Attending to the execution of a complex sensorimotor skill: expertise differences, choking, and slumps

A simulated baseball batting task was used to compare the relative effects of attending to extraneous information (tone frequency) and attending to skill execution (direction of bat movement) on performance and swing kinematics and to evaluate how these effects differ as a function of expertise. The extraneous dual task degraded batting performance in novices but had no significant effect on experts. The skill-focused dual task increased batting errors and movement variability for experts but had no significant effect on novices. For expert batters, accuracy in the skill-focused dual task was inversely related to the current level of performance. Expert batters were significantly more accurate in the skill-focused dual task when placed under pressure. These findings indicate that the attentional focus varies substantially across and within performers with different levels of expertise.     

Putting in the mind versus putting on the green: expertise, performance time, and the linking of imagery and action

Does manipulating the time available to image executing a sensorimotor skill impact subsequent skill execution outcomes in a similar manner as manipulating execution time itself? Novice and skilled golfers performed a series of imaged golf putts followed by a series of actual golf putts under instructions that emphasized either speeded or nonspeeded imaging/putting execution. Novices putted less accurately (i.e., higher putting error score) following either putting or imagery instructions in which speed was stressed. Skilled golfers showed the opposite pattern. Although more time available to execute a skill enhances novice performance, this extra time harms the proceduralized skill of experts. Manipulating either actual execution time or imagined execution time produces this differential impact on novice and skilled performance outcomes. These results are discussed in terms of the functional equivalence between imagery and action and expertise differences in the attentional control structures governing complex sensorimotor skill execution.     

Influence of Domain Knowledge on Monitoring Performance Across the Life Span

Two studies were conducted to investigate effects of domain knowledge on metacognitive monitoring across the life span in materials of different complexity. Participants from 4 age groups (3rd-grade children, adolescents, younger and older adults) were compared using an expert–novice paradigm. In Study 1, soccer experts’ and novices’ ease-of-learning judgments (EOLs), judgments of learning (JOLs), and confidence judgments (CJs) were contrasted when memorizing soccer-related word pairs. In Study 2, monitoring judgments (i.e., a rating of global comprehension, JOLs, and CJs) were collected in regards to a soccer-related narrative. The results of both approaches showed that experts’ better memory performance obtained in both studies was not always accompanied by advantages in monitoring performance. In Study 1, experts of all ages outperformed novices in monitoring accuracy. In Study 2, no benefits of expertise on monitoring were found; in children, novices even surpassed experts in monitoring quality. In both studies, the most consistent influence of previous domain knowledge on monitoring performance concerned more optimistic judgments of experts compared with novices, regardless of stimuli and recall format. In sum, our results document a twofold effect of expertise on monitoring. Although domain-specific knowledge enhances monitoring performance in some situations, more optimistic estimates, presumably due to the application of a familiarity heuristic, typically reduce experts’ monitoring accuracy.     

Expertise Shapes Multimodal Imagery for Wine

Although taste and smell seem hard to imagine, some people nevertheless report vivid imagery in these sensory modalities. We investigate whether experts are better able to imagine smells and tastes because they have learned the ability, or whether they are better imaginers in the first place, and so become experts. To test this, we first compared a group of wine experts to yoked novices using a battery of questionnaires. We show for the first time that experts report greater vividness of wine imagery, with no difference in vividness across sensory modalities. In contrast, novices had more vivid color imagery than taste or odor imagery for wines. Experts and novices did not differ on other vividness of imagery measures, suggesting a domain-specific effect of expertise. Critically, in a second study, we followed a group of students commencing a wine course and a group of matched control participants. Students and controls did not differ before the course, but after the wine course students reported more vivid wine imagery. We provide evidence that expertise improves imagery, exemplifying the extent of plasticity of cognition underlying the chemical senses.     

