Energetic and Cognitive Demands of Treading Water: Effects of Technique and Expertise.

Being able to tread water effectively can improve the likelihood of survival following accidental immersion. People tread water in various ways, ranging from rudimentary 'doggy-paddle' to more elaborate techniques like the eggbeater, but little is known about the energetic and cognitive requirements of treading water. We therefore aimed to measure the demands of treading water techniques for people of different experience levels. Three cohorts, comprising 21 adult water treading experts (water polo players), 15 intermediate swimmers and 16 inexperienced swimmers, treaded water for 3 min each using four different techniques while cognitive and energetic economy measures were taken. For inexperienced swimmers, the flutter kick and breaststroke patterns produced the lowest self-reported physical and task load (rating of perceived exertion, NASA task load index), while cognitive (probe reaction time), cardiac (heart rate) and metabolic (oxygen consumption) load did not differ between techniques. In contrast, for expert water treaders, both breaststroke and eggbeater patterns produced lower cognitive, cardiac and metabolic loads. For intermediate swimmers, breaststroke resulted in the lowest cardiac and metabolic loads, as well as self-reported task load. Probe reaction time was highest while performing the eggbeater technique, indicating that this technique was challenging to coordinate and cognitively demanding. While the energetic demands of antiphase kicking patterns (such as eggbeater in experts or flutter kick in beginners) may be similarly low, the symmetric coordination of upright breaststroke may explain why this pattern's cognitive economy was favourable for all groups. As the eggbeater can be challenging to perform for many people, an upright breaststroke technique is an adequate alternative to adopt in survival situations.

The Rowing-Specific Reinvestment Scale.

This research project aimed to develop and validate a rowing-specific reinvestment scale. In Study 1, a 24-item questionnaire was developed and the content validity was assessed using experts (N = 7) and pilot-tested in rowers (N = 24). Next, rowers (N = 282) completed the questionnaire with the remaining items, and exploratory factor analysis (EFA) was conducted. This further reduced the number of items and revealed two factors, rowing specific conscious motor processing (RS-CMP) and movement self-consciousness (RS-MSC). In Study 2, rowers (N = 270) completed the scale that was evaluated using confirmatory factor analysis (CFA). Moreover, the construct validity of the scale was investigated by asking them to complete measures of movement-specific reinvestment, perceived performance, self-consciousness, and state anxiety. Actual performance was also determined based on their race finishing position. Study 1 EFA resulted in a 2-factor model with six items assessing RS-CMP and six items assessing RS-MSC. Study 2 supported the factor structure of scale; CFA indicated an acceptable model fit with good internal consistency. Content validity was also supported, with evidence of concurrent, convergent, discriminant, and predictive validity. In conclusion, these studies provided good initial evidence for the validity and reliability of the RSRS.

The immediate influence of implicit motor learning strategies on spatiotemporal gait parameters in stroke patients: a randomized within-subjects design.

OBJECTIVES:: To investigate immediate changes in walking performance associated with three implicit motor learning strategies and to explore patient experiences of each strategy. DESIGN:: Participants were randomly allocated to one of three implicit motor learning strategies. Within-group comparisons of spatiotemporal parameters at baseline and post strategy were performed. SETTING:: Laboratory setting. SUBJECTS:: A total of 56 community-dwelling post-stroke individuals. INTERVENTIONS:: Implicit learning strategies were analogy instructions, environmental constraints and action observation. Different analogy instructions and environmental constraints were used to facilitate specific gait parameters. Within action observation, only videotaped gait was shown. MAIN MEASURES:: Spatiotemporal measures (speed, step length, step width, step height) were recorded using Vicon 3D motion analysis. Patient experiences were assessed by questionnaire. RESULTS:: At a group level, three of the four analogy instructions ( n = 19) led to small but significant changes in speed ( d = 0.088 m/s), step height (affected side d = 0.006 m) and step width ( d = -0.019 m), and one environmental constraint ( n = 17) led to significant changes in step width ( d = -0.040 m). At an individual level, results showed wide variation in the magnitude of changes. Within action observation ( n = 20), no significant changes were found. Overall, participants found it easy to use the different strategies and experienced some changes in their walking performance. CONCLUSION:: Analogy instructions and environmental constraints can lead to specific, immediate changes in the walking performance and were in general experienced as feasible by the participants. However, the response of an individual patient may vary quite considerably.

