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Sample records for detailed function task

  1. Crucial role of detailed function, task, timeline, link and human vulnerability analyses in HRA

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, T.G.; Haney, L.N.; Ostrom, L.T.

    1992-10-01

    This paper addresses one major cause for large uncertainties in human reliability analysis (HRA) results, that is, an absence of detailed function, task, timeline, link and human vulnerability analyses. All too often this crucial step in the HRA process is done in a cursory fashion using word of mouth or written procedures which themselves may incompletely or inaccurately represent the human action sequences and human error vulnerabilities being analyzed. The paper examines the potential contributions these detailed analyses can make in achieving quantitative and qualitative HRA results which are: (1) creditable, that is, minimize uncertainty, (2) auditable, that is, systematically linking quantitative results and qualitative information from which the results are derived, (3) capable of supporting root cause analyses on human reliability factors determined to be major contributors to risk, and (4) capable of repeated measures and being combined with similar results from other analyses to examine HRA issues transcending individual systems and facilities. Based on experience analyzing test and commercial nuclear reactors, and medical applications of nuclear technology, an iterative process is suggested for doing detailed function, task, timeline, link and human vulnerability analyses using documentation reviews, open-ended and structured interviews, direct observations, and group techniques. Finally, the paper concludes that detailed analyses done in this manner by knowledgeable human factors practitioners, can contribute significantly to the credibility, auditability, causal factor analysis, and combining goals of the HRA.

  2. Crucial role of detailed function, task, timeline, link and human vulnerability analyses in HRA. [Human Reliability Analysis (HRA)

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, T.G.; Haney, L.N.; Ostrom, L.T.

    1992-01-01

    This paper addresses one major cause for large uncertainties in human reliability analysis (HRA) results, that is, an absence of detailed function, task, timeline, link and human vulnerability analyses. All too often this crucial step in the HRA process is done in a cursory fashion using word of mouth or written procedures which themselves may incompletely or inaccurately represent the human action sequences and human error vulnerabilities being analyzed. The paper examines the potential contributions these detailed analyses can make in achieving quantitative and qualitative HRA results which are: (1) creditable, that is, minimize uncertainty, (2) auditable, that is, systematically linking quantitative results and qualitative information from which the results are derived, (3) capable of supporting root cause analyses on human reliability factors determined to be major contributors to risk, and (4) capable of repeated measures and being combined with similar results from other analyses to examine HRA issues transcending individual systems and facilities. Based on experience analyzing test and commercial nuclear reactors, and medical applications of nuclear technology, an iterative process is suggested for doing detailed function, task, timeline, link and human vulnerability analyses using documentation reviews, open-ended and structured interviews, direct observations, and group techniques. Finally, the paper concludes that detailed analyses done in this manner by knowledgeable human factors practitioners, can contribute significantly to the credibility, auditability, causal factor analysis, and combining goals of the HRA.

  3. Student Assessment System. Student Performance Record. Task Detailing. Allied Health Occupations/Practical Nursing. Georgia Vocational Education Program Articulation.

    Science.gov (United States)

    Georgia Univ., Athens. Div. of Vocational Education.

    This booklet lists tasks and functions the health occupations student should be able to do upon entering an employment situation or a postsecondary school. (Listings are also available for the areas of cosmetology and transportation/automotive mechanics.) Tasks are coded to correspond to those on the Student Performance Record, which details a…

  4. Functional Task Test: Data Review

    Science.gov (United States)

    Cromwell, Ronita

    2014-01-01

    After space flight there are changes in multiple physiological systems including: Cardiovascular function; Sensorimotor function; and Muscle function. How do changes in these physiological system impact astronaut functional performance?

  5. Student Assessment System. Student Performance Record. Task Detailing. Cosmetology. Georgia Vocational Education Program Articulation.

    Science.gov (United States)

    Georgia Univ., Athens. Div. of Vocational Education.

    This booklet lists tasks and functions the cosmetology student should be able to do upon entering an employment situation or a postsecondary school. (Listings are also available for the areas of allied health occupations/practical nursing and transportation/automotive mechanics.) Tasks are coded to correspond to those on the Student Performance…

  6. Functional Task Test: 2. Spaceflight-Induced Cardiovascular Change and Recovery During NASA's Functional Task Test

    Science.gov (United States)

    Phillips, Tiffany; Arzeno, Natalia M.; Stenger, Michael; Lee, Stuart M. C.; Bloomberg, Jacob J.; Platts, Steven H.

    2011-01-01

    The overall objective of the functional task test (FTT) is to correlate spaceflight-induced physiological adaptations with changes in performance of high priority exploration mission-critical tasks. This presentation will focus on the recovery from fall/stand test (RFST), which measures the cardiovascular response to the transition from the prone posture (simulated fall) to standing in normal gravity, as well as heart rate (HR) during 11 functional tasks. As such, this test describes some aspects of spaceflight-induced cardiovascular deconditioning and the course of recovery in Space Shuttle and International Space Station (ISS) astronauts. The sensorimotor and neuromuscular components of the FTT are described in two separate abstracts: Functional Task Test 1 and 3.

  7. Functional Task Test: 1. Sensorimotor changes Associated with Postflight Alterations in Astronaut Functional Task Performance

    Science.gov (United States)

    Bloomberg, J. J.; Arzeno, N. H.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Platts, S. H.; Peters, B. T.; Phillips, T.; Ploutz-Snyder, L. L.; Reschke, M. F.; Ryder, J. W.; Spiering, B. A.; Stenger, M. B.; Taylor, L. C.; Wickwire, P. J.; Wood, S. J.

    2011-01-01

    Space flight is known to cause alterations in multiple physiological systems including changes in sensorimotor, cardiovascular, and neuromuscular systems. These changes may affect a crewmember s ability to perform critical mission tasks immediately after landing on a planetary surface. The overall goal of this project is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. This presentation will focus on the sensorimotor contributions to postflight functional performance.

  8. Detailed Measurements of Structure Functions from Nucleons and Nuclei

    CERN Multimedia

    2002-01-01

    The experiment will study deep inelastic muon nucleon scattering in a wide range of Q|2~(1-200 (GeV/c)|2) and x~(0.005-0.75). The main aims of the experiment are: \\item a)~~~~Detailed measurements of the nuclear dependence of the structure function F^2|A, of R~=~@s^L/@s^T and of the cross-section for J/@y production. They will provide a basis for the understanding of the EMC effect: the modification of quark and gluon distributions due to the nuclear environment. \\item b)~~~~A simultaneous high luminosity measurement of the structure function F^2 on hydrogen and deuterium. This will provide substantially improved accuracy in the knowledge of the neutron structure function F^2|n, of F^2|p-F^2|n and F^2|n/F^2|p and their Q|2 dependence. Furthermore, the data will allow a determination of the strong coupling constant @a^s(Q|2) with reduced experimental and theoretical uncertainties as well as of the ratio of the down to up quark distributions in the valence region. Due to the large x range covered by the experim...

  9. The Ministry of Industry and Information Technology Issued Detail Breakdown on the Tasks to Eliminate 2009 Backward Production Capacity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ In order to implement the spirit of "The Announcement from the State Council about Issuing the 2009 Work Plan on Energy-Saving and Emission-Reduction" and the adjustment and revitalization plan for key industries, and further improve the work to eliminate backward production capacity, the Ministry of Industry and Information Technology issued a notice on the detail breakdown and implementation of tasks to eliminate 2009 backward production capacity on November 25, 2009.

  10. The functional neuroanatomy of multitasking: combining dual tasking with a short term memory task.

    Science.gov (United States)

    Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan

    2013-09-01

    Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.

  11. The Effects of Seductive Details on Recognition Tests and Transfer Tasks

    Science.gov (United States)

    2008-06-01

    Educational psychology . Englewood Cliffs, NJ: Prentice Hall. Dewey, J. (1913). Interest and effort in education. New York: The Free Press. Donaldson, W... Educational Psychology , 89, 92-103. Harp, S. F., & Mayer, R. E. (1998). How seductive details do their damage: A theory of cognitive interest in science...learning. Journal of Educational Psychology , 90, 414-434. Hidi, S. (1990). Interest and its contribution as a mental resource for learning. Review of

  12. The shielding function of task rules in the context of task switching.

    Science.gov (United States)

    Reisenauer, Renate; Dreisbach, Gesine

    2014-02-01

    There is increasing evidence that task rules help shield the response against distractor interference. Here, the authors investigate the cognitive mechanisms underlying this assumed shielding function of task rules and how it is adjusted to changing task demands. In two experiments, participants switched between a noun categorization and an adjective categorization task. Target words were superimposed on distractor pictures. These pictures were always irrelevant and depicted either objects also used as target words in the noun task (noun distractors) or objects that were not part of the noun target-set but could be categorized according to the noun task (noun-related distractors). Results show that (a) on task repetitions shielding prevents interference from any distractors associated with a competing task; this is indicated by the lack of interference on adjective task repetitions; and (b) shielding is reduced on task switches. In the noun task, this reduction resulted in attenuated interference by noun-related distractors. In the adjective task, spatial distractors did not interfere despite the reduction. This result suggests that shielding is supported by a processing advantage for task-related information and not by distractor suppression.

  13. Characterization of task-free and task-performance brain states via functional connectome patterns.

    Science.gov (United States)

    Zhang, Xin; Guo, Lei; Li, Xiang; Zhang, Tuo; Zhu, Dajiang; Li, Kaiming; Chen, Hanbo; Lv, Jinglei; Jin, Changfeng; Zhao, Qun; Li, Lingjiang; Liu, Tianming

    2013-12-01

    Both resting state fMRI (R-fMRI) and task-based fMRI (T-fMRI) have been widely used to study the functional activities of the human brain during task-free and task-performance periods, respectively. However, due to the difficulty in strictly controlling the participating subject's mental status and their cognitive behaviors during R-fMRI/T-fMRI scans, it has been challenging to ascertain whether or not an R-fMRI/T-fMRI scan truly reflects the participant's functional brain states during task-free/task-performance periods. This paper presents a novel computational approach to characterizing and differentiating the brain's functional status into task-free or task-performance states, by which the functional brain activities can be effectively understood and differentiated. Briefly, the brain's functional state is represented by a whole-brain quasi-stable connectome pattern (WQCP) of R-fMRI or T-fMRI data based on 358 consistent cortical landmarks across individuals, and then an effective sparse representation method was applied to learn the atomic connectome patterns (ACPs) of both task-free and task-performance states. Experimental results demonstrated that the learned ACPs for R-fMRI and T-fMRI datasets are substantially different, as expected. A certain portion of ACPs from R-fMRI and T-fMRI data were overlapped, suggesting some subjects with overlapping ACPs were not in the expected task-free/task-performance brain states. Besides, potential outliers in the T-fMRI dataset were further investigated via functional activation detections in different groups, and our results revealed unexpected task-performances of some subjects. This work offers novel insights into the functional architectures of the brain.

  14. Photoelectric scanner makes detailed work function maps of metal surface

    Science.gov (United States)

    Rasor, N. S.

    1966-01-01

    Photoelectric scanning device maps the work function of a metal surface by scanning it with a light spot and measuring the resulting photocurrent. The device is capable of use over a range of surface temperatures.

  15. Man-machine Integration Design and Analysis System (MIDAS) Task Loading Model (TLM) experimental and software detailed design report

    Science.gov (United States)

    Staveland, Lowell

    1994-01-01

    This is the experimental and software detailed design report for the prototype task loading model (TLM) developed as part of the man-machine integration design and analysis system (MIDAS), as implemented and tested in phase 6 of the Army-NASA Aircrew/Aircraft Integration (A3I) Program. The A3I program is an exploratory development effort to advance the capabilities and use of computational representations of human performance and behavior in the design, synthesis, and analysis of manned systems. The MIDAS TLM computationally models the demands designs impose on operators to aide engineers in the conceptual design of aircraft crewstations. This report describes TLM and the results of a series of experiments which were run this phase to test its capabilities as a predictive task demand modeling tool. Specifically, it includes discussions of: the inputs and outputs of TLM, the theories underlying it, the results of the test experiments, the use of the TLM as both stand alone tool and part of a complete human operator simulation, and a brief introduction to the TLM software design.

  16. Assessing executive functions in preschoolers using Shape School Task

    Directory of Open Access Journals (Sweden)

    Marta Nieto

    2016-09-01

    Full Text Available Over the last two decades, there has been a growing interest in the study of the development of executive functions in preschool children due to their relationship with different cognitive, psychological, social and academic domains. Early detection of individual differences in executive functioning can have major implications for basic and applied research. Consequently, there is a key need for assessment tools adapted to preschool skills: Shape School has been shown to be a suitable task for this purpose. Our study uses Shape School as the main task to analyze development of inhibition, task-switching and working memory in a sample of 304 preschoolers (age range 3.25-6.50 years. Additionally, we include cognitive tasks for the evaluation of verbal variables (vocabulary, word reasoning and short-term memory and performance variables (picture completion and symbol search, so as to analyze their relationship with executive functions. Our results show age-associated improvements in executive functions and the cognitive variables assessed. Furthermore, correlation analyses reveal positive relationships between executive functions and the other cognitive variables. More specifically, using structural equation modeling and including age direct and indirect effects, our results suggest that executive functions explain to a greater extent performance on verbal and performance tasks. These findings provide further information to support research that considers preschool age to be a crucial period for the development of executive functions and their relationship with other cognitive processes

  17. TASK-2: a K2P K+ channel with complex regulation and diverse physiological functions

    Directory of Open Access Journals (Sweden)

    Luis Pablo Cid

    2013-07-01

    Full Text Available TASK-2 (K2P5.1 is a two-pore domain K+ channel belonging to the TALK subgroup of the K2P family of proteins. TASK-2 has been shown to be activated by extra- and intracellular alkalinisation. Extra- and intracellular pH-sensors reside at arginine 224 and lysine 245 and might affect separate selectivity filter and inner gates respectively. TASK-2 is modulated by changes in cell volume and a regulation by direct G-protein interaction has also been proposed. Activation by extracellular alkalinisation has been associated with a role of TASK-2 in kidney proximal tubule bicarbonate reabsorption, whilst intracellular pH-sensitivity might be the mechanism for its participation in central chemosensitive neurons. In addition to these functions TASK-2 has been proposed to play a part in apoptotic volume decrease in kidney cells and in volume regulation of glial cells and T-lymphocytes. TASK-2 is present in chondrocytes of hyaline cartilage, where it is proposed to play a central role in stabilizing the membrane potential. Additional sites of expression are dorsal root ganglion neurons, endocrine and exocrine pancreas and intestinal smooth muscle cells. TASK-2 has been associated with the regulation of proliferation of breast cancer cells and could become target for breast cancer therapeutics. Further work in native tissues and cells together with genetic modification will no doubt reveal the details of TASK-2 functions that we are only starting to suspect.

  18. Age-related changes in task related functional network connectivity.

    Directory of Open Access Journals (Sweden)

    Jason Steffener

    Full Text Available Aging has a multi-faceted impact on brain structure, brain function and cognitive task performance, but the interaction of these different age-related changes is largely unexplored. We hypothesize that age-related structural changes alter the functional connectivity within the brain, resulting in altered task performance during cognitive challenges. In this neuroimaging study, we used independent components analysis to identify spatial patterns of coordinated functional activity involved in the performance of a verbal delayed item recognition task from 75 healthy young and 37 healthy old adults. Strength of functional connectivity between spatial components was assessed for age group differences and related to speeded task performance. We then assessed whether age-related differences in global brain volume were associated with age-related differences in functional network connectivity. Both age groups used a series of spatial components during the verbal working memory task and the strength and distribution of functional network connectivity between these components differed across the age groups. Poorer task performance, i.e. slower speed with increasing memory load, in the old adults was associated with decreases in functional network connectivity between components comprised of the supplementary motor area and the middle cingulate and between the precuneus and the middle/superior frontal cortex. Advancing age also led to decreased brain volume; however, there was no evidence to support the hypothesis that age-related alterations in functional network connectivity were the result of global brain volume changes. These results suggest that age-related differences in the coordination of neural activity between brain regions partially underlie differences in cognitive performance.

  19. Task-related Functional Connectivity Dynamics in a Block-designed Visual Experiment

    Directory of Open Access Journals (Sweden)

    Xin eDi

    2015-09-01

    Full Text Available Studying task modulations of brain connectivity using functional magnetic resonance imaging (fMRI is critical to understand brain functions that support cognitive and affective processes. Existing methods such as psychophysiological interaction (PPI and dynamic causal modelling (DCM usually implicitly assume that the connectivity patterns are stable over a block-designed task with identical stimuli. However, this assumption lacks empirical verification on high-temporal resolution fMRI data with reliable data-driven analysis methods. The present study performed a detailed examination of dynamic changes of functional connectivity (FC in a simple block-designed visual checkerboard experiment with a sub-second sampling rate (TR = 0.645 s by estimating time-varying correlation coefficient (TVCC between BOLD responses of different brain regions. We observed reliable task-related FC changes (i.e., FCs were transiently decreased after task onset and went back to the baseline afterward among several visual regions of the bilateral middle occipital gyrus (MOG and the bilateral fusiform gyrus (FuG. Importantly, only the FCs between higher visual regions (MOG and lower visual regions (FuG exhibited such dynamic patterns. The results suggested that simply assuming a sustained FC during a task block may be insufficient to capture distinct task-related FC changes. The investigation of FC dynamics in tasks could improve our understanding of condition shifts and the coordination between different activated brain regions.

  20. Pediatric functional magnetic resonance neuroimaging: tactics for encouraging task compliance

    Directory of Open Access Journals (Sweden)

    Silk Jennifer S

    2011-05-01

    Full Text Available Abstract Background Neuroimaging technology has afforded advances in our understanding of normal and pathological brain function and development in children and adolescents. However, noncompliance involving the inability to remain in the magnetic resonance imaging (MRI scanner to complete tasks is one common and significant problem. Task noncompliance is an especially significant problem in pediatric functional magnetic resonance imaging (fMRI research because increases in noncompliance produces a greater risk that a study sample will not be representative of the study population. Method In this preliminary investigation, we describe the development and application of an approach for increasing the number of fMRI tasks children complete during neuroimaging. Twenty-eight healthy children ages 9-13 years participated. Generalization of the approach was examined in additional fMRI and event-related potential investigations with children at risk for depression, children with anxiety and children with depression (N = 120. Essential features of the approach include a preference assessment for identifying multiple individualized rewards, increasing reinforcement rates during imaging by pairing tasks with chosen rewards and presenting a visual 'road map' listing tasks, rewards and current progress. Results Our results showing a higher percentage of fMRI task completion by healthy children provides proof of concept data for the recommended tactics. Additional support was provided by results showing our approach generalized to several additional fMRI and event-related potential investigations and clinical populations. Discussion We proposed that some forms of task noncompliance may emerge from less than optimal reward protocols. While our findings may not directly support the effectiveness of the multiple reward compliance protocol, increased attention to how rewards are selected and delivered may aid cooperation with completing fMRI tasks Conclusion The

  1. Task modulates functional connectivity networks in free viewing behavior.

    Science.gov (United States)

    Seidkhani, Hossein; Nikolaev, Andrey R; Meghanathan, Radha Nila; Pezeshk, Hamid; Masoudi-Nejad, Ali; van Leeuwen, Cees

    2017-08-03

    In free visual exploration, eye-movement is immediately followed by dynamic reconfiguration of brain functional connectivity. We studied the task-dependency of this process in a combined visual search-change detection experiment. Participants viewed two (nearly) same displays in succession. First time they had to find and remember multiple targets among distractors, so the ongoing task involved memory encoding. Second time they had to determine if a target had changed in orientation, so the ongoing task involved memory retrieval. From multichannel EEG recorded during 200 ms intervals time-locked to fixation onsets, we estimated the functional connectivity using a weighted phase lag index at the frequencies of theta, alpha, and beta bands, and derived global and local measures of the functional connectivity graphs. We found differences between both memory task conditions for several network measures, such as mean path length, radius, diameter, closeness and eccentricity, mainly in the alpha band. Both the local and the global measures indicated that encoding involved a more segregated mode of operation than retrieval. These differences arose immediately after fixation onset and persisted for the entire duration of the lambda complex, an evoked potential commonly associated with early visual perception. We concluded that encoding and retrieval differentially shape network configurations involved in early visual perception, affecting the way the visual input is processed at each fixation. These findings demonstrate that task requirements dynamically control the functional connectivity networks involved in early visual perception. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Complete 3D kinematics of upper extremity functional tasks.

    Science.gov (United States)

    van Andel, Carolien J; Wolterbeek, Nienke; Doorenbosch, Caroline A M; Veeger, DirkJan H E J; Harlaar, Jaap

    2008-01-01

    Upper extremity (UX) movement analysis by means of 3D kinematics has the potential to become an important clinical evaluation method. However, no standardized protocol for clinical application has yet been developed, that includes the whole upper limb. Standardization problems include the lack of a single representative function, the wide range of motion of joints and the complexity of the anatomical structures. A useful protocol would focus on the functional status of the arm and particularly the orientation of the hand. The aim of this work was to develop a standardized measurement method for unconstrained movement analysis of the UX that includes hand orientation, for a set of functional tasks for the UX and obtain normative values. Ten healthy subjects performed four representative activities of daily living (ADL). In addition, six standard active range of motion (ROM) tasks were executed. Joint angles of the wrist, elbow, shoulder and scapula were analyzed throughout each ADL task and minimum/maximum angles were determined from the ROM tasks. Characteristic trajectories were found for the ADL tasks, standard deviations were generally small and ROM results were consistent with the literature. The results of this study could form the normative basis for the development of a 'UX analysis report' equivalent to the 'gait analysis report' and would allow for future comparisons with pediatric and/or pathologic movement patterns.

  3. Inverted-U Function Relating Cortical Plasticity and Task Difficulty

    Science.gov (United States)

    Engineer, Navzer D.; Engineer, Crystal T.; Reed, Amanda C.; Pandya, Pritesh K.; Jakkamsetti, Vikram; Moucha, Raluca; Kilgard, Michael P.

    2012-01-01

    Many psychological and physiological studies with simple stimuli have suggested that perceptual learning specifically enhances the response of primary sensory cortex to task-relevant stimuli. The aim of this study was to determine whether auditory discrimination training on complex tasks enhances primary auditory cortex responses to a target sequence relative to non-target and novel sequences. We collected responses from more than 2,000 sites in 31 rats trained on one of six discrimination tasks that differed primarily in the similarity of the target and distractor sequences. Unlike training with simple stimuli, long-term training with complex stimuli did not generate target specific enhancement in any of the groups. Instead, cortical receptive field size decreased, latency decreased, and paired pulse depression decreased in rats trained on the tasks of intermediate difficulty while tasks that were too easy or too difficult either did not alter or degraded cortical responses. These results suggest an inverted-U function relating neural plasticity and task difficulty. PMID:22249158

  4. Efficacy of Mirror Therapy Containing Functional Tasks in Poststroke Patients

    OpenAIRE

    Lim, Kil-Byung; Lee, Hong-Jae; Yoo, JeeHyun; Yun, Hyun-Ju; Hwang, Hye-Jung

    2016-01-01

    Objective To investigate the effect of mirror therapy containing functional tasks on upper extremity function and activities of daily living in patients with subacute stroke. Methods The subjects were randomly divided into two groups: the mirror therapy group (30 patients) and the sham therapy group (30 patients). The mirror therapy group underwent a mirror therapy program together with conventional therapy for 20 minutes per day on 5 days per week for 4 weeks. The control group received a sh...

  5. Task-related signal decrease on functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Yoshie; Nakamura, Mitsugu; Tamaki, Norihiko; Tamura, Shogo [Kobe Univ. (Japan). School of Medicine; Kitamura, Junji

    2001-10-01

    An atypical pattern of signal change was identified on functional magnetic resonance (fMR) imaging in pathologic patients. Three normal volunteers and 34 patients with pathologic lesions near the primary motor cortex underwent fMR imaging with echo-planar imaging while performing a hand motor task. Signal intensities were evaluated with the z-score method, and the time course and changes of the signal intensity were calculated. Nine of the 34 patients with pathologic lesions displayed a significant task-related signal reduction in motor-related areas. They also presented a conventional task-related signal increase in other motor-related areas. The time courses of the increase and decrease were the inverse of each other. There was no significant difference between rates of signal increase and decrease. Our findings suggest that this atypical signal decrease is clinically significant, and that impaired vascular reactivity and altered oxygen metabolism could contribute to the task-related signal reduction. Brain areas showing such task-related signal decrease should be preserved at surgery. (author)

  6. Hierarchical organization of brain functional network during visual task

    CERN Document Server

    Zhuo, Zhao; Fu, Zhong-Qian; Zhang, Jie

    2011-01-01

    In this paper, the brain functional networks derived from high-resolution synchronous EEG time series during visual task are generated by calculating the phase synchronization among the time series. The hierarchical modular organizations of these networks are systematically investigated by the fast Girvan-Newman algorithm. At the same time, the spatially adjacent electrodes (corresponding to EEG channels) are clustered into functional groups based on anatomical parcellation of brain cortex, and this clustering information are compared to that of the functional network. The results show that the modular architectures of brain functional network are in coincidence with that from the anatomical structures over different levels of hierarchy, which suggests that population of neurons performing the same function excite and inhibit in identical rhythms. The structure-function relationship further reveals that the correlations among EEG time series in the same functional group are much stronger than those in differe...

  7. Ability Beliefs, Task Value, and Performance as a Function of Race in a Dart-Throwing Task

    Science.gov (United States)

    Gao, Zan; Kosma, Maria; Harrison, Louis, Jr.

    2009-01-01

    This study examines differences in self-efficacy, expectancy-related beliefs, task value, and performance in a dart-throwing task as a function of race among diverse college students using the expectancy-value model and self-efficacy theory. It also examines the predictive contributions of these beliefs on task performance within each racial…

  8. Efficacy of Mirror Therapy Containing Functional Tasks in Poststroke Patients.

    Science.gov (United States)

    Lim, Kil-Byung; Lee, Hong-Jae; Yoo, Jeehyun; Yun, Hyun-Ju; Hwang, Hye-Jung

    2016-08-01

    To investigate the effect of mirror therapy containing functional tasks on upper extremity function and activities of daily living in patients with subacute stroke. The subjects were randomly divided into two groups: the mirror therapy group (30 patients) and the sham therapy group (30 patients). The mirror therapy group underwent a mirror therapy program together with conventional therapy for 20 minutes per day on 5 days per week for 4 weeks. The control group received a sham conventional therapy program under the same schedule as the mirror therapy group. The Fugl-Meyer Motor Function Assessment (FMA), Brunnstrom motor recovery stage, and Modified Barthel Index (MBI) were evaluated 4 weeks after the treatment. The upper extremity function on the affected side and ability to perform daily life activities after the intervention were significantly improved in both groups. After 4 weeks of intervention, improvements in the FMA (p=0.027) and MBI (p=0.041) were significantly greater in the mirror therapy group than the sham therapy group. In this study, we found that the mirror therapy containing functional task was effective in terms of improving the upper extremity functions and activities of daily living in patients with subacute stroke.

  9. Description of the detailed Functional Architecture of the Frequency and Voltage control solution (functional and information layer)

    DEFF Research Database (Denmark)

    Caerts, Chris; Rikos, Evangelos; Syed, Mazheruddin

    2017-01-01

    This D4.2 document provides the description of the detailed functional architecture of the selected solutions that will be implemented and tested. This is documented by combining a function-based IEC 62559 Use Case description with an SGAM mapping of these functions and the interactions among the...

  10. Aespoe modelling task force - experiences of the site specific flow and transport modelling (in detailed and site scale)

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden); Stroem, A.; Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co. , Stockholm (Sweden)

    1998-09-01

    The Aespoe Task Force on modelling of groundwater flow and transport of solutes was initiated in 1992. The Task Force shall be a forum for the organisations supporting the Aespoe Hard Rock Laboratory Project to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Much emphasis is put on building of confidence in the approaches and methods in use for modelling of groundwater flow and nuclide migration in order to demonstrate their use for performance and safety assessment. The modelling work within the Task Force is linked to the experiments performed at the Aespoe Laboratory. As the first Modelling Task, a large scale pumping and tracer experiment called LPT2 was chosen. This was the final part of the characterisation work for the Aespoe site before the construction of the laboratory in 1990. The construction of the Aespoe HRL access tunnel caused an even larger hydraulic disturbance on a much larger scale than that caused by the LPT2 pumping test. This was regarded as an interesting test case for the conceptual and numerical models of the Aespoe site developed during Task No 1, and was chosen as the third Modelling Task. The aim of Task 3 can be seen from two different perspectives. The Aespoe HRL project saw it as a test of their ability to define a conceptual and structural model of the site that can be utilised by independent modelling groups and be transformed to a predictive groundwater flow model. The modelling groups saw it as a means of understanding groundwater flow in a large fractured rock volume and of testing their computational tools. A general conclusion is that Task 3 has served these purposes well. Non-sorbing tracers tests, made as a part of the TRUE-experiments were chosen as the next predictive modelling task. A preliminary comparison between model predictions made by the Aespoe Task Force and the experimental results, shows that most modelling teams predicted breakthrough from

  11. Does the Iowa Gambling Task Measure Executive Function?

    Science.gov (United States)

    Gansler, David A.; Jerram, Matthew W.; Vannorsdall, Tracy D.; Schretlen, David J.

    2011-01-01

    The Iowa Gambling Task (IGT) is assumed to measure executive functioning, but this has not been empirically tested by means of both convergent and discriminant validity. We used structural equation modeling (SEM) to test whether the IGT is an executive function (EF) task (convergent validity) and whether it is not related to other neuropsychological domains (discriminant validity). Healthy community-dwelling participants (N = 214) completed a comprehensive neuropsychological battery. We analyzed the conventional IGT metric and three alternative metrics based on the overall difference of advantageous minus disadvantageous choices made during the last 60 IGT responses and advantageous minus disadvantageous choices based on two specific decks of cards (D minus A). An a priori six-factor hierarchical model of neuropsychological functioning was confirmed with SEM. Attention and processing speed were grouped as “non-associative” factors. Fluency, executive functioning, visual learning/memory, and verbal learning/memory were grouped as higher-level “associative” factors. Of the non-associative factors, attention, but not speed, predicted IGT performance. When each associative factor was entered along with attention, only EF improved the model fit and that was only for metrics based on trials 41–100. SEM indicates metrics based on trails 1–100 are influenced by attention, and metrics based on trails 41–100 are influenced by attention and EF. Its associative strength with attention is twice that of EF. Conceptually, the IGT is a multi-trait task involving novel problem-solving and attentional domains to a greater extent, and executive functioning to a lesser extent. PMID:22015855

  12. Electric Vehicle Preparedness Task 3: Detailed Assessment of Target Electrification Vehicles at Joint Base Lewis McChord Utilization

    Energy Technology Data Exchange (ETDEWEB)

    Schey, Stephen [Idaho National Lab. (INL), Idaho Falls, ID (United States); Francfort, Jim [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-08-01

    Task 2 involved identifying daily operational characteristics of select vehicles and initiating data logging of vehicle movements in order to characterize the vehicle’s mission. Individual observations of these selected vehicles provide the basis for recommendations related to PEV adoption and whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively PEVs) can fulfill the mission requirements and provides observations related to placement of PEV charging infrastructure. This report provides the results of the data analysis and observations related to the replacement of current vehicles with PEVs. This fulfills part of the Task 3 requirements. Task 3 also includes an assessment of charging infrastructure required to support this replacement. That is the subject of a separate report.

  13. Identification of a detailed function list for public health emergency management using three qualitative methods

    Institute of Scientific and Technical Information of China (English)

    HU Guo-qing; RAO Ke-qin; SUN Zhen-qiu

    2007-01-01

    Background At present, many administrators lack a theoretical guide to build management systemsto cope with public health emergencies. This study developed a detailed function list for public health emergency management to help building the management systems scientifically.Methods The five steps in this study including literature review, semistructured interviews with experts, focus group,Delphi study and focus group were conducted to develop the detailed list of functions.Results An initial list of 25 functions with 188 items was formed through literature review. The list was reduced to 10 functions with 57 items by semistructured interviews with experts and focus group. Next, all these 57 items reached the consensus through one-round Delphi study. Some revisions of the consensus were done by the same focus group.Conclusion The final 10 functions with 57 items could be used as a guide for most countries during their building of a public health emergency management system.

  14. Tubes, tables and traps: great apes solve two functionally equivalent trap tasks but show no evidence of transfer across tasks.

    Science.gov (United States)

    Martin-Ordas, Gema; Call, Josep; Colmenares, Fernando

    2008-07-01

    Previous studies on tool using have shown that presenting subjects with certain modifications in the experimental setup can substantially improve their performance. However, procedural modifications (e.g. trap table task) may not only remove task constraints but also simplify the problem conceptually. The goal of this study was to design a variation of the trap-table that was functionally equivalent to the trap-tube task. In this new task, the subjects had to decide where to insert the tool and in which direction the reward should be pushed. We also administered a trap-tube task that allowed animals to push or rake the reward with the tool to compare the subjects' performance on both tasks. We used a larger sample of subjects than in previous studies and from all the four species of great apes (Gorilla gorilla, Pan troglodytes, Pan paniscus, and Pongo pygmaeus). The results showed that apes performed better in the trap-platform task than in the trap-tube task. Subjects solved the tube task faster than in previous studies and they also preferred to rake in rather than to push the reward out. There was no correlation in the level of performance between both tasks, and no indication of interspecies differences. These data are consistent with the idea that apes may possess some specific causal knowledge of traps but may lack the ability to establish analogical relations between functional equivalent tasks.

  15. Age-related positivity effects and autobiographical memory detail: evidence from a past/future source memory task.

    Science.gov (United States)

    Gallo, David A; Korthauer, Laura E; McDonough, Ian M; Teshale, Salom; Johnson, Elizabeth L

    2011-08-01

    This study investigated whether the age-related positivity effect strengthens specific event details in autobiographical memory. Participants retrieved past events or imagined future events in response to neutral or emotional cue words. Older adults rated each kind of event more positively than younger adults, demonstrating an age-related positivity effect. We next administered a source memory test. Participants were given the same cue words and tried to retrieve the previously generated event and its source (past or future). Accuracy on this source test should depend on the recollection of specific details about the earlier generated events, providing a more objective measure of those details than subjective ratings. We found that source accuracy was greater for positive than negative future events in both age groups, suggesting that positive future events were more detailed. In contrast, valence did not affect source accuracy for past events in either age group, suggesting that positive and negative past events were equally detailed. Although ageing can bias people to focus on positive aspects of experience, this bias does not appear to strengthen the availability of details for positive relative to negative past events.

  16. Functional Fixedness in Creative Thinking Tasks Depends on Stimulus Modality.

    Science.gov (United States)

    Chrysikou, Evangelia G; Motyka, Katharine; Nigro, Cristina; Yang, Song-I; Thompson-Schill, Sharon L

    2016-11-01

    Pictorial examples during creative thinking tasks can lead participants to fixate on these examples and reproduce their elements even when yielding suboptimal creative products. Semantic memory research may illuminate the cognitive processes underlying this effect. Here, we examined whether pictures and words differentially influence access to semantic knowledge for object concepts depending on whether the task is close- or open-ended. Participants viewed either names or pictures of everyday objects, or a combination of the two, and generated common, secondary, or ad hoc uses for them. Stimulus modality effects were assessed quantitatively through reaction times and qualitatively through a novel coding system, which classifies creative output on a continuum from top-down-driven to bottom-up-driven responses. Both analyses revealed differences across tasks. Importantly, for ad hoc uses, participants exposed to pictures generated more top-down-driven responses than those exposed to object names. These findings have implications for accounts of functional fixedness in creative thinking, as well as theories of semantic memory for object concepts.

  17. Musical training, bilingualism, and executive function: a closer look at task switching and dual-task performance.

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-07-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician) were matched on age and socioeconomic status and administered task switching and dual-task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual-task performance, musicians also outperformed non-musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance.

  18. Detailed conceptual design of a high temperature CO/sub 2/ sensor for geothermal brine. Final report, Task II

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, D.M.; Taylor, R.M.; Kugler, G.C.

    1985-10-01

    The Task I pCO/sub 2/ sensor was evaluated in the laboratory and improvements incorporated. Of special note was the redesign of the internal reference electrode which offered greater stability, and improved reliability - a design both smaller and more simple. The ISFET sensor was improved by using a new sensing material which afforded better speed of response. The H/sub 2/S getter was redesigned to overcome seal problems encountered in early Task II tests. The improved probe was thoroughly tested in the laboratory at both moderate and elevated temperatures. This version was also tested at the Magma Electric Company geothermal plant in California. Whereas the laboratory tests were encouraging, the field tests were disappointing, in part due to problems not directly attributable to probe design limitations. In both tests, however, evidence showed that the polymeric seal in the internal ISFET element limited probe life unacceptably in the hot aqueous environment. Electrostatic bonding of silicon to glass for three critical seals is included in the Task II recommended design. All elements of the design were tested successfully in the laboratory.

  19. Musical Training, Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual-Task Performance

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-01-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician)…

  20. Range-separated density-functional theory with random phase approximation: detailed formalism and illustrative applications

    CERN Document Server

    Toulouse, Julien; Angyan, Janos G; Savin, Andreas

    2010-01-01

    Using Green-function many-body theory, we present the details of a formally exact adiabatic-connection fluctuation-dissipation density-functional theory based on range separation, which was sketched in Toulouse, Gerber, Jansen, Savin and Angyan, Phys. Rev. Lett. 102, 096404 (2009). Range-separated density-functional theory approaches combining short-range density functional approximations with long-range random phase approximations (RPA) are then obtained as well-identified approximations on the long-range Green-function self-energy. Range-separated RPA-type schemes with or without long-range Hartree-Fock exchange response kernel are assessed on rare-gas and alkaline-earth dimers, and compared to range-separated second-order perturbation theory and range-separated coupled-cluster theory.

  1. Prediction of detailed enzyme functions and identification of specificity determining residues by random forests.

    Directory of Open Access Journals (Sweden)

    Chioko Nagao

    Full Text Available Determining enzyme functions is essential for a thorough understanding of cellular processes. Although many prediction methods have been developed, it remains a significant challenge to predict enzyme functions at the fourth-digit level of the Enzyme Commission numbers. Functional specificity of enzymes often changes drastically by mutations of a small number of residues and therefore, information about these critical residues can potentially help discriminate detailed functions. However, because these residues must be identified by mutagenesis experiments, the available information is limited, and the lack of experimentally verified specificity determining residues (SDRs has hindered the development of detailed function prediction methods and computational identification of SDRs. Here we present a novel method for predicting enzyme functions by random forests, EFPrf, along with a set of putative SDRs, the random forests derived SDRs (rf-SDRs. EFPrf consists of a set of binary predictors for enzymes in each CATH superfamily and the rf-SDRs are the residue positions corresponding to the most highly contributing attributes obtained from each predictor. EFPrf showed a precision of 0.98 and a recall of 0.89 in a cross-validated benchmark assessment. The rf-SDRs included many residues, whose importance for specificity had been validated experimentally. The analysis of the rf-SDRs revealed both a general tendency that functionally diverged superfamilies tend to include more active site residues in their rf-SDRs than in less diverged superfamilies, and superfamily-specific conservation patterns of each functional residue. EFPrf and the rf-SDRs will be an effective tool for annotating enzyme functions and for understanding how enzyme functions have diverged within each superfamily.

  2. Attentional Focus Effects as a Function of Task Difficulty

    Science.gov (United States)

    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…

  3. Basal paravian functional anatomy illuminated by high-detail body outline

    Science.gov (United States)

    Wang, Xiaoli; Pittman, Michael; Zheng, Xiaoting; Kaye, Thomas G.; Falk, Amanda R.; Hartman, Scott A.; Xu, Xing

    2017-01-01

    Body shape is a fundamental expression of organismal biology, but its quantitative reconstruction in fossil vertebrates is rare. Due to the absence of fossilized soft tissue evidence, the functional consequences of basal paravian body shape and its implications for the origins of avians and flight are not yet fully understood. Here we reconstruct the quantitative body outline of a fossil paravian Anchiornis based on high-definition images of soft tissues revealed by laser-stimulated fluorescence. This body outline confirms patagia-bearing arms, drumstick-shaped legs and a slender tail, features that were probably widespread among paravians. Finely preserved details also reveal similarities in propatagial and footpad form between basal paravians and modern birds, extending their record to the Late Jurassic. The body outline and soft tissue details suggest significant functional decoupling between the legs and tail in at least some basal paravians. The number of seemingly modern propatagial traits hint that feathering was a significant factor in how basal paravians utilized arm, leg and tail function for aerodynamic benefit. PMID:28248287

  4. Detailed exploration of face-related processing in congenital prosopagnosia: 2. Functional neuroimaging findings.

    Science.gov (United States)

    Avidan, Galia; Hasson, Uri; Malach, Rafael; Behrmann, Marlene

    2005-07-01

    Specific regions of the human occipito-temporal cortex are consistently activated in functional imaging studies of face processing. To understand the contribution of these regions to face processing, we examined the pattern of fMRI activation in four congenital prosopagnosic (CP) individuals who are markedly impaired at face processing despite normal vision and intelligence, and with no evidence of brain damage. These individuals evinced a normal pattern of fMRI activation in the fusiform gyrus (FFA) and in other ventral occipito-temporal areas, in response to faces, buildings, and other objects, shown both as line drawings in detection and discrimination tasks and under more naturalistic testing conditions when no task was required. CP individuals also showed normal adaptation levels in a block-design adaptation experiment and, like control subjects, exhibited evidence of global face representation in the FFA. The absence of a BOLD-behavioral correlation (profound behavioral deficit, normal face-related activation in the ventral occipito-temporal cortex) challenges existing accounts of face representation, and suggests that activation in these cortical regions per se is not sufficient to ensure intact face processing.

  5. Providing a more appropriate education for severely handicapped persons: increasing and validating functional classroom tasks.

    Science.gov (United States)

    Reid, D H; Parsons, M B; McCarn, J E; Green, C W; Phillips, J F; Schepis, M M

    1985-01-01

    We evaluated a teacher training and supervision program for increasing the involvement of severely handicapped adolescents and adults in functional educational tasks. The program, consisting of a brief in-service followed by supervisory prompts and feedback, was accompanied by large increases in functional tasks in three classrooms. In addition, generalized increases occurred during nontargeted times in the classroom and the changes during both the targeted and nontargeted times were maintained over a 44-45 week period. In two subsequent experiments, surveys provided social validation for the criteria for functional versus nonfunctional tasks in that: (a) relevant individuals reliably categorized functional tasks as representing typical living, work, social, and leisure situations and (b) experienced clinicians consistently rated tasks previously categorized as functional as being more useful for severely handicapped persons than tasks categorized as nonfunctional. Results are discussed in terms of the relationship of functional classroom tasks in the overall provision of appropriate educational services for severely handicapped students.

  6. Detailed Functional and Proteomic Characterization of Fludarabine Resistance in Mantle Cell Lymphoma Cells.

    Directory of Open Access Journals (Sweden)

    Lucie Lorkova

    Full Text Available Mantle cell lymphoma (MCL is a chronically relapsing aggressive type of B-cell non-Hodgkin lymphoma considered incurable by currently used treatment approaches. Fludarabine is a purine analog clinically still widely used in the therapy of relapsed MCL. Molecular mechanisms of fludarabine resistance have not, however, been studied in the setting of MCL so far. We therefore derived fludarabine-resistant MCL cells (Mino/FR and performed their detailed functional and proteomic characterization compared to the original fludarabine sensitive cells (Mino. We demonstrated that Mino/FR were highly cross-resistant to other antinucleosides (cytarabine, cladribine, gemcitabine and to an inhibitor of Bruton tyrosine kinase (BTK ibrutinib. Sensitivity to other types of anti-lymphoma agents was altered only mildly (methotrexate, doxorubicin, bortezomib or remained unaffacted (cisplatin, bendamustine. The detailed proteomic analysis of Mino/FR compared to Mino cells unveiled over 300 differentially expressed proteins. Mino/FR were characterized by the marked downregulation of deoxycytidine kinase (dCK and BTK (thus explaining the observed crossresistance to antinucleosides and ibrutinib, but also by the upregulation of several enzymes of de novo nucleotide synthesis, as well as the up-regulation of the numerous proteins of DNA repair and replication. The significant upregulation of the key antiapoptotic protein Bcl-2 in Mino/FR cells was associated with the markedly increased sensitivity of the fludarabine-resistant MCL cells to Bcl-2-specific inhibitor ABT199 compared to fludarabine-sensitive cells. Our data thus demonstrate that a detailed molecular analysis of drug-resistant tumor cells can indeed open a way to personalized therapy of resistant malignancies.

  7. Detailed Shape and Evolutionary Behavior of the X-ray Luminosity Function of Active Galactic Nuclei

    CERN Document Server

    Miyaji, T; Salvato, M; Brusa, M; Cappelluti, N; Civano, F; Puccetti, S; Elvis, M; Brunner, H; Fotopoulou, S; Ueda, Y; Griffiths, R E; Koekemoer, A M; Akiyama, M; Comastri, A; Gilli, R; Lanzuisi, G; Merloni, A; Vignali, C

    2015-01-01

    We construct the rest-frame 2--10 keV intrinsic X-ray luminosity function of Active Galactic Nuclei (AGNs) from a combination of X-ray surveys from the all-sky Swift BAT survey to the Chandra Deep Field-South. We use ~3200 AGNs in our analysis, which covers six orders of magnitude in flux. The inclusion of the XMM and Chandra COSMOS data has allowed us to investigate the detailed behavior of the XLF and evolution. In deriving our XLF, we take into account realistic AGN spectrum templates, absorption corrections, and probability density distributions in photometric redshift. We present an analytical expression for the overall behavior of the XLF in terms of the luminosity-dependent density evolution, smoothed two power-law expressions in 11 redshift shells, three-segment power-law expression of the number density evolution in four luminosity classes, and binned XLF. We observe a sudden flattening of the low luminosity end slope of the XLF slope at z>~0.6. Detailed structures of the AGN downsizing have been als...

  8. Evaluating input device usability as a function of task difficulty in a tracking task.

    Science.gov (United States)

    Rupp, Michael A; Oppold, Paul; McConnell, Daniel S

    2015-01-01

    Game controllers are emerging as a preferred choice for the manual control of unmanned vehicles, but an understanding of their usability characteristics has yet to emerge. We compared the usability of an Xbox 360 game controller in a dual task situation using MATB II to the traditional joystick and keyboard interface in two experiments. In the first experiment, performance with the game controller was associated with fewer tracking errors. In a second experiment, we trained users on the devices, and found that even after training the game controller was still associated with fewer tracking errors as well as higher usability and lower workload ratings. These results are consistent with the idea that game controllers are highly usable input devices and do not require high mental workload to operate, thus making them suitable for complex control tasks.

  9. Conformity in the Asch task as a function of age.

    Science.gov (United States)

    Walker, M B; Andrade, M G

    1996-06-01

    The social conformity paradigm of Asch (1956) was replicated to investigate the relationship between age and conformist behavior. One hundred ten Australian school children and adolescents between 3 and 17 years of age participated in the study. Each participant was placed in the position of being a minority of 1 against a wrong but unanimous majority of 3. The results indicate that conformity decreases with age in perceptually unambiguous tasks. Conflicting evidence from earlier studies can be attributed to task ambiguity in those studies.

  10. Conformity in the Asch Task as a Function of Age.

    Science.gov (United States)

    Walker, Michael B.; Andrade, Maria G.

    1996-01-01

    Replicates the Asch conformity experiment (two participants pretend to misjudge a shorter line for a longer one in an attempt to influence a third participant) and applies it to 110 school children ages 3 to 17. Indicates that conformity decreases with age in perceptually ambiguous tasks. (MJP)

  11. Electroencephalography of response inhibition tasks : functional networks and cognitive contributions

    NARCIS (Netherlands)

    Huster, René J; Enriquez-Geppert, Stefanie; Lavallee, Christina F; Falkenstein, Michael; Herrmann, Christoph S

    2013-01-01

    Response inhibition paradigms, as for example stop signal and go/no-go tasks, are often used to study cognitive control processes. Because of the apparent demand to stop a motor reaction, the electrophysiological responses evoked by stop and no-go trials have sometimes likewise been interpreted as i

  12. Molecular Details of Olfactomedin Domains Provide Pathway to Structure-Function Studies.

    Directory of Open Access Journals (Sweden)

    Shannon E Hill

    detailed functional characterization of these biomedically important protein domains.

  13. Neuropsychological assessment of a new computerized cognitive task that developed for training several cognitive functions simultaneously.

    Directory of Open Access Journals (Sweden)

    Satoe eIchihara-Takeda

    2016-04-01

    Full Text Available Recent studies have indicated that computerized cognitive training is effective as therapy for reducing the cognitive decline with aging and the dysfunction associated with neuropsychiatric illness. Although cognitive trainings that targets a specific function and multi-domain cognitive training have both been shown to have significant effects, we need one simple behavioral training paradigm to improve multiple domains of cognitive functions easily and simultaneously. We had developed a new computerized task that seeks to engage the cognitive functions of planning, mental calculation, and divergent thinking based on a working memory task in a single task. The purpose of this study was to assess the cognitive features of our new task by comparing the scores of seven known neuropsychological batteries in healthy elderly subjects. The relationships between performance in our task and the scores obtained by the neuropsychological batteries were examined. The percentage of correct performance on our task was correlated with the scores on the category fluency test, the digit span backward task, and the Trail making test B. Stepwise multiple regression analyses revealed that the scores on the category fluency test and the Trail making test B showed significant positive correlations with the percentage of correct performance on our task. Although the present study did not show high correlations between the percentage of correct performance on our task and working memory functions as a primary target, we did observe mid-level correlations between the percentage of correct performance on our task and functions for divided attention and word fluency. Our new task could not measure subject’s working memory capacity specifically, but could measure the abilities of attention and divergent thinking. Thus, this task might be a useful tool for training multiple cognitive functions simultaneously.

  14. The effect of fMRI task combinations on determining the hemispheric dominance of language functions

    Energy Technology Data Exchange (ETDEWEB)

    Niskanen, Eini [University of Eastern Finland, Department of Applied Physics, Kuopio (Finland); Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); Koenoenen, Mervi [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); Kuopio University Hospital, Department of Clinical Neurophysiology, Kuopio (Finland); Villberg, Ville; Aeikiae, Marja [Kuopio University Hospital, Department of Neurology, Kuopio (Finland); Nissi, Mikko; Ranta-aho, Perttu; Karjalainen, Pasi [University of Eastern Finland, Department of Applied Physics, Kuopio (Finland); Saeisaenen, Laura; Mervaala, Esa [Kuopio University Hospital, Department of Clinical Neurophysiology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Clinical Neurophysiology, Kuopio (Finland); Kaelviaeinen, Reetta [Kuopio University Hospital, Department of Neurology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Neurology, Kuopio (Finland); Vanninen, Ritva [Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); University of Eastern Finland, Institute of Clinical Medicine, Clinical Radiology, Kuopio (Finland)

    2012-04-15

    The purpose of this study is to establish the most suitable combination of functional magnetic resonance imaging (fMRI) language tasks for clinical use in determining language dominance and to define the variability in laterality index (LI) and activation power between different combinations of language tasks. Activation patterns of different fMRI analyses of five language tasks (word generation, responsive naming, letter task, sentence comprehension, and word pair) were defined for 20 healthy volunteers (16 right-handed). LIs and sums of T values were calculated for each task separately and for four combinations of tasks in predefined regions of interest. Variability in terms of activation power and lateralization was defined in each analysis. In addition, the visual assessment of lateralization of language functions based on the individual fMRI activation maps was conducted by an experienced neuroradiologist. A combination analysis of word generation, responsive naming, and sentence comprehension was the most suitable in terms of activation power, robustness to detect essential language areas, and scanning time. In general, combination analyses of the tasks provided higher overall activation levels than single tasks and reduced the number of outlier voxels disturbing the calculation of LI. A combination of auditory and visually presented tasks that activate different aspects of language functions with sufficient activation power may be a useful task battery for determining language dominance in patients. (orig.)

  15. Musical tasks targeting preserved and impaired functions in two dementias.

    Science.gov (United States)

    Halpern, Andrea R; Golden, Hannah L; Magdalinou, Nadia; Witoonpanich, Pirada; Warren, Jason D

    2015-03-01

    Studies of musical abilities in dementia have for the most part been rather general assessments of abilities, for instance, assessing retention of music learned premorbidly. Here, we studied patients with dementias with contrasting cognitive profiles to explore specific aspects of music cognition under challenge. Patients suffered from Alzheimer's disease (AD), in which a primary impairment is in forming new declarative memories, or Lewy body disease (PD/LBD), a type of parkinsonism in which executive impairments are prominent. In the AD patients, we examined musical imagery. Behavioral and neural evidence confirms involvement of perceptual networks in imagery, and these are relatively spared in early stages of the illness. Thus, we expected patients to have relatively intact imagery in a mental pitch comparison task. For the LBD patients, we tested whether executive dysfunction would extend to music. We probed inhibitory skills by asking for a speeded pitch or timbre judgment when the irrelevant dimension was held constant or also changed. Preliminary results show that AD patients score similarly to controls in the imagery tasks, but PD/LBD patients are impaired relative to controls in suppressing some irrelevant musical dimensions, particularly when the required judgment varies from trial to trial. © 2014 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals Inc. on behalf of The New York Academy of Sciences.

  16. Associations between physical function, dual-task performance and cognition in patients with mild Alzheimer's disease

    DEFF Research Database (Denmark)

    Sobol, Nanna Aue; Hoffmann, Kristine; Vogel, Asmus

    2016-01-01

    OBJECTIVE: Alzheimer's disease (AD) causes a gradual decline in cognition, limitations of dual-tasking and physical function leading to total dependence. Hence, information about the interaction between physical function, dual-task performance and cognition may lead to new treatment strategies wi......-task performance was associated with better cognitive performance. CONCLUSION: The evidence of the associations between physical function, dual-task performance and cognition is important when creating new rehabilitation interventions to patients with mild AD.......OBJECTIVE: Alzheimer's disease (AD) causes a gradual decline in cognition, limitations of dual-tasking and physical function leading to total dependence. Hence, information about the interaction between physical function, dual-task performance and cognition may lead to new treatment strategies...... with the purpose of preserving function and quality of life. The objective of this study was to investigate the associations between physical function, dual-task performance and cognition in community-dwelling patients with mild AD. METHODS: Baseline results from 185 participants (50-90 years old) in the single...

  17. A goal activation approach to the study of executive function : An application to antisaccade tasks

    NARCIS (Netherlands)

    Nieuwenhuis, S; Broerse, A; Nielen, MMA; de Jong, R

    2004-01-01

    We argue that a general control process, responsible for the activation and maintenance of task goals, is central to the concept of executive function. Failures of this process can become manifest as goal neglect: disregard of a task requirement even though it has been understood (Duncan, 1995). We

  18. Functional-task exercise versus resistance strength exercise to improve daily function in older women : A randomized, controlled trial

    NARCIS (Netherlands)

    Samson, MM; van Meeteren, NLU; Duursma, SA; Verhaar, HJJ; de Vreede, P.

    2005-01-01

    OBJECTIVES: To determine whether a functional-task exercise program and a resistance exercise program have different effects on the ability of community-living older people to perform daily tasks. DESIGN: A randomized, controlled, single-blind trial. SETTING: Community leisure center in Utrecht, the

  19. Functional cerebral lateralization and dual-task efficiency-testing the function of human brain lateralization using fTCD

    NARCIS (Netherlands)

    Lust, J. M.; Geuze, R. H.; Groothuis, A. G. G.; Bouma, A.; Bouma, J.M.

    2011-01-01

    It has been hypothesized that functional cerebral lateralization enhances cognitive performance. Evidence was found in birds and fish. Our study aimed to test this hypothesis by analyzing the relationship between cerebral lateralization and both single-task performance and dual-task efficiency in

  20. Functional-task exercise versus resistance strength exercise to improve daily function in older women : A randomized, controlled trial

    NARCIS (Netherlands)

    Samson, MM; van Meeteren, NLU; Duursma, SA; Verhaar, HJJ; de Vreede, P.

    OBJECTIVES: To determine whether a functional-task exercise program and a resistance exercise program have different effects on the ability of community-living older people to perform daily tasks. DESIGN: A randomized, controlled, single-blind trial. SETTING: Community leisure center in Utrecht, the

  1. EFFECT OF TASK SPECIFIC MIRROR THERAPY WITH FUNCTIONAL ELECTRICAL STIMULATION ON UPPER LIMB FUNCTION FOR SUBACUTE HEMIPLEGIA

    Directory of Open Access Journals (Sweden)

    Sumana Nagapattinam

    2015-10-01

    Full Text Available Background: The principal target of any stroke rehabilitation is the motor impairments. Many studies have been advocated on the effect of Functional electrical stimulation and Task specific mirror therapy. Hence, the purpose of the study is to find the combined effect of task specific Mirror therapy with Functional Electrical Stimulation on upper limb function for subjects with sub-acute hemiplegia. Methods: An experimental study design, 60 subjects with sub-acute Hemiplegia randomised into 3 groups, functional electrical stimulation group (n=20, task specific mirror therapy group (n=20, and combined group (n=20. Each group received the corresponding regimen of treatment for 30 minutes with rest period for total 12 sessions over 2 weeks along with conventional physiotherapy. The outcome measure such as action research arm test was measured before and after two weeks of intervention. Result: When means of action research arm test were analyzed within the groups, there was a significant difference within all the three groups. When means were compared between three groups there is no statistically significant difference in pre- intervention and post intervention means. Conclusion: It is concluded that a combination therapy of task specific mirror therapy with functional electrical stimulation for two weeks duration, is shown to be effective for recovery of upper limb function in subjects with sub-acute hemiplegia. However, the combination of task specific mirror therapy and functional electrical stimulation is shown to have similar improvements as only task specific mirror therapy and functional electrical stimulation.

  2. Task-related deactivation and functional connectivity of the subgenual cingulate cortex in major depressive disorder

    Directory of Open Access Journals (Sweden)

    Christopher G Davey

    2012-02-01

    Full Text Available Background: Major depressive disorder is associated with functional alterations in activity and resting-state connectivity of the extended medial frontal network. In this study we aimed to examine how task-related medial network activity and connectivity were affected by depression.Methods: Eighteen patients with major depressive disorder, aged 15- to 24-years-old, were matched with 19 healthy control participants. We characterised task-related activations and deactivations while participants engaged with an executive-control task (the multi-source interference task; MSIT. We used a psycho-physiological interactions (PPI approach to examine functional connectivity changes with subgenual ACC. Voxelwise statistical maps for each analysis were compared between the patient and control groups.Results: There were no differences between groups in their behavioral performances on the MSIT task, and nor in patterns of activation and deactivation. Assessment of functional connectivity with the subgenual cingulate showed that depressed patients did not demonstrate the same reduction in functional connectivity with the ventral striatum during task performance, but that they showed greater reduction in functional connectivity with adjacent ventromedial frontal cortex. The magnitude of this latter connectivity change predicted the relative activation of task-relevant executive control regions in depressed patients.Conclusions: The study reinforces the importance of the subgenual cingulate cortex for depression, and demonstrates how dysfunctional connectivity with ventral brain regions might influence executive–attentional processes.

  3. Functional connectivity among spikes in low dimensional space during working memory task in rat.

    Directory of Open Access Journals (Sweden)

    Mei Ouyang

    Full Text Available Working memory (WM is critically important in cognitive tasks. The functional connectivity has been a powerful tool for understanding the mechanism underlying the information processing during WM tasks. The aim of this study is to investigate how to effectively characterize the dynamic variations of the functional connectivity in low dimensional space among the principal components (PCs which were extracted from the instantaneous firing rate series. Spikes were obtained from medial prefrontal cortex (mPFC of rats with implanted microelectrode array and then transformed into continuous series via instantaneous firing rate method. Granger causality method is proposed to study the functional connectivity. Then three scalar metrics were applied to identify the changes of the reduced dimensionality functional network during working memory tasks: functional connectivity (GC, global efficiency (E and casual density (CD. As a comparison, GC, E and CD were also calculated to describe the functional connectivity in the original space. The results showed that these network characteristics dynamically changed during the correct WM tasks. The measure values increased to maximum, and then decreased both in the original and in the reduced dimensionality. Besides, the feature values of the reduced dimensionality were significantly higher during the WM tasks than they were in the original space. These findings suggested that functional connectivity among the spikes varied dynamically during the WM tasks and could be described effectively in the low dimensional space.

  4. Functional connectivity among spikes in low dimensional space during working memory task in rat.

    Science.gov (United States)

    Ouyang, Mei; Li, Shuangyan; Tian, Xin

    2014-01-01

    Working memory (WM) is critically important in cognitive tasks. The functional connectivity has been a powerful tool for understanding the mechanism underlying the information processing during WM tasks. The aim of this study is to investigate how to effectively characterize the dynamic variations of the functional connectivity in low dimensional space among the principal components (PCs) which were extracted from the instantaneous firing rate series. Spikes were obtained from medial prefrontal cortex (mPFC) of rats with implanted microelectrode array and then transformed into continuous series via instantaneous firing rate method. Granger causality method is proposed to study the functional connectivity. Then three scalar metrics were applied to identify the changes of the reduced dimensionality functional network during working memory tasks: functional connectivity (GC), global efficiency (E) and casual density (CD). As a comparison, GC, E and CD were also calculated to describe the functional connectivity in the original space. The results showed that these network characteristics dynamically changed during the correct WM tasks. The measure values increased to maximum, and then decreased both in the original and in the reduced dimensionality. Besides, the feature values of the reduced dimensionality were significantly higher during the WM tasks than they were in the original space. These findings suggested that functional connectivity among the spikes varied dynamically during the WM tasks and could be described effectively in the low dimensional space.

  5. Social task switching: On the automatic social engagement of executive functions.

    Science.gov (United States)

    Dudarev, Veronica; Hassin, Ran R

    2016-01-01

    Humans are quintessentially social, yet much of cognitive psychology has focused on the individual, in individual settings. The literature on joint action is one of the most prominent exceptions. Joint-action research studies the sociality of our mental representations by examining how the tasks of other people around us affect our own task performance. In this paper we go beyond examining whether we represent others and their tasks, by asking whether we also automatically do their tasks with them, even if they require effortful executive functions. To this end we examine one of the core executive functions, shifting, in a new paradigm that allows us to investigate task-switching in a joint-action setup.

  6. Reconfiguration of the Brain Functional Network Associated with Visual Task Demands.

    Science.gov (United States)

    Wen, Xue; Zhang, Delong; Liang, Bishan; Zhang, Ruibin; Wang, Zengjian; Wang, Junjing; Liu, Ming; Huang, Ruiwang

    2015-01-01

    Neuroimaging studies have demonstrated that the topological properties of resting-state brain functional networks are modulated through task performances. However, the reconfiguration of functional networks associated with distinct degrees of task demands is not well understood. In the present study, we acquired fMRI data from 18 healthy adult volunteers during resting-state (RS) and two visual tasks (i.e., visual stimulus watching, VSW; and visual stimulus decision, VSD). Subsequently, we constructed the functional brain networks associated with these three conditions and analyzed the changes in the topological properties (e.g., network efficiency, wiring-cost, modularity, and robustness) among them. Although the small-world attributes were preserved qualitatively across the functional networks of the three conditions, changes in the topological properties were also observed. Compared with the resting-state, the functional networks associated with the visual tasks exhibited significantly increased network efficiency and wiring-cost, but decreased modularity and network robustness. The changes in the task-related topological properties were modulated according to the task complexity (i.e., from RS to VSW and VSD). Moreover, at the regional level, we observed that the increased nodal efficiencies in the visual and working memory regions were positively associated with the increase in task complexity. Together, these results suggest that the increased efficiency of the functional brain network and higher wiring-cost were observed to afford the demands of visual tasks. These observations provide further insights into the mechanisms underlying the reconfiguration of the brain network during task performance.

  7. Functional Task Test: 3. Skeletal Muscle Performance Adaptations to Space Flight

    Science.gov (United States)

    Ryder, Jeffrey W.; Wickwire, P. J.; Buxton, R. E.; Bloomberg, J. J.; Ploutz-Snyder, L.

    2011-01-01

    The functional task test is a multi-disciplinary study investigating how space-flight induced changes to physiological systems impacts functional task performance. Impairment of neuromuscular function would be expected to negatively affect functional performance of crewmembers following exposure to microgravity. This presentation reports the results for muscle performance testing in crewmembers. Functional task performance will be presented in the abstract "Functional Task Test 1: sensory motor adaptations associated with postflight alternations in astronaut functional task performance." METHODS: Muscle performance measures were obtained in crewmembers before and after short-duration space flight aboard the Space Shuttle and long-duration International Space Station (ISS) missions. The battery of muscle performance tests included leg press and bench press measures of isometric force, isotonic power and total work. Knee extension was used for the measurement of central activation and maximal isometric force. Upper and lower body force steadiness control were measured on the bench press and knee extension machine, respectively. Tests were implemented 60 and 30 days before launch, on landing day (Shuttle crew only), and 6, 10 and 30 days after landing. Seven Space Shuttle crew and four ISS crew have completed the muscle performance testing to date. RESULTS: Preliminary results for Space Shuttle crew reveal significant reductions in the leg press performance metrics of maximal isometric force, power and total work on R+0 (pmuscle performance metrics were observed in returning Shuttle crew and these adaptations are likely contributors to impaired functional tasks that are ambulatory in nature (See abstract Functional Task Test: 1). Interestingly, no significant changes in central activation capacity were detected. Therefore, impairments in muscle function in response to short-duration space flight are likely myocellular rather than neuromotor in nature.

  8. NASA's Functional Task Test: Effects of Spaceflight and Six Degree Head-Down Bedrest on Dynamic Postural Stability

    Science.gov (United States)

    Taylor, L. C.; Batson, C. D.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Laurie, S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Peters, B. T.; Phillips, T.; Platts, S. H.; Ploutz-Snyder, L. L.; Reschke, M. F.; Ryder, J. W.; Stenger, M. B.; Wood, S. J.; Bloomberg, J. J.

    2015-01-01

    The goals of the Functional Task Test (FTT) study were to determine the effects of spaceflight on functional tests that are representative of critical exploration mission tasks and to identify the physiological factors that contribute to decrements in performance.

