Effects of contextual interference on learning technical sports skills.

The effects of contextual interference on learning skills of volleyball (volley, bump, serve) are influenced by the scheduling of actual practice sessions: the activities can be proposed in a repetitive practice schedule (blocked practice) by continuously repeating the same task (low interference) or in random practice schedules by performing more tasks or variations of one same activity (high interference). High contextual interference, even though causing immediate limited performance, leads to superior performance on retention and transfer tests. Four experimental groups (13 students each) were placed in conditions of random, blocked, serial, and serial with high interference practice for 8 meetings (2 tests and 6 practice). Analysis yielded significant differences among the groups on a transfer test (long transfer) for the serve, so results in this instructional setting are partially in line with those generally found in laboratory experiments.     

Associative interference with taste aversions after contextual discrimination learning

In two experiments, rats were first given discriminative training with two distinctive contexts, such that a flavor was paired with lithium chloride (LiCl) in one context, alternating with presentations of the flavor alone in another context. Contextual control of the fluid ingestion was observed in that rats reduced the fluid intake in the LiCl-paired context but drank the solution in the context never paired with lithium. Having learned this discrimination, the rats were now given a second flavor in their home cage before being injected with LiCl and transferred to the previously lithium-paired context. In Experiment 1, the acquisition of an aversion to the novel flavor was blocked when this flavor and the contextual cues are conditioned as a compound. In Experiment 2, the blocking effect and the conditional control over fluid consumption were abolished when the associative strength of the LiCl-paired context had been extinguished by exposing the animals to water in the contexts after discriminative training. These results are interpreted as evidence that context dependency of conditioned taste aversions is mediated by a summative effect of the context–LiCl and flavor–LiCl associations.     

Memory consolidation and contextual interference effects with computer games

Some investigators of the contextual interference effect contend that there is a direct relation between the amount of practice and the contextual interference effect based on the prediction that the improvement in learning tasks in a random practice schedule, compared to a blocked practice schedule, increases in magnitude as the amount of practice during acquisition on the tasks increases. Research using computer games in contextual interference studies has yielded a large effect (f = .50) with a random practice schedule advantage during transfer. These investigations had a total of 36 and 72 acquisition trials, respectively. The present study tested this prediction by having 72 college students, who were randomly assigned to a blocked or random practice schedule, practice 102 trials of three computer-game tasks across three days. After a 24-hr. interval, 6 retention and 5 transfer trials were performed. Dependent variables were time to complete an event in seconds and number of errors. No significant differences were found for retention and transfer. These results are discussed in terms of how the amount of practice, task-related factors, and memory consolidation mediate the contextual interference effect.     

Effects of contextual interference, task difficulty, and levels of processing on pursuit tracking

Based on an activity questionnaire, 48 females without experience in open sports skills were selected to track a moving light beam through either a circle, square, or triangular target area on a pursuit rotor. Contextual interference was created by presenting 5 velocities in either a random or a blocked context during acquisition. Level of processing was manipulated by having half of all subjects classify acquisition velocities by a predetermined numerical code. Time-on-target (TOT) was measured after each acquisition, retention, and transfer trial. Subjects tracking the circle produced higher TOTs than those who tracked the square or triangle (which did not differ from one another) across all three phases of the experiment; blocked and random acquisition groups were not significantly different from one another in acquisition, retention, or transfer. Subjects who classified acquisition velocities and tracked the circle under the blocked acquisition context produced significantly higher retention scores than those who tracked the circle but did not classify acquisition velocities. Transfer was facilitated for subjects who tracked the triangle in a random transfer context and classified velocities during acquisition. Results were discussed as providing support for the manipulation of the level of cognitive processing during the initial stage of learning. In addition, manipulating task difficulty was discussed.     

The influence of reminder trials on contextual interference effects

Two experiments investigated the proposition of the elaboration explanation for contextual interference that more than one task is present in working memory when multiple tasks are practiced in a random schedule but that only one task is present in working memory when multiple tasks are practiced in a blocked schedule. Three motor tasks were performed as fast as possible in either a random or blocked practice schedule. At the end of practice, a reminder trial for each task was either given or not given. Acquisition performance was slower for the random practice conditions than for the blocked practice conditions. Retention performance was faster for the random practice conditions than for the blocked practice condition that did not receive a reminder trial for each task. Importantly, performance differences were not found between the random practice conditions and the blocked practice condition that did receive a reminder trial for each task. A blocked practice condition with a beneficial acquisition and reminder task order pairing performed faster during both acquisition and retention than a comparable random practice condition. Reminder trials can facilitate detailing of task characteristics, and their effectiveness is determined by the elapsed time and number of intervening tasks during acquisition and retention.     

