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Sample records for effects task group

  1. Project Echo Task Group

    NASA Technical Reports Server (NTRS)

    1964-01-01

    'A technician assigned to the Project Echo Task Group separates the two hemispheres of the Echo 1 container for inspection. The charge that freed the balloon was placed inside of a ring encircling the canister at its equator.' Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, NASA SP-4308, p. 181.

  2. 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)

  3. 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.

  4. Effects of Gender and Communication Content on Leadership Emergence in Small Task-Oriented Groups.

    ERIC Educational Resources Information Center

    Hawkins, Katherine W.

    A study examined the role played by gender and communication content in the leadership emergence process in small, task-oriented groups. Six hours of transcribed group interaction from a sample of the group deliberations of 6 mixed-sex groups of college students (n=27) engaged in a 4-month-long decision-making project served as the database for…

  5. 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.

  6. 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

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

    PubMed Central

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

    2016-01-01

    [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. PMID:27390437

  8. 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

  9. 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

  10. 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

  11. 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)

  12. 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…

  13. Effects of Communication Apprehension on Perceptions of Leadership and Intragroup Attraction in Small Task-Oriented Groups.

    ERIC Educational Resources Information Center

    Hawkins, Katherine; Stewart, Robert A.

    1991-01-01

    Examines the impact of communication apprehension (CA) on perceptions of leadership and intragroup attraction in small task-oriented groups, using 68 undergraduates working on a class project. Finds high CA students were rated by themselves (and by others) to be lower in emerged leadership and social and task attraction than those with lower CA.…

  14. Interdependence and Group Effectiveness.

    ERIC Educational Resources Information Center

    Wageman, Ruth

    1995-01-01

    Investigated the differential effects of task design and reward system design on group functioning in a large U.S. corporation; the effectiveness of "hybrid" groups (having tasks and rewards with both individual and group elements); and how individuals' autonomy preferences moderate their responses to interdependence. Groups performed best when…

  15. The effects of proportional representation and gender orientation of the task on emergent leadership behavior in mixed-gender work groups.

    PubMed

    Karakowsky, L; Siegel, J P

    1999-08-01

    Much of the research that has examined the behavioral consequences of membership in mixed-gender work groups suggests that men are more participative and influential in task-related behavior. Drawing from elements of sociological, structural, and psychological perspectives, this study examined the effects of group gender composition and gender orientation of the group's task on patterns of emergent leadership behavior. Participants were assigned to male-dominated, female-dominated, or balanced-gender groups for the purpose of discussing and generating solutions for two business-related cases--each case emphasized either male-oriented or female-oriented expertise. The findings suggest that the proportional representation of men and women in a work group, along with the gender orientation of the group's task, can significantly influence the level of leadership behavior exhibited in group activity. PMID:10504894

  16. 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…

  17. The Decision-Making Process of a Small Task Group.

    ERIC Educational Resources Information Center

    Roderick, Joan C.

    1985-01-01

    This article focuses on the following areas of group process: the nature of the task group, the steps taken to reach a decision, and the ways in which a leader can effectively manage the inevitable conflict that emerges within groups as the problem-solving process progresses. (CT)

  18. ASME Task Group report on primary stress

    SciTech Connect

    Pastor, T.P.; Hechmer, J.

    1997-02-01

    This paper considers the subject of primary stress as applied in pressure vessel design carried out in accordance with the ASME Boiler and Pressure Vessel Code (1992). The paper is the result of discussions held by members of the Task Group on Primary Stress. Specific subjects discussed include methods for calculating primary stresses, the ASME limits on primary stresses and their meaning, use of the Code stress classification table in pressure vessel design, and commentary on the use of state-of-the-art analysis techniques to design pressure vessels and satisfy Code primary stress limits. A modified definition for primary stress is given, and examples for evaluating primary stresses for different geometries is provided.

  19. 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…

  20. 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,…

  1. What Is the Relationship between Socioemotional Behavior and Status in Task Groups?

    ERIC Educational Resources Information Center

    Ridgeway, Cecilia; Johnson, Cathryn

    1990-01-01

    Analyzes the way task proceedings engender emotional reactions, the conditions under which these are expressed in positive and negative socioemotional behavior, and the effect of such behavior on the status hierarchy in informal task groups. Suggests that the expression of socioemotional behavior in task groups is deeply intertwined with the…

  2. Assessing L2 Task Performance: Understanding Effects of Task Design

    ERIC Educational Resources Information Center

    Tavakoli, Parvaneh

    2009-01-01

    The overarching aim of the research reported here was to investigate the effects of task structure and storyline complexity of oral narrative tasks on second language task performance. Participants were 60 Iranian language learners of English who performed six narrative tasks of varying degree of structure and storyline complexity in an assessment…

  3. 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.

  4. 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.

  5. Sex Role and Interpersonal Behavior in Task-Oriented Groups

    ERIC Educational Resources Information Center

    Meeker, B. F.; Weitzel-O'Neill, P. A.

    1977-01-01

    The sociological theory that men are instrument or task specialists and that women are expressive or social specialists has been weakened by research on small groups, families and personality. This paper suggests that sex differences in task-oriented situations may be explained by status processes, men having higher status than women. (Author/JM)

  6. Effects of noise and task loading on a communication task loading on a communication task

    NASA Astrophysics Data System (ADS)

    Orrell, Dean H., II

    Previous research had shown the effect of noise on a single communication task. This research has been criticized as not being representative of a real world situation since subjects allocated all of their attention to only one task. In the present study, the effect of adding a loading task to a standard noise-communication paradigm was investigated. Subjects performed both a communication task (Modified Rhyme Test; House et al. 1965) and a short term memory task (Sternberg, 1969) in simulated levels of aircraft noise (95, 105 and 115 dB overall sound pressure level (OASPL)). Task loading was varied with Sternberg's task by requiring subjects to memorize one, four, or six alphanumeric characters. Simulated aircraft noise was varied between levels of 95, 105 and 115 dB OASPL using a pink noise source. Results show that the addition of Sternberg's task and little effect on the intelligibility of the communication task while response time for the communication task increased.

  7. 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…

  8. 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.

  9. Task frequency influences stimulus-driven effects on task selection during voluntary task switching.

    PubMed

    Arrington, Catherine M; Reiman, Kaitlin M

    2015-08-01

    Task selection during voluntary task switching involves both top-down (goal-directed) and bottom-up (stimulus-driven) mechanisms. The factors that shift the balance between these two mechanisms are not well characterized. In the present research, we studied the role that task frequency plays in determining the extent of stimulus-driven task selection. In two experiments, we used the basic paradigm adapted from Arrington (Memory & Cognition, 38, 991-997, 2008), in which the effect of stimulus availability serves as a marker of stimulus-driven task selection. A number and letter appeared on each trial with varying stimulus onset asynchronies, and participants performed either a consonant/vowel or an even/odd judgment. In Experiment 1, participants were instructed as to the relative frequency with which each task was to be performed (i.e., 50/50, 60/40, or 75/25) and were further instructed to make their transitions between tasks unpredictable. In Experiment 2, participants were given no instructions about how to select tasks, resulting in naturally occurring variation in task frequency. With both instructed (Exp. 1) and naturally occurring (Exp. 2) relative task frequencies, the less frequently performed task showed a greater effect of stimulus availability on task selection, suggestive of a larger influence of stimulus-driven mechanisms during task performance for the less frequent task. When goal-directed mechanisms of task choice are engaged less frequently, the relative influence of the stimulus environment increases. PMID:26106057

  10. Perceptual grouping by similarity of surface roughness in haptics: the influence of task difficulty.

    PubMed

    Van Aarsen, V; Overvliet, K E

    2016-08-01

    We investigated grouping by similarity of surface roughness in the context of task difficulty. We hypothesized that grouping yields a larger benefit at higher levels of task complexity, because efficient processing is more helpful when more cognitive resources are needed to execute a task. Participants searched for a patch of a different roughness as compared to the distractors in two strips of similar or dissimilar roughness values. We reasoned that if the distractors could be grouped based on similar roughness values, exploration time would be shorter and fewer errors would occur. To manipulate task complexity, we varied task difficulty (high target saliency equalling low task difficulty), and we varied the fingers used to explore the display (two fingers of one hand being more cognitive demanding than two fingers of opposite hands). We found much better performance in the easy condition as compared to the difficult condition (in both error rates and mean search slopes). Moreover, we found a larger effect for the similarity manipulation in the difficult condition as compared to the easy condition. Within the difficult condition, we found a larger effect for the one-hand condition as compared to the two-hand condition. These results show that haptic search is accelerated by the use of grouping by similarity of surface roughness, especially when the task is relatively complex. We conclude that the effect of perceptual grouping is more prominent when more cognitive resources are needed to perform a task. PMID:27010724

  11. Choice Consistency of Interpersonal Relations: Diversified Task-Oriented Groups.

    ERIC Educational Resources Information Center

    Duncan, W. Jack; Beeland, James L.

    1980-01-01

    Investigates seven task-oriented groups which examine consistency of social choice across a range of behavioral criteria (friendship, leadership, followship, and evaluation criteria of social interaction). Results suggest that some criteria of interpersonal relations are interdependent: acceptance and rejection choices are not opposite ends of…

  12. How within-group behavioural variation and task efficiency enhance fitness in a social group

    PubMed Central

    Pruitt, Jonathan N.; Riechert, Susan E.

    2011-01-01

    How task specialization, individual task performance and within-group behavioural variation affects fitness is a longstanding and unresolved problem in our understanding of animal societies. In the temperate social spider, Anelosimus studiosus, colony members exhibit a behavioural polymorphism; females either exhibit an aggressive ‘asocial’ or docile ‘social’ phenotype. We assessed individual prey-capture success for both phenotypes, and the role of phenotypic composition on group-level prey-capture success for three prey size classes. We then estimated the effect of group phenotypic composition on fitness in a common garden, as inferred from individual egg-case masses. On average, asocial females were more successful than social females at capturing large prey, and colony-level prey-capture success was positively associated with the frequency of the asocial phenotype. Asocial colony members were also more likely to engage in prey-capture behaviour in group-foraging situations. Interestingly, our fitness estimates indicate females of both phenotypes experience increased fitness when occupying colonies containing unlike individuals. These results imply a reciprocal fitness benefit of within-colony behavioural variation, and perhaps division of labour in a spider society. PMID:20943687

  13. 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…

  14. Task group to develop list of environmental standards

    NASA Astrophysics Data System (ADS)

    A new task group designed to develop a list of existing and potential standards that are applicable to environmental contamination problems in soil, rock, and groundwater has been established by the American Society for Testing a n d Materials (ASTM) Subcommittee on Geotechnics of Waste Management. The list currently includes over 60 existing and draft ASTM standards from ASTM committees in the areas of site characterization, construction evaluation, and geosynthetics.

  15. The numerical distance effect is task dependent.

    PubMed

    Goldfarb, Liat; Henik, Avishai; Rubinsten, Orly; Bloch-David, Yafit; Gertner, Limor

    2011-11-01

    Number comparison tasks produce a distance effect e.g., Moyer & Landauer (Nature 215: 1519-1520, 1967). It has been suggested that this effect supports the existence of semantic mental representations of numbers. In a matching task, a distance effect also appears, which suggests that the effect has an automatic semantic component. Recently, Cohen (Psychonomic Bulletin & Review 16: 332-336, 2009) suggested that in both automatic and intentional tasks, the distance effect might reflect not a semantic number representation, but a physical similarity between digits. The present article (1) compares the distance effect in the automatic matching task with that in the intentional number comparison task and suggests that, in the latter, the distance effect does include an additional semantic component; and (2) indicates that the distance effect in the standard automatic matching task is questionable and that its appearance in previous matching tasks was based on the specific analysis and design that were applied. PMID:21698497

  16. 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.

  17. Effect of heat and chemical protective clothing on the ability of a group of female soldiers to sustain performance of military cognitive tasks. Final report

    SciTech Connect

    Fine, B.J.

    1987-12-01

    The author previously found that chemical protective clothing seriously degraded the performance of sedentary male soldiers doing sustained mental work in the heat. Here in an identical study, the authors examine the performance of female soldiers in protective clothing. To the author's knowledge, this is the only controlled study of its kind with women. Eighteen female soldiers trained for two weeks on cognitive tasks resembling those performed by fire direction center, forward observer, and communications personnel. Then, they performed the tasks for seven-hour periods on four successive days in hot (91 F., 61% RH) and normal (55 F., 35% RH) or (70 F., 35% RH) with and without chemical protective clothing.

  18. Interpersonal Attractiveness and Distribution of Task Relevant Information as Contributors to an Influence Base in Task Oriented Groups.

    ERIC Educational Resources Information Center

    Reinheimer, Robert Edward

    This study focused on the role played by two factors--interpersonal attractiveness of group members and pattern of distribution of task-relevant information--in forming an influence base in task-oriented discussion groups. For purposes of the study, members of discussion groups who were confederates in the study were assigned attitudinal…

  19. 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…

  20. 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.

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

    NASA Technical Reports Server (NTRS)

    Parasuraman, R.; Mouloua, M.; Molloy, R.

    1996-01-01

    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.

  2. Task Group 142 report: quality assurance of medical accelerators.

    PubMed

    Klein, Eric E; Hanley, Joseph; Bayouth, John; Yin, Fang-Fang; Simon, William; Dresser, Sean; Serago, Christopher; Aguirre, Francisco; Ma, Lijun; Arjomandy, Bijan; Liu, Chihray; Sandin, Carlos; Holmes, Todd

    2009-09-01

    The task group (TG) for quality assurance of medical accelerators was constituted by the American Association of Physicists in Medicine's Science Council under the direction of the Radiation Therapy Committee and the Quality Assurance and Outcome Improvement Subcommittee. The task group (TG-142) had two main charges. First to update, as needed, recommendations of Table II of the AAPM TG-40 report on quality assurance and second, to add recommendations for asymmetric jaws, multileaf collimation (MLC), and dynamic/virtual wedges. The TG accomplished the update to TG-40, specifying new test and tolerances, and has added recommendations for not only the new ancillary delivery technologies but also for imaging devices that are part of the linear accelerator. The imaging devices include x-ray imaging, photon portal imaging, and cone-beam CT. The TG report was designed to account for the types of treatments delivered with the particular machine. For example, machines that are used for radiosurgery treatments or intensity-modulated radiotherapy (IMRT) require different tests and/or tolerances. There are specific recommendations for MLC quality assurance for machines performing IMRT. The report also gives recommendations as to action levels for the physicists to implement particular actions, whether they are inspection, scheduled action, or immediate and corrective action. The report is geared to be flexible for the physicist to customize the QA program depending on clinical utility. There are specific tables according to daily, monthly, and annual reviews, along with unique tables for wedge systems, MLC, and imaging checks. The report also gives specific recommendations regarding setup of a QA program by the physicist in regards to building a QA team, establishing procedures, training of personnel, documentation, and end-to-end system checks. The tabulated items of this report have been considerably expanded as compared with the original TG-40 report and the recommended

  3. Effect of music tempo on task performance.

    PubMed

    Mayfield, C; Moss, S

    1989-12-01

    Two studies were conducted to evaluate the effect of music tempo on task performance. In Study 1, 44 undergraduate business students were asked to be "workers" in a stock market project by collecting closing stock prices and calculating the percentage of change in the price from week to week. Subjects were randomly divided into groups such that they either listened to fast-paced music while they worked, to slow-paced music, or to no music. Analyses of variance and covariance were conducted on both the quantity and quality of the subjects' work, using music listening habits as a covariate. There were no differences in either the quantity or quality of the work produced by the groups. There were some methodological concerns regarding Study 1, so a second study was conducted. The 70 undergraduate business students in Study 2 completed the same task under the same music conditions as in Study 1. Analyses of variance indicated women performed significantly better than men, performance was significantly higher in the rock condition than in the heartbeat condition, and subjects in the rock condition had a significantly higher perceived level of distraction by the music. PMID:2623126

  4. Canadian Union Catalogue Task Group Final Report to the National Librarian of Canada.

    ERIC Educational Resources Information Center

    National Library of Canada, Ottawa (Ontario).

    The Task Group advocates the development, with the guidance and support of the National Library of Canada, of a Canadian Library Network with the objectives of equalizing opportunity for access to information and making use of total Canadian library resources more cost-effective. This network would be composed of three interrelated components--a…

  5. Secondary-task effects on sequence learning.

    PubMed

    Heuer, H; Schmidtke, V

    1996-01-01

    With a repeated sequence of stimuli, performance in a serial reaction-time task improves more than with a random sequence. The difference has been taken as a measure of implicit sequence learning. Implicit sequence learning is impaired when a secondary task is added to the serial RT task. In the first experiment, secondary-task effects on different types of sequences were studied to test the hypothesis that the learning of unique sequences (where each sequence element has a unique relation to the following one) is not impaired by the secondary task, while the learning of ambiguous sequences is. The sequences were random up to a certain order of sequential dependencies, where they became deterministic. Contrary to the hypothesis, secondary-task effects on the learning of unique sequences were as strong or stronger than such effects on the learning of ambiguous sequences. In the second experiment a hybrid sequence (with unique as well as ambiguous transitions) was used with different secondary tasks. A visuo-spatial and a verbal memory task did not interfere with the learning of the sequence, but interference was observed with an auditory go/no-go task in which high- and low-pitched tones were presented after each manual response and a foot pedal had to be pressed in response to high-pitched tones. Thus, interference seems to be specific to certain secondary tasks and may be related to memory processes (but most likely not to visuo-spatial and verbal memory) or to the organizations of sequences, consistent with previous suggestions. PMID:8810586

  6. Working memory effects in speeded RSVP tasks.

    PubMed

    Gil-Gómez de Liaño, Beatriz; Potter, Mary C; Rodríguez, Carmen

    2014-01-01

    The present paper examines the effects of memory contents and memory load in rapid serial visual presentation (RSVP) speeded tasks, trying to explain previous inconsistent results. We used a one target (Experiment 1) and a two-target (Experiment 2) RSVP task with a concurrent memory load of one or four items, in a dual-task paradigm. A relation between material in working memory and the target in the RSVP impaired the identification of the target. In Experiments 3 and 4, the single task was to determine whether any information in memory matched the target in the RSVP, while varying the memory load. A match was detected faster than a non-match, although only when there was some distance between targets in the RSVP (Experiment 4). The results suggest that memory contents automatically capture attention, slowing processing when the memory contents are irrelevant to the task, and speeding processing when they are relevant. PMID:23397260

  7. Effects of Noise on Small Group Interaction.

    ERIC Educational Resources Information Center

    Whitehead, Jack L.

    This study reports an analysis of the effects of moderate levels of noise on task performance of an interacting group. Groups of students first interacted in information-sharing discussions under varying conditions of noise and then responded to an objective test over the shared information and to a series of semantic differential scales designed…

  8. 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…

  9. 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. PMID:25218656

  10. Cortisol Responses to a Group Public Speaking Task for Adolescents: Variations by Age, Gender, and Race

    PubMed Central

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

    2014-01-01

    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 5 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. PMID:25218656

  11. Student Perceptions of Social Task Development in Online Group Project Work

    ERIC Educational Resources Information Center

    Morgan, Kari; Cameron, Bruce A.; Williams, Karen C.

    2009-01-01

    This article explores student perceptions of social task development in an online group project and poses recommendations for implementation of group projects. Qualitative methods were used to analyze student perceptions of social task development in online group project. Respect, "being nice," follow the rules/follow the leader, communication,…

  12. 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

  13. Using a Random Dependent Group Contingency to Increase On-Task Behaviors of High School Students with High Incidence Disabilities

    ERIC Educational Resources Information Center

    Williamson, Brenda D.; Campbell-Whatley, Gloria D.; Lo, Ya-yu

    2009-01-01

    Group contingencies have the advantages of encouraging individual students to collectively feel responsible for appropriate and inappropriate classroom behaviors and have shown effectiveness in improving students' behavior. The purpose of this study was to investigate the effects of a random dependent group contingency on the on-task behaviors of…

  14. 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.

  15. 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.…

  16. 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…

  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. Communication on a problem solving task in cooperative learning groups

    NASA Astrophysics Data System (ADS)

    Sadler, Jo; Fawns, Rod

    1992-12-01

    There is some evidence from this study that reflectivity within cooperative learning groups develops over time. Preliminary observations suggest that Slavin's third and fourth levels of skills, those of reflection and reasoning and reconception and reformulation and Kempa and Ayob's higher levels of explanation and insight appear more advanced in groups strategically managed by teachers for such outcomes. Later analyses will permit more detailed accounts of the relationships between the teacher's management strategies, and reflection within groups of different gender composition.

  19. The effects of task demands on bimanual skill acquisition

    PubMed Central

    Bastian, Amy J.

    2013-01-01

    Bimanual coordination is essential for everyday activities. It is thought that different degrees of demands may affect learning of new bimanual patterns. One demand is at the level of performance and involves breaking the tendency to produce mirror-symmetric movements. A second is at a perceptual level and involves controlling each hand to separate (i.e., split) goals. A third demand involves switching between different task contexts (e.g., a different uni- or bimanual task), instead of continuously practicing one task repeatedly. Here, we studied the effect of these task demands on motor planning (reaction time) and execution (error) while subjects learned a novel bimanual isometric pinch force task. In Experiment 1, subjects continuously practiced in one of the two extremes of the following bimanual conditions: (1) symmetric force demands and a perceptually unified target for each hand or (2) asymmetric force demands and perceptually split targets. Subjects performing in the asymmetric condition showed some interference between hands, but all subjects, regardless of group, could learn the isometric pinch force task similarly. In Experiment 2, subjects practiced these and two other conditions, but in a paradigm where practice was briefly interrupted by the performance of either a unimanual or a different bimanual condition. Reaction times were longer and errors were larger well after the interruption when the main movement to be learned required asymmetric forces. There was no effect when the main movement required symmetric forces. These findings demonstrate two main points. First, people can learn bimanual tasks with very different demands on the same timescale if they are not interrupted. Second, interruption during learning can negatively impact both planning and execution and this depends on the demands of the bimanual task to be learned. This information will be important for training patient populations, who may be more susceptible to increased task demands

  20. The Role of Communication in Group Decision-Making Efficacy: A Task-Contingency Perspective.

    ERIC Educational Resources Information Center

    Hirokawa, Randy Y.

    1990-01-01

    Argues importance of communication for group decision-making performance and its impact on such performance are function of three task characteristics: structure, information requirement, and evaluation demand. Identifies task circumstances in which group communication can be expected to play role in determining decision-making performance, as…

  1. Task Interpretation and Task Effectiveness: A Vygotskian Analysis of a French L2 Classroom Task.

    ERIC Educational Resources Information Center

    Myers, Lindsy L.

    2000-01-01

    This paper focuses on second language (L2) learning through task-based interaction as well as the compatibility of the theories of task-based learning and Vygotsky's sociocultural theory. Language tasks encourage L2 learning by using language as a tool to accomplish a goal. This study analyzes the interaction of first-semester French students…

  2. Optimal Group Size for Software Change Tasks: A Social Information Foraging Perspective.

    PubMed

    Bhowmik, Tanmay; Niu, Nan; Wang, Wentao; Cheng, Jing-Ru C; Li, Ling; Cao, Xiongfei

    2016-08-01

    Group size is a key factor in collaborative software development and many other cybernetic applications where task assignments are important. While methods exist to estimate its value for proprietary projects, little is known about how group size affects distributed and decentralized cybernetic applications and in particular open source software (OSS) development. This paper presents a novel approach in which we frame developers' collective resolution of OSS change tasks as a social information foraging problem. This new perspective enables us to predict the optimal group size and quantify group size's effect on individual performance. We test the theory with data mined from two projects: 1) Firefox and 2) Mylyn. This paper not only uncovers the mismatch of optimal and actual group sizes, but also reveals the association of optimality with improved productivity. In addition, the social-level productivity gain is observed as project evolves. We show this paper's impact by extending the frontiers of knowledge in two areas: 1) social coding and 2) recommendation systems. PMID:25910274

  3. Report of the President's Blue Ribbon Task Group on Nuclear Weapons Program Management

    SciTech Connect

    Not Available

    1985-07-01

    The President established the Blue Ribbon Task Group on Nuclear Weapons Program Management at the direction of the Congress to address fiscal accountability and discipline in the nation's nuclear weapons program. The Task Group was asked to ''examine the procedures used by DOD and DOE in establishing requirements for, and providing resources for, the research, development, testing, production, surveillance, and retirement of nuclear weapons,'' and to recommend any needed change in coordination, budgeting, or management procedures. The Task Group was also asked to address ''whether DOD should assume the responsibility for funding current DOE weapon activities and material production programs.'' The Task Group found that the present relationship between DOD and DOE for managing the nuclear weapons program is sound. Accordingly, the Task Group sought a process for improving the integrated determination of nuclear weapon requirements and the management of nuclear weapon production.

  4. Presenting Chained and Discrete Tasks as Non-Targeted Information when Teaching Discrete Academic Skills through Small Group Instruction

    ERIC Educational Resources Information Center

    Falkenstine, Karen Jones; Collins, Belva C.; Schuster, John W.; Kleinert, Harold

    2009-01-01

    Special education teachers often search for effective strategies to teach a variety of skills to students with moderate to severe disabilities through small group instruction. The investigators examined the acquisition of academic skills as well as chained and discrete tasks presented as nontargeted information by a small group of students with…

  5. 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.

  6. 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…

  7. 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;…

  8. Progesterone and Mental Rotation Task: Is There Any Effect?

    PubMed Central

    Noreika, Donatas; Griškova-Bulanova, Inga; Alaburda, Aidas; Baranauskas, Mindaugas; Grikšienė, Ramunė

    2014-01-01

    Mental rotation task (MRT) incorporates elements of spatial abilities, important in many professions, with people of both genders involved. Importantly, these are the areas where spatial tasks might be performed for long time periods; thus adverse effects of mental fatigue are highly unwanted. Substantial variation of MRT performance in relation to estrogen levels has been observed in many studies, whereas the role of progesterone remains elusive. Here we aimed to elucidate the effect of progesterone level on the long-duration (1.5 hours) performance of MRT. We included three groups of subjects: a group of males as a control, a group of females in their follicular phase (low progesterone) and a group of females in their luteal phase (high progesterone), MRT accuracy and response time, subjective fatigue ratings and cardiovascular measures together with 17β-estradiol and progesterone concentrations were analyzed. We found that subjective ratings of fatigue increased, performance accuracy increased, and mean response times decreased during the task in all groups. Females in luteal phase were significantly slower not only than men, but also than females in their follicular phase. An increase in subjective fatigue ratings was positively related to progesterone level—at higher progesterone levels, females felt more tired. PMID:24818150

  9. Progesterone and mental rotation task: is there any effect?

    PubMed

    Noreika, Donatas; Griškova-Bulanova, Inga; Alaburda, Aidas; Baranauskas, Mindaugas; Grikšienė, Ramunė

    2014-01-01

    Mental rotation task (MRT) incorporates elements of spatial abilities, important in many professions, with people of both genders involved. Importantly, these are the areas where spatial tasks might be performed for long time periods; thus adverse effects of mental fatigue are highly unwanted. Substantial variation of MRT performance in relation to estrogen levels has been observed in many studies, whereas the role of progesterone remains elusive. Here we aimed to elucidate the effect of progesterone level on the long-duration (1.5 hours) performance of MRT. We included three groups of subjects: a group of males as a control, a group of females in their follicular phase (low progesterone) and a group of females in their luteal phase (high progesterone), MRT accuracy and response time, subjective fatigue ratings and cardiovascular measures together with 17 β -estradiol and progesterone concentrations were analyzed. We found that subjective ratings of fatigue increased, performance accuracy increased, and mean response times decreased during the task in all groups. Females in luteal phase were significantly slower not only than men, but also than females in their follicular phase. An increase in subjective fatigue ratings was positively related to progesterone level-at higher progesterone levels, females felt more tired. PMID:24818150

  10. Cardiovascular reactivity and adaptation to recurrent psychological stress: effects of prior task exposure.

    PubMed

    Kelsey, R M; Blascovich, J; Tomaka, J; Leitten, C L; Schneider, T R; Wiens, S

    1999-11-01

    The effects of prior task exposure on cardiovascular reactivity to stress were examined in two experiments by randomly assigning participants to repeated exposure groups that performed mental arithmetic pretest and test tasks versus delayed exposure groups that performed only the test task after prolonged rest. Impedance cardiographic and blood pressure measures were recorded continuously from 60 undergraduate men in Experiment 1 and 112 undergraduate men and women in Experiment 2. Task repetition attenuated cardiovascular reactivity and improved task performance in repeated exposure groups (p < .001), suggesting an integrated process of behavioral adaptation. During the test task, delayed exposure groups showed greater cardiac reactivity (p < .01), but not vascular reactivity, than repeated exposure groups. Thus, cardiac reactivity varied as a specific function of prior task exposure, whereas vascular reactivity varied as a general function of time. PMID:10554594

  11. The Effects of Input-Based Tasks on the Development of Learners' Pragmatic Proficiency

    ERIC Educational Resources Information Center

    Takimoto, Masahiro

    2009-01-01

    The present study evaluates the relative effectiveness of three types of input-based approaches for teaching English polite request forms to sixty Japanese learners of English: (a) structured input tasks with explicit information; (b) problem-solving tasks; and (c) structured input tasks without explicit information. Treatment group performance…

  12. 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. PMID:27241617

  13. Phonological similarity effect in complex span task.

    PubMed

    Camos, Valérie; Mora, Gérôme; Barrouillet, Pierre

    2013-01-01

    The aim of our study was to test the hypothesis that two systems are involved in verbal working memory; one is specifically dedicated to the maintenance of phonological representations through verbal rehearsal while the other would maintain multimodal representations through attentional refreshing. This theoretical framework predicts that phonologically related phenomena such as the phonological similarity effect (PSE) should occur when the domain-specific system is involved in maintenance, but should disappear when concurrent articulation hinders its use. Impeding maintenance in the domain-general system by a concurrent attentional demand should impair recall performance without affecting PSE. In three experiments, we manipulated the concurrent articulation and the attentional demand induced by the processing component of complex span tasks in which participants had to maintain lists of either similar or dissimilar words. Confirming our predictions, PSE affected recall performance in complex span tasks. Although both the attentional demand and the articulatory requirement of the concurrent task impaired recall, only the induction of an articulatory suppression during maintenance made the PSE disappear. These results suggest a duality in the systems devoted to verbal maintenance in the short term, constraining models of working memory. PMID:23419012

  14. 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…

  15. 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. PMID:21490234

  16. The Quantity and Quality of Language Practice in Typical Interactive Pair/Group Tasks

    ERIC Educational Resources Information Center

    Collins, Laura; White, Joanna

    2014-01-01

    This article reports on a study examining the language practice opportunities that occurred during a range of paired and small group interactive tasks in an intensive English as a Second Language (ESL) class of francophone Grade 6 students. The analysis focussed on the opportunities the tasks provided for the use of two complex and challenging…

  17. 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)

  18. Small, Task-Oriented Groups: Conflict, Conflict Management, Satisfaction, and Decision Quality.

    ERIC Educational Resources Information Center

    Wall, Victor D., Jr.; And Others

    1987-01-01

    Examined relationship among amount of conflict experienced, the style of its management, individual satisfaction, and decision quality of small, task-oriented groups using 129 college student subjects in 24 groups. Data suggest a curvilinear relationship between the number of conflict episodes experienced by group members and the subsequent…

  19. 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…

  20. A Comparison of Hypnotic Induction, Task Motivation, and a "Cold Start" Control Group on Hypnotizability.

    PubMed

    Krystek, Stephen; Kumar, V K

    2016-10-01

    Groups of participants (N = 164) were randomly assigned to three conditions: Group 1 received a trance induction, Group 2 received task-motivational instructions, and Group 3-"cold start" control-was simply told, "We will begin the hypnosis procedure now." All participants received the Creative Imagination Scale suggestions and then completed the Creative Imagination Scale and Inventory Scale of Hypnotic Depth. The three conditions did not differ significantly either on the Creative Imagination Scale or in reported hypnotic depth. These results are consistent with prior studies which show that trance induction and task-motivational yield similar results, but they are inconsistent inasmuch as the trance induction and task-motivational groups did not differ from the control group. These results, however, are predictable from socio-cognitive perspectives that the context of hypnosis itself can elicit hypnotic behaviors. PMID:27586049

  1. Effects of Noise on Reading Comprehension and Task Completion Time. Final Report.

    ERIC Educational Resources Information Center

    Jewell, Larry R.; Weston, Curtis R.

