Tasks Of Different Levels Research Articles

Non-linear EEG synchronization during observation and execution of simple and complex sequential finger movements

The main aim of this study was to examine the temporal aspects of neuronal changes during the observation and execution of simple and complex tasks to gain a greater understanding of the mirror neuron system's involvement in complex motor tasks. Eleven right-handed subjects observed simple and complex finger movement sequences. Electroencephalograms were recorded from 19 electrodes. Activity was considered in four frequency bands (8-10, 10-13, 13-20, and 20-30 Hz) using a new measure, synchronization likelihood. The results show that motor tasks of different levels of complexity did not have a significant influence on cortical synchronization. The results also provide additional indirect evidence for mirror neuron activity associated with intransitive tasks. Data are discussed in the light of recent findings from the cognitive and behavioral neuroscience literature.

The Impact of Simulation Training on Call Center Agent Performance: A Field-Based Investigation

The most prevalent form of training call center agents is via classroom instruction coupled with role-plays. Role-play training has a theoretical base in behavior modeling that entails observation, practice, and feedback. Emerging simulation-based technologies offer enhancements to behavior modeling that are absent in role-play training. This study evaluates the effectiveness of simulation-based training (henceforth, simulation training) as a behavior modeling technique vis-à-vis role-play training in a real-world call center environment across tasks of different levels of complexity. We collaborate with call centers at two Fortune 50 firms and examine on-job performance metrics to evaluate the effectiveness of simulation training. The performance measures of interest are call accuracy and call duration because these are two important factors that influence customer satisfaction and productivity in call center operations. After controlling for factors such as trainee's learning and technology orientation, age, education, and call center experience, results show that simulation training outperforms role-playing-based training in terms of both accuracy and speed of processing customer calls. Further, the relative superiority of simulation training improves at higher levels of task complexity.

Dynamic Optimisation of Chemical Engineering Processes Using the Bees Algorithm

An improved version of the Bees Algorithm is proposed for solving dynamic optimisation problems. This new formulation of the Bees Algorithm includes new search operators, and a new selection procedure that enhances the survival probability of newly formed individuals. The proposed algorithm is tested on six benchmark dynamic optimisation problems. The benchmark problems include minimisation and maximisation tasks of different levels of complexity. For all the problems, the Bees Algorithm finds very satisfactory optima. The very small standard deviation of the results proves the high reliability of the proposed technique. Experimental tests show that the Bees Algorithm outperforms the state-of-the-art Ant Colony Optimisation algorithm. The Bees Algorithm improves also the best results published in the literature for the six benchmark problems.

Enlentecimiento cognitivo en sujetos seropositivos asintomáticos al virus de inmunodeficiencia humana tipo 1

Reaction time (RT) is thought to be the most suitable measure to detect cognitive deficits in neurologically asymptomatic human immunodeficiency virus type I (HIV-1) infected individual since cognitive slowing is the earliest signal of cognitive-motor disorder related to HIV-1 infection. There is evidence suggesting that the greater the degree of central processing demands required by a task, the more likely that it will be sensitive to the effect of HIV-1 infection. Such statement suggests that the RT deficits exhibited by HIV-1 infected individuals at initial stages could be caused by the slowing of central information processing mechanisms. To assess the relationships between demands of central information processing and RT in HIV-1 seropositive individuals. 50 neurologically asymptomatic HIV-1 individuals were compared with 34 seronegative controls on four discriminative RT tasks of different levels of central processing demands except by the motor response requirements. Seropositive group was slower in RT and performed worse on the higher demanding task. On the lesser demanding tasks no differences in RT nor in accuracy were observed. For the task demanding sensory coding efforts seropositive individual were slower but achieved the same level of accuracy. Even when these results point to that RT slowing in HIV-1 asymptomatic individuals emerged with the increase in cognitive demands, the fact that RT slowing without accuracy declining can also appear in some tasks demanding sensory processing, preclude ruling out a peripheral deficit as the locus of the RT slowing in these subjects.

Which factors affect hand selection in children’s grasping in hemispace? Combined effects of task demand and motor dominance

Sixty-five right- and left-handed preschool and school children were tested on three reach-to-grasp tasks of different levels of complexity, performed in three space locations. Our goal was to evaluate how the effect of attentional information related to object location interacts with task complexity and degree of handedness on children’s hand selection. Results revealed a shift to the non-preferred hand in the contralateral hemispace, which was more or less pronounced according to the level of task complexity. The subject’s degree of handedness also influenced this shift, since strongly lateralized children exhibited a greater use of their preferred hand than less lateralized ones for actions in the contralateral hemispace. These findings confirm that hand selection is to some extent adaptable to task demand and environmental context.

