 28.57% in the control group (4/14). Results showed that WBV training at 20 Hz without visual feedback can significantly improve the balance performance and lower-extremity muscle strength of the elderly. PMID:26844514

  3. Smartphone-Based Visual Feedback Trunk Control Training Using a Gyroscope and Mirroring Technology for Stroke Patients: Single-blinded, Randomized Clinical Trial of Efficacy and Feasibility.

    Science.gov (United States)

    Shin, Doo Chul; Song, Chang Ho

    2016-05-01

    The purpose of this study was to assess the preliminary efficacy and feasibility of smartphone-based visual feedback trunk control training (SPVFTCT) for improving balance and trunk performance in stroke patients. Twenty-four patients who had experienced a stroke more than 6 months previously and could sit and walk independently participated in the study. The participants were allocated to a SPVFTCT (n = 12) or to a control group (n = 12). Both groups completed five 80-minute sessions per week of conventional rehabilitation for 4 weeks. The SPVFTCT group additionally received three 20-minute sessions per week of SPVFTCT for 4 weeks. The outcome was assessed using static balance assessment, the modified functional reach test, the timed up and go test, and the trunk impairment scale. Feasibility of SPVFTCT was evaluated by retention, adherence, acceptability, and safety. The static balance assessment, modified functional reach test, timed up and go test, and trunk impairment scale scores in the SPVFTCT group improved significantly compared to those in the control group (P performance in stroke patients. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES:: Upon completion of this article, the reader should be able to: (1) Understand the role of trunk control in postural stability and functional improvement; (2) Describe the benefits of smartphone-based visual feedback trunk control training (SPVFTCT); and (3)Discuss the feasibility of incorporating smartphone-based visual feedback trunk control training in stroke rehabilitation. Advanced : The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s). Physicians should only claim credit commensurate with the extent of their

  4. Influence of Whole-Body Vibration Training Without Visual Feedback on Balance and Lower-Extremity Muscle Strength of the Elderly: A Randomized Controlled Trial.

    Science.gov (United States)

    Tseng, Shiuan-Yu; Lai, Chung-Liang; Chang, Kai-Ling; Hsu, Pi-Shan; Lee, Meng-Chih; Wang, Chun-Hou

    2016-02-01

    The purpose of this study was to investigate the influence of whole-body vibration (WBV) training without visual feedback on balance and lower-extremity muscle strength in the elderly.Elderly subjects who did not exercise regularly participated in this study. Subjects were randomly divided into a WBV with eyes open group, a visual feedback-deprived plus WBV (VFDWBV) group, and a control group (0 Hz, eyes open). WBV training was provided over a 3-month period, 3 times per week for 5 min each session. Balance performance was measured with the limits of stability test, and muscle strength was measured with an isokinetic dynamometer.A total of 45 elderly subjects with an average age of 69.22  ±  3.97 years, divided into a WBV group (n = 14), a VFDWBV group (n = 17), and a control group (n = 14), completed the trial. Statistically significant differences were found in the balance performance of the 3 groups at different time points (time × group interaction: F = 13.213, P strength of the knee extensor and flexor muscles had time × group interactions: F = 29.604, P muscle strength than the WBV and control groups. The 6-month follow-up showed that the rates of hospital visits for medical services due to falls were 0% in the WBV group (0/14), 0% in the VFDWBV group (0/17), and 28.57% in the control group (4/14).Results showed that WBV training at 20  Hz without visual feedback can significantly improve the balance performance and lower-extremity muscle strength of the elderly.

  5. Comparison of the effects of visual feedback training and unstable surface training on static and dynamic balance in patients with stroke.

    Science.gov (United States)

    Hwang, Hyuck-Soon; Kim, Jin-Hong; Choi, Bo-Ram

    2017-10-01

    [Purpose] This study compared the effects of visual feedback training and unstable surface training on the static and dynamic balance of stroke patients. [Subjects and Methods] The study enrolled 20 stroke patients and randomly assigned them to visual feedback training and unstable surface training groups. Both groups performed 30 minutes of conventional exercise therapy twice a week for 4 weeks. In addition, the subjects in the visual feedback training group completed a visual feedback training regimen and the subjects in the unstable surface training group completed training on an unstable surface (30-minute session three times a week for 4 weeks in both groups). Static and dynamic balance parameters were recorded immediately before and after the 4 weeks of training. For data analysis, the paired and independent t-test was used to compare the two groups. [Results] In the visual feedback training group, the sway line at the postural sway of the center of pressure and trace length decreased significantly after training. In both groups, the sway range at the limits of stability in the anteroposterior and mediolateral directions increased significantly after training. [Conclusion] Visual feedback training was better at improving static and dynamic balance than unstable surface training in stroke patients.

  6. Training Sessional Academic Staff to Provide Quality Feedback on University Students' Assessment: Lessons from a Faculty of Law Learning and Teaching Project

    Science.gov (United States)

    Richards, Kelly; Bell, Tamara; Dwyer, Angela

    2017-01-01

    The quality of feedback provided to university students has long been recognised as the most important predictor of student learning and satisfaction. However, providing quality feedback to students is challenging in the current context, in which universities increasingly rely on casualised and inexperienced academic staff to assess undergraduate…

  7. Utilizing Provider Feedback to Develop Opioid Risk Mitigation Tools for the Military Health System

    Science.gov (United States)

    2017-08-27

    complex environment of care, treating patients who are often mobile and whose prior prescription history may be difficult to access. Clinical Decision...Support (CDS) tools provide healthcare providers with knowledge and detailed information to enhance decision-making in the clinical workflow and

  8. Providing Written Feedback on Students' Mathematical Arguments: Proof Validations of Prospective Secondary Mathematics Teachers

    Science.gov (United States)

    Bleiler, Sarah K.; Thompson, Denisse R.; Krajcevski, Milé

    2014-01-01

    Mathematics teachers play a unique role as experts who provide opportunities for students to engage in the practices of the mathematics community. Proof is a tool essential to the practice of mathematics, and therefore, if teachers are to provide adequate opportunities for students to engage with this tool, they must be able to validate student…

  9. Ambiguity and visual word recognition: can feedback explain both homophone and polysemy effects?

    Science.gov (United States)

    Pexman, P M; Lupker, S J

    1999-12-01

    In a lexical-decision task (LDT), Hino and Lupker (1996) reported a polysemy effect (faster response times for polysemous words [e.g., BANK]), and attributed this effect to enhanced feedback from the semantic system to orthographic units, for polysemous words. Using the same task, Pexman, Lupker, and Jared (in review) reported a homophone effect (slower response times for homophonic words [e.g., MAID]) and attributed this effect to inconsistent feedback from the phonological system to orthographic units, for homophones. In the present paper we test two predictions derived from this feedback explanation: Polysemy and homophone effects should (a) co-occur in a standard LDT (with pseudoword foils) and (b) both be larger with pseudohomophones (e.g., BRANE) as foils in LDT. The results supported both predictions.

  10. Optimizing Video Games for the Hearing Impaired : The Use of Haptic Feedback and Visual Cues in Games

    OpenAIRE

    Mäenpää, Heidi

    2014-01-01

    The purpose of this thesis was to see how games can be optimized for the hearing impaired users without adding greatly to the development costs. The objective was to collect data on the target group’s gaming habits and explore ways haptic feedback and visual cues could be used in games. Based on the findings the aim was to create a sound-based puzzle game and optimize that to the hearing impaired gamers. The initial research data was collected from 28 people in an online survey. The resul...

  11. ENCOURAGING ELECTRICITY SAVINGS IN A UNIVERSITY RESIDENTIAL HALL THROUGH A COMBINATION OF FEEDBACK, VISUAL PROMPTS, AND INCENTIVES

    Science.gov (United States)

    Bekker, Marthinus J; Cumming, Tania D; Osborne, Nikola K.P; Bruining, Angela M; McClean, Julia I; Leland, Louis S

    2010-01-01

    This experiment investigated the combined use of visual prompts, daily feedback, and rewards to reduce electricity consumption in a university residential hall. After a 17-day baseline period, the experimental intervention was introduced in the intervention hall, and no change was made in the control hall. Energy usage decreased in the intervention hall, but energy usage did not change appreciably in the control hall. In the intervention hall, mean daytime and nighttime savings were 16.2% and 10.7%, respectively, compared to savings of 3.8% (day) and 6.5% (night) in the control hall. PMID:21119909

  12. Design Considerations for Smoking Cessation Apps: Feedback From Nicotine Dependence Treatment Providers and Smokers.

    Science.gov (United States)

    McClure, Jennifer B; Hartzler, Andrea L; Catz, Sheryl L

    2016-02-12

    Hundreds of smoking cessation apps are commercially available, but most are not theory-based or designed to take advantage of mobile technology in ways that could make them more engaging and possibly more effective. Considering input from both clinical experts (who understand best practice nicotine dependence treatment requirements) to inform appropriate content and from smokers (the end users) to express their preferences is important in designing these programs in the future. To assess and compare the opinions of nicotine dependence treatment providers and smokers regarding the design of future smoking cessation apps. We surveyed providers (n=264) and smokers who own smartphones (n=40) to assess their opinions on the importance of 21 app design features. Features represented 5 domains: cost, reputation, privacy and security, content and user experience, and communication. Domains were chosen to reflect best practice treatment, leverage mobile technology to support smoking cessation, and elicit important user preferences. Data were collected between June and July 2015. Most providers agreed that mHealth apps hold promise for helping people quit smoking (203/264, 76.9%) and would recommend them to their clients/patients (201/264, 76.1%), especially if the app were empirically validated (236/264, 89.4%). Few providers believe effective cessation apps currently exist (112/264, 42.4%). Few smokers (5/40, 13%) had ever downloaded a smoking cessation app; of the ones who had not, most said they would consider doing so (29/35, 83%). Both respondent groups indicated the following features were very to extremely important to include in cessation apps: free or low cost, keeps information private, matches individual needs and interests, adapts as one's needs and interests change, helps to manage nicotine withdrawal symptoms and medication side effects, and allows users to track their progress. Providers and smokers also indicated gaming and social media connectivity were

  13. V4 receptive field dynamics as predicted by a systems-level model of visual attention using feedback from the frontal eye field.

    Science.gov (United States)

    Hamker, Fred H; Zirnsak, Marc

    2006-11-01

    Visual attention is generally considered to facilitate the processing of the attended stimulus. Its mechanisms, however, are still under debate. We have developed a systems-level model of visual attention which predicts that attentive effects emerge by the interactions between different brain areas. Recent physiological studies have provided evidence that attention also alters the receptive field structure. For example, V4 receptive fields typically shrink and shift towards the saccade target around saccade onset. We show that receptive field dynamics are inherently predicted by the mechanism of feedback in our model. According to the model an oculomotor feedback signal from an area involved in the competition for the saccade target location, e.g. the frontal eye field, enhances the gain of V4 cells. V4 receptive field dynamics can be observed after pooling the gain modulated responses to obtain a certain degree of spatial invariance. The time course of the receptive field dynamics in the model resemble those obtained from macaque V4.

  14. The results of a survey highlighting issues with feedback on medical training in the United Kingdom and how a Smartphone App could provide a solution.

    Science.gov (United States)

    Gray, Thomas G; Hood, Gill; Farrell, Tom

    2015-11-06

    Feedback drives learning in medical education. Healthcare Supervision Logbook (HSL) is a Smartphone App developed at Sheffield Teaching Hospitals for providing feedback on medical training, from both a trainee's and a supervisor's perspective. In order to establish a mandate for the role of HSL in clinical practice, a large survey was carried out. Two surveys (one for doctors undertaking specialty training and a second for consultants supervising their training) were designed. The survey for doctors-in-training was distributed to all specialty trainees in the South and West localities of the Health Education Yorkshire and the Humber UK region. The survey for supervisors was distributed to all consultants involved in educational and clinical supervision of specialty trainees at Sheffield Teaching Hospitals. The results confirm that specialty trainees provide feedback on their training infrequently-66 % do so only annually. 96 % of the specialty trainees owned a Smartphone and 45 % said that they would be willing to use a Smartphone App to provide daily feedback on the clinical and educational supervision they receive. Consultant supervisors do not receive regular feedback on the educational and clinical supervision they provide to trainees-56 % said they never received such feedback and 33 % said it was only on an annual basis. 86 % of consultants surveyed owned a Smartphone and 41 % said they would be willing to use a Smartphone App to provide feedback on the performance of trainees they were supervising. Feedback on medical training is recorded by specialty trainees infrequently and consultants providing educational and clinical supervision often do not receive any feedback on their performance in this area. HSL is a simple, quick and efficient way to collect and collate feedback on medical training to improve this situation. Good support and education needs to be provided when implementing this new technology.

  15. Validity of the Microsoft Kinect for providing lateral trunk lean feedback during gait retraining.

    Science.gov (United States)

    Clark, Ross A; Pua, Yong-Hao; Bryant, Adam L; Hunt, Michael A

    2013-09-01

    Gait retraining programs are prescribed to assist in the rehabilitation process of many clinical conditions. Using lateral trunk lean modification as the model, the aim of this study was to assess the concurrent validity of kinematic data recorded using a marker-based 3D motion analysis (3DMA) system and a low-cost alternative, the Microsoft Kinect™ (Kinect), during a gait retraining session. Twenty healthy adults were trained to modify their gait to obtain a lateral trunk lean angle of 10°. Real-time biofeedback of the lateral trunk lean angle was provided on a computer screen in front of the subject using data extracted from the Kinect skeletal tracking algorithm. Marker coordinate data were concurrently recorded using the 3DMA system, and the similarity and equivalency of the trunk lean angle data from each system were compared. The lateral trunk lean angle data obtained from the Kinect system without any form of calibration resulted in errors of a high (>2°) magnitude (mean error=3.2±2.2°). Performing global and individualized calibration significantly (PKinect can be used to create a real-time biofeedback system for gait retraining. Given that this system is low-cost, portable and does not require any sensors to be attached to the body, it could provide numerous advantages when compared to laboratory-based gait retraining systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Anatomy of hierarchy: feedforward and feedback pathways in macaque visual cortex

    NARCIS (Netherlands)

    Markov, N.T.; Vezoli, J.; Chameau, P.; Falchier, A.; Quilodran, R.; Huissoud, C.; Lamy, C.; Misery, P.; Giroud, P.; Ullman, S.; Barone, P.; Dehay, C.; Knoblauch, K.; Kennedy, H.

    2014-01-01

    The laminar location of the cell bodies and terminals of interareal connections determines the hierarchical structural organization of the cortex and has been intensively studied. However, we still have only a rudimentary understanding of the connectional principles of feedforward (FF) and feedback

  17. Adaptive learning in a compartmental model of visual cortex - how feedback enables stable category learning and refinement

    Directory of Open Access Journals (Sweden)

    Georg eLayher

    2014-12-01

    Full Text Available The categorization of real world objects is often reflected in the similarity of their visual appearances. Such categories of objects do not necessarily form disjunct sets of objects, neither semantically nor visually. The relationship between categories can often be described in terms of a hierarchical structure. For instance, tigers and leopards build two separate mammalian categories, but both belong to the category of felines. In other words, tigers and leopards are subcategories of the category Felidae. In the last decades, the unsupervised learning of categories of visual input stimuli has been addressed by numerous approaches in machine learning as well as in the computational neurosciences. However, the question of what kind of mechanisms might be involved in the process of subcategory learning, or category refinement, remains a topic of active investigation. We propose a recurrent computational network architecture for the unsupervised learning of categorial and subcategorial visual input representations. During learning, the connection strengths of bottom-up weights from input to higher-level category representations are adapted according to the input activity distribution. In a similar manner, top-down weights learn to encode the characteristics of a specific stimulus category. Feedforward and feedback learning in combination realize an associative memory mechanism, enabling the selective top-down propagation of a category's feedback weight distribution. We suggest that the difference between the expected input encoded in the projective field of a category node and the current input pattern controls the amplification of feedforward-driven representations. Large enough differences trigger the recruitment of new representational resources and the establishment of (sub- category representations. We demonstrate the temporal evolution of such learning and show how the approach successully establishes category and subcategory

  18. Novel virtual reality system integrating online self-face viewing and mirror visual feedback for stroke rehabilitation: rationale and feasibility.

    Science.gov (United States)

    Shiri, Shimon; Feintuch, Uri; Lorber-Haddad, Adi; Moreh, Elior; Twito, Dvora; Tuchner-Arieli, Maya; Meiner, Zeev

    2012-01-01

    To introduce the rationale of a novel virtual reality system based on self-face viewing and mirror visual feedback, and to examine its feasibility as a rehabilitation tool for poststroke patients. A novel motion capture virtual reality system integrating online self-face viewing and mirror visual feedback has been developed for stroke rehabilitation.The system allows the replacement of the impaired arm by a virtual arm. Upon making small movements of the paretic arm, patients view themselves virtually performing healthy full-range movements. A sample of 6 patients in the acute poststroke phase received the virtual reality treatment concomitantly with conservative rehabilitation treatment. Feasibility was assessed during 10 sessions for each participant. All participants succeeded in operating the system, demonstrating its feasibility in terms of adherence and improvement in task performance. Patients' performance within the virtual environment and a set of clinical-functional measures recorded before the virtual reality treatment, at 1 week, and after 3 months indicated neurological status and general functioning improvement. These preliminary results indicate that this newly developed virtual reality system is safe and feasible. Future randomized controlled studies are required to assess whether this system has beneficial effects in terms of enhancing upper limb function and quality of life in poststroke patients.

  19. Localized adenosine signaling provides fine-tuned negative feedback over a wide dynamic range of neocortical network activities

    Science.gov (United States)

    Richardson, Magnus J. E.

    2014-01-01

    Although the patterns of activity produced by neocortical networks are now better understood, how these states are activated, sustained, and terminated still remains unclear. Negative feedback by the endogenous neuromodulator adenosine may potentially play an important role, as it can be released by activity and there is dense A1 receptor expression in the neocortex. Using electrophysiology, biosensors, and modeling, we have investigated the properties of adenosine signaling during physiological and pathological network activity in rat neocortical slices. Both low- and high-rate network activities were reduced by A1 receptor activation and enhanced by block of A1 receptors, consistent with activity-dependent adenosine release. Since the A1 receptors were neither saturated nor completely unoccupied during either low- or high-rate activity, adenosine signaling provides a negative-feedback mechanism with a wide dynamic range. Modeling and biosensor experiments show that during high-rate activity increases in extracellular adenosine concentration are highly localized and are uncorrelated over short distances that are certainly adenosine release during low-rate activity, although it is present, is probably a consequence of small localized increases in adenosine concentration that are rapidly diminished by diffusion and active removal mechanisms. Saturation of such removal mechanisms when higher concentrations of adenosine are released results in the accumulation of inosine, explaining the strong purine signal during high-rate activity. PMID:25392170

  20. Bursting thalamic responses in awake monkey contribute to visual detection and are modulated by corticofugal feedback

    Directory of Open Access Journals (Sweden)

    Tania eOrtuno

    2014-05-01

    Full Text Available The lateral geniculate nucleus is the gateway for visual information en route to the visual cortex. Neural activity is characterized by the existence of 2 firing modes: burst and tonic. Originally associated with sleep, bursts have now been postulated to be a part of the normal visual response, structured to increase the probability of cortical activation, able to act as a wake-up call to the cortex. We investigated a potential role for burst in the detection of novel stimuli by recording neuronal activity in the LGN of behaving monkeys during a visual detection task. Our results show that bursts are often the neuron’s first response, and are more numerous in the response to attended target stimuli than to unattended distractor stimuli. Bursts are indicators of the task novelty, as repetition decreased bursting. Because the primary visual cortex is the major modulatory input to the LGN, we compared the results obtained in control conditions with those observed when cortical activity was reduced by TMS. This cortical deactivation reduced visual response related bursting by 90%. These results highlight a novel role for the thalamus, able to code higher order image attributes as important as novelty early in the thalamo-cortical conversation.

  1. Understanding the International Space Station Crew Perspective following Long-Duration Missions through Data Analytics & Visualization of Crew Feedback

    Science.gov (United States)

    Bryant, Cody; Meza, David; Schoenstein, Nicole; Schuh, Susan

    2017-01-01

    The International Space Station (ISS) first became a home and research laboratory for NASA and International Partner crewmembers over 16 years ago. Each ISS mission lasts approximately 6 months and consists of three to six crewmembers. After returning to Earth, most crewmembers participate in an extensive series of 30+ debriefs intended to further understand life onboard ISS and allow crews to reflect on their experiences. Examples of debrief data collected include ISS crew feedback about sleep, dining, payload science, scheduling and time planning, health & safety, and maintenance. The Flight Crew Integration (FCI) Operational Habitability (OpsHab) team, based at Johnson Space Center (JSC), is a small group of Human Factors engineers and one stenographer that has worked collaboratively with the NASA Astronaut office and ISS Program to collect, maintain, disseminate and analyze this data. The database provides an exceptional and unique resource for understanding the "crew perspective" on long duration space missions. Data is formatted and categorized to allow for ease of search, reporting, and ultimately trending, in order to understand lessons learned, recurring issues and efficiencies gained over time. Recently, the FCI OpsHab team began collaborating with the NASA JSC Knowledge Management team to provide analytical analysis and visualization of these over 75,000 crew comments in order to better ascertain the crew's perspective on long duration spaceflight and gain insight on changes over time. In this initial phase of study, a text mining framework was used to cluster similar comments and develop measures of similarity useful for identifying relevant topics affecting crew health or performance, locating similar comments when a particular issue or item of operational interest is identified, and providing search capabilities to identify information pertinent to future spaceflight systems and processes for things like procedure development and training. In addition

  2. The Effectiveness of Verbal Information Provided by Electronic Travel Aids for Visually Impaired Persons

    Science.gov (United States)

    Havik, Else M.; Kooijman, Aart C.; Steyvers, Frank J. J. M.

    2011-01-01

    The effectiveness of different types of verbal information provided by electronic travel aids was studied in a real-life setting. Assessments included wayfinding performance and the preferences of 24 visually impaired users. The participants preferred a combination of route information and environmental information, even though this information…

  3. The Effectiveness of Verbal Information Provided by Electronic Travel Aids for Visually Impaired Persons

    NARCIS (Netherlands)

    Havik, Else M.; Kooijman, Aart C.; Steyvers, Frank J. J. M.

    2011-01-01

    The effectiveness of different types of verbal information provided by electronic travel aids was studied in a real-life setting. Assessments included wayfinding performance and the preferences of 24 visually impaired users. The participants preferred a combination of route information and

  4. Analyzing effects of providing performance feedback at ward rounds on guideline adherence - The importance of feedback usage analysis and statistical control charts

    NARCIS (Netherlands)

    Abu-Hanna, Ameen; Eslami, Saeid; Schultz, Marcus J.; de Jonge, Evert; de Keizer, Nicolette F.

    2010-01-01

    Objective: Feedback to clinicians on their past performance is often aimed at increasing adherence to guidelines. We investigate how various analytical approaches influence the interpretation of adherence data. The analytical approaches vary in considering the actual or the intended use of the

  5. Constructing a survey over time: Audio-visual feedback and theatre sketches in rural Mali

    Directory of Open Access Journals (Sweden)

    Véronique Hertrich

    2011-10-01

    Full Text Available Knowledge dissemination is an emerging issue in population studies, both in terms of ethics and data quality. The challenge is especially important in long term follow-up surveys and it requires methodological imagination when the population is illiterate. The paper presents the dissemination project developed in a demographic surveillance system implemented in rural Mali over the last 20 years. After basic experience of document transfer, the feedback strategy was developed through audiovisual shows and theatre sketches. The advantages and drawbacks of these media are discussed, in terms of scientific communication and the construction of dialogue with the target population.

  6. Effectiveness of a Training Program in Supervisors' Ability to Provide Feedback on Residents' Communication Skills

    Science.gov (United States)

    Junod Perron, Noelle; Nendaz, Mathieu; Louis-Simonet, Martine; Sommer, Johanna; Gut, Anne; Baroffio, Anne; Dolmans, Diana; van der Vleuten, Cees

    2013-01-01

    Teaching communication skills (CS) to residents during clinical practice remains problematic. Direct observation followed by feedback is a powerful way to teach CS in clinical practice. However, little is known about the effect of training on feedback skills in this field. Controlled studies are scarce as well as studies that go beyond…

  7. Mirror Visual Feedback Training Improves Intermanual Transfer in a Sport-Specific Task: A Comparison between Different Skill Levels

    Directory of Open Access Journals (Sweden)

    Fabian Steinberg

    2016-01-01

    Full Text Available Mirror training therapy is a promising tool to initiate neural plasticity and facilitate the recovery process of motor skills after diseases such as stroke or hemiparesis by improving the intermanual transfer of fine motor skills in healthy people as well as in patients. This study evaluated whether these augmented performance improvements by mirror visual feedback (MVF could be used for learning a sport-specific skill and if the effects are modulated by skill level. A sample of 39 young, healthy, and experienced basketball and handball players and 41 novices performed a stationary basketball dribble task at a mirror box in a standing position and received either MVF or direct feedback. After four training days using only the right hand, performance of both hands improved from pre- to posttest measurements. Only the left hand (untrained performance of the experienced participants receiving MVF was more pronounced than for the control group. This indicates that intermanual motor transfer can be improved by MVF in a sport-specific task. However, this effect cannot be generalized to motor learning per se since it is modulated by individuals’ skill level, a factor that might be considered in mirror therapy research.

  8. Concurrent audio-visual feedback for supporting drivers at intersections: A study using two linked driving simulators.

    Science.gov (United States)

    Houtenbos, M; de Winter, J C F; Hale, A R; Wieringa, P A; Hagenzieker, M P

    2017-04-01

    A large portion of road traffic crashes occur at intersections for the reason that drivers lack necessary visual information. This research examined the effects of an audio-visual display that provides real-time sonification and visualization of the speed and direction of another car approaching the crossroads on an intersecting road. The location of red blinking lights (left vs. right on the speedometer) and the lateral input direction of beeps (left vs. right ear in headphones) corresponded to the direction from where the other car approached, and the blink and beep rates were a function of the approaching car's speed. Two driving simulators were linked so that the participant and the experimenter drove in the same virtual world. Participants (N = 25) completed four sessions (two with the audio-visual display on, two with the audio-visual display off), each session consisting of 22 intersections at which the experimenter approached from the left or right and either maintained speed or slowed down. Compared to driving with the display off, the audio-visual display resulted in enhanced traffic efficiency (i.e., greater mean speed, less coasting) while not compromising safety (i.e., the time gap between the two vehicles was equivalent). A post-experiment questionnaire showed that the beeps were regarded as more useful than the lights. It is argued that the audio-visual display is a promising means of supporting drivers until fully automated driving is technically feasible. Copyright © 2016. Published by Elsevier Ltd.

  9. A Manipulation of Visual Feedback during Gait Training in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Quincy J. Almeida

    2012-01-01

    Full Text Available Visual cues are known to improve gait in Parkinson's disease (PD; however, the contribution of optic flow continues to be disputed. This study manipulated transverse line cues during two gait training interventions (6 weeks. PD subjects (N=42 were assigned to one of three groups: treadmill (TG, overground (OG, or control group (CG. Participants walked across lines placed on either treadmills or 16-meter carpets, respectively. The treadmill (TG offered a reduced dynamic flow from the environment, while lines presented on the ground (OG emphasized optic flow related to the participant's own displacement. Both interventions significantly improved (and maintained through retention period step length, thus improving walking velocity. Only the OG improved in the TUG test, while only the TG showed hints of improving (and maintaining motor symptoms. Since gait improvements were found in both training groups, we conclude that by reducing optic flow, gait benefits associated with visual cueing training can still be achieved.

  10. Improving Precision in Navigating Laparoscopic Surgery Instruments toward a Planar Target Using Haptic and Visual Feedback

    OpenAIRE

    Howard, Thomas; Szewczyk, Jérôme

    2016-01-01

    The poor ergonomics of laparoscopic surgery is a widely recognized source of difficulty for surgeons, leading to sub-optimal performance on their part and sometimes injury to the patient. The main recognized causes for such degraded performance are lost and distorted perception of interaction forces and degraded instrument navigation capabilities. The latter, due mainly to losses in visual and kinesthetic depth perception and modified hand-eye coordination, can prevent precise navigation of i...

  11. New approaches to provide feedback from nuclear and covariance data adjustment for effective improvement of evaluated nuclear data files

    Energy Technology Data Exchange (ETDEWEB)

    Palmiotti, Giuseppe; Salvatores, Massimo; Hursin, Mathieu; Kodeli, Ivo; Gabrielli, Fabrizio; Hummel, Andrew

    2016-11-01

    A critical examination of the role of uncertainty assessment, target accuracies, role of integral experiment for validation and, consequently, of data adjustments methods is underway since several years at OECD-NEA, the objective being to provide criteria and practical approaches to use effectively the results of sensitivity analyses and cross section adjustments for feedback to evaluators and experimentalists in order to improve without ambiguities the knowledge of neutron cross sections, uncertainties, and correlations to be used in a wide range of applications and to meet new requirements and constraints for innovative reactor and fuel cycle system design. An approach will be described that expands as much as possible the use in the adjustment procedure of selected integral experiments that provide information on “elementary” phenomena, on separated individual physics effects related to specific isotopes or on specific energy ranges. An application to a large experimental data base has been performed and the results are discussed in the perspective of new evaluation projects like the CIELO initiative.

  12. New approaches to provide feedback from nuclear and covariance data adjustment for effective improvement of evaluated nuclear data files

    Science.gov (United States)

    Palmiotti, Giuseppe; Salvatores, Massimo; Hursin, Mathieu; Kodeli, Ivo; Gabrielli, Fabrizio; Hummel, Andrew

    2017-09-01

    A critical examination of the role of uncertainty assessment, target accuracies, role of integral experiment for validation and, consequently, of data adjustments methods is underway since several years at OECD-NEA, the objective being to provide criteria and practical approaches to use effectively the results of sensitivity analyses and cross section adjustments for feedback to evaluators and experimentalists in order to improve without ambiguities the knowledge of neutron cross sections, uncertainties, and correlations to be used in a wide range of applications and to meet new requirements and constraints for innovative reactor and fuel cycle system design. An approach will be described that expands as much as possible the use in the adjustment procedure of selected integral experiments that provide information on "elementary" phenomena, on separated individual physics effects related to specific isotopes or on specific energy ranges. An application to a large experimental data base has been performed and the results are discussed in the perspective of new evaluation projects like the CIELO initiative.

  13. Effects of the visual-feedback-based force platform training with functional electric stimulation on the balance and prevention of falls in older adults: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Zhen Li

    2018-01-01

    Full Text Available Background Force platform training with functional electric stimulation aimed at improving balance may be effective in fall prevention for older adults. Aim of the study is to evaluate the effects of the visual-feedback-based force platform balance training with functional electric stimulation on balance and fall prevention in older adults. Methods A single-centre, unblinded, randomized controlled trial was conducted. One hundred and twenty older adults were randomly allocated to two groups: the control group (n = 60, one-leg standing balance exercise, 12 min/d or the intervention group (n = 60, force platform training with functional electric stimulation, 12 min/d. The training was provided 15 days a month for 3 months by physical therapists. Medial–lateral and anterior–posterior maximal range of sway with eyes open and closed, the Berg Balance Scale, the Barthel Index, the Falls Efficacy scale-International were assessed at baseline and after the 3-month intervention. A fall diary was kept by each participant during the 6-month follow-up. Results On comparing the two groups, the intervention group showed significantly decreased (p < 0.01 medial–lateral and anterior–posterior maximal range of sway with eyes open and closed. There was significantly higher improvement in the Berg Balance Scale (p < 0.05, the Barthel Index (p < 0.05 and the Falls Efficacy Scale-International (p < 0.05, along with significantly lesser number of injurious fallers (p < 0.05, number of fallers (p < 0.05, and fall rates (p < 0.05 during the 6-month follow-up in the intervention group. Conclusion This study showed that the visual feedback-based force platform training with functional electric stimulation improved balance and prevented falls in older adults.