    To determine the effects of noise intensities found in vocational shops and laboratories on student reading comprehension and task completion time, a study was conducted involving 94 students from 6 schools. The students were randomly assigned to either a control group or an experimental group and given the task of reading and answering questions.…

  2. Prospective memory in young and older adults: the effects of task importance and ongoing task load.

    PubMed

    Smith, Rebekah E; Hunt, R Reed

    2014-01-01

    Remembering to perform an action in the future, called prospective memory, often shows age-related differences in favor of young adults when tested in the laboratory. Recently Smith, Horn, and Bayen (2012; Aging, Neuropsychology, and Cognition, 19, 495) embedded a PM task in an ongoing color-matching task and manipulated the difficulty of the ongoing task by varying the number of colors on each trial of the task. Smith et al. found that age-related differences in PM performance (lower PM performance for older adults relative to young adults) persisted even when older adults could perform the ongoing task as well or better than the young adults. The current study investigates a possible explanation for the pattern of results reported by Smith et al. by including a manipulation of task emphasis: for half of the participants the prospective memory task was emphasize, while for the other half the ongoing color-matching task was emphasized. Older adults performed a 4-color version of the ongoing color-matching task, while young adults completed either the 4-color or a more difficult 6-color version of the ongoing task. Older adults failed to perform as well as the young adults on the prospective memory task regardless of task emphasis, even when older adults were performing as well or better than the young adults on the ongoing color-matching task. The current results indicate that the lack of an effect of ongoing task load on prospective memory task performance is not due to a perception that one or the other task is more important than the other. PMID:24628461

  3. 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

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

    PubMed

    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

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

    PubMed Central

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

    2015-01-01

    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. PMID:26759790

  6. 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…

  7. Economically Functional Considerations for an Interactional House Plan, Senior High School (Task Group Report).

    ERIC Educational Resources Information Center

    Paul, Warren I.

    A task group was charged with remodeling an existing connected old building-new building complex to make it feasible for a house-oriented senior high school educational program. Constraints to be resolved were keeping costs low, maintaining departmental proximity while encouraging interdisciplinary activities, providing for small groups, and…

  8. 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.

  9. Hypermnesia for high-imagery words: the effects of interpolated tasks.

    PubMed

    Shaw, G A; Bekerian, D A

    1991-01-01

    The purpose of this study was to determine whether hypermnesia (improved net recall over time) can be differentially affected by manipulating the nature of tasks performed during the intervals between successive recall trials. In Experiment 1, all subjects were asked to imaginally encode separate words and were tested three times for recall. The control group (no interpolated task) produced the hypermnesia effect. Both groups performing interpolated tasks showed significantly lower recall. A second experiment was conducted in order to replicate these results and to examine the effects of intertest rehearsal on hypermnesia. In Experiment 2, subjects were asked to encode pairs of words using interactive-imagery instructions. Six different interpolated task conditions were employed, varying in the degree to which subsystems of working memory were used. Groups performing imaginal interpolated tasks showed no hypermnesia, whereas those performing nonimaginal tasks did. These findings suggest that access to working memory (see Baddeley, 1986) is not necessary for hypermnesia. PMID:2017034

  10. Sensitivity of negative subsequent memory and task-negative effects to age and associative memory performance.

    PubMed

    de Chastelaine, Marianne; Mattson, Julia T; Wang, Tracy H; Donley, Brian E; Rugg, Michael D

    2015-07-01

    The present fMRI experiment employed associative recognition to investigate the relationships between age and encoding-related negative subsequent memory effects and task-negative effects. Young, middle-aged and older adults (total n=136) were scanned while they made relational judgments on visually presented word pairs. In a later memory test, the participants made associative recognition judgments on studied, rearranged (items studied on different trials) and new pairs. Several regions, mostly localized to the default mode network, demonstrated negative subsequent memory effects in an across age-group analysis. All but one of these regions also demonstrated task-negative effects, although there was no correlation between the size of the respective effects. Whereas negative subsequent memory effects demonstrated a graded attenuation with age, task-negative effects declined markedly between the young and the middle-aged group, but showed no further reduction in the older group. Negative subsequent memory effects did not correlate with memory performance within any age group. By contrast, in the older group only, task-negative effects predicted later memory performance. The findings demonstrate that negative subsequent memory and task-negative effects depend on dissociable neural mechanisms and likely reflect distinct cognitive processes. The relationship between task-negative effects and memory performance in the older group might reflect the sensitivity of these effects to variations in amount of age-related neuropathology. This article is part of a Special Issue entitled SI: Memory. PMID:25264353

  11. 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)

  12. Steam generator group project: Task 13 final report: Nondestructive examination validation

    SciTech Connect

    Bradley, E.R.; Doctor, P.G.; Ferris, R.H.; Buchanan, J.A.

    1988-08-01

    The Steam Generator Group Project (SGGP) was a multi-task effort using the retired-from-service Surry 2A pressurized water reactor steam generator as a test bed to investigate the reliability and effectiveness of in-service nondestructive eddy current (EC) inspection equipment and procedures. The information developed provided the technical basis for recommendations for improved in- service inspection and tube plugging criteria of steam generators. This report describes the results and analysis from Task 13--NDE Validation. The primary objective of Task 13 was to validate the EC inspection to detect and size tube defects. Additional objectives were to assess the nature and severity of tube degradation from all regions of the generator and to measure the remaining integrity of degraded specimens by burst testing. More than 550 specimens were removed from the generator and included in the validation studies. The bases for selecting the specimens and the methods and procedures used for specimen removal from the generator are reported. Results from metallurgical examinations of these specimens are presented and discussed. These examinations include visual inspection of all specimens to locate and identify tube degradation, metallographic examination of selected specimens to establish defect severity and burst testing of selected specimens to establish the remaining integrity of service-degraded tubes. Statistical analysis of the combined metallurgical and EC data to determine the probability of detection (POD) and sizing accuracy are reported along with a discussion of the factors which influenced the EC results. Finally, listings of the metallurgical and corresponding EC data bases are given. 12 refs., 141 figs., 24 tabs.

  13. 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

  14. Complexity Effects on the Children's Gambling Task

    ERIC Educational Resources Information Center

    Bunch, Katie M.; Andrews, Glenda; Halford, Graeme S.

    2007-01-01

    The children's gambling task (CGT [Kerr, A., & Zelazo, P. D. (2004). Development of "Hot" executive function: The children's gambling task. "Brain and Cognition," 55, 148-157]) involves integrating information about losses and gains to maximize winnings when selecting cards from two decks. Both cognitive complexity and control (CCC) theory and…

  15. 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. PMID:25551257

  16. Dual-task backward compatibility effects are episodically mediated.

    PubMed

    Giammarco, Maria; Thomson, Sandra J; Watter, Scott

    2016-02-01

    In dual-task performance, the backward compatibility effect (BCE; faster Task 1 reaction time when Task 1 and Task 2 responses are compatible) is thought to represent automatic activation of Task 2 response information in parallel with attended Task 1 performance. Work by Hommel and Eglau (Psychological Research, 66, 260-273, 2002) has suggested the BCE relies on stimulus-response learning in long-term memory. Subsequent work by Ellenbogen and Meiran (Memory and Cognition, 36, 968-978, 2008), however, proposed that the BCE is mediated by Task 2 rules held in working memory (WM) during Task 1 performance. The present study aimed to dissociate these two theoretical claims. In Experiment 1, we assessed the effects of prior single-task practice with Task 1 or Task 2 of a subsequent dual-task paradigm. Where the WM-mediated model predicts both BCE and overall reaction time improvement relative to prior task practice, an episodic learning model makes divergent predictions for BCE based on the context specificity of prior Task 2 learning. Results showed a close fit with episodic predictions and contradicted WM model predictions. Experiment 2 examined the finer grained timecourse of BCE over initial development, subsequent interference of this initial learning on BCE development with new conflicting Task 2 response mappings, and finally reestablishment of BCE in the original dual task. Data again showed close agreement with long-term learning predictions. We argue in favor of an episodic account of the BCE, and consider implications of WM and episodic mechanisms of automatic response activation on other aspects of dual-task performance. PMID:26572914

  17. Inhibition Plasticity in Older Adults: Practice and Transfer Effects Using a Multiple Task Approach

    PubMed Central

    Wilkinson, Andrea J.; Yang, Lixia

    2016-01-01

    Objective. To examine plasticity of inhibition, as indexed by practice effects of inhibition tasks and the associated transfer effects, using a multiple task approach in healthy older adults. Method. Forty-eight healthy older adults were evenly assigned to either a practice group or a no-contact control group. All participants completed pretest (2.5 hours) and posttest (2 hours) sessions, with a 2-week interval in between. During the 2-week interval, only the practice group completed six 30-minute practice sessions (three sessions per week for two consecutive weeks) of three lab-based inhibition tasks. Results. All three inhibition tasks demonstrated significant improvement across practice sessions, suggesting practice-induced plasticity. The benefit, however, only transferred to near-near tasks. The results are inconclusive with regard to the near-far and far-far transfer effects. Discussion. This study further extends literature on practice effects of inhibition in older adults by using a multiple task approach. Together with previous work, the current study suggests that older adults are able to improve inhibition performance through practice and transfer the practice gains to tasks that overlap in both target cognitive ability and task structure (i.e., near-near tasks). PMID:26885407

  18. HIV and Nurses: A Focus Group on Task Shifting in Uganda.

    PubMed

    Spies, Lori A; Gray, Jennifer; Opollo, Jackline; Mbalinda, Scovia

    2016-01-01

    The HIV prevalence rate is 7.4% in Uganda, where the HIV-related President's Emergency Plan for AIDS Relief and United Nations millennial development goals have not been met. This is partially due to a critical shortage of nurses and other health care providers. Task shifting is a World Health Organization strategy to address the shortage of human resources for health by shifting work from one cadre of health care worker to another, often less-trained, cadre. We conducted three focus groups with nurses in Uganda to better understand perceptions of their preparation for and implementation of task shifting. The focus group included nurses from diverse work settings. Data analysis revealed that nurses were proud of the work they were doing but were challenged by the lack of consistent and appropriate support. We found a need for additional policies, regulations, and consistent preparation for nurses who work in environments with task shifting. PMID:26847378

  19. Does the medium matter? The interaction of task type and technology on group performance and member reactions.

    PubMed

    Straus, S G; McGrath, J E

    1994-02-01

    The authors investigated the hypothesis that as group tasks pose greater requirements for member interdependence, communication media that transmit more social context cues will foster group performance and satisfaction. Seventy-two 3-person groups of undergraduate students worked in either computer-mediated or face-to-face meetings on 3 tasks with increasing levels of interdependence: an idea-generation task, an intellective task, and a judgment task. Results showed few differences between computer-mediated and face-to-face groups in the quality of the work completed but large differences in productivity favoring face-to-face groups. Analysis of productivity and of members' reactions supported the predicted interaction of tasks and media, with greater discrepancies between media conditions for tasks requiring higher levels of coordination. Results are discussed in terms of the implications of using computer-mediated communications systems for group work. PMID:8200874

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

    PubMed

    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

  1. 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

  2. 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…

  3. 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...

  4. 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...

  5. 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…

  6. University of North Carolina Council on Biotechnology Patent Task Group Report.

    ERIC Educational Resources Information Center

    Journal of College and University Law, 1982

    1982-01-01

    A report of a task group on biomedical patents summarizes the context in which technological innovation involving research institutions and industry takes place and the interests and concerns of various participants. Suggestions are given for accommodating these concerns through institutional policies and procedures. (MSE)

  7. QA for helical tomotherapy: Report of the AAPM Task Group 148

    SciTech Connect

    Langen, Katja M.; Papanikolaou, Niko; Balog, John; Crilly, Richard; Followill, David; Goddu, S. Murty; Grant, Walter III; Olivera, Gustavo; Ramsey, Chester R.; Shi Chengyu

    2010-09-15

    Helical tomotherapy is a relatively new modality with integrated treatment planning and delivery hardware for radiation therapy treatments. In view of the uniqueness of the hardware design of the helical tomotherapy unit and its implications in routine quality assurance, the Therapy Physics Committee of the American Association of Physicists in Medicine commissioned Task Group 148 to review this modality and make recommendations for quality assurance related methodologies. The specific objectives of this Task Group are: (a) To discuss quality assurance techniques, frequencies, and tolerances and (b) discuss dosimetric verification techniques applicable to this unit. This report summarizes the findings of the Task Group and aims to provide the practicing clinical medical physicist with the insight into the technology that is necessary to establish an independent and comprehensive quality assurance program for a helical tomotherapy unit. The emphasis of the report is to describe the rationale for the proposed QA program and to provide example tests that can be performed, drawing from the collective experience of the task group members and the published literature. It is expected that as technology continues to evolve, so will the test procedures that may be used in the future to perform comprehensive quality assurance for helical tomotherapy units.

  8. 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.

  9. 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,…

  10. 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…

  11. 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)

  12. The Effects of Study Tasks in a Computer-Based Chemistry Learning Environment

    NASA Astrophysics Data System (ADS)

    Urhahne, Detlef; Nick, Sabine; Poepping, Anna Christin; Schulz, Sarah Jayne

    2013-12-01

    The present study examines the effects of different study tasks on the acquisition of knowledge about acids and bases in a computer-based learning environment. Three different task formats were selected to create three treatment conditions: learning with gap-fill and matching tasks, learning with multiple-choice tasks, and learning only from text and figures without any additional tasks. Participants were 196 ninth-grade students who learned with a self-developed multimedia program in a pretest-posttest control group design. Research results reveal that gap-fill and matching tasks were most effective in promoting knowledge acquisition, followed by multiple-choice tasks, and no tasks at all. The findings are in line with previous research on this topic. The effects can possibly be explained by the generation-recognition model, which predicts that gap-fill and matching tasks trigger more encompassing learning processes than multiple-choice tasks. It is concluded that instructional designers should incorporate more challenging study tasks for enhancing the effectiveness of computer-based learning environments.

  13. Global oral health inequalities: dental caries task group--research agenda.

    PubMed

    Pitts, N; Amaechi, B; Niederman, R; Acevedo, A-M; Vianna, R; Ganss, C; Ismail, A; Honkala, E

    2011-05-01

    The IADR Global Oral Health Inequalities Task Group on Dental Caries has synthesized current evidence and opinion to identify a five-year implementation and research agenda which should lead to improvements in global oral health, with particular reference to the implementation of current best evidence as well as integrated action to reduce caries and health inequalities between and within countries. The Group determined that research should: integrate health and oral health wherever possible, using common risk factors; be able to respond to and influence international developments in health, healthcare, and health payment systems as well as dental prevention and materials; and exploit the potential for novel funding partnerships with industry and foundations. More effective communication between and among the basic science, clinical science, and health promotion/public health research communities is needed. Translation of research into policy and practice should be a priority for all. Both community and individual interventions need tailoring to achieve a more equal and person-centered preventive focus and reduce any social gradient in health. Recommendations are made for both clinical and public health implementation of existing research and for caries-related research agendas in clinical science, health promotion/public health, and basic science. PMID:21490233

  14. 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…

  15. Chronic treatment with sulbutiamine improves memory in an object recognition task and reduces some amnesic effects of dizocilpine in a spatial delayed-non-match-to-sample task.

    PubMed

    Bizot, Jean-Charles; Herpin, Alexandre; Pothion, Stéphanie; Pirot, Sylvain; Trovero, Fabrice; Ollat, Hélène

    2005-07-01

    The effect of a sulbutiamine chronic treatment on memory was studied in rats with a spatial delayed-non-match-to-sample (DNMTS) task in a radial maze and a two trial object recognition task. After completion of training in the DNMTS task, animals were subjected for 9 weeks to daily injections of either saline or sulbutiamine (12.5 or 25 mg/kg). Sulbutiamine did not modify memory in the DNMTS task but improved it in the object recognition task. Dizocilpine, impaired both acquisition and retention of the DNMTS task in the saline-treated group, but not in the two sulbutiamine-treated groups, suggesting that sulbutiamine may counteract the amnesia induced by a blockade of the N-methyl-D-aspartate glutamate receptors. Taken together, these results are in favor of a beneficial effect of sulbutiamine on working and episodic memory. PMID:15951087

  16. Task Effects on Eye Movements during Reading

    ERIC Educational Resources Information Center

    Kaakinen, Johanna K.; Hyona, Jukka

    2010-01-01

    The present study examined how proofreading and reading-for-comprehension instructions influence eye movements during reading. Thirty-seven participants silently read sentences containing compound words as target words while their eye movements were being recorded. We manipulated word length and frequency to examine how task instructions influence…

  17. 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…

  18. Effects of Task Roles on Participation and Productivity in the Intermediate Grades.

    ERIC Educational Resources Information Center

    Wilcox, Brad; Williams, Lisa; Reutzel, D. Ray

    1997-01-01

    Fourth and fifth graders participated in a study comparing the effects of traditional and modified collaboration models on participation and productivity outcomes. Students in traditional, modified, and control groups completed cooperative projects. Unlike the other groups, control group students had no assigned task roles. The modified and…

  19. 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.

  20. 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.

  1. The Effects of Distraction on Cognitive Task Performance during Toddlerhood

    ERIC Educational Resources Information Center

    Wyss, Nancy M.; Kannass, Kathleen N.; Haden, Catherine A.

    2013-01-01

    We investigated the effects of distraction on attention and task performance during toddlerhood. Thirty toddlers (24- to 26-month-olds) completed different tasks (2 of each: categorization, problem solving, memory, free play) in one of two conditions: No Distraction or Distraction. The results revealed that the distractor had varying effects on…

  2. The relationship between task-related and subsequent memory effects.

    PubMed

    de Chastelaine, Marianne; Rugg, Michael D

    2014-08-01

    The primary aim of this fMRI study was to assess the proposal that negative subsequent memory effects-greater activity for later forgotten relative to later remembered study items-are localized to regions demonstrating task-negative effects, and hence to potential components of the default mode network. Additionally, we assessed whether positive subsequent memory effects overlapped with regions demonstrating task-positive effects. Eighteen participants were scanned while they made easy or difficult relational judgments on visually presented word pairs. Easy and hard task blocks were interleaved with fixation-only rest periods. In the later unscanned test phase, associative recognition judgments were required on intact word pairs (studied pairs), rearranged pairs (pairs formed from words presented on different study trials) and new pairs. Subsequent memory effects were identified by contrasting the activity elicited by study pairs that went on to be correctly endorsed as intact versus incorrectly endorsed as rearranged. Task effects were identified by contrasting all study items and rest blocks. Both task-negative and task-positive effects were evident in widespread cortical regions and negative and positive subsequent memory effects were generally confined to task-negative and task-positive regions respectively. However, subsequent memory effects could be identified in only a fraction of task-sensitive voxels and, unlike task effects, were insensitive to the difficulty manipulation. The findings for the negative subsequent memory effects are consistent with recent proposals that the default mode network is functionally heterogeneous, and suggest that these effects are not accurately characterized as reflections of the modulation of the network as a whole. PMID:24615858

  3. Task group differences in cuticular lipids in the honey bee Apis mellifera.

    PubMed

    Kather, Ricarda; Drijfhout, Falko P; Martin, Stephen J

    2011-02-01

    Social insects are defined by their ability to divide labor among their numerous nestmates. This is achieved via a complex system of chemical communication that allows colonies to organize task activity so as to maximize the productivity of the colony. However, the mechanism by which social insects distinguish task groups among morphologically identical individuals remains unknown. Using the honey bee, Apis mellifera, as our model species, we investigated the presence of task-specific patterns in the cuticular lipids (n-alkanes, fatty acids, and alkenes) of bees. Cuticular lipids are known to play an essential role in the recognition processes of insects. We found task-specific features in the n-alkane and alkene profiles of bees, but no task-specific patterns in the fatty acid profile. Foragers, in particular, had elevated levels of n-alkanes relative to nurse and newly emerged bees, suggesting increased waterproofing. Newly emerged bees had low levels of cuticular lipids, supporting the Blank Slate theory and potentially explaining their acceptance into foreign colonies. PMID:21271278

  4. 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

  5. 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. PMID:26302190

  6. 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

  7. 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.

  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. 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. PMID:24070734

  10. 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…

  11. The Effects of Task-Specific Divergent-Thinking Training.

    ERIC Educational Resources Information Center

    Baer, John

    1996-01-01

    This study investigated what effect divergent-thinking training focusing on a single task would have on the creative performance of 79 seventh graders on a closely related task. Students received training in poetry-relevant, divergent-thinking skills. The training was found to have a significant impact on the students' creativity in writing…

  12. Effects of noise exposure and task demand on cardiovascular function.

    PubMed

    Wu, T N; Huang, J T; Chou, P F; Chang, P Y

    1988-01-01

    Cardiovascular effects under various noise-exposure and task-demand conditions were studied among 40 senior highschool students. The subjects consisted of 20 males and 20 females with a mean age of 16.7 +/- 0.7 years. All subjects had equivalent abacus performance ratings. Each subject was tested with a random sequence of six sessions. The time limit set for each session was 33 min. Six experimental sessions were constructed by a random combination of noise exposure (60, 85 or 90 dB (A] white noise) and task demand (task presence or task absence) variables. Blood pressure measures were taken at the beginning and ending phases of each session. A task-demand variable was defined as a conjoint of mental arithmetic (3 min) and abacus arithmetic (30 min). The results from the present study show that the effect of noise exposure on task performance is remarkable. Only noise exposure tended to influence the performance of male students in abacus arithmetic. The effect of task demand on blood pressure was higher than that of noise exposure. No interaction effect (noise exposure x task demand) on blood pressure, was found via analyses of within-subjects two-way ANOVA. PMID:3346087

  13. 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…

  14. Levels-of-processing effects in subject-performed tasks.

    PubMed

    Zimmer, H D; Engelkamp, J

    1999-09-01

    In memory for subject-performed tasks (SPTs), subjects encode a list of simple action phrases (e.g., thumb through a book, knock at the door) by performing these actions during learning. In three experiments, we investigated the size of the levels-of-processing effects in SPTs as compared with those in standard verbal learning tasks (VTs). Subjects under SPT and VT conditions learned lists of action phrases in a surface or a conceptual orienting task. Under both encoding conditions, the subjects recalled fewer items with surface orienting tasks than with conceptual orienting tasks, but the levels-of-processing effects were strongly reduced in the SPT condition. In the SPT condition, items that were encoded in a surface orienting task were still substantially recalled. The items were recalled almost as well as the conceptually encoded items in the VT condition. The distinct reduction of the levels-of-processing effect is caused by the fact that, in SPT encoding even with a verbal surface orienting task, subjects process conceptual information in order to perform the denoted action. We attribute the small conceptual advantage, which remains with SPT despite the conceptual processing for performing, to the fact that items are not as well integrated into memory as they are when conceptual processing is focused on the action component, rather than on the semantic contexts. This lower integration reduces the accessibility of items in the verbal surface task, even with SPT encoding. PMID:10540819

  15. A Study of Nonverbal Communication and Leadership Emergence in Task-Oriented and Informal Small Group Discussions.

    ERIC Educational Resources Information Center

    Schubert, Arline; And Others

    Fifty volunteer undergraduate students majoring in speech pathology and audiology at the University of North Dakota tested the following hypotheses: (1) leaders exhibit significantly more nonverbal cues than do nonleaders in task-oriented and informal small groups; (2) members of task-oriented small groups exhibit significantly more nonverbal cues…

  16. 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. PMID:25270561

  17. 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…

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

    PubMed

    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

  19. 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

  20. 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

  1. Fitness effects of group merging in a social insect.

    PubMed

    Costa, James T; Ross, Kenneth G

    2003-08-22

    Animal social groups often consist of non-relatives, a condition that arises in many cases because of group merging. Although indirect fitness contributions are reduced in such groups compared with those in groups composed of close kin, the genetic-heterogeneity hypothesis suggests that these groups may benefit from increased intracolony genetic variation, which may boost group performance through increased task efficiency or parasite resistance. We confirm one prediction of the task-efficiency explanation by demonstrating a genetic basis for task thresholds of socially important behaviours in eastern tent caterpillars. However, we found no evidence that the expanded range of task thresholds in mixed colonies translates into improved individual or colony performance in the field. By contrast, increased group size, a less commonly considered correlate of group mixing, was found to enhance individual fitness through its effects on larval growth. We conclude that fitness benefits offsetting the dilution of relatedness in heterogeneous social groups may often stem from augmented group size rather than increased genotypic diversity. PMID:12964997

  2. 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…

  3. 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.

  4. The effect of transcranial direct current stimulation on task processing and prioritisation during dual-task gait.

    PubMed

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

    2015-05-01

    The relationship between cognition and gait is often explored using a dual-task gait paradigm, which represents the ability to divide cognitive resources during walking. Recent evidence has suggested that the prefrontal cortex is involved in the allocation of cognitive resources during dual-task gait, though its precise role is unclear. Here, we used anodal and cathodal transcranial direct current stimulation (tDCS) to probe the role of the prefrontal cortex in the control of stride time variability (STV), trunk RoM and cognitive task performance during dual-task gait. As task difficulty has been shown to mediate the dual-task cost, we also manipulated walking speed to see whether the effects of tDCS on dual-task gait were influenced by walking difficulty. Ten adults performed a serial subtraction task when walking at either preferred walking speed or 25 % of preferred walking speed, before and after receiving tDCS of the left prefrontal cortex. Anodal tDCS reduced STV and the dual-task cost on STV and improved cognitive task performance. Cathodal tDCS increased STV and appeared to increase the dual-task cost on STV, but did not affect cognitive task performance. There was no effect of tDCS on trunk RoM, and the effects of tDCS were not mediated by walking speed. The effect of dual-task gait on stride time variability and cognitive task performance was altered by the application of tDCS, and these effects were polarity dependent. These results highlight the role of the prefrontal cortex in biasing task performance during dual-task gait and indicate that tDCS may be a useful tool for examining the role of the cortex in the control of dual-task gait. PMID:25724513

  5. 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.

  6. 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.

  7. Effects of Auditory Input in Individuation Tasks

    ERIC Educational Resources Information Center

    Robinson, Christopher W.; Sloutsky, Vladimir M.

    2008-01-01

    Under many conditions auditory input interferes with visual processing, especially early in development. These interference effects are often more pronounced when the auditory input is unfamiliar than when the auditory input is familiar (e.g. human speech, pre-familiarized sounds, etc.). The current study extends this research by examining how…

  8. Rightsizing Effectively. An APPA Task Force Report.

    ERIC Educational Resources Information Center

    APPA: Association of Higher Education Facilities Officers, Alexandria, VA.