Influence of object spatial location and task complexity on children's use of their preferred hand depending on their handedness consistency.

The goal of the present study was to compare the use of the preferred versus the nonpreferred hand in children performing two tasks of different levels of complexity, in various positions in space. Right-handed and left-handed consistent children were compared to their inconsistent counterparts. The results showed that the general tendency to use one's preferred hand to grasp an object is more or less pronounced depending on the object's spatial location and the task's complexity. The children used their preferred hand more often even when the object was presented contralaterally, and did so to a greater extent during the more complex task. Inconsistent-handers were more likely to shift to using their nonpreferred hand when the object was presented to this hand's side. Finally, we found that the influence of handedness consistency on hand use for the spatial positions varied with the complexity of the task. These results favor a view of handedness as a dynamic process in which motor preferences interact with task demand, probably through task-related attention.

Wrist and Forearm Movements While Homing in on Precision Targets

To determine whether people employed different movement strategies when they homed in on precision targets during repetitive tapping tasks, homing in movements were isolated for analysis. The time required to home in on the targets and the absolute magnitudes of peaks in joint velocities during homing in were calculated. In addition, the number of times that three types of corrective actions: changes in movement direction, inflections in velocity, and peaks in velocity, were made during pronation/supination and in radial/ulnar actions were counted. The number of times each type of corrective action was made was regressed against the time required for homing in. The relationships were highly linear, with correlation coefficients between 0.78 and 0.94. The implication was that corrective actions occurred at a similar mean frequency, regardless of the level of task precision and that homing in was a very active process at all levels of precision studied. The number of times any type of corrective action was taken increased significantly with increased precision (P < 0.001). The mean absolute magnitudes of pronation/supination and radial/ulnar velocities declined significantly with increased task precision (P < 0.001). However, the fact that the number of corrective actions increased with increased task precision showed that the movements toward the high precision targets were not just ‘slowed down’ versions of the movements to the low precision targets. Differences between the number of corrective actions, and the magnitudes of peak velocities for tasks of different levels of precision reflect different biomechanical stresses at the wrist and forearm for the different tasks. These differences are expected to result in different effects on shoulder muscles at different levels of precision.

Baseline blink rates and the effect of visual task difficulty and position of gaze

Purpose. To compare the baseline blink rates (BBR) measured under different (baseline) conditions, and to compare the blink rates measured when performing two visual tasks of different levels of difficulty at two positions of gaze. Methods. In the first single masked experiment, BBR were measured under three different conditions – (i) conversation with the subjects (ii) taking the visual acuity and (iii) keeping the subjects waiting in an empty examination room. In the second single masked experiment, the subjects were required to perform an easy task (reading normal English words) and a difficult task (reading mirror-image English words) at primary gaze and down gaze. The orders of the tasks performed were randomly allocated. Results. BBR taken under the three different conditions were significantly different from each other. No significant difference was found between the blink rates measured when performing the two reading tasks if they were performed at the same position of gaze. The mean blink rates were significantly lower when performing the tasks at down gaze than when performing the tasks at primary gaze. No significant differences were found between BBR-waiting and blink rate measured when the subject was doing the easy task at primary gaze, and between BBR-VA and blink rate measured when the subject was performing the difficult task at primary gaze. Conclusions. BBR measured under different (baseline) conditions produced different results so it is important for investigators to describe the baseline condition very clearly in studies where BBR are measured. Our results also indicated that mean blink rate was affected by the position of gaze and not the level of task difficulty.

Baseline blink rates and the effect of visual task difficulty and position of gaze

To compare the baseline blink rates (BBR) measured under different (baseline) conditions, and to compare the blink rates measured when performing two visual tasks of different levels of difficulty at two positions of gaze. In the first single masked experiment, BBR were measured under three different conditions - (i) conversation with the subjects (ii) taking the visual acuity and (iii) keeping the subjects waiting in an empty examination room. In the second single masked experiment, the subjects were required to perform an easy task (reading normal English words) and a difficult task (reading mirror-image English words) at primary gaze and down gaze. The orders of the tasks performed were randomly allocated. BBR taken under the three different conditions were significantly different from each other. No significant difference was found between the blink rates measured when performing the two reading tasks if they were performed at the same position of gaze. The mean blink rates were significantly lower when performing the tasks at down gaze than when performing the tasks at primary gaze. No significant differences were found between BBR-waiting and blink rate measured when the subject was doing the easy task at primary gaze, and between BBR-VA and blink rate measured when the subject was performing the difficult task at primary gaze. BBR measured under different (baseline) conditions produced different results so it is important for investigators to describe the baseline condition very clearly in studies where BBR are measured. Our results also indicated that mean blink rate was affected by the position of gaze and not the level of task difficulty.

