WorldWideScience

Sample records for subjects visually controlled

  1. Visiting Richard Serra’s Promenade sculpture improves postural control and judgment of subjective visual vertical.

    Directory of Open Access Journals (Sweden)

    Zoï eKapoula

    2014-12-01

    Full Text Available Body sway while maintaining an upright quiet stance reflects an active process of balance based on the integration of visual, vestibular, somatosensory and proprioceptive inputs. Richard Serra’s Promenade sculpture featured in the 2008 Monumenta exhibition at the Grand Palais in Paris, France is herein hypothesised to have stimulated the body’s vertical and longitudinal axes as it showcased 5 monumental rectangular solids pitched at a 1.69° angle.Using computerised dynamic posturography we measured the body sway of 23 visitors when fixating a cross, or when observing the artwork (fixating it or actively exploring it with eye movements before and after walking around and alongside the sculpture (i.e., before and after a promenade. A first fixation at the sculpture increased medio-lateral stability (in terms of spectral power of body sway. Eye movement exploration in the depth of the sculpture increased antero-posterior stability (in terms of spectral power and cancelling time of body sway at the expense of medio-lateral stability (in terms of cancelling time. Moreover, a medio-lateral instability associated with eye movement exploration before the promenade (in terms of body sway sensu stricto was cancelled after the promenade. Finally, the overall medio-lateral stability (in terms of spectral power increased after the promenade.Fourteen additional visitors were asked to sit in a dark room and adjust a luminous line to what they considered to be the earth-vertical axis. The promenade executed within the sculpted environment afforded by Serra’s monumental statuary works resulted in significantly improved performances on the subjective visual vertical test.We attribute these effects to the sculpted environment provided by the exhibition which may have acted as a kind of physiologic training ground thereby improving the visitors’ overall sense of visual perspective, equilibrium and gravity.

  2. Lateral Inhibition in the Human Visual System in Patients with Glaucoma and Healthy Subjects: A Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Francisco G Junoy Montolio

    Full Text Available In glaucoma, the density of retinal ganglion cells is reduced. It is largely unknown how this influences retinal information processing. An increase in spatial summation and a decrease in contrast gain control and contrast adaptation have been reported. A decrease in lateral inhibition might also arise. This could result in a larger than expected response to some stimuli, which could mask ganglion cell loss on functional testing (structure-function discrepancy. The aim of this study was to compare lateral inhibition between glaucoma patients and healthy subjects; we used a case-control design. Cases (n = 18 were selected to have advanced visual field loss in combination with a normal visual acuity. Controls (n = 50 were not allowed to have symptoms or signs of any eye disease. Lateral inhibition was measured psychophysically on a computer screen, with (1 a modified illusory movement experiment and (2 a contrast sensitivity (CS test. Illusory movement was quantified by nulling it with a real movement; measure of lateral inhibition was the amount of illusory movement. CS was measured at 1 and 4 cycles per degree (cpd; measure of lateral inhibition was the difference between log CS at 4 and 1 cpd. Both measures were compared between cases and controls; analyses were adjusted for age and gender. There was no difference between cases and controls for these two measures of lateral inhibition (p = 0.58 for illusory movement; p = 0.20 for CS. The movement threshold was higher in cases than in controls (p = 0.008 and log CS was lower, at both 1 (-0.20; p = 0.008 and 4 (-0.28; p = 0.001 cpd. Our results indicate that spatially antagonistic mechanisms are not specifically affected in glaucoma, at least not in the intact center of a severely damaged visual field. This suggests that the structure-function discrepancy in glaucoma is not related to a decrease in lateral inhibition.

  3. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis.

    Science.gov (United States)

    Chang, Yi-Tzu; Meng, Ling-Fu; Chang, Chun-Ju; Lai, Po-Liang; Lung, Chi-Wen; Chern, Jen-Suh

    2017-01-01

    Subjective visual vertical (SVV) judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS). Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs), the present study examined the effect of postural control demands (PDs) on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group) and 13 age-matched adolescents (control group) aged 12-18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test) as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion), SVV (accuracy and reaction time), and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components) was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1) during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2) the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for central

  4. Effect of Postural Control Demands on Early Visual Evoked Potentials during a Subjective Visual Vertical Perception Task in Adolescents with Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Yi-Tzu Chang

    2017-06-01

    Full Text Available Subjective visual vertical (SVV judgment and standing stability were separately investigated among patients with adolescent idiopathic scoliosis (AIS. Although, one study has investigated the central mechanism of stability control in the AIS population, the relationships between SVV, decreased standing stability, and AIS have never been investigated. Through event-related potentials (ERPs, the present study examined the effect of postural control demands (PDs on AIS central mechanisms related to SVV judgment and standing stability to elucidate the time-serial stability control process. Thirteen AIS subjects (AIS group and 13 age-matched adolescents (control group aged 12–18 years were recruited. Each subject had to complete an SVV task (i.e., the modified rod-and-frame [mRAF] test as a stimulus, with online electroencephalogram recording being performed in the following three standing postures: feet shoulder-width apart standing, feet together standing, and tandem standing. The behavioral performance in terms of postural stability (center of pressure excursion, SVV (accuracy and reaction time, and mRAF-locked ERPs (mean amplitude and peak latency of the P1, N1, and P2 components was then compared between the AIS and control groups. In the behavioral domain, the results revealed that only the AIS group demonstrated a significantly accelerated SVV reaction time as the PDs increased. In the cerebral domain, significantly larger P2 mean amplitudes were observed during both feet shoulder-width-apart standing and feet together standing postures compared with during tandem standing. No group differences were noted in the cerebral domain. The results indicated that (1 during the dual-task paradigm, a differential behavioral strategy of accelerated SVV reaction time was observed in the AIS group only when the PDs increased and (2 the decrease in P2 mean amplitudes with the increase in the PD levels might be direct evidence of the competition for

  5. Visual perception of spatial subjects

    Energy Technology Data Exchange (ETDEWEB)

    Osterloh, K.R.S.; Ewert, U. [Federal Institute for Materials Research and Testing (BAM), Berlin (Germany)

    2007-07-01

    Principally, any imaging technology consists of two consecutive, though strictly separated processes: data acquisition and subsequent processing to generate an image that can be looked at, either on a monitor screen or printed on paper. Likewise, the physiological process of viewing can be separated into vision and perception, though these processes are much more overlapping. Understanding the appearance of a subject requires the entire sequence from receiving the information carried e.g. by photons up to an appropriate processing leading to the perception of the subject shown. As a consequence, the imagination of a subject is a result of both, technological and physiological processes. Whenever an evaluation of an image is critical, also the physiological part of the processing should be considered. However, an image has two dimensions in the first place and reality is spatial, it has three dimensions. This problem has been tackled on a philosophical level at least since Platon's famous discussion on the shadow image in a dark cave. The mere practical point is which structural details can be perceived and what may remain undetected depending on the mode of presentation. This problem cannot be resolved without considering each single step of visual perception. Physiologically, there are three 'tools' available to understanding the spatial structure of a subject: binocular viewing, following the course of perspective projection and motion to collect multiple aspects. Artificially, an object may be cut in various ways to display the interior or covering parts could be made transparent within a model. Samples will be shown how certain details of a subject can be emphasised or hidden depending on the way of presentation. It needs to be discussed what might help to perceive the true spatial structure of a subject with all relevant details and what could be misleading. (authors)

  6. Comparison of postural control between healthy subjects and individuals with nonspecific low back pain during exposure to visual stimulus.

    Science.gov (United States)

    Li, Rui; Wang, Ninghua; Yan, Xiang; Wei, Kunlin

    2014-01-01

    Low back pain (LBP) is a common clinical problem. Many researchers have demonstrated that LBP disorders have difference in sensory strategies for postural control. Optokinetic stimulation (OKS) of optic flow has been widely applied to study its effect on vision, but has not been applied to LBP. Here we used OKS on different surfaces to investigate the characteristics of chronic nonspecific LBP (CNLBP) posture control, so as to provide new theoretical and experimental data for further recognizing CNLBP and enriching its treatment. Fifteen individuals with CNLBP (age range 25-40 years) and 15 age and gender-matched control subjects were recruited. Each subject, while standing on a stable or soft surface, was exposed to random-dot patterns projected on a large screen, with the dots displaying expansion (+) and contraction (-) and velocities including 80°, 40°, and 20° per second. The visual stimulus used a "stimuli-interval" pattern. The peak velocity, different phases' standard deviation (SD) of the anterior-posterior centre of pressure (COP) displacements and the total length of the medial-lateral COP sway (LML) for stable surface and soft surface were recorded by force platform. The main effect of surface on all parameters was significant, while the main effect of group and OKS showed no significance with the exception of peak velocity (F(3, 95) = 3.6, P = 0.01) and A2 (F(5, 140) = 9.34, P A2 (F(5, 140) = 3.65, P < 0.01) and group by surface by OKS (F(5,140) = 2.83, P = 0.02), and surface by OKS of A1 and A3 (P < 0.05) were significant. It was reported that significantly more SD in amplitude in the T2 phase was seen in persons with CNLBP when confronting the + 40 stimuli on the soft surface (P < 0.05) compared to healthy individuals. There was no significance between persons with CNLBP and healthy people when using the stable surface. Subjects with LBP showed decreased efficiency of postural adjustment when exposed to more complicated tasks and environments

  7. Visual imagery without visual perception: lessons from blind subjects

    Science.gov (United States)

    Bértolo, Helder

    2014-08-01

    The question regarding visual imagery and visual perception remain an open issue. Many studies have tried to understand if the two processes share the same mechanisms or if they are independent, using different neural substrates. Most research has been directed towards the need of activation of primary visual areas during imagery. Here we review some of the works providing evidence for both claims. It seems that studying visual imagery in blind subjects can be used as a way of answering some of those questions, namely if it is possible to have visual imagery without visual perception. We present results from the work of our group using visual activation in dreams and its relation with EEG's spectral components, showing that congenitally blind have visual contents in their dreams and are able to draw them; furthermore their Visual Activation Index is negatively correlated with EEG alpha power. This study supports the hypothesis that it is possible to have visual imagery without visual experience.

  8. Postural control in blind subjects

    Directory of Open Access Journals (Sweden)

    Antonio Vinicius Soares

    2011-12-01

    Full Text Available Objective: To analyze postural control in acquired and congenitally blind adults. Methods: A total of 40 visually impaired adults participated in the research, divided into 2 groups, 20 with acquired blindness and 20 with congenital blindness - 21 males and 19 females, mean age 35.8 ± 10.8. The Brazilian version of Berg Balance Scale and the motor domain of functional independence measure were utilized. Results: On Berg Balance Scale the mean for acquired blindness was 54.0 ± 2.4 and 54.4 ± 2.5 for congenitally blind subjects; on functional independence measure the mean for acquired blind group was 87.1 ± 4.8 and 87.3 ± 2.3 for congenitally blind group. Conclusion: Based upon the scale used the results suggest the ability to control posture can be developed by compensatory mechanisms and it is not affected by visual loss in congenitally and acquired blindness.

  9. Lateral inhibition in the human visual system in patients with glaucoma and healthy subjects: A case-control study

    NARCIS (Netherlands)

    F.G.J. Montolio (Francisco G. Junoy); W. Meems (Wilma); M.S.A. Janssens (Marieke S. A.); L. Stam (Lucas); N.M. Jansonius (Nomdo)

    2016-01-01

    textabstractIn glaucoma, the density of retinal ganglion cells is reduced. It is largely unknown how this influences retinal information processing. An increase in spatial summation and a decrease in contrast gain control and contrast adaptation have been reported. A decrease in lateral inhibition

  10. Lateral Inhibition in the Human Visual System in Patients with Glaucoma and Healthy Subjects : A Case-Control Study

    NARCIS (Netherlands)

    Junoy Montolio, Francisco G; Meems, Wilma; Janssens, Marieke S A; Stam, Lucas; Jansonius, Nomdo M

    2016-01-01

    In glaucoma, the density of retinal ganglion cells is reduced. It is largely unknown how this influences retinal information processing. An increase in spatial summation and a decrease in contrast gain control and contrast adaptation have been reported. A decrease in lateral inhibition might also

  11. Mesopic Functional Visual Acuity in Normal Subjects.

    Directory of Open Access Journals (Sweden)

    Takahiro Hiraoka

    Full Text Available To evaluate mesopic functional visual acuity (FVA with a newly developed system in normal subjects and to compare the results with photopic FVA, sixty-eight healthy volunteers (24.03 ± 4.42 [mean ± standard deviation] years were enrolled in this study. A commercially available FVA measurement system (AS-28; Kowa, Aichi, Japan was modified to measure FVA under mesopic conditions as well as photopic conditions. Measurements were performed monocularly in photopic conditions during 60 seconds. After dark adaptation for 15 minutes, the same measurements were repeated in mesopic conditions. Outcomes included starting visual acuity (VA, FVA (the average of VAs, visual maintenance ratio (VMR, maximum VA, minimum VA, and numbers of blinks during the 60-second measurement session, and were compared between mesopic and photopic conditions. Starting VA was -0.11 ± 0.08 and 0.39 ± 0.12 logarithm of the minimum angle of resolution (logMAR in photopic and mesopic conditions, respectively. FVA was -0.06 ± 0.09 and 0.52 ± 0.14 logMAR, VMR was 0.98 ± 0.02 and 0.94 ± 0.04, maximum VA was -0.15 ± 0.06 and 0.33 ± 0.12 logMAR, the minimum VA was 0.05 ± 0.12 and 0.78 ± 0.20 logMAR, and the number of blinks was 8.23 ± 7.54 and 7.23 ± 6.20, respectively. All these parameters except the number of blinks were significantly different between the two conditions (P < 0.001. Besides, the difference between maximum and minimum VAs and standard deviation of VA were significantly larger in mesopic than in photopic conditions (P < 0.001. This study revealed that not only overall visual function decline but also instability of vision under mesopic conditions even in healthy subjects.

  12. Differential effects of visual feedback on subjective visual vertical accuracy and precision.

    Directory of Open Access Journals (Sweden)

    Daniel Bjasch

    Full Text Available The brain constructs an internal estimate of the gravitational vertical by integrating multiple sensory signals. In darkness, systematic head-roll dependent errors in verticality estimates, as measured by the subjective visual vertical (SVV, occur. We hypothesized that visual feedback after each trial results in increased accuracy, as physiological adjustment errors (A-/E-effect are likely based on central computational mechanisms and investigated whether such improvements were related to adaptational shifts of perceived vertical or to a higher cognitive strategy. We asked 12 healthy human subjects to adjust a luminous arrow to vertical in various head-roll positions (0 to 120deg right-ear down, 15deg steps. After each adjustment visual feedback was provided (lights on, display of previous adjustment and of an earth-vertical cross. Control trials consisted of SVV adjustments without feedback. At head-roll angles with the largest A-effect (90, 105, and 120deg, errors were reduced significantly (p0.05 influenced. In seven subjects an additional session with two consecutive blocks (first with, then without visual feedback was completed at 90, 105 and 120deg head-roll. In these positions the error-reduction by the previous visual feedback block remained significant over the consecutive 18-24 min (post-feedback block, i.e., was still significantly (p<0.002 different from the control trials. Eleven out of 12 subjects reported having consciously added a bias to their perceived vertical based on visual feedback in order to minimize errors. We conclude that improvements of SVV accuracy by visual feedback, which remained effective after removal of feedback for ≥18 min, rather resulted from a cognitive strategy than by adapting the internal estimate of the gravitational vertical. The mechanisms behind the SVV therefore, remained stable, which is also supported by the fact that SVV precision - depending mostly on otolith input - was not affected by visual

  13. Beyond Bombardment: Subjectivity, Visual Culture, and Art Education

    Science.gov (United States)

    Eisenhauer, Jennifer F.

    2006-01-01

    Beginning with an understanding of visual culture as a postmodern discourse, this article argues for more focused attention to how visual culture presents a critical rethinking of subjectivity within art education. Through an analysis of a language of bombardment, a discourse that positions the subject as bombarded by media messages, this article…

  14. Auditory and visual 3D virtual reality therapy as a new treatment for chronic subjective tinnitus: Results of a randomized controlled trial.

    Science.gov (United States)

    Malinvaud, D; Londero, A; Niarra, R; Peignard, Ph; Warusfel, O; Viaud-Delmon, I; Chatellier, G; Bonfils, P

    2016-03-01

    Subjective tinnitus (ST) is a frequent audiologic condition that still requires effective treatment. This study aimed at evaluating two therapeutic approaches: Virtual Reality (VR) immersion in auditory and visual 3D environments and Cognitive Behaviour Therapy (CBT). This open, randomized and therapeutic equivalence trial used bilateral testing of VR versus CBT. Adult patients displaying unilateral or predominantly unilateral ST, and fulfilling inclusion criteria were included after giving their written informed consent. We measured the different therapeutic effect by comparing the mean scores of validated questionnaires and visual analog scales, pre and post protocol. Equivalence was established if both strategies did not differ for more than a predetermined limit. We used univariate and multivariate analysis adjusted on baseline values to assess treatment efficacy. In addition of this trial, purely exploratory comparison to a waiting list group (WL) was provided. Between August, 2009 and November, 2011, 148 of 162 screened patients were enrolled (VR n = 61, CBT n = 58, WL n = 29). These groups did not differ at baseline for demographic data. Three month after the end of the treatment, we didn't find any difference between VR and CBT groups either for tinnitus severity (p = 0.99) or tinnitus handicap (p = 0.36). VR appears to be at least as effective as CBT in unilateral ST patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. The Subjective Visual Vertical: Validation of a Simple Test

    Science.gov (United States)

    Tesio, Luigi; Longo, Stefano; Rota, Viviana

    2011-01-01

    The study sought to provide norms for a simple test of visual perception of verticality (subjective visual vertical). The study was designed as a cohort study with a balanced design. The setting was the Rehabilitation Department of a University Hospital. Twenty-two healthy adults, of 23-58 years, 11 men (three left handed) and 11 women (three left…

  16. Subjective visual acuity with simulated defocus.

    Science.gov (United States)

    Dehnert, Anne; Bach, Michael; Heinrich, Sven P

    2011-11-01

    Artificial degradation of vision by inducing dioptric blur is frequently used for evaluating diagnostic equipment. However, the use of lenses is prone to errors as it is adversely affected by eyelid squinting, pupil size, and imprecise lens position. The alternative is a degradation of the stimuli themselves based on a Fourier-optical mathematical model. With this, however, perceptual effects such as 'simultaneous blur' induced by the surround may affect acuity. We tested whether both methods, lens induced defocus and mathematical stimulus degradation, yield concordant results. We compared both methods in normal subjects, measuring Landolt C acuity at five different levels of defocus from 0 to 8 dioptres. The pupil size was determined individually, chromatic aberrations were avoided by using a monochromatic approach, and a correction for spectacle magnification was included. Otherwise, the experimental design was kept deliberately simple to remain comparable to typical applications. With the major sources of error associated with the use of lenses being accounted for, both methods yield similar mean results with differences in acuity ranging from <0.001 to 0.054 logMAR (0.2-13%). Using mathematically simulated defocus is a viable option if both reasonable accuracy and ease of use are required. The fact that the application of the mathematical model only blurs the stimulus itself, but not the surrounding environment, does not appear to be detrimental to the method. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  17. Use of subjective and objective criteria to categorise visual disability.

    Science.gov (United States)

    Kajla, Garima; Rohatgi, Jolly; Dhaliwal, Upreet

    2014-04-01

    Visual disability is categorised using objective criteria. Subjective measures are not considered. To use subjective criteria along with objective ones to categorise visual disability. Ophthalmology out-patient department; teaching hospital; observational study. Consecutive persons aged >25 years, with vision disability; group-zero: normal range of vision, to group-X: no perception of light, bilaterally. Snellen's vision; binocular contrast sensitivity (Pelli-Robson chart); automated binocular visual field (Humphrey; Esterman test); and vision-related quality of life (Indian Visual Function Questionnaire-33; IND-VFQ33) were recorded. SPSS version-17; Kruskal-wallis test was used to compare contrast sensitivity and visual fields across groups, and Mann-Whitney U test for pair-wise comparison (Bonferroni adjustment; P visual fields were comparable for differing disability grades except when disability was severe (P disability grades but comparable for groups III (78.51 ± 6.86) and IV (82.64 ± 5.80), and groups IV and V (77.23 ± 3.22); these were merged to generate group 345; similarly, global scores were comparable for adjacent groups V and VI (72.53 ± 6.77), VI and VII (74.46 ± 4.32), and VII and VIII (69.12 ± 5.97); these were merged to generate group 5678; thereafter, contrast sensitivity and global and individual IND-VFQ33 scores could differentiate between different grades of disability in the five new groups. Subjective criteria made it possible to objectively reclassify visual disability. Visual disability grades could be redefined to accommodate all from zero-100%.

  18. Remaining visual field and preserved subjective visual functioning prevent mental distress in patients with visual field defects

    Directory of Open Access Journals (Sweden)

    Carolin eGall

    2013-09-01

    Full Text Available Background: Patients with visual field defects after visual pathway lesion may experience reduced vision-related quality of life (vrQoL. It has not been clarified how vrQoL impairments contribute to vision-related mental distress.Methods: 108 subjects with visual field defects caused by optic neuropathies (age M=57.6; SD=13.7 years answered the National Eye Institute Visual-Functioning Questionnaire (NEI-VFQ for vrQoL and the SF-12 Short Form Health Survey for health-related quality of life (hrQoL. A ten item composite of NEI-VFQ visual functioning and five items of mental health symptoms due to vision problems were subjected to Rasch analysis. The test battery comprised static and High Resolution Perimetry (HRP. Regression and path analysis were used to investigate associations between QoL, mental distress and perimetry results.Results: A higher level of visual functioning was associated with monocular impairment and a larger remaining visual field compared to binocular impairment. Subjective visual functioning but not visual field parameters predicted mental health symptoms due to vision problems which was the only variable associated with the SF-12 mental component score. The SF-12 physical component score was less strongly associated with mental health symptoms due to vision problems. Here, reaction time in HRP and mean threshold in perimetry were additional significant variables. Path analysis revealed a significant path of remaining visual field via visual functioning on mental health. Conclusions: Subjective consequences of visual impairments in everyday life impact mental health rather than objective visual function loss as measured by perimetry. Since a higher extent of vrQoL was related to lower levels of mental distress, the maintenance of vrQoL could reduce and prevent mental distress due to vision problems. Patients with persisting visual field defects may benefit from neuropsychological rehabilitation and supportive therapies.

  19. Predictors of stereoacuity outcome in visually mature subjects with exotropia.

    Science.gov (United States)

    Koç, F; Sefi-Yurdakul, N

    2016-02-01

    The purpose of this study was to determine the predictors of stereoacuity outcome in visually mature subjects with exotropia following surgical correction. Visually mature subjects who were surgically aligned and had been tested for stereoacuity in the postoperative period were studied retrospectively. Subjects were grouped with respect to their responses to Titmus or TNO stereotests. Characteristics such as amblyopia, anisometropia, and characteristics of the exodeviation such as time of onset, duration, intermittency, presence of an A or V pattern, distance-near disparity, coexisting vertical deviation, and inferior oblique overaction, were compared between the groups. One hundred and four visually mature subjects with exotropia met the inclusion criteria. Stereoacuity was achieved in 77% of the study group and only 9% of these could achieve fine stereoacuity. Negative stereoacuity was more frequently associated with larger deviation angles, higher anisometropia, inferior oblique overaction, pattern strabismus, coexisting vertical strabismus, and distance-near disparity, but not at a statistically significant level. The optimal cutoff for strabismus duration was 20 years for a positive stereoacuity outcome. Any-level visual acuity difference was found to decrease the chance for positive stereoacuity significantly. The odds ratios for the stereoacuity positivity were 4.05 for strabismus duration 1 year of age, 3.79 for weaker eye visual acuity >20/25 and 9.85 for intermittency of strabismus. Intermittence of exotropia was the strongest predictor for positive stereoacuity. Exotropia onset after 1 year of age, absence of any-level visual acuity difference, and strabismus duration <20 years were the other predictors with decreasing power.

  20. Subjective visual vertical after treatment of benign paroxysmal positional vertigo.

    Science.gov (United States)

    Ferreira, Maristela Mian; Ganança, Maurício Malavasi; Caovilla, Heloisa Helena

    Otolith function can be studied by testing the subjective visual vertical, because the tilt of the vertical line beyond the normal range is a sign of vestibular dysfunction. Benign paroxysmal positional vertigo is a disorder of one or more labyrinthine semicircular canals caused by fractions of otoliths derived from the utricular macula. To compare the subjective visual vertical with the bucket test before and immediately after the particle repositioning maneuver in patients with benign paroxysmal positional vertigo. We evaluated 20 patients. The estimated position where a fluorescent line within a bucket reached the vertical position was measured before and immediately after the particle repositioning maneuver. Data were tabulated and statistically analyzed. Before repositioning maneuver, 9 patients (45.0%) had absolute values of the subjective visual vertical above the reference standard and 2 (10.0%) after the maneuver; the mean of the absolute values of the vertical deviation was significantly lower after the intervention (pbenign paroxysmal positional vertigo. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  1. Visual Information Presentation in Continuous Control Systems using Visual Enhancements

    OpenAIRE

    Park, Jaekyu; Park, Sung Ha

    2008-01-01

    This chapter was intended to identify and quantify the effects of visual enhancement cues on the performance of continuous control tasks such as tracking tasks. Also, we investigated the types and utilities of visual enhancements as visual aids that improve a performance and offer spatial information. Especially, we have indentified that various visual enhancements improve not only a performance but also the possibility of an error through a case study. The findings of this chapter are applic...

  2. Influence of hemianopic visual field loss on visual motor control.

    Directory of Open Access Journals (Sweden)

    Diederick C Niehorster

    Full Text Available Homonymous hemianopia (HH is an anisotropic visual impairment characterized by the binocular inability to see one side of the visual field. Patients with HH often misperceive visual space. Here we investigated how HH affects visual motor control.Seven patients with complete HH and no neglect or cognitive decline and seven gender- and age-matched controls viewed displays in which a target moved randomly along the horizontal or the vertical axis. They used a joystick to control the target movement to keep it at the center of the screen. We found that the mean deviation of the target position from the center of the screen along the horizontal axis was biased toward the blind side for five out of seven HH patients. More importantly, while the normal vision controls showed more precise control and larger response amplitudes when the target moved along the horizontal rather than the vertical axis, the control performance of the HH patients was not different between these two target motion experimental conditions.Compared with normal vision controls, HH affected patients' control performance when the target moved horizontally (i.e., along the axis of their visual impairment rather than vertically. We conclude that hemianopia affects the use of visual information for online control of a moving target specific to the axis of visual impairment. The implications of the findings for driving in hemianopic patients are discussed.

  3. Electromyographic and neuromuscular variables in unstable postpolio subjects, stable postpolio subjects, and control subjects.

    Science.gov (United States)

    Rodriquez, A A; Agre, J C; Franke, T M

    1997-09-01

    To compare strength and endurance variables obtained in the quadriceps muscles of postpolio and control subjects over a 7-year interval with macro and single fiber electromyography (EMG) variables. A controlled inception cohort study. Neuromuscular research laboratory of a university hospital. A cohort of 23 postpolio and 14 control subjects. All postpolio subjects had a history, physical examination, and EMG consistent with previous poliomyelitis, and had greater than antigravity strength in the quadriceps muscle tested. Unstable postpolio subjects acknowledged new quadriceps weakness over the 7-year period of the study (n = 11), and stable postpolio subjects denied new weakness of the quadriceps over the same period (n = 12). All subjects had tests of neuromuscular function of the quadriceps muscles at the onset of this study and yearly over a 7-year period. EMG variables were determined on a separate day after the seventh year of neuromuscular measurements. Neuromuscular variables measured were isometric knee extension peak torque, isometric endurance (time to inability to maintain knee extensor contraction at 40% of maximal torque), tension time index (TTI) (product of isometric endurance time and 40% of maximal torque), and recovery of torque at 10 minutes after the endurance test. EMG variables were macro EMG and single fiber EMG (jitter, fiber density, and percent blocking). Unstable postpolio subjects did not lose strength more rapidly than stable postpolio subjects or control subjects. Unstable postpolio subjects were significantly weaker, had decreased TTI, larger macro EMG amplitude, greater jitter, blocking, and fiber density in comparison with stable postpolio subjects (all p postpolio group (p .05) with neuromuscular or EMG variables in control, stable, or unstable postpolio subjects.

  4. Cloud-based Networked Visual Servo Control

    DEFF Research Database (Denmark)

    Wu, Haiyan; Lu, Lei; Chen, Chih-Chung

    2013-01-01

    feedback, ii) a stabilizing control law for the networked visual servo control system with time-varying feedback time delay, and iii) a sending rate scheduling strategy aiming at reducing the communication network load. The performance of the networked visual servo control system with sending rate......The performance of vision-based control systems, in particular of highly dynamic vision-based motion control systems, is often limited by the low sampling rate of the visual feedback caused by the long image processing time. In order to overcome this problem, the networked visual servo control......, which integrates networked computational resources for cloud image processing, is considered in this article. The main contributions of this article are i) a real-time transport protocol for transmitting large volume image data on a cloud computing platform, which enables high sampling rate visual...

  5. Rapid Eye Movements (REMs) and visual dream recall in both congenitally blind and sighted subjects

    Science.gov (United States)

    Bértolo, Helder; Mestre, Tiago; Barrio, Ana; Antona, Beatriz

    2017-08-01

    Our objective was to evaluate rapid eye movements (REMs) associated with visual dream recall in sighted subjects and congenital blind. During two consecutive nights polysomnographic recordings were performed at subjects home. REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way ANOVA and a post-hoc Fisher test (for the features diagnosis (blind vs. sighted) and dream recall (yes or no) as a function of time). The average of REM awakenings per subject and the recall ability were identical in both groups. CB had a lower REM density than CS; the same applied to REM bursts and isolated eye movements. In the two-way ANOVA, REM bursts and REM density were significantly different for positive dream recall, mainly for the CB group and for diagnosis; furthermore for both features significant results were obtained for the interaction of time, recall and diagnosis; the interaction of recall and time was however, stronger. In line with previous findings the data show that blind have lower REMs density. However the ability of dream recall in congenitally blind and sighted controls is identical. In both groups visual dream recall is associated with an increase in REM bursts and density. REM bursts also show differences in the temporal profile. REM visual dream recall is associated with increased REMs activity.

  6. Visual Attention and Saccadic Oculomotor Control in Parkinson's Disease.

    Science.gov (United States)

    Buhmann, Carsten; Kraft, Stefanie; Hinkelmann, Kim; Krause, Sven; Gerloff, Christian; Zangemeister, Wolfgang H

    2015-01-01

    In patients with Parkinson's disease (PD) we aimed at differentiating the relation between selective visual attention, deficits of programming and dynamics of saccadic eye movements while searching for a target and hand-reaction time as well as hand-movement time. Visual attention is crucial for concentrating selectively on one aspect of the visual field while ignoring other aspects. Eye movements are anatomically and functionally related to mechanisms of visual attention. Saccadic dysfunction might confound selective visual attention in PD. We studied visual selective attention in 22 medicated PD patients (clinical ON status, mild to moderate disease severity) and 22 age matched controls. We looked for possible interferences through oculomotor deficits. Two tasks were compared: free viewing of photographs and time optimal visual search of a hidden target. Visual search times (VST), task related dynamics of saccades, and hand-reaction and hand-movement times were analyzed. In the free viewing task mild to moderately affected PD patients did not differ statistically from healthy subjects with respect to saccade dynamics. However, patients differed significantly from healthy subjects in the time optimal visual search task with 25% lower rates of successful searches. Hand movement reaction time did not differ in both groups, whereas hand movement execution time was significantly prolonged in PD patients. Saccadic oculomotor control and hand movement reaction times were intact, whereas in our less severely affected treated PD patients, visual selective attention was not. The highly reduced successful search rate might be related to disturbed programming and delayed execution of saccades during time optimal visual search due to decreased execution of serial-order sequential generation of saccades. © 2015 S. Karger AG, Basel.

  7. Training Visual Control in Wheelchair Basketball Shooting

    Science.gov (United States)

    Oudejans, Raoul R. D.; Heubers, Sjoerd; Ruitenbeek, Jean-Rene J. A. C.; Janssen, Thomas W. J.

    2012-01-01

    We examined the effects of visual control training on expert wheelchair basketball shooting, a skill more difficult than in regular basketball, as players shoot from a seated position to the same rim height. The training consisted of shooting with a visual constraint that forced participants to use target information as late as possible.…

  8. Training visual control in wheelchair basketball shooting

    NARCIS (Netherlands)

    Oudejans, R.R.D.; Heubers, S.; Ruitenbeek, J-R.J.A.C.; Janssen, T.W.J.

    2012-01-01

    We examined the effects of visual control training on expert wheelchair basketball shooting, a skill more difficult than in regular basketball, as players shoot from a seated position to the same rim height. The training consisted of shooting with a visual constraint that forced participants to use

  9. Visual imaging capacity and imagery control in Fine Arts students.

    Science.gov (United States)

    Pérez-Fabello, Maria José; Campos, Alfredo; Gómez-Juncal, Rocío

    2007-06-01

    This study investigated relationships between visual imaging abilities (imaging capacity and imagery control) and academic performance in 146 Fine Arts students (31 men, 115 women). Mean age was 22.3 yr. (SD= 1.9; range 20-26 yr.). All of the participants who volunteered for the experiment regularly attended classes and were first, second, or third year students. For evaluation of imaging abilities, the Spanish versions of the Gordon Test of Visual Imagery Control, the Vividness of Visual Imagery Questionnaire, the Verbalizer-Visualizer Questionnaire, and Betts' Questionnaire Upon Mental Imagery were used. Academic performance was assessed in four areas, Drawing, Painting, Sculpture, and Complementary Subjects, over a three-year period. The results indicate that imagery control was associated with academic performance in Fine Arts. These findings are discussed in the context of previous studies, and new lines of research are proposed.

  10. Patients' subjective visual experiences during vitreous surgery under local anesthesia.

    Science.gov (United States)

    Yu, Ji-Feng; Liang, Li; Wen, Yu-Qin; Liu, Li; Huang, Yi-Fei

    2011-01-01

    To investigate patient's visual experience during vitreous surgery under local anesthesia. A prospective and randomized study of 76 patients that underwent vitreous surgeries in our hospital between July 2010 and December 2010 was designed. All patients were interviewed half an hour before and within 1 hour after the surgery using a standardized questionnaire. Basic characteristics of patients and their intraoperative visual experiences like light, color, moving object, pain, fear, and the desire for general anesthesia before and after the surgery were recorded. Sixty patients (78.9%) perceived at least light perception, and 16 patients (21.1%) got no light perception throughout the entire duration of the operation. Forty one patients (53.9%) perceived only light, while 19 patients (25%) experienced moving objects. Thirty nine patients (51.3%) were frightened during their intraoperative visual experiences. Patients with better preoperative best-corrected visual acuity (BCVA) were more likely to be frightened (p=0.002). The frightened experience was affected notably by the different perceptions during operation, moving object (p=0.024), light (p=0.071), and color (p=0.071). Patients below 50 years old, especially from 20 to 30, were more likely to choose general anesthesia after the vitreous surgery. Most patients (78.9%) experienced at least light perception during the vitreous surgery under local anesthesia. There were no significant differences between the various visual experiences and their basic characteristics. Patients with better preoperative BCVA, perceived moving objects in their visual sensations seemed more likely to be frightened.

  11. The Impact of Cataract Surgery on Subjective Visual Functions and ...

    African Journals Online (AJOL)

    2016-12-13

    Dec 13, 2016 ... Purpose: To determine the impact of cataract surgery on visual functions (VFs) and quality of life (QoL) in patients with cataract at the. National Eye Center, Kaduna. Methods: VFs and QoL questionnaires were administered to the patients preoperatively and 6 weeks postoperatively. Correlation was ...

  12. The Impact of Cataract Surgery on Subjective Visual Functions and ...

    African Journals Online (AJOL)

    Purpose: To determine the impact of cataract surgery on visual functions (VFs) and quality of life (QoL) in patients with cataract at the National Eye Center, Kaduna. Methods: VFs and QoL questionnaires were administered to the patients preoperatively and 6 weeks postoperatively. Correlation was assessed among ...

  13. Hydrogel Inlay for Presbyopia: Objective and Subjective Visual Outcomes.

    Science.gov (United States)

    Yoo, Aeri; Kim, Jae Yong; Kim, Myoung Joon; Tchah, Hungwon

    2015-07-01

    To evaluate changes in visual performance and ocular optical quality after implantation of a corneal hydrogel inlay as a treatment for presbyopia. A Raindrop Near Vision Inlay (ReVision Optics, Lake Forest, CA) was implanted monocularly on the stromal bed of a femtosecond laser-assisted generated corneal flap of non-dominant eyes of 22 patients with emmetropic presbyopia (preoperative spherical equivalent range: -0.50 to 1.00 diopters). Efficacy was determined by measuring near and distance visual acuities and ocular aberrations, and satisfaction was assessed by a patient questionnaire. The preoperative monocular uncorrected near visual acuity of the inlay inserted eye was 20/129 ± 1 Snellen (range: 20/135 to 20/61 Snellen) and improved to 20/35 ± 2 Snellen (range: 20/61 to 20/20 Snellen) (P presbyopia with only moderate effect on visual quality. However, the satisfaction with this therapy was relatively lower in these Korean patients than that reported previously in Western patients. Copyright 2015, SLACK Incorporated.

  14. The Problem of Subject Access to Visual Materials

    Directory of Open Access Journals (Sweden)

    Heather P. Jespersen

    2004-09-01

    Full Text Available This article discusses the problem of giving subject access to works of art. We survey both concept-based and content-based access by computers and by indexers/catalogers respectively, as well as issues of interoperability, database and indexer consistency, and cataloging standards. The authors, both of whom are trained art historians, question attempts to mystify fine art subject matter by the creation of clever library science systems that are executed by the naive. Only when trained art historians and knowledgeable catalogers are finally responsible for providing subject access to works of art, will true interoperability and consistency happen.

  15. Visual bias in subjective assessments of automotive sounds

    DEFF Research Database (Denmark)

    Ellermeier, Wolfgang; Legarth, Søren Vase

    2006-01-01

    In order to evaluate how strong the influence of visual input on sound quality evaluation may be, a naive sample of 20 participants was asked to judge interior automotive sound recordings while simultaneously being exposed to pictures of cars. twenty-two recordings of second-gear acceleration...... accounted for by the pictures was roughly one fifth of the variance due to the sounds themselves. In physical terms, the picture manipulation shifted ratings of powerfulness by what a change in overall sound-pressure level of approximately 2-3 decibels would accomplish....

  16. Using visual stimuli to enhance gait control.

    Science.gov (United States)

    Rhea, Christopher K; Kuznetsov, Nikita A

    2017-01-01

    Gait control challenges commonly coincide with vestibular dysfunction and there is a long history in using balance and gait activities to enhance functional mobility in this population. While much has been learned using traditional rehabilitation exercises, there is a new line of research emerging that is using visual stimuli in a very specific way to enhance gait control. For example, avatars can be created in an individualized manner to incorporate specific gait characteristics. The avatar could then be used as a visual stimulus to which the patient can synchronize their own gait cycle. This line of research builds upon the rich history of sensorimotor control research in which augmented sensory information (visual, haptic, or auditory) is used to probe, and even enhance, human motor control. This review paper focuses on gait control challenges in patients with vestibular dysfunction, provides a brief historical perspective on how various visual displays have been used to probe sensorimotor and gait control, and offers some recommendations for future research.

  17. Subjective Perceptual Distortions and Visual Dysfunction in Children with Autism

    Science.gov (United States)

    Davis, Rebecca A. O.; Bockbrader, Marcia A.; Murphy, Robin R.; Hetrick, William P.; O'Donnell, Brian F.

    2006-01-01

    Case reports and sensory inventories suggest that autism involves sensory processing anomalies. Behavioral tests indicate impaired motion and normal form perception in autism. The present study used first-person accounts to investigate perceptual anomalies and related subjective to psychophysical measures. Nine high-functioning children with…

  18. Postural control in elderly subjects participating in balance training.

    Science.gov (United States)

    Nagy, Edit; Feher-Kiss, Anna; Barnai, Mária; Domján-Preszner, Andrea; Angyan, Lajos; Horvath, Gyöngyi

    2007-05-01

    The changes in postural control in elderly people after an 8-week training course were characterized. Static postural stability was measured during standing on a single force platform first with the eyes open and then with the eyes closed. Body sway was analysed on a force plate in groups of elderly and of young subjects. Half of the elderly subjects then took part in the training course. The posturographic measurements were repeated after the course. The sway in anteroposterior (AP) and mediolateral (ML) directions was subjected to spectral analysis. The frequency spectrum of the platform oscillations was calculated by fast Fourier transformation in the intervals 0.1-0.3, 0.3-1 and 1-3 Hz. It was found that the sway path was longer and the frequency power was higher in the elderly group. The training caused a significant improvement in functional performance, but a significantly longer sway path was observed after the training in the ML direction. The frequency analysis revealed a significantly higher power after 8 weeks without visual control in the ML direction in the training group in the low and the middle frequency bands. The results suggest that the participants' balance confidence and the control of ML balance improved in response to the training. The higher ML frequency power exhibited after the training may be indicative of a better balance performance. Thus, the increase in the sway path in this age group did not mean a further impairment of the postural control.

  19. Subjectivity of Time Perception: A Visual Emotional Orchestration

    Directory of Open Access Journals (Sweden)

    Anna eLambrechts

    2011-11-01

    Full Text Available The aim of the present study was to examine how visual emotional content could orchestrate time perception. The experimental design allowed us to single out the share of emotion in the specific processing of content-bearing pictures, i.e. real-life scenes. Two groups of participants had to reproduce the duration (2, 4 or 6s of content-deprived stimuli (grey squares or differentially valenced content-bearing stimuli, which included neutral, pleasant and unpleasant pictures (IAPS. Results showed that the effect of content differed according to duration: for 2s, the reproduced duration was longer for content-bearing than content-deprived stimuli, but the difference between the two types of stimuli decreased as duration increased and was not significant for the longest duration (6s. For 4s, emotional (pleasant and unpleasant stimuli were judged longer than neutral pictures. Furthermore, whatever the duration, the precision of the reproduction was greater for non-emotional than emotional stimuli (pleasant and unpleasant. These results suggest a dissociation within content effect on timing: relative overestimation of all content-bearing pictures limited to short durations (2s, and delayed overestimation of emotional relative to neutral pictures at 4s, as well as a lesser precision in the temporal judgment of emotional pictures whatever the duration. The angle of emotion processing in time perception allows us to discuss a few theoretical models proposed in the timing literature.

  20. Unbounded evidence accumulation characterizes subjective visual vertical forced-choice perceptual choice and confidence.

    Science.gov (United States)

    Lim, Koeun; Wang, Wei; Merfeld, Daniel M

    2017-11-01

    Humans can subjectively yet quantitatively assess choice confidence based on perceptual precision even when a perceptual decision is made without an immediate reward or feedback. However, surprisingly little is known about choice confidence. Here we investigate the dynamics of choice confidence by merging two parallel conceptual frameworks of decision making, signal detection theory and sequential analyses (i.e., drift-diffusion modeling). Specifically, to capture end-point statistics of binary choice and confidence, we built on a previous study that defined choice confidence in terms of psychophysics derived from signal detection theory. At the same time, we augmented this mathematical model to include accumulator dynamics of a drift-diffusion model to characterize the time dependence of the choice behaviors in a standard forced-choice paradigm in which stimulus duration is controlled by the operator. Human subjects performed a subjective visual vertical task, simultaneously reporting binary orientation choice and probabilistic confidence. Both binary choice and confidence experimental data displayed statistics and dynamics consistent with both signal detection theory and evidence accumulation, respectively. Specifically, the computational simulations showed that the unbounded evidence accumulator model fits the confidence data better than the classical bounded model, while bounded and unbounded models were indistinguishable for binary choice data. These results suggest that the brain can utilize mechanisms consistent with signal detection theory-especially when judging confidence without time pressure.NEW & NOTEWORTHY We found that choice confidence data show dynamics consistent with evidence accumulation for a forced-choice subjective visual vertical task. We also found that the evidence accumulation appeared unbounded when judging confidence, which suggests that the brain utilizes mechanisms consistent with signal detection theory to determine choice confidence

  1. Visual cues for manual control of headway.

    Science.gov (United States)

    Hosking, Simon G; Davey, Catherine E; Kaiser, Mary K

    2013-01-01

    The ability to maintain appropriate gaps to objects in one's environment is important when navigating through a three-dimensional world. Previous research has shown that the visual angle subtended by a lead/approaching object and its rate of change are important variables for timing interceptions, collision avoidance, continuous regulation of braking, and manual control of headway. However, investigations of headway maintenance have required participants to maintain a fixed distance headway and have not investigated how information about own-speed is taken into account. In the following experiment, we asked participants to use a joystick to follow computer-simulated lead objects. The results showed that ground texture, following speed, and the size of the lead object had significant effects on both mean following distances and following distance variance. Furthermore, models of the participants' joystick responses provided better fits when it was assumed that the desired visual extent of the lead object would vary over time. Taken together, the results indicate that while information about own-speed is used by controllers to set the desired headway to a lead object, the continuous regulation of headway is influenced primarily by the visual angle of the lead object and its rate of change. The reliance on visual angle, its rate of change, and/or own-speed information also varied depending on the control dynamics of the system. Such findings are consistent with an optimal control criterion that reflects a differential weighting on different sources of information depending on the plant dynamics. As in other judgements of motion in depth, the information used for controlling headway to other objects in the environment varies depending on the constraints of the task and different strategies of control.

  2. Relationship between macular pigment and visual function in subjects with early age-related macular degeneration.

    Science.gov (United States)

    Akuffo, Kwadwo Owusu; Nolan, John M; Peto, Tunde; Stack, Jim; Leung, Irene; Corcoran, Laura; Beatty, Stephen

    2017-02-01

    To investigate the relationship between macular pigment (MP) and visual function in subjects with early age-related macular degeneration (AMD). 121 subjects with early AMD enrolled as part of the Central Retinal Enrichment Supplementation Trial (CREST; ISRCTN13894787) were assessed using a range of psychophysical measures of visual function, including best corrected visual acuity (BCVA), letter contrast sensitivity (CS), mesopic and photopic CS, mesopic and photopic glare disability (GD), photostress recovery time (PRT), reading performance and subjective visual function, using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). MP was measured using customised heterochromatic flicker photometry. Letter CS, mesopic and photopic CS, photopic GD and mean reading speed were each significantly (p0.05, for all). MP relates positively to many measures of visual function in unsupplemented subjects with early AMD. The CREST trial will investigate whether enrichment of MP influences visual function among those afflicted with this condition. ISRCTN13894787. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. Relationship between macular pigment and visual function in subjects with early age-related macular degeneration

    Science.gov (United States)

    Nolan, John M; Peto, Tunde; Stack, Jim; Leung, Irene; Corcoran, Laura; Beatty, Stephen

    2017-01-01

    Purpose To investigate the relationship between macular pigment (MP) and visual function in subjects with early age-related macular degeneration (AMD). Methods 121 subjects with early AMD enrolled as part of the Central Retinal Enrichment Supplementation Trial (CREST; ISRCTN13894787) were assessed using a range of psychophysical measures of visual function, including best corrected visual acuity (BCVA), letter contrast sensitivity (CS), mesopic and photopic CS, mesopic and photopic glare disability (GD), photostress recovery time (PRT), reading performance and subjective visual function, using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). MP was measured using customised heterochromatic flicker photometry. Results Letter CS, mesopic and photopic CS, photopic GD and mean reading speed were each significantly (p0.05, for all). Conclusions MP relates positively to many measures of visual function in unsupplemented subjects with early AMD. The CREST trial will investigate whether enrichment of MP influences visual function among those afflicted with this condition. Trial registration number ISRCTN13894787. PMID:27091854

  4. Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction?

    Science.gov (United States)

    Hastings, Gareth D; Marsack, Jason D; Nguyen, Lan Chi; Cheng, Han; Applegate, Raymond A

    2017-05-01

    To prospectively examine whether using the visual image quality metric, visual Strehl (VSX), to optimise objective refraction from wavefront error measurements can provide equivalent or better visual performance than subjective refraction and which refraction is preferred in free viewing. Subjective refractions and wavefront aberrations were measured on 40 visually-normal eyes of 20 subjects, through natural and dilated pupils. For each eye a sphere, cylinder, and axis prescription was also objectively determined that optimised visual image quality (VSX) for the measured wavefront error. High contrast (HC) and low contrast (LC) logMAR visual acuity (VA) and short-term monocular distance vision preference were recorded and compared between the VSX-objective and subjective prescriptions both undilated and dilated. For 36 myopic eyes, clinically equivalent (and not statistically different) HC VA was provided with both the objective and subjective refractions (undilated mean ± S.D. was -0.06 ± 0.04 with both refractions; dilated was -0.05 ± 0.04 with the objective, and -0.05 ± 0.05 with the subjective refraction). LC logMAR VA provided by the objective refraction was also clinically equivalent and not statistically different to that provided by the subjective refraction through both natural and dilated pupils for myopic eyes. In free viewing the objective prescription was preferred over the subjective by 72% of myopic eyes when not dilated. For four habitually undercorrected high hyperopic eyes, the VSX-objective refraction was more positive in spherical power and VA poorer than with the subjective refraction. A method of simultaneously optimising sphere, cylinder, and axis from wavefront error measurements, using the visual image quality metric VSX, is described. In myopic subjects, visual performance, as measured by HC and LC VA, with this VSX-objective refraction was found equivalent to that provided by subjective refraction, and was typically preferred

  5. Visual Images of Subjective Perception of Time in a Literary Text

    Science.gov (United States)

    Nesterik, Ella V.; Issina, Gaukhar I.; Pecherskikh, Taliya F.; Belikova, Oxana V.

    2016-01-01

    The article is devoted to the subjective perception of time, or psychological time, as a text category and a literary image. It focuses on the visual images that are characteristic of different types of literary time--accelerated, decelerated and frozen (vanished). The research is based on the assumption that the category of subjective perception…

  6. Visual P3a in male subjects at high risk for alcoholism.

    Science.gov (United States)

    Rodríguez Holguín, S; Porjesz, B; Chorlian, D B; Polich, J; Begleiter, H

    1999-07-15

    Voltage of the P300 component of event-related potentials (ERPs) has been proposed as a phenotypic marker of risk for alcoholism. P3a elicited by intrusive events is important in the context of deficits in inhibition found during psychophysiological and behavioral evaluations in children of alcoholics. ERPs were recorded from a group of adult children of alcoholics (n = 26) and controls (n = 23) with a three-stimulus visual oddball paradigm. The task required a difficult perceptual discrimination between a frequent (.80) vertical line and an infrequent (.10) 2 degrees tilted line (target). An easily discriminable nontarget infrequent horizontal line also occurred (.10). Subjects were required to press a button to the target. P3a was compared using mixed-model ANCOVAs at 31 sites organized in 5 scalp regions. Current source density (CSD) maps were also analyzed. High-risk (HR) subjects manifested reduced P3a amplitudes compared to controls at frontal, central, parietal, and temporal electrodes. CSD analyses supported these findings with group differences found for all the scalp regions. The results are discussed in relation to previous HR studies. P3a reductions may be related to deficits in neuronal inhibition during stimulus processing. These results suggest that P3a amplitude may be important as a marker for vulnerability to alcoholism.

  7. Visual Control for Multirobot Organized Rendezvous.

    Science.gov (United States)

    Lopez-Nicolas, G; Aranda, M; Mezouar, Y; Sagues, C

    2012-08-01

    This paper addresses the problem of visual control of a set of mobile robots. In our framework, the perception system consists of an uncalibrated flying camera performing an unknown general motion. The robots are assumed to undergo planar motion considering nonholonomic constraints. The goal of the control task is to drive the multirobot system to a desired rendezvous configuration relying solely on visual information given by the flying camera. The desired multirobot configuration is defined with an image of the set of robots in that configuration without any additional information. We propose a homography-based framework relying on the homography induced by the multirobot system that gives a desired homography to be used to define the reference target, and a new image-based control law that drives the robots to the desired configuration by imposing a rigidity constraint. This paper extends our previous work, and the main contributions are that the motion constraints on the flying camera are removed, the control law is improved by reducing the number of required steps, the stability of the new control law is proved, and real experiments are provided to validate the proposal.

  8. Subjective visual vertical perception and sense of smell in Parkinson disease.

    Science.gov (United States)

    Khattab, Ahmed; Docherty, Sharon; Bagust, Jeff; Willington, Robert; Thomas, Peter; Amar, Khaled

    2012-01-01

    This article describes an open cross-sectional observational study involving 47 participants with Parkinson disease (PD) and 47 (age- and sex-matched) nondisabled controls without PD. The aim was to determine the profiles of subjective visual vertical (SVV) perception and sense of smell perception in both groups. There was a statistically significant difference (p smell test performance. Controls were more likely to correctly identify odors, with a median score of 10 out of 12 compared with 6.5 out of 12 for patients with PD. The median SVV error for the PD group when the frame was untilted was 0.75 degrees compared with 0.50 degrees for controls. This difference was statistically significant (p = 0.02). When the frame was tilted, the median SVV error for the PD group was 2.31 degrees compared with 2.00 degrees for controls (not statistically significant), with both groups showing similar distribution pattern of errors. There was no statistical correlation between number of correctly identified odors and an individual's SVV error. However, a statistically significant negative correlation (r = -0.45, p = 0.01) was found between Mini-Mental State Examination score and mean time taken to complete each rod and frame test in patients with PD, suggesting that SVV errors might be more correlated with cognitive function than with loss of sense of smell.

  9. Exploiting major trends in subject hierarchies for large-scale collection visualization

    Science.gov (United States)

    Julien, Charles-Antoine; Tirilly, Pierre; Leide, John E.; Guastavino, Catherine

    2012-01-01

    Many large digital collections are currently organized by subject; however, these useful information organization structures are large and complex, making them difficult to browse. Current online tools and visualization prototypes show small localized subsets and do not provide the ability to explore the predominant patterns of the overall subject structure. This research addresses this issue by simplifying the subject structure using two techniques based on the highly uneven distribution of real-world collections: level compression and child pruning. The approach is demonstrated using a sample of 130K records organized by the Library of Congress Subject Headings (LCSH). Promising results show that the subject hierarchy can be reduced down to 42% of its initial size, while maintaining access to 81% of the collection. The visual impact is demonstrated using a traditional outline view allowing searchers to dynamically change the amount of complexity that they feel necessary for the tasks at hand.

  10. Empirical Analysis of the Subjective Impressions and Objective Measures of Domain Scientists’ Analytical Judgment Using Visualizations

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Aritra; Burrows, Susannah M.; Han, Kyungsik; Rasch, Philip J.

    2017-04-15

    Scientists working in a particular domain often adhere to conventional data analysis and presentation methods and this leads to familiarity with these methods over time. But does high familiarity always lead to better analytical judgment? This question is especially relevant when visualizations are used in scientific tasks, as there can be discrepancies between visualization best practices and domain conventions. However, there is little empirical evidence of the relationships between scientists’ subjective impressions about familiar and unfamiliar visualizations and objective measures of their effect on scientific judgment. To address this gap and to study these factors, we focus on the climate science domain, specifically on visualizations used for comparison of model performance. We present a comprehensive user study with 47 climate scientists where we explored the following factors: i) relationships between scientists’ familiarity, their perceived levels of com- fort, confidence, accuracy, and objective measures of accuracy, and ii) relationships among domain experience, visualization familiarity, and post-study preference.

  11. Neurocardiological differences between musicians and control subjects.

    Science.gov (United States)

    Burggraaf, J L I; Elffers, T W; Segeth, F M; Austie, F M C; Plug, M B; Gademan, M G J; Maan, A C; Man, S; de Muynck, M; Soekkha, T; Simonsz, A; van der Wall, E E; Schalij, M J; Swenne, C A

    2013-04-01

    Exercise training is beneficial in health and disease. Part of the training effect materialises in the brainstem due to the exercise-associated somatosensory nerve traffic. Because active music making also involves somatosensory nerve traffic, we hypothesised that this will have training effects resembling those of physical exercise. We compared two groups of healthy, young subjects between 18 and 30 years: 25 music students (13/12 male/female, group M) and 28 controls (12/16 male/female, group C), peers, who were non-musicians. Measurement sessions to determine resting heart rate, resting blood pressure and baroreflex sensitivity (BRS) were held during morning hours. Groups M and C did not differ significantly in age (21.4 ± 3.0 vs 21.2 ± 3.1 years), height (1.79 ± 0.11 vs 1.77 ± 0.10 m), weight (68.0 ± 9.1 vs 66.8 ± 10.4 kg), body mass index (21.2 ± 2.5 vs 21.3 ± 2.4 kg∙m(-2)) and physical exercise volume (39.3 ± 38.8 vs 36.6 ± 23.6 metabolic equivalent hours/week). Group M practised music daily for 1.8 ± 0.7 h. In group M heart rate (65.1 ± 10.6 vs 68.8 ± 8.3 beats/min, trend P =0.08), systolic blood pressure (114.2 ± 8.7 vs 120.3 ± 10.0 mmHg, P = 0.01), diastolic blood pressure (65.0 ± 6.1 vs 71.0 ± 6.2 mmHg, P active music making has training effects resembling those of physical exercise training. Our study opens a new perspective, in which active music making, additionally to being an artistic activity, renders concrete health benefits for the musician.

  12. Rapid Eye Movements (REMs) and visual dream recall in both congenitally blind and sighted subjects

    OpenAIRE

    Bértolo, Helder; Mestre, Tiago; Barrio de Santos, Ana Rosa; Antona Peñalba, Beatriz

    2017-01-01

    Our objective was to evaluate rapid eye movements (REMs) associated with visual dream recall in sighted subjects and congenital blind. During two consecutive nights polysomnographic recordings were performed at subjects home. REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way ANOVA and...

  13. Visual BOLD Response in Late Blind Subjects with Argus II Retinal Prosthesis.

    Directory of Open Access Journals (Sweden)

    E Castaldi

    2016-10-01

    Full Text Available Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI. After surgery, six out of seven retinitis pigmentosa (RP blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them. No subject showed any improvement of contrast sensitivity in either eye when not using the Argus II. Before the implant, the Blood Oxygenation Level Dependent (BOLD activity in V1 and the lateral geniculate nucleus (LGN was very weak or absent. Surprisingly, after prolonged use of Argus II, BOLD responses to visual input were enhanced. This is, to our knowledge, the first study tracking the neural changes of visual areas in patients after retinal implant, revealing a capacity to respond to restored visual input even after years of deprivation.

  14. Effects of Visual Cortex Activation on the Nociceptive Blink Reflex in Healthy Subjects

    Science.gov (United States)

    Sava, Simona L.; de Pasqua, Victor; Magis, Delphine; Schoenen, Jean

    2014-01-01

    Bright light can cause excessive visual discomfort, referred to as photophobia. The precise mechanisms linking luminance to the trigeminal nociceptive system supposed to mediate this discomfort are not known. To address this issue in healthy human subjects we modulated differentially visual cortex activity by repetitive transcranial magnetic stimulation (rTMS) or flash light stimulation, and studied the effect on supraorbital pain thresholds and the nociceptive-specific blink reflex (nBR). Low frequency rTMS that inhibits the underlying cortex, significantly decreased pain thresholds, increased the 1st nBR block ipsi- and contralaterally and potentiated habituation contralaterally. After high frequency or sham rTMS over the visual cortex, and rMS over the right greater occipital nerve we found no significant change. By contrast, excitatory flash light stimulation increased pain thresholds, decreased the 1st nBR block of ipsi- and contralaterally and increased habituation contralaterally. Our data demonstrate in healthy subjects a functional relation between the visual cortex and the trigeminal nociceptive system, as assessed by the nociceptive blink reflex. The results argue in favour of a top-down inhibitory pathway from the visual areas to trigemino-cervical nociceptors. We postulate that in normal conditions this visuo-trigeminal inhibitory pathway may avoid disturbance of vision by too frequent blinking and that hypoactivity of the visual cortex for pathological reasons may promote headache and photophobia. PMID:24936654

  15. Subjective visual vertical with the bucket method in Brazilian healthy individuals.

    Science.gov (United States)

    Ferreira, Maristela Mian; Cunha, Fabiana; Ganança, Cristina Freitas; Ganança, Maurício Malavasi; Caovilla, Heloisa Helena

    2016-01-01

    The capacity of a healthy individual to estimate the true vertical in relation to the Earth when a fluorescent line is aligned in a completely dark room is called the subjective visual vertical. To evaluate subjective visual vertical using the bucket method in healthy Brazilian individuals. Binocular subjective visual vertical was measured in 100 healthy volunteers, 50 females and 50 males. The volunteers indicated the estimated position in which a fluorescent line inside a bucket reached the vertical position. A total of ten repetitions were performed, five clockwise and five counterclockwise. Data were tabulated and analyzed statistically. It was observed that the highest concentration of absolute values of vertical deviation was present up to 3°, regardless of gender, and the vertical deviation did not increase with age. The analysis of the mean of the absolute values of deviations from the vertical of 90% of the sample showed a maximum value of 2.6°, and at the analysis of 95%, the maximum value was 3.4° deviation from the vertical. The bucket method is easy to perform and interpret when assessing the deviation of the subjective visual vertical in relation to the true vertical in healthy Brazilian individuals. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  16. Wearing weighted backpack dilates subjective visual duration: The role of functional linkage between weight experience and visual timing

    Directory of Open Access Journals (Sweden)

    Lina eJia

    2015-09-01

    Full Text Available Bodily state plays a critical role in our perception. In the present study, we asked the question whether and how bodily experience of weights influences time perception. Participants judged durations of a picture (a backpack or a trolley bag presented on the screen, while wearing different weight backpacks or without backpack. The results showed that the subjective dura-tion of the backpack picture was dilated when participants wore a medium weighted backpack relative to an empty backpack or without backpack, regardless of identity (e.g., color of the visual backpack. However, the duration dilation was not manifested for the picture of trolley bag. These findings suggest that weight experience modulates visual duration estimation through the linkage between the wore backpack and to-be-estimated visual target. The con-gruent action affordance between the wore backpack and visual inputs plays a critical role in the functional linkage between inner experience and time perception. We interpreted our findings within the framework of embodied time perception.

  17. Relation between food intake and visual analogue scale ratings of appetite and other sensations in healthy older and young subjects.

    Science.gov (United States)

    Parker, B A; Sturm, K; MacIntosh, C G; Feinle, C; Horowitz, M; Chapman, I M

    2004-02-01

    Visual analogue scales are widely used in appetite research, yet the validity of these scales to evaluate appetite and mood has not been assessed in older subjects. The aim of this study was to determine the relations between food intake and visual analogue scale (VAS) ratings of appetite and nonappetite sensations in healthy older and young subjects. Retrospective combined analysis of four single-blind, randomised, controlled appetite studies. All studies were conducted in the University of Adelaide, Department of Medicine, Adelaide, Australia. A total of 45 healthy young men (n=24) and women (n=21) aged 18-35 y and 45 healthy older men (n=24) and women (n=21) aged 65-85 y were recruited by advertisement. Oral, intraduodenal or intravenous administration of treatments which suppressed food intake were compared to control. Up to 90 min after treatment, a test meal was offered and subjects ate freely for between 30 and 60 min. Perceptions were assessed by 100-mm visual analogue scales administered at regular intervals. Food intake at the test meal was positively related to perceptions of hunger, drowsiness, and calmness at both baseline and premeal (r>0.16, P 0.2, P<0.05) in both older and young subjects. Food intake was related to VAS ratings at least as strongly, if not more so, in older as in young subjects. These observations (i) confirm that food intake is related to perceptions of hunger and fullness as assessed by VAS in healthy older and young subjects, and (ii) suggest that sensations, not obviously associated with appetite, including 'drowsiness' and 'calmness', are also associated with food intake.

  18. Avaliação da vertical visual subjetiva em indivíduos brasileiros normais Subjective visual vertical evaluation in normal Brazilian subjects

    Directory of Open Access Journals (Sweden)

    Aline M. Kozoroski Kanashiro

    2007-06-01

    Full Text Available A função otolítica pode ser avaliada pela Vertical Visual Subjetiva (VVS que determina a capacidade de um indivíduo julgar se objetos estão na posição vertical na ausência de outras referências visuais. O objetivo deste estudo foi avaliar a VVS em indivíduos brasileiros normais usando um aparelho portátil. As medidas da VVS foram realizadas em 160 indivíduos (16 a 85 anos. O valor médio da VVS foi obtido após dez ajustes. A VVS teve valores médios entre -2,0º e +2,4º (média=0,18º, e DP=0,77º. Não houve diferença entre as médias da VVS em relação à idade (teste de Kruskal-Wallis; p=0,40, mas as faixas etárias maiores tiveram variância maior (teste de Levene; p=0,016. Os valores da VVS encontrados neste estudo foram semelhantes aos registrados na literatura. Não houve diferença nas médias das inclinações da VVS de acordo com a idade, mas foi encontrada maior variância entre indivíduos mais idosos.Otolith function can be evaluated by subjective visual vertical (SVV that determine the capacity of a subject to judge if the objects are on vertical position with absence of any visual reference. The aim of this study was to evaluate the SVV in a sample of normal Brazilian subjects using a portable device. Measurements of SVV were performed in 160 normal subjects (aged from 16 to 85. SVV mean value was obtained after ten adjustments. SVV mean values ranged from -2.0º to +2.4º (mean=0.18º, and SD=0.77. Considering all age groups, there was no difference of SVV mean values (Kruskal-Wallis test; p=0.40, but older groups had a greater variance (Levene test; p=0.016. SVV values observed in this study are comparable to those described in previous studies. Although there was no difference in mean SVV-inclination according to age, there was a greater variance in older subjects.