  14. Using Audience Response Technology to provide formative feedback on pharmacology performance for non-medical prescribing students--a preliminary evaluation.

    Science.gov (United States)

    Mostyn, Alison; Meade, Oonagh; Lymn, Joanne S

    2012-11-13

    . The significant correlation between ART response scores and student exam scores suggests that formative feedback can provide students with a useful reference point in terms of their level of exam-readiness.

  15. Strategies for providing upper extremity amputees with tactile and hand position feedback--moving closer to the bionic arm.

    Science.gov (United States)

    Riso, R R

    1999-01-01

    A continuing challenge for prostheses developers is to replace the sensory function of the hand. This includes tactile sensitivity such as finger contact, grip force, object slippage, surface texture and temperature, as well as proprioceptive sense. One approach is sensory substitution whereby an intact sensory system such as vision, hearing or cutaneous sensation elsewhere on the body is used as an input channel for information related to the prosthesis. A second technique involves using electrical stimulation to deliver sensor derived information directly to the peripheral afferent nerves within the residual limb. Stimulation of the relevant afferent nerves can ultimately come closest to restoring the original sensory perceptions of the hand, and to this end, researchers have already demonstrated some degree of functionality of the transected sensory nerves in studies with amputee subjects. This paper provides an overview of different types of nerve interface components and the advantages and disadvantages of employing each of them in sensory feedback systems. Issues of sensory perception, neurophysiology and anatomy relevant to hand sensation and function are discussed with respect to the selection of the different types of nerve interfaces. The goal of this paper is to outline what can be accomplished for implementing sensation into artificial arms in the near term by applying what is present or presently attainable technology.

  16. Systematic review and meta-analysis of internet-delivered interventions providing personalized feedback for weight loss in overweight and obese adults.

    Science.gov (United States)

    Sherrington, A; Newham, J J; Bell, R; Adamson, A; McColl, E; Araujo-Soares, V

    2016-06-01

    Obesity levels continue to rise annually. Face-to-face weight loss consultations have previously identified mixed effectiveness and face high demand with limited resources. Therefore, alternative interventions, such as internet-delivered interventions, warrant further investigation. The aim was to assess whether internet-delivered weight loss interventions providing personalized feedback were more effective for weight loss in overweight and obese adults in comparison with control groups receiving no personalized feedback. Nine databases were searched, and 12 studies were identified that met all inclusion criteria. Meta-analysis, identified participants receiving personalized feedback via internet-delivered interventions, had 2.13 kg mean difference (SMD) greater weight loss (and BMI change, waist circumference change and 5% weight loss) in comparison with control groups providing no personalized feedback. This was also true for results at 3 and 6-month time points but not for studies where interventions lasted ≥12 months. This suggests that personalized feedback may be an important behaviour change technique (BCT) to incorporate within internet-delivered weight loss interventions. However, meta-analysis results revealed no differences between internet-delivered weight loss interventions with personalized feedback and control interventions ≥12 months. Further investigation into longer term internet-delivered interventions is required to examine how weight loss could be maintained. Future research examining which BCTs are most effective for internet-delivered weight loss interventions is suggested. © 2016 World Obesity.

  17. Research and Teaching: Exploring the Use of an Online Quiz Game to Provide Formative Feedback in a Large-Enrollment, Introductory Biochemistry Course

    Science.gov (United States)

    Milner, Rachel; Parrish, Jonathan; Wright, Adrienne; Gnarpe, Judy; Keenan, Louanne

    2015-01-01

    In a large-enrollment, introductory biochemistry course for nonmajors, the authors provide students with formative feedback through practice questions in PDF format. Recently, they investigated possible benefits of providing the practice questions via an online game (Brainspan). Participants were randomly assigned to either the online game group…

  18. Providing web-based feedback and social norms information to reduce student alcohol intake: a multisite investigation.

    Science.gov (United States)

    Bewick, Bridgette M; West, Robert; Gill, Jan; O'May, Fiona; Mulhern, Brendan; Barkham, Michael; Hill, Andrew J

    2010-12-19

    Unhealthy alcohol use among university students is cause for concern, yet the level of help seeking behavior for alcohol use is low within the student population. Electronic brief interventions delivered via the Internet present an alternative to traditional treatments and could enable the delivery of interventions on a population basis. Further evidence is needed of the effectiveness of Internet-delivered interventions and of their generalizability across educational institutions. Our objective was to evaluate the effectiveness across 4 UK universities of a Web-based intervention for student alcohol use. In total, 1112 participants took part. Participants were stratified by educational institution, gender, age group, year of study, and self-reported weekly consumption of alcohol and randomly assigned to either the control arm or to the immediate or delayed intervention arms. Intervention participants gained access to the intervention between weeks 1 to 7 or weeks 8 to 15, respectively. The intervention provided electronic personalized feedback and social norms information on drinking behavior accessed by logging on to a website. Participants registered interest by completing a brief screening questionnaire and were then asked to complete 4 further assessments across the 24 weeks of the study. Assessments included a retrospective weekly drinking diary, the Alcohol Use Disorders Identification Test (AUDIT), and a readiness-to-change algorithm. The outcome variable was the number of units of alcohol consumed in the last week. The effect of treatment arm and time on units consumed last week and average units consumed per drinking occasion were investigated using repeated measures multivariate analysis of covariance (MANCOVA). In addition, the data were modeled using a longitudinal regression with time points clustered within students. MANCOVA revealed a main effect of time on units of alcohol consumed over the last week. A longitudinal regression model showed an

  19. Visualized Multiprobe Electrical Impedance Measurements with STM Tips Using Shear Force Feedback Control

    Directory of Open Access Journals (Sweden)

    Luis Botaya

    2016-05-01

    Full Text Available Here we devise a multiprobe electrical measurement system based on quartz tuning forks (QTFs and metallic tips capable of having full 3D control over the position of the probes. The system is based on the use of bent tungsten tips that are placed in mechanical contact (glue-free solution with a QTF sensor. Shear forces acting in the probe are measured to control the tip-sample distance in the Z direction. Moreover, the tilting of the tip allows the visualization of the experiment under the optical microscope, allowing the coordination of the probes in X and Y directions. Meanwhile, the metallic tips are connected to a current–voltage amplifier circuit to measure the currents and thus the impedance of the studied samples. We discuss here the different aspects that must be addressed when conducting these multiprobe experiments, such as the amplitude of oscillation, shear force distance control, and wire tilting. Different results obtained in the measurement of calibration samples and microparticles are presented. They demonstrate the feasibility of the system to measure the impedance of the samples with a full 3D control on the position of the nanotips.

  20. Impact of the feedback provided by a gastric electrical stimulation system on eating behavior and physical activity levels.

    Science.gov (United States)

    Busetto, Luca; Torres, Antonio J; Morales-Conde, Salvador; Alarcón Del Agua, Isaias; Moretto, Carlo; Fierabracci, Paola; Rovera, Giuseppe; Segato, Gianni; Rubio, Miguel A; Favretti, Franco

    2017-03-01

    The closed-loop gastric electrical stimulation (CLGES) abiliti(®) system provides tailored gastric electrical stimulation activated by food entry into the stomach and sensor-based data to medical professionals. The aim of this study was to analyze behavior changes using sensor-based food intake and activity data in participants treated with the CLGES system. Food intake and activity data (3D accelerometer) were downloaded at baseline and monthly/bimonthly for 12 months in a subset of patients with obesity (N = 45) participating in a multicenter trial with CLGES. Measured food intake parameters included the number of intakes during allowed and disallowed periods, nighttime intakes, and between-meal snacks (average/d). Activity parameters included time in different levels of physical activity (min/d), sleep/sedentary (h/d), and estimated energy expenditure (EE). Weight loss at 12 months averaged 15.7 ± 7.7% of the baseline body weight. Stable reduction in the number of disallowed meals and between-meal snacks (P < 0.05), an increase in all levels of physical activity (P < 0.001), and an increase in activity-based EE (303 ± 53 kcal/d on average, P < 0.001) were seen. Significant improvement in eating and activity was seen in participants. It is hypothesized that feedback of the sensor-based data induced behavioral changes and contributed to weight loss in patients treated with CLGES. © 2017 The Obesity Society.

  1. Effects of providing personalized feedback of child's obesity risk on mothers' food choices using a virtual reality buffet.

    Science.gov (United States)

    McBride, C M; Persky, S; Wagner, L K; Faith, M S; Ward, D S

    2013-10-01

    Providing personalized genetic-risk feedback of a child's susceptibility to adult-onset health conditions is a topic of considerable debate. Family health history (FHH), specifically parental overweight/obesity status, is a useful assessment for evaluating a child's genetic and environmental risk of becoming obese. It is unclear whether such risk information may influence parents' efforts to reduce their child's risk of obesity. To evaluate whether telling mothers the magnitude of their child's risk of becoming obese based on personal FHH influenced food choices for their young child from a virtual reality-based buffet restaurant. Overweight/obese mothers of a child aged 4-5 years who met eligibility criteria (N=221) were randomly assigned to one of three experimental arms, which emphasized different health information: arm 1, food safety control (Control); arm 2, behavioral-risk information (BRI) alone or arm 3, behavioral-risk information plus personal FHH-based risk assessment (BRI+FHH). Mothers donned a head-mounted display to be immersed in a virtual restaurant buffet, where they selected virtual food and beverages as a lunch for their child. Mothers who were randomized to BRI+FHH filled the index child's plate with an average of 45 fewer calories than those in the Control arm (Pparent). The influence of communicating a child's inherited risk of obesity on mothers' feeding practices may vary by the risk level conveyed. High-risk messages may best be coupled with strategies to increase mother's perceptions that efforts can be undertaken to reduce risk and build requisite behavioral skills to reduce risk.

  2. Providing 360-degree multisource feedback to nurse educators in the country of Georgia: a formative evaluation of acceptability.

    Science.gov (United States)

    DeStephano, Christopher Carl; Crawford, Kimberley Anne; Jashi, Maia; Wold, Judith Lupo

    2014-06-01

    Due to insufficient nursing education standards in the country of Georgia, 15 health professionals participated in a USAID grant-funded nurse educator faculty development program. These educators then offered continuing education courses and taught more than 1,700 practicing Georgian nurses over 3 years. Using a 360-degree multisource feedback model (MSF), self, video, learner, peer, and program coordinator evaluations of teaching effectiveness were completed. After nurse educators reviewed their results and identified areas for improvement, a questionnaire about the perceived acceptability of teacher evaluations was completed. Of the 15 nurse educators, 93.3% indicated that nurse educators should receive feedback through self, learner, peer, and video evaluations, and 100% indicated that nurse educators should receive feedback from the program coordinator. The accuracy and usefulness of the program coordinator evaluation was rated the highest, whereas peer evaluation was rated the lowest. This study revealed that MSF was acceptable to Georgian nurse educators. Copyright 2014, SLACK Incorporated.

  3. Internet-based tools to assess diet and provide feedback in chronic kidney disease stage IV: a pilot study.

    Science.gov (United States)

    Murali, Sameer; Arab, Lenore; Vargas, Roberto; Rastogi, Anjay; Ang, Alfonso; Shetty, Nidhi

    2013-03-01

    Successfully changing patients' dietary behavior is a challenging problem in the management of chronic kidney disease (CKD). We conducted a pilot study to test the feasibility and acceptability of an Internet-based, self-administered, dietary assessment tool equipped with instructional feedback, aimed at facilitating dietary adherence to disease-specific nutritional guidelines among CKD stage IV patients while reducing resource burdens on providers. Focus groups were used to develop a user-friendly dietary reporting format. The report was then calibrated to the dietary guidelines outlined by Kidney Disease Outcomes Quality Initiative (K/DOQI) and incorporated into the assessment tool. Elements of the report were developed based on the "transtheoretical model of behavior change" theory, aimed at facilitating patients to enter the action stage of change. The tool was later deployed in a nephrology care site at an academic medical center, where 12 patients diagnosed with stage IV CKD (late-stage, predialysis) completed a dietary assessment before their provider encounter as well as questionnaires gauging their computer literacy, nutritional education history, nutritional knowledge and awareness, and acceptability of the tool. The report was made available to the provider during the clinical encounter, and both patient and physician perception of the report's utility was assessed after the encounter. Approximately 25% to 30% of the patients were severely noncompliant to the K/DOQI guidelines for each nutrient. Awareness about the role of diet in CKD management was widely variable, ranging from 0% to 58% of the patients over different nutrients. All of the patients successfully completed the Web-based dietary assessment. Eighty-four percent of the patients positively rated the tool on its ability to record the patients' dietary data, 58% noted the tool was always able to satisfactorily estimate portion sizes, and 50% thought the navigation was easy or very easy. Eleven

  4. Providing feedback following Leadership WalkRounds is associated with better patient safety culture, higher employee engagement and lower burnout.

    Science.gov (United States)

    Sexton, J Bryan; Adair, Kathryn C; Leonard, Michael W; Frankel, Terri Christensen; Proulx, Joshua; Watson, Sam R; Magnus, Brooke; Bogan, Brittany; Jamal, Maleek; Schwendimann, Rene; Frankel, Allan S

    2017-10-09

    There is a poorly understood relationship between Leadership WalkRounds (WR) and domains such as safety culture, employee engagement, burnout and work-life balance. This cross-sectional survey study evaluated associations between receiving feedback about actions taken as a result of WR and healthcare worker assessments of patient safety culture, employee engagement, burnout and work-life balance, across 829 work settings. 16 797 of 23 853 administered surveys were returned (70.4%). 5497 (32.7% of total) reported that they had participated in WR, and 4074 (24.3%) reported that they participated in WR with feedback. Work settings reporting more WR with feedback had substantially higher safety culture domain scores (first vs fourth quartile Cohen's d range: 0.34-0.84; % increase range: 15-27) and significantly higher engagement scores for four of its six domains (first vs fourth quartile Cohen's d range: 0.02-0.76; % increase range: 0.48-0.70). This WR study of patient safety and organisational outcomes tested relationships with a comprehensive set of safety culture and engagement metrics in the largest sample of hospitals and respondents to date. Beyond measuring simply whether WRs occur, we examine WR with feedback, as WR being done well. We suggest that when WRs are conducted, acted on, and the results are fed back to those involved, the work setting is a better place to deliver and receive care as assessed across a broad range of metrics, including teamwork, safety, leadership, growth opportunities, participation in decision-making and the emotional exhaustion component of burnout. Whether WR with feedback is a manifestation of better norms, or a cause of these norms, is unknown, but the link is demonstrably potent. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. EMG and kinematic analysis of sensorimotor control for patients after stroke using cyclic voluntary movement with visual feedback

    Directory of Open Access Journals (Sweden)

    Song Rong

    2013-02-01

    Full Text Available Abstract Background Clinical scales are often used to evaluate upper-limb deficits. The objective of this study is to investigate the parameters during voluntary arm tracking at different velocities for evaluating motor control performance after stroke. Methods Eight hemiplegic chronic stroke subjects were recruited to perform voluntary movements of elbow flexion and extension by following sinusoidal trajectories from 30 deg to 90 deg at six velocities in the horizontal plane by completing 3, 6, 8, 12, 15, 18 flexion and extension cycles in 36 seconds in a single trial, and the peak velocities ranged from 15.7 to 94.2 deg/s. The actual elbow angle and the target position were displayed as real-time visual feedback. The angular displacement of the arm and electromyographic (EMG signals of biceps and triceps were captured to evaluate the sensorimotor control of the affected and unaffected side. Results The results showed significant differences in the root mean square error (RMSE, response delay (RD and cocontraction index (CI when the affected and unaffected sides were compared during the arm tracking experiment (P Conclusions The method and parameters have potential for clinical use in quantitatively evaluating the sensorimotor deficiencies for patients after stroke about the accuracy of motion, response delay and cocontraction between muscle pairs.

  6. Positive effect of balance training with visual feedback on standing balance abilities in people with incomplete spinal cord injury.

    Science.gov (United States)

    Sayenko, D G; Alekhina, M I; Masani, K; Vette, A H; Obata, H; Popovic, M R; Nakazawa, K

    2010-12-01

    (1) To evaluate the learning potential and performance improvements during standing balance training with visual feedback (VBT) in individuals with incomplete spinal cord injury (SCI) and (2) to determine whether standing static and dynamic stability during training-irrelevant tasks can be improved after the VBT. National Rehabilitation Center for Persons with Disabilities, Tokorozawa, Japan. Six participants with chronic motor and sensory incomplete SCI who were able to stand for at least 5 min without any form of assistive device performed the VBT, 3 days per week, for a total of 12 sessions. During the training, participants stood on a force platform and were instructed to shift their center of pressure in the indicated directions as represented by a cursor on a monitor. The performance and the rate of learning were monitored throughout the training period. Before and after the program, static and dynamic stability was assessed. All participants showed substantial improvements in the scores, which varied between 236±94 and 130±14% of the initial values for different exercises. The balance performance during training-irrelevant tasks was significantly improved: for example, the area inside the stability zone after the training reached 221±86% of the pre-training values. Postural control can be enhanced in individuals with incomplete SCI using VBT. All participants showed substantial improvements during standing in both game performance and training-irrelevant tasks after the VBT.

  7. Feedback: Breakfast of Champions.

    Science.gov (United States)

    Justman, Jeffrey J.

    Feedback is an important skill that people need to learn in life. Feedback is crucial in a public speaking class to improve speaking skills. Providing and receiving feedback is what champions feed on to be successful, thus feedback is called the "Breakfast of Champions." Feedback builds speakers' confidence. Providing in-depth feedback…

  8. Repeated training with augmentative vibrotactile feedback increases object manipulation performance.

    Directory of Open Access Journals (Sweden)

    Cara E Stepp

    Full Text Available Most users of prosthetic hands must rely on visual feedback alone, which requires visual attention and cognitive resources. Providing haptic feedback of variables relevant to manipulation, such as contact force, may thus improve the usability of prosthetic hands for tasks of daily living. Vibrotactile stimulation was explored as a feedback modality in ten unimpaired participants across eight sessions in a two-week period. Participants used their right index finger to perform a virtual object manipulation task with both visual and augmentative vibrotactile feedback related to force. Through repeated training, participants were able to learn to use the vibrotactile feedback to significantly improve object manipulation. Removal of vibrotactile feedback in session 8 significantly reduced task performance. These results suggest that vibrotactile feedback paired with training may enhance the manipulation ability of prosthetic hand users without the need for more invasive strategies.

  9. Contralateral delay activity provides a neural measure of the number of representations in visual working memory.

    Science.gov (United States)

    Ikkai, Akiko; McCollough, Andrew W; Vogel, Edward K

    2010-04-01

    Visual working memory (VWM) helps to temporarily represent information from the visual environment and is severely limited in capacity. Recent work has linked various forms of neural activity to the ongoing representations in VWM. One piece of evidence comes from human event-related potential studies, which find a sustained contralateral negativity during the retention period of VWM tasks. This contralateral delay activity (CDA) has previously been shown to increase in amplitude as the number of memory items increases, up to the individual's working memory capacity limit. However, significant alternative hypotheses remain regarding the true nature of this activity. Here we test whether the CDA is modulated by the perceptual requirements of the memory items as well as whether it is determined by the number of locations that are being attended within the display. Our results provide evidence against these two alternative accounts and instead strongly support the interpretation that this activity reflects the current number of objects that are being represented in VWM.

  10. Investigating the Practice of Providing Written Corrective Feedback Types by ESL Teachers at the Upper Secondary Level in High Performance Schools

    Science.gov (United States)

    Mahmud, Norasyikin

    2016-01-01

    The past few decades has seen the rapid development of WCF (written corrective feedback) study. The present study examined the practice of providing WCF by teachers. The aim of this study was to determine the types of WCF used by English teachers. The study is an explanatory sequential mixed-methods design using open-ended and close-ended survey…

  11. Providing time-discrete gait information by wearable feedback apparatus for lower-limb amputees: usability and functional validation.

    Science.gov (United States)

    Crea, Simona; Cipriani, Christian; Donati, Marco; Carrozza, Maria Chiara; Vitiello, Nicola

    2015-03-01

    Here we describe a novel wearable feedback apparatus for lower-limb amputees. The system is based on three modules: a pressure-sensitive insole for the measurement of the plantar pressure distribution under the prosthetic foot during gait, a computing unit for data processing and gait segmentation, and a set of vibrating elements placed on the thigh skin. The feedback strategy relies on the detection of specific gait-phase transitions of the amputated leg. Vibrating elements are activated in a time-discrete manner, simultaneously with the occurrence of the detected gait-phase transitions. Usability and effectiveness of the apparatus were successfully assessed through an experimental validation involving ten healthy volunteers.

  12. Feed-forward and visual feedback control of head roll orientation in wasps (Polistes humilis, Vespidae, Hymenoptera).

    Science.gov (United States)

    Viollet, Stéphane; Zeil, Jochen

    2013-04-01

    Flying insects keep their visual system horizontally aligned, suggesting that gaze stabilization is a crucial first step in flight control. Unlike flies, hymenopteran insects such as bees and wasps do not have halteres that provide fast, feed-forward angular rate information to stabilize head orientation in the presence of body rotations. We tested whether hymenopteran insects use inertial (mechanosensory) information to control head orientation from other sources, such as the wings, by applying periodic roll perturbations to male Polistes humilis wasps flying in tether under different visual conditions indoors and in natural outdoor conditions. We oscillated the thorax of the insects with frequency-modulated sinusoids (chirps) with frequencies increasing from 0.2 to 2 Hz at a maximal amplitude of 50 deg peak-to-peak and maximal angular velocity of ±245 deg s(-1). We found that head roll stabilization is best outdoors, but completely absent in uniform visual conditions and in darkness. Step responses confirm that compensatory head roll movements are purely visually driven. Modelling step responses indicates that head roll stabilization is achieved by merging information on head angular velocity, presumably provided by motion-sensitive neurons and information on head orientation, presumably provided by light level integration across the compound eyes and/or ocelli (dorsal light response). Body roll in free flight reaches amplitudes of ±40 deg and angular velocities greater than 1000 deg s(-1), while head orientation remains horizontal for most of the time to within ±10 deg. In free flight, we did not find a delay between spontaneous body roll and compensatory head movements, and suggest that this is evidence for the contribution of a feed-forward control to head stabilization.

  13. Trunk stabilization during sagittal pelvic tilt: from trunk-on-pelvis to trunk-in-space due to vestibular and visual feedback.

    Science.gov (United States)

    van Drunen, Paul; van der Helm, Frans C T; van Dieën, Jaap H; Happee, Riender

    2016-03-01

    The goal of this study was to investigate the human ability to stabilize the trunk in space during pelvic tilt. Upper body sway was evoked in kneeling-seated healthy subjects by angular platform perturbations with a rotation around a virtual low-back pivot point between the L4 and L5 vertebrae. To investigate motor control modulation, variations in task instruction (balance naturally or minimize trunk sway), vision (eyes open or closed), and perturbation bandwidth (from 0.2 up to 1, 3, or 10 Hz) were applied. Cocontraction and proprioceptive muscle spindle feedback were associated with minimizing low-back flexion/extension (trunk-on-pelvis stabilization), while vestibular and visual feedback were supposed to contribute to trunk-in-space stabilization. Trunk-in-space stabilization was only observed with the minimize trunk sway task instruction, while the task instruction to balance naturally led to trunk-on-pelvis stabilization with trunk rotations even exceeding the perturbations. This indicates that vestibular feedback is used when minimizing trunk sway but has only a minor contribution during natural trunk stabilization in the sagittal plane. The eyes open condition resulted in reduced global trunk rotations and increased global trunk reflexive responses, demonstrating effective visual contributions to trunk-in-space stabilization. On the other hand, increasing perturbation bandwidth caused a decreased feedback contribution leading to deteriorated trunk-in-space stabilization. Copyright © 2016 the American Physiological Society.

  14. Hand rim wheelchair propulsion training using biomechanical real-time visual feedback based on motor learning theory principles.

    Science.gov (United States)

    Rice, Ian; Gagnon, Dany; Gallagher, Jere; Boninger, Michael

    2010-01-01

    As considerable progress has been made in laboratory-based assessment of manual wheelchair propulsion biomechanics, the necessity to translate this knowledge into new clinical tools and treatment programs becomes imperative. The objective of this study was to describe the development of a manual wheelchair propulsion training program aimed to promote the development of an efficient propulsion technique among long-term manual wheelchair users. Motor learning theory principles were applied to the design of biomechanical feedback-based learning software, which allows for random discontinuous real-time visual presentation of key spatiotemporal and kinetic parameters. This software was used to train a long-term wheelchair user on a dynamometer during 3 low-intensity wheelchair propulsion training sessions over a 3-week period. Biomechanical measures were recorded with a SmartWheel during over ground propulsion on a 50-m level tile surface at baseline and 3 months after baseline. Training software was refined and administered to a participant who was able to improve his propulsion technique by increasing contact angle while simultaneously reducing stroke cadence, mean resultant force, peak and mean moment out of plane, and peak rate of rise of force applied to the pushrim after training. The proposed propulsion training protocol may lead to favorable changes in manual wheelchair propulsion technique. These changes could limit or prevent upper limb injuries among manual wheelchair users. In addition, many of the motor learning theory-based techniques examined in this study could be applied to training individuals in various stages of rehabilitation to optimize propulsion early on.

  15. Promoting smoke-free homes: a novel behavioral intervention using real-time audio-visual feedback on airborne particle levels.

    Directory of Open Access Journals (Sweden)

    Neil E Klepeis

    Full Text Available Interventions are needed to protect the health of children who live with smokers. We pilot-tested a real-time intervention for promoting behavior change in homes that reduces second hand tobacco smoke (SHS levels. The intervention uses a monitor and feedback system to provide immediate auditory and visual signals triggered at defined thresholds of fine particle concentration. Dynamic graphs of real-time particle levels are also shown on a computer screen. We experimentally evaluated the system, field-tested it in homes with smokers, and conducted focus groups to obtain general opinions. Laboratory tests of the monitor demonstrated SHS sensitivity, stability, precision equivalent to at least 1 µg/m(3, and low noise. A linear relationship (R(2 = 0.98 was observed between the monitor and average SHS mass concentrations up to 150 µg/m(3. Focus groups and interviews with intervention participants showed in-home use to be acceptable and feasible. The intervention was evaluated in 3 homes with combined baseline and intervention periods lasting 9 to 15 full days. Two families modified their behavior by opening windows or doors, smoking outdoors, or smoking less. We observed evidence of lower SHS levels in these homes. The remaining household voiced reluctance to changing their smoking activity and did not exhibit lower SHS levels in main smoking areas or clear behavior change; however, family members expressed receptivity to smoking outdoors. This study established the feasibility of the real-time intervention, laying the groundwork for controlled trials with larger sample sizes. Visual and auditory cues may prompt family members to take immediate action to reduce SHS levels. Dynamic graphs of SHS levels may help families make decisions about specific mitigation approaches.

  16. 3D augmented reality mirror visual feedback therapy applied to the treatment of persistent, unilateral upper extremity neuropathic pain: a preliminary study.

    Science.gov (United States)

    Mouraux, Dominique; Brassinne, Eric; Sobczak, Stéphane; Nonclercq, Antoine; Warzée, Nadine; Sizer, Phillip S; Tuna, Turgay; Penelle, Benoît

    2017-07-01

    Objective: We assessed whether or not pain relief could be achieved with a new system that combines 3D augmented reality system (3DARS) and the principles of mirror visual feedback. Methods: Twenty-two patients between 18 and 75 years of age who suffered of chronic neuropathic pain. Each patient performed five 3DARS sessions treatment of 20 mins spread over a period of one week. The following pain parameters were assessed: (1) visual analogic scale after each treatment session (2) McGill pain scale and DN4 questionnaire were completed before the first session and 24 h after the last session. Results: The mean improvement of VAS per session was 29% (p < 0.001). There was an immediate session effect demonstrating a systematic improvement in pain between the beginning and the end of each session. We noted that this pain reduction was partially preserved until the next session. If we compare the pain level at baseline and 24 h after the last session, there was a significant decrease (p < 0.001) of pain of 37%. There was a significant decrease (p < 0.001) on the McGill Pain Questionnaire and DN4 questionnaire (p < 0.01). Conclusion: Our results indicate that 3DARS induced a significant pain decrease for patients who presented chronic neuropathic pain in a unilateral upper extremity. While further research is necessary before definitive conclusions can be drawn, clinicians could implement the approach as a preparatory adjunct for providing temporary pain relief aimed at enhancing chronic pain patients' tolerance of manual therapy and exercise intervention. Level of Evidence: 4.

  17. Visual interfaces as an approach for providing mobile services and mobile content to low literate users in South Africa

    CSIR Research Space (South Africa)

    Matyila, M

    2014-05-01

    Full Text Available in the related mobile applications. Exploring typical challenges experienced by low literate users and adapting these mobile applications using visual interfaces can provide low literate users with usable access to mobile services and mobile content....

  18. Simulatedin vivoElectrophysiology Experiments Provide Previously Inaccessible Insights into Visual Physiology.

    Science.gov (United States)

    Quiroga, Maria; Price, Nicholas SC

    2016-01-01

    Lecture content and practical laboratory classes are ideally complementary. However, the types of experiments that have led to our detailed understanding of sensory neuroscience are often not amenable to classroom experimentation as they require expensive equipment, time-consuming surgeries, specialized experimental techniques, and the use of animals. While sometimes feasible in small group teaching, these experiments are not suitable for large cohorts of students. Previous attempts to expose students to sensory neuroscience experiments include: the use of electrophysiology preparations in invertebrates, data-driven simulations that do not replicate the experience of conducting an experiment, or simply observing an experiment in a research laboratory. We developed an online simulation of a visual neuroscience experiment in which extracellular recordings are made from a motion sensitive neuron. Students have control over stimulation parameters (direction and contrast) and can see and hear the action potential responses to stimuli as they are presented. The simulation provides an intuitive way for students to gain insight into neurophysiology, including experimental design, data collection and data analysis. Our simulation allows large cohorts of students to cost-effectively "experience" the results of animal research without ethical concerns, to be exposed to realistic data variability, and to develop their understanding of how sensory neuroscience experiments are conducted.

  19. Online visual feedback during error-free channel trials leads to active unlearning of movement dynamics: evidence for adaptation to trajectory prediction errors.

    Directory of Open Access Journals (Sweden)

    Angel Lago-Rodriguez

    2016-09-01

    Full Text Available Prolonged exposure to movement perturbations leads to creation of motor memories which decay towards previous states when the perturbations are removed. However, it remains unclear whether this decay is due only to a spontaneous and passive recovery of the previous state. It has recently been reported that activation of reinforcement-based learning mechanisms delays the onset of the decay. This raises the question whether other motor learning mechanisms may also contribute to the retention and/or decay of the motor memory. Therefore, we aimed to test whether mechanisms of error-based motor adaptation are active during the decay of the motor memory. Forty-five right-handed participants performed point-to-point reaching movements under an external dynamic perturbation. We measured the expression of the motor memory through error-clamped (EC trials, in which lateral forces constrained movements to a straight line towards the target. We found greater and faster decay of the motor memory for participants who had access to full online visual feedback during these EC trials (Cursor group, when compared with participants who had no EC feedback regarding movement trajectory (Arc group. Importantly, we did not find between-group differences in adaptation to the external perturbation. In addition, we found greater decay of the motor memory when we artificially increased feedback errors through the manipulation of visual feedback (Augmented-Error group. Our results then support the notion of an active decay of the motor memory, suggesting that adaptive mechanisms are involved in correcting for the mismatch between predicted movement trajectories and actual sensory feedback, which leads to greater and faster decay of the motor memory.

