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Sample records for surround visuospatial processing

  1. Visuospatial Processing in Children with Neurofibromatosis Type 1

    Science.gov (United States)

    Clements-Stephens, Amy M.; Rimrodt, Sheryl L.; Gaur, Pooja; Cutting, Laurie E.

    2008-01-01

    Neuroimaging studies investigating the neural network of visuospatial processing have revealed a right hemisphere network of activation including inferior parietal lobe, dorsolateral prefrontal cortex, and extrastriate regions. Impaired visuospatial processing, indicated by the Judgment of Line Orientation (JLO), is commonly seen in individuals…

  2. Updating verbal and visuospatial working memory: Are the processes parallel?

    Institute of Scientific and Technical Information of China (English)

    YUE ZhenZhu; ZHANG Ming; ZHOU XiaoLin

    2008-01-01

    The current study compared the processes of updating verbal and visuospatial working memory (WM) and examined the roles of central executive and slave systems in working memory updating tasks, by changing the number of items updated simultaneously to manipulate the load on central executive. Ex-periment 1 used the verbal WM updating task, and the results validated the efficiency of the paradigm to manipulate the load on central executive. Experiment 2 employed the verbal WM updating task, with the articulatory suppression task to interfere with the phonological loop. The results supported the study by Morris and Jones, revealing that the central executive system played an important role in the updating component of verbal WM, while the phonological loop was responsible for the serial recall component. Experiment 3 employed the visuospatial WM updating task, with the spatial tapping task to interfere with the visuospatial sketchpad. The results suggested that the visuospatial sketchpad and the central execu-tive together dealt with the updating component, while the visuospatial sketchpad was responsible for the serial recall component by itself. These results are consistent with the findings that visuospatial sketch-pad has close links with central executive, while the phonological loop is separated from the central ex-ecutive. It suggests that updating visuospatial and verbal WM are not two parallel processes.

  3. Conservation Abilities, Visuospatial Skills, and Numerosity Processing Speed.

    Science.gov (United States)

    Lambert, Katharina; Spinath, Birgit

    2017-01-01

    The aim of the present study was to investigate the associations between elementary school children's mathematical achievement and their conservation abilities, visuospatial skills, and numerosity processing speed. We also assessed differences in these abilities between children with different types of learning problems. In Study 1 ( N = 229), we investigated second to fourth graders and in Study 2 ( N = 120), third and fourth graders. Analyses revealed significant contributions of numerosity processing speed and visuospatial skills to math achievement beyond IQ. Conservation abilities were predictive in Study 1 only. Children with math difficulties showed lower visuospatial skills and conservation abilities than children with typical achievement levels and children with reading and/or spelling difficulties, whereas children with combined difficulties explicitly showed low conservation abilities. These findings provide further evidence for the relations between children's math skills and their visuospatial skills, conservation abilities, and processing speed and contribute to the understanding of deficits that are specific to mathematical difficulties.

  4. Attention and Visuospatial Working Memory Share the Same Processing Resources

    Directory of Open Access Journals (Sweden)

    Jing eFeng

    2012-04-01

    Full Text Available Attention and visuospatial working memory (VWM share very similar characteristics; both have the same upper bound of about four items in capacity and they recruit overlapping brain regions. We examined whether both attention and visuospatial working memory share the same processing resources using a novel dual-task-costs approach based on a load-varying dual-task technique. With sufficiently large loads on attention and VWM, considerable interference between the two processes was observed. A further load increase on either process produced reciprocal increases in interference on both processes, indicating that attention and VWM share common resources. More critically, comparison among four experiments on the reciprocal interference effects, as measured by the dual-task costs, demonstrates no significant contribution from additional processing other than the shared processes. These results support the notion that attention and VWM share the same processing resources.

  5. Enhancing visuospatial processing skills in children

    NARCIS (Netherlands)

    Chabani, Elaheh (Ellahe)

    2014-01-01

    Growing evidence highlights the importance of visual-spatial processing skills (VSPS) but teaching and training of these skills at early age in schools remain understudied. To this end, we have developed a computerized application called TangSolver that aim to move one step toward assessment and tra

  6. Spatial and numerical processing in children with high and low visuospatial abilities.

    Science.gov (United States)

    Crollen, Virginie; Noël, Marie-Pascale

    2015-04-01

    In the literature on numerical cognition, a strong association between numbers and space has been repeatedly demonstrated. However, only a few recent studies have been devoted to examine the consequences of low visuospatial abilities on calculation processing. In this study, we wanted to investigate whether visuospatial weakness may affect pure spatial processing as well as basic numerical reasoning. To do so, the performances of children with high and low visuospatial abilities were directly compared on different spatial tasks (the line bisection and Simon tasks) and numerical tasks (the number bisection, number-to-position, and numerical comparison tasks). Children from the low visuospatial group presented the classic Simon and SNARC (spatial numerical association of response codes) effects but showed larger deviation errors as compared with the high visuospatial group. Our results, therefore, demonstrated that low visuospatial abilities did not change the nature of the mental number line but rather led to a decrease in its accuracy.

  7. Neural correlates of language and non-language visuospatial processing in adolescents with reading disability.

    Science.gov (United States)

    Diehl, Joshua John; Frost, Stephen J; Sherman, Gordon; Mencl, W Einar; Kurian, Anish; Molfese, Peter; Landi, Nicole; Preston, Jonathan; Soldan, Anja; Fulbright, Robert K; Rueckl, Jay G; Seidenberg, Mark S; Hoeft, Fumiko; Pugh, Kenneth R

    2014-11-01

    Despite anecdotal evidence of relative visuospatial processing strengths in individuals with reading disability (RD), only a few studies have assessed the presence or the extent of these putative strengths. The current study examined the cognitive and neural bases of visuospatial processing abilities in adolescents with RD relative to typically developing (TD) peers. Using both cognitive tasks and functional magnetic resonance imaging (fMRI) we contrasted printed word recognition with non-language visuospatial processing tasks. Behaviorally, lower reading skill was related to a visuospatial processing advantage (shorter latencies and equivalent accuracy) on a geometric figure processing task, similar to findings shown in two published studies. FMRI analyses revealed key group by task interactions in patterns of cortical and subcortical activation, particularly in frontostriatal networks, and in the distributions of right and left hemisphere activation on the two tasks. The results are discussed in terms of a possible neural tradeoff in visuospatial processing in RD.

  8. Visuo-spatial processing in a dynamic and a static working memory paradigm in schizophrenia

    DEFF Research Database (Denmark)

    Cocchi, Luca; Schenk, Françoise; Volken, Henri;

    2007-01-01

    Recent findings suggest that the visuo-spatial sketchpad (VSSP) may be divided into two sub-components processing dynamic or static visual information. This model may be useful to elucidate the confusion of data concerning the functioning of the VSSP in schizophrenia. The present study examined...... that visuo-spatial working memory can simply be dissociated into visual and spatial sub-components....

  9. Sex Differences in Cerebral Laterality of Language and Visuospatial Processing

    Science.gov (United States)

    Clements, A. M.; Rimrodt, S. L.; Abel, J. R.; Blankner, J. G.; Mostofsky, S. H.; Pekar, J. J.; Denckla, M. B.; Cutting, L. E.

    2006-01-01

    Sex differences on language and visuospatial tasks are of great interest, with differences in hemispheric laterality hypothesized to exist between males and females. Some functional imaging studies examining sex differences have shown that males are more left lateralized on language tasks and females are more right lateralized on visuospatial…

  10. White matter and visuospatial processing in autism: a constrained spherical deconvolution tractography study.

    Science.gov (United States)

    McGrath, Jane; Johnson, Katherine; O'Hanlon, Erik; Garavan, Hugh; Gallagher, Louise; Leemans, Alexander

    2013-10-01

    Autism spectrum disorders (ASDs) are associated with a marked disturbance of neural functional connectivity, which may arise from disrupted organization of white matter. The aim of this study was to use constrained spherical deconvolution (CSD)-based tractography to isolate and characterize major intrahemispheric white matter tracts that are important in visuospatial processing. CSD-based tractography avoids a number of critical confounds that are associated with diffusion tensor tractography, and to our knowledge, this is the first time that this advanced diffusion tractography method has been used in autism research. Twenty-five participants with ASD and aged 25, intelligence quotient-matched controls completed a high angular resolution diffusion imaging scan. The inferior fronto-occipital fasciculus (IFOF) and arcuate fasciculus were isolated using CSD-based tractography. Quantitative diffusion measures of white matter microstructural organization were compared between groups and associated with visuospatial processing performance. Significant alteration of white matter organization was present in the right IFOF in individuals with ASD. In addition, poorer visuospatial processing was associated in individuals with ASD with disrupted white matter in the right IFOF. Using a novel, advanced tractography method to isolate major intrahemispheric white matter tracts in autism, this research has demonstrated that there are significant alterations in the microstructural organization of white matter in the right IFOF in ASD. This alteration was associated with poorer visuospatial processing performance in the ASD group. This study provides an insight into structural brain abnormalities that may influence atypical visuospatial processing in autism.

  11. Contribution of underlying processes to improved visuospatial working memory associated with physical activity

    Directory of Open Access Journals (Sweden)

    Qingchun Ji

    2017-06-01

    Full Text Available Background Working memory is critical for various cognitive processes and can be separated into two stages: short-term memory storage and manipulation processing. Although previous studies have demonstrated that increased physical activity (PA improves working memory and that males outperform females on visuospatial working memory tasks, few studies have determined the contribution of the two underlying stages to the visuospatial working memory improvement associated with PA. Thus, the aims of the present study were to verify the relationship between physical activity and visuospatial working memory, determine whether one or both stages were affected by PA, and investigate any sex differences. Methods A total of 56 undergraduate students were recruited for this study. Their scores on the International Physical Activity Questionnaire (IPAQ were used to separate them into either a lower PA (n = 26; IPAQ score ≤3,000 metabolic equivalent [MET]-min/week or higher PA (n = 30; IPAQ score >3,000 MET-min/week group. Participants were required to complete three tasks: a visuospatial working memory task, a task that examines the short-term memory storage stage, and a mental rotation task that examines the active manipulation stage. Results Participants in the higher PA group maintained similar accuracy but displayed significantly faster reaction times (RT than those in the lower PA group on the visuospatial working memory and manipulation tasks. By contrast, no difference was observed between groups on the short-term memory storage task. In addition, no effects of sex were detected. Discussion Our results confirm that PA was positively to visuospatial working memory and that this positive relationship was associated with more rapid cognitive processing during the manipulation stage, with little or no relationship between PA and the memory storage stage of visuospatial working memory.

  12. Patterns of frontoparietal activation as a marker for unsuccessful visuospatial processing in healthy aging.

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    Drag, Lauren L; Light, Sharee N; Langenecker, Scott A; Hazlett, Kathleen E; Wilde, Elisabeth A; Welsh, Robert; Steinberg, Brett A; Bieliauskas, Linas A

    2016-09-01

    Visuospatial abilities are sensitive to age-related decline, although the neural basis for this decline (and its everyday behavioral correlates) is as yet poorly understood. fMRI was employed to examine age-related differences in patterns of functional activation that underlie changes in visuospatial processing. All participants completed a brief neuropsychological battery and also a figure ground task (FGT) assessing visuospatial processing while fMRI was recorded. Participants included 16 healthy older adults (OA; aged 69-82 years) and 16 healthy younger adults (YA; aged 20-35 years). We examined age-related differences in behavioral performance on the FGT in relation to patterns of fMRI activation. OA demonstrated reduced performance on the FGT task and showed increased activation of supramarginal parietal cortex as well as increased activation of frontal and temporal regions compared to their younger counterparts. Performance on the FGT related to increased supramarginal gyrus activity and increased medial prefrontal activity in OAs, but not YAs. Our results are consistent with an anterior-posterior compensation model. Successful FGT performance requires the perception and integration of multiple stimuli and thus it is plausible that healthy aging may be accompanied by changes in visuospatial processing that mimic a subtle form of dorsal simultanagnosia. Overall, decreased visuospatial processing in OA relates to an altered frontoparietal neurobiological signature that may contribute to the general phenomenon of increasingly fragmented execution of behavior associated with normal aging.

  13. Global Processing Training to Improve Visuospatial Memory Deficits after Right-Brain Stroke

    Science.gov (United States)

    Chen, Peii; Hartman, Ashley J.; Priscilla Galarza, C.; DeLuca, John

    2012-01-01

    Visuospatial stimuli are normally perceived from the global structure to local details. A right-brain stroke often disrupts this perceptual organization, resulting in piecemeal encoding and thus poor visuospatial memory. Using a randomized controlled design, the present study examined whether promoting the global-to-local encoding improves retrieval accuracy in right-brain-damaged stroke survivors with visuospatial memory deficits. Eleven participants received a single session of the Global Processing Training (global-to-local encoding) or the Rote Repetition Training (no encoding strategy) to learn the Rey–Osterrieth Complex Figure. The result demonstrated that the Global Processing Training significantly improved visuospatial memory deficits after a right-brain stroke. On the other hand, rote practice without a step-by-step guidance limited the degree of memory improvement. The treatment effect was observed both immediately after the training procedure and 24 h post-training. Overall, the present findings are consistent with the long-standing principle in cognitive rehabilitation that an effective treatment is based on specific training aimed at improving specific neurocognitive deficits. Importantly, visuospatial memory deficits after a right-brain stroke may improve with treatments that promote global processing at encoding. PMID:23070314

  14. Stronger activation and deactivation in archery experts for differential cognitive strategy in visuospatial working memory processing.

    Science.gov (United States)

    Seo, Jeehye; Kim, Yang-Tae; Song, Hui-Jin; Lee, Hui Joong; Lee, Jongmin; Jung, Tae-Du; Lee, Gunyoung; Kwon, Eunjin; Kim, Jin Gu; Chang, Yongmin

    2012-04-01

    It is well known that elite athletes have higher performance in perception, planning, and execution in sports activities relative to novices. It remains controversial, however, whether any differences in basic cognitive functions between experts and novices exist. Furthermore, few studies have directly used functional magnetic resonance imaging (fMRI) to investigate neural activation and deactivation differences between experts and novices while performing visuospatial working memory (WM) tasks. Therefore, the purpose of this study was to examine possible differences in neural activation and deactivation associated with working memory components in processing visuospatial information between archery experts and novices. To this end, we employed a judgment of line orientation (JLO) task, which has a strong WM component. With regard to brain activation, archery experts displayed higher activation in cortical areas associated with visuospatial attention and working memory, including the middle frontal cortex, supplemental motor area, and dorsolateral prefrontal cortex than that of the novices during the performance of the JLO task. With regard to brain deactivation, archery experts exhibited stronger task-related deactivation in cortical areas, such as the paracentral cortex/precuneus and the anterior and posterior cingulate cortex related to the default network, than that of the novices. These results suggest that the archery experts have a strategy that demands greater use of neural correlates associated with visuospatial working memory and attention in addition to greater use of DMN in visuospatial working memory task not directly tied to their domain of expertise.

  15. Visuospatial Processing in Children with Autism: No Evidence for (Training-Resistant) Abnormalities

    Science.gov (United States)

    Chabani, Ellahe; Hommel, Bernhard

    2014-01-01

    Individuals with autism spectrum disorders (ASDs) have been assumed to show evidence of abnormal visuospatial processing, which has been attributed to a failure to integrate local features into coherent global Gestalts and/or to a bias towards local processing. As the available data are based on baseline performance only, which does not provide…

  16. The Visuospatial Dimension of Writing

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    Olive, Thierry; Passerault, Jean-Michel

    2012-01-01

    The authors suggest that writing should be conceived of not only as a verbal activity but also as a visuospatial activity, in which writers process and construct visuospatial mental representations. After briefly describing research on visuospatial cognition, they look at how cognitive researchers have investigated the visuospatial dimension of…

  17. Differential recruitment of brain networks during visuospatial and color processing: Evidence from ERP microstates.

    Science.gov (United States)

    Antonova, I; Bänninger, A; Dierks, T; Griskova-Bulanova, I; Koenig, T; Kohler, A

    2015-10-01

    Recent functional magnetic resonance imaging (fMRI) studies consistently revealed contributions of fronto-parietal and related networks to the execution of a visuospatial judgment task, the so-called "Clock Task". However, due to the low temporal resolution of fMRI, the exact cortical dynamics and timing of processing during task performance could not be resolved until now. In order to clarify the detailed cortical activity and temporal dynamics, 14 healthy subjects performed an established version of the "Clock Task", which comprises a visuospatial task (angle discrimination) and a control task (color discrimination) with the same stimulus material, in an electroencephalography (EEG) experiment. Based on the time-resolved analysis of network activations (microstate analysis), differences in timing between the angle compared to the color discrimination task were found after sensory processing in a time window starting around 200 ms. Significant differences between the two tasks were observed in an analysis window from 192 ms to 776 ms. We divided this window in two parts: an early phase - from 192 ms to ∼440 ms, and a late phase - from ∼440 ms to 776 ms. For both tasks, the order of network activations and the types of networks were the same, but, in each phase, activations for the two conditions were dominated by differing network states with divergent temporal dynamics. Our results provide an important basis for the assessment of deviations in processing dynamics during visuospatial tasks in clinical populations.

  18. Multivariate Longitudinal Modeling of Cognitive Aging: Associations Among Change and Variation in Processing Speed and Visuospatial Ability.

    Science.gov (United States)

    Robitaille, Annie; Muniz, Graciela; Piccinin, Andrea M; Johansson, Boo; Hofer, Scott M

    2012-01-01

    We illustrate the use of the parallel latent growth curve model using data from OCTO-Twin. We found a significant intercept-intercept and slope-slope association between processing speed and visuospatial ability. Within-person correlations among the occasion-specific residuals were significant, suggesting that the occasion-specific fluctuations around individual's trajectories, after controlling for intraindividual change, are related between both outcomes. Random and fixed effects for visuospatial ability are reduced when we include structural parameters (directional growth curve model) providing information about changes in visuospatial abilities after controlling for processing speed. We recommend this model to researchers interested in the analysis of multivariate longitudinal change, as it permits decomposition and directly interpretable estimates of association among initial levels, rates of change, and occasion-specific variation.

  19. The role of short-term memory and visuo-spatial skills in numerical magnitude processing: Evidence from Turner syndrome.

    Science.gov (United States)

    Attout, Lucie; Noël, Marie-Pascale; Nassogne, Marie-Cécile; Rousselle, Laurence

    2017-01-01

    Most studies on magnitude representation have focused on the visual modality with no possibility of disentangling the influence of visuo-spatial skills and short-term memory (STM) abilities on quantification processes. This study examines this issue in patients with Turner syndrome (TS), a genetic condition characterized by a specific cognitive profile frequently associating poor mathematical achievement, low spatial skills and reduced STM abilities. In order to identify the influence of visuo-spatial and STM processing on numerical magnitude abilities, twenty female participants with TS and twenty control female participants matched for verbal IQ and education level were administered a series of magnitude comparison tasks. The tasks differed on the nature of the magnitude to be processed (continuous, discrete and symbolic magnitude), on visuo-spatial processing requirement (no/high) and on STM demands (low in simultaneous presentation vs. high in sequential presentation). Our results showed a lower acuity when participants with TS compared the numerical magnitudes of stimuli presented sequentially (low visuo-spatial processing and high STM load: Dot sequence and Sound sequence) while no difference was observed in the numerical comparison of sets presented simultaneously. In addition, the group difference in sequential tasks disappeared when controlling for STM abilities. Finally, both groups demonstrated similar performance when comparing continuous or symbolic magnitude stimuli and they exhibited comparable subitizing abilities. These results highlight the importance of STM abilities in extracting numerosity through a sequential presentation and underline the importance of considering the impact of format presentation on magnitude judgments.

  20. The role of short-term memory and visuo-spatial skills in numerical magnitude processing: Evidence from Turner syndrome

    Science.gov (United States)

    Noël, Marie-Pascale; Nassogne, Marie-Cécile; Rousselle, Laurence

    2017-01-01

    Most studies on magnitude representation have focused on the visual modality with no possibility of disentangling the influence of visuo-spatial skills and short-term memory (STM) abilities on quantification processes. This study examines this issue in patients with Turner syndrome (TS), a genetic condition characterized by a specific cognitive profile frequently associating poor mathematical achievement, low spatial skills and reduced STM abilities. In order to identify the influence of visuo-spatial and STM processing on numerical magnitude abilities, twenty female participants with TS and twenty control female participants matched for verbal IQ and education level were administered a series of magnitude comparison tasks. The tasks differed on the nature of the magnitude to be processed (continuous, discrete and symbolic magnitude), on visuo-spatial processing requirement (no/high) and on STM demands (low in simultaneous presentation vs. high in sequential presentation). Our results showed a lower acuity when participants with TS compared the numerical magnitudes of stimuli presented sequentially (low visuo-spatial processing and high STM load: Dot sequence and Sound sequence) while no difference was observed in the numerical comparison of sets presented simultaneously. In addition, the group difference in sequential tasks disappeared when controlling for STM abilities. Finally, both groups demonstrated similar performance when comparing continuous or symbolic magnitude stimuli and they exhibited comparable subitizing abilities. These results highlight the importance of STM abilities in extracting numerosity through a sequential presentation and underline the importance of considering the impact of format presentation on magnitude judgments. PMID:28222116

  1. Functional anatomy of top-down visuospatial processing in the human brain : evidence from rTMS

    NARCIS (Netherlands)

    Aleman, A; Schutter, DJLG; Ramsey, NF; van Honk, J; Kessels, RPC; Hoogduin, JM; Postma, A; Kahn, RS; de Haan, EHF

    2002-01-01

    The hypothesis was tested that visuospatial mental imagery relies on processing in the posterior parietal lobe. Using repetitive transcranial magnetic stimulation (rTMS) in a cross-over, sham-controlled design, we compared involvement of right posterior parietal cortex with primary visual cortex. Su

  2. The Role of Working Memory in Spatial Text Processing: What Benefit of Imagery Strategy and Visuospatial Abilities?

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    Gyselinck, Valerie; Meneghetti, Chiara; De Beni, Rossana; Pazzaglia, Francesca

    2009-01-01

    This study investigated the construction of a spatial model in relation to working memory (WM) and visuospatial abilities. Participants were trained to use either imagery or verbal strategies to process route spatial texts. Results obtained on a free recall task, a verification test and a graphic representation task showed the beneficial effect of…

  3. Functional anatomy of top-down visuospatial processing in the human brain: evidence from rTMS

    NARCIS (Netherlands)

    Aleman, A.; Schutter, D.J.L.G.; Ramsey, N.F.; Honk, E.J. van; Kessels, R.P.C.; Hoogduin, J.M.; Postma, A.; Kahn, R.S.; Haan, E.H.F. de

    2002-01-01

    The hypothesis was tested that visuospatial mental imagery relies on processing in the posterior parietal lobe. Using repetitive transcranial magnetic stimulation (rTMS) in a cross-over, sham-controlled design, we compared involvement of right posterior parietal cortex with primary visual cortex.

  4. Functional anatomy of top-down visuospatial processing in the human brain : evidence from rTMS

    NARCIS (Netherlands)

    Aleman, A; Schutter, DJLG; Ramsey, NF; van Honk, J; Kessels, RPC; Hoogduin, JM; Postma, A; Kahn, RS; de Haan, EHF

    The hypothesis was tested that visuospatial mental imagery relies on processing in the posterior parietal lobe. Using repetitive transcranial magnetic stimulation (rTMS) in a cross-over, sham-controlled design, we compared involvement of right posterior parietal cortex with primary visual cortex.

  5. Developmental trajectories of hierarchical visuo-spatial processing in fragile X syndrome and ASD: Within- and cross-syndrome variability.

    Science.gov (United States)

    Ballantyne, Carrie J; Núñez, María

    2016-01-01

    Despite the advances in understanding visuo-spatial processing in developmental disorders such as ASD and fragile X syndrome (FXS), less is known about the profile of those with a comorbid diagnosis, or the role of within-disorder disparities between individuals across the ASD spectrum. Using a developmental trajectory approach, we tested 5 groups of children: Typically developing, FXS, FXS+ASD, ASD individuals who had low-moderate symptoms (HFA) and ASD individuals who had severe symptoms (LFA). Symptoms of ASD were assessed using the Childhood Autism Rating Scale: CARS and hierarchical visuo-spatial processing was assessed using the Navon task. Crucially, results differed between HFA and LFA participants. Furthermore, the pattern of results differed between those who had a diagnosis of FXS only and FXS+ASD. Poorer performance within the FXS groups and the group who are low functioning on the ASD spectrum indicated a delayed developmental rate compared to typical controls. This study showed that diagnosis and severity of symptoms are indicative of differences in visuo-spatial processing styles. It is important that heterogeneity within FXS and ASD populations are considered in subsequent studies and look beyond diagnostic group differences. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Impact of load-related neural processes on feature binding in visuospatial working memory.

    Directory of Open Access Journals (Sweden)

    Nicole A Kochan

    Full Text Available BACKGROUND: The capacity of visual working memory (WM is substantially limited and only a fraction of what we see is maintained as a temporary trace. The process of binding visual features has been proposed as an adaptive means of minimising information demands on WM. However the neural mechanisms underlying this process, and its modulation by task and load effects, are not well understood. OBJECTIVE: To investigate the neural correlates of feature binding and its modulation by WM load during the sequential phases of encoding, maintenance and retrieval. METHODS AND FINDINGS: 18 young healthy participants performed a visuospatial WM task with independent factors of load and feature conjunction (object identity and position in an event-related functional MRI study. During stimulus encoding, load-invariant conjunction-related activity was observed in left prefrontal cortex and left hippocampus. During maintenance, greater activity for task demands of feature conjunction versus single features, and for increased load was observed in left-sided regions of the superior occipital cortex, precuneus and superior frontal cortex. Where these effects were expressed in overlapping cortical regions, their combined effect was additive. During retrieval, however, an interaction of load and feature conjunction was observed. This modulation of feature conjunction activity under increased load was expressed through greater deactivation in medial structures identified as part of the default mode network. CONCLUSIONS AND SIGNIFICANCE: The relationship between memory load and feature binding qualitatively differed through each phase of the WM task. Of particular interest was the interaction of these factors observed within regions of the default mode network during retrieval which we interpret as suggesting that at low loads, binding processes may be 'automatic' but at higher loads it becomes a resource-intensive process leading to disengagement of activity in this

  7. Visuo-Spatial Processing in Autism--Testing the Predictions of Extreme Male Brain Theory

    Science.gov (United States)

    Falter, Christine M.; Plaisted, Kate C.; Davis, Greg

    2008-01-01

    It has been hypothesised that autism is an extreme version of the male brain, caused by high levels of prenatal testosterone (Baron-Cohen 1999). To test this proposal, associations were assessed between three visuo-spatial tasks and prenatal testosterone, indexed in second-to-fourth digit length ratios (2D:4D). The study included children with…

  8. Visuospatial information processing load and the ratio between parietal cue and target P3 amplitudes in the Attentional Network Test.

    Science.gov (United States)

    Abramov, Dimitri M; Pontes, Monique; Pontes, Adailton T; Mourao-Junior, Carlos A; Vieira, Juliana; Quero Cunha, Carla; Tamborino, Tiago; Galhanone, Paulo R; deAzevedo, Leonardo C; Lazarev, Vladimir V

    2017-04-24

    In ERP studies of cognitive processes during attentional tasks, the cue signals containing information about the target can increase the amplitude of the parietal cue P3 in relation to the 'neutral' temporal cue, and reduce the subsequent target P3 when this information is valid, i.e. corresponds to the target's attributes. The present study compared the cue-to-target P3 ratios in neutral and visuospatial cueing, in order to estimate the contribution of valid visuospatial information from the cue to target stages of the task performance, in terms of cognitive load. The P3 characteristics were also correlated with the results of individuals' performance of the visuospatial tasks, in order to estimate the relationship of the observed ERP with spatial reasoning. In 20 typically developing boys, aged 10-13 years (11.3±0.86), the intelligence quotient (I.Q.) was estimated by the Block Design and Vocabulary subtests from the WISC-III. The subjects performed the Attentional Network Test (ANT) accompanied by EEG recording. The cued two-choice task had three equiprobable cue conditions: No cue, with no information about the target; Neutral (temporal) cue, with an asterisk in the center of the visual field, predicting the target onset; and Spatial cues, with an asterisk in the upper or lower hemifield, predicting the onset and corresponding location of the target. The ERPs were estimated for the mid-frontal (Fz) and mid-parietal (Pz) scalp derivations. In the Pz, the Neutral cue P3 had a lower amplitude than the Spatial cue P3; whereas for the target ERPs, the P3 of the Neutral cue condition was larger than that of the Spatial cue condition. However, the sums of the magnitudes of the cue and target P3 were equal in the spatial and neutral cueing, probably indicating that in both cases the equivalent information processing load is included in either the cue or the target reaction, respectively. Meantime, in the Fz, the analog ERP components for both the cue and target

  9. Hippocampus activation related to 'real-time' processing of visuospatial change

    NARCIS (Netherlands)

    Beudel, M.; Leenders, K. L.; de Jong, B. M.

    2016-01-01

    The delay associated with cerebral processing time implies a lack of real-time representation of changes in the observed environment. To bridge this gap for motor actions in a dynamical environment, the brain uses predictions of the most plausible future reality based on previously provided informat

  10. HIPPOCAMPUS ACTIVATION RELATED TO 'REAL-TIME' PROCESSING OF VISUOSPATIAL CHANGE

    NARCIS (Netherlands)

    Beudel, M; Leenders, K L; de Jong, B M

    2016-01-01

    The delay associated with cerebral processing time implies a lack of real-time representation of changes in the observed environment. To bridge this gap for motor actions in a dynamical environment, the brain uses predictions of the most plausible future reality based on previously provided informat

  11. Numerical analysis of tunnel reinforcing influences on failure process of surrounding rock under explosive stress waves

    Institute of Scientific and Technical Information of China (English)

    ZUO Yu-jun; TANG Chun-an; ZHU Wan-cheng; LI Di-yuan; LI Shu-cai

    2008-01-01

    Based on mesoscopic damage mechanics, numerical code RFPA2D (dynamic edition) was developed to analyze the influence of tunnel reinforcing on failure process of surrounding rock under explosive stress waves. The results show that the propagation phenomenon of stress wave in the surrounding rock of tunnel and the failure process of surrounding rock under explosive stress waves are reproduced realistically by using numerical code RFPAED; from the failure process of surrounding rock,the place at which surrounding rock fractures is transferred because of tunnel reinforcing, and the rockfall and collapse caused by failure of surrounding rock are restrained by tunnel reinforcing; furthermore, the absolute values of peak values of major principal stress, and the minimal principal stress and shear stress at center point of tunnel roof are reduced because of tunnel reinforcing, and the displacement at center point of tunnel roof is reduced as well, consequently the stability of tunnel increases.

  12. Hemispheric preference in visuospatial processing: a complementary approach with fMRI and lesion studies.

    Science.gov (United States)

    Ng, V W; Eslinger, P J; Williams, S C; Brammer, M J; Bullmore, E T; Andrew, C M; Suckling, J; Morris, R G; Benton, A L

    2000-06-01

    Historically, the left cerebral hemisphere has been considered specialized for language, whereas the right cerebral hemisphere is aligned with spatial processes. However, studies have called into question adherence to this model and suggested that both hemispheres participate in language and spatial cognition. Using functional Magnetic Resonance Imaging (fMRI) and human brain lesion studies, we determined whether these complementary techniques could clarify issues of hemispheric dominance. Using a modified Benton Judgement of Line Orientation (JLO) test, considered a relatively pure spatial processing task, we found robust and significant (p < 0.0005) bilateral superior parietal lobe activation on fMRI in ten right-handed male adult volunteers. This was corroborated by lesion data in a cohort of 17 patients who showed significant JLO impairments after either right or left parietal lobe damage, with right parietal damage associated with somewhat more severe deficit. Detailed wavelet analysis of the fMRI time-series did, however, reveal a more dominant role of the right parietal lobe in "kick-starting" the task. To our knowledge, this is a novel way of using fMRI to address functional hemispheric differences in a cognitive task that is known to have bilateral representation.

  13. Haptic identification of raised-line drawings: high visuospatial imagers outperform low visuospatial imagers.

    Science.gov (United States)

    Lebaz, Samuel; Jouffrais, Christophe; Picard, Delphine

    2012-09-01

    It has been assumed (Lederman et al. 1990, Perception & psychophysics) that a visual imagery process is involved in the haptic identification of raised-line drawings of common objects. The finding of significant correlations between visual imagery ability and performance on picture-naming tasks was taken as experimental evidence in support of this assumption. However, visual imagery measures came from self-report procedures, which can be unreliable. The present study therefore used an objective measure of visuospatial imagery abilities in sighted participants and compared three groups of high, medium and low visuospatial imagers on their accuracy and response times in identifying raised-line drawings by touch. Results revealed between-group differences on accuracy, with high visuospatial imagers outperforming low visuospatial imagers, but not on response times. These findings lend support to the view that visuospatial imagery plays a role in the identification of raised-line drawings by sighted adults.

  14. Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing.

    Science.gov (United States)

    Vannini, Patrizia; Lehmann, Christoph; Dierks, Thomas; Jann, Kay; Viitanen, Matti; Wahlund, Lars-Olof; Almkvist, Ove

    2008-09-01

    Alzheimer's disease (AD) is characterized by disturbances of visuospatial cognition. Given that these impairments are closely related to metabolic and neuropathological changes, our study aimed to investigate the functional competency of brain regions in the visuospatial networks responsible for early clinical symptoms in AD using event-related functional magnetic resonance imaging (fMRI). Participants (13AD patients with mild symptoms and 13 age- and education-matched controls) performed an angle discrimination task with varying task demand. Using a novel approach that modeled the dependency of the blood oxygenation level-dependent (BOLD) signal on the subject's reaction time allowed us to investigate task demand-dependent signal changes between the groups. Both groups demonstrated overlapping neural networks engaged in angle discrimination, including the parieto-occipital and frontal regions. In several network regions, AD patients showed a significantly weaker and sometimes no BOLD signal due to increased task demand compared with controls, demonstrating failure to modulate the neural response to increased task demand. A general task demand-independent increase of activation in AD patients compared with controls was found in right middle temporal gyrus. This latter finding may indicate an attempt to compensate for dysfunctional areas in the dorsal visual pathway. These results confirm deficits in visuospatial abilities, which occur early in AD, and offer new insights into the neural mechanisms underlying this impairment.

  15. Simultaneous recording of EEG and fNIRS during visuo-spatial and facial expression processing in a dual task paradigm.

    Science.gov (United States)

    Herrmann, Martin J; Neueder, Dorothea; Troeller, Anna K; Schulz, Stefan M

    2016-11-01

    Emotional processing is probably the most crucial tool for orienting oneself in our everyday social life and has been considered to be highly automatic for a long time. Dual task (DT) research shows that information competing for working memory resources impairs the identification of emotional facial expressions. Effects of cognitive load in DT paradigms have been confirmed in numerous neuroimaging studies. However, interference occurring during a DT comprised of decoding emotional facial expressions and a visuo-spatial working memory task has yet to be visualized. To investigate the DT interference effect on brain areas associated not only with working memory, but also emotional and visuo-spatial processing, we recorded brain activation within the prefrontal cortex and parietal-occipital sensory areas using functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) simultaneously. Our study consisted of N = 36 participants (27 female) performing the following tasks: a) Corsi blocks, b) identification of emotional facial expressions or c) DT comprising of tasks a) and b). We predicted higher activation of the prefrontal cortex during DT and corresponding reduced P100 and P300 amplitudes. As expected, fNIRS measurements revealed significantly higher neuronal activation within the prefrontal cortex in the DT condition. When comparing DT to the single tasks, the P100 amplitude was reduced, but the P300 amplitude did not show the expected reduction. Our findings underline that at least some aspects of emotional processing are not entirely automatic, but depend on prefrontal control and are therefore affected by cognitive load, in particular visuo-spatial working memory resources.

  16. How skill expertise shapes the brain functional architecture: an fMRI study of visuo-spatial and motor processing in professional racing-car and naive drivers.

    Directory of Open Access Journals (Sweden)

    Giulio Bernardi

    Full Text Available The present study was designed to investigate the brain functional architecture that subserves visuo-spatial and motor processing in highly skilled individuals. By using functional magnetic resonance imaging (fMRI, we measured brain activity while eleven Formula racing-car drivers and eleven 'naïve' volunteers performed a motor reaction and a visuo-spatial task. Tasks were set at a relatively low level of difficulty such to ensure a similar performance in the two groups and thus avoid any potential confounding effects on brain activity due to discrepancies in task execution. The brain functional organization was analyzed in terms of regional brain response, inter-regional interactions and blood oxygen level dependent (BOLD signal variability. While performance levels were equal in the two groups, as compared to naïve drivers, professional drivers showed a smaller volume recruitment of task-related regions, stronger connections among task-related areas, and an increased information integration as reflected by a higher signal temporal variability. In conclusion, our results demonstrate that, as compared to naïve subjects, the brain functional architecture sustaining visuo-motor processing in professional racing-car drivers, trained to perform at the highest levels under extremely demanding conditions, undergoes both 'quantitative' and 'qualitative' modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks. These results provide novel evidence in favor of an increased 'neural efficiency' in the brain of highly skilled individuals.

  17. Visuospatial and verbal working memory load: effects on visuospatial vigilance.

    Science.gov (United States)

    Helton, William S; Russell, Paul N

    2013-02-01

    In this study, we examined the impact of concurrent verbal and visuospatial working memory demands on performance of a visuospatial successive target detection task. Three hundred and four participants performed a visuospatial vigilance task while simultaneously performing either a spatial or verbal working memory task that either required a memory load during the vigil or did not require a memory load during the vigil. Perceptual sensitivity A' to vigilance target stimuli was reduced by concurrent memory load, both verbal and visuospatial. The decline in perceptual sensitivity to vigilance targets, the vigilance decrement, was steeper for a visuospatial memory task than a verbal memory task, regardless of concurrent memory load. Memory performance after vigilance detection trials was much lower for visuospatial than verbal items, even though memory performance before vigilance detection trials was higher for visuospatial than verbal items. Together, this indicates increased interference when a visuospatial vigilance task is paired with a visuospatial memory task, than when paired with a verbal memory task. Overall, the visuospatial and verbal working memory loads both impacted vigilance target detection, suggesting utilization of common executive resources. There may, however, be domain specific interference, and this may be exacerbated for two visuospatial tasks.

  18. Inflammation surrounding the vertebral spinous processes as spondylarthritis in Behçet's disease.

    Science.gov (United States)

    Yamashita, Hiroyuki; Kubota, Kazuo; Takahashi, Yuko; Kaneko, Hiroshi; Kano, Toshikazu; Mimori, Akio

    2013-07-01

    Here, we present two Behçet's disease (BD) patients with an uncommon complication: inflammation surrounding the spinous processes revealed by positron emission tomography/computed tomography (PET/CT). Both patients were treated successfully with 20 mg of prednisolone daily. Whether BD should be considered a form of spondylarthritis remains an open question. However, inflammation around the spinous processes should be regarded as a possible uncommon finding of seronegative spondyloarthropathy (SpA) in BD patients.

  19. Brain network dynamics underlying visuospatial judgment: an FMRI connectivity study.

    Science.gov (United States)

    de Graaf, Tom A; Roebroeck, Alard; Goebel, Rainer; Sack, Alexander T

    2010-09-01

    Previous functional imaging research has consistently indicated involvement of bilateral fronto-parietal networks during the execution of visuospatial tasks. Studies with TMS have suggested that the right hemispheric network, but not the left, is functionally relevant for visuospatial judgments. However, very little is still known about the interactions within these fronto-parietal networks underlying visuospatial processing. In the current study, we investigated task modulation of functional connectivity (instantaneous correlations of regional time courses), and task-specific effective connectivity (direction of influences), within the right fronto-parietal network activated during visuospatial judgments. Ten healthy volunteers performed a behaviorally controlled visuospatial judgment task (ANGLE) or a control task (COLOR) in an fMRI experiment. Visuospatial task-specific activations were found in posterior parietal cortex (PPC) and middle/inferior frontal gyrus (MFG). Functional connectivity within this network was task-modulated, with significantly higher connectivity between PPC and MFG during ANGLE than during COLOR. Effective connectivity analysis for directed influence revealed that visuospatial task-specific projections within this network were predominantly in a frontal-to-parietal direction. Moreover, ANGLE-specific influences from thalamic nuclei to PPC were identified. Exploratory effective connectivity analysis revealed that closely neighboring clusters, within visuospatial regions, were differentially involved in the network. These neighboring clusters had opposite effective connectivity patterns to other nodes of the fronto-parietal network. Our data thus reveal that visuospatial judgments are supported by massive fronto-parietal backprojections, thalamo-parietal influence, and multiple stages, or loops, of information flow within the visuospatial network. We speculate on possible functional contributions of the various network nodes and

  20. Simulation of coupled THM process in surrounding rock mass of nuclear waste repository in argillaceous formation

    Institute of Scientific and Technical Information of China (English)

    蒋中明; 陈永贵

    2015-01-01

    To investigate and analyze the thermo-hydro-mechanical (THM) coupling phenomena of a surrounding rock mass in an argillaceous formation, a nuclear waste disposal concept in drifts was represented physically in an in-situ test way. A transversely isotropic model was employed to reproduce the whole test process numerically. Parameters of the rock mass were determined by laboratory and in-situ experiments. Based on the numerical simulation results and in-situ test data, the variation processes of pore water pressure, temperature and deformation of surrounding rock were analyzed. Both the measured data and numerical results reveal that the thermal perturbation is the principal driving force which leads to the variation of pore water pressure and deformations in the surrounding rock. The temperature, pore pressure and deformation of rock mass change rapidly at each initial heating stage with a constant heating power. The temperature field near the heater borehole is relatively steady in the subsequent stages of the heating phase. However, the pore pressure and deformation fields decrease gradually with temperature remaining unchanged condition. It also shows that a transversely isotropic model can reproduce the THM coupling effects generating in the near-field of a nuclear waste repository in an argillaceous formation.

  1. Biased Visuospatial Attention in Cervical Dystonia.

    Science.gov (United States)

    Chillemi, Gaetana; Formica, Caterina; Salatino, Adriana; Calamuneri, Alessandro; Girlanda, Paolo; Morgante, Francesca; Milardi, Demetrio; Terranova, Carmen; Cacciola, Alberto; Quartarone, Angelo; Ricci, Raffaella

    2017-08-09

    There is increasing evidence of non-motor, sensory symptoms, mainly involving the spatial domain, in cervical dystonia (CD). These manifestations are likely driven by dysfunctional overactivity of the parietal cortex during the execution of a sensory task. Few studies also suggest the possibility that visuospatial attention might be specifically affected in patients with CD. Therefore, we asked whether non-motor manifestations in CD might also comprise impairment of higher level visuospatial processing. To this end, we investigated visuospatial attention in 23 CD patients and 12 matched healthy controls (for age, gender, education, and ocular dominance). The patients were identified according to the dystonia pattern type (laterocollis vs. torticollis). Overall, participants were right-handers, and the majority of them was right-eye dominant. Visuospatial attention was assessed using a line bisection task. Participants were asked to bisect horizontal lines, using their right or left hand. Participants bisected more to the left of true center when using their left hand to perform the task than when using their right hand. However, overall, torticollis patients produced a significantly greater leftward deviation than controls. These data are consistent with preliminary findings suggesting the presence of biased spatial attention in patients with idiopathic cervical dystonia. The presence of an attentional bias in patients with torticollis seem to indicate that alterations of attentional circuits might be implicated in the pathophysiology of this type of CD. (JINS, 2017, 23, 1-11).

  2. An Autistic Endophenotype and Testosterone Are Involved in an Atypical Decline in Selective Attention and Visuospatial Processing in Middle-Aged Women.

    Science.gov (United States)

    Ángel, Romero-Martínez; Luis, Moya-Albiol

    2015-12-15

    Mothers of offspring with autism spectrum disorders (ASD) could present mild forms of their children's cognitive characteristics, resulting from prenatal brain exposure and sensitivity to testosterone (T). Indeed, their cognition is frequently characterized by hyper-systemizing, outperforming in tests that assess cognitive domains such as selective attention, and fine motor and visuospatial skills. In the general population, all these start to decline around the mid-forties. This study aimed to characterize whether middle-aged women who are biological mothers of individuals with ASD had better performance in the aforementioned cognitive skills than mothers of normative children (in both groups n = 22; mean age = 45), using the standardized Stroop and mirror-drawing tests. We also examined the role of T in their performance in the aforementioned tests. ASD mothers outperformed controls in both tests, giving more correct answers and making fewer mistakes. In addition, they presented higher T levels, which have been associated with better cognitive performance. Cognitive decline in specific skills with aging could be delayed in these middle-aged women, corresponding to a cognitive endophenotype, T playing an important role in this process.

  3. An Autistic Endophenotype and Testosterone Are Involved in an Atypical Decline in Selective Attention and Visuospatial Processing in Middle-Aged Women

    Directory of Open Access Journals (Sweden)

    Romero-Martínez Ángel

    2015-12-01

    Full Text Available Mothers of offspring with autism spectrum disorders (ASD could present mild forms of their children’s cognitive characteristics, resulting from prenatal brain exposure and sensitivity to testosterone (T. Indeed, their cognition is frequently characterized by hyper-systemizing, outperforming in tests that assess cognitive domains such as selective attention, and fine motor and visuospatial skills. In the general population, all these start to decline around the mid-forties. This study aimed to characterize whether middle-aged women who are biological mothers of individuals with ASD had better performance in the aforementioned cognitive skills than mothers of normative children (in both groups n = 22; mean age = 45, using the standardized Stroop and mirror-drawing tests. We also examined the role of T in their performance in the aforementioned tests. ASD mothers outperformed controls in both tests, giving more correct answers and making fewer mistakes. In addition, they presented higher T levels, which have been associated with better cognitive performance. Cognitive decline in specific skills with aging could be delayed in these middle-aged women, corresponding to a cognitive endophenotype, T playing an important role in this process.

  4. Thoughts in space: the impact of environmental surround on cognitive processing.

    Science.gov (United States)

    Stevens, Jennifer A; Duffie, Vanessa; Vishton, Peter M

    2015-09-01

    The embodied cognition perspective has provided a formalization of the idea that the motor state is a characteristic of being that permeates all of human processing. We review this perspective and experimental evidence supporting its claim. It is further considered that the motor behaving human moves within various spaces, each affording different actions. To this end, it is proposed that the environmental surround is a critical variable in the embodied cognition perspective. Thoughts, inasmuch as they may be grounded in simulation of motor-behavioural responses, require time but also space. We suggest that these time-space considerations occur within a proposed concept of the potentiated state.

  5. A model of motion transparency processing with local center-surround interactions and feedback.

    Science.gov (United States)

    Raudies, Florian; Mingolla, Ennio; Neumann, Heiko

    2011-11-01

    Motion transparency occurs when multiple coherent motions are perceived in one spatial location. Imagine, for instance, looking out of the window of a bus on a bright day, where the world outside the window is passing by and movements of passengers inside the bus are reflected in the window. The overlay of both motions at the window leads to motion transparency, which is challenging to process. Noisy and ambiguous motion signals can be reduced using a competition mechanism for all encoded motions in one spatial location. Such a competition, however, leads to the suppression of multiple peak responses that encode different motions, as only the strongest response tends to survive. As a solution, we suggest a local center-surround competition for population-encoded motion directions and speeds. Similar motions are supported, and dissimilar ones are separated, by representing them as multiple activations, which occurs in the case of motion transparency. Psychophysical findings, such as motion attraction and repulsion for motion transparency displays, can be explained by this local competition. Besides this local competition mechanism, we show that feedback signals improve the processing of motion transparency. A discrimination task for transparent versus opaque motion is simulated, where motion transparency is generated by superimposing large field motion patterns of either varying size or varying coherence of motion. The model's perceptual thresholds with and without feedback are calculated. We demonstrate that initially weak peak responses can be enhanced and stabilized through modulatory feedback signals from higher stages of processing.

  6. Visuospatial deficits of dyslexic children

    OpenAIRE

    Lipowska, Małgorzata; Czaplewska, Ewa; Wysocka, Anna

    2011-01-01

    Summary Background The visuospatial deficit is recognized as typical for dyslexia only in some definitions. However problems with visuospatial orientation may manifest themselves as difficulties with letter identification or the memorizing and recalling of sign sequences, something frequently experienced by dyslexics. Material/Methods The experimental group consisted of 62 children with developmental dyslexia. The control group consisted of 67 pupils with no diagnosed deficits, matched to the...

  7. The Specific Involvement of Verbal and Visuospatial Working Memory in Hypermedia Learning

    Science.gov (United States)

    Pazzaglia, Francesca; Toso, Cristina; Cacciamani, Stefano

    2008-01-01

    Many models have hypothesized that multimedia comprehension requires the concurrent processing of verbal and visuospatial information by limited information processing systems. However, in spite of the emphasis devoted to the concurrent processing of verbal and visuospatial information, little research has so far investigated the specific role…

  8. Visuospatial Working Memory Capacity Predicts Physiological Arousal in a Narrative Task.

    Science.gov (United States)

    Smithson, Lisa; Nicoladis, Elena

    2016-06-01

    Physiological arousal that occurs during narrative production is thought to reflect emotional processing and cognitive effort (Bar-Haim et al. in Dev Psychobiol 44:238-249, 2004). The purpose of this study was to determine whether individual differences in visuospatial working memory and/or verbal working memory capacity predict physiological arousal in a narrative task. Visuospatial working memory was a significant predictor of skin conductance level (SCL); verbal working memory was not. When visuospatial working memory interference was imposed, visuospatial working memory was no longer a significant predictor of SCL. Visuospatial interference also resulted in a significant reduction in SCL. Furthermore, listener ratings of narrative quality were contingent upon the visuospatial working memory resources of the narrator. Potential implications for educators and clinical practitioners are discussed.

  9. Sex differences favoring women in verbal but not in visuospatial episodic memory.

    Science.gov (United States)

    Lewin, C; Wolgers, G; Herlitz, A

    2001-04-01

    Sex differences favoring women have been found in a number of studies of episodic memory. This study examined sex differences in verbal, nonverbal, and visuospatial episodic memory tasks. Results showed that although women performed at a higher level on a composite verbal and nonverbal episodic memory score, men performed at a higher level on a composite score of episodic memory tasks requiring visuospatial processing. Thus, men can use their superior visuospatial abilities to excel in highly visuospatial episodic memory tasks, whereas women seem to excel in episodic memory tasks in which a verbalization of the material is possible.

  10. The relationship between different exercise modes and visuospatial working memory in older adults: a cross-sectional study.

    Science.gov (United States)

    Guo, Wei; Wang, Biye; Lu, Yue; Zhu, Qin; Shi, Zhihao; Ren, Jie

    2016-01-01

    The purpose of the study was to investigate the relationship between different exercise modes and visuospatial working memory in healthy older adults. A cross-sectional design was adopted. A total of 111 healthy older adults were enrolled in the study. They were classified by the exercise-related questionnaire to be in an open-skill group, closed-skill group or sedentary group. In experiment 1, the participants performed a visuospatial working memory task. The results indicated that both closed-skill (p visuospatial short-term memory task and visuospatial mental rotation task, respectively. The results showed that the open-skill (p visuospatial short-term memory task, whereas the group difference in the visuospatial mental rotation task was not significant. These findings combined to suggest that physical exercise was associated with better visuospatial working memory in older adults. Furthermore, open-skill exercises that demand higher cognitive processing showed selective benefit for passive maintenance of working memory.

  11. Exploring visuospatial abilities and their contribution to constructional abilities and nonverbal intelligence.

    Science.gov (United States)

    Trojano, Luigi; Siciliano, Mattia; Cristinzio, Chiara; Grossi, Dario

    2017-01-09

    The present study aimed at exploring relationships among the visuospatial tasks included in the Battery for Visuospatial Abilities (BVA), and at assessing the relative contribution of different facets of visuospatial processing on tests tapping constructional abilities and nonverbal abstract reasoning. One hundred forty-four healthy subjects with a normal score on Mini Mental State Examination completed the BVA plus Raven's Coloured Progressive Matrices and Constructional Apraxia test. We used Principal Axis Factoring and Parallel Analysis to investigate relationships among the BVA visuospatial tasks, and performed regression analyses to assess the visuospatial contribution to constructional abilities and nonverbal abstract reasoning. Principal Axis Factoring and Parallel Analysis revealed two eigenvalues exceeding 1, accounting for about 60% of the variance. A 2-factor model provided the best fit. Factor 1 included sub-tests exploring "complex" visuospatial skills, whereas Factor 2 included two subtests tapping "simple" visuospatial skills. Regression analyses revealed that both Factor 1 and Factor 2 significantly affected performance on Raven's Coloured Progressive Matrices, whereas only the Factor 1 affected performance on Constructional Apraxia test. Our results supported functional segregation proposed by De Renzi, suggesting clinical caution to utilize a single test to assess visuospatial domain, and qualified the visuospatial contribution in drawing and non-verbal intelligence test.

  12. 帕金森病患者视空间能力损害研究%Deficit of visuospatial information processing in parkinson’s disease

    Institute of Scientific and Technical Information of China (English)

    席春华; 朱幼玲; 穆燕芳; 张婷婷; 董斌; 汪凯

    2015-01-01

    目的:探讨早、中期帕金森病(parkinson’s disease,PD)患者的视空间感知能力和视空间物体组织能力损害特点。方法选取早、中期 PD 患者19例以及人口学资料与其相匹配的18例健康对照组作为研究被试,神经心理学背景测试采用简易精神状态评价量表(MMSE)、汉密顿抑郁量表(HAMD)、数字广度、词汇流畅性,Stroop 字色干扰实验以及听觉词汇学习等测试被试的总体认知、情绪、记忆以及执行功能。采用视觉线段方向判断测试被试视空间的感知能力,采用 Hooper 视觉组织任务测试被试的视空间物体的组织能力。结果相对于正常对照组,早、中期 PD 患者在词汇流畅性,Stroop 字色干扰实验,听觉词汇的延迟再认差异均有统计学意义(P <0.05)。在视空间能力方面,PD 组在视觉线段方向能力与对照组差异无统计学意义(P >0.05);而在 Hooper 视觉组织任务中,PD 组的视空间物体的组织能力较对照组明显下降,差异有统计学意义(P <0.05);经 Pearson 相关分析,我们发现 PD 患者的视空间物体的组织能力与其疾病的严重程度并没有明显相关性(P >0.05)。结论早、中期 PD 患者不仅存在记忆及执行功能损害,同时视空间能力损害,而这种视空间能力损害可能主要表现为视空间物体的组织和重建能力。%Objective To investigate the characteristics of visuospatial information processing impairment in early/moderate stages Pa-kinsion’s disease (PD)patients.Methods A total of 19 individuals with idiopathic PD were compared with matched healthy controls (HC)on the judgment of line orientation test (JLOT)and the hooper visual organization task (HVOT).A series of battery including the assessment of global cognition,emotion,memory and executive function was also administered.The severity of disease was assessed based on the Hohen and

  13. How skill expertise shapes the brain functional architecture: an fMRI study of visuo-spatial and motor processing in professional racing-car and naïve drivers.

    Science.gov (United States)

    Bernardi, Giulio; Ricciardi, Emiliano; Sani, Lorenzo; Gaglianese, Anna; Papasogli, Alessandra; Ceccarelli, Riccardo; Franzoni, Ferdinando; Galetta, Fabio; Santoro, Gino; Goebel, Rainer; Pietrini, Pietro

    2013-01-01

    The present study was designed to investigate the brain functional architecture that subserves visuo-spatial and motor processing in highly skilled individuals. By using functional magnetic resonance imaging (fMRI), we measured brain activity while eleven Formula racing-car drivers and eleven 'naïve' volunteers performed a motor reaction and a visuo-spatial task. Tasks were set at a relatively low level of difficulty such to ensure a similar performance in the two groups and thus avoid any potential confounding effects on brain activity due to discrepancies in task execution. The brain functional organization was analyzed in terms of regional brain response, inter-regional interactions and blood oxygen level dependent (BOLD) signal variability. While performance levels were equal in the two groups, as compared to naïve drivers, professional drivers showed a smaller volume recruitment of task-related regions, stronger connections among task-related areas, and an increased information integration as reflected by a higher signal temporal variability. In conclusion, our results demonstrate that, as compared to naïve subjects, the brain functional architecture sustaining visuo-motor processing in professional racing-car drivers, trained to perform at the highest levels under extremely demanding conditions, undergoes both 'quantitative' and 'qualitative' modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks. These results provide novel evidence in favor of an increased 'neural efficiency' in the brain of highly skilled individuals.

  14. Brain correlates of negative and positive visuospatial priming in adults.

    Science.gov (United States)

    Wright, Christopher I; Keuthen, Nancy J; Savage, Cary R; Martis, Brian; Williams, Danielle; Wedig, Michelle; McMullin, Katherine; Rauch, Scott L

    2006-04-15

    A balance of inhibitory and facilitatory mechanisms is essential for efficient and goal-directed behaviors. These mechanisms may go awry in several neuropsychiatric disorders characterized by uncontrolled, repetitive behaviors. The visuospatial priming paradigm is a well-established probe of inhibition and facilitation that has been used to demonstrate behavioral deficits in patients with Tourette syndrome and obsessive-compulsive disorder. However, the brain correlates of this visuospatial priming paradigm are not yet well established. In the present study, we used a visuospatial priming paradigm and event-related functional MRI, to probe inhibitory and facilitatory brain mechanisms in healthy adult women. When subjects performed the negative priming (i.e., inhibitory) task, several regions of the prefrontal cortex were selectively activated relative to the neutral condition. Non-overlapping regions of the prefrontal cortex were deactivated in the positive priming condition. These results support the notion that the prefrontal cortex is involved in both inhibitory and facilitatory processing and demonstrate that this visuospatial priming task shares brain correlates with other positive and negative priming tasks. In conjunction with functional MRI, this visuospatial priming task may be useful for studying the pathophysiology of neuropsychiatric disorders in which deficient inhibitory processing or excessive facilitation is a feature.

  15. Developmental gains in visuospatial memory predict gains in mathematics achievement.

    Science.gov (United States)

    Li, Yaoran; Geary, David C

    2013-01-01

    Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4) were larger than gains in the capacity of the central executive (d = 1.6) that in turn were larger than gains in phonological memory span (d = 1.1). First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

  16. Exploring the unknown: electrophysiological and behavioural measures of visuospatial learning.

    Science.gov (United States)

    Quinlivan, Brendan; Butler, John S; Ridwan, Abdur Raquib; Beiser, Ines; Williams, Laura; McGovern, Eavan; O'Riordan, Sean; Hutchinson, Michael; Reilly, Richard B

    2016-05-01

    Visuospatial memory describes our ability to temporarily store and manipulate visual and spatial information and is employed for a wide variety of complex cognitive tasks. Here, a visuospatial learning task requiring fine motor control is employed to investigate visuospatial learning in a group of typically developing adults. Electrophysiological and behavioural data are collected during a target location task under two experimental conditions: Target Learning and Target Cued. Movement times (MTs) are employed as a behavioural metric of performance, while dynamic P3b amplitudes and power in the alpha band (approximately 10 Hz) are explored as electrophysiological metrics during visuospatial learning. Results demonstrate that task performance, as measured by MT, is highly correlated with P3b amplitude and alpha power at a consecutive trial level (trials 1-30). The current set of results, in conjunction with the existing literature, suggests that changes in P3b amplitude and alpha power could correspond to different aspects of the learning process. Here it is hypothesized that changes in P3b correspond to a diminishing inter-stimulus interval and reduced stimulus relevance, while the corresponding changes in alpha power represent an automation of response as habituation occurs in participants. The novel analysis presented in the current study demonstrates how gradual electrophysiological changes can be tracked during the visuospatial learning process under the current paradigm.

  17. Developmental gains in visuospatial memory predict gains in mathematics achievement.

    Directory of Open Access Journals (Sweden)

    Yaoran Li

    Full Text Available Visuospatial competencies are related to performance in mathematical domains in adulthood, but are not consistently related to mathematics achievement in children. We confirmed the latter for first graders and demonstrated that children who show above average first-to-fifth grade gains in visuospatial memory have an advantage over other children in mathematics. The study involved the assessment of the mathematics and reading achievement of 177 children in kindergarten to fifth grade, inclusive, and their working memory capacity and processing speed in first and fifth grade. Intelligence was assessed in first grade and their second to fourth grade teachers reported on their in-class attentive behavior. Developmental gains in visuospatial memory span (d = 2.4 were larger than gains in the capacity of the central executive (d = 1.6 that in turn were larger than gains in phonological memory span (d = 1.1. First to fifth grade gains in visuospatial memory and in speed of numeral processing predicted end of fifth grade mathematics achievement, as did first grade central executive scores, intelligence, and in-class attentive behavior. The results suggest there are important individual differences in the rate of growth of visuospatial memory during childhood and that these differences become increasingly important for mathematics learning.

  18. Numerical simulation study of the failure evolution process and failure mode of surrounding rock in deep soft rock roadways

    Institute of Scientific and Technical Information of China (English)

    Meng Qingbin; Han Lijun; Xiao Yu; Li Hao; Wen Shengyong; Zhang Jian

    2016-01-01

    Based on the safety coefficient method, which assigns rock failure criteria to calculate the rock mass unit, the safety coefficient contour of surrounding rock is plotted to judge the distribution form of the frac-tured zone in the roadway. This will provide the basis numerical simulation to calculate the surrounding rock fractured zone in a roadway. Using the single factor and multi-factor orthogonal test method, the evolution law of roadway surrounding rock displacements, plastic zone and stress distribution under different conditions is studied. It reveals the roadway surrounding rock burst evolution process, and obtains five kinds of failure modes in deep soft rock roadway. Using the fuzzy mathematics clustering analysis method, the deep soft surrounding rock failure model in Zhujixi mine can be classified and pat-terns recognized. Compared to the identification results and the results detected by geological radar of surrounding rock loose circle, the reliability of the results of the pattern recognition is verified and lays the foundations for the support design of deep soft rock roadways.

  19. Differential Impact of Visuospatial Working Memory on Rule-based and Information-integration Category Learning.

    Science.gov (United States)

    Xing, Qiang; Sun, Hailong

    2017-01-01

    Previous studies have indicated that the category learning system is a mechanism with multiple processing systems, and that working memory has different effects on category learning. But how does visuospatial working memory affect perceptual category learning? As there is no definite answer to this question, we conducted three experiments. In Experiment 1, the dual-task paradigm with sequential presentation was adopted to investigate the influence of visuospatial working memory on rule-based and information-integration category learning. The results showed that visuospatial working memory interferes with rule-based but not information-integration category learning. In Experiment 2, the dual-task paradigm with simultaneous presentation was used, in which the categorization task was integrated into the visuospatial working memory task. The results indicated that visuospatial working memory affects information-integration category learning but not rule-based category learning. In Experiment 3, the dual-task paradigm with simultaneous presentation was employed, in which visuospatial working memory was integrated into the category learning task. The results revealed that visuospatial working memory interferes with both rule-based and information-integration category learning. Through these three experiments, we found that, regarding the rule-based category learning, working memory load is the main mechanism by which visuospatial working memory influences the discovery of the category rules. In addition, regarding the information-integration category learning, visual resources mainly operates on the category representation.

  20. Visuospatial Functioning in Cerebral Amyloid Angiopathy : A Pilot Study

    NARCIS (Netherlands)

    Valenti, Raffaella; Charidimou, Andreas; Xiong, Li; Boulouis, Gregoire; Fotiadis, Panagiotis; Ayres, Alison; Riley, Grace; Kuijf, Hugo J.|info:eu-repo/dai/nl/341734888; Reijmer, Yael D.; Pantoni, Leonardo; Gurol, M. Edip; Davidsdottir, Sigurros; Greenberg, Steven M.; Viswanathan, Anand

    2017-01-01

    Cerebral amyloid angiopathy (CAA) is a contributor to cognitive impairment in the elderly. We hypothesized that the posterior cortical predilection of CAA would cause visual-processing impairment. We systematically evaluated visuospatial abilities in 22 non-demented CAA patients. Neurocognitive

  1. The Ghosts of Higher Education Reform: On the Organisational Processes Surrounding Policy Borrowing

    Science.gov (United States)

    Brøgger, Katja

    2014-01-01

    The Bologna Process is one of the most extensive examples of policy borrowing processes. Based on qualitative data, this article argues in favour of studying part of this process as "global smallness", centring on the organisational effects of the implementation of a globalised curriculum. Through Derrida's notion on hauntology,…

  2. Driving and visuospatial performance in people with hemianopia

    NARCIS (Netherlands)

    Tant, M.L.; Brouwer, W.H.; Cornelissen, F.W; Kooijman, A.C

    2002-01-01

    Practical fitness to drive was studied in 28 patients with homonymous hemianopia (HH). More specifically, visual performance during driving and neuropsychological visuospatial test performance were compared and related. Visuospatial tests were a priori classified in four visuospatial sets, and were

  3. The neural underpinings of simultanagnosia: disconnecting the visuospatial attention network.

    Science.gov (United States)

    Chechlacz, Magdalena; Rotshtein, Pia; Hansen, Peter C; Riddoch, Jane M; Deb, Shoumitro; Humphreys, Glyn W

    2012-03-01

    Because of our limited processing capacity, different elements of the visual scene compete for the allocation of processing resources. One of the most striking deficits in visual selection is simultanagnosia, a rare neuropsychological condition characterized by impaired spatial awareness of more than one object at time. To decompose the neuroanatomical substrates of the syndrome and to gain insights into the structural and functional organization of visuospatial attention, we performed a systematic evaluation of lesion patterns in a group of simultanagnosic patients compared with patients with either (i) unilateral visuospatial deficits (neglect and/or extinction) or (ii) bilateral posterior lesions without visuospatial deficits, using overlap/subtraction analyses, estimation of lesion volume, and a lesion laterality index. We next used voxel-based morphometry to assess the link between different visuospatial deficits and gray matter and white matter (WM) damage. Lesion overlap/subtraction analyses, lesion laterality index, and voxel-based morphometry measures converged to indicate that bilateral parieto-occipital WM disconnections are both distinctive and necessary to create symptoms associated with simultanagnosia. We also found that bilateral gray matter damage within the middle frontal area (BA 46), cuneus, calacarine, and parieto-occipital fissure as well as right hemisphere parietal lesions within intraparietal and postcentral gyri were associated with simultanagnosia. Further analysis of the WM based on tractography revealed associations with bilateral damage to major pathways within the visuospatial attention network, including the superior longitudinal fasciculus, the inferior fronto-occipital fasciculus, and the inferior longitudinal fasciculus. We conclude that damage to the parieto-occipital regions and the intraparietal sulcus, together, with bilateral WM disconnections within the visuosptial attention network, contribute to poor visual processing of

  4. Does field independence predict visuo-spatial abilities underpinning human navigation? Behavioural evidence.

    Science.gov (United States)

    Boccia, Maddalena; Piccardi, Laura; Di Marco, Mariangela; Pizzamiglio, Luigi; Guariglia, Cecilia

    2016-10-01

    Field independence (FI) has been defined as the extent to which the individual perceives part of a field as discrete from the surrounding field, rather than embedded in the field. It has been proposed to represent a relatively stable pattern in individuals' predisposition towards information processing. In the present study, we assessed the effect of FI on skills underpinning human navigation. Fifty Healthy individuals took part in this study. FI has been assessed by using the group embedded figures test (GEFT). Participants were also asked to perform several visuo-spatial orientation tasks, including the perspective taking/spatial orientation test (PTSOT), the mental rotation task (MRT) and the vividness task, as well as the Santa Barbara Sense of Direction Scale, a self-reported questionnaire, which has been found to predict environmental spatial orientation ability. We found that performances on the GEFT significantly predicted performances on the PTSOT and the MRT. This result supports the idea that FI predicts human navigation.