The influence of degree of expertise and objective task complexity on perceived task complexity and performance

Research on expertise has shown that nonexperts may sometimes outperform experts. Some researchers have suggested that superior performance by experts depends on the match between the experts' cognition and the demands of the task. The authors explored this issue using a quasi-experiment set in an organization. They examined how 3 sets of similar tasks that differ in their type of complexity can lead to differences in task perceptions and performance among experts, intermediates, and novices. The results suggest that experts and novices pay attention to different aspects of a task and that this affects both their perceptions of task complexity (i.e., task analyzability and variability) and their performance on the task.     

Influence of Expertise on the Intentional Transfer of Motor Skill

Intentional transfer of expert knowledge is an important issue in cognitive science and motor skills. How subjects deliberately transfer expertise in karate when learning a closely related motor skill (tai chi) was examined in this study. Subjects (N = 20) learned a videotaped sequence of self-defense movements, evaluated their learning, and then performed the sequence. Self-regulation of learning is believed to be central to effective transfer. The measures of self-regulation were accuracy of self-evaluation, video use, and approach to learning. Results showed that unlike novices, experts used self-regulation, learning strategies, and the video player in more complex ways in self-regulation. Experts, as compared with novices, demonstrated their greater knowledge through the higher quality of their performance and their better comprehension of movement meaning; but both groups recalled an equal number of moments, suggesting that both experts and novices transferred general knowledge about learning.     

On the origin of intermediate effects in clinical case recall

In two experiments, the effects of level of medical expertise and study time on free recall of a clinical case were assessed. In Experiment 1, a nonmonotonic relationship between level of expertise and recall was found: Subjects of intermediate levels of expertise remembered more information from the case than both experts and novices. This “intermediate effect” disappeared, however,when study time was restricted. Analysis of post hoc acquired protocols of pathophysiological knowledge active during case processing suggested that this phenomenon could be attributed to the nature of the pathophysiological knowledge mobilized to comprehend the case. In Experiment 2, this assumption was directly tested by priming relevant pathophysiological knowledge for either a short or a longer period, before enabling subjects to study the case briefly. Free-recall data confirmed and extended the results of Experiment 1. Again, an intermediate effect was found; this time, however, it was generated experimentally. The findings were interpreted in terms of qualitative differences in the nature of the knowledge structures underlying performance between novices, advanced students, and medical experts: Experts use knowledge in an encapsulated mode while comprehending a case, whereas students use elaborated knowledge.     

Is imagery better than reality? Performance in imagined dart throwing

We investigated whether deviations from optimal performance are predicted in motor imagery. In Experiment 1, novices and experts imagined and executed dart throws. In imagination, they reported the final position of the dart. Experts performed better than novices in execution and imagination. Distance to the target and bias were smaller in imagination than in execution. In Experiment 2, we dissociated the roles of feedback from proximal and distal action elements for predictions. Three groups of novices estimated the dart’s final position in imagination, in execution without visual feedback, or in execution with delayed visual feedback. Estimates did not differ significantly between groups, indicating that (the lack of) feedback did not influence predictions. Deviations from optimal performance were lower in estimated than in actual performance. In conclusion, although predictive mechanisms may be similar in imagination and execution, the full extent of deviation from optimal performance is not predicted.     

Relation of knowledge and performance in boys' tennis: age and expertise

This research examined boys' development of knowledge structure and sport performance in tennis. To assess decision-making and performance, expert and novice tennis players (10-11 and 12-13 years old) were compared on tennis performance (control, decision, and execution), tennis knowledge, serve skill, and groundstroke skill. Experts regardless of age performed better than novices on tennis skill and knowledge; experts' decisions and actions were better during tennis game performance. Declarative knowledge was related to the development of procedural knowledge; serve and groundstroke skill were related to the motor execution components of performance. Interviews during and after game play were used to examine knowledge and decision-making. Experts, as compared to novices, focused on higher level concepts, had more connections between concepts, and had more condition and alternative action concepts that were important to the game's goal structure. Experts' greater decision-making ability during game play was related to their knowledge structure.     