  9. Effects of task-oriented training on mobility function in children with cerebral palsy.

    Science.gov (United States)

    Salem, Yasser; Godwin, Ellen M

    2009-01-01

    Improvement in mobility function has been the primary goal in the rehabilitation of children with cerebral palsy. Few studies have examined the effectiveness of task-oriented strength training for children with cerebral palsy. The purpose of this study was to examine the effects of task-oriented strength training on mobility function in children with cerebral palsy. A single-blind, randomized controlled trial with pre-training and post-training evaluations. Ten children with cerebral palsy (GMFCS levels I-III) were randomly assigned to an experimental group (N = 5) or control group (N = 5). Mobility function was assessed using the Gross Motor Function Measure (GMFM) and the Timed "Up and Go" (TUG) test. Participants in the control group received conventional physical therapy focused on improving walking and balance through facilitation and normalization of movement patterns. Participants in the experiment group received task-oriented strength training focused on strengthening the lower extremities and practicing functional tasks similar to those the child performs during daily activities. After the 5-week training period there were significant improvements in the experimental group for dimension D (p = 0.009), and dimension E (p = 0.009) of the GMFM. The experimental group significantly reduced the time taken to complete the TUG (p = 0.017). This study supports the efficacy of task-oriented strength training for improving mobility function in children with cerebral palsy. The findings demonstrate that the application of a task-oriented strength training program is linked to positive functional outcomes. The results suggest that children with cerebral palsy may benefit from a task-oriented strength training program. Further studies with a larger randomized sample and longer post-intervention follow-up are necessary to document the long-term effects of participation in task-oriented strength training programs in the cerebral palsy population.

  10. Executive functioning in daily life in Parkinson's disease: initiative, planning and multi-task performance.

    Directory of Open Access Journals (Sweden)

    Janneke Koerts

    Full Text Available Impairments in executive functioning are frequently observed in Parkinson's disease (PD. However, executive functioning needed in daily life is difficult to measure. Considering this difficulty the Cognitive Effort Test (CET was recently developed. In this multi-task test the goals are specified but participants are free in their approach. This study applies the CET in PD patients and investigates whether initiative, planning and multi-tasking are associated with aspects of executive functions and psychomotor speed. Thirty-six PD patients with a mild to moderate disease severity and thirty-four healthy participants were included in this study. PD patients planned and demonstrated more sequential task execution, which was associated with a decreased psychomotor speed. Furthermore, patients with a moderate PD planned to execute fewer tasks at the same time than patients with a mild PD. No differences were found between these groups for multi-tasking. In conclusion, PD patients planned and executed the tasks of the CET sequentially rather than in parallel presumably reflecting a compensation strategy for a decreased psychomotor speed. Furthermore, patients with moderate PD appeared to take their impairments into consideration when planning how to engage the tasks of the test. This compensation could not be detected in patients with mild PD.

  11. Task-evoked brain functional magnetic susceptibility mapping by independent component analysis (χICA).

    Science.gov (United States)

    Chen, Zikuan; Calhoun, Vince D

    2016-03-01

    Conventionally, independent component analysis (ICA) is performed on an fMRI magnitude dataset to analyze brain functional mapping (AICA). By solving the inverse problem of fMRI, we can reconstruct the brain magnetic susceptibility (χ) functional states. Upon the reconstructed χ dataspace, we propose an ICA-based brain functional χ mapping method (χICA) to extract task-evoked brain functional map. A complex division algorithm is applied to a timeseries of fMRI phase images to extract temporal phase changes (relative to an OFF-state snapshot). A computed inverse MRI (CIMRI) model is used to reconstruct a 4D brain χ response dataset. χICA is implemented by applying a spatial InfoMax ICA algorithm to the reconstructed 4D χ dataspace. With finger-tapping experiments on a 7T system, the χICA-extracted χ-depicted functional map is similar to the SPM-inferred functional χ map by a spatial correlation of 0.67 ± 0.05. In comparison, the AICA-extracted magnitude-depicted map is correlated with the SPM magnitude map by 0.81 ± 0.05. The understanding of the inferiority of χICA to AICA for task-evoked functional map is an ongoing research topic. For task-evoked brain functional mapping, we compare the data-driven ICA method with the task-correlated SPM method. In particular, we compare χICA with AICA for extracting task-correlated timecourses and functional maps. χICA can extract a χ-depicted task-evoked brain functional map from a reconstructed χ dataspace without the knowledge about brain hemodynamic responses. The χICA-extracted brain functional χ map reveals a bidirectional BOLD response pattern that is unavailable (or different) from AICA. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Overcoming duality: the fused bousfieldian function for modeling word production in verbal fluency tasks.

    Science.gov (United States)

    Ehlen, Felicitas; Fromm, Ortwin; Vonberg, Isabelle; Klostermann, Fabian

    2016-10-01

    Word production is generally assumed to occur as a function of a broadly interconnected language system. In terms of verbal fluency tasks, word production dynamics can be assessed by analyzing respective time courses via curve fitting. Here, a new generalized fitting function is presented by merging the two dichotomous classical Bousfieldian functions into one overarching power function with an adjustable shape parameter. When applied to empirical data from verbal fluency tasks, the error of approximation was significantly reduced while also fulfilling the Bayesian information criterion, suggesting a superior overall application value. Moreover, the approach identified a previously unknown logarithmic time course, providing further evidence of an underlying lexical network structure. In view of theories on lexical access, the corresponding modeling differentiates task-immanent lexical suppression from automatic lexical coactivation. In conclusion, our approach indicates that process dynamics result from an increasing cognitive effort to suppress automatic network functions.

  13. Do Cost Functions for Tracking Error Generalize across Tasks with Different Noise Levels?

    Science.gov (United States)

    Sensinger, Jonathon; Aleman-Zapata, Adrian; Englehart, Kevin

    2015-01-01

    Control of human-machine interfaces are well modeled by computational control models, which take into account the behavioral decisions people make in estimating task dynamics and state for a given control law. This control law is optimized according to a cost function, which for the sake of mathematical tractability is typically represented as a series of quadratic terms. Recent studies have found that people actually use cost functions for reaching tasks that are slightly different than a quadratic function, but it is unclear which of several cost functions best explain human behavior and if these cost functions generalize across tasks of similar nature but different scale. In this study, we used an inverse-decision-theory technique to reconstruct the cost function from empirical data collected on 24 able-bodied subjects controlling a myoelectric interface. Compared with previous studies, this experimental paradigm involved a different control source (myoelectric control, which has inherently large multiplicative noise), a different control interface (control signal was mapped to cursor velocity), and a different task (the tracking position dynamically moved on the screen throughout each trial). Several cost functions, including a linear-quadratic; an inverted Gaussian, and a power function, accurately described the behavior of subjects throughout this experiment better than a quadratic cost function or other explored candidate cost functions (p<0.05). Importantly, despite the differences in the experimental paradigm and a substantially larger scale of error, we found only one candidate cost function whose parameter was consistent with the previous studies: a power function (cost ∝ errorα) with a parameter value of α = 1.69 (1.53–1.78 interquartile range). This result suggests that a power-function is a representative function of user’s error cost over a range of noise amplitudes for pointing and tracking tasks. PMID:26313560

  14. Do Cost Functions for Tracking Error Generalize across Tasks with Different Noise Levels?

    Directory of Open Access Journals (Sweden)

    Jonathon Sensinger

    Full Text Available Control of human-machine interfaces are well modeled by computational control models, which take into account the behavioral decisions people make in estimating task dynamics and state for a given control law. This control law is optimized according to a cost function, which for the sake of mathematical tractability is typically represented as a series of quadratic terms. Recent studies have found that people actually use cost functions for reaching tasks that are slightly different than a quadratic function, but it is unclear which of several cost functions best explain human behavior and if these cost functions generalize across tasks of similar nature but different scale. In this study, we used an inverse-decision-theory technique to reconstruct the cost function from empirical data collected on 24 able-bodied subjects controlling a myoelectric interface. Compared with previous studies, this experimental paradigm involved a different control source (myoelectric control, which has inherently large multiplicative noise, a different control interface (control signal was mapped to cursor velocity, and a different task (the tracking position dynamically moved on the screen throughout each trial. Several cost functions, including a linear-quadratic; an inverted Gaussian, and a power function, accurately described the behavior of subjects throughout this experiment better than a quadratic cost function or other explored candidate cost functions (p<0.05. Importantly, despite the differences in the experimental paradigm and a substantially larger scale of error, we found only one candidate cost function whose parameter was consistent with the previous studies: a power function (cost ∝ errorα with a parameter value of α = 1.69 (1.53-1.78 interquartile range. This result suggests that a power-function is a representative function of user's error cost over a range of noise amplitudes for pointing and tracking tasks.

  15. Do Cost Functions for Tracking Error Generalize across Tasks with Different Noise Levels?

    Science.gov (United States)

    Sensinger, Jonathon; Aleman-Zapata, Adrian; Englehart, Kevin

    2015-01-01

    Control of human-machine interfaces are well modeled by computational control models, which take into account the behavioral decisions people make in estimating task dynamics and state for a given control law. This control law is optimized according to a cost function, which for the sake of mathematical tractability is typically represented as a series of quadratic terms. Recent studies have found that people actually use cost functions for reaching tasks that are slightly different than a quadratic function, but it is unclear which of several cost functions best explain human behavior and if these cost functions generalize across tasks of similar nature but different scale. In this study, we used an inverse-decision-theory technique to reconstruct the cost function from empirical data collected on 24 able-bodied subjects controlling a myoelectric interface. Compared with previous studies, this experimental paradigm involved a different control source (myoelectric control, which has inherently large multiplicative noise), a different control interface (control signal was mapped to cursor velocity), and a different task (the tracking position dynamically moved on the screen throughout each trial). Several cost functions, including a linear-quadratic; an inverted Gaussian, and a power function, accurately described the behavior of subjects throughout this experiment better than a quadratic cost function or other explored candidate cost functions (p<0.05). Importantly, despite the differences in the experimental paradigm and a substantially larger scale of error, we found only one candidate cost function whose parameter was consistent with the previous studies: a power function (cost ∝ errorα) with a parameter value of α = 1.69 (1.53-1.78 interquartile range). This result suggests that a power-function is a representative function of user's error cost over a range of noise amplitudes for pointing and tracking tasks.

  16. Roles, tasks and educational functions of postgraduate programme directors: a qualitative study.

    Science.gov (United States)

    Frydén, Hanna; Ponzer, Sari; Heikkilä, Kristiina; Kihlström, Lars; Nordquist, Jonas

    2015-10-01

    A programme director is often required to organise postgraduate medical education. This leadership role can include educational as well as managerial duties. Only a few published studies have explored programme directors' own perceptions of their role. There is a need to explore the use of theoretical frameworks to improve the understanding of educational roles. To explore programme directors' own perceptions of their role in terms of tasks and functions, and to relate these roles to the theoretical framework developed by Bolman and Deal. Semi-structured interviews were conducted with 17 programme directors between February and August 2013. The data were subjected to content analysis using a deductive approach. The various roles and tasks included by participants in their perceptions of their work could be categorised within the framework of functions described by Bolman and Deal. These included: structuring the education (structural function); supporting individuals and handling relations (human resource function); negotiating between different interests (political function); and influencing the culture at the departmental level (symbolic function). The functions most often emphasised by participants were the structural and human resource functions. Some tasks involved several functions which varied over time. Programme directors' own perceptions of their roles, tasks and functions varied widely. The theoretical framework of Bolman and Deal might be helpful when explaining and developing these roles. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  17. Detailed first-principles studies on surface energy and work function of hexagonal metals

    Science.gov (United States)

    Ji, De-Peng; Zhu, Quanxi; Wang, Shao-Qing

    2016-09-01

    The surface energies and work functions for ten kinds of Miller-indices surfaces of hexagonal metals, Be, Mg, Tc, Re, Ru, and Os are calculated by means of the density functional theory (DFT) method. The results show that the metals belonging to the same group have a very similar rule in work functions and surface energies. The work functions of (0001), (01 1 - 1)" separators=",, and (10 1 - 0)" separators=", surfaces are generally larger than the work functions of (11 2 - 1)" separators=",, (11 2 - 2)" separators=",, (11 2 - 3)" separators=",, and (31 4 - 0)" separators=", surfaces. In contrast to work functions, there is more regularity in the crystallographic orientation dependence of surface energies. However, for the metals belonging to different groups, there are always some differences in the exact order of orientation dependence. It is also shown that the work functions and surface energies of the main group metals decrease as they go from top to the bottom in the same group of periodic table, while for the transition metals, they do not always obey this rule.

  18. Plasmon spectrum of degenerated electron gas. T=0 Green function method. Detailed pedagogical derivation

    OpenAIRE

    Mishonov, Todor M.; Atanasova, Liliya A.; Ivanov, Peter A; Valchev, Tihomir I.; Arnaudov, Dimo L.

    2003-01-01

    Plasmon spectrum and polarization operator of 1, 2, and 3 dimensional electron gas are calculated by T=0 Green function technique. It is shown that this field theory method gives probably the simplest pedagogical derivation of the statistical problem for the response function. The explanation is complimentary to the standard courses on condensed matter and plasma physics of the level of IX volume of Landau-Lifshitz encyclopedia on theoretical physics.

  19. Task-related changes in functional properties of the human brain network underlying attentional control.

    Directory of Open Access Journals (Sweden)

    Tetsuo Kida

    Full Text Available Previous studies have demonstrated task-related changes in brain activation and inter-regional connectivity but the temporal dynamics of functional properties of the brain during task execution is still unclear. In the present study, we investigated task-related changes in functional properties of the human brain network by applying graph-theoretical analysis to magnetoencephalography (MEG. Subjects performed a cue-target attention task in which a visual cue informed them of the direction of focus for incoming auditory or tactile target stimuli, but not the sensory modality. We analyzed the MEG signal in the cue-target interval to examine network properties during attentional control. Cluster-based non-parametric permutation tests with the Monte-Carlo method showed that in the cue-target interval, beta activity was desynchronized in the sensori-motor region including premotor and posterior parietal regions in the hemisphere contralateral to the attended side. Graph-theoretical analysis revealed that, in beta frequency, global hubs were found around the sensori-motor and prefrontal regions, and functional segregation over the entire network was decreased during attentional control compared to the baseline. Thus, network measures revealed task-related temporal changes in functional properties of the human brain network, leading to the understanding of how the brain dynamically responds to task execution as a network.

  20. Task-related changes in functional properties of the human brain network underlying attentional control.

    Science.gov (United States)

    Kida, Tetsuo; Kakigi, Ryusuke

    2013-01-01

    Previous studies have demonstrated task-related changes in brain activation and inter-regional connectivity but the temporal dynamics of functional properties of the brain during task execution is still unclear. In the present study, we investigated task-related changes in functional properties of the human brain network by applying graph-theoretical analysis to magnetoencephalography (MEG). Subjects performed a cue-target attention task in which a visual cue informed them of the direction of focus for incoming auditory or tactile target stimuli, but not the sensory modality. We analyzed the MEG signal in the cue-target interval to examine network properties during attentional control. Cluster-based non-parametric permutation tests with the Monte-Carlo method showed that in the cue-target interval, beta activity was desynchronized in the sensori-motor region including premotor and posterior parietal regions in the hemisphere contralateral to the attended side. Graph-theoretical analysis revealed that, in beta frequency, global hubs were found around the sensori-motor and prefrontal regions, and functional segregation over the entire network was decreased during attentional control compared to the baseline. Thus, network measures revealed task-related temporal changes in functional properties of the human brain network, leading to the understanding of how the brain dynamically responds to task execution as a network.

  1. Sparse representation of higher-order functional interaction patterns in task-based FMRI data.

    Science.gov (United States)

    Zhang, Shu; Li, Xiang; Lv, Jinglei; Jiang, Xi; Zhu, Dajiang; Chen, Hanbo; Zhang, Tuo; Guo, Lei; Liu, Tianming

    2013-01-01

    Traditional task-based fMRI activation detection methods, e.g., the widely used general linear model (GLM), assume that the brain's hemodynamic responses follow the block-based or event-related stimulus paradigm. Typically, these activation detections are performed voxel-wise independently, and then are usually followed by statistical corrections. Despite remarkable successes and wide adoption of these methods, it remains largely unknown how functional brain regions interact with each other within specific networks during task performance blocks and in the baseline. In this paper, we present a novel algorithmic pipeline to statistically infer and sparsely represent higher-order functional interaction patterns within the working memory network during task performance and in the baseline. Specifically, a collection of higher-order interactions are inferred via the greedy equivalence search (GES) algorithm for both task and baseline blocks. In the next stage, an effective online dictionary learning algorithm is utilized for sparse representation of the inferred higher-order interaction patterns. Application of this framework on a working memory task-based fMRI data reveals interesting and meaningful distributions of the learned sparse dictionary atoms in task and baseline blocks. In comparison with traditional voxel-wise activation detection and recent pair-wise functional connectivity analysis, our framework offers a new methodology for representation and exploration of higher-order functional activities in the brain.

  2. Behavioural implications of alarm mistrust as a function of task workload.

    Science.gov (United States)

    Bliss, J P; Dunn, M C

    2000-09-01

    The research was conducted to investigate the effect of increasing primary task and alarm workload on alarm mistrust as reflected by alarm and primary task performances. A total of 126 undergraduate students performed a complex psychomotor task battery three times, with the number of concurrent tasks increasing each time. During their performance, the students were required to react to an alarm system (including visual and auditory components) of questionable reliability. Depending on the group to which participants were assigned, the alarm presentation rate constituted a low-, medium- or high-workload condition. Alarm response data (times, frequencies, accuracies) and primary task data (tracking error) were analyzed to assess performance differences as a function of primary and secondary task workload levels. Results generally supported the hypotheses: increasing primary task and alarm task workload degraded alarm response performance. Also, response frequencies supported earlier research suggesting that participants 'probability match' their response rates to alarm system reliability. The results are discussed with regard to the cry-wolf effect, attention theory and alarm system design.

  3. Novel response function resolves by image deconvolution more details of surface nanomorphology

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2010-01-01

    A novel method of image processing is presented which relies on deconvolution of data using the response function of the apparatus. It is revealed that all the surface structures observed by digital imaging are generated by a convolution of the response function of the apparatus with the surfaces......’ nanomorphology, which provided images of convoluted physical structures rather than images of real physical structures. In order to restore the genuine physical information on surface structures, a deconvolution using a novel response function of the feedback circuitry is required. At the highest resolution......, that is, atomic resolution, the effect of deconvolution is at its maximum, whereas images at lower resolution are sharpened by eliminating smoothing effects and shadow effects. The method is applied to measurements of imaging by in situ scanning tunnelling microscopy (in situ STM) at atomic resolution...

  4. Detection versus location judgments in a hidden pattern task: functional MRI and behavioral correlates.

    Science.gov (United States)

    Bolster, R Bruce; D'Arcy, Ryan C N; Song, Xiaowei; Runke, Dwayne S; Ryner, Lawrence

    2011-08-01

    We used functional magnetic resonance imaging (fMRI) to assess cortical involvement in a hidden pattern task. The experimental and control conditions involved judgment of the presence/absence versus the position of a complex pattern. Activation specific to hidden pattern identification was concentrated on frontal, dorsal parietal, and mesolimbic cortex. This was consistent not only across individual subjects, but with hidden figures tasks used in previous fMRI investigations. Results suggest that pattern identification relies on a relatively stable neural network controlling selective attention. In combination with fMRI, hidden pattern tasks may be useful in neuropsychological assessment of visual search and object identification.

  5. Decreased Functional Brain Activation in Friedreich Ataxia Using the Simon Effect Task

    Science.gov (United States)

    Georgiou-Karistianis, N.; Akhlaghi, H.; Corben, L. A.; Delatycki, M. B.; Storey, E.; Bradshaw, J. L.; Egan, G. F.

    2012-01-01

    The present study applied the Simon effect task to examine the pattern of functional brain reorganization in individuals with Friedreich ataxia (FRDA), using functional magnetic resonance imaging (fMRI). Thirteen individuals with FRDA and 14 age and sex matched controls participated, and were required to respond to either congruent or incongruent…

  6. Blending Functional Communication Training and Choice Making to Improve Task Engagement and Decrease Problem Behaviour

    Science.gov (United States)

    Peterson, Stephanie M. Peck; Caniglia, Cyndi; Royster, Amy Jo; Macfarlane, Emily; Plowman, Kristen; Baird, Sally Jo; Wu, Nadia

    2005-01-01

    This study evaluated the effects of choice making within functional communication training (FCT) to increase the task engagement of two participants with inappropriate behaviour. Pretreatment functional analyses indicated that both participants' inappropriate behaviour was maintained by escape. For one of the participants, inappropriate behaviour…

  7. Classroom-Based Functional Analysis and Intervention for Disruptive and Off-Task Behaviors

    Science.gov (United States)

    Shumate, Emily D.; Wills, Howard P.

    2010-01-01

    Although there is a growing body of literature on the use of functional analysis in schools, there is a need for more demonstrations of this technology being used during the course of typical instruction. In this study, we conducted functional analyses of disruptive and off-task behavior in a reading classroom setting for 3 participants of typical…

  8. Practicing a functional task improves steadiness with hand muscles in older adults.

    Science.gov (United States)

    Marmon, Adam R; Gould, Jeffrey R; Enoka, Roger M

    2011-08-01

    Improvements in steadiness with practice have been associated with enhanced performance on a functional task in old adults. The aims of the study were to examine the specificity of the association between steadiness and a functional task and to assess the influence of practicing a functional task on force steadiness of hand muscles. Twenty-three older adults (≥70 yr) participated in the study and were assigned to either a practice group (n = 15) or a control group (n = 8). Subjects completed two testing sessions that were 2 wk apart. The practice group completed six additional sessions to practice a functional task (Grooved Pegboard). Tests included maximal voluntary contractions (MVC), force steadiness (precision pinch and index finger abduction) at three target forces (5%, 15%, and 25% MVC), and the Grooved Pegboard test. The associations between strength, steadiness, and the time needed to complete the Grooved Pegboard test were examined. In addition, MVC force, steadiness, and pegboard time were compared between the two testing sessions. The time needed to complete the Grooved Pegboard test was associated with index finger abduction steadiness for two of the three target forces (15% and 25% MVC) but was not associated with pinch steadiness. Practice significantly reduced the time needed to complete the Grooved Pegboard test and improved steadiness in both tasks. Force steadiness provides an appropriate index of hand function, especially when measured at low forces.

  9. Understanding human factors in rail engineering: re-analysis of detailed, qualitative data on functions and risks.

    Science.gov (United States)

    Ryan, Brendan; Wilsona, John R; Schock, Alex

    2012-01-01

    The paper reports on the review and re-analysis of information that has been collected in earlier field studies on the functions and associated risks in rail engineering and maintenance. Two methods of Cognitive Work Analysis have been adapted and used to identify and represent important components of the rail engineering system and the situations in which activities occur. Additional classification exercises have been used to determine issues of strategic importance to the organisation, related to the functions and human factors risks in performing these functions. The effectiveness of the methods in this industrial context has been evaluated. Conclusions are drawn on how this type of approach can be used to produce relevant findings on the following: What the organisation knows about roles, functions and descriptions of tasks that are relevant for engineering and maintenance work; (2) the HF risks for today's (and unless things change), tomorrow's railway; (3) how this knowledge can help in determining organisational priorities for future work.

  10. Comparison of Functional Connectivity Estimated from Concatenated Task-State Data from Block-Design Paradigm with That of Continuous Task

    Science.gov (United States)

    Zhu, Yang; Cheng, Lin; He, Naying; Yang, Yang; Ling, Huawei; Tong, Shanbao

    2017-01-01

    Functional connectivity (FC) analysis with data collected as continuous tasks and activation analysis using data from block-design paradigms are two main methods to investigate the task-induced brain activation. If the concatenated data of task blocks extracted from the block-design paradigm could provide equivalent FC information to that derived from continuous task data, it would shorten the data collection time and simplify experimental procedures, and the already collected data of block-design paradigms could be reanalyzed from the perspective of FC. Despite being used in many studies, such a hypothesis of equivalence has not yet been tested from multiple perspectives. In this study, we collected fMRI blood-oxygen-level-dependent signals from 24 healthy subjects during a continuous task session as well as in block-design task sessions. We compared concatenated task blocks and continuous task data in terms of region of interest- (ROI-) based FC, seed-based FC, and brain network topology during a short motor task. According to our results, the concatenated data was not significantly different from the continuous data in multiple aspects, indicating the potential of using concatenated data to estimate task-state FC in short motor tasks. However, even under appropriate experimental conditions, the interpretation of FC results based on concatenated data should be cautious and take the influence due to inherent information loss during concatenation into account. PMID:28191030

  11. Comparison of two fMRI tasks for the evaluation of the expressive language function

    Energy Technology Data Exchange (ETDEWEB)

    Sanjuan, Ana; Avila, Cesar [Universitat Jaume I, Departamento de Psicologia Basica, Clinica y Psicobiologia, Castellon de la Plana (Spain); Hospital La Fe, Unidad de Epilepsia, Servicio de Neurologia, Valencia (Spain); Bustamante, Juan-Carlos; Forn, Cristina; Ventura-Campos, Noelia; Barros-Loscertales, Alfonso [Universitat Jaume I, Departamento de Psicologia Basica, Clinica y Psicobiologia, Castellon de la Plana (Spain); Martinez, Juan-Carlos [Hospital La Fe, Eresa, Valencia (Spain); Hospital La Fe, Unidad de Epilepsia, Servicio de Neurologia, Valencia (Spain); Villanueva, Vicente [Hospital La Fe, Unidad de Epilepsia, Servicio de Neurologia, Valencia (Spain)

    2010-05-15

    Presurgical evaluation of language is important in patients who are candidates for neurosurgery since language decline is a frequent complication after an operation. Different functional magnetic resonance imaging (fMRI) tasks, such as the verb generation task (VGT) and the verbal fluency task (VFT) have been employed. Our objective was to compare how effective these tasks are at evaluating language functioning in controls (study 1) and patients (study 2). Eighteen controls and 58 patient candidates for neurosurgery (16 patients with temporal lobe epilepsy and 42 patients with brain lesions: 11 astrocytomas, six cavernomas, 14 gliomas, four AVM and seven meningiomas) were recruited in order to compare the activation patterns of language areas as determined by the VGT and VFT. In both samples, the VGT produced a more specific activation of left Broca's area. In contrast, the VFT yielded a wider and more intense activation of the left Broca's area in controls, as well as other activations in the dorsolateral prefrontal cortex and the striatum. Additionally, both studies showed good agreement on language dominance derived from the tasks, although there was some variability in laterality index scores. Both language tasks are useful in evaluation of expressive language. The VGT is a more specific task, while the VFT is more unspecific but activates language-related areas that are not found with the VGT owing to its phonological component. Therefore, each task contributes to the lateralisation and localisation of expressive language areas with complementary information. The advisability of combining tasks to improve fMRI presurgical evaluation is confirmed. (orig.)

  12. Task Requirements, Task Representation, and Self-Reported Citation Functions: An Exploratory Study of a Successful L2 Student's Writing

    Science.gov (United States)

    Petric, Bojana; Harwood, Nigel

    2013-01-01

    This mixed-method study investigates the citation behaviour of a successful L2 postgraduate management student, Sofie, in two pieces of writing, written in response to two assignment tasks in two management modules. The tasks belonged to the same assignment type, but differed in the level of direction provided: one was a directed task, accompanied…

  13. The Functional Task Test (FTT): An Interdisciplinary Testing Protocol to Investigate the Factors Underlying Changes in Astronaut Functional Performance

    Science.gov (United States)

    Bloomberg, J. J.; Lawrence, E. L.; Arzeno, N. M.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts. S. H.; hide

    2011-01-01

    Exposure to space flight causes adaptations in multiple physiological systems including changes in sensorimotor, cardiovascular, and neuromuscular systems. These changes may affect a crewmember s ability to perform critical mission tasks immediately after landing on a planetary surface. The overall goal of this project is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. To achieve this goal we developed an interdisciplinary testing protocol (Functional Task Test, FTT) that evaluates both astronaut functional performance and related physiological changes. Functional tests include ladder climbing, hatch opening, jump down, manual manipulation of objects and tool use, seat egress and obstacle avoidance, recovery from a fall and object translation tasks. Physiological measures include assessments of postural and gait control, dynamic visual acuity, fine motor control, plasma volume, orthostatic intolerance, upper- and lower-body muscle strength, power, endurance, control, and neuromuscular drive. Crewmembers perform this integrated test protocol before and after short (Shuttle) and long-duration (ISS) space flight. Data are collected on two sessions before flight, on landing day (Shuttle only) and 1, 6 and 30 days after landing. Preliminary results from both Shuttle and ISS crewmembers indicate decrement in performance of the functional tasks after both short and long-duration space flight. On-going data collection continues to improve the statistical power required to map changes in functional task performance to alterations in physiological systems. The information obtained from this study will be used to design and implement countermeasures that specifically target the physiological systems most responsible for the altered functional performance associated with space flight.

  14. A detailed study of nucleon structure function in nuclei in the valence quark region

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, N. [INFN-Laboratori, Nazionali di Frascati (Italy)

    1994-04-01

    The so called {open_quotes}EMC effect{close_quotes} discovered during the 1980`s, has caused a big controversy in the community of nuclear and high energy physicists; during the last ten years, five experiments have been performed in different laboratories and several hundreds of papers about the possible interpretation of the modification of the nucleon structure function inside nuclei have been published. However, from the experimental point of view, the main goal of four experiments (EMC, BCDMS, NMC, FNAL) has been to emphasize the region of low x{sub b}, where shadowing effects appear. In the region of valence quarks and nuclear effects (x{sub b} > 0.1 - 0.2) the most reliable data presently available are from the SLAC E139 experiment performed in 1983 with only 80 hours of beam time. New precise data in the valence quark region are necessary to measure separate structure functions F{sub 2}(x{sub b}, Q{sup 2}) and R{sup lt}(x{sub b},Q{sup 2}) = {sigma}{sub l}/{sigma}{sub t}, and to investigate the real A-dependence of the ratio between bound and free-nucleon structure functions which is not completely defined by the SLAC data. Moreover, from the nuclear physics point of view, a measurement on some unexplored nuclei, like {sup 3}He and {sup 48}Ca, would be of great interest. The intermediate scaling region (0.1 < x{sub b} < 0.7) would be accessible at CEBAF if the machine energy will reach 6-8 GeV, as suggested by all the tests performed on the RF cavities. This physics program has been already presented in two letter of intents.

  15. Brazilian adaptation of the Hotel Task: a tool for the ecological assessment of executive functions

    Directory of Open Access Journals (Sweden)

    Caroline de Oliveira Cardoso

    Full Text Available Over recent years, neuropsychological research has been increasingly concerned with the need to develop more ecologically valid instruments for the assessment of executive functions. The Hotel Task is one of the most widely used ecological measures of executive functioning, and provides an assessment of planning, organization, self-monitoring and cognitive flexibility. OBJECTIVE: The goal of this study was to adapt the Hotel Task for use in the Brazilian population. METHODS: The sample comprised 27 participants (three translators, six expert judges, seven healthy adults, ten patients with traumatic brain injuries and one hotel manager. The adaptation process consisted of five steps, which were repeated until a satisfactory version of the task was produced. The steps were as follows: (1 Translation; (2 Development of new stimuli and brainstorming among the authors; (3 Analysis by expert judges; (4 Pilot studies; (5 Assessment by an expert in business administration and hotel management. RESULTS: The adapted version proved adequate and valid for the assessment of executive functions. However, further research must be conducted to obtain evidence of the reliability, as well as the construct and criterion validity, sensitivity and specificity, of the Hotel Task. CONCLUSION: Many neurological and/or psychiatric populations may benefit from the adapted task, since it may make significant contributions to the assessment of dysexecutive syndromes and their impact on patient functioning.

  16. Mastering developmental transitions in immigrant adolescents: the longitudinal interplay of family functioning, developmental and acculturative tasks.

    Science.gov (United States)

    Reitz, Anne K; Motti-Stefanidi, Frosso; Asendorpf, Jens B

    2014-03-01

    Immigrant youth differ in their adaptation, which is judged on the basis of how well they deal with developmental and acculturative tasks. While immigrant adolescents are faced with the realities of 2 different cultures, they also have to master age-salient tasks, such as self-efficacy and identity development. To get a better insight into the interplay of developmental and acculturative tasks and their relationship with family functioning, we used 3-wave longitudinal data over a 2-year period from 13-year-old immigrant students (N = 609) in Athens, Greece. Cross-lagged models revealed that family functioning and acculturation were resources for the mastery of developmental tasks. Involvement in the host culture prospectively predicted self-efficacy beliefs, and involvement in the ethnic culture prospectively predicted ethnic identity. These effects increased over time. Family functioning prospectively predicted self-efficacy and ethnic identity. These effects decreased over time. The findings suggest that a well-functioning family, for early adolescents, and being involved in the host culture and in ethnic cultures, for middle adolescents, are particularly important resources to master the tasks of their developmental period. Our findings underscore the importance of developmentally sensitive approaches and the need to account for acculturative challenges in order to understand individual differences in immigrant youth adaptation.

  17. Comparing the Predictive Value of Task Performance and Task-Specific Sensitivity During Physical Function Testing Among People With Knee Osteoarthritis.

    Science.gov (United States)

    Wideman, Timothy H; Edwards, Robert R; Finan, Patrick H; Haythornthwaite, Jennifer A; Smith, Michael T

    2016-05-01

    Study Design Cross-sectional cohort. Background Knee osteoarthritis (OA) is a leading cause of pain and mobility restriction. Past research has advocated the use of brief, functional tasks to evaluate these restrictions, such as the six-minute-walk test and the timed up-and-go test. Typically, only task performance (ie, walking distance, completion time) is used to inform clinical practice. Recent research, however, suggests that individual variance in how people feel while completing these tasks (ie, task sensitivity) might also have important clinical value. Objective To compare the predictive value of task performance and task-specific sensitivity in determining OA-related physical function (measured by the Western Ontario and McMaster Universities Osteoarthritis Index) and pain-related interference (measured by the Multidimensional Pain Inventory). Methods One hundred eight participants with chronic knee OA completed the six-minute-walk test and the timed up-and-go test, and reported levels of discomfort and affective response (mood) associated with each test. Results In separate regression models, both task performance and task-specific sensitivity predicted OA-related physical function and pain-related interference. A final regression model including all significant predictors showed that task-specific sensitivity (specifically, post-six-minute-walk discomfort) emerged as a unique predictor of both outcomes. Conclusion These findings highlight the value of a novel clinical assessment strategy for patients with knee OA. While clinicians commonly focus on how patients perform on standardized functional tasks, these results highlight the value of also considering levels of posttask sensitivity. Measures of task-specific sensitivity relate to Maitland's concept of pain irritability, which may be a useful framework for future research on sensitizing factors and pain-related disability. J Orthop Sports Phys Ther 2016;46(5):346-356. Epub 21 Mar 2016. doi:10

  18. Investigating executive functions in children with severe speech and movement disorders using structured tasks

    Directory of Open Access Journals (Sweden)

    Kristine eStadskleiv

    2014-09-01

    Full Text Available Executive functions are the basis for goal-directed activity and include planning, monitoring, and inhibition, and language seems to play a role in the development of these functions. There is a tradition of studying executive function in both typical and atypical populations, and the present study investigates executive functions in children with severe speech and motor impairments who are communicating using communication aids with graphic symbols, letters and/or words. There are few neuropsychological studies of children in this group and little is known about their cognitive functioning, including executive functions. It was hypothesized that aided communication would tax executive functions more than speech. 29 children using communication aids and 27 naturally speaking children participated. Structured tasks resembling everyday activities, where the action goals had to be reached through communication with a partner, were used to get information about executive functions. The children a directed the partner to perform actions like building a Lego tower from a model the partner could not see and b gave information about an object without naming it to a person who had to guess what object it was. The executive functions of planning, monitoring and impulse control were coded from the children’s on-task behavior. Both groups solved most of the tasks correctly, indicating that aided communicators are able to use language to direct another person to do a complex set of actions. Planning and lack of impulsivity was positively related to task success in both groups. The aided group completed significantly fewer tasks, spent longer time and showed more variation in performance than the comparison group. The aided communicators scored lower on planning and showed more impulsivity than the comparison group, while both groups showed an equal degree of monitoring of the work progress. The results are consistent with the hypothesis that aided language

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

    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 cal ed 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 successful y 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 wil 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.

  20. Functional neuroimaging of visuospatial working memory tasks enables accurate detection of attention deficit and hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    Rubi Hammer

    2015-01-01

    Full Text Available Finding neurobiological markers for neurodevelopmental disorders, such as attention deficit and hyperactivity disorder (ADHD, is a major objective of clinicians and neuroscientists. We examined if functional Magnetic Resonance Imaging (fMRI data from a few distinct visuospatial working memory (VSWM tasks enables accurately detecting cases with ADHD. We tested 20 boys with ADHD combined type and 20 typically developed (TD boys in four VSWM tasks that differed in feedback availability (feedback, no-feedback and reward size (large, small. We used a multimodal analysis based on brain activity in 16 regions of interest, significantly activated or deactivated in the four VSWM tasks (based on the entire participants' sample. Dimensionality of the data was reduced into 10 principal components that were used as the input variables to a logistic regression classifier. fMRI data from the four VSWM tasks enabled a classification accuracy of 92.5%, with high predicted ADHD probability values for most clinical cases, and low predicted ADHD probabilities for most TDs. This accuracy level was higher than those achieved by using the fMRI data of any single task, or the respective behavioral data. This indicates that task-based fMRI data acquired while participants perform a few distinct VSWM tasks enables improved detection of clinical cases.

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

    Science.gov (United States)

    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.

  2. Movement variability in stroke patients and controls performing two upper limb functional tasks: a new assessment methodology

    Directory of Open Access Journals (Sweden)

    Goulermas John Y

    2009-01-01

    Full Text Available Abstract Background In the evaluation of upper limb impairment post stroke there remains a gap between detailed kinematic analyses with expensive motion capturing systems and common clinical assessment tests. In particular, although many clinical tests evaluate the performance of functional tasks, metrics to characterise upper limb kinematics are generally not applicable to such tasks and very limited in scope. This paper reports on a novel, user-friendly methodology that allows for the assessment of both signal magnitude and timing variability in upper limb movement trajectories during functional task performance. In order to demonstrate the technique, we report on a study in which the variability in timing and signal magnitude of data collected during the performance of two functional tasks is compared between a group of subjects with stroke and a group of individually matched control subjects. Methods We employ dynamic time warping for curve registration to quantify two aspects of movement variability: 1 variability of the timing of the accelerometer signals' characteristics and 2 variability of the signals' magnitude. Six stroke patients and six matched controls performed several trials of a unilateral ('drinking' and a bilateral ('moving a plate' functional task on two different days, approximately 1 month apart. Group differences for the two variability metrics were investigated on both days. Results For 'drinking from a glass' significant group differences were obtained on both days for the timing variability of the acceleration signals' characteristics (p = 0.002 and p = 0.008 for test and retest, respectively; all stroke patients showed increased signal timing variability as compared to their corresponding control subject. 'Moving a plate' provided less distinct group differences. Conclusion This initial application establishes that movement variability metrics, as determined by our methodology, appear different in stroke patients as

  3. Task control signals in pediatric Tourette syndrome show evidence of immature and anomalous functional activity

    Directory of Open Access Journals (Sweden)

    Jessica A Church

    2009-11-01

    Full Text Available Tourette Syndrome (TS is a pediatric movement disorder that may affect control signaling in the brain. Previous work has proposed a dual-networks architecture of control processing involving a task-maintenance network and an adaptive control network (Dosenbach et al., 2008. A prior resting-state functional connectivity MRI (rs-fcMRI analysis in TS has revealed functional immaturity in both putative control networks, with “anomalous” correlations (i.e. correlations outside the typical developmental range limited to the adaptive control network (Church et al., 2009. The present study used functional MRI (fMRI to study brain activity related to adaptive control (by studying start-cues signals, and to task-maintenance (by studying signals sustained across a task set. Two hypotheses from the previous rs-fcMRI results were tested. First, adaptive control (i.e., start-cue activity will be altered in TS, including activity inconsistent with typical development (“anomalous”. Second, group differences found in task maintenance (i.e., sustained activity will be consistent with functional immaturity in TS. We examined regions found through a direct comparison of adolescents with and without TS, as well as regions derived from a previous investigation that showed differences between unaffected children and adults. The TS group showed decreased start-cue signal magnitude in regions where start-cue activity is unchanged over typical development, consistent with anomalous adaptive control. The TS group also had higher magnitude sustained signals in frontal cortex regions that overlapped with regions showing differences over typical development, consistent with immature task maintenance in TS. The results demonstrate task-related fMRI signal differences anticipated by the atypical functional connectivity found previously in adolescents with TS, strengthening the evidence for functional immaturity and anomalous signaling in control networks in adolescents

  4. A virtual shopping task for the assessment of executive functions: Validity for people with stroke.

    Science.gov (United States)

    Nir-Hadad, Shira Yama; Weiss, Patrice L; Waizman, Anna; Schwartz, Natalia; Kizony, Rachel

    2017-07-01

    The importance of assessing executive functions (EF) using ecologically valid assessments has been discussed extensively. Due to the difficulty of carrying out such assessments in real-world settings on a regular basis, virtual reality has been proposed as a technique to provide complex functional tasks under a variety of differing conditions while measuring various aspects of performance and controlling for stimuli. The main goal of this study was to examine the discriminant, construct-convergent and ecological validity of the Adapted Four-Item Shopping Task, an assessment of the Instrumental Activity of Daily Living (IADL) of shopping. Nineteen people with stroke, aged 50-85 years, and 20 age- and gender-matched healthy participants performed the shopping task in both the SeeMe Virtual Interactive Shopping environment and a real shopping environment (the hospital cafeteria) in a counterbalanced order. The shopping task outcomes were compared to clinical measures of EF. The findings provided good initial support for the validity of the Adapted Four-Item Shopping Task as an IADL assessment that requires the use of EF for people with stroke. Further studies should examine this task with a larger sample of people with stroke as well as with other populations who have deficits in EF.

  5. Mode-detailed analysis of transmission based directly on Green's functions

    Science.gov (United States)

    Jin, Cailong; Lan, Jin; Zhao, Xuean; Sui, Wenquan

    2016-09-01

    Fisher-Lee relation {bm{t}= {i}bm{Γ}_L^{1/2}bm{G}bm{Γ}^{1/2}_R} t = i Γ L 1 / 2 G Γ R 1 / 2 is a well-established tool to decode the mode information from Green's function and coupling parameters. Using the Bloch eigen-modes of the leads, we show that the {bm{Γ}^{1/2}_{L/R}} Γ L / R 1 / 2 term can be expressed by the Bloch eigen-mode vectors and the wave velocities which give unambiguous algorithm of {bm{Γ}^{1/2}_{L/R}} Γ L / R 1 / 2 in the Fish-Lee relation. Using this approach, we present an accurate and convenient technique to analyze all transport modes and also the dominant channels of an electronic transport system in tight-binding model. We study graphene nanoribbon structures to demonstrate the typical application of our technique.

  6. Deciphering fine molecular details of proteins' structure and function with a Protein Surface Topography (PST) method.

    Science.gov (United States)

    Koromyslova, Anna D; Chugunov, Anton O; Efremov, Roman G

    2014-04-28

    Molecular surfaces are the key players in biomolecular recognition and interactions. Nowadays, it is trivial to visualize a molecular surface and surface-distributed properties in three-dimensional space. However, such a representation trends to be biased and ambiguous in case of thorough analysis. We present a new method to create 2D spherical projection maps of entire protein surfaces and manipulate with them--protein surface topography (PST). It permits visualization and thoughtful analysis of surface properties. PST helps to easily portray conformational transitions, analyze proteins' properties and their dynamic behavior, improve docking performance, and reveal common patterns and dissimilarities in molecular surfaces of related bioactive peptides. This paper describes basic usage of PST with an example of small G-proteins conformational transitions, mapping of caspase-1 intersubunit interface, and intrinsic "complementarity" in the conotoxin-acetylcholine binding protein complex. We suggest that PST is a beneficial approach for structure-function studies of bioactive peptides and small proteins.

  7. Detailed examination of HLA antibody development on renal allograft failure and function.

    Science.gov (United States)

    Zhu, Lan; Lee, Po-Chang; Everly, Matthew J; Terasaki, Paul I

    2008-01-01

    This is a long-term retrospective case-control study. Serial sera were collected over 17 years (1991-2008) from two groups comprised of 29 patients with allograft failure (250 sera) and 25 controls with functioning grafts (305 sera), each control matched by transplant date to one failure-group patient, and all patients tested with single antigen beads. The median follow-up for failure-group patients was 7.3 +/- 4.7 years and 11.8 +/- 4.4 years for controls. HLA alloantibodies appeared in 28 of the 29 failure-group patients (97%) and in 12 of the 25 controls (48%) (p failure (p = 0.001, p = 0.01). DSA against HLA-DQ antigen was found in 13 of 17 graft-failed patients who had received DQ-incompatible transplants (76%) compared with only one of 11 similarly DQ-mismatched control patients (9%) (p 5000) was higher in graft-failed patients than in graft-functioning patients. The time it took for antibodies to develop also differed between groups. HLA antibodies were formed sooner in the failure group compared with the controls (1.7 versus 3.7 years, P failure group patients developed antibodies within one year while none in the control group did. In conclusion, our study reinforces the observation that circulating de novo HLA alloantibodies predict adverse long-term kidney allograft outcomes. The significant negative impact of all alloantibodies calls for clinicians to monitor patients and implement removal therapy when alloantibody is first detected. This may prove a key step in the ongoing attempt to prevent chronic rejection and prolonging renal allograft survival.

  8. Designing an ecological and adaptable virtual task in the context of executive functions.

    Science.gov (United States)

    Klinger, Evelyne; Cao, Xue; Douguet, Anne-Sophie; Fuchs, Philippe

    2009-01-01

    Brain damage is a major cause of disability that often leads to deficits in Executive Functions (EF) with dramatic consequences on activities of daily living. While rehabilitation approaches of the dysexecutive syndrome are still limited, Virtual Reality (VR) has shown its potential to propose innovative intervention strategies based on ecologically valid functional tasks. The purpose of this paper is to present the design process of the Therapeutic Virtual Kitchen (TVK) in which ecological and adaptable virtual tasks may be configured by the therapists for patients' assessment and rehabilitation. The outcomes of a preliminary test of feasibility among members of our laboratory and Kerpape Rehabilitation Center are reported and discussed.

  9. Children's head movements and postural stability as a function of task.

    Science.gov (United States)

    Flatters, Ian; Mushtaq, Faisal; Hill, Liam J B; Rossiter, Anna; Jarrett-Peet, Kate; Culmer, Pete; Holt, Ray; Wilkie, Richard M; Mon-Williams, Mark

    2014-06-01

    Manual dexterity and postural control develop throughout childhood, leading to changes in the synergistic relationships between head, hand and posture. But the postural developments that support complex manual task performance (i.e. beyond pointing and grasping) have not been examined in depth. We report two experiments in which we recorded head and posture data whilst participants simultaneously performed a visuomotor task. In Experiment 1, we explored the extent to which postural stability is affected by concurrently performing a visual and manual task whilst standing (a visual vs. manual-tracking task) in four age groups: 5-6 years (n = 8), 8-9 years (n = 10), 10-11 years (n = 7) and 19-21 years (n = 9). For visual tracking, the children's but not adult's postural movement increased relative to baseline with a larger effect for faster moving targets. In manual tracking, we found greater postural movement in children compared to adults. These data suggest predictive postural compensation mechanisms develop during childhood to improve stability whilst performing visuomotor tasks. Experiment 2 examined the extent to which posture is influenced by manual activity in three age groups of children [5-6 years (n = 14), 7-8 years (n = 25), and 9-10 years (n = 24)] when they were seated, given that many important tasks (e.g. handwriting) are learned and performed whilst seated. We found that postural stability varied in a principled manner as a function of task demands. Children exhibited increased stability when tracing a complex shape (which required less predictive postural adjustment) and decreased stability in an aiming task (which required movements that were more likely to perturb posture). These experiments shed light on the task-dependant relationships that exist between postural control mechanisms and the development of specific types of manual control.

  10. Human factors evaluation of remote afterloading brachytherapy. Volume 2, Function and task analysis

    Energy Technology Data Exchange (ETDEWEB)

    Callan, J.R.; Gwynne, J.W. III; Kelly, T.T.; Muckler, F.A. [Pacific Science and Engineering Group, San Diego, CA (United States); Saunders, W.M.; Lepage, R.P.; Chin, E. [University of California San Diego Medical Center, CA (United States). Div. of Radiation Oncology; Schoenfeld, I.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1995-05-01

    A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the first phase of the project, which involved an extensive function and task analysis of RAB. This analysis identified the functions and tasks in RAB, made preliminary estimates of the likelihood of human error in each task, and determined the skills needed to perform each RAB task. The findings of the function and task analysis served as the foundation for the remainder of the project, which evaluated four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training and qualifications of RAB staff; and organizational practices and policies. At its completion, the project identified and prioritized areas for recommended NRC and industry attention based on all of the evaluations and analyses.

  11. Orangutans (Pongo abelii) seek information about tool functionality in a metacognition tubes task.

    Science.gov (United States)

    Mulcahy, Nicholas J

    2016-11-01

    Nonhuman primates appear to engage in metacognition by knowing when they need to search for relevant information for solving the tubes task. The task involves presenting subjects with a number of tubes with only 1 having food hidden inside. Before choosing, subjects look inside the tubes more often when they do not know which 1 contains the food (hidden trials) compared to when they do know this information (visible trials). It is argued, however, that nonmetacognitive general food searching strategies can explain this looking behavior. To address this issue, 3 orangutans were tested with a novel tubes task in which they were only required to seek information about tool functionality. The results showed that subjects had the ability to search for tool functionality but no subject looked significantly more in hidden trials compared to visible trials. Subjects were retested with the same condition and given a second condition in which the cost of a wrong choice was increased. In both conditions, 2 subjects looked significantly more inside the hidden trials compared to the visible trials. Subjects were also tested with the traditional tubes task in which food was hidden inside 1 tube. All subjects looked inside the tubes significantly more in the hidden trials compared to the visible trials. However, subjects conducted more excessive looks compared to when looking for tool functionality. I suggest that excessive searches may be caused by food being a strong stimulus and discuss the relevance of this possibility for metacognitive research involving the tubes task. (PsycINFO Database Record

  12. Functional activation in the cerebellum during working memory and simple speech tasks.

    Science.gov (United States)

    Durisko, Corrine; Fiez, Julie A

    2010-01-01

    Verbal working memory is the ability to temporarily store and manipulate verbal information. This study tested the predictions of a neuroanatomical model of how the cerebellum contributes to verbal working memory (Desmond et al., 1997). In this model, a large bilateral region in the superior cerebellum is associated with articulatory rehearsal and a right-lateralized region in the inferior cerebellum is associated with the correction of errors within the working memory system. The Desmond et al. (1997) model was based on neuroimaging findings using item recognition tasks and comparisons between working memory and covert rehearsal tasks, whereas in this functional magnetic resonance imaging (fMRI) study we used a delayed serial recall (DSR) task because it relies more heavily on articulatory rehearsal, and our comparison tasks included both overt and covert speech tasks. Our results provide some support for the Desmond et al. (1997) model. In particular, we found multiple activation foci within the superior and inferior sectors of the cerebellum and evidence that these regions show different patterns of activation across working memory and speech tasks. However, the specific patterns of activation were not fully consistent with those reported by Desmond et al. (1997). Namely, our results indicate that activation in the superior sector should be functionally subdivided into a medial focus involved in speech processing and a lateral focus more specific to verbal working memory; the results also indicate that activation in the inferior sector is not uniquely right lateralized. These complex findings speak to the need for future studies to consider the speech-motor aspects of tasks, to investigate the functional significance of adjacent peaks of activation within large regions of cerebellar activation, and to use analysis procedures that support regional distinctions through direct statistical tests. Such studies would help to refine our understanding of how the

  13. COMPARATIVE STUDY BETWEEN TASK SPECIFIC MOTOR IMAGERY WITH MENTAL PRACTICE VERSUS TASK SPECIFIC MIRROR THERAPY ON UPPER LIMB FUNCTIONS FOR SUB ACUTE HEMIPLEGIA

    Directory of Open Access Journals (Sweden)

    Thara. N

    2015-10-01

    Full Text Available Background: Task specific training of upper limb may result in learning of new motor task through transfer after repeated practice. Mirror therapy and motor imagery are effective emerging techniques used as an adjunct in rehabilitation of upper limb function in hemiplegia. The purpose of the study is to find comparative effects of task specific motor imagery with mental practice over task specific mirror therapy on upper limb functional activities for subjects with sub acute hemiplegia. Method: An experimental study design with two groups conducted on 30 subjects with sub-acute hemiplegic. Thirty subjects randomised, 15 subjects into group A and 15 into group B. Group A subjects received task specific motor imagery with mental practice thrice a week for 10 weeks and Group B received task specific mirror therapy thrice a week for 10 weeks. In both groups, each session consisted of 60 minutes. The outcome measure such as Action Research Arm Test (ARAT was measured before and after 10 weeks of intervention. Results: Comparison of post intervention means of ARAT using Independent t test and Mann-Whitney Test showed that there is no statistically significant difference in grasp and gross movement between the groups and there is a statistically significant difference in grip, pinch and total score between the groups. Conclusion: The present study concludes that 10 weeks of task specific motor imagery with mental practice and task specific mirror therapy both shown significant effect on improvement of upper extremity function. However, greater percentage of improvement was found using task specific motor imagery with mental practice in hand function when compared to task specific mirror therapy.

  14. Human factors evaluation of teletherapy: Function and task analysis. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Kaye, R.D.; Henriksen, K.; Jones, R. [Hughes Training, Inc., Falls Church, VA (United States); Morisseau, D.S.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1995-07-01

    As a treatment methodology, teletherapy selectively destroys cancerous and other tissue by exposure to an external beam of ionizing radiation. Sources of radiation are either a radioactive isotope, typically Cobalt-60 (Co-60), or a linear accelerator. Records maintained by the NRC have identified instances of teletherapy misadministration where the delivered radiation dose has differed from the radiation prescription (e.g., instances where fractions were delivered to the wrong patient, to the wrong body part, or were too great or too little with respect to the defined treatment volume). Both human error and machine malfunction have led to misadministrations. Effective and safe treatment requires a concern for precision and consistency of human-human and human-machine interactions throughout the course of therapy. The present study is the first part of a series of human factors evaluations for identifying the root causes that lead to human error in the teletherapy environment. The human factors evaluations included: (1) a function and task analysis of teletherapy activities, (2) an evaluation of the human-system interfaces, (3) an evaluation of procedures used by teletherapy staff, (4) an evaluation of the training and qualifications of treatment staff (excluding the oncologists), (5) an evaluation of organizational practices and policies, and (6) an identification of problems and alternative approaches for NRC and industry attention. The present report addresses the function and task analysis of teletherapy activities and provides the foundation for the conduct of the subsequent evaluations. The report includes sections on background, methodology, a description of the function and task analysis, and use of the task analysis findings for the subsequent tasks. The function and task analysis data base also is included.

  15. Shoulder Strength Requirements for Upper Limb Functional Tasks: Do age and Rotator Cuff Tear Status Matter?

    Science.gov (United States)

    Santago, Anthony C; Vidt, Meghan E; Li, Xiaotong; Tuohy, Christopher J; Poehling, Gary G; Freehill, Michael T; Saul, Katherine R

    2017-07-17

    Understanding upper limb strength requirements for daily tasks is imperative for early detection of strength loss that may progress to disability due to age or rotator cuff tear. We quantified shoulder strength requirements for five upper limb tasks performed by three groups: uninjured young adults and older adults, and older adults with a degenerative supraspinatus tear prior to repair. Musculoskeletal models were developed for each group representing age, sex, and tear-related strength losses. Percentage of available strength used was quantified for the subset of tasks requiring the largest amount of shoulder strength. Significant differences in strength requirements existed across tasks: upward reach 105° required the largest average strength; axilla wash required the largest peak strength. However, there were limited differences across participant groups. Older adults with and without a tear used a larger percentage of their shoulder elevation (p<.001, p<.001) and external rotation (p<.001, p=.017) strength than the young adults respectively. Presence of a tear signficantly increased percentage of internal rotation strength compared to young (p<.001) and uninjured older adults (p=.008). Marked differences in strength demand across tasks indicate the need for evaluating a diversity of functional tasks to effectively detect early strength loss which may lead to disability.

  16. A detailed study on the use of polynomial functions for modeling geometric distortion in magnetic resonance imaging.

    Science.gov (United States)

    Wang, Deming; Yang, Zhengyi

    2008-03-01

    The use of polynomial functions for modeling geometric distortion in magnetic resonance imaging (MRI) that arises from scanner's hardware imperfection is studied in detail. In this work, the geometric distortion data from four representative MRI systems were used. Modeling of these data using polynomial functions of the fourth, fifth, sixth, and seventh orders was carried out. In order to investigate how this modeling performed for different size and shape of the volume of interest, the modeling was carried out for three different volumes of interest (VOI): a cube, a cylinder, and a sphere. The modeling's goodness was assessed using both the maximum and mean absolute errors. The modeling results showed that (i) for the cube VOI there appears to be an optimal polynomial function that gives the least modeling errors and the sixth order polynomial was found to be the optimal polynomial function for the size of the cubic VOI considered in the present work; (ii) for the cylinder VOI, all four polynomials performed approximately equally well but a trend of a slight decrease in the mean absolute error with the increasing order of the polynomial was noted; and (iii) for the sphere VOI, the maximum absolute error showed some variations with the order of the polynomial, with the fourth order polynomial producing the smallest maximum absolute errors. It is further noted that extrapolation could lead to very large errors so any extrapolation needs to be avoided. A detailed analysis on the modeling errors is presented.

  17. The implementation of the functional task exercise programme for elderly people living at home

    NARCIS (Netherlands)

    Fleuren, Margot A. H.; Vrijkotte, Susan; Jans, Marielle P.; Pin, Renske; van Hespen, Ariette; van Meeteren, Nico L. U.; Siemonsma, Petra C.

    2012-01-01

    Background: The Functional Task Exercise programme is an evidence-based exercise programme for elderly people living at home. It enhances physical capacity with sustainable effects. FTE is provided by physiotherapists and remedial therapists. Although the intervention was found to be effective in a

  18. Experimental study on the effects of visualized functionally abstracted information on process control tasks

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Dong-Han [School of Computing Science, Middlesex University, The Burroughs London, London NW4 4BT (United Kingdom)], E-mail: d.ham@mdx.ac.uk; Yoon, Wan Chul [Department of Industrial Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701 (Korea, Republic of); Han, Byoung-Tae [Global Consumer Group, Citibank Korea Inc., Shinmoon-ro, Chongro-gu, Seoul 110-762 (Korea, Republic of)

    2008-02-15

    Two distinct design problems of information display for process control are information content representation and visual form design. Regarding information content, we experimentally showed the effectiveness of functionally abstracted information without the benefits of sophisticated graphical presentation in various task situations. However, since it is obvious that the effects of the information display are also influenced by display formats (i.e., visual forms) as well as the information content, further research was required to investigate the effectiveness of visualized functionally abstracted information. For this purpose, this study conducted an experiment in complex process control tasks (operation and fault diagnosis). The experimental purposes were to confirm the effectiveness of the functionally abstracted information visualized with emergent features or peculiar geometric forms and to examine the additional effects of the visualization on task performance. The results showed that functionally abstracted information presented with sophisticated visual forms helped operators perform process control tasks in more efficient and safe way. The results also indicated the importance of explicit visualization of goal-means relation between higher and lower abstraction levels. Lastly, this study proposed a framework for designing visual forms for process control display.

  19. The implementation of the functional task exercise programme for elderly people living at home

    NARCIS (Netherlands)

    Fleuren, Margot A. H.; Vrijkotte, Susan; Jans, Marielle P.; Pin, Renske; van Hespen, Ariette; van Meeteren, Nico L. U.; Siemonsma, Petra C.

    2012-01-01

    Background: The Functional Task Exercise programme is an evidence-based exercise programme for elderly people living at home. It enhances physical capacity with sustainable effects. FTE is provided by physiotherapists and remedial therapists. Although the intervention was found to be effective in a

  20. The Function of Task-based Language Teaching in English teaching

    Institute of Scientific and Technical Information of China (English)

    Li; he; ying; Niu; lulu

    2015-01-01

    With the continuous reform of English teaching,Task-based Language Teaching(TBLT) comes out and is promoted.The author introduces and analyzes the meaning of TBLT,studies its’ function in English teaching to find out its’ necessity.

  1. The Function of Task-based Language Teaching in English teaching

    Institute of Scientific and Technical Information of China (English)

    Li he ying; Niululu

    2015-01-01

    With the continuous reform of English teaching,Task-based Language Teaching (TBLT) comes out and is promoted.The author introduces and analyzes the meaning of TBLT,studies its' function in English teaching to find out its'necessity.

  2. Acoustic Variations in Adductor Spasmodic Dysphonia as a Function of Speech Task.

    Science.gov (United States)

    Sapienza, Christine M.; Walton, Suzanne; Murry, Thomas

    1999-01-01

    Acoustic phonatory events were identified in 14 women diagnosed with adductor spasmodic dysphonia (ADSD), a focal laryngeal dystonia that disturbs phonatory function, and compared with those of 14 age-matched women with no vocal dysfunction. Findings indicated ADSD subjects produced more aberrant acoustic events than controls during tasks of…

  3. Enhancing the Executive Functions of 3-Year-Olds in the Dimensional Change Card Sort Task

    Science.gov (United States)

    Perone, Sammy; Molitor, Stephen J.; Buss, Aaron T.; Spencer, John P.; Samuelson, Larissa K.

    2015-01-01

    Executive functions enable flexible thinking, something young children are notoriously bad at. For instance, in the dimensional change card sort (DCCS) task, 3-year-olds can sort cards by one dimension (shape), but continue to sort by this dimension when asked to switch (to color). This study tests a prediction of a dynamic neural field model that…

  4. Rehabilitation of executive function: facilitation of effective goal management on complex tasks using periodic auditory alerts.

    Science.gov (United States)

    Manly, Tom; Hawkins, Kari; Evans, Jon; Woldt, Karina; Robertson, Ian H

    2002-01-01

    The 'dysexecutive syndrome' represents a major challenge to functional recovery and adaptation following brain injury--and an important target for rehabilitation. Previous reports of everyday difficulties, and performance on complex, life-like tasks, indicate that an adequately represented goal may become neglected as patients become overly engaged in current activity. Here we examine whether the provision of brief auditory stimuli, acting to interrupt current activity and to cue patients to consider their overall goal, would improve performance in a complex task. Ten brain injured patients completed a modification of Shallice and Burgess' Six Elements task under two conditions. In the 'Hotel' test, the patients were asked to try and do some of each of five sub-tasks within 15 min. As the total time to complete all of the tasks would exceed an hour, the measure emphasises patients' ability to monitor the time, switch between the tasks and keep track of their intentions. Without the external auditory cues, the patients performed significantly more poorly than age- and IQ-matched control volunteers, a common error being to continue performing one task to the detriment of beginning or allocating sufficient time to others. When exposed to the interrupting tones, however, their performance was both significantly improved and no longer significantly different from the control group on important variables. The results have value in assessment in helping to attribute poor performance to 'goal neglect' rather than, for example, poor memory or comprehension. They also suggest that providing environmental support to one aspect of executive function may facilitate monitoring and behavioural flexibility--and therefore the useful expression of other skills that may be relatively intact.

  5. Can task-switching training enhance executive control functioning in children with attention deficit/-hyperactivity disorder?

    Directory of Open Access Journals (Sweden)

    Jutta eKray

    2012-01-01

    Full Text Available The key cognitive impairments of children with attention deficit/-hyperactivity disorder (ADHD include executive control functions such as inhibitory control, task switching, and working memory. In this training study we examined whether task-switching training leads to improvements in these functions. Twenty children with combined type ADHD and stable methylphenidate medication performed a single-task and a task-switching training in a crossover training design. The children were randomly assigned to one of two groups. One group started with the single-task training and then performed the task-switching training and the other group vice versa. The effectiveness of the task-switching training was measured as performance improvements (relative to the single-task training on a structurally similar but new switching task and on other executive control tasks measuring inhibitory control and verbal working memory as well as on fluid intelligence (reasoning. The children in both groups showed improvements in task switching, that is, a reduction of switching costs, but not in performing the single tasks across four training sessions. Moreover, the task-switching training lead to selective enhancements in task-switching performance, that is, the reduction of task-switching costs was found to be larger after task-switching than after single-task training. Similar selective improvements were observed for inhibitory control and verbal working memory, but not for reasoning. Results of this study suggest that task-switching training is an effective cognitive intervention that helps to enhance executive control functioning in children with ADHD.

  6. Relationships Among Lower Body Strength, Power and Performance of Functional Tasks

    Science.gov (United States)

    Ploutz-Snyder, Lori

    2010-01-01

    There is a large degree of variability among crewmembers with respect to decrements in muscle strength and power following long duration spaceflight, ranging from 0 to approx.30% reductions. The purpose of this study was to investigate the influence of varying decrements in lower body muscle strength and power (relative to body weight) on the performance of 2 occupationally relevant tasks (ladder climb and supine egress & walk). Seventeen participants with leg strength similar to US crewmembers performed a leg press power test, an isokinetic knee extension strength test and they were asked to complete the 2 functional tasks as quickly as possible. On additional test days the participants were asked to repeat the functional tasks under 3 conditions where a different external load was applied each time using a weighted suit in order to experimentally manipulate participants strength/body weight and power/body weight ratios. The weight in the suit ranged from 20-120% of body weight and was distributed in proportion to limb segment weights to minimize changes in center of gravity. The ladder task consisted of climbing 40 rungs on a ladder treadmill as fast as possible. The supine egress & walk task consisted of rising from a supine position and walking through an obstacle course. Results show a relatively linear relationship between strength/body weight and task time and power/body weight with task time such that the fastest performance times are associated with higher strength and power with about half the variance in task time is accounted for by a single variable (either strength or power). For the average person, a 20% reduction in power/body weight (from 18 to 14.4 W/kg) induces an increase (slowing) of about 10 seconds in the ladder climb task from 14 to 24 seconds (approx.70%) and a slowing of the supine egress & walk task from 14 to 21 seconds (approx.50%). Similar relationships were observed with strength/body weight and task performance. For the average

  7. Association between two distinct executive tasks in schizophrenia: a functional transcranial Doppler sonography study

    Directory of Open Access Journals (Sweden)

    Theodoridou Anastasia

    2006-05-01

    Full Text Available Abstract Background Schizophrenia is a severe mental disorder involving impairments in executive functioning, which are important cognitive processes that can be assessed by planning tasks such as the Stockings of Cambridge (SOC, and tasks of rule learning/abstraction such as the Wisconsin Card Sorting Test (WCST. We undertook this study to investigate the association between performance during separate phases of SOC and WCST, including mean cerebral blood flow velocity (MFV measurements in chronic schizophrenia. Methods Functional transcranial Doppler sonography (fTCD was used to assess bilateral MFV changes in the middle (MCA and anterior (ACA cerebral arteries. Twenty-two patients with chronic schizophrenia and 20 healthy subjects with similar sociodemographic characteristics performed SOC and WCST during fTCD measurements of the MCA and the ACA. The SOC was varied in terms of easy and difficult problems, and also in terms of separate phases, namely mental planning and movement execution. The WCST performance was assessed separately for maintaining set and set shifting. This allowed us to examine the impact of problem difficulty and the impact of separate phases of a planning task on distinct intervals of WCST. Simultaneous registration of MFV was carried out to investigate the linkage of brain perfusion during the tasks. Results In patients, slowing of movement execution during easy problems (SOC was associated with slowing during maintaining set (WCST (P Conclusion The results of this study demonstrate performance and brain perfusion abnormalities in the association pattern of two different tasks of executive functioning in schizophrenia, and they support the notion that executive functions have a pathological functional correlate predominantly in the lateral hemispheres of the brain. This study also underpins the scientific potential of fTCD in assessing brain perfusion in patients with schizophrenia.