  20. Web-based instrument to assess skills in visual inspection of the cervix among healthcare providers.

    Science.gov (United States)

    Negulescu, Raluca-Anca; Catarino, Rosa; De Vuyst, Hugo; Undurraga-Malinverno, Manuela; Meyer-Hamme, Ulrike; Alec, Milena; Campana, Aldo; Vassilakos, Pierre; Petignat, Patrick

    2016-07-01

    To validate a web-based instrument for assessing healthcare providers' skills in visual inspection with acetic acid or Lugol iodine (VIA/VILI) for the diagnosis and management of cervical intraepithelial neoplasia. An observational cross-sectional study enrolled healthcare providers in a web-based assessment of VIA/VILI skills between August and November 2014. Participants participated in a four-module training course, followed by a multiple-choice test with 70 questions based on cervical photographs of HPV-positive women participating in cervical screening. Logistic regression was used to identify relationships between independent variables and success on the test. Overall, 255 participants completed the test and 99 (38.8%) passed. No correlation was found between age or sex and test performance. Compared with other healthcare workers, physicians (odds ratio [OR] 1.91, 95% confidence interval [CI] 1.01-3.63; P=0.048), and participants with more colposcopy experience (OR 3.62, 95% CI 1.91-6.85; P<0.001) and postgraduate VIA/VILI training (OR 1.95, 95% CI 1.16-3.29; P=0.012) were more likely to pass the test. Participants who repeated the test (31/255 [12.2%]) were five times more likely to succeed on their second repeat (OR 5.89, 95% CI 1.46-23.73; P=0.013). Web-based training for VIA/VILI is feasible and can identify healthcare workers who are proficient in this technique. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Feasibility of visual instrumented movement feedback therapy in individuals with motor incomplete spinal cord injury walking on a treadmill

    Directory of Open Access Journals (Sweden)

    Daniel eSchließmann

    2014-06-01

    Full Text Available Background: Incomplete spinal cord injury (iSCI leads to motor and sensory deficits. Even in ambulatory persons with good motor function an impaired proprioception may result in an insecure gait. Limited internal afferent feedback (FB can be compensated by provision of external FB by therapists or technical systems. Progress in computational power of motion analysis systems allows for implementation of instrumented real-time FB. The aim of this study was to test if individuals with iSCI can normalize their gait kinematics during FB and more importantly maintain an improvement after therapy. Methods: Individuals with chronic iSCI had to complete 6 days (one day per week of treadmill-based FB training with a 2 weeks pause after 3 days of training. Each day consists of an initial gait analysis followed by 2 blocks with FB/no-FB. During FB the deviation of the mean knee angle during swing from a speed matched reference (norm distance, ND is visualized as a number. The task consists of lowering the ND, which was updated after every stride. Prior to the tests in patients the in-house developed FB implementation was tested in healthy subjects with an artificial movement task. Results: 4 of 5 study participants benefited from FB in the short and medium term. Decrease of mean ND was highest during the first 3 sessions (from 3.93±1.54 to 2.18±1.04. After the pause mean ND stayed in the same range than before. In the last 3 sessions the mean ND decreased slower (2.40±1.18 to 2.20±0.90. Direct influences of FB ranged from 60% to 15% of reduction in mean ND compared to initial gait analysis and from 20% to 1% compared to no-FB sessions. Conclusions: Instrumented kinematic real-time FB may serve as an effective adjunct to established gait therapies in normalizing the gait pattern after incomplete spinal cord injury. Further studies with larger patient groups need to prove long term learning and the successful transfer of newly acquired skills to

  2. The Role of Audio-Visual Feedback in a Thought-Based Control of a Humanoid Robot: A BCI Study in Healthy and Spinal Cord Injured People.

    Science.gov (United States)

    Tidoni, Emmanuele; Gergondet, Pierre; Fusco, Gabriele; Kheddar, Abderrahmane; Aglioti, Salvatore M

    2017-06-01

    The efficient control of our body and successful interaction with the environment are possible through the integration of multisensory information. Brain-computer interface (BCI) may allow people with sensorimotor disorders to actively interact in the world. In this study, visual information was paired with auditory feedback to improve the BCI control of a humanoid surrogate. Healthy and spinal cord injured (SCI) people were asked to embody a humanoid robot and complete a pick-and-place task by means of a visual evoked potentials BCI system. Participants observed the remote environment from the robot's perspective through a head mounted display. Human-footsteps and computer-beep sounds were used as synchronous/asynchronous auditory feedback. Healthy participants achieved better placing accuracy when listening to human footstep sounds relative to a computer-generated sound. SCI people demonstrated more difficulty in steering the robot during asynchronous auditory feedback conditions. Importantly, subjective reports highlighted that the BCI mask overlaying the display did not limit the observation of the scenario and the feeling of being in control of the robot. Overall, the data seem to suggest that sensorimotor-related information may improve the control of external devices. Further studies are required to understand how the contribution of residual sensory channels could improve the reliability of BCI systems.

  3. Evaluation of multimodal feedback effects on improving rowing competencies

    Directory of Open Access Journals (Sweden)

    Korman Maria

    2011-12-01

    Full Text Available This study focused on the selection and preliminary evaluation of different types of modal and information feedback in virtual environment to facilitate acquisition and transfer of a complex motor-cognitive skill of rowing. Specifically, we addressed the effectiveness of immediate information feedback provided visually as compared to sensory haptic feedback on the improvement in hands kinematics and changes in cognitive load during the course of learning the basic rowing technique. Several pilot experiments described in this report lead to the evaluation and optimization of the training protocol, to enhance facilitatory effects of adding visual and haptic feedback during training.

  4. Combining the formative with the summative: the development of a two-stage online test to encourage engagement and provide personal feedback in large classes

    Directory of Open Access Journals (Sweden)

    Susanne Voelkel

    2013-04-01

    Full Text Available The aim of this action research project was to improve student learning by encouraging more “time on task” and to improve self-assessment and feedback through the introduction of weekly online tests in a Year 2 lecture module in biological sciences. Initially voluntary online tests were offered to students and those who participated achieved higher exam marks than those who did not, but completion rate was low. Making the tests compulsory led to high completion rates, but class performance decreased, indicating that using the same assessment for formative and for summative purposes is not always beneficial for learning. Finally, these problems were resolved by introducing a two-stage approach: the first stage of each test was formative and provided prompt feedback. However, students had to achieve 80% to progress to the second summative stage of the test. The two-stage online tests led to significantly improved class performance. This novel test design ensures that students go through at least two attempts and therefore fully benefit from the learning opportunities presented by the formative stage. Two-stage online tests present the opportunity to provide regular feedback in large classes and to improve performance not only of good but also of “weak” students.

  5. How to improve prescription of inhaled salbutamol by providing standardised feedback on administration: a controlled intervention pilot study with follow-up.

    Science.gov (United States)

    Neininger, Martina P; Kaune, Almuth; Bertsche, Astrid; Rink, Jessica; Musiol, Juliane; Frontini, Roberto; Prenzel, Freerk; Kiess, Wieland; Bertsche, Thilo

    2015-01-28

    The effectiveness of inhaled salbutamol in routine care depends particularly on prescribed dosage and applied inhalation technique. To achieve maximum effectiveness and to prevent drug-related problems, prescription and administration need to work in concert. We performed a controlled intervention pilot study with 4 consecutive groups in a general paediatric unit and assessed problems in salbutamol prescribing and administration. Control group [i]: Routine care without additional support. First intervention group [ii]: We carried out a teaching session for nurses aimed at preventing problems in inhalation technique. Independently from this, a pharmacist counselled physicians on problems in salbutamol prescribing. Second intervention group [iii]: Additionally to the first intervention, physicians received standardised feedback on the inhalation technique. Follow-up group [iv]: Subsequently, without any delay after the second intervention group had been completed, sustainability of the measures was assessed. We performed the chi-square test to calculate the level of significance with p ≤ 0.05 to indicate a statistically significant difference for the primary outcome. As we performed multiple testing, an adjusted p ≤ 0.01 according to Bonferroni correction was considered as significant. We included a total of 225 patients. By counselling the physicians, we reduced the number of patients with problems from 55% to 43% (control [i] vs. first intervention [ii], n.s.). With additional feedback to physicians, this number was further reduced to 25% ([i] vs. [iii], p < 0.001). In the follow-up [iv], the number rose again to 48% (p < 0.01 compared to feedback group). Teaching nurses, counselling physicians, and providing feedback on the quality of inhalation technique effectively reduced problems in salbutamol treatment. However, for success to be sustained, continuous support needs to be provided. German Clinical Trials register: DRKS00006792 .

  6. Models Provide Specificity: Testing a Proposed Mechanism of Visual Working Memory Capacity Development

    Science.gov (United States)

    Simmering, Vanessa R.; Patterson, Rebecca

    2012-01-01

    Numerous studies have established that visual working memory has a limited capacity that increases during childhood. However, debate continues over the source of capacity limits and its developmental increase. Simmering (2008) adapted a computational model of spatial cognitive development, the Dynamic Field Theory, to explain not only the source…

  7. The effect of virtual visual feedback on supernumerary phantom limb pain in a patient with high cervical cord injury: a single-case design study.

    Science.gov (United States)

    Katayama, Osamu; Iki, Hidemasa; Sawa, Shunji; Osumi, Michihiro; Morioka, Shu

    2015-01-01

    We characterized the effect of virtual visual feedback (VVF) on supernumerary phantom limb pain (SPLP) in a patient with high cervical cord injury. The subject was a 22-year-old man diagnosed with complete spinal cord injury (level C2) approximately 5 years ago. We applied the ABA'B' single-case design and set phases B and B' as intervention phases for comparison. SPLP significantly improved in comparison of phase A with phase B and phase A with phase B'. We suggest that VVF reduces SPLP and the effect lasts after VVF.

  8. D Web Visualization of Environmental Information - Integration of Heterogeneous Data Sources when Providing Navigation and Interaction

    Science.gov (United States)

    Herman, L.; Řezník, T.

    2015-08-01

    3D information is essential for a number of applications used daily in various domains such as crisis management, energy management, urban planning, and cultural heritage, as well as pollution and noise mapping, etc. This paper is devoted to the issue of 3D modelling from the levels of buildings to cities. The theoretical sections comprise an analysis of cartographic principles for the 3D visualization of spatial data as well as a review of technologies and data formats used in the visualization of 3D models. Emphasis was placed on the verification of available web technologies; for example, X3DOM library was chosen for the implementation of a proof-of-concept web application. The created web application displays a 3D model of the city district of Nový Lískovec in Brno, the Czech Republic. The developed 3D visualization shows a terrain model, 3D buildings, noise pollution, and other related information. Attention was paid to the areas important for handling heterogeneous input data, the design of interactive functionality, and navigation assistants. The advantages, limitations, and future development of the proposed concept are discussed in the conclusions.

  9. Development and implementation of an objective structured clinical examination to provide formative feedback on communication and interpersonal skills in geriatric training.

    Science.gov (United States)

    O'Sullivan, Patricia; Chao, Serena; Russell, Matthew; Levine, Sharon; Fabiny, Anne

    2008-09-01

    Teaching and assessment of communication and interpersonal skills, one of the American Council for Graduate Medical Education-designated core competencies, is an important but difficult task in the training of physicians. Assessment of trainees offers an opportunity to provide explicit feedback on their skills and encourages learning. This article describes a pilot study in which clinician-educators affiliated with the geriatrics training programs at Beth Israel Deaconess Medical Center and Boston University Medical Center designed and piloted a novel Objective Structured Clinical Examination (OSCE) to assess the communication and interpersonal skills of medical, dental, and geriatric psychiatry fellows. The OSCE consisted of three stations where geriatricians and standardized patients evaluated candidates using specifically designed checklists and an abbreviated version of the Master Interview Rating Scale. Communication skills were assessed through performance of specific "real life" clinical tasks, such as obtaining a medical history, explaining a diagnosis and prognosis, giving therapeutic instructions, and counseling. Interpersonal skills were assessed through the effect of the communication between doctor and standardized patient on fostering trust, relieving anxiety, and establishing a therapeutic relationship. This pilot study demonstrated that the OSCE format of assessment provides a valid means of evaluating the communication and interpersonal skills of interdisciplinary geriatric trainees and provides a valuable forum for formative assessment and feedback. Given that geriatricians and non geriatricians involved in elder care both need communication and interpersonal skills, this novel OSCE can be used for assessment of these skills in trainees in diverse healthcare subspecialties.

  10. Follower-Centered Perspective on Feedback: Effects of Feedback Seeking on Identification and Feedback Environment

    OpenAIRE

    Gong, Zhenxing; Li, Miaomiao; Qi, Yaoyuan; Zhang, Na

    2017-01-01

    In the formation mechanism of the feedback environment, the existing research pays attention to external feedback sources and regards individuals as objects passively accepting feedback. Thus, the external source fails to realize the individuals’ need for feedback, and the feedback environment cannot provide them with useful information, leading to a feedback vacuum. The aim of this study is to examine the effect of feedback-seeking by different strategies on the supervisor-feedback environme...

  11. Supporting Early Childhood Educators' Use of Embedded Communication Strategies by Providing Feedback via Bug-in-Ear Technology

    Science.gov (United States)

    Riggie, Jennifer

    2013-01-01

    The purpose of this study was to examine the relationship between coaching provided with bug-in-ear technology, the frequency of the early childhood educators' use of targeted communication strategies and children's expressive communication. Four multiple-baseline single-case design experiments were completed to evaluate these relationships.…

  12. Providing Feedback, Orientation and Opportunities for Reflection as Key Elements for Successful Mentoring Programs: Reviewing a Program for Future Business Education Teachers

    Directory of Open Access Journals (Sweden)

    Elisabeth Riebenbauer

    2017-12-01

    Full Text Available The introduction to teaching is critical for novice teachers. Near the end of their master’s program, students of Business Education and Development in Austria spend one semester at an assigned school. They are introduced to teaching, while being assisted by peer students, mentoring teachers, and a companion course. Mentors receive special training and preparation in advance, thus contributing to a high quality mentoring program. The program is organized threefold: (1 providing feedback, (2 opportunities for reflection and (3 career orientation. The purpose of this paper is to assess key elements of successful mentoring programs and to question which competences of mentors contribute most to the success of those programs. Between 2012 and 2015, 188 persons (student teachers and their mentors responded to an online survey at the end of their mentoring program. Additionally, data from a study (1,245 questionnaires regarding the student teachers’ perception of their own competence was utilized, allowing for a comparison of student teacher confidence in their abilities before and after the mentoring program. The present results provide insight into the key elements of successful mentoring programs; both from a student teacher’s and mentor’s perspective. During the semester, students showed an increase regarding their self-perception of their professional competences. It was found that students and mentoring teachers valued feedback after each lesson more than feedback in regular meetings. Opportunities for reflection (e.g. exchange with peer students, learning diaries were considered helpful. The mentoring program helped students to decide whether to become a teacher or not.

  13. Disposable platform provides visual and color-based point-of-care anemia self-testing.

    Science.gov (United States)

    Tyburski, Erika A; Gillespie, Scott E; Stoy, William A; Mannino, Robert G; Weiss, Alexander J; Siu, Alexa F; Bulloch, Rayford H; Thota, Karthik; Cardenas, Anyela; Session, Wilena; Khoury, Hanna J; O'Connor, Siobhán; Bunting, Silvia T; Boudreaux, Jeanne; Forest, Craig R; Gaddh, Manila; Leong, Traci; Lyon, L Andrew; Lam, Wilbur A

    2014-10-01

    Anemia, or low blood hemoglobin (Hgb) levels, afflicts 2 billion people worldwide. Currently, Hgb levels are typically measured from blood samples using hematology analyzers, which are housed in hospitals, clinics, or commercial laboratories and require skilled technicians to operate. A reliable, inexpensive point-of-care (POC) Hgb test would enable cost-effective anemia screening and chronically anemic patients to self-monitor their disease. We present a rapid, stand-alone, and disposable POC anemia test that, via a single drop of blood, outputs color-based visual results that correlate with Hgb levels. We tested blood from 238 pediatric and adult patients with anemia of varying degrees and etiologies and compared hematology analyzer Hgb levels with POC Hgb levels, which were estimated via visual interpretation using a color scale and an optional smartphone app for automated analysis. POC Hgb levels correlated with hematology analyzer Hgb levels (r = 0.864 and r = 0.856 for visual interpretation and smartphone app, respectively), and both POC test methods yielded comparable sensitivity and specificity for detecting any anemia (n = 178) (<11 g/dl) (sensitivity: 90.2% and 91.1%, specificity: 83.7% and 79.2%, respectively) and severe anemia (n = 10) (<7 g/dl) (sensitivity: 90.0% and 100%, specificity: 94.6% and 93.9%, respectively). These results demonstrate the feasibility of this POC color-based diagnostic test for self-screening/self-monitoring of anemia. Not applicable. This work was funded by the FDA-funded Atlantic Pediatric Device Consortium, the Georgia Research Alliance, Children's Healthcare of Atlanta, the Georgia Center of Innovation for Manufacturing, and the InVenture Prize and Ideas to Serve competitions at the Georgia Institute of Technology.

  14. Postural effects of the scaled display of visual foot center of pressure feedback under different somatosensory conditions at the foot and the ankle.

    Science.gov (United States)

    Vuillerme, Nicolas; Bertrand, Romain; Pinsault, Nicolas

    2008-10-01

    To assess the effects of the scaled display of visual foot center of pressure (COP) feedback on upright postural control under different somatosensory conditions at the foot and the ankle. Before and after intervention trials. University medical bioengineering laboratory. Young healthy adults (N=8; mean age, 23+/-2.5 y; mean body weight, 76.8+/-11.2 kg; mean height, 179.8+/-6.8 cm). Participants were asked to stand upright, as immobile as possible, in 3 visual conditions: a stationary cross feedback (SC-FB) condition and 2 different foot COP feedback (COP-FB) conditions involving increasing scale displays of 2:1 (COP-FB2) and of 10:1 (COP-FB10). These latter conditions correspond to the ratio between the COP displacement on the screen and the actual COP displacement measured by the force platform. This postural task was executed on 2 (firm, foam) support surface conditions. In the foam condition, a 2-cm thick foam support surface was placed under the participants' feet to alter the quality and/or quantity of somatosensory information at the foot and the ankle. COP displacements were recorded using a force platform. In the firm support surface condition, no significant difference was observed between the COP-FB2 and the SC-FB conditions, whereas the COP-FB10 condition yielded decreased COP displacements relative to the SC-FB condition. In the foam support surface condition, both the COP-FB2 and the COP-FB10 conditions yielded decreased COP displacements relative to the SC-FB condition, with a greater stabilizing effect in the COP-FB10 than COP-FB2 condition. The postural effects of the scale display of visual COP feedback differed depending on the somatosensory conditions at the foot and the ankle. These findings suggest that increased reliance on augmented sensory information for controlling upright posture in conditions of altered somatosensory input from the foot and ankle could have implications in clinical and rehabilitative areas.

  15. A virtual reality-based method of decreasing transmission time of visual feedback for a tele-operative robotic catheter operating system.

    Science.gov (United States)

    Guo, Jin; Guo, Shuxiang; Tamiya, Takashi; Hirata, Hideyuki; Ishihara, Hidenori

    2016-03-01

    An Internet-based tele-operative robotic catheter operating system was designed for vascular interventional surgery, to afford unskilled surgeons the opportunity to learn basic catheter/guidewire skills, while allowing experienced physicians to perform surgeries cooperatively. Remote surgical procedures, limited by variable transmission times for visual feedback, have been associated with deterioration in operability and vascular wall damage during surgery. At the patient's location, the catheter shape/position was detected in real time and converted into three-dimensional coordinates in a world coordinate system. At the operation location, the catheter shape was reconstructed in a virtual-reality environment, based on the coordinates received. The data volume reduction significantly reduced visual feedback transmission times. Remote transmission experiments, conducted over inter-country distances, demonstrated the improved performance of the proposed prototype. The maximum error for the catheter shape reconstruction was 0.93 mm and the transmission time was reduced considerably. The results were positive and demonstrate the feasibility of remote surgery using conventional network infrastructures. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Interação de variáveis biomecânicas na composição de "feedback" visual aumentado para o ensino do ciclismo Interacción de variables biomecánicas en la composición de feedback visual aumentado para el enseñanza del ciclismo Interaction of biomechanical variables in the composition of visual augmented feedback for learning cycling

    Directory of Open Access Journals (Sweden)

    Guilherme Garcia Holderbaum

    2012-12-01

    Full Text Available O objetivo deste estudo foi testar uma metodologia para o ensino da técnica da pedalada do ciclismo utilizando variáveis biomecánicas para desenvolver um sistema de "feedback" visual aumentado (FVA. Participaram do estudo 19 indivíduos, sem experiência no ciclismo , divididos em grupo experimental (n = 10 e controle (n = 9. Inicialmente foi realizado um pré-teste para determinar o consumo máximo de oxigênio (VO2máx bem como a carga de trabalho utilizada nas sessões práticas que correspondeu a 60% do VO2máx. Em seguida foram realizadas sete sessões de prática. O grupo experimental foi submetido ao FVA e o grupo controle ao "feedback" aumentado (FA. O teste de retenção mostrou um aumento de 21 % na média do índice de efetividade (IE do grupo experimental quando comparado ao grupo controle. Os resultados mostraram que variáveis biomecánicas são apropriadas para o desenvolvimento de FVA e podem contribuir no processo de ensino-aprendizagem da técnica da pedalada do ciclismo.El objetivo de este estudio fue probar una metodología para enseñar la técnica de el ciclismo mediante la utilización de variables biomecánicas para desarrollar un sistema de feedback visual aumentado (FVA. Fue aplicado en 19 personas sin experiencia en el ciclismo, divididos en dos grupos (experimental = 10 y control = 9. Inicialmente se realizó un pre-test para determinar el consumo máximo de oxígeno (VO2max y la carga de trabajo utilizada en las sesiones de práctica que correspondía al 60% del VO2máx. El grupo experimental fue sometido a la FVA y el control a la feedback aumentado (FA. El ensayo de retención mostró un aumento del 21% en la media del índice de eficacia (IE en el grupo experimental en comparación con el grupo control. Los resultados mostraron que las variables biomecánicas son apropiadas para el desarrollo de la FVA y puede contribuir al proceso de enseñanza y aprendizaje del ciclismo.The aim of this study was to test a

  17. Effect of task-related continuous auditory feedback during learning of tracking motion exercises

    Directory of Open Access Journals (Sweden)

    Rosati Giulio

    2012-10-01

    visuomotor perturbation, whereas controller-task-related sound feedback did not. This result was particularly interesting, as the subjects relied more on auditory augmentation of the visualized target motion (which was altered with respect to arm motion by the visuomotor perturbation, rather than on sound feedback provided in the controller space, i.e., information directly related to the effective target motion of their arm. Conclusions Our results indicate that auditory augmentation of visual feedback can be beneficial during the execution of upper limb movement exercises. In particular, we found that continuous task-related information provided through sound, in addition to visual feedback can improve not only performance but also the learning of a novel visuomotor perturbation. However, error-related information provided through sound did not improve performance and negatively affected learning in the presence of the visuomotor perturbation.

  18. Effect of task-related continuous auditory feedback during learning of tracking motion exercises

    Science.gov (United States)

    2012-01-01

    controller-task-related sound feedback did not. This result was particularly interesting, as the subjects relied more on auditory augmentation of the visualized target motion (which was altered with respect to arm motion by the visuomotor perturbation), rather than on sound feedback provided in the controller space, i.e., information directly related to the effective target motion of their arm. Conclusions Our results indicate that auditory augmentation of visual feedback can be beneficial during the execution of upper limb movement exercises. In particular, we found that continuous task-related information provided through sound, in addition to visual feedback can improve not only performance but also the learning of a novel visuomotor perturbation. However, error-related information provided through sound did not improve performance and negatively affected learning in the presence of the visuomotor perturbation. PMID:23046683

  19. Enhanced Motor Imagery Training Using a Hybrid BCI With Feedback.

    Science.gov (United States)

    Yu, Tianyou; Xiao, Jun; Wang, Fangyi; Zhang, Rui; Gu, Zhenghui; Cichocki, Andrzej; Li, Yuanqing

    2015-07-01

    Motor imagery-related mu/beta rhythms, which can be voluntarily modulated by subjects, have been widely used in EEG-based brain computer interfaces (BCIs). Moreover, it has been suggested that motor imagery-specific EEG differences can be enhanced by feedback training. However, the differences observed in the EEGs of naive subjects are typically not sufficient to provide reliable EEG control and thus result in unintended feedback. Such feedback can frustrate subjects and impede training. In this study, a hybrid BCI paradigm combining motor imagery and steady-state visually evoked potentials (SSVEPs) has been proposed to provide effective continuous feedback for motor imagery training. During the initial training sessions, subjects must focus on flickering buttons to evoke SSVEPs as they perform motor imagery tasks. The output/feedback of the hybrid BCI is based on hybrid features consisting of motor imagery- and SSVEP-related brain signals. In this context, the SSVEP plays a more important role than motor imagery in generating feedback. As the training progresses, the subjects can gradually decrease their visual attention to the flickering buttons, provided that the feedback is still effective. In this case, the feedback is mainly based on motor imagery. Our experimental results demonstrate that subjects generate distinguishable brain patterns of hand motor imagery after only five training sessions lasting approximately 1.5 h each. The proposed hybrid feedback paradigm can be used to enhance motor imagery training. This hybrid BCI system with feedback can effectively identify the intentions of the subjects.

  20. Audio Feedback -- Better Feedback?

    Science.gov (United States)

    Voelkel, Susanne; Mello, Luciane V.

    2014-01-01

    National Student Survey (NSS) results show that many students are dissatisfied with the amount and quality of feedback they get for their work. This study reports on two case studies in which we tried to address these issues by introducing audio feedback to one undergraduate (UG) and one postgraduate (PG) class, respectively. In case study one…

  1. Effects of Video-Feedback Interaction Training for Professional Caregivers of Children and Adults with Visual and Intellectual Disabilities

    Science.gov (United States)

    Damen, S.; Kef, S.; Worm, M.; Janssen, M. J.; Schuengel, C.

    2011-01-01

    Background: Individuals in group homes may experience poor quality of social interaction with their professional caregivers, limiting their quality of life. The video-based Contact programme may help caregivers to improve their interaction with clients. Method: Seventy-two caregivers of 12 individuals with visual and intellectual disabilities…

  2. Providing Access and Visualization to Global Cloud Properties from GEO Satellites

    Science.gov (United States)

    Chee, T.; Nguyen, L.; Minnis, P.; Spangenberg, D.; Palikonda, R.; Ayers, J. K.

    2015-12-01

    Providing public access to cloud macro and microphysical properties is a key concern for the NASA Langley Research Center Cloud and Radiation Group. This work describes a tool and method that allows end users to easily browse and access cloud information that is otherwise difficult to acquire and manipulate. The core of the tool is an application-programming interface that is made available to the public. One goal of the tool is to provide a demonstration to end users so that they can use the dynamically generated imagery as an input into their own work flows for both image generation and cloud product requisition. This project builds upon NASA Langley Cloud and Radiation Group's experience with making real-time and historical satellite cloud product imagery accessible and easily searchable. As we see the increasing use of virtual supply chains that provide additional value at each link there is value in making satellite derived cloud product information available through a simple access method as well as allowing users to browse and view that imagery as they need rather than in a manner most convenient for the data provider. Using the Open Geospatial Consortium's Web Processing Service as our access method, we describe a system that uses a hybrid local and cloud based parallel processing system that can return both satellite imagery and cloud product imagery as well as the binary data used to generate them in multiple formats. The images and cloud products are sourced from multiple satellites and also "merged" datasets created by temporally and spatially matching satellite sensors. Finally, the tool and API allow users to access information that spans the time ranges that our group has information available. In the case of satellite imagery, the temporal range can span the entire lifetime of the sensor.

  3. Perils of providing visual health information overviews for consumers with low health literacy or high stress

    Science.gov (United States)

    Miller, Trudi

    2010-01-01

    This pilot study explores the impact of a health topics overview (HTO) on reading comprehension. The HTO is generated automatically based on the presence of Unified Medical Language System terms. In a controlled setting, we presented health texts and posed 15 questions for each. We compared performance with and without the HTO. The answers were available in the text, but not always in the HTO. Our study (n=48) showed that consumers with low health literacy or high stress performed poorly when the HTO was available without linking directly to the answer. They performed better with direct links in the HTO or when the HTO was not available at all. Consumers with high health literacy or low stress performed better regardless of the availability of the HTO. Our data suggests that vulnerable consumers relied solely on the HTO when it was available and were misled when it did not provide the answer. PMID:20190068

  4. Visualizing the Immune System: Providing Key Insights into HIV/SIV Infections

    Directory of Open Access Journals (Sweden)

    Jacob D. Estes

    2018-03-01

    Full Text Available Immunological inductive tissues, such as secondary lymphoid organs, are composed of distinct anatomical microenvironments for the generation of immune responses to pathogens and immunogens. These microenvironments are characterized by the compartmentalization of highly specialized immune and stromal cell populations, as well as the presence of a complex network of soluble factors and chemokines that direct the intra-tissue trafficking of naïve and effector cell populations. Imaging platforms have provided critical contextual information regarding the molecular and cellular interactions that orchestrate the spatial microanatomy of relevant cells and the development of immune responses against pathogens. Particularly in HIV/SIV disease, imaging technologies are of great importance in the investigation of the local interplay between the virus and host cells, with respect to understanding viral dynamics and persistence, immune responses (i.e., adaptive and innate inflammatory responses, tissue structure and pathologies, and changes to the surrounding milieu and function of immune cells. Merging imaging platforms with other cutting-edge technologies could lead to novel findings regarding the phenotype, function, and molecular signatures of particular immune cell targets, further promoting the development of new antiviral treatments and vaccination strategies.

  5. Inter-individual difference in the effect of mirror reflection-induced visual feedback on phantom limb awareness in forearm amputees.

    Science.gov (United States)

    Kawashima, Noritaka; Mita, Tomoki; Yoshikawa, Masahiro

    2013-01-01

    To test whether the phantom limb awareness could be altered by observing mirror reflection-induced visual feedback (MVF) in unilateral forearm amputees. Ten unilateral forearm amputees were asked to perform bilateral (intact and phantom) synchronous wrist motions with and without MVF. During wrist motion, electromyographic activities in the extensor digitorum longus (EDL) and flexor carpi radialis muscles (FCR) were recorded with bipolar electrodes. Degree of wrist range of motion (ROM) was also recorded by electrogoniometry attached to the wrist joint of intact side. Subjects were asked to answer the degree of attainment of phantom limb motion using a visual analog scale (VAS: ranging from 0 (hard) to 10 (easy)). VAS and ROM were significantly increased by utilizing MVF, and the extent of an enhancement of the VAS and wrist ROM was positively correlated (r = 0.72, pphantom limb awareness, MVF has a potential to enhance phantom limb awareness, in case those who has a difficulty for the phantom limb motion. The present result suggests that the motor command to the missing limb can be re-activated by an appropriate therapeutic strategy such as mirror therapy.

  6. High-accuracy brain-machine interfaces using feedback information.

    Directory of Open Access Journals (Sweden)

    Hong Gi Yeom

    Full Text Available Sensory feedback is very important for movement control. However, feedback information has not been directly used to update movement prediction model in the previous BMI studies, although the closed-loop BMI system provides the visual feedback to users. Here, we propose a BMI framework combining image processing as the feedback information with a novel prediction method. The feedback-prediction algorithm (FPA generates feedback information from the positions of objects and modifies movement prediction according to the information. The FPA predicts a target among objects based on the movement direction predicted from the neural activity. After the target selection, the FPA modifies the predicted direction toward the target and modulates the magnitude of the predicted vector to easily reach the target. The FPA repeats the modification in every prediction time points. To evaluate the improvements of prediction accuracy provided by the feedback, we compared the prediction performances with feedback (FPA and without feedback. We demonstrated that accuracy of movement prediction can be considerably improved by the FPA combining feedback information. The accuracy of the movement prediction was significantly improved for all subjects (P<0.001 and 32.1% of the mean error was reduced. The BMI performance will be improved by combining feedback information and it will promote the development of a practical BMI system.

  7. The effect of providing feedback on inhaler technique and adherence from an electronic audio recording device, INCA®, in a community pharmacy setting: study protocol for a randomised controlled trial.

