Contextual interference effects on the acquisition and retention of fundamental motor skills

This study was designed to examine the effect of three practice models (repetitions, random, and combined) on the acquisition and retention of fundamental motor skills. 54 girls in Grade 4 were randomly assigned to the three different practice groups who practiced three skills of ball rolling, racket striking, and ball kicking. All subjects received pretests posttests, and a 3-wk, retention test. Performance was significantly improved during practice in the three groups for the three skills. The repetitions group performed better than the other two groups at the end of practice. The contextual interference effect in retention was only shown for the racket-striking skill, in which the random group was significantly better than the repetitions and the combined groups. An attempt was made to attribute that specific result to the special characteristics of the striking skill in this study as an open skill with which subjects had a previous experience.     

Effects of varying force production in practice schedules of children learning a discrete motor task

The variability of practice prediction from Schmidt's Schema Theory involving transfer and retention was tested when manipulating only the performance parameter of over-all force. Children (n = 120) of two age groups performed a 15-in (39.1 cm) arm movement on a linear slide modified to allow manipulating the force required to move the car on the slide. No significant differences between the variable group and the constant practice group were found for either the 10 transfer or 5 retention trials. Mean absolute errors were ordered in favor of the constant practice group for both transfer and retention. For the first transfer trial a significant difference was found; constant practice groups performed better. This finding is contrary to predictions of schema theory as well as evidence from children as subjects.     

Contextual dependencies in motor skills

The development of contextual dependencies during motor skill acquisition was examined. Environmental context was varied along intentional and incidental dimensions. Intentional stimuli were defined as essential for achieving skilled performance, whereas incidental stimuli were defined as those that have the potential to become associated with specific tasks due to their selective presence in the learning environment. Experiment 1 demonstrated the occurrence of contextual dependencies for the learning of four-key typing sequences. Contextual dependencies were diminished in Experiment 2 when the number of keys used in the sequences was reduced. In Experiment 3, a retention condition was incorporated, in which both the intentional and the incidental stimuli were not available; this confirmed that task difficulty mediated the development of contextual dependencies. These findings are discussed with respect to the incorporation of environmental contextual stimuli with memorial representations of movement information.     

Stimulus-naming effects at different stages of motor paired-associate learning

In a combined verbal and motor paired-associate task, nonsense names and button-pushing responses were learned for three random shapes, with verbal training beginning after 3, 12, or 24 motor learning trials. Earlier studies indicated that concurrent verbal and motor learning produce a strong tendency for the naming and button-pushing responses to be learned in “consistent” pairs. According to the theoretical analysis presented, the verbal-motor consistency is explained by the development of name-button associations. It was predicted that these associations affect both motor errors and correct responses, that their effects are greater for correct responses, and that attenuation of the effects due to delay in verbal training is gr, eater for motor errors. The results are in good agreement with the predictions, and they suggest that name-button associations develop rapidly even under delayed verbal training.     

Field dependence-independence in complex motor skills

This study analyzed the relationship between field dependence-independence and complex motor skills. According to the requirements of each sporting activity, subjects' motor system can be mainly controlled through exteroceptive or proprioceptive information. Sport performances require the athlete to disembed himself, other players, or the ball from the background, and decision-making appears to require cognitive restructuring. 26 athletes (13 men and 13 women) involved in acrobatic sports (gymnastics, trampoline, half-pipe snowboard, synchronized 3-m springboard, acrobatic rock, skateboard, and free skating) and 26 athletes (13 men and 13 women) involved in individual racket sports (tennis and table-tennis) completed the Group Embedded Figures Test. Participants (at least 10 years of practice) were from 16 to 35 years of age (M=22.0, SD=3.1). No significant difference among athletes on scores for field dependence-independence was evidenced given this expertise, sex, or age. Significantly higher scores were obtained by athletes in acrobatic sports, indicating that they tended to be predominately more field-independent whereas the lower scores were obtained by tennis and table-tennis players.     

The interaction of observational learning with overt practice: effects on motor skill learning

This study explored various methods of combining observational learning via demonstration with the effects of overt practice for learning a discrete action pattern. Three groups were compared that varied by the timing of demonstration in relation to practice. An all-pre-practice demonstration group viewed 10 pre-practice videotape demonstrations of an expert performing the skill, and then engaged in practice. An interspersed demonstration group viewed one pre-practice demonstration, then initiated practice on the skill. Every three attempts, practice was halted while participants viewed another demonstration, with this pattern repeated throughout acquisition. A combination demonstration group experienced elements of each schedule by viewing five demonstrations prior to practice, then five more once practice had begun (one every three attempts) so that modeling was completed by mid-acquisition. Ratings of form and accuracy were assessed in an acquisition phase, an immediate retention test, and a 48-h retention test. Group main effects for form scores were detected in acquisition, immediate, and 48-h retention, with the combination group obtaining the highest form scores, followed by the all-pre-practice group, and finally the interspersed group. These findings suggest that several modeling exposures before practice and several more exposures in the early stages of practice were optimal for acquisition and retention of form.     

