More on assessing the retention of motor learning based on restricted information

Three days of beam walking practice improves dynamic balance control regardless of the use of haptic anchors in older adults

Balance deficits during walking increase the risk of falls in older adults. Providing haptic information through anchors improves dynamic balance control, but the benefits of practicing with anchors during walking need to be evaluated. We investigated the effect of practice with haptic anchors in the beam walking task in older adults. Twenty-five older adults participated in this study divided into 0% (G0, practice without the anchors) and 50% (G50, practice with the haptic anchors in 50% of the trials) groups. With the anchors, participants held in each hand a cable with a mass of 0.125 kg affixed to the end of the cable that contacted the ground. They walked and kept the anchors in contact with the ground such that they dragged them. Participants increased the distance walked on the beam and reduced the trunk angular acceleration after training, but this effect was independent of the anchors. The use of haptic anchors during beam walking training did not significantly affect older adults' performance and dynamic balance control. Both groups showed improvements in the post-test and 24-hr retention conditions, indicating that older adults can learn to adapt their gait to more challenging contexts.

A single high-intensity exercise bout during early consolidation does not influence retention or relearning of sensorimotor locomotor long-term memories

A single exercise bout has been found to improve the retention of a skill-based upper extremity motor task up to a week post-practice. This effect is the greatest when exercise intensity is high and exercise is administered immediately after motor practice (i.e., early in consolidation). Whether exercise can affect other motor learning types (e.g., sensorimotor adaptation) and tasks (e.g., walking) is still unclear as previous studies have not optimally refined the exercise parameters and long-term retention testing. Therefore, we investigated whether a single high-intensity exercise bout during early consolidation would improve the long-term retention and relearning of sensorimotor adaptation during split-belt treadmill walking. Twenty-six neurologically intact adults attended three sessions; sessions 2 and 3 were 1 day and 7 days after session 1, respectively. Participants were allocated either to Rest (REST) or to Exercise (EXE) group. In session 1, all groups walked on a split-belt treadmill in a 2:1 speed ratio (1.5:0.75 m/s). Then, half of the participants exercised for 5 min (EXE), while the other half rested for 5 min (REST). A short exercise bout during early consolidation did not improve retention or relearning of locomotor memories one or seven days after session 1. This result reinforces previous findings that the effect of exercise on motor learning may differ between sensorimotor locomotor adaptation and skilled-based upper extremity tasks; thus, the utility of exercise as a behavioral booster of motor learning may depend on the type of motor learning and task.

The effects of repeated retention tests can benefit as well as degrade timing performance

In this study, we examined the effects of interference and repeated retention tests by comparing groups that performed (a) one or two tests, or (b) two tests separated by interpolated tasks. The task involved pressing five keys in 925 ms. Constant error increased after Block 1 of the second test for the group completing the interpolated tasks. Variable error decreased across retention tests and was smaller for the two-test groups compared to the one-test control. Results differed from previous reports of degraded timing accuracy (Magnuson, Shea, & Fairbrother 2004), suggesting the present results may have been related to highly accurate performance during the first retention test that reflected successful initial encoding of task information.

Repeated retention testing effects do not generalize to a contextual interference protocol

Three experiments examined repeated retention testing effects in a contextual interference (CI) protocol. Retention was assessed at 10 min and 24 hr following acquisition or at just 24-hr for the one-test conditions. Experiments 1 and 2 used speeded-response key-pressing tasks. Dependent measures were total time and errors. Experiment 3 used sequential-timing tasks. Dependent measures were absolute error and absolute constant error Results revealed CI effects in each experiment. Repeated retention testing effects were not found in Experiments 1 and 3. Experiment 2 revealed superior performance by the two-test condition compared to the one-test condition. This result was qualified by possible practice effects during the 10-min test. It was concluded that repeated retention testing does not present problems for most studies of CI.

Support for an explanation of the guidance effect in motor skill learning

The authors investigated whether the knowledge of results (KR) schedule influences the extent to which intrinsic feedback is noticed and used. Fifty-six participants received KR that was either delayed over 2 trials (Delay-2) or provided directly after each trial (Delay-0) during 160 trials of an unfamiliar aiming task. No-KR retention tests were given after 80 trials and 1 min and 24 hr after the end of acquisition. After retention, all participants were questioned about their use of intrinsic feedback during practice and whether those sources changed as a function of practice. The Delay-2 group performed significantly less accurately on the 1st and last blocks of acquisition trials but showed a significantly smaller performance decline from acquisition to retention. Moreover, the Delay-2 group noticed and used a greater variety of intrinsic feedback sources and its members were more likely to report that their usage changed with practice.

Effects of repeated retention tests on learning a single timing task

The purpose of the present study was to investigate the possibility that administering an initial retention test would influence any subsequent retention tests administered to the same participants. Participants performed 40 practice trials of a four-segment key-pressing task with a movement time goal of 925 ms. Participants were then administered either two retention tests (Day 1-Day 1 group, 10 min and 20 min after practice; Day 1-Day 2 group, 10 min and 24 hr after practice; Day 2-Day 2 group, 23 hr 50 min and 24 hr after practice) or one retention test (Day 1-Control group, 20 min after practice; Day 2-Control group, 24 hr after practice). The first test had a deleterious effect on performing the second test for the Day 2-Day 2 group, which would be expected if the task representation was updated and re-encoded at the time of recall using diminished information. This finding suggests that researchers should be cautious about using repeated retention tests that are administered 1 day after practice. In addition, teachers and coaches should consider administering a test under gamelike conditions following practice of a new technique. Otherwise, performance of the new technique may be degraded or perturbed at the time of later performances.

Motor learning as a function of KR schedule and characteristics of task-intrinsic feedback

Forty participants (age range = 18-35 years) practiced 1 of 2 versions of an aiming task (with or without spring resistance). Knowledge of results (KR) was provided to them either immediately or after a delay of 2 trials. Immediate KR led to significantly more accurate performance during the 80 trials in acquisition but significantly less accurate performance on a 40-trial retention test given 24 hr after practice. In addition, the spring version of the task was performed significantly less accurately than the no-spring version on the 24-hr retention test. Most important, a significant interaction on the 24-hr retention test revealed that performance of the no-spring version of the task, when KR had been given after a 2-trial delay, was significantly more accurate than performance of the other 3 combinations of task version and KR schedule. The results suggest that KR dependency in motor skill learning is related to familiarity with task-intrinsic feedback in addition to the schedule on which KR is presented.

Goal orientation and the modeling process: an individual's focus on form and outcome

One's achievement goal orientation (e.g., task, ego) is suggested to reflect a differential focus on skill mastery and performance outcome (Duda, 1992). Goal orientation has further been suggested to be an important observer characteristic in the observational learning of motor skills (McCullagh, Weiss, & Ross, 1989). This study assessed the relationship between goal orientation and a focus on form and outcome aspects of a motor skill demonstration with college students (N = 30) having low perceived ability, knowledge, and experience in tennis. Participants viewed several videotaped demonstrations of a correctly performed tennis forehand and then visual recognition and verbal recall accuracy of form and outcome task characteristics were assessed. A canonical correlation analysis revealed a nonsignificant relationship between goal orientation and recall and recognition of form and outcome task characteristics. These results provide preliminary evidence to suggest that goal orientation may not be an important observer characteristic in the learning phase of the modeling process. Also, achievement goal orientations may not be associated with a differential focus on skill mastery or performance outcome but instead remain a reflection of divergent processes of success evaluation.