  19. Vector model for mapping of visual space to subjective 4-D sphere

    Science.gov (United States)

    Matuzevicius, Dalius; Vaitkevicius, Henrikas

    2014-03-01

    Here we present a mathematical model of binocular vision that maps a visible physical world to a subjective perception of it. The subjective space is a set of 4-D vectors whose components are outputs of four monocular neurons from each of the two eyes. Monocular neurons have one of the four types of concentric receptive fields with Gabor-like weighting coefficients. Next this vector representation of binocular vision is implemented as a pool of neurons where each of them is selective to the object's particular location in a 3-D visual space. Formally each point of the visual space is being projected onto a 4-D sphere. Proposed model allows determination of subjective distances in depth and direction, provides computational means for determination of Panum's area and explains diplopia and allelotropia.

  20. Control of jaw-clenching forces in dentate subjects.

    Science.gov (United States)

    Testa, Marco; Rolando, Mara; Roatta, Silvestro

    2011-01-01

    To characterize the control of jaw-clenching forces by means of a simple force-matching exercise. Seventeen healthy subjects, provided with visual feedback of the exerted force, carried out a unilateral force-matching exercise requiring developing and maintaining for 7 seconds a jaw-clenching force at 10%, 30%, 50%, and 70% of the maximum voluntary contraction. The task was repeated three times in each of two sessions. Motor performance was assessed, for both left and right sides, by different indices quantifying mean distance (MD), offset error (OE), and standard deviation (SD). Their dependence on force intensity, side, and time was assessed by ANOVA. All error indices increased with the intensity of contraction in absolute terms. After normalization with respect to force level, the average performance in the second session was characterized by MD of 8.1% ± 2.6, OE 4.8% ± 2.9, and SD 12.7% ± 6.7 (mean ± standard deviation). Assessment of performance exhibited good reliability for all indices (intraclass correlation coefficient ranging from 74% to 88%). The motor performance improved with repetition (P .05) but was highly correlated between left and right side (P < .01). The adopted approach is adequate to provide for an objective assessment of individual force control, although the presence of a learning phase must be taken into account.

  1. Visual Control of Robots Using Range Images

    Directory of Open Access Journals (Sweden)

    Fernando Torres

    2010-08-01

    Full Text Available In the last years, 3D-vision systems based on the time-of-flight (ToF principle have gained more importance in order to obtain 3D information from the workspace. In this paper, an analysis of the use of 3D ToF cameras to guide a robot arm is performed. To do so, an adaptive method to simultaneous visual servo control and camera calibration is presented. Using this method a robot arm is guided by using range information obtained from a ToF camera. Furthermore, the self-calibration method obtains the adequate integration time to be used by the range camera in order to precisely determine the depth information.

  2. Visual art as means and subject of instruction: Various approaches and strategies

    Directory of Open Access Journals (Sweden)

    Pavlović Marija M.

    2016-01-01

    Full Text Available The paper looks at various approaches and strategies of using visual art in nursery schools and elementary schools in accordance with theory-based concepts of the abilities and interests of children in these age groups. The teaching of younger children which emphasizes gaining experience through creative work and other age-appropriate approaches and strategies helps children learn about the visual arts, but also about content from other subjects of study. On the other hand, with older children the focus shifts to gaining knowledge about art, though this does not exclude creative work as well as the integration of visual arts content with the content of other subjects, thus leading to the achievement of more general educational goals. Therefore, drawing on the relevant literature from educational practice and museum and gallery work, and in accordance with what is known about the developmental competences of nursery age and elementary school age children, this paper aims to promote the adoption of adequate approaches and strategies in teaching, using visual art as the subject or as a means of instruction.

  3. Objective and subjective visual performance of multifocal contact lenses: pilot study.

    Science.gov (United States)

    Vasudevan, Balamurali; Flores, Michael; Gaib, Sara

    2014-06-01

    The aim of the present study was to compare the objective and subjective visual performance of three different soft multifocal contact lenses. 10 subjects (habitual soft contact lens wearers) between the ages of 40 and 45 years participated in the study. Three different multifocal silicone hydrogel contact lenses (Acuvue Oasys, Air Optix and Biofinity) were fit within the same visit. All the lenses were fit according to the manufacturers' recommendation using the respective fitting guide. Visual performance tests included low and high contrast distance and near visual acuity, contrast sensitivity, range of clear vision and through-focus curve. Objective visual performance tests included measurement of open field accommodative response at different defocus levels and optical aberrations at different viewing distances. Accommodative response was not significantly different between the three types of multifocal contact lenses at each of the accommodative stimulus levels (p>0.05). Accommodative lag increased for higher stimulus levels for all 3 types of contact lenses. Ocular aberrations were not significantly different between these 3 contact lens designs at each of the different viewing distances (p>0.05). In addition, optical aberrations did not significantly differ between different viewing distances for any of these lenses (p>0.05). ANOVA revealed no significant difference in high and low contrast distance visual acuity as well as near visual acuity and contrast sensitivity function between the 3 multifocal contact lenses and spectacles (p>0.05). There was no statistically significant difference in accommodative response, optical aberrations or visual performance between the 3 multifocal contact lenses in early presbyopes. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  4. Subjective recovery time after exhausting muscular activity in postpolio and control subjects.

    Science.gov (United States)

    Agre, J C; Rodriquez, A A; Franke, T M

    1998-01-01

    The purpose of this study was to determine whether the time to subjectively fully recover after the performance of exhausting muscular exercise was greater in unstable postpolio as compared with stable postpolio or control subjects. Twenty-five unstable (those complaining of declining muscle strength) postpolio, 16 stable (those denying declining muscle strength) postpolio, and 25 control subjects performed an isometric contraction of the knee extensor (quadriceps femoris) musculature at 40% of maximal torque until they were no longer able to do so. Five-second maximal effort contractions were made every 30 s through 2 min after the time of failure was reached and then at 1-min intervals through 10 min after failure was reached. Subjects reported the duration of time required to subjectively fully recover from this activity. Choices of "less than 1 day," "1 day," "2 days," etc., up to "greater than 2 wk" were given to the subjects for their response. Analysis was by nonparametric ANOVA and appropriate post hoc comparison procedures. Unstable postpolio subjects reported a greater recovery time than either the stable postpolio or control subjects (mean +/- SD of 2.6 +/- 3.0 days, 0.6 +/- 1.0 days, and 0.7 +/- 1.1 days, respectively, P postpolio subjects than stable postpolio or control subjects. The cause for this finding is unknown and requires further investigation.

  5. Visual function assessment in simulated real-life situations in HIV-infected subjects.

    Directory of Open Access Journals (Sweden)

    Giulio Barteselli

    Full Text Available Visual function abnormalities are common in people living with HIV disease (PLWH without retinitis, even after improvement in immune status. Abnormalities such as reduced contrast sensitivity, altered color vision, peripheral visual field loss, and electrophysiological changes are related to a combination of retinal dysfunctions, involving inner and outer retinal structures. The standard protocol for testing vision performance in clinical practice is the Early Treatment Diabetic Retinopathy Study (ETDRS chart. However, this method poorly correlates with activities of daily living that require patients to assess visual stimuli in multiple light/contrast conditions, and with limited time. We utilized a novel interactive computer program (Central Vision Analyzer to analyze vision performance in PLWH under a variety of light/contrast conditions that simulate stressful and real-world environments. The program tests vision in a time-dependent way that we believe better correlates with daily living activities than the non-timed ETDRS chart. We also aimed to correlate visual scores with retinal neuro-fiber layer thickness on optical coherence tomography. Here we show that visual acuity is more affected in PLWH in comparison to HIV-seronegative controls in varying contrast and luminance, especially if the nadir CD4+ T-cell count was lower than 100 cells/mm3. Visual impairment reflects the loss of retinal nerve fiber layer thickness especially of the temporal-inferior sector. In PLWH the ETDRS chart test led to better visual acuity compared to the Central Vision Analyzer equivalent test, likely because patients had indefinite time to guess the letters. This study confirms and strengthens the finding that visual function is affected in PLWH even in absence of retinitis, since we found that the HIV serostatus is the best predictor of visual loss. The Central Vision Analyzer may be useful in the diagnosis of subclinical HIV-associated visual loss in multiple

  6. Depression in older people: visual impairment and subjective ratings of health.

    Science.gov (United States)

    Hayman, Karen J; Kerse, Ngaire M; La Grow, Steven J; Wouldes, Trecia; Robertson, M Clare; Campbell, A John

    2007-11-01

    The aim of this study was to establish the prevalence of depression in a sample of older adults with impaired vision and investigate associations between physical and visual disability and depression. We analyzed cross-sectional baseline data from 391 participants aged >or=75 years with visual acuity of 6/24 (20/80) or less, recruited for a randomized controlled trial of interventions to prevent falls (the VIP trial). Measures included the geriatric depression scale (GDS-15), the state-trait anxiety index, activities of daily living (Nottingham extended ADL scale), physical activity (human activity profile), an index of visual functioning (VF-14), health-related quality of life (SF-36), objective measures of physical ability, and a measure of visual acuity. Regression models were developed to investigate the association between depression scores and physical, psychological, and visual disability. About 29.4% (115 of 391) of participants were identified as potentially depressed (GDS-15 score >4). Physical function, physical activity, physical ability, visual function, anxiety, and self-reported physical and mental health were significantly worse for those with depressive symptomatology. Physical, visual, and psychological factors collectively explained 41% of the variance in the depression score in a linear regression model (R=0.421, adjusted R=0.410, F (7,382)=39.680, pvisual impairment. Impaired visual and physical functions were associated with symptoms of depression. The effect of visual disability was independent of the effect of physical disability. The strength of this relationship, and the results of the regression analyses, indicate that a person who is visually or physically disabled is more likely to suffer from depression.

  7. The insulin-mediated modulation of visually evoked magnetic fields is reduced in obese subjects.

    Directory of Open Access Journals (Sweden)

    Martina Guthoff

    Full Text Available BACKGROUND: Insulin is an anorexigenic hormone that contributes to the termination of food intake in the postprandial state. An alteration in insulin action in the brain, named "cerebral insulin resistance", is responsible for overeating and the development of obesity. METHODOLOGY/PRINCIPAL FINDINGS: To analyze the direct effect of insulin on food-related neuronal activity we tested 10 lean and 10 obese subjects. We conducted a magnetencephalography study during a visual working memory task in both the basal state and after applying insulin or placebo spray intranasally to bypass the blood brain barrier. Food and non-food pictures were presented and subjects had to determine whether or not two consecutive pictures belonged to the same category. Intranasal insulin displayed no effect on blood glucose, insulin or C-peptide concentrations in the periphery; however, it led to an increase in the components of evoked fields related to identification and categorization of pictures (at around 170 ms post stimuli in the visual ventral stream in lean subjects when food pictures were presented. In contrast, insulin did not modulate food-related brain activity in obese subjects. CONCLUSIONS/SIGNIFICANCE: We demonstrated that intranasal insulin increases the cerebral processing of food pictures in lean whereas this was absent in obese subjects. This study further substantiates the presence of a "cerebral insulin resistance" in obese subjects and might be relevant in the pathogenesis of obesity.

  8. Clinical evaluation of dynamic visual acuity in subjects with unilateral vestibular hypofunction.

    Science.gov (United States)

    Dannenbaum, Elizabeth; Paquet, Nicole; Chilingaryan, Gevorg; Fung, Joyce

    2009-04-01

    The objectives of this study are threefold: 1) to examine the effect of frequency of head motion on the clinical dynamic visual acuity (DVA) score in subjects with unilateral vestibular hypofunction (UVH); 2) to compare DVA scores between subjects with UVH and subjects with a complete unilateral vestibular deficit; and 3) to establish whether a relationship exists between the extent of the vestibular deficit and the DVA score. Experimental study. Vestibular outpatient rehabilitation program. A convenience sample of 10 subjects with UVH. Dynamic visual acuity scores were recorded using 2 standard acuity charts: Snellen and E-chart. The DVA scores were obtained at slow (0.5 Hz), moderate (1 and 1.5 Hz), and fast (2.0 Hz) frequencies of head motion in the horizontal and the vertical planes. Percentage of caloric weakness was compared with DVA scores in each subject to test whether a relationship exists between the two. As the frequency of head motion increased, the number of UVH subjects with an abnormal DVA score increased. Subjects with an abnormal DVA score at 1 Hz had the same or higher score as the frequency of the head motion was increased. Spearman correlation analyses revealed low-correlation coefficients between percentage of vestibular paresis at the caloric test and DVA scores (horizontal direction: r = 0.31, p = 0.38 for Snellen chart and r = -0.33, p = 0.35 for the E-chart; vertical: r = 0.05, p = 0.91 for the Snellen chart and r = -0.28, p = 0.50 for the E-chart). Subjects with UVH manifest impaired DVA. The frequency of head motion has an impact on clinical DVA scores in UVH subjects.

  9. Cognitive and functional patterns of nondemented subjects with equivocal visual amyloid PET findings

    Energy Technology Data Exchange (ETDEWEB)

    Payoux, P. [Purpan University Hospital, Department of Nuclear Medicine, CHU Toulouse, Toulouse (France); Inserm, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); INSERM U825, CHU Purpan, Toulouse Cedex (France); Delrieu, J. [Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); INSERM UMR 1027, Toulouse (France); Gallini, A.; Cantet, C.; Voisin, T.; Gillette-Guyonnet, S.; Vellas, B. [Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); INSERM UMR 1027, Toulouse (France); Adel, D.; Salabert, A.S. [Inserm, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Hitzel, A. [Purpan University Hospital, Department of Nuclear Medicine, CHU Toulouse, Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Tafani, M. [Purpan University Hospital, Department of Nuclear Medicine, CHU Toulouse, Toulouse (France); Inserm, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Verbizier, D. de [Montpellier University Hospital, Department of Nuclear Medicine, Montpellier (France); Darcourt, J. [Centre Antoine Lacassagne, Nuclear Medicine Department, Nice (France); University of Nice-Sophia Antipolis, Nice (France); Fernandez, P. [Pellegrin University Hospital Bordeaux, Nuclear Medicine Department, Bordeaux (France); University Bordeaux II, CNRS UMR 5287 - INCIA, Victor Segalen, Bordeaux (France); Monteil, J. [University Hospital, Department of Nuclear Medicine, Limoges (France); University of Limoges, Limoges (France); Carrie, I. [Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); Pontecorvo, M. [Avid Radiopharmaceuticals, Philadelphia, PA (United States); Andrieu, S. [Universite de Toulouse, UPS, Imagerie Cerebrale et Handicaps Neurologiques, UMR 825, Toulouse (France); Purpan University Hospital, Gerontopole, Department of Geriatrics, CHU Toulouse, Toulouse (France); INSERM UMR 1027, Toulouse (France); CHU Toulouse, Department of Epidemiology and Public Health, Toulouse (France)

    2015-08-15

    Despite good to excellent inter-reader agreement in the evaluation of amyloid load on PET scans in subjects with Alzheimer's disease, some equivocal findings have been reported in the literature. We aimed to describe the clinical characteristics of subjects with equivocal PET images. Nondemented subjects aged 70 years or more were enrolled from the MAPT trial. Cognitive and functional assessments were conducted at baseline, at 6 months, and annually for 3 years. During the follow-up period, 271 subjects had {sup 18}F-AV45 PET scans. Images were visually assessed by three observers and classified as positive, negative or equivocal (if one observer disagreed). After debate, equivocal images were reclassified as positive (EP+) or negative (EP-). Scans were also classified by semiautomated quantitative analysis using mean amyloid uptake of cortical regions. We evaluated agreement among the observers, and between visual and quantitative assessments using kappa coefficients, and compared the clinical characteristics of the subjects according to their PET results. In 158 subjects (58.30 %) the PET scan was negative for amyloid, in 77 (28.41 %) the scan was positive and in 36 (13.28 %) the scan was equivocal. Agreement among the three observers was excellent (kappa 0.80). Subjects with equivocal images were more frequently men (58 % vs. 37 %) and exhibited intermediate scores on cognitive and functional scales between those of subjects with positive and negative scans. Amyloid load differed between the EP- and negative groups and between the EP+ and positive groups after reclassification. Equivocal amyloid PET images could represent a neuroimaging entity with intermediate amyloid load but without a specific neuropsychological pattern. Clinical follow-up to assess cognitive evolution in subjects with equivocal scans is needed. (orig.)

  10. Effect of Subject Control and Graduated Exposure on Snake Phobias

    Science.gov (United States)

    Hepner, Alain; Cauthen, Nelson R.

    1975-01-01

    The influence of two of the variables in Leitenberg's graduated exposure technique for treating phobias, graduated exposure and subject control of the exposure time, was investigated using 15 snake-phobic subjects. Subjective fear significantly decreased from pretesting to posttesting. (Author)

  11. Gravity dependence of the effect of optokinetic stimulation on the subjective visual vertical.

    Science.gov (United States)

    Ward, Bryan K; Bockisch, Christopher J; Caramia, Nicoletta; Bertolini, Giovanni; Tarnutzer, Alexander Andrea

    2017-05-01

    Accurate and precise estimates of direction of gravity are essential for spatial orientation. According to Bayesian theory, multisensory vestibular, visual, and proprioceptive input is centrally integrated in a weighted fashion based on the reliability of the component sensory signals. For otolithic input, a decreasing signal-to-noise ratio was demonstrated with increasing roll angle. We hypothesized that the weights of vestibular (otolithic) and extravestibular (visual/proprioceptive) sensors are roll-angle dependent and predicted an increased weight of extravestibular cues with increasing roll angle, potentially following the Bayesian hypothesis. To probe this concept, the subjective visual vertical (SVV) was assessed in different roll positions (≤ ± 120°, steps = 30°, n = 10) with/without presenting an optokinetic stimulus (velocity = ± 60°/s). The optokinetic stimulus biased the SVV toward the direction of stimulus rotation for roll angles ≥ ± 30° (P integration when estimating direction of gravity with optokinetic stimulation. Visual input was weighted more when vestibular input became less reliable, i.e., at larger roll-tilt angles. However, according to Bayesian theory, the variability of combined cues is always lower than the variability of each source cue. If the observed increase in variability, although nonsignificant, is true, either it must depend on an additional source of variability, added after SVV computation, or it would conflict with the Bayesian hypothesis.NEW & NOTEWORTHY Applying a rotating optokinetic stimulus while recording the subjective visual vertical in different whole body roll angles, we noted the optokinetic-induced bias to correlate with the roll angle. These findings allow the hypothesis that the established optimal weighting of single-sensory cues depending on their reliability to estimate direction of gravity could be extended to a bias caused by visual self-motion stimuli. Copyright © 2017 the American Physiological

  12. Neural Substrates of Visual Spatial Coding and Visual Feedback Control for Hand Movements in Allocentric and Target-Directed Tasks

    Science.gov (United States)

    Thaler, Lore; Goodale, Melvyn A.

    2011-01-01

    Neuropsychological evidence suggests that different brain areas may be involved in movements that are directed at visual targets (e.g., pointing or reaching), and movements that are based on allocentric visual information (e.g., drawing or copying). Here we used fMRI to investigate the neural correlates of these two types of movements in healthy volunteers. Subjects (n = 14) performed right hand movements in either a target-directed task (moving a cursor to a target dot) or an allocentric task (moving a cursor to reproduce the distance and direction between two distal target dots) with or without visual feedback about their hand movement. Movements were monitored with an MR compatible touch panel. A whole brain analysis revealed that movements in allocentric conditions led to an increase in activity in the fundus of the left intra-parietal sulcus (IPS), in posterior IPS, in bilateral dorsal premotor cortex (PMd), and in the lateral occipital complex (LOC). Visual feedback in both target-directed and allocentric conditions led to an increase in activity in area MT+, superior parietal–occipital cortex (SPOC), and posterior IPS (all bilateral). In addition, we found that visual feedback affected brain activity differently in target-directed as compared to allocentric conditions, particularly in the pre-supplementary motor area, PMd, IPS, and parieto-occipital cortex. Our results, in combination with previous findings, suggest that the LOC is essential for allocentric visual coding and that SPOC is involved in visual feedback control. The differences in brain activity between target-directed and allocentric visual feedback conditions may be related to behavioral differences in visual feedback control. Our results advance the understanding of the visual coordinate frame used by the LOC. In addition, because of the nature of the allocentric task, our results have relevance for the understanding of neural substrates of magnitude estimation and vector coding of

  13. Layers Of Visual Imagination And Degrees Of Subjectivity In Listening Experiences Exploring Visual Imagination In Acousmatic Composition And Listening

    Directory of Open Access Journals (Sweden)

    Stefano Poillucci

    2015-08-01

    Full Text Available Abstract Electroacoustic music especially Acousmatic is often perceived differently between listeners and a wide variety of visual images is evoked. This because of the spectromorphological qualities and the abstract reality in which this kind of music carries the listener into. In everyday life it seems that we have a natural tendency to assess and understand reality around us and to quantise how and if the perceived circumstances could affect our wellbeing. Some studies also affirm that brain and the biological function of the sensory and perceptual processes are commonly identical in each listener. This gives evidence that arises the interest to investigate which variations the subjectivity of visual imagery depends on and if it is possible to unfold it in various layers. This experimental research has taken in consideration questionnaire-based listening tests to gather details from each listening experience and to get a better understanding of the visual imagery evoked by electroacoustic compositions into the listeners mind and its degrees of objectivity and subjectivity. The compositions used in the experiment were both composed by the author with the intention of guiding listeners into their personal perceptual-imaginative journey by delivering encoded perhaps objective sonic cues. This paper is a theoretical inter-disciplinary analysis backed by research on the foundations of senses perception cognition emotions etc. An artistic approach based on scientific evidences led to the theorization of layers of imagination and their bias to produce visual images with a degree of subjectivity that lies into micro aspects of sounds and in the perceptual and innate knowledge of each individual. Glossary The terms listed here have been invented or readapted for the purpose of the study in order to make concepts easier to assimilate and understand. Aural World sonic world with intrinsic features Smalley 1997. The purely auditory realm which an

  14. Ankylosing Spondylitis and Posture Control: The Role of Visual Input

    Directory of Open Access Journals (Sweden)

    Alessandro Marco De Nunzio

    2015-01-01

    Full Text Available Objectives. To assess the motor control during quiet stance in patients with established ankylosing spondylitis (AS and to evaluate the effect of visual input on the maintenance of a quiet posture. Methods. 12 male AS patients (mean age 50.1 ± 13.2 years and 12 matched healthy subjects performed 2 sessions of 3 trials in quiet stance, with eyes open (EO and with eyes closed (EC on a baropodometric platform. The oscillation of the centre of feet pressure (CoP was acquired. Indices of stability and balance control were assessed by the sway path (SP of the CoP, the frequency bandwidth (FB1 that includes the 80% of the area under the amplitude spectrum, the mean amplitude of the peaks (MP of the sway density curve (SDC, and the mean distance (MD between 2 peaks of the SDC. Results. In severe AS patients, the MD between two peaks of the SDC and the SP of the center of feet pressure were significantly higher than controls during both EO and EC conditions. The MP was significantly reduced just on EC. Conclusions. Ankylosing spondylitis exerts negative effect on postural stability, not compensable by visual inputs. Our findings may be useful in the rehabilitative management of the increased risk of falling in AS.

  15. Single-subject classification of schizophrenia using event-related potentials obtained during auditory and visual oddball paradigms.

    Science.gov (United States)

    Neuhaus, Andres H; Popescu, Florin C; Bates, John A; Goldberg, Terry E; Malhotra, Anil K

    2013-04-01

    In the search for the biomarkers of schizophrenia, event-related potential (ERP) deficits obtained by applying the classic oddball paradigm are among the most consistent findings. However, the single-subject classification rate based on these parameters remains to be determined. Here, we present a data-driven approach by applying machine learning classifiers to relevant oddball ERPs. Twenty-four schizophrenic patients and 24 matched healthy controls finished auditory and visual oddball tasks while high-density electrophysiological recordings were applied. The N1 component in response to standards and target as well as the P3 component following targets were submitted to different machine learning algorithms and the resulting ERP features were submitted to further correlation analyses. We obtained a classification accuracy of 72.4 % using only two ERP components. Latencies of parietal N1 components to visual standard stimuli at electrode positions Pz and P1 were sufficient for classification. Further analysis revealed a high correlation of these features in controls and an intermediate correlation in schizophrenia patients. These data exemplarily show how automated inference may be applied to classify a pathological state in single subjects without prior knowledge of their diagnoses and illustrate the potential of machine learning algorithms for the identification of potential biomarkers. Moreover, this approach assesses the discriminative accuracy of one of the most consistent findings in schizophrenia research by means of single-subject classification.

  16. Older adults, diabetes mellitus and visual acuity: a community-based case-control study.

    Science.gov (United States)

    Sinclair, A J; Bayer, A J; Girling, A J; Woodhouse, K W

    2000-07-01

    to screen for impaired distance visual acuity in older adults living at home, both with and without diabetes mellitus to determine whether diabetes increases the likelihood of visual impairment and to identify associated factors. case-control study. three districts of Wales: North Clwyd, Powys and South Glamorgan, with assessments in subjects' homes. 385 with diabetes mellitus and 385 age- and sex-matched controls. visual acuity measures, short form (SF)-36 quality of life scores we observed impairment of visual acuity in 40% of those with diabetes mellitus and 31% of controls. Diabetes was associated with an increased risk of visual impairment [odds ratio 1.50 (95% confidence interval 1.09-2.05), P = 0.013]. The pinhole test identified uncorrected refractive error in 11% of the 63 patients with diabetes and 12% of the 49 controls who wore glasses, and in 51% of the 91 patients and 84% of the 69 controls who did not wear glasses (P < 0.001). Increasing age (P < 0.001) and female sex (P = 0.014) were significantly associated with visual impairment in both groups, whilst history of foot ulceration (P = 0.001), duration of diabetes (P = 0.018) and treatment with insulin (P < 0.001) were significantly associated with visual impairment in subjects with diabetes. We observed a significant association between impaired visual acuity and five domains of the SF-36 (physical and social functioning, mental health, vitality, and health perceptions; P < 0.01 in each case). older adults living at home have a high prevalence of uncorrected visual impairment. Diabetes mellitus is associated with significantly increased risk of visual loss. This impairment is associated with detriments in health-related quality of life. We recommend earlier use of optometry services and assessment of visual acuity by clinicians.

  17. Lack of habituation of evoked visual potentials in analytic information processing style: evidence in healthy subjects.

    Science.gov (United States)

    Buonfiglio, Marzia; Toscano, M; Puledda, F; Avanzini, G; Di Clemente, L; Di Sabato, F; Di Piero, V

    2015-03-01

    Habituation is considered one of the most basic mechanisms of learning. Habituation deficit to several sensory stimulations has been defined as a trait of migraine brain and also observed in other disorders. On the other hand, analytic information processing style is characterized by the habit of continually evaluating stimuli and it has been associated with migraine. We investigated a possible correlation between lack of habituation of evoked visual potentials and analytic cognitive style in healthy subjects. According to Sternberg-Wagner self-assessment inventory, 15 healthy volunteers (HV) with high analytic score and 15 HV with high global score were recruited. Both groups underwent visual evoked potentials recordings after psychological evaluation. We observed significant lack of habituation in analytical individuals compared to global group. In conclusion, a reduced habituation of visual evoked potentials has been observed in analytic subjects. Our results suggest that further research should be undertaken regarding the relationship between analytic cognitive style and lack of habituation in both physiological and pathophysiological conditions.

  18. Selective use of visual information signaling objects' center of mass for anticipatory control of manipulative fingertip forces.

    Science.gov (United States)

    Salimi, Iran; Frazier, Wendy; Reilmann, Ralf; Gordon, Andrew M

    2003-05-01

    The present study examines whether visual information indicating the center of mass (CM) of an object can be used for the appropriate scaling of fingertip forces at each digit during precision grip. In separate experiments subjects lifted an object with various types of visual cues concerning the CM location several times and then rotated and lifted it again to determine whether the visual cues signaling the new location of the CM could be used to appropriately scale the fingertip forces. Specifically, subjects had either no visual cues, visual instructional cues (i.e., an indicator) or visual geometric cues where the longer axis of the object indicated the CM. When no visual cues were provided, subjects were unable to appropriately scale the load forces at each digit following rotation despite their knowledge of the new weight distribution. When visual cues regarding the CM location were provided, the nature of the visual cues determined their effectiveness in retrieval of internal representations underlying the anticipatory scaling of fingertip forces. Specifically, when subjects were provided with visual instructional information, they were unable to appropriately scale the forces. More appropriate scaling of the load forces occurred when the visual cues were ecologically meaningful, i.e., when the shape of the object indicated the CM location. We suggest that visual instructional cues do not have access to the implicit processes underlying dynamic force control, whereas visual geometric cues can be used for the retrieval of the internal representation related to CM for appropriate partitioning of the forces in each digit.

  19. Interactive tag cloud visualization of software version control repositories

    CSIR Research Space (South Africa)

    Greene, GJ

    2015-09-01

    Full Text Available Visualization of Software: Version Control Repositories Gillian J. Greene and Bernd Fischer Abstract: Version control repositories contain a wealth of implicit information that can be used to answer many questions about a project’s development process...

  20. A visual test based on a freeware software for quantifying and displaying night-vision disturbances: study in subjects after alcohol consumption

    National Research Council Canada - National Science Library

    Castro, José J; Ortiz, Carolina; Pozo, Antonio M; Anera, Rosario G; Soler, Margarita

    2014-01-01

    .... The test, performed by subjects before and after consuming alcoholic drinks, which deteriorate visual performance, evaluates the influence that alcohol consumption exerts on the visual-discrimination...

  1. Visual P3a in male alcoholics and controls.

    Science.gov (United States)

    Rodriguez Holguin, S; Porjesz, B; Chorlian, D B; Polich, J; Begleiter, H

    1999-04-01

    The goal of this study was to assess the P3a component of event-related potentials in a population of abstinent, chronic alcoholics. A three-stimulus visual oddball paradigm was used to elicit robust P3a components in a large group of well-characterized male alcoholics (n = 44) and controls (n = 28). The task required subjects to make a difficult perceptual discrimination between randomly presented, frequently occurring vertical lines (.80) and infrequent target lines that were tilted 2 degrees to the right of vertical (.10) by only responding with a button press to the target stimuli. A nontarget infrequent horizontal line occurred (.10) randomly to which no response was made. The target stimulus elicited robust late P3b components with a parietal maximum amplitude, and the nontarget stimulus elicited reliable P3a components with a fronto-central maximum amplitude distribution. Group differences in P3a were assessed using repeated measures ANCOVA analyses in five scalp regions. Alcoholic subjects produced smaller P3a amplitudes over the central, parietal, temporal, and occipital areas compared with controls. Current source density analyses supported these findings with extension of the differences between the groups to the frontal region. The results suggest that the P3a may be important in the evaluation of alcoholism and its heritability. Theoretical implications are discussed.

  2. Visual reaction times during prolonged angular acceleration parallel the subjective perception of rotation

    Science.gov (United States)

    Mattson, D. L.

    1975-01-01

    The effect of prolonged angular acceleration on choice reaction time to an accelerating visual stimulus was investigated, with 10 commercial airline pilots serving as subjects. The pattern of reaction times during and following acceleration was compared with the pattern of velocity estimates reported during identical trials. Both reaction times and velocity estimates increased at the onset of acceleration, declined prior to the termination of acceleration, and showed an aftereffect. These results are inconsistent with the torsion-pendulum theory of semicircular canal function and suggest that the vestibular adaptation is of central origin.

  3. Metacognition of visual short-term memory: Dissociation between objective and subjective components of VSTM

    Directory of Open Access Journals (Sweden)

    Silvia eBona

    2013-02-01

    Full Text Available The relationship between the objective accuracy of visual-short term memory (VSTM representations and their subjective conscious experience is unknown. We investigated this issue by assessing how the objective and subjective components of VSTM in a delayed cue-target orientation discrimination task are affected by intervening distracters. On each trial, participants were shown a memory cue (a grating, the orientation of which they were asked to hold in memory. On approximately half of the trials, a distractor grating appeared during the maintenance interval; its orientation was either identical to that of the memory cue, or it differed by 10 or 40 degrees. The distractors were masked and presented briefly, so they were only consciously perceived on a subset of trials. At the end of the delay period, a memory test probe was presented, and participants were asked to indicate whether it was tilted to the left or right relative to the memory cue (VSTM accuracy; objective performance. In order to assess subjective metacognition, participants were asked indicate the vividness of their memory for the original memory cue. Finally, participants were asked rate their awareness of the distracter. Results showed that objective VSTM performance was impaired by distractors only when the distractors were very different from the cue, and that this occurred with both subjectively visible and invisible distractors. Subjective metacognition, however, was impaired by distractors of all orientations, but only when these distractors were subjectively invisible. Our results thus indicate that the objective and subjective components of VSTM are to some extent dissociable.

  4. Investigating the visual inspection subjectivity on the contrast-detail evaluation in digital mammography images

    Science.gov (United States)

    Sousa, Maria A. Z.; Medeiros, Regina B.; Schiabel, Homero

    2014-03-01

    A major difficulty in the interpretation of mammographic images is the low contrast and, in the case of early detection of breast cancer, the reduced size of the features of malignancy on findings such as microcalcifications. Furthermore, image assessment is subject to significant reliance of the capacity of observation of the expert that will perform it, compromising the final diagnosis accuracy. Thinking about this aspect, this study evaluated the subjectivity of visual inspection to assess the contrast-detail in mammographic images. For this, we compared the human readings of images generated with the CDMAM phantom performed by four observers, enabling to determining a threshold of contrast visibility in each diameter disks present in the phantom. These thresholds were compared graphically and by statistical measures allowing us to build a strategy for use of contrast and detail (dimensions) as parameters of quality in mammography.

  5. Preserved and attenuated electrophysiological correlates of visual spatial attention in elderly subjects.

    Science.gov (United States)

    van der Waal, Marjolein; Farquhar, Jason; Fasotti, Luciano; Desain, Peter

    2017-01-15

    Healthy aging is associated with changes in many neurocognitive functions. While on the behavioral level, visual spatial attention capacities are relatively stable with increasing age, the underlying neural processes change. In this study, we investigated attention-related modulations of the stimulus-locked event-related potential (ERP) and occipital oscillations in the alpha band (8-14Hz) in young and elderly participants. Both groups performed a visual attention task equally well and the ERP showed comparable attention-related modulations in both age groups. However, in elderly subjects, oscillations in the alpha band were massively reduced both during the task and in the resting state and the typical task-related lateralized pattern of alpha activity was not observed. These differences between young and elderly participants were observed on the group level as well as on the single trial level. The results indicate that younger and older adults use different neural strategies to reach the same performance in a covert visual spatial attention task. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Visualizing Concurrency Control Algorithms for Real-Time Database Systems

    Directory of Open Access Journals (Sweden)

    Olusegun Folorunso

    2008-11-01

    Full Text Available This paper describes an approach to visualizing concurrency control (CC algorithms for real-time database systems (RTDBs. This approach is based on the principle of software visualization, which has been applied in related fields. The Model-View-controller (MVC architecture is used to alleviate the black box syndrome associated with the study of algorithm behaviour for RTDBs Concurrency Controls. We propose a Visualization "exploratory" tool that assists the RTDBS designer in understanding the actual behaviour of the concurrency control algorithms of choice and also in evaluating the performance quality of the algorithm. We demonstrate the feasibility of our approach using an optimistic concurrency control model as our case study. The developed tool substantiates the earlier simulation-based performance studies by exposing spikes at some points when visualized dynamically that are not observed using usual static graphs. Eventually this tool helps solve the problem of contradictory assumptions of CC in RTDBs.

  7. Effects of Visual Communication Tool and Separable Status Display on Team Performance and Subjective Workload in Air Battle Management

    National Research Council Canada - National Science Library

    Schwartz, Daniel; Knott, Benjamin A; Galster, Scott M

    2008-01-01

    ... ambient cabin noise while performing several visual and manual tasks. The purpose of this study is to compare team performance and subjective workload on a simulated AWACS scenario, for two conditions of communication...

  8. An Evaluation of a Computer-Based Training on the Visual Analysis of Single-Subject Data

    Science.gov (United States)

    Snyder, Katie

    2013-01-01

    Visual analysis is the primary method of analyzing data in single-subject methodology, which is the predominant research method used in the fields of applied behavior analysis and special education. Previous research on the reliability of visual analysis suggests that judges often disagree about what constitutes an intervention effect. Considering…

  9. Are Autonomous and Controlled Motivations School-Subjects-Specific?

    Directory of Open Access Journals (Sweden)

    Julien Chanal

    Full Text Available This research sought to test whether autonomous and controlled motivations are specific to school subjects or more general to the school context. In two cross-sectional studies, 252 elementary school children (43.7% male; mean age = 10.7 years, SD = 1.3 years and 334 junior high school children (49.7% male, mean age = 14.07 years, SD = 1.01 years were administered a questionnaire assessing their motivation for various school subjects. Results based on structural equation modeling using the correlated trait-correlated method minus one model (CTCM-1 showed that autonomous and controlled motivations assessed at the school subject level are not equally school-subject-specific. We found larger specificity effects for autonomous (intrinsic and identified than for controlled (introjected and external motivation. In both studies, results of factor loadings and the correlations with self-concept and achievement demonstrated that more evidence of specificity was obtained for autonomous regulations than for controlled ones. These findings suggest a new understanding of the hierarchical and multidimensional academic structure of autonomous and controlled motivations and of the mechanisms involved in the development of types of regulations for school subjects.

  10. Are Autonomous and Controlled Motivations School-Subjects-Specific?

    Science.gov (United States)

    Chanal, Julien; Guay, Frédéric

    2015-01-01

    This research sought to test whether autonomous and controlled motivations are specific to school subjects or more general to the school context. In two cross-sectional studies, 252 elementary school children (43.7% male; mean age = 10.7 years, SD = 1.3 years) and 334 junior high school children (49.7% male, mean age = 14.07 years, SD = 1.01 years) were administered a questionnaire assessing their motivation for various school subjects. Results based on structural equation modeling using the correlated trait-correlated method minus one model (CTCM-1) showed that autonomous and controlled motivations assessed at the school subject level are not equally school-subject-specific. We found larger specificity effects for autonomous (intrinsic and identified) than for controlled (introjected and external) motivation. In both studies, results of factor loadings and the correlations with self-concept and achievement demonstrated that more evidence of specificity was obtained for autonomous regulations than for controlled ones. These findings suggest a new understanding of the hierarchical and multidimensional academic structure of autonomous and controlled motivations and of the mechanisms involved in the development of types of regulations for school subjects.

  11. Are Autonomous and Controlled Motivations School-Subjects-Specific?

    Science.gov (United States)

    Chanal, Julien; Guay, Frédéric

    2015-01-01

    This research sought to test whether autonomous and controlled motivations are specific to school subjects or more general to the school context. In two cross-sectional studies, 252 elementary school children (43.7% male; mean age = 10.7 years, SD = 1.3 years) and 334 junior high school children (49.7% male, mean age = 14.07 years, SD = 1.01 years) were administered a questionnaire assessing their motivation for various school subjects. Results based on structural equation modeling using the correlated trait-correlated method minus one model (CTCM-1) showed that autonomous and controlled motivations assessed at the school subject level are not equally school-subject-specific. We found larger specificity effects for autonomous (intrinsic and identified) than for controlled (introjected and external) motivation. In both studies, results of factor loadings and the correlations with self-concept and achievement demonstrated that more evidence of specificity was obtained for autonomous regulations than for controlled ones. These findings suggest a new understanding of the hierarchical and multidimensional academic structure of autonomous and controlled motivations and of the mechanisms involved in the development of types of regulations for school subjects. PMID:26247788

  12. Symptoms of Meares-Irlen/Visual Stress Syndrome in subjects diagnosed with Chronic Fatigue Syndrome

    OpenAIRE

    Loew, Stephen J.; Nigel V. Marsh; Watson, Kenneth

    2014-01-01

    Algunos síntomas del Síndrome de Estrés Visual/Meares-Irlen son similares a los informados por individuos con síndrome de fatiga crónica (SFC). Se evaluó la incidencia de nueve síntomas ampliamente reconocidos de estrés visual (EV) en un grupo de sujetos (n = 20) con síndrome de fatiga crónica. La presencia de cada síntoma de EV en el grupo con SFC se comparó con un grupo control de sujetos sanos (n = 46) y con un grupo de individuos (n = 14) con diagnóstico de EV, equiparables en sexo y edad...

  13. Postural Control in Young People with Visual Impairments and Various Risks of Falls

    Science.gov (United States)

    Sadowska, Dorota; Stemplewski, Rafal; Szeklicki, Robert

    2017-01-01

    Introduction: Early diagnosis of postural control deficiencies facilitates implementation of an individual rehabilitation plan to prevent falls. The aim of the study was to assess the risk of falling in individuals with visual impairments, and to compare performance-based and theoretical limits of stability in subjects with various risks of…

  14. Comparison of Subjective and Objective Sleep Estimations in Patients with Bipolar Disorder and Healthy Control Subjects

    Directory of Open Access Journals (Sweden)

    Philipp S. Ritter

    2016-01-01

    Full Text Available Background. Several studies have described but not formally tested discrepancies between subjective and objective measures of sleep. Study Objectives. To test the hypothesis that patients with bipolar disorder display a systematic bias to underestimate sleep duration and overestimate sleep latency. Methods. Actimetry was used to assess sleep latency and duration in 49 euthymic participants (bipolar = 21; healthy controls = 28 for 5–7 days. Participants simultaneously recorded estimated sleep duration and sleep latency on a daily basis via an online sleep diary. Group differences in the discrepancy between subjective and objective parameters were calculated using t-tests and corrected for multiple comparisons. Results. Patients with bipolar disorder significantly underestimated their sleep duration but did not overestimate their sleep latency compared to healthy controls. Conclusions. Studies utilizing diaries or questionnaires alone in patients with bipolar disorders may systematically underestimate sleep duration compared to healthy controls. The additional use of objective assessment methods such as actimetry is advisable.

  15. Imaged-Based Visual Servo Control for a VTOL Aircraft

    Directory of Open Access Journals (Sweden)

    Liying Zou

    2017-01-01

    Full Text Available This paper presents a novel control strategy to force a vertical take-off and landing (VTOL aircraft to accomplish the pinpoint landing task. The control development is based on the image-based visual servoing method and the back-stepping technique; its design differs from the existing methods because the controller maps the image errors onto the actuator space via a visual model which does not contain the depth information of the feature point. The novelty of the proposed method is to extend the image-based visual servoing technique to the VTOL aircraft control. In addition, the Lyapunov theory is used to prove the asymptotic stability of the VTOL aircraft visual servoing system, while the image error can converge to zero. Furthermore, simulations have been also conducted to demonstrate the performances of the proposed method.

  16. Natural control capabilities of robotic hands by hand amputated subjects.

    Science.gov (United States)

    Atzori, Manfredo; Gijsberts, Arjan; Caputo, Barbara; Muller, Henning

    2014-01-01

    People with transradial hand amputations who own a myoelectric prosthesis currently have some control capabilities via sEMG. However, the control systems are still limited and not natural. The Ninapro project is aiming at helping the scientific community to overcome these limits through the creation of publicly available electromyography data sources to develop and test machine learning algorithms. In this paper we describe the movement classification results gained from three subjects with an homogeneous level of amputation, and we compare them with the results of 40 intact subjects. The number of considered subjects can seem small at first sight, but it is not considering the literature of the field (which has to face the difficulty of recruiting trans-radial hand amputated subjects). The classification is performed with four different classifiers and the obtained balanced classification rates are up to 58.6% on 50 movements, which is an excellent result compared to the current literature. Successively, for each subject we find a subset of up to 9 highly independent movements, (defined as movements that can be distinguished with more than 90% accuracy), which is a deeply innovative step in literature. The natural control of a robotic hand in so many movements could lead to an immediate progress in robotic hand prosthetics and it could deeply change the quality of life of amputated subjects.

  17. Patient DF's visual brain in action: Visual feedforward control in visual form agnosia.

    Science.gov (United States)

    Whitwell, Robert L; Milner, A David; Cavina-Pratesi, Cristiana; Barat, Masihullah; Goodale, Melvyn A

    2015-05-01

    Patient DF, who developed visual form agnosia following ventral-stream damage, is unable to discriminate the width of objects, performing at chance, for example, when asked to open her thumb and forefinger a matching amount. Remarkably, however, DF adjusts her hand aperture to accommodate the width of objects when reaching out to pick them up (grip scaling). While this spared ability to grasp objects is presumed to be mediated by visuomotor modules in her relatively intact dorsal stream, it is possible that it may rely abnormally on online visual or haptic feedback. We report here that DF's grip scaling remained intact when her vision was completely suppressed during grasp movements, and it still dissociated sharply from her poor perceptual estimates of target size. We then tested whether providing trial-by-trial haptic feedback after making such perceptual estimates might improve DF's performance, but found that they remained significantly impaired. In a final experiment, we re-examined whether DF's grip scaling depends on receiving veridical haptic feedback during grasping. In one condition, the haptic feedback was identical to the visual targets. In a second condition, the haptic feedback was of a constant intermediate width while the visual target varied trial by trial. Despite this incongruent feedback, DF still scaled her grip aperture to the visual widths of the target blocks, showing only normal adaptation to the false haptically-experienced width. Taken together, these results strengthen the view that DF's spared grasping relies on a normal mode of dorsal-stream functioning, based chiefly on visual feedforward processing. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. A comparative study of visual reaction time in table tennis players and healthy controls.

    Science.gov (United States)

    Bhabhor, Mahesh K; Vidja, Kalpesh; Bhanderi, Priti; Dodhia, Shital; Kathrotia, Rajesh; Joshi, Varsha

    2013-01-01

    Visual reaction time is time required to response to visual stimuli. The present study was conducted to measure visual reaction time in 209 subjects, 50 table tennis (TT) players and 159 healthy controls. The visual reaction time was measured by the direct RT computerized software in healthy controls and table tennis players. Simple visual reaction time was measured. During the reaction time testing, visual stimuli were given for eighteen times and average reaction time was taken as the final reaction time. The study shows that table tennis players had faster reaction time than healthy controls. On multivariate analysis, it was found that TT players had 74.121 sec (95% CI 98.8 and 49.4 sec) faster reaction time compared to non-TT players of same age and BMI. Also playing TT has a profound influence on visual reaction time than BMI. Our study concluded that persons involved in sports are having good reaction time as compared to controls. These results support the view that playing of table tennis is beneficial to eye-hand reaction time, improve the concentration and alertness.

  19. Visual servo control for a human-following robot

    CSIR Research Space (South Africa)

    Burke, Michael G

    2011-03-01

    Full Text Available This thesis presents work completed on the design of control and vision components for use in a monocular vision-based human-following robot. The use of vision in a controller feedback loop is referred to as vision-based or visual servo control...

  20. Subjectivity

    Directory of Open Access Journals (Sweden)

    Jesús Vega Encabo

    2015-11-01

    Full Text Available In this paper, I claim that subjectivity is a way of being that is constituted through a set of practices in which the self is subject to the dangers of fictionalizing and plotting her life and self-image. I examine some ways of becoming subject through narratives and through theatrical performance before others. Through these practices, a real and active subjectivity is revealed, capable of self-knowledge and self-transformation. 

  1. The Worringham and Beringer 'visual field' principle for rotary controls.

    Science.gov (United States)

    Hoffmann, Errol R; Chan, Alan H S

    2013-01-01

    Worringham and Beringer (1989, 1998) developed a very important principle relating compatibility of movement of horizontally moving translational controls to display movements when the operator's view of the display is in a plane different to that of the control. On the basis of past data of the current authors, it is shown that the visual field principle also applies to the operation of vertically moving translational controls and to rotary controls. These additions make the Worringham and Beringer principle the most powerful design principle available for situations where the operator is viewing a display that is not in the same plane as the control. High compatibility between control input and display output is of great importance in machine design. This paper demonstrates that, for cases where the display is not in the same plane as the control, the visual field principle is operational for vertically moving translational controls and rotary controls as well as for horizontally moving translational controls.

  2. Visual and subjective outcomes of phototherapeutic keratectomy after Descemet’s stripping endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Lee BS

    2014-05-01

    Full Text Available Bryan S Lee,1,2 David R Hardten21Department of Ophthalmology, University of Washington, Seattle, WA, 2Minnesota Eye Consultants, Minneapolis, MN, USABackground: Patients with endothelial disease also often have scarring or surface corneal disease. This study examined the outcomes of phototherapeutic keratectomy (PTK performed in patients with prior Descemet’s stripping endothelial keratoplasty (DSEK.Methods: This retrospective case series examined all patients undergoing PTK after DSEK in a single private practice. The primary outcome was best-corrected visual acuity, with secondary outcomes of change in spherical equivalent versus targeted change, change in endothelial cell count, improvement in corneal topography, and subjective satisfaction with vision.Results: For the ten patients who met the inclusion criteria, mean best-corrected visual acuity improved from logarithm of the minimum angle of resolution (logMAR 0.43 to 0.36 (P=0.24 at the most recent postoperative visit. PTK treatments that included a refractive component showed good predictability of 1.13 diopters spherical equivalent/diopter attempted. There was no evidence of a decrease in endothelial cell count from PTK, even with the use of mitomycin C (P=0.95. Subjectively, 80% of patients noted improvement in their vision. Conclusion: PTK after DSEK has the potential to improve patients’ vision with high levels of patient satisfaction, even though many patients had significant ocular comorbidities. Surgeons should consider using PTK to treat anterior corneal pathology following DSEK.Keywords: phototherapeutic keratectomy, Descemet’s stripping endothelial keratoplasty, anterior basement membrane dystrophy, irregular astigmatism

  3. Training compensatory viewing strategies : feasiblity and effect on practical fitness to drive in subjects with visual field defects

    NARCIS (Netherlands)

    Coeckelbergh, Tanja R.M.; Brouwer, Wiebo H.; Cornelissen, Frans W.; Kooijman, Aart C.

    2002-01-01

    Fifty-one subjects with visual field defects were trained to use compensatory viewing strategies.The subjects were referred to the training program by an official driving examiner of the Dutch Central Bureau of Driving Licenses. Three training programs were compared: laboratory training, mobility

  4. Two visual working memory representations simultaneously control attention.

    Science.gov (United States)

    Chen, Yanan; Du, Feng

    2017-07-21

    It has been proposed that only one visual working memory (VWM) representation can be activated to influence perception directly, whereas other VWM representations are accessory items which have little influence on visual selection. The sole active VWM representation might reflect a fundamental bottleneck in the information processing of human beings. However, the present study showed that each of two VWM representations can capture attention and interfere with concurrent visual search. In addition, each of two VWM representations can interfere with concurrent visual search as much as can a single cued VWM representation. Moreover, when two memory-matching distractors appear in visual search, two VWM representations produce a larger memory-driven capture effect than a single memory-matching distractor. Thus, two VWM representations can simultaneously control attention.

  5. Evaluating the Graph-based Visualization Technique: A Controlled Experiment

    Directory of Open Access Journals (Sweden)

    Germán Oswaldo Cárdenas

    2017-02-01

    Full Text Available Many researchers have highlighted the scarcity of empirical studies that systematically examine the advantages and disadvantages of the use of visualization techniques for software understanding activities. Such studies are crucial for gathering and analyzing objective and quantifiable evidence about the usefulness of proposed visualization techniques and tools, and ultimately, for guiding the research in software visualization. This paper presents a controlled experiment aimed at assessing the impact of a graph-based visualization technique on comprehension tasks. Six common comprehension tasks were performed by 20 undergraduate software engineering students. The completion time and the accuracy of the participants’ responses were measured. The results indicate that on one hand the use of the graph-based visualization increases the correctness (by 21.45% in average but on the other hand it does not reduce the completion time in program comprehension tasks.

  6. Visual cues for manual control of headway

    National Research Council Canada - National Science Library

    Hosking, Simon G; Davey, Catherine E; Kaiser, Mary K

    2013-01-01

    ... regulation of braking, and manual control of headway. However, investigations of headway maintenance have required participants to maintain a fixed distance headway and have not investigated how information about own-speed is taken into account...

  7. Virtual Visual Effect of Hospital Waiting Room on Pain Modulation in Healthy Subjects and Patients with Chronic Migraine

    Directory of Open Access Journals (Sweden)

    Marina de Tommaso

    2013-01-01

    Full Text Available Environmental context has an important impact on health and well being. We aimed to test the effects of a visual distraction induced by classical hospital waiting room (RH versus an ideal room with a sea view (IH, both represented in virtual reality (VR, on subjective sensation and cortical responses induced by painful laser stimuli (LEPs in healthy volunteers and patients with chronic migraine (CM. Sixteen CM and 16 controls underwent 62 channels LEPs from the right hand, during a fully immersive VR experience, where two types of waiting rooms were simulated. The RH simulated a classical hospital waiting room while the IH represented a room with sea viewing. CM patients showed a reduction of laser pain rating and vertex LEPs during the IH vision. The sLORETA analysis confirmed that in CM patients the two VR simulations induced a different modulation of bilateral parietal cortical areas (precuneus and superior parietal lobe, and superior frontal and cingulate girus, in respect to controls. The architectural context may interfere with pain perception, depending upon the status of subject. Many variables may change patients’ outcome and support the use of VR technology to test the best conditions for their management.

  8. Visual control of steering in the box jellyfish Tripedalia cystophora

    DEFF Research Database (Denmark)

    Petie, Ronald; Garm, Anders; Nilsson, Dan-Eric

    2011-01-01

    Box jellyfish carry an elaborate visual system consisting of 24 eyes, which they use for driving a number of behaviours. However, it is not known how visual input controls the swimming behaviour. In this study we exposed the Caribbean box jellyfish Tripedalia cystophora to simple visual stimuli...... and recorded changes in their swimming behaviour. Animals were tethered in a small experimental chamber, where we could control lighting conditions. The behaviour of the animals was quantified by tracking the movements of the bell, using a high-speed camera. We found that the animals respond predictably...... their bell in such a way that, if not tethered, they would turn and swim away from the dark area. We conclude that the visual system of T. cystophora has a predictable effect on swimming behaviour....

  9. Are Autonomous and Controlled Motivations School-Subjects-Specific ?

    OpenAIRE

    Julien Chanal; Frédéric Guay

    2015-01-01

    This research sought to test whether autonomous and controlled motivations are specific to school subjects or more general to the school context. In two cross-sectional studies, 252 elementary school children (43.7% male; mean age = 10.7 years, SD = 1.3 years) and 334 junior high school children (49.7% male, mean age = 14.07 years, SD = 1.01 years) were administered a questionnaire assessing their motivation for various school subjects. Results based on structural equation modeling using the ...

  10. Handwriting performance in the absence of visual control in writer's cramp patients: Initial observations

    Directory of Open Access Journals (Sweden)

    Losch Florian

    2006-04-01

    Full Text Available Abstract Background The present study was aimed at investigating the writing parameters of writer's cramp patients and control subjects during handwriting of a test sentence in the absence of visual control. Methods Eight right-handed patients with writer's cramp and eight healthy volunteers as age-matched control subjects participated in the study. The experimental task consisted in writing a test sentence repeatedly for fifty times on a pressure-sensitive digital board. The subject did not have visual control on his handwriting. The writing performance was stored on a PC and analyzed off-line. Results During handwriting all patients developed a typical dystonic limb posture and reported an increase in muscular tension along the experimental session. The patients were significantly slower than the controls, with lower mean vertical pressure of the pen tip on the paper and they could not reach the endmost letter of the sentence in the given time window. No other handwriting parameter differences were found between the two groups. Conclusion Our findings indicate that during writing in the absence of visual feedback writer's cramp patients are slower and could not reach the endmost letter of the test sentence, but their level of automatization is not impaired and writer's cramp handwriting parameters are similar to those of the controls except for even lower vertical pressure of the pen tip on the paper, which is probably due to a changed strategy in such experimental conditions.

  11. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

    Science.gov (United States)

    Berry, Meredith S; Repke, Meredith A; Nickerson, Norma P; Conway, Lucian G; Odum, Amy L; Jordan, Kerry E

    2015-01-01

    Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise) currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes) relative to built (buildings, cities) environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as opposed to built

  12. Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity.

    Directory of Open Access Journals (Sweden)

    Meredith S Berry

    Full Text Available Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes relative to built (buildings, cities environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as

  13. Gestalt Theory in Visual Screen Design — A New Look at an old subject

    OpenAIRE

    Chang, D.; Dooley, L.; Tuovinen, J. E

    2002-01-01

    Although often presented as a single basis for educational visual screen design, Gestalt theory is not a single small set of visual principles uniformly applied by all designers. In fact, it appears that instructional visual design literature often deals with only a small set of Gestalt laws. In this project Gestalt literature was consulted to distil the most relevant Gestalt laws for educational visual screen design. Eleven laws were identified. They deal with balance/symmetry, continuation,...

  14. An electrocorticographic BCI using code-based VEP for control in video applications: a single-subject study.

    Science.gov (United States)

    Kapeller, Christoph; Kamada, Kyousuke; Ogawa, Hiroshi; Prueckl, Robert; Scharinger, Josef; Guger, Christoph

    2014-01-01

    A brain-computer-interface (BCI) allows the user to control a device or software with brain activity. Many BCIs rely on visual stimuli with constant stimulation cycles that elicit steady-state visual evoked potentials (SSVEP) in the electroencephalogram (EEG). This EEG response can be generated with a LED or a computer screen flashing at a constant frequency, and similar EEG activity can be elicited with pseudo-random stimulation sequences on a screen (code-based BCI). Using electrocorticography (ECoG) instead of EEG promises higher spatial and temporal resolution and leads to more dominant evoked potentials due to visual stimulation. This work is focused on BCIs based on visual evoked potentials (VEP) and its capability as a continuous control interface for augmentation of video applications. One 35 year old female subject with implanted subdural grids participated in the study. The task was to select one out of four visual targets, while each was flickering with a code sequence. After a calibration run including 200 code sequences, a linear classifier was used during an evaluation run to identify the selected visual target based on the generated code-based VEPs over 20 trials. Multiple ECoG buffer lengths were tested and the subject reached a mean online classification accuracy of 99.21% for a window length of 3.15 s. Finally, the subject performed an unsupervised free run in combination with visual feedback of the current selection. Additionally, an algorithm was implemented that allowed to suppress false positive selections and this allowed the subject to start and stop the BCI at any time. The code-based BCI system attained very high online accuracy, which makes this approach very promising for control applications where a continuous control signal is needed.

  15. Adrenergic receptors on cerebral microvessels in control and Parkinsonian subjects

    Energy Technology Data Exchange (ETDEWEB)

    Cash, R.; Lasbennes, F.; Sercombe, R.; Seylaz, J.; Agid, Y.

    1985-08-12

    The binding of adrenergic ligands (/sup 3/H-prazosin, /sup 3/H-clonidine, /sup 3/H-dihydroalprenolol) was studied on a preparation of cerebral microvessels in the prefrontal cortex and putamen of control and Parkinsonian subjects. The adrenergic receptor density in microvessels of control patients was less than 0.5% and 3.3% respectively of the total binding. A significant decrease in the number of alpha-1 binding sites was observed on microvessels in the putamen of patients with Parkinson's disease. 22 references, 2 tables.

  16. Vestibular compensation after vestibular schwannoma surgery: normalization of the subjective visual vertical and disability.

    Science.gov (United States)

    Batuecas-Caletrio, Angel; Santacruz-Ruiz, Santiago; Muñoz-Herrera, Angel; Sousa, Pablo; Otero, Alvaro; Perez-Fernandez, Nicolas

    2013-05-01

    The degree of caloric weakness before surgery influences faster or slower recovery of patients undergoing vestibular schwannoma surgery. The Dizziness Handicap Inventory (DHI) is a good index to show the recovery of patients as it relates directly to an improvement or not of the subjective visual vertical (SVV). To evaluate the process of recovery of patients as measured by the SVV and the DHI after surgical removal of vestibular schwannoma. We studied 24 consecutive patients of the University Hospital of Salamanca who underwent vestibular schwannoma surgery. We assessed age, tumour size, degree of canalicular weakness and preoperative SVV, and their relationship with DHI and SVV at discharge and also at 1, 3 and 6 months postoperatively. Patients with lesser degrees of caloric weakness took longer to normalize SVV than those with a higher caloric weakness before surgery (p < 0.05). There was a significant correlation between DHI and improvements in SVV with time. The differences disappeared in 6 months where all patients, with greater or lesser degree of caloric weakness, had the same results.

  17. Negative emotion enhances mnemonic precision and subjective feelings of remembering in visual long-term memory.

    Science.gov (United States)

    Xie, Weizhen; Zhang, Weiwei

    2017-09-01

    Negative emotion sometimes enhances memory (higher accuracy and/or vividness, e.g., flashbulb memories). The present study investigates whether it is the qualitative (precision) or quantitative (the probability of successful retrieval) aspect of memory that drives these effects. In a visual long-term memory task, observers memorized colors (Experiment 1a) or orientations (Experiment 1b) of sequentially presented everyday objects under negative, neutral, or positive emotions induced with International Affective Picture System images. In a subsequent test phase, observers reconstructed objects' colors or orientations using the method of adjustment. We found that mnemonic precision was enhanced under the negative condition relative to the neutral and positive conditions. In contrast, the probability of successful retrieval was comparable across the emotion conditions. Furthermore, the boost in memory precision was associated with elevated subjective feelings of remembering (vividness and confidence) and metacognitive sensitivity in Experiment 2. Altogether, these findings suggest a novel precision-based account for emotional memories. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Social Identity Mapping: A procedure for visual representation and assessment of subjective multiple group memberships.

    Science.gov (United States)

    Cruwys, Tegan; Steffens, Niklas K; Haslam, S Alexander; Haslam, Catherine; Jetten, Jolanda; Dingle, Genevieve A

    2016-12-01

    In this research, we introduce Social Identity Mapping (SIM) as a method for visually representing and assessing a person's subjective network of group memberships. To provide evidence of its utility, we report validating data from three studies (two longitudinal), involving student, community, and clinical samples, together comprising over 400 participants. Results indicate that SIM is easy to use, internally consistent, with good convergent and discriminant validity. Each study also illustrates the ways that SIM can be used to address a range of novel research questions. Study 1 shows that multiple positive group memberships are a particularly powerful predictor of well-being. Study 2 shows that social support is primarily given and received within social groups and that only in-group support is beneficial for well-being. Study 3 shows that improved mental health following a social group intervention is attributable to an increase in group compatibility. In this way, the studies demonstrate the capacity for SIM to make a contribution both to the development of social-psychological theory and to its practical application. © 2016 The British Psychological Society.

  19. A Visual Analytics Approach to Structured Data Analysis to Enhance Nonproliferation and Arms Control Verification Activities

    Energy Technology Data Exchange (ETDEWEB)

    Gillen, David S.

    2014-08-07

    Analysis activities for Nonproliferation and Arms Control verification require the use of many types of data. Tabular structured data, such as Excel spreadsheets and relational databases, have traditionally been used for data mining activities, where specific queries are issued against data to look for matching results. The application of visual analytics tools to structured data enables further exploration of datasets to promote discovery of previously unknown results. This paper discusses the application of a specific visual analytics tool to datasets related to the field of Arms Control and Nonproliferation to promote the use of visual analytics more broadly in this domain. Visual analytics focuses on analytical reasoning facilitated by interactive visual interfaces (Wong and Thomas 2004). It promotes exploratory analysis of data, and complements data mining technologies where known patterns can be mined for. Also with a human in the loop, they can bring in domain knowledge and subject matter expertise. Visual analytics has not widely been applied to this domain. In this paper, we will focus on one type of data: structured data, and show the results of applying a specific visual analytics tool to answer questions in the Arms Control and Nonproliferation domain. We chose to use the T.Rex tool, a visual analytics tool developed at PNNL, which uses a variety of visual exploration patterns to discover relationships in structured datasets, including a facet view, graph view, matrix view, and timeline view. The facet view enables discovery of relationships between categorical information, such as countries and locations. The graph tool visualizes node-link relationship patterns, such as the flow of materials being shipped between parties. The matrix visualization shows highly correlated categories of information. The timeline view shows temporal patterns in data. In this paper, we will use T.Rex with two different datasets to demonstrate how interactive exploration of

  20. Visual-Motor Control in Baseball Batting

    Directory of Open Access Journals (Sweden)

    Rob Gray

    2011-05-01

    Full Text Available With margins for error of a few milliseconds and fractions of an inch it is not surprising that hitting a baseball is considered to be one of the most difficult acts in all of sports. We have been investigating this challenging behavior using a virtual baseball batting setup in which simulations of an approaching ball, pitcher, and field are combined with real-time recording of bat and limb movements. I will present evidence that baseball batting involves variable pre-programmed control in which the swing direction and movement time (MT are set prior to the initiation of the action but can take different values from swing-to-swing. This programming process utilizes both advance information (pitch history and count and optical information picked-up very early in the ball's flight (ball time to contact TTC and rotation direction. The pre-programmed value of MT is used to determine a critical value of TTC for swing initiation. Finally, because a baseball swing is an action that is occasionally interrupted online (i.e., a “check swing”, I will discuss experiments that examine when this pre-programmed action can be stopped and the sources of optical information that trigger stopping.

  1. A case-control study of visual acuity in onychocryptosis.

    LENUS (Irish Health Repository)

    Hogan, Aisling M

    2012-02-01

    BACKGROUND: There are many theories surrounding the etiology of ingrown toenails (IGTN). Few factors have been formally assessed, but it is widely accepted that a poor nail cutting technique has a causative role. AIM: To investigate the hypothesis that decreased visual acuity may lead to inadequate nail cutting and the formation of IGTN. METHODS: A prospective case-control study was performed. Near and distance visual acuity were tested on a population with IGTN (n = 19) and compared with that of an age- and sex-matched control cohort (n = 24) who underwent epidermal cyst excision in the same tertiary referral center. Comparisons of visual acuity were made between groups by Mann-Whitney U-test. Differences were taken to be significant if P < 0.05. Institutional Review Board approval was sought and granted. RESULTS: No significant difference in visual acuity (near or distance) was demonstrated between patients with IGTN and the control group (P = 0.33). CONCLUSION: Visual acuity does not appear to play a significant role in the development of IGTN.

