Children's initial sleep‐associated changes in motor skill are unrelated to long‐term skill levels

Sleep is considered to support the formation of skill memory. In juvenile but not adult song birds learning a tutor's song, a stronger initial deterioration of song performance over night‐sleep predicts better song performance in the long run. This and similar observations have stimulated the view of sleep supporting skill formation during development in an unsupervised off‐line learning process that, in the absence of external feedback, can initially also enhance inaccuracies in skill performance. Here we explored whether in children learning a motor sequence task, as in song‐learning juvenile birds, changes across sleep after initial practice predict performance levels achieved in the long run. The task was a serial reaction time task (SRTT) where subjects had to press buttons which were lighted up in a repeating eight‐element sequence as fast as possible. Twenty‐five children (8–12 years) practised the task in the evening before nocturnal sleep which was recorded polysomnographically. Retrieval was tested on the following morning and again 1 week later after daily training on the SRTT. As expected, changes in response speed over the initial night of sleep were negatively correlated with final performance speed after the 1‐week training. However, unlike in song birds, this correlation was driven by the baseline speed level achieved before sleep. Baseline‐corrected changes in speed or variability over the initial sleep period did not predict final performance on the trained SRTT sequence, or on different sequences introduced to assess generalization of the trained behaviour. The lack of correlation between initial sleep‐dependent changes and long‐term performance might reflect that the children were too experienced for the simple SRTT, possibly also favouring ceiling effects in performance. A consistent association found between sleep spindle activity and explicit sequence knowledge alternatively suggests that the expected correlation was masked by explicit memory systems interacting with skill memory formation.     

Moderators of Skill Retention Interval/Performance Decrement Relationships in Eight U.S. Air Force Enlisted Specialties

A robust finding in the literature on skill maintenance is that extended skill-retention intervals (SRIs) lead to decreased task performance. We investigated three potential moderators of the SRVtask performance decrement relationship: (a) degree of initial skill learning, (b) performer aptitude, and (c) degree of task difficulty. Results in eight samples of enlisted U.S. Air Force personnel (N = 1,544) generally supported a negative SRIItask performance relationship, but support for moderator effects was mixed. Implications for skill maintenance in actual work settings are discussed.     

Individual Differences in Various Parameters of Motor Learning

60 Ss practiced 6 days on the stabilometer. No reminiscence or warm-up decrement was found; loss of skill occurred from 1-day layoffs which lessened as learning progressed. A 3-component exponential equation fitted the learning trend (including relearning). Both individual differences and intra-individual variations decreased exponentially with practice, but the ratio of individual differences to mean score increased. Practice had little influence on adjacent trial rs. Between scores in any particular pair of separated trials, r decreased when increasing number of trials separated them. Averaging 8 initial and 8 final trials gave optimum learning score reliability (r = .95). Individual rates of learning were not appreciably correlated with amounts of learning (r = .23). Final performance levels could only be predicted 50% from initial skill and cumulated amounts of learning unless more than half of the total practice (i.e., more than 90% of the potential learning) had been accomplished. The pattern of zero order rs between amount of learning and initial and final skill levels differed markedly from that previously observed in learning the ladder climb.     

The effects of ageing and cognitive impairment on on‐line and off‐line motor learning

Skilled performance is a collective function of practice‐related experiences (online learning) and post‐practice memory consolidation during sleep (offline learning). This study examines the effects of ageing and cognitive impairment on the on‐ and offline learning of a point‐to‐point arm movement. In a 3‐day experiment, older adults (cognitively normal or impaired) and young adults (YAs) were randomly assigned to practice or no‐practice conditions. Changes in the dependent measures of movement time and timing error were analysed within and between conditions across days. The findings suggest that both age and cognitive function affect skill learning. YAs improved performance via both on‐ and offline learning whereas older adults with normal cognitive capacities appeared to learn the movement skill primarily in an online mode. Cognitive impairments were found to hinder both types of skill learning. Implications for motor skill acquisition and rehabilitation are briefly discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of aging on priming and skill learning.

This study examined the effects of aging on 2 kinds of implicit memory; repetition priming and skill learning. In Experiment 1, older adults showed less improvement in the skill of reading inverted words than did young adults, but priming performance did not differ for the 2 age groups. Similarly, in Experiment 2, in a partial-word identification task, skill learning was observed only for young adults, whereas there was no age difference in priming. Experiments 1a and 2a, however, showed that when older adults were presented with more perceptual information than were young adults, the age deficit in skill learning was eliminated. These results indicate that skill learning is impaired under data-limited conditions, whereas priming is unaffected under these conditions. It is proposed that the age deficit in skill learning is related to a deficit in perceptual organization and reorganization.     