    The Association of Higher Education Facilities Officers surveyed its members in 1993 regarding the effects of severe budget reductions. From 1,500 surveys mailed, there were 388 responses. The responses indicated the importance of a number of factors in institutions undergoing downsizing. Important factors included: a mission statement, the morale…

  9. Report of the Task Group on the Department of Energy Aviation Program

    SciTech Connect

    Not Available

    1992-02-01

    The Department of Energy (DOE) owns or leases approximately 43 aircraft of which 17 are airplanes and 26 are helicopters. About two-thirds of these aircraft are used for activities related to defense programs; these are all government owned and contractor operated. The other third of DOE`s aircraft is used by Bonneville Power Administration (BPA) and Western Area Power Administration (WAPA). These aircraft are primarily government owned and operated. In addition to transporting passengers, DOE aircraft are used for security operations, powerline and pipeline patrols, research and development activities, and aerial measurement and for the transport of hazardous materials. These operations are conducted at nine Field Offices under the organizational authority of eight DOE Program Secretarial Officers (PSOs). On July 24, 1991, a DOE-owned helicopter crashed at the Nevada Test Site resulting in the deaths of the five contractor employees on board. A DOE accident investigation board was convened, and an investigation into the causes of the crash was conducted. On November 19, 1991, a briefing of the preliminary results of the investigation was provided to the Assistant Secretary for Environment, Safety and Health (EH), the Assistant Secretary for Defense Programs (DP), and the Director, Office of Security Affairs (SA). On November 27, 1991, the Secretary of Energy directed the Assistant Secretary, EH, to convene and chair a Task Group with the PSOs to define the roles and responsibilities of DOE`s aviation program. Task group recommendations are presented.

  10. Report of the Task Group on the Department of Energy Aviation Program

    SciTech Connect

    Not Available

    1992-02-01

    The Department of Energy (DOE) owns or leases approximately 43 aircraft of which 17 are airplanes and 26 are helicopters. About two-thirds of these aircraft are used for activities related to defense programs; these are all government owned and contractor operated. The other third of DOE's aircraft is used by Bonneville Power Administration (BPA) and Western Area Power Administration (WAPA). These aircraft are primarily government owned and operated. In addition to transporting passengers, DOE aircraft are used for security operations, powerline and pipeline patrols, research and development activities, and aerial measurement and for the transport of hazardous materials. These operations are conducted at nine Field Offices under the organizational authority of eight DOE Program Secretarial Officers (PSOs). On July 24, 1991, a DOE-owned helicopter crashed at the Nevada Test Site resulting in the deaths of the five contractor employees on board. A DOE accident investigation board was convened, and an investigation into the causes of the crash was conducted. On November 19, 1991, a briefing of the preliminary results of the investigation was provided to the Assistant Secretary for Environment, Safety and Health (EH), the Assistant Secretary for Defense Programs (DP), and the Director, Office of Security Affairs (SA). On November 27, 1991, the Secretary of Energy directed the Assistant Secretary, EH, to convene and chair a Task Group with the PSOs to define the roles and responsibilities of DOE's aviation program. Task group recommendations are presented.

  11. 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. PMID:24897120

  12. 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

  13. Technology Task Autonomy and Gender Effects on Student Performance in Rural Middle School Science Classrooms

    ERIC Educational Resources Information Center

    Cantrell, Pamela; Sudweeks, Richard

    2009-01-01

    This project investigated the effects of technology task autonomy, teacher gender, and student gender on student achievement scores for students disaggregated by IEP and SES in middle school science classrooms. Participants were from the treatment group in a larger quasi-experimental design project that investigated the effects of integrated…

  14. 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…

  15. The Performance of Learning Tasks by the Church Session: Implications from the Literature on Leadership and the Group Task.

    ERIC Educational Resources Information Center

    Sparks, James Allen

    The parish administrative board--the Session--is an interactional group according to the operational definition as advanced by Gibb, Proshansky and Seidenberg. As a group it shares relatively common religious and moral values, as well as institutional goals. The perimeters of the Session's group life are clearly, if not legalistically, defined by…

  16. 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.

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

    PubMed

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

    2016-07-01

    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 therapy

  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. 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.

  20. 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

  1. 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…

  2. Orthographic Neighborhood and Concreteness Effects in the Lexical Decision Task

    ERIC Educational Resources Information Center

    Samson, Dana; Pillon, Agnesa

    2004-01-01

    The experiment reported here investigated the sensitivity of concreteness effects to orthographic neighborhood density and frequency in the visual lexical decision task. The concreteness effect was replicated with a sample of concrete and abstract words that were not matched for orthographic neighborhood features and in which concrete words turned…

  3. Age of Acquisition Effects in Translation Judgement Tasks

    ERIC Educational Resources Information Center

    Izura, Cristina; Ellis, Andrew W.

    2004-01-01

    The effects of age of acquisition (AoA) in the first (L1) and second (L2) languages of Spanish--English bilinguals were explored using a translation judgement task in which participants decided whether or not pairs of words in the two languages were translations of each other (i.e., had the same meaning). Experiment 1 found an effect of second…

  4. Effectiveness of Group Counseling Procedures.

    ERIC Educational Resources Information Center

    Gaetz, E. L.

    This paper includes both an evaluation of group counseling and a manual for training persons in group counseling. Thirty-five full-time graduate trained counselors were given 30 intensive hours of training in interpersonal skills and group work over a five-week period. In addition to this, all trainees operated a student group in conjunction with…

  5. 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.

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

    PubMed

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

    2015-11-01

    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. PMID:26520756

  7. Running effective meetings, running effective groups.

    PubMed

    Ogborn, S E

    1994-12-01

    Meetings are effective if they meet the objectives of each person involved in the least amount of time possible. Different strategies are needed for different types of meetings. Different leadership styles are necessary depending on the members' personality preferences and the stages of the group's development. Good leaders know how to adapt to these preferences and stages. PMID:10139146

  8. 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.

  9. 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. PMID:19878450

  10. Effect of Sudarshan Kriya (meditation) on gamma, alpha, and theta rhythm during working memory task

    PubMed Central

    Chandra, Sushil; Sharma, Greeshma; Mittal, Alok Prakash; Jha, Devendra

    2016-01-01

    Aims: The present study focuses on analyzing the effects of Sudarshan Kriya yoga (SKY) on brain signals during a working memory (WM) task. To envision the significant effects of SKY on WM capacity (WMC), we chose a control group for contriving a cogent comparison that could be corroborated using statistical tests. Subjects and Methods: A total of 25 subjects were taken in the study, of which 10 were allotted to a control group and 15 to an experimental group. Electroencephalograph was taken during a WM task, which was an automated operation span test before and after SKY with 90 days intervals. No SKY was given to the control group. Statistical Analysis Used: t-test and one-way ANOVA were applied. Results: SKY promoted the efficient use of energy and power spectral density (PSD) for different brain rhythms in the desired locations as depicted by the gamma (F8 channel), alpha, and theta 2 (F7 and FC5) bands. It was found that gamma PSD reduced for both phases of memory in the experimental group. Alpha energy increased during the retrieval phase in the experimental group after SKY. Theta 1 rhythm was not affected by SKY, but theta 2 had shown left hemispheric activation. Theta rhythm was associated with memory consolidation. Conclusions: SKY had shown minimized energy losses while performing the task. SKY can improve WMC by changing the brain rhythms such that energy is utilized efficiently in performing the task. PMID:26865775

  11. Effect of post-training unilateral labyrinthectomy in a spatial orientation task by guinea pigs.

    PubMed

    Chapuis, N; Krimm, M; de Waele, C; Vibert, N; Berthoz, A

    1992-11-15

    The effects of unilateral labyrinthectomy in guinea pigs have been studied on an angular orientation task consisting, in an open field, of running to a hidden goal oriented at 45 degrees with respect to the cephalocaudal axis of the animal placed in a starting-box. The task was conducted in light but in an homogeneous environment, i.e. without visual, auditory or olfactory cues indicating the location of the goal. A second group of animals was submitted to a similar task running to a hidden goal but the place of the goal was indicated by a colored card. All the animals were trained before the lesion and tested in their respective task for 1 month after the lesion. In the task conducted without conspicuous cues, animals were dramatically disturbed. In contrast, animals pretrained in the visually guided task were not impaired after the lesion. These results point out the important role of vestibular information in performing spatial tasks based on angular estimation, since, even if proprioceptive and visuokinesthetic information remain available, subjects seemed not able to maintain a correct angular trajectory. The trajectories being not disturbed in the visually guided task, one can exclude the hypothesis that such deficit was due to a purely motor disturbance. PMID:1466778

  12. The Effect of Various Dual Task Training Methods with Gait on the Balance and Gait of Patients with Chronic Stroke

    PubMed Central

    An, Ho-Jung; Kim, Jae-Ic; Kim, Yang-Rae; Lee, Kyoung-Bo; Kim, Dai-Joong; Yoo, Kyung-Tae; Choi, Jung-Hyun

    2014-01-01

    [Purpose] This study examined the effects of various dual task gait training methods (motor dual task gait training, cognitive dual task gait training, and motor and cognitive dual task gait training) on the balance and gait abilities of chronic stroke patients. [Subjects and Methods] Thirty-three outpatients performed dual task gait training for 30 minutes per day, three times a week, for eight weeks from June to August, 2012. Balance ability was measured pre-and posttest using the stability test index, the weight distribution index, the functional reach test, the timed up and go test, and the four square step test. Gait ability was measured by the 10 m walk test and a 6 min walk test before and after the training. The paired t-test was used to compare measurements before and after training within each group, and ANOVA was used to compare measurements before and after training among the groups. [Results] Comparisons within each group indicated significant differences in all variables between before and after the training in all three groups. Comparison between the groups showed that the greatest improvements were seen in all tests, except for the timed up and go test, following motor and cognitive dual task gait training. [Conclusion] In a real walking environment, the motor and cognitive dual task gait training was more effective at improving the balance and gait abilities of chronic stroke patients than either the motor dual task gait training or the cognitive dual task gait training alone. PMID:25202199

  13. Differential effects of emotionally versus neutrally cued autobiographical memories on performance of a subsequent cognitive task: effects of task difficulty

    PubMed Central

    Young, Kymberly D.; Erickson, Kristine; Drevets, Wayne C.

    2012-01-01

    Attention is a limited resource, and in order to improve processing of the attended information, competing processes must be suppressed. Although it is well established that an experimentally induced change in mood state comprises one type of competing process that can impair performance on a subsequent task, no study has investigated whether an emotionally valenced autobiographical memory (AM) also can alter performance on a subsequent task. We therefore examined the effects of AM recall on cognitive performance. Healthy participants (n = 20 per experiment) recalled AMs in response to positive, negative, and neutral cue words. Following each AM participants completed a simple perceptual task (Experiment 1) or solved moderately difficult subtraction problems (Experiment 2). In Experiment 1 participants performed less accurately following exposure to positive or negative versus neutral cue words (ps < 0.001), and also were less accurate following negative versus positive cue words (p < 0.001). In Experiment 2, in contrast, no difference in accuracy or response times reached statistical significance. Performance accuracy even trended toward being higher following exposure to negative versus neutral cue words (p = 0.08). The results of Experiment 1 suggested that recalling emotionally salient AMs reduces the attention directed toward a simple continuous performance task administered immediately following the AM task, conceivably due to persistent contemplation of the AM. The negative results of Experiment 2 suggested that the effect of AMs on attention was attenuated, however, by increasing the difficulty of the subsequent task. Our results have implications for patients with major depressive disorder (MDD), as performing cognitively demanding tasks may allow them to attenuate the impairing effects of negative rumination on cognition. PMID:23060823

  14. Student Performance in Water Pouring and Balance Beam Tasks: Effect of Manipulation of Perceptual Field Factor.

    ERIC Educational Resources Information Center

    Niaz, Mansoor

    1988-01-01

    The effect of manipulation of the perceptual field factors on undergraduate student performance in proportional reasoning tasks was investigated. Evidence was found to support the hypothesis that the manipulation of the perceptual field factor can affect student performance. Reports data correlated with the Group Embedded-Figures Test. (CW)

  15. 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…

  16. 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…

  17. 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…

  18. Children's Choice Strategies: The Effects of Age and Task Demands

    ERIC Educational Resources Information Center

    Bereby-Meyer, Yoella; Assor, Avi; Katz, Idit

    2004-01-01

    Two experiments examined the effect of age and cognitive demands on children's choice strategies. Children aged 8-9 and 12-13 years were asked to choose among either two or four products that differed in several attributes of varying importance to them. Choice tasks were designed to differentiate between the lexicographic and the equal-weighting…

  19. The Effects of Assignment Format and Choice on Task Completion

    ERIC Educational Resources Information Center

    Hua, Youjia; Lee, David; Stansbery, Samuel; McAfee, James

    2014-01-01

    Modifying task presentation format and providing opportunities to choose are two effective procedures teachers can use to improve academic productivity for students with learning difficulties. Combining the two procedures may result in academic interventions that teachers can use without significantly changing the curriculum. The present study…

  20. The Effects of Microcomputers on Children's Attention to Reading Tasks.

    ERIC Educational Resources Information Center

    Zuk, Dorie; Danner, Fred

    A study investigated the effects of microcomputers on children's attention to reading tasks and the relationship between previous reading achievement and grade level on such attentional behavior. Fifty-five third and fifth graders read two stories each, one presented on a microcomputer and one presented in print. Television cartoons and rock music…

  1. Perspective effects in nondeontic versions of the Wason selection task.

    PubMed

    Staller, A; Sloman, S A; Ben-Zeev, T

    2000-04-01

    Perspective effects in the Wason four-card selection task occur when people choose mutually exclusive sets of cards depending on the perspective they adopt when making their choice. Previous demonstrations of perspective effects have been limited to deontic contexts--that is, problem contexts that involve social duty, like permissions and obligations. In three experiments, we demonstrate perspective effects in nondeontic contexts, including a context much like the original one employed by Wason (1966, 1968). We suggest that perspective effects arise whenever the task uses a rule that can be interpreted biconditionally and different perspectives elicit different counterexamples that match the predicted choice sets. This view is consistent with domain-general theories but not with domain-specific theories of deontic reasoning--for example, pragmatic reasoning schemas and social contract theory--that cannot explain perspective effects in nondeontic contexts. PMID:10881557

  2. Nonstrategic contributions to putatively strategic effects in selective attention tasks.

    PubMed

    Risko, Evan F; Blais, Chris; Stolz, Jennifer A; Besner, Derek

    2008-08-01

    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 compatible trials but decreases on incompatible trials. This confound is demonstrated to lead to an overestimation in the magnitude of the proportion compatible effect in the context of both a Stroop and a Simon task. Implications for previous research and directions for future research using proportion compatible manipulations are discussed. PMID:18665744

  3. 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…

  4. Effects of task complexity on rhythmic reproduction performance in adults.

    PubMed

    Iannarilli, Flora; Vannozzi, Giuseppe; Iosa, Marco; Pesce, Caterina; Capranica, Laura

    2013-02-01

    The aim of the present study was to investigate the effect of task complexity on the capability to reproduce rhythmic patterns. Sedentary musically illiterate individuals (age: 34.8±4.2 yrs; M±SD) were administered a rhythmic test including three rhythmic patterns to be reproduced by means of finger-tapping, foot-tapping and walking. For the quantification of subjects' ability in the reproduction of rhythmic patterns, qualitative and quantitative parameters were submitted to analysis. A stereophotogrammetric system was used to reconstruct and evaluate individual performances. The findings indicated a good internal stability of the rhythmic reproduction, suggesting that the present experimental design is suitable to discriminate the participants' rhythmic ability. Qualitative aspects of rhythmic reproduction (i.e., speed of execution and temporal ratios between events) varied as a function of the perceptual-motor requirements of the rhythmic reproduction task, with larger reproduction deviations in the walking task. PMID:23452943

  5. 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.

  6. Regulatory Match Effects on a Modified Wisconsin Card Sort Task

    PubMed Central

    Maddox, W. Todd; Filoteo, J. Vincent; Glass, Brian D.; Markman, Arthur B.

    2009-01-01

    The Wisconsin Card Sorting Task (WCST; Heaton, 1980) is commonly used to assess concept formation and set shifting. Cognitive research suggests that set shifting performance is enhanced by a match between a person’s regulatory focus (promotion focus: attempting to earn an entry into a cash drawing; prevention focus: attempting to avoid losing an entry into the drawing) and the task reward structure (gains: attempting to maximize points gained; losses: attempting to minimize points lost). A regulatory match results when attempting to earn an entry by maximizing points or attempting to avoid losing an entry by minimizing losses. We test the hypothesis that performance on a modified WCST is accentuated in younger, healthy participants when there is a match between the global performance incentive and the local task reward structure. As predicted, participants in a match showed better set shifting but equivalent initial concept formation when compared to participants in a mismatch. Further, relative to a baseline control group, mismatch participants were significantly worse at set shifting than were participants in a regulatory match. These results suggest that set shifting performance might be impacted by incentive and task reward factors in ways that have not been considered previously. PMID:20128935

  7. 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

  8. Task Engagement in Young Adults with High-Functioning Autism Spectrum Disorders: Generalization Effects of Behavioral Skills Training

    ERIC Educational Resources Information Center

    Palmen, Annemiek; Didden, Robert

    2012-01-01

    This study evaluated the effectiveness of a behavioral skills training package on task engagement in six young adults with high-functioning ASD who worked in a regular job-training setting. Experimental sessions were implemented in a small-group training format in a therapy room using unknown tasks. Data were collected on participant's off-task…

  9. 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.

  10. 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. PMID:26741255

  11. 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…

  12. 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…

  13. 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

  14. Comparing the neural distance effect derived from the non-symbolic comparison and the same-different task.

    PubMed

    Smets, Karolien; Gebuis, Titia; Reynvoet, Bert

    2013-01-01

    As a result of the representation of numerosities, more accurate and faster discrimination between two numerosities is observed when the distance between them increases. In previous studies, the comparison and same-different task were most frequently used to investigate this distance effect. Recently, it was questioned whether the non-symbolic distance effects derived from these tasks originate at the same level. In the current study, we examined the behavioral and neural distance effects of the comparison and same-different task to assess potential differences between both tasks. Participants were first year university students. Each participant completed both tasks, while their reaction time, accuracy and brain activity on predefined components was measured. The early N1-P2p transition and the P2p component on temporo-occipital (TO) and inferior parietal (IP) electrode groups were considered, as well as the late P3 component on a central (C) electrode group. The results showed that the behavioral distance effects from both tasks were comparable, although participants' performance was worse on the same-different task. The neural results revealed similar effects of distance on the mean amplitudes for the early components for both tasks (all p's < 0.02) and an additional effect of task difficulty on the mean amplitudes of these components. Similar as in previous studies, we found a (marginally) significant increase in mean amplitude of the later P3 component with increasing distance for the comparison (p = 0.07), but not for the same-different task. Apparently, the initial stages of number processing are comparable for both tasks, but an additional later stage is only present for the comparison task. The P3 effect would be indicative of this decisional stage, which was previously proposed to underlie the comparison distance effect (CDE). PMID:23420710

  15. 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

  16. The management of respiratory motion in radiation oncology report of AAPM Task Group 76

    SciTech Connect

    Keall, Paul J.; Mageras, Gig S.; Balter, James M.

    2006-10-15

    This document is the report of a task group of the AAPM and has been prepared primarily to advise medical physicists involved in the external-beam radiation therapy of patients with thoracic, abdominal, and pelvic tumors affected by respiratory motion. This report describes the magnitude of respiratory motion, discusses radiotherapy specific problems caused by respiratory motion, explains techniques that explicitly manage respiratory motion during radiotherapy and gives recommendations in the application of these techniques for patient care, including quality assurance (QA) guidelines for these devices and their use with conformal and intensity modulated radiotherapy. The technologies covered by this report are motion-encompassing methods, respiratory gated techniques, breath-hold techniques, forced shallow-breathing methods, and respiration-synchronized techniques. The main outcome of this report is a clinical process guide for managing respiratory motion. Included in this guide is the recommendation that tumor motion should be measured (when possible) for each patient for whom respiratory motion is a concern. If target motion is greater than 5 mm, a method of respiratory motion management is available, and if the patient can tolerate the procedure, respiratory motion management technology is appropriate. Respiratory motion management is also appropriate when the procedure will increase normal tissue sparing. Respiratory motion management involves further resources, education and the development of and adherence to QA procedures.

  17. 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.

  18. Code of Ethics for the American Association of Physicists in Medicine: report of Task Group 109.

    PubMed

    Serago, Christopher F; Adnani, Nabil; Bank, Morris I; BenComo, Jose A; Duan, Jun; Fairobent, Lynne; Freedman, D Jay; Halvorsen, Per H; Hendee, William R; Herman, Michael G; Morse, Richard K; Mower, Herbert W; Pfeiffer, Douglas E; Root, William J; Sherouse, George W; Vossler, Matthew K; Wallace, Robert E; Walters, Barbara

    2009-01-01

    A comprehensive Code of Ethics for the members of the American Association of Physicists in Medicine (AAPM) is presented as the report of Task Group 109 which consolidates previous AAPM ethics policies into a unified document. The membership of the AAPM is increasingly diverse. Prior existing AAPM ethics polices were applicable specifically to medical physicists, and did not encompass other types of members such as health physicists, regulators, corporate affiliates, physicians, scientists, engineers, those in training, or other health care professionals. Prior AAPM ethics policies did not specifically address research, education, or business ethics. The Ethics Guidelines of this new Code of Ethics have four major sections: professional conduct, research ethics, education ethics, and business ethics. Some elements of each major section may be duplicated in other sections, so that readers interested in a particular aspect of the code do not need to read the entire document for all relevant information. The prior Complaint Procedure has also been incorporated into this Code of Ethics. This Code of Ethics (PP 24-A) replaces the following AAPM policies: Ethical Guidelines for Vacating a Position (PP 4-B); Ethical Guidelines for Reviewing the Work of Another Physicist (PP 5-C); Guidelines for Ethical Practice for Medical Physicists (PP 8-D); and Ethics Complaint Procedure (PP 21-A). The AAPM Board of Directors approved this Code or Ethics on July 31, 2008. PMID:19235389

  19. Clinical use of electronic portal imaging: report of AAPM Radiation Therapy Committee Task Group 58.

    PubMed

    Herman, M G; Balter, J M; Jaffray, D A; McGee, K P; Munro, P; Shalev, S; Van Herk, M; Wong, J W

    2001-05-01

    AAPM Task Group 58 was created to provide materials to help the medical physicist and colleagues succeed in the clinical implementation of electronic portal imaging devices (EPIDs) in radiation oncology. This complex technology has matured over the past decade and is capable of being integrated into routine practice. However, the difficulties encountered during the specification, installation, and implementation process can be overwhelming. TG58 was charged with providing sufficient information to allow the users to overcome these difficulties and put EPIDs into routine clinical practice. In answering the charge, this report provides; comprehensive information about the physics and technology of currently available EPID systems; a detailed discussion of the steps required for successful clinical implementation, based on accumulated experience; a review of software tools available and clinical use protocols to enhance EPID utilization; and specific quality assurance requirements for initial and continuing clinical use of the systems. Specific recommendations are summarized to assist the reader with successful implementation and continuing use of an EPID. PMID:11393467

  20. 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.

  1. 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…

  2. Small-Group Composition and Peer Effects

    ERIC Educational Resources Information Center

    Wilkinson, Ian A. G.; Fung, Irene Y. Y.

    2002-01-01

    This paper reviews research on grouping of students within classes and its effects on learning. Primary consideration is given to grouping and mixing students by ability, though consideration is also given to grouping and mixing students by ethnicity and gender as well as to research on the effects of group size. Results of meta-analyses of…

  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. 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…

  5. The effect of task order predictability in audio-visual dual task performance: Just a central capacity limitation?

    PubMed Central

    Töllner, Thomas; Strobach, Tilo; Schubert, Torsten; Müller, Hermann J.

    2012-01-01

    In classic Psychological-Refractory-Period (PRP) dual-task paradigms, decreasing stimulus onset asynchronies (SOA) between the two tasks typically lead to increasing reaction times (RT) to the second task and, when task order is non-predictable, to prolonged RTs to the first task. Traditionally, both RT effects have been advocated to originate exclusively from the dynamics of a central bottleneck. By focusing on two specific electroencephalographic brain responses directly linkable to perceptual or motor processing stages, respectively, the present study aimed to provide a more detailed picture as to the origin(s) of these behavioral PRP effects. In particular, we employed 2-alternative forced-choice (2AFC) tasks requiring participants to identify the pitch of a tone (high versus low) in the auditory, and the orientation of a target object (vertical versus horizontal) in the visual, task, with task order being either predictable or non-predictable. Our findings show that task order predictability (TOP) and inter-task SOA interactively determine the speed of (visual) perceptual processes (as indexed by the PCN timing) for both the first and the second task. By contrast, motor response execution times (as indexed by the LRP timing) are influenced independently by TOP for the first, and SOA for the second, task. Overall, this set of findings complements classical as well as advanced versions of the central bottleneck model by providing electrophysiological evidence for modulations of both perceptual and motor processing dynamics that, in summation with central capacity limitations, give rise to the behavioral PRP outcome. PMID:22973208

  6. 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. PMID:18078225

  7. The effects of achievement goals on performance, enjoyment, and practice of a novel motor task.

    PubMed

    Kavussanu, Maria; Morris, Rebecca L; Ring, Christopher

    2009-10-01

    We examined the effects of trichotomous achievement goals on performance, enjoyment, and practice of a golf-putting task. Male (n = 39) and female (n = 63) undergraduate students participated in the experiment in exchange for course credit. Participants were assigned to a mastery, performance-approach, or performance-avoidance goal condition and completed seven blocks of 10 trials (one for baseline, four for the experimental phase, and two for the transfer phase) of a golf-putting task. Distance from the target was measured and performance measures of accuracy and consistency were calculated. Self-reported enjoyment during the baseline and experimental phases and practice during a 5-min period before and following the experimental task were also assessed. Performance accuracy and consistency improved similarly among the three groups. Individuals in all three conditions reported enjoying the task to the same extent. Mastery participants practiced for longer than performance-approach participants during the practice period. Performance-avoidance participants did not differ significantly from the other two groups. The three goals were equally effective in promoting performance and enjoyment of the golf-putting task. The differential practice results for the two performance goals suggest that they should be considered separately. PMID:19735037

  8. 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

  9. Effect of dual-task training on postural stability in children with infantile hemiparesis

    PubMed Central

    Elhinidi, Elbadawi Ibrahim Mohammad; Ismaeel, Marwa Mostafa Ibrahim; El-Saeed, Tamer Mohamed

    2016-01-01

    [Purpose] The aim of this study was to evaluate the influence of using a selected dual-task training program to improve postural stability in infantile hemiparesis. [Subjects and Methods] Thirty patients participated in this study; patients were classified randomly into two equal groups: study and control groups. Both groups received conventional physical therapy treatment including mobility exercises, balance exercises, gait training exercises, and exercises to improve physical conditioning. In addition, the study group received a selected dual-task training program including balance and cognitive activities. The treatment program was conducted thrice per week for six successive weeks. The patients were assessed with the Biodex Balance System. These measures were recorded two times: before the application of the treatment program (pre) and after the end of the treatment program (post). [Results] There was a significant improvement for both groups; the improvement was significantly higher in the study group compared to the control group. [Conclusion] The selected dual-task training program is effective in improving postural stability in patients with infantile hemiparesis when added to the conventional physical therapy program. PMID:27134376

  10. 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

  11. 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. PMID:26180341

  12. 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.

  13. 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

  14. 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

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

    PubMed Central

    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. PMID:26579024

  16. 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.

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

    PubMed

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

    2015-05-01

    [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. 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. PMID:25193796

  19. 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. PMID:23106836

  20. Medical accelerator safety considerations: report of AAPM Radiation Therapy Committee Task Group No. 35.

    PubMed

    Purdy, J A; Biggs, P J; Bowers, C; Dally, E; Downs, W; Fraass, B A; Karzmark, C J; Khan, F; Morgan, P; Morton, R

    1993-01-01

    Ensuring safe operation for a medical accelerator is a difficult task. Users must assume more responsibility in using contemporary equipment. Additionally, users must work closely with manufacturers in promoting the safe and effective use of such complex equipment. Complex treatment techniques and treatment modality changeover procedures merit detailed, unambiguous written procedural instruction at the control console. A thorough "hands on" training period after receiving instructions, and before assuming treatment responsibilities, is essential for all technologists. Unambiguous written instructions must also be provided to guide technologists in safe response when equipment malfunctions or exhibits unexpected behavior or after any component has been changed or readjusted. Technologists should be given a written list of the appropriate individuals to consult when unexpected machine behavior occurs. They should be assisted in identifying aberrant behavior of equipment. Many centers already provide this instruction, but others may not. Practiced response and discussion with technologists should be a part of an ongoing quality assurance program. An important aspect of a safety program is the need for continuous vigilance. Table III gives a summary of a comprehensive safety program for medical accelerators. Table IV gives a list of summary recommendations as an example of how one might mitigate the consequences of an equipment failure and improve procedures and operator response in the context of the environment described. Most of these recommendations can be implemented almost immediately at any individual treatment center. PMID:8413039

  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. 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…

  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. 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. PMID:26439112

  5. Attention effects on the processing of task-relevant and task-irrelevant speech sounds and letters

    PubMed Central

    Mittag, Maria; Inauri, Karina; Huovilainen, Tatu; Leminen, Miika; Salo, Emma; Rinne, Teemu; Kujala, Teija; Alho, Kimmo

    2013-01-01

    We used event-related brain potentials (ERPs) to study effects of selective attention on the processing of attended and unattended spoken syllables and letters. Participants were presented with syllables randomly occurring in the left or right ear and spoken by different voices and with a concurrent foveal stream of consonant letters written in darker or lighter fonts. During auditory phonological (AP) and non-phonological tasks, they responded to syllables in a designated ear starting with a vowel and spoken by female voices, respectively. These syllables occurred infrequently among standard syllables starting with a consonant and spoken by male voices. During visual phonological and non-phonological tasks, they responded to consonant letters with names starting with a vowel and to letters written in dark fonts, respectively. These letters occurred infrequently among standard letters with names starting with a consonant and written in light fonts. To examine genuine effects of attention and task on ERPs not overlapped by ERPs associated with target processing or deviance detection, these effects were studied only in ERPs to auditory and visual standards. During selective listening to syllables in a designated ear, ERPs to the attended syllables were negatively displaced during both phonological and non-phonological auditory tasks. Selective attention to letters elicited an early negative displacement and a subsequent positive displacement (Pd) of ERPs to attended letters being larger during the visual phonological than non-phonological task suggesting a higher demand for attention during the visual phonological task. Active suppression of unattended speech during the AP and non-phonological tasks and during the visual phonological tasks was suggested by a rejection positivity (RP) to unattended syllables. We also found evidence for suppression of the processing of task-irrelevant visual stimuli in visual ERPs during auditory tasks involving left-ear syllables

  6. Respiratory sinus arrhythmia responses to cognitive tasks: effects of task factors and RSA indices.

    PubMed

    Overbeek, Thérèse J M; van Boxtel, Anton; Westerink, Joyce H D M

    2014-05-01

    Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable results. In 83 healthy subjects, we studied RSA responses to a working memory task requiring varying levels of cognitive control and a perceptual attention task not requiring strong cognitive control. RSA responses were quantified in the time and frequency domain and were additionally corrected for differences in mean interbeat interval and respiration rate, resulting in eight different RSA indices. The two tasks were clearly differentiated by heart rate and facial EMG reference measures. Cognitive control induced inhibition of RSA whereas perceptual attention generally did not. However, the results show several differences between different RSA indices, emphasizing the importance of methodological variables. Age and sex did not influence the results. PMID:24561100

  7. Evaluating the subject-performed task effect in healthy older adults: relationship with neuropsychological tests

    PubMed Central

    Silva, Ana Rita; Pinho, Maria Salomé; Souchay, Céline; Moulin, Christopher J. A.