A contextual interference account of distinctiveness effects in recognition

In this article, we report on two experiments that aimed to shed light on the memorability effect that derives from varying the uniqueness of contextual cues presented at encoding and retrieval. We sought to understand the locus of the recognition advantage for studying and testing words with nominally irrelevant features that are rarely shared with other words ("low-fan" features) as compared with features that are studied with more words ("high-fan" features). Each word was studied with one high-fan feature and one low-fan feature, but only one of the two features was reinstated at test. Recognition judgments were more accurate when the low-fan feature was reinstated than when the high-fan feature was reinstated. The data suggest that encoding cues that suffer from contextual interference negatively affect retrieval and do so by hindering recollection-based processing.     

Sex and contextual effects on children's use of interference competition

Prior research with children and nonhuman animals suggests that females engage in interference competition, in which I individual reduces another's chances of gaining access to a resource, only when resources are scarce, whereas males use it more widely. This study was designed to compare males' and females' use of interference competition in games in which resources were scarce or plentiful. Forty groups of 4 same-sex children from kindergarten or Grade 4 played the 2 games on 2 days. Grade 4 girls used less interference competition when resources were plentiful than when they were scarce. Results are useful for generating a contextually based model of the development of sex differences in competitive behavior.     

Cognitive underpinnings of contextual interference during motor learning

The reported study examined the cognitive processes underlying contextual interference (CI) in motor learning. This experiment was designed to assess the combined influence of practice schedule (blocked or random) and task similarity (similar or dissimilar) on acquisition and retention performance. Participants (N = 60) learned a set of three variations of a timing task according to a similar (900, 1000 and 1100 ms) or dissimilar parameter condition (700, 1000 and 1300 ms) with either a blocked or random practice order: this resulted in 4 experimental groups. Performance in delayed retention demonstrated a typical CI effect due to the schedule of practice for the dissimilar parameter condition with the random practice group outperforming the blocked practice group. Conversely, no blocked-random difference was found for the similar parameter condition. These findings lend support for the reconstruction hypothesis by showing that supplementing random practice with additional intertask elaboration (i.e., similar parameter condition) did not facilitate subsequent retention performance.     

Effects of contextual interference and age on acquisition, retention, and transfer of motor skill.

This experiment was designed to investigate the varying conditions of contextual interference within three age groups. 40 5-yr.-olds, 40 7-yr.-olds, and 40 11-yr.-olds practiced the task of throwing beanbags under either low contextual interference (blocked practice), high contextual interference (random practice), or medium contextual interference (combined practice). All subjects performed 30 acquisition trials, 12 retention trials and 6 transfer trials. Analysis indicated that only the 7-yr.-old subjects differed in their performance in the various practice groups. As hypothesized and suggested by developmental theories, the combined and blocked practice groups acquired the task better. On the other hand, the 5- and 11-yr.-olds did not differ in performance in the different practice groups. Whether this is associated with difficulty of the task or the length of practice can be assessed in further study. Contextual interference in different age groups needs further investigation.     

Task interference from prospective memories covaries with contextual associations of fulfilling them

One of the current issues in the field of prospective memory concerns whether having an intention produces a cost to other ongoing activities (called task interference). The evidence to date suggests that certain intentions held over the shorter term do interfere with other tasks. Because the cumulative effect of such costs would be prohibitively expensive in everyday life, the present study examined one means by which that interference may be reduced. Participants who formed a specific association to fulfilling an intention in a future context did not exhibit task interference over the intervening period until that context was encountered. This outcome was observed with both an event-based and a time-based prospective memory task. The results suggest that associating intention fulfillment with a specific context can eliminate task interference, and they emphasize the importance of studying intentions that are linked to future contexts versus those that are not.     

Delayed alternation in the rat: Effect of contextual stimuli on proactive interference

The effect of contextual stimuli on proactive interference in the rat was investigated in three experiments. The task was a modified delayed alternation procedure in which the rat was initially forced to one side of a T maze (the interfering forcing) followed by a forcing to the opposite side (the target forcing). A free choice run followed the target forcing in which a turn in either direction could be made. In order to obtain reinforcement on the free choice run, the rat was required to turn in the direction opposite that of the target forcing (i.e., in the same direction as the interfering forcing). Manipulation of the context prevailing during the interfering forcing, target forcing, and free choice runs revealed that free choice accuracy was (a) greater when the interfering and target forcings were conducted in different contexts than when they were conducted in the same context and (b) influenced only slightly, if at all, by whether the free choice context coincided with that prevailing during the interfering forcing or with that prevailing during the target forcing.     

