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Sample records for effects task group

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

    ERIC Educational Resources Information Center

    Greenberg, Carl I.; And Others

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

  2. 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.

  3. Effects of task interdependence on the relationship between helping behavior and group performance.

    PubMed

    Bachrach, Daniel G; Powell, Benjamin C; Collins, Brian J; Richey, R Glenn

    2006-11-01

    The authors examine whether task interdependence moderates the relationship between the helping form of organizational citizenship behavior (OCB) and group performance. In a laboratory study, 62 groups with 3 members each completed a card-sequencing activity in which the level of task interdependence among group members was manipulated. Independent evaluators assessed helping by viewing videotapes of the groups' interactions during the sequencing activities. Performance was measured as a combined function of group speed and accuracy. Two prior field studies reported contradictory results regarding the impact of helping on group performance. Results from this study suggest that task interdependence may explain these results, and that the relationship between helping and group performance depends on the level of task interdependence required of group members.

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

    ERIC Educational Resources Information Center

    Kalkhoff, Will

    2005-01-01

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

  6. 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.

  7. 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

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

    PubMed

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

    2014-06-01

    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

  9. Gender, Group Composition, and Task Type in Small Task Groups Using Computer-Mediated Communication.

    ERIC Educational Resources Information Center

    Savicki, Victor; And Others

    1996-01-01

    To investigate gender effects on computer-mediated communication, undergraduate psychology students were put in small groups (males, females, or mixed) and were assigned feminine content (decision making) and masculine content (intellective) task types. Groups of females, regardless of task, sent more words per e-mail message, were more satisfied…

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

    PubMed

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

    2016-06-01

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

  11. 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

  12. Communication Effects on Small Group Decision-Making: Homogeneity and Task as Moderators of the Communication-Performance Relationship.

    ERIC Educational Resources Information Center

    Salazar, Abran J.

    1997-01-01

    Investigates circumstances under which communication variables contribute significantly to the constitution of group decisions. Postulates two variables, homogeneity of task-relevant information possessed by group members and task demonstrability, to moderate the impact of communication and group member ability on quality of group outcomes.…

  13. 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

  14. 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

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

    ERIC Educational Resources Information Center

    Nakanishi, Masayuki

    1988-01-01

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

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

    PubMed

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

    2014-04-01

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

  17. Radiological Protection in Space: Indication from the ICRP Task Group

    NASA Astrophysics Data System (ADS)

    Dietze, Günther

    In 2007 the International Commission on Radiological Protection (ICRP) has established a Task Group (Radiation Protection in Space) dealing with the problems of radiation protection of astronauts in space missions. Its first task is a report on "Assessment of Radiation Exposure of Astronauts in Space". When the ICRP published its general recommendations for radiological protection in 2007 (ICRP Publication 103 following ICRP Publication 60 (1991)) it was obvious that these recommendations do not really consider the special situation of astronauts in space. The radiation field with its high content of charged particles of very high energies strongly differs from usual radiation fields on ground. For example, this has consequences for the assessment of doses in the body of astronauts. The ICRP Task Group has discussed this situation and the presentation will deal with some consequences for the concept of radiation dosimetry and radiological protection in space. This includes e. g. the assessment of organ doses and the application of the effective dose concept with its definition of radiation weighting factors. Radiation quality of high energy heavy ions may be defined different than usually performed on ground. An approach of using the quality factor concept in the definition of an "effective dose" is favored for application in space missions similar to the method proposed in NCRP Report 142. New data calculated on the basis of the reference anthropomorphic voxel phantoms recommended by ICRP support this procedure. Individual dosimetry is a further subject of discussion in the Task Group. While the operational dose equivalent quantities generally in use in radiation protection on ground are not helpful for applications in space, different procedures of the assessment of organ and effective doses are applied. The Task Group is dealing with this situation.

  18. 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,…

  19. Percepts of Tasks and Communication Dispersion Potential in Working Groups.

    ERIC Educational Resources Information Center

    Elkins, David

    The purpose of this study was to examine the relationship between individual group members' concepts of tasks and their tendency to communicate with each other about tasks as related to the groups' abilities to adapt to the demands of a dynamic environment. Data was gathered from five persons in the Audiovisual Support group of the American…

  20. 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…

  1. 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.

  2. 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.

  3. Work Group Performance on Production Operations Management Tasks.

    ERIC Educational Resources Information Center

    Brauchle, Paul E.; Evans, Richard V., Jr.

    1998-01-01

    A class of 71 industrial technology students was divided into either self-selected (homogeneous) work groups or randomly assigned (heterogeneous) groups. The heterogeneous groups had significantly better peer ratings and adjusted scores on their work tasks, but not better raw scores. Despite evidence of higher achievement in random groups,…

  4. Group Task Force on Satellite Rescue and Repair

    NASA Astrophysics Data System (ADS)

    1992-09-01

    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.

  5. 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.

  6. 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…

  7. 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

  8. 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.

  9. 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

  10. 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…

  11. 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.

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

    USGS Publications Warehouse

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

    2012-01-01

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

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

    PubMed

    Kobayashi, Keiichi

    2014-06-01

    This study examined the effect of reading tasks on the integration of content and source information from multiple texts. Undergraduate students (N = 102) read five newspaper articles about a fictitious incident in either a summarization task condition or an evaluation task condition. Then, they performed an integration test and a source choice test, which assessed their understanding of a situation described in the texts and memory for the sources of text information. The results indicated that the summarization and evaluation task groups were not significantly different in situational understanding. However, the summarization task group significantly surpassed the evaluation task group for source memory. No significant correlation between the situational understanding and the source memory was found for the summarization group, whereas a significant positive correlation was found for the evaluation group. The results are discussed in terms of the documents model framework. PMID:25016841

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

    PubMed

    Kobayashi, Keiichi

    2014-06-01

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

  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.

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

    ERIC Educational Resources Information Center

    Karsh, Kathryn G.; Repp, Alan C.

    1992-01-01

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

  18. Indiana University High Energy Physics Group, Task E

    SciTech Connect

    Alyea, E.D. Jr.

    1991-01-01

    This progress report for Task E of the Indiana University High Energy Physics Group covers the period June 1, 1990 to April 15, 1991. All my research effort was devoted to the Large Volume Detector (LVD) at the Gran Sasso Laboratory in Italy. The first of five towers'' of LVD is currently under construction. My primary effort during this time has been to bring to fruition the cabling plans developed by me the previous year. Other activities have included consultations on the design of the tracking trigger electronics, work on several hardware systems for the direct mount tracking modules, and coordination of various projects at the Gran Sasso Lab.

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

    PubMed

    Master, Allison; Walton, Gregory M

    2013-01-01

    Three experiments (N = 130) used a minimal group manipulation to show that just perceived membership in a social group boosts young children's motivation for and learning from group-relevant tasks. In Experiment 1, 4-year-old children assigned to a minimal "puzzles group" persisted longer on a challenging puzzle than children identified as the "puzzles child" or children in a control condition. Experiment 2 showed that this boost in motivation occurred only when the group was associated with the task. In Experiment 3, children assigned to a minimal group associated with word learning learned more words than children assigned an analogous individual identity. The studies demonstrate that fostering shared motivations may be a powerful means by which to shape young children's academic outcomes. PMID:23075286

  20. Task Switching Effects in Anticipation Timing

    ERIC Educational Resources Information Center

    Fairbrother, Jeffrey T.; Brueckner, Sebastian

    2008-01-01

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

  1. 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…

  2. 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…

  3. 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.

  4. Tactile Stimuli Increase Effects of Modality Compatibility in Task Switching.

    PubMed

    Stephan, Denise Nadine; Koch, Iring

    2015-01-01

    Modality compatibility refers to the similarity of stimulus modality and modality of response-related sensory consequences. Previous dual-task studies found increased switch costs for modality incompatible tasks (auditory-manual/visual-vocal) compared to modality compatible tasks (auditory-vocal/visual-manual). The present task-switching study further examined modality compatibility and investigated vibrotactile stimulation as a novel alternative to visual stimulation. Interestingly, a stronger modality compatibility effect on switch costs was revealed for the group with tactile-auditory stimulation compared to the visual-auditory stimulation group. We suggest that the modality compatibility effect is based on crosstalk of central processing codes due to ideomotor "backward" linkages between the anticipated response effects and the stimuli indicating this response. This crosstalk is increased in the tactile-auditory stimulus group compared to the visual-auditory stimulus group due to a higher degree of ideomotor-compatibility in the tactile-manual tasks. Since crosstalk arises between tasks, performance is only affected in task switching and not in single tasks.

  5. 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.

  6. Cognate effects in bilingual language comprehension tasks.

    PubMed

    Yudes, Carolina; Macizo, Pedro; Bajo, Teresa

    2010-05-12

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

  7. Task-specific effects of reward on task switching.

    PubMed

    Umemoto, Akina; Holroyd, Clay B

    2015-07-01

    Although cognitive control and reinforcement learning have been researched extensively over the last few decades, only recently have studies investigated their interrelationship. An important unanswered question concerns how the control system decides what task to execute and how vigorously to carry out the task once selected. Based on a recent theory of control formulated according to principles of hierarchical reinforcement learning, we asked whether rewards can affect top-down control over task performance at the level of task representation. Participants were rewarded for correctly performing only one of two tasks in a standard task-switching experiment. Reaction times and error rates were lower for the reinforced task compared to the non-reinforced task. Moreover, the switch cost in error rates for the non-reinforced task was significantly larger compared to the reinforced task, especially for trials in which the imperative stimulus afforded different responses for the two tasks, resulting in a "non-paradoxical" asymmetric switch cost. These findings suggest that reinforcement at the task level resulted in greater application of top-down control rather than in stronger stimulus-response pathways for the rewarded task.

  8. Indiana University High Energy Physics Group, Task C

    SciTech Connect

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

    1991-01-01

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

  9. Effective Group Dynamics: Theories and Practices.

    ERIC Educational Resources Information Center

    Murk, Peter J.

    Using a brief experiential group activity called "Choosing a Color Exercise" as an introductory measure, this paper explains the basics of group dynamics and reviews the major theoretical relationships between the group's structure, the dynamics of maintenance and task behaviors, and effective individual performances. The types of functional and…

  10. The Effect of Supplementary Small Group Experience on Task Orientation and Cognitive Performance in Kindergarten Children. A Final Report of the Kindergarten 'Learning To Learn' Program Evaluation Project.

    ERIC Educational Resources Information Center

    Lay, Margaret

    A study was done to see if a teacher-guided, sequentially-arranged program of instruction for kindergarten children used in addition to a regular classroom program is more effective in producing general intellectual gains and specified behavioral characteristics than two instructional alternatives. These alternatives were (1) participation in a…

  11. 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.

  12. 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

  13. Exploring the disruptive effects of psychopathy and aggression on group processes and group effectiveness.

    PubMed

    Baysinger, Michael A; Scherer, Kelly T; LeBreton, James M

    2014-01-01

    The present research examines the influence of implicit and explicit personality characteristics on group process and effectiveness. Individuals from 112 groups participated in 2 problem-solving tasks and completed measures of group process and effectiveness. Results indicated that groups characterized by higher levels of psychopathy and implicit aggression tended to have more dysfunctional interactions and negative perceptions of the group. In addition, task participation and negative socioemotional behaviors fully mediated the relationship between group personality traits and group commitment and cohesion, and negative socioemotional behaviors fully mediated the relationship between group personality and performance on both tasks. Implications of antisocial traits for group interactions and performance, as well as for future theory and research, are discussed. PMID:24016207

  14. 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

  15. 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…

  16. 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,…

  17. The Relationship of Group Structure, Task Performance, and Leadership Recognition Among Adult Basic Education Participants.

    ERIC Educational Resources Information Center

    King, Gordon A.

    A study investigated the relationship between group structure and leader recognition and compared task performance with group structure and leader recognition to obtain a better understanding of the adult basic education participant. Fifteen women were randomly assigned to three groups and each given a list of six symbols. Their task was to…

  18. 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

  19. Brief report: Reduced grouping interference in children with ASD: evidence from a Multiple Object Tracking Task.

    PubMed

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

    2014-07-01

    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 grouped to distracters, a manipulation which has a detrimental effect on tracking performance in adults. MOT performance in the ASD group was also affected by grouping, but this effect was significantly reduced. This result highlights how the reduced bias towards more global processing in ASD could influence further stages of cognition by altering the way in which attention selects information for further processing.

  20. 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.

  1. 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.

  2. 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.…

  3. 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…

  4. 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…

  5. Description of a Task Completed by a Small Learning Group.

    ERIC Educational Resources Information Center

    McElhinney, Jim

    Graduate students studying personnel evaluation were each assigned to interview three professionals regarding their experiences with personnel evaluation. Five interview questions, common across the 12 class members, were supplied. In class, students were formed into groups, a chairperson and recorder were selected for each group, and an agenda…

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  7. Effects of Type A Personality and Task Labels (Work vs. Leisure) on Task Preference.

    ERIC Educational Resources Information Center

    Tang, Thomas Li-Ping

    1986-01-01

    Three groups of subjects (Type A, intermediate, and Type B) were presented an identical problem-solving task labeled as work-related or as leisure-oriented and then given free choice of other activities. The subjects' task preference in the free-choice time was examined as a function of Type A personality and task labels. (MT)

  8. Gender Issues in Addictions Research: The Report of the Task Group on Gender-Focused Research.

    ERIC Educational Resources Information Center

    Addiction Research Foundation, Toronto (Ontario).

    The Task Group on Gender-Focused Research was established to raise awareness and interest in gender as a variable in addictions research at the Addiction Research Foundation (ARF) in Ontario (Canada). Recognizing that much of the research on substance abuse has focused on males, the Task Group was charged with providing a basis for the development…

  9. 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…

  10. 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... Administration (NASA) announces a meeting of the Task Group of the NASA Advisory Council (NAC) Science Committee... meeting will take place telephonically and by WebEx. Any interested person may call the USA toll...

  11. 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... Administration (NASA) announces a meeting of the Task Group of the NASA Advisory Council (NAC) Science Committee... meeting will take place telephonically and by WebEx. Any interested person may call the USA toll...

  12. 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.

  13. Group Planning and Task Efficiency with Complex Problems. Final Report.

    ERIC Educational Resources Information Center

    Lawson, E. D.

    One hundred eighty 4-man groups (90 of men and 90 of women) using 3 types of net (All-Channel, Wheel and Circle) under 3 conditions (Planning Period (PP), Rest Period (RP) and Control) were run in a single session with 5 complex problems to determine whether a single 2-minute planning period after solution of the first problem would result in…

  14. 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;…

  15. 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…

  16. 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…

  17. The role of peer groups in male and female adolescents' task values and physical activity.

    PubMed

    Yli-Piipari, Sami; Jaakkola, Timo; Liukkonen, Jarmo; Kiuru, Noona; Watt, Anthony

    2011-02-01

    The purpose of this longitudinal study was to examine the role of peer groups and sex in adolescents' task values and physical activity. The participants were 330 Finnish Grade 6 students (173 girls, 157 boys), who responded to questionnaires that assessed physical education task values during the spring semester (Time 1). Students' physical activity was assessed one year later (Time 2). The results indicated that adolescent peer groups were moderately homogeneous in terms of task values toward physical education and physical activity. Girls' peer groups were more homogeneous than those of boys in regards to utility and attainment values. Furthermore, the results for both girls and boys showed that particularly intrinsic task value typical for the peer group predicted group members' physical activity. The findings highlight the important role of peer group membership as a determinant of future physical activity. PMID:21526593

  18. Accentuate the Positive: Positive Sentiments and Status in Task Groups

    ERIC Educational Resources Information Center

    Bianchi, Alison J.; Lancianese, Donna A.

    2007-01-01

    We explore the capacity of positive sentiments, those enduring affective states one achieves when one likes another, to impact status structures. Do positive sentiments combine with existing aspects of interaction to create status hierarchies and potentially change the social order, or do they moderate the effects of extant structure by dampening…

  19. 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

  20. 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.

  1. 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…

  2. The Effects of Self-Esteem and Task Perception on Goal Setting, Efficacy, and Task Performance.

    ERIC Educational Resources Information Center

    Tang, Thomas Li-Ping; Reynolds, David Bryan

    This study examined the effects of self-esteem and task perception on goal setting, efficacy, and task performance in 52 recreational dart throwers who were members of two dart organizations. Task perception was manipulated by asking each dart thrower to compete against self, a difficult competitor, and an easy competitor on the same dart game.…

  3. 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…

  4. 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…

  5. 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

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

    PubMed

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

    2014-01-01

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

  7. 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.…

  8. 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…

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

    ERIC Educational Resources Information Center

    Brownell, Celia A.; Hartup, Willard W.

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

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

    PubMed

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

    2016-01-01

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

  11. Effect of methylphenidate on enhancement of spatial learning by novel alternated dual task.

    PubMed

    Veetil, Praveen Kottath; Mukkadan, Joseph Kurian

    2011-01-01

    The novel alternated dual task (ADT) arranged rats to learn T-maze spontaneous alternation task and radial arm maze (RAM) task alternatively, and by doing ADT, rats could acquire the tasks more easily than non alternated dual task (NADT) group. Also retention capacity of ADT group was significantly more and ADT help to learn a complex task faster than learning it in isolation from other tasks. In the present study effect of methylphenidate (MPD), a mood elevator, known to enhance learning and memory, on ADT procedure is assessed. Also effect of ADT procedure and MPD on spatial learning and memory are compared. Different groups were assigned by administering MPD (intraperitoneal injection at a dose of 3 mg/kg body weight) during different phases of behavioural experiments, and control groups received saline injection. MPD administration increased both acquisition and retention capacities. The amelioration attained for retention of complex task by ADT procedure, could be achieved by NADT rats only by administration of MPD. The influence of ADT procedure on acquisition and retention of TM and RAM tasks were similar to the effects of MPD, especially for the RAM task. MPD at low dose is found to enhance the learning and memory capacity in rats, than deteriorating it, supporting the use of MPD as a drug to treat attention deficit hyperactive disorder. The recent reports suggesting the effect of MPD only on retention and not on acquisition could not be confirmed, as enhancement for both acquisition and retention was found in this study. PMID:22319900

  12. 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.

