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Sample records for sway-referenced surround visuospatial

  1. Postural Control Can Be Well Maintained by Healthy, Young Adults in Difficult Visual Task, Even in Sway-Referenced Dynamic Conditions

    National Research Council Canada - National Science Library

    Lions, Cynthia; Bucci, Maria Pia; Bonnet, Cédrick

    2016-01-01

    ... (a control free-viewing task and a difficult searching task), and two postural tasks (one static task in which the platform was maintained stable and a dynamic task in which the platform moved in a sway-referenced manner...

  2. Comparison of Computerized Sway Referencing and Standing on a Compliant Surface

    Science.gov (United States)

    Dean, S. Lance; Paloski, William H.; Wood, Scott J.

    2009-01-01

    Background: By removing vision and altering somatosensory inputs, we can examine the contributions of the vestibular system on balance control. Computerized Dynamic Posturography (CDP) systems accomplish this by using a dynamic plate that moves in proportion to the sway of the subject. A potential alternative to CDP is the use of a compliant foam surface. The goal of this study was to compare postural sway during each condition. Methods: Thirty-two healthy subjects (16 male and 16 female) were tested on a Equitest computerized posturography system and on a 5 inch thick block of foam (NeuroCom International; Clackamas, OR). Subjects performed three trials with their head erect and five trials with dynamic head tilts ( 20 at 0.33Hz) in the anterior-posterior (AP) plane. Subjects were instructed to stand quietly with their arms folded and eyes closed for each trial lasting 20 seconds. The sway in both AP and medial-lateral (ML) planes was calculated for each trial, as well as the total sway path length. Results: In general, AP sway tended to be greater on the Equitest than on foam and greater during the head movement trials than the head erect. The ML sway was consistently higher on foam and did not vary between head erect and moving conditions. Sway path length was consistently greater for head erect trials on foam and tended to be greater for head movement trials on the Equitest. The addition of head movements increases AP sway and the total path length. Conclusions: Based on the increase of sway in the ML direction, it is important to quantify sway in all directions when on a compliant foam surface.

  3. Visuospatial deficits of dyslexic children.

    Science.gov (United States)

    Lipowska, Malgorzata; Czaplewska, Ewa; Wysocka, Anna

    2011-04-01

    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. The experimental group consisted of 62 children with developmental dyslexia. The control group consisted of 67 pupils with no diagnosed deficits, matched to the clinical group in terms of age. We used the Clock Drawing Test (CDT), the Spatial Span subtest from the Wechsler Memory Scale - third edition (WMS - III), the Rey-Osterrieth Complex Figure Test in order to analyze visuospatial functioning. The results show that dyslexics experienced problems with visuospatial functioning, however only while performing difficult tasks. Significant group differences were found for the Clock Drawing Test, Spatial Span - Backward and the precision of figure coping in the Rey-Osterrieth Test. In addition, the results of dyslexic boys were lower than those obtained by all other groups. Our findings provide support for the hypothesis concerning visual deficit as characteristic for dyslexia.

  4. Enhancing the visuo-spatial aptitude of students

    Science.gov (United States)

    Lord, Thomas R.

    Research to date has not been able to agree whether visuo-spatial ability can be influenced through practice. Many have concluded that spatial awareness is an innate phenomena and cannot be learned. Others contend that an individual's visuo-spatial potentials are acquired through interactions with the environment. Many of these theorists believe that spatial thinking can be developed through interactive exercises devised to encourage mental image formation and manipulation. To help alleviate the confusion surrounding this question the following study was undertaken. Eighty-four college undergraduates were randomly placed into control and experimental sections. Student records were examined to assure that the groups did not differ significantly in their verbal or math proficiency and pertinent pretests were given to ascertain spatial levels. The groups were also similar on their male and female ratios. During the semester the experimental section was treated to a 30-minute interaction each week. These sessions involved spatial exercises that required the participants to mentally bisect three-dimensional geometric figures and to envision the shape of the two-dimensional surface formed by the bisection. The subjects drew their mental image of this surface on a sheet of paper. Fourteen weeks later both groups were post tested with a second comparable version of the pretest. Statistical t tests were performed on the group means to see if significant differences developed between the sections. The results indicate that statistical improvement in visuo-spatial cognition did occur for the experimental group in spatial visualization, and spatial orientation. This finding suggests that the weekly intervention sessions had a positive effect on the students' visuo-spatial awareness. These results, therefore, tend to support those researchers that claim visuo-spatial aptitude can be enhanced through teaching.

  5. 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,…

  6. Alertness and visuospatial attention in clinical depression

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    Sturm Walter

    2011-05-01

    Full Text Available Abstract Background Cognitive deficits are a substantial burden in clinical depression. The present study considered dysfunction in the right-hemispheric attention network in depression, examining alertness and visuospatial attention. Methods Three computerized visuospatial attention tests and an alertness test were administered to 16 depressive patients and 16 matched healthy controls. Results Although no significant group effect was observed, alertness predicted reduced visuospatial performance in the left hemifield. Furthermore, sad mood showed a trend towards predicting left visual field omissions. Conclusions Decreased alertness may lead to lower left hemifield visuospatial attention; this mechanism may be responsible for a spatial bias to the right side in depression, even though treatment of depression and anxiety may reduce this cognitive deficit.

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

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    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.

  8. 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

  9. Visuo-Spatial Ability in Colonoscopy Simulator Training

    Science.gov (United States)

    Luursema, Jan-Maarten; Buzink, Sonja N.; Verwey, Willem 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…

  10. The pharmacology of visuospatial attention and inhibition

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    Logemann, H.N.A.

    2013-01-01

    Attention and inhibition are of vital importance in everyday functioning. Problems of attention and inhibition are central to disorders such as Attention Deficit/Hyperactivity Disorder (ADHD). Both bias and disengagement key components of visuospatial attention. Bias refers to neuronal signals that

  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. 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…

  13. 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…

  14. 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. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

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

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    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.

  16. Visuospatial processing in early Alzheimer's disease: a multimodal neuroimaging study

    NARCIS (Netherlands)

    Jacobs, H.I.L.; Gronenschild, E.H.B.M.; Evers, E.A.T.; Ramakers, I.H.G.B.; Hofman, P.A.M.; Backes, W.H.; Jolles, J.; Verhey, F.R.J.; van Boxtel, M.P.J.

    2015-01-01

    Introduction: Dorsal pathway dysfunctions are thought to underlie visuospatial processing problems in Alzheimer disease (AD). Prior studies reported compensatory mechanisms in the dorsal or ventral pathway in response to these functional changes. Since functional and structural connectivity are

  17. Can Limitations of Visuospatial Attention Be Circumvented? A Review.

    Science.gov (United States)

    Wahn, Basil; König, Peter

    2017-01-01

    In daily life, humans are bombarded with visual input. Yet, their attentional capacities for processing this input are severely limited. Several studies have investigated factors that influence these attentional limitations and have identified methods to circumvent them. Here, we provide a review of these findings. We first review studies that have demonstrated limitations of visuospatial attention and investigated physiological correlates of these limitations. We then review studies in multisensory research that have explored whether limitations in visuospatial attention can be circumvented by distributing information processing across several sensory modalities. Finally, we discuss research from the field of joint action that has investigated how limitations of visuospatial attention can be circumvented by distributing task demands across people and providing them with multisensory input. We conclude that limitations of visuospatial attention can be circumvented by distributing attentional processing across sensory modalities when tasks involve spatial as well as object-based attentional processing. However, if only spatial attentional processing is required, limitations of visuospatial attention cannot be circumvented by distributing attentional processing. These findings from multisensory research are applicable to visuospatial tasks that are performed jointly by two individuals. That is, in a joint visuospatial task requiring object-based as well as spatial attentional processing, joint performance is facilitated when task demands are distributed across sensory modalities. Future research could further investigate how applying findings from multisensory research to joint action research may facilitate joint performance. Generally, findings are applicable to real-world scenarios such as aviation or car-driving to circumvent limitations of visuospatial attention.

  18. Visuospatial function in early Alzheimer's disease: Preliminary study

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    Natália Bezerra Mota Quental

    Full Text Available Abstract Alzheimer's disease (AD is the most frequent cause of dementia, accounting for 55% of all cases. AD patients gradually lose functional capacity, manifesting deficits in attention, language, temporal and direction orientation, mood, socialization and visuospatial function. The visuospatial function entails identification of a stimulus and its location. AD patients can present deficits in visuo-spatial skills during initial stages of the disease, but in the course of clinical evolution this function can become severely impaired. One of the neuropsychological tests indicated to evaluate the visuospatial function is the VOSP (The Visual Object and Space Perception Battery. Objectives: The aim of this preliminary study was to detect visuospatial dysfunction in early AD patients using the VOSP, and assess its sensitivity in a Brazilian sample. Results: Controls outperformed AD patients on all neuropsychological evaluations, except the Corsi block tapping task and cancellation task-errors. The AD patients performed significantly worse on all object perception and two space perception (Number Location and Cube Analyses subtests of the VOSP. Conclusion: The AD patients demonstrated impaired visuospatial function in several aspects. The subtests of the VOSP were found to be sensitive for detecting this impairment in mild cases.

  19. Visuospatial memory in patients with obsessive-compulsive disorder

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    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.

  20. Sexual orientation and visuo-spatial ability.

    Science.gov (United States)

    Sanders, G; Ross-Field, L

    1986-07-01

    On the basis of a literature review it was concluded that sex differences in cognitive ability and the etiology of male homosexuality may have a common biological base, leading to the prediction that in terms of cognitive ability homosexual males (HmM) would resemble heterosexual females (HtF) rather than heterosexual males (HtM). This prediction was investigated using visuo-spatial tasks on which males are known to perform better than females. In Experiment 1 HtM performed better on a water level task than HmM and HtF whose performances did not differ significantly. A different version of the water level task and the Vincent Mechanical Diagrams Test were used in Experiment 2; on both tasks the HtM performed better than the HmM and the HtF whose performance did not differ significantly. The results are interpreted as support for a common biological determinant of cognitive ability and male sexual orientation.

  1. Visuospatial training improves elementary students' mathematics performance.

    Science.gov (United States)

    Lowrie, Tom; Logan, Tracy; Ramful, Ajay

    2017-06-01

    Although spatial ability and mathematics performance are highly correlated, there is scant research on the extent to which spatial ability training can improve mathematics performance. This study evaluated the efficacy of a visuospatial intervention programme within classrooms to determine the effect on students' (1) spatial reasoning and (2) mathematics performance as a result of the intervention. The study involved grade six students (ages 10-12) in eight classes. There were five intervention classes (n = 120) and three non-intervention control classes (n = 66). A specifically designed 10-week spatial reasoning programme was developed collaboratively with the participating teachers, with the intervention replacing the standard mathematics curriculum. The five classroom teachers in the intervention programme presented 20 hr of activities aimed at enhancing students' spatial visualization, mental rotation, and spatial orientation skills. The spatial reasoning programme led to improvements in both spatial ability and mathematics performance relative to the control group who received standard mathematics instruction. Our study is the first to show that a classroom-based spatial reasoning intervention improves elementary school students' mathematics performance. © 2017 The British Psychological Society.

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

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    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.

  3. Development of Visuospatial Attention in Typically Developing Children

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    Gaétan Ickx

    2017-12-01

    Full Text Available The aim of the present study is to investigate the development of visuospatial attention in typically developing children and to propose reference values for children for the following six visuospatial attention tests: star cancellation, Ogden figure, reading test, line bisection, proprioceptive pointing and visuo-proprioceptive pointing. Data of 159 children attending primary or secondary school in the Fédération Wallonie Bruxelles (Belgium were analyzed. Results showed that the children's performance on star cancellation, Ogden figure and reading test improved until the age of 13 years, whereas their performance on proprioceptive pointing, visuo-proprioceptive pointing and line bisection was stable with increasing age. These results suggest that the execution of different types of visuospatial attention tasks are not following the same developmental trajectories. This dissociation is strengthened by the lack of correlation observed between tests assessing egocentric and allocentric visuospatial attention, except for the star cancellation test (egocentric and the Ogden figure copy (ego- and allocentric. Reference values are proposed that may be useful to examine children with clinical disorders of visuospatial attention.

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

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    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.

  5. Pharmacological Treatment of Visuospatial Neglect: A Systematic Review.

    Science.gov (United States)

    van der Kemp, Jet; Dorresteijn, Marit; Ten Brink, Antonia F; Nijboer, Tanja C W; Visser-Meily, Johanna M A

    2017-04-01

    The aims of the current review were (1) to give an overview of human studies investigating pharmacotherapy to ameliorate visuospatial neglect and (2) to evaluate the quality of those studies. A systematic literature search using PubMed, Scopus, and ResearchGate was conducted in regard to studies that evaluated pharmacological interventions aiming to ameliorate poststroke visuospatial neglect. The search was limited in the following features: species (human), adults (≥18 years of age), language (English), and type of neglect (visuospatial). Two independent authors extracted data on study content and effectiveness and evaluated the quality of studies and methods. A total of 11 studies were identified. Three studies were considered to be of moderate quality, the others of low quality. Seven studies represented dopaminergic treatment; 3 studies represented cholinergic treatment; and 1 study represented noradrenergic treatment. Three dopaminergic studies showed primarily positive effects of dopaminergic stimulation on visuospatial neglect, whereas three others showed adverse effects. All 3 cholinergic studies found positive effects in some outcome measures concerning visuospatial neglect. Noradrenergic stimulation improved maintenance of attention when exploring space. Currently, cholinergic therapy might be the best option for future research. However, we must emphasize the explorative nature and the limited quality of the reviewed studies. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  6. Hypnosis meets neuropsychology: simulating visuospatial neglect in healthy participants.

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    Priftis, Konstantinos; Schiff, Sami; Tikhonoff, Valérie; Giordano, Nunzia; Amodio, Piero; Umiltà, Carlo; Casiglia, Edoardo

    2011-10-01

    Neglect patients are not aware of stimuli in the contralesional space. We aimed to simulate neglect-like behaviour in healthy participants, by asking them to orient their visuospatial attention in two conditions: non-hypnotic suggestion and post-hypnotic suggestion. Results showed that directing visuospatial attention to one side of space caused neglect of stimuli in the opposite side of space, but only when participants were under post-hypnotic suggestion. Furthermore, directing visuospatial attention to the right side of space caused more neglect of left-sided stimuli than directing visuospatial attention to the left side of space did for right-sided stimuli. We propose that post-hypnotic suggestion can be a useful tool for (de)activating neurocognitive mechanisms underlying visuospatial awareness, a function that is fundamental for our survival. The use of post-hypnotic suggestion could be applied to the study of many domains of cognitive neurosciences (e.g., neurocognitive rehabilitation). Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. 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.

  8. 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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Yaoran Li

    Full Text Available 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.

  11. Visuospatial context learning and configuration learning is associated with analogue traumatic intrusions

    NARCIS (Netherlands)

    Meyer, T.; Krans, J.; van Ast, V.; Smeets, T.

    2017-01-01

    Background and objectives Cognitive and information processing theories of Post-Traumatic Stress Disorder (PTSD) assert that trauma intrusions are characterized by poor contextual embedding of visuospatial memories. Therefore, efficient encoding of visuospatial contextual information might protect

  12. Surround 3-Dimensional Scanner

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    Karbowski Krzysztof

    2017-06-01

    Full Text Available The paper describes original 3-dimensional structured light scanner used for medical application. Scanner kinematics is similar to the gantry mechanism of computed tomography apparatus. The unique feature of the presented scanner is a glass table for capturing image of a human body part. The scanner can acquire an object through the table. It gives the chance for surround scanning of the human body, using only one scanning head, without changing the body position. It is more cost effective scanner solution than multihead scanner configuration.

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

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    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.

  14. 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

  15. Pharmacological Treatment of Visuospatial Neglect : A Systematic Review

    NARCIS (Netherlands)

    van der Kemp, Jet; Dorresteijn, Marit; Ten Brink, Antonia F.; Nijboer, Tanja C W; Visser-Meily, Johanna M A

    Objectives: The aims of the current review were (1) to give an overview of human studies investigating pharmacotherapy to ameliorate visuospatial neglect and (2) to evaluate the quality of those studies. Methods: A systematic literature search using PubMed, Scopus, and ResearchGate was conducted in

  16. Pharmacological Treatment of Visuospatial Neglect : A Systematic Review

    NARCIS (Netherlands)

    van der Kemp, Jet; Dorresteijn, Marit; Ten Brink, Antonia F.; Nijboer, Tanja C.W.|info:eu-repo/dai/nl/304832421; Visser-Meily, Johanna M. A.

    2017-01-01

    Objectives The aims of the current review were (1) to give an overview of human studies investigating pharmacotherapy to ameliorate visuospatial neglect and (2) to evaluate the quality of those studies. Methods A systematic literature search using PubMed, Scopus, and ResearchGate was conducted in

  17. 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…

  18. 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 hypomyelination and ... deficits in shunted HCP children aged between 3 and 7 years. School of Psychology, University of Durban- .... following a focal traumatic brain injury had a right-sided monoparesis. However, owing to small ...

  19. 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

  20. 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.

  1. Top-down cortical interactions in visuospatial attention.

    Science.gov (United States)

    Meehan, Timothy P; Bressler, Steven L; Tang, Wei; Astafiev, Serguei V; Sylvester, Chad M; Shulman, Gordon L; Corbetta, Maurizio

    2017-09-01

    The voluntary allocation of visuospatial attention depends upon top-down influences from the frontal eye field (FEF) and intraparietal sulcus (IPS)-the core regions of the dorsal attention network (DAN)-to visual occipital cortex (VOC), and has been further associated with within-DAN influences, particularly from the FEF to IPS. However, the degree to which these influences manifest at rest and are then modulated during anticipatory visuospatial attention tasks remains poorly understood. Here, we measured both undirected and directed functional connectivity (UFC, DFC) between the FEF, IPS, and VOC at rest and during an anticipatory visuospatial attention task, using a slow event-related design. Whereas the comparison between rest and task indicated FC modulations that persisted throughout the task duration, the large number of task trials we collected further enabled us to measure shorter timescale modulations of FC across the trial. Relative to rest, task engagement induced enhancement of both top-down influences from the DAN to VOC, as well as bidirectional influences between the FEF and IPS. These results suggest that task performance induces enhanced interaction within the DAN and a greater top-down influence on VOC. While resting FC generally showed right hemisphere dominance, task-related enhancement favored the left hemisphere, effectively balancing a resting hemispheric asymmetry, particularly within the DAN. On a shorter (within-trial) timescale, VOC-to-DAN and bidirectional FEF-IPS influences were transiently elevated during the anticipatory period of the trial, evincing phasic modulations related to changing attentional demands. In contrast to these task-specific effects, resting and task-related influence patterns were highly correlated, suggesting a predisposing role for resting organization, which requires minimal tonic and phasic modulations for control of visuospatial attention.

  2. 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

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Thomas Thiery

    Full Text Available 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.

  5. 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.

  6. 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.

  7. Gender differences in visuospatial planning: an eye movements study.

    Science.gov (United States)

    Cazzato, Valentina; Basso, Demis; Cutini, Simone; Bisiacchi, Patrizia

    2010-01-20

    Gender studies report a male advantage in several visuospatial abilities. Only few studies however, have evaluated differences in visuospatial planning behaviour with regard to gender. This study was aimed at exploring whether gender may affect the choice of cognitive strategies in a visuospatial planning task and, if oculomotor measures could assist in disentangling the cognitive processes involved. A computerised task based on the travelling salesperson problem paradigm, the Maps test, was used to investigate these issues. Participants were required to optimise time and space of a path travelling among a set of sub-goals in a spatially constrained environment. Behavioural results suggest that there are no gender differences in the initial visual processing of the stimuli, but rather during the execution of the plan, with males showing a shorter execution time and a higher path length optimisation than females. Males often showed changes of heuristics during the execution while females seemed to prefer a constant strategy. Moreover, a better performance in behavioural and oculomotor measures seemed to suggest that males are more able than females in either the optimisation of spatial features or the realisation of the planned scheme. Despite inconclusive findings, the results support previous research and provide insight into the level of cognitive processing involved in navigation and planning tasks, with regard to the influence of gender.

  8. 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.

  9. 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.

  10. Visuo-spatial Ability in Individuals with Down Syndrome: Is it Really a Strength?

    Science.gov (United States)

    Yang, Yingying; Conners, Frances A.; Merrill, Edward C.

    2014-01-01

    Down syndrome (DS) is associated with extreme difficulty in verbal skills and relatively better visuo-spatial skills. Indeed, visuo-spatial ability is often considered a strength in DS. However, it is not clear whether this strength is only relative to the poor verbal skills, or, more impressively, relative to cognitive ability in general. To answer this question, we conducted an extensive literature review of studies on visuo-spatial abilities in people with Down syndrome from January 1987 to May 2013. Based on a general taxonomy of spatial abilities patterned after Lohman, Pellegrino, Alderton, and Regian (1987) and Carroll (1993) and existing studies of DS, we included five different domains of spatial abilities – visuo-spatial memory, visuo-spatial construction, mental rotation, closure, and wayfinding. We evaluated a total of 49 studies including 127 different comparisons. Most comparisons involved a group with DS vs. a group with typical development matched on mental age and compared on a task measuring one of the five visuo-spatial abilities. Although further research is needed for firm conclusions on some visuo-spatial abilities, there was no evidence that visuo-spatial ability is a strength in DS relative to general cognitive ability. Rather, the review suggests an uneven profile of visuo-spatial abilities in DS in which some abilities are commensurate with general cognitive ability level, and others are below. PMID:24755229

  11. Visuo-spatial ability in individuals with Down syndrome: is it really a strength?

    Science.gov (United States)

    Yang, Yingying; Conners, Frances A; Merrill, Edward C

    2014-07-01

    Down syndrome (DS) is associated with extreme difficulty in verbal skills and relatively better visuo-spatial skills. Indeed, visuo-spatial ability is often considered a strength in DS. However, it is not clear whether this strength is only relative to the poor verbal skills, or, more impressively, relative to cognitive ability in general. To answer this question, we conducted an extensive literature review of studies on visuo-spatial abilities in people with Down syndrome from January 1987 to May 2013. Based on a general taxonomy of spatial abilities patterned after Lohman, Pellegrino, Alderton, and Regian (1987) and Carroll (1993) and existing studies of DS, we included five different domains of spatial abilities - visuo-spatial memory, visuo-spatial construction, mental rotation, closure, and wayfinding. We evaluated a total of 49 studies including 127 different comparisons. Most comparisons involved a group with DS vs. a group with typical development matched on mental age and compared on a task measuring one of the five visuo-spatial abilities. Although further research is needed for firm conclusions on some visuo-spatial abilities, there was no evidence that visuo-spatial ability is a strength in DS relative to general cognitive ability. Rather, the review suggests an uneven profile of visuo-spatial abilities in DS in which some abilities are commensurate with general cognitive ability level, and others are below. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. No arousal-biased competition in focused visuospatial attention

    DEFF Research Database (Denmark)

    Ásgeirsson, Árni Gunnar; Nieuwenhuis, Sander

    2017-01-01

    representations. Here, we report a stringent test of this arousal-biased competition theory in the context of focused visu- ospatial attention. Participants were required to identify a briefly presented target in the context of mul- tiple distractors, which varied in the degree to which they competed...... of the experiments did we find evidence that arousal modulated the effect of distractor competition on the accuracy of target identification. Bayesian statistics revealed moderate to strong evidence against arousal-biased competition. Modeling of the psychophysical data based on Bundesen’s (1990) theory of visual...... attention corroborated the conclusion that arousal does not bias competition in focused visuospatial attention....

  13. Surround articulation. II. Lightness judgments.

    Science.gov (United States)

    Schirillo, J A

    1999-04-01

    It has been hypothesized that to achieve color constancy, lightness judgments require an estimate of the illuminant. A companion paper [J. Opt. Soc. Am. A 16, 793 (1999)] suggests that surround articulation enhances the likelihood that a global luminance edge will be interpreted as being due to changes in illumination rather than in reflectance. Articulation is the process of adding equally spaced incremental and decremental patches within a surround while preserving the surround's space-average luminance. Such a process results in lightness judgments that correlate perfectly with equal local ratio matches. For decrements, lightness constancy does not require articulation. These findings help explain why Arend and Goldstein [J. Opt. Soc. Am. A 4, 2281 (1987)] obtained color constancy with complex Mondrian surrounds but not with simple center surrounds.

  14. The Role of Visuo-Spatial Abilities in Recall of Spatial Descriptions: A Mediation Model

    Science.gov (United States)

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

    2011-01-01

    This research investigates how visuo-spatial abilities (such as mental rotation--MR--and visuo-spatial working memory--VSWM--) work together to influence the recall of environmental descriptions. We tested a mediation model in which VSWM was assumed to mediate the relationship between MR and spatial text recall. First, 120 participants were…

  15. 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.

  16. Fractionation of visuo-spatial memory processes in bipolar depression: a cognitive scaffolding account

    NARCIS (Netherlands)

    Gallagher, P.; Gray, J.M.; Kessels, R.P.C.

    2015-01-01

    BACKGROUND: Previous studies of neurocognitive performance in bipolar disorder (BD) have demonstrated impairments in visuo-spatial memory. The aim of the present study was to use an object-location memory (OLM) paradigm to assess specific, dissociable processes in visuo-spatial memory and examine

  17. Fractionation of visuo-spatial memory processes in bipolar depression: a cognitive scaffolding account

    NARCIS (Netherlands)

    Gallagher, P.; Gray, J.M.; Kessels, R.P.C.

    2015-01-01

    Background Previous studies of neurocognitive performance in bipolar disorder (BD) have demonstrated impairments in visuo-spatial memory. The aim of the present study was to use an object-location memory (OLM) paradigm to assess specific, dissociable processes in visuo-spatial memory and examine

  18. 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…

  19. 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…

  20. The effect of the augmentation of cholinergic neurotransmission by nicotine on EEG indices of visuospatial attention

    NARCIS (Netherlands)

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

    2014-01-01

    The cholinergic system has been implicated in visuospatial attention but the exact role remains unclear. In visuospatial attention, bias refers to neuronal signals that modulate the sensitivity of sensory cortex, while disengagement refers to the decoupling of attention making reorienting possible.

  1. Visuospatial impairment in children and adolescents after liver transplantation.

    Science.gov (United States)

    Haavisto, Anu; Korkman, Marit; Törmänen, Jussi; Holmberg, Christer; Jalanko, Hannu; Qvist, Erik

    2011-03-01

    A minority of children with liver transplants exhibit significant delay in global intelligence; others have specific learning disabilities. More specific data on neurocognitive strengths and weaknesses are lacking. Eighteen children aged 7-16 yr, who had undergone LTx in Finland participated in the study. They were assessed on an average 7.6 (s.d. 4.5, range 1.0-15.0) years post-operatively at a mean age of 11.8 (s.d. 3.1, range 7.2-16.1). A standardized test of intelligence (WISC-III), a neuropsychological test battery (NEPSY-II), and a parental questionnaire on the child's development (FTF) were administered. The neuropsychological test profile of the LTx group was compared with that of a matched control group of healthy children. The LTx children achieved on an average normal FSIQ 94.0 and VIQ 99.6. Their Performance Intelligence Quotient (PIQ 88.9, p=0.043) was, however, significantly lower than the population mean. On neuropsychological assessment, the LTx children scored generally lower than the control group (p=0.004), a difference significant in sub-tests assessing visuospatial and visuoconstructive functions and social perception. No differences emerged in sub-tests of attention and executive functions, memory and learning, or language functions. LTx children are at increased risk for impairment in the visuospatial domain. © 2010 John Wiley & Sons A/S.

  2. 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.

  3. No arousal-biased competition in focused visuospatial attention.

    Science.gov (United States)

    Ásgeirsson, Árni Gunnar; Nieuwenhuis, Sander

    2017-11-01

    Arousal sometimes enhances and sometimes impairs perception and memory. A recent theory attempts to reconcile these findings by proposing that arousal amplifies the competition between stimulus representations, strengthening already strong representations and weakening already weak representations. Here, we report a stringent test of this arousal-biased competition theory in the context of focused visuospatial attention. Participants were required to identify a briefly presented target in the context of multiple distractors, which varied in the degree to which they competed for representation with the target, as revealed by psychophysics. We manipulated arousal using emotionally arousing pictures (Experiment 1), alerting tones (Experiment 2) and white-noise stimulation (Experiment 3), and validated these manipulations with electroencephalography and pupillometry. In none of the experiments did we find evidence that arousal modulated the effect of distractor competition on the accuracy of target identification. Bayesian statistics revealed moderate to strong evidence against arousal-biased competition. Modeling of the psychophysical data based on Bundesen's (1990) theory of visual attention corroborated the conclusion that arousal does not bias competition in focused visuospatial attention. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. 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 predict that activating those features can affect the trajectory of the relational reasoning process. The present work points out that such models do not necessarily specify what those features are though, and endeavors to show that spatial information is likely a part of it. To this end, it presents 2 experiments that used visuospatial priming to affect the course of relational reasoning. The first is a relational category-learning experiment in which this type of priming was shown to affect which spatial relation was learned when multiple were possible. The second used crossmapping analogy problems, paired with this same type of priming, to show that visuospatial cues can make participants more likely to map analogs based on relational roles, even with short presentation times. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  5. 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

  6. 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.

  7. Visuo-spatial abilities are key for young children's verbal number skills.

    Science.gov (United States)

    Cornu, Véronique; Schiltz, Christine; Martin, Romain; Hornung, Caroline

    2017-11-03

    Children's development of verbal number skills (i.e., counting abilities and knowledge of the number names) presents a milestone in mathematical development. Different factors such as visuo-spatial and verbal abilities have been discussed as contributing to the development of these foundational skills. To understand the cognitive nature of verbal number skills in young children, the current study assessed the relation of preschoolers' verbal and visuo-spatial abilities to their verbal number skills. In total, 141 children aged 5 or 6 years participated in the current study. Verbal number skills were regressed on vocabulary, phonological awareness and visuo-spatial abilities, and verbal and visuo-spatial working memory in a structural equation model. Only visuo-spatial abilities emerged as a significant predictor of verbal number skills in the estimated model. Our results suggest that visuo-spatial abilities contribute to a larger extent to children's verbal number skills than verbal abilities. From a theoretical point of view, these results suggest a visuo-spatial, rather than a verbal, grounding of verbal number skills. These results are potentially informative for the conception of early mathematics assessments and interventions. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Emotional conditioning to masked stimuli and modulation of visuospatial attention.

    Science.gov (United States)

    Beaver, John D; Mogg, Karin; Bradley, Brendan P

    2005-03-01

    Two studies investigated the effects of conditioning to masked stimuli on visuospatial attention. During the conditioning phase, masked snakes and spiders were paired with a burst of white noise, or paired with an innocuous tone, in the conditioned stimulus (CS)+ and CS- conditions, respectively. Attentional allocation to the CSs was then assessed with a visual probe task, in which the CSs were presented unmasked (Experiment 1) or both unmasked and masked (Experiment 2), together with fear-irrelevant control stimuli (flowers and mushrooms). In Experiment 1, participants preferentially allocated attention to CS+ relative to control stimuli. Experiment 2 suggested that this attentional bias depended on the perceived aversiveness of the unconditioned stimulus and did not require conscious recognition of the CSs during both acquisition and expression. Copyright 2005 APA, all rights reserved.

  9. 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 posttraining 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.

  10. Visual distraction and visuo-spatial memory: a sandwich effect.

    Science.gov (United States)

    Tremblay, Sébastien; Nicholls, Alastair P; Parmentier, Fabrice B R; Jones, Dylan M

    2005-01-01

    The functional characteristics of visuo-spatial serial memory and its sensitivity to irrelevant visual information are examined in the present study, through the investigation of the sandwich effect (e.g., Hitch, 1975). The memory task was one of serial recall for the position of a sequence of seven spatially and temporally separated dots. The presence of irrelevant dots interpolated with to-be-remembered dots affected performance over most serial positions (Experiment 1) but that effect was significantly reduced when the interpolated dots were distinct from the to-be-remembered dots by colour and shape (Experiment 2). Parallels are made between verbal and spatial serial memory, and the reduction of the sandwich effect is discussed in terms of the contribution of perceptual organisation and attentional factors in short-term memory.

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

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    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.

  12. The Effect of Aging and Attention on Visual Crowding and Surround Suppression of Perceived Contrast Threshold.

    Science.gov (United States)

    Malavita, Menaka S; Vidyasagar, Trichur R; McKendrick, Allison M

    2017-02-01

    The purpose of this study was to study how, in midperipheral vision, aging affects visual processes that interfere with target detection (crowding and surround suppression) and to determine whether the performance on such tasks are related to visuospatial attention as measured by visual search. We investigated the effect of aging on crowding and suppression in detection of a target in peripheral vision, using different types of flanking stimuli. Both thresholds were also obtained while varying the position of the flanker (placed inside or outside of target, relative to fixation). Crowding thresholds were also estimated with spatial uncertainty (jitter). Additionally, we included a visual search task comprising Gabor stimuli to investigate whether performance is related to top-down attention. Twenty young adults (age, 18-32 years; mean age, 26.1 years; 10 males) and 19 older adults (age, 60-74 years; mean age, 70.3 years; 10 males) participated in the study. Older adults showed more surround suppression than the young (F[1,37] = 4.21; P attentional efficiency measured in the visual search task. There was also no significant correlation between crowding and surround suppression. We show that aging does not affect visual crowding but does increase surround suppression of contrast, suggesting that crowding and surround suppression may be distinct visual phenomena. Furthermore, strengths of crowding and surround suppression did not correlate with each other nor could they be predicted by efficiency of visual search.

  13. Visuospatial processing in early Alzheimer’s disease: a multimodal neuroimaging study

    NARCIS (Netherlands)

    Jacobs, H.I.L.; Gronenschild, E. H. B. M.; Evers, E.A.T.; Ramakers, I.H.G.B.; Hofman, P.A.M.; Backes, W. H.; Jolles, J.; Verhey, F. R. J.

    2013-01-01

    Introduction: Dorsal pathway dysfunctions are thought to underlie visuospatial processing problems in Alzheimer disease (AD). Prior studies reported compensatory mechanisms in the dorsal or ventral pathway in response to these functional changes. Since functional and structural connectivity are

  14. Verbal and visuospatial working memory as predictors of children's reading ability.

    Science.gov (United States)

    Pham, Andy V; Hasson, Ramzi M

    2014-08-01

    Children with reading difficulties often demonstrate weaknesses in working memory (WM). This research study explored the relation between two WM systems (verbal and visuospatial WM) and reading ability in a sample of school-aged children with a wide range of reading skills. Children (N = 157), ages 9-12, were administered measures of short-term memory, verbal WM, visuospatial WM, and reading measures (e.g., reading fluency and comprehension). Although results indicated that verbal WM was a stronger predictor in reading fluency and comprehension, visuospatial WM also significantly predicted reading skills, but provided more unique variance in reading comprehension than reading fluency. These findings suggest that visuospatial WM may play a significant role in higher level reading processes, particularly in reading comprehension, than previously thought. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. 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

  16. 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,

  17. Mental Rotation With and Without a Concurrent Task: Moderating Effects of Visuospatial Ability

    Science.gov (United States)

    1994-04-01

    respectively. The WAIS Digit Span Test ( Weschler , 1955) was given to determine the average digit span for the concurrent task, as in Kail (1991). 32...visuospatial ability as assessed on a battery of visuospatial tests (Card Rotations, Mental Rotations, Minnesota Paper Form Board), performed a computer...by Angle for Dual-Task Condition .......... 49 Table 1. Mean Scores on the Screening Battery Tests . . 35 Table 2. Raw and Z-score Ranges on the

  18. 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.

  19. Co-speech iconic gestures and visuo-spatial working memory.

    Science.gov (United States)

    Wu, Ying Choon; Coulson, Seana

    2014-11-01

    Three experiments tested the role of verbal versus visuo-spatial working memory in the comprehension of co-speech iconic gestures. In Experiment 1, participants viewed congruent discourse primes in which the speaker's gestures matched the information conveyed by his speech, and incongruent ones in which the semantic content of the speaker's gestures diverged from that in his speech. Discourse primes were followed by picture probes that participants judged as being either related or unrelated to the preceding clip. Performance on this picture probe classification task was faster and more accurate after congruent than incongruent discourse primes. The effect of discourse congruency on response times was linearly related to measures of visuo-spatial, but not verbal, working memory capacity, as participants with greater visuo-spatial WM capacity benefited more from congruent gestures. In Experiments 2 and 3, participants performed the same picture probe classification task under conditions of high and low loads on concurrent visuo-spatial (Experiment 2) and verbal (Experiment 3) memory tasks. Effects of discourse congruency and verbal WM load were additive, while effects of discourse congruency and visuo-spatial WM load were interactive. Results suggest that congruent co-speech gestures facilitate multi-modal language comprehension, and indicate an important role for visuo-spatial WM in these speech-gesture integration processes. Copyright © 2014 Elsevier B.V. All rights reserved.

  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. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Contribution of Visuospatial and motion-tracking to invisible motion

    Directory of Open Access Journals (Sweden)

    Luca Battaglini

    2016-09-01

    Full Text Available People experience an object’s motion even when it is occluded. We investigate the processing of invisible motion in three experiments. Observers saw a moving circle passing behind an invisible, irregular hendecagonal polygon and had to respond as quickly as possible when the target had just reappeared from behind the occluder. Without explicit cues allowing the end of each of the eight hidden trajectories to be predicted (length ranging between 4.7 and 5 deg, we found as expected, if visuospatial attention was involved, anticipation errors, providing that information on pre-occluder motion was available. This indicates that the observers, rather than simply responding when they saw the target, tended to anticipate its reappearance (Experiment 1. The new finding is that, with a fixation mark indicating the centre of the invisible trajectory, a linear relationship between the physical and judged occlusion duration is found, but not without it (Experiment 2 or with a fixation mark varying in position from trial to trial (Experiment 3. We interpret the role of central fixation in the differences in distinguishing trajectories smaller than 0.3 deg, by suggesting that it reflects spatiotemporal computation and motion-tracking. These two mechanisms allow visual imagery to form of the point symmetrical to that of the disappearance, with respect to fixation, and then for the occluded moving target to be tracked up to this point.

  2. Contribution of Visuospatial and Motion-Tracking to Invisible Motion.

    Science.gov (United States)

    Battaglini, Luca; Casco, Clara

    2016-01-01

    People experience an object's motion even when it is occluded. We investigate the processing of invisible motion in three experiments. Observers saw a moving circle passing behind an invisible, irregular hendecagonal polygon and had to respond as quickly as possible when the target had "just reappeared" from behind the occluder. Without explicit cues allowing the end of each of the eight hidden trajectories to be predicted (length ranging between 4.7 and 5 deg), we found as expected, if visuospatial attention was involved, anticipation errors, providing that information on pre-occluder motion was available. This indicates that the observers, rather than simply responding when they saw the target, tended to anticipate its reappearance (Experiment 1). The new finding is that, with a fixation mark indicating the center of the invisible trajectory, a linear relationship between the physical and judged occlusion duration is found, but not without it (Experiment 2) or with a fixation mark varying in position from trial to trial (Experiment 3). We interpret the role of central fixation in the differences in distinguishing trajectories smaller than 0.3 deg, by suggesting that it reflects spatiotemporal computation and motion-tracking. These two mechanisms allow visual imagery to form of the point symmetrical to that of the disappearance, with respect to fixation, and then for the occluded moving target to be tracked up to this point.

  3. 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.

  4. Opportunity's Surroundings on Sol 1818

    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 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  5. Association Between Visuospatial Ability and Vestibular Function in the Baltimore Longitudinal Study of Aging.

    Science.gov (United States)

    Bigelow, Robin T; Semenov, Yevgeniy R; Trevino, Carolina; Ferrucci, Luigi; Resnick, Susan M; Simonsick, Eleanor M; Xue, Qian-Li; Agrawal, Yuri

    2015-09-01

    To investigate the relationship between vestibular loss associated with aging and age-related decline in visuospatial function. Cross-sectional analysis within a prospective cohort study. Baltimore Longitudinal Study of Aging (BLSA). Community-dwelling BLSA participants with a mean age of 72 (range 26-91) (N = 183). Vestibular function was measured using vestibular-evoked myogenic potentials. Visuospatial cognitive tests included Card Rotations, Purdue Pegboard, Benton Visual Retention Test, and Trail-Making Test Parts A and B. Tests of executive function, memory, and attention were also considered. Participants underwent vestibular and cognitive function testing. In multiple linear regression analyses, poorer vestibular function was associated with poorer performance on Card Rotations (P = .001), Purdue Pegboard (P = .005), Benton Visual Retention Test (P = 0.008), and Trail-Making Test Part B (P = .04). Performance on tests of executive function and verbal memory were not significantly associated with vestibular function. Exploratory factor analyses in a subgroup of participants who underwent all cognitive tests identified three latent cognitive abilities: visuospatial ability, verbal memory, and working memory and attention. Vestibular loss was significantly associated with lower visuospatial and working memory and attention factor scores. Significant consistent associations between vestibular function and tests of visuospatial ability were observed in a sample of community-dwelling adults. Impairment in visuospatial skills is often one of the first signs of dementia and Alzheimer's disease. Further longitudinal studies are needed to evaluate whether the relationship between vestibular function and visuospatial ability is causal. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

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

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    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.

  7. Opportunity's Surroundings on Sol 1798

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. 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 lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  8. 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

  9. 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.

  10. 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.

  11. 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.

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

    Science.gov (United States)

    Chueh, Ting-Yu; Huang, Chung-Ju; Hsieh, Shu-Shih; Chen, Kuan-Fu; Chang, Yu-Kai; Hung, Tsung-Min

    2017-01-01

    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.

  13. 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. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.

  15. 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.

  16. 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.

  17. 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.

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

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    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.

  19. 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…

  20. 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.