    Science.gov (United States)

    O'Dwyer, Susan Mary; MacHale, Elaine; Sulaiman, Imran; Holmes, Martin; Hughes, Cian; D'Arcy, Shona; Rapcan, Viliam; Taylor, Terence; Boland, Fiona; Bosnic-Anticevich, Sinthia; Reilly, Richard B; Ryder, Sheila A; Costello, Richard W

    2016-05-04

    Poor adherence to inhaled medication may lead to inadequate symptom control in patients with respiratory disease. In practice it can be difficult to identify poor adherence. We designed an acoustic recording device, the INCA® (INhaler Compliance Assessment) device, which, when attached to an inhaler, identifies and records the time and technique of inhaler use, thereby providing objective longitudinal data on an individual's adherence to inhaled medication. This study will test the hypothesis that providing objective, personalised, visual feedback on adherence to patients in combination with a tailored educational intervention in a community pharmacy setting, improves adherence more effectively than education alone. The study is a prospective, cluster randomised, parallel-group, multi-site study conducted over 6 months. The study is designed to compare current best practice in care (i.e. routine inhaler technique training) with the use of the INCA® device for respiratory patients in a community pharmacy setting. Pharmacies are the unit of randomisation and on enrolment to the study they will be allocated by the lead researcher to one of the three study groups (intervention, comparator or control groups) using a computer-generated list of random numbers. Given the nature of the intervention neither pharmacists nor participants can be blinded. The intervention group will receive feedback from the acoustic recording device on inhaler technique and adherence three times over a 6-month period along with inhaler technique training at each of these times. The comparator group will also receive training in inhaler use three times over the 6-month study period but no feedback on their habitual performance. The control group will receive usual care (i.e. the safe supply of medicines and advice on their use). The primary outcome is the rate of participant adherence to their inhaled medication, defined as the proportion of correctly taken doses of medication at the correct

  8. Visualizing multi-channel networks

    DEFF Research Database (Denmark)

    Antemijczuk, Paweł; Magiera, Marta; Jørgensen, Sune Lehmann

    2014-01-01

    In this paper, we propose a visualization to illustrate social interactions, built from multiple distinct channels of communication. The visualization displays a summary of dense personal information in a compact graphical notation. The starting point is an abstract drawing of a spider’s web. Below......, we describe the meaning of each data dimension along with the background and motivation for their inclusion. Finally, we present feedback provided by the users (31 individuals) of the visualization....

  9. Feedback Valence Affects Auditory Perceptual Learning Independently of Feedback Probability

    OpenAIRE

    Amitay, Sygal; Moore, David R.; Molloy, Katharine; Halliday, Lorna F.

    2015-01-01

    Previous studies have suggested that negative feedback is more effective in driving learning than positive feedback. We investigated the effect on learning of providing varying amounts of negative and positive feedback while listeners attempted to discriminate between three identical tones; an impossible task that nevertheless produces robust learning. Four feedback conditions were compared during training: 90% positive feedback or 10% negative feedback informed the participants that they wer...

  10. Review of the Visiting Teachers Service for Children with Hearing and Visual Impairment in Supporting Inclusive Educational Practice in Ireland: Examining Stakeholder Feedback through an Ecological Systems Theory

    Science.gov (United States)

    McLinden, Mike; McCracken, Wendy

    2016-01-01

    In line with recent developments in inclusive practice in Ireland, children with sensory needs are increasingly educated in mainstream rather than specialist provision. Educational supports are provided by a range of practitioners and include input from the visiting teachers service for children with hearing and visual impairment. This paper…

  11. Combining the formative with the summative: the development of a twostage online test to encourage engagement and provide personal feedback in large classes

    National Research Council Canada - National Science Library

    Susanne Voelkel

    2013-01-01

      The aim of this action research project was to improve student learning by encouraging more "time on task" and to improve self-assessment and feedback through the introduction of weekly online tests...

  12. Combining the formative with the summative: the development of a two-stage online test to encourage engagement and provide personal feedback in large classes

    National Research Council Canada - National Science Library

    Voelkel, Susanne

    2013-01-01

    The aim of this action research project was to improve student learning by encouraging more "time on task" and to improve self-assessment and feedback through the introduction of weekly online tests...

  13. Fourier power, subjective distance and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Directory of Open Access Journals (Sweden)

    Mark Daniel Lescroart

    2015-11-01

    Full Text Available Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA, Retrosplenial Complex (RSC, and the Occipital Place Area (OPA. It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1 2D features related to Fourier power; (2 3D spatial features such as the distance to objects in a scene; or (3 abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM to BOLD fMRI responses elicited by a set of 1,386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue.

  14. Fourier power, subjective distance, and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Science.gov (United States)

    Lescroart, Mark D.; Stansbury, Dustin E.; Gallant, Jack L.

    2015-01-01

    Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA), Retrosplenial Complex (RSC), and the Occipital Place Area (OPA). It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1) 2D features related to Fourier power; (2) 3D spatial features such as the distance to objects in a scene; or (3) abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM) to BOLD fMRI responses elicited by a set of 1386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue. PMID:26594164

  15. Unilateral Stability and Visual Feedback Body Control Improves After Three-Month Resistance Training in Overweight Individuals.

    Science.gov (United States)

    Zemková, Erika; Kyselovičová, Ol'ga; Jeleň, Michal; Kováčiková, Zuzana; Ollé, Gábor; Štefániková, Gabriela; Vilman, Tomáš; Baláž, Miroslav; Kurdiová, Timea; Ukropec, Jozef; Ukropcová, Barbara

    2017-01-01

    The authors evaluated the effect of 3 months of resistance and aerobic training (3 sessions/week) on body balance in a group of 25 overweight and obese individuals. Prior to and after the training, they performed static and task-oriented balance tests under various conditions. Mean center of pressure (CoP) velocity and mean trace length of the CoP in the y-axis registered during a one-legged stance significantly decreased after the resistance training (19.1%, p = .024; 29.3%, p = .009). Mean trace length of the CoP in the y-axis decreased significantly also during a bipedal stance on a foam surface with eyes open and closed (10.9%, p = .040; 18.2%, p = .027). In addition, mean CoP distance and mean squared CoP distance in the anteroposterior direction during a visually guided center of mass (CoM) tracking task significantly improved (14.7%, p = .033; 28.2%, p = .016). However, only mean trace length of the CoP in the y-axis during a bipedal stance on a foam surface with eyes open and closed significantly decreased after the aerobic training (10.3%, p = .047; 16.5%, p = .029). It may be concluded that resistance training is more efficient for the improvement of the anteroposterior unilateral stability and the accuracy of the regulation of the CoM anteroposterior position than aerobic training in overweight and obese individuals.

  16. Method and device for intraoperative imaging of lumpectomy specimens to provide feedback to breast surgeon for prompt re-excision during the same procedure

    Science.gov (United States)

    Krol, Andrzej; Hemingway, Susan; Kort, Kara; de la Rosa, Gustavo; Adhikary, Ravi; Masrani, Deepa; Feiglin, David; O'Connell, Avice; Nagarajan, Mahesh; Yang, Chien-Chun; Wismüller, Axel

    2014-03-01

    Breast conserving therapy (BCT) of breast cancer is now widely accepted due to improved cosmetic outcome and improved patients' quality of life. One of the critical issues in performing breast-conserving surgery is trying to achieve microscopically clear surgical margins while maintaining excellent cosmesis. Unfortunately, unacceptably close or positive surgical margins occur in at least 20-25% of all patients undergoing BCT requiring repeat surgical excision days or weeks later, as permanent histopathology routinely takes days to complete. Our aim is to develop a better method for intraoperative imaging of non-palpable breast malignancies excised by wire or needle localization. Providing non-deformed three dimensional imaging of the excised breast tissue should allow more accurate assessment of tumor margins and consequently allow further excision at the time of initial surgery thus limiting the enormous financial and emotional burden of additional surgery. We have designed and constructed a device that allows preservation of the excised breast tissue in its natural anatomic position relative to the breast as it is imaged to assess adequate excision. We performed initial tests with needle-guided lumpectomy specimens using micro-CT and digital breast tomosynthesis (DBT). Our device consists of a plastic sphere inside a cylindrical holder. The surgeon inserts a freshly excised piece of breast tissue into the sphere and matches its anatomic orientation with the fiducial markers on the sphere. A custom-shaped foam is placed inside the sphere to prevent specimen deformation due to gravity. DBT followed by micro-CT images of the specimen were obtained. We confirmed that our device preserved spatial orientation of the excised breast tissue and that the location error was lower than 10mm and 10 degrees. The initial obtained results indicate that breast lesions containing microcalcifications allow a good 3D imaging of margins providing immediate intraoperative feedback for

  17. Neurologist consistency in interpreting information provided by an interactive visualization software for deep brain stimulation postoperative programming assistance.

    Science.gov (United States)

    Pallavaram, Srivatsan; Phibbs, Fenna T; Tolleson, Christopher; Davis, Thomas L; Fang, John; Hedera, Peter; Li, Rui; Koyama, Tatsuki; Dawant, Benoit M; D'Haese, Pierre-François

    2014-01-01

    Postoperative programming in deep brain stimulation (DBS) therapy for movement disorders can be challenging and time consuming. Providing the neurologist with tools to visualize the electrode location relative to the patient's anatomy along with models of tissue activation and statistical data can therefore be very helpful. In this study, we evaluate the consistency between neurologists in interpreting and using such information provided by our DBS programming assistance software. Five neurologists experienced in DBS programming were each given a dataset of 29 leads implanted in 17 patients. For each patient, probabilistic maps of stimulation response, anatomical images, models of tissue activation volumes, and electrode positions were presented inside a software framework called CRAnialVault Explorer (CRAVE) developed in house. Consistency between neurologists in optimal contact selection using the software was measured. With only the efficacy map, the average consistency among the five neurologists with respect to the mode and mean of their selections was 97% and 95%, respectively, while these numbers were 93% and 89%, respectively, when both efficacy and an adverse effect map were used simultaneously. Fleiss' kappa statistic also showed very strong agreement among the neurologists (0.87 when using one map and 0.72 when using two maps). Our five neurologists demonstrated high consistency in interpreting information provided by the CRAVE interactive visualization software for DBS postoperative programming assistance. Three of our five neurologists had no prior experience with the software, which suggests that the software has a short learning curve and contact selection is not dependent on familiarity with the program tools. © 2013 Vanderbilt University.

  18. Evaluation of Augmented Reality Feedback in Surgical Training Environment.

    Science.gov (United States)

    Zahiri, Mohsen; Nelson, Carl A; Oleynikov, Dmitry; Siu, Ka-Chun

    2017-11-01

    Providing computer-based laparoscopic surgical training has several advantages that enhance the training process. Self-evaluation and real-time performance feedback are 2 of these advantages, which avoid dependency of trainees on expert feedback. The goal of this study was to investigate the use of a visual time indicator as real-time feedback correlated with the laparoscopic surgical training. Twenty novices participated in this study working with (and without) different presentations of time indicators. They performed a standard peg transfer task, and their completion times and muscle activity were recorded and compared. Also of interest was whether the use of this type of feedback induced any side effect in terms of motivation or muscle fatigue. Of the 20 participants, 15 (75%) preferred using a time indicator in the training process rather than having no feedback. However, time to task completion showed no significant difference in performance with the time indicator; furthermore, no significant differences in muscle activity or muscle fatigue were detected with/without time feedback. The absence of significant difference between task performance with/without time feedback shows that using visual real-time feedback can be included in surgical training based on user preference. Trainees may benefit from this type of feedback in the form of increased motivation. The extent to which this can influence training frequency leading to performance improvement is a question for further study.

  19. Effects of Vibrotactile Feedback on Human Learning of Arm Motions

    Science.gov (United States)

    Bark, Karlin; Hyman, Emily; Tan, Frank; Cha, Elizabeth; Jax, Steven A.; Buxbaum, Laurel J.; Kuchenbecker, Katherine J.

    2015-01-01

    Tactile cues generated from lightweight, wearable actuators can help users learn new motions by providing immediate feedback on when and how to correct their movements. We present a vibrotactile motion guidance system that measures arm motions and provides vibration feedback when the user deviates from a desired trajectory. A study was conducted to test the effects of vibrotactile guidance on a subject’s ability to learn arm motions. Twenty-six subjects learned motions of varying difficulty with both visual (V), and visual and vibrotactile (VVT) feedback over the course of four days of training. After four days of rest, subjects returned to perform the motions from memory with no feedback. We found that augmenting visual feedback with vibrotactile feedback helped subjects reduce the root mean square (rms) angle error of their limb significantly while they were learning the motions, particularly for 1DOF motions. Analysis of the retention data showed no significant difference in rms angle errors between feedback conditions. PMID:25486644

  20. Inter-individual difference in the effect of mirror reflection-induced visual feedback on phantom limb awareness in forearm amputees.

    Directory of Open Access Journals (Sweden)

    Noritaka Kawashima

    Full Text Available OBJECTIVE: To test whether the phantom limb awareness could be altered by observing mirror reflection-induced visual feedback (MVF in unilateral forearm amputees. METHODS: Ten unilateral forearm amputees were asked to perform bilateral (intact and phantom synchronous wrist motions with and without MVF. During wrist motion, electromyographic activities in the extensor digitorum longus (EDL and flexor carpi radialis muscles (FCR were recorded with bipolar electrodes. Degree of wrist range of motion (ROM was also recorded by electrogoniometry attached to the wrist joint of intact side. Subjects were asked to answer the degree of attainment of phantom limb motion using a visual analog scale (VAS: ranging from 0 (hard to 10 (easy. RESULTS: VAS and ROM were significantly increased by utilizing MVF, and the extent of an enhancement of the VAS and wrist ROM was positively correlated (r = 0.72, p<0.05. Although FCR EMG activity also showed significant enhancement by MVF, this was not correlated with the changes of VAS and ROM. Interestingly, while we found negative correlation between EDL EMG activity and wrist ROM, MVF generally affected to be increasing both EDL EMG and ROM. CONCLUSIONS: Although there was larger extent of variability in the effect of MVF on phantom limb awareness, MVF has a potential to enhance phantom limb awareness, in case those who has a difficulty for the phantom limb motion. The present result suggests that the motor command to the missing limb can be re-activated by an appropriate therapeutic strategy such as mirror therapy.

  1. Strategies for effective feedback

    National Research Council Canada - National Science Library

    Kritek, Patricia A

    2015-01-01

    Provision of regular feedback to trainees on clinical performance by supervising providers is increasingly recognized as an essential component of undergraduate and graduate health sciences education...

  2. An immediate effect of axial neck rotation training with real time visual feedback using a smartphone inclinometer on improvement in axial neck rotation function.

    Science.gov (United States)

    Park, Kyue-Nam; Kwon, Oh-Yun; Kim, Si-Hyun; Jeon, In-Cheol

    2017-03-01

    The purpose of this study was to compare the immediate effects of axial neck rotation training (Axi-NRT) with and without real-time visual feedback (VF) using a smartphone inclinometer on the range of motion (ROM) for axial neck rotation and the onset of compensatory neck lateral bending and extension during active neck rotation. Twenty participants with restricted ROM for neck rotation but no neck pain (21.1 ± 1.6 years and 8 males, 12 females) were recruited for Axi-NRT with VF, and twenty age- and gender-matched participants with restricted ROM for neck rotation were recruited for Axi-NRT without VF. Changes in ROM for neck rotation and the onset time of compensatory neck movement during active neck rotation were measured using an electromagnetic tracking system. Axi-NRT with VF was more effective in increasing ROM for neck rotation and decreasing and delaying the onset of compensatory neck movements during active neck rotation compared with Axi-NRT without VF. Repeated Axi-NRT using VF is useful to educate participants in maintaining the axis of the cervical spine and to increase ROM for axial neck rotation with less compensatory neck motion in participants with a restricted range of neck rotations.

  3. Use of Feedback from Sighted Peers in Promoting Social Interaction Skills

    Science.gov (United States)

    Jindal-Snape, Divya

    2005-01-01

    A boy who was visually impaired was trained to self-evaluate his social interaction, and a sighted peer was trained to provide relevant feedback to the boy through verbal reinforcement by the researcher. This feedback enhanced the boy's social interaction with his sighted peers, improved certain aspects of his social behavior, and increased the…

  4. Combining the Formative with the Summative: The Development of a Two-Stage Online Test to Encourage Engagement and Provide Personal Feedback in Large Classes

    Science.gov (United States)

    Voelkel, Susanne

    2013-01-01

    The aim of this action research project was to improve student learning by encouraging more "time on task" and to improve self-assessment and feedback through the introduction of weekly online tests in a Year 2 lecture module in biological sciences. Initially voluntary online tests were offered to students and those who participated…

  5. Situated Formative Feedback

    DEFF Research Database (Denmark)

    Lukassen, Niels Bech; Wahl, Christian; Sorensen, Elsebeth Korsgaard

    This study addresses the conceptual challenge of providing students with good quality feedback to enhance student learning in an online community of practice (COP). The aim of the study is to identify feedback mechanisms in a virtual learning environment (VLE) and to create a full formative...... feedback episode (FFE) through an online dialogue. The paper argues that dialogue is crucial for student learning and that feedback is not only something the teacher gives to the student. Viewing good quality feedback as social, situated, formative, emphasis is put on the establishment of dialogue. We...... refer to this type of feedback as, Situated Formative Feedback (SFF). As a basis for exploring, identifying and discussing relevant aspects of SFF the paper analyses qualitative data from a Moodle dialogue. Data are embedded in the qualitative analytic program Nvivo and are analysed with a system...

  6. Trifocal intraocular lenses: a comparison of the visual performance and quality of vision provided by two different lens designs

    Directory of Open Access Journals (Sweden)

    Gundersen KG

    2017-06-01

    Full Text Available Kjell G Gundersen,1 Rick Potvin2 1IFocus Øyeklinikk AS, Haugesund, Norway; 2Science in Vision, Akron, NY, USA Purpose: To compare two different diffractive trifocal intraocular lens (IOL designs, evaluating longer-term refractive outcomes, visual acuity (VA at various distances, low contrast VA and quality of vision.Patients and methods: Patients with binocularly implanted trifocal IOLs of two different designs (FineVision [FV] and Panoptix [PX] were evaluated 6 months to 2 years after surgery. Best distance-corrected and uncorrected VA were tested at distance (4 m, intermediate (80 and 60 cm and near (40 cm. A binocular defocus curve was collected with the subject’s best distance correction in place. The preferred reading distance was determined along with the VA at that distance. Low contrast VA at distance was also measured. Quality of vision was measured with the National Eye Institute Visual Function Questionnaire near subset and the Quality of Vision questionnaire.Results: Thirty subjects in each group were successfully recruited. The binocular defocus curves differed only at vergences of −1.0 D (FV better, P=0.02, −1.5 and −2.00 D (PX better, P<0.01 for both. Best distance-corrected and uncorrected binocular vision were significantly better for the PX lens at 60 cm (P<0.01 with no significant differences at other distances. The preferred reading distance was between 42 and 43 cm for both lenses, with the VA at the preferred reading distance slightly better with the PX lens (P=0.04. There were no statistically significant differences by lens for low contrast VA (P=0.1 or for quality of vision measures (P>0.3.Conclusion: Both trifocal lenses provided excellent distance, intermediate and near vision, but several measures indicated that the PX lens provided better intermediate vision at 60 cm. This may be important to users of tablets and other handheld devices. Quality of vision appeared similar between the two lens designs

  7. Feedback Valence Affects Auditory Perceptual Learning Independently of Feedback Probability

    Science.gov (United States)

    Amitay, Sygal; Moore, David R.; Molloy, Katharine; Halliday, Lorna F.

    2015-01-01

    Previous studies have suggested that negative feedback is more effective in driving learning than positive feedback. We investigated the effect on learning of providing varying amounts of negative and positive feedback while listeners attempted to discriminate between three identical tones; an impossible task that nevertheless produces robust learning. Four feedback conditions were compared during training: 90% positive feedback or 10% negative feedback informed the participants that they were doing equally well, while 10% positive or 90% negative feedback informed them they were doing equally badly. In all conditions the feedback was random in relation to the listeners’ responses (because the task was to discriminate three identical tones), yet both the valence (negative vs. positive) and the probability of feedback (10% vs. 90%) affected learning. Feedback that informed listeners they were doing badly resulted in better post-training performance than feedback that informed them they were doing well, independent of valence. In addition, positive feedback during training resulted in better post-training performance than negative feedback, but only positive feedback indicating listeners were doing badly on the task resulted in learning. As we have previously speculated, feedback that better reflected the difficulty of the task was more effective in driving learning than feedback that suggested performance was better than it should have been given perceived task difficulty. But contrary to expectations, positive feedback was more effective than negative feedback in driving learning. Feedback thus had two separable effects on learning: feedback valence affected motivation on a subjectively difficult task, and learning occurred only when feedback probability reflected the subjective difficulty. To optimize learning, training programs need to take into consideration both feedback valence and probability. PMID:25946173

  8. Encouraging residents to seek feedback.

    Science.gov (United States)

    Delva, Dianne; Sargeant, Joan; Miller, Stephen; Holland, Joanna; Alexiadis Brown, Peggy; Leblanc, Constance; Lightfoot, Kathryn; Mann, Karen

    2013-12-01

    To explore resident and faculty perceptions of the feedback process, especially residents' feedback-seeking activities. We conducted focus groups of faculty and residents exploring experiences in giving and receiving feedback, feedback-seeking, and suggestions to support feedback-seeking. Using qualitative methods and an iterative process, all authors analyzed the transcribed audiotapes to identify and confirm themes. Emerging themes fit a framework situating resident feedback-seeking as dependent on four central factors: (1) learning/workplace culture, (2) relationships, (3) purpose/quality of feedback, (4) emotional responses to feedback. Residents and faculty agreed on many supports and barriers to feedback-seeking. Strengthening the workplace/learning culture through longitudinal experiences, use of feedback forms and explicit expectations for residents to seek feedback, coupled with providing a sense of safety and adequate time for observation and providing feedback were suggested. Tensions between faculty and resident perceptions regarding feedback-seeking related to fear of being found deficient, the emotional costs related to corrective feedback and perceptions that completing clinical work is more valued than learning. Resident feedback-seeking is influenced by multiple factors requiring attention to both faculty and learner roles. Further study of specific influences and strategies to mitigate the tensions will inform how best to support residents in seeking feedback.

  9. Visual field

    Science.gov (United States)

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam. This is a quick and basic check of the visual field. The health care provider ...

  10. Interface Prostheses With Classifier-Feedback-Based User Training.

    Science.gov (United States)

    Fang, Yinfeng; Zhou, Dalin; Li, Kairu; Liu, Honghai

    It is evident that user training significantly affects performance of pattern-recognition-based myoelectric prosthetic device control. Despite plausible classification accuracy on offline datasets, online accuracy usually suffers from the changes in physiological conditions and electrode displacement. The user ability in generating consistent electromyographic (EMG) patterns can be enhanced via proper user training strategies in order to improve online performance. This study proposes a clustering-feedback strategy that provides real-time feedback to users by means of a visualized online EMG signal input as well as the centroids of the training samples, whose dimensionality is reduced to minimal number by dimension reduction. Clustering feedback provides a criterion that guides users to adjust motion gestures and muscle contraction forces intentionally. The experiment results have demonstrated that hand motion recognition accuracy increases steadily along the progress of the clustering-feedback-based user training, while conventional classifier-feedback methods, i.e., label feedback, hardly achieve any improvement. The result concludes that the use of proper classifier feedback can accelerate the process of user training, and implies prosperous future for the amputees with limited or no experience in pattern-recognition-based prosthetic device manipulation.It is evident that user training significantly affects performance of pattern-recognition-based myoelectric prosthetic device control. Despite plausible classification accuracy on offline datasets, online accuracy usually suffers from the changes in physiological conditions and electrode displacement. The user ability in generating consistent electromyographic (EMG) patterns can be enhanced via proper user training strategies in order to improve online performance. This study proposes a clustering-feedback strategy that provides real-time feedback to users by means of a visualized online EMG signal input as well

  11. Positive feedback of NR2B-containing NMDA receptor activity is the initial step toward visual imprinting: a model for juvenile learning.

    Science.gov (United States)

    Nakamori, Tomoharu; Sato, Katsushige; Kinoshita, Masae; Kanamatsu, Tomoyuki; Sakagami, Hiroyuki; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2015-01-01

    Imprinting in chicks is a good model for elucidating the processes underlying neural plasticity changes during juvenile learning. We recently reported that neural activation of a telencephalic region, the core region of the hyperpallium densocellulare (HDCo), was critical for success of visual imprinting, and that N-Methyl-D-aspartic (NMDA) receptors containing the NR2B subunit (NR2B/NR1) in this region were essential for imprinting. Using electrophysiological and multiple-site optical imaging techniques with acute brain slices, we found that long-term potentiation (LTP) and enhancement of NR2B/NR1 currents in HDCo neurons were induced in imprinted chicks. Enhancement of NR2B/NR1 currents as well as an increase in surface NR2B expression occurred even following a brief training that was too weak to induce LTP or imprinting behavior. This means that NR2B/NR1 activation is the initial step of learning, well before the activation of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors which induces LTP. We also showed that knockdown of NR2B/NR1 inhibited imprinting, and inversely, increasing the surface NR2B expression by treatment with a casein kinase 2 inhibitor successfully reduced training time required for imprinting. These results suggest that imprinting stimuli activate post-synaptic NR2B/NR1 in HDCo cells, increase NR2B/NR1 signaling through up-regulation of its expression, and induce LTP and memory acquisition. The study investigated the neural mechanism underlying juvenile learning. In the initial stage of chick imprinting, NMDA receptors containing the NMDA receptor subunit 2B (NR2B) are activated, surface expression of NR2B/NR1 (NMDA receptor subunit 1) is up-regulated, and consequently long-term potentiation is induced in the telencephalic neurons. We suggest that the positive feedback in the NR2B/NR1 activation is a unique process of juvenile learning, exhibiting rapid memory acquisition. © 2014 International Society for Neurochemistry.

  12. Patient DF's visual brain in action: Visual feedforward control in visual form agnosia.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Barat, Masihullah; Goodale, Melvyn A

    2015-05-01

    Patient DF, who developed visual form agnosia following ventral-stream damage, is unable to discriminate the width of objects, performing at chance, for example, when asked to open her thumb and forefinger a matching amount. Remarkably, however, DF adjusts her hand aperture to accommodate the width of objects when reaching out to pick them up (grip scaling). While this spared ability to grasp objects is presumed to be mediated by visuomotor modules in her relatively intact dorsal stream, it is possible that it may rely abnormally on online visual or haptic feedback. We report here that DF's grip scaling remained intact when her vision was completely suppressed during grasp movements, and it still dissociated sharply from her poor perceptual estimates of target size. We then tested whether providing trial-by-trial haptic feedback after making such perceptual estimates might improve DF's performance, but found that they remained significantly impaired. In a final experiment, we re-examined whether DF's grip scaling depends on receiving veridical haptic feedback during grasping. In one condition, the haptic feedback was identical to the visual targets. In a second condition, the haptic feedback was of a constant intermediate width while the visual target varied trial by trial. Despite this incongruent feedback, DF still scaled her grip aperture to the visual widths of the target blocks, showing only normal adaptation to the false haptically-experienced width. Taken together, these results strengthen the view that DF's spared grasping relies on a normal mode of dorsal-stream functioning, based chiefly on visual feedforward processing. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Factors associated with the modulation of pain by visual distortion of body size.

    OpenAIRE

    Michihiro eOsumi; Ryota eImai; Kozo eUeta; Hideki eNakano; Satoshi eNobusako; Shu eMorioka

    2014-01-01

    Modulation of pain using visual distortion of body size (VDBS) has been the subject of various reports. However, the mechanism underlying the effect of VDBS on pain has been less often studied. In the present study, factors associated with modulation of pain threshold by VDBS were investigated. Visual feedback in the form of a magnified image of the hand was provided to 44 healthy adults to examine changes in pain. In participants with a higher pain threshold when visual feedback of a magnifi...

  14. 3D WEB VISUALIZATION OF ENVIRONMENTAL INFORMATION – INTEGRATION OF HETEROGENEOUS DATA SOURCES WHEN PROVIDING NAVIGATION AND INTERACTION

    Directory of Open Access Journals (Sweden)

    L. Herman

    2015-08-01

    Full Text Available 3D information is essential for a number of applications used daily in various domains such as crisis management, energy management, urban planning, and cultural heritage, as well as pollution and noise mapping, etc. This paper is devoted to the issue of 3D modelling from the levels of buildings to cities. The theoretical sections comprise an analysis of cartographic principles for the 3D visualization of spatial data as well as a review of technologies and data formats used in the visualization of 3D models. Emphasis was placed on the verification of available web technologies; for example, X3DOM library was chosen for the implementation of a proof-of-concept web application. The created web application displays a 3D model of the city district of Nový Lískovec in Brno, the Czech Republic. The developed 3D visualization shows a terrain model, 3D buildings, noise pollution, and other related information. Attention was paid to the areas important for handling heterogeneous input data, the design of interactive functionality, and navigation assistants. The advantages, limitations, and future development of the proposed concept are discussed in the conclusions.

  15. Online feedback op schriftelijk werk: betere feedback in minder tijd.

    NARCIS (Netherlands)

    van den Berg, B.A.M.; van der Hulst, M.E.

    2015-01-01

    Feedback is a powerful teaching technic to raise students’ performance, provided that the feedback is informative on how to improve, is given in a timely manner and students have the opportunity to act upon it. Therefore, many institutions want their students to receive feedback on their performance

  16. The influence of visual feedback from the recent past on the programming of grip aperture is grasp-specific, shared between hands, and mediated by sensorimotor memory not task set.

    Science.gov (United States)

    Tang, Rixin; Whitwell, Robert L; Goodale, Melvyn A

    2015-05-01

    Goal-directed movements, such as reaching out to grasp an object, are necessarily constrained by the spatial properties of the target such as its size, shape, and position. For example, during a reach-to-grasp movement, the peak width of the aperture formed by the thumb and fingers in flight (peak grip aperture, PGA) is linearly related to the target's size. Suppressing vision throughout the movement (visual open loop) has a small though significant effect on this relationship. Visual open loop conditions also produce a large increase in the PGA compared to when vision is available throughout the movement (visual closed loop). Curiously, this differential effect of the availability of visual feedback is influenced by the presentation order: the difference in PGA between closed- and open-loop trials is smaller when these trials are intermixed (an effect we have called 'homogenization'). Thus, grasping movements are affected not only by the availability of visual feedback (closed loop or open loop) but also by what happened on the previous trial. It is not clear, however, whether this carry-over effect is mediated through motor (or sensorimotor) memory or through the interference of different task sets for closed-loop and open-loop feedback that determine when the movements are fully specified. We reasoned that sensorimotor memory, but not a task set for closed and open loop feedback, would be specific to the type of response. We tested this prediction in a condition in which pointing to targets was alternated with grasping those same targets. Critically, in this condition, when pointing was performed in open loop, grasping was always performed in closed loop (and vice versa). Despite the fact that closed- and open-loop trials were alternating in this condition, we found no evidence for homogenization of the PGA. Homogenization did occur, however, in a follow-up experiment in which grasping movements and visual feedback were alternated between the left and the right

  17. Formativ Feedback

    DEFF Research Database (Denmark)

    Hyldahl, Kirsten Kofod

    Denne bog undersøger, hvordan lærere kan anvende feedback til at forbedre undervisningen i klasselokalet. I denne sammenhæng har John Hattie, professor ved Melbourne Universitet, udviklet en model for feedback, hvilken er baseret på synteser af meta-analyser. I 2009 udgav han bogen "Visible...

  18. Starting Block Performance in Sprinters: A Statistical Method for Identifying Discriminative Parameters of the Performance and an Analysis of the Effect of Providing Feedback over a 6-Week Period.