  13. 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

  14. 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.

  15. Group Work: How to Use Groups Effectively

    ERIC Educational Resources Information Center

    Burke, Alison

    2011-01-01

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

  16. 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

  17. 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

  18. 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

  19. 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.

  20. 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

  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. 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

  3. 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.

  4. 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…

  5. 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)

  6. 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…

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

    ERIC Educational Resources Information Center

    Van Velsor, Patricia

    2009-01-01

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

  8. 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,…

  9. Report on the activities of the PSN/NASA Task Group

    NASA Technical Reports Server (NTRS)

    Loria, Alberto; Harrison, James K.

    1988-01-01

    Since July '86 the PSN/NASA Task Group for Tether Flight Demonstrations has been working to find applications of tethers in space, the development of which might be of mutual interest to the two agencies. Seven projects have so far been identified and some more will probably be added. A technical evaluation and a managerial plan have been outlined for each.

  10. 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.

  11. 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.

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

    ERIC Educational Resources Information Center

    Sharma, Bal Krishna

    2015-01-01

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

  13. Crossing the virtual boundary: the effect of task-irrelevant environmental cues on task implementation.

    PubMed

    Zhao, Min; Lee, Leonard; Soman, Dilip

    2012-10-01

    Task-oriented activities often involve a certain degree of waiting before the actual activities commence. We suggest that seemingly irrelevant situational cues in the task environment, such as queue guides, area carpets, or the location of another person, can serve as virtual boundaries that divide the task system into two categories: inside the system versus outside the system. Results from two laboratory and two field studies show that in-system individuals (i.e., those who have crossed the virtual boundary demarcated by these cues) are more likely than out-system individuals to adopt an implemental mind-set, as manifested by increased immediacy of action initiation, increased persistence in task-oriented behavior, and increased optimism. Further, these effects are attenuated when people are given sufficient extrinsic incentives to fulfill the task.

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

    PubMed

    Lamers, Martijn J M; Roelofs, Ardi

    2007-11-01

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

  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. 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…

  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. Coaction Effects on a Muscular Endurance Task

    ERIC Educational Resources Information Center

    Martens, Rainer; Landers, Daniel M.

    1969-01-01

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

  19. 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…

  20. 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.

  1. 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.

  2. 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

  3. Report of the Task Group Calculations to ICRP Committee 2, October 14-17, 1980

    SciTech Connect

    Ford, M.R.

    1981-02-01

    This is the third in the series of reports of the Task Group on Dose Calculations to the International Commission on Radiological Protection (ICRP) Committee 2 as constituted for the four-year period 1977-1981. The two previous reports are documented in ORBL/TM-6988 (April 1979) and ORNL/TM-7230 (March 1980), respectively. Since the last meeting of the Committee, the Task Group has completed the computation of annual limit on intake (ALI) and derived air concentration (DAC) values and the corresponding supplemental data for 37 of the 43 elements planned for inclusion in the third and last part of the Committee report. The report entitled Limits for Intakes of Radionuclides by Workers, ICRP Publication 30 is being issued in three parts; and for each part, a supplement will be issued containing photocopied, computer-formatted supplemental data tables. Part 1 and the Supplement to Part 1 were both published in 1979, and the material for Part 2 and the Supplement to Part 2 are at Pergamon Press. Part 3 and Supplement will be ready for publication in 1981. The Task group plans to issue a separate report on radionuclide transformations used in estimating the ALI and DAC values in Publication 30. Preliminary data are being generated for this report, which will be timed to appear soon after the publication of Part 3 and the Supplement to Part 3.

  4. 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.

  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.

  6. 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

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

    PubMed

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

    2014-05-01

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

  8. Differential facilitative effects of glucose administration on Stroop task conditions.

    PubMed

    Brandt, Karen R; Gibson, E Leigh; Rackie, James M

    2013-12-01

    Previous research has demonstrated that glucose administration improves memory performance. These glucose facilitation effects have been most reliably demonstrated in medial temporal lobe tasks with the greatest effects found for cognitively demanding tasks. The aim of the proposed research was to first explore whether such effects might be demonstrated in a frontal lobe task. A second aim was to investigate whether any beneficial effects of glucose may arise more prominently under tasks of increasing cognitive demand. To achieve these aims, the Stroop Task was administered to participants and effects of a drink of glucose (25 g) were compared with an aspartame-sweetened control drink on performance in young adults. Results demonstrated that glucose ingestion significantly reduced RTs in the congruent and incongruent conditions. No effect on error rates was observed. Of most importance was the finding that this glucose facilitative effect was significantly greatest in the most cognitively demanding task, that is, the incongruent condition. The present results support the contention that the glucose facilitation effect is most robust under conditions of enhanced task difficulty and demonstrate that such benefits extend to frontal lobe function.

  9. 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…

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

    ERIC Educational Resources Information Center

    Jiang, Lin; Xu, Xin

    2016-01-01

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

  11. Effects of Perceptual Variations on Number Comparison Tasks.

    ERIC Educational Resources Information Center

    Kingma, Johannes; Loth, Franciska L.

    1984-01-01

    Investigates the performance of 502 children ranging in age from four years to six years, ten months, on two-choice and multiple-choice number comparison tasks, and explores the effects of perceptual manipulations of elements in the multiple-choice tasks. (RH)

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

    ERIC Educational Resources Information Center

    Aronow, Wilbert S.; And Others

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

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

    ERIC Educational Resources Information Center

    Koichu, Boris; Zaslavsky, Orit; Dolev, Lea

    2016-01-01

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

  15. Circadian Effects on Simple Components of Complex Task Performance

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

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

  16. Effects of aging and dual tasking on step adjustments to perturbations in visually cued walking.

    PubMed

    Mazaheri, Masood; Hoogkamer, Wouter; Potocanac, Zrinka; Verschueren, Sabine; Roerdink, Melvyn; Beek, Peter J; Peper, C E; Duysens, Jacques

    2015-12-01

    Making step adjustments is an essential component of walking. However, the ability to make step adjustments may be compromised when the walker's attentional capacity is limited. This study compared the effects of aging and dual tasking on step adjustments in response to stepping-target perturbations during visually cued treadmill walking. Fifteen older adults (69.4 ± 5.0 years; mean ± SD) and fifteen young adults (25.4 ± 3.0 years) walked at a speed of 3 km/h on a treadmill. Both groups performed visually cued step adjustments in response to unpredictable shifts of projected stepping targets in forward (FW), backward (BW) or sideward (SW) directions, at different levels of task difficulty [which increased as the available response distance (ARD) decreased], and with and without dual tasking (auditory Stroop task). In both groups, step adjustments were smaller than required. For FW and BW shifts, older adults undershot more under dual-task conditions. For these shifts, ARD affected the age groups differentially. For SW shifts, larger errors were found for older adults, dual tasking and the most difficult ARD. Stroop task performance did not differ between groups in all conditions. Older adults have more difficulty than young adults to make corrective step adjustments while walking, especially under dual-tasking conditions. Furthermore, they seemed to prioritize the cognitive task over the step adjustment task, a strategy that may pose aging populations at a greater fall risk. For comparable task difficulty, the older adults performed considerably worse than the young adults, indicating a decreased ability to adjust steps under time pressure.

  17. Effects of aging and dual tasking on step adjustments to perturbations in visually cued walking.

    PubMed

    Mazaheri, Masood; Hoogkamer, Wouter; Potocanac, Zrinka; Verschueren, Sabine; Roerdink, Melvyn; Beek, Peter J; Peper, C E; Duysens, Jacques

    2015-12-01

    Making step adjustments is an essential component of walking. However, the ability to make step adjustments may be compromised when the walker's attentional capacity is limited. This study compared the effects of aging and dual tasking on step adjustments in response to stepping-target perturbations during visually cued treadmill walking. Fifteen older adults (69.4 ± 5.0 years; mean ± SD) and fifteen young adults (25.4 ± 3.0 years) walked at a speed of 3 km/h on a treadmill. Both groups performed visually cued step adjustments in response to unpredictable shifts of projected stepping targets in forward (FW), backward (BW) or sideward (SW) directions, at different levels of task difficulty [which increased as the available response distance (ARD) decreased], and with and without dual tasking (auditory Stroop task). In both groups, step adjustments were smaller than required. For FW and BW shifts, older adults undershot more under dual-task conditions. For these shifts, ARD affected the age groups differentially. For SW shifts, larger errors were found for older adults, dual tasking and the most difficult ARD. Stroop task performance did not differ between groups in all conditions. Older adults have more difficulty than young adults to make corrective step adjustments while walking, especially under dual-tasking conditions. Furthermore, they seemed to prioritize the cognitive task over the step adjustment task, a strategy that may pose aging populations at a greater fall risk. For comparable task difficulty, the older adults performed considerably worse than the young adults, indicating a decreased ability to adjust steps under time pressure. PMID:26298043

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

    PubMed

    Chetail, Fabienne; Quémart, Pauline

    2014-01-01

    According to a recent hypothesis, the organization of letters into groups of successive consonants and vowels (i.e., CV pattern) constrains the orthographic structure of words. Here, we examined to what extent the morphological structure of words modifies the influence of the CV pattern in a syllable counting task. Participants were presented with written words matched for the number of syllables and comprising either one vowel cluster less than the number of syllables (hiatus words, e.g., création) or the same number of vowel clusters (control words, e.g., crépiter). Participants were slower and less accurate for hiatus than control stimuli, be it words (Experiments 1, 3) or pseudowords (Experiment 2). More importantly, this hiatus effect was present even when the stimuli had a morphemic boundary falling within the hiatus (e.g., ré-agir). The results suggest that the CV pattern of items more strongly influences performance in the syllable counting task than the morphological structure. PMID:25270561

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

    PubMed

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

    2003-06-01

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

  20. 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

  1. 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

  2. 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.

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

    PubMed

    Liberatore, Jennica S; Luyben, Paul D

    2009-01-01

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

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

    PubMed

    Liberatore, Jennica S; Luyben, Paul D

    2009-01-01

    The purpose of this study was to investigate the effects of feedback on the on-task behavior of adolescent members of a dance company in central New York. The intervention consisted of immediate group and delayed individual feedback. We used a single-subject reversal design. We hypothesized that implementation of the feedback conditions would increase overall on-task rates and decrease variability relative to baseline rates. The data supported this hypothesis with increased on-task rates and decreased variability when the intervention was in effect. PMID:19629831

  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. 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

  7. 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…

  8. 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.

  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. Age and gender diversity as determinants of performance and health in a public organization: the role of task complexity and group size.

    PubMed

    Wegge, Jürgen; Roth, Carla; Neubach, Barbara; Schmidt, Klaus-Helmut; Kanfer, Ruth

    2008-11-01

    The influence of age and gender composition on group performance and self-reported health disorders was examined with data from 4,538 federal tax employees working in 222 natural work unit groups. As hypothesized, age diversity correlated positively with performance only in groups solving complex decision-making tasks, and this finding was replicated when analyzing performance data collected 1 year later. Age diversity was also positively correlated with health disorders--but only in groups working on routine decision-making tasks. Gender composition also had a significant effect on group performance, such that groups with a high proportion of female employees performed worse and reported more health disorders than did gender-diverse teams. As expected, effects of gender composition were most pronounced in large groups. Effects of age diversity were found when controlling for gender diversity and vice versa. Thus, age and gender diversity seem to play a unique role in performance and well-being. The moderating role of task complexity for both effects of age diversity and the moderating role of group size for both effects of gender diversity further suggest that the impact of these 2 variables depends on different group processes (e.g., knowledge exchange, variation in gender salience).

  12. 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…

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

    PubMed

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

    2016-01-01

    In a number of studies in which a dual-task gait paradigm was used, researchers reported a relationship between cognitive function and gait. However, it is not clear to what extent these effects are dependent on the type of cognitive and walking tasks used in the dual-task paradigm. This study examined whether stride-time variability (STV) and trunk range of motion (RoM) are affected by the type of cognitive task and walking speed used during dual-task gait. Participants walked at both their preferred walking speed and at 25% of their preferred walking speed and performed a serial subtraction and a working memory task at both speeds. Although both tasks significantly reduced STV at both walking speeds, there was no difference between the two tasks. Trunk RoM was affected by the walking speed and type of cognitive task used during dual-task gait: Mediolateral trunk RoM was increased at the slow walking speed, and anterior-posterior trunk RoM was higher only when performing the serial subtraction task at the slow walking speed. The reduction of STV, regardless of cognitive-task type, suggests that healthy adults may redirect cognitive processes away from gait toward cognitive-task performance during dual-task gait. PMID:25823560

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

    PubMed

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

    2014-06-11

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

  15. 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…

  16. An Investigation of Response and Stimulus Modality Transfer Effects after Dual-Task Training in Younger and Older

    PubMed Central

    Lussier, Maxime; Gagnon, Christine; Bherer, Louis

    2012-01-01

    It has been shown that dual-task training leads to significant improvement in dual-task performance in younger and older adults. However, the extent to which training benefits to untrained tasks requires further investigation. The present study assessed (a) whether dual-task training leads to cross-modality transfer in untrained tasks using new stimuli and/or motor responses modalities, (b) whether transfer effects are related to improved ability to prepare and maintain multiple task-set and/or enhanced response coordination, (c) whether there are age-related differences in transfer effects. Twenty-three younger and 23 older adults were randomly assigned to dual-task training or control conditions. All participants were assessed before and after training on three dual-task transfer conditions; (1) stimulus modality transfer (2) response modality transfer (3) stimulus and response modalities transfer task. Training group showed larger improvement than the control group in the three transfer dual-task conditions, which suggests that training leads to more than specific learning of stimuli/response associations. Attentional costs analyses showed that training led to improved dual-task cost, only in conditions that involved new stimuli or response modalities, but not both. Moreover, training did not lead to a reduced task-set cost in the transfer conditions, which suggests some limitations in transfer effects that can be expected. Overall, the present study supports the notion that cognitive plasticity for attentional control is preserved in late adulthood. PMID:22629239

  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 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

  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. 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

  2. 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.

  3. 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.

  4. Effects of simple HMD operations on primary visual tasks

    NASA Astrophysics Data System (ADS)

    McIntire, John; Havig, Paul; Reis, George

    2007-04-01

    Helmet-mounted displays (HMDs) offer the distinct advantage of wearable computing while accomplishing a variety of physical tasks, such as piloting an aircraft, navigating difficult or unfamiliar terrain, performing surgery, etc. However, problems can arise involving the HMD eyepieces, such that they may either block portions of the far visual field, draw attention away from it, or both. In the present experiments, placement of a monocular HMD eyepiece in the visual field was manipulated to examine its effects on dynamic visual search performance in the far-field environment. In Experiment 1, a pre-attentive task was presented on the HMD to investigate possible dual-task decrements. In Experiment 2, either an endogenous (arrow) or exogenous (circle) cue was presented on the HMD to guide visual search to the location of the target. The results from Experiment 1 show that only one of three participants was able to perform the pre-attentive task on the HMD without harming primary task performance and that for only this participant, eyepiece placement altered dual-task performance. The results from Experiment 2 show that both endogenous and exogenous visual search cues were effective at reducing response times in both eyepiece positions.

  5. 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.

  6. Task-Specific Effect of Transcranial Direct Current Stimulation on Motor Learning

    PubMed Central

    Saucedo Marquez, Cinthia Maria; Zhang, Xue; Swinnen, Stephan Patrick; Meesen, Raf; Wenderoth, Nicole

    2013-01-01

    Transcranial direct current stimulation (tDCS) is a relatively new non-invasive brain stimulation technique that modulates neural processes. When applied to the human primary motor cortex (M1), tDCS has beneficial effects on motor skill learning and consolidation in healthy controls and in patients. However, it remains unclear whether tDCS improves motor learning in a general manner or whether these effects depend on which motor task is acquired. Here we compare whether the effect of tDCS differs when the same individual acquires (1) a Sequential Finger Tapping Task (SEQTAP) and (2) a Visual Isometric Pinch Force Task (FORCE). Both tasks have been shown to be sensitive to tDCS applied over M1, however, the underlying processes mediating learning and memory formation might benefit differently from anodal transcranial direct current stimulation (anodal-tDCS). Thirty healthy subjects were randomly assigned to an anodal-tDCS group or sham-group. Using a double-blind, sham-controlled cross-over design, tDCS was applied over M1 while subjects acquired each of the motor tasks over three consecutive days, with the order being randomized across subjects. We found that anodal-tDCS affected each task differently: the SEQTAP task benefited from anodal-tDCS during learning, whereas the FORCE task showed improvements only at retention. These findings suggest that anodal-tDCS applied over M1 appears to have a task-dependent effect on learning and memory formation. PMID:23847505

  7. 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.

  8. Effect of complexity of a physical task on estimation of time to complete.

    PubMed

    Druyan, S; Dani, A; Hadadi, G

    1995-12-01

    Two studies were performed to examine the effect of the complexity of a physical task on the estimation of the time required for its performance. Different paradigms for the estimation of time (prospective vs retrospective) were used with different methods of estimation (reproduction vs verbal estimation). In Study 1, 32 pairs of adults were asked to throw a ball to each other in different ways. The two groups were distinguished by the motor and cognitive changes required in moving from one task to the next. One group had to perform 10 successive repetitions on each of five kinds of ball throws, while the other had to perform the same number of ball throws but with each type being split into two different successive sets of throws so here the task consisted of changes. In Study 2, 60 children (aged 7 or 8 yr.) were asked to perform a set of basketball tasks. The two groups were distinguished by the pace at which they had to perform the task, slowly or rapidly. The results of the two studies indicated a negative relation between the complexity of the task and the group's estimation of time. The reproductive method yielded shorter estimations than the verbal method. The results indicate that for physical activity the attentional model may well be valid.