  1. 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

    2017-01-01

    Background: 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…

  2. Visuospatial Working Memory in Adolescents with Poor Performance in Mathematics: Variation Depending on Reading Skills

    Science.gov (United States)

    Kyttala, Minna

    2008-01-01

    The first purpose of this study was to investigate whether the visuospatial working memory (VSWM) skills of 15-16-year-old pupils with difficulties in mathematics differ from those of their normally achieving peers. The goal was to broaden the view of the complex system of VSWM. A set of passive and active VSWM tasks was used. The study's second…

  3. Empowering Visuo-Spatial Ability in Primary School: Results from a Follow-Up Study

    Science.gov (United States)

    Fastame, Maria Chiara; Callai, Daniela

    2015-01-01

    The current study was primarily aimed at verifying the effect of a combined computer-assisted and pencil-and-paper training that was developed to empower visuo-spatial abilities in primary school pupils. One hundred and twenty third grade (mean average: eight years old) and fourth grade (mean age: nine years old) students attending several Italian…

  4. The Genetic and Environmental Structure of Verbal and Visuospatial Memory in Young Adults and Children

    NARCIS (Netherlands)

    van Leeuwen, M.; van den Berg, S.M.; Hoekstra, R.A.; Boomsma, D.I.

    2009-01-01

    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

  5. The genetic and environmental structure of verbal and visuospatial memory in young adults and children

    NARCIS (Netherlands)

    van Leeuwen, Marieke; van den Berg, Stéphanie Martine; Hoekstra, Rosa A.; Boomsma, Dorret I.

    2009-01-01

    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

  6. Visuospatial Orientation Learning through Virtual Reality for People with Severe Disability

    Science.gov (United States)

    de la Torre-Luque, Alejandro; Valero-Aguayo, Luis; de la Rubia-Cuestas, Ernesto J.

    2017-01-01

    This study aims to test how an intervention based on virtual reality (VR) may enhance visuospatial skills amongst people with disability. A quasi-experimental intra-group study was therefore conducted. Participants were 20 people with severe disability (65% males; 34.35 years, on average, and 84.95% of disability rate according to the Andalusian…

  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. Some Factors Underlying Mathematical Performance: The Role of Visuospatial Working Memory and Non-Verbal Intelligence

    Science.gov (United States)

    Kyttala, Minna; Lehto, Juhani E.

    2008-01-01

    Passive and active visuospatial working memory (VSWM) were investigated in relation to maths performance. The mental rotation task was employed as a measure of active VSWM whereas passive VSWM was investigated using a modified Corsi Blocks task and a matrix pattern task. The Raven Progressive Matrices Test measured fluid intelligence. A total of…

  9. Brain activity during a visuospatial working memory task predicts arithmetical performance 2 years later.

    Science.gov (United States)

    Dumontheil, Iroise; Klingberg, Torkel

    2012-05-01

    Visuospatial working memory (WM) capacity is highly correlated with mathematical reasoning abilities and can predict future development of arithmetical performance. Activity in the intraparietal sulcus (IPS) during visuospatial WM tasks correlates with interindividual differences in WM capacity. This region has also been implicated in numerical representation, and its structure and activity reflect arithmetical performance impairments (e.g., dyscalculia). We collected behavioral (N = 246) and neuroimaging data (N = 46) in a longitudinal sample to test whether IPS activity during a visuospatial WM task could provide more information than psychological testing alone and predict arithmetical performance 2 years later in healthy participants aged 6-16 years. Nonverbal reasoning and verbal and visuospatial WM measures were found to be independent predictors of arithmetical outcome. In addition, WM activation in the left IPS predicted arithmetical outcome independently of behavioral measures. A logistic model including both behavioral and imaging data showed improved sensitivity by correctly classifying more than twice as many children as poor arithmetical performers after 2 years than a model with behavioral measures only. These results demonstrate that neuroimaging data can provide useful information in addition to behavioral assessments and be used to improve the identification of individuals at risk of future low academic performance.

  10. 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

  11. 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

  12. 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)…

  13. 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.

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

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    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.

  15. Exploring Visuospatial Thinking in Learning about Mineralogy: Spatial Orientation Ability and Spatial Visualization Ability

    Science.gov (United States)

    Ozdemir, Gokhan

    2010-01-01

    This mixed-method research attempted to clarify the role of visuospatial abilities in learning about mineralogy. Various sources of data--including quantitative pre- and postmeasures of spatial visualization and spatial orientation tests and achievement scores on six measures and qualitative unstructured observations, interviews, and field trip…

  16. Strategies and Correlates of Jigsaw Puzzle and Visuospatial Performance by Persons with Prader-Willi Syndrome

    Science.gov (United States)

    Verdine, Brian N.; Troseth, Georgene L.; Hodapp, Robert M.; Dykens, Elisabeth M.

    2008-01-01

    Some individuals with Prader-Willi syndrome exhibit strengths in solving jigsaw puzzles. We compared visuospatial ability and jigsaw puzzle performance and strategies of 26 persons with Prader-Willi syndrome and 26 MA-matched typically developing controls. Individuals with Prader-Willi syndrome relied on piece shape. Those in the control group…

  17. Is there a relationship between ultrasound scanning ability (sonography) and visuospatial perception or psychomotor ability?

    Science.gov (United States)

    Hagen, Suzanne; Gallagher, Helen

    2016-01-01

    Background Competent sonography is thought to include a unique combination of skills not yet fully defined. This presents challenges when recruiting the correct people for training. Skills are thought to include visuospatial perception and psychomotor skills, but little is known about the relationship between these aptitudes and scanning ability. This feasibility study explored such relationships, to identify evaluation techniques which may improve selection and recruitment. Methods A sample of 30 experienced ultrasound practitioners and 30 trainees at commencement and on completion of training were administered eight tests. Results No significant relationships between experienced practitioners’ or trainees’ visuospatial abilities or psychomotor abilities and scanning abilities were found. Results demonstrated that two of the visuospatial perception tests were not influenced by training and therefore, may be measuring the innate skills of ultrasound practitioners. As ultrasound practitioners had not performed any of the tests previously, ranges of scores for each of the eight tests were established for this group. This included measures for psychomotor skills which added to the current body of knowledge for sonography. Conclusions Although no significant correlations were found between participants’ visuospatial perception or psychomotor abilities and scanning ability, performance on the Obstetric Structured Assessment Test (combining all the skills required) pre-training gave the best indication of post-training scanning performance. The Obstetric Structured Assessment Test may prove a useful tool for initial assessment of potential trainees but abilities will require further investigation. PMID:27847536

  18. Blocks, Bricks, and Planks: Relationships between Affordance and Visuo-Spatial Constructive Play Objects

    Science.gov (United States)

    Ness, Daniel; Farenga, Stephen J.

    2016-01-01

    The authors consider the strengths and weaknesses of three different visuo-spatial constructive play object (VCPO) types--blocks, bricks, and planks--and their impact on the development of creativity in spatial thinking and higher learning during free play. Each VCPO has its own set of attributes, they note, leading to different purposes,…

  19. Event-related alpha and theta responses in a visuo-spatial working memory task

    NARCIS (Netherlands)

    Bastiaansen, Marcel C. M.; Posthuma, Danielle; Groot, Paul F. C.; de Geus, Eco J. C.

    2002-01-01

    To explore the reactivity of the theta and alpha rhythms during visuo-spatial working memory. One hundred and seventy-four subjects performed a delayed response task. They had to remember the spatial location of a target stimulus on a computer screen for a 1 or a 4s retention interval. The target

  20. Event-related alpha and theta responses in a visuo-spatial working memory task

    NARCIS (Netherlands)

    Bastiaansen, M.C.M.; Posthuma, D.; Groot, P.F.C.; de Geus, E.J.C.

    2002-01-01

    Objective: To explore the reactivity of the theta and alpha rhythms during visuo-spatial working memory. Methods: One hundred and seventy-four subjects performed a delayed response task. They had to remember the spatial location of a target stimulus on a computer screen for a 1 or a 4s retention

  1. 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.

  2. What is the Relationship between Synaesthesia and Visuo-Spatial Number Forms?

    Science.gov (United States)

    Sagiv, Noam; Simner, Julia; Collins, James; Butterworth, Brian; Ward, Jamie

    2006-01-01

    This study compares the tendency for numerals to elicit spontaneous perceptions of colour or taste (synaesthesia) with the tendency to visualise numbers as occupying particular visuo-spatial configurations (number forms). The prevalence of number forms was found to be significantly higher in synaesthetes experiencing colour compared both to…

  3. Visuospatial processing in schizophrenia: does it share common mechanisms with pseudoneglect?

    Science.gov (United States)

    Cavézian, Céline; Michel, Carine; Rossetti, Yves; Danckert, James; d'Amato, Thierry; Saoud, Mohamed

    2011-07-01

    Schizophrenia patients demonstrate behavioural and cerebral lateralised anomalies, prompting some authors to suggest they exhibit a mild form of right unilateral neglect. To better describe and understand lateralised visuospatial anomalies in schizophrenia, three experiments were run using tasks often utilised to study visuospatial processing in healthy individuals and in neglect patients: the Behavioural Inattention Test (BIT), the manual line bisection task with and without a local cueing paradigm, the landmark task (or line bisection judgement), and the number bisection task. Although the schizophrenia patients did not exhibit the full-blown neglect syndrome, they did demonstrate marked spatial biases that differentiated them from controls on all but two tasks. More specifically, schizophrenia patients showed neither a simple perceptual deficit nor an asymmetry, but demonstrated (1) lateralised anomalies on a simple manual line bisection task; (2) unilateral attentional deficits for line bisection within a local cueing paradigm; and (3) a lateralised deficit in the visuospatial representations of numbers. Altogether, these results suggest a right hemineglect-like deficit in schizophrenia in attentional, representational, and motor-intentional processes. Yet it does not appear to be as strong a phenomenon. Indeed, it could be considered as an accentuation of the normal asymmetry in visuospatial processing.

  4. 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…

  5. Covert is better than overt when rehearsing Visuo-Spatial information in working memory

    NARCIS (Netherlands)

    Godijn, R.J.; Theeuwes, J.

    2012-01-01

    In the present study, we examined whether eye movements facilitate retention of visuo-spatial information in working memory. In two experiments, participants memorised the sequence of the spatial locations of six digits across a retention interval. In some conditions, participants were free to move

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

    NARCIS (Netherlands)

    Ewijk, H. van; Weeda, W.D.; Heslenfeld, D.J.; Luman, M.; Hartman, C.A.; Hoekstra, P.J.; Faraone, S.V.; Franke, B.; Buitelaar, J.K.; Oosterlaan, J.

    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

  7. 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…

  8. Comparison of fMRI paradigms assessing visuospatial processing: Robustness and reproducibility

    Science.gov (United States)

    Herholz, Peer; Zimmermann, Kristin M.; Westermann, Stefan; Frässle, Stefan; Jansen, Andreas

    2017-01-01

    The development of brain imaging techniques, in particular functional magnetic resonance imaging (fMRI), made it possible to non-invasively study the hemispheric lateralization of cognitive brain functions in large cohorts. Comprehensive models of hemispheric lateralization are, however, still missing and should not only account for the hemispheric specialization of individual brain functions, but also for the interactions among different lateralized cognitive processes (e.g., language and visuospatial processing). This calls for robust and reliable paradigms to study hemispheric lateralization for various cognitive functions. While numerous reliable imaging paradigms have been developed for language, which represents the most prominent left-lateralized brain function, the reliability of imaging paradigms investigating typically right-lateralized brain functions, such as visuospatial processing, has received comparatively less attention. In the present study, we aimed to establish an fMRI paradigm that robustly and reliably identifies right-hemispheric activation evoked by visuospatial processing in individual subjects. In a first study, we therefore compared three frequently used paradigms for assessing visuospatial processing and evaluated their utility to robustly detect right-lateralized brain activity on a single-subject level. In a second study, we then assessed the test-retest reliability of the so-called Landmark task–the paradigm that yielded the most robust results in study 1. At the single-voxel level, we found poor reliability of the brain activation underlying visuospatial attention. This suggests that poor signal-to-noise ratios can become a limiting factor for test-retest reliability. This represents a common detriment of fMRI paradigms investigating visuospatial attention in general and therefore highlights the need for careful considerations of both the possibilities and limitations of the respective fMRI paradigm–in particular, when being

  9. 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.

  10. Video gaming enhances psychomotor skills but not visuospatial and perceptual abilities in surgical trainees.

    Science.gov (United States)

    Kennedy, A M; Boyle, E M; Traynor, O; Walsh, T; Hill, A D K

    2011-01-01

    There is considerable interest in the identification and assessment of underlying aptitudes or innate abilities that could potentially predict excellence in the technical aspects of operating. However, before the assessment of innate abilities is introduced for high-stakes assessment (such as competitive selection into surgical training programs), it is essential to determine that these abilities are stable and unchanging and are not influenced by other factors, such as the use of video games. The aim of this study was to investigate whether experience playing video games will predict psychomotor performance on a laparoscopic simulator or scores on tests of visuospatial and perceptual abilities, and to examine the correlation, if any, between these innate abilities. Institutional ethical approval was obtained. Thirty-eight undergraduate medical students with no previous surgical experience were recruited. All participants completed a self-reported questionnaire that asked them to detail their video game experience. They then underwent assessment of their psychomotor, visuospatial, and perceptual abilities using previously validated tests. The results were analyzed using independent samples t tests to compare means and linear regression curves for subsequent analysis. Students who played video games for at least 7 hours per week demonstrated significantly better psychomotor skills than students who did not play video games regularly. However, there was no difference on measures of visuospatial and perceptual abilities. There was no correlation between psychomotor tests and visuospatial or perceptual tests. Regular video gaming correlates positively with psychomotor ability, but it does not seem to influence visuospatial or perceptual ability. This study suggests that video game experience might be beneficial to a future career in surgery. It also suggests that relevant surgical skills may be gained usefully outside the operating room in activities that are not

  11. Visual object and visuospatial cognition in Huntington's disease: implications for information processing in corticostriatal circuits.

    Science.gov (United States)

    Lawrence, A D; Watkins, L H; Sahakian, B J; Hodges, J R; Robbins, T W

    2000-07-01

    The primate visual system contains two major streams of visual information processing. The ventral stream is directed into the inferior temporal cortex and is concerned with visual object cognition, whereas the dorsal stream is directed into the posterior parietal cortex and is concerned with visuospatial cognition. Both of these processing streams send projections to the basal ganglia, and the ventral stream may also receive reciprocal connections from the basal ganglia. Although a role for the basal ganglia in visual object and visuospatial cognition has been suggested, little work has been carried out in this area in humans. The primary site of neuropathology in Huntington's disease is the basal ganglia, and hence Huntington's disease provides an important model for the role of the human basal ganglia in visual object and visuospatial cognition, and its breakdown in disease. We examined performance on a wide battery of tests of both visual object and visuospatial recognition memory, working memory, attention, associative learning and perception, enabling us to specify more fully the role of the basal ganglia in visual object and visuospatial cognition, and the disruption of these processes in Huntington's disease. Huntington's disease patients exhibited deficits on tests of pattern and spatial recognition memory; showed impaired simultaneous matching and delay-independent delayed matching-to-sample deficits; showed spared accuracy but impaired reaction times in visual search; were impaired in spatial but not visual object working memory; and showed impaired pattern-location associative learning. The results of our investigations suggest a particular role for the striatum in context-dependent action selection, in line with current computational theories of basal ganglia function.

  12. 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.

  13. Local Computation of Lightness on Articulated Surrounds

    Directory of Open Access Journals (Sweden)

    Masataka Sawayama

    2012-09-01

    Full Text Available Lightness of a grey target on a uniform light (or dark surround changes by articulating the surround (articulation effect. To elucidate the processing of lightness underlying the articulation effect, the present study introduced transparency over a dark surround and investigated its effects on lightness of the target. The transparency was produced by adding a contiguous external field to the dark surround while keeping local stimulus configuration constant. Results showed that the target lightness did not change on the articulated surround when a dark transparent filter was perceived over the target, although it did on the uniform surround. These results suggest that image decomposition into a transparent filter and an underlying surface does not necessarily change lightness of the surface if the surface is articulated. Moreover, the present study revealed that articulating the surround does not always enhance lightness contrast; it can reduce the contrast effect when the target luminance is not the highest within the surround. These findings are consistent with the theoretical view that lightness perception on articulated surfaces is determined locally within a spatially limited region, and they also place a constraint on how the luminance distribution within the limited region is scaled.

  14. Rehabilitation of Visuospatial Cognition and Visual Exploration in Neglect: a Cross-over Study.

    Science.gov (United States)

    Kerkhoff, Georg

    1998-01-01

    Right hemispheric brain damage is often accompanied by visual neglect of contralesional hemispace as well as profound visuospatial and visuoconstructive disorders. Despite some recent improvements in the treatment of neglect, few therapeutic approaches exist for disorders of visuospatial cognition and none has dealt with the question of how both disorders can be treated in combination. In the present cross-over rehabilitation study, thirteen neglect patients first received visual exploration training for six weeks followed by visuospatial training for four weeks. Eleven patients had a right-hemispheric lesion, 2 a left-hemispheric lesion. Ten subjects had parietal cortical lesions, 3 lesions were outside the parietal lobe. In the first treatment phase the patients received training, using computer controlled devices, intended to improve visual search and reading strategies. In the second phase of treatment, visual orientation discrimination was trained on a PC-monitor with verbal feedback by the therapist. Significant improvements were obtained after exploration training regarding the extent of visual search-field witbin the neglected hemifield, visual search performance in the whole visual field, reading time and reading errors but there was no change after visuospatial training for any of these measures. The reverse pattern was observed for visuospatial training: significant improvements were observed in line orientation judgements, clock perception, mental transposition of angles, horizontal writing and visuoconstructive abilities, but there was no change in any of these tests during exploration training. Feedback-based training of visual orientation discrimination revealed rapid (within 8-15 sessions) and stable improvements in this ability and a transfer to spatially related tasks.No significant correlations were obtained between training-related improvements and the time since brain damage for 9 of 10 tests, indicating that spontaneous recovery had no effect

  15. A Replication of “Motor and Visual Codes Interact to Facilitate Visuospatial Memory Performance (2007; Experiment 1)”

    OpenAIRE

    Vanessa P. Rowe; Sébastien Lagacé; Katherine Guérard

    2015-01-01

    The present study is a replication of Chum, Bekkering, Dodd, and Pratt (2007). Motor and visual codes interact to facilitate visuospatial memory performance. Psychonomic Bulletin & Review, 14, 1189-1193.

  16. A Replication of “Motor and Visual Codes Interact to Facilitate Visuospatial Memory Performance (2007; Experiment 1”

    Directory of Open Access Journals (Sweden)

    Vanessa P. Rowe

    2015-02-01

    Full Text Available The present study is a replication of Chum, Bekkering, Dodd, and Pratt (2007. Motor and visual codes interact to facilitate visuospatial memory performance. Psychonomic Bulletin & Review, 14, 1189-1193.

  17. Evidence of the impact of visuo-spatial processing on magnitude representation in 22q11.2 microdeletion syndrome.

    Science.gov (United States)

    Attout, Lucie; Noël, Marie-Pascale; Vossius, Line; Rousselle, Laurence

    2017-05-01

    The influence of visuo-spatial skills on numerical magnitude processing is the subject of a long-standing debate. As most of the numerical and non-numerical magnitude abilities underpinning mathematical development are visual by nature, they are often assessed in the visual modality, thereby confusing visuo-spatial and numerical processing. In order to assess the influence of visuo-spatial processing on numerical magnitude representation, we examined magnitude processing in patients with 22q11.2 deletion syndrome (22q11DS), a genetic condition characterized by a cognitive profile with a relative weakness in visuo-spatial abilities but with preserved verbal abilities. Twenty-seven participants with 22q11DS were compared to two control groups (one matched on verbal intelligence and the other on visuo-spatial abilities) on several magnitude comparison tasks each with different visuo-spatial processing requirements. Our results showed that participants with 22q11DS present a consistent pattern of impairment in magnitude comparison tasks requiring the processing of visuo-spatial dimensions: comparison of lengths and collections. In contrast, their performance did not differ from the control groups in a visual task with no spatial processing requirement (i.e. numerical comparison of flashed dot sequences) or in auditory tasks (i.e., duration comparison and numerical comparison of sound sequences). Finally, a specific deficit of enumeration processes was observed in the subitizing range. Taken together, these results show that deficits in magnitude can occur as a consequence of a visuo-spatial deficit. This highlights the influence of the nature of the tasks selected to assess magnitude representation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The neurophysiological performance of visuospatial working memory in children with developmental coordination disorder.

    Science.gov (United States)

    Tsai, Chia-Liang; Chang, Yu-Kai; Hung, Tsung-Min; Tseng, Yu-Ting; Chen, Tzu-Chi

    2012-12-01

    The objective of this study was to investigate the mechanisms underlying the deficit in visuospatial working memory (VSWM) seen in children with developmental coordination disorder (DCD) and to compare brain activity while performing a VSWM task in children with DCD and typically developing children. Behavioural performance and event-related potentials (ERPs) were recorded in 24 children (12 males, 12 females; mean age 139 mo, SD 4 mo) with DCD (as determined by a score ERP data suggests that children with DCD have deficits of visuospatial working memory owing to fewer resources being allocated to comparison of spatial locations, less effort allotted to the response selection, and less neural processing employed during the retrieval process phase. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

  19. Towards an earlier diagnosis of Alzheimer's disease presenting with visuospatial disorders (posterior cortical atrophy).

    Science.gov (United States)

    Vighetto, A

    2013-10-01

    Progressive visual complaints related to visuospatial disorders, and less often to visuoperceptual disorders, may be the presenting and isolated manifestation of a focal degeneration in the posterior cortical areas, called posterior cortical atrophy (PCA). PCA is a clinical syndrome corresponding to a focal variant of Alzheimer's disease in 80% of cases. The predominant dysfunction in the occipitoparietal pathways results in predominant visuospatial disorders, manifesting primarily as dorsal simultanagnosia, alone or associated with other symptoms of Balint's syndrome. PCA is rare and affects young patients who are fully aware of their deficits. Diagnosis of PCA is often delayed, due to insidious onset and development of symptoms, and to poor awareness of the condition in the medical community. An earlier diagnosis requires both better knowledge of PCA among ophthalmologists and neurologists and better recognition of visual complaints, leading to simple bedside tasks that can tackle the syndrome. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  20. Age-Related Declines in Visuospatial Working Memory Correlate With Deficits in Explicit Motor Sequence Learning

    OpenAIRE

    Bo, J; Borza, V.; Seidler, R. D.

    2009-01-01

    Numerous studies have shown that older adults exhibit deficits in motor sequence learning, but the mechanisms underlying this effect remain unclear. Our recent work has shown that visuospatial working-memory capacity predicts the rate of motor sequence learning and the length of motor chunks formed during explicit sequence learning in young adults. In the current study, we evaluate whether age-related deficits in working memory explain the reduced rate of motor sequence learning in older adul...

  1. Understanding the role of visuo-spatial working memory in adult mathematics

    OpenAIRE

    Hubber, Paula Jane

    2015-01-01

    Mathematics is an important part of everyday adult life and requires skilled use of a variety of cognitive resources. The aim of this thesis was to explore the use of working memory in adult mathematics performance and particularly the role of visuo-spatial working memory. \\ud In the first study, differences in working memory capacity between skilled adult mathematicians and those who have less expertise in mathematics were investigated. This involved the use of working memory span tasks that...

  2. Genetic contributions to visuospatial cognition in Williams syndrome: insights from two contrasting partial deletion patients

    OpenAIRE

    Broadbent, H.; Farran, E.K.; Chin, E; Metcalfe, K; Tassabehji, M; Turnpenny, P; Sansbury, F.; Meaburn, Emma L.; Karmiloff-Smith, Annette

    2014-01-01

    \\ud Background\\ud \\ud Williams syndrome (WS) is a rare neurodevelopmental disorder arising from a hemizygotic deletion of approximately 27 genes on chromosome 7, at locus 7q11.23. WS is characterised by an uneven cognitive profile, with serious deficits in visuospatial tasks in comparison to relatively proficient performance in some other cognitive domains such as language and face processing. Individuals with partial genetic deletions within the WS critical region (WSCR) have provided insigh...

  3. 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...

  4. 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.

  5. 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...... that visuo-spatial working memory can simply be dissociated into visual and spatial sub-components....

  6. Emerging and developing multiplicative structure in students’ visuospatial representations: Four key configuration types

    OpenAIRE

    Finesilver, Carla

    2017-01-01

    Visuospatial representations of quantities and their relations are widely used to support the understanding of basic arithmetic, including multiplicative relationships. These include drawn imagery and concrete manipulatives. This paper defines four particular configurations of nonstandard representation according to the spatial organization of their visual elements. These are: unit containers, unit arrays, array-container blends, and number containers, all of which have been observed to suppo...

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

    OpenAIRE

    Toril, Pilar; José M. Reales; 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 ...

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

    OpenAIRE

    Pilar eToril; José M. eReales; Julia eMayas; Soledad eBallesteros

    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 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 sign...

  9. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Age-related declines in visuospatial working memory correlate with deficits in explicit motor sequence learning.

    Science.gov (United States)

    Bo, J; Borza, V; Seidler, R D

    2009-11-01

    Numerous studies have shown that older adults exhibit deficits in motor sequence learning, but the mechanisms underlying this effect remain unclear. Our recent work has shown that visuospatial working-memory capacity predicts the rate of motor sequence learning and the length of motor chunks formed during explicit sequence learning in young adults. In the current study, we evaluate whether age-related deficits in working memory explain the reduced rate of motor sequence learning in older adults. We found that older adults exhibited a correlation between visuospatial working-memory capacity and motor sequence chunk length, as we observed previously in young adults. In addition, older adults exhibited an overall reduction in both working-memory capacity and motor chunk length compared with that of young adults. However, individual variations in visuospatial working-memory capacity did not correlate with the rate of learning in older adults. These results indicate that working memory declines with age at least partially explain age-related differences in explicit motor sequence learning.

  11. Beyond heritability: neurotransmitter genes differentially modulate visuospatial attention and working memory.

    Science.gov (United States)

    Parasuraman, Raja; Greenwood, Pamela M; Kumar, Reshma; Fossella, John

    2005-03-01

    A cued, visuospatial attention task and a working memory task were administered to 89 healthy adults genotyped for a T-to-C polymorphism in CHRNA4, a nicotinic receptor subunit gene. Increasing gene dose of the C allele of the CHRNA4 gene (i.e., no C alleles, one C allele, two C alleles) was associated with increased reaction time (RT) benefits of valid attentional cuing and reduced RT costs of invalid cues, but was not associated with working memory performance. In a second experiment, 103 healthy persons were genotyped for a G-to-A polymorphism of the dopamine beta-hydroxylase (DBH) gene. Increasing gene dose of the G allele of the DBH gene was associated with increased working memory accuracy at a high memory load. However, there was no consistent association between the DBH gene and visuospatial attention. Thus, a double dissociation was observed, with visuospatial attention associated with CHRNA4 but not the DBH gene and, conversely, working memory associated with the DBH gene but not CHRNA4. The results show that normal allelic variations in single neurotransmitter genes modulate individual differences in processing components of cognitive functions in healthy individuals.

  12. 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

    2017-06-01

    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. © 2016 The British Psychological Society.

  13. Influence of Cognitive Functioning on Age-Related Performance Declines in Visuospatial Sequence Learning

    Science.gov (United States)

    Krüger, Melanie; Hinder, Mark R.; Puri, Rohan; Summers, Jeffery J.

    2017-01-01

    Objectives: The aim of this study was to investigate how age-related performance differences in a visuospatial sequence learning task relate to age-related declines in cognitive functioning. Method: Cognitive functioning of 18 younger and 18 older participants was assessed using a standardized test battery. Participants then undertook a perceptual visuospatial sequence learning task. Various relationships between sequence learning and participants’ cognitive functioning were examined through correlation and factor analysis. Results: Older participants exhibited significantly lower performance than their younger counterparts in the sequence learning task as well as in multiple cognitive functions. Factor analysis revealed two independent subsets of cognitive functions associated with performance in the sequence learning task, related to either the processing and storage of sequence information (first subset) or problem solving (second subset). Age-related declines were only found for the first subset of cognitive functions, which also explained a significant degree of the performance differences in the sequence learning task between age-groups. Discussion: The results suggest that age-related performance differences in perceptual visuospatial sequence learning can be explained by declines in the ability to process and store sequence information in older adults, while a set of cognitive functions related to problem solving mediates performance differences independent of age. PMID:28626442

  14. Vocabulary abilities of children with Williams syndrome: strengths, weaknesses, and relation to visuospatial construction ability.

    Science.gov (United States)

    Mervis, Carolyn B; John, Angela E

    2008-08-01

    This project was designed to identify relative strengths and weaknesses in vocabulary ability for children with Williams syndrome (WS) and to demonstrate the importance of stringent matching criteria for cross-group comparisons. Children with WS and typically developing (TD) children completed standardized assessments of intellectual and language ability. Children with WS also completed a visuospatial construction ability assessment. Study 1: Concrete and relational vocabulary standard scores were significantly lower for 5- to 7-year-olds with WS than for TD children. Children with WS earned significantly higher standard scores for concrete than for relational vocabulary. When groups were stringently matched for relational vocabulary size, children with WS did not evidence a specific weakness in spatial vocabulary. Study 2: Standard scores for relational vocabulary were similar to those for visuospatial construction ability for 5- to 7-year-olds with WS. Study 3: Nine- to 11-year-olds with WS demonstrated very limited relational vocabulary ability; relational vocabulary ability at 5-7 years was highly correlated with later relational language ability. Concrete vocabulary is a relative strength for children with WS; relational vocabulary ability is very limited and is at about the level of visuospatial construction ability. Accurate determination of group comparison results depends on stringent group matching.

  15. Covert visuospatial attention orienting in a brain-computer interface for amyotrophic lateral sclerosis patients.

    Science.gov (United States)

    Marchetti, Mauro; Piccione, Francesco; Silvoni, Stefano; Gamberini, Luciano; Priftis, Konstantinos

    2013-06-01

    Brain-computer interfaces (BCIs) allow people to control devices by translating brain signals into commands. BCIs represent a concrete solution with regard to communication and motor control disabilities of patients with amyotrophic lateral sclerosis (ALS). Most of the BCIs rely on visual interfaces in which patients must move their eyes to achieve efficient BCI control. This fact represents a limitation of BCI use in ALS patients who are in the final stages of the disease. We aimed to improve visual interfaces for ALS patients to control the movement of a cursor on a monitor by orienting their covert visuospatial attention (i.e., orienting without eye movements). A total of 10 ALS patients with different levels of impairment used 2 new visual interfaces in an event-related potential (ERP)-based BCI. In the first interface, they were required to use exogenous visuospatial attention orienting (VAO), whereas in the second interface, they were required to use endogenous VAO. . ALS patients were able to use the 2 interfaces for controlling the ERP-based BCI system in real time. Nevertheless, better target classification and information transfer rate were associated with the interface that was based on endogenous VAO. ALS patients can exploit their covert VAO to control a BCI that does not require eye movements. The implementation of endogenous VAO in the design of covert visuospatial attention-based interfaces seems to be suitable for designing more ergonomic and efficient BCIs for ALS patients with impaired eye movements.

  16. 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.

  17. Increased Alpha-Rhythm Dynamic Range Promotes Recovery from Visuospatial Neglect: A Neurofeedback Study

    Directory of Open Access Journals (Sweden)

    Tomas Ros

    2017-01-01

    Full Text Available Despite recent attempts to use electroencephalogram (EEG neurofeedback (NFB as a tool for rehabilitation of motor stroke, its potential for improving neurological impairments of attention—such as visuospatial neglect—remains underexplored. It is also unclear to what extent changes in cortical oscillations contribute to the pathophysiology of neglect, or its recovery. Utilizing EEG-NFB, we sought to causally manipulate alpha oscillations in 5 right-hemisphere stroke patients in order to explore their role in visuospatial neglect. Patients trained to reduce alpha oscillations from their right posterior parietal cortex (rPPC for 20 minutes daily, over 6 days. Patients demonstrated successful NFB learning between training sessions, denoted by improved regulation of alpha oscillations from rPPC. We observed a significant negative correlation between visuospatial search deficits (i.e., cancellation test and reestablishment of spontaneous alpha-rhythm dynamic range (i.e., its amplitude variability. Our findings support the use of NFB as a tool for investigating neuroplastic recovery after stroke and suggest reinstatement of intact parietal alpha oscillations as a promising target for reversing attentional deficits. Specifically, we demonstrate for the first time the feasibility of EEG-NFB in neglect patients and provide evidence that targeting alpha amplitude variability might constitute a valuable marker for clinical symptoms and self-regulation.

  18. Vocabulary Abilities of Children with Williams Syndrome: Strengths, Weaknesses, and Relation to Visuospatial Construction Ability

    Science.gov (United States)

    Mervis, Carolyn B.; John, Angela E.

    2008-01-01

    Purpose This project was designed to identify relative strengths and weaknesses in vocabulary ability for children with Williams syndrome (WS) and to demonstrate the importance of stringent matching criteria for cross-group comparisons. Methods Children with WS and typically developing (TD) children completed standardized assessments of intellectual and language ability. Children with WS also completed a visuospatial construction ability assessment. Results Study 1: Concrete and relational vocabulary standard scores were significantly lower for 5 – 7-year-olds with WS than for TD children. Children with WS earned significantly higher standard scores for concrete than for relational vocabulary. When groups were stringently matched for relational vocabulary size, children with WS did not evidence a specific weakness in spatial vocabulary. Study 2: Standard scores for relational vocabulary were similar to those for visuospatial construction ability for 5 – 7-year-olds with WS. Study 3: 9 – 11-year-olds with WS demonstrated very limited relational vocabulary ability; relational vocabulary ability at 5 – 7 years was highly correlated with later relational language ability. Conclusions Concrete vocabulary is a relative strength for children with WS; relational vocabulary ability is very limited and is at about the level of visuospatial construction ability. Accurate determination of group comparison results depends on stringent group matching. PMID:18658065

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

    Directory of Open Access Journals (Sweden)

    Christine Beauchene

    Full Text Available 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.

  20. Different effects of executive and visuospatial working memory on visual consciousness.

    Science.gov (United States)

    De Loof, Esther; Poppe, Louise; Cleeremans, Axel; Gevers, Wim; Van Opstal, Filip

    2015-11-01

    Consciousness and working memory are two widely studied cognitive phenomena. Although they have been closely tied on a theoretical and neural level, empirical work that investigates their relation is largely lacking. In this study, the relationship between visual consciousness and different working memory components is investigated by using a dual-task paradigm. More specifically, while participants were performing a visual detection task to measure their visual awareness threshold, they had to concurrently perform either an executive or visuospatial working memory task. We hypothesized that visual consciousness would be hindered depending on the type and the size of the load in working memory. Results showed that maintaining visuospatial content in working memory hinders visual awareness, irrespective of the amount of information maintained. By contrast, the detection threshold was progressively affected under increasing executive load. Interestingly, increasing executive load had a generic effect on detection speed, calling into question whether its obstructing effect is specific to the visual awareness threshold. Together, these results indicate that visual consciousness depends differently on executive and visuospatial working memory.

  1. Visuospatial working memory impairment in current and previous ecstasy/polydrug users.

    Science.gov (United States)

    Fisk, John E; Montgomery, Catharine; Hadjiefthyvoulou, Florentia

    2011-01-01

    Previous research suggests that ecstasy users are impaired in processing visuospatial information. However, for the most part, the deficits observed appear to involve the recall and recognition of complex visual and geometric patterns. The present research sought to determine whether ecstasy use was associated with deficits in serial spatial recall and visuospatial working memory (VSWM). Thirty-eight current ecstasy/polydrug users, 16 previous ecstasy/polydrug users and 52 non ecstasy users completed serial simple spatial recall and VSWM tasks. Both the current and previous users of ecstasy exhibited deficits on the VSWM task. Following controls for group differences in aspects of cannabis and cocaine use, the overall group effect fell to just below statistical significance. However, the difference contrast comparing users with nonusers continued to demonstrate a statistically significant ecstasy-related VSWM deficit. Ecstasy users were impaired in processing visuospatial information especially under conditions of high processing demand. The results are consistent with ecstasy-related impairment either in the short-term posterior parietal and occipital area store or the dorsolateral prefrontal cortex processes, which augment it under conditions of higher processing demands. Further research is needed to pinpoint the actual source of the ecstasy/polydrug-related VSWM deficits that have been observed here and elsewhere. Copyright © 2011 John Wiley & Sons, Ltd.

  2. 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.

  3. Increased Alpha-Rhythm Dynamic Range Promotes Recovery from Visuospatial Neglect: A Neurofeedback Study

    Science.gov (United States)

    Michela, Abele; Bellman, Anne; Vuadens, Philippe; Saj, Arnaud; Vuilleumier, Patrik

    2017-01-01

    Despite recent attempts to use electroencephalogram (EEG) neurofeedback (NFB) as a tool for rehabilitation of motor stroke, its potential for improving neurological impairments of attention—such as visuospatial neglect—remains underexplored. It is also unclear to what extent changes in cortical oscillations contribute to the pathophysiology of neglect, or its recovery. Utilizing EEG-NFB, we sought to causally manipulate alpha oscillations in 5 right-hemisphere stroke patients in order to explore their role in visuospatial neglect. Patients trained to reduce alpha oscillations from their right posterior parietal cortex (rPPC) for 20 minutes daily, over 6 days. Patients demonstrated successful NFB learning between training sessions, denoted by improved regulation of alpha oscillations from rPPC. We observed a significant negative correlation between visuospatial search deficits (i.e., cancellation test) and reestablishment of spontaneous alpha-rhythm dynamic range (i.e., its amplitude variability). Our findings support the use of NFB as a tool for investigating neuroplastic recovery after stroke and suggest reinstatement of intact parietal alpha oscillations as a promising target for reversing attentional deficits. Specifically, we demonstrate for the first time the feasibility of EEG-NFB in neglect patients and provide evidence that targeting alpha amplitude variability might constitute a valuable marker for clinical symptoms and self-regulation. PMID:28529806

  4. 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. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. 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. PMID:23890692

  6. 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.

  7. [Visuospatial context processing in untreated schizophrenic patients and relation to disorganization syndrome].

    Science.gov (United States)

    Longevialle-Hénin, R; Bourdel, M-C; Willard, D; Lôo, H; Olié, J-P; Poirier, M-F; Krebs, M-O; Amado, I

    2005-01-01

    Previous studies on schizophrenia have suggested that context-processing disturbances were one of the core cognitive deficits present in schizophrenia. Schizophrenic patients have a failure either of inhibition strategy and maintenance of visuospatial information (25) in condition of contextual interference. In the present study, we explored the performances of untreated schizophrenic patients with 2 tasks exploring detection and long term retention of complex visual features and field dependence-independence tasks were selected. These abilities involve temporary maintenance of visuospatial information and executive functioning of visual working memory system. Several studies have shown that cognitive deficit may depend on schizophrenic symptomatology. However results remain controversial in determining the specific influence of negative and positive symptomatologies as well as clinical disorganization. Our goal was to explore the processing of spatial context and its relation to disorganized syndrome. This study was approved by the local ethic committee. Thirty-six schizophrenic patients were included according to DSM IV criteria (19 neuroleptic naïve, 17 unmedicated patients during more than 3 months). Thirty-six healthy controls were matched to patients for age, gender and level of education. Absence of axis 1 pathology was attested for controls with SCID-NP. Current symptomatology was evaluated by the Positive and Negative Syndrome Scale (PANSS) (14). Clinical disorganisation was evaluated with the disorganisation score established upon a factorial analysis of PANSS by Lepine and Lançon. Items selected to distinguish the disorganised group were abstraction, disorganization, orientation, and attention. Two tasks of embedded figures were administered individually to patients and controls. The Faverge task (Research of Figures-RF) (10) evaluates the ability to recognize the target from spatial complex geometrical figures. The Group Embedded Figure Task (GEFT

  8. Enhancement of Afterimage Colors by Surrounding Contours

    Directory of Open Access Journals (Sweden)

    Takao Sato

    2011-05-01

    Full Text Available Presenting luminance contours surrounding the adapted areas in test phase enhances color afterimages in both duration and color appearance. The presence of surrounding contour is crucial to some color phenomenon such as van Lier's afterimage, but the contour-effect itself has not been seriously examined. In this paper, we compared the contour-effect to color afterimages and to actually colored patches to examine the nature of color information subserving color-aftereffect. In the experiment, observers were adapted for 1 sec to a small colored square (red, green, yellow, or blue presented on a gray background. Then, a test field either with or without surrounding contour was presented. Observers matched the color of a test-patch located near the afterimage to the color of afterimage. It was found that the saturation of negative afterimage was almost doubled by the presence of surrounding contours. There was no effect of luminance contrast or polarity of contours. In contrast, no enhancement of saturation by surrounding contours was observed for actually colored patches even though the colors of patches were equalized to that of afterimage without contours. This dissociation in the contour-effect demonstrates the crucial difference between the color information for aftereffects and for ordinary bottom-up color perception.

  9. Comparative Analysis of Termiteria and Surrounding Soil

    African Journals Online (AJOL)

    Magashi

    2013-06-01

    Jun 1, 2013 ... Variations in the properties of termitaria and their surrounding soil properties within the University of ... and animals. Keywords: AAS, Heavy metals, Makurdi, Soils, Termites. INTRODUCTION. Termites are eusocial insects that live in colonies composed of individuals from ... Also, termite's effects resulted in.

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

    African Journals Online (AJOL)

    cntaganda

    Abstract. An assessment of fuel wood situation and the contribution of agroforestry and woodlot resources to the supply of household fuel wood requirements were carried out in ten villages surrounding Nyamure former refugee camp, Nyanza District in the Southern. Province. A total of 158 households were surveyed in ...

