Grasping and functionally interacting with a relatively large or awkwardly shaped object requires the independent and cooperative coordination of both limbs. Acknowledging the vital role of visual information in successfully executing any prehensile movements, the present study aimed to clarify how well existing bimanual coordination models (Kelso et al, 1979; Marteniuk & Mackenzie, 1980) can account for bimanual prehension movements targeting a single end-point under varying visual conditions. We therefore, employed two experiments in which vision of the target object and limbs was available or unavailable during a bimanual movement in order to determine the affects of visual or memory-guided control (e.g. feedback vs. feed forward) on limb coordination.<p>Ten right-handed participants (mean age = 24.5) performed a specific bimanual prehension movement targeting a solitary, static object under both visual closed loop (CL) and open loop 2s delay (OL2) conditions. Target location was varied while target amplitude remained constant. Kinematic data (bimanual coupling variables) indicated that regardless of target location, participants employed one of two highly successful movement execution strategies depending on visual feedback availability. During visual (CL) conditions participants employed a dominant-hand initiation strategy characterized by a significantly faster right-hand (RH) reaction time and simultaneous hand contact with the target. In contrast, when no visual feedback was available (OL2), participants utilized a search and follow strategy characterized by limb coupling at movement onset and a reliance on the dominant RH to contact the target ~62 ms before the left.<p>In conclusion, the common goal parameters of targeting a single object with both hands are maintained and successfully achieved regardless of visual condition. Furthermore, independent programming of each limb is undeniably evident within the behaviours observed providing support for the neural cross-talk theory of bimanual coordination (Marteniuk & Mackenzie, 1980). Whether movement execution is visually (CL) or memory-guided (OL2) there is a clear preference of RH utilization possibly due to its dynamic and/or hemispheric advantages in controlling complex motor behaviours (Gonzalez et al., 2006). Therefore, we propose that bimanual grasping to a solitary target is possibly governed globally by a higher-level structure and successful execution is achieved via independent spinal pathway modulation of limbs.

Grasping and functionally interacting with a relatively large or awkwardly shaped object requires the independent and cooperative coordination of both limbs. Acknowledging the vital role of visual information in successfully executing any prehensile movements, the present study aimed to clarify how well existing bimanual coordination models (Kelso et al, 1979; Marteniuk & Mackenzie, 1980) can account for bimanual prehension movements targeting a single end-point under varying visual conditions. We therefore, employed two experiments in which vision of the target object and limbs was available or unavailable during a bimanual movement in order to determine the affects of visual or memory-guided control (e.g. feedback vs. feed forward) on limb coordination.<p>Ten right-handed participants (mean age = 24.5) performed a specific bimanual prehension movement targeting a solitary, static object under both visual closed loop (CL) and open loop 2s delay (OL2) conditions. Target location was varied while target amplitude remained constant. Kinematic data (bimanual coupling variables) indicated that regardless of target location, participants employed one of two highly successful movement execution strategies depending on visual feedback availability. During visual (CL) conditions participants employed a dominant-hand initiation strategy characterized by a significantly faster right-hand (RH) reaction time and simultaneous hand contact with the target. In contrast, when no visual feedback was available (OL2), participants utilized a search and follow strategy characterized by limb coupling at movement onset and a reliance on the dominant RH to contact the target ~62 ms before the left.<p>In conclusion, the common goal parameters of targeting a single object with both hands are maintained and successfully achieved regardless of visual condition. Furthermore, independent programming of each limb is undeniably evident within the behaviours observed providing support for the neural cross-talk theory of bimanual coordination (Marteniuk & Mackenzie, 1980). Whether movement execution is visually (CL) or memory-guided (OL2) there is a clear preference of RH utilization possibly due to its dynamic and/or hemispheric advantages in controlling complex motor behaviours (Gonzalez et al., 2006). Therefore, we propose that bimanual grasping to a solitary target is possibly governed globally by a higher-level structure and successful execution is achieved via independent spinal pathway modulation of limbs.

No description available.

<p>Brain Machine Interfaces (BMI) strive to restore motor and sensory functions lost due to paralysis, amputation, and neurological diseases by interfacing brain circuitry to external actuators in form of a cursor on a computer screen or a robotic limb. There is a strong clinical need for sensory restoration as lack of somatosensory feedback leads to loss of fine motor control and one of the most common preferences for improvements according to individuals with upper-limb loss is the ability to require less visual attention to perform certain functions and to have a better control of wrist movement. One way to restore sensory functions is using electrical microstimulation of brain sensory areas as an artificial sensory channel; however, the ways of creating such artificial sensory inputs are poorly understood. </p><p>This dissertation presents the use of intracortical microstimulation (ICMS) to the primary somatosensory cortex (S1) to guide exploratory arm movements without visual feedback. Two rhesus monkeys were chronically implanted with multielectrode arrays in S1 and primary motor cortex (M1). The monkeys used a hand-held joystick to reach targets with a cursor on a computer screen. ICMS patterns were delivered to S1 when the cursor was placed over the target, mimicking the sense of touch. After the target or the cursor was made invisible, monkeys relied on ICMS feedback instead of vision to perform the task. For an invisible cursor, a random offset was added to the position of the invisible cursor to rule out the possibility that monkeys relied on joystick position felt through proprioception. Learning to perform these tasks was accompanied by changes in both the parameters of arm movements and representation of those parameters by M1 and S1 neurons at a population and individual neuronal levels. </p><p>Offline decoding of single neurons and population of neurons showed that overlapping, but not identical subpopulations of neurons represented movements when ICMS provided feedback instead of vision.</p><p>These results suggest that ICMS could be used as an essential source of sensation from prosthetic limbs.</p> / Dissertation

