Task Proficiency Research Articles

Effects of Erythropoietin on Posttraumatic Place Learning in Fimbria-Fornix Transected Rats after a 30-Day Postoperative Pause

Human recombinant erythropoietin (EPO) has been shown to exert neuroprotective effects following both vascular and mechanical brain injury. Previously, we showed that behavioral symptoms associated with mechanical lesions of the hippocampus are nearly abolished due to EPO treatment. In these studies, the EPO administration took place simultaneously with the infliction of brain injury and the rehabilitation training started 6-7 days postoperatively. In the present study, we tested whether the therapeutic effect of EPO on the acquisition of an allocentric eight-arm radial maze spatial task also manifests itself if the rehabilitative training is postponed. Postoperatively, the animals were left without any specific stimulation for 30 days. The current results show an improved behavioral performance of the EPO-treated lesioned group relative to the saline-treated lesioned group, and confirm EPO's therapeutic effect even in case of postponed rehabilitation. However, compared to the control group, the EPO-treated lesioned group demonstrated an impaired task acquisition. All subjects eventually recovered functionally. Subsequently, the animals were given behavioral challenges during which the cue constellation in the room was changed. The challenges revealed that, although the EPO-treated lesion group had achieved the same level of task proficiency as the control group, the cognitive mechanisms mediating the task performance in the EPO-treated lesion group (as well as in the saline-treated lesion group) were dissimilar from those mediating the task in the control group. Both the EPO-treated and the saline-treated lesion group demonstrated an increased dependency on the original cue configuration.

Spectral and threshold effects on recognition of speech at higher-than-normal levels

To examine spectral and threshold effects for speech and noise at high levels, recognition of nonsense syllables was assessed for low-pass-filtered speech and speech-shaped maskers and high-pass-filtered speech and speech-shaped maskers at three speech levels, with signal-to-noise ratio held constant. Subjects were younger adults with normal hearing and older adults with normal hearing but significantly higher average quiet thresholds. A broadband masker was always present to minimize audibility differences between subject groups and across presentation levels. For subjects with lower thresholds, the declines in recognition of low-frequency syllables in low-frequency maskers were attributed to nonlinear growth of masking which reduced "effective" signal-to-noise ratio at high levels, whereas the decline for subjects with higher thresholds was not fully explained by nonlinear masking growth. For all subjects, masking growth did not entirely account for declines in recognition of high-frequency syllables in high-frequency maskers at high levels. Relative to younger subjects with normal hearing and lower quiet thresholds, older subjects with normal hearing and higher quiet thresholds had poorer consonant recognition in noise, especially for high-frequency speech in high-frequency maskers. Age-related effects on thresholds and task proficiency may be determining factors in the recognition of speech in noise at high levels.

Becoming team players: Team members' mastery of teamwork knowledge as a predictor of team task proficiency and observed teamwork effectiveness.

The authors explored the idea that teams consisting of members who, on average, demonstrate greater mastery of relevant teamwork knowledge will demonstrate greater task proficiency and observed teamwork effectiveness. In particular, the authors posited that team members' mastery of designated teamwork knowledge predicts better team task proficiency and higher observer ratings of effective teamwork, even while controlling for team task proficiency. The authors investigated these hypotheses by developing a structural model and testing it with field data from 92 teams (1,158 team members) in a United States Air Force officer development program focusing on a transportable set of teamwork competencies. The authors obtained proficiency scores on 3 different types of team tasks as well as ratings of effective teamwork from observers. The empirical model supported the authors' hypotheses.