Falling for a Fake: The Role of Kinematic and Non-kinematic Information in Deception Detection.

Kinematic and non-kinematic visual information have been examined in the context of movement anticipation by athletes, although less so in deception detection. This study examined the role of kinematic and non-kinematic visual information in the anticipation of deceptive and non-deceptive badminton shots. Skilled ( n = 12) and less skilled ( n = 12) badminton players anticipated the direction of deceptive and non-deceptive shots presented via video footage displayed in normal (kinematic and non-kinematic information), low (kinematic information emphasized), and high (non-kinematic information emphasized) spatial frequency conditions. Each shot was occluded one frame before shuttle-racquet contact or at contact. In deceptive trials, skilled players showed decreased anticipation accuracy in the high spatial frequency condition ( p = .050) compared to normal and low spatial frequency conditions, which did not differ. The study suggests that an emphasis on kinematic information results in accurate anticipation in response to deceptive movements and that an emphasis on non-kinematic information results in less accurate anticipation by experts.

Investigating Changes in Real-time Conscious Postural Processing by Older Adults during Different Stance Positions Using Electroencephalography Coherence.

Background/Study Context: Adjustments of posture in response to balance challenges may lead to subsequent increases in conscious posture processing. If cognitive resources are stretched by conscious processing of postural responses fewer resources will be available to attend to environmental trip or fall hazards. The objective of the study was to explore brain activity related to conscious processing of posture as a function of movement specific reinvestment and fear of falling. Method: Forty-three older adults (M = 71.4, SD = 4.1) stood with a wide or narrow stance on a force-plate while neural coherence between verbal-analytical (T3) and motor planning (Fz) regions of the brain was assessed using electroencephalography. The propensity for movement specific reinvestment was assessed using the Chinese version Movement Specific Reinvestment Scale (MSRS-C) and fear of falling was assessed using the Chinese version Fall Efficacy Scale International (FES-I[CH]). Results: Scores from the MSRS-C were negatively correlated with changes in T3-Fz coherence that occurred when participants shifted from wide to narrow stance. Together, MSRS-C and FES-I(CH) uniquely predicted the percentage change in T3-Fz coherence between the two stance conditions. Conclusion: Presented with two postural tasks of different complexities, participants with a lower propensity for conscious control of their movements (movement specific reinvestment) exhibited larger changes in real-time brain activity (neural coherence) associated with conscious postural processing.

Investigating an errorless learning approach for developing dental operative technique skills: A pilot study.

INTRODUCTION: Explicit instruction (conscious knowledge/rules) is generally used for learning dental operative skills; however, recent work has demonstrated advantages of learning skills implicitly with minimal accrual of conscious knowledge and reduced attentional demands. Therefore, this study examined the effects of learning handpiece manipulation skills explicitly (errorful) and implicitly (errorless: limited error detection/correction) under conditions of increased attentional demands (ie multitasking and additional instructions). MATERIALS AND METHODS: Non-dental university students were randomly assigned to errorless (n = 11) or errorful (n = 8) groups. They used pencil lead instead of a bur, with errorless learners shading shapes from simple (small circle) to complex (cross), while errorful learners shaded the shapes in reverse. During testing, they completed simulated cavities in baseline, additional instructions and multitask conditions. Learning performance was calculated as per cent of the shape shaded successfully. Test performance was computed as error in cavity length/depth and was compared with dental students who had completed their operative technique course (n = 14). RESULTS: Errorless learners were more accurate than errorful learners especially when shading difficult shapes (P = 0.042). With additional instructions, errorless and errorful learners did not differ in cavity depth (P = 0.057) or length (P = 0.540). When multitasking, errorless learners prepared the cavity length (P = 0.048) but not depth (P = 0.920) more accurately than errorful learners. Overall, performance of errorless learners was comparable to dental students. CONCLUSIONS: These preliminary findings suggest handpiece skills can be acquired implicitly via errorless learning, and it is less attentionally demanding than errorful learning, as evident by maintenance of preparation performance when processing additional relevant instructions and multitasking.

Getting to the Root of Fine Motor Skill Performance in Dentistry: Brain Activity During Dental Tasks in a Virtual Reality Haptic Simulation.