Non-native tones are considered challenging for adult second language speakers to perceive and produce. The current study examined the effect of a laboratory-based intensive training in improving American English speakers’ tone production. Participants’ task was to repeat Mandarin words after the model. There were two conditions in the experiment: in one condition, participants did not get any external feedback; whereas in the other condition, participants received detailed visual feedback, which was the pitch contour of their tone production alongside the native version. Eight participants completed training with no feedback and another eight participants were trained with visual feedback. Results revealed that participants in both groups did not improve their tone production after training, and participants trained with visual feedback did not show more improvement than those trained with no feedback. Given the lack of improvement in participants’ tone production after training, methodological and theoretical limitations with respect to the use of a repetition-based training paradigm are discussed.

No description available.

Syfte och frågeställningar Syftet med arbetet var att undersöka om fotbollsspelare kan utveckla proprioception där visuell återkoppling systematiskt tas bort vid kontroll av bollen med fötterna. Frågeställningar: – Går det att utveckla förmågan att kontrollera bollen utan visuell återkoppling under en träningsperiod om fyra veckor och 12 träningspass?  – Hur förändras en fotbollsspelares prestation (kontroll av bollen) med avseende på en förbättrad proprioception med hänsyn tagen till: tid (sekunder), hastighet (varv/minut) samt antal tillfällen spelaren tittar respektive tappar boll? Metod Totalt 20 deltagare från ett pojkelitlag valdes ut och matchades inför träningsperioden in i en interventions- och en kontrollgrupp för att säkerhetsställa att båda grupperna var likvärdiga. Interventionsgruppen bestod av 12 deltagare, medelålder ± standardavvikelse (± SD) var 12,2 (± 0,2) år. Kontrollgruppen bestod av 8 deltagare, medelålder 12,0 (± 0,7) år. Interventionsgruppen har under fyra veckor genomfört fyra specifikt framtagna träningsövningar innehållandes uppvärmning inkluderat dribblingar och passningar, slalom, bollkontroll i lådram och smålagsspel. För att reducera testinlärningseffekten genomförde deltagarna ett introduktionspass innan förtestet. Under träningsperioden utfördes ett test-retest samt en träningseffektivitetsmätning. Efter avslutad träningsperiod genomfördes ett eftertest. Både under träningsperioden och vid testgenomförandet utrustades interventionsgruppen med specialdesignade glasögon för att på så sätt ta bort den visuella återkopplingen. Under förtestet fick alla deltagare bära ett gyro som mätte huvudvinkeln i sagittalplanet. ResultatFör interventionsgruppen i testövningen Lådan non-visuell uppgick resultatet till en förbättring med 50,9 % (p=0,001) och effect size (ES) =1,59 från för- till eftertest. Totalt antal bolltapp var 2 respektive 5 stycken. Kontrollgruppen presterade en förbättring om 4,7 % från för- till eftertest (p=0,306, ES=0,19). Totalt antal bolltapp var 2 respektive 4 stycken. Interventionsgruppen tillskrevs i testövningen Slalom non-visuell en förbättring om 24,9 % (p=0,004, ES=1,09). Kontrollgruppen försämrades med 12,6 % (p=0,105, ES=0,55). Interventiongruppens antal bolltapp vid för- och eftertest var 15 respektive 8 stycken. Kontrollgruppens antal bolltapp vid för- och eftertest var 5 respektive 3 stycken. Interventionsgruppens antal bolltitt var 18 respektive 9 stycken. Kontrollgruppens antal bolltitt var 10 respektive 3 stycken. Slutsats Det går att utveckla proprioceptionen genom att systematiskt ta bort visuell återkoppling vid kontroll av bollen med fötterna vid isolerade och fotbollsspecifika övningar. En förändring av den proprioceptiva förmågan yttrar sig genom att fotbollsspelare vid en given hastighet under isolerade fotbollsspecifika övningar minskar behovet av att se på bollen. / Aim The aim of the study was to investigate whether soccer players can develop proprioception where visual feedback systematically is eliminated in the control of the ball with their feet. Following questions have been used in the study: – Is it possible to develop the ability to control the ball without visual feedback during a training period of four weeks and 12 training sessions? – How does a soccer player’s performance (control of the ball) change with respect to improved proprioception taking into account: time (seconds), velocity (laps/minutes) and the number of times the player looks at and loses the ball respectively? Method In total 20 participants from an elite boys’ team were chosenand matched into an intervention- and a control group before the training period to ensure each group’s representation should be equal. The intervention group consisted of 12 players, average age ± standard deviation (± SD) were12.2 (± 0.2) years. The control group consisted of 8 players, average age 12.0 (± 0.7) years. The intervention group has during a four week period performed four different specificexercises consisting of warm up including dribbling and passing, slalom, ball control in a box frame and small-sided games. In order to reduce the test learning effect, the participants performed an introduction session before the pre-test. A test and retest as well as a training efficiency measurement were performed during the training period. After completed training period a post-test was carried out. The intervention group was equipped with specially designed glasses during the training period, to reduce their visual feedback. All participants were equipped with a gyro to measure head angles within the sagittal plane in the pre-test. Results The result for the exercise The Box non visual was given an improvement of 50.9 % for the intervention group from pre- to post tests (p=0.001) and effect size (ES) =1.59. The total number of ball losses was 2 and 5 times, respectively. The control group performed an improvement of 4.7 % from pre- to post tests (p=0.306, ES=0.19). The total number of ball losses was 2 and 4 times respectively. The result for the exercise Slalom non-visual for the intervention group was given an improvement of 24.9 % (p=0.004, ES=1.09). The control group was decreased with 12.6 % (p=0.105, ES=0.55). The total number of ball losses for the intervention group was 15 and 8 times, respectively. The total number of ball losses for the control group was 5 and 3 times, respectively. The total number of ball gazes for the intervention group was 18 and 9 times, respectively. The total number of ball gazes for the control group was 10 and 3 times, respectively. Conclusions It is possible to develop the proprioception by systematically limit the visual feedback through control of the ball with your feet at isolated and football specific exercises. A change in the proprioceptive ability is expressed by soccer players having reduced needs of looking at the ball during isolated soccer specific exercises at a given velocity.

