Science.gov

Sample records for effects task group

  1. Effect of Work Group Size and Task Size on Observers' Job Characteristics Ratings.

    ERIC Educational Resources Information Center

    Greenberg, Carl I.; And Others

    The Job Characteristics Model proposed by Hackman and his associates postulates that positive personal and work outcomes are derived from five core job dimensions: skill variety, task identity, task significance, autonomy, and feedback from the job. The effects of the number of workers (work group size) and the number of tasks (task size) on…

  2. Management Agenda Task Group

    DTIC Science & Technology

    2005-02-01

    Report FY04-4 • Recommendations related to business management priorities for the Secretary of Defense February...Business Board (DBB) formed this Task Group to assess and make recommendations to the Department of Defense on management priorities for the next four...This list should be drawn from the four primary areas of DBB focus over the past three years: human resources, financial management, acquisition

  3. Effects of Training on Computer-Mediated Communication in Single or Mixed Gender Small Task Groups.

    ERIC Educational Resources Information Center

    Savicki, Victor; Kelley, Merle; Ammon, Benjamin

    2002-01-01

    Investigates group gender composition and communication styles in small task groups involved in computer-mediated communication. Describes a study that tried to train small task groups in the use of one communication style and suggests further research in the area of communication training for online task groups. (Author/LRW)

  4. Collective Efficacy and Group Functioning: The Effect of Performance Feedback on Efficacy Assessments, Goal Setting, Task Persistence and Overall Performance

    DTIC Science & Technology

    2002-08-01

    This study examined the effect of collective efficacy on group functioning across a series of cognitive tasks. Specifically, this experiment used...performance feedback to manipulate efficacy levels in order to investigate the effect of efficacy on group goal setting, task persistence, and overall...performance. The effect of experimental manipulations and sequence were investigated at both the task specific (prediction for current task) and general

  5. Effects of n-dominance and group composition on task efficiency in laboratory triads.

    NASA Technical Reports Server (NTRS)

    Lampkin, E. C.

    1972-01-01

    Task-oriented triads were formed into various homogeneous and heterogeneous combinations according to their scores on the n-dominance personality trait of the Edwards Personal Preference Schedule. Five group categories were used. The group task required a consensus decision on each trial. High cooperation and interdependence were reinforced by partially restricting the communication network. Results showed heterogeneous groups significantly better at organizing their group communication processes. They consequently performed the task more efficiently than homogeneous triads.

  6. Task Group for Orthodontics Report.

    PubMed

    Lumsden, K W; Brown, D V; Edler, R J; Kirschen, R H; Macadam, T S; Stephens, C D

    1998-08-01

    The UK Specialist Review Group of the General Dental Council's Education Committee has been charged with taking forward the recommendations in the Chief Dental Officer's report 'UK Specialist Dental Training'. The Specialist Review Group has, in turn, established a number of specialty task groups. This report is from the Task Group for Orthodontics. It was submitted in May 1996.

  7. Test-Retest Reliability in fMRI of Language: Group and Task Effects

    ERIC Educational Resources Information Center

    Chen, E. Elinor; Small, Steven L.

    2007-01-01

    This paper explores how the test-retest reliability is modulated by different groups of participants and experimental tasks. A group of 12 healthy participants and a group of nine stroke patients performed the same language imaging experiment twice, test and retest, on different days. The experiment consists of four conditions, one audio condition…

  8. Collective Validation in Multi-Actor Task Groups: The Effects of Status Differentiation

    ERIC Educational Resources Information Center

    Kalkhoff, Will

    2005-01-01

    Berger and his colleagues argue that collective validation (i.e., group members' corroboration of deferential behavior) is an important source of legitimacy in informal task groups. This invites the question "What causes collective validation?" Drawing from Simmel and Blau in particular, I develop an explanation of collective validation that…

  9. Preschoolers Learn Cognitive Tasks in Groups.

    ERIC Educational Resources Information Center

    Cahoon, Owen W.

    The present study was designed to assess the effectiveness of certain cognitive training tasks on children in group settings under natural preschool conditions. Thirty-five children, aged 47-63 months, were divided into six experimental groups and received various cognitive tasks. Results indicated that most children experienced at least moderate…

  10. Task Group 9 Update (Presentation)

    SciTech Connect

    Bosco, N.

    2014-04-01

    This presentation is a brief update of IEC TC82 QA Task Force, Group 9. Presented is an outline of the recently submitted New Work Item Proposal (NWIP) for a Comparative Thermal Cycling Test for CPV Modules to Differentiate Thermal Fatigue Durability.

  11. Dosimetric effects caused by couch tops and immobilization devices: Report of AAPM Task Group 176

    SciTech Connect

    Olch, Arthur J.; Gerig, Lee; Li, Heng; Mihaylov, Ivaylo; Morgan, Andrew

    2014-06-15

    The dosimetric impact from devices external to the patient is a complex combination of increased skin dose, reduced tumor dose, and altered dose distribution. Although small monitor unit or dose corrections are routinely made for blocking trays, ion chamber correction factors, e.g., accounting for temperature and pressure, or tissue inhomogeneities, the dose perturbation of the treatment couch top or immobilization devices is often overlooked. These devices also increase skin dose, an effect which is also often ignored or underestimated. These concerns have grown recently due to the increased use of monolithic carbon fiber couch tops which are optimal for imaging for patient position verification but cause attenuation and increased skin dose compared to the “tennis racket” style couch top they often replace. Also, arc delivery techniques have replaced stationary gantry techniques which cause a greater fraction of the dose to be delivered from posterior angles. A host of immobilization devices are available and used to increase patient positioning reproducibility, and these also have attenuation and skin dose implications which are often ignored. This report of Task Group 176 serves to present a survey of published data that illustrates the magnitude of the dosimetric effects of a wide range of devices external to the patient. The report also provides methods for modeling couch tops in treatment planning systems so the physicist can accurately compute the dosimetric effects for indexed patient treatments. Both photon and proton beams are considered. A discussion on avoidance of high density structures during beam planning is also provided. An important aspect of this report are the recommendations the authors make to clinical physicists, treatment planning system vendors, and device vendors on how to make measurements of surface dose and attenuation and how to report these values. For the vendors, an appeal is made to work together to provide accurate couch top

  12. Effects of individualized versus group task-oriented circuit training on balance ability and gait endurance in chronic stroke inpatients.

    PubMed

    Kim, Bonggil; Park, Yunjin; Seo, Yonggon; Park, Sangseo; Cho, Hyeyoung; Moon, Hyunghoon; Lee, Haelim; Kim, Myungki; Yu, Jaeho

    2016-06-01

    [Purpose] The purpose of this study was to analyze the effects of task-oriented circuit training on the balance ability and gait endurance of chronic stroke inpatients. [Subjects and Methods] The participants were 30 patients who had stroke >6 months previously, resulting in a disability such as hemiparesis. The participants were randomly divided into the group task-oriented circuit training group and the individual task-oriented circuit-training group. They performed eight types of modified task-oriented training. Balance ability and gait endurance were measured by using the Berg balance scale questionnaire and the 6-min walk test, respectively, before and after the experiment. [Results] Significant differences were observed between before and after the intervention in all variables. There was a significant difference between groups in Berg balance scale scores; however, no significant differences were seen in the timed up and go test and the 6-min walk test. [Conclusion] The results of this study indicated that group exercise can better improve the balance ability of chronic stroke inpatients after stroke than can individualized exercise intervention.

  13. The unilateral field advantage in repetition detection: effects of perceptual grouping and task demands.

    PubMed

    Hayes, Matthew T; Swallow, Khena M; Jiang, Yuhong V

    2010-04-01

    This study examines interhemispheric interactions in detecting objects that are simultaneously repeated in an array of objects. Previous studies have shown that presenting two identical objects to a single hemifield speeds up repetition detection. This unilateral field advantage (UFA) is often attributed to the relatively low-level processing demands for detecting a perceptual repetition, and more specifically, to more efficient perceptual grouping processes within a hemisphere than between hemispheres. To directly examine the impact of perceptual grouping and task demands on interhemispheric interactions, we asked participants to judge whether four items, one presented in each visual quadrant, were all different, or whether any two were the same, along an instructed dimension. We found that in comparison with the UFA for identical objects, the UFA for repetition detection in accuracy was similar or greater when the matching objects were not perceptually identical and differed in color, size, or viewpoint. Thus, decreasing grouping strength and increasing computational complexity did not reduce the UFA. Results are interpreted in terms of the callosal degradation account of the UFA.

  14. Return to Flight Task Group

    NASA Technical Reports Server (NTRS)

    2005-01-01

    It has been 29 months since Columbia was lost over East Texas in February 2003. Seven months after the accident, the Columbia Accident Investigation Board (CAIB) released the first volume of its final report, citing a variety of technical, managerial, and cultural issues within NASA and the Space Shuttle Program. To their credit, NASA offered few excuses, embraced the report, and set about correcting the deficiencies noted by the accident board. Of the 29 recommendations issued by the CAIB, 15 were deemed critical enough that the accident board believed they should be implemented prior to returning the Space Shuttle to flight. Some of these recommendations were relatively easy, most were straightforward, a few bordered on the impossible, and others were largely overcome by events, particularly the decision by the President to retire the Space Shuttle by 2010. The Return to Flight Task Group (RTF TG, or simply, the Task Group) was chartered by the NASA Administrator in July 2003 to provide an independent assessment of the implementation of the 15 CAIB return-to-flight recommendations. An important observation must be stated up-front: neither the CAIB nor the RTF TG believes that all risk can be eliminated from Space Shuttle operations; nor do we believe that the Space Shuttle is inherently unsafe. What the CAIB and RTF TG do believe, however, is that NASA and the American public need to understand the risks associated with space travel, and that NASA must make every reasonable effort to minimize such risk. Since the release of the CAIB report, NASA and the Space Shuttle Program expended enormous effort and resources toward correcting the causes of the accident and preparing to fly again. Relative to the 15 specific recommendations that the CAIB indicated should be implemented prior to returning to flight, NASA has met or exceeded most of them the Task Group believes that NASA met the intent of the CAIB for 12 of these recommendations. The remaining three

  15. The Indirect Effect of Age Group on Switch Costs via Gray Matter Volume and Task-Related Brain Activity

    PubMed Central

    Steffener, Jason; Gazes, Yunglin; Habeck, Christian; Stern, Yaakov

    2016-01-01

    Healthy aging simultaneously affects brain structure, brain function, and cognition. These effects are often investigated in isolation ignoring any relationships between them. It is plausible that age related declines in cognitive performance are the result of age-related structural and functional changes. This straightforward idea is tested in within a conceptual research model of cognitive aging. The current study tested whether age-related declines in task-performance were explained by age-related differences in brain structure and brain function using a task-switching paradigm in 175 participants. Sixty-three young and 112 old participants underwent MRI scanning of brain structure and brain activation. The experimental task was an executive context dual task with switch costs in response time as the behavioral measure. A serial mediation model was applied voxel-wise throughout the brain testing all pathways between age group, gray matter volume, brain activation and increased switch costs, worsening performance. There were widespread age group differences in gray matter volume and brain activation. Switch costs also significantly differed by age group. There were brain regions demonstrating significant indirect effects of age group on switch costs via the pathway through gray matter volume and brain activation. These were in the bilateral precuneus, bilateral parietal cortex, the left precentral gyrus, cerebellum, fusiform, and occipital cortices. There were also significant indirect effects via the brain activation pathway after controlling for gray matter volume. These effects were in the cerebellum, occipital cortex, left precentral gyrus, bilateral supramarginal, bilateral parietal, precuneus, middle cingulate extending to medial superior frontal gyri and the left middle frontal gyri. There were no significant effects through the gray matter volume alone pathway. These results demonstrate that a large proportion of the age group effect on switch costs can

  16. The Indirect Effect of Age Group on Switch Costs via Gray Matter Volume and Task-Related Brain Activity.

    PubMed

    Steffener, Jason; Gazes, Yunglin; Habeck, Christian; Stern, Yaakov

    2016-01-01

    Healthy aging simultaneously affects brain structure, brain function, and cognition. These effects are often investigated in isolation ignoring any relationships between them. It is plausible that age related declines in cognitive performance are the result of age-related structural and functional changes. This straightforward idea is tested in within a conceptual research model of cognitive aging. The current study tested whether age-related declines in task-performance were explained by age-related differences in brain structure and brain function using a task-switching paradigm in 175 participants. Sixty-three young and 112 old participants underwent MRI scanning of brain structure and brain activation. The experimental task was an executive context dual task with switch costs in response time as the behavioral measure. A serial mediation model was applied voxel-wise throughout the brain testing all pathways between age group, gray matter volume, brain activation and increased switch costs, worsening performance. There were widespread age group differences in gray matter volume and brain activation. Switch costs also significantly differed by age group. There were brain regions demonstrating significant indirect effects of age group on switch costs via the pathway through gray matter volume and brain activation. These were in the bilateral precuneus, bilateral parietal cortex, the left precentral gyrus, cerebellum, fusiform, and occipital cortices. There were also significant indirect effects via the brain activation pathway after controlling for gray matter volume. These effects were in the cerebellum, occipital cortex, left precentral gyrus, bilateral supramarginal, bilateral parietal, precuneus, middle cingulate extending to medial superior frontal gyri and the left middle frontal gyri. There were no significant effects through the gray matter volume alone pathway. These results demonstrate that a large proportion of the age group effect on switch costs can

  17. Group Motivation and Group Task Performance: The Expectancy-Valence Theory Approach.

    ERIC Educational Resources Information Center

    Nakanishi, Masayuki

    1988-01-01

    Investigated effects of group motivation on group task performance. Created two levels of valence, expectancy and instrumentality. Valence variable reflected on group productivity on unstructured and task persistence measures. Expectancy variable's effect was on task persistence measure. Instrumentality affected group productivity on structured…

  18. The Effects of Group Relaxation Training/Large Muscle Exercise, and Parental Involvement on Attention to Task, Impulsivity, and Locus of Control among Hyperactive Boys.

    ERIC Educational Resources Information Center

    Porter, Sally S.; Omizo, Michael M.

    1984-01-01

    The study examined the effects of group relaxation training/large muscle exercise and parental involvement on attention to task, impulsivity, and locus of control among 34 hyperactive boys. Following treatment both experimental groups recorded significantly higher attention to task, lower impulsivity, and lower locus of control scores. (Author/CL)

  19. Differential Effects of Task and Reinforcement Variables on the Performance of Three Groups of Behavior Problem Children

    ERIC Educational Resources Information Center

    Dietrich, Coralie

    1976-01-01

    In a test of H. Quay's model of differential response tendencies in three basic dimensions of discordant behavior, 36 delinquent boys (10 to 16 years old) divided into three behavior groups-Conduct Disorder, Personality Disorder, Inadequate-Immature-were compared on a verbal paired-associate task under four conditions of task structure: neutral…

  20. Identifying and Developing Leadership Aspects of Effective Management in Team-Oriented Task Groups. Technical Report 70-4.

    ERIC Educational Resources Information Center

    Fox, William M.

    Leadership is distinguished from management. A review of key leadership studies is presented. Data on leadership styles are presented, and problems in studying them are discussed. A normative model for leadership of team-oriented task groups based on current research findings is presented. Documented lead-lag relationships between leader behaviors…

  1. [The notion of task in focus groups].

    PubMed

    Dall'Agnol, Clarice Maria; de Magalhães, Ana Maria Müller; Mano, Gustavo Caetano de Mattos; Olschowsky, Agnes; da Silva, Flávia Pacheco

    2012-03-01

    The aim of this paper is to revisit the concept of task in light of Pichon-Riviére's referential and to discuss its application in research with focus groups. Focus groups are understood as a research technique which proposes to investigate a topic in depth, allowing the construction of new ideas and answers on the subject in focus. The presuppositions of operative groups were used to support the research practice with focus groups. In these, the notion of task has a key strategic position from which it seeks to intervene in society through dialogue and collective construction, unlike simple data collecting

  2. Working with Group-Tasks and Group Cohesiveness

    ERIC Educational Resources Information Center

    Anwar, Khoirul

    2016-01-01

    This study aimed at exploring the connection between the use of group task and group cohesiveness. This study is very important because the nature of the learner's success is largely determined by the values of cooperation, interaction, and understanding of the learning objectives together. Subjects of this study are 28 students on the course…

  3. Using the 5 P Relay in Task Groups

    ERIC Educational Resources Information Center

    Stanley, Paula Helen

    2006-01-01

    This article describes the 5 P Relay, a group exercise that can increase the effectiveness of task groups. The 5 P Relay is based on the principles and concepts of the Invitational Model, which emphasizes the importance of assessing the effectiveness or health of five aspects of an organization's environment: people, places, programs, processes,…

  4. Life Cycles of Ad Hoc Task Groups

    DTIC Science & Technology

    1983-10-01

    internal group dynamics, and external influence on the group . Time pressure . Members’ first comments about time pressure appeared at transition meetings...organizational supports and management behavior can influence team effectiveness. Yet it is unclear how such factors may affect the group "_.3...on members’ ability to work together, yet little is known about how the gradual creation of work products influences groups ’ social development. The

  5. Report of the Task Group on Federal Agency Evaluation,

    DTIC Science & Technology

    based on the examination and analysis of the agency’s total occupational safety and health program. Section II of this report is entitled, The Effective... Occupational Safety and Health Program . It describes how the task group thinks an effective occupational safety and health program should function and

  6. Does the mask govern the mind?: effects of arbitrary gender representation on quantitative task performance in avatar-represented virtual groups.

    PubMed

    Lee, Jong-Eun Roselyn; Nass, Clifford I; Bailenson, Jeremy N

    2014-04-01

    Virtual environments employing avatars for self-representation-including the opportunity to represent or misrepresent social categories-raise interesting and intriguing questions as to how one's avatar-based social category shapes social identity dynamics, particularly when stereotypes prevalent in the offline world apply to the social categories visually represented by avatars. The present experiment investigated how social category representation via avatars (i.e., graphical representations of people in computer-mediated environments) affects stereotype-relevant task performance. In particular, building on and extending the Proteus effect model, we explored whether and how stereotype lift (i.e., a performance boost caused by the awareness of a domain-specific negative stereotype associated with outgroup members) occurred in virtual group settings in which avatar-based gender representation was arbitrary. Female and male participants (N=120) were randomly assigned either a female avatar or a male avatar through a process masked as a random drawing. They were then placed in a numerical minority status with respect to virtual gender-as the only virtual female (male) in a computer-mediated triad with two opposite-gendered avatars-and performed a mental arithmetic task either competitively or cooperatively. The data revealed that participants who were arbitrarily represented by a male avatar and competed against two ostensible female avatars showed strongest performance compared to others on the arithmetic task. This pattern occurred regardless of participants' actual gender, pointing to a virtual stereotype lift effect. Additional mediation tests showed that task motivation partially mediated the effect. Theoretical and practical implications for social identity dynamics in avatar-based virtual environments are discussed.

  7. Animal behaviour: task differentiation by personality in spider groups.

    PubMed

    Grinsted, Lena; Bacon, Jonathan P

    2014-08-18

    In social animals, group efficiency is often assumed to increase with task differentiation, but this requires that individuals are better than generalists at the task they specialize in. A new study finds that individual Anelosimus studiosus spiders do predominantly perform the task they excel at, in line with their individual personality type, when they are placed in groups.

  8. Efficiency and Effectiveness in Higher Education: A Report by the Universities UK Efficiency and Modernisation Task Group

    ERIC Educational Resources Information Center

    Universities UK, 2011

    2011-01-01

    Effectiveness, efficiency and value for money are central concerns for the higher education sector. In England, decisions made by the current Government will effect a radical change in the funding for teaching. Institutions will be managing a reduction in public funding for teaching and the transition to the new system of graduate contributions,…

  9. Task Group on Strengthening the DoD Enterprise Governance

    DTIC Science & Technology

    2008-07-01

    Representative). Other Task Group Members included: John Madigan, Mark Ronald, Joe Wright, Jim Haveman from the DBB and Harold Brown, Jack Keane, and Jim...Executive Assistants, Mr. Brian Ferguson, Mr. Nelson Erickson Defense Business Board • Barbara Barrett (Co-Chair) • John Madigan • Mark Ronald • Joe...Effectiveness in the Public Sector – Joint Defense Capabilities Study (2003) (Aldridge Report) – Katzenbach Partners (April 2, 2008 Report on Senior

  10. Effective Task Design for the TBL Classroom

    ERIC Educational Resources Information Center

    Roberson, Bill; Franchini, Billie

    2014-01-01

    Group and team tasks are the culminating outputs of student learning in team and collaborative learning environments. How they are conceived and designed, therefore, can directly determine the success of the pedagogical strategy. A key design issue for creating effective tasks is how best to focus student knowledge, observation, and analysis…

  11. Habitual routines in task-performing groups

    NASA Technical Reports Server (NTRS)

    Gersick, C. J.; Hackman, J. R.

    1990-01-01

    Groups, like individuals, often develop habitual routines for dealing with frequently encountered stimuli. Although such routines are consequential for group life and work, little is known about them. This paper reconnoiters the territory of habitual behavior in groups that perform work within organizations. We offer a definition of group habits, identify their functions and dysfunctions, suggest how they develop and are maintained, and identify the circumstances when they are likely to be altered or abandoned. Throughout, we give special attention to the social nature of habitual routines in groups, to the interaction between habitual behavior and group life cycle phenomena, and to the role of the organizational context in prompting, shaping, and terminating habitual routines.

  12. National facilities study. Volume 4: Space operations facilities task group

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The principal objectives of the National Facilities Study (NFS) were to: (1) determine where U.S. facilities do not meet national aerospace needs; (2) define new facilities required to make U.S. capabilities 'world class' where such improvements are in the national interest; (3) define where consolidation and phase-out of existing facilities is appropriate; and (4) develop a long-term national plan for world-class facility acquisition and shared usage. The Space Operations Facilities Task Group defined discrete tasks to accomplish the above objectives within the scope of the study. An assessment of national space operations facilities was conducted to determine the nation's capability to meet the requirements of space operations during the next 30 years. The mission model used in the study to define facility requirements is described in Volume 3. Based on this model, the major focus of the Task Group was to identify any substantive overlap or underutilization of space operations facilities and to identify any facility shortfalls that would necessitate facility upgrades or new facilities. The focus of this initial study was directed toward facility recommendations related to consolidations, closures, enhancements, and upgrades considered necessary to efficiently and effectively support the baseline requirements model. Activities related to identifying facility needs or recommendations for enhancing U.S. international competitiveness and achieving world-class capability, where appropriate, were deferred to a subsequent study phase.

  13. Dynamic Task Performance, Cohesion, and Communications in Human Groups.

    PubMed

    Giraldo, Luis Felipe; Passino, Kevin M

    2016-10-01

    In the study of the behavior of human groups, it has been observed that there is a strong interaction between the cohesiveness of the group, its performance when the group has to solve a task, and the patterns of communication between the members of the group. Developing mathematical and computational tools for the analysis and design of task-solving groups that are not only cohesive but also perform well is of importance in social sciences, organizational management, and engineering. In this paper, we model a human group as a dynamical system whose behavior is driven by a task optimization process and the interaction between subsystems that represent the members of the group interconnected according to a given communication network. These interactions are described as attractions and repulsions among members. We show that the dynamics characterized by the proposed mathematical model are qualitatively consistent with those observed in real-human groups, where the key aspect is that the attraction patterns in the group and the commitment to solve the task are not static but change over time. Through a theoretical analysis of the system we provide conditions on the parameters that allow the group to have cohesive behaviors, and Monte Carlo simulations are used to study group dynamics for different sets of parameters, communication topologies, and tasks to solve.

  14. Task factor usability ratings for different age groups writing Chinese.

    PubMed

    Chan, A H S; So, J C Y

    2009-11-01

    This study evaluated how different task factors affect performance and user subjective preferences for three different age groups of Chinese subjects (6-11, 20-23, 65-70 years) when hand writing Chinese characters. The subjects copied Chinese character sentences with different settings for the task factors of writing plane angle (horizontal 0 degrees , slanted 15 degrees ), writing direction (horizontal, vertical), and line spacing (5 mm, 7 mm and no lines). Writing speed was measured and subjective preferences (effectiveness and satisfaction) were assessed for each of the task factor settings. The result showed that there was a conflict between writing speed and personal preference for the line spacing factor; 5 mm line spacing increased writing speed but it was the least preferred. It was also found that: vertical and horizontal writing directions and a slanted work surface suited school-aged children; a horizontal work surface and horizontal writing direction suited university students; and a horizontal writing direction with either a horizontal or slanted work surface suited the older adults.

  15. The Potential Effects of the Defense Business Board Military Compensation Task Group’s 2011 Recommendations on Active-Duty Service Member Retirement

    DTIC Science & Technology

    2012-12-01

    Plan 5 The military did not begin participating in the TSP until 2001. Although this is the case , the TSP has been in existence since 1986 when...Human Resource Strategy did not recommend cuts in military compensation due to the unfairness of the MRRA. Taking the lead from the DSB, Congress...per year (Henning, 2011). The task group drew three main conclusions from their study. First, the system is unfair because, due to the 20-year

  16. Task characteristics and the contextual interference effect.

    PubMed

    Kruisselbrink, L Darren; Van Gyn, Geraldine H

    2011-08-01

    The purpose of this exploratory study was to examine the influence of blocked and random practice on the acquisition and retention of a criterion multisegment motor task practiced alongside either two similar-distractors tasks or two different-distractors tasks. The random-practice similar-distractors group made more decision-making errors and performed the criterion task more slowly than the blocked-practice similar-distractors group during the acquisition phase. Following a brief filled retention interval, the blocked-practice similar-distractors group demonstrated a loss of acquired performance capabilities, whereas the random-practice similar-distractors group did not. The blocked- and random-practice different-distractors groups performed similarly throughout the experiment. Results are interpreted within Glenberg's component-levels theory, in which it was argued that random practice must stimulate the differential storage of multilevel contextual components associated with the multiple motor tasks being learned to produce a contextual interference effect. The theoretical and practical implications of differential storage versus nonrepetition as a function of random practice are discussed.

  17. Group Task Force on Satellite Rescue and Repair

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Group Task Force was chartered by the Administrator of NASA to recommend 'a policy outlining the criteria, the design standards, and the pricing model to guide NASA in assessing the responsibilities for government and nongovernment Satellite Rescue and Repair Missions.' Criteria for accepting such missions, risks, and benefits to all sectors of our economy involved in satellite services, adequacy of planning and training, and the impact on NASA's primary mission were reviewed. The Group began by asking a more fundamental question; is satellite rescue and repair a logical element of NASA's mission? Factors considered were: (1) the probability of rescue or repair opportunities arising; (2) the economic justification for such attempts; (3) the benefits to NASA, both from such ad hoc learning experiences in space operations and the impact on the public perception of NASA; (4) the effect of such unanticipated missions on NASA's scheduled activities; (5) any potential effect on NASA's technical capability to work in space; and (6) any potential effect on U.S. economic competitiveness.

  18. The Effect of Hierarchical Task Representations on Task Selection in Voluntary Task Switching

    ERIC Educational Resources Information Center

    Weaver, Starla M.; Arrington, Catherine M.

    2013-01-01

    The current study explored the potential for hierarchical representations to influence action selection during voluntary task switching. Participants switched between 4 individual task elements. In Experiment 1, participants were encouraged to represent the task elements as grouped within a hierarchy based on experimental manipulations of varying…

  19. Mapping Task Switching in Frontal Cortex Through Neuropsychological Group Studies

    PubMed Central

    Shallice, Tim; Stuss, Donald T.; Picton, Terence W.; Alexander, Michael P.; Gillingham, Susan

    2008-01-01

    This paper considers evidence provided by large neuropsychological group studies and meta-analyses of functional imaging experiments on the location in frontal cortex of the subprocesses involved in the carrying out of task-switching paradigms. The function of the individual subprocesses is also considered in the light of analyses of the performance of normal subjects. PMID:18982110

  20. Minimal Groups Increase Young Children's Motivation and Learning on Group-Relevant Tasks

    ERIC Educational Resources Information Center

    Master, Allison; Walton, Gregory M.

    2013-01-01

    Three experiments ("N" = 130) used a minimal group manipulation to show that just perceived membership in a social group boosts young children's motivation for and learning from group-relevant tasks. In Experiment 1, 4-year-old children assigned to a minimal "puzzles group" persisted longer on a challenging puzzle than children identified as the…

  1. TU-AB-BRD-00: Task Group 100

    SciTech Connect

    2015-06-15

    Current quality assurance and quality management guidelines provided by various professional organizations are prescriptive in nature, focusing principally on performance characteristics of planning and delivery devices. However, published analyses of events in radiation therapy show that most events are often caused by flaws in clinical processes rather than by device failures. This suggests the need for the development of a quality management program that is based on integrated approaches to process and equipment quality assurance. Industrial engineers have developed various risk assessment tools that are used to identify and eliminate potential failures from a system or a process before a failure impacts a customer. These tools include, but are not limited to, process mapping, failure modes and effects analysis, fault tree analysis. Task Group 100 of the American Association of Physicists in Medicine has developed these tools and used them to formulate an example risk-based quality management program for intensity-modulated radiotherapy. This is a prospective risk assessment approach that analyzes potential error pathways inherent in a clinical process and then ranks them according to relative risk, typically before implementation, followed by the design of a new process or modification of the existing process. Appropriate controls are then put in place to ensure that failures are less likely to occur and, if they do, they will more likely be detected before they propagate through the process, compromising treatment outcome and causing harm to the patient. Such a prospective approach forms the basis of the work of Task Group 100 that has recently been approved by the AAPM. This session will be devoted to a discussion of these tools and practical examples of how these tools can be used in a given radiotherapy clinic to develop a risk based quality management program. Learning Objectives: Learn how to design a process map for a radiotherapy process Learn how to

  2. Group membership affects spontaneous mental representation: failure to represent the out-group in a joint action task.

    PubMed

    McClung, Jennifer Susan; Jentzsch, Ines; Reicher, Stephen David

    2013-01-01

    Predicting others' actions is crucial to successful social interaction. Previous research on joint action, based on a reaction-time paradigm called the Joint Simon Task, suggests that successful joint action stems from the simultaneous representation of the self with the other. Performance on this task provides a read-out of the degree of intrusion from a partner that participants experience from acting jointly compared to acting alone, which in turn is a measure of the degree to which participants mentally represent their co-actors during the task. To investigate the role of perceived group membership in this type of joint action and its influence on the representation of others, we first subjected participants to a minimal group paradigm while manipulating differences in social competition. We then asked participants to do the Joint Simon Task in pairs with an in-group or out-group member. Only participants who acted with an "in-group" partner on the joint task showed altered reaction times compared to when acting alone, presumably a change caused by the simultaneous and automatic representation of their in-group partner. In contrast, participants who acted with an out-group partner were unaffected in their reactions when doing the joint task, showing no evidence of representation of their out-group partner. This effect was present in both the high-competition and low-competition conditions, indicating that the differential effects of group membership on representation during joint action were driven by perceived group membership and independent of the effects of social competition. We concluded that participants failed to represent out-group members as socially relevant agents not based on any personality or situational characteristics, but in reaction only to their status as "other". In this way group membership appears to affect cognition on a very immediate and subconscious level.

  3. The Effect of Feedback on Group Cohesiveness.

    ERIC Educational Resources Information Center

    Mears, Peter M.

    The effect of feedback on group cohesiveness (measured in terms of group and task attractiveness) for a person who is performing a simple, highly repetitive task was studied. One hundred business administration students, randomly assigned to five member groups, completed a series of trials having the goal of determining the number commonly held by…

  4. Governance - Alignment and Configuration of Business Activities Task Group Report

    DTIC Science & Technology

    2006-05-01

    governance level and the Enterprise Model as a way of ensuring integration at the management and work/execution levels 3. Ensure shared services (i.e...Management Framework o QDR Organizational Model o Secretary of Defense 2006-2008 Priorities o Shared Services Defense Business Board...support for horizontal and vertical organizations • Move “supporting” organizations to shared services model May 2006 "Team Defense" 18 Task Group

  5. The IUGS/IAGC Task Group on Global Geochemical Baselines

    USGS Publications Warehouse

    Smith, David B.; Wang, Xueqiu; Reeder, Shaun; Demetriades, Alecos

    2012-01-01

    The Task Group on Global Geochemical Baselines, operating under the auspices of both the International Union of Geological Sciences (IUGS) and the International Association of Geochemistry (IAGC), has the long-term goal of establishing a global geochemical database to document the concentration and distribution of chemical elements in the Earth’s surface or near-surface environment. The database and accompanying element distribution maps represent a geochemical baseline against which future human-induced or natural changes to the chemistry of the land surface may be recognized and quantified. In order to accomplish this long-term goal, the activities of the Task Group include: (1) developing partnerships with countries conducting broad-scale geochemical mapping studies; (2) providing consultation and training in the form of workshops and short courses; (3) organizing periodic international symposia to foster communication among the geochemical mapping community; (4) developing criteria for certifying those projects whose data are acceptable in a global geochemical database; (5) acting as a repository for data collected by those projects meeting the criteria for standardization; (6) preparing complete metadata for the certified projects; and (7) preparing, ultimately, a global geochemical database. This paper summarizes the history and accomplishments of the Task Group since its first predecessor project was established in 1988.

  6. [The effect of reading tasks on learning from multiple texts].

    PubMed

    Kobayashi, Keiichi

    2014-06-01

    This study examined the effect of reading tasks on the integration of content and source information from multiple texts. Undergraduate students (N = 102) read five newspaper articles about a fictitious incident in either a summarization task condition or an evaluation task condition. Then, they performed an integration test and a source choice test, which assessed their understanding of a situation described in the texts and memory for the sources of text information. The results indicated that the summarization and evaluation task groups were not significantly different in situational understanding. However, the summarization task group significantly surpassed the evaluation task group for source memory. No significant correlation between the situational understanding and the source memory was found for the summarization group, whereas a significant positive correlation was found for the evaluation group. The results are discussed in terms of the documents model framework.

  7. Effect of Generic Advance Instructions on Learning a Classification Task.

    ERIC Educational Resources Information Center

    Ellis, John A.; And Others

    1986-01-01

    This study investigated whether giving students generic advance instructions about how to learn classification tasks was effective in facilitating learning of a specific classification task. Results showed that the instruction group and adjunct-questions group did equally well on classifying new and old instances of U.S. Navy call signs.…

  8. Operation Ivy. Report of commander, Task Group 132. 1. Pacific Proving Grounds. Joint Task Force 132

    SciTech Connect

    Burriss, S.W.

    1984-10-31

    The mission of the Task Group included the responsibilities to conduct experimental measurement programs on Shots Mike and King and to conduct the radiological safety program. Programs were established to make radiochemical analysis of bomb debris; to follow the progress of the nuclear reaction; to make neutron, gamma-ray, blast, thermal radiation, and electromagnetic measurements; and to make a preliminary geophysical and marine survey of the test area. The organizational structure and command relations to accomplish the mission are outlined.

  9. The Task Demonstration Model: A Concurrent Model for Teaching Groups of Students with Severe Disabilities.

    ERIC Educational Resources Information Center

    Karsh, Kathryn G.; Repp, Alan C.

    1992-01-01

    This study investigated the use of the Task Demonstration Model (TDM) with 3 groups of students (ages 16-21) with severe or moderate retardation and compared it with the Standard Prompting Hierarchy. Percent and rate of correct responses indicate that TDM can be effective in a concurrent model of group instruction. (Author/JDD)

  10. Minimal groups increase young children's motivation and learning on group-relevant tasks.

    PubMed

    Master, Allison; Walton, Gregory M

    2013-01-01

    Three experiments (N = 130) used a minimal group manipulation to show that just perceived membership in a social group boosts young children's motivation for and learning from group-relevant tasks. In Experiment 1, 4-year-old children assigned to a minimal "puzzles group" persisted longer on a challenging puzzle than children identified as the "puzzles child" or children in a control condition. Experiment 2 showed that this boost in motivation occurred only when the group was associated with the task. In Experiment 3, children assigned to a minimal group associated with word learning learned more words than children assigned an analogous individual identity. The studies demonstrate that fostering shared motivations may be a powerful means by which to shape young children's academic outcomes.

  11. Task Switching Effects in Anticipation Timing

    ERIC Educational Resources Information Center

    Fairbrother, Jeffrey T.; Brueckner, Sebastian

    2008-01-01

    To understand how task switching affects human performance, there is a need to investigate how it influences the performance of tasks other than those involving bivalent stimulus categorization. The purpose of this study, therefore, was to investigate the effects of task switching on anticipation timing performance, which typically requires…

  12. Workshift and Antihistamine Effects on Task Performance.

    DTIC Science & Technology

    1997-12-01

    chlorpheniramine maleate), and time on task accompanying three successive drug doses spaced every four hours. Five performance tasks, two work sample tasks, and...four subjective scales were included in the study. In summary, chlorpheniramine maleate alone had a strong negative influence on a wide range of task...Day Shift tended to get better and during the Mid shift tended to get worse. No evidence was found that chlorpheniramine maleate and work shift combine to produce a multiplicative effect.

  13. A Demands-Resources Model of Work Pressure in IT Student Task Groups

    ERIC Educational Resources Information Center

    Wilson, E. Vance; Sheetz, Steven D.

    2010-01-01

    This paper presents an initial test of the group task demands-resources (GTD-R) model of group task performance among IT students. We theorize that demands and resources in group work influence formation of perceived group work pressure (GWP) and that heightened levels of GWP inhibit group task performance. A prior study identified 11 factors…

  14. Framing Effects: Dynamics and Task Domains

    PubMed

    Wang

    1996-11-01

    The author examines the mechanisms and dynamics of framing effects in risky choices across three distinct task domains (i.e., life-death, public property, and personal money). The choice outcomes of the problems presented in each of the three task domains had a binary structure of a sure thing vs a gamble of equal expected value; the outcomes differed in their framing conditions and the expected values, raging from 6000, 600, 60, to 6, numerically. It was hypothesized that subjects would become more risk seeking, if the sure outcome was below their aspiration level (the minimum requirement). As predicted, more subjects preferred the gamble when facing the life-death choice problems than facing the counterpart problems presented in the other two task domains. Subjects' risk preference varied categorically along the group size dimension in the life-death domain but changed more linearly over the expected value dimension in the monetary domain. Framing effects were observed in 7 of 13 pairs of problems, showing a positive frame-risk aversion and negative frame-risk seeking relationship. In addition, two types of framing effects were theoretically defined and empirically identified. A bidirectional framing effect involves a reversal in risk preference, and occurs when a decision maker's risk preference is ambiguous or weak. Four bidirectional effects were observed; in each case a majority of subjects preferred the sure outcome under a positive frame but the gamble under a negative frame. In contrast, a unidirectional framing effect refers to a preference shift due to the framing of choice outcomes: A majority of subjects preferred one choice outcome (either the sure thing or the gamble) under both framing conditions, with positive frame augmented the preference for the sure thing and negative frame augmented the preference for the gamble. These findings revealed some dynamic regularities of framing effects and posed implications for developing predictive and testable

  15. Characteristics of work groups and their relationship with social and task cohesion in student teams.

    PubMed

    Forrester, William R; Tashchian, Armen

    2004-08-01

    Results of an exploratory study of relationships between work-group characteristics and the social and task cohesion of 18 business students engaged in team class projects. Regression analysis of scores on workload sharing, team spirit, task flexibility, and team cohesiveness for scales of the Work Group Characteristics Inventory indicated sharing of the workload was significantly associated with both task and social cohesion; team spirit with task cohesion but not social cohesion; and task flexibility with social cohesion but not task cohesion.

  16. Steam Generator Group Project. Task 6. Channel head decontamination

    SciTech Connect

    Allen, R.P.; Clark, R.L.; Reece, W.D.

    1984-08-01

    The Steam Generator Group Project utilizes a retired-from-service pressurized-water-reactor steam generator as a test bed and source of specimens for research. An important preparatory step to primary side research activities was reduction of the radiation field in the steam generator channel head. This task report describes the channel head decontamination activities. Though not a programmatic research objective it was judged beneficial to explore the use of dilute reagent chemical decontamination techniques. These techniques presented potential for reduced personnel exposure and reduced secondary radwaste generation, over currently used abrasive blasting techniques. Two techniques with extensive laboratory research and vendors prepared to offer commercial application were tested, one on either side of the channel head. As indicated in the report, both techniques accomplished similar decontamination objectives. Neither technique damaged the generator channel head or tubing materials, as applied. This report provides details of the decontamination operations. Application system and operating conditions are described.

  17. Paternal Effectiveness in a Selected Cognitive Task.

    ERIC Educational Resources Information Center

    Acuff, Nancy Hamblen

    The immediate effectiveness of paternal instruction in a selected cognitive task was investigated. The sub-problems were (1) to compare paternal and maternal instruction, and (2) to analyze paternal instructional effectiveness with the son or the daughter. The cognitive task selected was the Goodenough-Harris Draw-A-Man Test. Subjects were 42…

  18. Teachers as Designers of Effective Numeracy Tasks

    ERIC Educational Resources Information Center

    Geiger, Vince

    2016-01-01

    In this paper, preliminary research into an effective approach to numeracy task design is described and analysed using a conceptual framework based on two dimensions--one related to the nature of numeracy and the other concerned with the characteristics of effective mathematical tasks. A case that documents one teacher's attempt to create a…

  19. Effects of adaptive task allocation on monitoring of automated systems.

    PubMed

    Parasuraman, R; Mouloua, M; Molloy, R

    1996-12-01

    The effects of adaptive task allocation on monitoring for automation failure during multitask flight simulation were examined. Participants monitored an automated engine status task while simultaneously performing tracking and fuel management tasks over three 30-min sessions. Two methods of adaptive task allocation, both involving temporary return of the automated engine status task to the human operator ("human control"), were examined as a possible countermeasure to monitoring inefficiency. For the model-based adaptive group, the engine status task was allocated to all participants in the middle of the second session for 10 min, following which it was again returned to automation control. The same occurred for the performance-based adaptive group, but only if an individual participant's monitoring performance up to that point did not meet a specified criterion. For the nonadaptive control groups, the engine status task remained automated throughout the experiment. All groups had low probabilities of detection of automation failures for the first 40 min spent with automation. However, following the 10-min intervening period of human control, both adaptive groups detected significantly more automation failures during the subsequent blocks under automation control. The results show that adaptive task allocation can enhance monitoring of automated systems. Both model-based and performance-based allocation improved monitoring of automation. Implications for the design of automated systems are discussed.

  20. Indiana University High Energy Physics Group, Task C

    SciTech Connect

    Heinz, R.M.; Mufson, S.L.; Musser, J.

    1991-01-01

    The Indiana University High Energy Physics Group, Task C has been actively involved in the MACRO experiment at Gran Sasso and the SSC experiment L during the current contract year. MACRO is a large US-Italian Monopole, Astrophysics, and Cosmic Ray Observatory being built under the Gran Sasso Mountain outside of Rome. Indiana University is in charge of organizing the United States software effort. We have built a state-of-the-art two-meter spectrophotometer for the MACRO liquid scintillator. We are in charge of ERP, the Event Reconstruction Processor online trigger processor for muons and stellar collapse. We are designing an air Cerenkov array to be placed on top of the Gran Sasso. Our other activity involves participation in the SSC experiment L. As long-standing members of L we have done proposal writing and have worked on important L planning and organization matters. We are now doing development work on the L Central Tracker straw drift tubes, including gas optimization, readout, and Monte Carlos. 12 refs., 20 figs., 1 tab.

  1. Cognate effects in bilingual language comprehension tasks.

    PubMed

    Yudes, Carolina; Macizo, Pedro; Bajo, Teresa

    2010-05-12

    We examined cognate effects when late fluent Spanish/English bilingual speakers undergoing event-related potential recordings performed two tasks on word pairs. In an association decision task, participants decided whether or not pairs of Spanish words were related in meaning. In a translation decision task, they reported whether English target words were correct translations of Spanish primes. In both the tasks, word primes were either cognates or noncognates. In the translation decision task, faster and more accurate responses were associated with reduced N400 amplitudes in word pairs featuring a cognate. However, cognates did not modulate performance or event-related potentials in the association decision task. The results suggest that language coactivation in bilingual speakers is modulated by cognitive context.

  2. The impacts of hypnotic susceptibility on chaotic dynamics of EEG signals during standard tasks of Waterloo-Stanford Group Scale.

    PubMed

    Yargholi, Elahe'; Nasrabadi, Ali Motie

    2013-05-01

    Chaotic features of hypnotic EEG (electroencephalograph), recorded during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility (WSGS), were used to investigate the underlying dynamic of tasks and analyse the effect of hypnotic depth and concentration on EEG signals. Results demonstrate: (1) More efficiency of Higuchi dimension in comparison with Correlation dimension to distinguish subjects from different hypnotizable groups, (2) Channels with significantly different chaotic features among people from various hypnotizability levels in tasks, (3) High level of consistency among discriminating channels of tasks with function of brain's lobes, (4) Most affectability of medium hypnotizable subjects and (5) Rise in fractal dimensions due to increase in hypnosis depth.

  3. Effects of a no-go Task 2 on Task 1 performance in dual - tasking: From benefits to costs.

    PubMed

    Janczyk, Markus; Huestegge, Lynn

    2017-04-01

    When two tasks are combined in a dual-task experiment, characteristics of Task 2 can influence Task 1 performance, a phenomenon termed the backward crosstalk effect (BCE). Besides instances depending on the (spatial) compatibility of both responses, a particularly interesting example was introduced by Miller (2006): If Task 2 was a no-go task (i.e., one not requiring any action at all), responses were slowed in Task 1. Subsequent work, however, also reported the opposite result-that is, faster Task 1 responses in cases of no-go Task 2 trials. We report three experiments aiming to more precisely identify the conditions under which a no-go Task 2 facilitates or impedes Task 1 performance. The results suggest that an adverse no-go BCE is only observed when the Task 2 response(s) are sufficiently prepared in advance, yielding strong inhibitory control demands for Task 2 that eventually hamper Task 1 processing as well (i.e., inhibitory costs). If this is not the case, encountering a no-go Task 2 trial facilitates Task 1 performance, suggesting that the underlying task representation is reduced to a single - task. These results are discussed in the context of other recent work on BCEs and of recently suggested accounts of the no-go BCE.

  4. A Task Group Practitioner's Response to Waldo and Bauman's Article on Regrouping the Categorization of Group Work.

    ERIC Educational Resources Information Center

    Keel, Linda P.

    1998-01-01

    Argues that Waldo and Bauman's Goals and Process (GAP) matrix does not include task/work groups. Claims that it is not in the best interest of group work to undo or rework the Association for Specialists in Group Work's four core groups as a model. States that the field of group work needs a commonly shared framework/categorization from which to…

  5. Group Development of Effective Governance Teams

    ERIC Educational Resources Information Center

    Mar, Deborah Katherine

    2011-01-01

    Purpose. The purpose of this study was to identify and describe the behaviors of effective governance teams as they move through stages of group development during regular school board meetings, utilizing the task and process behaviors identified in the Group Development Assessment (Jones & Bearley, 1994). Methodology. This mixed-methods…

  6. Cortisol responses to a group public speaking task for adolescents: variations by age, gender, and race.

    PubMed

    Hostinar, Camelia E; McQuillan, Mollie T; Mirous, Heather J; Grant, Kathryn E; Adam, Emma K

    2014-12-01

    Laboratory social stress tests involving public speaking challenges are widely used for eliciting an acute stress response in older children, adolescents, and adults. Recently, a group protocol for a social stress test (the Trier Social Stress Test for Groups, TSST-G) was shown to be effective in adults and is dramatically less time-consuming and resource-intensive compared to the single-subject version of the task. The present study sought to test the feasibility and effectiveness of an adapted group public speaking task conducted with a racially diverse, urban sample of U.S. adolescents (N=191; 52.4% female) between the ages of 11 and 18 (M=14.4 years, SD=1.93). Analyses revealed that this Group Public Speaking Task for Adolescents (GPST-A) provoked a significant increase in cortisol production (on average, approximately 60% above baseline) and in self-reported negative affect, while at the same time avoiding excessive stress responses that would raise ethical concerns or provoke substantial participant attrition. Approximately 63.4% of participants exhibited an increase in cortisol levels in response to the task, with 59.2% of the total sample showing a 10% or greater increase from baseline. Results also suggested that groups of five adolescents might be ideal for achieving more uniform cortisol responses across various serial positions for speech delivery. Basal cortisol levels increased with age and participants belonging to U.S. national minorities tended to have either lower basal cortisol or diminished cortisol reactivity compared to non-Hispanic Whites. This protocol facilitates the recruitment of larger sample sizes compared to prior research and may show great utility in answering new questions about adolescent stress reactivity and development.

  7. Normative feedback effects on learning a timing task.

    PubMed

    Wulf, Gabriele; Chiviacowsky, Suzete; Lewthwaite, Rebecca

    2010-12-01

    This study investigated the influence of normative feedback on learning a sequential timing task. In addition to feedback about their performance per trial, two groups of participants received bogus normative feedback about a peer group's average block-to-block improvement after each block of 10 trials. Scores indicated either greater (better group) or less (worse group) than the average improvement, respectively. On the transfer test 1 day later which required producing novel absolute movement times, the better group demonstrated more effective learning than the worse group. These findings add to the mounting evidence that motivational factors affect motor skill learning.

  8. National facilities study. Volume 5: Space research and development facilities task group

    NASA Technical Reports Server (NTRS)

    1994-01-01

    With the beginnings of the U.S. space program, there was a pressing need to develop facilities that could support the technology research and development, testing, and operations of evolving space systems. Redundancy in facilities that was once and advantage in providing flexibility and schedule accommodation is instead fast becoming a burden on scarce resources. As a result, there is a clear perception in many sectors that the U.S. has many space R&D facilities that are under-utilized and which are no longer cost-effective to maintain. At the same time, it is clear that the U.S. continues to possess many space R&D facilities which are the best -- or among the best -- in the world. In order to remain world class in key areas, careful assessment of current capabilities and planning for new facilities is needed. The National Facility Study (NFS) was initiated in 1992 to develop a comprehensive and integrated long-term plan for future aerospace facilities that meets current and projected government and commercial needs. In order to assess the nation's capability to support space research and development (R&D), a Space R&D Task Group was formed. The Task Group was co-chaired by NASA and DOD. The Task Group formed four major, technologically- and functionally- oriented working groups: Human and Machine Operations; Information and Communications; Propulsion and Power; and Materials, Structures, and Flight Dynamics. In addition to these groups, three supporting working groups were formed: Systems Engineering and Requirements; Strategy and Policy; and Costing Analysis. The Space R&D Task Group examined several hundred facilities against the template of a baseline mission and requirements model (developed in common with the Space Operations Task Group) and a set of excursions from the baseline. The model and excursions are described in Volume 3 of the NFS final report. In addition, as a part of the effort, the group examined key strategic issues associated with space R

  9. Common region wins the competition between extrinsic grouping cues: Evidence from a task without explicit attention to grouping.

    PubMed

    Montoro, Pedro R; Villalba-García, Cristina; Luna, Dolores; Hinojosa, José A

    2017-03-01

    The competition between perceptual grouping factors is a relatively ignored topic, especially in the case of extrinsic grouping cues (e.g., common region or connectedness). Recent studies have examined the integration of extrinsic cues using tasks that induce selective attention to groups based on different grouping cues. However, this procedure could generate alternative strategies for task performance, which are non-related to the perceptual grouping operations. In the current work, we used an indirect task, i.e. repetition discrimination task, without explicit attention to grouping cues to further examine the rules that govern dominance between competing extrinsic grouping factors. This procedure allowed us to obtain an unbiased measure of the competition between common region and connectedness cues acting within the same display. The results corroborate previous data showing that grouping by common region dominated the perceived organization of the display, even though the phenomenological strength of the grouping cues was equated for each participant by means of a preliminary scaling task. Our results highlight the relevance of using indirect tasks as an essential tool for the systematic study of the integration of extrinsic grouping cues.

  10. An Agent-Based Simulation for Investigating the Impact of Stereotypes on Task-Oriented Group Formation

    NASA Astrophysics Data System (ADS)

    Maghami, Mahsa; Sukthankar, Gita

    In this paper, we introduce an agent-based simulation for investigating the impact of social factors on the formation and evolution of task-oriented groups. Task-oriented groups are created explicitly to perform a task, and all members derive benefits from task completion. However, even in cases when all group members act in a way that is locally optimal for task completion, social forces that have mild effects on choice of associates can have a measurable impact on task completion performance. In this paper, we show how our simulation can be used to model the impact of stereotypes on group formation. In our simulation, stereotypes are based on observable features, learned from prior experience, and only affect an agent's link formation preferences. Even without assuming stereotypes affect the agents' willingness or ability to complete tasks, the long-term modifications that stereotypes have on the agents' social network impair the agents' ability to form groups with sufficient diversity of skills, as compared to agents who form links randomly. An interesting finding is that this effect holds even in cases where stereotype preference and skill existence are completely uncorrelated.

  11. Comparing Pair and Small Group Interactions on Oral Tasks

    ERIC Educational Resources Information Center

    Lasito,; Storch, Neomy

    2013-01-01

    Although pair and small group activities are commonly used in second language (L2) classrooms, there are very few studies which can inform teachers about whether it is best to have students work in pairs or in small groups. In this study, conducted in a junior high school in Indonesia with learners of English as a Foreign Language (EFL), we…

  12. Anxiety, inhibition, efficiency, and effectiveness. An investigation using antisaccade task.

    PubMed

    Derakshan, Nazanin; Ansari, Tahereh L; Hansard, Miles; Shoker, Leor; Eysenck, Michael W

    2009-01-01

    Effects of anxiety on the antisaccade task were assessed. Performance effectiveness on this task (indexed by error rate) reflects a conflict between volitional and reflexive responses resolved by inhibitory processes (Hutton, S. B., & Ettinger, U. (2006). The antisaccade task as a research tool in psychopathology: A critical review. Psychophysiology, 43, 302-313). However, latency of the first correct saccade reflects processing efficiency (relationship between performance effectiveness and use of resources). In two experiments, high-anxious participants had longer correct antisaccade latencies than low-anxious participants and this effect was greater with threatening cues than positive or neutral ones. The high- and low-anxious groups did not differ in terms of error rate in the antisaccade task. No group differences were found in terms of latency or error rate in the prosaccade task. These results indicate that anxiety affects performance efficiency but not performance effectiveness. The findings are interpreted within the context of attentional control theory (Eysenck, M. W., Derakshan, N., Santos, R., & Calvo, M. G. (2007). Anxiety and cognitive performance: Attentional control theory. Emotion, 7 (2), 336-353).

  13. The Effect of a Workload-Preview on Task-Prioritization and Task-Performance

    ERIC Educational Resources Information Center

    Minotra, Dev

    2012-01-01

    With increased volume and sophistication of cyber attacks in recent years, maintaining situation awareness and effective task-prioritization strategy is critical to the task of cybersecurity analysts. However, high levels of mental-workload associated with the task of cybersecurity analyst's limits their ability to prioritize tasks.…

  14. How to Correct a Task Error: Task-Switch Effects Following Different Types of Error Correction

    ERIC Educational Resources Information Center

    Steinhauser, Marco

    2010-01-01

    It has been proposed that switch costs in task switching reflect the strengthening of task-related associations and that strengthening is triggered by response execution. The present study tested the hypothesis that only task-related responses are able to trigger strengthening. Effects of task strengthening caused by error corrections were…

  15. Group Projects: Student Perceptions of the Relationship between Social Tasks and a Sense of Community in Online Group Work

    ERIC Educational Resources Information Center

    Cameron, Bruce A.; Morgan, Kari; Williams, Karen C.; Kostelecky, Kyle L.

    2009-01-01

    This study explored the relationship between specific social tasks and student perceptions of a sense of community during online group work. A survey instrument was developed, piloted, and deployed to 125 students in six different online classes. Results revealed few significant relationships between each of the five social tasks examined and…

  16. [Social participation processes, task-oriented participation and learning as antecedents of group cohesion. A longitudinal perspective].

    PubMed

    Picazo Lahiguera, Carmen; Zornoza Abad, Ana; Peiró Silla, José M

    2009-05-01

    The aim of this paper is to analyze the effect of changes in social participation and task- and learning-oriented processes on the development of cohesion (social and task-focused) in new groups. Cohesion has been considered one of the most important constructs in small groups, and its influence on team performance and efficacy has been highlighted. However, there are few papers that analyze the processes and the variables that precede the construct and that affect its evolution. Results of the longitudinal study show the importance of changes in participation processes on the development of task cohesion and social cohesion.

  17. The BOLD Response during Stroop Task-Like Inhibition Paradigms: Effects of Task Difficulty and Task-Relevant Modality

    ERIC Educational Resources Information Center

    Mitchell, Rachel L. C.