BACKGROUND: There is little evidence considering the relationship between movement-specific reinvestment (a dimension of personality which refers to the propensity for individuals to consciously monitor and control their movements) and working memory during motor skill performance. Functional near-infrared spectroscopy (fNIRS) measuring oxyhemoglobin demands in the frontal cortex during performance of virtual reality (VR) psychomotor tasks can be used to examine this research gap. OBJECTIVE: The aim of this study was to determine the potential relationship between the propensity to reinvest and blood flow to the dorsolateral prefrontal cortices of the brain. A secondary aim was to determine the propensity to reinvest and performance during 2 dental tasks carried out using haptic VR simulators. METHODS: We used fNIRS to assess oxygen demands in 24 undergraduate dental students during 2 dental tasks (clinical, nonclinical) on a VR haptic simulator. We used the Movement-Specific Reinvestment Scale questionnaire to assess the students' propensity to reinvest. RESULTS: Students with a high propensity for movement-specific reinvestment displayed significantly greater oxyhemoglobin demands in an area associated with working memory during the nonclinical task (Spearman correlation, rs=.49, P=.03). CONCLUSIONS: This small-scale study suggests that neurophysiological differences are evident between high and low reinvesters during a dental VR task in terms of oxyhemoglobin demands in an area associated with working memory.

Examining links between anxiety, reinvestment and walking when talking by older adults during adaptive gait.

Falls by older adults often result in reduced quality of life and debilitating fear of further falls. Stopping walking when talking (SWWT) is a significant predictor of future falls by older adults and is thought to reflect age-related increases in attentional demands of walking. We examine whether SWWT is associated with use of explicit movement cues during locomotion, and evaluate if conscious control (i.e. movement specific reinvestment) is causally linked to fall-related anxiety during a complex walking task. We observed whether twenty-four older adults stopped walking when talking when asked a question during an adaptive gait task. After certain trials, participants completed a visuospatial recall task regarding walkway features, or answered questions about their movements during the walk. In a subsequent experimental condition, participants completed the walking task under conditions of raised postural threat. Compared to a control group, participants who SWWT reported higher scores for aspects of reinvestment relating to conscious motor processing but not movement self-consciousness. The higher scores for conscious motor processing were preserved when scores representing cognitive function were included as a covariate. There were no group differences in measures of general cognitive function, visuospatial working memory or balance confidence. However, the SWWT group reported higher scores on a test of external awareness when walking, indicating allocation of attention away from task-relevant environmental features. Under conditions of increased threat, participants self-reported significantly greater state anxiety and reinvestment and displayed more accurate responses about their movements during the task. SWWT is not associated solely with age-related cognitive decline or generic increases in age-related attentional demands of walking. SWWT may be caused by competition for phonological resources of working memory associated with consciously processing motor actions and appears to be causally linked with fall-related anxiety and increased vigilance.

Multitask training promotes automaticity of a fundamental laparoscopic skill without compromising the rate of skill learning.

BACKGROUND: A defining characteristic of expertise is automated performance of skills, which frees attentional capacity to better cope with some common intraoperative stressors. There is a paucity of research on how best to foster automated performance by surgical trainees. This study examined the use of a multitask training approach to promote automated, robust laparoscopic skills. METHODS: Eighty-one medical students completed training of a fundamental laparoscopic task in either a traditional single-task training condition or a novel multitask training condition. Following training, participants' laparoscopic performance was tested in a retention test, two stress transfer tests (distraction and time pressure) and a secondary task test, which was included to evaluate automaticity of performance. The laparoscopic task was also performed as part of a formal clinical examination (OSCE). RESULTS: The training groups did not differ in the number of trials required to reach task proficiency (p = .72), retention of skill (ps > .45), or performance in the clinical examination (p = .14); however, the groups did differ with respect to the secondary task (p = .016). The movement efficiency (number of hand movements) of single-task trainees, but not multitask trainees, was negatively affected during the secondary task test. The two stress transfer tests had no discernable impact on the performance of either training group. CONCLUSION: Multitask training was not detrimental to the rate of learning of a fundamental laparoscopic skill and added value by providing resilience in the face of a secondary task load, indicative of skill automaticity. Further work is needed to determine the extent of the clinical utility afforded by multitask training.

Surgeons' display reduced mental effort and workload while performing robotically assisted surgical tasks, when compared to conventional laparoscopy.