  5. Acoustic and physiological effects of the surroundings in rock cutting process

    Directory of Open Access Journals (Sweden)

    Lucia Ivaničová

    2010-03-01

    Full Text Available A noise effect arising in the rock cutting process is gaining a large attention as to the identification and optimization of the cuttingprocess. The sense experience acquired during the experiments in the process of rotary rock drilling related to the determination of rock typeor to the optimal drilling regime determination is formed due to sense perception, mainly hearing, and its further evaluation by the humanbrain from the information exempted from the environment.

  6. Visuospatial tasks affect locomotor control more than nonspatial tasks in older people.

    Directory of Open Access Journals (Sweden)

    Jasmine C Menant

    Full Text Available Previous research has shown that visuospatial processing requiring working memory is particularly important for balance control during standing and stepping, and that limited spatial encoding contributes to increased interference in postural control dual tasks. However, visuospatial involvement during locomotion has not been directly determined. This study examined the effects of a visuospatial cognitive task versus a nonspatial cognitive task on gait speed, smoothness and variability in older people, while controlling for task difficulty.Thirty-six people aged ≥75 years performed three walking trials along a 20 m walkway under the following conditions: (i an easy nonspatial task; (ii a difficult nonspatial task; (iii an easy visuospatial task; and (iv a difficult visuospatial task. Gait parameters were computed from a tri-axial accelerometer attached to the sacrum. The cognitive task response times and percentage of correct answers during walking and seated trials were also computed.No significant differences in either cognitive task type error rates or response times were evident in the seated conditions, indicating equivalent task difficulty. In the walking trials, participants responded faster to the visuospatial tasks than the nonspatial tasks but at the cost of making significantly more cognitive task errors. Participants also walked slower, took shorter steps, had greater step time variability and less smooth pelvis accelerations when concurrently performing the visuospatial tasks compared with the nonspatial tasks and when performing the difficult compared with the easy cognitive tasks.Compared with nonspatial cognitive tasks, visuospatial cognitive tasks led to a slower, more variable and less smooth gait pattern. These findings suggest that visuospatial processing might share common networks with locomotor control, further supporting the hypothesis that gait changes during dual task paradigms are not simply due to limited attentional

  7. The Structure of Visuospatial Memory in Adulthood

    Science.gov (United States)

    Mammarella, Irene C.; Borella, Erika; Pastore, Massimiliano; Pazzaglia, Francesca

    2013-01-01

    The present study aimed to investigate the structure of visuospatial memory in adulthood. Adults 40-89 years of age (n = 160) performed simple storage and complex visuospatial span tasks. Simple storage tasks were distinguished into three presentation formats: (i) visual, which involved maintaining shapes and textures; (ii) spatial-sequential,…

  8. The Effect of Ozonation Process on Bromide-Containing Groundwaters in Bandung Area and Its Surroundings

    Directory of Open Access Journals (Sweden)

    Mindriany Syafila

    2012-11-01

    Full Text Available Disinfection process was applied as the last step of the water treatment to kill pathogenic bacteria in the water. However, according to several studies, the ozonation disinfection process could form undesired by-products. One of the by-products potentially affecting human life is bromate produced from bromide ionic-containing water. This study was carried out to examine the effect of raw water characteristics and pH on bromate formation. Also, the performance of bromate formation for a period of exposure time was analyzed. Raw waters taken from four different areas around Bandung were exposed to ozone introduced to a reactor with a flow rate of 2 L/min. The pH of the raw waters varied from 4, 7 to 10. The results show that there was no evidence of an initial bromide ion concentration, whereas a change in pH value gives a significantly different outcome. In acidic condition (pH of 4 the bromate formation tends to decrease, whereas when the pH value increases to a pH of 10, the bromate formation increases. Therefore, for drinking water with a neutral pH, when bromide ions are detected in the raw water, the drinking water may be toxic due to the presence of bromate.

  9. Processing and Monthly Summaries of Downscaled Climate Data for Knoxville, Tennessee and Surrounding Region

    Energy Technology Data Exchange (ETDEWEB)

    Sylvester, Linda M [ORNL; Omitaomu, Olufemi A [ORNL; Parish, Esther S [ORNL; Allen, Melissa R [ORNL

    2016-09-01

    Oak Ridge National Laboratory (ORNL) and the City of Knoxville, Tennessee have partnered to work on a Laboratory Directed Research and Development (LDRD) project towards investigating climate change, mitigation, and adaptation measures in mid-sized cities. ORNL has statistically and dynamically downscaled ten Global Climate Models (GCMs) to both 1 km and 4 km resolutions. The processing and summary of those ten gridded datasets for use in a web-based tool is described. The summaries of each model are shown individually to assist in determining the similarities and differences between the model scenarios. The variables of minimum and maximum daily temperature and total monthly precipitation are summarized for the area of Knoxville, Tennessee for the periods of 1980-2005 and 2025-2050.

  10. Gender-related differences in visuospatial memory persist in Alzheimer's disease.

    Science.gov (United States)

    Millet, Xavier; Raoux, Nadine; Le Carret, Nicolas; Bouisson, Jean; Dartigues, Jean-François; Amieva, Hélène

    2009-12-01

    Gender differences in visuospatial cognition favoring men are larger in tasks requiring active information manipulation than in tasks requiring passive storage. This study was designed to determine whether male advantage in active manipulation of visuospatial information can still be evidenced in Alzheimer's disease (AD). Twenty male and 20 female AD patients with equivalent age, education, dementia severity (Mini-Mental State Examination and Mattis Dementia Rating Scale), and visual discrimination abilities were recruited. We administered the forward span of Corsi block-tapping task and Vecchi's matrix memory task involving passive temporary retention of stimuli location. Active manipulation of visuospatial information was assessed with the backward span of Corsi block-tapping task and Vecchi's pathway task in which patients were required to mentally generate a pathway within a matrix. The results showed that scores on the tasks involving passive storage of visuospatial information were equivalent between the two groups of patients, whereas men performed significantly better than women in tasks requiring active manipulation of visuospatial information. This result was limited to visuospatial processing since no difference between male and female patients was evidenced in the verbal short-term memory tasks, neither when the task involved passive storage nor when the task required active processing. Therefore, this study suggests that, besides other variables such as education or lifestyle factors, gender might also modulate the cognitive manifestation of AD.

  11. Visuospatial and verbal memory in mental arithmetic.

    Science.gov (United States)

    Clearman, Jack; Klinger, Vojtěch; Szűcs, Dénes

    2016-08-01

    Working memory allows complex information to be remembered and manipulated over short periods of time. Correlations between working memory and mathematics achievement have been shown across the lifespan. However, only a few studies have examined the potentially distinct contributions of domain-specific visuospatial and verbal working memory resources in mental arithmetic computation. Here we aimed to fill this gap in a series of six experiments pairing addition and subtraction tasks with verbal and visuospatial working memory and interference tasks. In general, we found higher levels of interference between mental arithmetic and visuospatial working memory tasks than between mental arithmetic and verbal working memory tasks. Additionally, we found that interference that matched the working memory domain of the task (e.g., verbal task with verbal interference) lowered working memory performance more than mismatched interference (verbal task with visuospatial interference). Findings suggest that mental arithmetic relies on domain-specific working memory resources.

  12. Visuospatial integration and human evolution: the fossil evidence.

    Science.gov (United States)

    Bruner, Emiliano; Lozano, Marina; Lorenzo, Carlos

    2016-06-20

    Visuospatial integration concerns the ability to coordinate the inner and outer environments, namely the central nervous system and the outer spatial elements, through the interface of the body. This integration is essential for every basic human activity, from locomotion and grasping to speech or tooling. Visuospatial integration is even more fundamental when dealing with theories on extended mind, embodiment, and material engagement. According to the hypotheses on extended cognition, the nervous system, the body and the external objects work as a single integrated unit, and what we call "mind" is the process resulting from such interaction. Because of the relevance of culture and material culture in humans, important changes in such processes were probably crucial for the evolution of Homo sapiens. Much information in this sense can be supplied by considering issues in neuroarchaeology and cognitive sciences. Nonetheless, fossils and their anatomy can also provide evidence according to changes involving physical and body aspects. In this article, we review three sources of morphological information concerning visuospatial management and fossils: evolutionary neuroanatomy, manipulative behaviors, and hand evolution.

  13. A relationship between gonadotropins and visuospatial function.

    Science.gov (United States)

    Gordon, H W; Lee, P A

    1986-01-01

    Follicle Stimulating Hormone (FSH) levels were negatively correlated with visuospatial function in two successive testing sessions in 32 young adult men. Men with high concentrations of FSH performed poorly on three-dimensional tests and tests of point localization. Men with low concentrations tended to perform better. Luteinizing Hormone (LH) tended to correlate positively with verbal/sequential skills and with two of the visuospatial skills for one session; testosterone was positively correlated with one spatial test. Multiple regression between the average performance on visuospatial tests and the three hormones produced Rs of 0.67 and 0.60, accounting for 39% and 29% of the variance, respectively, in Sessions 1 and 2. In women, the hormonal/behavior relationships were less clear although in many ways similar. For example, FSH was negatively correlated with one visuospatial test but only after the effects of estradiol and progesterone were partialled out. FSH was positively correlated with word fluency as was LH. With respect to sex differences women were poorer than men on the visuospatial tests and better on verbal fluency which is consistent with women's generally higher FSH levels and the negative relationship between FSH and visuospatial skills and the positive relationship with fluency.

  14. The Shortened Visuospatial Questionnaire for Children: A Useful Tool to Identify Students with Low Visuospatial Abilities

    Science.gov (United States)

    Fastame, Maria Chiara; Cherchi, Rossella; Penna, Maria Pietronilla

    2015-01-01

    The current research was aimed mainly at exploring the reliability of a short-screening tool developed to self-evaluate visuospatial abilities in children. We presented 290 Italian third, fourth, and fifth graders with the 16-item Shortened Visuospatial questionnaire and several objective measures of intellectual efficiency, such as Raven's…

  15. Enhancing visuospatial performance through video game training to increase learning in visuospatial science domains.

    Science.gov (United States)

    Sanchez, Christopher A

    2012-02-01

    Although previous research has demonstrated that performance on visuospatial assessments can be enhanced through relevant experience, an unaddressed question is whether such experience also produces a similar increase in target domains (such as science learning) where visuospatial abilities are directly relevant for performance. In the present study, participants completed either spatial or nonspatial training via interaction with video games and were then asked to read and learn about the geologic topic of plate tectonics. Results replicate the benefit of playing appropriate video games in enhancing visuospatial performance and demonstrate that this facilitation also manifests itself in learning science topics that are visuospatial in nature. This novel result suggests that visuospatial training not only can impact performance on measures of spatial functioning, but also can affect performance in content areas in which these abilities are utilized.

  16. Exploring visuospatial thinking in chemistry learning

    Science.gov (United States)

    Wu, Hsin-Kai; Shah, Priti

    2004-05-01

    In this article, we examine the role of visuospatial cognition in chemistry learning. We review three related kinds of literature: correlational studies of spatial abilities and chemistry learning, students' conceptual errors and difficulties understanding visual representations, and visualization tools that have been designed to help overcome these limitations. On the basis of our review, we conclude that visuospatial abilities and more general reasoning skills are relevant to chemistry learning, some of students' conceptual errors in chemistry are due to difficulties in operating on the internal and external visuospatial representations, and some visualization tools have been effective in helping students overcome the kinds of conceptual errors that may arise through difficulties in using visuospatial representations. To help students understand chemistry concepts and develop representational skills through supporting their visuospatial thinking, we suggest five principles for designing chemistry visualization tools: (1) providing multiple representations and descriptions, (2) making linked referential connections visible, (3) presenting the dynamic and interactive nature of chemistry, (4) promoting the transformation between 2D and 3D, and (5) reducing cognitive load by making information explicit and integrating information for students.

  17. The relationship between different exercise modes and visuospatial working memory in older adults: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Wei Guo

    2016-07-01

    Full Text Available The purpose of the study was to investigate the relationship between different exercise modes and visuospatial working memory in healthy older adults. A cross-sectional design was adopted. A total of 111 healthy older adults were enrolled in the study. They were classified by the exercise-related questionnaire to be in an open-skill group, closed-skill group or sedentary group. In experiment 1, the participants performed a visuospatial working memory task. The results indicated that both closed-skill (p < 0.05 and open-skill (p < 0.01 groups reached a higher accuracy than the sedentary group. Experiment 2 examined whether the exercise-induced benefit of working memory was manifested in passive maintenance or active manipulation of working memory which was assessed by visuospatial short-term memory task and visuospatial mental rotation task, respectively. The results showed that the open-skill (p < 0.01 group was more accurate than the sedentary group in the visuospatial short-term memory task, whereas the group difference in the visuospatial mental rotation task was not significant. These findings combined to suggest that physical exercise was associated with better visuospatial working memory in older adults. Furthermore, open-skill exercises that demand higher cognitive processing showed selective benefit for passive maintenance of working memory.

  18. Exceptional visuospatial imagery in schizophrenia; implications for madness and creativity

    OpenAIRE

    Taylor eBenson; Sohee ePark

    2013-01-01

    Biographical and historical accounts suggest a link between scientific creativity and schizophrenia. Longitudinal studies of gifted children indicate that visuospatial imagery plays a pivotal role in exceptional achievements in science and mathematics. We asked whether visuospatial imagery is enhanced in individuals with schizophrenia (SZ). We compared SZ and matched healthy controls (HC) on five visuospatial tasks tapping parietal and frontoparietal functions. Two aspects of visuospatial tra...

  19. Visuo-spatial ability in colonoscopy simulator training

    OpenAIRE

    Luursema, J.-M.; Buzink, S.N.; Verwey, W.B.; Jakimowicz, J.J.

    2010-01-01

    Visuo-spatial ability is associated with a quality of performance in a variety of surgical and medical skills. However, visuo-spatial ability is typically assessed using Visualization tests only, which led to an incomplete understanding of the involvement of visuo-spatial ability in these skills. To remedy this situation, the current study investigated the role of a broad range of visuo-spatial factors in colonoscopy simulator training. Fifteen medical trainees (no clinical experience in colo...

  20. Visuo-spatial ability in colonoscopy simulator training

    NARCIS (Netherlands)

    Luursema, J.-M.; Buzink, S.N.; Verwey, W.B.; Jakimowicz, J.J.

    2010-01-01

    Visuo-spatial ability is associated with a quality of performance in a variety of surgical and medical skills. However, visuo-spatial ability is typically assessed using Visualization tests only, which led to an incomplete understanding of the involvement of visuo-spatial ability in these skills. To

  1. Visuospatial Ability Factors and Performance Variables in Laparoscopic Simulator Training

    Science.gov (United States)

    Luursema, Jan-Maarten; Verwey, Willem B.; Burie, Remke

    2012-01-01

    Visuospatial ability has been shown to be important to several aspects of laparoscopic performance, including simulator training. Only a limited subset of visuospatial ability factors however has been investigated in such studies. Tests for different visuospatial ability factors differ in stimulus complexity, in their emphasis on identifying…

  2. Visuospatial ability factors and performance variables in laparoscopic simulator training

    NARCIS (Netherlands)

    Luursema, J.-M.; Verwey, W.B.; Burie, R.

    2012-01-01

    Visuospatial ability has been shown to be important to several aspects of laparoscopic performance, including simulator training. Only a limited subset of visuospatial ability factors however has been investigated in such studies. Tests for different visuospatial ability factors differ in stimulus c

  3. 'Eavesdropping' on social interactions biases threat perception in visuospatial pathways.

    Science.gov (United States)

    Lloyd, Donna M; Morrison, C India

    2008-01-15

    Using fMRI, we measured brain activity while participants viewed photographs in which one person posed a potential threat to another. Visuospatial areas, specifically temporal-occipital junction, extrastriate, and fusiform cortices and right superior parietal lobe (BA7), responded when a threatening person was close to the personal space of another. Strikingly, this selectivity was absent when the people were further apart. Furthermore, posterior parietal areas, which code the space surrounding one's own body, responded when the individual was close to the other person's body space, regardless of whether he appeared threatening. We suggest that the spatial dimension of social interactions contributes to an observer's understanding of potentially dangerous social situations, and that higher level visual cortices play a role in distinguishing social categories based on a person's features.

  4. The effects of environmental support and secondary tasks on visuospatial working memory.

    Science.gov (United States)

    Lilienthal, Lindsey; Hale, Sandra; Myerson, Joel

    2014-10-01

    In the present experiments, we examined the effects of environmental support on participants' ability to rehearse locations and the role of such support in the effects of secondary tasks on memory span. In Experiment 1, the duration of interitem intervals and the presence of environmental support for visuospatial rehearsal (i.e., the array of possible memory locations) during the interitem intervals were both manipulated across four tasks. When support was provided, memory spans increased as the interitem interval durations increased, consistent with the hypothesis that environmental support facilitates rehearsal. In contrast, when environmental support was not provided, spans decreased as the duration of the interitem intervals increased, consistent with the hypothesis that visuospatial memory representations decay when rehearsal is impeded. In Experiment 2, the ratio of interitem interval duration to intertrial interval duration was kept the same on all four tasks, in order to hold temporal distinctiveness constant, yet forgetting was still observed in the absence of environmental support, consistent with the decay hypothesis. In Experiment 3, the effects of impeding rehearsal were compared to the effects of verbal and visuospatial secondary processing tasks. Forgetting of locations was greater when presentation of to-be-remembered locations alternated with the performance of a secondary task than when rehearsal was impeded by the absence of environmental support. The greatest forgetting occurred when a secondary task required the processing visuospatial information, suggesting that in addition to decay, both domain-specific and domain-general effects contribute to forgetting on visuospatial working memory tasks.

  5. Sports training enhances visuo-spatial cognition regardless of open-closed typology

    Directory of Open Access Journals (Sweden)

    Ting-Yu Chueh

    2017-05-01

    Full Text Available The aim of this study was to investigate the effects of open and closed sport participation on visuo-spatial attention and memory performance among young adults. Forty-eight young adults—16 open-skill athletes, 16 closed-skill athletes, and 16 non-athletes controls—were recruited for the study. Both behavioral performance and event-related potential (ERP measurement were assessed when participants performed non-delayed and delayed match-to-sample task that tested visuo-spatial attention and memory processing. Results demonstrated that regardless of training typology, the athlete groups exhibited shorter reaction times in both the visuo-spatial attention and memory conditions than the control group with no existence of speed-accuracy trade-off. Similarly, a larger P3 amplitudes were observed in both athlete groups than in the control group for the visuo-spatial memory condition. These findings suggest that sports training, regardless of typology, are associated with superior visuo-spatial attention and memory performance, and more efficient neural resource allocation in memory processing.

  6. Movement Interferes with Visuospatial Working Memory during the Encoding: An ERP Study

    Directory of Open Access Journals (Sweden)

    Rumeysa Gunduz Can

    2017-05-01

    Full Text Available The present study focuses on the functional interactions of cognition and manual action control. Particularly, we investigated the neurophysiological correlates of the dual-task costs of a manual-motor task (requiring grasping an object, holding it, and subsequently placing it on a target for working memory (WM domains (verbal and visuospatial and processes (encoding and retrieval. Thirty participants were tested in a cognitive-motor dual-task paradigm, in which a single block (a verbal or visuospatial WM task was compared with a dual block (concurrent performance of a WM task and a motor task. Event-related potentials (ERPs were analyzed separately for the encoding and retrieval processes of verbal and visuospatial WM domains both in single and dual blocks. The behavioral analyses show that the motor task interfered with WM and decreased the memory performance. The performance decrease was larger for the visuospatial task compared with the verbal task, i.e., domain-specific memory costs were obtained. The ERP analyses show the domain-specific interference also at the neurophysiological level, which is further process-specific to encoding. That is, comparing the patterns of WM-related ERPs in the single block and dual block, we showed that visuospatial ERPs changed only for the encoding process when a motor task was performed at the same time. Generally, the present study provides evidence for domain- and process-specific interactions of a prepared manual-motor movement with WM (visuospatial domain during the encoding process. This study, therefore, provides an initial neurophysiological characterization of functional interactions of WM and manual actions in a cognitive-motor dual-task setting, and contributes to a better understanding of the neuro-cognitive mechanisms of motor action control.

  7. The influence of visuospatial attention on unattended auditory 40 Hz responses.

    Science.gov (United States)

    Roth, Cullen; Gupta, Cota Navin; Plis, Sergey M; Damaraju, Eswar; Khullar, Siddharth; Calhoun, Vince D; Bridwell, David A

    2013-01-01

    Information must integrate from multiple brain areas in healthy cognition and perception. The present study examined the extent to which cortical responses within one sensory modality are modulated by a complex task conducted within another sensory modality. Electroencephalographic (EEG) responses were measured to a 40 Hz auditory stimulus while individuals attended to modulations in the amplitude of the 40 Hz stimulus, and as a function of the difficulty of the popular computer game Tetris. The steady-state response to the 40 Hz stimulus was isolated by Fourier analysis of the EEG. The response at the stimulus frequency was normalized by the response within the surrounding frequencies, generating the signal-to-noise ratio (SNR). Seven out of eight individuals demonstrate a monotonic increase in the log SNR of the 40 Hz responses going from the difficult visuospatial task to the easy visuospatial task to attending to the auditory stimuli. This pattern is represented statistically by a One-Way ANOVA, indicating significant differences in log SNR across the three tasks. The sensitivity of 40 Hz auditory responses to the visuospatial load was further demonstrated by a significant correlation between log SNR and the difficulty (i.e., speed) of the Tetris task. Thus, the results demonstrate that 40 Hz auditory cortical responses are influenced by an individual's goal-directed attention to the stimulus, and by the degree of difficulty of a complex visuospatial task.

  8. Does visuo-spatial working memory generally contribute to immediate serial letter recall?

    Science.gov (United States)

    Fürstenberg, A; Rummer, R; Schweppe, J

    2013-01-01

    This work contributes to the understanding of the visual similarity effect in verbal working memory, a finding that suggests that the visuo-spatial sketch pad-the system in Baddeley's working memory model specialised in retaining nonverbal visual information-might be involved in the retention of visually presented verbal materials. Crucially this effect is implicitly interpreted by the most influential theory of multimedia learning as evidence for an obligatory involvement of the visuo-spatial sketch pad. We claim that it is only involved when the functioning of the working memory component normally used for processing verbal material is impaired. In this article we review the studies that give rise to the idea of obligatory involvement of the visuo-spatial sketch pad and suggest that some findings can be understood with reference to orthographic rather than visual similarity. We then test an alternative explanation of the finding that is most apt to serve as evidence for obligatory involvement of the visuo-spatial sketch pad. We conclude that, in healthy adults and under normal learning conditions, the visual similarity effect can be explained within the framework of verbal working memory proposed by Baddeley (e.g., 1986, 2000) without additional premises regarding the visuo-spatial sketch.

  9. Distracting visuospatial attention while approaching an obstacle reduces the toe-obstacle clearance.

    Science.gov (United States)

    Lo, On-Yee; van Donkelaar, Paul; Chou, Li-Shan

    2015-04-01

    Obstacle crossing during walking requires visuospatial attention to identify the obstacle, so that individuals can integrate visual and somatosensory information for raising the foot with appropriate height and timing without being tripped. However, the interaction between control of foot trajectory and orientation of visuospatial attention during obstacle crossing is complicated and remains unclear. This study probed where attention is directed when approaching and stepping over an obstacle during gait and examined how the presence of the obstacle affects the distribution of attention during walking. Eleven young healthy adults performed a visuospatial attention task while standing (Stand), crossing over an obstacle placed either before (ObsBefore) or after (ObsAfter) the visual target, or crossing without the visual target (ObsOnly). Toe-obstacle clearance was reduced for the trailing leg in the ObsAfter condition but remained the same for the ObsBefore and ObsOnly conditions. In addition, the accuracy rate of the visuospatial attention task tended to be higher at the locations closer to the obstacle. Taken together, these results demonstrate that visuospatial attention and the processes underlying obstacle crossing during locomotion interact in both a spatially and temporally dependent manner.

  10. Visuospatial bootstrapping: implicit binding of verbal working memory to visuospatial representations in children and adults.

    Science.gov (United States)

    Darling, Stephen; Parker, Mary-Jane; Goodall, Karen E; Havelka, Jelena; Allen, Richard J

    2014-03-01

    When participants carry out visually presented digit serial recall, their performance is better if they are given the opportunity to encode extra visuospatial information at encoding-a phenomenon that has been termed visuospatial bootstrapping. This bootstrapping is the result of integration of information from different modality-specific short-term memory systems and visuospatial knowledge in long term memory, and it can be understood in the context of recent models of working memory that address multimodal binding (e.g., models incorporating an episodic buffer). Here we report a cross-sectional developmental study that demonstrated visuospatial bootstrapping in adults (n=18) and 9-year-old children (n=15) but not in 6-year-old children (n=18). This is the first developmental study addressing visuospatial bootstrapping, and results demonstrate that the developmental trajectory of bootstrapping is different from that of basic verbal and visuospatial working memory. This pattern suggests that bootstrapping (and hence integrative functions such as those associated with the episodic buffer) emerge independent of the development of basic working memory slave systems during childhood.

  11. Relationship between visuospatial attention and paw preference in dogs.

    Science.gov (United States)

    Siniscalchi, Marcello; d'Ingeo, Serenella; Fornelli, Serena; Quaranta, Angelo

    2016-08-22

    The relationship between visuospatial attention and paw preference was investigated in domestic dogs. Visuospatial attention was evaluated using a food detection task that closely matches the so-called "cancellation" task used in human studies. Paw preference was estimated by quantifying the dog's use of forepaws to hold a puzzle feeder device (namely the "Kong") while eating its content. Results clearly revealed a strong relationship between visuospatial attention bias and motor laterality, with a left-visuospatial bias in the left-pawed group, a right-visuospatial bias in the right-pawed group and with the absence of significant visuospatial attention bias in ambi-pawed subjects. The current findings are the first evidence for the presence of a relationship between motor lateralization and visuospatial attentional mechanisms in a mammal species besides humans.

  12. The domain-specific and domain-general relationships of visuospatial working memory to reasoning ability.

    Science.gov (United States)

    Shipstead, Zach; Yonehiro, Jade

    2016-10-01

    The degree to which visuospatial working memory (VSWM) is separable from working memory in general is an open question. On one hand, the construct is often researched as a unitary, domain-specific system. On the other, there is evidence that VWSM shares a common processing component with verbal memory. One might interpret this shared component as domain-general attention. We used confirmatory factor analysis to demonstrate that VSWM shares a domain-general component with verbal memory tasks and has a domain-specific component that is independent of verbal memory. Furthermore, the domain-general component was found to correlate with reasoning ability in both the visuospatial and verbal domains. The domain-specific component only correlated with reasoning ability when the tests had a strong visuospatial component. We argue that theories of VSWM need to place greater emphasis on its multiply determined nature.

  13. Electrophysiological evidence for the action of a center-surround mechanism on semantic processing in the left hemisphere

    Directory of Open Access Journals (Sweden)

    Diana eDeacon

    2013-12-01

    Full Text Available Physiological evidence was sought for a center-surround attentional mechanism (CSM, which has been proposed to assist in the retrieval of weakly activated items from semantic memory. The CSM operates by facilitating strongly related items in the center of the weakly activated area of semantic memory, and inhibiting less strongly related items in its surround. In this study weak activation was created by having subjects acquire the meanings of new words to a recall criterion of only 50%. Subjects who attained this approximate criterion level of performance were subsequently included in a semantic priming task, during which ERPs were recorded. Primes were newly learned rare words, and targets were either synonyms, nonsynonymously related words, or unrelated words. All stimuli were presented to the RVF/LH (right visual field/left hemisphere or the LVF/RH (left visual field/right hemisphere. Under RVF/LH stimulation the newly learned word primes produced facilitation on N400 for synonym targets, and inhibition for related targets. No differences were observed under LVF/RH stimulation. The LH thus, supports a CSM, whereby a synonym in the center of attention focused on the newly learned word is facilitated, whereas a related word in the surround is inhibited. The data are consistent with the view of this laboratory that semantic memory is subserved by a spreading activation system in the LH. Also consistent with our view, there was no evidence of spreading activation in the RH. The findings are discussed in the context of additional recent theories of semantic memory. Finally, the adult right hemisphere may require more learning than the LH in order to demonstrate evidence of meaning acquisition.

  14. TMS pulses on the frontal eye fields break coupling between visuospatial attention and eye movements

    NARCIS (Netherlands)

    Neggers, S.F.W.; Huijbers, W.; Vrijlandt, C.M.; Vlaskamp, B.N.S.; Schutter, D.J.L.G.; Kenemans, J.L.

    2007-01-01

    While preparing a saccadic eye movement, visual processing of the saccade goal is prioritized. Here, we provide evidence that the frontal eye fields (FEFs) are responsible for this coupling between eye movements and shifts of visuospatial attention. Functional magnetic resonance imaging ( fMRI)-guid

  15. Protein Structure Prediction with Visuospatial Analogy

    Science.gov (United States)

    Davies, Jim; Glasgow, Janice; Kuo, Tony

    We show that visuospatial representations and reasoning techniques can be used as a similarity metric for analogical protein structure prediction. Our system retrieves pairs of α-helices based on contact map similarity, then transfers and adapts the structure information to an unknown helix pair, showing that similar protein contact maps predict similar 3D protein structure. The success of this method provides support for the notion that changing representations can enable similarity metrics in analogy.

  16. Relationship between visuospatial attention and paw preference in dogs

    OpenAIRE

    Marcello Siniscalchi; Serenella d’Ingeo; Serena Fornelli; Angelo Quaranta

    2016-01-01

    The relationship between visuospatial attention and paw preference was investigated in domestic dogs. Visuospatial attention was evaluated using a food detection task that closely matches the so-called “cancellation” task used in human studies. Paw preference was estimated by quantifying the dog’s use of forepaws to hold a puzzle feeder device (namely the “Kong”) while eating its content. Results clearly revealed a strong relationship between visuospatial attention bias and motor laterality, ...

  17. Subclinical visuospatial impairment in Parkinson's disease: the role of basal ganglia and limbic system

    Directory of Open Access Journals (Sweden)

    Stefano eCaproni

    2014-08-01

    Full Text Available BACKGROUND: Visual perception deficits are a recurrent manifestation in Parkinson's disease (PD. Recently, structural abnormalities of fronto-parietal areas and subcortical regions, implicated in visual stimuli analysis, have been observed in PD patients with cognitive decline and visual hallucinations. The aim of the present study was to investigate the salient aspects of visual perception in cognitively unimpaired PD patients. METHODS: Eleven right-handed non-demented right-sided onset PD patients without visuospatial impairment or hallucinations and eleven healthy controls were studied with fMRI while performing a specific visuoperceptual/visuospatial paradigm that allowed to highlight the specific process underlying visuospatial judgment. RESULTS: Significant changes in both cortical areas and subcortical regions involved in visual stimuli processing were observed. In particular, PD patients showed a reduced activation for the right insula, left putamen, bilateral caudate and right hippocampus, as well as an over-activation of the right dorso-lateral prefrontal and of the posterior parietal cortices, particularly in the right hemisphere. CONCLUSIONS: We found that both loss of efficiency and compensatory mechanisms occur in PD patients, providing further insight into the pathophysiological role of the functional alterations of basal ganglia and limbic structures in the impairment of visuoperceptual and visuospatial functions observed in PD.

  18. Clustered granules present in the hippocampus of aged mice result from a degenerative process affecting astrocytes and their surrounding neuropil.

    Science.gov (United States)

    Manich, Gemma; Cabezón, Itsaso; Camins, Antoni; Pallàs, Mercè; Liberski, Pawel P; Vilaplana, Jordi; Pelegrí, Carme

    2014-01-01

    Clusters of pathological granular structures appear and progressively increase in number with age in the hippocampus of several mice strains, markedly in the senescence-accelerated mouse prone 8 mice. In the present work, we performed an ultrastructural study of these granules paying special attention to the first stages of their formation, which have not been previously explored. The analysis of the immature granules allowed concluding that granules are not simple accumulations of molecular waste but the result of a degenerative process involving principally astrocytic processes, although nearby neuronal structures can be also affected. The granule generation includes the instability of the plasmatic membranes and the appearance of abnormal membranous structures that form intracellular bubbles or blebs of variable sizes and irregular shapes. These structures and some organelles degenerate producing some membranous fragments, and an assembly process of the resulting fragments generates the dense-core nucleus of the mature granule. Moreover, we found out that the neo-epitope recently described in the mature granules and localised abundantly in the membranous fragments of their dense-core nucleus emerges in the first stages of the granule formation. On the other hand, with this study, we increase the evidences that each cluster of granules is formed by the granules comprised in one astrocyte. A better knowledge of the causes of the granule formation and the function of the neo-epitope will help in both the interpretation of the physiological significance of the granules and their contribution to the degenerating processes in aging brain.

  19. Visuo-Spatial Imagery Impairment in Posterior Cortical Atrophy: A Cognitive and SPECT Study

    Directory of Open Access Journals (Sweden)

    Simona Gardini

    2011-01-01

    Full Text Available This study investigated the cognitive profile and the cerebral perfusion pattern in a highly educated 70 year old gentleman with posterior cortical atrophy (PCA. Visuo-perceptual abilities, spatial memory, spatial representation and navigation, visuo-spatial mental imagery, semantic and episodic-autobiographical memory were assessed. Regional cerebral blood flow (rCBF was imaged with SPECT. Cognitive testing showed visual-perceptual impairment, apperceptive visual and landmark agnosia, topographical disorientation with way-finding deficits, impaired map learning and poor mental image generation. Semantic memory was normal, while episodic-autobiographical memory was impaired. Reduced rCBF was found mainly in the right hemisphere, in the precentral gyrus, posterior cingulate and middle temporal gyri, cuneus and precuneus, in the left superior temporal and lingual gyri and in the parahippocampus bilaterally. Hypoperfusion in occipito-parietal regions was associated with visuo-spatial deficits, whereas deficits in visuo-spatial mental imagery might reflect dysfunction related to hypoperfusion in the parahippocampus and precuneus, structures which are responsible for spatial and imagery processing. Dissociating performance between preserved semantic memory and poor episodic-autobiographical recall is consistent with a pattern of normal perfusion in frontal and anterior temporal regions but abnormal rCBF in the parahippocampi. The present findings indicate that PCA involves visuo-spatial imagery deficits and provide further validation to current neuro-cognitive models of spatial representation and topographical disorientation.

  20. General Intelligence, Visuospatial and Verbal Abilities in Korean Children.

    Science.gov (United States)

    Lynn, Richard; Song, Myung Ja

    1994-01-01

    Nine-year olds completed measures of general intelligence, visuospatial ability, and verbal fluency. Subjects were 107 Korean children and 115 British children. Found that Korean children scored higher on general intelligence and visuospatial ability and lower on verbal fluency than British children. (BC)

  1. Visuospatial Superiority in Developmental Dyslexia: Myth or Reality?

    Science.gov (United States)

    Brunswick, Nicola; Martin, G. Neil; Marzano, Lisa

    2010-01-01

    Anecdotal evidence indicates that dyslexia is positively associated with superior visuospatial ability but empirical evidence is inconsistent. We explicitly tested the hypothesis that dyslexia is associated with visuospatial advantage in 20 dyslexic and 21 unimpaired adult readers using paper-and-pencil measures and tests of "everyday"…

  2. Phonological and Visuospatial Working Memory in Autism Spectrum Disorders

    Science.gov (United States)

    Macizo, P.; Soriano, M. F.; Paredes, N.

    2016-01-01

    We evaluated phonological and visuospatial working memory (WM) in autism spectrum disorders. Autistic children and typically developing children were compared. We used WM tasks that measured phonological and visuospatial WM up to the capacity limit of each children. Overall measures of WM did not show differences between autistic children and…

  3. Data analysis of Permanent GPS networks in Italy and surrounding region: application of a distributed processing approach

    Directory of Open Access Journals (Sweden)

    M. Anzidei

    2006-06-01

    Full Text Available We describe the procedures used to combine into a uniform velocity solution the observations of more than 80 continuous GPS stations operating in the central Mediterranean in the 1998-2004 time interval. We used a distributed processing approach, which makes efficient use of computer resources, while producing velocity estimates for all stations in one common reference frame, allowing for an effective merging of all the observations into a self-consistent network solution. We describe the CGPS data archiving and processing procedures, and provide main results in terms of position time-series and velocities for all stations that observed more than three years. We computed horizontal and vertical velocities accounting for the seasonal (annual and semi-annual signals, and considering the off-sets in the coordinate time-series caused by station equipment changes. Weighted post-fit RMS of the north, east and vertical velocity components are in the range of 1.57-2.08 mm, 1.31-3.28 mm, and 3.60-7.24 mm, respectively, which are reduced by solving for seasonal signals in the velocity estimates. The annual and semi-annual signals in the height components, with amplitudes up to 4.8 mm, are much stronger than those in the horizontal components. The mean amplitudes of annual and semi-annual signals are within 0.18-0.47 mm, 0.23-0.52 mm and 0.55-1.92 mm in the north, east and vertical components, respectively.

  4. Attentional networks and visuospatial working memory capacity in social anxiety.

    Science.gov (United States)

    Moriya, Jun

    2016-12-02

    Social anxiety is associated with attentional bias and working memory for emotional stimuli; however, the ways in which social anxiety affects cognitive functions involving non-emotional stimuli remains unclear. The present study focused on the role of attentional networks (i.e. alerting, orienting, and executive control networks) and visuospatial working memory capacity (WMC) for non-emotional stimuli in the context of social anxiety. One hundred and seventeen undergraduates completed questionnaires on social anxiety. They then performed an attentional network test and a change detection task to measure visuospatial WMC. Orienting network and visuospatial WMC were positively correlated with social anxiety. A multiple regression analysis showed significant positive associations of alerting, orienting, and visuospatial WMC with social anxiety. Alerting, orienting networks, and high visuospatial WMC for non-emotional stimuli may predict degree of social anxiety.

  5. Visuospatial selective attention in chickens.

    Science.gov (United States)

    Sridharan, Devarajan; Ramamurthy, Deepa L; Schwarz, Jason S; Knudsen, Eric I

    2014-05-13

    Voluntary control of attention promotes intelligent, adaptive behaviors by enabling the selective processing of information that is most relevant for making decisions. Despite extensive research on attention in primates, the capacity for selective attention in nonprimate species has never been quantified. Here we demonstrate selective attention in chickens by applying protocols that have been used to characterize visual spatial attention in primates. Chickens were trained to localize and report the vertical position of a target in the presence of task-relevant distracters. A spatial cue, the location of which varied across individual trials, indicated the horizontal, but not vertical, position of the upcoming target. Spatial cueing improved localization performance: accuracy (d') increased and reaction times decreased in a space-specific manner. Distracters severely impaired perceptual performance, and this impairment was greatly reduced by spatial cueing. Signal detection analysis with an "indecision" model demonstrated that spatial cueing significantly increased choice certainty in localizing targets. By contrast, error-aversion certainty (certainty of not making an error) remained essentially constant across cueing protocols, target contrasts, and individuals. The results show that chickens shift spatial attention rapidly and dynamically, following principles of stimulus selection that closely parallel those documented in primates. The findings suggest that the mechanisms that control attention have been conserved through evolution, and establish chickens--a highly visual species that is easily trained and amenable to cutting-edge experimental technologies--as an attractive model for linking behavior to neural mechanisms of selective attention.

  6. Perlecan/Hspg2 deficiency alters the pericellular space of the lacunocanalicular system surrounding osteocytic processes in cortical bone.

    Science.gov (United States)

    Thompson, William R; Modla, Shannon; Grindel, Brian J; Czymmek, Kirk J; Kirn-Safran, Catherine B; Wang, Liyun; Duncan, Randall L; Farach-Carson, Mary C

    2011-03-01

    Osteocytes project long, slender processes throughout the mineralized matrix of bone, where they connect and communicate with effector cells. The interconnected cellular projections form the functional lacunocanalicular system, allowing fluid to pass for cell-to-cell communication and nutrient and waste exchange. Prevention of mineralization in the pericellular space of the lacunocanalicular pericellular space is crucial for uninhibited interstitial fluid movement. Factors contributing to the ability of the pericellular space of the lacunocanalicular system to remain open and unmineralized are unclear. Immunofluorescence and immunogold localization by transmission electron microscopy demonstrated perlecan/Hspg2 signal localized to the osteocyte lacunocanalicular system of cortical bone, and this proteoglycan was found in the pericellular space of the lacunocanalicular system. In this study we examined osteocyte lacunocanalicular morphology in mice deficient in the large heparan sulfate proteoglycan perlecan/Hspg2 in this tissue. Ultrastructural measurements with electron microscopy of perlecan/Hspg2-deficient mice demonstrated diminished osteocyte canalicular pericellular area, resulting from a reduction in the total canalicular area. Additionally, perlecan/Hspg2-deficient mice showed decreased canalicular density and a reduced number of transverse tethering elements per canaliculus. These data indicated that perlecan/Hspg2 contributed to the integrity of the osteocyte lacunocanalicular system by maintaining the size of the pericellular space, an essential task to promote uninhibited interstitial fluid movement in this mechanosensitive environment. This work thus identified a new barrier function for perlecan/Hspg2 in murine cortical bone.

  7. Learning geometry and visuo-spatial abilities through coding

    Directory of Open Access Journals (Sweden)

    Martina Sabatini

    2016-04-01

    Full Text Available This paper deals with the theme of coding, focusing particularly on its introduction in a specific primary school curriculum. The work presents the PhD research project “Learning geometry and visuo-spatial abilities through coding”. The project, which is not yet concluded, aims to reflect on the possibility of introducing coding activities within the primary school curricula of geometry of third graders, in order to study if and how these activities affect learning geometry and visuo-spatial abilities. To do so, the processes of teaching and learning of experimental classes (those in which coding activities take place and control classes (those in which coding activities do not take place will be compared, both in terms of quantity and quality. The classes has been chosen according to a uniformity requirement with respect to the starting points of geometrical knowledge and visuo-spatial abilities. L’apprendimento di conoscenze geometriche e abilità visuo-spaziali attraverso il codingIl presente lavoro affronta la tematica del coding focalizzandosi in particolar modo sulla sua introduzione in uno specifico curricolo di scuola primaria. Viene presentato il progetto di ricerca di dottorato “L’apprendimento di conoscenze geometriche e abilità visuo-spaziali attraverso il coding”. Il progetto, non ancora concluso, intende riflettere sulla possibilità di introdurre attività di coding all’interno dei curricoli di geometria delle classi terze di scuola primaria, al fine di studiare se e come questo tipo di attività influisca sull’acquisizione di apprendimenti geometrici e abilità visuo-spaziali. Per farlo, verranno confrontati, sia in termini quantitativi che qualitativi, i processi di insegnamento-apprendimento di classi sperimentali (quelle in cui avvengono attività di coding e di classi di controllo (quelle in cui non avvengono attività di coding. Le classi sono state scelte secondo un criterio di omogeneità relativamente

  8. Forcing functions governing salt transport processes in coastal navigation canals and connectivity to surrounding marshes in South Louisiana using Houma Navigation Canal as a surrogate

    Science.gov (United States)

    Snedden, Gregg

    2014-01-01

    Understanding how circulation and mixing processes in coastal navigation canals influence the exchange of salt between marshes and coastal ocean, and how those processes are modulated by external physical processes, is critical to anticipating effects of future actions and circumstance. Examples of such circumstances include deepening the channel, placement of locks in the channel, changes in freshwater discharge down the channel, changes in outer continental shelf (OCS) vessel traffic volume, and sea level rise. The study builds on previous BOEM-funded studies by investigating salt flux variability through the Houma Navigation Canal (HNC). It examines how external physical factors, such as buoyancy forcing and mixing from tidal stirring and OCS vessel wakes, influence dispersive and advective fluxes through the HNC and the impact of this salt flux on salinity in nearby marshes. This study quantifies salt transport processes and salinity variability in the HNC and surrounding Terrebonne marshes. Data collected for this study include time-series data of salinity and velocity in the HNC, monthly salinity-depth profiles along the length of the channel, hourly vertical profiles of velocity and salinity over multiple tidal cycles, and salinity time series data at three locations in the surrounding marshes along a transect of increasing distance from the HNC. Two modes of vertical current structure were identified. The first mode, making up 90% of the total flow field variability, strongly resembled a barotropic current structure and was coherent with alongshelf wind stress over the coastal Gulf of Mexico. The second mode was indicative of gravitational circulation and was linked to variability in tidal stirring and the longitudinal salinity gradients along the channel’s length. Diffusive process were dominant drivers of upestuary salt transport, except during periods of minimal tidal stirring when gravitational circulation became more important. Salinity in the

  9. The Use of the Target Cancellation Task to Identify Eloquent Visuospatial Regions in Awake Craniotomies: Technical Note.

    Science.gov (United States)

    Conner, Andrew K; Glenn, Chad; Burks, Joshua D; McCoy, Tressie; Bonney, Phillip A; Chema, Ahmed A; Case, Justin L; Brunner, Scott; Baker, Cordell; Sughrue, Michael

    2016-11-17

    The success of awake craniotomies relies on the patient's performance of function-specific tasks that are simple, quick, and reproducible. Intraoperative identification of visuospatial function through cortical and subcortical mapping has utilized a variety of intraoperative tests, each with its own benefits and drawbacks. In light of this, we developed a simple software program that aids in preventing neglect by simulating a target-cancellation task on a portable electronic device. In this report, we describe the interactive target cancellation task and have reviewed seven consecutive patients who underwent awake craniotomy for parietal and/or posterior temporal infiltrating brain tumors of the non-dominant hemisphere. Each of these patients performed target cancellation and line bisection tasks intraoperatively. The outcomes of each patient and testing scenario are described. Positive intraoperative cortical and subcortical sites involved with visuospatial processing were identified in three of the seven patients using the target cancellation and confirmed utilizing the line-bisection task. No identification of visuospatial function was accomplished utilizing the line-bisection task alone. Complete visuospatial function mapping was completed in less than 10 minutes in all patients. No patients had preoperative or postoperative hemineglect. Our findings highlight the feasibility of the target cancellation technique for use during awake craniotomy to aid in avoiding postoperative hemineglect. Target cancellation may offer an alternative method of cortical and subcortical visuospatial mapping in patients unable to perform other commonly used modalities.

  10. The relative roles of visuospatial and linguistic working memory systems in generating inferences during visual narrative comprehension.

    Science.gov (United States)

    Magliano, Joseph P; Larson, Adam M; Higgs, Karyn; Loschky, Lester C

    2016-02-01

    This study investigated the relative roles of visuospatial versus linguistic working memory (WM) systems in the online generation of bridging inferences while viewers comprehend visual narratives. We contrasted these relative roles in the visuospatial primacy hypothesis versus the shared (visuospatial & linguistic) systems hypothesis, and tested them in 3 experiments. Participants viewed picture stories containing multiple target episodes consisting of a beginning state, a bridging event, and an end state, respectively, and the presence of the bridging event was manipulated. When absent, viewers had to infer the bridging-event action to comprehend the end-state image. A pilot study showed that after viewing the end-state image, participants' think-aloud protocols contained more inferred actions when the bridging event was absent than when it was present. Likewise, Experiment 1 found longer viewing times for the end-state image when the bridging-event image was absent, consistent with viewing times revealing online inference generation processes. Experiment 2 showed that both linguistic and visuospatial WM loads attenuated the inference viewing time effect, consistent with the shared systems hypothesis. Importantly, however, Experiment 3 found that articulatory suppression did not attenuate the inference viewing time effect, indicating that (sub)vocalization did not support online inference generation during visual narrative comprehension. Thus, the results support a shared-systems hypothesis in which both visuospatial and linguistic WM systems support inference generation in visual narratives, with the linguistic WM system operating at a deeper level than (sub)vocalization.

  11. Linking empathy to visuospatial perspective-taking in gambling addiction.

    Science.gov (United States)

    Tomei, Alexander; Besson, Jacques; Grivel, Jeremy

    2017-04-01

    It has been demonstrated that people suffering from substance-related addictions are less empathic than their non-addicted counterparts. Our first aim was to verify if this is also true for behavioral addictions. We hypothesized that problem gamblers are less empathic than healthy controls. Our second aim was to identify a cognitive marker of empathy that could be targeted in cognitive rehabilitation strategies. We propose that a potential cognitive marker of empathy could be visuospatial perspective-taking. Specifically, we hypothesized that visuospatial perspective-taking performances are lower in problem gamblers compared to healthy controls and that these visuospatial performances predict empathy. Thirty-one non-gamblers, 24 healthy gamblers, and 21 problem gamblers performed a visuospatial perspective-taking task before completing the Interpersonal Reactivity Index (IRI; Davis, 1980; Davis, 1983). Problem gamblers had decreased empathy and lower performance at the visuospatial perspective-taking task than non-gamblers and healthy gamblers. Furthermore, we confirmed that visuospatial perspective-taking abilities predict empathy on the IRI dimensions of interpersonal perspective-taking and personal distress. The present study provides new evidence that reduced empathy is not limited to subjects with substance-related addictions; rather, it extends to behavioral addictions. Visuospatial perspective-taking may be a viable cognitive marker for use as a rehabilitation target of empathy.

  12. Visuospatial memory and neuroimaging correlates in mild cognitive impairment.

    Science.gov (United States)

    Mitolo, Micaela; Gardini, Simona; Fasano, Fabrizio; Crisi, Girolamo; Pelosi, Annalisa; Pazzaglia, Francesca; Caffarra, Paolo

    2013-01-01

    Spatial abilities decline in normal aging and decrease faster and earlier in Alzheimer's disease (AD), but these deficits are under investigated. The main goals of this study were to assess visuospatial memory abilities in mild cognitive impairment (MCI), in order to verify whether these tasks might be valid as the standard cognitive test to differentiate MCI individuals from normal controls and to investigate the brain structural correlates of visuospatial deficits. Twenty MCI patients and fourteen healthy elderly controls underwent an experimental visuospatial battery, which also included self-rating spatial questionnaires, and structural MRI brain imaging. Compared to healthy elderly controls, MCI patients scored significantly worse in almost all visuospatial tasks. ROC analysis showed that visuospatial tasks had an elevated discriminant power between groups (AUC >0.90). Voxel-based morphometry analysis, compared to controls, disclosed a higher level of atrophy in frontal and medio-temporal regions and a different pattern of correlation between grey matter values and visuospatial performance, with wider distributed areas of the occipital and middle temporal cortex in the map and route learning. This study indicates that visuospatial memory tests are valid tools in completing the diagnostic evaluation of MCI.

  13. 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.

  14. Visual surround suppression in schizophrenia

    Directory of Open Access Journals (Sweden)

    Marc Samuel Tibber

    2013-02-01

    Full Text Available Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with schizophrenia demonstrated weaker surround suppression compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation surround suppression in schizophrenia may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies.

  15. Reading direction shifts visuospatial attention: an Interactive Account of attentional biases.

    Science.gov (United States)

    Rinaldi, Luca; Di Luca, Samuel; Henik, Avishai; Girelli, Luisa

    2014-09-01

    A growing amount of evidence confirms the influence of reading and writing habits on visuospatial processing, although this phenomenon has been so far testified mainly as a lateralized shift of a single behavioral sign (e.g., line bisection), with lack of proof from pure right-to-left readers. The present study contributed to this issue by analyzing multiple attentional and motor indexes in monolingual Italian (i.e., reading from left-to-right), and monolingual (i.e., reading from right-to-left) and bilingual Israeli (i.e., reading from right-to-left in Hebrew but also from left-to-right in English) participants' visuospatial performance. Subjects were administered a computerized standard star cancellation task and a modified version in which English letters and words were replaced by Hebrew ones. Tasks were presented on a graphics tablet, allowing recording of both chronometric and spatial parameters (i.e., measured in (x, y) vector coordinates). Results showed that reading direction modulated the on-line visuomotor performance (i.e., left-to-right vs. right-to-left shifts) from the beginning (i.e., first mark) to the end of the task (i.e., spatial distribution of omissions and subjective epicenter). Additionally, the spatial bias observed in a computerized line bisection task was also related to the participants' habitual reading direction. Overall, the results favor the proposal of an Interactive Account of visuospatial asymmetries, according to which both cultural factors, such as the directional scanning associated with language processing, and biological factors, such as hemispheric specialization, modulate visuospatial processing. Results are discussed in light of recent behavioral and neuroanatomical findings.

  16. Visuospatial deficits in children 3 - 7 years old with shunted ...

    African Journals Online (AJOL)

    right parieto-occipital region and may further compound these visuospatial deficitis. ... The Absurdities A Test measures the ability to evaluate the correctness of figural information ... include hand-eye co-ordination, perceptual ability and visual-.

  17. Visuospatial dysfunction and problem solving in Parkinson's disease.

    Science.gov (United States)

    Cronin-Golomb, A; Braun, A E

    1997-01-01

    Individuals with Parkinson's disease (PD) perform deficiently on Raven's Coloured Progressive Matrices (RCPM), in contrast to their relatively good performance on many other problem-solving tasks. The question is raised as to whether a visuospatial deficit may account for poor RCPM performance in PD. The authors analyzed RCPM results in 50 nondemented participants with PD and 39 age-matched healthy control participants. The PD group made significantly more errors than the control group on all RCPM subtests, including the subtest that mainly assessed visuospatial function (RCPM-A). For the PD group, the composite score of other visuospatial tests, but not the composite scores of tests of executive function or verbal memory, significantly predicted performance on the RCPM-A. Visuospatial impairment in PD may arise from dysfunction of the basal ganglia-thalamocortical circuit that also includes the dorsolateral prefrontal cortex and, importantly, the posterior parietal lobes.

  18. Levels and distribution of methoxylated and hydroxylated polybrominated diphenyl ethers in plant and soil samples surrounding a seafood processing factory and a seafood market.

    Science.gov (United States)

    Sun, Jianteng; Liu, Jiyan; Liu, Yanwei; Jiang, Guibin

    2013-05-01

    Polybrominated diphenyl ethers (PBDEs) along with hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were found in plant and soil samples collected surrounding a seafood processing factory and a seafood market in China. The profiles of MeO-PBDE congeners were different between seafood processing factory and seafood market. The detection frequency and concentration of 6-OH-BDE-47 were lower than that of MeO-PBDEs. Near seafood processing factory, a decreasing trend of analyte concentrations in plants was found downstream the river where factory wastewater was discharged. Concentrations of ΣMeO-PBDEs in plant and soil samples showed difference as root > soil > leaf. However, at seafood market, the concentrations of ΣMeO-PBDEs were much higher in leaves than those in soil. The concentration of ΣMeO-PBDEs in leaves showed a remarkable difference between Calystegia soldanella (Linn.) R. Br. and Setaira viridis (L.) Beauv.

  19. In vivo functional neurochemistry of human cortical cholinergic function during visuospatial attention

    Science.gov (United States)

    Lindner, Michael; Bell, Tiffany; Iqbal, Somya; Mullins, Paul Gerald

    2017-01-01

    Cortical acetylcholine is involved in key cognitive processes such as visuospatial attention. Dysfunction in the cholinergic system has been described in a number of neuropsychiatric disorders. Levels of brain acetylcholine can be pharmacologically manipulated, but it is not possible to directly measure it in vivo in humans. However, key parts of its biochemical cascade in neural tissue, such as choline, can be measured using magnetic resonance spectroscopy (MRS). There is evidence that levels of choline may be an indirect but proportional measure of acetylcholine availability in brain tissue. In this study, we measured relative choline levels in the parietal cortex using functional (event-related) MRS (fMRS) during performance of a visuospatial attention task, with a modelling approach verified using simulated data. We describe a task-driven interaction effect on choline concentration, specifically driven by contralateral attention shifts. Our results suggest that choline MRS has the potential to serve as a proxy of brain acetylcholine function in humans. PMID:28192451

  20. Visuospatial reasoning and its relation to external variables

    OpenAIRE

    Juliana Carnevalli Siqueira Nery; Fabián Javier Marín Rueda

    2014-01-01

    In this study, the relation of age and sex with visuospatial reasoning assessed by the Cube Test was investigated. In addition, a comparative study was conducted between this study sample and the normative group of the test with regard to visuospatial reasoning performance results. Six hundred and eighty-four students participated in this study, from the city of Belo Horizonte (State of Minas Gerais, Brazil), aged between 15 and 57 years old, both male and female. The results showed both age ...

  1. Individual Differences in the Development of Early Writing Skills: Testing the Unique Contribution of Visuo-Spatial Working Memory

    Science.gov (United States)

    Bourke, Lorna; Davies, Simon J.; Sumner, Emma; Green, Carolyn

    2014-01-01

    Visually mediated processes including, exposure to print (e.g. reading) as well as orthographic transcription and coding skills, have been found to contribute to individual differences in literacy development. The current study examined the role of visuospatial working memory (WM) in underpinning this relationship and emergent writing. One hundred…

  2. Neuroimaging of the Functional and Structural Networks Underlying Visuospatial vs. Linguistic Reasoning in High-Functioning Autism

    Science.gov (United States)

    Sahyoun, Cherif P.; Belliveau, John W.; Soulieres, Isabelle; Schwartz, Shira; Mody, Maria

    2010-01-01

    High-functioning individuals with autism have been found to favor visuospatial processing in the face of typically poor language abilities. We aimed to examine the neurobiological basis of this difference using functional magnetic resonance imaging and diffusion tensor imaging. We compared 12 children with high functioning autism (HFA) to 12 age-…

  3. Developmental dyscalculia is related to visuo-spatial memory and inhibition impairment.

    Science.gov (United States)

    Szucs, Denes; Devine, Amy; Soltesz, Fruzsina; Nobes, Alison; Gabriel, Florence

    2013-01-01

    Developmental dyscalculia is thought to be a specific impairment of mathematics ability. Currently dominant cognitive neuroscience theories of developmental dyscalculia suggest that it originates from the impairment of the magnitude representation of the human brain, residing in the intraparietal sulcus, or from impaired connections between number symbols and the magnitude representation. However, behavioral research offers several alternative theories for developmental dyscalculia and neuro-imaging also suggests that impairments in developmental dyscalculia may be linked to disruptions of other functions of the intraparietal sulcus than the magnitude representation. Strikingly, the magnitude representation theory has never been explicitly contrasted with a range of alternatives in a systematic fashion. Here we have filled this gap by directly contrasting five alternative theories (magnitude representation, working memory, inhibition, attention and spatial processing) of developmental dyscalculia in 9-10-year-old primary school children. Participants were selected from a pool of 1004 children and took part in 16 tests and nine experiments. The dominant features of developmental dyscalculia are visuo-spatial working memory, visuo-spatial short-term memory and inhibitory function (interference suppression) impairment. We hypothesize that inhibition impairment is related to the disruption of central executive memory function. Potential problems of visuo-spatial processing and attentional function in developmental dyscalculia probably depend on short-term memory/working memory and inhibition impairments. The magnitude representation theory of developmental dyscalculia was not supported.

  4. Basic and advanced numerical performances relate to mathematical expertise but are fully mediated by visuospatial skills.

    Science.gov (United States)

    Sella, Francesco; Sader, Elie; Lolliot, Simon; Cohen Kadosh, Roi

    2016-09-01

    Recent studies have highlighted the potential role of basic numerical processing in the acquisition of numerical and mathematical competences. However, it is debated whether high-level numerical skills and mathematics depends specifically on basic numerical representations. In this study mathematicians and nonmathematicians performed a basic number line task, which required mapping positive and negative numbers on a physical horizontal line, and has been shown to correlate with more advanced numerical abilities and mathematical achievement. We found that mathematicians were more accurate compared with nonmathematicians when mapping positive, but not negative numbers, which are considered numerical primitives and cultural artifacts, respectively. Moreover, performance on positive number mapping could predict whether one is a mathematician or not, and was mediated by more advanced mathematical skills. This finding might suggest a link between basic and advanced mathematical skills. However, when we included visuospatial skills, as measured by block design subtest, the mediation analysis revealed that the relation between the performance in the number line task and the group membership was explained by non-numerical visuospatial skills. These results demonstrate that relation between basic, even specific, numerical skills and advanced mathematical achievement can be artifactual and explained by visuospatial processing. (PsycINFO Database Record

  5. Task instructions determine the visuospatial and verbal-spatial nature of number-space associations.

    Science.gov (United States)

    Georges, Carrie; Schiltz, Christine; Hoffmann, Danielle

    2015-01-01

    Evidence for number-space associations comes from the spatial-numerical association of response codes (SNARC) effect, consisting in faster reaction times to small/large digits with the left/right hand, respectively. Two different proposals are commonly discussed concerning the cognitive origin of the SNARC effect: the visuospatial account and the verbal-spatial account. Recent studies have provided evidence for the relative dominance of verbal-spatial over visuospatial coding mechanisms, when both mechanisms were directly contrasted in a magnitude comparison task. However, in these studies, participants were potentially biased towards verbal-spatial number processing by task instructions based on verbal-spatial labels. To overcome this confound and to investigate whether verbal-spatial coding mechanisms are predominantly activated irrespective of task instructions, we completed the previously used paradigm by adding a spatial instruction condition. In line with earlier findings, we could confirm the predominance of verbal-spatial number coding under verbal task instructions. However, in the spatial instruction condition, both verbal-spatial and visuospatial mechanisms were activated to an equal extent. Hence, these findings clearly indicate that the cognitive origin of number-space associations does not always predominantly rely on verbal-spatial processing mechanisms, but that the spatial code associated with numbers is context dependent.

  6. Visuospatial attention deficit in patients with local brain lesions.

    Science.gov (United States)

    Xu, Guang-Qing; Lan, Yue; Huang, Dong-Feng; Rao, De-Zhong; Pei, Zhong; Chen, Ling; Zeng, Jin-Sheng

    2010-03-31

    The disability of visuospatial attention can lead to poor volitional movement and functional recovery in patients with brain lesions. However, the accurate clinical method to assess visuospatial attention is limited. The frontoparietal network including the posterior parietal cortex and the frontal eye fields has been shown to involve in visuospatial attention. The Attention Network Test provided measures for three different components of visuospatial attention: alerting, orienting and executive control. This study was to probe the deficit and relationship of visuospatial attention using Attention Network Test paradigm in patients with frontoparietal network lesions. During this task, patients responded significantly slower on each cue condition and target type than controls, and showed deficits in the alerting and orienting networks. The efficiency of resolving conflict was decreased in patients with frontal lesions whereas this was increased in patients with parietal lesions. These findings suggest that the frontoparietal network is involved in the alerting and orienting attentional function and the executive function is possibly selectively associated with the frontal lobe. The Attention Network Test paradigm produces sensitive, valid and reliable subject estimates of visuospatial attention function in patients with brain lesions, and may be useful for clinical rehabilitation strategy selection for patients with the frontoparietal network lesions.

  7. Visuospatial memory in patients with obsessive-compulsive disorder

    Directory of Open Access Journals (Sweden)

    Anamika Sahu

    2017-01-01

    Full Text Available Background: Obsessive-compulsive disorder (OCD is a clinically heterogeneous disorder. The previous studies have been conducted to elucidate visuospatial and nonverbal memory deficits in OCD patients. However, they did not reach equivocal results which need to be replicated. Objectives: The current study examines the visuospatial memory in male patients with OCD as compared to normal healthy controls. Materials and Methods: It is a cross-sectional hospital-based study, in which 15 OCD patients and 15 age-, sex-, and education-matched normal healthy controls were chosen by purposive sampling technique. All the participants underwent the Extended Complex Figure Test (ECFT for the assessment of visuospatial memory. Results: Significant difference was found between OCD patients and normal healthy controls on various domains of ECFT. OCD patients performed poorly on copy condition (t = −4.46; P< 0.001, immediate recall (t = −5.20; P< 0.001, delayed recall (t = −5.18; P< 0.001, recognition task (P < 0.001, and matching task (P < 0.001 than the controls. Conclusion: Visuospatial memory was significantly impaired in OCD that included disturbed encoding and impaired visuospatial functioning. Hence, it is important to understand the significance of visuospatial memory in the pathophysiology for OCD diagnosis and therapeutic decision.