    Science.gov (United States)

    Fortier, Sylvie; Basset, Fabien A; Mbourou, Ginette A; Favérial, Jérôme; Teasdale, Normand

    2005-06-01

    (a) to examine if kinetic and kinematic parameters of the sprint start could differentiate elite from sub-elite sprinters and, (b) to investigate whether providing feedback (FB) about selected parameters could improve starting block performance of intermediate sprinters over a 6-week training period. Twelve male sprinters, assigned to an elite or a sub-elite group, participated in Experiment 1. Eight intermediate sprinters participated in Experiment 2. All athletes were required to perform three sprint starts at maximum intensity followed by a 10-m run. To detect differences between elite and sub-elite groups, comparisons were made using t-tests for independent samples. Parameters reaching a significant group difference were retained for the linear discriminant analysis (LDA). The LDA yielded four discriminative kinetic parameters. Feedback about these selected parameters was given to sprinters in Experiment 2. For this experiment, data acquisition was divided into three periods. The first six sessions were without specific FB, whereas the following six sessions were enriched by kinetic FB. Finally, athletes underwent a retention session (without FB) 4 weeks after the twelfth session. Even though differences were found in the time to front peak force, the time to rear peak force, and the front peak force in the retention session, the results of the present study showed that providing FB about selected kinetic parameters differentiating elite from sub-elite sprinters did not improve the starting block performance of intermediate sprinters. Key PointsThe linear discriminative analysis allows the identification of starting block parameters differentiating elite from sub-elite athletes.6-week of feedback does not alter starting block performance in training context.The present results failed to confirm previous studies since feedback did not improve targeted kinetic parameters of the complex motor task in real-world context.

  19. A Journey towards Sustainable Feedback

    Science.gov (United States)

    Mutch, Allyson; Young, Charlotte; Davey, Tamzyn; Fitzgerald, Lisa

    2018-01-01

    Meeting students' expectations associated with the provision of feedback is a perennial challenge for tertiary education. Efforts to provide comprehensive, timely feedback within our own first year undergraduate public health courses have not always met students' expectations. In response, we sought to develop peer feedback activities to support…

  20. Effect of Real-Time Feedback on Screw Placement Into Synthetic Cancellous Bone.

    Science.gov (United States)

    Gustafson, Peter A; Geeslin, Andrew G; Prior, David M; Chess, Joseph L

    2016-08-01

    The objective of this study is to evaluate whether real-time torque feedback may reduce the occurrence of stripping when inserting nonlocking screws through fracture plates into synthetic cancellous bone. Five attending orthopaedic surgeons and 5 senior level orthopaedic residents inserted 8 screws in each phase. In phase I, screws were inserted without feedback simulating conventional techniques. In phase II, screws were driven with visual torque feedback. In phase III, screws were again inserted with conventional techniques. Comparison of these 3 phases with respect to screw insertion torque, surgeon rank, and perception of stripping was used to establish the effects of feedback. Seventy-three of 239 screws resulted in stripping. During the first phase, no feedback was provided and the overall strip rate was 41.8%; this decreased to 15% with visual feedback (P perception of tactile sensation. This is significantly improved with utilization of real-time visual feedback of a torque versus roll curve. This concept of real-time feedback seems beneficial toward performance in synthetic cancellous bone and may lead to improved fixation in cancellous bone in a surgical setting.

  1. [LAMINAR LOCATION OF NEURONS PROVIDING INTERHEMISPHERIC CONNECTIONS IN THE VISUAL CORTEX IN CATS WITH IMPAIRMENTS OF BINOCULAR VISION].

    Science.gov (United States)

    Toporova, S N; Shkorbatova, P Yu; Alekseyenko, S V

    2015-01-01

    The distributio of cells in the visual cortical layers of intact cats (n=7) and cats with experimentally induced strabismus (n=10) and monocular deprivation (n=5) was studied after microiontophoretic injection of horseradish peroxidase into the ocular-dominance columns in areas 17, 18 and the transition zone 17/18. It was found that in cats with impaired binocular vision, the callosal cells were located deeper in layers of I/II, and higher - in layer IV, as compared to those in intact cats. Also in cats with impaired binocular vision, the proportion of callosal cells in layer IV was increased, while in layers II/III it was reduced as compared to intact cats. The most pronounced changes were noted in monocular deprived animals. These findings suggest an important role of sensory input in the formation of the callosal neurons layer distribution.

  2. [The size of cells providing interhemispheric and intrahemispheric connections in the visual cortex of binocular vision-impaired cats].

    Science.gov (United States)

    Alekseenko, S V; Toporova, S N; Shkorbatova, P Iu

    2011-03-01

    The size (somatic area) of 658 cells located in layers 2/3 of cortical areas 17, 18 of both hemispheres in intact monocularly deprived and bilateral strabismic cats was measured. These cells were retrogradely labelled after injections of horseradish peroxidase into ocular dominance columns in areas 17, 18. In all groups of cats, the mean somatic area of callosal cells was significantly larger than the mean somatic area of intrahemispheric cells. It was found that the mean somatic area of callosal cells was increased by 26.6% in monocularly deprived cats and by 20.2% in strabismic cats in relation to the mean somatic area of callosal cells in intact cats. In addition, the mean somatic area of intrahemispheric cells in monocularly deprived cats was indistinguishable from the mean somatic area of intrahemispheric cells in strabismic cats and in intact cats. It is concluded that early binocular vision impairments produce enlargement of callosal cells' size in the visual cortex.

  3. LEARNERS: Interdisciplinary Learning Technology Projects Provide Visualizations and Simulations for Use of Geospatial Data in the Classroom

    Science.gov (United States)

    Farrell, N.; Hoban, S.

    2001-05-01

    The NASA Leading Educators to Applications, Research and NASA-related Educational Resources in Science (LEARNERS) initiative supports seven projects for enhancing kindergarten-to-high school science, geography, technology and mathematics education through Internet-based products derived from content on NASA's mission. Topics incorporated in LEARNERS projects include remote sensing of the Earth for agriculture and weather/climate studies, virtual exploration of remote worlds using robotics and digital imagery. Learners are engaged in inquiry or problem-based learning, often assuming the role of an expert scientist as part of an interdisciplinary science team, to study and explain practical problems using real-time NASA data. The presentation/poster will demonstrate novel uses of remote sensing data for K-12 and Post-Secondary students. This will include the use of visualizations, tools for educators, datasets, and classroom scenarios.

  4. Strategies for effective feedback.

    Science.gov (United States)

    Kritek, Patricia A

    2015-04-01

    Provision of regular feedback to trainees on clinical performance by supervising providers is increasingly recognized as an essential component of undergraduate and graduate health sciences education; however, many individuals have not been formally trained in this pedagogical skill. At the bedside or in the clinic, effective performance feedback can be accomplished by following four key steps. Begin by setting expectations that incorporate the trainee's personal goals and external objectives. Delineate how and when you will provide feedback to the learner. Next, directly observe the trainee's performance. This can be challenging while engaged on a busy clinical service, but a focus on discrete activities or interactions (e.g., family meeting, intravascular volume assessment using bedside ultrasound, or obtaining informed consent) is helpful. The third step is to plan and prioritize the feedback session. Feedback is most effective when given in a timely fashion and delivered in a safe environment. Limit the issues addressed because learners often disengage if confronted with too many deficiencies. Finally, when delivering feedback, begin by listening to the trainee's self-evaluation and then take a balanced approach. Describe in detail what the trainee does well and discuss opportunities for improvement with emphasis on specific, modifiable behaviors. The feedback loop is completed with a plan for follow-up reassessment. Through the use of these relatively simple practices, both the trainee and teacher can have a more productive learning experience.

  5. Timing matters: The impact of immediate and delayed feedback on artificial language learning

    Directory of Open Access Journals (Sweden)

    Bertram Opitz

    2011-02-01

    Full Text Available In the present experiment, we used event-related potentials (ERP to investigate the role of immediate and delayed feedback in an artificial grammar learning task. Two groups of participants were engaged in classifying non-word strings according to an underlying rule system, not known to the participants. Visual feedback was provided after each classification either immediately or with a short delay of one second. Both groups were able to learn the artificial grammar system as indicated by an increase in classification performance. However, the gain in performance was significantly larger for the group receiving immediate feedback as compared to the group receiving delayed feedback. Learning was accompanied by an increase in P300 activity in the ERP for delayed as compared to immediate feedback. Irrespective of feedback delay, both groups exhibited learning related decreases in the feedback-related positivity (FRP elicited by positive feedback only. The feedback-related negativity (FRN, however, remained constant over the course of learning. These results suggest, first, that delayed feedback is less effective for artificial grammar learning as task requirements are very demanding, and second, that the FRP elicited by positive prediction errors decreases with learning while the FRN to negative prediction errors is elicited in an all-or-none fashion by negative feedback throughout the entire experiment.

  6. Designing feedback to mitigate teen distracted driving: A social norms approach.

    Science.gov (United States)

    Merrikhpour, Maryam; Donmez, Birsen

    2017-07-01

    The purpose of this research is to investigate teens' perceived social norms and whether providing normative information can reduce distracted driving behaviors among them. Parents are among the most important social referents for teens; they have significant influences on teens' driving behaviors, including distracted driving which significantly contributes to teens' crash risks. Social norms interventions have been successfully applied in various domains including driving; however, this approach is yet to be explored for mitigating driver distraction among teens. Forty teens completed a driving simulator experiment while performing a self-paced visual-manual secondary task in four between-subject conditions: a) social norms feedback that provided a report at the end of each drive on teens' distracted driving behavior, comparing their distraction engagement to their parent's, b) post-drive feedback that provided just the report on teens' distracted driving behavior without information on their parents, c) real-time feedback in the form of auditory warnings based on eyes of road-time, and d) no feedback as control. Questionnaires were administered to collect data on these teens' and their parents' self-reported engagement in driver distractions and the associated social norms. Social norms and real-time feedback conditions resulted in significantly smaller average off-road glance duration, rate of long (>2s) off-road glances, and standard deviation of lane position compared to no feedback. Further, social norms feedback decreased brake response time and percentage of time not looking at the road compared to no feedback. No major effect was observed for post-drive feedback. Questionnaire results suggest that teens appeared to overestimate parental norms, but no effect of feedback was found on their perceptions. Feedback systems that leverage social norms can help mitigate driver distraction among teens. Overall, both social norms and real-time feedback induced

  7. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a ?natural? grasping task induces pantomime-like grasps

    OpenAIRE

    Whitwell, Robert L.; Ganel, Tzvi; Byrne, Caitlin M.; Goodale, Melvyn A.

    2015-01-01

    Investigators study the kinematics of grasping movements (prehension) under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. ?Natural? prehensile acts are directed at the goal object and are executed using real-time vision. Typically, they also entail the use of tactile, proprioceptive, and kinesthetic sources of haptic feedback about the object (?haptics-based object information?) once contact with the object has been made. Natural and simulated (...

  8. Real-time vision, tactile cues, and visual form agnosia: removing haptic feedback from a “natural” grasping task induces pantomime-like grasps

    OpenAIRE

    Whitwell, Robert L.; Ganel, Tzvi; Byrne, Caitlin M.; Goodale, Melvyn A.

    2015-01-01

    Investigators study the kinematics of grasping movements (prehension) under a variety of conditions to probe visuomotor function in normal and brain-damaged individuals. “Natural” prehensile acts are directed at the goal object and are executed using real-time vision. Typically, they also entail the use of tactile, proprioceptive, and kinesthetic sources of haptic feedback about the object (“haptics-based object information”) once contact with the object has been made. Natural and simulated (...

  9. Direct Visual Editing of Node Attributes in Graphs

    Directory of Open Access Journals (Sweden)

    Christian Eichner

    2016-10-01

    Full Text Available There are many expressive visualization techniques for analyzing graphs. Yet, there is only little research on how existing visual representations can be employed to support data editing. An increasingly relevant task when working with graphs is the editing of node attributes. We propose an integrated visualize-and-edit approach to editing attribute values via direct interaction with the visual representation. The visualize part is based on node-link diagrams paired with attribute-dependent layouts. The edit part is as easy as moving nodes via drag-and-drop gestures. We present dedicated interaction techniques for editing quantitative as well as qualitative attribute data values. The benefit of our novel integrated approach is that one can directly edit the data while the visualization constantly provides feedback on the implications of the data modifications. Preliminary user feedback indicates that our integrated approach can be a useful complement to standard non-visual editing via external tools.

  10. STARTING BLOCK PERFORMANCE IN SPRINTERS: A STATISTICAL METHOD FOR IDENTIFYING DISCRIMINATIVE PARAMETERS OF THE PERFORMANCE AND AN ANALYSIS OF THE EFFECT OF PROVIDING FEEDBACK OVER A 6-WEEK PERIOD

    Directory of Open Access Journals (Sweden)

    Sylvie Fortier

    2005-06-01

    Full Text Available The purpose of this study was twofold: (a to examine if kinetic and kinematic parameters of the sprint start could differentiate elite from sub-elite sprinters and, (b to investigate whether providing feedback (FB about selected parameters could improve starting block performance of intermediate sprinters over a 6-week training period. Twelve male sprinters, assigned to an elite or a sub-elite group, participated in Experiment 1. Eight intermediate sprinters participated in Experiment 2. All athletes were required to perform three sprint starts at maximum intensity followed by a 10-m run. To detect differences between elite and sub-elite groups, comparisons were made using t-tests for independent samples. Parameters reaching a significant group difference were retained for the linear discriminant analysis (LDA. The LDA yielded four discriminative kinetic parameters. Feedback about these selected parameters was given to sprinters in Experiment 2. For this experiment, data acquisition was divided into three periods. The first six sessions were without specific FB, whereas the following six sessions were enriched by kinetic FB. Finally, athletes underwent a retention session (without FB 4 weeks after the twelfth session. Even though differences were found in the time to front peak force, the time to rear peak force, and the front peak force in the retention session, the results of the present study showed that providing FB about selected kinetic parameters differentiating elite from sub-elite sprinters did not improve the starting block performance of intermediate sprinters

  11. Social feedback processing from early to late adolescence: influence of sex, age, and attachment style

    Science.gov (United States)

    Vrtička, Pascal; Sander, David; Anderson, Brittany; Badoud, Deborah; Eliez, Stephan; Debbané, Martin

    2014-01-01

    Objective The establishment of an accurate understanding of one's social context is a central developmental task during adolescence. A critical component of such development is to learn how to integrate the objective evaluation of one's behavior with the social response to the latter—here referred to as social feedback processing. Case report We measured brain activity by means of fMRI in 33 healthy adolescents (12–19 years old, 14 females). Participants played a difficult perceptual game with integrated verbal and visual feedback. Verbal feedback provided the participants with objective performance evaluation (won vs. lost). Visual feedback consisted of either smiling or angry faces, representing positive or negative social evaluations. Together, the combination of verbal and visual feedback gave rise to congruent versus incongruent social feedback combinations. In addition to assessing sex differences, we further tested for the effects of age and attachment style on social feedback processing. Results revealed that brain activity during social feedback processing was significantly modulated by sex, age, and attachment style in prefrontal cortical areas, ventral anterior cingulate cortex, anterior insula, caudate, and amygdala/hippocampus. We found indication for heightened activity during incongruent social feedback processing in females, older participants, and individuals with an anxious attachment style. Conversely, we observed stronger activity during processing of congruent social feedback in males and participants with an avoidant attachment style. Conclusion Our findings not only extend knowledge on the typical development of socio-emotional brain function during adolescence, but also provide first clues on how attachment insecurities, and particularly attachment avoidance, could interfere with the latter mechanisms. PMID:25328847

  12. Traffic Visualization

    DEFF Research Database (Denmark)

    Picozzi, Matteo; Verdezoto, Nervo; Pouke, Matti

    2013-01-01

    techniques to give a rapid overview of traffic data. We illustrate our approach as a case study for traffic visualization systems, using datasets from the city of Oulu that can be extended to other city planning activities. We also report the feedback of real users (traffic management employees, traffic police...

  13. GIVING AND RECEIVING CONSTRUCTIVE FEEDBACK

    Directory of Open Access Journals (Sweden)

    Ірина Олійник

    2015-05-01

    Full Text Available The article scrutinizes the notion of feedback applicable in classrooms where team teaching is provided. The experience of giving and receiving feedback has been a good practice in cooperation between a U.S. Peace Corps volunteer and a Ukrainian counterpart. Giving and receiving feedback is an effective means of classroom observation that provides better insight into the process of teaching a foreign language. The article discusses the stages of feedback and explicates the notion of sharing experience between two teachers working simultaneously in the same classroom. The guidelines for giving and receiving feedback have been provided as well as the most commonly used vocabulary items have been listed. It has been proved that mutual feedback leads to improving teaching methods and using various teaching styles and techniques.

  14. Visual displays that directly interface and provide read-outs of molecular states via molecular graphics processing units.

    Science.gov (United States)

    Poje, Julia E; Kastratovic, Tamara; Macdonald, Andrew R; Guillermo, Ana C; Troetti, Steven E; Jabado, Omar J; Fanning, M Leigh; Stefanovic, Darko; Macdonald, Joanne

    2014-08-25

    The monitoring of molecular systems usually requires sophisticated technologies to interpret nanoscale events into electronic-decipherable signals. We demonstrate a new method for obtaining read-outs of molecular states that uses graphics processing units made from molecular circuits. Because they are made from molecules, the units are able to directly interact with molecular systems. We developed deoxyribozyme-based graphics processing units able to monitor nucleic acids and output alphanumerical read-outs via a fluorescent display. Using this design we created a molecular 7-segment display, a molecular calculator able to add and multiply small numbers, and a molecular automaton able to diagnose Ebola and Marburg virus sequences. These molecular graphics processing units provide insight for the construction of autonomous biosensing devices, and are essential components for the development of molecular computing platforms devoid of electronics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Haptic feedback for virtual assembly

    Science.gov (United States)

    Luecke, Greg R.; Zafer, Naci

    1998-12-01

    Assembly operations require high speed and precision with low cost. The manufacturing industry has recently turned attenuation to the possibility of investigating assembly procedures using graphical display of CAD parts. For these tasks, some sort of feedback to the person is invaluable in providing a real sense of interaction with virtual parts. This research develops the use of a commercial assembly robot as the haptic display in such tasks. For demonstration, a peg-hole insertion task is studied. Kane's Method is employed to derive the dynamics of the peg and the contact motions between the peg and the hole. A handle modeled as a cylindrical peg is attached to the end effector of a PUMA 560 robotic arm. The arm is handle modeled as a cylindrical peg is attached to the end effector of a PUMA 560 robotic arm. The arm is equipped with a six axis force/torque transducer. The use grabs the handle and the user-applied forces are recorded. A 300 MHz Pentium computer is used to simulate the dynamics of the virtual peg and its interactions as it is inserted in the virtual hole. The computed torque control is then employed to exert the full dynamics of the task to the user hand. Visual feedback is also incorporated to help the user in the process of inserting the peg into the hole. Experimental results are presented to show several contact configurations for this virtually simulated task.

  16. Fast feedback for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, L.; Adolphsen, C.; Allison, S.; Gromme, T.; Grossberg, P.; Himel, T.; Krauter, K.; MacKenzie, R.; Minty, M.; Sass, R. [and others

    1995-05-01

    A fast feedback system provides beam stabilization for the SLC. As the SLC is in some sense a prototype for future linear colliders, this system may be a prototype for future feedbacks. The SLC provides a good base of experience for feedback requirements and capabilities as well as a testing ground for performance characteristics. The feedback system controls a wide variety of machine parameters throughout the SLC and associated experiments, including regulation of beam position, angle, energy, intensity and timing parameters. The design and applications of the system are described, in addition to results of recent performance studies.

  17. Vibrotactile Feedback for Brain-Computer Interface Operation

    Directory of Open Access Journals (Sweden)

    Febo Cincotti

    2007-01-01

    Full Text Available To be correctly mastered, brain-computer interfaces (BCIs need an uninterrupted flow of feedback to the user. This feedback is usually delivered through the visual channel. Our aim was to explore the benefits of vibrotactile feedback during users' training and control of EEG-based BCI applications. A protocol for delivering vibrotactile feedback, including specific hardware and software arrangements, was specified. In three studies with 33 subjects (including 3 with spinal cord injury, we compared vibrotactile and visual feedback, addressing: (I the feasibility of subjects' training to master their EEG rhythms using tactile feedback; (II the compatibility of this form of feedback in presence of a visual distracter; (III the performance in presence of a complex visual task on the same (visual or different (tactile sensory channel. The stimulation protocol we developed supports a general usage of the tactors; preliminary experimentations. All studies indicated that the vibrotactile channel can function as a valuable feedback modality with reliability comparable to the classical visual feedback. Advantages of using a vibrotactile feedback emerged when the visual channel was highly loaded by a complex task. In all experiments, vibrotactile feedback felt, after some training, more natural for both controls and SCI users.

  18. The Art of Giving Online Feedback

    Science.gov (United States)

    Leibold, Nancyruth; Schwarz, Laura Marie

    2015-01-01

    The cultivation of providing online feedback that is positive, effective, and enhances the learning experience is a valuable educator skill. Acquisition of the art of providing feedback is through education, practice, and faculty development. This article provides information about the best practices for delivering online feedback to learners. An…

  19. Effect of tutorial input in addition to augmented feedback on manual dexterity training and its retention.

    Science.gov (United States)

    Wierinck, E; Puttemans, V; van Steenberghe, D

    2006-02-01

    Virtual reality (VR) simulators can be used as tools in manual dexterity training. The visual feedback guides the subject towards proper performance but creates, at the same time, some dependency on this feedback. To overcome this drawback, the effect of adjunct tutorial input on motor learning behaviour was examined. Novice dental students were randomly assigned to one of two training groups or to a non-training control group, given the task of preparing a geometrical class 1 cavity in phantom teeth. The feedback (FB) group trained under augmented visual feedback conditions, provided by the VR system (DentSim). The feedback-plus (FB+) group received, in addition, standardised expert input to enrich the augmented feedback information. The control group, consisting of same year students, did not participate in any training programme. All preparations were evaluated by the VR scoring system. Performance analyses revealed an overall trend towards significant improvement with practice for the training groups. Performance of the FB+ group was most accurate across training. After 1 day and 3 weeks of no practice, both training groups outperformed the control group. After 4 months, however, only the FB+ condition was significantly more accurate than the control group. The same tendency was noted for the transfer tests. Consequently, cavity preparation experience on a VR system under the condition of frequently provided feedback supplemented with expert input was most beneficial to long time learning.

  20. An Internet-Based GIS Platform Providing Data for Visualization and Spatial Analysis of Urbanization in Major Asian and African Cities

    Directory of Open Access Journals (Sweden)

    Hao Gong

    2017-08-01

    Full Text Available Rapid urbanization in developing countries has been observed to be relatively high in the last two decades, especially in the Asian and African regions. Although many researchers have made efforts to improve the understanding of the urbanization trends of various cities in Asia and Africa, the absence of platforms where local stakeholders can visualize and obtain processed urbanization data for their specific needs or analysis, still remains a gap. In this paper, we present an Internet-based GIS platform called MEGA-WEB. The Platform was developed in view of the urban planning and management challenges in developing countries of Asia and Africa due to the limited availability of data resources, effective tools, and proficiency in data analysis. MEGA-WEB provides online access, visualization, spatial analysis, and data sharing services following a mashup framework of the MEGA-WEB Geo Web Services (GWS, with the third-party map services using HTML5/JavaScript techniques. Through the integration of GIS, remote sensing, geo-modelling, and Internet GIS, several indicators for analyzing urbanization are provided in MEGA-WEB to give diverse perspectives on the urbanization of not only the physical land surface condition, but also the relationships of population, energy use, and the environment. The design, architecture, system functions, and uses of MEGA-WEB are discussed in the paper. The MEGA-WEB project is aimed at contributing to sustainable urban development in developing countries of Asia and Africa.

  1. Effects of kinematic vibrotactile feedback on learning to control a virtual prosthetic arm.

    Science.gov (United States)

    Hasson, Christopher J; Manczurowsky, Julia

    2015-03-24

    After a limb is lost a prosthesis can restore function. For maximum utility, prosthetic limbs should accept movement commands and provide force and motion feedback, which can be conveyed with vibrotactile feedback (VIBF). While prior studies have shown that force-based VIBF benefits control, the merits of motion-based VIBF are unclear. Our goal was to clarify the effectiveness of position- and velocity-based VIBF for prosthetic arm control. Healthy adults with normal limb function practiced a goal-directed task with a virtual myoelectric prosthetic arm. A linear resonant actuator on the wrist provided VIBF. Two groups with nine subjects each received amplitude modulated VIBF in addition to visual feedback while practicing the task. In one group, the VIBF was proportional to the virtual arm's position, and in the other group, velocity. A control group of nine subjects received only visual feedback. Subjects practiced for 240 trials, followed by 180 trials with feedback manipulations for the VIBF groups. Performance was characterized by end-point error, movement time, and a composite skill measure that combined these quantities. A second experiment with a new group of five subjects assessed discrimination capabilities between different position- and velocity-based VIBF profiles. With practice all groups improved their skill in controlling the virtual prosthetic arm. Subjects who received additional position- and velocity-based VIBF learned at the same rate as the control group, who received only visual feedback (learning rate time constant: about 40 trials). When visual feedback was subsequently removed leaving only VIBF, performance was no better than with no feedback at all. When VIBF was removed leaving only visual feedback, about half of the participants performed better, instead of worse. The VIBF discrimination tests showed that subjects could detect virtual arm angular position and velocity differences of about 5 deg and 20 deg/s, respectively. Kinematic

  2. Environmental Feedback and Spatial Conditioning

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Poulsen, Esben Skouboe

    2010-01-01

    with structural integrity, where thermal energy flow through the prototype, to be understood as a membrane, can be controlled and the visual transparancy altered. The work shows performance based feedback systems and physical prototype models driven by information streaming, screening and application....

  3. Electroencephalogy (EEG) Feedback in Decision-Making

    Science.gov (United States)

    2015-08-26

    Electroencephalogy ( EEG ) Feedback In Decision- Making The goal of this project is to investigate whether Electroencephalogy ( EEG ) can provide useful...feedback when training rapid decision-making. More specifically, EEG will allow us to provide online feedback about the neural decision processes...Electroencephalogy ( EEG ) Feedback In Decision-Making Report Title The goal of this project is to investigate whether Electroencephalogy ( EEG ) can provide useful

  4. Visual motion imagery neurofeedback based on the hMT+/V5 complex: evidence for a feedback-specific neural circuit involving neocortical and cerebellar regions

    Science.gov (United States)

    Banca, Paula; Sousa, Teresa; Catarina Duarte, Isabel; Castelo-Branco, Miguel

    2015-12-01

    Objective. Current approaches in neurofeedback/brain-computer interface research often focus on identifying, on a subject-by-subject basis, the neural regions that are best suited for self-driven modulation. It is known that the hMT+/V5 complex, an early visual cortical region, is recruited during explicit and implicit motion imagery, in addition to real motion perception. This study tests the feasibility of training healthy volunteers to regulate the level of activation in their hMT+/V5 complex using real-time fMRI neurofeedback and visual motion imagery strategies. Approach. We functionally localized the hMT+/V5 complex to further use as a target region for neurofeedback. An uniform strategy based on motion imagery was used to guide subjects to neuromodulate hMT+/V5. Main results. We found that 15/20 participants achieved successful neurofeedback. This modulation led to the recruitment of a specific network as further assessed by psychophysiological interaction analysis. This specific circuit, including hMT+/V5, putative V6 and medial cerebellum was activated for successful neurofeedback runs. The putamen and anterior insula were recruited for both successful and non-successful runs. Significance. Our findings indicate that hMT+/V5 is a region that can be modulated by focused imagery and that a specific cortico-cerebellar circuit is recruited during visual motion imagery leading to successful neurofeedback. These findings contribute to the debate on the relative potential of extrinsic (sensory) versus intrinsic (default-mode) brain regions in the clinical application of neurofeedback paradigms. This novel circuit might be a good target for future neurofeedback approaches that aim, for example, the training of focused attention in disorders such as ADHD.

  5. Emotional feedback for mobile devices

    CERN Document Server

    Seebode, Julia

    2015-01-01

    This book investigates the functional adequacy as well as the affective impression made by feedback messages on mobile devices. It presents an easily adoptable experimental setup to examine context effects on various feedback messages, and applies it to auditory, tactile and auditory-tactile feedback messages. This approach provides insights into the relationship between the affective impression and functional applicability of these messages as well as an understanding of the influence of unimodal components on the perception of multimodal feedback messages. The developed paradigm can also be extended to investigate other aspects of context and used to investigate feedback messages in modalities other than those presented. The book uses questionnaires implemented on a Smartphone, which can easily be adopted for field studies to broaden the scope even wider. Finally, the book offers guidelines for the design of system feedback.

  6. Offering effective feedback to trainees.

    Science.gov (United States)

    Iskander, Morkos

    2015-01-01

    Effective feedback on performance is an integral part of clinical training. It allows the trainee to critically reflect on their development, as well as enable the teacher to chart progress and detect areas for development. In order to provide effective feedback, we need to take into account the performance itself, but also the setting where feedback is offered, and the expected outcomes of the encounter. As ever, negative feedback remains more difficult to give and receive, and as such requires a greater degree of delicacy to produce a positive result.

  7. Online performance evaluation of motor imagery BCI with augmented-reality virtual hand feedback.

    Science.gov (United States)

    Chin, Zheng Yang; Ang, Kai Keng; Wang, Chuanchu; Guan, Cuntai

    2010-01-01

    The online performance of a motor imagery-based Brain-Computer Interface (MI-BCI) influences its effectiveness and usability in real-world clinical applications such as the restoration of motor control. The online performance depends on factors such as the different feedback techniques and motivation of the subject. This paper investigates the online performance of the MI-BCI with an augmented-reality (AR) 3D virtual hand feedback. The subject experiences the interaction with 3D virtual hands, which have been superimposed onto his real hands and displayed on the computer monitor from a first person point-of-view. While performing motor imagery, he receives continuous visual feedback from the MI-BCI in the form of different degrees of reaching and grasping actions of the 3D virtual hands with other virtual objects. The AR feedback is compared with the conventional horizontal bar feedback on 8 subjects, of whom 7 are BCI-naïve. The subjects found the AR feedback to be more engaging and motivating. Despite the higher mental workload involved in the AR feedback, their online MI-BCI performance compared to the conventional horizontal bar feedback was not affected. The results provide motivation to further develop and refine the AR feedback protocol for MI-BCI.

  8. Development of the Teacher Feedback Observation Scheme: evaluating the quality of feedback in peer groups

    NARCIS (Netherlands)

    Thurlings, Marieke; Vermeulen, Marjan; Kreijns, Karel; Bastiaens, Theo; Stijnen, Sjef

    2018-01-01

    Research suggests that feedback is an essential element in learning. This study focuses on feedback that teachers provide in reciprocal peer groups to improve their performance in the classroom. The Teacher Feedback Observation Scheme (TFOS) was developed to identify feedback patterns, which

  9. A Physics-Based Vibrotactile Feedback Library for Collision Events.

    Science.gov (United States)

    Park, Gunhyuk; Choi, Seungmoon

    2017-01-01

    We present PhysVib: a software solution on the mobile platform extending an open-source physics engine in a multi-rate rendering architecture for automatic vibrotactile feedback upon collision events. PhysVib runs concurrently with a physics engine at a low update rate and generates vibrotactile feedback commands at a high update rate based on the simulation results of the physics engine using an exponentially-decaying sinusoidal model. We demonstrate through a user study that this vibration model is more appropriate to our purpose in terms of perceptual quality than more complex models based on sound synthesis. We also evaluated the perceptual performance of PhysVib by comparing eight vibrotactile rendering methods. Experimental results suggested that PhysVib enables more realistic vibrotactile feedback than the other methods as to perceived similarity to the visual events. PhysVib is an effective solution for providing physically plausible vibrotactile responses while reducing application development time to great extent.

