The goal of the present investigation was to explore the putative contributions of feedforward- and feedback-based processes in the control of memory-guided reaching movements. Participants (N = 4) completed an extensive number of reaching movements (2700) to 3 midline targets (20, 30, 40 cm) in 6 visual conditions: full-vision, open-loop, and four memory-guided conditions (0, 200, 400, and 600 ms of delay). To infer limb control, we used a regression technique to examine the within-trial correspondence between the spatial position of the limb at peak acceleration, peak velocity, peak deceleration, and the ultimate movement endpoint. A high degree of within-trial correspondence would suggest that the final position of the limb was largely specified prior to movement onset and not adjusted during the action (i.e., feedforward control); conversely, a low degree of within-trial correspondence would suggest that movements were modified during the reaching trajectory (i.e., feedback control). Full-vision reaches were found to be more accurate and less variable than open-loop and memory-guided reaches. Moreover, full-vision reaches demonstrated only modest within-trial correspondence between the spatial position of the limb at each kinematic marker and the ultimate movement endpoint, suggesting that reaching accuracy was achieved by adjusting the limb trajectory throughout the course of the action. Open-loop and memory-guided movements exhibited strong within-trial correspondence between final limb position and the position of the limb at peak velocity and peak deceleration. This strong correspondence indicates that the final position of the limb was largely determined by processes that occurred before the reach was initiated; errors in the planning process were not corrected during the course of the action. Thus, and contrary to our previous findings in a video-based aiming task, it appears that stored target information is not extensively (if at all) used to modify the trajectory of reaching movements to remembered targets in peripersonal space.
Matthew Heath, David A. Westwood and Gordon Binsted
Gabriel Andrade Paz, Lohanne Almeida, Larissa Ruiz, Sabrina Casseres, Giovanna Xavier, João Lucas, Haroldo Gualter Santana, Humberto Miranda, Scott Bonnette and Jeffrey Willardson
, feedback is a fundamental tool for the acquisition and performance of motor skills and may be the most efficient form of training available. Indeed, the use of feedback has been shown to be highly effective in altering maladaptive biomechanical patterns and in optimizing lower-limb movements. 7 – 11 For
Steven J. Petruzzello and Charles B. Corbin
Research has suggested that females lack self-confidence in their abilities to perform in certain physical activity situations. This "situational vulnerability," however, is not characteristic of all age levels. The present research was designed to determine if situational vulnerability was characteristic of college-age females and to determine if postperformance feedback would enhance self-confidence. Further, the research was designed to determine if feedback-enhanced self-confidence would generalize to a different task. In Study 1, males and females (N=381) rated the gender appropriateness of several motor tasks and made confidence ratings. In Study 2, high and low confidence college-age women (N=69) were tested to determine if feedback increased confidence on a gender-neutral task.. Subjects were then tested for confidence after performing a different task to determine if feedback-produced confidence differences were enduring. The results indicated that both tasks were rated as gender-neutral, but college-age females lacked confidence when compared to males. Feedback did improve confidence for low confidence females, but this feedback-enhanced self-confidence did not generalize to a different motor task. It is suggested that a fourth factor, namely lack of experience, be added to Lenney's (1977) situational vulnerability hypothesis as a factor likely to affect female self-confidence.
Suzete Chiviacowsky and Helena Thofehrn Lessa
Granting learners autonomy over certain aspects of the practice context—for example, by providing them with the opportunity to choose when to receive augmented feedback or observe a model—has been consistently shown to facilitate the acquisition of motor skills in several populations. However, studies investigating the provision of autonomy support to older adults remain scarce. The purpose of the present experiment was to investigate the effects of providing choice over feedback on motor learning in older adults. Participants were divided into two groups, choice and no-choice, and practiced 36 trials of a linear positioning task. Before each block of six trials, participants from the choice group were given the choice to control, or not, when to receive feedback in the block. No-choice group participants received feedback according to the same schedule as their choice group counterparts, but they could not choose when to receive it. Two days later, participants of both groups performed retention and transfer tests. The choice group demonstrated lower absolute error scores during transfer compared with the no-choice group. The findings reinforce outcomes of previous autonomy support studies and provide the first evidence that choice over feedback can enhance the learning of motor skills in older adults.