Language cortex activation in normal children

Objective: To describe a protocol for use in young children and adolescents for determining language represen- tation. Methods: We performed 130 fMRI studies in 48 children and 17 adults. Verb generation (VG) and orthographic lexical retrieval (OLR) were used. The localization and lateralization of activation was rated visually. Regional voxel counts measured asymmetry and extent of activation. Results: Activation was predominantly left-lateralized (children 85%, adults 94%), and there was no difference in the localization of activation for either paradigm. Children’s typical sites of activation included mesial (96%), inferior (94%) and middle frontal (92%) gyri, the inferior (85%) and superior (65%) temporal cortex, and the cerebellum (67%). Less frequently activated sites were insular (50%) and posterior parietal (48%) cortices. Quantitative asymmetry index scores and visual inspection of laterality were concordant. Greater quantitative asymmetry for VG than OLR occurred in children. Laterality was not related to age, sex, task proficiency, or handedness. Frontal region voxel counts lower in children than adults and left sided counts correlated with task proficiency. Conclusions: Language fMRI can be performed in young children using resources available to clinical centers. The similarity in frequency of left language lateralization between children and adults suggests that language representation establishes early in development. The reduced amount of frontal region of interest activation in task-specific regions in children may reflect different levels of ability. However, the left-right distribution of activation does not appear to depend on task performance or age. These normative data provide a basis for decisions about language laterality in pediatric patients.

TEAMS' FEMALE REPRESENTATION AND PERCEIVED POTENCY AS INPUTS TO TEAM OUTCOMES IN A PREDOMINANTLY MALE FIELD SETTING

We developed a team‐level temporal model and tested it with data from 92 newly formed teams in a naturalistic military setting where females were a distinct minority in all teams. Contrary to what is posited by theory on customary perceptions of females' capabilities and gender‐role congruence, a higher female proportion within teams did not adversely influence teams' early perceived potency, later social cohesion, or observers' assessments of teamwork. Consistent with theory regarding gender and abilities, however, a higher female proportion within teams contributed to better team problem solving but led to slightly worse team results on physically demanding tasks. In addition, teams' early perceived potency contributed positively to early task proficiency and later social cohesion. Furthermore, teams' social cohesion contributed positively to externally observed teamwork while controlling for task proficiency. We discuss implications of these findings for theory and practice.

Task proficiency and L1 private speech

There is a growing volume of research on task-based language use; however, the nature of task proficiency has not yet been clearly defined. In order to gain new insights, this study examines the relationship between the process of communication in an L2 and a task outcome by analysing lexical density, as obtained from the pattern of a concordance of L1 private speech (i.e., self-directed speech). Lexical density is used to analyse the nature of interactive task performance. L1 private speech is a means of observing the way interlocutors make decisions on a moment-by-moment basis. Data were produced by pairs of Japanese college students during a map-completion task in English. The results clearly indicate that the pairs who achieved the best task results were, regardless of their English proficiency level, good at grasping the status of their task performance in both problematic and non-problematic situations. This requires reconceptualisation of L2 proficiency as an emergent property of dialogic processes.

Het Ongelijk van Netelenbos?

Within the context of school success of ethnic minority children in the Netherlands, it is currently debated what criteria should be applied by the Ministery of Education in assigning extra funds to children at risk. To this date, two criteria are used: level of parental education and parents' country of origin. As both criteria do no longer fully comply with the needs, it is proposed to test the children entering Kindergarten, with respect to their language proficiency in Dutch and/or their intelligence. This article reports the results of a longitudinal study on the language and school development of monolingual Dutch and bilingual ethnic minority children who were followed from entering Kindergarten at the age of 4, to the end of grade 6 in primaty school at the age of 12. During the first four years, Dutch language tasks ( ) were annually administered. Besides, children took an intelligence test (RAKIT) at the age of five. In grade 6, at the age of 12, a test battery of Dutch language proficiency, writing, reading, mathematics, science and information processing tasks were administered (Cito Eindtoets) to operationalise 'school success'. Finally, several background data were gathered, such as level of parental education and home language use. The results of regression analyses tentatively show that a language test administered in Kindergarten is the best predictor of school success (Multiple R= .432), that the intelligence test adjusts 4% to that, and that both home language use and parental education add another 2%. For the ethnic minority children alone, the Dutch language test (R2=.275) and home language use (adding 5%) are the only two predicting factors. However, if we look into the data as if we were teachers and had to decide whether or not to assign extra funds to a specific child on the basis of his/her test scores in Kindergarten, 29% of those assignments had been wrong: 14% wrongly not assigned ('false negatives'), and 15% wrongly assigned ('false positives'). For only 11% of the children the assignment of funds would have been predicted correctly. From this perspective, testing children in Kindergarten is not the most appropriate way to assign extra funds to children at risk.