Target Localisation and Identification in Rapid Visual Search

In recent models of visual search in has been proposed that, in rapid parallel search, information about the location of a target pattern among distractors and information about its identity would not be available simultaneously, but that target location is represented at earlier stages of visual processing than target identity. In the present study, the priority of location information over identity information in parallel visual search was investigated by means of one identification and two localisation tasks of different levels of difficulty. In all three tasks, the stimulus display was identical An oblique line segment, randomly 45 degrees or 135 degrees in orientation, was presented randomly at one quadrant of the display. In the identification task, the observer reported the orientation of the oblique line irrespective of its location. In the easy localisation task, the observer indicated whether the oblique line was at the left or right side of the display, and in the difficult localisation task whether it was in the upper or lower part of the display. In both localisation tasks, the observer ignored the orientation of the target line. The oblique line was accompanied by one, five, seventeen, or thirty-nine vertical distractor line segments in all tasks. The results showed that the response speed in the left vs right localisation was faster than in the identification task, whereas performance in the up vs down localisation was inferior. When the response factors (stimulus-response compatibility) in the left vs right localisation were taken into account, there were no performance differences between localisation and identification. Thus, these results demonstrated that direct performance comparisons between localisation and identification may be somewhat arbitrary, and they do not solve the issue of priority of location or identity information in rapid visual search.

Sex differences in reaction times, decision times, and movement times in British and Korean children.

In this study we compared reaction times broken down into decision times and movement times between 9-year-old British and Korean boys and girls. Boys tended to be faster on movement times, but there was no sex difference in decision times. These results were obtained on three reaction-time tasks of different levels of complexity.

Hearer-effects on speaker performances: the influence of the hearer on speakers' effectiveness in oral communication tasks

Experiments were conducted to investigate the oral communication skills of 14 to 16-year-olds and to discover conditions which elicit the best spoken performances. Several conditions were tested, using instructional tasks of different levels of difficulty with speakers of various academic abilities. The performances were scored objectively, using as a criterion the amount of relevant information included by speakers in their instructions. The presence of a hearer and ex periencing of the tasks in ascending order of difficulty both resulted in better spoken performances. Prior experience in the hearer's role proved particularly beneficial in sensitizing speakers to their hearer's information requirements. From these results simple training tech niques are outlined for eliciting competent spoken performances in schools.

Assimilation resistance and affective response in problem solving

In a problem solving experiment, predictions were based upon a theory of motivation and action, the scheme theory, and a psychometric model for the component analysis of rating data, the sector model (Eckblad, 1981; 1980). Pattern guessing tasks were presented to 32 students, 8 to each subject, in individual sessions lasting more than one hour. Number of errors, rated attractiveness, and guessing latencies (the process variables) were recorded during each task. After completion of each task, the affective reaction to it was assessed by means of ratings on six scales, including the scales Pleasant, Interesting, and Complex. On the basis of the sector model, an index of assimilation resistance was computed from the ratings of each task/subject unit, and the index was used to predict mean values and gradients for the process variables. Results show that the sector structure is clearly present in the rating data, that the process variables fit into the structure in the predicted manner, and that mean values and gradients for the process variables differ highly significantly and as predicted among tasks of different levels of assimilation resistance.

Great Britain's Industrial Training Act

This magazine presented in its February and May 1966 issues the first six chapters of Dr. John Welch's "Task Unit Approach to On-The- Job Training." In June 1966, Britain's Hotel & Catering Institute Journal published excerpts of these articles from The Quarterly. In July, the same journal published the British Hotel and Catering Industry Training Committee's report which recommended that a task-unit approach to education for the industry be adopted by their government. Education for the hospitality industry is to be given in four general categories: 1) Food Prep aration and Cookery; 2) Food Service; 3) Front Office; and 4) Housekeeping. A "sandwich ap proach"-alternating periods of classroom in struction with on-the-job training- is recom mended in mastering tasks of different levels in any one of these four departments. Certificates of competency are to be awarded to trainees who successfully master each task level. Employers who provide on-the-job training approved by the Committee will receive government aid from the education levy placed on all establishments in the industry.-Editor