运动技能水平与躯体感觉输入对运动表象的影响

运动表象质量与运动技能水平有关,运动表象质量随着运动技能水平的提高而上升。器械使用可使人脑产生可塑性改变,使用者会将器械纳入身体图式。然而,两者影响运动表象的神经心理机制还不清楚。本研究采用功能性磁共振成像探析篮球运动员与新手在不同持球条件下表象投篮时脑功能活动的差异。结果表明运动员表象质量较好,镜像神经系统激活高于新手;持球条件下运动员表象质量显著高于不持球条件下,镜像神经系统激活程度显著低于不持球条件下。研究说明持器械可以显著提高运动员的表象质量,器械使用带来镜像神经系统的可塑性变化。     

Analogical transfer and expertise in legal reasoning

Analogical transfer and its relation to expertise is examined in a legal context. Three experiments were conducted comparing the performance of novices (introductory tax students) and of experts (experienced tax practitioners from multinational public accounting firms) on tasks involving the application of tax laws. In Experiment 1 subjects completed a target problem after reading a decided case that was either analogous or not analogous to a target problem. A limited amount of transfer was observed, with no differential rate of transfer across experience levels. In Experiments 2 and 3 attempts were made to facilitate transfer of knowledge by inducing transfer-appropriate processing of the source analog and by providing multiple source analogs. The results of both experiments indicate an interaction between treatment and expertise. Unexpectedly, the facilitating treatments reduced the transfer of knowledge for experts while increasing the transfer for novices. Subsequent analysis of the responses of the expert subjects indicates that for the more experienced expert subjects a highly proceduralized rule interfered with the knowledge transfer when that rule was made salient by the facilitating treatments. The less experienced expert subjects behaved in a manner consistent with the hypotheses. This poor performance of the more experienced experts results from the inflexibility in expert problem solving due to the proceduralization of information processing. Frensch and Sternberg (1989) demonstrate that this type of inflexibility is one of the costs of expertise and results from the development of a large and highly complex knowledge base containing numerous well developed strategies.     

Expertise increases the functional overlap between face and object perception

Recent studies indicate that expertise with objects can interfere with face processing. Although competition occurs between faces and objects of expertise, it remains unclear whether this reflects an expertise-specific bottleneck or the fact that objects of expertise grab attention and thereby consume more central resources. We investigated the perceptual costs of expertise by measuring visual thresholds for identifying targets embedded within RSVP sequences presented at varying temporal rates. Car experts and novices searched for face targets among face and car distractors, or watch targets among watch and car distractors. Remarkably, car experts were slower than novices at identifying faces among task-irrelevant cars, yet faster than novices at identifying watches among cars. This suggests that car expertise leads to greater functional overlap between cars and faces while reducing the functional overlap between cars and objects, a result incompatible with the notion of an encapsulated module for exclusive processing of faces.     

The influence of expertise and of physical complexity on visual short-term memory consolidation

We investigated whether the expertise of a perceiver and the physical complexity of a stimulus influence consolidation of visual short-term memory (VSTM) in a S1-S2 (Stimulus 1-Stimulus 2) change detection task. Consolidation is assumed to make transient perceptual representations in VSTM more durable, and it is investigated by postexposure of a mask shortly after offset of the perceived stimulus (S1; 17 to 483?ms). We presented colours, Chinese characters, pseudocharacters, and novel symbols to novices (Germans) or experts of Chinese language (Chinese readers). Physical complexity was manipulated by the number of strokes. Unfamiliar material was remembered worse than familiar material (Experiments 1, 2, and 3). For novices the absolute VSTM performance was better for physically simple than for complex material, whereas for experts the complexity did not matter-Chinese readers memorized Chinese characters (Experiment 3). Articulatory suppression did not change these effects (Experiment 2). We always observed a strong effect of SOA, but this effect was influenced neither by physical complexity nor by expertise; only the length of the interstimulus interval between S1 and the mask was relevant. This was observed even with short stimulus onset asynchrony (SOA) of 100?ms (Experiment 2) and in comparing colours and characters (Experiment 5). However, masks impaired memory if they were presented at the locations of the to-be-memorized items, but not beside them-that is, interference was location-based (Experiment 6). We explain the effect of SOA by the assumption that it takes time to stop encoding of information presented at item locations with the offset of S1. The increasing resistance against interference by irrelevant material appears as consolidation of S1.     