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

    PubMed

    Nadarevic, Lena; Erdfelder, Edgar

    2014-01-01

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

  10. 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.

  11. 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…

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

    PubMed Central

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

    2016-01-01

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

  13. [Effects of different explanations for performance on a learned helplessness task in undergraduates].

    PubMed

    Araki, Y

    2000-02-01

    Two groups of undergraduates were asked to solve anagrams and arithmetic problems. All the anagrams were solvable but part of the arithmetic problems was insolvable. After the preliminary task, one of the two explanations was given; internal attribution participants (Internal group, N = 22) were told that their failure was due to their problem-solving ability, while external attribution participants (External group, N = 21) were told that they failed because some of the problems had no solution. After the explanations, the groups worked on another set of solvable problems. The test task performance of internal group was significantly lower than that of External group (p = .05), and it was significantly lower than the group's preliminary task (p < .01). No deterioration effect was found for External group. These results supported the implications of the reformulated learned helplessness theory by Abramson, Seligman, and Teasdale (1978). In addition, relationships between performance and participants' attitude such as attributional style and optimism were examined with measurement before and after the task, but no significant correlation was found. PMID:10793462

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

    ERIC Educational Resources Information Center

    Papagno, C.; Caporali, A.

    2007-01-01

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

  15. ERP analyses of task effects on semantic processing from words.

    PubMed

    Marí-Beffa, Paloma; Valdés, Berenice; Cullen, Doug J D; Catena, Andrés; Houghton, George

    2005-05-01

    Semantic (positive) priming refers to the facilitated processing of a probe word when preceded by a related prime word, and is a widely used technique for investigating semantic activation. However, the effect is interrupted or eliminated when attention is directed to low-level features of the prime word, such as its letters, a result which has been used to question the automaticity of semantic processing. We investigated this issue using both behavioural [reaction time (RT)] and electrophysiological measures [event-related potentials (ERPs)]. Subjects performed semantic categorization (living vs. nonliving) and letter search ("A" or "E") tasks on prime words followed by lexical decision on the probe. RT results showed the expected elimination of semantic priming following letter search. However, both prime tasks were affected by the semantic category of the prime, indicating that the meaning was processed. The ERP results supported this conclusion: an early component previously associated with automatic semantic processing [the Recognition Potential (RP)] was sensitive to the category of the prime word irrespective of the prime task. However, a later component (N400) was significantly affected by the task, in both the prime (categorization task) and probe words (semantic priming). The results dissociate rapid, automatic semantic processing from semantic priming. We suggest that a later inhibitory control mechanism suppresses this semantic activation when it is not relevant to the task, and that this produces the loss of semantic priming. PMID:15820637

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

    PubMed

    Ikeda, Hiroshi; Furukawa, Hisataka

    2015-04-01

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

  17. Language experience and right hemisphere tasks: the effects of scanning habits and multilingualism.

    PubMed

    Eviatar, Z

    1997-06-01

    This study explores the effects of multilingualism and reading scanning habits on right hemisphere (RH) abilities. Native Hebrew speakers and Arabic-Hebrew bilinguals performed three tasks. Experiment 1 employed an odd/even decision paradigm on lateralized displays of bar graphs. Both groups of subjects displayed the expected LVFA within the range previously reported for readers of English. Experiment 2 consisted of a chair identification task designed to tap asymmetry of hemispheric arousal and a chimeric face task designed to tap RH specialization for facial emotion. Neither scanning habits nor language experience affected performance on the chair task. Scanning habits seem to have affected performance on the chimeric faces task: there was no preference for the left smile in these right-to-left readers, as opposed to previous results in the literature using left-to-right readers. Correlations between measures from the three tasks and all the subject's scores on an English proficiency test and on a Hebrew test for the bilinguals reveal tentative relationships between proficiency in a second language and RH abilities. The results do not support the hypothesis that multilingualism can affect the manner in which these nonlanguage tasks are subserved by the RH. They do support the hypothesis that scanning habits particular to specific languages can affect performance asymmetries on some nonlanguage tasks that have been posited to reflect RH specialization.

  18. Differential outcome effects in Pavlovian biconditional and ambiguous occasion setting tasks

    PubMed Central

    Delamater, Andrew R.; Kranjec, Alexander; Fein, Matthew I.

    2010-01-01

    Three experiments with rats explored the differential outcome effect (DOE) using a Pavlovian magazine approach conditioning preparation. Experiment 1 compared groups trained on a biconditional discrimination (AX+, AY−, BX−, BY+) with differential or nondifferential outcomes, and Experiment 2 examined this using an ambiguous occasion setting task (e.g., AX+, X−, Y+, AY−). In both experiments subjects trained with differential outcomes learned the tasks better than subjects trained with nondifferential outcomes. Furthermore, subjects given differential outcome training learned the positive occasion setting component of the ambiguous task more efficiently than the negative occasion setting component although both were enhanced by differential outcome training. Experiment 3 demonstrated that the ambiguous occasion setting task was reversed more readily when the target-outcome relations (as opposed to the modulator-outcome relations) were maintained during the reversal phase. These data suggest that an acquired distinctiveness effect may be responsible for the DOE in Pavlovian learning. PMID:20718549

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  20. 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

  1. 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

  2. Effect of task complexity on mental performance during immersion hypothermia.

    PubMed

    Giesbrecht, G G; Arnett, J L; Vela, E; Bristow, G K

    1993-03-01

    The effect of task complexity on the decrement in mental performance during immersion hypothermia was studied. Psychometric tests of varying length and complexity were administered: 1) prior to cold water immersion (baseline); 2) soon after immersion to the neck in cold (8 degrees C) water but prior to any decrease in core temperature; and 3) after 55 to 80 min of immersion when core temperature had decreased 2-4 degrees C. Results indicated that tests placing relatively minimal cognitive demands on individuals, such as auditory attention, the Benton visual recognition test and forward digit span, were unaffected by either initial cold water immersion or central cooling. On the other hand, tests requiring relatively greater mental manipulation and short term memory (i.e., backward digit span) or processing and analysis (i.e., Stroop test) showed a slight improvement upon cold water immersion (perhaps related to increased arousal and/or learning) but a significant decrement following central cooling of 2-4 degrees C. Thus, relatively simple tasks were unaffected by central cooling, whereas more complex tasks were adversely affected. Cold water immersion itself did not interfere with performance of any tasks. Central nervous system cooling probably interferes with mental processing although discomfort and/or the physiological and physical effects of cold on the neuromuscular aspects of speech, required for responses to some of the tasks, may also affect performance.

  3. Effects of Workgroup Structure and Size on Student Productivity during Collaborative Work on Complex Tasks.

    ERIC Educational Resources Information Center

    Fuchs, Lynn S.; Fuchs, Douglas; Kazdan, Sarah A.; Karns, Kathy; Calhoon, Mary Beth; Hamlett, Carol L.; Hewlitt, Sally E.

    2000-01-01

    Examined effects of workgroup size and structure during collaborative work on complex tasks. Found that dyads produced greater collaboration for low-achievers, whereas small groups generated more cognitive conflict among other students. Productivity did not differ as a function of background structure. Findings posed implications for optimizing…

  4. 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…

  5. 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…

  6. Effects of Embedded Processing Tasks on Learning Outcomes.

    ERIC Educational Resources Information Center

    Hobbs, D. J.

    1987-01-01

    Describes a British study with undergraduate accountancy students which compared the quantitative and qualitative effects of three types of embedded tasks or questions--relational-semantic, transpose-semantic, and non-semantic--on learning outcomes. Variables investigated included mathematical background, recall, and comprehension. Relevance of…

  7. Learner Interaction Using Email: The Effects of Task Modification

    ERIC Educational Resources Information Center

    Knight, Paul

    2005-01-01

    This paper outlines the findings of a research project studying the effects of task modification on learner interaction when using email. Taking as its starting point interactionalist theories of SLA, it argues that if those interactional features characteristic of negotiation of meaning which have been identified as promoting SLA are to be…

  8. The Effects of Metacognitive Instruction on Solving Mathematical Authentic Tasks.

    ERIC Educational Resources Information Center

    Kramarski, Bracha; Mevarech, Zemira R.; Arami, Marsel

    2002-01-01

    Investigates the differential effects of cooperative learning with or without metacognitive instruction on lower and higher achievers' solutions of mathematical authentic tasks. Results indicate that students exposed to metacognitive instruction within cooperative learning (COOP+META) significantly outperformed their counterparts exposed to…

  9. 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…

  10. 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…

  11. 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…

  12. 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.

  13. 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

  14. 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

  15. Distinguishing bias from sensitivity effects in multialternative detection tasks.

    PubMed

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

    2014-08-21

    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.

  16. 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.

  17. 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…

  18. Effects on sustained performance of time-sharing a three-phase code transformation task /3P-COTRAN/.

    NASA Technical Reports Server (NTRS)

    Alluisi, E. A.; Morgan, B. B., Jr.

    1971-01-01

    A group of 20 highly trained subjects were divided randomly into five equal groups to time-share the 3P-COTRAN task with a different task combination of a multitask performance battery (MTPB) used by Alluisi (1969). The effects of the time-sharing on the 3P-COTRAN performance and the effects of 3P-COTRAN on the time-shared MTPB performances are analyzed.

  19. 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…

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

    ERIC Educational Resources Information Center

    Mann, Karen V.; Sullivan, Patricia L.

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

  1. Radiation dosimetry in digital breast tomosynthesis: report of AAPM Tomosynthesis Subcommittee Task Group 223.

    PubMed

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

    2014-09-01

    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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. The other-race effect in perception and recognition: insights from the complete composite task.

    PubMed

    Horry, Ruth; Cheong, Winnee; Brewer, Neil

    2015-04-01

    People are more accurate at recognizing faces of their own race than faces from other races, a phenomenon known as the other-race effect. Other-race effects have also been reported in some perceptual tasks. Across 3 experiments, White and Chinese participants completed recognition tests as well as the complete paradigm of the composite task, which measures participants' abilities to selectively attend to the target region of a face while ignoring the task-irrelevant region of the face. Each task was completed with both own- and other-race faces. At a group level, participants showed significant own-race effects in recognition, but not in the composite task. At an individual difference level, the results provided no support for the hypothesis that a deficit in holistic processing for other-race faces drives the other-race effect in recognition. We therefore conclude that the other-race effect in recognition is not driven by the processes that underpin the composite effect.

  9. Collaborative Writing Tasks in the L2 Classroom: Comparing Group, Pair, and Individual Work

    ERIC Educational Resources Information Center

    Dobao, Ana Fernandez

    2012-01-01

    This study investigates the benefits of collaborative writing tasks. Previous research from the perspective of the sociocultural theory of mind suggests that writing tasks completed in pairs offer learners an opportunity to collaborate in the solution of their language-related problems, co-construct new language knowledge, and produce…

  10. 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

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

    PubMed

    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.

  12. 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

  13. 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…

  14. 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…

  15. 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…

  16. 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.

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

    PubMed

    Kaushanskaya, Margarita; Gross, Megan; Buac, Milijana

    2014-07-01

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

  18. Effects of assembling virtual fixtures on learning a navigation task.

    PubMed

    Zheng, Bin; Kuang, Alex; Henigman, Frank; Payandeh, Shahram; Lomax, Alan; Swanström, Lee; Mackenzie, Christine L

    2006-01-01

    An approach to enhance navigation task performance is to integrate sensory guidance (virtual fixtures) into a virtual training system. To evaluate the effects of adding virtual fixtures to skill acquisition, 32 subjects were required to use a PHANToM input device, to transport a virtual object through a computer generated 3-D graphic maze. Subjects practiced navigation under 4 conditions: the maze was augmented with either a graphic fixture (G), attractive force field (F), both graphic and force field (GF), or no (N) virtual fixture. Fifteen practice trials were given before subjects were transferred to a situation with no virtual fixtures. Results showed that the implementation of the force field assisted task performance during practice; however, it failed to show positive transfer effects. In contrast, adding a graphic fixture to the virtual maze helped subjects to define the optimal pathway throughout navigation, which facilitated skill acquisition.

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

    ERIC Educational Resources Information Center

    Milanese, Nadia; Iani, Cristina; Rubichi, Sandro

    2010-01-01

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

  20. 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

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

    PubMed

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

    2014-03-01

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

  2. 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.

  3. 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

  4. 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.

  5. Effect of spatial distance to the task stimulus on task-irrelevant perceptual learning of static Gabors.

    PubMed

    Nishina, Shigeaki; Seitz, Aaron R; Kawato, Mitsuo; Watanabe, Takeo

    2007-10-12

    It was previously shown that sensitivity improvements to a task-irrelevant motion direction can be obtained when it is presented in concurrence with observers' performance of an attended task (A. R. Seitz & T. Watanabe, 2003; T. Watanabe, J. E. Náñez, & Y. Sasaki, 2001). To test whether this task-irrelevant perceptual learning (TIPL) is specific for motion and to clarify the relationships between the observer's task and the resultant TIPL, we investigated the spatial profile of the sensitivity enhancement for a static task-irrelevant feature. During the training period, participants performed an attentionally demanding character identification task at one location, whereas subthreshold, static, Gabor patches, which were masked in noise, were presented at different locations in the visual field. Subjects' sensitivity to the Gabors was compared between the pre- and posttraining tests. First, we found that TIPL extends to learning of static visual stimuli. Thus, TIPL is not a specialized process to motion stimuli. As to the effect of spatial location, the largest improvement was found for the Gabors presented in closest proximity to the task. These data indicate that the learning of the task-irrelevant visual feature significantly depends on the task location, with a gradual attenuation according to the spatial distance between them. These findings give further insights into the mechanism of perceptual learning.

  6. Order effects in contingency learning: the role of task complexity.

    PubMed

    Marsh, Jessecae K; Ahn, Woo-Kyoung

    2006-04-01

    Dennis and Ahn (2001) found that during contingency learning, initial evidence influences causal judgments more than does later evidence (a primacy effect), whereas López, Shanks, Almaraz, and Fernández (1998) found the opposite (a recency effect). We propose that in contingency learning, people use initial evidence to develop an anchoring hypothesis that tends to be underadjusted by later evidence, resulting in a primacy effect. Thus, factors interfering with initial hypothesis development, such as simultaneously learning too many contingencies, as in López et al., would reduce the primacy effect. Experiment 1 showed a primacy effect with learning contingencies involving only one outcome but no primacy effect with two outcomes. Experiment 2 demonstrated that the magnitude of the primacy effect correlated with participants' verbal working memory capacity. It is concluded that a critical moderator for exhibition of the primacy effect is task complexity, presumably because it interferes with initial hypothesis development.

  7. 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

  8. The effect of varying task difficulty on subjective workload

    NASA Technical Reports Server (NTRS)

    Yeh, Y.-Y.; Wickens, C. D.; Hart, S. G.

    1985-01-01

    The effect of different difficulty distribution patterns on subjective workload, and the presence of a primacy/recency effect in subjective ratings are examined. Eight subjects performed the perceptual central processing required for response selection and manual target acquisition for response execution. The reaction time, movement time, and the percent of correct pattern matching and arithmetic equations are analyzed. The data reveal that subjective rating is unaffected by different task difficulty and no primacy/recency effects are observed in subjective ratings. It is concluded that subjective workload reflects the experience of an ongoing integration process.

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

    PubMed Central

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

    2001-01-01

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

  11. 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

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

    PubMed

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

    2001-01-01

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

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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…

  18. 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.

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

    PubMed Central

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

    2015-01-01

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

  20. 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…

  1. 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…

  2. 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.

  3. 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

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

    PubMed

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

    2016-07-01

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

  5. 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

  6. 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

  7. Effect of identity in the multiletter matching task.

    PubMed

    Taylor, D A

    1976-08-01

    This study was concerned with the nature of the character-comparison process involved in same-different judgments of arrays of letters. One condition replicated the standard matching task, with subjects pressing one key to indicate that the two arrays of letters were identical in all positions, and another key to indicate difference in one or more positions. A second condition reversed the standard decision rule and required the subjects to distinguish between arrays that differed in every position from those that matched in one or more positions. Reaction times were shorter to identical arrays in both conditions, indicating that identity effects observed in this and previous studies must be attributed to identity per se and not to decision or response factors. Mathematical analysis of the data revealed that, although a serial self-terminating model could be modified to give a good description of processing in this task, a model based on parallel processing was able to provide a better account both quantitatively and qualitatively. The analysis also indicated that subjects reduced their average reaction times by terminating the comparison process prematurely on some trials, and this guessing strategy was shown to have important implications for the shapes of the reaction time functions observed in this task.

  8. The effect of horizontal versus vertical task presentation on children's performance in coordinate tasks.

    PubMed

    Worsfold, Naomi; Davis, Alyson; De Bruyn, Bart

    2008-01-01

    Empirical work on children's ability to understand spatial coordinates has focused on the factors that increase children's proficiency. When interpreting performance, it should be considered that presenting a coordinate task on a horizontal surface might constrain the responses that children make because some target positions are further away from the child than others. Vertical task presentation removes this constraint. Children aged 3 to 9 years were presented with an interpretative coordinate task administered on a touchscreen, presented in an egocentric-vertical position or egocentric-horizontal position. The results show that for 5- to 7-year-old children vertical presentation led to far more correct responses than horizontal presentation. Analysis of the children's errors suggests that this may be due to the fact that vertical presentation suppresses children's bias towards responding in relation to one rather than both coordinates. Taken together these findings contribute to understanding why children's performance in xy coordination tasks is highly contextually sensitive.

  9. 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.