The Effect of Fatigue on Learning and Performance of a Gross Motor Task

40 college males were sequentially assigned to 1 of 2 groups to examine the effects of induced physical fatigue upon the performance and learning of a gross motor task, the stabilometer. All Ss were given 32 practice trials over 3 practice sessions, with 48 hr. rest interpolated between sessions. Trials 1 and 2 were performed under control conditions (no fatigue) for both groups. The Experimental Group was then required to perform under conditions of physical fatigue during Trials 3-26. Trials 27-32 (Session 3) were performed under control conditions. The condition of fatigue was achieved on Trials 3-26 by having Ss pedal a bicycle ergometer until a heart rate of 180 beats/min was attained prior to each trial. The Control Group cancelled vowels. The results indicated that physical fatigue was detrimental to the performance and learning of the Experimental Group.     

Qualitative and quantitative change in the dynamics of motor learning

The experiments examined qualitative and quantitative changes in the dynamics of learning a novel motor skill (roller ball task) as a function of the manipulation of a control parameter (initial ball speed). The focus was on the relation between the rates of change in performance over practice time and the changing time scales of the evolving attractor dynamic. Results showed 3 different learning patterns to the changes in the dynamics as a function of practice that were mediated by the initial ball speed. Only participants who learned the task showed a bifurcation in coordination mode that was preceded by enhanced performance variability. The observed multiple time scales to motor learning are interpreted as the products of the dynamical stability and instability realized from (a) the continually evolving landscape dynamics due to bifurcations between attractor organization and (b) the transient phenomena associated with moving toward and away from fixed-point dynamics.     

Role of Verbal Working Memory in Complex Skill Acquisition

Although research has shown that general cognitive ability is related to performance during the initial stage of skill acquisition, empirical evidence is needed to increase understanding of the primary abilities responsible for the relation. We propose that verbal working memory is related to initial skill acquisition performance based on cognitive activities people enact when learning complex skills. After completing a general cognitive ability measure and a test of verbal working memory, 120 undergraduate students performed a complex computer simulation. The working memory test accounted for a meaningful amount of performance variance after statistically controlling for the general cognitive ability measure. These data suggest that tasks depending heavily on the activation of multiple knowledge structures may be understood in terms of individual differences in working memory.     

Contextual interference effect on acquisition and retention of pistol-shooting skills

The effects of contextual interference on learning pistol-shooting skills in a natural training environment were examined. The shooting skills consisted of three "stages" with different requirements for the skill variations commonly used in the field. 12 participants were randomly assigned into one of two practice conditions, blocked vs serial. Following a 20-min. safety and skill instructional session, Blocked group practiced 10 trials in a row at each stage, while Serial group performed 5 trials in a row for each of the three stages and then repeated the cycle. Both groups completed a total of 30 practice trials over the three stages. A 10-min. rest interval was provided prior to a retention test which included 9 trials (3 trials at each stage in a blocked format). Results based on the data of Stage III, the most complex skill among the three stages, showed a pattern consistent with previous findings that practicing in the serial schedule depressed performance during initial training but maintained the performance better at retention, relative to the blocked practice.     

Skill, strength, handedness, and fatigue

Thirty male subjects, 20 of whom were self-classified left-handers and 10 right-handers, were tested on a grip-strength task and a handwriting task with each hand, both under normal conditions and in a situation of induced experimental fatigue. On the basis of questionnaire scores, the left-handers were sub-divided into two groups comprising the 10 most left-handed and the 10 least left-handed subjects. The test of grip strength showed a small but significant deterioration in performance of both hands from fatigue. With the handwriting task, a similar significantly adverse effect of fatigue was recorded for all groups as well as a large significant difference in performance between the preferred and nonpreferred hands under normal conditions, which decreased under fatigue. An explanation of these differential effects is discussed in terms of the greater efficiency of the preferred hand in the highly developed skill of handwriting.     