    2015-01-01

    Background An enhancement in recall of simple instructions is found when actions are performed in comparison to when they are verbally presented – the subject-performed task (SPT) effect. This enhancement has also been found with older adults. However, the reason why older adults, known to present a deficit in episodic memory, have a better performance for this type of information remains unclear. In this article, we explored this effect by comparing the performance on the SPT task with the performance on other tasks, in order to understand the underlying mechanisms that may explain this effect. Objective We hypothesized that both young and older adult groups should show higher recall in SPT compared with the verbal learning condition, and that the differences between age groups should be lower in the SPT condition. We aimed to explore the correlations between these tasks and known neuropsychological tests, and we also measured source memory for the encoding condition. Design A mixed design was used with 30 healthy older adults, comparing their performance with 30 healthy younger adults. Each participant was asked to perform 16 simple instructions (SPT condition) and to only read the other 16 instructions (Verbal condition – VT). The test phase included a free recall task. Participants were also tested with a set of neuropsychological measures (speed of processing, working memory and verbal episodic memory). Results The SPT effect was found for both age groups; but even for SPT materials, group differences in recall persisted. Source memory was found to be preserved for the two groups. Simple correlations suggested differences in correlates of SPT performance between the two groups. However, when controlling for age, the SPT and VT tasks correlate with each other, and a measure of episodic memory correlated moderately with both SPT and VT performance. Conclusions A strong effect of SPT was observed for all but one, which still displayed the expected aging

  8. The effects of a concurrent motor task on walking in Alzheimer's disease.

    PubMed

    Wittwer, Joanne E; Webster, Kate E; Hill, Keith

    2014-01-01

    The important relationship between cognition and gait in people with dementia has been explored with dual-task studies using added cognitive tasks. Effects of less commonly studied but also attention-dividing motor dual-tasks are important to assess in this group as they are common in everyday function and may affect gait differently from cognitive dual-tasks. They may also be easier to comprehend allowing their application with more severe cognitive impairment. The aim of this study was to evaluate the effects and feasibility of a motor dual-task (MDT) on gait measures in people with Alzheimer's disease (AD). Thirty people (15 men, mean age ± SD, 80.2 ± 5.8 years) with a diagnosis of probable AD (MMSE range 8-28) walked on an electronic walkway (i) at self-selected comfortable pace and (ii) at self-selected comfortable pace while carrying a tray and glasses. The MDT produced significant decreases in velocity (Baseline=111.5 ± 26.5 cm/s, MDT=96.8 ± 25.7 cm/s, p<0.001) and stride length (Baseline=121.4 ± 21.6 cm, MDT=108.1 ± 21.0 cm, p<0.001) with medium effect sizes, and increased stride time (Baseline=1.11 ± 0.11s, MDT=1.14 ± 0.12s, p=0.001) with small effect size. Measures of spatial (Baseline=3.2 ± 1.0%, MDT=3.9 ± 1.5%, p=0.006) and temporal (Baseline=2.4 ± 0.8%, MDT=2.8 ± 0.8%, p=0.008) variability increased with the motor dual-task, with medium effect sizes. A trend for motor dual-task changes in gait measures to increase with greater disease severity did not reach significance. The tray-carrying task was feasible, even for participants with severe cognitive decline. Further comparison of different types of motor and cognitive dual-tasks may contribute to development of a framework for clinical intervention to improve reduced dual-task walking capacity in people with AD. PMID:23978694

  9. 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. PMID:26970577

  10. Performance and workload effects for full versus partial automation in a high-fidelity multi-task system

    NASA Astrophysics Data System (ADS)

    Scallen, Stephen Francis

    This thesis evaluated theoretical predictions concerning performance and workload effects of the implementation of adaptive allocation. Five experiments are reported in which adaptive allocation was implemented in a multiple task aviation simulation with component tracking, monitoring, and target identification sub-tasks. Experiments 1 and 2 empirically determined input values for the tracking task which produced controlled levels of tracking difficulty. Experiment 3 exposed pilots and non pilots to single, dual, and multiple task combinations under independent and linked sub-tasks configurations. Results indicated that performance on all sub-tasks was sensitive to the number of concurrent tasks and further indicated that the non-linked system configuration contributed to reduced pilot efficiency. Experiment 4 implemented adaptive allocation for the tracking sub-task based on a model which identified an increase in tracking error during the initial presentation of a target. During initial target presentation, tracking control was either fully or partially allocated to the system for a brief period, after which full control was returned. Results indicated performance benefits on all tasks for both full and partial adaptive allocation strategies and confirmed that an independent task configuration may underestimate pilot efficiency. Experiment 5 extended the implementation of adaptive allocation to include adaptive display layout. It compared functional grouping of sub-tasks displays based on principles of perceptual and processing proximity. Results provided support for the implementation of adaptive display design in general but failed to support the specific layouts derived from the proximity conception.

  11. Inservice Training -- Workmeetings, Task Forces -- Etc.: How to Plan for a Successful Group Session. Training Monograph One.

    ERIC Educational Resources Information Center

    Padzensky, Herb

    The processes involved in staging successful inservice training, staff meetings, and task force sessions are described. Examples are provided and details are given for four phases of preparation: preplanning (including identification of need, setting priority objectives, and determining the type of group session); planning (covering such aspects…

  12. 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…

  13. 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…

  14. Effects of vocal training on respiratory kinematics during singing tasks.

    PubMed

    Mendes, Ana P; Brown, W S; Sapienza, Christine; Rothman, Howard B

    2006-01-01

    This longitudinal study determined the effects of vocal training (VT) on respiratory kinematics and muscle activity during singing tasks. Four voice students, 3 females and 1 male, were recorded during singing tasks once a semester for 3 consecutive semesters. Respiratory kinematic measures included lung volume, rib cage (RCE) and abdominal excursions (ABE). Surface electromyographic measures included burst duration (BD) and peak amplitude (PA) of the pectoralis major, rectus abdominis and external oblique muscles. Descriptive statistics revealed that RCE and ABE increased from the 1st to the 2nd semester, but decreased from the 2nd to the 3rd semester of VT. Overall, mean BD decreased from the 1st to the 2nd semester and increased from the 2nd to the 3rd semester. Mean PA increased from the 1st to the 2nd semester and decreased from the 2nd to the 3rd semester of VT. RCE and muscle force generation of the above muscles increased as the demand level and the length of the phonatory tasks increased. Interpretation of the results suggests that the respiratory system is highly responsive to VT, after only 3 semesters of training. PMID:16966837

  15. Investigating Effects of Task Structure on EFL Learner's Oral Performance

    ERIC Educational Resources Information Center

    Rahimpour, Massoud; Mehrang, Faezeh

    2010-01-01

    It is argued that tasks with different structures yield different performances in terms of accuracy, fluency and complexity. The present study is thus an attempt to investigate the impact of task structure on second language task performance. Thirty two upper-intermediate Iranian learners of English performed two narrative tasks (Structured vs.…

  16. 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

  17. The Effects of a Group Contingency Strategy on Behaviorally Disordered Students in Physical Education.

    ERIC Educational Resources Information Center

    Vogler, E. William; French, Ron W.

    1983-01-01

    A study investigated: (1) the effectiveness of a group contingency behavior modification strategy on behaviorally disordered students in a physical education class; (2) each student's response in relation to the group; and (3) the effects of age differences on results. The strategy increased time on task for both individuals and groups. (Author/PP)

  18. Air exchange effectiveness of conventional and task ventilation for offices

    SciTech Connect

    Fisk, W.J.; Faulkner, D.; Prill, R.J.

    1991-12-01

    Air quality and comfort complaints within large buildings are often attributed to air distribution problems. We define three air exchange effectiveness parameters related to air distribution. The first two indicate the indoor air flow pattern (i.e., the extent of short circuiting, mixing, or displacement flow) for an entire building or region. The third parameter is most useful for assessments of the spatial variability of ventilation. We also define the air diffusion effectiveness which indicates the air flow pattern within specific rooms or sections of buildings. The results of measurements of these parameters in US office buildings by the authors and other researchers are reviewed. Almost all measurements indicate very limited short circuiting or displacement flow between locations of air supply and removal. However, a moderate degree of short circuiting is evident from a few measurements in rooms with heated supply air. The results of laboratory-based measurements by the authors are consistent with the field data. Our measurements in office buildings do indicate that ventilation rates can vary substantially between indoor locations, probably due to variation in air supply rates between locations rather than variation in the indoor air flow patterns. One possible method of improving air distribution is to employ task ventilation with air supplied closer to the occupant`s breathing zone. We have evaluated two task ventilation systems in a laboratory setting. During most operating conditions, these systems did not provide a region of substantially increased ventilation where occupants breath. However, both systems are capable of providing substantially enhanced ventilation at the breathing zone under some operating conditions. Therefore, task ventilation is a potential option for using ventilation air more effectively.

  19. Air exchange effectiveness of conventional and task ventilation for offices

    SciTech Connect

    Fisk, W.J.; Faulkner, D.; Prill, R.J.

    1991-12-01

    Air quality and comfort complaints within large buildings are often attributed to air distribution problems. We define three air exchange effectiveness parameters related to air distribution. The first two indicate the indoor air flow pattern (i.e., the extent of short circuiting, mixing, or displacement flow) for an entire building or region. The third parameter is most useful for assessments of the spatial variability of ventilation. We also define the air diffusion effectiveness which indicates the air flow pattern within specific rooms or sections of buildings. The results of measurements of these parameters in US office buildings by the authors and other researchers are reviewed. Almost all measurements indicate very limited short circuiting or displacement flow between locations of air supply and removal. However, a moderate degree of short circuiting is evident from a few measurements in rooms with heated supply air. The results of laboratory-based measurements by the authors are consistent with the field data. Our measurements in office buildings do indicate that ventilation rates can vary substantially between indoor locations, probably due to variation in air supply rates between locations rather than variation in the indoor air flow patterns. One possible method of improving air distribution is to employ task ventilation with air supplied closer to the occupant's breathing zone. We have evaluated two task ventilation systems in a laboratory setting. During most operating conditions, these systems did not provide a region of substantially increased ventilation where occupants breath. However, both systems are capable of providing substantially enhanced ventilation at the breathing zone under some operating conditions. Therefore, task ventilation is a potential option for using ventilation air more effectively.

  20. 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.

  1. Effect of Different Attentional Instructions on the Acquisition of a Serial Movement Task

    PubMed Central

    Woo, Mei Teng; Chow, Jia Yi; Koh, Michael

    2014-01-01

    Recent research in attentional focus of instruction has predominantly over-emphasized the investigation of discrete and continuous skills rather than serial skills. The purpose of this study was therefore to examine the effect of different attentional focus instructions on learning a serial skill task (i.e., taekwondo routine) in novice learners. It was predicted that the use of movement outcome instructions could enhance the learning of a serial skill as previously supported in studies examining the acquisition of discrete and continuous skills. Thirteen female participants were recruited for this study and were assigned to either movement form condition - control group (n = 7) or movement outcome condition – treatment group (n = 6). All participants underwent 12 practice sessions over an 8-week period with their respective instructional conditions with each session lasting 30 minutes. Video recording of the serial skill tasks (hand techniques, kicking techniques and 10-step routine) were captured at “the-twelfth-training session”, “after 1-week”, and “after 1-month”. It was found that more participants in the treatment group obtained a higher score in all three serial skill tasks, especially in Mastery component of ‘Kicking’ techniques at ‘after 1-week’ (p < 0.05, r = 0.57). This study suggested that movement outcome instructions have positive medium effect on balance control for serial skill task, especially in kicking actions. Key Points Movement outcome (MO) instructions have a positive impact on learning a serial task, especially in kicking actions. More functional coordination during movement executions for MO participants. Benefits for MO instructions may be individual specific. PMID:25435770

  2. 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…

  3. 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).…

  4. Adolescent Social Competence: Effectiveness in a Group Setting.

    ERIC Educational Resources Information Center

    Englund, Michelle M.; Levy, Alissa K.; Hyson, Daniel M.; Sroufe, L. Alan

    2000-01-01

    Examined the validity of an observational assessment of adolescent social competence within a group interaction during a revealed differences task. Found that ratings of task enjoyment, involvement, leadership, self-confidence in task, and global social competence showed strong correlations to counselor ratings and peer sociometrics and were…

  5. Effectiveness of Groups in the Schools

    ERIC Educational Resources Information Center

    Gerrity, Deborah A.; DeLucia-Waack, Janice L.

    2007-01-01

    This article reviews the current literature, specifically meta-analytic research, on the effectiveness of psychoeducational and counseling groups in the schools. Topics for such groups include: eating disorders, anger management/bullying, child sexual abuse prevention, pregnancy prevention, and social competency. There is support for groups in the…

  6. Effects of cues in a binary categorization task on dual-task performance, mental workload, and effort.

    PubMed

    Botzer, Assaf; Meyer, Joachim; Parmet, Yisrael

    2016-09-01

    Binary cues help operators perform binary categorization tasks, such as monitoring for system failures. They may also allow them to attend to other tasks they concurrently perform. If the time saved by using cues is allocated to other concurrent tasks, users' overall effort may remain unchanged. In 2 experiments, participants performed a simulated quality control task, together with a tracking task. In half the experimental blocks cues were available, and participants could use them in their decisions about the quality of products (intact or faulty). In Experiment 1, the difficulty of tracking was constant, while in Experiment 2, tracking difficulty differed in the 2 halves of the experiment. In both experiments, participants reported on the NASA Task Load Index that cues improved their performance and reduced their frustration. Consequently, their overall score on mental workload (MWL) was lower with cues. They also reported, however, that cues did not reduce their effort. We conclude that cues and other forms of automation may support task performance and reduce overall MWL, but this will not necessarily mean that users will work less hard. Thus, effort and overall MWL should be evaluated separately, if one wants to obtain a full picture of the effects of automation. (PsycINFO Database Record PMID:27505049

  7. 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…

  8. 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…

  9. The Effects of Study Tasks in a Computer-Based Chemistry Learning Environment

    ERIC Educational Resources Information Center

    Urhahne, Detlef; Nick, Sabine; Poepping, Anna Christin; Schulz , Sarah Jayne

    2013-01-01

    The present study examines the effects of different study tasks on the acquisition of knowledge about acids and bases in a computer-based learning environment. Three different task formats were selected to create three treatment conditions: learning with gap-fill and matching tasks, learning with multiple-choice tasks, and learning only from text…

  10. Effects of Different Degrees of Task Structure on Leadership in Couples.

    ERIC Educational Resources Information Center

    Rosmann, Michael R.; Mowbray, R. Glenn

    This study examined the effects of different degrees of task structure on leadership between 18 married parents, 18 childless married spouses, and 18 unmarried men and women who comprised newly acquainted couples. Each couple completed three tasks which varied along the dimension of task structure and the order of task presentation. Analysis of…

  11. The effectiveness of group-purchasing organizations.

    PubMed Central

    Cleverley, W O; Nutt, P C

    1984-01-01

    The prices paid for routine medical supply items by six hospital group-purchasing systems and a control group of 24 nonaffiliated hospitals were compared to determine the effects of group purchasing. Each of the six group-purchasing systems obtained lower prices for supply items used in the study, ranging from 12 to 26 percent average savings. The enforcement of written contracts among the plan's members and the percentage of plan member participation appeared to explain effectiveness. Size of the plan and volume of purchases did not influence the percentage of saving realized among the groups. PMID:6724956

  12. 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.

  13. Effect of task load and task load increment on performance and workload

    NASA Technical Reports Server (NTRS)

    Hancock, P. A.; Williams, G.

    1993-01-01

    The goal of adaptive automated task allocation is the 'seamless' transfer of work demand between human and machine. Clearly, at the present time, we are far from this objective. One of the barriers to achieving effortless human-machine symbiosis is an inadequate understanding of the way in which operators themselves seek to reallocate demand among their own personal 'resources.' The paper addresses this through an examination of workload response, which scales an individual's reaction to common levels of experienced external demand. The results indicate the primary driver of performance is the absolute level of task demand over the increment in that demand.

  14. [Effect of repetitive tasks on workers' sense of well-being in the watch industry].

    PubMed

    Oegerli, K

    1980-12-01

    In an interdisciplinary study, which was carried out in the Swiss watch industry, the influence of different job characteristics on the workers' well-being was investigated. Comparing the ergonomic, psychological and medical data of 120 women and 80 men executing tasks with restricted or enlarged degree of discretion, the following negative effects of repetitive tasks with low variety and little autonomy must be considered important: 1. pains in theeyes and headache 2. pains in the neck, the shoulder and the arms 3. increased intake of analgesics and sedatives 4. strongly experienced qualitative underload 5. a resignative tendency to accept small supplies for need fulfilment in the work situation. In both groups with a restricted degree of dicretion but also in the control group with more autonomy and variety a negative correlation could be found between length of service in job and the test score measuring information processing capacity. PMID:7245925

  15. Effects of handedness on olfactory event-related potentials in a simple olfactory task.

    PubMed

    Gottschlich, Marie; Hummel, Thomas

    2015-06-01

    The purpose of the present study was to re-investigate the influence of handedness on simple olfactory tasks to further clarify the role of handedness in chemical senses. Similar to language and other sensory systems, effects of handedness should be expected. Young, healthy subjects participated in this study, including 24 left-handers and 24 right-handers, with no indication of any major nasal or health problems. The two groups did not differ in terms of sex and age (14 women and 10 men in each group). They had a mean age of 24.0 years. Olfactory event-related potentials were recorded after left or right olfactory stimulation with the rose-like odor phenyl ethyl alcohol (PEA) or the smell of rotten eggs (hydrogen sulfide, H2S). Results suggested that handedness has no major influence on amplitude or latency of olfactory event-related potentials when it comes to simple olfactory tasks. PMID:26030037

  16. Learning one task by interleaving practice with another task

    PubMed Central

    Szpiro, Sarit; Wright, Beverly A.; Carrasco, Marisa

    2014-01-01

    Perceptual learning is a sustainable improvement in performance on a perceptual task following training. A hallmark of perceptual learning is task specificity – after participants have trained on and learned a particular task, learning rarely transfers to another task, even with identical stimuli. Accordingly, it is assumed that performing a task throughout training is a requirement for learning to occur on that specific task. Thus, interleaving training trials of a target task, with those of another task, should not improve performance on the target task. However, recent findings in audition show that interleaving two tasks during training can facilitate perceptual learning, even when the training on neither task yields learning on its own. Here we examined the role of cross-task training in the visual domain by training 4 groups of human observers for 3 consecutive days on an orientation comparison task (target task) and/or spatial-frequency comparison task (interleaving task). Interleaving small amounts of training on each task, which were ineffective alone, not only enabled learning on the target orientation task, as in audition, but also surpassed the learning attained by training on that task alone for the same total number of trials. This study illustrates that cross-task training in visual perceptual learning can be more effective than single-task training. The results reveal a comparable learning principle across modalities and demonstrate how to optimize training regimens to maximize perceptual learning. PMID:24959653

  17. Semantic interference in a randomized naming task: Effects of age, order, and category

    PubMed Central

    Gordon, Jean K.; Cheimariou, Spyridoula

    2014-01-01

    Lexical retrieval in production is a competitive process, requiring activation of a target word from semantic input, and its selection from amongst co-activated items. Competitors are automatically primed through spreading activation within the lexicon, but competition may be increased by the prior presentation of related items, the semantic interference effect. This has been demonstrated in tasks in which pictures grouped by semantic category are compared to unrelated pictures (blocked naming) and in tasks involving successive naming of items from the same semantic category (continuous naming). Such highly structured tasks may not be representative of the processes at work under more natural word retrieval conditions. Therefore, we conducted a retrospective examination of naming latencies from a randomized picture naming task containing a wide variety of items and categories. Our large sample of adults, ranging in age from 22 to 89 years, also allowed us to test the hypothesis that older adults, who are particularly susceptible to word-retrieval problems, experience increased difficulty resolving competition among lexical items. Semantic interference effects were evident in the interaction between semantic category and order of presentation within a block—miscellaneous items were named more quickly, whereas related items were named more slowly. This interference effect did not vary with participant age, contrary to the hypothesis that older adults are more susceptible to semantic interference. PMID:24499271

  18. 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…

  19. 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…

  20. When Is There Strength in Numbers? A Study of Undergraduate Task Groups

    ERIC Educational Resources Information Center

    Baker, Diane F.; Campbell, Connie M.

    2005-01-01

    Undergraduate college students in an advanced math class were videotaped as they worked on three mathematical proofs. Findings indicated that both ability and self-efficacy were needed for group success. Members with high levels of self-efficacy served the group by encouraging others to continue working. Groups tended to use a trial-and-error…

  1. EFFECTIVE INDICES FOR MONITORING MENTAL WORKLOAD WHILE PERFORMING MULTIPLE TASKS.

    PubMed

    Hsu, Bin-Wei; Wang, Mao-Jiun J; Chen, Chi-Yuan; Chen, Fang

    2015-08-01

    This study identified several physiological indices that can accurately monitor mental workload while participants performed multiple tasks with the strategy of maintaining stable performance and maximizing accuracy. Thirty male participants completed three 10-min. simulated multitasks: MATB (Multi-Attribute Task Battery) with three workload levels. Twenty-five commonly used mental workload measures were collected, including heart rate, 12 HRV (heart rate variability), 10 EEG (electroencephalography) indices (α, β, θ, α/θ, θ/β from O1-O2 and F4-C4), and two subjective measures. Analyses of index sensitivity showed that two EEG indices, θ and α/θ (F4-C4), one time-domain HRV-SDNN (standard deviation of inter-beat intervals), and four frequency-domain HRV: VLF (very low frequency), LF (low frequency), %HF (percentage of high frequency), and LF/HF were sensitive to differentiate high workload. EEG α/θ (F4-C4) and LF/HF were most effective for monitoring high mental workload. LF/HF showed the highest correlations with other physiological indices. EEG α/θ (F4-C4) showed strong correlations with subjective measures across different mental workload levels. Operation strategy would affect the sensitivity of EEG α (F4-C4) and HF. PMID:26226284

  2. Effect of caffeine on performances of a perceptual-restructuring task at different stages of practice.

    PubMed

    Broverman, D M; Casagrande, E

    1982-01-01

    Caffeine, a sympathomimetic drug which stimulates the adrenergic nervous system, was hypothesized to exert opposite effects upon performances of a perceptual-restructuring task (the Embedded Figures Task) at different stages of practice. Specifically, caffeine was hypothesized to impair performances of perceptual-restructuring tasks when the task is still novel in early trials; and to facilitate practice induced gains in task performance as the task becomes less novel. Sixty male undergraduates were studied. Each subject was tested on the Embedded Figures Task twice, in one of the following three sequences: caffeine-placebo; placebo-caffeine; and placebo-placebo. Both hypotheses received statistically significant support. PMID:6818581

  3. Valence, arousal, and task effects in emotional prosody processing

    PubMed Central

    Paulmann, Silke; Bleichner, Martin; Kotz, Sonja A.

    2013-01-01

    Previous research suggests that emotional prosody processing is a highly rapid and complex process. In particular, it has been shown that different basic emotions can be differentiated in an early event-related brain potential (ERP) component, the P200. Often, the P200 is followed by later long lasting ERPs such as the late positive complex. The current experiment set out to explore in how far emotionality and arousal can modulate these previously reported ERP components. In addition, we also investigated the influence of task demands (implicit vs. explicit evaluation of stimuli). Participants listened to pseudo-sentences (sentences with no lexical content) spoken in six different emotions or in a neutral tone of voice while they either rated the arousal level of the speaker or their own arousal level. Results confirm that different emotional intonations can first be differentiated in the P200 component, reflecting a first emotional encoding of the stimulus possibly including a valence tagging process. A marginal significant arousal effect was also found in this time-window with high arousing stimuli eliciting a stronger P200 than low arousing stimuli. The P200 component was followed by a long lasting positive ERP between 400 and 750 ms. In this late time-window, both emotion and arousal effects were found. No effects of task were observed in either time-window. Taken together, results suggest that emotion relevant details are robustly decoded during early processing and late processing stages while arousal information is only reliably taken into consideration at a later stage of processing. PMID:23801973

  4. 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

  5. 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.

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

    PubMed

    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

  7. 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

  8. 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…

  9. 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…

  10. Frequency Effects in Spoken and Visual Word Recognition: Evidence from Dual-Task Methodologies

    ERIC Educational Resources Information Center

    Cleland, Alexandra A.; Gaskell, M. Gareth; Quinlan, Philip T.; Tamminen, Jakke

    2006-01-01

    The authors report 3 dual-task experiments concerning the locus of frequency effects in word recognition. In all experiments, Task 1 entailed a simple perceptual choice and Task 2 involved lexical decision. In Experiment 1, an underadditive effect of word frequency arose for spoken words. Experiment 2 also showed underadditivity for visual lexical…

  11. 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…

  12. 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. PMID:9800687

  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. [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. PMID:6622911

  15. 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.…

  16. Effects of Morphine on Behavioral Task Performance in SIV-Infected Rhesus Macaques.

    PubMed

    Marcario, Joanne K; Pendyala, Gurudutt; Riazi, Mariam; Fleming, Kandace; Marquis, Janet; Callen, Shannon; Lisco, Steven J; Fowler, Stephen C; Cheney, Paul D; Buch, Shilpa J

    2016-06-01

    The abuse of opiates such as morphine in synergy with HIV infection not only exacerbates neuropathogenesis but significantly impacts behavioral attributes in HIV infected subjects. Thus, the goal of the current study was to characterize behavioral perturbations in rhesus macaques subjected to chronic morphine and SIV infection. Specifically, we assessed three behavioral tasks: motor skill (MS), forelimb force (FFT) and progressive ratio (PR) tasks. After collecting baseline control data (44 weeks) and data during the morphine-only dependency period (26 weeks), a subset of animals were productively infected with neurovirulent strains of SIVmac (R71/E17) for an additional 33 weeks. A general pattern in the results is that behavioral decline occurred with high CSF viral loads but not necessarily with high plasma viral loads. Compared to saline controls, all treated animals showed significant decreases in performance on all three behavioral tasks during the morphine-only dependency period. During the post infection period, only the morphine plus SIV group showed a significant further decline and this only occurred for the MS task. Taken together, these data demonstrate a clear effect of morphine to produce behavioral deficits and also suggest that morphine can act synergistically with SIV/HIV to exacerbate behavioral deficits. PMID:27039332

  17. Separation of Scaptotrigona postica workers into defined task groups by the chemical profile on their epicuticle wax layer.

    PubMed

    Poiani, Silvana B; Morgan, E David; Drijfhout, Falko P; da Cruz-Landim, Carminda

    2014-04-01

    During evolution, the cuticle surface of insects acquired functions in communication, such as inter- and intra-specific recognition, identification of gender, physiological state, and fertility. In eusocial bees, the information in the cuticular surface is important not only to discriminate nestmates from non-nestmates but also to identify an individual's class, life phase or task. A comparative study of the cuticular surface chemical profile of workers of Scaptotrigona postica in different phases of life, i.e., newly emerged workers (NE), brood comb area workers (CA), and forager workers (FO) was undertaken by gas chromatography linked to mass spectrometry. Multivariate statistical analysis was performed to verify how workers are grouped according to their chemical profile and to determine which compounds are responsible for separating them into groups. The cuticle surface of workers contains mainly hydrocarbons and a small amount of oxygenated compounds. Multivariate statistical analysis showed qualitative and quantitative variation in relation to the life phases/tasks performed, and all groups were distinct. The most abundant compound found in NE and CA was n-heptacosane, while in FO, it was (Z)-9-heptacosene. The compounds that differentiate NE from other groups are n-tricosane and n-hexacosane. A (Z)-X-octacosene and n-nonacosane are the chemicals that distinguish CA from NE and FO, while 11- and 13-methylpentacosane, (Z)-X-hexacosene, and (Z)-9-heptacosene characterize FO as distinct from NE and CA. The probable function of alkenes is nestmate recognition, mainly in FO. The results show that the cuticle surfaces of workers are characteristic of the phase of life/task performed by workers, allowing intra-colonial recognition. PMID:24752855

  18. Perceiving and acting upon spaces in a VR rugby task: expertise effects in affordance detection and task achievement.