  8. Attentional costs of visually guided walking: effects of age, executive function and stepping-task demands.

    Science.gov (United States)

    Mazaheri, Masood; Roerdink, Melvyn; Bood, Robert Jan; Duysens, Jacques; Beek, Peter J; Peper, C Lieke E

    2014-01-01

    During walking, attention needs to be flexibly allocated to deal with varying environmental constraints. This ability may be affected by aging and lower overall executive function. The present study examined the influence of aging and executive function on the attentional costs of visually guided walking under different task demands. Three groups, young adults (n=15) and elderly adults with higher (n=16) and lower (n=10) executive function, walked on a treadmill in three conditions: uncued walking and walking with regular and irregular patterns of visual stepping targets projected onto the belt. Attentional costs were assessed using a secondary probe reaction time task and corrected by subtracting baseline single-task reaction time, yielding an estimate of the additional attentional costs of each walking condition. We found that uncued walking was more attentionally demanding for elderly than for young participants. In young participants, the attentional costs increased significantly from uncued to regularly cued to irregularly cued walking, whereas for the higher executive function group, attentional costs only increased significantly from regularly cued to irregularly cued walking. For the group with lower executive function, no significant differences were observed. The observed decreased flexibility of elderly, especially those with lower executive function, to allocate additional attentional resources to more challenging walking conditions may be attributed to the already increased attentional costs of uncued walking, presumably required for visuomotor and/or balance control of walking.

  9. Choosing Your Poison: Optimizing Simulator Visual System Selection as a Function of Operational Tasks

    Science.gov (United States)

    Sweet, Barbara T.; Kaiser, Mary K.

    2013-01-01

    Although current technology simulator visual systems can achieve extremely realistic levels they do not completely replicate the experience of a pilot sitting in the cockpit, looking at the outside world. Some differences in experience are due to visual artifacts, or perceptual features that would not be present in a naturally viewed scene. Others are due to features that are missing from the simulated scene. In this paper, these differences will be defined and discussed. The significance of these differences will be examined as a function of several particular operational tasks. A framework to facilitate the choice of visual system characteristics based on operational task requirements will be proposed.

  10. Functional mutagenesis screens reveal the 'cap structure' formation in disulfide-bridge free TASK channels.

    Science.gov (United States)

    Goldstein, Matthias; Rinné, Susanne; Kiper, Aytug K; Ramírez, David; Netter, Michael F; Bustos, Daniel; Ortiz-Bonnin, Beatriz; González, Wendy; Decher, Niels

    2016-01-22

    Two-pore-domain potassium (K2P) channels have a large extracellular cap structure formed by two M1-P1 linkers, containing a cysteine for dimerization. However, this cysteine is not present in the TASK-1/3/5 subfamily. The functional role of the cap is poorly understood and it remained unclear whether K2P channels assemble in the domain-swapped orientation or not. Functional alanine-mutagenesis screens of TASK-1 and TRAAK were used to build an in silico model of the TASK-1 cap. According to our data the cap structure of disulfide-bridge free TASK channels is similar to that of other K2P channels and is most likely assembled in the domain-swapped orientation. As the conserved cysteine is not essential for functional expression of all K2P channels tested, we propose that hydrophobic residues at the inner leaflets of the cap domains can interact with each other and that this way of stabilizing the cap is most likely conserved among K2P channels.

  11. Investigating executive functions in children with severe speech and movement disorders using structured tasks.

    Science.gov (United States)

    Stadskleiv, Kristine; von Tetzchner, Stephen; Batorowicz, Beata; van Balkom, Hans; Dahlgren-Sandberg, Annika; Renner, Gregor

    2014-01-01

    Executive functions are the basis for goal-directed activity and include planning, monitoring, and inhibition, and language seems to play a role in the development of these functions. There is a tradition of studying executive function in both typical and atypical populations, and the present study investigates executive functions in children with severe speech and motor impairments who are communicating using communication aids with graphic symbols, letters, and/or words. There are few neuropsychological studies of children in this group and little is known about their cognitive functioning, including executive functions. It was hypothesized that aided communication would tax executive functions more than speech. Twenty-nine children using communication aids and 27 naturally speaking children participated. Structured tasks resembling everyday activities, where the action goals had to be reached through communication with a partner, were used to get information about executive functions. The children (a) directed the partner to perform actions like building a Lego tower from a model the partner could not see and (b) gave information about an object without naming it to a person who had to guess what object it was. The executive functions of planning, monitoring, and impulse control were coded from the children's on-task behavior. Both groups solved most of the tasks correctly, indicating that aided communicators are able to use language to direct another person to do a complex set of actions. Planning and lack of impulsivity was positively related to task success in both groups. The aided group completed significantly fewer tasks, spent longer time and showed more variation in performance than the comparison group. The aided communicators scored lower on planning and showed more impulsivity than the comparison group, while both groups showed an equal degree of monitoring of the work progress. The results are consistent with the hypothesis that aided language tax

  12. Task-modulated activation and functional connectivity of the temporal and frontal areas during speech comprehension.

    Science.gov (United States)

    Yue, Q; Zhang, L; Xu, G; Shu, H; Li, P

    2013-05-01

    There is general consensus in the literature that a distributed network of temporal and frontal brain areas is involved in speech comprehension. However, how active versus passive tasks modulate the activation and the functional connectivity of the critical brain areas is not clearly understood. In this study, we used functional magnetic resonance imaging (fMRI) to identify intelligibility and task-related effects in speech comprehension. Participants performed a semantic judgment task on normal and time-reversed sentences, or passively listened to the sentences without making an overt response. The subtraction analysis demonstrated that passive sentence comprehension mainly engaged brain areas in the left anterior and posterior superior temporal sulcus and middle temporal gyrus (aSTS/MTG and pSTS/MTG), whereas active sentence comprehension recruited bilateral frontal regions in addition to the aSTS/MTG and pSTS/MTG regions. Functional connectivity analysis revealed that during passive sentence comprehension, the left aSTS/MTG was functionally connected with the left Heschl's gyrus (HG) and bilateral superior temporal gyrus (STG) but no area was functionally connected with the left pSTS/MTG; during active sentence comprehension, however, both the left aSTS/MTG and pSTS/MTG were functionally connected with bilateral superior temporal and inferior frontal areas. While these results are consistent with the view that the ventral stream of the temporo-frontal network subserves semantic processing, our findings further indicate that both the activation and the functional connectivity of the temporal and frontal areas are modulated by task demands. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Prediction of rat behavior outcomes in memory tasks using functional connections among neurons.

    Science.gov (United States)

    Lu, Hu; Yang, Shengtao; Lin, Longnian; Li, Baoming; Wei, Hui

    2013-01-01

    Analyzing the neuronal organizational structures and studying the changes in the behavior of the organism is key to understanding cognitive functions of the brain. Although some studies have indicated that spatiotemporal firing patterns of neuronal populations have a certain relationship with the behavioral responses, the issues of whether there are any relationships between the functional networks comprised of these cortical neurons and behavioral tasks and whether it is possible to take advantage of these networks to predict correct and incorrect outcomes of single trials of animals are still unresolved. This paper presents a new method of analyzing the structures of whole-recorded neuronal functional networks (WNFNs) and local neuronal circuit groups (LNCGs). The activity of these neurons was recorded in several rats. The rats performed two different behavioral tasks, the Y-maze task and the U-maze task. Using the results of the assessment of the WNFNs and LNCGs, this paper describes a realization procedure for predicting the behavioral outcomes of single trials. The methodology consists of four main parts: construction of WNFNs from recorded neuronal spike trains, partitioning the WNFNs into the optimal LNCGs using social community analysis, unsupervised clustering of all trials from each dataset into two different clusters, and predicting the behavioral outcomes of single trials. The results show that WNFNs and LNCGs correlate with the behavior of the animal. The U-maze datasets show higher accuracy for unsupervised clustering results than those from the Y-maze task, and these datasets can be used to predict behavioral responses effectively. The results of the present study suggest that a methodology proposed in this paper is suitable for analysis of the characteristics of neuronal functional networks and the prediction of rat behavior. These types of structures in cortical ensemble activity may be critical to information representation during the execution of

  14. Prediction of rat behavior outcomes in memory tasks using functional connections among neurons.

    Directory of Open Access Journals (Sweden)

    Hu Lu

    Full Text Available BACKGROUND: Analyzing the neuronal organizational structures and studying the changes in the behavior of the organism is key to understanding cognitive functions of the brain. Although some studies have indicated that spatiotemporal firing patterns of neuronal populations have a certain relationship with the behavioral responses, the issues of whether there are any relationships between the functional networks comprised of these cortical neurons and behavioral tasks and whether it is possible to take advantage of these networks to predict correct and incorrect outcomes of single trials of animals are still unresolved. METHODOLOGY/PRINCIPAL FINDINGS: This paper presents a new method of analyzing the structures of whole-recorded neuronal functional networks (WNFNs and local neuronal circuit groups (LNCGs. The activity of these neurons was recorded in several rats. The rats performed two different behavioral tasks, the Y-maze task and the U-maze task. Using the results of the assessment of the WNFNs and LNCGs, this paper describes a realization procedure for predicting the behavioral outcomes of single trials. The methodology consists of four main parts: construction of WNFNs from recorded neuronal spike trains, partitioning the WNFNs into the optimal LNCGs using social community analysis, unsupervised clustering of all trials from each dataset into two different clusters, and predicting the behavioral outcomes of single trials. The results show that WNFNs and LNCGs correlate with the behavior of the animal. The U-maze datasets show higher accuracy for unsupervised clustering results than those from the Y-maze task, and these datasets can be used to predict behavioral responses effectively. CONCLUSIONS/SIGNIFICANCE: The results of the present study suggest that a methodology proposed in this paper is suitable for analysis of the characteristics of neuronal functional networks and the prediction of rat behavior. These types of structures in cortical

  15. Resting-State and Task-Based Functional Brain Connectivity in Developmental Dyslexia.

    Science.gov (United States)

    Schurz, Matthias; Wimmer, Heinz; Richlan, Fabio; Ludersdorfer, Philipp; Klackl, Johannes; Kronbichler, Martin

    2015-10-01

    Reading requires the interaction between multiple cognitive processes situated in distant brain areas. This makes the study of functional brain connectivity highly relevant for understanding developmental dyslexia. We used seed-voxel correlation mapping to analyse connectivity in a left-hemispheric network for task-based and resting-state fMRI data. Our main finding was reduced connectivity in dyslexic readers between left posterior temporal areas (fusiform, inferior temporal, middle temporal, superior temporal) and the left inferior frontal gyrus. Reduced connectivity in these networks was consistently present for 2 reading-related tasks and for the resting state, showing a permanent disruption which is also present in the absence of explicit task demands and potential group differences in performance. Furthermore, we found that connectivity between multiple reading-related areas and areas of the default mode network, in particular the precuneus, was stronger in dyslexic compared with nonimpaired readers.

  16. The scaling behavior of hand motions reveals self-organization during an executive function task

    Science.gov (United States)

    Anastas, Jason R.; Stephen, Damian G.; Dixon, James A.

    2011-05-01

    Recent approaches to cognition explain cognitive phenomena in terms of interaction-dominant dynamics. In the current experiment, we extend this approach to executive function, a construct used to describe flexible, goal-oriented behavior. Participants were asked to perform a widely used executive function task, card sorting, under two conditions. In one condition, participants were given a rule with which to sort the cards. In the other condition, participants had to induce the rule from experimenter feedback. The motion of each participant’s hand was tracked during the sorting task. Detrended fluctuation analysis was performed on the inter-point time series using a windowing strategy to capture changes over each trial. For participants in the induction condition, the Hurst exponent sharply increased and then decreased. The Hurst exponents for the explicit condition did not show this pattern. Our results suggest that executive function may be understood in terms of changes in stability that arise from interaction-dominant dynamics.

  17. The prefrontal cortex: insights from functional neuroimaging using cognitive activation tasks

    Energy Technology Data Exchange (ETDEWEB)

    Goethals, Ingeborg; Van de Wiele, Christophe; Dierckx, Rudi [Division of Nuclear Medicine, Polikliniek 7, Ghent University Hospital, De Pintelaan 185, 9000, Ghent (Belgium); Audenaert, Kurt [Department of Psychiatry and Medical Psychology, Ghent University Hospital, Ghent (Belgium)

    2004-03-01

    This review presents neuroimaging studies which have explored the functional anatomy of a variety of cognitive processes represented by the prefrontal cortex (PFC). Overall, these studies have demonstrated that standard prefrontal neuroactivation tasks recruit a widely distributed network within the brain of which the PFC consistently forms a part. As such, these results are in keeping with the notion that executive functions within the PFC rely not only on anterior (mainly prefrontal) brain areas, but also on posterior (mainly parietal) brain regions. Moreover, intervention of similar brain regions in a large number of different executive tasks suggests that higher-level cognitive functions may best be understood in terms of an interactive network of specialised anterior as well as posterior brain regions. (orig.)

  18. Videogame training strategy-induced change in brain function during a complex visuomotor task.

    Science.gov (United States)

    Lee, Hyunkyu; Voss, Michelle W; Prakash, Ruchika Shaurya; Boot, Walter R; Vo, Loan T K; Basak, Chandramallika; Vanpatter, Matt; Gratton, Gabriele; Fabiani, Monica; Kramer, Arthur F

    2012-07-01

    Although changes in brain function induced by cognitive training have been examined, functional plasticity associated with specific training strategies is still relatively unexplored. In this study, we examined changes in brain function during a complex visuomotor task following training using the Space Fortress video game. To assess brain function, participants completed functional magnetic resonance imaging (fMRI) before and after 30 h of training with one of two training regimens: Hybrid Variable-Priority Training (HVT), with a focus on improving specific skills and managing task priority, or Full Emphasis Training (FET), in which participants simply practiced the game to obtain the highest overall score. Control participants received only 6 h of FET. Compared to FET, HVT learners reached higher performance on the game and showed less brain activation in areas related to visuo-spatial attention and goal-directed movement after training. Compared to the control group, HVT exhibited less brain activation in right dorsolateral prefrontal cortex (DLPFC), coupled with greater performance improvement. Region-of-interest analysis revealed that the reduction in brain activation was correlated with improved performance on the task. This study sheds light on the neurobiological mechanisms of improved learning from directed training (HVT) over non-directed training (FET), which is related to visuo-spatial attention and goal-directed motor planning, while separating the practice-based benefit, which is related to executive control and rule management.

  19. Functional connectivity among spike trains in neural assemblies during rat working memory task.

    Science.gov (United States)

    Xie, Jiacun; Bai, Wenwen; Liu, Tiaotiao; Tian, Xin

    2014-11-01

    Working memory refers to a brain system that provides temporary storage to manipulate information for complex cognitive tasks. As the brain is a more complex, dynamic and interwoven network of connections and interactions, the questions raised here: how to investigate the mechanism of working memory from the view of functional connectivity in brain network? How to present most characteristic features of functional connectivity in a low-dimensional network? To address these questions, we recorded the spike trains in prefrontal cortex with multi-electrodes when rats performed a working memory task in Y-maze. The functional connectivity matrix among spike trains was calculated via maximum likelihood estimation (MLE). The average connectivity value Cc, mean of the matrix, was calculated and used to describe connectivity strength quantitatively. The spike network was constructed by the functional connectivity matrix. The information transfer efficiency Eglob was calculated and used to present the features of the network. In order to establish a low-dimensional spike network, the active neurons with higher firing rates than average rate were selected based on sparse coding. The results show that the connectivity Cc and the network transfer efficiency Eglob vaired with time during the task. The maximum values of Cc and Eglob were prior to the working memory behavior reference point. Comparing with the results in the original network, the feature network could present more characteristic features of functional connectivity.

  20. Multicenter validation of a bedside antisaccade task as a measure of executive function

    Science.gov (United States)

    Hellmuth, J.; Mirsky, J.; Heuer, H.W.; Matlin, A.; Jafari, A.; Garbutt, S.; Widmeyer, M.; Berhel, A.; Sinha, L.; Miller, B.L.; Kramer, J.H.

    2012-01-01

    Objective: To create and validate a simple, standardized version of the antisaccade (AS) task that requires no specialized equipment for use as a measure of executive function in multicenter clinical studies. Methods: The bedside AS (BAS) task consisted of 40 pseudorandomized AS trials presented on a laptop computer. BAS performance was compared with AS performance measured using an infrared eye tracker in normal elders (NE) and individuals with mild cognitive impairment (MCI) or dementia (n = 33). The neuropsychological domain specificity of the BAS was then determined in a cohort of NE, MCI, and dementia (n = 103) at UCSF, and the BAS was validated as a measure of executive function in a 6-center cohort (n = 397) of normal adults and patients with a variety of brain diseases. Results: Performance on the BAS and laboratory AS task was strongly correlated and BAS performance was most strongly associated with neuropsychological measures of executive function. Even after controlling for disease severity and processing speed, BAS performance was associated with multiple assessments of executive function, most strongly the informant-based Frontal Systems Behavior Scale. Conclusions: The BAS is a simple, valid measure of executive function in aging and neurologic disease. PMID:22573640

  1. Differences in Neural Activation as a Function of Risk-taking Task Parameters

    Directory of Open Access Journals (Sweden)

    Eliza eCongdon

    2013-09-01

    Full Text Available Despite evidence supporting a relationship between impulsivity and naturalistic risk-taking, the relationship of impulsivity with laboratory-based measures of risky decision-making remains unclear. One factor contributing to this gap in our understanding is the degree to which different risky decision-making tasks vary in their details. We conducted an fMRI investigation of the Angling Risk Task (ART, which is an improved behavioral measure of risky decision-making. In order to examine whether the observed pattern of neural activation was specific to the ART or generalizable, we also examined correlates of the Balloon Analogue Risk Taking (BART task in the same sample of 23 healthy adults. Exploratory analyses were conducted to examine the relationship between neural activation, performance, impulsivity and self-reported risk-taking. While activation in a valuation network was associated with reward tracking during the ART but not the BART, increased fronto-cingulate activation was seen during risky choice trials in the BART as compared to the ART. Thus, neural activation during risky decision-making trials differed between the two tasks, and this observation was likely driven by differences in task parameters, namely the absence vs. presence of ambiguity and/or stationary vs. increasing probability of loss on the ART and BART, respectively. Exploratory association analyses suggest that sensitivity of neural response to the magnitude of potential reward during the ART was associated with a suboptimal performance strategy, higher scores on a scale of dysfunctional impulsivity and a greater likelihood of engaging in risky behaviors, while this pattern was not seen for the BART. Our results suggest that the ART is decomposable and associated with distinct patterns of neural activation; this represents a preliminary step towards characterizing a behavioral measure of risky decision-making that may support a better understanding of naturalistic risk-taking.

  2. Musical Training, Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual‐Task Performance

    National Research Council Canada - National Science Library

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-01-01

    ...‐task performance, musicians also outperformed non‐musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest...

  3. Cortical reorganization during PASAT task in MS patients with preserved working memory functions.

    Science.gov (United States)

    Forn, C; Barros-Loscertales, A; Escudero, J; Belloch, V; Campos, S; Parcet, M A; Avila, C

    2006-06-01

    Cortical reorganization in multiple sclerosis (MS) is defined as a compensatory mechanism which requires MS patients to overactivate specific brain areas in order to perform the task as controls. To investigate this process with the Paced Auditory Serial Addition Test (PASAT) task, we selected 15 MS patients who performed the PASAT task within-normal limits and 10 healthy controls. Once selected, we used functional magnetic resonance imaging (fMRI) to investigate brain areas involved in PASAT performance in both groups. Results showed that the task activated the left frontal (BA6 and 9) and parietal cortex (BA7 and 40) in both groups, but MS patients showed a stronger activation in the left prefrontal cortex (BA9, 44 and 45) when compared with controls. These results confirmed those obtained post hoc by Audoin et al. [Audoin, B., Ibarrola, D., Ranjeva, J.P., Confort-Gouny, S., Malikova, I., Ali-Chérif, A.M., Pelletier, J., Cozzone, P., et al., 2003. Compensatory cortical activation observed by fMRI during cognitive task at the earliest stage of MS. Hum. Brain Mapp. 20, 51-58], and we interpreted this as showing true cortical reorganization.

  4. Space shuttle/food system study. Volume 2, Appendix G: Ground support system analysis. Appendix H: Galley functional details analysis

    Science.gov (United States)

    1974-01-01

    The capabilities for preflight feeding of flight personnel and the supply and control of the space shuttle flight food system were investigated to determine ground support requirements; and the functional details of an onboard food system galley are shown in photographic mockups. The elements which were identified as necessary to the efficient accomplishment of ground support functions include the following: (1) administration; (2) dietetics; (3) analytical laboratories; (4) flight food warehouse; (5) stowage module assembly area; (6) launch site module storage area; (7) alert crew restaurant and disperse crew galleys; (8) ground food warehouse; (9) manufacturing facilities; (10) transport; and (11) computer support. Each element is discussed according to the design criteria of minimum cost, maximum flexibility, reliability, and efficiency consistent with space shuttle requirements. The galley mockup overview illustrates the initial operation configuration, food stowage locations, meal assembly and serving trays, meal preparation configuration, serving, trash management, and the logistics of handling and cleanup equipment.

  5. Determination of language lateralization using functional MRI during the performance of shiritori tasks in neurosurgery patients

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Hideichi; Kobayashi, Masahito [Mihara Memorial Hospital, Isesaki, Gunma (Japan); Sugishita, Morihiro; Onozuka, Satoshi; Kawase, Takeshi

    2001-03-01

    Assessment of language lateralization is crucial in patients considered for neurological surgery. The authors used functional MRI (fMRI) in conjunction with shiritori, a kind of word-generation task as paradigms, to determine language lateralization in the patients. We used a 1.5 Tesla magnetic resonance imaging devise with an echo-planar imaging sequence. Thirty-two patients undergoing neurological surgery would alternately rest and silently perform shiritori during fMRI acquisition. Language lateralization was determined in 29 out of 32 patients. Twenty-two patients were considered as left-hemisphere dominant and seven were right-hemisphere dominant. Brain activation was seen in the prefrontal area, premotor area, superior temporal gyrus and parietal lobe of the dominant hemisphere, which is consistent with the results in normal adults. Language lateralization was particularly useful in a case of meningioma in the left lateral ventricle and in a case of AVM in the left temporoparietal region. fMRI with shiritori tasks revealed right-hemisphere dominance in both cases, which was also confirmed by intracarotid amobarbital (Wada) testing. Both lesions were treated successfully without causing any further deficit to the patients' language function. These results suggest that fMRI with shiritori tasks can be used to assess language lateralization non-invasively, compared with the current techniques, such as intracarotid amobarbital testing and cortical electrostimulation mapping. Thus, fMRI with shiritori tasks has significant clinical potential as a presurgical evaluation tool. (author)

  6. Functional brain microstate predicts the outcome in a visuospatial working memory task.

    Science.gov (United States)

    Muthukrishnan, Suriya-Prakash; Ahuja, Navdeep; Mehta, Nalin; Sharma, Ratna

    2016-11-01

    Humans have limited capacity of processing just up to 4 integrated items of information in the working memory. Thus, it is inevitable to commit more errors when challenged with high memory loads. However, the neural mechanisms that determine the accuracy of response at high memory loads still remain unclear. High temporal resolution of Electroencephalography (EEG) technique makes it the best tool to resolve the temporal dynamics of brain networks. EEG-defined microstate is the quasi-stable scalp electrical potential topography that represents the momentary functional state of brain. Thus, it has been possible to assess the information processing currently performed by the brain using EEG microstate analysis. We hypothesize that the EEG microstate preceding the trial could determine its outcome in a visuospatial working memory (VSWM) task. Twenty-four healthy participants performed a high memory load VSWM task, while their brain activity was recorded using EEG. Four microstate maps were found to represent the functional brain state prior to the trials in the VSWM task. One pre-trial microstate map was found to determine the accuracy of subsequent behavioural response. The intracranial generators of the pre-trial microstate map that determined the response accuracy were localized to the visuospatial processing areas at bilateral occipital, right temporal and limbic cortices. Our results imply that the behavioural outcome in a VSWM task could be determined by the intensity of activation of memory representations in the visuospatial processing brain regions prior to the trial.

  7. Exercise mode and executive function in older adults: an ERP study of task-switching.

    Science.gov (United States)

    Dai, Chih-Ta; Chang, Yu-Kai; Huang, Chung-Ju; Hung, Tsung-Min

    2013-11-01

    The purpose of this study was to investigate the relationship between exercise mode and executive function and its effect on behavior and neuroelectric activity. Forty-eight older adults were classified into open-skill, closed-skill, and irregular exercise groups based on their experience of exercise participation. Executive function was measured via a task-switching paradigm, in which the behavioral indices and event-related potentials elicited by task-switching were assessed. The results revealed that the exercise groups, regardless of the exercise mode, exhibited faster reaction times in both global and local switches than the irregular exercise group, regardless of the within-task conditions. Similarly, larger P3 amplitudes were observed in both exercise groups compared to the irregular exercise group. Moreover, additional facilitation effects of open-skill exercises on global switch costs were observed, whereas no differences in local switch costs were found among the three groups. The results replicate previous studies that have reported generally improved executive function after participation in exercises; additionally, they extend the current knowledge by indicating that these cognitive improvements in specific aspects of executive function could also be obtained from open-skill exercises.

  8. Feasibility of the adaptive and automatic presentation of tasks (ADAPT system for rehabilitation of upper extremity function post-stroke

    Directory of Open Access Journals (Sweden)

    Choi Younggeun

    2011-08-01

    Full Text Available Abstract Background Current guidelines for rehabilitation of arm and hand function after stroke recommend that motor training focus on realistic tasks that require reaching and manipulation and engage the patient intensively, actively, and adaptively. Here, we investigated the feasibility of a novel robotic task-practice system, ADAPT, designed in accordance with such guidelines. At each trial, ADAPT selects a functional task according to a training schedule and with difficulty based on previous performance. Once the task is selected, the robot picks up and presents the corresponding tool, simulates the dynamics of the tasks, and the patient interacts with the tool to perform the task. Methods Five participants with chronic stroke with mild to moderate impairments (> 9 months post-stroke; Fugl-Meyer arm score 49.2 ± 5.6 practiced four functional tasks (selected out of six in a pre-test with ADAPT for about one and half hour and 144 trials in a pseudo-random schedule of 3-trial blocks per task. Results No adverse events occurred and ADAPT successfully presented the six functional tasks without human intervention for a total of 900 trials. Qualitative analysis of trajectories showed that ADAPT simulated the desired task dynamics adequately, and participants reported good, although not excellent, task fidelity. During training, the adaptive difficulty algorithm progressively increased task difficulty leading towards an optimal challenge point based on performance; difficulty was then continuously adjusted to keep performance around the challenge point. Furthermore, the time to complete all trained tasks decreased significantly from pretest to one-hour post-test. Finally, post-training questionnaires demonstrated positive patient acceptance of ADAPT. Conclusions ADAPT successfully provided adaptive progressive training for multiple functional tasks based on participant's performance. Our encouraging results establish the feasibility of ADAPT; its

  9. NASA's Functional Task Test: Providing Information for an Integrated Countermeasure System

    Science.gov (United States)

    Bloomberg, J. J.; Feiveson, A. H.; Laurie, S. S.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts, S. H.; Ploutz-Snyder, L. L.; Reschke, M. F.; Ryder, J. W.; Stenger, M. B.; Taylor, L. C.; Wood, S. J.

    2015-01-01

    Exposure to the microgravity conditions of spaceflight causes astronauts to experience alterations in multiple physiological systems. These physiological changes include sensorimotor disturbances, cardiovascular deconditioning, and loss of muscle mass and strength. Some or all of these changes might affect the ability of crewmembers to perform critical mission tasks immediately after landing on a planetary surface. The goals of the Functional Task Test (FTT) study were to determine the effects of spaceflight on functional tests that are representative of critical exploration mission tasks and to identify the key physiological factors that contribute to decrements in performance. The FTT was comprised of seven functional tests and a corresponding set of interdisciplinary physiological measures targeting the sensorimotor, cardiovascular and muscular changes associated with exposure to spaceflight. Both Shuttle and ISS crewmembers participated in this study. Additionally, we conducted a supporting study using the FTT protocol on subjects before and after 70 days of 6? head-down bed rest. The bed rest analog allowed us to investigate the impact of body unloading in isolation on both functional tasks and on the underlying physiological factors that lead to decrements in performance, and then to compare them with the results obtained in our spaceflight study. Spaceflight data were collected on three sessions before flight, on landing day (Shuttle only) and 1, 6 and 30 days after landing. Bed rest subjects were tested three times before bed rest and immediately after getting up from bed rest as well as 1, 6, and 12 days after reambulation. We have shown that for Shuttle, ISS and bed rest subjects, functional tasks requiring a greater demand for dynamic control of postural equilibrium (i.e. fall recovery, seat egress/obstacle avoidance during walking, object translation, jump down) showed the greatest decrement in performance. Functional tests with reduced requirements for

  10. Control of a Biped Robot by Total Rate of Angular Momentum Using the Task Function Approach

    Directory of Open Access Journals (Sweden)

    J. A. Rojas-Estrada

    2005-01-01

    Full Text Available In this work we address the control problem of biped robots by using the task function approach. A problem arrives when one of the feet is in contact with the ground, which presents imperfections. There is then the possibility that the biped robot undergoes a fall. It is difficult to track any trajectory due to the presence of unevenness on the ground. What we propose is to use the task function approach combined with the application of the total rate of angular momentum to obtain a control law for the ankle. By this technique, the tracking becomes more smooth and the balance is assured. The control law proposed allows the upper part of the robot to be controlled independently since only the ankle actuators are concerned. We enounce the formal problem and present some simulations with real parameters of a 21 degrees of freedom biped robot.

  11. Gain-of-function mutation in TASK-4 channels and severe cardiac conduction disorder.

    Science.gov (United States)

    Friedrich, Corinna; Rinné, Susanne; Zumhagen, Sven; Kiper, Aytug K; Silbernagel, Nicole; Netter, Michael F; Stallmeyer, Birgit; Schulze-Bahr, Eric; Decher, Niels

    2014-07-01

    Analyzing a patient with progressive and severe cardiac conduction disorder combined with idiopathic ventricular fibrillation (IVF), we identified a splice site mutation in the sodium channel gene SCN5A. Due to the severe phenotype, we performed whole-exome sequencing (WES) and identified an additional mutation in the KCNK17 gene encoding the K2P potassium channel TASK-4. The heterozygous change (c.262G>A) resulted in the p.Gly88Arg mutation in the first extracellular pore loop. Mutant TASK-4 channels generated threefold increased currents, while surface expression was unchanged, indicating enhanced conductivity. When co-expressed with wild-type channels, the gain-of-function by G88R was conferred in a dominant-active manner. We demonstrate that KCNK17 is strongly expressed in human Purkinje cells and that overexpression of G88R leads to a hyperpolarization and strong slowing of the upstroke velocity of spontaneously beating HL-1 cells. Thus, we propose that a gain-of-function by TASK-4 in the conduction system might aggravate slowed conductivity by the loss of sodium channel function. Moreover, WES supports a second hit-hypothesis in severe arrhythmia cases and identified KCNK17 as a novel arrhythmia gene.

  12. The functional connectivity of semantic task changes in the recovery from stroke aphasia

    Science.gov (United States)

    Lu, Jie; Wu, Xia; Yao, Li; Li, Kun-Cheng; Shu, Hua; Dong, Qi

    2007-03-01

    Little is known about the difference of functional connectivity of semantic task between the recovery aphasic patients and normal subject. In this paper, an fMRI experiment was performed in a patient with aphasia following a left-sided ischemic lesion and normal subject. Picture naming was used as semantic activation task in this study. We compared the preliminary functional connectivity results of the recovery aphasic patient with the normal subject. The fMRI data were separated by independent component analysis (ICA) into 90 components. According to our experience and other papers, we chose a region of interest (ROI) of semantic (x=-57, y=15, z=8, r=11mm). From the 90 components, we chose one component as the functional connectivity of the semantic ROI according to one criterion. The criterion is the mean value of the voxels in the ROI. So the component of the highest mean value of the ROI is the functional connectivity of the ROI. The voxel with its value higher than 2.4 was thought as activated (pstroke aphasic patient and normal subjects are different. The activated areas of the left inferior frontal gyrus and inferior/middle temporal gyrus are larger than the ones of normal. The activated area of the right inferior frontal gyrus is smaller than the ones of normal. The functional connectivity of stroke aphasic patient under semantic condition is different with the normal one. The focus of the stroke aphasic patient can affect the functional connectivity.

  13. Brain functional network changes following Prelimbic area inactivation in a spatial memory extinction task.

    Science.gov (United States)

    Méndez-Couz, Marta; Conejo, Nélida M; Vallejo, Guillermo; Arias, Jorge L

    2015-01-01

    Several studies suggest a prefrontal cortex involvement during the acquisition and consolidation of spatial memory, suggesting an active modulating role at late stages of acquisition processes. Recently, we have reported that the prelimbic and infralimbic areas of the prefrontal cortex, among other structures, are also specifically involved in the late phases of spatial memory extinction. This study aimed to evaluate whether the inactivation of the prelimbic area of the prefrontal cortex impaired spatial memory extinction. For this purpose, male Wistar rats were implanted bilaterally with cannulae into the prelimbic region of the prefrontal cortex. Animals were trained during 5 consecutive days in a hidden platform task and tested for reference spatial memory immediately after the last training session. One day after completing the training task, bilateral infusion of the GABAA receptor agonist Muscimol was performed before the extinction protocol was carried out. Additionally, cytochrome c oxidase histochemistry was applied to map the metabolic brain activity related to the spatial memory extinction under prelimbic cortex inactivation. Results show that animals acquired the reference memory task in the water maze, and the extinction task was successfully completed without significant impairment. However, analysis of the functional brain networks involved by cytochrome oxidase activity interregional correlations showed changes in brain networks between the group treated with Muscimol as compared to the saline-treated group, supporting the involvement of the mammillary bodies at a the late stage in the memory extinction process.

  14. [Effectiveness of an executive function task with a touch panel system for young children].

    Science.gov (United States)

    Sakata, Yoko; Moriguchi, Yusuke

    2016-06-01

    The Dimensional Change Card Sort (DCCS) task is a widely used measure for the development of executive function during early childhood. In this task, children are asked to sort cards according to one rule (e.g., color) during preswitch phases, after which they are asked to sort cards according to another rule (e.g.; shape) during the postswitch phases. A computer version of the DCCS was needed to standardize the test material, but a previous study showed that children showed more difficulty in a computer version with a mouse device than the standard card version. In this study, we assessed the effectiveness of a computer version with a touch panel and compared performance with the standard card version. Three- and 4-year-old children were given the card version and computer version of the DCCS tasks. The results revealed that children showed similar performance during the preswitch and postswitch phases both in the computer version and in the card version. The results suggest that both versions of the task assessed the same underlying cognitive processes.

  15. Functional Equivalence of Imagined vs. Real Performance of an Inhibitory Task: An EEG/ERP Study

    Science.gov (United States)

    Galdo-Alvarez, Santiago; Bonilla, Fidel M.; González-Villar, Alberto J.; Carrillo-de-la-Peña, María T.

    2016-01-01

    Early neuroimaging and electrophysiological studies suggested that motor imagery recruited a different network than motor execution. However, several studies have provided evidence for the involvement of the same circuits in motor imagery tasks, in the absence of overt responses. The present study aimed to test whether imagined performance of a stop-signal task produces a similar pattern of motor-related EEG activity than that observed during real performance. To this end, mu and beta event-related desynchronization (ERD) and the Lateralized Readiness Potential (LRP) were analyzed. The study also aimed to clarify the functional significance of the Stop-N2 and Stop-P3 event-related potential (ERPs) components, which were also obtained during both real and imagined performance. The results showed a common pattern of brain electrical activity, and with a similar time course, during covert performance and overt execution of the stop-signal task: presence of LRP and Stop-P3 in the imagined condition and identical LRP onset, and similar mu and beta ERD temporal windows for both conditions. These findings suggest that a similar inhibitory network may be activated during both overt and covert execution of the task. Therefore, motor imagery may be useful to improve inhibitory skills and to develop new communicating systems for Brain-Computer Interface (BCI) devices based on inhibitory signals. PMID:27695410

  16. Functional equivalence of imagined vs. real performance of an inhibitory task: an EEG/ERP study.

    Directory of Open Access Journals (Sweden)

    Santiago Galdo-Alvarez

    2016-09-01

    Full Text Available Early neuroimaging and electrophysiological studies suggested motor imagery recruited a different network than motor execution. However, several studies have provided evidence for the involvement of the same circuits in motor imagery tasks, in the absence of overt responses. The present study aimed to test whether imagined performance of a stop-signal task produces a similar pattern of motor-related EEG activity than that observed during real performance. To this end, mu and beta event-related desynchronization (ERD and the Lateralized Readiness Potential (LRP were analyzed. The study also aimed to clarify the functional significance of the Stop-N2 and Stop-P3 ERP components, which were also obtained during both real and imagined performance. The results showed a common pattern of brain electrical activity, and with a similar time course, during covert performance and overt execution of the stop-signal task: presence of LRP and Stop-P3 in the imagined condition and identical LRP onset, and similar mu and beta ERD temporal windows for both conditions. These findings suggest that a similar inhibitory network may be activated during both overt and covert execution of the task. Therefore, motor imagery may be useful to improve inhibitory skills and to develop new communicating systems for Brain Computer Interface (BCI devices based on inhibitory signals.

  17. TMS investigations into the task-dependent functional interplay between human posterior parietal and motor cortex.

    Science.gov (United States)

    Koch, Giacomo; Rothwell, John C

    2009-09-14

    Transcranial magnetic stimulation (TMS) can be used in two different ways to investigate the contribution of cortical areas involved in grasp/reach movements in humans. It can produce "virtual lesions" that interfere with activity in particular cortical areas at specific times during a task, or it can be used in a twin coil design to test the excitability of cortical projections to M1 at different times during a task. The former method has described how cortical structures such as the ventral premotor cortex (PMv), dorsal premotor cortex (PMd) and the anterior intraparietal sulcus (aIPS) are important for specific aspects of reaching, grasping and lifting objects. In the latter method, a conditioning stimulus (CS) is first used to activate putative pathways to the motor cortex from, for example, posterior parietal cortex (PPC) or PMd, while a second, test stimulus (TS), delivered over the primary motor cortex a few ms later probes any changes in excitability that are produced by the input. Thus changes in the effectiveness of the conditioning pulse give an indication of how the excitability of the connection changes over time and during a specific task. Here we review studies describing the time course of operation of parallel intracortical circuits and cortico-cortical connections between the PMd, PMv, PPC and M1, thus demonstrating that functional interplay between these areas and the primary motor cortices is not fixed, but can change in a highly task-, condition- and time-dependent manner.

  18. Quantification of flash flood economic risk using ultra-detailed stage-damage functions and 2-D hydraulic models

    Science.gov (United States)

    Garrote, J.; Alvarenga, F. M.; Díez-Herrero, A.

    2016-10-01

    The village of Pajares de Pedraza (Segovia, Spain) is located in the floodplain of the Cega River, a left bank tributary of the Douro River. Repeated flash flood events occur in this small village because of its upstream catchment area, mountainous character and impermeable lithology, which reduce concentration time to just a few hours. River overbank flow has frequently caused flooding and property damage to homes and rural properties, most notably in 1927, 1991, 1996, 2001, 2013 and 2014. Consequently, a detailed analysis was carried out to quantify the economic risk of flash floods in peri-urban and rural areas. Magnitudes and exceedance probabilities were obtained from a flood frequency analysis of maximum discharges. To determine the extent and characteristics of the flooded area, we performed 2D hydraulic modeling (Iber 2.0 software) based on LIDAR (1 m) topography and considering three different scenarios associated with the initial construction (1997) and subsequent extension (2013) of a linear defense structure (rockfill dike or levee) to protect the population. Specific stage-damage functions were expressly developed using in situ data collection for exposed elements, with special emphasis on urban-type categories. The average number of elements and their unit value were established. The relationship between water depth and the height at which electric outlets, furniture, household goods, etc. were located was analyzed; due to its effect on the form of the function. Other nonspecific magnitude-damage functions were used in order to compare both economic estimates. The results indicate that the use of non-specific magnitude-damage functions leads to a significant overestimation of economic losses, partly linked to the use of general economic cost data. Furthermore, a detailed classification and financial assessment of exposed assets is the most important step to ensure a correct estimate of financial losses. In both cases, this should include a

  19. The relation between structural and functional connectivity depends on age and on task goals

    Directory of Open Access Journals (Sweden)

    Jaclyn Hennessey Ford

    2014-05-01

    Full Text Available The last decade has seen an increase in neuroimaging studies examining structural (i.e., structural integrity of white matter tracts and functional connectivity (e.g., correlations in neural activity throughout the brain. Although structural and functional connectivity changes have often been measured independently, examining the relation between these two measures is critical to understanding the specific function of neural networks and the ways they may differ across tasks and individuals. The current study addressed this question by examining the effect of age (treated as a continuous variable and emotional valence on the relation between functional and structural connectivity. As prior studies have suggested that prefrontal regions may guide and regulate emotional memory search via functional connections with the amygdala, the current analysis focused on functional connectivity between the left amygdala and the left prefrontal cortex, and structural integrity of the uncinate fasciculus, a white matter tract connecting prefrontal and temporal regions.Participants took part in a scanned retrieval task in which they recalled positive, negative, and neutral images associated with neutral titles. Aging was associated with a significant increase in the relation between measures of structural integrity (specifically, fractional anisotropy, or FA along the uncinate fasciculus and functional connectivity between the left ventral prefrontal cortex and amygdala during positive event retrieval, but not negative or neutral retrieval. Notably, during negative event retrieval, age was linked to stronger structure-function relations between the amygdala and the dorsal anterior cingulate cortex, such that increased structural integrity predicted strong negative functional connectivity in older adults only. These findings are consistent with theories that older adults may engage regulatory strategies if they have the structural pathways to allow them to do so.

  20. Entorhinal cortex structure and functional MRI response during an associative verbal memory task.

    Science.gov (United States)

    Braskie, Meredith N; Small, Gary W; Bookheimer, Susan Y

    2009-12-01

    Entorhinal cortex (ERC) volume in adults with mild cognitive impairment has been shown to predict prodromal Alzheimer's disease (AD). Likewise, neuronal loss in ERC has been associated with AD, but not with normal aging. Because ERC is part of a major pathway modulating input to the hippocampus, structural changes there may result in changes to cognitive performance and functional brain activity during memory tasks. In 32 cognitively intact older adults, we examined the relationship between left ERC thickness and functional magnetic resonance imaging (fMRI) activity during an associative verbal memory task. This task has been shown previously to activate regions that are sensitive to aging and AD risk. ERC was manually defined on native space, high resolution, oblique coronal MRI scans. Subjects having thicker left ERC showed greater activation in anterior cingulate and medial frontal regions during memory retrieval, but not encoding. This result was independent of hippocampal volume. Anterior cingulate cortex is directly connected to ERC, and is, along with medial frontal cortex, implicated in error detection, which is impaired in AD. Our results suggest that in healthy older adults, processes that engage frontal regions during memory retrieval are related to ERC structure.

  1. The relation of structural integrity and task-related functional connectivity in the aging brain.

    Science.gov (United States)

    Burianová, Hana; Marstaller, Lars; Choupan, Jeiran; Sepehrband, Farshid; Ziaei, Maryam; Reutens, David

    2015-10-01

    The relations among structural integrity, functional connectivity (FC), and cognitive performance in the aging brain are still understudied. Here, we used multimodal and multivariate approaches to specifically examine age-related changes in task-related FC, gray-matter volumetrics, white-matter integrity, and performance. Our results are two-fold, showing (i) age-related differences in FC of the working memory network and (ii) age-related recruitment of a compensatory network associated with better accuracy on the task. Increased connectivity in the compensatory network correlates positively with preserved white-matter integrity in bilateral frontoparietal tracks and with larger gray-matter volume of right inferior parietal lobule. These findings demonstrate the importance of structural integrity and FC in working memory performance associated with healthy aging.

  2. Understanding the Effects of Long-duration Space Flight on Astronant Functional Task Performance

    Science.gov (United States)

    Bloomberg, Jacob J.; Batson, Crystal D.; Buxton, Roxanne E.; Feiveson, Al H.; Kofman, Igor S.; Lee, Stuart M. C.; Miller, Chris A.; Mulavara, Ajitkumar P.; Peters, Brian T.; Phillips, Tiffany; hide

    2014-01-01

    Space flight is known to cause alterations in multiple physiological systems including changes in sensorimotor, cardiovascular, and neuromuscular systems. These physiological changes cause balance, gait and visual disturbances, cardiovascular deconditioning, and loss of muscle mass and strength. These changes may affect a crewmember's ability to perform critical mission tasks immediately after landing on a planetary surface. To understand how changes in physiological function affect functional performance, an interdisciplinary pre- and postflight testing regimen, Functional Task Test (FTT), was developed to systematically evaluate both astronaut functional performance and related physiological changes. Ultimately this information will be used to assess performance risks and inform the design of countermeasures for exploration class missions. We are currently conducting the FTT study on International Space Station (ISS) crewmembers before and after 6-month expeditions. Additionally, in a corresponding study we are using the FTT protocol on subjects before and after 70 days of 6deg head-down bed-rest as an analog for space flight. Bed-rest provides the opportunity for us to investigate the role of prolonged axial body unloading in isolation from the other physiological effects produced by exposure to the microgravity environment of space flight. Therefore, the bed rest analog allows us to investigate the impact of body unloading on both functional tasks and on the underlying physiological factors that lead to decrement in performance and then compare them with the results obtained in our space flight study. Functional tests included ladder climbing, hatch opening, jump down, manual manipulation of objects and tool use, seat egress and obstacle avoidance, recovery from a fall and object translation tasks. Physiological measures included assessments of postural and gait control, dynamic visual acuity, fine motor control, plasma volume, heart rate, blood pressure

  3. Author Details

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    Journal Home > Advanced Search > Author Details ... Intra‑Operative Airway Management in Patients with Maxillofacial Trauma having Reduction and ... Clinical Parameters and Challenges of Managing Cervicofacial Necrotizing Fasciitis in a ...

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    Journal Home > Advanced Search > Author Details. Log in or ... Difficult airway management in a patient with giant malignant goitre scheduled for thyroidectomy - case report ... Airway Management Dilemma in a Patient with Maxillofacial Injury

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    Journal Home > Advanced Search > Author Details ... Sequencing for Batch Production in a Group Flowline Machine Shop ... Sampling Plans for Monitoring Quality Control Process at a Plastic Manufacturing Firm in Nigeria: A Case Study

  6. Cognitive deterioration and functional compensation in ALS measured with fMRI using an inhibitory task.

    Science.gov (United States)

    Witiuk, Kelsey; Fernandez-Ruiz, Juan; McKee, Ryan; Alahyane, Nadia; Coe, Brian C; Melanson, Michel; Munoz, Douglas P

    2014-10-22

    Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of upper and lower motor neurons, resulting in progressive weakness and muscle atrophy. Recent studies suggest that nondemented ALS patients can show selective cognitive impairments, predominantly executive dysfunction, but little is known about the neural basis of these impairments. Oculomotor studies in ALS have described deficits in antisaccade execution, which requires the implementation of a task set that includes inhibition of automatic responses followed by generation of a voluntary action. It has been suggested that the dorsolateral prefrontal cortex (DLPFC) contributes in this process. Thus, we investigated whether deterioration of executive functions in ALS patients, such as the ability to implement flexible behavior during the antisaccade task, is related to DLPFC dysfunction. While undergoing an fMRI scan, 12 ALS patients and 12 age-matched controls performed an antisaccade task with concurrent eye tracking. We hypothesized that DLPFC deficits would appear during the antisaccade preparation stage, when the task set is being established. ALS patients made more antisaccade direction errors and showed significant reductions in DLPFC activation. In contrast, regions, such as supplementary eye fields and frontal eye fields, showed increased activation that was anticorrelated with the number of errors. The ALS group also showed reduced saccadic latencies that correlated with increased activation across the oculomotor saccade system. These findings suggest that ALS results in deficits in the inhibition of automatic responses that are related to impaired DLPFC activation. However, they also suggest that ALS patients undergo functional changes that partially compensate the neurological impairment. Copyright © 2014 the authors 0270-6474/14/3414260-12$15.00/0.

  7. Functional brain connectivity and cognition: effects of adult age and task demands.

    Science.gov (United States)

    Chou, Ying-Hui; Chen, Nan-Kuei; Madden, David J

    2013-08-01

    Previous neuroimaging research has documented that patterns of intrinsic (resting state) functional connectivity (FC) among brain regions covary with individual measures of cognitive performance. Here, we examined the relation between intrinsic FC and a reaction time (RT) measure of performance, as a function of age group and task demands. We obtained filtered, event-related functional magnetic resonance imaging data, and RT measures of visual search performance, from 21 younger adults (19-29 years old) and 21 healthy, older adults (60-87 years old). Age-related decline occurred in the connectivity strength in multiple brain regions, consistent with previous findings. Among 8 pairs of regions, across somatomotor, orbitofrontal, and subcortical networks, increasing FC was associated with faster responding (lower RT). Relative to younger adults, older adults exhibited a lower strength of this RT-connectivity relation and greater disruption of this relation by a salient but irrelevant display item (color singleton distractor). Age-related differences in the covariation of intrinsic FC and cognitive performance vary as a function of task demands.

  8. Functional connectivity in task-negative network of the Deaf: effects of sign language experience.

    Science.gov (United States)

    Malaia, Evie; Talavage, Thomas M; Wilbur, Ronnie B

    2014-01-01

    Prior studies investigating cortical processing in Deaf signers suggest that life-long experience with sign language and/or auditory deprivation may alter the brain's anatomical structure and the function of brain regions typically recruited for auditory processing (Emmorey et al., 2010; Pénicaud et al., 2013 inter alia). We report the first investigation of the task-negative network in Deaf signers and its functional connectivity-the temporal correlations among spatially remote neurophysiological events. We show that Deaf signers manifest increased functional connectivity between posterior cingulate/precuneus and left medial temporal gyrus (MTG), but also inferior parietal lobe and medial temporal gyrus in the right hemisphere- areas that have been found to show functional recruitment specifically during sign language processing. These findings suggest that the organization of the brain at the level of inter-network connectivity is likely affected by experience with processing visual language, although sensory deprivation could be another source of the difference. We hypothesize that connectivity alterations in the task negative network reflect predictive/automatized processing of the visual signal.

  9. Functional connectivity in task-negative network of the Deaf: effects of sign language experience

    Directory of Open Access Journals (Sweden)

    Evie Malaia

    2014-06-01

    Full Text Available Prior studies investigating cortical processing in Deaf signers suggest that life-long experience with sign language and/or auditory deprivation may alter the brain’s anatomical structure and the function of brain regions typically recruited for auditory processing (Emmorey et al., 2010; Pénicaud et al., 2013 inter alia. We report the first investigation of the task-negative network in Deaf signers and its functional connectivity—the temporal correlations among spatially remote neurophysiological events. We show that Deaf signers manifest increased functional connectivity between posterior cingulate/precuneus and left medial temporal gyrus (MTG, but also inferior parietal lobe and medial temporal gyrus in the right hemisphere- areas that have been found to show functional recruitment specifically during sign language processing. These findings suggest that the organization of the brain at the level of inter-network connectivity is likely affected by experience with processing visual language, although sensory deprivation could be another source of the difference. We hypothesize that connectivity alterations in the task negative network reflect predictive/automatized processing of the visual signal.

  10. Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

    Science.gov (United States)

    Banducci, Sarah E.; Daugherty, Ana M.; Fanning, Jason; Awick, Elizabeth A.; Porter, Gwenndolyn C.; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F.; McAuley, Edward

    2017-01-01

    Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial). PMID:28255557

  11. Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults.

    Science.gov (United States)

    Ehlers, Diane K; Banducci, Sarah E; Daugherty, Ana M; Fanning, Jason; Awick, Elizabeth A; Porter, Gwenndolyn C; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F; McAuley, Edward

    2017-01-01

    Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60-79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial).

  12. Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

    Directory of Open Access Journals (Sweden)

    Diane K. Ehlers

    2017-01-01

    Full Text Available Objectives. Despite evidence of self-efficacy and physical function’s influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults’ street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials and conversed on a cell phone (dual-task trials. Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults’ performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial.

  13. Effects of dual-task training on balance and executive functions in Parkinson's disease: A pilot study.

    Science.gov (United States)

    Fernandes, Ângela; Rocha, Nuno; Santos, Rubim; Tavares, João Manuel R S

    2015-01-01

    The aim of this study was to analyze the efficacy of cognitive-motor dual-task training compared with single-task training on balance and executive functions in individuals with Parkinson's disease. Fifteen subjects, aged between 39 and 75 years old, were randomly assigned to the dual-task training group (n = 8) and single-task training group (n = 7). The training was run twice a week for 6 weeks. The single-task group received balance training and the dual-task group performed cognitive tasks simultaneously with the balance training. There were no significant differences between the two groups at baseline. After the intervention, the results for mediolateral sway with eyes closed were significantly better for the dual-task group and anteroposterior sway with eyes closed was significantly better for the single-task group. The results suggest superior outcomes for the dual-task training compared to the single-task training for static postural control, except in anteroposterior sway with eyes closed.

  14. Graphical Tasks to Measure Upper Limb Function in Patients With Parkinson's Disease: Validity and Response to Dopaminergic Medication.

    Science.gov (United States)

    Smits, Esther J; Tolonen, Antti J; Cluitmans, Luc; van Gils, Mark; Zietsma, Rutger C; Borgemeester, Robbert W K; van Laar, Teus; Maurits, Natasha M

    2017-01-01

    The most widely used method to assess motor functioning in Parkinson's disease (PD) patients is the unified Parkinson's disease rating scale-III (UPDRS-III). The UPDRS-III has limited ability to detect subtle changes in motor symptoms. Alternatively, graphical tasks can be used to provide objective measures of upper limb motor dysfunction. This study investigated the validity of such graphical tasks to assess upper limb function in PD patients and their ability to detect subtle changes in performance. Fourteen PD patients performed graphical tasks before and after taking dopaminergic medication. Graphical tasks included figure tracing, writing, and a modified Fitts' task. The Purdue pegboard test was performed to validate these graphical tasks. Movement time (MT), writing size, and the presence of tremor were assessed. MT on the graphical tasks correlated significantly with performance on the Purdue pegboard test (Spearman's ρ > 0.65; p < 0.05). MT decreased significantly after the intake of dopaminergic medication. Tremor power decreased after taking dopaminergic medication in most PD patients who suffered from tremor. Writing size did not correlate with performance on the Purdue pegboard test, nor did it change after taking medication. Our set of graphical tasks is valid to assess upper limb function in PD patients. MT proved to be the most useful measure for this purpose. The response on dopaminergic medication was optimally reflected by an improved MT on the graphical tasks in combination with a decreased tremor power, whereas writing size did not respond to dopaminergic treatment.

  15. A New Semantic List Learning Task to Probe Functioning of the Papez Circuit

    Science.gov (United States)

    Schallmo, Michael-Paul; Kassel, Michelle T.; Weisenbach, Sara L.; Walker, Sara J.; Guidotti-Breting, Leslie M.; Rao, Julia A.; Hazlett, Kathleen E.; Considine, Ciaran M.; Sethi, Gurpriya; Vats, Naalti; Pecina, Marta; Welsh, Robert C.; Starkman, Monica N.; Giordani, Bruno; Langenecker, Scott A.

    2016-01-01

    Introduction List learning tasks are powerful clinical tools for studying memory, yet have been relatively underutilized within the functional imaging literature. This limits understanding of regions such as the Papez circuit which support memory performance in healthy, non-demented adults. Method The current study characterized list learning performance in 40 adults who completed a Semantic List Learning Task (SLLT) with a Brown-Peterson manipulation during functional MRI (fMRI). Cued recall with semantic cues, and recognition memory were assessed after imaging. Internal reliability and convergent and discriminant validity were evaluated. Results Subjects averaged 38% accuracy in recall (62% for recognition), with primacy but no recency effects observed. Validity and reliability were demonstrated by showing that the SLLT was correlated with the California Verbal Learning test (CVLT), but not with executive functioning tests, and high intraclass correlation coefficient across lists for recall (.91). fMRI measurements during Encoding (vs. Silent Rehearsal) revealed significant activation in bilateral hippocampus, parahippocampus, and bilateral anterior and posterior cingulate cortex. Post-hoc analyses showed increased activation in anterior and middle hippocampus, subgenual cingulate, and mammillary bodies specific to Encoding. In addition, increasing age was positively associated with increased activation in a diffuse network, particularly frontal cortex and specific Papez regions for correctly recalled words. Gender differences were specific to left inferior and superior frontal cortex. Conclusions This is a clinically relevant list learning task that can be used in studies of groups for which the Papez circuit is damaged or disrupted, in mixed or crossover studies at imaging and clinical sites. PMID:26313512

  16. Development of an Objective Space Suit Mobility Performance Metric Using Metabolic Cost and Functional Tasks

    Science.gov (United States)

    McFarland, Shane M.; Norcross, Jason

    2016-01-01

    Existing methods for evaluating EVA suit performance and mobility have historically concentrated on isolated joint range of motion and torque. However, these techniques do little to evaluate how well a suited crewmember can actually perform during an EVA. An alternative method of characterizing suited mobility through measurement of metabolic cost to the wearer has been evaluated at Johnson Space Center over the past several years. The most recent study involved six test subjects completing multiple trials of various functional tasks in each of three different space suits; the results indicated it was often possible to discern between different suit designs on the basis of metabolic cost alone. However, other variables may have an effect on real-world suited performance; namely, completion time of the task, the gravity field in which the task is completed, etc. While previous results have analyzed completion time, metabolic cost, and metabolic cost normalized to system mass individually, it is desirable to develop a single metric comprising these (and potentially other) performance metrics. This paper outlines the background upon which this single-score metric is determined to be feasible, and initial efforts to develop such a metric. Forward work includes variable coefficient determination and verification of the metric through repeated testing.

  17. Iowa Gambling Task Performance and Executive Function Predict Low-income Urban Preadolescents’ Risky Behaviors

    Science.gov (United States)

    Ursache, Alexandra; Raver, C. Cybele

    2015-01-01

    This study examines preadolescents’ reports of risk-taking as predicted by two different, but related inhibitory control systems involving sensitivity to reward and loss on the one hand, and higher order processing in the context of cognitive conflict, known as executive functioning (EF), on the other. Importantly, this study examines these processes with a sample of inner-city, low-income preadolescents and as such examines the ways in which these processes may be related to risky behaviors as a function of children's levels of both concurrent and chronic exposure to household poverty. As part of a larger longitudinal study, 382 children (ages 9 -11) provided a self-report of risky behaviors and participated in the Iowa Gambling task, assessing bias for infrequent loss (preference for infrequent, high magnitude versus frequent, low magnitude loss) and the Hearts and Flowers task assessing executive functioning. Results demonstrated that a higher bias for infrequent loss was associated with higher risky behaviors for children who demonstrated lower EF. Furthermore, bias for infrequent loss was most strongly associated with higher risk-taking for children facing highest levels of poverty. Implications for early identification and prevention of risk-taking in inner-city preadolescents are discussed. PMID:26412918

  18. Iowa Gambling Task Performance and Executive Function Predict Low-income Urban Preadolescents' Risky Behaviors.

    Science.gov (United States)

    Ursache, Alexandra; Raver, C Cybele

    2015-06-01

    This study examines preadolescents' reports of risk-taking as predicted by two different, but related inhibitory control systems involving sensitivity to reward and loss on the one hand, and higher order processing in the context of cognitive conflict, known as executive functioning (EF), on the other. Importantly, this study examines these processes with a sample of inner-city, low-income preadolescents and as such examines the ways in which these processes may be related to risky behaviors as a function of children's levels of both concurrent and chronic exposure to household poverty. As part of a larger longitudinal study, 382 children (ages 9 -11) provided a self-report of risky behaviors and participated in the Iowa Gambling task, assessing bias for infrequent loss (preference for infrequent, high magnitude versus frequent, low magnitude loss) and the Hearts and Flowers task assessing executive functioning. Results demonstrated that a higher bias for infrequent loss was associated with higher risky behaviors for children who demonstrated lower EF. Furthermore, bias for infrequent loss was most strongly associated with higher risk-taking for children facing highest levels of poverty. Implications for early identification and prevention of risk-taking in inner-city preadolescents are discussed.

  19. Cognitive impairment after traumatic brain injury: a functional magnetic resonance imaging study using the Stroop task

    Energy Technology Data Exchange (ETDEWEB)

    Soeda, Akio; Iwama, Toru [Gifu University School of Medicine, Department of Neurosurgery, Gifu City (Japan); Nakashima, Toshihiko; Okumura, Ayumi; Shinoda, Jun [Kizawa Memorial Hospital, Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Department of Neurosurgery, Minokamo (Japan); Kuwata, Kazuo [Gifu University School of Medicine, Department of Biochemistry and Biophysics, Gifu (Japan)

    2005-07-01

    The anterior cingulate cortex (ACC) plays a key role in cognition, motor function, and emotion processing. However, little is known about how traumatic brain injury (TBI) affects the ACC system. Our purpose was to compare, by functional magnetic resonance imaging (fMRI) studies, the patterns of cortical activation in patients with cognitive impairment after TBI and those of normal subjects. Cortical activation maps of 11 right-handed healthy control subjects and five TBI patients with cognitive impairment were recorded in response to a Stroop task during a block-designed fMRI experiment. Statistical parametric mapping (SPM99) was used for individual subjects and group analysis. In TBI patients and controls, cortical activation, found in similar regions of the frontal, occipital, and parietal lobes, resembled patterns of activation documented in previous neuroimaging studies of the Stroop task in healthy controls. However, the TBI patients showed a relative decrease in ACC activity compared with the controls. Cognitive impairment in TBI patients seems to be associated with alterations in functional cerebral activity, especially less activation of the ACC. These changes are probably the result of destruction of neural networks after diffuse axonal injury and may reflect cortical disinhibition attributable to disconnection or compensation for an inefficient cognitive process. (orig.)

  20. Neural correlate of vernier acuity tasks assessed by functional MRI (FMRI).

    Science.gov (United States)

    Sheth, Kevin N; Walker, B Michael; Modestino, Edward J; Miki, Atsushi; Terhune, Kyla P; Francis, Ellie L; Haselgrove, John C; Liu, Grant T

    2007-01-01

    Vernier acuity refers to the ability to discern a small offset within a line. However, while Vernier acuity has been extensively studied psychophysically, its neural correlates are uncertain. Based upon previous psychophysical and electrophysiologic data, we hypothesized that extrastriate areas of the brain would be involved in Vernier acuity tasks, so we designed event-related functional MRI (fMRI) paradigms to identify cortical regions of the brain involved in this behavior. Normal subjects identified suprathreshold and subthreshold Vernier offsets. The results suggest a cortical network including frontal, parietal, occipital, and cerebellar regions subserves the observation, processing, interpretation, and acknowledgment of briefly presented Vernier offsets.

  1. Performance on a computerized shopping task significantly predicts real world functioning in persons diagnosed with bipolar disorder.

    Science.gov (United States)

    Laloyaux, Julien; Pellegrini, Nadia; Mourad, Haitham; Bertrand, Hervé; Domken, Marc-André; Van der Linden, Martial; Larøi, Frank

    2013-12-15

    Persons diagnosed with bipolar disorder often suffer from cognitive impairments. However, little is known concerning how these cognitive deficits impact their real world functioning. We developed a computerized real-life activity task, where participants are required to shop for a list of grocery store items. Twenty one individuals diagnosed with bipolar disorder and 21 matched healthy controls were administered the computerized shopping task. Moreover, the patient group was assessed with a battery of cognitive tests and clinical scales. Performance on the shopping task significantly differentiated patients and healthy controls for two variables: Total time to complete the shopping task and Mean time spent to consult the shopping list. Moreover, in the patient group, performance on these variables from the shopping task correlated significantly with cognitive functioning (i.e. processing speed, verbal episodic memory, planning, cognitive flexibility, and inhibition) and with clinical variables including duration of illness and real world functioning. Finally, variables from the shopping task were found to significantly explain 41% of real world functioning of patients diagnosed with bipolar disorder. These findings suggest that the shopping task provides a good indication of real world functioning and cognitive functioning of persons diagnosed with bipolar disorder. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. Trial-dependent psychometric functions accounting for perceptual learning in 2-AFC discrimination tasks.

    Science.gov (United States)

    Kattner, Florian; Cochrane, Aaron; Green, C Shawn

    2017-09-01

    The majority of theoretical models of learning consider learning to be a continuous function of experience. However, most perceptual learning studies use thresholds estimated by fitting psychometric functions to independent blocks, sometimes then fitting a parametric function to these block-wise estimated thresholds. Critically, such approaches tend to violate the basic principle that learning is continuous through time (e.g., by aggregating trials into large "blocks" for analysis that each assume stationarity, then fitting learning functions to these aggregated blocks). To address this discrepancy between base theory and analysis practice, here we instead propose fitting a parametric function to thresholds from each individual trial. In particular, we implemented a dynamic psychometric function whose parameters were allowed to change continuously with each trial, thus parameterizing nonstationarity. We fit the resulting continuous time parametric model to data from two different perceptual learning tasks. In nearly every case, the quality of the fits derived from the continuous time parametric model outperformed the fits derived from a nonparametric approach wherein separate psychometric functions were fit to blocks of trials. Because such a continuous trial-dependent model of perceptual learning also offers a number of additional advantages (e.g., the ability to extrapolate beyond the observed data; the ability to estimate performance on individual critical trials), we suggest that this technique would be a useful addition to each psychophysicist's analysis toolkit.

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

    Science.gov (United States)

    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…

  4. Task engagement in young adults with high-functioning autism spectrum disorders: Generalization effects of behavioral skills training

    NARCIS (Netherlands)

    Palmen, A.M.J.W.; Didden, H.C.M.

    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.