  2. Visual Flight Control of a Quadrotor Using Bioinspired Motion Detector

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2012-01-01

    Full Text Available Motion detection in the fly is extremely fast with low computational requirements. Inspired from the fly's vision system, we focus on a real-time flight control on a miniquadrotor with fast visual feedback. In this work, an elaborated elementary motion detector (EMD is utilized to detect local optical flow. Combined with novel receptive field templates, the yaw rate of the quadrotor is estimated through a lookup table established with this bioinspired visual sensor. A closed-loop control system with the feedback of yaw rate estimated by EMD is designed. With the motion of the other degrees of freedom stabilized by a camera tracking system, the yaw-rate of the quadrotor during hovering is controlled based on EMD feedback under real-world scenario. The control performance of the proposed approach is compared with that of conventional approach. The experimental results demonstrate the effectiveness of utilizing EMD for quadrotor control.

  3. EEG topographies provide subject-specific correlates of motor control.

    Science.gov (United States)

    Pirondini, Elvira; Coscia, Martina; Minguillon, Jesus; Millán, José Del R; Van De Ville, Dimitri; Micera, Silvestro

    2017-10-16

    Electroencephalography (EEG) of brain activity can be represented in terms of dynamically changing topographies (microstates). Notably, spontaneous brain activity recorded at rest can be characterized by four distinctive topographies. Despite their well-established role during resting state, their implication in the generation of motor behavior is debated. Evidence of such a functional role of spontaneous brain activity would provide support for the design of novel and sensitive biomarkers in neurological disorders. Here we examined whether and to what extent intrinsic brain activity contributes and plays a functional role during natural motor behaviors. For this we first extracted subject-specific EEG microstates and muscle synergies during reaching-and-grasping movements in healthy volunteers. We show that, in every subject, well-known resting-state microstates persist during movement execution with similar topographies and temporal characteristics, but are supplemented by novel task-related microstates. We then show that the subject-specific microstates' dynamical organization correlates with the activation of muscle synergies and can be used to decode individual grasping movements with high accuracy. These findings provide first evidence that spontaneous brain activity encodes detailed information about motor control, offering as such the prospect of a novel tool for the definition of subject-specific biomarkers of brain plasticity and recovery in neuro-motor disorders.

  4. Symptoms of meares-irlen/visual stress syndrome in subjects diagnosed with chronic fatigue syndrome

    Directory of Open Access Journals (Sweden)

    Stephen J. Loew

    2014-01-01

    Full Text Available Algunos síntomas del Síndrome de Estrés Visual/Meares-Irlen son similares a los informados por individuos con síndrome de fatiga crónica (SFC. Se evaluó la incidencia de nueve síntomas ampliamente reconocidos de estrés visual (EV en un grupo de sujetos (n = 20 con síndrome de fatiga crónica. La presencia de cada síntoma de EV en el grupo con SFC se comparó con un grupo control de sujetos sanos (n = 46 y con un grupo de individuos (n = 14 con diagnóstico de EV, equiparables en sexo y edad. Los resultados mostraron una frecuencia en los nueve síntomas de EV en el grupo diagnosticado SFC significativamente mayor (p = 0,032-p < 0,0005 que en el grupo de comparación, con sólo dos síntomas estadísticamente menos frecuentes en el grupo SFC que en el grupo EV. El número medio de síntomas EV señalados por el grupo SFC también fue significativamente mayor que el del grupo de comparación, aunque no significativamente diferente el grupo EV. Por lo tanto, la presencia de los síntomas de EV en sujetos con diagnóstico de SFC parece ser mucho mayor que la informada, lo que puede indicar la interacción de algún factor/s subyacente/s aún no identificado/s comunes a ambas condiciones. © 2013 Asociación Española de Psicología Conductual. Publicado por Elsevier España, S.L. Todos los derechos reservados.

  5. The Effect of Concurrent Visual Feedback on Controlling Swimming Speed

    Directory of Open Access Journals (Sweden)

    Szczepan Stefan

    2016-03-01

    Full Text Available Introduction. Developing the ability to control the speed of swimming is an important part of swimming training. Maintaining a defined constant speed makes it possible for the athlete to swim economically at a low physiological cost. The aim of this study was to determine the effect of concurrent visual feedback transmitted by the Leader device on the control of swimming speed in a single exercise test. Material and methods. The study involved a group of expert swimmers (n = 20. Prior to the experiment, the race time for the 100 m distance was determined for each of the participants. In the experiment, the participants swam the distance of 100 m without feedback and with visual feedback. In both variants, the task of the participants was to swim the test distance in a time as close as possible to the time designated prior to the experiment. In the first version of the experiment (without feedback, the participants swam the test distance without receiving real-time feedback on their swimming speed. In the second version (with visual feedback, the participants followed a beam of light moving across the bottom of the swimming pool, generated by the Leader device. Results. During swimming with visual feedback, the 100 m race time was significantly closer to the time designated. The difference between the pre-determined time and the time obtained was significantly statistically lower during swimming with visual feedback (p = 0.00002. Conclusions. Concurrently transmitting visual feedback to athletes improves their control of swimming speed. The Leader device has proven useful in controlling swimming speed.

  6. Layers Of Visual Imagination And Degrees Of Subjectivity In Listening Experiences Exploring Visual Imagination In Acousmatic Composition And Listening

    OpenAIRE

    Stefano Poillucci

    2015-01-01

    Abstract Electroacoustic music especially Acousmatic is often perceived differently between listeners and a wide variety of visual images is evoked. This because of the spectromorphological qualities and the abstract reality in which this kind of music carries the listener into. In everyday life it seems that we have a natural tendency to assess and understand reality around us and to quantise how and if the perceived circumstances could affect our wellbeing. Some studies also affirm that bra...

  7. Comparison of visual outcomes and subjective visual quality after bilateral implantation of a diffractive trifocal intraocular lens and blended implantation of apodized diffractive bifocal intraocular lenses

    Directory of Open Access Journals (Sweden)

    Gundersen KG

    2016-05-01

    Full Text Available Kjell G Gundersen,1 Rick Potvin21IFocus Øyeklinikk AS, Haugesund, Norway; 2Science in Vision, Akron, NY, USAPurpose: To compare the visual acuity (VA and quality of vision between bilateral implantation of a trifocal intraocular lens (IOL and blended bifocal IOLs with an intermediate add in the dominant eye and a near add in the nondominant eye.Patients and methods: Patients with either trifocal or blended bifocal IOLs implanted were recruited after surgery. Subjects returned for a single diagnostic visit between 3 and 24 months after surgery. VA was tested at various distances, including low-contrast acuity and acuity at their preferred reading distance. A binocular defocus curve was obtained, and subjective visual function and quality of vision were evaluated.Results: Twenty-five trifocal subjects and 30 blended bifocal subjects were enrolled. There were no significant differences in low-contrast acuity, preferred reading distance, or acuity at that reading distance. Binocular vision at 4 m, 60 cm, and 40 cm was not statistically significantly different. The trifocal provided statistically significantly better visual acuity (P<0.05 at vergences from -0.5 to -1.5 D (from 2 m to 67 cm viewing distance, P<0.05. There was no statistically significant difference in the near vision subscale scores of the 39-question National Eye Institute Visual Function Questionnaire or the overall scores of the Quality of Vision questionnaire, though significantly more trifocal subjects reported that the observed visual disturbances were “bothersome” (P<0.05.Conclusion: Both lens modalities provided subjects with excellent binocular near and distance vision, with similar low rates of visual disturbances and good reported functional vision. The trifocal IOL provided significantly better intermediate VA in the viewing distance range of 2 m to 67 cm, corresponding to viewing things such as a car dashboard or grocery shelf. VA was similar between groups at

  8. Effects of vision and cognitive load on static postural control in subjects with and without patellofemoral pain syndrome.

    Science.gov (United States)

    Zeinalzadeh, Afsaneh; Talebian, Saeed; Naghdi, Soofia; Salavati, Mahyar; Nazary-Moghadam, Salman; Zeynalzadeh Ghoochani, Bahareh

    2018-04-01

    To compare the effects of vision and cognitive load on static postural control in subjects with and without patellofemoral pain syndrome (PFPS). Twenty-eight PFPS patients and 28 controls participated in the study. Postural control was assessed in isolation as well as with visual manipulation and cognitive loading on symptomatic limb. The outcome measures of postural control were quantified in terms of area, anterior-posterior (AP), medial-lateral (ML), and mean velocity (MV) of the displacements of center of pressure (COP). In addition, cognitive performance (auditory Stroop task) was measured in the forms of average reaction time and error ratio in baseline (sitting) and different postural conditions. PFPS subjects showed greater increases in area (p = 0.01), AP (p = 0.01), and ML (p = 0.05) displacements of COP in the blindfolded tasks as compared to control group. However, cognitive load did not differently affect postural control in the two groups. Although PFPS and control group had similar reaction times in the sitting position (p = 0.29), PFPS subjects had longer reaction times than healthy subjects in dual task conditions (p = 0.04). Visual inputs seem to be essential for discriminating postural control between PFPS and healthy individuals. PFPS patients biased toward decreasing cognitive performance more than healthy subjects when they perform the single leg stance and cognitive task concurrently.

  9. Visual basic application in computer hardware control and data ...

    African Journals Online (AJOL)

    Speech Recognition Technology enables text acquisition via users' dictation and knowledge gain through system dictation. In this paper the application of speech recognition technology in hardware device control and data acquisition is experimented using Visual Basic and the Speech Application Programming Interface ...

  10. Robust Control for High-Speed Visual Servoing Applications

    DEFF Research Database (Denmark)

    Ellekilde, Lars-Peter; Favrholdt, Peter; Paulin, Mads

    2007-01-01

    This paper presents a new control scheme for visual servoing applications. The approach employs quadratic optimization, and explicitly handles both joint position, velocity and acceleration limits. Contrary to existing techniques, our method does not rely on large safety margins and slow task exe...

  11. Shape of magnifiers affects controllability in children with visual impairment

    NARCIS (Netherlands)

    Liebrand-Schurink, J.; Boonstra, F.N.; Rens, G.H.M.B. van; Cillessen, A.H.N.; Meulenbroek, R.G.J.; Cox, R.F.A.

    2016-01-01

    Purpose: This study aimed to examine the controllability of cylinder-shaped and dome-shaped magnifiers in young children with visual impairment. Methods: This study investigates goal-directed arm movements in low-vision aid use (stand and dome magnifier-like object) in a group of young children with

  12. Visual control of steering in the box jellyfish Tripedalia cystophora.

    Science.gov (United States)

    Petie, Ronald; Garm, Anders; Nilsson, Dan-Eric

    2011-09-01

    Box jellyfish carry an elaborate visual system consisting of 24 eyes, which they use for driving a number of behaviours. However, it is not known how visual input controls the swimming behaviour. In this study we exposed the Caribbean box jellyfish Tripedalia cystophora to simple visual stimuli and recorded changes in their swimming behaviour. Animals were tethered in a small experimental chamber, where we could control lighting conditions. The behaviour of the animals was quantified by tracking the movements of the bell, using a high-speed camera. We found that the animals respond predictably to the darkening of one quadrant of the equatorial visual world by (1) increasing pulse frequency, (2) creating an asymmetry in the structure that constricts the outflow opening of the bell, the velarium, and (3) delaying contraction at one of the four sides of the bell. This causes the animals to orient their bell in such a way that, if not tethered, they would turn and swim away from the dark area. We conclude that the visual system of T. cystophora has a predictable effect on swimming behaviour.

  13. Shape of magnifiers affects controllability in children with visual impairment.

    Science.gov (United States)

    Liebrand-Schurink, Joyce; Boonstra, F Nienke; van Rens, Ger H M B; Cillessen, Antonius H N; Meulenbroek, Ruud G J; Cox, Ralf F A

    2016-12-01

    This study aimed to examine the controllability of cylinder-shaped and dome-shaped magnifiers in young children with visual impairment. This study investigates goal-directed arm movements in low-vision aid use (stand and dome magnifier-like object) in a group of young children with visual impairment (n = 56) compared to a group of children with normal sight (n = 66). Children with visual impairment and children with normal sight aged 4-8 years executed two types of movements (cyclic and discrete) in two orientations (vertical or horizontal) over two distances (10 cm and 20 cm) with two objects resembling the size and shape of regularly prescribed stand and dome magnifiers. The visually impaired children performed slower movements than the normally sighted children. In both groups, the accuracy and speed of the reciprocal aiming movements improved significantly with age. Surprisingly, in both groups, the performance with the dome-shaped object was significantly faster (in the 10 cm condition and 20 cm condition with discrete movements) and more accurate (in the 20 cm condition) than with the stand-shaped object. From a controllability perspective, this study suggests that it is better to prescribe dome-shaped than cylinder-shaped magnifiers to young children with visual impairment. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  14. Efficacy of Visual-Acoustic Biofeedback Intervention for Residual Rhotic Errors: A Single-Subject Randomization Study

    Science.gov (United States)

    Byun, Tara McAllister

    2017-01-01

    Purpose: This study documented the efficacy of visual-acoustic biofeedback intervention for residual rhotic errors, relative to a comparison condition involving traditional articulatory treatment. All participants received both treatments in a single-subject experimental design featuring alternating treatments with blocked randomization of…

  15. Experimental Study on Subjective Evaluation for Visual Information by Event-Related Potential: Evaluation of Food and its Appearance

    Directory of Open Access Journals (Sweden)

    Motoshi Tanaka

    2011-10-01

    Full Text Available Evaluating subjective judgment for visual information by event-related potential (ERP quantitatively was studied. Pictures of food were displayed as visual information. And P300 component of the ERP was focused. The P300 is related to cognition and/or judgment, and has the latency in the range from 250 to 500 ms. As a fundamental study, the ERP was measured when subjectively judging food and its appearance by three-grade scale with the opinion “like”, “favorite” and “more favorite”. Sushi and cooked rice were selected as typical foods. And bottles which had almost the same shape without labels, but the colors were different, were used for an opinion test of the food appearance. Five pictures for each food were chosen by subjects before measurements. And no food which the subjects disliked was chosen because almost the same P300 amplitude appeared in both cases where the subjects judged as “like” and “dislike”. In results, the P300 amplitude by each subject's opinion was different, and the P300 area (surrounded by ERP waveform from the latency 250 to 500 ms became larger when the subjects judged as “more favorite”. These results indicate the feasibility of quantitative evaluation of subjective judgment by the ERP.

  16. Software para avaliação da subjetiva vertical visual: um estudo transversal observacional Software for subjective visual vertical assessment: an observational cross-sectional study

    Directory of Open Access Journals (Sweden)

    Theo Zeferino Pavan

    2012-10-01

    Full Text Available A orientação espacial em relação ao eixo gravitacional é de suma importância para a manu tenção da postura, marcha e para a maioria das atividades motoras realizadas pelo ser humano. A subjetiva vertical visual é um exame que avalia a percepção individual de verticalidade. OBJETIVOS: Os objetivos deste estudo foram: (1 desenvolver um sistema virtual para avaliar a subjetiva vertical visual, (2 produzir uma ferramenta simples para a prática clínica e (3 medir os valores da subjetiva vertical visual em indivíduos saudáveis usando a nova ferramenta. Forma de estudo: estudo obser vacional transversal. MÉTODO: Trinta voluntários saudáveis realizaram a subjetiva vertical visual em ambas as condições, estática e dinâmica. O exame consistia em ajustar uma linha virtual na posição vertical usando o mouse do computador. Na condição estática, a linha virtual foi projetada em uma tela branca. Na condição dinâmica, círculos pretos giravam no sentido horário e anti-horário. Seis medidas foram feitas e o desvio médio em relação a vertical real, calculado. RESULTADOS: Os desvios médios da subjetiva vertical visual foram: estática -0,372º ± 1,21; dinâmica sentido horário 1,53º ± 1,80 e dinâmica sentido anti-horário -1,11º ± 2,46. CONCLUSÃO: Este software mostrou ser prático e preciso para ser inserido na rotina de exames clínicos.Spatial orientation in relation to the gravitational axis is significantly important for the maintenance of the posture, gait and for most of the human's motor activities. The subjective visual vertical exam evaluates the individual's perception of vertical orientation. OBJECTIVES: The aims of this study were (1 to develop a virtual system to evaluate the subjective visual vertical exam, (2 to provide a simple tool to clinical practice and (3 to assess the subjective visual vertical values of healthy subjects using the new software. Study Design: observational cross-sectional study

  17. Influence of age, spatial memory, and ocular fixation on localization of auditory, visual, and bimodal targets by human subjects.

    Science.gov (United States)

    Dobreva, Marina S; O'Neill, William E; Paige, Gary D

    2012-12-01

    A common complaint of the elderly is difficulty identifying and localizing auditory and visual sources, particularly in competing background noise. Spatial errors in the elderly may pose challenges and even threats to self and others during everyday activities, such as localizing sounds in a crowded room or driving in traffic. In this study, we investigated the influence of aging, spatial memory, and ocular fixation on the localization of auditory, visual, and combined auditory-visual (bimodal) targets. Head-restrained young and elderly subjects localized targets in a dark, echo-attenuated room using a manual laser pointer. Localization accuracy and precision (repeatability) were quantified for both ongoing and transient (remembered) targets at response delays up to 10 s. Because eye movements bias auditory spatial perception, localization was assessed under target fixation (eyes free, pointer guided by foveal vision) and central fixation (eyes fixed straight ahead, pointer guided by peripheral vision) conditions. Spatial localization across the frontal field in young adults demonstrated (1) horizontal overshoot and vertical undershoot for ongoing auditory targets under target fixation conditions, but near-ideal horizontal localization with central fixation; (2) accurate and precise localization of ongoing visual targets guided by foveal vision under target fixation that degraded when guided by peripheral vision during central fixation; (3) overestimation in horizontal central space (±10°) of remembered auditory, visual, and bimodal targets with increasing response delay. In comparison with young adults, elderly subjects showed (1) worse precision in most paradigms, especially when localizing with peripheral vision under central fixation; (2) greatly impaired vertical localization of auditory and bimodal targets; (3) increased horizontal overshoot in the central field for remembered visual and bimodal targets across response delays; (4) greater vulnerability to

  18. The reproducibility of binocular pattern reversal visual evoked potentials: a single subject design.

    Science.gov (United States)

    Mellow, Tessa B; Liasis, Alki; Lyons, Ruth; Thompson, Dorothy A

    2011-06-01

    This study aimed to investigate the within-participant variability over time of both amplitude and peak latency measures of pattern reversal visual evoked potentials (pVEPs). As a large number of factors are known to contribute to the variability of the pVEPs (such as fixation instability and drowsiness), testing was conducted in controlled conditions with two co-operative participants. PVEPs were recorded during 24 sessions, over an eight-week period using the same equipment and recording settings. The participants viewed a plasma monitor binocularly from a distance of 1 meter. High contrast (97%), black and white checks of side subtense 50', 25', and 12.5' pattern reversed 3/s in a 28 degree test field. The different sized checks were presented in a pseudo-random order. Three runs, each of 100 trials, were acquired to each stimulus from an active electrode placed at Oz referred to aFz. The amplitude of N80-P100 and the latency of P100 were measured. P100 amplitude and latency were stable across sessions and did not depend upon the order of check size presentation. As expected, variation in amplitude was greater than peak latency. The coefficients of variation for different check sizes and participants were 9-14% for pVEP amplitude, but only 1-2% for P100 latency.

  19. Gain control in the visual thalamus during perception and cognition.

    Science.gov (United States)

    Saalmann, Yuri B; Kastner, Sabine

    2009-08-01

    The thalamus has traditionally been thought to passively relay sensory information to the cortex. By showing that responses in visual thalamus are modulated by perceptual and cognitive tasks, recent fMRI and physiology studies have helped revise this view. The modulatory input to the visual thalamus derives from functionally distinct cortical and subcortical feedback pathways. These pathways enable the lateral geniculate nucleus and pulvinar to regulate the information transmitted to cortical areas according to cognitive requirements. Emerging evidence suggests that such regulation involves changing the degree of synchrony between neurons as well as changing the magnitude of thalamic activity. These findings support a role for the thalamus that extends as far as contributing to the control of visual attention and awareness.

  20. Subjective craving and event-related brain response to olfactory and visual chocolate cues in binge-eating and healthy individuals

    Science.gov (United States)

    Wolz, I.; Sauvaget, A.; Granero, R.; Mestre-Bach, G.; Baño, M.; Martín-Romera, V.; Veciana de las Heras, M.; Jiménez-Murcia, S.; Jansen, A.; Roefs, A.; Fernández-Aranda, F.

    2017-01-01

    High-sugar/high-fat foods are related to binge-eating behaviour and especially people with low inhibitory control may encounter elevated difficulties to resist their intake. Incentive sensitization to food-related cues might lead to increased motivated attention towards these stimuli and to cue-induced craving. To investigate the combined influence of olfactory and visual stimuli on craving, inhibitory control and motivated attention, 20 healthy controls and 19 individuals with binge-eating viewed chocolate and neutral pictures, primed by chocolate or neutral odours. Subjective craving and electroencephalogram activity were recorded during the task. N2 and Late Positive Potential (LPP) amplitudes were analysed. Patients reported higher craving than controls. Subjective craving, N2 and LPP amplitudes were higher for chocolate versus neutral pictures. Patients showed a higher relative increase in N2 amplitudes to chocolate versus neutral pictures than controls. Chocolate images induced significant increases in craving, motivated attention and measures of cognitive control. Chocolate odour might potentiate the craving response to visual stimuli, especially in patients with binge-eating. PMID:28155875

  1. Subjective craving and event-related brain response to olfactory and visual chocolate cues in binge-eating and healthy individuals.

    Science.gov (United States)

    Wolz, I; Sauvaget, A; Granero, R; Mestre-Bach, G; Baño, M; Martín-Romera, V; Veciana de Las Heras, M; Jiménez-Murcia, S; Jansen, A; Roefs, A; Fernández-Aranda, F

    2017-02-03

    High-sugar/high-fat foods are related to binge-eating behaviour and especially people with low inhibitory control may encounter elevated difficulties to resist their intake. Incentive sensitization to food-related cues might lead to increased motivated attention towards these stimuli and to cue-induced craving. To investigate the combined influence of olfactory and visual stimuli on craving, inhibitory control and motivated attention, 20 healthy controls and 19 individuals with binge-eating viewed chocolate and neutral pictures, primed by chocolate or neutral odours. Subjective craving and electroencephalogram activity were recorded during the task. N2 and Late Positive Potential (LPP) amplitudes were analysed. Patients reported higher craving than controls. Subjective craving, N2 and LPP amplitudes were higher for chocolate versus neutral pictures. Patients showed a higher relative increase in N2 amplitudes to chocolate versus neutral pictures than controls. Chocolate images induced significant increases in craving, motivated attention and measures of cognitive control. Chocolate odour might potentiate the craving response to visual stimuli, especially in patients with binge-eating.

  2. Robust Visual Control of Parallel Robots under Uncertain Camera Orientation

    Directory of Open Access Journals (Sweden)

    Miguel A. Trujano

    2012-10-01

    Full Text Available This work presents a stability analysis and experimental assessment of a visual control algorithm applied to a redundant planar parallel robot under uncertainty in relation to camera orientation. The key feature of the analysis is a strict Lyapunov function that allows the conclusion of asymptotic stability without invoking the Barbashin-Krassovsky-LaSalle invariance theorem. The controller does not rely on velocity measurements and has a structure similar to a classic Proportional Derivative control algorithm. Experiments in a laboratory prototype show that uncertainty in camera orientation does not significantly degrade closed-loop performance.

  3. Effects of repeated snowboard exercise in virtual reality with time lags of visual scene behind body rotation on head stability and subjective slalom run performance in healthy young subjects.

    Science.gov (United States)

    Wada, Yoshiro; Nishiike, Suetaka; Kitahara, Tadashi; Yamanaka, Toshiaki; Imai, Takao; Ito, Taeko; Sato, Go; Matsuda, Kazunori; Kitamura, Yoshiaki; Takeda, Noriaki

    2016-11-01

    After repeated snowboard exercises in the virtual reality (VR) world with increasing time lags in trials 3-8, it is suggested that the adaptation to repeated visual-vestibulosomatosensory conflict in the VR world improved dynamic posture control and motor performance in the real world without the development of motion sickness. The VR technology was used and the effects of repeated snowboard exercise examined in the VR world with time lags between visual scene and body rotation on the head stability and slalom run performance during exercise in healthy subjects. Forty-two healthy young subjects participated in the study. After trials 1 and 2 of snowboard exercise in the VR world without time lag, trials 3-8 were conducted with 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 s time lags of the visual scene that the computer creates behind board rotation, respectively. Finally, trial 9 was conducted without time lag. Head linear accelerations and subjective slalom run performance were evaluated. The standard deviations of head linear accelerations in inter-aural direction were significantly increased in trial 8, with a time lag of 0.6 s, but significantly decreased in trial 9 without a time lag, compared with those in trial 2 without a time lag. The subjective scores of slalom run performance were significantly decreased in trial 8, with a time lag of 0.6 s, but significantly increased in trial 9 without a time lag, compared with those in trial 2 without a time lag. Motion sickness was not induced in any subjects.

  4. Visual art as means and subject of instruction: Various approaches and strategies

    National Research Council Canada - National Science Library

    Pavlovic, Marija

    2016-01-01

    The paper looks at various approaches and strategies of using visual art in nursery schools and elementary schools in accordance with theory-based concepts of the abilities and interests of children in these age groups...

  5. Visual and somatosensory information about object shape control manipulative fingertip forces.

    Science.gov (United States)

    Jenmalm, P; Johansson, R S

    1997-06-01

    We investigated the importance of visual versus somatosensory information for the adaptation of the fingertip forces to object shape when humans used the tips of the right index finger and thumb to lift a test object. The angle of the two flat grip surfaces in relation to the vertical plane was changed between trials from -40 to 30 degrees. At 0 degrees the two surfaces were parallel, and at positive and negative angles the object tapered upward and downward, respectively. Subjects automatically adapted the balance between the horizontal grip force and the vertical lift force to the object shape and thereby maintained a rather constant safety margin against frictional slips, despite the huge variation in finger force requirements. Subjects used visual cues to adapt force to object shape parametrically in anticipation of the force requirements imposed once the object was contacted. In the absence of somatosensory information from the digits, sighted subjects still adapted the force coordination to object shape, but without vision and somatosensory inputs the performance was severely impaired. With normal digital sensibility, subjects adapted the force coordination to object shape even without vision. Shape cues obtained by somatosensory mechanisms were expressed in the motor output about 0. 1 sec after contact. Before this point in time, memory of force coordination used in the previous trial controlled the force output. We conclude that both visual and somatosensory inputs can be used in conjunction with sensorimotor memories to adapt the force output to object shape automatically for grasp stability.

  6. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions

    Science.gov (United States)

    Honeine, Jean-Louis; Schieppati, Marco

    2014-01-01

    Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system (CNS) continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a) subtract or integrate sensory inputs; (b) move from allocentric to egocentric reference or vice versa; and (c) adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1–2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift) in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training devices

  7. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions

    Directory of Open Access Journals (Sweden)

    Jean-Louis eHoneine

    2014-10-01

    Full Text Available Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a subtract or integrate sensory inputs, (b move from allocentric to egocentric reference or vice versa, and (c adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1-2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training

  8. Simple control-theoretic models of human steering activity in visually guided vehicle control

    Science.gov (United States)

    Hess, Ronald A.

    1991-01-01

    A simple control theoretic model of human steering or control activity in the lateral-directional control of vehicles such as automobiles and rotorcraft is discussed. The term 'control theoretic' is used to emphasize the fact that the model is derived from a consideration of well-known control system design principles as opposed to psychological theories regarding egomotion, etc. The model is employed to emphasize the 'closed-loop' nature of tasks involving the visually guided control of vehicles upon, or in close proximity to, the earth and to hypothesize how changes in vehicle dynamics can significantly alter the nature of the visual cues which a human might use in such tasks.

  9. The Effect of Visual Stimuli on Stability and Complexity of Postural Control

    Directory of Open Access Journals (Sweden)

    Haizhen Luo

    2018-02-01

    Full Text Available Visual input could benefit balance control or increase postural sway, and it is far from fully understanding the effect of visual stimuli on postural stability and its underlying mechanism. In this study, the effect of different visual inputs on stability and complexity of postural control was examined by analyzing the mean velocity (MV, SD, and fuzzy approximate entropy (fApEn of the center of pressure (COP signal during quiet upright standing. We designed five visual exposure conditions: eyes-closed, eyes-open (EO, and three virtual reality (VR scenes (VR1–VR3. The VR scenes were a limited field view of an optokinetic drum rotating around yaw (VR1, pitch (VR2, and roll (VR3 axes, respectively. Sixteen healthy subjects were involved in the experiment, and their COP trajectories were assessed from the force plate data. MV, SD, and fApEn of the COP in anterior–posterior (AP, medial–lateral (ML directions were calculated. Two-way analysis of variance with repeated measures was conducted to test the statistical significance. We found that all the three parameters obtained the lowest values in the EO condition, and highest in the VR3 condition. We also found that the active neuromuscular intervention, indicated by fApEn, in response to changing the visual exposure conditions were more adaptive in AP direction, and the stability, indicated by SD, in ML direction reflected the changes of visual scenes. MV was found to capture both instability and active neuromuscular control dynamics. It seemed that the three parameters provided compensatory information about the postural control in the immersive virtual environment.

  10. Complex regional pain syndrome (CRPS) or continuous unilateral distal experimental pain stimulation in healthy subjects does not bias visual attention towards one hemifield.

    Science.gov (United States)

    Filippopulos, Filipp M; Grafenstein, Jessica; Straube, Andreas; Eggert, Thomas

    2015-11-01

    In natural life pain automatically draws attention towards the painful body part suggesting that it interacts with different attentional mechanisms such as visual attention. Complex regional pain syndrome (CRPS) patients who typically report on chronic distally located pain of one extremity may suffer from so-called neglect-like symptoms, which have also been linked to attentional mechanisms. The purpose of the study was to further evaluate how continuous pain conditions influence visual attention. Saccade latencies were recorded in two experiments using a common visual attention paradigm whereby orientating saccades to cued or uncued lateral visual targets had to be performed. In the first experiment saccade latencies of healthy subjects were measured under two conditions: one in which continuous experimental pain stimulation was applied to the index finger to imitate a continuous pain situation, and one without pain stimulation. In the second experiment saccade latencies of patients suffering from CRPS were compared to controls. The results showed that neither the continuous experimental pain stimulation during the experiment nor the chronic pain in CRPS led to an unilateral increase of saccade latencies or to a unilateral increase of the cue effect on latency. The results show that unilateral, continuously applied pain stimuli or chronic pain have no or only very limited influence on visual attention. Differently from patients with visual neglect, patients with CRPS did not show strong side asymmetries of saccade latencies or of cue effects on saccade latencies. Thus, neglect-like clinical symptoms of CRPS patients do not involve the allocation of visual attention.

  11. Response of different lines and cultivars of rice subjected to low temperatures under controlled conditions

    Directory of Open Access Journals (Sweden)

    Sandra H Díaz Solís

    2017-01-01

    Full Text Available Rice (Oryza sativa L. is the most important food crop in the world and primary source of food for more than a third of the population. The low temperatures are among the main abiotic stresses that affect the yield of this cereal. The objective of this work was to determinate the response of different lines and cultivars of rice in seedling state to low temperature stress under controlled conditions. 172 lines and cultivars were studied. It were subjected to 5 0C for 24 hours, when the plants were about three to four leaves. The evaluations were conducted by measured of chlorophyll fluorescence and visually. A wide range of response was obtained, which indicated a high allelic diversity for the low temperatures sensitivity in the studied germplasm. A group of 30 cultivars responded more favorably to the cold and the most prominent cultivars showed Fv/Fm values between 0.80 and 0.89. A significant relationship between visual evaluation and chlorophyll fluorescence was found. The correlation coefficient revealed a moderately strong relationship between both variables. Tolerant plant materials were more consistently identified. However, the dispersion between methods increased to more susceptible cultivars.   Keywords: cold tolerance, chlorophyll fluorescence, Oryza sativa, visual evaluation

  12. Visual Spatial Attention Training Improve Spatial Attention and Motor Control for Unilateral Neglect Patients.

    Science.gov (United States)

    Wang, Wei; Ji, Xiangtong; Ni, Jun; Ye, Qian; Zhang, Sicong; Chen, Wenli; Bian, Rong; Yu, Cui; Zhang, Wenting; Shen, Guangyu; Machado, Sergio; Yuan, Tifei; Shan, Chunlei

    2015-01-01

    To compare the effect of visual spatial training on the spatial attention to that on motor control and to correlate the improvement of spatial attention to motor control progress after visual spatial training in subjects with unilateral spatial neglect (USN). 9 cases with USN after right cerebral stroke were randomly divided into Conventional treatment group + visual spatial attention and Conventional treatment group. The Conventional treatment group + visual spatial attention received conventional rehabilitation therapy (physical and occupational therapy) and visual spatial attention training (optokinetic stimulation and right half-field eye patching). The Conventional treatment group was only treated with conventional rehabilitation training (physical and occupational therapy). All patients were assessed by behavioral inattention test (BIT), Fugl-Meyer Assessment of motor function (FMA), equilibrium coordination test (ECT) and non-equilibrium coordination test (NCT) before and after 4 weeks treatment. Total scores in both groups (without visual spatial attention/with visual spatial attention) improved significantly (BIT: P=0.021/P=0.000, d=1.667/d=2.116, power=0.69/power=0.98, 95%CI[-0.8839,45.88]/95%CI=[16.96,92.64]; FMA: P=0.002/P=0.000, d=2.521/d=2.700, power=0.93/power=0.98, 95%CI[5.707,30.79]/95%CI=[16.06,53.94]; ECT: P=0.002/ P=0.000, d=2.031/d=1.354, power=0.90/power=0.17, 95%CI[3.380,42.61]/95%CI=[-1.478,39.08]; NCT: P=0.013/P=0.000, d=1.124/d=1.822, power=0.41/power=0.56, 95%CI[-7.980,37.48]/95%CI=[4.798,43.60],) after treatment. Among the 2 groups, the group with visual spatial attention significantly improved in BIT (P=0.003, d=3.103, power=1, 95%CI[15.68,48.92]), FMA of upper extremity (P=0.006, d=2.771, power=1, 95%CI[5.061,20.14]) and NCT (P=0.010, d=2.214, power=0.81-0.90, 95%CI[3.018,15.88]). Correlative analysis shows that the change of BIT scores is positively correlated to the change of FMA total score (r=0.77, Pmotor control functions in

  13. Effect of sleep deprivation and driving duration on the useful visual field in younger and older subjects during simulator driving.

    Science.gov (United States)

    Rogé, Joceline; Pébayle, Thierry; El Hannachi, Saida; Muzet, Alain

    2003-06-01

    Nine older subjects (40-51 years) and 10 younger subjects (18-30 years) took part in two one-hour driving sessions. They performed a very monotonous task during which they had to follow a vehicle either after a complete night of sleep or after one night of sleep deprivation. While driving their useful visual field was assessed by introducing signals that would appear on the whole road scene. The analysis of the data indicates that the ability to process peripheral signals deteriorates with age, driving duration and sleep deprivation. However, the effects of these three variables on the peripheral visual ability are not similar in a dual task. The driver's useful visual field changes with age and prolongation of the monotonous driving activity according to a tunnel vision phenomenon. On the other hand, a sleep debt deteriorates the useful visual field according to a general interference phenomenon. These results are discussed in terms of decrease in the level of arousal and increase of fatigue.

  14. Effects of visual demonstration, verbal instructions, and prompted verbal descriptions on the performance of human subjects in conditional discriminations

    Science.gov (United States)

    Ribes-Iñesta, Emilio; Cepeda, Ma. Luisa; Hickman, Hortencia; Moreno, Diana; Peñalosa, Eduardo

    1992-01-01

    A study was conducted to confirm prior results concerning the role of prompted verbal descriptions of visually demonstrated stimulus relations in the acquisition and transfer of identity, difference, and similarity-matching relations (Ribes et al., 1988). Four groups of human adults were trained with these three matching relations under four different procedures: (1) visual demonstration without response requirement, (2) verbal instructions, (3) visual demonstration plus prompted verbal description, and (4) visual demonstration plus verbal instructions. These procedures were presented at the beginning of the training period before subjects could respond to the experimental task. Although most subjects in the four groups acquired the conditional discrimination under the three matching relations, only those in the two instruction-related groups showed some intramodal and extramodal transfer in tests with stimuli that had not been used in training. These results suggest the importance of measuring extra-situational and trans-situational generalization, and raise the need to distinguish between formal and functional verbal factors in the regulation of human behavior. ImagesFig. 3Fig. 4 PMID:22477044

  15. Clinical research, comparison of the subjective visual function in patients with epiphora and patients with second-eye cataract.

    Science.gov (United States)

    Kafil-Hussain, Namir; Khooshebah, Ramona

    2005-03-01

    To assess the subjective visual disability of patients with epiphora and to compare the results with that of patients waiting for second eye cataract surgery. A prospective, randomised, questionnaire-based study. Forty-six patients with epiphora listed for dacryocystorhinostomy and 50 patients having second eye cataract extraction were enrolled. A questionnaire focusing on functional visual disability in daily life and based on VF-14 was completed for each participant. Eighty-six percent of patients with epiphora and 41% of second-eye cataracts had difficulty reading small print (P vs. 42%) (P watching television (63.1% vs. 19%) (P vs. 10%) (P reading signs (39.1% vs. 4%) (P < 0.05), respectively. There is widespread recognition of the effect of cataract on visual function. This has resulted in substantial government funding to improve access to cataract surgery. In comparison, epiphora is rarely considered as a significant cause of visual disability. This study suggests that patients with epiphora suffer the same if not more of a visual handicap than patients awaiting second eye cataract surgery.

  16. Subjective Perception of Visual Distortions or Scotomas in Individuals with Retinitis Pigmentosa

    Science.gov (United States)

    Wittich, Walter; Watanabe, Donald H.; Kapusta, Michael A.; Overbury, Olga

    2011-01-01

    It is often assumed that persons who develop ocular disease have some form of visual experience that makes them aware of their deficits. However, in the case of peripheral field loss or decreasing vision in dim lighting, as in retinitis pigmentosa, for example, symptoms are more obscure and may not be as easily identified by the persons who have…

  17. Visual cortex activity predicts subjective experience after reading books with colored letters

    NARCIS (Netherlands)

    Colizoli, O.; Murre, J.M.J.; Scholte, H.S.; van Es, D.M.; Knapen, T.; Rouw, R.

    2016-01-01

    One of the most astonishing properties of synesthesia is that the evoked concurrent experiences are perceptual. Is it possible to acquire similar effects after learning cross-modal associations that resemble synesthetic mappings? In this study, we examine whether brain activation in early visual

  18. Human eye visual hyperacuity: Controlled diffraction for image resolution improvement

    Science.gov (United States)

    Lagunas, A.; Domínguez, O.; Martinez-Conde, S.; Macknik, S. L.; Del-Río, C.

    2017-09-01

    The Human Visual System appears to be using a low number of sensors for image capturing, and furthermore, regarding the physical dimensions of cones—photoreceptors responsible for the sharp central vision—we may realize that these sensors are of a relatively small size and area. Nonetheless, the human eye is capable of resolving fine details thanks to visual hyperacuity and presents an impressive sensitivity and dynamic range when set against conventional digital cameras of similar characteristics. This article is based on the hypothesis that the human eye may be benefiting from diffraction to improve both image resolution and acquisition process. The developed method involves the introduction of a controlled diffraction pattern at an initial stage that enables the use of a limited number of sensors for capturing the image and makes possible a subsequent post-processing to improve the final image resolution.

  19. Control of humanoid robot via motion-onset visual evoked potentials

    Directory of Open Access Journals (Sweden)

    Wei eLi

    2015-01-01

    Full Text Available This paper investigates controlling humanoid robot behavior via motion-onset specific N200 potentials. In this study, N200 potentials are induced by moving a blue bar through robot images intuitively representing robot behaviors to be controlled with mind. We present the individual impact of each subject on N200 potentials and discuss how to deal with individuality to obtain a high accuracy. The study results document the off-line average accuracy of 93% for hitting targets across over five subjects, so we use this major component of the motion-onset visual evoked potential (mVEP to code people’s mental activities and to perform two types of on-line operation tasks: navigating a humanoid robot in an office environment with an obstacle and picking-up an object. We discuss the factors that affect the on-line control success rate and the total time for completing an on-line operation task.

  20. Coherence and interlimb force control: Effects of visual gain.

    Science.gov (United States)

    Kang, Nyeonju; Cauraugh, James H

    2018-01-11

    Neural coupling across hemispheres and homologous muscles often appears during bimanual motor control. Force coupling in a specific frequency domain may indicate specific bimanual force coordination patterns. This study investigated coherence on pairs of bimanual isometric index finger force while manipulating visual gain and task asymmetry conditions. We used two visual gain conditions (low and high gain = 8 and 512 pixels/N), and created task asymmetry by manipulating coefficient ratios imposed on the left and right index finger forces (0.4:1.6; 1:1; 1.6:0.4, respectively). Unequal coefficient ratios required different contributions from each hand to the bimanual force task resulting in force asymmetry. Fourteen healthy young adults performed bimanual isometric force control at 20% of their maximal level of the summed force of both fingers. We quantified peak coherence and relative phase angle between hands at 0-4, 4-8, and 8-12 Hz, and estimated a signal-to-noise ratio of bimanual forces. The findings revealed higher peak coherence and relative phase angle at 0-4 Hz than at 4-8 and 8-12 Hz for both visual gain conditions. Further, peak coherence and relative phase angle values at 0-4 Hz were larger at the high gain than at the low gain. At the high gain, higher peak coherence at 0-4 Hz collapsed across task asymmetry conditions significantly predicted greater signal-to-noise ratio. These findings indicate that a greater level of visual information facilitates bimanual force coupling at a specific frequency range related to sensorimotor processing. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Intelligent Control Wheelchair Using a New Visual Joystick

    Directory of Open Access Journals (Sweden)

    Yassine Rabhi

    2018-01-01

    Full Text Available A new control system of a hand gesture-controlled wheelchair (EWC is proposed. This smart control device is suitable for a large number of patients who cannot manipulate a standard joystick wheelchair. The movement control system uses a camera fixed on the wheelchair. The patient’s hand movements are recognized using a visual recognition algorithm and artificial intelligence software; the derived corresponding signals are thus used to control the EWC in real time. One of the main features of this control technique is that it allows the patient to drive the wheelchair with a variable speed similar to that of a standard joystick. The designed device “hand gesture-controlled wheelchair” is performed at low cost and has been tested on real patients and exhibits good results. Before testing the proposed control device, we have created a three-dimensional environment simulator to test its performances with extreme security. These tests were performed on real patients with diverse hand pathologies in Mohamed Kassab National Institute of Orthopedics, Physical and Functional Rehabilitation Hospital of Tunis, and the validity of this intelligent control system had been proved.

  2. Visuomotor discordance during visually-guided hand movement in virtual reality modulates sensorimotor cortical activity in healthy and hemiparetic subjects.

    Science.gov (United States)

    Tunik, Eugene; Saleh, Soha; Adamovich, Sergei V

    2013-03-01

    We investigated neural effects of visuomotor discordances during visually-guided finger movements. A functional magnetic resonance imaging (fMRI)-compatible data glove was used to actuate (in real-time) virtual hand models shown on a display in first person perspective. In Experiment 1, we manipulated virtual hand motion to simulate either hypometric or unintentional (actuation of a mismatched finger) feedback of sequential finger flexion in healthy subjects. Analysis of finger motion revealed no significant differences in movement behavior across conditions, suggesting that between-condition differences in brain activity could only be attributed to varying modes of visual feedback rather than motor output. Hypometric feedback and mismatched finger feedback (relative to veridical) were associated with distinct activation. Hypometric feedback was associated with activation in the contralateral motor cortex. Mismatched feedback was associated with activation in bilateral ventral premotor, left dorsal premotor, and left occipitotemporal cortex. The time it took the subject to evaluate visuomotor discordance was positively correlated with activation in bilateral supplementary motor area, bilateral insula, right postcentral gyrus, bilateral dorsal premotor areas, and bilateral posterior parietal lobe. In Experiment 2, we investigated the effects of hypo- and hypermetric visual feedback in three stroke subjects. We observed increased activation of ipsilesional motor cortex in both hypometric and hypermetric feedback conditions. Our data indicate that manipulation of visual feedback of one's own hand movement may be used to facilitate activity in select brain networks. We suggest that these effects can be exploited in neurorehabilition to enhance the processes of brain reorganization after injury and, specifically, might be useful in aiding recovery of hand function in patients during virtual reality-based training.

  3. Development of Robust Behaviour Recognition for an at-Home Biomonitoring Robot with Assistance of Subject Localization and Enhanced Visual Tracking

    Directory of Open Access Journals (Sweden)

    Nevrez Imamoglu

    2014-01-01

    Full Text Available Our research is focused on the development of an at-home health care biomonitoring mobile robot for the people in demand. Main task of the robot is to detect and track a designated subject while recognizing his/her activity for analysis and to provide warning in an emergency. In order to push forward the system towards its real application, in this study, we tested the robustness of the robot system with several major environment changes, control parameter changes, and subject variation. First, an improved color tracker was analyzed to find out the limitations and constraints of the robot visual tracking considering the suitable illumination values and tracking distance intervals. Then, regarding subject safety and continuous robot based subject tracking, various control parameters were tested on different layouts in a room. Finally, the main objective of the system is to find out walking activities for different patterns for further analysis. Therefore, we proposed a fast, simple, and person specific new activity recognition model by making full use of localization information, which is robust to partial occlusion. The proposed activity recognition algorithm was tested on different walking patterns with different subjects, and the results showed high recognition accuracy.

  4. Image size invariant visual cryptography for general access structures subject to display quality constraints.

    Science.gov (United States)

    Lee, Kai-Hui; Chiu, Pei-Ling

    2013-10-01

    Conventional visual cryptography (VC) suffers from a pixel-expansion problem, or an uncontrollable display quality problem for recovered images, and lacks a general approach to construct visual secret sharing schemes for general access structures. We propose a general and systematic approach to address these issues without sophisticated codebook design. This approach can be used for binary secret images in non-computer-aided decryption environments. To avoid pixel expansion, we design a set of column vectors to encrypt secret pixels rather than using the conventional VC-based approach. We begin by formulating a mathematic model for the VC construction problem to find the column vectors for the optimal VC construction, after which we develop a simulated-annealing-based algorithm to solve the problem. The experimental results show that the display quality of the recovered image is superior to that of previous papers.

  5. Students with visual impairments in Israel: quality of life as a subjective experience.

    Science.gov (United States)

    Hess, Itay

    2011-01-01

    The present paper is based on research that investigated the quality of life of students with visual impairments, included in the regular education system, according to their own perceptions as reported in individual open interviews. The research comprised 19 students between the ages of 14 and 19 years. The main findings revealed three major themes: life in school with a focus on teachers' behavior towards the pupil; peers' reactions and the impact of stigma; family coping with the disability. Mixed feelings appeared in the first two themes. Regarding their teachers, the students reported support while at the same time they also felt a lack of sincere respect. Concerning peers, students felt that stigma affected their friendship behavior. Finally, most reports indicated satisfaction with the family bonds. Yet, there is almost no direct reference to the visual problem.

  6. Acute effect of whole body vibration on postural control in congenitally blind subjects: a preliminary evidence.

    Science.gov (United States)

    di Cagno, Alessandra; Giombini, Arrigo; Iuliano, Enzo; Moffa, Stefano; Caliandro, Tiziana; Parisi, Attilio; Borrione, Paolo; Calcagno, Giuseppe; Fiorilli, Giovanni

    2017-07-11

    The purpose of this study was to investigate the acute effects of whole body vibration at optimal frequency, on postural control in blind subjects. Twenty-four participants, 12 congenital blind males (Experimental Group), and 12 non-disabled males with no visual impairment (Control Groups) were recruited. The area of the ellipse and the total distance of the center of pressure displacements, as postural control parameters, were evaluated at baseline (T0), immediately after the vibration (T1), after 10 min (T10) and after 20 min (T20). Whole body vibration protocol consisted into 5 sets of 1 min for each vibration, with 1 min rest between each set on a vibrating platform. The total distance of center of pressure showed a significant difference (p static balance were found after an acute bout of whole body vibration at optimal frequency in blind subjects and, consequently, whole body vibration may be considered as a safe application in individuals who are blind.

  7. Sonomyography (SMG) control for powered prosthetic hand: a study with normal subjects.

    Science.gov (United States)

    Chen, Xin; Zheng, Yong-Ping; Guo, Jing-Yi; Shi, Jun

    2010-07-01

    Our previous studies have demonstrated that the muscle thickness change detected by ultrasonography during contraction, namely sonomyography (SMG), can be used for functional assessment of skeletal muscles and has the potential for prosthetic control. In this study, we further investigated the feasibility of using one-dimensional SMG (1-D SMG) signal for controlling a powered prosthesis with one degree of freedom. The performance of SMG control in visual pursuit tracking of opening-closure patterns of the prosthesis was evaluated. Nine normal subjects including seven males and two females participated in the experiment. SMG signals were collected from the extensor carpi radialis muscle to control the opening position of the prosthetic hand. The subjects were instructed to perform the wrist extension movement to match the prosthesis response to the target sinusoid and square tracks under different movement rates as accurately as possible. The normalized root mean square (RMS) tracking error between the target track and the degree of the prosthetic hand's opening position, which was measured by an electronic goniometer, was calculated to evaluate the control performance. It was found that the mean RMS tracking errors of SMG control under different movement rates were 12.8 +/- 3.2% (mean +/- SD) and 14.8 +/- 4.6% for sinusoid and square tracks, respectively. Two-way analysis of variance (ANOVA) revealed significant differences in RMS tracking errors among the three movement rates (p = 2.0 x 10(-6)) and between the two target tracks (p = 0.007). The results suggest that SMG signal, based on further improvement, has potential to be an alternative method for prosthetic control. Copyright 2010 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  8. Simple Instrumental and Visual Tests for Nonlaboratory Environmental Control

    Directory of Open Access Journals (Sweden)

    L. P. Eksperiandova

    2016-01-01

    Full Text Available Proposed are simple and available techniques that can be used for rapid and reliable environmental control specifically of natural water by means of instrumental and visual tests in outdoor conditions. Developed are the chemical colorimetric modes for fast detection of socially dangerous trace impurities in water such as Co(II, Pd(II, and Rh(III as well as NO2--ions and Fe(III serving as model impurities. Application of portable digital devices and scanner allows estimating the color coordinates and increasing the accuracy and sensitivity of the tests. The combination of complex formation with preconcentration of colored complexes replaces the sensitive but time-consuming and capricious kinetic method that is usually used for this purpose at the more convenient and reliable colorimetric method. As the test tools, the following ones are worked out: polyurethane foam tablets with sorbed colored complexes, the two-layer paper sandwich packaged in slide adapter and saturated by reagents, and polyethylene terephthalate blister with dried reagents. Fast analysis of polyurethane foam tablets is realized using a pocket digital RGB-colorimeter or portable photometer. Express analysis of two-layer paper sandwich or polyethylene terephthalate blister is realized by visual and instrumental tests. The metrological characteristics of the developed visual and instrumental express analysis techniques are estimated.

  9. A Multimedia Visual Feedback in the Web-controlled Laboratory

    Directory of Open Access Journals (Sweden)

    J. Turan

    2012-06-01

    Full Text Available The paper presents development work related to create WWW based remote control laboratory for teaching Applied Photonics. In order to minimize the cost at the end-user domain, simple WWW browser with fundamental plug-in (Java applets, HTML Pages and LabWindows applets to support the remote control and video transmission functionality of the remote control is proposed. As for telepresence and monitoring of device actions, a simple type zooming web-camera is connected to the hosting multimedia PC via the USB port. The web-camera assists in visual feedback of the system and presents the feeling of telepresence for the end-user (student. USB web-cameras are normally efficient and the presence of another video server is not necessary in this case, thanks to LabWindows.

  10. Investigating Visual Alerting in Maritime Command and Control

    Science.gov (United States)

    2008-12-01

    environnement, l’automatisation de certaine fonctions et tâches est nécessaire pour atténuer la charge de travail. À cette fin, le PC opérations comporte un bon...Psychophysics, 25, 345-347. 2. Cooper, R. (1998). Visual Dominance and the Control of Action. Proceedings of the 20th Annual Conference of the Cognitive ...Processes II: Attention and Consciousness, pp.78- 80. In Cognition : Sixth Edition. Crawfordsville: John Wiley & Sons. 7. Pigeau, R. (1992). Command

  11. Visual control in children with developmental dyslexia Controle visual em crianças com dislexia do desenvolvimento

    Directory of Open Access Journals (Sweden)

    Stella Maris Costa Castro

    2008-12-01

    Full Text Available PURPOSE: To assess binocular control in children with dyslexia. METHODS: Cross-sectional study with 26 children who were submitted to a set of ophthalmologic and visual tests. RESULTS: In the dyslexic children less eye movement control in voluntary convergence and unstable binocular fixation was observed. CONCLUSION: The results support the hypothesis that developmental dyslexia might present deficits which involve the magnocellular pathway and a part of the posterior cortical attentional network.OBJETIVO: Avaliar o controle binocular em crianças com dislexia. MÉTODOS: Estudo transversal do qual participaram 26 crianças, nas quais foram aplicadas uma série de exames oftalmológicos e visuais. RESULTADOS: Nas crianças com dislexia observou-se controle menor na convergência voluntária e na estabilidade da fixação binocular. CONCLUSÃO: Os resultados apóiam a hipótese de que na dislexia do desenvolvimento podem ocorrer déficits que envolvem a via visual magnocelular e uma parte da rede cortical posterior da atenção.

  12. High variability of the subjective visual vertical test of vertical perception, in some people with neck pain - Should this be a standard measure of cervical proprioception?

    Science.gov (United States)

    Treleaven, Julia; Takasaki, Hiroshi

    2015-02-01

    Subjective visual vertical (SVV) assesses visual dependence for spacial orientation, via vertical perception testing. Using the computerized rod-and-frame test (CRFT), SVV is thought to be an important measure of cervical proprioception and might be greater in those with whiplash associated disorder (WAD), but to date research findings are inconsistent. The aim of this study was to investigate the most sensitive SVV error measurement to detect group differences between no neck pain control, idiopathic neck pain (INP) and WAD subjects. Cross sectional study. Neck Disability Index (NDI), Dizziness Handicap Inventory short form (DHIsf) and the average constant error (CE), absolute error (AE), root mean square error (RMSE), and variable error (VE) of the SVV were obtained from 142 subjects (48 asymptomatic, 36 INP, 42 WAD). The INP group had significantly (p proprioception in neck pain and more research is required before the SVV can be considered an important measure and utilized clinically. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  13. The difference in subjective and objective complexity in the visual short-term memory

    DEFF Research Database (Denmark)

    Dall, Jonas Olsen; Sørensen, Thomas Alrik

    Several studies discuss the influence of complexity on the visual short term memory; some have demonstrated that short-term memory is surprisingly stable regardless of content (e.g. Luck & Vogel, 1997) where others have shown that memory can be influenced by the complexity of stimulus (e.g. Alvarez...... of expertise (e.g. Dall, et al., 2016). We will present a paradigm testing the proposed distinction using specific isolation of attentional components (see Bundesen, 1990; Sørensen, Vangkilde, & Bundesen, 2015). We propose that objective complexity can be manipulated through the number of strokes in Chinese...

  14. A software solution for the control of visual behavioral experimentation.

    Science.gov (United States)

    Meyer, Travis; Constantinidis, Christos

    2005-03-15

    Psychophysical and neurophysiological research requires precise control of experimental devices for the purpose of delivering stimuli and monitoring behavioral and neural responses. This has previously been accomplished by complex, often proprietary, programmable systems, interfacing with a limited range of hardware. We have developed a software solution entirely within the Matlab environment that can achieve high-speed control of experimental and behavioral variables. We make this Wake-Forest Visual Experimentation (WaVE) software freely available under the GNU public license, and demonstrate how to customize it to individual laboratory needs. WaVE takes advantage of existing Matlab libraries and toolboxes to present visual stimuli, collect experimental data, update behavioral variables, and communicate with other computers. Although we have developed it for use in a Windows-based Personal Computer, the portability of the Matlab code makes possible its customization for use in a variety of other systems. We present simulation results showing sub-millisecond sampling rate and updating precision, running on single-processor, desktop PCs. The WaVE software offers a simple, flexible and powerful solution that compares favorably with many of its costly alternatives.

  15. Atypical evening cortisol profile induces visual recognition memory deficit in healthy human subjects

    Directory of Open Access Journals (Sweden)

    Gilpin Heather

    2008-08-01

    Full Text Available Abstract Background Diurnal rhythm-mediated endogenous cortisol levels in humans are characterised by a peak in secretion after awakening that declines throughout the day to an evening trough. However, a significant proportion of the population exhibits an atypical cycle of diurnal cortisol due to shift work, jet-lag, aging, and mental illness. Results The present study has demonstrated a correlation between elevation of cortisol in the evening and deterioration of visual object recognition memory. However, high evening cortisol levels have no effect on spatial memory. Conclusion This study suggests that atypical evening salivary cortisol levels have an important role in the early deterioration of recognition memory. The loss of recognition memory, which is vital for everyday life, is a major symptom of the amnesic syndrome and early stages of Alzheimer's disease. Therefore, this study will promote a potential physiologic marker of early deterioration of recognition memory and a possible diagnostic strategy for Alzheimer's disease.

  16. No differences in visual theory of mind abilities between euthymic bipolar patients and healthy controls.

    Science.gov (United States)

    Haag, Silvia; Haffner, Paula; Quinlivan, Esther; Brüne, Martin; Stamm, Thomas

    2016-12-01

    Research on theory of mind (ToM) abilities in patients with bipolar disorder has yielded conflicting results. Meta-analyses point to a stable moderate impairment in remitted patients, but factors such as subsyndromal symptoms, illness severity, and deficits in basic neurocognitive functions might act as confounders. Also, differences in deficits depending on task area (cognitive or affective) or task modality (visual or verbal) have been observed. This study aimed to test the hypothesis that euthymic bipolar patients would perform more poorly than healthy subjects on visual cognitive and visual affective ToM tasks. Furthermore, we aimed to explore the relationship between ToM performance and basic neurocognitive functions, subsyndromal symptom severity, and illness burden. Twenty-nine clinically stable outpatients with bipolar disorder and 29 healthy comparison subjects completed a measure of visual cognitive ToM (Mental State Attribution Task, MSAT), a measure of visual affective ToM (Reading the Mind in the Eyes Test, RMET), and a battery of tests assessing neurocognitive functioning (attention, verbal memory, executive functions, and intelligence). Patients did not differ significantly from healthy controls for the ToM tasks or any of the neurocognitive measures, suggesting a high level of neurocognitive functioning in the bipolar group. On average, patients were slower than controls to complete the ToM tasks. Within the bipolar group, ToM performance was moderately correlated with attention, verbal memory and reasoning abilities. Performance on the RMET was positively correlated with clinician-rated depressive symptoms with a small effect. Number of years of illness was weakly and negatively correlated with performance on the MSAT. Overall, no moderate or strong correlations were found between ToM performance, subsyndromal depressive or manic symptoms, illness duration, and number of depressive or (hypo)manic episodes. Moderate correlations between To

  17. A biomechanical analysis of trunk and pelvis motion during gait in subjects with knee osteoarthritis compared to control subjects.

    Science.gov (United States)

    Linley, Heather S; Sled, Elizabeth A; Culham, Elsie G; Deluzio, Kevin J

    2010-12-01

    Trunk lean over the stance limb during gait has been linked to a reduction in the knee adduction moment, which is associated with joint loading. We examined differences in knee adduction moments and frontal plane trunk lean during gait between subjects with knee osteoarthritis and a control group of healthy adults. Gait analysis was performed on 80 subjects (40 osteoarthritis). To define lateral trunk lean two definitions were used. The line connecting the midpoint between two reference points on the pelvis and the midpoint between the acromion processes was projected onto the lab frontal plane and the pelvis frontal plane. Pelvic tilt was also measured in the frontal plane as the angle between the pelvic and lab coordinate systems. Angles were calculated across the stance phase of gait. We analyzed the data, (i) by extracting discrete parameters (mean and peak) waveform values, and (ii) using principal component analysis to extract shape and magnitude differences between the waveforms. Osteoarthritis subjects had a higher knee adduction moment than the control group (α=0.05). Although the discrete parameters for trunk lean did not show differences between groups, principal component analysis did detect characteristic waveform differences between the control and osteoarthritis groups. A thorough biomechanical analysis revealed small differences in the pattern of motion of the pelvis and the trunk between subjects with knee osteoarthritis and control subjects; however these differences were only detectable using principal component analysis. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Inhibitory behavioral control: A stochastic dynamic causal modeling study comparing cocaine dependent subjects and controls

    Directory of Open Access Journals (Sweden)

    Liangsuo Ma

    2015-01-01

    Full Text Available Cocaine dependence is associated with increased impulsivity in humans. Both cocaine dependence and impulsive behavior are under the regulatory control of cortico-striatal networks. One behavioral laboratory measure of impulsivity is response inhibition (ability to withhold a prepotent response in which altered patterns of regional brain activation during executive tasks in service of normal performance are frequently found in cocaine dependent (CD subjects studied with functional magnetic resonance imaging (fMRI. However, little is known about aberrations in specific directional neuronal connectivity in CD subjects. The present study employed fMRI-based dynamic causal modeling (DCM to study the effective (directional neuronal connectivity associated with response inhibition in CD subjects, elicited under performance of a Go/NoGo task with two levels of NoGo difficulty (Easy and Hard. The performance on the Go/NoGo task was not significantly different between CD subjects and controls. The DCM analysis revealed that prefrontal–striatal connectivity was modulated (influenced during the NoGo conditions for both groups. The effective connectivity from left (L anterior cingulate cortex (ACC to L caudate was similarly modulated during the Easy NoGo condition for both groups. During the Hard NoGo condition in controls, the effective connectivity from right (R dorsolateral prefrontal cortex (DLPFC to L caudate became more positive, and the effective connectivity from R ventrolateral prefrontal cortex (VLPFC to L caudate became more negative. In CD subjects, the effective connectivity from L ACC to L caudate became more negative during the Hard NoGo conditions. These results indicate that during Hard NoGo trials in CD subjects, the ACC rather than DLPFC or VLPFC influenced caudate during response inhibition.

  19. Visualization of historical data for the ATLAS detector controls - DDV

    Science.gov (United States)

    Maciejewski, J.; Schlenker, S.

    2017-10-01

    The ATLAS experiment is one of four detectors located on the Large Hardon Collider (LHC) based at CERN. Its detector control system (DCS) stores the slow control data acquired within the back-end of distributed WinCC OA applications, which enables the data to be retrieved for future analysis, debugging and detector development in an Oracle relational database. The ATLAS DCS Data Viewer (DDV) is a client-server application providing access to the historical data outside of the experiment network. The server builds optimized SQL queries, retrieves the data from the database and serves it to the clients via HTTP connections. The server also implements protection methods to prevent malicious use of the database. The client is an AJAX-type web application based on the Vaadin (framework build around the Google Web Toolkit (GWT)) which gives users the possibility to access the data with ease. The DCS metadata can be selected using a column-tree navigation or a search engine supporting regular expressions. The data is visualized by a selection of output modules such as a java script value-over time plots or a lazy loading table widget. Additional plugins give the users the possibility to retrieve the data in ROOT format or as an ASCII file. Control system alarms can also be visualized in a dedicated table if necessary. Python mock-up scripts can be generated by the client, allowing the user to query the pythonic DDV server directly, such that the users can embed the scripts into more complex analysis programs. Users are also able to store searches and output configurations as XML on the server to share with others via URL or to embed in HTML.

  20. Efficacy of Visual-Acoustic Biofeedback Intervention for Residual Rhotic Errors: A Single-Subject Randomization Study.

    Science.gov (United States)

    McAllister Byun, Tara

    2017-05-24

    This study documented the efficacy of visual-acoustic biofeedback intervention for residual rhotic errors, relative to a comparison condition involving traditional articulatory treatment. All participants received both treatments in a single-subject experimental design featuring alternating treatments with blocked randomization of sessions to treatment conditions. Seven child and adolescent participants received 20 half-hour sessions of individual treatment over 10 weeks. Within each week, sessions were randomly assigned to feature traditional or biofeedback intervention. Perceptual accuracy of rhotic production was assessed in a blinded, randomized fashion. Each participant's response to the combined treatment package was evaluated by using effect sizes and visual inspection. Differences in the magnitude of response to traditional versus biofeedback intervention were measured with individual randomization tests. Four of 7 participants demonstrated a clinically meaningful response to the combined treatment package. Three of 7 participants showed a statistically significant difference between treatment conditions. In all 3 cases, the magnitude of within-session gains associated with biofeedback exceeded the gains associated with traditional treatment. These results suggest that the inclusion of visual-acoustic biofeedback can enhance the efficacy of intervention for some individuals with residual rhotic errors. Further research is needed to understand which participants represent better or poorer candidates for biofeedback treatment.

  1. Anxiety, Locus of Control, Subjective Well Being and Knowledge of ...

    African Journals Online (AJOL)

    The present study determines a few differences between accident free drivers and drivers with a history of accidents. 30 public transport bus drivers with a record of road accidents were compared with 30 public transport drivers free of accidents on their knowledge of road rules an regulations, subjective well being, state and ...