  10. Real-Time Performance Feedback for the Manual Control of Spacecraft

    Science.gov (United States)

    Karasinski, John Austin

    Real-time performance metrics were developed to quantify workload, situational awareness, and manual task performance for use as visual feedback to pilots of aerospace vehicles. Results from prior lunar lander experiments with variable levels of automation were replicated and extended to provide insights for the development of real-time metrics. Increased levels of automation resulted in increased flight performance, lower workload, and increased situational awareness. Automated Speech Recognition (ASR) was employed to detect verbal callouts as a limited measure of subjects' situational awareness. A one-dimensional manual tracking task and simple instructor-model visual feedback scheme was developed. This feedback was indicated to the operator by changing the color of a guidance element on the primary flight display, similar to how a flight instructor points out elements of a display to a student pilot. Experiments showed that for this low-complexity task, visual feedback did not change subject performance, but did increase the subjects' measured workload. Insights gained from these experiments were applied to a Simplified Aid for EVA Rescue (SAFER) inspection task. The effects of variations of an instructor-model performance-feedback strategy on human performance in a novel SAFER inspection task were investigated. Real-time feedback was found to have a statistically significant effect of improving subject performance and decreasing workload in this complicated four degree of freedom manual control task with two secondary tasks.

  11. Finding the best visualization of an ontology

    DEFF Research Database (Denmark)

    Fabritius, Christina Valentin; Madsen, Nadia Lyngaa; Clausen, Jens

    2004-01-01

    An ontology is a classification model for a given domain. In information retrieval ontologies are used to perform broad searches. An ontology can be visualized as nodes and edges. Each node represents an element and each edge a relation between a parent and a child element. Working with an ontology...... becomes easier with a visual representation. An idea is to use the expressive power that a 3D representation to provide visualization for the user. In this paper we propose a new method for positioning the elements of the visualized concept lattice in the 3D world based on Operations Research (OR) methods....... One method uses a discrete location model to create an initial solution and we propose heuristic methods to further improve the visual result. We evaluate the visual results according to our success criteria and the feedback from users. Running times of the heuristic indicate that an improved version...

  12. Effects of acoustic feedback training in elite-standard Para-Rowing.

    Science.gov (United States)

    Schaffert, Nina; Mattes, Klaus

    2015-01-01

    Assessment and feedback devices have been regularly used in technique training in high-performance sports. Biomechanical analysis is mainly visually based and so can exclude athletes with visual impairments. The aim of this study was to examine the effects of auditory feedback on mean boat speed during on-water training of visually impaired athletes. The German National Para-Rowing team (six athletes, mean ± s, age 34.8 ± 10.6 years, body mass 76.5 ± 13.5 kg, stature 179.3 ± 8.6 cm) participated in the study. Kinematics included boat acceleration and distance travelled, collected with Sofirow at two intensities of training. The boat acceleration-time traces were converted online into acoustic feedback and presented via speakers during rowing (sections with and without alternately). Repeated-measures within-participant factorial ANOVA showed greater boat speed with acoustic feedback than baseline (0.08 ± 0.01 m·s(-1)). The time structure of rowing cycles was improved (extended time of positive acceleration). Questioning of athletes showed acoustic feedback to be a supportive training aid as it provided important functional information about the boat motion independent of vision. It gave access for visually impaired athletes to biomechanical analysis via auditory information. The concept for adaptive athletes has been successfully integrated into the preparation for the Para-Rowing World Championships and Paralympics.

  13. Visual feedback navigation for cable tracking by autonomous underwater vehicles; Jiritsugata kaichu robot no gazo shori ni motozuku cable jido tsuiju

    Energy Technology Data Exchange (ETDEWEB)

    Takai, M.; Ura, T. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Balasuriya, B.; Lam, W. [The University of Tokyo, Tokyo (Japan); Kuroda, Y. [Meiji Univ., Tokyo (Japan)

    1997-08-01

    A vision processing unit was introduced into autonomous underwater vehicles (AUV) to judge the visual situation and to construct an environmental observation platform that can collect wide-range and high-precision measurement data. The cable optionally installed at the bottom of the sea was recognized by vision processing to propose automatic tracking technique. An estimator that compensates for the hough conversion or time delay and a PSA controller that is used as a target value set mechanism or lower-level controller were introduced as the factor technology required for automatic tracking. The feature of the automatic tracking is that a general-purpose platform which can observe the prescribed range environmentally in high precision and density can be constructed because the observation range required by the observer can be prescribed near the sea-bottom surface using a cable. The verification result off Omi Hachiman at Lake Biwa showed that AUV can be used for the high-precision environmental survey in the range prescribed near the sea-bottom surface using a cable. 8 refs., 8 figs., 1 tab.

  14. The effects of augmented visual feedback during balance training in Parkinson’s disease: study design of a randomized clinical trial

    NARCIS (Netherlands)

    van den Heuvel, M.R.C.; van Wegen, E.E.H.; de Goede, C.J.T.; Burgers-Pots, I.A.L.; Beek, P.J.; Daffertshofer, A.; Kwakkel, G.

    2013-01-01

    Background: Patients with Parkinson's disease often suffer from reduced mobility due to impaired postural control. Balance exercises form an integral part of rehabilitative therapy but the effectiveness of existing interventions is limited. Recent technological advances allow for providing enhanced

  15. Visualizing uncertain underground information for urban management: Poster presented at the Working with Uncertainty Workshop (IEEE VisWeek 2011), October 24, Providence, Rhode Island

    OpenAIRE

    Dummer, Martin; Krämer, Michel; Ruppert, Tobias; Kohlhammer, Jörn

    2011-01-01

    We present approaches for visualizing uncertainty in an application context through techniques for the visualization of uncertainty. We also describe methods for the reduction of the complexity of the visualization to avoid cognitive overload. Uncertainty in both natural and man-made structures under ground is thus communicated to the user in an appropriate, non threatening manner. The methods were evaluated during an end-user workshop of the research project DeepCity3D. The results of this w...

  16. Feedback, Incentives and Peer Effects

    DEFF Research Database (Denmark)

    Eriksson, Tor Viking; Poulsen, Anders; Villeval, Marie Claire

    . The pay schemes are a piece rate payment scheme and a winner takes-all tournament. We find that the principal should not provide any information on relative  performance, regardless of the pay scheme used, since feedback does not improve performance. Indeed, we do not find evidence of positive peer...... effects in the piece-rate pay scheme. In both pay schemes, interim feedback generates negative quality peer effects on the less able performers. We find however evidence of positive peer effects in the tournament scheme since the underdogs almost never quit the competition even when lagging significantly......This paper experimentally investigates the impact of different pay and relative performance information policies on employee effort. We explore three information policies: No feedback, feedback given halfway through the production period, and continuously updated feedback about relative performance...

  17. Effectiveness of Feedback in First Year Physics

    DEFF Research Database (Denmark)

    Bearden, Ian; Voigt, Karen A; Mathiasen, Helle

    How can we provide better and more effective feedback to our students? How can we encourage students to use feedback effectively? We will present results of a study of first year physics students addressing these questions and comparing the effectiveness of written and screencast feedback....

  18. Mass production of individual feedback

    OpenAIRE

    Heaney, David

    2006-01-01

    Learning to program is intrinsically difficult. In addition there is a trend towards increased student diversity and larger class sizes. Student diversity increases the need for individual attention for each student, while increased class sizes decreases the amount of time a lecturer has to provide this attention. This thesis investigates an approach to help provide each student with detailed individual feedback. This feedback is important where individual attention is lacking. We used tw...

  19. Assessment of clinical feedback given to medical students via an electronic feedback system.

    Science.gov (United States)

    Shaughness, Gabrielle; Georgoff, Patrick E; Sandhu, Gurjit; Leininger, Lisa; Nikolian, Vahagn C; Reddy, Rishindra; Hughes, David T

    2017-10-01

    The feedback medical students receive during clinical rotations, traditionally verbal and not formally captured, plays a critical role in student development. This study evaluates written daily feedback given to students through a novel web-based feedback system. A Minute Feedback System was used to collect feedback given to medical students during their surgery clerkship from May 2015-April 2016. Using qualitative content analysis, feedback comments were categorized as: encouraging, corrective, specific, and nonspecific. Effective feedback was a combination of specific and either corrective or encouraging feedback; ineffective feedback contained only nonspecific comments; mediocre feedback contained elements of both effective and ineffective comments. 3191 feedback requests were sent by medical students and 2029 faculty/resident feedback responses were received. The overall response rate was 62%. Nonspecific feedback comprised 80% of faculty, 83% of senior resident, and 78% of junior resident comments. Specific feedback was given by only 35% of faculty, 17% of senior residents, and 26% of junior residents. Faculty provided Effective feedback in only 16% of comments, senior residents 8%, and junior residents 17%. Mediocre feedback comprised 13% of faculty, 9% of senior resident, and 7% of junior resident comments. Ineffective feedback comprised 67% of all feedback: 60% of faculty, 72% of senior resident, and 68% of junior resident feedback. The majority of resident and faculty feedback to medical students using an electronic, email-based application during their surgery clerkship was nonspecific and encouraging and therefore of limited effectiveness. This presents an opportunity for resident/faculty development and education regarding optimal feedback techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. The effect of force feedback on student reasoning about gravity, mass, force and motion

    Science.gov (United States)

    Bussell, Linda

    The purpose of this study was to examine whether force feedback within a computer simulation had an effect on reasoning by fifth grade students about gravity, mass, force, and motion, concepts which can be difficult for learners to grasp. Few studies have been done on cognitive learning and haptic feedback, particularly with young learners, but there is an extensive base of literature on children's conceptions of science and a number of studies focus specifically on children's conceptions of force and motion. This case study used a computer-based paddleball simulation with guided inquiry as the primary stimulus. Within the simulation, the learner could adjust the mass of the ball and the gravitational force. The experimental group used the simulation with visual and force feedback; the control group used the simulation with visual feedback but without force feedback. The proposition was that there would be differences in reasoning between the experimental and control groups, with force feedback being helpful with concepts that are more obvious when felt. Participants were 34 fifth-grade students from three schools. Students completed a modal (visual, auditory, and haptic) learning preference assessment and a pretest. The sessions, including participant experimentation and interviews, were audio recorded and observed. The interviews were followed by a written posttest. These data were analyzed to determine whether there were differences based on treatment, learning style, demographics, prior gaming experience, force feedback experience, or prior knowledge. Work with the simulation, regardless of group, was found to increase students' understanding of key concepts. The experimental group appeared to benefit from the supplementary help that force feedback provided. Those in the experimental group scored higher on the posttest than those in the control group. The greatest difference between mean group scores was on a question concerning the effects of increased

  1. Alterations in Neural Control of Constant Isometric Contraction with the Size of Error Feedback.

    Directory of Open Access Journals (Sweden)

    Ing-Shiou Hwang

    Full Text Available Discharge patterns from a population of motor units (MUs were estimated with multi-channel surface electromyogram and signal processing techniques to investigate parametric differences in low-frequency force fluctuations, MU discharges, and force-discharge relation during static force-tracking with varying sizes of execution error presented via visual feedback. Fourteen healthy adults produced isometric force at 10% of maximal voluntary contraction through index abduction under three visual conditions that scaled execution errors with different amplification factors. Error-augmentation feedback that used a high amplification factor (HAF to potentiate visualized error size resulted in higher sample entropy, mean frequency, ratio of high-frequency components, and spectral dispersion of force fluctuations than those of error-reducing feedback using a low amplification factor (LAF. In the HAF condition, MUs with relatively high recruitment thresholds in the dorsal interosseous muscle exhibited a larger coefficient of variation for inter-spike intervals and a greater spectral peak of the pooled MU coherence at 13-35 Hz than did those in the LAF condition. Manipulation of the size of error feedback altered the force-discharge relation, which was characterized with non-linear approaches such as mutual information and cross sample entropy. The association of force fluctuations and global discharge trace decreased with increasing error amplification factor. Our findings provide direct neurophysiological evidence that favors motor training using error-augmentation feedback. Amplification of the visualized error size of visual feedback could enrich force gradation strategies during static force-tracking, pertaining to selective increases in the discharge variability of higher-threshold MUs that receive greater common oscillatory inputs in the β-band.

  2. Alterations in Neural Control of Constant Isometric Contraction with the Size of Error Feedback.

    Science.gov (United States)

    Hwang, Ing-Shiou; Lin, Yen-Ting; Huang, Wei-Min; Yang, Zong-Ru; Hu, Chia-Ling; Chen, Yi-Ching

    2017-01-01

    Discharge patterns from a population of motor units (MUs) were estimated with multi-channel surface electromyogram and signal processing techniques to investigate parametric differences in low-frequency force fluctuations, MU discharges, and force-discharge relation during static force-tracking with varying sizes of execution error presented via visual feedback. Fourteen healthy adults produced isometric force at 10% of maximal voluntary contraction through index abduction under three visual conditions that scaled execution errors with different amplification factors. Error-augmentation feedback that used a high amplification factor (HAF) to potentiate visualized error size resulted in higher sample entropy, mean frequency, ratio of high-frequency components, and spectral dispersion of force fluctuations than those of error-reducing feedback using a low amplification factor (LAF). In the HAF condition, MUs with relatively high recruitment thresholds in the dorsal interosseous muscle exhibited a larger coefficient of variation for inter-spike intervals and a greater spectral peak of the pooled MU coherence at 13-35 Hz than did those in the LAF condition. Manipulation of the size of error feedback altered the force-discharge relation, which was characterized with non-linear approaches such as mutual information and cross sample entropy. The association of force fluctuations and global discharge trace decreased with increasing error amplification factor. Our findings provide direct neurophysiological evidence that favors motor training using error-augmentation feedback. Amplification of the visualized error size of visual feedback could enrich force gradation strategies during static force-tracking, pertaining to selective increases in the discharge variability of higher-threshold MUs that receive greater common oscillatory inputs in the β-band.

  3. Polarization feedback laser stabilization

    Science.gov (United States)

    Esherick, P.; Owyoung, A.

    1987-09-28

    A system for locking two Nd:YAG laser oscillators includes an optical path for feeding the output of one laser into the other with different polarizations. Elliptical polarization is incorporated into the optical path so that the change in polarization that occurs when the frequencies coincide may be detected to provide a feedback signal to control one laser relative to the other. 4 figs.

  4. Comprehensive feedback on trainee surgeons' non-technical skills

    DEFF Research Database (Denmark)

    Spanager, Lene; Dieckmann, Peter; Beier-Holgersen, Randi

    2015-01-01

    OBJECTIVE: This study aimed to explore the content of conversations, feedback style, and perceived usefulness of feedback to trainee surgeons when conversations were stimulated by a tool for assessing surgeons' non-technical skills. METHODS: Trainee surgeons and their supervisors used the Non......-Technical Skills for Surgeons in Denmark tool to stimulate feedback conversations. Audio recordings of post-operation feedback conversations were collected. Trainees and supervisors provided questionnaire responses on the usefulness and comprehensiveness of the feedback. The feedback conversations were...

  5. Effects of Varied Enhancement Strategies (Chunking, Feedback, Gaming) in Complementing Animated Instruction in Facilitating Different Types of Learning Objectives

    Science.gov (United States)

    Munyofu, Mine

    2008-01-01

    The purpose of this study was to examine the instructional effectiveness of different levels of chunking (simple visual/text and complex visual/text), different forms of feedback (item-by-item feedback, end-of-test feedback and no feedback), and use of instructional gaming (game and no game) in complementing animated programmed instruction on a…

  6. Feedback as real-time constructions

    DEFF Research Database (Denmark)

    Keiding, Tina Bering; Qvortrup, Ane

    2014-01-01

    This article offers a re-description of feedback and the significance of time in feedback constructions based on systems theory. It describes feedback as internal, real-time constructions in a learning system. From this perspective, feedback is neither immediate nor delayed, but occurs in the very...... instant it takes place. This article argues for a clear distinction between the timing of communicative events, such as responses that are provided as help for feedback constructions, and the feedback construction itself as an event in a psychic system. Although feedback is described as an internal......, system-relative construction, different teaching environments offer diverse conditions for feedback constructions. The final section of this article explores this idea with the help of examples from both synchronous oral interaction and asynchronous text-based interaction mediated by digital media....

  7. Feedback as real-time constructions

    DEFF Research Database (Denmark)

    Keiding, Tina Bering; Qvortrup, Ane

    2014-01-01

    The article offers a re-description of feedback and the significance of time in feedback constructions based on systems theory. It describes feedback as internal, real-time constructions in a learning system. From this perspective, feedback is neither immediate nor delayed, but occurs in the very...... instant it takes place. This article argues for a clear distinction between the timing of communicative events, such as responses that are provided as help for feedback constructions, and the feedback construction itself as an event in a psychic system. Although feedback is described as an internal......, system-relative construction, different teaching environments offer diverse conditions for feedback constructions. The final section of this article explores this idea with the help of examples from both synchronous, oral interaction and asynchronous, text-based interaction mediated by digital media....

  8. Decoding sound and imagery content in early visual cortex.

    Science.gov (United States)

    Vetter, Petra; Smith, Fraser W; Muckli, Lars

    2014-06-02

    Human early visual cortex was traditionally thought to process simple visual features such as orientation, contrast, and spatial frequency via feedforward input from the lateral geniculate nucleus (e.g., [1]). However, the role of nonretinal influence on early visual cortex is so far insufficiently investigated despite much evidence that feedback connections greatly outnumber feedforward connections [2-5]. Here, we explored in five fMRI experiments how information originating from audition and imagery affects the brain activity patterns in early visual cortex in the absence of any feedforward visual stimulation. We show that category-specific information from both complex natural sounds and imagery can be read out from early visual cortex activity in blindfolded participants. The coding of nonretinal information in the activity patterns of early visual cortex is common across actual auditory perception and imagery and may be mediated by higher-level multisensory areas. Furthermore, this coding is robust to mild manipulations of attention and working memory but affected by orthogonal, cognitively demanding visuospatial processing. Crucially, the information fed down to early visual cortex is category specific and generalizes to sound exemplars of the same category, providing evidence for abstract information feedback rather than precise pictorial feedback. Our results suggest that early visual cortex receives nonretinal input from other brain areas when it is generated by auditory perception and/or imagery, and this input carries common abstract information. Our findings are compatible with feedback of predictive information to the earliest visual input level (e.g., [6]), in line with predictive coding models [7-10]. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Auditory display as feedback for a novel eye-tracking system for sterile operating room interaction.

    Science.gov (United States)

    Black, David; Unger, Michael; Fischer, Nele; Kikinis, Ron; Hahn, Horst; Neumuth, Thomas; Glaser, Bernhard

    2018-01-01

    The growing number of technical systems in the operating room has increased attention on developing touchless interaction methods for sterile conditions. However, touchless interaction paradigms lack the tactile feedback found in common input devices such as mice and keyboards. We propose a novel touchless eye-tracking interaction system with auditory display as a feedback method for completing typical operating room tasks. Auditory display provides feedback concerning the selected input into the eye-tracking system as well as a confirmation of the system response. An eye-tracking system with a novel auditory display using both earcons and parameter-mapping sonification was developed to allow touchless interaction for six typical scrub nurse tasks. An evaluation with novice participants compared auditory display with visual display with respect to reaction time and a series of subjective measures. When using auditory display to substitute for the lost tactile feedback during eye-tracking interaction, participants exhibit reduced reaction time compared to using visual-only display. In addition, the auditory feedback led to lower subjective workload and higher usefulness and system acceptance ratings. Due to the absence of tactile feedback for eye-tracking and other touchless interaction methods, auditory display is shown to be a useful and necessary addition to new interaction concepts for the sterile operating room, reducing reaction times while improving subjective measures, including usefulness, user satisfaction, and cognitive workload.

  10. Data visualization

    CERN Document Server

    Azzam, Tarek

    2013-01-01

    Do you communicate data and information to stakeholders? In Part 1, we introduce recent developments in the quantitative and qualitative data visualization field and provide a historical perspective on data visualization, its potential role in evaluation practice, and future directions. Part 2 delivers concrete suggestions for optimally using data visualization in evaluation, as well as suggestions for best practices in data visualization design. It focuses on specific quantitative and qualitative data visualization approaches that include data dashboards, graphic recording, and geographic information systems (GIS). Readers will get a step-by-step process for designing an effective data dashboard system for programs and organizations, and various suggestions to improve their utility.

  11. Direct Visualization of RNA-DNA Primer Removal from Okazaki Fragments Provides Support for Flap Cleavage and Exonucleolytic Pathways in Eukaryotic Cells.

    Science.gov (United States)

    Liu, Bochao; Hu, Jiazhi; Wang, Jingna; Kong, Daochun

    2017-03-24

    During DNA replication in eukaryotic cells, short single-stranded DNA segments known as Okazaki fragments are first synthesized on the lagging strand. The Okazaki fragments originate from ∼35-nucleotide-long RNA-DNA primers. After Okazaki fragment synthesis, these primers must be removed to allow fragment joining into a continuous lagging strand. To date, the models of enzymatic machinery that removes the RNA-DNA primers have come almost exclusively from biochemical reconstitution studies and some genetic interaction assays, and there is little direct evidence to confirm these models. One obstacle to elucidating Okazaki fragment processing has been the lack of methods that can directly examine primer removal in vivo In this study, we developed an electron microscopy assay that can visualize nucleotide flap structures on DNA replication forks in fission yeast ( Schizosaccharomyces pombe ). With this assay, we first demonstrated the generation of flap structures during Okazaki fragment processing in vivo The mean and median lengths of the flaps in wild-type cells were ∼51 and ∼41 nucleotides, respectively. We also used yeast mutants to investigate the impact of deleting key DNA replication nucleases on these flap structures. Our results provided direct in vivo evidence for a previously proposed flap cleavage pathway and the critical function of Dna2 and Fen1 in cleaving these flaps. In addition, we found evidence for another previously proposed exonucleolytic pathway involving RNA-DNA primer digestion by exonucleases RNase H2 and Exo1. Taken together, our observations suggest a dual mechanism for Okazaki fragment maturation in lagging strand synthesis and establish a new strategy for interrogation of this fascinating process. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Visual Analogue Scale for Anxiety and Amsterdam Preoperative Anxiety Scale Provide a Simple and Reliable Measurement of Preoperative Anxiety in Patients Undergoing Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    Joaquín Hernández-Palazón

    2015-03-01

    Full Text Available Background: Anxiety is an emotional state characterized by apprehension and fear resulting from anticipation of a threatening event. Objectives: The present study aimed to analyze the incidence and level of preoperative anxiety in the patients scheduled for cardiac surgery by using a Visual Analogue Scale for Anxiety (VAS-A and Amsterdam Preoperative Anxiety and Information Scale (APAIS and to identify the influencing clinical factors. Patients and Methods: This prospective, longitudinal study was performed on 300 cardiac surgery patients in a single university hospital. The patients were assessed regarding their preoperative anxiety level using VAS-A, APAIS, and a set of specific anxiety-related questions. Their demographic features as well as their anesthetic and surgical characteristics (ASA physical status, EuroSCORE, preoperative Length of Stay (LoS, and surgical history were recorded, as well. Then, one-way ANOVA and t-test were applied along with odds ratio for risk assessment. Results: According to the results, 94% of the patients presented preoperative anxiety, with 37% developing high anxiety (VAS-A ≥ 7. Preoperative LoS > 2 days was the only significant risk factor for preoperative anxiety (odds ratio = 2.5, CI 95%, 1.3 - 5.1, P = 0.009. Besides, a positive correlation was found between anxiety level (APAISa and requirement of knowledge (APAISk. APAISa and APAISk scores were greater for surgery than for anesthesia. Moreover, the results showed that the most common anxieties resulted from the operation, waiting for surgery, not knowing what is happening, postoperative pain, awareness during anesthesia, and not awakening from anesthesia. Conclusions: APAIS and VAS-A provided a quantitative assessment of anxiety and a specific qualitative questionnaire for preoperative anxiety in cardiac surgery. According to the results, preoperative LoS > 2 days and lack of information related to surgery were the risk factors for high anxiety levels.

  13. Prefrontal Neurons Represent Motion Signals from Across the Visual Field But for Memory-Guided Comparisons Depend on Neurons Providing These Signals.

    Science.gov (United States)

    Wimmer, Klaus; Spinelli, Philip; Pasternak, Tatiana

    2016-09-07

    Visual decisions often involve comparisons of sequential stimuli that can appear at any location in the visual field. The lateral prefrontal cortex (LPFC) in nonhuman primates, shown to play an important role in such comparisons, receives information about contralateral stimuli directly from sensory neurons in the same hemisphere, and about ipsilateral stimuli indirectly from neurons in the opposite hemisphere. This asymmetry of sensory inputs into the LPFC poses the question of whether and how its neurons incorporate sensory information arriving from the two hemispheres during memory-guided comparisons of visual motion. We found that, although responses of individual LPFC neurons to contralateral stimuli were stronger and emerged 40 ms earlier, they carried remarkably similar signals about motion direction in the two hemifields, with comparable direction selectivity and similar direction preferences. This similarity was also apparent around the time of the comparison between the current and remembered stimulus because both ipsilateral and contralateral responses showed similar signals reflecting the remembered direction. However, despite availability in the LPFC of motion information from across the visual field, these "comparison effects" required for the comparison stimuli to appear at the same retinal location. This strict dependence on spatial overlap of the comparison stimuli suggests participation of neurons with localized receptive fields in the comparison process. These results suggest that while LPFC incorporates many key aspects of the information arriving from sensory neurons residing in opposite hemispheres, it continues relying on the interactions with these neurons at the time of generating signals leading to successful perceptual decisions. Visual decisions often involve comparisons of sequential visual motion that can appear at any location in the visual field. We show that during such comparisons, the lateral prefrontal cortex (LPFC) contains

  14. The Two Visual Systems Hypothesis: new challenges and insights from visual form agnosic patient DF

    Directory of Open Access Journals (Sweden)

    Robert Leslie Whitwell

    2014-12-01

    Full Text Available Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision to adjust the configuration of her grasping hand to the geometry of a goal object. This striking dissociation between perception and action in DF provided a key piece of evidence for the formulation of Goodale and Milner’s Two Visual Systems Hypothesis (TVSH. According to the TVSH, the ventral stream plays a critical role in constructing our visual percepts, whereas the dorsal stream mediates the visual control of action, such as visually guided grasping. In this review, we discuss recent studies of DF that provide new insights into the functional organization of the dorsal and ventral streams. We confirm recent evidence that DF has dorsal as well as ventral brain damage – and that her dorsal-stream lesions and surrounding atrophy have increased in size since her first published brain scan. We argue that the damage to DF’s dorsal stream explains her deficits in directing actions at targets in the periphery. We then focus on DF’s ability to accurately adjust her in-flight hand aperture to changes in the width of goal objects (grip scaling whose dimensions she cannot explicitly report. An examination of several studies of DF’s grip scaling under natural conditions reveals a modest though significant deficit. Importantly, however, she continues to show a robust dissociation between form vision for perception and form vision for action. We also review recent studies that explore the role of online visual feedback and terminal haptic feedback in the programming and control of her grasping. These studies make it clear that DF is no more reliant on visual or haptic feedback than are neurologically-intact individuals. In short, we argue that her ability to grasp objects depends on visual feedforward processing carried out by visuomotor networks in her dorsal stream that function in the much the same way as they do in neurologically

  15. Immediate Feedback on Accuracy and Performance: The Effects of Wireless Technology on Food Safety Tracking at a Distribution Center

    Science.gov (United States)

    Goomas, David T.

    2012-01-01

    The effects of wireless ring scanners, which provided immediate auditory and visual feedback, were evaluated to increase the performance and accuracy of order selectors at a meat distribution center. The scanners not only increased performance and accuracy compared to paper pick sheets, but were also instrumental in immediate and accurate data…

  16. Skriftlig feedback i engelskundervisningen

    DEFF Research Database (Denmark)

    Kjærgaard, Hanne Wacher

    2017-01-01

    The article describes useful feedback strategies in language teaching and describes the feedback practices of lower-seconday teachers in Denmark. The article is aimed at language teahcers in secondary schools.......The article describes useful feedback strategies in language teaching and describes the feedback practices of lower-seconday teachers in Denmark. The article is aimed at language teahcers in secondary schools....

  17. Visual display aid for orbital maneuvering - Design considerations

    Science.gov (United States)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1993-01-01

    This paper describes the development of an interactive proximity operations planning system that allows on-site planning of fuel-efficient multiburn maneuvers in a potential multispacecraft environment. Although this display system most directly assists planning by providing visual feedback to aid visualization of the trajectories and constraints, its most significant features include: (1) the use of an 'inverse dynamics' algorithm that removes control nonlinearities facing the operator, and (2) a trajectory planning technique that separates, through a 'geometric spreadsheet', the normally coupled complex problems of planning orbital maneuvers and allows solution by an iterative sequence of simple independent actions. The visual feedback of trajectory shapes and operational constraints, provided by user-transparent and continuously active background computations, allows the operator to make fast, iterative design changes that rapidly converge to fuel-efficient solutions. The planning tool provides an example of operator-assisted optimization of nonlinear cost functions.

  18. Force feedback system using magneto-rheological fluids for telerobotic surgery

    Science.gov (United States)

    Neelakantan, Vijay A.; Washington, Gregory N.; Wolf, Randall K.

    2002-07-01

    Force feedback is a new technology that has great potential in human-machine interfaces. While guiding the end effector of a robot through an environment using a hand-held actuator, force feedback is needed to make the user feel the environment conditions like stiffness along which the end effector moves. This along with the already available visual feedback will allow the user to guide the robot exactly along the path that he or she intends thereby enhancing the performance. Easily controllable actuators that give quick response at the user end are needed here. This paper demonstrates the effectiveness of MR fluid devices in such force feedback applications. The force-feedback experiment includes a simple setup that depicts a typical situation wherein a user controls the movement of an external linear hydraulic actuator using a MR sponge damper. Force and displacement sensors sense the environment conditions along which the end effector of the hydraulic actuator moves. This information is then used to control the MR damper to provide appropriate force feedback to the user. The setup is tested with different environments like springs with various stiffnesses and for extreme cases with mechanical stops thereby demonstrating the flexibility in using MR sponge dampers for various force feedback applications.

  19. Designing Crowdcritique Systems for Formative Feedback

    Science.gov (United States)

    Easterday, Matthew W.; Rees Lewis, Daniel; Gerber, Elizabeth M.

    2017-01-01

    Intelligent tutors based on expert systems often struggle to provide formative feedback on complex, ill-defined problems where answers are unknown. Hybrid crowdsourcing systems that combine the intelligence of multiple novices in face-to-face settings might provide an alternate approach for providing intelligent formative feedback. The purpose of…

  20. Teacher feedback in the classroom. Analyzing and developing teachers' feedback behavior in secondary education

    NARCIS (Netherlands)

    Voerman, A.

    2014-01-01

    Providing feedback is one of the most influential means of teachers to enhance student learning. In this dissertation, we first focused on what is known from research about effective (i.e. learning-enhancing) feedback. Effective feedback, mostly studied from a cognitive psychologist point of view,

  1. Restoring natural sensory feedback in real-time bidirectional hand prostheses

    DEFF Research Database (Denmark)

    Raspopovic, Stanisa; Capogrosso, Marco; Petrini, Francesco Maria

    2014-01-01

    Hand loss is a highly disabling event that markedly affects the quality of life. To achieve a close to natural replacement for the lost hand, the user should be provided with the rich sensations that we naturally perceive when grasping or manipulating an object. Ideal bidirectional hand prostheses...... feedback. We show that by stimulating the median and ulnar nerve fascicles using transversal multichannel intrafascicular electrodes, according to the information provided by the artificial sensors from a hand prosthesis, physiologically appropriate (near-natural) sensory information can be provided...... to an amputee during the real-time decoding of different grasping tasks to control a dexterous hand prosthesis. This feedback enabled the participant to effectively modulate the grasping force of the prosthesis with no visual or auditory feedback. Three different force levels were distinguished and consistently...