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

    African Journals Online (AJOL)

    An assessment of fuel wood situation and the contribution of agroforestry and woodlot resources to the supply of household fuel wood requirements were carried out in ten villages surrounding Nyamure former refugee camp, Nyanza District in the Southern Province. A total of 158 households were surveyed in February ...

  12. Surround-gated vertical nanowire quantum dots

    NARCIS (Netherlands)

    Van Weert, M.H.M.; Den Heijer, M.; Van Kouwen, M.P.; Algra, R.E.; Bakkers, E.P.A.M.; Kouwenhoven, L.P.; Zwiller, V.

    2010-01-01

    We report voltage dependent photoluminescence experiments on single indium arsenide phosphide (InAsP) quantum dots embedded in vertical surround-gated indium phosphide (InP) nanowires. We show that by tuning the gate voltage, we can access different quantum dot charge states. We study the

  13. Religion's relationship with social boundaries surrounding gender ...

    African Journals Online (AJOL)

    This paper examines the religious persuasion on the social boundaries surrounding gender. Gender has been a contentious issue that is associated with segregation, marginalization and differentiation between men and women. In the light of this, scholars' views on the subject matter were considered. Thus, this indicates ...

  14. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Reduced prefrontal efficiency for visuospatial working memory in attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Bédard, Anne-Claude V; Newcorn, Jeffrey H; Clerkin, Suzanne M; Krone, Beth; Fan, Jin; Halperin, Jeffrey M; Schulz, Kurt P

    2014-09-01

    Visuospatial working memory impairments have been implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD). However, most ADHD research has focused on the neural correlates of nonspatial mnemonic processes. This study examined brain activation and functional connectivity for visuospatial working memory in youth with and without ADHD. Twenty-four youth with ADHD and 21 age- and sex-matched healthy controls were scanned with functional magnetic resonance imaging while performing an N-back test of working memory for spatial position. Block-design analyses contrasted activation and functional connectivity separately for high (2-back) and low (1-back) working memory load conditions versus the control condition (0-back). The effect of working memory load was modeled with linear contrasts. The 2 groups performed comparably on the task and demonstrated similar patterns of frontoparietal activation, with no differences in linear gains in activation as working memory load increased. However, youth with ADHD showed greater activation in the left dorsolateral prefrontal cortex (DLPFC) and left posterior cingulate cortex (PCC), greater functional connectivity between the left DLPFC and left intraparietal sulcus, and reduced left DLPFC connectivity with left midcingulate cortex and PCC for the high load contrast compared to controls (p 100 voxels). Reanalysis using a more conservative statistical approach (p 100 voxels) yielded group differences in PCC activation and DLPFC-midcingulate connectivity. Youth with ADHD show decreased efficiency of DLPFC for high-load visuospatial working memory and greater reliance on posterior spatial attention circuits to store and update spatial position than healthy control youth. Findings should be replicated in larger samples. Copyright © 2014 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  17. Working memory and visuospatial deficits correlate with oculomotor control in children with fetal alcohol spectrum disorder.

    Science.gov (United States)

    Paolozza, Angelina; Rasmussen, Carmen; Pei, Jacqueline; Hanlon-Dearman, Ana; Nikkel, Sarah M; Andrew, Gail; McFarlane, Audrey; Samdup, Dawa; Reynolds, James N

    2014-04-15

    Previous studies have demonstrated that children with Fetal Alcohol Spectrum Disorder (FASD) exhibit deficits in measures of eye movement control that probe aspects of visuospatial processing and working memory. The goal of the present study was to examine, in a large cohort of children with FASD, prenatal alcohol exposure (PAE) but not FASD, and typically developing control children, the relationship between performance in eye movement tasks and standardized psychometric tests that assess visuospatial processing and working memory. Participants for this dataset were drawn from a large, multi-site investigation, and included children and adolescents aged 5-17 years diagnosed with an FASD (n=71), those with PAE but no clinical FASD diagnosis (n=20), and typically developing controls (n=111). Participants completed a neurobehavioral test battery and a series of saccadic eye movement tasks. The FASD group performed worse than controls on the psychometric and eye movement measures of working memory and visuospatial skills. Within the FASD group, digit recall, block recall, and animal sorting were negatively correlated with sequence errors on the memory-guided task, and arrows was negatively correlated with prosaccade endpoint error. There were no significant correlations in the control group. These data suggest that psychometric tests and eye movement control tasks may assess similar domains of cognitive function, and these assessment tools may be measuring overlapping brain regions damaged due to prenatal alcohol exposure. The results of this study demonstrate that eye movement control tasks directly relate to outcome measures obtained with psychometric tests and are able to assess multiple domains of cognition simultaneously, thereby allowing for an efficient and accurate assessment. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. 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.

  19. Chronic alcohol consumption impairs visuo-spatial associative memory in periadolescent rhesus monkeys.

    Science.gov (United States)

    Crean, Rebecca D; Vandewater, Sophia A; Katner, Simon N; Huitron-Resendiz, Salvador; Taffe, Michael A

    2011-03-01

    Alcohol abuse in the adult is often preceded by high alcohol consumption during adolescence. Profound changes in brain structure and function occur during this developmental period, therefore alcohol may impact essential cognitive skill development during the formal educational years. The objective of this study was to determine if chronic oral alcohol intake slows acquisition and performance of cognitive tasks in male adolescent rhesus monkeys. Treatment groups (Alcohol, N=4; Control, N=3) were evaluated on bimanual dexterity and tests of visuo-spatial memory and learning adapted from the Cambridge Neuropsychological Test Automated Battery. Animals were trained daily in 30 min sessions and had subsequent access to alcohol/Tang® solutions (Alcohol group) or Tang® only (Control group) Monday through Friday for 11 months. Recordings of brainstem auditory evoked potentials (BSAEP) were conducted periodically before and during the chronic drinking. Chronic alcohol drinking (ave of 1.78 g/kg alcohol per session) impaired behavioral performance assessed ∼22 h after the prior drinking session. The Alcohol group required more trials than the Control group to reach criterion on the visuo-spatial memory task and showed increased sensitivity to trial difficulty and retention interval. Alcohol animals also had slowed initial acquisition of the bimanual task. The latency of P4 and P5 BSAEP peaks were also delayed in the Alcohol group. Chronic alcohol consumption impaired the acquisition and performance of a spatial memory task and disrupted brainstem auditory processing, thus these results show that repeated alcohol exposure in adolescence interferes with a range of brain functions including complex visuo-spatial mnemonic processing. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  20. Pregnancy-related anxiety and depressive symptoms are associated with visuospatial working memory errors during pregnancy.

    Science.gov (United States)

    Kataja, E-L; Karlsson, L; Huizink, A C; Tolvanen, M; Parsons, C; Nolvi, S; Karlsson, H

    2017-08-15

    Cognitive deficits, especially in memory and concentration, are often reported during pregnancy. Similar cognitive dysfunctions can also occur in depression and anxiety. To date, few studies have investigated the associations between cognitive deficits and psychiatric symptoms during pregnancy. This field is of interest because maternal cognitive functioning, and particularly its higher-order aspects are related to maternal well-being and caregiving behavior, as well as later child development. Pregnant women (N =230), reporting low (n =87), moderate (n =97), or high (n =46) levels of depressive, general anxiety and/or pregnancy-related anxiety symptoms (assessed repeatedly with EPDS, SCL-90/anxiety subscale, PRAQ-R2, respectively) were tested in mid-pregnancy for their cognitive functions. A computerized neuropsychological test battery was used. Pregnant women with high or moderate level of psychiatric symptoms had significantly more errors in visuospatial working memory/executive functioning task than mothers with low symptom level. Depressive symptoms throughout pregnancy and concurrent pregnancy-related anxiety symptoms were significant predictors of the performance in the task. General anxiety symptoms were not related to visuospatial working memory. Cognitive functions were evaluated only at one time-point during pregnancy precluding causal conclusions. Maternal depressive symptoms and pregnancy-related anxiety symptoms were both associated with decrements in visuospatial working memory/executive functioning. Depressive symptoms seem to present more stable relationship with cognitive deficits, while pregnancy-related anxiety was associated only concurrently. Future studies could investigate, how stable these cognitive differences are, and whether they affect maternal ability to deal with demands of pregnancy and later parenting. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. 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

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

    Directory of Open Access Journals (Sweden)

    Chiara Banfi

    Full Text Available 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

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

    OpenAIRE

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

    2014-01-01

    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 ye...

  4. Beyond Heritability: Neurotransmitter Genes Differentially Modulate Visuospatial Attention and Working Memory

    OpenAIRE

    Parasuraman, Raja; Pamela M Greenwood; Kumar, Reshma; Fossella, John

    2005-01-01

    A cued, visuospatial attention task and a working memory task were administered to 89 healthy adults genotyped for a T-to-C polymorphism in CHRNA4, a nicotinic receptor subunit gene. Increasing gene dose of the C allele of the CHRNA4 gene (i.e., no C alleles, one C allele, two C alleles) was associated with increased reaction time (RT) benefits of valid attentional cuing and reduced RT costs of invalid cues, but was not associated with working memory performance. In a second experiment, 103 h...

  5. Vestibular involvement in cognition: Visuospatial ability, attention, executive function, and memory.

    Science.gov (United States)

    Bigelow, Robin T; Agrawal, Yuri

    2015-01-01

    A growing body of literature suggests the inner ear vestibular system has a substantial impact on cognitive function. The strongest evidence exists in connecting vestibular function to the cognitive domain of visuospatial ability, which includes spatial memory, navigation, mental rotation, and mental representation of three-dimensional space. Substantial evidence also exists suggesting the vestibular system has an impact on attention and cognitive processing ability. The cognitive domains of memory and executive function are also implicated in a number of studies. We will review the current literature, discuss possible causal links between vestibular dysfunction and cognitive performance, and suggest areas of future research.

  6. Identification of β-SiC surrounded by relatable surrounding diamond ...

    Indian Academy of Sciences (India)

    Abstract. It is difficult to detect β-SiC using micro-Raman scattering, if it is surrounded by carbon medium. Here, β-SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman surface phonons. In this study, diamond/β-SiC nanocomposite thin film system is considered in ...

  7. Identification of β-SiC surrounded by relatable surrounding diamond ...

    Indian Academy of Sciences (India)

    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 ...

  8. 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.

  9. Near-Independent Capacities and Highly Constrained Output Orders in the Simultaneous Free Recall of Auditory-Verbal and Visuo-Spatial Stimuli

    Science.gov (United States)

    Cortis Mack, Cathleen; Dent, Kevin; Ward, Geoff

    2018-01-01

    Three experiments examined the immediate free recall (IFR) of auditory-verbal and visuospatial materials from single-modality and dual-modality lists. In Experiment 1, we presented participants with between 1 and 16 spoken words, with between 1 and 16 visuospatial dot locations, or with between 1 and 16 words "and" dots with synchronized…

  10. 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

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

    Science.gov (United States)

    Poletti, Michele

    2017-01-01

    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.

  12. Visuospatial working memory in very preterm and term born children—Impact of age and performance

    Directory of Open Access Journals (Sweden)

    I. Mürner-Lavanchy

    2014-07-01

    Full Text Available 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.

  13. Visuo-spatial representations of the alphabet in synaesthetes and non-synaesthetes.

    Science.gov (United States)

    Jonas, Clare N; Taylor, Alisdair J G; Hutton, Sam; Weiss, Peter H; Ward, Jamie

    2011-09-01

    Visuo-spatial representations of the alphabet (so-called 'alphabet forms') may be as common as other types of sequence-space synaesthesia, but little is known about them or the way they relate to implicit spatial associations in the general population. In the first study, we describe the characteristics of a large sample of alphabet forms visualized by synaesthetes. They most often run from left to right and have salient features (e.g., bends, breaks) at particular points in the sequence that correspond to chunks in the 'Alphabet Song' and at the alphabet mid-point. The Alphabet Song chunking suggests that the visuo-spatial characteristics are derived, at least in part, from those of the verbal sequence learned earlier in life. However, these synaesthetes are no faster at locating points in the sequence (e.g., what comes before/after letter X?) than controls. They tend to be more spatially consistent (measured by eye tracking) and letters can act as attentional cues to left/right space in synaesthetes with alphabet forms (measured by saccades), but not in non-synaesthetes. This attentional cueing suggests dissociation between numbers (which reliably act as attentional cues in synaesthetes and non-synaesthetes) and letters (which act as attentional cues in synaesthetes only). ©2011 The British Psychological Society.

  14. Visuospatial skills and their association with math performance in girls with fragile X or Turner syndrome.

    Science.gov (United States)

    Mazzocco, Michèle M M; Singh Bhatia, Neha; Lesniak-Karpiak, Katarzyna

    2006-04-01

    The present study was designed to assess object identification ("what") and location ("where") skills among girls with fragile X or Turner syndrome and girls with neither disorder. Participants completed standardized subtests of visual perception and tasks of visuospatial "what" and "where" memory. Girls with fragile X had average performance on most object identification tasks, yet 53% failed to accurately recreate the gestalt of a design during the "where" memory task. Fewer than 7% of girls in the Turner or comparison group made this error. Girls with Turner syndrome had lower scores and longer response times on object perception tasks and had poorer recall of location for internal features of the design on the "where" memory task, relative to girls in the comparison or fragile X group. When limiting analyses to IQ-matched samples, correlations between math and visual perception tasks emerged, but only for girls with fragile X. These results reflect important differences between two cognitive phenotypes and have implications for the role of visuospatial processing in early math performance.

  15. 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.

  16. 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. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. The underlying structure of visuospatial working memory in children with mathematical learning disability.

    Science.gov (United States)

    Mammarella, Irene C; Caviola, Sara; Giofrè, David; Szűcs, Dénes

    2017-08-18

    This study examined visual, spatial-sequential, and spatial-simultaneous working memory (WM) performance in children with mathematical learning disability (MLD) and low mathematics achievement (LMA) compared with typically developing (TD) children. Groups were matched on reading decoding performance and verbal intelligence. Besides statistical significance testing, we used bootstrap confidence interval estimation and computed effect sizes. Children were individually tested with six computerized tasks, two for each visuospatial WM subcomponent. We found that both MLD and LMA children had low visuospatial WM function in both spatial-simultaneous and spatial-sequential WM tasks. The WM deficit was most expressed in MLD children and less in LMA children. This suggests that WM scores are distributed along a continuum with TD children achieving top scores and MLD children achieving low scores. The theoretical and practical significance of findings is discussed. Statement of Contribution What is already known on this subject? Working memory plays an important role in mathematical achievement. Children with mathematical learning disability (MLD) usually have low working memory resources. Conflicting results have been reported concerning the role of VSWM in individuals with MLD. What the present study adds? Children with different degree of impairment in math achievement and typically developing children were tested. Visual, spatial-sequential, and spatial-simultaneous working memory tasks were examined. Only spatial-sequential and spatial-simultaneous working memory tasks discriminated the two impairments groups. © 2017 The British Psychological Society.

  18. 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.

  19. Probabilistic White Matter Atlases of Human Auditory, Basal Ganglia, Language, Precuneus, Sensorimotor, Visual and Visuospatial Networks.

    Science.gov (United States)

    Figley, Teresa D; Mortazavi Moghadam, Behnoush; Bhullar, Navdeep; Kornelsen, Jennifer; Courtney, Susan M; Figley, Chase R

    2017-01-01

    Background: Despite the popularity of functional connectivity analyses and the well-known topology of several intrinsic cortical networks, relatively little is known about the white matter regions (i.e., structural connectivity) underlying these networks. In the current study, we have therefore performed fMRI-guided diffusion tensor imaging (DTI) tractography to create probabilistic white matter atlases for eight previously identified functional brain networks, including the Auditory, Basal Ganglia, Language, Precuneus, Sensorimotor, Primary Visual, Higher Visual and Visuospatial Networks. Methods: Whole-brain diffusion imaging data were acquired from a cohort of 32 healthy volunteers, and were warped to the ICBM template using a two-stage, high-dimensional, non-linear spatial normalization procedure. Deterministic tractography, with fractional anisotropy (FA) ≥0.15 and deviation angle matter atlases (i.e., for each tract and each network as a whole) were saved as NIFTI images in stereotaxic ICBM coordinates, and have been added to the UManitoba-JHU Functionally-Defined Human White Matter Atlas (http://www.nitrc.org/projects/uofm_jhu_atlas/). Conclusion: To the best of our knowledge, this work represents the first attempt to comprehensively identify and map white matter connectomes for the Auditory, Basal Ganglia, Language, Precuneus, Sensorimotor, Primary Visual, Higher Visual and Visuospatial Networks. Therefore, the resulting probabilistic atlases represent a unique tool for future neuroimaging studies wishing to ascribe voxel-wise or ROI-based changes (i.e., in DTI or other quantitative white matter imaging signals) to these functional brain networks.

  20. 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. PMID:27199723

  1. Training with differential outcomes enhances discriminative learning and visuospatial recognition memory in children born prematurely.

    Science.gov (United States)

    Martínez, Lourdes; Marí-Beffa, Paloma; Roldán-Tapia, Dolores; Ramos-Lizana, Julio; Fuentes, Luis J; Estévez, Angeles F

    2012-01-01

    Previous studies have demonstrated that discriminative learning is facilitated when a particular outcome is associated with each relation to be learned. When this training procedure is applied (the differential outcome procedure; DOP), learning is faster and more accurate than when the more common non-differential outcome procedure is used. This enhancement of accuracy and acquisition has been called the differential outcome effect (DOE). Our primary purpose in the present study was to explore the DOE in children born with great prematurity performing a discriminative learning task (Experiment 1) or a delayed visuospatial recognition task (Experiment 2). In Experiment 1, participants showed a faster learning and a better performance when differential outcomes were used. In Experiment 2, a significant DOE was also observed. That is, premature children performed the visuospatial recognition task better when they received differential outcomes following their correct responses. By contrast, the overall performance of full-term children was similar in both differential and non-differential conditions. These results are first to show that the DOP can enhance learning of conditional discriminations and recognition memory in children born prematurely with very low birth-weight. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. 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.

  3. The effect of the augmentation of cholinergic neurotransmission by nicotine on EEG indices of visuospatial attention.

    Science.gov (United States)

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

    2014-03-01

    The cholinergic system has been implicated in visuospatial attention but the exact role remains unclear. In visuospatial attention, bias refers to neuronal signals that modulate the sensitivity of sensory cortex, while disengagement refers to the decoupling of attention making reorienting possible. In the current study we investigated the effect of facilitating cholinergic neurotransmission by nicotine (Nicorette Freshmint 2mg, polacrilex chewing gum) on behavioral and electrophysiological indices of bias and disengagement. Sixteen non-smoking participants performed in a Visual Spatial Cueing (VSC) task while EEG was recorded. A randomized, single-blind, crossover design was implemented. Based on the scarce literature, it was expected that nicotine would specifically augment disengagement related processing, especially manifest as an increase of the modulation of the Late Positive Deflection (LPD) by validity of cueing. No effect was expected on bias related components (cue-locked: EDAN, LDAP; target-locked: P1 and N1 modulations). Results show weak indications for a reduction of the reaction time validity effect by nicotine, but only for half of the sample in which the validity effect on the pretest was largest. Nicotine reduced the result of bias as indexed by a reduced P1 modulation by validity, especially in subjects with strong peripheral responses to nicotine. Nicotine did not affect ERP manifestations of the directing of bias (EDAN, LDAP) or disengagement (LPD). Copyright © 2013 Elsevier B.V. All rights reserved.

  4. The role of prefrontal cortex in visuo-spatial planning: A repetitive TMS study.

    Science.gov (United States)

    Basso, Demis; Lotze, Martin; Vitale, Lavinia; Ferreri, Florinda; Bisiacchi, Patrizia; Olivetti Belardinelli, Marta; Rossini, Paolo Maria; Birbaumer, Niels

    2006-05-01

    The visuo-spatial planning process is based on an "opportunistic" combination of heuristics and strategies, carried out in small units during the execution of plans. In order to investigate the functional role of the prefrontal cortex in heuristic switching, 42 healthy controls performed a labyrinth crossing task (the Maps Test). During this computerized version of the Travelling Salesperson Problem, subjects had to decide which order of locations optimizes total travel time and distance. This task was performed with and without 1 Hz repetitive transcranial magnetic stimulation (rTMS), which exerts an inhibitory action on the targeted area, applied during the task over bilateral frontal sites (active stimulation) and parieto-occipital site (sham stimulation). Only repetitive bilateral rTMS over F3 and F4 significantly decreased the number of strategies with changes of heuristics, and increased the number of movements required to solve the task. This behaviour contrasts with the performance of healthy subjects in the planning task, but is consistent with the performance of frontal traumatic brain injury patients. The results indicate that, in a visuo-spatial problem-solving task, the prefrontal cortex is involved in the switching between heuristics during the execution of a plan.

  5. 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.

  6. 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. PMID:27378994

  7. Investigating neural efficiency in the visuo-spatial domain: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Ilona Lipp

    Full Text Available The neural efficiency hypothesis postulates an inverse relationship between intelligence and brain activation. Previous research suggests that gender and task modality represent two important moderators of the neural efficiency phenomenon. Since most of the existing studies on neural efficiency have used ERD in the EEG as a measure of brain activation, the central aim of this study was a more detailed analysis of this phenomenon by means of functional MRI. A sample of 20 males and 20 females, who had been screened for their visuo-spatial intelligence, was confronted with a mental rotation task employing an event-related approach. Results suggest that less intelligent individuals show a stronger deactivation of parts of the default mode network, as compared to more intelligent people. Furthermore, we found evidence of an interaction between task difficulty, intelligence and gender, indicating that more intelligent females show an increase in brain activation with an increase in task difficulty. These findings may contribute to a better understanding of the neural efficiency hypothesis, and possibly also of gender differences in the visuo-spatial domain.

  8. 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

  9. Anticlockwise or clockwise? A dynamic Perception-Action-Laterality model for directionality bias in visuospatial functioning.

    Science.gov (United States)

    Karim, A K M Rezaul; Proulx, Michael J; Likova, Lora T

    2016-09-01

    Orientation bias and directionality bias are two fundamental functional characteristics of the visual system. Reviewing the relevant literature in visual psychophysics and visual neuroscience we propose here a three-stage model of directionality bias in visuospatial functioning. We call this model the 'Perception-Action-Laterality' (PAL) hypothesis. We analyzed the research findings for a wide range of visuospatial tasks, showing that there are two major directionality trends in perceptual preference: clockwise versus anticlockwise. It appears these preferences are combinatorial, such that a majority of people fall in the first category demonstrating a preference for stimuli/objects arranged from left-to-right rather than from right-to-left, while people in the second category show an opposite trend. These perceptual biases can guide sensorimotor integration and action, creating two corresponding turner groups in the population. In support of PAL, we propose another model explaining the origins of the biases - how the neurogenetic factors and the cultural factors interact in a biased competition framework to determine the direction and extent of biases. This dynamic model can explain not only the two major categories of biases in terms of direction and strength, but also the unbiased, unreliably biased or mildly biased cases in visuosptial functioning. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Visuospatial cues for reinstating mental models in working memory during interrupted reading.

    Science.gov (United States)

    Schneider, Darryl W; Dixon, Peter

    2009-09-01

    Reading involves constructing a mental representation in long-term working memory of the world described by the text. Disrupting short-term working memory can interfere with the maintenance of mental models (sets of retrieval cues) needed to access these representations, producing detrimental effects on reading time. In two experiments, subjects read passages that included pairs of coreferential sentences interrupted by unrelated text. As in previous research, reading times increased for the first sentence after the interruption, likely reflecting a reinstatement process for mental models in working memory. In the present research, pictures were provided as visuospatial cues to aid the reinstatement process. The interruption effect was found to be smaller with pictures related to the passages than with unrelated pictures (Experiment 1) or titles (Experiment 2); however, both of these effects occurred only for slow readers. The authors hypothesize that slow readers take the time needed to integrate visuospatial information into their mental models, providing more resilient access to long-term working memory.

  11. 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.

  12. Spirit's Surroundings on 'West Spur,' Sol 305

    Science.gov (United States)

    2005-01-01

    This 360-degree panorama shows the terrain surrounding NASA's Mars Exploration Rover Spirit as of the rover's 305th martian day, or sol, (Nov. 11, 2004). At that point, Spirit was climbing the 'West Spur' of the 'Columbia Hills.' The rover had just finished inspecting a rock called 'Lutefisk' and was heading uphill toward an area called 'Machu Picchu.' Spirit used its navigational camera to take the images combined into this mosaic. The rover's location when the images were taken is catalogued as the mission's site 89, position 205. The view is presented here as a cylindrical projection with geometric seam correction.

  13. 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...

  14. Opportunity's Surroundings on Sol 1818 (Vertical)

    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 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  15. Opportunity's Surroundings on Sol 1818 (Polar)

    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 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a polar projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  16. Towards Semantic Understanding of Surrounding Vehicular Maneuvers

    DEFF Research Database (Denmark)

    Kristoffersen, Miklas Strøm; Dueholm, Jacob Velling; Satzoda, Ravi K.

    2016-01-01

    This paper proposes the use of multiple low-cost visual sensors to obtain a surround view of the ego-vehicle for semantic understanding. A multi-perspective view will assist the analysis of naturalistic driving studies (NDS), by automating the task of data reduction of the observed sequences...... is tested on ten sequences of real-world data collected on U. S. highways. The results show the potential use of multiple low-cost visual sensors for semantic understanding around the ego-vehicle....

  17. 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.

  18. 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.

  19. High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

    Science.gov (United States)

    Lobier, Muriel; Palva, J Matias; Palva, Satu

    2018-01-15

    Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Distinct neural substrates of visuospatial and verbal-analytic reasoning as assessed by Raven's Advanced Progressive Matrices

    NARCIS (Netherlands)

    Chen, Zhencai; De Beuckelaer, A.; Wang, Xu; Liu, Jia

    2017-01-01

    Recent studies revealed spontaneous neural activity to be associated with fluid intelligence (gF) which is commonly assessed by Raven’s Advanced Progressive Matrices, and embeds two types of reasoning: visuospatial and verbal-analytic reasoning. With resting-state fMRI data, using global brain

  1. Differential effects of a visuospatial attention task on measures of postural control in young and older adults.

    Science.gov (United States)

    Peterson, Jeffrey J; Keenan, Kevin G

    2017-12-18

    The purpose of this study was to examine the influence of a visuospatial attention task on three measures of postural control in young and older adults. 20 young (19-36  years) and 20 older (67-91 years) adults performed a choice stepping response time (CSRT) task, a submaximal dorsiflexion force steadiness task, and quiet standing in 3 bilateral stances. All tasks were performed with and without a visuospatial (VS) attention task that involved visualizing a star moving within a 2 × 2 grid. CSRT increased with the addition of the VS task in both groups (p  older adults than young adults (p Older adults were less steady while performing the dorsiflexion task with the VS task (p  adults (p = .235). Performance during quiet standing was not influenced by the VS task in any stance (p  > .084). The findings suggest that visuospatial attention differentially affects postural control in young and older adults and the effect is task-specific. These findings suggest the need to include stepping and force control tasks to further determine what role visuospatial attention plays in postural control. Copyright © 2017. Published by Elsevier Ltd.

  2. 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…

  3. 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…

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

    Directory of Open Access Journals (Sweden)

    Lucie Attout

    Full Text Available 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.

  5. 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

  6. Constant Light Desynchronizes Olfactory versus Object and Visuospatial Recognition Memory Performance.

    Science.gov (United States)

    Tam, Shu K E; Hasan, Sibah; Choi, Harry M C; Brown, Laurence A; Jagannath, Aarti; Hughes, Steven; Hankins, Mark W; Foster, Russell G; Vyazovskiy, Vladyslav V; Bannerman, David M; Peirson, Stuart N

    2017-03-29

    Circadian rhythms optimize physiology and behavior to the varying demands of the 24 h day. The master circadian clock is located in the suprachiasmatic nuclei (SCN) of the hypothalamus and it regulates circadian oscillators in tissues throughout the body to prevent internal desynchrony. Here, we demonstrate for the first time that, under standard 12 h:12 h light/dark (LD) cycles, object, visuospatial, and olfactory recognition performance in C57BL/6J mice is consistently better at midday relative to midnight. However, under repeated exposure to constant light (rLL), recognition performance becomes desynchronized, with object and visuospatial performance better at subjective midday and olfactory performance better at subjective midnight. This desynchrony in behavioral performance is mirrored by changes in expression of the canonical clock genes Period1 and Period2 (Per1 and Per2), as well as the immediate-early gene Fos in the SCN, dorsal hippocampus, and olfactory bulb. Under rLL, rhythmic Per1 and Fos expression is attenuated in the SCN. In contrast, hippocampal gene expression remains rhythmic, mirroring object and visuospatial performance. Strikingly, Per1 and Fos expression in the olfactory bulb is reversed, mirroring the inverted olfactory performance. Temporal desynchrony among these regions does not result in arrhythmicity because core body temperature and exploratory activity rhythms persist under rLL. Our data provide the first demonstration that abnormal lighting conditions can give rise to temporal desynchrony between autonomous circadian oscillators in different regions, with different consequences for performance across different sensory domains. Such a dispersed network of dissociable circadian oscillators may provide greater flexibility when faced with conflicting environmental signals.SIGNIFICANCE STATEMENT A master circadian clock in the suprachiasmatic nuclei (SCN) of the hypothalamus regulates physiology and behavior across the 24 h day by

  7. Those are Your Legs: The Effect of Visuo-Spatial Viewpoint on Visuo-Tactile Integration and Body Ownership.

    Science.gov (United States)

    Pozeg, Polona; Galli, Giulia; Blanke, Olaf

    2015-01-01

    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 crossmodal 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.

  8. 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.

  9. Visuospatial planning in the travelling salesperson problem: a connectionist account of normal and impaired performance.

    Science.gov (United States)

    Cutini, Simone; Di Ferdinando, Andrea; Basso, Demis; Silvia Bisiacchi, Patrizia; Zorzi, Marco

    2008-03-01

    Planning is a fundamental cognitive function frequently employed in common daily activities. The Travelling Salesperson Problem (TSP), in which participants decide what order between a number of locations optimizes total travel distance, is a paradigm that allows the study of planning and strategy choice. In the TSP, subjects adopt visuo-spatial heuristics to perform the task and operate a continuous monitoring to adapt their behaviour. We present a connectionist model of the TSP that simulates bottom-up and top-down influences observed in the execution of the task. The model accounts for the continuous monitoring observed in healthy participants, and, after a simulated lesion, it also accounts for the decrease of heuristic switching observed in frontal patients and in normal subjects under repetitive transcranial magnetic stimulation (rTMS) over frontal lobe.

  10. The Fargo Map Test: a standardized method for assessing remote memory for visuospatial information.

    Science.gov (United States)

    Beatty, W W

    1988-01-01

    At present, there is no standardized method for assessing remote memory (RM) for visuospatial information in humans. The Fargo Map Test (FMT) uses knowledge of the locations of geographical features in regions of the country in which subjects currently live and formerly resided to provide a measure of this aspect of RM. Two different formats of the FMT have been developed, which differ in their demands for fine motor skill, ease of scoring, and in the amount and nature of geographical knowledge that can be measured. Preliminary findings suggest that both formats are equally sensitive to the influences of gender and age in normal subjects. Furthermore, knowledge of the geography of regions of prior residence appears to be stable over a period of at least 15 years.

  11. The impact of visuo-spatial number forms on simple arithmetic.

    Science.gov (United States)

    Ward, Jamie; Sagiv, Noam; Butterworth, Brian

    2009-01-01

    Number forms, conscious visuo-spatial representations of the sequence of numbers, are found in around 12% of the population. However, their contribution to numerical cognition is not well understood. In this study we contrast the speeded performance of individuals with number forms versus controls on single digit multiplication, subtraction and addition. Previous research has suggested that multiplication may rely more on retrieval of verbal facts whereas subtraction relies more on online calculation using a putatively spatial 'mental number line'. If people with number forms rely more heavily on visual-spatial strategies than verbal ones then we hypothesised that multiplication may be disproportionately affected by this strategy relative to subtraction, and this was found.

  12. 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...... that visuo-spatial working memory can simply be dissociated into visual and spatial sub-components....

  13. 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.

  14. Real-time decoding of brain responses to visuospatial attention using 7T fMRI.

    Directory of Open Access Journals (Sweden)

    Patrik Andersson

    Full Text Available Brain-Computer interface technologies mean to create new communication channels between our mind and our environment, independent of the motor system, by detecting and classifying self regulation of local brain activity. BCIs can provide patients with severe paralysis a means to communicate and to live more independent lives. There has been a growing interest in using invasive recordings for BCI to improve the signal quality. This also potentially gives access to new control strategies previously inaccessible by non-invasive methods. However, before surgery, the best implantation site needs to be determined. The blood-oxygen-level dependent signal changes measured with fMRI have been shown to agree well spatially with those found with invasive electrodes, and are the best option for pre-surgical localization. We show, using real-time fMRI at 7T, that eye movement-independent visuospatial attention can be used as a reliable control strategy for BCIs. At this field strength even subtle signal changes can be detected in single trials thanks to the high contrast-to-noise ratio. A group of healthy subjects were instructed to move their attention between three (two peripheral and one central spatial target regions while keeping their gaze fixated at the center. The activated regions were first located and thereafter the subjects were given real-time feedback based on the activity in these regions. All subjects managed to regulate local brain areas without training, which suggests that visuospatial attention is a promising new target for intracranial BCI. ECoG data recorded from one epilepsy patient showed that local changes in gamma-power can be used to separate the three classes.

  15. Executive and visuospatial deficits in patients with chronic progressive external ophthalmoplegia and Kearns-Sayre syndrome.

    Science.gov (United States)

    Bosbach, Simone; Kornblum, Cornelia; Schröder, Rolf; Wagner, Michael

    2003-05-01

    Although neuropsychological deficits have been reported in mitochondrial cytopathies, patients with chronic progressive external ophthalmoplegia (CPEO) or Kearns-Sayre syndrome (KSS) have not been studied systematically using a comprehensive test battery. The aim of our study was to assess the range and extent of putative cognitive dysfunction in 22 patients with CPEO or KSS, and to compare cognitive performance of patients with healthy control subjects matched for age, sex and years of education. Genetic analysis of skeletal muscle tissue from 22 patients with CPEO or KSS included screening for mitochondrial DNA (mtDNA) point mutations (3243/8344) and mtDNA deletions. All patients were examined by a neuropsychological test battery covering verbal skills, verbal and visual memory, visuo-spatial perception, visual construction, attention, abstraction and flexibility, and Quality of Life. Molecular genetic analysis of mtDNA revealed single large-scale deletions in 15 out of 22 patients and the tRNA (Leu) A3243G point mutation in two out of 22 patients. In five out of 22 patients none of the frequently encountered mtDNA mutations could be detected. Neuropsychological testing did not reveal general intellectual deterioration, but specific cognitive deficits, particularly in visual construction, attention and abstraction/flexibility. Subgroup analysis of 15 patients with mtDNA deletions showed similar results when compared with the full group. In our series of patients with CPEO or KSS neuropsychological testing did not reveal signs that would suggest general intellectual decline or dementia, but provided evidence of specific focal neuropsychological deficits, suggesting particular impairment of visuospatial perception associated to parieto-occipital lobes and executive deficits associated to the prefrontal cortex.

  16. 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 be

  17. 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.

  18. Effects of gender and executive function on visuospatial working memory in adult obsessive-compulsive disorder.

    Science.gov (United States)

    Martoni, Riccardo Maria; Salgari, Giulia; Galimberti, Elisa; Cavallini, Maria Cristina; O'Neill, Joseph

    2015-12-01

    Visuospatial working memory (VSWM) is the ability of the brain to transiently store and manipulate visual information. VSWM deficiencies have been reported in obsessive-compulsive disorder (OCD), but not consistently, perhaps due to variability in task design and clinical patient factors. To explore this variability, this study assessed effects of the design factors task difficulty and executive organizational strategy and of the clinical factors gender, OCD symptom dimension, and duration of illness on VSWM in OCD. The CANTAB spatial working memory, spatial recognition memory, delayed matching to sample, and stop signal tasks were administered to 42 adult OCD patients and 42 age- and sex-matched healthy controls. Aims were to detect a possible VSWM deficit in the OCD sample, to evaluate influences of the above task and patient factors, to determine the specificity of the deficit to the visuospatial subdomain, and to examine effects of sustained attention as potential neurocognitive confound. We confirmed previous findings of a VSWM deficit in OCD that was more severe for greater memory load (task difficulty) and that was affected by task strategy (executive function). We failed to demonstrate significant deficits in neighboring or confounding neurocognitive subdomains (visual object recognition or visual object short-term memory, sustained attention). Notably, the VSWM deficit was only significant for female patients, adding to evidence for sexual dimorphism in OCD. Again as in prior work, more severe OCD symptoms in the symmetry dimension (but no other dimension) significantly negatively impacted VSWM. Duration of illness had no significant effect on VSWM. VSWM deficits in OCD appear more severe with higher task load and may be mediated through poor task strategy. Such deficits may present mainly in female patients and in (male and female) patients with symmetry symptoms.

  19. The contribution of the human PPC to the orienting of visuospatial attention during smooth pursuit.

    Science.gov (United States)

    Drew, Anthony S; van Donkelaar, Paul

    2007-05-01

    Smooth pursuit eye movements function to stabilize the retinal image of small moving targets. In order for those targets to be foveated, however, they must first be "captured" by an attentional mechanism which then interacts with the oculomotor system. Cortical sites involved with producing smooth pursuit overlap with areas known to be involved in directing visuospatial attention, particularly the posterior parietal cortex (PPC). The goal of the current study was to characterize the contributions made by the left and right posterior parietal cortices (lPPC and rPPC) to the interaction between visuospatial attention and the generation of smooth pursuit eye movements. Transcranial magnetic stimulation (TMS) was used to temporarily disrupt each area at different times around target motion onset in a pursuit task that explicitly manipulated the covert orienting of attention. TMS over the lPPC, rPPC and a control site (the vertex) evoked a similar pattern of results, in that the earlier TMS delivery times caused a reduced pursuit latency compared to baseline measures, while TMS immediately prior to target motion onset resulted in latencies slower than baseline. In addition, however, TMS over the lPPC and rPPC (but not the vertex) preferentially influenced the generation of contralateral pursuit, with the lPPC doing so in a relatively time-independent manner, and the rPPC doing so in a time-dependent manner. This pattern of results implies that both the left and right PPC are directly involved in the interaction between attention and smooth pursuit preparation.

  20. The precuneus and visuospatial attention in near and far space: a transcranial magnetic stimulation study.

    Science.gov (United States)

    Mahayana, Indra T; Tcheang, Lili; Chen, Chiao-Yun; Juan, Chi-Hung; Muggleton, Neil G

    2014-01-01

    There is a large body of evidence for the involvement of the parietal cortex in orientation and navigation in space. This has been supplemented by investigation of the contribution of a number of subregions using transcranial magnetic stimulation. The role of the precuneus area, located in the medial plane of posterior parietal cortex (PPC), in visuospatial functions is not well understood. We investigated the contribution of this area using the landmark task. Participants were asked to make forced-choice judgments of which side of prebisected line was longer for near and far viewing conditions (70 and 180 cm, respectively). Online 10 Hz, repetitive transcranial magnetic stimulation (rTMS) was delivered for 500 ms over the right precuneus, rPPC and vertex (control), in separate blocks of trials. The rPPC stimulation was used as a positive control, having previously resulted in "neglect like" spatial bias effects in a number of studies. A no-TMS condition showed a leftward spatial bias (pseudoneglect) for near space judgments but not for far space and was used as the baseline. Precuneus stimulation resulted in rightward spatial bias from the midpoint in near space similar to the rPPC neglect-like effect. No significant effects were seen with vertex stimulation. This study shows that precuneus, like other parietal areas, is involved in visuospatial functions. Further work is required to clarify how the contribution of this area differs from other parietal regions. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. 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.

  2. 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.

  3. Effects of sleep reduction on the phonological and visuospatial components of working memory

    Science.gov (United States)

    del Angel, Jacqueline; Cortez, Juventino; Juárez, Diana; Guerrero, Martha; García, Aída; Ramírez, Candelaria; Valdez, Pablo

    2015-01-01

    Sleep reduction impairs the performance of many tasks, so it may affect a basic cognitive process, such as working memory, crucial for the execution of a broad range of activities. Working memory has two storage components: a phonological and a visuospatial component. The objective of this study was to analyze the effects of sleep reduction for 5 days on the storage components of working memory. Thirteen undergraduate students (18.77±2.20 years of age), 5 men and 8 women, responded two N-Back tasks (auditory and visual), with three sections each (0-Back, 1-Back, and 2-Back). These tasks were performed at 13:00 h under the following conditions: before sleep reduction (control; C); on the first (SR1), fourth (SR4), and fifth (SR5) days of sleep reduction (4 h of sleep per night); and one day after they slept freely (recovery, R). Sleep reduction produced a decrement in accuracy on the auditory 2-Back section the fifth day of sleep reduction (C=87.86±13.35%; SR5=74.76±16.37%; F=14.57, p<0.01). In the visual 2-Back section accuracy decreased (C=88.10±9.95%; SR1=82.45±11.57%; SR5=77.76±14.14%; F=10.80, p<0.05), and reaction time increased (C=810.02±173.96 ms; SR1=913.51±172.25 ms; SR5=874.78±172.27 ms; F=10.80, p<0.05) on the first and fifth day of sleep reduction. In conclusion, five days of sleep reduction produces a decrease in the phonological and visuospatial storage components of working memory, which may interfere with processing verbal information and solving problems that require spatial analysis. PMID:26483947

  4. Modulation of resource allocation by intelligent individuals in linguistic, mathematical and visuo-spatial tasks.

    Science.gov (United States)

    Lee, Giyoung; Ojha, Amitash; Kang, Jun-Su; Lee, Minho

    2015-07-01

    This study investigates two questions: first, how individuals with high-intelligence allocate cognitive resources while solving linguistic, mathematical and visuo-spatial tasks with varying degree of difficulty as compared to individuals with low intelligence? Second, how to distinguish between high and low intelligent individuals by analyzing pupil dilation and eye blink together? We measured the response time, error rates along with pupil dilation and eye blink rate that indicate resource allocation. We divided the whole processing into three stages namely: pre-stimuli (5s prior to stimuli onset), during stimuli and post stimuli (until 5s after the response) for better assessment of preparation and resource allocation strategies. Individuals with high intelligence showed greater task evoked pupil dilation, decreased eye blink with less response time and error rates during-stimuli stage (processing) of tough linguistic and visuo-spatial tasks but not during mathematical tasks. The finding suggests that individuals with high intelligence allocate more resources if the task demands are high else they allocate less resources. Greater pre-stimuli pupil dilation and increased eye blink of high intelligent individuals in all tasks indicated their attentiveness and preparedness. The result of our study shows that individuals with high intelligence are more attentive and flexible in terms of altering the resource allocation strategy according to task demand. Eye-blinks along with pupil dilation and other behavioral parameters can be reliably used to assess the intelligence of an individual and the analysis of pupil dilation and blink rate at pre-stimuli stage can be crucial in distinguishing individuals with varying intelligence. Copyright © 2015. Published by Elsevier B.V.