  2. Circulating Total Glutathione in Normal Tension Glaucoma Patients: Comparison with Normal Control Subjects

    Science.gov (United States)

    Park, Myoung Hee

    2012-01-01

    Purpose Oxidative stress plays a critical role in the pathogenesis of glaucoma. Glutathione is a major antioxidant molecule present in intracellular or extracellular space. Herein, we aimed to examine circulating glutathione level in normal tension glaucoma (NTG), which comprises the largest proportion of glaucoma disease in the Korean population. Methods Nineteen NTG patients (NTG group) and 30 age- and gender-matched normal control subjects (control group) were included. Antecubital venous puncture was performed between 8 and 10 o'clock in the morning to obtain a 4 mL venous blood sample. Total glutathione level was measured by the spectrophotometric method at 412 nm. Correlation of total glutathione level with mean deviation and pattern standard deviation from the Humphrey visual field test was analyzed in the NTG group. Results Total glutathione level in circulating blood was 524.02 ± 231.09 nmol and 586.06 ± 156.08 nmol in the NTG group and the control group, respectively. The difference between these values was not statistically significant (p = 0.121, F = 2.212). Age had no significant effect on circulating total glutathione level in either the NTG group (p = 0.171, r = -0.328) or the control group (p = 0.380, r = -0.166). In the NTG group, circulating total glutathione level had no significant relationship with mean deviation (p = 0.226, F = 1.636) and pattern standard deviation (p = 0.200, F = 1.766) after correcting for age and gender. Conclusions In NTG patients, circulating total glutathione levels were not different compared to those of normal subjects. PMID:22511833

  3. Complex network inference from P300 signals: Decoding brain state under visual stimulus for able-bodied and disabled subjects

    Science.gov (United States)

    Gao, Zhong-Ke; Cai, Qing; Dong, Na; Zhang, Shan-Shan; Bo, Yun; Zhang, Jie

    2016-10-01

    Distinguishing brain cognitive behavior underlying disabled and able-bodied subjects constitutes a challenging problem of significant importance. Complex network has established itself as a powerful tool for exploring functional brain networks, which sheds light on the inner workings of the human brain. Most existing works in constructing brain network focus on phase-synchronization measures between regional neural activities. In contrast, we propose a novel approach for inferring functional networks from P300 event-related potentials by integrating time and frequency domain information extracted from each channel signal, which we show to be efficient in subsequent pattern recognition. In particular, we construct brain network by regarding each channel signal as a node and determining the edges in terms of correlation of the extracted feature vectors. A six-choice P300 paradigm with six different images is used in testing our new approach, involving one able-bodied subject and three disabled subjects suffering from multiple sclerosis, cerebral palsy, traumatic brain and spinal-cord injury, respectively. We then exploit global efficiency, local efficiency and small-world indices from the derived brain networks to assess the network topological structure associated with different target images. The findings suggest that our method allows identifying brain cognitive behaviors related to visual stimulus between able-bodied and disabled subjects.

  4. Entropic Movement Complexity Reflects Subjective Creativity Rankings of Visualized Hand Motion Trajectories

    Science.gov (United States)

    Peng, Zhen; Braun, Daniel A.

    2015-01-01

    In a previous study we have shown that human motion trajectories can be characterized by translating continuous trajectories into symbol sequences with well-defined complexity measures. Here we test the hypothesis that the motion complexity individuals generate in their movements might be correlated to the degree of creativity assigned by a human observer to the visualized motion trajectories. We asked participants to generate 55 novel hand movement patterns in virtual reality, where each pattern had to be repeated 10 times in a row to ensure reproducibility. This allowed us to estimate a probability distribution over trajectories for each pattern. We assessed motion complexity not only by the previously proposed complexity measures on symbolic sequences, but we also propose two novel complexity measures that can be directly applied to the distributions over trajectories based on the frameworks of Gaussian Processes and Probabilistic Movement Primitives. In contrast to previous studies, these new methods allow computing complexities of individual motion patterns from very few sample trajectories. We compared the different complexity measures to how a group of independent jurors rank ordered the recorded motion trajectories according to their personal creativity judgment. We found three entropic complexity measures that correlate significantly with human creativity judgment and discuss differences between the measures. We also test whether these complexity measures correlate with individual creativity in divergent thinking tasks, but do not find any consistent correlation. Our results suggest that entropic complexity measures of hand motion may reveal domain-specific individual differences in kinesthetic creativity. PMID:26733896

  5. Entropic movement complexity reflects subjective creativity rankings of visualized hand motion trajectories

    Directory of Open Access Journals (Sweden)

    Zhen ePeng

    2015-12-01

    Full Text Available In a previous study we have shown that human motion trajectories can be characterized by translating continuous trajectories into symbol sequences with well-defined complexity measures. Here we test the hypothesis that the motion complexity individuals generate in their movements might be correlated to the degree of creativity assigned by a human observer to the visualized motion trajectories. We asked participants to generate fifty-five novel hand movement patterns in virtual reality, where each pattern had to be repeated ten times in a row to ensure reproducibility. This allowed us to estimate a probability distribution over trajectories for each pattern. We assessed motion complexity not only by the previously proposed complexity measures on symbolic sequences, but we also propose two novel complexity measures that can be directly applied to the distributions over trajectories based on the frameworks of Gaussian Processes and Probabilistic Movement Primitives. In contrast to previous studies, these new methods allow computing complexities of individual motion patterns from very few sample trajectories. We compared the different complexity measures to how a group of independent jurors rank ordered the recorded motion trajectories according to their personal creativity judgment. We found three entropic complexity measures that correlate significantly with human creativity judgment and discuss differences between the measures. We also test whether these complexity measures correlate with individual creativity in divergent thinking tasks, but do not find any consistent correlation. Our results suggest that entropic complexity measures of hand motion may reveal domain-specific individual differences in kinesthetic creativity.

  6. Early visual responses predict conscious face perception within and between subjects during binocular rivalry

    Science.gov (United States)

    Sandberg, Kristian; Bahrami, Bahador; Kanai, Ryota; Barnes, Gareth Robert; Overgaard, Morten; Rees, Geraint

    2014-01-01

    Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170-800ms after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using multivariate classification on MEG data recorded when participants reported changes in conscious perception evoked by binocular rivalry between a face and a grating, we showed that only MEG signals in the 120-320ms time range, peaking at the M170 around 180ms and the P2m at around 260ms, reliably predicted conscious experience. Conscious perception could not only be decoded significantly better than chance from the sensors that showed the largest average difference, as previous studies suggest, but also from patterns of activity across groups of occipital sensors that individually were unable to predict perception better than chance. Additionally, source space analyses showed that sources in the early and late visual system predicted conscious perception more accurately than frontal and parietal sites, although conscious perception could also be decoded there. Finally, the patterns of neural activity associated with conscious face perception generalized from one participant to another around the times of maximum prediction accuracy. Our work thus demonstrates that the neural correlates of particular conscious contents (here, faces) are highly consistent in time and space within individuals and that these correlates are shared to some extent between individuals. PMID:23281780

  7. Early visual responses predict conscious face perception within and between subjects during binocular rivalry.

    Science.gov (United States)

    Sandberg, Kristian; Bahrami, Bahador; Kanai, Ryota; Barnes, Gareth Robert; Overgaard, Morten; Rees, Geraint

    2013-06-01

    Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170-800 msec after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using multivariate classification on MEG data recorded when participants reported changes in conscious perception evoked by binocular rivalry between a face and a grating, we showed that only MEG signals in the 120-320 msec time range, peaking at the M170 around 180 msec and the P2m at around 260 msec, reliably predicted conscious experience. Conscious perception could not only be decoded significantly better than chance from the sensors that showed the largest average difference, as previous studies suggest, but also from patterns of activity across groups of occipital sensors that individually were unable to predict perception better than chance. In addition, source space analyses showed that sources in the early and late visual system predicted conscious perception more accurately than frontal and parietal sites, although conscious perception could also be decoded there. Finally, the patterns of neural activity associated with conscious face perception generalized from one participant to another around the times of maximum prediction accuracy. Our work thus demonstrates that the neural correlates of particular conscious contents (here, faces) are highly consistent in time and space within individuals and that these correlates are shared to some extent between individuals.

  8. The New Visual Testimonial: Narrative, Authenticity, and Subjectivity in Emerging Commercial Photographic Practice

    Directory of Open Access Journals (Sweden)

    Heather Morton

    2017-03-01

    Full Text Available By studying the cultural and aesthetic impact of increasingly pervasive digital technologies and mass amateurization, this paper examines the ramifications of the networked information economy on professional photographic practice and considers the concomitant implications for the photographic classroom. Using the framework of convergence culture as per the writings of Yochai Benkler, Henry Jenkins, Mark Deuze, and Axel Bruns, the impact of accessible and instantaneous image creation and dispersal are explored. Given the rise of consumer engagement in brand co-creation on social media platforms, we can observe massive changes to professional practice in areas such as aesthetics, and the erosion of previous sustainable business models. Indeed, as traditional notions of “expertise” shift from technological prowess to narrative and disseminative abilities, the effects on commercial practice and photographic education need to be addressed. This paper argues that there are three emerging priorities for commercial image use: narrative ability, authenticity, and subjectivity and suggests initial steps in their pedagogical application. By acknowledging these transformations, this paper explores the idea that students need to harness technique, social media influence, adaptability, subjectivity, and storytelling power in order to better serve emerging image-based needs in commercial spaces.

  9. Stimulation from Cochlear Implant Electrodes Assists with Recovery from Asymmetric Perceptual Tilt: Evidence from the Subjective Visual Vertical Test

    Directory of Open Access Journals (Sweden)

    Joshua J. Gnanasegaram

    2016-09-01

    Full Text Available Vestibular end organ impairment is highly prevalent in children who have sensorineural hearing loss (SNHL rehabilitated with cochlear implants (CIs. As a result, spatial perception is likely to be impacted in this population. Of particular interest is the perception of visual vertical because it reflects a perceptual tilt in the roll axis and is sensitive to an imbalance in otolith function. The objectives of the present study were thus to identify abnormalities in perception of the vertical plane in children with SNHL and determine whether such abnormalities could be resolved with stimulation from the CI. Participants included 53 children (15.2±4.0 years of age with SNHL and vestibular loss, confirmed with vestibular evoked myogenic potential testing. Testing protocol was validated in a sample of 9 young adults with normal hearing (28.8±7.7 years. Perception of visual vertical was assessed using the static Subjective Visual Vertical (SVV test performed with and without stimulation in the participants with cochleovestibular loss. Trains of electrical pulses were delivered by an electrode in the left and/or right ear. Asymmetric spatial orientation deficits were found in nearly half of the participants with CIs (24/53 [45%]. The abnormal perception in this cohort was exacerbated by visual tilts in the direction of their deficit. Electric pulse trains delivered using the CI shifted this abnormal perception towards centre (i.e., normal [p = 0.007]. Importantly, this benefit was realized regardless of which ear was stimulated. These results suggest a role for CI stimulation beyond the auditory system, in particular, for improving vestibular/balance function.

  10. [Efficacy of modified auriculotherapy for post-operative pain control in patients subjected to laparoscopic cholecystectomy].

    Science.gov (United States)

    Toca-Villegas, Jiovanni; Esmer-Sánchez, David; García-Narváez, Jesús; Sánchez-Aguilar, Martín; Hernández-Sierra, Juan Francisco

    The high frequency of post-operative pain in the patients after laparoscopic cholecystectomy has led to the need to use multiple analgesic therapies. These include auriculotherapy, although not very good results have been obtained with the traditional techniques. To evaluate the effectiveness of modified auriculotherapy for post-operative pain control in laparoscopic cholecystectomy patients. Double-blind controlled clinical trial. Experimental group: Different points ear puncture with xylocaine without needles vs. placebo group. Post-operative visual analogue scale (VAS) at 6, 12, 18, 24, 36, and 48h and rescue doses of analgesics, were measured in both groups. At 6h post-operative, 87% of the auriculotherapy group had a VAS of<4 vs. 48% of placebo group (p = 0.004), and 96 vs. 74% (p = 0.008) at 18hours. At 24, 36 and 48h after surgery there were no differences, and as all of the patients in both groups had a VAS<4, they were discharged to the hospital. Modified auriculotherapy was better to the conventional analgesics for post-operative pain control in patients subjected to laparoscopic cholecystectomy. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  11. Bootstrap Signal-to-Noise Confidence Intervals: An Objective Method for Subject Exclusion and Quality Control in ERP Studies

    Directory of Open Access Journals (Sweden)

    Nathan A Parks

    2016-02-01

    Full Text Available Analysis of event-related potential (ERP data includes several steps to ensure that ERPs meet an appropriate level of signal quality. One such step, subject exclusion, rejects subject data if ERP waveforms fail to meet an appropriate level of signal quality. Subject exclusion is an important quality control step in the ERP analysis pipeline as it ensures that statistical inference is based only upon those subjects exhibiting clear evoked brain responses. This critical quality control step is most often performed simply through visual inspection of subject-level ERPs by investigators. Such an approach is qualitative, subjective, and susceptible to investigator bias, as there are no standards as to what constitutes an ERP of sufficient signal quality. Here, we describe a standardized and objective method for quantifying waveform quality in individual subjects and establishing criteria for subject exclusion. The approach uses bootstrap resampling of ERP waveforms (from a pool of all available trials to compute a signal-to-noise ratio confidence interval (SNR-CI for individual subject waveforms. The lower bound of this SNR-CI (SNRLB yields an effective and objective measure of signal quality as it ensures that ERP waveforms statistically exceed a desired signal-to-noise criterion. SNRLB provides a quantifiable metric of individual subject ERP quality and eliminates the need for subjective evaluation of waveform quality by the investigator. We detail the SNR-CI methodology, establish the efficacy of employing this approach with Monte Carlo simulations, and demonstrate its utility in practice when applied to ERP datasets.

  12. Bootstrap Signal-to-Noise Confidence Intervals: An Objective Method for Subject Exclusion and Quality Control in ERP Studies

    Science.gov (United States)

    Parks, Nathan A.; Gannon, Matthew A.; Long, Stephanie M.; Young, Madeleine E.

    2016-01-01

    Analysis of event-related potential (ERP) data includes several steps to ensure that ERPs meet an appropriate level of signal quality. One such step, subject exclusion, rejects subject data if ERP waveforms fail to meet an appropriate level of signal quality. Subject exclusion is an important quality control step in the ERP analysis pipeline as it ensures that statistical inference is based only upon those subjects exhibiting clear evoked brain responses. This critical quality control step is most often performed simply through visual inspection of subject-level ERPs by investigators. Such an approach is qualitative, subjective, and susceptible to investigator bias, as there are no standards as to what constitutes an ERP of sufficient signal quality. Here, we describe a standardized and objective method for quantifying waveform quality in individual subjects and establishing criteria for subject exclusion. The approach uses bootstrap resampling of ERP waveforms (from a pool of all available trials) to compute a signal-to-noise ratio confidence interval (SNR-CI) for individual subject waveforms. The lower bound of this SNR-CI (SNRLB) yields an effective and objective measure of signal quality as it ensures that ERP waveforms statistically exceed a desired signal-to-noise criterion. SNRLB provides a quantifiable metric of individual subject ERP quality and eliminates the need for subjective evaluation of waveform quality by the investigator. We detail the SNR-CI methodology, establish the efficacy of employing this approach with Monte Carlo simulations, and demonstrate its utility in practice when applied to ERP datasets. PMID:26903849

  13. Aeroelastic Wing Shaping Control Subject to Actuation Constraints.

    Science.gov (United States)

    Swei, Sean Shan-Min; Nguyen, Nhan

    2014-01-01

    This paper considers the control of coupled aeroelastic aircraft model which is configured with Variable Camber Continuous Trailing Edge Flap (VCCTEF) system. The relative deflection between two adjacent flaps is constrained and this actuation constraint is accounted for when designing an effective control law for suppressing the wing vibration. A simple tuned-mass damper mechanism with two attached masses is used as an example to demonstrate the effectiveness of vibration suppression with confined motion of tuned masses. In this paper, a dynamic inversion based pseudo-control hedging (PCH) and bounded control approach is investigated, and for illustration, it is applied to the NASA Generic Transport Model (GTM) configured with VCCTEF system.

  14. Effectiveness of a perceptual - proprioceptive training with virtual visual feedback in healthy subjects: a pilot study

    Directory of Open Access Journals (Sweden)

    Stefano Vando

    2013-06-01

    Full Text Available Background: the aim of this pilot study was to evaluate whether proprioceptive-motor training using the Wii Balance Board (WBB might improve postural sway in healthy subjects.Methods: twenty-five healthy subjects were trained for six weeks (two sessions per week with 5 “video games”: Wii Fit Plus (WFP program. Before and after training: Basic Balance, Single-leg Balance, Agility, Stability and Motion (lower limb: right-left and both leg were measured using the Wii Balance Board.Results: the Wilcoxon Test showed improvements at the end of the training program compared to the baseline conditions. Basic Balance increased during the WFP (33.33% and was associated with a 19.92% decrease in center of pressure (COP lenght. The Single-leg Balance results incremented after the WFP (left 29.09% vs. right 47.92% and accompanied by a decrement in COP (left 28.71% vs. right 30.45%. The values for the Agility test increased both in WFP and COP (28.57% and 58.57%, respectively. The Stability test scores increased in the WFP (66.67% along with a consequent decrease in COP (10.53%. Finally, the Motion test values increased in the WFP (73.17%, whilst COP for this test decreased (12.02%. These results indicate that 6 weeks of virtual training produced a good adaptability. Younger participants (<20 years demonstrated to be more responsive to dynamic stimulation with respect to those >20 years.Conclusions: significant improvements in all participants were observed, indicating that virtual training can influence posture and balance in healthy people. Because of its characteristics of low cost and easy availability, a portable system for balance training for everyone offers the possibility to more readily measure motor skill and to gauge improvement.

  15. [Subjective visual perception after laser treatment of myopia on two types of lasers].

    Science.gov (United States)

    Kyprianou, G; Machácková, M; Feuermannová, A; Rozsíval, P; Langrová, H

    2010-11-01

    Comparison of subjective evaluation of patients with low and moderate myopia undergoing photorefractive keratectomy (PRK) and Laser in Situ Keratomileusis (LASIK) on two types of excimer lasers: Schwind Esiris and Schwind Amaris. Patients were divided into two groups according to the type of laser that was used. Group A comprised of 23 patients (14 females, 9 males) of average age 33.1 years (range 21-51 years), with an average spherical equivalent before operation of -3.5D. Using the excimer laser Esiris (Schwind, Germany), 10 patients had undergone PRK and 13 LASIK. Group B comprised of 32 patients (21 females, 11 males), of average age 31.9 years (range 22-48 years). Median spherical equivalent before operation was -3.05D. With the excimer laser Amaris (Schwind, Germany) 17 patients had undergone PRK and 15 LASIK. For the subjective evaluation we set up a questioner consisting of 21 questions that were aimed on the quality of vision under various illumination types and intensities, vision under various distances, activities and also questions concerning superficial sensitivity of the anterior segment of the eye. We detected a 100% satisfaction one year after refractive laser treatment with both laser types. Statistical improvement was evident by one month after treatment in both patient groups and upto 12 months it progressively increased. Statistically significant differences were noted one month after treatment, where patients in group B were more satisfied in questions concerning quality of vision, distance vision, while watching TV and driving during daytime and during the night. During further follow-up, results were comparable between both groups. Temporary patient satisfaction treated with laser Amaris is apparently due to the result of a more sparing treatment and thus fewer changes in the corneal stroma.

  16. Power Assist Control of Robotic Wheelchair Based on Visual Feedback

    Science.gov (United States)

    Oda, Naoki; Shimizu, Hiroyuki

    This paper describes a vision based self-velocity estimation and its feedback system under force/torque sensor-less power assisting control of wheelchair robot. In this method, three dimensional information obtained by stereo images, and the optical flow vectors are also used for self-velocity estimation in real-time. The human force is estimated by sensor-less reaction force observer, and the assisting force is calculated by using its estimated force and virtual impedance model. In the paper, the force based assist function is integrated into visual feedback motion controller. This approach using vision and force based assist control makes it possible to facilitate the direct intelligent interactions between human force and environments such as human following assist, obstacle avoidance one and so on. Such assist functions are changeable by the selection of the weighting matrix in the velocity estimation, which is based on weighted least square solutions from optical flow vectors. The validity of the proposed approach is verified by several experimental results.

  17. Prioritized Control Allocation for Quadrotors Subject to Saturation

    NARCIS (Netherlands)

    Smeur, E.J.J.; de Wagter, C.; J.-M. Moschetta G. Hattenberger, H. de Plinval

    2017-01-01

    This paper deals with the problem of actuator saturation for INDI (Incremental Nonlinear Dynamic Inversion) controlled flying vehicles. The primary problem that arises from actuator saturation for quadrotors, is that of arbitrary control objective realization. We have integrated the weighted least

  18. Visual analogue scale foot and ankle: validity and reliability of Thai version of the new outcome score in subjective form.

    Science.gov (United States)

    Angthong, Chayanin; Chernchujit, Bancha; Suntharapa, Thongchai; Harnroongroj, Thossart

    2011-08-01

    Nowadays, measuring score in the form of subjective questionnaires is the important tool for clinical evaluation of the foot and ankle-related problems. VisualAnalogue Scale-Foot and Ankle (VAS-FA) is the newly developed subjective questionnaire, which has sufficiency of validity and reliability from a previous study Translate the original English version of VAS-FA into the Thai version and evaluate the validity and reliability of Thai VAS-FA in patients with foot and ankle-related problems. According to the forward-backward translation protocol, original VAS-FA was translated into the Thai version. Thai VAS-FA and validated Thai Short Form-36 (SF-36) questionnaires were distributed to 42 Thai patients to complete. For validation, Thai VAS-FA scores were correlated with SF-36 scores. For reliability, the test-retest reliability and internal consistency were analyzed. Thai VAS-FA score demonstrated the sufficient correlations with physical functioning (PF), role physical (RP), bodily pain (BP) domains, and total score of SF-36 (statistically significant with p 0.5 values). The result of reliability revealed highly intra-class correlation coefficient as 0.995 from test-retest study. The internal consistency was excellent with Cronbach alpha: 0.995. The original VAS-FA score is a well-validated, subjective, visual-analogue-scale based outcome score. The Thai version of VAS-FA form maintained the validity and reliability of the original version. This newly translated-validated score can be distributed for the evaluation of the functions, symptoms, and limitation of activities in Thai patients with foot and ankle problems.

  19. On spacecraft maneuvers control subject to propellant engine modes.

    Science.gov (United States)

    Mazinan, A H

    2015-09-01

    The paper attempts to address a new control approach to spacecraft maneuvers based upon the modes of propellant engine. A realization of control strategy is now presented in engine on mode (high thrusts as well as further low thrusts), which is related to small angle maneuvers and engine off mode (specified low thrusts), which is also related to large angle maneuvers. There is currently a coarse-fine tuning in engine on mode. It is shown that the process of handling the angular velocities are finalized via rate feedback system in engine modes, where the angular rotations are controlled through quaternion based control (QBCL)strategy in engine off mode and these ones are also controlled through an optimum PID (OPIDH) strategy in engine on mode. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  20. ADAPTIVE OUTPUT CONTROL: SUBJECT MATTER, APPLICATION TASKS AND SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Alexey A. Bobtsov

    2013-01-01

    Full Text Available The problem of adaptive output control for parametric and functionally uncertain plants is considered. Application examples illustrating the practical use of the discussed theory are given along with the mathematical formulation of the problem. A brief review of adaptive output control methods, by both linear and non-linear systems, is presented and an extensive bibliography, in which the reader will find a detailed description of the specific algorithms and their properties, is represented. A new approach to the output control problem - a method of consecutive compensator - is considered in detail.

  1. Subjective and objective knowledge and decisional role preferences in cerebrovascular patients compared to controls

    Directory of Open Access Journals (Sweden)

    Riechel C

    2016-08-01

    Full Text Available Christina Riechel,1,* Anna Christina Alegiani,1,* Sascha Köpke,2 Jürgen Kasper,3,4 Michael Rosenkranz,1,5 Götz Thomalla,1 Christoph Heesen1,4 1Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; 2Nursing Research Unit, Institute of Social Medicine and Epidemiology, University of Lübeck, Lübeck, Germany; 3Department of Health and Caring Sciences, Faculty of Health Sciences, University of Tromsø, Tromsø, Norway; 4Institute of Neuroimmunology and Multiple Sclerosis, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; 5Department of Neurology, Albertinen-Krankenhaus, Hamburg, Germany *These authors contributed equally to this work Background: Risk knowledge and active role preferences are important for patient involvement in treatment decision-making and adherence. Although knowledge about stroke warning signs and risk factors has received considerable attention, objective knowledge on secondary prevention and further self-esteem subjective knowledge have rarely been studied. The aim of our study was to investigate knowledge and treatment decisional role preferences in cerebrovascular patients compared to controls. Methods: We performed a survey on subjective and objective stroke risk knowledge and autonomy preferences in cerebrovascular patients from our stroke outpatient clinic (n=262 and from pedestrians on the street taken as controls during a “World Stroke Day” (n=274. The questionnaire includes measures for knowledge and decisional role preferences from previously published questionnaires and newly developed measures, for example, subjective knowledge, revealed on a visual analog scale. Results: The overall stroke knowledge was low to moderate, with no differences between patients and controls. Knowledge about secondary prevention was particularly low. Only 10%–15% of participants correctly estimated the stroke absolute risk reduction potential of aspirin. The medical data

  2. Ethics commentary: subjects of knowledge and control in field primatology.

    Science.gov (United States)

    Malone, N M; Fuentes, A; White, F J

    2010-09-01

    Our primate kin are routinely displaced from their habitats, hunted for meat, captured for trade, housed in zoos, made to perform for our entertainment, and used as subjects in biomedical testing. They are also the subjects of research inquiries by field primatologists. In this article, we place primate field studies on a continuum of human and alloprimate relationships as a heuristic device to explore the unifying ethical implications of such inter-relationships, as well as address specific ethical challenges arising from common research protocols "in the field" (e.g. risks associated with habituation, disease transmission, invasive collection of biological samples, etc.). Additionally, we question the widespread deployment of conservation- and/or local economic development-based justifications for field-based primatological pursuits. Informed by decades of combined fieldwork experience in Indonesia and the Democratic Republic of Congo, we demonstrate the process by which the adherence to a particular ethical calculus can lead to unregulated and ethically problematic research agendas. In conclusion, we offer several suggestions to consider in the establishment of a formalized code of ethics for field primatology. (c) 2010 Wiley-Liss, Inc.

  3. Visual perception affected by motivation and alertness controlled by a noninvasive brain-computer interface.

    Directory of Open Access Journals (Sweden)

    Vladimir A Maksimenko

    Full Text Available The influence of motivation and alertness on brain activity associated with visual perception was studied experimentally using the Necker cube, which ambiguity was controlled by the contrast of its ribs. The wavelet analysis of recorded multichannel electroencephalograms (EEG allowed us to distinguish two different scenarios while the brain processed the ambiguous stimulus. The first scenario is characterized by a particular destruction of alpha rhythm (8-12 Hz with a simultaneous increase in beta-wave activity (20-30 Hz, whereas in the second scenario, the beta rhythm is not well pronounced while the alpha-wave energy remains unchanged. The experiments were carried out with a group of financially motivated subjects and another group of unpaid volunteers. It was found that the first scenario occurred mainly in the motivated group. This can be explained by the increased alertness of the motivated subjects. The prevalence of the first scenario was also observed in a group of subjects to whom images with higher ambiguity were presented. We believe that the revealed scenarios can occur not only during the perception of bistable images, but also in other perceptual tasks requiring decision making. The obtained results may have important applications for monitoring and controlling human alertness in situations which need substantial attention. On the base of the obtained results we built a brain-computer interface to estimate and control the degree of alertness in real time.

  4. Velarium control and visual steering in box jellyfish.

    Science.gov (United States)

    Petie, Ronald; Garm, Anders; Nilsson, Dan-Eric

    2013-04-01

    Directional swimming in the box jellyfish Tripedalia cystophora (cubozoa, cnidaria) is controlled by the shape of the velarium, which is a thin muscular sheet that forms the opening of the bell. It was unclear how different patterns of visual stimulation control directional swimming and that is the focus of this study. Jellyfish were tethered inside a small experimental tank, where the four vertical walls formed light panels. All four panels were lit at the start of an experiment. The shape of the opening in the velarium was recorded in response to switching off different combinations of panels. We found that under the experimental conditions the opening in the velarium assumed three distinct shapes during a swim contraction. The opening was (1) centred or it was off-centred and pocketed out either towards (2) a rhopalium or (3) a pedalium. The shape of the opening in the velarium followed the direction of the stimulus as long as the stimulus contained directional information. When the stimulus contained no directional information, the percentage of centred pulses increased and the shape of the off-centred pulses had a random orientation. Removing one rhopalium did not change the directional response of the animals, however, the number of centred pulses increased. When three rhopalia were removed, the percentage of centred pulses increased even further and the animals lost their ability to respond to directional information.

  5. Microfluidic sorting of intrinsically magnetic cells under visual control.

    Science.gov (United States)

    Myklatun, Ahne; Cappetta, Michele; Winklhofer, Michael; Ntziachristos, Vasilis; Westmeyer, Gil G

    2017-07-31

    Magnetic cell sorting provides a valuable complementary mechanism to fluorescent techniques, especially if its parameters can be fine-tuned. In addition, there has recently been growing interest in studying naturally occurring magnetic cells and genetic engineering of cells to render them magnetic in order to control molecular processes via magnetic fields. For such approaches, contamination-free magnetic separation is an essential capability. We here present a robust and tunable microfluidic sorting system in which magnetic gradients of up to 1700 T/m can be applied to cells flowing through a sorting channel by reversible magnetization of ferrofluids. Visual control of the sorting process allowed us to optimize sorting efficiencies for a large range of sizes and magnetic moments of cells. Using automated quantification based on imaging of fluorescent markers, we showed that macrophages containing phagocytosed magnetic nanoparticles, with cellular magnetic dipole moments on the order of 10 fAm2, could be sorted with an efficiency of 90 ± 1%. Furthermore, we successfully sorted intrinsically magnetic magnetotactic bacteria with magnetic moments of 0.1 fAm2. In distinction to column-based magnetic sorting devices, microfluidic systems can prevent sample contact with superparamagnetic material. This ensures contamination-free separation of naturally occurring or bioengineered magnetic cells and is essential for downstream characterization of their properties.

  6. Coordinated Control of Wave Energy Converters Subject to Motion Constraints

    Directory of Open Access Journals (Sweden)

    Liguo Wang

    2016-06-01

    Full Text Available In this paper, a generic coordinated control method for wave energy converters is proposed, and the constraints on motion amplitudes and the hydrodynamic interaction between converters are considered. The objective of the control problem is to maximize the energy converted from ocean waves, and this is achieved by coordinating the power take-off (PTO damping of each wave energy converter in the frequency domain in each sea state. In a case study, a wave energy farm consisting of four converters based on the concept developed by Uppsala University is studied. In the solution, motion constraints, including constraints on the amplitudes of displacement and velocity, are included. Twelve months of sea states, based on measured wave data at the Lysekil test site on the Swedish west coast, are used in the simulation to evaluate the performance of the wave energy farm using the new method. Results from the new coordinated control method and traditional control method are compared, indicating that the coordinated control of wave energy converters is an effective way to improve the energy production of wave energy farm in harmonic waves.

  7. Activation of lateral geniculate nucleus and primary visual cortex as detected by functional magnetic resonance imaging in normal subjects and in patients with visual disturbance

    Energy Technology Data Exchange (ETDEWEB)

    Miki, Atsushi [Niigata Univ. (Japan). Graduate School of Medical and Dental Sciences

    2002-12-01

    Functional magnetic resonance imaging (fMRI) during visual stimulation can detect regional cerebral blood flow changes that reflect neural activity in the lateral geniculate nucleus and primary visual cortex, which are major relay points in the human afferent visual system. FMRI has been used in the clinical evaluation of visual disorders such as homonymous hemianopia and unilateral eye diseases (optic neuritis, amblyopia, and so on). Future development in the data acquisition and data analysis may facilitate the use of fMRI for the management of patients with visual deficits and understanding of the visual disorders. (author)

  8. Single subject controlled experiments in aphasia: The science and the state of the science

    OpenAIRE

    Thompson, Cynthia K.

    2006-01-01

    This paper discusses the use of single subject controlled experimental designs for investigating the effect of treatment for aphasia. A brief historical perspective is presented, followed by discussions of the advantages and disadvantages of single subject and group approaches, the basic requirements of single subject experimental research, and crucial considerations in design selection. In the final sections, results of reviews of published single subject controlled experiments are discussed...

  9. Digital media promoting new approaches to subject specific didactics in visual arts education in primary school, high school, teacher education and university education

    DEFF Research Database (Denmark)

    Skov, Kirsten

    Digital media promoting new approaches to subject specific didactics in visual arts education in primary school, high school, teacher education and university education The symposium addresses current developments in visual arts education based on empirical projects from different levels of the e......Digital media promoting new approaches to subject specific didactics in visual arts education in primary school, high school, teacher education and university education The symposium addresses current developments in visual arts education based on empirical projects from different levels......, social aesthetics, community art and co-creation all represent an approach to art production and appreciation where content, media and visual expressions unfold in societal, digital, collaborative, and transgressive constellations involving the art maker and audiences in social and relational projects...

  10. Subjective well-being in times of social change: congruence of control strategies and perceived control.

    Science.gov (United States)

    Grümer, Sebastian; Silbereisen, Rainer K; Heckhausen, Jutta

    2013-01-01

    This paper investigates the association between perceptions of broader changes in the social-ecological context and individuals' subjective well-being (SWB). Macro-level societal changes such as globalization or demographic change give rise to new demands for individual functioning at work and/or in the family. Such new demands associated with social change are stressful and likely to be related to lower levels of SWB. Being active agents, individuals attempt to deal with social change and its increasing demands to protect their SWB. The present study investigates which kinds of control strategies are most effective in protecting one's SWB. Specifically, we predicted that control strategies of goal engagement will be most effective under conditions of perceived high control, and control strategies of goal disengagement will be most effective under conditions of perceived low control. In a large sample of 2537 German adults, work- and family-related demands associated with social change were found to be negatively linked to SWB. Moreover and in line with the motivational theory of lifespan development, control strategies of goal engagement and disengagement were beneficial for SWB to the extent that they matched the perceived control of the demands associated with social change.

  11. Fourier power, subjective distance and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Directory of Open Access Journals (Sweden)

    Mark Daniel Lescroart

    2015-11-01

    Full Text Available Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA, Retrosplenial Complex (RSC, and the Occipital Place Area (OPA. It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1 2D features related to Fourier power; (2 3D spatial features such as the distance to objects in a scene; or (3 abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM to BOLD fMRI responses elicited by a set of 1,386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue.

  12. Fourier power, subjective distance, and object categories all provide plausible models of BOLD responses in scene-selective visual areas

    Science.gov (United States)

    Lescroart, Mark D.; Stansbury, Dustin E.; Gallant, Jack L.

    2015-01-01

    Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA), Retrosplenial Complex (RSC), and the Occipital Place Area (OPA). It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1) 2D features related to Fourier power; (2) 3D spatial features such as the distance to objects in a scene; or (3) abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM) to BOLD fMRI responses elicited by a set of 1386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue. PMID:26594164

  13. Two visual working memory representations simultaneously control attention

    OpenAIRE

    Chen, Yanan; Du, Feng

    2017-01-01

    It has been proposed that only one visual working memory (VWM) representation can be activated to influence perception directly, whereas other VWM representations are accessory items which have little influence on visual selection. The sole active VWM representation might reflect a fundamental bottleneck in the information processing of human beings. However, the present study showed that each of two VWM representations can capture attention and interfere with concurrent visual search. In add...

  14. Formation of visual memories controlled by gamma power phase-locked to alpha oscillations

    Science.gov (United States)

    Park, Hyojin; Lee, Dong Soo; Kang, Eunjoo; Kang, Hyejin; Hahm, Jarang; Kim, June Sic; Chung, Chun Kee; Jiang, Haiteng; Gross, Joachim; Jensen, Ole

    2016-06-01

    Neuronal oscillations provide a window for understanding the brain dynamics that organize the flow of information from sensory to memory areas. While it has been suggested that gamma power reflects feedforward processing and alpha oscillations feedback control, it remains unknown how these oscillations dynamically interact. Magnetoencephalography (MEG) data was acquired from healthy subjects who were cued to either remember or not remember presented pictures. Our analysis revealed that in anticipation of a picture to be remembered, alpha power decreased while the cross-frequency coupling between gamma power and alpha phase increased. A measure of directionality between alpha phase and gamma power predicted individual ability to encode memory: stronger control of alpha phase over gamma power was associated with better memory. These findings demonstrate that encoding of visual information is reflected by a state determined by the interaction between alpha and gamma activity.

  15. Inertial sensor based gait analysis discriminates subjects with and without visual impairment caused by simulated macular degeneration.

    Science.gov (United States)

    Kanzler, Christoph M; Barth, Jens; Klucken, Jochen; Eskofier, Bjoern M

    2016-08-01

    Macular degeneration is the third leading cause of blindness worldwide and the leading cause of blindness in the developing world. The analysis of gait parameters can be used to assess the influence of macular degeneration on gait. This study examines the effect of macular degeneration on gait using inertial sensor based 3D spatio-temporal gait parameters. We acquired gait data from 21 young and healthy subjects during a 40 m obstacle walk. All subjects had to perform the gait trial with and without macular degeneration simulation glasses. The order of starting with or without glasses alternated between each subject in order to test for training effects. Multiple 3D spatio-temporal gait parameters were calculated for the normal vision as well as the impaired vision groups. The parameters trial time, stride time, stride time coefficient of variation (CV), stance time, stance time CV, stride length, cadence, gait velocity and angle at toe off showed statistically significant differences between the two groups. Training effects were visible for the trials which started without vision impairment. Inter-group differences in the gait pattern occurred due to an increased sense of insecurity related with the loss of visual acuity from the simulation glasses. In summary, we showed that 3D spatio-temporal gait parameters derived from inertial sensor data are viable to detect differences in the gait pattern of subjects with and without a macular degeneration simulation. We believe that this study provides the basis for an in-depth analysis regarding the impact of macular degeneration on gait.

  16. Oxytocin can impair memory for social and non-social visual objects: a within-subject investigation of oxytocin's effects on human memory.

    Science.gov (United States)

    Herzmann, Grit; Young, Brent; Bird, Christopher W; Curran, Tim

    2012-04-27

    Oxytocin is important to social behavior and emotion regulation in humans. Oxytocin's role derives in part from its effect on memory performance. More specifically, previous research suggests that oxytocin facilitates recognition of social (e.g., faces), but not of non-social stimuli (e.g., words, visual objects). We conducted the first within-subject study to this hypothesis in a double-blind, placebo-controlled design. We administered oxytocin (24IU) and placebo (saline) in two separate sessions and in randomized order to healthy men. To obtain a baseline measure for session-dependent memory effects, which are caused by proactive interference, an additional group of male subjects in each session received placebo unbeknownst to them and the experimenter. After administration, participants studied faces and houses. Exactly one day after each study session, participants were asked to make memory judgments of new and old items. In the first study-test session, participants administered with oxytocin showed reduced recollection of previously studied faces and houses. Oxytocin also interacted with proactive-interference effects. By impeding memory in the first session, it reduced proactive interference in the second. But oxytocin contributed additionally to the memory-reducing effect of proactive interference when administered in the second session. These results demonstrate that oxytocin can have a memory-impairing effect on both social and non-social visual objects. The present study also emphasizes the necessity of including a non-treated, baseline group in within-subject designs when investigating oxytocin's effects on human memory. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Case studies on design, simulation and visualization of control and measurement applications using REX control system

    Science.gov (United States)

    Ozana, Stepan; Pies, Martin; Docekal, Tomas

    2016-06-01

    REX Control System is a professional advanced tool for design and implementation of complex control systems that belongs to softPLC category. It covers the entire process starting from simulation of functionality of the application before deployment, through implementation on real-time target, towards analysis, diagnostics and visualization. Basically it consists of two parts: the development tools and the runtime system. It is also compatible with Simulink environment, and the way of implementation of control algorithm is very similar. The control scheme is finally compiled (using RexDraw utility) and uploaded into a chosen real-time target (using RexView utility). There is a wide variety of hardware platforms and real-time operating systems supported by REX Control System such as for example Windows Embedded, Linux, Linux/Xenomai deployed on SBC, IPC, PAC, Raspberry Pi and others with many I/O interfaces. It is modern system designed both for measurement and control applications, offering a lot of additional functions concerning data archiving, visualization based on HTML5, and communication standards. The paper will sum up possibilities of its use in educational process, focused on control of case studies of physical models with classical and advanced control algorithms.

  18. Case studies on design, simulation and visualization of control and measurement applications using REX control system

    Energy Technology Data Exchange (ETDEWEB)

    Ozana, Stepan, E-mail: stepan.ozana@vsb.cz; Pies, Martin, E-mail: martin.pies@vsb.cz; Docekal, Tomas, E-mail: docekalt@email.cz [VSB-Technical University of Ostrava, Faculty of Electrical Engineering and Computer Science, Department of Cybernetics and Biomedical Engineering, 17. listopadu 15/2172, Ostrava-Poruba, 700 30 (Czech Republic)

    2016-06-08

    REX Control System is a professional advanced tool for design and implementation of complex control systems that belongs to softPLC category. It covers the entire process starting from simulation of functionality of the application before deployment, through implementation on real-time target, towards analysis, diagnostics and visualization. Basically it consists of two parts: the development tools and the runtime system. It is also compatible with Simulink environment, and the way of implementation of control algorithm is very similar. The control scheme is finally compiled (using RexDraw utility) and uploaded into a chosen real-time target (using RexView utility). There is a wide variety of hardware platforms and real-time operating systems supported by REX Control System such as for example Windows Embedded, Linux, Linux/Xenomai deployed on SBC, IPC, PAC, Raspberry Pi and others with many I/O interfaces. It is modern system designed both for measurement and control applications, offering a lot of additional functions concerning data archiving, visualization based on HTML5, and communication standards. The paper will sum up possibilities of its use in educational process, focused on control of case studies of physical models with classical and advanced control algorithms.

  19. The Impact of Personal Attitude, Subjective Norm, and Perceived Behavioural Control on Entrepreneurial Intentions of Women

    National Research Council Canada - National Science Library

    DINC, M. Sait; BUDIC, Semira

    2016-01-01

    .... The purpose of the study is to examine the relationship between demographic variables, personal attitude, subjective norm, perceived behavioural control, and entrepreneurial intentions of women...

  20. Visualization and Quality Control Web Tools for CERES Products

    Science.gov (United States)

    Mitrescu, C.; Doelling, D. R.; Rutan, D. A.

    2016-12-01

    The CERES project continues to provide the scientific community a wide variety of satellite-derived data products such as observed TOA broadband shortwave and longwave observed fluxes, computed TOA and Surface fluxes, as well as cloud, aerosol, and other atmospheric parameters. They encompass a wide range of temporal and spatial resolutions, suited to specific applications. Now in its 16-year, CERES products are mostly used by climate modeling communities that focus on global mean energetics, meridianal heat transport, and climate trend studies. In order to serve all our users, we developed a web-based Ordering and Visualization Tool (OVT). Using Opens Source Software such as Eclipse, java, javascript, OpenLayer, Flot, Google Maps, python, and others, the OVT Team developed a series of specialized functions to be used in the process of CERES Data Quality Control (QC). We mention 1- and 2-D histogram, anomaly, deseasonalization, temporal and spatial averaging, side-by-side parameter comparison, and others that made the process of QC far easier and faster, but more importantly far more portable. We are now in the process of integrating ground site observed surface fluxes to further facilitate the CERES project to QC the CERES computed surface fluxes. These features will give users the opportunity to perform their own comparisons of the CERES computed surface fluxes and observed ground site fluxes. An overview of the CERES OVT basic functions using Open Source Software, as well as future steps in expanding its capabilities will be presented at the meeting.

  1. Visual reliance for balance control in older adults persists when visual information is disrupted by artificial feedback delays.

    Directory of Open Access Journals (Sweden)

    Ting Ting Yeh

    Full Text Available Sensory information from our eyes, skin and muscles helps guide and correct balance. Less appreciated, however, is that delays in the transmission of sensory information between our eyes, limbs and central nervous system can exceed several 10s of milliseconds. Investigating how these time-delayed sensory signals influence balance control is central to understanding the postural system. Here, we investigate how delayed visual feedback and cognitive performance influence postural control in healthy young and older adults. The task required that participants position their center of pressure (COP in a fixed target as accurately as possible without visual feedback about their COP location (eyes-open balance, or with artificial time delays imposed on visual COP feedback. On selected trials, the participants also performed a silent arithmetic task (cognitive dual task. We separated COP time series into distinct frequency components using low and high-pass filtering routines. Visual feedback delays affected low frequency postural corrections in young and older adults, with larger increases in postural sway noted for the group of older adults. In comparison, cognitive performance reduced the variability of rapid center of pressure displacements in young adults, but did not alter postural sway in the group of older adults. Our results demonstrate that older adults prioritize vision to control posture. This visual reliance persists even when feedback about the task is delayed by several hundreds of milliseconds.

  2. Visual Reliance for Balance Control in Older Adults Persists When Visual Information Is Disrupted by Artificial Feedback Delays

    Science.gov (United States)

    Balasubramaniam, Ramesh

    2014-01-01

    Sensory information from our eyes, skin and muscles helps guide and correct balance. Less appreciated, however, is that delays in the transmission of sensory information between our eyes, limbs and central nervous system can exceed several 10s of milliseconds. Investigating how these time-delayed sensory signals influence balance control is central to understanding the postural system. Here, we investigate how delayed visual feedback and cognitive performance influence postural control in healthy young and older adults. The task required that participants position their center of pressure (COP) in a fixed target as accurately as possible without visual feedback about their COP location (eyes-open balance), or with artificial time delays imposed on visual COP feedback. On selected trials, the participants also performed a silent arithmetic task (cognitive dual task). We separated COP time series into distinct frequency components using low and high-pass filtering routines. Visual feedback delays affected low frequency postural corrections in young and older adults, with larger increases in postural sway noted for the group of older adults. In comparison, cognitive performance reduced the variability of rapid center of pressure displacements in young adults, but did not alter postural sway in the group of older adults. Our results demonstrate that older adults prioritize vision to control posture. This visual reliance persists even when feedback about the task is delayed by several hundreds of milliseconds. PMID:24614576

  3. LTP-like plasticity in the visual system and in the motor system appear related in young and healthy subjects

    Directory of Open Access Journals (Sweden)

    Stefan eKlöppel

    2015-09-01

    Full Text Available LTP-like plasticity measured by visual evoked potentials (VEP can be induced in the intact human brain by presenting checkerboard reversals. Also associated with LTP-like plasticity, around two third of participants respond to transcranial magnetic stimulation with a paired-associate stimulation (PAS protocol with a potentiation of their motor evoked potentials. LTP-like processes are also required for verbal and motor learning tasks. We compared effect sizes, responder rates and intercorrelations as well as the potential influence of attention between these four assessments in a group of 37 young and healthy volunteers. We observed a potentiation effect of the N75 and P100 VEP component which positively correlated with plasticity induced by PAS. Subjects with a better subjective alertness were more likely to show PAS and VEP potentiation. No correlation was found between the other assessments. Effect sizes and responder rates of VEP potentiation were higher compared to PAS. Our results indicate a high variability of LTP-like effects and no evidence for a system-specific nature. As a consequence, studies wishing to assess individual levels of LTP-like plasticity should employ a combination of multiple assessments.

  4. The initial stage of visual selection is controlled by top-down task set: new ERP evidence.

    Science.gov (United States)

    Ansorge, Ulrich; Kiss, Monika; Worschech, Franziska; Eimer, Martin

    2011-01-01

    Salient visual singleton stimuli produce spatial cueing effects indicative of attentional capture only when they match current task sets, suggesting that capture is subject to top-down control. However, such task-set contingent capture effects could be associated with the top-down controlled disengagement of attention from non-matching stimuli that follows their initial bottom-up salience-driven selection. Using the N2pc component as an event-related potential marker of attentional capture, we demonstrate that top-down task set already controls the initial rapid selection of salient visual singleton stimuli prior to any subsequent attentional disengagement. These findings provide new evidence for the primacy of top-down control over bottom-up salience in attentional capture.

  5. Single Subject Controlled Experiments in Aphasia: The Science and the State of the Science

    Science.gov (United States)

    Thompson, Cynthia K.

    2006-01-01

    This paper discusses the use of single subject controlled experimental designs for investigating the effects of treatment for aphasia. A brief historical perspective is presented, followed by discussions of the advantages and disadvantages of single subject and group approaches, the basic requirements of single subject experimental research, and…

  6. Controlling the spotlight of attention: visual span size and flexibility in schizophrenia.

    Science.gov (United States)

    Elahipanah, Ava; Christensen, Bruce K; Reingold, Eyal M

    2011-10-01

    The current study investigated the size and flexible control of visual span among patients with schizophrenia during visual search performance. Visual span is the region of the visual field from which one extracts information during a single eye fixation, and a larger visual span size is linked to more efficient search performance. Therefore, a reduced visual span may explain patients' impaired performance on search tasks. The gaze-contingent moving window paradigm was used to estimate the visual span size of patients and healthy participants while they performed two different search tasks. In addition, changes in visual span size were measured as a function of two manipulations of task difficulty: target-distractor similarity and stimulus familiarity. Patients with schizophrenia searched more slowly across both tasks and conditions. Patients also demonstrated smaller visual span sizes on the easier search condition in each task. Moreover, healthy controls' visual span size increased as target discriminability or distractor familiarity increased. This modulation of visual span size, however, was reduced or not observed among patients. The implications of the present findings, with regard to previously reported visual search deficits, and other functional and structural abnormalities associated with schizophrenia, are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. A lower limb exoskeleton control system based on steady state visual evoked potentials

    Science.gov (United States)

    Kwak, No-Sang; Müller, Klaus-Robert; Lee, Seong-Whan

    2015-10-01

    Objective. We have developed an asynchronous brain-machine interface (BMI)-based lower limb exoskeleton control system based on steady-state visual evoked potentials (SSVEPs). Approach. By decoding electroencephalography signals in real-time, users are able to walk forward, turn right, turn left, sit, and stand while wearing the exoskeleton. SSVEP stimulation is implemented with a visual stimulation unit, consisting of five light emitting diodes fixed to the exoskeleton. A canonical correlation analysis (CCA) method for the extraction of frequency information associated with the SSVEP was used in combination with k-nearest neighbors. Main results. Overall, 11 healthy subjects participated in the experiment to evaluate performance. To achieve the best classification, CCA was first calibrated in an offline experiment. In the subsequent online experiment, our results exhibit accuracies of 91.3 ± 5.73%, a response time of 3.28 ± 1.82 s, an information transfer rate of 32.9 ± 9.13 bits/min, and a completion time of 1100 ± 154.92 s for the experimental parcour studied. Significance. The ability to achieve such high quality BMI control indicates that an SSVEP-based lower limb exoskeleton for gait assistance is becoming feasible.

  8. How visualization layout relates to locus of control and other personality factors.

    Science.gov (United States)

    Ziemkiewicz, Caroline; Ottley, Alvitta; Crouser, R Jordan; Yauilla, Ashley Rye; Su, Sara L; Ribarsky, William; Chang, Remco

    2013-07-01

    Existing research suggests that individual personality differences are correlated with a user's speed and accuracy in solving problems with different types of complex visualization systems. We extend this research by isolating factors in personality traits as well as in the visualizations that could have contributed to the observed correlation. We focus on a personality trait known as "locus of control” (LOC), which represents a person's tendency to see themselves as controlled by or in control of external events. To isolate variables of the visualization design, we control extraneous factors such as color, interaction, and labeling. We conduct a user study with four visualizations that gradually shift from a list metaphor to a containment metaphor and compare the participants' speed, accuracy, and preference with their locus of control and other personality factors. Our findings demonstrate that there is indeed a correlation between the two: participants with an internal locus of control perform more poorly with visualizations that employ a containment metaphor, while those with an external locus of control perform well with such visualizations. These results provide evidence for the externalization theory of visualization. Finally, we propose applications of these findings to adaptive visual analytics and visualization evaluation.

  9. Industrial image processing visual quality control in manufacturing

    CERN Document Server

    Demant, Christian; Garnica, Carsten

    2013-01-01

    This practical introduction focuses on how to build integrated solutions to industrial vision problems from individual algorithms. It gives a hands-on guide for setting up automated visual inspection systems using the NeuroCheck software package.

  10. Randomized controlled trial of electro-stimulation therapies to modulate retinal blood flow and visual function in retinitis pigmentosa.

    Science.gov (United States)

    Bittner, Ava K; Seger, Kenneth; Salveson, Rachel; Kayser, Samantha; Morrison, Natalia; Vargas, Patricia; Mendelsohn, Deborah; Han, Jorge; Bi, Hua; Dagnelie, Gislin; Benavente, Alexandra; Ramella-Roman, Jessica

    2017-11-11

    We examined changes in visual function and ocular and retinal blood flow (RBF) among retinitis pigmentosa (RP) participants in a randomized controlled trial of electro-stimulation therapies. Twenty-one RP participants were randomized (1:1:1) to transcorneal electrical stimulation (TES) at 6 weekly half-hour sessions, electro-acupuncture or inactive laser acupuncture (sham control) at 10 half-hour sessions over 2 weeks. Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity (VA), quick contrast sensitivity function, Goldmann visual fields, AdaptDx scotopic sensitivity, spectral flow and colour Doppler imaging of the central retinal artery (CRA), and RBF in macular capillaries were measured twice pre-treatment, after 2 TES sessions, within a week and a month after intervention completion. We measured a significant improvement in retrobulbar CRA mean flow velocity for both the TES (p = 0.038) and electro-acupuncture groups (p = 0.001) on average after 2 weeks of treatment when compared to sham controls. Transcorneal electrical simulation (TES) and electro-acupuncture subjects had significant 55% and 34% greater increases, respectively, in RBF in the macular vessels when compared to sham controls (p < 0.001; p = 0.008) within a week of completing six TES sessions or a month after electro-acupuncture. There was a significant difference in the proportion of eyes that had improved visual function when comparing the three intervention groups (p = 0.038): four of seven TES subjects (57%), two of seven electro-acupuncture subjects (29%) and none of the seven control subjects (0%) had a significant visual improvement outside of typical test-retest variability at two consecutive post-treatment visits. Increased blood flow following electro-stimulation therapies is an objective, physiological change that occurred in addition to visual function improvements in some RP patients. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley

  11. Guideline implementation in clinical practice: Use of statistical process control charts as visual feedback devices

    Directory of Open Access Journals (Sweden)

    Fahad A Al-Hussein

    2009-01-01

    Conclusions: A process of audits in the context of statistical process control is necessary for any improvement in the implementation of guidelines in primary care. Statistical process control charts are an effective means of visual feedback to the care providers.

  12. Optimizing visualization in enhanced depth imaging OCT in healthy subjects and patients with retinal pigment epithelial detachment

    Directory of Open Access Journals (Sweden)

    Kampik A

    2012-11-01

    Full Text Available Lukas Reznicek, Efstathios Vounotrypidis, Florian Seidensticker, Karsten Kortuem, Anselm Kampik, Aljoscha S Neubauer, Armin WolfDepartment of Ophthalmology, Ludwig Maximilians University Muenchen, Munich, GermanyBackground: This study’s objective was to optimize the visualization of three different spectral-domain optical coherence tomography (SD-OCT display modalities and evaluate enhanced depth imaging (EDI by comparing the maximum depth of assessment in conventional versus inverted cross-sectional OCT images in healthy subjects and in patients with retinal pigment epithelial detachment (PED.Methods: Cross-sectional SD-OCT conventional and inverted images were obtained with the HRA2 (Heidelberg Retina Angiograph II, Heidelberg Engineering, Heidelberg, Germany. Horizontal as well as vertical sections in three different display modes were blinded for evaluation by three independent, experienced graders for maximal imaging depth of the deep ocular fundus layers.Results: The mean imaging depth as measured from the inner segment/outer segment (IS/OS to the outer choroid of all 14 healthy subjects was 197 ± 44 µm vs 263 ± 56 µm for conventional vs EDI scans: in black/white mode, it was significantly lower (P < 0.001 than in white/black mode (249 ± 42 µm vs 337 ± 71 µm and color/heat mode (254 ± 48 µm vs 354 ± 73 µm. The mean imaging depth of all 14 study eyes with PED was 240 ± 78 µm vs 345 ± 100 µm for conventional vs EDI scans in black/white mode, and was significantly lower (P < 0.001 than in white/black mode (393 ± 104 µm vs 464 ± 126 µm and in color/heat mode (373 ± 106 µm vs 453 ± 114 µm. In each display modality of healthy subjects and of patients with PED, EDI scans showed a significantly higher imaging depth than the corresponding conventional scans.Conclusion: White/black and color/heat modes allow increased imaging depth, compared to black/white mode using both conventional or EDI OCT scans in healthy subjects or

  13. Haptic Addition to a Visual Menu Selection Interface Controlled by an In-Vehicle Rotary Device

    Directory of Open Access Journals (Sweden)

    Camilla Grane

    2012-01-01

    Full Text Available Today, several vehicles are equipped with a visual display combined with a haptic rotary device for handling in-vehicle information system tasks while driving. This experimental study investigates whether a haptic addition to a visual interface interferes with or supports secondary task performance and whether haptic information could be used without taking eyes off road. Four interfaces were compared during simulated driving: visual only, partly corresponding visual-haptic, fully corresponding visual-haptic, and haptic only. Secondary task performance and subjective mental workload were measured. Additionally, the participants were interviewed. It was found that some haptic support improved performance. However, when more haptic information was used, the results diverged in terms of task completion time and interface comprehension. Some participants did not sense all haptics provided, some did not comprehend the correspondence between the haptic and visual interfaces, and some did. Interestingly, the participants managed to complete the tasks when using haptic-only information.

  14. The Visual Uncertainty Paradigm for Controlling Screen-Space Information in Visualization

    Science.gov (United States)

    Dasgupta, Aritra

    2012-01-01

    The information visualization pipeline serves as a lossy communication channel for presentation of data on a screen-space of limited resolution. The lossy communication is not just a machine-only phenomenon due to information loss caused by translation of data, but also a reflection of the degree to which the human user can comprehend visual…

  15. Usability of a theory of visual attention (TVA) for parameter-based measurement of attention I: evidence from normal subjects

    DEFF Research Database (Denmark)

    Finke, Kathrin; Bublak, Peter; Krummenacher, Joseph

    2005-01-01

    The present study investigated the usability of whole and partial report of briefly displayed letter arrays as a diagnostic tool for the assessment of attentional functions. The tool is based on Bundesen's (1990, 1998, 2002; Bundesen et al., 2005) theory of visual attention (TVA), which assumes f...... four separable attentional components: processing speed, working memory storage capacity, spatial distribution of attention, and top-down control. A number of studies (Duncan et al., 1999; Habekost & Bundesen, 2003; Peers et al., 2005) have already demonstrated the clinical relevance...... clinical tests measuring similar constructs. The empirical independence of the four TVA parameters is suggested by nonsignificant or, in the case of processing speed and working memory storage capacity, only modest correlations between the parameter values....

  16. Neuro fuzzy control of the FES assisted freely swinging leg of paraplegic subjects

    NARCIS (Netherlands)

    van der Spek, J.H.; Velthuis, W.J.R.; Veltink, Petrus H.; de Vries, Theodorus J.A.

    1996-01-01

    The authors designed a neuro fuzzy control strategy for control of cyclical leg movements of paraplegic subjects. The cyclical leg movements were specified by three `swing phase objectives', characteristic of natural human gait. The neuro fuzzy controller is a combination of a fuzzy logic controller

  17. Adding vibrotactile feedback to a myoelectric-controlled hand improves performance when online visual feedback is disturbed.

    Science.gov (United States)

    Raveh, Eitan; Portnoy, Sigal; Friedman, Jason

    2018-01-17

    We investigated whether adding vibrotactile feedback to a myoelectric-controlled hand, when visual feedback is disturbed, can improve performance during a functional test. For this purpose, able-bodied subjects, activating a myoelectric-controlled hand attached to their right hand performed the modified Box & Blocks test, grasping and manipulating wooden blocks over a partition. This was performed in 3 conditions, using a repeated-measures design: in full light, in a dark room where visual feedback was disturbed and no auditory feedback - one time with the addition of tactile feedback provided during object grasping and manipulation, and one time without any tactile feedback. The average time needed to transfer one block was measured, and an infrared camera was used to give information on the number of grasping errors during performance of the test. Our results show that when vibrotactile feedback was provided, performance time was reduced significantly, compared with when no vibrotactile feedback was available. Furthermore, the accuracy of grasping and manipulation was improved, reflected by significantly fewer errors during test performance. In conclusion, adding vibrotactile feedback to a myoelectric-controlled hand has positive effects on functional performance when visual feedback is disturbed. This may have applications to current myoelectric-controlled hands, as adding tactile feedback may help prosthesis users to improve their functional ability during daily life activities in different environments, particularly when limited visual feedback is available or desirable. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Characterization of Visual Scanning Patterns in Air Traffic Control

    Directory of Open Access Journals (Sweden)

    Sarah N. McClung

    2016-01-01

    Full Text Available Characterization of air traffic controllers’ (ATCs’ visual scanning strategies is a challenging issue due to the dynamic movement of multiple aircraft and increasing complexity of scanpaths (order of eye fixations and saccades over time. Additionally, terminologies and methods are lacking to accurately characterize the eye tracking data into simplified visual scanning strategies linguistically expressed by ATCs. As an intermediate step to automate the characterization classification process, we (1 defined and developed new concepts to systematically filter complex visual scanpaths into simpler and more manageable forms and (2 developed procedures to map visual scanpaths with linguistic inputs to reduce the human judgement bias during interrater agreement. The developed concepts and procedures were applied to investigating the visual scanpaths of expert ATCs using scenarios with different aircraft congestion levels. Furthermore, oculomotor trends were analyzed to identify the influence of aircraft congestion on scan time and number of comparisons among aircraft. The findings show that (1 the scanpaths filtered at the highest intensity led to more consistent mapping with the ATCs’ linguistic inputs, (2 the pattern classification occurrences differed between scenarios, and (3 increasing aircraft congestion caused increased scan times and aircraft pairwise comparisons. The results provide a foundation for better characterizing complex scanpaths in a dynamic task and automating the analysis process.

  19. Combining electroencephalographic activity and instantaneous heart rate for assessing brain-heart dynamics during visual emotional elicitation in healthy subjects.

    Science.gov (United States)

    Valenza, G; Greco, A; Gentili, C; Lanata, A; Sebastiani, L; Menicucci, D; Gemignani, A; Scilingo, E P

    2016-05-13

    Emotion perception, occurring in brain areas such as the prefrontal cortex and amygdala, involves autonomic responses affecting cardiovascular dynamics. However, how such brain-heart dynamics is further modulated by emotional valence (pleasantness/unpleasantness), also considering different arousing levels (the intensity of the emotional stimuli), is still unknown. To this extent, we combined electroencephalographic (EEG) dynamics and instantaneous heart rate estimates to study emotional processing in healthy subjects. Twenty-two healthy volunteers were elicited through affective pictures gathered from the International Affective Picture System. The experimental protocol foresaw 110 pictures, each of which lasted 10 s, associated to 25 different combinations of arousal and valence levels, including neutral elicitations. EEG data were processed using short-time Fourier transforms to obtain time-varying maps of cortical activation, whereas the associated instantaneous cardiovascular dynamics was estimated in the time and frequency domains through inhomogeneous point-process models. Brain-heart linear and nonlinear coupling was estimated through the maximal information coefficient (MIC). Considering EEG oscillations in theθband (4-8 Hz), MIC highlighted significant arousal-dependent changes between positive and negative stimuli, especially occurring at intermediate arousing levels through the prefrontal cortex interplay. Moreover, high arousing elicitations seem to mitigate changes in brain-heart dynamics in response to pleasant/unpleasant visual elicitation. © 2016 The Author(s).

  20. A deep learning / neuroevolution hybrid for visual control

    DEFF Research Database (Denmark)

    Poulsen, Andreas Precht; Thorhauge, Mark; Funch, Mikkel Hvilshj

    2017-01-01

    This paper presents a deep learning / neuroevolution hybrid approach called DLNE, which allows FPS bots to learn to aim & shoot based only on high-dimensional raw pixel input. The deep learning component is responsible for visual recognition and translating raw pixels to compact feature...... representations, while the evolving network takes those features as inputs to infer actions. The results suggest that combining deep learning and neuroevolution in a hybrid approach is a promising research direction that could make complex visual domains directly accessible to networks trained through evolution....

  1. Optimisation of underwater visual census and controlled angling ...

    African Journals Online (AJOL)

    Standardised sampling protocols for monitoring fish stocks are essential to assess changes in stock status and provide a means to evaluate the effectiveness of fisheries management measures, such as marine protected areas (MPAs). This study aimed to optimise two standard sampling methods, namely underwater visual ...

  2. Effects of visual demonstration, verbal instructions, and prompted verbal descriptions on the performance of human subjects in conditional discriminations

    OpenAIRE

    Ribes-Iñesta, Emilio; Cepeda, Ma. Luisa; Hickman, Hortencia; Moreno, Diana; Peñalosa, Eduardo

    1992-01-01

    A study was conducted to confirm prior results concerning the role of prompted verbal descriptions of visually demonstrated stimulus relations in the acquisition and transfer of identity, difference, and similarity-matching relations (Ribes et al., 1988). Four groups of human adults were trained with these three matching relations under four different procedures: (1) visual demonstration without response requirement, (2) verbal instructions, (3) visual demonstration plus prompted verbal descr...