    2005-01-01

    Previous studies of the Stroop task propose two key mediators: the prefrontal and cingulate cortices but hints exist of functional specialization within these regions. This study aimed to examine the effect of task modality upon the prefrontal and cingulate response by examining the response to colour, number, and shape Stroop tasks whilst BOLD…

  18. Results and conclusions test capabilities task group summary report

    SciTech Connect

    Bomber, T.; Pierce, K.; Easterling, R.; Rogers, J.

    1996-12-01

    This annotated briefing documents an economic analysis of Sandia`s system-level test facilities maintained and operated by the Design, Evaluation, and Test Technology Center 9700. The study was divided into four primary sub-tasks: (1) Estimation of the future system-level test workload, (2) Development of a consistent economic model to estimate the cost of maintaining and operating the test facilities, (3) Determination of the availability of viable alternative test sites, and (4) Assessment of the potential savings through reduction of excess capacity under various facility-closure scenarios. The analysis indicated that potential savings from closing all facilities could approach $6 million per year. However, large uncertainties in these savings remove any sound economic arguments for such closure: it is possible that testing at alternative sites could cost more than maintaining the current set of system-level test facilities. Finally, a number of programmatic risks incurred by facility closure were identified. Consideration of facility closure requires a careful weighing of any projected economic benefit against these programmatic risks. This summary report covers the briefing given to upper management. A more detailed discussion of the data and analyses is given in the full report, available for internal use from the technical library.

  19. Group Life in America: A Task Force Report.

    ERIC Educational Resources Information Center

    Lipset, Seymour Martin

    Contents of this book include discussions of the following topics: (1) issues for the 1970s (redefining American pluralism); (2) historic pattern of change (rise and fall of repressive movements); (3) unity in the post-war era; (4) breakdown in consensus (racial equality and black militancy; demand for group rights; anti-war and other protests;…

  20. The GROOP Effect: Groups Mimic Group Actions

    ERIC Educational Resources Information Center

    Tsai, Jessica Chia-Chin; Sebanz, Natalie; Knoblich, Gunther

    2011-01-01

    Research on perception-action links has focused on an interpersonal level, demonstrating effects of observing individual actions on performance. The present study investigated perception-action matching at an inter-group level. Pairs of participants responded to hand movements that were performed by two individuals who used one hand each or they…

  1. Task coordination between and within sensory modalities: effects on distraction.

    PubMed

    Brand-D'Abrescia, Muriele; Lavie, Nilli

    2008-04-01

    Load theory predictions for the effects of task coordination between and within sensory modalities (vision and hearing or vision only) on the level of distraction were tested. Response competition effects in a visual flanker task when it was coordinated with an auditory discrimination task (between-modality conditions) or a visual discrimination task (within-modality conditions) were compared with single-task conditions. In the between-modality conditions, response competition effects were greater in the two- (vs. single-) task conditions irrespective of the level of discrimination task difficulty. In the within-modality conditions, response competition effects were greater in the two-task (vs. single-task) conditions only when these involved a more difficult visual discrimination task. The results provided support for the load theory prediction that executive control load leads to greater distractor interference while highlighting the effects of task modality.

  2. When sad groups expect to meet again: interactive affective sharing and future interaction expectation as determinants of work groups' analytical and creative task performance.

    PubMed

    Klep, Annefloor H M; Wisse, Barbara; van der Flier, Henk

    2013-12-01

    The present study examines the moderating role of future interaction expectation in the relationship between affective sharing and work groups' task performance. We argue that group affect, a group defining characteristic, becomes more salient to its members when it is interactively shared, and that the anticipation of future interaction may strengthen the effects of group defining characteristics on subsequent group member behaviour. As a consequence, interactive sharing (vs. non-interactive sharing) of negative affect is more likely to influence work group outcomes when group members expect to meet again. Results from a laboratory experiment with 66 three-person work groups indeed show that interactively shared (vs. non-interactively shared) negative affect facilitated work groups' analytical task performance, whereas it inhibited performance on a creative fluency task when groups have expectations of future interaction and not when they do not have such expectations. The discussion focuses on how these results add to theory on group affect and contribute to insights in the effects of future interaction expectation.

  3. Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

    PubMed Central

    Ghai, Shashank; Ghai, Ishan; Effenberg, Alfred O

    2017-01-01

    The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review’s inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16–2.10) and in patients suffering from chronic stroke (−0.22 to 0.86). The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (−0.74 to 0.05). The review also discusses the significance of verbalization in a dual-task setting for increasing cognitive–motor interference. Clinical implications are discussed with respect to practical applications in rehabilitation settings. PMID:28356727

  4. Global oral health inequalities: task group--periodontal disease.

    PubMed

    Jin, L J; Armitage, G C; Klinge, B; Lang, N P; Tonetti, M; Williams, R C

    2011-05-01

    Periodontal diseases constitute one of the major global oral health burdens, and periodontitis remains a major cause of tooth loss in adults worldwide. The World Health Organization recently reported that severe periodontitis exists in 5-20% of adult populations, and most children and adolescents exhibit signs of gingivitis. Likely reasons to account for these prevalent diseases include genetic, epigenetic, and environmental risk factors, as well as individual and socio-economic determinants. Currently, there are fundamental gaps in knowledge of such fundamental issues as the mechanisms of initiation and progression of periodontal diseases, which are undefined; inability to identify high-risk forms of gingivitis that progress to periodontitis; lack of evidence on how to prevent the diseases effectively; inability to detect disease activity and predict treatment efficacy; and limited information on the effects of integration of periodontal health as a part of the health care program designed to promote general health and prevent chronic diseases. In the present report, 12 basic, translational, and applied research areas have been proposed to address the issue of global periodontal health inequality. We believe that the oral health burden caused by periodontal diseases could be relieved significantly in the near future through an effective global collaboration.

  5. Students Successfully Grapple with Lessons of History in Innovative Group Performance Tasks.

    ERIC Educational Resources Information Center

    Bartlett, Lynn Drew

    1992-01-01

    Describes the California Assessment Program's (CAP) group performance assessment task. Provides a sample task field test in world history, including written and culminating exercises. Suggests that such assessment exercises are popular with students and provide the teacher with an amalgam of curriculum, instruction, and assessment. (DK)

  6. The modality effect of ego depletion: Auditory task modality reduces ego depletion.

    PubMed

    Li, Qiong; Wang, Zhenhong

    2016-08-01

    An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion.

  7. The Effect of Focus on Form and Task Complexity on L2 Learners' Oral Task Performance

    ERIC Educational Resources Information Center

    Salimi, Asghar

    2015-01-01

    Second Language learners' oral task performance has been one of interesting and research generating areas of investigations in the field of second language acquisition specially, task-based language teaching and learning. The main purpose of the present study is to investigate the effect of focus on form and task complexity on L2 learners' oral…

  8. Getting behind the Scenes of Fleetwood Mac's "Rumours": Using a Documentary on the Making of a Music Album to Learn about Task Groups

    ERIC Educational Resources Information Center

    Comer, Debra R.; Holbrook, Robert L., Jr.

    2012-01-01

    The authors present an efficient and easy-to-implement experiential exercise that reinforces for students key concepts about task groups (i.e., group cohesiveness, conflict within groups, group effectiveness, group norms, and group roles). The exercise, which uses a documentary about the making of Fleetwood Mac's "Rumours" album to demonstrate the…

  9. Positioning during Group Work on a Novel Task in Algebra II

    ERIC Educational Resources Information Center

    DeJarnette, Anna F.; González, Gloriana

    2015-01-01

    Given the prominence of group work in mathematics education policy and curricular materials, it is important to understand how students make sense of mathematics during group work. We applied techniques from Systemic Functional Linguistics to examine how students positioned themselves during group work on a novel task in Algebra II classes. We…

  10. Fit for the frontline? A focus group exploration of auditory tasks carried out by infantry and combat support personnel.

    PubMed

    Bevis, Zoe L; Semeraro, Hannah D; van Besouw, Rachel M; Rowan, Daniel; Lineton, Ben; Allsopp, Adrian J

    2014-01-01

    In order to preserve their operational effectiveness and ultimately their survival, military personnel must be able to detect important acoustic signals and maintain situational awareness. The possession of sufficient hearing ability to perform job-specific auditory tasks is defined as auditory fitness for duty (AFFD). Pure tone audiometry (PTA) is used to assess AFFD in the UK military; however, it is unclear whether PTA is able to accurately predict performance on job-specific auditory tasks. The aim of the current study was to gather information about auditory tasks carried out by infantry personnel on the frontline and the environment these tasks are performed in. The study consisted of 16 focus group interviews with an average of five participants per group. Eighty British army personnel were recruited from five infantry regiments. The focus group guideline included seven open-ended questions designed to elicit information about the auditory tasks performed on operational duty. Content analysis of the data resulted in two main themes: (1) the auditory tasks personnel are expected to perform and (2) situations where personnel felt their hearing ability was reduced. Auditory tasks were divided into subthemes of sound detection, speech communication and sound localization. Reasons for reduced performance included background noise, hearing protection and attention difficulties. The current study provided an important and novel insight to the complex auditory environment experienced by British infantry personnel and identified 17 auditory tasks carried out by personnel on operational duties. These auditory tasks will be used to inform the development of a functional AFFD test for infantry personnel.

  11. TU-EF-210-04: AAPM Task Groups in Interventional Ultrasound Imaging and Therapy

    SciTech Connect

    Farahani, K.

    2015-06-15

    The use of therapeutic ultrasound to provide targeted therapy is an active research area that has a broad application scope. The invited talks in this session will address currently implemented strategies and protocols for both hyperthermia and ablation applications using therapeutic ultrasound. The role of both ultrasound and MRI in the monitoring and assessment of these therapies will be explored in both pre-clinical and clinical applications. Katherine Ferrara: High Intensity Focused Ultrasound, Drug Delivery, and Immunotherapy Rajiv Chopra: Translating Localized Doxorubicin Delivery to Pediatric Oncology using MRI-guided HIFU Elisa Konofagou: Real-time Ablation Monitoring and Lesion Quantification using Harmonic Motion Imaging Keyvan Farahani: AAPM Task Groups in Interventional Ultrasound Imaging and Therapy Learning Objectives: Understand the role of ultrasound in localized drug delivery and the effects of immunotherapy when used in conjunction with ultrasound therapy. Understand potential targeted drug delivery clinical applications including pediatric oncology. Understand the technical requirements for performing targeted drug delivery. Understand how radiation-force approaches can be used to both monitor and assess high intensity focused ultrasound ablation therapy. Understand the role of AAPM task groups in ultrasound imaging and therapies. Chopra: Funding from Cancer Prevention and Research Initiative of Texas (CPRIT), Award R1308 Evelyn and M.R. Hudson Foundation; Research Support from Research Contract with Philips Healthcare; COI are Co-founder of FUS Instruments Inc Ferrara: Supported by NIH, UCDavis and California (CIRM and BHCE) Farahani: In-kind research support from Philips Healthcare.

  12. Mindfulness training improves attentional task performance in incarcerated youth: a group randomized controlled intervention trial

    PubMed Central

    Leonard, Noelle R.; Jha, Amishi P.; Casarjian, Bethany; Goolsarran, Merissa; Garcia, Cristina; Cleland, Charles M.; Gwadz, Marya V.; Massey, Zohar

    2013-01-01

    We investigated the impact of cognitive behavioral therapy and mindfulness training (CBT/MT) on attentional task performance in incarcerated adolescents. Attention is a cognitive system necessary for managing cognitive demands and regulating emotions. Yet persistent and intensive demands, such as those experienced during high-stress intervals like incarceration and the events leading to incarceration, may deplete attention resulting in cognitive failures, emotional disturbances, and impulsive behavior. We hypothesized that CBT/MT may mitigate these deleterious effects of high stress and protect against degradation in attention over the high-stress interval of incarceration. Using a quasi-experimental, group randomized controlled trial design, we randomly assigned dormitories of incarcerated youth, ages 16–18, to a CBT/MT intervention (youth n = 147) or an active control intervention (youth n = 117). Both arms received approximately 750 min of intervention in a small-group setting over a 3–5 week period. Youth in the CBT/MT arm also logged the amount of out-of-session time spent practicing MT exercises. The Attention Network Test was used to index attentional task performance at baseline and 4 months post-baseline. Overall, task performance degraded over time in all participants. The magnitude of performance degradation was significantly less in the CBT/MT vs. control arm. Further, within the CBT/MT arm, performance degraded over time in those with no outside-of-class practice time, but remained stable over time in those who practiced mindfulness exercises outside of the session meetings. Thus, these findings suggest that sufficient CBT/MT practice may protect against functional attentional impairments associated with high-stress intervals. PMID:24265621

  13. A psychotherapeutic approach to task-oriented groups of severely ill patients.

    PubMed Central

    Wilson, W. H.; Diamond, R. J.; Factor, R. M.

    1985-01-01

    This paper presents a conceptual approach for leading various types of groups of chronically mentally ill patients. Although these groups may have a concrete, task-oriented purpose, with skillful leadership they also function as psychotherapy groups. The developmental deficits in ego functions, object relations, and social skills that severely impair such groups can be compensated by non-interpretative actions of the therapists. The group leader must actively work to provide for the structure, stability, and safety of the group when group members are unable to provide these for themselves. PMID:4049917

  14. The Effects of Material and Task Variations on a Brief Cognitive Learning Strategies Training Program.

    ERIC Educational Resources Information Center

    Weinstein, Claire E.; And Others

    Two studies were performed to investigate the effects of material and task variations in the acquisition of cognitive learning strategies. Groups of undergraduate students were taught to use mental imagery, meaningful elaboration, and grouping. The type of training task or the order of training and test materials differed for each of the…

  15. Vocabulary Learning in Collaborative Tasks: A Comparison of Pair and Small Group Work

    ERIC Educational Resources Information Center

    Dobao, Ana Fernández

    2014-01-01

    This study examined the opportunities that pair and small group interaction offer for collaborative dialogue and second language (L2) vocabulary learning. It compared the performance of the same collaborative writing task by learners working in groups of four (n = 60) and in pairs (n = 50), focusing on the occurrence of lexical language-related…

  16. Indeterminate and Sequential Goal Structures in Relation to Task Performance in Small Groups.

    ERIC Educational Resources Information Center

    Brownell, Celia A.; Hartup, Willard W.

    In this investigation of group problem solving in small groups, performance on a tower-building task was studied in same-sex triads of 141 third grade children exposed to four instructional conditions, each consisting of three phases of six trials each. Instructional conditions were either determinate (i.e., individualistic or contrient reward…

  17. MANAGING UNCERTAINTIES ASSOCIATED WITH RADIOACTIVE WASTE DISPOSAL: TASK GROUP 4 OF THE IAEA PRISM PROJECT

    SciTech Connect

    Seitz, R.

    2011-03-02

    It is widely recognized that the results of safety assessment calculations provide an important contribution to the safety arguments for a disposal facility, but cannot in themselves adequately demonstrate the safety of the disposal system. The safety assessment and a broader range of arguments and activities need to be considered holistically to justify radioactive waste disposal at any particular site. Many programs are therefore moving towards the production of what has become known as a Safety Case, which includes all of the different activities that are conducted to demonstrate the safety of a disposal concept. Recognizing the growing interest in the concept of a Safety Case, the International Atomic Energy Agency (IAEA) is undertaking an intercomparison and harmonization project called PRISM (Practical Illustration and use of the Safety Case Concept in the Management of Near-surface Disposal). The PRISM project is organized into four Task Groups that address key aspects of the Safety Case concept: Task Group 1 - Understanding the Safety Case; Task Group 2 - Disposal facility design; Task Group 3 - Managing waste acceptance; and Task Group 4 - Managing uncertainty. This paper addresses the work of Task Group 4, which is investigating approaches for managing the uncertainties associated with near-surface disposal of radioactive waste and their consideration in the context of the Safety Case. Emphasis is placed on identifying a wide variety of approaches that can and have been used to manage different types of uncertainties, especially non-quantitative approaches that have not received as much attention in previous IAEA projects. This paper includes discussions of the current results of work on the task on managing uncertainty, including: the different circumstances being considered, the sources/types of uncertainties being addressed and some initial proposals for approaches that can be used to manage different types of uncertainties.

  18. [Effects of task interdependence and communication technologies synchrony on performance in virtual teams].

    PubMed

    Rico, Ramón; Cohen, Susan G; Gil, Francisco

    2006-11-01

    Effects of task interdependence and communication technologies synchrony on performance in virtual teams. Survey results of 197 employees from 41 work groups in a large multinational software firm were used to investigate the effects of within-group task interdependence and the degree of communication synchrony on performance in virtual teams (VTs). The analyses revealed a moderating effect of task interdependence on the relationship between the degree of communications synchrony and performance in VT. We found that superior VTs performance is contingent on the fit between the nature of the task (i.e., task interdependence) and the choice of communications modality. This study complements previous research providing additional evidence of how task-technology interaction affects VTs performance, and extends previous findings obtained with ad-hoc groups in laboratory settings to natural, organizational teams.

  19. Quality assurance for nonradiographic radiotherapy localization and positioning systems: report of Task Group 147.

    PubMed

    Willoughby, Twyla; Lehmann, Joerg; Bencomo, Jose A; Jani, Shirish K; Santanam, Lakshmi; Sethi, Anil; Solberg, Timothy D; Tome, Wolfgang A; Waldron, Timothy J

    2012-04-01

    New technologies continue to be developed to improve the practice of radiation therapy. As several of these technologies have been implemented clinically, the Therapy Committee and the Quality Assurance and Outcomes Improvement Subcommittee of the American Association of Physicists in Medicine commissioned Task Group 147 to review the current nonradiographic technologies used for localization and tracking in radiotherapy. The specific charge of this task group was to make recommendations about the use of nonradiographic methods of localization, specifically; radiofrequency, infrared, laser, and video based patient localization and monitoring systems. The charge of this task group was to review the current use of these technologies and to write quality assurance guidelines for the use of these technologies in the clinical setting. Recommendations include testing of equipment for initial installation as well as ongoing quality assurance. As the equipment included in this task group continues to evolve, both in the type and sophistication of technology and in level of integration with treatment devices, some of the details of how one would conduct such testing will also continue to evolve. This task group, therefore, is focused on providing recommendations on the use of this equipment rather than on the equipment itself, and should be adaptable to each user's situation in helping develop a comprehensive quality assurance program.

  20. Task-independent effects are potential confounders in longitudinal imaging studies of learning in schizophrenia.

    PubMed

    Korostil, Michele; Fatima, Zainab; Kovacevic, Natasha; Menon, Mahesh; McIntosh, Anthony Randal

    2016-01-01

    Learning impairment is a core deficit in schizophrenia that impacts on real-world functioning and yet, elucidating its underlying neural basis remains a challenge. A key issue when interpreting learning-task experiments is that task-independent changes may confound interpretation of task-related signal changes in neuroimaging studies. The nature of these task-independent changes in schizophrenia is unknown. Therefore, we examined task-independent "time effects" in a group of participants with schizophrenia contrasted with healthy participants in a longitudinal fMRI learning-experiment designed to allow for examination of non-specific effects of time. Flanking the learning portions of the experiment with a task-of-no-interest allowed us to extract task-independent BOLD changes. Task-independent effects occurred in both groups, but were more robust in the schizophrenia group. There was a significant interaction effect between group and time in a distributed activity pattern that included inferior and superior temporal regions, frontal areas (left anterior insula and superior medial gyri), and parietal areas (posterior cingulate cortices and precuneus). This pattern showed task-independent linear decrease in BOLD amplitude over the two scanning sessions for the schizophrenia group, but showed either opposite effect or no activity changes for the control group. There was a trend towards a correlation between task-independent effects and the presence of more negative symptoms in the schizophrenia group. The strong interaction between group and time suggests that both the scanning experience as a whole and the transition between task-types evokes a different response in persons with schizophrenia and may confound interpretation of learning-related longitudinal imaging experiments if not explicitly considered.

  1. Effects of cognitive task on gait initiation in Parkinson disease: evidence of motor prioritization?

    PubMed

    Nocera, Joe R; Roemmich, Ryan; Elrod, Jonathan; Altmann, Lori J P; Hass, Chris J

    2013-01-01

    While much is known about the effects of dual tasking on cyclical and continuous motor performance (e.g., locomotion), there is a paucity of information on the effect of dual tasking on the initiation of movement. Therefore, the purpose of this study was to investigate the effect of a concurrent cognitive task on gait initiation in three groups: patients with Parkinson disease, healthy older adults, and healthy young adults. We examined the anticipatory postural adjustment displacements and velocities during single-task gait initiation as well as two dual-task conditions: (1) 0-back + gait initiation and (2) 2-back + gait initiation. The Parkinson disease group exhibited less anticipatory postural adjustment displacement and velocity than their aged-matched healthy peers and young adults during the single- and dual-task gait initiation settings (p < 0.05). Of interest was the finding of no additional effect on anticipatory postural adjustment displacement or velocity of gait initiation during the dual-task conditions in any group, including the Parkinson disease group. More traditionally studied gait/balance dual-task paradigms have demonstrated both motor and cognitive decline. Therefore, our results may suggest a prioritization of more "intentional" movement task (e.g., gait initiation) while dual tasking in Parkinson disease.

  2. Group Work: How to Use Groups Effectively

    ERIC Educational Resources Information Center

    Burke, Alison

    2011-01-01

    Many students cringe and groan when told that they will need to work in a group. However, group work has been found to be good for students and good for teachers. Employers want college graduates to have developed teamwork skills. Additionally, students who participate in collaborative learning get better grades, are more satisfied with their…

  3. Theory of mind tasks and executive functions: a systematic review of group studies in neurology.

    PubMed

    Aboulafia-Brakha, T; Christe, B; Martory, M-D; Annoni, J-M

    2011-03-01

    A growing number of studies have been addressing the relationship between theory of mind (TOM) and executive functions (EF) in patients with acquired neurological pathology. In order to provide a global overview on the main findings, we conducted a systematic review on group studies where we aimed to (1) evaluate the patterns of impaired and preserved abilities of both TOM and EF in groups of patients with acquired neurological pathology and (2) investigate the existence of particular relations between different EF domains and TOM tasks. The search was conducted in Pubmed/Medline. A total of 24 articles met the inclusion criteria. We considered for analysis classical clinically accepted TOM tasks (first- and second-order false belief stories, the Faux Pas test, Happe's stories, the Mind in the Eyes task, and Cartoon's tasks) and EF domains (updating, shifting, inhibition, and access). The review suggests that (1) EF and TOM appear tightly associated. However, the few dissociations observed suggest they cannot be reduced to a single function; (2) no executive subprocess could be specifically associated with TOM performances; (3) the first-order false belief task and the Happe's story task seem to be less sensitive to neurological pathologies and less associated to EF. Even though the analysis of the reviewed studies demonstrates a close relationship between TOM and EF in patients with acquired neurological pathology, the nature of this relationship must be further investigated. Studies investigating ecological consequences of TOM and EF deficits, and intervention researches may bring further contributions to this question.

  4. Effects of Music Loudness on Task Performance and Self-Report of College-Aged Students.

    ERIC Educational Resources Information Center

    Wolfe, David E.

    1983-01-01

    The effects of the loudness of background music on task performance of college students was studied. Results indicated that the experimental conditions had no significant effect on task performance; the majority of students did recognize the music; and students in the 80-90 B group perceived the music as most distracting. (Author/IS)

  5. Task-Dependent Masked Priming Effects in Visual Word Recognition

    PubMed Central

    Kinoshita, Sachiko; Norris, Dennis

    2012-01-01

    A method used widely to study the first 250 ms of visual word recognition is masked priming: These studies have yielded a rich set of data concerning the processes involved in recognizing letters and words. In these studies, there is an implicit assumption that the early processes in word recognition tapped by masked priming are automatic, and masked priming effects should therefore be invariant across tasks. Contrary to this assumption, masked priming effects are modulated by the task goal: For example, only word targets show priming in the lexical decision task, but both words and non-words do in the same-different task; semantic priming effects are generally weak in the lexical decision task but are robust in the semantic categorization task. We explain how such task dependence arises within the Bayesian Reader account of masked priming (Norris and Kinoshita, 2008), and how the task dissociations can be used to understand the early processes in lexical access. PMID:22675316

  6. Gender and Group Composition in Small Task Groups Using Computer-Mediated Communication.

    ERIC Educational Resources Information Center

    Savicki, Victor; And Others

    1996-01-01

    Gender and group composition variables in a computer-mediated communication context are examined. Subjects were 36 undergraduate male and female psychology students. Findings are analyzed in terms of choice of language; participation; satisfaction; and interpersonal conflict. Ten tables present study results. (Author/AEF)

  7. Rotation during lifting tasks: effects of rotation frequency and task order on localized muscle fatigue and performance.

    PubMed

    Horton, Leanna M; Nussbaum, Maury A; Agnew, Michael J

    2015-01-01

    Though widely considered to reduce the risk of work-related musculoskeletal disorders, there is limited evidence suggesting that rotating between tasks is effective in doing so. The purpose of the current study was to quantify the effects of rotation and parameters of rotation (frequency and task order) on muscle fatigue and performance. This was done using a simulated lifting task, with rotation between two levels of loading of the same muscle groups. Twelve participants completed six experimental sessions during which repetitive box lifting was performed for one hour either with or without rotation. When rotation was present, it occurred every 15 minutes or every 30 minutes and was between two load levels (box weights). Rotation reduced fatigue and cardiovascular demand compared to the heavier load without rotation, with a mean reduction of ∼33% in perceived discomfort and a ∼17% reduction in percentage of heart rate reserve. Further, rotation increased fatigue and cardiovascular demand compared to the lighter load without rotation, with a mean increase of ∼34% perceived discomfort and a ∼19% increase in percentage of heart rate reserve. Neither rotation frequency nor task order had definitive effects, though maximum discomfort ratings were nearly 20% higher when starting with the lighter load task. These parameters of rotation should be further evaluated under more realistic task conditions.

  8. Shared learning shapes human performance: Transfer effects in task sharing.

    PubMed

    Milanese, Nadia; Iani, Cristina; Rubichi, Sandro

    2010-07-01

    We investigated whether performing a task with a co-actor shapes the way a subsequent task is performed. In four experiments participants were administered a Simon task after practicing a spatial compatibility task with an incompatible S-R mapping. In Experiment 1 they performed both tasks alongside another person; in Experiment 2 they performed the spatial compatibility task alone, responding to only one stimulus position, and the Simon task with another person; in Experiment 3, they performed the spatial compatibility task with another person and the Simon task alone; finally, in Experiment 4, they performed the spatial compatibility task alone and the Simon task with another person. The incompatible practice eliminated the Simon effect in Experiments 1 and 4. These results indicate that when a task is distributed between two participants with each one performing a different part of it, they tend to represent the whole task rather than their own part of it. This experience can influence the way a subsequent task is performed, as long as this latter occurs in a social context.

  9. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats.

    PubMed

    Hulgard, Katrine; Ratcliffe, John M

    2016-02-09

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach to prey under presumably more difficult conditions. Specifically, we found Daubenton's bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking stationary prey. Buzz duration and sonar sound groups have been suggested to be independent means by which bats attend to would-be targets and other objects of interest. We suggest that for attacking bats both should be considered as indicators of task difficulty and that the buzz is, essentially, an extended sonar sound group.

  10. Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats

    PubMed Central

    Hulgard, Katrine; Ratcliffe, John M.

    2016-01-01

    More difficult tasks are generally regarded as such because they demand greater attention. Echolocators provide rare insight into this relationship because biosonar signals can be monitored. Here we show that bats produce longer terminal buzzes and more sonar sound groups during their approach to prey under presumably more difficult conditions. Specifically, we found Daubenton’s bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking stationary prey. Buzz duration and sonar sound groups have been suggested to be independent means by which bats attend to would-be targets and other objects of interest. We suggest that for attacking bats both should be considered as indicators of task difficulty and that the buzz is, essentially, an extended sonar sound group. PMID:26857019

  11. Learning New Behaviours through Group Adventure Initiative Tasks: A Theoretical Perspective.

    ERIC Educational Resources Information Center

    Kemp, Travis; McCarron, Leonie

    This paper presents a model for implementation of behavior therapies in adventure programs that use Group Adventure Initiative Tasks (GAITs) to promote personal development. Behavior therapies include various techniques and processes based in learning and pedagogical theory and used to promote changes in behavioral responses to environmental…

  12. National facilities study. Volume 2: Task group on aeronautical research and development facilities report

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Task Group on Aeronautics R&D Facilities examined the status and requirements for aeronautics facilities against the competitive need. Emphasis was placed on ground-based facilities for subsonic, supersonic and hypersonic aerodynamics, and propulsion. Subsonic and transonic wind tunnels were judged to be most critical and of highest priority. Results of the study are presented.

  13. Group Adlerian Play Therapy with Children with Off-Task Behaviors

    ERIC Educational Resources Information Center

    Meany-Walen, Kristin K.; Bullis, Quinn; Kottman, Terry; Dillman Taylor, Dalena

    2015-01-01

    Children who are off-task in schools struggle with completing their work and engage in disruptive behaviors. Without intervention, these behaviors tend to worsen, putting them at risk for more serious, ongoing problems throughout life. Group counseling provides opportunities for people to practice socially useful behaviors. Using a single case…

  14. Attention to Form in Collaborative Writing Tasks: Comparing Pair and Small Group Interaction

    ERIC Educational Resources Information Center

    Dobao, Ana Fernández

    2014-01-01

    This study examines the opportunities that a collaborative writing task completed in pairs and in small groups offers for attention to form. Previous research suggests that collaborative writing activities encourage learners to focus their attention on language and to collaborate in the resolution of their language-related problems in ways that…

  15. Astronomy Education. Third Newsletter of the TGEA (Task Group on Education in Astronomy).

    ERIC Educational Resources Information Center

    Wentzel, Donat G., Comp.

    This newsletter, published by the Task Group on Education in Astronomy, focuses on astronomy education both for the public and for schools. Topics in this issue include new publications related to astronomy education; a roster of consultants on astronomy education; a collection of course syllabuses (college level); teaching astronomy in schools,…

  16. Task Groups in the School Setting: Promoting Children's Social and Emotional Learning

    ERIC Educational Resources Information Center

    Van Velsor, Patricia

    2009-01-01

    Through social and emotional learning (SEL), individuals develop skill in negotiating relationships successfully and expressing emotions appropriately. The socially and emotionally intelligent child reaps benefits in school and later life. Counselors are best qualified to promote children's SEL and the task group in the classroom provides an…

  17. 76 FR 26771 - NASA Advisory Council; Task Group of the Science Committee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-09

    ... SPACE ADMINISTRATION NASA Advisory Council; Task Group of the Science Committee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION: Notice of meeting. SUMMARY: In accordance with the Federal Advisory Committee Act, Public Law 92-463, as amended, the National Aeronautics and...

  18. 76 FR 21073 - NASA Advisory Council; Task Group of the Science Committee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-14

    ... SPACE ADMINISTRATION NASA Advisory Council; Task Group of the Science Committee; Meeting AGENCY: National Aeronautics and Space Administration. ACTION: Notice of meeting. SUMMARY: In accordance with the Federal Advisory Committee Act, Public Law 92-463, as amended, the National Aeronautics and...

  19. A Consensus-Based Grouping Algorithm for Multi-agent Cooperative Task Allocation with Complex Requirements.

    PubMed

    Hunt, Simon; Meng, Qinggang; Hinde, Chris; Huang, Tingwen

    2014-01-01

    This paper looks at consensus algorithms for agent cooperation with unmanned aerial vehicles. The foundation is the consensus-based bundle algorithm, which is extended to allow multi-agent tasks requiring agents to cooperate in completing individual tasks. Inspiration is taken from the cognitive behaviours of eusocial animals for cooperation and improved assignments. Using the behaviours observed in bees and ants inspires decentralised algorithms for groups of agents to adapt to changing task demand. Further extensions are provided to improve task complexity handling by the agents with added equipment requirements and task dependencies. We address the problems of handling these challenges and improve the efficiency of the algorithm for these requirements, whilst decreasing the communication cost with a new data structure. The proposed algorithm converges to a conflict-free, feasible solution of which previous algorithms are unable to account for. Furthermore, the algorithm takes into account heterogeneous agents, deadlocking and a method to store assignments for a dynamical environment. Simulation results demonstrate reduced data usage and communication time to come to a consensus on multi-agent tasks.

  20. Task Group on a Culture of Savings: Implementing Behavior Change in DoD

    DTIC Science & Technology

    2011-01-01

    Robert Hale Task Group Chairman – Navy Future Personnel and Pay Solution (FPPS) - Business Case November 30, 2009 – Case for Shared Services in the...Public Sector - Accenture Shared Services in Government - AT Kearney – 2009 Global Shared Services Survey Results - Deloitte – Shared Services - a...Benchmark Study - The Johnson Group – Economics of Business Process Outsourcing - Technology Association of Georgia – State of Shared Services and Business

  1. Remember to do: insomnia versus control groups in a prospective memory task.

    PubMed

    Fabbri, Marco; Tonetti, Lorenzo; Martoni, Monica; Natale, Vincenzo

    2015-01-01

    Primary insomnia is characterized by difficulty in falling asleep and/or remaining asleep, by early morning awakening and/or nonrestorative sleep, and resultant daytime dysfunction in the absence of specific physical, mental, or substance-related causes. However, the studies on daytime cognitive functioning of insomnia patients report inconclusive results. This retrospective study aimed to compare the performance of insomnia patients (N = 54) to that of controls (N = 113) in a naturalistic prospective memory task. Task performance was defined by the percentage of times the event-marker button of an actigraph was pressed, at lights-off time and at wake-up time. The performance pattern in the prospective memory task was similar in both groups. In addition, the task was performed better at lights-off time than at wake-up time regardless of group. Post-hoc subgroup analysis showed that there were more insomnia patients who performed the task perfectly (i.e., 100%) than controls. Performance at wake-up time was significantly correlated to objective sleep quality (i.e., sleep efficiency) only in insomnia patients.

  2. Interactional Concerns in Implementing Group Tasks: Addressing Silence, Dominance, and Off-Task Talk in an Academic Writing Class

    ERIC Educational Resources Information Center

    Sharma, Bal Krishna

    2015-01-01

    This study investigates the teacher role in mediating the task and the learner in an advanced academic writing class. Having identified three verbal (non-)participation patterns of students in collaborative tasks (silence, dominance, and off-task talk), I examine how these interactional concerns are understood and addressed by English as a second…

  3. New indirect measures of "inattentive" visual grouping in a change-detection task.

    PubMed

    Russell, Charlotte; Driver, Jon

    2005-05-01

    It has often been suggested that Gestalt-like visual grouping processes may operate preattentively, but Mack and Rock (1998) suggested that no visual grouping takes place under "inattention." We introduced a new method to assess this. While participants performed a demanding change-detection task on a small matrix at fixation, task-irrelevant background elements were arranged by color sinilarity into columns, rows, or pseudorandomly. Independent of any change in the target matrix, background grouping could also change or remain the same on each trial. This influenced accuracy of change judgments for the central task, even though background grouping or its change usually could not be explicitly reported when probed with surprise questions as in Mack and Rock. This suggests that visual grouping may arise implicitly under inattention and provides a new method for testing the boundaries of this processing. Here we extended the initial result to changes in background grouping remote from the target and to those occurring across an intervening saccade.

  4. Locus of backward crosstalk effects on task 1 in a psychological refractory period task.

    PubMed

    Ko, Yao-Ting; Miller, Jeff

    2014-01-01

    Our performance on a task decreases when the task is in a dual-task situation than when it is in isolation. An important experimental setting for dual-task situation is the psychological refractory period (PRP) paradigm, and the dual-task performance decrements in the PRP paradigm are referred to as PRP interference. The standard response-selection bottleneck (RSB) models state that the response-selection stage of the second task (T2) cannot start until the response-selection stage of the first task (T1) finishes, resulting in the PRP interference. Contrary to the prediction of RSB models, several researchers have found T2's modulations on T1's performance, and have suggested that T1's selection-related processes are affected by T2's selection-related processes, referred to as backward crosstalk effects. The locus of backward crosstalk effects is not clear, however, because RTs were measured in most previous studies. By using semantically unrelated stimuli and responses and by measuring T1's lateralized readiness potential, we examined the locus of backward crosstalk effects. We found that the interval between T1's stimulus onset and the stimulus-locked LRP onset was affected, suggesting T2's response selection starts before T1's selection is complete. The present result provided electrophysiological evidence focusing on T1's changes in favor of the hypothesis of parallel response selection in the PRP paradigm.

  5. Role of Gestalt grouping in selective attention: evidence from the Stroop task.

    PubMed

    Lamers, Martijn J M; Roelofs, Ardi

    2007-11-01

    Selective attention has been intensively studied using the Stroop task. Evidence suggests that Stroop interference in a color-naming task arises partly because of visual attention sharing between color and word: Removing the target color after 150 msec reduces interference (Neumann, 1986). Moreover, removing both the color and the word simultaneously reduces interference less than does removing the color only (La Heij, van der Heijden, & Plooij, 2001). These findings could also be attributed to Gestalt grouping principles, such as common fate. We report three experiments in which the role of Gestalt grouping was further investigated. Experiment I replicated the reduced interference, using words and color patches. In Experiment 2, the color patch was not removed but only repositioned (<2 degrees) after 100 msec, which also reduced interference. In Experiment 3, the distractor was repositioned while the target remained stationary, again reducing interference. These results indicate a role for Gestalt grouping in selective attention.

  6. Schema vs. primitive perceptual grouping: the relative weighting of sequential vs. spatial cues during an auditory grouping task in frogs.

    PubMed

    Farris, Hamilton E; Ryan, Michael J

    2017-02-15

    Perceptually, grouping sounds based on their sources is critical for communication. This is especially true in túngara frog breeding aggregations, where multiple males produce overlapping calls that consist of an FM 'whine' followed by harmonic bursts called 'chucks'. Phonotactic females use at least two cues to group whines and chucks: whine-chuck spatial separation and sequence. Spatial separation is a primitive cue, whereas sequence is schema-based, as chuck production is morphologically constrained to follow whines, meaning that males cannot produce the components simultaneously. When one cue is available, females perceptually group whines and chucks using relative comparisons: components with the smallest spatial separation or those closest to the natural sequence are more likely grouped. By simultaneously varying the temporal sequence and spatial separation of a single whine and two chucks, this study measured between-cue perceptual weighting during a specific grouping task. Results show that whine-chuck spatial separation is a stronger grouping cue than temporal sequence, as grouping is more likely for stimuli with smaller spatial separation and non-natural sequence than those with larger spatial separation and natural sequence. Compared to the schema-based whine-chuck sequence, we propose that spatial cues have less variance, potentially explaining their preferred use when grouping during directional behavioral responses.

  7. The Effect of Group Projects on Content-Related Learning

    ERIC Educational Resources Information Center

    Bacon, Donald R.

    2005-01-01

    Business schools often assign student group projects to enhance student learning of course content and to build teamwork skills. However, the characteristics of effective collaborative learning tasks, including group goals and individual accountability, are often not found in student group projects assigned in business classes. The current…

  8. The Effects of Biofeedback and Relaxation Training on Memory Tasks among Hyperactive Boys.

    ERIC Educational Resources Information Center

    Omizo, Michael M.; And Others

    1986-01-01

    A study examined the effects of biofeedback and relaxation training on memory tasks among 48 hyperactive boys (9-11 years old). Relaxation training in combination with biofeedback was useful in helping the boys achieve better muscle relaxation and perform better on a paired-associate memory task than did a control group. (Author/CB)

  9. The working group ``Science with the SRT'': tasks, activities, and results

    NASA Astrophysics Data System (ADS)

    Prandoni, I.; Felli, M.

    The Working Group Science with the SRT was formed in May 2004, with the aim of providing scientific input to the Board of the SRT, in order to plan the focal plane instrumentation development of the SRT. In the present contribution, tasks and activities of the Working Group are outlined, and the main indications and results are briefly summarized. For a detailed discussion we refer to the IRA Internal Report ``The Sardinia Radio Telescope (SRT). Science and Technical Requirements'' produced by the members of the Working Group.

  10. What would you do? The effect of verbal persuasion on task choice.

    PubMed

    Lamarche, Larkin; Gionfriddo, Alicia M; Cline, Lindsay E; Gammage, Kimberley L; Adkin, Allan L

    2014-01-01

    Verbal persuasion has been shown to influence psychological and behavioral outcomes. The present study had two objectives: (1) to examine the effect of verbal persuasion on task choice in a balance setting and (2) to evaluate the use of verbal persuasion as an approach to experimentally induce mismatches between perceived and actual balance. Healthy young adults (N=68) completed an 8-m tandem walk task without vision and then were randomly assigned to a feedback group (good, control, or poor), regardless of actual balance. Following the feedback, participants chose to perform the task in one of three conditions differing in level of challenge and also were required to perform the task under the same pre-feedback conditions. Balance efficacy and perceived stability were rated before and after each pre- and post-feedback task, respectively. Balance performance measures were also collected. Following the feedback, participants in the good group were more likely to choose the most challenging task while those in the poor group were more likely to choose the least challenging task. Following the feedback, all groups showed improved balance performance. However, balance efficacy and perceived stability increased for the good and control groups but balance efficacy decreased and perceived stability was unchanged for the poor group. Thus, these findings demonstrate that verbal persuasion can influence task choice and may be used as an approach to experimentally create mismatches between perceived and actual balance.

  11. Instruction-based task-rule congruency effects.

    PubMed

    Liefooghe, Baptist; Wenke, Dorit; De Houwer, Jan

    2012-09-01

    In the present study, we investigated the functional characteristics of task sets that were never applied before and were formed only on the basis of instructions. We tested if such task sets could elicit a task-rule congruency effect, which implies the automatic activation of responses in the context of another task. To this end, a novel procedure was developed that revealed instruction-based task-rule congruency effects in 2 experiments. Although the effect seems quite general (Experiment 1), it still necessitates the formation of a task set, as it cannot be induced by the mere maintenance of instructions in declarative working memory (Experiment 2). We conclude that a task set representing only key features of an upcoming task can be formed on the basis of instructions alone to such a degree that it can automatically trigger a response tendency in another task. Implications of our results for the impact of instructions on performance in general and for the occurrence of task-rule congruency effects in particular are discussed.

  12. Coaction Effects on a Muscular Endurance Task

    ERIC Educational Resources Information Center

    Martens, Rainer; Landers, Daniel M.

    1969-01-01

    A common procedure in administering muscular endurance tests is to have several individuals perform the same task at the same time. A very old psychological concept known as social facilitation suggests that an individual's performance may be affected by the presence of others. (CK)

  13. Task Effects in the Interpretation of Pronouns

    ERIC Educational Resources Information Center

    Sanoudaki, Eirini; Varlokosta, Spyridoula

    2015-01-01

    Children acquiring a range of languages have difficulties in the interpretation of personal pronouns. Ongoing debates in the relevant literature concern the extent to which different pronoun types are subject to this phenomenon, as well as the role of methodology in relevant research. In this study, we use two different experimental tasks to…

  14. Towards mainstreaming of biodiversity data publishing: recommendations of the GBIF Data Publishing Framework Task Group

    PubMed Central

    2011-01-01

    can address sociocultural, technical-infrastructural, policy, political and legal constraints, as well as addressing issues of sustainability and financial support. To address these aspects of a data publishing framework - a systematic, standard approach to the formal definition and public disclosure of data - in the context of biodiversity data, the Global Biodiversity Information Facility (GBIF, the single inter-governmental body most clearly mandated to undertake such an effort) convened a Data Publishing Framework Task Group. We conceive this data publishing framework as an environment conducive to ensure free and open access to world's biodiversity data. Here, we present the recommendations of that Task Group, which are intended to encourage free and open access to the worlds' biodiversity data. PMID:22373150

  15. Word Effects in Dual-Task Studies Using Lexical Decision and Naming as Task 2

    NASA Technical Reports Server (NTRS)

    Remington, Roger; McCann, Robert S.; VanSelst, Mark; Shafto, Michael (Technical Monitor)

    1997-01-01

    Word frequency effects in dual-task, lexical decision are variously reported to be additive or under-additive across SOA. We replicate and extend earlier lexical decision studies and find word frequency to be additive across SOA. To more directly capture lexical processing, we examine dual-task naming. Once again we find word frequency to be additive across SOA. Lexical processing appears to be constrained by central processing limitations.

  16. Word Frequency Effects in Dual-Task Studies Using Lexical Decision and Naming as Task 2

    NASA Technical Reports Server (NTRS)

    Remington, Roger W.; McCann, Robert S.; VanSelst, Mark; Shafto, Michael G. (Technical Monitor)

    1997-01-01

    Word frequency effects in dual-task lexical decision are variously reported to be additive or underadditive across SOA. We replicate and extend earlier lexical decision studies and find word frequency to be additive across SOA. To more directly capture lexical processing, we examine dual-task naming. Once again, we find word frequency to be additive across SOA. Lexical processing appears to be constrained by central processing limitations.

  17. NASA Battery Working Group - 2007-2008: Battery Task Summary Report

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle

    2008-01-01

    This presentation provides a summary of the 2007-2008 NASA Battery Working Group efforts completed in support of the NASA Engineering Safety Center (NESC). The effort covered a series of pro-active tasks that address the following: Binding Procurements -- guidelines related to requirements for the battery system that should be considered at the time of contract award Wet Life of Ni-H2 Batteries -- issues/strategies for effective storage and impact of long-term storage on performance and life Generic Guidelines for Lithium-ion Safety, Handling and Qualification -- Standardized approaches developed and risk assessments (1) Lithium-ion Performance Assessment -- survey of manufacturers and capabilities to meet mission needs. Guidelines document generated (2) Conditions Required for using Pouch Cells in Aerospace Missions -- focus on corrosion, thermal excursions and long-term performance issues. Document defining requirements to maintain performance and life (3) High Voltage Risk Assessment -- focus on safety and abuse tolerance of battery module assemblies. Recommendations of features required for safe implementation (4) Procedure for Determination of Safe Charge Rates -- evaluation of various cell chemistries and recommendation of safe operating regimes for specific cell designs

  18. Therapeutic effects of an imposed foraging task in disturbed monkeys.

    PubMed

    Rosenblum, L A; Smiley, J

    1984-07-01

    A group of twelve bonnet macaques (Macaca radiata) raised in partial social isolation from birth to adulthood expressed moderate-to-severe behavioral disturbance as a function of their early rearing environments. The range of these behavioral function of their early rearing environments. The range of these behavioral abnormalities in this species are described for the first time. In order to assess the role of the current environment on their behavior, the animals as a group were required to obtain all of their food from a foraging device presenting two levels of difficulty. The therapeutic effect of the imposed foraging task was dependent upon the individual's status in the dominance hierarchy. Low- and high-ranking animals responded positively and became more social (338% above baseline levels) and showed lower levels of specific abnormal behaviors (nearly 75% lower). Mid-ranking animals responded negatively and became less social (89% lower), while their levels of abnormal behavior dramatically increased (200% higher).

  19. OPERATION CASTLE. The Operation Plan Number 1-53. Task Group 7.1

    DTIC Science & Technology

    1984-08-31

    installs converters. (8) Procures spare JouleThcmpson Heat Exchanger for emergency use, (9) Coordinates witk. TU-3 in filling the Cambridge Corporation ...LASL, establishes the facilities reqaired by Cambridge Corporation for ths operation at the Forward Area. [0 (3) Makes arrangements witý J-4 for...Rescue and Hi-Speed Personnel Carrier YCV 1 Helicopter Platform TASK GROUP 7.5 BOAT POOL AFDL’ 1 2 Tugs Floating Dry Dock YTL 2 Tugs; 1 Wood, 1 Steel

  20. The respiratory tract deposition model proposed by the ICRP Task Group

    SciTech Connect

    James, A.C.; Briant, J.K. ); Stahlhofen, W.; Rudolf, G. . Abt. fuer Biophysikalische Strahlenforschung); Egan, M.J.; Nixon, W. ); Gehr, P. . Anatomisches Inst.)

    1990-11-01

    The Task Group has developed a new model of the deposition of inhaled aerosols in each anatomical region of the respiratory tract. The model is used to evaluate the fraction of airborne activity that is deposited in respiratory regions having distinct retention characteristics and clearance pathways: the anterior nares, the extrathoracic airways of the naso- and oropharynx and larynx, the bronchi, the bronchioles, and the alveolated airways of the lung. Drawn from experimental data on total and regional deposition in human subjects, the model is based on extrapolation of these data by means of a detailed theoretical model of aerosol transport and deposition within the lung. The Task Group model applies to all practical conditions, and for aerosol particles and vapors from atomic size up to very coarse aerosols with an activity median aerodynamic diameter of 100 {mu}m. The model is designed to predict regional deposition in different subjects, including adults of either sex, children of various ages, and infants, and also to account for anatomical differences among Caucasian and non-Caucasian subjects. The Task Group model represents aerosol inhalability and regional deposition in different subjects by algebraic expressions of aerosol size, breathing rates, standard lung volumes, and scaling factors for airway dimensions. 35 refs., 13 figs., 2 tabs.

  1. Are Expert Users Always Better Searchers? Interaction of Expertise and Semantic Grouping in Hypertext Search Tasks

    ERIC Educational Resources Information Center

    Salmeron, L.; Canas, J. J.; Fajardo, I.

    2005-01-01

    The facilitative effect of expertise in hypertext information retrieval (IR) tasks has been widely reported in related literature. However, recent theories of human expertise question the robustness of this result, since previous works have not fully considered the interaction between user and system characteristics. In this study, the constraint…

  2. EFFECT OF ENERGY DRINKS ON SELECTED FINE MOTOR TASKS.

    PubMed

    Jacobson, B H; Hughes, P P; Conchola, E C; Hester, G M; Woolsey, C L

    2015-08-01

    This study assessed the effect of energy shots on selected fine motor tasks. The participants were college-age male (n=19; M age=20.5 yr., SD=0.7) and female (n=21; M age=21.1 yr., SD=0.7) volunteers who were assessed on hand steadiness, choice reaction time, rotary pursuit, and simple reaction time. The energy shots group scored significantly poorer on the hand steadiness tests and significantly better on choice reaction time and simple reaction time tests. The enhanced reaction time and disruption in hand steadiness afforded by energy shots would not be apparent in many gross motor activities, but it is possible that reaction time improvement could be beneficial in sports that require quick, reflexive movements. However, the potential adverse psychological and physiological effects warrant discretionary use of such products.

  3. Effects of stair task training on walking ability in stroke patients

    PubMed Central

    Choi, Yong-Kyu; Kim, Kyoung; Choi, Jin-Uk

    2017-01-01

    [Purpose] The aim of this study was to determine the effect of stair task training on gait abilities by conducting stair task training. In this training, step training is applied in various directions with hemiplegia patients. [Subjects and Methods] Thirty-six patients with stroke were selected on the basis of inclusion and exclusion criteria, and they were randomly divided into eighteen patients in the experimental group and eighteen patients in the control group via draw. [Results] In this study, the Dartfish program was used to measure gait capabilities. Experiment group showed a statistically significant improvement in the swing phase time of the affected lower extremity compared to control group. [Conclusion] It was found that the stair task training group had effective results in the swing phase time of the affected lower extremity compared with the group that applied weight support on the affected lower extremity and balance training. PMID:28265147

  4. SU-E-T-181: Clinical Implementation of Task Group 176

    SciTech Connect

    Burgdorf, B; Yeager, C; Zhou, F; Hand, C

    2015-06-15

    Purpose: The implementation of TG-176 with regards to immobilization devices and couch tops as they effect dosimetric treatment planning. Methods: The external devices used clinically were scanned to measure their HU values. Plans were created in the Eclipse treatment planning system (TPS) using these devices, one that accounted for the correct HU value of the each device and another that did not include the device as a structure. A dose subtraction was performed between the two plans to evaluate the dosimetric differences. The metrics used for evaluation included attenuation and surface dose. Plan parameters were varied to evaluate the impact of the devices in different clinical scenarios. Results: While the exact HU values of our results are clinic-dependent, the protocol being implemented is widely applicable. We recommend a four step process for implementing this task group. First, physics should scan each treatment device to determine accurate HU values. Second, CT therapists should include in the setup note which table top was used during patient CT simulation and are asked to make immobilization devices as uniform in thickness as possible. Therapists should also index the devices whenever possible so beam will traverse the same area of the device. Third, the dosimetrist should manually correct the HU value for any external device, including the couch. For H&N cases, the rails must be removed from the couch structure. When rails are used during treatments, it is important to make note of their exact position in the setup notes. Finally, physicians should be made aware that there could be changes in surface doses depending on whether or not immobilization devices or couch tops are in the beam path. Conclusion: The protocol outlined above was implemented to reduce the errors that arise from ignoring effects of external devices, thus ensuring safer, more accurate patient treatments.

  5. An analysis of confidence limit calculations used in AAPM Task Group No. 119

    SciTech Connect

    Knill, Cory; Snyder, Michael

    2011-04-15

    Purpose: The report issued by AAPM Task Group No. 119 outlined a procedure for evaluating the effectiveness of IMRT commissioning. The procedure involves measuring gamma pass-rate indices for IMRT plans of standard phantoms and determining if the results fall within a confidence limit set by assuming normally distributed data. As stated in the TG report, the assumption of normally distributed gamma pass rates is a convenient approximation for commissioning purposes, but may not accurately describe the data. Here the authors attempt to better describe gamma pass-rate data by fitting it to different distributions. The authors then calculate updated confidence limits using those distributions and compare them to those derived using TG No. 119 method. Methods: Gamma pass-rate data from 111 head and neck patients are fitted using the TG No. 119 normal distribution, a truncated normal distribution, and a Weibull distribution. Confidence limits to 95% are calculated for each and compared. A more general analysis of the expected differences between the TG No. 119 method of determining confidence limits and a more time-consuming curve fitting method is performed. Results: The TG No. 119 standard normal distribution does not fit the measured data. However, due to the small range of measured data points, the inaccuracy of the fit has only a small effect on the final value of the confidence limits. The confidence limits for the 111 patient plans are within 0.1% of each other for all distributions. The maximum expected difference in confidence limits, calculated using TG No. 119's approximation and a truncated distribution, is 1.2%. Conclusions: A three-parameter Weibull probability distribution more accurately fits the clinical gamma index pass-rate data than the normal distribution adopted by TG No. 119. However, the sensitivity of the confidence limit on distribution fit is low outside of exceptional circumstances.

  6. The Effect of Episodic Retrieval on Inhibition in Task Switching.

    PubMed

    Grange, James A; Kowalczyk, Agnieszka W; O'Loughlin, Rory

    2017-04-06

    Inhibition in task switching is inferred from n-2 repetition costs: the observation that ABA task switching sequences are responded to slower than CBA sequences. This is thought to reflect the persisting inhibition of Task A, which slows reactivation attempts. Mayr (2002) reported an experiment testing a critical noninhibitory account of this effect, namely episodic retrieval: If the trial parameters for Task A match across an ABA sequence, responses should be facilitated because of priming from episodic retrieval; a cost would occur if trial parameters mismatch. In a rule-switching paradigm, Mayr reported no significant difference in n-2 repetition cost when the trial parameters repeated or switched across an ABA sequence, in clear contrast to the episodic retrieval account. What remains unclear is whether successful episodic retrieval modulates the n-2 repetition cost. Across 3 experiments-including a close replication of Mayr-we find clear evidence of reduced n-2 task repetition costs when episodic retrieval is controlled. We find that the effect of episodic retrieval on the n-2 task repetition cost is increased when the cue-task relationship is made more abstract, suggesting the effect is because of interference in establishing the relevant attentional set. We also demonstrate that the episodic retrieval effect is not influenced by retrieval of low-level, perceptual, elements. Together, the data suggest the n-2 task repetition cost-typically attributable to an inhibitory mechanism-also reflects episodic retrieval effects. (PsycINFO Database Record

  7. Learning effects in the lane change task (LCT)--realistic secondary tasks and transfer of learning.

    PubMed

    Petzoldt, Tibor; Brüggemann, Stephanie; Krems, Josef F

    2014-05-01

    Driver distraction is a factor that is heavily involved in traffic crashes. With in-vehicle devices like navigation systems or mobile phones on the rise, the assessment of their potential to distract the driver has become a pressing issue. Several easy-to-use methods have been developed in recent years to allow for such an assessment in the early stages of product development. One of these methods is the lane change task (LCT), a simple driving simulation in which the driver has to change lanes as indicated by different signs along the road. Although the LCT is an ISO sanctioned procedure, there are still open questions. One issue are learning effects which have been found in previous studies and which have the potential to compromise the comparability of test results. In this paper, we present results on two experiments that further explored the effect of previous experience on LCT and secondary task performance. The results confirm that learning effects occur when combining the LCT with a realistic secondary task. Also, we found evidence for the transfer of learning from one secondary task to another to some degree, provided that the two tasks are sufficiently similar.