  8. Differential white matter involvement associated with distinct visuospatial deficits after right hemisphere stroke.

    Science.gov (United States)

    Carter, Alex R; McAvoy, Mark P; Siegel, Joshua S; Hong, Xin; Astafiev, Serguei V; Rengachary, Jennifer; Zinn, Kristi; Metcalf, Nicholas V; Shulman, Gordon L; Corbetta, Maurizio

    2017-03-01

    Visuospatial attention depends on the integration of multiple processes, and people with right hemisphere lesions after a stroke may exhibit severe or no visuospatial deficits. The anatomy of core components of visuospatial attention is an area of intense interest. Here we examine the relationship between the disruption of core components of attention and lesion distribution in a heterogeneous group (N = 70) of patients with right hemisphere strokes regardless of the presence of clinical neglect. Deficits of lateralized spatial orienting, measured as the difference in reaction times for responding to visual targets in the contralesional or ipsilesional visual field, and deficits in re-orienting attention, as measured by the difference in reaction times for invalidly versus validly cued targets, were measured using a computerized spatial orienting task. Both measures were related through logistic regression and a novel ridge regression method to anatomical damage measured with magnetic resonance imaging. While many regions were common to both deficit maps, a deficit in lateralized spatial orienting was more associated with lesions in the white matter underlying the posterior parietal cortex, and middle and inferior frontal gyri. A deficit in re-orienting of attention toward unattended locations was associated with lesions in the white matter of the posterior parietal cortex, insular cortex and less so with white matter involvement of the anterior frontal lobe. An hodological analysis also supports this partial dissociation between the white matter tracts that are damaged in lateralized spatial biases versus impaired re-orienting. Our results underscore that the integrity of fronto-parietal white matter tracts is crucial for visuospatial attention and that different attention components are mediated by partially distinct neuronal substrates.

  9. Attention enhances the retrieval and stability of visuospatial and olfactory representations in the dorsal hippocampus.

    Directory of Open Access Journals (Sweden)

    Isabel A Muzzio

    2009-06-01

    Full Text Available A key question in the analysis of hippocampal memory relates to how attention modulates the encoding and long-term retrieval of spatial and nonspatial representations in this region. To address this question, we recorded from single cells over a period of 5 days in the CA1 region of the dorsal hippocampus while mice acquired one of two goal-oriented tasks. These tasks required the animals to find a hidden food reward by attending to either the visuospatial environment or a particular odor presented in shifting spatial locations. Attention to the visuospatial environment increased the stability of visuospatial representations and phase locking to gamma oscillations--a form of neuronal synchronization thought to underlie the attentional mechanism necessary for processing task-relevant information. Attention to a spatially shifting olfactory cue compromised the stability of place fields and increased the stability of reward-associated odor representations, which were most consistently retrieved during periods of sniffing and digging when animals were restricted to the cup locations. Together, these results suggest that attention selectively modulates the encoding and retrieval of hippocampal representations by enhancing physiological responses to task-relevant information.

  10. Exceptional visuospatial imagery in schizophrenia; implications for madness and creativity

    Directory of Open Access Journals (Sweden)

    Taylor eBenson

    2013-11-01

    Full Text Available Biographical and historical accounts suggest a link between scientific creativity and schizophrenia. Longitudinal studies of gifted children indicate that visuospatial imagery plays a pivotal role in exceptional achievements in science and mathematics. We asked whether visuospatial imagery is enhanced in individuals with schizophrenia (SZ. We compared SZ and matched healthy controls (HC on five visuospatial tasks tapping parietal and frontoparietal functions. Two aspects of visuospatial transformation, spatial location and mental imagery manipulation were examined with Paper Folding Test and Jigsaw Puzzle Task, respectively. Visuospatial intelligence was assessed with Ravens Progressive Matrices, which is associated with frontoparietal network activity. Hemispatial inattention implicating parietal function was assessed with line bisection task. Mediated by prefrontal cortex, spatial delayed response task was used to index working memory maintenance, which was impaired in SZ compared to HC. In contrast, SZ showed intact visuospatial intelligence and transformation of location. Further, SZ performed significantly better than HC on jigsaw puzzle task indicating enhanced mental imagery manipulation. Spatial working memory maintenance and mental imagery manipulation were strongly associated in HC but dissociated in SZ. Thus, we observed enhanced mental imagery manipulation in SZ but the dissociation of mental imagery from working memory suggests a disrupted frontoparietal network. Finally, while HC showed the expected leftward pseudoneglect, SZ showed increased rightward line bisection bias implicating left hemispatial inattention and impaired right parietal control of spatial attention. The current results chart a unique profile of impaired, spared and enhanced parietal-mediated visuospatial functions implicating parietal abnormalities as a biobehavioral marker for SZ. We discuss these results in relation to creative cognition.

  11. Exceptional visuospatial imagery in schizophrenia; implications for madness and creativity.

    Science.gov (United States)

    Benson, Taylor L; Park, Sohee

    2013-01-01

    Biographical and historical accounts suggest a link between scientific creativity and schizophrenia. Longitudinal studies of gifted children indicate that visuospatial imagery plays a pivotal role in exceptional achievements in science and mathematics. We asked whether visuospatial imagery is enhanced in individuals with schizophrenia (SZ). We compared SZ and matched healthy controls (HC) on five visuospatial tasks tapping parietal and frontoparietal functions. Two aspects of visuospatial transformation, spatial location and mental imagery manipulation were examined with Paper Folding Test (PFT) and jigsaw puzzle task (JPT), respectively. Visuospatial intelligence was assessed with Ravens Progressive Matrices, which is associated with frontoparietal network activity. Hemispatial inattention implicating parietal function was assessed with line bisection (LB) task. Mediated by prefrontal cortex, spatial delayed response task (DRT) was used to index working memory maintenance, which was impaired in SZ compared to HC. In contrast, SZ showed intact visuospatial intelligence and transformation of location. Further, SZ performed significantly better than HC on JPT indicating enhanced mental imagery manipulation. Spatial working memory (SWM) maintenance and mental imagery manipulation were strongly associated in HC but dissociated in SZ. Thus, we observed enhanced mental imagery manipulation in SZ but the dissociation of mental imagery from working memory suggests a disrupted frontoparietal network. Finally, while HC showed the expected leftward pseudoneglect, SZ showed increased rightward LB bias implicating left hemispatial inattention and impaired right parietal control of spatial attention. The current results chart a unique profile of impaired, spared and enhanced parietal-mediated visuospatial functions implicating parietal abnormalities as a biobehavioral marker for SZ. We discuss these results in relation to creative cognition.

  12. Processing the Bouguer anomaly map of Biga and the surrounding area by the cellular neural network: application to the southwestern Marmara region

    Science.gov (United States)

    Aydogan, D.

    2007-04-01

    An image processing technique called the cellular neural network (CNN) approach is used in this study to locate geological features giving rise to gravity anomalies such as faults or the boundary of two geologic zones. CNN is a stochastic image processing technique based on template optimization using the neighborhood relationships of cells. These cells can be characterized by a functional block diagram that is typical of neural network theory. The functionality of CNN is described in its entirety by a number of small matrices (A, B and I) called the cloning template. CNN can also be considered to be a nonlinear convolution of these matrices. This template describes the strength of the nearest neighbor interconnections in the network. The recurrent perceptron learning algorithm (RPLA) is used in optimization of cloning template. The CNN and standard Canny algorithms were first tested on two sets of synthetic gravity data with the aim of checking the reliability of the proposed approach. The CNN method was compared with classical derivative techniques by applying the cross-correlation method (CC) to the same anomaly map as this latter approach can detect some features that are difficult to identify on the Bouguer anomaly maps. This approach was then applied to the Bouguer anomaly map of Biga and its surrounding area, in Turkey. Structural features in the area between Bandirma, Biga, Yenice and Gonen in the southwest Marmara region are investigated by applying the CNN and CC to the Bouguer anomaly map. Faults identified by these algorithms are generally in accordance with previously mapped surface faults. These examples show that the geologic boundaries can be detected from Bouguer anomaly maps using the cloning template approach. A visual evaluation of the outputs of the CNN and CC approaches is carried out, and the results are compared with each other. This approach provides quantitative solutions based on just a few assumptions, which makes the method more

  13. Decoding covert shifts of attention induced by ambiguous visuospatial cues

    Directory of Open Access Journals (Sweden)

    Romain eTrachel

    2015-06-01

    Full Text Available Simple and unambiguous visual cues (e.g. an arrow can be used to trigger covert shifts of visual attention away from the center of gaze. The processing of visual stimuli is enhanced at the attended location. Covert shifts of attention modulate the power of cerebral oscillations in the alpha band over parietal and occipital regions. These modulations are sufficiently robust to be decoded on a single trial basis from electro-encephalography (EEG signals. It is often assumed that covert attention shifts are under voluntary control, and also occur in more natural and complex environments, but there is no direct evidence to support this assumption. We address this important issue by using random-dot stimuli to cue one of two opposite locations, where a visual target is presented. We contrast two conditions in which the random-dot motion is either predictive of the target location or contains ambiguous information. Behavioral results show attention shifts in anticipation of the visual target, in both conditions. In addition, these attention shifts involve similar neural sources, and the EEG can be decoded on a single trial basis. These results shed a new light on the behavioral and neural correlates of visuospatial attention, with implications for Brain-Computer Interfaces (BCI based on covert attention shifts.

  14. Age-related effects on verbal and visuospatial memory are mediated by theta and alpha II rhythms.

    Science.gov (United States)

    Reichert, Johanna Louise; Kober, Silvia Erika; Witte, Matthias; Neuper, Christa; Wood, Guilherme

    2016-01-01

    Both electrical brain activity during rest and memory functions change across the lifespan. Moreover, electrical brain activity is associated with memory functions. However, the interplay between all these effects has been investigated only scarcely. The present study investigated the extent to which the power of resting-state electroencephalographic (EEG) frequencies mediates the impact of aging on verbal and visuospatial memory. Seventy healthy participants with 22 to 83years of age completed a visuospatial and verbal learning and memory test and provided eyes-open and eyes-closed resting-state EEG data. Robust age-related effects on behavioral and EEG data were observed. Mediation analyses showed that the relative power of the theta (4-8Hz) frequency band in fronto-central locations partly explained the negative age-related effect on delayed recall in the verbal memory task. The relative power of the alpha II (10-12Hz) frequency band in mainly parietal locations partly explained the negative impact of age on immediate and delayed recall in the visuospatial task. Results indicate that spontaneous brain activity carries specific information about aging processes and predicts the level of competence in verbal and visuospatial memory tasks.

  15. Children's visuospatial memory predicts mathematics achievement through early adolescence.

    Science.gov (United States)

    Li, Yaoran; Geary, David C

    2017-01-01

    A previous study showed that gains in visuospatial memory from first to fifth grade predicted end-of-fifth grade mathematics but not reading achievement, controlling other factors. In this follow up study, these relations were assessed from sixth to ninth grade, inclusive (n = 145). The results showed that growth in visuospatial memory across the elementary school years was related to growth in mathematics achievement after fifth grade, controlling intelligence, the central executive and phonological memory components of working memory, in-class attentive behavior, parental education, and fifth grade mathematics achievement. As found for fifth grade, this relation was not found for reading achievement after fifth grade. In total, the results suggest that visuospatial memory has a unique influence on ease of learning some types of mathematics and that this influence becomes more important across successive grades.

  16. Visuospatial attention and motor skills in kung fu athletes.

    Science.gov (United States)

    Muiños, Mónica; Ballesteros, Soledad

    2013-01-01

    The present study compared the performance of a group of sixteen kung fu athletes with that of a control group of fourteen nonathletes on a speeded visuospatial task and a hand-tapping motor task. In the visuospatial task the results showed that athletes were faster than the control participants when stimuli were presented at the periphery of the visual field at a middle and high presentation speed with short interstimulus intervals. Athletes were also significantly faster than nonathlete participants when performing motor actions such as hand-tapping with their dominant hand but groups did not differ with the nondominant hand. These results support the view that athletes perform some speeded visuospatial and motor tasks faster than nonathletes under certain conditions. The findings suggest that, after several years of practice, kung fu athletes develop certain skills that allow them to perform motor speed maneuvers under time pressure conditions.

  17. The Neurocognitive Performance of Visuospatial Attention in Children with Obesity.

    Science.gov (United States)

    Tsai, Chia-Liang; Chen, Fu-Chen; Pan, Chien-Yu; Tseng, Yu-Ting

    2016-01-01

    The present study investigates the behavioral performance and event-related potentials (ERPs) in children with obesity and healthy weight children when performing a visuospatial attention task. Twenty-six children with obesity (obese group) and 26 healthy weight children (control group) were recruited. Their behavioral performance during a variant of the Posner paradigm was measured, and brain ERPs were recorded concurrently. The behavioral data revealed that the obese group responded more slowly, especially in the invalid condition, and exhibited a deficit in attentional inhibition capacity as compared to the control group. In terms of cognitive electrophysiological performance, although the obese group did not show significant differences on P3 latency elicited by the target stimuli when compared to the control group, they exhibited smaller P3 amplitudes when performing the visuospatial attention task. These results broaden previous findings, and indicate that childhood obesity is associated with a reduced ability to modulate the executive function network which supports visuospatial attention.

  18. Visuospatial reasoning and its relation to external variables

    Directory of Open Access Journals (Sweden)

    Juliana Carnevalli Siqueira Nery

    2014-05-01

    Full Text Available In this study, the relation of age and sex with visuospatial reasoning assessed by the Cube Test was investigated. In addition, a comparative study was conducted between this study sample and the normative group of the test with regard to visuospatial reasoning performance results. Six hundred and eighty-four students participated in this study, from the city of Belo Horizonte (State of Minas Gerais, Brazil, aged between 15 and 57 years old, both male and female. The results showed both age and sex differences, where younger students showed a significantly higher performance than older students and men showed significantly higher averages than women in every test comparison. In the study with the normative sample, men showed higher averages than women throughout every age group and in the overall result of both studies. The results obtained reflect those found in the literature and highlight the influence of age and sex on visuospatial reasoning.

  19. Visuospatial characteristics of an elderly Chinese population: results from the WAIS-R block design test

    OpenAIRE

    Yin, Shufei; Zhu, Xinyi; Huang, Xin; Li, Juan

    2015-01-01

    Visuospatial deficits have long been recognized as a potential predictor of dementia, with visuospatial ability decline having been found to accelerate in later stages of dementia. We, therefore, believe that the visuospatial performance of patients with mild cognitive impairment (MCI) and dementia (Dem) might change with varying visuospatial task difficulties. This study administered the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Block Design Test (BDT) to determine whether visuospat...

  20. Sex differences in factorial dimension of verbal, logical, mathematical and visuospatial ability.

    Science.gov (United States)

    Wormack, L

    1980-04-01

    The factor structure of verbal, logical, visuospatial, and mathematical ability was compared for responses from 52 male and 54 female college students. Separate verbal, quantitative, and visuospatial factors were isolated among males while compound verbal-mathematical-visuospatial and verbal-logical-field dependence factors were isolated among females. The data supported the hypothesis of sex-related differences in the factorial organization of verbal, mathematical, reading, writing, and visuospatial ability.

  1. ADHD Subtype Differences in Reinforcement Sensitivity and Visuospatial Working Memory.

    Science.gov (United States)

    Dovis, Sebastiaan; Van der Oord, Saskia; Wiers, Reinout W; Prins, Pier J M

    2015-01-01

    Both cognitive and motivational deficits are thought to give rise to the problems in the combined (ADHD-C) and inattentive subtype (ADHD-I) of attention-deficit hyperactivity disorder (ADHD). In both subtypes one of the most prominent cognitive weaknesses appears to be in visuospatial working memory (WM), which is composed of short-term memory (STM) and a central executive (CE). In children with ADHD-C, both STM and the CE seem impaired, and together with motivational impairments, give rise to their deficits in visuospatial WM. In children with ADHD-I, no studies investigated these WM components and their interplay with motivational impairments. Effects of a standard (feedback only) and a high level of reinforcement (feedback + 10 euros) on visuospatial WM-, STM-, and CE performance were examined in 27 children with ADHD-I (restrictive-subtype), 70 children with ADHD-C, and 40 typically developing controls (aged 9-12). In both ADHD-subtypes CE and WM performance was worse than in controls. STM performance of children with ADHD-I was, in contrast to that of children with ADHD-C, not different from controls. STM and WM performance was worse in ADHD-C than in ADHD-I, whereas CE-related performance did not differ. High reinforcement improved STM and WM performance in both subtypes but not in controls. This improvement was equally pronounced in both subtypes. High reinforcement did not improve CE-related performance. Both subtypes have equally pronounced motivational deficits, which have detrimental effects on their visuospatial STM and WM performance. In contrast to children with ADHD-C, children with ADHD-I seem unimpaired on visuospatial STM; only an impaired CE and motivational impairments give rise to their deficits in visuospatial WM.

  2. Visuospatial working memory in specific language impairment: A meta-analysis

    NARCIS (Netherlands)

    Vugs, B.A.M.; Cuperus, J.M.; Hendriks, M.P.H.; Verhoeven, L.T.W.

    2013-01-01

    We conducted a meta-analysis of the data from studies comparing visuospatial working memory (WM) in children with specific language impairment (SLI) and typically developing (TD) children. The effect sizes of 21 studies (including 32 visuospatial storage tasks and 9 visuospatial central executive (C

  3. Practices Surrounding Event Photos

    NARCIS (Netherlands)

    Vyas, Dhaval; Nijholt, Antinus; van der Veer, Gerrit C.; Kotzé, P.; Marsden, G.; Lindgaard, G.; Wesson, J.; Winckler, M.

    Sharing photos through mobile devices has a great potential for creating shared experiences of social events between co-located as well as remote participants. In order to design novel event sharing tools, we need to develop indepth understanding of current practices surrounding these so called

  4. Experiences during the decontamination process of areas surrounding to Fukushima; Experiencias durante el proceso de descontaminacion de areas aledanas a Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Molina, G., E-mail: gustavo.molina@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    In this work the experience gained during the decontamination of areas surrounding to Fukushima NPP, rugged during the earthquake and tsunami in 2011 and caused the contamination with fission products in these areas is described. Actions taken by the Japanese government are reported and some of the techniques used, the intervention levels and the progress made and disposal techniques considered are presented. (Author)

  5. Visuo-spatial cueing in children with differential reading and spelling profiles.

    Science.gov (United States)

    Banfi, Chiara; Kemény, Ferenc; Gangl, Melanie; Schulte-Körne, Gerd; Moll, Kristina; Landerl, Karin

    2017-01-01

    Dyslexia has been claimed to be causally related to deficits in visuo-spatial attention. In particular, inefficient shifting of visual attention during spatial cueing paradigms is assumed to be associated with problems in graphemic parsing during sublexical reading. The current study investigated visuo-spatial attention performance in an exogenous cueing paradigm in a large sample (N = 191) of third and fourth graders with different reading and spelling profiles (controls, isolated reading deficit, isolated spelling deficit, combined deficit in reading and spelling). Once individual variability in reaction times was taken into account by means of z-transformation, a cueing deficit (i.e. no significant difference between valid and invalid trials) was found for children with combined deficits in reading and spelling. However, poor readers without spelling problems showed a cueing effect comparable to controls, but exhibited a particularly strong right-over-left advantage (position effect). Isolated poor spellers showed a significant cueing effect, but no position effect. While we replicated earlier findings of a reduced cueing effect among poor nonword readers (indicating deficits in sublexical processing), we also found a reduced cueing effect among children with particularly poor orthographic spelling (indicating deficits in lexical processing). Thus, earlier claims of a specific association with nonword reading could not be confirmed. Controlling for ADHD-symptoms reported in a parental questionnaire did not impact on the statistical analysis, indicating that cueing deficits are not caused by more general attentional limitations. Between 31 and 48% of participants in the three reading and/or spelling deficit groups as well as 32% of the control group showed reduced spatial cueing. These findings indicate a significant, but moderate association between certain aspects of visuo-spatial attention and subcomponents of written language processing, the causal status of

  6. Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning

    Directory of Open Access Journals (Sweden)

    Jan-Maarten Luursema

    2017-01-01

    Full Text Available A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F(1=5.63 and p=.02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items.

  7. ADHD subtype differences in reinforcement sensitivity and visuospatial working memory

    NARCIS (Netherlands)

    Dovis, S.; van der Oord, S.; Wiers, R.W.; Prins, P.J.M.

    2015-01-01

    Both cognitive and motivational deficits are thought to give rise to the problems in the combined (ADHD-C) and inattentive subtype (ADHD-I) of attention-deficit hyperactivity disorder (ADHD). In both subtypes one of the most prominent cognitive weaknesses appears to be in visuospatial working memory

  8. The selective impact of chocolate craving on visuospatial working memory.

    Science.gov (United States)

    Tiggemann, Marika; Kemps, Eva; Parnell, Jasmin

    2010-08-01

    The present study aimed to extend previous research into cognitive impairments as a consequence of food craving. In particular, the study examined the impact of chocolate craving on the three components of working memory: the phonological loop, the visuospatial sketchpad, and the central executive, assessed by the digit span, Corsi blocks, and the double span tasks, respectively. A sample of 96 female undergraduate students was randomly assigned to a craving or control condition. Participants in the craving condition abstained from eating chocolate for 24h prior to testing, and performed the cognitive tasks in the presence of chocolate, a manipulation that successfully elicited chocolate cravings. As predicted on the basis of the visual imagery nature of food cravings, participants in the craving condition performed more poorly on the Corsi blocks task than control participants, but the groups did not differ on the digit span or double span measures. These results indicate that chocolate cravings selectively disrupt performance on visuospatial tasks. According to the working memory model, this occurs because food cravings compete for limited visuospatial working memory resources. These findings have practical implications in that visuospatial memory plays an important role in many everyday behaviours.

  9. Visuo-Spatial Performance in Autism: A Meta-Analysis

    Science.gov (United States)

    Muth, Anne; Hönekopp, Johannes; Falter, Christine M.

    2014-01-01

    Visuo-spatial skills are believed to be enhanced in autism spectrum disorders (ASDs). This meta-analysis tests the current state of evidence for Figure Disembedding, Block Design, Mental Rotation and Navon tasks in ASD and neurotypicals. Block Design (d = 0.32) and Figure Disembedding (d = 0.26) showed superior performance for ASD with large…

  10. Decoding the Locus of Covert Visuospatial Attention from EEG Signals.

    Science.gov (United States)

    Thiery, Thomas; Lajnef, Tarek; Jerbi, Karim; Arguin, Martin; Aubin, Mercedes; Jolicoeur, Pierre

    2016-01-01

    Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM) and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA). We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p visuospatial attention decoding and future paths for research are proposed.

  11. Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning.

    Science.gov (United States)

    Luursema, Jan-Maarten; Vorstenbosch, Marc; Kooloos, Jan

    2017-01-01

    A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual reality; one group studied those structures in virtual reality without stereoptic depth. The control group experienced an unrelated virtual reality environment. A post hoc questionnaire explored cognitive load and problem solving strategies of the participants. We found no effect of condition on learning. Visuospatial ability however did impact correct answers at F(1) = 5.63 and p = .02. No evidence was found for an impact of cognitive load on performance. Possibly, participants were able to solve the posttest items based on visuospatial information contained in the test items themselves. Additionally, the virtual anatomy may have been complex enough to discourage memory based strategies. It is important to control the amount of visuospatial information present in test items.

  12. Effects of surrounding powder in sintering process on the properties of Sb and Mn- doped barium-strontium titanate PTCR ceramics

    Directory of Open Access Journals (Sweden)

    Pornsuda Bomlai

    2006-05-01

    Full Text Available In this research, the effects of surrounding powder used during sintering of Sb and Mn doped bariumstrontium titanate (BST ceramics were studied. The ceramic samples were prepared by a conventional mixed-oxide method and placed on different powders during sintering. Phase formation, microstructure and PTCR behavior of the samples were then observed. Microstructures and PTCR behavior varied with the type of surrounding powder, whereas the crystal structure did not change. The surrounding powder has more effects on the shape of the grain than on the size. The grain size of samples was in the range of 5-20 μm. The most uniform grain size and the highest increase of the ratio of ρmax/ρRT were found to be about 106 for samples which had been sintered on Sb-doped BST powder. This value was an order of magnitude greater than for samples sintered on a powder of the equivalent composition to that of the sample pellet.

  13. Visual Surround Suppression in Schizophrenia

    Science.gov (United States)

    Tibber, Marc S.; Anderson, Elaine J.; Bobin, Tracy; Antonova, Elena; Seabright, Alice; Wright, Bernice; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast – a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with SZ demonstrated weaker SS compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation SS in SZ may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies. PMID:23450069

  14. Visuospatial working memory in specific language impairment: a meta-analysis.

    Science.gov (United States)

    Vugs, Brigitte; Cuperus, Juliane; Hendriks, Marc; Verhoeven, Ludo

    2013-09-01

    We conducted a meta-analysis of the data from studies comparing visuospatial working memory (WM) in children with specific language impairment (SLI) and typically developing (TD) children. The effect sizes of 21 studies (including 32 visuospatial storage tasks and 9 visuospatial central executive (CE) tasks) were identified via computerized database searches and the reference sections of the identified studies. Meta-analyses and moderator analyses were conducted to examine the magnitude of the differences in visuospatial storage and CE, and their relation to the inclusion criteria used for SLI and the age of the children. The results showed significant effect sizes for visuospatial storage (d=0.49) and visuospatial CE (d=0.63), indicating deficits in both components of visuospatial WM in children with SLI. The moderator analyses showed that greater impairment in visuospatial storage was associated with more pervasive language impairment, whereas age was not significant associated with visuospatial WM. The finding of deficits in visuospatial WM suggests domain-general impairments in children with SLI. It raises questions about the language-specificity of a diagnosis of SLI. Careful attention should thus be paid to both verbal and visuospatial WM in clinical practice, and especially in those children with pervasive language impairments.

  15. The visuospatial functions in children after cerebellar low-grade astrocytoma surgery: A contribution to the pediatric neuropsychology of the cerebellum.

    Science.gov (United States)

    Starowicz-Filip, Anna; Chrobak, Adrian Andrzej; Milczarek, Olga; Kwiatkowski, Stanisław

    2015-12-07

    The aim of this study was to specify whether cerebellar lesions cause visuospatial impairments in children. The study sample consisted of 40 children with low-grade cerebellar astrocytoma, who underwent surgical treatment and 40 healthy controls matched with regard to age and sex. Visuospatial abilities were tested using the spatial WISC-R subtests (Block Design and Object Assembly), Rey-Osterrieth Complex Figure, Benton Judgment of Line Orientation Test, PEBL Mental Rotation Task, and Benton Visual Retention Test. To exclude general diffuse intellectual dysfunction, the WISC-R Verbal Intelligence IQ, Performance IQ, and Full-Scale IQ scores were analysed. Post-surgical medical consequences were measured with the International Cooperative Ataxia Rating Scale. Compared to controls, the cerebellar group manifested problems with mental rotation of objects, visuospatial organization, planning, and spatial construction processes which could not be explained by medical complications or general intellectual retardation. The intensity of visuospatial syndrome highly depends on cerebellar lesion side. Patients with left-sided cerebellar lesions display more severe spatial problems than those with right-sided cerebellar lesions. In conclusion, focal cerebellar lesions in children affect their visuospatial ability. The impairments profile is characterized by deficits in complex spatial processes such as visuospatial organization and mental rotation, requiring reconstruction of visual stimuli using the imagination, while elementary sensory analysis and perception as well as spatial processes requiring direct manipulation of objects are relatively better preserved. This pattern is analogous to the one previously observed in adult population and appears to be typical for cerebellar pathology in general, regardless of age.

  16. The Third Pole Environment Programme (TPE): A new base for the processes study of atmospheric physics and environment over the Tibetan Plateau and surrounding regions

    Science.gov (United States)

    Ma, Yaoming

    2016-04-01

    The Tibetan Plateau, with the most prominent and complicated terrain on the globe and an elevation of more than 4000 m on average above sea leave (msl), is often called the "Third Pole" due to its significance parallel with Antarctica and the Arctic. The exchange of energy, water vapor and some greenhouse gases between land surface and atmosphere over the Tibetan Plateau and the surrounding regions play an important role in the Asian monsoon system, which in turn is a major component of both the energy and water cycles of the global climate system. Supported by the Chinese Academy of Sciences and some international organizations, a Third Pole Environment (TPE) Research Platform (TPEP) is now implementing over the Tibetan Plateau and surrounding region. The background of the establishment of the TPEP, the establishing and monitoring plan of long-term scale (5-10 years) of the TPEP will be shown firstly. Then the preliminary observational analysis results, such as the characteristics of land surface heat fluxes, CO2 flux and evapotranspiration (ET) partitioning (diurnal variation, inter-monthly variation and vertical variation etc), aerosol optical properties between southern and northern sides of the Himalayas, the characteristics of atmospheric and soil variables, the structure of the Atmospheric Boundary Layer (ABL) and the turbulent characteristics have also been shown in this study.

  17. Visuospatial and mathematical dysfunction in major depressive disorder and/or panic disorder: A study of parietal functioning.

    Science.gov (United States)

    Nelson, Brady D; Shankman, Stewart A

    2016-01-01

    The parietal cortex is critical for several different cognitive functions, including visuospatial processing and mathematical abilities. There is strong evidence indicating parietal dysfunction in depression. However, it is less clear whether anxiety is associated with parietal dysfunction and whether comorbid depression and anxiety are associated with greater impairment. The present study compared participants with major depression (MDD), panic disorder (PD), comorbid MDD/PD and controls on neuropsychological measures of visuospatial processing, Judgement of Line Orientation (JLO), and mathematical abilities, Wide Range Achievement Test (WRAT) Arithmetic. Only comorbid MDD/PD was associated with decreased performance on JLO, whereas all psychopathological groups exhibited comparably decreased performance on WRAT Arithmetic. Furthermore, the results were not accounted for by other comorbid disorders, medication use or psychopathology severity. The present study suggests comorbid depression and anxious arousal are associated with impairment in visuospatial processing and provides novel evidence indicating mathematical deficits across depression and/or anxiety. Implications for understanding parietal dysfunction in internalising psychopathology are discussed.

  18. The Relationship between Expertise in Sports, Visuospatial, and Basic Cognitive Skills.

    Science.gov (United States)

    Heppe, Holger; Kohler, Axel; Fleddermann, Marie-Therese; Zentgraf, Karen

    2016-01-01

    Team sports place high demands on visuospatial and other cognitive skills. However, there is a lack of research on visuospatial skills of elite athletes and there are heterogeneous results on basic cognitive skills of this population. Therefore, this series of studies tested different cognitive skills in elite team sports athletes. In Experiment 1, elite athletes were compared to recreational athletes, but no differences were observed between the groups in choice response time (CRT) and mental rotation (MR). To see if differences could be observed when the tested groups had a greater difference in expertise and more representative stimuli, in Experiment 2, we tested CRT and MR of elite athletes who had higher level of expertise, and we also used three-dimensional human stimuli. Overall, we still found no differences in MR; however, elite athletes did have shorter CRTs. In Experiment 3, instead of testing MR, we compared elite athletes' and recreational athletes' basic cognitive skills, such as processing speed, letter readout speed, memory span, and sustained attention. We found that elite athletes only performed better in sustained attention. Building on this data, in a supplementary analysis (Experiment 4) we tested whether MR and CRTs are correlated with basic cognitive skills. Results show that processing speed is the best predictor for MR, whereas letter readout speed explains most of the variance in CRTs. Finally, we discuss these findings against the backdrop of expertise and offer implications for future studies on mental rotation.

  19. Stereopsis, Visuospatial Ability, and Virtual Reality in Anatomy Learning

    OpenAIRE

    Jan-Maarten Luursema; Marc Vorstenbosch; Jan Kooloos

    2017-01-01

    A new wave of virtual reality headsets has become available. A potential benefit for the study of human anatomy is the reintroduction of stereopsis and absolute size. We report a randomized controlled trial to assess the contribution of stereopsis to anatomy learning, for students of different visuospatial ability. Sixty-three participants engaged in a one-hour session including a study phase and posttest. One group studied 3D models of the anatomy of the deep neck in full stereoptic virtual ...

  20. Decoding the Locus of Covert Visuospatial Attention from EEG Signals

    Science.gov (United States)

    Thiery, Thomas; Lajnef, Tarek; Jerbi, Karim; Arguin, Martin; Aubin, Mercedes; Jolicoeur, Pierre

    2016-01-01

    Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM) and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA). We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%). The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001). These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed. PMID:27529476

  1. Comparative Overview of Visuospatial Working Memory in Monkeys and Rats.

    Science.gov (United States)

    Tsutsui, Ken-Ichiro; Oyama, Kei; Nakamura, Shinya; Iijima, Toshio

    2016-01-01

    Neural mechanisms of working memory, particularly its visuospatial aspect, have long been studied in non-human primates. On the other hand, rodents are becoming more important in systems neuroscience, as many of the innovative research methods have become available for them. There has been a question on whether primates and rodents have similar neural backgrounds for working memory. In this article, we carried out a comparative overview of the neural mechanisms of visuospatial working memory in monkeys and rats. In monkeys, a number of lesion studies indicate that the brain region most responsible for visuospatial working memory is the ventral dorsolateral prefrontal cortex (vDLPFC), as the performance in the standard tests for visuospatial working memory, such as delayed response and delayed alternation tasks, are impaired by lesions in this region. Single-unit studies revealed a characteristic firing pattern in neurons in this area, a sustained delay activity. Further studies indicated that the information maintained in the working memory, such as cue location and response direction in a delayed response, is coded in the sustained delay activity. In rats, an area comparable to the monkey vDLPFC was found to be the dorsal part of the medial prefrontal cortex (mPFC), as the delayed alternation in a T-maze is impaired by its lesion. Recently, the sustained delay activity similar to that found in monkeys has been found in the dorsal mPFC of rats performing the delayed response task. Furthermore, anatomical studies indicate that the vDLPFC in monkeys and the dorsal mPFC in rats have much in common, such as that they are both the major targets of parieto-frontal projections. Thus lines of evidence indicate that in both monkeys and rodents, the PFC plays a critical role in working memory.

  2. Towards a visuospatial developmental account of sequence-space synaesthesia

    Directory of Open Access Journals (Sweden)

    Mark ePrice

    2013-10-01

    Full Text Available Sequence-space synaesthetes experience some sequences (e.g. numbers, calendar units as arranged in spatial forms, i.e., spatial patterns in their mind’s eye or even outside their body. Various explanations have been offered for this phenomenon. Here we argue that these spatial forms are continuous with, and share central characteristics with, varieties of non-synaesthetic visuospatial imagery. This includes their dynamic and elaborative nature, their involuntary feel and consistency over time. Drawing from literatures on mental imagery and working memory, we suggest how the initial acquisition and subsequent elaboration of spatial forms could be accounted for in terms of the known developmental trajectory of visuospatial representations. This extends from the formation of image-based representations of verbal material in childhood to the later maturation of dynamic control of imagery. Individual differences in the development of visuospatial style also account for variation in the character of spatial forms, e.g. in terms of distinctions such as visual versus spatial imagery, or ego-centric versus object-based transformations.

  3. Gaze direction affects visuo-spatial short-term memory.

    Science.gov (United States)

    Carlei, Christophe; Kerzel, Dirk

    2014-10-01

    Hemispheric asymmetries were investigated by changing the horizontal position of stimuli that had to be remembered in a visuo-spatial short-term memory task. Observers looked at matrices containing a variable number of filled squares on the left or right side of the screen center. At stimulus offset, participants reproduced the positions of the filled squares in an empty response matrix. Stimulus and response matrices were presented in the same quadrant. We observed that memory performance was better when the matrices were shown on the left side of the screen. We distinguished between recall strategies that relied on visual or non-visual (verbal) cues and found that the effect of gaze position occurred more reliably in participants using visual recall strategies. Overall, the results show that there is a solid enhancement of visuo-spatial short-term memory when observers look to the left. In contrast, vertical position had no influence on performance. We suggest that unilateral gaze to the left activates centers in the right hemisphere contributing to visuo-spatial memory. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Visuospatial impairment in Parkinson's disease: the role of laterality.

    Science.gov (United States)

    Karádi, Kázmér; Lucza, Tivadar; Aschermann, Zsuzsanna; Komoly, Sámuel; Deli, Gabriella; Bosnyák, Edit; Acs, Péter; Horváth, Réka; Janszky, József; Kovács, Norbert

    2015-01-01

    Asymmetry is one of the unique and mysterious features of Parkinson's disease (PD). Motor symptoms develop unilaterally either on the left (LPD) or the right side (RPD). Incongruent data are available whether the side of onset has an impact on cognition in PD. The objective of this study is to compare the visuospatial performance of RPD and LPD patients. Seventy-one non-demented, non-depressive and right-handed patients were categorized into RBD (n = 36) and LPD (n = 35) groups. Rey-Osterrieth Complex Figure Test (ROCF) was evaluated by both the Taylor's and Loring's scoring systems. Subsequently, we also performed subgroup analyses on patients having short disease duration (≤5 years, 15 RBD and 15 LPD patients). The standard analysis of ROCF (Taylor's system) did not reveal any differences; however, the utilization of the Loring's system demonstrated that LPD patients had significantly worse visuospatial performance than the RPD subjects (3.0 vs. 2.0 points, median, p = 0.002). Correlation between the number of spatial errors and the degree of asymmetry was significant (r = -0.437, p = 0.001). However, this difference could not be observed in PD patients with short disease duration. LPD patients had worse visuospatial performance than the RPD subjects and the number of errors tightly correlated with the degree of asymmetry and long disease duration.

  5. Phosphene Perception Relates to Visual Cortex Glutamate Levels and Covaries with Atypical Visuospatial Awareness

    Science.gov (United States)

    Terhune, Devin B.; Murray, Elizabeth; Near, Jamie; Stagg, Charlotte J.; Cowey, Alan; Cohen Kadosh, Roi

    2015-01-01

    Phosphenes are illusory visual percepts produced by the application of transcranial magnetic stimulation to occipital cortex. Phosphene thresholds, the minimum stimulation intensity required to reliably produce phosphenes, are widely used as an index of cortical excitability. However, the neural basis of phosphene thresholds and their relationship to individual differences in visual cognition are poorly understood. Here, we investigated the neurochemical basis of phosphene perception by measuring basal GABA and glutamate levels in primary visual cortex using magnetic resonance spectroscopy. We further examined whether phosphene thresholds would relate to the visuospatial phenomenology of grapheme-color synesthesia, a condition characterized by atypical binding and involuntary color photisms. Phosphene thresholds negatively correlated with glutamate concentrations in visual cortex, with lower thresholds associated with elevated glutamate. This relationship was robust, present in both controls and synesthetes, and exhibited neurochemical, topographic, and threshold specificity. Projector synesthetes, who experience color photisms as spatially colocalized with inducing graphemes, displayed lower phosphene thresholds than associator synesthetes, who experience photisms as internal images, with both exhibiting lower thresholds than controls. These results suggest that phosphene perception is driven by interindividual variation in glutamatergic activity in primary visual cortex and relates to cortical processes underlying individual differences in visuospatial awareness. PMID:25725043

  6. Phosphene Perception Relates to Visual Cortex Glutamate Levels and Covaries with Atypical Visuospatial Awareness.

    Science.gov (United States)

    Terhune, Devin B; Murray, Elizabeth; Near, Jamie; Stagg, Charlotte J; Cowey, Alan; Cohen Kadosh, Roi

    2015-11-01

    Phosphenes are illusory visual percepts produced by the application of transcranial magnetic stimulation to occipital cortex. Phosphene thresholds, the minimum stimulation intensity required to reliably produce phosphenes, are widely used as an index of cortical excitability. However, the neural basis of phosphene thresholds and their relationship to individual differences in visual cognition are poorly understood. Here, we investigated the neurochemical basis of phosphene perception by measuring basal GABA and glutamate levels in primary visual cortex using magnetic resonance spectroscopy. We further examined whether phosphene thresholds would relate to the visuospatial phenomenology of grapheme-color synesthesia, a condition characterized by atypical binding and involuntary color photisms. Phosphene thresholds negatively correlated with glutamate concentrations in visual cortex, with lower thresholds associated with elevated glutamate. This relationship was robust, present in both controls and synesthetes, and exhibited neurochemical, topographic, and threshold specificity. Projector synesthetes, who experience color photisms as spatially colocalized with inducing graphemes, displayed lower phosphene thresholds than associator synesthetes, who experience photisms as internal images, with both exhibiting lower thresholds than controls. These results suggest that phosphene perception is driven by interindividual variation in glutamatergic activity in primary visual cortex and relates to cortical processes underlying individual differences in visuospatial awareness.

  7. Visuospatial transformations and personality: evidence of a relationship between visuospatial perspective taking and self-reported emotional empathy.

    Science.gov (United States)

    Sulpizio, Valentina; Committeri, Giorgia; Metta, Emilia; Lambrey, Simon; Berthoz, Alain; Galati, Gaspare

    2015-07-01

    In the visuospatial domain, perspective taking is the ability to imagine how a visual scene appears from an external observer's viewpoint, and can be studied by asking subjects to encode object locations in a visual scene where another individual is present and then detecting their displacement when seeing the scene from the other's viewpoint. In the current study, we explored the relationship between visuospatial perspective taking and self-report measures of the cognitive and emotional components of empathy in young adults. To this aim, we employed a priming paradigm, in which the presence of an avatar allowed to anticipate the next perceived perspective on the visual scene. We found that the emotional dimension of empathy was positively correlated with the behavioral advantage provided by the presence of the avatar, relative to unprimed perspective changes. These data suggest a link between the tendency to vicariously experience the others' emotions and the ability to perform self-other spatial transformations.

  8. 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.

  9. Effect of gases and particulate matter from electricity generation process on the radial growth of teak plantations surrounding Mae Moh power plant, Lampang province

    Directory of Open Access Journals (Sweden)

    Narapong Sangram

    2016-03-01

    Full Text Available The objectives of this study were to investigate radial growth patterns and influences of polluting gases and particulate matter on the radial growth of teak plantations surrounding the Mae Moh Power Plant. Twenty-four 32-year-old teak trees were selected from Mae Jang and Mae Moh plantations, which were 5 km and 15 km from the Mae Moe power plant, respectively. Forty-eight sample cores were collected from the 24 trees (two cores per tree. The growth patterns of all the cores were analyzed following the standard methods of dendrochronology. The relationships between the growth pattern and the amounts of sulfur dioxide, nitrogen dioxide, carbon monoxide and particulate matter were measured as average daily rates and then analyzed. The study showed that the best-fit model for the relationship between the radial current annual increment at breast height (CAIdbh and time (Y was an exponential equation. The fitted equations were: CAIdbh = 10.657e(−0.031Y for Mae Moh plantation and CAIdbh = 12.518e(−0.032Y for Mae Jang plantation. The coefficient of determination for the fitted equations was 0.410 and 0.423 for the Mae Moh and Mae Jang plantations, respectively. Moreover, carbon monoxide (CO and sulfur dioxide (SO2 had a statistically significant effect on radial teak growth (RT in the Mae Jang plantation, with a coefficient of determination of 0.69 (RTmj = 0.571 + 0.429(CO − 0.023(SO2.

  10. Combinatorial brain decoding of people’s whereabouts during visuospatial navigation

    Directory of Open Access Journals (Sweden)

    Hans P Op De Beeck

    2013-05-01

    Full Text Available Complex behavior typically relies upon many different processes which are related to activity in multiple brain regions. In contrast, neuroimaging analyses typically focus upon isolated processes. Here we present a new approach, combinatorial brain decoding, in which we decode complex behaviour by combining the information which we can retrieve from the neural signals about the many different sub-processes. The case in point is visuospatial navigation. Here wWe explore the extent to which the route travelled by human subjects (N=3 in a complex virtual maze can be decoded from activity patterns as measured with functional magnetic resonance imaging. Preliminary analyses suggest that it is difficult to directly decode spatial position from regions known to contain an explicit cognitive map of the environment, such as the hippocampus. Instead, we were able to indirectly derive spatial position from the pattern of activity associated with nonspatial cortical representations, including in visual and motor cortex. The nonspatial representations in these regions reflect processes which are inherent to navigation, such as which stimuli are perceived at which point in time and which motor movement is executed when (e.g., turning left at a crossroad. Highly successful decoding of routes followed through the maze was possible by combining information about multiple aspects of navigation events across time and across multiple cortical regions. This proof of principle study highlights how visuospatial navigation is related to the combined activity of multiple brain regions, and establishes combinatorial brain decoding as a means to study complex mental events that involve a dynamic interplay of many cognitive processes.

  11. Movement and visual coding: the structure of visuo-spatial working memory.

    Science.gov (United States)

    Quinn, J G

    2008-03-01

    The influential model of verbal working memory (WM) introduced by Baddeley and Hitch (Recent advances in learning and motivation. Academic, New York, 1974) comprised three interacting component parts; an executive controller and two subservient systems. The two subservient systems, one underpinning verbal processing and the other underpinning visual processing are themselves subdivided. In the verbal system, a passive phonological store is maintained by an active phonological loop, which is able to rehearse the material in the passive store. The visual working memory system has traditionally been thought of as having a similar architecture with a passive visual store being maintained by an active store, which codes in terms of movement over space. The paper discusses the evidence for this relationship in visuo-spatial WM and concludes that the architecture does not fit well with the experimental literature. A direction for future research is suggested.

  12. PREVALENCE AND ANTIMICROBIAL RESISTANCE OF SALMONELLA ISOLATED FROM CARCASSES, PROCESSING FACILITIES AND THE ENVIRONMENT SURROUNDING SMALL SCALE POULTRY SLAUGHTERHOUSES IN THAILAND.

    Science.gov (United States)

    Chotinun, Suwit; Rojanasthien, Suvichai; Unger, Fred; Tadee, Pakpoom; Patchanee, Prapas

    2014-11-01

    Salmonella is a major food-borne pathogen worldwide, including Thai- land, and poultry meat plays a role as a vehicle for the spread of the disease from animals to humans. The prevalence and characteristics of Salmonella isolated from 41 small scale poultry slaughterhouses in Chiang Mai, Thailand were determined during July 2011 through May 2012. Salmonella's prevalence in live poultry, car- casses, waste water, and soil around processing plants were 3.2%, 7.3%, 22.0% and 29.0%, respectively. Eighteen different serotypes were identified, the most common being Corvallis (15.2%), followed by Rissen (13.9%), Hadar (12.7%), Enteritidis (10.1%), [I. 4,5,12:i:-] (8.8%), Stanley (8.8%), and Weltevreden (8.8%). Antimicrobial susceptibility tests revealed that 68.4% of the Salmonella spp were resistant to at least one antimicrobial while 50.6% showed multiple drug resis- tance (MDR). Specifically, 44.3% of Salmonella were resistant to nalidixic acid, followed by streptomycin (41.8%), ampicillin (34.2%), tetracycline (34.2%), and sulfamethoxazole/trimethoprim (20.3%). Salmonella contamination was found in processing lines, carcasses, and in the environment around the processing sta- tions. These findings indicate that improving hygiene management in small scale poultry slaughterhouses as well as prudent use of antimicrobial drugs is urgently needed if Salmonella contamination is to be reduced.

  13. Optimization of apparatus design and behavioral measures for the assessment of visuo-spatial learning and memory of mice on the Barnes maze.

    Science.gov (United States)

    O'Leary, Timothy P; Brown, Richard E

    2013-01-15

    We have previously shown that apparatus design can affect visual-spatial cue use and memory performance of mice on the Barnes maze. The present experiment extends these findings by determining the optimal behavioral measures and test procedure for analyzing visuo-spatial learning and memory in three different Barnes maze designs. Male and female C57BL/6J mice were trained with a stable or random escape hole location and the sensitivities (statistical power) of four commonly used measures of learning and three measures of memory to detect differences between these training procedures were compared on each maze design. A maze design with a large diameter and no wall was optimal, because mice showed a reliable use of extra-maze visual cues, visuo-spatial search strategies, and spatial memory. A maze design with a small diameter, surrounding wall, and intra-maze visual cues was the least sensitive for determining visuo-spatial learning and memory, because mice showed little evidence of extra-maze cue use. Errors, distance traveled, and hole deviation scores were more sensitive measures of learning than latency to find the escape hole. Measures based on locating the escape hole (primary measures) were more sensitive than measures based on entering the escape hole (total measures). Measures of memory had similar levels of sensitivity on each maze. This experiment demonstrates that both apparatus design and the behavioral measures used as indicators of learning and memory can influence the ability of the Barnes maze to detect visuo-spatial learning and memory impairments in mice.

  14. A lateralized top-down network for visuospatial attention and neglect.

    Science.gov (United States)

    Wang, Jiaojian; Tian, Yanghua; Wang, Mengzhu; Cao, Long; Wu, Huawang; Zhang, Yun; Wang, Kai; Jiang, Tianzi

    2016-12-01

    The lateralization of visuospatial attention has been well investigated and demonstrated to be primarily resulting from unbalanced interaction between interhemispheric fronto-parietal networks in previous studies. Many recent studies of top-down attention have reported the neural signatures of its effects within visual cortex and identified its causal basis. However, the relationship between top-down networks and asymmetric visuospatial attention has not been well studied. In the current study, we aimed to explore the relationship between top-down connectivity and asymmetric visuospatial ability by using repetitive transcranial magnetic stimulation (rTMS) and resting-state functional connectivity (RSFC) analyses. We used rTMS and RSFC to model the virtual lesion to assess the behavioral performances in visuospatial attention shifting and to identify the behavior-related top-down functional connectivities, respectively. Furthermore, we also investigated the top-down connectivity in neglect patients to validate the RSFC findings. RSFC analyses in healthy subjects and neglect patients consistently revealed that asymmetric visuospatial ability and visuospatial neglect were closely related to the bias of top-down functional connectivity between posterior superior parietal lobule (SPL) and V1. Our findings indicate that stronger top-down connectivity has stronger dominance on its corresponding visual field. We argue that an asymmetric top-down network may represent a possible neurophysiological substrate for the ongoing functional asymmetry of visuospatial attention, and its interhemispheric unbalanced interaction could contribute to the clinical manifestations of visuospatial neglect.

  15. Visuospatial Perception in Children Born Preterm With No Major Neurological Disorders

    NARCIS (Netherlands)

    Butcher, Phillipa R.; Bouma, Anke; Stremmelaar, Elisabeth F.; Bos, Arend F.; Smithson, Michael; Van Braeckel, Koenraad N. J. A.

    2012-01-01

    Objective: Many investigations have found deficits in visuospatial perception in children born preterm, however, it is not clear whether the deficits are specific to visuospatial perception or the consequences of deficits in other functional areas, which often accompany preterm birth. This study

  16. Visuospatial Perception in Children Born Preterm With No Major Neurological Disorders

    NARCIS (Netherlands)

    Butcher, Phillipa R.; Bouma, Anke; Stremmelaar, Elisabeth F.; Bos, Arend F.; Smithson, Michael; Van Braeckel, Koenraad N. J. A.

    2012-01-01

    Objective: Many investigations have found deficits in visuospatial perception in children born preterm, however, it is not clear whether the deficits are specific to visuospatial perception or the consequences of deficits in other functional areas, which often accompany preterm birth. This study inv

  17. The Neuroanatomical Basis for Posterior Superior Parietal Lobule Control Lateralization of Visuospatial Attention.

    Science.gov (United States)

    Wu, Yan; Wang, Jiaojian; Zhang, Yun; Zheng, Dingchen; Zhang, Jinfeng; Rong, Menglin; Wu, Huawang; Wang, Yinyan; Zhou, Ke; Jiang, Tianzi

    2016-01-01

    The right hemispheric dominance in visuospatial attention in human brain has been well established. Converging evidence has documented that ventral posterior parietal cortex (PPC) plays an important role in visuospatial attention. The role of dorsal PPC subregions, especially the superior parietal lobule (SPL) in visuospatial attention is still controversial. In the current study, we used repetitive transcranial magnetic stimulation (rTMS) and diffusion magnetic resonance imaging (MRI) techniques to test the role of posterior SPL in visuospatial attention and to investigate the potential neuroanatomical basis for right hemisphere dominance in visuospatial function. Transcranial magnetic stimulation (TMS) results unraveled that the right SPL predominantly mediated visuospatial attention compared to left SPL. Anatomical connections analyses between the posterior SPL and the intrahemispheric frontal subregions and the contralateral PPC revealed that right posterior SPL has stronger anatomical connections with the ipsilateral middle frontal gyrus (MFG), with the ipsilateral inferior frontal gyrus (IFG), and with contralateral PPC than that of the left posterior SPL. Furthermore, these asymmetric anatomical connections were closely related to behavioral performances. Our findings indicate that SPL plays a crucial role in regulating visuospatial attention, and dominance of visuospatial attention results from unbalanced interactions between the bilateral fronto-parietal networks and the interhemispheric parietal network.

  18. Developmental Shifts in fMRI Activations during Visuospatial Relational Reasoning

    Science.gov (United States)

    Eslinger, Paul J.; Blair, Clancy; Wang, JianLi; Lipovsky, Bryn; Realmuto, Jennifer; Baker, David; Thorne, Steven; Gamson, David; Zimmerman, Erin; Rohrer, Lisa; Yang, Qing X.

    2009-01-01

    To investigate maturational plasticity of fluid cognition systems, functional brain imaging was undertaken in healthy 8-19 year old participants while completing visuospatial relational reasoning problems similar to Raven's matrices and current elementary grade math textbooks. Analyses revealed that visuospatial relational reasoning across this…

  19. Visuospatial characteristics of an elderly Chinese population: results from the WAIS-R block design test.

    Science.gov (United States)

    Yin, Shufei; Zhu, Xinyi; Huang, Xin; Li, Juan

    2015-01-01

    Visuospatial deficits have long been recognized as a potential predictor of dementia, with visuospatial ability decline having been found to accelerate in later stages of dementia. We, therefore, believe that the visuospatial performance of patients with mild cognitive impairment (MCI) and dementia (Dem) might change with varying visuospatial task difficulties. This study administered the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Block Design Test (BDT) to determine whether visuospatial ability can help discriminate between MCI patients from Dem patients and normal controls (NC). Results showed that the BDT could contribute to the discrimination between MCI and Dem. Specifically, simple BDT task scores could best distinguish MCI from Dem patients, while difficult BDT task scores could contribute to discriminating between MCI and NC. Given the potential clinical value of the BDT in the diagnosis of Dem and MCI, normative data stratified by age and education for the Chinese elderly population are presented for use in research and clinical settings.

  20. Visuospatial characteristics of an elderly Chinese population: results from the WAIS-R Block Design Test

    Directory of Open Access Journals (Sweden)

    Shufei eYin

    2015-02-01

    Full Text Available Visuospatial deficits have long been recognized as a potential predictor of dementia, with visuospatial ability decline having been found to accelerate in later stages of dementia. We, therefore, believe that the visuospatial performance of patients with mild cognitive impairment (MCI and dementia (Dem might change with varying visuospatial task difficulties. This study administered the WAIS-R Block Design Test (BDT to determine whether visuospatial ability can help discriminate between MCI patients from Dem patients and normal controls (NC. Results showed that the BDT could contribute to the discrimination between MCI and Dem. Specifically, simple BDT task scores could best distinguish MCI from Dem patients, while difficult BDT task scores could contribute to discriminating between MCI and NC. Given the potential clinical value of the BDT in the diagnosis of Dem and MCI, normative data stratified by age and education for the Chinese elderly population are presented for use in research and clinical settings.

  1. Sex differences in effects of testing medium and response format on a visuospatial task.

    Science.gov (United States)

    Cherney, Isabelle D; Rendell, Jariel A

    2010-06-01

    Sex differences on visuospatial tests are among the most reliably replicated. It is unclear to what extent these performance differences reflect underlying differences in skills or testing factors. To assess whether testing medium and response format affect visuospatial sex differences, performances of introductory psychology students (100 men, 104 women) were examined on a visuospatial task presented in paper-and-pencil and tablet computer forms. Both sexes performed better when tested on paper, although men outperformed women. The introduction of an open-ended component to the visuospatial task eliminated sex differences when prior spatial experiences were controlled, but men outperformed women when prior spatial experiences were not considered. In general, the open-ended version and computerized format of the test diminished performance, suggesting that response format and medium are testing factors that influence visuospatial abilities.

  2. The role of the surrounding polarity on the phototautomerization process in a diazaaromatic compound: An UV–vis and NMR study

    Energy Technology Data Exchange (ETDEWEB)

    Reyman, Dolores, E-mail: dolores.reyman@uam.es [Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, E-28049 (Spain); Montoro, Teresa [EUIT Forestales, Universidad Politécnica de Madrid, 28040 Madrid (Spain); Viñas, Montserrat H. [Departamento de Sistemas Inteligentes Aplicados, Universidad Politécnica de Madrid, E-28031 Madrid (Spain); Díaz-Oliva, Cristina [Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, E-28049 (Spain); Tardajos, Gloria [Departamento de Química Física I, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2014-04-15

    Fluorescence steady-state and decay measurements of the azaaromatic derivative norharmane were obtained in solvents with different polarities: dichloromethane (DCM) and acetonitrile (ACN), at different temperatures, in the absence and the presence of a donor/acceptor hydrogen bond such as acetic acid. 2D NOESY experiments confirmed that this compound forms a hydrogen-bonding cyclic complex with acetic acid in the ground state. This complex induced a phototautomeric equilibrium, which produced new emission bands at 400 and 500 nm. This tautomeric process was established only in the first excited state via a concerted proton–electron transfer. Indeed, the cyclic complex formed in the ground state evolved to a like-cation upon cooling from room temperature to 225 K, and a new emission band at 450 nm is observed. The fluorescence decay times confirmed these results. -- Highlights: • 2D NOESY experiments confirm that norharmane forms a hydrogen-bonding cyclic complex with acetic acid molecules • This complex induces a phototautomeric equilibrium via a concerted proton–electron transfer. • A monotonous transformation of the type OH···N→ O{sup δ−}···H···N{sup δ+}→ O{sup −}···HN{sup +} occurs when the temperature is lowered. • Resulting from this transformation, the four fluorescence bands observed at room temperature are converted into a single fluorescence band at 225 K.

  3. Clinical Application of Surrounding Puncture

    Institute of Scientific and Technical Information of China (English)

    GUO Yao-jie; HAN Chou-ping

    2003-01-01

    Surrounding puncture can stop pathogenic qi from spreading, consolidate the connection between local meridians and enrich local qi and blood, which can eventually supplement anti-pathogenic qi and remove pathogenic qi, and consequently remedy diseases. The author of this article summrized and analyzed the clinical application of surrounding puncture for the purpose of studying this technique and improving the therapeutic effect.

  4. Right prefrontal TMS disrupts interregional anticipatory EEG alpha activity during shifting of visuospatial attention

    Directory of Open Access Journals (Sweden)

    Paul eSauseng

    2011-10-01

    Full Text Available Visual attention can be shifted in space without moving the eyes. Amplitude decrease of rhythmical brain activity around 10 Hz (so called alpha activity at contralateral posterior sites has been reported during covert shifts of visuospatial attention to one visual hemifield. Alpha amplitude increase, on the other hand, can be found at ipsilateral visual cortex. There is some evidence suggesting an involvement of prefrontal brain areas during the control of attention-related anticipatory alpha amplitude asymmetry. However, the exact neural mechanism by which prefrontal cortex influences visual processing has not been completely clear yet. This open question has been studied in detail using a multimodal approach combining transcranial magnetic stimulation (TMS and multichannel electroencephalography (EEG in healthy humans. Slow (1 Hz repetitive TMS inducing an inhibitory effect at the stimulation site was delivered either to right frontal eye field or a control site (vertex. Subsequently, participants had to perform a spatial cueing task in which covert shifts of attention were required to either the left or the right visual hemi-field. After stimulation at the vertex (control condition a pattern of anticipatory, attention-related ipsilateral alpha increase / contralateral alpha decrease over posterior recording sites could be obtained. Additionally, there was pronounced coupling between (in particular right FEF and posterior brain sites. When, however, the right prefrontal cortex had been virtually lesioned preceding the task, these EEG correlates of visuospatial attention were attenuated. Notably, the effect of TMS at the right FEF on interregional fronto-parietal alpha coupling predicted the effect on response times. This suggests that visual attention processes associated with posterior EEG alpha activity are at least partly top-down controlled by the prefrontal cortex.

  5. Enhancing visuospatial learning: the benefit of retrieval practice.

    Science.gov (United States)

    Kang, Sean H K

    2010-12-01

    Studies examining the beneficial effect of testing on memory have relied almost exclusively on verbal materials. Whether testing can improve the learning of novel, abstract visuospatial information was investigated, using Chinese characters as study stimuli. Subjects with no prior Chinese language experience studied English words paired with their Chinese equivalents. Subsequently, they either restudied the pairs twice or attempted to retrieve covertly the Chinese characters twice (with feedback provided afterward). The durations of the study and the retrieval/feedback trials were equated. On a final test given after 10 min (Experiment 1) or 24 h (Experiment 2), the subjects who had practiced retrieval were more accurate at writing/drawing the Chinese characters than were those who had studied repeatedly. The same result was replicated when learning condition was manipulated within subjects (Experiment 3). In predictions of future performance made after training, however, the subjects seemed unaware that retrieval practice was more effective than repeated studying. Testing enhances visuospatial learning, with potential implications for learning a foreign language that uses a writing script different from one's language: Repeated retrieval from memory trumps repeated studying.

  6. Assessing visuospatial abilities in healthy aging: A novel visuomotor task

    Directory of Open Access Journals (Sweden)

    Natalie eDe Bruin

    2016-02-01

    Full Text Available This study examined the efficacy of a novel reaching-and-grasping task in determining visuospatial abilities across adulthood. The task required male and female young (18-25 years and older adults (60-82 years to replicate a series of complex models by locating and retrieving the appropriate building blocks from an array. The task allows visuospatial complexity to be manipulated independently from the visuomotor demands. Mental rotation and spatial visualisation abilities were assessed. The results showed that the time taken to complete the tasks increased with increased mental rotation complexity. Patterns of hand use were also influenced by the complexity of the models being constructed with right hand use being greater for the less complex models. In addition, although older adults consistently performed the visuomotor tasks slower than the younger adults, their performance was comparable when expressed as the percent change in task demands. This is suggestive that spatial abilities are preserved in older adults. Given the ecologically validity, the described task is an excellent candidate for investigating (1 developmental, (2 sex-based and (3 pathology-based differences in spatial abilities in the visuomotor domain.

  7. A bilateral frontoparietal network underlies visuospatial analogical reasoning.

    Science.gov (United States)

    Watson, Christine E; Chatterjee, Anjan

    2012-02-01

    Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Usefulness of Color Coding Resected Samples from a Pancreaticoduodenectomy with Tissue Marking Dyes for a Detailed Examination of Surgical Margin Surrounding the Uncinate Process of the Pancreas.

    Science.gov (United States)

    Mizutani, Satoshi; Suzuki, Hideyuki; Aimoto, Takayuki; Yamagishi, Seiji; Mishima, Keisuke; Watanabe, Masanori; Kitayama, Yasuhiko; Motoda, Norio; Isshiki, Saiko; Uchida, Eiji

    2017-01-01

    Characteristics of a cancer-positive margin around a resected uncinate process of the pancreas (MUP) due to a pancreticoduodenectomy are difficult to understand by standardized evaluation because of its complex anatomy. The purposes of this study were to subclassify the MUP with tissue marking dyes of different colors and to identify the characteristics of sites that showed positivity for cancer cells in patients with pancreatic head carcinoma who underwent circumferential superior mesenteric arterial nerve plexus-preserving pancreaticoduodenectomy. Results of this evaluation were used to review operation procedures and perioperative methods. We divided the MUP into 4 sections and stained each section with a different color. These sections were the pancreatic head nerve plexus margin (Area A), portal vein groove margin (Area B), superior mesenteric artery margin (Area C), and left of the superior mesenteric artery margin (Area D). The subjects evaluated were 45 patients who had carcinoma of the pancreatic head and were treated with circumferential superior mesenteric arterial nerve plexus-preserving pancreaticoduodenectomy. Of the 45 patients, nine cases (90%) of incomplete resection showed cancer-positivity in the MUP. Among the 4 sections of the MUP, the most cases of positive results [MUP (+) ] were found in Area B, with Area A (+), 0 case; Area B (+), 6 cases; Area C (+), 2 cases; and Area D (+), 3 cases (total, 11 sites in 9 patients). Relapse occurred in 7 of the 9 patients with MUP (+). Local recurrence was observed as initial relapse in all 3 patients with Area D (+). In contrast, the most common site of recurrence other than that in patients with Area D (+) was the liver. By subclassifying the MUP with tissue marking dyes of different colors, we could confirm regional characteristics of MUP (+). As a result, circumferential superior mesenteric arterial nerve plexus-preserving pancreticoduodenectomy was able to be performed in R0 operations in selected

  9. Visuospatial and Verbal Short-Term Memory Correlates of Vocabulary Ability in Preschool Children.

    Science.gov (United States)

    Stokes, Stephanie F; Klee, Thomas; Kornisch, Myriam; Furlong, Lisa

    2017-08-16

    Recent studies indicate that school-age children's patterns of performance on measures of verbal and visuospatial short-term memory (STM) and working memory (WM) differ across types of neurodevelopmental disorders. Because these disorders are often characterized by early language delay, administering STM and WM tests to toddlers could improve prediction of neurodevelopmental outcomes. Toddler-appropriate verbal, but not visuospatial, STM and WM tasks are available. A toddler-appropriate visuospatial STM test is introduced. Tests of verbal STM, visuospatial STM, expressive vocabulary, and receptive vocabulary were administered to 92 English-speaking children aged 2-5 years. Mean test scores did not differ for boys and girls. Visuospatial and verbal STM scores were not significantly correlated when age was partialed out. Age, visuospatial STM scores, and verbal STM scores accounted for unique variance in expressive (51%, 3%, and 4%, respectively) and receptive vocabulary scores (53%, 5%, and 2%, respectively) in multiple regression analyses. Replication studies, a fuller test battery comprising visuospatial and verbal STM and WM tests, and a general intelligence test are required before exploring the usefulness of these STM tests for predicting longitudinal outcomes. The lack of an association between the STM tests suggests that the instruments have face validity and test independent STM skills.