  3. Evidence-Based Communication Practices for Children with Visual Impairments and Additional Disabilities: An Examination of Single-Subject Design Studies

    Science.gov (United States)

    Parker, Amy T.; Grimmett, Eric S.; Summers, Sharon

    2008-01-01

    This review examines practices for building effective communication strategies for children with visual impairments, including those with additional disabilities, that have been tested by single-subject design methodology. The authors found 30 studies that met the search criteria and grouped intervention strategies to align any evidence of the…

  4. Perceptions, Attitudes and Institutional Factors That Influence Academic Performance of Visual Arts Students in Ghana's Senior High School Core Curriculum Subjects

    Science.gov (United States)

    Opoku-Asare, Nana Afia; Tachie-Menson, Akosua; Essel, Harry Barton

    2015-01-01

    Senior High School (SHS) students in Ghana are required to pass all core and elective curricula subjects in the West Africa Senior School Certificate Examination (WASSCE) to qualify for higher education. Unfortunately, many Visual Arts students perform poorly or fail in English, Mathematics, Integrated Science and Social Studies, which constitute…

  5. Effects of food on cortisol and mood in vulnerable subjects under controllable and uncontrollable stress

    NARCIS (Netherlands)

    Markus, R.; Panhuysen, G.; Tuiten, A.; Koppeschaar, H.

    2000-01-01

    The aim of this study was to investigate whether in stress-prone subjects, carbohydrate-rich, protein-poor food (CR/PP) diminished depressive mood and a cortisol response under controllable as well as uncontrollable laboratory stress. Twenty-two subjects with high stress proneness (HS) and 23

  6. Top-down and bottom-up control of visual selection.

    NARCIS (Netherlands)

    Theeuwes, J.; Itti, L.; Fecteau, J.

    2005-01-01

    The present paper argues for the notion that when attention is spread across the visual field in the first sweep of information through the brain visual selection is completely stimulus-driven. Only later in time, through recurrent feedback processing, volitional control based on expectancy and goal

  7. Top-down and bottom-up control of visual selection

    NARCIS (Netherlands)

    Theeuwes, J.

    2010-01-01

    The present paper argues for the notion that when attention is spread across the visual field in the first sweep of information through the brain visual selection is completely stimulus-driven. Only later in time, through recurrent feedback processing, volitional control based on expectancy and goal

  8. Landscape control points: a procedure for predicting and monitoring visual impacts

    Science.gov (United States)

    R. Burton Litton

    1973-01-01

    The visual impacts of alterations to the landscape can be studied by setting up Landscape Control Points–a network of permanently established observation sites. Such observations enable the forest manager to anticipate visual impacts of management decision, select from a choice of alternative solutions, cover an area for comprehensive viewing, and establish a method to...

  9. The Impact of Baseline Trend Control on Visual Analysis of Single-Case Data

    Science.gov (United States)

    Mercer, Sterett H.; Sterling, Heather E.

    2012-01-01

    The impact of baseline trend control on visual analyses of AB intervention graphs was examined with simulated data at various values of baseline trend, autocorrelation, and effect size. Participants included 202 undergraduate students with minimal training in visual analysis and 10 graduate students and faculty with more training and experience in…

  10. Visual-Proprioceptive Cue Conflicts in the Control of Remotely Piloted Vehicles

    Science.gov (United States)

    1977-09-01

    entitled "The Effects of Visual- Propioceptive Cue Conflicts on Human Tracking Performance" presented to The Ohio State University, March 1977. The author...concluded that the incompatible conditions (i.e, conflicts rather than by random control activities. SAl and DAI) produced visual propioceptive Thus, it

  11. Synaesthetic perception of colour and visual space in a blind subject: an fMRI case study.

    Science.gov (United States)

    Niccolai, Valentina; van Leeuwen, Tessa M; Blakemore, Colin; Stoerig, Petra

    2012-06-01

    In spatial sequence synaesthesia (SSS) ordinal stimuli are perceived as arranged in peripersonal space. Using fMRI, we examined the neural bases of SSS and colour synaesthesia for spoken words in a late-blind synaesthete, JF. He reported days of the week and months of the year as both coloured and spatially ordered in peripersonal space; parts of the days and festivities of the year were spatially ordered but uncoloured. Words that denote time-units and triggered no concurrents were used in a control condition. Both conditions inducing SSS activated the occipito-parietal, infero-frontal and insular cortex. The colour area hOC4v was engaged when the synaesthetic experience included colour. These results confirm the continued recruitment of visual colour cortex in this late-blind synaesthetes. Synaesthesia also involved activation in inferior frontal cortex, which may be related to spatial memory and detection, and in the insula, which might contribute to audiovisual integration related to the processing of inducers and concurrents. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Study of Auditory, Visual Reaction Time and Glycemic Control (HBA1C) in Chronic Type II Diabetes Mellitus.

    Science.gov (United States)

    M, Muhil; Sembian, Umapathy; Babitha; N, Ethiya; K, Muthuselvi

    2014-09-01

    Diabetes mellitus is a disease of insulin deficiencyleads to micro and macro vascular disorder. Neuropathy is one of the major complication of chronic uncontrolled Diabetes affecting the Reaction time. To study the correlation between the glycosylated HbA1C and Auditory, visual Reaction time in chronic Type II diabetes (40-60y) of on oral hypoglycemic drugs of>10 y duration in two groups (n-100 in each group , both Males & females) and compared within the study groups and also with the age matched control group (100). HbA1C-Glycosylated HbA1C was measured by Particle enhanced immunoturbidimetric test method. Auditory and visual reaction time (ART, VRT) were measured by PC 1000 Reaction timer for control & study groups i.e. Group-I - Chronic Type II DM for >10 y with HbA1c 10 y with HbA1c > 7.0 ie impaired glycemic control. Exclusion Criteria- Subjects with Auditory and visual disturbances, alcoholism and smoking. Statistical Analysis - One-way ANOVA. Using SPSS 21 software. Both the groups had prolonged ART and VRT than controls. Among the study group, G-II (DM with HbA1C >7) had increased Auditory & Visual Reaction time than Group I which is statistically significant p-value 7 who have shown increased Auditory and Visual Reaction time than chronic DM with HbA1C<7.Severity of Peripheral neuropathy in Type II Diabetics could be due to elevated HbA1C.

  13. Intrinsic, identified, and controlled types of motivation for school subjects in young elementary school children.

    Science.gov (United States)

    Guay, Frédéric; Chanal, Julien; Ratelle, Catherine F; Marsh, Herbert W; Larose, Simon; Boivin, Michel

    2010-12-01

    There are two approaches to the differential examination of school motivation. The first is to examine motivation towards specific school subjects (between school subject differentiation). The second is to examine school motivation as a multidimensional concept that varies in terms of not only intensity but also quality (within school subject differentiation). These two differential approaches have led to important discoveries and provided a better understanding of student motivational dynamics. However, little research has combined these two approaches. This study examines young elementary students' motivations across school subjects (writing, reading, and maths) from the stance of self-determination theory. First, we tested whether children self-report different levels of intrinsic, identified, and controlled motivation towards specific school subjects. Second, we verified whether children self-report differentiated types of motivation across school subjects. Participants were 425 French-Canadian children (225 girls, 200 boys) from three elementary schools. Children were in Grades 1 (N=121), 2 (N=126), and 3 (N=178). Results show that, for a given school subject, young elementary students self-report different levels of intrinsic, identified, and controlled motivation. Results also indicate that children self-report different levels of motivation types across school subjects. Our findings also show that most differentiation effects increase across grades. Some gender effects were also observed. These results highlight the importance of distinguishing among types of school motivation towards specific school subjects in the early elementary years.

  14. Experimental System for Investigation of Visual Sensory Input in Postural Feedback Control

    Directory of Open Access Journals (Sweden)

    Jozef Pucik

    2012-01-01

    Full Text Available The human postural control system represents a biological feedback system responsible for maintenance of upright stance. Vestibular, proprioceptive and visual sensory inputs provide the most important information into the control system, which controls body centre of mass (COM in order to stabilize the human body resembling an inverted pendulum. The COM can be measured indirectly by means of a force plate as the centre of pressure (COP. Clinically used measurement method is referred to as posturography. In this paper, the conventional static posturography is extended by visual stimulation, which provides insight into a role of visual information in balance control. Visual stimuli have been designed to induce body sway in four specific directions – forward, backward, left and right. Stabilograms were measured using proposed single-PC based system and processed to calculate velocity waveforms and posturographic parameters. The parameters extracted from pre-stimulus and on-stimulus periods exhibit statistically significant differences.

  15. Visual Problem Solving and Self‐regulation in Training Air Traffic Control

    NARCIS (Netherlands)

    Meeuwen van, Ludo

    2015-01-01

    Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.

  16. Visual problem solving and self-regulation in training air traffic control

    NARCIS (Netherlands)

    Van Meeuwen, Ludo

    2013-01-01

    Van Meeuwen, L. W. (2013). Visual problem solving and self-regulation in training air traffic control (Unpublished doctoral dissertation). Centre for Learning Sciences and Technologies, Open Universiteit, Heerlen, The Netherlands.

  17. Benefit of bi-ocular visual stimulation for postural control in children with strabismus.

    Science.gov (United States)

    Gaertner, Chrystal; Creux, Charlotte; Espinasse-Berrod, Marie-Andrée; Orssaud, Christophe; Dufier, Jean-Louis; Kapoula, Zoï

    2013-01-01

    Vision is important for postural control as is shown by the Romberg quotient (RQ): with eyes closed, postural instability increases relative to eyes open (RQ = 2). Yet while fixating at far distance, postural stability is similar with eyes open and eyes closed (RQ = 1). Postural stability can be better with both eyes viewing than one eye, but such effect is not consistent among healthy subjects. The first goal of the study is to test the RQ as a function of distance for children with convergent versus divergent strabismus. The second goal is to test whether vision from two eyes relative to vision from one eye provides better postural stability. Thirteen children with divergent strabismus and eleven with convergent strabismus participated in this study. Posturtography was done with the Techno concept device. Experiment 1, four conditions: fixation at 40 cm and at 200 cm both with eyes open and eyes covered (evaluation of RQ). Experiment 2, six conditions: fixation at 40 cm and at 200 cm, with both eyes viewing or under monocular vision (dominant and non-dominant eye). For convergent strabismus, the groups mean value of RQ was 1.3 at near and 0.94 at far distance; for divergent, it was 1.06 at near and 1.68 at far. For all children, the surface of body sway was significantly smaller under both eyes viewing than monocular viewing (either eye). Increased RQ value at near for convergent and at far for divergent strabismus is attributed to the influence of the default strabismus angle and to better use of ocular motor signals. Vision with the two eyes improves postural control for both viewing distances and for both types of strabismus. Such benefit can be due to complementary mechanisms: larger visual field, better quality of fixation and vergence angle due to the use of visual inputs from both eyes.

  18. Benefit of bi-ocular visual stimulation for postural control in children with strabismus.

    Directory of Open Access Journals (Sweden)

    Chrystal Gaertner

    Full Text Available Vision is important for postural control as is shown by the Romberg quotient (RQ: with eyes closed, postural instability increases relative to eyes open (RQ = 2. Yet while fixating at far distance, postural stability is similar with eyes open and eyes closed (RQ = 1. Postural stability can be better with both eyes viewing than one eye, but such effect is not consistent among healthy subjects. The first goal of the study is to test the RQ as a function of distance for children with convergent versus divergent strabismus. The second goal is to test whether vision from two eyes relative to vision from one eye provides better postural stability. Thirteen children with divergent strabismus and eleven with convergent strabismus participated in this study. Posturtography was done with the Techno concept device. Experiment 1, four conditions: fixation at 40 cm and at 200 cm both with eyes open and eyes covered (evaluation of RQ. Experiment 2, six conditions: fixation at 40 cm and at 200 cm, with both eyes viewing or under monocular vision (dominant and non-dominant eye. For convergent strabismus, the groups mean value of RQ was 1.3 at near and 0.94 at far distance; for divergent, it was 1.06 at near and 1.68 at far. For all children, the surface of body sway was significantly smaller under both eyes viewing than monocular viewing (either eye. Increased RQ value at near for convergent and at far for divergent strabismus is attributed to the influence of the default strabismus angle and to better use of ocular motor signals. Vision with the two eyes improves postural control for both viewing distances and for both types of strabismus. Such benefit can be due to complementary mechanisms: larger visual field, better quality of fixation and vergence angle due to the use of visual inputs from both eyes.

  19. Programmed Control of Optical Grating Scales for Visual Research.

    Science.gov (United States)

    1980-12-01

    DEC 80 K L MARTINDALE UNCLASSI FI/EOAFI /G /E IA D2 NL [-hii document hapi beax Oppo~ DTIC to pbu rk~ meatCaELECTF r~ DEPARTMENT OF THE AIR FORCE...spent much time and effort in visual studies. Work has been done on the modulation trans- fer function of the eye (Ref 1), the center-surround...problems incurred in con- struction. Finally, Section V will present conclusions and recommendations for future work or expansion. ~, 𔃾 I II Design

  20. Visual-Motor Control of Steering and Awareness of Performance

    Directory of Open Access Journals (Sweden)

    Callum Mole

    2012-05-01

    Full Text Available In order to carry out skilled, visually guided actions, humans need to be able to use feedback to monitor and adjust performance. Such feedback can be relatively low level, with some motor commands being recalibrated rapidly based on visual feedback with little cognitive awareness (eg, Mon-Williams and Murray 2000. In tasks such as driving, however, awareness of performance could be important for making strategic adjustments in order to respond to road conditions. To investigate whether participants could accurately gauge steering performance, we used a simulated driving scenario. Participants (n=30 were required to steer around a series of bends and stay within a central marked zone. In order to alter the task demands, the speed of travel (fast/slow and the width of the zone (narrow/wide were manipulated. After each bend the participants made an explicit percentage judgment of time spent within the required zone. The mean group steering results showed that performance was worst for faster speeds and narrower zones, and this pattern was matched in the awareness judgements. Closer inspection of the data, however, showed that at an individual level these judgements often failed to capture trial performance and were often merely influenced by the visible task characteristics (eg, fast and narrow trial. This suggests that participants may erroneously rely on salient cues about task characteristics to assess performance if direct feedback is weak. This has important implications for driving since individuals may be failing to respond to situation characteristics that actually make performance worse.

  1. Controlled vaporized cannabis, with and without alcohol: subjective effects and oral fluid-blood cannabinoid relationships.

    Science.gov (United States)

    Hartman, Rebecca L; Brown, Timothy L; Milavetz, Gary; Spurgin, Andrew; Gorelick, David A; Gaffney, Gary; Huestis, Marilyn A

    2016-07-01

    Vaporized cannabis and concurrent cannabis and alcohol intake are commonplace. We evaluated the subjective effects of cannabis, with and without alcohol, relative to blood and oral fluid (OF, advantageous for cannabis exposure screening) cannabinoid concentrations and OF/blood and OF/plasma vaporized-cannabinoid relationships. Healthy adult occasional-to-moderate cannabis smokers received a vaporized placebo or active cannabis (2.9% and 6.7% Δ(9) -tetrahydrocannabinol, THC) with or without oral low-dose alcohol (~0.065g/210L peak breath alcohol concentration [BrAC]) in a within-subjects design. Blood and OF were collected up to 8.3 h post-dose and subjective effects measured at matched time points with visual-analogue scales and 5-point Likert scales. Linear mixed models evaluated subjective effects by THC concentration, BrAC, and interactions. Effects by time point were evaluated by dose-wise analysis of variance (ANOVA). OF versus blood or plasma cannabinoid ratios and correlations were evaluated in paired-positive specimens. Nineteen participants (13 men) completed the study. Blood THC concentration or BrAC significantly associated with subjective effects including 'high', while OF contamination prevented significant OF concentration associations Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Voluntary control of corticomuscular coherence through neurofeedback: a proof-of-principle study in healthy subjects.

    Science.gov (United States)

    von Carlowitz-Ghori, K; Bayraktaroglu, Z; Waterstraat, G; Curio, G; Nikulin, V V

    2015-04-02

    Corticomuscular coherence (CMC) relates to synchronization between activity in the motor cortex and the muscle activity. The strength of CMC can be affected by motor behavior. In a proof-of-principle study, we examined whether independent of motor output parameters, healthy subjects are able to voluntarily modulate CMC in a neurofeedback paradigm. Subjects received visual online feedback of their instantaneous CMC strength, which was calculated between an optimized spatial projection of multichannel electroencephalography (EEG) and electromyography (EMG) in an individually defined target frequency range. The neurofeedback training consisted of either increasing or decreasing CMC strength using a self-chosen mental strategy while performing a simple motor task. Evaluation of instantaneous coherence showed that CMC strength was significantly larger when subjects had to increase than when to decrease CMC; this difference between the two task conditions did not depend on motor performance. The exclusion of confounding factors such as motor performance, attention and task complexity in study design provides evidence that subjects were able to voluntarily modify CMC independent of motor output parameters. Additional analysis further strengthened the assumption that the subjects' response was specifically shaped by the neurofeedback. In perspective, we suggest that CMC-based neurofeedback could provide a therapeutic approach in clinical conditions, such as motor stroke, where CMC is altered. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. Self Esteem, Locus of Control and Multidimensional Perfectionism as the Predictors of Subjective Well Being

    Science.gov (United States)

    Karatas, Zeynep; Tagay, Ozlem

    2012-01-01

    The purpose of this study is to determine whether there is a relationship between self-esteem, locus of control and multidimensional perfectionism, and the extent to which the variables of self-esteem, locus of control and multidimensional perfectionism contribute to the prediction of subjective well-being. The study was carried out with 318 final…

  4. Visual Control of Autonomous Vehicle by Neural Networks Using Fuzzy-Supervised Learning

    Energy Technology Data Exchange (ETDEWEB)

    Ryoo, Young Jae [Kumho Information and Telecommunications Laboratory, Kwangju (Korea, Republic of); Lim, Young Cheol [Cheonnam National University, Kwangju (Korea, Republic of)

    1997-04-01

    This paper describes a control scheme for an autonomous vehicle with visual sensors, which uses visual information to guide itself along roadways. The control system integrates visual data into the steering servo process directly, instead of subdividing the process by geometric reasoning for a vehicle-centered representation of the road from two-dimensional visual image data. A neural network using fuzzy-supervised learning is used for determining the steering angle required to move the vanishing point and vanishing line of the road to the desired position in the camera image. The validity and the effectiveness of the proposed control scheme are confirmed by a computer simulation of the autonomous vehicle`s driving performance. (author). 12 refs., 8 figs., 4 tabs.

  5. Metacognitive monitoring and control in visual change detection: Implications for situation awareness and cognitive control.

    Directory of Open Access Journals (Sweden)

    Ken I McAnally

    Full Text Available Metacognitive monitoring and control of situation awareness (SA are important for a range of safety-critical roles (e.g., air traffic control, military command and control. We examined the factors affecting these processes using a visual change detection task that included representative tactical displays. SA was assessed by asking novice observers to detect changes to a tactical display. Metacognitive monitoring was assessed by asking observers to estimate the probability that they would correctly detect a change, either after study of the display and before the change (judgement of learning; JOL or after the change and detection response (judgement of performance; JOP. In Experiment 1, observers failed to detect some changes to the display, indicating imperfect SA, but JOPs were reasonably well calibrated to objective performance. Experiment 2 examined JOLs and JOPs in two task contexts: with study-time limits imposed by the task or with self-pacing to meet specified performance targets. JOPs were well calibrated in both conditions as were JOLs for high performance targets. In summary, observers had limited SA, but good insight about their performance and learning for high performance targets and allocated study time appropriately.

  6. Determination of skin temperature under a comfort-controlled liquid-cooled garment in exercising subjects

    Science.gov (United States)

    Santamaria, L. J.

    1971-01-01

    The physiological responses of exercising subjects were investigated under conditions in which the temperature of the coolant water was varied according to the subjective state of thermal comfort. Conditioning water was maintained at a constant flow rate of 240 lb/hr and at a temperature controllable within the range of 45 to 90 F. In addition to skin temperatures, rectal temperature and heart rate were monitored in the course of each trial. Total and evaporative weight losses were determined by measurements before and after each test. The levels on metabolic loading, measured indirectly on the basis of O2 consumption in the course of treadmill activity, ranged from the resting state to 2000 BTU/hr at increments of about 400 BTU. Under the experimental conditions, six volunteer subjects established a level of thermal comfort, as sensed subjectively, by controlling inlet water within the available range of temperature.

  7. Comparison for aphasic and control subjects of eye movements hypothesized in neurolinguistic programming.

    Science.gov (United States)

    Dooley, K O; Farmer, A

    1988-08-01

    Neurolinguistic programming's hypothesized eye movements were measured independently using videotapes of 10 nonfluent aphasic and 10 control subjects matched for age and sex. Chi-squared analysis indicated that eye-position responses were significantly different for the groups. Although earlier research has not supported the hypothesized eye positions for normal subjects, the present findings support the contention that eye-position responses may differ between neurologically normal and aphasic individuals.

  8. Digital media promoting new approaches to subject specific didactics in visual arts education in primary school, high school, teacher education and university education

    DEFF Research Database (Denmark)

    Buhl, Mie; Örtegren, Hans; Haïkö, Tarja

    The symposium discusses eventual paradigmatic shift within Art Education at different levels when new tools for creation are applied in educational settings. The symposium addresses current developments in visual arts education based on empirical projects from different levels of the educational...... system. The purpose is to discuss to which extend digital media can be seen as an integrated part of existing theory mainly based on developments from analog media or rather give rise to think subject specific didactics differently. Recent developments like visual culture, contemporary arts, social...... aesthetics, community art and co-creation all represent an approach to art production and appreciation where content, media and visual expressions unfold in societal, digital, collaborative, and transgressive constellations involving the art maker and audiences in social and relational projects processes...

  9. Vcs.js - Visualization Control System for the Web

    Science.gov (United States)

    Chaudhary, A.; Lipsa, D.; Doutriaux, C.; Beezley, J. D.; Williams, D. N.; Fries, S.; Harris, M. B.

    2016-12-01

    VCS is a general purpose visualization library, optimized for climate data, which is part of the UV-CDAT system. It provides a Python API for drawing 2D plots such as lineplots, scatter plots, Taylor diagrams, data colored by scalar values, vector glyphs, isocontours and map projections. VCS is based on the VTK library. Vcs.js is the corresponding JavaScript API, designed to be as close as possible to the original VCS Python API and to provide similar functionality for the Web. Vcs.js includes additional functionality when compared with VCS. This additional API is used to introspect data files available on the server and variables available in a data file. Vcs.js can display plots in the browser window. It always works with a server that reads a data file, extracts variables from the file and subsets the data. From this point, two alternate paths are possible. First the system can render the data on the server using VCS producing an image which is send to the browser to be displayed. This path works for for all plot types and produces a reference image identical with the images produced by VCS. This path uses the VTK-Web library. As an optimization, usable in certain conditions, a second path is possible. Data is packed, and sent to the browser which uses a JavaScript plotting library, such as plotly, to display the data. Plots that work well in the browser are line-plots, scatter-plots for any data and many other plot types for small data and supported grid types. As web technology matures, more plots could be supported for rendering in the browser. Rendering can be done either on the client or on the server and we expect that the best place to render will change depending on the available web technology, data transfer costs, server management costs and value provided to users. We intend to provide a flexible solution that allows for both client and server side rendering and a meaningful way to choose between the two. We provide a web-based user interface called v

  10. Learning effects of dynamic postural control by auditory biofeedback versus visual biofeedback training.

    Science.gov (United States)

    Hasegawa, Naoya; Takeda, Kenta; Sakuma, Moe; Mani, Hiroki; Maejima, Hiroshi; Asaka, Tadayoshi

    2017-10-01

    Augmented sensory biofeedback (BF) for postural control is widely used to improve postural stability. However, the effective sensory information in BF systems of motor learning for postural control is still unknown. The purpose of this study was to investigate the learning effects of visual versus auditory BF training in dynamic postural control. Eighteen healthy young adults were randomly divided into two groups (visual BF and auditory BF). In test sessions, participants were asked to bring the real-time center of pressure (COP) in line with a hidden target by body sway in the sagittal plane. The target moved in seven cycles of sine curves at 0.23Hz in the vertical direction on a monitor. In training sessions, the visual and auditory BF groups were required to change the magnitude of a visual circle and a sound, respectively, according to the distance between the COP and target in order to reach the target. The perceptual magnitudes of visual and auditory BF were equalized according to Stevens' power law. At the retention test, the auditory but not visual BF group demonstrated decreased postural performance errors in both the spatial and temporal parameters under the no-feedback condition. These findings suggest that visual BF increases the dependence on visual information to control postural performance, while auditory BF may enhance the integration of the proprioceptive sensory system, which contributes to motor learning without BF. These results suggest that auditory BF training improves motor learning of dynamic postural control. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Evaluation of P300 components for emotion-loaded visual event-related potential in elderly subjects, including those with dementia.

    Science.gov (United States)

    Asaumi, Yasue; Morita, Kiichiro; Nakashima, Youko; Muraoka, Akemi; Uchimura, Naohisa

    2014-07-01

    In the present study, the P300 component of the emotion-loaded visual event-related potential in response to photographs of babies crying or smiling was measured to evaluate cognitive function in elderly subjects, including those with dementia. The subjects were 48 elderly people who consulted a memory disorder clinic. The visual event-related potential was measured using oddball tasks. Brain waves were recorded from four sites. We analyzed the P300 amplitude and latency. Subjects were divided into three groups (the dementia with Alzheimer's disease group [ADG]; the intermediate group [MG], and the healthy group [HG]) based on the Revised Hasegawa Dementia Scale, Mini-mental State Examination scores and the Clinical Dementia Rating. For all subjects, there was a significant positive correlation between P300 latency and Z-score of voxel-based specific regional analysis for Alzheimer's disease for crying or smiling faces. There was a negative correlation between P300 amplitude and Z-score for the crying face. MG subjects were divided into two groups (high risk: HRMG, low risk: LRMG) based on Z-scores (HRMG ≥ 2.0). The P300 amplitude of ADG was significantly smaller than that of HG, and the P300 latency of ADG was significantly longer than those of other groups for crying or smiling faces. The P300 latency of HRMG was significantly longer than that of LRMG for the smiling face. Furthermore, the P300 latency for the crying face was significantly shorter than that for the smiling face in HG and ADG. These findings suggest that analysis of P300 components of the emotion-loaded visual event-related potential may be a useful neuropsychological index for the diagnosis of Alzheimer's disease and high-risk subjects. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

  12. Visual Recognition and Its Application to Robot Arm Control

    National Research Council Canada - National Science Library

    Juang, Jih-Gau; Tsai, Yi-Ju; Fan, Yang-Wu

    2015-01-01

    .... The system consists of a robot arm and two webcams. After the words from the control panel that represent commands are recognized by the robot system, the robot arm performs the corresponding actions to test the smartphone...

  13. Visual impairment, but not hearing impairment, is independently associated with lower subjective well-being among individuals over 95 years of age: A population-based study.

    Science.gov (United States)

    Liu, Zuyun; Wu, Di; Huang, Jiapin; Qian, Degui; Chen, Fei; Xu, Jun; Li, Shilin; Jin, Li; Wang, Xiaofeng

    2016-01-01

    Sensory impairment affects an increasing number of elderly adults, with a negative psychological impact. Our objective was to examine the associations of visual and hearing impairment with subjective well-being (SWB), an important psychological concept defined by life satisfaction [LS], positive affect [PA], negative affect [NA], and affect balance [AB] among long-lived individuals (LLIs) over 95 years of age. Data on 442 LLIs from the Rugao longevity cohort, a population-based study in Rugao, China, were analyzed. Graded classifications of visual and hearing impairment (none, mild, moderate, and severe) were constructed from self-reported items. Bivariate correlation and multiple regression analysis were performed to test the associations. Approximately 66.1% and 87.3% of the subjects reported varying degrees of visual and hearing impairment. Following the degree of vision impairment, LS, PA, and AB decreased linearly, whereas NA increased linearly (all p for trendimpairment with LS, NA, and AB, while diminished, still existed. Visual impairment, but not hearing impairment, was independently associated with low SWB among LLIs, and functional ability may play a mediating role in the observed relationship. The findings indicate that rehabilitation targeted for those with reduced vision and functioning in long-lived populations may be important for promoting well-being and quality of life. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. No evidence of a lower visual field specialization for visuomotor control.

    Science.gov (United States)

    Binsted, Gord; Heath, Matthew

    2005-03-01

    The lower visual field (loVF) has been hypothesized to demonstrate specialization for skilled, visually guided action. According to Danckert and Goodale, this visual field asymmetry indirectly suggests that the loVF has privileged connections to visuomotor networks within the dorsal visual pathway. Here we attempted to replicate the loVF advantage during the execution of a discrete aiming movement to targets of various widths (index of difficulty ranging from 1.5 to 5 bits). In addition, we employed trials in which vision of the target object was available or unavailable during the reaching movement to determine whether or not the purported visual field asymmetry reflects enhanced central planning (i.e., feedforward) or online control (i.e., feedback) processes. Reaching trajectories were examined for indicators of online amendments, and movement times and endpoint characteristics were examined to quantify possible visual field asymmetries in relative speed/accuracy trade-offs. In terms of reaching kinematics, it was found that vision of the target during the reaching movement resulted in greater online control of the reaching trajectory; however, no significant main effects or interactions involving visual field were observed. In other words, fixating in the upper or the lower region of peripersonal space did not influence the nature of reaching control (i.e., feedback vs. feedforward). Most importantly, our movement time and endpoint accuracy data elicited a robust speed/accuracy trade-off in both upper and lower regions of working space. Thus, and contrary to previous findings (such as those reported by Danckert and Goodale), the indices of difficulty coupled with the discrete aiming task used here did not elicit a lower visual field advantage for visually guided action.

  15. Visual Recognition and Its Application to Robot Arm Control

    Directory of Open Access Journals (Sweden)

    Jih-Gau Juang

    2015-10-01

    Full Text Available This paper presents an application of optical word recognition and fuzzy control to a smartphone automatic test system. The system consists of a robot arm and two webcams. After the words from the control panel that represent commands are recognized by the robot system, the robot arm performs the corresponding actions to test the smartphone. One of the webcams is utilized to capture commands on the screen of the control panel, the other to recognize the words on the screen of the tested smartphone. The method of image processing is based on the Red-Green-Blue (RGB and Hue-Saturation-Luminance (HSL color spaces to reduce the influence of light. Fuzzy theory is used in the robot arm’s position control. The Optical Character Recognition (OCR technique is applied to the word recognition, and the recognition results are then checked by a dictionary process to increase the recognition accuracy. The camera which is used to recognize the tested smartphone also provides object coordinates to the fuzzy controller, then the robot arm moves to the desired positions and presses the desired buttons. The proposed control scheme allows the robot arm to perform different assigned test functions successfully.

  16. Collaboration Between Art Teacher Students and Communication and Digital Media Students Promoting Subject Specific Didactics in Digital Visual Learning Design

    DEFF Research Database (Denmark)

    Buhl, Mie; Skov, Kirsten

    design was based on the purpose of involving the future users in developing a visual learning design, and thereby drawing on visual art expertise in all phases of the design. The Design Based Research (DBR) approach (Amiel & Reeves 2008) was chosen in order to facilitate the collaborative aspect......, No. 15, 2016, p. 1-21 Buhl, M. & Ejsing-Duun (2015) Blended learning promoting new developments for Nordic master programs in visual studies and art education, ECEL Proceedings, Hatfield Buhl, M. & Flensborg (2011). Visuel kulturpædagogik, København: Hans Reitzels Forlag Peppler, K. (2010). Media...... arts: Arts education for a digital age. Teachers College Record, vol 112, nr. 8, p. 2118-2153 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.700.7662&rep=rep1&type=pdf Dunleavy, M. & Dede, C. (2014). Augmented reality teaching and learning. in. J.M. Spector, M.D. Merrill, J. Elen & M...

  17. A randomized controlled trial: the effect of inulin on weight management and ectopic fat in subjects with prediabetes.

    Science.gov (United States)

    Guess, Nicola D; Dornhorst, Anne; Oliver, Nick; Bell, Jimmy D; Thomas, E Louise; Frost, Gary S

    2015-01-01

    Fat infiltration of the liver, muscle and pancreas is associated with insulin resistance and risk of diabetes. Weight loss reduces ectopic fat deposition and risk of diabetes, but is difficult to sustain to due to compensatory increases in appetite. Fermentable carbohydrates have been shown to decrease appetite and food intake, and promote weight loss in overweight subjects. In animal studies, fermentable carbohydrate reduces ectopic fat independent of weight loss. We aimed to investigate the effect of the fermentable carbohydrate inulin on weight maintenance, appetite and ectopic fat in subjects with prediabetes. Forty-four subjects with prediabetes were randomized to 18 weeks' inulin or cellulose supplementation. During weeks 1-9 (weight loss phase) all subjects had four visits with a dietitian to guide them towards a 5 % weight loss. During weeks 10-18 (weight maintenance phase) subjects continued taking their assigned supplementation and were asked to maintain the weight they had lost but were offered no further support. All subjects attended study sessions at baseline, 9 and 18 weeks for measurement of weight; assessment of adipose tissue and ectopic fat content by magnetic resonance imaging and magnetic resonance spectroscopy; glucose, insulin and GLP-1 levels following a meal tolerance test; and appetite by ad libitum meal test and visual analogue scales. Both groups lost approximately 5 % of their body weight by week nine (-5.3 ± 0.1 % vs -4.3 ± 0.4 %, p = 0.13, but the inulin group lost significantly more weight between 9 and 18 weeks (-2.3 ± 0.5 % vs -0.6 ± 0.4 %, p = 0.012). Subjects taking inulin had lower hepatic (p = 0.02) and soleus muscle (p fat content at 18 weeks compared to control even after controlling for weight loss and consumed less at the ad libitum meal test (p = 0.027). Fasting glucose significantly decreased at week nine only (p = 0.005), insulin concentrations did not change, and there

  18. Assessing visual control during simulated and live operations: gathering evidence for the content validity of simulation using eye movement metrics.

    Science.gov (United States)

    Vine, Samuel J; McGrath, John S; Bright, Elizabeth; Dutton, Thomas; Clark, James; Wilson, Mark R

    2014-06-01

    Although virtual reality (VR) simulators serve an important role in the training and assessment of surgeons, they need to be evaluated for evidence of validity. Eye-tracking technology and measures of visual control have been used as an adjunct to the performance parameters produced by VR simulators to help in objectively establishing the construct validity (experts vs. novices) of VR simulators. However, determining the extent to which VR simulators represent the real procedure and environment (content validity) has largely been a subjective process undertaken by experienced surgeons. This study aimed to examine the content validity of a VR transurethral resection of the prostate (TURP) simulator by comparing visual control metrics taken during simulated and real TURP procedures. Eye-tracking data were collected from seven surgeons performing 14 simulated TURP operations and three surgeons performing 15 real TURP operations on live patients. The data were analyzed offline, and visual control metrics (number and duration of fixations, percentage of time the surgeons fixated on the screen) were calculated. The surgeons displayed more fixations of a shorter duration and spent less time fixating on the video monitor during the real TURP than during the simulated TURP. This could have been due to (1) the increased complexity of the operating room (OR) environment (2) the decreased quality of the image of the urethra and associated anatomy (compared with the VR simulator), or (3) the impairment of visual attentional control due to the increased levels of stress likely experienced in the OR. The findings suggest that the complexity of the environment surrounding VR simulators needs to be considered in the design of effective simulated training curricula. The study also provides support for the use of eye-tracking technology to assess the content validity of simulation and to examine psychomotor processes during live operations.

  19. Sensorimotor control of gait: A novel approach for the study of the interplay of visual and proprioceptive feedback

    Directory of Open Access Journals (Sweden)

    Ryan eFrost

    2015-02-01

    Full Text Available Sensorimotor control theories propose that the central nervous system exploits expected sensory consequences generated by motor commands for movement planning, as well as online sensory feedback for comparison with expected sensory feedback for monitoring and correcting, if needed, ongoing motor output. In our study, we tested this theoretical framework by quantifying the functional role of expected versus actual proprioceptive feedback for planning and regulation of gait in humans. We addressed this question by using a novel methodological approach to deliver fast perturbations of the walking surface stiffness, in conjunction with a virtual reality system that provided visual feedback of upcoming changes of surface stiffness. In the predictable experimental condition, we asked subjects to learn associating visual feedback of changes in floor stiffness (sand patch during locomotion to quantify kinematic and kinetic changes in gait. In the unpredictable experimental condition, we perturbed floor stiffness at unpredictable instances during the gait to characterize the gait-phase dependent strategies in recovering the locomotor cycle. For the unpredictable conditions, visual feedback of changes in floor stiffness was absent or inconsistent with tactile and proprioceptive feedback. The investigation of these perturbation-induced effects on legs kinematics revealed that visual feedback of upcoming changes in floor stiffness allows for both early (preparatory and late (post-perturbation changes in leg kinematics. However, when proprioceptive feedback is not available, the early responses do not occur while the late responses are preserved although in a, slightly attenuated form. The methods proposed and the preliminary results of this study open new directions for the investigation of the relative role of visual, tactile, and proprioceptive feedback on gait control, with potential implications for designing novel robot-assisted gait rehabilitation

  20. Visual outcome, endocrine function and tumor control after fractionated stereotactic radiation therapy of craniopharyngiomas in adults

    DEFF Research Database (Denmark)

    Astradsson, Arnar; Munck Af Rosenschöld, Per; Feldt-Rasmussen, Ulla

    2017-01-01

    BACKGROUND: The purpose of this study was to examine visual outcome, endocrine function and tumor control in a prospective cohort of craniopharyngioma patients, treated with fractionated stereotactic radiation therapy (FSRT). MATERIAL AND METHODS: Sixteen adult patients with craniopharyngiomas were...... eligible for analysis. They were treated with linear accelerator-based FSRT during 1999-2015. In all cases, diagnosis was confirmed by histological analysis. The prescription dose to the tumor was 54 Gy (median, range 48-54) in 1.8 or 2.0 Gy per fraction, and the maximum radiation dose to the optic nerves.......7-13.1) for visual outcome, endocrine function, and tumor control, respectively. RESULTS: Visual acuity impairment was present in 10 patients (62.5%) and visual field defects were present in 12 patients (75%) before FSRT. One patient developed radiation-induced optic neuropathy at seven years after FSRT. Thirteen...

  1. Design of novel non-contact multimedia controller for disability by using visual stimulus.

    Science.gov (United States)

    Pan, Jeng-Shyang; Lo, Chi-Chun; Tsai, Shang-Ho; Lin, Bor-Shyh

    2015-12-01

    The design of a novel non-contact multimedia controller is proposed in this study. Nowadays, multimedia controllers are generally used by patients and nursing assistants in the hospital. Conventional multimedia controllers usually involve in manual operation or other physical movements. However, it is more difficult for the disabled patients to operate the conventional multimedia controller by themselves; they might totally depend on others. Different from other multimedia controllers, the proposed system provides a novel concept of controlling multimedia via visual stimuli, without manual operation. The disabled patients can easily operate the proposed multimedia system by focusing on the control icons of a visual stimulus device, where a commercial tablet is used as the visual stimulus device. Moreover, a wearable and wireless electroencephalogram (EEG) acquisition device is also designed and implemented to easily monitor the user's EEG signals in daily life. Finally, the proposed system has been validated. The experimental result shows that the proposed system can effectively measure and extract the EEG feature related to visual stimuli, and its information transfer rate is also good. Therefore, the proposed non-contact multimedia controller exactly provides a good prototype of novel multimedia controlling scheme. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. P2PStudio - Monitoring, Controlling and Visualization Tool for Peer-to-Peer Networks Research

    OpenAIRE

    Kotilainen, Niko; Vapa, Mikko; Auvinen, Annemari; Weber, Matthieu; Vuori, Jarkko

    2006-01-01

    Peer-to-Peer Studio has been developed as a monitoring, controlling and visualization tool for peer-to-peer networks. It uses a centralized architecture to gather events from a peer-to-peer network and can be used to visualize network topology and to send different commands to individual peer-to-peer nodes. The tool has been used with Chedar Peer-to-Peer network to study the behavior of different peer-to-peer resource discovery and topology management algorithms and for visualizing the result...

  3. Control Framework for Dexterous Manipulation Using Dynamic Visual Servoing and Tactile Sensors’ Feedback

    Directory of Open Access Journals (Sweden)

    Carlos A. Jara

    2014-01-01

    Full Text Available Tactile sensors play an important role in robotics manipulation to perform dexterous and complex tasks. This paper presents a novel control framework to perform dexterous manipulation with multi-fingered robotic hands using feedback data from tactile and visual sensors. This control framework permits the definition of new visual controllers which allow the path tracking of the object motion taking into account both the dynamics model of the robot hand and the grasping force of the fingertips under a hybrid control scheme. In addition, the proposed general method employs optimal control to obtain the desired behaviour in the joint space of the fingers based on an indicated cost function which determines how the control effort is distributed over the joints of the robotic hand. Finally, authors show experimental verifications on a real robotic manipulation system for some of the controllers derived from the control framework.

  4. Iterative development of visual control systems in a research vivarium.

    Science.gov (United States)

    Bassuk, James A; Washington, Ida M

    2014-01-01

    The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI) methodology, a lean approach to management at Seattle Children's (Hospital, Research Institute, Foundation), would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart's Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and selected Principles

  5. Iterative development of visual control systems in a research vivarium.

    Directory of Open Access Journals (Sweden)

    James A Bassuk

    Full Text Available The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI methodology, a lean approach to management at Seattle Children's (Hospital, Research Institute, Foundation, would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart's Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and

  6. Control Servo-Visual de un Robot Manipulador Planar Basado en Pasividad

    Directory of Open Access Journals (Sweden)

    Carlos Soria

    2008-10-01

    Full Text Available Resumen: En este trabajo se diseña un controlador servo visual basado en la propiedad de pasividad del sistema visual. Se propone un regulador con ganancias de control variables, de tal manera que se evita la saturación de los actuadores y al mismo tiempo presenta la capacidad de corregir errores de pequeña magnitud. Asimismo el diseno se hace tenieñdo en cuenta el desempeño L2, a fin de darle capacidad de seguimiento de objetos en movimiento, con un error de control pequeño. Se muestran resultados experimentales realizados en un robot manipulador industrial tipo planar para verificar el cumplimiento de los objetivos del controlador propuesto. Palabras Clave: robot manipulador industrial, control servo visual, control no lineal, pasividad

  7. Three dimensional visualization to support command and control

    Energy Technology Data Exchange (ETDEWEB)

    Van Slambrook, G.A.

    1997-04-01

    Virtual reality concepts are changing the way one thinks about and with computers. The concepts have already proven their potential usefulness in a broad range of applications. This research was concerned with exploring and demonstrating the utility of virtual reality in robotics and satellite command and control applications. The robotics work addressed the need to quickly build accurate graphical models of physical environments by allowing a user to interactively build a model of a remote environment by superimposing stereo graphics onto live stereo video. The satellite work addressed the fusion of multiple data sets or models into one synergistic display for more effective training, design, and command and control of satellite systems.

  8. Use of a twin dataset to identify AMD-related visual patterns controlled by genetic factors

    Science.gov (United States)

    Quellec, Gwénolé; Abràmoff, Michael D.; Russell, Stephen R.

    2010-03-01

    The mapping of genotype to the phenotype of age-related macular degeneration (AMD) is expected to improve the diagnosis and treatment of the disease in a near future. In this study, we focused on the first step to discover this mapping: we identified visual patterns related to AMD which seem to be controlled by genetic factors, without explicitly relating them to the genes. For this purpose, we used a dataset of eye fundus photographs from 74 twin pairs, either monozygotic twins, who have the same genotype, or dizygotic twins, whose genes responsible for AMD are less likely to be identical. If we are able to differentiate monozygotic twins from dizygotic twins, based on a given visual pattern, then this pattern is likely to be controlled by genetic factors. The main visible consequence of AMD is the apparition of drusen between the retinal pigment epithelium and Bruch's membrane. We developed two automated drusen detectors based on the wavelet transform: a shape-based detector for hard drusen, and a texture- and color- based detector for soft drusen. Forty visual features were evaluated at the location of the automatically detected drusen. These features characterize the texture, the shape, the color, the spatial distribution, or the amount of drusen. A distance measure between twin pairs was defined for each visual feature; a smaller distance should be measured between monozygotic twins for visual features controlled by genetic factors. The predictions of several visual features (75.7% accuracy) are comparable or better than the predictions of human experts.

  9. Collaboration between student art teachers and communication and digital media students promoting subject specific didactics in digital visual learning design

    DEFF Research Database (Denmark)

    Skov, Kirsten; Buhl, Mie

    of learning designs and digital media in visual arts education (Peppler 2010, Rasmussen 2015, Buhl & Ejsing-Duun, 2015; Buhl, 2016). Methodology The choice of empirical design was based on the purpose of involving the future users in developing a visual learning design, and thereby drawing on visual art....... p. 26-40 (14 s.) Buhl, M. (2016) Theory-generating practice. Proposing a principle for learning design. Læring og Medier (LOM), Vol. 9, No. 15, 2016, p. 1-21 Buhl, M. & Ejsing-Duun (2015) Blended learning promoting new developments for Nordic master programs in visual studies and art education, ECEL...... Proceedings, Hatfield Buhl, M. & Flensborg (2011). Visuel kulturpædagogik, København: Hans Reitzels Forlag Peppler, K. (2010). Media arts: Arts education for a digital age. Teachers College Record, vol 112, nr. 8, p. 2118-2153 http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.700.7662&rep=rep1&type=pdf...

  10. Demonstration of visualization techniques for the control room engineer in 2030

    DEFF Research Database (Denmark)

    Marinelli, Mattia; Heussen, Kai; Strasser, Thomas

    2017-01-01

    Deliverable 8.1 reports results on analytics and visualizations of real time flexibility in support of voltage and frequency control in 2030+ power system. The investigation is carried out by means of relevant control room scenarios in order to derive the appropriate analytics needed for each spe...

  11. Effects of visual control training on the shooting performance of elite female basketball players

    NARCIS (Netherlands)

    Oudejans, R.R.D.

    2012-01-01

    In the current study, a method was tested to train visual control in basketball shooting. Using a sender/receiver system, Plato liquid-crystal goggles were wirelessly and manually controlled by the experimenter to manipulate vision of players while they were shooting. During the training the goggles

  12. Altered top-down cognitive control and auditory processing in tinnitus: evidences from auditory and visual spatial stroop.

    Science.gov (United States)

    Araneda, Rodrigo; De Volder, Anne G; Deggouj, Naïma; Philippot, Pierre; Heeren, Alexandre; Lacroix, Emilie; Decat, Monique; Rombaux, Philippe; Renier, Laurent

    2015-01-01

    Tinnitus is the perception of a sound in the absence of external stimulus. Currently, the pathophysiology of tinnitus is not fully understood, but recent studies indicate that alterations in the brain involve non-auditory areas, including the prefrontal cortex. Here, we hypothesize that these brain alterations affect top-down cognitive control mechanisms that play a role in the regulation of sensations, emotions and attention resources. The efficiency of the executive control as well as simple reaction speed and processing speed were evaluated in tinnitus participants (TP) and matched control subjects (CS) in both the auditory and the visual modalities using a spatial Stroop paradigm. TP were slower and less accurate than CS during both the auditory and the visual spatial Stroop tasks, while simple reaction speed and stimulus processing speed were affected in TP in the auditory modality only. Tinnitus is associated both with modality-specific deficits along the auditory processing system and an impairment of cognitive control mechanisms that are involved both in vision and audition (i.e. that are supra-modal). We postulate that this deficit in the top-down cognitive control is a key-factor in the development and maintenance of tinnitus and may also explain some of the cognitive difficulties reported by tinnitus sufferers.

  13. Bias and precision in visual analogue scales: a randomized controlled trial.

    Science.gov (United States)

    Paul-Dauphin, A; Guillemin, F; Virion, J M; Briançon, S

    1999-11-15

    Various types of visual analogue scales (VAS) are used in epidemiologic and clinical research. This paper reports on a randomized controlled trial to investigate the effects of variations in the orientation and type of scale on bias and precision in cross-sectional and longitudinal analyses. This trial was included in the pilot study of the SU.VI.MAX (supplementation by antioxidant vitamins and minerals) prevention trial in France in 1994. Six types of VAS (simple, middle-marked, graphic rating, graduated, graduated-numbered, and numerical rating) and two orientations (horizontal and vertical) were used to measure three symptoms of ear, nose, and throat infection at 2-month intervals in 870 subjects. Differences between scales were analyzed by comparing variances (Levene's test) and means (variance-covariance analysis for repeated measures). Scale characteristics were shown to influence the proportion of zero and low values (i.e., there was a floor effect), but not mean scores. The precision of measurements varied cross-sectionally according to the type of scale, but no differences were observed in the precision of measurement of change over time. In conclusion, the characteristics of VAS seem to be important in cross-sectional studies, particularly when symptoms of low or high intensity are being measured. Researchers should try to reach a consensus on what type of VAS to use if studies are to be compared.

  14. Static and dynamic visual cues in feed-forward postural control

    Science.gov (United States)

    Mohapatra, Sambit

    2012-01-01

    Anticipatory postural adjustments (APAs) play an important role in the performance of many activities requiring the maintenance of vertical posture. However, little is known about how variation in the available visual information affects generation of APAs. The purpose of this study was to investigate the role of different visual cues on APAs. Ten healthy young subjects were exposed to external perturbations induced at the shoulder level in standing while the level of visual information about the forthcoming perturbation was varied. The external perturbations were provided by an aluminum pendulum attached to the ceiling. The visual conditions were (1) dynamic cues (full vision and high-frequency strobe light), (2) static cues (low-frequency strobe light) and (3) no cues (eyes open in dark room). Electrical activity of the trunk and leg muscles and center of pressure displacements were recorded and quantified within the time intervals typical for APAs. The results showed that significantly larger APAs were generated in conditions with dynamic visual cues as compared to the conditions with static cues (p vision and high-frequency strobe light conditions. These findings suggest the importance of using appropriate visual cues in the generation of APAs. PMID:23064846

  15. H∞ Robust Current Control for DFIG Based Wind Turbine subject to Grid Voltage Distortions

    DEFF Research Database (Denmark)

    Wang, Yun; Wu, Qiuwei; Gong, Wenming

    2016-01-01

    This paper proposes an H∞ robust current controller for doubly fed induction generator (DFIG) based wind turbines (WTs) subject to grid voltage distortions. The controller is to mitigate the impact of the grid voltage distortions on rotor currents with DFIG parameter perturbation. The grid voltage...... are designed to efficiently track the unbalanced current components and the 5th and 7th background harmonics. The robust stability (RS) and robust performance (RP) of the proposed controller are verified by the structured singular value µ. The performance of the H∞ robust current controller was demonstrated...

  16. Myofascial trigger points in subjects presenting with mechanical neck pain: a blinded, controlled study.

    Science.gov (United States)

    Fernández-de-las-Peñas, C; Alonso-Blanco, C; Miangolarra, J C

    2007-02-01

    The aim of this study was to describe the differences in the presence of myofascial trigger points (TrPs) in the upper trapezius,sternocleidomastoid, levator scapulae and suboccipital muscles between patients presenting with mechanical neck pain and control healthy subjects. Twenty subjects with mechanical neck pain and 20 matched healthy controls participated in this study. TrPs were identified, by an assessor blinded to the subjects' condition, when there was a hypersensible tender spot in a palpable taut band, local twitch response elicited by the snapping palpation of the taut band, and reproduction of the referred pain typical of each TrP. The mean number of TrPs present on each neck pain patient was 4.3 (SD: 0.9), of which 2.5 (SD: 1.3) were latent and 1.8 (SD: 0.8) were active TrPs. Control subjects also exhibited TrPs (mean: 2; SD: 0.8). All were latent TrPs. Differences in the number of TrPs between both study groups were significant for active TrPs (P latent TrPs (P > 0.5). Moreover, differences in the distribution of TrPs within the analysed cervical muscles were also significant (P Active TrPs were more frequent in patients presenting with mechanical neck pain than in healthy subjects. ©2006 Elsevier Ltd.

  17. Panoramic findings in 34-year-old subjects with facial pain and pain-free controls.

    Science.gov (United States)

    Huumonen, S; Sipilä, K; Zitting, P; Raustia, A M

    2007-06-01

    The aim of this study was to compare panoramic radiographic findings between subjects with reported facial pain and pain-free controls in a population-based sample of 34-year olds. The study was a part of a comprehensive medical survey including subjects born in the year 1966 in Northern Finland. A sub-sample of the cohort was formed based on the question concerning facial pain. A panoramic radiograph was taken of 48 subjects with facial pain and 47 pain-free controls. Pathological findings in the dentition, jaws, maxillary sinuses and temporomandibular joints (TMJs) were compared between the groups. The majority of the subjects in both groups did not have pathological findings. Compared with controls, the subjects with facial pain did not show significantly more pathological findings in the teeth, periodontium, maxillary sinuses, TMJs or in the other areas. Radiographic panoramic findings had no association with reported facial pain in the population-based sample of young adults, and have little impact on the diagnosis of facial pain.

  18. Subject-controlled stimulation of dorsal genital nerve to treat neurogenic detrusor overactivity at home.

    Science.gov (United States)

    Opisso, Eloy; Borau, Albert; Rijkhoff, Nico J M

    2013-09-01

    To investigate the effects of subject controlled dorsal genital nerve (DGN) electrical stimulation on neurogenic detrusor overactivity (NDO) in subjects at home. Subjects underwent a 5-day study at home with DGN stimulation. Stimulation was provided with surface electrodes placed either on the dorsal penile shaft in males and on or close to the clitoris in females. The days 1 and 5 were with no stimulation whereas days 2-4 were with stimulation. Two urodynamic studies were performed at the beginning and at the end of the study. A bladder diary was obtained. Eleven subjects with NDO and with urge incontinence were included. One subject stopped the protocol before the end of the 5-day trial and two did not undergo the second urodynamic study. The subjects showed a statistically significant increase in bladder capacities compared to baseline (P = 0.047). Mean volume per day voided significantly increased over the study within the subjects. Differences between day 1 and day 5 were statistically significant (P = 0.028). The feasibility and the globally positive outcomes of the study indicate that the stimulation of the dorsal genital nerve can be an option for the treatment of the NDO. Copyright © 2012 Wiley Periodicals, Inc.

  19. Visual feedback alters force control and functional activity in the visuomotor network after stroke

    Directory of Open Access Journals (Sweden)

    Derek B. Archer

    2018-01-01

    Full Text Available Modulating visual feedback may be a viable option to improve motor function after stroke, but the neurophysiological basis for this improvement is not clear. Visual gain can be manipulated by increasing or decreasing the spatial amplitude of an error signal. Here, we combined a unilateral visually guided grip force task with functional MRI to understand how changes in the gain of visual feedback alter brain activity in the chronic phase after stroke. Analyses focused on brain activation when force was produced by the most impaired hand of the stroke group as compared to the non-dominant hand of the control group. Our experiment produced three novel results. First, gain-related improvements in force control were associated with an increase in activity in many regions within the visuomotor network in both the stroke and control groups. These regions include the extrastriate visual cortex, inferior parietal lobule, ventral premotor cortex, cerebellum, and supplementary motor area. Second, the stroke group showed gain-related increases in activity in additional regions of lobules VI and VIIb of the ipsilateral cerebellum. Third, relative to the control group, the stroke group showed increased activity in the ipsilateral primary motor cortex, and activity in this region did not vary as a function of visual feedback gain. The visuomotor network, cerebellum, and ipsilateral primary motor cortex have each been targeted in rehabilitation interventions after stroke. Our observations provide new insight into the role these regions play in processing visual gain during a precisely controlled visuomotor task in the chronic phase after stroke.

  20. The research on visual industrial robot which adopts fuzzy PID control algorithm

    Science.gov (United States)

    Feng, Yifei; Lu, Guoping; Yue, Lulin; Jiang, Weifeng; Zhang, Ye

    2017-03-01

    The control system of six degrees of freedom visual industrial robot based on the control mode of multi-axis motion control cards and PC was researched. For the variable, non-linear characteristics of industrial robot`s servo system, adaptive fuzzy PID controller was adopted. It achieved better control effort. In the vision system, a CCD camera was used to acquire signals and send them to video processing card. After processing, PC controls the six joints` motion by motion control cards. By experiment, manipulator can operate with machine tool and vision system to realize the function of grasp, process and verify. It has influence on the manufacturing of the industrial robot.

  1. A component based astronomical visualization tool for instrument control

    Science.gov (United States)

    Briegel, Florian; Berwein, Jürgen; Kittmann, Frank; Pavlov, Alexey

    2008-07-01

    For various astronomical instruments developed at the Max-Planck-Institute-Heidelberg there was a need for a highly flexible display and control tool. Many display tools (ximtool, DS9, skycat,...) are available for astronomy, but all this applications are monolitic and can't be easily enriched by plugins for interaction with the graphical display, and other functionalities for remote access and control of the instrument and data pipepline. It was developed on top of Trolltechs Cross-Platform Rich Client Development Framework Qt,1 the modern middleware Internet Communications Engine 2 from ZeroC and the template based SOA developer framework for astronomical instrumentation - NICE.3 The display tool is used on the Calar Alto Observatory, Spain) as a guider, for a wide field imager and guider at the Wise Observatory (Israel; for the LBT interferometer Linc-Nirvana, USA).

  2. State-Feedback Control for Fractional-Order Nonlinear Systems Subject to Input Saturation

    Directory of Open Access Journals (Sweden)

    Junhai Luo

    2014-01-01

    Full Text Available We give a state-feedback control method for fractional-order nonlinear systems subject to input saturation. First, a sufficient condition is derived for the asymptotical stability of a class of fractional-order nonlinear systems. Then based on Gronwall-Bellman lemma and a sector bounded condition of the saturation function, a linear state-feed back controller is designed. Finally, two simulation examples are presented to show the validity of the proposed method.

  3. Circulating Total Glutathione in Normal Tension Glaucoma Patients: Comparison with Normal Control Subjects

    OpenAIRE

    Park, Myoung Hee; Moon, Jungil

    2012-01-01

    Purpose Oxidative stress plays a critical role in the pathogenesis of glaucoma. Glutathione is a major antioxidant molecule present in intracellular or extracellular space. Herein, we aimed to examine circulating glutathione level in normal tension glaucoma (NTG), which comprises the largest proportion of glaucoma disease in the Korean population. Methods Nineteen NTG patients (NTG group) and 30 age- and gender-matched normal control subjects (control group) were included. Antecubital venous ...

  4. H∞ Robust Current Control for DFIG Based Wind Turbine subject to Grid Voltage Distortions

    OpenAIRE

    Wang, Yun; Wu, Qiuwei; Gong, Wenming; Gryning, Mikkel Peter Sidoroff

    2016-01-01

    This paper proposes an H∞ robust current controller for doubly fed induction generator (DFIG) based wind turbines (WTs) subject to grid voltage distortions. The controller is to mitigate the impact of the grid voltage distortions on rotor currents with DFIG parameter perturbation. The grid voltage distortions considered include asymmetric voltage dips and grid background harmonics. An uncertain DFIG model is developed with uncertain factors originating from distorted stator voltage, and chang...

  5. Lipoic Acid Stimulates cAMP Production in Healthy Control and Secondary Progressive MS Subjects.

    Science.gov (United States)

    Fiedler, Sarah E; Yadav, Vijayshree; Kerns, Amelia R; Tsang, Catherine; Markwardt, Sheila; Kim, Edward; Spain, Rebecca; Bourdette, Dennis; Salinthone, Sonemany

    2017-11-15

    Lipoic acid (LA) exhibits antioxidant and anti-inflammatory properties; supplementation reduces disease severity and T lymphocyte migration into the central nervous system in a murine model of multiple sclerosis (MS), and administration in secondary progressive MS (SPMS) subjects reduces brain atrophy compared to placebo. The mechanism of action (MOA) of LA's efficacy in suppression of MS pathology is incompletely understood. LA stimulates production of the immunomodulator cyclic AMP (cAMP) in vitro. To determine whether cAMP could be involved in the MOA of LA in vivo, we performed a clinical trial to examine whether LA stimulates cAMP production in healthy control and MS subjects, and whether there are differences in the bioavailability of LA between groups. We administered 1200 mg of oral LA to healthy control, relapsing remitting MS (RRMS) and SPMS subjects, and measured plasma LA and cAMP levels in peripheral blood mononuclear cells (PBMCs). There were no significant differences between the groups in pharmacokinetic (PK) parameters. Healthy and SPMS subjects had increased cAMP at 2 and 4 h post-LA treatment compared to baseline, while RRMS subjects showed decreases in cAMP. Additionally, plasma concentrations of prostaglandin E2 (PGE2, a known cAMP stimulator) were significantly lower in female RRMS subjects compared to female HC and SPMS subjects 4 h after LA ingestion. These data indicate that cAMP could be part of the MOA of LA in SPMS, and that there is a divergent response to LA in RRMS subjects that may have implications in the efficacy of immunomodulatory drugs. This clinical trial, "Defining the Anti-inflammatory Role of Lipoic Acid in Multiple Sclerosis," NCT00997438, is registered at https://clinicaltrials.gov/ct2/show/record/NCT00997438 .

  6. Pengaruh Attitude, Subjective Norm, Perceived Behavioral Control Pelanggan Non-muslim terhadap Intention To Purchase

    OpenAIRE

    Andryani, Dwinta; Kurniawati

    2015-01-01

    Penelitian ini dilakukan untuk menganalisa pengaruh Attitude, Subjective Norm, PerceivedBehavioral Control terhadap Intention to Purchase. Data dikumpulkan langsung melaluipenyebaran kuesioner kepada 170 orang responden. Teknik pengambilan sampel dalam penelitianini adalah dengan menggunakan purposive sampling. Hasil empiris dari penelitian inimenggunakan program Statistical Package for the Social Science (SPSS) dengan metode analisisstructural equation model (SEM). Hasil pengujian hipotesis ...

  7. A Framework for Control System Design Subject to Average Data-Rate Constraints

    DEFF Research Database (Denmark)

    Silva, Eduardo; Derpich, Milan; Østergaard, Jan

    2011-01-01

    This paper studies discrete-time control systems subject to average data-rate limits. We focus on a situation where a noisy linear system has been designed assuming transparent feedback and, due to implementation constraints, a source-coding scheme (with unity signal transfer function) has to be ...

  8. Sex differences in objective measures of sleep in post-traumatic stress disorder and healthy control subjects.

    Science.gov (United States)

    Richards, Anne; Metzler, Thomas J; Ruoff, Leslie M; Inslicht, Sabra S; Rao, Madhu; Talbot, Lisa S; Neylan, Thomas C

    2013-12-01

    A growing literature shows prominent sex effects for risk for post-traumatic stress disorder and associated medical comorbid burden. Previous research indicates that post-traumatic stress disorder is associated with reduced slow wave sleep, which may have implications for overall health, and abnormalities in rapid eye movement sleep, which have been implicated in specific post-traumatic stress disorder symptoms, but most research has been conducted in male subjects. We therefore sought to compare objective measures of sleep in male and female post-traumatic stress disorder subjects with age- and sex-matched control subjects. We used a cross-sectional, 2 × 2 design (post-traumatic stress disorder/control × female/male) involving83 medically healthy, non-medicated adults aged 19-39 years in the inpatient sleep laboratory. Visual electroencephalographic analysis demonstrated that post-traumatic stress disorder was associated with lower slow wave sleep duration (F(3,82)  = 7.63, P = 0.007) and slow wave sleep percentage (F(3,82)  = 6.11, P = 0.016). There was also a group × sex interaction effect for rapid eye movement sleep duration (F(3,82)  = 4.08, P = 0.047) and rapid eye movement sleep percentage (F(3,82)  = 4.30, P = 0.041), explained by greater rapid eye movement sleep in post-traumatic stress disorder females compared to control females, a difference not seen in male subjects. Quantitative electroencephalography analysis demonstrated that post-traumatic stress disorder was associated with lower energy in the delta spectrum (F(3,82)  = 6.79, P = 0.011) in non-rapid eye movement sleep. Slow wave sleep and delta findings were more pronounced in males. Removal of post-traumatic stress disorder subjects with comorbid major depressive disorder, who had greater post-traumatic stress disorder severity, strengthened delta effects but reduced rapid eye movement effects to non-significance. These findings support previous evidence that post

  9. Development of visual motion perception for prospective control: Brain and behavioural studies in infants

    Directory of Open Access Journals (Sweden)

    Seth B. Agyei

    2016-02-01

    Full Text Available During infancy, smart perceptual mechanisms develop allowing infants to judge time-space motion dynamics more efficiently with age and locomotor experience. This emerging capacity may be vital to enable preparedness for upcoming events and to be able to navigate in a changing environment. Little is known about brain changes that support the development of prospective control and about processes, such as preterm birth, that may compromise it. As a function of perception of visual motion, this paper will describe behavioural and brain studies with young infants investigating the development of visual perception for prospective control. By means of the three visual motion paradigms of occlusion, looming, and optic flow, our research shows the importance of including behavioural data when studying the neural correlates of prospective control.

  10. The active disturbance rejection control approach to stabilisation of coupled heat and ODE system subject to boundary control matched disturbance

    Science.gov (United States)

    Guo, Bao-Zhu; Liu, Jun-Jun; AL-Fhaid, A. S.; Younas, Arshad Mahmood M.; Asiri, Asim

    2015-08-01

    We consider stabilisation for a linear ordinary differential equation system with input dynamics governed by a heat equation, subject to boundary control matched disturbance. The active disturbance rejection control approach is applied to estimate, in real time, the disturbance with both constant high gain and time-varying high gain. The disturbance is cancelled in the feedback loop. The closed-loop systems with constant high gain and time-varying high gain are shown, respectively, to be practically stable and asymptotically stable.