BACKGROUND: Research has demonstrated the benefits of robotic surgery for the patient; however, research examining the benefits of robotic technology for the surgeon is limited. This study aimed to adopt validated measures of workload, mental effort, and gaze control to assess the benefits of robotic surgery for the surgeon. We predicted that the performance of surgical training tasks on a surgical robot would require lower investments of workload and mental effort, and would be accompanied by superior gaze control and better performance, when compared to conventional laparoscopy. METHODS: Thirty-two surgeons performed two trials on a ball pick-and-drop task and a rope-threading task on both robotic and laparoscopic systems. Measures of workload (the surgery task load index), mental effort (subjective: rating scale for mental effort and objective: standard deviation of beat-to-beat intervals), gaze control (using a mobile eye movement recorder), and task performance (completion time and number of errors) were recorded. RESULTS: As expected, surgeons performed both tasks more quickly and accurately (with fewer errors) on the robotic system. Self-reported measures of workload and mental effort were significantly lower on the robotic system compared to the laparoscopic system. Similarly, an objective cardiovascular measure of mental effort revealed lower investment of mental effort when using the robotic platform relative to the laparoscopic platform. Gaze control distinguished the robotic from the laparoscopic systems, but not in the predicted fashion, with the robotic system associated with poorer (more novice like) gaze control. CONCLUSIONS: The findings highlight the benefits of robotic technology for surgical operators. Specifically, they suggest that tasks can be performed more proficiently, at a lower workload, and with the investment of less mental effort, this may allow surgeons greater cognitive resources for dealing with other demands such as communication, decision-making, or periods of increased complexity in the operating room.

Do people who consciously attend to their movements have more self-reported knee pain? An exploratory cross-sectional study.

OBJECTIVES: This study explored the relationship between propensity for conscious control of movement (assessed by the Movement-Specific Reinvestment Scale) and self-reported knee pain. DESIGN: Cross-sectional study. SETTING: General population. SUBJECTS: Adults aged 18 to 55 years of age. MEASURES: Participants completed the movement-specific reinvestment scale and a self-report questionnaire on knee pain at the same time on one occasion. RESULTS: Data was collected on 101 adults of whom 34 (33.7%) self-reported knee pain. Mean scores on the conscious motor processing subscale of the movement-specific reinvestment scale, but not the movement self-consciousness subscale, were significantly higher for participants who reported knee pain within the previous year compared with those who did not (mean difference 3.03; t-test 2.66, df = 97, P = 0.009; 95% confidence interval (CI) 0.77 to 5.30). The association between self-reported knee pain and propensity for conscious motor processing was still observed, even after controlling for movement self-consciousness subscale scores, age, gender and body mass index (adjusted odds ratio 1.16, 95% CI 1.04 to 1.30). CONCLUSIONS: Propensity for conscious control of movement may play a role in knee pain.

Examining Movement-Specific Reinvestment and Performance in Demanding Contexts.

Two experiments examined the roles of the dimensions of movement-specific reinvestment (movement self-consciousness and conscious motor processing) on performance under demanding conditions. In Experiment 1, novice golfers practiced a golf putting task and were tested under low- and high-anxiety conditions. Conscious motor processing was not associated with putting proficiency or movement variability; however, movement self-consciousness was positively associated with putting proficiency and appeared to be negatively associated with variability of impact velocity in low-anxiety conditions, but not in high-anxiety conditions. Increased anxiety and effort possibly left few attention resources for movement self-consciousness under high anxiety. In Experiment 2, participants performed a quiet standing task in single- and dual-task conditions. Movement self-consciousness was positively associated with performance when attention demands were low (single task) but not when attention demands were high (dual task). The findings provide insight into the differential influence of the two dimensions of movement-specific reinvestment under demanding conditions.

Scaling sporting equipment for children promotes implicit processes during performance.

This study investigated whether children who used scaled equipment compared to full size equipment during a motor task demonstrated reduced conscious involvement in performance. Children (9-11 years) performed a tennis hitting task in two attention conditions (single-task and dual-task) using two types of equipment (scaled and full size). A more skilled group and a less skilled group were formed using hitting performance scores. The more skilled group displayed greater working memory capacity than the less skilled group. For both groups, hitting performance and technique were better when scaled equipment was used. Hitting performance when using scaled equipment was not disrupted in either group by a cognitively demanding secondary task; however, performance was disrupted in the less skilled group when using full size equipment. We conclude that equipment scaling may reduce working memory engagement in motor performance and discuss the findings in the context of implicit motor learning theory.

