Richard A. Magill

A review of the contextual interference effect in motor skill acquisition

Abstract The contextual interference effect is a learning phenomenon where interference during practice is beneficial to skill learning. That is, higher levels of contextual interference lead to poorer practice performance than lower levels while yielding superior retention and transfer performance. This rather counterintuitive effect, first demonstrated by Battig (1966) for verbal materials and later shown to be relevant to motor skill learning by Shea and Morgan (1979), has led to a considerable amount of research. In this article, we review the motor skills literature related to this effect by focusing on two research directions. First, evidence related to the generalizability of the effect is considered to identify possible parameters of the contextual interference effect. It is apparent that this effect is not applicable for learning all types of tasks and for all types of learners. Thus, task and individual characteristics are given particular consideration. Second, the explanations offered to establish what learning processes account for this effect are considered. Here, the different views proposed to explain the contextual interference are discussed along with research addressing this issue. Also, the relationship between the contextual interference effect and the practice variability hypothesis of Schmidts schema theory is explored. Finally, future research directions are suggested with the goal of providing guidelines for research to enhance our present knowledge of the contextual interference effect and its relationship to motor skill learning.

Can Forgetting Facilitate Skill Acquisition

This chapter presents a conceptual synthesis of some related, and perhaps, previously unrelated empirical research. The impetus for this chapter arises primarily from our recent explorations of the so-called “contextual” “interference” effect (Lee & Magill, 1983a, 1983b; Lee, Magill & Weeks, 1984; Magill & Lee, 1984) and specifically, the inability of current theories of motor learning to explain why this effect occurs.

Contextual Interference Effects in Learning Three Badminton Serves

Abstract This study investigated the generalizability of results of contextual interference effects by extending previous laboratory research to a field setting. Thirty female subjects (N = 30) learned three badminton serves in either a blocked (low interference), serial (mixed interference), or random (high interference) practice schedule. The subjects practiced the serves three days a week for three weeks. On the day following the completion of practice the subjects were given a retention and transfer test. Results replicated previous findings of contextual interference research by showing a significant group by block interaction between acquisition trials, retention, and transfer. The random group performed better on both retention and transfer than the blocked group. The significant trial block by contextual interference interaction also supports the generalizability of contextual interference effects, as posited by Shea and Morgan (1979), to the teaching of motor skills.

Knowledge is More than We Can Talk about: Implicit Learning in Motor Skill Acquisition

This article discusses the acquisition of knowledge about environmental regulatory features that guide the selection and execution of movements involved in performing open motor skills. First, empirical evidence related to the visual search characteristics of skilled and novice performers is considered to demonstrate that learning environmental regulatory features is an important part of performing an open motor skill. Then, the hypothesis is proposed and discussed that environmental regulatory features can, and probably should, be learned implicitly, which means the features can be learned and used, even though the learner is not consciously aware of the specific characteristics of those features. This article also discusses laboratory-based experiments that provide evidence supporting this hypothesis and presents implications for developing instructional strategies and practice conditions.

Variability of Practice and Contextual Interference in Motor Skill Learning

The purpose of this study was to investigate whether learning benefits in multiple-task learning situations are a result of contextual interference or of schema enhancement related to the amount of variability in the practice session. Two experiments were designed that replicated and extended the experiment reported by Wulf and Schmidt (1988). In a 2 (same vs. different relative time) x 2 (blocked vs. random practice schedule) design, 48 right-handed subjects were randomly assigned to one of four experimental conditions. A tapping task was employed that required a right-handed tap of three small brass plates arranged in a diamond pattern. Each segment had a specific time requirement. Target times and response times were provided on a computer screen directly in front of the subject. Each subject participated in two acquisition sessions (i.e., 198 practice trials) and was tested for learning on several different retention and transfer tests. In Experiment 2, a control group was added that received no acquisition phase. Results of both experiments showed a typical contextual interference effect, with depressed scores by the random groups during acquisition but significantly better scores than the blocked groups on several retention and transfer tests. Certain characteristics of the tests were found to influence the demonstration of the practice schedule effects. These results were consistent with predictions from Magill and Hall (1990) that the learning benefits of contextual interference are more likely to occur when skill variations are from different classes of movement and that the amount of variability in practice is more influential when the to-be-learned tasks are parameter modifications of the same generalized motor program.