  5. Predictions of Actions and Their Justifications in False-Belief Tasks: The Role of Executive Function

    Directory of Open Access Journals (Sweden)

    Putko Adam

    2014-12-01

    Full Text Available The main objective of this study was to examine whether children’s ability to justify their action predictions in terms of mental states is related, in a similar way as the ability to predict actions, to such aspects of executive function (EF as executive control and working memory. An additional objective was to check whether the frequency of different types of justifications made by children in false-belief tasks is associated with aforementioned aspects of EF, as well as language. The study included 59 children aged 3-4 years. The ability to predict actions and to justify these predictions was measured with false-belief tasks. Luria’s hand-game was used to assess executive control, and the Counting and Labelling dual-task was used to assess working memory capacity. Language development was controlled using an embedded syntax test. It was found that executive control was a significant predictor of the children’s ability to justify their action predictions in terms of mental states, even when age and language were taken into account. Results also indicated a relationship between the type of justification in the false-belief task and language development. With the development of language children gradually cease to justify their action predictions in terms of current location, and they tend to construct irrelevant justifications before they begin to refer to beliefs. Data suggest that executive control, in contrast to language, is a factor which affects the development of the children’s ability to justify their action predictions only in its later phase, during a shift from irrelevant to correct justifications.

  6. The detailed assessment of left and right ventricular functions by tissue Doppler imaging in patients with familial Mediterranean fever.

    Science.gov (United States)

    Tavil, Yusuf; Ureten, Kemal; Oztürk, Mehmet Akif; Sen, Nihat; Kaya, Mehmet Güngör; Cemri, Mustafa; Cengel, Atiye

    2008-02-01

    In the contrary to other rheumatologic disorders, there have been limited numbers of studies investigating the cardiac involvement in patients with familial Mediterranean fever (FMF), although the disease may carry a potential for cardiovascular disorders because of sustained inflammation during its course. In the present study, we used high usefulness tissue Doppler echocardiography for detailed analysis of cardiac changes in FMF patients. The study population included 30 patients with FMF (11 men, 19 women; mean age, 35 +/- 7 years, mean disease duration, 15.4 +/- 7.6 years) and 30 healthy subjects as controls (12 men, 18 women; mean age, 33 +/- 7 years). The diagnosis of FMF was established according to the Tell-Hashomer criteria. Left and right ventricular functions were measured using echocardiography comprising standard two-dimensional, M-mode, and conventional Doppler as well as tissue Doppler imaging. The conventional echocardiographic paratemeters were similar apart from left ventricular relaxation time was longer (107 +/- 25 vs 85 +/- 10 ms, p < 0.001, respectively) in patients with FMF. According to the tissue Doppler measurements, while systolic velocities of both ventricles were not different, diastolic filling velocities of left ventricle including E'(m) (12.6 +/- 3.4 vs 14.7 +/- 3.3 cm/s, p = 0.04), A'(m) (10.1 +/- 2.6 vs 8.6 +/- 2.0 cm/s, p = 0.015), and E'(m)/ A'(m) (1.24 +/- 0.4 vs 1.71 +/- 0.5 cm/s, p = 0.012) values were statistically different between the groups. Left ventricular myocardial performance indices and right ventricular diastolic functions were found similar between two groups. In addition, there were no significant correlations between the disease duration, clinical features, and echocardiographic parameters. In conclusion, we have demonstrated that although systolic functions were comparable in the patients and controls, left ventricular diastolic function indices were impaired in FMF patients by using tissue Doppler analysis.

  7. Functional mapping of language networks in the normal brain using a word-association task

    Directory of Open Access Journals (Sweden)

    Ghosh Shantanu

    2010-01-01

    Full Text Available Background: Language functions are known to be affected in diverse neurological conditions, including ischemic stroke, traumatic brain injury, and brain tumors. Because language networks are extensive, interpretation of functional data depends on the task completed during evaluation. Aim: The aim was to map the hemodynamic consequences of word association using functional magnetic resonance imaging (fMRI in normal human subjects. Materials and Methods: Ten healthy subjects underwent fMRI scanning with a postlexical access semantic association task vs lexical processing task. The fMRI protocol involved a T2FNx01-weighted gradient-echo echo-planar imaging (GE-EPI sequence (TR 4523 ms, TE 64 ms, flip angle 90º with alternate baseline and activation blocks. A total of 78 scans were taken (interscan interval = 3 s with a total imaging time of 587 s. Functional data were processed in Statistical Parametric Mapping software (SPM2 with 8-mm Gaussian kernel by convolving the blood oxygenation level-dependent (BOLD signal with an hemodynamic response function estimated by general linear method to generate SPM{t} and SPM{F} maps. Results: Single subject analysis of the functional data (FWE-corrected, P≤0.001 revealed extensive activation in the frontal lobes, with overlaps among middle frontal gyrus (MFG, superior, and inferior frontal gyri. BOLD activity was also found in the medial frontal gyrus, middle occipital gyrus (MOG, anterior fusiform gyrus, superior and inferior parietal lobules, and to a smaller extent, the thalamus and right anterior cerebellum. Group analysis (FWE-corrected, P≤0.001 revealed neural recruitment of bilateral lingual gyri, left MFG, bilateral MOG, left superior occipital gyrus, left fusiform gyrus, bilateral thalami, and right cerebellar areas. Conclusions: Group data analysis revealed a cerebellar-occipital-fusiform-thalamic network centered around bilateral lingual gyri for word association, thereby indicating how these

  8. Aging effects of regional activation in a spatial task A functional magnetic resonance imaging study

    Institute of Scientific and Technical Information of China (English)

    Jong-Rak Park; Dae-Woon Lim; Mi-Hyun Choi; Su-Jeong Lee; Jin-Seung Choi; Hyung-Sik Kim; Jeong-Han Yi; Gye-Rae Tack; Soon-Cheol Chung

    2009-01-01

    BACKGROUND: An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging (fMRI). However, little is known about the aging effects in diverse cognitive abilities, such as spatial learning and reasoning. OBJECTIVE: To investigate the effect of aging on spatial cognitive performance and regional brain activation based on fMRI. DESIGN, TIME, AND SETTING: A block design for fMRI observation. This study was performed at the fMRI Laboratory, Brain Science Research Center, Korea Advanced Institute of Science and Technology from March 2006 to May 2009.PARTICIPANTS: Eight right-handed, male, college students in their 20s (mean age 21.5 years) and six right-handed, male, adults in their 40s (mean age 45.7 years), who graduated from college, participated in the study. All subjects were healthy and had no prior history of psychiatric or neurological disorders. METHODS: A spatial task was presented while brain images were acquired using a 3T fMRI system (ISOL Technology, Korea). The spatial tasks involved selecting a shape that corresponded to a given figure using four examples, as well as selecting a development figure of a diagram. MAIN OUTCOME MEASURES: The accuracy rate (number of correct answers/total number of items×100%) of spatial tasks was calculated. Using the subtraction procedure, the activated areas in the brain during spatial tasks were color-coded by T-score. The double subtraction method was used to analyze the effect of aging between the two age groups (20s versus 40s). RESULTS: The cerebellum, occipital lobe, parietal lobe, and frontal lobe were similarly activated in the two age groups. Increased brain activations, however, were observed in bilateral parietal and superior frontal lobes of the younger group. More activation was observed in bilateral middle frontal and right inferior frontal lobes in the older group. Compared with the older group, the

  9. Complex network analysis of brain functional connectivity under a multi-step cognitive task

    Science.gov (United States)

    Cai, Shi-Min; Chen, Wei; Liu, Dong-Bai; Tang, Ming; Chen, Xun

    2017-01-01

    Functional brain network has been widely studied to understand the relationship between brain organization and behavior. In this paper, we aim to explore the functional connectivity of brain network under a multi-step cognitive task involving consecutive behaviors, and further understand the effect of behaviors on the brain organization. The functional brain networks are constructed based on a high spatial and temporal resolution fMRI dataset and analyzed via complex network based approach. We find that at voxel level the functional brain network shows robust small-worldness and scale-free characteristics, while its assortativity and rich-club organization are slightly restricted to the order of behaviors performed. More interestingly, the functional connectivity of brain network in activated ROIs strongly correlates with behaviors and is obviously restricted to the order of behaviors performed. These empirical results suggest that the brain organization has the generic properties of small-worldness and scale-free characteristics, and its diverse functional connectivity emerging from activated ROIs is strongly driven by these behavioral activities via the plasticity of brain.

  10. Functional brain imaging of a complex navigation task following one night of total sleep deprivation

    Science.gov (United States)

    Strangman, Gary; Thompson, John H.; Strauss, Monica M.; Marshburn, Thomas H.; Sutton, Jeffrey P.

    2006-01-01

    Study Objectives: To assess the cerebral effects associated with sleep deprivation in a simulation of a complex, real-world, high-risk task. Design and Interventions: A two-week, repeated measures, cross-over experimental protocol, with counterbalanced orders of normal sleep (NS) and total sleep deprivation (TSD). Setting: Each subject underwent functional magnetic resonance imaging (fMRI) while performing a dual-joystick, 3D sensorimotor navigation task (simulated orbital docking). Scanning was performed twice per subject, once following a night of normal sleep (NS), and once following a single night of total sleep deprivation (TSD). Five runs (eight 24s docking trials each) were performed during each scanning session. Participants: Six healthy, young, right-handed volunteers (2 women; mean age 20) participated. Measurements and Results: Behavioral performance on multiple measures was comparable in the two sleep conditions. Neuroimaging results within sleep conditions revealed similar locations of peak activity for NS and TSD, including left sensorimotor cortex, left precuneus (BA 7), and right visual areas (BA 18/19). However, cerebral activation following TSD was substantially larger and exhibited higher amplitude modulations from baseline. When directly comparing NS and TSD, most regions exhibited TSD>NS activity, including multiple prefrontal cortical areas (BA 8/9,44/45,47), lateral parieto-occipital areas (BA 19/39, 40), superior temporal cortex (BA 22), and bilateral thalamus and amygdala. Only left parietal cortex (BA 7) demonstrated NS>TSD activity. Conclusions: The large network of cerebral differences between the two conditions, even with comparable behavioral performance, suggests the possibility of detecting TSD-induced stress via functional brain imaging techniques on complex tasks before stress-induced failures.

  11. An Automated, Adaptive Framework for Optimizing Preprocessing Pipelines in Task-Based Functional MRI.

    Directory of Open Access Journals (Sweden)

    Nathan W Churchill

    Full Text Available BOLD fMRI is sensitive to blood-oxygenation changes correlated with brain function; however, it is limited by relatively weak signal and significant noise confounds. Many preprocessing algorithms have been developed to control noise and improve signal detection in fMRI. Although the chosen set of preprocessing and analysis steps (the "pipeline" significantly affects signal detection, pipelines are rarely quantitatively validated in the neuroimaging literature, due to complex preprocessing interactions. This paper outlines and validates an adaptive resampling framework for evaluating and optimizing preprocessing choices by optimizing data-driven metrics of task prediction and spatial reproducibility. Compared to standard "fixed" preprocessing pipelines, this optimization approach significantly improves independent validation measures of within-subject test-retest, and between-subject activation overlap, and behavioural prediction accuracy. We demonstrate that preprocessing choices function as implicit model regularizers, and that improvements due to pipeline optimization generalize across a range of simple to complex experimental tasks and analysis models. Results are shown for brief scanning sessions (<3 minutes each, demonstrating that with pipeline optimization, it is possible to obtain reliable results and brain-behaviour correlations in relatively small datasets.

  12. An Automated, Adaptive Framework for Optimizing Preprocessing Pipelines in Task-Based Functional MRI.

    Science.gov (United States)

    Churchill, Nathan W; Spring, Robyn; Afshin-Pour, Babak; Dong, Fan; Strother, Stephen C

    2015-01-01

    BOLD fMRI is sensitive to blood-oxygenation changes correlated with brain function; however, it is limited by relatively weak signal and significant noise confounds. Many preprocessing algorithms have been developed to control noise and improve signal detection in fMRI. Although the chosen set of preprocessing and analysis steps (the "pipeline") significantly affects signal detection, pipelines are rarely quantitatively validated in the neuroimaging literature, due to complex preprocessing interactions. This paper outlines and validates an adaptive resampling framework for evaluating and optimizing preprocessing choices by optimizing data-driven metrics of task prediction and spatial reproducibility. Compared to standard "fixed" preprocessing pipelines, this optimization approach significantly improves independent validation measures of within-subject test-retest, and between-subject activation overlap, and behavioural prediction accuracy. We demonstrate that preprocessing choices function as implicit model regularizers, and that improvements due to pipeline optimization generalize across a range of simple to complex experimental tasks and analysis models. Results are shown for brief scanning sessions (<3 minutes each), demonstrating that with pipeline optimization, it is possible to obtain reliable results and brain-behaviour correlations in relatively small datasets.

  13. Decreased Modulation of EEG Oscillations in High-Functioning Autism during a Motor Control Task

    Science.gov (United States)

    Ewen, Joshua B.; Lakshmanan, Balaji M.; Pillai, Ajay S.; McAuliffe, Danielle; Nettles, Carrie; Hallett, Mark; Crone, Nathan E.; Mostofsky, Stewart H.

    2016-01-01

    Autism spectrum disorders (ASD) are thought to result in part from altered cortical excitatory-inhibitory balance; this pathophysiology may impact the generation of oscillations on electroencephalogram (EEG). We investigated premotor-parietal cortical physiology associated with praxis, which has strong theoretical and empirical associations with ASD symptomatology. Twenty five children with high-functioning ASD (HFA) and 33 controls performed a praxis task involving the pantomiming of tool use, while EEG was recorded. We assessed task-related modulation of signal power in alpha and beta frequency bands. Compared with controls, subjects with HFA showed 27% less left central (motor/premotor) beta (18–22 Hz) event-related desynchronization (ERD; p = 0.030), as well as 24% less left parietal alpha (7–13 Hz) ERD (p = 0.046). Within the HFA group, blunting of central ERD attenuation was associated with impairments in clinical measures of praxis imitation (r = −0.4; p = 0.04) and increased autism severity (r = 0.48; p = 0.016). The modulation of central beta activity is associated, among other things, with motor imagery, which may be necessary for imitation. Impaired imitation has been associated with core features of ASD. Altered modulation of oscillatory activity may be mechanistically involved in those aspects of motor network function that relate to the core symptoms of ASD. PMID:27199719

  14. Decreased Modulation of EEG Oscillations in High-Functioning Autism During a Motor Control Task

    Directory of Open Access Journals (Sweden)

    Joshua Benjamin Ewen

    2016-05-01

    Full Text Available Autism spectrum disorders (ASD are thought to result in part from altered cortical excitatory-inhibitory balance; this pathophysiology may impact the generation of oscillations on EEG. We investigated premotor-parietal cortical physiology associated with praxis, which has strong theoretical and empirical associations with ASD symptomatology. 25 children with high-functioning ASD (HFA and 33 controls performed a praxis task involving the pantomiming of tool use, while EEG was recorded. We assessed task-related modulation of signal power in alpha and beta frequency bands. Compared with controls, subjects with HFA showed 27% less left central (motor/premotor beta (18-22 Hz event-related desynchronization (ERD (p = 0.030, as well as 24% less left parietal alpha (7-13 Hz ERD (p = 0.046. Within the HFA group, blunting of central ERD attenuation was associated with impairments in clinical measures of praxis imitation (r = -0.4; p = 0.04 and increased autism severity (r = 0.48; p = 0.016. The modulation of central beta activity is associated, among other things, with motor imagery, which may be necessary for imitation. Impaired imitation has been associated with core features of ASD. Altered modulation of oscillatory activity may be mechanistically involved in those aspects of motor network function that relate to the core symptoms of ASD.

  15. Task-specific rehabilitation of finger-hand function using interactive computer gaming.

    Science.gov (United States)

    Szturm, Tony; Peters, James F; Otto, Chris; Kapadia, Naaz; Desai, Ankur

    2008-11-01

    The present case study assessed the feasibility of using an interactive gaming system, coupled with the manipulation of common objects, as a form of repetitive, task-specific movement therapy. Three adults with moderate chronic motor impairments of the fingers and hand participated: one 36-year-old man with an incomplete cervical spinal cord injury, one 60-year-old man with a left cortical cerebro-vascular accident, and one 38-year-old woman with left hemiplegic cerebral palsy. Each subject received an intervention of 15 one-hour sessions, which consisted solely of interactive exercise gaming using a diverse range of objects. The objects provided graded and challenging training levels, which emulated the functional properties of objects used in daily life. This in turn produced positive effects on the recovery of active finger range of motion and hand function.

  16. Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

    Science.gov (United States)

    Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

    2016-02-01

    When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention.

  17. Sex differences in brain activation pattern during a visuospatial cognitive task: a functional magnetic resonance imaging study in healthy volunteers.

    Science.gov (United States)

    Weiss, E; Siedentopf, C M; Hofer, A; Deisenhammer, E A; Hoptman, M J; Kremser, C; Golaszewski, S; Felber, S; Fleischhacker, W W; Delazer, M

    2003-07-03

    Sex differences in mental rotation tasks, favoring men, have been noted in behavioral studies and functional imaging studies. In the present study ten female and ten male volunteers underwent functional magnetic resonance imaging in a conventional block design. Regions of activation were detected after performance of a mental rotation task inside the scanner. In contrast to previous studies, confounding factors such as performance differences between genders or high error rates were excluded. Men showed significantly stronger parietal activation, while women showed significantly greater right frontal activation. Our results point to gender specific differences in the neuropsychological processes involved in mental rotation tasks.

  18. A systematic review of repetitive functional task practice with modelling of resource use, costs and effectiveness.

    Science.gov (United States)

    French, B; Leathley, M; Sutton, C; McAdam, J; Thomas, L; Forster, A; Langhorne, P; Price, C; Walker, A; Watkins, C

    2008-07-01

    To determine whether repetitive functional task practice (RFTP) after stroke improves limb-specific or global function or activities of daily living and whether treatment effects are dependent on the amount of practice, or the type or timing of the intervention. Also to provide estimates of the cost-effectiveness of RFTP. The main electronic databases were searched from inception to week 4, September 2006. Searches were also carried out on non-English-language databases and for unpublished trials up to May 2006. Standard quantitative methods were used to conduct the systematic review. The measures of efficacy of RFTP from the data synthesis were used to inform an economic model. The model used a pre-existing data set and tested the potential impact of RFTP on cost. An incremental cost per quality-adjusted life-year (QALY) gained for RFTP was estimated from the model. Sensitivity analyses around the assumptions made for the model were used to test the robustness of the estimates. Thirty-one trials with 34 intervention-control pairs and 1078 participants were included. Overall, it was found that some forms of RFTP resulted in improvement in global function, and in both arm and lower limb function. Overall standardised mean difference in data suitable for pooling was 0.38 [95% confidence interval (CI) 0.09 to 0.68] for global motor function, 0.24 (95% CI 0.06 to 0.42) for arm function and 0.28 (95% CI 0.05 to 0.51) for functional ambulation. Results suggest that training may be sufficient to have an impact on activities of daily living. Retention effects of training persist for up to 6 months, but whether they persist beyond this is unclear. There was little or no evidence that treatment effects overall were modified by time since stroke or dosage of task practice, but results for upper limb function were modified by type of intervention. The economic modelling suggested that RFTP was cost-effective. Given a threshold for cost-effectiveness of 20,000 pounds per QALY

  19. A novel device for grasping assessment during functional tasks: preliminary results

    Directory of Open Access Journals (Sweden)

    Ana Carolinne Portela Rocha

    2016-02-01

    Full Text Available This paper presents a methodology and first results obtained in a study with a novel device that allows the analysis of grasping quality. Such a device is able to acquire motion information of upper limbs allowing kinetic of manipulation analysis as well. A pilot experiment was carried out with six groups of typically developing children aged between 5 and 10 years old, with 7-8 children in each one. The device, designed to emulate a glass, has an optical system composed by one digital camera and a special convex mirror that together allow image acquisition of grasping hand posture when it is grasped and manipulated. It also carries an Inertial Measurement Unit (IMU that captures motion data as acceleration, orientation, and angular velocities. The novel instrumented object is used in our approach to evaluate functional tasks performance in quantitative terms. During tests each child was invited to grasp the cylindrical part of the device that was placed on the top of a table, simulating the task of drinking a glass of water. In the sequence the child was oriented to transport the device back to the starting position and release it. The task was repeated 3 times for each child. A grasping hand posture evaluation is presented as an example to evaluate grasping quality. Additionally, motion patterns obtained with the triasl performed with the different groups are presented and discussed. This device is attractive due to its portable characteristics, the small size and its ability to evaluate grasping form. The results may be also useful to analyze the evolution of the rehabilitation process through reach-to-grasping movement and the grasping images analysis.

  20. Does extending the dual-task functional exercises workout improve postural balance in individuals with ID?

    Science.gov (United States)

    Mikolajczyk, Edyta; Jankowicz-Szymanska, Agnieszka

    2015-03-01

    Maintaining postural balance, overcoming visual and motor coordination disorders and experiencing problems with low general fitness - typical of intellectually disabled individuals - adversely affect the performance quality of their activities of daily living (ADLs). Physical fitness and postural balance can be improved by taking part in special intervention programs. Our study was designed to test whether extending the dual-task intervention program (combining ADLs with balance exercises on unstable surfaces) from 12 to 24 weeks additionally improved postural balance in individuals with intellectual disability (ID). We also attempted to assess whether the effects of the above intervention program were still noticeable after 8 weeks of holidays, in which participants did not take any rehabilitation exercises. A total of 34 adolescents, aged 14-16 years (15.06±0.9), with moderate ID took part in our study. The experimental group (E) consisted of 17 individuals, who continued the intervention program originated 3 months earlier, and the control group (C) comprised the same number of participants. Postural balance was assessed on a stabilometric platform Alfa. Having extended the workout period by another 12 weeks, we noticed that the path length of the center of pressure (COP) covered by participants on tests with their eyes open and closed significantly shortened. After a lapse of 8 weeks from the completion of the program, the experimental group revealed a statistically significant decrease in the velocity along the medio-lateral (M/L) and anterior-posterior (A/P) axes. The remaining variables stayed at the same level and the control group did not demonstrate any statistically significant changes. Dual-task exercises, in which enhancing functional tasks of daily living is combined with a parallel stimulation of balance reactions, may improve static balance in persons with ID.

  1. Disability assessment interview : the role of detailed information on functioning in addition to medical history-taking

    NARCIS (Netherlands)

    Spanjer, J.; Krol, B.; Popping, R.; Groothoff, J.W.; Brouwer, Sandra

    Objective: To investigate whether the provision of detailed information on participation and activity limitations, compared with medical information alone, influences the assessment of work limitations by physicians. Methods: Three groups each of 9 insurance physicians used written interview reports

  2. Interaction between anesthesia, gender, and functional outcome task following diffuse traumatic brain injury in rats.

    Science.gov (United States)

    O'Connor, Christine A; Cernak, Ibolja; Vink, Robert

    2003-06-01

    A number of experimental and clinical studies have demonstrated that functional outcome following traumatic brain injury differs between males and females. Some studies report that females have a better outcome than males following trauma while others report the opposite. In experimental studies, some of the contradictory results may be due to the different experimental conditions, including type of anesthesia and the outcome measures employed. In the present study we have used three different anesthetic protocols and four different outcome measures to determine how these parameters interact and affect functional outcome following traumatic brain injury in male and female rats. Diffuse traumatic brain injury was induced in adult male and female animals using the impact-acceleration brain injury model. Mortality in female animals was no different than males when using halothane anesthesia, slightly better than males when using isoflurane anesthesia, but significantly worse than males under pentobarbital anesthesia. Female animals always performed better than males on rotarod tests of motor outcome, with this effect being unrelated to anesthetic effects. Conversely, in cognitive tests using the Barnes Maze, only isoflurane-anesthetized females performed better than their male counterparts. Similarly, in an open field activity task, females always performed better than males after trauma, with isoflurane-anesthetized females also performing significantly better than the halothane-anesthetized female group after injury. Our results suggest that female animals do better than males after diffuse traumatic brain injury, although this observation is dependent upon the type of anesthesia and the functional task employed. Isoflurane is particularly protective in females, pentobarbital is deleterious to female outcome, while halothane anesthesia has the least influence on gender-related outcome.

  3. Maintaining Gait Performance by Cortical Activation during Dual-Task Interference: A Functional Near-Infrared Spectroscopy Study.

    Directory of Open Access Journals (Sweden)

    Chia-Feng Lu

    Full Text Available In daily life, mobility requires walking while performing a cognitive or upper-extremity motor task. Although previous studies have evaluated the effects of dual tasks on gait performance, few studies have evaluated cortical activation and its association with gait disturbance during dual tasks. In this study, we simultaneously assessed gait performance and cerebral oxygenation in the bilateral prefrontal cortices (PFC, premotor cortices (PMC, and supplemental motor areas (SMA, using functional near-infrared spectroscopy, in 17 young adults performing dual tasks. Each participant was evaluated while performing normal-pace walking (NW, walking while performing a cognitive task (WCT, and walking while performing a motor task (WMT. Our results indicated that the left PFC exhibited the strongest and most sustained activation during WCT, and that NW and WMT were associated with minor increases in oxygenation levels during their initial phases. We observed increased activation in channels in the SMA and PMC during WCT and WMT. Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties. WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only. During dual-task activities, increased activation of the PMC and SMA correlated with declines in gait performance, indicating a control mechanism for maintaining gait performance during dual tasks. Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

  4. Maintaining Gait Performance by Cortical Activation during Dual-Task Interference: A Functional Near-Infrared Spectroscopy Study.

    Science.gov (United States)

    Lu, Chia-Feng; Liu, Yan-Ci; Yang, Yea-Ru; Wu, Yu-Te; Wang, Ray-Yau

    2015-01-01

    In daily life, mobility requires walking while performing a cognitive or upper-extremity motor task. Although previous studies have evaluated the effects of dual tasks on gait performance, few studies have evaluated cortical activation and its association with gait disturbance during dual tasks. In this study, we simultaneously assessed gait performance and cerebral oxygenation in the bilateral prefrontal cortices (PFC), premotor cortices (PMC), and supplemental motor areas (SMA), using functional near-infrared spectroscopy, in 17 young adults performing dual tasks. Each participant was evaluated while performing normal-pace walking (NW), walking while performing a cognitive task (WCT), and walking while performing a motor task (WMT). Our results indicated that the left PFC exhibited the strongest and most sustained activation during WCT, and that NW and WMT were associated with minor increases in oxygenation levels during their initial phases. We observed increased activation in channels in the SMA and PMC during WCT and WMT. Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties. WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only. During dual-task activities, increased activation of the PMC and SMA correlated with declines in gait performance, indicating a control mechanism for maintaining gait performance during dual tasks. Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.

  5. Diet-Induced Weight Loss Alters Functional Brain Responses during an Episodic Memory Task.

    Science.gov (United States)

    Boraxbekk, Carl-Johan; Stomby, Andreas; Ryberg, Mats; Lindahl, Bernt; Larsson, Christel; Nyberg, Lars; Olsson, Tommy

    2015-01-01

    It has been suggested that overweight is negatively associated with cognitive functions. The aim of this study was to investigate whether a reduction in body weight by dietary interventions could improve episodic memory performance and alter associated functional brain responses in overweight and obese women. 20 overweight postmenopausal women were randomized to either a modified paleolithic diet or a standard diet adhering to the Nordic Nutrition Recommendations for 6 months. We used functional magnetic resonance imaging to examine brain function during an episodic memory task as well as anthropometric and biochemical data before and after the interventions. Episodic memory performance improved significantly (p = 0.010) after the dietary interventions. Concomitantly, brain activity increased in the anterior part of the right hippocampus during memory encoding, without differences between diets. This was associated with decreased levels of plasma free fatty acids (FFA). Brain activity increased in pre-frontal cortex and superior/middle temporal gyri. The magnitude of increase correlated with waist circumference reduction. During episodic retrieval, brain activity decreased in inferior and middle frontal gyri, and increased in middle/superior temporal gyri. Diet-induced weight loss, associated with decreased levels of plasma FFA, improves episodic memory linked to increased hippocampal activity. © 2015 S. Karger GmbH, Freiburg.

  6. Diet-Induced Weight Loss Alters Functional Brain Responses during an Episodic Memory Task

    Directory of Open Access Journals (Sweden)

    Carl-Johan Boraxbekk

    2015-07-01

    Full Text Available Objective: It has been suggested that overweight is negatively associated with cognitive functions. The aim of this study was to investigate whether a reduction in body weight by dietary interventions could improve episodic memory performance and alter associated functional brain responses in overweight and obese women. Methods: 20 overweight postmenopausal women were randomized to either a modified paleolithic diet or a standard diet adhering to the Nordic Nutrition Recommendations for 6 months. We used functional magnetic resonance imaging to examine brain function during an episodic memory task as well as anthropometric and biochemical data before and after the interventions. Results: Episodic memory performance improved significantly (p = 0.010 after the dietary interventions. Concomitantly, brain activity increased in the anterior part of the right hippocampus during memory encoding, without differences between diets. This was associated with decreased levels of plasma free fatty acids (FFA. Brain activity increased in pre-frontal cortex and superior/middle temporal gyri. The magnitude of increase correlated with waist circumference reduction. During episodic retrieval, brain activity decreased in inferior and middle frontal gyri, and increased in middle/superior temporal gyri. Conclusions: Diet-induced weight loss, associated with decreased levels of plasma FFA, improves episodic memory linked to increased hippocampal activity.

  7. Functional Activation and Effective Connectivity Differences in Adolescent Marijuana Users Performing a Simulated Gambling Task

    Directory of Open Access Journals (Sweden)

    Ashley Acheson

    2015-01-01

    Full Text Available Background. Adolescent marijuana use is associated with structural and functional differences in forebrain regions while performing memory and attention tasks. In the present study, we investigated neural processing in adolescent marijuana users experiencing rewards and losses. Fourteen adolescents with frequent marijuana use (>5 uses per week and 14 nonuser controls performed a computer task where they were required to guess the outcome of a simulated coin flip while undergoing magnetic resonance imaging. Results. Across all participants, “Wins” and “Losses” were associated with activations including cingulate, middle frontal, superior frontal, and inferior frontal gyri and declive activations. Relative to controls, users had greater activity in the middle and inferior frontal gyri, caudate, and claustrum during “Wins” and greater activity in the anterior and posterior cingulate, middle frontal gyrus, insula, claustrum, and declive during “Losses.” Effective connectivity analyses revealed similar overall network interactions among these regions for users and controls during both “Wins” and “Losses.” However, users and controls had significantly different causal interactions for 10 out of 28 individual paths during the “Losses” condition. Conclusions. Collectively, these results indicate adolescent marijuana users have enhanced neural responses to simulated monetary rewards and losses and relatively subtle differences in effective connectivity.

  8. Author Details

    African Journals Online (AJOL)

    Autism spectrum disorders (ASD) in Africa: a perspective ... Functional status and its associated factors in Nigerian adolescents with bipolar disorder ... Attention deficit hyperactivity symptoms and disorder (ADHD) among African children: a ...

  9. Detailed study of grooved heat pipes for a system functioning study; Etude fine des caloducs rainures en vue d`une etude systeme

    Energy Technology Data Exchange (ETDEWEB)

    Alexandre, A. [Ecole Nationale Superieure de Mecanique et d`Aerotechnique (ENSMA), 86 - Poitiers (France)

    1996-12-31

    The functioning of a heat pipe is complex. In this paper, a methodology for a detailed analysis of the functioning of a grooved heat pipe is developed in order to obtain the information required for a general analysis of such systems. (J.S.) 3 refs.

  10. Task-based factors influencing the successful functioning of copreneurial businesses in South Africa

    Directory of Open Access Journals (Sweden)

    Shelley Farrington

    2011-03-01

    Full Text Available Globally, evidence exists to suggest that the number of copreneurial businesses or spousal partnerships are on the increase. The primary objectives of this study are to identify the task-based factors influencing the effectiveness of a copreneurial business, to propose a conceptual model based on these factors and to subject the model to empirical testing. The model is empirically tested among copreneurial businesses to assess potential relationships between selected independent variables (shared dream, leadership, personal needs alignment, division of labour, complementary skills, supportive employees, competencies and adequate resources and measures of copreneurial success (perceived success and financial performance. In order to address the primary objective of this study, a questionnaire was administered to a sample of 1548 respondents (spouses in business together of which 380 questionnaires were useable for statistical analysis. The empirical results revealed that apart from division of labour all the other factors investigated exert a significant influence on the successful functioning of copreneurial businesses.

  11. A functional approach for research on cognitive control: Analysing cognitive control tasks and their effects in terms of operant conditioning.

    Science.gov (United States)

    Liefooghe, Baptist; De Houwer, Jan

    2016-02-01

    Cognitive control is an important mental ability that is examined using a multitude of cognitive control tasks and effects. The present paper presents the first steps in the elaboration of a functional approach, which aims to uncover the communalities and differences between different cognitive control tasks and their effects. Based on the idea that responses in cognitive control tasks qualify as operant behaviour, we propose to reinterpret cognitive control tasks in terms of operant contingencies and cognitive control effects as instances of moderated stimulus control. We illustrate how our approach can be used to uncover communalities between topographically different cognitive control tasks and can lead to novel questions about the processes underlying cognitive control.

  12. Brain functional network connectivity based on a visual task: visual information processing-related brain regions are significantly activated in the task state.

    Science.gov (United States)

    Yang, Yan-Li; Deng, Hong-Xia; Xing, Gui-Yang; Xia, Xiao-Luan; Li, Hai-Fang

    2015-02-01

    It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

  13. Brain functional network connectivity based on a visual task: visual information processing-related brain regions are significantly activated in the task state

    Directory of Open Access Journals (Sweden)

    Yan-li Yang

    2015-01-01

    Full Text Available It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

  14. Changes across the psychometric function following perceptual learning of an RSVP reading task

    Directory of Open Access Journals (Sweden)

    Daniel Robert Coates

    2014-12-01

    Full Text Available Several recent studies have shown that perceptual learning can result in improvements inreading speed for people with macular disease (e.g. Chung, 2011; Tarita-Nistor et al., 2014.The improvements were reported as an increase in reading speed defined by specific criteria;however, little is known about how other properties of the reading performance or the participantsperceptual responses change as a consequence of learning. In this paper, we performeddetailed analyses of data following perceptual learning using an RSVP (rapid serial visualpresentation reading task, looking beyond the change in reading speed defined by the thresholdat a given accuracy on a psychometric function relating response accuracy with word exposureduration. Specifically, we explored the statistical characteristics of theresponse data to address two specific questions: was there a change in theslope of the psychometric function and did the improvements in performance occurconsistently across different word exposure durations? Our results show thatthere is a general steepening of the slope of the psychometric function, leadingto non-uniform improvements across stimulus levels.

  15. The role of spectral detail in the binaural transfer function on perceived externalization in a reverberant environment

    DEFF Research Database (Denmark)

    Hassager, Henrik Gert; Gran, Fredrik; Dau, Torsten

    2016-01-01

    . For various filter bandwidths, the modified BRIRs were convolved with broadband noise and listeners judged the perceived position of the noise when virtualized over headphones. Only reductions in spectral details of the direct part obtained with filter bandwidths broader than one equivalent rectangular...

  16. Effects on visual functions during tasks of object handling in virtual environment with a head mounted display.

    Science.gov (United States)

    Kawara, T; Ohmi, M; Yoshizawa, T

    1996-11-01

    This study examined the effects on visual functions of a prolonged handling task within the helmet-mounted display environment. Both version eye movement and accommodative response became gradually slower during the 40-min task. Although delayed presentation of display after head movement noticeably worsened both visual responses, presentation delay after hand movement did not significantly change the sluggishness of responses. Therefore it is suggested that decreasing time delay after head movement is a more important factor in order to improve human performance of handling tasks within the HMD environment.

  17. Assessing language and visuospatial functions with one task: a "dual use" approach to performing fMRI in children.

    Science.gov (United States)

    Ebner, Kathina; Lidzba, Karen; Hauser, Till-Karsten; Wilke, Marko

    2011-10-01

    In order to increase the rate of successful functional MR studies in children it is helpful to shorten the time spent in the scanner. To this effect, assessing two cognitive functions with one task seems to be a promising approach. The hypothesis of this study was that the control condition of an established language task (vowel identification task, VIT) requires visuospatial processing and that the control condition (VIT(CC)) therefore may also be applicable to localize visuospatial functions. As a reference task, a visual search task (VST, previously established for use in children) was employed. To test this hypothesis, 43 children (19 f, 24 m; 12.0±2.6, range 7.9 to 17.8 years) were recruited and scanned using both tasks. Second-level random effects group analyses showed activation of left inferior-frontal cortex in the active condition of the VIT, as in previous studies. Additionally, analysis of the VIT(CC) demonstrated activation in right-dominant superior parietal and high-frontal brain regions, classically associated with visuospatial functions; activation seen in the VST was similar with a substantial overlap. However, lateralization in the parietal lobe was significantly more bilateral in the VST than in the VIT(CC). This suggests that the VIT can not only be applied to assess language functions (using the active>control contrast), but also that the control>active condition is useful for assessing visuospatial functions. Future task design may benefit from such a "dual use" approach to performing fMRI not only, but also particularly in children.

  18. Effects of chronic neck-shoulder pain on normalized mutual information analysis of surface electromyography during functional tasks

    DEFF Research Database (Denmark)

    Madeleine, Pascal; Xie, Yanfei; Szeto, Grace P. Y.;

    2016-01-01

    OBJECTIVE: To investigate the effects neck-shoulder pain on the connectivity of surface electromyography (SEMG) signals during functional tasks. METHODS: Twenty adults suffering from chronic neck-shoulder pain and 20 healthy controls were recruited. The SEMG signals from the left and right proximal....... Moreover, NMI values in homonymous proximal muscles were higher during texting compared with computer typing with both hands. CONCLUSIONS: Our results show for the first time that chronic neck-shoulder pain affects the functional connectivity of muscle pairs. SIGNIFICANCE: The study furnishes novel...... information about the effects of chronic neck-shoulder pain on the interplay of muscle pairs during functional tasks....

  19. Simple and Task-oriented Mirror Therapy for Upper Extremity Function in Stroke Patients: A Pilot Study

    OpenAIRE

    Young-Rim Paik; Su-Kyoung Kim; Jae-Shin Lee; Byoung-Jin Jeon

    2014-01-01

    Objective/Background: To compare the effects of simple and task-oriented mirror therapies on upper extremity function in stroke patients with hemiplegia. Methods: A single-subject, reversal (applied behaviour analysis) research design was used, and the study included four patients and two treatments. Treatment 1 involved simple mirror therapy that was performed using simple upper limb movements. Treatment 2 involved task-oriented mirror therapy that required each patient to perform functio...

  20. Simple and Task-oriented Mirror Therapy for Upper Extremity Function in Stroke Patients: A Pilot Study

    OpenAIRE

    Young-Rim Paik; Su-Kyoung Kim; Jae-Shin Lee; Byoung-Jin Jeon

    2014-01-01

    Objective/Background: To compare the effects of simple and task-oriented mirror therapies on upper extremity function in stroke patients with hemiplegia. Methods: A single-subject, reversal (applied behaviour analysis) research design was used, and the study included four patients and two treatments. Treatment 1 involved simple mirror therapy that was performed using simple upper limb movements. Treatment 2 involved task-oriented mirror therapy that required each patient to perform functio...

  1. Investigation of attention via the counting Stroop task in patients with functional constipation

    Institute of Scientific and Technical Information of China (English)

    SUN Yi; LI Xiao-yi; YAO Lin-yan; ZHAO Lan; DAI Ning; WU Hao

    2012-01-01

    Background The etiology and pathology of functional constipation (FC) is unclear.Some researches suggest that psychological factors may be related to this common problem.This study aimed to investigate the relationship between attention processing and emotional status in FC patients compared with healthy controls.Methods We investigated selective attention and emotional status in patients with FC using the counting Stroop task.Thirty-five FC patients (FCP group) and 24 healthy controls (HCs) underwent an event-related potential (ERP) study while performing the task.Response time,latency and amplitude of P300 were collected and compared between the two groups.The Hamilton Depression Rating Scale (HAMD-17),Hamilton Anxiety Scale (HAMA),Symptom Checklist-90 (SCL-90) and Eysenck Personality Questionnaire (EPQ) were administered prior to the counting Stroop task.Results Scores for the FCP group differed significantly from those for the HCs on the HAMD-17,HAMA,SCL-90 (Global Severity Index,Positive Symptoms Total,dimensions of somatization,obsessive-compulsive,depression,anxiety,and psychosis),as well as extraversion and neurosis dimensions of the EPQ (P<0.05).There was no significant difference in response time or accuracy rate between the two groups (P>0.05).ERP results showed prolonged latency at F4,additionally found enhanced activation at F3,FC1 and T8,and decreased activation at sites FC6 and P7 in the patients with FC.Statistically,significant differences of P300 latency at site F4 (P <0.05) and P300 amplitude at F3,F4,T8,P7,FC1 and FC6 (P<0.05) between the patients with FC and the HC were revealed.Conclusions The findings suggest that patients with FC are more susceptible to depression and anxiety,as well as somatization,obsessive-compulsive tendencies and other neurotic personality characteristics.Patients may employ psychological defense mechanisms to avoid the pain of depression and anxiety.ERP results imply there may be some brain dysfunction and

  2. Prefrontal Hemodynamic Functions during a Verbal Fluency Task in Blepharospasm Using Multi-Channel NIRS.

    Directory of Open Access Journals (Sweden)

    Chen-Yu Shen

    Full Text Available Blepharospasm (BSP has a morbidity of 16 to 133 per million and is characterized by orbicularis oculi spasms. BSP can severely impact daily life. However, to date, its pathophysiology has not been clearly demonstrated. Near-infrared spectroscopy (NIRS is a portable, non-invasive, and high time resolution apparatus used to measure cerebral blood flow. This study aimed to investigate the hemodynamic response patterns of BSP patients and determine whether BSP alone can be an attributional factor to influence the function of the prefrontal area using a verbal fluency task (VFT and NIRS. Twenty-three BSP patients (10 males and 13 females and 13 healthy controls (HC; five males and eight females matched by gender and education were examined using NIRS. BSP patients were divided into two groups based on the presence or absence of depression and anxiety symptoms. A covariance analysis was conducted to analyze differences between the three groups and reduce the influence of different ages and educational levels. Bonferroni was used to process the post hoc test. The bilateral orbitofrontal area (ch36, 39, and 41; P<0.01 exhibited a lower activation in BSP patients without psychiatric symptoms compared with HC. This study is the first report to identify the prefrontal function in BSP using NIRS. Our findings indicate that BSP alone may cause a hypoactive hemodynamic performance in the prefrontal cortex in the absence of psychiatric symptoms. These findings provide evidence to support novel pathophysiological mechanisms of BSP.

  3. Beta and gamma oscillatory activities associated with olfactory memory tasks: Different rhythms for different functional networks?

    Directory of Open Access Journals (Sweden)

    Claire eMartin

    2014-06-01

    Full Text Available Olfactory processing in behaving animals, even at early stages, is inextricable from top down influences associated with odor perception. The anatomy of the olfactory network (olfactory bulb, piriform and entorhinal cortices and its unique direct access to the limbic system makes it particularly attractive to study how sensory processing could be modulated by learning and memory. Moreover, olfactory structures have been early reported to exhibit oscillatory population activities easy to capture through local field potential recordings. An attractive hypothesis is that neuronal oscillations would serve to ‘bind’ distant structures to reach a unified and coherent perception. In relation to this hypothesis, we will assess the functional relevance of different types of oscillatory activity observed in the olfactory system of behaving animals. This review will focus primarily on two types of oscillatory activities: beta (15-40 Hz and gamma (60-100 Hz. While gamma oscillations are dominant in the olfactory system in the absence of odorant, both beta and gamma rhythms have been reported to be modulated depending on the nature of the olfactory task. Studies from the authors of the present review and other groups brought evidence for a link between these oscillations and behavioral changes induced by olfactory learning. However, differences in studies led to divergent interpretations concerning the respective role of these oscillations in olfactory processing. Based on a critical reexamination of those data, we propose hypotheses on the functional involvement of beta and gamma oscillations for odor perception and memory.

  4. Operator function modeling: Cognitive task analysis, modeling and intelligent aiding in supervisory control systems

    Science.gov (United States)

    Mitchell, Christine M.

    1990-01-01

    The design, implementation, and empirical evaluation of task-analytic models and intelligent aids for operators in the control of complex dynamic systems, specifically aerospace systems, are studied. Three related activities are included: (1) the models of operator decision making in complex and predominantly automated space systems were used and developed; (2) the Operator Function Model (OFM) was used to represent operator activities; and (3) Operator Function Model Expert System (OFMspert), a stand-alone knowledge-based system was developed, that interacts with a human operator in a manner similar to a human assistant in the control of aerospace systems. OFMspert is an architecture for an operator's assistant that uses the OFM as its system and operator knowledge base and a blackboard paradigm of problem solving to dynamically generate expectations about upcoming operator activities and interpreting actual operator actions. An experiment validated the OFMspert's intent inferencing capability and showed that it inferred the intentions of operators in ways comparable to both a human expert and operators themselves. OFMspert was also augmented with control capabilities. An interface allowed the operator to interact with OFMspert, delegating as much or as little control responsibility as the operator chose. With its design based on the OFM, OFMspert's control capabilities were available at multiple levels of abstraction and allowed the operator a great deal of discretion over the amount and level of delegated control. An experiment showed that overall system performance was comparable for teams consisting of two human operators versus a human operator and OFMspert team.

  5. Task Analytic Models to Guide Analysis and Design: Use of the Operator Function Model to Represent Pilot-Autoflight System Mode Problems

    Science.gov (United States)

    Degani, Asaf; Mitchell, Christine M.; Chappell, Alan R.; Shafto, Mike (Technical Monitor)

    1995-01-01

    Task-analytic models structure essential information about operator interaction with complex systems, in this case pilot interaction with the autoflight system. Such models serve two purposes: (1) they allow researchers and practitioners to understand pilots' actions; and (2) they provide a compact, computational representation needed to design 'intelligent' aids, e.g., displays, assistants, and training systems. This paper demonstrates the use of the operator function model to trace the process of mode engagements while a pilot is controlling an aircraft via the, autoflight system. The operator function model is a normative and nondeterministic model of how a well-trained, well-motivated operator manages multiple concurrent activities for effective real-time control. For each function, the model links the pilot's actions with the required information. Using the operator function model, this paper describes several mode engagement scenarios. These scenarios were observed and documented during a field study that focused on mode engagements and mode transitions during normal line operations. Data including time, ATC clearances, altitude, system states, and active modes and sub-modes, engagement of modes, were recorded during sixty-six flights. Using these data, seven prototypical mode engagement scenarios were extracted. One scenario details the decision of the crew to disengage a fully automatic mode in favor of a semi-automatic mode, and the consequences of this action. Another describes a mode error involving updating aircraft speed following the engagement of a speed submode. Other scenarios detail mode confusion at various phases of the flight. This analysis uses the operator function model to identify three aspects of mode engagement: (1) the progress of pilot-aircraft-autoflight system interaction; (2) control/display information required to perform mode management activities; and (3) the potential cause(s) of mode confusion. The goal of this paper is twofold

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

    Science.gov (United States)

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

    2015-05-01

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

  7. Investigation of the prefrontal cortex in response to duration-variable anagram tasks using functional near-infrared spectroscopy

    Science.gov (United States)

    Tian, Fenghua; Chance, Britton; Liu, Hanli

    2009-09-01

    We hypothesize that nonlinearity between short-term anagram tasks and corresponding hemodynamic responses can be observed by functional near-infrared spectroscopy (fNIRS) in the prefrontal cortex (PFC). The PFC of six human subjects in response to anagram tasks is investigated using multichannel fNIRS. Concentration changes of oxyhemoglobin and deoxyhemoglobin in the PFC are measured with variable anagram durations and at two difficulty levels (four- and six-letter anagrams). The durations to perform the selected anagram tasks range from several seconds to more than one minute. The dorsolateral PFC areas exhibit consistent and strong hemodynamic deactivation during and shortly after task execution. The superposition principle of a linear system is employed to investigate nonlinear hemodynamic features among three task duration subgroups: D1 = 2.0 sec, D2 = 4.0 sec, and D3 = 8.0 sec. Such analysis shows clear nonlinearity in hemodynamic responses on the PFC with task durations shorter than 4 sec. Our observation of significant deactivation in early hemodynamic responses in the PFC is consistent with multiple fNIRS studies and several reports given in the field of functional magnetic resonance imaging. A better understanding of nonlinearity in fNIRS signals will have potential for us to investigate brain adaptation and to extrapolate neuronal activities from hemodynamic signals.

  8. TASK-3 knockout mice exhibit exaggerated nocturnal activity, impairments in cognitive functions, and reduced sensitivity to inhalation anesthetics.

    Science.gov (United States)

    Linden, Anni-Maija; Sandu, Cristina; Aller, M Isabel; Vekovischeva, Olga Y; Rosenberg, Per H; Wisden, William; Korpi, Esa R

    2007-12-01

    The TASK-3 channel is an acid-sensitive two-pore-domain K+ channel, widely expressed in the brain and probably involved in regulating numerous neuronal populations. Here, we characterized the behavioral and pharmacological phenotypes of TASK-3 knockout (KO) mice. Circadian locomotor activity measurements revealed that the nocturnal activity of the TASK-3 KO mice was increased by 38% (P walking on a rotating rod or along a 1.2-cm-diameter beam. However, they fell more frequently from a narrower 0.8-cm beam. The KO mice showed impaired working memory in the spontaneous alternation task, with the alternation percentage being 62 +/- 3% for the wild-type mice and 48 +/- 4% (P rhythms, cognitive functions, and mediating specific pharmacological effects.

  9. Lower limb muscle coactivation levels in healthy younger and older adults during functional dual-task gait

    Directory of Open Access Journals (Sweden)

    Camilla Zamfolini Hallal

    2013-09-01

    Full Text Available The purpose of this study was to investigate the influence of daily cognitive task on stiffness of old and young female adults during the gait. The study included 17 physically active younger and 18 older women, with low risk of falls. The volunteers were asked to walk on the treadmill at two different gait conditions: normal gait and functional dual-task gait. The electromyographic signals were collected of the lower limb muscles. The percentage of coactivation for the tibialis anterior/gastrocnemius lateralis and tibialis anterior/soleus were significantly higher in elderly than in younger in the normal gait and dual-task gait. Our results suggest that the elderly have a greater stiffness in the ankle joint during gait normal and daily dual task gait. Thus, we conclude that challenging cognitively situations during the gait may increase the risk of falls in this population.

  10. Adaptive strategy changes as a function of task demands : a study of car drivers

    NARCIS (Netherlands)

    Cnossen, F; Meijman, T; Rothengatter, T; Rothengatter, J.A.

    2004-01-01

    When drivers perform additional tasks while driving, research shows conflicting results: primary driving performance may deteriorate but adaptive changes such as reducing driving speed have also been noted. We hypothesized that the nature of the secondary task may be important: drivers may give more

  11. Effects of a standing and three dynamic workstations on computer task performance and cognitive function tests

    NARCIS (Netherlands)

    Commissaris, D.A.C.M.; Könemann, R.; Hiemstra-van Mastrigt, S.; Burford, E.M.; Botter, J.; Douwes, M.; Ellegast, R.P.

    2014-01-01

    Sedentary work entails health risks. Dynamic (or active) workstations, at which computer tasks can be combined with physical activity, may reduce the risks of sedentary behaviour. The aim of this study was to evaluate short term task performance while working on three dynamic workstations: a treadmi

  12. Assessing cognitive load distributions for envisioned task allocations and support functions

    NARCIS (Netherlands)

    Neerincx, M.A.; Dobbelsteen, G.J.H. van den; Grootjen, M.; Veenendaal, J. van

    2003-01-01

    Information technology provides new possibilities to combine and support operator tasks in order to improve the operational effectiveness and efficiency on board of a ship. The general question is how to design a task allocation and support system that lead to an adequate deployment of the human cog

  13. Framing Human-Robot Task Communication as a POMDP

    CERN Document Server

    Woodward, Mark P

    2012-01-01

    As general purpose robots become more capable, pre-programming of all tasks at the factory will become less practical. We would like for non-technical human owners to be able to communicate, through interaction with their robot, the details of a new task; we call this interaction "task communication". During task communication the robot must infer the details of the task from unstructured human signals and it must choose actions that facilitate this inference. In this paper we propose the use of a partially observable Markov decision process (POMDP) for representing the task communication problem; with the unobservable task details and unobservable intentions of the human teacher captured in the state, with all signals from the human represented as observations, and with the cost function chosen to penalize uncertainty. We work through an example representation of task communication as a POMDP, and present results from a user experiment on an interactive virtual robot, compared with a human controlled virtual...

  14. Manifestation of incompleteness in obsessive-compulsive disorder (OCD as reduced functionality and extended activity beyond task completion.

    Directory of Open Access Journals (Sweden)

    Rama Zor

    Full Text Available BACKGROUND: This study focused on hypotheses regarding the source of incompleteness in obsessive-compulsive disorder (OCD. For this, we had to document the behavioral manifestation of incompleteness in compulsive rituals, predicting that an exaggerated focus on acts that are appropriate for the task will support the hypothesis on heightened responsibility/perfectionism. In contrast, activity past the expected terminal act for the motor task would support the "stop signal deficiency" hypothesis. METHODOLOGY AND PRINCIPAL FINDINGS: We employed video-telemetry to analyze 39 motor OCD rituals and compared each with a similar task performed by a non-OCD individual, in order to objectively and explicitly determine the functional end of the activity. We found that 75% of OCD rituals comprised a "tail," which is a section that follows the functional end of the task that the patients ascribed to their activity. The other 25% tailless rituals comprised a relatively high number and higher rate of repetition of non-functional acts. Thus, in rituals with tail, incompleteness was manifested by the mere presence of the tail whereas in tailless rituals, incompleteness was manifested by the reduced functionality of the task due to an inflated execution and repetition of non-functional acts. CONCLUSIONS: The prevalence of activity after the functional end ("tail" and the elevated non-functionality in OCD motor rituals support the "lack of stop signal" theories as the underlying mechanism in OCD. Furthermore, the presence and content of the tail might have a therapeutic potential in cognitive-behavior therapy.

  15. Dynamic Task Allocation in Cooperative Robot Teams

    Directory of Open Access Journals (Sweden)

    Athanasios Tsalatsanis

    2010-02-01

    Full Text Available In this paper a dynamic task allocation and controller design methodology for cooperative robot teams is presented. Fuzzy logic based utility functions are derived to quantify each robot\\'s ability to perform a task. These utility functions are used to allocate tasks in real-time through a limited lookahead control methodology partially based on the basic principles of discrete event supervisory control theory. The proposed controller design methodology accommodates flexibility in task assignments, robot coordination, and tolerance to robot failures and repairs. Implementation details of the proposed methodology are demonstrated through a warehouse patrolling case study.

  16. Dynamic Task Allocation in Cooperative Robot Teams

    Directory of Open Access Journals (Sweden)

    Athanasios Tsalatsanis

    2009-12-01

    Full Text Available In this paper a dynamic task allocation and controller design methodology for cooperative robot teams is presented. Fuzzy logic based utility functions are derived to quantify each robot's ability to perform a task. These utility functions are used to allocate tasks in real-time through a limited lookahead control methodology partially based on the basic principles of discrete event supervisory control theory. The proposed controller design methodology accommodates flexibility in task assignments, robot coordination, and tolerance to robot failures and repairs. Implementation details of the proposed methodology are demonstrated through a warehouse patrolling case study.

  17. Task-related functional connectivity in autism spectrum conditions: an EEG study using wavelet transform coherence

    Directory of Open Access Journals (Sweden)

    Catarino Ana

    2013-01-01

    Full Text Available Abstract Background Autism Spectrum Conditions (ASC are a set of pervasive neurodevelopmental conditions characterized by a wide range of lifelong signs and symptoms. Recent explanatory models of autism propose abnormal neural connectivity and are supported by studies showing decreased interhemispheric coherence in individuals with ASC. The first aim of this study was to test the hypothesis of reduced interhemispheric coherence in ASC, and secondly to investigate specific effects of task performance on interhemispheric coherence in ASC. Methods We analyzed electroencephalography (EEG data from 15 participants with ASC and 15 typical controls, using Wavelet Transform Coherence (WTC to calculate interhemispheric coherence during face and chair matching tasks, for EEG frequencies from 5 to 40 Hz and during the first 400 ms post-stimulus onset. Results Results demonstrate a reduction of interhemispheric coherence in the ASC group, relative to the control group, in both tasks and for all electrode pairs studied. For both tasks, group differences were generally observed after around 150 ms and at frequencies lower than 13 Hz. Regarding within-group task comparisons, while the control group presented differences in interhemispheric coherence between faces and chairs tasks at various electrode pairs (FT7-FT8, TP7-TP8, P7-P8, such differences were only seen for one electrode pair in the ASC group (T7-T8. No significant differences in EEG power spectra were observed between groups. Conclusions Interhemispheric coherence is reduced in people with ASC, in a time and frequency specific manner, during visual perception and categorization of both social and inanimate stimuli and this reduction in coherence is widely dispersed across the brain. Results of within-group task comparisons may reflect an impairment in task differentiation in people with ASC relative to typically developing individuals. Overall, the results of this research support the value of WTC

  18. A Cross-Sectional and Follow-Up Functional MRI Study with a Working Memory Task in Adolescent Anorexia Nervosa

    Science.gov (United States)

    Castro-Fornieles, Josefina; Caldu, Xavier; Andres-Perpina, Susana; Lazaro, Luisa; Bargallo, Nuria; Falcon, Carles; Plana, Maria Teresa; Junque, Carme

    2010-01-01

    Structural and functional brain abnormalities have been described in anorexia nervosa (AN). The objective of this study was to examine whether there is abnormal regional brain activation during a working memory task not associated with any emotional stimuli in adolescent patients with anorexia and to detect possible changes after weight recovery.…

  19. Executive Functioning and Processing Speed in Age-Related Differences in Memory: Contribution of a Coding Task

    Science.gov (United States)

    Baudouin, Alexia; Clarys, David; Vanneste, Sandrine; Isingrini, Michel

    2009-01-01

    The aim of the present study was to examine executive dysfunctioning and decreased processing speed as potential mediators of age-related differences in episodic memory. We compared the performances of young and elderly adults in a free-recall task. Participants were also given tests to measure executive functions and perceptual processing speed…

  20. Do Participants Differ in Their Cognitive Abilities, Task Motivation, or Personality Characteristics as a Function of Time of Participation?

    Science.gov (United States)

    Robison, Matthew K.; Unsworth, Nash

    2016-01-01

    Four experiments tested the conventional wisdom in experimental psychology that participants who complete laboratory tasks systematically differ in their cognitive abilities, motivational levels, and personality characteristics as a function of the time at which they participate during an academic term. Across 4 experiments with over 2,900…

  1. A Cross-Sectional and Follow-Up Functional MRI Study with a Working Memory Task in Adolescent Anorexia Nervosa

    Science.gov (United States)

    Castro-Fornieles, Josefina; Caldu, Xavier; Andres-Perpina, Susana; Lazaro, Luisa; Bargallo, Nuria; Falcon, Carles; Plana, Maria Teresa; Junque, Carme

    2010-01-01

    Structural and functional brain abnormalities have been described in anorexia nervosa (AN). The objective of this study was to examine whether there is abnormal regional brain activation during a working memory task not associated with any emotional stimuli in adolescent patients with anorexia and to detect possible changes after weight recovery.…

  2. Graphical Tasks to Measure Upper Limb Function in Patients With Parkinson's Disease : Validity and Response to Dopaminergic Medication

    NARCIS (Netherlands)

    Smits, Esther J.; Tolonen, Antti J.; Cluitmans, Luc; van Gils, Mark; Zietsma, Rutger C.; Borgemeester, Robbert W. K.; van Laar, Teus; Maurits, Natasha M.

    2017-01-01

    The most widely used method to assess motor functioning in Parkinson's disease (PD) patients is the unified Parkinson's disease rating scale-III (UPDRS-III). The UPDRS-III has limited ability to detect subtle changes in motor symptoms. Alternatively, graphical tasks can be used to provide objective

  3. The Measurement of Executive Function at Age 3 Years: Psychometric Properties and Criterion Validity of a New Battery of Tasks

    Science.gov (United States)

    Willoughby, Michael T.; Blair, Clancy B.; Wirth, R. J.; Greenberg, Mark

    2010-01-01

    In this study, the authors examined the psychometric properties and criterion validity of a newly developed battery of tasks that were designed to assess executive function (EF) abilities in early childhood. The battery was included in the 36-month assessment of the Family Life Project (FLP), a prospective longitudinal study of 1,292 children…

  4. Functional MRI approach for assessing hemispheric predominance of regions activated by a phonological and a semantic task

    Energy Technology Data Exchange (ETDEWEB)

    Cousin, Emilie; Peyrin, Carole; Pichat, Cedric [Laboratoire de Psychologie et Neurocognition, UMR CNRS 5105, Universite Pierre Mendes-France, BP 47, 38040 Grenoble Cedex 09 (France); Lamalle, Laurent; Le Bas, Jean-Francois [Unite IRM, IFR1, CHU Grenoble (France); Baciu, Monica [Laboratoire de Psychologie et Neurocognition, UMR CNRS 5105, Universite Pierre Mendes-France, BP 47, 38040 Grenoble Cedex 09 (France)], E-mail: mbaciu@upmf-grenoble.fr

    2007-08-15

    This fMRI study performed in healthy subjects aimed at using a statistical approach in order to determine significant functional differences between hemispheres and to assess specialized regions activated during a phonological and during a semantic task. This approach ('flip' method and subsequent statistical analyses of the parameter estimates extracted from regions of interest) allows identifying: (a) hemispheric specialized regions for each language task [semantic (living categorization) and phonological (rhyme detection)] and (b) condition-specific regions with respect to paradigm conditions (task and control). Our results showed that the rhyme-specific task regions were the inferior frontal (sub-region of BA 44, 45) and left inferior parietal (BA 40, 39) lobules. Furthermore, within the inferior parietal lobule, the angular gyrus was specific to target (rhyming) items (related to successfully grapho-phonemic processing). The categorization-specific task regions were the left inferior frontal (sub-region of BA 44, 45) and superior temporal (BA 22) cortices. Furthermore, the superior temporal gyrus was related to non-target (non-living) items (correlated to task difficulty). The relatively new approach used in this study has the advantage of providing: (a) statistical significance of the hemispheric specialized regions for a given language task and (b) supplementary information in terms of paradigm condition-specificity of the activated regions. The results (standard hemispheric specialized regions for a semantic and for a phonological task) obtained in healthy subjects may constitute a basement for mapping language and assessing hemispheric predominance in epileptic patients before surgery and avoiding post-surgical impairments of language.

  5. The importance of object geometric properties for trajectory modeling of functional reach-to-grasp robotic therapy tasks - biomed 2009.

    Science.gov (United States)

    Nathan, Dominic; Jeutter, Dean C

    2009-01-01

    Reaching-to-grasp is essential for the performance of activities of daily living. Pathologies such as stroke, spinal cord injury, cerebral palsy, etc. limit individuals from being able to perform meaningful upper extremity movements, leading to a reduced quality of life. Robotic aided therapy is gaining prevalence as a rehabilitation tool because it can provide consistent and quantitative therapy. Such systems are dependent upon models to generate trajectories that dictate their movements. Time scaled polynomial techniques have been extensively used for robotic model development and trajectory generation. However, this approach is limited because it cannot support functional therapy tasks. This is largely due to the influence of cognitive complexity not completely considered with regards to the activity performed. We examine the influence of task cognitive complexity as manifested through the geometric properties of each object on the movement trajectories and kinematic dependent variables tasks through a motion analysis study using healthy subjects (N=8). We then compare the predicted results from several robotic trajectory models with the actual motion analysis data. Our results show that there are differences present, between the trajectory data and kinematic properties for each task, that are specific to the geometric properties of each object. In addition, the predicted results from the robotic trajectory models do not fully correlate with the actual movement information. This study is important as it will help provide some insight with regards to factors that need to be considered during the development of future robotic trajectory models and controllers for upper extremity functional rehabilitation tasks.

  6. Ion velocity distribution functions in argon and helium discharges: detailed comparison of numerical simulation results and experimental data

    Science.gov (United States)

    Wang, Huihui; Sukhomlinov, Vladimir S.; Kaganovich, Igor D.; Mustafaev, Alexander S.

    2017-02-01

    Using the Monte Carlo collision method, we have performed simulations of ion velocity distribution functions (IVDF) taking into account both elastic collisions and charge exchange collisions of ions with atoms in uniform electric fields for argon and helium background gases. The simulation results are verified by comparison with the experiment data of the ion mobilities and the ion transverse diffusion coefficients in argon and helium. The recently published experimental data for the first seven coefficients of the Legendre polynomial expansion of the ion energy and angular distribution functions are used to validate simulation results for IVDF. Good agreement between measured and simulated IVDFs shows that the developed simulation model can be used for accurate calculations of IVDFs.

  7. Social attention in a virtual public speaking task in higher functioning children with autism.

    Science.gov (United States)

    Jarrold, William; Mundy, Peter; Gwaltney, Mary; Bailenson, Jeremy; Hatt, Naomi; McIntyre, Nancy; Kim, Kwanguk; Solomon, Marjorie; Novotny, Stephanie; Swain, Lindsay

    2013-10-01

    Impairments in social attention play a major role in autism, but little is known about their role in development after preschool. In this study, a public speaking task was used to study social attention, its moderators, and its association with classroom learning in elementary and secondary students with higher functioning autism spectrum disorder (HFASD). Thirty-seven students with HFASD and 54 age- and intelligence quotient (IQ)-matched peers without symptoms of ASD were assessed in a virtual classroom public speaking paradigm. This paradigm assessed the ability to attend to nine avatar peers seated at a table, while simultaneously answering self-referenced questions. Students with HFASD looked less frequently to avatar peers in the classroom while talking. However, social attention was moderated in the HFASD sample such that students with lower IQ, and/or more symptoms of social anxiety, and/or more attention deficit/hyperactivity disorder inattentive symptoms, displayed more atypical social attention. Group differences were more pronounced when the classroom contained social avatars versus nonsocial targets. Moreover, measures of social attention rather than nonsocial attention were significantly associated with parent report and objective measures of learning in the classroom. The data in this study support the hypothesis of the Social Attention Model of ASD that social attention disturbance remains part of the school-aged phenotype of autism that is related to syndrome-specific problems in social learning. More research of this kind would likely contribute to advances in the understanding of the development of the spectrum of autism and educational intervention approaches for affected school-aged children.