Gaze training improves the retention and transfer of laparoscopic technical skills in novices.

BACKGROUND: Gaze training is an effective way of training basic laparoscopic skills, resulting in faster acquisition periods and more robust subsequent performance under pressure. The current study is a randomized control trial which examines whether the performance benefits of gaze training stand the test of time (delayed retention) and transfer to more complex skills. METHODS: Thirty-six medical students were trained to proficiency (50 trials) on a one-handed laparoscopic task (picking and dropping balls) in either a discovery learning (DL) or gaze training (GT) group. Both groups performed the one-handed task in baseline, retention and delayed retention (1 month) tests. They also performed baseline, retention and delayed retention tests of a two-handed task (grasping and cutting). Performance (completion time) and gaze control (target locking) were assessed throughout. RESULTS: For the one-handed task, the GT group displayed superior performance at retention (p < .001), underpinned by more expert-like gaze control (p < .05). The GT group also displayed superior performance in the one-handed task at delayed retention (p < .005), underpinned by more expert-like gaze control strategies (p < .001). Although the DL group's performance fell to 84% of performance at retention, the GT group maintained performance at 100% of retention. There were no differences between the groups for the two-handed task at retention (p = .140); however, at delayed retention, the GT group outperformed the DL group (p < .005) and displayed more expert-like gaze control (p < .001). CONCLUSIONS: Novices trained to adopt an expert-like gaze control strategy were able to attain higher levels of performance more quickly than novices who learned by discovery alone. Furthermore, these skills were more durable over time and were transferable to more complex skills. Gaze training is a beneficial intervention to aid the acquisition of the basic motor skills required for laparoscopy.

Investigating the Dutch Movement-Specific Reinvestment Scale in people with stroke.

OBJECTIVE: Reinvestment is a phenomenon in which conscious control of movements that are best controlled automatically disrupts performance. The propensity for reinvestment may therefore play an important role in the movement rehabilitation process. The Movement-Specific Reinvestment Scale measures an individual's propensity for reinvestment. The aim of this study was to translate the scale for use with Dutch participants with stroke and to assess its reliability. DESIGN: A test-retest design. SETTING: In community after discharge from rehabilitation centre. SUBJECTS: Forty-five people with stroke. MEASURES: Reliability of the translated scale was assessed using intraclass correlation coefficients (ICC) and Bland-Altman plot. RESULTS: The ICC was 0.85 (95% confidence interval (CI) 0.74-0.91). Limits of agreement ranged from -2.38 to 3.10. CONCLUSION: The Dutch Movement-Specific Reinvestment Scale appears to be a reliable tool with which to assess the propensity for movement-specific reinvestment by people with stroke.

Left, right, left, right, eyes to the front! Müller-Lyer bias in grasping is not a function of hand used, hand preferred or visual hemifield, but foveation does matter.

We investigated whether the control of movement of the left hand is more likely to involve the use of allocentric information than movements performed with the right hand. Previous studies (Gonzalez et al. in J Neurophys 95:3496-3501, 2006; De Grave et al. in Exp Br Res 193:421-427, 2009) have reported contradictory findings in this respect. In the present study, right-handed participants (N = 12) and left-handed participants (N = 12) made right- and left-handed grasps to foveated objects and peripheral, non-foveated objects that were located in the right or left visual hemifield and embedded within a Müller-Lyer illusion. They were also asked to judge the size of the object by matching their hand aperture to its length. Hand apertures did not show significant differences in illusory bias as a function of hand used, handedness or visual hemifield. However, the illusory effect was significantly larger for perception than for action, and for the non-foveated compared to foveated objects. No significant illusory biases were found for reach movement times. These findings are consistent with the two-visual system model that holds that the use of allocentric information is more prominent in perception than in movement control. We propose that the increased involvement of allocentric information in movements toward peripheral, non-foveated objects may be a consequence of more awkward, less automatized grasps of nonfoveated than foveated objects. The current study does not support the conjecture that the control of left-handed and right-handed grasps is predicated on different sources of information.

Distinct task-independent visual thresholds for egocentric and allocentric information pick up.