  8. The Combined Effects of Online Planning and Task Structure on Complexity, Accuracy and Fluency of L2 Speech

    ERIC Educational Resources Information Center

    Javad Ahmadian, Mohammad; Tavakoli, Mansoor; Vahid Dastjerdi, Hossein

    2015-01-01

    This study investigates the combined effects of task-based careful online planning and the storyline structure of a task on second language performance (complexity, accuracy and fluency). Sixty intermediate EFL learners were randomly assigned to four groups (n = 15). Participants were asked to perform two tasks with different degrees of storyline…

  9. Human Health Effects, Task Force Assessment, Preliminary Report.

    ERIC Educational Resources Information Center

    Aronow, Wilbert S.; And Others

    Presented in this preliminary report is one of seven assessments conducted by a special task force of Project Clean Air, the Human Health Effects Task Force. The reports summarize assessments of the state of knowledge on various air pollution problems, particularly in California, and make tentative recommendations as to what the University of…

  10. Report of the Task Force on Institutional Effectiveness Measures.

    ERIC Educational Resources Information Center

    Arizona State Board of Directors for Community Colleges, Phoenix.

    The Task Force on Institutional Effectiveness Measures was formed by the State Board of Directors for Community Colleges of Arizona to develop a statewide plan for systematically demonstrating the degree to which community colleges accomplish their diverse missions. Two subgroups were formed in the Task Force on transfer and college programs and…

  11. Effects of Antihistamine, Age, And Gender on Task Performance

    DTIC Science & Technology

    1999-07-01

    This investigation was designed to study the effects of the antihistamine, chlorpheniramine maleate, as well as the influence of age and gender...singly and in combination with chlorpheniramine maleate, on selected types of performance tasks. It was hypothesized that chiorpheniramine maleate would... chlorpheniramine maleate on any dependent measure for any performance task. However, several interactions of age and gender with chlorpheniramine maleate

  12. Effect of Alignment on Text Cohesion in the Continuation Task

    ERIC Educational Resources Information Center

    Jiang, Lin; Xu, Xin

    2016-01-01

    A continuation task provides learners with a text with its ending removed and requires them to complete it through writing in a most coherent and logical way. The current study investigated (a) whether the continuation task had a positive effect on text cohesion and (b) whether texts produced by pairs exhibited higher cohesion than those produced…

  13. Effects of Variations in Task Design on Mathematics Teachers' Learning Experiences: A Case of a Sorting Task

    ERIC Educational Resources Information Center

    Koichu, Boris; Zaslavsky, Orit; Dolev, Lea

    2016-01-01

    The goal of the study presented in this article was to examine how variations in task design may affect mathematics teachers' learning experiences. The study focuses on sorting tasks, i.e., learning tasks that require grouping a given set of mathematical items, in as many ways as possible, according to different criteria suggested by the learners.…

  14. Interactive effects of task difficulty and personality on mood and heart rate variability.

    PubMed

    Sakuragi, Sokichi; Sugiyama, Yoshiki

    2004-05-01

    Susceptibility to stress would presumably be different from person to person and be affected by the cause of the given stress. The purpose of this study was to investigate the interactive effects of task difficulty and subject's personality on mood and autonomic nervous function when stress was induced experimentally by tasks involving 3 degrees of difficulty: easy (Task A), difficult but controllable (Task B), and very difficult and uncontrollable (Task C). Twelve healthy female subjects volunteered for the experiment. We assessed their personalities using the Minnesota Multiphasic Personality Inventory (MMPI) questionnaire. Mood states were evaluated by a profile of mood states and a frontal alpha laterality ratio (FALR). Autonomic nervous function was estimated by a spectral analysis of heart rate variability (HRV). Repeated measures analysis of variance applied to two groups (low- and high-) divided by a median split of MMPI clinical scales, revealed significant interactions of time course x task difficulty x Hs (hypochondriasis) in FALR and time course x task difficulty x Pt (psychasthenia) in a low-frequency component and in a high-frequency component of HRV, and in FALR. The differences between low- and high-Hs, and low- and high-Pt were more obvious in Task B session. High-Hs group, whose members tend to place overemphasis on existing physical disorders, showed more negative FALR throughout the session, which would indicate prolonged negative mood possibly due to the task. High-Pt group, whose members tend to be susceptible to stress, showed sympathetic predominance during task period and parasympathetic predominance after task period, which would imply a tendency to overreact. These results suggest that task difficulties would affect mood states assessed by FALR and/or autonomic nervous function differently depending on the subject's personality, especially on Hs and Pt.

  15. The effects of task difficulty and workload on training

    NASA Technical Reports Server (NTRS)

    Mane, Amir; Wickens, Christopher D.

    1986-01-01

    Four hypotheses regarding the possible effects of workload and task difficulty on training are proposed. These are: (1) increased levels of task difficulty will facilitate learning to the extent that these increases are (a) resource loading and (b) intrinsic to the component task to be learned; (2) decrease of task difficulty will facilitate learning to the extent that these decreases (a) reduce the resource load and (b) are extrinsic of the component task to be learned; (3) the lerner's tendency to conserve resources may bead to the adoption of undesirable, short-term, low resource strategies early in training; and (4) the effect of changes in resource demand on learning will depend upon the similarity of the resource whose demand is changed to the resource involved in learning.

  16. Circadian Effects on Simple Components of Complex Task Performance

    NASA Technical Reports Server (NTRS)

    Clegg, Benjamin A.; Wickens, Christopher D.; Vieane, Alex Z.; Gutzwiller, Robert S.; Sebok, Angelia L.

    2015-01-01

    The goal of this study was to advance understanding and prediction of the impact of circadian rhythm on aspects of complex task performance during unexpected automation failures, and subsequent fault management. Participants trained on two tasks: a process control simulation, featuring automated support; and a multi-tasking platform. Participants then completed one task in a very early morning (circadian night) session, and the other during a late afternoon (circadian day) session. Small effects of time of day were seen on simple components of task performance, but impacts on more demanding components, such as those that occur following an automation failure, were muted relative to previous studies where circadian rhythm was compounded with sleep deprivation and fatigue. Circadian low participants engaged in compensatory strategies, rather than passively monitoring the automation. The findings and implications are discussed in the context of a model that includes the effects of sleep and fatigue factors.

  17. Influences on Group Productivity 1: Factors Inherent in the Task. A bibliographic Synopsis

    DTIC Science & Technology

    1983-04-15

    rtal recommnendat ions : I. It would be useful, and perhaos recessary. tc, car-•-v out a Parametric study of group Problem so:’vin, tasks. Such a o study...Ha~miond & Go’ oman , I .Human rellac ions NN consen5 us 196i S’n a’ w & Blum, 1966 Dicssol/iý 5 success traits N N, con!sensus -.Human re’-tic~ns NN...Kabanoff & O’Brien, 1 .Product ion (ideas)’ consensus 1197 9i(a) 2.Discussion I N consensus 3.Problem-solving N N1 consensus ?-oDanOff & -’ren, .Produc::on

  18. Orthographic and morphemic effects in the written syllable counting task.

    PubMed

    Chetail, Fabienne; Quémart, Pauline

    2014-01-01

    According to a recent hypothesis, the organization of letters into groups of successive consonants and vowels (i.e., CV pattern) constrains the orthographic structure of words. Here, we examined to what extent the morphological structure of words modifies the influence of the CV pattern in a syllable counting task. Participants were presented with written words matched for the number of syllables and comprising either one vowel cluster less than the number of syllables (hiatus words, e.g., création) or the same number of vowel clusters (control words, e.g., crépiter). Participants were slower and less accurate for hiatus than control stimuli, be it words (Experiments 1, 3) or pseudowords (Experiment 2). More importantly, this hiatus effect was present even when the stimuli had a morphemic boundary falling within the hiatus (e.g., ré-agir). The results suggest that the CV pattern of items more strongly influences performance in the syllable counting task than the morphological structure.

  19. NASA Engineering Safety Center NASA Aerospace Flight Battery Systems Working Group 2007 Proactive Task Status

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle A.

    2007-01-01

    In 2007, the NASA Engineering Safety Center (NESC) chartered the NASA Aerospace Flight Battery Systems Working Group to bring forth and address critical battery-related performance/manufacturing issues for NASA and the aerospace community. A suite of tasks identifying and addressing issues related to Ni-H2 and Li-ion battery chemistries was submitted and selected for implementation. The current NESC funded are: (1) Wet Life of Ni-H2 Batteries (2) Binding Procurement (3) NASA Lithium-Ion Battery Guidelines (3a) Li-Ion Performance Assessment (3b) Li-Ion Guidelines Document (3b-i) Assessment of Applicability of Pouch Cells for Aerospace Missions (3b-ii) High Voltage Risk Assessment (3b-iii) Safe Charge Rates for Li-Ion Cells (4) Availability of Source Material for Li-Ion Cells (5) NASA Aerospace Battery Workshop This presentation provides a brief overview of the tasks in the 2007 plan and serves as an introduction to more detailed discussions on each of the specific tasks.

  20. Waste Area Grouping 2 Remedial Investigation Phase 1 Seep Task data report: Contaminant source area assessment

    SciTech Connect

    Hicks, D.S.

    1996-03-01

    This report presents the findings of the Waste Area Grouping (WAG) 2, Phase 1 Remedial Investigation (RI) Seep Task efforts during 1993 and 1994 at Oak Ridge National Laboratory (ORNL). The results presented here follow results form the first year of sampling, 1992, which are contained in the Phase 1 RI report for WAG 2 (DOE 1995a). The WAG 2 Seep Task efforts focused on contaminants in seeps, tributaries, and main streams within the White Oak Creek (WOC) watershed. This report is designed primarily as a reference for contaminants and a resource for guiding remedial decisions. Additional in-depth assessments of the Seep Task data may provide clearer understandings of contaminant transport from the different source areas in the WOC watershed. WAG 2 consists of WOC and its tributaries downstream of the ORNL main plant area, White Oak Lake, the White Oak Creek Embayment of the Clinch River, and the associated flood plains and subsurface environment. The WOC watershed encompasses ORNL and associated WAGs. WAG 2 acts as an integrator for contaminant releases from the contaminated sites at ORNL and as the conduit transporting contaminants to the Clinch River. The main objectives of the Seep Task were to identify and characterize seeps, tributaries and source areas that are responsible for the contaminant releases to the main streams in WAG 2 and to quantify their input to the total contaminant release from the watershed at White Oak Dam (WOD). Efforts focused on {sup 90}Sr, {sup 3}H, and {sup 137}Cs because these contaminants pose the greatest potential human health risk from water ingestion at WOD. Bimonthly sampling was conducted throughout the WOC watershed beginning in March 1993 and ending in August 1994. Samples were also collected for metals, anions, alkalinity, organics, and other radionuclides.

  1. Group Leader Development: Effects of Personal Growth and Psychoeducational Groups

    ERIC Educational Resources Information Center

    Ohrt, Jonathan H.; Robinson, E. H., III; Hagedorn, W. Bryce

    2013-01-01

    The purpose of this quasi-experimental study was to compare the effects of personal growth groups and psychoeducational groups on counselor education students' (n = 74) empathy and group leader self-efficacy. Additionally, we compared the degree to which participants in each group valued: (a) cohesion, (b) catharsis, and (c) insight. There were no…

  2. Brazilian Normative Data on Letter and Category Fluency Tasks: Effects of Gender, Age, and Geopolitical Region

    PubMed Central

    Hazin, Izabel; Leite, Gilmara; Oliveira, Rosinda M.; Alencar, João C.; Fichman, Helenice C.; Marques, Priscila d. N.; de Mello, Claudia Berlim

    2016-01-01

    Verbal fluency is a basic function of language that refers to the ability to produce fluent speech. Despite being an essentially linguistic function, its measurements are also used to evaluate executive aspects of verbal behavior. Performance in verbal fluency (VF) tasks varies according to age, education, and cognitive development. Neurodevelopmental disorders that affect the functioning of frontal areas tend to cause lower performance in VF tasks. Despite the relative consensus that has been reached in terms of the use of VF tasks for the diagnosis of dyslexia and attention-deficit/hyperactivity disorder, few studies have considered regional variations in Brazil. The present study sought to provide normative data on VF tasks in children by considering gender, age, education, and geopolitical region of origin with auxiliary purposes in neuropsychological diagnosis of disorders that occur with executive changes The study included 298 participants, 7–10 years of age of both genders, who performed three letter fluency tasks and three category fluency tasks. The data were subjected to correlational and variance analyses, with age and gender as factors. No effect of gender on the children's performance was found. However, significant differences between age groups were observed, with better performance in letter tasks in older children and better performance in letter tasks compared with category tasks. Significant regional differences in performance on the letter VF task were observed. These results reinforce the importance of regional normative data in countries with high regional cultural variations, such as Brazil. PMID:27242598

  3. A Mozart effect for women on a mental rotations task.

    PubMed

    Gilleta, Karen S; Vrbancic, Mirna I; Elias, Lorin J; Saucier, Deborah M

    2003-06-01

    During the past decade, there have been numerous reports of a brief, but statistically significant, improvement in immediate spatial-temporal performance after listening to 10 min. of Mozart's Sonata K.448, known as the "Mozart effect." The purpose of the present study was to assess whether production of the effect is influenced by length of listening conditions or sex. Each of 52 right-handed participants (26 females, 26 males) completed a paper-folding and cutting task and a Mental Rotations task following a listening condition in which the Mozart sonata was played and a silent condition (no music was played). A significant 3-way interaction among sex, listening condition, and task indicated that an effect was present only for women on the Mental Rotations task. As such, researchers should investigate the role of sex in production of the Mozart effect.

  4. The effects of feedback and positive reinforcement on the on-task behavior of dancers.

    PubMed

    Liberatore, Jennica S; Luyben, Paul D

    2009-01-01

    The purpose of this study was to investigate the effects of feedback on the on-task behavior of adolescent members of a dance company in central New York. The intervention consisted of immediate group and delayed individual feedback. We used a single-subject reversal design. We hypothesized that implementation of the feedback conditions would increase overall on-task rates and decrease variability relative to baseline rates. The data supported this hypothesis with increased on-task rates and decreased variability when the intervention was in effect.

  5. Pig in the Middle? Effects of Mediating Tasks on Cognitive Processing of Text.

    ERIC Educational Resources Information Center

    Allison, Desmond; And Others

    This study of second language learning investigated the effects of a written reading comprehension exercise and an oral discussion activity as alternative tasks mediating between a written text and learners' summaries of the text. Subjects were 80 University of Hong Kong freshmen, randomly assigned to three groups. Each group was provided a…

  6. Effect of Goal Setting on the Strategies Used to Solve a Block Design Task

    ERIC Educational Resources Information Center

    Rozencwajg, Paulette; Fenouillet, Fabien

    2012-01-01

    In this experiment we studied the effect of goal setting on the strategies used to perform a block design task called SAMUEL. SAMUEL can measure many indicators, which are then combined to determine the strategies used by participants when solving SAMUEL problems. Two experimental groups were created: one group was given an explicit, difficult…

  7. Sleep Restriction during Simulated Wildfire Suppression: Effect on Physical Task Performance

    PubMed Central

    Vincent, Grace; Ferguson, Sally A.; Tran, Jacqueline; Larsen, Brianna; Wolkow, Alexander; Aisbett, Brad

    2015-01-01

    Objectives To examine the effects of sleep restriction on firefighters’ physical task performance during simulated wildfire suppression. Methods Thirty-five firefighters were matched and randomly allocated to either a control condition (8-hour sleep opportunity, n = 18) or a sleep restricted condition (4-hour sleep opportunity, n = 17). Performance on physical work tasks was evaluated across three days. In addition, heart rate, core temperature, and worker activity were measured continuously. Rate of perceived and exertion and effort sensation were evaluated during the physical work periods. Results There were no differences between the sleep-restricted and control groups in firefighters’ task performance, heart rate, core temperature, or perceptual responses during self-paced simulated firefighting work tasks. However, the sleep-restricted group were less active during periods of non-physical work compared to the control group. Conclusions Under self-paced work conditions, 4 h of sleep restriction did not adversely affect firefighters’ performance on physical work tasks. However, the sleep-restricted group were less physically active throughout the simulation. This may indicate that sleep-restricted participants adapted their behaviour to conserve effort during rest periods, to subsequently ensure they were able to maintain performance during the firefighter work tasks. This work contributes new knowledge to inform fire agencies of firefighters’ operational capabilities when their sleep is restricted during multi-day wildfire events. The work also highlights the need for further research to explore how sleep restriction affects physical performance during tasks of varying duration, intensity, and complexity. PMID:25615988

  8. Friendship group identification, multidimensional self-concept, and experience of developmental tasks in adolescence.

    PubMed

    Tarrant, Mark; MacKenzie, Liam; Hewitt, Lisa A

    2006-08-01

    This study applied a social identity perspective to the study of adolescent self-concept and social development. British adolescents aged 14-15 years (N=114) completed a questionnaire which asked them to: (i) rate their degree of identification with a school-based friendship group; (ii) complete a measure of multi-dimensional self-concept; and (iii) report their experiences of a variety of personal, relational and socio-institutional (e.g., achieving economic independence) developmental tasks. Compared to low identifiers, participants who were highly identified with a friendship group reported highest levels of self-esteem; and these differences were most marked in non-academic domains of self. High identifiers also displayed higher levels of general self-esteem and reported more positive experiences of personal and relational developmental tasks. The discussion focuses on the potential benefits to understanding of social developmental processes that can be derived from a consideration of adolescents' subjective appraisals of their peer relations.

  9. Age difference in dual-task interference effects on procedural learning in children.

    PubMed

    Lejeune, Caroline; Desmottes, Lise; Catale, Corinne; Meulemans, Thierry

    2015-01-01

    The current study aimed to investigate the role played by explicit mechanisms during procedural learning in two age groups of children (7 and 10 years) using a dual-task paradigm. To do this, we explored the effect of an interference task during the early and late phases of a mirror tracing learning task. The results showed a differential impact of the secondary task on the two age groups, but only during the first learning phase; the performance of 10-year-olds was affected by the second task, whereas in 7-year-olds no performance difference was found between the single- and dual-task conditions. Overall, our study suggests that there are differences in the amount of effortful processing in which 7- and 10-year-olds engage at the beginning of the learning process; procedural learning in young children is mainly implicit, as attested by its lesser sensitivity to an interference task, whereas high-level explicit mechanisms seem to contribute to the procedural performance of 10-year-olds. However, these explicit mechanisms, even if they have an effect on performance, might not have an impact on the learning curve given that no difference in rate of acquisition was found between age groups. These findings are discussed in the light of classical conceptions of procedural learning.

  10. The effects of stimulus modality and task integrality: Predicting dual-task performance and workload from single-task levels

    NASA Technical Reports Server (NTRS)

    Hart, S. G.; Shively, R. J.; Vidulich, M. A.; Miller, R. C.

    1986-01-01

    The influence of stimulus modality and task difficulty on workload and performance was investigated. The goal was to quantify the cost (in terms of response time and experienced workload) incurred when essentially serial task components shared common elements (e.g., the response to one initiated the other) which could be accomplished in parallel. The experimental tasks were based on the Fittsberg paradigm; the solution to a SternBERG-type memory task determines which of two identical FITTS targets are acquired. Previous research suggested that such functionally integrated dual tasks are performed with substantially less workload and faster response times than would be predicted by suming single-task components when both are presented in the same stimulus modality (visual). The physical integration of task elements was varied (although their functional relationship remained the same) to determine whether dual-task facilitation would persist if task components were presented in different sensory modalities. Again, it was found that the cost of performing the two-stage task was considerably less than the sum of component single-task levels when both were presented visually. Less facilitation was found when task elements were presented in different sensory modalities. These results suggest the importance of distinguishing between concurrent tasks that complete for limited resources from those that beneficially share common resources when selecting the stimulus modalities for information displays.

  11. Effects of instructed focus and task difficulty on concurrent walking and cognitive task performance in healthy young adults.

    PubMed

    Kelly, Valerie E; Janke, Alexis A; Shumway-Cook, Anne

    2010-11-01

    Dual task paradigms can be used to examine the interactions between cognition and the control of posture and gait. Measuring and interpreting changes in dual task performance is challenging, however, because many factors can influence performance. This study examined the effects of instructed focus and walking task difficulty, and the interaction between these factors, on dual task performance in healthy young adults. Fifteen participants performed a cognitive task while walking with either a usual base or a narrow base of support. Participants were instructed to focus on either the cognitive task or walking. Trade-offs both within and between tasks were assessed using the modified attention allocation index and the performance operating characteristic. Instructed focus influenced both the cognitive task and walking. Performance on the cognitive task was faster with instructions to focus on the cognitive task, and walking was faster (and more accurate in the narrow-base condition) with instructions to focus on walking. Walking task difficulty did not affect cognitive performance but did affect walking, with faster walking in the usual-base versus narrow-base condition. There was evidence of an interaction, with greater effects of instructed focus on the cognitive task during usual versus narrow-base walking. These results support the idea that the ability to flexibly shift attention allocation and task performance in response to instructions depends on the difficulty of the postural control task. The modified attention allocation index and the performance operating characteristic were instrumental in fully characterizing trade-offs between and within tasks in order to understand dual task performance changes. A clearer understanding of the factors that affect dual task walking and the interactions between these factors has important implications for the assessment of dual task performance in both clinical and research settings.

  12. The carry-over effect of competition in task-sharing: evidence from the joint Simon task.

    PubMed

    Iani, Cristina; Anelli, Filomena; Nicoletti, Roberto; Rubichi, Sandro

    2014-01-01

    The Simon effect, that is the advantage of the spatial correspondence between stimulus and response locations when stimulus location is a task-irrelevant dimension, occurs even when the task is performed together by two participants, each performing a go/no-go task. Previous studies showed that this joint Simon effect, considered by some authors as a measure of self-other integration, does not emerge when during task performance co-actors are required to compete. The present study investigated whether and for how long competition experienced during joint performance of one task can affect performance in a following joint Simon task. In two experiments, we required pairs of participants to perform together a joint Simon task, before and after jointly performing together an unrelated non-spatial task (the Eriksen flanker task). In Experiment 1, participants always performed the joint Simon task under neutral instructions, before and after performing the joint flanker task in which they were explicitly required either to cooperate with (i.e., cooperative condition) or to compete against a co-actor (i.e., competitive condition). In Experiment 2, they were required to compete during the joint flanker task and to cooperate during the subsequent joint Simon task. Competition experienced in one task affected the way the subsequent joint task was performed, as revealed by the lack of the joint Simon effect, even though, during the Simon task participants were not required to compete (Experiment 1). However, prior competition no longer affected subsequent performance if a new goal that created positive interdependence between the two agents was introduced (Experiment 2). These results suggest that the emergence of the joint Simon effect is significantly influenced by how the goals of the co-acting individuals are related, with the effect of competition extending beyond the specific competitive setting and affecting subsequent interactions.

  13. Total Class Peer Tutoring and Interdependent Group Oriented Contingency: Improving the Academic and Task Related Behaviors of Fourth-Grade Urban Students

    ERIC Educational Resources Information Center

    Lo,Ya-yu; Cartledge, Gwendolyn

    2004-01-01

    This study investigated the effects of Total Class Peer Tutoring (TCPT) and an interdependent group oriented contingency (GOC) on the social studies performances and off-task behaviors of eight general education fourth-grade students in an urban elementary school. An A-B-BC-B-BC design was implemented to evaluate the differential effects of TCPT…

  14. The Effect of Cognitive-Task Type and Walking Speed on Dual-Task Gait in Healthy Adults.

    PubMed

    Wrightson, James G; Ross, Emma Z; Smeeton, Nicholas J

    2016-01-01

    In a number of studies in which a dual-task gait paradigm was used, researchers reported a relationship between cognitive function and gait. However, it is not clear to what extent these effects are dependent on the type of cognitive and walking tasks used in the dual-task paradigm. This study examined whether stride-time variability (STV) and trunk range of motion (RoM) are affected by the type of cognitive task and walking speed used during dual-task gait. Participants walked at both their preferred walking speed and at 25% of their preferred walking speed and performed a serial subtraction and a working memory task at both speeds. Although both tasks significantly reduced STV at both walking speeds, there was no difference between the two tasks. Trunk RoM was affected by the walking speed and type of cognitive task used during dual-task gait: Mediolateral trunk RoM was increased at the slow walking speed, and anterior-posterior trunk RoM was higher only when performing the serial subtraction task at the slow walking speed. The reduction of STV, regardless of cognitive-task type, suggests that healthy adults may redirect cognitive processes away from gait toward cognitive-task performance during dual-task gait.

  15. Designing and Examining the Effects of a Dynamic Geometry Task Analysis Framework on Teachers' Written Geometer's Sketchpad Tasks

    ERIC Educational Resources Information Center

    Trocki, Aaron David

    2015-01-01

    This study investigates the usefulness of a Dynamic Geometry Task Analysis Framework for indicating task quality in dynamic geometry environments in general, and The Geometer's Sketchpad in particular. This research sought to first establish the validity of the framework for indicating task quality, and to second explore the effects of the…

  16. Learning redundant motor tasks with and without overlapping dimensions: facilitation and interference effects.

    PubMed

    Ranganathan, Rajiv; Wieser, Jon; Mosier, Kristine M; Mussa-Ivaldi, Ferdinando A; Scheidt, Robert A

    2014-06-11

    Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of participants learned two tasks: a prior task that was unique to each group and a criterion task that was common to all groups. We manipulated the mapping between finger motions and cursor positions in the prior task to define task spaces that either shared or did not share the task space dimensions (x-y axes) of the criterion task. We found that if the prior task shared task dimensions with the criterion task, there was an initial facilitation in criterion task performance. However, if the prior task did not share task dimensions with the criterion task, there was prolonged interference in learning the criterion task due to participants finding inefficient task solutions. These results show that the nervous system learns the task space through practice, and that the degree of shared task space dimensionality influences the extent to which prior experience transfers to subsequent learning of related motor skills.

  17. Effects of manual task complexity on gait parameters in school-aged children and adults.

    PubMed

    Abbruzzese, Laurel D; Rao, Ashwini K; Bellows, Rachel; Figueroa, Kristina; Levy, Jennifer; Lim, Esther; Puccio, Lauren

    2014-09-01

    This study examined the dual-task interference effects of complexity (simple vs. complex), type of task (carrying a pitcher vs. tray), and age (young adults vs. 7-10 year old children) on temporal-spatial and variability measures of gait. All participants first walked on the GAITRite walkway without any concurrent task, followed by four dual-task gait conditions. The group of children had a more variable step length and step time than adults across all walking conditions. They also slowed down, took fewer, smaller steps and spent more time in double limb support than adults in the complex dual task conditions. Gait in healthy young adults and school aged children was relatively unaffected by concurrent performance of simple versions of the manual tasks. Our overall analysis suggests that dual-task gait in school aged children is still developing and has not yet reached adult capacity. This study also highlights the critical role of task demand and complexity in dual-task interference.

  18. The report of Task Group 100 of the AAPM: Application of risk analysis methods to radiation therapy quality management

    PubMed Central

    Huq, M. Saiful; Fraass, Benedick A.; Dunscombe, Peter B.; Gibbons, John P.; Mundt, Arno J.; Mutic, Sasa; Palta, Jatinder R.; Rath, Frank; Thomadsen, Bruce R.; Williamson, Jeffrey F.; Yorke, Ellen D.

    2016-01-01

    The increasing complexity of modern radiation therapy planning and delivery challenges traditional prescriptive quality management (QM) methods, such as many of those included in guidelines published by organizations such as the AAPM, ASTRO, ACR, ESTRO, and IAEA. These prescriptive guidelines have traditionally focused on monitoring all aspects of the functional performance of radiotherapy (RT) equipment by comparing parameters against tolerances set at strict but achievable values. Many errors that occur in radiation oncology are not due to failures in devices and software; rather they are failures in workflow and process. A systematic understanding of the likelihood and clinical impact of possible failures throughout a course of radiotherapy is needed to direct limit QM resources efficiently to produce maximum safety and quality of patient care. Task Group 100 of the AAPM has taken a broad view of these issues and has developed a framework for designing QM activities, based on estimates of the probability of identified failures and their clinical outcome through the RT planning and delivery process. The Task Group has chosen a specific radiotherapy process required for “intensity modulated radiation therapy (IMRT)” as a case study. The goal of this work is to apply modern risk-based analysis techniques to this complex RT process in order to demonstrate to the RT community that such techniques may help identify more effective and efficient ways to enhance the safety and quality of our treatment processes. The task group generated by consensus an example quality management program strategy for the IMRT process performed at the institution of one of the authors. This report describes the methodology and nomenclature developed, presents the process maps, FMEAs, fault trees, and QM programs developed, and makes suggestions on how this information could be used in the clinic. The development and implementation of risk-assessment techniques will make radiation

  19. Multiple Effects of Prefrontal Lesions on Task-Switching

    PubMed Central

    Shallice, Tim; Stuss, Donald T.; Picton, Terence W.; Alexander, Michael P.; Gillingham, Susan

    2007-01-01

    This study examined the performance of 41 patients with focal prefrontal cortical lesions and 38 healthy controls on a task-switching procedure. Three different conditions were evaluated: single tasks without switches and two switching tasks with the currently relevant task signalled either 1500 ms (Long Cue) or 200 ms (Short Cue) before the stimulus. Patients with Superior Medial lesions showed both a general slowing of reaction time (RT) and a significantly increased switch cost as measured by RT. No other prefrontal group showed this increased reaction time switch cost. Increased error rates in the switching conditions, on the other hand, were observed in patients with Inferior Medial lesions and, to a lesser extent, ones with Superior Medial lesions. Patients with left dorsolateral lesions (9/46v) showed slower learning of the task as indicated by a high error rate early on. Several different processes are involved in task-switching and these are selectively disrupted by lesions to specific areas of the frontal lobes. PMID:18958216

  20. Ongoing quality control in digital radiography: Report of AAPM Imaging Physics Committee Task Group 151

    SciTech Connect

    Jones, A. Kyle Geiser, William; Heintz, Philip; Goldman, Lee; Jerjian, Khachig; Martin, Melissa; Peck, Donald; Pfeiffer, Douglas; Ranger, Nicole; Yorkston, John

    2015-11-15

    Quality control (QC) in medical imaging is an ongoing process and not just a series of infrequent evaluations of medical imaging equipment. The QC process involves designing and implementing a QC program, collecting and analyzing data, investigating results that are outside the acceptance levels for the QC program, and taking corrective action to bring these results back to an acceptable level. The QC process involves key personnel in the imaging department, including the radiologist, radiologic technologist, and the qualified medical physicist (QMP). The QMP performs detailed equipment evaluations and helps with oversight of the QC program, the radiologic technologist is responsible for the day-to-day operation of the QC program. The continued need for ongoing QC in digital radiography has been highlighted in the scientific literature. The charge of this task group was to recommend consistency tests designed to be performed by a medical physicist or a radiologic technologist under the direction of a medical physicist to identify problems with an imaging system that need further evaluation by a medical physicist, including a fault tree to define actions that need to be taken when certain fault conditions are identified. The focus of this final report is the ongoing QC process, including rejected image analysis, exposure analysis, and artifact identification. These QC tasks are vital for the optimal operation of a department performing digital radiography.

  1. SU-E-P-22: AAPM Task Group 263 Tackling Standardization of Nomenclature for Radiation Therapy

    SciTech Connect

    Matuszak, M; Feng, M; Moran, J; Xiao, Y; Mayo, C; Miller, R; Bosch, W; Popple, R; Marks, L; Wu, Q; Molineu, A; Martel, M; Yock, T; McNutt, T; Brown, N; Purdie, T; Yorke, E; Santanam, L; Gabriel, P; Michalski, J; and others

    2015-06-15

    Purpose: There is growing recognition of need for increased clarity and consistency in the nomenclatures used for body and organ structures, DVH metrics, toxicity, dose and volume units, etc. Standardization has multiple benefits; e.g. facilitating data collection for clinical trials, enabling the pooling of data between institutions, making transfers (i.e. hand-offs) between centers safer, and enabling vendors to define “default” settings. Towards this goal, the American Association of Physicists in Medicine (AAPM) formed a task group (TG263) in July of 2014, operating under the Work Group on Clinical Trials to develop consensus statements. Guiding principles derived from the investigation and example nomenclatures will be presented for public feedback. Methods: We formed a multi-institutional and multi-vendor collaborative group of 39 physicists, physicians and others involved in clinical use and electronic transfer of information. Members include individuals from IROC, NRG, IHE-RO, DICOM WG-7, ASTRO and EORTC groups with overlapping interests to maximize the quality of the consensus and increase the likelihood of adoption. Surveys of group and NRG members were used to define current nomenclatures and requirements. Technical requirements of vendor systems and the proposed DICOM standards were examined. Results: There is a marked degree of inter and intra institutional variation in current approaches, resulting from inter-vendor differences in capabilities, clinic specific conceptualizations and inconsistencies. Using a consensus approach, the group defined optimal formats for the naming of targets and normal structures. A formal objective assessment of 13 existing clinically-used software packages show that all had capabilities to accommodate these recommended nomenclatures. Conclusions: A multi-stakeholder effort is making significant steps forward in developing a standard nomenclature that will work across platforms. Our current working list includes > 550

  2. The work of the ICRP dose calculational task group: Issues in implementation of the ICRP dosimetric methodology

    SciTech Connect

    Eckerman, K.F.

    1999-01-01

    Committee 2 of the International Commission on Radiological Protection (ICRP) has had efforts underway to provide the radiation protection community with age-dependent dose coefficients, i.e.g, the dose per unit intake. The Task Group on Dose Calculations, chaired by the author, is responsible for the computation of these coefficients. The Task Group, formed in 1974 to produce ICRP Publication 30, is now international in its membership and its work load has been distributed among the institutions represented on the task group. This paper discusses: (1) recent advances in biokinetic modeling; (2) the recent changes in the dosimetric methodology; (3) the novel computational problems with some of the ICRP quantities; and (4) quality assurance issues which the Task Group has encountered. Potential future developments of the dosimetric framework which might strengthen the relationships with the emerging understanding of radiation risk will also be discussed.

  3. AAPM Task Group 128: Quality assurance tests for prostate brachytherapy ultrasound systems

    SciTech Connect

    Pfeiffer, Douglas; Sutlief, Steven; Feng Wenzheng; Pierce, Heather M.; Kofler, Jim

    2008-12-15

    While ultrasound guided prostate brachytherapy has gained wide acceptance as a primary treatment tool for prostate cancer, quality assurance of the ultrasound guidance system has received very little attention. Task Group 128 of the American Association of Physicists in Medicine was created to address quality assurance requirements specific to transrectal ultrasound used for guidance of prostate brachytherapy. Accurate imaging guidance and dosimetry calculation depend upon the quality and accuracy of the ultrasound image. Therefore, a robust quality assurance program for the ultrasound system is essential. A brief review of prostate brachytherapy and ultrasound physics is provided, followed by a recommendation for elements to be included in a comprehensive test phantom. Specific test recommendations are presented, covering grayscale visibility, depth of penetration, axial and lateral resolution, distance measurement, area measurement, volume measurement, needle template/electronic grid alignment, and geometric consistency with the treatment planning computer.

  4. Nomenclature of homodetic cyclic peptides produced from ribosomal precursors: An IUPAC task group interim report.

    PubMed

    Craik, David J; Young Shim, Youn; Göransson, Ulf; Moss, Gerard P; Tan, Ninghua; Jadhav, Pramodkumar D; Shen, Jianheng; Reaney, Martin J T

    2016-11-01

    In 2015, an International Union of Pure and Applied Chemistry (IUPAC) Task Group was formed to develop nomenclature recommendations for homodetic cyclic peptides produced from ribosomal precursors. Delegates of the 2015 International Conference on Circular Proteins (ICCP) were presented with the strengths and weaknesses of four published approaches to homodetic cyclic peptide nomenclature, and a summary of the ensuing discussion is presented here. This interim report presents a potentially novel suggestion-the use of Cahn-Ingold-Prelog rules to specify amino acid priority in homodetic peptides for consistent numbering. Indeed, this might be the first extension of the Cahn-Ingold-Prelog rules in five decades. The authors invite interested parties to contact the corresponding author with suggestions for the improvement of the proposed nomenclature; these ideas will be discussed and considered for inclusion in the final report.

  5. Effects of reading-oriented tasks on students' reading comprehension of geometry proof

    NASA Astrophysics Data System (ADS)

    Yang, Kai-Lin; Lin, Fou-Lai

    2012-06-01

    This study compared the effects of reading-oriented tasks and writing-oriented tasks on students' reading comprehension of geometry proof (RCGP). The reading-oriented tasks were designed with reading strategies and the idea of problem posing. The writing-oriented tasks were consistent with usual proof instruction for writing a proof and applying it. Twenty-two classes of ninth-grade students ( N = 683), aged 14 to 15 years, and 12 mathematics teachers participated in this quasi-experimental classroom study. While the experimental group was instructed to read and discuss the reading tasks in two 45-minute lessons, the control group was instructed to prove and apply the same propositions. Generalised estimating equation (GEE) method was used to compare the scores of the post-test and the delayed post-test with the pre-test scores as covariates. Results showed that the total scores of the delayed post-test of the experimental group were significantly higher than those of the control group. Furthermore, the scores of the experimental group on all facets of reading comprehension except the application facet were significantly higher than those of the control group for both the post-test and delayed post-test.

  6. Picture Novelty Influences Response Selection and Inhibition: The Role of the In-Group Bias and Task-Difficulty

    PubMed Central

    Zinchenko, Artyom; Mahmud, Waich; Alam, Musrura Mefta; Kabir, Nadia; Al-Amin, Md. Mamun

    2016-01-01

    The human visual system prioritizes processing of novel information, leading to faster detection of novel stimuli. Novelty facilitates conflict resolution through the enhanced early perceptual processing. However, the role of novel information processing during the conflict-related response selection and inhibition remains unclear. Here, we used a face-gender classification version of the Simon task and manipulated task-difficulty and novelty of task-relevant information. The novel quality of stimuli was made task-irrelevant, and an in-group bias was tightly controlled by manipulation of a gender of picture stimuli. We found that the in-group bias modulated the role of novelty in executive control. Novel opposite-sex stimuli facilitated response inhibition only when the task was not demanding. By contrast, novelty enhanced response selection irrespective of the in-group factor when task-difficulty was increased. These findings support the in-group bias mechanism of visual processing, in cases when attentional resources are not limited by a demanding task. The results are further discussed along the lines of the attentional load theory and neural mechanisms of response-inhibition and locomotor activity. In conclusion, our data showed that processing of novel information may enhance executive control through facilitated response selection and inhibition. PMID:27788213

  7. Initial judgment task and delay of the final validity-rating task moderate the truth effect.

    PubMed

    Nadarevic, Lena; Erdfelder, Edgar

    2014-01-01

    Repeatedly seen or heard statements are typically judged to be more valid than statements one has never encountered before. This phenomenon has been referred to as the truth effect. We conducted two experiments to assess the plasticity of the truth effect under different contextual conditions. Surprisingly, we did not find a truth effect in the typical judgment design when using a ten minutes interval between statement repetitions. However, we replicated the truth effect when changing the judgment task at initial statement exposure or when using an interval of one week rather than ten minutes. Because none of the current truth effect theories can fully account for these context effects, we conclude that the cognitive processes underlying truth judgments are more complex than has hitherto been assumed. To close the theoretical gap, we propose a revised fluency attribution hypothesis as a possible explanation of our findings.

  8. [Job performance in work organizations: the effects of management by group goals and job interdependence].

    PubMed

    Ikeda, Hiroshi; Furukawa, Hisataka

    2015-04-01

    cThis study examined the interactive effect of management by group goals and job interdependence on employee's activities in terms of task and contextual performance. A survey was conducted among 140 Japanese employees. Results indicated that management by group goals was related only to contextual performance. Job interdependence, however, had a direct effect on both task and contextual performance. Moreover, moderated regression analyses revealed that for work groups requiring higher interdependence among employees, management by group goals had a positive relation to contextual performance but not to task performance. When interdependence was not necessarily required, however, management by group goals had no relation to contextual performance and even negatively impacted task performance, respectively. These results show that management by group goals affects task and contextual performance, and that this effect is moderated by job interdependence. This provides a theoretical extension as well as a practical application to the setting and management of group goals.

  9. Differential Effects of Aging on Processes Underlying Task Switching

    ERIC Educational Resources Information Center

    West, Robert; Travers, Stephanie

    2008-01-01

    In this study, we used event-related brain potentials (ERPs) to examine the effects of aging on processes underlying task switching. The response time data revealed an age-related increase in mixing costs before controlling for general slowing and no effect of aging on switching costs. In the cue-locked epoch, the ERP data revealed little effect…

  10. Adapting the Crossmodal Congruency Task for Measuring the Limits of Visual-Tactile Interactions Within and Between Groups.

    PubMed

    Poole, Daniel; Couth, Samuel; Gowen, Emma; Warren, Paul A; Poliakoff, Ellen

    2015-01-01

    The crossmodal congruency task (CCT) is a commonly used paradigm for measuring visual-tactile interactions and how these may be influenced by discrepancies in space and time between the tactile target and visual distractors. The majority of studies which have used this paradigm have neither measured, nor attempted to control, individual variability in unisensory (tactile) performance. We have developed a version of the CCT in which unisensory baseline performance is constrained to enable comparisons within and between participant groups. Participants were instructed to discriminate between single and double tactile pulses presented to their dominant hand, at their own approximate threshold level. In Experiment 1, visual distractors were presented at -30 ms, 100 ms, 200 ms and 400 ms stimulus onset asynchronies. In Experiment 2, ipsilateral visual distractors were presented 0 cm, 21 cm, and 42 cm vertically from the target hand, and 42 cm in a symmetrical, contralateral position. Distractors presented -30 ms and 0 cm from the target produced a significantly larger congruency effect than at other time points and spatial locations. Thus, the typical limits of visual-tactile interactions were replicated using a version of the task in which baseline performance can be constrained. The usefulness of this approach is supported by the observation that tactile thresholds correlated with self-reported autistic traits in this non-clinical sample. We discuss the suitability of this adapted version of the CCT for measuring visual-tactile interactions in populations where unisensory tactile ability may differ within and between groups.

  11. Testing Idiom Comprehension in Aphasic Patients: The Effects of Task and Idiom Type

    ERIC Educational Resources Information Center

    Papagno, C.; Caporali, A.

    2007-01-01

    Idiom comprehension in 15 aphasic patients was assessed with three tasks: a sentence-to-picture matching task, a sentence-to-word matching task and an oral definition task. The results of all three tasks showed that the idiom comprehension in aphasic patients was impaired compared to that of the control group, and was significantly affected by the…

  12. The effects of sleep and sleep deprivation on task-switching performance.

    PubMed

    Couyoumdjian, Alessandro; Sdoia, Stefano; Tempesta, Daniela; Curcio, Giuseppe; Rastellini, Elisabetta; DE Gennaro, Luigi; Ferrara, Michele

    2010-03-01

    Neural systems of the prefrontal cortex (PFC) involved in executive functions are particularly vulnerable to sleep deprivation (SD). In this study, we investigated whether SD selectively affects specific components of the executive control processes involved in task-switching performance. Two different tasks are performed in rapid and random succession in this procedure, so that the to-be-executed task may change from one trial to the next (switch trial), or may be repeated (repetition trial). Task-switches are usually slower than task repetitions, giving way to the 'switch cost'. One hundred and eight university students were assigned randomly to the sleep (S) or the SD group. Each of them was tested on a task-switching paradigm before and after an experimental night (S or SD), and after one recovery night. SD impaired both task-switching accuracy and speed. A higher proportion of errors and increased switch costs after SD have been observed, compared to normal sleep. Control analyses on switch and repetition trials showed that the SD group was significantly worse only on the switch trials. The effects of SD are reverted by one night of recovery sleep. It is concluded that the ability to adjust behaviour rapidly and flexibly to changing environmental demands, which relies on the functional integrity of the PFC, is impacted negatively by sleep loss.

  13. Effects of Group I metabotropic glutamate receptor antagonists on sensitivity to reinforcer magnitude and delayed reinforcement in a delay-discounting task in rats: Contribution of delay presentation order.

    PubMed

    Yates, Justin R; Rogers, Katherine K; Gunkel, Benjamin T; Prior, Nicholas A; Hughes, Mallory N; Sharpe, Sara M; Campbell, Hunter L; Johnson, Anthony B; Keller, Margaret G; Breitenstein, Kerry A; Shults, Hansen N

    2017-03-30

    Metabotropic glutamate receptor 1 (mGluR1) blockade has been shown to decrease impulsive choice, as measured in delay discounting. However, several variables are known to influence an animal's discounting, including sensitivity to delayed reinforcement and sensitivity to reinforcer magnitude. The goal of this experiment was to determine the effects of mGluR1, as well as mGluR5, antagonism on these parameters. Forty Sprague Dawley rats were trained in delay discounting, in which consistently choosing a small, immediate reward reflects impulsive choice. For half of the rats, the delay to the large reinforcer increased across blocks of trials, whereas the delay decreased across the session for half of the rats. Following training, half of the rats received injections of the mGluR1 antagonist JNJ 16259685 (JNJ; 0, 0.1, 0.3, or 1.0mg/kg; i.p), and half received injections of the mGluR5 antagonist MPEP (0, 1.0, 3.0, or 10.0mg/kg; i.p.). Administration of JNJ increased sensitivity to delayed reinforcement (i.e., promoted impulsive choice), regardless of which schedule was used. However, the order in which delays were presented modulated the effects of JNJ on sensitivity to reinforcer magnitude. Specifically, JNJ decreased sensitivity to reinforcer magnitude in rats trained on the descending schedule only. MPEP did not alter sensitivity to reinforcer magnitude or sensitivity to delayed reinforcement. These results show that mGluR1 is an important mediator of impulsive choice, and they provide further evidence that delay order presentation is an important variable that influences drug effects in delay discounting.

  14. Effects of Single-Task Interference on Dual-Task Interference

    NASA Technical Reports Server (NTRS)

    Johnson, James C.; Ruthruff, Eric; VanSelst, Mark; Remington, Roger W.

    1998-01-01

    Van Sergi, Ruthruff and Johnston found that dual-task practice can markedly reduce interference in the Psychological Refractory Period paradigm. Their results are consistent with a bottleneck model in which practice serves primarily to reduce stage durations. This model predicts that single-task practice on Task 1 alone should produce marked reductions in interference, whereas single-task practice on Task 2 should not. New experiments test these predictions. Alternative theoretical accounts are also considered.

  15. Sharing a Task or Sharing Space? On the Effect of the Confederate in Action Coding in a Detection Task

    ERIC Educational Resources Information Center

    Guagnano, Delia; Rusconi, Elena; Umilta, Carlo Arrigo

    2010-01-01

    Several studies showed a Simon effect when two participants sit close to each other and perform one of the two halves of a two-choice RT task. That is, each participant perform a go-no go task. A Simon effect emerges, which instead is absent when the same go-nogo tasks are performed individually. Hence the terms were introduced of "social Simon…

  16. The preparation effect in task switching: carryover of SOA.

    PubMed

    Altmann, Erik M

    2004-01-01

    A common finding in task-switching studies is switch preparation (commonly known as the preparation effect), in which a longer interval between task cue and trial stimulus (i.e., a longer stimulus onset asynchrony, or SOA) reduces the cost of switching to a different task. Three experiments link switch preparation to within-subjects manipulations of SOA. In Experiment 1, SOA was randomized within subjects, producing switch preparation that was more pronounced when the SOA switched from the previous trial than when the SOA repeated. In Experiment 2, SOA was blocked within subjects, producing switch preparation but not on the first block of trials. In Experiment 3, SOA was manipulated between subjects with sufficient statistical power to detect switch preparation, but the effect was absent. The results favor an encoding view of cognitive control, but show that any putative switching mechanism reacts lazily when exposed to only one SOA.

  17. Recommendations for clinical electron beam dosimetry: supplement to the recommendations of Task Group 25.

    PubMed

    Gerbi, Bruce J; Antolak, John A; Deibel, F Christopher; Followill, David S; Herman, Michael G; Higgins, Patrick D; Huq, M Saiful; Mihailidis, Dimitris N; Yorke, Ellen D; Hogstrom, Kenneth R; Khan, Faiz M

    2009-07-01

    The goal of Task Group 25 (TG-25) of the Radiation Therapy Committee of the American Association of.Physicists in Medicine (AAPM) was to provide a methodology and set of procedures for a medical physicist performing clinical electron beam dosimetry in the nominal energy range of 5-25 MeV. Specifically, the task group recommended procedures for acquiring basic information required for acceptance testing and treatment planning of new accelerators with therapeutic electron beams. Since the publication of the TG-25 report, significant advances have taken place in the field of electron beam dosimetry, the most significant being that primary standards laboratories around the world have shifted from calibration standards based on exposure or air kerma to standards based on absorbed dose to water. The AAPM has published a new calibration protocol, TG-51, for the calibration of high-energy photon and electron beams. The formalism and dosimetry procedures recommended in this protocol are based on the absorbed dose to water calibration coefficient of an ionization chamber at 60Co energy, N60Co(D,w), together with the theoretical beam quality conversion coefficient k(Q) for the determination of absorbed dose to water in high-energy photon and electron beams. Task Group 70 was charged to reassess and update the recommendations in TG-25 to bring them into alignment with report TG-51 and to recommend new methodologies and procedures that would allow the practicing medical physicist to initiate and continue a high quality program in clinical electron beam dosimetry. This TG-70 report is a supplement to the TG-25 report and enhances the TG-25 report by including new topics and topics that were not covered in depth in the TG-25 report. These topics include procedures for obtaining data to commission a treatment planning computer, determining dose in irregularly shaped electron fields, and commissioning of sophisticated special procedures using high-energy electron beams. The use of

  18. Recommendations for clinical electron beam dosimetry: Supplement to the recommendations of Task Group 25

    SciTech Connect

    Gerbi, Bruce J.; Antolak, John A.; Deibel, F. Christopher; and others

    2009-07-15

    The goal of Task Group 25 (TG-25) of the Radiation Therapy Committee of the American Association of Physicists in Medicine (AAPM) was to provide a methodology and set of procedures for a medical physicist performing clinical electron beam dosimetry in the nominal energy range of 5-25 MeV. Specifically, the task group recommended procedures for acquiring basic information required for acceptance testing and treatment planning of new accelerators with therapeutic electron beams. Since the publication of the TG-25 report, significant advances have taken place in the field of electron beam dosimetry, the most significant being that primary standards laboratories around the world have shifted from calibration standards based on exposure or air kerma to standards based on absorbed dose to water. The AAPM has published a new calibration protocol, TG-51, for the calibration of high-energy photon and electron beams. The formalism and dosimetry procedures recommended in this protocol are based on the absorbed dose to water calibration coefficient of an ionization chamber at {sup 60}Co energy, N{sub D,w}{sup 60{sub C}{sub o}}, together with the theoretical beam quality conversion coefficient k{sub Q} for the determination of absorbed dose to water in high-energy photon and electron beams. Task Group 70 was charged to reassess and update the recommendations in TG-25 to bring them into alignment with report TG-51 and to recommend new methodologies and procedures that would allow the practicing medical physicist to initiate and continue a high quality program in clinical electron beam dosimetry. This TG-70 report is a supplement to the TG-25 report and enhances the TG-25 report by including new topics and topics that were not covered in depth in the TG-25 report. These topics include procedures for obtaining data to commission a treatment planning computer, determining dose in irregularly shaped electron fields, and commissioning of sophisticated special procedures using high

  19. Effects of Increasing Task Load on Memory Impairment in Adults with Down Syndrome

    ERIC Educational Resources Information Center

    Oliver, Chris; Holland, Tony; Hall, Scott; Crayton, Lissa

    2005-01-01

    The effect of increasing the number of stimuli to be recalled was investigated to evaluate whether sensitivity for memory impairment was enhanced in adults with Down syndrome when using higher task load. Three levels of load were compared across three groups of adults: those with cognitive deterioration, no cognitive deterioration over age 40, and…

  20. Effects of Solution Focused Therapy's "Formula First Session Task" on Compliance and Outcome in Family Therapy.

    ERIC Educational Resources Information Center

    Adams, Jerome F.; And Others

    1991-01-01

    Examined differential effects of formula first session task (FFST), FFST plus solution focused therapy, and standard problem focused structural-strategic intervention. At one week, FFST groups were significantly higher on measures of family compliance, clarity of treatment goals, and improvement in presenting problem. Found no significant…

  1. Learning New Grammatical Structures in Task-Based Language Learning: The Effects of Recasts and Prompts

    ERIC Educational Resources Information Center

    Van de Guchte, Marrit; Braaksma, Martine; Rijlaarsdam, Gert; Bimmel, Peter

    2015-01-01

    In the present study, we examine the effects of prompts and recasts on the acquisition of two new and different grammar structures in a task-based learning environment. Sixty-four 14-year-old 9th grade students (low intermediate) learning German as a foreign language were randomly assigned to three conditions: two experimental groups (one…

  2. The Effects of Authentic Tasks on Preservice Teachers' Attitudes towards Classes and Problem Solving Skills

    ERIC Educational Resources Information Center

    Kocyigit, Sinan; Zembat, Rengin

    2013-01-01

    This study aimed to investigate the effects of authentic tasks on preschool preservice teachers' attitudes towards the course and problem solving skills. The study was designed in accordance with the pretest-posttest control group model. The data were collected by using the "Problem Solving Skills Inventory", the "Course Attitude…

  3. Visual Feedback and Target Size Effects on Reach-to-Grasp Tasks in Children with Autism

    ERIC Educational Resources Information Center

    Yang, Hsiu-Ching; Lee, I-Chen; Lee, I-Ching

    2014-01-01

    This study explores the effects of visual condition and target size during four reach-to-grasp tasks between autistic children and healthy controls. Twenty children with autism and 20 healthy controls participated in the study. Qualisys motion capture system and kinematic measures were used to record movement. Autistic group showed significantly…

  4. Separating Cue Encoding from Target Processing in the Explicit Task-Cuing Procedure: Are There "True" Task Switch Effects?

    ERIC Educational Resources Information Center

    Arrington, Catherine M.; Logan, Gordon D.; Schneider, Darryl W.

    2007-01-01

    Six experiments were conducted to separate cue encoding from target processing in explicitly cued task switching to determine whether task switch effects could be separated from cue encoding effects and to determine the nature of the representations produced by cue encoding. Subjects were required to respond to the cue, indicating which cue was…

  5. Effect of Posthypnotic Dissociation on the Performance of Interfering Tasks

    ERIC Educational Resources Information Center

    Stevenson, James H.

    1976-01-01

    Builds upon earlier experiments in an attempt to measure the interferences between simultaneous tasks and the effects of hypnotic dissociation in increasing or decreasing this interference, thus testing the validity of one or the other of two theoretical models. (Author/RK)

  6. The Effects of Task Demands on Children's Metamemorial Decisions.

    ERIC Educational Resources Information Center

    Steuck, Kurt W.; Enright, Robert

    Using five metamemory question types and the Counting Span Test (CST), this research investigated the effects of metamemory task demands, and the relationship of the amount of information one can hold in working memory to metamemory question performance. One hundred twenty kindergarten, first, third, and fifth grade children served as subjects.…

  7. Experimental measurements of motion cue effects on STOL approach tasks

    NASA Technical Reports Server (NTRS)

    Ringland, R. F.; Stapleford, R. L.

    1972-01-01

    An experimental program to investigate the effects of motion cues on STOL approach is presented. The simulator used was the Six-Degrees-of-Freedom Motion Simulator (S.01) at Ames Research Center of NASA which has ?2.7 m travel longitudinally and laterally and ?2.5 m travel vertically. Three major experiments, characterized as tracking tasks, were conducted under fixed and moving base conditions: (1) A simulated IFR approach of the Augmentor Wing Jet STOL Research Aircraft (AWJSRA), (2) a simulated VFR task with the same aircraft, and (3) a single-axis task having only linear acceleration as the motion cue. Tracking performance was measured in terms of the variances of several motion variables, pilot vehicle describing functions, and pilot commentary.

