Effects of precision of knowledge of results on performance of a gross motor coincidence-anticipation task

The purpose of the investigation was to determine the effects from three knowledge of results (KR) precision levels (qualitative; 0.10 sec, 0.001 sec) on the performance of a gross motor coincidence-anticipation task where subjects performed with visual and other sense modality input. Other variables included in the analysis were sex, movement distance, and practice over three blocks of trials. Absolute error (AE), constant error (CE), variable error (VE), and E scores (E) of the subjects from two experiments (N = 90; N = 54) were analyzed with 3 x 2 x 2 x 3 ANOVAs with repeated measures on the last two factors (feedback, sex, movement distance, blocks). Consistent finding from both experiments indicated that, for this gross motor coincidence-anticipation task, the subjects performed as accurately and as consistently when they received qualitative KR as when, in addition, they received more precise KR. Subjects performed with less error on the short as opposed to the long term distance pattern. Males performed with less error on the long movement pattern than females in Experiment 1; however, the only sex difference noted in Experiment 2, when the movement distances were shortened, was that males had a more on-time CE mean score.     

Reduced relative frequency of knowledge of results without visual feedback in learning a golf-putting task

This study examined the effects of reduced relative frequency of knowledge of results (KR) on learning to putt in golf. Participants (19 men and 15 women) putted a golf ball, stopping the ball on a line at a distance of 3.5 m from the starting position, which included an uphill portion. After a pretest, participants were assigned as they arrived in balanced order by sex to one of two groups (100% KR, 33% KR) and practiced 60 trials. Those in the 100% KR group performed the task in its natural context, while others assigned to the 33% KR were shown the location of the putted ball after every third trial. All participants then performed a posttest and two retention tests, done 10 min. and 24 hr. after the posttest. Analysis at posttest showed each group had a constant error and an absolute constant error (/CE/) less than those at pretest. Also, in the retention test conducted the following day, the constant error of the 33% KR group was less than that of the 100% KR group. Third, in the posttest and both retention tests, the /CE/ of the 100% KR group was larger than that of the 33% KR group. These results suggest that reduced relative frequency of knowledge of results is effective in learning the accuracy of the golf putt.     

Resolving a conflict between sensory feedback and knowledge of results, while learning a motor skill

In a recent study, Buekers, Magill, and Hall (1992) showed that even when verbal knowledge of results (KR) was redundant with sensory feedback, erroneous KR influenced the learning of motor skills. To determine why this occurred, we conducted two experiments. In Experiment 1, subjects performed 50 practice trials on a complex anticipation task and then performed three non-KR retention tests of 25 trials each. The results indicated that when correct KR and erroneous KR were provided alternately, subjects ignored the erroneous KR and performed according to the correct KR. Experiment 2 compared different ratios of no KR to erroneous KR. The results showed that, for low ratios (1:1 and 4:1), learning experience was similar to a condition in which erroneous KR was presented on all trials. For a higher ratio (9:1), however, learning performance was similar to performance when KR was correct on all trials or was not presented. These results are interpreted as support for the hypothesis that when two conflicting sources of information are available, the subject's degree of uncertainty about the valid source of information influences his selection of the information to guide performance.     

Effect of bandwidth knowledge of results on the learning of a grip force control task

An experiment was conducted to investigate the persistence of the effect of "bandwidth knowledge of results (KR)" manipulated during the learning phase of performing a manual force-control task. The experiment consisted of two phases, an acquisition phase with the goal of maintaining 60% maximum force in 30 trials, and a second phase with the objective of maintaining 40% of maximum force in 20 further trials. There were four bandwidths of KR: when performance error exceeded 5, 10, or 15% of the target, and a control group (0% bandwidth). Analysis showed that 5, 10, and 15% bandwidth led to better performance than 0% bandwidth KR at the beginning of the second phase and persisted during the extended trials.     

Bandwidth knowledge of results and motor learning: More than just a relative frequency effect

Motor learning is facilitated when knowledge of results (KR) is presented in accordance with a goal-centred bandwidth (i.e. when the error exceeds a tolerance limit about a movement goal). However, under different conditions of the bandwidth procedure the frequency with which KR is provided is also affected—the wider the goal-centred tolerance limits, the lower the frequency of KR. Since low-KR frequency conditions also have been shown to facilitate motor learning, it is not known whether the bandwidth KR effect is a unique phenomenon in motor learning or is simply due to differences in the frequency of KR. In the present study we partitioned the effects due to bandwidth KR from the effects due to KR frequency using a yoking procedure. Results from the acquisition performance trials indicated that bandwidth procedures exerted both error reduction and performance stabilization influences on motor behaviour that exceeded the effects of the relative frequency control procedures. Bandwidth procedures further resulted in better performance consistency during retention than the relative frequency conditions. These findings were discussed in terms of how KR about movement error and KR about the correctness of movement affect the learning of motor skill.     