The world of competitive Scrabble: Novice and expert differences in visuopatial and verbal abilities

Competitive Scrabble players spend a mean of 4.5 hr a week memorizing words from the official Scrabble dictionary. When asked if they learn word meanings when studying word lists, only 6.4% replied "always," with the rest split between "sometimes" and "rarely or never." Number of years of play correlated positively with expertise ratings, suggesting that expertise develops with practice. To determine the effect of hours of practice (M = 1,904), the authors compared experts with high-achieving college students on a battery of cognitive tests. Despite reporting that they usually memorize word lists without learning meanings, experts defined more words correctly. Reaction times on a lexical decision task (controlling for age) correlated with expertise ratings, suggesting that experts develop faster access to word identification. Experts' superiority on visuospatial processing was found for reaction time on 1 of 3 visuospatial tests. In a study of memory for altered Scrabble boards, experts outperformed novices, with differences between high and low expertise on memory for boards with structure-deforming transformations. Expert Scrabble players showed superior performance on selected verbal and visuospatial tasks that correspond to abilities that are implicated in competitive play.     

Categorization and representation of physics problems by experts and novices

The representation of physics problems in relation to the organization of physics knowledge is investigated in experts and novices. Four experiments examine (a) the existence of problem categories as a basis for representation; (b) differences in the categories used by experts and novices; (c) differences in the knowledge associated with the categories; and (d) features in the problems that contribute to problem categorization and representation. Results from sorting tasks and protocols reveal that experts and novices begin their problem representations with specifiably different problem categories, and completion of the representations depends on the knowledge associated with the categories. For, the experts initially abstract physics principles to approach and solve a problem representation, whereas novices base their representation and approaches on the problem's literal features.     

Representing others' actions: the role of expertise in the aging mind

A large body of evidence suggests that action execution and action observation share a common representational domain. To date, little is known about age-related changes in these action representations that are assumed to support various abilities such as the prediction of observed actions. The purpose of the present study was to investigate (a) how age affects the ability to predict the time course of observed actions; and (b) whether and to what extent sensorimotor expertise attenuates age-related declines in prediction performance. In a first experiment, older adults predicted the time course of familiar everyday actions less precisely than younger adults. In a second experiment, younger and older figure skating experts as well as age-matched novices were asked to predict the time course of figure skating elements and simple movement exercises. Both young age and sensorimotor expertise had a positive influence on prediction performance of figure skating elements. The expertise-related benefit did not show a transfer to movement exercises. Together, the results suggest a specific decline of action representations in the aging mind. However, extensive sensorimotor experience seems to enable experts to represent actions from their domain of expertise more precisely even in older age.     

Response selection and execution skills of professionals and novices during singles tennis competition.

This study extended research on sport expertise concerning the development of cognitive and motor skills in singles tennis (McPherson, 1999). 12 adult male professional and novice tennis players were videotaped during singles competition. Opponents for matches were randomly selected within each group of participants. Two tennis experts utilized an observational scale to judge players' performance generated during competition for serves and shots following the serve, e.g.. return of serves, lobs. Each player was scored on three performance components: quality of movement to or control of the ball for serves or shots attempted (control skills), appropriateness of serve or shot selections in the context of game situations (response selection skills), and quality of serves or shots produced (response execution skills). Relative frequency scores for the highest category of each performance component were derived according to the number of opportunities to respond. Serve performance indicated both groups were able to control their serves: however, professionals made more tactical selections and forceful executions. Shot performance indicated professionals made more successful movement to and control of shots, tactical shot selections, and forcing shot executions than novices. Overall, players' tactical response selections were greater than their forceful response executions. Thus, assessing players' decisions during competition may provide vital information concerning tactical skill development. Further, professional players exhibited higher and more consistent tactical behavior than elite collegiate players examined in 1999 by McPherson. Findings were attributed to tactical knowledge and motor skill development resulting from competition and practice experiences.