  8. Facilitating Group Analysis of Two Case Studies Utilising Peer Tutoring: Comparison of Tasks and Outcomes

    ERIC Educational Resources Information Center

    Fong, Lin Siew

    2016-01-01

    Peer-tutoring sessions of two groups of advanced diploma in financial accounting students with mixed proficiency were analysed thoroughly in this study. Numerous studies in peer tutoring have produced favourable results to both tutors and tutees due to the scaffolding process which promotes effective learning. However, there is a lack of studies…

  9. Radiation dosimetry in digital breast tomosynthesis: Report of AAPM Tomosynthesis Subcommittee Task Group 223

    SciTech Connect

    Sechopoulos, Ioannis; Sabol, John M.; Berglund, Johan; Bolch, Wesley E.; Brateman, Libby; Christodoulou, Emmanuel; Goodsitt, Mitchell; Flynn, Michael; Geiser, William; Kyle Jones, A.; Lo, Joseph Y.; Paul Segars, W.; Maidment, Andrew D. A.; Nishino, Kazuyoshi; Nosratieh, Anita; and others

    2014-09-15

    The radiation dose involved in any medical imaging modality that uses ionizing radiation needs to be well understood by the medical physics and clinical community. This is especially true of screening modalities. Digital breast tomosynthesis (DBT) has recently been introduced into the clinic and is being used for screening for breast cancer in the general population. Therefore, it is important that the medical physics community have the required information to be able to understand, estimate, and communicate the radiation dose levels involved in breast tomosynthesis imaging. For this purpose, the American Association of Physicists in Medicine Task Group 223 on Dosimetry in Tomosynthesis Imaging has prepared this report that discusses dosimetry in breast imaging in general, and describes a methodology and provides the data necessary to estimate mean breast glandular dose from a tomosynthesis acquisition. In an effort to maximize familiarity with the procedures and data provided in this Report, the methodology to perform the dose estimation in DBT is based as much as possible on that used in mammography dose estimation.

  10. Teacher management behaviors and pupil task involvement during small group laboratory activities

    NASA Astrophysics Data System (ADS)

    Beasley, Warren

    A major concern of many beginning and experienced teachers is that of classroom management and control. This article describes recent research into defining classroom management procedures that are used by high school science teachers and their relationship to pupil ontaskness. The classroom is conceptualized as a manipulable behavioral system. This construct arises directly from Barker's (1968) ecological psychology, the classroom and its occupants being conceptualized as a behavior setting. The behaviors of the teacher and the pupils are an integral part of the unit (behavior setting), which in turn coerces certain behaviors from its participants. Thus settings, and, in particular, subsettings, are seen as more important determiners of social behavior than the personality of individual teacher or pupil. The methodology employed in this research has involved the extensive use of video in naturalistic science classrooms. Tapes of both teacher and pupil behaviors were continuously and independently recorded. Intensive analysis using electronic recording instruments interfaced with the computer has allowed the collection and sophisticated analysis of the observational data. Data relating to teacher management behavior in small group settings have been analyzed and the relationships to pupil task involvement have been explored.

  11. Distinguishing bias from sensitivity effects in multialternative detection tasks

    PubMed Central

    Sridharan, Devarajan; Steinmetz, Nicholas A.; Moore, Tirin; Knudsen, Eric I.

    2014-01-01

    Studies investigating the neural bases of cognitive phenomena increasingly employ multialternative detection tasks that seek to measure the ability to detect a target stimulus or changes in some target feature (e.g., orientation or direction of motion) that could occur at one of many locations. In such tasks, it is essential to distinguish the behavioral and neural correlates of enhanced perceptual sensitivity from those of increased bias for a particular location or choice (choice bias). However, making such a distinction is not possible with established approaches. We present a new signal detection model that decouples the behavioral effects of choice bias from those of perceptual sensitivity in multialternative (change) detection tasks. By formulating the perceptual decision in a multidimensional decision space, our model quantifies the respective contributions of bias and sensitivity to multialternative behavioral choices. With a combination of analytical and numerical approaches, we demonstrate an optimal, one-to-one mapping between model parameters and choice probabilities even for tasks involving arbitrarily large numbers of alternatives. We validated the model with published data from two ternary choice experiments: a target-detection experiment and a length-discrimination experiment. The results of this validation provided novel insights into perceptual processes (sensory noise and competitive interactions) that can accurately and parsimoniously account for observers' behavior in each task. The model will find important application in identifying and interpreting the effects of behavioral manipulations (e.g., cueing attention) or neural perturbations (e.g., stimulation or inactivation) in a variety of multialternative tasks of perception, attention, and decision-making. PMID:25146574

  12. Effects of spatially displaced feedback on remote manipulation tasks

    NASA Technical Reports Server (NTRS)

    Manahan, Meera K.; Stuart, Mark A.; Bierschwale, John M.; Hwang, Ellen Y.; Legendre, A. J.

    1992-01-01

    Several studies have been performed to determine the effects on computer and direct manipulation task performance when viewing conditions are spatially displaced. Whether results from these studies can be directly applied to remote manipulation tasks is quenstionable. The objective of this evaluation was to determine the effects of reversed, inverted, and inverted/reversed views on remote manipulation task performance using two 3-Degree of Freedom (DOF) hand controllers and a replica position hand controller. Results showed that trials using the inverted viewing condition showed the worst performance, followed by the inverted/reversed view and the reversed view when using the 2x3 DOF. However, these differences were not significant. The inverted and inverted/reversed viewing conditions were significantly worse than the normal and reversed viewing conditions when using the Kraft Replica. A second evaluation was conducted in which additional trials were performed with each viewing condition to determine the long term effects of spatially displaced views on task performance for the hand controllers. Results of the second evaluation indicated that there was more of a difference in performance between the perturbed viewing conditions and the normal viewing condition with the Kraft Replica than with the 2x3 DOF.

  13. Effect of Task-Centered Instructional Programs on Hypertensives' Ability to Achieve and Maintain Reduced Dietary Sodium Intake.

    ERIC Educational Resources Information Center

    Mann, Karen V.; Sullivan, Patricia L.

    This study sought to determine the effectiveness of systematically designed instructional programs in helping adult hypertensives to achieve and maintain dietary sodium intake. Sixty-six subjects were randomly allocated to one of three groups: task-centered instruction; task-centered instruction plus goal-setting and self-monitoring; or control.…

  14. The Effects of Task Fluency and Concurrent Reinforcement Schedules on Student Choice Allocation between Math Tasks

    ERIC Educational Resources Information Center

    Zaman, Maliha

    2010-01-01

    Students may avoid working on difficult tasks because it takes them longer to complete those tasks, which results in a delay to reinforcement. Research studies show that reinforcer and response dimensions can be manipulated within a concurrent operants framework to bias choice allocation toward more difficult tasks. The current study extends…

  15. Selecting Learning Tasks: Effects of Adaptation and Shared Control on Learning Efficiency and Task Involvement

    ERIC Educational Resources Information Center

    Corbalan, Gemma; Kester, Liesbeth; van Merrienboer, Jeroen J. G.

    2008-01-01

    Complex skill acquisition by performing authentic learning tasks is constrained by limited working memory capacity [Baddeley, A. D. (1992). Working memory. "Science, 255", 556-559]. To prevent cognitive overload, task difficulty and support of each newly selected learning task can be adapted to the learner's competence level and perceived task…

  16. Enhanced Bomb Effects for Obstacle Clearance (Analysis Task)

    DTIC Science & Technology

    1998-01-01

    Enhanced Bomb Effects for Obstacle Clearance (Analysis Task) Tim Hennessey Diane Nell Naval Surface Warfare Center, Indian Head Division 101 Strauss...need for a system capable of simultaneously breaching obstacles and clearing mines, in-stride, from over the horizon, during an amphibious assault...In response to the obstacle -breaching concern, the Enhanced Bomb Effects for Obstacle Clearance program was started. The purpose of the NSWCDD/CSS

  17. Effects of two tasks and two levels of difficulty upon surface electrogastrograms.

    PubMed

    Ercolani, M; Baldaro, B; Trombini, G

    1989-08-01

    The effects of differentiation, novelty, and difficulty of ability tasks upon electrogastrographic activity of healthy subjects during digestion were investigated. Electrical recording of activity of the stomach by means of surface electrodes was performed in 40 healthy volunteers before and after easy or hard tasks. 20 subjects had to complete puzzles; the others had mental arithmetic. Both groups were matched in terms of scores on easy and difficult tasks. Baseline recordings were performed before each trial. The number of waves with peak amplitude greater than 100 mu v on electrogastrographic recording during each time span was measured, using a visual analysis. There was a significant decrease in number of waves/min, during task performance. A more pronounced decrease was produced by subjects working on puzzles than those working on mental calculation and by subjects working on easy tasks than those working on difficult tasks when the easy preceded the difficult ones. A larger decrease was obtained when the tasks of comparable difficulty were performed first. Emotional correlates such as anger and irritability were suggested to play a role in the interpretation of results.

  18. Feel like you belong: on the bidirectional link between emotional fit and group identification in task groups

    PubMed Central

    Delvaux, Ellen; Meeussen, Loes; Mesquita, Batja

    2015-01-01

    Three studies investigated the association between members’ group identification and the emotional fit with their group. In the first study, a cross-sectional study in a large organization, we replicated earlier research by showing that group identification and emotional fit are positively associated, using a broader range of emotions and using profile correlations to measure group members’ emotional fit. In addition, in two longitudinal studies, where groups of students were followed at several time points during their collaboration on a project, we tested the directionality of the relationship between group identification and emotional fit. The results showed a bidirectional, positive link between group identification and emotional fit, such that group identification and emotional fit either mutually reinforce or mutually dampen each other over time. We discuss how these findings increase insights in group functioning and how they may be used to change group processes for better or worse. PMID:26300806

  19. Effects of disease severity and medication state on postural control asymmetry during challenging postural tasks in individuals with Parkinson's disease.

    PubMed

    Barbieri, Fabio A; Polastri, Paula F; Baptista, André M; Lirani-Silva, Ellen; Simieli, Lucas; Orcioli-Silva, Diego; Beretta, Victor S; Gobbi, Lilian T B

    2016-04-01

    The aim of this study was to investigate the effects of disease severity and medication state on postural control asymmetry during challenging tasks in individuals with Parkinson's disease (PD). Nineteen people with PD and 11 neurologically healthy individuals performed three standing task conditions: bipedal standing, tandem and unipedal adapted standing; the individuals with PD performed the tasks in ON and OFF medication state. The participants with PD were distributed into 2 groups according to disease severity: unilateral group (n=8) and bilateral group (n=11). The two PD groups performed the evaluations both under and without the medication. Two force plates were used to analyze the posture. The symmetric index was calculated for various of center of pressure. ANOVA one-way (groups) and two-way (PD groups×medication), with repeated measures for medication, were calculated. For main effects of group, the bilateral group was more asymmetric than CG. For main effects of medication, only unipedal adapted standing presented effects of PD medication. There was PD groups×medication interaction. Under the effects of medication, the unilateral group presented lower asymmetry of RMS in anterior-posterior direction and area than the bilateral group in unipedal adapted standing. In addition, the unilateral group presented lower asymmetry of mean velocity, RMS in anterior-posterior direction and area in unipedal standing and area in tandem adapted standing after a medication dose. Postural control asymmetry during challenging postural tasks was dependent on disease severity and medication state in people with PD. The bilateral group presented higher postural control asymmetry than the control and unilateral groups in challenging postural tasks. Finally, the medication dose was able to reduce postural control asymmetry in the unilateral group during challenging postural tasks.

  20. Effect of Group Sandtray Therapy with Preadolescents

    ERIC Educational Resources Information Center

    Flahive, Mon-hsin Wang; Ray, Dee

    2007-01-01

    The effectiveness of group sandtray therapy, a model of play therapy, was evaluated using a pretest-posttest control group design with 56 preadolescents exhibiting behavioral difficulties. The experimental group (n = 28) received sandtray therapy in small groups for 10 weeks while the wait-list control group (n = 28) received no treatment. Results…

  1. The Effects of Guided Imagery on Heart Rate Variability in Simulated Spaceflight Emergency Tasks Performers

    PubMed Central

    Yijing, Zhang; Xiaoping, Du; Fang, Liu; Xiaolu, Jing; Bin, Wu

    2015-01-01

    Objectives. The present study aimed to investigate the effects of guided imagery training on heart rate variability in individuals while performing spaceflight emergency tasks. Materials and Methods. Twenty-one student subjects were recruited for the experiment and randomly divided into two groups: imagery group (n = 11) and control group (n = 10). The imagery group received instructor-guided imagery (session 1) and self-guided imagery training (session 2) consecutively, while the control group only received conventional training. Electrocardiograms of the subjects were recorded during their performance of nine spaceflight emergency tasks after imagery training. Results. In both of the sessions, the root mean square of successive differences (RMSSD), the standard deviation of all normal NN (SDNN), the proportion of NN50 divided by the total number of NNs (PNN50), the very low frequency (VLF), the low frequency (LF), the high frequency (HF), and the total power (TP) in the imagery group were significantly higher than those in the control group. Moreover, LF/HF of the subjects after instructor-guided imagery training was lower than that after self-guided imagery training. Conclusions. Guided imagery was an effective regulator for HRV indices and could be a potential stress countermeasure in performing spaceflight tasks. PMID:26137491

  2. Categorization Method Affects the Typicality Effect: ERP Evidence from a Category-Inference Task

    PubMed Central

    Wang, Xiaoxi; Tao, Yun; Tempel, Tobias; Xu, Yuan; Li, Siqi; Tian, Yu; Li, Hong

    2016-01-01

    The typicality effect during categorization describes a phenomenon whereby typical items are more easily judged as members of a category than atypical items. Prior studies of the typicality effect have often used an inclusion task, which asks participants to assess whether an item belongs to a category. However, the correct exclusion of non-members is also an important component of effective categorization, which has yet to be directly investigated. Thus, the present study investigated how categorization method (inclusion vs. exclusion) modulates the typicality effect via behavioral and electrophysiological measures. Thirty-two participants (16 in the inclusion and 16 in the exclusion group) were shown six consecutive words that all shared one feature. Then, a seventh word was presented. The inclusion group judged whether the seventh word also possessed the feature, whereas the exclusion group judged whether the word did not possess the feature. The seventh word could be typical, atypical, or a nonmember of the category. Behavioral and event-related potential (ERP) data were collected. Behavioral results showed that the two groups did not differ in accuracy. However, typical items elicited shorter response times than atypical items, and this effect was more pronounced in the inclusion than the exclusion group. With regard to ERPs, interactions between item type and group were shown for the P2, N2, and N400 periods. Within the inclusion group, a typicality effect (indicated by a main effect of item type) was present in the P2 and N400 time windows, while the exclusion group elicited a typicality effect only in the N2 time window. These results provide electrophysiological evidence that an inclusion judgment task is more sensitive to category typicality than is an exclusion task. PMID:26925011

  3. The Effects of Multimedia Task-Based Language Teaching on EFL Learners' Oral L2 Production

    ERIC Educational Resources Information Center

    BavaHarji, Madhubala; Gheitanchian, Mehrnaz; Letchumanan, Krishnaveni

    2014-01-01

    This study examined the effects of tasks, with varying levels of complexity, i.e. simple, + complex and ++ complex tasks on EFL learners' oral production in a multimedia task-based language teaching environment. 57 EFL adult learners carried out a total of 12 tasks, in sets of four tasks within three different themes and different levels of…

  4. The Name-Letter-Effect in Groups: Sharing Initials with Group Members Increases the Quality of Group Work

    PubMed Central

    Polman, Evan; Pollmann, Monique M. H.; Poehlman, T. Andrew

    2013-01-01

    Although the name-letter-effect has been demonstrated reliably in choice contexts, recent research has called into question the existence of the name-letter-effect–the tendency among people to make choices that bear remarkable similarity with the letters in their own name. In this paper, we propose a connection between the name-letter-effect and interpersonal, group-level behavior that has not been previously captured in the literature. Specifically, we suggest that sharing initials with other group members promotes positive feelings toward those group members that in turn affect group outcomes. Using both field and laboratory studies, we found that sharing initials with group members cause groups to perform better by demonstrating greater performance, collective efficacy, adaptive conflict, and accuracy (on a hidden-profile task). Although many studies have investigated the effects of member similarity on various outcomes, our research demonstrates how minimal a degree of similarity among members is sufficient to influence quality of group outcomes. PMID:24236087

  5. Detection of Explanation Obstacles in Scientific Texts: The Effect of an Understanding Task vs. an Experiment Task

    ERIC Educational Resources Information Center

    Morgado, Júlia; Otero, José; Vaz-Rebelo, Piedade; Sanjosé, Vicente; Caldeira, Helena

    2014-01-01

    The aim of this study is to analyse the effect of tasks on the detection of explanation obstacles when secondary school students read scientific texts. Students were instructed to read short passages under different task conditions, and to ask questions if necessary. Obstacle detection was operationalised in terms of the type of questions asked by…

  6. Activities of the task group 8 on thin film PV module reliability (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Dhere, Neelkanth G.

    2016-09-01

    Photovoltaic (PV) modules and systems are being used increasingly to provide renewable energy to schools, residences, small businesses and utilities. At this time, the home owners and small businesses have considerable difficulty in detecting module and/or system degradation and especially enforcing warranty. It needs to be noted that IEC 61215-1 (test req.), -2 (test proc.) and -1-1 (c-Si) are forecasted to be circulated end of Feb 2016 and only editorial changes would be possible. 61215 series does include thin film technologies and would be replacing 61646. Moreover, IEC 61215-1, section 7.2 power output and electric circuitry does contain significant changes to acceptance criteria regarding rated label values, particularly rated power. Even though it is believed that consensus could be achieved within IEC TC82 WG2, some of the smaller players that do not participate actively in IEC TC82 - may not be surprised and must be informed. The other tech specific parts 61215-1-2 (CdTe), -1-3 (a-Si, µc-Si) and -1-4 (CIS, CIGS) are out for comments. The IEC closing date was January 29, 2016. The additions alternative damp heat (DH) test proposed Solar Frontier is being reviewed. In the past, only 600 V systems were permitted in the grid-connected residential and commercial systems in the US. The US commercial systems can now use higher voltage (1,000-1500V) in order to reduce BOS component costs. It is believed that there would not be any problems. The Task Group 8 is collecting data on higher voltage systems.

  7. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71

    SciTech Connect

    Gibbons, John P.; Antolak, John A.; Followill, David S.; Huq, M. Saiful; Klein, Eric E.; Lam, Kwok L.; Palta, Jatinder R.; Roback, Donald M.; Reid, Mark; Khan, Faiz M.

    2014-03-15

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D{sub 0}{sup ′}, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D{sub 0}{sup ′} = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D{sub 0}{sup ′} ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of d{sub m}, with D{sub 0}{sup ′} = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism.

  8. SU-E-T-273: Do Task Group External Beam QA Recommendations Guarantee Accurate Treatment Plan Dose Delivery?

    SciTech Connect

    Templeton, A; Liao, Y; Redler, G; Zhen, H

    2015-06-15

    Purpose: AAPM task groups 40/142 have provided an invaluable set of goals for physicists designing QA programs, attempting to standardize what would otherwise likely be a highly variable phenomenon across institutions. However, with the complexity of modalities such as VMAT, we hypothesize that following these guidelines to the letter might still allow unacceptable dose discrepancies. To explore this hypothesis we simulated machines bordering on QA acceptability, and calculated the effect on patient plans. Methods: Two errant machines were simulated in Aria/Eclipse, each just within task group criteria for output, percent depth dose, beam profile, gantry and collimator rotations, and jaw and MLC positions. One machine minimized dose to the PTV (machine A) and the other maximized dose to the OARs (machine B). Clinical treatment plans (3-phase prostate, n=3; hypofractionated lung, n=1) were calculated on these machines and the dose distributions compared. A prostate case was examined for contribution of error sources and evaluated using delivery QA data. Results: The prostate plans showed mean decreases in target D95 of 9.9% of prescription dose on machine A. On machine B, The rectal and bladder V70Gy each increased by 7.1 percentage points, while their V45Gy increased by 16.2% and 15.0% respectively. In the lung plan, the target D95 decreased by 12.8% and the bronchial tree Dmax increased by 21% of prescription dose, on machines A and B. One prostate plan showed target dose errors of 3.8% from MLC changes, 2% from output, ∼3% from energy and ∼0.5% from other factors. This plan achieved an 88.4% gamma passing rate using 3%/3mm using ArcCHECK. Conclusion: In the unlikely event that a machine exhibits all maximum errors allowed by TG 40/142, unacceptably large changes in dose delivered are possible especially in highly modulated VMAT plans, despite the machine passing routine QA.

  9. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71.

    PubMed

    Gibbons, John P; Antolak, John A; Followill, David S; Huq, M Saiful; Klein, Eric E; Lam, Kwok L; Palta, Jatinder R; Roback, Donald M; Reid, Mark; Khan, Faiz M

    2014-03-01

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D'0, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D'0 = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D'0 ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of dm, with D'0 = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism.

  10. Minimal intervention dentistry for managing dental caries - a review: report of a FDI task group.

    PubMed

    Frencken, Jo E; Peters, Mathilde C; Manton, David J; Leal, Soraya C; Gordan, Valeria V; Eden, Ece

    2012-10-01

    This publication describes the history of minimal intervention dentistry (MID) for managing dental caries and presents evidence for various carious lesion detection devices, for preventive measures, for restorative and non-restorative therapies as well as for repairing rather than replacing defective restorations. It is a follow-up to the FDI World Dental Federation publication on MID, of 2000. The dental profession currently is faced with an enormous task of how to manage the high burden of consequences of the caries process amongst the world population. If it is to manage carious lesion development and its progression, it should move away from the 'surgical' care approach and fully embrace the MID approach. The chance for MID to be successful is thought to be increased tremendously if dental caries is not considered an infectious but instead a behavioural disease with a bacterial component. Controlling the two main carious lesion development related behaviours, i.e. intake and frequency of fermentable sugars, to not more than five times daily and removing/disturbing dental plaque from all tooth surfaces using an effective fluoridated toothpaste twice daily, are the ingredients for reducing the burden of dental caries in many communities in the world. FDI's policy of reducing the need for restorative therapy by placing an even greater emphasis on caries prevention than is currently done, is therefore, worth pursuing.

  11. Effects of Aging on Arm Swing during Gait: The Role of Gait Speed and Dual Tasking.

    PubMed

    Mirelman, Anat; Bernad-Elazari, Hagar; Nobel, Tomer; Thaler, Avner; Peruzzi, Agnese; Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M

    2015-01-01

    Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30-77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3's (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30-40; 41-50; 51-60; 61-77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging.

  12. Locus of the intensity effect in simple reaction time tasks.

    PubMed

    Jaśkowski, Piotr; Kurczewska, Marta; Nowik, Agnieszka; van der Lubbe, Rob H J; Verleger, Rolf

    2007-11-01

    Evidence is still inconclusive regarding the locus of the stimulus intensity effect on information processing in reaction tasks. Miller, Ulrich, and Rinkenauer (1999) addressed this question by assessing the intensity effect on stimulus- and response-locked lateralized readiness potentials (LRPs) as indices of the sensory and motor parts of reaction time (RT). In the case of visual stimuli, they observed that application of brighter stimuli resulted in a shortening of RT and stimulus-locked LRP (S-LRP), but not of response-locked LRP (R-LRP). The results for auditory stimuli, however, were unclear. In spite of a clear RT reduction due to increased loudness, neither S-LRP nor R-LRP onset was affected. A reason for this failure might have been a relatively small range of intensity variation and the type of task. To check for this possibility, we performed three experiments in which broader ranges of stimulus intensities and simple, rather than choice, response tasks were used. Although the intensity effect on the R-LRP was negligible, S-LRP followed RT changes, irrespective of stimulus modality. These findings support the conclusion that stimulus intensity exerts its effect before the start of motoric processes. Finally, S-LRP and R-LRP findings are discussed within a broader information-processing perspective to check the validity of the claim that S-LRP and R-LRP can, indeed, be considered as pure estimates of the duration of sensory and motor processes.

  13. Sharing a task or sharing space? On the effect of the confederate in action coding in a detection task.

    PubMed

    Guagnano, Delia; Rusconi, Elena; Umiltà, Carlo Arrigo

    2010-03-01

    Several studies showed a Simon effect when two participants sit close to each other and perform one of the two halves of a two-choice RT task. That is, each participant perform a go-nogo task. A Simon effect emerges, which instead is absent when the same go-nogo tasks are performed individually. Hence the terms were introduced of "social Simon task" and 'social Simon effect". As of now, the social Simon effect was observed with social Simon tasks that overtly gave the participants the impression of being performing in collaboration with another person. In the present study we show that the social Simon effect was present also when, in the social Simon task, the two participants did not actually collaborate. It is, however, absent when participants perform the social task outside of each other's peripersonal space (i.e., outside arm-reach). We argue that the social Simon effect does not necessarily imply a representation of the other's action, as previously suggested. The presence of an active confederate in peripersonal space might simply provide a reference for coding one's own action in space.

  14. Carry-over effects of music in an isometric muscular endurance task.

    PubMed

    Crust, Lee

    2004-06-01

    This study tested the effects of exposure to self-selected motivational music both prior to and during performance of a muscular endurance task. 27 male undergraduate students in sports science completed an isometric weight-holding task on two separate occasions while listening either to self-selected motivational music or white noise. Participants were assigned to one of three groups on the basis of scores on a familiarization trial. The three groups were Prior Exposure, music or white noise played immediately before task commencement; Half Exposure, conditions initiated simultaneously with task commencement but terminated approximately half-way through the trial; and Full Exposure, conditions initiated simultaneously with trial commencement and continuing until voluntary cessation. A two-way mixed-model analysis of variance yielded a significant interaction and a main effect for condition. Participants held the weight suspended significantly longer when listening to music than with white noise. For the interaction, analysis of gain scores indicated participants' performance increased more for exposure to music during the entire session, than for exposure to music prior to the session. These results suggest that exposure to music during muscular endurance trials can yield significantly longer endurance times, but that exposure to music prior to task commencement may not carry over to influence performance.

  15. Effects of classroom bilingualism on task-shifting, verbal memory, and word learning in children.

    PubMed

    Kaushanskaya, Margarita; Gross, Megan; Buac, Milijana

    2014-07-01

    We examined the effects of classroom bilingual experience in children on an array of cognitive skills. Monolingual English-speaking children were compared with children who spoke English as the native language and who had been exposed to Spanish in the context of dual-immersion schooling for an average of 2 years. The groups were compared on a measure of non-linguistic task-shifting; measures of verbal short-term and working memory; and measures of word learning. The two groups of children did not differ on measures of non-linguistic task-shifting and verbal short-term memory. However, the classroom-exposure bilingual group outperformed the monolingual group on the measure of verbal working memory and a measure of word learning. Together, these findings indicate that while exposure to a second language in a classroom setting may not be sufficient to engender changes in cognitive control, it can facilitate verbal memory and verbal learning.

  16. Higher order balance control: Distinct effects between cognitive task and manual steadiness constraint on automatic postural responses.

    PubMed

    Coelho, Daniel Boari; Bourlinova, Catarina; Teixeira, Luis Augusto

    2016-12-01

    In the present experiment, we aimed to evaluate the interactive effect of performing a cognitive task simultaneously with a manual task requiring either high or low steadiness on APRs. Young volunteers performed the task of recovering upright balance following a mechanical perturbation provoked by unanticipatedly releasing a load pulling the participant's body backwards. The postural task was performed while holding a cylinder steadily on a tray. One group performed that task under high (cylinder' round side down) and another one under low (cylinder' flat side down) manual steadiness constraint. Those tasks were evaluated in the conditions of performing concurrently a cognitive numeric subtraction task and under no cognitive task. Analysis showed that performance of the cognitive task led to increased body and tray displacement, associated with higher displacement at the hip and upper trunk, and lower magnitude of activation of the GM muscle in response to the perturbation. Conversely, high manual steadiness constraint led to reduced tray velocity in association with lower values of trunk displacement, and decreased rotation amplitude at the ankle and hip joints. We found no interactions between the effects of the cognitive and manual tasks on APRs, suggesting that they were processed in parallel in the generation of responses for balance recovery. Modulation of postural responses from the manual and cognitive tasks indicates participation of higher order neural structures in the generation of APRs, with postural responses being affected by multiple mental processes occurring in parallel.

  17. Effects of Selected Task Performance Criteria at Initiating Adaptive Task Real locations

    NASA Technical Reports Server (NTRS)

    Montgomery, Demaris A.

    2001-01-01

    In the current report various performance assessment methods used to initiate mode transfers between manual control and automation for adaptive task reallocation were tested. Participants monitored two secondary tasks for critical events while actively controlling a process in a fictional system. One of the secondary monitoring tasks could be automated whenever operators' performance was below acceptable levels. Automation of the secondary task and transfer of the secondary task back to manual control were either human- or machine-initiated. Human-initiated transfers were based on the operator's assessment of the current task demands while machine-initiated transfers were based on the operators' performance. Different performance assessment methods were tested in two separate experiments.

  18. Dissociated backward priming effects in lexical decision and pronunciation tasks.

    PubMed

    Kahan, T A; Neely, J H; Forsythe, W J

    1999-03-01

    Backward priming was examined at 150- and 500-msec prime-target stimulus onset asynchronies (SOAs) using visually presented primes and targets in lexical decision and pronunciation tasks. Two kinds of backward relations were used: compound items for which targets and primes formed a word in the backward direction (e.g., prime: HOP; target: bell), and noncompound items for which targets and primes did not form a word but were associatively related in the backward but not the forward direction (e.g., prime: BABY; target: stork). Results showed that backward priming effects were equivalent for compounds and noncompounds. However, for lexical decisions, backward priming occurred at both SOAs, whereas for pronunciation, it occurred only at the 150-msec SOA. We discuss how this SOA-dissociated backward priming effect in lexical decision and pronunciation tasks poses a serious challenge for all theories of semantic priming.

  19. Shared Learning Shapes Human Performance: Transfer Effects in Task Sharing

    ERIC Educational Resources Information Center

    Milanese, Nadia; Iani, Cristina; Rubichi, Sandro

    2010-01-01

    We investigated whether performing a task with a co-actor shapes the way a subsequent task is performed. In four experiments participants were administered a Simon task after practicing a spatial compatibility task with an incompatible S-R mapping. In Experiment 1 they performed both tasks alongside another person; in Experiment 2 they performed…

  20. Effective Task Assignment and Motion Planning for Complex UAV Operations

    DTIC Science & Technology

    2011-09-01

    the eighth annual ACM symposium on Theory of computing , STOC ’76, ACM, New York, NY, USA, 1976, pp. 10–22. [15] Papadimitriou , C. H., “The Euclidean...AFRL-AFOSR-UK-TR-2011-0038 Effective Task Assignment and Motion Planning for Complex UAV Operations Tal Y. Shima...Planning for Complex UAV Operations 5a. CONTRACT NUMBER FA8655-09-1-3066 5b. GRANT NUMBER Grant 09-3066 5c. PROGRAM ELEMENT NUMBER 6

  1. Stimulus characteristics within directives: effects on accuracy of task completion.

    PubMed Central

    Richman, D M; Wacker, D P; Cooper-Brown, L J; Kayser, K; Crosland, K; Stephens, T J; Asmus, J

    2001-01-01

    Three experiments were conducted in an outpatient setting with young children who had been referred for treatment of noncompliant behavior and who had coexisting receptive language or receptive vocabulary difficulties. Experiment 1 studied differential responding of the participants to a brief hierarchical directive analysis (least-to-most complex stimulus prompts) to identify directives that functioned as discriminative stimuli for accurate responding. Experiment 1 identified distinct patterns of accurate responding relative to manipulation of directive stimulus characteristics. Experiment 2 demonstrated that directives identified as effective or ineffective in obtaining stimulus control of accurate responding during Experiment 1 continued to control accurate responding across play activities and academic tasks. Experiment 3 probed effects of the interaction between the type of directive (effective vs. ineffective) and the reinforcement contingency (differential reinforcement for attempts vs. differential reinforcement for accurate responses) on accurate task completion and disruptive behavior. Results suggested that behavioral escalation from inaccurate responding to disruptive behavior occurred only when ineffective directives were combined with differential reinforcement for accurate task completion. The overall results are discussed in terms of developing a methodology for identifying stimulus characteristics of directives that affect accurate responding. PMID:11678525

  2. Differential effects of white noise in cognitive and perceptual tasks.

    PubMed

    Herweg, Nora A; Bunzeck, Nico

    2015-01-01

    Beneficial effects of noise on higher cognition have recently attracted attention. Hypothesizing an involvement of the mesolimbic dopamine system and its functional interactions with cortical areas, the current study aimed to demonstrate a facilitation of dopamine-dependent attentional and mnemonic functions by externally applying white noise in five behavioral experiments including a total sample of 167 healthy human subjects. During working memory, acoustic white noise impaired accuracy when presented during the maintenance period (Experiments 1-3). In a reward based long-term memory task, white noise accelerated perceptual judgments for scene images during encoding but left subsequent recognition memory unaffected (Experiment 4). In a modified Posner task (Experiment 5), the benefit due to white noise in attentional orienting correlated weakly with reward dependence, a personality trait that has been associated with the dopaminergic system. These results suggest that white noise has no general effect on cognitive functions. Instead, they indicate differential effects on perception and cognition depending on a variety of factors such as task demands and timing of white noise presentation.

  3. Effects of caffeine on performance of low intensity tasks.

    PubMed

    Scott, William H; Coyne, Karen M; Johnson, Monique M; Lausted, Christopher G; Sahota, Manjit; Johnson, Arthur T

    2002-04-01

    31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit. Subjects were administered the beverage 30 min. prior to performing 12 separate tests assessing basic mathematics, simple response, logical reasoning, hand-eye coordination, and spatial and assembly skills. The Spielberger State Anxiety test was administered immediately after consuming the test beverage and once again at posttest. Analysis showed that caffeine did not significantly affect performance on all tests with the exception of the peripheral awareness (hand-eye coordination) test on which performance was higher after ingesting caffeine. The placebo treatment produced no effect on state anxiety, which contrasted with a significant rise in anxiety after caffeine consumption. State anxiety values were significantly greater after caffeine treatment relative to the placebo at pretest, and this difference persisted at posttest. These results demonstrated that the dose of caffeine increased scores on state anxiety for individuals who consumed less than three caffeinated beverages weekly but had very little effect on performance of low intensity tasks, except for a hand-eye coordination test involving peripheral awareness. Perhaps longer continuous performance of more demanding tasks would be more sensitive.

  4. Effects of virtual reality-based training and task-oriented training on balance performance in stroke patients

    PubMed Central

    Lee, Hyung Young; Kim, You Lim; Lee, Suk Min

    2015-01-01

    [Purpose] This study aimed to investigate the clinical effects of virtual reality-based training and task-oriented training on balance performance in stroke patients. [Subjects and Methods] The subjects were randomly allocated to 2 groups: virtual reality-based training group (n = 12) and task-oriented training group (n = 12). The patients in the virtual reality-based training group used the Nintendo Wii Fit Plus, which provided visual and auditory feedback as well as the movements that enabled shifting of weight to the right and left sides, for 30 min/day, 3 times/week for 6 weeks. The patients in the task-oriented training group practiced additional task-oriented programs for 30 min/day, 3 times/week for 6 weeks. Patients in both groups also underwent conventional physical therapy for 60 min/day, 5 times/week for 6 weeks. [Results] Balance and functional reach test outcomes were examined in both groups. The results showed that the static balance and functional reach test outcomes were significantly higher in the virtual reality-based training group than in the task-oriented training group. [Conclusion] This study suggested that virtual reality-based training might be a more feasible and suitable therapeutic intervention for dynamic balance in stroke patients compared to task-oriented training. PMID:26180341

  5. Effects of virtual reality-based training and task-oriented training on balance performance in stroke patients.

    PubMed

    Lee, Hyung Young; Kim, You Lim; Lee, Suk Min

    2015-06-01

    [Purpose] This study aimed to investigate the clinical effects of virtual reality-based training and task-oriented training on balance performance in stroke patients. [Subjects and Methods] The subjects were randomly allocated to 2 groups: virtual reality-based training group (n = 12) and task-oriented training group (n = 12). The patients in the virtual reality-based training group used the Nintendo Wii Fit Plus, which provided visual and auditory feedback as well as the movements that enabled shifting of weight to the right and left sides, for 30 min/day, 3 times/week for 6 weeks. The patients in the task-oriented training group practiced additional task-oriented programs for 30 min/day, 3 times/week for 6 weeks. Patients in both groups also underwent conventional physical therapy for 60 min/day, 5 times/week for 6 weeks. [Results] Balance and functional reach test outcomes were examined in both groups. The results showed that the static balance and functional reach test outcomes were significantly higher in the virtual reality-based training group than in the task-oriented training group. [Conclusion] This study suggested that virtual reality-based training might be a more feasible and suitable therapeutic intervention for dynamic balance in stroke patients compared to task-oriented training.

  6. JV Task 119 - Effects of Aging on Treated Activated Carbons

    SciTech Connect

    Edwin Olson; Lucinda Hamre; John Pavlish; Blaise Mibeck

    2009-03-25

    For both the United States and Canada, testing has been under way for electric utilities to find viable and economical mercury control strategies to meet pending future mercury emission limits. The technology that holds the most promise for mercury control in low-chlorine lignite to meet the needs of the Clean Air Act in the United States and the Canada-Wide Standards in Canada is injection of treated activated carbon (AC) into the flue gas stream. Most of the treated carbons are reported to be halogenated, often with bromine. Under a previous multiyear project headed by the Energy & Environmental Research Center (EERC), testing was performed on a slipstream unit using actual lignite-derived flue gas to evaluate various sorbent technologies for their effectiveness, performance, and cost. Testing under this project showed that halogenated ACs performed very well, with mercury capture rates often {ge} 90%. However, differences were noted between treated ACs with respect to reactivity and capacity, possibly as a result of storage conditions. Under certain conditions (primarily storage in ambient air), notable performance degradation had occurred in mercury capture efficiency. Therefore, a small exploratory task within this project evaluated possible differences resulting from storage conditions and subsequent effects of aging that might somehow alter their chemical or physical properties. In order to further investigate this potential degradation of treated (halogenated) ACs, the EERC, together with DOE's National Energy Technology Laboratory, the North Dakota Industrial Commission (NDIC), the Electric Power Research Institute (EPRI), SaskPower, and Otter Tail Power Company, assessed the aging effects of brominated ACs for the effect that different storage durations, temperatures, and humidity conditions have on the mercury sorption capacity of treated ACs. No aging effects on initial capture activity were observed for any carbons or conditions in the investigation

  7. Effects of multitasking on operator performance using computational and auditory tasks.

    PubMed

    Fasanya, Bankole K

    2016-09-01

    This study investigated the effects of multiple cognitive tasks on human performance. Twenty-four students at North Carolina A&T State University participated in the study. The primary task was auditory signal change perception and the secondary task was a computational task. Results showed that participants' performance in a single task was statistically significantly different from their performance in combined tasks: (a) algebra problems (algebra problem primary and auditory perception secondary); (b) auditory perception tasks (auditory perception primary and algebra problems secondary); and (c) mean false-alarm score in auditory perception (auditory detection primary and algebra problems secondary). Using signal detection theory (SDT), participants' performance measured in terms of sensitivity was calculated as -0.54 for combined tasks (algebra problems the primary task) and -0.53 auditory perceptions the primary task. During auditory perception tasks alone, SDT was found to be 2.51. Performance was 83% in a single task compared to 17% when combined tasks.

  8. Brief Report: Reduced Grouping Interference in Children with ASD--Evidence from a Multiple Object Tracking Task

    ERIC Educational Resources Information Center

    Evers, Kris; de-Wit, Lee; Van der Hallen, Ruth; Haesen, Birgitt; Steyaert, Jean; Noens, Ilse; Wagemans, Johan

    2014-01-01

    This study was inspired by the more locally oriented processing style in autism spectrum disorders (ASD). A modified multiple object tracking (MOT) task was administered to a group of children with and without ASD. Participants not only had to distinguish moving targets from distracters, but they also had to track targets when they were visually…

  9. Examining Preschoolers' Nutrition Knowledge Using a Meal Creation and Food Group Classification Task: Age and Gender Differences

    ERIC Educational Resources Information Center

    Holub, Shayla C.; Musher-Eizenman, Dara R.

    2010-01-01

    Eating behaviours begin to develop during early childhood, but relatively little is known about preschoolers' nutrition knowledge. The current study examined age and gender differences in this knowledge using two tasks: food group classification and the creation of unhealthy, healthy and preferred meals. Sixty-nine three- to six-year-old children…

  10. Texting and walking: effect of environmental setting and task prioritization on dual-task interference in healthy young adults.

    PubMed

    Plummer, Prudence; Apple, Sarah; Dowd, Colleen; Keith, Eliza

    2015-01-01

    Recent studies have shown that young adults significantly reduce their gait speed and weave more when texting while walking. Previous research has not examined the simultaneous dual-task effects on texting performance, therefore, the attention prioritization strategy used by young adults while texting and walking is not currently known. Moreover, it is not known whether laboratory-based studies accurately reflect texting and walking performance in the real world. This study compared dual-task interference during texting and walking between laboratory and real-world settings, and examined the ability of young adults to flexibly prioritize their attention between the two tasks in each environment. Texting and walking were assessed in single-task and three dual-task conditions (no-priority, gait-priority, texting-priority) in the lab and a University Student Center, in 32 healthy young adults. Dual-task effects on gait speed, texting speed, and texting accuracy were significant, but did not significantly differ between the two environments. Young adults were able to flexibly prioritize their attention between texting and walking, according to specific instruction, and this ability was not influenced by environmental setting. In the absence of instructions, young adults prioritized the texting task in the low-distraction environment, but displayed more equal focus between tasks in the real world. The finding that young adults do not significantly modify their texting and walking behavior in high-distraction environments lends weight to growing concerns about cell phone use and pedestrian safety.

  11. Ipsilateral coordination at preferred rate: effects of age, body side and task complexity.

    PubMed

    Van Impe, Annouchka; Coxon, James P; Goble, Daniel J; Wenderoth, Nici; Swinnen, Stephan Patrick

    2009-10-01

    Functional imaging studies have shown that elderly individuals activate widespread additional brain networks, compared to young subjects, when performing motor tasks. However, the parameters that effect this unique neural activation, including the spatial distribution of this activation across hemispheres, are still largely unknown. Here, we examined the effect of task complexity and body side on activation differences between older and younger adults while performing cyclical flexion-extension movements of the ipsilateral hand and foot. In particular, easy (isodirectional) and more difficult (non-isodirectional) coordination patterns were performed with either the left or right body side at a self-selected, comfortable rate. Even in the absence of imposed pacing the older group activated a larger brain network, suggestive of increased attentional deployment for monitoring the spatial relationships between the simultaneously moving segments and enhanced sensory processing and integration. Evidence of age-dependent underactivation was also found in contralateral M1, SMA and bilateral putamen, possibly reflecting a functional decline of the basal ganglia-mesial cortex pathway in the older group. An ANOVA model revealed significant main effects of task complexity and body side. However the interaction of these factors with age did not reach significance. Consequently, we conclude that under self-paced conditions, task complexity and body side did not have a modulatory effect on age-related brain activation.

  12. The Effect of Elicitation Task on Discourse Coherence and Cohesion in Adolescents with Brain Injury.

    ERIC Educational Resources Information Center

    Van Leer, Eva; Turkstra, Lyn

    1999-01-01

    Six adolescents with traumatic brain injury and six adolescents hospitalized for an illness not affecting the brain were administered two narrative tasks. Both groups produced significantly more coherent and cohesive narratives in a personal-event task than in a current-event task, and there was no significant difference between groups. (Author/CR)

  13. The Effect of Writing Task and Task Conditions on Colombian EFL Learners' Language Use

    ERIC Educational Resources Information Center

    McDonough, Kim; Fuentes, César García

    2015-01-01

    This classroom study examines whether English L2 writers' language use differs depending on the writing task (operationalized as paragraph type), and task conditions (operationalized as individual or collaborative writing). The texts written by English L2 university students in Colombia (N = 26) in response to problem/solution and cause/effect…

  14. Effect of Redundant Haptic Information on Task Performance during Visuo-Tactile Task Interruption and Recovery

    PubMed Central

    Moon, Hee-Seung; Baek, Jongsoo; Seo, Jiwon

    2016-01-01

    Previous studies have revealed that interruption induces disruptive influences on the performance of cognitive tasks. While much research has focused on the use of multimodal channels to reduce the cost of interruption, few studies have utilized haptic information as more than an associative cue. In the present study, we utilized a multimodal task interruption scenario involving the simultaneous presentation of visual information and haptic stimuli in order to investigate how the combined stimuli affect performance on the primary task (cost of interruption). Participants were asked to perform a two-back visuo-tactile task, in which visual and haptic stimuli were presented simultaneously, which was interrupted by a secondary task that also utilized visual and haptic stimuli. Four experimental conditions were evaluated: (1) paired information (visual stimulus + paired haptic stimulus) with interruption; (2) paired information without interruption; (3) non-paired information (visual stimulus + non-paired haptic stimulus) with interruption; and (4) non-paired information without interruption. Our findings indicate that, within a visuo-tactile task environment, redundant haptic information may not only increase accuracy on the primary task but also reduce the cost of interruption in terms of accuracy. These results suggest a new way of understanding the task recovery process within a multimodal environment. PMID:28008321

  15. Effect of Redundant Haptic Information on Task Performance during Visuo-Tactile Task Interruption and Recovery.

    PubMed

    Moon, Hee-Seung; Baek, Jongsoo; Seo, Jiwon

    2016-01-01

    Previous studies have revealed that interruption induces disruptive influences on the performance of cognitive tasks. While much research has focused on the use of multimodal channels to reduce the cost of interruption, few studies have utilized haptic information as more than an associative cue. In the present study, we utilized a multimodal task interruption scenario involving the simultaneous presentation of visual information and haptic stimuli in order to investigate how the combined stimuli affect performance on the primary task (cost of interruption). Participants were asked to perform a two-back visuo-tactile task, in which visual and haptic stimuli were presented simultaneously, which was interrupted by a secondary task that also utilized visual and haptic stimuli. Four experimental conditions were evaluated: (1) paired information (visual stimulus + paired haptic stimulus) with interruption; (2) paired information without interruption; (3) non-paired information (visual stimulus + non-paired haptic stimulus) with interruption; and (4) non-paired information without interruption. Our findings indicate that, within a visuo-tactile task environment, redundant haptic information may not only increase accuracy on the primary task but also reduce the cost of interruption in terms of accuracy. These results suggest a new way of understanding the task recovery process within a multimodal environment.

  16. The effects of a concurrent cognitive task on the postural control of young children with and without developmental coordination disorder.

    PubMed

    Laufer, Yocheved; Ashkenazi, Tal; Josman, Naomi

    2008-02-01

    The purpose of this study was to examine how dual-task performance affects the center of pressure (COP) sway characteristics and cognitive performance of children with developmental coordination disorder (DCD). Twenty-six children with DCD (mean age-5.1+/-0.59 years) and 20 typically developing children (mean age-5.0+/-0.57 years) participated in the study. The postural task consisted of standing quietly either on a firm or a compliant surface. The cognitive task involved naming simple objects appearing consecutively on a computer screen. Five tests were presented in random order, with the cognitive and the postural tasks tested either separately or concurrently. Mistakes in naming the objects were recorded, as were COP sway characteristics measured with a force-plate. Children with DCD demonstrated higher COP path-length velocity (PLV), and COP amplitude variability, as well as more mistakes in naming the objects in all stance conditions. A concurrent cognitive task increased all sway measures in both groups, with the effect on PLV greater in children with DCD. Cognitive performance was affected by dual tasking only in the control group. Young children with DCD demonstrated greater postural control activity than did the children in the control group during quiet stance, whether performed as a single or a dual task. This difference is accentuated during dual tasking when the children with DCD seem to prioritize the cognitive task.

  17. The effects of mirror therapy with tasks on upper extremity function and self-care in stroke patients

    PubMed Central

    Park, Youngju; Chang, Moonyoung; Kim, Kyeong-Mi; An, Duk-Hyun

    2015-01-01

    [Purpose] The purpose of this study was to determine the effects of mirror therapy with tasks on upper extremity unction and self-care in stroke patients. [Subjects] Thirty participants were randomly assigned to either an experimental group (n=15) or a control group (n=15). [Methods] Subjects in the experimental group received mirror therapy with tasks, and those in the control group received a sham therapy; both therapies were administered, five times per week for six weeks. The main outcome measures were the Manual Function Test for the paralyzed upper limb and the Functional Independence Measure for self-care performance. [Results] The experimental group had more significant gains in change scores compared with the control group after the intervention. [Conclusion] We consider mirror therapy with tasks to be an effective form of intervention for upper extremity function and self-care in stroke patients. PMID:26157249

  18. Dizocilpine (MK-801) impairs learning in the active place avoidance task but has no effect on the performance during task/context alternation.

    PubMed

    Vojtechova, Iveta; Petrasek, Tomas; Hatalova, Hana; Pistikova, Adela; Vales, Karel; Stuchlik, Ales

    2016-05-15

    The prevention of engram interference, pattern separation, flexibility, cognitive coordination and spatial navigation are usually studied separately at the behavioral level. Impairment in executive functions is often observed in patients suffering from schizophrenia. We have designed a protocol for assessing these functions all together as behavioral separation. This protocol is based on alternated or sequential training in two tasks testing different hippocampal functions (the Morris water maze and active place avoidance), and alternated or sequential training in two similar environments of the active place avoidance task. In Experiment 1, we tested, in adult rats, whether the performance in two different spatial tasks was affected by their order in sequential learning, or by their day-to-day alternation. In Experiment 2, rats learned to solve the active place avoidance task in two environments either alternately or sequentially. We found that rats are able to acquire both tasks and to discriminate both similar contexts without obvious problems regardless of the order or the alternation. We used two groups of rats, controls and a rat model of psychosis induced by a subchronic intraperitoneal application of 0.08mg/kg of dizocilpine (MK-801), a non-competitive antagonist of NMDA receptors. Dizocilpine had no selective effect on parallel/sequential learning of tasks/contexts. However, it caused hyperlocomotion and a significant deficit in learning in the active place avoidance task regardless of the task alternation. Cognitive coordination tested by this task is probably more sensitive to dizocilpine than spatial orientation because no hyperactivity or learning impairment was observed in the Morris water maze.

  19. Effects of age and gender on finger coordination in MVC and submaximal force-matching tasks.

    PubMed

    Shinohara, Minoru; Li, Sheng; Kang, Ning; Zatsiorsky, Vladimir M; Latash, Mark L

    2003-01-01

    The objective of the study is to examine the effects of age and gender on finger coordination. Twelve young (24 +/- 8 yr; 6 men and 6 women) and 12 elderly (75 +/- 5 yr; 6 men and 6 women) subjects performed single-finger maximal contraction [maximal voluntary contraction (MVC)], four-finger MVC, and four-finger ramp force production tasks by pressing on individual force transducers. A drop in the force of individual fingers during four-finger MVC tasks compared with single-finger MVC tasks (force deficit) was larger, whereas unintended force production by other fingers during single-finger MVC tasks (enslaving) was smaller, in elderly than in young subjects and in women than in men. Force deficit was smaller and enslaving was larger in subjects with higher peak force. During the ramp task, the difference between the variance of total force and the sum of variances of individual forces showed a logarithmic relation to the level of total force, across all subject groups. These findings suggest that indexes of finger coordination scale with force-generating capabilities across gender and age groups.

  20. Effect of aquatic dual-task training on balance and gait in stroke patients.

    PubMed

    Kim, Kyoung; Lee, Dong-Kyu; Kim, Eun-Kyung

    2016-07-01

    [Purpose] The purpose of this study was to determine the effect of aquatic dual-task training on balance and gait in stroke patients. [Subjects and Methods] Twenty stroke patients were divided into the experimental (n=10) and control (n=10) groups. Both groups underwent neurodevelopmental treatment. The experimental group additionally underwent aquatic dual-task training for 30 minutes a day, 5 days a week, for 6 weeks. Balance was measured using the Berg balance scale, Five Times Sit-to Stand Test, and Functional Reach Test. Gait was measured using the 10-Meter Walk Test, Timed Up and Go Test, and Functional Gait Assessment. [Results] For intragroup comparison, the experimental group showed a significant change after the experiment in all balance and gait assessment tests. For intergroup comparison, the experimental group showed relatively more significant change after the experiment in all balance and gait assessment tests. [Conclusion] Our results showed that aquatic dual-task training has a positive effect on balance and gait in stroke patients.

  1. Effect of aquatic dual-task training on balance and gait in stroke patients

    PubMed Central

    Kim, Kyoung; Lee, Dong-Kyu; Kim, Eun-Kyung

    2016-01-01

    [Purpose] The purpose of this study was to determine the effect of aquatic dual-task training on balance and gait in stroke patients. [Subjects and Methods] Twenty stroke patients were divided into the experimental (n=10) and control (n=10) groups. Both groups underwent neurodevelopmental treatment. The experimental group additionally underwent aquatic dual-task training for 30 minutes a day, 5 days a week, for 6 weeks. Balance was measured using the Berg balance scale, Five Times Sit-to Stand Test, and Functional Reach Test. Gait was measured using the 10-Meter Walk Test, Timed Up and Go Test, and Functional Gait Assessment. [Results] For intragroup comparison, the experimental group showed a significant change after the experiment in all balance and gait assessment tests. For intergroup comparison, the experimental group showed relatively more significant change after the experiment in all balance and gait assessment tests. [Conclusion] Our results showed that aquatic dual-task training has a positive effect on balance and gait in stroke patients. PMID:27512261

  2. Effects of Auditory Attention Training with the Dichotic Listening Task: Behavioural and Neurophysiological Evidence.

    PubMed

    Tallus, Jussi; Soveri, Anna; Hämäläinen, Heikki; Tuomainen, Jyrki; Laine, Matti

    2015-01-01

    Facilitation of general cognitive capacities such as executive functions through training has stirred considerable research interest during the last decade. Recently we demonstrated that training of auditory attention with forced attention dichotic listening not only facilitated that performance but also generalized to an untrained attentional task. In the present study, 13 participants underwent a 4-week dichotic listening training programme with instructions to report syllables presented to the left ear (FL training group). Another group (n = 13) was trained using the non-forced instruction, asked to report whichever syllable they heard the best (NF training group). The study aimed to replicate our previous behavioural results, and to explore the neurophysiological correlates of training through event-related brain potentials (ERPs). We partially replicated our previous behavioural training effects, as the FL training group tended to show more allocation of auditory spatial attention to the left ear in a standard dichotic listening task. ERP measures showed diminished N1 and enhanced P2 responses to dichotic stimuli after training in both groups, interpreted as improvement in early perceptual processing of the stimuli. Additionally, enhanced anterior N2 amplitudes were found after training, with relatively larger changes in the FL training group in the forced-left condition, suggesting improved top-down control on the trained task. These results show that top-down cognitive training can modulate the left-right allocation of auditory spatial attention, accompanied by a change in an evoked brain potential related to cognitive control.

  3. Effects of Auditory Attention Training with the Dichotic Listening Task: Behavioural and Neurophysiological Evidence

    PubMed Central

    Tallus, Jussi; Soveri, Anna; Hämäläinen, Heikki; Tuomainen, Jyrki; Laine, Matti

    2015-01-01

    Facilitation of general cognitive capacities such as executive functions through training has stirred considerable research interest during the last decade. Recently we demonstrated that training of auditory attention with forced attention dichotic listening not only facilitated that performance but also generalized to an untrained attentional task. In the present study, 13 participants underwent a 4-week dichotic listening training programme with instructions to report syllables presented to the left ear (FL training group). Another group (n = 13) was trained using the non-forced instruction, asked to report whichever syllable they heard the best (NF training group). The study aimed to replicate our previous behavioural results, and to explore the neurophysiological correlates of training through event-related brain potentials (ERPs). We partially replicated our previous behavioural training effects, as the FL training group tended to show more allocation of auditory spatial attention to the left ear in a standard dichotic listening task. ERP measures showed diminished N1 and enhanced P2 responses to dichotic stimuli after training in both groups, interpreted as improvement in early perceptual processing of the stimuli. Additionally, enhanced anterior N2 amplitudes were found after training, with relatively larger changes in the FL training group in the forced-left condition, suggesting improved top-down control on the trained task. These results show that top-down cognitive training can modulate the left-right allocation of auditory spatial attention, accompanied by a change in an evoked brain potential related to cognitive control. PMID:26439112

  4. A Summary of Taxonomies of Digital System Failure Modes Provided by the DigRel Task Group

    SciTech Connect

    Chu T. L.; Yue M.; Postma, W.

    2012-06-25

    Recently, the CSNI directed WGRisk to set up a task group called DIGREL to initiate a new task on developing a taxonomy of failure modes of digital components for the purposes of PSA. It is an important step towards standardized digital I&C reliability assessment techniques for PSA. The objective of this paper is to provide a comparison of the failure mode taxonomies provided by the participants. The failure modes are classified in terms of their levels of detail. Software and hardware failure modes are discussed separately.