Egocentric spatial orientation in a water maze by rats subjected to transection of the fimbria-fornix and/or ablation of the prefrontal cortex

The acquisition of a water maze based task requiring egocentric spatial orientation in the absence of distal cues was studied in four groups of rats: animals in which the fimbria-fornix had been transected, rats that received bilateral ablations of the anteromedial prefrontal cortex, animals in which both of these structures had been lesioned, and a sham-operated control group. Isolated lesions of both the anteromedial prefrontal cortex and the hippocampus were associated with a significantly impaired task acquisition. Both of these individually lesioned groups did, however, eventually demonstrate full functional recovery by reaching the task proficiency of the sham-operated control group. In contrast, the group in which both of these structures had been lesioned failed to demonstrate full functional recovery and was severely and long-lastingly impaired when compared to all other groups. Behavioural challenges in the form of a no-platform session and two reversals of platform position demonstrated that while the sham-operated control group and the group subjected to fimbria-fornix transections in isolation utilized rather pure egocentric orientation strategies, the two prefrontally lesioned groups (and especially the combined lesion group) employed a different set of solution strategies which at least partly relied on a “circling” method. Even in the behaviour of the prefrontally lesioned groups, however, indications of a certain level of cognitive representations of the platform positions were seen. It is concluded that both the prefrontal cortex and the hippocampus contribute to the mediation of egocentric spatial orientation. Furthermore, the hippocampus is a significant and potentially irreplaceable part of the neural substrate of functional recovery of the presently studied task after prefrontal lesions—while the prefrontal cortex may play a similar role with respect to hippocampal lesions.

Load- and practice-dependent increases in cerebro-cerebellar activation in verbal working memory: an fMRI study

Load-dependent and practice-related changes in neocortical and cerebellar structures involved in verbal working memory (VWM) were investigated using functional MRI (fMRI) and a two alternative forced choice Sternberg paradigm. Using working memory loads ranging from 2 to 6 letters, regions exhibiting linear and quadratic trends in load-dependent activations were identified. Behaviorally, reaction time measurements revealed significant linear increases with increasing memory load, and significant decreases with increased task practice. Brain activations indicated a preponderance of linear load-dependent responses in both superior (lobule VI/Crus I) and inferior (lobule VIIB/VIIIA) cerebellar hemispheres, as well as in areas of neocortex including left precentral (BA 6), inferior frontal (BA 47), parahippocampal (BA 35), inferior parietal (BA 40), cingulate (BA 32), and right inferior and middle frontal (BA 46/47) regions. Fewer voxels exhibited quadratic without linear trends with the most prominent of these activations located in left inferior parietal (BA 40), precuneus, and parahippocampal regions. Analysis of load × session interactions revealed that right inferior cerebellar and left inferior parietal activations increased with practice, as did the correlations between activation in each region with reaction time, suggesting that changes in this cerebro-cerebellar network underlie practice-related increases in efficiency of VWM performance. These results replicate and extend our previous findings of fMRI activation in the cerebellum during VWM, and demonstrate predominately linear increases in cerebro-cerebellar activation with increasing memory load as well as changes in network function with increased task proficiency.

Empirical Analysis of Drill Ratio Research

Providing students an appropriate level of challenge, called the instructional level, is an important component of effective instruction. Research regarding the optimal ratio of known to unknown items for drill tasks has been inconsistent. The author of the current article conducted an empirical meta-analysis of research on drill ratios by using the following groupings: < 50% known, 50% to 69% known, 70% to 85% known, and 90% known. Fifty-five effect size coefficients were computed, after eliminating outlying data, from 13 articles, with the 3 least challenging ratios resulting in strong mean effects. The most challenging (< 50% known) ratio resulted in a small to moderate effect. A mean effect size of .82 computed for various student outcomes compared to .43 for student preferences. Much stronger effects were also noted for tasks involving acquisition of new skills compared to proficiency tasks. Implications for research and practice are discussed.

Defining and evaluating context for wearable computing

Defining ‘context’ has proved to be a non-trivial problem for research in context-awareness. In this paper we address two questions: what features of activity are required to define context? and does the use of context-awareness measurably improve user performance? The first question was addressed by a study of everyday activities, using a Photo Diary method to arrive at a set of Context Identifiers. We feel that it is important to discover what features of activity are needed in order to describe context. Two user trials were carried out to address the second question. We conclude that the use of context improves user task proficiency.