  10. To group or not to group: an ecological consideration of the stroop effect.

    PubMed

    Reynolds, Michael; Kwan, Donna; Smilek, Daniel

    2010-01-01

    Eight experiments are reported that examine the contextual factors that influence the magnitude of color-word interference in the Stroop task. In Part 1 of the paper (Experiments 1-4) we varied letter-letter grouping using Gestalt principles of proximity and similarity. In Part 2 of the paper (Experiments 5-8) we varied word-color grouping using the Gestalt principles of similarity and common fate. The magnitude of the Stroop effect was strongly influenced by changes in both letter-letter grouping in the color-word and word-color grouping. Overall, the results suggest two ways in which perceptual organization influences the magnitude of Stroop color-word interference and more generally, that there are systematic principles that govern the impact of visually presented words across a variety of laboratory contexts and the real world.

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

    PubMed

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

    2010-11-01

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

  12. The effect of dividing attention between walking and auxiliary tasks in people with Parkinson's disease.

    PubMed

    Fok, Pamela; Farrell, Michael; McMeeken, Joan

    2012-02-01

    This controlled study examined the effects of dividing attention between walking and the performance of a secondary cognitive task in people with mild to moderate Parkinson's disease (Hoehn and Yahr stages 2-3.5). Participants in the training group (n=6) received 30 min divided attention training in taking big steps while simultaneously performing serial three subtractions. Participants in the control group (n=6) received no training. Stride length, gait velocity and accurate enumeration rate were measured at baseline, immediate after training and 30 min after training under single-task (walk only or subtract only) and dual-task (walk and subtract) conditions. Data were also collected at training in the training group. Immediate improvement in stride length and gait velocity was found when instruction was given to participants to pay equal attention to gait and subtractions (p=0.001, p=0.05) compared to baseline. Short-term improvement in the gait variables was also found after training when compared to the controls (p=0.001, p=0.001). Nevertheless, there was no significant difference in the accurate enumeration rate. Based on the findings, we conclude that divided attention can be used as a strategy to improve slow and short-stepped gait under dual-task conditions. Divided attention can also be used in gait training for short term stride length and gait velocity improvement.

  13. 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…

  14. 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).…

  15. The effects of intermittent illumination on a visual inspection task.

    PubMed

    Kennedy, A; Brysbaert, M; Murray, W S

    1998-02-01

    Two experiments are described in which eye movements were monitored as subjects performed a simple target-spotting task under conditions of intermittent illumination produced by varying the display-screen frame rate on a computer VDU. In Experiment 1, subjects executed a saccade from a fixation point to a target which appeared randomly at a fixed eccentricity of 14 character positions to the left or right. Saccade latency did not differ reliably as a function of screen refresh rate, but average saccade extent at 70 Hz and 110 Hz was reliably shorter than at 90 Hz and 100 Hz. Experiment 2 examined the same task using a range of target eccentricities (7, 14, and 28 character positions to the left and right) and across a wider range of screen refresh rates. The results confirmed the curvilinear relationship obtained in Experiment 1, with average saccade extent reliably shorter at refresh rates of 50 Hz and 125 Hz than at 75 Hz and 100 Hz. While the effect was greater for remote targets, analyses of the proportional target error failed to show a reliable interaction between target eccentricity and display refresh rate. In contrast to Experiment 1, there was a pronounced effect of refresh rate on saccade latency (corrected for time to write the screen frame), with shorter latencies at higher refresh rates. It may be concluded that pulsation at frequencies above fusion disrupts saccade control. However, the curvilinear functional relationship between screen refresh rate and saccade extent obtained in these studies differs from previously reported effects of intermittent illumination on the average size of "entry saccades" (the first saccade to enter a given word) in a task involving word identification (Kennedy & Murray, 1993a, 1996). This conflict of data may arise in part because within-word adjustments in viewing position, which are typical of normal reading, influence measures of average saccade extent.

  16. Task demands moderate stereotype threat effects on memory performance.

    PubMed

    Hess, Thomas M; Emery, Lisa; Queen, Tara L

    2009-06-01

    Previous research has demonstrated that older adults' memory performance is adversely affected by the explicit activation of negative stereotypes about aging. In this study, we examined the impact of stereotype threat on recognition memory, with specific interest in (a) the generalizability of previously observed effects, (b) the subjective experience of memory, and (c) the moderating effects of task demands. Older participants subjected to threat performed worse than did those in a nonthreat condition but only when performance constraints were high (i.e., memory decisions had to be made within a limited time frame). This effect was reflected in the subjective experience of memory, with participants in this condition having a lower ratio of "remember" to "know" responses. The absence of threat effects when constraints were minimal provides important boundary information regarding stereotype influences on memory performance.

  17. Ambiguity and Communication Effects on Small Group Decision-Making Performance.

    ERIC Educational Resources Information Center

    Salazar, Abran J.

    1996-01-01

    Notes that the literature of group studies is controversial and confusing on the effect of communicative variables on small-group decision making. Postulates that two classes of variables (homogeneity and task) moderate the relationship between group communication and group performance. Advances the ambiguity model to reconcile the contradictory…

  18. Questionnaire assessment of estimated radiation effects upon military task performance

    SciTech Connect

    Glickman, A.S.; Winne, P.S.; Morgan, B.B. Jr.; Moe, R.B.

    1984-04-01

    One hundred twenty-five supervisors in four types of U.S. Army combat systems estimated the degree of degradation of military tasks for 30 descriptive symptom complexes associated with various radiation exposures. Results indicated that (a) the relative order of symptom effects were highly consistent across positions and the types of systems, (b) performances were expected to be deleteriously affected under most illness conditions, even mild ones, but incapacitation was not anticipated until illness conditions became quite severe, and (c) the most important factors in estimating performances were fluid loss and fatigability/weakness.

  19. 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

  20. 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

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

    PubMed Central

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

    2015-01-01

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

  2. 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…

  3. Collaborative and Individual Output Tasks and Their Effects on Learning English Phrasal Verbs

    ERIC Educational Resources Information Center

    Nassaji, Hossein; Tian, Jun

    2010-01-01

    Current second language (L2) instruction research has encouraged the use of collaborative output tasks in L2 classrooms. This study examined and compared the effectiveness of two types of output tasks (reconstruction cloze tasks and reconstruction editing tasks) for learning English phrasal verbs. Of interest was whether doing the tasks…

  4. Vocabulary Acquisition through Written Input: Effects of Form-Focused, Message-Oriented, and Comprehension Tasks

    ERIC Educational Resources Information Center

    Tajeddin, Zia; Daraee, Dina

    2013-01-01

    The present study investigated the effect of form-focused and non-form-focused tasks on EFL learners' vocabulary learning through written input. The form-focused task aimed to draw students' attention to the word itself through word recognition activities. Non-form-focused tasks were divided into (a) the comprehension question task, which required…

  5. 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…

  6. 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

  7. Differential Effects of Two T Group Styles

    ERIC Educational Resources Information Center

    Boller, Jon D.

    1974-01-01

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

  8. Dealing with Resistance: Strategies for Effective Group.

    ERIC Educational Resources Information Center

    Higgs, Judith A.

    1992-01-01

    Describes strategies for dealing effectively with resistance in group therapy. Discusses resistant group members; reasons for resistance; group stages; and strategies for dealing with silence, laughter, excessive talking, monopolizing, and intellectualizing and generalizing. Includes discussion of experimental strategies to overcome group…

  9. 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…

  10. 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.

  11. 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…

  12. 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…

  13. 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.

  14. Acute physical exercise affected processing efficiency in an auditory attention task more than processing effectiveness.

    PubMed

    Dutke, Stephan; Jaitner, Thomas; Berse, Timo; Barenberg, Jonathan

    2014-02-01

    Research on effects of acute physical exercise on performance in a concurrent cognitive task has generated equivocal evidence. Processing efficiency theory predicts that concurrent physical exercise can increase resource requirements for sustaining cognitive performance even when the level of performance is unaffected. This hypothesis was tested in a dual-task experiment. Sixty young adults worked on a primary auditory attention task and a secondary interval production task while cycling on a bicycle ergometer. Physical load (cycling) and cognitive load of the primary task were manipulated. Neither physical nor cognitive load affected primary task performance, but both factors interacted on secondary task performance. Sustaining primary task performance under increased physical and/or cognitive load increased resource consumption as indicated by decreased secondary task performance. Results demonstrated that physical exercise effects on cognition might be underestimated when only single task performance is the focus.

  15. Group Size Effects in Employment Testing

    ERIC Educational Resources Information Center

    Hillery, Joseph M.; Fugita, Stephen S.

    1975-01-01

    Effects of the number of individuals coacting while taking two standardized motor performance tests were examined. Increases in aptitude scores corresponding to increases in group size were predicted based upon the summation hypothesis of social facilitation theory. Results indicated a group size effect. (Author/BJG)

  16. The frequency effect for pseudowords in the lexical decision task.

    PubMed

    Perea, Manuel; Rosa, Eva; Gómez, Consolación

    2005-02-01

    Four experiments were designed to investigate whether the frequency of words used to create pseudowords plays an important role in lexical decision. Computational models of the lexical decision task (e.g., the dual route cascaded model and the multiple read-out model) predict that latencies to low-frequency pseudowords should be faster than latencies to high-frequency pseudowords. Consistent with this prediction, results showed that when the pseudowords were created by replacing one internal letter of the base word (Experiments 1 and 3), high-frequency pseudowords yielded slower latencies than low-frequency pseudowords. However, this effect occurred only in the leading edge of the response time (RT) distributions. When the pseudowords were created by transposing two adjacent internal letters (Experiment 2), high-frequency pseudowords produced slower latencies in the leading edge and in the bulk of the RT distributions. These results suggest that transposed-letter pseudowords may be more similar to their base words than replacement-letter pseudowords. Finally, when participants performed a go/no-go lexical decision task with one-letter different pseudowords (Experiment 4), high-frequency pseudowords yielded substantially faster latencies than low-frequency pseudowords, which suggests that the lexical entries of high-frequency words can be verified earlier than the lexical entries of low-frequency words. The implications of these results for models of word recognition and lexical decision are discussed. PMID:15971693

  17. Marijuana effects on visual imagery in a paired-associate task.

    PubMed

    Block, R I; Wittenborn, J R

    1984-06-01

    Marijuana effects on visual imagery, examined using a paired-associate learning task, differed from expectations based on previous subjective reports that marijuana enhances visual imagery. Subjects (48 men, mean age 22.4 yr.) were assigned to four groups (12 subjects per group) differing in (a) whether or not they received specific instructions to use imagery to facilitate learning and (b) whether they received marijuana or placebo. Imagery instructions improved recall, but marijuana did not influence the amount of this improvement. After the memory tests, subjects instructed to use imagery described their images. Marijuana decreased the rated vividness of these imagery descriptions.

  18. 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.

  19. Testing idiom comprehension in aphasic patients: the effects of task and idiom type.

    PubMed

    Papagno, C; Caporali, A

    2007-02-01

    Idiom comprehension in 15 aphasic patients was assessed with three tasks: a sentence-to-picture matching task, a sentence-to-word matching task and an oral definition task. The results of all three tasks showed that the idiom comprehension in aphasic patients was impaired compared to that of the control group, and was significantly affected by the type of task and type of idiom. Whilst performance on the oral definition and sentence-to-picture matching tasks was similarly impaired, the patients performed significantly better on the sentence-to-word matching task. The results confirm the relevance of task and idiom type in drawing conclusions about figurative language interpretation in brain-damaged patients. PMID:16487581

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

    PubMed

    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

  1. 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

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

    ERIC Educational Resources Information Center

    McClelland, Giles Peter

    2012-01-01

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

  3. 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…

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

    PubMed

    Wiseman, Michael C

    2013-10-01

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

  5. Temporal coding in rhythm tasks revealed by modality effects.

    PubMed

    Glenberg, A M; Jona, M

    1991-09-01

    Temporal coding has been studied by examining the perception and reproduction of rhythms and by examining memory for the order of events in a list. We attempt to link these research programs both empirically and theoretically. Glenberg and Swanson (1986) proposed that the superior recall of auditory material, compared with visual material, reflects more accurate temporal coding for the auditory material. In this paper, we demonstrate that a similar modality effect can be produced in a rhythm task. Auditory rhythms composed of stimuli of two durations are reproduced more accurately than are visual rhythms. Furthermore, it appears that the auditory superiority reflects enhanced chunking of the auditory material rather than better identification of durations. PMID:1956312

  6. 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

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

    PubMed Central

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

    2015-01-01

    Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30–77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3’s (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30–40; 41–50; 51–60; 61–77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging. PMID:26305896

  8. 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…

  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. 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.

  11. Visual Cueing Effects Investigation for a Hovering Task

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  12. Trial-type probability and task-switching effects on behavioral response characteristics in a mixed saccade task.

    PubMed

    Pierce, Jordan E; McCardel, J Brett; McDowell, Jennifer E

    2015-03-01

    Eye movement circuitry involved in saccade production offers a model for studying cognitive control: visually guided prosaccades are stimulus-directed responses, while goal-driven antisaccades rely upon more complex control processes to inhibit the prepotent tendency to look toward a cue, transform its spatial location, and generate a volitional saccade in the opposite direction. By manipulating the relative probability of these saccade types, we measured participants' behavioral responses to different levels of implicit trial-type probability and task-switching demands in conditions with relatively long inter-trial fixation and trial-type cue lengths. Results indicated that when prosaccades were less probable in a run, more prosaccade errors were generated; however, for antisaccades, trial-type probability had no effect on the percent of correct responses. For reaction times, specifically in runs with a larger probability of antisaccade trials, latencies increased for both anti- and pro-saccades. Furthermore, task switching resulted in a lower percentage of correct responses on switched trials, but a prior antisaccade trial led to slower reaction times for both trial types (i.e., a task switch cost for prosaccades and switch benefit for antisaccades). These findings indicate that cognitive control demands and residual inhibition from antisaccades alter performance relative to trial-type probability and task switching within a run, with the prosaccade task showing greater susceptibility to the influence of a large probability of cognitively complex antisaccades.

  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. Wiki Work: Can Using Wikis Enhance Student Collaboration for Group Assignment Tasks?

    ERIC Educational Resources Information Center

    Witney, Debbie; Smallbone, Teresa

    2011-01-01

    Dissatisfaction with the quality of student group work, in terms of content and process, from both academics and students, is a constant challenge to the development of appropriate teaching, learning and assessment strategies. Developments in Web 2.0 technology could potentially offer a solution. This paper explores the experience of full-time…

  15. 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.

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

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  17. 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…

  18. 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…

  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. 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.

  1. 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…

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

    ERIC Educational Resources Information Center

    Bockler, Anne; Knoblich, Gunther; Sebanz, Natalie

    2012-01-01

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

  3. 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

  4. 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

  5. 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.

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

    PubMed

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

    2011-02-01

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

  7. 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

  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. 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

  10. Effect of a dual task on postural control in dyslexic children.

    PubMed

    Legrand, Agathe; Bui-Quoc, Emmanuel; Doré-Mazars, Karine; Lemoine, Christelle; Gérard, Christophe-Loïc; Bucci, Maria Pia

    2012-01-01

    Several studies have examined postural control in dyslexic children; however, their results were inconclusive. This study investigated the effect of a dual task on postural stability in dyslexic children. Eighteen dyslexic children (mean age 10.3±1.2 years) were compared with eighteen non-dyslexic children of similar age. Postural stability was recorded with a platform (TechnoConcept®) while the child, in separate sessions, made reflex horizontal and vertical saccades of 10° of amplitude, and read a text silently. We measured the surface and the mean speed of the center of pressure (CoP). Reading performance was assessed by counting the number of words read during postural measures. Both groups of children were more stable while performing saccades than while reading a text. Furthermore, dyslexic children were significantly more unstable than non-dyslexic children, especially during the reading task. Finally, the number of words read by dyslexic children was significantly lower than that of non-dyslexic children and, in contrast to the non-dyslexic children. In line with the U-shaped non-linear interaction model, we suggest that the attention consumed by the reading task could be responsible for the loss of postural control in both groups of children. The postural instability observed in dyslexic children supports the hypothesis that such children have a lack of integration of multiple sensorimotor inputs.

  11. Prediction and control as determinants of behavioural uncertainty: effects on task performance and heart rate reactivity.

    PubMed

    Baker, S R; Stephenson, D

    2000-01-01

    Control or control-belief is often viewed as being directly instrumental in facilitating coping mechanisms in aversive situations, and yet the empirical evidence for the beneficial effects of control is inconclusive. In this study we investigated the role of predictability in determining the effects of perceived control during an aversive reaction time task. Fifty-six subjects were allocated to one of four groups; predictable-control, predictable-no control, unpredictable-control, unpredictable-no control. In the predictable conditions, subjects could temporally predict the occurrence of an aversive noise. In the perceived control conditions, duration of the aversive tone was contingent on subject's performance. All subjects were matched in terms of the nature of the task and in the number and time of receipt of both the warning signal and noise. Heart rate reactivity and two performance parameters were measured, reaction time and performance increase. Both predictability and control-belief led to a reduction in heart rate reactivity, although they appeared to function independently and at different points in the sequence of events. That is, predictability or perceived control was sufficient to mitigate the effects of an aversive situation. Neither perception of control or predictability led to better task performance. These results are discussed in terms of behavioural uncertainty explanations.

  12. Task-Specific and General Cognitive Effects in Chiari Malformation Type I

    PubMed Central

    Allen, Philip A.; Houston, James R.; Pollock, Joshua W.; Buzzelli, Christopher; Li, Xuan; Harrington, A. Katherine; Martin, Bryn A.; Loth, Francis; Lien, Mei-Ching; Maleki, Jahangir; Luciano, Mark G.