Effects of Tyrosine, Phentermine, Caffeine D-amphetamine, and Placebo on Cognitive and Motor Performance Deficits During Sleep Deprivation

Abstract Cognitive and motor performance are critical in many circumstances and are impaired by sleep deprivation. We administered placebo, tyrosine 150 mg/kg, caffeine 300 mg/70 kg, phentermine 37.5 mg and d-amphetamine 20 mg at 15.30 h following overnight sleep deprivation and compare their effects on cognitive and motor performance in healthy young men. Tests of visual scanning, running memory, logical reasoning, mathematical processing, the Stroop task, four-choice serial reaction time, time wall take, pursuit tracking, visual vigilance, Trails (B) task and long-term memory were evaluated at standardized intervals before, during and after sleep deprivation and drugs. Performance decrements with sleep deprivation occurred in visual scanning, running memory, logical reasoning, mathematical processing, the Stroop test, the time wall test, tracking and visual vigilance. Interestingly, with sleep deprivation some tests improved and others did not deteriorate. Improvements with medication following sleep deprivation were seen in running memory, logical reasoning, mathematical processing, tracking and visual vigilance. Although less effective than d-amphetamine, tyrosine improved performance on several tests. We conclude that all drugs tested improved at least some aspects of cognitive and motor performance after sleep deprivation. As a naturally occurring amino acid, and thus amenable to nutritional strategies, tyrosine may deserve further testing.

The Influence of Augmented Feedback on Skill Learning Depends on Characteristics of the Skill and the Learner

Augmented feedback is a common component of the communication between instructor and student in skill learning. In this article, the argument is made that the effective use of augmented feedback depends on understanding the various effects of augmented feedback on skill learning and the conditions characterizing the occurrence of each effect. Four distinct relationships between augmented feedback and skill learning are presented: Augmented feedback is necessary for learning some skills; it is not needed to learn some skills; for some skills it enables the learner to acquire the skill faster achieve a higher level of performance than would be possible without and it can be provided in such a way that it hinders skill learning. These four relationships are also discussed in terms of their implications for skill instruction.

The Contextual Interference Effect for Skill Variations from the Same and Different Generalized Motor Programs

Magill and Hall (1990) hypothesized that the contextual interference (CI) effect is found only when task variations to be learned are governed by different generalized motor programs (GMPs). The present experiments examined their hypothesis by requiring subjects to learn variations of a tapping task that had either different (Experiment 1) or the same (Experiment 2) relative timing structure. In each experiment, subjects (N = 36) performed 270 acquisition trials with knowledge of results (KR) in either a blocked or a serial order. One day later, subjects performed 30 retention trials without KR. In data analyses, errors due to parameter modifications were dissociated from errors due to GMP construction to examine which process was responsible for the CI effect. In both experiments, parameter learning created a CI effect while GMP learning failed to produce a CI effect. In the light of these findings, a modification is proposed to the Magill and Hall (1990) hypothesis that takes into account these distinct processes in motor learning.

Preparation and Control of Rapid, Multisegmented Responses in Simple and Choice Environments

Research investigating the preparation and control of rapid, multisegmented responses typically has assumed complete programming of the response occurring prior to movement initiation and has made use of a simple reaction time (RT) paradigm. A notable exception is Rosenbaums work which proposed the Hierarchical Editor (HED) model that is specifically directed toward the control of movements in the choice environment. The purposes of this study were to investigate the assumption of complete programming prior to movement initiation and to compare predictions of the HED model with other programming models. Three experiments are reported in which subjects were required to tap either one, two, or three plates as rapidly as possible in either a simple or choice RT situation. The results were very consistent in these experiments even with several modifications in apparatus and methodology. Of particular interest were effects of movement complexity on RT and movement time (MT) for the first and second segments of the movement (M1 and M2). Choice RT (CRT) results consistently showed no increases in RT as the number of movement segments increased but showed significant increases in M1. For simple RT situations, however, there were small but consistent increases in RT as well as increases in M1 with increases in the number of movement parts. For both CRT and SRT results, small but nonsignificant increases were noted for M2. These results provide evidence for incomplete programming prior to response initiation. Although the SRT data can be accommodated by Henrys theory, the HED model appears to offer the best overall fit for the results.

The Contextual Interference Effect in Parameter Modifications of the Same Generalized Motor Program

This study extended previous work (Sekiya, Magill, Sidaway, & Anderson, 1994) by examining whether the contextual interference (CI) effect could be found when task variations were controlled by the same generalized motor program (GMP) but differentiated on the basis of overall force parameter modifications. A subsidiary aim of this study was to determine how the amount of practice influenced the CI effect. During 2 acquisition sessions and 2 retention sessions, participants (N = 24) performed 3 task variations in either a blocked (low CI) or serial (high CI) condition. The task variations shared the same relative force structures but differed in the amount of overall force that had to be produced. Analysis of a general error measure revealed a strong CI effect, indicating that overall force parameter modifications of the same GMP created the CI effect. Analyses of various dependent measures, which dissociated GMP from parameter components with regard to force characteristics, revealed that parameter learning, but not GMP learning, was enhanced by high CI practice. No CI effect occurred in any aspect of timing characteristics. The amount of practice used in the present study did not influence the efficacy of the CI effect.