Skilled-learning-induced potentiation in rat sensorimotor cortex: a transient form of behavioural long-term potentiation

The relation between the acquisition of a skilled motor task and synaptic plasticity in the sensorimotor cortex of the awake, freely behaving rat was examined. Skilled-motor training was previously found to induce a functional reorganization of the caudal forelimb area, and to induce an increase in synaptic efficacy, measured in vitro, on the side contralateral to the reaching forelimb. Here, we repeatedly measured neocortical evoked potential recordings in awake, freely behaving rats to examine whether skilled training would induce changes in polysynaptic efficacy on the side contralateral to the reaching forelimb. We found that the increase in task proficiency, but not the acquisition of task requirements or the maintenance of task proficiency, induced an increase in synaptic efficacy on the side contralateral to the reaching forelimb. We also tested the hypothesis that skilled learning induced potentiation shares similar mechanisms to long-term potentiation (LTP) and long-term depression by artificially manipulating polysynaptic efficacy in skilled rats with high- and low-frequency stimulation. We observed that, compared with the ipsilateral side, less potentiation but more depression could be induced on the side contralateral to the reaching forelimb. We conclude that a transient, network-based LTP-like mechanism operates during the learning of a skilled motor task.

Donepezil-induced improvement in delayed matching accuracy by young and old rhesus monkeys.

Donepezil (Aricept), a long-acting cholinesterase inhibitor, is widely used in the treatment of Alzheimer's disease to improve cognition and memory. Many drugs within the class of cognition-enhancing agents, both currently approved medications and those under development, have clinical indications narrowly relegated to Alzheimer's disease. The purpose of this study was to determine whether the efficacy attributed to donepezil in its ability to improve delayed matching accuracy by monkeys was independent of age. Male and female rhesus monkeys (n = 17) ranging from 9to 29 yr of age were administered donepezil (10, 25, 50, and 100 microg/kg, im) during 4 discrete test days. Donepezil treatment improved average task accuracy, but intersubject variability prohibited statistical significance. When animals were considered individually, the most effective dose of donepezil was associated with a highly significant increase in group task performance that was consistent with enhanced recall during testing. The variability associated with the dose-response analysis was attributable primarily to subject age, such that older monkeys required higher doses of donepezil. Yet at doses that were effective in all subjects, there was no relationship between age and the improvement in task accuracy. Likewise, there was no association between baseline task proficiency and improvement in task accuracy.

Gender Differentials in School Computer Technology Support Roles: An Analysis

Previous research on the attitudes of girls and women toward information technology indicates that they hold negative perceptions about their own computer use capabilities. These beliefs, combined with media influences predominantly portraying men in technology roles, often persuade women to choose non-technology related careers. This study looks at the presence and role of women in school technology support roles by surveying technology coordinators ( n = 129) from the upper plains region of the United States. Data on job responsibilities, professional training, training quality, and task proficiency are gathered. Analysis shows that women are disproportionately underrepresented in school technology support roles. Where equivalent training, experience, and job expectations exist, women are also under-compensated. A discussion follows suggesting that more women in the very visible school technology support role can be extremely influential in building beliefs among school-age girls that information technology careers are within their reach.

