Importance Of Visual Feedback Research Articles

Visual feedback and self-monitoring in speech learning via hand movement

While human speech learning largely relies on perceiving sounds [Brainard and Doupe, Nat. Rev. Neurosci. 1(1), 31–40 (2000)], being able to see articulators also contributes to learning speech sounds [Gick et al. (2008), Phonology Second Language Acquisition 36, 315–328 (2000)]. However, seeing hands is not necessarily helpful for learning new hand movements [Emmorey et al., J. Memory Lang., 61(3), 398–411 (2009)]. This study investigates whether being able to see a hand, acting as a speech articulator, facilitates the learning of speech production via hand movements. Two groups of participants under different visual feedback conditions were asked to produce different vowel sequences via a system that maps hand movements to F1 and F2 of English vowels [Liu et al., Can. Acoust. 48(1) (2020)]. The results suggest that visual feedback contributes to the speed of speech learning and reaching vowel targets more accurately via hand movements. This study provides insight on the importance of visual feedback in monitoring speech, and supports the view that monitoring speech articulators visually can accelerate speech learning.

Differences in motor control of an aiming task in different group ages of the elderly

Abstract Aims: This study aimed to investigate how different age groups of older adults perform and control movements in a goal-directed aiming task and the importance of visual feedback during these movements. Methods: Participants included 22 old adults, divided in two age groups: younger (60-70 yr) and older (80-90 yr). Subjects performed the task in a condition with vision and in a condition where vision was deprived. Results: In the vision condition, younger subjects showed smaller movement and reaction times, smaller radial errors, higher peak velocities, lower relative times to reach peak velocity than older subjects. In the vision-deprived condition the same results were found, except for radial error measure, where no significant effect for age groups was found. Conclusion: Younger subjects seemed to rely more on visual online feedback than older subjects and older subjects use other sensory sources to meet the possible deficits of information obtained by vision.

A novel method for investigating the importance of visual feedback on somatosensation and bodily-self perception

Abstract Aims Visual feedback is hypothesized to play an important role in the phantom limb condition. In this study we attempt to create an illusory experimental model of phantom limb wherein this condition is simulated by removing the visual input from the upper limb in a group of intact participants. The aim of the study is to investigate the role of visual feedback on somatosensation, nociception and bodily-self perception. Methods Using a novel mixed reality (MR) system, the visual feedback of the left hand is removed in order to visually simulate a left hand amputation on 30 healthy participants (15 females). Using a within-subject design, three conditions are created: visual amputation condition (MR with no visual input); visual condition (MR with normal vision); and a baseline condition (no MR). Thermal detection and nociceptive thresholds using method of limits are measured. Proprioception of the visually amputated hand is investigated by probing the felt hand position on a proximal-distal axis from the body. Using a questionnaire the effects of the missing visual feedback on bodily self is assessed. Results There was a clear drift in proprioception of the left hand in the proximal direction between the control and visual amputation condition (p <0.001). A decrease in cold detection was also significant between the control and visual amputation condition (p < 0.001). Finally, questions on perceptual experiences indicated that the observed proprioceptive retraction of the visually amputated hand was also felt by the participants. Conclusions Missing visual feedback greatly influences the perception of the visually amputated arm underlining the importance of visual feedback. The observed proprioceptive retraction of the hand resembles the telescoping perceptions often reported by phantom limb patients. The novel method developed for this study, is a new tool to investigate the influence of visual feedback on the relationship of bodily-self and chronic pain.

Vision at high limb velocities: The importance of visual feedback for online control at high limb velocities early in a movement

Vision at high limb velocities: The importance of visual feedback for online control at high limb velocities early in a movement

The importance of visual feedback on the accuracy of jaw and finger positioning in man

The anatomical position of the mandible means that direct visual feedback is not possible. To clarify the role of visual information, several jaw- and finger-positioning tasks were designed, both in a ‘free-movement’ and an ‘isolated’ (arm or head fixed) state, with or without a visual feedback display of the target position. The subjects had to position the mandible or the index finger of the preferred hand on to a movable metal bar and to maintain a defined position coinciding with the target level provided on an oscilloscope screen. The position signal was tape recorded and computer analysed off-line. Digital filtering differentiated between the drift and the oscillations around the target (root mean square). The results demonstrated a lack of precision in the free-movement, finger-positioning task after withdrawal of visual feedback. For jaw opening and closing muscles, position control was less impaired when a visual feedback display was abolished. It was suggested that the efficiency of jaw positioning is not primarily determined by visual feedback.

Skill Level and Efficacy of Effector Visual Feedback in Ball Catching

The importance of visual feedback of the catching arm in a one-handed catching task and the interaction of that feedback with skill level was investigated. 10 male and 10 female subjects were separated into skilled or unskilled groups based on previous experience. Seated subjects attempted to catch 20 balls projected from a ball-projection machine aimed near the right shoulder. During half of these trials, the subject's vision of the catching arm was prevented by a screen which still permitted viewing of the critical portion of the ball's trajectory. All trials were recorded on video to identify the catching errors as errors of position or grasping. Skilled subjects made fewer errors than unskilled subjects. Occluding vision of the catching arm resulted in more errors, specifically more position errors. This finding was true for both skilled and unskilled subjects, indicating that both groups process information, visual and proprioceptive, in a qualitatively similar fashion in this task.