    PubMed

    Correia, Vanda; Araújo, Duarte; Cummins, Alan; Craig, Cathy M

    2012-06-01

    This study used a virtual, simulated 3 vs. 3 rugby task to investigate whether gaps opening in particular running channels promote different actions by the ball carrier player and whether an effect of rugby expertise is verified. We manipulated emergent gaps in three different locations: Gap 1 in the participant's own running channel, Gap 2 in the first receiver's running channel, and Gap 3 in the second receiver's running channel. Recreational, intermediate, professional, and nonrugby players performed the task. They could (i) run with the ball, (ii) make a short pass, or (iii) make a long pass. All actions were digitally recorded. Results revealed that the emergence of gaps in the defensive line with respect to the participant's own position significantly influenced action selection. Namely, "run" was most often the action performed in Gap 1, "short pass" in Gap 2, and "long pass" in Gap 3 trials. Furthermore, a strong positive relationship between expertise and task achievement was found. PMID:22691396

  19. Preschoolers Effectively Tutor Novice Classmates in a Block Construction Task.

    ERIC Educational Resources Information Center

    Johnson-Pynn, Julie S.; Nisbet, Valerie S.

    2002-01-01

    Examined whether preschool-age experts (with task experience) would spontaneously assist novices (without task experience) when working in pairs on constructing a house with blocks. Found that experts were more likely to provide nonverbal assistance than verbal assistance, with modeling how to combine blocks being most frequent. The most frequent…

  20. Effects of Task Difficulty on Sibling Teaching in Middle Childhood

    ERIC Educational Resources Information Center

    Howe, Nina; Brody, Marie-Helene; Recchia, Holly

    2006-01-01

    Teaching styles were investigated in 28 middle-class sibling dyads (older sibling M age = 8.2 yrs; younger sibling M age = 5.11 yrs) using two sets of block design tasks (five easy; five hard). Older siblings employed a greater number of strategies (i.e. physical demonstrations, scaffolding, corrective feedback) in the hard than in the easy tasks,…

  1. The Effect of Orthographic Neighborhood in the Reading Span Task

    ERIC Educational Resources Information Center

    Robert, Christelle; Postal, Virginie; Mathey, Stéphanie

    2015-01-01

    This study aimed at examining whether and to what extent orthographic neighborhood of words influences performance in a working memory span task. Twenty-five participants performed a reading span task in which final words to be memorized had either no higher frequency orthographic neighbor or at least one. In both neighborhood conditions, each…

  2. 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.

  3. 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…

  4. Evidence for Task Conflict in the Stroop Effect

    ERIC Educational Resources Information Center

    Goldfarb, Liat; Henik, Avishai

    2007-01-01

    C. M. MacLeod and P. A. MacDonald (2000) suggested that congruent and incongruent Stroop stimuli cause more task conflict than neutral stimuli because the anterior cingulate cortex is more activated with these stimuli. This study investigated behavioral expression for this pattern. Experiment 1 reduced task conflict control by increasing the…

  5. 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. PMID:22941357

  6. Motivational orientations and task autonomy fit: effects on organizational attraction.

    PubMed

    Wu, Yu-Chi

    2012-02-01

    The main purpose of this study was to investigate whether there is congruence between applicant needs (i.e., motivational orientations) and what is available (i.e., task autonomy) from an organizational perspective based on the fit between needs and supply. The fit between work motivation and task autonomy was examined to see whether it was associated with organizational attraction. This experimental study included two phases. Phase 1 participants consisted of 446 undergraduate students, of whom 228 were recruited to participate in Phase 2. The fit relations between task autonomy and intrinsic motivation and between task control and extrinsic motivation were characterized. Findings indicated that the fit between work motivation and task autonomy was positively associated with organizational attraction. Based on these results, it may be inferred that employers should emphasize job characteristics such as autonomy or control orientations to attract individuals, and focus on the most suitable work motivations for their organizations. PMID:22582692

  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. 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…

  9. 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.

  10. 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…

  11. 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…

  12. The effect of muscle fatigue on position sense in an upper limb multi-joint task.

    PubMed

    Vafadar, Amirhossein K; Côté, Julie N; Archambault, Philippe S

    2012-04-01

    The purpose of this study was to estimate the extent to which muscle fatigue can impact on the position sense in the upper limb. Twelve healthy volunteers were asked to do a reaching task while grasping a wooden block and match the block's position with a corresponding target displayed on a flat screen, without vision. Following that, subjects performed resistive exercises with Thera-band strips until fatigue was induced and then the position sense task was repeated. A significant change in the endpoint position was observed after fatigue, in the up/down direction (p ≤ .001). The variability of endpoint positions in up/down direction was also significantly increased after fatigue (p ≤.03). There was no significant change in endpoint orientation but there was a significant fatigue × orientation effect on endpoint rotational variability. In a follow-up experiment, a group of subjects repeated the same protocol, but with a period of quiet rest between the two position sense tasks. In that group, there were no differences in endpoint position, orientation or variability. Muscle fatigue is an important factor that should be taken into consideration during the treatment of musculoskeletal injuries as well as athletic training. PMID:22357216

  13. Effects of aging on task- and stimulus-related cerebral attention networks.

    PubMed

    Kurth, Sophie; Majerus, Steve; Bastin, Christine; Collette, Fabienne; Jaspar, Mathieu; Bahri, Mohamed Ali; Salmon, Eric

    2016-08-01

    Interactions between a dorsal attention network (DAN) and a ventral attention cerebral network (VAN) have been reported in young participants during attention or short-term memory (STM) tasks. Because it remains an underinvestigated question, age effects on DAN and VAN activity and their functional balance were explored during performance of an STM task. Older and younger groups showed similar behavioral patterns of results. At the cerebral level, DAN activation increased as a function of increasing STM load in both groups, suggesting preserved activity in DAN during healthy aging. Age-related over-recruitment in regions of the DAN in the higher task load raised the question of compensation attempt versus less efficient use of neural resources in older adults. Lesser decrease of VAN activation with increasing load and decreased stimulus-driven activation in the VAN, especially in the higher load, in older participants suggested age-related reduced response in the VAN. However, functional connectivity measures showed that VAN was still functionally connected to the DAN in older participants. PMID:27318136

  14. 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. PMID:23458884

  15. 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

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

    PubMed

    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

  17. The Effects of Differential Goal Weights on the Performance of a Complex Financial Task.

    ERIC Educational Resources Information Center

    Edmister, Robert O.; Locke, Edwin A.

    1987-01-01

    Determined whether people could obtain outcomes on a complex task that would be in line with differential goal weights corresponding to different aspects of the task. Bank lending officers were run through lender-simulation exercises. Five performance goals were weighted. Demonstrated effectiveness of goal setting with complex tasks, using group…

  18. 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…

  19. Prospective Memory in Children: The Effects of Age and Task Interruption.

    ERIC Educational Resources Information Center

    Kvavilashvili, Lia; Messer, David J.; Ebdon, Pippa

    2001-01-01

    Three experiments examined effects of age and task interruption on children's prospective memory (PM), remembering to carry out a future task. Age explained a small portion of variance in performance. Children who did not have to interrupt their ongoing activity to complete the PM tasks performed significantly better than children who had to…

  20. 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

  1. 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. PMID:27199875

  2. 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.

  3. The significance of task significance: Job performance effects, relational mechanisms, and boundary conditions.

    PubMed

    Grant, Adam M

    2008-01-01

    Does task significance increase job performance? Correlational designs and confounded manipulations have prevented researchers from assessing the causal impact of task significance on job performance. To address this gap, 3 field experiments examined the performance effects, relational mechanisms, and boundary conditions of task significance. In Experiment 1, fundraising callers who received a task significance intervention increased their levels of job performance relative to callers in 2 other conditions and to their own prior performance. In Experiment 2, task significance increased the job dedication and helping behavior of lifeguards, and these effects were mediated by increases in perceptions of social impact and social worth. In Experiment 3, conscientiousness and prosocial values moderated the effects of task significance on the performance of new fundraising callers. The results provide fresh insights into the effects, relational mechanisms, and boundary conditions of task significance, offering noteworthy implications for theory, research, and practice on job design, social information processing, and work motivation and performance. PMID:18211139

  4. Congruency sequence effect in cross-task context: evidence for dimension-specific modulation.

    PubMed

    Lee, Jaeyong; Cho, Yang Seok

    2013-11-01

    The congruency sequence effect refers to a reduced congruency effect after incongruent trials relative to congruent trials. This modulation is thought to be, at least in part, due to the control mechanisms resolving conflict. The present study examined the nature of the control mechanisms by having participants perform two different tasks in an alternating way. When participants performed horizontal and vertical Simon tasks in Experiment 1A, and horizontal and vertical spatial Stroop task in Experiment 1B, no congruency sequence effect was obtained between the task congruencies. When the Simon task and spatial Stroop task were performed with different response sets in Experiment 2, no congruency sequence effect was obtained. However, in Experiment 3, in which the participants performed the horizontal Simon and spatial Stroop tasks with an identical response set, a significant congruency sequence effect was obtained between the task congruencies. In Experiment 4, no congruency sequence effect was obtained when participants performed two tasks having different task-irrelevant dimensions with the identical response set. The findings suggest inhibitory processing between the task-irrelevant dimension and response mode after conflict. PMID:24184348

  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. 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.

  7. The effects of functional limitations on soldier common tasks.

    PubMed

    Bacon, John R; Armstrong, Thomas J; Brininger, Teresa L

    2012-01-01

    This paper describes the findings associated with the ability of an individual to perform the United States Army's Common Soldier Tasks of: "Maintaining an M16-Series Rifle" , "Protect Yourself from Chemical, Biological, Radiological, and Nuclear (CBRN) Injury or Contamination with Mission-Oriented Protective Posture (MOPP) Gear", and "Protect Yourself from Chemical and Biological (CB) Contamination Using Your Assigned Protective Mask." The analysis was conducted using data compiled from videos of a Soldier performing the given tasks at Walter Reed Army Medical Center. The findings reflect the opinions of researchers in identifying potential elements, which impose abnormal, irregular, and/or extraneous effort when performing the tasks as outlined in STP-21-1-SMCT - Soldier's Manual of Common Tasks: Skill Level I. PMID:22316761

  8. Effects of a Target-Task Problem-Solving Model on Senior Secondary School Students' Performance in Physics

    ERIC Educational Resources Information Center

    Olaniyan, A. O.; Omosewo, E. O.

    2015-01-01

    The study investigated the Effects of a Target-Task Problem-Solving Model on Senior Secondary School Students' Performance in Physics. The research design was a quasi-experimental, non-randomized, non-equivalent pretest, post-test using a control group. The study was conducted in two schools purposively selected and involved a total of 120 Senior…

  9. 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…

  10. 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…

  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. 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…

  13. 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

  14. 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…

  15. 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

  16. 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. PMID:26555341

  17. The effects of dual tasking on handwriting in patients with Parkinson's disease.

    PubMed

    Broeder, S; Nackaerts, E; Nieuwboer, A; Smits-Engelsman, B C M; Swinnen, S P; Heremans, E

    2014-03-28

    Previous studies have shown that patients with Parkinson's disease (PD) experience extensive problems during dual tasking. Up to now, dual-task interference in PD has mainly been investigated in the context of gait research. However, the simultaneous performance of two different tasks is also a prerequisite to efficiently perform many other tasks in daily life, including upper limb tasks. To address this issue, this study investigated the effect of a secondary cognitive task on the performance of handwriting in patients with PD. Eighteen PD patients and 11 age-matched controls performed a writing task involving the production of repetitive loops under single- and dual-task conditions. The secondary task consisted of counting high and low tones during writing. The writing tests were performed with two amplitudes (0.6 and 1.0cm) using a writing tablet. Results showed that dual-task performance was affected in PD patients versus controls. Dual tasking reduced writing amplitude in PD patients, but not in healthy controls (p=0.046). Patients' writing size was mainly reduced during the small-amplitude condition (small amplitude p=0.017; large amplitude p=0.310). This suggests that the control of writing at small amplitudes requires more compensational brain-processing recourses in PD and is as such less automatic than writing at large amplitudes. In addition, there was a larger dual-task effect on the secondary task in PD patients than controls (p=0.025). The writing tests on the writing tablet proved highly correlated to daily life writing as measured by the 'Systematic Screening of Handwriting Difficulties' test (SOS-test) and other manual dexterity tasks, particularly during dual-task conditions. Taken together, these results provide additional insights into the motor control of handwriting and the effects of dual tasking during upper limb movements in patients with PD. PMID:24447597

  18. PRP training shows Task1 response selection is the locus of the backward response compatibility effect.

    PubMed

    Thomson, Sandra J; Danis, Lila K; Watter, Scott

    2015-02-01

    The present study investigates the effect of practice in a psychological refractory period (PRP) paradigm on the backward compatibility effect (BCE), in order to determine the locus of this response priming effect on Task1 performance. In two experiments, we show that the size of the BCE is closely associated with the duration of the response selection stage in Task1. When this stage is shortened through PRP practice, the magnitude of the BCE decreases. Subsequently increasing the duration of Task1 response selection results in a larger BCE, but manipulating the same stage in Task2 does not. Our results suggest that the BCE reflects crosstalk of unattended response information for Task2 acting on the response selection stage in Task1, and that response information for two tasks may be activated simultaneously. PMID:24845877

  19. Task switching in a hierarchical task structure: evidence for the fragility of the task repetition benefit

    NASA Technical Reports Server (NTRS)

    Lien, Mei-Ching; Ruthruff, Eric

    2004-01-01

    This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms. In Experiments 2-5, adjacent task elements were grouped temporally and/or spatially (forming an ensemble) to create a hierarchical task organization. Results indicate that the effect of switching at the ensemble level dominated the effect of switching at the element level. Experiments 6 and 7, using an ensemble of 3 task elements, revealed that the element-level switch cost was virtually absent between ensembles but was large within an ensemble. The authors conclude that the element-level task repetition benefit is fragile and can be eliminated in a hierarchical task organization.

  20. 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. PMID:26886505

  1. 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.

  2. Implications of the ICRP Task Group's proposed lung model for internal dose assessments in the mineral sands industry

    SciTech Connect

    James, A.C. ); Birchall, A. )

    1990-09-01

    The ICRP Task Group on Respiratory Tract Models for Radiological Projection is proposing a model to describe the deposition, clearance, retention and dosimetry of inhaled radionuclides for dose-intake calculations and interpretation of bioassay data. The deposition model takes into account new data on the regional deposition of aerosol particles in human lung and the inhalability of large particles. The clearance model treats clearance as competition between mechanical transport, which moves particles to the gastro-intestinal tract and lymph nodes, and the translocation of material to blood. This provides a realistic estimate of the amount of a given material (such as mineral sand) that is absorbed systemically, and its variation with aerosol size. The proposed dosimetry model takes into account the relative sensitivities of the various tissue components of the respiratory tract. A new treatment of dose received by epithelia in the tracheo-bronchiolar and extrathoracic regions is proposed. This paper outlines the novel features of the task group model, and then examines the impact that adoption of the model may have on the assessment of doses from occupational exposures to mineral sands and thoron progeny. 39 refs., 15 figs., 6 tabs.

  3. 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. PMID:16752582

  4. 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.

  5. The Effect of "Massed" Task Repetitions on Complexity, Accuracy and Fluency: Does It Transfer to a New Task?

    ERIC Educational Resources Information Center

    Ahmadian, Mohammad Javad

    2011-01-01

    To date, research results suggest that task repetition positively affects oral task performance. However, researchers have not yet shown the extension of the benefits of repeating the same task to performance of a new task. This article first provides an overview of the currently available research findings on task repetition and then presents the…

  6. 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…

  7. 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…

  8. 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…

  9. Differential effects of bupropion on acquisition and performance of an active avoidance task in male mice.

    PubMed

    Gómez, M C; Redolat, R; Carrasco, M C

    2016-03-01

    Bupropion is an antidepressant drug that is known to aid smoking cessation, although little experimental evidence exists about its actions on active avoidance learning tasks. Our aim was to evaluate the effects of this drug on two-way active avoidance conditioning. In this study, NMRI mice received bupropion (10, 20 and 40mg/kg) or saline before a daily training session (learning phase, days 1-4) in the active avoidance task. Performance was evaluated on the fifth day (retention phase): in each bupropion-treated group half of the mice continued with the same dose of bupropion, and the other half received saline. Among the vehicle-treated mice, different sub-groups were challenged with different doses of bupropion. Results indicated that mice treated with 10 and 20mg/kg bupropion exhibited more number of avoidances during acquisition. The response latency confirmed this learning improvement, since this parameter decreased after bupropion administration. No differences between groups were observed in the retention phase. In conclusion, our data show that bupropion influences the learning process during active avoidance conditioning, suggesting that this drug can improve the control of emotional responses. PMID:26688488

  10. 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.

  11. 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.

  12. Frequency and regularity effects in reading are task dependent: Evidence from ERPs

    PubMed Central

    Fischer-Baum, Simon; Dickson, Danielle S.; Federmeier, Kara D.

    2014-01-01

    Many theories of visual word processing assume obligatory semantic access and phonological recoding whenever a written word is encountered. However, the relative importance of different reading processes depends on task. The current study uses event related potentials (ERPs) to investigate whether – and, if so, when and how – effects of task modulate how visually-presented words are processed. Participants were presented written words in the context of two tasks, delayed reading aloud and proper name detection. Stimuli varied factorially on lexical frequency and on spellingto-sound regularity, while controlling for other lexical variables. Effects of both lexical frequency and regularity were modulated by task. Lexical frequency modulated N400 amplitude, but only in the reading aloud task, whereas spellingto-sound regularity interacted with frequency to modulate the LPC, again only in the reading aloud task. Taken together, these results demonstrate that task demands affect how meaning and sound are generated from written words. PMID:25436218

  13. Effectiveness of the Gaze Direction Recognition Task for Chronic Neck Pain and Cervical Range of Motion: A Randomized Controlled Pilot Study

    PubMed Central

    Nobusako, Satoshi; Matsuo, Atsushi; Morioka, Shu

    2012-01-01

    We developed a mental task with gaze direction recognition (GDR) by which subjects observed neck rotation of another individual from behind and attempted to recognize the direction of gaze. A randomized controlled trial was performed in test (n = 9) and control (n = 8) groups of subjects with chronic neck pain undergoing physical therapy either with or without the GDR task carried out over 12 sessions during a three-week period. Primary outcome measures were defined as the active range of motion and pain on rotation of the neck. Secondary outcome measures were reaction time (RT) and response accuracy in the GDR task group. ANOVA indicated a main effect for task session and group, and interaction of session. Post hoc testing showed that the GDR task group exhibited a significant simple main effect upon session, and significant sequential improvement of neck motion and relief of neck pain. Rapid effectiveness was significant in both groups. The GDR task group had a significant session-to-session reduction of RTs in correct responses. In conclusion, the GDR task we developed provides a promising rehabilitation measure for chronic neck pain. PMID:22645685

  14. 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. PMID:24406438

  15. 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

  16. A Closer Look at the Thresholds of Thermal Damage: Workshop Report by an ICNIRP Task Group.

    PubMed

    Sienkiewicz, Zenon; van Rongen, Eric; Croft, Rodney; Ziegelberger, Gunde; Veyret, Bernard

    2016-09-01

    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

  17. Effects of Methylphenidate on performance of a practical pistol shooting task: a quantitative electroencephalography (qEEG) study

    PubMed Central

    2011-01-01

    Background The present study examined absolute alpha power using quantitative electroencephalogram (qEEG) in bilateral temporal and parietal cortices in novice soldiers under the influence of methylphenidate (MPH) during the preparatory aiming period in a practical pistol-shooting task. We anticipated higher bi-hemispheric cortical activation in the preparatory period relative to pre-shot baseline in the methylphenidate group when compared with the control group because methylphenidate has been shown to enhance task-related cognitive functions. Methods Twenty healthy, novice soldiers were equally distributed in control (CG; n = 10) and MPH groups 10 mg (MG; n = 10) using a randomized, double blind design. Subjects performed a pistol-shooting task while electroencephalographic activity was acquired. Results We found main effects for group and practice blocks on behavioral measures, and interactions between group and phases on electroencephalographic measures for the electrodes T3, T4, P3 and P4. Regarding the behavioral measures, the MPH group demonstrated significantly poorer in shooting performance when compared with the control and, in addition, significant increases in the scores over practice blocks were found on both groups. In addition, regarding the electroencephalographic data, we observed a significant increase in alpha power over practice blocks, but alpha power was significantly lower for the MPH group when compared with the placebo group. Moreover, we observed a significant decrease in alpha power in electrodes T4 and P4 during PTM. Conclusion Although we found no correlation between behavioral and EEG data, our findings show that MPH did not prevent the learning of the task in healthy subjects. However, during the practice blocks (PBs) it also did not favor the performance when compared with control group performance. It seems that the CNS effects of MPH demanded an initial readjustment period of integrated operations relative to the sensorimotor

  18. 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.

  19. 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.

  20. Fine and gross motor skills: The effects on skill-focused dual-tasks.

    PubMed

    Raisbeck, Louisa D; Diekfuss, Jed A

    2015-10-01

    Dual-task methodology often directs participants' attention towards a gross motor skill involved in the execution of a skill, but researchers have not investigated the comparative effects of attention on fine motor skill tasks. Furthermore, there is limited information about participants' subjective perception of workload with respect to task performance. To examine this, the current study administered the NASA-Task Load Index following a simulated shooting dual-task. The task required participants to stand 15 feet from a projector screen which depicted virtual targets and fire a modified Glock 17 handgun equipped with an infrared laser. Participants performed the primary shooting task alone (control), or were also instructed to focus their attention on a gross motor skill relevant to task execution (gross skill-focused) and a fine motor skill relevant to task execution (fine skill-focused). Results revealed that workload was significantly greater during the fine skill-focused task for both skill levels, but performance was only affected for the lesser-skilled participants. Shooting performance for the lesser-skilled participants was greater during the gross skill-focused condition compared to the fine skill-focused condition. Correlational analyses also demonstrated a significant negative relationship between shooting performance and workload during the gross skill-focused task for the higher-skilled participants. A discussion of the relationship between skill type, workload, skill level, and performance in dual-task paradigms is presented. PMID:26296039

  1. 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.

  2. Task effects on BOLD signal correlates of implicit syntactic processing.

    PubMed

    Caplan, David

    2010-07-01

    BOLD signal was measured in sixteen participants who made timed font change detection judgments in visually presented sentences that varied in syntactic structure and the order of animate and inanimate nouns. Behavioral data indicated that sentences were processed to the level of syntactic structure. BOLD signal increased in visual association areas bilaterally and left supramarginal gyrus in the contrast of sentences with object- and subject-extracted relative clauses without font changes in which the animacy order of the nouns biased against the syntactically determined meaning of the sentence. This result differs from the findings in a non-word detection task (Caplan et al, 2008a), in which the same contrast led to increased BOLD signal in the left inferior frontal gyrus. The difference in areas of activation indicates that the sentences were processed differently in the two tasks. These differences were further explored in an eye tracking study using the materials in the two tasks. Issues pertaining to how parsing and interpretive operations are affected by a task that is being performed, and how this might affect BOLD signal correlates of syntactic contrasts, are discussed. PMID:20671983

  3. The Effects of Tasks on Integrating Information from Multiple Documents

    ERIC Educational Resources Information Center

    Cerdan, Raquel; Vidal-Abarca, Eduardo

    2008-01-01

    The authors examine 2 issues: (a) how students integrate information from multiple scientific documents to describe and explain a physical phenomenon that represents a subset of the information in the documents; and (b) the role of 2 sorts of tasks to achieve this type of integration, either writing an essay on a question requiring integration…

  4. Task effects on BOLD signal correlates of implicit syntactic processing

    PubMed Central

    Caplan, David

    2010-01-01

    BOLD signal was measured in sixteen participants who made timed font change detection judgments in visually presented sentences that varied in syntactic structure and the order of animate and inanimate nouns. Behavioral data indicated that sentences were processed to the level of syntactic structure. BOLD signal increased in visual association areas bilaterally and left supramarginal gyrus in the contrast of sentences with object- and subject-extracted relative clauses without font changes in which the animacy order of the nouns biased against the syntactically determined meaning of the sentence. This result differs from the findings in a non-word detection task (Caplan et al, 2008a), in which the same contrast led to increased BOLD signal in the left inferior frontal gyrus. The difference in areas of activation indicates that the sentences were processed differently in the two tasks. These differences were further explored in an eye tracking study using the materials in the two tasks. Issues pertaining to how parsing and interpretive operations are affected by a task that is being performed, and how this might affect BOLD signal correlates of syntactic contrasts, are discussed. PMID:20671983

  5. 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:…

  6. 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…

  7. 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…

  8. 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…

  9. AAPM Task Group 108: PET and PET/CT Shielding Requirements

    SciTech Connect

    Madsen, Mark T.; Anderson, Jon A.; Halama, James R.

    2006-01-15

    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.

  10. 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. PMID:16485403

  11. Use of a Tracing Task to Assess Visuomotor Performance: Effects of Age, Sex, and Handedness

    PubMed Central

    2013-01-01

    Background. Visuomotor abnormalities are common in aging and age-related disease, yet difficult to quantify. This study investigated the effects of healthy aging, sex, and handedness on the performance of a tracing task. Participants (n = 150, aged 21–95 years, 75 females) used a stylus to follow a moving target around a circle on a tablet computer with their dominant and nondominant hands. Participants also performed the Trail Making Test (a measure of executive function). Methods. Deviations from the circular path were computed to derive an “error” time series. For each time series, absolute mean, variance, and complexity index (a proposed measure of system functionality and adaptability) were calculated. Using the moving target and stylus coordinates, the percentage of task time within the target region and the cumulative micropause duration (a measure of motion continuity) were computed. Results. All measures showed significant effects of aging (p < .0005). Post hoc age group comparisons showed that with increasing age, the absolute mean and variance of the error increased, complexity index decreased, percentage of time within the target region decreased, and cumulative micropause duration increased. Only complexity index showed a significant difference between dominant versus nondominant hands within each age group (p < .0005). All measures showed relationships to the Trail Making Test (p < .05). Conclusions. Measures derived from a tracing task identified performance differences in healthy individuals as a function of age, sex, and handedness. Studies in populations with specific neuromotor syndromes are warranted to test the utility of measures based on the dynamics of tracking a target as a clinical assessment tool. PMID:23388876

  12. 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. PMID:26135908

  13. The effects of alcohol expectancy priming on group bonding.

    PubMed

    Moltisanti, Allison J; Below, Maureen C; Brandon, Karen O; Goldman, Mark S

    2013-12-01

    According to alcohol expectancy theory, drinking-related information is stored in memory and, when cue activated, influences alcohol-related behavior. Priming of alcohol cues and expectancies has been shown to elicit both drinking and nonconsumptive behavior associated with alcohol consumption, such as willingness to meet with a stranger and aggression. These social influence effects have been shown to be moderated by individual differences in alcohol expectancies. In the present study, we tested whether an alcohol prime would facilitate social group bonding even in the absence of consumption, and whether such group bonding would be moderated by individually held social expectancies. One hundred twenty undergraduates (75% female) completed an alcohol expectancy measure prior to participation. Participants were primed with either alcohol or neutral beverage words and completed a collaborative group activity followed by questionnaires measuring perceived group cohesion. Several interactions were found between condition and expectancy reflecting that those in the alcohol prime condition with higher social alcohol expectancies reported greater cohesion on task-related, but not emotion-related, group measures. These findings underscore the complexity of the impact of expectancy and social behavior on drinking: the priming of alcohol expectancies may activate aspects of pro-social behavior, which may influence drinking, which in turn may feedback to positively reinforce social expectancies. PMID:24128149

  14. Automated Calculation of Water-equivalent Diameter (DW) Based on AAPM Task Group 220.

    PubMed

    Anam, Choirul; Haryanto, Freddy; Widita, Rena; Arif, Idam; Dougherty, Geoff

    2016-01-01

    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. PMID:27455491

  15. 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

  16. The Effects of Self-Instructional Training on Job-Task Sequencing: Suggesting a Problem-Solving Strategy.

    ERIC Educational Resources Information Center

    Agran, Martin; And Others

    1986-01-01

    The study examined effects of a self-instructional training package on the job-task sequencing, task completion, and unnecessary task repetition of four mentally retarded females (ages 18-20) employed as housekeeping and food service trainees in a hospital. Among results were increased job-task sequencing and decreased task repetition for all…

  17. Effects of craniocervical flexion exercise on upper-limb postural stability during a goal-directed pointing task

    PubMed Central

    Yong, Min-Sik; Lee, Hae-Yong; Ryu, Young-Uk; Lee, Mi-Young

    2015-01-01

    [Purpose] This study investigated the effects of craniocervical flexion exercise on upper-limb postural stability by measuring upper-limb postural tremor during a goal-directed pointing task. [Subjects and Methods] Twenty-four subjects were randomly assigned to the exercise or control group. The exercise group performed craniocervical flexion exercise four days per week for five weeks. Upper-limb postural tremor was measured by using a three-dimensional electromagnetic motion tracking system (trakSTAR™, Ascension Technology Corporation, Burlington, VT, USA) during a goal-directed pointing task. [Results] In the exercise group, the range and velocity of the trajectories of the shoulder, wrist, and finger in the lateral direction improved significantly. However, no significant changes were observed in the control group. [Conclusion] Craniocervical flexion exercise reduces the range and velocity of upper-limb postural tremor, thereby increasing postural stability. PMID:26180368

  18. 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

  19. 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.

  20. Joint Effects of Group Composition, Group Norm, Type of Problem and Group vs. Individual Responding.

    ERIC Educational Resources Information Center

    Egerbladh, Thor; Sjodin, Sture

    1986-01-01

    Potential interactions between four factors of educational interest within small group research were studied: (1) type of problem; (2) group composition; (3) group norm; and (4) group productivity. Reliable interactions were obtained for: (1) sex x group norm; (2) sex x group norm x productivity; and (3) type of problem x productivity. (Author/LMO)

  1. Pyridinium-based Task-specific Ionic Liquid with a Monothioether Group for Selective Extraction of Class b Metal Ions.