GROSS MECHANICAL EFFICIENCY OF HAND RIM WHEELCHAIR PROPULSION DURING SCI REHABILITATION

During rehabilitation of wheelchair-dependent individuals with a spinal cord injury (SCI), task proficiency is expected to improve as a consequence of learning and training. During submaximal wheelchair propulsion, gross mechanical efficiency (ME) is viewed as an adequate indicator of overall task proficiency. Currently, no data exist in this respect. PURPOSE To describe and analyze changes in ME during SCI rehabilitation. METHODS In the context of a Dutch multi-center prospective cohort study, 23 subjects with SCI (3 subjects with tetraplegia, 5 females) performed three subsequent submaximal wheelchair exercise tests on a motor driven treadmill: at the start of active rehabilitation (t1), 3 months later (t2) and at the end of clinical rehabilitation (t3). In each test, ME was evaluated for the final minute of each of two 3-min stages of submaximal wheelchair exercise in a standardized hand rim wheelchair on a motor driven treadmill. Changes over time were evaluated with an ANOVA for repeated measures (main factors (levels): time((t1,2,3), (3)); exercise stage (2); level of significance: p < 0.05). RESULTS Mean power output was 9.2±4.3W and 13.5±5.2W for the subsequent two stages at t1, and showed a small but significant increase over time (10.0±4.2W and 14.8±4.9W for the respective two stages at t3). Oxygen uptake showed a slight non-significant downward trend over time. Mean ME significantly increased for the first stage from 5±2% at t1 to 5.6±2.1% at t3 and from 7.1±2.5% at t1 to 7.8±2.6% at t3 for the second exercise stage (p < 0.01). Mean heart rate and ventilation significantly dropped over time at both levels of power output (p < 0.01). CONCLUSIONS Results show a steady increase in wheeling proficiency over time, indicating effects of learning and training during the course of rehabilitation. At a later stage of this multi-center study the role of lesion level, completeness of the lesion, age and gender on ME will be evaluated. Supported by ZON-MW Rehabilitation grant 1435.0003

Estimating the difficulty of oral proficiency tasks: what does the test-taker have to offer?

This study investigates the impact of performance conditions on perceptions of task difficulty in a test of spoken language, in light of the cognitive complexity framework proposed by Skehan (1998). Candidates performed a series of narrative tasks whose characteristics, and the conditions under which they were performed, were manipulated, and the impact of these on task performance was analysed. Test-takers recorded their perceptions of the relative difficulty of each task and their attitudes to them. Results offered little support for Skehan’s framework in the context of oral proficiency assessment, and also raise doubts about post hoc estimates of task difficulty by test-takers.

Model for Predicting Performance of Architects and Engineers

Certain attributes of an architect or engineer (AE) may be used to predict his performance. These attributes may be categorized as “hard” or “soft” attributes. Hard attributes include an AE’s cognitive ability, job knowledge, task proficiency, and job experience. Soft attributes include an AE’s conscientiousness, initiative, social skills, controllability, and commitment. The purpose of this study is to identify those attributes that affect an AE’s performance, and to construct a model to predict his performance in design build (DB) projects. Twenty-five attributes were generated using the hierarchy tree. The importance of these attributes was tested with designer/builders who select and hire AEs, using a standard questionnaire. A statistical test showed that 24 of these attributes are significantly important. Thirty AEs were evaluated by experienced designer/builders (experts) who have worked with them in completed DB projects. Besides giving a global performance score of the AE (dependent variable), each expert also evaluated the AE on the degree to which they exhibited the important attributes (independent variables). Based on these ratings, an optimum multiple regression performance prediction model was obtained. To validate the model, another group of experts used the optimum model to evaluate 18 other AEs. The resulting performance score as calculated by the model was compared to the global performance scores awarded by the designer/builders. This validation process showed the model to be robust. The results of the study reveal that an AE’s performance can be predicted by using just three attributes: AE’s problem-solving ability and project approach. AE’s speed in producing design drawings, and the AE’s level of enthusiasm in tackling a difficult assignment.