  8. Conducted electrical weapon incapacitation during a goal-directed task as a function of probe spread.

    Science.gov (United States)

    Ho, Jeffrey; Dawes, Donald; Miner, James; Kunz, Sebastian; Nelson, Rebecca; Sweeney, James

    2012-12-01

    Despite training and field experience that the location and spread between conducted electrical weapon (CEW) probes is important in establishing incapacitation, there have been no human studies which have systematically examined the relationships between probe spread and incapacitation. We have investigated this relationship with the TASER(®) X26. We have also developed and validated methodologies for prospective assessment of the effectiveness of CEWs in the incapacitation of highly motivated human subjects. Subjects (n = 30) had probes placed on the front or back with randomly varied spreads in accordance with recommended targeting zones. Subjects were motivated to complete the task of disabling the device or a dummy officer suspended ten feet away during the exposure while using a training knife. Subjects were rated on their progress toward goal success and on the extent of any incapacitation using two separate observer scoring panels: one consisting of experts in physiology and X26 technology, and another of veteran peace officers. Incapacitation by all measures was found to be a function of spread; generally increasing in effectiveness up to spreads between 9 and 12 in. There were notable differences between front and back exposures, with front exposures not leading to full incapacitation of the upper extremities regardless of probe spread. This is the first published study on a quantitative methodology for directly assessing the effectiveness of CEWs in human incapacitation. We have also validated and quantified for the first time in human subjects that establishing a minimal spread between X26 probes correlates to the extent of device effectiveness.

  9. Social Attention in a Virtual Public Speaking Task in Higher Functioning Children with Autism

    Science.gov (United States)

    Jarrold, William; Mundy, Peter; Gwaltney, Mary; Bailenson, Jeremy; Hatt, Naomi; McIntyre, Nancy; Kim, Kwanguk; Solomon, Marjorie; Novotny, Stephanie; Swain, Lindsay

    2013-01-01

    Background Impairments in social attention play a major role in autism, but little is known about their role in development after preschool. In this study a public speaking task was used to study social attention, its moderators, and its association with classroom learning in elementary and secondary students with higher functioning Autism Spectrum Disorder (HFASD). Method Thirty-seven students with HFASD and 54 age and IQ-matched peers without symptoms of ASD were assessed in a virtual classroom public speaking paradigm. This paradigm assessed the ability to attend to 9 avatar peers seated at a table, while simultaneously answering self-referenced questions. Results Students with HFASD looked less frequently to avatar peers in the classroom while talking. However, social attention was moderated in the HFASD sample such that students with lower IQ, and/or more symptoms of social anxiety, and/or more ADHD Inattentive symptoms, displayed more atypical social attention. Group differences were more pronounced when the classroom contained social avatars versus non-social targets. Moreover, measures of social attention rather than non-social attention were significantly associated with parent report and objective measures of learning in the classroom. Conclusions The data in this study supports the hypothesis of the Social Attention Model of ASD that social attention disturbance remains part of the school-aged phenotype of autism that is related to syndrome specific problems in social learning. More research of this kind would likely contribute to advances in the understanding of the development of autism and educational intervention approaches for affected school-aged children. PMID:23696132

  10. Functional Roles of Neural Preparatory Processes in a Cued Stroop Task Revealed by Linking Electrophysiology with Behavioral Performance.

    Directory of Open Access Journals (Sweden)

    Chao Wang

    Full Text Available It is well established that cuing facilitates behavioral performance and that different aspects of instructional cues evoke specific neural preparatory processes in cued task-switching paradigms. To deduce the functional role of these neural preparatory processes the majority of studies vary aspects of the experimental paradigm and describe how these variations alter markers of neural preparatory processes. Although these studies provide important insights, they also have notable limitations, particularly in terms of understanding the causal or functional relationship of neural markers to cognitive and behavioral processes. In this study, we sought to address these limitations and uncover the functional roles of neural processes by examining how variability in the amplitude of neural preparatory processes predicts behavioral performance to subsequent stimuli. To achieve this objective 16 young adults were recruited to perform a cued Stroop task while their brain activity was measured using high-density electroencephalography. Four temporally overlapping but functionally and topographically distinct cue-triggered event related potentials (ERPs were identified: 1 A left-frontotemporal negativity (250-700 ms that was positively associated with word-reading performance; 2 a midline-frontal negativity (450-800 ms that was positively associated with color-naming and incongruent performance; 3 a left-frontal negativity (450-800 ms that was positively associated with switch trial performance; and 4 a centroparietal positivity (450-800 ms that was positively associated with performance for almost all trial types. These results suggest that at least four dissociable cognitive processes are evoked by instructional cues in the present task, including: 1 domain-specific task facilitation; 2 switch-specific task-set reconfiguration; 3 preparation for response conflict; and 4 proactive attentional control. Examining the relationship between ERPs and behavioral

  11. A survey of molecular details in the human pineal gland in the light of phylogeny, structure, function and chronobiological diseases.

    Science.gov (United States)

    Stehle, Jörg H; Saade, Anastasia; Rawashdeh, Oliver; Ackermann, Katrin; Jilg, Antje; Sebestény, Tamás; Maronde, Erik

    2011-08-01

    The human pineal gland is a neuroendocrine transducer that forms an integral part of the brain. Through the nocturnally elevated synthesis and release of the neurohormone melatonin, the pineal gland encodes and disseminates information on circadian time, thus coupling the outside world to the biochemical and physiological internal demands of the body. Approaches to better understand molecular details behind the rhythmic signalling in the human pineal gland are limited but implicitly warranted, as human chronobiological dysfunctions are often associated with alterations in melatonin synthesis. Current knowledge on melatonin synthesis in the human pineal gland is based on minimally invasive analyses, and by the comparison of signalling events between different vertebrate species, with emphasis put on data acquired in sheep and other primates. Together with investigations using autoptic pineal tissue, a remnant silhouette of premortem dynamics within the hormone's biosynthesis pathway can be constructed. The detected biochemical scenario behind the generation of dynamics in melatonin synthesis positions the human pineal gland surprisingly isolated. In this neuroendocrine brain structure, protein-protein interactions and nucleo-cytoplasmic protein shuttling indicate furthermore a novel twist in the molecular dynamics in the cells of this neuroendocrine brain structure. These findings have to be seen in the light that an impaired melatonin synthesis is observed in elderly and/or demented patients, in individuals affected by Alzheimer's disease, Smith-Magenis syndrome, autism spectrum disorder and sleep phase disorders. Already, recent advances in understanding signalling dynamics in the human pineal gland have significantly helped to counteract chronobiological dysfunctions through a proper restoration of the nocturnal melatonin surge.

  12. Adolescents' performance on delay and probability discounting tasks: contributions of age, intelligence, executive functioning, and self-reported externalizing behavior.

    Science.gov (United States)

    Olson, Elizabeth A; Hooper, Catalina J; Collins, Paul; Luciana, Monica

    2007-11-01

    Healthy adolescents, ages 9-23, completed delay and probability discounting tasks and measures of verbal and nonverbal intelligence, executive functioning, and self-reported internalizing and externalizing behavior. Delay but not probability discounting decreased with age. Delay discounting was also associated with verbal intelligence and Go-NoGo and Iowa Gambling Task performance. Probability discounting was associated only with externalizing behavior. Findings conform to an accumulation of evidence that while delay and probability discounting may have some overlapping components, they also reflect some fundamentally different processes in this age group.

  13. Functional mutagenesis screens reveal the ‘cap structure’ formation in disulfide-bridge free TASK channels

    Science.gov (United States)

    Goldstein, Matthias; Rinné, Susanne; Kiper, Aytug K.; Ramírez, David; Netter, Michael F.; Bustos, Daniel; Ortiz-Bonnin, Beatriz; González, Wendy; Decher, Niels

    2016-01-01

    Two-pore-domain potassium (K2P) channels have a large extracellular cap structure formed by two M1-P1 linkers, containing a cysteine for dimerization. However, this cysteine is not present in the TASK-1/3/5 subfamily. The functional role of the cap is poorly understood and it remained unclear whether K2P channels assemble in the domain-swapped orientation or not. Functional alanine-mutagenesis screens of TASK-1 and TRAAK were used to build an in silico model of the TASK-1 cap. According to our data the cap structure of disulfide-bridge free TASK channels is similar to that of other K2P channels and is most likely assembled in the domain-swapped orientation. As the conserved cysteine is not essential for functional expression of all K2P channels tested, we propose that hydrophobic residues at the inner leaflets of the cap domains can interact with each other and that this way of stabilizing the cap is most likely conserved among K2P channels. PMID:26794006

  14. Computational models of upper-limb motion during functional reaching tasks for application in FES-based stroke rehabilitation.

    Science.gov (United States)

    Freeman, Chris; Exell, Tim; Meadmore, Katie; Hallewell, Emma; Hughes, Ann-Marie

    2015-06-01

    Functional electrical stimulation (FES) has been shown to be an effective approach to upper-limb stroke rehabilitation, where it is used to assist arm and shoulder motion. Model-based FES controllers have recently confirmed significant potential to improve accuracy of functional reaching tasks, but they typically require a reference trajectory to track. Few upper-limb FES control schemes embed a computational model of the task; however, this is critical to ensure the controller reinforces the intended movement with high accuracy. This paper derives computational motor control models of functional tasks that can be directly embedded in real-time FES control schemes, removing the need for a predefined reference trajectory. Dynamic models of the electrically stimulated arm are first derived, and constrained optimisation problems are formulated to encapsulate common activities of daily living. These are solved using iterative algorithms, and results are compared with kinematic data from 12 subjects and found to fit closely (mean fitting between 63.2% and 84.0%). The optimisation is performed iteratively using kinematic variables and hence can be transformed into an iterative learning control algorithm by replacing simulation signals with experimental data. The approach is therefore capable of controlling FES in real time to assist tasks in a manner corresponding to unimpaired natural movement. By ensuring that assistance is aligned with voluntary intention, the controller hence maximises the potential effectiveness of future stroke rehabilitation trials.

  15. Detailed analytical approach to the Gaussian surface bidirectional reflectance distribution function specular component applied to the sea surface.

    Science.gov (United States)

    Ross, Vincent; Dion, Denis; Potvin, Guy

    2005-11-01

    A statistical sea surface specular BRDF (bidirectional reflectance distribution function) model is developed that includes mutual shadowing by waves, wave facet hiding, and projection weighting. The integral form of the model is reduced to an analytical form by making minor and justifiable approximations. The new form of the BRDF thus allows one to compute sea reflected radiance more than 100 times faster than the traditional numerical solutions. The repercussions of the approximations used in the model are discussed. Using the analytical form of the BRDF, an analytical approximation is also obtained for the reflected sun radiance that is always good to within 1% of the numerical solution for sun elevations of more than 10 degrees above the horizon. The model is validated against measured sea radiances found in the literature and is shown to be in very good agreement.

  16. The Technologist Function in Fields Related to Radiology: Tasks in Radiation Therapy and Diagnostic Ultrasound. Research Report No. 9; Relating Technologist Tasks in Diagnostic Radiology, Ultrasound and Radiation Therapy. Research Report No. 10.

    Science.gov (United States)

    Gilpatrick, Eleanor

    The two research reports included in this document describe the application of the Health Services Mobility Study (HSMS) task analysis method to two technologist functions and examine the interrelationships of these tasks with those in diagnostic radiology. (The HSMS method includes processes for using the data for designing job ladders, for…

  17. The Technologist Function in Fields Related to Radiology: Tasks in Radiation Therapy and Diagnostic Ultrasound. Research Report No. 9; Relating Technologist Tasks in Diagnostic Radiology, Ultrasound and Radiation Therapy. Research Report No. 10.

    Science.gov (United States)

    Gilpatrick, Eleanor

    The two research reports included in this document describe the application of the Health Services Mobility Study (HSMS) task analysis method to two technologist functions and examine the interrelationships of these tasks with those in diagnostic radiology. (The HSMS method includes processes for using the data for designing job ladders, for…

  18. Functional MRI of tongue motor tasks in patients with tongue cancer: observations before and after partial glossectomy

    Energy Technology Data Exchange (ETDEWEB)

    Haupage, Samantha; Branski, Ryan C.; Kraus, Dennis [Memorial Sloan-Kettering Cancer Center, Head and Neck Surgery, New York, NY (United States); Peck, Kyung K. [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York, NY (United States); Memorial Sloan-Kettering Cancer Center, Medical Physics, New York, NY (United States); Memorial Sloan-Kettering Cancer Center, Department of Medical Physics and Radiology, New York, NY (United States); Hsu, Meier [Memorial Sloan-Kettering Cancer Center, Department of Epidemiology and Biostatistics, New York, NY (United States); Holodny, Andrei [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York, NY (United States)

    2010-12-15

    The current study seeks to provide preliminary data regarding this central, adaptive response during tongue motor tasks utilizing functional magnetic resonance imaging (fMRI) before and after glossectomy. Six patients, with confirmed histological diagnoses of oral tongue cancer, underwent fMRI before and 6 months after partial glossectomy. These data were compared to nine healthy controls. All subjects performed three tongue motor tasks during fMRI: tongue tapping (TT), dry swallow (Dry), and wet swallow (Wet). Following surgery, increased activation was subjectively observed in the superior parietal lobule, supplementary motor area, and anterior cingulate. Region of interest (ROI) analysis of the precentral gyrus confirmed increased cortical activity following surgery. In addition, comparisons between pre-surgical scans and controls suggested the dry swallow task was sensitive to elicit tongue-related activation in the precentral gyrus (p {<=} 0.05). The adaptive changes in the cortex following partial glossectomy reflect recruitment of the parietal, frontal, and cingulate cortex during tongue motor tasks. In addition, post-operative activation patterns more closely approximated control levels than the pre-operative scans. Furthermore, the dry swallow task appears most specific to elicit tongue-related cortical activity. (orig.)

  19. The implementation of the functional task exercise programme for elderly people living at home.

    Science.gov (United States)

    Fleuren, Margot A H; Vrijkotte, Susan; Jans, Marielle P; Pin, Renske; van Hespen, Ariette; van Meeteren, Nico L U; Siemonsma, Petra C

    2012-07-23

    The Functional Task Exercise programme is an evidence-based exercise programme for elderly people living at home. It enhances physical capacity with sustainable effects. FTE is provided by physiotherapists and remedial therapists. Although the intervention was found to be effective in a Randomised Controlled Trial, we may not assume that therapists will automatically supply the programme or that elderly people will automatically join the programme. This study protocol focuses on identifying determinants of implementation, developing implementation strategies and studying the effects of the implementation in daily practice. Phase 1: The systematic identification of determinants of the implementation of FTE among therapists and the elderly. A questionnaire study was conducted in a random sample of 100 therapists, and interviews took place with 23 therapists and 8 elderly people (aged 66 to 80 years). The determinants were broken down into four categories: the characteristics of the environment, the organisation, the therapists, and the training programme.Phase 2: Developing and applying strategies adapted to the determinants identified. Fifteen physiotherapists will be trained to provide FTE and to recruit elderly people living at home. The therapists will then deliver the 12-week programme to two groups of elderly, each consisting of six to twelve people aged 70 years or older.Phase 3: Study of implementation and the impact. To study the actual use of FTE: 1) therapists record information about the selection of participants and how they apply the key features of FTE, 2) the participating elderly will keep an exercise logbook, 3) telephone interviews will take place with the therapists and the elderly and there will be on-site visits. The effects on the elderly people will be studied using: 1) the Patient-Specific Questionnaire, the Timed Up and Go test and a two performance tests. All tests will be performed at the start of the FTE programme, half way through, and

  20. The implementation of the functional task exercise programme for elderly people living at home

    Directory of Open Access Journals (Sweden)

    Fleuren Margot A H

    2012-07-01

    Full Text Available Abstract Background The Functional Task Exercise programme is an evidence-based exercise programme for elderly people living at home. It enhances physical capacity with sustainable effects. FTE is provided by physiotherapists and remedial therapists. Although the intervention was found to be effective in a Randomised Controlled Trial, we may not assume that therapists will automatically supply the programme or that elderly people will automatically join the programme. This study protocol focuses on identifying determinants of implementation, developing implementation strategies and studying the effects of the implementation in daily practice. Methods/Design Phase 1: The systematic identification of determinants of the implementation of FTE among therapists and the elderly. A questionnaire study was conducted in a random sample of 100 therapists, and interviews took place with 23 therapists and 8 elderly people (aged 66 to 80 years. The determinants were broken down into four categories: the characteristics of the environment, the organisation, the therapists, and the training programme. Phase 2: Developing and applying strategies adapted to the determinants identified. Fifteen physiotherapists will be trained to provide FTE and to recruit elderly people living at home. The therapists will then deliver the 12-week programme to two groups of elderly, each consisting of six to twelve people aged 70 years or older. Phase 3: Study of implementation and the impact. To study the actual use of FTE: 1 therapists record information about the selection of participants and how they apply the key features of FTE, 2 the participating elderly will keep an exercise logbook, 3 telephone interviews will take place with the therapists and the elderly and there will be on-site visits. The effects on the elderly people will be studied using: 1 the Patient-Specific Questionnaire, the Timed Up and Go test and a two performance tests. All tests will be performed at

  1. Practice-related optimization and transfer of executive functions: a general review and a specific realization of their mechanisms in dual tasks.

    Science.gov (United States)

    Strobach, Tilo; Salminen, Tiina; Karbach, Julia; Schubert, Torsten

    2014-11-01

    Improvements in performing demanding and complex task situations are typically related to the optimization of executive functions and efficient behavioral control. The present study systematizes and reviews the optimization of different executive function types: Shifting, Inhibition, Updating, and Dual tasking. In particular, we focus on optimisations of these functions with training and on transfer effects of related training skills to non-trained situations. The aim of the study's empirical part (see also Appendix) was to investigate the specific mechanisms of executive functions in the context of Dual tasking, leading to improved dual-task performance after practice. More specifically, we tested the Efficient Task Instantiation (ETI) model that includes specific assumptions regarding practice-related improvements of executive task coordination skills: Dual-task performance is improved with practice because of an efficient and conjoint instantiation of sets of relevant task information in working memory at the onset of a dual task. According to our knowledge, the ETI model is one of the first that allows illustrating the contribution of cognitive mechanisms underlying practice-related improvements in performing dual tasks and the impact of task coordination skills on this performance.

  2. Higher burnout scores in paediatric residents are associated with increased brain activity during attentional functional magnetic resonance imaging task.

    Science.gov (United States)

    de Andrade, Anarella Penha Meirelles; Amaro, Edson; Farhat, Sylvia Costa Lima; Schvartsman, Claudio

    2016-06-01

    Burnout syndrome is common in healthcare workers. We evaluated its prevalence in paediatric residents and investigated its influence on cerebral function correlations, using functional magnetic resonance imaging (MRI), when they carried out an attentional paradigm. This cross-sectional descriptive study involved 28 residents from the Department of Paediatrics at the University of São Paulo. The functional MRI was carried out while the residents completed the Stroop colour word task paradigm to investigate their attentional task performance. The Maslach Burnout Inventory (MBI) was applied, and stress was assessed using the Lipp Inventory of Stress Symptoms for Adults and by a visual analogue mood scale. The MBI subscales of depersonalisation and emotional exhaustion indicated that 53.1% of the residents had moderate or high burnout syndrome. The whole-brain multivariate analysis showed positive correlations between the blood oxygenation level dependent effect and the MBI depersonalisation and emotional exhaustion indices in the dorsolateral prefrontal cortex, which controls for anxiety. Increased brain activation during an attention task, measured using functional MRI, was associated with higher burnout scores in paediatric residents. This study provides a biological basis for the implementation of measures to reduce burnout syndrome at the start of residency training programmes. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  3. Performance on naturalistic virtual reality tasks depends on global cognitive functioning as assessed via traditional neurocognitive tests.

    Science.gov (United States)

    Oliveira, Jorge; Gamito, Pedro; Alghazzawi, Daniyal M; Fardoun, Habib M; Rosa, Pedro J; Sousa, Tatiana; Picareli, Luís Felipe; Morais, Diogo; Lopes, Paulo

    2017-08-14

    This investigation sought to understand whether performance in naturalistic virtual reality tasks for cognitive assessment relates to the cognitive domains that are supposed to be measured. The Shoe Closet Test (SCT) was developed based on a simple visual search task involving attention skills, in which participants have to match each pair of shoes with the colors of the compartments in a virtual shoe closet. The interaction within the virtual environment was made using the Microsoft Kinect. The measures consisted of concurrent paper-and-pencil neurocognitive tests for global cognitive functioning, executive functions, attention, psychomotor ability, and the outcomes of the SCT. The results showed that the SCT correlated with global cognitive performance as measured with the Montreal Cognitive Assessment (MoCA). The SCT explained one third of the total variance of this test and revealed good sensitivity and specificity in discriminating scores below one standard deviation in this screening tool. These findings suggest that performance of such functional tasks involves a broad range of cognitive processes that are associated with global cognitive functioning and that may be difficult to isolate through paper-and-pencil neurocognitive tests.

  4. Characteristics and functions of entrepreneurship and some theoretic and methodological tasks of marketing

    Directory of Open Access Journals (Sweden)

    V.V. Lutsiak

    2014-06-01

    Full Text Available The aim of the article. Entrepreneurship is a sector of the market economic system that ensures satisfaction of social needs and fills the market with goods and services. The role of small business in the economic system of Ukraine is that this form of entrepreneurship is regarded as a factor that forms the competitive environment, which in its turn promotes a healthy market economy. Further development and elaboration of theoretical and methodological basics of small enterprises marketing activity requires constant attention with taking into consideration changes in the global market environment. The purpose of this research is the analysis of actual understanding of business, identification of main theoretical and methodological tasks aimed to ensure the effective functioning of enterprises in the context of marketing activity organization and realization. This paperwork resolves a number of issues in business content research and identifies the key targets of marketing activity of a company. The results of the analysis. The study was conducted with the use of system analysis elements, including historical and objective description of entrepreneurship as a factor of organizational basis of enterprise. This paperwork researches the genesis and the historical development of «entrepreneurship» as a substantive category. It also analyzes the basic characteristics that have been acquired by entrepreneurship in today's market environment. Entrepreneurship can be designated by following features: freedom, aspiration for success, risk, innovativeness, social responsibility, activity, initiative, social transformation. Activity, independence, aspiration for success and initiative of entrepreneurship are subject to the influence of political, legal and social-cultural environment. These circumstances cause the objective necessity of monitoring of the legislation that regulates business. The degree of risk in the entrepreneurship is associated with the

  5. Eye-Tracking as a Tool to Evaluate Functional Ability in Everyday Tasks in Glaucoma

    Science.gov (United States)

    Black, Alex A.

    2017-01-01

    To date, few studies have investigated the eye movement patterns of individuals with glaucoma while they undertake everyday tasks in real-world settings. While some of these studies have reported possible compensatory gaze patterns in those with glaucoma who demonstrated good task performance despite their visual field loss, little is known about the complex interaction between field loss and visual scanning strategies and the impact on task performance and, consequently, on quality of life. We review existing approaches that have quantified the effect of glaucomatous visual field defects on the ability to undertake everyday activities through the use of eye movement analysis. Furthermore, we discuss current developments in eye-tracking technology and the potential for combining eye-tracking with virtual reality and advanced analytical approaches. Recent technological developments suggest that systems based on eye-tracking have the potential to assist individuals with glaucomatous loss to maintain or even improve their performance on everyday tasks and hence enhance their long-term quality of life. We discuss novel approaches for studying the visual search behavior of individuals with glaucoma that have the potential to assist individuals with glaucoma, through the use of personalized programs that take into consideration the individual characteristics of their remaining visual field and visual search behavior. PMID:28293433

  6. Meaning-Based Scoring: A Systemic Functional Linguistics Model for Automated Test Tasks

    Science.gov (United States)

    Gleason, Jesse

    2014-01-01

    Communicative approaches to language teaching that emphasize the importance of speaking (e.g., task-based language teaching) require innovative and evidence-based means of assessing oral language. Nonetheless, research has yet to produce an adequate assessment model for oral language (Chun 2006; Downey et al. 2008). Limited by automatic speech…

  7. Priming in a free association task as a function of association directionality

    NARCIS (Netherlands)

    R. Zeelenberg; R.M. Shiffrin; J.G.W. Raaijmakers

    1999-01-01

    Two experiments investigated priming in free association, a conceptual implicit memory task. The stimuli consisted of bidirectionally associated word pairs (e.g., BEACH-SAND) and unidirectionally associated word pairs that have no association from the target response back to the stimulus cue (e.g.,

  8. Eye-Tracking as a Tool to Evaluate Functional Ability in Everyday Tasks in Glaucoma.

    Science.gov (United States)

    Kasneci, Enkelejda; Black, Alex A; Wood, Joanne M

    2017-01-01

    To date, few studies have investigated the eye movement patterns of individuals with glaucoma while they undertake everyday tasks in real-world settings. While some of these studies have reported possible compensatory gaze patterns in those with glaucoma who demonstrated good task performance despite their visual field loss, little is known about the complex interaction between field loss and visual scanning strategies and the impact on task performance and, consequently, on quality of life. We review existing approaches that have quantified the effect of glaucomatous visual field defects on the ability to undertake everyday activities through the use of eye movement analysis. Furthermore, we discuss current developments in eye-tracking technology and the potential for combining eye-tracking with virtual reality and advanced analytical approaches. Recent technological developments suggest that systems based on eye-tracking have the potential to assist individuals with glaucomatous loss to maintain or even improve their performance on everyday tasks and hence enhance their long-term quality of life. We discuss novel approaches for studying the visual search behavior of individuals with glaucoma that have the potential to assist individuals with glaucoma, through the use of personalized programs that take into consideration the individual characteristics of their remaining visual field and visual search behavior.

  9. Using Challenging Tasks for Formative Assessment on Quadratic Functions with Senior Secondary Students

    Science.gov (United States)

    Wilkie, Karina J.

    2016-01-01

    Senior secondary mathematics students who develop conceptual understanding that moves them beyond "rules without reasons" to connections between related concepts are in a strong place to tackle the more difficult mathematics application problems. Current research is examining how the use of challenging tasks at different levels of…

  10. Aberrant Behaviour of Persons with Developmental Disabilities as a Function of the Characteristics of Training Tasks.

    Science.gov (United States)

    Vause, Tricia; Martin, Garry L.; Yu, Dickie

    1999-01-01

    A study used the Assessment of Basic Learning Abilities to assess the abilities of three adults with mental retardation in order to reduce aberrant behavior. There was a higher frequency of aberrant responses during training sessions with training tasks above or below a participant's assessment level on the test. (Contains references.) (CR)

  11. Routization Problem Complicated by the Dependence of Costs Functions and «Current» Restrictions From the Tasks List

    Directory of Open Access Journals (Sweden)

    A. G Chentsov

    2016-01-01

    Full Text Available The problem of a routization of the movements complicated by the restrictions of different type (preceding conditions, the restrictions on the attainability of states by each movement and others is considered. A multivariance at the movement step is permitted, it is naturally resulted in the problem about the visiting of megalopolises. The costs of movements and jobs executed when visiting megalopolises may depend on the list of tacks. This list may correspond to performed or unperformed tasks. ”Current” restrictions (on movements may depend on the aforementioned list of tasks. The considered setting is oriented to the application with regard to a nuclear power engineering problems (the problem of decreasing irradiation of the nuclear power station staff when executing a complex of tasks under high radiation intensity and the machine building. In the second case, which consists in controling a machine for the sheet cutting of details by the numerical program control machines, ”current” restrictions on movements may be conditioned by temperature tolerance relative to the fragments of sheet which have already been ”visited” by the cutting machine. The scheme of constructing the optimal solution based on the widely understood dynamic programming is considered in this article. The used algorithm is realized on a personal computer; the results of its application are illustrated by the modelling examples.

  12. Investigating the effects of caffeine on executive functions using traditional Stroop and a new ecologically-valid virtual reality task, the Jansari assessment of Executive Functions (JEF©)

    OpenAIRE

    Soar, Kirstie; E. Chapman; Sivakuma, N.; Jansari, A.S.; Turner, John J.D.

    2016-01-01

    Objective: Caffeine has been shown to have effects on certain areas of cognition, but in\\ud executive functioning the research is limited and also inconsistent. One reason could be the\\ud need for a more sensitive measure to detect the effects of caffeine on executive function. This\\ud study used a new non-immersive virtual reality assessment of executive functions known as\\ud JEF© (the Jansari Assessment of Executive Function) alongside the ‘classic’ Stroop Colour-\\ud Word task to assess the...

  13. Job task and functional analysis of the Division of Reactor Projects, office of Nuclear Reactor Regulation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Morzinski, J.A.; Gilmore, W.; Hahn, H.A.

    1998-07-10

    A job task and functional analysis was recently completed for the positions that make up the regional Divisions of Reactor Projects. Among the conclusions of that analysis was a recommendation to clarify roles and responsibilities among site, regional, and headquarters personnel. As that analysis did not cover headquarters personnel, a similar analysis was undertaken of three headquarters positions within the Division of Reactor Projects: Licensing Assistants, Project Managers, and Project Directors. The goals of this analysis were to systematically evaluate the tasks performed by these headquarters personnel to determine job training requirements, to account for variations due to division/regional assignment or differences in several experience categories, and to determine how, and by which positions, certain functions are best performed. The results of this analysis include recommendations for training and for job design. Data to support this analysis was collected by a survey instrument and through several sets of focus group meetings with representatives from each position.

  14. Task-related BOLD responses and resting-state functional connectivity during physiological clamping of end-tidal CO(2).

    Science.gov (United States)

    Madjar, C; Gauthier, C J; Bellec, P; Birn, R M; Brooks, J C W; Hoge, R D

    2012-05-15

    Carbon dioxide (CO(2)), a potent vasodilator, is known to have a significant impact on the blood-oxygen level dependent (BOLD) signal. With the growing interest in studying synchronized BOLD fluctuations during the resting state, the extent to which the apparent synchrony is due to variations in the end-tidal pressure of CO(2) (PETCO(2)) is an important consideration. CO(2)-related fluctuations in BOLD signal may also represent a potential confound when studying task-related responses, especially if breathing depth and rate are affected by the task. While previous studies of the above issues have explored retrospective correction of BOLD fluctuations related to arterial PCO(2), here we demonstrate an alternative approach based on physiological clamping of the arterial CO(2) level to a near-constant value. We present data comparing resting-state functional connectivity within the default-mode-network (DMN), as well as task-related BOLD responses, acquired in two conditions in each subject: 1) while subject's PETCO(2) was allowed to vary spontaneously; and 2) while controlling subject's PETCO(2) within a narrow range. Strong task-related responses and areas of maximal signal correlation in the DMN were not significantly altered by suppressing fluctuations in PETCO(2). Controlling PETCO(2) did, however, improve the performance of retrospective physiological noise correction techniques, allowing detection of additional regions of task-related response and resting-state connectivity in highly vascularized regions such as occipital cortex. While these results serve to further rule out systemic physiological fluctuations as a significant source of apparent resting-state network connectivity, they also demonstrate that fluctuations in arterial CO(2) are one of the factors limiting sensitivity in task-based and resting-state fMRI, particularly in regions of high vascular density. This must be considered when comparing subject groups who might exhibit differences in

  15. No difference in frontal cortical activity during an executive functioning task after acute doses of aripiprazole and haloperidol

    Directory of Open Access Journals (Sweden)

    Ingeborg eBolstad

    2015-05-01

    Full Text Available Background: Aripiprazole is an atypical antipsychotic drug that is characterized by partial dopamine D2 receptor agonism. Its pharmacodynamic profile is proposed to be beneficial in the treatment of cognitive impairment, which is prevalent in psychotic disorders. This study compared brain activation characteristics produced by aripiprazole with that of haloperidol, a typical D2 receptor antagonist, during a task targeting executive functioning.Methods: Healthy participants received an acute oral dose of haloperidol, aripiprazole or placebo before performing an executive functioning task while blood-oxygen-level-dependent (BOLD functional magnetic resonance imaging (fMRI was carried out. Results: There was a tendency towards reduced performance in the aripiprazole group compared to the two other groups. The image analysis yielded a strong task-related BOLD-fMRI response within each group. An uncorrected between-group analysis showed that aripiprazole challenge resulted in stronger activation in the frontal and temporal gyri and the putamen compared with haloperidol challenge, but after correcting for multiple testing there was no significant group difference. Conclusion: No significant group differences between aripiprazole and haloperidol in frontal cortical activation were obtained when corrected for multiple comparisons.This study is registered in ClinicalTrials.gov (identifier: 2009-016222-14; https://clinicaltrials.gov/.

  16. Task-related functional connectivity of the caudate mediates the association between trait mindfulness and implicit learning in older adults.

    Science.gov (United States)

    Stillman, Chelsea M; You, Xiaozhen; Seaman, Kendra L; Vaidya, Chandan J; Howard, James H; Howard, Darlene V

    2016-08-01

    Accumulating evidence shows a positive relationship between mindfulness and explicit cognitive functioning, i.e., that which occurs with conscious intent and awareness. However, recent evidence suggests that there may be a negative relationship between mindfulness and implicit types of learning, or those that occur without conscious awareness or intent. Here we examined the neural mechanisms underlying the recently reported negative relationship between dispositional mindfulness and implicit probabilistic sequence learning in both younger and older adults. We tested the hypothesis that the relationship is mediated by communication, or functional connectivity, of brain regions once traditionally considered to be central to dissociable learning systems: the caudate, medial temporal lobe (MTL), and prefrontal cortex (PFC). We first replicated the negative relationship between mindfulness and implicit learning in a sample of healthy older adults (60-90 years old) who completed three event-related runs of an implicit sequence learning task. Then, using a seed-based connectivity approach, we identified task-related connectivity associated with individual differences in both learning and mindfulness. The main finding was that caudate-MTL connectivity (bilaterally) was positively correlated with learning and negatively correlated with mindfulness. Further, the strength of task-related connectivity between these regions mediated the negative relationship between mindfulness and learning. This pattern of results was limited to the older adults. Thus, at least in healthy older adults, the functional communication between two interactive learning-relevant systems can account for the relationship between mindfulness and implicit probabilistic sequence learning.

  17. Single-trial classification of motor imagery differing in task complexity: a functional near-infrared spectroscopy study

    Directory of Open Access Journals (Sweden)

    Wolf Martin

    2011-06-01

    Full Text Available Abstract Background For brain computer interfaces (BCIs, which may be valuable in neurorehabilitation, brain signals derived from mental activation can be monitored by non-invasive methods, such as functional near-infrared spectroscopy (fNIRS. Single-trial classification is important for this purpose and this was the aim of the presented study. In particular, we aimed to investigate a combined approach: 1 offline single-trial classification of brain signals derived from a novel wireless fNIRS instrument; 2 to use motor imagery (MI as mental task thereby discriminating between MI signals in response to different tasks complexities, i.e. simple and complex MI tasks. Methods 12 subjects were asked to imagine either a simple finger-tapping task using their right thumb or a complex sequential finger-tapping task using all fingers of their right hand. fNIRS was recorded over secondary motor areas of the contralateral hemisphere. Using Fisher's linear discriminant analysis (FLDA and cross validation, we selected for each subject a best-performing feature combination consisting of 1 one out of three channel, 2 an analysis time interval ranging from 5-15 s after stimulation onset and 3 up to four Δ[O2Hb] signal features (Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis. Results The results of our single-trial classification showed that using the simple combination set of channels, time intervals and up to four Δ[O2Hb] signal features comprising Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis, it was possible to discriminate single-trials of MI tasks differing in complexity, i.e. simple versus complex tasks (inter-task paired t-test p ≤ 0.001, over secondary motor areas with an average classification accuracy of 81%. Conclusions Although the classification accuracies look promising they are nevertheless subject of considerable subject-to-subject variability. In the discussion we address each of these aspects, their

  18. DETECTING BILATERAL FUNCTIONAL CONNECTIVITY IN THE PREFRONTAL CORTEX DURING A STROOP TASK BY NEAR-INFRARED SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    LEI ZHANG

    2013-10-01

    Full Text Available Near-infrared spectroscopy (NIRS is generally accepted as a functional brain imaging technology for brain activation study. With multichannel highly sensitive NIRS instruments, it has become possible to assess functional connectivity of different brain regions by NIRS. However, the feasibility needs to be validated in complex cognitive activities. In this study, we recorded the hemodynamic activity of the bilateral prefrontal cortex (PFC during a color-word matching Stroop task. Wavelet transform coherence (WTC analysis was applied to assess the functional connectivity of all homologous channel pairs within the left/right PFC. Both the behavioral and brain activation results showed significant Stroop effects. The results of WTC analysis revealed that, bilateral functional connectivity was significantly stronger during both the incongruent stimuli and neutral stimuli compared to that of the rest period. It also showed significant Stroop effect. Our findings demonstrate that, NIRS becomes a valuable tool to elucidate the functional connectivity of brain cortex in complex cognitive activities.

  19. Learning Effects on Strategy Selection in a Dynamic Task Environment as a Function of Time Pressure

    Science.gov (United States)

    1994-06-01

    MANAGEMENT UI1TREKSEL Previous research on strategy selection in dynamic task environments indicated that subjects preferred to request information first...I febwari 1994 is de naam Instituut voor Zintuigfysiologie TNO gewijzigd in TNO Technische Menskunde. 2 CONTENTS Page SUMMARY 3 SAMENVAITING 4 I...waarin men gebruik maakt van de continue feedback over de toestand van het systeem . Proefpersonen moesten het veranderende conditieniveau van een atleet

  20. Optimal work-rest cycles for an isometric intermittent gripping task as a function of force, posture and grip span.

    Science.gov (United States)

    Eksioglu, Mahmut

    2006-02-10

    The aim of this study was to investigate the maximum acceptable contraction frequencies (i.e. work-rest cycles) for an isometric-intermittent handgrip task as a function of grip span, applied force and shoulder posture using psychophysical and physiological approaches. Twelve healthy males served as subjects. The three grip spans investigated were the optimal, 2 cm narrower than the optimal, and 2 cm wider than the optimal. The grip force levels studied were 15% and 30% of maximum voluntary grip force and the two shoulder postures were 25 degrees flexion and 30 degrees abduction. The psychophysical results indicate that subjects work faster with the narrower grip span at 15% of maximum voluntary grip force level in comparison to working with the optimal and the wider spans. However, when the task required 30% of maximum grip force level, the subjects worked faster with the optimal grip span. These findings were supported by the results of electromyography, heart rate, blood pressure and perceived discomfort. The study suggests that grip span of a tool is an important factor to be considered in predicting optimal work-rest cycles for hand grip tasks, and the optimum setting of grip span of the hand-tool depends on the required task force level. That is, the optimality is relative rather than absolute. In addition, it appears that weaker subjects can work at a higher rate than stronger ones at the same relative force level.

  1. Language mapping in children using resting-state functional connectivity: comparison with a task-based approach

    Science.gov (United States)

    Gallagher, Anne; Tremblay, Julie; Vannasing, Phetsamone

    2016-12-01

    Patients with brain tumor or refractory epilepsy may be candidates for neurosurgery. Presurgical evaluation often includes language investigation to prevent or reduce the risk of postsurgical language deficits. Current techniques involve significant limitations with pediatric populations. Recently, near-infrared spectroscopy (NIRS) has been shown to be a valuable neuroimaging technique for language localization in children. However, it typically requires the child to perform a task (task-based NIRS), which may constitute a significant limitation. Resting-state functional connectivity NIRS (fcNIRS) is an approach that can be used to identify language networks at rest. This study aims to assess the utility of fcNIRS in children by comparing fcNIRS to more conventional task-based NIRS for language mapping in 33 healthy participants: 25 children (ages 3 to 16) and 8 adults. Data were acquired at rest and during a language task. Results show very good concordance between both approaches for language localization (Dice similarity coefficient=0.81±0.13) and hemispheric language dominance (kappa=0.86, p<0.006). The fcNIRS technique may be a valuable tool for language mapping in clinical populations, including children and patients with cognitive and behavioral impairments.

  2. Prefrontal responses to Stroop tasks in subjects with post-traumatic stress disorder assessed by functional near infrared spectroscopy

    Science.gov (United States)

    Yennu, Amarnath; Tian, Fenghua; Smith-Osborne, Alexa; J. Gatchel, Robert; Woon, Fu Lye; Liu, Hanli

    2016-07-01

    Studies on posttraumatic stress disorder (PTSD) showing attentional deficits have implicated abnormal activities in the frontal lobe. In this study, we utilized multichannel functional near-infrared spectroscopy (fNIRS) to investigate selective attention-related hemodynamic activity in the prefrontal cortex among 15 combat-exposed war-zone veterans with PTSD and 13 age- and gender-matched healthy controls. While performing the incongruent Stroop task, healthy controls showed significant activations in the left lateral prefrontal cortex (LPFC) compared to baseline readings. This observation is consistent with previously reported results. In comparison, subjects with PTSD failed to activate left LPFC during the same Stroop task. Our observations may implicate that subjects with PTSD experienced difficulty in overcoming Stroop interference. We also observed significant negative correlation between task reaction times and hemodynamic responses from left LPFC during the incongruent Stroop task in the PTSD group. Regarding the methodology used in this study, we have learned that an appropriate design of Stroop paradigms is important for meeting an optimal cognitive load which can lead to better brain image contrasts in response to Stroop interference between healthy versus PTSD subjects. Overall, the feasibility of fNIRS for studying and mapping neural correlates of selective attention and interference in subjects with PTSD is reported.

  3. Perceptual-cognitive skills and their interaction as a function of task constraints in soccer.

    Science.gov (United States)

    Roca, André; Ford, Paul R; McRobert, Allistair P; Williams, A Mark

    2013-04-01

    The ability to anticipate and to make decisions is crucial to skilled performance in many sports. We examined the role of and interaction between the different perceptual-cognitive skills underlying anticipation and decision making. Skilled and less skilled players interacted as defenders with life-size film sequences of 11 versus 11 soccer situations. Participants were presented with task conditions in which the ball was located in the offensive or defensive half of the pitch (far vs. near conditions). Participants' eye movements and verbal reports of thinking were recorded across two experiments. Skilled players reported more accurate anticipation and decision making than less skilled players, with their superior performance being underpinned by differences in task-specific search behaviors and thought processes. The perceptual-cognitive skills underpinning superior anticipation and decision making were shown to differ in importance across the two task constraints. Findings have significant implications for those interested in capturing and enhancing perceptual-cognitive skill in sport and other domains.

  4. Discuss the Making Details of Functional Food Advertising Review Regula-tions%保健食品广告审查法规制定细节探讨

    Institute of Scientific and Technical Information of China (English)

    富晓楠; 李松波; 王姝; 张颖

    2015-01-01

    Objective Promoting the sound development of functional food advertising market and providing reference for propos-ing functional food advertising review regulations. Methods Discussing the current problems of functional food advertising review regulations in our country and putting forward some countermeasures and suggestions for them through analyzing the current status of functional food advertising. Conclusion The current functional food advertising review regulations of our country has been un-able to adapt to the development of functional food advertising market. Through analyzing and discussing the revision details of functional food advertising relevant review regulations, promoting the amendment of functional food advertising review regulations, advancing the healthy development of functional food advertising market, and correctly guiding the consumers to buy functional food.%目的:促进保健食品广告市场良性发展,为拟制定保健食品广告审查相关法规提供借鉴。方法通过分析我国保健食品广告情况,得出目前我国食品保健广告审查中出现的问题,为保健食品广告审查法规更加完整提出建议和对策。结论当前我国保健食品广告审查法规已无法适应保健食品广告市场发展速度,通过分析探讨一些存在于修订保健食品广告的相关细节,促进整个过程的的不断完善,使保健食品广告也步入健康发展的轨道,引导消费者采购安全保健食品。

  5. Functional interaction between right parietal and bilateral frontal cortices during visual search tasks revealed using functional magnetic imaging and transcranial direct current stimulation.

    Directory of Open Access Journals (Sweden)

    Amanda Ellison

    Full Text Available The existence of a network of brain regions which are activated when one undertakes a difficult visual search task is well established. Two primary nodes on this network are right posterior parietal cortex (rPPC and right frontal eye fields. Both have been shown to be involved in the orientation of attention, but the contingency that the activity of one of these areas has on the other is less clear. We sought to investigate this question by using transcranial direct current stimulation (tDCS to selectively decrease activity in rPPC and then asking participants to perform a visual search task whilst undergoing functional magnetic resonance imaging. Comparison with a condition in which sham tDCS was applied revealed that cathodal tDCS over rPPC causes a selective bilateral decrease in frontal activity when performing a visual search task. This result demonstrates for the first time that premotor regions within the frontal lobe and rPPC are not only necessary to carry out a visual search task, but that they work together to bring about normal function.

  6. Selection of Mother Wavelet Functions for Multi-Channel EEG Signal Analysis during a Working Memory Task

    Directory of Open Access Journals (Sweden)

    Noor Kamal Al-Qazzaz

    2015-11-01

    Full Text Available We performed a comparative study to select the efficient mother wavelet (MWT basis functions that optimally represent the signal characteristics of the electrical activity of the human brain during a working memory (WM task recorded through electro-encephalography (EEG. Nineteen EEG electrodes were placed on the scalp following the 10–20 system. These electrodes were then grouped into five recording regions corresponding to the scalp area of the cerebral cortex. Sixty-second WM task data were recorded from ten control subjects. Forty-five MWT basis functions from orthogonal families were investigated. These functions included Daubechies (db1–db20, Symlets (sym1–sym20, and Coiflets (coif1–coif5. Using ANOVA, we determined the MWT basis functions with the most significant differences in the ability of the five scalp regions to maximize their cross-correlation with the EEG signals. The best results were obtained using “sym9” across the five scalp regions. Therefore, the most compatible MWT with the EEG signals should be selected to achieve wavelet denoising, decomposition, reconstruction, and sub-band feature extraction. This study provides a reference of the selection of efficient MWT basis functions.

  7. Main: Clone Detail [KOME

    Lifescience Database Archive (English)

    Full Text Available Clone Detail Mapping Pseudomolecule data detail Detail information Mapping to the TIGR japonica Pseudomolecu...les kome_mapping_pseudomolecule_data_detail.zip kome_mapping_pseudomolecule_data_detail ...

  8. Shoulder physical activity, functional disability and task difficulties in patients with stiff shoulders: interpretation from RT3 accelerator.

    Science.gov (United States)

    Yang, Jing-Lan; Lin, Jiu-Jenq; Huang, Han-Yi; Huang, Tsun-Shun; Chao, Yu Wen

    2014-08-01

    We determined whether the degree of symptom-related functional disability was related to daily physical activity of the shoulder in subjects with stiff shoulders (SSs). Responsiveness and a clinically meaningful level of discrimination between improvement and non-improvement for shoulder physical activity (SPA) were determined. Twenty-six subjects with SSs participated. Shoulder physical activity was assessed by RT3 accelerometers fixed on the humerus during daily 14-h data collection periods twice a week for 2 weeks. A moderate correlation coefficient was found between SPA and functional disability (β = .47). Based on our cohort design and sample, we suggest that SPA (higher than 101.8 counts, hard-moderate or hard tasks) during daily activity are associated with (with at least 83% probability) non-improvement in an individual with SS. Compared to the non-improvement group, the improvement group had less duration of sedentary activity, less frequency and duration of hard tasks, and more frequency and duration of easy tasks (p physical activities for subjects with SS is important to consider in rehabilitation strategies for these subjects. In our sample, a hard level of shoulder physical activity and sedentary activity should be cautious for these subjects. Further study is needed to validate therapeutic effect of physical activity on the course of patient improvement in subjects with SSs.

  9. Internal consistency and test-retest reliability of an instrumented functional reaching task using wireless electromyographic sensors.

    Science.gov (United States)

    Varghese, Rini; Hui-Chan, Christina W Y; Wang, Edward; Bhatt, Tanvi

    2014-10-01

    The purpose of this study was to establish the internal consistency and test-retest reliability of the electromyographic and accelerometric data sampled from the prime movers of the dominant arm during an antigravity, within-arm's length stand-reaching task without trunk restraint. Ten healthy young adults participated in two experimental sessions, approximately 7-10days apart. During each session, subjects performed 15 trials of both a flexion- and an abduction-reaching task. Surface EMG and acceleration using wireless sensors were sampled from the anterior and middle deltoid. Reliability was established using Cronbach's alpha, intraclass correlation coefficients (ICC 2, k) and standard error of measurements (SEM) for electromyographic reaction time, burst duration and normalized amplitude along with peak acceleration. Results indicated high degrees of inter-trial and test-retest reliability for flexion (Cronbach's α range=0.92-0.99; ICC range=0.82-0.92) as well as abduction (Cronbach's α range=0.94-0.99; ICC range=0.81-0.94) reaching. The SEM associated with response variables for flexion and abduction ranged from 1.55-3.26% and 3.33-3.95% of means, respectively. Findings from this study revealed that electromyographic and accelerometric data collected from prime movers of the arm during the relatively functional stand-reaching task were highly reproducible. Given its high reliability and portability, the proposed test could have applications in clinical and laboratory settings to quantify upper limb function.

  10. Long-range functional interactions of anterior insula and medial frontal cortex are differently modulated by visuospatial and inductive reasoning tasks.

    Science.gov (United States)

    Ebisch, Sjoerd J H; Mantini, Dante; Romanelli, Roberta; Tommasi, Marco; Perrucci, Mauro G; Romani, Gian Luca; Colom, Roberto; Saggino, Aristide

    2013-09-01

    The brain is organized into functionally specific networks as characterized by intrinsic functional relationships within discrete sets of brain regions. However, it is poorly understood whether such functional networks are dynamically organized according to specific task-states. The anterior insular cortex (aIC)-dorsal anterior cingulate cortex (dACC)/medial frontal cortex (mFC) network has been proposed to play a central role in human cognitive abilities. The present functional magnetic resonance imaging (fMRI) study aimed at testing whether functional interactions of the aIC-dACC/mFC network in terms of temporally correlated patterns of neural activity across brain regions are dynamically modulated by transitory, ongoing task demands. For this purpose, functional interactions of the aIC-dACC/mFC network are compared during two distinguishable fluid reasoning tasks, Visualization and Induction. The results show an increased functional coupling of bilateral aIC with visual cortices in the occipital lobe during the Visualization task, whereas coupling of mFC with right anterior frontal cortex was enhanced during the Induction task. These task-specific modulations of functional interactions likely reflect ability related neural processing. Furthermore, functional connectivity strength between right aIC and right dACC/mFC reliably predicts general task performance. The findings suggest that the analysis of long-range functional interactions may provide complementary information about brain-behavior relationships. On the basis of our results, it is proposed that the aIC-dACC/mFC network contributes to the integration of task-common and task-specific information based on its within-network as well as its between-network dynamic functional interactions.

  11. Advanced Integrated Multi-sensor Surveillance (AIMS). Mission, Function, Task Analysis

    Science.gov (United States)

    2007-06-01

    were developed under contract to CAE Professional Services (PS) (formerly Greenley and Associates Inc.). As part of the design process, a detailed...professionnels (nouvelle appellation de Greenley and Associates Inc.). Dans le cadre de la conception, une analyse détaillée de missions, de fonctions et de...between technological capability and operator performance. CAE Professional Services (PS) (formerly Greenley and Associates Inc.) has been

  12. Executive functioning in preschoolers: reducing the inhibitory demands of the dimensional change card sort task.

    Science.gov (United States)

    Rennie, David A C; Bull, Rebecca; Diamond, Adele

    2004-01-01

    To investigate the role of inhibitory control in preschoolers' ability to switch sets, 3 conditions of the Dimensional Change Card Sort task ( Zelazo, Reznick, & Pinon, 1995) were tested. In Condition B (novel response options, standard stimuli) action inhibition was reduced, but the need for attentional inhibition was maintained. In Condition C (novel stimuli, standard response options) demands on both action and attentional inhibition were reduced. Performance in these was compared to that in the standard condition (A). Rule complexity was comparable across conditions. All 21 children who passed preswitch (average age 37 months) were tested on all postswitch conditions, order counterbalanced. Although reducing demands on action inhibition (Condition B) did not significantly improve performance, when demands on both action and attentional inhibition were reduced (Condition C) almost all children (95%) successfully switched sets (even children only 2 1/2 years old). Inadequate inhibition (of attention alone or both attention and action) appears sufficient to account for virtually all errors by preschoolers on this card sorting task.

  13. Task-based mirror therapy enhances ipsilesional motor functions in stroke: A pilot study.

    Science.gov (United States)

    Arya, Kamal Narayan; Pandian, Shanta; Kumar, Dharmendra

    2017-04-01

    To examine the effect of Mirror therapy (MT) on dexterity, coordination, and muscle strength of the less-affected upper limb in stroke. Pre-test post-test, single group, experimental design. Rehabilitation institute. Post-stroke hemiparetic chronic subjects (N = 21). Forty sessions of MT using various tasks in addition to the conventional rehabilitation. Tasks such as lifting a glass, ball-squeezing, and picking-up objects were performed by the less-affected side in front of the mirror-box creating an illusion for the affected side. Minnesota Manual Dexterity Test (MMDT), Purdue Peg Board Test (PPBT), and Manual Muscle Testing (MMT) were used to measure the deficits of the less-affected side. Post-intervention, the less-affected side of the participants exhibited significant improvement on MMDT (p < 0.001), PPBT (p < 0.001), and MMT (shoulder flexors, wrist extensors and deviators, and finger flexors-extensors; p = 0.005-0.046). In post-stroke hemiparesis, MT also led to the improvement in dexterity, coordination, and strength of the less-affected side. In addition to the affected side, the technique may augment the subtle motor deficits of the less-affected side. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Comparing the fixational and functional preferred retinal location in a pointing task.

    Science.gov (United States)

    Sullivan, Brian; Walker, Laura

    2015-11-01

    Patients with central vision loss (CVL) typically adopt eccentric viewing strategies using a preferred retinal locus (PRL) in peripheral retina. Clinically, the PRL is defined monocularly as the area of peripheral retina used to fixate small stimuli. It is not clear if this fixational PRL describes the same portion of peripheral retina used during dynamic binocular eye-hand coordination tasks. We studied this question with four participants each with a unique CVL history. Using a scanning laser ophthalmoscope, we measured participants' monocular visual fields and the location and stability of their fixational PRLs. Participants' monocular and binocular visual fields were also evaluated using a computer monitor and eye tracker. Lastly, eye-hand coordination was tested over several trials where participants pointed to and touched a small target on a touchscreen monitor. Trials were blocked and carried out monocularly and binocularly, with a target appearing at 5° or 15° from screen center, in one of 8 locations. During pointing, our participants often exhibited long movement durations, an increased number of eye movements and impaired accuracy, especially in monocular conditions. However, these compensatory changes in behavior did not consistently worsen when loci beyond the fixational PRL were used. While fixational PRL size, location and fixation stability provide a necessary description of behavior, they are not sufficient to capture the pointing PRL used in this task. Generally, patients use a larger portion of peripheral retina than one might expect from measures of the fixational PRL alone, when pointing to a salient target without time constraints. While the fixational and pointing PRLs often overlap, the fixational PRL does not predict the large area of peripheral retina that can be used.

  15. A real-life, ecologically valid test of executive functioning : The executive secretarial task

    NARCIS (Netherlands)

    Lamberts, Kirsten F.; Evans, Jonathan J.; Spikman, Jacoba M.

    2010-01-01

    A major goal of neuropsychological assessment is predicting a person's level of functioning in daily life. Making predictions about everyday executive functioning based on tests is problematic because of the contrast between demands made in the test environment and demands made in everyday life (Sha

  16. Functional Near-Infrared Spectroscopy for the Assessment of Speech Related Tasks

    Science.gov (United States)

    Dieler, A. C.; Tupak, S. V.; Fallgatter, A. J.

    2012-01-01

    Over the past years functional near-infrared spectroscopy (fNIRS) has substantially contributed to the understanding of language and its neural correlates. In contrast to other imaging techniques, fNIRS is well suited to study language function in healthy and psychiatric populations due to its cheap and easy application in a quiet and natural…

  17. Functional Near-Infrared Spectroscopy for the Assessment of Speech Related Tasks

    Science.gov (United States)

    Dieler, A. C.; Tupak, S. V.; Fallgatter, A. J.

    2012-01-01

    Over the past years functional near-infrared spectroscopy (fNIRS) has substantially contributed to the understanding of language and its neural correlates. In contrast to other imaging techniques, fNIRS is well suited to study language function in healthy and psychiatric populations due to its cheap and easy application in a quiet and natural…

  18. A Preliminary Study of Functional Brain Activation among Marijuana Users during Performance of a Virtual Water Maze Task

    Directory of Open Access Journals (Sweden)

    Jennifer Tropp Sneider

    2013-01-01

    Full Text Available Numerous studies have reported neurocognitive impairments associated with chronic marijuana use. Given that the hippocampus contains a high density of cannabinoid receptors, hippocampal-mediated cognitive functions, including visuospatial memory, may have increased vulnerability to chronic marijuana use. Thus, the current study examined brain activation during the performance of a virtual analogue of the classic Morris water maze task in 10 chronic marijuana (MJ users compared to 18 nonusing (NU comparison subjects. Imaging data were acquired using blood oxygen level-dependent (BOLD functional MRI at 3.0 Tesla during retrieval (hidden platform and motor control (visible platform conditions. While task performance on learning trials was similar between groups, MJ users demonstrated a deficit in memory retrieval. For BOLD fMRI data, NU subjects exhibited greater activation in the right parahippocampal gyrus and cingulate gyrus compared to the MJ group for the Retrieval-Motor Control contrast (NU > MJ. These findings suggest that hypoactivation in MJ users may be due to differences in the efficient utilization of neuronal resources during the retrieval of memory. Given the paucity of data on visuospatial memory function in MJ users, these findings may help elucidate the neurobiological effects of marijuana on brain activation during memory retrieval.

  19. On the Interpretation of Response Time vs Onset Asynchrony Functions: Application to Dual-Task and Precue-Utilization Paradigms.

    Science.gov (United States)

    Schwarz, Wolfgang; Ischebeck, Anja

    2001-06-01

    The central bottleneck model of dual-task performance (H. Pashler and J. C. Johnston, 1998, Quarterly Journal of Experimental Psychology, 46A, 51-82) and the serial processing model of precue utilization (R. Gottsdanker, 1992, Acta Psychologica, 79, 21-43) are based on a common formal structure: They both represent response time as RT(tau)=max(X-tau, Y)+Z, where X, Y, Z denote the duration of certain processing stages specified by the models and tau denotes the onset asynchrony (SOA) between two stimuli. We consider this model within a stochastic framework in which the stage durations are random variables following an arbitrary joint distribution and derive properties of the function relating E[RT(tau)] to SOA. We present a distribution-free result which relates the slope of this function to the distribution of the random durations of the assumed processing stages. Our results allow for a direct, model-based interpretation of data from related experiments; specifically, they show how the slope of the SOA-function depends on experimental factors which selectively influence individual processing stages. We explain the implications of our results for models of dual-task performance and precue utilization and illustrate their application to data obtained by M. C. Smith (1969, Acta Psychologica, 30, 220-231) and R. Gottsdanker (1992, loc. cit.) Copyright 2001 Academic Press.

  20. Efficient and reversible CO2 capture by amine functionalized-silica gel confined task-specific ionic liquid system

    OpenAIRE

    Javad Aboudi; Majid Vafaeezadeh

    2015-01-01

    Simple, efficient and practical CO2 capture method is reported using task-specific ionic liquid (IL) supported onto the amine-functionalized silica gel. The results have been shown that both the capacity and rate of the CO2 absorption notably increase in the supported IL/molecular sieve 4 Å system in comparison of homogeneous IL. Additionally, it has shown that the prepared material is capable for reversible carbon dioxide absorption for at least 10 cycles without significant loss of efficien...

  1. The evolutionary function of conscious information processing is revealed by its task-dependency in the olfactory system.

    Science.gov (United States)

    Keller, Andreas

    2014-01-01

    Although many responses to odorous stimuli are mediated without olfactory information being consciously processed, some olfactory behaviors require conscious information processing. I will here contrast situations in which olfactory information is processed consciously to situations in which it is processed non-consciously. This contrastive analysis reveals that conscious information processing is required when an organism is faced with tasks in which there are many behavioral options available. I therefore propose that it is the evolutionary function of conscious information processing to guide behaviors in situations in which the organism has to choose between many possible responses.

  2. Executive function deficits in team sport athletes with a history of concussion revealed by a visual-auditory dual task paradigm.

    Science.gov (United States)

    Tapper, Anthony; Gonzalez, Dave; Roy, Eric; Niechwiej-Szwedo, Ewa

    2017-02-01

    The purpose of this study was to examine executive functions in team sport athletes with and without a history of concussion. Executive functions comprise many cognitive processes including, working memory, attention and multi-tasking. Past research has shown that concussions cause difficulties in vestibular-visual and vestibular-auditory dual-tasking, however, visual-auditory tasks have been examined rarely. Twenty-nine intercollegiate varsity ice hockey athletes (age = 19.13, SD = 1.56; 15 females) performed an experimental dual-task paradigm that required simultaneously processing visual and auditory information. A brief interview, event description and self-report questionnaires were used to assign participants to each group (concussion, no-concussion). Eighteen athletes had a history of concussion and 11 had no concussion history. The two tests involved visuospatial working memory (i.e., Corsi block test) and auditory tone discrimination. Participants completed both tasks individually, then simultaneously. Two outcome variables were measured, Corsi block memory span and auditory tone discrimination accuracy. No differences were shown when each task was performed alone; however, athletes with a history of concussion had a significantly worse performance on the tone discrimination task in the dual-task condition. In conclusion, long-term deficits in executive functions were associated with a prior history of concussion when cognitive resources were stressed. Evaluations of executive functions and divided attention appear to be helpful in discriminating participants with and without a history concussion.

  3. Detailed reconstruction of the functional state of the Central Yamal khasyrey as a response to local conditions and regional climate changes in the late Holocene

    Science.gov (United States)

    Preis, Yu I.; Simonova, G. V.; Slagoda, E. A.

    2016-11-01

    In this article, data of reconstruction of the dynamics of plant communities, water regimes, geocryological conditions, and peat accumulation of the khasyrey of Central Yamal Peninsula located in the tundra of Western Siberia by traditional paleoecological methods on the basis of detailed studies of the botanical composition, degree of decomposition, density, ash content and δ13C in the cellulose of peat cut pulp age about 1300 cal. BP are considered. It has been shown that the khasyrey has a sensitive response on century and decadal scales to climate change and the lake regime level. Moreover, the stages of khasyrey functional state are in a good agreement with similar data on mires of the forest zone of Western Siberia and the solar activity periods.

  4. Childhood trauma-related alterations in brain function during a Theory-of-Mind task in schizophrenia.

    Science.gov (United States)

    Quidé, Yann; Ong, Xin H; Mohnke, Sebastian; Schnell, Knut; Walter, Henrik; Carr, Vaughan J; Green, Melissa J

    2017-02-16

    Childhood trauma is a risk factor for schizophrenia that affects brain functions associated with higher cognitive processes, including social cognition. Alterations in Theory-of-Mind (ToM), or mentalizing skills, are a hallmark feature of schizophrenia, and are also evident in individuals exposed to childhood trauma. However, the impact of childhood trauma exposure on brain function during social cognition in schizophrenia remains unclear. We thus examined the association between childhood trauma and brain function during the performance of a ToM task in 47 patients diagnosed with schizophrenia or schizoaffective disorder. All participants completed the Childhood Trauma Questionnaire (CTQ) and underwent functional magnetic resonance imaging while performing an established visual-cartoon affective ToM task. Whole-brain multiple regression analysis was performed on ToM-related brain activation, with CTQ total score as regressor of interest, while accounting for the effects of age, sex, diagnosis, symptom severity, behavioural performance, intelligence and medications levels. First, using a small-volume correction approach within a mask made of key regions for ToM [including bilateral temporo-parietal junctions (TPJ), medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC)/precuneus], total CTQ scores were positively associated with activation of the PCC/precuneus. Second, exploratory analyses for the rest of the brain (i.e., ROIs masked-out), revealed a positive association between trauma exposure and activation of the dorsomedial prefrontal cortex (dmPFC), and a negative association with activation of the anterior section of the TPJ. These results suggest that childhood trauma exposure may, at least partially, contribute to functional alterations of brain regions essential for effective mental state inference in schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Changes in brain activation patterns according to cross-training effect in serial reaction time task An functional MRI study

    Institute of Scientific and Technical Information of China (English)

    Yong Hyun Kwon; Jung Won Kwon; Ji Won Park

    2013-01-01

    Cross-training is a phenomenon related to motor learning, where motor performance of the untrained limb shows improvement in strength and skill execution following unilateral training of the homologous contralateral limb. We used functional MRI to investigate whether motor performance of the untrained limb could be improved using a serial reaction time task according to motor sequential learning of the trained limb, and whether these skill acquisitions led to changes in brain activation patterns. We recruited 20 right-handed healthy subjects, who were randomly allocated into training and control groups. The training group was trained in performance of a serial reaction time task using their non-dominant left hand, 40 minutes per day, for 10 days, over a period of 2 weeks. The control group did not receive training. Measurements of response time and percentile of response accuracy were performed twice during pre- and post-training, while brain functional MRI was scanned during performance of the serial reaction time task using the untrained right hand. In the training group, prominent changes in response time and percentile of response accuracy were observed in both the untrained right hand and the trained left hand between pre- and post-training. The control group showed no significant changes in the untrained hand between pre- and post-training. In the training group, the activated volume of the cortical areas related to motor function (i.e., primary motor cortex, premotor area, posterior parietal cortex) showed a gradual decrease, and enhanced cerebellar activation of the vermis and the newly activated ipsilateral dentate nucleus were observed during performance of the serial reaction time task using the untrained right hand, accompanied by the cross-motor learning effect. However, no significant changes were observed in the control group. Our findings indicate that motor skills learned over the 2-week training using the trained limb were transferred to the

  6. Functional relationships between the hippocampus and dorsomedial striatum in learning a visual scene-based memory task in rats.

    Science.gov (United States)

    Delcasso, Sébastien; Huh, Namjung; Byeon, Jung Seop; Lee, Jihyun; Jung, Min Whan; Lee, Inah

    2014-11-19

    The hippocampus is important for contextual behavior, and the striatum plays key roles in decision making. When studying the functional relationships with the hippocampus, prior studies have focused mostly on the dorsolateral striatum (DLS), emphasizing the antagonistic relationships between the hippocampus and DLS in spatial versus response learning. By contrast, the functional relationships between the dorsomedial striatum (DMS) and hippocampus are relatively unknown. The current study reports that lesions to both the hippocampus and DMS profoundly impaired performance of rats in a visual scene-based memory task in which the animals were required to make a choice response by using visual scenes displayed in the background. Analysis of simultaneous recordings of local field potentials revealed that the gamma oscillatory power was higher in the DMS, but not in CA1, when the rat performed the task using familiar scenes than novel ones. In addition, the CA1-DMS networks increased coherence at γ, but not at θ, rhythm as the rat mastered the task. At the single-unit level, the neuronal populations in CA1 and DMS showed differential firing patterns when responses were made using familiar visual scenes than novel ones. Such learning-dependent firing patterns were observed earlier in the DMS than in CA1 before the rat made choice responses. The present findings suggest that both the hippocampus and DMS process memory representations for visual scenes in parallel with different time courses and that flexible choice action using background visual scenes requires coordinated operations of the hippocampus and DMS at γ frequencies. Copyright © 2014 the authors 0270-6474/14/3415534-14$15.00/0.