  10. The effect of cognitive status and visuospatial performance on affective theory of mind in Parkinson's disease.

    Science.gov (United States)

    McKinlay, Audrey; Albicini, Michelle; Kavanagh, Phillip S

    2013-01-01

    It is now well accepted that theory of mind (ToM) functioning is impaired in Parkinson's disease (PD) patients. However, what remain unknown are the functions that underlie this impairment. It has been suggested that cognitive skills may be key in this area of functioning; however, many of the cognitive tests used to assess this have relied on intact visuospatial abilities. This study aimed to examine whether deficits in ToM were generated by cognitive or visuospatial dysfunction and the mediating effect of visuospatial function on ToM performance. Fifty PD patients (31 male, 19 female; mean age = 66.34 years) and 49 healthy controls (16 male, 33 female; mean age = 67.29 years) completed a ToM task (reading the mind in the eyes) and visuospatial task (line orientation). The results revealed that current cognitive status was a significant predictor for performance on the ToM task, and that 54% of the total effect of cognitive status on ToM was mediated by visuospatial abilities. It was concluded that visuospatial functioning plays an important mediating role for the relationship between executive dysfunction and affective ToM deficits in PD patients, and that visuospatial deficits may directly contribute to the presence of affective ToM difficulties seen in individuals with PD.

  11. Educational Success and Surrounding Culture

    Science.gov (United States)

    Walters, Garrison

    2016-01-01

    The curriculum, instruction, and services we provide in schools, colleges, and universities matter a lot, but if we continue to ignore our students' "surrounding culture," progress toward a more educated nation will continue to be disappointing.

  12. Educational Success and Surrounding Culture

    Science.gov (United States)

    Walters, Garrison

    2016-01-01

    The curriculum, instruction, and services we provide in schools, colleges, and universities matter a lot, but if we continue to ignore our students' "surrounding culture," progress toward a more educated nation will continue to be disappointing.

  13. Multichannel spatial surround sound system

    Institute of Scientific and Technical Information of China (English)

    RAO Dan; XIE Bosun

    2004-01-01

    Based on the consideration of being compatible with 5.1 channel horizontal surround sound system, a spatial surround sound system is proposed. Theoretical and experimental results show that the system has a wide listening area. It can not only recreate stable image in the front and rear direction, but also eliminate the defect of poor lateral image of 5.1 channel system. The system can be used to reproduce special 3D sound effect and the spaciousness of hall.

  14. A metacognitive visuospatial working memory training for children

    Directory of Open Access Journals (Sweden)

    Sara CAVIOLA

    2009-10-01

    Full Text Available The paper studies whether visuospatial working memory (VSWM and, specifically, recall of sequential-spatial information, can be improved by metacognitive training. Twenty-two fourth-grade children were involved in seven sessions of sequential-spatial memory training, while twenty-four children attended lessons given by their teacher. The post-training evaluation demonstrated a specific improvement of performances in the Corsi blocks task, considered a sequential-spatial working memory task. However, no benefits of training were observed in either a verbal working memory task or a simultaneous-spatial working memory task. The results have important theoretical implications, in the study of VSWM components, and educational implications, in catering for children with specific VSWM impairments.

  15. Does consolidation of visuospatial sequence knowledge depend on eye movements?

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    Coomans, Daphné; Vandenbossche, Jochen; Homblé, Koen; Van den Bussche, Eva; Soetens, Eric; Deroost, Natacha

    2014-01-01

    In the current study, we assessed whether visuospatial sequence knowledge is retained over 24 hours and whether this retention is dependent on the occurrence of eye movements. Participants performed two sessions of a serial reaction time (SRT) task in which they had to manually react to the identity of a target letter pair presented in one of four locations around a fixation cross. When the letter pair 'XO' was presented, a left response had to be given, when the letter pair 'OX' was presented, a right response was required. In the Eye Movements (EM) condition, eye movements were necessary to perform the task since the fixation cross and the target were separated by at least 9° visual angle. In the No Eye Movements (NEM) condition, on the other hand, eye movements were minimized by keeping the distance from the fixation cross to the target below 1° visual angle and by limiting the stimulus presentation to 100 ms. Since the target identity changed randomly in both conditions, no manual response sequence was present in the task. However, target location was structured according to a deterministic sequence in both the EM and NEM condition. Learning of the target location sequence was determined at the end of the first session and 24 hours after initial learning. Results indicated that the sequence learning effect in the SRT task diminished, yet remained significant, over the 24 hour interval in both conditions. Importantly, the difference in eye movements had no impact on the transfer of sequence knowledge. These results suggest that the retention of visuospatial sequence knowledge occurs alike, irrespective of whether this knowledge is supported by eye movements or not.

  16. Does consolidation of visuospatial sequence knowledge depend on eye movements?

    Directory of Open Access Journals (Sweden)

    Daphné Coomans

    Full Text Available In the current study, we assessed whether visuospatial sequence knowledge is retained over 24 hours and whether this retention is dependent on the occurrence of eye movements. Participants performed two sessions of a serial reaction time (SRT task in which they had to manually react to the identity of a target letter pair presented in one of four locations around a fixation cross. When the letter pair 'XO' was presented, a left response had to be given, when the letter pair 'OX' was presented, a right response was required. In the Eye Movements (EM condition, eye movements were necessary to perform the task since the fixation cross and the target were separated by at least 9° visual angle. In the No Eye Movements (NEM condition, on the other hand, eye movements were minimized by keeping the distance from the fixation cross to the target below 1° visual angle and by limiting the stimulus presentation to 100 ms. Since the target identity changed randomly in both conditions, no manual response sequence was present in the task. However, target location was structured according to a deterministic sequence in both the EM and NEM condition. Learning of the target location sequence was determined at the end of the first session and 24 hours after initial learning. Results indicated that the sequence learning effect in the SRT task diminished, yet remained significant, over the 24 hour interval in both conditions. Importantly, the difference in eye movements had no impact on the transfer of sequence knowledge. These results suggest that the retention of visuospatial sequence knowledge occurs alike, irrespective of whether this knowledge is supported by eye movements or not.

  17. Sex differences in episodic memory: the impact of verbal and visuospatial ability.

    Science.gov (United States)

    Herlitz, A; Airaksinen, E; Nordström, E

    1999-10-01

    The impact of verbal and visuospatial ability on sex differences in episodic memory was investigated. One hundred men and 100 women, 2040 years old, participated in a series of verbal and visuospatial tasks. Episodic memory was assessed in tasks that, to a greater or lesser extent, were verbal or visuospatial in nature. Results showed that women excelled in verbal production tasks and that men performed at a superior level on a mental rotation task. In addition, women tended to perform at a higher level than men on most episodic memory tasks. Taken together, the results demonstrated that (a) women perform at a higher level than men on most verbal episodic memory tasks and on some episodic memory tasks with a visuospatial component, and (b) women's higher performance on episodic memory tasks cannot fully be explained by their superior performance on verbal production tasks.

  18. Benefits of Training Visuospatial Working Memory in Young-Old and Old-Old

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    Borella, Erika; Carretti, Barbara; Cantarella, Alessandra; Riboldi, Francesco; Zavagnin, Michela; De Beni, Rossana

    2014-01-01

    The purpose of the present study was to test the efficacy of a visuospatial working memory (WM) training in terms of its transfer effects and maintenance effects, in the young-old and old-old. Forty young-old and 40 old-old adults took part in the study. Twenty participants in each age group received training with a visuospatial WM task, whereas…

  19. Visuospatial stimulus-bound automatic writing behavior: a right hemispheric stroke syndrome.

    Science.gov (United States)

    Evyapan, D; Kumral, E

    2001-01-23

    Three cases of visuospatial stimulus-bound automatic writing behavior were identified among 80 patients (4%) with acute right cerebral hemispheric stroke. All cases had similar clinical characteristics and writing behavior, and visuospatial stimulus-bound automatic writing was related to visually perceived letters. This syndrome might be specific for right hemispheric stroke and might be included among other hypergraphic syndromes attributable to right hemispheric damage.

  20. Visuospatial working memory is severely impaired in Bálint syndrome patients.

    Science.gov (United States)

    Funayama, Michitaka; Nakagawa, Yoshitaka; Sunagawa, Kosaku

    2015-08-01

    Although it has been proposed that visuospatial working memory may be impaired in Bálint syndrome patients, neither a systematic study concerning this proposal nor a comparison with patients having right-parietal damage has been made. Visuospatial working memory was assessed for six Bálint syndrome patients and members of two control groups-one composed of individuals with right-parietal damage (n = 15) and a second of age- and gender-matched healthy individuals (n = 26). We placed special emphasis on patients with a mild form of Bálint syndrome who can judge positional relationships between two objects. First, the participants were subjected to delayed visuospatial matching tasks. Next, their visuospatial-temporal integration abilities were assessed using a shape-from-moving-dots task. Visuospatial working memory was impaired for Bálint syndrome patients compared with controls according to the results of the tests. The differences between the Bálint syndrome and control subjects remained when only data for patients with the mild form of Bálint syndrome were included. We conclude that visuospatial working memory may be severely impaired in Bálint syndrome patients and, therefore, might influence their inability to properly execute movements and behaviours associated with daily living.

  1. Effects of nicotine on visuo-spatial selective attention as indexed by event-related potentials.

    Science.gov (United States)

    Meinke, A; Thiel, C M; Fink, G R

    2006-08-11

    Nicotine has been shown to specifically reduce reaction times to invalidly cued targets in spatial cueing paradigms. In two experiments, we used event-related potentials to test whether the facilitative effect of nicotine upon the detection of invalidly cued targets is due to a modulation of perceptual processing, as indexed by early attention-related event-related potential components. Furthermore, we assessed whether the effect of nicotine on such unattended stimuli depends upon the use of exogenous or endogenous cues. In both experiments, the electroencephalogram was recorded while non-smokers completed discrimination tasks in Posner-type paradigms after chewing a nicotine polacrilex gum (Nicorette 2 mg) in one session and a placebo gum in another session. Nicotine reduced reaction times to invalidly cued targets when cueing was endogenous. In contrast, no differential effect of nicotine on reaction times was observed when exogenous cues were used. Electrophysiologically, we found a similar attentional modulation of the P1 and N1 components under placebo and nicotine but a differential modulation of later event-related potential components at a frontocentral site. The lack of a drug-dependent modulation of P1 and N1 in the presence of a behavioral effect suggests that the effect of nicotine in endogenous visuo-spatial cueing tasks is not due to an alteration of perceptual processes. Rather, the differential modulation of frontocentral event-related potentials suggests that nicotine acts at later stages of target processing.

  2. “Neural Efficiency” of Athletes’ Brain during Visuo-Spatial Task: An fMRI Study on Table Tennis Players

    Directory of Open Access Journals (Sweden)

    Zhiping Guo

    2017-04-01

    Full Text Available Long-term training leads experts to develop a focused and efficient organization of task-related neural networks. “Neural efficiency” hypothesis posits that neural activity is reduced in experts. Here we tested the following working hypotheses: compared to non-athletes, athletes showed lower cortical activation in task-sensitive brain areas during the processing of sports related and sports unrelated visuo-spatial tasks. To address this issue, cortical activation was examined with fMRI in 14 table tennis athletes and 14 non-athletes while performing the visuo-spatial tasks. Behavioral results showed that athletes reacted faster than non-athletes during both types of the tasks, and no accuracy difference was found between athletes and non-athletes. fMRI data showed that, athletes exhibited less brain activation than non-athletes in the bilateral middle frontal gyrus, right middle orbitofrontal area, right supplementary motor area, right paracentral lobule, right precuneus, left supramarginal gyrus, right angular gyrus, left inferior temporal gyrus, left middle temporal gyrus, bilateral lingual gyrus and left cerebellum crus. No region was significantly more activated in the athletes than in the non-athletes. These findings possibly suggest that long-standing training prompt athletes develop a focused and efficient organization of task-related neural networks, as a possible index of “neural efficiency” in athletes engaged in visuo-spatial tasks, and this functional reorganization is possibly task-specific.

  3. Factors Influencing Learner Conceptions of Force: Exploring the Interaction among Visuospatial Ability, Motivation, and Conceptions of Newtonian Mechanics in University Undergraduates from an Evolutionary Perspective

    Science.gov (United States)

    Vallett, David Bruce

    This study examined the relationships among visuospatial ability, motivation to learn science, and learner conceptions of force across commonly measured demographics with university undergraduates with the aim of examining the support for an evolved sense of force and motion. Demographic variables of interest included age, ethnicity, and gender, which served to determine the ubiquity of the effects of the exogenous variables. Participants (n=91) self selected from introductory physics courses at a large public university in the Mid-Atlantic region of the United States. Utilizing a single-group exploratory design, all participants completed a series of anonymous online instruments to assess the variables of interest. Analysis consisted of an ANOVA for significance testing of demographic variables and a single-level structural equation model (SEM) to ascertain the causal influence of visuospatial ability and affect in the form of motivation on learner conceptions of force. Results of the SEM indicated that while motivation had a nonsignificant (p>.05) impact with this sample, visuospatial ability had a strong (.5 unit change in physics achievement per unit of VSA, pmechanics. The results of this study inform physics educators as to the factors underlying conceptual change in Newtonian physics and generate hypotheses regarding the cognitive processes and corresponding neural substrates associated with successful Newtonian reasoning.

  4. In Planta Processing and Glycosylation of a Nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-Like Effector and Its Interaction with a Host CLAVATA2-Like Receptor to Promote Parasitism1[OPEN

    Science.gov (United States)

    Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S.; Mitchum, Melissa G.

    2015-01-01

    Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. PMID:25416475

  5. The roles of the central executive and visuospatial storage in mental arithmetic: a comparison across strategies.

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    Hubber, Paula J; Gilmore, Camilla; Cragg, Lucy

    2014-05-01

    Previous research has demonstrated that working memory plays an important role in arithmetic. Different arithmetical strategies rely on working memory to different extents-for example, verbal working memory has been found to be more important for procedural strategies, such as counting and decomposition, than for retrieval strategies. Surprisingly, given the close connection between spatial and mathematical skills, the role of visuospatial working memory has received less attention and is poorly understood. This study used a dual-task methodology to investigate the impact of a dynamic spatial n-back task (Experiment 1) and tasks loading the visuospatial sketchpad and central executive (Experiment 2) on adults' use of counting, decomposition, and direct retrieval strategies for addition. While Experiment 1 suggested that visuospatial working memory plays an important role in arithmetic, especially when counting, the results of Experiment 2 suggested this was primarily due to the domain-general executive demands of the n-back task. Taken together, these results suggest that maintaining visuospatial information in mind is required when adults solve addition arithmetic problems by any strategy but the role of domain-general executive resources is much greater than that of the visuospatial sketchpad.

  6. A Neural Mechanism for Surprise-related Interruptions of Visuospatial Working Memory.

    Science.gov (United States)

    Wessel, Jan R

    2016-11-30

    Surprising perceptual events recruit a fronto-basal ganglia mechanism for inhibition, which suppresses motor activity following surprise. A recent study found that this inhibitory mechanism also disrupts the maintenance of verbal working memory (WM) after surprising tones. However, it is unclear whether this same mechanism also relates to surprise-related interruptions of non-verbal WM. We tested this hypothesis using a change-detection task, in which surprising tones impaired visuospatial WM. Participants also performed a stop-signal task (SST). We used independent component analysis and single-trial scalp-electroencephalogram to test whether the same inhibitory mechanism that reflects motor inhibition in the SST relates to surprise-related visuospatial WM decrements, as was the case for verbal WM. As expected, surprising tones elicited activity of the inhibitory mechanism, and this activity correlated strongly with the trial-by-trial level of surprise. However, unlike for verbal WM, the activity of this mechanism was unrelated to visuospatial WM accuracy. Instead, inhibition-independent activity that immediately succeeded the inhibitory mechanism was increased when visuospatial WM was disrupted. This shows that surprise-related interruptions of visuospatial WM are not effected by the same inhibitory mechanism that interrupts verbal WM, and instead provides evidence for a 2-stage model of distraction.

  7. Looking into learning: visuospatial and psychomotor predictors of ultrasound-guided procedural performance.

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    Smith, Hugh M; Kopp, Sandra L; Johnson, Rebecca L; Long, Timothy R; Cerhan, Jane H; Hebl, James R

    2012-01-01

    Despite widespread use of ultrasound in regional anesthesia, little understanding of the psychomotor and visuospatial skills required to achieve and maintain procedural proficiency exists. Despite its procedural nature, anesthesiology lags behind other fields in assessing technical aptitude among practitioners and trainees. The goals of this study were to measure relevant visuospatial and psychomotor aptitudes of anesthesia residents-in-training and to evaluate the relationship between these skill sets and the performance of ultrasound-guided regional anesthesia. Forty residents from the Mayo Clinic Department of Anesthesiology were enrolled, and 39 (PGY-1 through PGY-4) voluntarily completed a demographic survey, 4 psychomotor and 4 visuospatial aptitude assessments, and an ultrasound-based performance assessment. The Block Design Test, a subtest of the Wechsler Adult Intelligent Scale - III, correlated with ultrasound guided skill performance (correlation coefficient, 0.47; P hand-eye coordination visual feedback (projected image) compared with direct hand-eye coordination (P hand dominance. This study reveals that visuospatial aptitude is a better predictor of ultrasound-based procedural performance than psychomotor ability. The type of real-time visual feedback (indirect versus direct) used for hand-eye coordination significantly impacts procedural performance and has implications for anesthesia and other procedural specialties. The learning effect noted during initial ultrasound skill trials suggests visuospatial assimilation and underscores the importance of early ultrasound instruction.

  8. Visuo-spatial construction in patients with frontal and parietal lobe lesions

    Directory of Open Access Journals (Sweden)

    Himani Kashyap

    2011-04-01

    Full Text Available Visuospatial construction, traditionally viewed as a putative parietal function, also requires sustained attention, planning, organization strategies and error correction, and hence frontal lobe mediation. The relative contributions of the frontal and parietal lobes are poorly understood. To examine the contributions of parietal, frontal lobes, as well as right and left cerebral hemispheres to visuospatial construction. The Stick Construction Test for two-dimensional construction and the Block Construction Test for three-dimensional construction were administered pre-surgically to patients with lesions in the parietal lobe (n =9 and the frontal lobe (n=11, along with normal control subjects (n =20 matched to the patients on age (+/- 3 years, gender, education (+/- 3 years and handedness. The patients were significantly slower than the controls on both two-dimensional and three-dimensional tests. Patients with parietal lesions were slower than those with frontal lesions on the test of three-dimensional construction. Within each lobe patients with right and left sided lesions did not differ significantly. It appears that tests of three-dimensional construction might be most sensitive to visuospatial construction deficits. Visuospatial construction involves the mediation of both frontal and parietal lobes. The function does not appear to be lateralized. The networks arising from the parieto-occipital areas and projecting to the frontal cortices (e.g., occipito-frontal fasciculus may be the basis of the mediation of both lobes in visuospatial construction. The present findings need replication from studies with larger sample sizes.

  9. Correlation of Visuospatial Ability and EEG Slowing in Patients with Parkinson's Disease

    Science.gov (United States)

    Meyer, Antonia; Chaturvedi, Menorca; Hatz, Florian; Gschwandtner, Ute

    2017-01-01

    Background. Visuospatial dysfunction is among the first cognitive symptoms in Parkinson's disease (PD) and is often predictive for PD-dementia. Furthermore, cognitive status in PD-patients correlates with quantitative EEG. This cross-sectional study aimed to investigate the correlation between EEG slowing and visuospatial ability in nondemented PD-patients. Methods. Fifty-seven nondemented PD-patients (17 females/40 males) were evaluated with a comprehensive neuropsychological test battery and a high-resolution 256-channel EEG was recorded. A median split was performed for each cognitive test dividing the patients sample into either a normal or lower performance group. The electrodes were split into five areas: frontal, central, temporal, parietal, and occipital. A linear mixed effects model (LME) was used for correlational analyses and to control for confounding factors. Results. Subsequently, for the lower performance, LME analysis showed a significant positive correlation between ROCF score and parietal alpha/theta ratio (b = .59, p = .012) and occipital alpha/theta ratio (b = 0.50, p = .030). No correlations were found in the group of patients with normal visuospatial abilities. Conclusion. We conclude that a reduction of the parietal alpha/theta ratio is related to visuospatial impairments in PD-patients. These findings indicate that visuospatial impairment in PD-patients could be influenced by parietal dysfunction. PMID:28348918

  10. Preexisting semantic representation improves working memory performance in the visuospatial domain.

    Science.gov (United States)

    Rudner, Mary; Orfanidou, Eleni; Cardin, Velia; Capek, Cheryl M; Woll, Bencie; Rönnberg, Jerker

    2016-05-01

    Working memory (WM) for spoken language improves when the to-be-remembered items correspond to preexisting representations in long-term memory. We investigated whether this effect generalizes to the visuospatial domain by administering a visual n-back WM task to deaf signers and hearing signers, as well as to hearing nonsigners. Four different kinds of stimuli were presented: British Sign Language (BSL; familiar to the signers), Swedish Sign Language (SSL; unfamiliar), nonsigns, and nonlinguistic manual actions. The hearing signers performed better with BSL than with SSL, demonstrating a facilitatory effect of preexisting semantic representation. The deaf signers also performed better with BSL than with SSL, but only when WM load was high. No effect of preexisting phonological representation was detected. The deaf signers performed better than the hearing nonsigners with all sign-based materials, but this effect did not generalize to nonlinguistic manual actions. We argue that deaf signers, who are highly reliant on visual information for communication, develop expertise in processing sign-based items, even when those items do not have preexisting semantic or phonological representations. Preexisting semantic representation, however, enhances the quality of the gesture-based representations temporarily maintained in WM by this group, thereby releasing WM resources to deal with increased load. Hearing signers, on the other hand, may make strategic use of their speech-based representations for mnemonic purposes. The overall pattern of results is in line with flexible-resource models of WM.

  11. Normal aging increases discriminal dispersion in visuospatial short-term memory.

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    Noack, Hannes; Lövdén, Martin; Lindenberger, Ulman

    2012-09-01

    Computational models of cognitive aging propose that age-related decrements in cognitive performance, including short-term memory (STM), result from less distinct stimulus representations. When applied to visual STM, these models predict higher discriminal dispersion (L. L. Thurstone, 1927, Psychophysical analysis, The American Journal of Psychology, 38, 368-389.) in older adults than in younger adults. To test this prediction, we used a change-detection paradigm for visuospatial locations, with different levels of cognitive load (one, three, or five items) and retention interval (100 or 1,000 ms). Adult age differences were not reliable at Load 1, but were substantial at Loads 3 and 5. Effects of retention time did not differ across age groups, suggesting that age-related differences originated mainly from early processing stages. Applying a mixture model to the data revealed age-related increases in discriminal dispersion and decreases in asymptotic discrimination performance (indexing STM capacity). We concluded that age-related declines in discriminal dispersion, in addition to increasing capacity limitations, impair visual STM performance with advancing adult age.

  12. Behavioral and electrophysiological evidence of opposing lateral visuospatial asymmetries in the upper and lower visual fields.

    Science.gov (United States)

    Loughnane, Gerard M; Shanley, John P; Lalor, Edmund C; O'Connell, Redmond G

    2015-02-01

    Neurologically healthy individuals typically exhibit a subtle bias towards the left visual field during spatial judgments, known as "pseudoneglect". However, it has yet to be reliably established if the direction and magnitude of this lateral bias varies along the vertical plane. Here, participants were required to distribute their attention equally across a checkerboard array spanning the entire visual field in order to detect transient targets that appeared at unpredictable locations. Reaction times (RTs) were faster to left hemifield targets in the lower visual field but the opposite trend was observed for targets in the upper field. Electroencephalogram (EEG) analyses focused on the interval prior to target onset in order to identify endogenous neural correlates of these behavioral asymmetries. The relative hemispheric distribution of pre-target oscillatory alpha power was predictive of RT bias to targets in the lower visual field but not the upper field, indicating separate attentional mechanisms for the upper and lower visual fields. Analysis of multifocal visual-evoked potentials (MVEP) in the pre-target interval also indicated that the opposing upper and lower field asymmetries may impact on the magnitude of primary visual cortical responses. These results provide new evidence of a functional segregation of upper and lower field visuospatial processing.

  13. Hemispheric biases and the control of visuospatial attention: an ERP study

    Directory of Open Access Journals (Sweden)

    Banich Marie T

    2005-08-01

    Full Text Available Abstract Background We examined whether individual differences in hemispheric utilization can interact with the intrinsic attentional biases of the cerebral hemispheres. Evidence suggests that the hemispheres have competing biases to direct attention contralaterally, with the left hemisphere (LH having a stronger bias than the right hemisphere. There is also evidence that individuals have characteristic biases to utilize one hemisphere more than the other for processing information, which can induce a bias to direct attention to contralateral space. We predicted that LH-biased individuals would display a strong rightward attentional bias, which would create difficulty in selectively attending to target stimuli in the left visual field (LVF as compared to right in the performance of a bilateral flanker task. Results Consistent with our hypothesis, flanker interference effects were found on the N2c event-related brain potential and error rate for LH-biased individuals in the Attend-LVF condition. The error rate effect was correlated with the degree of hemispheric utilization bias for the LH-Bias group. Conclusion We conclude that hemispheric utilization bias can enhance a hemisphere's contralateral attentional bias, at least for individuals with a LH utilization bias. Hemispheric utilization bias may play an important and largely unrecognized role in visuospatial attention.

  14. Effects of categorical representation on visuospatial working memory in autism spectrum disorder.

    Science.gov (United States)

    Carmo, Joana C; Souza, Cristiane; Gonçalves, Filipe; Pinho, Sandra; Filipe, Carlos N; Lachmann, Thomas

    2017-03-01

    We tested whether individuals with autism spectrum disorder (ASD) are impaired in visuospatial working memory or in the use of the semantic system, in particular in categorization processes at the service of working memory. The performance of high-functioning individuals with ASD (N = 21) in a visual same-different task adapted from Lachmann and van Leeuwen [e.g., Lachmann, T., & van Leeuwen, C. (2010). Representational economy, not processing speed, determines preferred processing strategy of visual patterns. Acta Psychologica, 134(3), 290-298] was compared to those of typically developed controls (N = 25). In a categorical identity task, two successive patterns had to be judged as the same if they belonged to the same equivalence set (cf. Garner, W. R., & Clement, D. E. (1963). Goodness of pattern and pattern uncertainty. Journal of Verbal Learning and Verbal Behavior, 2, 446-452), including all possible rotation and reflection transformations (R&R category), and as different otherwise. In a physical identity task, only patterns that matched in both shape and orientation had to be responded to as the same; all others, including category matches, had to be classified as different. Equivalence sets had different sizes (ESS). Earlier studies showed an increase in reaction time (RT) with increasing ESS and, for the physical identity task, a response conflict for category matching. Both of these effects were interpreted as evidence for a categorical code by which individual patterns are mentally represented. Assuming that categorization processes are deficient in individuals with ASD, we expected no ESS effects and, in the physical identity task, absence of a response conflict for these individuals. In contrast, we found individuals with ASD to be generally as sensitive to ESS as controls, and they showed a response conflict in the physical identity task. Thus, categorical processing seems to be intact in ASD. However, a strong overall group effect was found in RTs

  15. Children’s visuospatial memory predicts mathematics achievement through early adolescence

    Science.gov (United States)

    Li, Yaoran

    2017-01-01

    A previous study showed that gains in visuospatial memory from first to fifth grade predicted end-of-fifth grade mathematics but not reading achievement, controlling other factors. In this follow up study, these relations were assessed from sixth to ninth grade, inclusive (n = 145). The results showed that growth in visuospatial memory across the elementary school years was related to growth in mathematics achievement after fifth grade, controlling intelligence, the central executive and phonological memory components of working memory, in-class attentive behavior, parental education, and fifth grade mathematics achievement. As found for fifth grade, this relation was not found for reading achievement after fifth grade. In total, the results suggest that visuospatial memory has a unique influence on ease of learning some types of mathematics and that this influence becomes more important across successive grades. PMID:28192484

  16. Where Were Those Rabbits? A New Paradigm to Determine Cerebral Lateralisation of Visuospatial Memory Function in Children

    Science.gov (United States)

    Groen, Margriet A.; Whitehouse, Andrew J. O.; Badcock, Nicholas A.; Bishop, Dorothy V. M.

    2011-01-01

    In the majority of people, functional differences are observed between the two cerebral hemispheres: language production is typically subserved by the left hemisphere and visuospatial skills by the right hemisphere. The development of this division of labour is not well understood and lateralisation of visuospatial function has received little…

  17. The Differential Contributions of Auditory-Verbal and Visuospatial Working Memory on Decoding Skills in Children Who Are Poor Decoders

    Science.gov (United States)

    Squires, Katie Ellen

    2013-01-01

    This study investigated the differential contribution of auditory-verbal and visuospatial working memory (WM) on decoding skills in second- and fifth-grade children identified with poor decoding. Thirty-two second-grade students and 22 fifth-grade students completed measures that assessed simple and complex auditory-verbal and visuospatial memory,…

  18. The rise and fall of immediate and delayed memory for verbal and visuospatial information from late childhood to late adulthood

    NARCIS (Netherlands)

    Murre, J.M.J.; Janssen, S.M.J.; Rouw, R.; Meeter, M.

    2013-01-01

    Over 100,000 verbal and visuospatial immediate and delayed memory tests were presented via the Internet to over 28,000 participants in the age range of 11 to 80. Structural equation modeling pointed to the verbal versus visuospatial dimension as an important factor in individual differences, but not

  19. Brief report: visuo-spatial guidance of movement during gesture imitation and mirror drawing in children with autism spectrum disorders.

    Science.gov (United States)

    Salowitz, Nicole M G; Eccarius, Petra; Karst, Jeffrey; Carson, Audrey; Schohl, Kirsten; Stevens, Sheryl; Van Hecke, Amy Vaughan; Scheidt, Robert A

    2013-04-01

    Thirteen autistic and 14 typically developing children (controls) imitated hand/arm gestures and performed mirror drawing; both tasks assessed ability to reorganize the relationship between spatial goals and the motor commands needed to acquire them. During imitation, children with autism were less accurate than controls in replicating hand shape, hand orientation, and number of constituent limb movements. During shape tracing, children with autism performed accurately with direct visual feedback, but when viewing their hand in a mirror, some children with autism generated fewer errors than controls whereas others performed much worse. Large mirror drawing errors correlated with hand orientation and hand shape errors in imitation, suggesting that visuospatial information processing deficits may contribute importantly to functional motor coordination deficits in autism.

  20. Influence of age and sex on line bisection: a study of normal performance with implications for visuospatial neglect.

    Science.gov (United States)

    Varnava, Alice; Halligan, Peter W

    2007-11-01

    Line bisection is an established clinical task used to diagnose visuospatial neglect. To date, few studies have considered the extent to which age and sex as background variables contribute to bisection performance. Both variables affect the neural substrates underlying cognitive processes and hence the behavioural performance of bisection. The purpose of this study was to examine the effects of age and sex on normal bisection performance, using three different line lengths to elucidate the influence of these potential contributing factors. Seventy men and 70 women, divided equally into seven age-cohorts between 14 and 80 years, bisected lines. Results indicated clear age- and sex-related differences both in the magnitude and direction of bisection deviations across the three line lengths. Differences are discussed in terms of neural changes across the adult lifespan including hemispheric differences and hormonally mediated changes.

  1. An fMRI study on variation of visuospatial cognitive performance of young male due to highly concentrated oxygen administration

    Science.gov (United States)

    Chung, Soon Cheol; Kim, Ik Hyeon; Tack, Gye Rae; Sohn, Jin Hun

    2004-04-01

    This study investigated the effects of 30% oxygen administration on the visuospatial cognitive performance using fMRI. Eight college students (right-handed, average age 23.5) were selected as subjects for this study. Oxygen supply equipment which gives 21% and 30% oxygen at a constant rate of 8L/min was developed for this study. To measure the performance of visuospatial cognition, two questionnaires with similar difficulty containing 20 questions each were also developed. Experiment was designed as two runs: run for visuospatial cognition test with normal air (21% of oxygen) and run for visuospatial cognition test with highly concentrated air (30% of oxygen). Run consists of 4 blocks and each block has 8 control problems and 5 visuospatial problems. Functional brain images were taken from 3T MRI using single-shot EPI method. Activities of neural network due to performing visuospatial cognition test were identified using subtraction procedure, and activation areas while performing visuospatial cognition test were extracted using double subtraction procedure. Activities were observed at occipital lobe, parietal lobe, and frontal lobe when performing visuospatial cognition test following both 21% and 30% oxygen administration. But in case of only 30% oxygen administration there were more activities at left precuneus, left cuneus, right postcentral gyrus, bilateral middle frontal gyri, right inferior frontal gyrus, left superior frontal gyrus, bilateral uvula, bilateral pyramis, and nodule compared with 21% oxygen administration. From results of visuospatial cognition test, accuracy rate increased in case of 30% oxygen administration. Thus it could be concluded that highly concentrated oxygen administration has positive effects on the visuospatial cognitive performance.

  2. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  3. Reduced surround inhibition in musicians.

    Science.gov (United States)

    Shin, Hae-Won; Kang, Suk Y; Hallett, Mark; Sohn, Young H

    2012-06-01

    To investigate whether surround inhibition (SI) in the motor system is altered in professional musicians, we performed a transcranial magnetic stimulation (TMS) study in 10 professional musicians and 15 age-matched healthy non-musicians. TMS was set to be triggered by self-initiated flexion of the index finger at different intervals ranging from 3 to 1,000 ms. Average motor evoked potential (MEP) amplitudes obtained from self-triggered TMS were normalized to average MEPs of the control TMS at rest and expressed as a percentage. Normalized MEP amplitudes of the abductor digiti minimi (ADM) muscles were compared between the musicians and non-musicians with the primary analysis being the intervals between 3 and 80 ms (during the movement). A mixed-design ANOVA revealed a significant difference in normalized ADM MEPs during the index finger flexion between groups, with less SI in the musicians. This study demonstrated that the functional operation of SI is less strong in musicians than non-musicians, perhaps due to practice of movement synergies involving both muscles. Reduced SI, however, could lead susceptible musicians to be prone to develop task-specific dystonia.

  4. Binaural Rendering in MPEG Surround

    Science.gov (United States)

    Breebaart, Jeroen; Villemoes, Lars; Kjörling, Kristofer

    2008-12-01

    This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial) properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate "binaural parameters" that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  5. Impact of acute aerobic exercise and cardiorespiratory fitness on visuospatial attention performance and serum BDNF levels.

    Science.gov (United States)

    Tsai, Chia-Liang; Chen, Fu-Chen; Pan, Chien-Yu; Wang, Chun-Hao; Huang, Tsang-Hai; Chen, Tzu-Chi

    2014-03-01

    The purpose of the current study was to explore various behavioral and neuroelectric indices after acute aerobic exercise in young adults with different cardiorespiratory fitness levels when performing a cognitive task, and also to gain a mechanistic understanding of the effects of such exercise using the brain-derived neurotrophic factor (BDNF) biochemical index. Sixty young adults were separated into one non-exercise-intervention and two exercise intervention (EI) (i.e., EIH: higher-fit and EIL: lower-fit) groups according to their maximal oxygen consumption. The participants' cognitive performances (i.e., behavioral and neuroelectric indices via an endogenous visuospatial attention task test) and serum BDNF levels were measured at baseline and after either an acute bout of 30min of moderate intensity aerobic exercise or a control period. Analyses of the results revealed that although acute aerobic exercise decreased reaction times (RTs) and increased the central Contingent Negative Variation (CNV) area in both EI groups, only the EIH group showed larger P3 amplitude and increased frontal CNV area after acute exercise. Elevated BDNF levels were shown after acute exercise for both EI groups, but this was not significantly correlated with changes in behavioral and neuroelectric performances for either group. These results suggest that both EI groups could gain response-related (i.e., RT and central CNV) benefits following a bout of moderate acute aerobic exercise. However, only higher-fit individuals could obtain particular cognition-process-related efficiency with regard to attentional resource allocation (i.e., P3 amplitude) and cognitive preparation processes (i.e., frontal CNV) after acute exercise, implying that the mechanisms underlying the effects of such exercise on neural functioning may be fitness dependent. However, the facilitating effects found in this work could not be attributed to the transient change in BDNF levels after acute exercise.

  6. Visuospatial Working Memory in Toddlers with a History of Periventricular Leukomalacia: An EEG Narrow-Band Power Analysis

    Science.gov (United States)

    García-Gomar, María Luisa; Santiago-Rodríguez, Efraín; Rodríguez-Camacho, Mario; Harmony, Thalía

    2013-01-01

    Background Periventricular Leukomalacia (PVL) affects white matter, but grey matter injuries have also been reported, particularly in the dorsomedial nucleus and the cortex. Both structures have been related to working memory (WM) processes. The aim of this study was to compare behavioral performances and EEG power spectra during a visuospatial working memory task (VSWMT) of toddlers with a history of PVL and healthy toddlers. Methodology/Principal Findings A prospective, comparative study of WM was conducted in toddlers with a history of PVL and healthy toddlers. The task responses and the EEG narrow-band power spectra during a VSWMT were compared in both groups. The EEG absolute power was analyzed during the following three conditions: baseline, attention and WM retention. The number of correct responses was higher in the healthy group (20.5±5.0) compared to the PVL group (16.1±3.9) (p = 0.04). The healthy group had absolute power EEG increases (p≤0.05) during WM compared to the attention condition in the bilateral frontal and right temporal, parietal and occipital regions in frequencies ranging from 1.17 to 2.34 Hz and in the right temporal, parietal and occipital regions in frequencies ranging from 14.06 to 15.23 Hz. In contrast, the PVL group had absolute power increases (p≤0.05) in the bilateral fronto-parietal, left central and occipital regions in frequencies that ranged from 1.17 to 3.52 Hz and in the bilateral frontal and right temporal regions in frequencies ranging from 9.37 to 19.14 Hz. Conclusions/Significance This study provides evidence that PVL toddlers have visuospatial WM deficits and a very different pattern of absolute power increases compared to a healthy group of toddlers, with greater absolute power in the low frequency range and widespread neuronal networks in the WM retention phase. PMID:23922816

  7. Young adult male carriers of the fragile X premutation exhibit genetically modulated impairments in visuospatial tasks controlled for psychomotor speed

    Directory of Open Access Journals (Sweden)

    Wong Ling M

    2012-11-01

    Full Text Available Abstract Background A previous study reported enhanced psychomotor speed, and subtle but significant cognitive impairments, modulated by age and by mutations in the fragile X mental retardation 1 (FMR1 gene in adult female fragile X premutation carriers (fXPCs. Because male carriers, unlike females, do not have a second, unaffected FMR1 allele, male fXPCs should exhibit similar, if not worse, impairments. Understanding male fXPCs is of particular significance because of their increased risk of developing fragile X-associated tremor/ataxia syndrome (FXTAS. Methods Male fXPCs (n = 18 and healthy control (HC adults (n = 26 aged less than 45 years performed two psychomotor speed tasks (manual and oral and two visuospatial tasks (magnitude comparison and enumeration. In the magnitude comparison task, participants were asked to compare and judge which of two bars was larger. In the enumeration task, participants were shown between one and eight green bars in the center of the screen, and asked to state the total number displayed. Enumeration typically proceeds in one of two modes: subitizing, a fast and accurate process that works only with a small set of items, and counting, which requires accurate serial-object detection and individuation during visual search. We examined the associations between the performance on all tasks and the age, full-scale intelligent quotient, and CGG repeat length of participants. Results We found that in the magnitude comparison and enumeration tasks, male fXPCs exhibited slower reaction times relative to HCs, even after controlling for simple reaction time. Conclusions Our results indicate that male fXPCs as a group show impairments (slower reaction times in numerical visuospatial tasks, which are consistent with previous findings. This adds to a growing body of literature characterizing the phenotype in fXPCs who are asymptomatic for FXTAS. Future longitudinal studies are needed to determine how these impairments

  8. Reliability of a novel paradigm for determining hemispheric lateralization of visuospatial function

    NARCIS (Netherlands)

    Whitehouse, A.J.O.; Badcock, N.A.; Groen, M.A.; Bishop, D.V.M.

    2009-01-01

    In most individuals, language production and visuospatial skills are subserved predominantly by the left and right hemispheres, respectively. Functional Transcranial Doppler (fTCD) provides a noninvasive and relatively low-cost method for measuring functional lateralization. However, while the silen

  9. A Familiar Pattern? Semantic Memory Contributes to the Enhancement of Visuo-Spatial Memories

    Science.gov (United States)

    Riby, Leigh M.; Orme, Elizabeth

    2013-01-01

    In this study we quantify for the first time electrophysiological components associated with incorporating long-term semantic knowledge with visuo-spatial information using two variants of a traditional matrix patterns task. Results indicated that the matrix task with greater semantic content was associated with enhanced accuracy and RTs in a…

  10. Visuospatial Working Memory in Intuitive Geometry, and in Academic Achievement in Geometry

    Science.gov (United States)

    Giofre, David; Mammarella, Irene C.; Ronconi, Lucia; Cornoldi, Cesare

    2013-01-01

    A study was conducted on the involvement of visuospatial working memory (VSWM) in intuitive geometry and in school performance in geometry at secondary school. A total of 166 pupils were administered: (1) six VSWM tasks, comprising simple storage and complex span tasks; and (2) the intuitive geometry task devised by Dehaene, Izard, Pica, and…

  11. The impact of developmental visuospatial learning difficulties on British Sign Language.

    Science.gov (United States)

    Atkinson, J R; Woll, B; Gathercole, S

    2002-01-01

    There has been substantial research interest in recent years in the relationship between the development of language and cognition, especially where dissociations can be seen between them. Williams syndrome, a rare congenital disorder characterized by a fractionation of higher cortical functions, with relatively preserved language but marked difficulties with visuospatial constructive cognition, has been extensively studied. The case of Heather, who is remarkably similar to the characteristic phenotype of Williams syndrome in physical appearance and cognitive abilities, but who is also congenitally deaf and a user of British Sign Language, provides the first opportunity to explore the consequences of specific visuospatial learning difficulties on the linguistic system when the language used is visuospatial. Heather shows a pattern of impaired drawing ability and visual form discrimination, but preserved ability to discriminate faces. She has a large vocabulary in British Sign Language, and overall presents a picture of relative competence in British Sign Language grammar. However, she shows specific deficits in those areas of British Sign Language which directly rely on spatial representations for linguistic purposes. A number of theories as to the nature of her impairments and those found in Williams syndrome are discussed, using models of the relationship between language and visuospatial cognition based on data from this unique case.

  12. Motor functioning, exploration, visuospatial cognition and language development in preschool children with autism

    NARCIS (Netherlands)

    Hellendoorn, Annika; Wijnroks, Lex; van Daalen, Emma; Dietz, Claudine; Buitelaar, Jan K.; Leseman, Paul

    2015-01-01

    In order to understand typical and atypical developmental trajectories it is important to assess how strengths or weaknesses in one domain may be affecting performance in other domains. This study examined longitudinal relations between early fine motor functioning, visuospatial cognition, explorati

  13. The Influence of Test Mode and Visuospatial Ability on Mathematics Assessment Performance

    Science.gov (United States)

    Logan, Tracy

    2015-01-01

    Mathematics assessment and testing are increasingly situated within digital environments with international tests moving to computer-based testing in the near future. This paper reports on a secondary data analysis which explored the influence the mode of assessment--computer-based (CBT) and pencil-and-paper based (PPT)--and visuospatial ability…

  14. Visuospatial Working Memory in ADHD Patients, Unaffected Siblings, and Healthy Controls

    NARCIS (Netherlands)

    van Ewijk, Hanneke; Heslenfeld, Dirk J.; Luman, Marjolein; Rommelse, Nanda N.; Hartman, Catharina A.; Hoekstra, Pieter; Franke, Barbara; Buitelaar, Jan K.; Oosterlaan, Jaap

    2014-01-01

    Objective: The aim of this study was to (a) test the usefulness of visuospatial working memory (VSWM) as an endophenotype for ADHD and (b) study the developmental trajectory of VSWM in ADHD. Method: A total of 110 ADHD patients, 60 unaffected siblings, and 109 controls, aged 8 to 29 years, were asse

  15. The decline of verbal and visuospatial working memory across the adult life span.

    Science.gov (United States)

    Cansino, Selene; Hernández-Ramos, Evelia; Estrada-Manilla, Cinthya; Torres-Trejo, Frine; Martínez-Galindo, Joyce Graciela; Ayala-Hernández, Mariana; Gómez-Fernández, Tania; Osorio, David; Cedillo-Tinoco, Melisa; Garcés-Flores, Lissete; Beltrán-Palacios, Karla; García-Lázaro, Haydée Guadalupe; García-Gutiérrez, Fabiola; Cadena-Arenas, Yadira; Fernández-Apan, Luisa; Bärtschi, Andrea; Rodríguez-Ortiz, María Dolores

    2013-12-01

    It has been well established that working memory abilities decrease with advancing age; however, the specific time point in the adult life span at which this deficit begins and the rate at which it advances are still controversial. There is no agreement on whether working memory declines equally for visuospatial and verbal information, and the literature disagrees on how task difficulty may influence this decay. We addressed these questions in a lifespan sample of 1,500 participants between 21 and 80 years old. The n-back task was used, with letters and circles presented at different positions around an imaginary circle, to evaluate working memory in the verbal and visuospatial domains, respectively. The participants' task was to judge whether the current stimulus matched a stimulus that was shown n trials prior. Both domains were evaluated in two levels of difficulty: 1-back and 2-back. The comparison across decades showed that discrimination in the visuospatial and 1-back tasks started to decline earlier in women than in men; however, discrimination was equal between the sexes in the verbal and 2-back tasks. Performance on tasks in the visuospatial domain exhibited more pronounced decline than in those in the verbal domain. The rate of decline in working memory accuracy was superior in 2-back tasks than in 1-back tasks, independent of the domain. These results revealed that the effects of aging on working memory are less dependent on the type of information and more reliant on the resources demanded by the task.

  16. Effect of Musical Expertise on Visuospatial Abilities: Evidence from Reaction Times and Mental Imagery

    Science.gov (United States)

    Brochard, Renaud; Dufour, Andre; Despres, Olivier

    2004-01-01

    Recently, the relationship between music and nonmusical cognitive abilities has been highly debated. It has been documented that formal music training would improve verbal, mathematical or visuospatial performance in children. In the experiments described here, we tested if visual perception and imagery abilities were enhanced in adult musicians…

  17. Stereotype Threat and Gender Differences in Performance on a Novel Visuospatial Task

    Science.gov (United States)

    Campbell, Susan Miller; Collaer, Marcia L.

    2009-01-01

    Stereotype threat research has shown that being a member of a negatively stereotyped group may result in impaired performance on tests of skills thought to be relevant to the stereotype. This study investigated whether stereotype threat influences gender differences in performance on a novel test of visuospatial ability. Undergraduates (N = 194)…

  18. Is Visuospatial Hemineglect Longitudinally Associated With Postural Imbalance in the Postacute Phase of Stroke?

    NARCIS (Netherlands)

    van Nes, Ilse J. W.; van Kessel, Marlies E.; Schils, Fanny; Fasotti, Luciano; Geurts, Alexander C. H.; Kwakkel, Gert

    2009-01-01

    Introduction. The purpose of this study was to determine the longitudinal association of visuospatial hemineglect with postural imbalance in postacute stroke patients and to establish whether this relationship is confounded by other determinants. Methods. A prospective cohort study of 53 postacute s

  19. Neural correlates of visuospatial working memory in attention-deficit/hyperactivity disorder and healthy controls

    NARCIS (Netherlands)

    van Ewijk, Hanneke; Weeda, Wouter D.; Heslenfeld, Dirk J.; Luman, Marjolein; Hartman, Catharina A.; Hoekstra, Pieter J.; Faraone, Stephen V.; Franke, Barbara; Buitelaar, Jan K.; Oosterlaan, Jaap

    2015-01-01

    Impaired visuospatial working memory (VSWM) is suggested to be a core neurocognitive deficit in attention-deficit/hyperactivity disorder (ADHD), yet the underlying neural activation patterns are poorly understood. Furthermore, it is unclear to what extent age and gender effects may play a role in VS

  20. Is visuospatial hemineglect really a determinant of postural control following stroke? An acute-phase study.

    NARCIS (Netherlands)

    Nes, I.J.W. van; Linden, S. van der; Hendricks, H.T.; Kuijk, A.A. van; Rulkens, M.; Verhagen, W.I.; Geurts, A.C.H.

    2009-01-01

    OBJECTIVE: The purpose of this study was to determine the independent contribution of visuospatial hemineglect to impaired postural control in the acute phase (<2 weeks) of stroke compared with other possible clinical and biological determinants. METHODS: This study was conducted in 4 hospitals i

  1. Visuospatial Working Memory in Intuitive Geometry, and in Academic Achievement in Geometry

    Science.gov (United States)

    Giofre, David; Mammarella, Irene C.; Ronconi, Lucia; Cornoldi, Cesare

    2013-01-01

    A study was conducted on the involvement of visuospatial working memory (VSWM) in intuitive geometry and in school performance in geometry at secondary school. A total of 166 pupils were administered: (1) six VSWM tasks, comprising simple storage and complex span tasks; and (2) the intuitive geometry task devised by Dehaene, Izard, Pica, and…

  2. Is visuospatial hemineglect longitudinally associated with postural imbalance in the postacute phase of stroke?

    NARCIS (Netherlands)

    Nes, van I.C.; Kessel, van M.E.; Schils, F.; Fasotti, L.; Geurts, A.C.; Kwakkel, G.

    2009-01-01

    15%. RESULTS: Visuospatial hemineglect was significantly associated with BBS and FAC. The relation between hemineglect and both BBS and FAC was confounded by severity of paresis of the lower limb. After controlling for severity of paresis, hemineglect remained independently associated with BBS, wher

  3. Visuospatial and visuomotor deficits in preterm children : The involvement of cerebellar dysfunctioning

    NARCIS (Netherlands)

    Van Braeckel, Koenraad N. J. A.; Taylor, H. Gerry

    2013-01-01

    One of the more consistent findings in follow-up studies of preterm children is a deficit in visuospatial and visuomotor skills. Impairment of the dorsal visual stream and basal ganglia damage have been hypothesized to underlie this deficit. However, given recent findings of impaired cerebellar deve

  4. Visuospatial function in early Alzheimer's disease--the use of the Visual Object and Space Perception (VOSP battery.

    Directory of Open Access Journals (Sweden)

    Natália Bezerra Mota Quental

    Full Text Available Alzheimer's disease (AD is the most frequent cause of dementia. The clinical symptoms of AD begin with impairment of memory and executive function followed by the gradual involvement of other functions, such as language, semantic knowledge, abstract thinking, attention, and visuospatial abilities. Visuospatial function involves the identification of a stimulus and its location and can be impaired at the beginning of AD. The Visual Object and Space Perception (VOSP battery evaluates visuospatial function, while minimizing the interference of other cognitive functions.To evaluate visuospatial function in early AD patients using the VOSP and determine cutoff scores to differentiate between cognitively healthy individuals and AD patients.Thirty-one patients with mild AD and forty-four healthy elderly were evaluated using a neuropsychological battery and the VOSP.In the VOSP, the AD patients performed more poorly in all subtests examining object perception and in two subtests examining space perception (Number Location and Cube Analysis. The VOSP showed good accuracy and good correlation with tests measuring visuospatial function.Visuospatial function is impaired in the early stages of AD. The VOSP battery is a sensitive battery test for visuospatial deficits with minimal interference by other cognitive functions.

  5. Does cerebral lateralization develop? A study using functional transcranial Doppler ultrasound assessing lateralization for language production and visuospatial memory.

    Science.gov (United States)

    Groen, Margriet A; Whitehouse, Andrew J O; Badcock, Nicholas A; Bishop, Dorothy V M

    2012-05-01

    In the majority of people, language production is lateralized to the left cerebral hemisphere and visuospatial skills to the right. However, questions remain as to when, how, and why humans arrive at this division of labor. In this study, we assessed cerebral lateralization for language production and for visuospatial memory using functional transcranial Doppler ultrasound in a group of 60 typically developing children between the ages of six and 16 years. The typical pattern of left-lateralized activation for language production and right-lateralized activation for visuospatial memory was found in the majority of the children (58%). No age-related change in direction or strength of lateralization was found for language production. In contrast, the strength of lateralization (independent of direction) for visuospatial memory function continued to increase with age. In addition, boys showed a trend for stronger right-hemisphere lateralization for visuospatial memory than girls, but there was no gender effect on language laterality. We tested whether having language and visuospatial functions in the same hemisphere was associated with poor cognitive performance and found no evidence for this "functional crowding" hypothesis. We did, however, find that children with left-lateralized language production had higher vocabulary and nonword reading age-adjusted standard scores than other children, regardless of the laterality of visuospatial memory. Thus, a link between language function and left-hemisphere lateralization exists, and cannot be explained in terms of maturational change.

  6. Time-dependent approach for single trial classification of covert visuospatial attention

    Science.gov (United States)

    Tonin, L.; Leeb, R.; Millán, J. del R.

    2012-08-01

    Recently, several studies have started to explore covert visuospatial attention as a control signal for brain-computer interfaces (BCIs). Covert visuospatial attention represents the ability to change the focus of attention from one point in the space without overt eye movements. Nevertheless, the full potential and possible applications of this paradigm remain relatively unexplored. Voluntary covert visuospatial attention might allow a more natural and intuitive interaction with real environments as neither stimulation nor gazing is required. In order to identify brain correlates of covert visuospatial attention, classical approaches usually rely on the whole α-band over long time intervals. In this work, we propose a more detailed analysis in the frequency and time domains to enhance classification performance. In particular, we investigate the contribution of α sub-bands and the role of time intervals in carrying information about visual attention. Previous neurophysiological studies have already highlighted the role of temporal dynamics in attention mechanisms. However, these important aspects are not yet exploited in BCI. In this work, we studied different methods that explicitly cope with the natural brain dynamics during visuospatial attention tasks in order to enhance BCI robustness and classification performances. Results with ten healthy subjects demonstrate that our approach identifies spectro-temporal patterns that outperform the state-of-the-art classification method. On average, our time-dependent classification reaches 0.74 ± 0.03 of the area under the ROC (receiver operating characteristic) curve (AUC) value with an increase of 12.3% with respect to standard methods (0.65 ± 0.4). In addition, the proposed approach allows faster classification (<1 instead of 3 s), without compromising performances. Finally, our analysis highlights the fact that discriminant patterns are not stable for the whole trial period but are changing over short time

  7. Visuospatial viewpoint manipulation during full-body illusion modulates subjective first-person perspective.

    Science.gov (United States)

    Pfeiffer, Christian; Schmutz, Valentin; Blanke, Olaf

    2014-12-01

    Self-consciousness is based on multisensory signals from the body. In full-body illusion (FBI) experiments, multisensory conflict was used to induce changes in three key aspects of bodily self-consciousness (BSC): self-identification (which body 'I' identify with), self-location (where 'I' am located), and first-person perspective (from where 'I' experience the world; 1PP). Here, we adapted a previous FBI protocol in which visuotactile stroking was administered by a robotic device (tactile stroking) and simultaneously rendered on the back of a virtual body (visual stroking) that participants viewed on a head-mounted display as if filmed from a posterior viewpoint of a camera. We compared the effects of two different visuospatial viewpoints on the FBI and thereby on these key aspects of BSC. During control manipulations, participants saw a no-body object instead of a virtual body (first experiment) or received asynchronous versus synchronous visuotactile stroking (second experiment). Results showed that within-subjects visuospatial viewpoint manipulations affected the subjective 1PP ratings if a virtual body was seen but had no effect for viewing a non-body object. However, visuospatial viewpoint had no effect on self-identification, but depended on the viewed object and visuotactile synchrony. Self-location depended on visuospatial viewpoint (first experiment) and visuotactile synchrony (second experiment). Our results show that the visuospatial viewpoint from which the virtual body is seen during FBIs modulates the subjective 1PP and that such viewpoint manipulations contribute to spatial aspects of BSC. We compare the present data with recent data revealing vestibular contributions to the subjective 1PP and discuss the multisensory nature of BSC and the subjective 1PP.

  8. Mental representations derived from spatial descriptions: the influence of orientation specificity and visuospatial abilities.

    Science.gov (United States)

    Meneghetti, Chiara; Pazzaglia, Francesca; De Beni, Rossana

    2015-03-01

    This study aimed to investigate the orientation dependence effect and the role of visuospatial abilities in mental representations derived from spatial descriptions. The analysis focused on how the orientation effect and the involvement of visuospatial abilities change when survey and route descriptions are used, and the initial and main orientation of an imaginary tour. In Experiment 1, 48 participants listened to survey or route descriptions in which information was mainly north-oriented (matching the initial heading and main direction of travel expressed in the description). In Experiment 2, 40 participants listened to route descriptions in which the initial orientation (north-oriented) was mismatched with the main direction of travel (east-oriented). Participants performed pointing task while facing north vs south (Exp. 1 and 2), and while facing east vs west (Exp. 2), as well as a map drawing task and several visuospatial measures. In both experiments, the results showed that pointing was easier while facing north than while facing south, and map drawings were arranged with a north-up orientation (with no difference between survey and route descriptions). In Experiment 2, pointing while facing east was easier than in the other pointing conditions. The results obtained with the visuospatial tasks showed that perspective-taking (PT) skill was the main predictor of the ability to imagine positions misaligned with the direction expressed in the descriptions (i.e., pointing while facing south in Experiment 1; pointing while facing north, south or west in Experiment 2). Overall, these findings indicate that mental representations derived from spatial descriptions are specifically oriented and their orientation is influenced by the main direction of travel and by the initial orientation. These mental representations, and the adoption of counter-aligned imaginary orientations, demand visuospatial skills and PT ability in particular.

  9. An online EEG BCI based on covert visuospatial attention in absence of exogenous stimulation

    Science.gov (United States)

    Tonin, L.; Leeb, R.; Sobolewski, A.; Millán, J. del R.

    2013-10-01

    Objective. In this work we present—for the first time—the online operation of an electroencephalogram (EEG) brain-computer interface (BCI) system based on covert visuospatial attention (CVSA), without relying on any evoked responses. Electrophysiological correlates of pure top-down CVSA have only recently been proposed as a control signal for BCI. Such systems are expected to share the ease of use of stimulus-driven BCIs (e.g. P300, steady state visually evoked potential) with the autonomy afforded by decoding voluntary modulations of ongoing activity (e.g. motor imagery). Approach. Eight healthy subjects participated in the study. EEG signals were acquired with an active 64-channel system. The classification method was based on a time-dependent approach tuned to capture the most discriminant spectral features of the temporal evolution of attentional processes. The system was used by all subjects over two days without retraining, to verify its robustness and reliability. Main results. We report a mean online accuracy across the group of 70.6 ± 1.5%, and 88.8 ± 5.8% for the best subject. Half of the participants produced stable features over the entire duration of the study. Additionally, we explain drops in performance in subjects showing stable features in terms of known electrophysiological correlates of fatigue, suggesting the prospect of online monitoring of mental states in BCI systems. Significance. This work represents the first demonstration of the feasibility of an online EEG BCI based on CVSA. The results achieved suggest the CVSA BCI as a promising alternative to standard BCI modalities.

  10. Characterizing the Microenvironment Surrounding Phosphorylated Protein Sites

    Institute of Scientific and Technical Information of China (English)

    Shi-Cai Fan; Xue-Gong Zhang

    2005-01-01

    Protein phosphorylation plays an important role in various cellular processes. Due to its high complexity, the mechanism needs to be further studied. In the last few years, many methods have been contributed to this field, but almost all of them investigated the mechanism based on protein sequences around protein sites. In this study, we implement an exploration by characterizing the microenvironment surrounding phosphorylated protein sites with a modified shell model, and obtain some significant properties by the rank-sum test, such as the lack of some classes of residues, atoms, and secondary structures. Furthermore, we find that the depletion of some properties affects protein phosphorylation remarkably. Our results suggest that it is a meaningful direction to explore the mechanism of protein phosphorylation from microenvironment and we expect further findings along with the increasing size of phosphorylation and protein structure data.

  11. The rise and fall of immediate and delayed memory for verbal and visuospatial information from late childhood to late adulthood.

    Science.gov (United States)

    Murre, Jaap M J; Janssen, Steve M J; Rouw, Romke; Meeter, Martijn

    2013-01-01

    Over 100,000 verbal and visuospatial immediate and delayed memory tests were presented via the Internet to over 28,000 participants in the age range of 11 to 80. Structural equation modeling pointed to the verbal versus visuospatial dimension as an important factor in individual differences, but not the immediate versus delayed dimension. We found a linear decrease of 1% to 3% per year in overall memory performance past the age of 25. For visuospatial tests, this decrease started at age 18 and was twice as fast as the decrease of verbal memory. There were strong effects of education, with the highest educated group sometimes scoring one full standard deviation above the lowest educated group. Gender effects were small but as expected: women outperformed men on the verbal memory tasks; men outperformed women on the visuospatial tasks. We also found evidence of increasing proneness to false memory with age. Memory for recent news events did not show a decrease with age.

  12. The effects of repeat testing, malingering, and traumatic brain injury on visuospatial memory span

    Directory of Open Access Journals (Sweden)

    David L Woods

    2016-01-01

    Full Text Available Spatial span tests such as the Corsi Block Test (CBT and the spatial span test of the Wechsler Memory Scale are widely used to assess deficits in spatial working memory. We conducted three experiments to evaluate the test-retest reliability and clinical sensitivity of a new computerized spatial span test (C-SST that incorporates psychophysical methods to improve the precision of spatial span measurement. In Experiment 1, we analyzed C-SST test-retest reliability in 49 participants who underwent three test sessions at weekly intervals. Intraclass correlation coefficients (ICC were higher for a psychophysically derived mean span (MnS metric (0.83 than for the maximal span and total correct metrics used in traditional spatial-span tests. Response times (ReTs also showed high ICCs (0.93 that correlated negatively with MnS scores and correlated positively with response-time latencies from other tests of processing speed. Learning effects were insignificant. Experiment 2 examined the performance of Experiment 1 participants when instructed to feign symptoms of traumatic brain injury: 57% showed abnormal MnS z-scores. A MnS z-score cutoff of 3.0 correctly classified 36% of simulated malingerers and 91% of the subgroup of 11 control participants with abnormal spans. Malingerers also made more substitution errors than control participants with abnormal spans (sensitivity = 43%, specificity = 91%. In addition, malingerers showed no evidence of ReT slowing, in contrast to significant abnormalities seen on other malingered tests of processing speed. As a result, differences between ReT z-scores and z-scores on other processing speed tests showed very high sensitivity and specificity in distinguishing malingering and control participants with either normal or abnormal spans. Experiment 3 examined C-SST performance in a group of patients with predominantly mild traumatic brain injury (TBI: neither MnS nor ReT z-scores showed significant group

  13. "Tilt" in color space: Hue changes induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2015-01-01

    The perceived color of a chromatic stimulus is influenced by the chromaticity of its surround. To investigate these influences along the dimension of hue, we measured hue changes induced in stimuli of different hues by isoluminant chromatic surrounds. Generally, induced hue changes were directed in color space away from the hue of the inducing surround and depended on the magnitude on the hue difference between stimulus and surround. With increasing difference in hue between stimulus and surround, induced hue changes increased up to a maximum and then decreased for larger differences. This qualitative pattern was similar for different inducers, but quantitatively, induction was weaker along some directions in cone-opponent color space than along other directions. The strongest induction effects were found along an oblique, blue-yellow axis that corresponds to the daylight axis. The overall pattern of the induction effect shows similarities to the well-known tilt effect, where shifts in perceived angle of oriented stimuli are induced by oriented surrounds. This suggests analogous neural representations and similar mechanisms of contextual processing for different visual features such as orientation and color.

  14. Performance on tasks of visuospatial memory and ability: A cross-sectional study in 330 adolescents aged 11 to 20.

    Science.gov (United States)

    Burggraaf, Rudolf; Frens, Maarten A; Hooge, Ignace T C; van der Geest, Jos N

    2017-01-11

    Cognitive functions mature at different points in time between birth and adulthood. Of these functions, visuospatial skills, such as spatial memory and part-to-whole organization, have often been tested in children and adults but have been less frequently evaluated during adolescence. We studied visuospatial memory and ability during this critical developmental period, as well as the correlation between these abilities, in a large group of 330 participants (aged 11 to 20 years, 55% male). To assess visuospatial memory, the participants were asked to memorize and reproduce sequences of random locations within a grid using a computer. Visuospatial ability was tested using a variation of the Design Organization Test (DOT). In this paper-and-pencil test, the participants had one minute to reproduce as many visual patterns as possible using a numerical code. On the memory task, compared with younger participants, older participants correctly reproduced more locations overall and longer sequences of locations, made fewer mistakes and needed less time to reproduce the sequences. In the visuospatial ability task, the number of correctly reproduced patterns increased with age. We show that both visuospatial memory and ability improve significantly throughout adolescence and that performance on both tasks is significantly correlated.

