David L. Wright

Physical and Observational Practice Afford Unique Learning Opportunities

Abstract In 2 experiments, the authors studied the effectiveness of physical and observational practice on learning and the effect on learning of combining physical practice and observation, as compared with providing physical practice alone. In Experiment 1, retention and transfer performance of 30 university students after physical, observational, or no practice were contrasted. Consistent with findings from other studies, the retention results indicated that observational practice is inferior to physical practice. The transfer data indicated no differences between observation and physical practice groups. In Experiment 2, retention and transfer performance of 30 participants in physical and combined (alternating physical and observational) practice groups were contrasted. The retention results showed no differences between the combined and physical practice groups, but the combined group performed significantly better than the physical practice group on the transfer test. Those findings suggest that a combination of observation and physical practice permits unique opportunities for learning beyond those available via either practice regimen alone.

Consistent and Variable Practice Conditions: Effects on Relative and Absolute Timing

Abstract The authors conducted the present experiments to resolve the discrepancy between studies in which relative-timing learning has been found to be enhanced by consistent practice conditions and contextual interference experiments in which relative-timing learning has been found to be enhanced more by random practice than by blocked practice. There were 40 participants in Experiment 1 and 48 in Experiment 2. The results of Experiment 1 extended previous findings: The learning of the relative-timing pattern was systematically enhanced by the degree to which the practice conditions promoted movement consistency (constant > blocked > serial > random). Experiment 2 provided evidence that the discrepancy between the relative-timing effects in the 2 groups of studies was a product of the way in which relative-timing goals and feedback were presented. When the feedback was presented as segment times, random practice resulted in generally more stable relative-timing patterns during acquisition than blocked practice did. Thus, in both experiments, the learning of the relative-timing pattern was enhanced by more stable relative-timing conditions during acquisition. Absolute-timing learning, as indexed by the transfer tests, was enhanced by serial or random practice as compared with constant or blocked practice, and was relatively unaffected by feedback conditions directed at the relative-timing pattern. In terms of motor programming theory, those findings are taken as additional evidence for the disassociation of memories supporting generalized motor program (GMP) performance, as indexed by relative timing, and parameter performance, as indexed by absolute timing.

An assessment of the attention demands during random- and blocked-practice schedules

The reported study used the dual-task methodology to assess the attention demands associated with high and low contextual interference (CI) practice environments. Two specific issues were addressed. First, is there a difference in the attention demands during random and blocked schedules of practice? Second, what is the time course of any differential attention demands that emerge during random and blocked training? In order to address these questions two specific temporal loci were probed during practice: a pre-response interval and the inter-trial interval. It was assumed that the pre-response interval contained the reconstructive activity that is central to the reconstruction position. In contrast, the inter-trial interval has been interpreted in previous work to be the interval in which critical intra- and inter-item processing is performed during random practice. The data revealed a typical CI effect for the primary key-pressing task. Specifically, blocked-practice participants displayed superior performance during training but performed less well than the random-practice individuals at the time of retention. The poorer acquisition performance of the random practice participants was associated with higher cognitive demand during both the pre-response and the inter-trial intervals than that of individuals assigned to blocked practice. The greater attention demands for random-practice individuals are discussed with respect to processes that might occur in both the pre-response and the inter-trial intervals.

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.

Can Observational Practice Facilitate Error Recognition and Movement Production

Abstract Two experiments are reported that examined the usefulness of observational learning for acquiring both error detection and movement production capabilities. In both experiments, individuals were assigned to a no-practice, physical-practice, or observational practice condition. Those assigned to a physical-practice condition acted as models for those assigned as observers. In both experiments, models were administered a random practice of three serial key-press tasks that had the same spatial pattern and same relative timing requirement but differed in the overall time goal. During the retention test, individuals provided estimates of their overall time after each trial. Data from these experiments revealed that error detection and overall time specification were similar following observation and physical practice. However, data from Experiment 2 indicated that physical practice offered an advantage beyond that afforded via observation, with regard to acquiring the appropriate relative time pattern. These data are discussed with respect to the role of observation for learning movement recognition and production processes.