Acquisition and extinction of a simple motor skill as a function of delay of knowledge of results

The present experiment demonstrates that the effects of delay of knowledge of results (KR) in a line drawing task depend upon the dependent variable which is considered and the original response tendency of the subjects. Delay of KR interfered with the acquisition of the correct response when number of correct responses is the dependent variable. When KR was omitted the immediate-KR group continued to make more correct responses than the delayed-KR group. However, there was a significant reduction in correct responses for both groups. When absolute error was the response measure there were no significant differences between immediate-and delayed-KR groups either during acquisition or extinction. Analysis of the type of response made during extinction suggested that the overshooting effect obtained by previous investigators may be typical of short responders trained under conditions of immediate reinforcement but not of those trained under delayed-KR.

Greenspoon and Foreman (1956) obtained clear cut evidence that the effectiveness of knowledge of results (KR) in a line drawing task varies inversely with the time delay between the response and KR. On the other hand, Bilodeau and Bilodeau (1958) were unable to demonstrate a similar effect in five different experiments. Bilodeau and Ryan (1960) hypothesized that the Greenspoon and Foreman findings could not be replicated and they did in fact obtain null results. However, Dyal (1965) has recently replicated the Greenspoon and Foreman results for the case of a 30 sec. delay interval.

The purpose of the present experiment is twofold: (a) to provide replication of Green-spoon and Foreman's study at the 20 sec. delay interval used by Bilodeau and Ryan, and (b) to determine the effect of elimination of KR on a simple motor response which has been formed on the basis of KR.     

Knowledge of results for motor learning: relationship between error estimation and knowledge of results frequency

The authors of the present study investigated the apparent contradiction between early and more recent views of knowledge of results (KR), the idea that how one is engaged before receiving KR may not be independent of how one uses that KR. In a 2 ×: 2 factorial design, participants (N = 64) practiced a simple force-production task and (a) were required, or not required, to estimate error about their previous response and (b) were provided KR either after every response (100%) or after every 5th response (20%) during acquisition. A no-KR retention test revealed an interaction between acquisition error estimation and KR frequencies. The group that received 100% KR and was required to error estimate during acquisition performed the best during retention. The 2 groups that received 20% KR performed less well. Finally, the group that received 100% KR and was not required to error estimate during acquisition performed the poorest during retention. One general interpretation of that pattern of results is that motor learning is an increasing function of the degree to which participants use KR to test response hypotheses (J. A. Adams, 1971; R. A. Schmidt, 1975). Practicing simple responses coupled with error estimation may embody response hypotheses that can be tested with KR, thus benefiting motor learning most under a 100% KR condition. Practicing simple responses without error estimation is less likely to embody response hypothesis, however, which may increase the probability that participants will use KR to guide upcoming responses, thus attenuating motor learning under a 100% KR condition. The authors conclude, therefore, that how one is engaged before receiving KR may not be independent of how one uses KR.     

Left-handers and right-handers compared on a motor task

Finger-tapping performance of 45 subjects of each sex and handedness combination, for a total of 180, was compared. Performance measures were speed (mean intertap interval) and regularity (standard deviation of intertap interval). Males tapped faster but not more regularly than females. The between-hand differences in performance were smaller for both measures in left-handers. When absolute magnitudes of between hand differences were compared, females showed smaller differences in regularity of tapping than males. Speed and regularity of tapping were statistically independent; both measures discriminated well between the preferred and nonpreferred hand of both handedness groups, but the differences in speed were more marked than the differences in regularity. Data on the performance of children on the same task are included for comparative purposes.     

Rats' knowledge of incorrect responses in a matching-to-sample task

The idea that rats possess some knowledge about having been incorrect when having previously made an incorrect response is proposed. A matching-to-sample task with a second choice was used to assess the hypothesis. Only if the correct lever was chosen on the second choice was the animal rewarded. Further, the second choice was offered whether the animal was initially correct or incorrect in its first choice, preventing it from "knowing" if it had been correct in its initial decision. If rats possessed some knowledge whether they had been correct or not, then the number of correct second choice responses after an incorrect first one should have been greater than chance. The current experiment provided some evidence that the rats did "know" when its choices were incorrect.     

Effects of modeling and videotape feedback with knowledge of results on motor performance

On the basis of social learning theory it can be hypothesized that information acquired through model observation can provide as rich a basis for a cognitive representation as that acquired by means of the usual KR procedure. A source of external information similar to that of model observation is videotape feedback (VTFB). Therefore, it was the purpose of this study to test the potency of these two sources of information with KR. The design was a 4 (groups) × 10 (blocks) factorial ANOVA with repeated measures on the last factor. Both immediate transfer and 48-hr retention effects were assessed. The immediate transfer analysis indicated a significant main effect for group. This effect appeared to be due to the poor performance of the VTFB group. The same effect approached significance after the 48-hr retention. Subsequent variance analysis indicated significant differences between transfer and retention within all conditions except modeling.     