Sex, Education, Age, and Cautiousness: Implications for Counselors

A cross-sectional study of educated men and women showed that cautiousness, as measured by perceived problem-solving ability, does not increase with age. Sex differences were nonsignificant. The results are discussed in terms of R. Schultz and J. Heckhausen's (1996) Life Span Model of Successful Aging. ********** Problem solving is an important skill at any age for men, women, and children. Data indicated that problem-solving skills decreased with age, as reflected in individuals' psychomotor skills (Welford, 1977). Psychomotor ability is sometimes interpreted as or as a slowing of reaction time (Welford, 1977). Two important measures in the field of psychomotor ability are tracking proficiency, measured as time on target, and psychomotor reminiscence. Reminiscence is a gain in task proficiency following a rest period. Wright and Payne (1985) found large significant differences in psychomotor tracking proficiency when a sample of elderly adults was compared with a sample of college students on mirror tracing and rotary pursuit tracking equipment. Wright and Payne also found that the sex differences in psychomotor reminiscence observed in young adults by some researchers (e.g., Buxton & Grant, 1939; Coppage & Payne, 1981; Hsu & Payne, 1979; Huang & Payne, 1975; McLean & Payne, 1982) was not observed in their own sample of elderly adults. The findings indicated that elderly adults seemed to be more cautious in their approach to eye-hand coordination tasks. This finding might have been due to general psychomotor slowing with advanced age (Wright & Payne, 1985). A larger cross-sectional sample by Thumin (1962) also pointed to a trend of general psychomotor slowing with age. Thumin used a rotary pursuit apparatus to test individuals between 11 and 72 years old. He also found that reminiscence decreased in advanced adulthood. Personality traits have also been found to be a factor in an individual's cautiousness. In a review of the literature on cautiousness, Woodruff-Pak (1988) pointed out that a cautiousness strategy can be viewed as a natural outcome of the slowing of response speed and the decline of sensory and motor capacities (p. 350); thus, the term can be used to describe actions and can be used as behavioral descriptors. Because so much of the research on used a cross-sectional design, Woodruff-Pak described as a cohort effect rather than as an inevitable change with age. Mirowsky (1995), for example, studied of using an eight-item inventory with two random samples of adults, ages 18-90 years. He found significant steep declines after the 40s. He also found that adjustment for education accounted for more than 25% of the association observed between sense of control and age. As a personality trait, may be observed as desurgency, the term used on the Sixteen Personality Factor Questionnaire (16PF; Cattell, Eber, & Tatsuoka, 1970). At the other end of the continuum is surgency, which indicates a more carefree individual. Fozard (1972) studied 970 men (ages 28-83 years), using the 16PF, and found that the correlation between factor F (surgency) and age was -.23, which indicated greater (p A currently popular research tool, which may be partially interpreted in terms of cautiousness, is the Problem Solving Inventory (PSI; Heppner, 1988a). The PSI consists of 35 statements that are ranked on a 6-point rating scale and yields three subscores and a total score. …

Foreign language learning, hyperlexia, and early word recognition

Children with hyperlexia read words spontaneously before the age of five, have impaired comprehension on both listening and reading tasks, and have word recognition skill above expectations based on cognitive and linguistic abilities. One student with hyperlexia and another student with higher word recognition than comprehension skills who started to read words at a very early age were followed over several years from the primary grades through high school when both were completing a second-year Spanish course. The purpose of the present study was to examine the foreign language (FL) word recognition, spelling, reading comprehension, writing, speaking, and listening skills of the two students and another high school student without hyperlexia. Results showed that the student without hyperlexia achieved higher scores than the hyperlexic student and the student with above average word recognition skills on most FL proficiency measures. The student with hyperlexia and the student with above average word recognition skills achieved higher scores on the Spanish proficiency tasks that required the exclusive use of phonological (pronunciation) and phonological/orthographic (word recognition, spelling) skills than on Spanish proficiency tasks that required the use of listening comprehension and speaking and writing skills. The findings provide support for the notion that word recognition and spelling in a FL may be modular processes and exist independently of general cognitive and linguistic skills. Results also suggest that students may have stronger FL learning skills in one language component than in other components of language, and that there may be a weak relationship between FL word recognition and oral proficiency in the FL.

A NOVEL GOAL-ORIENTED APPROACH FOR TRAINING OLDER ADULT COMPUTER NOVICES: BEYOND THE EFFECTS OF INDIVIDUAL-DIFFERENCE FACTORS

The present research evaluated a goal-oriented training approach in comparison to a more standard training approach (i.e., verbal persuasion). The goal-oriented approach combined participatory goal setting with performance feedback to enhance training with older adults. One hundred and six computer novices, ranging in age from 50-89 years, were randomly assigned to one of the two training conditions and individually participated in two consecutive days of computer spreadsheet training. As hypothesized, Goal-oriented trainees generally achieved significantly greater mean changes in both computer attitudinal/efficacy and computer task proficiency measures (e.g., task completion time). Verbal Persuasion trainees also exhibited significant changes in both types of training outcomes but to a lesser extent than Goal-oriented trainees. Controlling for scores on intellectual ability (crystallized, fluid) and the ''big five'' personality dimensions through analysis of covariance did not significantly change study results.