  11. Who is afraid of the invisible snake? Subjective visual awareness modulates posterior brain activity for evolutionarily threatening stimuli.

    Science.gov (United States)

    Grassini, Simone; Holm, Suvi K; Railo, Henry; Koivisto, Mika

    2016-12-01

    Snakes were probably one of the earliest predators of primates, and snake images produce specific behavioral and electrophysiological reactions in humans. Pictures of snakes evoke enhanced activity over the occipital cortex, indexed by the "early posterior negativity" (EPN), as compared with pictures of other dangerous or non-dangerous animals. The present study investigated the possibility that the response to snake images is independent from visual awareness. The observers watched images of threatening and non-threatening animals presented in random order during rapid serial visual presentation. Four different masking conditions were used to manipulate awareness of the images. Electrophysiological results showed that the EPN was larger for snake images than for the other images employed in the unmasked condition. However, the difference disappeared when awareness of the stimuli decreased. Behavioral results on the effects of awareness did not show any advantage for snake images. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Multi-subject/daily-life activity EMG-based control of mechanical hands

    Directory of Open Access Journals (Sweden)

    Fiorilla Angelo

    2009-11-01

    Full Text Available Abstract Background Forearm surface electromyography (EMG has been in use since the Sixties to feed-forward control active hand prostheses in a more and more refined way. Recent research shows that it can be used to control even a dexterous polyarticulate hand prosthesis such as Touch Bionics's i-LIMB, as well as a multifingered, multi-degree-of-freedom mechanical hand such as the DLR II. In this paper we extend previous work and investigate the robustness of such fine control possibilities, in two ways: firstly, we conduct an analysis on data obtained from 10 healthy subjects, trying to assess the general applicability of the technique; secondly, we compare the baseline controlled condition (arm relaxed and still on a table with a "Daily-Life Activity" (DLA condition in which subjects walk, raise their hands and arms, sit down and stand up, etc., as an experimental proxy of what a patient is supposed to do in real life. We also propose a cross-subject model analysis, i.e., training a model on a subject and testing it on another one. The use of pre-trained models could be useful in shortening the time required by the subject/patient to become proficient in using the hand. Results A standard machine learning technique was able to achieve a real-time grip posture classification rate of about 97% in the baseline condition and 95% in the DLA condition; and an average correlation to the target of about 0.93 (0.90 while reconstructing the required force. Cross-subject analysis is encouraging although not definitive in its present state. Conclusion Performance figures obtained here are in the same order of magnitude of those obtained in previous work about healthy subjects in controlled conditions and/or amputees, which lets us claim that this technique can be used by reasonably any subject, and in DLA situations. Use of previously trained models is not fully assessed here, but more recent work indicates it is a promising way ahead.

  13. The Use of Immersive Visualization for the Control of Dental Anxiety During Oral Debridement.

    Science.gov (United States)

    Padrino-Barrios, Carmelo; McCombs, Gayle; Diawara, Norou; De Leo, Gianluca

    2015-12-01

    The purpose of this study was to evaluate the effects of Immersive Visualization (IV) eyewear on anxious, adult patients during oral debridement. Thirty adult volunteers (n=23 females; n=7 males) were enrolled in the study. Participants were required to be 18 years or older, exhibit at least moderate anxiety (score 9 or higher) on the Corah's Dental Anxiety Scale-Revised (DAS-R), and be generally healthy. Individuals were excluded from participation if they presented with severe dental calculus, periodontal disease, or dental caries, were taking psychotropic drugs, had a history of convulsive disorders, vertigo, or equilibrium disorders, or required antibiotic pre-medication. Subjects received a full mouth oral prophylaxis (supra- and subgingival scaling and selective polishing) by a single experienced dental hygienist. A split mouth design was utilized whereby each subject served as their own control. Subjects were randomly divided into 2 groups: Group A used IV eyewear during the first one-half of the appointment (right side of the mouth) and Group B used IV eyewear during the second one-half of the appointment (left side of the mouth). At screening, medical and dental histories were obtained, full mouth oral examinations were performed, and DAS-R was scored to determine eligibility. At baseline, the DAS-R was re-scored to validate anxiety levels. The Calmness Scale was scored pre- and post-IV treatment on a Likert scale ranging from 1 (very calm) to 7 (less calm). At the end of the study, subjects completed a Post IV Opinion survey. Data were entered into Microsoft Excel for Mac 2011 (Microsoft Corporation Version 14.3.5) and analyzed using SAS® 9.3 statistical software. Thirty subjects with a mean age of 29.9 years completed the study. Data analysis indicated no statistically significant difference between Group A and B with regard to mean DAS-R anxiety levels at baseline (3.15 and 2.40, respectively), with a p-value of 0.07. Data showed a significant

  14. Resveratrol as Add-on Therapy in Subjects With Well-Controlled Type 2 Diabetes: A Randomized Controlled Trial.

    NARCIS (Netherlands)

    Timmers, S.; Ligt, M. de; Phielix, E.; Weijer, T. van de; Hansen, J.; Moonen-Kornips, E.; Schaart, G.; Kunz, I.; Hesselink, M.K.; Schrauwen-Hinderling, V.B.; Schrauwen, P.

    2016-01-01

    OBJECTIVE: To determine whether resveratrol supplementation can improve insulin sensitivity and promote overall metabolic health on top of standard diabetes care. RESEARCH DESIGN AND METHODS: Seventeen subjects with well-controlled type 2 diabetes (T2D) were treated with placebo and 150 mg/day

  15. Learning feedback and feedforward control in a mirror-reversed visual environment.

    Science.gov (United States)

    Kasuga, Shoko; Telgen, Sebastian; Ushiba, Junichi; Nozaki, Daichi; Diedrichsen, Jörn

    2015-10-01

    When we learn a novel task, the motor system needs to acquire both feedforward and feedback control. Currently, little is known about how the learning of these two mechanisms relate to each other. In the present study, we tested whether feedforward and feedback control need to be learned separately, or whether they are learned as common mechanism when a new control policy is acquired. Participants were trained to reach to two lateral and one central target in an environment with mirror (left-right)-reversed visual feedback. One group was allowed to make online movement corrections, whereas the other group only received visual information after the end of the movement. Learning of feedforward control was assessed by measuring the accuracy of the initial movement direction to lateral targets. Feedback control was measured in the responses to sudden visual perturbations of the cursor when reaching to the central target. Although feedforward control improved in both groups, it was significantly better when online corrections were not allowed. In contrast, feedback control only adaptively changed in participants who received online feedback and remained unchanged in the group without online corrections. Our findings suggest that when a new control policy is acquired, feedforward and feedback control are learned separately, and that there may be a trade-off in learning between feedback and feedforward controllers. Copyright © 2015 the American Physiological Society.

  16. Visual Servoing of a Conventional CNC Machine Using an External Axis Controller

    Directory of Open Access Journals (Sweden)

    Daniel Hanafi

    2003-04-01

    Full Text Available This paper presents the implementation of an external axis control system on a conventional CNC machine so that the machine can be actively controlled in response to sensors such as vision and force. The controller that runs on an external computer has direct access to the CNC controller for machine position sensing. The control signals to the machine are sent through purpose built circuitry via the machine's manual pulse generator (MPG inputs. To demonstrate the accuracy and performance of the control system, it was used to visually track the profile of a mandrel used for shear spinning. The implemented system eliminates the parallax error and the need to use an accurate pixel resolution. The raw tracking data is processed by a curvature detection algorithm that detects linear and circular segments and segment transitions. The results show that the visual tracking system provides accurate tracking results that are well within the tolerances used in the industry.

  17. EMG-based visual-haptic biofeedback: a tool to improve motor control in children with primary dystonia.

    Science.gov (United States)

    Casellato, Claudia; Pedrocchi, Alessandra; Zorzi, Giovanna; Vernisse, Lea; Ferrigno, Giancarlo; Nardocci, Nardo

    2013-05-01

    New insights suggest that dystonic motor impairments could also involve a deficit of sensory processing. In this framework, biofeedback, making covert physiological processes more overt, could be useful. The present work proposes an innovative integrated setup which provides the user with an electromyogram (EMG)-based visual-haptic biofeedback during upper limb movements (spiral tracking tasks), to test if augmented sensory feedbacks can induce motor control improvement in patients with primary dystonia. The ad hoc developed real-time control algorithm synchronizes the haptic loop with the EMG reading; the brachioradialis EMG values were used to modify visual and haptic features of the interface: the higher was the EMG level, the higher was the virtual table friction and the background color proportionally moved from green to red. From recordings on dystonic and healthy subjects, statistical results showed that biofeedback has a significant impact, correlated with the local impairment, on the dystonic muscular control. These tests pointed out the effectiveness of biofeedback paradigms in gaining a better specific-muscle voluntary motor control. The flexible tool developed here shows promising prospects of clinical applications and sensorimotor rehabilitation.

  18. Action potential simulation (APS) in patients with fibromyalgia syndrome (FMS): a controlled single subject experimental design.

    Science.gov (United States)

    Fengler, R K B; Jacobs, J W G; Bac, M; van Wijck, A J M; van Meeteren, N L U

    2007-03-01

    Action potential simulation (APS) is becoming a popular method of pain reduction. Nevertheless, little is known about the efficacy of this relatively new treatment. The aim of this study was to investigate whether APS helps to reduce pain, improves patients' perception of daily functioning and social participation in patients with fibromyalgia syndrome (FMS). Ten patients with FMS according to the American College of Rheumatology (ACR) criteria entered this double blind crossover single-case study. In a period of 20 weeks, the patients underwent two treatment periods of 4 weeks, one with verum and one with placebo, at random, in a double blind fashion. Outcome measures were evaluated on a weekly basis. Primary outcome measure was pain measured with the Fibromyalgia Impact Questionnaire (FIQ) questions 4 and 5, the number of tender points and the total tender point pain intensity score. Both visual inspection and statistical analysis were done to analyse the data from this single-subject design. Performing visual inspection and statistical analysis, no positive results of the APS treatment were found in this study. Remarkable is the fact that placebo APS had significantly better results than verum APS. In this single-case study with ten patients (all female), APS was not a helpful method to reduce pain, to improve patients' perception of daily functioning and social participation in patients with FMS.

  19. Proof-of-Concept Demonstration Results for Robotic Visual Servo Controllers

    Energy Technology Data Exchange (ETDEWEB)

    Chawda, P.V.

    2004-09-22

    There is significant motivation to provide robotic systems with improved autonomy as a means to significantly accelerate deactivation and decommissioning operations while also reducing the associated costs, removing human operators from hazardous environments, and reducing the required burden and skill of human operators. To achieve improved autonomy, fundamental research is focused on the challenges of developing visual servo controllers. The challenge in developing these controllers is that a camera provides 2-dimensional image information about the 3-dimensional Euclidean-space through a perspective (range dependent) projection that can be corrupted by uncertainty in the camera calibration matrix. Disturbances in this relationship (i.e., corruption in the sensor information) propagate erroneous information to the feedback controller of the robot, leading to potentially unpredictable task execution. This technical manual describes 3 proof-of-concept demonstrations of visual servo controllers developed from fundamental research aimed at these challenges. Specifically, one section describes the implementation of a cooperative visual servo control scheme with a camera-in-hand and a fixed camera to track a moving target despite uncertainty in the camera calibration and the unknown constant distance from the camera to a target where the camera is mounted on the end-effector of a 6 degrees-of-freedom hydraulic robot manipulator. The next section describes the implementation of 2 homography-based visual servo tracking and regulation controllers for a mobile robot with a calibrated camera despite an unknown time-varying distance from the camera to a target.

  20. The Next Generation of Ground Operations Command and Control; Scripting in C Sharp and Visual Basic

    Science.gov (United States)

    Ritter, George; Pedoto, Ramon

    2010-01-01

    This slide presentation reviews the use of scripting languages in Ground Operations Command and Control. It describes the use of scripting languages in a historical context, the advantages and disadvantages of scripts. It describes the Enhanced and Redesigned Scripting (ERS) language, that was designed to combine the features of a scripting language and the graphical and IDE richness of a programming language with the utility of scripting languages. ERS uses the Microsoft Visual Studio programming environment and offers custom controls that enable an ERS developer to extend the Visual Basic and C sharp language interface with the Payload Operations Integration Center (POIC) telemetry and command system.

  1. Top-Down Control of Visual Alpha Oscillations: Sources of Control Signals and Their Mechanisms of Action.

    Science.gov (United States)

    Wang, Chao; Rajagovindan, Rajasimhan; Han, Sahng-Min; Ding, Mingzhou

    2016-01-01

    Alpha oscillations (8-12 Hz) are thought to inversely correlate with cortical excitability. Goal-oriented modulation of alpha has been studied extensively. In visual spatial attention, alpha over the region of visual cortex corresponding to the attended location decreases, signifying increased excitability to facilitate the processing of impending stimuli. In contrast, in retention of verbal working memory, alpha over visual cortex increases, signifying decreased excitability to gate out stimulus input to protect the information held online from sensory interference. According to the prevailing model, this goal-oriented biasing of sensory cortex is effected by top-down control signals from frontal and parietal cortices. The present study tests and substantiates this hypothesis by (a) identifying the signals that mediate the top-down biasing influence, (b) examining whether the cortical areas issuing these signals are task-specific or task-independent, and (c) establishing the possible mechanism of the biasing action. High-density human EEG data were recorded in two experimental paradigms: a trial-by-trial cued visual spatial attention task and a modified Sternberg working memory task. Applying Granger causality to both sensor-level and source-level data we report the following findings. In covert visual spatial attention, the regions exerting top-down control over visual activity are lateralized to the right hemisphere, with the dipoles located at the right frontal eye field (FEF) and the right inferior frontal gyrus (IFG) being the main sources of top-down influences. During retention of verbal working memory, the regions exerting top-down control over visual activity are lateralized to the left hemisphere, with the dipoles located at the left middle frontal gyrus (MFG) being the main source of top-down influences. In both experiments, top-down influences are mediated by alpha oscillations, and the biasing effect is likely achieved via an inhibition

  2. Top-down Control of Visual Alpha Oscillations: Sources of Control Signals and Their Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Chao eWang

    2016-01-01

    Full Text Available Alpha oscillations (8 to 12 Hz are thought to inversely correlate with cortical excitability. Goal-oriented modulation of alpha has been studied extensively. In visual spatial attention, alpha over the region of visual cortex corresponding to the attended location decreases, signifying increased excitability to facilitate the processing of impending stimuli. In contrast, in retention of verbal working memory, alpha over visual cortex increases, signifying decreased excitability to gate out stimulus input to protect the information held online from sensory interference. According to the prevailing model, this goal-oriented biasing of sensory cortex is effected by top-down control signals from frontal and parietal cortices. The present study tests and substantiates this hypothesis by (a identifying the signals that mediate the top-down biasing influence, (b examining whether the cortical areas issuing these signals are task-specific or task-independent, and (c establishing the possible mechanism of the biasing action. High-density human EEG data were recorded in two experimental paradigms: a trial-by-trial cued visual spatial attention task and a modified Sternberg working memory task. Applying Granger causality to both sensor-level and source-level data we report the following findings. In covert visual spatial attention, the regions exerting top-down control over visual activity are lateralized to the right hemisphere, with the dipoles located at the right frontal eye field (FEF and the right inferior frontal gyrus (IFG being the main sources of top-down influences. During retention of verbal working memory, the regions exerting top-down control over visual activity are lateralized to the left hemisphere, with the dipoles located at the left middle frontal gyrus (MFG being the main source of top-down influences. In both experiments, top-down influences are mediated by alpha oscillations, and the biasing effect is likely achieved via an

  3. Different Serum Free Fatty Acid Profiles in NAFLD Subjects and Healthy Controls after Oral Fat Load

    Directory of Open Access Journals (Sweden)

    Roberto Gambino

    2016-03-01

    Full Text Available Background: Free fatty acid (FFA metabolism can impact on metabolic conditions, such as obesity and nonalcoholic fatty liver disease (NAFLD. This work studied the increase in total FFA shown in NAFLD subjects to possibly characterize which fatty acids significantly accounted for the whole increase. Methods: 21 patients with NAFLD were selected according to specified criteria. The control group consisted of nine healthy subjects. All subjects underwent an oral standard fat load. Triglycerides; cholesterol; FFA; glucose and insulin were measured every 2 h with the determination of fatty acid composition of FFA. Results: higher serum FFA levels in NAFLD subjects are mainly due to levels of oleic, palmitic and linoleic acids at different times. Significant increases were shown for docosahexaenoic acid, linolenic acid, eicosatrienoic acid, and arachidonic acid, although this was just on one occasion. In the postprandial phase, homeostatic model assessment HOMA index positively correlated with the ω3/ω6 ratio in NAFLD patients. Conclusions: the higher serum levels of FFA in NAFLD subjects are mainly due to levels of oleic and palmitic acids which are the most abundant circulating free fatty acids. This is almost exactly corresponded with significant increases in linoleic acid. An imbalance in the n-3/n-6 fatty acids ratio could modulate postprandial responses with more pronounced effects in insulin-resistant subjects, such as NAFLD patients.

  4. Real-Time Inverse Optimal Neural Control for Image Based Visual Servoing with Nonholonomic Mobile Robots

    Directory of Open Access Journals (Sweden)

    Carlos López-Franco

    2015-01-01

    Full Text Available We present an inverse optimal neural controller for a nonholonomic mobile robot with parameter uncertainties and unknown external disturbances. The neural controller is based on a discrete-time recurrent high order neural network (RHONN trained with an extended Kalman filter. The reference velocities for the neural controller are obtained with a visual sensor. The effectiveness of the proposed approach is tested by simulations and real-time experiments.

  5. LMI-Based Fuzzy Optimal Variance Control of Airfoil Model Subject to Input Constraints

    Science.gov (United States)

    Swei, Sean S.M.; Ayoubi, Mohammad A.

    2017-01-01

    This paper presents a study of fuzzy optimal variance control problem for dynamical systems subject to actuator amplitude and rate constraints. Using Takagi-Sugeno fuzzy modeling and dynamic Parallel Distributed Compensation technique, the stability and the constraints can be cast as a multi-objective optimization problem in the form of Linear Matrix Inequalities. By utilizing the formulations and solutions for the input and output variance constraint problems, we develop a fuzzy full-state feedback controller. The stability and performance of the proposed controller is demonstrated through its application to the airfoil flutter suppression.

  6. Visual control in basketball shooting under exertion conditions.

    Science.gov (United States)

    Zwierko, Teresa; Popowczak, Marek; Woźniak, Jarosław; Rokita, Andrzej

    2017-07-25

    This study examined the effect of physical exertion on gaze behavior during basketball shooting in both stationary and dynamic conditions. Thirteen skilled basketball players performed two-point shooting during a 60 second fatigue protocol. Before and after a jump shot test, players performed two free throws. Eye movements were registered using an SMI Mobile EyeTracker. The frequency of all fixation points (number) and fixation duration during the motor phases of shooting were determined using frame-by- frame analysis. The type of basketball shot differentiated gaze control: (1) fixations were longer and more frequent during free throws as compared to jump shots, (2) shooting accuracy was positively influenced by less frequent and longer fixations, (3) physical exertion resulted in significantly more frequent fixations during free throws, and (4) exertion conditions resulted in a high variation in the patterns of total fixation times during jump shots. The findings suggest that physical exertion may reduce oculomotor efficiency during aiming at a distant target. Moreover, stationary and dynamic shots require different gaze behavior strategies.

  7. Relationship between reaction time, fine motor control, and visual-spatial perception on vigilance and visual-motor tasks in 22q11.2 Deletion Syndrome.

    LENUS (Irish Health Repository)

    Howley, Sarah A

    2012-10-15

    22q11.2 Deletion Syndrome (22q11DS) is a common microdeletion disorder associated with mild to moderate intellectual disability and specific neurocognitive deficits, particularly in visual-motor and attentional abilities. Currently there is evidence that the visual-motor profile of 22q11DS is not entirely mediated by intellectual disability and that these individuals have specific deficits in visual-motor integration. However, the extent to which attentional deficits, such as vigilance, influence impairments on visual motor tasks in 22q11DS is unclear. This study examines visual-motor abilities and reaction time using a range of standardised tests in 35 children with 22q11DS, 26 age-matched typically developing (TD) sibling controls and 17 low-IQ community controls. Statistically significant deficits were observed in the 22q11DS group compared to both low-IQ and TD control groups on a timed fine motor control and accuracy task. The 22q11DS group performed significantly better than the low-IQ control group on an untimed drawing task and were equivalent to the TD control group on point accuracy and simple reaction time tests. Results suggest that visual motor deficits in 22q11DS are primarily attributable to deficits in psychomotor speed which becomes apparent when tasks are timed versus untimed. Moreover, the integration of visual and motor information may be intact and, indeed, represent a relative strength in 22q11DS when there are no time constraints imposed. While this may have significant implications for cognitive remediation strategies for children with 22q11DS, the relationship between reaction time, visual reasoning, cognitive complexity, fine motor speed and accuracy, and graphomotor ability on visual-motor tasks is still unclear.

  8. Working memory load and distraction: dissociable effects of visual maintenance and cognitive control.

    Science.gov (United States)

    Konstantinou, Nikos; Beal, Eleanor; King, Jean-Remi; Lavie, Nilli

    2014-10-01

    We establish a new dissociation between the roles of working memory (WM) cognitive control and visual maintenance in selective attention as measured by the efficiency of distractor rejection. The extent to which focused selective attention can prevent distraction has been shown to critically depend on the level and type of load involved in the task. High perceptual load that consumes perceptual capacity leads to reduced distractor processing, whereas high WM load that reduces WM ability to exert priority-based executive cognitive control over the task results in increased distractor processing (e.g., Lavie, Trends in Cognitive Sciences, 9(2), 75-82, 2005). WM also serves to maintain task-relevant visual representations, and such visual maintenance is known to recruit the same sensory cortices as those involved in perception (e.g., Pasternak & Greenlee, Nature Reviews Neuroscience, 6(2), 97-107, 2005). These findings led us to hypothesize that loading WM with visual maintenance would reduce visual capacity involved in perception, thus resulting in reduced distractor processing-similar to perceptual load and opposite to WM cognitive control load. Distractor processing was assessed in a response competition task, presented during the memory interval (or during encoding; Experiment 1a) of a WM task. Loading visual maintenance or encoding by increased set size for a memory sample of shapes, colors, and locations led to reduced distractor response competition effects. In contrast, loading WM cognitive control with verbal rehearsal of a random letter set led to increased distractor effects. These findings confirm load theory predictions and provide a novel functional distinction between the roles of WM maintenance and cognitive control in selective attention.

  9. Visually guided reaching: bilateral posterior parietal lesions cause a switch from fast visuomotor to slow cognitive control.

    Science.gov (United States)

    Rossetti, Y; Revol, P; McIntosh, R; Pisella, L; Rode, G; Danckert, J; Tilikete, C; Dijkerman, H C; Boisson, D; Vighetto, A; Michel, F; Milner, A D

    2005-01-01

    The visually guided reaching of two patients with bilateral optic ataxia was explored in two experiments. In Experiment 1 simple delayed pointing was compared with immediate pointing. In the immediate pointing task both variable and constant errors increased with target eccentricity. In contrast to the performance of control subjects and contrary to their own beliefs, the patients both showed improved accuracy in the delay condition. This improvement was manifest as a reduction in both pointing variability and in the constant angular error towards the point of fixation. Both angular errors and their improvement with the delay were proportional to target eccentricity. Experiment 2 used a task in which the target was pre-viewed 5s prior to its re-exposure for pointing ('delayed real pointing'). On some trials a conflict was introduced between the present and previous visual information by changing the target's location during the delay. In contrast to control subjects, who ignored the pre-viewed location and aimed directly at the current target, both patients with optic ataxia initiated their movements towards the previously viewed target location. Evidently they relied on off-line information in preference to on-line visual information. In addition, the patients often failed to detect the changes in target location. One of the patients sometimes even guessed incorrectly that the target had changed its location, and her movement trajectory was then more affected by her false belief than by the target's actual location. These findings confirm that posterior parietal lesions severely disrupt direct visuomotor transformations, and suggest that the residual performance is mediated indirectly by expectations or beliefs about target position.

  10. Control of a visual keyboard using an electrocorticographic brain-computer interface.

    Science.gov (United States)

    Krusienski, Dean J; Shih, Jerry J

    2011-05-01

    Brain-computer interfaces (BCIs) are devices that enable severely disabled people to communicate and interact with their environments using their brain waves. Most studies investigating BCI in humans have used scalp EEG as the source of electrical signals and focused on motor control of prostheses or computer cursors on a screen. The authors hypothesize that the use of brain signals obtained directly from the cortical surface will more effectively control a communication/spelling task compared to scalp EEG. A total of 6 patients with medically intractable epilepsy were tested for the ability to control a visual keyboard using electrocorticographic (ECOG) signals. ECOG data collected during a P300 visual task paradigm were preprocessed and used to train a linear classifier to subsequently predict the intended target letters. The classifier was able to predict the intended target character at or near 100% accuracy using fewer than 15 stimulation sequences in 5 of the 6 people tested. ECOG data from electrodes outside the language cortex contributed to the classifier and enabled participants to write words on a visual keyboard. This is a novel finding because previous invasive BCI research in humans used signals exclusively from the motor cortex to control a computer cursor or prosthetic device. These results demonstrate that ECOG signals from electrodes both overlying and outside the language cortex can reliably control a visual keyboard to generate language output without voice or limb movements.

  11. Postural Control in Bilateral Vestibular Failure: Its Relation to Visual, Proprioceptive, Vestibular, and Cognitive Input.

    Science.gov (United States)

    Sprenger, Andreas; Wojak, Jann F; Jandl, Nico M; Helmchen, Christoph

    2017-01-01

    Patients with bilateral vestibular failure (BVF) suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC), visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance. Between-group analysis revealed larger postural sway in BVF patients on eye closure; but with the eyes open, BVF did not differ from healthy controls (HCs). Head tilts and horizontal head shaking increased sway but did not differ between groups. In the dual task condition, BVF patients maintained posture indistinguishable from controls. On foam and tandem stance, postural sway was larger in BVF, even with the eyes open. The best predictor for the severity of bilateral vestibulopathy was standing on foam with eyes closed. Postural control of our BVF was indistinguishable from HCs once visual and proprioceptive feedback is provided. This distinguishes them from patients with vestibulo-cerebellar disorders or functional dizziness. It confirms previous reports and explains that postural unsteadiness of BVF patients can be missed easily if not examined by conditions of visual and/or proprioceptive deprivation. In fact, the best predictor for vestibular hypofunction (VOR gain) was examining patients standing on foam with the eyes closed. Postural sway in that condition increased with the severity of vestibular impairment but not with disease duration. In the absence of visual control, impaired otolith input destabilizes BVF with head retroflexion. Stimulating deficient SSC does not distinguish patients from controls possibly reflecting a shift of intersensory weighing toward proprioceptive-guided postural control. Accordingly, proprioceptive

  12. Postural Control in Bilateral Vestibular Failure: Its Relation to Visual, Proprioceptive, Vestibular, and Cognitive Input

    Science.gov (United States)

    Sprenger, Andreas; Wojak, Jann F.; Jandl, Nico M.; Helmchen, Christoph

    2017-01-01

    Patients with bilateral vestibular failure (BVF) suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC), visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance. Between-group analysis revealed larger postural sway in BVF patients on eye closure; but with the eyes open, BVF did not differ from healthy controls (HCs). Head tilts and horizontal head shaking increased sway but did not differ between groups. In the dual task condition, BVF patients maintained posture indistinguishable from controls. On foam and tandem stance, postural sway was larger in BVF, even with the eyes open. The best predictor for the severity of bilateral vestibulopathy was standing on foam with eyes closed. Postural control of our BVF was indistinguishable from HCs once visual and proprioceptive feedback is provided. This distinguishes them from patients with vestibulo-cerebellar disorders or functional dizziness. It confirms previous reports and explains that postural unsteadiness of BVF patients can be missed easily if not examined by conditions of visual and/or proprioceptive deprivation. In fact, the best predictor for vestibular hypofunction (VOR gain) was examining patients standing on foam with the eyes closed. Postural sway in that condition increased with the severity of vestibular impairment but not with disease duration. In the absence of visual control, impaired otolith input destabilizes BVF with head retroflexion. Stimulating deficient SSC does not distinguish patients from controls possibly reflecting a shift of intersensory weighing toward proprioceptive-guided postural control. Accordingly, proprioceptive

  13. Radiation field control at the latest BWR plants -- design principle, operational experience and future subjects

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Shunsuke [Energy Research Lab., Ibaraki (Japan); Ohsumi, Katsumi; Takashima, Yoshie [Hitachi Works, Ibaraki (Japan)

    1995-03-01

    Improvements of operational procedures to control water chemistry, e.g., nickel/iron control, as well as application of hardware improvements for reducing radioactive corrosion products resulted in an extremely low occupational exposure of less than 0.5 man.Sv/yr without any serious impact on the radwaste system, for BWR plants involved in the Japanese Improvement and Standardization Program. Recently, {sup 60}C radioactively in the reactor water has been increasing due to less crud fixation on the two smooth surfaces of new type high performance fuels and to the pH drop caused by chromium oxide anions released from stainless steel structures and pipings. This increase must be limited by changes in water chemistry, e.g., applications of modified nickel/iron ratio control and weak alkali control. Controlled water chemistry to optimize three points, the plant radiation level and integrities of fuel and structural materials, is the primary future subject for BWR water chemistry.

  14. The influence of motivational and mood states on visual attention: A quantification of systematic differences and casual changes in subjects' focus of attention.

    Science.gov (United States)

    Hüttermann, Stefanie; Memmert, Daniel

    2015-01-01

    A great number of studies have shown that different motivational and mood states can influence human attentional processes in a variety of ways. Yet, none of these studies have reliably quantified the exact changes of the attentional focus in order to be able to compare attentional performances based on different motivational and mood influences and, beyond that, to evaluate their effectivity. In two studies, we explored subjects' differences in the breadth and distribution of attention as a function of motivational and mood manipulations. In Study 1, motivational orientation was classified in terms of regulatory focus (promotion vs. prevention) and in Study 2, mood was classified in terms of valence (positive vs. negative). Study 1 found a 10% wider distribution of the visual attention in promotion-oriented subjects compared to prevention-oriented ones. The results in Study 2 reveal a widening of the subjects' visual attentional breadth when listening to happy music by 22% and a narrowing by 36% when listening to melancholic music. In total, the findings show that systematic differences and casual changes in the shape and scope of focused attention may be associated with different motivational and mood states.

  15. A New Architecture for Visualization: Open Mission Control Technologies

    Science.gov (United States)

    Trimble, Jay

    2017-01-01

    Open Mission Control Technologies (MCT) is a new architecture for visualisation of mission data. Driven by requirements for new mission capabilities, including distributed mission operations, access to data anywhere, customization by users, synthesis of multiple data sources, and flexibility for multi-mission adaptation, Open MCT provides users with an integrated customizable environment. Developed at NASAs Ames Research Center (ARC), in collaboration with NASAs Advanced Multimission Operations System (AMMOS) and NASAs Jet Propulsion Laboratory (JPL), Open MCT is getting its first mission use on the Jason 3 Mission, and is also available in the testbed for the Mars 2020 Rover and for development use for NASAs Resource Prospector Lunar Rover. The open source nature of the project provides for use outside of space missions, including open source contributions from a community of users. The defining features of Open MCT for mission users are data integration, end user composition and multiple views. Data integration provides access to mission data across domains in one place, making data such as activities, timelines, telemetry, imagery, event timers and procedures available in one place, without application switching. End user composition provides users with layouts, which act as a canvas to assemble visualisations. Multiple views provide the capability to view the same data in different ways, with live switching of data views in place. Open MCT is browser based, and works on the desktop as well as tablets and phones, providing access to data anywhere. An early use case for mobile data access took place on the Resource Prospector (RP) Mission Distributed Operations Test, in which rover engineers in the field were able to view telemetry on their phones. We envision this capability providing decision support to on console operators from off duty personnel. The plug-in architecture also allows for adaptation for different mission capabilities. Different data types and

  16. Contrasting Complement Control, Temporal Adjunct Control and Controlled Verbal Gerund Subjects in ASD: The Role of Contextual Cues in Reference Assignment

    OpenAIRE

    Janke, Vikki; Perovic, Alexandra

    2017-01-01

    This study examines two complex syntactic dependencies (complement control and sentence-final temporal adjunct control) and one pragmatic dependency (controlled verbal gerund subjects) in children with ASD. Sixteen high-functioning (HFA) children (aged 6 to 16) with a diagnosis of autism and no language impairment, matched on age, gender and non-verbal MA to one TD control group, and on age, gender and verbal MA to another TD control group, undertook three picture-selection tasks. Task 1 meas...

  17. Contrasting complement control, temporal adjunct control and controlled verbal gerund subjects in ASD: The role of contextual cues in reference assignment

    OpenAIRE

    Janke, V.; Perovic, A.

    2017-01-01

    This study examines two complex syntactic dependencies (complement control and sentence-final temporal adjunct control) and one pragmatic dependency (controlled verbal gerund subjects) in children with ASD. Sixteen high-functioning (HFA) children (aged 6–16) with a diagnosis of autism and no language impairment, matched on age, gender and non-verbal MA to one TD control group, and on age, gender and verbal MA to another TD control group, undertook three picture-selection tasks....

  18. Cardiovascular effects of aerobic exercise training in formerly preeclamptic women and healthy parous control subjects.

    Science.gov (United States)

    Scholten, Ralph R; Thijssen, Dick J H; Lotgering, Fred K; Hopman, Maria T E; Spaanderman, Marc E A

    2014-11-01

    Women who have had preeclampsia demonstrate higher prevalence of metabolic syndrome (MetS), impaired vascular function, and increased sympathetic activity and are at increased risk of cardiovascular disease. The aim of this study was to assess the effects of 12 weeks of exercise training (70-80% maximum volume of oxygen utilization) in women who had had preeclampsia on physical fitness, components of MetS, vasculature, and autonomic functions compared with healthy control subjects. Our prospective case-control study included 24 normotensive women who had had preeclampsia and 20 control subjects who were matched for age and postpartum interval (all 6-12 months after delivery). Before and after training, we measured all components of MetS (ie, BP, lipids, glucose/insulin, and albuminuria), carotid intima media thickness (IMT) and brachial and superficial femoral artery endothelial function that used flow-mediated dilation (FMD). Autonomic activity was quantified with power spectral analysis (low-frequency/high-frequency power [LF/HF] ratio). At baseline, women who had had preeclampsia demonstrated higher values of most components of MetS. Compared with the control subjects, women who had had preeclampsia had increased IMT (580 ± 92 μm vs 477 ± 65 μm, respectively), impaired endothelial function (FMD brachial artery, 5.3% ± 2.2% vs 10.8% ± 3.5%, respectively; FMD superficial femoral artery, 4.9% ± 2.1% vs 8.7% ± 3.2%, respectively) and increased LF/HF power ratio (2.2 ± 1.0 vs 1.3 ± 0.4, respectively; all P exercise training decreased values of most components of MetS and IMT, improved FMD, and concurrently reduced LF/HF. Despite these improvements, vascular and autonomic variables did not normalize by 12 weeks of training in women who had had preeclampsia. This study demonstrates that exercise training in women who had had preeclampsia and control subjects improves components of MetS, endothelial function, vascular wall thickness, and autonomic control

  19. Subjective and Physiological Responses to Music Stimuli Controlled Over Activity and Preference.

    Science.gov (United States)

    Iwanaga; Moroki

    1999-01-01

    Results of physiological responses to music are inconclusive considering results of several studies, probably due to the insufficient control of the musical stimuli. The present study aimed to examine the effects of music type and preference on subjective and physiological responses using controlled stimuli by subjects' evaluations for music activity and preference. Subjects were 47 undergraduate students selected from a pool of 145 undergraduates. Results of evaluations of music activity and music preference for musical stimuli in preliminary research determined participation in the study. The music used in this study included the 4th movement of Tchaikovsky's Symphony No. 4 as an excitative piece and the 3rd movement of Mahler's Symphony No. 6 as a sedative one. The excitative music aroused feelings of vigor and tension more than did the sedative one, while sedative music eased tension. Favorite music, regardless of music type, lowered subjective tension. Physiological responses (heart rate, respiration, and blood pressure) were greater during excitative music than during sedative music. Music preference did not, however, affect physiological responses. These results indicate that the dominant factor affecting emotional response was music type but not preference.

  20. Evaluation of Subjective and Objective Performance Metrics for Haptically Controlled Robotic Systems

    Directory of Open Access Journals (Sweden)

    Cong Dung Pham

    2014-07-01

    Full Text Available This paper studies in detail how different evaluation methods perform when it comes to describing the performance of haptically controlled mobile manipulators. Particularly, we investigate how well subjective metrics perform compared to objective metrics. To find the best metrics to describe the performance of a control scheme is challenging when human operators are involved; how the user perceives the performance of the controller does not necessarily correspond to the directly measurable metrics normally used in controller evaluation. It is therefore important to study whether there is any correspondence between how the user perceives the performance of a controller, and how it performs in terms of directly measurable metrics such as the time used to perform a task, number of errors, accuracy, and so on. To perform these tests we choose a system that consists of a mobile manipulator that is controlled by an operator through a haptic device. This is a good system for studying different performance metrics as the performance can be determined by subjective metrics based on feedback from the users, and also as objective and directly measurable metrics. The system consists of a robotic arm which provides for interaction and manipulation, which is mounted on a mobile base which extends the workspace of the arm. The operator thus needs to perform both interaction and locomotion using a single haptic device. While the position of the on-board camera is determined by the base motion, the principal control objective is the motion of the manipulator arm. This calls for intelligent control allocation between the base and the manipulator arm in order to obtain intuitive control of both the camera and the arm. We implement three different approaches to the control allocation problem, i.e., whether the vehicle or manipulator arm actuation is applied to generate the desired motion. The performance of the different control schemes is evaluated, and our

  1. A Comparative Analysis of the Colour Subject between Canada Saskatchewan State and Visual Arts Education Curriculum in Turkey

    Science.gov (United States)

    Dabancal, Meral Per

    2015-01-01

    A deeper analysis of the art education curriculums applied in developed countries and treating specific subjects within these curriculums holds vital importance in allowing the production of alternative solution methods by providing the educators multiple perspectives in the face of problems concerning art education. In present paper colour…

  2. A controlled laboratory comparison of 4 topical skin creams moisturizing capability on human subjects.

    Science.gov (United States)

    Young, Daniel L; Chakravarthy, Debashish

    2014-01-01

    This study compares human skin capacitance (moisture) readings after the application of 4 different, commercially available, topical skin creams. Twenty-one subjects (15 women and 6 men) aged 49.38 ± 11.02) years (mean ± SD) participated. This study was conducted in a climate-controlled laboratory on healthy human subjects. Randomized experimental study comparing 4 topical skin creams for their effect on human skin capacitance (moisture). Subject forearm skin was conditioned for 7 days prior to testing by washing with a standard soap and application of no other products. Each subject was marked with 5 test sites on the forearms. Sites on the volar surface of each subject's forearms were randomly assigned for application of 1 of 4 product pairs, consisting of a cleanser and a topical skin cream or a control site. A Corneometer was used to measure skin capacitance. Each site on the arms was cleaned and dried, tested again for moisture content, subjected to topical skin cream application, and finally tested again for moisture content. Changes were measured by subtracting the capacitance readings at baseline from values measured following topical skin cream application for each test site. The mean change in capacitance was 13.9 for product 1, 10.3 for product 3, 8.7 for product 2, 1.6 for product 4, and 0.8 for the control site. The mean capacitance change in sites treated with product 1 (13.9 ± 8.0, mean ± SD) was significantly greater than all others. There was no difference between the change in capacitance of product 2 (mean = 8.7, SD = 4.9) and product 3 (10.3 ± 7.1) t(20) = 1.081, P = .293, nor between product 4 (1.6 ± 3.9) and the control site (0.3, ± 2.2) t(20) = 0.779, P = .445. The capacitance change of products 2 and 3 was greater than that of product 4 and the control site. Commercially available topical skin creams vary in their impact on human skin capacitance. In this study, sites tested with product 1 had a greater skin capacitance reading than

  3. Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station

    Science.gov (United States)

    Bendrick, Gregg A.; Kamine, Tovy Haber

    2008-01-01

    Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. "cones") of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement" (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Methods: Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. Results: The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of "Maximum Eye Movement". However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of "Easy Eye Movement", though all were within the cone of "Maximum Eye Movement". All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Discussion: Most instrument displays in conventional aircraft lay within the cone of "Easy Eye Movement", though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight.

  4. Circadian plasticity in photoreceptor cells controls visual coding efficiency in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Martin Barth

    Full Text Available In the fly Drosophila melanogaster, neuronal plasticity of synaptic terminals in the first optic neuropil, or lamina, depends on early visual experience within a critical period after eclosion. The current study revealed two additional and parallel mechanisms involved in this type of synaptic terminal plasticity. First, an endogenous circadian rhythm causes daily oscillations in the volume of photoreceptor cell terminals. Second, daily visual experience precisely modulates the circadian time course and amplitude of the volume oscillations that the photoreceptor-cell terminals undergo. Both mechanisms are separable in their molecular basis. We suggest that the described neuronal plasticity in Drosophila ensures continuous optimal performance of the visual system over the course of a 24 h-day. Moreover, the sensory system of Drosophila cannot only account for predictable, but also for acute, environmental changes. The volumetric changes in the synaptic terminals of photoreceptor cells are accompanied by circadian and light-induced changes of presynaptic ribbons as well as extensions of epithelial glial cells into the photoreceptor terminals, suggesting that the architecture of the lamina is altered by both visual exposure and the circadian clock. Clock-mutant analysis and the rescue of PER protein rhythmicity exclusively in all R1-6 cells revealed that photoreceptor-cell plasticity is autonomous and sufficient to control visual behavior. The strength of a visually guided behavior, the optomotor turning response, co-varies with synaptic-terminal volume oscillations of photoreceptor cells when elicited at low light levels. Our results show that behaviorally relevant adaptive processing of visual information is performed, in part, at the level of visual input level.

  5. Visual dependence and BPPV.

    Science.gov (United States)

    Agarwal, K; Bronstein, A M; Faldon, M E; Mandalà, M; Murray, K; Silove, Y

    2012-06-01

    The increased visual dependence noted in some vestibular patients may be secondary to their vertigo. We examine whether a single, brief vertigo attack, such as in benign paroxysmal positional vertigo (BPPV), modifies visual dependency. Visual dependency was measured before and after the Hallpike manoeuvre with (a) the Rod and Frame and the Rod and Disc techniques whilst seated and (b) the postural sway induced by visual roll-motion stimulation. Three subject groups were studied: 20 patients with BPPV (history and positive Hallpike manoeuvre; PosH group), 20 control patients (history of BPPV but negative Hallpike manoeuvre; NegH group) and 20 normal controls. Our findings show that while both patient groups showed enhanced visual dependency, the PosH and the normal control group decreased visual dependency on repetition of the visual tasks after the Hallpike manoeuvre. NegH patients differed from PosH patients in that their high visual dependency did not diminish on repetition of the visual stimuli; they scored higher on the situational characteristic questionnaire ('visual vertigo' symptoms) and showed higher incidence of migraine. We conclude that long term vestibular symptoms increase visual dependence but a single BPPV attack does not increase it further. Repetitive visual motion stimulation induces adaptation in visual dependence in peripheral vestibular disorders such as BPPV. A positional form of vestibular migraine may underlie the symptoms of some patients with a history of BPPV but negative Hallpike manoeuvre. The finding that they have non adaptable increased visual dependency may explain visuo-vestibular symptoms in this group and, perhaps more widely, in patients with migraine.

  6. Self-Esteem, Locus of Control and Various Aspects of Psychopathology of Adults with Visual Impairments

    Science.gov (United States)

    Papadopoulos, Konstantinos; Paralikas, Theodosis; Barouti, Marialena; Chronopoulou, Elena

    2014-01-01

    The exploratory study presented in this article looks into the possible differences in psychosocial aspects (self-esteem and locus of control) and aspects of psychopathology (depression, anxiety, melancholia, asthenia, and mania) amongst sighted adults and adults with visual impairments. Moreover, the study aims to examine the possible…

  7. Acute Caffeine Consumption Enhances the Executive Control of Visual Attention in Habitual Consumers

    Science.gov (United States)

    Brunye, Tad T.; Mahoney, Caroline R.; Lieberman, Harris R.; Giles, Grace E.; Taylor, Holly A.

    2010-01-01

    Recent work suggests that a dose of 200-400mg caffeine can enhance both vigilance and the executive control of visual attention in individuals with low caffeine consumption profiles. The present study seeks to determine whether individuals with relatively high caffeine consumption profiles would show similar advantages. To this end, we examined…

  8. Maternal Verbal Control Techniques with Young Infants during Mutual Gaze and Visual Co-Orientation Episodes.

    Science.gov (United States)

    Francis, Patricia L.; And Others

    1982-01-01

    Examines periods of mutual gaze and visual coorientation between mothers and their two- to four-month-old infants as contexts for the utilization of maternal verbal control techniques. Additional questions involve the impact of infant sex and maternal sensitivity upon the utilization of these techniques. (Author/MP)

  9. A port-Hamiltonian approach to visual servo control of a pick and place system

    NARCIS (Netherlands)

    Dirksz, Daniel A.; Scherpen, Jacquelien M.A.

    2012-01-01

    In this paper we take a port-Hamiltonian approach to address the problem of image-based visual servo control of a pick and place system. We realize a closed-loop system, including the nonlinear camera dynamics, which is port-Hamiltonian. Although the closed-loop system is nonlinear, the resulting

  10. Seroprevalence of hepatitis E virus among pregnant women and control subjects in China.

    Science.gov (United States)

    Cong, Wei; Sui, Jian-Chao; Zhang, Xiang-Yan; Qian, Ai-Dong; Chen, Jia; Zhu, Xing-Quan

    2015-03-01

    Hepatitis E infection, caused by the hepatitis E virus (HEV), is an important global public health concern, with particularly high mortality in pregnant women. China is generally judged to be an HEV-endemic area, but epidemiological data for HEV among pregnant women are limited. Between June 2011 and July 2013, a case-control study was conducted to estimate the seroprevalence and potential risk factors associated with the acquisition of HEV infection by pregnant women in China. Nine-hundred and ninety pregnant women who visited hospitals for antenatal follow-up or medication in Qingdao and Weihai and 965 control subjects matched by age, gender and residence were examined for the presence of anti-HEV IgG and IgM antibodies by enzyme immunoassays. Socio-demographic and behavioral characteristics from the study subjects were obtained. The overall prevalence of anti-HEV IgG in all 1,955 samples was 20.7%. In pregnant women, 16.2% of samples were anti-HEV IgG positive whereas, in control subjects 25.3% of samples were anti-HEV IgG positive, (P pregnant women and control subjects was 2.6% and 3.6%, respectively. Age, contact with cats, contact with pigs and exposure to soil were found to be associated with HEV infection. These findings demonstrated the high prevalence of HEV and the considerable potential for the transmission of HEV infection in pregnant women in China. © 2014 Wiley Periodicals, Inc.

  11. Single muscle fibre contractile properties differ between body-builders, power athletes and control subjects.

    Science.gov (United States)

    Meijer, J P; Jaspers, R T; Rittweger, J; Seynnes, O R; Kamandulis, S; Brazaitis, M; Skurvydas, A; Pišot, R; Šimunič, B; Narici, M V; Degens, H

    2015-11-01

    What is the central question of this study? Do the contractile properties of single muscle fibres differ between body-builders, power athletes and control subjects? What is the main finding and its importance? Peak power normalized for muscle fibre volume in power athletes is higher than in control subjects. Compared with control subjects, maximal isometric tension (normalized for muscle fibre cross-sectional area) is lower in body-builders. Although this difference may be caused in part by an apparent negative effect of hypertrophy, these results indicate that the training history of power athletes may increase muscle fibre quality, whereas body-building may be detrimental. We compared muscle fibre contractile properties of biopsies taken from the vastus lateralis of 12 body-builders (BBs; low- to moderate-intensity high-volume resistance training), six power athletes (PAs; high-intensity, low-volume combined with aerobic training) and 14 control subjects (Cs). Maximal isotonic contractions were performed in single muscle fibres, typed with SDS-PAGE. Fibre cross-sectional area was 67 and 88% (P power (PP) of PA fibres was 58% higher than that of BB fibres (P < 0.05), whereas BB fibres, despite considerable hypertrophy, had similar PP to the C fibres. This work suggests that high-intensity, low-volume resistance training with aerobic exercise improves PP, while low- to moderate-intensity high-volume resistance training does not affect PP and results in a reduction in specific tension. We postulate that the decrease in specific tension is caused by differences in myofibrillar density and/or post-translational modifications of contractile proteins. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

  12. Control Design of Active Magnetic Bearings for Rotors Subjected to Destabilising Seal Forces - Theory & Experiment

    DEFF Research Database (Denmark)

    Lauridsen, Jonas Skjødt

    advantages over traditional types of bearings, including: no mechanical contact, no lubrication, low maintenance, low vibration level, high rotational speed and low energy consumption. These advantagesmake AMBs especially useful in challenging environments, for instance in subsea turbomachinery applications....... The main original contribution of the thesis is the framework for design of model based controllers for AMB systems subjected to uncertainand changing dynamic seal forces. An identification method has been developed, and experimentally validated, to obtain precise models of Linear Fractional Transformation...

  13. Cortisol and subjective stress responses to acute psychosocial stress in fibromyalgia patients and control participants.

    Science.gov (United States)

    Coppens, Eline; Kempke, Stefan; Van Wambeke, Peter; Claes, Stephan; Morlion, Bart; Luyten, Patrick; Van Oudenhove, Lukas

    2017-12-11

    Hypothalamic-pituitary-adrenal (HPA) axis dysfunction may play a role in fibromyalgia (FM) pathogenesis, but remains understudied in this disorder. Furthermore, early childhood adversities (ECA) are common in FM, but whether they moderate stress reactivity is unknown. Hence, we investigated cortisol and subjective responses to acute psychosocial stress in FM and controls, while adjusting for ECA. Twenty-seven female FM patients and 24 age-matched female controls were recruited in a tertiary care center and through advertisements, respectively. The Childhood Trauma Questionnaire was used to measure ECA history. Salivary cortisol levels and subjective stress ratings were measured at multiple time points before and after the Trier Social Stress Test (TSST) was administered. Significant main effects of group [F(1,43)=7.04, p=0.011, lower in FM] and ECA [F(1,43)=5.18, p=0.028, higher in participants with ECA] were found for cortisol responses. When excluding controls with ECA (n=5), a significant group-by-time interaction was found [F(6,39)=2.60, p=0.032], driven by a blunted response to the stressor in FM compared with controls (p=0.037). For subjective stress responses, a significant main effect of group [F(1,45)=10.69, p=0.002, higher in FM] and a trend towards a group-by-time interaction effect [F(6,45)=2.05, p=0.078, higher in FM 30 minutes before and 30 and 75 minutes after the TSST, and impaired recovery (difference immediately after - 30 minutes after the TSST) in FM] were found. Blunted cortisol responsivity to the TSST was observed in FM patients compared with controls without ECA. FM patients had higher subjective stress levels compared with controls, particularly at baseline and during recovery from the TSST. In FM patients, ECA history was not associated with cortisol or subjective stress levels, or with responsivity to the TSST. Future research should investigate the mechanisms underlying HPA axis dysregulation in FM.

  14. Measuring executive function in control subjects and TBI patients with question completion time (QCT).

    Science.gov (United States)

    Woods, David L; Yund, E William; Wyma, John M; Ruff, Ron; Herron, Timothy J

    2015-01-01

    Questionnaire completion is a complex task that places demands on cognitive functions subserving reading, introspective memory, decision-making, and motor control. Although computerized questionnaires and surveys are used with increasing frequency in clinical practice, few studies have examined question completion time (QCT), the time required to complete each question. Here, we analyzed QCTs in 172 control subjects and 31 patients with traumatic brain injury (TBI) who completed two computerized questionnaires, the 17-question Post-Traumatic Stress Disorder (PTSD) Checklist (PCL) and the 25-question Cognitive Failures Questionnaire (CFQ). In control subjects, robust correlations were found between self-paced QCTs on the PCL and CFQ (r = 0.82). QCTs on individual questions correlated strongly with the number of words in the question, indicating the critical role of reading speed. QCTs increased significantly with age, and were reduced in females and in subjects with increased education and computer experience. QCT z-scores, corrected for age, education, computer use, and sex, correlated more strongly with each other than with the results of other cognitive tests. Patients with a history of severe TBI showed significantly delayed QCTs, but QCTs fell within the normal range in patients with a history of mild TBI. When questionnaires are used to gather relevant patient information, simultaneous QCT measures provide reliable and clinically sensitive measures of processing speed and executive function.

  15. Positive Periodic Solutions of a Periodic Discrete Competitive System Subject to Feedback Controls

    Directory of Open Access Journals (Sweden)

    Ronghua Tan

    2014-01-01

    Full Text Available Species living in a fluctuating medium and human exploitation activities might result in the duration of continuous changes. Such changes can be well-approximated as feedback controls. In this contribution a periodic discrete competitive system subject to feedback controls is proposed. By using the methods of discrete inequality, fixed point theorem, and analysis techniques, a good understanding of the existence and global asymptotic stability of positive periodic solutions is obtained. Some numerical investigations are provided to verify our analytical results.

  16. Separation of Parkinson's patients in early and mature stages from control subjects using one EOG channel

    DEFF Research Database (Denmark)

    Christensen, Julie A.E.; Frandsen, Rune; Kempfner, Jacob

    2012-01-01

    In this study, polysomnographic left side EOG signals from ten control subjects, ten iRBD patients and ten Parkinson's patients were decomposed in time and frequency using wavelet transformation. A total of 28 features were computed as the means and standard deviations in energy measures from...... different reconstructed detail subbands across all sleep epochs during a whole night of sleep. A subset of features was chosen based on a cross validated Shrunken Centroids Regularized Discriminant Analysis, where the controls were treated as one group and the patients as another. Classification...

  17. Distribution of haematological indices among subjects with Blastocystis hominis infection compared to controls.

    Science.gov (United States)

    Javaherizadeh, Hazhir; Khademvatan, Shahram; Soltani, Shahrzad; Torabizadeh, Mehdi; Yousefi, Elham

    2014-01-01

    Some studies suggest Blastocystis hominis is a potentially pathogenic protozoa. Blastocystis hominis contributed to anaemia in children aged 8-10 years old in one study. To compare haematological indices in cases with blastocystis hominis infection with healthy controls. From 2001 to 2012, 97600 stool examinations were done in 4 university hospitals. Parasites were observed in 46,200 specimens. Of these cases, subjects with complete laboratory investigation (complete blood count - CBC, ferritin, total iron binding capacity - TIBC, and serum) and blastocystis hominis infection were included in this study as the case group. Of these cases, 6851 cases had only B. hominis infection. In the control group, 3615 subjects without parasite infestation were included. Age, haemoglobin (Hb), serum iron, TIBC, white blood cell (WBC), platelet (PLT), mean corpuscular volume (MCV), haematocrit (HCT) and erythrocyte sedimentation rate (ESR) were recorded for cases and controls. SPSS software version 13.0 was used for analysis. Independent sample t-test and χ(2) tests were used for comparison. Erythrocyte sedimentation rate level was significantly higher in cases with B. hominis infection (p hominis infection compared to controls. Occult blood was positive in 0.93% of cases and in none of the controls (p hominis infection.

  18. Nonlinear Dynamic Characteristics and Optimal Control of SMA Composite Wings Subjected to Stochastic Excitation

    Directory of Open Access Journals (Sweden)

    Zhi-Wen Zhu

    2015-01-01

    Full Text Available A kind of high-aspect-ratio shape memory alloy (SMA composite wing is proposed to reduce the wing’s fluttering. The nonlinear dynamic characteristics and optimal control of the SMA composite wings subjected to in-plane stochastic excitation are investigated where the great bending under the flight loads is considered. The stochastic stability of the system is analyzed, and the system’s response is obtained. The conditions of stochastic Hopf bifurcation are determined, and the probability density of the first-passage time is obtained. Finally, the optimal control strategy is proposed. Numerical simulation shows that the stability of the system varies with bifurcation parameters, and stochastic Hopf bifurcation appears in the process; the reliability of the system is improved through optimal control, and the first-passage time is delayed. Finally, the effects of the control strategy are proved by experiments. The results of this paper are helpful for engineering applications of SMA.

  19. [Comparative analysis of the glycemic response and glycemic index of instant mashed potatoes in subjects undergoing laparoscopic sleeve gastrectomy and control subjects].

    Science.gov (United States)

    Fuentes Valdes, Gabriel; del Valle Flores, Miguel; Vega Soto, Claudia

    2014-12-01

    The laparoscopic sleeve gastrectomy (LSG) is a successful surgical procedure for morbid obesity. However, post surgery weight regain is usual, thus applying the glycemic index could promote good weight control. To compare the glycemic index (GI) and glycemic response (GR) obtained of instant mashed potatoes in individuals subjected to LSG versus control subjects. GI and GR were assessed in 10 LSG subjects and compared with 10 controls. GI methodology proposed by FAO/WHO was used; instant mashed potatoes as test food and white bread as standard food (50g available CHO). Capillary blood sample 0 (fasting), 30, 60, 90 and 120 minutes. The GI was determined by trapezoidal method. ANOVA was used to compare a factor between RG and IG groups; t-student to compare RG between foods. Statistical significance pglycemic responses in LSG group, and its consumption possibly favoring weight regain. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  20. Objective approach for fending off the sublingual immunotherapy placebo effect in subjects with pollenosis: double-blinded, placebo-controlled trial.

    Science.gov (United States)

    Kralimarkova, Tanya Z; Popov, Todor A; Staevska, Maria; Mincheva, Roxana; Lazarova, Cvetelina; Racheva, Rumyana; Mustakov, Tihomir B; Filipova, Violina; Koleva, Margarita; Bacheva, Kalina; Dimitrov, Vasil D

    2014-07-01

    Symptom scoring for the assessment of allergen immunotherapy is associated with a substantial placebo effect. To assess the ability of exhaled breath temperature (EBT), a putative marker of airway inflammation, to evaluate objectively the efficacy of grass pollen sublingual immunotherapy in a proof-of-concept study. This was a double-blinded, placebo-controlled clinical trial in 56 subjects (mean ± SD 30 ± 12 years old, 33 men) sensitized to grass pollen. The objective measurements were EBT, spirometry, and periostin and high-sensitivity C-reactive protein in blood. Overall discomfort scored on a visual analog scale was used as a proxy for subjective symptoms. Evaluations were performed before, during, and after the grass pollen season. Fifty-one subjects (25 and 26 in the active treatment and placebo groups, respectively) were assessed before and during the pollen season. The mean pre- vs in-season increase in EBT was significantly smaller (by 59.1%) in the active treatment than in the placebo group (P = .030). Of the other objective markers, only the blood periostin level increased significantly during the pollen season (P = .047), but without intergroup differences. Subjectively, the mean pre- vs in-season increase in the visual analog scale score was 32.3% smaller in the active treatment than in the placebo group, although this difference did not reach statistical significance (P = .116). These results suggest that the efficacy of grass pollen sublingual immunotherapy can be assessed by EBT, a putative quantitative measurement of airway inflammation, which is superior in its power to discriminate between active and placebo treatment than a subjective assessment of symptoms assessed on a visual analog scale. clinicaltrials.gov Identifier: NCT01785394. Copyright © 2014 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  1. Effects of food-related stimuli on visual spatial attention in fasting and nonfasting normal subjects: Behavior and electrophysiology.

    Science.gov (United States)

    Leland, D S; Pineda, J A

    2006-01-01

    Attention biases toward food-related stimuli were examined as mediators of normal, healthy motivated behavior. Reaction times (RTs) and event-related potentials (ERPs) were used to assess the impact of food-related words on normal food-deprived individuals when used as spatial cues that frequently predicted the location of targets in a simple detection task (75% validity). In Experiment 1, fasting and nonfasting subjects showed a magnified cost/benefit of invalid/valid cueing by food words relative to a neutral category of words. In Experiment 2, the RT effect was replicated in a group of fasting subjects. The amplitude of a P3-like positivity (P420) was enhanced in response to food words, as was that of a prominent early anterior negativity (AN). These findings demonstrate that food-related stimuli can bias spatial attention in normal subjects and that electrophysiological markers can index the motivational salience of food words and/or their effect on attentional capture in food-deprived individuals. Even when the motivational salience of spatial cues is irrelevant to task demands, it can have an observable effect on attention. This design allows for the behavioral and electrophysiological study of motivation-attention interactions through loading of spatial cues with motivation-related semantic properties.

  2. Audio-visual feedback improves the BCI performance in the navigational control of a humanoid robot.

    Science.gov (United States)

    Tidoni, Emmanuele; Gergondet, Pierre; Kheddar, Abderrahmane; Aglioti, Salvatore M

    2014-01-01

    Advancement in brain computer interfaces (BCI) technology allows people to actively interact in the world through surrogates. Controlling real humanoid robots using BCI as intuitively as we control our body represents a challenge for current research in robotics and neuroscience. In order to successfully interact with the environment the brain integrates multiple sensory cues to form a coherent representation of the world. Cognitive neuroscience studies demonstrate that multisensory integration may imply a gain with respect to a single modality and ultimately improve the overall sensorimotor performance. For example, reactivity to simultaneous visual and auditory stimuli may be higher than to the sum of the same stimuli delivered in isolation or in temporal sequence. Yet, knowledge about whether audio-visual integration may improve the control of a surrogate is meager. To explore this issue, we provided human footstep sounds as audio feedback to BCI users while controlling a humanoid robot. Participants were asked to steer their robot surrogate and perform a pick-and-place task through BCI-SSVEPs. We found that audio-visual synchrony between footsteps sound and actual humanoid's walk reduces the time required for steering the robot. Thus, auditory feedback congruent with the humanoid actions may improve motor decisions of the BCI's user and help in the feeling of control over it. Our results shed light on the possibility to increase robot's control through the combination of multisensory feedback to a BCI user.

  3. Audio-visual feedback improves the BCI performance in the navigational control of a humanoid robot

    Directory of Open Access Journals (Sweden)

    Emmanuele eTidoni

    2014-06-01

    Full Text Available Advancement in brain computer interfaces (BCI technology allows people to actively interact in the world through surrogates. Controlling real humanoid robots using BCI as intuitively as we control our body represents a challenge for current research in robotics and neuroscience. In order to successfully interact with the environment the brain integrates multiple sensory cues to form a coherent representation of the world. Cognitive neuroscience studies demonstrate that multisensory integration may imply a gain with respect to a single modality and ultimately improve the overall sensorimotor performance. For example, reactivity to simultaneous visual and auditory stimuli may be higher than to the sum of the same stimuli delivered in isolation or in temporal sequence. Yet, knowledge about whether audio-visual integration may improve the control of a surrogate is meager. To explore this issue, we provided human footstep sounds as audio feedback to BCI users while controlling a humanoid robot. Participants were asked to steer their robot surrogate and perform a pick-and-place task through BCI-SSVEPs. We found that audio-visual synchrony between footsteps sound and actual humanoid’s walk reduces the time required for steering the robot. Thus, auditory feedback congruent with the humanoid actions may improve motor decisions of the BCI’s user and help in the feeling of control over it. Our results shed light on the possibility to increase robot’s control through the combination of multisensory feedback to a BCI user.

  4. Revisión de Esquemas de Control Visual y Propuesta de Mejora

    Directory of Open Access Journals (Sweden)

    Luis Gracia

    2010-04-01

    Full Text Available Resumen: En este trabajo se realiza una revisión crítica de los esquemas de control visual desarrollados hasta la fecha y se propone uno nuevo que los mejora en varios aspectos. En primer lugar se introducen los esquemas básicos que permiten clasificar los tipos de control visual y se delimita la problemática a resolver: el control visual indirecto basado en posición. Posteriormente se abordan de forma crítica y unificada los distintos esquemas desarrollados previamente así como el propuesto en este trabajo. En particular, el esquema propuesto evita los inconvenientes de los anteriores y los mejora bajo distintos puntos de vista: funciones de transferencia bajo un marco ideal; condiciones para error en régimen permanente nulo; márgenes de estabilidad; etc. Todos los esquemas son analizados comparativamente en simulación para evidenciar la mejora obtenida con el planteamiento propuesto. Finalmente, se muestran resultados experimentales obtenidos para un robot cartesiano de tres ejes que permiten para validar el esquema de control desarrollado. Palabras clave: Control en lazo cerrado, robótica, control de robots, márgenes de estabilidad

  5. Cognitive Control and White Matter Callosal Microstructure in Methamphetamine Dependent Subjects: A DTI Study

    Science.gov (United States)

    Salo, Ruth; Nordahl, Thomas E; Buonocore, Michael H; Natsuaki, Yutaka; Waters, Christy; Moore, Charles D; Galloway, Gantt P; Leamon, Martin H

    2009-01-01

    Background Methamphetamine (MA) abuse causes damage to structures within the human cerebrum, with particular susceptibility to white matter (WM). Abnormalities have been reported in anterior regions with less evidence of changes in posterior regions. MA abusers have also shown deficits on attention tests that measure response conflict and cognitive control. Methods We examined cognitive control using a computerized measure of the Stroop selective attention task and indices of WM microstructure obtained from diffusion tensor imaging (DTI) in the callosal genu and splenium of 37 currently abstinent MA abusers and 17 non-substance abusing controls. Measurements of Fractional Anisotropy (FA), apparent diffusion coefficient (ADC) of callosal fibers and diffusion tensor eigenvalues were obtained in all subjects. Results The MA abusers exhibited greater Stroop reaction time interference (i.e., reduced cognitive control) [p=.04] compared to controls. After correcting for multiple comparisons, FA within the genu correlated significantly with measures of cognitive control in the MA abusers [p=.04, bonferroni corrected] but not in controls [p=.26]. Group differences in genu, but not splenium, FA were trend significant [p=.09]. Conclusions MA abuse appears to alter anterior callosal WM microstructure with less evidence of change within posterior callosal WM microstructure. DTI indices within the genu, but not splenium, correlated with measures of cognitive control in chronic MA abusers. PMID:18814867

  6. Differences in performance on the functional movement screen between chronic low back pain patients and healthy control subjects

    OpenAIRE

    Ko, Min-Joo; Noh, Kyung-Hee; Kang, Min-Hyeok; Oh, Jae-Seop

    2016-01-01

    [Purpose] Differences in scores on the Functional Movement Screen between patients with chronic lower back pain and healthy control subjects were investigated. [Subjects and Methods] In all, 20 chronic lower back pain patients and 20 healthy control subjects were recruited. Chronic lower back pain patients and healthy controls performed the Functional Movement Screen (deep squat, hurdle step, inline lunge, shoulder mobility, active straight leg raise, trunk stability pushup, and rotary stabil...