H-reflexes during a motor skill acquisition task

H-reflex amplitudes were studied during the acquisition of a motor skill involving coordinated isometric plantarflexion at the ankle joints as subjects learned to trace a triangular pattern on an oscilloscope screen by controlling plantarflexion torque applied against load cells. Torque feedback was presented on a subject oscilloscope with the right foot controlling a vertical cursor and the left foot a horizontal cursor. Eleven subjects reached criterion performance. H-reflexes were recorded from the right soleus and timed to the initiation of soleus muscle activity to plantarflex the foot. Average time to complete one trial decreased from 9 sec. in the prelearning block to 4 sec. postlearning. No single learning strategy was evident as subjects varied widely in their levels of H-reflex amplitude, but during postlearning, H-reflex amplitude became consistent within subjects as tracing performance became faster and accurate.     

Repetition of a cognitive task promotes motor learning

Motor learning plays an important role in the acquisition of new motor skills. In this study, we investigated whether repetition of a cognitive task promoted motor learning. Fifty-one young adults were assigned to either the early, late, or control groups. All participants completed a mouse tracking task in which they manipulated a mouse to track a moving target on a screen. The cursor was rotated 165° in the counterclockwise direction from the actual mouse position, requiring participants to learn how to use a new tool. To determine the task performance, we calculated the distance between the cursor and target position. In addition, to assess the effects of a cognitive task on the progress of motor learning, curve fitting of the learning curves was performed for the total distance. Experiments were conducted as per the following schedule: learning day 1 (L1), learning day 2 (L2: the day after learning day 1), retention day 1 (R1: 2 weeks after learning day 1), and retention day 2 (R2: 4 weeks after learning day 1). Participants underwent mouse tracking for 20 min on L1 and L2 and for 3 min on R1 and R2. As a cognitive task, we adopted the N-back task. The early or late group performed the N-back task for 20 min before performing motor tracking task on L1 or L2, respectively. The control group did not perform the N-back task. Based on curve fitting analysis, it was observed that the rate of change for motor learning in the early group was higher than that in the control group. The retention of motor learning did not differ between all groups. Our results indicate that the repetition of a cognitive task enhanced in the early phase of motor learning of the mouse tracking task.     

Effects of reducing frequency of intrinsic knowledge of results on the learning of a motor skill

The guidance hypothesis suggests too much knowledge of results during skill acquisition can be detrimental to long-term performance. Possibly, the learner becomes dependent on augmented KR and is unable to use intrinsic feedback. This study examined this hypothesis with three groups performing a golf putting task. One group received continuous KR about ball path and final location; the other groups were deprived of specific KR on 50% or 100% of the acquisition trials. As expected, the continuous KR group performed better during acquisition, but the KR-deprived groups performed better on delayed retention trials, especially when KR was absent.     

Getting a tool gives wings: overestimation of tool-related benefits in a motor imagery task and a decision task

Two experiments examine whether people overestimate the benefits provided by tool use in motor tasks. Participants had to move different quantities of objects by hand (two at a time) or with a tool (four at a time). The tool was not within reach so participants had to get it before moving the objects. In Experiment 1, the task was performed in a real and an imagined situation. In Experiment 2, participants had to decide for each quantity, whether they preferred moving the objects by hand or with the tool. Our findings indicated that people perceive tool actions as less costly in terms of movement time than they actually are (Experiment 1) and decide to use a tool even when it objectively provides less time-based benefits than using the hands (Experiment 2). Taken together, the data suggest that people overestimate the benefits provided by tool use.     

Posture based motor planning in a sequential grasping task

Movement planning in sequential tasks is revealed by grasping postures. We explored aspects of planning a sequential drawer opening and object manipulation task with regard to arm and torso postures. We conducted a detailed kinematic analysis of joint postures at the wrist, elbow, and shoulder for a one-grasp and a two-grasp sequence of movement. The second of the two-grasp sequence was constrained (uncomfortable). We predicted that planning for the second grasp in a two-grasp sequence would influence arm, torso, and whole-body postures at the first grasp. Participants prepared for the second grasp by adjusting the posture of the elbow and shoulder and the distance they stepped to the drawer. The joint postures at the elbow and shoulder changed in the direction of the intended object grasp. These findings show that anticipatory adjustments are revealed at postures other than the end-effector and lend insight into the mechanisms of sequential movement planning.