    PubMed

    Chayama, Kenji; Sano, Yuki; Iwatsuki, Satoshi

    2015-01-01

    A pyridinium-based task-specific ionic liquid (TSIL) with a monothioether group, [3-TPPy][NTf2], extracted typical class b metal ions, such as Ag(I), Cu(I), Pd(II), and Pt(II), in high selectivity. It was found that the composition ratio of the extracted Ag(I) and Cu(I) species depended on the TSIL concentration, and that TSIL extracted these metal ions through mono-S-coordinated complex formation at low TSIL concentrations. [3-TPPy][NTf2] can be recycled in the extraction-recovery process, which is of a great advantage for practical use in environmentally benign separation methods. PMID:26561253

  2. 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…

  3. The Effectiveness of Graphic and Tabular Presentation under Time Pressure and Task Complexity.

    ERIC Educational Resources Information Center

    Hwang, Mark I.

    1995-01-01

    Describes research that empirically tested the effects of presentation format, time, pressure, and task complexity on decision performance. The objective was to determine the most effective presentation format (i.e., graphics or tables) for the performance of tasks of varying capabilities by decision makers under time pressure. (Author/LRW)

  4. Effects of Required and Optional Exchange Tasks in Online Language Learning Environments

    ERIC Educational Resources Information Center

    Brandl, Klaus

    2012-01-01

    This study investigates the effects of an optional and required (jigsaw) task on learners' quantity and quality of use of language under synchronous and asynchronous conditions. The question raised is: Does performing either of these task types under synchronous conditions cause a compounding effect that either positively or negatively impacts…

  5. 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.…

  6. The End-State Comfort Effect in 3- to 8-Year-Old Children in Two Object Manipulation Tasks

    PubMed Central

    Knudsen, Birgit; Henning, Anne; Wunsch, Kathrin; Weigelt, Matthias; Aschersleben, Gisa

    2012-01-01

    The aim of the study was to compare 3- to 8-year-old children’s propensity to anticipate a comfortable hand posture at the end of a grasping movement (end-state comfort effect) between two different object manipulation tasks, the bar-transport task, and the overturned-glass task. In the bar-transport task, participants were asked to insert a vertically positioned bar into a small opening of a box. In the overturned-glass task, participants were asked to put an overturned-glass right-side-up on a coaster. Half of the participants experienced action effects (lights) as a consequence of their movements (AE groups), while the other half of the participants did not (No-AE groups). While there was no difference between the AE and No-AE groups, end-state comfort performance differed across age as well as between tasks. Results revealed a significant increase in end-state comfort performance in the bar-transport task from 13% in the 3-year-olds to 94% in the 8-year-olds. Interestingly, the number of children grasping the bar according to end-state comfort doubled from 3 to 4 years and from 4 to 5 years of age. In the overturned-glass task an increase in end-state comfort performance from already 63% in the 3-year-olds to 100% in the 8-year-olds was significant as well. When comparing end-state comfort performance across tasks, results showed that 3- and 4-year-old children were better at manipulating the glass as compared to manipulating the bar, most probably, because children are more familiar with manipulating glasses. Together, these results suggest that preschool years are an important period for the development of motor planning in which the familiarity with the object involved in the task plays a significant role in children’s ability to plan their movements according to end-state comfort. PMID:23112786

  7. Cognitive Processing of Scrambled Faces: Effects of Instructions and Task.

    PubMed

    Rakover, Sam S

    2015-01-01

    The present study tests Rakover and Cahlon's (2013) face-checking model, which grades 7 regular and scrambled faces on a scale of similarity to an upright regular face, by predicting the results of 2 experiments in upright and inverted orientations: Experiment 1, which uses the interest choice task (to choose from a pair of faces the one most interesting), and Experiment 2, which uses the old/new recognition task. The main results of these 2 experiments show that in comparison to Rakover and Cahlon's (2013) findings, the face-checking model preserves its ability to predict satisfactorily the order of the 7 faces in the 2 experiments especially in the upright orientation; however, the model's success in making accurate point predictions is reduced significantly in both the upright and the inverted orientations. PMID:26442344

  8. [Effects of long term mental arithmetic on physiological parameters, subjective indices and task performances].

    PubMed

    Yamada, Shimpei; Miyake, Shinji

    2007-03-01

    This study examined the effects of long term mental arithmetic on physiological parameters, subjective indices and task performances to investigate the psychophysiological changes induced by mental tasks. Fifteen male university students performed six successive trials of a ten-minute mental arithmetic task. They took a five-minute resting period before and after the tasks. CFF (Critical Flicker Fusion frequency) and subjective fatigue scores using a visual analog scale, POMS (Profiles of Mood States) and SFF (Subjective Feelings of Fatigue) were obtained after each task and resting period. The voices of participants who were instructed to speak five Japanese vowels ('a', 'i', 'u', 'e', 'o') were recorded after each block to investigate a chaotic property of vocal signals that is reported to be changed by fatigue. Subjective workload ratings were also obtained by the NASA-TLX (National Aeronautics and Space Administration-Task Load Index) after the task. Physiological signals of ECG (Electrocardiogram), PTG (Photoelectric Plethysmogram), SCL (Skin Conductance Level), TBV (Tissue Blood Volume) and Respiration were recorded for all experimental blocks. The number of answers, correct rates and average levels of task difficulty for each ten-minute task were used as task performance indices. In this experiment, the task performance did not decrease, whereas subjective fatigue increased. Activation of the sympathetic nervous system was suggested by physiological parameters. PMID:17380727

  9. Effects of a secondary task on obstacle avoidance in healthy young adults.

    PubMed

    Siu, Ka-Chun; Catena, Robert D; Chou, Li-Shan; van Donkelaar, Paul; Woollacott, Marjorie H

    2008-01-01

    Research on attention and gait stability has suggested that the process of recovering gait stability requires attentional resources, but the effect of performing a secondary task on stability during obstacle avoidance is poorly understood. Using a dual-task paradigm, the present experiment investigated the extent to which young adults are able to respond to a secondary auditory Stroop task (requiring executive attentional network resources) concurrently with obstacle crossing during gait when compared with performing unobstructed walking or sitting (control task). Our results demonstrated that as the level of difficulty in the postural task increased, there was a significant reduction in verbal response time from congruent to incongruent conditions in the auditory Stroop task, but no differences in gait parameters, indicating that these postural tasks require attention, and that young adults use a strategy of modulating the auditory Stroop task performance while keeping stable gait performance under the dual-task situations. Our findings suggest the existence of a hierarchy of control within both postural task (obstacle avoidance requires the most information processing resources) and dual-task (with gait stability being a priority) conditions. PMID:17717655

  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. 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. PMID:25680348

  12. The effect of cognitive task complexity on gait stability in adolescents following concussion.

    PubMed

    Howell, David R; Osternig, Louis R; Koester, Michael C; Chou, Li-Shan

    2014-06-01

    Concussion has been reported to result in disturbances to motor and cognitive functions. One way to examine these disturbances is through a dual-task assessment. Many secondary cognitive tasks have been proposed as appropriate tools during concussion assessment; however, task complexity has not been compared within a dual-task investigation. The purpose of this study was to prospectively examine how gait balance control was affected by three secondary cognitive tasks of varying complexity following concussion. Forty-six adolescents completed a dual-task walking protocol which included walking without any cognitive task (WALK), walking while completing a single auditory Stroop (SAS), multiple auditory Stroop (MAS), and a question and answer task (Q&A). Those who sustained a concussion (n = 23, mean age 15.4 ± 1.3 years) reported to the laboratory within 72 h of injury and in the following time increments: 1 week, 2 weeks, 1 month, and 2 months post-injury. Twenty-three healthy control subjects (mean age 15.4 ± 1.3 years), individually matched to each concussion subject, completed the same protocol in similar time increments. The concussion group demonstrated greater total center of mass (COM) medial/lateral displacement in the MAS and Q&A conditions compared with the control group. The concussion group also displayed the greatest peak COM anterior velocity in the least complex condition (WALK), and a significant decrease was observed as task complexity increased (SAS > MAS > Q&A). These findings indicate that gait balance control may be affected by task complexity following concussion and represent a way to identify motor recovery following concussion. PMID:24531643

  13. Effect of dual task type on gait and dynamic stability during stair negotiation at different inclinations.

    PubMed

    Madehkhaksar, Forough; Egges, Arjan

    2016-01-01

    Stair gait is a common daily activity with great potential risk for falls. Stairs have varying inclinations and people may perform other tasks concurrently with stair gait. This study investigated dual-task interference in the context of complex gait tasks, such as stair gait at different inclinations, a topic about which little is understood. We examined how secondary cognitive and manual tasks interfere with stair gait when a person concurrently performed tasks at different levels of complexity. Gait kinematic data and secondary task performance measures were obtained from fifteen healthy young males while ascending and descending a four-step staircase at three inclinations (17.7°, 29.4°, and 41.5°) as well as level walking. They performed a cognitive task, 'backward digit recall', a manual task, 'carrying a cup of water' and a combination of the two tasks. Gait performance and dynamic stability were assessed by gait speed and whole body center of mass (COM) range of motion in the medial-lateral direction, respectively. No significant effect of the gait task on the cognitive task performance was observed. In contrast, stair walking adversely affected the performance of the manual task compared to level walking. Overall, more difficult postural and secondary tasks resulted in a decrease in gait speed and variation in COM displacement within normal range. Results suggest that COM displacement and gait alterations might be adopted to enhance the stability, and optimize the secondary task performance while walking under challenging circumstances. Our findings are useful for balance and gait evaluation, and for future falls prediction. PMID:26410477

  14. 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. PMID:26940827

  15. The Effect of Conflict on the Quality of Group Decisions.

    ERIC Educational Resources Information Center

    Poncelow, Stacy D.

    A study was conducted to examine the relationship between the amount of conflict in a group decision-making process and the achievement of a quality decision. A task problem given to 33 college students completing a group symposium assignment in a basic public speaking and discussion course called for subjects to choose three possible topics for a…

  16. 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

  17. Effect of handedness on fMRI activation in the medial temporal lobe during an auditory verbal memory task

    PubMed Central

    Cuzzocreo, Jennifer L.; Yassa, Michael A.; Verduzco, Guillermo; Honeycutt, Nancy A.; Scott, David J.; Bassett, Susan Spear

    2009-01-01

    Several studies have shown marked differences in the neural localization of language functions in the brains of left-handed individuals when compared with right-handers. Previous experiments involving functional lateralization have demonstrated cerebral blood flow patterns that differ concordantly with subject handedness while performing language-related tasks. The effect of handedness on function in specific stages of memory processing however is a largely unexplored area. We used a paired-associates verbal memory task to elicit activation of neural areas related to declarative memory, examining the hypothesis that there are differences in activation in the medial temporal lobe (MTL) between handedness groups. 15 left-handed and 25 right-handed healthy adults were matched for all major demographic and neuropsychological variables. Functional and structural imaging data were acquired and analyzed for group differences within MTL subregions. Our results show that activation of the MTL during declarative memory processing varies with handedness. While both groups showed activation in left and right MTL subregions, the left-handed group showed a statistically significant increase in the left hippocampus and amygdala during both encoding and recall. No increases in activation were found in the right-handed group. This effect was found in the absence of any differences in performance on the verbal memory task, structural volumetric disparities or functional asymmetries. This provides evidence of functional differences between left-handers and right-handers that extends to declarative memory processes. PMID:18570207

  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. PMID:27366147

  20. 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

  1. 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

  2. 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.

  3. No psychological effect of color context in a low level vision task

    PubMed Central

    Pedley, Adam; Wade, Alex R

    2013-01-01

    Background: A remarkable series of recent papers have shown that colour can influence performance in cognitive tasks. In particular, they suggest that viewing a participant number printed in red ink or other red ancillary stimulus elements improves performance in tasks requiring local processing and impedes performance in tasks requiring global processing whilst the reverse is true for the colour blue. The tasks in these experiments require high level cognitive processing such as analogy solving or remote association tests and the chromatic effect on local vs. global processing is presumed to involve widespread activation of the autonomic nervous system. If this is the case, we might expect to see similar effects on all local vs. global task comparisons. To test this hypothesis, we asked whether chromatic cues also influence performance in tasks involving low level visual feature integration. Methods: Subjects performed either local (contrast detection) or global (form detection) tasks on achromatic dynamic Glass pattern stimuli. Coloured instructions, target frames and fixation points were used to attempt to bias performance to different task types. Based on previous literature, we hypothesised that red cues would improve performance in the (local) contrast detection task but would impede performance in the (global) form detection task.  Results: A two-way, repeated measures, analysis of covariance (2×2 ANCOVA) with gender as a covariate, revealed no influence of colour on either task, F(1,29) = 0.289, p = 0.595, partial η 2 = 0.002. Additional analysis revealed no significant differences in only the first attempts of the tasks or in the improvement in performance between trials. Discussion: We conclude that motivational processes elicited by colour perception do not influence neuronal signal processing in the early visual system, in stark contrast to their putative effects on processing in higher areas. PMID:25075280

  4. Generalizing attentional control across dimensions and tasks: evidence from transfer of proportion-congruent effects.

    PubMed

    Wühr, Peter; Duthoo, Wout; Notebaert, Wim

    2015-01-01

    Three experiments investigated transfer of list-wide proportion congruent (LWPC) effects from a set of congruent and incongruent items with different frequency (inducer task) to a set of congruent and incongruent items with equal frequency (diagnostic task). Experiments 1 and 2 mixed items from horizontal and vertical Simon tasks. Tasks always involved different stimuli that varied on the same dimension (colour) in Experiment 1 and on different dimensions (colour, shape) in Experiment 2. Experiment 3 mixed trials from a manual Simon task with trials from a vocal Stroop task, with colour being the relevant stimulus in both tasks. There were two major results. First, we observed transfer of LWPC effects in Experiments 1 and 3, when tasks shared the relevant dimension, but not in Experiment 2. Second, sequential modulations of congruency effects transferred in Experiment 1 only. Hence, the different transfer patterns suggest that LWPC effects and sequential modulations arise from different mechanisms. Moreover, the observation of transfer supports an account of LWPC effects in terms of list-wide cognitive control, while being at odds with accounts in terms of stimulus-response (contingency) learning and item-specific control. PMID:25380403

  5. 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

  6. Boundaries around Group Interaction: A Meta-Analytic Integration of the Effects of Group Size.

    ERIC Educational Resources Information Center

    Mullen, Brian; And Others

    1991-01-01

    Summarizes research comparing boundaries around larger and smaller groups. Finds that the perception of group boundary permatbility varies with group size. Reports a greater perceived distinction between the group and the individual passerby as group size increases. Describes the effects of varying group member proximity. Discusses implications…

  7. A study of idiom comprehension in children with semantic-pragmatic difficulties. Part I: Task effects on the assessment of idiom comprehension in children.

    PubMed

    Kerbel, D; Grunwell, P

    1998-01-01

    In the apparent absence of suitable measures of idiom comprehension in normally developing and clinical populations, this study examined the relationship between a newly developed play task and a more conventional definition task. On the play task, children listened to a 1.5-minute, tape-recorded story into which were embedded 12 common idioms drawn from recordings of classroom teaching and children's television. As the story was then played again, sentence by sentence, the children were required to act it out using a play set and props. For each idiom, it was possible to act out either the idiomatic or literal meaning, but only the idiomatic meaning made sense in the context. The children's actions were video-taped and then played back to the child during the definition task. For this task, the video was stopped after each idiom occurred and the children were asked what they thought each idiom meant. Four groups of children were included. Twenty-six children (aged between 6-11 years), considered to have semantic-pragmatic difficulties, were compared with two groups of mainstream children (aged 6;6-7;6 and 10;6-11;6, respectively) and with a group of children (aged between 8-11 years) diagnosed with (other) language disorders not primarily of a semantic or pragmatic nature. The results indicate that the definition task underestimated common-idiom comprehension in normally developing children and, in particular, in children diagnosed with semantic-pragmatic difficulties or (other) language disorders. Furthermore, a significant difference in idiom comprehension between the two clinical groups evidenced on the play task was entirely masked on the definition task. It appeared that the expressive and metalinguistic demands of the definition task had a greater negative effect on the group of children with language disorders than on the children with semantic-pragmatic difficulties. Possible mechanisms through which the play task might have overestimated or underestimated

  8. The Brain Effective Connectivity of Chinese during Rhyming Task.

    PubMed

    Zhu, Linlin; Niu, Zhendong; Nie, Yaoxin; Yang, Yang; Li, Ke; Jin, Zhen; Wei, Jieyao

    2016-01-01

    With regard to brain language processing, the activation patterns have been well studied, and recently there are great interest in the connectivity models. The crucial brain areas for phonological processing involves left inferior frontal gyrus (LIFG), left inferior parietal lobule (LIPL) and left posterior middle temporal gyrus (LpMTG). Specially in Chinese processing, the left middle frontal gyrus (LMFG) is considered as an essential region. However, the connectivity pattern among these brain areas is not well understood. In this study, a rhyming experiment of Chinese was conducted, and the Dynamic causal modeling (DCM) and the Bayesian model selection (BMS) were used to examine the interaction between brain regions and choose the best model for rhyming task of Chinese. By examining the interactions, it was found that LMFG exerted inhibitory modulation on LIPL and LIFG; the phonological processing enhanced the connection from LIPL to LIFG and LMFG, which suggested the important roles of these connections for the increased phonological load; And LpMTG modulated LIFG and LMFG negatively, and LIPL positively under rhyming judgment task. PMID:27583349

  9. 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

  10. 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. PMID:25642826

  11. 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

    2015-01-01

    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. PMID:26666706

  12. Effect of handedness on brain activity patterns and effective connectivity network during the semantic task of Chinese characters

    PubMed Central

    Gao, Qing; Wang, Junping; Yu, Chunshui; Chen, Huafu

    2015-01-01

    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. PMID:26666706

  13. Effects of sleep deprivation on different phases of memory in the rat: dissociation between contextual and tone fear conditioning tasks

    PubMed Central

    Rossi, Vanessa Contatto; Tiba, Paula Ayako; Moreira, Karin Di Monteiro; Ferreira, Tatiana Lima; Oliveira, Maria Gabriela Menezes; Suchecki, Deborah

    2014-01-01

    Numerous studies show that sleep deprivation (SD) impacts negatively on cognitive processes, including learning and memory. Memory formation encompasses distinct phases of which acquisition, consolidation and retrieval are better known. Previous studies with pre-training SD induced by the platform method have shown impairment in fear conditioning tasks. Nonetheless, pre-training manipulations do not allow the distinction between effects on acquisition and/or consolidation, interfering, ultimately, on recall of/performance in the task. In the present study, animals were first trained in contextual and tone fear conditioning (TFC) tasks and then submitted to SD with the purpose to evaluate the effect of this manipulation on different stages of the learning process, e.g., in the uptake of (new) information during learning, its encoding and stabilization, and the recall of stored memories. Besides, we also investigated the effect of SD in the extinction of fear memory and a possible state-dependent learning induced by this manipulation. For each task (contextual or TFC), animals were trained and then distributed into control, not sleep-deprived (CTL) and SD groups, the latter being submitted to the modified multiple platform paradigm for 96 h. Subsets of eight rats in each group/experiment were submitted to the test of the tasks, either immediately or at different time intervals after SD. The results indicated that (a) pre- but not post-training SD impaired recall in the contextual and TFC; (b) this impairment was not state-dependent; and (c) in the contextual fear conditioning (CFC), pre-test SD prevented extinction of the learned task. Overall, these results suggest that SD interferes with acquisition, recall and extinction, but not necessarily with consolidation of emotional memory. PMID:25426040

  14. Do you really represent my task? Sequential adaptation effects to unexpected events support referential coding for the joint Simon effect.

    PubMed

    Klempova, Bibiana; Liepelt, Roman

    2016-07-01

    Recent findings suggest that a Simon effect (SE) can be induced in Individual go/nogo tasks when responding next to an event-producing object salient enough to provide a reference for the spatial coding of one's own action. However, there is skepticism against referential coding for the joint Simon effect (JSE) by proponents of task co-representation. In the present study, we tested assumptions of task co-representation and referential coding by introducing unexpected double response events in a joint go/nogo and a joint independent go/nogo task. In Experiment 1b, we tested if task representations are functionally similar in joint and standard Simon tasks. In Experiment 2, we tested sequential updating of task co-representation after unexpected single response events in the joint independent go/nogo task. Results showed increased JSEs following unexpected events in the joint go/nogo and joint independent go/nogo task (Experiment 1a). While the former finding is in line with the assumptions made by both accounts (task co-representation and referential coding), the latter finding supports referential coding. In contrast to Experiment 1a, we found a decreased SE after unexpected events in the standard Simon task (Experiment 1b), providing evidence against the functional equivalence assumption between joint and two-choice Simon tasks of the task co-representation account. Finally, we found an increased JSE also following unexpected single response events (Experiment 2), ruling out that the findings of the joint independent go/nogo task in Experiment 1a were due to a re-conceptualization of the task situation. In conclusion, our findings support referential coding also for the joint Simon effect. PMID:25833374

  15. The interactive effect of exercise intensity and task difficulty on human cognitive processing.

    PubMed

    Kamijo, Keita; Nishihira, Yoshiaki; Higashiura, Takuro; Kuroiwa, Kazuo

    2007-08-01

    The interactive effect of exercise intensity and task difficulty on human cognitive processing was investigated using the P3 component of an event-related brain potential (ERP). Exercise intensity was established using Borg's rating of perceived exertion (RPE) scale, and task difficulty was manipulated using a modified flanker task comprised of incongruent and neutral trials. Twelve participants (22 to 30 y) performed the flanker task during a baseline session, and again after light (RPE: 11), moderate (RPE: 13), and hard (RPE: 15) cycling exercise. Results indicated that the P3 amplitude increases across task conditions following light and moderate cycling, but not during hard cycling, relative to baseline, suggesting that P3 amplitude may change in an inverted U fashion by as a result of acute exercise intensity. Additionally, the expected delay in P3 latency for incongruent relative to neutral trials was observed during the baseline condition. However, following acute exercise these task condition differences diminished across exercise intensities. Moreover, reaction times following all exercise conditions were shorter when compared to the baseline condition. These findings suggest that P3 latency is more sensitive to task difficulty manipulated by a flanker task than behavioral measures, and P3 latency during trials requiring greater executive control processes might be more sensitive to the effects of acute exercise than tasks requiring minimal effort. PMID:17482699

  16. 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…

  17. 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…

  18. The Effects of Background Music on Primary School Pupils' Task Performance.

    ERIC Educational Resources Information Center

    Hallam, Susan; Price, John; Katsarou, Georgia

    2002-01-01

    Presents two studies that explored the effects of music perceived as calming and relaxing on arithmetic and memory performance tasks of 10- to 12-year-old children. Reports that the calming music led to better performance on both tasks when compared with the non-music condition. Includes references. (CMK)

  19. Effects of a Breakfast Program on On-Task Behaviors of Vocational High School Students.

    ERIC Educational Resources Information Center

    Bro, Robert T.

    1996-01-01

    This study examined whether an in-school breakfast program could increase on-task behaviors of 18 high school students. Vocational and academic students participated in the program and completed surveys. Teachers collected observational data. Results indicated that the program effectively increased on-task behaviors in both settings, and that…

  20. 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.…

  1. The Effect of Different Modes of Task Orientation on Observational Attainment in Practical Chemistry

    ERIC Educational Resources Information Center

    Kempa, R. F.; Ward, J. E.

    1975-01-01

    Examines the effect of three different modes of task orientation on observational attainment in practical chemistry. Results include the overall performance on the chemistry observation test and an analysis of the influence of the complexity of observational tasks on observational attainment. (Author/GS)

  2. 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…

  3. 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…

  4. The Effects of a Concurrent Task on Human Optimization and Self Control

    ERIC Educational Resources Information Center

    Reed, Phil; Thompson, Caitlin; Osborne, Lisa A.; McHugh, Louise

    2011-01-01

    Memory deficits have been shown to hamper decision making in a number of populations. In two experiments, participants were required to select one of three alternatives that varied in reinforcer amount and delay, and the effect of a concurrent task on a behavioral choice task that involved making either an impulsive, self-controlled, or optimal…

  5. 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…

  6. 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…

  7. 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)

  8. 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…

  9. Effects of Visual Cues upon the Vocational Task Performance of Students with Mental Retardation.

    ERIC Educational Resources Information Center

    Martin, James E.; And Others

    1990-01-01

    This study compared use of trainer demonstrations and use of visual cues across varying difficulties of task, by 20 mentally retarded secondary-aged students. Results found that photographs and line drawings were more effective with mildly/moderately retarded students than demonstrations when working with complex tasks. No differences were found…

  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 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…

  12. A Typology of Task Characteristics and Their Effects on Student Engagement

    ERIC Educational Resources Information Center

    Mitchell, Ian; Carbone, Angela

    2011-01-01

    The tasks that teachers set have a major effect on how students approach learning, however the nature of this interaction has not been explored comprehensively, nor against current understandings of quality learning. This paper details the development of a typology of task characteristics that lead to four different types of engagement associated…

  13. 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

  14. Performance monitoring following total sleep deprivation: effects of task type and error rate.

    PubMed

    Renn, Ryan P; Cote, Kimberly A

    2013-04-01

    There is a need to understand the neural basis of performance deficits that result from sleep deprivation. Performance monitoring tasks generate response-locked event-related potentials (ERPs), generated from the anterior cingulate cortex (ACC) located in the medial surface of the frontal lobe that reflect error processing. The outcome of previous research on performance monitoring during sleepiness has been mixed. The purpose of this study was to evaluate performance monitoring in a controlled study of experimental sleep deprivation using a traditional Flanker task, and to broaden this examination using a response inhibition task. Forty-nine young adults (24 male) were randomly assigned to a total sleep deprivation or rested control group. The sleep deprivation group was slower on the Flanker task and less accurate on a Go/NoGo task compared to controls. General attentional impairments were evident in stimulus-locked ERPs for the sleep deprived group: P300 was delayed on Flanker trials and smaller to Go-stimuli. Further, N2 was smaller to NoGo stimuli, and the response-locked ERN was smaller on both tasks, reflecting neurocognitive impairment during performance monitoring. In the Flanker task, higher error rate was associated with smaller ERN amplitudes for both groups. Examination of ERN amplitude over time showed that it attenuated in the rested control group as error rate increased, but such habituation was not apparent in the sleep deprived group. Poor performing sleep deprived individuals had a larger Pe response than controls, possibly indicating perseveration of errors. These data provide insight into the neural underpinnings of performance failure during sleepiness and have implications for workplace and driving safety. PMID:23384887

  15. 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

  16. Effects of paired-object affordance in search tasks across the adult lifespan.

    PubMed

    Wulff, Melanie; Stainton, Alexandra; Rotshtein, Pia

    2016-06-01

    The study investigated the processes underlying the retrieval of action information about functional object pairs, focusing on the contribution of procedural and semantic knowledge. We further assessed whether the retrieval of action knowledge is affected by task demands and age. The contribution of procedural knowledge was examined by the way objects were selected, specifically whether active objects were selected before passive objects. The contribution of semantic knowledge was examined by manipulating the relation between targets and distracters. A touchscreen-based search task was used testing young, middle-aged, and elderly participants. Participants had to select by touching two targets among distracters using two search tasks. In an explicit action search task, participants had to select two objects which afforded a mutual action (e.g., functional pair: hammer-nail). Implicit affordance perception was tested using a visual color-matching search task; participants had to select two objects with the same colored frame. In both tasks, half of the colored targets also afforded an action. Overall, middle-aged participants performed better than young and elderly participants, specifically in the action task. Across participants in the action task, accuracy was increased when the distracters were semantically unrelated to the functional pair, while the opposite pattern was observed in the color task. This effect was enhanced with increased age. In the action task all participants utilized procedural knowledge, i.e., selected the active object before the passive object. This result supports the dual-route account from vision to action. Semantic knowledge contributed to both the action and the color task, but procedural knowledge associated with the direct route was primarily retrieved when the task was action-relevant. Across the adulthood lifespan, the data show inverted U-shaped effects of age on the retrieval of action knowledge. Age also linearly increased the

  17. Attitude Differences and Task Performance for Black and White Recruits in Problem-Solving Groups of Differing Size and Racial Composition. Technical Report 75-1.

    ERIC Educational Resources Information Center

    Ruhe, John A.; Allen, William R.