  2. The Feedback Tango: An Integrative Review and Analysis of the Content of the Teacher-Learner Feedback Exchange.

    Science.gov (United States)

    Bing-You, Robert; Varaklis, Kalli; Hayes, Victoria; Trowbridge, Robert; Kemp, Heather; McKelvy, Dina

    2017-10-03

    To conduct an integrative review and analysis of the literature on the content of feedback to learners in medical education. Following completion of a scoping review in 2016, the authors analyzed a subset of articles published through 2015 describing the analysis of feedback exchange content in various contexts: audiotapes, clinical examination, feedback cards, multisource feedback, videotapes, and written feedback. Two reviewers extracted data from these articles and identified common themes. Of the 51 included articles, about half (49%) were published since 2011. Most involved medical students (43%) or residents (43%). A leniency bias was noted in many (37%), as there was frequently reluctance to provide constructive feedback. More than one-quarter (29%) indicated the feedback was low in quality (e.g., too general, limited amount, no action plans). Some (16%) indicated faculty dominated conversations, did not use feedback forms appropriately, or provided inadequate feedback, even after training. Multiple feedback tools were used, with some articles (14%) describing varying degrees of use, completion, or legibility. Some articles (14%) noted the impact of the gender of the feedback provider or learner. The findings reveal that the exchange of feedback is troubled by low-quality feedback, leniency bias, faculty deficient in feedback competencies, challenges with multiple feedback tools, and gender impacts. Using the tango dance form as a metaphor for this dynamic partnership, the authors recommend ways to improve feedback for teachers and learners willing to partner with each other and engage in the complexities of the feedback exchange.

  3. Tactile feedback improves auditory spatial localization.

    Science.gov (United States)

    Gori, Monica; Vercillo, Tiziana; Sandini, Giulio; Burr, David

    2014-01-01

    Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gori et al., 2014). To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback, or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject's forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial. The no feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

  4. Sensory feedback by peripheral nerve stimulation improves task performance in individuals with upper limb loss using a myoelectric prosthesis

    Science.gov (United States)

    Schiefer, Matthew; Tan, Daniel; Sidek, Steven M.; Tyler, Dustin J.

    2016-02-01

    Objective. Tactile feedback is critical to grip and object manipulation. Its absence results in reliance on visual and auditory cues. Our objective was to assess the effect of sensory feedback on task performance in individuals with limb loss. Approach. Stimulation of the peripheral nerves using implanted cuff electrodes provided two subjects with sensory feedback with intensity proportional to forces on the thumb, index, and middle fingers of their prosthetic hand during object manipulation. Both subjects perceived the sensation on their phantom hand at locations corresponding to the locations of the forces on the prosthetic hand. A bend sensor measured prosthetic hand span. Hand span modulated the intensity of sensory feedback perceived on the thenar eminence for subject 1 and the middle finger for subject 2. We performed three functional tests with the blindfolded subjects. First, the subject tried to determine whether or not a wooden block had been placed in his prosthetic hand. Second, the subject had to locate and remove magnetic blocks from a metal table. Third, the subject performed the Southampton Hand Assessment Procedure (SHAP). We also measured the subject’s sense of embodiment with a survey and his self-confidence. Main results. Blindfolded performance with sensory feedback was similar to sighted performance in the wooden block and magnetic block tasks. Performance on the SHAP, a measure of hand mechanical function and control, was similar with and without sensory feedback. An embodiment survey showed an improved sense of integration of the prosthesis in self body image with sensory feedback. Significance. Sensory feedback by peripheral nerve stimulation improved object discrimination and manipulation, embodiment, and confidence. With both forms of feedback, the blindfolded subjects tended toward results obtained with visual feedback.

  5. Factors Influencing Spanish Instructors' In-Class Feedback Decisions

    Science.gov (United States)

    Gurzynski-Weiss, Laura

    2016-01-01

    While oral corrective feedback is a principal focus in second language acquisition research, most studies examine feedback once it has been provided. Investigating how instructors make in-class feedback decisions has not been thoroughly explored, despite the fact that classroom feedback occurs at the discretion of the individual language…

  6. Hydrogen Infrastructure Market Readiness: Opportunities and Potential for Near-term Cost Reductions; Proceedings of the Hydrogen Infrastructure Market Readiness Workshop and Summary of Feedback Provided through the Hydrogen Station Cost Calculator

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, M. W.; Steward, D.; Penev, M.; McQueen, S.; Jaffe, S.; Talon, C.

    2012-08-01

    Recent progress with fuel cell electric vehicles (FCEVs) has focused attention on hydrogen infrastructure as a critical commercialization barrier. With major automakers focused on 2015 as a target timeframe for global FCEV commercialization, the window of opportunity is short for establishing a sufficient network of hydrogen stations to support large-volume vehicle deployments. This report describes expert feedback on the market readiness of hydrogen infrastructure technology from two activities.

  7. Prototype tactile feedback system for examination by skin touch.

    Science.gov (United States)

    Lee, O; Lee, K; Oh, C; Kim, K; Kim, M

    2014-08-01

    Diagnosis of conditions such as psoriasis and atopic dermatitis, in the case of induration, involves palpating the infected area via hands and then selecting a ratings score. However, the score is determined based on the tester's experience and standards, making it subjective. To provide tactile feedback on the skin, we developed a prototype tactile feedback system to simulate skin wrinkles with PHANToM OMNI. To provide the user with tactile feedback on skin wrinkles, a visual and haptic Augmented Reality system was developed. First, a pair of stereo skin images obtained by a stereo camera generates a disparity map of skin wrinkles. Second, the generated disparity map is sent to an implemented tactile rendering algorithm that computes a reaction force according to the user's interaction with the skin image. We first obtained a stereo image of skin wrinkles from the in vivo stereo imaging system, which has a baseline of 50.8 μm, and obtained the disparity map with a graph cuts algorithm. The left image is displayed on the monitor to enable the user to recognize the location visually. The disparity map of the skin wrinkle image sends skin wrinkle information as a tactile response to the user through a haptic device. We successfully developed a tactile feedback system for virtual skin wrinkle simulation by means of a commercialized haptic device that provides the user with a single point of contact to feel the surface roughness of a virtual skin sample. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Technologies for learner-centered feedback

    Directory of Open Access Journals (Sweden)

    Jane Costello

    2013-09-01

    Full Text Available As the number, type, and use of technologies to support learning increases, so do the opportunities for using these technologies for feedback. Learner-centered feedback is a core to the teaching-learning process. It is related to assessment in describing how learners perform in their learning, their gain in knowledge, skills, and attitudes. Feedback, types of feedback, guidelines for effective learner-centered feedback, and feedback’s relationship to assessment are presented. Methods of providing feedback, for example, automated, audio scribe pens, digital audio, etc., and the related technologies are described. Technologies that allow instructors to make informed decisions about the use of various methods for feedback are discussed.

  9. Transfer of perceptual learning: role of tactual-kinesthetic feedback reexamined.

    Science.gov (United States)

    Anton, B S; Player, N I; Bennett, T L

    1981-02-01

    Albino rats were pre-exposed to stimuli in an otherwise visually sparse environment, with visibility and opportunity to manipulate the forms controlled during rearing. Analysis indicated that pre-exposing animals to stimuli which provided either tactual-kinesthetic feedback or highly visible forms significantly facilitated subsequent discrimination learning. The findings question the adequacy of either an attention-getting or tactual-kinesthetic feedback to account for differences in transfer effects in studies using two- and three-dimensional forms. It is suggested that the visibility of the forms and the opportunity to inspect the forms during pre-exposure is the important variable in studies of this type.

  10. Is sensorimotor BCI performance influenced differently by mono, stereo, or 3-D auditory feedback?

    Science.gov (United States)

    McCreadie, Karl A; Coyle, Damien H; Prasad, Girijesh

    2014-05-01

    Imagination of movement can be used as a control method for a brain-computer interface (BCI) allowing communication for the physically impaired. Visual feedback within such a closed loop system excludes those with visual problems and hence there is a need for alternative sensory feedback pathways. In the context of substituting the visual channel for the auditory channel, this study aims to add to the limited evidence that it is possible to substitute visual feedback for its auditory equivalent and assess the impact this has on BCI performance. Secondly, the study aims to determine for the first time if the type of auditory feedback method influences motor imagery performance significantly. Auditory feedback is presented using a stepped approach of single (mono), double (stereo), and multiple (vector base amplitude panning as an audio game) loudspeaker arrangements. Visual feedback involves a ball-basket paradigm and a spaceship game. Each session consists of either auditory or visual feedback only with runs of each type of feedback presentation method applied in each session. Results from seven subjects across five sessions of each feedback type (visual, auditory) (10 sessions in total) show that auditory feedback is a suitable substitute for the visual equivalent and that there are no statistical differences in the type of auditory feedback presented across five sessions.

  11. PEER FEEDBACK ON LANGUAGE FORM IN TELECOLLABORATION

    Directory of Open Access Journals (Sweden)

    Paige Ware

    2008-02-01

    Full Text Available We performed a two-phase, year-long research project that explored the impact of peer feedback on language development. We investigated specifically how and when post-secondary learners of English and Spanish provide corrective feedback on their partners' use of the target language in weekly asynchronous discussions by assigning them to one of two conditions: e-tutoring, in which students were asked to provide peer feedback on any linguistic form they perceived as incorrect; and e-partnering, in which students were not required to provide peer feedback but could do so on their own initiative. We examined the frequency and type of language use by coding the feedback for language-related episodes (Swain & Lapkin, 1998 and for feedback strategies (Ros i Solé & Truman, 2005. The findings indicate that students in both conditions preferred an inclusion of feedback on form as part of their exchange, but such feedback only occurred when explicitly required in the e-tutoring condition. Pedagogical implications include the need to situate peer feedback on form within current models of telecollaboration and to assist students in using feedback strategies such as reformulations, which do not rely on a deep understanding of the target or native language grammar.

  12. Humans can integrate feedback of discrete events in their sensorimotor control of a robotic hand.

    Science.gov (United States)

    Cipriani, Christian; Segil, Jacob L; Clemente, Francesco; ff Weir, Richard F; Edin, Benoni

    2014-11-01

    Providing functionally effective sensory feedback to users of prosthetics is a largely unsolved challenge. Traditional solutions require high band-widths for providing feedback for the control of manipulation and yet have been largely unsuccessful. In this study, we have explored a strategy that relies on temporally discrete sensory feedback that is technically simple to provide. According to the Discrete Event-driven Sensory feedback Control (DESC) policy, motor tasks in humans are organized in phases delimited by means of sensory encoded discrete mechanical events. To explore the applicability of DESC for control, we designed a paradigm in which healthy humans operated an artificial robot hand to lift and replace an instrumented object, a task that can readily be learned and mastered under visual control. Assuming that the central nervous system of humans naturally organizes motor tasks based on a strategy akin to DESC, we delivered short-lasting vibrotactile feedback related to events that are known to forcefully affect progression of the grasp-lift-and-hold task. After training, we determined whether the artificial feedback had been integrated with the sensorimotor control by introducing short delays and we indeed observed that the participants significantly delayed subsequent phases of the task. This study thus gives support to the DESC policy hypothesis. Moreover, it demonstrates that humans can integrate temporally discrete sensory feedback while controlling an artificial hand and invites further studies in which inexpensive, noninvasive technology could be used in clever ways to provide physiologically appropriate sensory feedback in upper limb prosthetics with much lower band-width requirements than with traditional solutions.

  13. Positive or negative feedback of optokinetic signals: degree of the misrouted optic flow determines system dynamics of human ocular motor behavior.

    Science.gov (United States)

    Chen, Chien-Cheng; Bockisch, Christopher J; Olasagasti, Itsaso; Weber, Konrad P; Straumann, Dominik; Huang, Melody Ying-Yu

    2014-04-09

    The optokinetic system in healthy humans is a negative-feedback system that stabilizes gaze: slow-phase eye movements (i.e., the output signal) minimize retinal slip (i.e., the error signal). A positive-feedback optokinetic system may exist due to the misrouting of optic fibers. Previous studies have shown that, in a zebrafish mutant with a high degree of the misrouting, the optokinetic response (OKR) is reversed. As a result, slow-phase eye movements amplify retinal slip, forming a positive-feedback optokinetic loop. The positive-feedback optokinetic system cannot stabilize gaze, thus leading to spontaneous eye oscillations (SEOs). Because the misrouting in human patients (e.g., with a condition of albinism or achiasmia) is partial, both positive- and negative-feedback loops co-exist. How this co-existence affects human ocular motor behavior remains unclear. We presented a visual environment consisting of two stimuli in different parts of the visual field to healthy subjects. One mimicked positive-feedback optokinetic signals and the other preserved negative-feedback optokinetic signals. By changing the ratio and position of the visual field of these visual stimuli, various optic nerve misrouting patterns were simulated. Eye-movement responses to stationary and moving stimuli were measured and compared with computer simulations. The SEOs were correlated with the magnitude of the virtual positive-feedback optokinetic effect. We found a correlation among the simulated misrouting, the corresponding OKR, and the SEOs in humans. The proportion of the simulated misrouting needed to be greater than 50% to reverse the OKR and at least greater than or equal to 70% to evoke SEOs. Once the SEOs were evoked, the magnitude positively correlated to the strength of the positive-feedback OKR. This study provides a mechanism of how the misrouting of optic fibers in humans could lead to SEOs, offering a possible explanation for a subtype of infantile nystagmus syndrome (INS).

  14. Visual Analogue Scale for Anxiety and Amsterdam Preoperative Anxiety Scale Provide a Simple and Reliable Measurement of Preoperative Anxiety in Patients Undergoing Cardiac Surgery

    OpenAIRE

    Joaquín Hernández-Palazón; Diego Fuentes-García; Luis Falcón-Araña; Antonio Rodríguez-Ribó; Carlos García-Palenciano; María José Roca-Calvo

    2015-01-01

    Background: Anxiety is an emotional state characterized by apprehension and fear resulting from anticipation of a threatening event. Objectives: The present study aimed to analyze the incidence and level of preoperative anxiety in the patients scheduled for cardiac surgery by using a Visual Analogue Scale for Anxiety (VAS-A) and Amsterdam Preoperative Anxiety and Information Scale (APAIS) and to identify the influencing clinical factors. Patients and Methods: This prospective, longitu...

  15. Selective and divided attention modulates auditory-vocal integration in the processing of pitch feedback errors.

    Science.gov (United States)

    Liu, Ying; Hu, Huijing; Jones, Jeffery A; Guo, Zhiqiang; Li, Weifeng; Chen, Xi; Liu, Peng; Liu, Hanjun

    2015-08-01

    Speakers rapidly adjust their ongoing vocal productions to compensate for errors they hear in their auditory feedback. It is currently unclear what role attention plays in these vocal compensations. This event-related potential (ERP) study examined the influence of selective and divided attention on the vocal and cortical responses to pitch errors heard in auditory feedback regarding ongoing vocalisations. During the production of a sustained vowel, participants briefly heard their vocal pitch shifted up two semitones while they actively attended to auditory or visual events (selective attention), or both auditory and visual events (divided attention), or were not told to attend to either modality (control condition). The behavioral results showed that attending to the pitch perturbations elicited larger vocal compensations than attending to the visual stimuli. Moreover, ERPs were likewise sensitive to the attentional manipulations: P2 responses to pitch perturbations were larger when participants attended to the auditory stimuli compared to when they attended to the visual stimuli, and compared to when they were not explicitly told to attend to either the visual or auditory stimuli. By contrast, dividing attention between the auditory and visual modalities caused suppressed P2 responses relative to all the other conditions and caused enhanced N1 responses relative to the control condition. These findings provide strong evidence for the influence of attention on the mechanisms underlying the auditory-vocal integration in the processing of pitch feedback errors. In addition, selective attention and divided attention appear to modulate the neurobehavioral processing of pitch feedback errors in different ways. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. A lower visual field advantage for endpoint stability but no advantage for online movement precision.

    Science.gov (United States)

    Krigolson, Olav; Heath, Matthew

    2006-03-01

    It has been proposed that visually guided reaching movements performed in the lower visual field (LVF) of peripersonal space are more effective and efficient than their upper visual field (UVF) counterparts (Danckert and Goodale 2001). In the present investigation we sought to determine whether this purported visual field asymmetry reflects advantaged processing of online visual feedback. To accomplish that objective, participants performed discrete reaching movements to each of three target locations in the LVF and UVF. In addition, reaches were completed under conditions wherein target location remained constant throughout a reaching response (i.e., control trials) and a separate condition wherein target location unexpectedly perturbed at movement onset (i.e., experimental trials). We reasoned that the target perturbation paradigm would provide a novel means to assess a possible superior-inferior visual field asymmetry for online reaching control. In terms of the impact of a target perturbation, both visual fields demonstrated equal proficiency integrating visual feedback for online limb adjustments. Interestingly, however, the spatial distribution of movement endpoints in the LVF was less than UVF counterparts (cf. Binsted and Heath 2005). Taken together, the present findings suggest that although LVF and UVF reaches readily use visual feedback to accommodate an unexpected target perturbation, reaches in the LVF elicit advantaged spatial benefits influencing the effectiveness of online limb corrections.

  17. Positive and negative feedback learning and associated dopamine and serotonin transporter binding after methamphetamine.

    Science.gov (United States)

    Stolyarova, Alexandra; O'Dell, Steve J; Marshall, John F; Izquierdo, Alicia

    2014-09-01

    Learning from mistakes and prospectively adjusting behavior in response to reward feedback is an important facet of performance monitoring. Dopamine (DA) pathways play an important role in feedback learning and a growing literature has also emerged on the importance of serotonin (5HT) in reward learning, particularly during punishment or reward omission (negative feedback). Cognitive impairments resulting from psychostimulant exposure may arise from altered patterns in feedback learning, which in turn may be modulated by DA and 5HT transmission. We analyzed long-term, off-drug changes in learning from positive and negative feedback and associated striatal DA transporter (DAT) and frontocortical 5HT transporter (SERT) binding in rats pretreated with methamphetamine (mAMPH). Specifically, we assessed the reversal phase of pairwise visual discrimination learning in rats receiving single dose- (mAMPHsingle) vs. escalating-dose exposure (mAMPHescal). Using fine-grained trial-by-trial analyses, we found increased sensitivity to and reliance on positive feedback in mAMPH-pretreated animals, with the mAMPHsingle group showing more pronounced use of this type of feedback. In contrast, overall negative feedback sensitivity was not altered following any mAMPH treatment. In addition to validating the enduring effects of mAMPH on early reversal learning, we found more consecutive error commissions before the first correct response in mAMPH-pretreated rats. This behavioral rigidity was negatively correlated with subregional frontocortical SERT whereas positive feedback sensitivity negatively correlated with striatal DAT binding. These results provide new evidence for the overlapping, yet dissociable roles of DA and 5HT systems in overcoming perseveration and in learning new reward rules. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Rateless feedback codes

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Koike-Akino, Toshiaki; Orlik, Philip

    2012-01-01

    This paper proposes a concept called rateless feedback coding. We redesign the existing LT and Raptor codes, by introducing new degree distributions for the case when a few feedback opportunities are available. We show that incorporating feedback to LT codes can significantly decrease both...... the coding overhead and the encoding/decoding complexity. Moreover, we show that, at the price of a slight increase in the coding overhead, linear complexity is achieved with Raptor feedback coding....

  19. Developing Sustainable Feedback Practices

    Science.gov (United States)

    Carless, David; Salter, Diane; Yang, Min; Lam, Joy

    2011-01-01

    Feedback is central to the development of student learning, but within the constraints of modularized learning in higher education it is increasingly difficult to handle effectively. This article makes a case for sustainable feedback as a contribution to the reconceptualization of feedback processes. The data derive from the Student Assessment and…

  20. Driver feedback mobile APP

    Energy Technology Data Exchange (ETDEWEB)

    Soriguera Marti, F.; Miralles Miquel, E.

    2016-07-01

    This paper faces the human factor in driving and its consequences for road safety. It presents the concepts behind the development of a smartphone app capable of evaluating drivers’ performance. The app provides feedback to the driver in terms of a grade (between 0 and 10) depending on the aggressiveness and risks taken while driving. These are computed from the cumulative probability distribution function of the jerks (i.e. the time derivative of acceleration), which are measured using the smartphones’ accelerometer. Different driving contexts (e.g. urban, freeway, congestion, etc.) are identified applying cluster analysis to the measurements, and treated independently. Using regression analysis, the aggressiveness indicator is related to the drivers' safety records and to the probability of having an accident, through the standard DBQ - Driving Behavior Questionnaire. Results from a very limited pilot test show a strong correlation between the 99th percentile of the jerk measurements and the DBQ results. A linear model is fitted. This allows quantifying the safe driving behavior only from smartphone measurements. Finally, this indicator is translated into a normalized grade and feedback to the driver. This feedback will challenge the driver to train and to improve his performance. The phone will be blocked while driving and will incorporate mechanisms to prevent bad practices, like competition in aggressive driving. The app is intended to contribute to the improvement of road safety, one of the major public health problems, by tackling the human factor which is the trigger of the vast majority of traffic accidents. Making explicit and quantifying risky behaviors is the first step towards a safer driving. (Author)

  1. Using Feedback to Promote Physical Activity: The Role of the Feedback Sign.

    Science.gov (United States)

    Kramer, Jan-Niklas; Kowatsch, Tobias

    2017-06-02

    Providing feedback is a technique to promote health behavior that is emphasized by behavior change theories. However, these theories make contradicting predictions regarding the effect of the feedback sign-that is, whether the feedback signals success or failure. Thus, it is unclear whether positive or negative feedback leads to more favorable behavior change in a health behavior intervention. The aim of this study was to examine the effect of the feedback sign in a health behavior change intervention. Data from participants (N=1623) of a 6-month physical activity intervention was used. Participants received a feedback email at the beginning of each month. Feedback was either positive or negative depending on the participants' physical activity in the previous month. In an exploratory analysis, change in monthly step count averages was used to evaluate the feedback effect. The feedback sign did not predict the change in monthly step count averages over the course of the intervention (b=-84.28, P=.28). Descriptive differences between positive and negative feedback can be explained by regression to the mean. The feedback sign might not influence the effect of monthly feedback emails sent out to participants of a large-scale physical activity intervention. However, randomized studies are needed to further support this conclusion. Limitations as well as opportunities for future research are discussed.

  2. Model depicting aspects of audit and feedback that impact physicians' acceptance of clinical performance feedback.

    Science.gov (United States)

    Payne, Velma L; Hysong, Sylvia J

    2016-07-13

    Audit and feedback (A&F) is a strategy that has been used in various disciplines for performance and quality improvement. There is limited research regarding medical professionals' acceptance of clinical-performance feedback and whether feedback impacts clinical practice. The objectives of our research were to (1) investigate aspects of A&F that impact physicians' acceptance of performance feedback; (2) determine actions physicians take when receiving feedback; and (3) determine if feedback impacts physicians' patient-management behavior. In this qualitative study, we employed grounded theory methods to perform a secondary analysis of semi-structured interviews with 12 VA primary care physicians. We analyzed a subset of interview questions from the primary study, which aimed to determine how providers of high, low and moderately performing VA medical centers use performance feedback to maintain and improve quality of care, and determine perceived utility of performance feedback. Based on the themes emergent from our analysis and their observed relationships, we developed a model depicting aspects of the A&F process that impact feedback acceptance and physicians' patient-management behavior. The model is comprised of three core components - Reaction, Action and Impact - and depicts elements associated with feedback recipients' reaction to feedback, action taken when feedback is received, and physicians modifying their patient-management behavior. Feedback characteristics, the environment, external locus-of-control components, core values, emotion and the assessment process induce or deter reaction, action and impact. Feedback characteristics (content and timeliness), and the procedural justice of the assessment process (unjust penalties) impact feedback acceptance. External locus-of-control elements (financial incentives, competition), the environment (patient volume, time constraints) and emotion impact patient-management behavior. Receiving feedback generated

  3. Frequent feedback enhances complex motor skill learning.

    Science.gov (United States)

    Wulf, G; Shea, C H; Matschiner, S

    1998-06-01

    Feedback frequency effects on the learning of a complex motor skill, the production of slalom-type movements on a ski-simulator, were examined. In Experiment 1, a movement feature that characterizes expert performance was identified. Participants (N = 8) practiced the task for 6 days. Significant changes across practice were found for movement amplitude and relative force onset. Relative force onset is considered a measure of movement efficiency; relatively late force onsets characterize expert performance. In Experiment 2, different groups of participants (N = 27) were given concurrent feedback about force onset on either 100% or 50% of the practice trials; a control group was given no feedback. The following hypothesis was tested: Contrary to previous findings concerning relatively simple tasks, for the learning of a complex task such as the one used here, a high relative feedback frequency (100%) is more beneficial for learning than a reduced feedback frequency (50%). Participants practiced the task on 2 consecutive days and performed a retention test without feedback on Day 3. The 100% feedback group demonstrated later relative force onsets than the control group in retention; the 50% feedback group showed intermediate performance. The results provide support for the notion that high feedback frequencies are beneficial for the learning of complex motor skills, at least until a certain level of expertise is achieved. That finding suggests that there may be an interaction between task difficulty and feedback frequency similar to the interaction found in the summary-KR literature.

  4. Looking at the ventriloquist: visual outcome of eye movements calibrates sound localization.

    Directory of Open Access Journals (Sweden)

    Daniel S Pages

    Full Text Available A general problem in learning is how the brain determines what lesson to learn (and what lessons not to learn. For example, sound localization is a behavior that is partially learned with the aid of vision. This process requires correctly matching a visual location to that of a sound. This is an intrinsically circular problem when sound location is itself uncertain and the visual scene is rife with possible visual matches. Here, we develop a simple paradigm using visual guidance of sound localization to gain insight into how the brain confronts this type of circularity. We tested two competing hypotheses. 1: The brain guides sound location learning based on the synchrony or simultaneity of auditory-visual stimuli, potentially involving a Hebbian associative mechanism. 2: The brain uses a 'guess and check' heuristic in which visual feedback that is obtained after an eye movement to a sound alters future performance, perhaps by recruiting the brain's reward-related circuitry. We assessed the effects of exposure to visual stimuli spatially mismatched from sounds on performance of an interleaved auditory-only saccade task. We found that when humans and monkeys were provided the visual stimulus asynchronously with the sound but as feedback to an auditory-guided saccade, they shifted their subsequent auditory-only performance toward the direction of the visual cue by 1.3-1.7 degrees, or 22-28% of the original 6 degree visual-auditory mismatch. In contrast when the visual stimulus was presented synchronously with the sound but extinguished too quickly to provide this feedback, there was little change in subsequent auditory-only performance. Our results suggest that the outcome of our own actions is vital to localizing sounds correctly. Contrary to previous expectations, visual calibration of auditory space does not appear to require visual-auditory associations based on synchrony/simultaneity.

  5. Utilizing Implicit User Feedback to Improve Interactive Video Retrieval

    Directory of Open Access Journals (Sweden)

    Stefanos Vrochidis

    2011-01-01

    Full Text Available This paper describes an approach to exploit the implicit user feedback gathered during interactive video retrieval tasks. We propose a framework, where the video is first indexed according to temporal, textual, and visual features and then implicit user feedback analysis is realized using a graph-based methodology. The generated graph encodes the semantic relations between video segments based on past user interaction and is subsequently used to generate recommendations. Moreover, we combine the visual features and implicit feedback information by training a support vector machine classifier with examples generated from the aforementioned graph in order to optimize the query by visual example search. The proposed framework is evaluated by conducting real-user experiments. The results demonstrate that significant improvement in terms of precision and recall is reported after the exploitation of implicit user feedback, while an improved ranking is presented in most of the evaluated queries by visual example.

  6. Haptic force-feedback devices for the office computer: performance and musculoskeletal loading issues.

    Science.gov (United States)

    Dennerlein, J T; Yang, M C

    2001-01-01

    Pointing devices, essential input tools for the graphical user interface (GUI) of desktop computers, require precise motor control and dexterity to use. Haptic force-feedback devices provide the human operator with tactile cues, adding the sense of touch to existing visual and auditory interfaces. However, the performance enhancements, comfort, and possible musculoskeletal loading of using a force-feedback device in an office environment are unknown. Hypothesizing that the time to perform a task and the self-reported pain and discomfort of the task improve with the addition of force feedback, 26 people ranging in age from 22 to 44 years performed a point-and-click task 540 times with and without an attractive force field surrounding the desired target. The point-and-click movements were approximately 25% faster with the addition of force feedback (paired t-tests, p < 0.001). Perceived user discomfort and pain, as measured through a questionnaire, were also smaller with the addition of force feedback (p < 0.001). However, this difference decreased as additional distracting force fields were added to the task environment, simulating a more realistic work situation. These results suggest that for a given task, use of a force-feedback device improves performance, and potentially reduces musculoskeletal loading during mouse use. Actual or potential applications of this research include human-computer interface design, specifically that of the pointing device extensively used for the graphical user interface.

  7. Pulsed feedback defers cellular differentiation.

    Directory of Open Access Journals (Sweden)

    Joe H Levine

    2012-01-01

    Full Text Available Environmental signals induce diverse cellular differentiation programs. In certain systems, cells defer differentiation for extended time periods after the signal appears, proliferating through multiple rounds of cell division before committing to a new fate. How can cells set a deferral time much longer than the cell cycle? Here we study Bacillus subtilis cells that respond to sudden nutrient limitation with multiple rounds of growth and division before differentiating into spores. A well-characterized genetic circuit controls the concentration and phosphorylation of the master regulator Spo0A, which rises to a critical concentration to initiate sporulation. However, it remains unclear how this circuit enables cells to defer sporulation for multiple cell cycles. Using quantitative time-lapse fluorescence microscopy of Spo0A dynamics in individual cells, we observed pulses of Spo0A phosphorylation at a characteristic cell cycle phase. Pulse amplitudes grew systematically and cell-autonomously over multiple cell cycles leading up to sporulation. This pulse growth required a key positive feedback loop involving the sporulation kinases, without which the deferral of sporulation became ultrasensitive to kinase expression. Thus, deferral is controlled by a pulsed positive feedback loop in which kinase expression is activated by pulses of Spo0A phosphorylation. This pulsed positive feedback architecture provides a more robust mechanism for setting deferral times than constitutive kinase expression. Finally, using mathematical modeling, we show how pulsing and time delays together enable "polyphasic" positive feedback, in which different parts of a feedback loop are active at different times. Polyphasic feedback can enable more accurate tuning of long deferral times. Together, these results suggest that Bacillus subtilis uses a pulsed positive feedback loop to implement a "timer" that operates over timescales much longer than a cell cycle.

  8. Simultaneous visualization of two Citrus tristeza virus genotypes provides new insights into the structure of multi-component virus populations in a host.

    Science.gov (United States)

    Bergua, María; Phelan, Dane M; Bak, Aurélie; Bloom, David C; Folimonova, Svetlana Y

    2016-04-01

    Complex Citrus tristeza virus (CTV) populations composed of mixtures of different strains of the virus are commonly found in citrus trees in the field. At present, little is known about how these populations are formed, maintained, and how they are structured within a host. Here we used a novel in situ hybridization approach allowing simultaneous visualization of two different RNA targets with high sensitivity and specificity to examine the distribution of two isolates, T36 and T68-1, representing phylogenetically distinct strains of CTV, in a citrus host in single and mixed infections. Remarkably, in doubly inoculated plants the two virus variants appeared to be well mixed within the infected tissue and showed no spatial segregation. In addition, both CTV variants were often found occupying the same cells. Possible mechanisms involved in shaping CTV populations and the biological significance of the observed lack of structural separation of the individual components are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Feedback and efficient behavior.

    Science.gov (United States)

    Casal, Sandro; DellaValle, Nives; Mittone, Luigi; Soraperra, Ivan

    2017-01-01

    Feedback is an effective tool for promoting efficient behavior: it enhances individuals' awareness of choice consequences in complex settings. Our study aims to isolate the mechanisms underlying the effects of feedback on achieving efficient behavior in a controlled environment. We design a laboratory experiment in which individuals are not aware of the consequences of different alternatives and, thus, cannot easily identify the efficient ones. We introduce feedback as a mechanism to enhance the awareness of consequences and to stimulate exploration and search for efficient alternatives. We assess the efficacy of three different types of intervention: provision of social information, manipulation of the frequency, and framing of feedback. We find that feedback is most effective when it is framed in terms of losses, that it reduces efficiency when it includes information about inefficient peers' behavior, and that a lower frequency of feedback does not disrupt efficiency. By quantifying the effect of different types of feedback, our study suggests useful insights for policymakers.