    2014-01-01

    Objective Our objective was to use episodic memory and executive function tests to determine whether or not Chiari Malformation Type I (CM) patients experience cognitive dysfunction. Background CM is a neurological syndrome in which the cerebellum descends into the cervical spine causing neural compression, severe headaches, neck pain, and number of other physical symptoms. While primarily a disorder of the cervico-medullary junction, both clinicians and researchers have suspected deficits in higher-level cognitive function. Design and Methods We tested 24 CM patients who had undergone decompression neurosurgery and 24 age- and education-matched controls on measures of immediate and delayed episodic memory, as well as three measures of executive function. Results The CM group showed performance decrements relative to the controls in response inhibition (Stroop interference), working memory computational speed (Ospan), and processing speed (automated digit symbol substitution task), but group differences in recall did not reach statistical significance. After statistical control for depression and anxiety scores, the group effects for working memory and processing speed were eliminated, but not for response inhibition. This response inhibition difference was not due to overall general slowing for the CM group, either, because when controls' data were transformed using the linear function fit to all of the reaction time tasks, the interaction with group remained statistically significant. Furthermore, there was a multivariate group effect for all of the response time measures and immediate and delayed recall after statistical control of depression and anxiety scores. Conclusion These results suggest that CM patients with decompression surgery exhibit cognitive dysfunction compared to age- and education-matched controls. While some of these results may be related to anxiety and depression (likely proxies for chronic pain), response inhibition effects, in particular

  13. 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…

  14. The Effects of Interspersed Maintenance Tasks on Academic Performance in a Severe Childhood Stroke Victim.

    ERIC Educational Resources Information Center

    Koegel, Lynn Kern; Koegel, Robert L.

    1986-01-01

    The study examined effects of task-sequencing variables on the academic performance of an 8-year-old severe stroke victim. Previously acquired (maintenance) task trials were systematically interspersed among new (acquisition) task trials. Results showed improvements in both academic responding and subjective ratings of motivation in spelling,…

  15. 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…

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

    ERIC Educational Resources Information Center

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

    2001-01-01

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

  17. The Effects of Verbal Reinforcement, Interest, and "Usable Performance Feedback" upon Task Performance.

    ERIC Educational Resources Information Center

    Fish, Marian C.; White, Mary Alice

    1978-01-01

    The influence of student task interest and of usable performance feedback on the effectiveness of verbal reinforcement was investigated in fifth graders who received approval, disapproval, or neutral reinforcement. Neither reinforcement nor reinforcement-task variable interaction provided enough motivation to improve accuracy of task performance.…

  18. Generalizability of carry-over effects in the emotional Stroop task.

    PubMed

    Waters, Andrew J; Sayette, Michael A; Franken, Ingmar H A; Schwartz, Joseph E

    2005-06-01

    The emotional Stroop task has been the most widely used task to examine attentional bias to emotionally salient stimuli. In one format of this task, words are presented to participants in a mixed randomized or quasi-randomized sequence. Using a mixed smoking Stroop task, we have previously demonstrated that smokers are slower to respond to words which follow smoking-related words than words which follow neutral words. Here we show that this carry-over effect is present in heroin addicts-but not control subjects-in a heroin Stroop task, and in normal subjects in a stress Stroop task. Thus, the effect generalizes to other populations. In addition, an examination of the studies that have collected data from both mixed and blocked formats provides converging evidence for the presence of carry-over effects. We discuss the implications of the carry-over effect for research using the emotional Stroop task.

  19. 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

  20. Effects of working memory load on uncertain decision-making: evidence from the Iowa Gambling Task

    PubMed Central

    Cui, Ji-Fang; Wang, Ya; Shi, Hai-Song; Liu, Lu-Lu; Chen, Xing-Jie; Chen, Ying-He

    2015-01-01

    The Iowa Gambling Task (IGT) simulates uncertain gains and losses in real life situations and thus is a good measure of uncertain decision-making. The role of working memory (WM) in IGT performance still remains unclear. The present study aimed to examine the effect of WM on IGT performance. Three groups of participants matched on gender ratio were randomly assigned to no WM load, low WM load, and high WM load conditions. Initially the three groups did not show significant difference in WM capacity. They finished a modified version of IGT and then their implicit learning effect and explicit cognition on IGT were assessed. Results indicated a linear increasing trend of IGT performance among high WM load, low WM load and no WM load groups; participants in the no WM load and low WM load groups revealed implicit learning effect, while participants in the high WM load group did not; all participants showed explicit cognition on IGT to the same level. These results suggested that participants in the high WM load group showed good explicit cognition to IGT but showed poor performance. This pattern is similar to frontal patients. Further studies should be conducted to explore this issue. PMID:25745409

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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…

  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 Task Instruction Sheets on the Performance of Vocational Horticulture Students. Summary of Research, 29.

    ERIC Educational Resources Information Center

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

    A study investigated the effect that task instruction sheets had on the performance of vocational horticulture students when being taught a unit on poinsettia production. Using a post-test only control group design, researchers administered a 35-item multiple choice test on poinsettia production to 207 students in 12 randomly selected eleventh…

  10. 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…

  11. 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…

  12. 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…

  13. Human performance in a multiple-task environment: effects of automation reliability on visual attention allocation.

    PubMed

    Cullen, Ralph H; Rogers, Wendy A; Fisk, Arthur D

    2013-11-01

    Diagnostic automation has been posited to alleviate the high demands of multiple-task environments; however, mixed effects have been found pertaining to performance aid success. To better understand these effects, attention allocation must be studied directly. We developed a multiple-task environment to study the effects of automation on visual attention. Participants interacted with a system providing varying levels of automation and automation reliability and then were transferred to a system with no support. Attention allocation was measured by tracking the number of times each task was viewed. We found that participants receiving automation allocated their time according to the task frequency and that tasks that benefited most from automation were most harmed when it was removed. The results suggest that the degree to which automation affects multiple-task performance is dependent on the relative attributes of the tasks involved. Moreover, there is an inverse relationship between support and cost when automation fails.

  14. 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.

  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. 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.

  17. 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.

  18. 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…

  19. 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…

  20. 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.

  1. 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

  2. EEG oscillations reflect task effects for the change detection in vocal emotion.

    PubMed

    Chen, Xuhai; Pan, Zhihui; Wang, Ping; Zhang, Lijie; Yuan, Jiajin

    2015-06-01

    How task focus affects recognition of change in vocal emotion remains in debate. In this study, we investigated the role of task focus for change detection in emotional prosody by measuring changes in event-related electroencephalogram (EEG) power. EEG was recorded for prosodies with and without emotion change while subjects performed emotion change detection task (explicit) and visual probe detection task (implicit). We found that vocal emotion change induced theta event-related synchronization during 100-600 ms regardless of task focus. More importantly, vocal emotion change induced significant beta event-related desynchronization during 400-750 ms under explicit instead of implicit task condition. These findings suggest that the detection of emotional changes is independent of task focus, while the task focus effect in neural processing of vocal emotion change is specific to the integration of emotional deviations.

  3. 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

  4. 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

  5. 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

  6. When co-action eliminates the Simon effect: disentangling the impact of co-actor's presence and task sharing on joint-task performance.

    PubMed

    Sellaro, Roberta; Treccani, Barbara; Rubichi, Sandro; Cubelli, Roberto

    2013-01-01

    This study aimed at assessing whether the mere belief of performing a task with another person, who is in charge of the complementary part of the task, is sufficient for the so-called joint Simon effect to occur. In all three experiments of the study, participants sat alone in a room and underwent two consecutive Go/NoGo tasks that were identical except for the instructions. In Experiment 1, participants performed the task first individually (baseline task), and then either co-acting with another person who responded from an unknown location to the NoGo stimuli (joint task) or imaging themselves responding to the NoGo stimuli (imaginative task). Relative to the baseline, the instructions of the imaginative task made the Simon effect occur, while those of the joint task were ineffective in eliciting the effect. This result suggests that sharing a task with a person who is known to be in charge of the complementary task, but is not physically present, is not sufficient to induce the representation of an alternative response able to produce interference, which happens instead when the instructions explicitly require to imagine such a response. Interestingly, we observed that when the Simon effect was already present in the baseline task (i.e., when the response alternative to the Go response was represented in the individual task due to non-social factors), it disappeared in the joint task. We propose that, when no information about the co-actor's position is available, the division of labor between the participant and co-actor allows participants to filter out the possible (incidental) representation of the alternative response from their task representation, thus eliminating potential sources of interference. This account is supported by the results of Experiments 2 and 3 and suggests that under certain circumstances task-sharing may reduce the interference produced by the irrelevant information, rather than increase it.

  7. When co-action eliminates the Simon effect: disentangling the impact of co-actor's presence and task sharing on joint-task performance

    PubMed Central

    Sellaro, Roberta; Treccani, Barbara; Rubichi, Sandro; Cubelli, Roberto

    2013-01-01

    This study aimed at assessing whether the mere belief of performing a task with another person, who is in charge of the complementary part of the task, is sufficient for the so-called joint Simon effect to occur. In all three experiments of the study, participants sat alone in a room and underwent two consecutive Go/NoGo tasks that were identical except for the instructions. In Experiment 1, participants performed the task first individually (baseline task), and then either co-acting with another person who responded from an unknown location to the NoGo stimuli (joint task) or imaging themselves responding to the NoGo stimuli (imaginative task). Relative to the baseline, the instructions of the imaginative task made the Simon effect occur, while those of the joint task were ineffective in eliciting the effect. This result suggests that sharing a task with a person who is known to be in charge of the complementary task, but is not physically present, is not sufficient to induce the representation of an alternative response able to produce interference, which happens instead when the instructions explicitly require to imagine such a response. Interestingly, we observed that when the Simon effect was already present in the baseline task (i.e., when the response alternative to the Go response was represented in the individual task due to non-social factors), it disappeared in the joint task. We propose that, when no information about the co-actor's position is available, the division of labor between the participant and co-actor allows participants to filter out the possible (incidental) representation of the alternative response from their task representation, thus eliminating potential sources of interference. This account is supported by the results of Experiments 2 and 3 and suggests that under certain circumstances task-sharing may reduce the interference produced by the irrelevant information, rather than increase it. PMID:24312066

  8. Effects of a Task-specific Exercise Program on Balance, Mobility, and Muscle Strength in the Elderly

    PubMed Central

    Seo, Hyung-Seok; Lee, Jung-Ho; Park, Young-Han

    2014-01-01

    [Purpose] The aim of this study was to investigate the effects of a task-specific exercise program based on motor learning on balance ability and strength of the lower extremity in the elderly with/without falling experiences. [Subjects and Methods] Individuals who had experiences of falling over 2 times within the past 6 months were included in the falling group. The task-specific exercise program consisted of 3 stages (weeks 1–2, 3–4, and 5–6) and was conducted according to the level of difficulty in this study. [Results] The scores of the Korean version of the Activities-Specific Balance Confidence Scale and Performance-Oriented Mobility Assessment were significantly changed in both the falling group and non-falling group after the task-specific exercise program. In comparisons between the falling group and non-falling group, there were also significant differences in the Korean version of the Activities-Specific Balance Confidence Scale and muscle strength of the semitendinosus and gastrocnemius. [Conclusion] The task-specific exercise program has a positive effect on balance ability and muscle strength related to falls in the elderly. PMID:25435679

  9. Effect of short and long exposure duration and dual-tasking on a global-local task.

    PubMed

    Andres, Allison J D; Fernandes, Myra A

    2006-07-01

    Past research has demonstrated a global advantage in responses to visually presented hierarchical stimuli such that, on incongruent trials, the global form interferes with responses to the local level [Kimchi, R. (1992). Primacy of wholistic processing and global/local paradigm: A critical review. Psychological Bulletin, 112, 24-38]. In Experiment 1, 32 adults performed alternating blocks of global or local identification of hierarchical letter stimuli in which the global and local letters were congruent, incongruent, or neutral, and were presented at either a short (17 ms) or long (100 ms) exposure duration. A global advantage was demonstrated at both durations. In the local-directed task, interference on incongruent, relative to neutral, trials was observed at both exposure durations, but facilitation on congruent trials, relative to neutral trials, was present only when stimuli were presented at the long exposure duration. In Experiment 2, global or local identification was performed by another group of 24 adults at either a long or short exposure duration, and also under conditions of full attention (FA) or dual-task (DT) conditions with a digit-monitoring task. Under FA, we again found significant interference at both exposure durations, but facilitation only at the long exposure duration. Under DT conditions, the pattern of facilitation and interference at the short duration remained unchanged. At the long duration, however, dual-tasking eliminated interference in the RT but not error data, while facilitation was present in both sets of data. Results are in line with a perceptual account of the global advantage, and suggest that facilitation requires consciously-mediated processes, whereas interference does not.

  10. Effects of Ability Grouping on Student Achievement.

    ERIC Educational Resources Information Center

    Kulik, James A.; Kulik, Chen-Lin C.

    1987-01-01

    Examines the effect of within-class and between-class ability groupings on the academic achievement of gifted elementary and secondary level students. Results showed that gifted students gained more academically than they would have if they had been taught in heterogeneous classes. (PS)

  11. 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…

  12. 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

  13. The effect of hypothermia on the rat's spatial memory in the water tank task.

    PubMed

    Panakhova, E; Buresová, O; Bures, J

    1984-11-01

    The effect of hypothermia on the retention of the water tank navigation task has been examined in 21 male hooded rats. After a 3-min swimming test on Day 1 the animals were trained on Days 2 and 3 (2 X 12 trials) to find a small submerged platform 1 cm below the surface of a large pool (120 cm in diameter) of opaque water. On Day 4, the rats were divided into three groups (n = 7) which were cooled to colonic temperatures of 22-24 degrees C (H1), 25-27 degrees C (H2), and 28-31 degrees C (H3), respectively, and given 12 retrieval trials in the water tank. Average escape latencies increased from 6 s in normothermic rats on Day 3 to 33, 19, and 12 s on Day 4 in the H1, H2, and H3 groups, respectively. Under the same testing conditions the performance of groups H1, H2, and H3 improved on Day 5 to 20, 8 and 6 s, respectively. It is concluded that spatial memory retrieval is resistant to mild hypothermia (30 degrees C), but that it is severely impaired at body temperatures below 25 degrees C. Reacquisition of the task is slowed down but not fully prevented in deep hypothermia.

  14. 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…

  15. 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.

  16. Memory consolidation and reconsolidation of an inhibitory avoidance task in mice: effects of a new different learning task.

    PubMed

    Boccia, M M; Blake, M G; Acosta, G B; Baratti, C M

    2005-01-01

    CF-1 male mice were trained in an inhibitory avoidance task using a high footshock (1.2mA, 50Hz, 1 s) in order to reduce the influence of extinction on retention performance. A single session of 5 min exposure to a hole-board (nose-poke behavior), either immediately after training or the first retention test (memory reactivation) impaired retention performance over two consecutive days. The effects were time-dependent since they were not observed when the exposure to the hole-board was delayed 3 h. When mice were habituated to the hole-board (5 min/day, 5 days), and then trained in an inhibitory avoidance task, the immediately post-training or memory reactivation exposure to the hole-board did not modify retention performance over two consecutive days. The effects of the post-reactivation acute exposure to the hole-board were long-lasting (21 days). Reinstatement was not observed in our experimental conditions. The non-spontaneous recovery of retention performance over 21-days and the lack of reinstatement, suggest that the impairment of retention performance observed was not probably due to a deficit in memory retrieval. These findings suggest that the exposure to a potential new learning situation impairs not only memory consolidation but also memory reconsolidation of the original learning task. PMID:16084650

  17. Memory consolidation and reconsolidation of an inhibitory avoidance task in mice: effects of a new different learning task.

    PubMed

    Boccia, M M; Blake, M G; Acosta, G B; Baratti, C M

    2005-01-01

    CF-1 male mice were trained in an inhibitory avoidance task using a high footshock (1.2mA, 50Hz, 1 s) in order to reduce the influence of extinction on retention performance. A single session of 5 min exposure to a hole-board (nose-poke behavior), either immediately after training or the first retention test (memory reactivation) impaired retention performance over two consecutive days. The effects were time-dependent since they were not observed when the exposure to the hole-board was delayed 3 h. When mice were habituated to the hole-board (5 min/day, 5 days), and then trained in an inhibitory avoidance task, the immediately post-training or memory reactivation exposure to the hole-board did not modify retention performance over two consecutive days. The effects of the post-reactivation acute exposure to the hole-board were long-lasting (21 days). Reinstatement was not observed in our experimental conditions. The non-spontaneous recovery of retention performance over 21-days and the lack of reinstatement, suggest that the impairment of retention performance observed was not probably due to a deficit in memory retrieval. These findings suggest that the exposure to a potential new learning situation impairs not only memory consolidation but also memory reconsolidation of the original learning task.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Graphophonological processes in dyslexic readers of French: a longitudinal study of the explicitness effect of tasks.

    PubMed

    Daigle, Daniel; Berthiaume, Rachel; Plisson, Anne; Demont, Elisabeth

    2012-07-01

    Given the well-acknowledged phonological deficit found in dyslexic children, this study was aimed at investigating graphophonological processes in dyslexic readers of French over a 1-year period. Among the different types of phonological processing can be distinguished those related to phonological awareness based on knowledge of the oral language and graphophonological processes based on correspondences between the oral and the written language. In this study, we evaluated graphophonemic and graphosyllabic processes using, in each case, two different tasks varying in the degree of cognitive constraint associated with the task (CC- vs CC+). Twenty 11 year-old dyslexic students were compared with younger normal-readers of the same reading level (RA, n=26) and to normal-readers of the same age (CA, n=24). Two variables were considered in the analyses: accuracy and response latency. Results show that dyslexic readers do process written items at the graphophonological level. Also, results indicate main effects of task (CC- vs CC+), time (T1 vs T2), and group (DYS vs RA vs CA). In general, dyslexic participants' performances are comparable to those of RA and differ from those of CA. PMID:22441904

  4. 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

  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. 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…

  7. 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…

  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. The Effect of Occupational Growth on Labor Force Task Characteristics.