  15. Semantic, executive, and visuospatial abilities in mathematical reasoning of referred college students.

    Science.gov (United States)

    Cirino, Paul T; Morris, Mary K; Morris, Robin D

    2007-03-01

    Semantic retrieval (SR) and executive-procedural (EP), but not visuospatial (VS) skills, have been found to be uniquely predictive of mathematical calculation skills in a sample of clinically referred college students. This study set out to cross-validate these results in an independent sample of clinically referred college students (N = 337) as well as extend them by examination of the contributions of these cognitive domains to math reasoning skills. Results indicate that these cognitive domains were able to predict 30% of the variance in calculation skills and 50% of the variance in math reasoning; however, in both cases, only the domains of semantic retrieval and visuospatial skill contributed uniquely. Differences between studies, and the lack of unique contribution of the EP domain to either type of math skill, may be due to measurement and sampling differences, the degree of shared relations among domains, and the choice of measures that represent the EP domain. Implications and future directions are explored.

  16. Deficits in memory and visuospatial learning correlate with regional hippocampal atrophy in MS.

    Science.gov (United States)

    Longoni, Giulia; Rocca, Maria A; Pagani, Elisabetta; Riccitelli, Gianna C; Colombo, Bruno; Rodegher, Mariaemma; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo

    2015-01-01

    The hippocampus has a critical role in episodic memory and visuospatial learning and consolidation. We assessed the patterns of whole and regional hippocampal atrophy in a large group of multiple sclerosis (MS) patients, and their correlations with neuropsychological impairment. From 103 MS patients and 28 healthy controls (HC), brain dual-echo and high-resolution 3D T1-weighted images were acquired using a 3.0-Tesla scanner. All patients underwent a neuropsychological assessment of hippocampal-related cognitive functions, including Paired Associate Word Learning, Short Story, delayed recall of Rey-Osterrieth Complex Figure and Paced Auditory Serial Attention tests. The hippocampi were manually segmented and volumes derived. Regional atrophy distribution was assessed using a radial mapping analysis. Correlations between hippocampal atrophy and clinical, neuropsychological and MRI metrics were also evaluated. Hippocampal volume was reduced in MS patients vs HC (p memory and visuospatial abilities.

  17. Contour detection by surround suppression of texture

    NARCIS (Netherlands)

    Petkov, Nicolai; Tavares, JMRS; Jorge, RMN

    2007-01-01

    Based on a keynote lecture at Complmage 2006, Coimbra, Oct. 20-21, 2006, an overview is given of our activities in modelling and using surround inhibition for contour detection. The effect of suppression of a line or edge stimulus by similar surrounding stimuli is known from visual perception studie

  18. rTMS of the unaffected hemisphere transiently reduces contralesional visuospatial hemineglect.

    Science.gov (United States)

    Oliveri, M; Bisiach, E; Brighina, F; Piazza, A; La Bua, V; Buffa, D; Fierro, B

    2001-10-09

    To verify the role of interhemispheric influences on manifestations of neglect, the authors investigated the effects of a transient repetitive transcranial magnetic stimulation (rTMS)-induced disruption of the unaffected hemisphere on contralesional visuospatial neglect in two left- and five right-brain-damaged patients. Parietal rTMS of the unaffected hemisphere during the execution of a computerized task of bisected line's length judgment transiently decreased the magnitude of neglect as expressed in the number of errors.

  19. The decline of verbal and visuospatial working memory across the adult life span

    OpenAIRE

    Cansino, Selene; Hernández-Ramos, Evelia; Estrada-Manilla, Cinthya; Torres-Trejo, Frine; Martínez-Galindo, Joyce Graciela; Ayala-Hernández, Mariana; Gómez-Fernández, Tania; Osorio, David; Cedillo-Tinoco, Melisa; Garcés-Flores, Lissete; Beltrán-Palacios, Karla; García-Lázaro, Haydée Guadalupe; García-Gutiérrez, Fabiola; Cadena-Arenas, Yadira; Fernández-Apan, Luisa

    2013-01-01

    It has been well established that working memory abilities decrease with advancing age; however, the specific time point in the adult life span at which this deficit begins and the rate at which it advances are still controversial. There is no agreement on whether working memory declines equally for visuospatial and verbal information, and the literature disagrees on how task difficulty may influence this decay. We addressed these questions in a lifespan sample of 1,500 participants between 2...

  20. Sex differences in visuospatial and navigational working memory: the role of mood induced by background music.

    Science.gov (United States)

    Palmiero, Massimiliano; Nori, Raffaella; Rogolino, Carmelo; D'amico, Simonetta; Piccardi, Laura

    2016-08-01

    Sex differences in visuospatial abilities are long debated. Men generally outperform women, especially in wayfinding or learning a route or a sequence of places. These differences might depend on women's disadvantage in underlying spatial competences, such as mental rotation, and on the strategies used, as well as on emotions and on self-belief about navigational skills, not related to actual skill-levels. In the present study, sex differences in visuospatial and navigational working memory in emotional contexts were investigated. Participants' mood was manipulated by background music (positive, negative or neutral) while performing on the Corsi Block-tapping Task (CBT) and Walking Corsi (WalCT) test. In order to assess the effectiveness of mood manipulation, participants filled in the Positive and Negative Affect Schedule before and after carrying out the visuospatial tasks. Firstly, results showed that after mood induction, only the positive affect changed, whereas the negative affect remained unconfounded by mood and by sex. This finding is in line with the main effect of 'group' on all tests used: the positive music group scored significantly higher than other groups. Secondly, although men outperformed women in the CBT forward condition and in the WalCT forward and backward conditions, they scored higher than women only in the WalCT with the negative background music. This means that mood cannot fully explain sex differences in visuospatial and navigational working memory. Our results suggest that sex differences in the CBT and WalCT can be better explained by differences in spatial competences rather than by emotional contexts.

  1. Sex-Related Differences in the Effects of Sleep Habits on Verbal and Visuospatial Working Memory

    OpenAIRE

    Seishu Nakagawa; Hikaru Takeuchi; Yasuyuki Taki; Rui Nouchi; Atsushi Sekiguchi; Yuka Kotozaki; Carlos Makoto Miyauchi; Kunio Iizuka; Ryoichi Yokoyama; Takamitsu Shinada; Yuki Yamamoto; Sugiko Hanawa; Tsuyoshi Araki; Keiko Kunitoki; Yuko Sassa

    2016-01-01

    Sleep facilitates memory consolidation. Consequently, poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF). Declarative working memory can be subdivided into verbal working memory (VWM) and visuospatial working memory (VSWM). We hypothesized that sleep habits would have different effects on VWM and...

  2. Subarachnoid hemorrhage and visuospatial and visuoperceptive impairment: disruption of the mirror neuron system.

    Science.gov (United States)

    Plata-Bello, Julio; Modroño, Cristián; Acosta-López, Silvia; Pérez-Martín, Yaiza; Marcano, Francisco; García-Marín, Víctor; González-Mora, José Luis

    2016-10-12

    Nearly 20 % of patients who suffer a subarachnoid hemorrhage (SAH) still display cognitive impairment even a year after follow-up. Visuospatial and visuoperceptive domains may be impaired in this cognitive impairment and may not have been fully studied in these patients. Furthermore, these cognitively impaired domains have been associated with activity in the so-called mirror neuron system (MNS). The aim of the study is to analyze the pattern of brain activity with an MNS task-based functional magnetic resonance imaging (fMRI) study in SAH patients. A complete neuropsychological assessment and fMRI study (with observation and execution conditions) were performed in patients with a history of SAH registered in the database of the Hospital Universitario de Canarias and a healthy control group. The patients had to meet all the following inclusion criteria for the study (less than 50 years old; SAH with a Fisher score 1-3; no vasospasm or ischemia; minimum follow-up of one year). Twelve SAH patients were studied. Three of which displayed visuospatial/visuoperceptive impairment. fMRI study showed the presence of higher activity in MNS regions in these patients than in patients with normal visuospatial/visuoperceptive functions. Furthermore, there was a negative correlation between the test scores and brain activity in premotor regions of the studied patients. SAH patients with visuospatial/visuoperceptive impairment have greater activity in the MNS regions. This finding may be associated with a subcortical dysfunction, leading to a disruption of neural activity and less efficient behavior of this brain network.

  3. Relationship between memory performance, visuospatial function and functional lateralization in adults

    OpenAIRE

    Bilić, Katja

    2011-01-01

    Age-related decline in memory and other cognitive functions, such as visuospatial functions is widely studied and well documented. In recent years, some studies have also found relationships between memory performance and functional body lateralization, with individuals who are inconsistently lateralized (e.g. have inconsistent handedness) scoring higher on episodic memory tests. The objectives of this study were to investigate relationships and possible differences between episodic and seman...

  4. Cross-modal activation of auditory regions during visuo-spatial working memory in early deafness.

    Science.gov (United States)

    Ding, Hao; Qin, Wen; Liang, Meng; Ming, Dong; Wan, Baikun; Li, Qiang; Yu, Chunshui

    2015-09-01

    Early deafness can reshape deprived auditory regions to enable the processing of signals from the remaining intact sensory modalities. Cross-modal activation has been observed in auditory regions during non-auditory tasks in early deaf subjects. In hearing subjects, visual working memory can evoke activation of the visual cortex, which further contributes to behavioural performance. In early deaf subjects, however, whether and how auditory regions participate in visual working memory remains unclear. We hypothesized that auditory regions may be involved in visual working memory processing and activation of auditory regions may contribute to the superior behavioural performance of early deaf subjects. In this study, 41 early deaf subjects (22 females and 19 males, age range: 20-26 years, age of onset of deafness deaf subjects exhibited faster reaction times on the spatial working memory task than did the hearing controls. Compared with hearing controls, deaf subjects exhibited increased activation in the superior temporal gyrus bilaterally during the recognition stage. This increased activation amplitude predicted faster and more accurate working memory performance in deaf subjects. Deaf subjects also had increased activation in the superior temporal gyrus bilaterally during the maintenance stage and in the right superior temporal gyrus during the encoding stage. These increased activation amplitude also predicted faster reaction times on the spatial working memory task in deaf subjects. These findings suggest that cross-modal plasticity occurs in auditory association areas in early deaf subjects. These areas are involved in visuo-spatial working memory. Furthermore, amplitudes of cross-modal activation during the maintenance stage were positively correlated with the age of onset of hearing aid use and were negatively correlated with the percentage of lifetime hearing aid use in deaf subjects. These findings suggest that earlier and longer hearing aid use may

  5. Visuospatial declarative learning despite profound verbal declarative amnesia in Korsakoff's syndrome.

    Science.gov (United States)

    Oudman, Erik; Postma, Albert; Nijboer, Tanja C W; Wijnia, Jan W; Van der Stigchel, Stefan

    2017-03-20

    Korsakoff's syndrome (KS) is a neuropsychiatric disorder characterised by severe amnesia. Although the presence of impairments in memory has long been acknowledged, there is a lack of knowledge about the precise characteristics of declarative memory capacities in order to implement memory rehabilitation. In this study, we investigated the extent to which patients diagnosed with KS have preserved declarative memory capacities in working memory, long-term memory encoding or long-term memory recall operations, and whether these capacities are most preserved for verbal or visuospatial content. The results of this study demonstrate that patients with KS have compromised declarative memory functioning on all memory indices. Performance was lowest for the encoding operation compared to the working memory and delayed recall operation. With respect to the content, visuospatial memory was relatively better preserved than verbal memory. All memory operations functioned suboptimally, although the most pronounced disturbance was found in verbal memory encoding. Based on the preserved declarative memory capacities in patients, visuospatial memory can form a more promising target for compensatory memory rehabilitation than verbal memory. It is therefore relevant to increase the number of spatial cues in memory rehabilitation for KS patients.

  6. Central coherence, organizational strategy, and visuospatial memory in children and adolescents with anorexia nervosa.

    Science.gov (United States)

    Rose, Mark; Frampton, Ian J; Lask, Bryan

    2014-01-01

    The vast majority of studies in anorexia nervosa that have investigated the domains of central coherence, organizational strategy, and visuospatial memory have focused on adult samples. In addition, studies investigating visuospatial memory have focused on free recall. No study to date has reported the association between recognition memory and central coherence or organizational strategy in younger people with this disorder, yet the capacity to recognize previously seen visual stimuli may contribute to overall visuospatial ability. Therefore, we investigate these domains in children and adolescents with anorexia nervosa compared to age- and gender-matched healthy controls. There were no significant group differences in immediate, delayed, or recognition memory, central coherence, or organization strategy. When compared with controls, patients with anorexia nervosa scored significantly higher on accuracy and took significantly longer when copying the Rey Complex Figure Task. Caution must be taken when interpreting these findings due to lower-than-expected scores in memory performance in the control group and because of a potential lack of sensitivity in the measures used when assessing this younger population. For neuropsychological functions where no normative data exist, we need a deeper, more thorough knowledge of the developmental trajectory and its assessment in young people in the general population before drawing conclusions in anorexia nervosa.

  7. The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity.

    Science.gov (United States)

    Beauchene, Christine; Abaid, Nicole; Moran, Rosalyn; Diana, Rachel A; Leonessa, Alexander

    2016-01-01

    Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

  8. Pattern of visuospatial lateralization in two corvid species, black-billed magpies and Clark's nutcrackers.

    Science.gov (United States)

    Clary, Dawson; Cheys, Amanda; Kelly, Debbie M

    2014-09-01

    Cerebral lateralization is widespread amongst vertebrate species suggesting advantages are gained by having one of the brain's hemispheres exert dominant control over certain cognitive functions. A recently devised task for assessing lateralization of visuospatial attention by birds (Diekamp et al., 2005) has allowed researchers to suggest the corpus callosum may not be necessary for the emergence of such asymmetries. More recently, this task has been adopted to examine the embryonic development of lateralization in birds, research which may provide important insights as to the underlying genetic mechanisms (Chiandetti, 2011; Chiandetti et al., 2013) of vertebrate cerebral lateralization. However, to date only chicks and pigeons have been used in this paradigm. Thus, it is unclear whether other avian species will also show lateralization of visuospatial attention during this task. Here, we examined the pattern of visuospatial lateralization in two corvid species: social black-billed magpies (Pica hudsonia) and non-social Clark's nutcrackers (Nucifraga columbiana). We find that neither the magpies nor the nutcrackers show evidence for population level lateralization or predictable individual level lateralization, as only a subset of individuals of each species showed a significant individual bias, which were rarely stable over repeated testing.

  9. Children's use of decomposition strategies mediates the visuospatial memory and arithmetic accuracy relation.

    Science.gov (United States)

    Foley, Alana E; Vasilyeva, Marina; Laski, Elida V

    2016-12-14

    This study examined the mediating role of children's use of decomposition strategies in the relation between visuospatial memory (VSM) and arithmetic accuracy. Children (N = 78; Age M = 9.36) completed assessments of VSM, arithmetic strategies, and arithmetic accuracy. Consistent with previous findings, VSM predicted arithmetic accuracy in children. Extending previous findings, the current study showed that the relation between VSM and arithmetic performance was mediated by the frequency of children's use of decomposition strategies. Identifying the role of arithmetic strategies in this relation has implications for increasing the math performance of children with lower VSM. Statement of contribution What is already known on this subject? The link between children's visuospatial working memory and arithmetic accuracy is well documented. Frequency of decomposition strategy use is positively related to children's arithmetic accuracy. Children's spatial skill positively predicts the frequency with which they use decomposition. What does this study add? Short-term visuospatial memory (VSM) positively relates to the frequency of children's decomposition use. Decomposition use mediates the relation between short-term VSM and arithmetic accuracy. Children with limited short-term VSM may struggle to use decomposition, decreasing accuracy.

  10. Organization of visuo-spatial serial memory: interaction of temporal order with spatial and temporal grouping.

    Science.gov (United States)

    Parmentier, Fabrice B R; Andrés, Pilar; Elford, Greg; Jones, Dylan M

    2006-05-01

    This study investigates whether memory for sequences of spatial locations can be represented hierarchically, that is, as successive groups containing the order of constituent locations. Two grouping manipulations are used: Temporal grouping, based on the verbal serial memory literature, and spatial grouping, based on recent empirical work on visuo-spatial serial memory. In Experiment 1, we examine the relationship between spatial grouping and temporal order and showed that recall performance increases when both temporal and spatial organization correlate, but decreases when they clash. Experiments 2 and 3 show that the latter result is confounded by differences in path length (length of spatial path defined by the locations) between conditions, and that no effect of the spatial organization is observed when path length is controlled for. In Experiment 4, an alternative method to spatial grouping, temporal grouping, is used to induce hierarchical organization. A recall advantage is found in the temporal grouping condition. The results suggest that hierarchical representations can be imposed on order information for visuo-spatial sequences, either when participants have pre-existing knowledge about the form of the path formed by the sequence or when temporal boundaries delimit chunks; that increased path length is the cause of the performance decrement observed when dots from separate spatial groups are presented successively; and that path length and more generally sequence characteristics should be taken into account in designing future research on visuo-spatial serial memory.

  11. Preliminary design of surrounding heliostat fields

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Francisco J. [Zaragoza University, Dpto. de Ingenieria Mecanica, CPS-B, Maria de Luna 3, 50018 Zaragoza (Spain)

    2009-05-15

    Recently, the author has shown elsewhere a simplified model that allows quick evaluations of the annual overall energy collected by a surrounding heliostat field. This model is the combination of an analytical flux density function produced by a heliostat, developed by the own author, and an optimized mirror density distribution developed by University of Houston for the Solar One Project. As main conclusion of this previous work, it was recognized that such pseudo-continuous simplified model should not substitute much more accurate discrete evaluations, which manage thousands of individual heliostat coordinates. Here in this work, the difficulty of generating a preliminary discrete layout of a large number of heliostats is addressed. The main novelty is the direct definition of thousands of heliostat coordinates through basically two parameters i.e. a simplified blocking factor and an additional security distance. Such procedure, which was formerly theoretically suggested by the author, is put into practice here, showing examples and commenting their problems and advantages. Getting a previous set of thousands of heliostat coordinates would be a major first step in the complex process of designing solar power tower (SPT). (author)

  12. Ecological mechanisms linking protected areas to surrounding lands.

    Science.gov (United States)

    Hansen, Andrew J; DeFries, Ruth

    2007-06-01

    Land use is expanding and intensifying in the unprotected lands surrounding many of the world's protected areas. The influence of this land use change on ecological processes is poorly understood. The goal of this paper is to draw on ecological theory to provide a synthetic framework for understanding how land use change around protected areas may alter ecological processes and biodiversity within protected areas and to provide a basis for identifying scientifically based management alternatives. We first present a conceptual model of protected areas embedded within larger ecosystems that often include surrounding human land use. Drawing on case studies in this Invited Feature, we then explore a comprehensive set of ecological mechanisms by which land use on surrounding lands may influence ecological processes and biodiversity within reserves. These mechanisms involve changes in ecosystem size, with implications for minimum dynamic area, species-area effect, and trophic structure; altered flows of materials and disturbances into and out of reserves; effects on crucial habitats for seasonal and migration movements and population source/sink dynamics; and exposure to humans through hunting, poaching, exotics species, and disease. These ecological mechanisms provide a basis for assessing the vulnerability of protected areas to land use. They also suggest criteria for designing regional management to sustain protected areas in the context of surrounding human land use. These design criteria include maximizing the area of functional habitats, identifying and maintaining ecological process zones, maintaining key migration and source habitats, and managing human proximity and edge effects.

  13. Agroforestry practice in villages surrounding Nyamure former ...

    African Journals Online (AJOL)

    cntaganda

    Key words: Agroforestry, fuel wood, tree products, woodlot, forest plantation. INTRODUCTION ... The study area included three administrative cells in the surroundings of Nyamure ..... Table 6: Distance and time spent on firewood collection.

  14. Explaining preferences for home surroundings and locations

    Directory of Open Access Journals (Sweden)

    Hans Skifter Andersen

    2011-01-01

    Full Text Available This article is based on a survey carried out in Denmark that asked a random sample of the population about their preferences for home surroundings and locations. It shows that the characteristics of social surroundings are very important and can be divided into three independent dimensions: avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific preferences for surroundings.

  15. Surround-Masking Affects Visual Estimation Ability

    Science.gov (United States)

    Jastrzebski, Nicola R.; Hugrass, Laila E.; Crewther, Sheila G.; Crewther, David P.

    2017-01-01

    Visual estimation of numerosity involves the discrimination of magnitude between two distributions or perceptual sets that vary in number of elements. How performance on such estimation depends on peripheral sensory stimulation is unclear, even in typically developing adults. Here, we varied the central and surround contrast of stimuli that comprised a visual estimation task in order to determine whether mechanisms involved with the removal of unessential visual input functionally contributes toward number acuity. The visual estimation judgments of typically developed adults were significantly impaired for high but not low contrast surround stimulus conditions. The center and surround contrasts of the stimuli also differentially affected the accuracy of numerosity estimation depending on whether fewer or more dots were presented. Remarkably, observers demonstrated the highest mean percentage accuracy across stimulus conditions in the discrimination of more elements when the surround contrast was low and the background luminance of the central region containing the elements was dark (black center). Conversely, accuracy was severely impaired during the discrimination of fewer elements when the surround contrast was high and the background luminance of the central region was mid level (gray center). These findings suggest that estimation ability is functionally related to the quality of low-order filtration of unessential visual information. These surround masking results may help understanding of the poor visual estimation ability commonly observed in developmental dyscalculia.

  16. Dystypia: isolated typing impairment without aphasia, apraxia or visuospatial impairment.

    Science.gov (United States)

    Otsuki, Mika; Soma, Yoshiaki; Arihiro, Shoji; Watanabe, Yoshimasa; Moriwaki, Hiroshi; Naritomi, Hiroaki

    2002-01-01

    We report a 60-year-old right-handed Japanese man who showed an isolated persistent typing impairment without aphasia, agraphia, apraxia or any other neuropsychological deficit. We coined the term 'dystypia' for this peculiar neuropsychological manifestation. The symptom was caused by an infarction in the left frontal lobe involving the foot of the second frontal convolution and the frontal operculum. The patient's typing impairment was not attributable to a disturbance of the linguistic process, since he had no aphasia or agraphia. The impairment was not attributable to the impairment of the motor execution process either, since he had no apraxia. Thus, his typing impairment was deduced to be based on a disturbance of the intermediate process where the linguistic phonological information is converted into the corresponding performance. We hypothesized that there is a specific process for typing which branches from the motor programming process presented in neurolinguistic models. The foot of the left second frontal convolution and the operculum may play an important role in the manifestation of 'dystypia'.

  17. Migraine increases centre-surround suppression for drifting visual stimuli.

    Directory of Open Access Journals (Sweden)

    Josephine Battista

    Full Text Available BACKGROUND: The pathophysiology of migraine is incompletely understood, but evidence points to hyper-responsivity of cortical neurons being a key feature. The basis of hyper-responsiveness is not clear, with an excitability imbalance potentially arising from either reduced inhibition or increased excitation. In this study, we measure centre-surround contrast suppression in people with migraine as a perceptual analogue of the interplay between inhibition and excitation in cortical areas responsible for vision. We predicted that reduced inhibitory function in migraine would reduce perceptual surround suppression. Recent models of neuronal surround suppression incorporate excitatory feedback that drives surround inhibition. Consequently, an increase in excitation predicts an increase in perceptual surround suppression. METHODS AND FINDINGS: Twenty-six people with migraine and twenty approximately age- and gender-matched non-headache controls participated. The perceived contrast of a central sinusoidal grating patch (4 c/deg stationary grating, or 2 c/deg drifting at 2 deg/sec, 40% contrast was measured in the presence and absence of a 95% contrast annular grating (same orientation, spatial frequency, and drift rate. For the static grating, similar surround suppression strength was present in control and migraine groups with the presence of the surround resulting in the central patch appearing to be 72% and 65% of its true contrast for control and migraine groups respectively (t(44 = 0.81, p = 0.42. For the drifting stimulus, the migraine group showed significantly increased surround suppression (t(44 = 2.86, p<0.01, with perceived contrast being on average 53% of actual contrast for the migraine group and 68% for non-headache controls. CONCLUSIONS: In between migraines, when asymptomatic, visual surround suppression for drifting stimuli is greater in individuals with migraine than in controls. The data provides evidence for a

  18. Visuospatial working memory for locations, colours, and binding in typically developing children and in children with dyslexia and non-verbal learning disability.

    Science.gov (United States)

    Garcia, Ricardo Basso; Mammarella, Irene C; Tripodi, Doriana; Cornoldi, Cesare

    2014-03-01

    This study examined forward and backward recall of locations and colours and the binding of locations and colours, comparing typically developing children - aged between 8 and 10 years - with two different groups of children of the same age with learning disabilities (dyslexia in one group, non-verbal learning disability [NLD] in the other). Results showed that groups with learning disabilities had different visuospatial working memory problems and that children with NLD had particular difficulties in the backward recall of locations. The differences between the groups disappeared, however, when locations and colours were bound together. It was concluded that specific processes may be involved in children in the binding and backward recall of different types of information, as they are not simply the resultant of combining the single processes needed to recall single features.

  19. Subitizing Reflects Visuo-Spatial Object Individuation Capacity

    Science.gov (United States)

    Piazza, Manuela; Fumarola, Antonia; Chinello, Alessandro; Melcher, David

    2011-01-01

    Subitizing is the immediate apprehension of the exact number of items in small sets. Despite more than a 100 years of research around this phenomenon, its nature and origin are still unknown. One view posits that it reflects a number estimation process common for small and large sets, which precision decreases as the number of items increases,…

  20. Handwriting Fluency and Visuospatial Generativity at Primary School

    Science.gov (United States)

    Stievano, Paolo; Michetti, Silvia; McClintock, Shawn M.; Levi, Gabriel; Scalisi, Teresa Gloria

    2016-01-01

    Handwriting is a complex activity that involves continuous interaction between lowerlevel perceptual-motor and higher-level cognitive processes. All handwriting models describe involvement of executive functions (EF) in handwriting development. Particular EF domains associated with handwriting include maintenance of information in working memory,…

  1. Shaping Relations: Exploiting Relational Features for Visuospatial Priming

    Science.gov (United States)

    Livins, Katherine A.; Doumas, Leonidas A. A.; Spivey, Michael J.

    2016-01-01

    Although relational reasoning has been described as a process at the heart of human cognition, the exact character of relational representations remains an open debate. Symbolic-connectionist models of relational cognition suggest that relations are structured representations, but that they are ultimately grounded in feature sets; thus, they…

  2. Benefit of Multiple Sessions of Perilesional Repetitive Transcranial Magnetic Stimulation for an Effective Rehabilitation of Visuo-Spatial Function

    Science.gov (United States)

    Afifi, Linda; Rushmore, R. Jarrett; Valero-Cabré, Antoni

    2012-01-01

    Non-invasive neurostimulation techniques have been used alone or in conjunction with rehabilitation therapy to treat the neurological sequelae of brain damage with rather variable therapeutic outcomes. One potential factor limiting a consistent success for such techniques may be the few sessions carried out in patients, despite reports that their accrual may play a key role in alleviating neurological deficits long-term. In this study, we tested the effects of seventy consecutive sessions of perilesional high frequency (10 Hz) repetitive transcranial magnetic stimulation (rTMS) in the treatment of chronic neglect deficits in a well-established feline model of visuo-spatial neglect. Under identical rTMS parameters and visuo-spatial testing regimes, half of the subjects improved in visuo-spatial orienting performance. The other half experienced either none or extremely moderate ameliorations in the neglected hemispace and displayed transient patterns of maladaptive visuo-spatial behavior. Detailed analyses suggest that lesion location and extent did not account for the behavioral differences observed between these two groups of animals. We conclude that multi-session perilesional rTMS regimes have the potential to induce functional ameliorations following focal chronic brain injury, and that behavioral performance prior to the onset of the rTMS treatment is the factor that best predicts positive outcomes for non-invasive neurostimulation treatments in visuo-spatial neglect. PMID:23167832

  3. Benefit of multiple sessions of perilesional repetitive transcranial magnetic stimulation for an effective rehabilitation of visuospatial function.

    Science.gov (United States)

    Afifi, Linda; Jarrett Rushmore, R; Valero-Cabré, Antoni

    2013-02-01

    Noninvasive neurostimulation techniques have been used alone or in conjunction with rehabilitation therapy to treat the neurological sequelae of brain damage with rather variable therapeutic outcomes. One potential factor limiting a consistent success for such techniques may be the limited number of sessions carried out in patients, despite reports that their accrual may play a key role in alleviating neurological deficits long-term. In this study, we tested the effects of seventy consecutive sessions of perilesional high-frequency (10 Hz) repetitive transcranial magnetic stimulation (rTMS) in the treatment of chronic neglect deficits in a well-established feline model of visuospatial neglect. Under identical rTMS parameters and visuospatial testing regimes, half of the subjects improved in visuospatial orienting performance. The other half experienced either none or extremely moderate ameliorations in the neglected hemispace and displayed transient patterns of maladaptive visuospatial behavior. Detailed analyses suggest that lesion location and extent did not account for the behavioral differences observed between these two groups of animals. We conclude that multi-session perilesional rTMS regimes have the potential to induce functional ameliorations following focal chronic brain injury, and that behavioral performance prior to the onset of the rTMS treatment is the factor that best predicts positive outcomes for noninvasive neurostimulation treatments in visuospatial neglect.

  4. Development of the four-item Letter and Shape Drawing test (LSD-4): A brief bedside test of visuospatial function.

    Science.gov (United States)

    Williams, Olugbenga Alaba; O'Connell, Henry; Leonard, Maeve; Awan, Fahad; White, Debbie; McKenna, Frank; Hannigan, Ailish; Cullen, Walter; Exton, Chris; Enudi, Walter; Dunne, Colum; Adamis, Dimitrios; Meagher, David

    2017-01-01

    Conventional bedside tests of visuospatial function such as the Clock Drawing (CDT) and Intersecting Pentagons (IPT) lack consistency in delivery and interpretation. We compared performance on a novel test of visuospatial ability - the LSD - with the IPT, CDT and MMSE in 180 acute elderly medical inpatients [mean age 79.7±7.1 (range 62-96); 91 females (50.6%)]. 124 (69%) scored ≤23 on the MMSE; 60 with mild (score 18-23) and 64 with severe (score ≤17) impairment. 78 (43%) scored ≥6 on the CDT, while for the IPT, 87 (47%) scored ≥4. The CDT and IPT agreed on the classification of 138 patients (77%) with modest-strong agreement with the MMSE categories. Correlation between the LSD and visuospatial tests was high. A four-item version of the LSD incorporating items 1,10,12,15 had high correlation with the LSD-15 and strong association with MMSE categories. The LSD-4 provides a brief and easily interpreted bedside test of visuospatial function that has high coverage of elderly patients with neurocognitive impairment, good agreement with conventional tests of visuospatial ability and favourable ability to identify significant cognitive impairment. [181 words].

  5. Negative visuospatial priming in isolation-reared rats: Evidence of resistance to the disruptive effects of amphetamine.

    Science.gov (United States)

    Amitai, Nurith; Powell, Susan; Weber, Martin; Swerdlow, Neal R; Young, Jared W

    2015-12-01

    Negative visuospatial priming (NP) represents a quantifiable measure of inhibitory information processing that is disrupted in several neurodevelopmental and psychiatric disorders, including schizophrenia. We developed a novel rodent NP task to investigate mechanisms underlying NP and its role in various disorders, and to test potential therapeutics. In the present studies, we further characterized this novel paradigm by investigating whether NP is disrupted in rats reared in isolation, a developmental manipulation that produces a range of abnormalities in behavior, neurochemistry, and brain structure that mirror aspects of schizophrenia pathology. We also further explored the role of monoaminergic signaling in NP and the effects of isolation rearing by challenging both socially reared and isolation-reared rats with D-amphetamine during the NP task. Although fewer isolation-reared animals learned the complex NP task, those that learned exhibited unaffected NP compared with socially reared rats. Consistent with previous reports, D-amphetamine impaired NP and increased motor impulsivity in socially reared rats. In contrast, D-amphetamine did not affect NP or motor impulsivity in isolation-reared rats. These data confirm a monoaminergic influence on NP behavior and indicate that rats reared in isolation have altered dopaminergic sensitivity.

  6. Identifying Oneself with the Face of Someone Else Impairs the Egocentered Visuo-spatial Mechanisms: A New Double Mirror Paradigm to Study Self–other Distinction and Interaction

    Science.gov (United States)

    Thirioux, Bérangère; Wehrmann, Moritz; Langbour, Nicolas; Jaafari, Nematollah; Berthoz, Alain

    2016-01-01

    Looking at our face in a mirror is one of the strongest phenomenological experiences of the Self in which we need to identify the face as reflected in the mirror as belonging to us. Recent behavioral and neuroimaging studies reported that self-face identification not only relies upon visual-mnemonic representation of one’s own face but also upon continuous updating and integration of visuo-tactile signals. Therefore, bodily self-consciousness plays a major role in self-face identification, with respect to interplay between unisensory and multisensory processing. However, if previous studies demonstrated that the integration of multisensory body-related signals contributes to the visual processing of one’s own face, there is so far no data regarding how self-face identification, inversely, contributes to bodily self-consciousness. In the present study, we tested whether self–other face identification impacts either the egocentered or heterocentered visuo-spatial mechanisms that are core processes of bodily self-consciousness and sustain self–other distinction. For that, we developed a new paradigm, named “Double Mirror.” This paradigm, consisting of a semi-transparent double mirror and computer-controlled Light Emitting Diodes, elicits self–other face merging illusory effect in ecologically more valid conditions, i.e., when participants are physically facing each other and interacting. Self-face identification was manipulated by exposing pairs of participants to an Interpersonal Visual Stimulation in which the reflection of their faces merged in the mirror. Participants simultaneously performed visuo-spatial and mental own-body transformation tasks centered on their own face (egocentered) or the face of their partner (heterocentered) in the pre- and post-stimulation phase. We show that self–other face identification altered the egocentered visuo-spatial mechanisms. Heterocentered coding was preserved. Our data suggest that changes in self

  7. Identifying oneself with the face of someone else impairs the egocentered visuo-spatial mechanisms: A new Double Mirror paradigm to study self-other distinction and interaction.

    Directory of Open Access Journals (Sweden)

    Berangere THIRIOUX

    2016-08-01

    Full Text Available Looking at our face in a mirror is one of the strongest phenomenological experiences of the Self in which we need to identify the face as reflected in the mirror as belonging to us. Recent behavioural and neuroimaging studies reported that self-face identification not only relies upon visual-mnemonic representation of one’s own face but also upon continuous updating and integration of visuo-tactile signals. Therefore, bodily self-consciousness plays a major role in self-face identification, with respect to interplay between unisensory and multisensory processing. However, if previous studies demonstrated that the integration of multisensory body-related signals contributes to the visual processing of one’s own face, there is so far no data regarding how self-face identification, inversely, contributes to bodily self-consciousness. In the present study, we tested whether self-other face identification impacts either the egocentered or heterocentered visuo-spatial mechanisms that are core processes of bodily self-consciousness and sustain self-other distinction. For that, we developed a new paradigm, named Double Mirror. This paradigm, consisting of a semi-transparent double mirror and computer-controlled Light Emitting Diodes, elicits self-other face merging illusory effect in ecologically more valid conditions, i.e., when participants are physically facing each other and interacting. Self-face identification was manipulated by exposing pairs of participants to an Interpersonal Visual Stimulation in which the reflection of their faces merged in the mirror. Participants simultaneously performed visuo-spatial and mental own-body transformation tasks centered on their own face (egocentered or the face of their partner (heterocentered in the pre- and post-stimulation phase. We show that self-other face identification altered the egocentered visuo-spatial mechanisms. Heterocentered coding was preserved. Our data suggest that changes in self

  8. Motor functioning, exploration, visuospatial cognition and language development in preschool children with autism.

    Science.gov (United States)

    Hellendoorn, Annika; Wijnroks, Lex; van Daalen, Emma; Dietz, Claudine; Buitelaar, Jan K; Leseman, Paul

    2015-04-01

    In order to understand typical and atypical developmental trajectories it is important to assess how strengths or weaknesses in one domain may be affecting performance in other domains. This study examined longitudinal relations between early fine motor functioning, visuospatial cognition, exploration, and language development in preschool children with ASD and children with other developmental delays/disorders. The ASD group included 63 children at T1 (Mage = 27.10 months, SD = 8.71) and 46 children at T2 (Mage = 45.85 months, SD = 7.16). The DD group consisted of 269 children at T1 (Mage = 17.99 months, SD = 5.59), and 121 children at T2 (Mag e= 43.51 months, SD = 3.81). A subgroup nested within the total sample was randomly selected and studied in-depth on exploratory behavior. This group consisted of 50 children, 21 children with ASD (Mage = 27.57, SD = 7.09) and 29 children with DD (Mage = 24.03 months, SD = 6.42). Fine motor functioning predicted language in both groups. Fine motor functioning was related to visuospatial cognition in both groups and related to object exploration, spatial exploration, and social orientation during exploration only in the ASD group. Visuospatial cognition and all exploration measures were related to both receptive and expressive language in both groups. The findings are in line with the embodied cognition theory, which suggests that cognition emerges from and is grounded in the bodily interactions of an agent with the environment. This study emphasizes the need for researchers and clinicians to consider cognition as emergent from multiple interacting systems.

  9. Detection of auditory signals in quiet and noisy backgrounds while performing a visuo-spatial task

    Directory of Open Access Journals (Sweden)

    Vishakha W Rawool

    2016-01-01

    Full Text Available Context: The ability to detect important auditory signals while performing visual tasks may be further compounded by background chatter. Thus, it is important to know how task performance may interact with background chatter to hinder signal detection. Aim: To examine any interactive effects of speech spectrum noise and task performance on the ability to detect signals. Settings and Design: The setting was a sound-treated booth. A repeated measures design was used. Materials and Methods: Auditory thresholds of 20 normal adults were determined at 0.5, 1, 2 and 4 kHz in the following conditions presented in a random order: (1 quiet with attention; (2 quiet with a visuo-spatial task or puzzle (distraction; (3 noise with attention and (4 noise with task. Statistical Analysis: Multivariate analyses of variance (MANOVA with three repeated factors (quiet versus noise, visuo-spatial task versus no task, signal frequency. Results: MANOVA revealed significant main effects for noise and signal frequency and significant noise–frequency and task–frequency interactions. Distraction caused by performing the task worsened the thresholds for tones presented at the beginning of the experiment and had no effect on tones presented in the middle. At the end of the experiment, thresholds (4 kHz were better while performing the task than those obtained without performing the task. These effects were similar across the quiet and noise conditions. Conclusion: Detection of auditory signals is difficult at the beginning of a distracting visuo-spatial task but over time, task learning and auditory training effects can nullify the effect of distraction and may improve detection of high frequency sounds.

  10. Development of SNARC and distance effects and their relation to mathematical and visuospatial abilities.

    Science.gov (United States)

    Gibson, Laura C; Maurer, Daphne

    2016-10-01

    The current experiment measured symbolic SNARC (Spatial-Numeric Association of Response Codes) and distance effects in school-aged children and investigated the relation between these measures and visuospatial skills and mathematics ability. In the experiment, 6-, 7-, and 8-year-olds performed a magnitude-relevant SNARC task, in which they indicated whether a target number was less or greater than 5, as well as standardized tests of visuospatial skills (Developmental Test of Visual Perception-Second Edition, DTVP-2) and mathematics ability (Test of Early Mathematics Ability-Third Edition, TEMA-3). Consistent with previous research using numerical SNARC tasks with Western children, all age groups exhibited robust distance effects, and SNARC effects were observed only in 7- and 8-year-olds. Distance effects, but not SNARC effects, were moderately but significantly correlated with a subtest of the DTVP-2 measuring the ability to mentally manipulate objects in space but no other subtest. These data suggest that mental orientation abilities, but perhaps not visuospatial skills involved in visual perception and visuomotor coordination, are related to some aspects of mental number line development. Nevertheless, no relation was observed between SNARC or distance effects and mathematics ability. This result is consistent with previous developmental studies investigating the association between SNARC and math skill. However, these data are inconsistent with most experiments assessing the relationship between distance effect strength and math-a difference that can likely be attributed to the fact that a magnitude-relevant SNARC task was employed as opposed to a traditional SNARC parity task.

  11. Relation between sleep and visuospatial skills in students from a public school

    Directory of Open Access Journals (Sweden)

    Danilo de Freitas Araújo

    2013-03-01

    Full Text Available The relation between the sleep and the visuospatial skills was evaluated in 31 students from a public school. For the analysis of sleep, the parents of volunteers answered a sleep evaluation questionnaire and the sleep diary. The visuospatial performance was evaluated by Wechsler Intelligence Scale for Children (WISC-III, through the subtest Picture Completion, the Perceptual Organization Index and the Performance IQ Scale. In accordance with the results, 72% of the students presented regular sleep and good sleep length. The visuospatial performance was deficient in subtest Picture Completion for 56% of the students, and on the Performance IQ Scale for 60% of the students. Significant correlations were verified between early sleep onset (rho = -0.40, p Avaliou-se a relação entre o sono e a visuoespacialidade em 31 estudantes de uma escola pública. Para a análise do sono, foram preenchidos, pelos pais dos voluntários, uma ficha de avaliação do sono e o diário do sono. O desempenho visuoespacial foi avaliado pela Escala de Inteligência Wechsler para Crianças (WISC-III, utilizando o subteste Completar Figuras, o índice fatorial Organização Perceptual e a Escala QIde Execução. De acordo com os resultados, 72% dos estudantes apresentaram sono regular e boa duração. O desempenho visuoespacial foi deficiente no subteste Completar Figuras para 56% dos estudantes, e na Escala QI de Execução para 60% dos alunos. Foram verificadas correlações significativas entre início do sono cedo (rho = -0,40, p < 0,05 e sono regular (rho = -0,39, p < 0,05 com o desempenho visuoespacial. Conclui-se que dormir mais cedo e ter um sono regular podem contribuir para um melhor desempenho visuoespacial.

  12. The anatomy of visuospatial construction revealed by lesion-symptom mapping.

    Science.gov (United States)

    Biesbroek, J Matthijs; van Zandvoort, Martine J E; Kuijf, Hugo J; Weaver, Nick A; Kappelle, L Jaap; Vos, Pieter C; Velthuis, Birgitta K; Biessels, Geert Jan; Postma, Albert

    2014-09-01

    Visuospatial construction is a complex cognitive operation that is composed of a purely constructional component (visuoconstruction proper), and visuoperceptive, attentional, and decision-making components. The anatomical correlates of visuospatial construction and its cognitive subcomponents are poorly understood. The purpose of the present study was to determine the anatomical correlates of visuospatial construction by applying lesion-symptom mapping in a cohort of 111 patients with first-ever ischemic stroke. We employed the Rey-Osterrieth Complex Figure (ROCF) copy test and the Judgment of Line Orientation (JLO); both tests measure visuoperception, while only the ROCF has a constructional component. We first performed assumption-free voxel-based lesion-symptom mapping, which revealed large shared right hemispheric correlates for the ROCF and JLO in the frontal lobe, superior temporal lobe, and supramarginal gyrus. These shared anatomical correlates reflect the visuoperceptive component of the ROCF and JLO. Anatomical correlates were discordant in the right superior parietal lobule, and angular and middle occipital gyri: lesions in these regions were associated with poor performance on the ROCF, but not the JLO. Secondly, these findings were reproduced with a region of interest-based analysis that yielded a statistically significant correlation between infarct volume in the right inferior and superior parietal, angular and middle occipital cortices, and poor performance on the ROCF, but not the JLO. This discordance in anatomical correlates of the ROCF and JLO reflects the visuoconstructive component of the ROCF. These findings provide new insights in the anatomical correlates of the visuoperceptive and visuoconstructive components of the ROCF and provide evidence for a crucial role of the right inferior and superior parietal, angular and middle occipital gyri in visuoconstruction proper.

  13. The coding and updating of visuospatial memory for goal-directed reaching and pointing.

    Science.gov (United States)

    Thompson, Aidan A; Henriques, Denise Y P

    2011-04-22

    In this review we discuss evidence from psychophysical, electrophysiological, and neuroimaging studies that demonstrates the updating of remembered visual space in a reference frame that is centred on the eye. We then extend these findings by discussing recent work from our lab. Specifically, we address eye-centred updating of visuospatial memory for arm movements following different types of eye movements, the role of retinal versus extraretinal information in such spatial updating, and the use of allocentric versus egocentric information in coding multiple targets. We provide a conceptual model to explain the relationships among these findings.

  14. New visuospatial associations by training verbospatial mappings in the first language.

    Science.gov (United States)

    Notebaert, Wim; De Moor, Wendy; Gevers, Wim; Hartsuiker, Robert J

    2007-12-01

    We investigated whether verbospatial and visuospatial information share a common representation. Wedemonstrate that when the associations from spatial words to spatial responses are altered, so that the word LEFT becomes associated with a right response and the word RIGHT with a left response, the associations from the spatial locations left and right to the spatial responses also change. This effect was only observed for first-language spatial words (Dutch) and not for second-language spatial words (French), and it did not increase when these languages were combined. The findings argue for shared spatial representations f ordifferent types of spatialinput.

  15. Pure agraphia and Gerstmann's syndrome as a visuospatial-language dissociation: an experimental case study.

    Science.gov (United States)

    Levine, D N; Mani, R B; Calvanio, R

    1988-09-01

    A right-handed man suffered a left parieto-occipital cerebral infarction, causing agraphia with Gerstmann's syndrome but without major aphasia, alexia, or apraxia. Oral spelling was superior to written spelling. Experiments were performed involving (1) analysis of errors in writing, (2) tasks of visual imagery, and (3) identifying letters drawn without leaving a visual trace. The results suggest that the agraphia and Gerstmann's syndrome are due to a dissociation of language skills and visuospatial skills caused by a dominant parieto-occipital lesion.

  16. 随机介质理论下隧道围岩渐进破坏过程数值实验研究%Numerical Experiment Research on the Progressive Failure Process of the Surrounding Rock of the Tunnel under the Stochastic Medium Theory

    Institute of Scientific and Technical Information of China (English)

    商拥辉; 李航; 张波; 方前程

    2015-01-01

    The strength subtraction is introduced to safety evaluation of tunnel surrounding rock,combining with “the shallow tunnel rapid construction double small spacing tunnels,wear interchange structure under the shield tunnel and the surface of the structure containing joint,irregular fissure of mountain highway tunnel”engi-neering examples,using real damage of material analysis software RFPA -2D ,the finite element model of each strength reduction factor is set up.Viscoelastic artificial boundary is adopted to eliminate the influence of boundary conditions on the calculation precision in model,and the model achieves the mesoscopic structure unit of surround-ing rock of the mean and the defects of random distribution by means of random medium theory,it also reveals the dynamic gradual damage process of surrounding rock,the primitive phase change damage evolution mechanism and characteristics of rock mass structural plane under different working conditions,the mesoscopic damage of surround-ing rock is thought to be caused by non average of rock nonlinear material macroscopic unit,the calculation results judged in failure of tunnel surrounding rock with different step reduction in crack development trends and the num-ber of cell damage,and calculates safety factor in the sense of the safety reserve.At the same time,combining ABAQUS with RFPA -2D two different finite element models,comparatively analyzing the random medium theory and continuum theory combining strength subtraction in differences of the evaluation of surrounding rock stability.%将强度折减法引入到隧道围岩安全评价中,结合“浅埋暗挖快速施工双线小间距隧道、盾构下穿立交结构隧道和结构面含有节理、不规则裂隙的山体公路隧道”等工程实例,借助材料真实破坏分析软件 RFPA-2D,建立每个强度折减系数下的有限元模型。模型采用了黏弹性人工边界来消除边界条件对计算精度的影响,并借助随机介

  17. Differences between nicotine-abstinent smokers and non-smokers in terms of visuospatial attention and inhibition before and after single-blind nicotine administration

    NARCIS (Netherlands)

    Logemann, H. N A; Böcker, K. B E; Deschamps, P. K H; Kemner, C.; Kenemans, J. L.

    2014-01-01

    The cholinergic system is implicated in visuospatial attention and inhibition, however the exact role is still unclear. Two key mechanisms in visuospatial attention are bias and disengagement. Bias refers to neuronal signals that enhance the sensitivity of the sensory cortex, disengagement is the

  18. Visuospatial properties of caudal area 7b in Macaca fascicularis

    Institute of Scientific and Technical Information of China (English)

    Hui-Hui JIANG; Ying-Zhou HU; Jian-Hong WANG; Yuan-Ye MA; Xin-Tian HU

    2013-01-01

    To proceed from sensation to movement,integration and transformation of information from different senses and reference frames are required.Several brain areas are involved in this transformation process,but previous neuroanatomical and neurophysiological studies have implicated the caudal area 7b as one particular component of this transformation system.In this study,we present the first quantitative report on the spatial coding properties of caudal area 7b.The results showed that neurons in this area had intermediate component characteristics in the transformation system; the area contained bimodal neurons,and neurons in this area encode spatial information using a hybrid reference frame.These results provide evidence that caudal area 7b may belong to the reference frame transformation system,thus contributing to our general understanding of the transformation system.

  19. Contribution of visuospatial attention, short-term memory and executive functions to performance in number interval bisection.

    Science.gov (United States)

    Ranzini, Mariagrazia; Carbè, Katia; Gevers, Wim

    2017-05-01

    Number interval bisection consists of estimating the mid-number within a pair (1-9=>5). Healthy adults and right-brain damage patients can show biased performance in this task, underestimating and overestimating the mid-number, respectively. The role of visuospatial attention during this task, and its interplay with other cognitive abilities (e.g., working memory) is still object of debate. In this study we explored the relation between visuospatial attention and individual differences in working memory and executive functions during number interval bisection. To manipulate the deployment of visuospatial attention, healthy participants tracked a dot moving to the left or moving to the right while bisecting numerical intervals. We also collected information concerning verbal and visuospatial short-term memory span, and concerning verbal and visuospatial fluency scores. Beside replicating what is typically observed in this task (e.g., underestimation bias), a correlation was observed between verbal short-term memory and bisection bias, and an interesting relation between performance in the number interval bisection, verbal short-term memory, and visuospatial attention. Specifically, performance of those participants with low verbal span was affected by the direction of the moving dot, underestimating at a larger extent when the dot moved leftward than rightward. Finally, it was also observed that participants' verbal fluency ability contributed in the generation of biases in the numerical task. The finding of the involvement of abilities belonging to the verbal domain contributes to unveil the multi-componential nature of number interval bisection. Considering the debate on the nature of number interval bisection and its use in the clinical assessment of deficits following brain damage, this finding may be interesting also from a clinical perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Associations of symptoms and subtypes of attention-deficit hyperactivity disorder with visuospatial planning ability in youth.

    Science.gov (United States)

    Chiang, Huey-Ling; Huang, Lin-Wan; Gau, Susan Shur-Fen; Shang, Chi-Yung

    2013-09-01

    Little is known about which ADHD core symptom or subtype is most associated with visuospatial planning deficit. This issue was investigated in a sample of 408 youths with current DSM-IV diagnosis of ADHD, and 332 youths without lifetime ADHD, aged 8-17 years (mean age 12.02±2.24). All the participants and their mothers were interviewed using the Chinese Kiddie Epidemiologic version of the Schedule for Affective Disorders and Schizophrenia to obtain information about ADHD symptoms and diagnosis and other psychiatric disorders. In addition to clinical assessments, the participants were assessed with the WISC-III and the Stocking of Cambridge task of the Cambridge Neuropsychological Test Automated Battery. Multi-level regression models were used for data analysis. The results showed that univariate analyses revealed that inattention, hyperactivity, and impulsivity were significantly associated with visuospatial planning, and the magnitude of such association was amplified with increased task difficulties. Only inattention independently predicted visuospatial planning in a model that included all three ADHD symptoms. After further controlling for comorbidity, age of assessment, treatment with methylphenidate, and Full-scale IQ, inattention was still independently associated with visuospatial planning indexed by mean moves needed to solve problems. In subtype comparison, participants with combined subtype and those with prominently inattentive subtype, rather than prominently hyperactivity/impulsivity subtype, had poorer visuospatial planning performance. Our findings indicate that inattention is independently associated with impaired visuospatial planning, and dimensional approach retains the important distinction among ADHD symptoms than subtype approach in understanding the neuropsychological functioning of ADHD.

  1. Definition of a visuospatial dimension as a step forward in the diagnostic puzzle of nonverbal learning disability.

    Science.gov (United States)

    Poletti, Michele

    2016-03-17

    Although clinically recognized for almost 50 years, the categorical distinction of specific learning disabilities due to an impairment of the nonverbal domain (nonverbal learning disability [NLD]) is still debated and controversial. Unsolved issues involve theoretical models, diagnostic criteria, rehabilitative interventions, and moderator factors. These issues are briefly overviewed to sustain the need for a shift toward dimensional approaches, as suggested by research domain criteria, as a step forward in the diagnostic puzzle of NLD. With this aim, a visuospatial dimension, or spectrum, is proposed, and then clinical conditions that may fit with its impaired side are systemized, while specifying in which conditions a visuospatial impairment may be considered an NLD.

  2. Impacts of Artificial Reefs on Surrounding Ecosystems

    Science.gov (United States)

    Manoukian, Sarine

    Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation. Acoustic systems like high-frequency multibeam sonar are efficient tools in monitoring the environmental evolution around artificial reefs, whereas water turbidity can limit visual dive and ROV inspections. A high-frequency multibeam echo sounder offers the potential of detecting fine-scale distribution of reef units, providing an unprecedented level of resolution, coverage, and spatial definition. How do artificial reefs change over time in relation to the coastal processes? How accurately does multibeam technology map different typologies of artificial modules of known size and shape? How do artificial reefs affect fish school behavior? What are the limitations of multibeam technology for investigating fish school distribution as well as spatial and temporal changes? This study addresses the above questions and presents results of a new approach for artificial reef seafloor mapping over time, based upon an integrated analysis of multibeam swath bathymetry data and geoscientific information (backscatter data analysis, SCUBA observations, physical oceanographic data, and previous findings on the geology and sedimentation processes, integrated with unpublished data) from Senigallia artificial reef, northwestern Adriatic Sea (Italy) and St. Petersburg Beach Reef, west-central Florida continental shelf. A new approach for observation of fish

  3. Smart Chips for Smart Surroundings - 4S

    NARCIS (Netherlands)

    Schuler, Eberhard; König, Ralf; Becker, Jürgen; Rauwerda, Gerard; Burgwal, van de Marcel; Smit, Gerard J.M.; Cardoso, João M.P.; Hübner, Michael

    2011-01-01

    The overall mission of the 4S project (Smart Chips for Smart Surroundings) was to define and develop efficient flexible, reconfigurable core building blocks, including the supporting tools, for future Ambient System Devices. Reconfigurability offers the needed flexibility and adaptability, it provid

  4. Experimental Study of Deformation of Surrounding Rock with Infrared Radiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-jun; AN Li-qian; REN Run-hou; FAN Shi-min; MA Nian-jie; LI Jian-hui; JI Yuan-ming

    2005-01-01

    According to the practical conditions of coal roadway in Changcun Coal Mine of Lu'an Mining Group, the deformation of rock surrounding roadway was experimentally studied by means of thermal infrared (TIR) imaging system in the process of confined compressions. It is found that the model surface TIR temperature (TIRT) changes with the increase of load. Furthermore, TIRT changes non-synchronously in different ranges such as the roof, floor, wall, corners and bolted ranges. The TIRT is higher in the location of stress concentration and bolted ranges than that in the location of stress relaxation and broken ranges. The interaction ranges of bolt and rock are determined preliminarily according to the corresponding relationship of TIRT fields and the strain fields of the surrounding rock. The new method of TIR image processing has been proved to be effective for the study of bolt support and observation of roadway stability under mine pressure.

  5. High resolution bathymetry of China seas and their surroundings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the oceanic lithospheric flexure and the worldwide bathymetric data ETOPO5, the high resolu tion bathymetry of the China seas and their surroundings is computed from altimeter derived gravity anomalies. The new bathymetry obtained by this study is higher resolution and accuracy than the widely used ETOPO5 data, mean while it shows clearly the seafioor, the tectonic characteristics and the geodynamical processes in the China seas.

  6. Video Game Training Enhances Visuospatial Working Memory and Episodic Memory in Older Adults.

    Science.gov (United States)

    Toril, Pilar; Reales, José M; Mayas, Julia; Ballesteros, Soledad

    2016-01-01

    In this longitudinal intervention study with experimental and control groups, we investigated the effects of video game training on the visuospatial working memory (WM) and episodic memory of healthy older adults. Participants were 19 volunteer older adults, who received 15 1-h video game training sessions with a series of video games selected from a commercial package (Lumosity), and a control group of 20 healthy older adults. The results showed that the performance of the trainees improved significantly in all the practiced video games. Most importantly, we found significant enhancements after training in the trained group and no change in the control group in two computerized tasks designed to assess visuospatial WM, namely the Corsi blocks task and the Jigsaw puzzle task. The episodic memory and short-term memory of the trainees also improved. Gains in some WM and episodic memory tasks were maintained during a 3-month follow-up period. These results suggest that the aging brain still retains some degree of plasticity, and that video game training might be an effective intervention tool to improve WM and other cognitive functions in older adults.

  7. Childhood poverty is associated with altered hippocampal function and visuospatial memory in adulthood

    Directory of Open Access Journals (Sweden)

    Elizabeth R. Duval

    2017-02-01

    Full Text Available Childhood poverty is a risk factor for poorer cognitive performance during childhood and adulthood. While evidence linking childhood poverty and memory deficits in adulthood has been accumulating, underlying neural mechanisms are unknown. To investigate neurobiological links between childhood poverty and adult memory performance, we used functional magnetic resonance imaging (fMRI during a visuospatial memory task in healthy young adults with varying income levels during childhood. Participants were assessed at age 9 and followed through young adulthood to assess income and related factors. During adulthood, participants completed a visuospatial memory task while undergoing MRI scanning. Patterns of neural activation, as well as memory recognition for items, were assessed to examine links between brain function and memory performance as it relates to childhood income. Our findings revealed associations between item recognition, childhood income level, and hippocampal activation. Specifically, the association between hippocampal activation and recognition accuracy varied as a function of childhood poverty, with positive associations at higher income levels, and negative associations at lower income levels. These prospective findings confirm previous retrospective results detailing deleterious effects of childhood poverty on adult memory performance. In addition, for the first time, we identify novel neurophysiological correlates of these deficits localized to hippocampus activation.

  8. Development of a superior frontal-intraparietal network for visuo-spatial working memory.

    Science.gov (United States)

    Klingberg, Torkel

    2006-01-01

    Working memory capacity increases throughout childhood and adolescence, which is important for the development of a wide range of cognitive abilities, including complex reasoning. The spatial-span task, in which subjects retain information about the order and position of a number of objects, is a sensitive task to measure development of spatial working memory. This review considers results from previous neuroimaging studies investigating the neural correlates of this development. Older children and adolescents, with higher capacity, have been found to have higher brain activity in the intraparietal cortex and in the posterior part of the superior frontal sulcus, during the performance of working memory tasks. The structural maturation of white matter has been investigated by diffusion tensor magnetic resonance imaging (DTI). This has revealed several regions in the frontal lobes in which white matter maturation is correlated with the development of working memory. Among these is a superior fronto-parietal white matter region, located close to the grey matter regions that are implicated in the development of working memory. Furthermore, the degree of white matter maturation is positively correlated with the degree of cortical activation in the frontal and parietal regions. This suggests that during childhood and adolescence, there is development of networks related to specific cognitive functions, such as visuo-spatial working memory. These networks not only consist of cortical areas but also the white matter tracts connecting them. For visuo-spatial working memory, this network could consist of the superior frontal and intraparietal cortex.

  9. Navigation of a telepresence robot via covert visuospatial attention and real-time fMRI.

    Science.gov (United States)

    Andersson, Patrik; Pluim, Josien P W; Viergever, Max A; Ramsey, Nick F

    2013-01-01

    Brain-computer interfaces (BCIs) allow people with severe neurological impairment and without ability to control their muscles to regain some control over their environment. The BCI user performs a mental task to regulate brain activity, which is measured and translated into commands controlling some external device. We here show that healthy participants are capable of navigating a robot by covertly shifting their visuospatial attention. Covert Visuospatial Attention (COVISA) constitutes a very intuitive brain function for spatial navigation and does not depend on presented stimuli or on eye movements. Our robot is equipped with motors and a camera that sends visual feedback to the user who can navigate it from a remote location. We used an ultrahigh field MRI scanner (7 Tesla) to obtain fMRI signals that were decoded in real time using a support vector machine. Four healthy subjects with virtually no training succeeded in navigating the robot to at least three of four target locations. Our results thus show that with COVISA BCI, realtime robot navigation can be achieved. Since the magnitude of the fMRI signal has been shown to correlate well with the magnitude of spectral power changes in the gamma frequency band in signals measured by intracranial electrodes, the COVISA concept may in future translate to intracranial application in severely paralyzed people.

  10. Video game training enhances visuospatial working memory and episodic memory in older adults

    Directory of Open Access Journals (Sweden)

    Pilar eToril

    2016-05-01

    Full Text Available In this longitudinal intervention study with experimental and control groups, we investigated the effects of video game training on the visuospatial working memory and episodic memory of healthy older adults. Participants were 19 volunteer older adults, who received 15 1-hr video game training sessions with a series of video games selected from a commercial package (Lumosity, and a control group of 20 healthy older adults. The results showed that the performance of the trainees improved significantly in all the practiced video games. Most importantly, we found significant enhancements after training in the trained group and no change in the control group in two computerized tasks designed to assess visuospatial working memory, namely the Corsi blocks task and the Jigsaw puzzle task. The episodic memory and short-term memory of the trainees also improved. Gains in some working memory and episodic memory tasks were maintained during a 3-month follow-up period. These results suggest that the aging brain still retains some degree of plasticity, and that video game training might be an effective intervention tool to improve working memory and other cognitive functions in older adults.

  11. Visuospatial working memory in very preterm and term born children--impact of age and performance.

    Science.gov (United States)

    Mürner-Lavanchy, I; Ritter, B C; Spencer-Smith, M M; Perrig, W J; Schroth, G; Steinlin, M; Everts, R

    2014-07-01

    Working memory is crucial for meeting the challenges of daily life and performing academic tasks, such as reading or arithmetic. Very preterm born children are at risk of low working memory capacity. The aim of this study was to examine the visuospatial working memory network of school-aged preterm children and to determine the effect of age and performance on the neural working memory network. Working memory was assessed in 41 very preterm born children and 36 term born controls (aged 7-12 years) using functional magnetic resonance imaging (fMRI) and neuropsychological assessment. While preterm children and controls showed equal working memory performance, preterm children showed less involvement of the right middle frontal gyrus, but higher fMRI activation in superior frontal regions than controls. The younger and low-performing preterm children presented an atypical working memory network whereas the older high-performing preterm children recruited a working memory network similar to the controls. Results suggest that younger and low-performing preterm children show signs of less neural efficiency in frontal brain areas. With increasing age and performance, compensational mechanisms seem to occur, so that in preterm children, the typical visuospatial working memory network is established by the age of 12 years. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Childhood poverty is associated with altered hippocampal function and visuospatial memory in adulthood.

    Science.gov (United States)

    Duval, Elizabeth R; Garfinkel, Sarah N; Swain, James E; Evans, Gary W; Blackburn, Erika K; Angstadt, Mike; Sripada, Chandra S; Liberzon, Israel

    2017-02-01

    Childhood poverty is a risk factor for poorer cognitive performance during childhood and adulthood. While evidence linking childhood poverty and memory deficits in adulthood has been accumulating, underlying neural mechanisms are unknown. To investigate neurobiological links between childhood poverty and adult memory performance, we used functional magnetic resonance imaging (fMRI) during a visuospatial memory task in healthy young adults with varying income levels during childhood. Participants were assessed at age 9 and followed through young adulthood to assess income and related factors. During adulthood, participants completed a visuospatial memory task while undergoing MRI scanning. Patterns of neural activation, as well as memory recognition for items, were assessed to examine links between brain function and memory performance as it relates to childhood income. Our findings revealed associations between item recognition, childhood income level, and hippocampal activation. Specifically, the association between hippocampal activation and recognition accuracy varied as a function of childhood poverty, with positive associations at higher income levels, and negative associations at lower income levels. These prospective findings confirm previous retrospective results detailing deleterious effects of childhood poverty on adult memory performance. In addition, for the first time, we identify novel neurophysiological correlates of these deficits localized to hippocampus activation.