  5. A Study of the Concurrent Validity of a Group Reasoning Test Built from Piaget's Tasks.

    ERIC Educational Resources Information Center

    Stefanich, Greg; And Others

    Researchers have attempted to develop paper and pencil Piagetian tests that yield results equivalent to manipulative Piagetian tasks and that can be administered in significantly less time. This study is an attempt to partially replicate and extend the findings of research by Paul Ankeny and Lyle Joyce who found significant positive correlations…

  6. Fairness, Teachers' Non-Task Behavior and Alumni Satisfaction: The Influence of Group Commitment

    ERIC Educational Resources Information Center

    de Lara, Pablo Zoghbi Manrique

    2008-01-01

    Purpose--The purpose of this study is to examine the relationship between interactional justice, as a type of organizational justice that reflects the teachers' perceived fairness of supervisor treatment, and their non-task behavior in terms of organizational citizenship behavior (OCB) and deviant workplace behavior (DWB).…

  7. Paradoxical effects of education on the Iowa Gambling Task.

    PubMed

    Evans, Cathryn E Y; Kemish, Karen; Turnbull, Oliver H

    2004-04-01

    Suitable normative information on the Iowa Gambling Task (IGT) is not currently available, though it is clear that there is great individual variability in performance on this assessment tool. Given that the task is presumed to measure the emotion-based learning systems that are thought to form the biological basis of 'intuition,' there is some reason to think that education (especially tertiary education) might explicitly de-emphasise the role of emotion-based learning in decision-making. This suggests the paradoxical finding that better-educated participants should show poorer performance on the IGT. We recruited 30 participants (all female, all aged 18-25) to participate in a 'real money' version of the IGT. There was no significant difference in performance in blocks 1-3 of the task (trials 1-60). However, there was a substantial effect of education on the final two blocks (trials 61-100), such that the less-well-educated participants produced twice as much of an improvement over baseline as did their university-educated colleagues. A range of possible explanations for this remarkable finding are discussed. The most likely appears to be that tertiary education specifically discourages the use of emotion-based learning systems in decision-making. These findings bear on the extent to which education has a role to play in our reliance on cognition and emotion in decision-making, including the likely role of education in the generation and maintenance of false beliefs.

  8. The Effect of Prior Concussion History on Dual-Task Gait following a Concussion.

    PubMed

    Howell, David R; Beasley, Michael; Vopat, Lisa; Meehan, William P

    2017-02-15

    Sustaining repeated concussions has been associated with worse outcomes after additional injuries. This effect has been identified using symptom inventories and neurocognitive tests; however, few investigations have examined how a prior concussion history affects gait soon after a subsequent concussion. We examined the gait characteristics of athletes with no documented concussion history (n = 31), athletes recovering from their first lifetime concussion (n = 15), and athletes recovering from their second or greater lifetime concussion (n = 22). All participants completed a single-task and dual-task gait examination, a medical history questionnaire, and a postconcussion symptom scale. Multivariate analyses of covariance (MANCOVA) models were used to evaluate mean gait differences among groups, and Spearman's ρ analyses were used to assess correlations between the number of lifetime concussions and gait characteristics. Patients reporting to the clinic with their second or greater lifetime concussion demonstrated smaller stride lengths than healthy control participants during dual-task walking (p = 0.01; d = 0.70). A moderate but insignificant correlation was detected between dual-task gait speed and the number of prior concussions (ρ = 0.41, p = 0.07). These results indicate that a cumulative effect of concussions across the lifetime may contribute to worsening dual-task dynamic motor function after concussion.

  9. Neural coupling between homologous muscles during bimanual tasks: effects of visual and somatosensory feedback.

    PubMed

    Nguyen, Hoi B; Lee, Sang Wook; Harris-Love, Michelle L; Lum, Peter S

    2017-02-01

    While the effects of sensory feedback on bimanual tasks have been studied extensively at two ends of the motor control hierarchy, the cortical and behavioral levels, much less is known about how it affects the intermediate levels, including neural control of homologous muscle groups. We investigated the effects of somatosensory input on the neural coupling between homologous arm muscles during bimanual tasks. Twelve subjects performed symmetric elbow flexion/extension tasks under different types of sensory feedback. The first two types involve visual feedback, with one imposing stricter force symmetry than the other. The third incorporated somatosensory feedback via a balancing apparatus that forced the two limbs to produce equal force levels. Although the force error did not differ between feedback conditions, the somatosensory feedback significantly increased temporal coupling of bilateral force production, indicated by a high correlation between left/right force profiles (P < 0.001). More importantly, intermuscular coherence between biceps brachii muscles was significantly higher with somatosensory feedback than others (P = 0.001). Coherence values also significantly differed between tasks (flexion/extension). Notably, whereas feedback type mainly modulated coherence in the α- and γ-bands, task type only affected β-band coherence. Similar feedback effects were observed for triceps brachii muscles, but there was also a strong phase effect on the coherence values (P < 0.001) that could have diluted feedback effects. These results suggest that somatosensory feedback can significantly increase neural coupling between homologous muscles. Additionally, the between-task difference in β-band coherence may reflect different neural control strategies for the elbow flexor and extensor muscles.

  10. Effect of handedness on the Stroop Colour Word Task.

    PubMed

    Beratis, Ion N; Rabavilas, Andreas; Papadimitriou, George N; Papageorgiou, Charalabos

    2010-11-01

    Handedness is associated with cerebral organisation, but its relationship with cognition remains unclear. Since the Stroop task is believed to measure aspects of executive control, this study aims to investigate the effect of handedness on Stroop interference. We used the Stroop task with 90 young adults with university education, of whom 47 (23 males) were right-handed and 43 (21 males) were left-handed. Main dependent variables were Stroop baseline (SB), Stroop incongruent (SI), and the proportional derivative Stroop reduction (SR) [SR=(SB - SI)/SB×100%] (Bugg, Delosh, Davalos, & Davis, 2007; Graf, Uttl, &Tuokko, 1995) scores. The analysis revealed that SI is significantly affected by both handedness and the interaction of sex×handedness, whereas SR is only affected by handedness. After controlling for the effect of SB on SI, only the effect of handedness remained statistically significant [F(1, 83) = 6.44, p=.013]. Post-hoc comparisons showed that left-handed females performed significantly better than right-handed females on both SI (p=.003) and SR (p=.007). The data suggest that handedness is associated with cognitive function alterations, which lead to a smaller Stroop interference of left-handers irrespectively of sex, an effect that is more pronounced in the female subpopulation.

  11. Age-related processing strategies and go–nogo effects in task-switching: an ERP study

    PubMed Central

    Gaál, Zsófia A.; Czigler, István

    2015-01-01

    We studied cognitive and age-related changes in three task-switching (TS) paradigms: (1) informatively cued TS with go stimuli, (2) informatively cued TS with go and nogo stimuli, (3) non-informatively cued TS with go and nogo stimuli. This design allowed a direct comparison, how informative and non-informative cues influenced preparatory processes, and how nogo stimuli changed the context of the paradigm and cognitive processing in different aging groups. Beside the behavioral measures [reaction time (RT), error rate], event-related potentials (ERPs) were registered to the cue and target stimuli in young (N = 39, mean age = 21.6 ± 1.6 years) and older (N = 40, mean age = 65.7 ± 3.2 years) adults. The results provide evidence for declining performance in the older group: they had slower RT, less hits, more erroneous responses, higher mixing costs and decreased amplitude of ERP components than the participants of the younger group. In the task without the nogo stimuli young adults kept the previous task-set active that could be seen in shorter RT and larger amplitude of cue-locked late positivity (P3b) in task repeat (TR) trials compared to task switch trials. If both go and nogo stimuli were presented, similar RTs and P3b amplitudes appeared in the TR and TS trials. In the complex task situations older adults did not evolve an appropriate task representation and task preparation, as indicated by the lack of cue-locked P3b, CNV, and target-locked P3b. We conclude that young participants developed explicit representation of task structures, but the presence of nogo stimuli had marked effects on such representation. On the other hand, older people used only implicit control strategy to solve the task, hence the basic difference between the age groups was their strategy of task execution. PMID:26029072

  12. Effects of transdermally administered nicotine on aspects of attention, task load, and mood in women and men.

    PubMed

    Trimmel, Michael; Wittberger, Susanne

    2004-07-01

    This double-blind placebo-controlled study was conducted to determine nicotine effects on diverse types of attentional performance, task load, and mood considering sex effects as suggested by animal studies. Twelve smokers, 12 deprived smokers and 12 nonsmokers (6 females, 6 males in each group) were investigated. Participants were treated either by 5 mg/16 h nicotine patches (Nicorette) or placebo. Effects of treatment were examined by a computerized attention-test battery; mood was assessed by the Berliner-Alltagssprachliches-Stimmungs-Inventar and task load by the NASA Task Load Index (NASA-TLX). Results showed that nicotine significantly increased the number of hits and decreased reaction time (RT) in the vigilance task. In the selective attention task combined with irrelevant speech as background noise, nicotine enhanced rate of hits. Although it was indicated that nicotine leads to a generally higher accuracy in attention tasks, response time of visual search was prolonged, contradicting a universal facilitation by nicotine. Participants experienced mental demand and temporal demand lower and rated alertness higher when in the nicotine condition. These effects were independent of smoking status, indicating "true" nicotine effects. Females took significant advantage of nicotine in the vigilance task, reaching the performance level of males, accompanied by a higher rated alertness. Results indicate task- and sex-dependent nicotine effects.

  13. Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults - A Pilot Study.

    PubMed

    Heinzel, Stephan; Rimpel, Jérôme; Stelzel, Christine; Rapp, Michael A

    2017-01-01

    Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60-72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality (p < 0.05) and the auditory modality (p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination.

  14. Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults – A Pilot Study

    PubMed Central

    Heinzel, Stephan; Rimpel, Jérôme; Stelzel, Christine; Rapp, Michael A.

    2017-01-01

    Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60–72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality (p < 0.05) and the auditory modality (p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination. PMID:28286477

  15. Differential Effects of Two T Group Styles

    ERIC Educational Resources Information Center

    Boller, Jon D.

    1974-01-01

    This article presents a rationale for examining the effects of the T group on introverts and extroverts. Results indicate that the sensory awareness group is more profitable to both personality types and that there is a direct relationship between personality type and profit in a T group. (Author)

  16. The Effects of Low Latency on Pointing and Steering Tasks.

    PubMed

    Friston, Sebastian; Karlström, Per; Steed, Anthony

    2016-05-01

    Latency is detrimental to interactive systems, especially pseudo-physical systems that emulate real-world behaviour. It prevents users from making quick corrections to their movement, and causes their experience to deviate from their expectations. Latency is a result of the processing and transport delays inherent in current computer systems. As such, while a number of studies have hypothesized that any latency will have a degrading effect, few have been able to test this for latencies less than ∼ 50 ms. In this study we investigate the effects of latency on pointing and steering tasks. We design an apparatus with a latency lower than typical interactive systems, using it to perform interaction tasks based on Fitts's law and the Steering law. We find evidence that latency begins to affect performance at ∼ 16 ms, and that the effect is non-linear. Further, we find latency does not affect the various components of an aiming motion equally. We propose a three stage characterisation of pointing movements with each stage affected independently by latency. We suggest that understanding how users execute movement is essential for studying latency at low levels, as high level metrics such as total movement time may be misleading.

  17. The Effects of Cognitive Task Complexity on L2 Oral Production

    ERIC Educational Resources Information Center

    Levkina, Mayya; Gilabert, Roger

    2012-01-01

    This paper examines the impact of task complexity on L2 production. The study increases task complexity by progressively removing pre-task planning time and increasing the number of elements. The combined effects of manipulating these two variables of task complexity simultaneously are also analyzed. Using a repeated measures design, 42…

  18. Stimulus-Category and Response-Repetition Effects in Task Switching: An Evaluation of Four Explanations

    ERIC Educational Resources Information Center

    Druey, Michel D.

    2014-01-01

    In many task-switch studies, task sequence and response sequence interact: Response repetitions produce benefits when the task repeats but produce costs when the task switches. Four different theoretical frameworks have been proposed to explain these effects: a reconfiguration-based account, association-learning models, an episodic-retrieval…

  19. [Side Effects of Occupational Group Therapy].

    PubMed

    Flöge, B; Fay, D; Jöbges, M; Linden, M; Muschalla, B

    2016-12-01

    Background: Occupational therapy is an important co-therapy in psychiatric therapy. It is a common belief that no risks are associated with occupational therapy. Negative effects caused by group therapy, especially occupational therapy, have not been in the focus of research yet. In this study we want to illustrate possible types and intensities of group side effects through occupational therapy. Patients and Methods: Patients of an inpatient rehabilitation facility filled out the Adverse Treatment Reaction Group Checklist. The checklist contains 47 items divided in six dimensions: group size, content, group participants, group outcome and global. The self-rating used a 5-point likert scale (0 = not at all; 4 = very much, extremely stressful) and gives information about types and intensities of the side effects. Results: 88.9 % of 45 patients reported negative effects of occupational group therapy. 28.9 % of the patients rated the side effect as at least severe. Discussion: Occupational therapy is associated with side effects as every other group therapy. Possible side effects caused by group therapy should be considered while planning and implementing occupational therapy.

  20. Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task

    PubMed Central

    Meinerz, Carolyn M.; Malloy, Philip; Geiser, Christopher F.; Kipp, Kristof

    2015-01-01

    Context  Continued research into the mechanism of noncontact anterior cruciate ligament injury helps to improve clinical interventions and injury-prevention strategies. A better understanding of the effects of anticipation on landing neuromechanics may benefit training interventions. Objective  To determine the effects of anticipation on lower extremity neuromechanics during a single-legged land-and-cut task. Design  Controlled laboratory study. Setting  University biomechanics laboratory. Participants  Eighteen female National Collegiate Athletic Association Division I collegiate soccer players (age = 19.7 ± 0.8 years, height = 167.3 ± 6.0 cm, mass = 66.1 ± 2.1 kg). Intervention(s)  Participants performed a single-legged land-and-cut task under anticipated and unanticipated conditions. Main Outcome Measure(s)  Three-dimensional initial contact angles, peak joint angles, and peak internal joint moments and peak vertical ground reaction forces and sagittal-plane energy absorption of the 3 lower extremity joints; muscle activation of selected hip- and knee-joint muscles. Results  Unanticipated cuts resulted in less knee flexion at initial contact and greater ankle toe-in displacement. Unanticipated cuts were also characterized by greater internal hip-abductor and external-rotator moments and smaller internal knee-extensor and external-rotator moments. Muscle-activation profiles during unanticipated cuts were associated with greater activation of the gluteus maximus during the precontact and landing phases. Conclusions  Performing a cutting task under unanticipated conditions changed lower extremity neuromechanics compared with anticipated conditions. Most of the observed changes in lower extremity neuromechanics indicated the adoption of a hip-focused strategy during the unanticipated condition. PMID:26285089

  1. Temporal stability and moderating effects of age and sex on CNTRaCS task performance.

    PubMed

    Strauss, Milton E; McLouth, Christopher J; Barch, Deanna M; Carter, Cameron S; Gold, James M; Luck, Steven J; MacDonald, Angus W; Ragland, J Daniel; Ranganath, Charan; Keane, Brian P; Silverstein, Steven M

    2014-07-01

    Research in schizophrenia has increasingly focused on incorporating measures from cognitive neuroscience, but little is known about their psychometric characteristics. Here, we extend prior research by reporting on temporal stability, as well as age and sex effects, for cognitive neuroscience paradigms optimized as part of the Cognitive Neuroscience Test Reliability and Clinical applications for Schizophrenia consortium. Ninety-nine outpatients with schizophrenia and 131 healthy controls performed 5 tasks assessing 4 constructs at 3 sessions. The constructs were (1) Goal maintenance (Dot Probe Expectancy [DPX] and AX continuous performance tasks [AX-CPT]); (2) Episodic memory (Relational and Item-Specific Encoding and Retrieval task [RiSE]); (3) Visual integration (Jittered Orientation Visual Integration task [JOVI]); and (4) Perceptual gain control (Contrast-Contrast Effect Task [CCE]). Patients performed worse than controls on all but the CCE, and the magnitude of these group differences was stable across sessions, with no sex differences observed. Improvements over sessions were seen for the AX-CPT, the DPX, and the JOVI though practice effects for the AX-CPT and the DPX were primarily present in older participants. For the AX-CPT and the JOVI, practice effects were larger for T1 to T2 than for T2 to T3. Age was associated with poor associative recognition on the RiSE and accuracy on the JOVI. Test-rest reliability ranged from poor for the JOVI threshold score to adequate to good for the DPX, AX-CPT, and JOVI accuracy measures, with RiSE and CCE measures in the moderate range. These results suggest that group differences in DPX, AX-CPT, RiSE, and JOVI are robust and consistent across repeated testing.

  2. Measuring Group Work Dynamics and Its Relation with L2 Learners' Task Motivation and Language Production

    ERIC Educational Resources Information Center

    Poupore, Glen

    2016-01-01

    While learners of a second language (L2) are increasingly interacting in small groups as part of a communicative methodological paradigm, very few studies have investigated the social dynamics that occur in such groups. The aim of this study is to introduce a group work dynamic measuring instrument and to investigate the relationship between group…

  3. The Effects of Task Structure on Time-sharing Efficiency and Resource Allocation Optimality

    NASA Technical Reports Server (NTRS)

    Tsang, P. S.; Wickens, C. D.

    1984-01-01

    A distinction was made between two aspects of time sharing performance: time sharing efficiency and attention allocation optimality. A secondary task technique was employed to evaluate the effects of the task structures of the component time shared tasks on both aspects of the time sharing performance. Five pairs of dual tasks differing in their structural configurations were investigated. The primary task was a visual/manual tracking task which requires spatial processing. The secondary task was either another tracking task or a verbal memory task with one of four different input/output configurations. Congruent to a common finding, time-sharing efficiency was observed to decrease with an increasing overlap of resources utilized by the time shared tasks. Research also tends to support the hypothesis that resource allocation is more optimal when the time shared tasks placed heavy demands on common processing resources than when they utilized separate resources.

  4. Reexamining the Validity and Reliability of the Clinical Version of the Iowa Gambling Task: Evidence from a Normal Subject Group

    PubMed Central

    Lin, Ching-Hung; Song, Tzu-Jiun; Chen, Ying-Ying; Lee, We-Kang; Chiu, Yao-Chu

    2013-01-01

    Over past decade, the Iowa gambling task (IGT) has been utilized to test various decision deficits induced by neurological damage or psychiatric disorders. The IGT has recently been standardized for identifying 13 different neuropsychological disorders. Neuropsychological patients choose bad decks frequently, and normal subjects prefer good expected value (EV) decks. However, the IGT has several validity and reliability problems. Some research groups have pointed out that the validity of IGT is influenced by the personality and emotional state of subjects. Additionally, several other studies have proposed that the “prominent deck B phenomenon” (PDB phenomenon) – that is, normal subjects preferring bad deck B – may be the most serious problem confronting IGT validity. Specifically, deck B offers a high frequency of gains but negative EV. In the standard IGT administration, choice behavior can be understood with reference to gain-loss frequency (GLF) rather than inferred future consequences (EV, the basic assumption of IGT). Furthermore, using two different criteria (basic assumption vs. professional norm) results in significantly different classification results. Therefore, we recruited 72 normal subjects to test the validity and reliability of IGT. Each subject performed three runs of the computer-based clinical IGT version. The PDB phenomenon has been observed to a significant degree in the first and second stages of the clinical IGT version. Obviously, validity, reliability, and the practice effect were unstable between two given stages. The present form of the clinical IGT version has only one stage, so its use should be reconsidered for examining normal decision makers; results from patient groups must also be interpreted with great care. GLF could be the main factor to be considered in establishing the constructional validity and reliability of the clinical IGT version. PMID:23755026

  5. Effects of varying task constraints on solutions to joint coordination in a sit-to-stand task.

    PubMed

    Scholz, J P; Reisman, D; Schöner, G

    2001-12-01

    The question of how multijoint movement is controlled can be studied by discovering how the variance of joint trajectories is structured in relation to important task-related variables. In a previous study of the sit-to-stand task, for instance, variations of body segment postures that leave the position of the body's center of mass (CM) unchanged were significantly greater than variations of body segment posture that varied the CM position. The present experiments tested the hypothesis that such structuring of joint configuration variability is accentuated when the mechanical or perceptual task demands are made more challenging. Six subjects performed the sit-to-stand task without vision (eyes closed), either on a normal or on a narrow support surface. An additional constraint on the postural task was introduced in a third condition by requiring subjects to maintain light touch (less than 1 N) with the fingertips while coming to a standing position on the narrow base of support. The joint configurations observed at each point in normalized time were analyzed with respect to trial-to-trial variability. The task variables CM and head position were used to define goal-equivalent sets of joint configurations ("uncontrolled manifolds," UCMs) within which variation of joint configuration leaves the task variables unchanged. The variability of joint configurations across trials was decomposed into components that did not affect (within the UCM) and that did affect (orthogonal to the UCM) the values of these task variables. Our results replicate the earlier finding of much larger variability in directions of joint space that leave the CM unchanged compared with directions that affect CM position. This effect was even more pronounced here than in the previous experiment, probably because of the more difficult perceptual conditions in the current study (eyes closed). When the mechanical difficulty of the task was increased, the difference between the two types of joint

  6. Attentional Focus Effects as a Function of Task Difficulty

    ERIC Educational Resources Information Center

    Wulf, Gabriele; Tollner, Thomas; Shea, Charles H.

    2007-01-01

    The purpose of the present study was to examine whether the advantages of adopting an external focus would be seen primarily for relatively challenging (postural stability) tasks but not less demanding tasks. To examine this, the authors used balance tasks that imposed increased challenges to maintaining stability. The present results support the…

  7. Effects of Task and Category Membership on Representation Stability

    ERIC Educational Resources Information Center

    Gaillard, Audrey; Urdapilleta, Isabel; Houix, Olivier; Manetta, Celine

    2011-01-01

    This study examined the within-subject stability of 150 participants who performed both a sorting task and a property-generation task over multiple sessions, focusing on three concrete concept categories (food, animals and bathroom products). We hypothesized that (1) the within-subject stability would be higher in the sorting task than in the…

  8. Effects of viewing distance on accommodative and pupillary responses following a three-dimensional task.

    PubMed

    Iwasaki, Tsuneto; Tawara, Akihiko

    2002-03-01

    We have investigated accommodation and pupil responses after viewing stereoscopic images related to the resting position of accommodation. After a 10-min visual task viewing stereoscopic three-dimensional images, measurements of dynamic accommodation and pupil response were made using an infrared optometer and a pupil analyser. Four conditions were given for the viewing distance: 0.4 m (closer than the subjects' resting position), 1 m (approximating to their resting state), and 1.5 and 3 m (farther than the resting position). For the 0.4- and 1-m groups, a delay in the accommodation response for near-to-far movement was shown after the task, from 817 to 1120 ms and from 830 to 898 ms, respectively, but there was no change in the pupillary response. In the 1.5- and 3-m groups, on the other hand, a significant delay in the accommodation response for far-to-near movement was shown, from 827 to 912 ms and from 857 to 1150 ms, respectively, and greater miosis was found, from 7.2 to 9.2 mm2 and from 8.0 to 10.4 mm2. The data reveal that there are different after-effects on accommodation and pupillary functions when subjects perform the task within their accommodative resting position, than when the task is performed outside the resting position.

  9. Indiana University High Energy Physics Group, Task C. Technical progress report, November 1, 1992--October 31, 1993

    SciTech Connect

    Bower, C.; Heinz, R.; Mufson, S.; Musser, J.

    1993-04-26

    The Indiana University Task C group is participating in the experiments GEM at the SSC and MACRO at the Gran Sasso. After an introduction to GEM in {paragraph}II, a detailed report is presented on the work done during the current contract period on the design of the outer region of the GEM Central Tracker. The Central Tracker Monte Carlo, which was the other significant GEM activity by the group, is included. In {paragraph}III is introduced MACRO and a brief status report is given. Muon Astronomy analysis done using MACRO data is also presented.

  10. Effects of dual tasking on the postural performance of people with and without multiple sclerosis: a pilot study.

    PubMed

    Jacobs, Jesse V; Kasser, Susan L

    2012-06-01

    People with multiple sclerosis (MS) exhibit both cognitive and postural impairments. This study examined the effects of MS and of dual tasking on postural performance, and explored associations among dual-task postural performance, cognitive capacity, fear of falling, and fatigue. Thirteen subjects with MS (Expanded Disability Status Scale: 0-4.5) and 13 matched subjects without MS performed three tasks of standing postural control, with and without dual tasking amid an auditory Stroop task: (1) step initiation, (2) forward leaning to the limits of stability, and (3) postural responses to rotations of the support surface. Two-factor general linear models were used to evaluate differences between the groups (with or without MS) and two conditions (single or dual tasking) for each postural task. During step initiation, dual tasking significantly delayed the onset of the anticipatory postural adjustment (APA) more for the subjects with MS than for those without MS, and step lengths increased for the subjects with MS but decreased for those without MS. No other significant group-by-condition interactions were evident on the recorded variables of stepping, leaning, postural responses, or Stroop-response accuracies and latencies. The scores for the subjects with MS on the Modified Fatigue Impact Scale significantly associated with the change between single-task to dual-task conditions in APA onset and foot-lift onset during step initiation as well as in lean position variability and lean onset times during forward leaning. The results suggest dual-task effects were more evident during step initiation and are associated with levels of fatigue for subjects with MS.

  11. The Influence of Randomly Allocated Group Membership when Developing Student Task Work and Team Work Capabilities

    ERIC Educational Resources Information Center

    McClelland, Giles Peter

    2012-01-01

    This study explores whether randomly assigning group membership enhances the student learning experience. The paper starts with a critical analysis of the approaches to student learning within higher education and how these approaches conflict with findings from applied psychology on group behaviour. The study adopts a serendipitous qualitative…

  12. Functions of an Adult Sickle Cell Group: Education, Task Orientation, and Support.

    ERIC Educational Resources Information Center

    Butler, Dennis J.; Beltran, Lou R.

    1993-01-01

    Reports on development of adult sickle cell support group and provides description of psychosocial factors most prevalent in patients' lives (anxiety about death, disruption of social support network, disability, dependence on pain medication, conflicts with health care providers). Notes that support group enhanced participants' knowledge about…

  13. An Exploration of Team Information Processing in a Dynamic Group Choice Task Involving Uncertainty

    DTIC Science & Technology

    1988-01-01

    computer-based aids in solving a complex int~rnational c:iaig problem. The system elicited a decision tree from the group based on pooled inputs from...Huber’s program model neems to provide a reasonable description of the group decision procens in the context of this ntudy CHUB26l3. Further, it seems

  14. Exploring the Effect of Red and Blue on Cognitive Task Performances

    PubMed Central

    Xia, Tiansheng; Song, Lu; Wang, Ting T.; Tan, Ling; Mo, Lei

    2016-01-01

    Previous studies on the effect of color on cognitive task performances and have led to two different views. Some researchers think that the influence of red and blue on cognitive tasks is modulated by the difficulty of the task, and other researchers suggest that the influence mainly depends on the type of task. The current study combined these factors to investigate the effect of color on cognitive task performance. In Experiment 1, we manipulated the difficulty of the task to investigate the effect of red and blue on detail-oriented task performance (the proofreading task), whereas in Experiment 2 we manipulated task difficulty to explore the effect of red and blue on creative task performance (the Remote Associates Test). The results showed that red enhanced the performance on a simple detail-oriented task. However, blue improved the performance on a difficult detail-oriented task as well as on both simple and difficult creative tasks. The results of the current study indicate that the type and difficulty of the task together modulate the effect of color on cognitive performances. PMID:27303343

  15. [The "Mining Rescue System and Mine Fires" Working Group. Tasks, results, future activities].

    PubMed

    Coenders, A

    1983-01-01

    The president of the working party presents details of its principal tasks in the past and in the present time. These can be summed up in a study of the problems mentioned below and the subsequent elaboration of recommendations for the benefit of the governments, guidelines, information reports and research proposals. The principal problems that were or are still under study are: --prevention of fires: shaft equipment, hydraulic fluids, belt conveyors, . . .; --detection of mine fires and spontaneous combustion; --fighting of mine fires: shaft fires, construction of stoppings, openings and recovering of fire zones, . . .; --coordination and rescue equipment: escape and rescue breathing apparatus, flameproof clothing, rescue of trapped miners; --stabilization of ventilation in the event of fire, . . . The speaker stresses the importance of the information exchange and the atmosphere of fellowship and solidarity that prevails in the working party.

  16. American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: quality assurance for clinical radiotherapy treatment planning.

    PubMed

    Fraass, B; Doppke, K; Hunt, M; Kutcher, G; Starkschall, G; Stern, R; Van Dyke, J

    1998-10-01

    In recent years, the sophistication and complexity of clinical treatment planning and treatment planning systems has increased significantly, particularly including three-dimensional (3D) treatment planning systems, and the use of conformal treatment planning and delivery techniques. This has led to the need for a comprehensive set of quality assurance (QA) guidelines that can be applied to clinical treatment planning. This document is the report of Task Group 53 of the Radiation Therapy Committee of the American Association of Physicists in Medicine. The purpose of this report is to guide and assist the clinical medical physicist in developing and implementing a comprehensive but viable program of quality assurance for modern radiotherapy treatment planning. The scope of the QA needs for treatment planning is quite broad, encompassing image-based definition of patient anatomy, 3D beam descriptions for complex beams including multileaf collimator apertures, 3D dose calculation algorithms, and complex plan evaluation tools including dose volume histograms. The Task Group recommends an organizational framework for the task of creating a QA program which is individualized to the needs of each institution and addresses the issues of acceptance testing, commissioning the planning system and planning process, routine quality assurance, and ongoing QA of the planning process. This report, while not prescribing specific QA tests, provides the framework and guidance to allow radiation oncology physicists to design comprehensive and practical treatment planning QA programs for their clinics.

  17. The Mozart effect on task performance in a laparoscopic surgical simulator.

    PubMed

    Wiseman, Michael C

    2013-10-01

    The Mozart Effect is a phenomenon whereby certain pieces of music induce temporary enhancement in "spatial temporal reasoning." To determine whether the Mozart Effect can improve surgical performance, 55 male volunteers (mean age = 20.6 years, range = 16-27), novice to surgery, were timed as they completed an activity course on a laparoscopic simulator. Subjects were then randomized for exposure to 1 of 2 musical pieces by Mozart (n = 21) and Dream Theater (n = 19), after which they repeated the course. Following a 15-minute exposure to a nonmusical piece, subjects were exposed to one of the pieces and performed the activity course a third time. An additional group (n = 15) that was not corandomized performed the tasks without any exposure to music. The percent improvements in completion time between 3 successive trials were calculated for each subject and group means compared. In 2 of the tasks, subjects exposed to the Dream Theater piece achieved approximately 30% more improvement (26.7 ± 8.3%) than those exposed to the Mozart piece (20.2 ± 7.8%, P = .021) or to no music (20.4 ± 9.1%, P = .049). Distinct patterns of covariance between baseline performance and subsequent improvement were observed for the different musical conditions and tasks. The data confirm the existence of a Mozart Effect and demonstrate for the first time its practical applicability. Prior exposure to certain pieces may enhance performance in practical skills requiring spatial temporal reasoning.

  18. Effective Communication in Adolescent Group Psychotherapy.

    ERIC Educational Resources Information Center

    Azima, Fern J.

    This paper defines a useful strategy for therapists working with adolescents which includes: (1) a general model of the group leader's responsibilities and (2) a cataloguing of some of the specific impediments for both adolescent peers and the therapist that prevent effective communication. The goal of the group therapy is to identify the specific…

  19. Disadvantageous associations: Reversible spatial cueing effects in a discrimination task

    PubMed Central

    Nico, Daniele; Daprati, Elena

    2015-01-01

    Current theories describe learning in terms of cognitive or associative mechanisms. To assess whether cognitive mechanisms interact with automaticity of associative processes we devised a shape-discrimination task in which participants received both explicit instructions and implicit information. Instructions further allowed for the inference that a first event would precede the target. Albeit irrelevant to respond, this event acted as response prime and implicit spatial cue (i.e. it predicted target location). To modulate cognitive involvement, in three experiments we manipulated modality and salience of the spatial cue. Results always showed evidence for a priming effect, confirming that the first stimulus was never ignored. More importantly, although participants failed to consciously recognize the association, responses to spatially cued trials became either slower or faster depending on salience of the first event. These findings provide an empirical demonstration that cognitive and associative learning mechanisms functionally co-exist and interact to regulate behaviour. PMID:26534830

  20. Framing of task performance strategies: effects on performance in a multiattribute dynamic decision making environment.

    PubMed

    Nygren, T E

    1997-09-01

    It is well documented that the way a static choice task is "framed" can dramatically alter choice behavior, often leading to observable preference reversals. This framing effect appears to result from perceived changes in the nature or location of a person's initial reference point, but it is not clear how framing effects might generalize to performance on dynamic decision making tasks that are characterized by high workload, time constraints, risk, or stress. A study was conducted to examine the hypothesis that framing can introduce affective components to the decision making process and can influence, either favorably (positive frame) or adversely (negative frame), the implementation and use of decision making strategies in dynamic high-workload environments. Results indicated that negative frame participants were significantly impaired in developing and employing a simple optimal decision strategy relative to a positive frame group. Discussion focuses on implications of these results for models of dynamic decision making.

  1. Testing Probability Matching and Episodic Retrieval Accounts of Response Repetition Effects in Task Switching

    ERIC Educational Resources Information Center

    Altmann, Erik M.

    2011-01-01

    This study takes inventory of available evidence on response repetition (RR) effects in task switching, in particular the evidence for RR cost when the task switches. The review reveals that relatively few task-switching studies in which RR effects were addressed have shown statistical support for RR cost, and that almost all are affected by 1 of…

  2. Simplifying the task of grouping fluid components in compositional reservoir simulation

    SciTech Connect

    Lomeland, F.; Harstad, O.

    1995-04-01

    The main results from a compositional reservoir simulation are the production rates. Normally, these are stable oil and dry gas streams, but other streams may also be reported. The detailed description of the fluid compositions can therefore be reduced to some extent if the overall description of the fluid properties is acceptable. This is achieved by lumping the components into component groups called pseudocomponents. This reduces the computation time and the needed memory. The traditional way to prepare a fluid model with pseudocomponents is to group them based on personal experience and parameter regression. This requires a lot of experience and continues practice, and probably represents one of the greatest obstacles for a reservoir engineer confronted with compositional reservoir simulation for the first time. This paper presents an automatic method of selecting pseudocomponents. The authors will compare the new method with other existing methods that automatically group components into pseudocomponents. The existing methods used in the comparison follow: (1) the method of mole-weighted average with components grouped to have approximately equal mole fraction; (2) the method of mass-weighted average with components grouped to have approximately equal mass fraction; (3) the method of Newly et al.

  3. From Loose Groups to Effective Teams: The Nine Key Factors of the Team Landscape.

    ERIC Educational Resources Information Center

    Sheard, A. G.; Kakabadse, A. P.

    2002-01-01

    A loose group of individuals working on a task differs from an effective team on nine factors: clearly defined goals, priorities, roles and responsibilities, self-awareness, leadership, group dynamics, communications, content, and infrastructure. Ways to eliminate barriers and speed formation of effective teams could be based on those factors.…

  4. IEC Quality Assurance Task Group 5: UV, Temperature, and Humidity (Presentation)

    SciTech Connect

    Miller, D.; Bath, J.; Köhl, M.; Shioda, T.

    2014-06-01

    Taskgroup 5 (TG5) is concerned with a comparative aging standard incorporating factors including ultraviolet radiation and temperature. Separate experiments are being conducted in support of a test standard via the regional sub-groups in Asia, Europe, and the United States. The authors will describe the objectives and timeline for TG5 as well as providing an update on the experiments in progress.

  5. Group Tasks, Activities, Dynamics, and Interactions in Collaborative Robotics Projects with Elementary and Middle School Children

    ERIC Educational Resources Information Center

    Yuen, Timothy T.; Boecking, Melanie; Stone, Jennifer; Tiger, Erin Price; Gomez, Alvaro; Guillen, Adrienne; Arreguin, Analisa

    2014-01-01

    Robotics provide the opportunity for students to bring their individual interests, perspectives and areas of expertise together in order to work collaboratively on real-world science, technology, engineering and mathematics (STEM) problems. This paper examines the nature of collaboration that manifests in groups of elementary and middle school…

  6. Teaching Chained Tasks to Students with Intellectual Disabilities by Using Video Prompting in Small Group Instruction

    ERIC Educational Resources Information Center

    Aykut, Çigil; Dagseven Emecen, Deniz; Dayi, Eylem; Karasu, Necdet

    2014-01-01

    Teaching students with intellectual disabilities in groups presents several difficulties. Use of technology can reduce some of these difficulties. The literature cites several examples of skill acquisition. The purpose of this study is to teach skills to students with intellectual disabilities by using video prompting. A multiple-probe design of…

  7. Friendship Group Identification, Multidimensional Self-Concept, and Experience of Developmental Tasks in Adolescence

    ERIC Educational Resources Information Center

    Tarrant, Mark; MacKenzie, Liam; Hewitt, Lisa A.

    2006-01-01

    This study applied a social identity perspective to the study of adolescent self-concept and social development. British adolescents aged 14-15 years (N=114) completed a questionnaire which asked them to: (i) rate their degree of identification with a school-based friendship group; (ii) complete a measure of multi-dimensional self-concept; and…

  8. The International Neuroblastoma Risk Group (INRG) Classification System: An INRG Task Force Report

    PubMed Central

    Cohn, Susan L.; Pearson, Andrew D.J.; London, Wendy B.; Monclair, Tom; Ambros, Peter F.; Brodeur, Garrett M.; Faldum, Andreas; Hero, Barbara; Iehara, Tomoko; Machin, David; Mosseri, Veronique; Simon, Thorsten; Garaventa, Alberto; Castel, Victoria; Matthay, Katherine K.

    2009-01-01

    Purpose Because current approaches to risk classification and treatment stratification for children with neuroblastoma (NB) vary greatly throughout the world, it is difficult to directly compare risk-based clinical trials. The International Neuroblastoma Risk Group (INRG) classification system was developed to establish a consensus approach for pretreatment risk stratification. Patients and Methods The statistical and clinical significance of 13 potential prognostic factors were analyzed in a cohort of 8,800 children diagnosed with NB between 1990 and 2002 from North America and Australia (Children's Oncology Group), Europe (International Society of Pediatric Oncology Europe Neuroblastoma Group and German Pediatric Oncology and Hematology Group), and Japan. Survival tree regression analyses using event-free survival (EFS) as the primary end point were performed to test the prognostic significance of the 13 factors. Results Stage, age, histologic category, grade of tumor differentiation, the status of the MYCN oncogene, chromosome 11q status, and DNA ploidy were the most highly statistically significant and clinically relevant factors. A new staging system (INRG Staging System) based on clinical criteria and tumor imaging was developed for the INRG Classification System. The optimal age cutoff was determined to be between 15 and 19 months, and 18 months was selected for the classification system. Sixteen pretreatment groups were defined on the basis of clinical criteria and statistically significantly different EFS of the cohort stratified by the INRG criteria. Patients with 5-year EFS more than 85%, more than 75% to ≤ 85%, ≥ 50% to ≤ 75%, or less than 50% were classified as very low risk, low risk, intermediate risk, or high risk, respectively. Conclusion By defining homogenous pretreatment patient cohorts, the INRG classification system will greatly facilitate the comparison of risk-based clinical trials conducted in different regions of the world and the

  9. Visual Cueing Effects Investigation for a Hovering Task

    NASA Technical Reports Server (NTRS)

    Chung, William W. Y.; Sweet, Barbara; Kaiser, Mary

    2003-01-01

    In simulators, as in actual aircraft, pilots conduct their missions according to perceived vehicle performance and spatial orientation from out-the-window (OTW) information. Ground-based flight simulations rely upon computer-generated OTW visual scenes. The realism and fidelity of a specific OTW simulation therefore has a significant impact on mission effectiveness. This study investigates effects of three visual parameters of the computer-generated image system (field-of-view, collimation, and resolution) on a disturbance-rejection hovering task. Pilots' performance and workload were studied under the following conditions: collimated optics vs. noncollimated optics, wide field-of-view (FOV) vs. narrow FOV, and higher resolution vs. lower resolution. Subjects were instructed to maintain a station-keeping position during disturbances while piloting an uncoupled four degrees-of-freedom (DOF) helicopter model, which had a satisfactory rate-command system in pitch and roll axes and ideal heading and altitude hold. Display collimation and FOV were found to have significant effects on pilots performance and subjective their subjective perception of visual cueing quality.

  10. Effects of Task Load, Task Speed and Cognitive Complexity on Satisfaction.

    DTIC Science & Technology

    1983-12-01

    Review of research and opinion. Pittsburgh: Psychological Service of Pittsburgh, 1957. Hoppock, R. Job satisfaction. New York: Harper & Rowe...37. Maslow, A. H. A theory of human motivation. Psychological Review , 1943, 50, 370-396. Mehrabian, A. and West, S. Emotional impact of a task... Psychology of men at work. Annual Review of Psychology , 1968, 1_9, 467-496. iA.V r -• r.«\\ 7* r-’.*.*>’• T-*T :?^^T^v:,•:•:•:• Sv:Si-yvvs-::..;.:ft

  11. Effects of task context and fluctuations of attention on neural activity supporting performance of the stroop task.

    PubMed

    West, R; Alain, C

    2000-08-04

    The influence of task context and transient fluctuations in attentional control on neural processes supporting performance of the Stroop task was investigated using event-related brain potentials. Task context was manipulated by varying the proportion of congruent and incongruent trials across different blocks of trials, and fluctuations of attentional control were considered by examining differences between trials eliciting faster and slower responses. The amplitudes of the N450, thought to reflect the suppression of a conceptual level processing system, and a temporo-parietal slow wave, thought to index the processing of color information, were greater when trials were mostly congruent in comparison to when trials were mostly incongruent. These findings indicate that the neural systems supporting inhibition and color processing are modulated by task demands. For the N450 the effect of task context interacted with the efficiency of attentional control being present for those trials eliciting faster responses and not for those trials eliciting slower responses. This finding is consistent with those from a growing number of studies indicating that the neural systems supporting attentional control are transient in nature, tending to fluctuate in efficiency over time.

  12. Effect of a concurrent auditory task on visual search performance in a driving-related image-flicker task.

    PubMed

    Richard, Christian M; Wright, Richard D; Ee, Cheryl; Prime, Steven L; Shimizu, Yujiro; Vavrik, John

    2002-01-01

    The effect of a concurrent auditory task on visual search was investigated using an image-flicker technique. Participants were undergraduate university students with normal or corrected-to-normal vision who searched for changes in images of driving scenes that involved either driving-related (e.g., traffic light) or driving-unrelated (e.g., mailbox) scene elements. The results indicated that response times were significantly slower if the search was accompanied by a concurrent auditory task. In addition, slower overall responses to scenes involving driving-unrelated changes suggest that the underlying process affected by the concurrent auditory task is strategic in nature. These results were interpreted in terms of their implications for using a cellular telephone while driving. Actual or potential applications of this research include the development of safer in-vehicle communication devices.

  13. The effect of feedback on performance in a fracture detection task

    NASA Astrophysics Data System (ADS)

    Donovan, Tim; Manning, David J.; Phillips, Peter W.; Higham, Stephen; Crawford, Trevor

    2005-04-01

    Four observer groups with different levels of expertise were tested to determine the effect of feedback on eye movements and accuracy whilst performing a simple radiological task. The observer groups were 8 experts, 9 year 1 radiography students, 9 year 3 radiography students, and 10 naive observers (psychology students). The task was fracture detection in the wrist. A test bank of 32 films was compiled with 14 normals, 6 grade 1 fractures (subtle appearance), 6 grade 2 fractures, and 6 grade 3 fractures (obvious appearance). Eye tracking was carried out on all observers to demonstrate differences in visual activity. Observers were asked to rate their confidence in their decision on a ten point scale. Feedback was presented to the observers in the form of circles displayed on the film where fixations had occurred, the size of which was proportional to the length of fixation. Observers were asked to repeat their decision rating. Accuracy was determined by ROC analysis and the area under the curve (AUC). In two groups, the novices and first year radiography students, the feedback resulted in no significant difference in the AUC. In the other two groups, experts (p = 0.002) and second year radiography students (p = 0.031), feedback had a negative effect on performance. The eye tracking parameters were measured for all subjects and compared. This is work in progress, but initial analysis of the data suggests that in a simple radiological task such as fracture detection, where search is very limited, feedback by encouraging observers to look harder at the image can have a negative effect on image interpretation performance, however for the novice feedback is beneficial as post feedback eye-tracking parameters measured more closely matched those of the experts.

  14. IEC Quality Assurance Task Group 5: UV, Temperature, and Humidity (Presentation)

    SciTech Connect

    Miller, D.; Bath, J.; Kohl, M.; Shioda, T.

    2014-03-01

    Taskgroup 5 (TG5) is concerned with a comparative aging standard incorporating factors including ultraviolet radiation, temperature, and humidity. Separate experiments are being conducted in support of a test standard via the regional sub-groups in Asia, Europe, and the United States. The authors will describe the objectives and timeline for TG5 as well as providing an update on the experiments in progress.

  15. Quality assurance of U.S.-guided external beam radiotherapy for prostate cancer: report of AAPM Task Group 154.

    PubMed

    Molloy, Janelle A; Chan, Gordon; Markovic, Alexander; McNeeley, Shawn; Pfeiffer, Doug; Salter, Bill; Tome, Wolfgang A

    2011-02-01

    Task Group 154 (TG154) of the American Association of Physicists in Medicine (AAPM) was created to produce a guidance document for clinical medical physicists describing recommended quality assurance (QA) procedures for ultrasound (U.S.)-guided external beam radiotherapy localization. This report describes the relevant literature, state of the art, and briefly summarizes U.S. imaging physics. Simulation, treatment planning and treatment delivery considerations are presented in order to improve consistency and accuracy. User training is emphasized in the report and recommendations regarding peer review are included. A set of thorough, yet practical, QA procedures, frequencies, and tolerances are recommended. These encompass recommendations to ensure both spatial accuracy and image quality.

  16. Global oral health inequalities: task group--implementation and delivery of oral health strategies.

    PubMed

    Sheiham, A; Alexander, D; Cohen, L; Marinho, V; Moysés, S; Petersen, P E; Spencer, J; Watt, R G; Weyant, R

    2011-05-01

    This paper reviews the shortcomings of present approaches to reduce oral diseases and inequalities, details the importance of social determinants, and links that to research needs and policies on implementation of strategies to reduce oral health inequalities. Inequalities in health are not narrowing. Attention is therefore being directed at determinants of major health conditions and the extent to which those common determinants vary within, between, and among groups, because if inequalities in health vary across groups, then so must underlying causes. Tackling inequalities in health requires strategies tailored to determinants and needs of each group along the social gradient. Approaches focusing mainly on downstream lifestyle and behavioral factors have limited success in reducing health inequalities. They fail to address social determinants, for changing people's behaviors requires changing their environment. There is a dearth of oral health research on social determinants that cause health-compromising behaviors and on risk factors common to some chronic diseases. The gap between what is known and implemented by other health disciplines and the dental fraternity needs addressing. To re-orient oral health research, practice, and policy toward a 'social determinants' model, a closer collaboration between and integration of dental and general health research is needed. Here, we suggest a research agenda that should lead to reductions in global inequalities in oral health.

  17. Effects of a Marathon Group Experience

    ERIC Educational Resources Information Center

    Treppa, Jerry A.; Fricke, Lawrence

    1972-01-01

    The present study examined the effects of a weekend marathon group experience on values of self-actualization and on the interpersonal dimnension of personality. Both experimental and control subjects showed significanly positive changes on posttest and follow-up scores. It was premature to believe that the positive effects of a marathon group…

  18. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71

    PubMed Central

    Gibbons, John P.; Antolak, John A.; Followill, David S.; Huq, M. Saiful; Klein, Eric E.; Lam, Kwok L.; Palta, Jatinder R.; Roback, Donald M.; Reid, Mark; Khan, Faiz M.

    2014-01-01

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$D_0^\\prime $\\end{document}D0′, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$D_0^\\prime $\\end{document}D0′ = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$D_0^\\prime $\\end{document}D0′ ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of dm, with

  19. A Metaanalysis of Perceptual Organization in Schizophrenia, Schizotypy, and Other High-Risk Groups Based on Variants of the Embedded Figures Task

    PubMed Central

    Panton, Kirsten R.; Badcock, David R.; Badcock, Johanna C.

    2016-01-01

    Current research on perceptual organization in schizophrenia frequently employs shapes with regularly sampled contours (fragmented stimuli), in noise fields composed of similar elements, to elicit visual abnormalities. However, perceptual organization is multi-factorial and, in earlier studies, continuous contours have also been employed in tasks assessing the ability to extract shapes from a background. We conducted a systematic review and meta-analysis of studies using closed-contour stimuli, including the Embedded Figures Test (EFT) and related tasks, both in people with schizophrenia and in healthy schizotypes and relatives, considered at increased risk for psychosis. Eleven studies met the selection criteria for inclusion in the meta-analysis, including six that used a between-groups study design (i.e., perceptual organization abilities of schizophrenia/high-risk groups were compared to healthy or clinical controls), and five that treated schizophrenia symptoms or schizotypy traits and indices of perceptual organization as continuous variables. Effect sizes and heterogeneity statistics were calculated, and the risk of publication bias was explored. A significant, moderate effect for EFT performance was found with studies that compared performance of schizophrenia/high-risk groups to a healthy or patient comparison group (d = −0.523, p < 0.001). However, significant heterogeneity was also found amongst the schizotypy, but not schizophrenia studies, as well as studies using accuracy, but not reaction time as a measure of performance. A non-significant correlation was found for the studies that examined schizophrenia symptoms or schizotypy traits as continuous variables (r = 0.012, p = 0.825). These results suggest that deficits in perceptual organization of non-fragmented stimuli are found when differences between schizophrenia/high-risk groups and comparison groups are maximized. These findings should motivate further investigation of perceptual organization

  20. Dissociation between arithmetic relatedness and distance effects is modulated by task properties: an ERP study comparing explicit vs. implicit arithmetic processing.

    PubMed

    Avancini, Chiara; Galfano, Giovanni; Szűcs, Dénes

    2014-12-01

    Event-related potential (ERP) studies have detected several characteristic consecutive amplitude modulations in both implicit and explicit mental arithmetic tasks. Implicit tasks typically focused on the arithmetic relatedness effect (in which performance is affected by semantic associations between numbers) while explicit tasks focused on the distance effect (in which performance is affected by the numerical difference of to-be-compared numbers). Both task types elicit morphologically similar ERP waves which were explained in functionally similar terms. However, to date, the relationship between these tasks has not been investigated explicitly and systematically. In order to fill this gap, here we examined whether ERP effects and their underlying cognitive processes in implicit and explicit mental arithmetic tasks differ from each other. The same group of participants performed both an implicit number-matching task (in which arithmetic knowledge is task-irrelevant) and an explicit arithmetic-verification task (in which arithmetic knowledge is task-relevant). 129-channel ERP data differed substantially between tasks. In the number-matching task, the arithmetic relatedness effect appeared as a negativity over left-frontal electrodes whereas the distance effect was more prominent over right centro-parietal electrodes. In the verification task, all probe types elicited similar N2b waves over right fronto-central electrodes and typical centro-parietal N400 effects over central electrodes. The distance effect appeared as an early-rising, long-lasting left parietal negativity. We suggest that ERP effects in the implicit task reflect access to semantic memory networks and to magnitude discrimination, respectively. In contrast, effects of expectation violation are more prominent in explicit tasks and may mask more delicate cognitive processes.

  1. Influence of background noise on the performance in the odor sensitivity task: effects of noise type and extraversion.

    PubMed

    Seo, Han-Seok; Hähner, Antje; Gudziol, Volker; Scheibe, Mandy; Hummel, Thomas

    2012-10-01

    Recent research demonstrated that background noise relative to silence impaired subjects' performance in a cognitively driven odor discrimination test. The current study aimed to investigate whether the background noise can also modulate performance in an odor sensitivity task that is less cognitively loaded. Previous studies have shown that the effect of background noise on task performance can be different in relation to degree of extraversion and/or type of noise. Accordingly, we wanted to examine whether the influence of background noise on the odor sensitivity task can be altered as a function of the type of background noise (i.e., nonverbal vs. verbal noise) and the degree of extraversion (i.e., introvert vs. extrovert group). Subjects were asked to conduct an odor sensitivity task in the presence of either nonverbal noise (e.g., party sound) or verbal noise (e.g., audio book), or silence. Overall, the subjects' mean performance in the odor sensitivity task was not significantly different across three auditory conditions. However, with regard to the odor sensitivity task, a significant interaction emerged between the type of background noise and the degree of extraversion. Specifically, verbal noise relative to silence significantly impaired or improved the performance of the odor sensitivity task in the introvert or extrovert group, respectively; the differential effect of introversion/extraversion was not observed in the nonverbal noise-induced task performance. In conclusion, our findings provide new empirical evidence that type of background noise and degree of extraversion play an important role in modulating the effect of background noise on subjects' performance in an odor sensitivity task.

  2. Paradoxical Effects of Education on the Iowa Gambling Task

    ERIC Educational Resources Information Center

    Evans, Cathryn E.Y.; Kemish, Karen; Turnbull, Oliver H.

    2004-01-01

    Suitable normative information on the Iowa Gambling Task (IGT) is not currently available, though it is clear that there is great individual variability in performance on this assessment tool. Given that the task is presumed to measure the emotion-based learning systems that are thought to form the biological basis of "intuition," there is some…

  3. Interference effects of vocalization on dual task performance

    NASA Astrophysics Data System (ADS)

    Owens, J. M.; Goodman, L. S.; Pianka, M. J.

    1984-09-01

    Voice command and control systems have been proposed as a potential means of off-loading the typically overburdened visual information processing system. However, prior to introducing novel human-machine interfacing technologies in high workload environments, consideration must be given to the integration of the new technologists within existing task structures to ensure that no new sources of workload or interference are systematically introduced. This study examined the use of voice interactive systems technology in the joint performance of two cognitive information processing tasks requiring continuous memory and choice reaction wherein a basis for intertask interference might be expected. Stimuli for the continuous memory task were presented aurally and either voice or keyboard responding was required in the choice reaction task. Performance was significantly degraded in each task when voice responding was required in the choice reaction time task. Performance degradation was evident in higher error scores for both the choice reaction and continuous memory tasks. Performance decrements observed under conditions of high intertask stimulus similarity were not statistically significant. The results signal the need to consider further the task requirements for verbal short-term memory when applying speech technology in multitask environments.