  10. Feedback and Incentives

    DEFF Research Database (Denmark)

    Eriksson, Tor Viking; Poulsen, Anders; Villeval, Marie Claire

    2009-01-01

    use two pay schemes, a piece rate and a tournament. We find that overall feedback does not improve performance. In contrast to the piece-rate pay scheme there is some evidence of positive peer effects in tournaments since the underdogs almost never quit the competition even when lagging significantly......This paper experimentally investigates the impact of different pay schemes and relative performance feedback policies on employee effort. We explore three feedback rules: no feedback on relative performance, feedback given halfway through the production period, and continuously updated feedback. We...... behind, and front runners do not slack off. But in both pay schemes relative performance feedback reduces the quality of the low performers' work; we refer to this as a "negative quality peer effect"....

  11. Linear feedback controls the essentials

    CERN Document Server

    Haidekker, Mark A

    2013-01-01

    The design of control systems is at the very core of engineering. Feedback controls are ubiquitous, ranging from simple room thermostats to airplane engine control. Helping to make sense of this wide-ranging field, this book provides a new approach by keeping a tight focus on the essentials with a limited, yet consistent set of examples. Analysis and design methods are explained in terms of theory and practice. The book covers classical, linear feedback controls, and linear approximations are used when needed. In parallel, the book covers time-discrete (digital) control systems and juxtapos

  12. Does source matter? Nurses' and Physicians' perceptions of interprofessional feedback.

    Science.gov (United States)

    van Schaik, Sandrijn M; O'Sullivan, Patricia S; Eva, Kevin W; Irby, David M; Regehr, Glenn

    2016-02-01

    Receptiveness to interprofessional feedback, which is important for optimal collaboration, may be influenced by 'in-group or out-group' categorisation, as suggested by social identity theory. We used an experimental design to explore how nurses and resident physicians perceive feedback from people within and outside their own professional group. Paediatric residents and nurses participated in a simulation-based team exercise. Two nurses and two physicians wrote anonymous performance feedback for each participant. Participants each received a survey containing these feedback comments with prompts to rate (i) the usefulness (ii) the positivity and (iii) their agreement with each comment. Half of the participants received feedback labelled with the feedback provider's profession (two comments correctly labelled and two incorrectly labelled). Half received unlabelled feedback and were asked to guess the provider's profession. For each group, we performed separate three-way anovas on usefulness, positivity and agreement ratings to examine interactions between the recipient's profession, actual provider profession and perceived provider profession. Forty-five out of 50 participants completed the survey. There were no significant interactions between profession of the recipient and the actual profession of the feedback provider for any of the 3 variables. Among participants who guessed the source of the feedback, we found significant interactions between the profession of the feedback recipient and the guessed source of the feedback for both usefulness (F1,48 = 25.6; p feedback they guessed to be from nurses were higher than ratings of feedback they guessed to be from physicians, and vice versa. Among participants who received labelled feedback, we noted a similar interaction between the profession of the feedback recipient and labelled source of feedback for usefulness ratings (F1,92 = 4.72; p feedback to the in-group than to the out-group. This finding has potential

  13. Persuasive performance feedback: the effect of framing on self-efficacy.

    Science.gov (United States)

    Choe, Eun Kyoung; Lee, Bongshin; Munson, Sean; Pratt, Wanda; Kientz, Julie A

    2013-01-01

    Self-monitoring technologies have proliferated in recent years as they offer excellent potential for promoting healthy behaviors. Although these technologies have varied ways of providing real-time feedback on a user's current progress, we have a dearth of knowledge of the framing effects on the performance feedback these tools provide. With an aim to create influential, persuasive performance feedback that will nudge people toward healthy behaviors, we conducted an online experiment to investigate the effect of framing on an individual's self-efficacy. We identified 3 different types of framing that can be applicable in presenting performance feedback: (1) the valence of performance (remaining vs. achieved framing), (2) presentation type (text-only vs. text with visual), and (3) data unit (raw vs. percentage). Results show that the achieved framing could lead to an increased perception of individual's performance capabilities. This work provides empirical guidance for creating persuasive performance feedback, thereby helping people designing self-monitoring technologies to promote healthy behaviors.

  14. AGN feedback in dwarf galaxies?

    Science.gov (United States)

    Dashyan, Gohar; Silk, Joseph; Mamon, Gary A.; Dubois, Yohan; Hartwig, Tilman

    2018-02-01

    Dwarf galaxy anomalies, such as their abundance and cusp-core problems, remain a prime challenge in our understanding of galaxy formation. The inclusion of baryonic physics could potentially solve these issues, but the efficiency of stellar feedback is still controversial. We analytically explore the possibility of feedback from active galactic nuclei (AGNs) in dwarf galaxies and compare AGN and supernova (SN) feedback. We assume the presence of an intermediate-mass black hole within low-mass galaxies and standard scaling relations between the relevant physical quantities. We model the propagation and properties of the outflow and explore the critical condition for global gas ejection. Performing the same calculation for SNe, we compare the ability of AGNs and SNe to drive gas out of galaxies. We find that a critical halo mass exists below which AGN feedback can remove gas from the host halo and that the critical halo mass for an AGN is greater than the equivalent for SNe in a significant part of the parameter space, suggesting that an AGN could provide an alternative and more successful source of negative feedback than SNe, even in the most massive dwarf galaxies.

  15. INDIRECT WRITTEN CORRECTIVE FEEDBACK, REVISION, AND LEARNING

    Directory of Open Access Journals (Sweden)

    Fatemeh Poorebrahim

    2017-01-01

    Full Text Available Corrective feedback, the necessity of providing it, and how it should be provided has been one of the hot topics in the area of ELT. Amid continuing controversies over whether providing feedback helps L2 learners improve their writing accuracy, many research studies have been undertaken to compare the relative effectiveness of different types of feedback. However, the difference between two types of indirect corrective feedback, namely indication and indication plus location, have not been properly examined yet. Motivated to narrow this gap, this study is designed to compare two groups of Iranian learners, each revising their papers based on one of the aforementioned options. For data analysis, a series of independent samples t tests were employed. The results revealed that the difference between the two groups in their reduction of errors from the original draft to the revision of each task followed a growing trend and became significant. Nonetheless, the difference in accuracy of new pieces of writing fell short of significance. Finally, it was found that error reduction in revision stage cannot be considered as learning. The results of the study, discussed in relation to that of others, implicate that the purpose for which feedback is provided is essential in determining the type of feedback; more explicit feedback is better for revising purposes while more implicit feedback is good for learning purposes.

  16. Optical feedback structures and methods of making

    Science.gov (United States)

    None

    2014-11-18

    An optical resonator can include an optical feedback structure disposed on a substrate, and a composite including a matrix including a chromophore. The composite disposed on the substrate and in optical communication with the optical feedback structure. The chromophore can be a semiconductor nanocrystal. The resonator can provide laser emission when excited.

  17. Towards Visual Sedimentation

    OpenAIRE

    Huron, Samuel; Vuillemot, Romain; Fekete, Jean-Daniel

    2012-01-01

    This Poster receive the Best Poster award from the IEEE INFOVIS committee.; International audience; We present Visual Sedimentation, a new design metaphor for visualizing streaming data inspired by the geological process of sedimentation. Our work started by early experiments visualiz- ing political Twitter streams during the French 2012 presidential elections, and social interactions during a TV show. In both cases, the positive feedback we received expressed an unexpectedly high level of en...

  18. A 2D virtual reality system for visual goal-driven navigation in zebrafish larvae

    OpenAIRE

    Adrien Jouary; Mathieu Haudrechy; Raphaël Candelier; German Sumbre

    2016-01-01

    International audience; Animals continuously rely on sensory feedback to adjust motor commands. In order to study the role of visual feedback in goal-driven navigation, we developed a 2D visual virtual reality system for zebrafish larvae. The visual feedback can be set to be similar to what the animal experiences in natural conditions. Alternatively, modification of the visual feedback can be used to study how the brain adapts to perturbations. For this purpose, we first generated a library o...

  19. Module structure of interphotoreceptor retinoid-binding protein (IRBP may provide bases for its complex role in the visual cycle – structure/function study of Xenopus IRBP

    Directory of Open Access Journals (Sweden)

    Ghosh Debashis

    2007-08-01

    Full Text Available Abstract Background Interphotoreceptor retinoid-binding protein's (IRBP remarkable module structure may be critical to its role in mediating the transport of all-trans and 11-cis retinol, and 11-cis retinal between rods, cones, RPE and Müller cells during the visual cycle. We isolated cDNAs for Xenopus IRBP, and expressed and purified its individual modules, module combinations, and the full-length polypeptide. Binding of all-trans retinol, 11-cis retinal and 9-(9-anthroyloxy stearic acid were characterized by fluorescence spectroscopy monitoring ligand-fluorescence enhancement, quenching of endogenous protein fluorescence, and energy transfer. Finally, the X-ray crystal structure of module-2 was used to predict the location of the ligand-binding sites, and compare their structures among modules using homology modeling. Results The full-length Xenopus IRBP cDNA codes for a polypeptide of 1,197 amino acid residues beginning with a signal peptide followed by four homologous modules each ~300 amino acid residues in length. Modules 1 and 3 are more closely related to each other than either is to modules 2 and 4. Modules 1 and 4 are most similar to the N- and C-terminal modules of the two module IRBP of teleosts. Our data are consistent with the model that vertebrate IRBPs arose through two genetic duplication events, but that the middle two modules were lost during the evolution of the ray finned fish. The sequence of the expressed full-length IRBP was confirmed by liquid chromatography-tandem mass spectrometry. The recombinant full-length Xenopus IRBP bound all-trans retinol and 11-cis retinaldehyde at 3 to 4 sites with Kd's of 0.2 to 0.3 μM, and was active in protecting all-trans retinol from degradation. Module 2 showed selectivity for all-trans retinol over 11-cis retinaldehyde. The binding data are correlated to the results of docking of all-trans-retinol to the crystal structure of Xenopus module 2 suggesting two ligand-binding sites

  20. Developing a Web-Based Developmental Feedback Program

    National Research Council Canada - National Science Library

    Douglas, Matthew

    2003-01-01

    Developmental feedback programs provide an opportunity to improve leadership practices by giving leaders feedback about their performance from a number of sources, This thesis expanded on Capt Doug Patton's pilot study (2002...

  1. Understanding constructive feedback: a commitment between teachers and students for academic and professional development.

    Science.gov (United States)

    Hamid, Yasir; Mahmood, Sajid

    2010-03-01

    This review highlights the need in the Pakistani medical education system for teachers and students to be able to: define constructive feedback; provide constructive feedback; identify standards for constructive feedback; identify a suitable model for the provision of constructive feedback and evaluate the use of constructive feedback. For the purpose of literature review we had defined the key word glossary as: feedback, constructive feedback, teaching constructive feedback, models for feedback, models for constructive feedback and giving and receiving feedback. The data bases for the search include: Medline (EBSCO), Web of Knowledge, SCOPUS, TRIP, ScienceDirect, Pubmed, U.K. Pubmed Central, ZETOC, University of Dundee Library catalogue, SCIRUS (Elsevier) and Google Scholar. This article states that the Pakistani medical schools do not reflect on or use the benefits of the constructive feedback process. The discussion about constructive feedback suggests that in the context of Pakistan, constructive feedback will facilitate the teaching and learning activities.

  2. The Neural Feedback Response to Error As a Teaching Signal for the Motor Learning System

    Science.gov (United States)

    Shadmehr, Reza

    2016-01-01

    When we experience an error during a movement, we update our motor commands to partially correct for this error on the next trial. How does experience of error produce the improvement in the subsequent motor commands? During the course of an erroneous reaching movement, proprioceptive and visual sensory pathways not only sense the error, but also engage feedback mechanisms, resulting in corrective motor responses that continue until the hand arrives at its goal. One possibility is that this feedback response is co-opted by the learning system and used as a template to improve performance on the next attempt. Here we used electromyography (EMG) to compare neural correlates of learning and feedback to test the hypothesis that the feedback response to error acts as a template for learning. We designed a task in which mixtures of error-clamp and force-field perturbation trials were used to deconstruct EMG time courses into error-feedback and learning components. We observed that the error-feedback response was composed of excitation of some muscles, and inhibition of others, producing a complex activation/deactivation pattern during the reach. Despite this complexity, across muscles the learning response was consistently a scaled version of the error-feedback response, but shifted 125 ms earlier in time. Across people, individuals who produced a greater feedback response to error, also learned more from error. This suggests that the feedback response to error serves as a teaching signal for the brain. Individuals who learn faster have a better teacher in their feedback control system. SIGNIFICANCE STATEMENT Our sensory organs transduce errors in behavior. To improve performance, we must generate better motor commands. How does the nervous system transform an error in sensory coordinates into better motor commands in muscle coordinates? Here we show that when an error occurs during a movement, the reflexes transform the sensory representation of error into motor

  3. Custom Formula-Based Visualizations for Savvy Designers"

    DEFF Research Database (Denmark)

    Kuhail, Mohammad Amin

    is iteratively refining Uvis based on feedback from savvy designers. Uvis provides novel cognitive aids that assist the designers in creating and refining custom visualizations. The third contribution is a usability evaluation of Uvis with savvy designers. The fourth contribution is a usability analysis......Despite their usefulness in many domains (e.g. healthcare, finance, etc.), custom visualizations remain tedious and hard to implement. It would be advantageous if savvy designers (designers with end-user development skills and much domain knowledge) could refine visualizations to their needs....... For instance, it would save time and money if a clinician familiar with spreadsheet formulas could refine a visualization (e.g. the lifelines) rather than hiring a programmer. Existing approaches to visualization are one of the two: accessible to savvy designers but limited in customizability, or inaccessible...

  4. Contributions of the hippocampus to feedback learning.

    Science.gov (United States)

    Dickerson, Kathryn C; Delgado, Mauricio R

    2015-12-01

    Humans learn about the world in a variety of manners, including by observation, by associating cues in the environment, and via feedback. Across species, two brain structures have been predominantly involved in these learning processes: the hippocampus--supporting learning via observation and paired association--and the striatum--critical for feedback learning. This simple dichotomy, however, has recently been challenged by reports of hippocampal engagement in feedback learning, although the role of the hippocampus is not fully understood. The purpose of this experiment was to characterize the hippocampal response during feedback learning by manipulating varying levels of memory interference. Consistent with prior reports, feedback learning recruited the striatum and midbrain. Notably, feedback learning also engaged the hippocampus. The level of activity in these regions was modulated by the degree of memory interference, such that the greatest activation occurred during the highest level of memory interference. Importantly, the accuracy of information learned via feedback correlated with hippocampal activation and was reduced by the presence of high memory interference. Taken together, these findings provide evidence of hippocampal involvement in feedback learning by demonstrating both its relevance for the accuracy of information learned via feedback and its susceptibility to interference.

  5. The Surface Warfare Community's 360-Degree Feedback Pilot Program: A Preliminary Analysis and Evaluation Plan

    National Research Council Canada - National Science Library

    Williams, James M

    2005-01-01

    The system known as 360-degree feedback, also called multi-source or multi-rater feedback, is a development program that provides a recipient with feedback from supervisors, peers, and subordinates...

  6. New epifluorescence microscope providing pairs of specific fluorescence images of double-stained cells for simultaneous visual perception and for quantification

    Science.gov (United States)

    Heiden, Thomas; Tribukait, Bernhard

    1996-05-01

    A new epi-fluorescence microscope for analysis of cells stained with two fluorochromes which can be spectrally isolated is described. The system makes it possible to perform independent and specific spectral selection of each dye (e.g. DAPI and CY3) while perceiving the two specific images simultaneously by eye. The optics uses splitting of the primary excitation and emission light beams, independent modification of the separated beams, and their reunification. Modifications in the separated beams comprise: (1) isolation of specific wavelengths (365 nm and 546 nm in the excitation light path, 435 - 500 nm and 590 - 750 nm in the emission light beams), (2) wavelength switching without image displacement and blur by means of a light chopper alternating between ultraviolet-excitation/blue-detection and green-excitation/red-detection at frequencies of up to 140 Hz for observation by eye without image flicker, and (3) the possible separate positioning of lenses for compensation of chromatic aberrations. The system demonstrates a good transmission of the chosen wavelengths. A high specificity of double fluorescence analysis with minimal effects of spectral overlap was attained with good temporal resolution. It has been shown that it is feasible to obtain separate chromatic compensations for the use of a microscope objective in spectral regions outside the range for which the objective is corrected. Quantitative and independent measurements of the two fluorescence images by a CCD camera synchronized with the light chopper are feasible. In conclusion, this imaging system is outlined for highly specific visual analysis and exact quantitative measurement of double fluorescence labeled specimens in cytology and histology.

  7. Factors associated with the modulation of pain by visual distortion of body size.

    Directory of Open Access Journals (Sweden)

    Michihiro eOsumi

    2014-03-01

    Full Text Available Modulation of pain using visual distortion of body size (VDBS has been the subject of various reports. However, the mechanism underlying the effect of VDBS on pain has been less often studied. In the present study, factors associated with modulation of pain threshold by VDBS were investigated. Visual feedback in the form of a magnified image of the hand was provided to 44 healthy adults to examine changes in pain. In participants with a higher pain threshold when visual feedback of a magnified image of the hand was provided, the two-point discrimination threshold decreased. In contrast, participants with a lower pain threshold with visual feedback of a magnified image of the hand experienced unpleasant emotions toward the magnified image of the hand. Interestingly, this emotional reaction was strongly associated with negative body consciousness in several subjects. These data suggested an analgesic effect of visual feedback in the form of a magnified image of the hand is only when tactile perception is vivid and the emotional reaction toward the magnified image is moderate. The results also suggested that negative body consciousness is important for the modulation of pain using VDBS.

  8. Visual function of children with visual and other disabilities in Oman: A case series.

    Science.gov (United States)

    Gogri, Urmi; Khandekar, Rajiv; Al Harby, Salah

    2016-12-01

    We assessed the visual functioning of the children with special needs in Oman between 2009 and 2012. We present the methods of assessing different visual functions, outcomes, and interventions carried out to improve their functioning. Optometrists assessed visual functions of children of "Day care centres" in Oman. Experts further assessed them and provided low vision care. Ocular movements, refractive corrections, near, distance, contrast color, motion, field of vision, and cognitive visual function test results were noted. Feedback to caregivers was given to improve visual functioning of these children. We grouped 321 participants, (196 [61.1%] boys, age range of 3-18 years) into 61; Down syndrome (DS), 72 with intellectual disabilities (IDs), 67; hearing impaired and 121 with other conditions. Refractive error and lag of accommodation were 26 (42.6%) and 14 (22.6%) among children with DS. Contrast sensitivity was impaired in 8 (12.7%) among hearing impaired children. Defective distant and near vision was in 162 (70%) and 104 (42%) of our cohort. Children with ID were most difficult to assess. Children in a group of other disabilities had a higher proportion of impaired visual functioning. They were given low vision aids (telescopes [22], filters [7], and magnifiers [3]) in large numbers compared to those in other groups. Visual functioning of children with other disabilities show great variation and difficult to group. The care, therefore, should be at individual level. All visual functions cannot be assessed at one time.

  9. Visual function of children with visual and other disabilities in Oman: A case series

    Directory of Open Access Journals (Sweden)

    Urmi Gogri

    2016-01-01

    Full Text Available Background: We assessed the visual functioning of the children with special needs in Oman between 2009 and 2012. We present the methods of assessing different visual functions, outcomes, and interventions carried out to improve their functioning. Methods: Optometrists assessed visual functions of children of “Day care centres” in Oman. Experts further assessed them and provided low vision care. Ocular movements, refractive corrections, near, distance, contrast color, motion, field of vision, and cognitive visual function test results were noted. Feedback to caregivers was given to improve visual functioning of these children. Results: We grouped 321 participants, (196 [61.1%] boys, age range of 3–18 years into 61; Down syndrome (DS, 72 with intellectual disabilities (IDs, 67; hearing impaired and 121 with other conditions. Refractive error and lag of accommodation were 26 (42.6% and 14 (22.6% among children with DS. Contrast sensitivity was impaired in 8 (12.7% among hearing impaired children. Defective distant and near vision was in 162 (70% and 104 (42% of our cohort. Children with ID were most difficult to assess. Children in a group of other disabilities had a higher proportion of impaired visual functioning. They were given low vision aids (telescopes [22], filters [7], and magnifiers [3] in large numbers compared to those in other groups. Conclusions: Visual functioning of children with other disabilities show great variation and difficult to group. The care, therefore, should be at individual level. All visual functions cannot be assessed at one time.

  10. RF feedback for KEKB

    Energy Technology Data Exchange (ETDEWEB)

    Ezura, Eizi; Yoshimoto, Shin-ichi; Akai, Kazunori [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1996-08-01

    This paper describes the present status of the RF feedback development for the KEK B-Factory (KEKB). A preliminary experiment concerning the RF feedback using a parallel comb-filter was performed through a choke-mode cavity and a klystron. The RF feedback has been tested using the beam of the TRISTAN Main Ring, and has proved to be effective in damping the beam instability. (author)

  11. Neural cryptography with feedback.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Shacham, Lanir; Kanter, Ido

    2004-04-01

    Neural cryptography is based on a competition between attractive and repulsive stochastic forces. A feedback mechanism is added to neural cryptography which increases the repulsive forces. Using numerical simulations and an analytic approach, the probability of a successful attack is calculated for different model parameters. Scaling laws are derived which show that feedback improves the security of the system. In addition, a network with feedback generates a pseudorandom bit sequence which can be used to encrypt and decrypt a secret message.

  12. Neural cryptography with feedback

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Shacham, Lanir; Kanter, Ido

    2004-04-01

    Neural cryptography is based on a competition between attractive and repulsive stochastic forces. A feedback mechanism is added to neural cryptography which increases the repulsive forces. Using numerical simulations and an analytic approach, the probability of a successful attack is calculated for different model parameters. Scaling laws are derived which show that feedback improves the security of the system. In addition, a network with feedback generates a pseudorandom bit sequence which can be used to encrypt and decrypt a secret message.

  13. Pyff - a pythonic framework for feedback applications and stimulus presentation in neuroscience.

    Science.gov (United States)

    Venthur, Bastian; Scholler, Simon; Williamson, John; Dähne, Sven; Treder, Matthias S; Kramarek, Maria T; Müller, Klaus-Robert; Blankertz, Benjamin

    2010-01-01

    This paper introduces Pyff, the Pythonic feedback framework for feedback applications and stimulus presentation. Pyff provides a platform-independent framework that allows users to develop and run neuroscientific experiments in the programming language Python. Existing solutions have mostly been implemented in C++, which makes for a rather tedious programming task for non-computer-scientists, or in Matlab, which is not well suited for more advanced visual or auditory applications. Pyff was designed to make experimental paradigms (i.e., feedback and stimulus applications) easily programmable. It includes base classes for various types of common feedbacks and stimuli as well as useful libraries for external hardware such as eyetrackers. Pyff is also equipped with a steadily growing set of ready-to-use feedbacks and stimuli. It can be used as a standalone application, for instance providing stimulus presentation in psychophysics experiments, or within a closed loop such as in biofeedback or brain-computer interfacing experiments. Pyff communicates with other systems via a standardized communication protocol and is therefore suitable to be used with any system that may be adapted to send its data in the specified format. Having such a general, open-source framework will help foster a fruitful exchange of experimental paradigms between research groups. In particular, it will decrease the need of reprogramming standard paradigms, ease the reproducibility of published results, and naturally entail some standardization of stimulus presentation.

  14. Efficacy of live feedback to improve objectively monitored compliance to prescribed, home-based, exercise therapy-dosage in 15 to 19 year old adolescents with patellofemoral pain- a study protocol of a randomized controlled superiority trial (The XRCISE-AS-INSTRUcted-1 trial)

    DEFF Research Database (Denmark)

    Riel, Henrik; Matthews, Mark; Vicenzino, Bill

    2016-01-01

    feedback from a sensor (BandCizer™) and an iPad will improve the ability of adolescents with PFP to perform exercises as prescribed. METHODS: This study is a randomized, controlled, participant-blinded, superiority trial with a 2-group parallel design. Forty 15 to 19 year old adolescents...... with patellofemoral pain will be randomized to receive either live visual and auditory feedback on time under tension or no feedback on time under tension during a 6-week intervention period. Adolescents will be instructed to perform three elastic band exercises. Feedback will be provided by BandCizer™ and an i...

  15. Trainees' Perceptions of Feedback: Validity Evidence for Two FEEDME (Feedback in Medical Education) Instruments.

    Science.gov (United States)

    Bing-You, Robert; Ramesh, Saradha; Hayes, Victoria; Varaklis, Kalli; Ward, Denham; Blanco, Maria

    2017-12-14

    Construct: Medical educators consider feedback a core component of the educational process. Effective feedback allows learners to acquire new skills, knowledge, and attitudes. Learners' perceptions of feedback are an important aspect to assess with valid methods in order to improve the feedback skills of educators and the feedback culture. Although guidelines for delivering effective feedback have existed for several decades, medical students and residents often indicate that they receive little feedback. A recent scoping review on feedback in medical education did not reveal any validity evidence on instruments to assess learner's perceptions of feedback. The purpose of our study was to gather validity evidence on two novel FEEDME (Feedback in Medical Education) instruments to assess medical students' and residents' perceptions of the feedback that they receive. After the authors developed an initial instrument with 54 items, cognitive interviews with medical students and residents suggested that 2 separate instruments were needed, one focused on the feedback culture (FEEDME-Culture) and the other on the provider of feedback (FEEDME-Provider). A Delphi study with 17 medical education experts and faculty members assessed content validity. The response process was explored involving 31 medical students and residents at 2 academic institutions. Exploratory factor analysis and reliability analyses were performed on completed instruments. Two Delphi consultation rounds refined the wording of items and eliminated several items. Learners found both instruments easy and quick to answer; it took them less than 5 minutes to complete. Learners preferred an electronic format of the instruments over paper. Factor analysis revealed a two- and three-factor solution for the FEEDME-Culture and FEEDME-Provider instruments, respectively. Cronbach's alpha was greater than 0.80 for all factors. Items on both instruments were moderately to highly correlated (range, r = .3-.7). Our

  16. Feedback in surgical education.

    Science.gov (United States)

    El Boghdady, Michael; Alijani, Afshin

    2017-04-01

    The positive effect of feedback has long been recognized in surgical education. Surgical educators convey feedback to improve the performance of the surgical trainees. We aimed to review the scientific classification and application of feedback in surgical education, and to propose possible future directions for research. A literature search was performed using Pubmed, OVID, CINAHL, Web of science, EMBASE, ERIC database and Google Scholar. The following search terms were used: 'feedback', 'feedback in medical education', 'feedback in medical training' and 'feedback in surgery'. The search was limited to articles in English. From 1157 citations, 12 books and 43 articles met the inclusion criteria and were selected for this review. Feedback comes in a variety of types and is an essential tool for learning and developing performance in surgical education. Different methods of feedback application are evolving and future work needs to concentrate on the value of each method as well as the role of new technologies in surgical education. Copyright © 2016 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  17. Feedback stabilization initiative

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    Much progress has been made in attaining high confinement regimes in magnetic confinement devices. These operating modes tend to be transient, however, due to the onset of MHD instabilities, and their stabilization is critical for improved performance at steady state. This report describes the Feedback Stabilization Initiative (FSI), a broad-based, multi-institutional effort to develop and implement methods for raising the achievable plasma betas through active MHD feedback stabilization. A key element in this proposed effort is the Feedback Stabilization Experiment (FSX), a medium-sized, national facility that would be specifically dedicated to demonstrating beta improvement in reactor relevant plasmas by using a variety of MHD feedback stabilization schemes.

  18. Policy Feedback System (PFS)

    Data.gov (United States)

    Social Security Administration — The Policy Feedback System (PFS) is a web application developed by the Office of Disability Policy Management Information (ODPMI) team that gathers empirical data...

  19. Feedback Loop Gains and Feedback Behavior (1996)

    DEFF Research Database (Denmark)

    Kampmann, Christian Erik

    2012-01-01

    Linking feedback loops and system behavior is part of the foundation of system dynamics, yet the lack of formal tools has so far prevented a systematic application of the concept, except for very simple systems. Having such tools at their disposal would be a great help to analysts in understanding...... large, complicated simulation models. The paper applies tools from graph theory formally linking individual feedback loop strengths to the system eigenvalues. The significance of a link or a loop gain and an eigenvalue can be expressed in the eigenvalue elasticity, i.e., the relative change...... of an eigenvalue resulting from a relative change in the gain. The elasticities of individual links and loops may be found through simple matrix operations on the linearized system. Even though the number of feedback loops can grow rapidly with system size, reaching astronomical proportions even for modest systems...

  20. Effective Instructor Feedback: Perceptions of Online Graduate Students

    Directory of Open Access Journals (Sweden)

    Beverley Getzlaf

    2009-07-01

    Full Text Available This descriptive study explored online graduate students' perceptions of effective instructor feedback. The objectives of the study were to determine the students’ perceptions of the content of effective instructor feedback (“what should be included in effective feedback?” and the process of effective instructor feedback (“how should effective feedback be provided?”. The participants were students completing health-related graduate courses offered exclusively online. Data were collected via a survey that included open ended questions inviting participants to share their perspectives regarding effective online instructor feedback. Thematic analysis revealed five major themes: student involvement/individualization, gentle guidance, being positively constructive, timeliness and future orientation. We conclude that effective instructor feedback has positive outcomes for the students. Future studies are warranted to investigate strategies to make feedback a mutual process between instructor and student that supports an effective feedback cycle.

  1. Who Is Giving Feedback To Whom In Entrepreneurship Education?

    DEFF Research Database (Denmark)

    Trolle Elmholdt, Stine; Warhuus, Jan; Blenker, Per

    feedback, feedback, feed-forward and reflective feedback) (Evans, 2013) is used to understand the feedback mechanisms that may be used in entrepreneurship “through” courses. These different kinds of feedback mechanisms are positioned in the suggested two-by-two model to discuss how different kinds......The question we care about (objectives):When entrepreneurship is taught through the process of practicing entrepreneurship and based on experiential learning, a need arises for different forms of assessment, evaluation, and feedback procedures than those applied to traditional forms of higher...... evaluate and provide feedback on, with regard to both the teaching and the learning that takes place in these types of courses. We therefore ask: Who is giving feedback to whom in entrepreneurship education - and for what purpose?The intent of the paper is to develop and explore the system of feedback...

  2. How information visualization novices construct visualizations.

    Science.gov (United States)

    Grammel, Lars; Tory, Melanie; Storey, Margaret-Anne

    2010-01-01

    It remains challenging for information visualization novices to rapidly construct visualizations during exploratory data analysis. We conducted an exploratory laboratory study in which information visualization novices explored fictitious sales data by communicating visualization specifications to a human mediator, who rapidly constructed the visualizations using commercial visualization software. We found that three activities were central to the iterative visualization construction process: data attribute selection, visual template selection, and visual mapping specification. The major barriers faced by the participants were translating questions into data attributes, designing visual mappings, and interpreting the visualizations. Partial specification was common, and the participants used simple heuristics and preferred visualizations they were already familiar with, such as bar, line and pie charts. We derived abstract models from our observations that describe barriers in the data exploration process and uncovered how information visualization novices think about visualization specifications. Our findings support the need for tools that suggest potential visualizations and support iterative refinement, that provide explanations and help with learning, and that are tightly integrated into tool support for the overall visual analytics process.

  3. How we give personalised audio feedback after summative OSCEs.

    Science.gov (United States)

    Harrison, Christopher J; Molyneux, Adrian J; Blackwell, Sara; Wass, Valerie J

    2015-04-01

    Students often receive little feedback after summative objective structured clinical examinations (OSCEs) to enable them to improve their performance. Electronic audio feedback has shown promise in other educational areas. We investigated the feasibility of electronic audio feedback in OSCEs. An electronic OSCE system was designed, comprising (1) an application for iPads allowing examiners to mark in the key consultation skill domains, provide "tick-box" feedback identifying strengths and difficulties, and record voice feedback; (2) a feedback website giving students the opportunity to view/listen in multiple ways to the <