  13. Association of a Nonsynonymous Variant of DAOA with Visuospatial Ability in a Bipolar Family Sample

    Science.gov (United States)

    Soronen, Pia; Silander, Kaisa; Antila, Mervi; Palo, Outi M.; Tuulio-Henriksson, Annamari; Kieseppä, Tuula; Ellonen, Pekka; Wedenoja, Juho; Turunen, Joni A.; Pietiläinen, Olli P.H.; Hennah, William; Lönnqvist, Jouko; Peltonen, Leena; Partonen, Timo; Paunio, Tiina

    2008-01-01

    Background Bipolar disorder and schizophrenia are hypothesized to share some genetic background. Methods In a two-phase study, we evaluated the effect of five promising candidate genes for psychotic disorders, DAOA, COMT, DTNBP1, NRG1, and AKT1, on bipolar spectrum disorder, psychotic disorder, and related cognitive endophenotypes in a Finnish family-based sample ascertained for bipolar disorder. Results In initial screening of 362 individuals from 63 families, we found only marginal evidence for association with the diagnosis-based dichotomous classification. Those associations did not strengthen when we genotyped the complete sample of 723 individuals from 180 families. We observed a significant association of DAOA variants rs3916966 and rs2391191 with visuospatial ability (Quantitative Transmission Disequilibrium Test [QTDT]; p = 4 × 10−6 and 5 × 10−6, respectively) (n = 159) with the two variants in almost complete linkage disequilibrium. The COMT variant rs165599 also associated with visuospatial ability, and in our dataset, we saw an additive effect of DAOA and COMT variants on this neuropsychological trait. Conclusions The ancestral allele (Arg) of the nonsynonymous common DAOA variant rs2391191 (Arg30Lys) was found to predispose to impaired performance. The DAOA gene may play a role in predisposing individuals to a mixed phenotype of psychosis and mania and to impairments in related neuropsychological traits. PMID:18466879

  14. Individual differences in afterimage persistence: relationships to hypnotic susceptibility and visuospatial skills.

    Science.gov (United States)

    Atkinson, R P; Crawford, H J

    1992-01-01

    To investigate the moderating role of individual differences in hypnotic susceptibility and visuospatial skills on afterimage persistence, we presented a codable (cross) flash of light to 40 men and 46 women who had been dark adapted for 20 min. In an unrelated classroom setting, subjects had previously been given two standardized scales of hypnotic susceptibility (Harvard Group Scale of Hypnotic Susceptibility, Shor & Orne, 1962; Group Stanford Hypnotic Susceptibility Scale, Form C, Crawford & Allen, 1982) and the Mental Rotations Test (Vandenberg & Kuse, 1978). The first afterimage interval and the afterimage duration correlated significantly with hypnotic responsiveness, supporting Wallace (1979), but did not show the anticipated relationships with mental rotation visuospatial skills. Individuals in the high hypnotizable group had (a) significantly longer afterimage intervals between its first appearance and first disappearance than did those in medium or low groups, as well as (b) significantly longer afterimages between the first appearance and the final disappearance than did those in low groups, but those in medium groups did not differ significantly from the other groups. Discriminant analysis using the afterimage persistence measures classified correctly 65.2% of high hypnotizables, 37.5% of medium hypnotizables, and 54.8% of low hypnotizables. Hypothesized cognitive skills that assist in the maintenance of afterimages and underlie hypnotic susceptibility include abilities to maintain focused attention and resist distractions over time and to maintain vivid visual images.

  15. The Interstellar Cloud Surrounding the Solar System

    Science.gov (United States)

    Frisch, P. C.

    Ultraviolet spectral data of nearby stars indicate that the cloud surrounding the solar system has an average neutral density n(HI)~0.1 cm-3, temperature ~6800 K, and turbulence ~1.7 km/s. Comparisons between the anomalous cosmic ray data and ultraviolet data suggest that the electron density is in the range n(e-)~0.22 to 0.44 cm-3. This cloud is flowing past the Sun from a position centered in the Norma-Lupis region. The cloud properties are consistent with interstellar gas which originated as material evaporated from the surfaces of embedded clouds in the Scorpius-Centaurus Association, and which was then displaced towards the Sun by a supernova event about 4 Myrs ago. The Sun and surrounding cloud velocities are nearly perpendicular in space, and this cloud is sweeping past the Sun. The morphology of this cloud can be reconstructed by assuming that the cloud moves in a direction parallel to the surface normal. With this assumption, the Sun entered the surrounding cloud 2000 to 8000 years ago, and is now about 0.05 to 0.16 pc from the cloud surface. Prior to its recent entry into the surrounding cloud complex, the Sun was embedded in a region of space with average density lower than 0.0002 cm-3. If a denser cloud velocity component seen towards alpha Cen A,B is real, it will encounter the solar system within 50,000 yr. The nearby magnetic field seen upwind has a spatial orientation that is parallel to the cloud surface. The nearby star Sirius is viewed through the wake of the solar system, but this direction also samples the hypothetical cloud interface. Comparisons of anomalous cosmic ray and interstellar absorption line data suggest that trace elements in the surrounding cloud are in ionization equilibrium. Data towards nearby white dwarfs indicate partial helium ionization, N(N(HI)(/N(HeI)>~13.7, which is consistent with pickup ion data within the solar system if less than 40% hydrogen ionization occurs in the heliopause region. However, the white dwarfs may

  16. Persistent Confusion and Controversy Surrounding Gene Patents

    Science.gov (United States)

    Guerrini, Christi J.; Majumder, Mary A.; McGuire, Amy L.

    2016-01-01

    There is persistent confusion and controversy surrounding basic issues of patent law relevant to the genomics industry. Uncertainty and conflict can lead to the adoption of inefficient practices and exposure to liability. The development of patent-specific educational resources for industry members, as well as the prompt resolution of patentability rules unsettled by recent U.S. Supreme Court decisions, are therefore urgently needed. PMID:26849516

  17. Where were those rabbits? A new paradigm to determine cerebral lateralisation of visuospatial memory function in children

    NARCIS (Netherlands)

    Groen, M.A.; Whitehouse, A.J.O.; Badcock, N.A.; Bishop, D.V.M.

    2011-01-01

    In the majority of people, functional differences are observed between the two cerebral hemispheres: language production is typically subserved by the left hemisphere and visuospatial skills by the right hemisphere. The development of this division of labour is not well understood and lateralisation

  18. The impact of recovery of visuo-spatial neglect on motor recovery of the upper paretic limb after stroke

    NARCIS (Netherlands)

    Nijboer, T.C.W.; Kollen, B.J.; Kwakkel, G.

    2014-01-01

    The aim of the current study was to investigate the longitudinal relationship between improvements of synergism and strength of the upper paretic limb and severity of visuo-spatial neglect during the first 52 weeks post-stroke. The longitudinal association between severity of VSN and motor impairmen

  19. The Impact of Recovery of Visuo-Spatial Neglect on Motor Recovery of the Upper Paretic Limb after Stroke

    NARCIS (Netherlands)

    Nijboer, Tanja C. W.; Kollen, Boudewijn J.; Kwakkel, Gert

    2014-01-01

    The aim of the current study was to investigate the longitudinal relationship between improvements of synergism and strength of the upper paretic limb and severity of visuo-spatial neglect during the first 52 weeks post-stroke. The longitudinal association between severity of VSN and motor impairmen

  20. Computerized Memory Training Leads to Sustained Improvement in Visuospatial Short-Term Memory Skills in Children with Down Syndrome

    Science.gov (United States)

    Bennett, Stephanie J.; Holmes, Joni; Buckley, Sue

    2013-01-01

    This study evaluated the impact of a computerized visuospatial memory training intervention on the memory and behavioral skills of children with Down syndrome. Teaching assistants were trained to support the delivery of a computerized intervention program to individual children over a 10-16 week period in school. Twenty-one children aged 7-12…

  1. Computerized Memory Training Leads to Sustained Improvement in Visuospatial Short-Term Memory Skills in Children with Down Syndrome

    Science.gov (United States)

    Bennett, Stephanie J.; Holmes, Joni; Buckley, Sue

    2013-01-01

    This study evaluated the impact of a computerized visuospatial memory training intervention on the memory and behavioral skills of children with Down syndrome. Teaching assistants were trained to support the delivery of a computerized intervention program to individual children over a 10-16 week period in school. Twenty-one children aged 7-12…

  2. Explaining the relationship between number line estimation and mathematical achievement: The role of visuomotor integration and visuospatial skills.

    Science.gov (United States)

    Simms, Victoria; Clayton, Sarah; Cragg, Lucy; Gilmore, Camilla; Johnson, Samantha

    2016-05-01

    Performance on number line tasks, typically used as a measure of numerical representations, are reliably related to children's mathematical achievement. However, recent debate has questioned what precisely performance on the number line estimation task measures. Specifically, there has been a suggestion that this task may measure not only numerical representations but also proportional judgment skills; if this is the case, then individual differences in visuospatial skills, not just the precision of numerical representations, may explain the relationship between number line estimation and mathematical achievement. The current study investigated the relationships among visuospatial skills, visuomotor integration, number line estimation, and mathematical achievement. In total, 77 children were assessed using a number line estimation task, a standardized measure of mathematical achievement, and tests of visuospatial skills and visuomotor integration. The majority of measures were significantly correlated. In addition, the relationship between one metric from the number line estimation task (R(2)LIN) and mathematical achievement was fully explained by visuomotor integration and visuospatial skill competency. These results have important implications for understanding what the number line task measures as well as the choice of number line metric for research purposes.

  3. Visuo-spatial processing in a dynamic and a static working memory paradigm in schizophrenia

    DEFF Research Database (Denmark)

    Cocchi, Luca; Schenk, Françoise; Volken, Henri

    2007-01-01

    patients with schizophrenia and matched controls in a new working memory paradigm involving dynamic (the Ball Flight Task - BFT) or static (the Static Pattern Task - SPT) visual stimuli. In the BFT, the responses of the patients were apparently based on the retention of the last set of segments...... of the perceived trajectory, whereas control subjects relied on a more global strategy. We assume that the patients' performances are the result of a reduced capacity in chunking visual information since they relied mainly on the retention of the last set of segments. This assumption is confirmed by the poor...

  4. Visuo-spatial processing in a dynamic and a static working memory paradigm in schizophrenia

    DEFF Research Database (Denmark)

    Cocchi, Luca; Schenk, Françoise; Volken, Henri

    2007-01-01

    patients with schizophrenia and matched controls in a new working memory paradigm involving dynamic (the Ball Flight Task - BFT) or static (the Static Pattern Task - SPT) visual stimuli. In the BFT, the responses of the patients were apparently based on the retention of the last set of segments...

  5. Modulation of memory and visuospatial processes by biperiden and rivastigmine in elderly healthy subjects.

    NARCIS (Netherlands)

    Wezenberg, E.; Verkes, R.J.; Sabbe, B.G.C.C.; Ruigt, G.S.F.; Hulstijn, W.

    2005-01-01

    RATIONALE: The central cholinergic system is implicated in cognitive functioning. The dysfunction of this system is expressed in many diseases like Alzheimer's disease, dementia of Lewy body, Parkinson's disease and vascular dementia. In recent animal studies, it was found that selective cholinergic

  6. Effectiveness of Visual and Verbal Prompts in Training Visuospatial Processing Skills in School Age Children

    Science.gov (United States)

    Chabani, Ellahe; Hommel, Bernhard

    2014-01-01

    Recent decades have witnessed a growing interest in intervention-based assessment to promote and enhance children's learning. In this study, we explored the potential effect of an experimental visual-spatial intervention procedure and possible training benefits of two prompting modalities: one group received training with verbal and visual…

  7. Modulation of memory and visuospatial processes by biperiden and rivastigmine in elderly healthy subjects.

    NARCIS (Netherlands)

    Wezenberg, E.; Verkes, R.J.; Sabbe, B.G.C.C.; Ruigt, G.S.F.; Hulstijn, W.

    2005-01-01

    RATIONALE: The central cholinergic system is implicated in cognitive functioning. The dysfunction of this system is expressed in many diseases like Alzheimer's disease, dementia of Lewy body, Parkinson's disease and vascular dementia. In recent animal studies, it was found that selective cholinergic

  8. The Space of an Object: Object Attention Alters the Spatial Gradient in the Surround

    Science.gov (United States)

    Kravitz, Dwight Jacob; Behrmann, Marlene

    2008-01-01

    Although object-based attention enhances perceptual processing of information appearing within the boundaries of a selected object, little is known about the consequences for information in the object's surround. The authors show that distance from an attended object's center of mass determines reaction time (RT) to targets in the surround. Of 2…

  9. Visuo-spatial memory deficits following medial temporal lobe damage: A comparison of three patient groups.

    Science.gov (United States)

    Esfahani-Bayerl, Nazli; Finke, Carsten; Braun, Mischa; Düzel, Emrah; Heekeren, Hauke R; Holtkamp, Martin; Hasper, Dietrich; Storm, Christian; Ploner, Christoph J

    2016-01-29

    The contributions of the hippocampal formation and adjacent regions of the medial temporal lobe (MTL) to memory are still a matter of debate. It is currently unclear, to what extent discrepancies between previous human lesion studies may have been caused by the choice of distinct patient models of MTL dysfunction, as disorders affecting this region differ in selectivity, laterality and mechanisms of post-lesional compensation. Here, we investigated the performance of three distinct patient groups with lesions to the MTL with a battery of visuo-spatial short-term memory tasks. Thirty-one subjects with either unilateral damage to the MTL (postsurgical lesions following resection of a benign brain tumor, 6 right-sided lesions, 5 left) or bilateral damage (10 post-encephalitic lesions, 10 post-anoxic lesions) performed a series of tasks requiring short-term memory of colors, locations or color-location associations. We have shown previously that performance in the association task critically depends on hippocampal integrity. Patients with postsurgical damage of the MTL showed deficient performance in the association task, but performed normally in color and location tasks. Patients with left-sided lesions were almost as impaired as patients with right-sided lesions. Patients with bilateral post-encephalitic lesions showed comparable damage to MTL sub-regions and performed similarly to patients with postsurgical lesions in the association task. However, post-encephalitic patients showed additional impairments in the non-associative color and location tasks. A strikingly similar pattern of deficits was observed in post-anoxic patients. These results suggest a distinct cerebral organization of associative and non-associative short-term memory that was differentially affected in the three patient groups. Thus, while all patient groups may provide appropriate models of medial temporal lobe dysfunction in associative visuo-spatial short-term memory, additional deficits in

  10. Identification of -SiC surrounded by relatable surrounding diamond medium using weak Raman surface phonons

    Indian Academy of Sciences (India)

    Mohan Kumar Kuntumalla; Harish Ojha; Vadali Venkata Satya Siva Srikanth

    2013-11-01

    It is difficult to detect -SiC using micro-Raman scattering, if it is surrounded by carbon medium. Here, -SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman surface phonons. In this study, diamond/-SiC nanocomposite thin film system is considered in which nanosized -SiC crystallites are surrounded by a relatable nanodiamond medium that leads to the appearance of a weak Raman surface phonon band at about 855 cm-1. Change in the nature of the surrounding material structure and its volume content when relatable, will affect the resultant Raman response of -SiC phase as seen in the present case of diamond/-SiC nanocomposite thin films.

  11. Those are your legs: The effect of visuo-spatial viewpoint on visuo-tactile integration and body ownership

    Directory of Open Access Journals (Sweden)

    Polona ePozeg

    2015-11-01

    Full Text Available Experiencing a body part as one’s own, i.e. body ownership, depends on the integration of multisensory bodily signals (including visual, tactile, and proprioceptive information with the visual top-down signals from peripersonal space. Although it has been shown that the visuo-spatial viewpoint from where the body is seen is an important visual top-down factor for body ownership, different studies have reported diverging results. Furthermore, the role of visuo-spatial viewpoint (sometime also called first-person perspective has only been studied for hands or the whole body, but not for the lower limbs. We thus investigated whether and how leg visuo-tactile integration and leg ownership depended on the visuo-spatial viewpoint from which the legs were seen and the anatomical similarity of the visual leg stimuli. Using a virtual leg illusion, we tested the strength of visuo-tactile integration of leg stimuli using the cross-modal congruency effect (CCE as well as the subjective sense of leg ownership (assessed by a questionnaire. Fifteen participants viewed virtual legs or non-corporeal control objects, presented either from their habitual first-person viewpoint or from a viewpoint that was rotated by 90° (third-person viewpoint, while applying visuo-tactile stroking between the participants legs and the virtual legs shown on a head-mounted display. The data show that the first-person visuo-spatial viewpoint significantly boosts the visuo-tactile integration as well as the sense of leg ownership. Moreover, the viewpoint-dependent increment of the visuo-tactile integration was only found in the conditions when participants viewed the virtual legs (absent for control objects. These results confirm the importance of first person visuo-spatial viewpoint for the integration of visuo-tactile stimuli and extend findings from the upper extremity and the trunk to visuo-tactile integration and ownership for the legs.

  12. Age-related differences in cortical activity during a visuo-spatial working memory task with facial stimuli.

    Directory of Open Access Journals (Sweden)

    Flávia Schechtman Belham

    Full Text Available Emotion, importantly displayed by facial expressions, is one of the most significant memory modulators. The interaction between memory and the different emotional valences change across lifespan, while young adults (YA are expected to better recall negative events (Negativity Bias Hypothesis, older adults (OA tend to focus on positive stimuli (Positivity Effect Hypothesis. This research work aims at verifying whether cortical electrical activity of these two age groups would also be differently influenced by emotional valences in a visuo-spatial working memory task. 27 YA (13 males and 25 OA (14 males, all healthy volunteers, underwent electroencephalographic recordings (21 scalp electrodes montage, while performing the Spatial Delayed Recognition Span Task using a touch screen with different stimuli categories: neutral, positive and negative faces and geometric pictures. YA obtained higher scores than OA, and showed higher activation of theta and alpha bands in the frontal and midline regions, besides a more evident right-hemispheric asymmetry on alpha band when compared to OA. For both age groups, performance in the task was worse for positive faces than to negative and to neutral faces. Facial stimuli induced a better performance and higher alpha activation on the pre-frontal region for YA, and on the midline, occipital and left temporal regions for OA when compared to geometric figures. The superior performance of YA was expected due to the natural cognitive deficits connected to ageing, as was a better performance with facial stimuli due to the evolutionary importance of faces. These results were related to cortical activity on areas of importance for action-planning, decision making and sustained attention. Taken together, they are in accordance with the Negativity Bias but do not support the Positivity Effect. The methodology used was able to identify age-related differences in cortical activity during emotional mnemonic processing and

  13. Decline in Memory, Visuospatial Ability, and Crystalized Cognitive Abilities in Older Adults: Normative Aging or Terminal Decline?

    Directory of Open Access Journals (Sweden)

    R. Bendayan

    2017-01-01

    Full Text Available The aim of this study is to explore the pattern of change in multiple measures of cognitive abilities in a sample of oldest-old adults, comparing two different time metrics (chronological age and time to death and therefore examining both underlying conceptual assumptions (age-related change and terminal decline. Moreover, the association with individual characteristics as sex, education, and dementia diagnosis was also examined. Measures of cognitive status (Mini-Mental State Examination and the Swedish Clock Test and tests of crystallized (knowledge and synonyms, memory (verbal memory, nonverbal long-term memory, recognition and correspondence, and short-term memory, and visuospatial ability were included. The sample consisted of 671 older Swedish adult participants of the OCTO Twin Study. Linear mixed models with random coefficients were used to analyse change patterns and BIC indexes were used to compare models. Results showed that the time to death model was the best option in analyses of change in all the cognitive measures considered (except for the Information Test. A significant cognitive decline over time was found for all variables. Individuals diagnosed with dementia had lower scores at the study entrance and a faster decline. More educated individuals performed better in all the measures of cognition at study entry than those with poorer education, but no differences were found in the rate of change. Differences were found in age, sex, or time to death at baseline across the different measures. These results support the terminal decline hypothesis when compared to models assuming that cognitive changes are driven by normative aging processes.

  14. Developmental trajectories of verbal and visuospatial abilities in healthy older adults: comparison of the hemisphere asymmetry reduction in older adults model and the right hemi-ageing model.

    Science.gov (United States)

    Hatta, Takeshi; Iwahara, Akihiko; Hatta, Taketoshi; Ito, Emi; Hatta, Junko; Hotta, Chie; Nagahara, Naoko; Fujiwara, Kazumi; Hamajima, Nobuyuki

    2015-01-01

    Two models of cognitive ageing, the hemisphere asymmetry reduction in older adults (HAROLD) model and the right hemi-ageing model, were compared based upon the verbal memory and visuospatial task performance of 338 elderly participants. Comparison of the developmental trajectories for four age groups (50s, 60s, 70s and 80s) supported the HAROLD model, but not the right hemi-ageing model. Performance differences between the verbal memory and visuospatial tasks in the earlier age groups decreased in the later age groups. There was a sex difference in the cognitive-decline trajectories for verbal and visuospatial task performance after the 50s.

  15. Explaining preferences for home surroundings and locations

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter

    2011-01-01

    : avoiding social nuisances, preferring social homogeneity and living close to one’s social network and place of origin. The study shows that most people have many detailed preferences, whereas some have very few. This confirms an earlier theory that some people are very connected to certain places...... with given characteristics and thus do not have priorities regarding home surroundings and locations. For others, mostly young people and singles, home is just a place to sleep and relax, whereas life is lived elsewhere. For this group, there are only preferences for location and there are few specific...

  16. Handedness and Graspability Modify Shifts of Visuospatial Attention to Near-Hand Objects

    Science.gov (United States)

    Colman, Hayley A.; Remington, Roger W.; Kritikos, Ada

    2017-01-01

    We examined how factors related to the internal representation of the hands (handedness and grasping affordances) influence the distribution of visuospatial attention near the body. Left and right handed participants completed a covert visual cueing task, discriminating between two target shapes. In Experiment 1, participants responded with either their dominant or non-dominant hand. In Experiment 2, the non-responding hand was positioned below one of two target placeholders, aligned with the shoulder. In Experiment 3 the near-monitor hand was positioned under the placeholder in the opposite region of hemispace, crossed over the body midline. For Experiments 2 & 3, in blocked trials the palmar and back-of hand surfaces were directed towards the target placeholder such that targets appeared towards either the graspable or non-graspable space of the hand respectively. In Experiment 2, both left and right handers displayed larger accuracy cueing effects for targets near versus distant from the graspable space of the right hand. Right handers also displayed larger response time cueing effects for objects near the graspable versus non-graspable region of their dominant hand but not for their non-dominant hands. These effects were not evident for left-handers. In Experiment 3, for right handers, accuracy biases for near hand targets were still evident when the hand was crossed over the body midline, and reflected hand proximity but not functional orientation biases. These findings suggest that biased visuospatial attention enhances object identity discrimination near hands and that these effects are particularly enhanced for right-handers. PMID:28125635

  17. Real-time decoding of the direction of covert visuospatial attention

    Science.gov (United States)

    Andersson, Patrik; Ramsey, Nick F.; Raemaekers, Mathijs; Viergever, Max A.; Pluim, Josien P. W.

    2012-08-01

    Brain-computer interfaces (BCIs) make it possible to translate a person’s intentions into actions without depending on the muscular system. Brain activity is measured and classified into commands, thereby creating a direct link between the mind and the environment, enabling, e.g., cursor control or navigation of a wheelchair or robot. Most BCI research is conducted with scalp EEG but recent developments move toward intracranial electrodes for paralyzed people. The vast majority of BCI studies focus on the motor system as the appropriate target for recording and decoding movement intentions. However, properties of the visual system may make the visual system an attractive and intuitive alternative. We report on a study investigating feasibility of decoding covert visuospatial attention in real time, exploiting the full potential of a 7 T MRI scanner to obtain the necessary signal quality, capitalizing on earlier fMRI studies indicating that covert visuospatial attention changes activity in the visual areas that respond to stimuli presented in the attended area of the visual field. Healthy volunteers were instructed to shift their attention from the center of the screen to one of four static targets in the periphery, without moving their eyes from the center. During the first part of the fMRI-run, the relevant brain regions were located using incremental statistical analysis. During the second part, the activity in these regions was extracted and classified, and the subject was given visual feedback of the result. Performance was assessed as the number of trials where the real-time classifier correctly identified the direction of attention. On average, 80% of trials were correctly classified (chance level <25%) based on a single image volume, indicating very high decoding performance. While we restricted the experiment to five attention target regions (four peripheral and one central), the number of directions can be higher provided the brain activity patterns can

  18. Negative mental imagery in public speaking anxiety: Forming cognitive resistance by taxing visuospatial working memory.

    Science.gov (United States)

    Homer, Sophie R; Deeprose, Catherine; Andrade, Jackie

    2016-03-01

    This study sought to reconcile two lines of research. Previous studies have identified a prevalent and causal role of negative imagery in social phobia and public speaking anxiety; others have demonstrated that lateral eye movements during visualisation of imagery reduce its vividness, most likely by loading the visuospatial sketchpad of working memory. It was hypothesised that using eye movements to reduce the intensity of negative imagery associated with public speaking may reduce anxiety resulting from imagining a public speaking scenario compared to an auditory control task. Forty undergraduate students scoring high in anxiety on the Personal Report of Confidence as a Speaker scale took part. A semi-structured interview established an image that represented the participant's public speaking anxiety, which was then visualised during an eye movement task or a matched auditory task. Reactions to imagining a hypothetical but realistic public speaking scenario were measured. As hypothesised, representative imagery was established and reduced in vividness more effectively by the eye movement task than the auditory task. The public speaking scenario was then visualised less vividly and generated less anxiety when imagined after performing the eye movement task than after the auditory task. Self-report measures and a hypothetical scenario rather than actual public speaking were used. Replication is required in larger as well as clinical samples. Visuospatial working memory tasks may preferentially reduce anxiety associated with personal images of feared events, and thus provide cognitive resistance which reduces emotional reactions to imagined, and potentially real-life future stressful experiences. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Endogenous visuospatial attention increases visual awareness independent of visual discrimination sensitivity.

    Science.gov (United States)

    Vernet, Marine; Japee, Shruti; Lokey, Savannah; Ahmed, Sara; Zachariou, Valentinos; Ungerleider, Leslie G

    2017-08-12

    Visuospatial attention often improves task performance by increasing signal gain at attended locations and decreasing noise at unattended locations. Attention is also believed to be the mechanism that allows information to enter awareness. In this experiment, we assessed whether orienting endogenous visuospatial attention with cues differentially affects visual discrimination sensitivity (an objective task performance) and visual awareness (the subjective feeling of perceiving) during the same discrimination task. Gabor patch targets were presented laterally, either at low contrast (contrast stimuli) or at high contrast embedded in noise (noise stimuli). Participants reported their orientation either in a 3-alternative choice task (clockwise, counterclockwise, unknown) that allowed for both objective and subjective reports, or in a 2-alternative choice task (clockwise, counterclockwise) that provided a control for objective reports. Signal detection theory models were fit to the experimental data: estimated perceptual sensitivity reflected objective performance; decision criteria, or subjective biases, were a proxy for visual awareness. Attention increased sensitivity (i.e., improved objective performance) for the contrast, but not for the noise stimuli. Indeed, with the latter, attention did not further enhance the already high target signal or reduce the already low uncertainty on its position. Interestingly, for both contrast and noise stimuli, attention resulted in more liberal criteria, i.e., awareness increased. The noise condition is thus an experimental configuration where people think they see the targets they attend to better, even if they do not. This could be explained by an internal representation of their attentional state, which influences awareness independent of objective visual signals. Copyright © 2017. Published by Elsevier Ltd.

  20. Computerized Spatial-Delayed Recognition Span Task: a specific tool to assess visuospatial working memory

    Directory of Open Access Journals (Sweden)

    Corina eSatler

    2015-04-01

    Full Text Available A new tablet device version (IOS platform of the Spatial Delayed Recognition Span Task (SDRST was developed with the aim of investigating visuospatial Working Memory (WM abilities based on touchscreen technology. This new WM testing application will be available to download for free in Apple Store app (SDRST app. In order to verify the feasibility of this computer-based task, we conducted three experiments with different manipulations and groups of participants. We were interested in investigating if (1 the SDRST is sensitive enough to tap into cognitive differences brought by ageing and dementia; (2 different experimental manipulations work successfully; (3 cortical brain activations seen in other WM tasks are also demonstrated here; and (4 non-human primates are able to answer the task. Performance (scores and response time was better for young than older adults and higher for the latter when compared to Alzheimer’s disease patients. All groups performed better with facial stimuli than with images of scenes and with emotional than with neutral stimuli. Electrophysiology data showed activation on prefrontal and frontal areas of scalp, theta band activity on the midline area, and gamma activity in left temporal area. There are all scalp regions known to be related to attention and WM. Besides those data, our sample of adult captive capuchin monkeys (Sapajus libidinosus answered the task above chance level. Taken together, these results corroborate the reliability of this new computer-based SDRST as a measure of visuospatial WM in clinical and non-clinical populations as well as in non-human primates. Its tablet app allows the task to be administered in a wide range of settings, including hospitals, homes, schools, laboratories, universities, and research institutions.

  1. Problems Surrounding Probation In The South African Public Service

    Directory of Open Access Journals (Sweden)

    Z. Baloyi

    2006-11-01

    Full Text Available The aim of the study was to investigate problems surrounding probation periods in the South African Public Service. A qualitative study was conducted to determine the views of both probationers and supervisors managing the probation process. Data was gathered by means of focus groups and individual interviews. Nine key areas were identified as being problematic, viz. clarity regarding the purpose of probation, lack of proper guidelines, the duration of probation, rotation during probation, lack of training, poor management of probation, performance management, anxiety and stress, power and authority. Recommendations are made concerning possible interventions.

  2. Opportunity's Surroundings After Sol 1820 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). South is at the center; north at both ends. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  3. Exploiting Surrounding Text for Retrieving Web Images

    Directory of Open Access Journals (Sweden)

    S. A. Noah

    2008-01-01

    Full Text Available Web documents contain useful textual information that can be exploited for describing images. Research had been focused on representing images by means of its content (low level description such as color, shape and texture, little research had been directed to exploiting such textual information. The aim of this research was to systematically exploit the textual content of HTML documents for automatically indexing and ranking of images embedded in web documents. A heuristic approach for locating and assigning weight surrounding web images and a modified tf.idf weighting scheme was proposed. Precision-recall measures of evaluation had been conducted for ten queries and promising results had been achieved. The proposed approach showed slightly better precision measure as compared to a popular search engine with an average of 0.63 and 0.55 relative precision measures respectively.

  4. The Effects of Repeat Testing, Malingering, and Traumatic Brain Injury on Computerized Measures of Visuospatial Memory Span.

    Science.gov (United States)

    Woods, David L; Wyma, John M; Herron, Timothy J; Yund, E W

    2015-01-01

    Spatial span tests (SSTs) such as the Corsi Block Test (CBT) and the SST of the Wechsler Memory Scale are widely used to assess deficits in spatial working memory. We conducted three experiments to evaluate the test-retest reliability and clinical sensitivity of a new computerized spatial span test (C-SST) that incorporates psychophysical methods to improve the precision of spatial span measurement. In Experiment 1, we analyzed C-SST test-retest reliability in 49 participants who underwent three test sessions at weekly intervals. Intraclass correlation coefficients (ICC) were higher for a psychophysically derived mean span (MnS) metric (0.83) than for the maximal span and total correct metrics used in traditional spatial-span tests. Response times (ReTs) also showed high ICCs (0.93) that correlated negatively with MnS scores and correlated positively with response-time latencies from other tests of processing speed. Learning effects were insignificant. Experiment 2 examined the performance of Experiment 1 participants when instructed to feign symptoms of traumatic brain injury (TBI): 57% showed abnormal MnS z-scores. A MnS z-score cutoff of 3.0 correctly classified 36% of simulated malingerers and 91% of the subgroup of 11 control participants with abnormal spans. Malingerers also made more substitution errors than control participants with abnormal spans (sensitivity = 43%, specificity = 91%). In addition, malingerers showed no evidence of ReT slowing, in contrast to significant abnormalities seen on other malingered tests of processing speed. As a result, differences between ReT z-scores and z-scores on other processing speed tests showed very high sensitivity and specificity in distinguishing malingering and control participants with either normal or abnormal spans. Experiment 3 examined C-SST performance in a group of patients with predominantly mild TBI: neither MnS nor ReT z-scores showed significant group-level abnormalities. The C-SST improves the

  5. Improving the Efficacy of ERP-Based BCIs Using Different Modalities of Covert Visuospatial Attention and a Genetic Algorithm-Based Classifier

    Science.gov (United States)

    Marchetti, Mauro; Onorati, Francesco; Matteucci, Matteo; Mainardi, Luca; Piccione, Francesco; Silvoni, Stefano; Priftis, Konstantinos

    2013-01-01

    We investigated whether the covert orienting of visuospatial attention can be effectively used in a brain-computer interface guided by event-related potentials. Three visual interfaces were tested: one interface that activated voluntary orienting of visuospatial attention and two interfaces that elicited automatic orienting of visuospatial attention. We used two epoch classification procedures. The online epoch classification was performed via Independent Component Analysis, and then it was followed by fixed features extraction and support vector machines classification. The offline epoch classification was performed by means of a genetic algorithm that permitted us to retrieve the relevant features of the signal, and then to categorise the features with a logistic classifier. The offline classification, but not the online one, allowed us to differentiate between the performances of the interface that required voluntary orienting of visuospatial attention and those that required automatic orienting of visuospatial attention. The offline classification revealed an advantage of the participants in using the “voluntary” interface. This advantage was further supported, for the first time, by neurophysiological data. Moreover, epoch analysis was performed better with the “genetic algorithm classifier” than with the “independent component analysis classifier”. We suggest that the combined use of voluntary orienting of visuospatial attention and of a classifier that permits feature extraction ad personam (i.e., genetic algorithm classifier) can lead to a more efficient control of visual BCIs. PMID:23342043

  6. Improving the efficacy of ERP-based BCIs using different modalities of covert visuospatial attention and a genetic algorithm-based classifier.

    Directory of Open Access Journals (Sweden)

    Mauro Marchetti

    Full Text Available We investigated whether the covert orienting of visuospatial attention can be effectively used in a brain-computer interface guided by event-related potentials. Three visual interfaces were tested: one interface that activated voluntary orienting of visuospatial attention and two interfaces that elicited automatic orienting of visuospatial attention. We used two epoch classification procedures. The online epoch classification was performed via Independent Component Analysis, and then it was followed by fixed features extraction and support vector machines classification. The offline epoch classification was performed by means of a genetic algorithm that permitted us to retrieve the relevant features of the signal, and then to categorise the features with a logistic classifier. The offline classification, but not the online one, allowed us to differentiate between the performances of the interface that required voluntary orienting of visuospatial attention and those that required automatic orienting of visuospatial attention. The offline classification revealed an advantage of the participants in using the "voluntary" interface. This advantage was further supported, for the first time, by neurophysiological data. Moreover, epoch analysis was performed better with the "genetic algorithm classifier" than with the "independent component analysis classifier". We suggest that the combined use of voluntary orienting of visuospatial attention and of a classifier that permits feature extraction ad personam (i.e., genetic algorithm classifier can lead to a more efficient control of visual BCIs.

  7. Improving the efficacy of ERP-based BCIs using different modalities of covert visuospatial attention and a genetic algorithm-based classifier.

    Science.gov (United States)

    Marchetti, Mauro; Onorati, Francesco; Matteucci, Matteo; Mainardi, Luca; Piccione, Francesco; Silvoni, Stefano; Priftis, Konstantinos

    2013-01-01

    We investigated whether the covert orienting of visuospatial attention can be effectively used in a brain-computer interface guided by event-related potentials. Three visual interfaces were tested: one interface that activated voluntary orienting of visuospatial attention and two interfaces that elicited automatic orienting of visuospatial attention. We used two epoch classification procedures. The online epoch classification was performed via Independent Component Analysis, and then it was followed by fixed features extraction and support vector machines classification. The offline epoch classification was performed by means of a genetic algorithm that permitted us to retrieve the relevant features of the signal, and then to categorise the features with a logistic classifier. The offline classification, but not the online one, allowed us to differentiate between the performances of the interface that required voluntary orienting of visuospatial attention and those that required automatic orienting of visuospatial attention. The offline classification revealed an advantage of the participants in using the "voluntary" interface. This advantage was further supported, for the first time, by neurophysiological data. Moreover, epoch analysis was performed better with the "genetic algorithm classifier" than with the "independent component analysis classifier". We suggest that the combined use of voluntary orienting of visuospatial attention and of a classifier that permits feature extraction ad personam (i.e., genetic algorithm classifier) can lead to a more efficient control of visual BCIs.

  8. Triggered Star Formation Surrounding Wolf-Rayet Star HD 211853

    Science.gov (United States)

    Liu, Tie; Wu, Yuefang; Zhang, Huawei; Qin, Sheng-Li

    2012-05-01

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 103 cm-3 and kinematic temperature ~20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core "A," which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the "collect and collapse" process functions in this region. The star-forming activities in core "A" seem to be affected by the "radiation-driven implosion" process.

  9. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2012-05-20

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  10. The Comparison of the Visuo-Spatial Abilities of Dyslexic and Normal Students in Taiwan and Hong Kong

    Science.gov (United States)

    Wang, Li-Chih; Yang, Hsien-Ming

    2011-01-01

    This study focused on a comparison of the visuo-spatial abilities (correct rate and speed) between dyslexic and normal students in Taiwan and Hong Kong. There were a total of 120 10-12 year old students. Thirty students had been diagnosed as dyslexic in Taiwan (T.W. dyslexia) and thirty students had been diagnosed as dyslexic in Hong Kong (H.K.…

  11. Developmental Trajectories for Visuo-Spatial Attention are Altered by Prenatal Alcohol Exposure: A Longitudinal FMRI Study.

    Science.gov (United States)

    Gautam, P; Nuñez, S C; Narr, K L; Mattson, S N; May, P A; Adnams, C M; Riley, E P; Jones, K L; Kan, E C; Sowell, E R

    2015-12-01

    Functional magnetic resonance imaging (fMRI) reveals brain activation abnormalities during visuo-spatial attention and working memory among those with fetal alcohol spectrum disorders (FASD) in cross-sectional reports, but little is known about how activation changes over time during development within FASD or typically developing children. We studied 30 controls and 31 individuals with FASD over 2 years (7-14 years at first participation) with a total of 122 scans, as part of the Collaborative Initiative on Fetal Alcohol Spectrum Disorders. Despite comparable performance, there were significant group differences in visuo-spatial activation over time bilaterally in frontal, parietal, and temporal regions. Controls showed an increase in signal intensity in these multiple regions whereas FASD participants showed a decrease in brain activation. Effects were also found in 2 small independent samples from the USA, corroborating the findings from the larger group. Results suggest that the long-lasting effect of prenatal alcohol may impact the maturation of visuo-spatial attention and differentiate those with FASD from controls. Based on this first longitudinal fMRI study in FASD children, our novel findings suggest a possible neural mechanism for attention deficits common among individuals with FASD.

  12. Planning sentences while doing other things at the same time: effects of concurrent verbal and visuospatial working memory load.

    Science.gov (United States)

    Klaus, Jana; Mädebach, Andreas; Oppermann, Frank; Jescheniak, Jörg D

    2017-04-01

    This study investigated to what extent advance planning during sentence production is affected by a concurrent cognitive load. In two picture-word interference experiments in which participants produced subject-verb-object sentences while ignoring auditory distractor words, we assessed advance planning at a phonological (lexeme) and at an abstract-lexical (lemma) level under visuospatial or verbal working memory (WM) load. At the phonological level, subject and object nouns were found to be activated before speech onset with concurrent visuospatial WM load, but only subject nouns were found to be activated with concurrent verbal WM load, indicating a reduced planning scope as a function of type of WM load (Experiment 1). By contrast, at the abstract-lexical level, subject and object nouns were found to be activated regardless of type of concurrent load (Experiment 2). In both experiments, sentence planning had a more detrimental effect on concurrent verbal WM task performance than on concurrent visuospatial WM task performance. Overall, our results suggest that advance planning at the phonological level is more affected by a concurrently performed verbal WM task than advance planning at the abstract-lexical level. Also, they indicate an overlap of resources allocated to phonological planning in speech production and verbal WM.

  13. FMRI effective connectivity and TMS chronometry: complementary accounts of causality in the visuospatial judgment network.

    Directory of Open Access Journals (Sweden)

    Tom A de Graaf

    Full Text Available BACKGROUND: While traditionally quite distinct, functional neuroimaging (e.g. functional magnetic resonance imaging: fMRI and functional interference techniques (e.g. transcranial magnetic stimulation: TMS increasingly address similar questions of functional brain organization, including connectivity, interactions, and causality in the brain. Time-resolved TMS over multiple brain network nodes can elucidate the relative timings of functional relevance for behavior ("TMS chronometry", while fMRI functional or effective connectivity (fMRI EC can map task-specific interactions between brain regions based on the interrelation of measured signals. The current study empirically assessed the relation between these different methods. METHODOLOGY/PRINCIPAL FINDINGS: One group of 15 participants took part in two experiments: one fMRI EC study, and one TMS chronometry study, both of which used an established cognitive paradigm involving one visuospatial judgment task and one color judgment control task. Granger causality mapping (GCM, a data-driven variant of fMRI EC analysis, revealed a frontal-to-parietal flow of information, from inferior/middle frontal gyrus (MFG to posterior parietal cortex (PPC. FMRI EC-guided Neuronavigated TMS had behavioral effects when applied to both PPC and to MFG, but the temporal pattern of these effects was similar for both stimulation sites. At first glance, this would seem in contradiction to the fMRI EC results. However, we discuss how TMS chronometry and fMRI EC are conceptually different and show how they can be complementary and mutually constraining, rather than contradictory, on the basis of our data. CONCLUSIONS/SIGNIFICANCE: The findings that fMRI EC could successfully localize functionally relevant TMS target regions on the single subject level, and conversely, that TMS confirmed an fMRI EC identified functional network to be behaviorally relevant, have important methodological and theoretical implications. Our

  14. The lithosphere-asthenosphere Italy and surroundings

    CERN Document Server

    Panza, G F; Chimera, G; Pontevivo, A; Raykova, R

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by surface wave velocity tomography and non-linear inversion. Maps of the Moho depth, of the thickness of the lithosphere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, identified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the principal recent volcanoes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria a lithospheric doubling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenosphere properties delineat...

  15. The lithosphere-asthenosphere: Italy and surroundings

    Institute of Scientific and Technical Information of China (English)

    GiulianoF.Panza; AntonellaPontevivo; GiordanoChimera; RenetaRaykova; AbdelkrimAoudia

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by sur-face wave velocity tomography and non-linear inversion.Maps of the Moho depth, of the thickness of the lithos-phere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, iden-tified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the prmctpat recent votca-noes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria, a lithospheric dou-bling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenos-phere properties delineate a differentiation between the northern and the southern sectors of the Adriatic Sea,likely attesting the fragmentation of Adria.

  16. Reducing chronic visuo-spatial neglect following right hemisphere stroke through instrument playing

    Directory of Open Access Journals (Sweden)

    Rebeka eBodak

    2014-06-01

    Full Text Available Unilateral visuo-spatial neglect is a neuropsychological syndrome commonly resulting from right hemisphere strokes at the temporo-parietal junction of the infero-posterior parietal cortex. Neglect is characterised by reduced awareness of stimuli presented on patients’ contralesional side of space and has previously been shown to be improved by a number of motivational influences, including listening to preferred music and numerical sequence completion. Here we examined whether playing musical sequences on chime bars – an instrument with a horizontal alignment – would bring about clinically significant improvement in chronic neglect.Two left neglect patients completed an intervention comprising four weekly 30-minute music sessions involving playing scales and familiar melodies on chime bars from right to left. Two cancellation tests (Mesulam shape, BIT star, the line bisection test, and the neglect subtest from the computerised TAP (Test for Attentional Performance battery were administered three times during a preliminary baseline phase, before and after each music session during the rehabilitation phase to investigate short-term effects, as well as one week after the last intervention session to investigate whether any effects would persist.Both patients demonstrated significant short-term and longer-lasting improvements on the Mesulam shape cancellation test. One patient also showed longer-lasting effects on the BIT star cancellation test and scored in the normal range one week after the intervention. These findings provide preliminary evidence that active music-making may help neglect patients attend more to their affected side.

  17. Type 1 Diabetes Modifies Brain Activation in Young Patients While Performing Visuospatial Working Memory Tasks

    Directory of Open Access Journals (Sweden)

    Geisa B. Gallardo-Moreno

    2015-01-01

    Full Text Available In recent years, increasing attention has been paid to the effects of Type 1 Diabetes (T1D on cognitive functions. T1D onset usually occurs during childhood, so it is possible that the brain could be affected during neurodevelopment. We selected young patients of normal intelligence with T1D onset during neurodevelopment, no complications from diabetes, and adequate glycemic control. The purpose of this study was to compare the neural BOLD activation pattern in a group of patients with T1D versus healthy control subjects while performing a visuospatial working memory task. Sixteen patients and 16 matched healthy control subjects participated. There was no significant statistical difference in behavioral performance between the groups, but, in accordance with our hypothesis, results showed distinct brain activation patterns. Control subjects presented the expected activations related to the task, whereas the patients had greater activation in the prefrontal inferior cortex, basal ganglia, posterior cerebellum, and substantia nigra. These different patterns could be due to compensation mechanisms that allow them to maintain a behavioral performance similar to that of control subjects.

  18. Visuospatial and psychomotor aptitude predicts endovascular performance of inexperienced individuals on a virtual reality simulator.

    Science.gov (United States)

    Van Herzeele, Isabelle; O'Donoghue, Kevin G L; Aggarwal, Rajesh; Vermassen, Frank; Darzi, Ara; Cheshire, Nicholas J W

    2010-04-01

    This study evaluated virtual reality (VR) simulation for endovascular training of medical students to determine whether innate perceptual, visuospatial, and psychomotor aptitude (VSA) can predict initial and plateau phase of technical endovascular skills acquisition. Twenty medical students received didactic and endovascular training on a commercially available VR simulator. Each student treated a series of 10 identical noncomplex renal artery stenoses endovascularly. The simulator recorded performance data instantly and objectively. An experienced interventionalist rated the performance at the initial and final sessions using generic (out of 40) and procedure-specific (out of 30) rating scales. VSA were tested with fine motor dexterity (FMD, Perdue Pegboard), psychomotor ability (minimally invasive virtual reality surgical trainer [MIST-VR]), image recall (Rey-Osterrieth), and organizational aptitude (map-planning). VSA performance scores were correlated with the assessment parameters of endovascular skills at commencement and completion of training. Medical students exhibited statistically significant learning curves from the initial to the plateau performance for contrast usage (medians, 28 vs 17 mL, P generic and procedure-specific rating scales improved significantly (10 vs 25, P generic skills at the end of training (r(s) = .587, P = .006). Simulator-based training in endovascular skills improved performance in medical students. There were significant correlations between initial endovascular skill and fine motor dexterity as well as with image recall at end of the training period. In addition to current recruitment strategies, VSA may be a useful tool for predictive validity studies.

  19. Effects of dual transcranial direct current stimulation on post-stroke unilateral visuospatial neglect.

    Science.gov (United States)

    Sunwoo, Hyuk; Kim, Yun-Hee; Chang, Won Hyuk; Noh, Soojin; Kim, Eun-Jin; Ko, Myoung-Hwan

    2013-10-25

    Based on the interhemispheric inhibition model of unilateral visuospatial neglect (USN) after stroke, the effects of dual-mode transcranial direct current stimulation (tDCS) over the parietal cortices were assessed in a double-blind random-order cross-over experiment. Ten chronic right hemispheric stroke patients (4 men; mean age: 62.6 years) with USN were recruited. All participants underwent three randomly arranged tDCS sessions: (1) dual-mode, anodal tDCS over the right posterior parietal cortex (PPC) and cathodal tDCS over the left PPC; (2) single-mode, anodal tDCS over the right PPC; and (3) sham mode. Each session lasted 20min. Before and immediately after the stimulation, a line bisection test and star cancelation test were carried out. In the line bisection test, significant improvements were observed after both the dual- and the single-mode tDCS (pstimulation. Statistical analysis showed a significant interaction between time and tDCS mode, where the dual tDCS had a stronger effect than the single or sham stimulation modes (pstroke patients.

  20. Type 1 Diabetes Modifies Brain Activation in Young Patients While Performing Visuospatial Working Memory Tasks

    Science.gov (United States)

    Gallardo-Moreno, Geisa B.; González-Garrido, Andrés A.; Gudayol-Ferré, Esteban; Guàrdia-Olmos, Joan

    2015-01-01

    In recent years, increasing attention has been paid to the effects of Type 1 Diabetes (T1D) on cognitive functions. T1D onset usually occurs during childhood, so it is possible that the brain could be affected during neurodevelopment. We selected young patients of normal intelligence with T1D onset during neurodevelopment, no complications from diabetes, and adequate glycemic control. The purpose of this study was to compare the neural BOLD activation pattern in a group of patients with T1D versus healthy control subjects while performing a visuospatial working memory task. Sixteen patients and 16 matched healthy control subjects participated. There was no significant statistical difference in behavioral performance between the groups, but, in accordance with our hypothesis, results showed distinct brain activation patterns. Control subjects presented the expected activations related to the task, whereas the patients had greater activation in the prefrontal inferior cortex, basal ganglia, posterior cerebellum, and substantia nigra. These different patterns could be due to compensation mechanisms that allow them to maintain a behavioral performance similar to that of control subjects. PMID:26266268

  1. 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.

  2. The genetic and environmental structure of verbal and visuospatial memory in young adults and children.

    Science.gov (United States)

    van Leeuwen, Marieke; van den Berg, Stéphanie M; Hoekstra, Rosa A; Boomsma, Dorret I

    2009-11-01

    The extent to which verbal (VM) and visuospatial memory (VSM) tests measure the same or multiple constructs is unclear. Likewise the relationship between VM and VSM across development is not known. These questions are addressed using genetically informative data, studying two age cohorts (young adults and children) of twins and siblings. VM and VSM were measured in the working memory and short-term memory domain. Multivariate genetic analyses revealed that two highly correlated common genetic factors, one for VM and one for VSM, gave the best description of the covariance structure among the measures. Only in children, specific genetic factors were also present. This led to the following conclusions: In children, one genetic factor is responsible for linking VM and VSM. Specific genetic factors create differences between these two domains. During the course of development, the influence of genetic factors unique to each of these domains disappears and the genetic factor develops into two highly correlated factors, which are specific to VM and VSM respectively. At the environmental level, in both age cohorts, environmental factors create differences between these domains.

  3. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding.

    Science.gov (United States)

    Kosovicheva, Anna A; Sheremata, Summer L; Rokem, Ariel; Landau, Ayelet N; Silver, Michael A

    2012-01-01

    Acetylcholine (ACh) reduces the spatial spread of excitatory fMRI responses in early visual cortex and receptive field size of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two phenomena that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Experiment 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: (1) surround grating with the same orientation as the center (parallel), (2) surround orthogonal to the center, or (3) no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS). Cholinergic enhancement decreased thresholds only in the parallel condition, thereby reducing OSSS. In Experiment 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the targets and flanking letters that allowed reliable identification. Cholinergic enhancement with donepezil had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early

  4. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

    Directory of Open Access Journals (Sweden)

    Anna A. Kosovicheva

    2012-09-01

    Full Text Available Acetylcholine (ACh reduces the spatial spread of excitatory fMRI responses in early visual cortex and the receptive field sizes of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two tasks that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Exp. 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: 1 surround grating with the same orientation as the center (parallel, 2 surround orthogonal to the center, or 3 no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS. Cholinergic enhancement reduced thresholds only in the parallel condition, thereby reducing OSSS. In Exp. 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the target and flanking letters that allowed reliable identification. Cholinergic enhancement had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early visual cortical

  5. Neural mechanisms of surround attenuation and distractor competition in visual search.

    Science.gov (United States)

    Boehler, Carsten N; Tsotsos, John K; Schoenfeld, Mircea A; Heinze, Hans-Jochen; Hopf, Jens-Max

    2011-04-06

    Visual attention biases relevant processing in the visual system by amplifying relevant or attenuating irrelevant sensory input. A potential signature of the latter operation, referred to as surround attenuation, has recently been identified in the electromagnetic brain response of human observers performing visual search. It was found that a zone of attenuated cortical excitability surrounds the target when the search required increased spatial resolution for item discrimination. Here we address the obvious hypothesis that surround attenuation serves distractor suppression in the vicinity of the target where interference from irrelevant search items is maximal. To test this hypothesis, surround attenuation was assessed under conditions when the target was presented in isolation versus when it was surrounded by distractors. Surprisingly, substantial and indistinguishable surround attenuation was seen under both conditions, indicating that it reflects an attentional operation independent of the presence of distractors. Adding distractors in the target's surround, however, increased the amplitude of the N2pc--an evoked response known to index distractor competition in visual search. Moreover, adding distractors led to a topographical change of source activity underlying the N2pc toward earlier extrastriate areas. In contrast, the topography of reduced source activity due to surround attenuation remained unaltered with and without distractors in the target's surround. We conclude that surround attenuation is not a direct consequence of the attenuation of distractors in visual search and that it dissociates from attentional operations reflected by the N2pc. A theoretical framework is proposed that links both operations in a common model of top-down attentional selection in visual cortex.

  6. Triggered star formation surrounding Wolf-Rayet star HD 211853

    CERN Document Server

    Liu, Tie; Zhang, Huawei; Qin, Sheng-Li

    2012-01-01

    The environment surrounding Wolf-Rayet star HD 211853 is studied in molecular emission, infrared emission, as well as radio and HI emission. The molecular ring consists of well-separated cores, which have a volume density of 10$^{3}$ cm$^{-3}$ and kinematic temperature $\\sim$20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From SED modeling towards the young stellar objects (YSOs), sequential star formation is revealed on a large scale in space spreading from the Wolf-Rayet star to the molecular ring. A small scale sequential star formation is revealed towards core A, which harbors a very young star cluster. Triggered star formations is thus suggested. The presence of PDR, the fragmentation of the molecular ring, the collapse of the cores, the large scale sequential star formation indicate the "Collect and Collapse" process functions in this region. The star forming activities in core A seem to be affected by the "Radiation-Driven Implosion" (...

  7. An analysis of amino acid sequences surrounding archaeal glycoprotein sequons.

    Science.gov (United States)

    Abu-Qarn, Mehtap; Eichler, Jerry

    2007-05-01

    Despite having provided the first example of a prokaryal glycoprotein, little is known of the rules governing the N-glycosylation process in Archaea. As in Eukarya and Bacteria, archaeal N-glycosylation takes place at the Asn residues of Asn-X-Ser/Thr sequons. Since not all sequons are utilized, it is clear that other factors, including the context in which a sequon exists, affect glycosylation efficiency. As yet, the contribution to N-glycosylation made by sequon-bordering residues and other related factors in Archaea remains unaddressed. In the following, the surroundings of Asn residues confirmed by experiment as modified were analyzed in an attempt to define sequence rules and requirements for archaeal N-glycosylation.

  8. An analysis of amino acid sequences surrounding archaeal glycoprotein sequons

    Directory of Open Access Journals (Sweden)

    Mehtap Abu-Qarn

    2006-01-01

    Full Text Available Despite having provided the first example of a prokaryal glycoprotein, little is known of the rules governing the N-glycosylation process in Archaea. As in Eukarya and Bacteria, archaeal N-glycosylation takes place at the Asn residues of Asn-X-Ser/Thr sequons. Since not all sequons are utilized, it is clear that other factors, including the context in which a sequon exists, affect glycosylation efficiency. As yet, the contribution to N-glycosylation made by sequon-bordering residues and other related factors in Archaea remains unaddressed. In the following, the surroundings of Asn residues confirmed by experiment as modified were analyzed in an attempt to define sequence rules and requirements for archaeal N-glycosylation.

  9. Comparison of Socioeconomic Factors between Surrounding and Non-Surrounding Areas of the Qinghai–Tibet Railway before and after Its Construction

    Directory of Open Access Journals (Sweden)

    Shicheng Li

    2016-08-01

    Full Text Available As the world’s highest railway, and the longest highland railway, the Qinghai–Tibet Railway (QTR has been paid considerable attention by researchers. However, most attention has been paid to the ecological and environmental issues affecting it, and sustainable ecological, social, and economic development-related studies of the QTR are rare. In this study, by analyzing the passenger traffic, freight traffic, passenger-kilometers, and freight-kilometers of the QTR for the period 1982–2013 and the transport structure of the Tibetan Plateau (TP for 1990–2013, the evolutionary process of the transport system in the TP following the construction of the QTR has been revealed. Subsequently, by comparing Gross Domestic Product (GDP, population, industrial structure, and urbanization level at the county and 1 km scales between surrounding and non-surrounding areas of the QTR, the differences in socioeconomic performance before and after its construction were detected. The results show that (1 in the TP, the highway-dominated transport system will break up and an integrated and sustainable transport system will form; (2 at the county scale, the annual growth rates of GDP of counties surrounding the QTR were greater than those of non-surrounding counties for the period 2000–2010. At the 1 km scale, following the opening of the completed line, the GDP of surrounding areas had a greater growth rate than before; (3 analysis at the county and 1 km scales indicated that population was not aggregated into the surrounding areas of the QTR in the period 2000–2010; (4 in terms of industrial structure, the proportion of primary industry decreased continuously, while the proportion of secondary and tertiary industries increased overall in the period 1984–2012. The QTR had no obvious impact on changes in the urbanization level of its surrounding areas.

  10. Numerical Analysis of Advanced Displacement in Construction Progress of Tunnel Excavation with Weak Surrounding Rock

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2013-07-01

    Full Text Available Analysis of advanced displacement in construction progress of tunnel excavation with weak surrounding rock is carried out by numerical method and comparison of model test result. In allusion to the problems of regional landslides and extruded large-deformation seriously impacting the stability of rock mass in construction process of large-section tunnel with weak surrounding rock, the elastic-plastic numerical simulation relying on Liangshui tunnel of Lan-Yu railroad is conducted on mechanical behaviors and deformation steric effect of tunnel construction and the calculation results are compared with the modeling data. The research results show that: the steric effect of excavation face is the dominant factor in the incidence of working face and the stress of surrounding rocks gradually releases from excavation face; the range of 0.5~1 times the cave diameter around rock mass in front of working face is the disturbance range and the key area of stabilization and reinforcement for wake surrounding rock. According to the analysis and construction practice, the supporting structure of large-section tunnel with weak surrounding rock should be established as soon as possible to control the displacement change of surrounding rock in the range of load-bearing ring, reduce disturbance and improve the self-bearing capability of surrounding rock. Because of the distinct excavation steric effect of weak surrounding rock, the secondary lining structure must be established in time to bear the later pressure and restrict the large displacement of surrounding rock. The research results can provide reliable basis for engineering stability control of analogous tunnels.

  11. Dopamine transporters in striatum correlate with deactivation in the default mode network during visuospatial attention.

    Directory of Open Access Journals (Sweden)

    Dardo Tomasi

    Full Text Available BACKGROUND: Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN. Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation in the DMN during an attention task. METHODOLOGY/PRINCIPAL FINDINGS: For this purpose we assessed the relationship between DAT in striatum (measured with positron emission tomography and [(11C]cocaine used as DAT radiotracer and brain activation and deactivation during a parametric visual attention task (measured with blood oxygenation level dependent functional magnetic resonance imaging in healthy controls. We show that DAT availability in caudate and putamen had a negative correlation with deactivation in ventral parietal regions of the DMN (precuneus, BA 7 and a positive correlation with deactivation in a small region in the ventral anterior cingulate gyrus (BA 24/32. With increasing attentional load, DAT in caudate showed a negative correlation with load-related deactivation increases in precuneus. CONCLUSIONS/SIGNIFICANCE: These findings provide evidence that dopamine transporters modulate neural activity in the DMN and anterior cingulate gyrus during visuospatial attention. Our findings suggest that dopamine modulates attention in part by regulating neuronal activity in posterior parietal cortex including precuneus (region involved in alertness and cingulate gyrus (region deactivated in proportion to emotional interference. These findings suggest that the beneficial effects of stimulant medications (increase dopamine by blocking DAT in inattention reflect in part their ability to facilitate the deactivation of the DMN.

  12. Sex-Related Differences in the Effects of Sleep Habits on Verbal and Visuospatial Working Memory.

    Science.gov (United States)

    Nakagawa, Seishu; Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Sekiguchi, Atsushi; Kotozaki, Yuka; Miyauchi, Carlos M; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2016-01-01

    Poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF). Declarative working memory can be subdivided into verbal working memory (VWM) and visuospatial working memory (VSWM). We hypothesized that sleep habits would have different effects on VWM and VSWM. To our knowledge, our study is the first to investigate differences between VWM and VSWM related to daytime nap duration, nap frequency, and DCRF. Furthermore, we tested the hypothesis that the effects of duration and frequency of daytime naps and DCRF on VWM and VSWM differed according to sex. We assessed 779 healthy right-handed individuals (434 males and 345 females; mean age: 20.7 ± 1.8 years) using a digit span forward and backward VWM task, a forward and backward VSWM task, and sleep habits scales. A correlation analysis was used to test the relationships between VWM capacity (VWMC) and VSWM capacity (VSWMC) scores and sleep duration, nap duration, nap frequency, and DCRF. Furthermore, multiple regression analyses were conducted to identify factors associated with VWMC and VSWMC scores and to identify sex-related differences. We found significant positive correlations between VSWMC and nap duration and DCRF, and between VWMC and sleep duration in all subjects. Furthermore, we found that working memory capacity (WMC) was positively correlated with nap duration in males and with sleep duration in females, and DCRF was positively correlated with VSWMC in females. Our finding of sex-related differences in the effects of sleep habits on WMC has not been reported previously. The associations between WMC and sleep habits differed according to sex because of differences in the underlying neural correlates of VWM and VSWM, and effectiveness of the sleep habits in males and females.

  13. Sex-related differences in the effects of sleep habits on verbal and visuospatial working memory

    Directory of Open Access Journals (Sweden)

    Seishu Nakagawa

    2016-07-01

    Full Text Available Sleep facilitates memory consolidation. Consequently, poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF. Declarative working memory can be subdivided into verbal working memory (VWM and visuospatial working memory (VSWM. We hypothesized that sleep habits would have different effects on VWM and VSWM. To our knowledge, our study is the first to investigate differences between VWM and VSWM related to daytime nap duration, nap frequency, and DCRF. Furthermore, we tested the hypothesis that the effects of duration and frequency of daytime naps and DCRF on VWM and VSWM differed according to sex. We assessed 779 healthy right-handed individuals (434 males and 345 females; mean age: 20.7 ± 1.8 years using a digit span forward and backward VWM task, a forward and backward VSWM task, and sleep habits scales. A correlation analysis was used to test the relationships between VWM capacity (VWMC and VSWM capacity (VSWMC scores and sleep duration, nap duration, nap frequency, and DCRF. Furthermore, multiple regression analyses were conducted to identify factors associated with VWMC and VSWMC scores and to identify sex-related differences. We found significant positive correlations between VSWMC and nap duration and DCRF, and between VWMC and sleep duration in all subjects. Furthermore, we found that working memory capacity (WMC was positively correlated with nap duration in males and with sleep duration in females, and DCRF was positively correlated with VSWMC in females. Our finding of sex-related differences in the effects of sleep habits on WMC has not been reported previously. The associations between WMC and sleep habits differed according to sex because of differences in the underlying neural correlates of VWM and VSWM, and effectiveness of the sleep habits

  14. Dopamine Transporters in Striatum Correlated with Deactivation in the Default Mode Network during Visuospatial Attention

    Energy Technology Data Exchange (ETDEWEB)

    Tomasi, D.; Fowler, J.; Tomasi, D.; Volkow, N.D.; Wang, R.L.; Telang, F.; Wang, Chang, L.; Ernst, T.; /Fowler, J.S.

    2009-06-01

    Dopamine and dopamine transporters (DAT, which regulate extracellular dopamine in the brain) are implicated in the modulation of attention but their specific roles are not well understood. Here we hypothesized that dopamine modulates attention by facilitation of brain deactivation in the default mode network (DMN). Thus, higher striatal DAT levels, which would result in an enhanced clearance of dopamine and hence weaker dopamine signals, would be associated to lower deactivation in the DMN during an attention task. For this purpose we assessed the relationship between DAT in striatum (measured with positron emission tomography and [{sup 11}C]cocaine used as DAT radiotracer) and brain activation and deactivation during a parametric visual attention task (measured with blood oxygenation level dependent functional magnetic resonance imaging) in healthy controls. We show that DAT availability in caudate and putamen had a negative correlation with deactivation in ventral parietal regions of the DMN (precuneus, BA 7) and a positive correlation with deactivation in a small region in the ventral anterior cingulate gyrus (BA 24/32). With increasing attentional load, DAT in caudate showed a negative correlation with load-related deactivation increases in precuneus. These findings provide evidence that dopamine transporters modulate neural activity in the DMN and anterior cingulate gyrus during visuospatial attention. Our findings suggest that dopamine modulates attention in part by regulating neuronal activity in posterior parietal cortex including precuneus (region involved in alertness) and cingulate gyrus (region deactivated in proportion to emotional interference). These findings suggest that the beneficial effects of stimulant medications (increase dopamine by blocking DAT) in inattention reflect in part their ability to facilitate the deactivation of the DMN.