    ERIC Educational Resources Information Center

    Szafran, Robert F.

    1996-01-01

    Examination of changes in 495 occupations from 1950-1990 shows an increased likelihood of tasks with high levels of complexity and social interaction, decreased likelihood of fine or gross motor skills or harsh climatic conditions. There is evidence that jobs have become polarized on the need for fine motor skills and level of social interaction.…

  10. 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

  11. 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…

  12. Effects of Payoff and Task Context on Academic Risk Taking.

    ERIC Educational Resources Information Center

    Clifford, Margaret M.; Chou, Fen-Chang

    1991-01-01

    Fourth grade Taiwan students (94 males and 97 females) completed 2 cognitive risk-taking tasks with variable payoff or fixed payoff in a game or test context. Both variable payoff and game context increased the level of academic risk taking. Results are discussed concerning interactions between ability and risk taking. (SLD)

  13. Sequential effects after practice with the dominant and non-dominant hand on the acquisition of a sliding task in schoolchildren.

    PubMed

    Senff, Oliver; Weigelt, Matthias

    2011-03-01

    This study was designed to investigate sequential effects after practice with the dominant and non-dominant hand on the acquisition of a new motor task. A total of 64 middle school children were asked to practise a cent-slide task, which required them to slide coins from one side of a cardboard into a circular target on the opposite side. Four groups practised this task within different practice schedules: (1) participants practised only with their dominant hand (right-only group); (2) participants used only their non-dominant hand (left-only group); (3) participants started to practise the skill with their dominant hand and then switched to their non-dominant hand (right-to-left group); or (4) participants started to practise the skill with their non-dominant hand and then switched to their dominant hand (left-to-right group). The acquisition of the task was facilitated after initial practice with the non-dominant hand. This was reflected in a better retention of the task and a stronger performance under a modified testing situation of the left-to-right group when compared to all other groups. Also, the left-only group showed larger interlimb transfer effects to the untrained hand than the right-only group. It is concluded that the sequence in which the dominant and non-dominant hands are used to practise influences the acquisition of new motor tasks.

  14. 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

  15. 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

  16. 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.

  17. Short-term visual deprivation reduces interference effects of task-irrelevant facial expressions on affective prosody judgments.

    PubMed

    Fengler, Ineke; Nava, Elena; Röder, Brigitte

    2015-01-01

    Several studies have suggested that neuroplasticity can be triggered by short-term visual deprivation in healthy adults. Specifically, these studies have provided evidence that visual deprivation reversibly affects basic perceptual abilities. The present study investigated the long-lasting effects of short-term visual deprivation on emotion perception. To this aim, we visually deprived a group of young healthy adults, age-matched with a group of non-deprived controls, for 3 h and tested them before and after visual deprivation (i.e., after 8 h on average and at 4 week follow-up) on an audio-visual (i.e., faces and voices) emotion discrimination task. To observe changes at the level of basic perceptual skills, we additionally employed a simple audio-visual (i.e., tone bursts and light flashes) discrimination task and two unimodal (one auditory and one visual) perceptual threshold measures. During the 3 h period, both groups performed a series of auditory tasks. To exclude the possibility that changes in emotion discrimination may emerge as a consequence of the exposure to auditory stimulation during the 3 h stay in the dark, we visually deprived an additional group of age-matched participants who concurrently performed unrelated (i.e., tactile) tasks to the later tested abilities. The two visually deprived groups showed enhanced affective prosodic discrimination abilities in the context of incongruent facial expressions following the period of visual deprivation; this effect was partially maintained until follow-up. By contrast, no changes were observed in affective facial expression discrimination and in the basic perception tasks in any group. These findings suggest that short-term visual deprivation per se triggers a reweighting of visual and auditory emotional cues, which seems to possibly prevail for longer durations.

  18. 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

  19. 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…

  20. Isolating a Mediated Route for Response Congruency Effects in Task Switching

    ERIC Educational Resources Information Center

    Schneider, Darryl W.

    2015-01-01

    Response congruency effects in task switching reflect worse performance for incongruent targets associated with different responses across tasks than for congruent targets associated with the same response. In the present study, the author investigated whether the effects can be produced solely by a mediated route for response selection, whereby…

  1. 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…

  2. 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.…

  3. The effect of cognitive aging on implicit sequence learning and dual tasking.

    PubMed

    Vandenbossche, Jochen; Coomans, Daphné; Homblé, Koen; Deroost, Natacha

    2014-01-01

    We investigated the influence of attentional demands on sequence-specific learning by means of the serial reaction time task (Nissen and Bullemer, 1987) in young (age 18-25) and aged (age 55-75) adults. Participants had to respond as fast as possible to a stimulus presented in one of four horizontal locations by pressing a key corresponding to the spatial position of the stimulus. During the training phase sequential blocks were accompanied by (1) no secondary task (single), (2) a secondary tone counting task (dual tone), or (3) a secondary shape counting task (dual shape). Both secondary tasks were administered to investigate whether low and high interference tasks interact with implicit learning and age. The testing phase, under baseline single condition, was implemented to assess differences in sequence-specific learning between young and aged adults. Results indicate that (1) aged subjects show less sequence learning compared to young adults, (2) young participants show similar implicit learning effects under both single and dual task conditions when we account for explicit awareness, and (3) aged adults demonstrate reduced learning when the primary task is accompanied with a secondary task, even when explicit awareness is included as a covariate in the analysis. These findings point to implicit learning deficits under dual task conditions that can be related to cognitive aging, demonstrating the need for sufficient cognitive resources while performing a sequence learning task.

  4. 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

  5. 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

  6. The end-state comfort effect in 3- to 8-year-old children in two object manipulation tasks.

    PubMed

    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.

  7. The Effects of Time on Task in Response Selection--An ERP Study of Mental Fatigue.

    PubMed

    Möckel, Tina; Beste, Christian; Wascher, Edmund

    2015-01-01

    Long lasting involvement in a cognitive task leads to mental fatigue. Substantial efforts have been undertaken to understand this phenomenon. However, it has been demonstrated that some changes with time on task are not only related to mental fatigue. The present study intends to clarify these effects of time on task unrelated to mental fatigue on response selection processes at the behavioural and electrophysiological level (using event-related potentials, ERPs). Participants had to perform a Simon task for more than 3 hours and rated their experienced mental fatigue and motivation to continue with the task at several time points during the experiment. The results show that at the beginning of the experiment some unspecific modulations of training and adaptation are evident. With time on task participants' ability to resolve response conflict appears to become impaired. The results reveal that time on task effects cannot be completely explained by mental fatigue. Instead, it seems that an interplay of adaptation at the beginning and motivational effects in the course of a task modulate performance and neurophysiological parameters. In future studies it will be important to account for the relative contribution of adaptation and motivation parameters when time on task effects are investigated.

  8. The Effects of Time on Task in Response Selection - An ERP Study of Mental Fatigue

    PubMed Central

    Möckel, Tina; Beste, Christian; Wascher, Edmund

    2015-01-01

    Long lasting involvement in a cognitive task leads to mental fatigue. Substantial efforts have been undertaken to understand this phenomenon. However, it has been demonstrated that some changes with time on task are not only related to mental fatigue. The present study intends to clarify these effects of time on task unrelated to mental fatigue on response selection processes at the behavioural and electrophysiological level (using event-related potentials, ERPs). Participants had to perform a Simon task for more than 3 hours and rated their experienced mental fatigue and motivation to continue with the task at several time points during the experiment. The results show that at the beginning of the experiment some unspecific modulations of training and adaptation are evident. With time on task participants’ ability to resolve response conflict appears to become impaired. The results reveal that time on task effects cannot be completely explained by mental fatigue. Instead, it seems that an interplay of adaptation at the beginning and motivational effects in the course of a task modulate performance and neurophysiological parameters. In future studies it will be important to account for the relative contribution of adaptation and motivation parameters when time on task effects are investigated. PMID:26054837

  9. Age, task complexity, and sex as potential moderators of attentional focus effects.

    PubMed

    Becker, Kevin; Smith, Peter J K

    2013-08-01

    The study tested whether age, sex, or task complexity moderate the effect of attentional focus on motor learning. Children (24 boys, 24 girls) and adults (24 men, 24 women) were assigned to an internal or external attentional focus, and were timed while riding either a Double Pedalo with handles (simple task) or without handles (complex task) over a distance of 7 meters. A Double Pedalo is a four-wheeled device that involves standing on two connected platforms, and alternately pushing them forward to make it move. Participants completed 20 acquisition trials, followed by a 24-hour retention test. For the simpler task, no time differences due to attentional focus emerged. With the complex task, an external focus resulted in faster times in retention than an internal focus, but only for males. These findings suggest that attentional focus affects children and adults similarly, but task complexity and sex moderate these effects.

  10. 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

  11. 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

  12. 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

  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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. Cognitive tasks during expectation affect the congruency ERP effects to facial expressions.

    PubMed

    Lin, Huiyan; Schulz, Claudia; Straube, Thomas

    2015-01-01

    Expectancy congruency has been shown to modulate event-related potentials (ERPs) to emotional stimuli, such as facial expressions. However, it is unknown whether the congruency ERP effects to facial expressions can be modulated by cognitive manipulations during stimulus expectation. To this end, electroencephalography (EEG) was recorded while participants viewed (neutral and fearful) facial expressions. Each trial started with a cue, predicting a facial expression, followed by an expectancy interval without any cues and subsequently the face. In half of the trials, participants had to solve a cognitive task in which different letters were presented for target letter detection during the expectancy interval. Furthermore, facial expressions were congruent with the cues in 75% of all trials. ERP results revealed that for fearful faces, the cognitive task during expectation altered the congruency effect in N170 amplitude; congruent compared to incongruent fearful faces evoked larger N170 in the non-task condition but the congruency effect was not evident in the task condition. Regardless of facial expression, the congruency effect was generally altered by the cognitive task during expectation in P3 amplitude; the amplitudes were larger for incongruent compared to congruent faces in the non-task condition but the congruency effect was not shown in the task condition. The findings indicate that cognitive tasks during expectation reduce the processing of expectation and subsequently, alter congruency ERP effects to facial expressions.

  19. 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…

  20. Preempting performance challenges: the effects of inoculation messaging on attacks to task self-efficacy.

    PubMed

    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.

  1. 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

  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. Presentation and task effects on migration errors in attentional dyslexia.

    PubMed

    Mayall, Kate; Humphreys, Glyn W

    2002-01-01

    We report a case study of a patient, FL, who shows symptoms of attentional dyslexia. He performs better at reading aloud single words than pairs of words, where he tends to make letter migration errors. These letter migrations are particularly prevalent from the word presented on the right into FL's response to the word presented on the left. Performance on the word pair reading task is improved if the two words are presented in different cases or the space between them is increased. Further, FL performs better at reading a target word if he is only required to name the initial letter of a distractor word rather than read the whole word. However, single letter distractors then produce more interference than whole words. These findings are consistent with FL having poor letter location coding when attention is diffuse [Cognitive Neuropsychol. 18 (2001) 551; Cognitive Neuropsychol. 13 (1996) 205]. In addition, representations on the left side of his attentional space are particularly weak, and so vulnerable to stimuli on the right when FL adopts a wide spatial window for the task. The data point to a pre-categorical deficit in reading in this case.

  4. The Brain Effective Connectivity of Chinese during Rhyming Task

    PubMed Central

    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

  5. 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

  6. 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

  7. 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

  8. The Effect of Video Game “Warm-up” on Performance of Laparoscopic Surgery Tasks

    PubMed Central

    Gentile, Douglas A.; Hanigan, Kevin; Danner, Omar K.

    2012-01-01

    Background: Performing laparoscopic procedures requires special training and has been documented as a significant source of surgical errors. “Warming up” before performing a task has been shown to enhance performance. This study investigates whether surgeons benefit from “warming up” using select video games immediately before performing laparoscopic partial tasks and clinical tasks. Methods: This study included 303 surgeons (249 men and 54 women). Participants were split into a control (n=180) and an experimental group (n=123). The experimental group played 3 previously validated video games for 6 minutes before task sessions. The Cobra Rope partial task and suturing exercises were performed immediately after the warm-up sessions. Results: Surgeons who played video games prior to the Cobra Rope drill were significantly faster on their first attempt and across all 10 trials. The experimental and control groups were significantly different in their total suturing scores (t=2.28, df=288, P<.05). The overall Top Gun score showed that the experimental group performed marginally better overall. Conclusion: This study demonstrates that subjects completing “warming-up” sessions with select video games prior to performing laparoscopic partial and clinical tasks (intracorporeal suturing) were faster and had fewer errors than participants not engaging in “warm-up.” More study is needed to determine whether this translates into superior procedural execution in the clinical setting. PMID:22906322

  9. 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

  10. 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

  11. Effects of Task Complexity on the Fluency and Lexical Complexity in EFL Students' Argumentative Writing

    ERIC Educational Resources Information Center

    Ong, Justina; Zhang, Lawrence Jun

    2010-01-01

    Based on Robinson's (2001a,b, 2003) Cognition Hypothesis and Skehan's (1998) Limited Attentional Capacity Model, this study explored the effects of task complexity on the fluency and lexical complexity of 108 EFL students' argumentative writing. Task complexity was manipulated using three factors: (1) availability of planning time; (2) provision…

  12. 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…

  13. 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…

  14. Effect of Task-Inherent Production Modes on EFL Learners' Focus on Form

    ERIC Educational Resources Information Center

    Niu, Ruiying

    2009-01-01

    It is now generally agreed that "output" functions to promote language learning through focus on form. Empirical studies reveal that oral communicative tasks can arouse learners' negotiation of meaning, but they are not so effective in bringing about focus on form. Hence, researchers have suggested using collaborative writing tasks to enhance…

  15. 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…

  16. Personalised Adaptive Task Selection in Air Traffic Control: Effects on Training Efficiency and Transfer

    ERIC Educational Resources Information Center

    Salden, Ron J. C. M.; Paas, Fred; van Merrienboer, Jeroen J. G.

    2006-01-01

    The differential effects of four task selection methods on training efficiency and transfer in a computer-based training for Air Traffic Control were investigated. Two personalised conditions were compared with two corresponding yoked control conditions. The hypothesis that personalised adaptive task selection leads to more efficient training than…

  17. 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…

  18. 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…

  19. 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…

  20. 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)

  1. 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.…

  2. 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…

  3. 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…

  4. 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…

  5. Effects of the Protestant Work Ethic and Perceived Challenge on Time Allocated to an Experimental Task.

    ERIC Educational Resources Information Center

    Tang, Thomas Li-Ping

    Goal-setting literature has suggested that specific, difficult goals will produce higher performance levels than easy goals. A difficult task or one with negative performance feedback may increase an individual's perceived challenge of the task which may in turn enhance his motivation. Effects of the Protestant work ethic and perceived challenge…

  6. 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.

  7. 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

  8. 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

  9. 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

  10. Resting-state BOLD networks versus task-associated functional MRI for distinguishing Alzheimer's disease risk groups.

    PubMed

    Fleisher, Adam S; Sherzai, Ayesha; Taylor, Curtis; Langbaum, Jessica B S; Chen, Kewei; Buxton, Richard B

    2009-10-01

    To assess the ability of resting-state functional magnetic resonance imaging to distinguish known risk factors for AD, we evaluated 17 cognitively normal individuals with a family history of AD and at least one copy of the apolipoprotein e4 allele compared to 12 individuals who were not carriers of the APOE4 gene and did not have a family history of AD. Blood oxygen level dependent fMRI was performed evaluating encoding-associated signal and resting-state default mode network signal differences between the two risk groups. Neurocognitive testing revealed that the high risk group performed worse on category fluency testing, but the groups were equivalent on all other cognitive measures. During encoding of novel face-name pairs, there were no regions of encoding-associated BOLD activations that were different in the high risk group. Encoding-associated deactivations were greater in magnitude in the low risk group in the medial and right lateral parietal cortex, similar to findings in AD studies. The resting-state DMN analysis demonstrated nine regions in the prefrontal, orbital frontal, temporal and parietal lobes that distinguished the two risk groups. Resting-state DMN analysis could distinguish risk groups with an effect size of 3.35, compared to an effect size of 1.39 using encoding-associated fMRI techniques. Imaging of the resting state avoids performance related variability seen in activation fMRI, is less complicated to acquire and standardize, does not require radio-isotopes, and may be more effective at identifying functional pathology associated with AD risk compared to non-resting fMRI techniques.

  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. 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.

  14. Report of ICRP Task Group 80: 'radiological protection in geological disposal of long-lived solid radioactive waste'.

    PubMed

    Weiss, W

    2012-01-01

    The report of International Commission on Radiological Protection (ICRP) Task Group 80 entitled 'Radiological protection in geological disposal of long-lived solid radioactive waste' updates and consolidates previous ICRP recommendations related to solid waste disposal (ICRP Publications 46, 77, and 81). The recommendations given in this report apply specifically to geological disposal of long-lived solid radioactive waste. The report explains how the 2007 system of radiological protection, described in ICRP Publication 103, can be applied in the context of the geological disposal of long-lived solid radioactive waste. The report is written as a self-standing document. It describes the different stages in the lifetime of a geological disposal facility, and addresses the application of relevant radiological protection principles for each stage depending on the various exposure situations that can be encountered. In particular, the crucial factor that influences application of the protection system over the different phases in the lifetime of a disposal facility is the level of oversight that is present. The level of oversight affects the capability to reduce or avoid exposures. Three main time frames have to be considered for the purpose of radiological protection: time of direct oversight when the disposal facility is being implemented and active oversight is taking place; time of indirect oversight when the disposal facility is sealed and indirect oversight is being exercised to provide additional assurance on behalf of the population; and time of no oversight when oversight is no longer exercised because memory is lost.