    In this field study, black and white naval recruits and 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 composition (25% black tetrads, 75% black tetrads, racially balanced dyads and tetrads) were compared in measures…

  18. Self-enhancing effect of social feedback on cognitive task performance.

    PubMed

    Waldie, K E; Mosley, J L

    1996-05-01

    The influence of feedback on the cognitive task performance of individuals with high and low self-esteem was assessed (Coopersmith Self-Esteem Inventory, Form A). A median split technique segregated each group (30 adults with mental retardation and 30 MA-matched controls) into high and low self-esteem individuals. All subjects performed two memory tasks (easy, difficult) but were randomly assigned to only one of three feedback conditions (social, computer, and no feedback). Findings indicated that social feedback can alter the normally positive relation between self-esteem and cognitive task performance. PMID:8735575

  19. The effects of task-oriented versus repetitive bilateral arm training on upper limb function and activities of daily living in stroke patients

    PubMed Central

    Song, Gui Bin

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effects of task-oriented bilateral arm training and repetitive bilateral arm training on upper limb function and activities of daily living in stroke patients. [Subjects] Forty patients with hemiplegia resulting from stroke were divided into a task orientied bilateral arm training group (n=20) and a repetitive bilateral arm training group (n=20). [Methods] The task-oriented group underwent bilateral arm training with 5 functional tasks, and the repetitive group underwent bilateral arm training with rhythmin auditory cueing for 30 minutes/day, 5 times/week, for 12 weeks. [Results] The upper limb function and the ability to perform activities of daily living improved significantly in both groups. Although there were significant differences between the groups, the task-oriented group showed greater improvement in upper limb function and activities of daily living. [Conclusion] We recommend bilateral arm training as well as adding functional task training as a clinical intervention to improve upper limb function activities of daily living in patients with hemiplegia. PMID:26157217

  20. 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

  1. Expectancy of stress-reducing aromatherapy effect and performance on a stress-sensitive cognitive task.

    PubMed

    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

  2. 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. PMID:26057417

  3. 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

  4. Effective Scheduling Algorithms for I/O Blocking with a Multi-Frame Task Model

    NASA Astrophysics Data System (ADS)

    Ding, Shan; Tomiyama, Hiroyuki; Takada, Hiroaki

    A task that suspends itself to wait for an I/O completion or to wait for an event from another node in distributed environments is called an I/O blocking task. Conventional hard real-time scheduling theories use framework of rate monotonic analysis (RMA) to schedule such I/O blocking tasks. However, most of them are pessimistic. In this paper, we propose effective algorithms that can schedule a task set which has I/O blocking tasks under dynamic priority assignment. We present a new critical instant theorem for the multi-frame task set under dynamic priority assignment. The schedulability is analyzed under the new critical instant theorem. For the schedulability analysis, this paper presents saturation summation which is used to calculate the maximum interference function (MIF). With saturation summation, the schedulability of a task set having I/O blocking tasks can be analyzed more accurately. We propose an algorithm which is called Frame Laxity Monotonic Scheduling (FLMS). A genetic algorithm (GA) is also applied. From our experiments, we can conclude that FLMS can significantly reduce the calculation time, and GA can improve task schedulability ratio more than is possible with FLMS.

  5. Effects of Group Norms on Children's Intentions to Bully

    ERIC Educational Resources Information Center

    Nesdale, Drew; Durkin, Kevin; Maass, Anne; Kiesner, Jeff; Griffiths, Judith A.

    2008-01-01

    A minimal group study examined the effect of peer group norms on children's direct and indirect bullying intentions. Prior to an inter-group drawing competition, children (N = 85) aged seven and nine years were assigned to a group that had a norm of out-group dislike or out-group liking. Results indicated that, regardless of group norms, the…

  6. 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. PMID:24874509

  7. 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

  8. Effects of muscle fatigue on gait characteristics under single and dual-task conditions in young and older adults

    PubMed Central

    2010-01-01

    Background Muscle fatigue and dual-task walking (e.g., concurrent performance of a cognitive interference (CI) while walking) represent major fall risk factors in young and older adults. Thus, the objectives of this study were to examine the effects of muscle fatigue on gait characteristics under single and dual-task conditions in young and older adults and to determine the impact of muscle fatigue on dual-task costs while walking. Methods Thirty-two young (24.3 ± 1.4 yrs, n = 16) and old (71.9 ± 5.5 yrs, n = 16) healthy active adults participated in this study. Fatigue of the knee extensors/flexors was induced by isokinetic contractions. Subjects were tested pre and post fatigue, as well as after a 5 min rest. Tests included the assessment of gait velocity, stride length, and stride length variability during single (walking), and dual (CI+walking) task walking on an instrumented walkway. Dual-task costs while walking were additionally computed. Results Fatigue resulted in significant decreases in single-task gait velocity and stride length in young adults, and in significant increases in dual-task gait velocity and stride length in older adults. Further, muscle fatigue did not affect dual-task costs during walking in young and older adults. Performance in the CI-task was improved in both age groups post-fatigue. Conclusions Strategic and/or physiologic rationale may account for the observed differences in young and older adults. In terms of strategic rationale, older adults may walk faster with longer strides in order to overcome the feeling of fatigue-induced physical discomfort as quickly as possible. Alternatively, older adults may have learned how to compensate for age-related and/or fatigue-induced muscle deficits during walking by increasing muscle power of synergistic muscle groups (e.g., hip flexors). Further, a practice and/or learning effect may have occurred from pre to post testing. Physiologic rationale may comprise motor unit remodeling in old age

  9. The Effect of Personality on Collaborative Task Performance and Interaction

    NASA Astrophysics Data System (ADS)

    Givney, Sinéad Mc; Smeaton, Alan F.; Lee, Hyowon

    Collocated, multi-user technologies, which support group-work are becoming increasingly popular. Examples include MERL’s Diamondtouch and Microsoft’s Surface, both of which have evolved from research prototypes to commercial products. Many applications have been developed for such technologies which support the work and entertainment needs of small groups of people. None of these applications however, have been studied in terms of the interactions and performances of their users with regards to their personality. In this paper, we address this research gap by conducting a series of user studies involving dyads working on a number of multi-user applications on the DiamondTouch tabletop device.

  10. Task and structural correlates of organizational effectiveness in private psychiatric hospitals.

    PubMed Central

    Mark, B

    1985-01-01

    This exploration of the relationships between task and structural variables and two dimensions of organizational effectiveness in 76 private psychiatric hospitals revealed that high levels of centralization were associated with patient care effectiveness. High levels of centralization and formalization were associated with administrative effectiveness. An enhancing effect of organizational structure is suggested as contributing to organizational effectiveness. PMID:3891685

  11. 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…

  12. 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…

  13. 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…

  14. Spatial effects, sampling errors, and task specialization in the honey bee.

    PubMed

    Johnson, B R

    2010-05-01

    Task allocation patterns should depend on the spatial distribution of work within the nest, variation in task demand, and the movement patterns of workers, however, relatively little research has focused on these topics. This study uses a spatially explicit agent based model to determine whether such factors alone can generate biases in task performance at the individual level in the honey bees, Apis mellifera. Specialization (bias in task performance) is shown to result from strong sampling error due to localized task demand, relatively slow moving workers relative to nest size, and strong spatial variation in task demand. To date, specialization has been primarily interpreted with the response threshold concept, which is focused on intrinsic (typically genotypic) differences between workers. Response threshold variation and sampling error due to spatial effects are not mutually exclusive, however, and this study suggests that both contribute to patterns of task bias at the individual level. While spatial effects are strong enough to explain some documented cases of specialization; they are relatively short term and not explanatory for long term cases of specialization. In general, this study suggests that the spatial layout of tasks and fluctuations in their demand must be explicitly controlled for in studies focused on identifying genotypic specialists. PMID:20351761

  15. 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.

  16. Effects and timing of developmental peer appraisals in self-managing work groups.

    PubMed

    Druskat, V U; Wolff, S B

    1999-02-01

    This study used a repeated measures time-series design to examine the immediate and longer term impact of a structured, face-to-face developmental peer appraisal on 294 undergraduates in 44 self-managing work groups (SMWGs) and 217 MBA students in 36 SMWGs. Results revealed an immediate positive impact on perceptions of open communication, task motivation, social loafing, group viability, cohesion, and satisfaction. Also, the effects of the peer appraisal were not dependent on the perceived ratio of positive to negative feedback, and the enduring impact of the appraisal was influenced by its timing relative to task deadline. Overall, results emphasized that peer appraisals can have a positive effect on relationships and task focus, are influenced by temporal context, and have great potential for work teams. PMID:10089817

  17. The management of cancer-related breakthrough pain: recommendations of a task group of the Science Committee of the Association for Palliative Medicine of Great Britain and Ireland.

    PubMed

    Davies, Andrew N; Dickman, Andrew; Reid, Colette; Stevens, Anna-Marie; Zeppetella, Giovambattista

    2009-04-01

    A task group of the Science Committee of the Association for Palliative Medicine of Great Britain and Ireland (APM) was convened to produce some up-to-date, evidence-based, practical, clinical guidelines on the management of cancer-related breakthrough pain in adults. On the basis of a review of the literature, the task group was unable to make recommendations about any individual interventions, but was able to make a series of 12 recommendations about certain generic strategies. However, most of the aforementioned recommendations are based on limited evidence (i.e., case series, expert opinion). The task group also proposed a definition of breakthrough pain, and some diagnostic criteria for breakthrough pain. PMID:18707904

  18. 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

  19. 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…

  20. The Effect of Locus of Control and Locus of Reinforcement on Academic Task Persistence

    ERIC Educational Resources Information Center

    Morris, Susan; Messer, Stanley B.

    1978-01-01

    Examines the differential effectiveness of using external reinforcement versus self reinforcement to increase the task persistence of children characterized by internal or external locus of control. Subjects were 153 fourth and fifth grade boys. (BD)

  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. Action Effects and Task Knowledge: The Influence of Anticipatory Priming on the Identification of Task-Related Stimuli in Experts.

    PubMed

    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

  3. The Effect of Time-on-Task on Student Grades and Grade Expectations

    ERIC Educational Resources Information Center

    Guillaume, Darrell W.; Khachikian, Crist Simon

    2011-01-01

    The effects of students' attitudes on time devoted to a course (i.e. time-on-task), and the subsequent effects of this time-on-task on their performance in the course and their overall grade point average (GPA) were studied. Over a three-year period, engineering students (N = 231) were surveyed in weeks one, three, seven (after midterms) and 10…

  4. 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,…

  5. Evaluating the basis of the between-group production effect in recognition.

    PubMed

    Taikh, Alexander; Bodner, Glen E

    2016-06-01

    Reading a list of words aloud can improve recognition over silently reading them. This between-groups production effect (PE) cannot be due to relative distinctiveness because each group studies only 1 type of item. We tested 2 other possibilities. By a strategy account, a pure-aloud group might benefit from use of a production-based distinctiveness strategy at test (e.g., "Did I say this word aloud?"). By a strength account, aloud items may simply be more strongly encoded than silent items. To evaluate these accounts, we tested whether a between-group PE occurs when participants experience a salient within-group manipulation of font size, generation, or imagery at study. The answer was yes, except when imagery was the within-group task. This pattern, and aspects of participants' strategy reports, fit well with a strategy account if it is assumed that the imagery task led participants to abandon a production-based strategy. However, many of our findings were also compatible with an evaluated strength account if it is assumed that the imagery task led participants to abandon evaluating memory strength. In conjunction with recent findings, we suggest that multiple processes may contribute to the PE, and the relevant subset in play will differ as a function of study design, study task, and memory test. (PsycINFO Database Record PMID:27244360

  6. 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

  7. 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). PMID:23860419

  8. Effects of anxiety on running with and without an aiming task.

    PubMed

    Nibbeling, Nicky; Daanen, Hein A M; Gerritsma, Rens M; Hofland, Rianne M; Oudejans, Raôul R D

    2012-01-01

    State anxiety is known to affect far aiming tasks, but less is known about the effects of state anxiety on running and aiming while running. Therefore, in the current study participants ran on a treadmill at their preferred speed in a low- and high-anxiety condition. In both conditions, running was combined with dart throwing in the last minutes. Results showed that attention shifted away from task execution with elevated levels of anxiety. Furthermore, gait patterns were more conservative and oxygen uptake was higher with anxiety. In addition, performance and efficiency on the dart throwing task also decreased with anxiety. These findings are in line with attentional control theory and provide an indication that state anxiety not only affects aiming tasks but also tasks that rely heavily on the aerobic system. Moreover, findings indicate that when combined, running, aiming, and anxiety all compete for attention leading to suboptimal attentional control and possibly a decrease in performance. PMID:22106940

  9. Speech variability effects on recognition accuracy associated with concurrent task performance by pilots

    NASA Technical Reports Server (NTRS)

    Simpson, C. A.

    1985-01-01

    In the present study of the responses of pairs of pilots to aircraft warning classification tasks using an isolated word, speaker-dependent speech recognition system, the induced stress was manipulated by means of different scoring procedures for the classification task and by the inclusion of a competitive manual control task. Both speech patterns and recognition accuracy were analyzed, and recognition errors were recorded by type for an isolated word speaker-dependent system and by an offline technique for a connected word speaker-dependent system. While errors increased with task loading for the isolated word system, there was no such effect for task loading in the case of the connected word system.

  10. Mindfulness, movement control, and attentional focus strategies: effects of mindfulness on a postural balance task.

    PubMed

    Kee, Ying Hwa; Chatzisarantis, Nikos; Kong, Pui Wah; Chow, Jia Yi; Chen, Lung Hung

    2012-10-01

    We examined whether the momentary induction of state mindfulness benefited subsequent balance performance, taking into consideration the effects of dispositional mindfulness. We also tested whether our mindfulness induction, grounded in sustaining moment-to-moment attention, influenced the attentional focus strategies that were adopted by the participants during the balancing task. Balance performance was ascertained based on approximate entropy (ApEn) of the center of pressure (COP) data. The study involved 32 males (age: M = 22.8, SD = 1.94) who were randomly assigned to the mindfulness or control group. Using difference in pretest to posttest performance based on the medio-lateral movements as the dependent variable, the test for interaction showed that the mindfulness induction was more effective for participants with higher dispositional mindfulness. Participants who underwent mindfulness induction also reported greater use of external focus strategies than those in the control group. Results suggest that momentary mindful attention could benefit balance performance and affect the use of attentional focus strategies during movement control. PMID:23027228

  11. Effects of domain-specific exercise load on speed and accuracy of a domain-specific perceptual-cognitive task.

    PubMed

    Schapschröer, M; Baker, J; Schorer, J

    2016-08-01

    In the context of perceptual-cognitive expertise it is important to know whether physiological loads influence perceptual-cognitive performance. This study examined whether a handball specific physical exercise load influenced participants' speed and accuracy in a flicker task. At rest and during a specific interval exercise of 86.5-90% HRmax, 35 participants (experts: n=8, advanced: n=13, novices, n=14) performed a handball specific flicker task with two types of patterns (structured and unstructured). For reaction time, results revealed moderate effect sizes for group, with experts reacting faster than advanced and advanced reacting faster than novices, and for structure, with structured videos being performed faster than unstructured ones. A significant interaction for structure×group was also found, with experts and advanced players faster for structured videos, and novices faster for unstructured videos. For accuracy, significant main effects were found for structure with structured videos solved more accurately. A significant interaction for structure×group was revealed, with experts and advanced more accurate for structured scenes and novices more accurate for unstructured scenes. A significant interaction was also found for condition×structure; at rest, unstructured and structured scenes were performed with the same accuracy while under physical exercise, structured scenes were solved more accurately. No other interactions were found. These results were somewhat surprising given previous work in this area, although the impact of a specific physical exercise on a specific perceptual-cognitive task may be different from those tested generally. PMID:27173640

  12. 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…

  13. Blue or red? Exploring the effect of color on cognitive task performances.

    PubMed

    Mehta, Ravi; Zhu, Rui Juliet

    2009-02-27

    Existing research reports inconsistent findings with regard to the effect of color on cognitive task performances. Some research suggests that blue or green leads to better performances than red; other studies record the opposite. Current work reconciles this discrepancy. We demonstrate that red (versus blue) color induces primarily an avoidance (versus approach) motivation (study 1, n = 69) and that red enhances performance on a detail-oriented task, whereas blue enhances performance on a creative task (studies 2 and 3, n = 208 and 118). Further, we replicate these results in the domains of product design (study 4, n = 42) and persuasive message evaluation (study 5, n = 161) and show that these effects occur outside of individuals' consciousness (study 6, n = 68). We also provide process evidence suggesting that the activation of alternative motivations mediates the effect of color on cognitive task performances. PMID:19197022

  14. Task Dependent Lexicality Effects Support Interactive Models of Reading: A Meta-Analytic Neuroimaging Review

    PubMed Central

    McNorgan, Chris; Chabal, Sarah; O’Young, Daniel; Lukic, Sladjana; Booth, James R.

    2015-01-01

    Models of reading must explain how orthographic input activates a phonological representation, and elicits the retrieval of word meaning from semantic memory. Comparisons between tasks that theoretically differ with respect to the degree to which they rely on connections between orthographic, phonological and semantic systems during reading can thus provide valuable insight into models of reading, but such direct comparisons are not well-represented in the literature. An ALE meta-analysis explored lexicality effects directly contrasting words and pseudowords using the lexical decision task and overt or covert naming, which we assume rely most on the semantic and phonological systems, respectively. Interactions between task and lexicality effects demonstrate that different demands of the lexical decision and naming tasks lead to different manifestations of lexicality effects. PMID:25524364

  15. Dosimetric evaluation of a commercial 3D treatment planning system using the AAPM Task Group 23 test package.

    PubMed

    Casanova Borca, Valeria; Pasquino, Massimo; Bresciani, Sara; Catuzzo, Paola; Ozzello, Franca; Tofani, Santi

    2005-03-01

    The accuracy of the dose calculation algorithm is one of the most critical steps in assessing the radiotherapy treatment to achieve the 5% accuracy in dose delivery, which represents the suggested limit to increase the complication-free local control of tumor. We have used the AAPM Task Group 23 (TG-23) test package for clinical photon external beam therapy to evaluate the accuracy of the new version of the PLATO TPS algorithm. The comparison between tabulated values and calculated ones has been performed for 266 and 297 dose values for the 4 and 18 MV photon beams, respectively. Dose deviations less than 2% were found in the 98.5%- and 90.6% analyzed dose points for the two considered energies, respectively. Larger deviations were obtained for both energies, in large dose gradients, such as the build-up region or near the field edges and blocks. As far as the radiological field width is concerned, 64 points were analyzed for both the energies: 53 points (83%) and 64 points (100%) were within +/-2 millimeters for the 4 and 18 MV photon beams, respectively. The results show the good accuracy of the algorithm either in simple geometry beam conditions or in complex ones, in homogeneous medium, and in the presence of inhomogeneities, for low and high energy beams. Our results fit well the data reported by several authors related to the calculation accuracy of different treatment planning systems (TPSs) (within a mean value of 0.7% and 1.2% for 4 and 18 MV respectively). The TG-23 test package can be considered a powerful instrument to evaluate dose calculation accuracy, and as such may play an important role in a quality assurance program related to the commissioning of a new TPS. PMID:15839346

  16. The effect of mutual task sharing on the number of needed health workers at the Iranian Health Posts; Does task sharing increase efficiency?

    PubMed Central

    Fakhri, Ali; Aryankhesal, Aidin

    2015-01-01

    Background: Nowadays task sharing is a way to optimize utilization of human resources for health. This study was designed to assess the effect of task sharing, mutually between midwives and Family Health Workforces (FHWs), on the number of needed staff across the Iranian Health Posts. Methods: The workload and required number of midwives and FHWs in a Health Post were calculated and compared in two different scenarios of task division using a combined approach for estimating the number of required staff. In the first scenario, the midwives and FHWs provide their specialized services and in the second one, using mutual task sharing, a midwife provides all services traditionally delivered by FHWs and each FHW provides prenatal care in addition to the special tasks. Sensitivity analysis was performed to estimate the effects of different hypotheses. Results: By applying mutual task sharing, the required number of staff for Health Posts was one midwife and two FHWs for a standard population of 12,500; one FHW less than that when no task sharing was applied. Sensitivity analysis illustrated that the number of needed staff is the same in both scenarios when different demographic, epidemiologic, cultural and organizational conditions were applied. Conclusion: Task sharing can reduce the required number of health workers which increases efficiency and productivity at health facilities. However, apart from a need to consider quality, acceptability, and feasibility of care, increasing efficiency must be judged against the contextual circumstances. PMID:26340390

  17. 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.

  18. Intracranial stereotactic positioning systems: Report of the American Association of Physicists in Medicine Radiation Therapy Committee Task Group no. 68.

    PubMed

    Lightstone, A W; Benedict, Stanley H; Bova, Frank J; Solberg, Timothy D; Stern, Robin L

    2005-07-01

    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. PMID:16121596

  19. Effects of task orientation on subsequent source memory as revealed by functional MRI.

    PubMed

    Guo, Xiuyan; Zhu, Lei; Zheng, Li; Li, Jianqi; Wang, Qianfeng; Yang, Zhiliang

    2013-09-15

    Episodic memories are composed of various interrelated elements, including those specific to items of central interest and those pertaining to related features, such as the color, shape, size, spatial location, temporal order, and media or modalities of presentation. Memory about a core item (such as a word, object, or picture) is called item memory while memory about the context or related fea-tures of a core item is defined as source memory. What determines which sources within an episode are successfully remembered is of particular interest to researchers. Behavioral evidence suggests that the orientation of a memory task influences whether the related source of the item will be re-membered later. This study explored changes in the hippocampus and prefrontal cortex while par-ticipants completed two tasks: an item-oriented task and a source-oriented task. We used functional MRI to investigate the neural mechanisms by which task orientation influences source encoding. We found that subsequent source memory effects in the right prefrontal cortex and hippocampus were modulated by task orientation, whereas task orientation modulated item memory effects in the prefrontal cortex. These findings highlight the possibility that the hippocampus contributes to the intentional encoding of item-source associations, whereas the prefrontal cortex is biased toward processing information to which attention is directed. PMID:25206552

  20. The effect of class-based task-oriented circuit training on the self-satisfaction of patients with chronic stroke

    PubMed Central

    Song, Hyun Seung; Kim, Jin Young; Park, Seong Doo

    2015-01-01

    [Purpose] This study aimed to determine the difference in self-satisfaction in patients by comparing class-based task-oriented circuit training (CTCT) and individual-based task-oriented circuit training (ITCT). [Subjects and Methods] The subjects were 30 patients who had been diagnosed with hemiplegia due to stroke more than six month previously. They were divided into Group I (n=9) for conventional therapy, Group II (n=10) for conventional therapy and ITCT, and Group III (n=11) for conventional therapy and CTCT. In order to determine self-satisfaction as a psychological factor in patients, we used a self-esteem scale (SES), motivation of rehabilitation scale (MR), and relationship change (RCS) scale. [Results] SES, MR, and RCS, which were measured to determine self satisfaction as a psychological factor were significantly different between groups. The Bonferroni post hoc test revealed a significant difference between Group I and Group III in SES, a significant difference between Group I and Group III and Group II and Group III in MR, and a significant difference between Group I and Group III were found. [Conclusion] Based on the above results, task-oriented circuit training was more effective when performed in a class than when performed individually in terms of self-satisfaction. Based on this result, we determined that CTCT has as positive an effect on the mental aspects of stroke patients compared with ITCT. PMID:25642055

  1. 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.

  2. Developmental changes in using verbal self-cueing in task-switching situations: the impact of task practice and task-sequencing demands.

    PubMed

    Kray, Jutta; Gaspard, Hanna; Karbach, Julia; Blaye, Agnès

    2013-01-01

    In this study we examined whether developmental changes in using verbal self-cueing for task-goal maintenance are dependent on the amount of task practice and task-sequencing demands. To measure task-goal maintenance we applied a switching paradigm in which children either performed only task A or B in single-task blocks or switched between them on every second trial in mixed-task blocks. Task-goal maintenance was determined by comparing the performance between both blocks (mixing costs). The influence of verbal self-cueing was measured by instructing children to either name the next task aloud or not to verbalize during task preparation. Task-sequencing demands were varied between groups whereas one group received spatial task cues to support keeping track of the task sequence, while the other group did not. We also varied by the amount of prior practice in task switching while one group of participants practiced task switching first, before performing the task naming in addition, and the other group did it vice versa. Results of our study investigating younger (8-10 years) and older children (11-13 years) revealed no age differences in beneficial effects of verbal self-cueing. In line with previous findings, children showed reduced mixing costs under task-naming instructions and under conditions of low task-sequence demands (with the presence of spatial task cues). Our results also indicated that these benefits were only obtained for those groups of children that first received practice in task switching alone with no additional verbalization instruction. These findings suggest that internal task-cueing strategies can be efficiently used in children but only if they received prior practice in the underlying task so that demands on keeping and coordinating various instructions are reduced. Moreover, children benefitted from spatial task cues for better task-goal maintenance only if no verbal task-cueing strategy was introduced first. PMID:24381566

  3. The group-contagion effect: the influence of spatial groupings on perceived contagion and preferences.

    PubMed

    Mishra, Arul; Mishra, Himanshu; Nayakankuppam, Dhananjay

    2009-07-01

    We used contagion theory as a framework for studying the influence of spread of qualities in a group. We found that people's preferences change depending on how objects are arranged in a group. They prefer to choose from a closely arranged group if one unidentified object in that group has a positive quality, but prefer to choose from a group in which objects are farther apart if one unidentified object in that group has a negative quality. We call this pattern of preference the group-contagion effect. We also found that the magnitude of the effect increases if the number of objects possessing the positive or negative quality increases. PMID:19493323

  4. Cycling in the Absence of Task-Related Feedback: Effects on Pacing and Performance

    PubMed Central

    Smits, Benjamin L. M.; Polman, Remco C. J.; Otten, Bert; Pepping, Gert-Jan; Hettinga, Florentina J.

    2016-01-01

    Introduction: To achieve personal goals in exercise task completion, exercisers have to regulate, distribute, and manage their effort. In endurance sports, it has become very commonplace for athletes to consult task-related feedback on external devices to do so. The aim of the present study was to explore the importance of the presence of this information by examining the influence of the absence of commonly available task-related feedback on effort distribution and performance in experienced endurance athletes. Methods: A 20-km cycling time trial was performed. Twenty Participants from a homogenous cyclist population were appointed to a group that did not receive any feedback (NoF), or a group that could consult task-related feedback (i.e., speed, heart rate, power output, cadence, elapsed time, and elapsed distance) continuously during their trial (FF). Results: The distribution of power output (PO) differed between groups. Most evident is the spurt at the end of the trial of FF, which was not incorporated by NoF. Nevertheless, no between-group differences were found in performance time (FF: 28.86 ± 3.68 vs. NoF: 30.95 ± 2.77 min) and mean PO controlled by body mass (FF: 3.61 ± 0.60 vs. NoF: 3.43 ± 0.38 W/kg). Also, no differences in rating of perceived exertion scores were found. Conclusion: The current study provides a first indication that prior knowledge of task demands together with reliance on bodily and environmental information can be sufficient for experienced athletes to come to comparable time trial performances. This questions the necessity of the presence of in-race instantaneous task-related feedback via external devices for maximizing performance. Moreover, it seems that different pacing strategies emerge depending on sources of information available to experienced athletes. PMID:27559318

  5. Effects of reward and punishment on task performance, mood and autonomic nervous function, and the interaction with personality.

    PubMed

    Sakuragi, Sokichi; Sugiyama, Yoshiki

    2009-06-01

    The effects of reward and punishment are different, and there are individual differences in sensitivity to reward and punishment. The purpose of this study was to investigate the effects of reward and punishment on task performance, mood, and autonomic nervous function, along with the interaction with personality. Twenty-one healthy female subjects volunteered for the experiment. The task performance was evaluated by required time and total errors while performing a Wisconsin Card Sorting Test. We assessed their personalities using the Minnesota Multiphasic Personality Inventory (MMPI) questionnaire, and mood states by a profile of mood states. Autonomic nervous function was estimated by a spectral analysis of heart rate variability, baroreflex sensitivity, and blood pressure. Repeated measures analysis of variance (ANOVA) revealed significant interaction of condition x time course on mood and autonomic nervous activity, which would indicate a less stressed state under the rewarding condition, but revealed no significant interaction of condition x time course on the task performance. The interactions with personality were further analyzed by repeated measures ANOVA applying the clinical scales of MMPI as independent variables, and significant interactions of condition x time course x Pt (psychasthenia) on task performance, mood, and blood pressure, were revealed. That is, the high Pt group, whose members tend to be sensitive and prone to worry, showed gradual improvement of task performance under the punishing situation with slight increase in systolic blood pressure, while showed no improvement under the rewarding situation with fatigue sense attenuation. In contrast, the low Pt group, whose members tend to be adaptive and self-confident, showed gradual improvement under the rewarding situation. Therefore, we should carefully choose the strategy of reward or punishment, considering the interaction with personality as well as the context in which it is given. PMID

  6. Effects of Telephone Ring on Two Mental Tasks Relative to AN Office

    NASA Astrophysics Data System (ADS)

    Mouri, K.; Akiyama, K.; Ando, Y.

    2001-03-01

    In many cases, there are a lot of noise sources in an office and particularly, telephone ringing often irritates the office workers. Effects of aircraft noise on the mental work of pupils were reported by Ando et al.[1]. In spite of its serious effect, it has not yet been found how the physical parameters of the wave form influence the perception of noise. The purpose of this study is to investigate the effects of telephone ringing on two mental tasks. This investigation is based on the human auditory-brain model consisting of the auto-correlation function (ACF) of sound source, the interaural cross-correlation function (IACF) for sound signals arriving at the two ears, and the specialization of the cerebral hemispheres. Under the stimulus of a telephone ringing, an adding task and a drawing task were performed. Results show that telephone ringing influences differently the two tasks: the V-type relaxation was observed only during the drawing task. It is revealed that the interference effect between the drawing task and the noise may occur in the right hemisphere.

  7. Effects of task instruction on autobiographical memory specificity in young and older adults.

    PubMed

    Ford, Jaclyn Hennessey; Rubin, David C; Giovanello, Kelly S

    2014-01-01

    Older adults tend to retrieve autobiographical information that is overly general (i.e., not restricted to a single event, termed the overgenerality effect) relative to young adults' specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy ageing, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults' memories might include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being. PMID:23915176

  8. Effects of Task Instruction on Autobiographical Memory Specificity in Young and Older Adults

    PubMed Central

    Ford, Jaclyn Hennessey; Rubin, David C.; Giovanello, Kelly S.