  7. Safety and pharmacokinetics of oral delta-9-tetrahydrocannabinol in healthy older subjects: a randomized controlled trial.

    Science.gov (United States)

    Ahmed, Amir I A; van den Elsen, Geke A H; Colbers, Angela; van der Marck, Marjolein A; Burger, David M; Feuth, Ton B; Rikkert, Marcel G M Olde; Kramers, Cornelis

    2014-09-01

    There is a great concern about the safety of THC-based drugs in older people (≥65 years), as most of THC-trials did not include such group. In this phase 1, randomized, double-blind, double-dummy, placebo-controlled, cross-over trial, we evaluated the safety and pharmacokinetics of three oral doses of Namisol(®), a novel THC in tablet form, in older subjects. Twelve healthy older subjects (6 male; mean age 72±5 years) randomly received a single oral dose of 3mg, 5mg, or 6.5mg of THC or matching placebo, in a crossover manner, on each intervention day. The data for 11 subjects were included in the analysis. The data of 1 subject were excluded due to non-compliance to study medication. THC was safe and well tolerated. The most frequently reported adverse events (AEs) were drowsiness (27%) and dry mouth (11%). Subjects reported more AEs with THC 6.5mg than with 3mg (p=0.048), 5mg (p=0.034) and placebo (p=0.013). There was a wide inter-individual variability in plasma concentrations of THC. Subjects for whom the Cmax fell within the sampling period (over 2h), Cmax was 1.42-4.57ng/mL and Tmax was 67-92min. The AUC0-2h (n=11) was 1.67-3.51ng/mL. Overall, the pharmacodynamic effects of THC were smaller than effects previously reported in young adults. In conclusion, THC appeared to be safe and well tolerated by healthy older individuals. Data on safety and effectiveness of THC in frail older persons are urgently required, as this population could benefit from the therapeutic applications of THC. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  8. Pharmacokinetics, Safety and Cognitive Function Profile of Rupatadine 10, 20 and 40 mg in Healthy Japanese Subjects: A Randomised Placebo-Controlled Trial.

    Science.gov (United States)

    Täubel, Jörg; Ferber, Georg; Fernandes, Sara; Lorch, Ulrike; Santamaría, Eva; Izquierdo, Iñaki

    2016-01-01

    Rupatadine is a marketed second generation antihistamine, with anti-PAF activity, indicated for symptomatic treatment of allergic rhinitis and urticaria. This study was conducted to evaluate the pharmacokinetics (PK), pharmacodynamics (PD), safety and tolerability of rupatadine in healthy Japanese subjects after single and multiple oral doses. In this randomised, double-blind, placebo-controlled study, 27 male and female healthy Japanese subjects were administered single and multiple escalating rupatadine dose of 10, 20 and 40 mg or placebo. Blood samples were collected at different time points for PK measurements and subjects were assessed for safety and tolerability. The effect of rupatadine on cognitive functioning was evaluated by means of computerized cognitive tests: rapid visual information processing (RVP), reaction time (RT), spatial working memory (SWM) and visual analogue scales (VAS). Exposure to rupatadine as measured by Cmax and AUC was found to increase in a dose dependent manner over the dose range of 10-40 mg for both single and multiple dose administration. The safety assessments showed that all treatment related side effects were of mild intensity and there were no serious adverse events (SAEs) or withdrawals due to treatment-emergent adverse events (TEAEs) in this study. The therapeutic dose of rupatadine did not show any CNS impairment in any of the cognitive tests. This study demonstrated that rupatadine is safe and well tolerated by Japanese healthy subjects. The PK-PD profile confirmed previous experience with rupatadine.

  9. Motor control patterns during an active straight leg raise in pain-free subjects.

    Science.gov (United States)

    Beales, Darren John; O'Sullivan, Peter Bruce; Briffa, N Kathryn

    2009-01-01

    Repeated measures. To investigate motor control (MC) patterns of normal subjects during the low level physical load of the active straight leg raise (ASLR). Aberrant MC patterns, as observed with the ASLR test, are considered to be a mechanism for ongoing pain and disability in subjects with chronic musculoskeletal pelvic girdle pain. These patterns may not only affect the provision of lumbopelvic stability, but also respiration and the control of continence. Greater understanding of MC patterns in pain-free subjects may improve the management of pelvic girdle pain. METHODS.: Fourteen pain-free nulliparous women were examined during the ASLR. Electromyography of the anterior abdominal wall, right chest wall and the anterior scaleni, intraabdominal pressure (IAP), intrathoracic pressure (ITP), respiratory rate, pelvic floor kinematics, and downward leg pressure of the nonlifted leg were compared between a left and right ASLR. There was greater activation of obliquus internus abdominis and obliquus externus abdominis on the side of the ASLR. The predominant pattern of activation for the chest wall was tonic activation during an ipsilateral ASLR, and phasic respiratory activation lifting the contralateral leg. Respiratory fluctuation of both IAP and ITP did not differ lifting either leg. The baseline shifts of these pressure variables in response to the physical demand of lifting the leg was also the same either side. There was no difference in respiratory rate, pelvic floor kinematics, or downward leg pressure. Pain-free subjects demonstrate a predominant pattern of greater ipsilateral tonic activation of the abdominal wall and chest wall on the side of the ASLR. This was achieved with minimal apparent disruption to IAP and ITP. The findings of this study demonstrate the plastic nature of the abdominal cylinder and the flexibility of the neuromuscular system in controlling load transference during an ASLR.

  10. Cue-Reactive Rationality, Visual Imagery and Volitional Control Predict Cue-Reactive Urge to Gamble in Poker-Machine Gamblers.

    Science.gov (United States)

    Clark, Gavin I; Rock, Adam J; McKeith, Charles F A; Coventry, William L

    2016-11-01

    Poker-machine gamblers have been demonstrated to report increases in the urge to gamble following exposure to salient gambling cues. However, the processes which contribute to this urge to gamble remain to be understood. The present study aimed to investigate whether changes in the conscious experience of visual imagery, rationality and volitional control (over one's thoughts, images and attention) predicted changes in the urge to gamble following exposure to a gambling cue. Thirty-one regular poker-machine gamblers who reported at least low levels of problem gambling on the Problem Gambling Severity Index (PGSI), were recruited to complete an online cue-reactivity experiment. Participants completed the PGSI, the visual imagery, rationality and volitional control subscales of the Phenomenology of Consciousness Inventory (PCI), and a visual analogue scale (VAS) assessing urge to gamble. Participants completed the PCI subscales and VAS at baseline, following a neutral video cue and following a gambling video cue. Urge to gamble was found to significantly increase from neutral cue to gambling cue (while controlling for baseline urge) and this increase was predicted by PGSI score. After accounting for the effects of problem-gambling severity, cue-reactive visual imagery, rationality and volitional control significantly improved the prediction of cue-reactive urge to gamble. The small sample size and limited participant characteristic data restricts the generalizability of the findings. Nevertheless, this is the first study to demonstrate that changes in the subjective experience of visual imagery, volitional control and rationality predict changes in the urge to gamble from neutral to gambling cue. The results suggest that visual imagery, rationality and volitional control may play an important role in the experience of the urge to gamble in poker-machine gamblers.

  11. Robust adaptive control modeling of human arm movements subject to altered gravity and mechanical loads

    Science.gov (United States)

    Tryfonidis, Michail

    It has been observed that during orbital spaceflight the absence of gravitation related sensory inputs causes incongruence between the expected and the actual sensory feedback resulting from voluntary movements. This incongruence results in a reinterpretation or neglect of gravity-induced sensory input signals. Over time, new internal models develop, gradually compensating for the loss of spatial reference. The study of adaptation of goal-directed movements is the main focus of this thesis. The hypothesis is that during the adaptive learning process the neural connections behave in ways that can be described by an adaptive control method. The investigation presented in this thesis includes two different sets of experiments. A series of dart throwing experiments took place onboard the space station Mir. Experiments also took place at the Biomechanics lab at MIT, where the subjects performed a series of continuous trajectory tracking movements while a planar robotic manipulandum exerted external torques on the subjects' moving arms. The experimental hypothesis for both experiments is that during the first few trials the subjects will perform poorly trying to follow a prescribed trajectory, or trying to hit a target. A theoretical framework is developed that is a modification of the sliding control method used in robotics. The new control framework is an attempt to explain the adaptive behavior of the subjects. Numerical simulations of the proposed framework are compared with experimental results and predictions from competitive models. The proposed control methodology extends the results of the sliding mode theory to human motor control. The resulting adaptive control model of the motor system is robust to external dynamics, even those of negative gain, uses only position and velocity feedback, and achieves bounded steady-state error without explicit knowledge of the system's nonlinearities. In addition, the experimental and modeling results demonstrate that

  12. [Comparison of Inflammatory Biomarkers Between Bipolar Disorder I Patients and Control Subjects].

    Science.gov (United States)

    Palacio, Juan David; Guzman, Sandra; Vargas, Cristian; Díaz-Zuluaga, Ana María; López-Jaramillo, Carlos

    2016-01-01

    Inflammatory changes have been described in different affective episodes, as well as in the euthymic phase of Bipolar I Disease. These changes have been proposed as possible peripheral markers of the disease. For this reason well-designed studies are needed to explore this hypothesis. Quantify and compare the serum levels of interleukins (IL) and tumour necrosis factor (TNF) in bipolar I patients and healthy subjects, including the comparison between the affective episodes of the disease. Cross-sectional study including 41 bipolar I patients and 11 healthy control subjects. Serum levels of IL-1B, IL-RA, IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, and TNF were measured during the euthymic, depressive, and manic phases and were compared with the serum levels of the healthy subjects. Manic phase patients had low education and high number of hospitalisations. Depressive phase patients showed high number of depressive episodes throughout life. No statistically significant differences were found in IL and TNF levels between bipolar I patients and healthy controls, or between the bipolar I subgroups (euthymic, manic and depressive states). An increase in the size of the sample is necessary in future studies, in order to enhance the statistical value of the results, and explore the inflammatory hypothesis of the bipolar disease. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  13. A CMOS Visual Sensing System for Welding Control and Information Acquirement in SMAW Process

    Science.gov (United States)

    Anren, Yao; Zhen, Luo; Sansan, Ao

    A sequential research work on visual information of manual arc welding pool dynamics are presented in this paper. An optical inspection system, for monitoring the shielded manual arc welding (SMAW) process is described. The system consisted of a vision sensor that consisted of a Complementary Metal Oxide Semiconductor (CMOS) camera and lenses, image processing algorithms, and a computer controller. During welding, an image of the weld pool and its vicinity was captured when basic current of welding power. Experimental results showed that the temperature signal varies greatly in the case of instabilities of the weld pool that cause weld defects. The visual information acquirement methods are focused in computer vision sensing, image processing and characteristic extraction of the weld pool surface from the single-item pool images by particular algorithms control strategies are developed to control welding pool dynamics during SMAW.

  14. Visual Control for Unicycle-Like Mobile Robots Formation Under the Leader-Follower Scheme

    Directory of Open Access Journals (Sweden)

    Bugarin-Carlos Eusebio

    2014-10-01

    Full Text Available This paper describes a visual control proposal for the formation of unicycle-like mobile robots under the leader-follower scheme. It is considered a single fixed camera observing the robots workspace that, in terms of the processed information, can be shared by both the leader robot and the follower robot. This would enable the implementation of this proposal to be performed by centralized or decentralized control strategies. For the purpose of simplifying the analysis, it is also considered that the image plane is parallel to the robots motion plane. The formation objective is established directly in image space and the proposed visual controller does not depend explicitly on the vision system parameters (extrinsic or intrinsic; which together represents the main contribution of this paper. Finally, also as an important part of this work, to validate the proposed theory satisfactory experiments using a real-time and high-speed vision system are detailed.

  15. Active control of the visual field in the starfish Acanthaster planci.

    Science.gov (United States)

    Beer, S; Wentzel, C; Petie, R; Garm, A

    2016-10-01

    Photoreception in echinoderms has been studied for several years with a focus on the dermal photoreceptors of echinoids. Even though spatial vision has been proposed for this dermal photosystem, by far the most advanced system is found in a number of asteroids where an unpaired tube foot at the tip of each arm carries a proper eye, also known as the optical cushion. The eyes resemble compound eyes, except for the lack of true optics, and they typically have between 50 and 250 ommatidia each. These eyes have been known for two centuries but no visually guided behaviors were known in starfish until recently when it was shown that both Linckia laevigata and Acanthaster planci navigate their coral reef habitat using vision. Here we investigate the visual system of A. planci and find that they have active control of their visual field. The distalmost tube foot holding the eye is situated on a movable knob, which bends to adjust the vertical angle of the visual field. On the leading arms the visual field is directed 33° above the horizon, whereas the eyes on the trailing arms are directed 44° above horizontal on average. When the animal traverses an obstacle the knob bends and counteracts most of the arm bending. Further, we examined a previously described behavior, rhythmic arm elevation, and suggest that it allows the animal to scan the surroundings while preventing photoreceptor adaptation and optimizing image contrast. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Lighting energy savings potential of split-pane electrochromic windows controlled for daylighting with visual comfort

    Energy Technology Data Exchange (ETDEWEB)

    Software, Anyhere; Fernandes, Luis; Lee, Eleanor; Ward, Greg

    2013-03-15

    A simulation study was conducted to evaluate lighting energy savings of split-pane electrochromic (EC) windows controlled to satisfy key visual comfort parameters. Using the Radiance lighting simulation software, interior illuminance and luminance levels were computed for a south-facing private office illuminated by a window split into two independently-controlled EC panes. The transmittance of these was optimized hourly for a workplane illuminance target while meeting visual comfort constraints, using a least-squares algorithm with linear inequality constraints. Blinds were successively deployed until visual comfort criteria were satisfied. The energy performance of electrochromics proved to be highly dependent on how blinds were controlled. With hourly blind position adjustments, electrochromics showed significantly higher (62percent and 53percent, respectively without and with overhang) lighting energy consumption than clear glass. With a control algorithm designed to better approximate realistic manual control by an occupant, electrochromics achieved significant savings (48percent and 37percent, respectively without and with overhang). In all cases, energy consumption decreased when the workplace illuminance target was increased. In addition, the fraction of time during which the occupant had an unobstructed view of the outside was significantly greater with electrochromics: 10 months out of the year versus a handful of days for the reference case.

  17. Controls and art inquiries at the intersection of the subjective and the objective

    CERN Document Server

    Egerstedt, Magnus

    2014-01-01

    Dancing humanoids, robotic art installations, and music generated by mathematically precise methods are no longer science fiction; in fact they are the subject of this book.  This first-of-its-kind anthology assembles technical research that makes such creations possible.  In order to mechanize something as enigmatic and personal as dance, researchers must delve deeply into two distinct academic disciplines: control theory and art.  Broadly, this research uses techniques from the world of art to inspire methods in control, enables artistic endeavours using advanced control theory, and aids in the analysis of art using metrics devised by a systems theoretic approach.  To ensure that artistic influences are well represented, the individual chapters are focused so that they relate their contribution to the arts meaningfully and explicitly. Specially composed introductions set up the contributions either in terms of inspiration by artistic principles or their contribution to the arts through new analysis tool...

  18. Real time control and numerical simulation of pipeline subjected to landslide

    Energy Technology Data Exchange (ETDEWEB)

    Cuscuna, S.; Giusti, G.; Gramola, C.

    1984-06-01

    This paper describes SNAM research activity in the study of behaviour and real-time control of pipelines in landslide areas. The subject can be delt considering three different aspects: 1. Geotechnical characterization of unstable soils. The mechanical parameters of soil and the landslide types are defined; 2. Structural analysis of pipe-soil system. By means of a finite element program it's possible to study the pipe-soil interaction; in this numerical code the soil parameters attend by the non-linear elastic behaviour of pipe restraints. The results of this analysis are the location of the expected most stressed sections of pipe and the global behaviour of pipe inside the soil. 3. Instrumental control. The adoption of a suitable appliance of vibrating wire strain gauges allows the strain control of pipe in time. The aim is to make possible timely interventions in order to guarantee the installation safety.

  19. Personality profiles between obese and control subjects assessed with five standardized personality scales.

    Science.gov (United States)

    López-Pantoja, José L; Cabranes, José A; Sanchez-Quintero, Sabrina; Velao, Manuel; Sanz, Montserrat; Torres-Pardo, Beatriz; Ancín, Inés; Cabrerizo, Lucio; Rubio, Miguel A; Lopez-Ibor, Juan J; Barabash, Ana

    2012-01-01

    Psychopathology may exert influence on developing and maintaining obesity. Studies of personality traits or psychopathology of personality in obesity are scarce and contradictory. The aim of this study was to compare personality profiles between obese and normal-weight subjects and to determine the most useful tool to detect differences, considering that psychological assessment and psychotherapeutical support should be included within the overall management of these patients.* We examined 55 obese subjects (mean BMI=43kg/ m2) and 66 controls (mean BMI =21.7kg/m2). We used the personality assessment tools: MCMI-II, TCI-R, EPQ-A, BIS-111 and SSS. Factorial multivariate analysis of variance was applied; with factors BMI, Gender and Age as a covariate. Significant differences between groups were more marked in the clinical syndrome scales of MCMI-II, particularly in Major-Depression, Thought-Disorder, Anxiety, Somatoform and Alcohol-Dependence. Among obese, women scored higher than men in all scales but not significantly. We have found significant differences in normal personality dimensions between both groups in TCI-R. Obese showed higher scores in Harm Avoidance, and lower in Novelty Seeking, Persistence and Self-transcendence. The remaining tests have not been useful for differentiating personality traits between both groups. Obese subjects showed different personality profiles than control subjects. The most useful scales for determining these differences might be those designed to assess pathological personality such as MCMI-II. Less important would be those intended to measure normal personality traits, such as TCI-R and EPQ-A.

  20. Brain-Computer Interfaces for 1-D and 2-D Cursor Control: Designs Using Volitional Control of the EEG Spectrum or Steady-State Visual Evoked Potentials

    Science.gov (United States)

    Trejo, Leonard J.; Matthews, Bryan; Rosipal, Roman

    2005-01-01

    We have developed and tested two EEG-based brain-computer interfaces (BCI) for users to control a cursor on a computer display. Our system uses an adaptive algorithm, based on kernel partial least squares classification (KPLS), to associate patterns in multichannel EEG frequency spectra with cursor controls. Our first BCI, Target Practice, is a system for one-dimensional device control, in which participants use biofeedback to learn voluntary control of their EEG spectra. Target Practice uses a KF LS classifier to map power spectra of 30-electrode EEG signals to rightward or leftward position of a moving cursor on a computer display. Three subjects learned to control motion of a cursor on a video display in multiple blocks of 60 trials over periods of up to six weeks. The best subject s average skill in correct selection of the cursor direction grew from 58% to 88% after 13 training sessions. Target Practice also implements online control of two artifact sources: a) removal of ocular artifact by linear subtraction of wavelet-smoothed vertical and horizontal EOG signals, b) control of muscle artifact by inhibition of BCI training during periods of relatively high power in the 40-64 Hz band. The second BCI, Think Pointer, is a system for two-dimensional cursor control. Steady-state visual evoked potentials (SSVEP) are triggered by four flickering checkerboard stimuli located in narrow strips at each edge of the display. The user attends to one of the four beacons to initiate motion in the desired direction. The SSVEP signals are recorded from eight electrodes located over the occipital region. A KPLS classifier is individually calibrated to map multichannel frequency bands of the SSVEP signals to right-left or up-down motion of a cursor on a computer display. The display stops moving when the user attends to a central fixation point. As for Target Practice, Think Pointer also implements wavelet-based online removal of ocular artifact; however, in Think Pointer muscle

  1. Effects of sleep deprivation on nocturnal cytokine concentrations in depressed patients and healthy control subjects.

    Science.gov (United States)

    Voderholzer, Ulrich; Fiebich, Bernd L; Dersch, Rick; Feige, Bernd; Piosczyk, Hannah; Kopasz, Marta; Riemann, Dieter; Lieb, Klaus

    2012-01-01

    Previous studies have reported alterations of cytokine and cytokine-receptor concentrations in psychiatric patient populations, including patients with major depressive disorder (MDD). However, study results are conflicting, and possible causes for these abnormalities are unknown. Since sleep deprivation may induce a rapid improvement of mood in depressed patients, the authors investigated the impact of total sleep deprivation (TSD) for one night, and subsequent recovery sleep, on nocturnal concentrations of interleukin-6 (IL-6), interleukin-1-receptor antagonist (IL-1RA), and soluble IL-2 receptor (sIL-2R) in 15 unmedicated patients with MDD and 16 healthy volunteers. Whereas IL-6 levels normalized again during the recovery night in depressed patients, they were still elevated in control subjects. Serum levels of IL-1RA were higher in depressed patients than in controls, but were not affected by TSD. During recovery sleep, IL-1RA levels increased as compared with the preceding TSD night only in controls. Responders (N=8) differed from nonresponders (N=7) to TSD with regard to IL-1RA, which increased significantly during TSD in responders only. Sleep deprivation therefore seems to significantly affect cytokine levels in both depressed patients and healthy subjects, but does so in different ways. Sleep disturbances in depressed patients could account for the increased levels of cytokines found in these patients in several previous studies. The interaction between antidepressant effects of TSD and alterations of cytokines warrants further investigation.

  2. Comparison of Auditory Brainstem Response in Noise Induced Tinnitus and Non-Tinnitus Control Subjects

    Directory of Open Access Journals (Sweden)

    Ghassem Mohammadkhani

    2009-12-01

    Full Text Available Background and Aim: Tinnitus is an unpleasant sound which can cause some behavioral disorders. According to evidence the origin of tinnitus is not only in peripheral but also in central auditory system. So evaluation of central auditory system function is necessary. In this study Auditory brainstem responses (ABR were compared in noise induced tinnitus and non-tinnitus control subjects.Materials and Methods: This cross-sectional, descriptive and analytic study is conducted in 60 cases in two groups including of 30 noise induced tinnitus and 30 non-tinnitus control subjects. ABRs were recorded ipsilateraly and contralateraly and their latencies and amplitudes were analyzed.Results: Mean interpeak latencies of III-V (p= 0.022, I-V (p=0.033 in ipsilatral electrode array and mean absolute latencies of IV (p=0.015 and V (p=0.048 in contralatral electrode array were significantly increased in noise induced tinnitus group relative to control group. Conclusion: It can be concluded from that there are some decrease in neural transmission time in brainstem and there are some sign of involvement of medial nuclei in olivery complex in addition to lateral lemniscus.

  3. Visual servo walking control for humanoids with finite-time convergence and smooth robot velocities

    Science.gov (United States)

    Delfin, Josafat; Becerra, Hector M.; Arechavaleta, Gustavo

    2016-07-01

    In this paper, we address the problem of humanoid locomotion guided from information of a monocular camera. The goal of the robot is to reach a desired location defined in terms of a target image, i.e., a positioning task. The proposed approach allows us to introduce a desired time to complete the positioning task, which is advantageous in contrast to the classical exponential convergence. In particular, finite-time convergence is achieved while generating smooth robot velocities and considering the omnidirectional waking capability of the robot. In addition, we propose a hierarchical task-based control scheme, which can simultaneously handle the visual positioning and the obstacle avoidance tasks without affecting the desired time of convergence. The controller is able to activate or inactivate the obstacle avoidance task without generating discontinuous velocity references while the humanoid is walking. Stability of the closed loop for the two task-based control is demonstrated theoretically even during the transitions between the tasks. The proposed approach is generic in the sense that different visual control schemes are supported. We evaluate a homography-based visual servoing for position-based and image-based modalities, as well as for eye-in-hand and eye-to-hand configurations. The experimental evaluation is performed with the humanoid robot NAO.

  4. Randomized placebo controlled trial of furosemide on subjective perception of dyspnoea in patients with pulmonary oedema because of hypertensive crisis.

    Science.gov (United States)

    Holzer-Richling, Nina; Holzer, Michael; Herkner, Harald; Riedmüller, Eva; Havel, Christof; Kaff, Alfred; Malzer, Reinhard; Schreiber, Wolfgang

    2011-06-01

    To compare the administration of furosemide with placebo on the subjective perception of dyspnoea in patients with acute pulmonary oedema because of hypertensive crisis. Design  Randomized, controlled and double-blinded clinical trial. Municipal emergency medical service system and university-based emergency department. Fifty-nine patients with pulmonary oedema because of hypertensive crisis. Additional to administration of oxygen, morphine-hydrochloride and urapidil until the systolic blood pressure was below 160mmHg, the patients were randomized to receive furosemide 80mg IV bolus (furosemide group) or saline placebo (placebo group). The primary outcome was the subjective perception of dyspnoea as measured with a modified BORG scale at one hour after randomization. Secondary outcome parameters were the subjective perception of dyspnoea of patients as measured with a modified BORG scale and a visual analogue scale at 2, 3 and 6h after randomization of the patient; course of the systolic arterial pressure and peripheral oxygen saturation and lactate at admission and at 6h after admission. In 25 patients in the furosemide group and in 28 patients in the placebo group, a BORG score could be obtained. There was no statistically significant difference in the severity of dyspnoea at one hour after randomization (P=0·40). The median BORG score at 1h after randomization in the furosemide group was 3 (IQR 2 to 4) compared to 3 (IQR 2 to 7) in the placebo group (P=0·40). Those patients who were randomized to the placebo group needed higher doses of urapidil at 20min after randomization. There were no significant differences in the rate of adverse events, nonfatal cardiac arrests or death between the two groups. The subjective perception of dyspnoea in patients with hypertensive pulmonary oedema was not influenced by the application of a loop-diuretic. Therefore, additional furosemide therapy needs to be scrutinized in the therapy of these patients. © 2010 The Authors

  5. Visual-vestibular interactions in postural control during the execution of a dynamic task.

    Science.gov (United States)

    Bent, Leah R; McFadyen, Bradford J; Inglis, J Timothy

    2002-10-01

    The purpose of this experiment was to determine the interaction between visual and vestibular information during the transition from quiet standing to the completion of a forward step. Six subjects were asked to take one step forward at the sound of an audio tone, with their eyes open or closed, and terminate the step in a standing position. During stimulation trials, galvanic vestibular stimulation (GVS) was delivered 1500 ms before the auditory cue. GVS was delivered at an intensity three-fold that of each subject's quiet stance threshold with either stimulus right, left or no stimulation. Force data were collected from three forceplates for the calculation of centre of pressure (CoP), and kinematic data were used to calculate centre of mass (CoM) and body trajectories. In quiet stance all subjects responded to the GVS perturbation by demonstrating upper body segment roll and whole body sway towards the anode electrode. Unexpectedly, in the presence of vision during quiet stance, the upper body roll response was not attenuated, even though the CoP sway patterns were reduced when vision was available. During the initiation phase of the step, despite ongoing GVS stimulation, there were no significant effects seen in CoM, CoP or upper body roll responses. During step execution, however, both CoM displacement and upper body roll demonstrated significant effects and both responses were significantly reduced when subjects' eyes were open. Analysis of the medio-lateral CoP integrals also indicated a strong stimulation effect between conditions late in the execution phase, which were largely attenuated with vision. The results suggest that the importance of visual and vestibular information varies depending on the phase of the task. In addition, the different integration between visual and vestibular input during quiet standing suggests a dual role for vestibular information. We propose that vestibular information in quiet standing has a role in maintaining whole body

  6. EFFECTIVENESS OF MOTOR TASK INTERFERENCE DURING GAIT IN SUBJECTS WITH PARKINSON'S DISEASE: A RANDOMIZED CONTROLLED TRAIL

    Directory of Open Access Journals (Sweden)

    Jaya ShankerTedla

    2017-04-01

    Full Text Available Background: In this study, was to evaluated the effectiveness of motor task and cognitive task interference while walking to improve gait parameters of subjects with Parkinson’s disease. Methods: In this Randomized Controlled trial, 30 subjects with Parkinson’s disease of age group between 50and 70 years randomly divided into two groups. The first group had motor task interference, and the second group had calculation task interference while walking along with conventional physical therapy. Gait parameters recorded as outcome measures. Both the groups received 1-hour training for three weeks for one month. Results: As per the paired t-test values, there was significant (p<0.001 improvement in the gait parameters for both the group's pre and post training. Motor task interference showed better improvements than calculation-task interference group among subjects with Parkinson’s disease in all the gait parameters measured with a p-value less than 0.001. Conclusion: To improve the gait parameters for mild to moderately disabled patients with Parkinson’s disease, the dual task training by using motor task while gait training along with conventional Physical Therapy will be more useful than using cognitive task.

  7. Comparison of osteoprotegerin and vascular endothelial growth factor in normoalbuminuric Type 1 diabetic and control subjects.

    Science.gov (United States)

    Esteghamati, A; Arefzadeh, A; Zandieh, A; Salehi Sadaghiani, M; Noshad, S; Nakhjavani, M

    2013-01-01

    The aim of the current study was to evaluate the association of osteoprotegerin and vascular endothelial growth factor (VEGF) with glycemic indices and diabetes status. A total of 44 normoalbuminuric Type 1 diabetic patients and 44 healthy control subjects, matched for age, body mass index, sex ratio, and lipid measures were enrolled. Univariate and multivariate logistic regression analyses were used to determine the association of osteoprotegerin and VEGF with diabetes status. Further, linear regression analysis was performed to investigate the roles of osteoprotegerin and VEGF as determinants of glycated hemoglobin (HbA1c). Osteoprotegerin and VEGF were significantly elevated in diabetic subjects (2.76±0.85 vs 2.26±0.75 pmol/l and 187.1±92.7 vs 125.9±52.3 pg/ml, respectively, posteoprotegerin and VEGF for diabetes were 2.532 (1.003-6.392) and 1.021 (1.002-1.041), respectively (posteoprotegerin with HbA1c is independent of VEGF and vice versa (pOsteoprotegerin and VEGF are elevated in normoalbuminuric Type 1 diabetic subjects and are independently associated with glycemic indices and diabetes status.

  8. [Subjective family image in anorexia nervosa and bulimia nervosa in adolescence: a controlled study].

    Science.gov (United States)

    Karwautz, A; Haidvogl, M; Wagner, G; Nobis, G; Wöber-Bingöl, C; Friedrich, M H

    2002-11-01

    The family environments of patients with eating disorders have been studied extensively in recent decades. The "Subjective Family Image Test" is an instrument developed especially to measure differential perceptions by family members. Assessments of subjective family image in families of adolescents by means of this test have been carried out in only a few samples. We aimed first to investigate subjective perceptions by adolescents of their family relations in a larger clinical sample of female adolescents (n = 118) suffering from anorexia nervosa of either subtype or from bulimia nervosa and to compare these perceptions with those of healthy controls (n = 96). Second we investigated intra-familial differences in perception. The main findings were that bulimia nervosa patients perceived lower individual autonomy and lower emotional connectedness than all other groups, the adolescents with bulimia perceived significantly lower autonomy and emotional connectedness within the family than their fathers, and the restrictive anorexia nervosa patients perceived higher connectedness than their fathers. The relevance of these findings for understanding family dynamics are discussed.

  9. The Next Generation of Ground Operations Command and Control; Scripting in C no. and Visual Basic

    Science.gov (United States)

    Ritter, George; Pedoto, Ramon

    2010-01-01

    Scripting languages have become a common method for implementing command and control solutions in space ground operations. The Systems Test and Operations Language (STOL), the Huntsville Operations Support Center (HOSC) Scripting Language Processor (SLP), and the Spacecraft Control Language (SCL) offer script-commands that wrap tedious operations tasks into single calls. Since script-commands are interpreted, they also offer a certain amount of hands-on control that is highly valued in space ground operations. Although compiled programs seem to be unsuited for interactive user control and are more complex to develop, Marshall Space flight Center (MSFC) has developed a product called the Enhanced and Redesign Scripting (ERS) that makes use of the graphical and logical richness of a programming language while offering the hands-on and ease of control of a scripting language. ERS is currently used by the International Space Station (ISS) Payload Operations Integration Center (POIC) Cadre team members. ERS integrates spacecraft command mnemonics, telemetry measurements, and command and telemetry control procedures into a standard programming language, while making use of Microsoft's Visual Studio for developing Visual Basic (VB) or C# ground operations procedures. ERS also allows for script-style user control during procedure execution using a robust graphical user input and output feature. The availability of VB and C# programmers, and the richness of the languages and their development environment, has allowed ERS to lower our "script" development time and maintenance costs at the Marshall POIC.

  10. The Impact of Personal Attitude, Subjective Norm, and Perceived Behavioural Control on Entrepreneurial Intentions of Women

    Directory of Open Access Journals (Sweden)

    M. Sait DINC

    2016-05-01

    Full Text Available In the last decade, female entrepreneurship has been identified as one of the most important unutilised sources of economic growth. Entrepreneurial intention of women has become a key element in establishing a new business. The factors influencing entrepreneurial intention of women, particularly in developing countries, have attracted curiosity lot of attention. The purpose of the study is to examine the relationship between demographic variables, personal attitude, subjective norm, perceived behavioural control, and entrepreneurial intentions of women in Federation of Bosnia and Herzegovina. A total of 216 questionnaires were collected from women in two big cities in Bosnia: Tuzla and Sarajevo. Relationships between the variables were evaluated using factor analysis, reliability, correlations, descriptive statistics, and regression. The findings show a positive and significant influence of personal attitude and perceived behavioural control on entrepreneurial intention.

  11. Selecting category specific visual information: Top-down and bottom-up control of object based attention.

    Science.gov (United States)

    Corradi-Dell'Acqua, Corrado; Fink, Gereon R; Weidner, Ralph

    2015-09-01

    The ability to select, within the complexity of sensory input, the information most relevant for our purposes is influenced by both internal settings (i.e., top-down control) and salient features of external stimuli (i.e., bottom-up control). We here investigated using fMRI the neural underpinning of the interaction of top-down and bottom-up processes, as well as their effects on extrastriate areas processing visual stimuli in a category-selective fashion. We presented photos of bodies or buildings embedded into frequency-matched visual noise to the subjects. Stimulus saliency changed gradually due to an altered degree to which photos stood-out in relation to the surrounding noise (hence generating stronger bottom-up control signals). Top-down settings were manipulated via instruction: participants were asked to attend one stimulus category (i.e., "is there a body?" or "is there a building?"). Highly salient stimuli that were inconsistent with participants' attentional top-down template activated the inferior frontal junction and dorsal parietal regions bilaterally. Stimuli consistent with participants' current attentional set additionally activated insular cortex and the parietal operculum. Furthermore, the extrastriate body area (EBA) exhibited increased neural activity when attention was directed to bodies. However, the latter effect was found only when stimuli were presented at intermediate saliency levels, thus suggesting a top-down modulation of this region only in the presence of weak bottom-up signals. Taken together, our results highlight the role of the inferior frontal junction and posterior parietal regions in integrating bottom-up and top-down attentional control signals. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. STATIC AND DYNAMIC POSTURE CONTROL IN POSTLINGUAL COCHLEAR IMPLANTED PATIENTS: Effects of dual-tasking, visual and auditory inputs suppression

    Directory of Open Access Journals (Sweden)

    BERNARD DEMANZE eLaurence

    2014-01-01

    Full Text Available Posture control is based on central integration of multisensory inputs, and on internal representation of body orientation in space. This multisensory feedback regulates posture control and continuously updates the internal model of body’s position which in turn forwards motor commands adapted to the environmental context and constraints. The peripheral localization of the vestibular system, close to the cochlea, makes vestibular damage possible following cochlear implant (CI surgery. Impaired vestibular function in CI patients, if any, may have a strong impact on posture stability. The simple postural task of quiet standing is generally paired with cognitive activity in most day life conditions, leading therefore to competition for attentional resources in dual-tasking, and increased risk of fall particularly in patients with impaired vestibular function. This study was aimed at evaluating the effects of post-lingual cochlear implantation on posture control in adult deaf patients. Possible impairment of vestibular function was assessed by comparing the postural performance of patients to that of age-matched healthy subjects during a simple postural task performed in static and dynamic conditions, and during dual-tasking with a visual or auditory memory task. Postural tests were done in eyes open (EO and eyes closed (EC conditions, with the cochlear implant activated (ON or not (OFF. Results showed that the CI patients significantly reduced limits of stability and increased postural instability in static conditions. In dynamic conditions, they spent considerably more energy to maintain equilibrium, and their head was stabilized neither in space nor on trunk while the controls showed a whole body rigidification strategy. Hearing (prosthesis on as well as dual-tasking did not really improve the dynamic postural performance of the CI patients. We conclude that CI patients become strongly visual dependent mainly in challenging postural conditions.

  13. Circadian clock gene expression in brain regions of Alzheimer 's disease patients and control subjects.

    Science.gov (United States)

    Cermakian, Nicolas; Lamont, Elaine Waddington; Boudreau, Philippe; Boivin, Diane B

    2011-04-01

    Circadian oscillators have been observed throughout the rodent brain. In the human brain, rhythmic expression of clock genes has been reported only in the pineal gland, and little is known about their expression in other regions. The investigators sought to determine whether clock gene expression could be detected and whether it varies as a function of time of day in the bed nucleus of the stria terminalis (BNST) and cingulate cortex, areas known to be involved in decision making and motivated behaviors, as well as in the pineal gland, in the brains of Alzheimer's disease (AD) patients and aged controls. Relative expression levels of PERIOD1 (PER1 ), PERIOD2 (PER2), and Brain and muscle Arnt-like protein-1 (BMAL1) were detected by quantitative PCR in all 3 brain regions. A harmonic regression model revealed significant 24-h rhythms of PER1 in the BNST of AD subjects. A significant rhythm of PER2 was found in the cingulate cortex and BNST of control subjects and in all 3 regions of AD patients. In controls, BMAL1 did not show a diurnal rhythm in the cingulate cortex but significantly varied with time of death in the pineal and BNST and in all 3 regions for AD patients. Notable differences in the phase of clock gene rhythms and phase relationships between genes and regions were observed in the brains of AD compared to those of controls. These results indicate the presence of multiple circadian oscillators in the human brain and suggest altered synchronization among these oscillators in the brain of AD patients. © 2011 Sage Publications

  14. Finite-time tracking control for multiple non-holonomic mobile robots based on visual servoing

    Science.gov (United States)

    Ou, Meiying; Li, Shihua; Wang, Chaoli

    2013-12-01

    This paper investigates finite-time tracking control problem of multiple non-holonomic mobile robots via visual servoing. It is assumed that the pinhole camera is fixed to the ceiling, and camera parameters are unknown. The desired reference trajectory is represented by a virtual leader whose states are available to only a subset of the followers, and the followers have only interaction. First, the camera-objective visual kinematic model is introduced by utilising the pinhole camera model for each mobile robot. Second, a unified tracking error system between camera-objective visual servoing model and desired reference trajectory is introduced. Third, based on the neighbour rule and by using finite-time control method, continuous distributed cooperative finite-time tracking control laws are designed for each mobile robot with unknown camera parameters, where the communication topology among the multiple mobile robots is assumed to be a directed graph. Rigorous proof shows that the group of mobile robots converges to the desired reference trajectory in finite time. Simulation example illustrates the effectiveness of our method.

  15. Cardiac autonomic control and complexity during sleep are preserved after chronic sleep restriction in healthy subjects.

    Science.gov (United States)

    Tobaldini, Eleonora; Covassin, Naima; Calvin, Andrew; Singh, Prachi; Bukartyk, Jan; Wang, Shiang; Montano, Nicola; Somers, Virend K

    2017-04-01

    Acute sleep deprivation (SD) alters cardiovascular autonomic control (CAC) and is associated with an increased risk of cardiovascular disorders. However, the effects of partial SD on CAC are unclear. Thus, we aimed to investigate the effects of partial SD on CAC during sleep. We randomized seventeen healthy subjects to a restriction group (RES, n = 8, subjects slept two-thirds of normal sleep time based on individual habitual sleep duration for 8 days and 8 nights) or a Control group (CON, n = 9, subjects were allowed to sleep their usual sleep time). Attended polysomnographic (PSG) studies were performed every night; a subset of them was selected for the analysis at baseline (day 3-D3), the first night after sleep restriction (day 5-D5), at the end of sleep restriction period (day 11-D11), and at the end of recovery phase (day 14-D14). We extracted electrocardiogram (ECG) and respiration from the PSG and divided into wakefulness (W), nonrapid eye movements (REM) sleep (N2 and N3) and REM sleep. CAC was evaluated by means of linear spectral analysis, nonlinear symbolic analysis and complexity indexes. In both RES and CON groups, sympathetic modulation decreased and parasympathetic modulation increased during N2 and N3 compared to W and REM at D3, D5, D11, D14. Complexity analysis revealed a reduction in complexity during REM compared to NREM sleep in both DEP and CON After 8 days of moderate SD, cardiac autonomic dynamics, characterized by decreased sympathetic, and increased parasympathetic modulation, and higher cardiac complexity during NREM sleep, compared to W and REM, are preserved. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  16. Attentional control and subjective executive function in treatment-naive adults with Attention Deficit Hyperactivity Disorder.

    Directory of Open Access Journals (Sweden)

    Venke Arntsberg Grane

    Full Text Available We investigated performance-derived measures of executive control, and their relationship with self- and informant reported executive functions in everyday life, in treatment-naive adults with newly diagnosed Attention Deficit Hyperactivity Disorder (ADHD; n = 36 and in healthy controls (n = 35. Sustained attentional control and response inhibition were examined with the Test of Variables of Attention (T.O.V.A.. Delayed responses, increased reaction time variability, and higher omission error rate to Go signals in ADHD patients relative to controls indicated fluctuating levels of attention in the patients. Furthermore, an increment in NoGo commission errors when Go stimuli increased relative to NoGo stimuli suggests reduced inhibition of task-irrelevant stimuli in conditions demanding frequent responding. The ADHD group reported significantly more cognitive and behavioral executive problems than the control group on the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A. There were overall not strong associations between task performance and ratings of everyday executive function. However, for the ADHD group, T.O.V.A. omission errors predicted self-reported difficulties on the Organization of Materials scale, and commission errors predicted informant reported difficulties on the same scale. Although ADHD patients endorsed more symptoms of depression and anxiety on the Achenbach System of Empirically Based Assessment (ASEBA than controls, ASEBA scores were not significantly associated with T.O.V.A. performance scores. Altogether, the results indicate multifaceted alteration of attentional control in adult ADHD, and accompanying subjective difficulties with several aspects of executive function in everyday living. The relationships between the two sets of data were modest, indicating that the measures represent non-redundant features of adult ADHD.

  17. Longitudinal changes in ultrasound measurements: a parallel study in subjects with genetic disorders and healthy controls.

    Science.gov (United States)

    Halaba, Zenon; Pyrkosz, Antoni; Adamczyk, Piotr; Drozdzowska, Bogna; Pluskiewicz, Wojciech

    2006-03-01

    Disturbances in skeletal status in subjects with genetic disorder may increase their fracture risk. The aim of the study was longitudinal observation of phalangeal speed of sound changes across the bone over a period of 2 y in 24 patients (14 boys and 10 girls, mean age 9.63 +/- 1.8 y.) and 24 age-matched healthy controls (14 boys and 10 girls, mean age 9.65 +/- 1.71 y.). Weight and height did not differ between patients and controls at baseline and follow-up. Patients with the following disorders were evaluated: 7 with Down syndrome, 6 nonspecific mental retardations of unknown etiology, 5 Martin-Bell syndrome and 6 with other diseases. In patients and controls, no factors potentially influencing bone metabolism (except for genetic disorder) were present. Bone status was assessed by quantitative ultrasound at hand phalanges using DBM Sonic 1200 (IGEA, Carpi, Italy), which measures amplitude-dependent speed of sound (Ad-SoS [m/s]). At baseline, Ad-SoS and Z-score were significantly lower in patients than in controls (1892 +/- 51 m/s versus 1936 +/- 43 m/s, p Z-score increased significantly in patients (1892 +/- 51 m/s to 1934 +/- 48 m/s, p Z-Score were significantly lower in patients (p Z-score weight did not differ between patients and control, and height increased more in controls (13.2 +/- 2.8 cm versus 11.4 +/- 5.9 cm, p over a period of observation. In conclusion, despite comparable improvement in measured ultrasound parameter in patients and controls observed over a study duration, the difference between them remained stable.

  18. Effects of the AMPA antagonist ZK 200775 on visual function: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Richard Bergholz

    Full Text Available BACKGROUND: ZK 200775 is an antagonist at the alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA receptor and had earned attention as a possible neuroprotective agent in cerebral ischemia. Probands receiving the agent within phase I trials reported on an alteration of visual perception. In this trial, the effects of ZK 200775 on the visual system were analyzed in detail. METHODOLOGY: In a randomised controlled trial we examined eyes and vision before and after the intravenous administration of two different doses of ZK 200775 and placebo. There were 3 groups of 6 probands each: Group 1 recieved 0.03 mg/kg/h, group 2 0.75 mg/kg/h of ZK 200775, the control group received 0.9% sodium chloride solution. Probands were healthy males aged between 57 and 69 years. The following methods were applied: clinical examination, visual acuity, ophthalmoscopy, colour vision, rod absolute threshold, central visual field, pattern-reversal visual evoked potentials (pVEP, ON-OFF and full-field electroretinogram (ERG. PRINCIPAL FINDINGS: No effect of ZK 200775 was seen on eye position or motility, stereopsis, pupillary function or central visual field testing. Visual acuity and dark vision deteriorated significantly in both treated groups. Color vision was most remarkably impaired. The dark-adapted ERG revealed a reduction of oscillatory potentials (OP and partly of the a- and b-wave, furthermore an alteration of b-wave morphology and an insignificantly elevated b/a-ratio. Cone-ERG modalities showed decreased amplitudes and delayed implicit times. In the ON-OFF ERG the ON-answer amplitudes increased whereas the peak times of the OFF-answer were reduced. The pattern VEP exhibited lower amplitudes and prolonged peak times. CONCLUSIONS: The AMPA receptor blockade led to a strong impairment of typical OFF-pathway functions like color vision and the cone ERG. On the other hand the ON-pathway as measured by dark vision and the scotopic ERG was affected as well

  19. Effects of the AMPA antagonist ZK 200775 on visual function: a randomized controlled trial.

    Science.gov (United States)

    Bergholz, Richard; Staks, Thomas; Rüther, Klaus

    2010-08-12

    ZK 200775 is an antagonist at the alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor and had earned attention as a possible neuroprotective agent in cerebral ischemia. Probands receiving the agent within phase I trials reported on an alteration of visual perception. In this trial, the effects of ZK 200775 on the visual system were analyzed in detail. In a randomised controlled trial we examined eyes and vision before and after the intravenous administration of two different doses of ZK 200775 and placebo. There were 3 groups of 6 probands each: Group 1 recieved 0.03 mg/kg/h, group 2 0.75 mg/kg/h of ZK 200775, the control group received 0.9% sodium chloride solution. Probands were healthy males aged between 57 and 69 years. The following methods were applied: clinical examination, visual acuity, ophthalmoscopy, colour vision, rod absolute threshold, central visual field, pattern-reversal visual evoked potentials (pVEP), ON-OFF and full-field electroretinogram (ERG). No effect of ZK 200775 was seen on eye position or motility, stereopsis, pupillary function or central visual field testing. Visual acuity and dark vision deteriorated significantly in both treated groups. Color vision was most remarkably impaired. The dark-adapted ERG revealed a reduction of oscillatory potentials (OP) and partly of the a- and b-wave, furthermore an alteration of b-wave morphology and an insignificantly elevated b/a-ratio. Cone-ERG modalities showed decreased amplitudes and delayed implicit times. In the ON-OFF ERG the ON-answer amplitudes increased whereas the peak times of the OFF-answer were reduced. The pattern VEP exhibited lower amplitudes and prolonged peak times. The AMPA receptor blockade led to a strong impairment of typical OFF-pathway functions like color vision and the cone ERG. On the other hand the ON-pathway as measured by dark vision and the scotopic ERG was affected as well. This further elucidates the interdependence of both pathways. Clinical

  20. Adaptive Visual Re-Weighting in Children’s Postural Control

    Science.gov (United States)

    Polastri, Paula F.; Barela, José A.

    2013-01-01

    This study investigated how children’s postural control adapts to changes in the visual environment and whether they use previous experience to adjust postural responses to following expositions. Four-, eight-, and twelve-year-old children (10 in each group) and 10 young adults stood upright inside of a moving room during eight trials each lasting one-minute. In the first trial, the room was stationary. In the following seven trials, the room oscillated at 0.2 Hz, amplitude of 0.5 cm, with the exception of the fifth trial, in which the room oscillated with amplitude of 3.2 cm. Body sway responses of young adults and older children down-weighted more to the increased visual stimulus amplitude when compared to younger children. In addition, four- and eight-year-old children quickly up-weighted body responses to visual stimulus in the subsequent two trials after the high amplitude trial. Sway variability decreased with age and was greatest during the high-amplitude trial. These results indicate that four year olds have already developed the adaptive capability to quickly down-weight visual influences. However, the increased gain values and residual variability observed for the younger children suggest that they have not fully calibrated their adaptive response to that of the young adults tested. Moreover, younger children do not carry over their previous experience from the sensorial environment to adapt to future changes. PMID:24324766

  1. Knowledge Discovery for Smart Grid Operation, Control, and Situation Awareness -- A Big Data Visualization Platform

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yi; Jiang, Huaiguang; Zhang, Yingchen; Zhang, Jun Jason; Gao, Tianlu; Muljadi, Eduard

    2016-11-21

    In this paper, a big data visualization platform is designed to discover the hidden useful knowledge for smart grid (SG) operation, control and situation awareness. The spawn of smart sensors at both grid side and customer side can provide large volume of heterogeneous data that collect information in all time spectrums. Extracting useful knowledge from this big-data poll is still challenging. In this paper, the Apache Spark, an open source cluster computing framework, is used to process the big-data to effectively discover the hidden knowledge. A high-speed communication architecture utilizing the Open System Interconnection (OSI) model is designed to transmit the data to a visualization platform. This visualization platform uses Google Earth, a global geographic information system (GIS) to link the geological information with the SG knowledge and visualize the information in user defined fashion. The University of Denver's campus grid is used as a SG test bench and several demonstrations are presented for the proposed platform.

  2. Analyses of aerodynamic characteristics of the oropharynx applying CBCT: obstructive sleep apnea patients versus control subjects.

    Science.gov (United States)

    Chen, Hui; Li, Yingguang; Reiber, Johan Hc; de Lange, Jan; Tu, Shengxian; van der Stelt, Paul; Lobbezoo, Frank; Aarab, Ghizlane

    2018-02-01

    To determine the most relevant aerodynamic characteristic of the oropharynx related to the collapse of the upper airway in obstructive sleep apnea (OSA) patients; and to determine the correlation between the most relevant aerodynamic characteristic(s) of the oropharynx and anatomical characteristics of the oropharynx in OSA patients. 31 mild to moderate OSA patients (mean ± SD age = 43.5 ± 9.7 years) and 13 control subjects (mean ± SD age = 48.5 ± 16.2 years) were included in this prospective study. The diagnosis of OSA patients was based on an overnight polysomnographic recording. To exclude the presence of OSA in the control subjects, they were asked to fill out a validated questionnaire to determine the risk of OSA. NewTom5G cone beam CT (CBCT) scans were obtained from both OSA patients and control subjects. Computational models of the oropharynx were reconstructed based on CBCT images. The aerodynamic characteristics of the oropharynx were calculated based on these computational models. Pearson correlation analysis was used to analyse the correlation between the most relevant aerodynamic characteristic(s) and anatomical characteristics of the oropharynx in OSA patients. Compared with controls, the airway resistance during expiration (R ex ) of the OSA patients was significantly higher (p = 0.04). There was a significant negative correlation between R ex and the minimum cross-sectional area (CSA min ) of the oropharynx (r = -0.41, p = 0.02), and between R ex and the volume of the oropharynx (r = -0.48, p = 0.01) in OSA patients. After excluding an outlier, there is only significant correlation between R ex and the CSA min of the oropharynx (r = -0.45, p = 0.01). Within the limitations of this study, we concluded that the most relevant aerodynamic characteristic of the oropharynx in the collapse of the upper airway in OSA patients is R ex . Therefore, the repetitive collapse of the upper airway in OSA patients may be explained by a high R ex , which is

  3. Cannabis use and anticipatory pleasure as reported by subjects with early psychosis and community controls.

    Science.gov (United States)

    Cassidy, Clifford M; Lepage, Martin; Harvey, Philippe-Olivier; Malla, Ashok

    2012-05-01

    There is evidence of decreased pleasure and deficits in the anticipation of reward in both psychotic illness and drug addiction. Individuals with low anticipatory pleasure may preferentially engage in behaviours associated with immediate reward such as cannabis use. Ninety-one psychosis patients and 91 controls without history of psychosis were administered the Temporal Experience of Pleasure Scale (TEPS), a self report which measures anticipatory and consummatory pleasure. Cannabis use diagnosis was assessed using the Structured Clinical Interview for DSM IV (SCID). Subjects reported the frequency of cannabis consumption and time since last use. Patients did not show a significant deficit in anticipatory or consummatory pleasure compared to controls; however, patients with an active cannabis-use disorder tended to have lower consummatory pleasure than controls with active cannabis disorder (ppleasure compared to those who had a lifetime cannabis diagnosis but were able to maintain abstinence (F(1,60)=5.6, p=.021). Frequency of cannabis use was negatively correlated to anticipatory and consummatory pleasure (Pearson R=-.46, -.48 respectively) in 37 patients currently using cannabis but not in 46 cannabis-using controls (partial R=-.04, -.07 respectively). Anticipatory pleasure may not be decreased in early psychosis patients. Lower hedonic response may be associated with persistent, heavy cannabis use in patients in the early phase of psychotic disorders. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Comparison of the traditional paper visual analogue scale questionnaire with an Apple Newton electronic appetite rating system (EARS) in free living subjects feeding ad libitum.

    Science.gov (United States)

    Stratton, R J; Stubbs, R J; Hughes, D; King, N; Blundell, J E; Elia, M

    1998-10-01

    Assessing the value of a newly developed electronic visual analogue scale questionnaire (Apple Newton Message Pad) with the traditional paper method for appetite rating. In a random, crossover design, subjects completed both electronic and paper questionnaires to compare results obtained by the two methods; individual methods were completed consecutively to assess test-retest reliability; preference was established using a questionnaire. Healthy, free-living adults were studied for comparison of methods (n = 12), test-retest reliability (n = 8) and preference (n = 13). Visual analogue scales were completed each waking hour to assess appetite. Preference was assessed after both methods were completed. There was no significant difference in the hourly results obtained by the paper and electronic methods for 'desire to eat', 'how much can you eat now', 'urge to eat' and 'preoccupation with thoughts of food'. Small differences in 'hunger' and 'fullness' ratings were noted (approximately 5% mean difference between methods, P Apple Newton questionnaire is as sensitive and reliable as the paper method, has the advantage that it automatically records the time of data acquisition and data collection and processing are more efficient for the researcher. The two methods should not be used interchangeably.

  5. Effect of Travel Speed on the Visual Control of Steering Toward a Goal.

    Science.gov (United States)

    Chen, Rongrong; Niehorster, Diederick C; Li, Li

    2017-08-17

    Previous studies have proposed that people can use visual cues such as the instantaneous direction (i.e., heading) or future path trajectory of travel specified by optic flow or target visual direction in egocentric space to steer or walk toward a goal. In the current study, we examined what visual cues people use to guide their goal-oriented locomotion and whether their reliance on such visual cues changes as travel speed increases. We presented participants with optic flow displays that simulated their self-motion toward a target at various travel speeds under two viewing conditions in which we made target egocentric direction available or unavailable for steering. We found that for both viewing conditions, participants did not steer along a curved path toward the target such that the actual and the required path curvature to reach the target would converge when approaching the target. At higher travel speeds, participants showed a faster and larger reduction in target-heading angle and more accurate and precise steady-state control of aligning their heading specified by optic flow with the target. These findings support the claim that people use heading and target egocentric direction but not path for goal-oriented locomotion control, and their reliance on heading increases at higher travel speeds. The increased reliance on heading for goal-oriented locomotion control could be due to an increased reliability in perceiving heading from optic flow as the magnitude of flow increases with travel speed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. Gastrointestinal tolerance of low FODMAP oral nutrition supplements in healthy human subjects: a randomized controlled trial.

    Science.gov (United States)

    Erickson, Jennifer; Korczak, Renee; Wang, Qi; Slavin, Joanne

    2017-05-25

    There has been increasing interest in utilizing a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) for the treatment of irritable bowel syndrome (IBS), a functional gastrointestinal disease. While studies have indicated that this diet can be effective at symptom reduction, it is a restrictive diet and patients may find it challenging to find low FODMAP products to meet their nutrient needs. The primary objective of this study was to assess the gastrointestinal (GI) tolerance of three low FODMAP oral nutrition supplements (ONS) in healthy adults. A double-blind randomized controlled crossover study was conducted in 21 healthy adults (19-32 years). Fasted subjects consumed one of four treatments at each visit, with a one week wash out period between visits. Each participant received all treatments. Treatments included three low FODMAP ONS formulas (A, B, and C) as well as a positive control consisting of 5 g fructooligosaccharides (FOS) mixed in lactose-free milk. Breath hydrogen was measured at baseline, 1, 2, 3, and 4 h post treatment consumption. Subjective GI symptom questionnaires were completed at baseline, 0.5, 1, 1.5, 2, 3, 4, 12, 24 and 48 h following treatment consumption. Mean breath hydrogen concentrations and baseline corrected area under the curve for both breath hydrogen and GI symptoms were analyzed and compared between treatments. Significance was determined at P FODMAP ONS beverages at 3 and 4 h after consumption. There were no differences in GI symptom response between treatments. All treatments were well tolerated in healthy participants. The low FODMAP formulas resulted in a lower breath hydrogen response compared to the positive control, and may be better tolerated in individuals with IBS. More research should be conducted to better understand the GI tolerance of low FODMAP ONS in individuals with IBS. The protocol for this study was registered on ClinicalTrials.gov in January 2016 (Clinical

  7. Population pharmacokinetic modeling of glibenclamide in poorly controlled South African type 2 diabetic subjects.

    Science.gov (United States)

    Rambiritch, Virendra; Naidoo, Poobalan; Maharaj, Breminand; Pillai, Goonaseelan

    2016-01-01

    The aim of this study was to describe the pharmacokinetics (PK) of glibenclamide in poorly controlled South African type 2 diabetic subjects using noncompartmental and model-based methods. A total of 24 subjects with type 2 diabetes were administered increasing doses (0 mg/d, 2.5 mg/d, 5 mg/d, 10 mg/d, and 20 mg/d) of glibenclamide daily at 2-week intervals. Plasma glibenclamide, glucose, and insulin determinations were performed. Blood sampling times were 0 minute, 30 minutes, 60 minutes, 90 minutes, and 120 minutes (post breakfast sampling) and 240 minutes, 270 minutes, 300 minutes, 330 minutes, 360 minutes, and 420 minutes (post lunch sampling) on days 14, 28, 42, 56, and 70 for doses of 0 mg, 2.5 mg, 5.0 mg, 10 mg, and 20 mg, respectively. Blood sampling was performed after the steady state was reached. A total of 24 individuals in the data set contributed to a total of 841 observation records. The PK was analyzed using noncompartmental analysis methods, which were implemented in WinNonLin(®), and population PK analysis using NONMEM(®). Glibenclamide concentration data were log transformed prior to fitting. A two-compartmental disposition model was selected after evaluating one-, two-, and three-compartmental models to describe the time course of glibenclamide plasma concentration data. The one-compartment model adequately described the data; however, the two-compartment model provided a better fit. The three-compartment model failed to achieve successful convergence. A more complex model, to account for enterohepatic recirculation that was observed in the data, was unsuccessful. In South African diabetic subjects, glibenclamide demonstrates linear PK and was best described by a two-compartmental model. Except for the absorption rate constant, the other PK parameters reported in this study are comparable to those reported in the scientific literature. The study is limited by the small study sample size and inclusion of poorly controlled type 2 diabetic

  8. Population pharmacokinetic modeling of glibenclamide in poorly controlled South African type 2 diabetic subjects

    Directory of Open Access Journals (Sweden)

    Rambiritch V

    2016-07-01

    Full Text Available Virendra Rambiritch,1 Poobalan Naidoo,2 Breminand Maharaj,1 Goonaseelan Pillai3 1University of KwaZulu-Natal, Durban, 2Department of Internal Medicine, RK Khan Regional Hospital, Chatsworth, South Africa; 3Novartis Pharma AG, Basel, Switzerland Aim: The aim of this study was to describe the pharmacokinetics (PK of glibenclamide in poorly controlled South African type 2 diabetic subjects using noncompartmental and model-based methods. Methods: A total of 24 subjects with type 2 diabetes were administered increasing doses (0 mg/d, 2.5 mg/d, 5 mg/d, 10 mg/d, and 20 mg/d of glibenclamide daily at 2-week intervals. Plasma glibenclamide, glucose, and insulin determinations were performed. Blood sampling times were 0 minute, 30 minutes, 60 minutes, 90 minutes, and 120 minutes (post breakfast sampling and 240 minutes, 270 minutes, 300 minutes, 330 minutes, 360 minutes, and 420 minutes (post lunch sampling on days 14, 28, 42, 56, and 70 for doses of 0 mg, 2.5 mg, 5.0 mg, 10 mg, and 20 mg, respectively. Blood sampling was performed after the steady state was reached.  A total of 24 individuals in the data set contributed to a total of 841 observation records. The PK was analyzed using noncompartmental analysis methods, which were implemented in WinNonLin®, and population PK analysis using NONMEM®. Glibenclamide concentration data were log transformed prior to fitting. Results: A two-compartmental disposition model was selected after evaluating one-, two-, and three-compartmental models to describe the time course of glibenclamide plasma concentration data. The one-compartment model adequately described the data; however, the two-compartment model provided a better fit. The three-compartment model failed to achieve successful convergence. A more complex model, to account for enterohepatic recirculation that was observed in the data, was unsuccessful. Conclusion: In South African diabetic subjects, glibenclamide demonstrates linear PK and was best

  9. The effects of alcohol on the driver's visual information processing.

    Science.gov (United States)

    1980-09-01

    Twenty-seven male subjects were tested in a driving simulator to study the effects of alcohol on visual information processing and allocation of attention. Subjects were required to control heading angle, maintain a constant speed, search for critica...

  10. In-human subject-specific evaluation of a control-theoretic plasma volume regulation model.

    Science.gov (United States)

    Bighamian, Ramin; Kinsky, Michael; Kramer, George; Hahn, Jin-Oh

    2017-12-01

    The goal of this study was to conduct a subject-specific evaluation of a control-theoretic plasma volume regulation model in humans. We employed a set of clinical data collected from nine human subjects receiving fluid bolus with and without co-administration of an inotrope agent, including fluid infusion rate, plasma volume, and urine output. Once fitted to the data associated with each subject, the model accurately reproduced the fractional plasma volume change responses in all subjects: the error between actual versus model-reproduced fractional plasma volume change responses was only 1.4 ± 1.6% and 1.2 ± 0.3% of the average fractional plasma volume change responses in the absence and presence of inotrope co-administration. In addition, the model parameters determined by the subject-specific fitting assumed physiologically plausible values: (i) initial plasma volume was estimated to be 36 ± 11 mL/kg and 37 ± 10 mL/kg in the absence and presence of inotrope infusion, respectively, which was comparable to its actual counterpart of 37 ± 4 mL/kg and 43 ± 6 mL/kg; (ii) volume distribution ratio, specifying the ratio with which the inputted fluid is distributed in the intra- and extra-vascular spaces, was estimated to be 3.5 ± 2.4 and 1.9 ± 0.5 in the absence and presence of inotrope infusion, respectively, which accorded with the experimental observation that inotrope could enhance plasma volume expansion in response to fluid infusion. We concluded that the model was equipped with the ability to reproduce plasma volume response to fluid infusion in humans with physiologically plausible model parameters, and its validity may persist even under co-administration of inotropic agents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. [Dietary habits, attitudes toward weight control, and subjective symptoms of fatigue in young women in Japan].