  4. Effects of a Coactor's Focus of Attention on Task Performance

    ERIC Educational Resources Information Center

    Bockler, Anne; Knoblich, Gunther; Sebanz, Natalie

    2012-01-01

    Coactors take into account certain aspects of each other's tasks even when this is not required to perform their own task. The present experiments investigated whether the way a coactor allocates attention affects one's own attentional relation to stimuli that are attended jointly (Experiment 1), individually (Experiment 2), or in parallel…

  5. The management of imaging dose during image-guided radiotherapy: Report of the AAPM Task Group 75

    SciTech Connect

    Murphy, Martin J.; Balter, James; Balter, Stephen; BenComo, Jose A. Jr.; Das, Indra J.; Jiang, Steve B.; Ma, C.-M.; Olivera, Gustavo H.; Rodebaugh, Raymond F.; Ruchala, Kenneth J.; Shirato, Hiroki; Yin, Fang-Fang

    2007-10-15

    Radiographic image guidance has emerged as the new paradigm for patient positioning, target localization, and external beam alignment in radiotherapy. Although widely varied in modality and method, all radiographic guidance techniques have one thing in common--they can give a significant radiation dose to the patient. As with all medical uses of ionizing radiation, the general view is that this exposure should be carefully managed. The philosophy for dose management adopted by the diagnostic imaging community is summarized by the acronym ALARA, i.e., as low as reasonably achievable. But unlike the general situation with diagnostic imaging and image-guided surgery, image-guided radiotherapy (IGRT) adds the imaging dose to an already high level of therapeutic radiation. There is furthermore an interplay between increased imaging and improved therapeutic dose conformity that suggests the possibility of optimizing rather than simply minimizing the imaging dose. For this reason, the management of imaging dose during radiotherapy is a different problem than its management during routine diagnostic or image-guided surgical procedures. The imaging dose received as part of a radiotherapy treatment has long been regarded as negligible and thus has been quantified in a fairly loose manner. On the other hand, radiation oncologists examine the therapy dose distribution in minute detail. The introduction of more intensive imaging procedures for IGRT now obligates the clinician to evaluate therapeutic and imaging doses in a more balanced manner. This task group is charged with addressing the issue of radiation dose delivered via image guidance techniques during radiotherapy. The group has developed this charge into three objectives: (1) Compile an overview of image-guidance techniques and their associated radiation dose levels, to provide the clinician using a particular set of image guidance techniques with enough data to estimate the total diagnostic dose for a specific

  6. A Partition of Group Performance into Informational and Social Components in a Hypothesis Generation Task.

    DTIC Science & Technology

    1980-08-03

    INSTRUCTIONSREPOT DCUMETATON PGE EFORE COMPLETING FORMA ORT NMBER 2. GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMSER /t R-8-3-89’ 4 s ~6 ~ / 4. TITLIE (an&.biiti.J...as follows: Social interaction = P i(a U b) - P (a U b) = P (a n b) - P i(a n b), (2) where the subscripts s and i denote synthetic and interactive...for further discussion of this paradigm. The principle manipulation was a comparison of subjects working alone to subjects working in groups of four. In

  7. The effect of childhood bilingualism on episodic and semantic memory tasks.

    PubMed

    Kormi-Nouri, Reza; Shojaei, Razie-Sadat; Moniri, Sadegheh; Gholami, Ali-Reza; Moradi, Ali-Reza; Akbari-Zardkhaneh, Saeed; Nilsson, Lars-Göran

    2008-04-01

    Kormi-Nouri, Moniri and Nilsson (2003) demonstrated that Swedish-Persian bilingual children recalled at a higher level than Swedish monolingual children, when they were tested using Swedish materials. The present study was designed to examine the bilingual advantage of children who use different languages in their everyday life but have the same cultural background and live in their communities in the same way as monolingual children. In four experiments, 488 monolingual and bilingual children were compared with regard to episodic and semantic memory tasks. In experiments 1 and 2 there were 144 boys and 144 girls in three school groups (aged 9-10 years, 13-14 years and 16-17 years) and in three language groups (Persian monolingual, Turkish-Persian bilingual, and Kurdish-Persian bilingual). In experiments 3 and 4, there were 200 male students in two school groups (aged 9-10 years and 16-17 years) and in two language groups (Persian monolingual and Turkish-Persian bilingual). In the episodic memory task, children learned sentences (experiments 1-3) and words (Experiment 4). Letter and category fluency tests were used as measures of semantic memory. To change cognitive demands in memory tasks, in Experiment 1, the integration of nouns and verbs within sentences was manipulated by the level of association between verb and noun in each sentence. At retrieval, a recognition test was used. In experiments 2 and 3, the organization between sentences was manipulated at encoding in Experiment 2 and at both encoding and retrieval in Experiment 3 through the use of categories among the objects. At retrieval, free recall or cued recall tests were employed. In Experiment 4, the bilingual children were tested with regard to both their first and their second language. In all four experiments, a positive effect of bilingualism was found on episodic and semantic memory tasks; the effect was more pronounced for older than younger children. The bilingual advantage was not affected by

  8. The Effects of Mastery Training and Explicit Feedback on Task Design Preference in a Vocational Setting.

    ERIC Educational Resources Information Center

    Lee, David L.; Belfiore, Phillip J.; Toro-Zambrana, Wanda

    2001-01-01

    A study examined the effects of mastery training and explicit feedback on the selection behavior of two adults with severe mental retardation across two different vocational task designs. Selection behavior was affected by task efficiency only when efficiency was made more salient by pairing task cues with work incentives. (Contains references.)…

  9. Piagetian Formal Operational Tasks: A Crossover Study of Learning Effect and Reliability

    ERIC Educational Resources Information Center

    Lawson, Anton E.; And Others

    1974-01-01

    The general purposes of this study were to analyze responses on five Piagetian formal operational tasks in a test-retest situation to determine the extent to which taking a pretest effected scores on posttests and to determine task and examiner reliabilities. Significant test score gains on Piagetian tasks appeared to result from test-retest…

  10. Effects of Tasks on Spoken Interaction and Motivation in English Language Learners

    ERIC Educational Resources Information Center

    Carrero Pérez, Nubia Patricia

    2016-01-01

    Task based learning (TBL) or Task based learning and teaching (TBLT) is a communicative approach widely applied in settings where English has been taught as a foreign language (EFL). It has been documented as greatly useful to improve learners' communication skills. This research intended to find the effect of tasks on students' spoken interaction…

  11. The Effects of Describing Antecedent Stimuli and Performance Criteria in Task Analysis Instruction for Graphing

    ERIC Educational Resources Information Center

    Tyner, Bryan C.; Fienup, Daniel M.

    2016-01-01

    Task analyses are ubiquitous to applied behavior analysis interventions, yet little is known about the factors that make them effective. Numerous task analyses have been published in behavior analytic journals for constructing single-subject design graphs; however, learner outcomes using these task analyses may fall short of what could be…

  12. Effects of Planning on Task Load, Knowledge, and Tool Preference: A Comparison of Two Tools

    ERIC Educational Resources Information Center

    Bonestroo, Wilco J.; de Jong, Ton

    2012-01-01

    Self-regulated learners are expected to plan their own learning. Because planning is a complex task, it is not self-evident that all learners can perform this task successfully. In this study, we examined the effects of two planning support tools on the quality of created plans, planning behavior, task load, and acquired knowledge. Sixty-five…

  13. Effects of goal- and task-oriented motivation in the guilty action test.

    PubMed

    Elaad, Eitan

    2013-04-01

    The present study examined the effectiveness of the Guilty Action Test in detecting critical information from goal-oriented and task-oriented informed innocent examinees. A mock crime procedure was employed and informed innocent participants were either motivated to prove innocence (goal-oriented motivation) or to prove innocence by being cooperative on the test (task-oriented motivation). Half of the participants in each motivation condition were promised course credit reward for successful completion of their mission to prove innocence or to be cooperative (high incentive level). The other half were promised no reward (low incentive level). A fifth group of uninformed innocent participants served for control purposes. Electrodemal, respiration, and cardiovascular measures were used to indicate the motivation effects. Results showed that the combination of goal-oriented instructions and an incentive for success contributed to enhanced responses to the crime-related information. The combination of task-oriented instructions and an incentive for success attenuated these responses. Skin conductance responses were most sensitive to these effects. Theoretical and practical aspects of the results were discussed.

  14. Range Commanders Council Meteorology Group 88th Meeting: NASA Marshall Space Flight Center Task Report, 2004

    NASA Technical Reports Server (NTRS)

    Roberts, Barry C.

    2004-01-01

    Supported Return-to-Flight activities by providing surface climate data from Kennedy Space Center used primarily for ice and dew formation studies, and upper air wind analysis primarily used for ascent loads analyses. The MSFC Environments Group's Terrestrial and Planetary Environments Team documented Space Shuttle day-of-launch support activities by publishing a document in support of SSP Return-to-Flight activities entitled "Space Shuttle Program Flight Operations Support". The team also formalized the Shuttle Natural Environments Technical Panel and chaired the first special session of the SSP Natural Environments Panel meeting at KSC, November 4-7,2003.58 participants from NASA, DOD and other government agencies from across the country attended the meeting.

  15. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking.

    PubMed

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the "laws of perceptual organization" proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. "Additive effect" refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The "where" and "what" pathways might have played an important role in the additive grouping effect.

  16. Acceptance criteria for flattening filter-free photon beam from standard medical electron linear accelerator: AERB task group recommendations

    PubMed Central

    Sahani, G.; Sharma, S. D.; Sharma, P. K. Dash; Deshpande, D. D.; Negi, P. S.; Sathianarayanan, V. K.; Rath, G. K.

    2014-01-01

    Medical electron linear accelerators with the capability of generating unflat photon (flattening filter-free, FFF) beams are also available commercially for clinical applications in radiotherapy. However, the beam characteristics evaluation criteria and parameters are not yet available for such photon beams. Atomic Energy Regulatory Board (AERB) of India constituted a Task Group comprising experts from regulatory agency, advisory body/research and technical institutions, and clinical radiotherapy centers in the country to evolve and recommend the acceptance criteria for the flattening filter-free (FFF) photon beams. The Task Group thoroughly reviewed the literature and inputs of the manufactures/suppliers of the FFF linac and recommended a set of dosimetry parameters for evaluating the characteristics of the unflat photon beam. The recommendations included the evaluation of quality index, degree of unflatness, difference in percentage surface dose between flat and unflat photon beams, percentage depth dose at 10 cm depth, off-axis-ratios and radiation beam penumbra. The recommended parameters were evaluated for FFF photon beams generated by three different models of the linac, and it was observed that recommended evaluation methods are simple and easy to be implemented with the existing dosimetry and quality assurance infrastructure of the linac facilities of the radiotherapy departments. Recommendations were also made for periodic quality control check of the unflat photon beams and constancy evaluation in the beam characteristics. PMID:25525307

  17. Intraoperative radiation therapy using mobile electron linear accelerators: report of AAPM Radiation Therapy Committee Task Group No. 72.

    PubMed

    Beddar, A Sam; Biggs, Peter J; Chang, Sha; Ezzell, Gary A; Faddegon, Bruce A; Hensley, Frank W; Mills, Michael D

    2006-05-01

    Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT, (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems.

  18. Two Paths from the Same Place: Task Driven and Human Centered Evolution of a Group Information Surface

    NASA Technical Reports Server (NTRS)

    Russell, Daniel M.; Trimble, Jay; Wales, Roxana; Clancy, Daniel (Technical Monitor)

    2003-01-01

    This is the tale of two different implementations of a collaborative information tool, that started from the same design source. The Blueboard, developed at IBM Research, is a tool for groups to use in exchanging information in a lightweight, informal collaborative way. It began as a large display surface for walk-by use in a corporate setting and has evolved in response to task demands and user needs. At NASA, the MERBoard is being designed to support surface operations for the upcoming Mars Exploration Rover Missions. The MERBoard is a tool that was inspired by the Blueboard design, extending this design to support the collaboration requirements for viewing, annotating, linking and distributing information for the science and engineering teams that will operate two rovers on the surface of Mars. The ways in which each group transformed the system reflects not only technical requirements, but also the needs of users in each setting and embedding of the system within the larger socio-technical environment. Lessons about how task requirements, information flow requirements and work practice drive the evolution of a system are illustrated.

  19. The Effects of Music and Group Stage on Group Leader and Member Behavior in Psychoeducational Groups for Children of Divorce

    ERIC Educational Resources Information Center

    Cercone, Kristin; DeLucia-Waack, Janice

    2012-01-01

    This study examined the effects of music and group stage on group process and group leader and member behavior within 8-week psychoeducational groups for children of divorce. Audiotapes of group sessions were rated using the Interactional Process Analysis and the Group Sessions Ratings Scale. Both treatment groups were very similar in terms of…

  20. Imaging brain fatigue from sustained mental workload: an ASL perfusion study of the time-on-task effect.

    PubMed

    Lim, Julian; Wu, Wen-Chau; Wang, Jiongjiong; Detre, John A; Dinges, David F; Rao, Hengyi

    2010-02-15

    During sustained periods of a taxing cognitive workload, humans typically display time-on-task (TOT) effects, in which performance gets steadily worse over the period of task engagement. Arterial spin labeling (ASL) perfusion functional magnetic resonance imaging (fMRI) was used in this study to investigate the neural correlates of TOT effects in a group of 15 subjects as they performed a 20-min continuous psychomotor vigilance test (PVT). Subjects displayed significant TOT effects, as seen in progressively slower reaction times and significantly increased mental fatigue ratings after the task. Perfusion data showed that the PVT activates a right lateralized fronto-parietal attentional network in addition to the basal ganglia and sensorimotor cortices. The fronto-parietal network was less active during post-task rest compared to pre-task rest, and regional CBF decrease in this network correlated with performance decline. These results demonstrate the persistent effects of cognitive fatigue in the fronto-parietal network after a period of heavy mental work and indicate the critical role of this attentional network in mediating TOT effects. Furthermore, resting regional CBF in the thalamus and right middle frontal gyrus prior to task onset was predictive of subjects' subsequent performance decline, suggesting that resting CBF quantified by ASL perfusion fMRI may be a useful indicator of performance potential and a marker of the level of fatigue in the neural attentional system.

  1. Effects of Classroom Bilingualism on Task Shifting, Verbal Memory, and Word Learning in Children

    PubMed Central

    Kaushanskaya, Margarita; Gross, Megan; Buac, Milijana

    2014-01-01

    We examined the effects of classroom bilingual experience in children on an array of cognitive skills. Monolingual English-speaking children were compared with children who spoke English as the native language and who had been exposed to Spanish in the context of dual-immersion schooling for an average of two years. The groups were compared on a measure of non-linguistic task-shifting; measures of verbal short-term and working memory; and measures of word-learning. The two groups of children did not differ on measures of non-linguistic task-shifting and verbal short-term memory. However, the classroom-exposure bilingual group outperformed the monolingual group on the measure of verbal working memory and a measure of word-learning. Together, these findings indicate that while exposure to a second language in a classroom setting may not be sufficient to engender changes in cognitive control, it can facilitate verbal memory and verbal learning. PMID:24576079

  2. Waste area Grouping 2 Phase I task data report: Human health risk assessment

    SciTech Connect

    Purucker, S.T.; Douthat, D.M.

    1996-06-01

    This report is one of five reports issued in 1996 that provide follow- up information to the Phase 1 Remedial Investigation (RI) Report for Waste Area Grouping (WAG) 2 at Oak Ridge National Laboratory (ORNL). The five reports address areas of concern that could cause potential human health risk and ecological risk within WAG2 at ORNL. The purpose of this report is to present a summary of the human health risk assessment results based on the data collected for the WAG 2 Phase 1 RI. Estimates of risk are provided based on measured concentrations in the surface water, floodplain soil, and sediment of White Oak Creek, Melton Branch, and their tributaries. The human health risk assessment methodology used in this risk assessment is based on Risk Assessment Guidance for Superfund (RAGS). First, the data for the different media are elevated to determine usability for risk assessment. Second, through the process of selecting chemicals of potential concern (COPCs), contaminants to be considered in the risk assessment are identified for each assessment of exposure potential is performed, and exposure pathways are identified. Subsequently, exposure is estimated quantitatively, and the toxicity of each of the COPCs is determined. The results of these analyses are combined and summarized in a risk characterization.

  3. Extrapolating Accelerated UV Weathering Data: Perspective From PVQAT Task Group 5 (Presentation)

    SciTech Connect

    Miller, D.; Annigoni, E.; Ballion, A.; Bokria, J.; Bruckman, L.; Burns, D.; Elliott, L.; French, R.; Fowler, S.; Gu, X.; Honeker, C.; Khonkar, H.; Kohl, M.; Krommenhoek, P.; Peret-Aebi, L.; Phillips, N.; Scott, K.; Sculati-Meillaud, F.; Shioda, T.

    2015-02-01

    Taskgroup 5 (TG5) is concerned with a accelerated aging standard incorporating factors including ultraviolet radiation, temperature, and moisture. Separate experiments are being conducted in support of a test standard via the regional sub-groups in Asia, Europe, and the United States. The authors will describe the objectives and timeline for the TG5 interlaboratory study being directed out of the USA. Qualitative preliminary data from the experiment is presented. To date, the encapsulation transmittance experiment has: replicated behaviors of fielded materials (including specimen location- and formulation additive-specific discoloration); demonstrated coupling between UV aging and temperature; demonstrated that degradation in EVA results from UV- aging; and obtained good qualitative comparison between Xe and UVA-340 sources for EVA. To date, the encapsulation adhesion experiment (using the compressive shear test to quantify strength of attachment) has demonstrated that attachment strength can decrease drastically (>50%) with age; however, early results suggest significant factor (UV, T, RH) dependence. Much remains to be learned about adhesion.

  4. Effects of force reflection on servomanipulator task performance

    SciTech Connect

    Draper, J.V.; Moore, W.E.; Herndon, J.N.; Weil, B.S.

    1986-01-01

    This paper reports results of a testing program that assessed the impact of force reflection on servomanipulator task performance. The testing program compared three force-reflection levels: 4 to 1 (four units of force on the slave produce one unit of force at the master controller), 1 to 1, and infinity to 1 (no force reflection). Time required to complete tasks, rate of occurrence of errors, the maximum force applied to task components, and variability in forces during completion of representative remote handling tasks were used as dependent variables. Operators exhibited lower error rates, lower peak forces, and more consistent application of forces using force reflection than they did without it. These data support the hypothesis that force reflection provides useful information for servomanipulator operators.

  5. Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking

    PubMed Central

    Wang, Chundi; Zhang, Xuemin; Li, Yongna; Lyu, Chuang

    2016-01-01

    Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the “laws of perceptual organization” proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. “Additive effect” refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The “where” and “what” pathways might have played an important role in the additive grouping effect. PMID:27199875

  6. Effect(s) of Language Tasks on Severity of Disfluencies in Preschool Children with Stuttering.

    PubMed

    Zamani, Peyman; Ravanbakhsh, Majid; Weisi, Farzad; Rashedi, Vahid; Naderi, Sara; Hosseinzadeh, Ayub; Rezaei, Mohammad

    2017-04-01

    Speech disfluency in children can be increased or decreased depending on the type of linguistic task presented to them. In this study, the effect of sentence imitation and sentence modeling on severity of speech disfluencies in preschool children with stuttering is investigated. In this cross-sectional descriptive analytical study, 58 children with stuttering (29 with mild stuttering and 29 with moderate stuttering) and 58 typical children aged between 4 and 6 years old participated. The severity of speech disfluencies was assessed by SSI-3 and TOCS before and after offering each task. In boys with mild stuttering, The mean stuttering severity scores in two tasks of sentence imitation and sentence modeling were [Formula: see text] and [Formula: see text] respectively ([Formula: see text]). But, in boys with moderate stuttering the stuttering severity in the both tasks were [Formula: see text] and [Formula: see text] respectively ([Formula: see text]). In girls with mild stuttering, the stuttering severity in two tasks of sentence imitation and sentence modeling were [Formula: see text] and [Formula: see text] respectively ([Formula: see text]). But, in girls with moderate stuttering the mean stuttering severity in the both tasks were [Formula: see text] and [Formula: see text] respectively ([Formula: see text]). In both gender of typical children, the score of speech disfluencies had no significant difference between two tasks ([Formula: see text]). In preschool children with mild stuttering and peer non-stutters, performing the tasks of sentence imitation and sentence modeling could not increase the severity of stuttering. But, in preschool children with moderate stuttering, doing the task of sentence modeling increased the stuttering severity score.

  7. A Closer Look at the Thresholds of Thermal Damage: Workshop Report by an ICNIRP Task Group

    PubMed Central

    Sienkiewicz, Zenon; van Rongen, Eric; Croft, Rodney; Ziegelberger, Gunde; Veyret, Bernard

    2016-01-01

    Abstract The International Commission on Non-Ionizing Radiation Protection issued guidelines in 1998 for limiting public and occupational exposure to radiofrequency electromagnetic fields (100 kHz to 300 GHz). As part of the process of updating this advice, a 2‐d workshop titled “A closer look at the thresholds of thermal damage” was held from 26–28 May 2015 in Istanbul to re-examine the thermal basis of the guidelines and to provide further information on heat-related effects and thresholds of thermal damage. Overall, the workshop provided much useful information relevant to revision of the guidelines. Participants indicated that the effects of heating from radiofrequency fields are consistent with those from other sources, and that the information derived from those studies can be applied to radiofrequency-induced heating. Another conclusion was that absolute temperature of tissues was more important for thermal damage than temperature change. The discussion suggested that the 6‐min averaging time used in international guidelines was valid for whole-body exposures but with a large uncertainty: 30 min may be a more appropriate averaging time for localized exposures, and less than 1 min for implanted medical devices. The duration of whole-body radiofrequency exposure is a critical parameter that often determines the effect threshold, but this will be affected by other, ongoing thermoregulation, which is dependant on many factors. The thresholds for localized radiofrequency exposure were difficult to determine because of the potential range of exposure conditions and the possibility of radiofrequency-induced local hotspots. Suggestions for future dose metrics and further research were discussed and are included in this report. PMID:27472755

  8. Effects of display curvature, display zone, and task duration on legibility and visual fatigue during visual search task.

    PubMed

    Park, Sungryul; Choi, Donghee; Yi, Jihhyeon; Lee, Songil; Lee, Ja Eun; Choi, Byeonghwa; Lee, Seungbae; Kyung, Gyouhyung

    2017-04-01

    This study examined the effects of display curvature (400, 600, 1200 mm, and flat), display zone (5 zones), and task duration (15 and 30 min) on legibility and visual fatigue. Each participant completed two 15-min visual search task sets at each curvature setting. The 600-mm and 1200-mm settings yielded better results than the flat setting in terms of legibility and perceived visual fatigue. Relative to the corresponding centre zone, the outermost zones of the 1200-mm and flat settings showed a decrease of 8%-37% in legibility, whereas those of the flat setting showed an increase of 26%-45% in perceived visual fatigue. Across curvatures, legibility decreased by 2%-8%, whereas perceived visual fatigue increased by 22% during the second task set. The two task sets induced an increase of 102% in the eye complaint score and a decrease of 0.3 Hz in the critical fusion frequency, both of which indicated an increase in visual fatigue. In summary, a curvature of around 600 mm, central display zones, and frequent breaks are recommended to improve legibility and reduce visual fatigue.

  9. Human performance in a multiple-task environment: effects of automation reliability on visual attention allocation.

    PubMed

    Cullen, Ralph H; Rogers, Wendy A; Fisk, Arthur D

    2013-11-01

    Diagnostic automation has been posited to alleviate the high demands of multiple-task environments; however, mixed effects have been found pertaining to performance aid success. To better understand these effects, attention allocation must be studied directly. We developed a multiple-task environment to study the effects of automation on visual attention. Participants interacted with a system providing varying levels of automation and automation reliability and then were transferred to a system with no support. Attention allocation was measured by tracking the number of times each task was viewed. We found that participants receiving automation allocated their time according to the task frequency and that tasks that benefited most from automation were most harmed when it was removed. The results suggest that the degree to which automation affects multiple-task performance is dependent on the relative attributes of the tasks involved. Moreover, there is an inverse relationship between support and cost when automation fails.

  10. Effects of Planning and Goal Setting on Reducing Latency to Task Engagement for Struggling Readers in Middle School

    ERIC Educational Resources Information Center

    Stevenson, Nathan A.

    2016-01-01

    The current study examined the effect of a planning and goal-setting intervention in reducing latency to task engagement. This study used a multiple baseline design across participants for two seventh-grade and two eighth-grade students in a remedial reading class. The behavioral intervention was administered in small groups at the start of each…

  11. Effect of Posttraumatic Stress on Study Time in a Task Measuring Four Component Processes Underlying Text-Level Reading

    ERIC Educational Resources Information Center

    Sullivan, Michael P.; Griffiths, Gina G.; Sohlberg, Mckay Moore

    2014-01-01

    Purpose: To investigate the effect of combat-related posttraumatic stress disorder (PTSD) on 4 components underlying text-level reading comprehension. Method: A group of 17 veterans with PTSD and 17 matched control participants took part. An experimental task required participants to read and study 3-sentence paragraphs describing semantic…

  12. The Effects of Task Instruction Sheets on the Performance of Vocational Horticulture Students. Summary of Research, 29.

    ERIC Educational Resources Information Center

    Scanlon, Dennis C.; Newcomb, L. H.

    A study investigated the effect that task instruction sheets had on the performance of vocational horticulture students when being taught a unit on poinsettia production. Using a post-test only control group design, researchers administered a 35-item multiple choice test on poinsettia production to 207 students in 12 randomly selected eleventh…

  13. The Effect of Video-Based Tasks in Listening Comprehension of Iranian Pre-Intermediate EFL Learners

    ERIC Educational Resources Information Center

    Sarani, Abdullah; Behtash, Esmail Zare; Nezhad Arani, Saieed Moslemi

    2014-01-01

    This study aims at finding the effect of video-based tasks in improving the listening comprehension ability of Iranian pre-intermediate EFL (English Foreign Language) learners. After determining the level of learners, an experimental and control group, each of 20 participants, were nominated to contribute to the study. From the time the pre-test…

  14. Strength capabilities and subjective limits in repetitive manual exertions: task and hand dominance effects.

    PubMed

    Johnson, Hope E; Nussbaum, Maury A

    2003-01-01

    Strength and subjectively determined exertion limits are used widely for ergonomic evaluation. Although compilations of such data for the hand and finger exist, several important limitations include the use of inexperienced participants and constrained postures. In this study both strength and maximum acceptable limits (MAL, 2-hour duration) were obtained from both industrial workers and inexperienced volunteers in 10 simulated hand-intensive automotive assembly tasks. To expand the applicability of the results, the effects of hand-dominance were also determined. Results were compared with existing recommendations (by Kodak and the American Conference of Governmental Industrial Hygienists threshold limit value for hand-intensive activities), and showed that across the diverse tasks the former yields values slightly below the 1st percentile of MAL, whereas the latter values are slightly higher than the 25th percentile. MALs were found to be approximately 50% of strength, consistent with earlier reports, and suggesting that acceptable limits are strongly influenced by physical capacity. Substantial differences ( approximately 30%) in strength and MALs were found between the two participant groups, emphasizing that participants should resemble the target population. Hand-dominance effects were statistically significant though of moderate size ( approximately 5%). Strength and MAL distributions are provided that can be used for evaluation and design of a variety of hand-intensive occupational tasks.

  15. Evaluating the Effects of Formal Corrective Feedback on Off-Task/On-Task Behavior of Mild Intellectually Disabled Students: An Action Research Study

    ERIC Educational Resources Information Center

    George, Kevin

    2016-01-01

    The off-task behavior demonstrated by the study participants appears to interfere with classroom instruction, contribute to poor academic performance and in many instances lead to disciplinary actions such as suspension. The purpose of the study entailed determining if formal corrective feedback has an effect on the off-task/on-task behavior of…

  16. Working Memory, Reasoning, and Task Switching Training: Transfer Effects, Limitations, and Great Expectations?

    PubMed Central

    Baniqued, Pauline L.; Ward, Nathan; Geyer, Alexandra; Kramer, Arthur F.

    2015-01-01

    Although some studies have shown that cognitive training can produce improvements to untrained cognitive domains (far transfer), many others fail to show these effects, especially when it comes to improving fluid intelligence. The current study was designed to overcome several limitations of previous training studies by incorporating training expectancy assessments, an active control group, and “Mind Frontiers,” a video game-based mobile program comprised of six adaptive, cognitively demanding training tasks that have been found to lead to increased scores in fluid intelligence (Gf) tests. We hypothesize that such integrated training may lead to broad improvements in cognitive abilities by targeting aspects of working memory, executive function, reasoning, and problem solving. Ninety participants completed 20 hour-and-a-half long training sessions over four to five weeks, 45 of whom played Mind Frontiers and 45 of whom completed visual search and change detection tasks (active control). After training, the Mind Frontiers group improved in working memory n-back tests, a composite measure of perceptual speed, and a composite measure of reaction time in reasoning tests. No training-related improvements were found in reasoning accuracy or other working memory tests, nor in composite measures of episodic memory, selective attention, divided attention, and multi-tasking. Perceived self-improvement in the tested abilities did not differ between groups. A general expectancy difference in problem-solving was observed between groups, but this perceived benefit did not correlate with training-related improvement. In summary, although these findings provide modest evidence regarding the efficacy of an integrated cognitive training program, more research is needed to determine the utility of Mind Frontiers as a cognitive training tool. PMID:26555341

  17. Working Memory, Reasoning, and Task Switching Training: Transfer Effects, Limitations, and Great Expectations?

    PubMed

    Baniqued, Pauline L; Allen, Courtney M; Kranz, Michael B; Johnson, Kathryn; Sipolins, Aldis; Dickens, Charles; Ward, Nathan; Geyer, Alexandra; Kramer, Arthur F

    2015-01-01

    Although some studies have shown that cognitive training can produce improvements to untrained cognitive domains (far transfer), many others fail to show these effects, especially when it comes to improving fluid intelligence. The current study was designed to overcome several limitations of previous training studies by incorporating training expectancy assessments, an active control group, and "Mind Frontiers," a video game-based mobile program comprised of six adaptive, cognitively demanding training tasks that have been found to lead to increased scores in fluid intelligence (Gf) tests. We hypothesize that such integrated training may lead to broad improvements in cognitive abilities by targeting aspects of working memory, executive function, reasoning, and problem solving. Ninety participants completed 20 hour-and-a-half long training sessions over four to five weeks, 45 of whom played Mind Frontiers and 45 of whom completed visual search and change detection tasks (active control). After training, the Mind Frontiers group improved in working memory n-back tests, a composite measure of perceptual speed, and a composite measure of reaction time in reasoning tests. No training-related improvements were found in reasoning accuracy or other working memory tests, nor in composite measures of episodic memory, selective attention, divided attention, and multi-tasking. Perceived self-improvement in the tested abilities did not differ between groups. A general expectancy difference in problem-solving was observed between groups, but this perceived benefit did not correlate with training-related improvement. In summary, although these findings provide modest evidence regarding the efficacy of an integrated cognitive training program, more research is needed to determine the utility of Mind Frontiers as a cognitive training tool.

  18. Task Switching versus Cue Switching: Using Transition Cuing to Disentangle Sequential Effects in Task-Switching Performance

    ERIC Educational Resources Information Center

    Schneider, Darryl W.; Logan, Gordon D.

    2007-01-01

    Recent methodological advances have allowed researchers to address confounds in the measurement of task-switch costs in task-switching performance by dissociating cue switching from task switching. For example, in the transition-cuing procedure, which involves presenting cues for task transitions rather than for tasks, cue transitions (cue…

  19. The Effects of Different Leadership Styles on Group Performance: A Field Experiment.

    ERIC Educational Resources Information Center

    Reilly, Anthony Joseph, III

    This study tested Fiedler's contingency model of leadership effectiveness on 86 nursing students in a large midwestern hospital. Fourteen individuals representing the task oriented and relationship-oriented leadership styles and two levels of sociometric status were randomly designated as leaders for small groups. The groups worked on five…

  20. Measuring treatment effects on dual-task performance: a framework for research and clinical practice

    PubMed Central

    Plummer, Prudence; Eskes, Gail

    2015-01-01

    The relevance of dual-task walking to everyday ambulation is widely acknowledged, and numerous studies have demonstrated that dual-task interference can significantly impact recovery of functional walking in people with neurological disorders. The magnitude and direction of dual-task interference is influenced by the interaction between the two tasks, including how individuals spontaneously prioritize their attention. Therefore, to accurately interpret and characterize dual-task interference and identify changes over time, it is imperative to evaluate single and dual-task performance in both tasks, as well as the tasks relative to each other. Yet, reciprocal dual-task effects (DTE) are frequently ignored. The purpose of this perspective paper is to present a framework for measuring treatment effects on dual-task interference, specifically taking into account the interactions between the two tasks and how this can provide information on whether overall dual-task capacity has improved or a different attentional strategy has been adopted. In discussing the clinical implications of using this framework, we provide specific examples of using this method and provide some explicit recommendations for research and clinical practice. PMID:25972801

  1. Effects of cognitive and motor tasks on the walking speed of individuals with chronic stroke

    PubMed Central

    Goh, Lee-Yin.; Tan, Isaac O.; Yang, Li C.; Ng, Shamay S.M.

    2017-01-01

    Abstract Walking speed is a measure of gait performance after a stroke and a predictor of community ambulatory competence. Although gait decrements during a cognitive or motor task after stroke are well-documented, the differential effects of motor and cognitive tasks on the comfortable and maximum walking speeds of individuals with chronic stroke have not been investigated. This study aimed to compare the effects of cognitive and motor tasks on the comfortable and maximum walking speeds of individuals with chronic stroke. This is a cross-sectional study. Thirty community-dwelling chronic stroke individuals were included. Time taken to complete the 10-meter Walk Test under various conditions, including walking alone, walking while completing a cognitive task, and walking while completing a motor task, was recorded, with each condition performed at comfortable as well as maximum walking speeds. Accuracy in performing the cognitive tasks was also assessed. The cognitive and motor tasks caused decrements in both comfortable and maximum walking speeds (P ≤ 0.001). The cognitive task had a greater influence than the motor task on maximum walking speed (P < 0.01). Individuals with chronic stroke tend to prioritize task accuracy and completion over maintaining walking speed. This phenomenon was more evident during the cognitive task than the motor task and was especially evident at maximum walking speed. PMID:28248885

  2. Effects of Body Mass Index on Task-Related Oxygen Uptake and Dyspnea during Activities of Daily Life in COPD

    PubMed Central

    Vaes, Anouk W.; Franssen, Frits M. E.; Meijer, Kenneth; Cuijpers, Martijn W. J.; Wouters, Emiel F. M.; Rutten, Erica P. A.; Spruit, Martijn A.

    2012-01-01

    Background Patients with COPD use a higher proportion of their peak aerobic capacity during the performance of domestic activities of daily life (ADLs) compared to healthy peers, accompanied by a higher degree of task-related symptoms. To date, the influence of body mass index (BMI) on the task-related metabolic demands remains unknown in patients with COPD. Therefore, the aim of our study was to determine the effects of BMI on metabolic load during the performance of 5 consecutive domestic ADLs in patients with COPD. Methodology Ninety-four COPD patients and 20 healhty peers performed 5 consecutive, self-paced domestic ADLs putting on socks, shoes and vest; folding 8 towels; putting away groceries; washing up 4 dishes, cups and saucers; and sweeping the floor for 4 min. Task-related oxygen uptake and ventilation were assessed using a mobile oxycon, while Borg scores were used to assess task-related dyspnea and fatigue. Principal Findings 1. Relative task-related oxygen uptake after the performance of domestic ADLs was increased in patients with COPD compared to healthy elderly, whereas absolute oxygen uptake is similar between groups; 2. Relative oxygen uptake and oxygen uptake per kilogram fat-free mass were comparable between BMI groups; and 3. Borg symptom scores for dyspnea en fatigue were comparable between BMI groups. Conclusion Patients with COPD in different BMI groups perform self-paced domestic ADLs at the same relative metabolic load, accompanied by comparable Borg symptom scores for dyspnea and fatigue. PMID:22815922

  3. AAPM Task Group 108: PET and PET/CT shielding requirements.

    PubMed

    Madsen, Mark T; Anderson, Jon A; Halama, James R; Kleck, Jeff; Simpkin, Douglas J; Votaw, John R; Wendt, Richard E; Williams, Lawrence E; Yester, Michael V

    2006-01-01

    The shielding of positron emission tomography (PET) and PET/CT (computed tomography) facilities presents special challenges. The 0.511 MeV annihilation photons associated with positron decay are much higher energy than other diagnostic radiations. As a result, barrier shielding may be required in floors and ceilings as well as adjacent walls. Since the patient becomes the radioactive source after the radiopharmaceutical has been administered, one has to consider the entire time that the subject remains in the clinic. In this report we present methods for estimating the shielding requirements for PET and PET/CT facilities. Information about the physical properties of the most commonly used clinical PET radionuclides is summarized, although the report primarily refers to fluorine-18. Typical PET imaging protocols are reviewed and exposure rates from patients are estimated including self-attenuation by body tissues and physical decay of the radionuclide. Examples of barrier calculations are presented for controlled and noncontrolled areas. Shielding for adjacent rooms with scintillation cameras is also discussed. Tables and graphs of estimated transmission factors for lead, steel, and concrete at 0.511 MeV are also included. Meeting the regulatory limits for uncontrolled areas can be an expensive proposition. Careful planning with the equipment vendor, facility architect, and a qualified medical physicist is necessary to produce a cost effective design while maintaining radiation safety standards.

  4. The effect of elicitation task on discourse coherence and cohesion in adolescents with brain injury.

    PubMed

    Van Leer, E; Turkstra, L

    1999-01-01

    Six adolescents with traumatic brain injury and six adolescents who had been hospitalized for an illness or injury not affecting the brain were administered two narrative tasks designed to vary in their demand for spontaneous organization of information and minimize the requirement for new learning. The discourse topics--a description of each subject's injury and hospitalization, and a re-telling of a current event--were chosen to be representative of discourse in adolescent daily living. Narratives produced by subjects in each group were compared between the two tasks on measures of coherence and cohesion. Subjects in both groups produced significantly more coherent and cohesive narratives in the personal event task than in the current event task, and there was no significant difference between groups. The results are discussed in relation to face validity of language tasks for adolescents, and the multiple factors contributing to adolescent social discourse.

  5. Effects of a Task-specific Exercise Program on Balance, Mobility, and Muscle Strength in the Elderly.

    PubMed

    Seo, Hyung-Seok; Lee, Jung-Ho; Park, Young-Han

    2014-11-01

    [Purpose] The aim of this study was to investigate the effects of a task-specific exercise program based on motor learning on balance ability and strength of the lower extremity in the elderly with/without falling experiences. [Subjects and Methods] Individuals who had experiences of falling over 2 times within the past 6 months were included in the falling group. The task-specific exercise program consisted of 3 stages (weeks 1-2, 3-4, and 5-6) and was conducted according to the level of difficulty in this study. [Results] The scores of the Korean version of the Activities-Specific Balance Confidence Scale and Performance-Oriented Mobility Assessment were significantly changed in both the falling group and non-falling group after the task-specific exercise program. In comparisons between the falling group and non-falling group, there were also significant differences in the Korean version of the Activities-Specific Balance Confidence Scale and muscle strength of the semitendinosus and gastrocnemius. [Conclusion] The task-specific exercise program has a positive effect on balance ability and muscle strength related to falls in the elderly.

  6. Effects of a Task-specific Exercise Program on Balance, Mobility, and Muscle Strength in the Elderly

    PubMed Central

    Seo, Hyung-Seok; Lee, Jung-Ho; Park, Young-Han

    2014-01-01

    [Purpose] The aim of this study was to investigate the effects of a task-specific exercise program based on motor learning on balance ability and strength of the lower extremity in the elderly with/without falling experiences. [Subjects and Methods] Individuals who had experiences of falling over 2 times within the past 6 months were included in the falling group. The task-specific exercise program consisted of 3 stages (weeks 1–2, 3–4, and 5–6) and was conducted according to the level of difficulty in this study. [Results] The scores of the Korean version of the Activities-Specific Balance Confidence Scale and Performance-Oriented Mobility Assessment were significantly changed in both the falling group and non-falling group after the task-specific exercise program. In comparisons between the falling group and non-falling group, there were also significant differences in the Korean version of the Activities-Specific Balance Confidence Scale and muscle strength of the semitendinosus and gastrocnemius. [Conclusion] The task-specific exercise program has a positive effect on balance ability and muscle strength related to falls in the elderly. PMID:25435679

  7. Effects of local information on group behavior

    SciTech Connect

    Roychowdhury, S.; Arora, N.; Sen, S.

    1996-12-31

    Researchers in the field of Distributed Artificial Intelligence have studied the effects of local decision-making on overall system performance in both cooperative and self-interested agent groups. The performance of individual agents depends critically on the quality of information available to it about local and global goals and resources. Whereas in general it is assumed that the more accurate and up-to-date the available information, the better is the expected performance of the individual and the group, this conclusion can be challenged in a number of scenarios.

  8. Automated Calculation of Water-equivalent Diameter (DW) Based on AAPM Task Group 220.

    PubMed

    Anam, Choirul; Haryanto, Freddy; Widita, Rena; Arif, Idam; Dougherty, Geoff

    2016-07-08

    The purpose of this study is to accurately and effectively automate the calculation of the water-equivalent diameter (DW) from 3D CT images for estimating the size-specific dose. DW is the metric that characterizes the patient size and attenuation. In this study, DW was calculated for standard CTDI phantoms and patient images. Two types of phantom were used, one representing the head with a diameter of 16 cm and the other representing the body with a diameter of 32 cm. Images of 63 patients were also taken, 32 who had undergone a CT head examination and 31 who had undergone a CT thorax examination. There are three main parts to our algorithm for automated DW calculation. The first part is to read 3D images and convert the CT data into Hounsfield units (HU). The second part is to find the contour of the phantoms or patients automatically. And the third part is to automate the calculation of DW based on the automated contouring for every slice (DW,all). The results of this study show that the automated calculation of DW and the manual calculation are in good agreement for phantoms and patients. The differences between the automated calculation of DW and the manual calculation are less than 0.5%. The results of this study also show that the estimating of DW,all using DW,n=1 (central slice along longitudinal axis) produces percentage differences of -0.92% ± 3.37% and 6.75%± 1.92%, and estimating DW,all using DW,n=9 produces percentage differences of 0.23% ± 0.16% and 0.87% ± 0.36%, for thorax and head examinations, respectively. From this study, the percentage differences between normalized size-specific dose estimate for every slice (nSSDEall) and nSSDEn=1 are 0.74% ± 2.82% and -4.35% ± 1.18% for thorax and head examinations, respectively; between nSSDEall and nSSDEn=9 are 0.00% ± 0.46% and -0.60% ± 0.24% for thorax and head examinations, respectively.

  9. Automated Calculation of Water-equivalent Diameter (DW ) Based on AAPM Task Group 220.

    PubMed

    Anam, Choirul; Haryanto, Freddy; Widita, Rena; Arif, Idam; Dougherty, Geoff

    2016-07-01

    The purpose of this study is to accurately and effectively automate the calculation of the water-equivalent diameter (DW) from 3D CT images for estimating the size-specific dose. DW is the metric that characterizes the patient size and attenuation. In this study, DW was calculated for standard CTDI phantoms and patient images. Two types of phantom were used, one representing the head with a diameter of 16 cm and the other representing the body with a diameter of 32 cm. Images of 63 patients were also taken, 32 who had undergone a CT head examination and 31 who had undergone a CT thorax examination. There are three main parts to our algorithm for automated DW calculation. The first part is to read 3D images and convert the CT data into Hounsfield units (HU). The second part is to find the contour of the phantoms or patients automatically. And the third part is to automate the calculation of DW based on the automated contouring for every slice (DW,all). The results of this study show that the automated calculation of DW and the manual calculation are in good agreement for phantoms and patients. The differences between the automated calculation of DW and the manual calculation are less than 0.5%. The results of this study also show that the estimating of DW,all using DW,n=1 (central slice along longitudinal axis) produces percentage differences of -0.92%±3.37% and 6.75%±1.92%, and estimating DW,all using DW,n=9 produces percentage differences of 0.23%±0.16% and 0.87%±0.36%, for thorax and head examinations, respectively. From this study, the percentage differences between normalized size-specific dose estimate for every slice (nSSDEall) and nSSDEn=1 are 0.74%±2.82% and -4.35%±1.18% for thorax and head examinations, respectively; between nSSDEall and nSSDEn=9 are 0.00%±0.46% and -0.60%±0.24% for thorax and head examinations, respectively. PACS number(s): 87.57.Q-, 87.57.uq.

  10. Making Sense of an Unexpected Detrimental Effect of Sign Language Use in a Visual Task

    ERIC Educational Resources Information Center

    Romero Lauro, Leonor J.; Crespi, Marta; Papagno, Costanza; Cecchetto, Carlo

    2014-01-01

    What supports deaf signers advantage over nonsigners on visuospatial short-term memory (STM) tasks is still a matter of debate. We compared the performance of 18 deaf Italian Sign Language (LIS) users with that of a matched group of Italian hearing nonsigners in three different tasks: two versions of the Corsi Block test, namely span forward and…

  11. Concurrent working memory task decreases the Stroop interference effect as indexed by the decreased theta oscillations.

    PubMed

    Zhao, Y; Tang, D; Hu, L; Zhang, L; Hitchman, G; Wang, L; Chen, A

    2014-03-14

    Working memory (WM) tasks may increase or decrease the interference effect of concurrently performed cognitive control tasks. However, the neural oscillatory correlates of this modulation effect of WM on the Stroop task are still largely unknown. In the present study, behavioral and electroencephalographic (EEG) data were recorded from 32 healthy participants during their performance of the single Stroop task and the same task with a concurrent WM task. We observed that the Stroop interference effect represented in both response times (RTs) and theta-band event-related spectral perturbation (ERSP) magnitude reduced under the dual-task condition compared with the single-task condition. The reduction of interference in theta-band ERSP was further positively correlated with interference reduction in RTs, and was mainly explained by the source in the left middle frontal gyrus. In conclusion, the present study suggests that the effect of concurrent WM tasks on the reduction of the Stroop interference effect can be indexed by EEG oscillations in theta-band rhythm in the centro-frontal regions and this modulation was mediated by the reduced cognitive control under the concurrent WM task.

  12. Effective Casimir conditions and group coherent states

    NASA Astrophysics Data System (ADS)

    Bojowald, Martin; Tsobanjan, Artur

    2014-06-01

    Properties of group coherent states can be derived ‘effectively’ without knowing full wave functions. The procedure is detailed in this paper as an example of general methods for effective constraints. The role of constraints in the present context is played by a Casimir condition that puts states within an irreducible representation of a Lie group (or, equivalently, on a quantization of a co-adjoint orbit of the dual Lie algebra). Simplifications implied by a Casimir condition, compared with general first-class constraints, allows one to show that the correct number of degrees of freedom is obtained after imposing the condition. When combined with conditions to saturate uncertainty relations, moments of group coherent states can be derived. A detailed example in quantum cosmology (cosmic forgetfulness) illustrates the usefulness of the methods.

  13. Attitude Differences and Task Performance for Black and White Naval Recruits in Problem-Solving Groups of Differing Size and Racial Composition.

    DTIC Science & Technology

    A field study was made in which 288 black and white naval personnel (224 recruits and 64 squad leaders) in groups of varying size and racial composition performed two problem-solving tasks (knot tying and ship-routing). Black and white leaders, subordinates and group types (25% black tetrads, 75% black tetrads, racially balanced dyads and tetrads) were compared in measures of self - esteem , duration of speech, locus of control, job and general satisfaction, Bales IPA behavior, and performance on the tasks.

  14. The effect of processing code, response modality and task difficulty on dual task performance and subjective workload in a manual system

    NASA Technical Reports Server (NTRS)

    Liu, Yili; Wickens, Christopher D.

    1987-01-01

    This paper reports on the first experiment of a series studying the effect of task structure and difficulty demand on time-sharing performance and workload in both automated and corresponding manual systems. The experimental task involves manual control time-shared with spatial and verbal decisions tasks of two levels of difficulty and two modes of response (voice or manual). The results provide strong evidence that tasks and processes competing for common processing resources are time shared less effecively and have higher workload than tasks competing for separate resources. Subjective measures and the structure of multiple resources are used in conjunction to predict dual task performance. The evidence comes from both single-task and from dual-task performance.

  15. Composite Overwrapped Pressure Vessels: Database Extension Task 3.0 and Impact Damage Effects Control Task 8.0

    NASA Technical Reports Server (NTRS)

    Beeson, Harold D.; Davis, Dennis D.; Ross, William L., Sr.; Tapphorn, Ralph M.

    2002-01-01

    This document represents efforts accomplished at the NASA Johnson Space Center White Sands Test Facility (WSTF) in support of the Enhanced Technology for Composite Overwrapped Pressure Vessels (COPV) Program, a joint research and technology effort among the U.S. Air Force, NASA, and the Aerospace Corporation. WSTF performed testing for several facets of the program. Testing that contributed to the Task 3.0 COPV database extension objective included baseline structural strength, failure mode and safe-life, impact damage tolerance, sustained load/impact effect, and materials compatibility. WSTF was also responsible for establishing impact protection and control requirements under Task 8.0 of the program. This included developing a methodology for establishing an impact control plan. Seven test reports detail the work done at WSTF. As such, this document contributes to the database of information regarding COPV behavior that will ensure performance benefits and safety are maintained throughout vessel service life.

  16. Comparison of the Effects of Ketamine and Morphine on the Performance of Representative Military Tasks

    DTIC Science & Technology

    2010-08-01

    USAARL Report No. 2010-17 Comparison of the Effects of Ketamine and Morphine on the Performance of Representative Military Tasks By Steven J...Effects of Ketamine and Morphine on the Performance of Representative Military Tasks Steven J. Gaydos, Amanda M. Kelley, Catherine M. Webb, Jeremy R. Athy...IM) ketamine versus 10 mg of IM morphine on the performance of representative Warrior Skill Tasks in 48 healthy subjects. Ketamine demonstrated

  17. Cycle Time Task Group

    DTIC Science & Technology

    2004-12-01

    strengths (core competencies) – LEAN manufacturing principles • Creates inventory “pull” system • Reduces Work in Process (WIP) inventory requirements...levels/requirements/rotable parts status and locations • Simplify internal processes and adopt LEAN manufacturing concepts – Highlights supply chain issues

  18. MBA Recruitment Task Group

    DTIC Science & Technology

    2003-02-05

    talented, recent MBA graduates from top-tier U.S. business schools . These graduates bring new ideas, energy and private sector management...sets and school performance may be different, all Fellows are expected to be recent graduates of top-tier business schools who will be performing in...the “CEO/Ambassador” to one of the target business schools where DoD is establishing a physical recruiting presence. The person’s role would be to

  19. Fuel Hedging Task Group

    DTIC Science & Technology

    2004-03-01

    scandals such as Enron are possible. • Government is already “self-hedged”: – OMB considers the federal government to be “self-hedged” on...this approach should involve none of the potential political embarrassment associated with comparisons to Enron and payment of hedging fees to

  20. Effectiveness of Science Tasks and Plans for Siberian Scholars.

    ERIC Educational Resources Information Center

    Marchuk, G. I.

    1972-01-01

    Science and Technology research plans formulated for the Siberian Department of the U.S.S.R. Academy of Sciences are analyzed in this article to illustrate the tasks of scholars, workers, and engineering and technical personnel in the fulfillment of the 24th party congress resolutions The hypothesis of developing Siberia and the Far East up to the…

  1. Effects of Speaking Task on Intelligibility in Parkinson's Disease

    ERIC Educational Resources Information Center

    Tjaden, Kris; Wilding, Greg

    2011-01-01

    Intelligibility tests for dysarthria typically provide an estimate of overall severity for speech materials elicited through imitation or read from a printed script. The extent to which these types of tasks and procedures reflect intelligibility for extemporaneous speech is not well understood. The purpose of this study was to compare…

  2. Outsourcing of Domestic Tasks and Time-Saving Effects

    ERIC Educational Resources Information Center

    van der Lippe, Tanja; Tijdens, Kea; de Ruijter, Esther

    2004-01-01

    The increased participation of women in paid labor has changed the organization of domestic work. This article deals with a strategy to cope with remaining domestic duties; to what extent are domestic tasks outsourced, what are the main determinants, and does it indeed save time spent on housework? Five outsourcing options are investigated:…

  3. The Effect of Occupational Growth on Labor Force Task Characteristics.

    ERIC Educational Resources Information Center

    Szafran, Robert F.

    1996-01-01

    Examination of changes in 495 occupations from 1950-1990 shows an increased likelihood of tasks with high levels of complexity and social interaction, decreased likelihood of fine or gross motor skills or harsh climatic conditions. There is evidence that jobs have become polarized on the need for fine motor skills and level of social interaction.…

  4. Nonstrategic Contributions to Putatively Strategic Effects in Selective Attention Tasks

    ERIC Educational Resources Information Center

    Risko, Evan F.; Blais, Chris; Stolz, Jennifer A.; Besner, Derek

    2008-01-01

    Proportion compatible manipulations are often used to index strategic processes in selective attention tasks. Here, a subtle confound in proportion compatible manipulations is considered. Specifically, as the proportion of compatible trials increases, the ratio of complete repetitions and complete alternations to partial repetitions increases on…

  5. Effect of Sexual Arousal on Cortical Coupling During Performance of the Tower of Hanoi Task in Young Men.

    PubMed

    Amezcua-Gutiérrez, Claudia; Ruiz-Díaz, Marina; Hernández-González, Marisela; Guevara, Miguel Angel; Ågmo, Anders; Sanz-Martin, Araceli

    2017-01-01

    Sexual arousal affects cognitive processing, which depends on the coordinated functioning among cortical areas. The aim of this research was to determine whether previous observation of videos with sexual content affects the degree of cortical electroencephalographic (EEG) coupling during performance of an executive task. Cortical EEG correlations were calculated in three groups of heterosexual men under three conditions: at rest; during observation of a video with neutral, aggressive, or erotic content; and while performing the Tower of Hanoi task (TOH). Based on self-reports, it was shown that the erotic video induced general and sexual arousal, while the aggressive video affected valence and general arousal. Task performance was similar in all three groups. During performance of TOH, only the erotic group showed a decreased correlation between prefrontal areas with an increased correlation between parietal and prefrontotemporal areas, specifically in the slow bands. It is likely that these changes in the degree of cortical coupling could be associated with the cognitive strategies or functional adaptations that participants require to adequately solve the task during a state of sexual arousal. These data could contribute to improving our understanding of the central nervous mechanisms that underlie the effect of sexual arousal on the cognitive processes involved in tasks like TOH.

  6. Combining Partial Directed Coherence and Graph Theory to Analyse Effective Brain Networks of Different Mental Tasks

    PubMed Central

    Huang, Dengfeng; Ren, Aifeng; Shang, Jing; Lei, Qiao; Zhang, Yun; Yin, Zhongliang; Li, Jun; von Deneen, Karen M.; Huang, Liyu

    2016-01-01

    Purpose: The aim of this study is to qualify the network properties of the brain networks between two different mental tasks (play task or rest task) in a healthy population. Methods and Materials: EEG signals were recorded from 19 healthy subjects when performing different mental tasks. Partial directed coherence (PDC) analysis, based on Granger causality (GC), was used to assess the effective brain networks during the different mental tasks. Moreover, the network measures, including degree, degree distribution, local and global efficiency in delta, theta, alpha, and beta rhythms were calculated and analyzed. Results: The local efficiency is higher in the beta frequency and lower in the theta frequency during play task whereas the global efficiency is higher in the theta frequency and lower in the beta frequency in the rest task. Significance: This study reveals the network measures during different mental states and efficiency measures may be used as characteristic quantities for improvement in attentional performance. PMID:27242495

  7. Effect of motion cues during complex curved approach and landing tasks: A piloted simulation study

    NASA Technical Reports Server (NTRS)

    Scanlon, Charles H.

    1987-01-01

    A piloted simulation study was conducted to examine the effect of motion cues using a high fidelity simulation of commercial aircraft during the performance of complex approach and landing tasks in the Microwave Landing System (MLS) signal environment. The data from these tests indicate that in a high complexity MLS approach task with moderate turbulence and wind, the pilot uses motion cues to improve path tracking performance. No significant differences in tracking accuracy were noted for the low and medium complexity tasks, regardless of the presence of motion cues. Higher control input rates were measured for all tasks when motion was used. Pilot eye scan, as measured by instrument dwell time, was faster when motion cues were used regardless of the complexity of the approach tasks. Pilot comments indicated a preference for motion. With motion cues, pilots appeared to work harder in all levels of task complexity and to improve tracking performance in the most complex approach task.

  8. Combined Effects of Attention and Motivation on Visual Task Performance: Transient and Sustained Motivational Effects

    PubMed Central

    Engelmann, Jan B.; Damaraju, Eswar; Padmala, Srikanth; Pessoa, Luiz

    2008-01-01

    We investigated how the brain integrates motivational and attentional signals by using a neuroimaging paradigm that provided separate estimates for transient cue- and target-related signals, in addition to sustained block-related responses. Participants performed a Posner-type task in which an endogenous cue predicted target location on 70% of trials, while motivation was manipulated by varying magnitude and valence of a cash incentive linked to task performance. Our findings revealed increased detection performance (d′) as a function of incentive value. In parallel, brain signals revealed that increases in absolute incentive magnitude led to cue- and target-specific response modulations that were independent of sustained state effects across visual cortex, fronto-parietal regions, and subcortical regions. Interestingly, state-like effects of incentive were observed in several of these brain regions, too, suggesting that both transient and sustained fMRI signals may contribute to task performance. For both cue and block periods, the effects of administering incentives were correlated with individual trait measures of reward sensitivity. Taken together, our findings support the notion that motivation improves behavioral performance in a demanding attention task by enhancing evoked responses across a distributed set of anatomical sites, many of which have been previously implicated in attentional processing. However, the effect of motivation was not simply additive as the impact of absolute incentive was greater during invalid than valid trials in several brain regions, possibly because motivation had a larger effect on reorienting than orienting attentional mechanisms at these sites. PMID:19434242

  9. The effects of study task on prestimulus subsequent memory effects in the hippocampus.

    PubMed

    de Chastelaine, Marianne; Rugg, Michael D

    2015-11-01

    Functional magnetic resonance imaging (fMRI) was employed to examine the effects of a study task manipulation on pre-stimulus activity in the hippocampus predictive of later successful recollection. Eighteen young participants were scanned while making either animacy or syllable judgments on visually presented study words. Cues presented before each word denoted which judgment should be made. Following the study phase, a surprise recognition memory test was administered in which each test item had to be endorsed as "Remembered," "Known," or "New." As expected, "deep" animacy judgments led to better memory for study items than did "shallow" syllable judgments. In both study tasks, pre-stimulus subsequent recollection effects were evident in the interval between the cue and the study item in bilateral anterior hippocampus. However, the direction of the effects differed according to the study task: whereas pre-stimulus hippocampal activity on animacy trials was greater for later recollected items than items judged old on the basis of familiarity (replicating prior findings), these effects reversed for syllable trials. We propose that the direction of pre-stimulus hippocampal subsequent memory effects depends on whether an optimal pre-stimulus task set facilitates study processing that is conducive or unconducive to the formation of contextually rich episodic memories.