    2013-01-01

    Older adults tend to retrieve autobiographical information that is overly general (i.e. not restricted to a single event, termed the overgenerality effect) relative to young adults’ specific memories. A vast majority of studies that have reported overgenerality effects explicitly instruct participants to retrieve specific memories, thereby requiring participants to maintain task goals, inhibit inappropriate responses, and control their memory search. Since these processes are impaired in healthy aging, it is important to determine whether such task instructions influence the magnitude of the overgenerality effect in older adults. In the current study, participants retrieved autobiographical memories during presentation of musical clips. Task instructions were manipulated to separate age-related differences in the specificity of underlying memory representations from age-related differences in following task instructions. Whereas young adults modulated memory specificity based on task demands, older adults did not. These findings suggest that reported rates of overgenerality in older adults’ memories may include age-related differences in memory representation, as well as differences in task compliance. Such findings provide a better understanding of the underlying cognitive mechanisms involved in age-related changes in autobiographical memory and may also be valuable for future research examining effects of overgeneral memory on general well-being. PMID:23915176

  9. Children's Learning Groups: A Study of Emergent Leadership, Dominance, and Group Effectiveness.

    ERIC Educational Resources Information Center

    Yamaguchi, Ryoko

    This study explores the importance of the group context in the emergence of leadership, dominance, and group effectiveness in children's collaborative learning groups. Ten 3-person work groups performed a collaborative math activity. Using achievement goal orientation (Ames, 1992; Maehr and Midgley, 1996; Pintrich and Schunk, 1996) as a framework,…

  10. The Effects of Planning on Writing Narrative Task Performance with Low and High EFL Proficiency

    ERIC Educational Resources Information Center

    Rahimpour, Massoud; Nariman-Jahan, Roghayyeh

    2011-01-01

    The impetus of the present study was to scrutinize the impact of planning and proficiency on 172 EFL learners' written task performance regarding concept load, fluency, complexity and accuracy. Planning was operationalized at two levels: pretask planning (PTP) and online planning (OLP). Participants of this study were two groups, high and low…

  11. The Effects of Task Instruction Sheets on the Performance of Eleventh Grade Students Studying Vocational Horticulture.

    ERIC Educational Resources Information Center

    Scanlon, Dennis C.; Newcomb, L. H.

    1983-01-01

    In recent years, managing a vocational laboratory has become an increasingly difficult and complex task facing many vocational educators. Specialized instructional areas, diverse groups of students, and extended laboratory time have caused educators to seek alternate ways of providing practical "hands-on" instruction when traditional supervised…

  12. Effects of Elicitation Task Variables on Speech Production by Children with Cochlear Implants

    ERIC Educational Resources Information Center

    McCleary, Elizabeth A.; Ide-Helvie, Dana L.; Lotto, Andrew J.; Carney, Arlene Earley; Higgins, Maureen B.

    2007-01-01

    Given the interest in comparing speech production development in children with normal hearing and hearing impairment, it is important to evaluate how variables within speech elicitation tasks can differentially affect the acoustics of speech production for these groups. In a first experiment, children (6-14 years old) with cochlear implants…

  13. Locus of Control and Task Effects in Mother-Son Interactions.

    ERIC Educational Resources Information Center

    Mead-Fox, Merrill F.; Kralj, Mary M.

    This study examines the interaction of mother-son dyads as a function of mothers' and sons' locus of control and the demand characteristics of specific tasks. The subjects were 32 third grade boys from parochial schools in the District of Columbia area and their mothers. They were assigned to internal or external locus of control groups based on a…

  14. Orthographic influences in spoken word recognition: the consistency effect in semantic and gender categorization tasks.

    PubMed

    Peereman, Ronald; Dufour, Sophie; Burt, Jennifer S

    2009-04-01

    According to current models, spoken word recognition is driven by the phonological properties of the speech signal. However, several studies have suggested that orthographic information also influences recognition in adult listeners. In particular, it has been repeatedly shown that, in the lexical decision task, words that include rimes with inconsistent spellings (e.g., /-ip/ spelled -eap or -eep) are disadvantaged, as compared with words with consistent rime spelling. In the present study, we explored whether the orthographic consistency effect extends to tasks requiring people to process words beyond simple lexical access. Two different tasks were used: semantic and gender categorization. Both tasks produced reliable consistency effects. The data are discussed as suggesting that orthographic codes are activated during word recognition, or that the organization of phonological representations of words is affected by orthography during literacy acquisition. PMID:19293108

  15. Effects of Using an Ipod App to Manage Recreation Tasks

    ERIC Educational Resources Information Center

    Uphold, Nicole M.; Douglas, Karen H.; Loseke, Dannell L.

    2016-01-01

    A withdrawal design study evaluated the effectiveness of using constant time delay to teach six adults with a developmental disability to program and use an iPod touch® as an electronic photographic activity schedule (ePAS). The ePAS, created with the First Then Visual Schedule app, consisted of photographs of different exercises to complete…

  16. Towards Effective Partnerships in a Collaborative Problem-Solving Task

    ERIC Educational Resources Information Center

    Schmitz, Megan J.; Winskel, Heather

    2008-01-01

    Background: Collaborative learning is recognized as an effective learning tool in the classroom. In order to optimize the collaborative learning experience for children within a collaborative partnership, it is important to understand how to match the children by ability level, and whether assigning roles within these dyads is beneficial or not.…

  17. Effect of tDCS on task relevant and irrelevant perceptual learning of complex objects.

    PubMed

    Van Meel, Chayenne; Daniels, Nicky; de Beeck, Hans Op; Baeck, Annelies

    2016-01-01

    During perceptual learning the visual representations in the brain are altered, but these changes' causal role has not yet been fully characterized. We used transcranial direct current stimulation (tDCS) to investigate the role of higher visual regions in lateral occipital cortex (LO) in perceptual learning with complex objects. We also investigated whether object learning is dependent on the relevance of the objects for the learning task. Participants were trained in two tasks: object recognition using a backward masking paradigm and an orientation judgment task. During both tasks, an object with a red line on top of it were presented in each trial. The crucial difference between both tasks was the relevance of the object: the object was relevant for the object recognition task, but not for the orientation judgment task. During training, half of the participants received anodal tDCS stimulation targeted at the lateral occipital cortex (LO). Afterwards, participants were tested on how well they recognized the trained objects, the irrelevant objects presented during the orientation judgment task and a set of completely new objects. Participants stimulated with tDCS during training showed larger improvements of performance compared to participants in the sham condition. No learning effect was found for the objects presented during the orientation judgment task. To conclude, this study suggests a causal role of LO in relevant object learning, but given the rather low spatial resolution of tDCS, more research on the specificity of this effect is needed. Further, mere exposure is not sufficient to train object recognition in our paradigm. PMID:27096945

  18. The Effects of a Secondary Task on Forward and Backward Walking in Parkinson Disease

    PubMed Central

    Hackney, Madeleine E.; Earhart, Gammon M.

    2009-01-01

    Background People with Parkinson disease (PD) often fall while multi-tasking or walking backward, unavoidable activities in daily living. Dual tasks involving cognitive demand during gait and unfamiliar motor skills like backward walking could identify those with fall risk, but dual tasking while walking backward has not been examined in those with PD, those who experience Freezing of Gait (FOG), or healthy older controls. Methods Seventy-eight people with PD (mean age = 65.1±9.5 years, Female: 28%) and 74 age- and sex-matched controls (mean age = 65.0±10.0 years, Female: 23%) participated. A computerized walkway measured gait velocity, stride length, swing and stance percent, cadence, heel to heel base of support, functional ambulation profile, and gait asymmetry during forward and backward walking with and without a secondary cognitive task. Results Direction and task effects on walking performance were similar between healthy controls and those with PD. However, those with PD were more affected than controls, and freezers were more affected than non-freezers, by backward walking and dual tasking. Walking backward seemed to impact gait more than dual tasking in those with PD, although the subset of freezers appeared particularly impacted by both challenges. Conclusion People with PD are impaired while performing complex motor and mental tasks simultaneously, which may put them at risk for falling. Those with FOG are more adversely affected by both motor and mental challenges than those without. Evaluation of backward walking while performing a secondary task might be an effective clinical tool to identify locomotor difficulties. PMID:19675121

  19. Effects of white noise on off-task behavior and academic responding for children with ADHD.

    PubMed

    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 headphones-only (no white noise) control conditions. Little change in academic responding occurred across conditions for all participants. PMID:24114567

  20. Effects of selective dopaminergic compounds on a delay-discounting task.

    PubMed

    Koffarnus, Mikhail N; Newman, Amy H; Grundt, Peter; Rice, Kenner C; Woods, James H

    2011-08-01

    Impulsivity is widely regarded as a multidimensional trait that encompasses two or more distinct patterns of behavior, and dopaminergic systems are implicated in the expression of impulsive behavior in both humans and animal subjects. Impulsive choice, or the tendency to choose rewards associated with relatively little or no delay, has been extensively studied in humans and animal subjects using delay-discounting tasks. Here, delay-discounting procedures were used to assess the effects of receptor-selective dopaminergic agonists, antagonists, and dopamine transporter ligands on choices of immediate versus delayed sucrose pellets. The effects of d-amphetamine, GBR 12909, apomorphine, SKF 81297, sumanirole, pramipexole, ABT-724, SCH 23390, L-741,626, PG01037, and L-745,870 were assessed in 24 Sprague-Dawley rats. The only drugs to affect impulsive choice selectively without altering undelayed choice were the D1-like antagonist, SCH 23390 (0.01 mg/kg), and the D4 partial agonist, ABT-724 (3.2 mg/kg), which both increased impulsive choice. The shared effects of these compounds may be explained by their localization within the prefrontal cortex on different groups of neurons. None of the selective agonists and antagonists tested reduced impulsive choice, so further research is needed to determine if direct dopaminergic agonists or antagonists may be therapeutically useful in the treatment of impulse-control disorders. PMID:21694584

  1. The effect of training and breed group on problem-solving behaviours in dogs.

    PubMed

    Marshall-Pescini, Sarah; Frazzi, Chiara; Valsecchi, Paola

    2016-05-01

    Dogs have become the focus of cognitive studies looking at both their physical and social problem-solving abilities (Bensky et al. in Adv Stud Behav, 45:209-387, 2013), but very little is known about the environmental and inherited factors that may affect these abilities. In the current study, we presented a manipulation task (a puzzle box) and a spatial task (the detour) to 128 dogs belonging to four different breed groups: Herding, Mastiff-like, Working and Retrievers (von Holdt et al. in Nature 464:898-902, 2010). Within each group, we tested highly trained and non-trained dogs. Results showed that trained dogs were faster at obtaining the reward in the detour task. In the manipulation task, trained dogs approached the apparatus sooner in the first familiarization trial, but no effect of breed emerged on this variable. Furthermore, regardless of breed, dogs in the trained group spent proportionally more time interacting with the apparatus and were more likely to succeed in the test trial than dogs in the non-trained group, whereas regardless of training, dogs in the working breed group were more likely to succeed than dogs in the retriever and herding breed groups (but not the mastiff-like group). Finally, trained dogs were less likely to look at a person than non-trained dogs during testing, but dogs in the herding group more likely to do so than dogs in the retriever and working but not the mastiff-like breed groups. Overall, results reveal a strong influence of training experience but less consistent differences between breed groups on different components thought to affect problem solving. PMID:26861484

  2. It's All about Baxter: Task Orientation in the Effective Teaching of Writing

    ERIC Educational Resources Information Center

    Gadd, Murray; Parr, Judy M.

    2016-01-01

    This New Zealand-based study of the classroom practice of nine exemplary teachers of writing to upper primary-age students explored the significance of task orientation as a component of effective teacher instruction and the instructional strategies or actions that effective teachers utilise to promote such. Effectiveness pertains to teachers…

  3. Evaluating the Separate and Combined Effects of Positive and Negative Reinforcement on Task Compliance

    ERIC Educational Resources Information Center

    Bouxsein, Kelly J.; Roane, Henry S.; Harper, Tara

    2011-01-01

    Positive and negative reinforcement are effective for treating escape-maintained destructive behavior. The current study evaluated the separate and combined effects of these contingencies to increase task compliance. Results showed that a combination of positive and negative reinforcement was most effective for increasing compliance. (Contains 1…

  4. Effects of two doses of glucose and a caffeine–glucose combination on cognitive performance and mood during multi-tasking

    PubMed Central

    Scholey, Andrew; Savage, Karen; O'Neill, Barry V; Owen, Lauren; Stough, Con; Priestley, Caroline; Wetherell, Mark

    2014-01-01

    Background This study assessed the effects of two doses of glucose and a caffeine–glucose combination on mood and performance of an ecologically valid, computerised multi-tasking platform. Materials and methods Following a double-blind, placebo-controlled, randomised, parallel-groups design, 150 healthy adults (mean age 34.78 years) consumed drinks containing placebo, 25 g glucose, 60 g glucose or 60 g glucose with 40 mg caffeine. They completed a multi-tasking framework at baseline and then 30 min following drink consumption with mood assessments immediately before and after the multi-tasking framework. Blood glucose and salivary caffeine were co-monitored. Results The caffeine–glucose group had significantly better total multi-tasking scores than the placebo or 60 g glucose groups and were significantly faster at mental arithmetic tasks than either glucose drink group. There were no significant treatment effects on mood. Caffeine and glucose levels confirmed compliance with overnight abstinence/fasting, respectively, and followed the predicted post-drink patterns. Conclusion These data suggest that co-administration of glucose and caffeine allows greater allocation of attentional resources than placebo or glucose alone. At present, we cannot rule out the possibility that the effects are due to caffeine alone Future studies should aim at disentangling caffeine and glucose effects. PMID:25196040

  5. Effectively Engaging Family Groups in Learning Astronomy

    NASA Astrophysics Data System (ADS)

    Noel-Storr, Jacob

    2006-12-01

    Can family astronomy programs be designed that engage entire family groups in learning and not just support the learning of one or two children in the family group? Can parents be trained ‘on the fly’ to engage in leading their children’s science learning? Can children and their parents find roles that allow them to learn together as a group? I will present results from a two new sets of family astronomy programs that work towards getting a “YES!” in reply to all three questions.

  6. A Key Role for Experimental Task Performance: Effects of Math Talent, Gender and Performance on the Neural Correlates of Mental Rotation

    ERIC Educational Resources Information Center

    Hoppe, Christian; Fliessbach, Klaus; Stausberg, Sven; Stojanovic, Jelena; Trautner, Peter; Elger, Christian E.; Weber, Bernd

    2012-01-01

    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…

  7. On interpretation and task selection in studies on the effects of noise on cognitive performance.

    PubMed

    Sörqvist, Patrik

    2014-01-01

    THIS PAPER DISCUSSES TWO THINGS RESEARCHERS SHOULD CONSIDER WHEN SELECTING TASKS FOR COGNITIVE NOISE STUDIES AND INTERPRETING THEIR FINDINGS: (a) The "process impurity" problem and (b) the propensity of sound to capture attention. Theoretical and methodological problems arise when the effects of noise on complex tasks (e.g., reading comprehension) are interpreted as reflecting an impairment of a specific cognitive process/system/skill. One reason for this is that complex tasks are, by definition, process impure (i.e., they involve several, distinct cognitive processes/systems/skills). Another reason is that sound can capture attention. When sound captures attention, the impairment to task scores is caused by an interruption, not by malfunctioning cognitive processes/systems/skills. Selecting more "process pure" tasks (e.g., the Stroop task) is not a solution to these problems. On the contrary, it introduces further problems with generalizability and representativeness. It is argued that cognitive noise researchers should employ representative noise, representative tasks (which are necessarily complex/process impure), and interpret the results on a behavioral level of analysis rather than on a cognitive level of analysis. PMID:25400615

  8. On interpretation and task selection in studies on the effects of noise on cognitive performance

    PubMed Central

    Sörqvist, Patrik

    2014-01-01

    This paper discusses two things researchers should consider when selecting tasks for cognitive noise studies and interpreting their findings: (a) The “process impurity” problem and (b) the propensity of sound to capture attention. Theoretical and methodological problems arise when the effects of noise on complex tasks (e.g., reading comprehension) are interpreted as reflecting an impairment of a specific cognitive process/system/skill. One reason for this is that complex tasks are, by definition, process impure (i.e., they involve several, distinct cognitive processes/systems/skills). Another reason is that sound can capture attention. When sound captures attention, the impairment to task scores is caused by an interruption, not by malfunctioning cognitive processes/systems/skills. Selecting more “process pure” tasks (e.g., the Stroop task) is not a solution to these problems. On the contrary, it introduces further problems with generalizability and representativeness. It is argued that cognitive noise researchers should employ representative noise, representative tasks (which are necessarily complex/process impure), and interpret the results on a behavioral level of analysis rather than on a cognitive level of analysis. PMID:25400615

  9. Effects of aging and tactile stochastic resonance on postural performance and postural control in a sensory conflict task.

    PubMed

    Dettmer, Marius; Pourmoghaddam, Amir; Lee, Beom-Chan; Layne, Charles S

    2015-01-01

    Postural control in certain situations depends on functioning of tactile or proprioceptive receptors and their respective dynamic integration. Loss of sensory functioning can lead to increased risk of falls in challenging postural tasks, especially in older adults. Stochastic resonance, a concept describing better function of systems with addition of optimal levels of noise, has shown to be beneficial for balance performance in certain populations and simple postural tasks. In this study, we tested the effects of aging and a tactile stochastic resonance stimulus (TSRS) on balance of adults in a sensory conflict task. Nineteen older (71-84 years of age) and younger participants (22-29 years of age) stood on a force plate for repeated trials of 20 s duration, while foot sole stimulation was either turned on or off, and the visual surrounding was sway-referenced. Balance performance was evaluated by computing an Equilibrium Score (ES) and anterior-posterior sway path length (APPlength). For postural control evaluation, strategy scores and approximate entropy (ApEn) were computed. Repeated-measures ANOVA, Wilcoxon signed-rank tests, and Mann-Whitney U-tests were conducted for statistical analysis. Our results showed that balance performance differed between older and younger adults as indicated by ES (p = 0.01) and APPlength (0.01), and addition of vibration only improved performance in the older group significantly (p = 0.012). Strategy scores differed between both age groups, whereas vibration only affected the older group (p = 0.025). Our results indicate that aging affects specific postural outcomes and that TSRS is beneficial for older adults in a visual sensory conflict task, but more research is needed to investigate the effectiveness in individuals with more severe balance problems, for example, due to neuropathy. PMID:25884289

  10. Hand and Grasp Selection in a Preferential Reaching Task: The Effects of Object Location, Orientation, and Task Intention

    PubMed Central

    Scharoun, Sara M.; Scanlan, Kelly A.; Bryden, Pamela J.

    2016-01-01

    As numerous movement options are available in reaching and grasping, of particular interest are what factors influence an individual’s choice of action. In the current study a preferential reaching task was used to assess the propensity for right handers to select their preferred hand and grasp a coffee mug by the handle in both independent and joint action object manipulation contexts. Mug location (right-space, midline, and left-space) and handle orientation (toward, away, to left, and to right of the participant) varied in four tasks that differed as a function of intention: (1) pick-up (unimanual, independent); (2) pick-up and pour (bimanual, independent); (3) pick-up and pass (unimanual, joint action); and (4) pick-up, pour and pass (bimanual, joint action). In line with previous reports, a right-hand preference for unimanual tasks was observed. Furthermore, extending existing literature to a preferential reaching task, role differentiation between the hands in bimanual tasks (i.e., preferred hand mobilizing, non-preferred hand stabilizing) was displayed. Finally, right-hand selection was greatest in right space, albeit lower in bimanual tasks compared to what is typically reported in unimanual tasks. Findings are attributed to the desire to maximize biomechanical efficiency in reaching. Grasp postures were also observed to reflect consideration of efficiency. More specifically, within independent object manipulation (pick-up; pick-up and pour) participants only grasped the mug by the handle when it afforded a comfortable posture. Furthermore, in joint action (pick-up and pass; pick-up, pour and pass), the confederate was only offered the handle if the intended action of the confederate was similar or required less effort than that of the participant. Together, findings from the current study add to our knowledge of hand and grasp selection in unimanual and bimanual object manipulation, within the context of both independent and joint action tasks. PMID

  11. THE EFFECTS OF SONIC ENVIRONMENT OF INDIVIDUALIZED INSTRUCTION IN LEARNING DIFFICULT AND EASY TASKS BY HIGH ACHIEVERS.

    ERIC Educational Resources Information Center

    MCCARTHY, EDWARD H.

    THE SIXTH-GRADE STUDENTS OBTAINING THE 80 HIGHEST MEAN SCORES ON THE METROPOLITAN ACHIEVEMENT TEST FORM D WERE RANDOMLY ASSIGNED TO GROUPS OF EASY OR DIFFICULT TASKS WITHIN EACH OF FIVE DECIBEL LEVEL GROUPS. THE LEARNING TASKS WERE TAKEN FROM THE MEANINGFULNESS OF ALL POSSIBLE CVC TRIGRAMS (ARCHER, 1960). THE APPARATUS INCLUDED A TAPE RECORDING OF…

  12. Effect of Peripheral Communication Pace on Attention Allocation in a Dual-Task Situation

    NASA Astrophysics Data System (ADS)

    Gueddana, Sofiane; Roussel, Nicolas

    Peripheral displays allow continuous awareness of information while performing other activities. Monitoring such a display while performing a central task has a cognitive cost that depends on its perceptual salience and the distraction it causes, i.e. the amount of attention it attracts away from the user’s primary action. This paper considers the particular case of peripheral displays for interpersonal communication. It reports on an experiment that studied the effect of peripheral communication pace on subjects’ allocation of attention in a dual-task situation: a snapshot-based peripheral monitoring task where participants need to assess the presence of a remote person, and a central text-correcting task against the clock. Our results show that the addition of the peripheral task caused a drop in the success rate of the central task. As the pace of snapshots increased, success rate decreased on the peripheral task while on the central one, success rate remained the same but failures to reply in time occurred more frequently. These results suggest that the increase in pace of snapshots caused participants to change their strategy for the central task and allocate more attention to the peripheral one, not enough to maintain peripheral performance but also not to the point where it would affect central performance. Overall, our work suggests that peripheral communication pace subtly influences attention allocation in dual-task situations. We conclude by discussing how control over information pace could help users of communication systems to adjust their local distraction as well as the attention they draw from remote users.

  13. Effects of task-oriented robot training on arm function, activity, and quality of life in chronic stroke patients: a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Over fifty percent of stroke patients experience chronic arm hand performance problems, compromising independence in daily life activities and quality of life. Task-oriented training may improve arm hand performance after stroke, whereby augmented therapy may lead to a better treatment outcome. Technology-supported training holds opportunities for increasing training intensity. However, the effects of robot-supported task-oriented training with real life objects in stroke patients are not known to date. The aim of the present study was to investigate the effectiveness and added value of the Haptic Master robot combined with task-oriented arm hand training in chronic stroke patients. Methods In a single-blind randomized controlled trial, 22 chronic stroke patients were randomly allocated to receive either task-oriented robot-assisted arm-hand training (experimental group) or task-oriented non-robotic arm-hand training (control group). For training, the T-TOAT (Technology-supported Task-Oriented Arm Training) method was applied. Training was provided during 8 weeks, 4 times/week, 2× 30 min/day. Results A significant improvement after training on the Action Research Arm Test (ARAT) was demonstrated in the experimental group (p = 0.008). Results were maintained until 6 months after cessation of the training. On the perceived performance measure (Motor Activity Log (MAL)), both, the experimental and control group improved significantly after training (control group p = 0.008; experimental group p = 0.013). The improvements on MAL in both groups were maintained until 6 months after cessation of the training. With regard to quality of life, only in the control group a significant improvement after training was found (EuroQol-5D p = 0.015, SF-36 physical p = 0.01). However, the improvement on SF-36 in the control group was not maintained (p = 0.012). No between-group differences could be demonstrated on any of the outcome measures

  14. Effect of temperature on task performance in officeenvironment

    SciTech Connect

    Seppanen, Olli; Fisk, William J.; Lei, Q.H.

    2006-07-01

    Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with a degree of accuracy dependent on the building and its HVAC system. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance at work. In this study, we focused on the effects of temperature on performance at office work. We included those studies that had used objective indicators of performance that are likely to be relevant in office type work, such as text processing, simple calculations (addition, multiplication), length of telephone customer service time, and total handling time per customer for call-center workers. We excluded data from studies of industrial work performance. We calculated from all studies the percentage of performance change per degree increase in temperature, and statistically analyzed measured work performance with temperature. The results show that performance increases with temperature up to 21-22 C, and decreases with temperature above 23-24 C. The highest productivity is at temperature of around 22 C. For example, at the temperature of 30 C, the performance is only 91.1% of the maximum i.e. the reduction in performance is 8.9%

  15. Effect of loudness on reaction time and response force in different motor tasks.

    PubMed

    Jaśkowski, Piotr; Włodarczyk, Dariusz

    2005-12-01

    Van der Molen and Keuss, in 1979 and 1981, showed that paradoxically long reaction times occur with extremely strong auditory stimuli when the task is difficult, e.g., choice-by-location or Simon paradigm. It was argued that this paradoxical behavior of RT is due to active inhibition of an arousal-dependent bypassing mechanism to prevent false responses. As the peak force, i.e., maximal force exerted by participants on a response key, is considered to be related to immediate arousal, we predicted that for extremely loud stimuli and for difficult tasks, lengthening of RT should be associated with reduction of peak force. Moreover, these effects should be enhanced when emphasis is on accuracy rather than speed. Although the relation between RT and intensity depended on task difficulty, no increase in RT was found for the loudest tones. Moreover, peak force increased monotonically with loudness, showing no tendency to be suppressed for loudest tones and difficult tasks. PMID:16491701

  16. Effects of targets embedded within words in a visual search task

    PubMed Central

    Grabbe, Jeremy W.

    2014-01-01

    Visual search performance can be negatively affected when both targets and distracters share a dimension relevant to the task. This study examined if visual search performance would be influenced by distracters that affect a dimension irrelevant from the task. In Experiment 1 within the letter string of a letter search task, target letters were embedded within a word. Experiment 2 compared targets embedded in words to targets embedded in nonwords. Experiment 3 compared targets embedded in words to a condition in which a word was present in a letter string, but the target letter, although in the letter string, was not embedded within the word. The results showed that visual search performance was negatively affected when a target appeared within a high frequency word. These results suggest that the interaction and effectiveness of distracters is not merely dependent upon common features of the target and distracters, but can be affected by word frequency (a dimension not related to the task demands). PMID:24855497

  17. Effect of acute exercise on cognitive control required during an Eriksen flanker task.

    PubMed

    Davranche, Karen; Hall, Ben; McMorris, Terry

    2009-10-01

    This study aimed to determine how cognitive control, engaged in a task requiring selective inhibition, is affected by acute steady-state exercise. An adapted version of the Eriksen flanker task, involving three types of trials that varied according to their level of congruency (congruent trials, stimulus-incongruent trials, and response-incongruent trials) was performed during 2 periods of 20-min cycling at a carefully controlled intensity (50% of maximal aerobic power). The results indicated that moderate exercise improves reaction time (RT) performance on the Eriksen flanker task. This facilitating effect appeared to be neither dependent on the nature of the interference (stimulus level conflict vs. response level conflict) nor on the amount of cognitive control engaged in the task (congruent vs. incongruent trials). Distributional RT analyses did not highlight any sign of impairment in the efficiency of cognitive control. PMID:20016112

  18. The effects of vocal versus manual response modalities on multi-task performance

    NASA Astrophysics Data System (ADS)

    Griffin, G. R.; Mosko, J. D.

    1985-02-01

    The increasing complexity of display and control instrumentation in modern high performance aircraft has the potential to overload the human operator and result in diminished system performance. Interactive voice technology has been proposed as a method to reduce the high workload placed on the pilots of military aircraft. This report presents the results of an experiment designed to evaluate the effects on human performance of vocal versus manual response modalities on single and multiple tasks simulating some conditions of flight. Results indicated a significant increase in performance precision on a psychomotor task when a vocal, rather than a manual response mode was used on the simultaneous performance of multiple tasks. These results suggest that human performance on visually oriented multiple tasks requiring simultaneous execution may be improved if some of the work effort can be performed using a vocal input/output.

  19. Effects of Physical Practice and Imagery Practice on Bilateral Transfer in Learning a Sequential Tapping Task

    PubMed Central

    Land, William M.; Liu, Binya; Cordova, Alberto; Fang, Ming; Huang, Yufei; Yao, Wan X.

    2016-01-01

    Recent research on bilateral transfer suggests that imagery training can facilitate the transfer of motor skill from a trained limb to that of an untrained limb above and beyond that of physical practice. To further explore this effect, the present study examined the influence of practice duration and task difficulty on the extent to which imagery training and physical training influences bilateral transfer of a sequential key pressing task. In experiment 1, participants trained on the key pressing task using their non-dominant arm under one of three conditions (physical practice, imagery practice, and no practice). In a subsequent bilateral transfer test, participants performed the sequential task using their untrained dominant arm in either an original order or mirror-ordered sequence. In experiment 2, the same procedures were followed as in experiment 1 except that participants trained with their dominant arm and performed the bilateral transfer task with their non-dominant arm. Results indicated that with extended practice beyond what has been employed in previous studies, physical practice is more effective at facilitating bilateral transfer compared to training with imagery. Interestingly, significant bilateral transfer was only observed for transfer from the non-dominant to the dominant arm with no differences observed between performing the task in an original or mirror ordered sequence. Overall, these findings suggest that imagery training may benefit bilateral transfer primarily at the initial stages of learning, but with extended training, physical practice leads to larger influences on transfer. PMID:27050168

  20. Board task performance: An exploration of micro- and macro-level determinants of board effectiveness

    PubMed Central

    Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina; Huse, Morten

    2012-01-01

    This paper addresses recent calls to narrow the micro–macro gap in management research (Bamberger, 2008), by incorporating a macro-level context variable (country) in exploring micro-level determinants of board effectiveness. Following the integrated model proposed by Forbes and Milliken (1999), we identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings influence board tasks, and how the context moderates the relationship between processes and tasks. Our hypotheses are tested on a survey-based dataset of 535 medium-sized and large industrial firms in Italy and Norway, which are considered to substantially differ along legal and cultural dimensions. The findings show that: (i) Board processes have a larger potential than demographic variables to explain board task performance; (ii) board task performance differs significantly between boards operating in different contexts; and (iii) national context moderates the relationships between board processes and board task performance. Copyright © 2010 John Wiley & Sons, Ltd. PMID:23365485