Developmental differences in the impact of contextual factors on susceptibility to retroactive interference

The influence of contextual similarity on children’s recognition memory performance was examined using a retroactive interference paradigm. In the study, 9- and 12-year-olds were randomly assigned to one of two contextual conditions. In both conditions, target and interfering information were presented in distinctive contexts by using different modalities (pictures and words, respectively). However, in one condition the test was presented in the same context as the target information (picture–word–picture [PWP] condition), whereas in the other condition the test was presented in the same context as the interfering information (picture–word–word [PWW] condition). Performance in these conditions was compared with performance in a noninterference control condition (picture–word [P-W]). As predicted, overall recognition performance in the PWP condition was significantly better than in the PWW condition. However, whereas in the PWP condition there was no age difference in performance, in the PWW condition the 12-year-old group produced significantly more hits and fewer false alarms than the 9-year-old group. The theoretical implications of the results are discussed in reference to the effortful engagement of developmentally dependent executive control processes.     

High levels of contextual interference enhance handwriting skill acquisition

The authors conducted 3 experiments to examine whether introducing high levels of contextual interference is useful in handwriting skill acquisition. For all experiments, elementary school students (Ns = 44, 50, and 78, respectively) were randomly assigned to 1 of 2 practice schedules-blocked or random practice-in the acquisition phase. In the blocked condition, each of 3 letters (h, a, and y) or (in Experiment 1) symbols was handwritten 24 times consecutively. In the random condition, each letter (or symbol) was practiced 24 times, but in an intermixed, unsystematic sequence. Overall, the results showed that the random practice schedule leads to enhanced retention and transfer performance of handwriting skill acquisition.     

The role of interference produced by conflicting associations in contextual control

In 2 experiments, participants completed a computer task in which they judged the probability of outcomes occurring (e.g., flowers growing, a bug infestation) given cues (e.g., treatment of soil with a fictitious garden product). In each 2-phase experiment, cue X was associated with 1 outcome in Phase 1 and with a 2nd outcome in Phase 2. When the outcome in Phase 1 (e.g., X led to a bug infestation) was replaced in Phase 2 (e.g., X led to flowers growing), contextual control was observed (Experiments 1 and 2). Information learned in each phase was less likely to be retrieved when the cue was tested in a context different from the 1 where training occurred. When the 2nd outcome did not conflict with information acquired in the 1st phase (e.g., X led to flowers and bugs), no contextual control was observed (Experiment 2). Acquiring a 2nd association to X resulted in contextual control only when it conflicted with an association learned earlier. The authors discuss the role of interference produced when conflicting information is acquired in establishing contextual control.     

Order of a 'uniform random' presentation on contextual interference in a serial tracking task

The purpose of the present study was to examine the effect of order of a 'uniform random' presentation on contextual interference in a serial tracking task. Subjects (N=48) were randomly assigned to either a random condition or a blocked condition in the acquisition phase, in which they learned three patterns of serial tracking tasks. Subjects performed retention and transfer trials either in a blocked or a 'uniform random' order. Analysis indicated, in comparisons of performance among conditions, 'uniform random' presentation in the acquisition phase did not improve learning in retention and transfer phases. The results are discussed with regard to both theoretical significance to contextual interference and the nature of 'uniform random' presentation.     

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.     

Effects of contextual questions on experimentally induced dysphoria

In a replication and extension of Watkins, Teasdale, and Williams (2003), a scrambled sentences paradigm was used to test whether prompting contextual processing of negative cognitive primes would limit the activation of dysphoric mood. Participants were divided into two groups and, after a dysphoric mood induction procedure, were asked to unscramble sentences that either did or did not emphasise the contextual aspects of moods. Consistent with Watkins et al., participants’ despondency decreased significantly more in the contextual group than in the neutral group. This effect could not be accounted for by variations in the way sentences were unscrambled.     

A noted on the relationship between task requirements and the contextual interference effect

Typically, tasks used in past contextual interference experiments had movement, spatial pattern, or timing requirements. The possibility exists that the blocked/random manipulation of only one of these task characteristics contributes to the contextual interference effect. The purpose of the experiment reported here was to test the impact of separate movement and timing tasks on the superior learning of random trained groups. The task for all subjects in the movement condition was to release a start button and knock over a wooden barrier. There were three movement goals to be learned. Half of the subjects in this condition practiced the three movements in a blocked schedule and half practiced them in a random schedule. The subjects in the no-movement condition estimated the same three times by holding down the start button for the appropriate duration. Similarly, these subjects were divided into random and blocked practice groups. All subjects then performed a retention test. Results showed that for the movement condition, the blocked group performed with less error than the random group during acquisition. In retention, however, the random group performed with less error than the blocked group. conversely, for the no-movement condition, there were no differences between the two practice schedule groups during acquisition or during retention for any of the dependent measures. These results indicated that experimental tasks must have some type of movement requirement in order to facilitate learning through the use of random practice schedules.