  5. Opportunity's Surroundings After Sol 1820 Drive (Polar)

    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). This view is presented as a polar projection with geometric seam correction. North is at the top. 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.

  6. Opportunity's Surroundings on Sol 1798 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a vertical projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. 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 lighter-toned bedrock.

  7. Opportunity's Surroundings on Sol 1798 (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a polar projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. 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 lighter-toned bedrock.

  8. 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.

  9. Computerized Dual-Task Testing of Gait and Visuospatial Cognitive Functions; Test-Retest Reliability and Validity.

    Science.gov (United States)

    Szturm, Tony J; Sakhalkar, Vedant S; Kanitkar, Anuprita; Nankar, Mayur

    2017-01-01

    The common occurrence of age decline in mobility and cognition does cause a decrease in the level of physical activity and an increased falls risk. Consequently, dual -task (DT) assessment that simultaneously addresses both mobility skills and cognitive functions are important because, continued difficulties and fall injuries will have a sizable impact in this population. The first objective of the present study was to assess test-retest reliability of a computerized DT treadmill walking protocol and concurrent outcome measures of gait and visuospatial executive function in a group of healthy older adults. Secondly, discriminative validity was evaluated by examining the effect of DT conditions (single task vs. dual-task) on; (a) spatiotemporal gait measures (average and coefficient of variation) and (b) visuomotor and visuospatial executive performance measures. Twenty-five community-dwelling individuals median age 65 (range 61-67) were recruited from a Fitness Facility. Participants performed a computerized visuomotor tracking task and a visuospatial executive game task in standing and while treadmill walking. Testing was conducted on two occasions, 1 week apart. Moderate to high test-retest reliability (ICC values of 0.65-0.88) were observed for spatiotemporal gait variables. No significant differences between the group means were observed between test periods in any gait variable. Moderate test-retest reliability (ICC values of 0.6-0.65) was observed for measures of visuomotor and visuospatial executive performance during treadmill walking. Significant DT effects were observed for both spatiotemporal gait variables and visuospatial executive performance measures. This study demonstrates the reliability and reproducibility of the computer-based assessment tool for dual task treadmill walking. The high to moderate ICC values and the lack of systematic errors in the measures indicate that this tool has the ability to repeatedly record reliable data from community

  10. Opportunity's Surroundings on Sol 1798 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11850 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11850 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. 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 lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  11. 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...

  12. Opportunity's Surroundings After Sol 1820 Drive (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11841 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11841 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). This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. 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-perspective projection with geometric seam correction.

  13. Opportunity's Surroundings on Sol 1818 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11846 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11846 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 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  14. Similar prefrontal cortical activities between general fluid intelligence and visuospatial working memory tasks in preschool children as revealed by optical topography.

    Science.gov (United States)

    Kuwajima, Mariko; Sawaguchi, Toshiyuki

    2010-10-01

    General fluid intelligence (gF) is a major component of intellect in both adults and children. Whereas its neural substrates have been studied relatively thoroughly in adults, those are poorly understood in children, particularly preschoolers. Here, we hypothesized that gF and visuospatial working memory share a common neural system within the lateral prefrontal cortex (LPFC) during the preschool years (4-6 years). At the behavioral level, we found that gF positively and significantly correlated with abilities (especially accuracy) in visuospatial working memory. Optical topography revealed that the LPFC of preschoolers was activated and deactivated during the visuospatial working memory task and the gF task. We found that the spatio-temporal features of neural activity in the LPFC were similar for both the visuospatial working memory task and the gF task. Further, 2 months of training for the visuospatial working memory task significantly increased gF in the preschoolers. These findings suggest that a common neural system in the LPFC is recruited to improve the visuospatial working memory and gF in preschoolers. Efficient recruitment of this neural system may be important for good performance in these functions in preschoolers, and behavioral training using this system would help to increase gF at these ages.

  15. Effects of sleep reduction on the phonological and visuospatial components of working memory

    Directory of Open Access Journals (Sweden)

    Jacqueline del Angel

    2015-04-01

    Full Text Available Sleep reduction impairs the performance of many tasks, so it may affect a basic cognitive process, such as working memory, crucial for the execution of a broad range of activities. Working memory has two storage components: a phonological and a visuospatial component. The objective of this study was to analyze the effects of sleep reduction for 5 days on the storage components of working memory. Thirteen undergraduate students (18.77±2.20 years of age, 5 men and 8 women, responded two N-Back tasks (auditory and visual, with three sections each (0-Back, 1-Back, and 2-Back. These tasks were performed at 13:00 h under the following conditions: before sleep reduction (control; C; on the first (SR1, fourth (SR4, and fifth (SR5 days of sleep reduction (4 h of sleep per night; and one day after they slept freely (recovery, R. Sleep reduction produced a decrement in accuracy on the auditory 2-Back section the fifth day of sleep reduction (C=87.86±13.35%; SR5=74.76±16.37%; F=14.57, p<0.01. In the visual 2-Back section accuracy decreased (C=88.10±9.95%; SR1=82.45±11.57%; SR5=77.76±14.14%; F=10.80, p<0.05, and reaction time increased (C=810.02±173.96 ms; SR1=913.51±172.25 ms; SR5=874.78±172.27 ms; F=10.80, p<0.05 on the first and fifth day of sleep reduction. In conclusion, five days of sleep reduction produces a decrease in the phonological and visuospatial storage components of working memory, which may interfere with processing verbal information and solving problems that require spatial analysis.

  16. 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. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Individual differences in reasoning and visuospatial attention are associated with prefrontal and parietal white matter tracts in healthy older adults.

    Science.gov (United States)

    Monge, Zachary A; Greenwood, Pamela M; Parasuraman, Raja; Strenziok, Maren

    2016-07-01

    Although reasoning and attention are 2 cognitive processes necessary for ensuring the efficiency of many everyday activities in older adults, the role of white matter integrity in these processes has been little studied. This is an important question due to the role of white matter integrity as a neural substrate of cognitive aging. Here, we sought to examine the white matter tracts subserving reasoning and visuospatial attention in healthy older adults. Sixty-one adults ages 60 and older completed a battery of cognitive tests to assess reasoning and visuospatial attention. In addition, diffusion tensor images were collected to assess fractional anisotropy (FA), a measure of white matter integrity. A principle components analysis of the test scores yielded 2 components: reasoning and visuospatial attention. Whole-brain correlations between FA and the cognitive components were submitted to probabilistic tractography analyses for visualization of cortical targets of tracts. For reasoning, bilateral thalamo-anterior prefrontal, anterior corpus callosum, and corpus callosum body tracts interconnecting the superior frontal cortices and right cingulum bundle were found. For visuospatial attention, a right inferior fronto-parietal tract and bilateral parietal and temporal connections were found. We conclude that in older adults, prefrontal cortex white matter tracts and interhemispheric communication are important in higher order cognitive functioning. On the other hand, right-sided fronto-parietal tracts appear to be critical for supporting control of cognitive processes, such as redirecting attention. Researchers may use our results to develop neuroscience-based interventions for older adults targeting brain mechanisms involved in cognitive plasticity. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  18. Noncredible cognitive performance at clinical evaluation of adult ADHD: An embedded validity indicator in a visuospatial working memory test.

    Science.gov (United States)

    Fuermaier, Anselm B M; Tucha, Oliver; Koerts, Janneke; Lange, Klaus W; Weisbrod, Matthias; Aschenbrenner, Steffen; Tucha, Lara

    2017-12-01

    The assessment of performance validity is an essential part of the neuropsychological evaluation of adults with attention-deficit/hyperactivity disorder (ADHD). Most available tools, however, are inaccurate regarding the identification of noncredible performance. This study describes the development of a visuospatial working memory test, including a validity indicator for noncredible cognitive performance of adults with ADHD. Visuospatial working memory of adults with ADHD (n = 48) was first compared to the test performance of healthy individuals (n = 48). Furthermore, a simulation design was performed including 252 individuals who were randomly assigned to either a control group (n = 48) or to 1 of 3 simulation groups who were requested to feign ADHD (n = 204). Additional samples of 27 adults with ADHD and 69 instructed simulators were included to cross-validate findings from the first samples. Adults with ADHD showed impaired visuospatial working memory performance of medium size as compared to healthy individuals. Simulation groups committed significantly more errors and had shorter response times as compared to patients with ADHD. Moreover, binary logistic regression analysis was carried out to derive a validity index that optimally differentiates between true and feigned ADHD. ROC analysis demonstrated high classification rates of the validity index, as shown in excellent specificity (95.8%) and adequate sensitivity (60.3%). The visuospatial working memory test as presented in this study therefore appears sensitive in indicating cognitive impairment of adults with ADHD. Furthermore, the embedded validity index revealed promising results concerning the detection of noncredible cognitive performance of adults with ADHD. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  19. Persistence of Gender Related-Effects on Visuo-Spatial and Verbal Working Memory in Right Brain-Damaged Patients.

    Science.gov (United States)

    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) administering the Corsi Test (CBT) and the Digit Span (DS) using two different versions: forward (fCBT and fDS), subjects were required to repeat stimuli in the same order that they were presented; and backward (bCBT and bDS), subjects were required to repeat stimuli in the opposite order of presentation. In this way, passive storage and active processing of working memory were assessed. Our results showed the persistence of gender-related effects in spite of the presence of right brain lesions. We found that men outperformed women both in CBT and DS, regardless of active and passive processing of verbal and visuo-spatial stimuli. The presence of visuo-spatial disorders (i.e., hemineglect) can affect the performance on Corsi Test. In our sample, men and women were equally affected by hemineglect, therefore it did not mask the gender effect. Generally speaking, the persistence of the men's superiority in visuo-spatial tasks may be interpreted as a protective factor, at least for men, within other life factors such as level of education or kind of profession before retirement.

  20. How to enhance route learning and visuo-spatial working memory in aging: a training for residential care home residents.

    Science.gov (United States)

    Mitolo, Micaela; Borella, Erika; Meneghetti, Chiara; Carbone, Elena; Pazzaglia, Francesca

    2017-05-01

    This study aimed to assess the efficacy of a route-learning training in a group of older adults living in a residential care home. We verified the presence of training-specific effects in tasks similar to those trained - route-learning tasks - as well as transfer effects on related cognitive processes - visuo-spatial short-term memory (VSSTM; Corsi Blocks Test (CBT), forward version), visuo-spatial working memory (VSWM; CBT, backward version; Pathway Span Tasks; Jigsaw Puzzle Test) - and in self-report measures. The maintenance of training benefits was examined after 3 months. Thirty 70-90-year-old residential care home residents were randomly assigned to the route-learning training group or to an active control group (involved in non-visuo-spatial activities). The trained group performed better than the control group in the route-learning tasks, retaining this benefit 3 months later. Immediate transfer effects were also seen in visuo-spatial span tasks (i.e., CBT forward and backward version and Pathway Span Task); these benefits had been substantially maintained at the 3-month follow-up. These findings suggest that a training on route learning is a promising approach to sustain older adults' environmental learning and some related abilities (e.g., VSSTM and VSWM), even in residential care home residents.

  1. 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.

  2. 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.

  3. No Effect of Different Stimulation Conditions on Verbal Fluency and Visuospatial Orientation in Patients with Subthalamic Nucleus Deep Brain Stimulation.

    Science.gov (United States)

    Yilmaz, Rezzak; Akbostancı, M Cenk; Mercan, F Nazlı; Sorgun, Mine H; Savaş, Ali

    2015-01-01

    Subthalamic nucleus deep brain stimulation is an effective treatment for the symptomatic treatment of Parkinson's disease. Apart from the obvious motor benefits, some cognitive side effects have been reported, particularly in verbal fluency. Our aim was to evaluate the effects of the stimulation on verbal fluency and visuospatial orientation with changing stimulation conditions in 35 patients with Parkinson's disease. Patients were randomized for their stimulation conditions as 'both on', 'both off', 'right on', and 'left on' and underwent verbal fluency and visuospatial orientation tasks during their drug-on periods. Letter and categorical fluency tasks and Benton's Judgment of Line Orientation Test were used for assessment. Overall, 6 patients were excluded due to dementia or depression. For verbal fluency, the number of words they produced in 1 min was similar in four stimulation conditions (p > 0.05). No significant difference was found between stimulation conditions in the spatial orientation task. We were unable to find any significant changes in verbal fluency and visuospatial orientation task scores with different stimulation conditions. This result suggests that either stimulation has no effect on given domains or the effect is so small that more detailed batteries are required to detect the difference. © 2015 S. Karger AG, Basel.

  4. Distinct neural substrates of visuospatial and verbal-analytic reasoning as assessed by Raven's Advanced Progressive Matrices.

    Science.gov (United States)

    Chen, Zhencai; De Beuckelaer, Alain; Wang, Xu; Liu, Jia

    2017-11-24

    Recent studies revealed spontaneous neural activity to be associated with fluid intelligence (gF) which is commonly assessed by Raven's Advanced Progressive Matrices, and embeds two types of reasoning: visuospatial and verbal-analytic reasoning. With resting-state fMRI data, using global brain connectivity (GBC) analysis which averages functional connectivity of a voxel in relation to all other voxels in the brain, distinct neural correlates of these two reasoning types were found. For visuospatial reasoning, negative correlations were observed in both the primary visual cortex (PVC) and the precuneus, and positive correlations were observed in the temporal lobe. For verbal-analytic reasoning, negative correlations were observed in the right inferior frontal gyrus (rIFG), dorsal anterior cingulate cortex and temporoparietal junction, and positive correlations were observed in the angular gyrus. Furthermore, an interaction between GBC value and type of reasoning was found in the PVC, rIFG and the temporal lobe. These findings suggest that visuospatial reasoning benefits more from elaborate perception to stimulus features, whereas verbal-analytic reasoning benefits more from feature integration and hypothesis testing. In sum, the present study offers, for different types of reasoning in gF, first empirical evidence of separate neural substrates in the resting brain.

  5. Visuospatial and Attentional Abilities Predict Driving Simulator Performance Among Older HIV-infected Adults.

    Science.gov (United States)

    Foley, J M; Gooding, A L; Thames, A D; Ettenhofer, M L; Kim, M S; Castellon, S A; Marcotte, T D; Sadek, J R; Heaton, R K; van Gorp, W G; Hinkin, C H

    2013-03-01

    To examine the effects of aging and neuropsychological (NP) impairment on driving simulator performance within a human immunodeficiency virus (HIV)-infected cohort. Participants included 79 HIV-infected adults (n = 58 > age 50, n = 21 ≤ 40) who completed a NP battery and a personnel computer-based driving simulator task. Outcome variables included total completion time (time) and number of city blocks to complete the task (blocks). Compared to the younger group, the older group was less efficient in their route finding (blocks over optimum: 25.9 [20.1] vs 14.4 [16.9]; P = .02) and took longer to complete the task (time: 1297.6 [577.6] vs 804.4 [458.5] seconds; P = .001). Regression models within the older adult group indicated that visuospatial abilities (blocks: b = -0.40, P simulator performance. The NP-impaired group performed more poorly on both time and blocks, compared to the NP normal group. Older HIV-infected adults may be at risk of driving-related functional compromise secondary to HIV-associated neurocognitive decline.

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

    Science.gov (United States)

    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

    2015-08-30

    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 VSWM-related brain abnormalities in ADHD. Functional magnetic resonance imaging (fMRI) data were collected from 109 individuals with ADHD (60% male) and 103 controls (53% male), aged 8-25 years, during a spatial span working memory task. VSWM-related brain activation was found in a widespread network, which was more widespread compared with N-back tasks used in the previous literature. Higher brain activation was associated with higher age and male gender. In comparison with controls, individuals with ADHD showed greater activation in the left inferior frontal gyrus (IFG) and the lateral frontal pole during memory load increase, effects explained by reduced activation on the low memory load in the IFG pars triangularis and increased activation during high load in the IFG pars opercularis. Age and gender effects did not differ between controls and individuals with ADHD. Results indicate that individuals with ADHD have difficulty in efficiently and sufficiently recruiting left inferior frontal brain regions with increasing task difficulty. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Visuo-spatial neglect: a systematic review of current interventions and their effectiveness.

    Science.gov (United States)

    Luauté, Jacques; Halligan, Peter; Rode, Gilles; Rossetti, Yves; Boisson, Dominique

    2006-01-01

    Left visuo-spatial neglect is a well-recognized predictor of poor functional outcome following right hemisphere stroke. Over the past 60 years, 18 different methods have been described and evaluated aimed at reducing the effects of this impairment. Although there are some grounds for optimism particularly in terms of short-term impairment-based effects, the range and degree of disability borne by many patients remain high and the clinical effectiveness of the different methods viewed in terms of long-lasting functional improvement (i.e. improvement of disabilities or handicap) is not clear. A systematic review of the available clinically relevant literature, using comparative and stringent levels of evidence, indicates that visual scanning training (VST), trunk rotation (TR) or repeated neck muscle vibrations (NMV) when associated with an extensive training program, mental imagery training, video feedback training and prism adaptation (PA) can be recommended for the rehabilitation of patients with left neglect. More studies however are needed to determine the optimal paradigm of limb activation (LA) eliciting a sustained functional improvement. Sensory stimulations alone and Fresnel prisms do not appear to be functionally relevant. For the other methods, the actual literature is not sufficient to conclude whether or not a long-term functional improvement can be achieved.

  8. 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.

  9. Binge-eating disorder may be distinguished by visuospatial memory deficits.

    Science.gov (United States)

    Eneva, Kalina T; Murray, Susan M; Chen, Eunice Y

    2017-08-01

    Binge eating disorder (BED), characterized by recurrent episodes of loss of control overeating, is highly comorbid with overweight and obesity. Both loss of control eating and higher body mass index have been associated with poor memory. The current study sought to clarify the relationships between BED, weight and memory. Specifically, visual memory was examined, given evidence of impaired visuospatial abilities in overweight individuals and little research on visual memory in BED. Overweight and normal-weight women with BED and matched healthy controls were administered the Rey Complex Figure Test. Planned contrasts revealed that normal-weight healthy controls performed better than all other groups on the immediate and delayed recall portions of the task. Performance on the immediate recall portion was better among normal-weight individuals than overweight individuals, and performance on both the immediate and delayed recall portions was better among individuals without BED than those with BED. No differences between groups were seen on the copy or recognition trials. Visual memory appears to be impaired among overweight participants and both normal and overweight participants with BED. This finding was specific to retrieval. Replication of this finding in BED using different measures of memory is needed. Copyright © 2017. Published by Elsevier Ltd.

  10. The association of visuospatial working memory with dysthymic disorder in pre-pubertal children.

    Science.gov (United States)

    Franklin, T; Lee, A; Hall, N; Hetrick, S; Ong, J; Haslam, N; Karsz, F; Vance, A

    2010-02-01

    Visuospatial working memory (VSWM) deficits have not been investigated specifically in children with dysthymic disorder (DD), although they are associated with impairments in attention that commonly occur in DD. This study investigates VSWM impairment in children with DD. A cross-sectional study of VSWM in 6- to 12-year-old children with medication-naive DD (n=26) compared to an age-, gender- and 'performance IQ' (PIQ)-matched healthy control group (n=28) was completed. The DD group demonstrated impairment in VSWM, including impairment in the spatial span and strategy components of VSWM. Furthermore, the VSWM impairment remained after controlling for spatial span. Inattentive symptoms were significantly associated with the VSWM impairment. This study of children with DD found deficits in performance on VSWM tasks, suggesting that fronto-striatal-parietal neural networks that underlie processes of attention and the executive component of VSWM are dysfunctional in children with DD. These findings further our understanding of DD and suggest more specific interventions that might improve functioning.

  11. The effect of attenuating noradrenergic neurotransmission by clonidine on brain activity measures of visuospatial attention.

    Science.gov (United States)

    Logemann, H N Alexander; Böcker, Koen B E; Deschamps, Peter K H; Kemner, Chantal; Kenemans, J Leon

    2014-01-01

    In the current study, we investigated the role of noradrenaline in directing (bias) and disengagement of visuospatial attention. We assessed the effect of clonidine on event-related brain potential (ERP) reflections of bias and disengagement in a double-blind placebo-controlled crossover design. An initial dose of 200-μg clonidine was replaced by 100 μg because of marked side effects. Twenty-one healthy male participants performed the visual-spatial cueing task while an electroencephalogram (EEG) was recorded. The behavioral output is the validity effect (benefit of cueing in terms of reaction time to targets). ERP indices for bias were the cue-related early directing attention negativity and late directing attention positivity, and the target-elicited P1 and N1 modulations by validity ('validity-effect'). The ERP index for disengagement was the target-elicited 'late positive deflection' modulation by validity. Behavioral analyses were performed on 16 participants, electrophysiological analyses on a subset (n=9). Clonidine attenuated the N1 effect, albeit in a subsample. Neither cue-elicited ERPs nor the behavioral validity effect were affected. Clonidine-induced blood pressure reduction was correlated with the reduction of the late positive deflection effect under clonidine. Clonidine attenuated the result of bias in a subsample and may have a modulating effect on disengagement.

  12. Culture-related differences in default network activity during visuo-spatial judgments.

    Science.gov (United States)

    Goh, Joshua O S; Hebrank, Andrew C; Sutton, Bradley P; Chee, Michael W L; Sim, Sam K Y; Park, Denise C

    2013-02-01

    Studies on culture-related differences in cognition have shown that Westerners attend more to object-related information, whereas East Asians attend more to contextual information. Neural correlates of these different culture-related visual processing styles have been reported in the ventral-visual and fronto-parietal regions. We conducted an fMRI study of East Asians and Westerners on a visuospatial judgment task that involved relative, contextual judgments, which are typically more challenging for Westerners. Participants judged the relative distances between a dot and a line in visual stimuli during task blocks and alternated finger presses during control blocks. Behaviorally, East Asians responded faster than Westerners, reflecting greater ease of the task for East Asians. In response to the greater task difficulty, Westerners showed greater neural engagement compared to East Asians in frontal, parietal, and occipital areas. Moreover, Westerners also showed greater suppression of the default network-a brain network that is suppressed under condition of high cognitive challenge. This study demonstrates for the first time that cultural differences in visual attention during a cognitive task are manifested both by differences in activation in fronto-parietal regions as well as suppression in default regions.

  13. 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.

  14. 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.

  15. 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.

  16. Cognitive mapping deficits in schizophrenia: Evidence from clinical correlates of visuospatial transformations.

    Science.gov (United States)

    Agarwal, Sri Mahavir; Danivas, Vijay; Amaresha, Anekal C; Shivakumar, Venkataram; Kalmady, Sunil V; Bose, Anushree; Narayanaswamy, Janardhanan C; Venkatasubramanian, Ganesan

    2015-08-30

    The 'cognitive mapping' component of spatial cognition, namely - the allocentric/egocentric function and its relation to symptoms in schizophrenia is relatively unexplored. In this study, we compared schizophrenia patients (N=44) to demographically-matched healthy controls (N=43) using computer-administered visuospatial transformation tasks with egocentric and allocentric components and analyzed their correlation with symptoms. Significant diagnosis X task-type interaction effect was seen on task accuracy. Patients performed significantly worse than controls in the allocentric letter rotation task (LRT) but not in the egocentric people rotation task (PRT). Accuracy in the LRT was significantly lesser than in PRT among patients but not among controls. Patients were significantly slower as compared to controls in both tasks. Both groups took longer to perform PRT as compared to LRT. LRT accuracy showed significant negative correlation with total positive symptoms as well as negative symptoms scores. Angle of rotation, perspective (front-facing/back-facing), orientation (mirrored/normal), and stimulus type (letter/number) were found to significantly influence performance in both groups of subjects. The present data support the finding that there is a differential impairment of allocentric abilities in schizophrenia patients. Further systematic research in this area may facilitate better understanding of schizophrenia pathogenesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Robust Sex Differences in Jigsaw Puzzle Solving—Are Boys Really Better in Most Visuospatial Tasks?

    Directory of Open Access Journals (Sweden)

    Vid Kocijan

    2017-10-01

    Full Text Available Sex differences are consistently reported in different visuospatial tasks with men usually performing better in mental rotation tests while women are better on tests for memory of object locations. In the present study, we investigated sex differences in solving jigsaw puzzles in children. In total 22 boys and 24 girls were tested using custom build tablet application representing a jigsaw puzzle consisting of 25 pieces and featuring three different pictures. Girls outperformed boys in solving jigsaw puzzles regardless of the picture. Girls were faster than boys in solving the puzzle, made less incorrect moves with the pieces of the puzzle, and spent less time moving the pieces around the tablet. It appears that the strategy of solving the jigsaw puzzle was the main factor affecting differences in success, as girls tend to solve the puzzle more systematically while boys performed more trial and error attempts, thus having more incorrect moves with the puzzle pieces. Results of this study suggest a very robust sex difference in solving the jigsaw puzzle with girls outperforming boys by a large margin.

  18. Mapping of the Underlying Neural Mechanisms of Maintenance and Manipulation in Visuo-Spatial Working Memory Using An n-back Mental Rotation Task: A Functional Magnetic Resonance Imaging Study

    OpenAIRE

    Lamp, Gemma; Alexander, Bonnie; Laycock, Robin; Crewther, David P.; Crewther, Sheila G.

    2016-01-01

    Mapping of the underlying neural mechanisms of visuo-spatial working memory (WM) has been shown to consistently elicit activity in right hemisphere dominant fronto-parietal networks. However to date, the bulk of neuroimaging literature has focused largely on the maintenance aspect of visuo-spatial WM, with a scarcity of research into the aspects of WM involving manipulation of information. Thus, this study aimed to compare maintenance-only with maintenance and manipulation of visuo-spatial st...

  19. Enhanced sources of acoustic power surrounding AR11429

    OpenAIRE

    Donea, Alina; Hanson, Christopher

    2013-01-01

    Multi-frequency power maps of the local acoustic oscillations show acoustic enhancements (\\acoustic-power halos") at high frequencies surrounding large active region. Computational seismic holography reveals a high-frequency \\acoustic-emission halo", or \\seismic glory" surrounding large active regions. In this study, we have applied computational seismic holography to map the seismic seismic source density surrounding AR 11429. Studies of HMI/SDO Doppler data, shows that the "acoustic halos" ...

  20. Cannabidiol attenuates deficits of visuospatial associative memory induced by Δ9tetrahydrocannabinol

    Science.gov (United States)

    Wright, M Jerry; Vandewater, Sophia A; Taffe, Michael A

    2013-01-01

    BACKGROUND AND PURPOSE Recent human studies suggest that recreational cannabis strains that are relatively high in cannabidiol (CBD) content produce less cognitive impairment than do strains with negligible CBD and similar Δ9tetrahydrocannabinol (THC) content. Self-selection in such studies means it is impossible to rule out additional variables which may determine both cannabis strain selection and basal cognitive performance level. Controlled laboratory studies can better determine a direct relationship. EXPERIMENTAL APPROACH In this study, adult male rhesus monkeys were assessed on visuospatial Paired Associates Learning and Self-Ordered Spatial Search memory tasks, as well as additional tests of motivation and manual dexterity. Subjects were challenged with THC (0.2, 0.5 mg·kg−1, i.m.) in randomized order and evaluated in the presence or absence of 0.5 mg·kg−1 CBD. KEY RESULTS CBD attenuated the effects of THC on paired associates learning and a bimanual motor task without affecting the detrimental effects of THC on a Self-Ordered Spatial Search task of working memory. CBD did not significantly reverse THC-induced impairment of a progressive ratio or a rotating turntable task. CONCLUSIONS AND IMPLICATIONS This study provides direct evidence that CBD can oppose the cognitive-impairing effects of THC and that it does so in a task-selective manner when administered simultaneously in a 1:1 ratio with THC. The addition of CBD to THC-containing therapeutic products may therefore help to ameliorate unwanted cognitive side-effects. LINKED ARTICLE This article is commented on by Mechoulam and Parker, pp 1363–1364 of this issue. To view this commentary visit http://dx.doi.org/10.1111/bph.12400 PMID:23550724

  1. Cannabidiol attenuates deficits of visuospatial associative memory induced by Δ(9) tetrahydrocannabinol.

    Science.gov (United States)

    Wright, M Jerry; Vandewater, Sophia A; Taffe, Michael A

    2013-12-01

    Recent human studies suggest that recreational cannabis strains that are relatively high in cannabidiol (CBD) content produce less cognitive impairment than do strains with negligible CBD and similar Δ(9) tetrahydrocannabinol (THC) content. Self-selection in such studies means it is impossible to rule out additional variables which may determine both cannabis strain selection and basal cognitive performance level. Controlled laboratory studies can better determine a direct relationship. In this study, adult male rhesus monkeys were assessed on visuospatial Paired Associates Learning and Self-Ordered Spatial Search memory tasks, as well as additional tests of motivation and manual dexterity. Subjects were challenged with THC (0.2, 0.5 mg·kg(-1) , i.m.) in randomized order and evaluated in the presence or absence of 0.5 mg·kg(-1) CBD. CBD attenuated the effects of THC on paired associates learning and a bimanual motor task without affecting the detrimental effects of THC on a Self-Ordered Spatial Search task of working memory. CBD did not significantly reverse THC-induced impairment of a progressive ratio or a rotating turntable task. This study provides direct evidence that CBD can oppose the cognitive-impairing effects of THC and that it does so in a task-selective manner when administered simultaneously in a 1:1 ratio with THC. The addition of CBD to THC-containing therapeutic products may therefore help to ameliorate unwanted cognitive side-effects. This article is commented on by Mechoulam and Parker, pp 1363-1364 of this issue. To view this commentary visit http://dx.doi.org/10.1111/bph.12400. © 2013 The Authors. British Journal of Pharmacology © 2013 The British Pharmacological Society.

  2. 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.

  3. Isolating event-related potential components associated with voluntary control of visuo-spatial attention.

    Science.gov (United States)

    McDonald, John J; Green, Jessica J

    2008-08-28

    Attention-directing cues presented at fixation evoke several lateralized event-related potential (ERP) components prior to the onset of visual targets. These components have been associated with the control of visuo-spatial attention, but the neuro-cognitive operations and neural generators of the components are still largely unknown. Here, we isolated cue-elicited ERP activity in different ways to home in on different neuro-cognitive operations and to gain a better understanding about the possible neuroanatomical sources of the cue-elicited ERP activities. To isolate lateralized cue-ERP activity, we compared shift-left and shift-right cue ERPs to shift-up cue ERPs. To measure all of the ERP activity related to attentional control, including spatially nonspecific activity that is removed in the process of isolating lateralized cue-ERP components, we compared shift-cue ERPs to neutral-cue (i.e., no-shift) ERPs. Isolated lateralized-ERP activity was seen in the contralateral-occipital lobe in the early phase of the cue-target interval and in the ipsilateral-occipital lobe in the late phase. The later, ipsilateral activity indicates that the late directing attention positivity (LDAP) reflected processing of the to-be-ignored location. The neutral-cue isolation revealed a shift-related positivity over posterior scalp regions and a shift-related negativity over more anterior scalp regions. The spatio-temporal sequence of shift-related activity observed on the scalp, together with estimates of distributed source activity underlying the shift-related ERP components, indicated that frontal and parietal regions of cortex participated in the control of attention and led to pre-target biasing in visual cortical areas.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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. Copyright

  9. 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

  10. Teacher Leadership: Everyday Practices Surrounding Work- Related Stress

    National Research Council Canada - National Science Library

    Chiweshe Nigel

    2015-01-01

    This interpretivist study contributes to our scholarly understanding of how everyday practices surrounding work-related stress in education affect teacher leadership and successful learning outcomes...

  11. Complex regional pain syndrome (CRPS) impairs visuospatial perception,whereas post-herpetic neuralgia does not: possible implications for supraspinal mechanism of CRPS.

    Science.gov (United States)

    Uematsu, Hironobu; Sumitani, Masahiko; Yozu, Arito; Otake, Yuko; Shibata, Masahiko; Mashimo, Takashi; Miyauchi, Satoru

    2009-11-01

    Complex regional pain syndrome (CRPS) patients show impaired visuospatial perception in the dark, as compared to normal patients with acute nociceptive pain. The purpose of this study is 2-fold: (i) to ascertain whether this distorted visuospatial perception is related to the chronicity of pain, and (ii) to analyse visuospatial perception of CRPS in comparison with another neuropathic pain condition. We evaluated visual subjective body-midline (vSM) representation in 27 patients with post-herpetic neuralgia (PHN) and 22 with CRPS under light and dark conditions. A red laser dot was projected onto a screen and moved horizontally towards the sagittal plane of the objective body-midline (OM). Each participant was asked to direct the dot to a position where it crossed their vSM. The distance between the vSM and OM was analysed to determine how and in which direction the vSM deviated. Under light condition, all vSM judgments approximately matched the OM. However, in the dark, CRPS patients, but not PHN patients, showed a shifted vSM towards the affected side. We demonstrated that chronic pain does not always impair visuospatial perception. The aetiology of PHN is limited to the peripheral nervous system, whereas the distorted visuospatial perception suggests a supraspinal aetiology of CRPS.

  12. Cortical underconnectivity coupled with preserved visuospatial cognition in autism: Evidence from an fMRI study of an embedded figures task.

    Science.gov (United States)

    Damarla, Saudamini Roy; Keller, Timothy A; Kana, Rajesh K; Cherkassky, Vladimir L; Williams, Diane L; Minshew, Nancy J; Just, Marcel Adam

    2010-10-01

    Individuals with high-functioning autism sometimes exhibit intact or superior performance on visuospatial tasks, in contrast to impaired functioning in other domains such as language comprehension, executive tasks, and social functions. The goal of the current study was to investigate the neural bases of preserved visuospatial processing in high-functioning autism from the perspective of the cortical underconnectivity theory. We used a combination of behavioral, functional magnetic resonance imaging, functional connectivity, and corpus callosum morphometric methodological tools. Thirteen participants with high-functioning autism and 13 controls (age-, IQ-, and gender-matched) were scanned while performing an Embedded Figures Task. Despite the ability of the autism group to attain behavioral performance comparable to the control group, the brain imaging results revealed several group differences consistent with the cortical underconnectivity account of autism. First, relative to controls, the autism group showed less activation in the left dorsolateral prefrontal and inferior parietal areas and more activation in visuospatial (bilateral superior parietal extending to inferior parietal and right occipital) areas. Second, the autism group demonstrated lower functional connectivity between higher-order working memory/executive areas and visuospatial regions (between frontal and parietal-occipital). Third, the size of the corpus callosum (an index of anatomical connectivity) was positively correlated with frontal-posterior (parietal and occipital) functional connectivity in the autism group. Thus, even in the visuospatial domain, where preserved performance among people with autism is observed, the neuroimaging signatures of cortical underconnectivity persist.

  13. 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.

  14. 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

    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. 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. 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. 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.

  15. Neural correlates of visuospatial bias in patients with left hemisphere stroke: a causal functional contribution analysis based on game theory.

    Science.gov (United States)

    Malherbe, C; Umarova, R M; Zavaglia, M; Kaller, C P; Beume, L; Thomalla, G; Weiller, C; Hilgetag, C C

    2017-10-12

    Stroke patients frequently display spatial neglect, an inability to report, or respond to, relevant stimuli in the contralesional space. Although this syndrome is widely considered to result from the dysfunction of a large-scale attention network, the individual contributions of damaged grey and white matter regions to neglect are still being disputed. Moreover, while the neuroanatomy of neglect in right hemispheric lesions is well studied, the contributions of left hemispheric brain regions to visuospatial processing are less well understood. To address this question, 128 left hemisphere acute stroke patients were investigated with respect to left- and rightward spatial biases measured as severity of deviation in the line bisection test and as Center of Cancellation (CoC) in the Bells Test. Causal functional contributions and interactions of nine predefined grey and white matter regions of interest in visuospatial processing were assessed using Multi-perturbation Shapley value Analysis (MSA). MSA, an inference approach based on game theory, constitutes a robust and exact multivariate mathematical method for inferring functional contributions from multi-lesion patterns. According to the analysis of performance in the Bells test, leftward attentional bias (contralesional deficit) was associated with contributions of the left superior temporal gyrus and rightward attentional bias with contributions of the left inferior parietal lobe, whereas the arcuate fascicle was contributed to both contra- and ipsilesional bias. Leftward and rightward deviations in the line bisection test were related to contributions of the superior longitudinal fascicle and the inferior parietal lobe, correspondingly. Thus, Bells test and line bisection tests, as well as ipsi- and contralesional attentional biases in these tests, have distinct neural correlates. Our findings demonstrate the contribution of different grey and white matter structures to contra- and ipsilesional spatial biases as

  16. Involuntary memories after a positive film are dampened by a visuospatial task: unhelpful in depression but helpful in mania?

    Science.gov (United States)

    Davies, Charlotte; Malik, Aiysha; Pictet, Arnaud; Blackwell, Simon E; Holmes, Emily A

    2012-01-01

    Spontaneous negative mental images have been extensively researched due to the crucial role they play in conditions such as post-traumatic stress disorder. However, people can also experience spontaneous positive mental images, and these are little understood. Positive images may play a role in promoting healthy positive mood and may be lacking in conditions such as depression. However, they may also occur in problematic states of elevated mood, such as in bipolar disorder. Can we apply an understanding of spontaneous imagery gained by the study of spontaneous negative images to spontaneous positive images? In an analogue of the trauma film studies, 69 volunteers viewed an explicitly positive (rather than traumatic) film. Participants were randomly allocated post-film either to perform a visuospatial task (the computer game 'Tetris') or to a no-task control condition. Viewing the film enhanced positive mood and immediately post-film increased goal setting on a questionnaire measure. The film was successful in generating involuntary memories of specific scenes over the following week. As predicted, compared with the control condition, participants in the visuospatial task condition reported significantly fewer involuntary memories from the film in a diary over the subsequent week. Furthermore, scores on a recognition memory test at 1 week indicated an impairment in voluntary recall of the film in the visuospatial task condition. Clinical implications regarding the modulation of positive imagery after a positive emotional experience are discussed. Generally, boosting positive imagery may be a useful strategy for the recovery of depressed mood. Copyright © 2012 John Wiley & Sons, Ltd.

  17. 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

    2017-11-01

    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.

  18. Role of visuo-spatial short-term memory on vocabulary learning of Sign Language as a second language

    OpenAIRE

    松見, 法男

    2005-01-01

    Two experiments were designed to investigate a role of visuo-spatial short-term memory on vocabulary learning of Sign Language as a second language. The subjects having no experiences of Sign Language learning were required to encode Sign Language new words by associating with their meaning (presented in Japanese words) in both experiments. A2×2×3 factorial design was used in experiment 1: the first variable was with or without spatial concurrent task, the second was high- or low-imagery of t...

  19. Comparative Analysis of Termiteria and Surrounding Soil Properties ...

    African Journals Online (AJOL)

    Comparative Analysis of Termiteria and Surrounding Soil Properties in the University of Agriculture, Makurdi, Nigeria. IS Eneji, R Sha'Ato, SE Ejembi. Abstract. Variations in the properties of termitaria and their surrounding soil properties within the University of Agriculture Makurdi were investigated using routine soil analysis ...

  20. The bird species of pandam wildlife park and the surrounding ...

    African Journals Online (AJOL)

    This study investigated the bird species abundance and diversity of the Pandam wildlife park and the surrounding farmlands. The effect of time of day as well as vegetation variables on bird species diversity in the park and surrounding farmlands was also conducted. 10 transects in each study site were surveyed twice ...

  1. HIV behavioural surveillance among refugees and surrounding host ...

    African Journals Online (AJOL)

    We used a standardised behavioural surveillance survey (BSS), modified to be directly relevant to populations in conflict and post-conflict settings as well as to their surrounding host populations, to survey the populations of a refugee settlement in south-western Uganda and its surrounding area. Two-stage probability ...

  2. Spatial and visuospatial working memory tests predict performance in classic multiple-object tracking in young adults, but nonspatial measures of the executive do not.

    Science.gov (United States)

    Trick, Lana M; Mutreja, Rachna; Hunt, Kelly

    2012-02-01

    An individual-differences approach was used to investigate the roles of visuospatial working memory and the executive in multiple-object tracking. The Corsi Blocks and Visual Patterns Tests were used to assess visuospatial working memory. Two relatively nonspatial measures of the executive were used: operation span (OSPAN) and reading span (RSPAN). For purposes of comparison, the digit span test was also included (a measure not expected to correlate with tracking). The tests predicted substantial amounts of variance (R (2) = .33), and the visuospatial measures accounted for the majority (R (2) = .30), with each making a significant contribution. Although the executive measures correlated with each other, the RSPAN did not correlate with tracking. The correlation between OSPAN and tracking was similar in magnitude to that between digit span and tracking (p executive, as measured by tests such as the OSPAN, plays little role in explaining individual differences in multiple-object tracking.