  15. Fast detection of covert visuospatial attention using hybrid N2pc and SSVEP features

    Science.gov (United States)

    Xu, Minpeng; Wang, Yijun; Nakanishi, Masaki; Wang, Yu-Te; Qi, Hongzhi; Jung, Tzyy-Ping; Ming, Dong

    2016-12-01

    Objective. Detecting the shift of covert visuospatial attention (CVSA) is vital for gaze-independent brain-computer interfaces (BCIs), which might be the only communication approach for severely disabled patients who cannot move their eyes. Although previous studies had demonstrated that it is feasible to use CVSA-related electroencephalography (EEG) features to control a BCI system, the communication speed remains very low. This study aims to improve the speed and accuracy of CVSA detection by fusing EEG features of N2pc and steady-state visual evoked potential (SSVEP). Approach. A new paradigm was designed to code the left and right CVSA with the N2pc and SSVEP features, which were then decoded by a classification strategy based on canonical correlation analysis. Eleven subjects were recruited to perform an offline experiment in this study. Temporal waves, amplitudes, and topographies for brain responses related to N2pc and SSVEP were analyzed. The classification accuracy derived from the hybrid EEG features (SSVEP and N2pc) was compared with those using the single EEG features (SSVEP or N2pc). Main results. The N2pc could be significantly enhanced under certain conditions of SSVEP modulations. The hybrid EEG features achieved significantly higher accuracy than the single features. It obtained an average accuracy of 72.9% by using a data length of 400 ms after the attention shift. Moreover, the average accuracy reached ˜80% (peak values above 90%) when using 2 s long data. Significance. The results indicate that the combination of N2pc and SSVEP is effective for fast detection of CVSA. The proposed method could be a promising approach for implementing a gaze-independent BCI.

  16. Issues surrounding health claims for barley.

    Science.gov (United States)

    Ames, Nancy P; Rhymer, Camille R

    2008-06-01

    Government-approved health claims support dietary intervention as a safe and practical approach to improving consumer health and provide industry with regulatory guidelines for food product labels. Claims already allowed in the United States, United Kingdom, Sweden, and The Netherlands for reducing cholesterol through consumption of oat or barley soluble fiber provide a basis for review, but each country may have different criteria for assessing clinical evidence for a physiological effect. For example, the FDA-approved barley health claim was based on a petition that included 39 animal model studies and 11 human clinical trials. Since then, more studies have been published, but with few exceptions, clinical data continue to demonstrate that the consumption of barley products is effective for lowering total and LDL cholesterol. More research is needed to fully understand the mechanism of cholesterol reduction and the role of beta-glucan molecular weight, viscosity, and solubility. In an assessment of the physiological efficacy of a dietary intervention, consideration should also be given to the potential impact of physical and thermal food-processing treatments and genotypic variation in the barley source. New barley cultivars have been generated specifically for food use, possessing increased beta-glucan, desirable starch composition profiles, and improved milling/processing traits. These advances in barley production, coupled with the establishment of a government-regulated health claim for barley beta-glucan, will stimulate new processing opportunities for barley foods and provide consumers with reliable, healthy food choices.

  17. Endogenous testosterone levels and visuospatial ability%内源性睾酮与视空间能力

    Institute of Scientific and Technical Information of China (English)

    盖琼; 孙月吉; 孙文恒; 王凡; 沙莉; 郑亚; 姜月; 徐国庆; 沈慧娟

    2016-01-01

    本文探讨内源性睾酮水平对于视空间能力表现的影响。2014年以“视空间能力,睾酮,性别差异”为关键词,通过Pubmed和Ovid等数据库检索国内外相关论文46篇进行整理综述。最终纳入35篇相关论文,男性视空间能力任务表现优于女性,睾酮水平在男性视空间能力优势中起到了重要作用。其主要影响包括两方面:组织作用和激活作用,其中睾酮的激活作用因具有可逆性而受到更加广泛的关注。到目前为止,睾酮对视空间能力影响的研究多数为行为学水平,采用的空间任务主要包括心理旋转任务、虚拟导航、现实场景任务等,一种非线性相关关系已经成为争论的焦点。最新研究指出今后应深入探讨视空间能力的相关神经机制,采用ERP及MRI等相关实验技术,进一步评估内源性睾酮水平对相关神经基础的影响。%To describe the effects of endogenous testosterone levels on the visuospatial ability.The"visuospatial ability,testosterone"were included as the key words,retrieving 46 papers in the database.35 relevant papers have been reviewed in the paper,as the results,we have found that the visuospatial ability of male was better than female.The performances of the visuospatial tasks in males were associated with the lev-els of endogenous testosterone,and the effects comprised two aspects:the organizational function and activa-tional function of the testosterone.The latter have received more attention from researchers.Until now,most studies of activational effects of testosterone on visuospatial ability remained on the level of behavioral re-search.The mental rotation task,navigation task and virtual reality scenes tasks were implied in these stud-ies.A nonlinear relationship has aroused a great controversy.Latest research suggests that further investiga-tion of the neural mechanisms related to visual-spatial ability is needed,using ERP and MRI techniques

  18. Stroke Is Predicted by Low Visuospatial in Relation to Other Intellectual Abilities and Coronary Heart Disease by Low General Intelligence

    Science.gov (United States)

    Kajantie, Eero; Räikkönen, Katri; Henriksson, Markus; Leskinen, Jukka T.; Forsén, Tom; Heinonen, Kati; Pesonen, Anu-Katriina; Osmond, Clive; Barker, David J. P.; Eriksson, Johan G.

    2012-01-01

    Background Low intellectual ability is associated with an increased risk of coronary heart disease and stroke. Most studies have used a general intelligence score. We studied whether three different subscores of intellectual ability predict these disorders. Methods We studied 2,786 men, born between 1934 and 1944 in Helsinki, Finland, who as conscripts at age 20 underwent an intellectual ability test comprising verbal, visuospatial (analogous to Raven's progressive matrices) and arithmetic reasoning subtests. We ascertained the later occurrence of coronary heart disease and stroke from validated national hospital discharge and death registers. Results 281 men (10.1%) had experienced a coronary heart disease event and 131 (4.7%) a stroke event. Coronary heart disease was predicted by low scores in all subtests, hazard ratios for each standard deviation (SD) lower score ranging from 1.21 to 1.30 (confidence intervals 1.08 to 1.46). Stroke was predicted by a low visuospatial reasoning score, the corresponding hazard ratio being 1.23 (95% confidence interval 1.04 to 1.46), adjusted for year and age at testing. Adjusted in addition for the two other scores, the hazard ratio was 1.40 (1.10 to 1.79). This hazard ratio was little affected by adjustment for socioeconomic status in childhood and adult life, whereas the same adjustments attenuated the associations between intellectual ability and coronary heart disease. The associations with stroke were also unchanged when adjusted for systolic blood pressure at 20 years and reimbursement for adult antihypertensive medication. Conclusions Stroke is predicted by low visuospatial reasoning scores in relation to scores in the two other subtests. This association may be mediated by common underlying causes such as impaired brain development, rather than by mechanisms associated with risk factors shared by stroke and coronary heart disease, such as socio-economic status, hypertension and atherosclerosis. PMID:23144789

  19. Stroke is predicted by low visuospatial in relation to other intellectual abilities and coronary heart disease by low general intelligence.

    Directory of Open Access Journals (Sweden)

    Eero Kajantie

    Full Text Available BACKGROUND: Low intellectual ability is associated with an increased risk of coronary heart disease and stroke. Most studies have used a general intelligence score. We studied whether three different subscores of intellectual ability predict these disorders. METHODS: We studied 2,786 men, born between 1934 and 1944 in Helsinki, Finland, who as conscripts at age 20 underwent an intellectual ability test comprising verbal, visuospatial (analogous to Raven's progressive matrices and arithmetic reasoning subtests. We ascertained the later occurrence of coronary heart disease and stroke from validated national hospital discharge and death registers. RESULTS: 281 men (10.1% had experienced a coronary heart disease event and 131 (4.7% a stroke event. Coronary heart disease was predicted by low scores in all subtests, hazard ratios for each standard deviation (SD lower score ranging from 1.21 to 1.30 (confidence intervals 1.08 to 1.46. Stroke was predicted by a low visuospatial reasoning score, the corresponding hazard ratio being 1.23 (95% confidence interval 1.04 to 1.46, adjusted for year and age at testing. Adjusted in addition for the two other scores, the hazard ratio was 1.40 (1.10 to 1.79. This hazard ratio was little affected by adjustment for socioeconomic status in childhood and adult life, whereas the same adjustments attenuated the associations between intellectual ability and coronary heart disease. The associations with stroke were also unchanged when adjusted for systolic blood pressure at 20 years and reimbursement for adult antihypertensive medication. CONCLUSIONS: Stroke is predicted by low visuospatial reasoning scores in relation to scores in the two other subtests. This association may be mediated by common underlying causes such as impaired brain development, rather than by mechanisms associated with risk factors shared by stroke and coronary heart disease, such as socio-economic status, hypertension and atherosclerosis.

  20. Investigating the impact of innate dexterity skills and visuospatial aptitude on the performance of baseline laparoscopic skills in veterinary students.

    Science.gov (United States)

    MacCormick, Mathew R A; Kilkenny, Jessica J; Walker, Meagan; Zur Linden, Alex; Singh, Ameet

    2017-09-11

    To determine if manual dexterity and visuospatial skills can be used to predict baseline laparoscopic surgery skills in veterinary students. Pilot study. Veterinary students (n = 45) from years 1-4 volunteered for this study. An hour-long electronic questionnaire was completed by participants. The first section was used to collect demographics and information about prior nonsurgical experiences. The second section included 3 tests of visuospatial skills, including the Purdue Visualization of Rotations Test, Mental Rotations Test, and Raven's Advanced Progressive Matrices Test. Multiple tests were administered to assess innate dexterity, including the grooved pegboard test, indirect and direct zigzag tracking tests, and the 3Dconnexion proficiency test. Each dexterity test was performed once with the left hand and once with the right hand. The order of task performance was randomized. Basic laparoscopic skills were assessed using the validated fundamentals of laparoscopic surgery (FLS) peg transfer task. There was an association between left-handed grooved pegboard scores (95% CI -10046.36 to -1636.53, P-value = .008) and left-handed indirect zigzag tracking task (95% CI -35.78 to -8.20, P-value = .003) with FLS peg transfer scores. Individuals who reported playing videogames achieved higher scores on the FLS peg transfer task than those without videogame experience (95% CI 583.59 to 3509.97, P-value = .007). The results of this study suggest that dexterity was a better predictor of baseline laparoscopic skills than visuospatial skills in veterinary students. © 2017 The American College of Veterinary Surgeons.

  1. Treatment of visuospatial neglect with biparietal tDCS and cognitive training: a single-case study.

    Science.gov (United States)

    Brem, Anna-Katharine; Unterburger, Evelyn; Speight, Irving; Jäncke, Lutz

    2014-01-01

    Symptoms of visuospatial neglect occur frequently after unilateral brain damage. Neglect hampers rehabilitation progress and is associated with reduced quality of life. However, existing treatment methods show limited efficacy. Transcranial direct current stimulation (tDCS) is a neuromodulatory technique, which can be used to increase or decrease brain excitability. Its combination with conventional neglect therapy may enhance treatment efficacy. A 72-year-old male with a subacute ischemic stroke of the right posterior cerebral artery suffering from visuospatial neglect, hemianopia, and hemiparesis was treated with biparietal tDCS and cognitive neglect therapy in a double-blind, sham-controlled single-case study. Four weeks of daily treatment sessions (5 days per week, 30 min) were started 26 days post-stroke. During week 1 and 4 the patient received conventional neglect therapy, during week 2, conventional neglect therapy was combined once with sham and once with real biparietal tDCS. Week 3 consisted of daily sessions of real biparietal tDCS (1 mA, 20 min) combined with neglect therapy. Outcome measures were assessed before, immediately after, as well as 1 week and 3 months after the end of treatment. They included subtests of the Test for Attentional Performance (TAP): covert attention (main outcome), alertness, visual field; the Neglect-Test (NET): line bisection, cancelation, copying; and activities of daily living (ADL). After real stimulation, covert attention allocation toward left-sided invalid stimuli was significantly improved, and line bisection and copying improved qualitatively as compared to sham stimulation. ADL were only improved at the 3-month follow-up. This single-case study demonstrates for the first time that combined application of tDCS and cognitive training may enhance training-induced improvements in measures of visuospatial neglect and is applicable in a clinical context.

  2. Treatment of visuospatial neglect with biparietal tDCS and cognitive training: a single-case study

    Directory of Open Access Journals (Sweden)

    Anna-Katharine eBrem

    2014-09-01

    Full Text Available Symptoms of visuospatial neglect occur frequently after unilateral brain damage. Neglect hampers rehabilitation progress and is associated with reduced quality of life. However, existing treatment methods show limited efficacy. Transcranial direct current stimulation (tDCS is a neuromodulatory technique, which can be used to increase or decrease brain excitability. Its combination with conventional neglect therapy may enhance treatment efficacy.A 72-year-old male with a subacute ischaemic stroke of the right posterior cerebral artery suffering from visuospatial neglect, hemianopia, and hemiparesis was treated with biparietal tDCS and cognitive neglect therapy in a double-blind, sham-controlled single-case study. Four weeks of daily treatment sessions (5 days per week, 30 min were started 26 days post-stroke. During week 1 and 4 the patient received conventional neglect therapy, during week 2, conventional neglect therapy was combined once with sham and once with real biparietal tDCS. Week 3 consisted of daily sessions of real biparietal tDCS (1 mA, 20 min combined with neglect therapy. Outcome measures were assessed before, immediately after, as well as 1 week and 3 months after the end of treatment. They included subtests of the Test for Attentional Performance (TAP: covert attention (main outcome, alertness, visual field; the Neglect-Test (NET: line bisection, cancellation, copying; and activities of daily living (ADL. After real stimulation, covert attention allocation towards left-sided invalid stimuli was significantly improved, and line bisection and copying improved qualitatively as compared to sham stimulation. ADL were only improved at the 3-month follow-up. This single-case study demonstrates for the first time that combined application of tDCS and cognitive training may enhance training-induced improvements in measures of visuospatial neglect and is applicable in a clinical context.

  3. Persistence of Gender Related-Effects on Visuo-Spatial and Verbal Working Memory in Right Brain-Damaged Patients

    OpenAIRE

    Piccardi, Laura; Matano, Alessandro; D’Antuono, Giovanni; Marin, Dario; Ciurli, Paola; Incoccia, Chiara; Verde, Paola; Guariglia, Paola

    2016-01-01

    The aim of the present study was to verify if gender differences in verbal and visuo-spatial working memory would persist following right cerebral lesions. To pursue our aim we investigated a large sample (n. 346) of right brain-damaged patients and healthy participants (n. 272) for the presence of gender effects in performing Corsi and Digit Test. We also assessed a subgroup of patients (n. 109) for the nature (active vs. passive) of working memory tasks. We tested working memory (WM) admini...

  4. Dust observations at orbital altitudes surrounding Mars.

    Science.gov (United States)

    Andersson, L; Weber, T D; Malaspina, D; Crary, F; Ergun, R E; Delory, G T; Fowler, C M; Morooka, M W; McEnulty, T; Eriksson, A I; Andrews, D J; Horanyi, M; Collette, A; Yelle, R; Jakosky, B M

    2015-11-01

    Dust is common close to the martian surface, but no known process can lift appreciable concentrations of particles to altitudes above ~150 kilometers. We present observations of dust at altitudes ranging from 150 to above 1000 kilometers by the Langmuir Probe and Wave instrument on the Mars Atmosphere and Volatile Evolution spacecraft. Based on its distribution, we interpret this dust to be interplanetary in origin. A comparison with laboratory measurements indicates that the dust grain size ranges from 1 to 12 micrometers, assuming a typical grain velocity of ~18 kilometers per second. These direct observations of dust entering the martian atmosphere improve our understanding of the sources, sinks, and transport of interplanetary dust throughout the inner solar system and the associated impacts on Mars's atmosphere.

  5. Stress and deformation analysis on deep surrounding rock at different time stages and its application

    Institute of Scientific and Technical Information of China (English)

    Li Ming; Mao Xianbiao; Yu Yuanlin; Li Kai; Ma Chao; Peng Yan

    2012-01-01

    Based on the characteristics of the deep circular tunnel,the surrounding rock was divided into three regions:the cracked region,the plastic region and the viscoelastic region.The process of rock stress deformation and change was divided into three stages after the roadway excavation.By using the elastic-plastic mechanics theory,the analytical solutions of the surrounding stress and displacement at different stages and the radii of cracked and plastic regions were formulated.We additionally explained the surrounding rock stress and displacement which appeared in practical project.Simultaneously,based on the problem which emerged from a mine in Xuzhou during the excavating process of rock roadway's transport,we got the theoretical solutions for the stress and displacement in the process of rock roadway's excavation and considered that the broken area of rock roadway was largely loosing circle.The results indicate that according to the rheological characteristics of surrounding rock,in the primeval excavation of rock roadway,we should increase the length of anchor bolt and cooperate it with anchor nets cable-U steel supporting frame.In addition,when the deformation rate of the surrounding rock is descending after the 15 days' excavation,we should use the "three anchor" supporting method (anchor bolt spray,anchor note and anchor rope) and set aside about 20 cm as the reserved deformation layer.

  6. THE CLASSIFICATION OF THE SURROUNDINGS OF COAL MINING ROADWAYS

    Institute of Scientific and Technical Information of China (English)

    邹喜正; 侯朝炯; 李华祥

    1996-01-01

    This introduces the calculation of opaper the deformationg .the Surroundings of coaowaysand the divisi of surroundings into 5 levels by means or !fuzzy integral assess mairrx, wnlcnserves-asthe scientific basis for selecting supporting pattern of roadways and determining the, pa-rameters of support.

  7. Right-sided representational neglect after left brain damage in a case without visuospatial working memory deficits.

    Science.gov (United States)

    van Dijck, Jean-Philippe; Gevers, Wim; Lafosse, Christophe; Fias, Wim

    2013-10-01

    Brain damaged patients suffering from representational neglect (RN) fail to report, orient to, or verbally describe contra-lesional elements of imagined environments or objects. So far this disorder has only been reported after right brain damage, leading to the idea that only the right hemisphere is involved in this deficit. A widely accepted account attributes RN to a lateralized impairment in the visuospatial component of working memory. So far, however, this hypothesis has not been tested in detail. In the present paper, we describe, for the first time, the case of a left brain damaged patient suffering from right-sided RN while imagining both known and new environments and objects. An in-depth evaluation of her visuospatial working memory abilities, with special focus on the presence of a lateralized deficit, did not reveal any abnormality. In sharp contrast, her ability to memorize visual information was severely compromised. The implications of these results are discussed in the light of recent insights in the neglect syndrome.

  8. Feedback associated with expectation for larger-reward improves visuospatial working memory performances in children with ADHD

    Directory of Open Access Journals (Sweden)

    Rubi Hammer

    2015-08-01

    Full Text Available We tested the interactive effect of feedback and reward on visuospatial working memory in children with ADHD. Seventeen boys with ADHD and 17 Normal Control (NC boys underwent functional magnetic resonance imaging (fMRI while performing four visuospatial 2-back tasks that required monitoring the spatial location of letters presented on a display. Tasks varied in reward size (large; small and feedback availability (no-feedback; feedback. While the performance of NC boys was high in all conditions, boys with ADHD exhibited higher performance (similar to those of NC boys only when they received feedback associated with large-reward. Performance pattern in both groups was mirrored by neural activity in an executive function neural network comprised of few distinct frontal brain regions. Specifically, neural activity in the left and right middle frontal gyri of boys with ADHD became normal-like only when feedback was available, mainly when feedback was associated with large-reward. When feedback was associated with small-reward, or when large-reward was expected but feedback was not available, boys with ADHD exhibited altered neural activity in the medial orbitofrontal cortex and anterior insula. This suggests that contextual support normalizes activity in executive brain regions in children with ADHD, which results in improved working memory.

  9. Atypical cortical connectivity and visuospatial cognitive impairments are related in children with chromosome 22q11.2 deletion syndrome

    Directory of Open Access Journals (Sweden)

    Gee James C

    2008-06-01

    Full Text Available Abstract Background Chromosome 22q11.2 deletion syndrome is one of the most common genetic causes of cognitive impairment and developmental disability yet little is known about the neural bases of those challenges. Here we expand upon our previous neurocognitive studies by specifically investigating the hypothesis that changes in neural connectivity relate to cognitive impairment in children with the disorder. Methods Whole brain analyses of multiple measures computed from diffusion tensor image data acquired from the brains of children with the disorder and typically developing controls. We also correlated diffusion tensor data with performance on a visuospatial cognitive task that taps spatial attention. Results Analyses revealed four common clusters, in the parietal and frontal lobes, that showed complementary patterns of connectivity in children with the deletion and typical controls. We interpreted these results as indicating differences in connective complexity to adjoining cortical regions that are critical to the cognitive functions in which affected children show impairments. Strong, and similarly opposing patterns of correlations between diffusion values in those clusters and spatial attention performance measures considerably strengthened that interpretation. Conclusion Our results suggest that atypical development of connective patterns in the brains of children with chromosome 22q11.2 deletion syndrome indicate a neuropathology that is related to the visuospatial cognitive impairments that are commonly found in affected individuals.

  10. Translating working memory into action: behavioral and neural evidence for using motor representations in encoding visuo-spatial sequences.

    Science.gov (United States)

    Langner, Robert; Sternkopf, Melanie A; Kellermann, Tanja S; Grefkes, Christian; Kurth, Florian; Schneider, Frank; Zilles, Karl; Eickhoff, Simon B

    2014-07-01

    The neurobiological organization of action-oriented working memory is not well understood. To elucidate the neural correlates of translating visuo-spatial stimulus sequences into delayed (memory-guided) sequential actions, we measured brain activity using functional magnetic resonance imaging while participants encoded sequences of four to seven dots appearing on fingers of a left or right schematic hand. After variable delays, sequences were to be reproduced with the corresponding fingers. Recall became less accurate with longer sequences and was initiated faster after long delays. Across both hands, encoding and recall activated bilateral prefrontal, premotor, superior and inferior parietal regions as well as the basal ganglia, whereas hand-specific activity was found (albeit to a lesser degree during encoding) in contralateral premotor, sensorimotor, and superior parietal cortex. Activation differences after long versus short delays were restricted to motor-related regions, indicating that rehearsal during long delays might have facilitated the conversion of the memorandum into concrete motor programs at recall. Furthermore, basal ganglia activity during encoding selectively predicted correct recall. Taken together, the results suggest that to-be-reproduced visuo-spatial sequences are encoded as prospective action representations (motor intentions), possibly in addition to retrospective sensory codes. Overall, our study supports and extends multi-component models of working memory, highlighting the notion that sensory input can be coded in multiple ways depending on what the memorandum is to be used for.

  11. Executive Functioning and Visuospatial Abilities in Bulimia Nervosa with or without a Previous History of Anorexia Nervosa.

    Science.gov (United States)

    Degortes, Daniela; Tenconi, Elena; Santonastaso, Paolo; Favaro, Angela

    2016-03-01

    The aim of the present study was to investigate executive functioning and visuospatial abilities in patients with bulimia nervosa (BN), with a particular interest in exploring the impact of a previous diagnosis of anorexia nervosa (AN). Several neuropsychological tasks were administered to 89 BN patients (52 with a previous history of AN and 37 without previous AN) and 160 healthy women. A poorer performance on set-shifting measures (Wisconsin Card Sorting Test) was found only in BN patients with a previous history of AN. Decision-making abilities (Iowa Gambling Task) were significantly impaired in the whole sample of BN patients, but difficulties were more pronounced in the subgroup with previous AN. Finally, we did not find any differences in response inhibition and visuospatial abilities between the two samples of BN patients and healthy women. Our findings support the idea that cognitive abilities in patients with BN are more impaired in the presence of a prior history of AN. The clinical and treatment implications of our findings should be explored in future studies. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

  12. Assessing Visuospatial Skills in Parkinson's: Comparison of Neuropsychological Assessment Battery Visual Discrimination to the Judgment of Line Orientation.

    Science.gov (United States)

    Renfroe, Jenna B; Turner, Travis H; Hinson, Vanessa K

    2017-02-01

    Judgment of Line Orientation (JOLO) test is widely used in assessing visuospatial deficits in Parkinson's disease (PD). The neuropsychological assessment battery (NAB) offers the Visual Discrimination test, with age and education correction, parallel forms, and co-normed standardization sample for comparisons within and between domains. However, NAB Visual Discrimination has not been validated in PD, and may not measure the same construct as JOLO. A heterogeneous sample of 47 PD patients completed the JOLO and NAB Visual Discrimination within a broader neuropsychological evaluation. Pearson correlations assessed relationships between JOLO and NAB Visual Discrimination performances. Raw and demographically corrected scores from JOLO and Visual Discrimination were only weakly correlated. NAB Visual Discrimination subtest was moderately correlated with overall cognitive functioning, whereas the JOLO was not. Despite apparent virtues, results do not support NAB Visual Discrimination as an alternative to JOLO in assessing visuospatial functioning in PD. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Tomography images of the Alpine roots and surrounding upper mantle

    Science.gov (United States)

    Plomerova, Jaroslava; Babuska, Vladislav

    2017-04-01

    Teleseismic body-wave tomography represents powerful tool to study regional velocity structure of the upper mantle and to image velocity anomalies, such as subducted lithosphere plates in collisional zones. In this contribution, we recapitulate 3D models of the upper mantle beneath the Alps, which developed at a collision zone of the Eurasian and African plates. Seismic tomography studies indicate a leading role of the rigid mantle lithosphere that functioned as a major stress guide during the plate collisions. Interactions of the European lithosphere with several micro-plates in the south resulted in an arcuate shape of this mountain range on the surface and in a complicated geometry of the Alpine subductions in the mantle. Early models with one bended lithosphere root have been replaced with more advanced models showing two separate lithosphere roots beneath the Western and Eastern Alps (Babuska et al., Tectonophysics 1990; Lippitsch et al., JGR 2003). The standard isotropic velocity tomography, based on pre-AlpArray data (the currently performed passive seismic experiment in the Alps and surroundings) images the south-eastward dipping curved slab of the Eurasian lithosphere in the Western Alps. On the contrary, beneath the Eastern Alps the results indicate a very steep northward dipping root that resulted from the collision of the European plate with the Adriatic microplate. Dando et al. (2011) interpret high-velocity heterogeneities at the bottom of their regional tomographic model as a graveyard of old subducted lithospheres. High density of stations, large amount of rays and dense ray-coverage of the volume studied are not the only essential pre-requisites for reliable tomography results. A compromise between the amount of pre-processed data and the high-quality of the tomography input (travel-time residuals) is of the high importance as well. For the first time, the existence of two separate roots beneath the Alps has been revealed from carefully pre-processed

  14. Black hole solutions surrounded by perfect fluid in Rastall theory

    Science.gov (United States)

    Heydarzade, Y.; Darabi, F.

    2017-08-01

    In this work, we obtain uncharged∖charged Kiselev-like black holes as a new class of black hole solutions surrounded by perfect fluid in the context of Rastall theory. Then, we study the specific cases of the uncharged∖charged black holes surrounded by regular matter like dust and radiation, or exotic matter like quintessence, cosmological constant and phantom fields. By comparing the Kiselev-like black hole solutions in Rastall theory with the Kiselev black hole solutions in GR, we find an effective perfect fluid behavior for the black hole's surrounding field. It is shown that the corresponding effective perfect fluid has interesting characteristic features depending on the different ranges of the parameters in Rastall theory. For instance, Kiselev-like black holes surrounded by regular matter in Rastall theory may be considered as Kiselev black holes surrounded by exotic matter in GR, or Kiselev-like black holes surrounded by exotic matter in Rastall theory may be considered as Kiselev black holes surrounded by regular matter in GR.

  15. Surround suppression and sparse coding in visual and barrel cortices

    Directory of Open Access Journals (Sweden)

    Robert N S Sachdev

    2012-07-01

    Full Text Available During natural vision the entire retina is stimulated. Likewise, during natural tactile behaviors, spatially extensive regions of the somatosensory surface are co-activated. The large spatial extent of naturalistic stimulation means that surround suppression, a phenomenon whose neural mechanisms remain a matter of debate, must arise during natural behavior. To identify common neural motifs that might instantiate surround suppression across modalities, we review models of surround suppression and compare the evidence supporting the competing ideas that surround suppression has either cortical or sub-cortical origins in visual and barrel cortex. In the visual system there is general agreement lateral inhibitory mechanisms contribute to surround suppression, but little direct experimental evidence that intracortical inhibition plays a major role. Two intracellular recording studies of V1, one using naturalistic stimuli (Haider et al., 2010, the other sinusoidal gratings (Ozeki et al., 2009, sought to identify the causes of reduced activity in V1 with increasing stimulus size, a hallmark of surround suppression. The former attributed this effect to increased inhibition, the latter to largely balanced withdrawal of excitation and inhibition. In rodent primary somatosensory barrel cortex, multi-whisker responses are generally weaker than single whisker responses, suggesting multi-whisker stimulation engages similar surround suppressive mechanisms. The origins of suppression in S1 remain elusive: studies have implicated brainstem lateral/internuclear interactions and both thalamic and cortical inhibition. Although the anatomical organization and instantiation of surround suppression in the visual and somatosensory systems differ, we consider the idea that one common function of surround suppression, in both modalities, is to remove the statistical redundancies associated with natural stimuli by increasing the sparseness or selectivity of sensory

  16. Mercury's interior, surface, and surrounding environment latest discoveries

    CERN Document Server

    Clark, Pamela Elizabeth

    2015-01-01

    This SpringerBrief details the MESSENGER Mission, the findings of which present challenges to widely held conventional views and remaining mysteries surrounding the planet. The work answers the question of why Mercury is so dense, and the implications from geochemical data on its planetary formation. It summarizes imaging and compositional data from the terrestrial planet surface processes and explains the geologic history of Mercury.  It also discusses the lack of southern hemisphere coverage. Our understanding of the planet Mercury has been in a transitional phase over the decades since Mariner 10. The influx of new data from the NASA MESSENGER Mission since it was inserted into the orbit of Mercury in March of 2011 has greatly accelerated that shift. The combined compositional data of relatively high volatiles (S, K), relatively low refractories (Al, Ca), and low crustal iron, combined with an active, partially molten iron rich core, has major implications for Mercury and Solar System formation. From a s...

  17. Prevalence and diagnostic validity of motivational impairments and deficits in visuospatial short-term memory and working memory in ADHD subtypes

    NARCIS (Netherlands)

    Dovis, S.; van der Oord, S.; Huizenga, H.M.; Wiers, R.W.; Prins, P.J.M.

    2015-01-01

    Deficits in working memory (WM) and reinforcement sensitivity are thought to give rise to symptoms in the combined (ADHD-C) and inattentive subtype (ADHD-I) of ADHD. Children with ADHD are especially impaired on visuospatial WM, which is composed of short-term memory (STM) and a central executive. A

  18. Attention Problems, Phonological Short-Term Memory, and Visuospatial Short-Term Memory: Differential Effects on Near- and Long-Term Scholastic Achievement

    Science.gov (United States)

    Sarver, Dustin E.; Rapport, Mark D.; Kofler, Michael J.; Scanlan, Sean W.; Raiker, Joseph S.; Altro, Thomas A.; Bolden, Jennifer

    2012-01-01

    The current study examined individual differences in children's phonological and visuospatial short-term memory as potential mediators of the relationship among attention problems and near- and long-term scholastic achievement. Nested structural equation models revealed that teacher-reported attention problems were associated negatively with…

  19. Do Children with Autism Use Inner Speech and Visuospatial Resources for the Service of Executive Control? Evidence From Suppression in Dual Tasks

    Science.gov (United States)

    Holland, Lucy; Low, Jason

    2010-01-01

    Three experiments used dual-task suppression methodology to study the use of inner speech and visuospatial resources for mediating central executive performance by children with autism (CWA) and group-matched typically developing (TD) controls. Expt 1 revealed that CWA did not recruit inner speech to facilitate arithmetic task-switching…

  20. Attention Problems, Phonological Short-Term Memory, and Visuospatial Short-Term Memory: Differential Effects on Near- and Long-Term Scholastic Achievement

    Science.gov (United States)

    Sarver, Dustin E.; Rapport, Mark D.; Kofler, Michael J.; Scanlan, Sean W.; Raiker, Joseph S.; Altro, Thomas A.; Bolden, Jennifer

    2012-01-01

    The current study examined individual differences in children's phonological and visuospatial short-term memory as potential mediators of the relationship among attention problems and near- and long-term scholastic achievement. Nested structural equation models revealed that teacher-reported attention problems were associated negatively with…

  1. Factors Influencing Learner Conceptions of Force: Exploring the Interaction among Visuospatial Ability, Motivation, and Conceptions of Newtonian Mechanics in University Undergraduates from an Evolutionary Perspective

    Science.gov (United States)

    Vallett, David Bruce

    2013-01-01

    This study examined the relationships among visuospatial ability, motivation to learn science, and learner conceptions of force across commonly measured demographics with university undergraduates with the aim of examining the support for an evolved sense of force and motion. Demographic variables of interest included age, ethnicity, and gender,…

  2. Optimization of Apparatus Design and Behavioral Measures for the Assessment of Visuo-Spatial Learning and Memory of Mice on the Barnes Maze

    Science.gov (United States)

    O'Leary, Timothy P.; Brown, Richard E.

    2013-01-01

    We have previously shown that apparatus design can affect visual-spatial cue use and memory performance of mice on the Barnes maze. The present experiment extends these findings by determining the optimal behavioral measures and test procedure for analyzing visuo-spatial learning and memory in three different Barnes maze designs. Male and female…

  3. Mechanisms of Deficit of Visuospatial Attention Shift in Children with Developmental Coordination Disorder: A Neurophysiological Measure of the Endogenous Posner Paradigm

    Science.gov (United States)

    Tsai, Chia-Liang; Pan, Chien-Yu; Cherng, Rong-Ju; Hsu, Ya-Wen; Chiu, Hsing-Hui

    2009-01-01

    The purpose of this study was to investigate and compare the mechanisms of brain activity, as revealed by a combination of the visuospatial attention shifting paradigm and event-related potentials (ERP) in children with developmental coordination disorder (DCD) and typically developing children. Twenty-eight DCD children and 26 typically…

  4. The water exchange between Chinchorro Bank and its surroundings

    Science.gov (United States)

    Candela, Julio; Ochoa, Jose Luis; Sheinbaum, Julio; Lopez, Manuel; Cornado, Cesar

    2015-04-01

    Chinchorro Bank is a relatively large (~500 km^ 2) atoll situated 33 km in front of the Yucatan Peninsula in the Caribbean coast of Mexico. Two years of continuous measurements of the subsurface pressure field inside and around Chinchorro Bank, along with currents and waves observed outside, suggest four major processes governing the water exchange of the Bank with its surroundings: 1) surface wave pumping of water into the Bank through its eastern edge, 2) the large scale circulation in the region that drives the sea level changes through geostrophy, 3) the tidal pumping with imposed cyclic flows into and out of the Bank and 4) the imposed drift by the wind. Waves impinging all along the eastern barrier reef induce water inflows (from overtopping the reef) and generate a pressure gradient that drives a drift from east to west throughout the Bank. This western drift can normally replenish the water over the Bank with a time scale of ~10 days. However, extreme wave events, lasting around 24 hours, can replenish the whole Bank's water in the order of day. The region's large scale circulation is dominated by the zonal Cayman Current impinging on the Yucatan Peninsula becoming the Yucatan Current as it turns northward. Variability in the strength and impacting latitude of this current causes sea level gradients within the Bank, i.e., a Yucatan Current increase of 1 m/s, over a period of a couple of weeks, sets up a zonal sea level gradient within that can replenish the whole Bank's water in a time scale of ~14 days. At such times, the large scale current around the Bank is at a maximum thus ensuring an effective removal and dispersal of the exported waters. The Bank has a micro-tidal regime with a semidiurnal amplitude of ~12 cm during spring tides and a diurnal of ~2 cm, these imply that the Bank is exchanging ~10% of its waters with its surroundings daily. However small, this tidal pumping is effective for the ventilation of the Banks' waters in ~10 days due to the

  5. Cognitive Interference from Background Television: Structural Effects on Verbal and Spatial Processing.

    Science.gov (United States)

    Armstrong, G. Blake

    1993-01-01

    Investigates whether background television produces structural interference with aspects of cognitive processing. Finds a significant deleterious effect on a geometric analogies and completion task involving visuo-spatial processing and marginal improvement on a parallel verbal analogy test. Shows that concurrent television exposure had no…

  6. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real‐world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  7. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real-world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  8. Traditional Indian custOInS surrounding birth

    African Journals Online (AJOL)

    traditional custOIns surrounding birth in Indian culture. ... conception, pregnancy, birth and the early months ofparenthood. .... house attended by a traditional birth attendant of a ..... Spiritual components play a dominant role in traditional.

  9. Glow phenomenon surrounding the vertical stabilizer and OMS pods

    Science.gov (United States)

    1994-01-01

    This 35mm frame, photographed as the Space Shuttle Columbia was orbiting Earth during a 'night' pass, documents the glow phenomenon surrounding the vertical stabilizer and the Orbital Maneuvering System (OMS) pods of the spacecraft.

  10. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    OpenAIRE

    Hao Sun; Huanxin Zou; Shilin Zhou; Cheng Wang; Naser El-Sheimy

    2013-01-01

    Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searc...

  11. Differences between nicotine-abstinent smokers and non-smokers in terms of visuospatial attention and inhibition before and after single-blind nicotine administration.

    Science.gov (United States)

    Logemann, H N A; Böcker, K B E; Deschamps, P K H; Kemner, C; Kenemans, J L

    2014-09-26

    The cholinergic system is implicated in visuospatial attention and inhibition, however the exact role is still unclear. Two key mechanisms in visuospatial attention are bias and disengagement. Bias refers to neuronal signals that enhance the sensitivity of the sensory cortex, disengagement is the decoupling of attention. Previous studies suggest that nicotine affects disengagement and (related) inhibition. However the exact relation is still unknown. Furthermore, nicotine-abstinence in 'healthy' smokers may resemble some anomalies of visuospatial attention and inhibition as seen in Attention Deficit/Hyperactivity Disorder (ADHD). Smokers and non-smokers (32 male students) performed in a visuospatial cueing (VSC) task, to assess bias and disengagement, and in a stop-signal task (SST) to assess inhibition. It was expected that nicotine abstinent smokers compared to non-smokers, would show poor disengagement (indicated by an enhanced validity effect) and poor inhibitory control (indicated by an enhanced stop-signal reaction time (SSRT)). It was expected that nicotine would positively affect disengagement and inhibition: hypothesis 1 stated that this effect would be larger in smokers as opposed to non-smokers, in terms of smoking-related deficient inhibitory control. Hypothesis 2 stated the exact opposite, in terms of drug-tolerance. Results indicated no baseline differences. Nicotine enhanced inhibition more in non-smokers relative to smokers. Integrating the results, nicotine-abstinent smokers do not seem to resemble ADHD patients, and do not seem to smoke in order to self-medicate a pre-existing deficit pertaining to mechanisms of visuospatial attention and inhibition. Nicotine may affect inhibition more in non-smokers relative to smokers, consistent with a drug-tolerance account.

  12. β2-adrenoceptor stimulation restores frontal cortex plasticity and improves visuospatial performance in hidden-prenatally-malnourished young-adult rats.

    Science.gov (United States)

    Sáez-Briones, Patricio; Soto-Moyano, Rubén; Burgos, Héctor; Castillo, Amparo; Valladares, Luis; Morgan, Carlos; Pérez, Hernán; Barra, Rafael; Constandil, Luis; Laurido, Claudio; Hernández, Alejandro

    2015-03-01

    Moderate reduction in dietary protein composition of pregnant rats from 25% to 8% casein, calorically compensated by carbohydrates, has been described as a "hidden malnutrition" because it does not alter body and brain weights of pups at birth. However, this dietary treatment leads to altered central noradrenergic systems, impaired cortical long-term potentiation (LTP) and worsened visuo-spatial memory performance. Given the increasing interest on the role played by β2-adrenoceptors (β2-ARs) on brain plasticity, the present study aimed to address the following in hidden-malnourished and eutrophic control rats: (i) the expression levels of β2-ARs in the frontal cortex determined by immunohistochemistry, and (ii) the effect of the β2 selective agonist clenbuterol on both LTP elicited in vivo in the prefrontal cortex and visuospatial performance measured in an eight-arm radial maze. Our results showed that, prenatally malnourished rats exhibited a significant reduction of neocortical β2-AR expression in adulthood. Concomitantly, they were unable to elicit and maintain prefrontal cortex LTP and exhibited lower visuospatial learning performance. Administration of clenbuterol (0.019, 0.038 and 0.075 mg/kg i.p.) enhanced LTP in malnourished and control animals and restored visuospatial learning performance in malnourished but not in normal rats, in a dose-dependent manner. The results suggest that decreased density of neocortical β2-ARs during postnatal life, subsequent to hidden prenatal malnutrition might affect some synaptic networks required to elicit neocortical LTP and form visuospatial memory, since those neuroplastic deficits were counteracted by β2-AR stimulation.

  13. Competitive interactions of attentional resources in early visual cortex during sustained visuospatial attention within or between visual hemifields: evidence for the different-hemifield advantage.

    Science.gov (United States)

    Walter, Sabrina; Quigley, Cliodhna; Mueller, Matthias M

    2014-05-01

    Performing a task across the left and right visual hemifields results in better performance than in a within-hemifield version of the task, termed the different-hemifield advantage. Although recent studies used transient stimuli that were presented with long ISIs, here we used a continuous objective electrophysiological (EEG) measure of competitive interactions for attentional processing resources in early visual cortex, the steady-state visual evoked potential (SSVEP). We frequency-tagged locations in each visual quadrant and at central fixation by flickering light-emitting diodes (LEDs) at different frequencies to elicit distinguishable SSVEPs. Stimuli were presented for several seconds, and participants were cued to attend to two LEDs either in one (Within) or distributed across left and right visual hemifields (Across). In addition, we introduced two reference measures: one for suppressive interactions between the peripheral LEDs by using a task at fixation where attention was withdrawn from the periphery and another estimating the upper bound of SSVEP amplitude by cueing participants to attend to only one of the peripheral LEDs. We found significantly greater SSVEP amplitude modulations in Across compared with Within hemifield conditions. No differences were found between SSVEP amplitudes elicited by the peripheral LEDs when participants attended to the centrally located LEDs compared with when peripheral LEDs had to be ignored in Across and Within trials. Attending to only one LED elicited the same SSVEP amplitude as Across conditions. Although behavioral data displayed a more complex pattern, SSVEP amplitudes were well in line with the predictions of the different-hemifield advantage account during sustained visuospatial attention.

  14. Control of Formation of Lithological Reservoirs by Surrounding Mudstone

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Taking the Jiyang depression as an example, this paper discusses the control of the formation of lithological reservoir by surrounding rocks by integrated application of geological analysis, physical simulation, and the analysis of oil & gas accumulation mechanism. Geological statistical shows that the major burial depth and interval of lithological reservoirs in the Jiyang depression are related to the hydrocarbon generation in and expulsion from the Lower Tertiary source rocks and the time of the formation of most lithological reservoirs coincides with the peak of hydrocarbon generation and expulsion. The lithological traps located in the center of effective source rocks are propitious to high oil saturation than those located on the margin of effective source rocks. The hydrocarbon charge degree of the lithological reservoir has a positive correlation with the intensity of hydrocarbon expulsion from surrounding source rocks.Geological analyses and NMR experiments also show that the oil saturation of surrounding source rocks control the hydrocarbon potential of lithological traps, and a critical value for oil saturation of surrounding mudstone is required, that is, when the oil saturation of surrounding mudstone is lower than this critical value, no oil and gas accumulate in the lithological trap. The control of surrounding mudstone on the oil-bearing properties of lithological reservoirs is also analyzed by the mechanisms of hydrocarbon generation and expulsion as well as accumulation.

  15. Abnormalities in Pattern of Lateralization in Relation to Visuospatial Short Term Memory in Children with Williams Syndrome

    Directory of Open Access Journals (Sweden)

    Antonios Chasouris

    2014-01-01

    Full Text Available Williams syndrome (WS is a genetic disorder characterised by significant intellectual disability. Initial studies indicate that children with WS have a profound bias for information in the top left of visual arrays. Study 1, using a visuospatial memory test for items presented in a 3×3 matrix, found a significant top left bias in WS children relative to controls. Study 2 used a probe-based memory test with arrays in which items appeared with equal probability in each position. Relative to controls, WS children showed a significant top and left bias. In Study 3, the same children engaged in a visual search task and again, a top and left bias was found in the WS group. It is concluded that children with WS display atypical laterality, which might be explained by abnormal saccadic movements, by abnormalities involving development of the dorsal stream or by uneven cortical development.

  16. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  17. Low-frequency transcranial magnetic stimulation over left dorsal premotor cortex improves the dynamic control of visuospatially cued actions

    Science.gov (United States)

    Ward, Nick S.; Bestmann, Sven; Hartwigsen, Gesa; Weiss, Michael M.; Christensen, Lars O.D.; Frackowiak, Richard S.J.; Rothwell, John C.; Siebner, Hartwig R.

    2013-01-01

    Left rostral dorsal premotor cortex (rPMd) and supramarginal gyrus (SMG) have been implicated in the dynamic control of actions. In 12 right-handed healthy individuals we applied 30 minutes of low-frequency (1Hz) repetitive transcranial magnetic stimulation (rTMS) over left rPMd to investigate the involvement of left rPMd and SMG in the rapid adjustment of actions guided by visuospatial cues. After rTMS, subjects underwent functional magnetic resonance imaging while making spatially congruent button presses with right or left index finger in response to a left- or right-sided target. Subjects were asked to covertly prepare motor responses as indicated by a directional cue presented one second before the target. On 20% of trials the cue was invalid requiring subjects to re-adjust their motor plan according to the target location. Compared to sham rTMS, real rTMS increased the number of correct responses in invalidly cued trials. After real rTMS, task-related activity of the stimulated left rPMd showed increased task-related coupling with activity in ipsilateral SMG and adjacent anterior intraparietal area (AIP). Individuals who showed a stronger increase in left-hemispheric premotor-parietal connectivity also made fewer errors on invalidly cued trials after rTMS. The results suggest that rTMS over left rPMd improved the ability to dynamically adjust visuospatial response mapping by strengthening left-hemispheric connectivity between rPMd and the SMG-AIP region. These results support the notion that left rPMd and SMG-AIP contribute towards dynamic control of actions, and demonstrate that low-frequency rTMS can enhance functional coupling between task-relevant brain regions and improve some aspects of motor performance. PMID:20610756

  18. Deficient visuospatial working memory functions and neural correlates of the default-mode network in adolescents with autism spectrum disorder.

    Science.gov (United States)

    Chien, Hsiang-Yun; Gau, Susan Shur-Fen; Isaac Tseng, Wen-Yih

    2016-10-01

    In addition to the essential features of autism spectrum disorder (ASD), namely social communication deficits and repetitive behaviors, individuals with ASD may suffer from working memory deficits and an altered default-mode network (DMN). We hypothesized that an altered DMN is related to working memory deficits in those with ASD. A total of 37 adolescents with ASD and 36 age- and IQ-matched typically developing (TD) controls were analyzed. Visuospatial working memory performance was assessed using pattern recognition memory (PRM), spatial recognition memory (SRM), and paired-associates learning (PAL) tasks. The intrinsic functional connectivity (iFC) of the DMN was indexed by the temporal correlations between the resting-state functional magnetic resonance imaging signals of pairs of DMN regions, including those between the posterior cingulate cortex (PCC) and medial prefrontal cortex (mPFC) and between the PCC and parahippocampi (PHG). The corresponding structural connectivity of the DMN was indexed by the generalized fractional anisotropy (GFA) of the dorsal and ventral cingulum bundles on the basis of diffusion spectrum imaging data. The results showed that ASD adolescents exhibited delayed correct responses in PRM and SRM tasks and committed more errors in the PAL task than the TD controls did. The delayed responses during the PRM and SRM tasks were negatively correlated with bilateral PCC-mPFC iFCs, and PAL performance was negatively correlated with right PCC-PHG iFC in ASD adolescents. Furthermore, ASD adolescents showed significant lower GFA in the right cingulum bundles than the TD group did; the GFA value was negatively correlated with SRM performance in ASD. Our results provide empirical evidence for deficient visuospatial working memory and corresponding neural correlates within the DMN in adolescents with ASD. Autism Res 2016, 9: 1058-1072. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  19. Male-typical visuospatial functioning in gynephilic girls with gender dysphoria — organizational and activational effects of testosterone

    Science.gov (United States)

    Burke, Sarah M.; Kreukels, Baudewijntje P.C.; Cohen-Kettenis, Peggy T.; Veltman, Dick J.; Klink, Daniel T.; Bakker, Julie

    2016-01-01

    Background Sex differences in performance and regional brain activity during mental rotation have been reported repeatedly and reflect organizational and activational effects of sex hormones. We investigated whether adolescent girls with gender dysphoria (GD), before and after 10 months of testosterone treatment, showed male-typical brain activity during a mental rotation task (MRT). Methods Girls with GD underwent fMRI while performing the MRT twice: when receiving medication to suppress their endogenous sex hormones before onset of testosterone treatment, and 10 months later during testosterone treatment. Two age-matched control groups participated twice as well. Results We included 21 girls with GD, 20 male controls and 21 female controls in our study. In the absence of any group differences in performance, control girls showed significantly increased activation in frontal brain areas compared with control boys (pFWE = 0.012). Girls with GD before testosterone treatment differed significantly in frontal brain activation from the control girls (pFWE = 0.034), suggesting a masculinization of brain structures associated with visuospatial cognitive functions. After 10 months of testosterone treatment, girls with GD, similar to the control boys, showed increases in brain activation in areas implicated in mental rotation. Limitations Since all girls with GD identified as gynephilic, their resemblance in spatial cognition with the control boys, who were also gynephilic, may have been related to their shared sexual orientation rather than their shared gender identity. We did not account for menstrual cycle phase or contraceptive use in our analyses. Conclusion Our findings suggest atypical sexual differentiation of the brain in natal girls with GD and provide new evidence for organizational and activational effects of testosterone on visuospatial cognitive functioning. PMID:27070350

  20. Test of visuospatial construction: Validity evidence in extremely low birth weight and late preterm children at early school age.

    Science.gov (United States)

    Rider, G Nicole; Weiss, Brandi A; McDermott, Adam T; Hopp, Crista A; Baron, Ida Sue

    2016-01-01

    The Test of Visuospatial Construction (TVSC), a measure of visuoconstruction that does not rely on upper extremity motor response or written production, was administered to extremely low birth weight (ELBW), late preterm (LPT), and term participants at preschool (n = 355) and kindergarten (n = 265) ages. TVSC showed statistically significant weak-to-moderate positive correlations (age 3: r = .118-.303; age 6: r = .138-.348) with Developmental VMI, Differential Ability Scales-II Copying, Matrices, and Pattern Construction subtests, Baron-Hopkins Board Test, and the Purdue Pegboard. One-way ANOVA indicated ELBW performed worse than Term (p = .044) on visuospatial construction at age 3 with a small-to-medium effect size (d = -0.43). No other statistically significant differences were found at age 3 on the TVSC (ELBW/LPT: p = .608, d = -0.17; LPT/Term: p = .116, d = -0.31). At age 6, ELBW participants performed worse than LPT participants (p = .027) and Term participants (p = .012); LPT participants did not differ from Term participants. Small effect sizes at age 3 (ELBW < LPT, d = -0.17; ELBW < Term, d = -0.43) were notably larger at age 6 (ELBW < LPT, d = -0.42; ELBW < Term, d = -0.53). Important practical differences showing LPT participants performed below Term participants (d = -0.31) at age 3 were no longer evident at age 6 (d = -0.097). These findings provide preliminary evidence of TVSC validity supporting its use to detect neuropsychological impairment and to recommend appropriate interventions in young preterm children.

  1. Rain Simulation for the Test of Automotive Surround Sensors

    Science.gov (United States)

    Hasirlioglu, Sinan; Riener, Andreas; Doric, Igor

    2017-04-01

    The WHO Global Health Observatory data indicates that over 1.25 million people die in traffic accidents annually. To save lives, car manufacturers spend lot of efforts on the development of novel safety systems aiming to avoid or mitigate accidents and provide maximum protection for vehicle occupants as well as vulnerable road users. All the safety features mainly rely on data from surround sensors such as radar, lidar and camera and intelligent vehicles today use these environmental data for instant decision making and vehicle control. As already small errors in sensor data measurements could lead to catastrophes like major injuries or road traffic fatalities, it is of utmost importance to ensure high reliability and accuracy of sensors and safety systems. This work focuses on the influence of environmental factors such as rain conditions, as it is known that rain drops scatter the electromagnetic waves. The result is incorrect measurements with a direct negative impact on environment detection. To identify potential problems of sensors under varying environmental conditions, systems are today tested in real-world settings with two main problems: First, tests are time-consuming and second, environmental conditions are not reproducible. Our approach to test the influence of weather on automotive sensors is to use an indoor rain simulator. Our artificial rain maker, installed at CARISSMA (Center of Automotive Research on Integrated Safety Systems and Measurement Area), is parametrized with rain characteristics measured in the field using a standard disdrometer. System behavior on artificial rain is compared and validated with natural rainfall. With this simulator it is finally possible to test environmental influence at various levels and under reproducible conditions. This saves lot of efforts required for the test process itself and furthermore has a positive impact on the reliability of sensor systems due to the fact that test driven development is enabled.

  2. 6.1 channel general planar surround sound system

    Institute of Scientific and Technical Information of China (English)

    XIE Bosun

    2001-01-01

    A new 6.1 channel surround sound system and its two signal mixing methods are proposed. Theoretical and experimental results show that the system is able to recreate 360°sound image in horizontal plane. Especially, compared with current 5.1 channel system, lateral and rear image of the new system is improved obviously. Therefore it is suitable to be used as a general surround sound system. It is also proved that, the new system is fully compatible with 5.1 channel system, and current methods are available to record 6.1 channel signals.

  3. Linking disadvantaged housing areas to the surrounding city

    DEFF Research Database (Denmark)

    Stender, Marie

    Several disadvantaged social housing areas in Denmark are currently undergo-ing thorough physical refurbishments, aiming to integrate them better with the surrounding city. The ambition is to attract new users and residents by opening up the borders of the area and establish attractive, new...... that especially eve-ryday-route strategies adding new public functions within the area can pave the way for integration with the surroundings. The applicability of such strategies is however highly dependent on the context, location and existing image of the ar-ea. Social distance may sustain though physical...

  4. Alternating sequential operators from center-surround top-hat transform

    Science.gov (United States)

    Bai, Xiangzhi

    2013-06-01

    Constructing alternating sequential operators is the important way of improving the efficiency of morphological operations for image processing. And, the alternating sequential filters (ASFs), which are constructed by using the morphological opening and closing, have been the important alternating sequential operators of mathematical morphology. However, because the morphological opening and closing operations have the defect of image detail smoothing, ASFs could not perform very well for some detail preserving image processing applications. Center-surround top-hat transform has been proposed through reconstructing the used structuring elements following the properties of image regions, which ensures that the main operations in center-surround top-hat transform could protect some image details; and, the main operations in center-surround top-hat transform achieve the similar function as opening and closing for bright and black feature extraction. Therefore, based on center-surround top-hat transform, some new and effective alternating sequential operators may be constructed. In light of this, a new class of alternating sequential operators with improved performance based on the center-surround top-hat transform is proposed in this paper. The definition and properties of the new alternating sequential operators are given and analyzed. Also, an application of impulsive noise suppression is used to show the improved performance of the new alternating sequential operators comparing with ASFs. Moreover, because the new alternating sequential operators constructed in this paper have some superiorities over ASFs, they could be also widely used in different applications in which the ASFs perform well, which indicates that the new alternating sequential operators may be also a class of useful morphological operators for image analysis.

  5. Metrizamide demonstration of the subarachnoid space surrounding the Gasserian ganglion

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, D.; Babin, E.

    1980-05-01

    The chance opacification of the subarachnoid space surrounding the Gasserian ganglion, observed during metrizamide basal cisternography, is reported. This is compared to similar demonstrations of the optic subarachnoid space. Such infrequently observed images should be known because they may be related to the occurrence of trigeminal neuralgia.

  6. Orientation-tuned surround suppression in mouse visual cortex

    NARCIS (Netherlands)

    Self, Matthew W; Lorteije, Jeannette A M; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N; Heimel, J.A.; Roelfsema, Pieter R

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those contai

  7. Challenges Surrounding the Education of Children with Chronic Diseases

    Science.gov (United States)

    Gordon, Maria, Ed.

    2016-01-01

    While governing bodies have mandated that all students have the right to an education, with disabled students treated to the same rights and opportunities as non-disabled students, policymakers do not always agree on what all-inclusive education should look like. "Challenges Surrounding the Education of Children with Chronic Diseases"…

  8. Center-surround antagonism in spatial vision: retinal or cortical locus?

    Science.gov (United States)

    Westheimer, Gerald

    2004-01-01

    Mach and Hering had early advanced a model of spatial visual processing featuring an antagonistic interaction between adjoining areas in the visual field. Spatial opponency was one of the first findings when single-unit studies of the retina were begun. Not long afterwards psychophysical experiments revealed a center-surround organization closely matching that found in the mammalian retina. It hinged on the demonstration of reduction of sensitivity in a small patch of the visual field when its surround was changed from dark to bright. Because such patterns inevitably produce borders, well-known phenomena of border interaction could be seen as providing alternative explanations, whose substrate would most likely be in the visual cortex. These competing viewpoints are discussed especially as they pertain to the recent demonstration of spatial differences in the center/surround organization between the normal and affected eyes of amblyopes. To the extent that most findings favor a retinal site for the psychophysically measured antagonism, and that evidence is accumulating for a direct effect on the mammalian retina of stimulus manipulation during visual development, the difference in spatial parameters of center/surround antagonism in amblyopia suggests that the dysfunction in amblyopia begins already in the retina.

  9. Military installation sequestered more carbon than surrounding areas

    Science.gov (United States)

    Zhao, S.; Liu, S.; Li, Z.; Sohl, T.

    2008-12-01

    Land use activities greatly affect the temporal trends and spatial patterns of regional land-atmospheric exchange of carbon. Military installations generally have drastically different land management strategies from surrounding areas, and the carbon consequences have never been quantified and assessed. Here, we used the General Ensemble Biogeochemical Modeling System (GEMS) to simulate and compare ecosystem carbon dynamics between Fort Benning and surrounding areas from 1992 to 2050. GEMS was driven by unique combinations of spatial and temporal dynamics of major driving forces, such as climate, soil properties, nitrogen deposition, and land use and land cover changes (predicted by FOREcasting SCEnarios of land cover change (FORE-SCE)). Our results indicated that the military installation sequestered more carbon than surrounding areas (0.77 vs. 0.16 Mg C ha-1 y-1 averaged from 1992 to 2007). Differences in land use activities were the primary cause behind the difference in carbon sequestration rates. From 1992 to 2007, no urban/residential expansion occurred at the installation, and transitional barren (primarily caused by forest harvesting) slightly increased from 0 to 0.2%. In contrast, urban land increased from 5.6 to 7.6% and transitional barren increased from 0.1 to 0.7% in the surrounding areas. Live biomass accumulation accounted for most of the carbon sink in both Fort Benning and surrounding areas (0.75 vs. 0.15 Mg C ha-1 y-1), while soil organic carbon accumulation was small (0.02 vs. 0.01 Mg C ha- 1 y-1), suggesting biomass removal caused by urbanization and harvesting resulted in much less carbon sequestration in surrounding areas. Fort Benning is likely to sequester more carbon in the future, although the rate of carbon sequestered per year will gradually reduce. The future carbon source/sink strength in the surrounding areas varied greatly, from a small sink to a strong source, depending on the path of land use change (e.g., increase of clear

  10. The Kohs' blocks test as an important instrument to investigate the visuo-spatial impairments in myotonic dystrophy: part I. Quantitative and qualitative analysis

    Directory of Open Access Journals (Sweden)

    WIGG CRISTINA MARIA DUARTE

    1999-01-01

    Full Text Available This study presents the performance of 39 cases of myotonic dystrophy on Kohs' blocks test (21 females and 18 males, age range from 9 to 70 years. On this test, the patients have to reproduce figures from models previously showed to them. Some of the patients had some kind of professional activity, while others had never exerted a professional occupation. The patients denoted considerable difficulty to perform the test. Some cases constructed entirely different figures in comparison to the presented drawings, translating visuo-spatial and constructional disabilities. The performance was insufficient in 71.4 % of the cases. These cases solved less than 50% of the test. The levels of analysis and synthesis were severely impaired. A total of 18 cases got less than 10 points, not reaching 20% of the test. The results showed the sensitivity of this test in detecting visuo-spatial impairment in myotonic dystrophy.

  11. Contribution of working memory in multiplication fact network in children may shift from verbal to visuo-spatial: A longitudinal investigation

    Directory of Open Access Journals (Sweden)

    Mojtaba eSoltanlou

    2015-07-01

    Full Text Available Number facts are commonly assumed to be verbally stored in an associative multiplication fact retrieval network. Prominent evidence for this assumption comes from so-called operand-related errors (e.g. 4 × 6 = 28. However, little is known about the development of this network in children and its relation to verbal and non-verbal memories. In a longitudinal design, we explored elementary school children from grades 3 and 4 in a multiplication verification task with the operand-related and -unrelated distractors. We examined the contribution of multiplicative fact retrieval by verbal and visuo-spatial short-term and working memory. Children in grade 4 showed smaller reaction times in all conditions. However, there was no significant difference in errors between grades. Contribution of verbal and visuo-spatial working memory also changed with grade. Multiplication correlated with verbal working memory and performance in grade 3 but with visuo-spatial working memory and performance in grade 4. We suggest that the relation to verbal working memory in grade 3 indicates primary linguistic learning of and access to multiplication in grade 3 which is probably based on verbal repetition of the multiplication table heavily practiced in grades 2 and 3. However, the relation to visuo-spatial semantic working memory in grade 4 suggests that there is a shift from verbal to visual and semantic learning in grade 4. This shifting may be induced because later in elementary school, multiplication problems are rather carried out via more written, i.e., visual tasks, which also involve executive functions. More generally, the current data indicates that mathematical development is not generally characterized by a steady progress in performance; rather verbal and non-verbal memory contributions of performance shift over time, probably due to different learning contents.

  12. Prevalence and diagnostic validity of motivational impairments and deficits in visuospatial short-term memory and working memory in ADHD subtypes.

    Science.gov (United States)

    Dovis, Sebastiaan; Van der Oord, Saskia; Huizenga, Hilde M; Wiers, Reinout W; Prins, Pier J M

    2015-05-01

    Deficits in working memory (WM) and reinforcement sensitivity are thought to give rise to symptoms in the combined (ADHD-C) and inattentive subtype (ADHD-I) of ADHD. Children with ADHD are especially impaired on visuospatial WM, which is composed of short-term memory (STM) and a central executive. Although deficits in visuospatial WM and reinforcement sensitivity appear characteristic of children with ADHD on a group-level, the prevalence and diagnostic validity of these impairments is still largely unknown. Moreover, studies investigating this did not control for the interaction between motivational impairments and cognitive performance in children with ADHD, and did not differentiate between ADHD subtypes. Visuospatial WM and STM tasks were administered in a standard (feedback-only) and a high-reinforcement (feedback + 10 euros) condition, to 86 children with ADHD-C, 27 children with ADHD-I (restrictive subtype), and 62 typically developing controls (aged 8-12). Reinforcement sensitivity was indexed as the difference in performance between the reinforcement conditions. WM and STM impairments were most prevalent in ADHD-C. In ADHD-I, only WM impairments, not STM impairments, were more prevalent than in controls. Motivational impairments were not common (22% impaired) and equally prevalent in both subtypes. Memory and motivation were found to represent independent neuropsychological domains. Impairment on WM, STM, and/or motivation was associated with more inattention symptoms, medication-use, and lower IQ scores. Similar results were found for analyses of diagnostic validity. The majority of children with ADHD-C is impaired on visuospatial WM. In ADHD-I, STM impairments are not more common than in controls. Within both ADHD subtypes only a minority has an abnormal sensitivity to reinforcement.

  13. Visuo-spatial path learning, stress, and cortisol secretion following military cadets' first parachute jump: the effect of increasing task complexity.

    Science.gov (United States)

    Taverniers, John; Smeets, Tom; Lo Bue, Salvatore; Syroit, Jef; Van Ruysseveldt, Joris; Pattyn, Nathalie; von Grumbkow, Jasper

    2011-09-01

    The present field experiment examined how multi-trial visuo-spatial learning and memory performance are impacted by excessive arousal, instigated by a potentially life-threatening event (i.e., a first parachute jump). Throughout a parachute training activity, subjective and neuroendocrine (i.e., cortisol) stress levels were assessed of 61 male military cadets who were randomly assigned to a control (n = 30) or a jump stress condition (n = 31). Post-stress learning and memory capacity was assessed with a 10-trial path-learning task that permitted emergence of learning curves. Pre-activity cortisol concentrations indicated a significant neuroendocrine anticipatory stress response in the stress group. Following parachuting, subjective stress levels and salivary cortisol reactivity differed significantly between groups. Visuo-spatial path-learning performance was impaired significantly after jump stress exposure, relative to the control group. Moreover, examination of the learning curves showed similar learning and memory performance at onset of the trials, with curves bifurcating as the task became more complex. These findings are in accordance with leading theories that acknowledge a moderating effect of task complexity. In sum, the present study extends knowledge concerning anticipatory stress effects, endogenously instigated cortisol reactivity, and the influence of extreme arousal on visuo-spatial path learning.