  10. The IUGS Task Group on Global Geoscience Professionalism - promoting professional skills professionalism in the teaching, research and application of geoscience for the protection and education of the public

    NASA Astrophysics Data System (ADS)

    Allington, Ruth; Fernandez-Fuentes, Isabel

    2013-04-01

    A new IUGS Task Group entitled the Task Group on Global Geoscience Professionalism was formed in 2012 and launched at a symposium at the 341GC in Brisbane on strengthening communication between fundamental and applied geosciences and between geoscientists and public. The Task Group aims to ensure that the international geoscience community is engaged in a transformation of its profession so as to embed the need for a professional skills base alongside technical and scientific skills and expertise, within a sound ethical framework in all arenas of geoscience practice. This needs to be established during training and education and reinforced as CPD throughout a career in geoscience as part of ensuring public safety and effective communication of geoscience concepts to the public. The specific objective of the Task Group on Global Geoscience Professionalism that is relevant to this poster session is: • To facilitate a more 'joined up' geoscience community fostering better appreciation by academics and teachers of the professional skills that geoscientists need in the workplace, and facilitate better communication between academic and applied communities leading to more effective application of research findings and technology to applied practitioners and development of research programmes that truly address urgent issues. Other Task Group objectives are: • To provide a specific international forum for discussion of matters of common concern and interest among geoscientists and geoscientific organizations involved in professional affairs, at the local, national and international level; • To act as a resource to IUGS on professional affairs in the geosciences as they may influence and impact "Earth Science for the Global Community" in general - both now and in the future; • To offer and provide leadership and knowledge transfer services to countries and geoscientist communities around the world seeking to introduce systems of professional governance and self

  11. Effects of Age and Task Load on Drivers’ Response Accuracy and Reaction Time When Responding to Traffic Lights

    PubMed Central

    Salvia, Emilie; Petit, Claire; Champely, Stéphane; Chomette, René; Di Rienzo, Franck; Collet, Christian

    2016-01-01

    Due to population aging, elderly drivers represent an increasing proportion of car drivers. Yet, how aging alters sensorimotor functions and impacts driving safety remains poorly understood. This paper aimed at assessing to which extent elderly drivers are sensitive to various task loads and how this affects the reaction time (RT) in a driving context. Old and middle-aged people completed RT tasks which reproduced cognitive demands encountered while driving. Participants had to detect and respond to traffic lights or traffic light arrows as quickly as possible, under three experimental conditions of incremental difficulty. In both groups, we hypothesized that decision-making would be impacted by the number of cues to be processed. The first test was a simple measure of RT. The second and third tests were choice RT tasks requiring the processing of 3 and 5 cues, respectively. Responses were collected within a 2 s time-window. Otherwise, the trial was considered a no-response. In both groups, the data revealed that RT, error rate (incorrect answers), and no-response rate increased along with task difficulty. However, the middle-aged group outperformed the elderly group. The RT difference between the two groups increased drastically along with task difficulty. In the third test, the rate of no-response suggested that elderly drivers needed more than 2 s to process complex information and respond accurately. Both prolonged RT and increased no-response rate, especially for difficult tasks, might attest an impairment of cognitive abilities in relation to aging. Accordingly, casual driving conditions for young drivers may be particularly complex and stressful for elderly people who should thus be informed about the effects of normal aging upon driving. PMID:27462266

  12. Short-term visual deprivation reduces interference effects of task-irrelevant facial expressions on affective prosody judgments

    PubMed Central

    Fengler, Ineke; Nava, Elena; Röder, Brigitte

    2015-01-01

    Several studies have suggested that neuroplasticity can be triggered by short-term visual deprivation in healthy adults. Specifically, these studies have provided evidence that visual deprivation reversibly affects basic perceptual abilities. The present study investigated the long-lasting effects of short-term visual deprivation on emotion perception. To this aim, we visually deprived a group of young healthy adults, age-matched with a group of non-deprived controls, for 3 h and tested them before and after visual deprivation (i.e., after 8 h on average and at 4 week follow-up) on an audio–visual (i.e., faces and voices) emotion discrimination task. To observe changes at the level of basic perceptual skills, we additionally employed a simple audio–visual (i.e., tone bursts and light flashes) discrimination task and two unimodal (one auditory and one visual) perceptual threshold measures. During the 3 h period, both groups performed a series of auditory tasks. To exclude the possibility that changes in emotion discrimination may emerge as a consequence of the exposure to auditory stimulation during the 3 h stay in the dark, we visually deprived an additional group of age-matched participants who concurrently performed unrelated (i.e., tactile) tasks to the later tested abilities. The two visually deprived groups showed enhanced affective prosodic discrimination abilities in the context of incongruent facial expressions following the period of visual deprivation; this effect was partially maintained until follow-up. By contrast, no changes were observed in affective facial expression discrimination and in the basic perception tasks in any group. These findings suggest that short-term visual deprivation per se triggers a reweighting of visual and auditory emotional cues, which seems to possibly prevail for longer durations. PMID:25954166

  13. Modulating effect of COMT Val(158)Met polymorphism on interference resolution during a working memory task.

    PubMed

    Jaspar, Mathieu; Dideberg, Vinciane; Bours, Vincent; Maquet, Pierre; Collette, Fabienne

    2015-04-01

    Genetic variability related to the catechol-O-methyltransferase (COMT) gene has received increasing attention in the last 15years, in particular as a potential modulator of the neural substrates underlying inhibitory processes and updating in working memory (WM). In an event-related functional magnetic resonance imaging (fMRI) study, we administered a modified version of the Sternberg probe recency task (Sternberg, 1966) to 43 young healthy volunteers, varying the level of interference across successive items. The task was divided into two parts (high vs. low interference) to induce either proactive or reactive control processes. The participants were separated into three groups according to their COMT Val(158)Met genotype [Val/Val (VV); Val/Met (VM); Met/Met (MM)]. The general aim of the study was to determine whether COMT polymorphism has a modulating effect on the neural substrates of interference resolution during WM processing. Results indicate that interfering trials were associated with greater involvement of frontal cortices (bilateral medial frontal gyrus, left precentral and superior frontal gyri, right inferior frontal gyrus) in VV homozygous subjects (by comparison to Met allele carriers) only in the proactive condition of the task. In addition, analysis of peristimulus haemodynamic responses (PSTH) revealed that the genotype-related difference observed in the left SFG was specifically driven by a larger increase in activity from the storage to the recognition phase of the interfering trials in VV homozygous subjects. These results confirm the impact of COMT genotype on inhibitory processes during a WM task, with an advantage for Met allele carriers. Interestingly, this impact on frontal areas is present only when the level of interference is high, and especially during the transition from storage to recognition in the left superior frontal gyrus.

  14. Effectiveness of Disc 'O' Sit cushions on attention to task in second-grade students with attention difficulties.

    PubMed

    Pfeiffer, Beth; Henry, Amy; Miller, Stephanie; Witherell, Suzie

    2008-01-01

    This study investigated the effectiveness of a type of dynamic seating system, the Disc 'O' Sit cushion (Gymnic, Osoppo, Italy), for improving attention to task among second-grade students with attention difficulties. Sixty-three second-grade students participated in the study. Using a randomized controlled trial design, 31 students were assigned to a treatment group, and 32 were assigned to a control group. Treatment group participants used Disc 'O' Sit cushions throughout the school day for a 2-week period. The teachers completed the Behavior Rating Inventory of Executive Functioning (Gioia, Isquith, Guy, & Kenworthy, 1996) for each participant before and after the intervention. An analysis of variance identified a statistically significant difference in the attention to task before and after the intervention for the treatment group. The results of the study provide preliminary evidence for the use of the Disc 'O' Sit cushion as an occupational therapy intervention to improve attention in the school setting.

  15. The Interactive Effects of Pragmatic-Eliciting Tasks and Pragmatic Instruction

    ERIC Educational Resources Information Center

    Fukuya, Yoshinori J; Martinez-Flor, Alicia

    2008-01-01

    The effects of data-gathering methods on pragmatic data have been well documented, yet an inquiry into the interactive effects of assessment tasks with pragmatic instruction has received scant attention. This study investigated the interaction between two assessment tasks (e-mail and phone) and two types of pragmatic instruction (explicit and…

  16. Postpassage Questions: Task and Reader Effects on Comprehension and Metacomprehension Processes.

    ERIC Educational Resources Information Center

    Davey, Beth

    1987-01-01

    Explores the effects of question task conditions on reading comprehension and metacomprehension for proficient readers, disabled readers, and deaf readers. Finds several significant interaction effects for both demonstrated and perceived comprehension performance in selected-response and constructed-response question tasks under both lookback and…

  17. Long-Term Effects of a Token Economy on Target and Off-Task Behaviors.

    ERIC Educational Resources Information Center

    Wasserman, Theodore H.; Vogrin, Daniel J.

    1979-01-01

    Examined the effects of a token economy on off-task behavior occurring concurrently with the reinforcement of target behavior. Results indicated that while the token economy maintained effectiveness in terms of increasing the frequency of target behaviors, the frequency of off-task or inappropriate behaviors also increased as the year progressed.…

  18. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: Report of Task Group 192

    SciTech Connect

    Podder, Tarun K.; Beaulieu, Luc; Caldwell, Barrett; Cormack, Robert A.; Crass, Jostin B.; Dicker, Adam P.; Yu, Yan; Fenster, Aaron; Fichtinger, Gabor; Meltsner, Michael A.; Moerland, Marinus A.; Nath, Ravinder; Rivard, Mark J.; Salcudean, Tim; Song, Danny Y.; Thomadsen, Bruce R.

    2014-10-15

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3–6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests

  19. AAPM and GEC-ESTRO guidelines for image-guided robotic brachytherapy: report of Task Group 192.

    PubMed

    Podder, Tarun K; Beaulieu, Luc; Caldwell, Barrett; Cormack, Robert A; Crass, Jostin B; Dicker, Adam P; Fenster, Aaron; Fichtinger, Gabor; Meltsner, Michael A; Moerland, Marinus A; Nath, Ravinder; Rivard, Mark J; Salcudean, Tim; Song, Danny Y; Thomadsen, Bruce R; Yu, Yan

    2014-10-01

    In the last decade, there have been significant developments into integration of robots and automation tools with brachytherapy delivery systems. These systems aim to improve the current paradigm by executing higher precision and accuracy in seed placement, improving calculation of optimal seed locations, minimizing surgical trauma, and reducing radiation exposure to medical staff. Most of the applications of this technology have been in the implantation of seeds in patients with early-stage prostate cancer. Nevertheless, the techniques apply to any clinical site where interstitial brachytherapy is appropriate. In consideration of the rapid developments in this area, the American Association of Physicists in Medicine (AAPM) commissioned Task Group 192 to review the state-of-the-art in the field of robotic interstitial brachytherapy. This is a joint Task Group with the Groupe Européen de Curiethérapie-European Society for Radiotherapy & Oncology (GEC-ESTRO). All developed and reported robotic brachytherapy systems were reviewed. Commissioning and quality assurance procedures for the safe and consistent use of these systems are also provided. Manual seed placement techniques with a rigid template have an estimated in vivo accuracy of 3-6 mm. In addition to the placement accuracy, factors such as tissue deformation, needle deviation, and edema may result in a delivered dose distribution that differs from the preimplant or intraoperative plan. However, real-time needle tracking and seed identification for dynamic updating of dosimetry may improve the quality of seed implantation. The AAPM and GEC-ESTRO recommend that robotic systems should demonstrate a spatial accuracy of seed placement ≤1.0 mm in a phantom. This recommendation is based on the current performance of existing robotic brachytherapy systems and propagation of uncertainties. During clinical commissioning, tests should be conducted to ensure that this level of accuracy is achieved. These tests should

  20. Effective Time Management in Battalion Task Force Operations

    DTIC Science & Technology

    1993-06-01

    at the National Training Center is used to isolate areas that are symptomatic of time management deficiencies and to establish that a problem of...managing exists within task force operations. This study establishes that time management is a problem and that current doctrinal references offer...incomplete time management guidance. This study then suggests a variety of techniques and procedures to improve the problem. This study concludes time can be

  1. Human-Centered Planning for Effective Task Autonomy

    DTIC Science & Technology

    2012-05-01

    introduce human-centered planning to model and reason about humans in the environment in addition to their own state and goals to determine how to act...and whether, who, and how to seek help. The thesis first contributes an understanding of what and how to model humans in the environment through user...to learn these models both through surveys and online while the device is performing tasks. The thesis then introduces human-centered conditional

  2. The Effects of Time on Task in Response Selection - An ERP Study of Mental Fatigue

    PubMed Central

    Möckel, Tina; Beste, Christian; Wascher, Edmund

    2015-01-01

    Long lasting involvement in a cognitive task leads to mental fatigue. Substantial efforts have been undertaken to understand this phenomenon. However, it has been demonstrated that some changes with time on task are not only related to mental fatigue. The present study intends to clarify these effects of time on task unrelated to mental fatigue on response selection processes at the behavioural and electrophysiological level (using event-related potentials, ERPs). Participants had to perform a Simon task for more than 3 hours and rated their experienced mental fatigue and motivation to continue with the task at several time points during the experiment. The results show that at the beginning of the experiment some unspecific modulations of training and adaptation are evident. With time on task participants’ ability to resolve response conflict appears to become impaired. The results reveal that time on task effects cannot be completely explained by mental fatigue. Instead, it seems that an interplay of adaptation at the beginning and motivational effects in the course of a task modulate performance and neurophysiological parameters. In future studies it will be important to account for the relative contribution of adaptation and motivation parameters when time on task effects are investigated. PMID:26054837

  3. The Effects of Time on Task in Response Selection--An ERP Study of Mental Fatigue.

    PubMed

    Möckel, Tina; Beste, Christian; Wascher, Edmund

    2015-06-09

    Long lasting involvement in a cognitive task leads to mental fatigue. Substantial efforts have been undertaken to understand this phenomenon. However, it has been demonstrated that some changes with time on task are not only related to mental fatigue. The present study intends to clarify these effects of time on task unrelated to mental fatigue on response selection processes at the behavioural and electrophysiological level (using event-related potentials, ERPs). Participants had to perform a Simon task for more than 3 hours and rated their experienced mental fatigue and motivation to continue with the task at several time points during the experiment. The results show that at the beginning of the experiment some unspecific modulations of training and adaptation are evident. With time on task participants' ability to resolve response conflict appears to become impaired. The results reveal that time on task effects cannot be completely explained by mental fatigue. Instead, it seems that an interplay of adaptation at the beginning and motivational effects in the course of a task modulate performance and neurophysiological parameters. In future studies it will be important to account for the relative contribution of adaptation and motivation parameters when time on task effects are investigated.

  4. Effect of evaluative others upon learning and performance of a complex motor task.

    PubMed

    Haas, J; Roberts, G C

    1975-06-01

    Two experiments were conducted to assess the effect of evaluation potential upon learning and performing a complex motor task. In Experiment 1, 45 subjects learned the motor task (mirror tracing) to criterion and were then introduced to one of three treatments. Subjects performed the task either (a) alone, (b) in the presence of a blindfolded audience, or (c) in the presence of an evaluative audience. In Experiment 2, 45 subjects were introduced to the same three treatments but the subjects did not learn the task beforehand. The subjects learning the motor task were significantly inhibited by the evaluative audience, while the subjects who had already learned the task were significantly facilitated in their motor responses. The blindfolded audience also had an effect upon learning and performance. The results of both experiments were discussed in relation to their support of Cottrell's evaluation potential hypothesis.

  5. Task-specific effects of modular body armor.

    PubMed

    Larsen, Brianna; Netto, Kevin; Aisbett, Brad

    2014-04-01

    Eleven recreationally active males performed 11 circuits of military work, wearing torso armor on one occasion, and full armor on another. Performance was measured by the time taken to complete individual tasks, and the overall time to completion (TTC) for each circuit. Heart rate, intestinal temperature, ratings of perceived exertion (RPE), and thermal sensation were recorded after each circuit. Participants' circuit TTC was no different between conditions; however, specific tasks were differentially impeded by the two armor configurations. Vaulting and crawling were significantly slower (0.28 ± 0.06 and 0.55 ± 0.26 seconds) in full armor; however, box lifting and shooting were significantly slower (0.36 ± 0.18 and 0.86 ± 0.23 seconds) when wearing torso armor. Heart rate and core temperature were significantly higher during the full armor trial (5 ± 1 beats · min(-1) and 0.22 ± 0.03 °C). Similarly, RPE and thermal sensation were significantly higher (1 ± 0 and 0.5 ± 0.0) during the full armor condition. Military tasks were differentially impaired by the armor configurations used, which suggests a need to explore role-specific armor for military personnel. Physiological and perceptual responses were elevated in full armor, which could be exacerbated during longer periods of work or in hot conditions.

  6. Effect of donepezil on reversal learning in a touch screen-based operant task.

    PubMed

    Chen, Woei-Shin; Wong, Fong-Kuan; Chapman, Paul F; Pemberton, Darrel J

    2009-10-01

    Impairments in reversal learning, which are commonly observed in patients with psychiatric disorders, remain difficult to treat. There is still a debate over the beneficial effects of cholinergic enhancers on improving behavioural flexibility. The objective of this study was to investigate the effect of an acetylcholinesterase inhibitor, donepezil, on the performance of a rodent Probabilistic Reversal Learning task. Lister-Hooded rats were trained to retrieve food rewards by discriminating two computer-generated stimuli in an automated touch screen-based operant task. When a steady performance was achieved, the stimulus-reward rule was reversed. Each rat was given a 30-min training session daily for 24 days and donepezil was administered 30 min before each training session. Systemic treatment with donepezil had no effect on trial accuracy of the two-stimulus discrimination training. However, the donepezil group showed enhanced performance in the reversal learning. Our result showed that treatment with donepezil significantly enhanced Probabilistic Reversal Learning performance in healthy animals. On the basis of this finding, the inhibition of the central acetylcholinesterase would seem to be a potential therapeutic approach to treat behavioural inflexibility.

  7. Effects of Physical Impairment on Grenade Throwing and Weapon Loading Tasks

    DTIC Science & Technology

    2015-03-01

    modeling for task- based impairment. 2. Synopsis Physical impairment of a Soldier during a mission will inevitably change the Soldier’s ability to...these tasks and the threshold at which they can no longer be successfully executed based solely on physical impairment. 13. Recommendation It...ARL-TR-7241 ● MAR 2015 US Army Research Laboratory Effects of Physical Impairment on Grenade Throwing and Weapon Loading Tasks

  8. Cognitive tasks during expectation affect the congruency ERP effects to facial expressions

    PubMed Central

    Lin, Huiyan; Schulz, Claudia; Straube, Thomas

    2015-01-01

    Expectancy congruency has been shown to modulate event-related potentials (ERPs) to emotional stimuli, such as facial expressions. However, it is unknown whether the congruency ERP effects to facial expressions can be modulated by cognitive manipulations during stimulus expectation. To this end, electroencephalography (EEG) was recorded while participants viewed (neutral and fearful) facial expressions. Each trial started with a cue, predicting a facial expression, followed by an expectancy interval without any cues and subsequently the face. In half of the trials, participants had to solve a cognitive task in which different letters were presented for target letter detection during the expectancy interval. Furthermore, facial expressions were congruent with the cues in 75% of all trials. ERP results revealed that for fearful faces, the cognitive task during expectation altered the congruency effect in N170 amplitude; congruent compared to incongruent fearful faces evoked larger N170 in the non-task condition but the congruency effect was not evident in the task condition. Regardless of facial expression, the congruency effect was generally altered by the cognitive task during expectation in P3 amplitude; the amplitudes were larger for incongruent compared to congruent faces in the non-task condition but the congruency effect was not shown in the task condition. The findings indicate that cognitive tasks during expectation reduce the processing of expectation and subsequently, alter congruency ERP effects to facial expressions. PMID:26578938

  9. Cognitive tasks during expectation affect the congruency ERP effects to facial expressions.

    PubMed

    Lin, Huiyan; Schulz, Claudia; Straube, Thomas

    2015-01-01

    Expectancy congruency has been shown to modulate event-related potentials (ERPs) to emotional stimuli, such as facial expressions. However, it is unknown whether the congruency ERP effects to facial expressions can be modulated by cognitive manipulations during stimulus expectation. To this end, electroencephalography (EEG) was recorded while participants viewed (neutral and fearful) facial expressions. Each trial started with a cue, predicting a facial expression, followed by an expectancy interval without any cues and subsequently the face. In half of the trials, participants had to solve a cognitive task in which different letters were presented for target letter detection during the expectancy interval. Furthermore, facial expressions were congruent with the cues in 75% of all trials. ERP results revealed that for fearful faces, the cognitive task during expectation altered the congruency effect in N170 amplitude; congruent compared to incongruent fearful faces evoked larger N170 in the non-task condition but the congruency effect was not evident in the task condition. Regardless of facial expression, the congruency effect was generally altered by the cognitive task during expectation in P3 amplitude; the amplitudes were larger for incongruent compared to congruent faces in the non-task condition but the congruency effect was not shown in the task condition. The findings indicate that cognitive tasks during expectation reduce the processing of expectation and subsequently, alter congruency ERP effects to facial expressions.

  10. Majority, Minority, and Parity: Effects of Gender and Group Size on Perceived Group Variability

    ERIC Educational Resources Information Center

    Voci, Alberto; Hewstone, Miles; Crisp, Richard J.; Rubin, Mark

    2008-01-01

    We investigated the effects of gender and group size on perceptions of group variability, using groups of students taking different majors that varied in the proportion of men and women (female-majority, parity, and male-majority). We found that both group size and gender had consistent effects on perceived out-group variability, even when…

  11. Semantic Richness and Aging: The Effect of Number of Features in the Lexical Decision Task.

    PubMed

    Robert, Christelle; Rico Duarte, Liliana

    2016-04-01

    The aim of this study was to examine whether the effect of semantic richness in visual word recognition (i.e., words with a rich semantic representation are faster to recognize than words with a poorer semantic representation), is changed with aging. Semantic richness was investigated by manipulating the number of features of words (NOF), i.e., the number of characteristics that describe the meaning of words. Half of the words had a high NOF and the other half had a low NOF. Young adults (19.6 years) and older adults (66.3 years) performed a lexical decision task. An interaction was found between age group and NOF on word latencies. More precisely, a facilitatory effect of NOF was observed for the young adults, but not for the older ones. These data are consistent with the assumption of an age-related decline in feedback activation from semantics to orthography.

  12. Effect of exercise on the auditory discrimination task in perimenopausal women: a preliminary study.

    PubMed

    Hwang, R-J; Wu, H-Y; Chen, H-J; Yan, Y-J

    2016-06-01

    Background The climacteric phase of menopausal transition (perimenopause) is marked by reproductive hormone fluctuations and reduced cognitive capacity. Exercise enhances neurocognitive performance. However, auditory perceptual sensitivity has not been examined. Purpose This study aimed to determine the effect of aerobic exercise on the response speed (reaction time) and error rate during auditory processing among perimenopausal women. Methods Three pitches (500, 1000, and 2000 Hz) were used during a simple auditory discrimination task, which was performed before and after exercise. We included 14 perimenopausal women and 17 right-handed young women (aged 46-54 years and 18-22 years, respectively). To achieve similar exercise intensity in both groups, we proposed two types of physical activities for each group. Mixed models statistics were used to analyze the reaction time and error rate before and after training in the two groups. Results Perimenopausal women exhibited a significantly longer reaction time than young women during the baseline auditory discrimination task (p < 0.05) but not during the second test. The error rate decreased significantly after exercise among perimenopausal women (p < 0.05) but not among young women. Thus, exercise had a stronger beneficial influence on auditory plasticity or sensitivity for perimenopausal women than for young women. Conclusion The ability of aerobic exercise to modulate auditory neurocognitive performance differs between the two groups. Aerobic exercise improves auditory discrimination performance specifically for perimenopausal women. These results provide preliminary evidence concerning the acoustic features of middle-aged women, underscoring the importance of exercise for preventing decline in auditory cognitive function in perimenopausal women.

  13. Preempting Performance Challenges: The Effects of Inoculation Messaging on Attacks to Task Self-Efficacy

    PubMed Central

    Jackson, Ben; Compton, Josh; Whiddett, Ryan; Anthony, David R.; Dimmock, James A.

    2015-01-01

    Although inoculation messages have been shown to be effective for inducing resistance to counter-attitudinal attacks, researchers have devoted relatively little attention toward studying the way in which inoculation theory principles might support challenges to psychological phenomena other than attitudes (e.g., self-efficacy). Prior to completing a physical (i.e., balance) task, undergraduates (N = 127, Mage = 19.20, SD = 2.16) were randomly assigned to receive either a control or inoculation message, and reported their confidence in their ability regarding the upcoming task. During the task, a confederate provided standardized negative feedback to all participants regarding their performance, and following the completion of the task, participants again reported their self-efficacy along with measures assessing in-task processes. Findings supported the viability of efficacy inoculation; controlling for pre-task self-efficacy, task performance, and relevant psycho-social variables (e.g., resilience, self-confidence robustness), participants in the inoculation condition reported greater confidence in their ability (i.e., task self-efficacy) than those in the control condition at post-task. Relative to those in the inoculation condition, participants in the control condition also experienced greater concentration disruption and self-presentation concerns during the task. PMID:25898287

  14. The effects of instructions on dual-task walking and cognitive task performance in people with Parkinson's disease.

    PubMed

    Kelly, Valerie E; Eusterbrock, Alexis J; Shumway-Cook, Anne

    2012-01-01

    Gait impairments are prevalent among people with Parkinson's disease (PD). Instructions to focus on walking can improve walking in PD, but the use of such a cognitive strategy may be limited under dual-task walking conditions, when walking is performed simultaneously with concurrent cognitive or motor tasks. This study examined how dual-task performance of walking and a concurrent cognitive task was affected by instructions in people with PD compared to healthy young and older individuals. Dual-task walking and cognitive task performance was characterized under two sets of instructions as follows: (1) focus on walking and (2) focus on the cognitive task. People with PD and healthy adults walked faster when instructed to focus on walking. However, when focused on walking, people with PD and young adults demonstrated declines in the cognitive task. This suggests that dual-task performance is flexible and can be modified by instructions in people with PD, but walking improvements may come at a cost to cognitive task performance. The ability to modify dual-task performance in response to instructions or other task and environmental factors is critical to mobility in daily life. Future research should continue to examine factors that influence dual-task performance among people with PD.

  15. The effects of cuing in time-shared tasks. [for aircraft flight route-way-point information

    NASA Technical Reports Server (NTRS)

    Chechile, R. A.; Sadoski, D. M.

    1983-01-01

    The results of two divided-attention experiments involving the editing of route-way-point displays on an avionics computer unit are reported. Two side tasks were required of the subjects, and either no cue, verbal cues appearing on the CRT, or symbolic cues (lights on the keyboard adjacent to keys to be used) were given to facilitate the primary editing task. Forty female and 30 male undergraduates were trained in the separate and combined tasks and divided randomly into groups of 25 for the cuing tests. A second test with three 10-subject groups was conducted at least one month later to investigate the efficacy of cuing for infrequently used procedures. It is found that only symbolic cuing significantly improved primary-task performance, increasing editing accuracy in the repetitive tests and reducing editing time in the delayed tests. Verbal cuing, probably because it requires additional cognitive effort, has no significant beneficial effect. These results are considered important for designing instruments for work environments requiring the performance of concurrent tasks, and as aircraft cockpits.

  16. Potential Discriminating Metrics of Cognitive Task Performance in Mission Command. Working Group 4 - Analysis of Human Decision-Making in a Networked Environment

    DTIC Science & Technology

    2012-01-01

    UNCLASSIFIED Potential Discriminating Metrics of Cognitive Task Performance in Mission Command Working Group 4 - Analysis of Human Decision...WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) TRADOC Analysis Center,Fort Leavenworth,KS,66027 8. PERFORMING ORGANIZATION...Cognitive Task Performance in MC Agenda • Background. • Methods. • Implications for MC Analysis . UNCLASSIFIED The Cognition Problem for Mission

  17. The Effects of Aging and Dual Task Demands on Language Production

    PubMed Central

    Kemper, Susan; Schmalzried, RaLynn; Herman, Ruth; Leedahl, Skye; Mohankumar, Deepthi

    2008-01-01

    A digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. After training on the pursuit rotor, participants were asked to track the moving target while providing a language sample. When simultaneously engaged, young adults experienced greater dual task costs to tracking, fluency, and grammatical complexity than older adults. Older adults were able to preserve their tracking performance by speaking more slowly. Individual differences in working memory, processing speed, and Stroop interference affected vulnerability to dual task costs. These results demonstrate the utility of using a digital pursuit rotor to study the effects of aging and dual task demands on language production and confirm prior findings that young and older adults use different strategies to accommodate to dual task demands. PMID:18982506

  18. An Analysis of the Effects of Smartphone Push Notifications on Task Performance with regard to Smartphone Overuse Using ERP

    PubMed Central

    Kim, Seul-Kee; Kim, So-Yeong; Kang, Hang-Bong

    2016-01-01

    Smartphones are used ubiquitously worldwide and are essential tools in modern society. However, smartphone overuse is an emerging social issue, and limited studies have objectively assessed this matter. The majority of previous studies have included surveys or behavioral observation studies. Since a previous study demonstrated an association between increased push notifications and smartphone overuse, we investigated the effects of push notifications on task performance. We detected changes in brainwaves generated by smartphone push notifications using the N200 and P300 components of event-related potential (ERP) to investigate both concentration and cognitive ability. ERP assessment indicated that, in both risk and nonrisk groups, the lowest N200 amplitude and the longest latency during task performance were found when push notifications were delivered. Compared to the nonrisk group, the risk group demonstrated lower P300 amplitudes and longer latencies. In addition, the risk group featured a higher rate of error in the Go-Nogo task, due to the negative influence of smartphone push notifications on performance in both risk and nonrisk groups. Furthermore, push notifications affected subsequent performance in the risk group. PMID:27366147

  19. An Analysis of the Effects of Smartphone Push Notifications on Task Performance with regard to Smartphone Overuse Using ERP.

    PubMed

    Kim, Seul-Kee; Kim, So-Yeong; Kang, Hang-Bong

    2016-01-01

    Smartphones are used ubiquitously worldwide and are essential tools in modern society. However, smartphone overuse is an emerging social issue, and limited studies have objectively assessed this matter. The majority of previous studies have included surveys or behavioral observation studies. Since a previous study demonstrated an association between increased push notifications and smartphone overuse, we investigated the effects of push notifications on task performance. We detected changes in brainwaves generated by smartphone push notifications using the N200 and P300 components of event-related potential (ERP) to investigate both concentration and cognitive ability. ERP assessment indicated that, in both risk and nonrisk groups, the lowest N200 amplitude and the longest latency during task performance were found when push notifications were delivered. Compared to the nonrisk group, the risk group demonstrated lower P300 amplitudes and longer latencies. In addition, the risk group featured a higher rate of error in the Go-Nogo task, due to the negative influence of smartphone push notifications on performance in both risk and nonrisk groups. Furthermore, push notifications affected subsequent performance in the risk group.

  20. The Effect of Video Game “Warm-up” on Performance of Laparoscopic Surgery Tasks

    PubMed Central

    Gentile, Douglas A.; Hanigan, Kevin; Danner, Omar K.

    2012-01-01

    Background: Performing laparoscopic procedures requires special training and has been documented as a significant source of surgical errors. “Warming up” before performing a task has been shown to enhance performance. This study investigates whether surgeons benefit from “warming up” using select video games immediately before performing laparoscopic partial tasks and clinical tasks. Methods: This study included 303 surgeons (249 men and 54 women). Participants were split into a control (n=180) and an experimental group (n=123). The experimental group played 3 previously validated video games for 6 minutes before task sessions. The Cobra Rope partial task and suturing exercises were performed immediately after the warm-up sessions. Results: Surgeons who played video games prior to the Cobra Rope drill were significantly faster on their first attempt and across all 10 trials. The experimental and control groups were significantly different in their total suturing scores (t=2.28, df=288, P<.05). The overall Top Gun score showed that the experimental group performed marginally better overall. Conclusion: This study demonstrates that subjects completing “warming-up” sessions with select video games prior to performing laparoscopic partial and clinical tasks (intracorporeal suturing) were faster and had fewer errors than participants not engaging in “warm-up.” More study is needed to determine whether this translates into superior procedural execution in the clinical setting. PMID:22906322

  1. Serial or overlapping processing in multitasking as individual preference: Effects of stimulus preview on task switching and concurrent dual-task performance.

    PubMed

    Reissland, Jessika; Manzey, Dietrich

    2016-07-01

    Understanding the mechanisms and performance consequences of multitasking has long been in focus of scientific interest, but has been investigated by three research lines more or less isolated from each other. Studies in the fields of the psychological refractory period, task switching, and interruptions have scored with a high experimental control, but usually do not give participants many degrees of freedom to self-organize the processing of two concurrent tasks. Individual strategies as well as their impact on efficiency have mainly been neglected. Self-organized multitasking has been investigated in the field of human factors, but primarily with respect to overall performance without detailed investigation of how the tasks are processed. The current work attempts to link aspects of these research lines. All of them, explicitly or implicitly, provide hints about an individually preferred type of task organization, either more cautious trying to work strictly serially on only one task at a time or more daring with a focus on task interleaving and, if possible, also partially overlapping (parallel) processing. In two experiments we investigated different strategies of task organization and their impact on efficiency using a new measure of overall multitasking efficiency. Experiment 1 was based on a classical task switching paradigm with two classification tasks, but provided one group of participants with a stimulus preview of the task to switch to next, enabling at least partial overlapping processing. Indeed, this preview led to a reduction of switch costs and to an increase of dual-task efficiency, but only for a subgroup of participants. They obviously exploited the possibility of overlapping processing, while the others worked mainly serially. While task-sequence was externally guided in the first experiment, Experiment 2 extended the approach by giving the participants full freedom of task organization in concurrent performance of the same tasks. Fine

  2. Commissioning specialist diabetes services for adults with diabetes: summary of a Diabetes UK Task and Finish group report.

    PubMed

    Goenka, N; Turner, B; Vora, J

    2011-12-01

    The increasing prevalence of diabetes, the drive to develop community services for diabetes and the Quality and Outcomes Framework for diabetes have led to improvements in the management of diabetes in primary care settings, with services traditionally provided only in specialist care now provided for many patients with diabetes by non-specialists. Consequently, there is a need to redefine roles, responsibilities and components of a specialist diabetes service to provide for the needs of patients in the National Health Service (NHS) today. The delivery of diabetes care is complex and touches on almost every aspect of the health service. It is the responsibility of those working within commissioning and specialist provider roles to work together with people with diabetes to develop, organize and deliver a full range of integrated diabetes care services. The local delivery model agreed within the local diabetes network, comprising specialist teams, primary care teams, commissioners and people with diabetes, should determine how the diabetes specialist services are organizsed. It should identify the roles and responsibilities of provider organizations to ensure that the right person provides the right care, at the right time, and in the right place. We summarize a report entitled 'Commissioning Diabetes Specialist Services for Adults with Diabetes', which has been produced, as a 'Task and Finish' group activity within Diabetes UK, to assist managers, commissioners and healthcare professionals to provide advice on the structure, roles and components of specialist diabetes services for adults.

  3. Report of ICRP Task Group 80: 'radiological protection in geological disposal of long-lived solid radioactive waste'.

    PubMed

    Weiss, W

    2012-01-01

    The report of International Commission on Radiological Protection (ICRP) Task Group 80 entitled 'Radiological protection in geological disposal of long-lived solid radioactive waste' updates and consolidates previous ICRP recommendations related to solid waste disposal (ICRP Publications 46, 77, and 81). The recommendations given in this report apply specifically to geological disposal of long-lived solid radioactive waste. The report explains how the 2007 system of radiological protection, described in ICRP Publication 103, can be applied in the context of the geological disposal of long-lived solid radioactive waste. The report is written as a self-standing document. It describes the different stages in the lifetime of a geological disposal facility, and addresses the application of relevant radiological protection principles for each stage depending on the various exposure situations that can be encountered. In particular, the crucial factor that influences application of the protection system over the different phases in the lifetime of a disposal facility is the level of oversight that is present. The level of oversight affects the capability to reduce or avoid exposures. Three main time frames have to be considered for the purpose of radiological protection: time of direct oversight when the disposal facility is being implemented and active oversight is taking place; time of indirect oversight when the disposal facility is sealed and indirect oversight is being exercised to provide additional assurance on behalf of the population; and time of no oversight when oversight is no longer exercised because memory is lost.

  4. Gender Effects When Learning Manipulative Tasks from Instructional Animations and Static Presentations

    ERIC Educational Resources Information Center

    Wong, Mona; Castro-Alonso, Juan C.; Ayres, Paul; Paas, Fred

    2015-01-01

    Humans have an evolved embodied cognition that equips them to deal easily with the natural movements of object manipulations. Hence, learning a manipulative task is generally more effective when watching animations that show natural motions of the task, rather than equivalent static pictures. The present study was completed to explore this…

  5. Effects of White Noise on Off-Task Behavior and Academic Responding for Children with ADHD

    ERIC Educational Resources Information Center

    Cook, Andrew; Bradley-Johnson, Sharon; Johnson, C. Merle

    2014-01-01

    We evaluated the effects of white noise played through headphones on off-task behavior, percentage of items completed, and percentage of items completed correctly for 3 students with attention deficit hyperactivity disorder (ADHD). Headphones plus white noise were associated with decreases in off-task behavior relative to baseline and…

  6. Evaluating the Effects of On-Task in a Box as a Class-Wide Intervention

    ERIC Educational Resources Information Center

    Battaglia, Allison A.; Radley, Keith C.; Ness, Emily J.

    2015-01-01

    The present study evaluated the effects of the On-Task in a Box intervention on student on-task behavior when used as a class-wide intervention. The intervention package includes self-monitoring, video modeling, and reinforcement contingency components. A multiple baseline design across three elementary classrooms was used to determine the effects…

  7. Personalised Adaptive Task Selection in Air Traffic Control: Effects on Training Efficiency and Transfer

    ERIC Educational Resources Information Center

    Salden, Ron J. C. M.; Paas, Fred; van Merrienboer, Jeroen J. G.

    2006-01-01

    The differential effects of four task selection methods on training efficiency and transfer in a computer-based training for Air Traffic Control were investigated. Two personalised conditions were compared with two corresponding yoked control conditions. The hypothesis that personalised adaptive task selection leads to more efficient training than…

  8. Effects of Task Index Variations On Transfer of Training Criteria. Final Report.

    ERIC Educational Resources Information Center

    Mirabella, Angelo; Wheaton, George R.

    The concluding series of a research program designed to validate a battery of task indexes for use in forecasting the effectiveness of training devices is described. Phase I collated 17 task indexes and applied them to sonar training devices, while in Phase II the 17 index battery was validated, using skill acquisition measures as criteria.…

  9. Task Card Instruction: The Effect of Different Cue Sequences on Students' Learning in Tennis

    ERIC Educational Resources Information Center

    Iserbyt, Peter; Madou, Bob; Elen, Jan; Behets, Daniel

    2010-01-01

    In physical education, task cards are often used in student-centred learning models. Consequently, a better understanding of how to deliver effective instructions by means of task cards would make a contribution to the literature. In this study, 80 right-handed university students in kinesiology were randomized across three experimental conditions…

  10. Effects of Peer Mediated Instruction with Task Cards on Motor Skill Acquisition in Tennis

    ERIC Educational Resources Information Center

    Iserbyt, Peter; Madou, Bob; Vergauwen, Lieven; Behets, Daniel

    2011-01-01

    This study compared the motor skill effects of a peer teaching format by means of task cards with a teacher-centered format. Tennis performance of eighth grade students (n = 55) was measured before and after a four week intervention period in a regular physical education program. Results show that peer mediated learning with task cards…

  11. Effects of Task Complexity on the Fluency and Lexical Complexity in EFL Students' Argumentative Writing

    ERIC Educational Resources Information Center

    Ong, Justina; Zhang, Lawrence Jun

    2010-01-01

    Based on Robinson's (2001a,b, 2003) Cognition Hypothesis and Skehan's (1998) Limited Attentional Capacity Model, this study explored the effects of task complexity on the fluency and lexical complexity of 108 EFL students' argumentative writing. Task complexity was manipulated using three factors: (1) availability of planning time; (2) provision…

  12. The Effect of Task Complexity on the Quality of EFL Learners' Argumentative Writing

    ERIC Educational Resources Information Center

    Sadeghi, Karim; Mosalli, Zahra

    2013-01-01

    Based on Robinson's (2005) Cognition Hypothesis and Skehan and Foster's (2001) Limited Attentional Capacity Model, the current study attempted to investigate the effect of manipulating task complexity on argumentative writing quality in terms of lexical complexity, fluency, grammatical accuracy, and syntactic complexity. Task complexity was…

  13. Effects of Reinforcement Choice on Task Responding in Individuals with Developmental Disabilities.

    ERIC Educational Resources Information Center

    Lerman, Dorthea C.; Iwata, Brian A.; Rainville, Beth; Adelinis, John D.; Crosland, Kimberly; Kogan, Jeffrey

    1997-01-01

    The effects of reinforcement choice on task performance were examined with six individuals (ages 6-39) who had been diagnosed with severe to profound mental retardation. Findings indicated that access to choice did not improve the task performance of the subjects when highly preferred items were already incorporated into instructional programs.…

  14. The Effect of Background Music and Background Noise on the Task Performance of Introverts and Extraverts

    ERIC Educational Resources Information Center

    Cassidy, Gianna; MacDonald, Raymond A. R.

    2007-01-01

    The study investigated the effects of music with high arousal potential and negative affect (HA), music with low arousal potential and positive affect (LA), and everyday noise, on the cognitive task performance of introverts and extraverts. Forty participants completed five cognitive tasks: immediate recall, free recall, numerical and delayed…

  15. The Effects of Planning Time and Language Levels on Task Performance of English Language Learners

    ERIC Educational Resources Information Center

    Righettini, Marielena

    2009-01-01

    This quantitative study examined the effects of planning time and high and low language levels on the task-based language performance of 51 first and second grade English language learners. Language performance during the task was assessed in terms of accuracy, complexity, and fluency. Quantitative analysis made use of four 2 x 2 factorial ANOVAs…

  16. The Effects of Delay of Feedback on a Delayed Concept Formation Transfer Task.

    ERIC Educational Resources Information Center

    Schroth, Marvin L.

    1992-01-01

    Delay and completeness of verbal information feedback were investigated within a transfer of learning paradigm involving concept formation. An experiment with 192 undergraduates indicates that, although delay of feedback (up to 30 seconds) slows speed of learning on the initial task, it has positive effects on the transfer task. (SLD)

  17. Effects of Immediate Repetition in L2 Speaking Tasks: A Focused Study

    ERIC Educational Resources Information Center

    Bei, Gavin Xiaoyue

    2013-01-01

    This paper reports on a focused investigation into the immediate effects of oral narrative task repetition by two adult EFL learners of intermediate and high proficiency. Two participants performed a narrative speaking task after watching a cartoon video clip and repeated their performance three times, followed by a retrospective report in an…

  18. The effect of haptic guidance and visual feedback on learning a complex tennis task.

    PubMed

    Marchal-Crespo, Laura; van Raai, Mark; Rauter, Georg; Wolf, Peter; Riener, Robert

    2013-11-01

    While haptic guidance can improve ongoing performance of a motor task, several studies have found that it ultimately impairs motor learning. However, some recent studies suggest that the haptic demonstration of optimal timing, rather than movement magnitude, enhances learning in subjects trained with haptic guidance. Timing of an action plays a crucial role in the proper accomplishment of many motor skills, such as hitting a moving object (discrete timing task) or learning a velocity profile (time-critical tracking task). The aim of the present study is to evaluate which feedback conditions-visual or haptic guidance-optimize learning of the discrete and continuous elements of a timing task. The experiment consisted in performing a fast tennis forehand stroke in a virtual environment. A tendon-based parallel robot connected to the end of a racket was used to apply haptic guidance during training. In two different experiments, we evaluated which feedback condition was more adequate for learning: (1) a time-dependent discrete task-learning to start a tennis stroke and (2) a tracking task-learning to follow a velocity profile. The effect that the task difficulty and subject's initial skill level have on the selection of the optimal training condition was further evaluated. Results showed that the training condition that maximizes learning of the discrete time-dependent motor task depends on the subjects' initial skill level. Haptic guidance was especially suitable for less-skilled subjects and in especially difficult discrete tasks, while visual feedback seems to benefit more skilled subjects. Additionally, haptic guidance seemed to promote learning in a time-critical tracking task, while visual feedback tended to deteriorate the performance independently of the task difficulty and subjects' initial skill level. Haptic guidance outperformed visual feedback, although additional studies are needed to further analyze the effect of other types of feedback visualization on

  19. The Effect of a Six-Month Dancing Program on Motor-Cognitive Dual-Task Performance in Older Adults.

    PubMed

    Hamacher, Dennis; Hamacher, Daniel; Rehfeld, Kathrin; Hökelmann, Anita; Schega, Lutz

    2015-10-01

    Dancing is a complex sensorimotor activity involving physical and mental elements which have positive effects on cognitive functions and motor control. The present randomized controlled trial aims to analyze the effects of a dancing program on the performance on a motor-cognitive dual task. Data of 35 older adults, who were assigned to a dancing group or a health-related exercise group, are presented in the study. In pretest and posttest, we assessed cognitive performance and variability of minimum foot clearance, stride time, and stride length while walking. Regarding the cognitive performance and the stride-to-stride variability of minimum foot clearance, interaction effects have been found, indicating that dancing lowers gait variability to a higher extent than conventional health-related exercise. The data show that dancing improves minimum foot clearance variability and cognitive performance in a dual-task situation. Multi-task exercises (like dancing) might be a powerful tool to improve motor-cognitive dual-task performance.

  20. Individual differences in working memory capacity determine the effects of oculomotor task load on concurrent word recall performance.

    PubMed

    Lee, Eun-Ju; Kwon, Gusang; Lee, Aekyoung; Ghajar, Jamshid; Suh, Minah

    2011-07-05

    In this study, the interaction between individual differences in working memory capacity, which were assessed by the Korean version of the California Verbal Learning Test (K-CVLT), and the effects of oculomotor task load on word recall performance are examined in a dual-task experiment. We hypothesized that varying levels of oculomotor task load should result in different demands on cognitive resources. The verbal working memory task used in this study involved a brief exposure to seven words to be remembered, followed by a 30-second delay during which the subject carried out an oculomotor task. Then, memory performance was assessed by having the subjects recall as many words as possible. Forty healthy normal subjects with no vision-related problems carried out four separate dual-tasks over four consecutive days of participation, wherein word recall performances were tested under unpredictable random SPEM (smooth pursuit eye movement), predictive SPEM, fixation, and eyes-closed conditions. The word recall performance of subjects with low K-CVLT scores was significantly enhanced under predictive SPEM conditions as opposed to the fixation and eyes-closed conditions, but performance was reduced under the random SPEM condition, thus reflecting an inverted-U relationship between the oculomotor task load and word recall performance. Subjects with high K-CVLT scores evidenced steady word recall performances, regardless of the type of oculomotor task performed. The concurrent oculomotor performance measured by velocity error did not differ significantly among the K-CVLT groups. However, the high-scoring subjects evidenced smaller phase errors under predictive SPEM conditions than did the low-scoring subjects; this suggests that different resource allocation strategies may be adopted, depending on individuals' working memory capacity.

  1. Relativistic effects on sixth group hydrides

    NASA Astrophysics Data System (ADS)

    Pisani, L.; Clementi, E.

    1994-08-01

    Dirac-Fock (DF) and Hartree-Fock (HF) calculations have been performed for the ground state configuration of the H2O, H2S, H2Se, H2Te, and H2Po molecules. Equilibrium geometries, atomization energies, and molecular orbitals energies are evaluated with both methods, compared and discussed with the help of population analysis and atomic orbital energies. Particular attention has been given to a qualitative understanding of the relativistic effects. Molecular spin-orbits corrections appear to be essential to a description of some in the sixth group hydrides set. A description of the relativistic computer program is presented elsewhere [L. Pisani and E. Clementi, J. Comput. Chem. (in press)].

  2. Effect of handedness on brain activity patterns and effective connectivity network during the semantic task of Chinese characters.

    PubMed

    Gao, Qing; Wang, Junping; Yu, Chunshui; Chen, Huafu

    2015-12-15

    Increasing efforts have been denoted to elucidating the effective connectivity (EC) among brain regions recruited by certain language task; however, it remains unclear the impact of handedness on the EC network underlying language processing. In particularly, this has not been investigated in Chinese language, which shows several differences from alphabetic language. This study thereby explored the functional activity patterns and the EC network during a Chinese semantic task based on functional MRI data of healthy left handers (LH) and right handers (RH). We found that RH presented a left lateralized activity pattern in cerebral cortex and a right lateralized pattern in cerebellum; while LH were less lateralized than RH in both cerebral and cerebellar areas. The conditional Granger causality method in deconvolved BOLD level further demonstrated more interhemispheric directional connections in LH than RH group, suggesting better bihemispheric coordination and increased interhemispheric communication in LH. Furthermore, we found significantly increased EC from right middle occipital gyrus to bilateral insula (INS) while decreased EC from left INS to left precentral gyrus in LH group comparing to RH group, implying that handedness may differentiate the causal relationship of information processing in integration of visual-spatial analysis and semantic word retrieval of Chinese characters.

  3. The masked semantic priming effect is task dependent: Reconsidering the automatic spreading activation process.

    PubMed

    de Wit, Bianca; Kinoshita, Sachiko

    2015-07-01

    Semantic priming effects are popularly explained in terms of an automatic spreading activation process, according to which the activation of a node in a semantic network spreads automatically to interconnected nodes, preactivating a semantically related word. It is expected from this account that semantic priming effects should be routinely observed when the prime identity is veiled from conscious awareness, but the extant literature on masked semantic priming effects is notoriously mixed. The authors use the same prime-target pairs in the lexical decision task and the semantic categorization task and show that although masking the prime eliminates the semantic priming effect in lexical decision, reliable semantic priming effects are observed with both masked and unmasked primes in the semantic categorization task. The authors explain this task dependence in terms of their account of semantic priming effects based on notions of evidence accumulation and source confusion and support their account by means of reaction time distribution analyses.

  4. Monte Carlo reference data sets for imaging research: Executive summary of the report of AAPM Research Committee Task Group 195.

    PubMed

    Sechopoulos, Ioannis; Ali, Elsayed S M; Badal, Andreu; Badano, Aldo; Boone, John M; Kyprianou, Iacovos S; Mainegra-Hing, Ernesto; McMillan, Kyle L; McNitt-Gray, Michael F; Rogers, D W O; Samei, Ehsan; Turner, Adam C

    2015-10-01

    The use of Monte Carlo simulations in diagnostic medical imaging research is widespread due to its flexibility and ability to estimate quantities that are challenging to measure empirically. However, any new Monte Carlo simulation code needs to be validated before it can be used reliably. The type and degree of validation required depends on the goals of the research project, but, typically, such validation involves either comparison of simulation results to physical measurements or to previously published results obtained with established Monte Carlo codes. The former is complicated due to nuances of experimental conditions and uncertainty, while the latter is challenging due to typical graphical presentation and lack of simulation details in previous publications. In addition, entering the field of Monte Carlo simulations in general involves a steep learning curve. It is not a simple task to learn how to program and interpret a Monte Carlo simulation, even when using one of the publicly available code packages. This Task Group report provides a common reference for benchmarking Monte Carlo simulations across a range of Monte Carlo codes and simulation scenarios. In the report, all simulation conditions are provided for six different Monte Carlo simulation cases that involve common x-ray based imaging research areas. The results obtained for the six cases using four publicly available Monte Carlo software packages are included in tabular form. In addition to a full description of all simulation conditions and results, a discussion and comparison of results among the Monte Carlo packages and the lessons learned during the compilation of these results are included. This abridged version of the report includes only an introductory description of the six cases and a brief example of the results of one of the cases. This work provides an investigator the necessary information to benchmark his/her Monte Carlo simulation software against the reference cases included here

  5. Dual task interference during walking: The effects of texting on situational awareness and gait stability.

    PubMed

    Lim, Jongil; Amado, Avelino; Sheehan, Leo; Van Emmerik, Richard E A

    2015-10-01

    Dual-task interference caused by mobile phone use while walking increases safety risks by increasing attentional and cognitive demands. Situational awareness, important for control of walking and safety, has been examined previously but measured only by the awareness of visually noteworthy objects in the environment or the number of times the person looked up from the phone. This study systematically investigated the effects of texting on situational awareness to different environments and its consequent impact on gait kinematics. Twenty healthy volunteers walked on a treadmill while texting and attending to visual tasks simultaneously. Gait parameters and situational awareness examined under dual-task conditions (walk and text or walk, text, and visual task) were compared with those of single-task conditions (text, walk or visual task only). The size of the visual field, display duration of the visual cue, and visual acuity demand were varied across the visual task conditions. About half of the visual cues provided during walking and texting were not perceived (48.3%) as compared to the visual task only condition. The magnitude of this loss of situational awareness was dependent upon the nature of visual information provided. While gait parameters were not different among visual task conditions, greater total medial-lateral excursion of the pelvis was observed in the walk and text condition compared to the walk only condition, showing the dual-task effects of texting on gait kinematics. The study provides further evidence of dual-task effects of texting on situational awareness as well as gait kinematics.

  6. What Do We Really Know about Cognitive Inhibition? Task Demands and Inhibitory Effects across a Range of Memory and Behavioural Tasks.

    PubMed

    Noreen, Saima; MacLeod, Malcolm D

    2015-01-01

    Our study explores inhibitory control across a range of widely recognised memory and behavioural tasks. Eighty-seven never-depressed participants completed a series of tasks designed to measure inhibitory control in memory and behaviour. Specifically, a variant of the selective retrieval-practice and the Think/No-Think tasks were employed as measures of memory inhibition. The Stroop-Colour Naming and the Go/No-Go tasks were used as measures of behavioural inhibition. Participants completed all 4 tasks. Task presentation order was counterbalanced across 3 separate testing sessions for each participant. Standard inhibitory forgetting effects emerged on both memory tasks but the extent of forgetting across these tasks was not correlated. Furthermore, there was no relationship between memory inhibition tasks and either of the main behavioural inhibition measures. At a time when cognitive inhibition continues to gain acceptance as an explanatory mechanism, our study raises fundamental questions about what we actually know about inhibition and how it is affected by the processing demands of particular inhibitory tasks.

  7. What Do We Really Know about Cognitive Inhibition? Task Demands and Inhibitory Effects across a Range of Memory and Behavioural Tasks

    PubMed Central

    Noreen, Saima; MacLeod, Malcolm D.