Metacognition in motor learning

Research on judgments of verbal learning has demonstrated that participants' judgments are unreliable and often overconfident. The authors studied judgments of perceptual-motor learning. Participants learned 3 keystroke patterns on the number pad of a computer, each requiring that a different sequence of keys be struck in a different total movement time. Practice trials on each pattern were either blocked or randomly interleaved with trials on the other patterns, and each participant was asked, periodically, to predict his or her performance on a 24-hr test. Consistent with earlier findings, blocked practice enhanced acquisition but harmed retention. Participants, though, predicted better performance given blocked practice. These results augment research on judgments of verbal learning and suggest that humans, at their peril, interpret current ease of access to a perceptual-motor skill as a valid index of learning.     

Contextual interference in learning precision skills

This research studied the effect of different organisations of practice (blocked and random) on the learning of three different types of throwing. 35 male students practiced three precise throws for 3 wk. Initially the subjects were separated into two groups who trained under different conditions of practice (blocked and random). All subjects improved significantly from initial performance, with both blocked practice and random practice. At the end of acquisition no differences were found between the groups. No significant differences were found on retention tests carried out 48 hr., 4 wk., and 8 wk. after the training period.     

Priming of future States in complex motor skills

The ability to anticipate future states of perceived actions is an important faculty for motor control and the generation of coordinated social interaction. Here, we studied whether the perception of a static posture of a complex movement automatically activates representations of future states of this particular movement event. We did this by using a priming paradigm with photographs of a high-jump movement. Participants judged whether a picture depicted a posture from the approach or flight phase of that movement. To evaluate expertise-dependent effects of priming, non-athletes and athletes were compared. Results revealed faster responding when prime and target pictures were assigned to the same motor response (response priming), and when the temporal order of prime and target matched the temporal order of the depicted postures in a real high jump (temporal-order priming). Whereas experts showed a temporal-order effect even within the same response category, such an effect occurred for novices only between response categories. A second experiment confirmed that these between-group differences are due to domain-specific motor expertise (i.e., high jump) rather than to general motor experiences. Altogether our results suggest that motor expertise results in a more fine-grained posture-based movement representation.     

Retrieval practice in motor learning

In this study we sought to determine whether testing promotes the generalization of motor skills during the process of encoding and/or consolidation. We used a dynamic arm movement task that required participants to reproduce a spatial-temporal pattern of elbow extensions and flexions with their dominant right arm. Generalization of motor learning was tested by the ability to transfer the original pattern (extrinsic transformation) or the mirrored pattern (intrinsic transformation) to the unpractised left arm. To investigate the testing effects during both encoding and consolidation processing, participants were administered an initial testing session during early practice before being evaluated on a post-practice testing session administered either 10 min (Testing-Encoding group) or 24 hr apart (Testing-Consolidation group), respectively. Control groups were required to perform a post-practice testing session administered after either a 10-min (Control-Encoding group) or 24-hr delay (Control-Consolidation group). The findings revealed that testing produced rapid, within-practice skill improvements, yielding better effector transfer at the 10-min testing for the Testing-Encoding group on both extrinsic and intrinsic transformation tests when compared with the Control-Encoding group. Furthermore, we found better performance for the Testing-Consolidation group at the 24-hr testing for extrinsic and intrinsic transformations of the movement pattern when compared with the Control-Consolidation group. However, our results did not indicate any significant testing advantage on the latent, between-session development of the motor skill representation (i.e., from the 10-min to the 24-hr testing). The testing benefits expressed at the 10-min testing were stabilised but did not extend during the period of consolidation. This indicates that testing contributes to the generalisation of motor skills during encoding but not consolidation.     

Response delays and the timing of discrete motor responses

A model for the timing of repetitive discrete motor responses is proposed, and a prediction of negative dependency between successive interresponse intervals is confirmed by data from a Morse key tapping task. A method that makes use of the first-order serial correlation between interresponse intervals is used to distinguish between variance due to a timekeeping process and variance in motor response delays subsequent to the timekeeper. These two quantities are examined as a function of mean interresponse interval.     

Practice makes transfer of motor skills imperfect

We investigated the practice-effects on motor skill transfer and the associated representational memory changes that occur during the within-practice and between-practice phases. In two experiments, participants produced extension–flexion movements with their dominant right arm for a limited or prolonged practice session arranged in either a single- or multi-session format. We tested the ability of participants to transfer the original pattern (extrinsic transformation) or the mirrored one (intrinsic transformation) to the non-dominant left arm, 10?min and 24?h after the practice sessions. Results showed that practice induces rapid motor skill improvements that are non-transferable irrespective of the amount of acquisition trials. Furthermore, the extrinsic component of the skill develops early and remains the dominant coding system during practice. Conversely, we found distinct between-practice memory changes: a limited practice induces an off-line development of the extrinsic component, whereas a prolonged practice session subserves the off-line development of the intrinsic component (Experiment 2). We provided further evidence that the long-term representation of the motor skill also depends on the nature of the practice session itself: the parsing of practice into multiple sessions narrows the effector-transfer capacities in comparison to a single session (Experiment 1). These findings yield theoretical and practical implications that are discussed in the context of recent motor skill learning models.