  7. Autistic fluid intelligence: Increased reliance on visual functional connectivity with diminished modulation of coupling by task difficulty.

    Science.gov (United States)

    Simard, Isabelle; Luck, David; Mottron, Laurent; Zeffiro, Thomas A; Soulières, Isabelle

    2015-01-01

    Different test types lead to different intelligence estimates in autism, as illustrated by the fact that autistic individuals obtain higher scores on the Raven's Progressive Matrices (RSPM) test than they do on the Wechsler IQ, in contrast to relatively similar performance on both tests in non-autistic individuals. However, the cerebral processes underlying these differences are not well understood. This study investigated whether activity in the fluid "reasoning" network, which includes frontal, parietal, temporal and occipital regions, is differently modulated by task complexity in autistic and non-autistic individuals during the RSPM. In this purpose, we used fMRI to study autistic and non-autistic participants solving the 60 RSPM problems focussing on regions and networks involved in reasoning complexity. As complexity increased, activity in the left superior occipital gyrus and the left middle occipital gyrus increased for autistic participants, whereas non-autistic participants showed increased activity in the left middle frontal gyrus and bilateral precuneus. Using psychophysiological interaction analyses (PPI), we then verified in which regions did functional connectivity increase as a function of reasoning complexity. PPI analyses revealed greater connectivity in autistic, compared to non-autistic participants, between the left inferior occipital gyrus and areas in the left superior frontal gyrus, right superior parietal lobe, right middle occipital gyrus and right inferior temporal gyrus. We also observed generally less modulation of the reasoning network as complexity increased in autistic participants. These results suggest that autistic individuals, when confronted with increasing task complexity, rely mainly on visuospatial processes when solving more complex matrices. In addition to the now well-established enhanced activity observed in visual areas in a range of tasks, these results suggest that the enhanced reliance on visual perception has a

  8. Autistic fluid intelligence: Increased reliance on visual functional connectivity with diminished modulation of coupling by task difficulty

    Directory of Open Access Journals (Sweden)

    Isabelle Simard

    2015-01-01

    Full Text Available Different test types lead to different intelligence estimates in autism, as illustrated by the fact that autistic individuals obtain higher scores on the Raven's Progressive Matrices (RSPM test than they do on the Wechsler IQ, in contrast to relatively similar performance on both tests in non-autistic individuals. However, the cerebral processes underlying these differences are not well understood. This study investigated whether activity in the fluid “reasoning” network, which includes frontal, parietal, temporal and occipital regions, is differently modulated by task complexity in autistic and non-autistic individuals during the RSPM. In this purpose, we used fMRI to study autistic and non-autistic participants solving the 60 RSPM problems focussing on regions and networks involved in reasoning complexity. As complexity increased, activity in the left superior occipital gyrus and the left middle occipital gyrus increased for autistic participants, whereas non-autistic participants showed increased activity in the left middle frontal gyrus and bilateral precuneus. Using psychophysiological interaction analyses (PPI, we then verified in which regions did functional connectivity increase as a function of reasoning complexity. PPI analyses revealed greater connectivity in autistic, compared to non-autistic participants, between the left inferior occipital gyrus and areas in the left superior frontal gyrus, right superior parietal lobe, right middle occipital gyrus and right inferior temporal gyrus. We also observed generally less modulation of the reasoning network as complexity increased in autistic participants. These results suggest that autistic individuals, when confronted with increasing task complexity, rely mainly on visuospatial processes when solving more complex matrices. In addition to the now well-established enhanced activity observed in visual areas in a range of tasks, these results suggest that the enhanced reliance on visual

  9. Functional foods and cardiometabolic diseases : International Task Force for Prevention of Cardiometabolic Diseases

    NARCIS (Netherlands)

    Assman, G.; Buono, P.; Valle, Della E.; Farinaro, E.; Ferns, G.; Krogh, V.; Kromhout, D.

    2014-01-01

    Mounting evidence supports the hypothesis that functional foods containing physiologically-active components may be healthful. Longitudinal cohort studies have shown that some food classes and dietary patterns are beneficial in primary prevention, and this has led to the identification of putative f

  10. Executive and Attentional Functions in Chronic Pain: Does Performance Decrease with Increasing Task Load?

    Directory of Open Access Journals (Sweden)

    Joukje M Oosterman

    2012-01-01

    Full Text Available BACKGROUND: Diminished executive function and attentional control has been reported in chronic pain patients. However, the precise pattern of impairment in these aspects of cognition in chronic pain remains unclear. Moreover, a decline in psychomotor speed could potentially influence executive and attentional control performance in pain patients.

  11. Impaired Executive Functions in Subjects with Frequent Nightmares as Reflected by Performance in Different Neuropsychological Tasks

    Science.gov (United States)

    Simor, Peter; Pajkossy, Peter; Horvath, Klara; Bodizs, Robert

    2012-01-01

    Nightmare disorder is a prevalent parasomnia characterized by vivid and highly unpleasant dream experiences during night time sleep. The neural background of disturbed dreaming was proposed to be associated with impaired prefrontal and fronto-limbic functioning during REM sleep. We hypothesized that the impaired prefrontal and fronto-limbic…

  12. Sensory Sensitivities and Performance on Sensory Perceptual Tasks in High-Functioning Individuals with Autism

    Science.gov (United States)

    Minshew, Nancy J.; Hobson, Jessica A.

    2008-01-01

    Most reports of sensory symptoms in autism are second hand or observational, and there is little evidence of a neurological basis. Sixty individuals with high-functioning autism and 61 matched typical participants were administered a sensory questionnaire and neuropsychological tests of elementary and higher cortical sensory perception. Thirty-two…

  13. Effects of strength training, detraining and retraining in muscle strength, hypertrophy and functional tasks in older female adults.

    Science.gov (United States)

    Correa, Cleiton S; Cunha, Giovani; Marques, Nise; Oliveira-Reischak, Ãlvaro; Pinto, Ronei

    2016-07-01

    Previous studies presented different results regarding the maintenance time of muscular adaptations after strength training and the ability to resume the gains on muscular performance after resumption of the training programme. This study aimed to verify the effect of strength training on knee extensors and elbow flexor muscle strength, rectus femoris muscle volume and functional performance in older female adults after 12 weeks of strength training, 1 year of detraining and followed by 12 weeks of retraining. Twelve sedentary older women performed 12 weeks of strength training, 1 year of detraining and 12 weeks of retraining. The strength training was performed twice a week, and the assessment was made four times: at the baseline, after the strength training, after the detraining and after the retraining. The knee extensor and elbow flexor strength, rectus femoris muscle volume and functional task were assessed. Strength of knee extensor and elbow flexor muscles, rectus femoris muscle volume and 30-s sit-to-stand increased from baseline to post-training (respectively, 40%, 70%, 38% and 46%), decreased after detraining (respectively, -36%, -64%, -35% and -43%) and increased again these parameters after retraining (35%, 68%, 36% and 42%). Strength training induces gains on strength and hypertrophy, also increased the performance on functional tasks after the strength training. The stoppage of the strength caused strength loss and reduction of functional performance. The resumption of the strength training promoted the same gains of muscular performance in older female adults. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  14. Effects of mirror therapy combined with motor tasks on upper extremity function and activities daily living of stroke patients.

    Science.gov (United States)

    Kim, Kyunghoon; Lee, Sukmin; Kim, Donghoon; Lee, Kyoungbo; Kim, Youlim

    2016-01-01

    [Purpose] The objective of this study was to investigate the effects of mirror therapy combined with exercise tasks on the function of the upper limbs and activities of daily living. [Subjects and Methods] Twenty-five stroke patients who were receiving physical therapy at K Hospital in Gyeonggi-do, South Korea, were classified into a mirror therapy group (n=12) and a conventional therapy group (n=13). The therapies were applied for 30 minutes per day, five times per week, for a total of four weeks. Upper limb function was measured with the Action Research Arm test, the Fugl-Meyer Assessment, and the Box and Block test, and activities of daily living were measured with the Functional Independence Measure. A paired test was performed to compare the intragroup differences between before training and after four weeks of therapy, and an independent t-test was performed to compare the differences between the two groups before and after four weeks of therapy. [Results] In the intragroup comparison, both groups showed significant differences between measurements taken before and after four weeks of therapy. In the intergroup comparison, the mirror therapy group showed significant improvements compared with the conventional therapy group, both in upper limb function and activities of daily living. [Conclusion] The findings of this study demonstrated that mirror therapy is more effective than conventional therapy for the training of stroke patients to improve their upper limb function and activities of daily living.

  15. The Convected Kappa Distribution Function at Jupiter: Details from the Voyager and Galileo Missions and a Comparison to Cassini Saturn Measurements

    Science.gov (United States)

    Kane, M.; Mitchell, D. G.; Mauk, B.; Carbary, J. F.; Hill, M. E.; Dialynas, K.; Krimigis, S. M.

    2016-12-01

    The Voyager and Galileo Missions allowed detailed measurements of 20 keV-2 MeV hot ion distributions in Jupiter's magnetosphere and beyond using the LECP detector on Voyager and EPD on Galileo. The normalized convected kappa distribution function, with isotropy assumed in the plasma convection frame, has well fit hot ion observed fluxes and thus has produced meaningful and ordered physical plasma parameters including the vector bulk velocity, the characteristic energy (temperature) of the distribution, and the high energy spectral index. The kappa model produces temperatures that indicate expansion and adiabatic cooling of hot ions in the nightside, but not in the dayside. Further, there are significant variations in the plasma parameters with time and local time. There is also a boundary layer present near but within the dawn magnetopause where distribution functions were generated from data analysis of the very distant Voyager 2 crossing of this region. Here the flow is apparently entrained into the magnetosheath flow, but temperatures are hot and consistent with rapid transport of plasma from regions of the magnetosphere closer to Jupiter. These observations have led to the proposal of an empirical model of the general convection pattern at Jupiter. Remarkably, application of the convected kappa distribution model to Saturn using Cassini INCA and CHEMS measurements produces a convection pattern and kappa distribution temperature profiles that are remarkably similar when scaled by the sub-solar magnetopause distance and radial size of the planets.

  16. Evaluation of the Military Functional Assessment Program: Inter rater Reliability of Task Scores

    Science.gov (United States)

    2017-09-19

    Campbell , KY, developed the Military Functional Assessment Program (MFAP), which has been utilized since 2008 to assist military and clinical...vignette, participants rated the hypothetical Soldier’s performance outlined in the vignette using the same rating scale used by the Fort Campbell ...for Observational Data: An Overview and Tutorial. Tutorials in Quantitative Methods for Psychology, 8(1), 23– 34. Helmick, K. (2012). Fort Campbell

  17. EFFECTIVENESS OF DYNAMIC WRIST SPLINT ON DELTOID MUSCLE ACTIVITY USING FUNCTIONAL TASK PRACTICE IN POST STROKE PATIENTS

    Directory of Open Access Journals (Sweden)

    Jalaja Prakash

    2013-06-01

    Full Text Available Background:The study is to analyze the effectiveness of dynamic wrist splint on deltoid muscle activity usingfunctional task practice along with strengthening exercises in post stroke patients.Materials and Methods:Experimental study with sampling size 30 patients Group A: 15 patients. Group B: 15 patients. Sampling methodis convenient random sampling. Intervention period: 4 weeks. Settings: Bhagwan Mahaveer Jain Hospital, Vasanthnagar, Bangalore.The patient will be received; history will be taken; explained about the treatment session andinformed written consent will be taken. Patient will be made to sit comfortably. Check for safety i.e.; with armrest, back rest if necessary provide cushion. Dynamic wrist splint of appropriate size will be taken; checked forfitting of the splint for any compression and avoid other complications The initial muscle activityprior to treat-ment will be measured using EMG for deltoid. Group A: The patient will be asked to perform a given set ofactivities or tasks with splint. Group B: The patient will be asked to perform a given set of activities or taskswithout splint Each session would last for 30 minutes and frequency of 3-4 times per week. At the end oftreatment, surface EMG for deltoid is taken to check for the effectiveness of use of splint with work task duringthe rehabilitation program.Results:After 4weeks treatment period, the subjects in the group A were com-pared with the subjects in the group B. Group B had shown a significant difference with outcome measureswhen compared to group AConclusion:It is evident from the results that the subjects who used the thumbabduction supinator splint showed significant level of improvement in function and increase in deltoid muscleactivity when compared with subjects who did not use the splint as quantified using Fugl Meyer Scalefor UpperExtremity and Surface EMG.

  18. One digit interruption: the altered force patterns during functionally cylindrical grasping tasks in patients with trigger digits.

    Directory of Open Access Journals (Sweden)

    Po-Tsun Chen

    Full Text Available Most trigger digit (TD patients complain that they have problems using their hand in daily or occupational tasks due to single or multiple digits being affected. Unfortunately, clinicians do not know much about how this disease affects the subtle force coordination among digits during manipulation. Thus, this study examined the differences in force patterns during cylindrical grasp between TD and healthy subjects. Forty-two TD patients with single digit involvement were included and sorted into four groups based on the involved digits, including thumb, index, middle and ring fingers. Twelve healthy subjects volunteered as healthy controls. Two testing tasks, holding and drinking, were performed by natural grasping with minimal forces. The relations between the force of the thumb and each finger were examined by Pearson correlation coefficients. The force amount and contribution of each digit were compared between healthy controls and each TD group by the independent t test. The results showed all TD groups demonstrated altered correlation patterns of the thumb relative to each finger. Larger forces and higher contributions of the index finger were found during holding by patients with index finger involved, and also during drinking by patients with affected thumb and with affected middle finger. Although no triggering symptom occurred during grasping, the patients showed altered force patterns which may be related to the role of the affected digit in natural grasping function. In conclusion, even if only one digit was affected, the subtle force coordination of all the digits was altered during simple tasks among the TD patients. This study provides the information for the future studies to further comprehend the possible injuries secondary to the altered finger coordination and also to adopt suitable treatment strategies.

  19. Direct and indirect effects of attention and visual function on gait impairment in Parkinson's disease: influence of task and turning.

    Science.gov (United States)

    Stuart, Samuel; Galna, Brook; Delicato, Louise S; Lord, Sue; Rochester, Lynn

    2017-07-01

    Gait impairment is a core feature of Parkinson's disease (PD) which has been linked to cognitive and visual deficits, but interactions between these features are poorly understood. Monitoring saccades allows investigation of real-time cognitive and visual processes and their impact on gait when walking. This study explored: (i) saccade frequency when walking under different attentional manipulations of turning and dual-task; and (ii) direct and indirect relationships between saccades, gait impairment, vision and attention. Saccade frequency (number of fast eye movements per-second) was measured during gait in 60 PD and 40 age-matched control participants using a mobile eye-tracker. Saccade frequency was significantly reduced in PD compared to controls during all conditions. However, saccade frequency increased with a turn and decreased under dual-task for both groups. Poorer attention directly related to saccade frequency, visual function and gait impairment in PD, but not controls. Saccade frequency did not directly relate to gait in PD, but did in controls. Instead, saccade frequency and visual function deficit indirectly impacted gait impairment in PD, which was underpinned by their relationship with attention. In conclusion, our results suggest a vital role for attention with direct and indirect influences on gait impairment in PD. Attention directly impacted saccade frequency, visual function and gait impairment in PD, with connotations for falls. It also underpinned indirect impact of visual and saccadic impairment on gait. Attention therefore represents a key therapeutic target that should be considered in future research. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  20. Operator function modeling: An approach to cognitive task analysis in supervisory control systems

    Science.gov (United States)

    Mitchell, Christine M.

    1987-01-01

    In a study of models of operators in complex, automated space systems, an operator function model (OFM) methodology was extended to represent cognitive as well as manual operator activities. Development continued on a software tool called OFMdraw, which facilitates construction of an OFM by permitting construction of a heterarchic network of nodes and arcs. Emphasis was placed on development of OFMspert, an expert system designed both to model human operation and to assist real human operators. The system uses a blackboard method of problem solving to make an on-line representation of operator intentions, called ACTIN (actions interpreter).

  1. Dopamine transporter 3'UTR VNTR genotype is a marker of performance on executive function tasks in children with ADHD

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    Polotskaia Anna

    2008-06-01

    Full Text Available Abstract Background Attention-Deficit/Hyperactivity Disorder (ADHD is a heterogeneous disorder from both clinical and pathogenic viewpoints. Executive function deficits are considered among the most important pathogenic pathways leading to ADHD and may index part of the heterogeneity in this disorder. Methods To investigate the relationship between the dopamine transporter gene (SLC6A3 3'-UTR VNTR genotypes and executive function in children with ADHD, 196 children diagnosed with ADHD were sequentially recruited, genotyped, and tested using a battery of three neuropsychological tests aimed at assessing the different aspects of executive functioning. Results Taking into account a correction for multiple comparisons, the main finding of this study is a significant genotype effect on performances on the Tower of London (F = 6.902, p = 0.009 and on the Wechsler Intelligence Scale for Children, Third Edition (WISC-III Freedom From Distractibility Index (F = 7.125, p = 0.008, as well as strong trends on Self Ordered Pointing Task error scores (F = 4,996 p = 0.026 and WISC-III Digit Span performance (F = 6.28, p = 0.023. Children with the 9/10 genotype exhibited, on average, a poorer performance on all four measures compared to children with the 10/10 genotype. No effect of genotype on Wisconsin Card Sorting Test measures of performance was detected. Conclusion Results are compatible with the view that SLC6A3 genotype may modulate components of executive function performance in children with ADHD.

  2. Cortical Recruitment Patterns in Children Born Prematurely Compared with Control Subjects During a Passive Listening Functional Magnetic Resonance Imaging Task

    Science.gov (United States)

    Ment, Laura R.; Peterson, Bradley S.; Vohr, Betty; Allan, Walter; Schneider, Karen C.; Lacadie, Cheryl; Katz, Karol H.; Maller-Kesselman, Jill; Pugh, Kenneth; Duncan, Charles C.; Makuch, Robert W.; Constable, R. Todd

    2008-01-01

    Objectives To use functional magnetic resonance imaging (fMRI) to test the hypothesis that subjects who were born prematurely develop alternative systems for processing language. Study design Subjects who were born prematurely (n = 14; 600-1250 g birthweight) without neonatal brain injury and 10 matched term control subjects were examined with a fMRI passive listening task of language, the Clinical Evaluation of Language Fundamentals (CELF) and portions of the Comprehensive Test of Phonological Processing (CTOPP). The fMRI task was evaluated for both phonologic and semantic processing. Results Although there were differences in CELF scores between the subjects born prematurely and control subjects, there were no significant differences in the CTOPP measures in the 2 groups. fMRI studies demonstrated that the groups differentially engaged neural systems known to process language. Children born at term were significantly more likely to activate systems for the semantic processing of language, whereas subjects born prematurely preferentially engaged regions that subserve phonology. Conclusions At 12 years of age, children born prematurely and children born at term activate neural systems for the auditory processing of language differently. Subjects born prematurely engage different networks for phonologic processing; this strategy is associated with phonologic language scores that are similar to those of control subjects. These biologically based developmental strategies may provide the substrate for the improving language skills noted in children who are born prematurely. PMID:17011320

  3. Predictive validity of the UPDRS postural stability score and the Functional Reach Test, when compared with ecologically valid reaching tasks.

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    Jenkins, M E; Johnson, A M; Holmes, J D; Stephenson, F F; Spaulding, S J

    2010-07-01

    Balance problems and falls are a common concern among individuals with Parkinson's disease (PD). Falls frequently occur during daily activities such as reaching into cupboards in the kitchen or bathroom. This study compared the correlation among two standard postural stability tests - the postural stability score on the Unified Parkinson's Disease Rating Scale (UPDRS) and the Functional Reach Test (FRT) - and ecologically valid reaching tasks that correspond to reaching at different cupboard heights among 20 individuals with PD and 20 age-matched controls. Both the FRT and the UPDRS postural stability tests are quick measures that can be performed during the clinical examination. The FRT, but not the postural stability score, demonstrated a significant correlation with the ecologically valid reaching tasks, among individuals with PD. Furthermore the FRT scores did not correlate with the UPDRS postural stability scores, indicating that these are measuring different aspects of balance. This study suggests that the FRT score may better predict the risk of postural instability encountered during daily activities among individuals with PD.

  4. Performance of children and adolescents with Asperger syndrome or high-functioning autism on advanced theory of mind tasks.

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    Kaland, Nils; Callesen, Kirsten; Møller-Nielsen, Annette; Mortensen, Erik Lykke; Smith, Lars

    2008-07-01

    Although a number of advanced theory of mind tasks have been developed, there is a dearth of information on whether performances on different tasks are associated. The present study examined the performance of 21 children and adolescents with diagnoses of Asperger syndrome (AS) and 20 typically developing controls on three advanced theory of mind tasks: The Eyes Task, the Strange Stories, and the Stories from Everyday Life. The participants in the clinical group demonstrated lower performance than the controls on all the three tasks. The pattern of findings, however, indicates that these tasks may share different information-processing requirements in addition to tapping different mentalizing abilities.

  5. The addition of functional task-oriented mental practice to conventional physical therapy improves motor skills in daily functions after stroke

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    Clarissa C. Santos-Couto-Paz

    2013-12-01

    Full Text Available BACKGROUND: Mental practice (MP is a cognitive strategy which may improve the acquisition of motor skills and functional performance of athletes and individuals with neurological injuries. OBJECTIVE: To determine whether an individualized, specific functional task-oriented MP, when added to conventional physical therapy (PT, promoted better learning of motor skills in daily functions in individuals with chronic stroke (13±6.5 months post-stroke. METHOD: Nine individuals with stable mild and moderate upper limb impairments participated, by employing an A1-B-A2 single-case design. Phases A1 and A2 included one month of conventional PT, and phase B the addition of MP training to PT. The motor activity log (MAL-Brazil was used to assess the amount of use (AOU and quality of movement (QOM of the paretic upper limb; the revised motor imagery questionnaire (MIQ-RS to assess the abilities in kinesthetic and visual motor imagery; the Minnesota manual dexterity test to assess manual dexterity; and gait speed to assess mobility. RESULTS: After phase A1, no significant changes were observed for any of the outcome measures. However, after phase B, significant improvements were observed for the MAL, AOU and QOM scores (p<0.0001, and MIQ-RS kinesthetic and visual scores (p=0.003; p=0.007, respectively. The significant gains in manual dexterity (p=0.002 and gait speed (p=0.019 were maintained after phase A2. CONCLUSIONS: Specific functional task-oriented MP, when added to conventional PT, led to improvements in motor imagery abilities combined with increases in the AOU and QOM in daily functions, manual dexterity, and gait speed.

  6. Dexterity: A MATLAB-based analysis software suite for processing and visualizing data from tasks that measure arm or forelimb function.

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    Butensky, Samuel D; Sloan, Andrew P; Meyers, Eric; Carmel, Jason B

    2017-07-15

    Hand function is critical for independence, and neurological injury often impairs dexterity. To measure hand function in people or forelimb function in animals, sensors are employed to quantify manipulation. These sensors make assessment easier and more quantitative and allow automation of these tasks. While automated tasks improve objectivity and throughput, they also produce large amounts of data that can be burdensome to analyze. We created software called Dexterity that simplifies data analysis of automated reaching tasks. Dexterity is MATLAB software that enables quick analysis of data from forelimb tasks. Through a graphical user interface, files are loaded and data are identified and analyzed. These data can be annotated or graphed directly. Analysis is saved, and the graph and corresponding data can be exported. For additional analysis, Dexterity provides access to custom scripts created by other users. To determine the utility of Dexterity, we performed a study to evaluate the effects of task difficulty on the degree of impairment after injury. Dexterity analyzed two months of data and allowed new users to annotate the experiment, visualize results, and save and export data easily. Previous analysis of tasks was performed with custom data analysis, requiring expertise with analysis software. Dexterity made the tools required to analyze, visualize and annotate data easy to use by investigators without data science experience. Dexterity increases accessibility to automated tasks that measure dexterity by making analysis of large data intuitive, robust, and efficient. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Recalling academic tasks

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    Draper, Franklin Gno

    This study was focused on what students remembered about five middle school science tasks when they were juniors and seniors in high school. Descriptions of the five tasks were reconstructed from available artifacts and teachers' records, notes and recollections. Three of the five tasks were "authentic" in the sense that students were asked to duplicate the decisions practitioners make in the adult world. The other two tasks were more typical school tasks involving note taking and preparation for a quiz. All five tasks, however, involved use of computers. Students were interviewed to examine what and how well they recalled the tasks and what forms or patterns of recall existed. Analysis of their responses indicated that different kinds of tasks produced different levels of recall. Authentically situated tasks were remembered much better than routine school tasks. Further, authentic tasks centered on design elements were recalled better than those for which design was not as pivotal. Patterns of recall indicated that participants most often recalled the decisions they made, the scenarios of the authentically situated tasks, the consequences of their tasks and the social contexts of the classroom. Task events, in other words, appeared to form a framework upon which students constructed stories of the tasks. The more salient the events, the richer the story, the deeper and more detailed the recall of the task. Thus, authentic tasks appeared to lend themselves to creating stories better than regular school tasks and therefore such tasks were recalled better. Implications of these patterns of recall are discussed with respect to issues of school learning and assessment.

  8. THE ALGORITHM OF MESHFREE METHOD OF RADIAL BASIS FUNCTIONS IN TASKS OF UNDERGROUND HYDROMECHANICS

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    N. V. Medvid

    2016-01-01

    Full Text Available A Mathematical model of filtering consolidation in the body of soil dam with conduit andwashout zone in two-dimensional case is considered. The impact of such technogenic factors as temperature, salt concentration, subsidence of upper boundary and interior points of the dam with time is taken into account. The software to automate the calculation of numerical solution of the boundary problem by radial basis functions has been created, which enables to conduct numerical experiments by varying the input parameters and shape. The influence of the presence of conduit and washout zone on the pressure, temperature and concentration of salts in the dam body at different time intervals isinvestigated. A number of numerical experiments is conducted and the analysis of dam accidents is performed.

  9. Efficient and reversible CO2 capture by amine functionalized-silica gel confined task-specific ionic liquid system.

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    Aboudi, Javad; Vafaeezadeh, Majid

    2015-07-01

    Simple, efficient and practical CO2 capture method is reported using task-specific ionic liquid (IL) supported onto the amine-functionalized silica gel. The results have been shown that both the capacity and rate of the CO2 absorption notably increase in the supported IL/molecular sieve 4 Å system in comparison of homogeneous IL. Additionally, it has shown that the prepared material is capable for reversible carbon dioxide absorption for at least 10 cycles without significant loss of efficiency. The presence of the amine-based IL and the surface bonded amine groups increase the capacity of CO2 absorption even in a CO2/CH4 gas mixture through the formation of ammonium carbamate onto the surface of mesoporous material.

  10. Efficient and reversible CO2 capture by amine functionalized-silica gel confined task-specific ionic liquid system

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    Javad Aboudi

    2015-07-01

    Full Text Available Simple, efficient and practical CO2 capture method is reported using task-specific ionic liquid (IL supported onto the amine-functionalized silica gel. The results have been shown that both the capacity and rate of the CO2 absorption notably increase in the supported IL/molecular sieve 4 Å system in comparison of homogeneous IL. Additionally, it has shown that the prepared material is capable for reversible carbon dioxide absorption for at least 10 cycles without significant loss of efficiency. The presence of the amine-based IL and the surface bonded amine groups increase the capacity of CO2 absorption even in a CO2/CH4 gas mixture through the formation of ammonium carbamate onto the surface of mesoporous material.

  11. Functional indexes of reactive cognitive control: ERPs in cued go/no-go tasks.

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    Kropotov, Juri D; Ponomarev, Valery A; Pronina, Marina; Jäncke, Lutz

    2017-08-03

    We aimed to determine the functional meaning of latent (hidden) components decomposed from ERPs, in the context of a go/no-go paradigm. To accomplish this, we used a new group blind source separation method, based on joint diagonalization of covariance matrices of ERPs. Four variants of a frequently used go/no-go paradigm were designed, in which operations of reactive cognitive control, such as conflict detection and action inhibition, were independently manipulated. The results showed that a latent component, generated in the anterior cingulate cortex, induced N2/P3 fluctuation only in conditions in which the prepotent model was violated, and thus can be associated with conflict detection operations. In contrast, the two latent components generated in the vicinity of the central sulcus induced P3-like fluctuations in conditions in which the prepared action was suppressed, and thus can be associated with action inhibition operations. The advantages and limitations of the new blind source separation method in relation to ERP research are also discussed. © 2017 Society for Psychophysiological Research.

  12. A developmental window into trade-offs in executive function: the case of task switching versus response inhibition in 6-year-olds.

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    Blackwell, Katharine A; Chatham, Christopher H; Wiseheart, Melody; Munakata, Yuko

    2014-09-01

    Good executive function has been linked to many positive outcomes in academic performance, health, and social competence. However, some aspects of executive function may interfere with other cognitive processes. Childhood provides a unique test case for investigating such cognitive trade-offs, given the dramatic failures and developments observed during this period. For example, most children categorically switch or perseverate when asked to switch between rules on a card-sorting task. To test potential trade-offs with the development of task switching abilities, we compared 6-year-olds who switched versus perseverated in a card-sorting task on two aspects of inhibitory control: response inhibition (via a stop signal task) and interference control (via a Simon task). Across two studies, switchers showed worse response inhibition than perseverators, consistent with the idea of cognitive trade-offs; however, switchers showed better interference control than perseverators, consistent with prior work documenting benefits associated with the development of executive function. This pattern of positive and negative associations may reflect aspects of working memory (active maintenance of current goals, and clearing of prior goals) that help children focus on a single task goal but hurt in situations with conflicting goals. Implications for understanding components of executive function and their relationships across development are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Anion-Functionalized Task-Specific Ionic Liquids: Molecular Origin of Change in Viscosity upon CO2 Capture.

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    Li, Ailin; Tian, Ziqi; Yan, Tianying; Jiang, De-en; Dai, Sheng

    2014-12-26

    The structure and dynamics of a task-specific ionic liquid (TSIL), trihexyl(tetradecyl)phosphonium imidazolate, before and after absorbing CO(2) were studied with a molecular dynamics (MD) simulation. This particular ionic liquid is one of several newly discovered azole-based TSILs for equimolar CO(2) capture. Unlike other TSILs whose viscosity increases drastically upon reaction with CO(2), its viscosity decreases after CO(2) absorption. This unique behavior was confirmed in our MD simulation. We find that after CO(2) absorption the translational dynamics of the whole system is accelerated, accompanied by an accelerated rotational dynamics of the cations. Radial distribution function and spatial distribution function analyses show that the anions become asymmetric after reaction with CO(2), and this causes the imbalance of the interaction between the positive and negative regions of the ions. The interaction between the phosphorus atom of the cation and oxygen atoms of the carboxyl group on the anion is enhanced, while that between the phosphorus atom and the naked nitrogen atom of the anion is weakened. The ion-pair correlation functions further support that the weakened interaction leads to faster dissociation of cation-anion pairs, thereby causing an accelerated dynamics. Hence, the asymmetry of anions influences the dynamics of the system and affects the viscosity. This insight may help design better TSILs with decreased viscosity for CO(2) capture.

  14. Effects of the length and timing of nighttime naps on task performance and physiological function

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    Hidemaro Takeyama

    2004-12-01

    Full Text Available OBJECTIVE: To examine the effects of the length and timing of nighttime naps on performance and physiological functions, an experimental study was carried out under simulated night shift schedules. METHODS: Six students were recruited for this study that was composed of 5 experiments. Each experiment involved 3 consecutive days with one night shift (22:00-8:00 followed by daytime sleep and night sleep. The experiments had 5 conditions in which the length and timing of naps were manipulated: 0:00-1:00 (E60, 0:00-2:00 (E120, 4:00-5:00 (L60, 4:00-6:00 (L120, and no nap (No-nap. During the night shifts, participants underwent performance tests. A questionnaire on subjective fatigue and a critical flicker fusion frequency test were administered after the performance tests. Heart rate variability and rectal temperature were recorded continuously during the experiments. Polysomnography was also recorded during the nap. RESULTS: Sleep latency was shorter and sleep efficiency was higher in the nap in L60 and L120 than that in E60 and E120. Slow wave sleep in the naps in E120 and L120 was longer than that in E60 and L60. The mean reaction time in L60 became longer after the nap, and faster in E60 and E120. Earlier naps serve to counteract the decrement in performance and physiological functions during night shifts. Performance was somewhat improved by taking a 2-hour nap later in the shift, but deteriorated after a one-hour nap. CONCLUSIONS: Naps in the latter half of the night shift were superior to earlier naps in terms of sleep quality. However performance declined after a 1-hour nap taken later in the night shift due to sleep inertia. This study suggests that appropriate timing of a short nap must be carefully considered, such as a 60-min nap during the night shift.OBJETIVO: Para investigar os efeitos da duração e horário de cochilos noturnos sobre o desempenho e as funções fisiológicas foi realizado um estudo experimental por meio do trabalho

  15. Association between Fish Consumption and Prefrontal Function during a Cognitive Task in Male Japanese Workers: A Multi-Channel Near-Infrared Spectroscopy Study.

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    Shenghong Pu

    Full Text Available The purpose of this study was to examine the relationship between fish consumption and prefrontal function during a cognitive task in male Japanese workers. The study included 208 male workers who underwent medical health examinations 3 months after a change in their work assignment. We measured the hemoglobin concentration changes in the prefrontal region during working memory tasks using 52-channel near-infrared spectroscopy. The frequency of fish consumption was calculated on the basis of the subjects' self-reported customary intake frequency over the previous 3 months. A significant positive relationship was observed between fish consumption and left dorsolateral prefrontal function during a working memory task. To our knowledge, this is the first study to report an association between fish consumption and functional cortical activity with an ample sample size, suggesting that fish consumption modulates functional activity in the left dorsolateral prefrontal cortex.

  16. Cross-hemispheric collaboration and segregation associated with task difficulty as revealed by structural and functional connectivity.

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    Davis, Simon W; Cabeza, Roberto

    2015-05-27

    Although it is known that brain regions in one hemisphere may interact very closely with their corresponding contralateral regions (collaboration) or operate relatively independent of them (segregation), the specific brain regions (where) and conditions (how) associated with collaboration or segregation are largely unknown. We investigated these issues using a split field-matching task in which participants matched the meaning of words or the visual features of faces presented to the same (unilateral) or to different (bilateral) visual fields. Matching difficulty was manipulated by varying the semantic similarity of words or the visual similarity of faces. We assessed the white matter using the fractional anisotropy (FA) measure provided by diffusion tensor imaging (DTI) and cross-hemispheric communication in terms of fMRI-based connectivity between homotopic pairs of cortical regions. For both perceptual and semantic matching, bilateral trials became faster than unilateral trials as difficulty increased (bilateral processing advantage, BPA). The study yielded three novel findings. First, whereas FA in anterior corpus callosum (genu) correlated with word-matching BPA, FA in posterior corpus callosum (splenium-occipital) correlated with face-matching BPA. Second, as matching difficulty intensified, cross-hemispheric functional connectivity (CFC) increased in domain-general frontopolar cortex (for both word and face matching) but decreased in domain-specific ventral temporal lobe regions (temporal pole for word matching and fusiform gyrus for face matching). Last, a mediation analysis linking DTI and fMRI data showed that CFC mediated the effect of callosal FA on BPA. These findings clarify the mechanisms by which the hemispheres interact to perform complex cognitive tasks.

  17. Functional Correlates of childhood maltreatment and symptom severity during affective theory of mind tasks in chronic depression.

    Science.gov (United States)

    Hentze, Charlotte; Walter, Henrik; Schramm, Elisabeth; Drost, Sarah; Schoepf, Dieter; Fangmeier, Thomas; Mattern, Margarete; Normann, Claus; Zobel, Ingo; Schnell, Knut

    2016-04-30

    Among multiple etiological factors of depressive disorders, childhood maltreatment (CM) gains increasing attention as it confers susceptibility for depression and predisposes to chronicity. CM assumedly inhibits social-cognitive development, entailing interactional problems as observed in chronic depression (CD), especially in affective theory of mind (ToM). However, the extent of CM among CD patients varies notably as does the severity of depressive symptoms. We tested whether the extent of CM or depressive symptoms correlates with affective ToM functions in CD patients. Regional brain activation measured by functional magnetic resonance imaging during an affective ToM task was tested for correlation with CM, assessed by the Childhood Trauma Questionnaire (CTQ), and symptom severity, assessed by the Montgomery-Åsberg Depression Rating Scale (MADRS), in 25 unmedicated CD patients (mean age 41.52, SD 11.13). Amygdala activation during affective ToM correlated positively with CTQ total scores, while (para)hippocampal response correlated negatively with MADRS scores. Our findings suggest that differential amygdala activation in affective ToM in CD is substantially modulated by previous CM and not by the pathophysiological equivalents of current depressive symptoms. This illustrates the amygdala's role in the mediation of CM effects. The negative correlation of differential (para)hippocampal activation and depressive symptom severity indicates reduced integration of interactional experiences during depressive states.

  18. Investigation of the prefrontal cortex in response to duration-variable anagram tasks using functional near infrared spectroscopy

    Science.gov (United States)

    Tian, Fenghua; Chance, Britton; Liu, Hanli

    2009-02-01

    The Prefrontal Cortex (PFC) in response to anagram tasks was investigated using multi-channel, functional Near Infrared Spectroscopy (fNIRS). The study focused on the variability of PFC response with variable anagram durations (executing time). The duration of the anagram ranged from a few seconds to over one minute. The topographic image of PFC showed high lateral consistency across different anagram durations and did not show remarkable discrimination between two difficulty levels: 4-letter and 6-letter anagrams. The superposition principle of a linear system model was employed to investigate the possible non-linearity between three discrete duration subgroups (D1 = 2 +/- 0.33, D2 = 4 +/- 0.67, and D3 = 8 +/- 1.00 sec) and their resultant fNIR readings. Such analysis showed clearly a nonlinear behavior in fNIRS signals within the duration range of less than 4 sec, agreeing with the previous studies on cognitive response measured with functional Magnetic Resonant Imaging (fMRI). To our knowledge, this is the first report on the nonlinearity of cognitive response using fNIRS.

  19. The Role of the Supplementary Motor Region in Overt Reading: Evidence for Differential Processing in SMA-Proper and Pre-SMA as a Function of Task Demands.

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    Cummine, Jacqueline; Hanif, Wahab; Dymouriak-Tymashov, Inna; Anchuri, Kavya; Chiu, Stephanie; Boliek, Carol A

    2017-03-04

    A differentiation in function between the pre-SMA (i.e., cognitive load) and the SMA-proper (i.e., motor execution) has been described (Zhang et al., Cereb Cortex 22:99-111, 2012). These differential SMA functions may be influential in overt reading tasks. The present study examined the relationships between various segments of the SMA and overt reading through the modulation of task demands in an effort to explore the complexity of the print-to-speech network. Skilled reading adults (N = 15) took part in five overt reading tasks: pure regular word reading, pure exception word reading, mixed regular word and exception word reading, go/no-go reading with nonword foils and go/no-go reading with pseudohomophone foils. Five regions of interest that spanned the pre-SMA to the SMA-proper were isolated. Behaviour-function relationships were tested to examine the associations between performance (response time) and brain activity (percent signal change). Further, the coherence between feedforward (SMA) and feedback (supramarginal gyrus) regions were explored to further refine the print-to-speech network. We found that the pre-SMA was related to cognitively demanding tasks (go/no-go with pseudohomophones), whereas the SMA-proper was related to an automatized task (pure regular words). Notably, only those tasks that required information from the feedback system (i.e., mixed word lists, go/no-go tasks) showed connections between SMA regions and the supramarginal gyrus, which is in line with the role of feedback and feedforward systems in the print-to-speech network. Together, these results support the notion that the pre-SMA and SMA-proper are sensitive to reading tasks that differentially invoke higher cognitive resources (mixed word lists, go/no-go) versus automatized articulation (pure lists), respectively. We discuss our findings in the context of print-to-speech neural networks.

  20. Profound expressive language impairment in low functioning children with autism: an investigation of syntactic awareness using a computerised learning task.

    Science.gov (United States)

    McGonigle-Chalmers, Maggie; Alderson-Day, Ben; Fleming, Joanna; Monsen, Karl

    2013-09-01

    Nine low-functioning children with profound expressive language impairment and autism were studied in terms of their responsiveness to a computer-based learning program designed to assess syntactic awareness. The children learned to touch words on a screen in the correct sequence in order to see a corresponding animation, such as 'monkey flies'. The game progressed in levels from 2 to 4 word sequences, contingent upon success at each stage. Although performance was highly variable across participants, a detailed review of their learning profiles suggested that no child lacked syntactic awareness and that elementary syntactic control in a non-speech domain was superior to that manifest in their spoken language. The reasons for production failures at the level of speech in children with autism are discussed.

  1. Transient increase in systemic interferences in the superficial layer and its influence on event-related motor tasks: a functional near-infrared spectroscopy study

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    Nambu, Isao; Ozawa, Takuya; Sato, Takanori; Aihara, Takatsugu; Fujiwara, Yusuke; Otaka, Yohei; Osu, Rieko; Izawa, Jun; Wada, Yasuhiro

    2017-03-01

    Functional near-infrared spectroscopy (fNIRS) is a widely utilized neuroimaging tool in fundamental neuroscience research and clinical investigation. Previous research has revealed that task-evoked systemic artifacts mainly originating from the superficial-tissue may preclude the identification of cerebral activation during a given task. We examined the influence of such artifacts on event-related brain activity during a brisk squeezing movement. We estimated task-evoked superficial-tissue hemodynamics from short source-detector distance channels (15 mm) by applying principal component analysis. The estimated superficial-tissue hemodynamics exhibited temporal profiles similar to the canonical cerebral hemodynamic model. Importantly, this task-evoked profile was also observed in data from a block design motor experiment, suggesting a transient increase in superficial-tissue hemodynamics occurs following motor behavior, irrespective of task design. We also confirmed that estimation of event-related cerebral hemodynamics was improved by a simple superficial-tissue hemodynamic artifact removal process using 15-mm short distance channels, compared to the results when no artifact removal was applied. Thus, our results elucidate task design-independent characteristics of superficial-tissue hemodynamics and highlight the need for the application of superficial-tissue hemodynamic artifact removal methods when analyzing fNIRS data obtained during event-related motor tasks.

  2. Detailed analysis of distraction induced by in-vehicle verbal interactions on visual search performance

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    Kazumitsu Shinohara

    2010-07-01

    Full Text Available We examined the negative effect of in-vehicle verbal interaction on visual search performance. Twenty participants performed a primary visual search task and a secondary verbal interaction task concurrently. We found that visual search performance deteriorated when the secondary task involving memory retrieval and speech production was performed concurrently. Moreover, a detailed analysis of the reaction time as a function of set size revealed that the increased reaction time was attributed not to the slowing of inspecting each item but to the increased processing time other than the inspection of each visual item, possibly due to task switching between the primary visual search task and the secondary verbal task. These findings have implications for providing information from in-vehicle information devices while reducing the risk of driver distraction.

  3. The effect of voice quality and competing speakers in a passage comprehension task: perceived effort in relation to cognitive functioning and performance in children with normal hearing.

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    von Lochow, Heike; Lyberg-Åhlander, Viveka; Sahlén, Birgitta; Kastberg, Tobias; Brännström, K Jonas

    2017-04-03

    The study investigates the effect of voice quality and competing speakers on perceived effort in a passage comprehension task in relation to cognitive functioning. In addition, it explores if perceived effort was related to performance. A total of 49 children (aged 7:03 to 12:02 years) with normal hearing participated. The children performed an auditory passage comprehension task presented with six different listening conditions consisting of a typical voice or a dysphonic voice presented in quiet, with one competing speaker, and with four competing speakers. After completing the task, they rated their perceived effort on a five-grade scale. The children also performed tasks measuring working memory capacity (WMC) and executive functioning. The results show that voice quality had no direct effect on perceived effort but the children's ratings of perceived effort were related to their executive functioning. A significant effect was seen for background listening condition indicating higher perceived effort for background listening conditions with competing speakers. The effects of background listening condition were mainly related to the children's WMC but also their executive functioning. It can be concluded that the individual susceptibility to the effect of the dysphonic voice is related to the child's executive functioning. The individual susceptibility to the presence of competing speakers is related to the child's WMC and executive functioning.

  4. PreSurgMapp: a MATLAB Toolbox for Presurgical Mapping of Eloquent Functional Areas Based on Task-Related and Resting-State Functional MRI.

    Science.gov (United States)

    Huang, Huiyuan; Ding, Zhongxiang; Mao, Dewang; Yuan, Jianhua; Zhu, Fangmei; Chen, Shuda; Xu, Yan; Lou, Lin; Feng, Xiaoyan; Qi, Le; Qiu, Wusi; Zhang, Han; Zang, Yu-Feng

    2016-10-01

    The main goal of brain tumor surgery is to maximize tumor resection while minimizing the risk of irreversible postoperative functional sequelae. Eloquent functional areas should be delineated preoperatively, particularly for patients with tumors near eloquent areas. Functional magnetic resonance imaging (fMRI) is a noninvasive technique that demonstrates great promise for presurgical planning. However, specialized data processing toolkits for presurgical planning remain lacking. Based on several functions in open-source software such as Statistical Parametric Mapping (SPM), Resting-State fMRI Data Analysis Toolkit (REST), Data Processing Assistant for Resting-State fMRI (DPARSF) and Multiple Independent Component Analysis (MICA), here, we introduce an open-source MATLAB toolbox named PreSurgMapp. This toolbox can reveal eloquent areas using comprehensive methods and various complementary fMRI modalities. For example, PreSurgMapp supports both model-based (general linear model, GLM, and seed correlation) and data-driven (independent component analysis, ICA) methods and processes both task-based and resting-state fMRI data. PreSurgMapp is designed for highly automatic and individualized functional mapping with a user-friendly graphical user interface (GUI) for time-saving pipeline processing. For example, sensorimotor and language-related components can be automatically identified without human input interference using an effective, accurate component identification algorithm using discriminability index. All the results generated can be further evaluated and compared by neuro-radiologists or neurosurgeons. This software has substantial value for clinical neuro-radiology and neuro-oncology, including application to patients with low- and high-grade brain tumors and those with epilepsy foci in the dominant language hemisphere who are planning to undergo a temporal lobectomy.

  5. Vigilance task-related change in brain functional connectivity as revealed by wavelet phase coherence analysis of near-infrared spectroscopy signals

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2016-08-01

    Full Text Available This study aims to assess the vigilance task-related change in connectivity in healthy adults using wavelet phase coherence (WPCO analysis of near-infrared spectroscopy signals (NIRS. NIRS is a non-invasive neuroimaging technique for assessing brain activity. Continuous recordings of the NIRS signals were obtained from the prefrontal cortex (PFC and sensorimotor cortical areas of 20 young healthy adults (24.9±3.3 years during a 10-min resting state and a 20-min vigilance task state. The vigilance task was used to simulate driving mental load by judging three random numbers (i.e., whether odd numbers. The task was divided into two sessions: the first 10 minutes (Task t1 and the second 10 minutes (Task t2. The WPCO of six channel pairs were calculated in five frequency intervals: 0.6–2 Hz (I, 0.145–0.6 Hz (II, 0.052–0.145 Hz (III, 0.021–0.052 Hz (IV, and 0.0095–0.021 Hz (V. The significant WPCO formed global connectivity (GC maps in intervals I and II and functional connectivity (FC maps in intervals III to V. Results show that the GC levels in interval I and FC levels in interval III were significantly lower in the Task t2 than in the resting state (p < 0.05, particularly between the left PFC and bilateral sensorimotor regions. Also, the reaction time shows an increase in Task t2 compared with that in Task t1. However, no significant difference in WPCO was found between Task t1 and resting state. The results showed that the change in FC at the range of 0.6-2 Hz was not attributed to the vigilance task pe se, but the interaction effect of vigilance task and time factors. The findings suggest that the decreased attention level might be partly attributed to the reduced GC levels between the left prefrontal region and sensorimotor area. The present results provide a new insight into the vigilance task-related brain activity.

  6. The test-retest reliability of the latent construct of executive function depends on whether tasks are represented as formative or reflective indicators.

    Science.gov (United States)

    Willoughby, Michael T; Kuhn, Laura J; Blair, Clancy B; Samek, Anya; List, John A

    2017-10-01

    This study investigates the test-retest reliability of a battery of executive function (EF) tasks with a specific interest in testing whether the method that is used to create a battery-wide score would result in differences in the apparent test-retest reliability of children's performance. A total of 188 4-year-olds completed a battery of computerized EF tasks twice across a period of approximately two weeks. Two different approaches were used to create a score that indexed children's overall performance on the battery-i.e., (1) the mean score of all completed tasks and (2) a factor score estimate which used confirmatory factor analysis (CFA). Pearson and intra-class correlations were used to investigate the test-retest reliability of individual EF tasks, as well as an overall battery score. Consistent with previous studies, the test-retest reliability of individual tasks was modest (rs ≈ .60). The test-retest reliability of the overall battery scores differed depending on the scoring approach (rmean = .72; rfactor_score = .99). It is concluded that the children's performance on individual EF tasks exhibit modest levels of test-retest reliability. This underscores the importance of administering multiple tasks and aggregating performance across these tasks in order to improve precision of measurement. However, the specific strategy that is used has a large impact on the apparent test-retest reliability of the overall score. These results replicate our earlier findings and provide additional cautionary evidence against the routine use of factor analytic approaches for representing individual performance across a battery of EF tasks.

  7. Neural correlates of post-error slowing during a stop signal task: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Li, Chiang-shan Ray; Huang, Cong; Yan, Peisi; Paliwal, Prashni; Constable, Robert Todd; Sinha, Rajita

    2008-06-01

    The ability to detect errors and adjust behavior accordingly is essential for maneuvering in an uncertain environment. Errors are particularly prone to occur when multiple, conflicting responses are registered in a situation that requires flexible behavioral outputs; for instance, when a go signal requires a response and a stop signal requires inhibition of the response during a stop signal task (SST). Previous studies employing the SST have provided ample evidence indicating the importance of the medial cortical brain regions in conflict/error processing. Other studies have also related these regional activations to postconflict/error behavioral adjustment. However, very few studies have directly explored the neural correlates of postconflict/error behavioral adjustment. Here we employed an SST to elicit errors in approximately half of the stop trials despite constant behavioral adjustment of the observers. Using functional magnetic resonance imaging, we showed that prefrontal loci including the ventrolateral prefrontal cortex are involved in post-error slowing in reaction time. These results delineate the neural circuitry specifically involved in error-associated behavioral modifications.

  8. The Benefits of Endurance Exercise and Tai Chi Chuan for the Task-Switching Aspect of Executive Function in Older Adults: An ERP Study

    Directory of Open Access Journals (Sweden)

    Dong-Yang eFong

    2014-10-01

    Full Text Available This study was designed to determine the relationship between physical activity and the task-switching aspect of executive function by investigating the modulating roles of age, modality of physical activity, and type of cognitive function using behavioral and event-related potential (ERP assessments. Sixty-four participants were assigned to one of four groups based on age and history of physical activity: older adults performing endurance exercise (OEE, older adults practicing Tai Chi Chuan (OTC, older adults with a sedentary lifestyle (OSL, and young adults (YA. Study participants completed a task-switching task under homogeneous and heterogeneous conditions while ERPs were recorded. The results revealed that YA had shortest reaction times compared with the three older adults groups, with OSL exhibiting the longest reaction time. YA also exhibited shorter P3 latency than OSL. No differences were observed in P3 amplitude between YA, OEE, and OTC; however, all three groups had a significantly larger P3 amplitude compared with OSL in both task conditions. In conclusion, age and participation in physical activity influence the relationship between physical activity and task-switching, and a positive relationship was observed regardless of the modality of physical activity and type of cognitive function. Our ERP findings support the model of the scaffolding theory of aging and cognition and suggest that regular participation in endurance exercise and Tai Chi Chuan may have equivalent beneficial effects on cognition at the behavioral and neuroelectric levels.

  9. The benefits of endurance exercise and Tai Chi Chuan for the task-switching aspect of executive function in older adults: an ERP study.

    Science.gov (United States)

    Fong, Dong-Yang; Chi, Li-Kang; Li, Fuzhong; Chang, Yu-Kai

    2014-01-01

    This study was designed to determine the relationship between physical activity and the task-switching aspect of executive function by investigating the modulating roles of age, modality of physical activity, and type of cognitive function using behavioral and event-related potential (ERP) assessments. Sixty-four participants were assigned to one of four groups based on age and history of physical activity: older adults performing endurance exercise (OEE), older adults practicing Tai Chi Chuan (OTC), older adults with a sedentary lifestyle (OSL), and young adults (YA). Study participants completed a task-switching task under homogeneous and heterogeneous conditions while ERPs were recorded. The results revealed that YA had shortest reaction times compared with the three older adults groups, with OSL exhibiting the longest reaction time. YA also exhibited shorter P3 latency than OSL. No differences were observed in P3 amplitude between YA, OEE, and OTC; however, all three groups had significantly larger P3 amplitude compared with OSL in both task conditions. In conclusion, age and participation in physical activity influence the relationship between physical activity and task-switching, and a positive relationship was observed regardless of the modality of physical activity and type of cognitive function. Our ERP findings support the model of the scaffolding theory of aging and cognition (STAC) and suggest that regular participation in endurance exercise and Tai Chi Chuan may have equivalent beneficial effects on cognition at the behavioral and neuroelectric levels.

  10. Performance of children and adolescents with Asperger syndrome or high-functioning autism on advanced theory of mind tasks

    DEFF Research Database (Denmark)

    Kaland, Nils; Callesen, Kirsten; Møller-Nielsen, Annette

    2008-01-01

    Although a number of advanced theory of mind tasks have been developed, there is a dearth of information on whether performances on different tasks are associated. The present study examined the performance of 21 children and adolescents with diagnoses of Asperger syndrome (AS) and 20 typically...

  11. The Use of Video Self-Modeling to Increase On-Task Behavior in Children with High-Functioning Autism

    Science.gov (United States)

    Schatz, Rochelle B.; Peterson, Rachel K.; Bellini, Scott

    2016-01-01

    In the present study, the researchers implemented a video self-modeling intervention for increasing on-task classroom behavior for three elementary school students diagnosed with an autism spectrum disorder. The researchers observed the students' on-task engagement three times a week during their respective math classes. A multiple baseline design…

  12. A data-driven investigation of gray matter–function correlations in schizophrenia during a working memory task

    Directory of Open Access Journals (Sweden)

    Andrew eMichael

    2011-08-01

    Full Text Available The brain is a vastly interconnected organ and methods are needed to investigate its long range structure(S–function(F associations to better understand disorders such as Schizophrenia that are hypothesized to be due to distributed disconnected brain regions. In previous work we introduced a methodology to reduce the whole brain S–F correlations to a histogram and here we reduce the correlations to brain clusters. The application of our approach to sMRI (gray matter concentration maps and fMRI data (GLM activation maps during Encode and Probe epochs of a working memory task from patients with schizophrenia (SZ, n=100 and healthy controls (HC, n=100 presented the following results. In HC the whole brain correlation histograms for gray matter(GM–Encode and GM–Probe overlap for Low and Medium loads and at High the histograms separate, but in SZ the histograms do not overlap for any of the load levels and Medium load shows the maximum difference. We computed GM–F differential correlation clusters using activation for Probe Medium, and they included regions in the left and right superior temporal gyri, anterior cingulate, cuneus, middle temporal gyrus and the cerebellum. Inter-cluster GM–Probe correlations for Medium load were positive in HC but negative in SZ. Within group inter-cluster GM–Encode and GM–Probe correlation comparisons show no differences in HC but in SZ differences are evident in the same clusters where HC versus SZ differences occurred for Probe Medium, indicating that the S–F integrity during Probe is aberrant in SZ. Through a data-driven whole brain analysis approach we find novel brain clusters and show how the S–F differential correlation changes during Probe and Encode at three memory load levels. Structural and functional anomalies have been extensively reported in schizophrenia and here we provide evidences to suggest that evaluating S–F associations can provide important additional information.

  13. Development and initial testing of functional task exercise on older adults with cognitive impairment at risk of Alzheimer's disease--FcTSim programme--a feasibility study.

    Science.gov (United States)

    Law, Lawla L F; Barnett, Fiona; Yau, Matthew K; Gray, Marion A

    2013-12-01

    The purpose of this study was to illustrate the development of a new functional task-based exercise programme and initially test its feasibility as well as effectiveness for older adults with mild cognitive impairment (MCI). This study used a single-group repeated-measures design. A total of 11 patients (mean age 71.8 years) were recruited to participate in a structured functional task exercise programme for 10 weeks. All outcome measures were undertaken at baseline, post-intervention and post-3-month follow-up using the Neurobehavioral Cognitive Status Examination (NCSE), Verbal Fluency Test (VFT), Chinese Version Verbal Learning Test (CVVLT), Lawton Instrumental Activities of Daily Living Scale (Lawton IADL) and Problems in Everyday Living test (PEDL). Data were analysed using a repeated-measures analysis of variance. Cohen's d effect size was used to assess the practical significant effects. The participants showed significant improvement in NCSE composite score, VFT, CVVLT total free recall, CVVLT 10-minute delayed free recall, Lawton IADL and PEDL. Results of this study demonstrate that the newly designed functional task exercise programme, which uses simulated tasks, is feasible and beneficial to cognitive functions and functional status of older persons with MCI. The findings of the current study further reinforce occupational therapy practitioners' understanding that "occupation" is a "means" and an "end". Further study with a larger population is needed to draw more definitive conclusions. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Effects of Physical-Cognitive Dual Task Training on Executive Function and Gait Performance in Older Adults: A Randomized Controlled Trial.

    Science.gov (United States)

    Falbo, S; Condello, G; Capranica, L; Forte, R; Pesce, C

    2016-01-01

    Physical and cognitive training seem to counteract age-related decline in physical and mental function. Recently, the possibility of integrating cognitive demands into physical training has attracted attention. The purpose of this study was to evaluate the effects of twelve weeks of designed physical-cognitive training on executive cognitive function and gait performance in older adults. Thirty-six healthy, active individuals aged 72.30 ± 5.84 years were assigned to two types of physical training with major focus on physical single task (ST) training (n = 16) and physical-cognitive dual task (DT) training (n = 20), respectively. They were tested before and after the intervention for executive function (inhibition, working memory) through Random Number Generation and for gait (walking with/without negotiating hurdles) under both single and dual task (ST, DT) conditions. Gait performance improved in both groups, while inhibitory performance decreased after exercise training with ST focus but tended to increase after training with physical-cognitive DT focus. Changes in inhibition performance were correlated with changes in DT walking performance with group differences as a function of motor task complexity (with/without hurdling). The study supports the effectiveness of group exercise classes for older individuals to improve gait performance, with physical-cognitive DT training selectively counteracting the age-related decline in a core executive function essential for daily living.

  15. Functional and Neuroanatomic Specificity of Episodic Memory Dysfunction in Schizophrenia: A Functional Magnetic Resonance Imaging Study of the Relational and Item-Specific Encoding Task.

    Science.gov (United States)

    Ragland, J Daniel; Ranganath, Charan; Harms, Michael P; Barch, Deanna M; Gold, James M; Layher, Evan; Lesh, Tyler A; MacDonald, Angus W; Niendam, Tara A; Phillips, Joshua; Silverstein, Steven M; Yonelinas, Andrew P; Carter, Cameron S

    2015-09-01

    Individuals with schizophrenia can encode item-specific information to support familiarity-based recognition but are disproportionately impaired encoding interitem relationships (relational encoding) and recollecting information. The Relational and Item-Specific Encoding (RiSE) paradigm has been used to disentangle these encoding and retrieval processes, which may depend on specific medial temporal lobe (MTL) and prefrontal cortex (PFC) subregions. Functional magnetic resonance (fMRI) imaging during RiSE task performance could help to specify dysfunctional neural circuits in schizophrenia that can be targeted for interventions to improve memory and functioning in the illness. To use fMRI to test the hypothesis that schizophrenia disproportionately affects MTL and PFC subregions during relational encoding and retrieval relative to item-specific memory processes, and to use fMRI results from healthy individuals serving as controls to establish neural construct validity for RiSE. This multisite, case-control, cross-sectional fMRI study was conducted between November 1, 2010, and May 30, 2012, at 5 Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia sites. The final sample included 52 outpatients with clinically stable schizophrenia and 57 demographically matched healthy control participants. Data analysis was performed between February 1, 2013, and May 30, 2014. Behavioral performance speed and accuracy (d') on item recognition and associative recognition tasks. Voxelwise statistical parametric maps for a priori MTL and PFC regions of interest to test activation differences between relational and item-specific memory during encoding and retrieval. Item recognition was disproportionately impaired in patients with schizophrenia relative to healthy control participants following relational encoding (F1,107 = 4.7; P = .03). The differential deficit was accompanied by reduced dorsolateral PFC activation during relational encoding in

  16. Virtual/Real Transfer in a Large-Scale Environment: Impact of Active Navigation as a Function of the Viewpoint Displacement Effect and Recall Tasks

    Directory of Open Access Journals (Sweden)

    Grégory Wallet

    2013-01-01

    Full Text Available The purpose of this study was to examine the effect of navigation mode (passive versus active on the virtual/real transfer of spatial learning, according to viewpoint displacement (ground: 1 m 75 versus aerial: 4 m and as a function of the recall tasks used. We hypothesize that active navigation during learning can enhance performances when route strategy is favored by egocentric match between learning (ground-level viewpoint and recall (egocentric frame-based tasks. Sixty-four subjects (32 men and 32 women participated in the experiment. Spatial learning consisted of route learning in a virtual district (four conditions: passive/ground, passive/aerial, active/ground, or active/aerial, evaluated by three tasks: wayfinding, sketch-mapping, and picture-sorting. In the wayfinding task, subjects who were assigned the ground-level viewpoint in the virtual environment (VE performed better than those with the aerial-level viewpoint, especially in combination with active navigation. In the sketch-mapping task, aerial-level learning in the VE resulted in better performance than the ground-level condition, while active navigation was only beneficial in the ground-level condition. The best performance in the picture-sorting task was obtained with the ground-level viewpoint, especially with active navigation. This study confirmed the expected results that the benefit of active navigation was linked with egocentric frame-based situations.

  17. The effect of task complexity on functional adequacy, fluency and lexical diversity in speaking performances of native and non-native speakers

    NARCIS (Netherlands)

    de Jong, N.H.; Steinel, M.P.; Florijn, A.; Schoonen, R.; Hulstijn, J.H.; Housen, A.; Kuiken, F.; Vedder, I.

    2012-01-01

    This study investigated how task complexity affected native and non-native speakers’ speaking performance in terms of a measure of communicative success (functional adequacy), three types of fluency (breakdown fluency, speed fluency, and repair fluency), and lexical diversity. Participants (208 non-

  18. Effects of Repetitive Transcranial Magnetic Stimulation in Performing Eye-Hand Integration Tasks: Four Preliminary Studies with Children Showing Low-Functioning Autism

    Science.gov (United States)

    Panerai, Simonetta; Tasca, Domenica; Lanuzza, Bartolo; Trubia, Grazia; Ferri, Raffaele; Musso, Sabrina; Alagona, Giovanna; Di Guardo, Giuseppe; Barone, Concetta; Gaglione, Maria P.; Elia, Maurizio

    2014-01-01

    This report, based on four studies with children with low-functioning autism, aimed at evaluating the effects of repetitive transcranial magnetic stimulation delivered on the left and right premotor cortices on eye-hand integration tasks; defining the long-lasting effects of high-frequency repetitive transcranial magnetic stimulation; and…

  19. Merging clinical neuropsychology and functional neuroimaging to evaluate the construct validity and neural network engagement of the n-back task.

    Science.gov (United States)

    Kearney-Ramos, Tonisha E; Fausett, Jennifer S; Gess, Jennifer L; Reno, Ashley; Peraza, Jennifer; Kilts, Clint D; James, G Andrew

    2014-08-01

    The n-back task is a widely used neuroimaging paradigm for studying the neural basis of working memory (WM); however, its neuropsychometric properties have received little empirical investigation. The present study merged clinical neuropsychology and functional magnetic resonance imaging (fMRI) to explore the construct validity of the letter variant of the n-back task (LNB) and to further identify the task-evoked networks involved in WM. Construct validity of the LNB task was investigated using a bootstrapping approach to correlate LNB task performance across clinically validated neuropsychological measures of WM to establish convergent validity, as well as measures of related but distinct cognitive constructs (i.e., attention and short-term memory) to establish discriminant validity. Independent component analysis (ICA) identified brain networks active during the LNB task in 34 healthy control participants, and general linear modeling determined task-relatedness of these networks. Bootstrap correlation analyses revealed moderate to high correlations among measures expected to converge with LNB (|ρ|≥ 0.37) and weak correlations among measures expected to discriminate (|ρ|≤ 0.29), controlling for age and education. ICA identified 35 independent networks, 17 of which demonstrated engagement significantly related to task condition, controlling for reaction time variability. Of these, the bilateral frontoparietal networks, bilateral dorsolateral prefrontal cortices, bilateral superior parietal lobules including precuneus, and frontoinsular network were preferentially recruited by the 2-back condition compared to 0-back control condition, indicating WM involvement. These results support the use of the LNB as a measure of WM and confirm its use in probing the network-level neural correlates of WM processing.

  20. Optimizing and Interpreting Insular Functional Connectivity Maps Obtained During Acute Experimental Pain: The Effects of Global Signal and Task Paradigm Regression.

    Science.gov (United States)

    Ibinson, James W; Vogt, Keith M; Taylor, Kevin B; Dua, Shiv B; Becker, Christopher J; Loggia, Marco; Wasan, Ajay D

    2015-12-01

    The insula is uniquely located between the temporal and parietal cortices, making it anatomically well-positioned to act as an integrating center between the sensory and affective domains for the processing of painful stimulation. This can be studied through resting-state functional connectivity (fcMRI) imaging; however, the lack of a clear methodology for the analysis of fcMRI complicates the interpretation of these data during acute pain. Detected connectivity changes may reflect actual alterations in low-frequency synchronous neuronal activity related to pain, may be due to changes in global cerebral blood flow or the superimposed task-induced neuronal activity. The primary goal of this study was to investigate the effects of global signal regression (GSR) and task paradigm regression (TPR) on the changes in functional connectivity of the left (contralateral) insula in healthy subjects at rest and during acute painful electric nerve stimulation of the right hand. The use of GSR reduced the size and statistical significance of connectivity clusters and created negative correlation coefficients for some connectivity clusters. TPR with cyclic stimulation gave task versus rest connectivity differences similar to those with a constant task, suggesting that analysis which includes TPR is more accurately reflective of low-frequency neuronal activity. Both GSR and TPR have been inconsistently applied to fcMRI analysis. Based on these results, investigators need to consider the impact GSR and TPR have on connectivity during task performance when attempting to synthesize the literature.