The Contribution of Elaborative Processing to the Contextual Interference Effect

This study examined the influence of supplemental intertask and intratask processing on the retention of three motor sequences practiced in conditions of high and low contextual interference. Subjects practiced in either a blocked or random practice format and experienced additional intratask processing, intertask processing, or no additional processing. Each of three movement sequences were practiced for 18 trials. The subjects were required to perform the sequences as fast and as accurately as possible. Retention performance and recall of the movement sequences were assessed after a 21-day retention interval. The results replicated those of Wright (1991), indicating a benefit for individuals engaging intertask processing during a low contextual interference practice condition. Furthermore, supplementing random practice with additional intertask processing not only slowed the rate of task acquisition, but also resulted in retention performance that was significantly poorer than that exhibited by individuals exposed to random practice with no additional processing. This suggests there may be a limit to the extent of interference that can be established during practice that will lead to a facilitation in retention performance.

Summary Knowledge of Results

Summary knowledge of results (KR) involves delaying the presentation of KR until a predetermined number of trials has been completed. Schmidt, Young, Swinnen, and Shapiro (1989) found an optimal summary length of 15 trials (compared to 1, 5, and 10) and Schmidt, Lange, and Young (1990) found an optimum length of 5 trials (compared to 1, 10, and 15) for 1 and 2 kinematic degree of freedom timing tasks, respectively. Experiment 1 was designed to determine the optimal summary length for learning a simple isometric force production task. The results indicated better retention for the 16-trial summary than for 8- or 1-trial summaries. Experiment 2 was an initial attempt to determine the locus of the 16-trial summary effect. Specifically, Experiment 2 focused on the role played by both the information provided in the summary presentations and the practice per se of the first 14 trials in the 16-trial block. The results suggest KR is important to ensure response stability. However, it also appears important to restrict the subjects immediate utilization of KR. This latter requirement may potentially aid the parameterization process, resulting in a reduction in response bias.

Motor programming in apraxia of speech

Apraxia of Speech (AOS) is an impairment of motor programming. However, the exact nature of this deficit remains unclear. The present study examined motor programming in AOS in the context of a recent two-stage model [Klapp, S. T. (1995). Motor response programming during simple and choice reaction time: The role of practice. Journal of Experimental Psychology: Human Perception and Performance, 21, 1015-1027; Klapp, S. T. (2003). Reaction time analysis of two types of motor preparation for speech articulation: Action as a sequence of chunks. Journal of Motor Behavior, 35, 135-150] that proposes a preprogramming stage (INT) and a process that assigns serial order to multiple programs in a sequence (SEQ). The main hypothesis was that AOS involves a process-specific deficit in the INT (preprogramming) stage of processing, rather than in the on-line serial ordering (SEQ) and initiation of movement. In addition, we tested the hypothesis that AOS involves a central (i.e., modality-general) motor programming deficit. We used a reaction time paradigm that provides two dependent measures: study time (the amount of time for participants to ready a motor response; INT), and reaction time (time to initiate movement; SEQ). Two experiments were conducted to examine INT and SEQ in AOS: Experiment 1 involved finger movements, Experiment 2 involved speech movements analogous to the finger movements. Results showed longer preprogramming time for patients with AOS but normal sequencing and initiation times, relative to controls. Together, the findings are consistent with the hypothesis of a process-specific, but central (modality-independent) deficit in AOS; alternative explanations are also discussed.

Motor programming during practice conditions high and low in contextual interference.

Random practice has been reported to demand greater time for movement preparation during acquisition than blocked practice. The present study revealed that this could be attributed to a more complete engagement of the motor programming process during random practice. This cost, however, was localized to the motor programming subprocess that S. T. Klapp (1995) associated with organizing the internal structure of a movement chunk rather than an alternative subprocess responsible for organizing movement chunks into the correct serial order. The more thorough employment of motor programming during acquisition by random practice participants resulted in a more efficient use of this planning operation during retention, as well as more accurate movement reproduction. These data support the claim that practice conditions high in contextual interference support improvements in both movement preparation and memory strength.

The role of intertask and intratask processing in acquisition and retention of motor skills.

This study examined the role of intratask and intertask processing on retention of three motor skills acquired in a practice condition invoking low contextual interference. Forty-eight subjects were randomly assigned to four experimental conditions. All conditions experienced blocked practice, which was supplemented with either intertask processing, additional intratask processing, or no additional processing. Acquisition consisted of 18 trials on each of three barrier knock-down tasks. Retention performance was assessed after a 10-min filled retention interval. Results indicated that providing the opportunity to engage in intertask processing not afforded by the acquisition practice schedule enhanced access, implementation, and memorability of movement action plans. In contrast, whereas supplemental intratask processing did not appear to interfere with acquisition performance achieved when experiencing blocked practice, it did little to enhance subsequent retention performance.