  3. 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 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 inhibit cross-modal reorganization in early deaf subjects. Granger

  4. Exergames Encouraging Exploration of Hemineglected Space in Stroke Patients With Visuospatial Neglect: A Feasibility Study.

    Science.gov (United States)

    Tobler-Ammann, Bernadette C; Surer, Elif; de Bruin, Eling D; Rabuffetti, Marco; Borghese, N Alberto; Mainetti, Renato; Pirovano, Michele; Wittwer, Lia; Knols, Ruud H

    2017-08-25

    Use of exergames can complement conventional therapy and increase the amount and intensity of visuospatial neglect (VSN) training. A series of 9 exergames-games based on therapeutic principles-aimed at improving exploration of the neglected space for patients with VSN symptoms poststroke was developed and tested for its feasibility. The goal was to determine the feasibility of the exergames with minimal supervision in terms of (1) implementation of the intervention, including adherence, attrition and safety, and (2) limited efficacy testing, aiming to document possible effects on VSN symptoms in a case series of patients early poststroke. A total of 7 patients attended the 3-week exergames training program on a daily basis. Adherence of the patients was documented in a training diary. For attrition, the number of participants lost during the intervention was registered. Any adverse events related to the exergames intervention were noted to document safety. Changes in cognitive and spatial exploration skills were measured with the Zürich Maxi Mental Status Inventory and the Neglect Test. Additionally, we developed an Eye Tracker Neglect Test (ETNT) using an infrared camera to detect and measure neglect symptoms pre- and postintervention. The median was 14 out of 15 (93%) attended sessions, indicating that the adherence to the exergames training sessions was high. There were no adverse events and no drop-outs during the exergame intervention. The individual cognitive and spatial exploration skills slightly improved postintervention (P=.06 to P=.98) and continued improving at follow-up (P=.04 to P=.92) in 5 out of 7 (71%) patients. Calibration of the ETNT was rather error prone. The ETNT showed a trend for a slight median group improvement from 15 to 16 total located targets (+6%). The high adherence rate and absence of adverse events showed that these exergames were feasible and safe for the participants. The results of the amount of exergames use is promising for

  5. Computerized visuo-spatial memory test as a supplementary screening test for dementia.

    Science.gov (United States)

    Maki, Yohko; Yoshida, Hiroshi; Yamaguchi, Haruyasu

    2010-06-01

    To prepare for a super-aging society, effective dementia screening tests are required. The most salient deficit appearing from the early stages of dementia/Alzheimer's disease (AD) is a deterioration in memory. The Hasegawa Dementia Scale-revised (HDS-R) and the Mini-Mental State Examination (MMSE) are widely used in Japan to screen for dementia. Both place an emphasis on memory function, but neither examines visuo-spatial memory (VSM) function, even though VSM deficits are a sensitive marker for the detection of conversion to dementia. Furthermore, brief tests of VSM that are appropriate for screening have not been standardized. Thus, in the present study, we devised a brief, computer-aided short-term VSM test. Sixty-six aged people were evaluated. Using the Clinical Dementia Rating (CDR), it was found that 29 could be considered normal controls (NC; CDR 0), 10 had mild cognitive impairment (MCI; CDR 0.5), 15 had mild dementia (CDR 1), and 12 had moderate to severe dementia (CDR 2-3). The VSM test estimated how many locations each subject could memorize. Several numbered circles were shown on a monitor and subjects were required to memorize the location of these circles sequentially. After the numbers on the circles on the screen had disappeared, the subjects were required to indicate the circles in ascending order. A touch panel screen was used for this test to make it easier. The HDS-R was applied to subjects with MCI and dementia. The mean (+/-SD) VSM score in subjects with MCI (5.70 +/- 0.96) was significantly lower than that in NC subjects (6.69 +/- 0.82), but significantly higher than that in subjects classified as CDR 1 (4.67 +/- 0.87). There was no significant difference in VSM scores between subjects classified as CDR 1 and CDR 2-3 (3.80 +/- 0.80). There was a moderate significant correlation between VSM and HDS-R scores. In the present study, the VSM test detected differences in VSM function among NC subjects and subjects with MCI and mild dementia. The

  6. 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

    -level abnormalities. The C-SST improves the reliability and sensitivity of spatial span testing, can accurately detect malingering, and shows that visuospatial working memory is largely preserved in patients with predominantly mild TBI.

  7. Pre-chemotherapy differences in visuospatial working memory in breast cancer patients compared to controls: An fMRI study.

    Directory of Open Access Journals (Sweden)

    Carole Susan Scherling

    2011-11-01

    Full Text Available IntroductionCognitive deficits are a side-effect of chemotherapy, however pre-treatment research is limited. This study examines neurofunctional differences during working memory between breast cancer (BC patients and controls, prior to chemotherapy. MethodsEarly stage BC females (23, scanned after surgery but before chemotherapy, were individually matched to non-cancer controls. Participants underwent fMRI while performing a Visuospatial N-back task and data was analyzed by multiple group comparisons. fMRI task performance, neuropsychological tests, hospital records and salivary biomarkers were also collected.ResultsThere were no significant group differences on neuropsychological tests, estrogen or cortisol. Patients made significantly fewer commission errors but had less overall correct responses and were slower than controls during the task. Significant group differences were observed for the fMRI data, yet results depended on the type of analysis. BC patients presented with increased activations during working memory compared to controls in areas such as the inferior frontal gyrus, insula, thalamus, and midbrain. Individual group regressions revealed a reverse relationship between brain activity and commission errors. ConclusionsThis is the first fMRI investigation to reveal neurophysiological differences during visuospatial working memory between BC patients pre-chemotherapy and controls.SignificanceThis highlights the need to better understand the pre-chemotherapy BC patient and the effects of associated confounding variables.

  8. Mutation of the dyslexia-associated gene Dcdc2 impairs LTM and visuo-spatial performance in mice.

    Science.gov (United States)

    Gabel, L A; Marin, I; LoTurco, J J; Che, A; Murphy, C; Manglani, M; Kass, S

    2011-11-01

    Developmental reading disorder (RD) affects 5-10% of school aged children, with a heritability of approximately 60%. Genetic association studies have identified several candidate RD susceptibility genes, including DCDC2; however, a direct connection between the function of these genes and cognitive or learning impairments remains unclear. Variants in DCDC2, a member of the doublecortin family of genes, have been associated in humans with RD and ADHD and Dcdc2 may play a role in neuronal migration in rats. In this study, we examined the effect of Dcdc2 mutation on cognitive abilities in mice using a visual attention and visuo-spatial learning and memory task. We show that both heterozygous and homozygous mutations of Dcdc2 result in persistent visuo-spatial memory deficits, as well as visual discrimination and long-term memory deficits. These behavioral deficits occur in the absence of neuronal migration disruption in the mutant mice, and may be comorbid with an anxiety phenotype. These are the first results to suggest a direct relationship between induced mutation in Dcdc2 and changes in behavioral measures. Dcdc2 mutant mice should prove useful in future studies designed to further dissect the underlying neural mechanisms that are impaired following Dcdc2 mutation. © 2011 The Authors. Genes, Brain and Behavior © 2011 Blackwell Publishing Ltd and International Behavioural and Neural Genetics Society.

  9. Look who's talking: the deployment of visuo-spatial attention during multisensory speech processing under noisy environmental conditions.

    Science.gov (United States)

    Senkowski, Daniel; Saint-Amour, Dave; Gruber, Thomas; Foxe, John J

    2008-11-01

    In a crowded scene we can effectively focus our attention on a specific speaker while largely ignoring sensory inputs from other speakers. How attended speech inputs are extracted from similar competing information has been primarily studied in the auditory domain. Here we examined the deployment of visuo-spatial attention in multiple speaker scenarios. Steady-state visual evoked potentials (SSVEP) were monitored as a real-time index of visual attention towards three competing speakers. Participants were instructed to detect a target syllable by the center speaker and ignore syllables from two flanking speakers. The study incorporated interference trials (syllables from three speakers), no-interference trials (syllable from center speaker only), and periods without speech stimulation in which static faces were presented. An enhancement of flanking speaker induced SSVEP was found 70-220 ms after sound onset over left temporal scalp during interference trials. This enhancement was negatively correlated with the behavioral performance of participants -- those who showed largest enhancements had the worst speech recognition performance. Additionally, poorly performing participants exhibited enhanced flanking speaker induced SSVEP over visual scalp during periods without speech stimulation. The present study provides neurophysiologic evidence that the deployment of visuo-spatial attention to flanking speakers interferes with the recognition of multisensory speech signals under noisy environmental conditions.

  10. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Mental subtraction and multiplication recruit both phonological and visuospatial resources: evidence from a symmetric dual-task design.

    Science.gov (United States)

    Cavdaroglu, Seda; Knops, A

    2016-07-01

    Previous studies pointed out a selective interaction between different working memory subsystems (i.e., phonological and visuospatial) and arithmetic operations (i.e., multiplication and subtraction). This was interpreted to support the idea that multiplication and subtraction predominantly rely on a phonologically or spatially organized number code, respectively. Here, we investigated this idea in two groups (multiplication and subtraction group) using a dual-task paradigm. Going beyond previous studies, we carefully controlled and balanced the difficulty of both working memory and calculation tasks within and across participants. This allowed us to test the reciprocal impact of calculations on working memory. We observed no selective interaction between different working memory subsystems and arithmetic operations. Instead, both types of arithmetic operations were impaired by both types of concurrent working memory tasks. Likewise, both types of working memory tasks were impaired by both types of concurrent arithmetic. Our findings suggest that multiplication and subtraction depend on both phonological and visuospatial codes and highlight the importance of balancing task demands within and between participants in the context of dual-task studies.

  12. 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.

  13. Δ⁹Tetrahydrocannabinol impairs visuo-spatial associative learning and spatial working memory in rhesus macaques.

    Science.gov (United States)

    Taffe, Michael A

    2012-10-01

    Cannabis remains the most commonly abused illicit drug and is rapidly expanding in quasi-licit use in some jurisdictions under medical marijuana laws. Effects of the psychoactive constituent Δ⁹tetrahydrocannabinol (Δ⁹THC) on cognitive function remain of pressing concern. Prior studies in monkeys have not shown consistent evidence of memory-specific effects of Δ⁹THC on recognition tasks, and it remains unclear to what extent Δ⁹THC causes sedative versus specific cognitive effects. In this study, adult male rhesus monkeys were trained on tasks which assess spatial working memory, visuo-spatial associative memory and learning as well as motivation for food reward. Subjects were subsequently challenged with 0.1-0.3 mg/kg Δ⁹THC, i.m., in randomized order and evaluated on the behavioral measures. The performance of both vsPAL and SOSS tasks was impaired by Δ⁹THC in a dose and task-difficulty dependent manner. It is concluded that Δ⁹THC disrupts cognition in a way that is consistent with a direct effect on memory. There was evidence for interference with spatial working memory, visuo-spatial associative memory and incremental learning in the latter task. These results and the lack of specific effect of Δ⁹THC in prior visual recognition studies imply a sensitivity of spatial memory processing and/or working memory to endocannabinoid perturbation.

  14. 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.

  15. 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.

  16. 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…

  17. Exploratory study of the relationship between the musical, visuospatial, bodily-kinesthetic intelligence and drive creativity in the process of learning

    Directory of Open Access Journals (Sweden)

    Paula MARCHENA CRUZ

    2017-12-01

    Full Text Available Currently, the Spanish educational system focuses its attention on the development of priority subjects such as language and mathematics versus other secondary such as music (Palacios, 2006, without considering numerous neuropsychological research that provides new theories of mind and learning that can positively influence the transformation of current educational models (Martin-Lobo, 2015. This research aims to determine the relation between musical intelligence, bodily-kinesthetic intelligence, intelligence visuospatial and motor creativity in a sample among 5 years old students from the last year of Early Childhood Education. The instrument used to assess the three intelligences, based on Gardner’s theory, was the Multiple Intelligences questionnaire for children of pre-school age (Prieto and Ballester, 2003; for the evaluation of motor creativity was used Test of Creative Thinking in Action and Movement (Torrance, Reisman and Floyd, 1981. A descriptive and correlational statistical analysis (using the Pearson correlation index applying the Microsoft Excel program along with the supplement known as Ezanalyze. The results indicated no significant relationship between musical intelligence and motor creativity (p = 0.988; the visuospatial intelligence and motor creativity (p = 0.992; and the bodily-kinesthetic intelligence and motor creativity (p = 0.636. Although there was significant relation between the musical and visuospatial intelligence (p = 0.000; the musical and bodily-kinesthetic intelligence (p = 0.000; and the bodily-kinesthetic and visuospatial intelligence (p = 0.025.

  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. Abnormalities in Pattern of Lateralization in Relation to Visuospatial Short Term Memory in Children with Williams Syndrome

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    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.

  20. Low-frequency transcranial magnetic stimulation over left dorsal premotor cortex improves the dynamic control of visuospatially cued actions

    DEFF Research Database (Denmark)

    Ward, Nick S; Bestmann, Sven; Hartwigsen, Gesa

    2010-01-01

    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 min of low-frequency (1 Hz) 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 the right or left index finger in response to a left- or right-sided target. Subjects were...... that left rPMd and SMG-AIP contribute toward 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....

  1. 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 age 6 (ELBW 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.

  2. 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

  3. Individuals with mild MS with poor sleep quality have impaired visuospatial memory and lower perceived functional abilities.

    Science.gov (United States)

    Siengsukon, Catherine F; Aldughmi, Mayis; Kahya, Melike; Lynch, Sharon; Bruce, Jared; Glusman, Morgan; Ness Norouzinia, Abigail; Billinger, Sandra

    2017-04-29

    Sleep disturbances are common in individuals with Multiple Sclerosis (MS), but the impact of poor sleep quality on cognitive and physical function in individuals with MS is less clear. The purpose of this study was to examine the relationship between sleep quality and cognitive and physical function in individuals with mild MS. Forty individuals with relapsing-remitting or secondary-progressive MS (50.3 ± 11.6 years of age) participated. The Pittsburgh Sleep Quality Index (PSQI) was used to index sleep quality. A PSQI of ≤5 was considered good sleep quality and >5 was considered poor sleep quality. Cognitive function was assessed using a battery of cognitive tests, and physical function was assessed using 2 objective measures and a self-report measure. Thirteen individuals (32.5%) indicated good sleep quality and 27 (67.5%) of the participants reported poor sleep quality. Those with good sleep quality performed significantly better on a visuospatial memory test (p = 0.025) and reported higher functional abilities (p poor sleep quality. There was no difference in performance on the cognitive tests of verbal memory, information processing, or executive function, or the objective function measures. Individuals with poor sleep quality had higher levels of fatigue, depression, and anxiety, and lower quality of life. Visuospatial memory appears to be the memory domain particularly associated with poor sleep quality in people with mild MS. Also, individuals with mild MS with poor sleep quality may underestimate their functional abilities. Copyright © 2017. Published by Elsevier Inc.

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

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    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

  5. The pattern of verbal, visuospatial and procedural learning in Richardson variant of progressive supranuclear palsy in comparison to Parkinson's disease.

    Science.gov (United States)

    Sitek, Emilia J; Wieczorek, Dariusz; Konkel, Agnieszka; Dąbrowska, Magda; Sławek, Jarosław

    2017-08-29

    Progressive supranuclear palsy (PSP) is regarded either within spectrum of atypical parkinsonian syndromes or frontotemporal lobar degeneration. We compared the verbal, visuospatial and procedural learning profiles in patients with PSP and Parkinson's disease (PD). Furthermore, the relationship between executive factors (initiation and inhibition) and learning outcomes was analyzed. Thirty-three patients with the clinical diagnosis of PSP-Richardson's syndrome (PSP-RS), 39 patients with PD and 29 age -and education -matched controls were administered Mini-Mental State Examination (MMSE), phonemic and semantic fluency tasks, Auditory Verbal Learning Test (AVLT), Visual Learning and Memory Test for Neuropsychological Assessment by Lamberti and Weidlich (Diagnosticum für Cerebralschädigung, DCS), Tower of Toronto (ToT) and two motor sequencing tasks. Patients with PSP-RS and PD were matched in terms of MMSE scores and mood. Performance on DCS was lower in PSP-RS than in PD. AVLT delayed recall was better in PSP-RS than PD. Motor sequencing task did not differentiate between patients. Scores on AVLT correlated positively with phonemic fluency scores in both PSP-RS and PD. ToT rule violation scores were negatively associated with DCS performance in PSP-RS and PD as well as with AVLT performance in PD. Global memory performance is relatively similar in PSP-RS and PD. Executive factors (initiation and inhibition) are closely related to memory performance in PSP-RS and PD. Visuospatial learning impairment in PSP-RS is possibly linked to impulsivity and failure to inhibit automatic responses.

  6. Impact of anxiety on verbal and visuospatial working memory in patients with acute stroke without severe cognitive impairment.

    Science.gov (United States)

    Grosdemange, Antoine; Monfort, Vincent; Richard, Sébastien; Toniolo, Anne-Marie; Ducrocq, Xavier; Bolmont, Benoît

    2015-05-01

    Working memory is the most impaired cognitive domain in the acute phase of stroke. In a context where anxiety is highly prevalent, close attention must be paid to anxiety which could mimic mild to moderate working memory impairments. This is the first study to assess the contribution of state anxiety (the currently experienced level of anxiety) to the working memory (verbal, visuospatial) in patients with first-ever acute stroke without severe cognitive impairment. 28 patients with first-ever acute stroke and 41 matched control subjects were exposed to a neutral condition and an anxiogenic condition in which verbal (VWM) and visuospatial working memory (VSWM) performance and state anxiety were assessed. State anxiety was assessed before the beginning of the experiment (baseline), after the neutral condition and after the anxiogenic condition. The mean state anxiety score was higher in patients than in controls in the neutral (z = 1.9, p<0.05) and anxiogenic (z = 2, p<0.05) conditions despite a similar level at baseline. Multiple regression analyses with a dummy variable 'group' (patients vs controls) showed that increased state anxiety in patients contributed significantly more to both reduced VWM (β = -0.93, p<0.05) and VSWM (β = -1, p<0.05) performance between the neutral and anxiogenic conditions compared to controls. In a stressful context, the contribution of state anxiety to reduced working memory performance is more pronounced in patients with acute stroke than in controls. These results are of particular relevance for clinicians assessing patients in the acute phase of stroke in which anxiety is highly prevalent. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Developmental changes in visuo-spatial working memory in normally developing children: event-related potentials study.

    Science.gov (United States)

    Myatchin, Ivan; Lagae, Lieven

    2013-10-01

    Working memory (WM) is very important for normal development. The fronto-parietal neuronal network supporting WM has already been well-studied. Less is known about the cortical activity changes during development of WM. We evaluated the maturation of visual WM network at the electrophysiological level in a group of normally developing children. Multichannel (n=31) event-related potentials (ERP) were measured during a visuo-spatial backmatching task in 69 childrens (6-16 years old). One-backmatching (BM1) and two-backmatching (BM2) tasks were performed. Age-related changes in behavioral parameters (commission and omission errors and reaction times) and ERP parameters (peak amplitudes and latencies) were analyzed between different ages. Clear improvement in performance from young childhood toward adolescence was seen at the behavioral level: decrease of errors and fastening of reaction times. At the electrophysiological level age-related changes were seen in peak latencies and especially in amplitudes. Different peaks have different dynamics in amplitudes and latencies: early peak amplitude decreased and latency shortened with age, which was not always seen in late peaks. This reflects developmental changes in intensity and speed of WM processing. Later peaks were more clearly seen over the right hemisphere in older children, illustrating hemispheric lateralization in visuo-spatial working memory. Our results indicate that not only at the behavioral but also at the electrophysiological level clear age-related dynamics in WM processing can be seen. Furthermore, with ERP we showed that different WM components follow different developmental trajectories. Our work demonstrates that age-related dynamics in intensity and speed of information processing during WM task is reflected in developmental changes in different ERP components. It also states that fronto-parietal visual WM network can be functional even before all its nodes are fully mature. Copyright © 2012 The

  8. Eccrine syringofibroadenoma surrounding a squamous cell carcinoma: a case report.

    Science.gov (United States)

    Lele, S M; Gloster, E S; Heilman, E R; Chen, P C; Chen, C K; Anzil, A P; Pozner, J N; Reardon, M J

    1997-03-01

    A 91-year-old man presented with a 9.0 x 7.0 cm exophytic mass on the dorsum of the right foot, surrounded by a scaling hyperkeratotic plaque-like lesion that had been present for many years. He had similar long-standing hyperkeratotic plaque-like lesions on both legs. Histopathologic examination of the exophytic mass revealed a well-differentiated squamous cell carcinoma surrounded by an eccrine syringofibroadenoma (ESFA). Histochemistry, immunohistochemistry and electron microscopy support this diagnosis. To our knowledge, this is the only reported case of ESFA being intimately associated with a malignant neoplasm.

  9. A 500 PARSEC HALO SURROUNDING THE GALACTIC GLOBULAR NGC 1851

    NARCIS (Netherlands)

    Olszewski, Edward W.; Saha, Abhijit; Knezek, Patricia; Subramaniam, Annapurni; de Boer, Thomas; Seitzer, Patrick

    2009-01-01

    Using imaging that shows 4 mag 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

  10. Influence of surroundings on photorefractive effect in lithium niobate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Tarjanyi, Norbert, E-mail: tarjanyi@fyzika.uniza.sk [Department of Physics, Faculty of Electrical Engineering, University of Zilina, Univerzitna 1, Zilina, 01026 (Slovakia); Turek, Ivan [Berlinska 4, Zilina, 01008 (Slovakia)

    2012-11-01

    In the paper results of the investigation of the influence of electric properties of the environment surrounding LiNbO{sub 3} crystals on photorefractive effect induced in these crystals by Gaussian Ar{sup +} laser beam with various intensities are presented. We show spatial and temporal dependences of changes of the refractive index obtained experimentally in LiNbO{sub 3}: Fe and LiNbO{sub 3}: Fe:Mn samples surrounded by media with different electric conductivities and different permittivities (water, air, water solution of CaCl{sub 2}). The space and time dependences of the refractive index changes induced by the Ar{sup +} laser beam are observed by means of the Mach-Zehnder interferometer using light from HeNe laser. The experimentally obtained results are in a good agreement with those following from numerical calculations using the manifold mirroring method. The agreement between calculated and experimental results indicates that the polarization charge at the photorefractive crystal/surrounding medium boundary significantly influences the photorefractive process in the crystal. The experimentally observed slow spontaneous decrease of the refractive index change in a sample placed into a slightly conducting medium (air) after switching off the beam also indicates that the polarization charge in the sample's surroundings affects the photorefraction.

  11. Placental vascular responses are dependent on surrounding tissue

    DEFF Research Database (Denmark)

    Brøgger, Torbjørn Halle

    . Materials and methods. From fresh born placentas, stem villi arteries were carefully dissected. The artery branches were divided. The surrounding tissue was removed from one end and was left untouched in the other end.Then, using wire myography, they were investigated in terms of contractility...

  12. Acrylate in Phaeocystis colonies does not affect the surrounding bacteria

    NARCIS (Netherlands)

    Noordkamp, DJB; Gieskes, WWC; Gottschal, JC; Forney, LJ; van Rijssel, M

    Acrylate accumulates to concentrations of 1.3-6.5 mM in the mucus of Phaeocystis colonies and may have an effect on the surrounding bacterial community, either as an inhibitor or as a carbon source. Both in the held and in the laboratory, effects of acrylate on bacterial growth and on its

  13. Traditional Indian customs surrounding birth A review | Chalmers ...

    African Journals Online (AJOL)

    Since 1960, only a few studies have been made of traditional custOIns surrounding birth in Indian culture. Very few of these have described customs followed by Indians in South Africa. A review of these publications is presented here. Customs described include religious, social and psychological aspects of behaviour in ...

  14. Smart Signs: Showing the way in Smart Surroundings

    NARCIS (Netherlands)

    Lijding, M.E.M.; Benz, H.P.; Meratnia, Nirvana; Havinga, Paul J.M.

    This paper presents a context-aware guidance and messaging system for large buildings and surrounding venues. Smart Signs are a new type of electronic door- and way-sign based on wireless sensor networks. Smart Signs present in-situ personalized guidance and messages, are ubiquitous, and easy to

  15. Review of Ordered Anarchy: Jasay and his Surroundings

    Directory of Open Access Journals (Sweden)

    Aschwin de Wolf

    2009-02-01

    Full Text Available Anthony de Jasay is among the most important social thinkers of our time. His oeuvre offers a sustained critique of government and its defenders. In the book Ordered Anarchy: Jasay and His Surroundings, colleagues and friends pay tribute to the man in the form of an inspiring collection of essays.

  16. Polluted Alamuyo River: Impacts on surrounding wells, microbial ...

    African Journals Online (AJOL)

    Polluted Alamuyo River: Impacts on surrounding wells, microbial attributes and toxic effects on Allium cepa root cells. ... High microbial load was observed in river water samples compared to the well water samples throughout the sampling periods with overall highest value observed at Late Rainy Season upstream water ...

  17. 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...

  18. Modeling grating contrast discrimination dippers: The role of surround suppression.

    Science.gov (United States)

    To, Michelle P S; Chirimuuta, Mazviita; Tolhurst, David J

    2017-10-01

    We consider the role of nonlinear inhibition in physiologically realistic multineuronal models of V1 to predict the dipper functions from contrast discrimination experiments with sinusoidal gratings of different geometries. The dip in dipper functions has been attributed to an expansive transducer function, which itself is attributed to two nonlinear inhibitory mechanisms: contrast normalization and surround suppression. We ran five contrast discrimination experiments, with targets and masks of different sizes and configurations: small Gabor target/small mask, small target/large mask, large target/large mask, small target/in-phase annular mask, and small target/out-of-phase annular mask. Our V1 modeling shows that the results for small Gabor target/small mask, small target/large mask, large target/large mask configurations are easily explained only if the model includes surround suppression. This is compatible with the finding that an in-phase annular mask generates only little threshold elevation while the out-of-phase mask was more effective. Surrounding mask gratings cannot be equated with surround suppression at the receptive-field level. We examine whether normalization and surround suppression occur simultaneously (parallel model) or sequentially (a better reflection of neurophysiology). The Akaike Criterion Difference showed that the sequential model was better than the parallel, but the difference was small. The large target/large mask dipper experiment was not well fit by our models, and we suggest that this may reflect selective attention for its uniquely larger test stimulus. The best-fit model replicates some behaviors of single V1 neurons, such as the decrease in receptive-field size with increasing contrast.

  19. Kinetic theory of plasma sheaths surrounding electron-emitting surfaces.

    Science.gov (United States)

    Sheehan, J P; Hershkowitz, N; Kaganovich, I D; Wang, H; Raitses, Y; Barnat, E V; Weatherford, B R; Sydorenko, D

    2013-08-16

    A one-dimensional kinetic theory of sheaths surrounding planar, electron-emitting surfaces is presented which accounts for plasma electrons lost to the surface and the temperature of the emitted electrons. It is shown that ratio of plasma electron temperature to emitted electron temperature significantly affects the sheath potential when the plasma electron temperature is within an order of magnitude of the emitted electron temperature. The sheath potential goes to zero as the plasma electron temperature equals the emitted electron temperature, which can occur in the afterglow of an rf plasma and some low-temperature plasma sources. These results were validated by particle in cell simulations. The theory was tested by making measurements of the sheath surrounding a thermionically emitting cathode in the afterglow of an rf plasma. The measured sheath potential shrunk to zero as the plasma electron temperature cooled to the emitted electron temperature, as predicted by the theory.

  20. Trajectories and Maneuvers of Surrounding Vehicles with Panoramic Camera Arrays

    DEFF Research Database (Denmark)

    Dueholm, Jacob Velling; Kristoffersen, Miklas Strøm; Satzoda, Ravi K.

    2016-01-01

    of drive on US highways. The multiperspective tracker is tested in each view as well as for the ability to associate vehicles bet-ween views with a 92% recall score. A case study of vehicles approaching from the rear shows certain patterns in behavior that could potentially influence the ego-vehicle.......Vision-based research for intelligent vehicles have traditionally focused on specific regions around a vehicle, such as a front looking camera for, e.g., lane estimation. Traffic scenes are complex and vital information could be lost in unobserved regions. This paper proposes a framework that uses...... four visual sensors for a full surround view of a vehicle in order to achieve an understanding of surrounding vehicle behaviors. The framework will assist the analysis of naturalistic driving studies by automating the task of data reduction of the observed trajectories. To this end, trajectories...

  1. Circuits and Mechanisms for Surround Modulation in Visual Cortex.

    Science.gov (United States)

    Angelucci, Alessandra; Bijanzadeh, Maryam; Nurminen, Lauri; Federer, Frederick; Merlin, Sam; Bressloff, Paul C

    2017-07-25

    Surround modulation (SM) is a fundamental property of sensory neurons in many species and sensory modalities. SM is the ability of stimuli in the surround of a neuron's receptive field (RF) to modulate (typically suppress) the neuron's response to stimuli simultaneously presented inside the RF, a property thought to underlie optimal coding of sensory information and important perceptual functions. Understanding the circuit and mechanisms for SM can reveal fundamental principles of computations in sensory cortices, from mouse to human. Current debate is centered over whether feedforward or intracortical circuits generate SM, and whether this results from increased inhibition or reduced excitation. Here we present a working hypothesis, based on theoretical and experimental evidence, that SM results from feedforward, horizontal, and feedback interactions with local recurrent connections, via synaptic mechanisms involving both increased inhibition and reduced recurrent excitation. In particular, strong and balanced recurrent excitatory and inhibitory circuits play a crucial role in the computation of SM.

  2. Belief and Attitudes surrounding Childhood Autism in Ghana

    OpenAIRE

    Manu, Naomi

    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...

  3. 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.

  4. Enhanced sources of acoustic power surrounding AR 11429

    Science.gov (United States)

    Donea, Alina; Hanson, Christopher

    2013-06-01

    Multi-frequency power maps of the local acoustic oscillations show acoustic enhancements ("acoustic-power halos") at high frequencies surrounding large active region. Computational seismic holography reveals a high-frequency "acoustic-emission halo", or "seismic glory" surrounding large active regions. In this study, we have applied computational seismic holography to map the seismic seismic source density surrounding AR 11429. Studies of HMI/SDO Doppler data, shows that the "acoustic halos" and the "seismic glories" are prominent at high frequencies 5-8 mHz. We investigate morphological properties of acoustic-power and acoustic emission halos around an active region to see if they are spatially correlated. Details about the local magnetic field from vectormagnetograms of AR 11429 are included. We identify a 15" region of seismic deficit power (dark moat) shielding the white-light boundary of the active region. The size of the seismic moat is related to region of intermediate magnetic field strength. The acoustic moat is circled by the halo of enhanced seismic amplitude as well as enhanced seismic emission. Overall, the results suggest that features are related. However, if we narrow the frequency band to 5.5 - 6.5 mHz, we find that the seismic source density dominates over the local acoustic power, suggesting the existence of sources that emit more energy downward into the solar interior than upward toward the solar surface.

  5. Balance Regularity Among Former High School Football Players With or Without a History of Concussion.

    Science.gov (United States)

    Schmidt, Julianne D; Terry, Douglas P; Ko, Jihyun; Newell, Karl M; Miller, L Stephen

    2018-01-13

      Subclinical postural-control changes may persist beyond the point when athletes are considered clinically recovered postconcussion.   To compare postural-control performance between former high school football players with or without a history of concussion using linear and nonlinear metrics.   Case-control study.   Clinical research laboratory.   A total of 11 former high school football players (age range, 45-60 years) with 2 or more concussions and 11 age- and height-matched former high school football players without a history of concussion. No participant had college or professional football experience.   Participants completed the Sensory Organization Test. We compared postural control (linear: equilibrium scores; nonlinear: sample and multiscale entropy) between groups using a 2 × 3 analysis of variance across conditions 4 to 6 (4: eyes open, sway-referenced platform; 5: eyes closed, sway-referenced platform; 6: eyes open, sway-referenced surround and platform).   We observed a group-by-condition interaction effect for medial-lateral sample entropy ( F2,40 = 3.26, P = .049, ηp2 = 0.140). Participants with a history of concussion presented with lower medial-lateral sample entropy values (0.90 ± 0.41) for condition 5 than participants without a history of concussion (1.30 ± 0.35; mean difference = -0.40; 95% confidence interval [CI] = -0.74, -0.06; t20 = -2.48, P = .02), but conditions 4 (mean difference = -0.11; 95% CI: -0.37, 0.15; t20 = -0.86, P = .40) and 6 (mean difference = -0.25; 95% CI: -0.55, 0.06; t20 = -1.66, P = .11) did not differ between groups.   Postconcussion deficits, detected using nonlinear metrics, may persist long after injury resolution. Subclinical concussion deficits may persist for years beyond clinical concussion recovery.

  6. The neural correlates of visuo-spatial working memory in children with autism spectrum disorder: effects of cognitive load.

    Science.gov (United States)

    Vogan, Vanessa M; Morgan, Benjamin R; Lee, Wayne; Powell, Tamara L; Smith, Mary Lou; Taylor, Margot J

    2014-01-01

    Research on the neural bases of cognitive deficits in autism spectrum disorder (ASD) has shown that working memory (WM) difficulties are associated with abnormalities in the prefrontal cortex. However, cognitive load impacts these findings, and no studies have examined the relation between WM load and neural underpinnings in children with ASD. Thus, the current study determined the effects of cognitive load on WM, using a visuo-spatial WM capacity task in children with and without ASD with functional magnetic resonance imaging (fMRI). We used fMRI and a 1-back colour matching task (CMT) task with four levels of difficulty to compare the cortical activation patterns associated with WM in children (7-13 years old) with high functioning autism (N = 19) and matched controls (N = 17) across cognitive load. Performance on CMT was comparable between groups, with the exception of one difficulty level. Using linear trend analyses, the control group showed increasing activation as a function of difficulty level in frontal and parietal lobes, particularly between the highest difficulty levels, and decreasing activation as a function of difficulty level in the posterior cingulate and medial frontal gyri. In contrast, children with ASD showed increasing activation only in posterior brain regions and decreasing activation in the posterior cingulate and medial frontal gyri, as a function of difficulty level. Significant differences were found in the precuneus, dorsolateral prefrontal cortex and medial premotor cortex, where control children showed greater positive linear relations between cortical activity and task difficulty level, particularly at the highest difficulty levels, but children with ASD did not show these trends. Children with ASD showed differences in activation in the frontal and parietal lobes-both critical substrates for visuo-spatial WM. Our data suggest that children with ASD rely mainly on posterior brain regions associated with visual and lower level

  7. Real-world navigation in amnestic mild cognitive impairment: The relation to visuospatial memory and volume of hippocampal subregions.

    Science.gov (United States)

    Peter, Jessica; Sandkamp, Richard; Minkova, Lora; Schumacher, Lena V; Kaller, Christoph P; Abdulkadir, Ahmed; Klöppel, Stefan

    2017-12-10

    Spatial disorientation is a frequent symptom in Alzheimer's disease and in mild cognitive impairment (MCI). In the clinical routine, spatial orientation is less often tested with real-world navigation but rather with 2D visuoconstructive tasks. However, reports about the association between the two types of tasks are sparse. Additionally, spatial disorientation has been linked to volume of the right hippocampus but it remains unclear whether right hippocampal subregions have differential involvement in real-world navigation. Yet, this would help uncover different functional roles of the subregions, which would have important implications for understanding the neuronal underpinnings of navigation skills. We compared patients with amnestic MCI (aMCI; n = 25) and healthy elderly controls (HC; n = 25) in a real-world navigation task that engaged different spatial processes. The association between real-world navigation and different visuoconstructive tasks was tested (i.e., figures from the Consortium to Establish a Registry for Alzheimer's Disease; CERAD, the Rey-Osterrieth Complex Figure task; and clock drawing). Furthermore, the relation between spatial navigation and volume of right hippocampal subregions was examined. Linear regression and relative weight analysis were applied for statistical analyses. Patients with aMCI were significantly less able to correctly navigate through a route compared to HC but had comparable map drawing and landmark recognition skills. The association between visuoconstructive tasks and real-world navigation was only significant when using the visuospatial memory component of the Rey figure. In aMCI, more volume of the right hippocampal tail was significantly associated with better navigation skills, while volume of the right CA2/3 region was a significant predictor in HC. Standard visuoconstructive tasks (e.g., the CERAD figures or clock drawing) are not sufficient to detect real-world spatial disabilities in aMCI. Consequently, more

  8. 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.

  9. Combination of a Short Cognitive Training and tDCS to Enhance Visuospatial Skills: A Comparison Between Online and Offline Neuromodulation.

    Science.gov (United States)

    Oldrati, Viola; Colombo, Barbara; Antonietti, Alessandro

    2017-10-07

    Visuospatial skills can be enhanced thanks to specific intervention programs, but the additional benefits of neuromodulation on these skills have not been fully investigated yet, although transcranial direct current stimulation (tDCS) has demonstrated to boost the effects of cognitive trainings. When combining cognitive intervention with neuromodulation, the time-window of tDCS application in relation to task execution has to be taken into account since it has been shown to affect stimulation outcomes. The aim of the present experiment was to investigate the influence of tDCS in enhancing the effects of a training for visuospatial skills. We hypothesized that tDCS applied during training execution (online) would improve the cognitive performance at a larger extent than tDCS applied before training execution (offline). Participants received anodal tDCS over the dorsolateral prefrontal cortex during (online) or before (offline) the completion of the training. A control sham condition was included. Visuospatial abilities were measured 24 hours before (day 1, pre-test) and 24 hours after (day 3, post-test) the stimulation and training session (day 2). tDCS enhanced gains for mental folding performance when applied during the execution of the training (online). Participants' mental rotation and mental folding performance improved from pre-test to post-test regardless of the stimulation condition. However participants in the online tDCS condition showed the largest improvement in mental folding performance. Findings indicate that tDCS enhanced the effects of the training when applied during its execution, showing cumulative positive aftereffects on visuospatial performance 24 hours after the stimulation session. The time-dependent effect points out the importance of the time-window of tDCS application in influencing behavior when combined with cognitive programs. Copyright © 2017. Published by Elsevier B.V.

  10. Contribution of working memory in multiplication fact network in children may shift from verbal to visuo-spatial: a longitudinal investigation

    Science.gov (United States)

    Soltanlou, Mojtaba; Pixner, Silvia; Nuerk, Hans-Christoph

    2015-01-01

    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 (WM). 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 WM also changed with grade. Multiplication correlated with verbal WM and performance in grade 3 but with visuo-spatial WM and performance in grade 4. We suggest that the relation to verbal WM 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 WM 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. PMID:26257701

  11. Contribution of working memory in multiplication fact network in children may shift from verbal to visuo-spatial: a longitudinal investigation.

    Science.gov (United States)

    Soltanlou, Mojtaba; Pixner, Silvia; Nuerk, Hans-Christoph

    2015-01-01

    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 (WM). 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 WM also changed with grade. Multiplication correlated with verbal WM and performance in grade 3 but with visuo-spatial WM and performance in grade 4. We suggest that the relation to verbal WM 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 WM 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. 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.

  13. Effect of working memory load on electrophysiological markers of visuospatial orienting in a spatial cueing task simulating a traffic situation.

    Science.gov (United States)

    Vossen, Alexandra Y; Ross, Veerle; Jongen, Ellen M M; Ruiter, Robert A C; Smulders, Fren T Y

    2016-02-01

    Visuospatial attentional orienting has typically been studied in abstract tasks with low ecological validity. However, real-life tasks such as driving require allocation of working memory (WM) resources to several subtasks over and above orienting in a complex sensory environment. The aims of this study were twofold: firstly, to establish whether electrophysiological signatures of attentional orienting commonly observed under simplified task conditions generalize to a more naturalistic task situation with realistic-looking stimuli, and, secondly, to assess how these signatures are affected by increased WM load under such conditions. Sixteen healthy participants performed a dual task consisting of a spatial cueing paradigm and a concurrent verbal memory task that simulated aspects of an actual traffic situation. Behaviorally, we observed a load-induced detriment of sensitivity to targets. In the EEG, we replicated orienting-related alpha lateralization, the lateralized ERPs ADAN, EDAN, and LDAP, and the P1-N1 attention effect. When WM load was high (i.e., WM resources were reduced), lateralization of oscillatory activity in the lower alpha band was delayed. In the ERPs, we found that ADAN was also delayed, while EDAN was absent. Later ERP correlates were unaffected by load. Our results show that the findings in highly controlled artificial tasks can be generalized to spatial orienting in ecologically more valid tasks, and further suggest that the initiation of spatial orienting is delayed when WM demands of an unrelated secondary task are high. © 2015 Society for Psychophysiological Research.

  14. Ophthalmological outcome and visuospatial ability in very preterm children measured at 2.5 years corrected age.

    Science.gov (United States)

    Hreinsdottir, J; Ewald, U; Strand Brodd, K; Örnkloo, H; von Hofsten, C; Holmström, G

    2013-12-01

    To investigate the ophthalmological outcome of very preterm children at 2.5 years corrected age (CA) and perform a test of visuospatial and cognitive abilities. A population-based, prospective study (LOVIS study) in Uppsala County, Sweden, comprised 111 very preterm children (children (89.9%) alive at 2.5 years. Spatial cognition was investigated with a test of five alternative blocks in 48 preterm and 25 term-born children. Visual impairment, strabismus or refractive errors, were found in 12% of the children. None of the children were blind in both eyes. Logistic regression analyses revealed significant associations between strabismus and periventricular leucomalacia/intraventricular haemorrhage (OR 9.6, p = 0.025) and between refractive errors and severe retinopathy of prematurity (OR 9.8, p = 0.011) and GA (OR 0.763, p = 0.034). Oval and rectangular blocks were significantly more difficult to insert into a box for preterm than full-term children (p = 0.048 and 0.013, respectively). There was a significant correlation between total scores for the five blocks and GA at birth (p = 0.035). Eye and visual problems were found in 12% of the preterm children at 30 months CA. Preterm children had difficulties with blocks of complex shapes. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  15. Resting-State Functional Connectivity Changes Associated with Visuospatial Cognitive Deficits in Patients with Mild Alzheimer Disease.