The dominant view of the ventral and dorsal visual systems is that they subserve perception and action. De Wit, Van der Kamp, and Masters (2011) suggested that a more fundamental distinction might exist between the nature of information exploited by the systems. The present study distinguished between these accounts by asking participants to perform delayed matching (perception), pointing (action) and perceptual judgment responses to masked Müller-Lyer stimuli of varying length. Matching and pointing responses of participants who could not perceptually judge stimulus length at brief durations remained sensitive to veridical stimulus length (egocentric information), but not the illusion (allocentric, context-dependent information), which was effective at long durations. Distinct thresholds for egocentric and allocentric information pick up were thus evident irrespective of whether perception (matching) or action (pointing) responses were required. It was concluded that the dorsal and ventral systems may be delineated fundamentally by fast egocentric- and slower allocentric information pick up, respectively.

Conscious monitoring and control (reinvestment) in surgical performance under pressure.

BACKGROUND: Research on intraoperative stressors has focused on external factors without considering individual differences in the ability to cope with stress. One individual difference that is implicated in adverse effects of stress on performance is "reinvestment," the propensity for conscious monitoring and control of movements. The aim of this study was to examine the impact of reinvestment on laparoscopic performance under time pressure. METHODS: Thirty-one medical students (surgery rotation) were divided into high- and low-reinvestment groups. Participants were first trained to proficiency on a peg transfer task and then tested on the same task in a control and time pressure condition. Outcome measures included generic performance and process measures. Stress levels were assessed using heart rate and the State Trait Anxiety Inventory (STAI). RESULTS: High and low reinvestors demonstrated increased anxiety levels from control to time pressure conditions as indicated by their STAI scores, although no differences in heart rate were found. Low reinvestors performed significantly faster when under time pressure, whereas high reinvestors showed no change in performance times. Low reinvestors tended to display greater performance efficiency (shorter path lengths, fewer hand movements) than high reinvestors. CONCLUSION: Trained medical students with a high individual propensity to consciously monitor and control their movements (high reinvestors) displayed less capability (than low reinvestors) to meet the demands imposed by time pressure during a laparoscopic task. The finding implies that the propensity for reinvestment may have a moderating effect on laparoscopic performance under time pressure.

The effects of fatigued working memory functions on hypothesis testing during acquisition of a motor skill.

Implicit motor learning paradigms aim to minimize verbal-analytical engagement in motor performance. Some paradigms do this by decreasing working memory activity during practice, which reduces explicit processes associated with the search for motor solutions (e.g., hypothesis testing). Here we designed a mentally demanding motor task to fatigue working memory prior to motor practice and then tested whether it reduced hypothesis testing. Fifty-nine participants were randomly assigned to complete the mentally demanding motor task (cognitive fatigue group) or to complete an undemanding motor task (nonfatigued control group). Feelings of fatigue, working memory functions, electroencephalography (EEG) Fz power, and vagal control were assessed pre- and posttask to quantify the effect of the mentally demanding motor task on cognitive fatigue. Thereafter, an adapted shuffleboard task was completed to determine the impact on hypothesis testing. Hypothesis testing was assessed by self-report, technique changes, and equipment-use solutions. Additionally, verbal-analytical engagement in motor performance was (indirectly) gauged with EEG T7-Fz connectivity and T7 power measures. Participants in the cognitive fatigue group reported more fatigue and displayed moderated working memory functions and Fz theta power. During practice of the shuffleboard task, participants also displayed more technique changes and higher verbal-analytical engagement in motor planning (EEG T7-Fz connectivity), compared with participants in the control group. The mentally demanding motor task suppressed working memory functions, but resulted in more, rather than less, hypothesis testing during shuffleboard practice. The implications are discussed in the context of implicit motor learning theory. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Attention and time constraints in perceptual-motor learning and performance: instruction, analogy, and skill level.

We sought to gain more insight into the effects of attention focus and time constraints on skill learning and performance in novices and experts by means of two complementary experiments using a table tennis paradigm. Experiment 1 showed that skill-focus conditions and slowed ball frequency disrupted the accuracy of experts, but dual-task conditions and speeded ball frequency did not. For novices, only speeded ball frequency disrupted accuracy. In Experiment 2, we extended these findings by instructing novices either explicitly or by analogy (implicit motor learning technique). Explicitly instructed novices were less accurate in skill-focused and dual-task conditions than in single-task conditions. Following analogy instruction novices were less accurate in the skill-focused condition, but maintained accuracy under dual-task conditions. Participants in both conditions retained accuracy when ball frequency was slowed, but lost accuracy when ball frequency was speeded, suggesting that not attention, but motor dexterity, was inadequate under high temporal constraints.