  15. Dual task interference during walking: The effects of texting on situational awareness and gait stability.

    PubMed

    Lim, Jongil; Amado, Avelino; Sheehan, Leo; Van Emmerik, Richard E A

    2015-10-01

    Dual-task interference caused by mobile phone use while walking increases safety risks by increasing attentional and cognitive demands. Situational awareness, important for control of walking and safety, has been examined previously but measured only by the awareness of visually noteworthy objects in the environment or the number of times the person looked up from the phone. This study systematically investigated the effects of texting on situational awareness to different environments and its consequent impact on gait kinematics. Twenty healthy volunteers walked on a treadmill while texting and attending to visual tasks simultaneously. Gait parameters and situational awareness examined under dual-task conditions (walk and text or walk, text, and visual task) were compared with those of single-task conditions (text, walk or visual task only). The size of the visual field, display duration of the visual cue, and visual acuity demand were varied across the visual task conditions. About half of the visual cues provided during walking and texting were not perceived (48.3%) as compared to the visual task only condition. The magnitude of this loss of situational awareness was dependent upon the nature of visual information provided. While gait parameters were not different among visual task conditions, greater total medial-lateral excursion of the pelvis was observed in the walk and text condition compared to the walk only condition, showing the dual-task effects of texting on gait kinematics. The study provides further evidence of dual-task effects of texting on situational awareness as well as gait kinematics.

  16. Inhibitory effect of an intellectual task on breathing after voluntary hyperventilation.

    PubMed

    Chin, K; Ohi, M; Fukui, M; Kita, H; Tsuboi, T; Noguchi, T; Otsuka, N; Hirata, H; Mishima, M; Kuno, K

    1996-09-01

    We investigated the effects of an intellectual task on posthyperventilation (PHV) breathing by using a video game. Eight normal subjects were placed in a supine positions. The game task by itself led to increase ventilation compared with the control tasks via an increase in the average inspiratory flow rate (P < 0.01) and the respiratory frequency (P < 0.001). After hypocapnic voluntary hyperventilation (VHV), the task led to a decrease in the 1-min PHV breathing level compared with the control tasks after VHV [after VHV, first 60 s average minute ventilation while watching television and while playing a video game are 5.54 +/- 2.91 (SD) and 2.05 +/- 1.40 l/min, respectively; P < 0.01]. Only one subject showed PHV apnea for at least 10 s during the control protocol, whereas seven of the same eight subjects showed PHV apnea while performing the task. After isocapnic VHV, the task still led to a decrease in PHV breathing compared with the control tasks. However, this decrease was smaller than in the hypocapnic studies and was only significant during the first 15 s of recovery. These results suggest that increased activity in the higher centers of the central nervous system has an inhibitory effect on PHV breathing at a time when the effects of short-term potentiation after VHV, hypocapnia, and perhaps other mechanisms would be expected to be acting on breathing.

  17. 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

  18. 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

  19. 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

  20. Effect of bandwidth knowledge of results on the learning of a grip force control task.

    PubMed

    Ugrinowitsch, Herbert; Ugrinowitsch, Alessandra Aguilar Coca; Benda, Rodolfo Novellino; Tertuliano, Ivan Wallan

    2010-12-01

    An experiment was conducted to investigate the persistence of the effect of "bandwidth knowledge of results (KR)" manipulated during the learning phase of performing a manual force-control task. The experiment consisted of two phases, an acquisition phase with the goal of maintaining 60% maximum force in 30 trials, and a second phase with the objective of maintaining 40% of maximum force in 20 further trials. There were four bandwidths of KR: when performance error exceeded 5, 10, or 15% of the target, and a control group (0% bandwidth). Analysis showed that 5, 10, and 15% bandwidth led to better performance than 0% bandwidth KR at the beginning of the second phase and persisted during the extended trials.

  1. 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

  2. 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

  3. 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

  4. The effect of task in deaf readers' graphophonological processes: a longitudinal study.

    PubMed

    Daigle, Daniel; Berthiaume, Rachel; Demont, Elisabeth

    2012-01-01

    This article reports on an investigation of graphophonological processes in deaf readers of French over a 1-year period. Deaf readers are known to have a phonological deficit compared to hearing peers, and conclusions from studies on this question are often conflicting. Among the different types of phonological processing, we can identify graphophonological processes based on correspondences between the oral and the written language. In this investigation, we evaluated graphophonemic and graphosyllabic processes using, in each case, two different tasks varying in their degree of cognitive constraints (CC- vs. CC+). Nineteen 11 year-old deaf students were compared to younger normal readers of the same reading level (RA, n = 17) and to normal readers of the same age (CA, n = 20). Two variables were considered in the analyses: accuracy and response latency. Results show that deaf readers do process written items at the graphophonological level and that graphophonological processes are related to reading ability. Also, results indicate main effects of task (CC- vs. CC+), time (T1 vs. T2), and group. In general, deaf participants' performances are comparable to those of RA and differ from those of CA. Results are discussed within the framework of the study of phonology in deaf readers and its relation to reading acquisition. PMID:22410432

  5. Estimating Causal Effects from Multilevel Group-Allocation Data

    ERIC Educational Resources Information Center

    Gitelman, Alix I.

    2005-01-01

    In group-allocation studies for comparing behavioral, social, or educational interventions, subjects in the same group necessarily receive the same treatment, whereby a group and/or group-dynamic effect can confound the treatment effect. General counterfactual outcomes that depend on group characteristics, group membership, and treatment are…

  6. 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.

  7. The effect of goal setting on group performance: a meta-analysis.

    PubMed

    Kleingeld, Ad; van Mierlo, Heleen; Arends, Lidia

    2011-11-01

    Updating and extending the work of O'Leary-Kelly, Martocchio, and Frink (1994), with this meta-analysis on goal setting and group performance we show that specific difficult goals yield considerably higher group performance compared with nonspecific goals (d = 0.80 ± 0.35, k = 23 effect sizes). Moderately difficult and easy goals were also associated with performance benefits relative to nonspecific goals, but these effects were smaller. The overall effect size for all group goals was d = 0.56 ± 0.19 (k = 49). Unexpectedly, task interdependence, task complexity, and participation did not moderate the effect of group goals. Our inventory of multilevel goals in interdependent groups indicated that the effect of individual goals in groups on group performance was contingent upon the focus of the goal: "Egocentric" individual goals, aimed at maximizing individual performance, yielded a particularly negative group-performance effect (d = -1.75 ± 0.60, k = 6), whereas "groupcentric" goals, aimed at maximizing the individual contribution to the group's performance, showed a positive effect (d = 1.20 ± 1.03, k = 4). These findings demonstrate that group goals have a robust effect on group performance. Individual goals can also promote group performance but should be used with caution in interdependent groups. Future research might explore the role of multilevel goals for group performance in more detail. The striking lack of recent field studies in organizational settings that emerged from our brief review of trends in group goal-setting research should be taken into account when designing future studies in this domain.

  8. 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.

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

    PubMed

    Mark, B

    1985-06-01

    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.

  10. 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…

  11. Dictogloss: Is It an Effective Language Learning Task?

    ERIC Educational Resources Information Center

    Nabei, Toshiyo

    1996-01-01

    A study examined second language learners' interaction in the interaction stage of dictogloss to see how it might facilitate language learning. Dictogloss, a class activity, involves the teacher reading a passage aloud in class at natural speed, students taking notes for reconstruction, and students producing, in pairs or small groups, their own…

  12. Effects of Physical Exercise Interventions on Gait-Related Dual-Task Interference in Older Adults: A Systematic Review and Meta-Analysis.

    PubMed

    Plummer, Prudence; Zukowski, Lisa A; Giuliani, Carol; Hall, Amber M; Zurakowski, David

    2015-01-01

    Dual-task interference during walking can substantially limit mobility and increase the risk of falls among community-dwelling older adults. Previous systematic reviews examining intervention effects on dual-task gait and mobility have not assessed relative dual-task costs (DTC) or investigated whether there are differences in treatment-related changes based on the type of dual task or the type of control group. The purpose of this systematic review was to examine the effects of physical exercise interventions on dual-task performance during walking in older adults. A meta-analysis of randomized controlled trials (RCTs) compared treatment effects between physical exercise intervention and control groups on single- and dual-task gait speed and relative DTC on gait speed. A systematic search of the literature was conducted using the electronic databases PubMed, CINAHL, EMBASE, Web of Science, and PsycINFO searched up to September 19, 2014. Randomized, nonrandomized, and uncontrolled studies published in English and involving older adults were selected. Studies had to include a physical exercise intervention protocol and measure gait parameters during continuous, unobstructed walking in single- and dual-task conditions before and after the intervention. Of 614 abstracts, 21 studies met the inclusion criteria and were included in the systematic review. Fourteen RCTs were included in the meta-analysis. The mean difference between the intervention and control groups significantly favored the intervention for single-task gait speed (mean difference: 0.06 m/s, 95% CI: 0.03, 0.10, p < 0.001), dual-task gait speed (mean difference: 0.11 m/s, 95% CI 0.07, 0.15, p < 0.001), and DTC on gait speed (mean difference: 5.23%, 95% CI 1.40, 9.05, p = 0.007). Evidence from subgroup comparisons showed no difference in treatment-related changes between cognitive-motor and motor-motor dual tasks, or when interventions were compared to active or inactive controls. In summary, physical

  13. Effects of psychoactive drugs or stress on learning, memory, and performance as assessed using a novel water maze task.

    PubMed

    Kant, G J

    1993-02-01

    A novel water maze was used to assess the potential performance-disrupting effects of psychoactive drugs and stressors (4 mg/kg amphetamine sulfate; 1, 2, or 4 mg/kg diazepam; 30 mg/kg caffeine; 5 or 30 mg/kg atropine sulfate; 15 min of either intermittent foot-shock, forced running, or immobilization). The task utilized a traditional type of maze with walls and doorways set inside a pool. The apparatus could easily be reconfigured to present different mazes of approximately equal difficulty by opening or closing multiple doorways. Performance was measured by number of errors and time required to swim from the "start" to "finish" (a raised platform not in the rat's line of sight). After initial maze training, rats were divided into two groups. One group ran three daily trails through the same maze each day; this group was used to assess memory. The second group was challenged to swim three consecutive trials in a new maze configuration each day as a measure of learning. On any given day, rats from both groups received the same treatment. Drug or stress treatments were interspersed with vehicle or no-treatment trials days. The new maze task was more sensitive than the well-learned maze to the performance disrupting effects of amphetamine, caffeine, and diazepam, while atropine had no significant effect on performance on either maze. Foot-shock stress impaired performance on both mazes, while the other stressors had no significant effect.

  14. 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

  15. 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.

  16. 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

  17. The Effects of Art History-Enriched Art Therapy on Anxiety, Time on Task, and Art Product Quality.

    ERIC Educational Resources Information Center

    Miller, Carol L.

    1993-01-01

    Investigated effects of art history enrichment of art therapy task on anxiety, time on task, and art product quality among 13 chronic adult psychiatric day hospital patients. Results indicated art history enrichment task reduced anxiety and increased time on task. Art organization level tended toward significant increase compared with control…

  18. 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…

  19. 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…

  20. When Compatibility Interferes with Group Effectiveness: Facilitation of Learning in Small Groups.

    ERIC Educational Resources Information Center

    Shaw, Marvin, E.; Webb, Jeaninne N.

    1982-01-01

    Examined whether compatible groups facilitate learning more than incompatible groups. Used peer groups to facilitate learning in college courses. Computed compatibility scores for pairs and four-person groups working together. Used examinations to measure peer group procedure effectiveness. Results did not indicate a positive relationship between…

  1. A key role for experimental task performance: effects of math talent, gender and performance on the neural correlates of mental rotation.

    PubMed

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

    2012-02-01

    The neurophysiological mechanisms underlying superior cognitive performance are a research area of high interest. The majority of studies on the brain-performance relationship assessed the effects of capability-related group factors (e.g. talent, gender) on task-related brain activations while only few studies examined the effect of the inherent experimental task performance factor. In this functional MRI study, we combined both approaches and simultaneously assessed the effects of three relatively independent factors on the neurofunctional correlates of mental rotation in same-aged adolescents: math talent (gifted/controls: 17/17), gender (male/female: 16/18) and experimental task performance (median split on accuracy; high/low: 17/17). Better experimental task performance of mathematically gifted vs. control subjects and male vs. female subjects validated the selected paradigm. Activation of the inferior parietal lobule (IPL) was identified as a common effect of mathematical giftedness, gender and experimental task performance. However, multiple linear regression analyses (stepwise) indicated experimental task performance as the only predictor of parietal activations. In conclusion, increased activation of the IPL represents a positive neural correlate of mental rotation performance, irrespective of but consistent with the obtained neurocognitive and behavioral effects of math talent and gender. As experimental performance may strongly affect task-related activations this factor needs to be considered in capability-related group comparison studies on the brain-performance relationship.

  2. Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks

    PubMed Central

    de Hoyo, Moisés; Sañudo, Borja; Carrasco, Luis; Domínguez-Cobo, Sergio; Mateo-Cortes, Jesús; Cadenas-Sánchez, María Monserrat; Nimphius, Sophia

    2015-01-01

    This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years) volunteered to participate in this study. Participants were allocated into either the traditional training (TT) group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT) group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5–8 sets with 8 repetitions) and relative intensity (the load that maximized power (Pmax)) over the period of six weeks. Speed (10 m and 20 m), countermovement jump height (CMJH), 20 m change of direction ability (COD) and strength during a maximal voluntary isometric contraction (MVIC) were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004) was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: −0.17 0.27 s vs. HFT: −0.11 0.10 s), CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm) and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N) in both groups (p < 0.05). However, significant differences only occurred in the 20 m sprint time in the TT group (−0.04 0.12 s; p = 0.04). In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance. PMID:26557200

  3. Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks.

    PubMed

    de Hoyo, Moisés; Sañudo, Borja; Carrasco, Luis; Domínguez-Cobo, Sergio; Mateo-Cortes, Jesús; Cadenas-Sánchez, María Monserrat; Nimphius, Sophia

    2015-09-29

    This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years) volunteered to participate in this study. Participants were allocated into either the traditional training (TT) group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT) group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5-8 sets with 8 repetitions) and relative intensity (the load that maximized power (Pmax)) over the period of six weeks. Speed (10 m and 20 m), countermovement jump height (CMJH), 20 m change of direction ability (COD) and strength during a maximal voluntary isometric contraction (MVIC) were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004) was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: -0.17 0.27 s vs. HFT: -0.11 0.10 s), CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm) and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N) in both groups (p < 0.05). However, significant differences only occurred in the 20 m sprint time in the TT group (-0.04 0.12 s; p = 0.04). In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance. PMID:26557200

  4. 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…

  5. 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…

  6. The effects of age and type of carrying task on lower extremity kinematics

    PubMed Central

    Gillette, Jason C.; Stevermer, Catherine A.; Miller, Ross H.; Meardon, Stacey A.; Schwab, Charles V.

    2009-01-01

    The purpose of this study was to determine the effects of age, load amount, and load symmetry on lower extremity kinematics during carrying tasks. Forty-two participants in four age groups (8-10 years, 12-14 years, 15-17 years, and adults) carried loads of 0%, 10%, and 20% body weight (BW) in large or small buckets unilaterally and bilaterally. Reflective markers were tracked to determine total joint ROM and maximum joint angles during the stance phase of walking. Maximum hip extension, hip adduction, and hip internal rotation angles were significantly greater for each of the child/adolescent age groups as compared to adults. In addition, maximum hip internal rotation angles significantly increased when carrying a 20% BW load. The observation that the 8-10 year old age group carried the lightest absolute loads and still displayed the highest maximum hip internal rotation angles suggests a particular necessity in setting carrying guidelines for the youngest children. PMID:20191410

  7. Comparing the Frequency Effect Between the Lexical Decision and Naming Tasks in Chinese.

    PubMed

    Gao, Xin-Yu; Li, Meng-Feng; Chou, Tai-Li; Wu, Jei-Tun

    2016-01-01

    In psycholinguistic research, the frequency effect can be one of the indicators for eligible experimental tasks that examine the nature of lexical access. Usually, only one of those tasks is chosen to examine lexical access in a study. Using two exemplar experiments, this paper introduces an approach to include both the lexical decision task and the naming task in a study. In the first experiment, the stimuli were Chinese characters with frequency and regularity manipulated. In the second experiment, the stimuli were switched to Chinese two-character words, in which the word frequency and the regularity of the leading character were manipulated. The logic of these two exemplar experiments was to explore some important issues such as the role of phonology on recognition by comparing the frequency effect between both the tasks. The results revealed different patterns of lexical access from those reported in the alphabetic systems. The results of Experiment 1 manifested a larger frequency effect in the naming task as compared to the LDT, when the stimuli were Chinese characters. And it is noteworthy that, in Experiment 1, when the stimuli were regular Chinese characters, the frequency effect observed in the naming task was roughly equivalent to that in the LDT. However, a smaller frequency effect was shown in the naming task as compared to the LDT, when the stimuli were switched to Chinese two-character words in Experiment 2. Taking advantage of the respective demands and characteristics in both tasks, researchers can obtain a more complete and precise picture of character/word recognition. PMID:27077703

  8. Improving work group decision-making effectiveness.

    PubMed

    Schoonover-Shoffner, K

    1989-01-01

    Many of the decisions in complex health care organizations are made by small work groups. Nurse administrators often lead or are highly involved in these groups, where reaching quality decisions is a critical goal. This paper examines research and information from the communications field, presenting a model for making decisions in small groups. The author identifies common pitfalls of decision-making groups and presents strategies for problem solving and improved decision making.