    Science.gov (United States)

    Balachandar, Rakesh; Bharath, Srikala; John, John P; Joshi, Himanshu; Sadanand, Shilpa; Saini, Jitender; Kumar, Keshav J; Varghese, Mathew

    2017-01-01

    Alzheimer disease (AD) is a neurodegenerative disorder characterized by progressive disconnection of various brain networks leading to neuropsychological impairment. Pathology in the visual association areas has been documented in presymptomatic AD and therefore we aimed at examining the relationship between brain connectivity and visuospatial (VS) cognitive deficits in early AD. Tests for VS working memory, episodic memory and construction were used to classify patients with AD (n = 48) as having severe VS deficits (n = 12, female = 4) or mild deficits (n = 11, female = 4). Resting-state functional magnetic resonance imaging and structural images were acquired as per the standard protocols. Between-group differences in resting-state functional connectivity (rsFC) were examined by dual regression analysis correcting for age, gender, and total brain volume. Patients with AD having severe VS deficits exhibited significantly reduced rsFC in bilateral lingual gyri of the visual network compared to patients with mild VS deficits. Reduced rsFC in the visual network in patients with more severe VS deficits may be a functional neuroimaging biomarker reflecting hypoconnectivity of the brain with progressive VS deficits during early AD. © 2017 S. Karger AG, Basel.

  16. 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.

  17. Embedded performance validity tests within the Hopkins Verbal Learning Test - Revised and the Brief Visuospatial Memory Test - Revised.

    Science.gov (United States)

    Sawyer, R John; Testa, S Marc; Dux, Moira

    2017-01-01

    Various research studies and neuropsychology practice organizations have reiterated the importance of developing embedded performance validity tests (PVTs) to detect potentially invalid neurocognitive test data. This study investigated whether measures within the Hopkins Verbal Learning Test - Revised (HVLT-R) and the Brief Visuospatial Memory Test - Revised (BVMT-R) could accurately classify individuals who fail two or more PVTs during routine clinical assessment. The present sample of 109 United States military veterans (Mean age = 52.4, SD = 13.3), all consisted of clinically referred patients and received a battery of neuropsychological tests. Based on performance validity findings, veterans were assigned to valid (n = 86) or invalid (n = 23) groups. Of the 109 patients in the overall sample, 77 were administered the HLVT-R and 75 were administered the BVMT-R, which were examined for classification accuracy. The HVLT-R Recognition Discrimination Index and the BVMT-R Retention Percentage showed good to adequate discrimination with an area under the curve of .78 and .70, respectively. The HVLT-R Recognition Discrimination Index showed sensitivity of .53 with specificity of .93. The BVMT-R Retention Percentage demonstrated sensitivity of .31 with specificity of .92. When used in conjunction with other PVTs, these new embedded PVTs may be effective in the detection of invalid test data, although they are not intended for use in patients with dementia.

  18. The design organization test: further demonstration of reliability and validity as a brief measure of visuospatial ability.

    Science.gov (United States)

    Killgore, William D S; Gogel, Hannah

    2014-01-01

    Neuropsychological assessments are frequently time-consuming and fatiguing for patients. Brief screening evaluations may reduce test duration and allow more efficient use of time by permitting greater attention toward neuropsychological domains showing probable deficits. The Design Organization Test (DOT) was initially developed as a 2-min paper-and-pencil alternative for the Block Design (BD) subtest of the Wechsler scales. Although initially validated for clinical neurologic patients, we sought to further establish the reliability and validity of this test in a healthy, more diverse population. Two alternate versions of the DOT and the Wechsler Abbreviated Scale of Intelligence (WASI) were administered to 61 healthy adult participants. The DOT showed high alternate forms reliability (r = .90-.92), and the two versions yielded equivalent levels of performance. The DOT was highly correlated with BD (r = .76-.79) and was significantly correlated with all subscales of the WASI. The DOT proved useful when used in lieu of BD in the calculation of WASI IQ scores. Findings support the reliability and validity of the DOT as a measure of visuospatial ability and suggest its potential worth as an efficient estimate of intellectual functioning in situations where lengthier tests may be inappropriate or unfeasible.

  19. Comparison of Visuospatial and Verbal Abilities in First Psychotic Episode of Schizophrenia Spectrum Disorder: Impact on Global Functioning and Quality of Life.

    Science.gov (United States)

    Rodriguez, Mabel; Spaniel, Filip; Konradova, Lucie; Sedlakova, Katerina; Dvorska, Karolina; Prajsova, Jitka; Kratochvilova, Zuzana; Levcik, David; Vlcek, Kamil; Fajnerova, Iveta

    2015-01-01

    Deficit in visuospatial functions can influence both simple and complex daily life activities. Despite the fact that visuospatial deficit was reported in schizophrenia, research on visuospatial functions as an independent entity is limited. Our study aims to elucidate the impact of visuospatial deficit in comparison with verbal deficit on global functioning and quality of life in the first psychotic episode of schizophrenia spectrum disorder (FES). The significance of clinical symptoms and antipsychotic medication was also studied. Thirty-six FES patients and a matched group of healthy controls (HC group) were assessed with a neuropsychological battery focused on visuospatial (VIS) and verbal (VERB) functions. Using multiple regression analysis, we evaluated the cumulative effect of VERB and VIS functions, psychiatric symptoms (PANSS) and antipsychotic medication on global functioning (GAF) and quality of life (WHOQOL-BREF) in the FES group. The FES group demonstrated significant impairment both in VIS and VERB cognitive abilities compared to the HC group. Antipsychotic medication did not significantly affect either VIS or VERB functioning. PANSS was not related to cognitive functioning, apart from the Trail Making Test B. In the FES group, the GAF score was significantly affected by the severity of positive symptoms and VERB functioning, explaining together 60% of GAF variability. The severity of negative and positive symptoms affected only the Physical health domain of WHOQOL-BREF. The degree of VERB deficit was associated with both Physical and Psychological health. Although we did not find any relation between VIS functioning, GAF, and WHOQOL-BREF, a paradoxical finding emerged in the Environment quality domain, where a worse quality of the environment was associated with better VIS functioning. Our results suggest that the deficit in VIS functions is an integral part of cognitive deficit in schizophrenia spectrum disorders, rather than a side effect of

  20. 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.

  1. Spirit's Surroundings on 'West Spur,' Sol 305 (Vertical)

    Science.gov (United States)

    2005-01-01

    This 360-degree panorama shows the terrain surrounding NASA's Mars Exploration Rover Spirit as of the rover's 305th martian day, or sol, (Nov. 11, 2004). At that point, Spirit was climbing the 'West Spur' of the 'Columbia Hills.' The rover had just finished inspecting a rock called 'Lutefisk' and was heading uphill toward an area called 'Machu Picchu.' Spirit used its navigational camera to take the images combined into this mosaic. The rover's location when the images were taken is catalogued as the mission's site 89, position 205. The view is presented here as a vetical projection with geometric seam correction.

  2. Spirit's Surroundings on 'West Spur,' Sol 305 (Polar)

    Science.gov (United States)

    2005-01-01

    This 360-degree panorama shows the terrain surrounding NASA's Mars Exploration Rover Spirit as of the rover's 305th martian day, or sol, (Nov. 11, 2004). At that point, Spirit was climbing the 'West Spur' of the 'Columbia Hills.' The rover had just finished inspecting a rock called 'Lutefisk' and was heading uphill toward an area called 'Machu Picchu.' Spirit used its navigational camera to take the images combined into this mosaic. The rover's location when the images were taken is catalogued as the mission's site 89, position 205. The view is presented here as a polar projection with geometric seam correction.

  3. 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.

  4. Current leakage for low altitude satellites. [to surrounding plasma sheath

    Science.gov (United States)

    Mccoy, J. E.; Konradi, A.; Garriott, O. K.

    1979-01-01

    Ionospheric plasma densities exceeding 1,000,000 per cu cm exist around satellites in low earth orbit. Operation of large solar arrays at high voltage may drive substantial leakage currents through this surrounding plasma. Power losses exceeding solar cell output have been observed for small arrays biased above +2,000 V. Estimates of these effects for very large power systems are developed. Recent large scale (10 meter) lab tests are reported. Estimates based on calculations of space charge limited sheath dimensions are identified as a good working model, leading to projected power losses for large arrays increasing much more slowly than for small arrays.

  5. The science and questions surrounding chronic traumatic encephalopathy.

    Science.gov (United States)

    Ban, Vin Shen; Madden, Christopher J; Bailes, Julian E; Hunt Batjer, H; Lonser, Russell R

    2016-04-01

    Recently, the pathobiology, causes, associated factors, incidence and prevalence, and natural history of chronic traumatic encephalopathy (CTE) have been debated. Data from retrospective case series and high-profile media reports have fueled public fear and affected the medical community's understanding of the role of sports-related traumatic brain injury (TBI) in the development of CTE. There are a number of limitations posed by the current evidence that can lead to confusion within the public and scientific community. In this paper, the authors address common questions surrounding the science of CTE and propose future research directions.

  6. 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.

  7. Effectively Communicating the Uncertainties Surrounding Ebola Virus Transmission.

    Science.gov (United States)

    Kilianski, Andy; Evans, Nicholas G

    2015-10-01

    The current Ebola virus outbreak has highlighted the uncertainties surrounding many aspects of Ebola virus virology, including routes of transmission. The scientific community played a leading role during the outbreak-potentially, the largest of its kind-as many of the questions surrounding ebolaviruses have only been interrogated in the laboratory. Scientists provided an invaluable resource for clinicians, public health officials, policy makers, and the lay public in understanding the progress of Ebola virus disease and the continuing outbreak. Not all of the scientific communication, however, was accurate or effective. There were multiple instances of published articles during the height of the outbreak containing potentially misleading scientific language that spurred media overreaction and potentially jeopardized preparedness and policy decisions at critical points. Here, we use articles declaring the potential for airborne transmission of Ebola virus as a case study in the inaccurate reporting of basic science, and we provide recommendations for improving the communication about unknown aspects of disease during public health crises.

  8. Microbial communities associated with ferromanganese nodules and the surrounding sediments

    Directory of Open Access Journals (Sweden)

    Benjamin John Tully

    2013-06-01

    Full Text Available The formation and maintenance of deep-sea ferromanganese/polymetallic nodules still remains a mystery 140 years after their discovery. The wealth of rare metals concentrated in these nodules has spurred global interest in exploring the mining potential of these resources. The prevailing theory of abiotic formation has been called into question and the role of microbial metabolisms in nodule development is now an area of active research. To understand the community structure of microbes associated with nodules and their surrounding sediment, we performed targeted sequencing of the V4 hypervariable region of the 16S rRNA gene from three nodules collected from the central South Pacific. Results have shown that the microbial communities of the nodules are significantly distinct from the communities in the surrounding sediments, and that the interiors of the nodules harbor communities different from the exterior. This suggests not only differences in potential metabolisms between the nodule and sediment communities, but also differences in the dominant metabolisms of interior and exterior communities. We identified several operational taxonomic units (OTUs unique to both the nodule and sediment environments. The identified OTUs were assigned putative taxonomic identifications, including two OTUs only found associated with the nodules, which were assigned to the α-Proteobacteria. Finally, we explored the diversity of the most assigned taxonomic group, the Thaumarchaea MG-1, which revealed novel OTUs compared to previous research from the region and suggests a potential role as a source of fixed carbon for ammonia oxidizing archaea in the environment.

  9. REMOTE SENSING EFFICIENCY FOR URBAN ANALYSIS OF MECCA AND SURROUNDS

    Directory of Open Access Journals (Sweden)

    A. Imam

    2016-06-01

    Full Text Available Situated in the southwest of Saudi Arabia, Mecca is considered the spiritual capital of one and a half billion worldwide Muslims. The city is visited by millions of pilgrims every year. It has undergone significant changes in land cover (LC since the government first embarked on a series of ambitious development projects 20 years ago to accommodate the growing number of pilgrims and citizens. The main objective of our study is to detect, identify, analyze and measure the evolving land cover and urban morphology composition from multi-temporal satellite images. To characterize the morphological change during a period of twenty years, four satellite images, acquired in 1998 by Landsat TM and in 2003, 2008 and 2013 by Landsat ETM+, were classified into five main categories: Urban, Street, Soil and Vegetation. In addition, DEM has been extracted and included as Mountain. Change detection (CD analysis is applied using post-classification comparison and GIS. As part of the study, morphological index, such as, Entropy is included for better understanding of urban structures behaviour. Mecca and its surroundings show a noticeable increase in urban and vegetation cover. Urban cover (UC changes were divided into five radial directions: Northeast, Southeast, Southwest, East, and Northwest. These changes are influenced by mountain ranges surrounding the city and the highways. These revelations can play a significant role towards future planning and development activities, which may further promote urban growth.

  10. Remote Sensing Efficiency for Urban Analysis of Mecca and Surrounds

    Science.gov (United States)

    Imam, Ayman; Alhaddad, Bahaa; Roca, Josep

    2016-06-01

    Situated in the southwest of Saudi Arabia, Mecca is considered the spiritual capital of one and a half billion worldwide Muslims. The city is visited by millions of pilgrims every year. It has undergone significant changes in land cover (LC) since the government first embarked on a series of ambitious development projects 20 years ago to accommodate the growing number of pilgrims and citizens. The main objective of our study is to detect, identify, analyze and measure the evolving land cover and urban morphology composition from multi-temporal satellite images. To characterize the morphological change during a period of twenty years, four satellite images, acquired in 1998 by Landsat TM and in 2003, 2008 and 2013 by Landsat ETM+, were classified into five main categories: Urban, Street, Soil and Vegetation. In addition, DEM has been extracted and included as Mountain. Change detection (CD) analysis is applied using post-classification comparison and GIS. As part of the study, morphological index, such as, Entropy is included for better understanding of urban structures behaviour. Mecca and its surroundings show a noticeable increase in urban and vegetation cover. Urban cover (UC) changes were divided into five radial directions: Northeast, Southeast, Southwest, East, and Northwest. These changes are influenced by mountain ranges surrounding the city and the highways. These revelations can play a significant role towards future planning and development activities, which may further promote urban growth.

  11. 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.

  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. 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.

  14. Visuo-spatial working memory is an important source of domain-general vulnerability in the development of arithmetic cognition.

    Science.gov (United States)

    Ashkenazi, Sarit; Rosenberg-Lee, Miriam; Metcalfe, Arron W S; Swigart, Anna G; Menon, Vinod

    2013-09-01

    The study of developmental disorders can provide a unique window into the role of domain-general cognitive abilities and neural systems in typical and atypical development. Mathematical disabilities (MD) are characterized by marked difficulty in mathematical cognition in the presence of preserved intelligence and verbal ability. Although studies of MD have most often focused on the role of core deficits in numerical processing, domain-general cognitive abilities, in particular working memory (WM), have also been implicated. Here we identify specific WM components that are impaired in children with MD and then examine their role in arithmetic problem solving. Compared to typically developing (TD) children, the MD group demonstrated lower arithmetic performance and lower visuo-spatial working memory (VSWM) scores with preserved abilities on the phonological and central executive components of WM. Whole brain analysis revealed that, during arithmetic problem solving, left posterior parietal cortex, bilateral dorsolateral and ventrolateral prefrontal cortex, cingulate gyrus and precuneus, and fusiform gyrus responses were positively correlated with VSWM ability in TD children, but not in the MD group. Additional analyses using a priori posterior parietal cortex regions previously implicated in WM tasks, demonstrated a convergent pattern of results during arithmetic problem solving. These results suggest that MD is characterized by a common locus of arithmetic and VSWM deficits at both the cognitive and functional neuroanatomical levels. Unlike TD children, children with MD do not use VSWM resources appropriately during arithmetic problem solving. This work advances our understanding of VSWM as an important domain-general cognitive process in both typical and atypical mathematical skill development. © 2013 Elsevier Ltd. All rights reserved.

  15. Visuospatial memory improvement in patients with diffuse axonal injury (DAI): a 1-year follow-up study.

    Science.gov (United States)

    Zaninotto, Ana Luiza; Vicentini, Jessica Elias; Solla, Davi Jorge Fontoura; Silva, Tatiana Tateishi; Guirado, Vinicius Monteiro de Paula; Feltrin, Fabrício; de Lucia, Mara Cristina Souza; Teixeira, Manoel Jacobsen; Paiva, Wellingson Silva

    2017-02-01

    Diffuse axonal injury (DAI) is prevalent in traumatic brain injury (TBI), and is often associated with poor outcomes and cognitive impairment, including memory deficits. Few studies have explored visual memory after TBI and its relationship to executive functioning. Executive functioning is crucial for remembering an object's location, operating devices, driving, and route finding. We compared visual memory performance via the Rey-Osterrieth Complex Figure (ROCF) test 6 and 12 months after DAI. In total, 40 patients (mean age 28.7 years; 87.5% male) with moderate-to-severe DAI following a road traffic accident completed the 1-year follow-up. There was a three-phase prospective assessment. In phase 1 (1-3 months after trauma), patients completed the Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI). In phases 2 (6 months) and 3 (12 months), they completed the BDI, STAI, and a neuropsychological battery [ROCF copy and recall, digit span forward/backward, Grooved Pegboard test, intelligence quotient (IQ) by Wechsler Adult Intelligence Scale-III (WAIS-III)]. There was an improvement in ROCF recall over time (p=0.013), but not ROCF copy (p=0.657).There was no change in executive function (Savage scores) copy (p=0.230) or recall (p=0.155). Age, years of education, severity of the trauma, and IQ did not influence ROCF recall improvement. There are time-dependent improvements in visual memory in patients with DAI. Neuroplasticity in the 1st months after trauma provides an opportunity for visuospatial memory learning. The present findings may be useful to formulate management plans for long-term TBI rehabilitation.

  16. 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

  17. MAPPING THE SURROUNDINGS AS A REQUIREMENT FOR AUTONOMOUS DRIVING

    Directory of Open Access Journals (Sweden)

    M. Steininger

    2016-11-01

    Full Text Available Motivated by the hype around driverless cars and the challenges of the sensor integration and data processing, this paper presents a model for using a XBox One Microsoft Kinect stereo camera as sensor for mapping the surroundings. Today, the recognition of the environment of the car is mostly done by a mix of sensors like LiDAR, RADAR and cameras. In the case of the outdoor delivery challenge Robotour 2016 with model cars in scale 1:5, it is our goal to solve the task with one camera only. To this end, a three-stage approach was developed. The test results show that our approach can detect and locate objects at a range of up to eight meters in order to incorporate them as barriers in the navigation process.

  18. 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.

  19. Spirit's Surroundings on 'West Spur,' Sol 305 (3-D)

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1 [figure removed for brevity, see original site] Figure 2 This 360-degree stereo panorama shows the terrain surrounding NASA's Mars Exploration Rover Spirit as of the rover's 305th martian day, or sol, (Nov. 11, 2004). At that point, Spirit was climbing the 'West Spur' of the 'Columbia Hills.' The rover had just finished inspecting a rock called 'Lutefisk' and was heading uphill toward an area called 'Machu Picchu.' Spirit used its navigational camera to take the images combined into this mosaic. The rover's location when the images were taken is catalogued as the mission's site 89, position 205. The stereo-anaglyph view presented here is a cylindrical projection with geometric seam correction. Figure 1 is the left-eye view of a stereo pair and Figure 2 is the right-eye view of a stereo pair.

  20. A Study of the Flow Field Surrounding Interacting Line Fires

    Directory of Open Access Journals (Sweden)

    Trevor Maynard

    2016-01-01

    Full Text Available The interaction of converging fires often leads to significant changes in fire behavior, including increased flame length, angle, and intensity. In this paper, the fluid mechanics of two adjacent line fires are studied both theoretically and experimentally. A simple potential flow model is used to explain the tilting of interacting flames towards each other, which results from a momentum imbalance triggered by fire geometry. The model was validated by measuring the velocity field surrounding stationary alcohol pool fires. The flow field was seeded with high-contrast colored smoke, and the motion of smoke structures was analyzed using a cross-correlation optical flow technique. The measured velocities and flame angles are found to compare reasonably with the predicted values, and an analogy between merging fires and wind-blown flames is proposed.

  1. Progress and controversy surrounding vaccines against Lyme disease.

    Science.gov (United States)

    Hanson, Mark S; Edelman, Robert

    2003-10-01

    Less than 20 years elapsed between the 1982 report of the identification and isolation of Borrelia burgdorferi and the licensure and marketing in the USA of a prophylactic vaccine against this pathogen. However, the manufacturer removed the vaccine from the market under 4 years after its release. The low demand undoubtedly was the result of limited efficacy, need for frequent boosters, the high price of the vaccine, exclusion of children, fear of vaccine-induced musculoskeletal symptoms and litigation surrounding the vaccine. Second-generation polyvalent outer surface protein (Osp)C vaccines may overcome some of these concerns but the precise antigenic components required for efficacy are uncertain. The development of the next generation of Lyme disease vaccines is in its infancy.

  2. 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.

  3. 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.)

  4. Controversies surrounding critical illness-related corticosteroid insufficiency in animals.

    Science.gov (United States)

    Creedon, Jamie M Burkitt

    2015-01-01

    To describe the controversies surrounding critical illness-related corticosteroid insufficiency (CIRCI) and the use of hydrocortisone in critically ill patients, and to present published diagnostic and therapeutic strategies in companion veterinary species. Critical illness-related corticosteroid insufficiency may be due to hypothalamic-pituitary-adrenal (HPA) axis dysfunction, alterations in cortisol-plasma protein binding, target cell enzymatic changes, changes in glucocorticoid receptor (GR) function, or a combination of these or other factors present during critical illness. Appropriate tests to diagnose CIRCI are unknown. The diagnosis in people is currently based on response to treatment with hydrocortisone. There is currently no consensus on appropriate diagnostic feature(s) in veterinary species. Low-dose hydrocortisone is the treatment of choice for patients with CIRCI. If the patient survives the critical illness, prognosis for resolution of CIRCI and hydrocortisone dependence is very good. © Veterinary Emergency and Critical Care Society 2014.

  5. Seismic anisotropy surrounding South China Sea and its geodynamic implications

    Science.gov (United States)

    Xue, Mei; Le, Khanh Phon; Yang, Ting

    2013-12-01

    Several mechanisms have been proposed for the opening of the South China Sea. Here, we use SKS splitting analysis to investigate the mantle flow surrounding the South China Sea. We use a total of 23 seismic stations and 87 events. We applied spectral analysis and cluster analysis to find a stable splitting solution for each event. The main conclusions are: (1) In northern Vietnam, the NW-SE fast direction is parallel to the absolute plate motion as well as GPS observations with splitting times larger than 1 s, indicating a coupled lithosphere and mantle. In contrast, in southern Vietnam, the NE-SW fast direction suggests that the lithosphere and asthenosphere are decoupled. (2) The fast directions beneath the South China Block and central Taiwan are NE-SW and NS respectively, both parallel to surface deformations with splitting times greater than 1 s, indicating that mantle flow and surface deformation are related. (3) The observed NW-SE fast directions beneath Hainan Island reflect the India-Eurasia collision, and show no signatures of an upwelling mantle plume directly underneath Hainan Island. This implies that Hainan Island is tectonically closely related to the Red River Fault, not the South China Block. (4) In Borneo, the observed NE-SW direction is parallel to the Palawan Trench, consistent with flow associated with the inactive proto-South China Sea subduction system. The SKS splitting observations surrounding South China Sea cannot be explained by a single geologic process, with either the collision-driven extrusion model or the slab pull model fitting the data presented here.

  6. Quasars Probing Quasars: the Circumgalactic Medium Surrounding z ~ 2 Quasars

    Science.gov (United States)

    Lau, Marie; Quasars Probing Quasars survey

    2018-01-01

    Understanding the circumgalactic medium--the gaseous halo surrounding a galaxy, is an integral part to understanding galaxy evolution. The z ~ 2-3 universe is interesting as this is when the star formation rate and AGN activity peak. My thesis concludes the decade-long Quasars Probing Quasars survey designed for studying massive galaxy formation and quasar feedback. I use background quasar sightlines that pass close to foreground quasars to study the circumgalactic medium of quasar-host galaxies in absorption. My sample of 149 quasar pairs involve spectra taken with 17 different optical and near IR instruments. I present results on the statistical and physical properties of the circumgalactic medium. The circumgalactic medium is enriched even beyond the virial radius. The alpha/Fe abundance ratio is enhanced, suggesting enrichment from core-collapse supernovae. The cool gas mass within the virial radius is enough to fuel star formation for another Gyr, and may account for 1/3 of the baryonic budget of the galaxy halo. The ionization state increases with projected distance from the quasar, which implies the quasar does not dominate the ionizing radiation flux. However, detection of fluorescent Lyman-alpha emission and NV absorption imply these transverse absorbers are partially illuminated by the quasar. In one peculiar case, the absorbing clump has density >100 cm^-3 and sub-parsec size. The average absorption in the circumgalactic medium exhibits large velocity widths, and is asymmetric about the systemic redshift of the galaxies. The widths are consistent with gravitational motions and Hubble flow, and outflows are not required to explain them. The asymmetry can be explained if the ionizing radiation from the quasar is anisotropic or intermittent and the gas is not in inflow. My results pose challenges for cosmological hydrodynamic simulations to produce a substantial cool gas reservoir surrounding quasars, that is also enriched and shows extreme kinematics.

  7. How A Black Hole Lights Up Its Surroundings

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    How do the supermassive black holes that live at the centers of galaxies influence their environments? New observations of a distant active galaxy offer clues about this interaction.Signs of CoevolutionPlot demonstrating the m-sigma relation, the empirical correlation between the stellar velocity dispersion of a galactic bulge and the mass of the supermassive black hole at its center. [Msigma]We know that the centers of active galaxies host supermassive black holes with masses of millions to billions of suns. One mystery surrounding these beasts is that they are observed to evolve simultaneously with their host galaxies for instance, an empirical relationship is seen between the growth of a black hole and the growth of its host galaxys bulge. This suggests that there must be a feedback mechanism through which the evolution of a black hole is linked to that of its host galaxy.One proposed source of this coupling is the powerful jets emitted from the poles of these supermassive black holes. These jets are thought to be produced as some of the material accreting onto the black hole is flung out, confined by surrounding gas and magnetic fields. Because the jets of hot gas and radiation extend outward through the host galaxy, they provide a means for the black hole to influence the gas and dust of its surroundings.In our current model of a radio-loud active galactic nuclei,a region of hot, ionized gas the narrow-line region lies beyond the sphere of influence of the supermassive black hole. [C.M. Urry and P. Padovani]Clues in the Narrow-Line RegionThe region of gas thought to sit just outside of the black holes sphere of influence (at a distance of perhaps a thousand to a few thousand light-years) is known as the narrow line region so named because we observe narrow emission lines from this gas. Given its hot, ionized state, this gas must somehow be being pummeled with energy. In the canonical picture, radiation from the black hole heats the gas directly in a process

  8. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. 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.

  10. 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

  11. Fluid Production Induced Stress Analysis Surrounding an Elliptic Fracture

    Science.gov (United States)

    Pandit, Harshad Rajendra

    Hydraulic fracturing is an effective technique used in well stimulation to increase petroleum well production. A combination of multi-stage hydraulic fracturing and horizontal drilling has led to the recent boom in shale gas production which has changed the energy landscape of North America. During the fracking process, highly pressurized mixture of water and proppants (sand and chemicals) is injected into to a crack, which fractures the surrounding rock structure and proppants help in keeping the fracture open. Over a longer period, however, these fractures tend to close due to the difference between the compressive stress exerted by the reservoir on the fracture and the fluid pressure inside the fracture. During production, fluid pressure inside the fracture is reduced further which can accelerate the closure of a fracture. In this thesis, we study the stress distribution around a hydraulic fracture caused by fluid production. It is shown that fluid flow can induce a very high hoop stress near the fracture tip. As the pressure gradient increases stress concentration increases. If a fracture is very thin, the flow induced stress along the fracture decreases, but the stress concentration at the fracture tip increases and become unbounded for an infinitely thin fracture. The result from the present study can be used for studying the fracture closure problem, and ultimately this in turn can lead to the development of better proppants so that prolific well production can be sustained for a long period of time.

  12. Dead discs, unstable discs and the stars they surround

    Directory of Open Access Journals (Sweden)

    D’Angelo Caroline

    2014-01-01

    Full Text Available Strong stellar magnetic fields significantly alter the behaviour of surrounding accretion discs. Recent work has demonstrated that at low accretion rates a large amount of mass can remain confined in the disc, contrary to the standard assumption that the magnetic field will expel the disc in an outflow (the “propeller regime”. These “dead discs” often become unstable, causing cycles of accretion onto the central star. Here I present the main predictions of this model, and argue that it provides a good explanation for the peculiar behaviour seen in several accreting sources with strong magnetic fields. I will focus in particular on three accreting millisecond X-ray pulsars: SAX J1808.4-3658, NGC 6440 X-2 and IGR J00291+5934. These sources all show low-frequency quasi-periodic oscillations consistent with a variable accretion rate, as well as unusual outburst patterns that suggest gas is confined in the inner disc regions during quiescence.

  13. 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.

  14. Preliminary Analysis of Slope Stability in Kuok and Surrounding Areas

    Directory of Open Access Journals (Sweden)

    Dewandra Bagus Eka Putra

    2016-12-01

    Full Text Available The level of slope influenced by the condition of the rocks beneath the surface. On high level of slopes, amount of surface runoff and water transport energy is also enlarged. This caused by greater gravity, in line with the surface tilt from the horizontal plane. In other words, topsoil eroded more and more. When the slope becomes twice as steep, then the amount of erosion per unit area be 2.0 - 2.5 times more. Kuok and surrounding area is the road access between the West Sumatra and Riau which plays an important role economies of both provinces. The purpose of this study is to map the locations that have fairly steep slopes and potential mode of landslides. Based on SRTM data obtained,  the roads in Kuok area has a minimum elevation of + 33 m and a maximum  + 217.329 m. Rugged road conditions with slope ranging from 24.08 ° to 44.68 ° causing this area having frequent landslides. The result of slope stability analysis in a slope near the Water Power Plant Koto Panjang, indicated that mode of active failure is toppling failure or rock fall and the potential zone of failure is in the center part of the slope.

  15. Tuning structure and mobility of solvation shells surrounding tracer additives.

    Science.gov (United States)

    Carmer, James; Jain, Avni; Bollinger, Jonathan A; van Swol, Frank; Truskett, Thomas M

    2015-03-28

    Molecular dynamics simulations and a stochastic Fokker-Planck equation based approach are used to illuminate how position-dependent solvent mobility near one or more tracer particle(s) is affected when tracer-solvent interactions are rationally modified to affect corresponding solvation structure. For tracers in a dense hard-sphere fluid, we compare two types of tracer-solvent interactions: (1) a hard-sphere-like interaction, and (2) a soft repulsion extending beyond the hard core designed via statistical mechanical theory to enhance tracer mobility at infinite dilution by suppressing coordination-shell structure [Carmer et al., Soft Matter 8, 4083-4089 (2012)]. For the latter case, we show that the mobility of surrounding solvent particles is also increased by addition of the soft repulsive interaction, which helps to rationalize the mechanism underlying the tracer's enhanced diffusivity. However, if multiple tracer surfaces are in closer proximity (as at higher tracer concentrations), similar interactions that disrupt local solvation structure instead suppress the position-dependent solvent dynamics.

  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. Global structure of static spherically symmetric solutions surrounded by quintessence

    Science.gov (United States)

    Cruz, Miguel; Ganguly, Apratim; Gannouji, Radouane; Leon, Genly; Saridakis, Emmanuel N.

    2017-06-01

    We investigate all static spherically symmetric solutions in the context of general relativity surrounded by a minimally-coupled quintessence field, using dynamical system analysis. Applying the 1  +  1  +  2 formalism and introducing suitable normalized variables involving the Gaussian curvature, we were able to reformulate the field equations as first order differential equations. In the case of a massless canonical scalar field we recovered all known black hole results, such as the Fisher solution, and we found that apart from the Schwarzschild solution all other solutions are naked singularities. Additionally, we identified the symmetric phase space which corresponds to the white hole part of the solution and in the case of a phantom field, we were able to extract the conditions for the existence of wormholes and define all possible classes of solutions such as cold black holes, singular spacetimes and wormholes such as the Ellis wormhole, for example. For an exponential potential, we found that the black hole solution which is asymptotically flat is unique and it is the Schwarzschild spacetime, while all other solutions are naked singularities. Furthermore, we found solutions connecting to a white hole through a maximum radius, and not a minimum radius (throat) such as wormhole solutions, therefore violating the flare-out condition. Finally, we have found a necessary and sufficient condition on the form of the potential to have an asymptotically AdS spacetime along with a necessary condition for the existence of asymptotically flat black holes.

  18. A nebula of gases from Io surrounding Jupiter.

    Science.gov (United States)

    Krimigis, Stamatios M; Mitchell, Donald G; Hamilton, Douglas C; Dandouras, Jannis; Armstrong, Thomas P; Bolton, Scott J; Cheng, Andrew F; Gloeckler, George; Hsieh, K C; Keath, Edwin P; Krupp, Norbert; Lagg, Andreas; Lanzerotti, Louis J; Livi, Stefano; Mauk, Barry H; McEntire, Richard W; Roelof, Edmond C; Wilken, Berend; Williams, Donald J

    2002-02-28

    Several planetary missions have reported the presence of substantial numbers of energetic ions and electrons surrounding Jupiter; relativistic electrons are observable up to several astronomical units (au) from the planet. A population of energetic (>30[?]keV) neutral particles also has been reported, but the instrumentation was not able to determine the mass or charge state of the particles, which were subsequently labelled energetic neutral atoms. Although images showing the presence of the trace element sodium were obtained, the source and identity of the neutral atoms---and their overall significance relative to the loss of charged particles from Jupiter's magnetosphere---were unknown. Here we report the discovery by the Cassini spacecraft of a fast (>103[?]km[?]s-1) and hot magnetospheric neutral wind extending more than 0.5[?]au from Jupiter, and the presence of energetic neutral atoms (both hot and cold) that have been accelerated by the electric field in the solar wind. We suggest that these atoms originate in volcanic gases from Io, undergo significant evolution through various electromagnetic interactions, escape Jupiter's magnetosphere and then populate the environment around the planet. Thus a 'nebula' is created that extends outwards over hundreds of jovian radii.

  19. 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.

  20. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jürgen P.

    2012-03-01

    We present a new approach for how multiple users\\' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users\\' head positions and orientations. © 2012 IEEE.

  1. Issues surrounding lethal injection as a means of capital punishment.

    Science.gov (United States)

    Romanelli, Frank; Whisman, Tyler; Fink, Joseph L

    2008-12-01

    Lethal injection as a method of state-sanctioned capital punishment was initially proposed in the United States in 1977 and used for the first time in 1982. Most lethal injection protocols use a sequential drug combination of sodium thiopental, pancuronium bromide, and potassium chloride. Lethal injection was originally introduced as a more humane form of execution compared with existing mechanical methods such as electrocution, toxic gassing, hanging, or firing squad. Lethal injection has not, however, been without controversy. Several states are considering whether lethal injection meets constitutional scrutiny forbidding cruel and unusual punishment. Recently in the case of Ralph Baze and Thomas C. Bowling, Petitioners, v John D. Rees, Commissioner, Kentucky Department of Corrections et al, the United States Supreme Court upheld the constitutionality of the lethal injection protocol as carried out in the Commonwealth of Kentucky. Most of the debate has surrounded the dosing and procedures used in lethal injection and whether the drug combinations and measures for administering the drugs truly produce a timely, pain-free, and fail-safe death. Many have also raised issues regarding the "medicalization" of execution and the ethics of health care professionals' participation in any part of the lethal injection process. As a result of all these issues, the future of lethal injection as a means of execution in the United States is under significant scrutiny. Outcomes of ongoing legislative and judicial reviews might result in cessation of lethal injection in totality or in alterations involving specific drug combinations or administration procedures.

  2. Morphological Segregation in the Surroundings of Cosmic Voids

    Energy Technology Data Exchange (ETDEWEB)

    Ricciardelli, Elena; Tamone, Amelie [Laboratoire d’Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), 1290 Sauverny (Switzerland); Cava, Antonio [Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix (Switzerland); Varela, Jesus, E-mail: elena.ricciardelli@epfl.ch [Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan 1, E-44001 Teruel (Spain)

    2017-09-01

    We explore the morphology of galaxies living in the proximity of cosmic voids, using a sample of voids identified in the Sloan Digital Sky Survey Data Release 7. At all stellar masses, void galaxies exhibit morphologies of a later type than galaxies in a control sample, which represent galaxies in an average density environment. We interpret this trend as a pure environmental effect, independent of the mass bias, due to a slower galaxy build-up in the rarefied regions of voids. We confirm previous findings about a clear segregation in galaxy morphology, with galaxies of a later type being found at smaller void-centric distances with respect to the early-type galaxies. We also show, for the first time, that the radius of the void has an impact on the evolutionary history of the galaxies that live within it or in its surroundings. In fact, an enhanced fraction of late-type galaxies is found in the proximity of voids larger than the median void radius. Likewise, an excess of early-type galaxies is observed within or around voids of a smaller size. A significant difference in galaxy properties in voids of different sizes is observed up to 2 R {sub void}, which we define as the region of influence of voids. The significance of this difference is greater than 3 σ for all the volume-complete samples considered here. The fraction of star-forming galaxies shows the same behavior as the late-type galaxies, but no significant difference in stellar mass is observed in the proximity of voids of different sizes.

  3. Morphological Segregation in the Surroundings of Cosmic Voids

    Science.gov (United States)

    Ricciardelli, Elena; Cava, Antonio; Varela, Jesus; Tamone, Amelie

    2017-09-01

    We explore the morphology of galaxies living in the proximity of cosmic voids, using a sample of voids identified in the Sloan Digital Sky Survey Data Release 7. At all stellar masses, void galaxies exhibit morphologies of a later type than galaxies in a control sample, which represent galaxies in an average density environment. We interpret this trend as a pure environmental effect, independent of the mass bias, due to a slower galaxy build-up in the rarefied regions of voids. We confirm previous findings about a clear segregation in galaxy morphology, with galaxies of a later type being found at smaller void-centric distances with respect to the early-type galaxies. We also show, for the first time, that the radius of the void has an impact on the evolutionary history of the galaxies that live within it or in its surroundings. In fact, an enhanced fraction of late-type galaxies is found in the proximity of voids larger than the median void radius. Likewise, an excess of early-type galaxies is observed within or around voids of a smaller size. A significant difference in galaxy properties in voids of different sizes is observed up to 2 R void, which we define as the region of influence of voids. The significance of this difference is greater than 3σ for all the volume-complete samples considered here. The fraction of star-forming galaxies shows the same behavior as the late-type galaxies, but no significant difference in stellar mass is observed in the proximity of voids of different sizes.

  4. GIANT Hα NEBULA SURROUNDING THE STARBURST MERGER NGC 6240

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Michitoshi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Yagi, Masafumi; Komiyama, Yutaka; Kashikawa, Nobunari [Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Ohyama, Youichi [Institute of Astronomy and Astrophysics, Academia Sinica, 11F of Astronomy-Mathematics Building, AS/NTU No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, R.O.C. (China); Tanaka, Hisashi [Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Okamura, Sadanori, E-mail: yoshidam@hiroshima-u.ac.jp [Department of Advanced Sciences, Faculty of Science and Engineering, Hosei University, Koganei, Tokyo 184-8584 (Japan)

    2016-03-20

    We revealed the detailed structure of a vastly extended Hα-emitting nebula (“Hα nebula”) surrounding the starburst/merging galaxy NGC 6240 by deep narrow-band imaging observations with the Subaru Suprime-Cam. The extent of the nebula is ∼90 kpc in diameter and the total Hα luminosity amounts to L{sub Hα} ≈ 1.6 × 10{sup 42} erg s{sup −1}. The volume filling factor and the mass of the warm ionized gas are ∼10{sup −4}–10{sup −5} and ∼5 × 10{sup 8} M{sub ⊙}, respectively. The nebula has a complicated structure, which includes numerous filaments, loops, bubbles, and knots. We found that there is a tight spatial correlation between the Hα nebula and the extended soft-X-ray-emitting gas, both in large and small scales. The overall morphology of the nebula is dominated by filamentary structures radially extending from the center of the galaxy. A large-scale bipolar bubble extends along the minor axis of the main stellar disk. The morphology strongly suggests that the nebula was formed by intense outflows—superwinds—driven by starbursts. We also found three bright knots embedded in a looped filament of ionized gas that show head-tail morphologies in both emission-line and continuum, suggesting close interactions between the outflows and star-forming regions. Based on the morphology and surface brightness distribution of the Hα nebula, we propose the scenario that three major episodes of starburst/superwind activities, which were initiated ∼10{sup 2} Myr ago, formed the extended ionized gas nebula of NGC 6240.

  5. 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.