Speech and nonspeech sequence skill learning in adults who stutter

Two studies compared the speech and nonspeech sequence skill learning of nine persons who stutter (PWS) and nine matched fluent speakers (PNS). Sequence skill learning was defined as a continuing process of stable improvement in speed and/or accuracy of sequencing performance over practice and was measured by comparing PWS's and PNS's performance curves of accuracy, reaction time, and sequence duration, as well as retention and transfer. In experiment one, participants completed a 30-trial finger tapping sequence and in experiment two, a 30-trial read-aloud sequence of nonsense syllables. Significant between-group differences were found in the speed of sequencing performance after practice, and on retention and transfer tests. These results partially supported the inference that PWS demonstrated differences in early stages of sequence skill learning compared to PNS. EDUCATIONAL OBJECTIVES: As a result of this activity the participant will be able to: (1) define skill learning and the important indicators of skill learning; (2) summarize the reviewed literature concerning the performance of PWS on speech and nonspeech sequencing tasks over practice; and (3) explain the implication of reaction time differences over practice between PWS and PNS.     

Age-related decline of sleep-dependent consolidation

Sleep-dependent memory consolidation is observed following motor skill learning: Performance improvements are greater over a 12-h period containing sleep relative to an equivalent interval without sleep. Here we examined whether older adults exhibit sleep-dependent consolidation on a sequence learning task. Participants were trained on one of two sequence learning tasks. Performance was assessed after a 12-h break that included sleep and after a 12-h break that did not include sleep. Older and younger adults showed similar degrees of initial learning. However, performance of the older adults did not improve following sleep, providing evidence that sleep-dependent consolidation is diminished with age.     

The self: Your own worst enemy? A test of the self-invoking trigger hypothesis

The self-invoking trigger hypothesis was proposed by Wulf and Lewthwaite [Wulf, G., & Lewthwaite, R. (2010). Effortless motor learning? An external focus of attention enhances movement effectiveness and efficiency. In B. Bruya (Ed.), Effortless attention: A new perspective in attention and action (pp. 75–101). Cambridge, MA: MIT Press] as a mechanism underlying the robust effect of attentional focus on motor learning and performance. One component of this hypothesis, relevant beyond the attentional focus effect, suggests that causing individuals to access their self-schema will negatively impact their learning and performance of a motor skill. The purpose of the present two studies was to provide an initial test of the performance and learning aspects of the self-invoking trigger hypothesis by asking participants in one group to think about themselves between trial blocks—presumably activating their self-schema—to compare their performance and learning to that of a control group. In Experiment 1, participants performed 2 blocks of 10 trials on a throwing task. In one condition, participants were asked between blocks to think about their past throwing experience. While a control group maintained their performance across blocks, the self group's performance was degraded on the second block. In Experiment 2, participants were asked to practice a wiffleball hitting task on two separate days. Participants returned on a third day to perform retention and transfer tests without the self-activating manipulation. Results indicated that the self group learned the hitting task less effectively than the control group. The findings reported here provide initial support for the self-invoking trigger hypothesis.     

Retention of bilateral performance as a function of practice order

The purpose of this study was to investigate the effect of practice order and initial performance hand on the bilateral retention of a simple tracking skill for 44 undergraduate volunteers. The apparatus was a Lafayette Model 30014 photoelectric rotary pursuit. The circle template was employed with rotation speed set at 20 rpm. Subjects were given 20-sec. trials and required to reach a criterion of 70% time on target twice in succession with both hands. For original practice, subjects were randomly assigned to one of four practice groups: preferred serial, non-preferred serial, preferred sequence and non-preferred sequence. Subjects' performance was recorded as the number of trials required to achieve criterion for both hands. One month later subjects were retested and scored in the same manner. A 2 X 2 X 2 analysis of variance with repeated measures on the last factor was used to determine the effects of initial hand, order of practice, testing periods, and the appropriate interactions. The results indicated that subjects' performance for the two testing periods differed significantly; retest was superior. Order of practice was significant and the sequential order more efficient during both learning and retest.     

Learning from Our Mistakes: Error Management Training for Mature Learners

This research explored the effects of training goal (learning goal vs. performance goal) and training type (error management vs. error avoidance) on word processing skill acquisition with older workers. Sixty-seven participants were randomly assigned to one of four experimental conditions and attended two interactive tutorial training sessions. Results indicated that error management training lead to significantly higher performance test scores, learning quiz scores, and requests for assistance compared to error avoidant training. Additionally, learning goals generated significantly higher performance test scores and intrinsic motivation levels relative to performance goals. Other applications of error management training are discussed.     