The affordability and availability of fast motion cameras presents an ideal opportunity to build computer systems that create real-time feed- back loops. These systems can enable users to learn at a faster rate than traditional systems, as well as present a more engaging experience. In this dissertation, I document the development and evaluation of a real- time audio and visual feedback system for geometric poi manipulation. The goal of the system is to present an experiential and objectively su- perior learning tool when compared to traditional learning techniques in the object manipulation community. For the evaluation, I conduct an experiment that compares the feedback training system with traditional learning techniques in the object manipulation community. The results suggest that the feedback system presents a more engaging experience than traditional mirror feedback training, and conclude that further re- search is warranted.

Master of Applied Science / The aim of this investigation was to investigate the effects of computer-based visual feedback in the teaching of singing. Pitch accuracy, a readily-measured parameter of the singing voice, was used in this study to gauge changes in singing for groups with and without visual feedback. The study investigated whether the style of feedback affects the amount of learning achieved, and whether the provision of concurrent visual feedback hampers the simultaneous performance of the singing task. The investigation used a baseline–intervention–post-test between-groups design. Participants of all skill levels were randomly assigned to a control group or one of two experimental groups – with all participants given one hour of singing training. At intervention, the two experimental groups were offered one of two different displays of real-time visual feedback on their vocal pitch accuracy, while control participants had a non-interactive display. All sessions were recorded, and the vocal exercise patterns performed at baseline, intervention and post-test phases were acoustically analysed for pitch accuracy. Questionnaires assessed both general health and the amount of singing and music training of all participants; people in the two experimental groups were also given a further questionnaire about the visual feedback. The results indicate that visual feedback improves pitch accuracy in singing. Cognitive load related to the decoding of visual information was a factor at intervention. At post-test, the two groups who had used real-time visual feedback demonstrated marked improvement on their initial pitch accuracy. There was no significant difference between the results of participants from the two experimental groups, although the participants with some background in singing training showed greater improvement using a simpler visual feedback design. The findings suggest that a hybrid approach integrating standard singing teaching practices with real-time visual feedback of aspects of the singing voice may improve learning.

Two studies were devised to determine why the difference in manual aiming performance, between full vision and no vision, is decreased for a randomized visual feedback schedule. In study one, aiming accuracy and precision was assessed for up to four trials in the same vision condition, following a switch in visual feedback availability. In experiment one, visual feedback availability was uncertain; while in experiment two, certainty was provided. Results of both experiments revealed that the precision of the first trial immediately following the switch in visual condition was reminiscent of the trial that preceded it, even when performed under different visual conditions. For study two, the inter-trial interval was evaluated by extending the interval to five seconds. Results indicated no reminiscence effect. Overall, we suggest that when the inter-trial trial is brief, individuals rely on offline visual information from the preceding trial to plan the subsequent movement, regardless of certainty.