  6. Behavioral and electrophysiological effects of transcranial direct current stimulation (tDCS of the parietal cortex in a visuo-spatial working memory task

    Directory of Open Access Journals (Sweden)

    Kai eHeimrath

    2012-06-01

    Full Text Available Impairments of working memory (WM performance are frequent concomitant symptoms in several psychiatric and neurologic diseases. Despite the great advance in treating the reduced WM abilities in patients suffering from e.g. Parkinson’s and Alzheimer’s disease by means of tDCS, the exact neurophysiological underpinning subserving these therapeutic tDCS effects are still unknown. In the present study we investigated the impact of tDCS on performance in a visuo-spatial WM task and its underlying neural activity. In three experimental sessions, participants performed a delayed matching-to-sample WM task after sham, anodal and cathodal tDCS over the right parietal cortex. The results showed that tDCS modulated WM performance and its underlying electrophysiological brain activity in a polarity-specific way. Parietal tDCS altered event-related potentials (ERP and oscillatory power in the alpha band at posterior electrode sites.The present study demonstrates that posterior tDCS can alter visuo-spatial WM performance by modulating the underlying neural activity. This result can be considered an important step towards a better understanding of the mechanisms involved in tDCS-induced modulations of cognitive processing. This is of particular importance for the application of electrical brain stimulation as a therapeutic treatment of neuropsychiatric deficits in clinical populations.

  7. Using developmental trajectories to examine verbal and visuospatial short-term memory development in children and adolescents with Williams and Down syndromes.

    Science.gov (United States)

    Carney, Daniel P J; Henry, Lucy A; Messer, David J; Danielsson, Henrik; Brown, Janice H; Rönnberg, Jerker

    2013-10-01

    Williams (WS) and Down (DS) syndromes have been associated with specifically compromised short-term memory (STM) subsystems. Individuals with WS have shown impairments in visuospatial STM, while individuals with DS have often shown problems with the recall of verbal material. However, studies have not usually compared the development of STM skills in these domains, in these populations. The present study employed a cross-sectional developmental trajectories approach, plotting verbal and visuospatial STM performance against more general cognitive and chronological development, to investigate how the domain-specific skills of individuals with WS and DS may change as development progresses, as well as whether the difference between STM skill domains increases, in either group, as development progresses. Typically developing children, of broadly similar cognitive ability to the clinical groups, were also included. Planned between- and within-group comparisons were carried out. Individuals with WS and DS both showed the domain-specific STM weaknesses in overall performance that were expected based on the respective cognitive profiles. However, skills in both groups developed, according to general cognitive development, at similar rates to those of the TD group. In addition, no significant developmental divergence between STM domains was observed in either clinical group according to mental age or chronological age, although the general pattern of findings indicated that the influence of the latter variable across STM domains, particularly in WS, might merit further investigation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Cross-modal Association between Auditory and Visuospatial Information in Mandarin Tone Perception in Noise by Native and Non-native Perceivers

    Directory of Open Access Journals (Sweden)

    Beverly Hannah

    2017-12-01

    Full Text Available Speech perception involves multiple input modalities. Research has indicated that perceivers establish cross-modal associations between auditory and visuospatial events to aid perception. Such intermodal relations can be particularly beneficial for speech development and learning, where infants and non-native perceivers need additional resources to acquire and process new sounds. This study examines how facial articulatory cues and co-speech hand gestures mimicking pitch contours in space affect non-native Mandarin tone perception. Native English as well as Mandarin perceivers identified tones embedded in noise with either congruent or incongruent Auditory-Facial (AF and Auditory-FacialGestural (AFG inputs. Native Mandarin results showed the expected ceiling-level performance in the congruent AF and AFG conditions. In the incongruent conditions, while AF identification was primarily auditory-based, AFG identification was partially based on gestures, demonstrating the use of gestures as valid cues in tone identification. The English perceivers’ performance was poor in the congruent AF condition, but improved significantly in AFG. While the incongruent AF identification showed some reliance on facial information, incongruent AFG identification relied more on gestural than auditory-facial information. These results indicate positive effects of facial and especially gestural input on non-native tone perception, suggesting that cross-modal (visuospatial resources can be recruited to aid auditory perception when phonetic demands are high. The current findings may inform patterns of tone acquisition and development, suggesting how multi-modal speech enhancement principles may be applied to facilitate speech learning.

  9. Behavioural aspects surrounding medicine purchases from pharmacies in Australia

    Directory of Open Access Journals (Sweden)

    Emmerton L

    2008-09-01

    Full Text Available Objective: This study aimed to produce current data regarding behavioural aspects of non-prescription (over-the-counter medicine purchases, in light of changes in the pharmaceutical market and increasing provision of professional services in pharmacies.Methods: Data were collected in 15 community pharmacies in South-East Queensland, Australia, over 540 hours in five days in August, 2006. The method, previously validated, involved documentation of both observational and interview data. Fifteen trained researchers were stationed in a selected pharmacy each to unobtrusively observe all eligible sales of non-prescription medicines, and, where possible, interview the purchasers post-sale. Non-response was supplemented by observational data and recall by the salesperson. The data included details of the purchase and purchasing behaviour, while new questions addressed issues of topical importance, including customers’ privacy concerns. A selection of the analyses is reported here.Results: In total, 3470 purchases were documented (135-479 per pharmacy, with customers of 67.5% of purchases (74.7% excluding an outlier pharmacy participating in the survey. Customers averaged 1.2 non-prescription medicines per transaction. Two-thirds (67.2% of customers were female, and 38.8% of the customers were aged 31-45 years. Analgesics and respiratory medicines accounted for two-thirds of the sales data (33.4% and 32.4%, respectively. Intended-brand purchases comprised 71% of purchases (2004/2824; in-store substitution then occurred in 8.8% of these cases, mainly following recommendations by pharmacy staff. Medicines intended for self-use comprised 62.9% of purchases (1752/2785. First-time purchases (30.8%, 799/2594 were more commonly influenced by pharmacy staff than by advertising.Conclusions: This study used validated methods adapted to a changing marketplace, thus providing data that both confirm and add to knowledge surrounding medicine purchases. Despite the

  10. Circumstances surrounding dying in the paediatric intensive care unit

    Directory of Open Access Journals (Sweden)

    Plötz Frans B

    2006-08-01

    Full Text Available Abstract Background Death is inevitable in the paediatric intensive care unit (PICU. We aimed to describe the circumstances surrounding dying in a PICU. Method The chart records of all patients less than 18 years of age who died at the PICU between January first 2000 and July first 2005 were retrospectively analyzed. Information regarding sex, age, length of stay, admission, diagnosis, and the way a patient died was registered. Post mortem information regarding natural versus unnatural death, autopsy and donation was obtained. Non-survivors were allocated in five groups: do-not-resuscitate (DNR, withholding and/or withdrawal of therapy (W/W, failed cardiopulmonary resuscitation (failed CPR, brain death (BD, and terminal organ failure (TOF. Results During the study period 87 (4.4% of the 1995 admitted patients died. Non-survivors were more often admitted during the day (54% and the week (68%. W/W was found in 27.6%, TOF in 26.4%, BD in 23.0%, failed CPR in 18.4%, and DNR in 4.6%. Forty-three percent died in the first two days, of which BD (40.5% and failed CPR (37.8% were most common. Seventy-five children (86% died due to a natural cause. Autopsy permission was obtained in 19 of 54 patients (35%. The autopsies confirmed the clinical diagnosis in 11 patients, revealed new information in 5 patients, and in 3 patients the autopsy did not provide additional information. Nine patients were medically suitable for organ donation and 24 patients for tissue donation, whereas consent was only obtained in 2 cases in both groups. Conclusion We observed that 43% of the patients died within the first two days of admission due to BD and failed CPR, whereas after 4 days most patients died after W/W. Autopsy remains an useful tool to confirm clinical diagnoses or to provide new information. Only a small percentage of the deceased children is suitable for organ donation.

  11. Chandra Uncovers New Evidence For Event Horizons Surrounding Black Holes

    Science.gov (United States)

    2001-01-01

    SAN DIEGO -- Astronomers have used NASA's Chandra X-ray Observatory to study some of the darkest black holes yet observed. Their work strongly confirms the reality of the "event horizon," the one-way membrane around black holes predicted by Einstein's theory of relativity. The findings were presented today at the American Astronomical Society meeting by Drs. Michael Garcia, Jeffrey McClintock, Ramesh Narayan, and Stephen Murray of the Harvard-Smithsonian Center for Astrophysics and Dr. Paul Callanan of University College, Cork, Ireland. With results that fundamentally differ from earlier black hole studies, Garcia and his colleagues have shown that some recently discovered black holes are not only ultra-dense, but actually possess event horizons that "vacuum up" energy from their surroundings. "It is a bit odd to say we've discovered something by seeing almost nothing at all -- less than the smile of the Cheshire cat, so to speak," said Garcia, lead author on a paper submitted to the Astrophysical Journal, "but, in essence, this is what we have done." Using data from Chandra and previous X-ray satellites like ROSAT, the Chandra team studied a dozen "X-ray novas," so named because they occasionally erupt as brilliant X-ray sources then settle into decades of dormancy. The great outpouring of X rays is due to a stream of gas that is pulled from the surface of a Sun-like companion star onto a compact object, either a black hole or a neutron star. By comparing the energy output from the dormant X-ray novas, the team discovered that the sources with black holes emitted only one percent as much energy while dormant as did the X-ray novae with neutron stars. "The most straightforward explanation of these observations is that the black hole candidates we have studied have event horizons that swallow just about all of the energy that surrounds them," said Murray. "Indeed, one could even say that this work shows why black holes deserve to be called ‘black.’" "The event

  12. HUBBLE FINDS THOUSANDS OF GASEOUS FRAGMENTS SURROUNDING DYING STAR

    Science.gov (United States)

    2002-01-01

    Resembling a bizarre setting from a science fiction movie, dramatic images sent back by NASA's Hubble Space Telescope have surprised astronomers by uncovering thousands of gigantic tadpole-shaped objects surrounding a dying star. Dubbed 'cometary knots' because their glowing heads and gossamer tails superficially resemble comets, they are probably the result of a dying star's final outbursts. Though ground-based telescopic observations have hinted at such objects, they have not previously been seen in such abundance, say researchers. The knots were detected by Hubble astronomer C. Robert O'Dell and graduate student Kerry P. Handron of Rice University in Houston, Texas, while exploring the Helix nebula, a ring of glowing gases blown off the surface of a sunlike star late in its life. O'Dell expects the gaseous knots, which are each several billion miles across, will eventually dissipate and vanish into the cold emptiness of interstellar space. However, he speculates that if the objects contract to form permanent solid bodies, they may contribute to a fraction (less than ten percent) of the missing mass of our galaxy, simply because of their sheer abundance around a typical dying star. (This so-called dark matter is a known source of gravity that affects the motions of stars in the galaxy). The mysterious 'space pods' came into view as O'Dell used Hubble's Wide Field Planetary Camera 2 to survey the Helix nebula, located 450 light-years away in the constellation Aquarius and the closest planetary nebula to Earth -- so close that its angular size is almost half that of the full Moon. The most visible cometary knots all lie along the inner edge of the ring, at a distance of trillions of miles from the central star. Their comet-like tails, each stretching a hundred billion miles, form a radial pattern around the star like the spokes on a wagon wheel. Though previous ground-based observations show a spoke pattern in the Helix, and some structure, O'Dell emphasizes that

  13. 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-face identification induced

  14. 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

  15. Mapping of the Underlying Neural Mechanisms of Maintenance and Manipulation in Visuo-Spatial Working Memory Using An n-back Mental Rotation Task: A Functional Magnetic Resonance Imaging Study.

    Science.gov (United States)

    Lamp, Gemma; Alexander, Bonnie; Laycock, Robin; Crewther, David P; Crewther, Sheila G

    2016-01-01

    Mapping of the underlying neural mechanisms of visuo-spatial working memory (WM) has been shown to consistently elicit activity in right hemisphere dominant fronto-parietal networks. However to date, the bulk of neuroimaging literature has focused largely on the maintenance aspect of visuo-spatial WM, with a scarcity of research into the aspects of WM involving manipulation of information. Thus, this study aimed to compare maintenance-only with maintenance and manipulation of visuo-spatial stimuli (3D cube shapes) utilizing a 1-back task while functional magnetic resonance imaging (fMRI) scans were acquired. Sixteen healthy participants (9 women, M = 23.94 years, SD = 2.49) were required to perform the 1-back task with or without mentally rotating the shapes 90° on a vertical axis. When no rotation was required (maintenance-only condition), a right hemispheric lateralization was revealed across fronto-parietal areas. However, when the task involved maintaining and manipulating the same stimuli through 90° rotation, activation was primarily seen in the bilateral parietal lobe and left fusiform gyrus. The findings confirm that the well-established right lateralized fronto-parietal networks are likely to underlie simple maintenance of visuo-spatial stimuli. The results also suggest that the added demand of manipulation of information maintained online appears to require further neural recruitment of functionally related areas. In particular mental rotation of visuospatial stimuli required bilateral parietal areas, and the left fusiform gyrus potentially to maintain a categorical or object representation. It can be concluded that WM is a complex neural process involving the interaction of an increasingly large network.

  16. 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. © 2013 The British Psychological Society.

  17. New error type and recall consistency indices for the Brief Visuospatial Memory Test - Revised: performance in healthy adults and multiple sclerosis patients.

    Science.gov (United States)

    Gaines, Jeffrey J; Gavett, Rebecca A; Lynch, Joshua J; Bakshi, Rohit; Benedict, Ralph H B

    2008-09-01

    The Brief Visuospatial Memory Test - Revised (BVMT-R) is a reliable and well-validated test of visual-spatial memory with six equivalent, alternate forms. While the BVMT-R is commonly used in the evaluation of patients with craniocerebral trauma, schizophrenia, and multiple sclerosis (MS), the range of variables is limited. In this study, we developed new BVMT-R error and recall consistency indices. Inter-rater reliability and validity for the new indices were examined in 70 MS patients and 72 healthy volunteers. In addition to poorer general performance, MS patients made more intrusions and qualitative errors, and showed a trend toward poorer BVMT-R recall consistency. Findings suggest these error types and inconsistent learning contribute to poorer recall of visual material in MS.

  18. Study and Application on Stability Classification of Tunnel Surrounding Rock Based on Uncertainty Measure Theory

    Directory of Open Access Journals (Sweden)

    Hujun He

    2014-01-01

    Full Text Available Based on uncertainty measure theory, a stability classification and order-arranging model of surrounding rock was established. Considering the practical engineering geologic condition, 5 factors that influence surrounding rock stability were taken into account and uncertainty measure function was obtained based on the in situ data. In this model, uncertainty influence factors were analyzed quantitatively and qualitatively based on the real situation; the weight of index was given based on information entropy theory; surrounding rock stability level was judged based on credible degree recognition criterion; and surrounding rock was ordered based on order-arranging criterion. Furthermore, this model was employed to evaluate 5 sections surrounding rock in Dongshan tunnel of Huainan. The results show that uncertainty measure method is reasonable and can have significance for surrounding rock stability evaluation in the future.

  19. Effect of oral testosterone undecanoate on visuospatial cognition, mood and quality of life in elderly men with low-normal gonadal status.

    Science.gov (United States)

    Haren, Matthew T; Wittert, Gary A; Chapman, Ian M; Coates, Penelope; Morley, John E

    2005-02-14

    The effects of supplemental testosterone on cognition, mood and wellbeing in ageing men are unclear. This study aimed to assess the effect of 12-months of oral testosterone supplementation on cognitive function, mood and quality of life in elderly men with low-normal gonadal status, not specifically selected for cognitive or mood defects. A standard oral dose (80 mg twice daily) of testosterone undecanoate (TU) or placebo was administered for one year to 76 healthy men 60 years or older. All men had a free testosterone index (FTI) of 0.3-0.5, which represents a value below the normal lower limit for young men (19-30 years), but remains within the overall normal male range. A neuropsychological assessment including the trail making test (part B), visuospatial (VSP) block design test, mini mental state exam (MMSE), Geriatric Depression Scale (GDS), a 5-point Likert and a 10-point visual analogue quality of life (QoL) scale, along with serum hormone measurements were obtained at baseline, 6, and 12 months. Although calculated bioavailable testosterone (cBT) and FTI were higher, and muscle mass increased after 12 months, there was no difference in scores on the trail making or VSP block tests, the MMSE, GDS or either of the QoL scales between the testosterone and placebo group. There was no relationship between baseline cBT or FTI and treatment effect for any of the outcome measures. 12-month supplementation with oral TU does not affect scores on visuospatial tests or mood and quality of life scales in older men with low-normal gonadal status.

  20. Cognitive Impairment Assessment through Visuospatial Memory Can Be Performed with a Modified Walking Corsi Test Using the ‘Magic Carpet’

    Science.gov (United States)

    Perrochon, Anaïck; Kemoun, Gilles; Dugué, Benoit; Berthoz, Alain

    2014-01-01

    Background Subjects with mild cognitive impairment (MCI) have disturbances in their spatial navigation abilities and exhibit early deficits in visuospatial short-term memory. The purpose of the present study was to determine whether a quantitative (span score) and qualitative (evaluating navigation strategies used) analysis of the Corsi test (usual condition and complex navigation task) would be useful to reveal cognitive decline. Methods We evaluated the performance of 15 young adults, 21 healthy elderly subjects and 15 subjects with MCI using the electronic version of the Corsi test (the Modified Corsi Block-Tapping Test, MCBT) and the complex navigation task (the Modified Walking Corsi Test, MWCT). The MWCT, which is an adaptation of the Corsi test, assesses spatial memory when the subject walks in a complex environment. We used Richard et al.'s model [Cogn Sci 1993;17:497-529] to investigate problem-solving strategies during the Corsi tests. Results The span scores obtained on the MCBT and the MWCT were significantly lower in the healthy elderly subjects (MCBT = 5.0 ± 0.7; MWCT = 4.0 ± 0.7) and the subjects with MCI (MCBT = 4.7 ± 0.8; MWCT = 4.1 ± 0.9) than in the younger adults (MCBT = 6.2 ± 0.6; MWCT = 5.3 ± 1.0). The visuospatial working memory was more impaired in the complex navigation task (MWCT = 4.3 ± 0.9) than in the modified Corsi test (MCBT = 5.3 ± 0.8). Finally, the subjects with greater cognitive impairment were more likely to have inadequate or absence of problem-solving strategies. Conclusions Investigating the problem-solving strategies used during the MWCT appears to be a promising way to differentiate between the subjects with MCI and the healthy elderly subjects. PMID:24575112

  1. 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.

  2. The Effect of Integrated Hearing Protection Surround Levels on Sound Localization

    Science.gov (United States)

    2015-02-01

    Carmichael, E.L., Harris, F.P., Story, B.H.: Effects of binaural electronic hearing protectors on localization and response time to sounds in the horizontal...The effect of integrated hearing protection surround levels on sound localization Sharon M. Abel, Craig Burrell, Douglas...The effect of integrated hearing protection surround levels on sound localization Sharon M. Abel, Craig

  3. 75 FR 82407 - Submission for OMB Review; Comment Request; Testing Successful Health Communications Surrounding...

    Science.gov (United States)

    2010-12-30

    ... Successful Health Communications Surrounding Aging-Related Issues From the National Institute on Aging (NIA... number. Proposed Collection: Title: Testing successful health communications surrounding aging-related.../development of health messages and communications strategies; Pre-test health messages and outreach strategies...

  4. 3DCRT for posterior fossa: Sparing of surrounding organs at risk ...

    African Journals Online (AJOL)

    ... adequate coverage of the target volume while sparing of the cochlea and other surrounding organs at risk (OARs) at same time inevitable. Aim of the work: To compare the coverage of posterior fossa and the dose to surrounding OARs including non-posterior fossa brain, pituitary, cochlea, eyes, optic nerves, optic chiasm, ...

  5. Surround modulation characteristics of local field potential and spiking activity in primary visual cortex of cat.

    Science.gov (United States)

    Zhang, Li; Li, Bing

    2013-01-01

    In primary visual cortex, spiking activity that evoked by stimulus confined in receptive field can be modulated by surround stimulus. This center-surround interaction is hypothesized to be the basis of visual feature integration and segregation. Spiking output has been extensively reported to be surround suppressive. However, less is known about the modulation properties of the local field potential (LFP), which generally reflects synaptic inputs. We simultaneously recorded spiking activity and LFP in the area 17 of anesthetized cats to examine and compare their modulation characteristics. When the stimulus went beyond the classical receptive field, LFP exhibited decreased power along the gamma band (30-100 Hz) in most of our recording sites. Further investigation revealed that suppression of the LFP gamma mean power (gLFP) depended on the angle between the center and surround orientations. The strongest suppression was induced when center and surround orientations were parallel. Moreover, the surround influence of the gLFP exhibited an asymmetric spatial organization. These results demonstrate that the gLFP has similar but not identical surround modulation properties, as compared to the spiking activity. The spatiotemporal integration of LFP implies that the oscillation and synchronization of local synaptic inputs may have important functions in surround modulation.

  6. Different surrounding landscapes may result in different fish assemblages in East African seagrass beds

    NARCIS (Netherlands)

    Dorenbosch, M.; Grol, M.G.G.; Nagelkerken, I.; Velde, G. van der

    2006-01-01

    Few studies have considered how seagrass fish assemblages are influenced by surrounding habitats. This information is needed for a better understanding of the connectivity between tropical coastal ecosystems. To study the effects of surrounding habitats on the composition, diversity and densities of

  7. Varieties of Quest and the Religious Openness Hypothesis within Religious Fundamentalist and Biblical Foundationalist Ideological Surrounds

    Directory of Open Access Journals (Sweden)

    P. J. Watson

    2013-12-01

    Full Text Available According to the Religious Openness Hypothesis, the religious and psychological openness of American Christians is obscured by a defensive ghettoization of thought associated with a Religious Fundamentalist Ideological Surround and can be discovered instead within a Biblical Foundationalist Ideological Surround. A test of this claim examined Religious Fundamentalism, Biblical Foundationalism, Quest, and Multidimensional Quest Scales in 432 undergraduates. Christian Religious Reflection, Religious Schema, and Religious Orientation measures clarified these two ideological surrounds. Partial correlations controlling for Biblical Foundationalism described a Religious Fundamentalist Ideological Surround that more strongly rejected Quest and that more generally displayed a failure to integrate faith with intellect. Partial correlations controlling for Religious Fundamentalism revealed a Biblical Foundationalist Ideological Surround that was more open to Quest and that offered numerous demonstrations of an ability to unite faith with intellect. These data supplemented previous investigations in demonstrating that Christianity and other traditional religions have ideological resources for promoting a faithful intellect.

  8. 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

  9. [Does the islet of ability on visuospatial tasks in children with high-functioning autism really indicate a deficit in global processing?].

    Science.gov (United States)

    Planche, P; Lemonnier, E

    2011-02-01

    The literature on autism reports regularly the presence of a peak of ability on the visuospatial tasks. The classic interpretation of this result refers to the theoretical model proposed by Frith (1989) who evokes a "lack of central coherence" in persons with autism that is a deficit in the mobilization of global processing. The research reported here has for objective to propose a reflection on the relevance of this model by asking the following question: is global processing impaired in autism or simply not mobilized for the benefit of the almost exclusive appeal to local treatment? A group of children with high-functioning autism was compared with normally developping children (n=15 per group), matched on age and global level of intelligence. The clinical group, 14 boys and a girl, had received a diagnosis of typical autism according to the criteria of the ICD-10 (F84.0) confirmed by ADI-R. These children all used a functional language at the time of inclusion within the study, however all of them initially presented a delay in language (mean age: 8 years and 6 months; mean total IQ: 98.07). The typically developping group, 12 boys and three girls, were from ordinary school (mean age: 9 years, mean total IQ: 106.2). Two tasks were employed for the collection of data: the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) was used to estimate the total-, verbal- and performance-IQ scores of every child and to match both groups. It also permitted the evaluation and comparison of the performances of the children on the following visuospatial tasks: "picture completion", "object assembly" and "block design". The NEPSY scale permitted the estimation and comparison of the levels of performance of both groups on visuospatial functions. In terms of scores, the tasks of the WISC-III, requiring visiospatial processing as well as the global evaluation of the visiospatial functions with the NEPSY, showed the absence of significant differences between children

  10. Characterization of the Capsule Surrounding Smooth and Textured Tissue Expanders and Correlation with Contracture

    Directory of Open Access Journals (Sweden)

    Erika Kuriyama, MD

    2017-07-01

    Full Text Available Background:. Capsular contracture is a common complication after breast augmentation surgery. This study pathologically evaluated the soft-tissue response to surface modifications in both smooth and textured tissue expander prostheses. Methods:. Smooth tissue expanders and textured tissue expanders in 5 cases each were used for breast reconstruction after mastectomy. Histological samples were harvested from the capsules when the tissue expanders were replaced by silicone implants. Collagen orientation and cellular responses were assessed histologically. Capsular contracture was evaluated using the Baker classification 6 months and 2 years after the removal of the tissue expander. Results:. The capsules surrounding the smooth tissue expanders tended to produce more contracture than those surrounding the textured tissue expanders. The collagen architecture of the capsules of the smooth tissue expanders showed random orientation with fragmentation. Conversely, the capsules of the textured tissue expanders showed parallel orientation with collagen bundles of almost normal structure. Significantly more fibrils of elastin and myofibroblasts were found in the capsules surrounding the smooth tissue than in those surrounding the textured ones. Conclusions:. The collagen fibers surrounding the smooth tissue expanders could be cracked during expansion, which may lead to scarring and contracture. Conversely, the collagen orientation surrounding the textured tissue expanders was excellent. Moreover, the increase in elastic fibers and myofibroblasts in the capsules surrounding the smooth tissue expanders may be associated with in vivo contraction patterns. Therefore, the surface type of tissue expanders affects capsular contraction after replacement with definitive implants.

  11. Empathic surroundings

    NARCIS (Netherlands)

    Mihelj, M.; van den Broek, Egon

    2008-01-01

    In his new book (2007), Marvin Minsky states that Artificial Intelligence (AI) needs empathy to become truly smart, as is illustrated through human-human interaction. The latter also holds for Virtual Reality (VR), where the interest increases to unravel the emotional state of users has to be

  12. Effect of Insulin on Visuo-Spatial Memory and Histology of Cerebral Cortex in the Presence or Absence of Nitric Oxide Inhibition.

    Science.gov (United States)

    Yarube, I U; Ayo, J O; Fatihu, M Y; Magaji, R A; Umar, I A; Alhassan, A W; Saleh, M Ia

    2017-03-06

    Insulin has emerged from its traditional 'peripheral' glucose-lowering function to become increasingly regarded as a brain hormone that controls a wide range of functions including learning and memory. Insulin action on learning and memory is linked to nitric oxide (NO) signalling, but its effects on memory and histology of cerebral cortex in conditions of varied NO availability is unclear. This research sought to determine the effect of insulin on visuo-spatial learning, memory and histology of cerebral cortex during NO deficiency. Twenty-four mice weighing 21-23 g, were divided into four groups (n = 6) and treated daily for seven days with 0.2 ml distilled water subcutaneously (s.c.) (control), 10 I.U/kg insulin s.c., 10 I.U/kg insulin + 50 mg/kg L-NAME intraperitoneally (i.p.), and 50 mg/kg i.p. L-NAME s.c., respectively. The 3-day MWM paradigm was used to assess memory. Brain tissue was examined for histological changes. There was no significant difference between day 1 and day 2 latencies for all the groups. The mice in all (but L-NAME) groups spent more time in the target quadrant, and the difference was significant within but not between groups. There was significant reduction in number of platform site crossings (4.83 ± 0.5, 0.67 ± 0.3, 0.50 ± 0.3 and 0.50 ± 0.3 for control, insulin, insulin+L-NAME and L-NAME groups, respectively) in all the groups compared to control. Normal histology of the cortex and absence of histological lesions were observed in brain slides of control and treatment groups. It was concluded that insulin administration impairs visuo-spatial memory to a greater extent in the presence of NO block, and to a lesser extent in the absence of NO block. Nitric oxide has a role in insulin-induced memory impairment. Insulin administration in the presence or absence of NO block had no effect on histology of cortex.

  13. Two Trackers Are Better than One: Information about the Co-actor's Actions and Performance Scores Contribute to the Collective Benefit in a Joint Visuospatial Task

    Directory of Open Access Journals (Sweden)

    Basil Wahn

    2017-05-01

    Full Text Available When humans collaborate, they often distribute task demands in order to reach a higher performance compared to performing the same task alone (i.e., a collective benefit. Here, we tested to what extent receiving information about the actions of a co-actor, performance scores, or receiving both types of information impacts the collective benefit in a collaborative multiple object tracking task. In a between-subject design, pairs of individuals jointly tracked a subset of target objects among several moving distractor objects on a computer screen for a 100 trials. At the end of a trial, pairs received performance scores (Experiment 1, information about their partner's target selections (Experiment 2, or both types of information (Experiment 3. In all experiments, the performance of the pair exceeded the individual performances and the simulated performance of two independent individuals combined. Initially, when receiving both types of information (Experiment 3, pairs achieved the highest performance and divided task demands most efficiently compared to the other two experiments. Over time, performances and the ability to divide task demands for pairs receiving a single type of information converged with those receiving both, suggesting that pairs' coordination strategies become equally effective over time across experiments. However, pairs' performances never reached a theoretical limit of performance in all experiments. For distributing task demands, members of a pair predominantly used a left-right division of labor strategy (i.e., the leftmost targets were tracked by one co-actor while the rightmost targets were tracked by the other co-actor. Overall, findings of the present study suggest that receiving information about actions of a co-actor, performance scores, or receiving both enables pairs to devise effective division of labor strategies in a collaborative visuospatial task. However, when pairs had both types of information available, the

  14. The effects of task-relevant saccadic eye movements performed during the encoding of a serial sequence on visuospatial memory performance.

    Science.gov (United States)

    Martin, Leonardo; Tapper, Anthony; Gonzalez, David A; Leclerc, Michelle; Niechwiej-Szwedo, Ewa

    2017-05-01

    Visuospatial working memory (VSWM) is a set of cognitive processes used to encode, maintain and manipulate spatial information. One important feature of VSWM is that it has a limited capacity such that only few items can be actively stored and manipulated simultaneously. Given the limited capacity, it is important to determine the conditions that affect memory performance as this will improve our understanding of the architecture and function of VSWM. Previous studies have shown that VSWM is disrupted when task-irrelevant eye movements are performed during the maintenance phase; however, relatively fewer studies examined the role of eye movements performed during the encoding phase. On one hand, performing eye movements during the encoding phase could result in a stronger memory trace because the memory formation is reinforced by the activation of the motor system. On the other hand, performing eye movements to each target could disrupt the configural processing of the spatial array because the spatial representation has to be updated with each movement to maintain perceptual stability. Therefore, this work was conducted to examine whether task-relevant saccadic eye movements performed during the encoding phase of a visuospatial working memory task affect the recall of serially presented targets. Results from two experiments showed that average recall accuracy was significantly higher when the spatial array (set size ≥ 7) was encoded using a covert strategy-that is, while participants fixated on a central target, in comparison to an overt strategy-that is, while participants moved their eyes to fixate on each target. Furthermore, the improvement in accuracy was evident only for targets presented in the first half of the sequence, suggesting that the primacy effect is modulated by the presence of eye movements. We propose that executing saccades during encoding could interfere with the ability to use a chunking strategy or disrupt active visualization of the

  15. Automobile Optimal Driving Control Using Surrounding Information Based on Model Predictive Control

    Science.gov (United States)

    Wu, Dongmei; Xia, Yang; Ogawa, Masatoshi; Ogai, Harutoshi; Kawabe, Taketoshi

    In this paper, an optimal driving control system based on model predictive control (MPC) is developed for the purpose of processing more surrounding information which is essential for improving the current intelligent driving assistance and further dealing with traffic issues caused by automobiles. The proposed system provides a method of calculating a desirable driving path based on surrounding traffic environments. The performance of this system is evaluated through simulations which are carried out with introduction of surrounding information such as traffic jams, traffic signal changes, and fuel consumption. Simulation results reveal that the proposed system as a driving assist system has a potential of finding optimal driving paths for drivers.

  16. Surround inhibition of mammalian AII amacrine cells is generated in the proximal retina.

    Science.gov (United States)

    Bloomfield, S A; Xin, D

    2000-03-15

    1. Intracellular recordings were obtained from neurons in the superfused retina-eyecup preparation of the rabbit under dark-adapted conditions. Neurotransmitter agonists and antagonists were applied exogenously via the superfusate to dissect the synaptic pathways pharmacologically and thereby determine those pathways responsible for the generation of the on-centre/off-surround receptive fields of AII amacrine cells. 2. Application of the metabotropic glutamate receptor agonist, APB, reversibly blocked both the on-centre and off-surround responses of AII cells. These data were consistent with the idea that both the centre- and surround-mediated responses are derived from inputs from the presynaptic rod bipolar cells. 3. Whereas rod bipolar cells showed on-receptive fields approximately 100 microm across, we found no evidence for an antagonistic off-surround response using light stimuli which effectively elicited the off-surrounds of AII amacrine cells. These results indicated that the surrounds of AII cells are not derived from rod bipolar cell inputs. 4. Application of the ionotropic glutamate receptor antagonists CNQX or DNQX enhanced the on-centre responses of AII cells but attenuated the off-surround responses. These data indicated that the centre- and surround-mediated responses could not both be derived from signals crossing the rod bipolar-to-AII cell synapse. 5. Application of the glycine antagonist, strychnine, had only minor and variable effects on AII cell responses. However, the GABA antagonists picrotoxin and bicuculline enhanced the on-centre response but attenuated or completely blocked the off-surround response of AII cells. The GABA antagonists had no effect on the responses of horizontal cells indicating that their effects on AII cell responses reflected actions on inner retinal circuitry rather than feedback circuitry in the outer plexiform layer. 6. Application of the voltage-gated sodium channel blocker TTX enhanced the on-centre responses of

  17. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  18. Hurricane Dennis Aerial Photography: Draft Image Mosaics of the Florida Panhandle and Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the Florida panhandle and surrounding regions after Hurricane Dennis made landfall. The regions photographed range from...

  19. The relation between residential property and its surroundings and day- and night-time residential burglary

    NARCIS (Netherlands)

    Montoya, Lorena; Junger, Marianne; Ongena, Yfke

    This article examines how residential property and its surroundings influence day- and night-time residential burglary. Crime Prevention Through Environmental Design (CPTED) principles of territoriality, surveillance, access control, target hardening, image maintenance, and activity support underpin

  20. Tropical Storm Ernesto Aerial Photography: Rapid Response Imagery of the Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the surrounding regions after Tropical Storm Ernesto made landfall. The aerial photography missions were conducted by the NOAA...

  1. A deformation mechanism of hard metal surrounded by soft metal during roll forming

    National Research Council Canada - National Science Library

    Yu, Hailiang; Tieu, A Kiet; Lu, Cheng; Liu, Xiong; Godbole, Ajit; Li, Huijun; Kong, Charlie; Qin, Qinghua

    2014-01-01

    .... The experimental results lead us to propose a new deformation mechanism for a hard metal surrounded by a soft metal during rolling of a laminated foil, particularly when the thickness of hard metal foil (Ti, 25 μm...

  2. Weakened Center-Surround Interactions in Visual Motion Processing in Schizophrenia

    National Research Council Canada - National Science Library

    Tadin, Duje; Kim, Jejoong; Doop, Mikisha L; Gibson, Crystal; Lappin, Joseph S; Blake, Randolph; Park, Sohee

    2006-01-01

    .... Center-surround suppression has been implicated in a range of visual functions, including figure-ground segregation and pursuit eye movements, visual functions that are impaired in schizophrenia...

  3. Hurricane Ike Aerial Photography: Rapid ResponseImagery of the Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the surrounding regionsafter Hurricane Ike made landfall. The aerial photography missions wereconducted by the NOAA Remote...

  4. Modelling of the effect of discontinuities on the extent of the fracture zone surrounding deep tunnels

    CSIR Research Space (South Africa)

    Sellers, EJ

    2000-10-01

    Full Text Available A series of physical and numerical model tests were performed to investigate the behaviour of the rock surrounding circular excavations under high confining pressures. The aim was to provide information on the formation of fractures around deep...

  5. Particulate capture efficiency of a vegetative environmental buffer surrounding an animal feeding operation

    Science.gov (United States)

    Particulate matter emitted from tunnel-ventilated animal feeding operations (AFOs) is known to transport malodorous compounds. As a mitigation strategy, vegetative environmental buffers (VEBs) are often installed surrounding AFOs to capture particulates and induce lofting and dispersion. Currently, ...

  6. Reduced visual surround suppression in schizophrenia shown by measuring contrast detection thresholds

    Science.gov (United States)

    Serrano-Pedraza, Ignacio; Romero-Ferreiro, Verónica; Read, Jenny C. A.; Diéguez-Risco, Teresa; Bagney, Alexandra; Caballero-González, Montserrat; Rodríguez-Torresano, Javier; Rodriguez-Jimenez, Roberto

    2014-01-01

    Visual perception in schizophrenia is attracting a broad interest given the deep knowledge that we have about the visual system in healthy populations. One example is the class of effects known collectively as visual surround suppression. For example, the visibility of a grating located in the visual periphery is impaired by the presence of a surrounding grating of the same spatial frequency and orientation. Previous studies have suggested abnormal visual surround suppression in patients with schizophrenia. Given that schizophrenia patients have cortical alterations including hypofunction of NMDA receptors and reduced concentration of GABA neurotransmitter, which affect lateral inhibitory connections, then they should be relatively better than controls at detecting visual stimuli that are usually suppressed. We tested this hypothesis by measuring contrast detection thresholds using a new stimulus configuration. We tested two groups: 21 schizophrenia patients and 24 healthy subjects. Thresholds were obtained using Bayesian staircases in a four-alternative forced-choice detection task where the target was a grating within a 3∘ Butterworth window that appeared in one of four possible positions at 5∘ eccentricity. We compared three conditions, (a) target with no-surround, (b) target embedded within a surrounding grating of 20∘ diameter and 25% contrast with same spatial frequency and orthogonal orientation, and (c) target embedded within a surrounding grating with parallel (same) orientation. Previous results with healthy populations have shown that contrast thresholds are lower for orthogonal and no-surround (NS) conditions than for parallel surround (PS). The log-ratios between parallel and NS thresholds are used as an index quantifying visual surround suppression. Patients performed poorly compared to controls in the NS and orthogonal-surround conditions. However, they performed as well as controls when the surround was parallel, resulting in significantly

  7. P1-13: Color Induction from Surround Color under Interocular Suppression

    Directory of Open Access Journals (Sweden)

    Ichiro Kuriki

    2012-10-01

    Full Text Available The effect of surround colors on color appearance is known to subserve color constancy in humans, but how multiple mechanisms in the visual system are involved in this effect is controversial. We used an interocular-suppression technique to examine how the effect occurs at the level higher than the interaction of binocular information. A test color chip (1.7 × 1.7 deg visual angle was presented in a static surround either with continuous-flash suppression in the dominant eye (CFS condition to make the surround inperceptible or without the suppression (no-CFS condition. The surround stimulus was either a Mondrian or a uniform field of the same mean chromaticity. Stimuli were simulated OSA color chips under red, white (D65, or green illuminant color and were presented on a CRT display. Unique yellows were measured by asking the subjects to judge whether the test stimulus appeared reddish or greenish. Two sizes of the surround stimuli (widths of 1 deg and 4 deg were used. Results showed significant shifts in unique yellow even under the CFS conditions, except for the 1 deg uniform-surround condition. Under the no-CFS condition, the shifts showed remarkable difference between subjects, except for the 4 deg Mondrian-surround condition. Interestingly, trends of the shifts showed high consistency within each subject, across conditions. These results indicate that mechanisms at both higher and lower levels than the neuronal site of interocular suppression are involved, and that the color shifts follow each subject's strategy in the higher-order mechanisms when only insufficient clues are available in the surround to estimate illuminant color.

  8. Delayed maturation of receptive field center/surround mechanisms in V2

    OpenAIRE

    Zhang, Bin; Zheng, Jianghe; Watanabe, Ichiro; Maruko, Ichiro; Bi, Hua; Smith, Earl L.; Chino, Yuzo

    2005-01-01

    Neurons in the adult visual cortex are capable of integrating signals over a large area that surrounds their classic receptive field (RF), and this ability of cortical neurons is thought to be intimately involved in perceptual binding. It is not known, however, at what age these long-range signal interactions emerge. Here, we report that qualitatively adult-like center/surround interactions are already present in the primary visual cortex as early as postnatal day 14 in macaque monkeys. Howev...

  9. High-intensity stress elicits robust cortisol increases, and impairs working memory and visuo-spatial declarative memory in Special Forces candidates: A field experiment.

    Science.gov (United States)

    Taverniers, John; Van Ruysseveldt, Joris; Smeets, Tom; von Grumbkow, Jasper

    2010-07-01

    While running a selection procedure, 27 male Belgian Special Forces candidates, with a mean age of 27.4 years (SD = 5.1), were randomly assigned to a no-stress control (n = 14) or a high-intensity stress group (n = 13). Participants in the latter group were exposed to an extremely strenuous mock prisoner of war (POW) exercise. Immediately after stress or control treatment, working memory and visuo-spatial declarative memory performances were measured by the digit span (DS) test and the Rey-Osterrieth complex figure (ROCF), respectively. Concurrently, stress levels were assessed by obtaining salivary cortisol measurements and subjectively by the NASA Task Load Index (TLX). As expected, exposure to high-intensity stress led to both robust cortisol increases and significant differences in TLX scores. Stress induction also significantly impaired DS and ROCF performances. Moreover, delta cortisol increases and ROCF performance in the POW stress group showed a significant negative correlation, while DS performances followed the same tendency. Summarizing, the current findings complement and extend previous work on hormonal stress effects, and the subsequent performance deterioration on two memory tests in a unique high-intensity stress environment.

  10. Hyperactivity in boys with attention-deficit/hyperactivity disorder: The influence of underlying visuospatial working memory and self-control processes.