The relationship between initial errorless learning conditions and subsequent performance

This experiment explores a suggestion by [Maxwell, J.P., Masters, R.S.W., Kerr, E., Weedon, E. (2001). The implicit benefit of learning without errors. Quarterly Journal of Experimental Psychology A 54, 1049-1068] that an initial bout of implicit motor learning confers beneficial performance characteristics, such as robustness under secondary task loading, despite subsequent explicit learning. Participants acquired a complex motor skill (golf putting) over 400 trials. The environment was constrained early in learning to minimize performance error. It was predicted that in the absence of explicit instruction, reducing error would prevent hypothesis testing strategies and the concomitant accrual of declarative (explicit) knowledge, thereby reducing dependence on working memory resources. The effect of an additional cognitive task on putting performance was used to assess reliance on working memory. Putting performance of participants in the Implicit-Explicit condition was unaffected by the additional cognitive load, whereas the performance of Explicit participants deteriorated. The relationship between error correction and episodic verbal reports suggested that the explicit group were involved in more hypothesis testing behaviours than the Implicit-Explicit group early in learning. It was concluded that a constrained, uninstructed, environment early in learning, results in procedurally based motor output unencumbered by disadvantages associated with working memory control.     

Priming is independent of skill learning.

This study examined the relation between repetition priming and skill learning. Priming refers to facilitation in processing a specific item as a result of previous exposure to that item. Skill learning refers to general improvement in task performance as a function of practice. In Experiment 1 (N = 60), skill acquisition occurred in partial-word identification and inverted reading tasks but not in a word-fragment completion task. However, the amount of priming was the same in all three tasks. In Experiment 2 (N = 52), priming effects in partial-word identification did not vary as a function of practice with degraded words. In Experiment 3 (N = 40), skill learning was greater with high- than with low-frequency words, whereas priming was unaffected by word frequency. Experiment 4 (N = 20) ruled out the possibility that explicit retrieval was involved in the implicit memory tasks. These results suggest that priming can be independent of skill learning.     

Efficiency of Learning as a Function of Practice Schedule and Initial Ability

2 groups of 50 Ss practiced a pursuit rotor skill under different schedules of practice. A massed practice (MP) group (40 sec. work, 20 sec. rest) performed just as well as a distributed practice (DP) group (20 sec. work, 20 sec. rest) on the first day of practice. However, after 24 hr. of interpolated rest MP Ss demonstrated significantly greater amounts of learning. A further analysis of the 15 high initial ability and 15 low initial ability Ss from each of the two main groups resulted in no statistical differences among these subgroups in Day 1 performance that could be attributed to the practice schedules; however, a significant Ability Level × Practice Schedule interaction was obtained for Day 2 performance. It was caused by the low ability Ss under MP learning relatively more than the high ability Ss under MP when compared to the two DP groups. Thus learning was seen as being a function not only of schedule of practice but also of initial ability level.     

Goal orientation dispositions and performance trajectories: The roles of supplementary and complementary situational inducements

Integrating goal orientation theory with interactionist approaches, this experimental study (N = 104) tested the unique and interactive effects of individual differences in goal orientations and situational goal orientation inducements on performance trajectories during skill acquisition. Results indicated that learning goal orientation predicted performance trajectories more positively when coupled with one situational inducement that captures a complementary feature (a performance, as opposed to a learning, goal frame), and when jointed with a situational inducement that captures a supplementary feature (self-referenced vs. normative-based performance feedback). There was also a complementary-like interaction between the two situational inducements, such that a learning goal frame led to more positive performance trajectories when coupled with normative, as opposed to self-referent, feedback. Implications for the motivation and skill acquisition literatures are discussed.     

Selective sparing of memory functioning in a patient with amnesia following herpes encephalitis

A patient with amnesia subsequent to herpes encephalitis was assessed on a series of tasks which have been shown to result in normal or near normal performance by amnesic subjects. On a pursuit rotor learning task, our patient performed normally, and continued to show evidence of memory for the skill after a period of 30 days. On a perceptual learning task, which involved the identification of line drawings, he also displayed evidence of learning and long-term retention, but his performance remained below that of control subjects. In two priming experiments, which employed a "case-control" paradigm, performance on homonym-spelling and category item-generation tasks was preceded by exposure to a selected list of words. There was no evidence of differential facilitation in respect of those words used in the initial priming task. The findings point to some degree of selectivity of preserved learning capabilities in amnesia. It is hypothesized that this selectivity may be determined by several variables, including the type of task, the etiology and site of pathology, and the severity of amnesia.