Hooman Minoonejad, Mohammad Karimizadeh Ardakani, Reza Rajabi, Erik A. Wikstrom and Ali Sharifnezhad
variety of sources, integrate and interpret that data, and select appropriate motor commands to achieve a movement goal. 5 Unfortunately, lateral ankle sprains and CAI result in feedback and feedforward neuromuscular control alterations. 6 Of particular interest are the altered muscle activity levels
Michael J. Davies, Bradley Clark, Laura A. Garvican-Lewis, Marijke Welvaert, Christopher J. Gore and Kevin G. Thompson
, environmental, or performance feedback via noninvasive and practical methods. 4 The purpose of such deception is to create uncertainty within the pacing template, causing athletes to deviate from their routine strategy. 3 However, results from a recent meta-analysis suggest that changes in pacing and
Daniel S. Kirschenbaum and Robert J. Smith
In this study, experimenters (pseudo-coaches) provided feedback that varied in valence, sequence, and amount to 50 male college students. A laboratory analogue paradigm was used that included a basketball-like underhand free throw task in which subjects first were instructed on proper technique and then took 10 baseline shots (trials) followed by 2 blocks of 20 trials each. Subjects were randomly assigned. Some interacted with a pseudo-coach who made no comments during the two experimental trial blocks (control), while others received feedback (6-8 comments per trial block) that was response-specific, emotionally oriented, and provided in one of four sequences: positive-positive, negative-negative, positive-negative, or negative-positive. Based on prior research on coach behavior and social psychological studies of interpersonal behavior, we hypothesized that both of the continuous feedback groups would show performance decrements and associated reactions to the coach and the task. These predictions were supported regarding performance and, to some extent, regarding a measure of sustained self-observation. Discussion includes interpretation of the nominally superior performance of the control group, the nonsignificant results on the subjective evaluation measures, and implications of these findings in view of external validity criteria and prior analyses in the emerging behavioral technology of coaching.
J. Atha, D. Harris, G. West and P.K. Manley
A prototype swimming tachometer is described which consists of a waterproof box housing a battery-powered electronic system linked externally to an opto-electronic velocity transducer. The device is strapped to the hips, where it monitors water flow to produce continuous measurements of two critical variables of swimming performance, namely, velocity and acceleration. These measurements are converted in real time to auditory feedback signals to the subject via an ear plug. Permanent records may be taken simultaneously as an option using a switched external line.
Silvia C. Lipski, Stefanie Unger, Martine Grice and Ingo G. Meister
Adult speakers have developed precise forward models of articulation for their native language and seem to rely less on auditory sensory feedback. However, for learning of the production of new speech sounds, auditory perception provides a corrective signal for motor control. We assessed adult German speakers’ speech motor learning capacity in the absence of auditory feedback but with clear somatosensory information. Learners were presented with a nonnative singleton-geminate duration contrast of voiceless, unaspirated bilabial plosives /p/ vs. /pp/ which is present in Italian. We found that the lack of auditory feedback had no immediate effect but that deviating productions emerged during the course of learning. By the end of training, speakers with masked feedback produced strong lengthening of segments and showed more variation on their production than speakers with normal auditory feedback. Our findings indicate that auditory feedback is necessary for the learning of precise coordination of articulation even if somatosensory feedback is salient.
Jeremy W. Noble, Janice J. Eng and Lara A. Boyd
This study examined the effect of visual feedback and force level on the neural mechanisms responsible for the performance of a motor task. We used a voxelwise fMRI approach to determine the effect of visual feedback (with and without) during a grip force task at 35% and 70% of maximum voluntary contraction. Two areas (contralateral rostral premotor cortex and putamen) displayed an interaction between force and feedback conditions. When the main effect of feedback condition was analyzed, higher activation when visual feedback was available was found in 22 of the 24 active brain areas, while the two other regions (contralateral lingual gyrus and ipsilateral precuneus) showed greater levels of activity when no visual feedback was available. The results suggest that there is a potentially confounding influence of visual feedback on brain activation during a motor task, and for some regions, this is dependent on the level of force applied.