    Science.gov (United States)

    Patros, Connor H G; Alderson, R Matt; Hudec, Kristen L; Tarle, Stephanie J; Lea, Sarah E

    2017-02-01

    Changes in motor activity were examined across control and executive function (EF) tasks that differ with regard to demands placed on visuospatial working memory (VS-WM) and self-control processes. Motor activity was measured via actigraphy in 8- to 12-year-old boys with (n=15) and without (n=17) attention-deficit/hyperactivity disorder (ADHD) during the completion of VS-WM, self-control, and control tasks. Results indicated that boys with ADHD, relative to typically developing boys, exhibited greater motor activity across tasks, and both groups' activity was greater during EF tasks relative to control tasks. Lastly, VS-WM performance, relative to self-control performance, accounted for significantly more variance in activity across both VS-WM and self-control tasks. Collectively, findings suggest that ADHD-related hyperactivity is positively related to increased cognitive demands and appears to be better explained by deficient VS-WM rather than insufficient self-control. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Demographically corrected normative data for the Hopkins Verbal Learning Test-Revised and Brief Visuospatial Memory Test-Revised in an elderly sample.

    Science.gov (United States)

    Duff, Kevin

    2016-01-01

    Demographic variables, such as age, education, and gender, routinely affect performance on neuropsychological tests. Whereas normative data are available to correct for these variables on many tests, data are lacking on the Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R), especially in the elderly. The current study examined the influence of age, education, and gender on HVLT-R and BVMT-R scores in 290 cognitively intact older adults. Age negatively correlated with nearly every score on the HVLT-R and BVMT-R, and education positively correlated with most scores on these same 2 memory tests. There were fewer gender differences on these tests. Using stepwise multiple regression, HVLT-R and BVMT-R scores were predicted from age, education, and/or gender. When observed scores are compared to these demographically adjusted predicted scores, clinicians can make assumptions about how an individual compared to his/her age-, education-, and gender-matched peers. The current conorming of these 2 memory tests also allows for direct comparison between verbal and visual memory in older patients.

  12. Study on the Optimal Equivalent Radius in Calculating the Heat Dissipation of Surrounding Rock

    Directory of Open Access Journals (Sweden)

    H. T. Song

    2015-11-01

    Full Text Available The heat dissipation of surrounding rock of a non-circular roadway is computed using an equivalent circular roadway approach under three circumstances when the area, perimeter, or hydraulic diameter of the circular roadway is equal to the non-circular roadway to obtain the optimal equivalent radius. The differential equations of heat conduction for unstable surrounding rock are established in cylindrical and rectangular coordinate systems using dimensionless analysis method. The calculation formulas of heat dissipation capacity and heat transfer resistance are derived from differential equations. Based on the method of equivalent radius, the similarities and differences between non-circular and circular roadways in calculating the heat dissipation of surrounding rock are discussed. Using the finite volume method, the calculation models for non-circular and circular roadways in the heat dissipation of surrounding rock are also established, among the non-circular roadways including three circumstances, namely, trapezoid, rectangle, and arch. The relation errors of heat dissipation of the surrounding rock of the three equivalent circular roadway methods are investigated for the three non-circular roadways. Results show that the calculation approach with equal perimeters is the best for the heat dissipation of surrounding rock of non-circular roadways.

  13. Response Suppression in V1 Agrees with Psychophysics of Surround Masking

    Science.gov (United States)

    Zenger-Landolt, Barbara; Heeger, David J.

    2008-01-01

    When a target stimulus is embedded in a high contrast surround, the target appears reduced in contrast and is harder to detect, and neural responses in visual cortex are suppressed. We used functional magnetic resonance imaging (fMRI) and psychophysics to quantitatively compare these physiological and perceptual effects. Observers performed a contrast discrimination task on a contrast-reversing sinusoidal target grating. The target was either presented in isolation or embedded in a high-contrast surround. While observers performed the task, we also measured fMRI responses as a function of target contrast, both with and without a surround. We found that the surround substantially increased the psychophysical thresholds while reducing fMRI responses. The two data sets were compared, on the basis of the assumption that a fixed response difference is required for correct discrimination, and we found that the psychophysics accounted for 96.5% of the variance in the measured V1 responses. The suppression in visual areas V2 and V3 was stronger, too strong to agree with psychophysics. The good quantitative agreement between psychophysical thresholds and V1 responses suggests V1 as a plausible candidate for mediating surround masking. PMID:12890783

  14. Delayed maturation of receptive field center/surround mechanisms in V2.

    Science.gov (United States)

    Zhang, Bin; Zheng, Jianghe; Watanabe, Ichiro; Maruko, Ichiro; Bi, Hua; Smith, Earl L; Chino, Yuzo

    2005-04-19

    Neurons in the adult visual cortex are capable of integrating signals over a large area that surrounds their classic receptive field (RF), and this ability of cortical neurons is thought to be intimately involved in perceptual binding. It is not known, however, at what age these long-range signal interactions emerge. Here, we report that qualitatively adult-like center/surround interactions are already present in the primary visual cortex as early as postnatal day 14 in macaque monkeys. However, the RF surrounds of visual area 2 (V2) neurons were largely absent until 4 weeks of age and, as late as 8 weeks of age, center/surround signal interactions in V2 neurons were immature. Our results suggest that the cortical circuits underlying the RF center/surround of individual neurons mature considerably later in V2 than in the primary visual cortex and give critical evidence for the hypothesis that the functional maturation of the primate visual brain proceeds in a hierarchical manner.

  15. Effects of Surrounding Information and Line Length on Text Comprehension from the Web

    Directory of Open Access Journals (Sweden)

    Jess McMullin

    2002-02-01

    Full Text Available The World Wide Web (Web is becoming a popular medium for transmission of information and online learning. We need to understand how people comprehend information from the Web to design Web sites that maximize the acquisition of information. We examined two features of Web page design that are easily modified by developers, namely line length and the amount of surrounding information, or whitespace. Undergraduate university student participants read text and answered comprehension questions on the Web. Comprehension was affected by whitespace; participants had better comprehension for information surrounded by whitespace than for information surrounded by meaningless information. Participants were not affected by line length. These findings demonstrate that reading from the Web is not the same as reading print and have implications for instructional Web design.

  16. Research of strain distribution and strain rate change in the fracture surroundings by the videoextensometric methode

    Directory of Open Access Journals (Sweden)

    M. Mihaliková

    2010-07-01

    Full Text Available The paper deals with the strain distribution and the strain rate of material in the surroundings of its fracture. Three steels applied in the automotive industry (DP - dual phase steel, microalloyed steel HR 45 and IF - interstitial free steel were used as the experimental material. The videoextensometric technique was used for sensing with CCD camera and computer. During the test, software records the coordinates of the centres of gravity of individual points, from which the respective strain values are then obtained. For individual steel grades, strain field maps in the fracture surroundings were plotted. The change in the strain rate in the fracture surroundings and at places more distant from the fracture was observed.

  17. The particulate environment surrounding the space station: Estimates from the PACS data

    Science.gov (United States)

    Green, Byron David

    1988-01-01

    The objectives of the Particle Analysis Cameras for Shuttle (PACS) experiment (flown on STS-61C) are described and the experiment results are discussed in reference to the expected Space Station environment. Estimates of the sources of particulates surrounding the Space Station were made based on the existing orbital observations data base. Particulates surrounding the shuttle are mostly event related or from the residual release of mass (dust) brought to orbit from the ground. The particulates surrounding the Space Station are likely to arise from additional sources such as operations, docking, erosion, and abrasion. Thus, scaling of the existing data base to long-duration missions in low-Earth orbit requires analysis, modeling, and simulation testing.

  18. Association of physical activity with the visuospatial/executive functions of the montreal cognitive assessment in patients with vascular cognitive impairment.

    Science.gov (United States)

    Ihara, Masafumi; Okamoto, Yoko; Hase, Yoshiki; Takahashi, Ryosuke

    2013-10-01

    The Montreal Cognitive Assessment (MoCA) is more suitable than the Mini-Mental State Examination (MMSE) for the detection of vascular cognitive impairment. In this study, we performed a correlation analysis of MoCA/MMSE scores with daily physical activity in patients with subcortical ischemic white matter changes. Ten patients (average 75.9 ± 9.1 years old) with extensive leukoaraiosis detected on magnetic resonance imaging underwent cognitive testing, including the MMSE and the Japanese version of the MoCA (MoCA-J). Physical activity was monitored with the Kenz Lifecorder EX device (Suzuken, Nagoya, Japan) to assess daily physical activity in terms of caloric expenditure, motor activity, number of steps, and walking distance for 6 months. Correlations of individual physical activity with total and subscale scores of MMSE/MoCA-J or 6-month interval change of MoCA-J scores were assessed. The total or subscale scores of the MMSE did not correlate with any parameters of physical activity. However, the mean number of steps and walking distance significantly correlated with the total MoCA-J scores (r = .67 and .64, respectively) and its visuospatial/executive subscores (r = .66 and .66, respectively). The mean interval change of MoCA-J was + .6; those who improved number of steps (n = 4; 80.5 ± 3.0 years of age) had significantly preserved MoCA-J scores compared to those who did not (n = 6; 73.0 ± 11.6 years of age; +2.0 versus - .3; P = .016). These results suggest that MoCA is useful to detect a biologically determined specific relationship between physical activity and executive function. In addition, physical exercise, such as walking, may help enhance cognitive function in patients with vascular cognitive impairment of subcortical origin. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  19. Lack of Associations between Female Hormone Levels and Visuospatial Working Memory, Divided Attention and Cognitive Bias across Two Consecutive Menstrual Cycles

    Directory of Open Access Journals (Sweden)

    Brigitte Leeners

    2017-07-01

    Full Text Available Background: Interpretation of observational studies on associations between prefrontal cognitive functioning and hormone levels across the female menstrual cycle is complicated due to small sample sizes and poor replicability.Methods: This observational multisite study comprised data of n = 88 menstruating women from Hannover, Germany, and Zurich, Switzerland, assessed during a first cycle and n = 68 re-assessed during a second cycle to rule out practice effects and false-positive chance findings. We assessed visuospatial working memory, attention, cognitive bias and hormone levels at four consecutive time-points across both cycles. In addition to inter-individual differences we examined intra-individual change over time (i.e., within-subject effects.Results: Estrogen, progesterone and testosterone did not relate to inter-individual differences in cognitive functioning. There was a significant negative association between intra-individual change in progesterone and change in working memory from pre-ovulatory to mid-luteal phase during the first cycle, but that association did not replicate in the second cycle. Intra-individual change in testosterone related negatively to change in cognitive bias from menstrual to pre-ovulatory as well as from pre-ovulatory to mid-luteal phase in the first cycle, but these associations did not replicate in the second cycle.Conclusions: There is no consistent association between women's hormone levels, in particular estrogen and progesterone, and attention, working memory and cognitive bias. That is, anecdotal findings observed during the first cycle did not replicate in the second cycle, suggesting that these are false-positives attributable to random variation and systematic biases such as practice effects. Due to methodological limitations, positive findings in the published literature must be interpreted with reservation.

  20. 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.

  1. Stratigraphy and tectonics of Permo-Triassic basins in the Netherlands and surrounding areas

    NARCIS (Netherlands)

    Geluk, M.C.

    2005-01-01

    This thesis addresses different aspects of the geological development during the Permian and Triassic (300 to 200 Ma) of the Netherlands and surrounding areas. The study area encompasses the Southern Permian Basin (SPB), a large intracratonic basin stretched out from the United Kingdom in the west

  2. Music mixes for comparison of wave field synthesis, surround, and stereo

    OpenAIRE

    Hold, Christoph; Wierstorf, Hagen

    2016-01-01

    Four different music mixes are provided in the form of loudspeaker driving signals. Each mix was produced for wave field synthesis, surround, and stereo by the same mixing engineer. This allows a direct comparison of the different reproduction methods in listening tests.

  3. Do personal conditions and circumstances surrounding partner loss explain loneliness in newly bereaved older adults?

    NARCIS (Netherlands)

    van Baarsen, B.; Smit, J.H.; Snijders, T.A.B.; Knipscheer, C.P.M.

    1999-01-01

    This longitudinal study aims to explain loneliness in newly bereaved older adults, taking into account personal and circumstantial conditions surrounding the partner's death. A distinction is made between emotional and social loneliness. Data were gathered both before and after partner loss. Results

  4. Numerical bifurcation analysis of distance-dependent on-center off-surround shunting neural networks.

    NARCIS (Netherlands)

    Molenaar, P.C.M.; Raijmakers, M.E.J.; van der Maas, H.L.J.

    1996-01-01

    On-center off-surround shunting neural networks are often applied as models for content-addressable memory (CAM), the equilibria being the stored memories. One important demand of biological plausible CAMs is that they function under a broad range of parameters, since several parameters vary due to

  5. Do personal conditions and circumstances surrounding partner loss explain loneliness in newly bereaved older adults?

    NARCIS (Netherlands)

    van Baarsen, B.; Smit, J.H; Snijders, T.A.B.; Knipscheer, K.P.M.

    This longitudinal study aims to explain loneliness in newly bereaved older adults, taking into account personal and circumstantial conditions surrounding the partner's death. A distinction is made between emotional and social loneliness. Data were gathered both before and after partner loss. Results

  6. Homogamy and Intermarriage of Japanese and Japanese Americans with Whites Surrounding World War II

    Science.gov (United States)

    Ono, Hiromi; Berg, Justin

    2010-01-01

    Although some sociologists have suggested that Japanese Americans quickly assimilated into mainstream America, scholars of Japanese America have highlighted the heightened exclusion that the group experienced. This study tracked historical shifts in the exclusion level of Japanese and Japanese Americans in the United States surrounding World War…

  7. Socio-economic impact of ox skidding project to the surrounding ...

    African Journals Online (AJOL)

    Results indicate that the ox skidding project has been a reliable and valuable source of income besides offering employment to young people with only limited ... in this area is likely to continue since farmers surrounding these plantations keep cattle and there are not many alternative job opportunities for the young people.

  8. Thermal and mechanical stability of retained austenite surrounded by martensite with different degrees of tempering

    NARCIS (Netherlands)

    Hidalgo Garcia, J.; Findley, K.O.; Santofimia Navarro, M.J.

    2017-01-01

    The mechanical and thermal stability of austenite in multiphase advanced high strength steels are influenced by the surrounding microstructure. The mechanisms underlying and the relations between thermal and mechanical stability are still dubious due to the difficulty of isolating other factors

  9. Can Centre Surround Model Explain the Enhancement of Visual Perception through Stochastic Resonance?

    CERN Document Server

    Kundu, Ajanta

    2010-01-01

    We demonstrate the ability of centre surround model for simulating the enhancement of contrast sensitivity through stochastic resonance observed in psychophysical experiments. We also show that this model could be used to simulate the contrast sensitivity function through stochastic resonance. The quality of the fit of measured contrast sensitivity function to the simulated data is very good.

  10. Evaluating the effect of the space surrounding the condenser of a household refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Bassiouny, Ramadan [Dept. of Mech. Power Eng. and Energy, Faculty of Engineering, Minia University, Minia 61111 (Egypt)

    2009-11-15

    The paper presents an analytical and computational modeling of the effect of the space surrounding the condenser of a household refrigerator on the rejected heat. The driving force for rejecting the heat carried by the refrigerant from the interior of a refrigerator is the temperature difference between the condenser outer surface and surrounding air. The variation of this difference, because of having an insufficient space, increasing the room air temperature, or blocking this space, is of interest to quantify its effect The results showed that having an enough surrounding space width (s > 200 mm) leads to a decrease in the temperature of the air flowing vertically around the condenser coil. Accordingly, this would significantly increase the amount of heat rejected. Moreover, blocking this space retards the buoyant flow up the condenser surface, and hence increases the air temperature around the condenser. This would also decrease the heat rejected from the condenser. Predicted temperature contours are displayed to visualize the air plumes' variation surrounding the condenser in all cases. (author)

  11. Evaluation of the impact of mine activity on surrounding soils of Draa ...

    African Journals Online (AJOL)

    Evaluation of the impact of mine activity on surrounding soils of Draa Lasfar mine in Marrakech- Morocco. ... African Journal of Environmental Science and Technology ... The aim of the present study was to evaluate the spatial distribution of heavy metals in Draa Lasfar mine area in Marrakech city and understand the ...

  12. The collective action on governing the commons in the surroundings of protected areas

    NARCIS (Netherlands)

    Araújo Pereira, de Márcio; Schneider, Sérgio; Ploeg, van der Jandouwe; Souza, de Marcelino

    2016-01-01

    This work has as its theme the common natural resources and the management models that allow new governance systems in the rural areas in the surrounding of protected areas. In this sense, this paper aims to discuss the collective action of social actors in the management of common natural

  13. Perils to pregnancies: On social sorrows and strategies surrounding pregnancy loss in Cameroon

    NARCIS (Netherlands)

    Sijpt, E. van der; Notermans, C.D.

    2010-01-01

    This article explores the local perceptions and practices surrounding pregnancy loss in Cameroon-a topic that has long been neglected in international reproductive health debates. Based on extended periods of anthropological fieldwork in an urban and a rural setting in the East province of the

  14. Greenhouse Effect: Temperature of a Metal Sphere Surrounded by a Glass Shell and Heated by Sunlight

    Science.gov (United States)

    Nguyen, Phuc H.; Matzner, Richard A.

    2012-01-01

    We study the greenhouse effect on a model satellite consisting of a tungsten sphere surrounded by a thin spherical, concentric glass shell, with a small gap between the sphere and the shell. The system sits in vacuum and is heated by sunlight incident along the "z"-axis. This development is a generalization of the simple treatment of the…

  15. Students' Inventory of Social Actors Concerned by the Controversy Surrounding Cellular Telephones: A Case Study

    Science.gov (United States)

    Pouliot, Chantal

    2008-01-01

    The present article scrutinizes the manner with which a group of three postsecondary students (in Quebec, Canada) describe the social actors concerned by the controversy surrounding cellular telephones. The study was conducted on the basis of an ethnographic approach. Participant observation was performed by the researcher for 3 hours during each…

  16. The aerodynamic effects of passing trains to surrounding objects and people

    Science.gov (United States)

    2009-04-01

    Two safety issues are raised on the aerodynamic effects of a passing train on its surroundings. First, a high-speed train passing other trains on an adjacent track exerts aerodynamic pressure that can affect the structural integrity of window mount a...

  17. Children's Perception of Surroundings in an Unfamiliar Environment

    Science.gov (United States)

    Hergan, Irena

    2018-01-01

    This article presents the results of research on how ten-year-old children in an unfamiliar environment perceive the surroundings of the route during their wayfinding when they focus on the task of successfully orienting themselves with two different sources of cartographic support: a mobile navigator and a paper map. The results show that the…

  18. Brief Report: Service Implementation and Maternal Distress Surrounding Evaluation Recommendations for Young Children Diagnosed with Autism

    Science.gov (United States)

    Warren, Zachary; Vehorn, Alison; Dohrmann, Elizabeth; Newsom, Cassandra; Taylor, Julie Lounds

    2013-01-01

    There is limited evidence surrounding the ability of families of children with autism spectrum disorders to access and implement recommended interventions following diagnosis. The distress a family may encounter with regard to inability to access recommended services is also poorly understood. In this study, we present preliminary data regarding…

  19. Temporal properties of centre-surround interactions in human motion perception

    NARCIS (Netherlands)

    Perge, J.A.; Kanai, R.; Wezel, R.J.A. van; Lankheet, M.J.M.

    2003-01-01

    A recent electrophysiological study revealed that the response to the antagonistic surround of macaque area MT receptive fields is delayed (15 - 20 ms) relative to the centre (Perge et al, 2002 Investigative Ophthalmology & Visual Science 43 E-Abstract 3931). We investigated whether this phenomenon,

  20. Gas Flux and Density Surrounding a Cylindrical Aperture in the Free Molecular Flow Regime

    Science.gov (United States)

    Soulas, George C.

    2011-01-01

    The equations for rigorously calculating the particle flux and density surrounding a cylindrical aperture in the free molecular flow regime are developed and presented. The fundamental equations for particle flux and density from a reservoir and a diffusely reflecting surface will initially be developed. Assumptions will include a Maxwell-Boltzmann speed distribution, equal particle and wall temperatures, and a linear flux distribution along the cylindrical aperture walls. With this information, the equations for axial flux and density surrounding a cylindrical aperture will be developed. The cylindrical aperture will be divided into multiple volumes and regions to rigorously determine the surrounding axial flux and density, and appropriate limits of integration will be determined. The results of these equations will then be evaluated. The linear wall flux distribution assumption will be assessed. The axial flux and density surrounding a cylindrical aperture with a thickness-to-radius ratio of 1.25 will be presented. Finally, the equations determined in this study will be verified using multiple methods.

  1. Response of soil biota to vineyard interrow soil cultivation can be altered by the surrounding landscape

    Science.gov (United States)

    Zaller, Johann; Buchholz, Jacob; Querner, Pascal; Paredes, Daniel; Kratschmer, Sophie; Schwantzer, Martina; Winter, Silvia; Strauss, Peter; Bauer, Thomas; Burel, Françoise; Guernion, Muriel; Scimia, Jennifer; Nicolai, Annegret; Cluzeau, Daniel

    2017-04-01

    Ecosystem services provided by viticultural landscapes result from interactions between management intensity, soil properties, organisms inhabiting these landscapes, and the diversity and structure of the surrounding landscape. However, there is actually very little known to what extent these different factors influence the abundance and diversity of various soil biota. In this study we examined (i) to what extent different soil management intensities of interrows affect the activity and diversity of soil biota (earthworms, Collembola, litter decomposition), (ii) the role of soil properties in influencing these effects and (iii) whether the surrounding landscape structure is altering these interactions. We collected data in 16 vineyards in Austria embedded in landscapes with varying structure (i.e. from structurally simple to complex) and assessed earthworms (hand sorting), Collembola (pitfall trapping and soil coring), litter decomposition (tea bag method). Additionally, soil physical (water infiltration, aggregate stability, porosity, bulk density, soil texture) and chemical (pH, soil carbon content, cation exchange capacity, potassium, phosphorus) parameters were assessed. The landscape surrounding our vineyards within a radius of 750 m was assessed by field mapping using a geographical information system. Results showed that different soil biota/processes are differently affected by soil cultivation intensity and soil properties. Parameters describing the surrounding landscape interacted more with the responses of Collembola to soil cultivation than with earthworms or litter decomposition. These investigations are part of the transdisciplinary BiodivERsA project VineDivers (www.vinedivers.eu) and will ultimately lead into management recommendations for various stakeholders.

  2. On the Optimal Radiation Bandwidth of Printed Slot Antennas Surrounded by EBGs

    NARCIS (Netherlands)

    Neto, A.; Llombart, N.; Gerini, G.; Maagt, P. de

    2006-01-01

    This paper describes a design strategy to achieve the maximum bandwidth and efficiency for a printed slot antenna surrounded by EBGs. First the dielectric constant and the thickness of the dielectric slab that guarantees an acceptable front to back radiation ratio is identified. Then electromagnetic

  3. Guest replacement in a flexible single-crystal host by mixing the surrounding gas.

    Science.gov (United States)

    Takamizawa, Satoshi; Miyake, Ryosuke

    2009-07-21

    The adsorption behavior of a single-crystal host [Cu2(bza)4(pyz)]n under vapor was studied by adsorption measurements and single-crystal X-ray analyses, demonstrating the sharp replacement of the included guest by mixing the surrounding vapor.

  4. Developmental Changes during Childhood in Single-Letter Acuity and Its Crowding by Surrounding Contours

    Science.gov (United States)

    Jeon, Seong Taek; Hamid, Joshua; Maurer, Daphne; Lewis, Terri L.

    2010-01-01

    Crowding refers to impaired target recognition caused by surrounding contours. We investigated the development of crowding in central vision by comparing single-letter and crowding thresholds in groups of 5-year-olds, 8-year-olds, 11-year-olds, and adults. The task was to discriminate the orientation of a Sloan letter E. Single-letter thresholds,…

  5. Climate change impacts on terrestrial ecosystems in metropolitan Chicago and its surrounding, multi-state region

    Science.gov (United States)

    Jessica J. Hellmann; Knute J. Nadelhoffer; Louis R. Iverson; Lewis H. Ziska; Stephen N. Matthews; Philip Myers; Anantha M. Prasad; Matthew P. Peters

    2010-01-01

    This paper describes the potential impacts of warming temperatures and changing precipitation on plants, wildlife, invasive species, pests, and agricultural ecosystems across the multi-state region centered on Chicago, Illinois. We examine a geographic area that captures much of Lake Michigan, including a complex mosaic of urbanization and agriculture surrounding...

  6. Difference of hydrological cycle between Islands and surrounding oceans over the Indonesian maritime continent

    Science.gov (United States)

    Kanamori, H.; Yasunari, T.

    2011-12-01

    The climate of the maritime continent is characterized by huge amounts of precipitation throughout the year and plays an essential role as a major atmospheric heat source of the Earth's climate system. The unique environment in this region with complex distribution of islands and warm pool favors the development of deep and frequent convection. The deep convection accompanied by heavy precipitation is generally observed over islands and its surrounding ocean rather than open seas. Major islands combined with surrounding warm seas, therefore, are most likely to play an important part in the energy and water cycle processes driving the complex atmospheric circulation pattern. To understand the time-space characteristics of the hydro-climate in Borneo, and its surrounding ocean, we examined the climatological hydrological cycle on monthly mean basis by using TRMM and JRA25/JCDAS reanalysis data from 1999-2010. The interactive nature between the hydro-climate and the tropical rainforest were also discussed. Seasonal variation of precipitation over Borneo and the surrounding ocean is very small compared with it in other tropics. The vertically- integrated moisture flux from surface to 100 hPa shows divergence throughout the year over the Borneo, suggesting that this island plays moisture source to atmosphere. In contrast, other major islands in the maritime continent, such as New Guina and Sumatra, seasonal cycle of the moisture flux convergence is clearly observed. The evapotranspiration, as defined by residual from precipitation and moisture flux convergence, contributes to precipitation over Borneo throughout the year. On the other hand, the contribution of moisture flux convergence for precipitation is noticeable over the surrounding ocean of Borneo, particularly during the boreal winter. The seasonal cycle of circulation pattern influences water budget over coastal area. These results strongly suggest that precipitation in the Borneo is basically occupied by

  7. Alteration of functional connectivity within visuospatial working memory-related brain network in patients with right temporal lobe epilepsy: a resting-state fMRI study.

    Science.gov (United States)

    Lv, Zong-xia; Huang, Dong-Hong; Ye, Wei; Chen, Zi-rong; Huang, Wen-li; Zheng, Jin-ou

    2014-06-01

    This study aimed to investigate the resting-state brain network related to visuospatial working memory (VSWM) in patients with right temporal lobe epilepsy (rTLE). The functional mechanism underlying the cognitive impairment in VSWM was also determined. Fifteen patients with rTLE and 16 healthy controls matched for age, gender, and handedness underwent a 6-min resting-state functional MRI session and a neuropsychological test using VSWM_Nback. The VSWM-related brain network at rest was extracted using multiple independent component analysis; the spatial distribution and the functional connectivity (FC) parameters of the cerebral network were compared between groups. Behavioral data were subsequently correlated with the mean Z-value in voxels showing significant FC difference during intergroup comparison. The distribution of the VSWM-related resting-state network (RSN) in the group with rTLE was virtually consistent with that in the healthy controls. The distribution involved the dorsolateral prefrontal lobe and parietal lobe in the right hemisphere and the partial inferior parietal lobe and posterior lobe of the cerebellum in the left hemisphere (p<0.05, AlphaSim corrected). Between-group differences suggest that the group with rTLE had a decreased FC within the right superior frontal lobe (BA8), right middle frontal lobe, and right ventromedial prefrontal lobe compared with the controls (p<0.05, AlphaSim corrected). The regions of increased FC in rTLE were localized within the right superior frontal lobe (BA11), right superior parietal lobe, and left posterior lobe of the cerebellum (p<0.05, AlphaSim corrected). Moreover, patients with rTLE performed worse than controls in the VSWM_Nback test, and there were negative correlations between ACCmeanRT (2-back) and the mean Z-value in the voxels showing decreased or increased FC in rTLE (p<0.05). The results suggest that the alteration of the VSWM-related RSN might underpin the VSWM impairment in patients with rTLE and

  8. The facilitative effect of transcranial direct current stimulation on visuospatial working memory in patients with diabetic polyneuropathy: a pre-post sham-controlled study

    Directory of Open Access Journals (Sweden)

    YI-JEN WU

    2016-09-01

    Full Text Available Diabetes mellitus (DM can lead to diabetic polyneuropathy (DPN and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM capacity and DPN severity, and attempted to improve VSWM in DPN patients via the use of transcranial direct current stimulation (tDCS. Sixteen DPN patients and sixteen age- and education-matched healthy control subjects received Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV and Montreal Cognitive Assessment (MOCA for baseline cognitive assessment. A forward- and backward-recall computerized Corsi block tapping task (CBT, both with and without a concurrent motor interference task was used to measure VSWM capacity. Each DPN patient underwent a pre-treatment CBT, followed by tDCS or sham treatment, then a post-treatment CBT on two separate days. We found that although patients with severe DPN (Dyck’s grade 2a or 2b showed comparable general intelligence scores on WAIS-IV as their age- and education-matched healthy counterparts, they nonetheless showed mild cognitive impairment on MOCA and working memory deficit on digit-span test of WAIS-IV. Furthermore, patients’ peripheral nerve conduction velocity (NCV was positively correlated with their VSWM span in the most difficult CBT condition that involved backward-recall with motor interference such that patients with worse NCV also had lower VSWM span. Most importantly, anodal tDCS over the right DLPFC was able to improve low-performing patients’ VSWM span to be on par with the high-performers, thereby eliminating the correlation between NCV and VSWM. In summary, these findings suggest that 1 mild cognitive impairment and severe peripheral neuropathy can coexist with unequal severity in diabetic patients, 2 the positive correlation of VSWM and NCV suggests a link between peripheral and central neuropathies and 3 anodal tDCS over the right DLPFC can

  9. Do aging and dual-tasking impair the capacity to store and retrieve visuospatial information needed to guide perturbation-evoked reach-to-grasp reactions?

    Directory of Open Access Journals (Sweden)

    Kenneth C Cheng

    Full Text Available A recent study involving young adults showed that rapid perturbation-evoked reach-to-grasp balance-recovery reactions can be guided successfully with visuospatial-information (VSI retained in memory despite: 1 a reduction in endpoint accuracy due to recall-delay (time between visual occlusion and perturbation-onset, PO and 2 slowing of the reaction when performing a concurrent cognitive task during the recall-delay interval. The present study aimed to determine whether this capacity is compromised by effects of aging. Ten healthy older adults were tested with the previous protocol and compared with the previously-tested young adults. Reactions to recover balance by grasping a small handhold were evoked by unpredictable antero-posterior platform-translation (barriers deterred stepping reactions, while using liquid-crystal goggles to occlude vision post-PO and for varying recall-delay times (0-10 s prior to PO (the handhold was moved unpredictably to one of four locations 2 s prior to vision-occlusion. Subjects also performed a spatial- or non-spatial-memory cognitive task during the delay-time in a subset of trials. Results showed that older adults had slower reactions than the young across all experimental conditions. Both age groups showed similar reduction in medio-lateral end-point accuracy when recall-delay was longest (10 s, but differed in the effect of recall delay on vertical hand elevation. For both age groups, engaging in either the non-spatial or spatial-memory task had similar (slowing effects on the arm reactions; however, the older adults also showed a dual-task interference effect (poorer cognitive-task performance that was specific to the spatial-memory task. This provides new evidence that spatial working memory plays a role in the control of perturbation-evoked balance-recovery reactions. The delays in completing the reaction that occurred when performing either cognitive task suggest that such dual-task situations in daily

  10. Can texture of tissue surrounding microcalcifications in mammography be used for breast cancer diagnosis?

    Energy Technology Data Exchange (ETDEWEB)

    Karahaliou, A.; Boniatis, I.; Sakellaropoulos, P.; Skiadopoulos, S.; Panayiotakis, G. [Department of Medical Physics, School of Medicine, University of Patras, Patras 265 00 (Greece); Costaridou, L. [Department of Medical Physics, School of Medicine, University of Patras, Patras 265 00 (Greece)], E-mail: costarid@upatras.gr

    2007-10-01

    This study investigates whether texture properties of the tissue surrounding microcalcifications (MCs) can contribute to breast cancer diagnosis. A case sample of 100 MC clusters (46 benign, 54 malignant) from 85 dense mammographic images included in the Digital Database for Screening Mammography, is analyzed. Regions of interest containing clusters are processed using wavelet-based enhancement and individual MCs are segmented by local thresholding. The segmented MCs are removed from original image data and the surrounding tissue area is subjected to texture analysis. The feasibility of four texture feature sets (first-order statistics, gray level co-occurrence matrices, gray level run length matrices and Laws' texture energy measures) in discriminating malignant from benign tissue was investigated using a k-nearest neighbor classifier. Laws' texture energy measures achieved the best classification accuracy 89% (sensitivity 90.74% and specificity 86.96%)

  11. Camouflaging in a complex environment--octopuses use specific features of their surroundings for background matching.

    Directory of Open Access Journals (Sweden)

    Noam Josef

    Full Text Available Living under intense predation pressure, octopuses evolved an effective and impressive camouflaging ability that exploits features of their surroundings to enable them to "blend in." To achieve such background matching, an animal may use general resemblance and reproduce characteristics of its entire surroundings, or it may imitate a specific object in its immediate environment. Using image analysis algorithms, we examined correlations between octopuses and their backgrounds. Field experiments show that when camouflaging, Octopus cyanea and O. vulgaris base their body patterns on selected features of nearby objects rather than attempting to match a large field of view. Such an approach enables the octopus to camouflage in partly occluded environments and to solve the problem of differences in appearance as a function of the viewing inclination of the observer.

  12. Stability Evaluation on Surrounding Rocks of Underground Powerhouse Based on Microseismic Monitoring

    Directory of Open Access Journals (Sweden)

    Feng Dai

    2015-01-01

    Full Text Available To study the stability of underground powerhouse at Houziyan hydropower station during excavation, a microseismic monitoring system is adopted. Based on the space-time distribution characteristics of microseismic events during excavation of the main powerhouse, the correlation between microseismic events and blasting construction is established; and the microseismic clustering areas of the underground powerhouse are identified and delineated. The FLAC3D code is used to simulate the deformation of main powerhouse. The simulated deformation characteristics are consistent with that recorded by microseismic monitoring. Finally, the correlation between the macroscopic deformation of surrounding rock mass and microseismic activities is also revealed. The results show that multiple faults between 1# and 3# bus tunnels are activated during excavation of floors V and VI of the main powerhouse. The comprehensive method combining microseismic monitoring with numerical simulation as well as routine monitoring can provide an effective way to evaluate the surrounding rock mass stability of underground caverns.

  13. Effects of fluorine emission on agricultural products surrounding an aluminum factory

    Energy Technology Data Exchange (ETDEWEB)

    Muramoto, S.; Nishizaki, H.; Aoyama, I. (Research Institute for Bioresources, Okayama University, Kurashiki (Japan))

    1991-06-01

    The F concentrations of precipitate dust, agricultural products, and fingernail and hair at the surrounding Al factory were investigated. The F content of dust ranged from 15400 to 42500 micrograms/g dry weight, 190,000 to 380,000 micrograms/g Al. Rice grain contained about 3.4 times more F than that in the control area, but some kinds of agricultural products, egg plants (S. melongena L.), mulberry plants (M. japonica Bailey non Sieb.), and soy beans (G. max (L.) Merrill) were almost equal to that of controls. Also, the high F concentration in the hair and nails of some workers was affected by available F contents in the emission from the factory as well as food and water surrounding the aluminum factory compared with those of control area.

  14. The Effects of GH Transgenic Goats on the Microflora of the Intestine, Feces and Surrounding Soil.

    Directory of Open Access Journals (Sweden)

    Zekun Bao

    Full Text Available The development of genetically engineered animals has brought with it increasing concerns about biosafety issues. We therefore evaluated the risks of growth hormone from transgenic goats, including the probability of horizontal gene transfer and the impact on the microbial community of the goats' gastrointestinal tracts, feces and the surrounding soil. The results showed that neither the GH nor the neoR gene could be detected in the samples. Moreover, there was no significant change in the microbial community of the gastrointestinal tracts, feces and soil, as tested with PCR-denaturing gradient gel electrophoresis and 16S rDNA sequencing. Finally, phylogenetic analysis showed that the intestinal content, feces and soil samples all contained the same dominant group of bacteria. These results demonstrated that expression of goat growth hormone in the mammary of GH transgenic goat does not influence the microflora of the intestine, feces and surrounding soil.

  15. Surrounding control of nonlinear multi-agent systems with non-identical agents.

    Science.gov (United States)

    Shoja, Shamisa; Baradarannia, Mahdi; Hashemzadeh, Farzad; Badamchizadeh, Mohammadali; Bagheri, Peyman

    2017-09-01

    In this paper, the surrounding control problem of a group of non-identical agents is considered, where a team of followers achieves an equidistant distributed formation to surround a team of moving leaders. An adaptive design method is presented for multi-agent systems where the dynamics of agents are supposed to be nonlinear with unknown parameters. First, an estimator for the center of the leaders is introduced. Then, two distributed adaptive controllers based on the estimated center are proposed for each follower. The stability and parameter convergence of the proposed protocols are shown by using algebraic graph theory and Lyapunov theory. Finally, a numerical example is provided to validate the theoretical results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  16. Confronting, Confirming, and Dispelling Myths Surrounding ERP-in-the-Cloud

    DEFF Research Database (Denmark)

    Beaulieu, Tanya; C. Martin, Todd; Sarker, Saonee

    2015-01-01

    understanding about the true challenges related to ERP cloud computing, it is important to examine these myths in an effort to dispel or support them. In this paper, we attempt to achieve that. Specifically, we explore eight myths related to cloud-based ERP systems through a study involving in-depth interviews......Although cloud computing is still in its infancy, it is rapidly becoming one of the most used buzzwords in the IS/IT field and ERP-systems are one of the fastest growing SaaS cloud applications. However, given the relative newness of ERP cloud computing, and the lack of empirical research...... on the topic, there is substantial uncertainty surrounding the benefits and challenges of ERP cloud computing. Consequently, as often is the case with new technologies, popular myths surrounding the technology are used to make adoption and implementation decisions. As a first step toward providing an informed...

  17. Nanofocusing performance of the crescent-shaped cylinder for various surrounding media

    Directory of Open Access Journals (Sweden)

    Hong-Wei Wu

    2014-11-01

    Full Text Available In this work, adjustable broadband light harvesting and field enhancement on the surface of a crescent-shaped cylinder were achieved by considering the surrounding medium in conformal transformation theory. The continuous absorption spectrum shows that the broadband effect is quite robust to the surrounding media. By considering the material properties, we provide a comprehensive discussion of how the material properties of the nanosystem affect the field enhancement and nanofocusing. Furthermore, an optical gain medium is employed to compensate for the absorption losses in the materials. A considerable field enhancement and super-nanofocusing are thus expected. The presented results provide important guidance for optimizing such a nanosystem in experimental studies.

  18. Real-time and low-cost embedded platform for car's surrounding vision system

    Science.gov (United States)

    Saponara, Sergio; Franchi, Emilio

    2016-04-01

    The design and the implementation of a flexible and low-cost embedded system for real-time car's surrounding vision is presented. The target of the proposed multi-camera vision system is to provide the driver a better view of the objects that surround the vehicle. Fish-eye lenses are used to achieve a larger Field of View (FOV) but, on the other hand, introduce radial distortion of the images projected on the sensors. Using low-cost cameras there could be also some alignment issues. Since these complications are noticeable and dangerous, a real-time algorithm for their correction is presented. Then another real-time algorithm, used for merging 4 camera video streams together in a single view, is described. Real-time image processing is achieved through a hardware-software platform

  19. The effect of wind direction and building surroundings on a marina bay in the Black Sea

    Science.gov (United States)

    Katona, Cosmin; Safta, Carmen Anca

    2017-01-01

    The wind effect has usually a major importance in the marina bay. These environmental sites are an interplay between tourist and commercial activities, requiring a high-detailed and definition studies of the dynamic fluid in the harbor. Computational Fluid Dynamics (CFD) has been used elaborately in urban surroundings research. However, most CFD studies were performed for harbors for only a confined number of wind directions and/or without considering the building surroundings effects. This paper presents the results of different simulations based on various wind flows and the CFD simulation of coupled urban wind flow and general wind directions upon a semi-closed area. Thus the importance of wind effects on the evaluation of the marina bay will be pointed out to achieve a safe and secure mooring at the berth and eventually a good potential of renewable energy for an impending green harbor.

  20. Not worth the fuss after all? cross-sectional and prospective data on violent video game influences on aggression, visuospatial cognition and mathematics ability in a sample of youth.

    Science.gov (United States)

    Ferguson, Christopher J; Garza, Adolfo; Jerabeck, Jessica; Ramos, Raul; Galindo, Mariza

    2013-01-01

    The United States Supreme Court's recent decision relating to violent video games revealed divisions within the scientific community about the potential for negative effects of such games as well as the need for more, higher quality research. Scholars also have debated the potential for violent games to have positive effects such as on visuospatial cognition or math ability. The current study sought to extend previous literature by using well-validated clinical outcome measures for relevant constructs, which have generally been lacking in past research. Cross-section data on aggression, visuospatial cognition, and math achievement were available for a sample of 333 (51.7 % female) mostly Hispanic youth (mean age = 12.76). Prospective 1-year data on aggression and school GPA were available for 143 (46.2 % female) of those youth. Results from both sets of analysis revealed that exposure to violent game had neither short-term nor long-term predictive influences on either positive or negative outcomes. A developmental analysis of the cross-sectional data revealed that results did not differ across age categories of older children, preadolescents or adolescents. Analysis of effect sizes largely ruled out Type II error as a possible explanation for null results. Suggestions for new directions in the field of video game research are proffered.