  9. 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…

  10. A group-based tasks allocation algorithm for the optimization of long leave opportunities in academic departments

    NASA Astrophysics Data System (ADS)

    Eyono Obono, S. D.; Basak, Sujit Kumar

    2011-12-01

    The general formulation of the assignment problem consists in the optimal allocation of a given set of tasks to a workforce. This problem is covered by existing literature for different domains such as distributed databases, distributed systems, transportation, packets radio networks, IT outsourcing, and teaching allocation. This paper presents a new version of the assignment problem for the allocation of academic tasks to staff members in departments with long leave opportunities. It presents the description of a workload allocation scheme and its algorithm, for the allocation of an equitable number of tasks in academic departments where long leaves are necessary.

  11. Enhancing the Effectiveness of Work Groups and Teams.

    PubMed

    Kozlowski, Steve W J; Ilgen, Daniel R

    2006-12-01

    Teams of people working together for a common purpose have been a centerpiece of human social organization ever since our ancient ancestors first banded together to hunt game, raise families, and defend their communities. Human history is largely a story of people working together in groups to explore, achieve, and conquer. Yet, the modern concept of work in large organizations that developed in the late 19th and early 20th centuries is largely a tale of work as a collection of individual jobs. A variety of global forces unfolding over the last two decades, however, has pushed organizations worldwide to restructure work around teams, to enable more rapid, flexible, and adaptive responses to the unexpected. This shift in the structure of work has made team effectiveness a salient organizational concern. Teams touch our lives everyday and their effectiveness is important to well-being across a wide range of societal functions. There is over 50 years of psychological research-literally thousands of studies-focused on understanding and influencing the processes that underlie team effectiveness. Our goal in this monograph is to sift through this voluminous literature to identify what we know, what we think we know, and what we need to know to improve the effectiveness of work groups and teams. We begin by defining team effectiveness and establishing the conceptual underpinnings of our approach to understanding it. We then turn to our review, which concentrates primarily on topics that have well-developed theoretical and empirical foundations, to ensure that our conclusions and recommendations are on firm footing. Our review begins by focusing on cognitive, motivational/affective, and behavioral team processes-processes that enable team members to combine their resources to resolve task demands and, in so doing, be effective. We then turn our attention to identifying interventions, or "levers," that can shape or align team processes and thereby provide tools and

  12. 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.

  13. Cerebral mechanisms underlying the effects of music during a fatiguing isometric ankle-dorsiflexion task.

    PubMed

    Bigliassi, Marcelo; Karageorghis, Costas I; Nowicky, Alexander V; Orgs, Guido; Wright, Michael J

    2016-10-01

    The brain mechanisms by which music-related interventions ameliorate fatigue-related symptoms during the execution of fatiguing motor tasks are hitherto under-researched. The objective of the present study was to investigate the effects of music on brain electrical activity and psychophysiological measures during the execution of an isometric fatiguing ankle-dorsiflexion task performed until the point of volitional exhaustion. Nineteen healthy participants performed two fatigue tests at 40% of maximal voluntary contraction while listening to music or in silence. Electrical activity in the brain was assessed by use of a 64-channel EEG. The results indicated that music downregulated theta waves in the frontal, central, and parietal regions of the brain during exercise. Music also induced a partial attentional switching from associative thoughts to task-unrelated factors (dissociative thoughts) during exercise, which led to improvements in task performance. Moreover, participants experienced a more positive affective state while performing the isometric task under the influence of music.

  14. Task difficulty moderates implicit fear and anger effects on effort-related cardiac response.

    PubMed

    Chatelain, Mathieu; Silvestrini, Nicolas; Gendolla, Guido H E

    2016-03-01

    Based on the implicit-affect-primes-effort (IAPE) model (Gendolla, 2012, 2015), the present experiment tested whether objective task difficulty moderates the previously found impact of fear and anger primes on effort-related cardiac response during an arithmetic task. We expected that fear primes would lead to stronger cardiac pre-ejection period (PEP) reactivity than anger primes in an easy task, but that anger primes would lead to a stronger PEP response than fear primes in a difficult task. Results corroborated these predictions. Moreover, there was no evidence that the affect primes induced conscious feelings that could explain the observed cardiac reactivity, suggesting that the primes had the intended implicit effect on effort mobilization. The findings contribute to the accumulating evidence in support of the IAPE model, showing that objective task difficulty is a moderator of implicit affect's influence on effort-related cardiac response.

  15. Verification of monitor unit calculations for non-IMRT clinical radiotherapy: Report of AAPM Task Group 114

    SciTech Connect

    Stern, Robin L.; Heaton, Robert; Fraser, Martin W.; and others

    2011-01-15

    The requirement of an independent verification of the monitor units (MU) or time calculated to deliver the prescribed dose to a patient has been a mainstay of radiation oncology quality assurance. The need for and value of such a verification was obvious when calculations were performed by hand using look-up tables, and the verification was achieved by a second person independently repeating the calculation. However, in a modern clinic using CT/MR/PET simulation, computerized 3D treatment planning, heterogeneity corrections, and complex calculation algorithms such as convolution/superposition and Monte Carlo, the purpose of and methodology for the MU verification have come into question. In addition, since the verification is often performed using a simpler geometrical model and calculation algorithm than the primary calculation, exact or almost exact agreement between the two can no longer be expected. Guidelines are needed to help the physicist set clinically reasonable action levels for agreement. This report addresses the following charges of the task group: (1) To re-evaluate the purpose and methods of the ''independent second check'' for monitor unit calculations for non-IMRT radiation treatment in light of the complexities of modern-day treatment planning. (2) To present recommendations on how to perform verification of monitor unit calculations in a modern clinic. (3) To provide recommendations on establishing action levels for agreement between primary calculations and verification, and to provide guidance in addressing discrepancies outside the action levels. These recommendations are to be used as guidelines only and shall not be interpreted as requirements.

  16. Verification of monitor unit calculations for non-IMRT clinical radiotherapy: report of AAPM Task Group 114.

    PubMed

    Stern, Robin L; Heaton, Robert; Fraser, Martin W; Goddu, S Murty; Kirby, Thomas H; Lam, Kwok Leung; Molineu, Andrea; Zhu, Timothy C

    2011-01-01

    The requirement of an independent verification of the monitor units (MU) or time calculated to deliver the prescribed dose to a patient has been a mainstay of radiation oncology quality assurance. The need for and value of such a verification was obvious when calculations were performed by hand using look-up tables, and the verification was achieved by a second person independently repeating the calculation. However, in a modern clinic using CT/MR/PET simulation, computerized 3D treatment planning, heterogeneity corrections, and complex calculation algorithms such as convolution/superposition and Monte Carlo, the purpose of and methodology for the MU verification have come into question. In addition, since the verification is often performed using a simpler geometrical model and calculation algorithm than the primary calculation, exact or almost exact agreement between the two can no longer be expected. Guidelines are needed to help the physicist set clinically reasonable action levels for agreement. This report addresses the following charges of the task group: (1) To re-evaluate the purpose and methods of the "independent second check" for monitor unit calculations for non-IMRT radiation treatment in light of the complexities of modern-day treatment planning. (2) To present recommendations on how to perform verification of monitor unit calculations in a modern clinic. (3) To provide recommendations on establishing action levels for agreement between primary calculations and verification, and to provide guidance in addressing discrepancies outside the action levels. These recommendations are to be used as guidelines only and shall not be interpreted as requirements.

  17. 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

  18. Prospective Memory in Young and Older Adults: The Effects of Ongoing-Task Load

    PubMed Central

    Smith, Rebekah E.; Horn, Sebastian S.; Bayen, Ute J.

    2012-01-01

    Prospective memory involves remembering to perform intended actions in the future. Previous work with the multinomial model of event-based prospective memory indicated that adult age-related differences in prospective-memory performance were due to the prospective (not the retrospective) component of the task (Smith & Bayen, 2006). However, ongoing-task performance was also lower in older adults in that study. In the current study with young and older adults, the difficulty of the ongoing task was manipulated by varying the number of colors per trial to create easier and harder versions of the ongoing task for each age group. The easier version included 2 colors per trial for older adults and 4 colors for young adults. The harder version included 4 colors for older adults and 6 colors for young adults. By adjusting the ongoing-task difficulty, older adults were able to perform the ongoing task as well or better than the young adults. Analyses with the multinomial model revealed that making the ongoing task easier for older adults (or more difficult for young adults) did not eliminate age-related differences in prospective-memory performance and the underlying prospective component. PMID:22182306

  19. 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

  20. Task breakdown

    NASA Technical Reports Server (NTRS)

    Pavlich, Jane

    1990-01-01

    The topics concerning the Center for Space Construction (CSC) space construction breakdown structure are presented in viewgraph form. It is concluded that four components describe a task -- effecting, information gathering, analysis, and regulation; uncertainties effect the relative amount of information gathering and analysis that occurs; and that task timing requirements drive the 'location in time' of cognition.

  1. Motoneuronal TASK channels contribute to immobilizing effects of inhalational general anesthetics

    PubMed Central

    Lazarenko, Roman M.; Willcox, Sarah C.; Shu, Shaofang; Berg, Allison P.; Jevtovic-Todorovic, Vesna; Talley, Edmund M.; Chen, Xiangdong; Bayliss, Douglas A.

    2010-01-01

    General anesthetics cause sedation, hypnosis and immobilization via central nervous system mechanisms that remain incompletely understood; contributions of particular anesthetic targets in specific neural pathways remain largely unexplored. Among potential molecular targets for mediating anesthetic actions, the TASK subgroup (TASK-1, K2P3.1& TASK-3, K2P9.1) of background K+ channels are appealing candidates since they are expressed in CNS sites relevant to anesthetic actions and activated by clinically relevant concentrations of inhaled anesthetics. Here, we used global and conditional TASK channel single and double subunit knockout mice to demonstrate definitively that TASK channels account for motoneuronal anesthetic-activated K+ currents and to test their contributions to sedative, hypnotic and immobilizing anesthetic actions. In motoneurons from all knockout mice lines, TASK-like currents were reduced and cells were less sensitive to hyperpolarizing effects of halothane and isoflurane. In an immobilization assay, higher concentrations of both halothane and isoflurane were required to render TASK knockout animals unresponsive to a tail pinch; in assays of sedation (loss of movement) and hypnosis (loss-of-righting reflex), TASK knockout mice showed a modest decrease in sensitivity, and only for halothane. In conditional knockout mice, with TASK channel deletion restricted to cholinergic neurons, immobilizing actions of the inhaled anesthetics and sedative effects of halothane were reduced to the same extent as in global knockout lines. These data indicate that TASK channels in cholinergic neurons are a molecular substrate for select actions of inhaled anesthetics; for immobilization, which is spinally mediated, these data implicate motoneurons as the likely neuronal substrate. PMID:20519544

  2. 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.

  3. 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

  4. Effects of Emotion and Age on Performance During a Think/No-Think Memory Task

    PubMed Central

    Murray, Brendan D.; Muscatell, Keely A.; Kensinger, Elizabeth A.

    2011-01-01

    Recent studies have demonstrated that young adults can voluntarily suppress information from memory when directed to. After learning novel word pairings to criterion, participants are shown individual words and instructed either to “think” about the associated word, or to put it out of mind entirely (“no-think”). When given a surprise cued recall test, participants typically show impaired recall for “no-think” words relative to “think” or “control” (un-manipulated) words. The present study investigated whether this controlled suppression effect persists in an aged population, and examined how the emotionality of the to-be-suppressed word affects suppression ability. Data from four experiments using the think/no-think task demonstrate that older and younger adults can suppress information when directed to (Experiment 1), and the age groups do not differ significantly in this ability. Experiments 2 through 4 demonstrate that both age groups can suppress words that are emotional (positive or negative valence) or neutral. The suppression effect also persists even if participants are tested using independent probe words that are semantically related to the target words but were not the studied cue words (Experiments 3 and 4). These data suggest that the cognitive functioning necessary to suppress information from memory is present in older adulthood, and that both emotional and neutral information can be successfully suppressed from memory. PMID:21517183

  5. Task dependent lexicality effects support interactive models of reading: a meta-analytic neuroimaging review.

    PubMed

    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.

  6. Moving your eyes to solution: effects of movements on the perception of a problem-solving task.

    PubMed

    Werner, K; Raab, M

    2014-01-01

    There is ample evidence suggesting a bidirectional connection between bodily movements and cognitive processes, such as problem solving. Current research suggests that previous movements can influence the problem-solving process, but it is unclear what phase of this process is affected. Therefore, we investigated participants' gaze behaviour in the first phase of arithmetic problem solving with two groups (plus group, minus group) to explore a spatial bias toward the left or the right while perceiving a problem-solving task (the water-jar problem) after two different movements-that is, for the plus group, sorting marbles from two outer bowls into one in the middle, and for the minus group, sorting marbles from the middle bowl to the outer ones. We showed a right shift of spatial bias for the plus and to the left for the minus group in the perception and problem tasks. Although movements affected gaze, the groups did not differ in their overall problem-solving strategies; however, the first correct solutions did differ. This study provides further evidence of sensorimotor effects on problem solving and spatial bias and offers insight into how a two-phase problem-solving process is guided by sensorimotor information.

  7. 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…

  8. Effects of Self-Esteem and Perceived Goal Difficulty on Goal Setting, Certainty, Task Performance, and Attributions.

    ERIC Educational Resources Information Center

    Tang, Thomas Li-Ping; Reynolds, David B.

    1993-01-01

    Fifty-two subjects competed on a task against themselves, a difficult competitor, and an easy competitor. Certainty, ability attribution, and task satisfaction for those with low self-esteem were affected by perceived goal difficulty but not for those with high self-esteem. Low self-esteem groups had lower goals, certainty, and task performance.…

  9. 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.

  10. Driver distraction: the effects of concurrent in-vehicle tasks, road environment complexity and age on driving performance.

    PubMed

    Horberry, Tim; Anderson, Janet; Regan, Michael A; Triggs, Thomas J; Brown, John

    2006-01-01

    This paper presents the findings of a simulator study that examined the effects of distraction upon driving performance for drivers in three age groups. There were two in-vehicle distracter tasks: operating the vehicle entertainment system and conducting a simulated hands-free mobile phone conversation. The effect of visual clutter was examined by requiring participants to drive in simple and complex road environments. Overall measures of driving performance were collected, together with responses to roadway hazards and subjective measures of driver perceived workload. The two in-vehicle distraction tasks degraded overall driving performance, degraded responses to hazards and increased subjective workload. The performance decrements that occurred as a result of in-vehicle distraction were observed in both the simple and complex highway environments and for drivers in different age groups. One key difference was that older drivers traveled at lower mean speeds in the complex highway environment compared with younger drivers. The conclusions of the research are that both in-vehicle tasks impaired several aspects of driving performance, with the entertainment system distracter having the greatest negative impact on performance, and that these findings were relatively stable across different driver age groups and different environmental complexities. PMID:16226211

  11. 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

  12. Some Differential Effects of Two Training Group Styles.

    ERIC Educational Resources Information Center

    Boller, Jon D.

    Concurrent with the increasing interest in the training group (T-Group) as a source of growth and personal awareness for its participants, is a need to examine the effects of the T-group on certain personality types. This paper presents a rationale for examining the effects of the T-group on introverts and extroverts. Two T-group styles were…

  13. Aversive picture processing: effects of a concurrent task on sustained defensive system engagement.

    PubMed

    Wangelin, Bethany C; Löw, Andreas; McTeague, Lisa M; Bradley, Margaret M; Lang, Peter J

    2011-01-01

    Viewing a series of aversive pictures prompts emotional reactivity reflecting sustained defensive engagement. The present study examined the effects of a concurrent visual task on autonomic, somatic, electrocortical, and facial components of this defensive state. Results indicated that emotional activation was largely preserved despite continuous visual distraction, although evidence of attenuation was observed in startle reflex and electrocortical measures. Concurrent task-specific reactivity was also apparent, suggesting that motivational circuits can be simultaneously activated by stimuli with intrinsic survival significance and instructed task significance and that these processes interact differently across the separate components of defensive engagement.

  14. 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

  15. 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

  16. 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.

  17. Memory under pressure: secondary-task effects on contextual cueing of visual search.

    PubMed

    Annac, Efsun; Manginelli, Angela A; Pollmann, Stefan; Shi, Zhuanghua; Müller, Hermann J; Geyer, Thomas

    2013-11-04

    Repeated display configurations improve visual search. Recently, the question has arisen whether this contextual cueing effect (Chun & Jiang, 1998) is itself mediated by attention, both in terms of selectivity and processing resources deployed. While it is accepted that selective attention modulates contextual cueing (Jiang & Leung, 2005), there is an ongoing debate whether the cueing effect is affected by a secondary working memory (WM) task, specifically at which stage WM influences the cueing effect: the acquisition of configural associations (e.g., Travis, Mattingley, & Dux, 2013) versus the expression of learned associations (e.g., Manginelli, Langer, Klose, & Pollmann, 2013). The present study re-investigated this issue. Observers performed a visual search in combination with a spatial WM task. The latter was applied on either early or late search trials--so as to examine whether WM load hampers the acquisition of or retrieval from contextual memory. Additionally, the WM and search tasks were performed either temporally in parallel or in succession--so as to permit the effects of spatial WM load to be dissociated from those of executive load. The secondary WM task was found to affect cueing in late, but not early, experimental trials--though only when the search and WM tasks were performed in parallel. This pattern suggests that contextual cueing involves a spatial WM resource, with spatial WM providing a workspace linking the current search array with configural long-term memory; as a result, occupying this workspace by a secondary WM task hampers the expression of learned configural associations.

  18. Collaboration or Confrontation? An Investigation into the Role of Prior Experiences in the Completion of Collaborative Group Tasks by Student Teachers

    ERIC Educational Resources Information Center

    Crichton, Hazel; Templeton, Brian

    2013-01-01

    This paper describes research which investigated how a group of 23 postgraduate student teachers from a wide variety of international backgrounds with a broad range of previous experience perceived the significance of their own and others' prior experience in accomplishing directed collaborative tasks, related to their coursework, in…

  19. 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

  20. 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…