    2015-01-01

    Our study explores inhibitory control across a range of widely recognised memory and behavioural tasks. Eighty-seven never-depressed participants completed a series of tasks designed to measure inhibitory control in memory and behaviour. Specifically, a variant of the selective retrieval-practice and the Think/No-Think tasks were employed as measures of memory inhibition. The Stroop-Colour Naming and the Go/No-Go tasks were used as measures of behavioural inhibition. Participants completed all 4 tasks. Task presentation order was counterbalanced across 3 separate testing sessions for each participant. Standard inhibitory forgetting effects emerged on both memory tasks but the extent of forgetting across these tasks was not correlated. Furthermore, there was no relationship between memory inhibition tasks and either of the main behavioural inhibition measures. At a time when cognitive inhibition continues to gain acceptance as an explanatory mechanism, our study raises fundamental questions about what we actually know about inhibition and how it is affected by the processing demands of particular inhibitory tasks. PMID:26270470

  8. Role of accentuation in the selection/rejection task framing effect.

    PubMed

    Chen, Jing; Proctor, Robert W

    2017-04-01

    Procedure invariance is a basic assumption of rational theories of choice, however, it has been shown to be violated: Different response modes, or task frames, sometimes reveal opposite preferences. The current study focused on selection and rejection task frames, involving a unique type of problem with enriched and impoverished options, which has previously led to conflicting findings and theoretical explanations: the compatibility hypothesis (Shafir, 1993) and the accentuation hypothesis (Wedell, 1997). We examined the role of task frame by distinguishing these 2 hypotheses and evaluating the information-processing basis of the choices. Experiments conducted online (Experiments 1 and 3) and in-lab (Experiment 4 with eye-tracking technique) revealed a difference between the 2 task frames in the choice data (i.e., the task-framing effect) as a function of the relative attractiveness of the options. Also, this task-framing effect was not influenced by imposed time constraints (Experiments 5 and 6) and was similarly evident with a more direct measure for the option attractiveness (obtained in Experiment 7). Experiment 2, conducted in a lab setting with verbal-protocol requirements, yielded no task-framing effect, suggesting that a requirement to verbalize reasons for choice minimizes accentuation. With this exception, the choice data are in agreement with the accentuation hypothesis, and the combined findings in choice, decision time, task confusion, and eye-tracking data provide evidence of a basis in cognitive effort rather than motivation, as Wedell proposed. (PsycINFO Database Record

  9. THE EFFECTS OF SEX, TOPOLOGICAL STRUCTURE, AND TASK TYPE ON HYPERTEXT NAVIGATIONAL PERFORMANCE.

    PubMed

    Chang, Wen-Te; Chien, Yu-Hung

    2015-06-01

    Currently, almost all online materials use hyperlinks to provide users access to background, supplemental, or alternative information presented in context, greatly increasing the potential integration of information. However, a major problem is that people do not navigate hyperlinks effectively when the links become more topologically complex. Thus, identification of the variables that lead to navigational errors is necessary for the effective design of hyperlinks. Ninety-one participants (45 women, 46 men) were recruited for this experiment. All were college students and ranged in age from 19 to 23 yr. (M = 20.87, SD = 1.02). Navigational performance was examined in relation to sex, topological structure, and task type. A network topology with single-node task was superior to one with a linear topology under a single-node task condition, but equal to one with a linear topology under a multi-node task condition. Men navigated the linear topology with multi-node task and a network topology with a single-node task significantly faster than women, whereas no significant differences were observed under the other conditions. Sex interacted with topological structure and task type. This study extended the research in this domain by demonstrating an interactive effect among sex, topological structure, and task type on the navigational performance of users and can contribute to research regarding web page design.

  10. Automated recording of individual performance and hand preference during joystick-task acquisition in group-living bonnet macaques (Macaca radiata).

    PubMed

    Andrews, M W; Rosenblum, L A

    1994-12-01

    A microchip that provided a unique identification number was injected into each forearm of all 8 members of a bonnet macaque (Macaca radiata) social group. The group was then given computer-controlled joystick tasks of increasing difficulty. The identification number of the arm used on each trial was input into the computer and used to determine individual performance and hand preference in more than 23,000 trials. Three subjects reversed hand preference as task difficulty was increased over time. All subjects exhibited nearly exclusive use of a single hand on the most difficult task; 6 used the right hand, and 2 used the left. Daily patterns of joystick activity for the group members differed somewhat from that of our individually housed monkeys.

  11. The effect of goal setting on group performance: a meta-analysis.

    PubMed

    Kleingeld, Ad; van Mierlo, Heleen; Arends, Lidia

    2011-11-01

    Updating and extending the work of O'Leary-Kelly, Martocchio, and Frink (1994), with this meta-analysis on goal setting and group performance we show that specific difficult goals yield considerably higher group performance compared with nonspecific goals (d = 0.80 ± 0.35, k = 23 effect sizes). Moderately difficult and easy goals were also associated with performance benefits relative to nonspecific goals, but these effects were smaller. The overall effect size for all group goals was d = 0.56 ± 0.19 (k = 49). Unexpectedly, task interdependence, task complexity, and participation did not moderate the effect of group goals. Our inventory of multilevel goals in interdependent groups indicated that the effect of individual goals in groups on group performance was contingent upon the focus of the goal: "Egocentric" individual goals, aimed at maximizing individual performance, yielded a particularly negative group-performance effect (d = -1.75 ± 0.60, k = 6), whereas "groupcentric" goals, aimed at maximizing the individual contribution to the group's performance, showed a positive effect (d = 1.20 ± 1.03, k = 4). These findings demonstrate that group goals have a robust effect on group performance. Individual goals can also promote group performance but should be used with caution in interdependent groups. Future research might explore the role of multilevel goals for group performance in more detail. The striking lack of recent field studies in organizational settings that emerged from our brief review of trends in group goal-setting research should be taken into account when designing future studies in this domain.

  12. The effects of a simultaneous cognitive or motor task on the kinematics of walking in older fallers and non-fallers.

    PubMed

    Freire Júnior, Renato Campos; Porto, Jaqueline Mello; Marques, Nise Ribeiro; Magnani, Paola Errera; Abreu, Daniela Cristina Carvalho de

    2017-01-01

    Human gait has been widely investigated under dual-task conditions because it has been demonstrated to be an important way to uncover differences in gait biomechanics between older fallers and non-fallers. However, exactly how simultaneous tasks affect the kinematics of walking remains unclear. In the present study, gait kinematic properties of older fallers and non-fallers were compared under cognitive and motor dual-task conditions. The gait kinematic properties of interest were recorded under three different conditions: walking at preferred speed, walking when performing a cognitive task (naming animals), and walking when performing a motor task (transferring a coin from one pocket to the other). The following variables were analyzed: gait speed, cadence, stride time, step length, single support, stride time variability, and the dual-task cost. In addition, functional balance was evaluated by means of the Balance Evaluation - Systems Test (BESTest). Two-way repeated-measures ANOVAs revealed significant main effects of walking conditions. However, no significant main effects of group (fallers vs. non-fallers) and no significant interaction effects between group and walking condition were observed. The BESTest revealed that functional balance in fallers was worse than in non-fallers. The cognitive task leads to more significant changes in gait kinematics than does a motor task and the step length and stride time variability were variables more sensitive to that cognitive influence.

  13. Expectancy of Stress-Reducing Aromatherapy Effect and Performance on a Stress-Sensitive Cognitive Task

    PubMed Central

    Chamine, Irina; Oken, Barry S.

    2015-01-01

    Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress. Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude. Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention. PMID:25802539

  14. Effect of 72 h of Sleep Deprivation on the Iowa Gambling Task

    PubMed Central

    LIU, Lei; ZHOU, Renlai

    2016-01-01

    Introduction Sleep deprivation has detrimental effects on cognitive processes, including decision making. The present study investigated how 72 h of sleep deprivation influenced individual neural performance in the Iowa gambling task using event-related potential technology. Methods Eleven healthy male adults who participated in our study were randomized to be either in group with 72 h of social isolation condition or 72 h of sleep deprivation condition. Results Results showed that, in the feedback stage, the N250–400 amplitude was smaller in post-test than in pre-test for the sleep deprivation condition, especially in the frontal cortex. No significant difference between the pre-test and post-test condition was found in the social isolation condition. Conclusion These results suggested that 72 h of sleep deprivation affected an individual’s response to feedback stimuli, causing the individual to evaluate the stimuli slowly. PMID:28360813

  15. Effect of bandwidth knowledge of results on the learning of a grip force control task.

    PubMed

    Ugrinowitsch, Herbert; Ugrinowitsch, Alessandra Aguilar Coca; Benda, Rodolfo Novellino; Tertuliano, Ivan Wallan

    2010-12-01

    An experiment was conducted to investigate the persistence of the effect of "bandwidth knowledge of results (KR)" manipulated during the learning phase of performing a manual force-control task. The experiment consisted of two phases, an acquisition phase with the goal of maintaining 60% maximum force in 30 trials, and a second phase with the objective of maintaining 40% of maximum force in 20 further trials. There were four bandwidths of KR: when performance error exceeded 5, 10, or 15% of the target, and a control group (0% bandwidth). Analysis showed that 5, 10, and 15% bandwidth led to better performance than 0% bandwidth KR at the beginning of the second phase and persisted during the extended trials.

  16. Teachers' Situation-Specific Mastery Experiences: Teacher, Student Group and Lesson Effects

    ERIC Educational Resources Information Center

    Malmberg, Lars-Erik; Hagger, Hazel; Webster, Sophie

    2014-01-01

    Following a model on the cyclical nature of teacher ("trait") self-efficacy and context-, task- and situation-specific ("state") "mastery experiences" (TSSME), we investigated the variability and effects of lesson characteristics (e.g. lesson sequence), student group characteristics (e.g. proportion of students…

  17. Effects of Interlocutor Familiarity on Second Language Learning in Group Work

    ERIC Educational Resources Information Center

    Poteau, Christine E.

    2011-01-01

    Recent research in second language acquisition has focused on the effects of group work on learning by examining various factors (i.e., motivation, age, task, gender differences, etc.). One particular factor that has not been heavily investigated is interlocutor familiarity, which is at the forefront of the present study. Two separate classes (in…

  18. Effects of physical and mental task demands on cervical and upper limb muscle activity and physiological responses during computer tasks and recovery periods.

    PubMed

    Wang, Yuling; Szeto, Grace P Y; Chan, Chetwyn C H

    2011-11-01

    The present study examined the effects of physical and mental workload during computer tasks on muscle activity and physiological measures. Activity in cervical postural muscles and distal forearm muscles, heart rate and blood pressure were compared among three tasks and rest periods of 15 min each in an experimental study design. Fourteen healthy pain-free adults participated (7 males, mean age = 23.2 ± 3.0 years) and the tasks were: (1) copy-typing ("typing"), (2) typing at progressively faster speed ("pacing"), (3) mental arithmetic plus fast typing ("subtraction"). Typing task was performed first, followed by the other two tasks in a random order. Median muscle activity (50th percentile) was examined in 5-min intervals during each task and each rest period, and statistically significant differences in the "time" factor (within task) and time × task factors was found in bilateral cervical erector spinae and upper trapezius muscles. In contrast, distal forearm muscle activity did not show any significant differences among three tasks. All muscles showed reduced activity to about the baseline level within first 5 min of the rest periods. Heart rate and blood pressure showed significant differences during tasks compared to baseline, and diastolic pressure was significantly higher in the subtraction than pacing task. The results suggest that cervical postural muscles had higher reactivity than forearm muscles to high mental workload tasks, and cervical muscles were also more reactive to tasks with high physical demand compared to high mental workload. Heart rate and blood pressure seemed to respond similarly to high physical and mental workloads.

  19. When Compatibility Interferes with Group Effectiveness: Facilitation of Learning in Small Groups.

    ERIC Educational Resources Information Center

    Shaw, Marvin, E.; Webb, Jeaninne N.

    1982-01-01

    Examined whether compatible groups facilitate learning more than incompatible groups. Used peer groups to facilitate learning in college courses. Computed compatibility scores for pairs and four-person groups working together. Used examinations to measure peer group procedure effectiveness. Results did not indicate a positive relationship between…

  20. Effects of Group Size on Students Mathematics Achievement in Small Group Settings

    ERIC Educational Resources Information Center

    Enu, Justice; Danso, Paul Amoah; Awortwe, Peter K.

    2015-01-01

    An ideal group size is hard to obtain in small group settings; hence there are groups with more members than others. The purpose of the study was to find out whether group size has any effects on students' mathematics achievement in small group settings. Two third year classes of the 2011/2012 academic year were selected from two schools in the…

  1. The effects of environmental support and secondary tasks on visuospatial working memory.

    PubMed

    Lilienthal, Lindsey; Hale, Sandra; Myerson, Joel

    2014-10-01

    In the present experiments, we examined the effects of environmental support on participants' ability to rehearse locations and the role of such support in the effects of secondary tasks on memory span. In Experiment 1, the duration of interitem intervals and the presence of environmental support for visuospatial rehearsal (i.e., the array of possible memory locations) during the interitem intervals were both manipulated across four tasks. When support was provided, memory spans increased as the interitem interval durations increased, consistent with the hypothesis that environmental support facilitates rehearsal. In contrast, when environmental support was not provided, spans decreased as the duration of the interitem intervals increased, consistent with the hypothesis that visuospatial memory representations decay when rehearsal is impeded. In Experiment 2, the ratio of interitem interval duration to intertrial interval duration was kept the same on all four tasks, in order to hold temporal distinctiveness constant, yet forgetting was still observed in the absence of environmental support, consistent with the decay hypothesis. In Experiment 3, the effects of impeding rehearsal were compared to the effects of verbal and visuospatial secondary processing tasks. Forgetting of locations was greater when presentation of to-be-remembered locations alternated with the performance of a secondary task than when rehearsal was impeded by the absence of environmental support. The greatest forgetting occurred when a secondary task required the processing visuospatial information, suggesting that in addition to decay, both domain-specific and domain-general effects contribute to forgetting on visuospatial working memory tasks.

  2. Dynamic cortical networks of verbal and spatial working memory: effects of memory load and task practice.

    PubMed

    McEvoy, L K; Smith, M E; Gevins, A

    1998-01-01

    Working memory (WM), the ability to briefly retain and manipulate information in mind, is central to intelligent behavior. Here we take advantage of the high temporal resolution of electrophysiological measures to obtain a millisecond timescale view of the activity induced in distributed cortical networks by tasks that impose significant WM demands. We examined how these networks are affected by the type and amount of information to be remembered, and by the amount of task practice. Evoked potentials (EPs) were obtained from eight subjects performing spatial and verbal versions of a visual n-back WM task (n = 1, 2, 3) on each of three testing days. In well-trained subjects, WM tasks elicited transient responses reflecting different subcomponents of task processing, including transient (lasting 0.02-0.3 s) task-sensitive and load-sensitive EPs, as well as sustained responses (lasting 1-1.5 s), including the prestimulus Contingent Negative Variation (CNV), and post-stimulus frontal and parietal Slow Waves. The transient responses, with the exception of the P300, differed between the verbal and spatial task versions, and between trials with different response requirements. The P300 and the Slow Waves were not affected by task version but were affected by increased WM load. These results suggest that WM emerges from the formation of a dynamic cortical network linking task-specific processes with non-specific, capacity-limited, higher-order attentional processes. Practice effects on the EPs suggested that practice led to the development of a more effective cognitive strategy for dealing with lower-order aspects of task processing, but did not diminish demands made on higher order processes. Thus a simple WM task is shown to be composed of numerous elementary subsecond neural processes whose characteristics vary with type and amount of information being remembered, and amount of practice.

  3. The effect of task in deaf readers' graphophonological processes: a longitudinal study.

    PubMed

    Daigle, Daniel; Berthiaume, Rachel; Demont, Elisabeth

    2012-01-01

    This article reports on an investigation of graphophonological processes in deaf readers of French over a 1-year period. Deaf readers are known to have a phonological deficit compared to hearing peers, and conclusions from studies on this question are often conflicting. Among the different types of phonological processing, we can identify graphophonological processes based on correspondences between the oral and the written language. In this investigation, we evaluated graphophonemic and graphosyllabic processes using, in each case, two different tasks varying in their degree of cognitive constraints (CC- vs. CC+). Nineteen 11 year-old deaf students were compared to younger normal readers of the same reading level (RA, n = 17) and to normal readers of the same age (CA, n = 20). Two variables were considered in the analyses: accuracy and response latency. Results show that deaf readers do process written items at the graphophonological level and that graphophonological processes are related to reading ability. Also, results indicate main effects of task (CC- vs. CC+), time (T1 vs. T2), and group. In general, deaf participants' performances are comparable to those of RA and differ from those of CA. Results are discussed within the framework of the study of phonology in deaf readers and its relation to reading acquisition.

  4. Effects of different instructional constraints on task performance and emergence of coordination in children.

    PubMed

    Chow, Jia Yi; Koh, Michael; Davids, Keith; Button, Chris; Rein, Robert

    2014-01-01

    The objectives of this study were to determine the impact of different instructional constraints on standing board jump (sbj) performance in children and understand the underlying changes in emergent movement patterns. Two groups of novice participants were provided with either externally or internally focused attentional instructions during an intervention phase. Pre- and post-test sessions were undertaken to determine changes to performance and movement patterns. Thirty-six primary fourth-grade male students were recruited for this study and randomly assigned to either an external, internal focus or control group. Different instructional constraints with either an external focus (image of the achievement) or an internal focus (image of the act) were provided to the participants. Performance scores (jump distances), and data from key kinematic (joint range of motion, ROM) and kinetic variables (jump impulses) were collected. Instructional constraints with an emphasis on an external focus of attention were generally more effective in assisting learners to improve jump distances. Intra-individual analyses highlighted how enhanced jump distances for successful participants may be concomitant with specific changes to kinematic and kinetic variables. Larger joint ROM and adjustment to a comparatively larger horizontal impulse to a vertical impulse were observed for more successful participants at post-test performance. From a constraints-led perspective, the inclusion of instructional constraints encouraging self-adjustments in the control of movements (i.e., image of achievement) had a beneficial effect on individuals performing the standing broad jump task. However, the advantage of using an external focus of attentional instructions could be task- and individual-specific.

  5. Designing and Fostering Effective Online Group Projects

    ERIC Educational Resources Information Center

    Scherling, Sarah E.

    2011-01-01

    Collaborative learning is a hallmark of adult education and a popular instructional strategy. For over a decade, as an educator of adult learners, the author has integrated group work into courses. Group projects require the contribution and evaluation from all group members and often reflect a collective grade at the end of the project. However,…

  6. Enhancing the Effectiveness of Work Groups and Teams.

    PubMed

    Kozlowski, Steve W J; Ilgen, Daniel R

    2006-12-01

    Teams of people working together for a common purpose have been a centerpiece of human social organization ever since our ancient ancestors first banded together to hunt game, raise families, and defend their communities. Human history is largely a story of people working together in groups to explore, achieve, and conquer. Yet, the modern concept of work in large organizations that developed in the late 19th and early 20th centuries is largely a tale of work as a collection of individual jobs. A variety of global forces unfolding over the last two decades, however, has pushed organizations worldwide to restructure work around teams, to enable more rapid, flexible, and adaptive responses to the unexpected. This shift in the structure of work has made team effectiveness a salient organizational concern. Teams touch our lives everyday and their effectiveness is important to well-being across a wide range of societal functions. There is over 50 years of psychological research-literally thousands of studies-focused on understanding and influencing the processes that underlie team effectiveness. Our goal in this monograph is to sift through this voluminous literature to identify what we know, what we think we know, and what we need to know to improve the effectiveness of work groups and teams. We begin by defining team effectiveness and establishing the conceptual underpinnings of our approach to understanding it. We then turn to our review, which concentrates primarily on topics that have well-developed theoretical and empirical foundations, to ensure that our conclusions and recommendations are on firm footing. Our review begins by focusing on cognitive, motivational/affective, and behavioral team processes-processes that enable team members to combine their resources to resolve task demands and, in so doing, be effective. We then turn our attention to identifying interventions, or "levers," that can shape or align team processes and thereby provide tools and

  7. Using the Hand Laterality Judgement Task to Assess Motor Imagery: A Study of Practice Effects in Repeated Measurements

    ERIC Educational Resources Information Center

    Boonstra, Anne M.; de Vries, Sjoerd J.; Veenstra, Evelien; Tepper, Marga; Feenstra, Wya; Otten, Egbert

    2012-01-01

    The aim of this study was to determine whether there is a practice effect on the Hand Laterality Judgement Task (HLJT). The HLJT task is a mental rotation task that can be used to assess motor imagery ability in stroke patients. Thirty-three healthy individuals performed the HLJT and two control tasks twice at a 3-week interval. Differences in the…

  8. The Effects of Art History-Enriched Art Therapy on Anxiety, Time on Task, and Art Product Quality.

    ERIC Educational Resources Information Center

    Miller, Carol L.

    1993-01-01

    Investigated effects of art history enrichment of art therapy task on anxiety, time on task, and art product quality among 13 chronic adult psychiatric day hospital patients. Results indicated art history enrichment task reduced anxiety and increased time on task. Art organization level tended toward significant increase compared with control…

  9. Effects of Academic Response Rates on Time-on-Task in the Classroom for Students at Academic and Behavioral Risk

    ERIC Educational Resources Information Center

    Gilbertson, Donna; Duhon, Gary; Witt, Joseph C.; Dufrene, Brad

    2008-01-01

    This study examined the effects of task difficulty on on-task behavior for four students exhibiting low levels of math performance and on-task behavior. Curriculum-based assessments were conducted with each student to define the difficulty level of math tasks for each student based on the individual's rate of accurate performance on computational…

  10. The effects of practice on the concurrent performance of a speech and postural task in persons with Parkinson disease and healthy controls.

    PubMed

    Foreman, K Bo; Sondrup, Stuart; Dromey, Christopher; Jarvis, Eon; Nissen, Shawn; Dibble, Leland E

    2013-01-01

    Purpose. Persons with Parkinson disease (PD) demonstrate deficits in motor learning as well as bidirectional interference (the performance of one task concurrently interferes with the performance of another task) during dual-task performance. Few studies have examined the practice dosages necessary for behavioral change in rehabilitation relevant tasks. Therefore, to compare the effects of age and PD on motor learning during dual-task performance, this pilot study examined persons with PD as well as neurologically healthy participants during concurrent performance of postural and speaking tasks. Methods. Seven persons with PD and 7 healthy age-matched and 10 healthy young control subjects were tested in a motion capture facility. Task performances were performed concurrently and recorded during 3 time periods (acquisition (beginning and ending), 48-hour retention, and 1-week retention). Postural control and speech articulatory acoustic variables were measured. Results. Healthy young participants consistently performed better than other groups on all measured postural and speech variables. Healthy young participants showed decreased variability at retention, while persons with PD and healthy age-matched controls were unable to consistently improve their performance as a result of practice. No changes were noted in the speech variables. Conclusion. The lack of consistent changes in motor performance in any of the tasks, except in the healthy young group, suggests a decreased efficiency of motor learning in the age-matched and PD groups and argues for increased practice dosages during balance training.

  11. The Effects of Practice on the Concurrent Performance of a Speech and Postural Task in Persons with Parkinson Disease and Healthy Controls

    PubMed Central

    Foreman, K. Bo; Sondrup, Stuart; Dromey, Christopher; Jarvis, Eon; Nissen, Shawn; Dibble, Leland E.

    2013-01-01

    Purpose. Persons with Parkinson disease (PD) demonstrate deficits in motor learning as well as bidirectional interference (the performance of one task concurrently interferes with the performance of another task) during dual-task performance. Few studies have examined the practice dosages necessary for behavioral change in rehabilitation relevant tasks. Therefore, to compare the effects of age and PD on motor learning during dual-task performance, this pilot study examined persons with PD as well as neurologically healthy participants during concurrent performance of postural and speaking tasks. Methods. Seven persons with PD and 7 healthy age-matched and 10 healthy young control subjects were tested in a motion capture facility. Task performances were performed concurrently and recorded during 3 time periods (acquisition (beginning and ending), 48-hour retention, and 1-week retention). Postural control and speech articulatory acoustic variables were measured. Results. Healthy young participants consistently performed better than other groups on all measured postural and speech variables. Healthy young participants showed decreased variability at retention, while persons with PD and healthy age-matched controls were unable to consistently improve their performance as a result of practice. No changes were noted in the speech variables. Conclusion. The lack of consistent changes in motor performance in any of the tasks, except in the healthy young group, suggests a decreased efficiency of motor learning in the age-matched and PD groups and argues for increased practice dosages during balance training. PMID:23841022

  12. A key role for experimental task performance: effects of math talent, gender and performance on the neural correlates of mental rotation.

    PubMed

    Hoppe, Christian; Fliessbach, Klaus; Stausberg, Sven; Stojanovic, Jelena; Trautner, Peter; Elger, Christian E; Weber, Bernd

    2012-02-01

    The neurophysiological mechanisms underlying superior cognitive performance are a research area of high interest. The majority of studies on the brain-performance relationship assessed the effects of capability-related group factors (e.g. talent, gender) on task-related brain activations while only few studies examined the effect of the inherent experimental task performance factor. In this functional MRI study, we combined both approaches and simultaneously assessed the effects of three relatively independent factors on the neurofunctional correlates of mental rotation in same-aged adolescents: math talent (gifted/controls: 17/17), gender (male/female: 16/18) and experimental task performance (median split on accuracy; high/low: 17/17). Better experimental task performance of mathematically gifted vs. control subjects and male vs. female subjects validated the selected paradigm. Activation of the inferior parietal lobule (IPL) was identified as a common effect of mathematical giftedness, gender and experimental task performance. However, multiple linear regression analyses (stepwise) indicated experimental task performance as the only predictor of parietal activations. In conclusion, increased activation of the IPL represents a positive neural correlate of mental rotation performance, irrespective of but consistent with the obtained neurocognitive and behavioral effects of math talent and gender. As experimental performance may strongly affect task-related activations this factor needs to be considered in capability-related group comparison studies on the brain-performance relationship.

  13. A group-based tasks allocation algorithm for the optimization of long leave opportunities in academic departments

    NASA Astrophysics Data System (ADS)

    Eyono Obono, S. D.; Basak, Sujit Kumar

    2011-12-01

    The general formulation of the assignment problem consists in the optimal allocation of a given set of tasks to a workforce. This problem is covered by existing literature for different domains such as distributed databases, distributed systems, transportation, packets radio networks, IT outsourcing, and teaching allocation. This paper presents a new version of the assignment problem for the allocation of academic tasks to staff members in departments with long leave opportunities. It presents the description of a workload allocation scheme and its algorithm, for the allocation of an equitable number of tasks in academic departments where long leaves are necessary.

  14. The psychosocial and health effects of workplace reorganisation. 2. A systematic review of task restructuring interventions

    PubMed Central

    Bambra, Clare; Egan, Matt; Thomas, Sian; Petticrew, Mark; Whitehead, Margaret

    2007-01-01

    Objective To systematically review the health and psychosocial effects (with reference to the demand–control–support model) of changes to the work environment brought about by task structure work reorganisation, and to determine whether those effects differ for different socioeconomic groups. Design Systematic review (QUORUM) of experimental and quasi‐experimental studies (any language) reporting health and psychosocial effects of such interventions. Data sources Seventeen electronic databases (medical, social science and economic), bibliographies and expert contacts. Results Nineteen studies were reviewed. Some task‐restructuring interventions failed to alter the psychosocial work environment significantly, and so could not be expected to have a measurable effect on health. Those that increased demand and decreased control tended to have an adverse effect on health, while those that decreased demand and increased control resulted in improved health, although some effects were minimal. Increases in workplace support did not appear to mediate this relationship. Conclusion This systematic review suggests that task‐restructuring interventions that increase demand or decrease control adversely affect the health of employees, in line with observational research. It lends support to policy initiatives such as the recently enforced EU directive on participation at work, which aims to increase job control and autonomy. PMID:18000123

  15. Clinical implementation of an electron monitor unit dosimetry system based on task group 71 report and a commercial calculation program

    PubMed Central

    Xu, Huijun; Guerrero, Mariana; Chen, Shifeng; Yang, Xiaocheng; Prado, Karl; Schinkel, Colleen

    2016-01-01

    Many clinics still use monitor unit (MU) calculations for electron treatment planning and/or quality assurance (QA). This work (1) investigates the clinical implementation of a dosimetry system including a modified American Association of Physicists in Medicine-task group-71 (TG-71)-based electron MU calculation protocol (modified TG-71 electron [mTG-71E] and an independent commercial calculation program and (2) provides the practice recommendations for clinical usage. Following the recently published TG-71 guidance, an organized mTG-71E databook was developed to facilitate data access and subsequent MU computation according to our clinical need. A recently released commercial secondary calculation program – Mobius3D (version 1.5.1) Electron Quick Calc (EQC) (Mobius Medical System, LP, Houston, TX, USA), with inherent pencil beam algorithm and independent beam data, was used to corroborate the calculation results. For various setups, the calculation consistency and accuracy of mTG-71E and EQC were validated by their cross-comparison and the ion chamber measurements in a solid water phantom. Our results show good agreement between mTG-71E and EQC calculations, with average 2% difference. Both mTG-71E and EQC calculations match with measurements within 3%. In general, these differences increase with decreased cutout size, increased extended source to surface distance, and lower energy. It is feasible to use TG71 and Mobius3D clinically as primary and secondary electron MU calculations or vice versa. We recommend a practice that only requires patient-specific measurements in rare cases when mTG-71E and EQC calculations differ by 5% or more. PMID:28144112

  16. Clinical implementation of an electron monitor unit dosimetry system based on task group 71 report and a commercial calculation program.

    PubMed

    Xu, Huijun; Guerrero, Mariana; Chen, Shifeng; Yang, Xiaocheng; Prado, Karl; Schinkel, Colleen

    2016-01-01

    Many clinics still use monitor unit (MU) calculations for electron treatment planning and/or quality assurance (QA). This work (1) investigates the clinical implementation of a dosimetry system including a modified American Association of Physicists in Medicine-task group-71 (TG-71)-based electron MU calculation protocol (modified TG-71 electron [mTG-71E] and an independent commercial calculation program and (2) provides the practice recommendations for clinical usage. Following the recently published TG-71 guidance, an organized mTG-71E databook was developed to facilitate data access and subsequent MU computation according to our clinical need. A recently released commercial secondary calculation program - Mobius3D (version 1.5.1) Electron Quick Calc (EQC) (Mobius Medical System, LP, Houston, TX, USA), with inherent pencil beam algorithm and independent beam data, was used to corroborate the calculation results. For various setups, the calculation consistency and accuracy of mTG-71E and EQC were validated by their cross-comparison and the ion chamber measurements in a solid water phantom. Our results show good agreement between mTG-71E and EQC calculations, with average 2% difference. Both mTG-71E and EQC calculations match with measurements within 3%. In general, these differences increase with decreased cutout size, increased extended source to surface distance, and lower energy. It is feasible to use TG71 and Mobius3D clinically as primary and secondary electron MU calculations or vice versa. We recommend a practice that only requires patient-specific measurements in rare cases when mTG-71E and EQC calculations differ by 5% or more.

  17. The effects of 7.5% carbon dioxide inhalation on task performance in healthy volunteers.

    PubMed

    Diaper, Alison; Nutt, David J; Munafò, Marcus R; White, Joanna L; Farmer, Eric W; Bailey, Jayne E

    2012-04-01

    Studies have shown that anxiety can positively or negatively affect performance with respect to focusing of attention or distractibility, subjective workload and effort (Humphreys and Revelle, 1984). The inhalation of carbon dioxide (CO(2)) is associated with physiological and psychological effects of anxiety (Bailey et al., 2005) but its effects on performance have rarely been reported. The studies reported here looked at the effects of CO(2) inhalation on physiological and subjective measures and performance on two tasks. Eight healthy male participants completed a tracking task with a reaction time component, and 12 healthy participants (six male) completed a complex target identification task. Tasks were performed during 20-min inhalations of 7.5% CO(2)/21% O(2)/71.5% N(2) mixture or medical air. Continuous heart rate and blood pressure measures were taken, in addition to subjective measures of mood and workload. In comparison with air, CO(2) increased heart rate and blood pressure, increased subjective scores of panic, anxiety, fear, and tension, and reduced subjective scores of relaxation and happiness. Attention was focussed when inhaling CO(2) during the simple task, and central demand was greater when inhaling CO(2) during the complex task. Therefore, inhalation of 7.5% CO(2) produces effects on task performance which are consistent with anxiety.

  18. Effects of EVA spacesuit glove on grasping and pinching tasks

    NASA Astrophysics Data System (ADS)

    Appendino, Silvia; Battezzato, Alessandro; Chen Chen, Fai; Favetto, Alain; Mousavi, Mehdi; Pescarmona, Francesco

    2014-03-01

    The human hand has a wide range of degrees of freedom, allowing a great variety of movements, and is also one of the most sensitive parts of the human body. Due to these characteristics, it is the most important tool for astronauts to perform extravehicular activities (EVA). However, astronauts must wear mandatory EVA equipment to be protected from the harsh conditions in space and this strongly reduces hand performance, in particular as regards dexterity, tactile perception, mobility and fatigue. Several studies have been conducted to determine the influence of the EVA glove on manual capabilities, both in the past and more recently. This study presents experimental data regarding the performance decline occurring in terms of force and fatigue in the execution of grasping and pinching tasks when wearing an EVA glove, in pressurized and unpressurized conditions, compared with barehanded potential. Results show that wearing the unpressurized EVA glove hinders grip and lateral pinch performances, dropping exerted forces to about 50-70%, while it barely affects two- and three-finger pinch performances. On the other hand, wearing the pressurized glove worsens performances in all cases, reducing forces to about 10-30% of barehanded potential. The results are presented and compared with the previous literature.

  19. Toward Effective Group Formation in Computer-Supported Collaborative Learning

    ERIC Educational Resources Information Center

    Sadeghi, Hamid; Kardan, Ahmad A.

    2016-01-01

    Group formation task as a starting point for computer-supported collaborative learning plays a key role in achieving pedagogical goals. Various approaches have been reported in the literature to address this problem, but none have offered an optimal solution. In this research, an online learning environment was modeled as a weighted undirected…

  20. Effects of Attribute Identification Pretraining on Rule Effects in Attribute Identification Transfer Tasks. Technical Report No. 278.

    ERIC Educational Resources Information Center

    Ingison, Linda J.

    An attempt was made to reduce or eliminate rule effects in attribute identification (AI) tasks through AI pretraining. Thirty-six 12th-grade volunteers received 0, 4, or 8 AI problems prior to transfer to a final AI task. Results showed that even at the highest level of pretraining, rule effects were present at transfer. These findings were…

  1. Action Effects and Task Knowledge: The Influence of Anticipatory Priming on the Identification of Task-Related Stimuli in Experts

    PubMed Central

    Land, William M.

    2016-01-01

    The purpose of the present study was to examine the extent to which anticipation of an action’s perceptual effect primes identification of task-related stimuli. Specifically, skilled (n = 16) and novice (n = 24) tennis players performed a choice-reaction time (CRT) test in which they identified whether the presented stimulus was a picture of a baseball bat or tennis racket. Following their response, auditory feedback associated with either baseball or tennis was presented. The CRT test was performed in blocks in which participants predictably received the baseball sound or tennis sound irrespective of which stimulus picture was displayed. Results indicated that skilled tennis players responded quicker to tennis stimuli when the response was predictably followed by the tennis auditory effect compared to the baseball auditory effect. These findings imply that, within an individual’s area of expertise, domain-relevant knowledge is primed by anticipation of an action’s perceptual effect, thus allowing the cognitive system to more quickly identify environmental information. This finding provides a more complete picture of the influence that anticipation can have on the cognitive-motor system. No differences existed for novices. PMID:27272987

  2. Comparing the Frequency Effect Between the Lexical Decision and Naming Tasks in Chinese.

    PubMed

    Gao, Xin-Yu; Li, Meng-Feng; Chou, Tai-Li; Wu, Jei-Tun

    2016-04-01

    In psycholinguistic research, the frequency effect can be one of the indicators for eligible experimental tasks that examine the nature of lexical access. Usually, only one of those tasks is chosen to examine lexical access in a study. Using two exemplar experiments, this paper introduces an approach to include both the lexical decision task and the naming task in a study. In the first experiment, the stimuli were Chinese characters with frequency and regularity manipulated. In the second experiment, the stimuli were switched to Chinese two-character words, in which the word frequency and the regularity of the leading character were manipulated. The logic of these two exemplar experiments was to explore some important issues such as the role of phonology on recognition by comparing the frequency effect between both the tasks. The results revealed different patterns of lexical access from those reported in the alphabetic systems. The results of Experiment 1 manifested a larger frequency effect in the naming task as compared to the LDT, when the stimuli were Chinese characters. And it is noteworthy that, in Experiment 1, when the stimuli were regular Chinese characters, the frequency effect observed in the naming task was roughly equivalent to that in the LDT. However, a smaller frequency effect was shown in the naming task as compared to the LDT, when the stimuli were switched to Chinese two-character words in Experiment 2. Taking advantage of the respective demands and characteristics in both tasks, researchers can obtain a more complete and precise picture of character/word recognition.

  3. Intracranial stereotactic positioning systems: Report of the American Association of Physicists in Medicine Radiation Therapy Committee Task Group No. 68

    SciTech Connect

    Lightstone, A.W.; Benedict, Stanley H.; Bova, Frank J.; Solberg, Timothy D.; Stern, Robin L.

    2005-07-15

    the appropriate tests as well as recommendations to help establish the required frequency of testing are provided. Because of the broad scope of different systems, it is important that both the manufacturer and user rigorously critique the system and set QA tests appropriate to the particular device and its possible weaknesses. Major recommendations of the Task Group include: introduction of a new nomenclature for reporting repositioning accuracy; comprehensive analysis of patient characteristics that might adversely affect positioning accuracy; performance of testing immediately before each treatment to establish that there are no gross positioning errors; a general request to the Medical Physics community for improved QA tools; implementation of weekly portal imaging (perhaps cone beam CT in the future) as a method of tracking fractionated patients (as per TG 40); and periodic routine reviews of positioning accuracy.

  4. Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks

    PubMed Central

    de Hoyo, Moisés; Sañudo, Borja; Carrasco, Luis; Domínguez-Cobo, Sergio; Mateo-Cortes, Jesús; Cadenas-Sánchez, María Monserrat; Nimphius, Sophia

    2015-01-01

    This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years) volunteered to participate in this study. Participants were allocated into either the traditional training (TT) group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT) group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5–8 sets with 8 repetitions) and relative intensity (the load that maximized power (Pmax)) over the period of six weeks. Speed (10 m and 20 m), countermovement jump height (CMJH), 20 m change of direction ability (COD) and strength during a maximal voluntary isometric contraction (MVIC) were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004) was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: −0.17 0.27 s vs. HFT: −0.11 0.10 s), CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm) and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N) in both groups (p < 0.05). However, significant differences only occurred in the 20 m sprint time in the TT group (−0.04 0.12 s; p = 0.04). In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance. PMID:26557200

  5. Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks.

    PubMed

    de Hoyo, Moisés; Sañudo, Borja; Carrasco, Luis; Domínguez-Cobo, Sergio; Mateo-Cortes, Jesús; Cadenas-Sánchez, María Monserrat; Nimphius, Sophia

    2015-09-29

    This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years) volunteered to participate in this study. Participants were allocated into either the traditional training (TT) group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT) group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5-8 sets with 8 repetitions) and relative intensity (the load that maximized power (Pmax)) over the period of six weeks. Speed (10 m and 20 m), countermovement jump height (CMJH), 20 m change of direction ability (COD) and strength during a maximal voluntary isometric contraction (MVIC) were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004) was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: -0.17 0.27 s vs. HFT: -0.11 0.10 s), CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm) and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N) in both groups (p < 0.05). However, significant differences only occurred in the 20 m sprint time in the TT group (-0.04 0.12 s; p = 0.04). In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance.

  6. Effects of Modality on Response Word Association Tasks.

    ERIC Educational Resources Information Center

    Reynolds, Richard J.

    How the mode of input of stimuli affects the quality or type of response was studied by comparing the number of paradigmatic responses and syntagmatic responses to both orally and visually presented stimulus words. The following groups, totaling 194 subjects, were involved in four experiments: (1) 18 institutionalized disturbed adolescents, (2) 96…

  7. Effects of Experience and Task Difficulty on Event-Related Potentials

    DTIC Science & Technology

    1989-10-13

    MEDICAL RESEARCH AND DEVELOPMENT COMMAND BETHESDA, MARYLAND EFFECTS OF EXPERIENCE AN TASK DIFICILTY * ~ON EVENT-RELATM POTERMALS David A. Kobus Keren B...by the Naval Medical Research and Development : omand , Department of the Navy, under work unit MR.001-6037. The views expressed in this article are...Effects of experience and task difficulty on event-related potentials 12. PERSONAL AUTHOR(S) Kobus, David A. & Stashower, Keren 3a. TYPE OF REPORT

  8. Cerebral mechanisms underlying the effects of music during a fatiguing isometric ankle-dorsiflexion task.

    PubMed

    Bigliassi, Marcelo; Karageorghis, Costas I; Nowicky, Alexander V; Orgs, Guido; Wright, Michael J

    2016-10-01

    The brain mechanisms by which music-related interventions ameliorate fatigue-related symptoms during the execution of fatiguing motor tasks are hitherto under-researched. The objective of the present study was to investigate the effects of music on brain electrical activity and psychophysiological measures during the execution of an isometric fatiguing ankle-dorsiflexion task performed until the point of volitional exhaustion. Nineteen healthy participants performed two fatigue tests at 40% of maximal voluntary contraction while listening to music or in silence. Electrical activity in the brain was assessed by use of a 64-channel EEG. The results indicated that music downregulated theta waves in the frontal, central, and parietal regions of the brain during exercise. Music also induced a partial attentional switching from associative thoughts to task-unrelated factors (dissociative thoughts) during exercise, which led to improvements in task performance. Moreover, participants experienced a more positive affective state while performing the isometric task under the influence of music.

  9. Semantic priming in the prime task effect: evidence of automatic semantic processing of distractors.

    PubMed

    Marí-Beffa, P; Fuentes, L J; Catena, A; Houghton, G

    2000-06-01

    The automaticity of the semantic processing of words has been questioned because of the reduction of semantic priming when the prime word is processed nonsemantically--for example, in letter search (the prime task effect). In two experiments, prime distractor words produced semantic priming in a subsequent lexical decision task, but with the direction of priming (positive or negative) depending on the prime task. Lexico-semantic tasks produced negative semantic priming, whereas letter search produced positive semantic priming. These results are discussed in terms of task-based inhibition. We argue that, given the results from the distractors, the absence of semantic priming does not indicate an absence of semantic activation but reflects the action of control processes on prepotent responses when less practiced responses are needed.

  10. Status Report on Activities of the Systems Assessment Task Force, OECD-NEA Expert Group on Accident Tolerant Fuels for LWRs

    SciTech Connect

    Bragg-Sitton, Shannon Michelle

    2015-09-01

    The Organization for Economic Cooperation and Development /Nuclear Energy Agency (OECD/NEA) Nuclear Science Committee approved the formation of an Expert Group on Accident Tolerant Fuel (ATF) for LWRs (EGATFL) in 2014. Chaired by Kemal Pasamehmetoglu, INL Associate Laboratory Director for Nuclear Science and Technology, the mandate for the EGATFL defines work under three task forces: (1) Systems Assessment, (2) Cladding and Core Materials, and (3) Fuel Concepts. Scope for the Systems Assessment task force includes definition of evaluation metrics for ATF, technology readiness level definition, definition of illustrative scenarios for ATF evaluation, parametric studies, and selection of system codes. The Cladding and Core Materials and Fuel Concepts task forces will identify gaps and needs for modeling and experimental demonstration; define key properties of interest; identify the data necessary to perform concept evaluation under normal conditions and illustrative scenarios; identify available infrastructure (internationally) to support experimental needs; and make recommendations on priorities. Where possible, considering proprietary and other export restrictions (e.g., International Traffic in Arms Regulations), the Expert Group will facilitate the sharing of data and lessons learned across the international group membership. The Systems Assessment Task Force is chaired by Shannon Bragg-Sitton (INL), while the Cladding Task Force will be chaired by a representative from France (Marie Moatti, Electricite de France [EdF]) and the Fuels Task Force will be chaired by a representative from Japan (Masaki Kurata, Japan Atomic Energy Agency [JAEA]). This report provides an overview of the Systems Assessment Task Force charter and status of work accomplishment.

  11. Walking & Talking: Dual-Task Effects on Street Crossing Behavior in Older Adults

    PubMed Central

    Neider, Mark B.; Gaspar, John G.; McCarley, Jason S.; Crowell, James A.; Kaczmarski, Henry; Kramer, Arthur F.

    2013-01-01

    The ability to perform multiple tasks simultaneously has become increasingly important as technologies such as cell phones and portable music players have become more common. In the current study, we examined dual-task costs in older and younger adults using a simulated street crossing task constructed in an immersive virtual environment with an integrated treadmill so that participants could walk as they would in the real world. Participants were asked to cross simulated streets of varying difficulty while either undistracted, listening to music, or conversing on a cell phone. Older adults were more vulnerable to dual-task impairments than younger adults when the crossing task was difficult; dual-task costs were largely absent in the younger adult group. Performance costs in older adults were primarily reflected in timeout rates. When conversing on a cell phone older adults were less likely to complete their crossing compared to when listening to music or undistracted. Analysis of time spent next to the street prior to each crossing, where participants were presumably analyzing traffic patterns and making decisions regarding when to cross, revealed that older adults took longer than younger adults to initiate their crossing, and that this difference was exacerbated during cell phone conversation, suggesting impairments in cognitive planning processes. Our data suggest that multi-tasking costs may be particularly dangerous for older adults even during everyday activities such as crossing the street. PMID:21401262

  12. Task- and age-dependent effects of visual stimulus properties on children's explicit numerosity judgments.

    PubMed

    Defever, Emmy; Reynvoet, Bert; Gebuis, Titia

    2013-10-01

    Researchers investigating numerosity processing manipulate the visual stimulus properties (e.g., surface). This is done to control for the confound between numerosity and its visual properties and should allow the examination of pure number processes. Nevertheless, several studies have shown that, despite different visual controls, visual cues remained to exert their influence on numerosity judgments. This study, therefore, investigated whether the impact of the visual stimulus manipulations on numerosity judgments is dependent on the task at hand (comparison task vs. same-different task) and whether this impact changes throughout development. In addition, we examined whether the influence of visual stimulus manipulations on numerosity judgments plays a role in the relation between performance on numerosity tasks and mathematics achievement. Our findings confirmed that the visual stimulus manipulations affect numerosity judgments; more important, we found that these influences changed with increasing age and differed between the comparison and the same-different tasks. Consequently, direct comparisons between numerosity studies using different tasks and age groups are difficult. No meaningful relationship between the performance on the comparison and same-different tasks and mathematics achievement was found in typically developing children, nor did we find consistent differences between children with and without mathematical learning disability (MLD).

  13. Task breakdown

    NASA Technical Reports Server (NTRS)

    Pavlich, Jane

    1990-01-01

    The topics concerning the Center for Space Construction (CSC) space construction breakdown structure are presented in viewgraph form. It is concluded that four components describe a task -- effecting, information gathering, analysis, and regulation; uncertainties effect the relative amount of information gathering and analysis that occurs; and that task timing requirements drive the 'location in time' of cognition.

  14. Behavioral pharmacology of the odor span task: Effects of flunitrazepam, ketamine, methamphetamine and methylphenidate.

    PubMed

    Galizio, Mark; April, Brooke; Deal, Melissa; Hawkey, Andrew; Panoz-Brown, Danielle; Prichard, Ashley; Bruce, Katherine

    2016-11-01

    The Odor Span Task is an incrementing non-matching-to-sample procedure that permits the study of behavior under the control of multiple stimuli. Rats are exposed to a series of odor stimuli and selection of new stimuli is reinforced. Successful performance thus requires remembering which stimuli have previously been presented during a given session. This procedure has been frequently used in neurobiological studies as a rodent model of working memory; however, only a few studies have examined the effects of drugs on performance in this task. The present experiments explored the behavioral pharmacology of a modified version of the Odor Span Task by determining the effects of stimulant drugs methylphenidate and methamphetamine, NMDA antagonist ketamine, and positive GABAA modulator flunitrazepam. All four drugs produced dose-dependent impairment of performances on the Odor Span Task, but for methylphenidate and methamphetamine, these occurred only at doses that had similar effects on performance of a simple odor discrimination. Generally, these disruptions were based on omission of responding at the effective doses. The effects of ketamine and flunitrazepam were more selective in some rats. That is, some rats tested under flunitrazepam and ketamine showed decreases in accuracy on the Odor Span Task at doses that did not affect simple discrimination performance. These selective effects indicate disruption of within-session stimulus control. Overall, these findings support the potential of the Odor Span Task as a baseline for the behavioral pharmacological analysis of remembering.

  15. Motoneuronal TASK channels contribute to immobilizing effects of inhalational general anesthetics

    PubMed Central

    Lazarenko, Roman M.; Willcox, Sarah C.; Shu, Shaofang; Berg, Allison P.; Jevtovic-Todorovic, Vesna; Talley, Edmund M.; Chen, Xiangdong; Bayliss, Douglas A.

    2010-01-01

    General anesthetics cause sedation, hypnosis and immobilization via central nervous system mechanisms that remain incompletely understood; contributions of particular anesthetic targets in specific neural pathways remain largely unexplored. Among potential molecular targets for mediating anesthetic actions, the TASK subgroup (TASK-1, K2P3.1& TASK-3, K2P9.1) of background K+ channels are appealing candidates since they are expressed in CNS sites relevant to anesthetic actions and activated by clinically relevant concentrations of inhaled anesthetics. Here, we used global and conditional TASK channel single and double subunit knockout mice to demonstrate definitively that TASK channels account for motoneuronal anesthetic-activated K+ currents and to test their contributions to sedative, hypnotic and immobilizing anesthetic actions. In motoneurons from all knockout mice lines, TASK-like currents were reduced and cells were less sensitive to hyperpolarizing effects of halothane and isoflurane. In an immobilization assay, higher concentrations of both halothane and isoflurane were required to render TASK knockout animals unresponsive to a tail pinch; in assays of sedation (loss of movement) and hypnosis (loss-of-righting reflex), TASK knockout mice showed a modest decrease in sensitivity, and only for halothane. In conditional knockout mice, with TASK channel deletion restricted to cholinergic neurons, immobilizing actions of the inhaled anesthetics and sedative effects of halothane were reduced to the same extent as in global knockout lines. These data indicate that TASK channels in cholinergic neurons are a molecular substrate for select actions of inhaled anesthetics; for immobilization, which is spinally mediated, these data implicate motoneurons as the likely neuronal substrate. PMID:20519544

  16. Motoneuronal TASK channels contribute to immobilizing effects of inhalational general anesthetics.

    PubMed

    Lazarenko, Roman M; Willcox, Sarah C; Shu, Shaofang; Berg, Allison P; Jevtovic-Todorovic, Vesna; Talley, Edmund M; Chen, Xiangdong; Bayliss, Douglas A

    2010-06-02

    General anesthetics cause sedation, hypnosis, and immobilization via CNS mechanisms that remain incompletely understood; contributions of particular anesthetic targets in specific neural pathways remain largely unexplored. Among potential molecular targets for mediating anesthetic actions, members of the TASK subgroup [TASK-1 (K2P3.1) and TASK-3 (K2P9.1)] of background K(+) channels are appealing candidates since they are expressed in CNS sites relevant to anesthetic actions and activated by clinically relevant concentrations of inhaled anesthetics. Here, we used global and conditional TASK channel single and double subunit knock-out mice to demonstrate definitively that TASK channels account for motoneuronal, anesthetic-activated K(+) currents and to test their contributions to sedative, hypnotic, and immobilizing anesthetic actions. In motoneurons from all knock-out mice lines, TASK-like currents were reduced and cells were less sensitive to hyperpolarizing effects of halothane and isoflurane. In an immobilization assay, higher concentrations of both halothane and isoflurane were required to render TASK knock-out animals unresponsive to a tail pinch; in assays of sedation (loss of movement) and hypnosis (loss-of-righting reflex), TASK knock-out mice showed a modest decrease in sensitivity, and only for halothane. In conditional knock-out mice, with TASK channel deletion restricted to cholinergic neurons, immobilizing actions of the inhaled anesthetics and sedative effects of halothane were reduced to the same extent as in global knock-out lines. These data indicate that TASK channels in cholinergic neurons are molecular substrates for select actions of inhaled anesthetics; for immobilization, which is spinally mediated, these data implicate motoneurons as the likely neuronal substrates.

  17. Effects of biofeedback on trunk sway during dual tasking in the healthy young and elderly.

    PubMed

    Verhoeff, Lonneke L; Horlings, Corinne G C; Janssen, Lindy J F; Bridenbaugh, Stephanie A; Allum, John H J

    2009-07-01

    We examined the effect of biofeedback of trunk sway on balance control while walking and performing a simultaneous cognitive or motor task. Thirteen healthy elderly (mean age (+/-S.E.M.) 70.8+/-2.0 years) and 16 healthy young (mean age 21.5+/-0.7 years) subjects performed three gait tasks while wearing body-worn gyroscopes, mounted at L1-3, to measure trunk sway. The gait tasks were walking normally, walking and counting backwards in 7's, and walking while carrying a tray with cups of water. Differences in trunk sway were examined when subjects performed the gait tasks with or without a head mounted actuator system which provided subjects with vibro-tactile, auditory and visual biofeedback of trunk sway. In the young, trunk pitch (fore-aft) angles, and trunk roll (sideways) and pitch angular velocities were significantly reduced using biofeedback across all three gait tasks. In the elderly, the same angle and angular velocities were also significantly reduced while walking normally. During walking while carrying a tray, only trunk sway velocities were significantly reduced, whereas no improvements were seen for walking while counting backwards. Counting backwards ability significantly improved with feedback. Young participants were able to perform a dual task during gait and employ biofeedback to reduce trunk sway. Elderly participants were not able to reduce sway using biofeedback during the cognitive task but were able to reduce sway velocities with biofeedback during the motor task.

  18. The Task-Relevant Attribute Representation Can Mediate the Simon Effect

    PubMed Central

    Chen, Antao

    2014-01-01

    Researchers have previously suggested a working memory (WM) account of spatial codes, and based on this suggestion, the present study carries out three experiments to investigate how the task-relevant attribute representation (verbal or visual) in the typical Simon task affects the Simon effect. Experiment 1 compared the Simon effect between the between- and within-category color conditions, which required subjects to discriminate between red and blue stimuli (presumed to be represented by verbal WM codes because it was easy and fast to name the colors verbally) and to discriminate between two similar green stimuli (presumed to be represented by visual WM codes because it was hard and time-consuming to name the colors verbally), respectively. The results revealed a reliable Simon effect that only occurs in the between-category condition. Experiment 2 assessed the Simon effect by requiring subjects to discriminate between two different isosceles trapezoids (within-category shapes) and to discriminate isosceles trapezoid from rectangle (between-category shapes), and the results replicated and expanded the findings of Experiment 1. In Experiment 3, subjects were required to perform both tasks from Experiment 1. Wherein, in Experiment 3A, the between-category task preceded the within-category task; in Experiment 3B, the task order was opposite. The results showed the reliable Simon effect when subjects represented the task-relevant stimulus attributes by verbal WM encoding. In addition, the response times (RTs) distribution analysis for both the between- and within-category conditions of Experiments 3A and 3B showed decreased Simon effect with the RTs lengthened. Altogether, although the present results are consistent with the temporal coding account, we put forth that the Simon effect also depends on the verbal WM representation of task-relevant stimulus attribute. PMID:24618692

  19. Effect of task-oriented training and high-variability practice on gross motor performance and activities of daily living in children with spastic diplegia

    PubMed Central

    Kwon, Hae-Yeon; Ahn, So-Yoon

    2016-01-01

    [Purpose] This study investigates how a task-oriented training and high-variability practice program can affect the gross motor performance and activities of daily living for children with spastic diplegia and provides an effective and reliable clinical database for future improvement of motor performances skills. [Subjects and Methods] This study randomly assigned seven children with spastic diplegia to each intervention group including that of a control group, task-oriented training group, and a high-variability practice group. The control group only received neurodevelopmental treatment for 40 minutes, while the other two intervention groups additionally implemented a task-oriented training and high-variability practice program for 8 weeks (twice a week, 60 min per session). To compare intra and inter-relationships of the three intervention groups, this study measured gross motor performance measure (GMPM) and functional independence measure for children (WeeFIM) before and after 8 weeks of training. [Results] There were statistically significant differences in the amount of change before and after the training among the three intervention groups for the gross motor performance measure and functional independence measure. [Conclusion] Applying high-variability practice in a task-oriented training course may be considered an efficient intervention method to improve motor performance skills that can tune to movement necessary for daily livelihood through motor experience and learning of new skills as well as change of tasks learned in a complex environment or similar situations to high-variability practice. PMID:27821947

  20. Some Differential Effects of Two Training Group Styles.

    ERIC Educational Resources Information Center

    Boller, Jon D.

    Concurrent with the increasing interest in the training group (T-Group) as a source of growth and personal awareness for its participants, is a need to examine the effects of the T-group on certain personality types. This paper presents a rationale for examining the effects of the T-group on introverts and extroverts. Two T-group styles were…