  1. The ELLIPTA® Dry Powder Inhaler: Design, Functionality, In Vitro Dosing Performance and Critical Task Compliance by Patients and Caregivers.

    Science.gov (United States)

    Grant, Andrew C; Walker, Richard; Hamilton, Melanie; Garrill, Karl

    2015-12-01

    Dry powder inhalers (DPIs) are commonly used for the delivery of inhaled medications, and should provide consistent, efficient dosing, be easy to use correctly, and be liked by patients; these attributes can all affect patient compliance and therefore treatment efficacy. The ELLIPTA(®) DPI was developed for the delivery of once-daily therapies for the treatment of asthma and chronic obstructive pulmonary disease. It has moderate resistance to airflow and can hold one or two blister strips, with each blister containing a sealed single dose of medication. Monotherapies can be delivered by the single-strip configuration and, in the two-strip configuration, one dose from each strip can be aerosolized simultaneously to allow combination therapies to be delivered, which enables the formulations for each product to be developed individually, since they are stored separately until the point of administration. There are three principal operating steps to administer a dose: open, inhale, close. This article summarizes the design, functionality, and in vitro dose-delivery characteristics of the ELLIPTA inhaler, and describes the results of human factors validation tests, designed to assess the performance of critical tasks required to use the inhaler. Results from the in vitro studies indicate that the ELLIPTA inhaler performs consistently with respect to in vitro dose delivery characteristics at a range of flow rates that can be achieved by the target population (≥30 L/min) and over its 30-day in-use life. Data from the human factors validation tests demonstrated that almost all participants (≥97%) were able to complete each of the steps required to prepare a dose for inhalation without error. Overall, the ELLIPTA inhaler has a versatile single- or two-strip design that allows it to be used for the delivery of a range of treatment options. It also improves patient ease-of-use when compared with the DISKUS(®) DPI.

  2. Working memory activation of neural networks in the elderly as a function of information processing phase and task complexity.

    Science.gov (United States)

    Charroud, Céline; Steffener, Jason; Le Bars, Emmanuelle; Deverdun, Jérémy; Bonafe, Alain; Abdennour, Meriem; Portet, Florence; Molino, François; Stern, Yaakov; Ritchie, Karen; Menjot de Champfleur, Nicolas; Akbaraly, Tasnime N

    2015-11-01

    Changes in working memory are sensitive indicators of both normal and pathological brain aging and associated disability. The present study aims to further understanding of working memory in normal aging using a large cohort of healthy elderly in order to examine three separate phases of information processing in relation to changes in task load activation. Using covariance analysis, increasing and decreasing neural activation was observed on fMRI in response to a delayed item recognition task in 337 cognitively healthy elderly persons as part of the CRESCENDO (Cognitive REServe and Clinical ENDOphenotypes) study. During three phases of the task (stimulation, retention, probe), increased activation was observed with increasing task load in bilateral regions of the prefrontal cortex, parietal lobule, cingulate gyrus, insula and in deep gray matter nuclei, suggesting an involvement of central executive and salience networks. Decreased activation associated with increasing task load was observed during the stimulation phase, in bilateral temporal cortex, parietal lobule, cingulate gyrus and prefrontal cortex. This spatial distribution of decreased activation is suggestive of the default mode network. These findings support the hypothesis of an increased activation in salience and central executive networks and a decreased activation in default mode network concomitant to increasing task load.

  3. Visual overview, oral detail

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2015-01-01

    and with the coordinating nurse, who is the main keeper of the whiteboard. On the basis of observations, we find that coordination is accomplished through a highly intertwined process of technologically mediated visual overview combined with orally communicated details. The oral details serve to clarify and elaborate...

  4. LOCKE Detailed Specification Tables

    CERN Document Server

    Menezo, Lucia G; Gregorio, Jose-Angel

    2012-01-01

    This document shows the detailed specification of LOCKE coherence protocol for each cache controller, using a table-based technique. This representation provides clear, concise visual information yet includes sufficient detail (e.g., transient states) arguably lacking in the traditional, graphical form of state diagrams.

  5. Detail and survey radioautographs

    Energy Technology Data Exchange (ETDEWEB)

    Wainwright, Wm.W.

    1949-04-19

    The much used survey or contact type of radioautograph is indispensible for a study of the gross distribution of radioactive materials. A detail radioautograph is equally indispensible. The radioautograph makes possible the determination of plutonium with respect to cells. Outlines of survey and detail techniques are given.

  6. Lower extremity muscle activation and function in progressive task-oriented training on the supplementary tilt table during stepping-like movements in patients with acute stroke hemiparesis.

    Science.gov (United States)

    Kim, Chang-Yong; Lee, Jung-Sun; Kim, Hyeong-Dong; Kim, Junesun; Lee, In-Hak

    2015-06-01

    An effective and standardized method for applying a tilt table as a supplementary treatment in the early rehabilitation of stroke patients is still missing. The aim of this study was to determine the influence of progressive task-oriented training on the tilt table on the improvement in lower extremity (LE) muscle activation and clinical function in subjects with hemiplegia due to stroke. Thirty-nine subjects with acute stroke were randomly allocated to three groups; control group, tilt table group, and task-oriented training group on the tilt table, with 13 patients, respectively. All of the subjects received the routine therapy for half an hour, and subjects in the experimental groups additionally received training on two different tilt table applications for 20min a day, five times a week for three weeks. The effect of tilt table applications was assessed using the surface electromyography (EMG) analysis during stepping-like movements on the tilt table for LE muscle activation and clinical scores for function. Our results showed that there was a significantly greater increase in the EMG patterns of the extensors and flexors of the affected leg muscles during flexion and extension movements of both legs and clinical scores in patients undergoing the progressive task-oriented training on the tilt table compared to the other groups. These findings suggest that progressive task-oriented training on the tilt table can improve LE muscle activation and clinical scores of functional performance for early rehabilitation of subjects with acute stroke.

  7. Effects of mirror therapy integrated with task-oriented exercise on the balance function of patients with poststroke hemiparesis: a randomized-controlled pilot trial.

    Science.gov (United States)

    Cha, Hyun-Gyu; Oh, Duck-Won

    2016-03-01

    This study aimed to explore the effects of mirror therapy integrated with task-oriented exercise on balance function in poststroke hemiparesis. Twenty patients with poststroke hemiparesis were assigned randomly to an experimental group (EG) and a control group (CG), with 10 individuals each. Participants of the EG and CG received a task-oriented exercise program with a focus on the strengthening of the lower limb and the practice of balance-related functional tasks. An additional option for the EG was front and side wall mirrors to provide visual feedback for their own movements while performing the exercise. The program was performed for 30 min, twice a day, five times per week for 4 weeks. Outcome measures included the Berg balance scale, the timed up-and-go test, and quantitative data (balance index and dynamic limits of stability). In the EG and CG, all variables showed significant differences between pretest and post-test (Pmirror therapy may be used as a beneficial therapeutic option to facilitate the effects of a task-oriented exercise on balance function of patients with poststroke hemiparesis.

  8. Goal Management Training and Mindfulness Meditation improve executive functions and transfer to ecological tasks of daily life in polysubstance users enrolled in therapeutic community treatment.

    Science.gov (United States)

    Valls-Serrano, Carlos; Caracuel, Alfonso; Verdejo-Garcia, Antonio

    2016-08-01

    We have previously shown that Goal Management Training+Mindfulness Meditation (GMT+MM) improves executive functions in polysubstance users enrolled in outpatient treatment. The aim of this study was to establish if GMT+MM has similar positive effects on executive functions in polysubstance users in residential treatment, and if executive functions' gains transfer to more ecologically valid goal-oriented tasks. Thirty-two polysbustance users were randomly allocated to eight weeks of GMT+MM (n=16) or control, i.e., no-intervention (n=16); both groups received treatment as usual. Outcome measures included performance in laboratory tasks of basic and complex executive functions (i.e., basic: working memory and inhibition; complex: planning and self-regulation) and in an ecological task of goal-directed behavior (the Multiple Errands Test - contextualized version, MET-CV) measured post-interventions. Results showed that GMT+MM was superior to control in improving basic measures of working memory (Letter-number sequencing; F=4.516, p=0.049) and reflection impulsivity (Information Sampling Test; F=6.217, p=0.018), along with initial thinking times during planning (Zoo Map Test; F=8.143, p=0.008). In addition, GMT+MM was superior to control in improving performance in the MET-CV (task failures; F=8.485, p=0.007). Our findings demonstrate that GMT+MM increases reflective processes and the achievement of goals in daily activities, furthermore ecological test can detects changes easily than laboratory tasks. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. The neural pathway underlying a numerical working memory task in abacus-trained children and associated functional connectivity in the resting brain.

    Science.gov (United States)

    Li, Yongxin; Hu, Yuzheng; Zhao, Ming; Wang, Yunqi; Huang, Jian; Chen, Feiyan

    2013-11-20

    Training can induce significant changes in brain functioning and behavioral performance. One consequence of training is changing the pattern of brain activation. Abacus training is of interest because abacus experts gain the ability to handle digits with unusual speed and accuracy. However, the neural correlates of numerical memory in abacus-trained children remain unknown. In the current study, we aimed to detect a training effect of abacus-based mental calculations on numerical working memory in children. We measured brain functional magnetic resonance imaging (fMRI) activation patterns in 17 abacus-trained children and 17 control children as they performed two numerical working memory tasks (digits and beads). Functional MRI results revealed higher activation in abacus-trained children than in the controls in the right posterior superior parietal lobule/superior occipital gyrus (PSPL/SOG) and the right supplementary motor area (SMA) in both tasks. When these regions were used as seeds in a functional connectivity analysis of the resting brain, the abacus-trained children showed significantly enhanced integration between the right SMA and the right inferior frontal gyrus (IFG). The IFG is considered to be the key region for the control of attention. These findings demonstrate that extensive engagement of the fronto-parietal network occurs during numerical memory tasks in the abacus-trained group. Furthermore, abacus training may increase the functional integration of visuospatial-attention circuitry, which and thus enhances high-level cognitive process.

  10. A Problem-Solving Task Specialized for Functional Neuroimaging: Validation of the Scarborough adaptation of the Tower of London (S-TOL using Near-Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Anthony Charles Ruocco

    2014-03-01

    Full Text Available Problem-solving is an executive function subserved by a network of neural structures of which the dorsolateral prefrontal cortex (DLPFC is central. Whereas several studies have evaluated the role of the DLPFC in problem-solving, few standardized tasks have been developed specifically for use with functional neuroimaging. The current study adapted a measure with established validity for the assessment of problem-solving abilities to design a test more suitable for functional neuroimaging protocols. The Scarborough adaptation of the Tower of London (S-TOL was administered to 38 healthy adults while hemodynamic oxygenation of the PFC was measured using 16-channel continuous-wave functional near-infrared spectroscopy. Compared to a baseline condition, problems that required two or three steps to achieve a goal configuration were associated with higher activation in the left DLPFC and deactivation in the medial PFC. Individuals scoring higher in trait deliberation showed consistently higher activation in the left DLPFC regardless of task difficulty, whereas individuals lower in this trait displayed less activation when solving simple problems. Based on these results, the S-TOL may serve as a standardized task to evaluate problem-solving abilities in functional neuroimaging studies.

  11. A problem-solving task specialized for functional neuroimaging: validation of the Scarborough adaptation of the Tower of London (S-TOL) using near-infrared spectroscopy.

    Science.gov (United States)

    Ruocco, Anthony C; Rodrigo, Achala H; Lam, Jaeger; Di Domenico, Stefano I; Graves, Bryanna; Ayaz, Hasan

    2014-01-01

    Problem-solving is an executive function subserved by a network of neural structures of which the dorsolateral prefrontal cortex (DLPFC) is central. Whereas several studies have evaluated the role of the DLPFC in problem-solving, few standardized tasks have been developed specifically for use with functional neuroimaging. The current study adapted a measure with established validity for the assessment of problem-solving abilities to design a test more suitable for functional neuroimaging protocols. The Scarborough adaptation of the Tower of London (S-TOL) was administered to 38 healthy adults while hemodynamic oxygenation of the PFC was measured using 16-channel continuous-wave functional near-infrared spectroscopy (fNIRS). Compared to a baseline condition, problems that required two or three steps to achieve a goal configuration were associated with higher activation in the left DLPFC and deactivation in the medial PFC. Individuals scoring higher in trait deliberation showed consistently higher activation in the left DLPFC regardless of task difficulty, whereas individuals lower in this trait displayed less activation when solving simple problems. Based on these results, the S-TOL may serve as a standardized task to evaluate problem-solving abilities in functional neuroimaging studies.

  12. Targeted brain activation using an MR-compatible wrist torque measurement device and isometric motor tasks during functional magnetic resonance imaging.

    Science.gov (United States)

    Vlaar, Martijn P; Mugge, Winfred; Groot, Paul F C; Sharifi, Sarvi; Bour, Lo J; van der Helm, Frans C T; van Rootselaar, Anne-Fleur; Schouten, Alfred C

    2016-07-01

    Dedicated pairs of isometric wrist flexion tasks, with and without visual feedback of the exerted torque, were designed to target activation of the CBL and BG in healthy subjects during functional magnetic resonance imaging (fMRI). Selective activation of the cerebellum (CBL) and basal ganglia (BG), often implicated in movement disorders such as tremor and dystonia, may help identify pathological changes and expedite diagnosis. A prototyped MR-compatible wrist torque measurement device, free of magnetic and conductive materials, allowed safe execution of tasks during fMRI without causing artifacts. A significant increase of activity in CBL and BG was found in healthy volunteers during a constant torque task with visual feedback compared to a constant torque task without visual feedback. This study shows that specific pairs of motor tasks using MR-compatible equipment at the wrist allow for targeted activation of CBL and BG, paving a new way for research into the pathophysiology of movement disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Mathematically gifted adolescents use more extensive and more bilateral areas of the fronto-parietal network than controls during executive functioning and fluid reasoning tasks.

    Science.gov (United States)

    Desco, Manuel; Navas-Sanchez, Francisco J; Sanchez-González, Javier; Reig, Santiago; Robles, Olalla; Franco, Carolina; Guzmán-De-Villoria, Juan A; García-Barreno, Pedro; Arango, Celso

    2011-07-01

    The main goal of this study was to investigate the neural substrates of fluid reasoning and visuospatial working memory in adolescents with precocious mathematical ability. The study population comprised two groups of adolescents: 13 math-gifted adolescents and 14 controls with average mathematical skills. Patterns of activation specific to reasoning tasks in math-gifted subjects were examined using functional magnetic resonance images acquired while the subjects were performing Raven's Advanced Progressive Matrices (RAPM) and the Tower of London (TOL) tasks. During the tasks, both groups showed significant activations in the frontoparietal network. In the math-gifted group, clusters of activation were always bilateral and more regions were recruited, especially in the right hemisphere. In the TOL task, math-gifted adolescents showed significant hyper-activations relative to controls in the precuneus, superior occipital lobe (BA 19), and medial temporal lobe (BA 39). The maximum differences between the groups were detected during RAPM tasks at the highest level of difficulty, where math-gifted subjects showed significant activations relative to controls in the right inferior parietal lobule (BA 40), anterior cingulated gyrus (BA 32), and frontal (BA 9, and BA 6) areas. Our results support the hypothesis that greater ability for complex mathematical reasoning may be related to more bilateral patterns of activation and that increased activation in the parietal and frontal regions of math-gifted adolescents is associated with enhanced skills in visuospatial processing and logical reasoning.

  14. Detailed Soils 24K

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set is a digital soil survey and is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The information was...

  15. Predicting Growth in Word Level Reading Skills in Children With Developmental Dyslexia Using an Object Rhyming Functional Neuroimaging Task.

    Science.gov (United States)

    Farris, Emily A; Ring, Jeremiah; Black, Jeffrey; Lyon, G Reid; Odegard, Timothy N

    2016-04-01

    An object rhyming task that does not require text reading and is suitable for younger children was used to predict gains in word level reading skills following an intensive 2-year reading intervention for children with developmental dyslexia. The task evoked activation in bilateral inferior frontal regions. Growth in untimed pseudoword reading was associated with increased pre-intervention activation of the left inferior frontal gyrus, and growth in timed word reading was associated with pre-intervention activation of the left and right inferior frontal gyri. These analyses help identify pre-intervention factors that facilitate reading skill improvements in children with developmental dyslexia.

  16. Altered spinal kinematics and muscle recruitment pattern of the cervical and thoracic spine in people with chronic neck pain during functional task.

    Science.gov (United States)

    Tsang, Sharon M H; Szeto, Grace P Y; Lee, Raymond Y W

    2014-02-01

    Knowledge on the spinal kinematics and muscle activation of the cervical and thoracic spine during functional task would add to our understanding of the performance and interplay of these spinal regions during dynamic condition. The purpose of this study was to examine the influence of chronic neck pain on the three-dimensional kinematics and muscle recruitment pattern of the cervical and thoracic spine during an overhead reaching task involving a light weight transfer by the upper limb. Synchronized measurements of the three-dimensional spinal kinematics and electromyographic activities of cervical and thoracic spine were acquired in thirty individuals with chronic neck pain and thirty age- and gender-matched asymptomatic controls. Neck pain group showed a significantly decreased cervical velocity and acceleration while performing the task. They also displayed with a predominantly prolonged coactivation of cervical and thoracic muscles throughout the task cycle. The current findings highlighted the importance to examine differential kinematic variables of the spine which are associated with changes in the muscle recruitment in people with chronic neck pain. The results also provide an insight to the appropriate clinical intervention to promote the recovery of the functional disability commonly reported in patients with neck pain disorders.

  17. Gender-specific cerebral activation during cognitive tasks using functional MRI: comparison of women in mid-luteal phase and men

    Energy Technology Data Exchange (ETDEWEB)

    Gizewski, Elke R.; Wanke, Isabel; Forsting, Michael [University Hospital Essen, Departments of Diagnostic and Interventional Neuroradiology, Essen (Germany); Krause, Eva; Senf, Wolfgang [University Hospital Essen, Department of Psychosomatic Medicine, Essen (Germany)

    2006-01-01

    Previous studies of gender-specific differences in functional imaging during spatial and language tasks have been inconclusive. Furthermore, among women, such differences may occur during mid-luteal phase compared to the rest of the menstrual cycle. In order to examine further gender differences, functional MRI was performed in 12 male volunteers and 12 female volunteers (in the mid-luteal phase) during mental rotation and verb-generation tests. Two-sample t-tests with uncorrected P values of <0.001 for the specific regions of interest (ROIs) revealed cerebral activation differences in both stimuli. During mental rotation tests, higher levels of activation were noted in the right medial frontal, precentral, and bilateral inferior parietal cortex, while in women this occurred in the right inferior and medial temporal, right superior frontal cortex, and left fusiform gyrus. During verb-generation tests, higher levels of activation in men was found in the left medial temporal and precentral cortex. Our results indicate that differences in cerebral activity during cognitive tasks can be shown between men and women in the mid-luteal phase. Gender differences while performing a mental rotation task were more prominent than during a verb-generation task. (orig.)

  18. 基于评价函数的动态协同任务调度算法%Evaluation function-based dynamic collaboration task scheduling algorithm

    Institute of Scientific and Technical Information of China (English)

    王璇; 颜景龙

    2011-01-01

    As the problems that resources change dynamically and tasks access in complex grid environment,a dynamic collaboration task scheduling based on the evaluation function was proposed.This algorithm solves the task cooperation scheduling in dynamic grid by using evaluation function of tasks and collaborators,which vary with time.Compared with distributed cooperation scheduling algorithm based on contract net,theoretical analysis and experimental results show that the algorithm is effective to reduce the system overhead and improve the resource allocation.%针对复杂网格环境中节点资源动态变化及大量任务协作访问的问题,提出一种基于评价函数的动态协作任务调度算法.该算法通过为网格中的协作任务与协作成员建立随时间变化的任务评价函数和协作成员评价函数,实现动态网格环境中的任务协同调度.理论分析与仿真实验表明:与基于合同网的分布式合作调度算法相比,本算法能够减小系统开销,提高资源分配效率.

  19. Acquisition of a Complex Basketball-Dribbling Task in School Children as a Function of Bilateral Practice Order

    Science.gov (United States)

    Stockel, Tino; Weigelt, Matthias; Krug, Jurgen

    2011-01-01

    The purpose of this study was to investigate order-of-practice effects for the acquisition of a complex basketball skill in a bilateral transfer paradigm. The task required participants to dribble as fast as possible in slalom-like movements across six javelins and return to the initial position. Fifty-two right-handed school children (M age =…

  20. Delayed response task performance as a function of age in cynomolgus monkeys (Macaca fascicularis)

    DEFF Research Database (Denmark)

    Darusman, H S; Call, J; Sajuthi, D

    2014-01-01

    We compared delayed response task performance in young, middle-aged, and old cynomolgus monkeys using three memory tests that have been used with non-human primates. Eighteen cynomolgus monkeys-6 young (4-9 years), 6 middle-aged (10-19 years), and 6 old (above 20 years)-were tested. In general...

  1. Acquisition of a Complex Basketball-Dribbling Task in School Children as a Function of Bilateral Practice Order

    Science.gov (United States)

    Stockel, Tino; Weigelt, Matthias; Krug, Jurgen

    2011-01-01

    The purpose of this study was to investigate order-of-practice effects for the acquisition of a complex basketball skill in a bilateral transfer paradigm. The task required participants to dribble as fast as possible in slalom-like movements across six javelins and return to the initial position. Fifty-two right-handed school children (M age =…

  2. A rigorous model of reflex function indicates that position and force feedback are flexibly tuned to position and force tasks

    NARCIS (Netherlands)

    Mugge, W.; Abbink, D.A.; Schouten, A.C.; Dewald, J.P.A.; Van der Helm, F.C.T.

    2009-01-01

    This study aims to quantify the separate contributions of muscle force feedback, muscle spindle activity and co-contraction to the performance of voluntary tasks (‘‘reduce the influence of perturbations on maintained force or position’’). Most human motion control studies either isolate only one con

  3. Interference Effects as a Function of Semantic Similarity in the Translation Recognition Task in Bilinguals of Catalan and Spanish

    Science.gov (United States)

    Moldovan, Cornelia D.; Sanchez-Casas, Rosa; Demestre, Josep; Ferre, Pilar

    2012-01-01

    Previous evidence has shown that word pairs that are either related in form (e.g., "ruc-berro"; donkey-watercress) or very closely semantically related (e.g., "ruc-caballo", donkey-horse) produce interference effects in a translation recognition task (Ferre et al., 2006; Guasch et al., 2008). However, these effects are not…

  4. A novel CMPO-functionalized task specific ionic liquid: Synthesis, extraction and spectroscopic investigations of actinide and lanthanide complexes

    NARCIS (Netherlands)

    Mohapatra, P.K.; Kandwal, P.; Iqbal, M.; Huskens, Jurriaan; Murali, M.S.; Verboom, Willem

    2013-01-01

    A novel CMPO (carbamoylmethylphosphine oxide) based task specific ionic liquid (TSIL) with an NTf2− counter anion was synthesized and evaluated for actinide/lanthanide extraction from acidic feed solutions using several room temperature ionic liquids (RTILs). The extraction data were compared with

  5. Abnormal function of the posterior cingulate cortex in heroin addicted users during resting-state and drug-cue stimulation task

    Institute of Scientific and Technical Information of China (English)

    LI Qiang; YANG Wei-chuan; WANG Ya-rong; HUANG Yu-fang; LI Wei; ZHU Jia

    2013-01-01

    Background Previous animal and neuroimaging studies have demonstrated that brain function in heroin addicted users is impaired.However,the posterior cingulate cortex (PCC) has not received much attention.The purpose of this study was to investigate whether chronic heroin use is associated with craving-related changes in the functional connectivity of the PCC of heroin addicted users.Methods Fourteen male adult chronic heroin users and fifteen age and gender-matched healthy subjects participated in the present study.The participants underwent a resting-state functional magnetic resonance imaging (fMRI) scan and a cue-induced craving task fMRI scan.The activated PCC was identified in the cue-induced craving task by means of a group contrast test.Functional connectivity was analyzed based on resting-state fMRI data in order to determine the correlation between brain regions.The relationship between the connectivity of specific regions and heroin dependence was investigated.Results The activation of PCC,bilateral anterior cingulate cortex,caudate,putamen,precuneus,and thalamus was significant in the heroin group compared to the healthy group in the cue-induced craving task.The detectable functional connectivity of the heroin users was stronger between the PCC and bilateral insula,bilateral dorsal striatum,right inferior parietal Iobule (IPL) and right supramarginal gyrus (P<0.001) compared to that of the healthy subjects in the resting-state data analysis.The strength of the functional connectivity,both for the PCC-insula (r=0.60,P <0.05) and for PCC-striatum (r=0.58,P<0.05),was positively correlated with the duration of heroin use.Conclusion The altered functional connectivity patterns in the PCC-insula and PCC-striatum areas may be regarded as biomarkers of brain damage severity in chronic heroin users.

  6. Task 1 quarternary tectonics

    Energy Technology Data Exchange (ETDEWEB)

    Bell, J.W.

    1994-12-31

    Activities on the task of quarternary tectonics for the Yucca Mountain Site investigations are described. Technical topics include: A preliminary reveiw of Bare Mountain Trench; A preliminary detailed lineament map of the Southwestern part of the proposed repository; A discussion on the 1994 Double Spring Flat, Nevada earthquake; and evidence for temporal clustering.

  7. Twelve weeks of BodyBalance® training improved balance and functional task performance in middle-aged and older adults

    Directory of Open Access Journals (Sweden)

    Nicholson VP

    2014-11-01

    Full Text Available Vaughan P Nicholson, Mark R McKean, Brendan J Burkett School of Health and Sport Sciences, University of the Sunshine Coast, Sunshine Coast, QLD, Australia Purpose: The purpose of the study was to evaluate the effect of BodyBalance® training on balance, functional task performance, fear of falling, and health-related quality of life in adults aged over 55 years.Participants and methods: A total of 28 healthy, active adults aged 66±5 years completed the randomized controlled trial. Balance, functional task performance, fear of falling, and self-reported quality of life were assessed at baseline and after 12 weeks. Participants either undertook two sessions of BodyBalance per week for 12 weeks (n=15 or continued with their normal activities (n=13.Results: Significant group-by-time interactions were found for the timed up and go (P=0.038, 30-second chair stand (P=0.037, and mediolateral center-of-pressure range in narrow stance with eyes closed (P=0.017. There were no significant effects on fear of falling or self-reported quality of life.Conclusion: Twelve weeks of BodyBalance training is effective at improving certain balance and functional based tasks in healthy older adults. Keywords: postural control, yoga, tai chi, center of pressure, exercise

  8. Three Latin Phonological Details

    DEFF Research Database (Denmark)

    Olsen, Birgit Anette

    2006-01-01

    The present paper deals with three minor details of Latin phonology: 1) the development of the initial sequence *u¿l¿-, where it is suggested that an apparent vacillation between ul- and vol-/vul- represents sandhi variants going back to the proto-language, 2) the adjectives ama¯rus ‘bitter' and ...

  9. Detailed functional characterization of glycosylated and nonglycosylated variants of malaria vaccine candidate PfAMA1 produced in Nicotiana benthamiana and analysis of growth inhibitory responses in rabbits.

    Science.gov (United States)

    Boes, Alexander; Spiegel, Holger; Edgue, Gueven; Kapelski, Stephanie; Scheuermayer, Matthias; Fendel, Rolf; Remarque, Edmond; Altmann, Friedrich; Maresch, Daniel; Reimann, Andreas; Pradel, Gabriele; Schillberg, Stefan; Fischer, Rainer

    2015-02-01

    One of the most promising malaria vaccine candidate antigens is the Plasmodium falciparum apical membrane antigen 1 (PfAMA1). Several studies have shown that this blood-stage antigen can induce strong parasite growth inhibitory antibody responses. PfAMA1 contains up to six recognition sites for N-linked glycosylation, a post-translational modification that is absent in P. falciparum. To prevent any potential negative impact of N-glycosylation, the recognition sites have been knocked out in most PfAMA1 variants expressed in eukaryotic hosts. However, N-linked glycosylation may increase efficacy by improving immunogenicity and/or focusing the response towards relevant epitopes by glycan masking. We describe the production of glycosylated and nonglycosylated PfAMA1 in Nicotiana benthamiana and its detailed characterization in terms of yield, integrity and protective efficacy. Both PfAMA1 variants accumulated to high levels (>510 μg/g fresh leaf weight) after transient expression, and high-mannose-type N-glycans were confirmed for the glycosylated variant. No significant differences between the N. benthamiana and Pichia pastoris PfAMA1 variants were detected in conformation-sensitive ligand-binding studies. Specific titres of >2 × 10(6) were induced in rabbits, and strong reactivity with P. falciparum schizonts was observed in immunofluorescence assays, as well as up to 100% parasite growth inhibition for both variants, with IC₅₀ values of ~35 μg/mL. Competition assays indicated that a number of epitopes were shielded from immune recognition by N-glycans, warranting further studies to determine how glycosylation can be used for the directed targeting of immune responses. These results highlight the potential of plant transient expression systems as a production platform for vaccine candidates.

  10. Detailed functional and structural phenotype of Bietti crystalline dystrophy associated with mutations in CYP4V2 complicated by choroidal neovascularization.

    Science.gov (United States)

    Fuerst, Nicole M; Serrano, Leona; Han, Grace; Morgan, Jessica I W; Maguire, Albert M; Leroy, Bart P; Kim, Benjamin J; Aleman, Tomas S

    2016-12-01

    To describe in detail the phenotype of a patient with Bietti crystalline dystrophy (BCD) complicated by choroidal neovascularization (CNV) and the response to intravitreal Bevacizumab (Avastin(®); Genentech/Roche). A 34-year-old woman with BCD and mutations in CYP4V2 (c.802-8_806del13/p.H331P:c992A>C) underwent a complete ophthalmic examination, full-field flash electroretinography (ERG), kinetic and two-color dark-adapted perimetry, and dark-adaptometry. Imaging was performed with spectral domain optical coherence tomography (SD-OCT), near infrared (NIR) and short wavelength (SW) fundus autofluorescence (FAF), and fluorescein angiography (FA). Best-corrected visual acuity (BCVA) was 20/20 and 20/60 for the right and left eye, respectively. There were corneal paralimbal crystal-like deposits. Kinetic fields were normal in the peripheral extent. Retinal crystals were most obvious on NIR-reflectance and corresponded with hyperreflectivities within the RPE on SD-OCT. There was parafoveal/perifoveal hypofluorescence on SW-FAF and NIR-FAF. Rod > cone sensitivity loss surrounded fixation and extended to ~10° of eccentricity corresponding to regions of photoreceptor outer segment-retinal pigmented epithelium (RPE) interdigitation abnormalities. The outer nuclear layer was normal in thickness. Recovery of sensitivity following a ~76% rhodopsin bleach was normal. ERGs were normal. A subretinal hemorrhage in the left eye co-localized with elevation of the RPE on SD-OCT and leakage on FA, suggestive of CNV. Three monthly intravitreal injections of Bevacizumab led to restoration of BCVA to baseline (20/25). crystals in BCD were predominantly located within the RPE. Photoreceptor outer segment and apical RPE abnormalities underlie the relatively extensive retinal dysfunction observed in relatively early-stage BCD. Intravitreal Bevacizumab was effective in treating CNV in this setting.

  11. [Visual functions' detailed evaluating in patients with Sjögren's syndrome before and after intracanalicular implants' (Smart Plug) insertion--(first results)].

    Science.gov (United States)

    Hejcmanová, D; Nemcová, I; Slezák, R

    2006-05-01

    The aim of the study was to determine exact visual functions (log MAR [minimal angle of resolution] and CS [contrast sensitivity]) and to evaluate corneal topographic maps in patients with established (by means of laboratory and biopsy examinations) Sjogren's Syndrome, and to determine the difference in subjective symptoms before and after insertion of the intracanalicular implants as well. Twelve eyes (1 man, 6 women) with established Sjogren's syndrome were examined before and during two months after the insertion of the plugs. The best-corrected visual acuity (BCVA) was assessed on Landolt C rings optotypes. CS was measured on computer-controlled device (Neuroscientific Corp., U.S.A.) in 6 space-frequencies (0.74-29.55 c/deg). The corneal topographic changes (Keraton Opticon) were established by means of comparing total aberrations values before and after the intracanalicular implants' (Smart Plugs type) insertion. The control group for visual functions assessment consisted of 10 woman (20 eyes) of similar middle age. The BCVA on log MAR optotypes was 0.84 (0.69-0.95) before and 0.88 (0.52-1.23) after the insertion, on both occasions, it was lower than in the control group. The CS was before the insertion in all of the spatial frequencies lower, the largest differences were in the frequencies range 1.97-7.29 c/deg (p visual functions in "dry eyes". The measurement of the corneal topography is useful in differential diagnosis and helps to distinguish mild and more serious conditions of dry eye. The improvement of BCVA and CS values after insertion corresponds with patients' subjective evaluating. The best value of the treatment is improvement of the patients' comfort; furthermore, after insertion of the permanent plugs they feel pronounced subjective relief and lowering of the frequency of drops application.

  12. The effect of practical cooling strategies on physiological response and cognitive function during simulated firefighting tasks in a smoke-diving room

    Directory of Open Access Journals (Sweden)

    Rasoul Hemmatjo

    2017-03-01

    significantly higher at the end of the activity in the CG+CV and CV compared with the CG and NC conditions. Conclusion: It is concluded that strenuous firefighting tasks have a detrimental effect on firefighters’ physiological responses and cognitive function. The findings also revealed that CV was more effective than the CG in attenuating physiological responses and cognitive function during firefighting operations. Furthermore, combining CV with CG provides no additional benefit. It is concluded that cooling the body by the use of CV offered physiological and psychological benefit for firefighters during simulated firefighting activities.

  13. Detailed dayside auroral morphology as a function of local time for southeast IMF orientation: implications for solar wind-magnetosphere coupling

    Directory of Open Access Journals (Sweden)

    P. E. Sandholt

    2004-11-01

    Full Text Available In two case studies we elaborate on spatial and temporal structures of the dayside aurora within 08:00-16:00 magnetic local time (MLT and discuss the relationship of this structure to solar wind-magnetosphere interconnection topology and the different stages of evolution of open field lines in the Dungey convection cycle. The detailed 2-D auroral morphology is obtained from continuous ground observations at Ny Ålesund (76° magnetic latitude (MLAT, Svalbard during two days when the interplanetary magnetic field (IMF is directed southeast (By>0; Bz<0. The auroral activity consists of the successive activations of the following forms: (i latitudinally separated, sunward moving, arcs/bands of dayside boundary plasma sheet (BPS origin, in the prenoon (08:00-11:00 MLT and postnoon (12:00-16:00 MLT sectors, within 70-75° MLAT, (ii poleward moving auroral forms (PMAFs emanating from the pre- and postnoon brightening events, and (iii a specific activity appearing in the 07:00-10:00 MLT/75-80° MLAT during the prevailing IMF By>0 conditions. The pre- and postnoon activations are separated by a region of strongly attenuated auroral activity/intensity within the 11:00-12:00 MLT sector, often referred to as the midday gap aurora. The latter aurora is attributed to the presence of component reconnection at the subsolar magnetopause where the stagnant magnetosheath flow lead to field-aligned currents (FACs which are of only moderate intensity. The much more active and intense aurorae in the prenoon (07:00-11:00 MLT and postnoon (12:00-16:00 MLT sectors originate in magnetopause reconnection events that are initiated well away from the subsolar point. The high-latitude auroral activity in the prenoon sector (feature iii is found to be accompanied by a convection channel at the polar cap boundary. The associated ground magnetic deflection (DPY is a Svalgaard-Mansurov effect. The convection channel is

  14. Brain functional network connectivity based on a visual task:visual information processing-related brain regions are signiifcantly activated in the task state

    Institute of Scientific and Technical Information of China (English)

    Yan-li Yang; Hong-xia Deng; Gui-yang Xing; Xiao-luan Xia; Hai-fang Li

    2015-01-01

    It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we inves-tigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state.Z-values in the vision-related brain regions were calculated, conifrming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental ifndings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

  15. Abnormal calcium homeostasis in heart failure with preserved ejection fraction is related to both reduced contractile function and incomplete relaxation: an electromechanically detailed biophysical modeling study

    Science.gov (United States)

    Adeniran, Ismail; MacIver, David H.; Hancox, Jules C.; Zhang, Henggui

    2015-01-01

    Heart failure with preserved ejection fraction (HFpEF) accounts for about 50% of heart failure cases. It has features of incomplete relaxation and increased stiffness of the left ventricle. Studies from clinical electrophysiology and animal experiments have found that HFpEF is associated with impaired calcium homeostasis, ion channel remodeling and concentric left ventricle hypertrophy (LVH). However, it is still unclear how the abnormal calcium homeostasis, ion channel and structural remodeling affect the electro-mechanical dynamics of the ventricles. In this study we have developed multiscale models of the human left ventricle from single cells to the 3D organ, which take into consideration HFpEF-induced changes in calcium handling, ion channel remodeling and concentric LVH. Our simulation results suggest that at the cellular level, HFpEF reduces the systolic calcium level resulting in a reduced systolic contractile force, but elevates the diastolic calcium level resulting in an abnormal residual diastolic force. In our simulations, these abnormal electro-mechanical features of the ventricular cells became more pronounced with the increase of the heart rate. However, at the 3D organ level, the ejection fraction of the left ventricle was maintained due to the concentric LVH. The simulation results of this study mirror clinically observed features of HFpEF and provide new insights toward the understanding of the cellular bases of impaired cardiac electromechanical functions in heart failure. PMID:25852567

  16. Abnormal calcium homeostasis in heart failure with preserved ejection fraction is related to both reduced contractile function and incomplete relaxation: An electromechanically detailed biophysical modelling study

    Directory of Open Access Journals (Sweden)

    Ismail eAdeniran

    2015-03-01

    Full Text Available Heart failure with preserved ejection fraction (HFpEF accounts for about 50% of heart failure cases. It has features of incomplete relaxation and increased stiffness of the left ventricle. Studies from clinical electrophysiology and animal experiments have found that HFpEF is associated with impaired calcium homeostasis, ion channel remodelling and concentric left ventricle hypertrophy (LVH. However, it is still unclear how the abnormal calcium homeostasis, ion channel and structural remodelling affect the electro-mechanical dynamics of the ventricles. In this study we have developed multiscale models of the human left ventricle from single cells to the 3D organ, which take into consideration HFpEF-induced changes in calcium handling, ion channel remodelling and concentric LVH. Our simulation results suggest that at the cellular level, HFpEF reduces the systolic calcium level resulting in a reduced systolic contractile force, but elevates the diastolic calcium level resulting in an abnormal residual diastolic force. In our simulations, these abnormal electro-mechanical features of the ventricular cells became more pronounced with the increase of the heart rate. However, at the 3D organ level, the ejection fraction of the left ventricle was maintained due to the concentric LVH. The simulation results of this study mirror clinically observed features of HFpEF and provide new insights towards the understanding of the cellular bases of impaired cardiac electromechanical functions in heart failure.

  17. Quantifying kinematics of purposeful movements to real, imagined, or absent functional objects: Implications for modelling trajectories for robot-assisted ADL tasks**

    Directory of Open Access Journals (Sweden)

    Wisneski Kimberly J

    2007-03-01

    Full Text Available Abstract Background Robotic therapy is at the forefront of stroke rehabilitation. The Activities of Daily Living Exercise Robot (ADLER was developed to improve carryover of gains after training by combining the benefits of Activities of Daily Living (ADL training (motivation and functional task practice with real objects, with the benefits of robot mediated therapy (repeatability and reliability. In combining these two therapy techniques, we seek to develop a new model for trajectory generation that will support functional movements to real objects during robot training. We studied natural movements to real objects and report on how initial reaching movements are affected by real objects and how these movements deviate from the straight line paths predicted by the minimum jerk model, typically used to generate trajectories in robot training environments. We highlight key issues that to be considered in modelling natural trajectories. Methods Movement data was collected as eight normal subjects completed ADLs such as drinking and eating. Three conditions were considered: object absent, imagined, and present. This data was compared to predicted trajectories generated from implementing the minimum jerk model. The deviations in both the plane of the table (XY and the saggital plane of torso (XZ were examined for both reaches to a cup and to a spoon. Velocity profiles and curvature were also quantified for all trajectories. Results We hypothesized that movements performed with functional task constraints and objects would deviate from the minimum jerk trajectory model more than those performed under imaginary or object absent conditions. Trajectory deviations from the predicted minimum jerk model for these reaches were shown to depend on three variables: object presence, object orientation, and plane of movement. When subjects completed the cup reach their movements were more curved than for the spoon reach. The object present condition for the cup

  18. Video feedback on functional task performance improves self-awareness after traumatic brain injury: a randomized controlled trial.

    Science.gov (United States)

    Schmidt, Julia; Fleming, Jennifer; Ownsworth, Tamara; Lannin, Natasha A

    2013-05-01

    Feedback is used in rehabilitation to improve self-awareness in people with traumatic brain injury (TBI), but there have been no comparisons of the different methods of providing feedback. To compare the effect of different methods of feedback on impaired self-awareness after TBI. This was a randomized, assessor-blinded trial with concealed allocation. A total of 54 participants with TBI and impaired self-awareness (85% male) were recruited from inpatient and community rehabilitation settings. Participants performed a meal preparation task on 4 occasions and were randomly assigned to 1 of 3 feedback intervention groups: video plus verbal feedback, verbal feedback, or experiential feedback. The primary outcome was improvement in online awareness measured by the number of errors made during task completion. Secondary outcomes included level of intellectual awareness, self-perception of rehabilitation, and emotional status. Receiving video plus verbal feedback reduced the number of errors more than verbal feedback alone (mean difference = 19.7 errors; 95% confidence interval [CI] = 9.2-30.1) and experiential feedback alone (mean difference = 12.4 errors; 95% CI = 1.8-23.0). The results suggest that the video plus verbal feedback approach used in this study was effective in improving self-awareness in people with TBI. The results also provide evidence that improvement in self-awareness was not accompanied by deterioration in emotional status.

  19. Functional MRI Assessment of Task-Induced Deactivation of the Default Mode Network in Alzheimer’s Disease and At-Risk Older Individuals

    Directory of Open Access Journals (Sweden)

    Maija Pihlajamäki

    2009-01-01

    Full Text Available Alzheimer’s disease (AD is the most common form of dementia in old age, and is characterized by prominent impairment of episodic memory. Recent functional imaging studies in AD have demonstrated alterations in a distributed network of brain regions supporting memory function, including regions of the default mode network. Previous positron emission tomography studies of older individuals at risk for AD have revealed hypometabolism of association cortical regions similar to the metabolic abnormalities seen in AD patients. In recent functional magnetic resonance imaging (fMRI studies of AD, corresponding brain default mode regions have also been found to demonstrate an abnormal fMRI task-induced deactivation response pattern. That is, the relative decreases in fMRI signal normally observed in the default mode regions in healthy subjects performing a cognitive task are not seen in AD patients, or may even be reversed to a paradoxical activation response. Our recent studies have revealed alterations in the pattern of deactivation also in elderly individuals at risk for AD by virtue of their APOE e4 genotype, or evidence of mild cognitive impairment (MCI. In agreement with recent reports from other groups, these studies demonstrate that the pattern of fMRI task-induced deactivation is progressively disrupted along the continuum from normal aging to MCI and to clinical AD and more impaired in e4 carriers compared to non-carriers. These findings will be discussed in the context of current literature regarding functional imaging of the default network in AD and at-risk populations.

  20. Task-dependent modulation of functional connectivity between hand motor cortices and neuronal networks underlying language and music: a transcranial magnetic stimulation study in humans.

    Science.gov (United States)

    Sparing, R; Meister, I G; Wienemann, M; Buelte, D; Staedtgen, M; Boroojerdi, B

    2007-01-01

    Although language functions are, in general, attributed to the left hemisphere, it is still a matter of debate to what extent the cognitive functions underlying the processing of music are lateralized in the human brain. To investigate hemispheric specialization we evaluated the effect of different overt musical and linguistic tasks on the excitability of both left and right hand motor cortices using transcranial magnetic stimulation (TMS). Task-dependent changes of the size of the TMS-elicited motor evoked potentials were recorded in 12 right-handed, musically naive subjects during and after overt speech, singing and humming, i.e. the production of melody without word articulation. The articulation of meaningless syllables served as control condition. We found reciprocal lateralized effects of overt speech and musical tasks on motor cortex excitability. During overt speech, the corticospinal projection of the left (i.e. dominant) hemisphere to the right hand was facilitated. In contrast, excitability of the right motor cortex increased during both overt singing and humming, whereas no effect was observed on the left hemisphere. Although the traditional concept of hemispheric lateralization of music has been challenged by recent neuroimaging studies, our findings demonstrate that right-hemisphere preponderance of music is nevertheless present. We discuss our results in terms of the recent concepts on evolution of language and gesture, which hypothesize that cerebral networks mediating hand movement and those subserving language processing are functionally linked. TMS may constitute a useful tool to further investigate the relationship between cortical representations of motor functions, music and language using comparative approaches.

  1. 语义、语法任务相关的脑功能磁共振成像%Functional MRI related with the semantic and syntactic task

    Institute of Scientific and Technical Information of China (English)

    冯燕韻; 黄飚; 高明勇; 刘泳坚; 梁长虹

    2012-01-01

    目的 设计适用于临床的脑语言fMRI任务刺激模式,并观察与汉语语言相关的脑功能区.方法 对22名健康志愿者在模拟临床语言生成模式下进行汉语语义、语法句子正确性判断,同时采集[MR]数据,通过后处理分析获得汉语语言相关的脑功能区,对其进行定位,并判断汉语的语言优势半球.结果 语义、语法判断任务激活的脑功能区有很大重叠,双侧额下回、双侧顶上小叶、双侧枕叶及左侧辅助运动区在两种语言任务中均有明显激活.汉语语言的脑激活区额下回表现为左侧半球优势.结论 应用语义、语法句子判断的语言刺激模式能激活正常人语言相关的脑功能区,简单易行,依从性好,激活脑功能区稳定,适用于临床对语言脑功能区进行定位.%To design a language simulated task for clinical application on fMRI, and to observe the functional language areas of the brain. Methods Totally 22 healthy volunteers participated in this study. Functional data were collected when performed the language tasks and analyzed by SPM8, then locating of the functional language areas and determining of the Chinese language hemisphere were done. Results Activated brain areas in semantic and syntax tasks respectively had a great overlap, bilateral inferior frontal areas, inferior parietal lobe, occipital lobe and the left supplementary motor areas were significantly activated. The left dominant hemisphere was found in inferior frontal gyrus as Chinese language functional brain areas. Conclusion Using the judgment of semantic or syntactic task could be implemented in clinical delecting of brain areas related to Chinese expression with functional MRI

  2. Detailed Debunking of Denial

    Science.gov (United States)

    Enting, I. G.; Abraham, J. P.

    2012-12-01

    The disinformation campaign against climate science has been compared to a guerilla war whose tactics undermine the traditional checks and balances of science. One comprehensive approach has to been produce archives of generic responses such as the websites of RealClimate and SkepticalScience. We review our experiences with an alternative approach of detailed responses to a small number of high profile cases. Our particular examples were Professor Ian Plimer and Christopher Monckton, the Third Viscount Monckton of Brenchley, each of whom has been taken seriously by political leaders in our respective countries. We relate our experiences to comparable examples such as John Mashey's analysis of the Wegman report and the formal complaints about Lomborg's "Skeptical Environmentalist" and Durkin's "Great Global Warming Swindle". Our two approaches used contrasting approaches: an on-line video of a lecture vs an evolving compendium of misrepresentations. Additionally our approaches differed in the emphasis. The analysis of Monckton concentrated on the misrepresentation of the science, while the analysis of Plimer concentrated on departures from accepted scientific practice: fabrication of data, misrepresentation of cited sources and unattributed use of the work of others. Benefits of an evolving compendium were the ability to incorporate contributions from members of the public who had identified additional errors and the scope for addressing new aspects as they came to public attention. `Detailed debunking' gives non-specialists a reference point for distinguishing non-science when engaging in public debate.

  3. Reduction of redundant neural network activation during the performance of a task: a functional model applied to problem-solving strategies.

    Science.gov (United States)

    Gupta, S K

    1999-01-01

    Problem-solving is explained by various paradigms. For example, epistemological paradigms state that, when the task is novel, and pursued of one's free will, problem-solving occurs in discontinuous, discernable phases. It is then also a microdevelopmental process, i.e. involves the construction of knowledge through qualitatively different stages of thought. Quantitative methods are used to focus on the redundancy of function as well as the concept of selective activation of the brains's neural network during the performance of a task. In this model, the following are identified: (a) performance circuits: (i) NP, no performance; (ii) LP, low performance; (iii) MP, medium performance; (iv) HP, high performance; and (v) VHR, very high performance; (b) task performance groups: (i) NOU, no outline used; (serves as a control); (ii) OU, outline used; (iii) MOU, modified outline used; (iv) QMOU, qualitatively and quantitatively modified outline used. An example of a distribution that one obtains is (for the efficiency of activation of the HP): QMOU:MOU:OU. NOU is in the ratio of: 400:100:50:5 (out of 10(3) trials). The subject is hence educated as to the mechanism of various strategies that he may use in everyday problem-solving.

  4. Load-dependent brain activation assessed by time-domain functional near-infrared spectroscopy during a working memory task with graded levels of difficulty

    Science.gov (United States)

    Molteni, Erika; Contini, Davide; Caffini, Matteo; Baselli, Giuseppe; Spinelli, Lorenzo; Cubeddu, Rinaldo; Cerutti, Sergio; Bianchi, Anna Maria; Torricelli, Alessandro

    2012-05-01

    We evaluated frontal brain activation during a mixed attentional/working memory task with graded levels of difficulty in a group of 19 healthy subjects, by means of time-domain functional near-infrared spectroscopy (fNIRS). Brain activation was assessed, and load-related oxy- and deoxy-hemoglobin changes were studied. Generalized linear model (GLM) was applied to the data to explore the metabolic processes occurring during the mental effort and, possibly, their involvement in short-term memorization. GLM was applied to the data twice: for modeling the task as a whole and for specifically investigating brain activation at each cognitive load. This twofold employment of GLM allowed (1) the extraction and isolation of different information from the same signals, obtained through the modeling of different cognitive categories (sustained attention and working memory), and (2) the evaluation of model fitness, by inspection and comparison of residuals (i.e., unmodeled part of the signal) obtained in the two different cases. Results attest to the presence of a persistent attentional-related metabolic activity, superimposed to a task-related mnemonic contribution. Some hemispherical differences have also been highlighted frontally: deoxy-hemoglobin changes manifested a strong right lateralization, whereas modifications in oxy- and total hemoglobin showed a medial localization. The present work successfully explored the capability of fNIRS to detect the two neurophysiological categories under investigation and distinguish their activation patterns.

  5. Modeling of Task Planning for Multirobot System Using Reputation Mechanism

    Directory of Open Access Journals (Sweden)

    Zhiguo Shi

    2014-01-01

    Full Text Available Modeling of task planning for multirobot system is developed from two parts: task decomposition and task allocation. In the part of task decomposition, the conditions and processes of decomposition are elaborated. In the part of task allocation, the collaboration strategy, the framework of reputation mechanism, and three types of reputations are defined in detail, which include robot individual reputation, robot group reputation, and robot direct reputation. A time calibration function and a group calibration function are designed to improve the effectiveness of the proposed method and proved that they have the characteristics of time attenuation, historical experience related, and newly joined robot reward. Tasks attempt to be assigned to the robot with higher overall reputation, which can help to increase the success rate of the mandate implementation, thereby reducing the time of task recovery and redistribution. Player/Stage is used as the simulation platform, and three biped-robots are established as the experimental apparatus. The experimental results of task planning are compared with the other allocation methods. Simulation and experiment results illustrate the effectiveness of the proposed method for multi-robot collaboration system.

  6. Global detailed gravimetric geoid

    Science.gov (United States)

    Vincent, S.; Marsh, J. G.

    1974-01-01

    A global detailed gravimetric geoid has been computed by combining the Goddard Space Flight Center GEM-4 gravity model derived from satellite and surface gravity data and surface 1 x 1-deg mean free-air gravity anomaly data. The accuracy of the geoid is plus or minus 2 meters on continents, 5 to 7 meters in areas where surface gravity data are sparse, and 10 to 15 meters in areas where no surface gravity data are available. Comparisons have been made with the astrogeodetic data provided by Rice (United States), Bomford (Europe), and Mather (Australia). Comparisons have also been carried out with geoid heights derived from satellite solutions for geocentric station coordinates in North America, the Caribbean, Europe and Australia.

  7. Consider the details

    DEFF Research Database (Denmark)

    Rasmussen, Rasmus; Hertzum, Morten

    2013-01-01

    levels of distance in our study. For revision time, the electronic whiteboard is slower on one subtask but there is no difference on another subtask. Participants prefer the electronic whiteboard. Given the font size of the electronic whiteboard, the inferior reading accuracy is unsurprising......Electronic whiteboards are replacing dry-erase whiteboards in many contexts. In this study we compare electronic and dry-erase whiteboards in emergency departments (EDs) with respect to reading distance and revision time. We find inferior reading accuracy for the electronic whiteboard at all three...... but the reduced possibilities for acquiring information at a glance when clinicians pass the whiteboard may adversely affect their overview. Conversely, the similar revision times for one subtask show that logon may be done quickly. We discuss how details such as font size and logon may impact the high-level...

  8. Effectiveness of dual-task functional power training for preventing falls in older people: study protocol for a cluster randomised controlled trial.

    Science.gov (United States)

    Daly, Robin M; Duckham, Rachel L; Tait, Jamie L; Rantalainen, Timo; Nowson, Caryl A; Taaffe, Dennis R; Sanders, Kerrie; Hill, Keith D; Kidgell, Dawson J; Busija, Lucy

    2015-03-27

    Falls are a major public health concern with at least one third of people aged 65 years and over falling at least once per year, and half of these will fall repeatedly, which can lead to injury, pain, loss of function and independence, reduced quality of life and even death. Although the causes of falls are varied and complex, the age-related loss in muscle power has emerged as a useful predictor of disability and falls in older people. In this population, the requirements to produce explosive and rapid movements often occurs whilst simultaneously performing other attention-demanding cognitive or motor tasks, such as walking while talking or carrying an object. The primary aim of this study is to determine whether dual-task functional power training (DT-FPT) can reduce the rate of falls in community-dwelling older people. The study design is an 18-month cluster randomised controlled trial in which 280 adults aged ≥65 years residing in retirement villages, who are at increased risk of falling, will be randomly allocated to: 1) an exercise programme involving DT-FPT, or 2) a usual care control group. The intervention is divided into 3 distinct phases: 6 months of supervised DT-FPT, a 6-month 'step down' maintenance programme, and a 6-month follow-up. The primary outcome will be the number of falls after 6, 12 and 18 months. Secondary outcomes will include: lower extremity muscle power and strength, grip strength, functional assessments of gait, reaction time and dynamic balance under single- and dual-task conditions, activities of daily living, quality of life, cognitive function and falls-related self-efficacy. We will also evaluate the cost-effectiveness of the programme for preventing falls. The study offers a novel approach that may guide the development and implementation of future community-based falls prevention programmes that specifically focus on optimising muscle power and dual-task performance to reduce falls risk under 'real life' conditions in older

  9. Effect of low-frequency repetitive transcranial magnetic stimulation combining task-oriented training on upper limb motor function recovery after stroke

    Directory of Open Access Journals (Sweden)

    Hong-bin WANG

    2017-07-01

    Full Text Available Objective To investigate the effect of low-frequency repetitive transcranial magnetic stimulation (rTMS combined with task-oriented training on the recovery of upper limb motor function of stroke patients. Methods A total of 42 patients with hemiplegia after stroke were randomly divided into control group (N = 20 and treatment group (N = 22. Control group received routine rehabilitation training and task-oriented training, and treatment group received low-frequency (1 Hz rTMS over the contralesional cortex addition to routine rehabilitation and task-oriented training. Fugl-Meyer Assessment Scale for Upper Extremity (FMA-UE and Wolf Motor Function Test (WMFT were used to evaluate upper limb motor function of all patients before treatment, after 4-week treatment and 3 months after treatment. The latency and central motor conduction time (CMCT of motor-evoked potential (MEP in the contralesional cortex were recorded and analyzed. Results Compared with control group, FMA-UE score (P = 0.006 and WMFT score (P = 0.024 were significantly increased in treatment group. There was significant difference in FMA-AUE score (P = 0.000 and WMFT score (P = 0.000 at different time points. Compared with before treatment, FMA-UE score (P = 0.000, for all and WMFT score (P = 0.000, for all of patients in both groups were all significantly increased after 4-week treatment and 3 months after treatment. Besides, FMA-UE score (P = 0.000, for all and WMFT score (P = 0.000, for all 3 months after treatment were higher than those after 4-week treatment. There was no statistically significant difference between 2 groups on the latency (P = 0.979 and CMCT (P = 0.807 of MEP before and after treatment, and so was the difference on the latency (P = 0.085 and CMCT (P = 0.507 of MEP in the contralesional cortex at different time points (before treatment, after 4-week treatment and 3 months after treatment. Conclusions Low-frequency rTMS over the contralesional cortex combined

  10. Cognitive function and gait speed under normal and dual-task walking among older adults with mild cognitive impairment

    National Research Council Canada - National Science Library

    Doi, Takehiko; Shimada, Hiroyuki; Makizako, Hyuma; Tsutsumimoto, Kota; Uemura, Kazuki; Anan, Yuya; Suzuki, Takao

    2014-01-01

    .... We classified 389 elderly adults into amnestic MCI (n = 191) and non-amnestic MCI (n = 198), assessed their cognitive functions, and administered gait experiments under NW and DTW conditions...

  11. 32 CFR 700.1053 - Commander of a task force.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Commander of a task force. 700.1053 Section 700... Command Detail to Duty § 700.1053 Commander of a task force. (a) A geographic fleet commander, and any other naval commander, may detail in command of a task force, or other task command, any...

  12. Crowdsourcing detailed flood data

    Science.gov (United States)

    Walliman, Nicholas; Ogden, Ray; Amouzad*, Shahrzhad

    2015-04-01

    Over the last decade the average annual loss across the European Union due to flooding has been 4.5bn Euros, but increasingly intense rainfall, as well as population growth, urbanisation and the rising costs of asset replacements, may see this rise to 23bn Euros a year by 2050. Equally disturbing are the profound social costs to individuals, families and communities which in addition to loss of lives include: loss of livelihoods, decreased purchasing and production power, relocation and migration, adverse psychosocial effects, and hindrance of economic growth and development. Flood prediction, management and defence strategies rely on the availability of accurate information and flood modelling. Whilst automated data gathering (by measurement and satellite) of the extent of flooding is already advanced it is least reliable in urban and physically complex geographies where often the need for precise estimation is most acute. Crowdsourced data of actual flood events is a potentially critical component of this allowing improved accuracy in situations and identifying the effects of local landscape and topography where the height of a simple kerb, or discontinuity in a boundary wall can have profound importance. Mobile 'App' based data acquisition using crowdsourcing in critical areas can combine camera records with GPS positional data and time, as well as descriptive data relating to the event. This will automatically produce a dataset, managed in ArcView GIS, with the potential for follow up calls to get more information through structured scripts for each strand. Through this local residents can provide highly detailed information that can be reflected in sophisticated flood protection models and be core to framing urban resilience strategies and optimising the effectiveness of investment. This paper will describe this pioneering approach that will develop flood event data in support of systems that will advance existing approaches such as developed in the in the UK

  13. Glutamine and Glutamate Complex, as Measured by Functional Magnetic Resonance Spectroscopy, Alters During Face-Name Association Task in Patients with Mild Cognitive Impairment and Alzheimer's Disease.

    Science.gov (United States)

    Jahng, Geon-Ho; Oh, Janghoon; Lee, Do-Wan; Kim, Hyug-Gi; Rhee, Hak Young; Shin, Wonchul; Paik, Jong-Woo; Lee, Kyung Mi; Park, Soonchan; Choe, Bo-Young; Ryu, Chang-Woo

    2016-03-05

    The metabolite response during a memory task in Alzheimer's disease (AD) patients is unknown. To investigate the metabolite changes in subjects with AD, amnestic mild cognitive impairment (aMCI), and cognitively normal (CN) elderly during a memory task using functional magnetic resonance spectroscopy (fMRS). This study involved 23 young normal controls (YC), 24 CN elderly, 24 aMCI, and 24 mild and probable AD individuals. fMRS data were acquired at the precuneus and posterior cingulate brain regions during a face-name association task. Statistical analyses of quantified metabolites were performed to evaluate differences of the metabolite values between the stimulation conditions and among the four subject groups. Receiver operating curve analysis was performed to evaluate whether the metabolic changes after functional activations can differentiate the subject groups. Glutamine and glutamate complex (Glx) was statistically significantly different between the fixation and repeat conditions in aMCI (p = 0.0492) as well as between the fixation and the novel conditions in the AD (p = 0.0412) group. The total N-acetylaspartate (tNAA) was statistically significantly different among the four subject groups in the fixation condition (DF = 3, F = 7.673, p <  0.001), the novel condition (DF = 3, F = 6.945, p <  0.001), and the repeat condition (DF = 3, F = 7.127, p <  0.001). tNAA, tCr, and mIns could be used to differentiate CN from aMCI. Furthermore, tNAA, tCr, Glx, and Glu could also differentiate CN from AD, and aMCI from AD. Glx was altered during a stimulation that may be used to evaluate neuronal dysfunction in a demented patient. tNAA and tCr were reduced in patients with AD.

  14. Detailed IR aperture measurements

    CERN Document Server

    Bruce, Roderik; Garcia Morales, Hector; Giovannozzi, Massimo; Hermes, Pascal Dominik; Mirarchi, Daniele; Quaranta, Elena; Redaelli, Stefano; Rossi, Carlo; Skowronski, Piotr Krzysztof; Wretborn, Sven Joel; CERN. Geneva. ATS Department

    2016-01-01

    MD 1673 was carried out on October 5 2016, in order to investigate in more detail the available aperture in the LHC high-luminosity insertions at 6.5 TeV and β∗=40 cm. Previous aperture measurements in 2016 during commissioning had shown that the available aperture is at the edge of protection, and that the aperture bottleneck at β∗=40 cm in certain cases is found in the separation plane instead of in the crossing plane. Furthermore, the bottlenecks were consistently found in close to the upstream end of Q3 on the side of the incoming beam, and not in Q2 on the outgoing beam as expected from calculations. Therefore, this MD aimed at measuring IR1 and IR5 separately (at 6.5 TeV and β∗=40 cm, for 185 µrad half crossing angle), to further localize the bottlenecks longitudinally using newly installed BLMs, investigate the difference in aperture between Q2 and Q3, and to see if any aperture can be gained using special orbit bumps.

  15. Space station data system analysis/architecture study. Task 1: Functional requirements definition, DR-5. Appendix: Requirements data base

    Science.gov (United States)

    1985-01-01

    Appendix A contains data that characterize the system functions in sufficient depth as to determine the requirements for the Space Station Data System (SSDS). This data is in the form of: (1) top down traceability report; (2) bottom up traceability report; (3) requirements data sheets; and (4) cross index of requirements paragraphs of the source documents and the requirements numbers. A data base users guide is included that interested parties can use to access the requirements data base and get up to date information about the functions.

  16. Functional roles of 10 Hz alpha-band power modulating engagement and disengagement of cortical networks in a complex visual motion task.

    Directory of Open Access Journals (Sweden)

    Kunjan D Rana

    Full Text Available Alpha band power, particularly at the 10 Hz frequency, is significantly involved in sensory inhibition, attention modulation, and working memory. However, the interactions between cortical areas and their relationship to the different functional roles of the alpha band oscillations are still poorly understood. Here we examined alpha band power and the cortico-cortical interregional phase synchrony in a psychophysical task involving the detection of an object moving in depth by an observer in forward self-motion. Wavelet filtering at the 10 Hz frequency revealed differences in the profile of cortical activation in the visual processing regions (occipital and parietal lobes and in the frontoparietal regions. The alpha rhythm driving the visual processing areas was found to be asynchronous with the frontoparietal regions. These findings suggest a decoupling of the 10 Hz frequency into separate functional roles: sensory inhibition in the visual processing regions and spatial attention in the frontoparietal regions.

  17. Functional roles of 10 Hz alpha-band power modulating engagement and disengagement of cortical networks in a complex visual motion task.

    Science.gov (United States)

    Rana, Kunjan D; Vaina, Lucia M

    2014-01-01

    Alpha band power, particularly at the 10 Hz frequency, is significantly involved in sensory inhibition, attention modulation, and working memory. However, the interactions between cortical areas and their relationship to the different functional roles of the alpha band oscillations are still poorly understood. Here we examined alpha band power and the cortico-cortical interregional phase synchrony in a psychophysical task involving the detection of an object moving in depth by an observer in forward self-motion. Wavelet filtering at the 10 Hz frequency revealed differences in the profile of cortical activation in the visual processing regions (occipital and parietal lobes) and in the frontoparietal regions. The alpha rhythm driving the visual processing areas was found to be asynchronous with the frontoparietal regions. These findings suggest a decoupling of the 10 Hz frequency into separate functional roles: sensory inhibition in the visual processing regions and spatial attention in the frontoparietal regions.

  18. Patients Undergoing Subacute Physical Rehabilitation following an Acute Hospital Admission Demonstrated Improvement in Cognitive Functional Task Independence

    Directory of Open Access Journals (Sweden)

    Steven M. McPhail

    2014-01-01

    Full Text Available Objective. This study investigated cognitive functioning among older adults with physical debility not attributable to an acute injury or neurological condition who were receiving subacute inpatient physical rehabilitation. Design. A cohort investigation with assessments at admission and discharge. Setting. Three geriatric rehabilitation hospital wards. Participants. Consecutive rehabilitation admissions (n=814 following acute hospitalization (study criteria excluded orthopaedic, neurological, or amputation admissions. Intervention. Usual rehabilitation care. Measurements. The Functional Independence Measure (FIM Cognitive and Motor items. Results. A total of 704 (86.5% participants (mean age = 76.5 years completed both assessments. Significant improvement in FIM Cognitive items (Z-score range 3.93–8.74, all P<0.001 and FIM Cognitive total score (Z-score = 9.12, P<0.001 occurred, in addition to improvement in FIM Motor performance. A moderate positive correlation existed between change in Motor and Cognitive scores (Spearman’s rho = 0.41. Generalized linear modelling indicated that better cognition at admission (coefficient = 0.398, P<0.001 and younger age (coefficient = −0.280, P<0.001 were predictive of improvement in Motor performance. Younger age (coefficient = −0.049, P<0.001 was predictive of improvement in FIM Cognitive score. Conclusions. Improvement in cognitive functioning was observed in addition to motor function improvement among this population. Causal links cannot be drawn without further research.