  14. The Effect of Functional Hearing Loss and Age on Long- and Short-term Visuospatial Memory: Evidence from the UK Biobank Resource

    Directory of Open Access Journals (Sweden)

    Jerker eRönnberg

    2014-12-01

    Full Text Available The UK Biobank offers cross-sectional epidemiological data collected on > 500 000 individuals in the UK between 40 and 70 years of age. Using the UK Biobank data, the aim of this study was to investigate the effects of functional hearing loss and hearing aid usage on visuospatial memory function. This selection of variables resulted in a sub-sample of 138 098 participants after discarding extreme values. A digit triplets functional hearing test was used to divide the participants into three groups: poor, insufficient and normal hearers. We found negative relationships between functional hearing loss and both visuospatial working memory (i.e., a card pair matching task and visuospatial, episodic long-term memory (i.e., a prospective memory task, with the strongest association for episodic long-term memory. The use of hearing aids showed a small positive effect for working memory performance for the poor hearers, but did not have any influence on episodic long-term memory. Age also showed strong main effects for both memory tasks and interacted with gender and education for the long-term memory task. Broader theoretical implications based on a memory systems approach will be discussed and compared to theoretical alternatives.

  15. The effect of functional hearing loss and age on long- and short-term visuospatial memory: evidence from the UK biobank resource.

    Science.gov (United States)

    Rönnberg, Jerker; Hygge, Staffan; Keidser, Gitte; Rudner, Mary

    2014-01-01

    The UK Biobank offers cross-sectional epidemiological data collected on >500,000 individuals in the UK between 40 and 70 years of age. Using the UK Biobank data, the aim of this study was to investigate the effects of functional hearing loss and hearing aid usage on visuospatial memory function. This selection of variables resulted in a sub-sample of 138,098 participants after discarding extreme values. A digit triplets functional hearing test was used to divide the participants into three groups: poor, insufficient and normal hearers. We found negative relationships between functional hearing loss and both visuospatial working memory (i.e., a card pair matching task) and visuospatial, episodic long-term memory (i.e., a prospective memory task), with the strongest association for episodic long-term memory. The use of hearing aids showed a small positive effect for working memory performance for the poor hearers, but did not have any influence on episodic long-term memory. Age also showed strong main effects for both memory tasks and interacted with gender and education for the long-term memory task. Broader theoretical implications based on a memory systems approach will be discussed and compared to theoretical alternatives.

  16. Dynamics of two-component membranes surrounded by viscoelastic media.

    Science.gov (United States)

    Komura, Shigeyuki; Yasuda, Kento; Okamoto, Ryuichi

    2015-11-01

    We discuss the dynamics of two-component fluid membranes which are surrounded by viscoelastic media. We assume that membrane-embedded proteins can diffuse laterally and induce a local membrane curvature. The mean squared displacement of a tagged membrane segment is obtained as a generalized Einstein relation. When the elasticity of the surrounding media obeys a power-law behavior in frequency, an anomalous diffusion of the membrane segment is predicted. We also consider the situation where the proteins generate active non-equilibrium forces. The generalized Einstein relation is further modified by an effective temperature that depends on the force dipole energy. The obtained generalized Einstein relations are useful for membrane microrheology experiments.

  17. Study on Temperature Fieldof Surrounding Rock with BEM

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The authors analyzed the characteristic of surrounding rock temperature field around a drifting face, setup its mathematic model, and got its numerical result with the boundary element method(BEM). To calculate in-tra-domain integral, it was transformed into boundary integration with the DRM method. Using the similitude the-ory, the dimensionless differential equation was educed. Finally, the authors calculated two drifting faces of San-hejian Coal Mine using the computer software developed by authors based on the above principium, and got the dis-tribution characteristic of surrounding rock temperature field around a drifting face and the periodic variation intemperature with its periodic moving forward. Comparing the calculated heat dissipating-capacity of surroundingrock with the measured data shows that the computer software is proper.

  18. Thermodynamic stability of black holes surrounded by quintessence

    OpenAIRE

    Ma, Meng-Sen; Zhao, Ren; Ma, Ya-Qin

    2016-01-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence $\\omega_q$ is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic q...

  19. Hidden History: A Mobile Application for Discovering Surrounding Landscapes

    OpenAIRE

    2016-01-01

    This thesis work describes the design, development and evaluation of a mobile application called Hidden History. This application lets users discover and explore three types of landscapes (Historic, Scenic and Cultural) using three different modes of discovery (Route, Explore and Tour). Before designing Hidden History, the feature set of other applications that help users explore surrounding landscapes were identified and analyzed. Hidden History was then designed to implement the best fea...

  20. Treatment of Postherpetic Neuralgia by Surround Needling with Electric Stimulation

    Institute of Scientific and Technical Information of China (English)

    FAN Jin; YANG Qin-hua

    2005-01-01

    运用电针围刺法治疗带状疱疹后遗神经痛29例,获得较好疗效,总有效率为93.1%.%Twenty-nine cases of postherpetic neuralgia of herpes zoster were treated by the surround needling with electric stimulation, and the better therapeutic effect was obtained, the total effective rate was 93.1%.

  1. Belief and Attitudes surrounding Childhood Autism in Ghana

    OpenAIRE

    2012-01-01

    Autism is a life-long invisible impairment with an unknown etiology. Current literature shows an increase in the diagnosis of autism worldwide. This qualitative study explores the attitudes and beliefs which surround childhood autism in Ghana. In-depth interviews were conducted with four (4) parents whose children have autism and three (3) key informants; a Religious Leader, a Health Worker and an Administrator of a Special school in Accra, Ghana. A semi-structured interview guide was used fo...

  2. A permeability barrier surrounds taste buds in lingual epithelia.

    Science.gov (United States)

    Dando, Robin; Pereira, Elizabeth; Kurian, Mani; Barro-Soria, Rene; Chaudhari, Nirupa; Roper, Stephen D

    2015-01-01

    Epithelial tissues are characterized by specialized cell-cell junctions, typically localized to the apical regions of cells. These junctions are formed by interacting membrane proteins and by cytoskeletal and extracellular matrix components. Within the lingual epithelium, tight junctions join the apical tips of the gustatory sensory cells in taste buds. These junctions constitute a selective barrier that limits penetration of chemosensory stimuli into taste buds (Michlig et al. J Comp Neurol 502: 1003-1011, 2007). We tested the ability of chemical compounds to permeate into sensory end organs in the lingual epithelium. Our findings reveal a robust barrier that surrounds the entire body of taste buds, not limited to the apical tight junctions. This barrier prevents penetration of many, but not all, compounds, whether they are applied topically, injected into the parenchyma of the tongue, or circulating in the blood supply, into taste buds. Enzymatic treatments indicate that this barrier likely includes glycosaminoglycans, as it was disrupted by chondroitinase but, less effectively, by proteases. The barrier surrounding taste buds could also be disrupted by brief treatment of lingual tissue samples with DMSO. Brief exposure of lingual slices to DMSO did not affect the ability of taste buds within the slice to respond to chemical stimulation. The existence of a highly impermeable barrier surrounding taste buds and methods to break through this barrier may be relevant to basic research and to clinical treatments of taste.

  3. THE DESIGN OF DYNAMIC SIMULATION SYSTEM ON EARTHQUAKE SURROUNDINGS

    Institute of Scientific and Technical Information of China (English)

    沈毅力; 杨云; 李天石

    2003-01-01

    Objective To design a system that can simulate earthquake surroundings. In the surroundings, people can be familiar with the omen, strong shock and aftershock of earthquake, thus make right choices and get away when the disaster occurs. Methods The system consists of an electro-hydraulic servo system, a whole-information sound system and some lighting device; By using the adaptive inverse control method and LMS algorithms, the inverse model (I.e. The controller) is convergent rapidly; The software based on LabVIEW makes the parameters can be modified easily; There is a double closed-loop structure in the system: an analog closed-loop and a digital closed-loop, and their parameters can be inspected in real time. Results The system is of very high reliability, and the desired vibration signal can be tracked exactly by output. Conclusion Earthquake surroundings is simulated vividly. Through the system, people can be familiar with earthquake phenomena, and know lots of knowledge of earthquake.

  4. Tissue reaction surrounding miniscrews for orthodontic anchorage: An animal experiment

    Directory of Open Access Journals (Sweden)

    Stephanie Shih-Hsuan Chen

    2012-03-01

    Results and conclusions: (1 Tissue surrounding roots damaged by a miniscrew showed a significant inflammatory response. (2 Root resorption was occasionally observed after 3 weeks following insertion of a miniscrew even if the miniscrew was not in direct contact with the root. (3 Root repair was noted with a cementoblast lining along the resorption surface at as early as 3 weeks after miniscrew insertion. Alveolar bone filled in the lesion when the root damage was large so that the contour of the alveolar bone followed that of the damaged root, with the width of the periodontal ligament space being maintained. (4 Stable miniscrews were mainly those which did not contact adjacent roots, and for which the surrounding tissue showed only a small inflammatory response with some extent of direct bone contact around the miniscrew. On the contrary, most of the failed miniscrews were those which had direct contact with adjacent roots, and which exhibited severe tissue inflammation and were covered by thick layers of soft tissue. Failure was detected 3 weeks after insertion. Surprisingly, the epithelial lining surrounding the miniscrews might not have spontaneously resolved 6 weeks after screw removal. Persistent infection in the sinus tract was noted, and this would require attention.

  5. Crossed Aphasia and Visuo-Spatial Neglect Following a Right Thalamic Stroke: A Case Study and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Lieve De Witte

    2008-01-01

    Full Text Available Crossed aphasia in dextrals (CAD following pure subcortical lesions is rare. This study describes a right-handed patient with an ischemic lesion in the right thalamus. In the post-acute phase of the stroke, a unique combination of ‘crossed thalamic aphasia’ was found with left visuo-spatial neglect and constructional apraxia. On the basis of the criteria used in Mariën et al. [67], this case-report is the first reliable representative of vascular CAD following an isolated lesion in the right thalamus. Furthermore, this paper presents a detailed analysis of linguistic and cognitive impairments of ‘possible’ and 'reliable' subcortical CAD-cases published since 1975. Out of 25 patients with a pure subcortical lesion, nine cases were considered as ‘possibly reliable or reliable’. A review of these cases reveals that: (1 demographic data are consistent with the general findings for the entire group of vascular CAD, (2 the neurolinguistic findings do not support the data in the general CAD-population with regard to (a the high prevalence of transcortical aphasia and (b the tendency towards a copresence of an oral versus written language dissociation and a ‘mirror-image’ lesion-aphasia profile, (3 subcortical CAD is not a transient phenomenon, (4 the lesion-aphasia correlations are not congruent with the high incidence of anomalous cases in the general CAD-population, (5 neuropsychological impairments may accompany subcortical CAD.

  6. The impact of recovery of visuo-spatial neglect on motor recovery of the upper paretic limb after stroke.

    Directory of Open Access Journals (Sweden)

    Tanja C W Nijboer

    Full Text Available The aim of the current study was to investigate the longitudinal relationship between improvements of synergism and strength of the upper paretic limb and severity of visuo-spatial neglect during the first 52 weeks post-stroke. The longitudinal association between severity of VSN and motor impairment using Fugl Meyer motor score and Motricity Index of the arm was measured in an intensive repeated measurement design including 18 measurement sessions for each subject. Neglect was assessed using the letter cancellation test applied in a prospective cohort of 101 ischemic, first-ever, hemispheric stroke patients. All time-dependent measures were taken weekly, starting within 14 days post-stroke. From week 10 to 20 biweekly measurements are obtained. The longitudinal relationship of (biweekly time on improvement of motor functions and severity of neglect was investigated using random coefficient analysis and trend analyses. Fifty-one of the 101 stroke patients showed neglect at stroke onset. Less improvement of synergism and strength of the upper paretic limb was associated with more severe neglect. This association was most pronounced in the first 10 weeks post-stroke. The seemingly suppressive effect of neglect on upper-limb motor recovery appears to take place mainly during spontaneous neurological recovery of first 10 weeks post-stroke. This finding suggests that damage to large-scale white matter tracts of especially the perceptual-attention networks suppress recovery of other networks at distance in the brain suggesting a common underlying mechanism.

  7. Do You See What I'm Singing? Visuospatial Movement Biases Pitch Perception

    Science.gov (United States)

    Connell, Louise; Cai, Zhenguang G.; Holler, Judith

    2013-01-01

    The nature of the connection between musical and spatial processing is controversial. While pitch may be described in spatial terms such as "high" or "low", it is unclear whether pitch and space are associated but separate dimensions or whether they share representational and processing resources. In the present study, we asked participants to…

  8. Virtual AM Stereo and Surround Sound to setup AM/FM Radio Theatre

    Directory of Open Access Journals (Sweden)

    Selvakumaran Vadivelmurugan

    2003-08-01

    Full Text Available Introduction of virtual surround sound and stereo to AM radio has been proposed in this study. This technology can be further applied to aid the construction of an AM radio theatre. Adding to the advantages of AM, the lower bandwidth, higher range and simpler circuitry, AM can now offer excellent sound effect with the post-transmission process. The motivation for the introduction of virtual surround sound is the poor quality of AM sound. In this study, the response by human ear has been thoroughly investigated and the methodology to create virtual surround sound has been developed. The elements essential to setup audio theatre such as the components of audio chain, multiple unit audio speaker, inner section of the ear, psychological effect of different ranges of frequency and radio theatre design have been extensively studied on the basis of Helmholtz audition theory. The vital changes include the different frequency division multiplexing of message at the transmitting end, three phases of the process, resulting in the vertical and horizontal digital connection, espresso program and the 3x12 speaker design theatre.

  9. INTERACTIONS OF THE INFRARED BUBBLE N4 WITH ITS SURROUNDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong-Li; Li, Jin-Zeng; Yuan, Jing-Hua; Huang, Maohai; Huang, Ya-Fang; Zhang, Si-Ju [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Wu, Yuefang [Department of Astronomy, Peking University, 100871 Beijing (China); Liu, Tie [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Dubner, G.; Paron, S.; Ortega, M. E. [1Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Molinari, Sergio [Istituto di Astrofisica e Planetologia Spaziali—IAPS, Istituto Nazionale di Astrofisica—INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Zavagno, Annie; Samal, Manash R., E-mail: hlliu@nao.cas.cn [Aix Marseille Universit, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

    2016-02-10

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H ii regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the H ii region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 × 10{sup 22} cm{sup −2}, mean volume density of about 4.4 × 10{sup 4} cm{sup −3}, and a mean mass of 320 M{sub ⊙}. In addition, from PAH emission seen at 8 μm, free–free emission detected at 20 cm, and a probability density function in special regions, we could identify clear signatures of the influence of the H ii region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.

  10. On the environment surrounding close-in exoplanets

    Science.gov (United States)

    Vidotto, A. A.; Fares, R.; Jardine, M.; Moutou, C.; Donati, J.-F.

    2015-06-01

    Exoplanets in extremely close-in orbits are immersed in a local interplanetary medium (i.e. the stellar wind) much denser than the local conditions encountered around the Solar system planets. The environment surrounding these exoplanets also differs in terms of dynamics (slower stellar winds, but higher Keplerian velocities) and ambient magnetic fields (likely higher for host stars more active than the Sun). Here, we quantitatively investigate the nature of the interplanetary media surrounding the hot Jupiters HD 46375b, HD 73256b, HD 102195b, HD 130322b and HD 179949b. We simulate the three-dimensional winds of their host stars, in which we directly incorporate their observed surface magnetic fields. With that, we derive mass-loss rates (1.9-8.0 × 10-13 M⊙ yr-1) and the wind properties at the position of the hot Jupiters' orbits (temperature, velocity, magnetic field intensity and pressure). We show that these exoplanets' orbits are supermagnetosonic, indicating that bow shocks are formed surrounding these planets. Assuming planetary magnetic fields similar to Jupiter's, we estimate planetary magnetospheric sizes of 4.1-5.6 planetary radii. We also derive the exoplanetary radio emission released in the dissipation of the stellar wind energy. We find radio fluxes ranging from 0.02 to 0.13 mJy, which are challenging to be observed with present-day technology, but could be detectable with future higher sensitivity arrays (e.g. Square Kilometre Array). Radio emission from systems having closer hot Jupiters, such as from τ Boo b or HD 189733b, or from nearby planetary systems orbiting young stars, are likely to have higher radio fluxes, presenting better prospects for detecting exoplanetary radio emission.

  11. Issues surrounding record keeping in district nursing practice.

    Science.gov (United States)

    Anderson, E E

    2000-07-01

    This article examines some aspects of nursing documentation following the publication of the document 'Guidelines for Records and Record Keeping' (UKCC, 1998). The importance of nursing documentation in patient care, in guiding practice and in providing information for members of the interprofessional healthcare team is highlighted. Record keeping forms an important part of the clinical governance initiative in terms of quality improvement and risk management. The issues surrounding the legal requirements of record keeping in district nursing practice are discussed. Suggestions are made for assessing the quality of nursing documentation by audit and research, in order to establish the suitability of using the present systems in the community setting.

  12. Induced radioactivity in a 4 MW target and its surroundings

    CERN Document Server

    Agosteo, Stefano; Otto, Thomas; Silari, Marco

    2003-01-01

    An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump was performed by the Monte Carlo hadronic cascade code FLUKA. The aim was both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation.

  13. Mutual seismic interaction between tunnels and the surrounding granular soil

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Abdel-Motaal

    2014-12-01

    Study results show that the maximum exerted straining actions in tunnel lining are directly proportional to the relative stiffness between tunnel and surrounding soil (lining thickness and soil shear modulus. Moreover, it is highly affected by the peak ground acceleration and the tunnel location (embedment depth. A comprehensive study is performed to show the effect of tunnel thickness and tunnel diameter on both the induced bending moment and lining deformation. In general, it is concluded that seismic analysis should be considered in regions subjected to peak ground acceleration greater than 0.15g.

  14. How Emotional Pictures Influence Visuospatial Binding in Short-Term Memory in Ageing and Alzheimer's Disease?

    Science.gov (United States)

    Borg, Celine; Leroy, Nicolas; Favre, Emilie; Laurent, Bernard; Thomas-Anterion, Catherine

    2011-01-01

    The present study examines the prediction that emotion can facilitate short-term memory. Nevertheless, emotion also recruits attention to process information, thereby disrupting short-term memory when tasks involve high attentional resources. In this way, we aimed to determine whether there is a differential influence of emotional information on…

  15. Puddles, Parties, and Professors : Linking Word Categorization to Neural Patterns of Visuospatial Coding

    NARCIS (Netherlands)

    Quadflieg, Susanne; Etzel, Joset A.; Gazzola, Valeria; Keysers, Christian; Schubert, Thomas W.; Waiter, Gordon D.; Macrae, C. Neil

    2011-01-01

    Behavioral evidence suggests that during word processing people spontaneously map object, valence, and power information to locations in vertical space. Specifically, whereas "overhead" (e. g., attic), positive (e. g., party), and powerful nouns (e. g., professor) are associated with "up," "underfoo

  16. How Emotional Pictures Influence Visuospatial Binding in Short-Term Memory in Ageing and Alzheimer's Disease?

    Science.gov (United States)

    Borg, Celine; Leroy, Nicolas; Favre, Emilie; Laurent, Bernard; Thomas-Anterion, Catherine

    2011-01-01

    The present study examines the prediction that emotion can facilitate short-term memory. Nevertheless, emotion also recruits attention to process information, thereby disrupting short-term memory when tasks involve high attentional resources. In this way, we aimed to determine whether there is a differential influence of emotional information on…

  17. Modality Specificity and Integration in Working Memory: Insights from Visuospatial Bootstrapping

    Science.gov (United States)

    Allen, Richard J.; Havelka, Jelena; Falcon, Thomas; Evans, Sally; Darling, Stephen

    2015-01-01

    The question of how meaningful associations between verbal and spatial information might be utilized to facilitate working memory performance is potentially highly instructive for models of memory function. The present study explored how separable processing capacities within specialized domains might each contribute to this, by examining the…

  18. Basic and Advanced Numerical Performances Relate to Mathematical Expertise but Are Fully Mediated by Visuospatial Skills

    Science.gov (United States)

    Sella, Francesco; Sader, Elie; Lolliot, Simon; Cohen Kadosh, Roi

    2016-01-01

    Recent studies have highlighted the potential role of basic numerical processing in the acquisition of numerical and mathematical competences. However, it is debated whether high-level numerical skills and mathematics depends specifically on basic numerical representations. In this study mathematicians and nonmathematicians performed a basic…

  19. Numerical analysis and field monitoring tests on shallow tunnels under weak surrounding rock

    Institute of Scientific and Technical Information of China (English)

    刘建华; 刘晓明; 张永杰; 肖庭

    2015-01-01

    The Jianpudong No. 4 tunnel is a shallow tunnel, which belongs to Shaoshan County scenic highway in Hunan province, China and whose surrounding rock is weak. According to its characteristics, the field monitoring tests and numerical analysis were done. The mechanical characteristics of shallow tunnels under weak surrounding rock and the stress−strain rule of surrounding rock and support were analyzed. The numerical analysis results show that the settlement caused by upper bench excavating accounts for 44% of the total settlement, and the settlement caused by tunnel upper bench supporting accounts for 56% of the total settlement. The maximum axial force of shotcrete lining is 177.2 kN, which locates in hance under the secondary lining. The maximum moment of shotcrete lining is 5.08 kN·m, which locates in the arch foot. The stress curve of steel arch has three obvious stages during the tunnel construction. The maximum axial force of steel arch is 297.4 kN, which locates in tunnel vault. The axial forces of steel arch are respectively 23.5 kN and−21.8 kN, which is influenced by eccentric compression of shallow tunnel and locates in hance. The results show that there is larger earth pressure in tunnel vault which is most unfavorable position of steel arch. Therefore, the advance support should be strengthened in tunnel vault during construction process.

  20. Influence of a polarizable surrounding on the electronically excited states of aggregated perylene materials.

    Science.gov (United States)

    Bellinger, Daniel; Settels, Volker; Liu, Wenlan; Fink, Reinhold F; Engels, Bernd

    2016-06-30

    To tune the efficiency of organic semiconductor devices it is important to understand limiting factors as trapping mechanisms for excitons or charges. An understanding of such mechanisms deserves an accurate description of the involved electronical states in the given environment. In this study, we investigate how a polarizable surrounding influences the relative positions of electronically excited states of dimers of different perylene dyes. Polarization effects are particularly interesting for these systems, because gas phase computations predict that the CT states lie slightly above the corresponding Frenkel states. A polarizable environment may change this energy order because CT states are thought to be more sensitive to a polarizable surrounding than Frenkel states. A first insight we got via a TD-HF approach in combination with a polarizable continuum model (PCM). These give limited insights because TD-HF overestimates excitation energies of CT states. However, SCS-CC2 approaches, which are sufficiently accurate, cannot easily be used in combination with continuum solvent models. Hence, we developed two approaches to combine gas phase SCS-CC2 results with solvent effects based on TD-HF computations. Their accuracies were finally checked via ADC(2)//COSMO computations. The results show that for perylene dyes a polarizable surrounding alone does not influence the energetic ordering of CT and Frenkel states. Variations in the energy order of the states only result from nuclear relaxation effects after the excitation process. © 2016 Wiley Periodicals, Inc.

  1. Maternal factors required for oocyte developmental competence in mice: transcriptome analysis of non-surrounded nucleolus (NSN) and surrounded nucleolus (SN) oocytes.

    Science.gov (United States)

    Ma, Jun-Yu; Li, Mo; Luo, Yi-Bo; Song, Shuhui; Tian, Dongmei; Yang, Jin; Zhang, Bing; Hou, Yi; Schatten, Heide; Liu, Zhonghua; Sun, Qing-Yuan

    2013-06-15

    During mouse antral follicle development, the oocyte chromatin gradually transforms from a less condensed state with no Hoechst-positive rim surrounding the nucleolus (NSN) to a fully condensed chromatin state with a Hoechst-positive rim surrounding the nucleolus (SN). Compared with SN oocytes, NSN oocytes display a higher gene transcription activity and a lower rate of meiosis resumption (G2/M transition), and they are mostly arrested at the two-cell stage after in vitro fertilization. To explore the differences between NSN and SN oocytes, and the maternal factors required for oocyte developmental competence, we compared the whole-transcriptome profiles between NSN and SN oocytes. First, we found that the NSN and SN oocytes were different in their metabolic pathways. In the phosphatidylinositol signaling pathway, the SN oocytes tend to produce diacylglycerol, whereas the NSN oocytes tend to produce phosphatidylinositol (3,4,5)-trisphosphate. For energy production, the SN oocytes and NSN oocytes differed in the gluconeogenesis and in the synthesis processes. Second, we also found that the key genes associated with oocyte meiosis and/or preimplantation embryo development were differently expressed in the NSN and SN oocytes. Our results illustrate that during the NSN-SN transition, the oocytes change their metabolic activities and accumulate maternal factors for further oocyte maturation and post-fertilization embryo development.

  2. More than 10 years after the first 'savior siblings': parental experiences surrounding preimplantation genetic diagnosis.

    Science.gov (United States)

    Zierhut, Heather; MacMillan, Margaret L; Wagner, John E; Bartels, Dianne M

    2013-10-01

    Preimplantation genetic diagnosis (PGD) to create a healthy donor for a sibling's hematopoetic stem cell transplantation for a child with Fanconi Anemia (FA) was first reported in 2001. Yet we know little about the experiences of parents who have encountered decision making surrounding PGD and human leukocyte antigen (HLA)-typing. The first aim of this study was to understand parents' awareness, perceptions and beliefs about reproductive decision-making including emotional, cognitive, moral dimensions as well as regret surrounding the use of this technology. The second aim was to describe the experiences and rationale of parents of children with a single gene disorder regarding the factors that influenced their decision making surrounding the use of natural pregnancy and/or PGD and HLA-typing. Parents from two national FA support networks in the US and Canada responded to an emailed survey about reproductive decision making and outcomes surrounding natural pregnancy and PGD and HLA-typing. Descriptive statistics and Pearson's Chi-Square tests were used to describe and compare data. Our results indicate that the most important factors in the PGD decision making process were the health of the child and cognitive appraisals followed by emotional responses and then moral judgments. A significant difference was noted in parents considering natural pregnancy before and after 2001 (p = 0.01). Unexpected findings were that less than 35 % of parents were offered PGD by any health care professional and only 70 % were aware PGD with HLA-typing was a reproductive option. Our research suggests that the option of PGD and HLA-typing may influence parents' reproductive decision making choices.

  3. Linking student performance in Massachusetts elementary schools with the "greenness" of school surroundings using remote sensing.

    Science.gov (United States)

    Wu, Chih-Da; McNeely, Eileen; Cedeño-Laurent, J G; Pan, Wen-Chi; Adamkiewicz, Gary; Dominici, Francesca; Lung, Shih-Chun Candice; Su, Huey-Jen; Spengler, John D

    2014-01-01

    Various studies have reported the physical and mental health benefits from exposure to "green" neighborhoods, such as proximity to neighborhoods with trees and vegetation. However, no studies have explicitly assessed the association between exposure to "green" surroundings and cognitive function in terms of student academic performance. This study investigated the association between the "greenness" of the area surrounding a Massachusetts public elementary school and the academic achievement of the school's student body based on standardized tests with an ecological setting. Researchers used the composite school-based performance scores generated by the Massachusetts Comprehensive Assessment System (MCAS) to measure the percentage of 3rd-grade students (the first year of standardized testing for 8-9 years-old children in public school), who scored "Above Proficient" (AP) in English and Mathematics tests (Note: Individual student scores are not publically available). The MCAS results are comparable year to year thanks to an equating process. Researchers included test results from 2006 through 2012 in 905 public schools and adjusted for differences between schools in the final analysis according to race, gender, English as a second language (proxy for ethnicity and language facility), parent income, student-teacher ratio, and school attendance. Surrounding greenness of each school was measured using satellite images converted into the Normalized Difference Vegetation Index (NDVI) in March, July and October of each year according to a 250-meter, 500-meter, 1,000-meter, and 2000-meter circular buffer around each school. Spatial Generalized Linear Mixed Models (GLMMs) estimated the impacts of surrounding greenness on school-based performance. Overall the study results supported a relationship between the "greenness" of the school area and the school-wide academic performance. Interestingly, the results showed a consistently positive significant association between the

  4. Interactions of the Infrared bubble N4 with the surroundings

    CERN Document Server

    Liu, Hong-Li; Wu, Yuefang; Yuan, Jing-Hua; Liu, Tie; Dubner, G; Paron, S; Ortega, M E; Molinari, Sergio; Huang, Maohai; Zavagno, Annie; Samal, Manash R; Huang, Ya-Fang; Zhang, Si-Ju

    2016-01-01

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with HII regions have been considered to be a good sample to investigate triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the HII region G11.898+0.747, analyzing its interaction with the surroundings and star formation histories therein, aiming at determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 $\\times10^{22}$ cm$^{-2}$, mean volume density of about 4.4 $\\times10^{4}$ cm$^{-3}$, and a mean mass of 320 $M_{\\odot}$. In addition, from PAH emission seen at 8 $\\mu$m, ...

  5. Radio observations of Supernova Remnants and the surrounding molecular gas

    CERN Document Server

    Dubner, G

    2011-01-01

    Supernova Remnants (SNRs) are believed to be the main source of Galactic cosmic rays (CR). The strong SNR shocks provide ideal acceleration sites for particles of at least 10^14 eV/nucleon. Radio continuum studies of SNRs carried out with good sensitivity and high angular resolution convey information about three main aspects of the SNRs: morphology, polarization and spectrum. Based on this information it is possible to localize sites of higher compression and particle acceleration as well as the orientation and degree of order of the magnetic fields, and in some cases even its intensity. All this information, when complemented with the study of the distribution and kinematics of the surrounding interstellar gas, results in a very useful dataset to investigate the role of SNRs as cosmic ray accelerators. In this presentation, I analyze the radio observations of SNRs and surrounding molecular clouds, showing the contribution of these studies to the understanding of the role of SNRs as factories of CRs.

  6. On the environment surrounding close-in exoplanets

    CERN Document Server

    Vidotto, A A; Jardine, M; Moutou, C; Donati, J -F

    2015-01-01

    Exoplanets in extremely close-in orbits are immersed in a local interplanetary medium (i.e., the stellar wind) much denser than the local conditions encountered around the solar system planets. The environment surrounding these exoplanets also differs in terms of dynamics (slower stellar winds, but higher Keplerian velocities) and ambient magnetic fields (likely higher for host stars more active than the Sun). Here, we quantitatively investigate the nature of the interplanetary media surrounding the hot Jupiters HD46375b, HD73256b, HD102195b, HD130322b, HD179949b. We simulate the three-dimensional winds of their host stars, in which we directly incorporate their observed surface magnetic fields. With that, we derive mass-loss rates (1.9 to 8.0 $\\times 10^{-13} M_{\\odot}$/yr) and the wind properties at the position of the hot-Jupiters' orbits (temperature, velocity, magnetic field intensity and pressure). We show that these exoplanets' orbits are super-magnetosonic, indicating that bow shocks are formed surrou...

  7. Earlier visual N1 latencies in expert video-game players: a temporal basis of enhanced visuospatial performance?

    Directory of Open Access Journals (Sweden)

    Andrew J Latham

    Full Text Available Increasing behavioural evidence suggests that expert video game players (VGPs show enhanced visual attention and visuospatial abilities, but what underlies these enhancements remains unclear. We administered the Poffenberger paradigm with concurrent electroencephalogram (EEG recording to assess occipital N1 latencies and interhemispheric transfer time (IHTT in expert VGPs. Participants comprised 15 right-handed male expert VGPs and 16 non-VGP controls matched for age, handedness, IQ and years of education. Expert VGPs began playing before age 10, had a minimum 8 years experience, and maintained playtime of at least 20 hours per week over the last 6 months. Non-VGPs had little-to-no game play experience (maximum 1.5 years. Participants responded to checkerboard stimuli presented to the left and right visual fields while 128-channel EEG was recorded. Expert VGPs responded significantly more quickly than non-VGPs. Expert VGPs also had significantly earlier occipital N1s in direct visual pathways (the hemisphere contralateral to the visual field in which the stimulus was presented. IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. No significant between-group differences in electrophysiological estimates of IHTT were found. Shorter N1 latencies may enable expert VGPs to discriminate attended visual stimuli significantly earlier than non-VGPs and contribute to faster responding in visual tasks. As successful video-game play requires precise, time pressured, bimanual motor movements in response to complex visual stimuli, which in this sample began during early childhood, these differences may reflect the experience and training involved during the development of video-game expertise, but training studies are needed to test this prediction.

  8. Earlier visual N1 latencies in expert video-game players: a temporal basis of enhanced visuospatial performance?

    Science.gov (United States)

    Latham, Andrew J; Patston, Lucy L M; Westermann, Christine; Kirk, Ian J; Tippett, Lynette J

    2013-01-01

    Increasing behavioural evidence suggests that expert video game players (VGPs) show enhanced visual attention and visuospatial abilities, but what underlies these enhancements remains unclear. We administered the Poffenberger paradigm with concurrent electroencephalogram (EEG) recording to assess occipital N1 latencies and interhemispheric transfer time (IHTT) in expert VGPs. Participants comprised 15 right-handed male expert VGPs and 16 non-VGP controls matched for age, handedness, IQ and years of education. Expert VGPs began playing before age 10, had a minimum 8 years experience, and maintained playtime of at least 20 hours per week over the last 6 months. Non-VGPs had little-to-no game play experience (maximum 1.5 years). Participants responded to checkerboard stimuli presented to the left and right visual fields while 128-channel EEG was recorded. Expert VGPs responded significantly more quickly than non-VGPs. Expert VGPs also had significantly earlier occipital N1s in direct visual pathways (the hemisphere contralateral to the visual field in which the stimulus was presented). IHTT was calculated by comparing the latencies of occipital N1 components between hemispheres. No significant between-group differences in electrophysiological estimates of IHTT were found. Shorter N1 latencies may enable expert VGPs to discriminate attended visual stimuli significantly earlier than non-VGPs and contribute to faster responding in visual tasks. As successful video-game play requires precise, time pressured, bimanual motor movements in response to complex visual stimuli, which in this sample began during early childhood, these differences may reflect the experience and training involved during the development of video-game expertise, but training studies are needed to test this prediction.

  9. Impairment of visuospatial/visuoconstructional skills in multiple sclerosis patients: the correlation with regional lesion load and subcortical atrophy.

    Science.gov (United States)

    Marasescu, R; Cerezo Garcia, M; Aladro Benito, Y

    2016-04-01

    About 20% to 26% of patients with multiple sclerosis (MS) show alterations in visuospatial/visuoconstructive (VS-VC) skills even though temporo-parieto-occipital impairment is a frequent finding in magnetic resonance imaging. No studies have specifically analysed the relationship between these functions and lesion volume (LV) in these specific brain areas. To evaluate the relationship between VS-VC impairment and magnetic resonance imaging temporo-parieto-occipital LV with subcortical atrophy in patients with MS. Of 100 MS patients undergoing a routine neuropsychological evaluation, 21 were selected because they displayed VS-VC impairments in the following tests: Incomplete picture, Block design (WAIS-III), and Rey-Osterrieth complex figure test. We also selected 13 MS patients without cognitive impairment (control group). Regional LV was measured in FLAIR and T1-weighted images using a semiautomated method; subcortical atrophy was measured by bicaudate ratio and third ventricle width. Partial correlations (controlling for age and years of school) and linear regression analysis were employed to analyse correlations between magnetic resonance imaging parameters and cognitive performance. All measures of LV and brain atrophy were significantly higher in patients with cognitive impairment. Regional LV, bicaudate ratio, and third ventricle width are significantly and inversely correlated with cognitive performance; the strongest correlation was between third ventricle width and VC performance (Block design: P=.001; Rey-Osterrieth complex figure: P<.000). In the multivariate analysis, third ventricle width only had a significant effect on performance of VC tasks (Block design: P=.000; Rey-Osterrieth complex figure: P=.000), and regional FLAIR VL was linked to the VS task (Incomplete picture; P=.002). Measures of subcortical atrophy explain the variations in performance on visuocostructive tasks, and regional FLAIR VL measures are linked to VS tasks. Copyright © 2015

  10. Cognitive abilities in children with specific language impairment: consideration of visuo-spatial skills

    OpenAIRE

    Hick, R. F.; Botting, N.; Conti-Ramsden, G.

    2005-01-01

    Background: The study is concerned with the cognitive abilities of children with specific language impairment (SLI). Previous research has indicated that children with SLI demonstrate difficulties with certain cognitive tasks despite normal non‐verbal IQ scores. It has been suggested that a general processing limitation might account for the pattern of language and cognitive difficulties seen in children with SLI. The performances on a visuo‐spatial short‐term memory task and a visuo‐spatial ...

  11. Hunting for right and left parietal hot spots using single-pulse TMS: modulation of visuospatial perception during line bisection judgment in the healthy brain.

    Science.gov (United States)

    Salatino, Adriana; Poncini, Marisa; George, Mark S; Ricci, Raffaella

    2014-01-01

    A series of studies have consistently reproduced left neglect-like bias on line length estimation tasks in healthy participants by applying transcranial magnetic stimulation (TMS) over the right posterior parietal cortex (PPC), while no significant changes have been reported when stimulating the left PPC. However, a notable inter-individual variability in the right parietal site where TMS modulates visuospatial perception can be observed, and no general agreement exists on how to identify the optimal parietal site of stimulation. In the present study, we propose a new site-finding TMS protocol to easily identify the optimum parietal location, or "hot spot," where TMS may modulate visuospatial perception on a line length estimation task (the Landmark task). Single-pulse TMS at 115% of motor threshold was applied 150 ms after the visual stimulus onset over nine different sites of a 3 cm × 3 cm grid, centred over right or left PPC (P4 and P3 according to the 10-20 EEG system, respectively) in eight healthy participants. Stimulation of right PPC induced a significant left neglect-like bias, when the coil was applied over the most posterior and dorso-posterior sites. Unexpectedly, TMS over left PPC also produced left neglect-like bias. However, in this case significant effects were found when targeting the most anterior and dorso-anterior portions of the grid. These results are discussed in relation to recent findings on neural networks underlying spatial cognition. The hunting protocol we propose might offer an economical and easy-to-use tool to functionally identify the optimal parietal site where TMS can modulate visuospatial perception, in healthy subjects and possibly in post-stroke patients undergoing repetitive transcranial magnetic stimulation treatment.

  12. Study on visualization simulation of temperature distributions in surrounding rock of tunnels in a deep mine

    Institute of Scientific and Technical Information of China (English)

    SUN Pei-de

    2006-01-01

    Based on the mathematical model for rock temperature distribution in a geothermal field, the properties of rock temperature distribution in geothermal field for four kinds of surrounding rock cross-sections of tunnels in a deep mine were simulated by using finite element method. It is shown that the relationship for rock temperature distribution varied with the geothermal parameters, time and space. Namely, 2-dimensional time-dependent isograms clearly showed the process for rock temperature variation and distribution in a geothermal field which has been redisplayed with visualization numerical simulation.

  13. Puddles, parties, and professors: linking word categorization to neural patterns of visuospatial coding.

    Science.gov (United States)

    Quadflieg, Susanne; Etzel, Joset A; Gazzola, Valeria; Keysers, Christian; Schubert, Thomas W; Waiter, Gordon D; Macrae, C Neil

    2011-10-01

    Behavioral evidence suggests that during word processing people spontaneously map object, valence, and power information to locations in vertical space. Specifically, whereas "overhead" (e.g., attic), positive (e.g., party), and powerful nouns (e.g., professor) are associated with "up," "underfoot" (e.g., carpet), negative (e.g., accident), and powerless nouns (e.g., assistant) are associated with "down." What has yet to be elucidated, however, is the precise nature of these effects. To explore this issue, an fMRI experiment was undertaken, during which participants were required to categorize the position in which geometrical shapes appeared on a computer screen (i.e., upper or lower part of the display). In addition, they also judged a series of words with regard to location (i.e., up vs. down), valence (i.e., good vs. bad), and power (i.e., powerful vs. powerless). Using multivoxel pattern analysis, it was found that classifiers that successfully distinguished between the positions of shapes in subregions of the inferior parietal lobe also provided discriminatory information to separate location and valence, but not power word judgments. Correlational analyses further revealed that, for location words, pattern transfer was more successful the stronger was participants' propensity to use visual imagery. These findings indicate that visual coding and conceptual processing can elicit common representations of verticality but that divergent mechanisms may support the reported effects.

  14. A foundation for savantism? Visuo-spatial synaesthetes present with cognitive benefits.

    Science.gov (United States)

    Simner, Julia; Mayo, Neil; Spiller, Mary-Jane

    2009-01-01

    Individuals with 'time-space' synaesthesia have conscious awareness of mappings between time and space (e.g., they may see months arranged in an ellipse, or years as columns or spirals). These mappings exist in the 3D space around the body or in a virtual space within the mind's eye. Our study shows that these extra-ordinary mappings derive from, or give rise to, superior abilities in the two domains linked by this cross-modal phenomenon (i.e., abilities relating to time, and visualised space). We tested ten time-space synaesthetes with a battery of temporal and visual/spatial tests. Our temporal battery (the Edinburgh [Public and Autobiographical] Events Battery - EEB) assessed both autobiographical and non-autobiographical memory for events. Our visual/spatial tests assessed the ability to manipulate real or imagined objects in 3D space (the Three Dimensional Constructional Praxis test; Visual Object and Space Perception Battery, University of Southern California Mental Rotation Test) as well as assessing visual memory recall (Visual Patterns Test - VPT). Synaesthetes' performance was superior to the control population in every assessment, but was not superior in tasks that do not draw upon abilities related to their mental calendars. Our paper discusses the implications of this temporal-spatial advantage as it relates to normal processing, synaesthetic processing, and to the savant-like condition of hyperthymestic syndrome (Parker et al., 2006).

  15. The effect of functional hearing loss and age on long- and short-term visuospatial memory: evidence from the UK biobank resource

    OpenAIRE

    Jerker eRönnberg; Staffan eHygge; Gitte eKeidser; Mary eRudner

    2014-01-01

    The UK Biobank offers cross-sectional epidemiological data collected on > 500 000 individuals in the UK between 40 and 70 years of age. Using the UK Biobank data, the aim of this study was to investigate the effects of functional hearing loss and hearing aid usage on visuospatial memory function. This selection of variables resulted in a sub-sample of 138 098 participants after discarding extreme values. A digit triplets functional hearing test was used to divide the participants into three g...

  16. Reduced Crowding and Poor Contour Detection in Schizophrenia Are Consistent with Weak Surround Inhibition

    Science.gov (United States)

    Robol, Valentina; Tibber, Marc S.; Anderson, Elaine J.; Bobin, Tracy; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Background Detection of visual contours (strings of small oriented elements) is markedly poor in schizophrenia. This has previously been attributed to an inability to group local information across space into a global percept. Here, we show that this failure actually originates from a combination of poor encoding of local orientation and abnormal processing of visual context. Methods We measured the ability of observers with schizophrenia to localise contours embedded in backgrounds of differently oriented elements (either randomly oriented, near-parallel or near-perpendicular to the contour). In addition, we measured patients’ ability to process local orientation information (i.e., report the orientation of an individual element) for both isolated and crowded elements (i.e., presented with nearby distractors). Results While patients are poor at detecting contours amongst randomly oriented elements, they are proportionally less disrupted (compared to unaffected controls) when contour and surrounding elements have similar orientations (near-parallel condition). In addition, patients are poor at reporting the orientation of an individual element but, again, are less prone to interference from nearby distractors, a phenomenon known as visual crowding. Conclusions We suggest that patients’ poor performance at contour perception arises not as a consequence of an “integration deficit” but from a combination of reduced sensitivity to local orientation and abnormalities in contextual processing. We propose that this is a consequence of abnormal gain control, a phenomenon that has been implicated in orientation-selectivity as well as surround suppression. PMID:23585865

  17. Reduced crowding and poor contour detection in schizophrenia are consistent with weak surround inhibition.

    Directory of Open Access Journals (Sweden)

    Valentina Robol

    Full Text Available BACKGROUND: Detection of visual contours (strings of small oriented elements is markedly poor in schizophrenia. This has previously been attributed to an inability to group local information across space into a global percept. Here, we show that this failure actually originates from a combination of poor encoding of local orientation and abnormal processing of visual context. METHODS: We measured the ability of observers with schizophrenia to localise contours embedded in backgrounds of differently oriented elements (either randomly oriented, near-parallel or near-perpendicular to the contour. In addition, we measured patients' ability to process local orientation information (i.e., report the orientation of an individual element for both isolated and crowded elements (i.e., presented with nearby distractors. RESULTS: While patients are poor at detecting contours amongst randomly oriented elements, they are proportionally less disrupted (compared to unaffected controls when contour and surrounding elements have similar orientations (near-parallel condition. In addition, patients are poor at reporting the orientation of an individual element but, again, are less prone to interference from nearby distractors, a phenomenon known as visual crowding. CONCLUSIONS: We suggest that patients' poor performance at contour perception arises not as a consequence of an "integration deficit" but from a combination of reduced sensitivity to local orientation and abnormalities in contextual processing. We propose that this is a consequence of abnormal gain control, a phenomenon that has been implicated in orientation-selectivity as well as surround suppression.

  18. Avaliação da memória de trabalho verbal e visuoespacial no comprometimento cognitivo leve e na doença de Alzheimer [Assessment of verbal and visuospatial working memory in mild cognitive impairment and Alzheimer's dementia

    NARCIS (Netherlands)

    Kessels, R.P.C.; Overbeek, A.; Bouman, Z.

    2015-01-01

    In addition to episodic memory impairment, working memory may also be compromised in mild cognitive impairment (MCI) or Alzheimer's dementia (AD), but standard verbal and visuospatial span tasks do not always detect impairments.Objective:To examine whether more complex verbal and visuospatial workin

  19. Wave rectification in plasma sheaths surrounding electric field antennas

    Science.gov (United States)

    Boehm, M. H.; Carlson, C. W.; Mcfadden, J. P.; Clemmons, J. H.; Ergun, R. E.; Mozer, F. S.

    1994-01-01

    Combined measurements of Langmuir or broadband whistler wave intensity and lower-frequency electric field waveforms, all at 10-microsecond time resolution, were made on several recent sounding rockets in the auroral ionosphere. It is found that Langmuir and whistler waves are partically rectified in the plasma sheaths surrounding the payload and the spheres used as antennas. This sheath rectification occurs whenever the high frequency (HF) potential across the sheath becomes of the same order as the electron temperature or higher, for wave frequencies near or above the ion plasma frequency. This rectification can introduce false low-frequency waves into measurements of electric field spectra when strong high-frequency waves are present. Second harmonic signals are also generated, although at much lower levels. The effect occurs in many different plasma conditions, primarily producing false waves at frequencies that are low enough for the antenna coupling to the plasma to be resistive.

  20. The nature of plerions surrounding soft gamma-ray repeaters

    CERN Document Server

    Harding, A K

    1995-01-01

    Compact steady sources of X-ray emission have been detected at the positions of at least two soft gamma-ray repeaters (SGRs). These sources have been interpreted as synchrotron nebulae powered by the neutron star that is causing the bursts. We explore a plerion model for the sources surrounding SGRs where the steady observed emission is powered by the SGR bursts rather than by the spin-down of a pulsar. In this case there is no limit on the neutron star magnetic field. We find that the synchrotron lifetime of the particles injected into the plerion around SGR1806-20 is long enough to smear out nebular emission from individual bursts. Transient nebular emission would therefore not be detected following an SGR burst. The combined radio emission from multiple burst injections is expected to have a steeper spectrum than that of a typical plerion.

  1. Casimir Effect in the Kerr Spacetime Surrounded by Quintessence

    CERN Document Server

    Bezerra, V B; Freitas, L F F; Muniz, C R

    2016-01-01

    We calculate the Casimir energy of a massless scalar field in a cavity formed by nearby parallel plates orbiting a rotating spherical body surrounded by quintessence, investigating the influence of the gravitational field on that energy, at zero temperature. This influence includes the effects due to the spacetime dragging caused by the source rotation as well as those ones due to the quintessence. We show that the energy depends on all the involved parameters, as source mass, angular momentum and quintessence state parameter, for any radial coordinate and polar angle. We show that at the north pole the Casimir energy is not influenced by the quintessential matter. At the equatorial plane, when the quintessence is canceled, the result obtained in the literature is recovered. Finally, constraints in the quintessence parameters are obtained from the uncertainty in the current measurements of Casimir effect.

  2. Ozone bioindication in Barcelona and surrounding area of Catalonia

    Energy Technology Data Exchange (ETDEWEB)

    Ribas, A.; Penuelas, J. [Univ. Autonoma de Barcelona, Barcelona (Spain). Ecophysiology Unit of CSIC

    2002-07-01

    A field study was conducted from July to September 2000 to assess ozone (O{sub 3}) phytotoxicity in Barcelona and surrounding areas of Catalonia (NE Spain) by using tobacco plants Bel-W3 and Populus nigra 'Brandaris' as bioindicators. The study was conducted simultaneously at eight sites where ozone concentrations and meteorological variables were continuously monitored. The ozone levels correlated well with ozone injury on the Bel-W3 cultivar, especially at stations established in the urban area of Barcelona, and in the first months of summer. In the second half of summer plants showed a decreasing efficiency in its biomonitoring capacity. The behaviour of Populus as bioindicator or biomonitor was less satisfactory. For both species it is necessary to improve cultivation conditions since water deficits seem to play an important role in bioindication in the Mediterranean region. (orig.)

  3. Physical Coupling of Kazarian Galaxies with Surrounding Galaxies

    Science.gov (United States)

    Kazarian, M. A.; Martirosian, J. R.

    2003-04-01

    Results from a statistical study of Kazarian galaxies and the objects surrounding them are presented. It is shown that: (1) the sample of Kazarian galaxies up to 16m.0 is complete. (2) Roughly 35.7% of the Kazarian galaxies are members of clusters, 14.0% of groups, and 13.6% of binary systems, while 36.7% are single galaxies. (3) Of the 580 Kazarian galaxies, roughly 61.2% are infrared, 8.8% radio, and 2.8% x-ray sources. (4) The relative numbers of Kazarian galaxies for complete samples of I, R, and X in the different groups are systematically higher than the corresponding numbers for samples of all Kazarian galaxies.

  4. On radial oscillations in viscous accretion discs surrounding neutron stars

    Science.gov (United States)

    Chen, Xingming; Taam, Ronald E.

    1992-01-01

    Radial oscillations resulting from axisymmetric perturbations in viscous accretion disks surrounding neutron stars in X-ray binary systems have been investigated. Within the framework of the alpha-viscosity model a series of hydrodynamic calculations demonstrates that the oscillations are global for alpha of about 1. On the other hand, for alpha of 0.4 or less, the oscillations are local and confined to the disk boundaries. If viscous stresses acting in the radial direction are included, however, it is found that the disk can be stabilized. The application of such instabilities in accretion disks, without reference to the boundary layer region between the neutron star (or magnetosphere) and the inner edge of the disk, to the phenomenology of quasi-periodic oscillations is brought into question.

  5. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O`Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-09-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  6. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O' Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-01-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  7. Rotation of the Warm Molecular Gas Surrounding Ultracompact HII Regions

    CERN Document Server

    Klaassen, P D; Keto, E R; Zhang, Q

    2009-01-01

    We present molecular line and 1.4 mm continuum observations towards five massive star forming regions at arcsecond resolution using the Submillimeter Array (SMA). We find that the warm molecular gas surrounding each HII region (as traced by SO_2 and OCS) appears to be undergoing bulk rotation. From the molecular line emission and thermal component of the continuum emission, we independently derived gas masses for each region which are consistent with each other. From the free-free component of the continuum emission we estimate the minimum stellar mass required to power the HII region and find that this mass, when added to the derived gas mass, is a significant fraction of the dynamical mass for that region.

  8. A 500 Parsec Halo Surrounding the Galactic Globular NGC 1851

    CERN Document Server

    Olszewski, Edward W; Knezek, Patricia; Subramaniam, Annapurni; de Boer, Thomas; Seitzer, Patrick

    2009-01-01

    Using imaging that shows four magnitudes of main sequence stars, we have discovered that the Galactic globular cluster NGC 1851 is surrounded by a halo that is visible from the tidal radius of 700 arcsec (41 pc) to more than 4500 arcsec (>250 pc). This halo is symmetric and falls in density as a power law of $r^{-1.24}$. It contains approximately 0.1% of the dynamical mass of NGC 1851. There is no evidence for tidal tails. Current models of globular cluster evolution do not explain this feature, although simulations of tidal influences on dwarf spheroidal galaxies qualitatively mimic these results. Given the state of published models it is not possible to decide between creation of this halo from isolated cluster evaporation, or from tidal or disk shocking, or from destruction of a dwarf galaxy in which this object may have once been embedded.

  9. Thermodynamic stability of black holes surrounded by quintessence

    CERN Document Server

    Ma, Meng-Sen; Ma, Ya-Qin

    2016-01-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence $\\omega_q$ is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic quantities also satisfy Smarr-like formulae. It is found that the uncharged BHQ is always thermodynamically unstable due to negative heat capacity, while for the charged BHQ there are phase transitions of the second order. We also show that there is a great deal of difference on the thermodynamic properties and critical behaviors of BHQ between the two ways we employed.

  10. Thermodynamic stability of black holes surrounded by quintessence

    Science.gov (United States)

    Ma, Meng-Sen; Zhao, Ren; Ma, Ya-Qin

    2017-06-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence ω _q is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic quantities also satisfy Smarr-like formulae. It is found that the uncharged BHQ is always thermodynamically unstable due to negative heat capacity, while for the charged BHQ there are phase transitions of the second order. We also show that there are several differences on the thermodynamic properties and critical behaviors of BHQ between the two ways we employed.

  11. Impact-Generated Dust Clouds Surrounding the Galilean Moons

    CERN Document Server

    Krüger, H; Grün, E; Kr\\"uger, Harald~; Krivov, Alexander V.; Gr\\"un, Eberhard

    2003-01-01

    Tenuous dust clouds of Jupiter's Galilean moons Io, Europa, Ganymede and Callisto have been detected with the in-situ dust detector on board the Galileo spacecraft. The majority of the dust particles have been sensed at altitudes below five radii of these lunar-sized satellites. We identify the particles in the dust clouds surrounding the moons by their impact direction, impact velocity, and mass distribution. Average particle sizes are 0.5 to $\\rm 1 \\mu m$, just above the detector threshold, indicating a size distribution with decreasing numbers towards bigger particles. Our results imply that the particles have been kicked up by hypervelocity impacts of micrometeoroids onto the satellites' surfaces. The measured radial dust density profiles are consistent with predictions by dynamical modeling for satellite ejecta produced by interplanetary impactors (Krivov et al., PSS, 2003, 51, 251--269), assuming yield, mass and velocity distributions of the ejecta from laboratory measurements. The dust clouds of the th...

  12. Visuo-spatial memory tests in right temporal lobe epilepsy foci: clinical validity.

    Science.gov (United States)

    Wisniewski, Ilona; Wendling, Anne-Sophie; Manning, Lilianne; Steinhoff, Bernhard J

    2012-03-01

    To examine the appropriateness of visual memory tests as an identification method for right mesial temporal lobe dysfunctions in an epilepsy patient group and to study the relationship and possible overlap with non-memory cognitive domains and demographic variables. Eighty preoperative candidates with mesial temporal lobe epilepsy (TLE) were examined using the "Corsi Block-Tapping Test", "Diagnosticum für Cerebralschädigung" (DCS), the path subtest of the "Verbaler und Visueller Merkfähigkeitstest" (VVM), and the Rey-Osterrieth Complex Figure Test (ROCF). Factorial analyses were performed on raw scores to determine the effect of epilepsy-related variables, interictal epileptiform discharges (IEDs) and presence of cortical dysgenesis, on visual and verbal memory parameters. Sensitivity, specificity and Receiver Operating Characteristic (ROC) curves were calculated based on normative data. Furthermore, Spearman correlations between memory and non-memory cognitive tasks were performed. The scores for test sensitivity and specificity and the ROC curves illustrate the tests' poor capacity to lateralize the functional deficit zone even when epilepsy-related factors, such as cortical dysgenesis or presence of contralateral IEDs were controlled. Significant correlations were found between the visual memory measures and nonverbal reasoning, processing speed, attentional flexibility, and visual planning. These neuropsychological tests are not sensitive enough to lateralize the epileptogenic focus in temporal lobe epilepsy patients since in addition to learning and consolidation processes, they measure additional cognitive domains. These results have implications for clinical neuropsychologists, in terms of test choice and the interpretation in the context of presurgical diagnostics. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. Serial position markers in space: visuospatial priming of serial order working memory retrieval.

    Directory of Open Access Journals (Sweden)

    Maya De Belder

    Full Text Available Most general theories on serial order working memory (WM assume the existence of position markers that are bound to the to-be-remembered items to keep track of the serial order. So far, the exact cognitive/neural characteristics of these markers have remained largely underspecified, while direct empirical evidence for their existence is mostly lacking. In the current study we demonstrate that retrieval from verbal serial order WM can be facilitated or hindered by spatial cuing: begin elements of a verbal WM sequence are retrieved faster after cuing the left side of space, while end elements are retrieved faster after cuing the right side of space. In direct complement to our previous work--where we showed the reversed impact of WM retrieval on spatial processing--we argue that the current findings provide us with a crucial piece of evidence suggesting a direct and functional involvement of space in verbal serial order WM. We outline the idea that serial order in verbal WM is coded within a spatial coordinate system with spatial attention being involved when searching through WM, and we discuss how this account can explain several hallmark observations related to serial order WM.

  14. Difference rather than delay in development of elementary visuomotor processes in children born preterm without Celebral Palsy : A quasi-longitudinal study

    NARCIS (Netherlands)

    Van Braeckel, K.N.J.A.; Butcher, P.R.; Geuze, R.H.; van Duijn, M.A.J.; Bos, Arie; Bouma, Anke

    Follow-up studies of preterm children without serious neonatal medical complications have consistently found poor visuomotor and visuospatial skills. In the first round of current follow-up study, we found a deficit in elementary visuomotor processes in preterm children without Cerebral Palsy (CP).

  15. Emotionally negative stimuli can overcome attentional deficits in patients with visuo-spatial hemineglect.

    Science.gov (United States)

    Grabowska, A; Marchewka, A; Seniów, J; Polanowska, K; Jednoróg, K; Królicki, L; Kossut, M; Członkowska, A

    2011-10-01

    Left unilateral spatial neglect resulting from right brain damage is characterized by loss of awareness for stimuli in the contralesional side of space, despite intact visual pathways. We examined using fMRI whether patients with neglect are more likely to consciously detect in the neglected hemifield, emotionally negative complex scenes rather than visually similar neutral pictures and if so, what neural mechanisms mediate this effect. Photographs of emotional and neutral scenes taken from the IAPS were presented in a divided visual field paradigm. As expected, the detection rate for emotional stimuli presented in the neglected field was higher than for neutral ones. Successful detection of emotional scenes as opposed to neutral stimuli in the left visual field (LVF) produced activations in the parahippocampal and anterior cingulate areas in the right hemisphere. Detection of emotional stimuli presented in the intact right visual field (RVF) activated a distributed network of structures in the left hemisphere, including anterior and posterior cingulate cortex, insula, as well as visual striate and extrastriate areas. LVF-RVF contrasts for emotional stimuli revealed activations in right and left attention related prefrontal areas whereas RVF-LVF comparison showed activations in the posterior cingulate and extrastriate visual cortex in the left hemisphere. An additional analysis contrasting detected vs. undetected emotional LVF stimuli showed involvement of left anterior cingulate, right frontal and extrastriate areas. We hypothesize that beneficial role of emotion in overcoming neglect is achieved by activation of frontal and limbic lobe networks, which provide a privileged access of emotional stimuli to attention by top-down modulation of processing in the higher-order extrastriate visual areas. Our results point to the importance of top-down regulatory role of the frontal attentional systems, which might enhance visual activations and lead to greater salience of

  16. Identifying developmental coordination disorder: MOQ-T validity as a fast screening instrument based on teachers' ratings and its relationship with praxic and visuospatial working memory deficits.

    Science.gov (United States)

    Giofrè, David; Cornoldi, Cesare; Schoemaker, Marina M

    2014-12-01

    The present study was devoted to test the validity of the Italian adaptation of the Motor Observation Questionnaire for Teachers (MOQ-T, Schoemaker, Flapper, Reinders-Messelink, & De Kloet, 2008) as a fast screening instrument, based on teachers' ratings, for detecting developmental coordination disorders symptoms and to study its relationship with praxic and visuospatial working memory deficits. In a first study on a large sample of children, we assessed the reliability and structure of the Italian adaptation of the MOQ-T. Results showed a good reliability of the questionnaire and a hierarchical structure with two first-order factors (reflecting motor and handwriting skills), which are influenced by a second-order factor (general motor function) at the top. In a second study, we looked at the external validity of the MOQ-T and found that children with symptoms of Developmental Coordination Disorder (children with high scores on the MOQ-T) also had difficulty reproducing gestures, either imitating others or in response to verbal prompts. Our results also showed that children with high MOQ-T scores had visuospatial WM impairments. The theoretical and clinical implications of these findings are discussed.

  17. The structural feature surrounding glycated lysine residues in human hemoglobin.

    Science.gov (United States)

    Ito, Shigenori; Nakahari, Takashi; Yamamoto, Daisuke

    2011-06-01

    Complications derived from diabetes mellitus are caused by nonenzymatic protein glycation at the specific sites. LC/MS/MS was performed for the identification of the tryptic peptides of glycated hemoglobins using glyceraldehyde. After the identification of the glycation or non-glycation site, computer analysis of the structure surrounding the sites was carried out using PDB data (1BZ0). Five glycated lysine residues (Lys-16(α), -56(α), -8(β), -82(β), and -144(β)) and four non-glycated lysine residues (Lys-7(α), -40(α), -99(α), and -132(β)) were identified. The non-glycated lysine residues, Lys-7(α), -40(α), and -132(β), are most likely to form electrostatic interactions with the β carboxyl group of Asp-74(α), C-terminal His-146(β), and Glu-7(β) by virtue of their proximity, which is 2.67-2.91 Å (N-O). Additionally, there are histidine residues within 4.55-7.38 Å (N-N) around eight sites except for Lys-7(α). We conclude that the following factors seem to be necessary for glycation of lysine residues: (i) the apparent absence of aspartate or glutamate residues to inhibit the glycation reaction by forming an electrostatic interaction, (ii) the presence of histidine residues for acid-base catalysis of the Amadori rearrangement, and (iii) the presence of an amino acid residue capable of stabilizing a phosphate during proton transfer.

  18. Dilemmas surrounding passive euthanasia--a Malaysian perspective.

    Science.gov (United States)

    Talib, Norchaya

    2005-09-01

    In western societies where the principle of autonomy is jealously guarded, perhaps active euthanasia is more often the focus of public concern and debates rather than any other forms of euthanasia. However due to the advance in technology and its corresponding ability in prolonging life, in Malaysia passive euthanasia presents more of a dilemma. For those concerned and involved with end of life decision-making, it is generally agreed that this is an area fraught with not only medical but legal and ethical issues. In Malaysia where the society is not homogenous but is multi-cultural and multi-religious, in addition to medical, legal and ethical issues, religious principles and cultural norms further impact and play significant roles in end of life decision-making. This paper seeks to identify the issues surrounding the practice of passive euthanasia in Malaysia. It will be shown that despite applicable legal provisions, current practice of the medical profession combined with religious and cultural values together affect decision-making which involves the withholding and/or withdrawing of life-saving treatment.

  19. Zonal disintegration phenomenon in rock mass surrounding deep tunnels

    Institute of Scientific and Technical Information of China (English)

    WU Hao; FANG Qin; GUO Zhi-kun

    2008-01-01

    Zonal disintegration is a typical static phenomenon of deep rock masses. It has been defined as alternating regions of fractured and relatively intact rock mass that appear around or in front of the working stope during excavation of a deep tunnel. Zonal disintegration phenomenon was successfully demonstrated in the laboratory with 3D tests on analogous gypsum models, two circular cracked zones were observed in the test. The linear Mohr-Coulomb yield criterion was used with a constitutive model that showed linear softening and ideal residual plastic to analyze the elasto-plastic field of the enclosing rock mass around a deep tunnel. The results show that tunneling causes a maximum stress zone to appear between an elastic and plastic zone in the surrounding rock. The zonal disintegration phenomenon is analyzed by considering the stress-strain state of the rock mass in the vicinity of the maximum stress zone. Creep instability failure of the rock due to the development of the plastic zone, and transfer of the maximum stress zone into the rock mass, are the cause of zonal disintegration. An analytical criterion for the critical depth at which zonal disintegration can occur is derived. This depth depends mainly on the character and stress concentration coefficient of the rock mass.

  20. Beliefs and practices surrounding postpartum period among Myanmar women.

    Science.gov (United States)

    Sein, Kyi Kyi

    2013-11-01

    to examine the postpartum beliefs and practices among young women (15-24 years) both quantitative and qualitative approaches were used: a cross-sectional comparative study using a semi-structured questionnaire and focus group discussions (FGDs). Kyimyindaing Township in the western district of Yangon, Myanmar. young women (15-24 years) who had experience of at least one live birth were included. A total of 196 women for a quantitative survey and 31 women for FGDs were recruited. postpartum beliefs and practices at the last childbirth were explored by a pretested semi-structured questionnaire and four FGDs (two in urban and two in rural areas). The survey questionnaire covered socio-demographic data, food and behavioural restrictions and observances during the last postpartum period and underlying reasons for those practices. Majority of participants followed the traditional postpartum practices regardless of the area of residence and education level. Notion of 'dirty lochia' was identified. traditional beliefs and practices surrounding post partum were highly prevalent among young women. Variation in degree and duration of adherence to postpartum taboos was noted. These beliefs and practices were imparted and perpetuated by women's close social network. the findings point out the importance of awareness of postpartum beliefs and practices among health staff for providing culturally sensitive health care and gaining better co-operation and mutual understanding in giving health care. Copyright © 2012 Elsevier Ltd. All rights reserved.