  19. Improvements in hand function in adults with chronic tetraplegia following a multi-day 10Hz rTMS intervention combined with repetitive task practice

    Science.gov (United States)

    Gomes-Osman, Joyce; Field-Fote, Edelle C.

    2014-01-01

    Background and Purpose Evidence suggests the use of stimulation to increase corticomotor excitability improves hand function in persons with cervical spinal cord injury (SCI). We assessed effects of multi-day application of 10Hz repetitive transcranial magnetic stimulation (rTMS) applied to the corticomotor hand area combined with repetitive task practice (RTP) in participants with tetraplegia and neurologically healthy participants. Methods Using a double-blind randomized crossover design, 11 participants with chronic tetraplegia and 10 neurologically healthy participants received 3 sessions of 10Hz rTMS+RTP and 3 sessions of sham-rTMS+RTP to the corticomotor hand region controlling the weaker hand. RTMS was interleaved with RTP of a skilled motor task between pulse trains. Hand function (Jebsen-Taylor Hand Function Test [JTT], pinch, and grasp strength) and corticomotor excitability (amplitude of motor-evoked potential) were assessed prior to and following the rTMS+RTP and sham-rTMS+RTP phases. We assessed significance using paired t-tests on pre-post differences and effect sizes using standardized response mean (SRM). Results RTMS+RTP was associated with larger effect sizes compared to sham-rTMS+RTP for improvement in JTT for both the trained hand (SRM=0.85 and 0.42, respectively), non-trained hand (0.55, 0.31, respectively), and for grasp strength of the trained hand in the SCI group (0.67, 0.39, respectively) alone. Effect sizes for all other measures were small and there were no statistical between-condition differences in the outcomes assessed. Discussion and Conclusions RTMS may be a valuable adjunct to RTP for improving hand function in persons with tetraplegia. Higher stimulation dose (frequency, intensity, number of sessions) may be associated with larger effects. Video Abstract available (See Supplemental Digital Conent 1) for more insights from the authors. PMID:25415549

  20. Cortical vs. afferent stimulation as an adjunct to functional task practice training: a randomized, comparative pilot study in people with cervical spinal cord injury.

    Science.gov (United States)

    Gomes-Osman, Joyce; Field-Fote, Edelle C

    2015-08-01

    To assess single-session effects of three different types of stimuli known to increase cortical excitability when combined with functional task practice. Randomized cross-over trial. A total of 24 participants with chronic cervical spinal cord injury. One 30-minute session of each, applied concurrently with functional task practice: transcranial direct current stimulation, vibration, and transcutaneous electrical nerve stimulation. Nine-hole Peg Test, pinch force, visuomotor tracking, and cortical excitability were collected at pretest, posttest and late posttest (30 minutes after). Early effects (posttest minus pretest) and short-term persistence (late posttest minus pretest) were assessed using a general linear mixed model. Magnitude of effect size was assessed using the Cohen's d. Transcutaneous electrical nerve stimulation was associated with moderate, significant early effects and short-term persistence on Nine-hole Peg Test performance (1.8 ±1.8, p = 0.003, d = 0.59; 2.0 ±2.5, p stimulation (1.8 ±2.5, p = 0.003, Cohen's d = 0.52) was also associated with significant short-term persistence of moderate size on Nine-hole Peg Test performance (1.8 ±2.5, p = 0.003, Cohen's d = 0.52) and visuomotor tracking performance (p = 0.05, d = 0.51). Early effects on corticomotor excitability were significant for transcutaneous electrical nerve stimulation (p = 0.003), approached significance for transcranial direct current stimulation (p = 0.07), and only vibration was associated with significant short-term persistence (p = 0.006). Meaningful improvements in aspects of hand-related function that persisted at least 30 minutes after intervention were observed with transcutaneous electrical nerve stimulation and transcranial direct current stimulation, when combined with functional task practice. © The Author(s) 2014.

  1. THE LIFE-MODELING FUNCTION OF TASKS IN RUSSIAN SCHOOL TEXTBOOKS OF THE 1920S AND 1930S

    Directory of Open Access Journals (Sweden)

    Kuljapin, A.I.

    2016-03-01

    Full Text Available In modern social science, the notion of the “a hidden curriculum” refers to a set of beliefs imposed on pupils in an indirect way. The authors of Soviet school textbooks never tried to hide their ideological components, even during the relatively liberal 1920s. On the contrary, ideology was deliberately and overtly demonstrated in them. Mathematics is generally considered to be a science as far from politics as is possible, but even this was used by the school of the Stalin era in the service of propagandist educational aims. The transformation of schools from fairly liberal to fully totalitarian institutions took just a few years, and the basic principles of Soviet pedagogical science transformed rapidly during the 1920s and the 1930s. In the original manuals on Mathematics, the change is especially obvious. A kind of a model of Social Realism is dominant in the textbooks of this period, where it is important to note that this happened before it became the main method at use in the Soviet literature more broadly. The Soviet routine at the beginning of the 1920s is depicted in such books with realistic detail. Among the topics that dominate are hunger, disease, poverty, as well as natural and social disasters. A specific Soviet model of the world is formulated in arithmetical textbooks. When looking at current pedagogies, edification receives certain emphasis, and in the case of school arithmetic, refers more infrequently to aspects of daily life. A conflict between the real and the ideal is settled in favour of the latter. In this way Mathematics is considered to be one of the factors of Communist education.

  2. Memory for details with self-referencing.

    Science.gov (United States)

    Serbun, Sarah J; Shih, Joanne Y; Gutchess, Angela H

    2011-11-01

    Self-referencing benefits item memory, but little is known about the ways in which referencing the self affects memory for details. Experiment 1 assessed whether the effects of self-referencing operate only at the item, or general, level or whether they also enhance memory for specific visual details of objects. Participants incidentally encoded objects by making judgements in reference to the self, a close other (one's mother), or a familiar other (Bill Clinton). Results indicate that referencing the self or a close other enhances both specific and general memory. Experiments 2 and 3 assessed verbal memory for source in a task that relied on distinguishing between different mental operations (internal sources). The results indicate that self-referencing disproportionately enhances source memory, relative to conditions referencing other people, semantic, or perceptual information. We conclude that self-referencing not only enhances specific memory for both visual and verbal information, but can also disproportionately improve memory for specific internal source details.

  3. Organizing Core Tasks

    DEFF Research Database (Denmark)

    Boll, Karen

    Civil servants conduct the work which makes welfare states functions on an everyday bases: Police men police, school teachers teach, and tax inspectors inspect. Focus in this paper is on the core tasks of tax inspectors. The paper argues that their core task of securing the collection of revenue...... has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...

  4. Sex Differences in Gamma Band Functional Connectivity Between the Frontal Lobe and Cortical Areas During an Auditory Oddball Task, as Revealed by Imaginary Coherence Assessment

    Science.gov (United States)

    Fujimoto, Toshiro; Okumura, Eiichi; Kodabashi, Atsushi; Takeuchi, Kouzou; Otsubo, Toshiaki; Nakamura, Katsumi; Yatsushiro, Kazutaka; Sekine, Masaki; Kamiya, Shinichiro; Shimooki, Susumu; Tamura, Toshiyo

    2016-01-01

    We studied sex-related differences in gamma oscillation during an auditory oddball task, using magnetoencephalography and electroencephalography assessment of imaginary coherence (IC). We obtained a statistical source map of event-related desynchronization (ERD) / event-related synchronization (ERS), and compared females and males regarding ERD / ERS. Based on the results, we chose respectively seed regions for IC determinations in low (30-50 Hz), mid (50-100 Hz) and high gamma (100-150 Hz) bands. In males, ERD was increased in the left posterior cingulate cortex (CGp) at 500 ms in the low gamma band, and in the right caudal anterior cingulate cortex (cACC) at 125 ms in the mid-gamma band. ERS was increased in the left rostral anterior cingulate cortex (rACC) at 375 ms in the high gamma band. We chose the CGp, cACC and rACC as seeds, and examined IC between the seed and certain target regions using the IC map. IC changes depended on the height of the gamma frequency and the time window in the gamma band. Although IC in the mid and high gamma bands did not show sex-specific differences, IC at 30-50 Hz in males was increased between the left rACC and the frontal, orbitofrontal, inferior temporal and fusiform target regions. Increased IC in males suggested that males may acomplish the task constructively, analysingly, emotionally, and by perfoming analysis, and that information processing was more complicated in the cortico-cortical circuit. On the other hand, females showed few differences in IC. Females planned the task with general attention and economical well-balanced processing, which was explained by the higher overall functional cortical connectivity. CGp, cACC and rACC were involved in sex differences in information processing and were likely related to differences in neuroanatomy, hormones and neurotransmitter systems. PMID:27708745

  5. Context-Dependent Modulation of Functional Connectivity: Secondary Somatosensory Cortex to Prefrontal Cortex Connections in Two-Stimulus-Interval Discrimination Tasks

    Science.gov (United States)

    Chow, Stephanie S.; Romo, Ranulfo; Brody, Carlos D.

    2010-01-01

    In a complex world, a sensory cue may prompt different actions in different contexts. A laboratory example of context-dependent sensory processing is the two-stimulus-interval discrimination task. In each trial, a first stimulus (f1) must be stored in short-term memory and later compared with a second stimulus (f2), for the animal to come to a binary decision. Prefrontal cortex (PFC) neurons need to interpret the f1 information in one way (perhaps with a positive weight) and the f2 information in an opposite way (perhaps with a negative weight), although they come from the very same secondary somatosensory cortex (S2) neurons; therefore, a functional sign inversion is required. This task thus provides a clear example of context-dependent processing. Here we develop a biologically plausible model of a context-dependent signal transformation of the stimulus encoding from S2 to PFC. To ground our model in experimental neurophysiology, we use neurophysiological data recorded by R. Romo’s laboratory from both cortical area S2 and PFC in monkeys performing the task. Our main goal is to use experimentally observed context-dependent modulations of firing rates in cortical area S2 as the basis for a model that achieves a context-dependent inversion of the sign of S2 to PFC connections. This is done without requiring any changes in connectivity (Salinas, 2004b). We (1) characterize the experimentally observed context-dependent firing rate modulation in area S2, (2) construct a model that results in the sign transformation, and (3) characterize the robustness and consequent biological plausibility of the model. PMID:19494146

  6. Research of cerebral activation in Uygur-speaking and Chinese-speaking participants during verb generation task with functional magnetic resonance imaging.

    Science.gov (United States)

    Xi, Yanling; Liu, Ling; Hao, Grace; Abudusadike, Zulipinuer; Jiang, Chunhui; Zhang, Junran; Wang, Baolan

    2017-07-01

    The aims are to investigate and compare the activated cerebral regions of Uygur-speaking and Chinese-speaking participants during verb generation task.A total of 31 cases of Uygur and 28 cases of Han healthy volunteers were enrolled. They were requested to take verb generation tasks. Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) was performed. The fMRI images were collected and activated brain regions were analyzed.In Chinese-speaking participants, the main activated cerebral regions were as follows: the left caudate nucleus, the left occipital gyrus, the left fusiform gyrus, bilateral supplementary motor area (BA8/ 6), the left BA32, left precuneus, the left superior parietal lobule, the left inferior parietal lobule (BA7), the left angular gyrus, the right side of the central gyrus (BA9), the left inferior frontal gyrus triangular section, the right pars opercularis gyri frontalis inferiorista, and bilateral cerebellum. In Uygur-speaking subjects, the main activated cerebral regions included left precentral gyrus (BA9 region), inferior frontal gyrus of left opercular part, inferior frontal gyrus of left triangle part, and left cerebellum. Left caudate nucleus, left orbital frontal gyrus, right caudate nucleus, and bilateral anterior cingulate gyrus (BA32 region) of Chinese group were significantly activated compared with Uygur group. By contrast, Uygur group showed no region that was more activated than Chinese group.The present study demonstrates that activated brain regions in verb generation tasks are different between Uygur and Chinese languages. Processing of Uygur characters is mainly in the left hemisphere of the brain, while the processing of Chinese characters needs more participation by the right hemisphere of the brain.

  7. An Exploratory Investigation of Functional Network Connectivity of Empathy and Default Mode Networks in a Free-Viewing Task.

    Science.gov (United States)

    Vemuri, Kavita; Surampudi, Bapi Raju

    2015-08-01

    This study reports dynamic functional network connectivity (dFNC) analysis on time courses of putative empathy networks-cognitive, emotional, and motor-and the default mode network (DMN) identified from independent components (ICs) derived by the group independent component analysis (ICA) method. The functional magnetic resonance imaging (fMRI) data were collected from 15 subjects watching movies of three genres, an animation (S1), Indian Hindi (S2), and a Hollywood English (S3) movie. The hypothesis of the study is that empathic engagement in a movie narrative would modulate the activation with the DMN. The clippings were individually rated for emotional expressions, context, and empathy self-response by the fMRI subjects post scanning and by 40 participants in an independent survey who rated at four time intervals in each clipping. The analysis illustrates the following: (a) the ICA method separated ICs with areas reported for empathy response and anterior/posterior DMNs. An IC indicating insula region activation reported to be crucial for the emotional empathy network was separated for S2 and S3 movies only, but not for S1, (b) the dFNC between DMN and ICs corresponding to cognitive empathy network showed higher positive periodical fluctuating correlations for all three movies, while ICs with areas crucial to motor or emotional empathy display lower positive or negative correlation values with no distinct periodicity. A possible explanation for the lower values and anticorrelation between the DMN and emotional empathy networks could possibly be inhibition due to internal self-reflections, attributed to DMN, while processing and preparing a response to external emotional content. The positive higher correlation values for cognitive empathy networks may reflect a functional overlap with DMN for enhanced internal self-reflections, inferring beliefs and intentions about the 'other', all triggered by the external stimuli. The findings are useful in the study of

  8. Meta-analysis of functional magnetic resonance imaging studies of inhibition and attention in attention-deficit/hyperactivity disorder: exploring task-specific, stimulant medication, and age effects.

    Science.gov (United States)

    Hart, Heledd; Radua, Joaquim; Nakao, Tomohiro; Mataix-Cols, David; Rubia, Katya

    2013-02-01

    CONTEXT Functional magnetic resonance imaging studies in attention-deficit/hyperactivity disorder (ADHD) revealed fronto-striato-parietal dysfunctions during tasks of inhibition and attention. However, it is unclear whether task-dissociated dysfunctions exist and to what extent they may be influenced by age and by long-term stimulant medication use. OBJECTIVE To conduct a meta-analysis of functional magnetic resonance imaging studies in ADHD during inhibition and attention tasks, exploring age and long-term stimulant medication use effects. DATA SOURCES PubMed, ScienceDirect, Web of Knowledge, Google Scholar, and Scopus databases were searched up to May 2012 for meta-analyses. Meta-regression methods explored age and long-term stimulant medication use effects. STUDY SELECTION Twenty-one data sets were included for inhibition (287 patients with ADHD and 320 control subjects), and 13 data sets were included for attention (171 patients with ADHD and 178 control subjects). DATA EXTRACTION Peak coordinates of clusters of significant group differences, as well as demographic, clinical, and methodological variables, were extracted for each study or were obtained from the authors. DATA SYNTHESIS Patients with ADHD relative to controls showed reduced activation for inhibition in the right inferior frontal cortex, supplementary motor area, and anterior cingulate cortex, as well as striato-thalamic areas, and showed reduced activation for attention in the right dorsolateral prefrontal cortex, posterior basal ganglia, and thalamic and parietal regions. Furthermore, the meta-regression analysis for the attention domain showed that long-term stimulant medication use was associated with more similar right caudate activation relative to controls. Age effects could be analyzed only for the inhibition meta-analysis, showing that the supplementary motor area and basal ganglia were underactivated solely in children with ADHD relative to controls, while the inferior frontal cortex and

  9. Theory of mind and executive function: working-memory capacity and inhibitory control as predictors of false-belief task performance.

    Science.gov (United States)

    Mutter, Brigitte; Alcorn, Mark B; Welsh, Marilyn

    2006-06-01

    This study of the relationship between theory of mind and executive function examined whether on the false-belief task age differences between 3 and 5 ears of age are related to development of working-memory capacity and inhibitory processes. 72 children completed tasks measuring false belief, working memory, and inhibition. Significant age effects were observed for false-belief and working-memory performance, as well as for the false-alarm and perseveration measures of inhibition. A simultaneous multiple linear regression specified the contribution of age, inhibition, and working memory to the prediction of false-belief performance. This model was significant, explaining a total of 36% of the variance. To examine the independent contributions of the working-memory and inhibition variables, after controlling for age, two hierarchical multiple linear regressions were conducted. These multiple regression analyses indicate that working memory and inhibition make small, overlapping contributions to false-belief performance after accounting for age, but that working memory, as measured in this study, is a somewhat better predictor of false-belief understanding than is inhibition.

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

    Science.gov (United States)

    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. Functional disconnection of the substantia nigra pars compacta from the pedunculopontine nucleus impairs learning of a conditioned avoidance task.

    Science.gov (United States)

    Bortolanza, Mariza; Wietzikoski, Evellyn C; Boschen, Suelen L; Dombrowski, Patricia A; Latimer, Mary; Maclaren, Duncan A A; Winn, Philip; Da Cunha, Claudio

    2010-09-01

    The pedunculopontine tegmental nucleus (PPTg) targets nuclei in the basal ganglia, including the substantia nigra pars compacta (SNc), in which neuronal loss occurs in Parkinson's disease, a condition in which patients show cognitive as well as motor disturbances. Partial loss and functional abnormalities of neurons in the PPTg are also associated with Parkinson's disease. We hypothesized that the interaction of PPTg and SNc might be important for cognitive impairments and so investigated whether disrupting the connections between the PPTg and SNc impaired learning of a conditioned avoidance response (CAR) by male Wistar rats. The following groups were tested: PPTg unilateral; SNc unilateral; PPTg-SNc ipsilateral (ipsilateral lesions in PPTg and SNc); PPTg-SNc contralateral (contralateral lesions in PPTg and SNc); sham lesions (of each type). SNc lesions were made with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine HCl (MPTP, 0.6micromol); PPTg lesions with ibotenate (24nmol). After recovery, all rats underwent 50-trial sessions of 2-way active avoidance conditioning for 3 consecutive days. Rats with unilateral lesions in PPTg or SNc learnt this, however rats with contralateral (but not ipsilateral) combined lesions in both structures presented no sign of learning. This effect was not likely to be due to sensorimotor impairment because lesions did not affect reaction time to the tone or footshock during conditioning. However, an increased number of non-responses were observed in the rats with contralateral lesions. The results support the hypothesis that a functional interaction between PPTg and SNc is needed for CAR learning and performance.

  12. Fun While Showing, Not Telling: Crafting Vivid Detail in Writing

    Science.gov (United States)

    Del Nero, Jennifer Renner

    2017-01-01

    This teaching tip highlights three writing minilessons that help students construct vivid sensory detail (textual detail related to the five senses) in their fiction and creative nonfiction writing. Learning to show, not tell, is a difficult task for novice writers. The author explores reasons why this is the case and provides directions for the…

  13. Peripheral inflammation related to lower fMRI activation during a working memory task and resting functional connectivity among older adults: a preliminary study.

    Science.gov (United States)

    Dev, Sheena I; Moore, Raeanne C; Soontornniyomkij, Benchawanna; Achim, Cristian L; Jeste, Dilip V; Eyler, Lisa T

    2017-03-01

    Peripheral inflammation has been associated with adverse effects on cognition and brain structure in late life, a process called 'inflammaging.' Identifying biomarkers of preclinical cognitive decline is critical in the development of preventative therapies, and peripheral inflammation may be able to serve as an indicator of cognitive decline. However, little is known regarding the relationship between peripheral inflammation and brain structure and function among older adults. Twenty-four older adults (mean age = 78) underwent a functional magnetic resonance imaging (fMRI) resting state functional connectivity scan, and a subset (n = 14) completed the n-Back working memory task in the scanner. All participants completed a blood draw, and inflammation was measured with interleukin 6 (IL-6) and C-Reactive Protein (CRP). Surprisingly, age was unrelated to measures of inflammation (IL-6, CRP) or brain function (default mode network (DMN) connectivity; working memory performance; blood oxygenation level dependent (BOLD) activation with higher working memory load). However, lower functional connectivity between the left parietal seed and all other DMN regions was associated with higher levels of IL-6 and CRP. Additionally, greater plasma concentration of IL-6 was associated with lower BOLD activation in the left middle frontal gyrus in response to increased working memory load. These preliminary findings support the importance of IL-6 and CRP in brain function among older adults. Frontal and parietal regions may be particularly sensitive to the effects of inflammation. Additionally, these findings provide preliminary evidence of inflammatory contributions to level of neural activity, even after accounting for vascular risk factors. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Application of the ex-Gaussian function to the effect of the word blindness suggestion on Stroop task performance suggests no word blindness

    Directory of Open Access Journals (Sweden)

    Benjamin Andrew Parris

    2013-09-01

    Full Text Available The aim of the present paper was to apply the ex-Gaussian function to data reported by Parris et al. (2012 given its utility in studies involving the Stroop task. Parris et al. showed an effect of the word blindness suggestion when Response-Stimulus Interval (RSI was 500ms but not when it was 3500ms. Analysis revealed that: 1 The effect of the suggestion on interference is observed in µ, supporting converging evidence indicating the suggestion operates over response competition mechanisms; and, 2 Contrary to Parris et al., an effect of the suggestion was observed in µ when RSI was 3500ms. The reanalysis of the data from Parris et al. (2012 supports the utility of ex-Gaussian analysis in revealing effects that might otherwise be thought of as absent. We suggest that word reading itself is not suppressed by the suggestion but instead that response conflict is dealt with more effectively.

  15. Frontopolar and anterior temporal cortex activation in a moral judgment task. Preliminary functional MRI results in normal subjects

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Jorge [LABS and Rede D' Or Hospitais, Rio de Janeiro RJ (Brazil). Grupo de Neuroimagem e Neurologia do Comportamento; Eslinger, Paul J. [Pensylvania State Univ. (United States). College of Medicine. Div. of Neurology and Behavioral Science; The Milton S. Hershey Medical Center, Hershey, PN (United States); Oliveira-Souza, Ricardo de [Universidade do Rio de Janeiro (UNI-Rio), RJ (Brazil). Hospital Universitario Gaffree e Guinle]. E-mail: neuropsychiatry@hotmail.com

    2001-09-01

    The objective was to study the brain areas which are activated when normal subjects make moral judgments. Ten normal adults underwent BOLD functional magnetic resonance imaging (fMRI) during the auditory presentation of sentences that they were instructed to silently judge as either 'right' or 'wrong'. Half of the sentences had an explicit moral content ('We break the law when necessary'), the other half comprised factual statements devoid of moral connotation ('Stones are made of water'). After scanning, each subject rated the moral content, emotional valence, and judgment difficulty of each sentence on Likert-like scales. To exclude the effect of emotion on the activation results, individual responses were hemo dynamically modeled for event-related f MRI analysis. The general linear model was used to evaluate the brain areas activated by moral judgment. Regions activated during moral judgment included the frontopolar cortex (FPC), medial frontal gyrus, right anterior temporal cortex, lenticular nucleus, and cerebellum. Activation of FPC and medial frontal gyrus (B A 10/46 and 9) were largely independent of emotional experience and represented the largest areas of activation. These results concur with clinical observations assigning a critical role for the frontal poles and right anterior temporal cortex in the mediation of complex judgment processes according to moral constraints. The FPC may work in concert with the orbitofrontal and dorsolateral cortex in the regulation of human social conduct. (author)

  16. Determination of hemispheric language dominance using functional magnetic resonance imaging and the Shiritori (Japanese word chain) task in patients with epilepsy: Comparison with the Wada test.

    Science.gov (United States)

    Kashida, Yumi; Otsubo, Toshiaki; Hanaya, Ryosuke; Kodabashi, Atsushi; Tsumagari, Noriko; Sugata, Sei; Hosoyama, Hiroshi; Iida, Koji; Nakamura, Katsumi; Tokimura, Hiroshi; Fujimoto, Toshiro; Arita, Kazunori

    2016-08-01

    The Wada test has been the gold standard for determining hemispheric language dominance (HLD) in the presurgical evaluation of patients scheduled for neurosurgical procedures. As it poses inherent risks associated with intra-arterial catheter techniques and as it occasionally fails to indicate language dominance, an alternative reliable test is needed. We quantitatively assessed the results of functional magnetic resonance imaging (fMRI) using the Shiritori task, a Japanese word chain, to identify the threshold for correctly predicting HLD. The subjects were 28 patients with intractable epilepsy scheduled to undergo the Wada test and focus resection. We set the region of interest (ROI) on the bilateral Brodmann areas 44 and 45 (BA 44 and 45). To compare the functional activity at both ROIs we calculated the language laterality index (LI) using the formula: [VL-VR]/[VL+VR]×100, where VL and VR indicated the number of activated voxels in the left and right ROIs, respectively. As 2 patients were excluded due to the lack of activation in either ROI, the final study population consisted of 26 patients. By the Wada test, HLD was left in 20, right in 3, and equivocal in 3. At a cut-off of LI+50, the predictive sensitivity and specificity for left HLD were 85% (17/20) and 100%; right HLD was predicted in a single patient (sensitivity 33.3%, specificity 100%). The fMRI using the Shiritori task showed good activation in ROI of BA 44 and 45. At a cut-off of LI+50, LI of BA 44 and 45 predicted HLD identified by the Wada test with high specificity. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. A novel semi-immersive virtual reality visuo-motor task activates ventrolateral prefrontal cortex: a functional near-infrared spectroscopy study

    Science.gov (United States)

    Basso Moro, Sara; Carrieri, Marika; Avola, Danilo; Brigadoi, Sabrina; Lancia, Stefania; Petracca, Andrea; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

    2016-06-01

    Objective. In the last few years, the interest in applying virtual reality systems for neurorehabilitation is increasing. Their compatibility with neuroimaging techniques, such as functional near-infrared spectroscopy (fNIRS), allows for the investigation of brain reorganization with multimodal stimulation and real-time control of the changes occurring in brain activity. The present study was aimed at testing a novel semi-immersive visuo-motor task (VMT), which has the features of being adopted in the field of neurorehabilitation of the upper limb motor function. Approach. A virtual environment was simulated through a three-dimensional hand-sensing device (the LEAP Motion Controller), and the concomitant VMT-related prefrontal cortex (PFC) response was monitored non-invasively by fNIRS. Upon the VMT, performed at three different levels of difficulty, it was hypothesized that the PFC would be activated with an expected greater level of activation in the ventrolateral PFC (VLPFC), given its involvement in the motor action planning and in the allocation of the attentional resources to generate goals from current contexts. Twenty-one subjects were asked to move their right hand/forearm with the purpose of guiding a virtual sphere over a virtual path. A twenty-channel fNIRS system was employed for measuring changes in PFC oxygenated-deoxygenated hemoglobin (O2Hb/HHb, respectively). Main results. A VLPFC O2Hb increase and a concomitant HHb decrease were observed during the VMT performance, without any difference in relation to the task difficulty. Significance. The present study has revealed a particular involvement of the VLPFC in the execution of the novel proposed semi-immersive VMT adoptable in the neurorehabilitation field.

  18. Exploring the Incorporation of Executive Functions in Intelligence Testing: Factor Analysis of the WAIS-III and Traditional Tasks of Executive Functioning

    NARCIS (Netherlands)

    Aken, L. van; Kessels, R.P.C.; Wingbermühle, P.A.M.; Wiltink, M.; Heijden, P.T. van der; Egger, J.I.M.

    2014-01-01

    The aim of this study was to examine the relationship between subtests of the Wechsler Adult Intelligence Scale – third edition (WAIS-III) and executive functions. The Behavioural Assessment of the Dysexecutive Syndrome, Wisconsin Card Sorting Test, and Stroop Color-Word Test were administered to a

  19. A COMPARATIVE STUDY TO ANALYZE THE EFFECT OF IMPAIRMENT BASED EXERCISE AND RESISTED EXERCISE ON PAIN, FUNCTIONAL TASKS IN INDIVIDUAL WITH KNEE OSTEOARTHRITIS

    Directory of Open Access Journals (Sweden)

    Camy A. Bhagat

    2015-08-01

    Full Text Available Background: Osteoarthritis also known as degenerative joint disease it is a most common form of arthritis and a leading cause of disabilities word wide. Osteoarthritis results from cartilage destruction, progression deterioration of osteoarthritis causes the normally smooth, white, translucent articular cartilage to become dull, yellow, and granular. That exercise provision for patients with knee OA reduces the pain experienced and the functional incapacity suffered by a small to moderate degree. Objective: To compare the effectiveness of Impairment based exercises and resisted exercise on pain, functional task in individual with knee OA. Methods: 30 patients with knee osteoarthritis were randomized into three groups: group A (Impairment based exercise(no of patients 10, group B (Resisted exercises(no of patients 10, group c (control group (no of patients 10 for 6 weeks exercise program. The outcome measures were VAS, WOMAC, LEFS. Result: The experimental group A showed significant more improvement in VAS, LEFS and WOMAC compared with group B and C after intervention. Conclusion: Impairment based exercises found to be more effective in improvement of function and reduction of pain in patients with knee OA.

  20. Functional connectivity between Layer 2/3 and Layer 5 neurons in prefrontal cortex of nonhuman primates during a delayed match-to-sample task.

    Science.gov (United States)

    Song, Dong; Opris, Ioan; Chan, Rosa H M; Marmarelis, Vasilis Z; Hampson, Robert E; Deadwyler, Sam A; Berger, Theodore W

    2012-01-01

    The prefrontal cortex (PFC) has been postulated to play critical roles in cognitive control and the formation of long-term memories. To gain insights into the neurobiological mechanism of such high-order cognitive functions, it is important to understand the input-output transformational properties of the PFC micro-circuitry. In this study, we identify the functional connectivity between the Layer 2/3 (input) neurons and the Layer 5 (output) neurons using a previously developed generalized Volterra model (GVM). Input-output spike trains are recorded from the PFCs of nonhuman primates performing a memory-dependent delayed match-to-sample task with a customized conformal ceramic multi-electrode array. The GVM describes how the input spike trains are transformed into the output spike trains by the PFC micro-circuitry and represents the transformation in the form of Volterra kernels. Results show that Layer 2/3 neurons have strong and transient facilitatory effects on the firings of Layer 5 neurons. The magnitude and temporal range of the input-output nonlinear dynamics are strikingly different from those of the hippocampal CA3-CA1. This form of functional connectivity may have important implications to understanding the computational principle of the PFC.

  1. Electromyographic preactivation pattern of the gluteus medius during weight-bearing functional tasks in women with and without anterior knee pain.

    Science.gov (United States)

    Nakagawa, Theresa H; Muniz, Thiago B; Baldon, Rodrigo M; Maciel, Carlos D; Amorim, César F; Serrão, Fábio V

    2011-01-01

    Proximal factors have been proposed to influence the biomechanics of the patellofemoral joint. A delayed or diminished gluteus medius (GM) activation, before the foot contact on the ground during functional activities could lead to excessive femur adduction and internal rotation and be associated with anterior knee pain (AKP). There are few studies on this topic and the results were inconclusive, therefore, it is necessary to investigate the GM preactivation pattern during functional activities. To compare the GM electromyographic (EMG) preactivation pattern during walking, descending stairs and in single leg jump task in women with and without AKP. Nine women clinically diagnosed with AKP and ten control subjects with no history of knee injury participated in this study. We evaluated GM EMG linear envelope before the foot contact on the ground during walking and GM onset time and EMG linear envelope during descending stairs as well as in a single leg vertical jump. Mann-Whitney U tests were used to determine the between-group differences in GM EMG preactivation pattern. No between-group differences were observed in GM linear envelope during walking (P=0.41), GM onset time and linear envelope during descending stairs (P=0.17 and P=0.15) and single leg jump (P=0.81 and P=0.33). Women with AKP did not demonstrated altered GM preactivation pattern during functional weight bearing activities. Our results did not support the hypothesis that poor GM preactivation pattern could be associated with AKP.

  2. Exploring the Incorporation of Executive Functions in Intelligence Testing: Factor Analysis of the WAIS-III and Traditional Tasks of Executive Functioning

    OpenAIRE

    Aken, L. van; R.P.C. Kessels; Wingbermühle, P.A.M.; Wiltink, M.; Heijden, P.T. van der; Egger, J.I.M.

    2014-01-01

    The aim of this study was to examine the relationship between subtests of the Wechsler Adult Intelligence Scale – third edition (WAIS-III) and executive functions. The Behavioural Assessment of the Dysexecutive Syndrome, Wisconsin Card Sorting Test, and Stroop Color-Word Test were administered to a heterogeneous group of 234 psychiatric patients and 24 healthy volunteers. Maximum likelihood procedures with promax rotation were applied to two, three and four factor solutions. The four factor m...

  3. Task-focused modeling in automated agriculture

    Science.gov (United States)

    Vriesenga, Mark R.; Peleg, K.; Sklansky, Jack

    1993-01-01

    Machine vision systems analyze image data to carry out automation tasks. Our interest is in machine vision systems that rely on models to achieve their designed task. When the model is interrogated from an a priori menu of questions, the model need not be complete. Instead, the machine vision system can use a partial model that contains a large amount of information in regions of interest and less information elsewhere. We propose an adaptive modeling scheme for machine vision, called task-focused modeling, which constructs a model having just sufficient detail to carry out the specified task. The model is detailed in regions of interest to the task and is less detailed elsewhere. This focusing effect saves time and reduces the computational effort expended by the machine vision system. We illustrate task-focused modeling by an example involving real-time micropropagation of plants in automated agriculture.

  4. Effect of computerized cognitive training with virtual spatial navigation task during bed rest immobilization and recovery on vascular function: A pilot study

    Directory of Open Access Journals (Sweden)

    Goswami N

    2015-02-01

    Full Text Available Nandu Goswami,1 Voyko Kavcic,2 Uros Marusic,3 Bostjan Simunic,3 Andreas Rössler,1 Helmut Hinghofer-Szalkay,1 Rado Pisot3 1Institute of Physiology, Medical University of Graz, Graz, Austria; 2Institute of Gerontology, Wayne State University, Detroit, MI, USA; 3Institute for Kinesiology Research, University of Primorska, Ankaran, Slovenia Abstract: We investigated the effects of bed rest (BR immobilization, with and without computerized cognitive training with virtual spatial navigation task (CCT, on vascular endothelium on older subjects. The effects of 14-day BR immobilization in healthy older males (n=16 of ages 53–65 years on endothelial function were studied using EndoPAT®, a noninvasive and user-independent method. From the group of 16 older men, 8 randomly received CCT during the BR, using virtual navigation tasks in a virtual environment with joystick device. In all the cases, EndoPAT assessments were done at pre- and post-BR immobilization as well as following 28 days of ambulatory recovery. The EndoPAT index increased from 1.53±0.09 (mean ± standard error of the mean at baseline to 1.61±0.16 following immobilization (P=0.62 in the group with CCT. The EndoPAT index decreased from 2.06±0.13 (mean ± standard error of the mean at baseline to 1.70±0.09 at the last day of BR study, day 14 (BR14 (P=0.09 in the control group. Additionally, there were no statistically significant differences between BR14 and at 28 days of follow-up (rehabilitation program (R28. Our results show a trend of immobilization in older persons affecting the vasoconstrictory endothelial response. As the control subjects had a greater increase in EndoPAT index after R28 (+0.018 compared to subjects who had cognitive training (+0.11 (calculated from the first day of BR study, it is possible that cognitive training during BR does not improve endothelial function but rather contributes to slowing down the impairment of endothelial function. Finally, our results

  5. Procedural and declarative memory task performance, and the memory consolidation function of sleep, in recent and abstinent ecstasy/MDMA users.

    Science.gov (United States)

    Blagrove, Mark; Seddon, Jennifer; George, Sophie; Parrott, Andrew C; Stickgold, Robert; Walker, Matthew P; Jones, Katy A; Morgan, Michael J

    2011-04-01

    Ecstasy/MDMA use has been associated with various memory deficits. This study assessed declarative and procedural memory in ecstasy/MDMA users. Participants were tested in two sessions, 24 h apart, so that the memory consolidation function of sleep on both types of memory could also be assessed. Groups were: drug-naive controls (n = 24); recent ecstasy/MDMA users, who had taken ecstasy/MDMA 2-3 days before the first testing session (n = 25), and abstinent users, who had not taken ecstasy/MDMA for at least 8 days before testing (n = 17). Procedural memory did not differ between groups, but greater lifetime consumption of ecstasy was associated with poorer procedural memory. Recent ecstasy/MDMA users who had taken other drugs (mainly cannabis) 48-24 h before testing exhibited poorer declarative memory than controls, but recent users who had not taken other drugs in this 48-24-h period did not differ from controls. Greater lifetime consumption of ecstasy, and of cocaine, were associated with greater deficits in declarative memory. These results suggest that procedural, as well as declarative, memory deficits are associated with the extent of past ecstasy use. However, ecstasy/MDMA did not affect the memory consolidation function of sleep for either the declarative or the procedural memory task.

  6. Dual learning processes underlying human decision-making in reversal learning tasks: Functional significance and evidence from the model fit to human behavior

    Directory of Open Access Journals (Sweden)

    Yu eBai

    2014-08-01

    Full Text Available Humans are capable of correcting their actions based on actions performed in the past, and this ability enables them to adapt to a changing environment. The computational field of reinforcement learning (RL has provided a powerful explanation for understanding such processes. Recently, the dual learning system, modeled as a hybrid model that incorporates value update based on reward-prediction error and learning rate modulation based on the surprise signal, has gained attention as a model for explaining various neural signals. However, the functional significance of the hybrid model has not been established. In the present study, we used computer simulation in a reversal learning task to address functional significance. The hybrid model was found to perform better than the standard RL model in a large parameter setting. These results suggest that the hybrid model is more robust against mistuning of parameters compared to the standard RL model when decision makers continue to learn stimulus-reward contingencies, which make an abrupt changes. The parameter fitting results also indicated that the hybrid model fit better than the standard RL model for more than 50% of the participants, which suggests that the hybrid model has more explanatory power for the behavioral data than the standard RL model.

  7. Priming for Improved Hand Strength in Persons with Chronic Tetraplegia: A Comparison of Priming-Augmented Functional Task Practice, Priming Alone, and Conventional Exercise Training

    Science.gov (United States)

    Gomes-Osman, Joyce; Tibbett, Jacqueline A.; Poe, Brandon P.; Field-Fote, Edelle C.

    2017-01-01

    Many everyday tasks cannot be accomplished without adequate grip strength, and corticomotor drive to the spinal motoneurons is a key determinant of grip strength. In persons with tetraplegia, damage to spinal pathways limits transmission of signals from motor cortex to spinal motoneurons. Corticomotor priming, which increases descending drive, should increase corticospinal transmission through the remaining spinal pathways resulting in increased grip strength. Since the motor and somatosensory cortices share reciprocal connections, corticomotor priming may also have potential to influence somatosensory function. The purpose of this study was to assess changes in grip (precision, power) force and tactile sensation associated with two different corticomotor priming approaches and a conventional training approach and to determine whether baseline values can predict responsiveness to training. Participants with chronic (≥1 year) tetraplegia (n = 49) were randomized to one of two corticomotor priming approaches: functional task practice plus peripheral nerve somatosensory stimulation (FTP + PNSS) or PNSS alone, or to conventional exercise training (CET). To assess whether baseline corticospinal excitability (CSE) is predictive of responsiveness to training, in a subset of participants, we assessed pre-intervention CSE of the thenar muscles. Participants were trained 2 h daily, 5 days/week for 4 weeks. Thirty-seven participants completed the study. Following intervention, significant improvements in precision grip force were observed in both the stronger and weaker hand in the FTP + PNSS group (effect size: 0.51, p = 0.04 and 0.54, p = 0.03, respectively), and significant improvements in weak hand precision grip force were associated with both PNSS and CET (effect size: 0.54, p = 0.03 and 0.75, p = 0.02, respectively). No significant changes were observed in power grip force or somatosensory scores in any group. Across all groups

  8. Priming for Improved Hand Strength in Persons with Chronic Tetraplegia: A Comparison of Priming-Augmented Functional Task Practice, Priming Alone, and Conventional Exercise Training.

    Science.gov (United States)

    Gomes-Osman, Joyce; Tibbett, Jacqueline A; Poe, Brandon P; Field-Fote, Edelle C

    2016-01-01

    Many everyday tasks cannot be accomplished without adequate grip strength, and corticomotor drive to the spinal motoneurons is a key determinant of grip strength. In persons with tetraplegia, damage to spinal pathways limits transmission of signals from motor cortex to spinal motoneurons. Corticomotor priming, which increases descending drive, should increase corticospinal transmission through the remaining spinal pathways resulting in increased grip strength. Since the motor and somatosensory cortices share reciprocal connections, corticomotor priming may also have potential to influence somatosensory function. The purpose of this study was to assess changes in grip (precision, power) force and tactile sensation associated with two different corticomotor priming approaches and a conventional training approach and to determine whether baseline values can predict responsiveness to training. Participants with chronic (≥1 year) tetraplegia (n = 49) were randomized to one of two corticomotor priming approaches: functional task practice plus peripheral nerve somatosensory stimulation (FTP + PNSS) or PNSS alone, or to conventional exercise training (CET). To assess whether baseline corticospinal excitability (CSE) is predictive of responsiveness to training, in a subset of participants, we assessed pre-intervention CSE of the thenar muscles. Participants were trained 2 h daily, 5 days/week for 4 weeks. Thirty-seven participants completed the study. Following intervention, significant improvements in precision grip force were observed in both the stronger and weaker hand in the FTP + PNSS group (effect size: 0.51, p = 0.04 and 0.54, p = 0.03, respectively), and significant improvements in weak hand precision grip force were associated with both PNSS and CET (effect size: 0.54, p = 0.03 and 0.75, p = 0.02, respectively). No significant changes were observed in power grip force or somatosensory scores in any group. Across all groups

  9. Dashboard Task Monitor for managing ATLAS user analysis on the Grid

    CERN Document Server

    Sargsyan, L; The ATLAS collaboration; Jha, M; Karavakis, E; Kokoszkiewicz, L; Saiz, P; Schovancova, J; Tuckett, D

    2013-01-01

    The organization of the distributed user analysis on the Worldwide LHC Computing Grid (WLCG) infrastructure is one of the most challenging tasks among the computing activities at the Large Hadron Collider. The Experiment Dashboard offers a solution that not only monitors but also manages (kill, resubmit) user tasks and jobs via a web interface. The ATLAS Dashboard Task Monitor provides analysis users with a tool that is operating system and GRID environment independent. This contribution describes the functionality of the application and its implementation details, in particular authentication, authorization and audit of the management operations.

  10. Dashboard Task Monitor for managing ATLAS user analysis on the Grid

    CERN Document Server

    Sargsyan, L; Jha, M; Karavakis, E; Kokoszkiewicz, L; Saiz, P; Schovancova, J; Tuckett, D

    2014-01-01

    The organization of the distributed user analysis on the Worldwide LHC Computing Grid (WLCG) infrastructure is one of the most challenging tasks among the computing activities at the Large Hadron Collider. The Experiment Dashboard offers a solution that not only monitors but also manages (kill, resubmit) user tasks and jobs via a web interface. The ATLAS Dashboard Task Monitor provides analysis users with a tool that is independent of the operating system and GRID environment . This contribution describes the functionality of the application and its implementation details, in particular authentication, authorization and audit of the management operations.

  11. Dashboard Task Monitor for Managing ATLAS User Analysis on the Grid

    Science.gov (United States)

    Sargsyan, L.; Andreeva, J.; Jha, M.; Karavakis, E.; Kokoszkiewicz, L.; Saiz, P.; Schovancova, J.; Tuckett, D.; Atlas Collaboration

    2014-06-01

    The organization of the distributed user analysis on the Worldwide LHC Computing Grid (WLCG) infrastructure is one of the most challenging tasks among the computing activities at the Large Hadron Collider. The Experiment Dashboard offers a solution that not only monitors but also manages (kill, resubmit) user tasks and jobs via a web interface. The ATLAS Dashboard Task Monitor provides analysis users with a tool that is independent of the operating system and Grid environment. This contribution describes the functionality of the application and its implementation details, in particular authentication, authorization and audit of the management operations.

  12. Excitotoxic lesions of the medial striatum delay extinction of a reinforcement color discrimination operant task in domestic chicks; a functional role of reward anticipation.

    Science.gov (United States)

    Ichikawa, Yoko; Izawa, Ei-Ichi; Matsushima, Toshiya

    2004-12-01

    To reveal the functional roles of the striatum, we examined the effects of excitotoxic lesions to the bilateral medial striatum (mSt) and nucleus accumbens (Ac) in a food reinforcement color discrimination operant task. With a food reward as reinforcement, 1-week-old domestic chicks were trained to peck selectively at red and yellow beads (S+) and not to peck at a blue bead (S-). Those chicks then received either lesions or sham operations and were tested in extinction training sessions, during which yellow turned out to be nonrewarding (S-), whereas red and blue remained unchanged. To further examine the effects on postoperant noninstrumental aspects of behavior, we also measured the "waiting time", during which chicks stayed at the empty feeder after pecking at yellow. Although the lesioned chicks showed significantly higher error rates in the nonrewarding yellow trials, their postoperant waiting time gradually decreased similarly to the sham controls. Furthermore, the lesioned chicks waited significantly longer than the controls, even from the first extinction block. In the blue trials, both lesioned and sham chicks consistently refrained from pecking, indicating that the delayed extinction was not due to a general disinhibition of pecking. Similarly, no effects were found in the novel training sessions, suggesting that the lesions had selective effects on the extinction of a learned operant. These results suggest that a neural representation of memory-based reward anticipation in the mSt/Ac could contribute to the anticipation error required for extinction.

  13. Functional Laterality of Task-Evoked Activation in Sensorimotor Cortex of Preterm Infants: An Optimized 3 T fMRI Study Employing a Customized Neonatal Head Coil

    Science.gov (United States)

    Smith-Collins, Adam PR; Müller, Nicole; Stegmann-Woessner, Gaby; Jankowski, Jacob; Gieseke, Jürgen; Born, Mark; Seitz, Hermann; Bartmann, Peter; Schild, Hans H.; Pruessmann, Klaas P.; Boecker, Henning

    2017-01-01

    Background Functional magnetic resonance imaging (fMRI) in neonates has been introduced as a non-invasive method for studying sensorimotor processing in the developing brain. However, previous neonatal studies have delivered conflicting results regarding localization, lateralization, and directionality of blood oxygenation level dependent (BOLD) responses in sensorimotor cortex (SMC). Amongst the confounding factors in interpreting neonatal fMRI studies include the use of standard adult MR-coils providing insufficient signal to noise, and liberal statistical thresholds, compromising clinical interpretation at the single subject level. Patients / methods Here, we employed a custom-designed neonatal MR-coil adapted and optimized to the head size of a newborn in order to improve robustness, reliability and validity of neonatal sensorimotor fMRI. Thirteen preterm infants with a median gestational age of 26 weeks were scanned at term-corrected age using a prototype 8-channel neonatal head coil at 3T (Achieva, Philips, Best, NL). Sensorimotor stimulation was elicited by passive extension/flexion of the elbow at 1 Hz in a block design. Analysis of temporal signal to noise ratio (tSNR) was performed on the whole brain and the SMC, and was compared to data acquired with an ‘adult’ 8 channel head coil published previously. Task-evoked activation was determined by single-subject SPM8 analyses, thresholded at p lateralization of SMC activation, as found in children and adults, is already present in the newborn period. PMID:28076368

  14. A detailed coupled-mode-space non-equilibrium Green's function simulation study of source-to-drain tunnelling in gate-all-around Si nanowire metal oxide semiconductor field effect transistors

    Science.gov (United States)

    Seoane, N.; Martinez, A.

    2013-09-01

    In this paper we present a 3D quantum transport simulation study of source-to-drain tunnelling in gate-all-around Si nanowire transistors by using the non-equilibrium Green's function approach. The impact of the channel length, device cross-section, and drain and gate applied biases on the source-to-drain tunnelling is examined in detail. The overall effect of tunnelling on the ID-VG characteristics is also investigated. Tunnelling in devices with channel lengths of 10 nm or less substantially enhances the off-current. This enhancement is more important at high drain biases and at larger cross-sections where the sub-threshold slope is substantially degraded. A less common effect is the increase in the on-current due to the tunnelling which contributes as much as 30% of the total on-current. This effect is almost independent of the cross-section, and it depends weakly on the studied channel lengths.

  15. Syntactic Complexity, Lexical Variation and Accuracy as a Function of Task Complexity and Proficiency Level in L2 Writing and Speaking

    Science.gov (United States)

    Kuiken, Folkert; Vedder, Ineke

    2012-01-01

    The research project reported in this chapter consists of three studies in which syntactic complexity, lexical variation and fluency appear as dependent variables. The independent variables are task complexity and proficiency level, as the three studies investigate the effect of task complexity on the written and oral performance of L2 learners of…

  16. Syntactic complexity, lexical variation and accuracy as a function of task complexity and proficiency level in L2 writing and speaking

    NARCIS (Netherlands)

    Kuiken, F.; Vedder, I.; Housen, A.; Kuiken, F.; Vedder, I.

    2012-01-01

    The research project reported in this chapter consists of three studies in which syntactic complexity, lexical variation and fluency appear as dependent variables. The independent variables are task complexity and proficiency level, as the three studies investigate the effect of task complexity on t

  17. Functional Magnetic Resonance Imaging Study of Piaget's Conservation-of-Number Task in Preschool and School-Age Children: A Neo-Piagetian Approach

    Science.gov (United States)

    Houde, Olivier; Pineau, Arlette; Leroux, Gaelle; Poirel, Nicolas; Perchey, Guy; Lanoe, Celine; Lubin, Amelie; Turbelin, Marie-Renee; Rossi, Sandrine; Simon, Gregory; Delcroix, Nicolas; Lamberton, Franck; Vigneau, Mathieu; Wisniewski, Gabriel; Vicet, Jean-Rene; Mazoyer, Bernard

    2011-01-01

    Jean Piaget's theory is a central reference point in the study of logico-mathematical development in children. One of the most famous Piagetian tasks is number conservation. Failures and successes in this task reveal two fundamental stages in children's thinking and judgment, shifting at approximately 7 years of age from visuospatial intuition to…

  18. Functional Magnetic Resonance Imaging Study of Piaget's Conservation-of-Number Task in Preschool and School-Age Children: A Neo-Piagetian Approach

    Science.gov (United States)

    Houde, Olivier; Pineau, Arlette; Leroux, Gaelle; Poirel, Nicolas; Perchey, Guy; Lanoe, Celine; Lubin, Amelie; Turbelin, Marie-Renee; Rossi, Sandrine; Simon, Gregory; Delcroix, Nicolas; Lamberton, Franck; Vigneau, Mathieu; Wisniewski, Gabriel; Vicet, Jean-Rene; Mazoyer, Bernard

    2011-01-01

    Jean Piaget's theory is a central reference point in the study of logico-mathematical development in children. One of the most famous Piagetian tasks is number conservation. Failures and successes in this task reveal two fundamental stages in children's thinking and judgment, shifting at approximately 7 years of age from visuospatial intuition to…

  19. Language-specific cortical activation patterns for verbal fluency tasks in Japanese as assessed by multichannel functional near-infrared spectroscopy.

    Science.gov (United States)

    Dan, Haruka; Dan, Ippeita; Sano, Toshifumi; Kyutoku, Yasushi; Oguro, Keiji; Yokota, Hidenori; Tsuzuki, Daisuke; Watanabe, Eiju

    2013-08-01

    In Japan, verbal fluency tasks are commonly utilized as a standard paradigm for neuropsychological testing of cognitive and linguistic abilities. The Japanese "letter fluency task" is a mora/letter fluency task based on the phonological and orthographical characteristics of the Japanese language. Whether there are similar activation patterns across languages or a Japanese-specific mora/letter fluency pattern is not certain. We investigated the neural correlates of overt mora/letter and category fluency tasks in healthy Japanese. The category fluency task activated the bilateral fronto-temporal language-related regions with left-superior lateralization, while the mora/letter fluency task led to wider activation including the inferior parietal regions (left and right supramarginal gyrus). Specific bilateral supramarginal activation during the mora/letter fluency task in Japanese was distinct from that of similar letter fluency tasks in syllable-alphabet-based languages: this might be due to the requirement of additional phonological processing and working memory, or due to increased cognitive load in general.

  20. Computed tomography:the details.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2007-07-01

    Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

  1. A dual-task paradigm for behavioral and neurobiological studies in nonhuman primates.

    Science.gov (United States)

    Watanabe, Kei; Funahashi, Shintaro

    2015-05-15

    The dual-task paradigm is a procedure in which subjects are asked to perform two behavioral tasks concurrently, each of which involves a distinct goal with a unique stimulus-response association. Due to the heavy demand on subject's cognitive abilities, human studies using this paradigm have provided detailed insights regarding how the components of cognitive systems are functionally organized and implemented. Although dual-task paradigms are widely used in human studies, they are seldom used in nonhuman animal studies. We propose a novel dual-task paradigm for monkeys that requires the simultaneous performance of two cognitively demanding component tasks, each of which uses an independent effector for behavioral responses (hand and eyes). We provide a detailed description of an optimal training protocol for this paradigm, which has been lacking in the existing literature. An analysis of behavioral performance showed that the proposed dual-task paradigm (1) was quickly learned by monkeys (less than 40 sessions) with step-by-step training protocols, (2) produced specific behavioral effects, known as dual-task interference in human studies, and (3) achieved rigid and independent control of the effectors for behavioral responses throughout the trial. The proposed dual-task paradigm has a scalable task structure, in that each of the two component tasks can be easily replaced by other tasks, while preserving the overall structure of the paradigm. This paradigm should be useful for investigating executive control that underlies dual-task performance at both the behavioral and neuronal levels. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Phonetic Detail in American English

    Institute of Scientific and Technical Information of China (English)

    Ray Freeze

    1987-01-01

    @@ In the course of teaching general phonetics and phonological analysis in the psat few years,l have found some phonetic detail which some native speakers as well as non-native speakers were unaware of. This subtle detail will be the focus of this presentation. Som e of this detail many of you will already be aware of because of your experience in learning, teaching, and thinking about English. If anything is new to you, I hope you might enjoy hearing about it even if it turns out not to be useful in your work.

  3. Equal prefrontal cortex activation between males and females in a motor tasks and different visual imagery perspectives: a functional near-infrared spectroscopy (fNIRS study

    Directory of Open Access Journals (Sweden)

    Thiago F. Dias Kanthack

    2013-09-01

    Full Text Available The purpose of this study was to compare the prefrontal cortex (PFC blood flow variation and time on in males and females while performing a motor task and imagery perspectives. Eighteen right handed subjects (11 males and 7 females were volunteers to this study. All subjects went through three randomly conditions, a motor task condition (MT in which they had to do a simple finger tap. The other conditions included practicing imagery in first and third views. During all the conditions, the fNIRS device was attached to the subject forehead to obtain the blood flow; the total time in each task which was measured with a chronometer. No difference had been found in any condition for both sexes in the PFC and time, nor for all subjects integrated in the PFC. Therefore, we conclu-de that both imageries can be used to mentally train a motor task, and probably both sexes can be benefited.

  4. A Meta-analysis on the neural basis of planning: Activation likelihood estimation of functional brain imaging results in the Tower of London task.

    Science.gov (United States)

    Nitschke, Kai; Köstering, Lena; Finkel, Lisa; Weiller, Cornelius; Kaller, Christoph P

    2017-01-01

    The ability to mentally design and evaluate series of future actions has often been studied in terms of planning abilities, commonly using well-structured laboratory tasks like the Tower of London (ToL). Despite a wealth of studies, findings on the specific localization of planning processes within prefrontal cortex (PFC) and on the hemispheric lateralization are equivocal. Here, we address this issue by integrating evidence from two different sources of data: First, we provide a systematic overview of the existing lesion data on planning in the ToL (10 studies, 211 patients) which does not indicate any evidence for a general lateralization of planning processes in (pre)frontal cortex. Second, we report a quantitative meta-analysis with activation likelihood estimation based on 31 functional neuroimaging datasets on the ToL. Separate meta-analyses of the activation patterns reported for Overall Planning (537 participants) and for Planning Complexity (182 participants) congruently show bilateral contributions of mid-dorsolateral PFC, frontal eye fields, supplementary motor area, precuneus, caudate, anterior insula, and inferior parietal cortex in addition to a left-lateralized involvement of rostrolateral PFC. In contrast to previous attributions of planning-related brain activity to the entire dorsolateral prefrontal cortex (dlPFC) and either its left or right homolog derived from single studies on the ToL, the present meta-analyses stress the pivotal role specifically of the mid-dorsolateral part of PFC (mid-dlPFC), presumably corresponding to Brodmann Areas 46 and 9/46, and strongly argue for a bilateral rather than lateralized involvement of the dlPFC in planning in the ToL. Hum Brain Mapp 38:396-413, 2017. © 2016 Wiley Periodicals, Inc.

  5. A technique to train new oculomotor behavior in patients with central macular scotomas during reading related tasks using scanning laser ophthalmoscopy: immediate functional benefits and gains retention

    Directory of Open Access Journals (Sweden)

    Lorincz Erika N

    2006-11-01

    Full Text Available Abstract Background Reading with a central scotoma involves the use of preferred retinal loci (PRLs that enable both letter resolution and global viewing of word. Spontaneously developed PRLs however often privilege spatial resolution and, as a result, visual span is commonly limited by the position of the scotoma. In this study we designed and performed the pilot trial of a training procedure aimed at modifying oculomotor behavior in subjects with central field loss. We use an additional fixation point which, when combined with the initial PRL, allows the fulfillment of both letter resolution and global viewing of words. Methods The training procedure comprises ten training sessions conducted with the scanning laser ophthalmoscope (SLO. Subjects have to read single letters and isolated words varying in length, by combining the use of their initial PRL with the one of an examiner's selected trained retinal locus (TRL. We enrolled five subjects to test for the feasibility of the training technique. They showed stable maculopathy and persisting major reading difficulties despite previous orthoptic rehabilitation. We evaluated ETDRS visual acuity, threshold character size for single letters and isolated words, accuracy for paragraphed text reading and reading strategies before, immediately after SLO training, and three months later. Results Training the use of multiple PRLs in patients with central field loss is feasible and contributes to adapt oculomotor strategies during reading related tasks. Immediately after SLO training subjects used in combination with their initial PRL the examiner's selected TRL and other newly self-selected PRLs. Training gains were also reflected in ETDRS acuity, threshold character size for words of different lengths and in paragraphed text reading. Interestingly, subjects benefited variously from the training procedure and gains were retained differently as a function of word length. Conclusion We designed a new

  6. Short-Term Effects of Whole-Body Vibration Combined with Task-Related Training on Upper Extremity Function, Spasticity, and Grip Strength in Subjects with Poststroke Hemiplegia: A Pilot Randomized Controlled Trial.

    Science.gov (United States)

    Lee, Jung-Sun; Kim, Chang-Yong; Kim, Hyeong-Dong

    2016-08-01

    The aim of this study was to determine the effect of whole-body vibration training combined with task-related training on arm function, spasticity, and grip strength in subjects with poststroke hemiplegia. Forty-five subjects with poststroke were randomly allocated to 3 groups, each with 15 subjects as follows: control group, whole-body vibration group, and whole-body vibration plus task-related training group. Outcome was evaluated by clinical evaluation and measurements of the grip strength before and 4 weeks after intervention. Our results show that there was a significantly greater increase in the Fugl-Meyer scale, maximal grip strength of the affected hand, and grip strength normalized to the less affected hand in subjects undergoing the whole-body vibration training compared with the control group after the test. Furthermore, there was a significantly greater increase in the Wolf motor function test and a decrease in the modified Ashworth spasticity total scores in subjects who underwent whole-body vibration plus task-related training compared with those in the other 2 groups after the test. The findings indicate that the use of whole-body vibration training combined with task-related training has more benefits on the improvement of arm function, spasticity, and maximal grip strength than conventional upper limb training alone or with whole-body vibration in people with poststroke hemiplegia.

  7. Functional and molecular identification of a TASK-1 potassium channel regulating chloride secretion through CFTR channels in the shark rectal gland: implications for cystic fibrosis.

    Science.gov (United States)

    Telles, Connor J; Decker, Sarah E; Motley, William W; Peters, Alexander W; Mehr, Ali Poyan; Frizzell, Raymond A; Forrest, John N

    2016-12-01

    In the shark rectal gland (SRG), apical chloride secretion through CFTR channels is electrically coupled to a basolateral K(+) conductance whose type and molecular identity are unknown. We performed studies in the perfused SRG with 17 K(+) channel inhibitors to begin this search. Maximal chloride secretion was markedly inhibited by low-perfusate pH, bupivicaine, anandamide, zinc, quinidine, and quinine, consistent with the properties of an acid-sensitive, four-transmembrane, two-pore-domain K(+) channel (4TM-K2P). Using PCR with degenerate primers to this family, we identified a TASK-1 fragment in shark rectal gland, brain, gill, and kidney. Using 5' and 3' rapid amplification of cDNA ends PCR and genomic walking, we cloned the full-length shark gene (1,282 bp), whose open reading frame encodes a protein of 375 amino acids that was 80% identical to the human TASK-1 protein. We expressed shark and human TASK-1 cRNA in Xenopus oocytes and characterized these channels using two-electrode voltage clamping. Both channels had identical current-voltage relationships (outward rectifying) and a reversal potential of -90 mV. Both were inhibited by quinine, bupivicaine, and acidic pH. The pKa for current inhibition was 7.75 for shark TASK-1 vs. 7.37 for human TASK-1, values similar to the arterial pH for each species. We identified this protein in SRG by Western blot and confocal immunofluorescent microscopy and detected the protein in SRG and human airway cells. Shark TASK-1 is the major K(+) channel coupled to chloride secretion in the SRG, is the oldest 4TM 2P family member identified, and is the first TASK-1 channel identified to play a role in setting the driving force for chloride secretion in epithelia. The detection of this potassium channel in mammalian lung tissue has implications for human biology and disease.

  8. Consolidation of Associative and Item Memory Is Related to Post-Encoding Functional Connectivity between the Ventral Tegmental Area and Different Medial Temporal Lobe Subregions during an Unrelated Task.

    Science.gov (United States)

    Tompary, Alexa; Duncan, Katherine; Davachi, Lila

    2015-05-13

    It is well established that the hippocampus and perirhinal cortex (PrC) encode associative and item representations, respectively. However, less is known about how item and associative memories are consolidated. We used high-resolution fMRI in humans to measure how functional connectivity between these distinct medial temporal lobe regions with the ventral tegmental area (VTA) after a paired associate encoding task is related to both immediate and 24 h item and associative memory performance. We found that the strength of post-encoding functional connectivity between the VTA and CA1 selectively correlated with long-term associative memory, despite subjects actively engaging in an unrelated task during this period. Conversely, VTA-PrC functional connectivity during the same period correlated with long-term item memory. Critically, connectivity between VTA and these MTL regions were only related to memory tested at a 24 h delay, implicating midbrain connectivity in the consolidation of distinct forms of memory.

  9. Review of Ship Structural Details

    Science.gov (United States)

    1977-01-01

    8 4.3 Knee and Beam Brackets 4-11 4.3.1 Brackets for Girders and Deep Webs 4-11 4.3.2 Brackets Connecting Rolled Sections 4-15 4.4 Tripping...are shell stringers penetrating deep web frames and longitudinal girders penetrating deep transverses. This is not a common detail. If double...34. 3-76 ^"SECTION ’’.’(-K PLAJ iNG * S v *^ 4Fb^:TH»r.KNF.^ SAME AS FLAMGE ► BULKHFADQR DEEP WEB SS- 9 Detail Type: STANCHION END

  10. Detail in architecture: Between arts

    Directory of Open Access Journals (Sweden)

    Dulencin Juraj

    2016-06-01

    Full Text Available Architectural detail represents an important part of architecture. Not only can it be used as an identifier of a specific building but at the same time enhances the experience of the realized project. Within it lie the signs of a great architect and clues to understanding his or her way of thinking. It is therefore the central topic of a seminar offered to architecture students at the Brno University of Technology. During the course of the semester-long class the students acquaint themselves with atypical architectural details of domestic and international architects by learning to read them, understand them and subsequently draw them by creating architectural blueprints. In other words, by general analysis of a detail the students learn theoretical thinking of its architect who, depending on the nature of the design, had to incorporate a variety of techniques and crafts. Students apply this analytical part to their own architectural detail design. The methodology of the seminar consists of experiential learning by project management and is complemented by a series of lectures discussing a diversity of details as well as materials and technologies required to implement it. The architectural detail design is also part of students’ bachelors thesis, therefore, the realistic nature of their blueprints can be verified in the production process of its physical counterpart. Based on their own documentation the students choose the most suitable manufacturing process whether it is supplied by a specific technology or a craftsman. Students actively participate in the production and correct their design proposals in real scale with the actual material. A student, as a future architect, stands somewhere between a client and an artisan, materializes his or her idea and adjusts the manufacturing process so that the final detail fulfills aesthetic consistency and is in harmony with its initial concept. One of the very important aspects of the design is its

  11. Transformative Dynamics in Detailed Planning

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Poulsen, Naja; Gustavsson, Ted

    that the translation process relies heavily on integration of impositions in the detailed plan, although this has clear limitations, since some sustainable strategies are more difficult to impose than others. It also shows how strategic navigation may represent an alternative translation strategy to promote more...... difficult sustainable strategies that address the project design more directly. In conclusion, the paper argues that strategic navigation represents a stronger mediator of change compared to the detailed plan, but that especially timing issues in the coordination between formal planning and design processes...

  12. DAGAL: Detailed Anatomy of Galaxies

    Science.gov (United States)

    Knapen, Johan H.

    2017-03-01

    The current IAU Symposium is closely connected to the EU-funded network DAGAL (Detailed Anatomy of Galaxies), with the final annual network meeting of DAGAL being at the core of this international symposium. In this short paper, we give an overview of DAGAL, its training activities, and some of the scientific advances that have been made under its umbrella.

  13. DAGAL: Detailed Anatomy of Galaxies

    CERN Document Server

    Knapen, Johan H

    2016-01-01

    The current IAU Symposium is closely connected to the EU-funded network DAGAL (Detailed Anatomy of Galaxies), with the final annual network meeting of DAGAL being at the core of this international symposium. In this short paper, we give an overview of DAGAL, its training activities, and some of the scientific advances that have been made under its umbrella.

  14. On Detailing in Contemporary Architecture