    Science.gov (United States)

    Osako, Mai; Takayama, Tomoko; Kira, Shohei

    2005-05-01

    This paper describes dietary habits and attitudes toward body weight control of college women in Japan and examines their relationships with subjective symptoms of fatigue. We also discuss strategies to promote better diets among young adults. Self-reported questionnaires were distributed to 286 young women aged 18 to 25 years; 275 of these were analyzed. The study found that more than half of the women were concerned about nutritional balance and calories. Yet thirty percent ate "a single-item meal (i.e., bread, rice bowl, noodles) two or more times a day," while roughly one half skipped breakfast "sometimes" or "always." A majority ate vegetables "almost never" and consumed instant foods, confectionery, or sugary drinks "almost daily." Subjective symptoms of fatigue were significantly correlated with a higher frequency of irregular meal-taking, single-item meals, between-meal snacking, missed breakfasts, non-vegetable diets, non-fruit diets, and instant foods and confectionery. About sixty percent of the women in the study considered their bodies to be "slightly fat or overweight" while 79.5% indicated a desire to "lose weight". On average, the participants' ideal BMI was 18.7 (+/- 1.2) while the ideal body weight was 47.2 (+/- 4.1) kg, approximately 4 kg under actual average body weight. Subjective symptoms of fatigue were stronger among women who considered themselves "slightly fat or overweight". Likewise, symptoms were stronger to the extent that a participant's ideal BMI was below her actual BMI. Many women in this study desired to lose weight although they were not overweight by objective measures. The study suggests that subjective symptoms of fatigue are not the result of individual dietary habits, but rather of a lifestyle that reach to series of dietary habits connected to subjective symptoms of fatigue. The study also confirms the importance both of encouraging young women not just to eat well but to lead lifestyles in which they do not skip meals and

  12. Hippocampal activation correlates with visual confrontation naming: fMRI findings in controls and patients with temporal lobe epilepsy.

    Science.gov (United States)

    Bonelli, Silvia B; Powell, Rob; Thompson, Pamela J; Yogarajah, Mahinda; Focke, Niels K; Stretton, Jason; Vollmar, Christian; Symms, Mark R; Price, Cathy J; Duncan, John S; Koepp, Matthias J

    2011-08-01

    In patients with left temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) decreased naming ability is common, suggesting a critical role for the medial left temporal lobe in this task. We investigated the integrity of language networks with functional MRI (fMRI) in controls and TLE patients. We performed an fMRI verbal fluency paradigm in 22 controls and 66 patients with unilateral mesial TLE (37 left HS, 29 right HS). Verbal fluency and naming ability were investigated as part of the standard presurgical neuropsychological assessment. Naming ability was assessed using a visual confrontation naming test. Left TLE patients had significantly lower naming scores than controls and those with right TLE. Right TLE patients performed less well than controls, but better than those with left TLE. Left TLE had significantly lower scores for verbal fluency than controls. In controls and right TLE, left hippocampal activation during the verbal fluency task was significantly correlated with naming, characterised by higher scores in subjects with greater hippocampal fMRI activation. In left TLE no correlation with naming scores was seen in the left hippocampus, but there was a significant correlation in the left middle and inferior frontal gyri, not observed in controls and right TLE. In left and right TLE, out of scanner verbal fluency scores significantly correlated with fMRI activation for verbal fluency in the left middle and inferior frontal gyri. Good confrontation naming ability depends on the integrity of the hippocampus and the connecting fronto-temporal networks. Functional MRI activation in the left hippocampus during verbal fluency is associated with naming function in healthy controls and patients with right TLE. In left TLE, there was evidence of involvement of the left frontal lobe when naming was more proficient, most likely reflecting a compensatory response due to the ongoing epileptic activity and/or underlying pathology. Copyright © 2011 Elsevier

  13. Is selective mutism associated with deficits in memory span and visual memory?: An exploratory case-control study.

    Science.gov (United States)

    Kristensen, Hanne; Oerbeck, Beate

    2006-01-01

    Our main aim in this study was to explore the association between selective mutism (SM) and aspects of nonverbal cognition such as visual memory span and visual memory. Auditory-verbal memory span was also examined. The etiology of SM is unclear, and it probably represents a heterogeneous condition. SM is associated with language impairment, but nonspecific neurodevelopmental factors, including motor problems, are also reported in SM without language impairment. Furthermore, SM is described in Asperger's syndrome. Studies on nonverbal cognition in SM thus merit further investigation. Neuropsychological tests were administered to a clinical sample of 32 children and adolescents with SM (ages 6-17 years, 14 boys and 18 girls) and 62 nonreferred controls matched for age, gender, and socioeconomic status. We used independent t-tests to compare groups with regard to auditory-verbal memory span, visual memory span, and visual memory (Benton Visual Retention Test), and employed linear regression analysis to study the impact of SM on visual memory, controlling for IQ and measures of language and motor function. The SM group differed from controls on auditory-verbal memory span but not on visual memory span. Controlled for IQ, language, and motor function, the SM group did not differ from controls on visual memory. Motor function was the strongest predictor of visual memory performance. SM does not appear to be associated with deficits in visual memory span or visual memory. The reduced auditory-verbal memory span supports the association between SM and language impairment. More comprehensive neuropsychological studies are needed.

  14. How to avoid the `invisible gorilla' in aluminum smelting process control: Visual guidelines

    Science.gov (United States)

    Gao, Yashuang; Taylor, Mark P.; Chen, John J. J.; Hautus, Michael J.

    2011-08-01

    Over the last three decades, process control in aluminum smelters has improved significantly as it is the biggest leverage for cost and energy reduction in production and product quality improvement, as well as for meeting environmental compliance. The implementation of computerized automatic control systems two decades ago was a step change in improvement in the state of the art of process control. However, the complex and dynamic nature of the process requires human monitoring, diagnosis, and intervention from time to time. This study investigates the use of the supervisory screen of the control system of a smelter, as well as the effectiveness of visual guidelines to help the operators to identify process abnormalities. The results show that visual guidelines such as voltage patterns which are used as a reference improve the performance of the operators. Detection time and falsealarm rates were reduced in addition to increasing detection sensitivities. It is proposed that a higher level of human and system interaction would improve the overall performance process control.

  15. The effect of dry needling on the radiating pain in subjects with discogenic low-back pain: A randomized control trial.

    Science.gov (United States)

    Mahmoudzadeh, Ashraf; Rezaeian, Zahra Sadat; Karimi, Abdolkarim; Dommerholt, Jan

    2016-01-01

    Disk herniation is the most common cause of radiating low back pain (LBP) in subjects under 60 years of age. The present study aims to compare the effect of dry needling (DN) and a standard conservative approach on the pain and function in subjects with discogenic radiating LBP. Fifty-eight subjects with discogenic radicular LBP were screened and randomized into control (Standard physical therapy, n = 29) and experimental group (Standard physical therapy and DN, n = 29). Radiating pain intensity and disability were measured using visual analog scale (VAS) and Oswestry Disability indices at baseline, at the end of treatment and 2 months after the last intervention session. The changes in pain intensity and disability were studied using a 3 × 2 repeated measures analysis of variance considering time as the within-subject factor and group as the between-subject. Pain intensity and disability scores decreased significantly in both experimental and control groups (experimental group: VAS = 37.24, Oswestry Disability Index [ODI] =28.48, control group: VAS = 45.5, ODI = 32.96), following the intervention. The change continued during the follow-up period (P < 0.001 for all comparisons). Pain and disability improvement, however, were more significant in experimental group, both in post intervention (experimental group: VAS = 25.17, ODI = 22.17, control group: VAS = 42.4, ODI = 30.27) (P = 0.05 and P = 0.03, respectively) and follow-up measures (P = 0.006 and P = 0.002, respectively). Both intervention strategies seem to significantly improve pain and disability immediately following intervention, where the improvement continued during 2 months after the last active intervention. Therefore, supplementary DN application may enhance the effect of the standard intervention considerably.

  16. The effect of dry needling on the radiating pain in subjects with discogenic low-back pain: A randomized control trial

    Directory of Open Access Journals (Sweden)

    Ashraf Mahmoudzadeh

    2016-01-01

    Full Text Available Background: Disk herniation is the most common cause of radiating low back pain (LBP in subjects under 60 years of age. The present study aims to compare the effect of dry needling (DN and a standard conservative approach on the pain and function in subjects with discogenic radiating LBP. Materials and Methods: Fifty-eight subjects with discogenic radicular LBP were screened and randomized into control (Standard physical therapy, n = 29 and experimental group (Standard physical therapy and DN, n = 29. Radiating pain intensity and disability were measured using visual analog scale (VAS and Oswestry Disability indices at baseline, at the end of treatment and 2 months after the last intervention session. The changes in pain intensity and disability were studied using a 3 × 2 repeated measures analysis of variance considering time as the within-subject factor and group as the between-subject. Results: Pain intensity and disability scores decreased significantly in both experimental and control groups (experimental group: VAS = 37.24, Oswestry Disability Index [ODI] =28.48, control group: VAS = 45.5, ODI = 32.96, following the intervention. The change continued during the follow-up period (P < 0.001 for all comparisons. Pain and disability improvement, however, were more significant in experimental group, both in post intervention (experimental group: VAS = 25.17, ODI = 22.17, control group: VAS = 42.4, ODI = 30.27 (P = 0.05 and P = 0.03, respectively and follow-up measures (P = 0.006 and P = 0.002, respectively. Conclusion: Both intervention strategies seem to significantly improve pain and disability immediately following intervention, where the improvement continued during 2 months after the last active intervention. Therefore, supplementary DN application may enhance the effect of the standard intervention considerably.

  17. Visual working memory capacity increases between ages 3 and 8 years, controlling for gains in attention, perception, and executive control.

    Science.gov (United States)

    Pailian, Hrag; Libertus, Melissa E; Feigenson, Lisa; Halberda, Justin

    2016-08-01

    Research in adults has aimed to characterize constraints on the capacity of Visual Working Memory (VWM), in part because of the system's broader impacts throughout cognition. However, less is known about how VWM develops in childhood. Existing work has reached conflicting conclusions as to whether VWM storage capacity increases after infancy, and if so, when and by how much. One challenge is that previous studies did not control for developmental changes in attention and executive processing, which also may undergo improvement. We investigated the development of VWM storage capacity in children from 3 to 8 years of age, and in adults, while controlling for developmental change in exogenous and endogenous attention and executive control. Our results reveal that, when controlling for improvements in these abilities, VWM storage capacity increases across development and approaches adult-like levels between ages 6 and 8 years. More generally, this work highlights the value of estimating working memory, attention, perception, and decision-making components together.

  18. Target-nontarget similarity decreases search efficiency and increases stimulus-driven control in visual search.

    Science.gov (United States)

    Barras, Caroline; Kerzel, Dirk

    2017-10-01

    Some points of criticism against the idea that attentional selection is controlled by bottom-up processing were dispelled by the attentional window account. The attentional window account claims that saliency computations during visual search are only performed for stimuli inside the attentional window. Therefore, a small attentional window may avoid attentional capture by salient distractors because it is likely that the salient distractor is located outside the window. In contrast, a large attentional window increases the chances of attentional capture by a salient distractor. Large and small attentional windows have been associated with efficient (parallel) and inefficient (serial) search, respectively. We compared the effect of a salient color singleton on visual search for a shape singleton during efficient and inefficient search. To vary search efficiency, the nontarget shapes were either similar or dissimilar with respect to the shape singleton. We found that interference from the color singleton was larger with inefficient than efficient search, which contradicts the attentional window account. While inconsistent with the attentional window account, our results are predicted by computational models of visual search. Because of target-nontarget similarity, the target was less salient with inefficient than efficient search. Consequently, the relative saliency of the color distractor was higher with inefficient than with efficient search. Accordingly, stronger attentional capture resulted. Overall, the present results show that bottom-up control by stimulus saliency is stronger when search is difficult, which is inconsistent with the attentional window account.

  19. The magnitude of the effect of calf muscles fatigue on postural control during bipedal quiet standing with vision depends on the eye-visual target distance.

    Science.gov (United States)

    Vuillerme, Nicolas; Burdet, Cyril; Isableu, Brice; Demetz, Sylvain

    2006-10-01

    The purpose of the present experiment was to investigate whether, with vision, the magnitude of the effect of calf muscles fatigue on postural control during bipedal quiet standing depends on the eye-visual target distance. Twelve young university students were asked to stand upright as immobile as possible in three visual conditions (No vision, Vision 1m and Vision 4m) executed in two conditions of No fatigue and Fatigue of the calf muscles. Centre of foot pressure displacements were recorded using a force platform. Similar increased variances of the centre of foot pressure displacements were observed in the fatigue relative to the No fatigue condition for both the No vision and Vision 4m conditions. Interestingly, in the vision 1m condition, fatigue yielded: (1) a similar increased variance of the centre of foot pressure displacements to those observed in the No vision and Vision 4m conditions along the medio-lateral axis and (2) a weaker destabilising effect relative to the No vision and Vision 4m conditions along the antero-posterior axis. These results evidence that the ability to use visual information for postural control during bipedal quiet standing following calf muscles fatigue is dependent on the eye-visual target distance. More largely, in the context of the multisensory control of balance, the present findings suggest that the efficiency of the sensory reweighting of visual sensory cues as the neuro-muscular constraints acting on the subject change is critically linked with the quality of the information the visual system obtains.

  20. Chaos in balance: non-linear measures of postural control predict individual variations in visual illusions of motion.

    Directory of Open Access Journals (Sweden)

    Deborah Apthorp

    Full Text Available Visually-induced illusions of self-motion (vection can be compelling for some people, but they are subject to large individual variations in strength. Do these variations depend, at least in part, on the extent to which people rely on vision to maintain their postural stability? We investigated by comparing physical posture measures to subjective vection ratings. Using a Bertec balance plate in a brightly-lit room, we measured 13 participants' excursions of the centre of foot pressure (CoP over a 60-second period with eyes open and with eyes closed during quiet stance. Subsequently, we collected vection strength ratings for large optic flow displays while seated, using both verbal ratings and online throttle measures. We also collected measures of postural sway (changes in anterior-posterior CoP in response to the same visual motion stimuli while standing on the plate. The magnitude of standing sway in response to expanding optic flow (in comparison to blank fixation periods was predictive of both verbal and throttle measures for seated vection. In addition, the ratio between eyes-open and eyes-closed CoP excursions during quiet stance (using the area of postural sway significantly predicted seated vection for both measures. Interestingly, these relationships were weaker for contracting optic flow displays, though these produced both stronger vection and more sway. Next we used a non-linear analysis (recurrence quantification analysis, RQA of the fluctuations in anterior-posterior position during quiet stance (both with eyes closed and eyes open; this was a much stronger predictor of seated vection for both expanding and contracting stimuli. Given the complex multisensory integration involved in postural control, our study adds to the growing evidence that non-linear measures drawn from complexity theory may provide a more informative measure of postural sway than the conventional linear measures.

  1. Oral reading fluency analysis in patients with Alzheimer disease and asymptomatic control subjects.

    Science.gov (United States)

    Martínez-Sánchez, F; Meilán, J J G; García-Sevilla, J; Carro, J; Arana, J M

    2013-01-01

    Many studies highlight that an impaired ability to communicate is one of the key clinical features of Alzheimer disease (AD). To study temporal organisation of speech in an oral reading task in patients with AD and in matched healthy controls using a semi-automatic method, and evaluate that method's ability to discriminate between the 2 groups. A test with an oral reading task was administered to 70 subjects, comprising 35 AD patients and 35 controls. Before speech samples were recorded, participants completed a battery of neuropsychological tests. There were no differences between groups with regard to age, sex, or educational level. All of the study variables showed impairment in the AD group. According to the results, AD patients' oral reading was marked by reduced speech and articulation rates, low effectiveness of phonation time, and increases in the number and proportion of pauses. Signal processing algorithms applied to reading fluency recordings were shown to be capable of differentiating between AD patients and controls with an accuracy of 80% (specificity 74.2%, sensitivity 77.1%) based on speech rate. Analysis of oral reading fluency may be useful as a tool for the objective study and quantification of speech deficits in AD. Copyright © 2012 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  2. Metallic elements in pulmonary biopsies from lung cancer and control subjects.

    Science.gov (United States)

    De Palma, Giuseppe; Goldoni, Matteo; Catalani, Simona; Carbognani, Paolo; Poli, Diana; Mozzoni, Paola; Acampa, Olga; Internullo, Eveline; Rusca, Michele; Apostoli, Pietro

    2008-01-01

    Occupational/environmental exposure to some metallic elements is a risk factor for the development of lung diseases, including lung cancer. We aimed at investigating the levels of arsenic, beryllium, cadmium, cobalt, chromium, nickel and lead in the lung tissue of patients affected by early stage non small cell lung cancer (NSCLC). A small number of patients without a diagnosis of lung cancer were also included as control group. Lung tissue biopsies were collected from 45 NSCLC patients (both cancerous and unaffected tissues) and 8 control subjects undergoing surgery. Patients were stratified for smoking habits, histopathology and cancer sites. Metallic elements were determined in dry tissue after digestion by means of ICP-MS. Cd, Ni and Pb levels were higher in unaffected than in control tissues (0.52 vs 0.18 microg/g dry, p elements, and particularly Cd, were influenced by smoking habits; Pb levels were higher in squamocellular carcinoma than adenocarcinomas; Ni distributed in the lungs in an inhomogeneous way. This study demonstrates that the unaffected lung tissue is more representative than the cancerous tissue of the pulmonary content of metallic elements. Tobacco smoke is a main factor affecting the concentration levels of Cd, Pb, and to a lesser extent Ni in the lung tissues of NSCLC patients. The role of past environmental-occupational exposures could not be fully elucidated, due to the limited sample size and the retrospective nature of the study.

  3. Visualization of flow separation and control by vortex generators on an single flap in landing configuration

    Directory of Open Access Journals (Sweden)

    Matějka Milan

    2012-04-01

    Full Text Available This paper focuses on a suppression of the flow separation, which occurs on a deflected flap, by means of vortex generators (VG's. An airfoil NACA 63A421 with a simple flap and vane-type vortex generators were used. The investigation was carried out by using experimental and numerical methods. The data from the numerical simulation of the flapped airfoil without VG's control were used for the vortex generator design. Two sizes, two different shapes and various spacing of the vortex generators were tested. The flow past the airfoil was visualized through three methods, namely tuft filaments technique, oil and thermo camera visualization. The experiments were performed in closed circuit wind tunnels with closed and open test sections. The lift curves for both cases without and with vortex generators were acquired for a lift coefficient improvement determination. The improvement was achieved for several cases by means all of the applied methods.

  4. Combining Dense Structure from Motion and Visual SLAM in a Behavior-Based Robot Control Architecture

    Directory of Open Access Journals (Sweden)

    Geert De Cubber

    2010-03-01

    Full Text Available In this paper, we present a control architecture for an intelligent outdoor mobile robot. This enables the robot to navigate in a complex, natural outdoor environment, relying on only a single on-board camera as sensory input. This is achieved through a twofold analysis of the visual data stream: a dense structure from motion algorithm calculates a depth map of the environment and a visual simultaneous localization and mapping algorithm builds a map of the surroundings using image features. This information enables a behavior-based robot motion and path planner to navigate the robot through the environment. In this paper, we show the theoretical aspects of setting up this architecture.

  5. Self-regulation and the extended now: controlling the self alters the subjective experience of time.

    Science.gov (United States)

    Vohs, Kathleen D; Schmeichel, Brandon J

    2003-08-01

    These studies investigated self-regulation and subjective experience of time from the perspective of the regulatory resource model. Studies 1-2 showed that participants who were instructed to regulate their emotions while viewing a film clip perceived that the film lasted longer than participants who did not regulate their emotions. In Study 3, participants provided time estimates during a resource-depleting or nondepleting task. Subsequent task persistence was measured. Time perceptions mediated the effect of initial self-regulation on subsequent self-regulated performance. In Study 4, participants performed either a resource-depleting or a nondepleting thought-listing task and then performed a different regulatorytask. Compared with nondepleted participants, depleted participants persisted less on the 2nd task but estimated that they had persisted longer. Subjective time estimates statistically accounted for reduced persistence after depletion. Together, results indicate people believe that self-regulatory endeavors last overly long, a belief that may result in abandonment of further self-control.

  6. [Intention, attitude, subjective norms and perception of control in Spanish adolescents about using Double Dutch].

    Science.gov (United States)

    Hernández, Oscar; Goulet, Céline; Lampron, Annie

    2005-09-01

    With adolescence, boys and girls reach their sexual maturity and initiate their sexual encounters. They very frequently adopt risk behaviors as they tend not to use any contraceptive methods. Today's trend in relation to contraceptive methods is to recommend the combined utilization of condom and pill. In comparison to other methods, this last one, known as the Double Dutch (DD) method, has the advantage of preventing pregnancy and STD's, at the same time it increases the efficiency of contraception. Using the Theory of Planned Behavior the purpose of the study was to measure the intention, attitude, subjective norm and perceived behavioral control towards the utilization of the DD method among 15-16 year-old Spanish students and to determine the relationships among these variables. The results indicate that adolescents show favorable intention, attitude and subjective norm toward the utilization of the DD method. They seem to be more worried about pregnancy prevention than about STDs'prevention. Parents seem to be the most important reference people for adolescents, followed by their friends; the results show that at this age, adolescents tend to take into consideration these reference people's opinion.

  7. Subjective quality of life of outpatients with diabetes: comparison with family caregivers' impressions and control group.

    Science.gov (United States)

    Awadalla, Abdel W; Ohaeri, Jude U; Tawfiq, Adel M; Al-Awadi, Shafika A

    2006-05-01

    There is a paucity of studies on comparison of quality of life (QOL) of type-1 and type-2 diabetes patients, and the impact of family caregivers' impressions on the QOL of patients. To assess the subjective QOL of Sudanese diabetics using the WHOQOL-Bref, compared with a general population sample; examine caregiver-patient concordance; and assess the variables that impact on QOL. The responses of 105 outpatients with type-1 diabetes and 136 with type-2 diabetes were compared with their family caregivers' impressions and 139 general population subjects. Patients were predominantly dissatisfied with their life circumstances. Type-1 diabetics had significantly lowest QOL scores, while the control group had highest scores. Having additional medical problems; having diminished sexual desire; and being young, unemployed and single were associated with poor QOL, but illness duration was not. Type-2 diabetics had lesser concordance with caregivers. The only predictor of patients' QOL was the caregivers' impression of patients' QOL. Caregivers' impression of patients' QOL impacted on outcome. Caregiver education is, therefore, important. The factors associated with QOL indicate a group that needs focused attention. The good QOL for type-2 and nonsignificance of illness duration encourage therapeutic optimism.

  8. High cardiac vagal control is related to better subjective and objective sleep quality

    Science.gov (United States)

    Werner, Gabriela G.; Ford, Brett Q.; Mauss, Iris B.; Schabus, Manuel; Blechert, Jens; Wilhelm, Frank H.

    2015-01-01

    Cardiac vagal control (CVC) has been linked to both physical and mental health. One critical aspect of health, that has not received much attention, is sleep. We hypothesized that adults with higher CVC – operationalized by high-frequency heart rate variability (HF-HRV) – will exhibit better sleep quality assessed both subjectively (i.e., with Pittsburgh Sleep Quality Index) and objectively (i.e., with polysomnography). HF-HRV was measured in 29 healthy young women during an extended neutral film clip. Participants then underwent full polysomnography to obtain objective measures of sleep quality and HF-HRV during a night of sleep. As expected, higher resting HF-HRV was associated with higher subjective and objective sleep quality (i.e., shorter sleep latency and fewer arousals). HF-HRV during sleep (overall or separated by sleep phases) showed less consistent relationships with sleep quality. These findings indicate that high waking CVC may be a key predictor of healthy sleep. PMID:25709072

  9. Effects of the "affectionless control" parenting style on personality traits in healthy subjects.

    Science.gov (United States)

    Otani, Koichi; Suzuki, Akihito; Oshino, Shingo; Ishii, Genki; Matsumoto, Yoshihiko

    2009-01-30

    The effects of the affectionless control (AC) parenting style on personality traits were studied in 414 Japanese healthy subjects. Perceived parental rearing was assessed by the Parental Bonding Instrument, which comprises care and protection factors, and personality traits were assessed by the Temperament and Character Inventory, which has seven dimensions. Parental rearing was classified into four types, i.e., optimal parenting (high care/low protection), affectionate constraint (high care/high protection), neglectful parenting (low care/low protection), and AC (low care/high protection). Males with maternal AC showed significantly higher harm avoidance (HA) scores and lower scores of persistence and cooperativeness than those with maternal optimal parenting. Females with maternal AC showed significantly higher HA scores and lower self-directedness scores than those with maternal optimal parenting. Paternal AC was not significantly related to any personality score. In females, the interaction between paternal rearing and maternal rearing was significant; the effect of maternal AC on HA scores was strongest when combined with paternal neglectful parenting. The present study suggests that the AC type parenting by mothers is associated with specific personality traits, especially high HA, in healthy subjects.

  10. A feedback control system for vibration of magnetostrictive plate subjected to follower force using sinusoidal shear

    Directory of Open Access Journals (Sweden)

    A. Ghorbanpour Arani

    2016-03-01

    Full Text Available In this research, the vibrational behavior of magnetostrictive plate (MsP as a smart component is studied. The plate is subjected to an external follower force and a magnetic field in which the vibration response of MsP has been investigated for both loading combinations. The velocity feedback gain parameter is evaluated to study the effect of magnetic field which is generated by the coil. Sinusoidal shear deformation theory is utilized due to its accuracy of polynomial function with respect to other plate theories. Equations of motion are derived using Hamilton’s principle and solved by differential quadrature method (DQM considering general boundary conditions. The effects of aspect ratio, thickness ratio, follower force and velocity feedback gain are investigated on the frequency response of MsP. Results indicate that magneto-mechanical coupling in MsM helps to control vibrational behaviors of systems such as electro-hydraulic actuator, wireless linear Motors and sensors.

  11. Executive control of stimulus-driven and goal-directed attention in visual working memory.

    Science.gov (United States)

    Hu, Yanmei; Allen, Richard J; Baddeley, Alan D; Hitch, Graham J

    2016-10-01

    We examined the role of executive control in stimulus-driven and goal-directed attention in visual working memory using probed recall of a series of objects, a task that allows study of the dynamics of storage through analysis of serial position data. Experiment 1 examined whether executive control underlies goal-directed prioritization of certain items within the sequence. Instructing participants to prioritize either the first or final item resulted in improved recall for these items, and an increase in concurrent task difficulty reduced or abolished these gains, consistent with their dependence on executive control. Experiment 2 examined whether executive control is also involved in the disruption caused by a post-series visual distractor (suffix). A demanding concurrent task disrupted memory for all items except the most recent, whereas a suffix disrupted only the most recent items. There was no interaction when concurrent load and suffix were combined, suggesting that deploying selective attention to ignore the distractor did not draw upon executive resources. A final experiment replicated the independent interfering effects of suffix and concurrent load while ruling out possible artifacts. We discuss the results in terms of a domain-general episodic buffer in which information is retained in a transient, limited capacity privileged state, influenced by both stimulus-driven and goal-directed processes. The privileged state contains the most recent environmental input together with goal-relevant representations being actively maintained using executive resources.

  12. Real-time visual feedback of COM and COP motion properties differentially modifies postural control structures.

    Science.gov (United States)

    Kilby, Melissa C; Molenaar, Peter C M; Slobounov, Semyon M; Newell, Karl M

    2017-01-01

    The experiment was setup to investigate the control of human quiet standing through the manipulation of augmented visual information feedback of selective properties of the motion of two primary variables in postural control: center of pressure (COP) and center of mass (COM). Five properties of feedback information were contrasted to a no feedback dual-task (watching a movie) control condition to determine the impact of visual real-time feedback on the coordination of the joint motions in postural control in both static and dynamic one-leg standing postures. The feedback information included 2D COP or COM position and macro variables derived from the COP and COM motions, namely virtual time-to-contact (VTC) and the COP-COM coupling. The findings in the static condition showed that the VTC and COP-COM coupling feedback conditions decreased postural motion more than the 2D COP or COM positional information. These variables also induced larger sway amplitudes in the dynamic condition showing a more progressive search strategy in exploring the stability limits. Canonical correlation analysis (CCA) found that COP-COM coupling contributed less than the other feedback variables to the redundancy of the system reflected in the common variance between joint motions and properties of sway motion. The COP-COM coupling had the lowest weighting of the motion properties to redundancy under the feedback conditions but overall the qualitative pattern of the joint motion structures was preserved within the respective static and dynamic balance conditions.

  13. Influence of visual control, conduction, and central integration on static and dynamic balance in healthy older adults.

    Science.gov (United States)

    Perrin, P P; Jeandel, C; Perrin, C A; Béné, M C

    1997-01-01

    Aging is associated with decreased balance abilities, resulting in an increased risk of fall. In order to appreciate the visual, somatosensory, and central signals involved in balance control, sophisticated methods of posturography assessment have been developed, using static and dynamic tests, eventually associated with electromyographic measurements. We applied such methods to a population of healthy older adults in order to appreciate the respective importance of each of these sensorial inputs in aging individuals. Posture control parameters were recorded on a force-measuring platform in 41 healthy young (age 28.5 +/- 5.9 years) and 50 older (age 69.8 +/- 5.9 years) adults, using a static test and two dynamic tests performed by all individuals first with eyes open, then with eyes closed. The distance covered by the center of foot pressure, sway area, and anteroposterior oscillations were significantly higher, with eyes open or closed, in older people than in young subjects. Significant differences were noted in dynamic tests with longer latency responses in the group of old people. Dynamic recordings in a sinusoidal test had a more regular pattern when performed eyes open in both groups and evidenced significantly greater instability in old people. These data suggest that vision remains important in maintaining postural control while conduction and central integration become less efficient with age.

  14. Selection bias and subject refusal in a cluster-randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Rochelle Yang

    2017-07-01

    Full Text Available Abstract Background Selection bias and non-participation bias are major methodological concerns which impact external validity. Cluster-randomized controlled trials are especially prone to selection bias as it is impractical to blind clusters to their allocation into intervention or control. This study assessed the impact of selection bias in a large cluster-randomized controlled trial. Methods The Improved Cardiovascular Risk Reduction to Enhance Rural Primary Care (ICARE study examined the impact of a remote pharmacist-led intervention in twelve medical offices. To assess eligibility, a standardized form containing patient demographics and medical information was completed for each screened patient. Eligible patients were approached by the study coordinator for recruitment. Both the study coordinator and the patient were aware of the site’s allocation prior to consent. Patients who consented or declined to participate were compared across control and intervention arms for differing characteristics. Statistical significance was determined using a two-tailed, equal variance t-test and a chi-square test with adjusted Bonferroni p-values. Results were adjusted for random cluster variation. Results There were 2749 completed screening forms returned to research staff with 461 subjects who had either consented or declined participation. Patients with poorly controlled diabetes were found to be significantly more likely to decline participation in intervention sites compared to those in control sites. A higher mean diastolic blood pressure was seen in patients with uncontrolled hypertension who declined in the control sites compared to those who declined in the intervention sites. However, these findings were no longer significant after adjustment for random variation among the sites. After this adjustment, females were now found to be significantly more likely to consent than males (odds ratio = 1.41; 95% confidence interval = 1.03, 1

  15. The impact of translucent fabric shades and control strategies on energy savings and visual quality

    Science.gov (United States)

    Wankanapon, Pimonmart

    Translucent fabric shades provide opportunities for building occupants to control sunlight penetration for heat reduction, thermal comfort, and visual quality. Regulating shades affects building energy and can potentially reduce the size of mechanical cooling systems. Shades are not normally included in energy model studies during the design process, even though shades potential impact energy use. This is because the occupants normally leave shades closed a large fraction of the time, but models are generally performed with no shades. Automatic shade control is now available, so it is necessary to understand the impact of shades on visual quality and their energy saving potential in order to optimize their overall performance. There are very limited studies that have address shades and their integrated performance on energy consumption and visual quality. Most of these do not reflected modern shade types and their application. The goals of this study are: First, to determine the impact of shades on total, heating, cooling and lighting energy savings with different design and operation parameters. Second, to study and develop different automatic shade control strategies to promote and optimize energy savings and visual quality. A simulation-based approach using EnergyPlus in a parametric study provide better understanding energy savings under different shade conditions. The parametric runs addressed various building parameters such as geometry, orientation, site climate, glazing/shade properties, and shade control strategies with integrated lighting control. The impact of shades was determined for total building and space heating, cooling and lighting energy savings. The effect of shades on visual quality was studied using EnergyPlus, AGI32 and DAYSIM for several indices such as daylight glare index (DGI), work plane illuminance, luminance ratios and view. Different shade control strategies and integrated lighting control were considered with two translucent fabric

  16. Integration of bio-inspired, control-based visual and olfactory data for the detection of an elusive target

    Science.gov (United States)

    Duong, Tuan A.; Duong, Nghi; Le, Duong

    2017-01-01

    In this paper, we present an integration technique using a bio-inspired, control-based visual and olfactory receptor system to search for elusive targets in practical environments where the targets cannot be seen obviously by either sensory data. Bio-inspired Visual System is based on a modeling of extended visual pathway which consists of saccadic eye movements and visual pathway (vertebrate retina, lateral geniculate nucleus and visual cortex) to enable powerful target detections of noisy, partial, incomplete visual data. Olfactory receptor algorithm, namely spatial invariant independent component analysis, that was developed based on data of old factory receptor-electronic nose (enose) of Caltech, is adopted to enable the odorant target detection in an unknown environment. The integration of two systems is a vital approach and sets up a cornerstone for effective and low-cost of miniaturized UAVs or fly robots for future DOD and NASA missions, as well as for security systems in Internet of Things environments.

  17. Methylphenidate enhances brain activation and deactivation responses to visual attention and working memory tasks in healthy controls.

    Science.gov (United States)

    Tomasi, D; Volkow, N D; Wang, G J; Wang, R; Telang, F; Caparelli, E C; Wong, C; Jayne, M; Fowler, J S

    2011-02-14

    Methylphenidate (MPH) is a stimulant drug that amplifies dopamineric and noradrenergic signaling in the brain, which is believed to underlie its cognition enhancing effects. However, the neurobiological effects by which MPH improves cognition are still poorly understood. Here, functional magnetic resonance imaging (fMRI) was used together with working memory (WM) and visual attention (VA) tasks to test the hypothesis that 20mg oral MPH would increase activation in the dorsal attention network (DAN) and deactivation in the default mode network (DMN) as well as improve performance during cognitive tasks in healthy men. The group of subjects that received MPH (MPH group; N=16) had higher activation than the group of subjects who received no medication (control group: N=16) in DAN regions (parietal and prefrontal cortex, regions increasingly activated with increased cognitive load) and had increased deactivation in the insula and posterior cingulate cortex (regions increasingly deactivated with increased cognitive load) and these effects did not differ for the VA and the WM tasks. These findings provide the first evidence that MPH enhances activation of the DAN whereas it alters DMN deactivation. This suggests that MPH (presumably by amplifying dopamine and noradrenergic signaling) modulates cognition in part through its effects on DAN and DMN. Published by Elsevier Inc.

  18. Visual Information Theory and Visual Representation for Achieving Provable Bounds in Vision-Based Control and Decision

    Science.gov (United States)

    2014-07-30

    recognition). 01-AUG-13, . : , K. Tsotsos, A. Pretto, and S. Soatto. . Visual-inertial ego-motion estimation for humanoid platforms., Proc. IEEE Intl. Conf... Humanoid Robots. 12-JAN-12, . : , Alper Ayvaci, Michalis Raptis, Stefano Soatto. Optical flow and occlusion detection with convex optimization...with application to humanoid motion estimation While detachable object detection and semantic video segmentation provide topological rela- tions between

  19. Automated mapping of hippocampal atrophy in 1-year repeat MRI data from 490 subjects with Alzheimer's disease, mild cognitive impairment, and elderly controls.

    Science.gov (United States)

    Morra, Jonathan H; Tu, Zhuowen; Apostolova, Liana G; Green, Amity E; Avedissian, Christina; Madsen, Sarah K; Parikshak, Neelroop; Toga, Arthur W; Jack, Clifford R; Schuff, Norbert; Weiner, Michael W; Thompson, Paul M

    2009-03-01

    As one of the earliest structures to degenerate in Alzheimer's disease (AD), the hippocampus is the target of many studies of factors that influence rates of brain degeneration in the elderly. In one of the largest brain mapping studies to date, we mapped the 3D profile of hippocampal degeneration over time in 490 subjects scanned twice with brain MRI over a 1-year interval (980 scans). We examined baseline and 1-year follow-up scans of 97 AD subjects (49 males/48 females), 148 healthy control subjects (75 males/73 females), and 245 subjects with mild cognitive impairment (MCI; 160 males/85 females). We used our previously validated automated segmentation method, based on AdaBoost, to create 3D hippocampal surface models in all 980 scans. Hippocampal volume loss rates increased with worsening diagnosis (normal=0.66%/year; MCI=3.12%/year; AD=5.59%/year), and correlated with both baseline and interval changes in Mini-Mental State Examination (MMSE) scores and global and sum-of-boxes Clinical Dementia Rating scale (CDR) scores. Surface-based statistical maps visualized a selective profile of ongoing atrophy in all three diagnostic groups. Healthy controls carrying the ApoE4 gene atrophied faster than non-carriers, while more educated controls atrophied more slowly; converters from MCI to AD showed faster atrophy than non-converters. Hippocampal loss rates can be rapidly mapped, and they track cognitive decline closely enough to be used as surrogate markers of Alzheimer's disease in drug trials. They also reveal genetically greater atrophy in cognitively intact subjects.

  20. Sensorimotor control of tracking movements at various speeds for stroke patients as well as age-matched and young healthy subjects.

    Science.gov (United States)

    Ao, Di; Song, Rong; Tong, Kai-Yu

    2015-01-01

    There are aging- and stroke-induced changes on sensorimotor control in daily activities, but their mechanisms have not been well investigated. This study explored speed-, aging-, and stroke-induced changes on sensorimotor control. Eleven stroke patients (affected sides and unaffected sides) and 20 control subjects (10 young and 10 age-matched individuals) were enrolled to perform elbow tracking tasks using sinusoidal trajectories, which included 6 target speeds (15.7, 31.4, 47.1, 62.8, 78.5, and 94.2 deg/s). The actual elbow angle was recorded and displayed on a screen as visual feedback, and three indicators, the root mean square error (RMSE), normalized integrated jerk (NIJ) and integral of the power spectrum density of normalized speed (IPNS), were used to investigate the strategy of sensorimotor control. Both NIJ and IPNS had significant differences among the four groups (Pcontrols controls control. The RMSE increased with the increase in the target speed and the NIJ and IPNS initially declined and then remained steady for all four groups, which indicated a shift from feedback to feedforward control as the target speed increased. The feedback-feedforward trade-off induced by stroke, aging and speed might be explained by a change in the transmission delay and neuromotor noise. The findings in this study improve our understanding of the mechanism underlying the sensorimotor control and neurological changes caused by stroke and aging.

  1. Inter- and intra-observer agreement of BI-RADS-based subjective visual estimation of amount of fibroglandular breast tissue with magnetic resonance imaging: comparison to automated quantitative assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wengert, G.J.; Helbich, T.H.; Woitek, R.; Kapetas, P.; Clauser, P.; Baltzer, P.A. [Medical University of Vienna/ Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Vienna (Austria); Vogl, W.D. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Computational Imaging Research Lab, Wien (Austria); Weber, M. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of General and Pediatric Radiology, Wien (Austria); Meyer-Baese, A. [State University of Florida, Department of Scientific Computing in Medicine, Tallahassee, FL (United States); Pinker, Katja [Medical University of Vienna/ Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Vienna (Austria); State University of Florida, Department of Scientific Computing in Medicine, Tallahassee, FL (United States); Memorial Sloan-Kettering Cancer Center, Department of Radiology, Molecular Imaging and Therapy Services, New York City, NY (United States)

    2016-11-15

    To evaluate the inter-/intra-observer agreement of BI-RADS-based subjective visual estimation of the amount of fibroglandular tissue (FGT) with magnetic resonance imaging (MRI), and to investigate whether FGT assessment benefits from an automated, observer-independent, quantitative MRI measurement by comparing both approaches. Eighty women with no imaging abnormalities (BI-RADS 1 and 2) were included in this institutional review board (IRB)-approved prospective study. All women underwent un-enhanced breast MRI. Four radiologists independently assessed FGT with MRI by subjective visual estimation according to BI-RADS. Automated observer-independent quantitative measurement of FGT with MRI was performed using a previously described measurement system. Inter-/intra-observer agreements of qualitative and quantitative FGT measurements were assessed using Cohen's kappa (k). Inexperienced readers achieved moderate inter-/intra-observer agreement and experienced readers a substantial inter- and perfect intra-observer agreement for subjective visual estimation of FGT. Practice and experience reduced observer-dependency. Automated observer-independent quantitative measurement of FGT was successfully performed and revealed only fair to moderate agreement (k = 0.209-0.497) with subjective visual estimations of FGT. Subjective visual estimation of FGT with MRI shows moderate intra-/inter-observer agreement, which can be improved by practice and experience. Automated observer-independent quantitative measurements of FGT are necessary to allow a standardized risk evaluation. (orig.)

  2. Subjective Sleep Complaints in Pediatric Depression: A Controlled Study and Comparison with EEG Measures of Sleep and Waking

    Science.gov (United States)

    Bertocci, Michele A.; Dahl, Ronald E.; Williamson, Douglas E.; Iosif, Ana-Maria; Birmaher, Boris; Axelson, David; Ryan, Neal D.

    2005-01-01

    Objective: Children with major depressive disorder (MDD) often complain of sleep disturbances; however, polysomnographic studies have failed to find objective evidence of these disturbances. This article examines subjective sleep reports of children with MDD and healthy controls focusing on comparing subjective and objective sleep measures.…

  3. Influence of Whole-Body Vibration Training Without Visual Feedback on Balance and Lower-Extremity Muscle Strength of the Elderly: A Randomized Controlled Trial.

    Science.gov (United States)

    Tseng, Shiuan-Yu; Lai, Chung-Liang; Chang, Kai-Ling; Hsu, Pi-Shan; Lee, Meng-Chih; Wang, Chun-Hou

    2016-02-01

    The purpose of this study was to investigate the influence of whole-body vibration (WBV) training without visual feedback on balance and lower-extremity muscle strength in the elderly.Elderly subjects who did not exercise regularly participated in this study. Subjects were randomly divided into a WBV with eyes open group, a visual feedback-deprived plus WBV (VFDWBV) group, and a control group (0 Hz, eyes open). WBV training was provided over a 3-month period, 3 times per week for 5 min each session. Balance performance was measured with the limits of stability test, and muscle strength was measured with an isokinetic dynamometer.A total of 45 elderly subjects with an average age of 69.22  ±  3.97 years, divided into a WBV group (n = 14), a VFDWBV group (n = 17), and a control group (n = 14), completed the trial. Statistically significant differences were found in the balance performance of the 3 groups at different time points (time × group interaction: F = 13.213, P strength of the knee extensor and flexor muscles had time × group interactions: F = 29.604, P muscle strength than the WBV and control groups. The 6-month follow-up showed that the rates of hospital visits for medical services due to falls were 0% in the WBV group (0/14), 0% in the VFDWBV group (0/17), and 28.57% in the control group (4/14).Results showed that WBV training at 20  Hz without visual feedback can significantly improve the balance performance and lower-extremity muscle strength of the elderly.

  4. Suboccipital decompression enhances heart rate variability indices of cardiac control in healthy subjects.

    Science.gov (United States)

    Giles, Paul D; Hensel, Kendi L; Pacchia, Christina F; Smith, Michael L

    2013-02-01

    Osteopathic manipulative treatment (OMT) focused on the upper cervical spine is theorized to affect the function of the vagus nerve and thereby influence the parasympathetic branch of the autonomic nervous system. This study was designed to determine the acute effect of upper cervical spine manipulation on cardiac autonomic control as measured by heart rate variability. Nineteen healthy, young adult subjects underwent three different experimental interventions administered in random order: cervical OMT, sham manipulation, and time control. Six minutes of electrocardiographic data were collected before and after each intervention, and heart rate variability was assessed by both time-domain and frequency-domain measures. No differences in resting heart rate or any measure of heart rate variability were observed between the baseline periods prior to each intervention. The OMT protocol resulted in an increase in the standard deviation of the normal-to-normal intervals (0.12±0.082 seconds, p0.11 for all variables). These data support the hypothesis that upper cervical spine manipulation can acutely affect measures of heart rate variability in healthy individuals.

  5. Suboccipital Decompression Enhances Heart Rate Variability Indices of Cardiac Control in Healthy Subjects

    Science.gov (United States)

    Giles, Paul D.; Hensel, Kendi L.; Pacchia, Christina F.

    2013-01-01

    Abstract Objectives Osteopathic manipulative treatment (OMT) focused on the upper cervical spine is theorized to affect the function of the vagus nerve and thereby influence the parasympathetic branch of the autonomic nervous system. This study was designed to determine the acute effect of upper cervical spine manipulation on cardiac autonomic control as measured by heart rate variability. Design Nineteen healthy, young adult subjects underwent three different experimental interventions administered in random order: cervical OMT, sham manipulation, and time control. Six minutes of electrocardiographic data were collected before and after each intervention, and heart rate variability was assessed by both time-domain and frequency-domain measures. Results No differences in resting heart rate or any measure of heart rate variability were observed between the baseline periods prior to each intervention. The OMT protocol resulted in an increase in the standard deviation of the normal-to-normal intervals (0.12±0.082 seconds, p0.11 for all variables). Conclusions These data support the hypothesis that upper cervical spine manipulation can acutely affect measures of heart rate variability in healthy individuals. PMID:22994907

  6. Prepulse inhibition in euthymic bipolar disorder patients in comparison with control subjects.

    Science.gov (United States)

    Sánchez-Morla, E M; Mateo, J; Aparicio, A; García-Jiménez, M Á; Jiménez, E; Santos, J L

    2016-10-01

    Deficient prepulse inhibition (PPI) of the startle response, indicating sensorimotor gating deficits, has been reported in schizophrenia and other neuropsychiatric disorders. This study aimed to assess sensorimotor gating deficits in patients with euthymic bipolar. Furthermore, we analysed the relationships between PPI and clinical and cognitive measures. Prepulse inhibition was measured in 64 patients with euthymic bipolar and in 64 control subjects matched for age, gender, education level and smoking status. Clinical characteristics and level of functioning were assessed in all participants using Hamilton Depression Rating Scale (HDRS), Young Mania Rating Scale (YMRS) and Functioning Assessment Short Test (FAST). Cognition was evaluated using the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB) and the Stroop test as an additional measure of executive function. Compared with controls, patients with bipolar disorder exhibited PPI deficits at 60- and 120-millisecond prepulse-pulse intervals. Among patients with bipolar disorder, PPI was correlated with the social cognition domain of the MCCB. PPI was not significantly correlated with other clinical, functional and neurocognitive variables in either group. Our data suggest that PPI deficit is a neurobiological marker in euthymic bipolar disorder, which is associated with social cognition but not with other clinical, functional or cognitive measures. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Contrasting Complement Control, Temporal Adjunct Control and Controlled Verbal Gerund Subjects in ASD: The Role of Contextual Cues in Reference Assignment.

    Science.gov (United States)

    Janke, Vikki; Perovic, Alexandra

    2017-01-01

    This study examines two complex syntactic dependencies (complement control and sentence-final temporal adjunct control) and one pragmatic dependency (controlled verbal gerund subjects) in children with ASD. Sixteen high-functioning (HFA) children (aged 6-16) with a diagnosis of autism and no language impairment, matched on age, gender and non-verbal MA to one TD control group, and on age, gender and verbal MA to another TD control group, undertook three picture-selection tasks. Task 1 measured their base-line interpretations of the empty categories (ec). Task 2 preceded these sentence sets with a weakly established topic cueing an alternative referent and Task 3 with a strongly established topic cueing an alternative referent. In complement control (Ron persuaded Hermione ec to kick the ball) and sentence-final temporal adjunct control (Harry tapped Luna while ec feeding the owl), the reference of the ec is argued to be related obligatorily to the object and subject respectively. In controlled verbal-gerund subjects (VGS) (ec Rowing the boat clumsily made Luna seasick), the ec's reference is resolved pragmatically. Referent choices across the three tasks were compared. TD children chose the object uniformly in complement control across all tasks but in adjunct control, preferences shifted toward the object in Task 3. In controlled VGSs, they exhibited a strong preference for an internal-referent interpretation in Task 1, which shifted in the direction of the cues in Tasks 2 and 3. HFA children gave a mixed performance. They patterned with their TD counterparts on complement control and controlled VGSs but performed marginally differently on adjunct control: no TD groups were influenced by the weakly established topic in Task 2 but all groups were influenced by the strongly established topic in Task 3. HFA children were less influenced than the TD children, resulting in their making fewer object choices overall but revealing parallel patterns of performance. In this

  8. Cost-effectiveness of nutritional intervention in elderly subjects after hip fracture. A randomized controlled trial.

    Science.gov (United States)

    Wyers, C E; Reijven, P L M; Evers, S M A A; Willems, P C; Heyligers, I C; Verburg, A D; van Helden, S; Dagnelie, P C

    2013-01-01

    Hip fracture patients can benefit from nutritional supplementation during their recovery. Up to now, cost-effectiveness evaluation of nutritional intervention in these patients has not been performed. Costs of nutritional intervention are relatively low as compared with medical costs. Cost-effectiveness evaluation shows that nutritional intervention is likely to be cost-effective. Previous research on the effect of nutritional intervention on clinical outcome in hip fracture patients yielded contradictory results. Cost-effectiveness of nutritional intervention in these patients remains unknown. The aim of this study was to evaluate cost-effectiveness of nutritional intervention in elderly subjects after hip fracture from a societal perspective. Open-label, multi-centre randomized controlled trial investigating cost-effectiveness of intensive nutritional intervention comprising regular dietetic counseling and oral nutritional supplementation for 3 months postoperatively. Patients allocated to the control group received care as usual. Costs, weight and quality of life were measured at baseline and at 3 and 6 months postoperatively. Incremental cost-effectiveness ratios (ICERs) were calculated for weight at 3 months and quality adjusted life years (QALYs) at 6 months postoperatively. Of 152 patients enrolled, 73 were randomized to the intervention group and 79 to the control group. Mean costs of the nutritional intervention was 613 Euro. Total costs and subcategories of costs were not significantly different between both groups. Based on bootstrapping of ICERs, the nutritional intervention was likely to be cost-effective for weight as outcome over the 3-month intervention period, regardless of nutritional status at baseline. With QALYs as outcome, the probability for the nutritional intervention being cost-effective was relatively low, except in subjects aged below 75 years. Intensive nutritional intervention in elderly hip fracture patients is likely to be cost

  9. Rheumatoid Arthritis - Neuropsychology, Depression and Anxiety. A case - control study -120 Portuguese Female subjects.

    Directory of Open Access Journals (Sweden)

    Luis Maia

    2012-07-01

    Full Text Available Objectives: Impact of Rheumatoid Arthritis in cognitive functions has not been well acknowledged in Portugal. With this original article we intended to elucidate this problem in this specific country. Methods: We measured the results of 60 Rheumatoid Arthritis female patients (study group, comparing every patient in a case control paired plan (years in school and age, with control subjects (n = 60, in a total of 120 subjects. All participants were evaluated with Paced Auditory Selective Attention Test, Word List Generation Test, Luria Nebraska Neuropsychological Battery, a Portuguese depressive screening test (IACLIDE, STAI (anxiety trace and trait test and the Mini Mental state examination.Results: The outcomes demonstrate, for the first conclusive time in Portuguese patients, the occurrence of main deficits in terms of cognitive functioning (measured by a variety ofneuropsychological tests, and depressive and anxietysymptomatology. Conclusion: This article asset the need to pay attention in psychoeducational, psychotherapeutic and cognitive stimulation, and reinforcement of neuropsychological intervention in these types of patients.Objectivos: O impacto da artrite reumatóide nas funçõescognitivas não tem sido bem reconhecido em Portugal. Com este artigo original pretendemos elucidar este problema neste país específico.Métodos: Avaliámos os resultados de 60 pacientes femininos com artrite reumatóide (grupo de estudo, comparando cada paciente num estudo de caso-controle, emparelhando ossujeitos com Artrite Reumatóide (60 sujeitos com 60 pacientes Artrite Reumatóide, nas variáveis anos de escolaridade eidade (a variável género era uma constante = feminino.Todos os participantes foram avaliados com o Teste de Atenção Auditiva Selectiva (PASAT, teste de geração de lista de palavras, Bateria Neuropsicológica de Luria Nebraska, um teste português de despistagem de sintomatologia depressiva (IACLIDE, um teste de rastreamento de tra

  10. Altered inhibitory control and increased sensitivity to cross-modal interference in tinnitus during auditory and visual tasks.

    Directory of Open Access Journals (Sweden)

    Rodrigo Araneda

    Full Text Available Tinnitus is the perception of sound in the absence of external stimulus. Currently, the pathophysiology of tinnitus is not fully understood, but recent studies indicate that alterations in the brain involve non-auditory areas, including the prefrontal cortex. In experiment 1, we used a go/no-go paradigm to evaluate the target detection speed and the inhibitory control in tinnitus participants (TP and control subjects (CS, both in unimodal and bimodal conditions in the auditory and visual modalities. We also tested whether the sound frequency used for target and distractors affected the performance. We observed that TP were slower and made more false alarms than CS in all unimodal auditory conditions. TP were also slower than CS in the bimodal conditions. In addition, when comparing the response times in bimodal and auditory unimodal conditions, the expected gain in bimodal conditions was present in CS, but not in TP when tinnitus-matched frequency sounds were used as targets. In experiment 2, we tested the sensitivity to cross-modal interference in TP during auditory and visual go/no-go tasks where each stimulus was preceded by an irrelevant pre-stimulus in the untested modality (e.g. high frequency auditory pre-stimulus in visual no/no-go condition. We observed that TP had longer response times than CS and made more false alarms in all conditions. In addition, the highest false alarm rate occurred in TP when tinnitus-matched/high frequency sounds were used as pre-stimulus. We conclude that the inhibitory control is altered in TP and that TP are abnormally sensitive to cross-modal interference, reflecting difficulties to ignore irrelevant stimuli. The fact that the strongest interference effect was caused by tinnitus-like auditory stimulation is consistent with the hypothesis according to which such stimulations generate emotional responses that affect cognitive processing in TP. We postulate that executive functions deficits play a key-role in

  11. Conditions affecting the activity of glucocerebrosidase purified from spleens of control subjects and patients with type 1 Gaucher disease

    NARCIS (Netherlands)

    Aerts, J. M.; Sa Miranda, M. C.; Brouwer-Kelder, E. M.; van Weely, S.; Barranger, J. A.; Tager, J. M.

    1990-01-01

    Glucocerebrosidase was purified to homogeneity from spleens of control subjects and Type 1 Gaucher disease patients by immunoaffinity chromatography. Activation of the enzyme by taurocholate, phosphatidylserine and sphingolipid activator protein 2 (saposin C; SAP-2) was investigated by titration of

  12. Volitional regulation of emotions produces distributed alterations in connectivity between visual, attention control, and default networks.

    Science.gov (United States)

    Sripada, Chandra; Angstadt, Michael; Kessler, Daniel; Phan, K Luan; Liberzon, Israel; Evans, Gary W; Welsh, Robert C; Kim, Pilyoung; Swain, James E

    2014-04-01

    The ability to volitionally regulate emotions is critical to health and well-being. While patterns of neural activation during emotion regulation have been well characterized, patterns of connectivity between regions remain less explored. It is increasingly recognized that the human brain is organized into large-scale intrinsic connectivity networks (ICNs) whose interrelationships are altered in characteristic ways during psychological tasks. In this fMRI study of 54 healthy individuals, we investigated alterations in connectivity within and between ICNs produced by the emotion regulation strategy of reappraisal. In order to gain a comprehensive picture of connectivity changes, we utilized connectomic psychophysiological interactions (PPI), a whole-brain generalization of standard single-seed PPI methods. In particular, we quantified PPI connectivity pair-wise across 837 ROIs placed throughout the cortex. We found that compared to maintaining one's emotional responses, engaging in reappraisal produced robust and distributed alterations in functional connections involving visual, dorsal attention, frontoparietal, and default networks. Visual network in particular increased connectivity with multiple ICNs including dorsal attention and default networks. We interpret these findings in terms of the role of these networks in mediating critical constituent processes in emotion regulation, including visual processing, stimulus salience, attention control, and interpretation and contextualization of stimuli. Our results add a new network perspective to our understanding of the neural underpinnings of emotion regulation, and highlight that connectomic methods can play a valuable role in comprehensively investigating modulation of connectivity across task conditions. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Brief Report: Cognitive Control of Social and Nonsocial Visual Attention in Autism.

    Science.gov (United States)

    DiCriscio, Antoinette Sabatino; Miller, Stephanie J; Hanna, Eleanor K; Kovac, Megan; Turner-Brown, Lauren; Sasson, Noah J; Sapyta, Jeffrey; Troiani, Vanessa; Dichter, Gabriel S

    2016-08-01

    Prosaccade and antisaccade errors in the context of social and nonsocial stimuli were investigated in youth with autism spectrum disorder (ASD; n = 19) a matched control sample (n = 19), and a small sample of youth with obsessive compulsive disorder (n = 9). Groups did not differ in error rates in the prosaccade condition for any stimulus category. In the antisaccade condition, the ASD group demonstrated more errors than the control group for nonsocial stimuli related to circumscribed interests, but not for other nonsocial stimuli or for social stimuli. Additionally, antisaccade error rates were predictive of core ASD symptom severity. Results indicate that the cognitive control of visual attention in ASD is impaired specifically in the context of nonsocial stimuli related to circumscribed interests.

  14. Research on optimized control of Six - DOF manipulator with uncalibrated visual servo

    Science.gov (United States)

    Zhang, Nu; Wang, Niu; Zhao, Junrong

    2017-04-01

    This paper realizes the uncalibrated visual servoless control of the Six-DOF manipulator, where the intrinsic and extrinsic parameters of the camera and the robot manipulator model are not known, nor real-time computes the inverse of image Jacobian. And the neural network was used to optimize the trajectory of manipulator end in Cartesian space. Firstly, a biaxial parallel layoutt are proposed to establish the relationship between the moving component along the coordinate axis and the change of single image feature when the end of the robot moves in the Cartesian space. The neural network was used to fit the relationship established above, then the optimization model was established, and the parameter of PID controller were optimized by neural network. Finally, the simulation and comparison experiments are investigated, and the results indicate the controller posed in this paper is effective and stable.

  15. The dynamics of orbital maneuvering: Design and evaluation of a visual display aid for human controllers

    Science.gov (United States)

    Ellis, Stephen R.; Grunwald, Arthur J.

    1990-01-01

    An interactive proximity operations planning system, which allows on-site planning of fuel-efficient, multi-burn maneuvers in a potential multi-spacecraft environment was developed and tested. Though this display system most directly assists planning by providing visual feedback to aid visualization of the trajectories and constraints, its most significant features include an inverse dynamics algorithm that removes control nonlinearities facing the operator and a trajectory planning technique that reduces the order of control and creates, through a geometric spread-sheet the illusion of an inertially stable environment. This synthetic environment provides the user with control of relevant static and dynamic properties of way-points during small orbital changes allowing independent solutions to the normally coupled problems of orbital maneuvering. An experiment was carried out in which experienced operators were required to plan a trajectory to retrieve an object accidently separated from a dual-keel space station. The time required to plan these maneuvers was found to be predicted by the direction of the insertion thrust and did not depend on the point of separation from the space station.

  16. Motivation toward Physical Exercise and Subjective Wellbeing: The Mediating Role of Trait Self-Control

    Science.gov (United States)

    Briki, Walid

    2016-01-01

    Motivation toward physical exercise (MPE) and trait self-control (TSC) were identified as key predictors of subjective wellbeing (SWB). However, there has not been any research designed to examine the mediating role of TSC in the relationship between MPE and SWB. The present study utilizes self-determination theory, control-process theory of self-regulation, and theory of multiple pathways of TSC in order to examine whether TSC mediates the relationships of autonomous MPE (A-MPE), controlled MPE (C-MPE), and impersonal MPE (NO-MPE) with SWB using structural equation modeling (XLSTAT PLS). Three hundred seventeen adult American individuals (Mage = 32.97, SDage = 11.30), who reported to be regular exercisers, voluntarily answered questionnaires assessing MPE, TSC, and SWB. Correlational analyses revealed positive relationships between A-MPE, TSC, and SWB, and negative relationships of C-MPE and NO-MPE with TSC and SWB. Mediation analyses revealed that TSC mediated the relationships of A-MPE (partial mediation) and C-MPE (full mediation) with SWB, but did not mediate the relationship between NO-MPE and SWB. The estimates of the quality of the hypothesized model were acceptable (outer model GoF = 0.935; absolute GoF = 0.330; relative GoF = 0.942; inner model GoF = 1.008; R2 = 36.947%). Finally, this study supports the view that MPE can influence SWB through TSC, and incites to pursue the examination of the relationships between self-determined motivation, self-regulation mechanisms, and health-related outcomes. PMID:27761126

  17. Motivation toward Physical Exercise and Subjective Wellbeing: The Mediating Role of Trait Self-Control.

    Science.gov (United States)

    Briki, Walid

    2016-01-01

    Motivation toward physical exercise (MPE) and trait self-control (TSC) were identified as key predictors of subjective wellbeing (SWB). However, there has not been any research designed to examine the mediating role of TSC in the relationship between MPE and SWB. The present study utilizes self-determination theory, control-process theory of self-regulation, and theory of multiple pathways of TSC in order to examine whether TSC mediates the relationships of autonomous MPE (A-MPE), controlled MPE (C-MPE), and impersonal MPE (NO-MPE) with SWB using structural equation modeling (XLSTAT PLS). Three hundred seventeen adult American individuals (Mage = 32.97, SDage = 11.30), who reported to be regular exercisers, voluntarily answered questionnaires assessing MPE, TSC, and SWB. Correlational analyses revealed positive relationships between A-MPE, TSC, and SWB, and negative relationships of C-MPE and NO-MPE with TSC and SWB. Mediation analyses revealed that TSC mediated the relationships of A-MPE (partial mediation) and C-MPE (full mediation) with SWB, but did not mediate the relationship between NO-MPE and SWB. The estimates of the quality of the hypothesized model were acceptable (outer model GoF = 0.935; absolute GoF = 0.330; relative GoF = 0.942; inner model GoF = 1.008; R2 = 36.947%). Finally, this study supports the view that MPE can influence SWB through TSC, and incites to pursue the examination of the relationships between self-determined motivation, self-regulation mechanisms, and health-related outcomes.

  18. Motivation toward Physical Exercise and Subjective Wellbeing: The Mediating Role of Trait Self-Control

    Directory of Open Access Journals (Sweden)

    Walid Briki

    2016-10-01

    Full Text Available Motivation toward physical exercise (MPE and trait self-control (TSC were identified as key predictors of subjective wellbeing (SWB. However, there has not been any research designed to examine the mediating role of TSC in the relationship between MPE and SWB. The present study utilizes self-determination theory, control-process theory of self-regulation, and theory of multiple pathways of TSC in order to examine whether TSC mediates the relationships of autonomous MPE (A-MPE, controlled MPE (C-MPE, and impersonal MPE (NO-MPE with SWB using structural equation modeling (XLSTAT PLS. Three hundred seventeen adult American individuals (Mage = 32.97, SDage = 11.30, who reported to be regular exercisers, voluntarily answered questionnaires assessing MPE, TSC, and SWB. Correlational analyses revealed positive relationships between A-MPE, TSC, and SWB, and negative relationships of C-MPE and NO-MPE with TSC and SWB. Mediation analyses revealed that TSC mediated the relationships of A-MPE (partial mediation and C-MPE (full mediation with SWB, but did not mediate the relationship between NO-MPE and SWB. The estimates of the quality of the hypothesized model were acceptable (outer model GoF = .935; absolute GoF = .330; relative GoF = .942; inner model GoF = 1.008; R2 = 36.947%. Finally, this study supports the view that MPE can influence SWB through TSC, and incites to pursue the examination of the relationships between self-determined motivation, self-regulation mechanisms, and health-related outcomes.

  19. Assessment of Visual Reliance in Balance Control: An Inexpensive Extension of the Static Posturography.

    Science.gov (United States)

    Púčik, Jozef; Šaling, Marián; Lukáč, Tomáš; Ondráček, Oldřich; Kucharík, Martin

    2014-01-01

    Ability of humans to maintain balance in an upright stance and during movement activities is one of the most natural skills affecting everyday life. This ability progressively deteriorates with increasing age, and balance impairment, often aggravated by age-related diseases, can result in falls that adversely impact the quality of life. Falls represent serious problems of health concern associated with aging. Many investigators, involved in different science disciplines such as medicine, engineering, psychology, and sport, have been attracted by a research of the human upright stance. In a clinical practice, stabilometry based on the force plate is the most widely available procedure used to evaluate the balance. In this paper, we have proposed a low-cost extension of the conventional stabilometry by the multimedia technology that allows identifying potentially disturbing effects of visual sensory information. Due to the proposed extension, a stabilometric assessment in terms of line integral of center of pressure (COP) during moving scene stimuli shows higher discrimination power between young healthy and elderly subjects with supposed stronger visual reliance.

  20. Assessment of Visual Reliance in Balance Control: An Inexpensive Extension of the Static Posturography

    Directory of Open Access Journals (Sweden)

    Jozef Púčik

    2014-01-01

    Full Text Available Ability of humans to maintain balance in an upright stance and during movement activities is one of the most natural skills affecting everyday life. This ability progressively deteriorates with increasing age, and balance impairment, often aggravated by age-related diseases, can result in falls that adversely impact the quality of life. Falls represent serious problems of health concern associated with aging. Many investigators, involved in different science disciplines such as medicine, engineering, psychology, and sport, have been attracted by a research of the human upright stance. In a clinical practice, stabilometry based on the force plate is the most widely available procedure used to evaluate the balance. In this paper, we have proposed a low-cost extension of the conventional stabilometry by the multimedia technology that allows identifying potentially disturbing effects of visual sensory information. Due to the proposed extension, a stabilometric assessment in terms of line integral of center of pressure (COP during moving scene stimuli shows higher discrimination power between young healthy and elderly subjects with supposed stronger visual reliance.

  1. Evaluation of vardenafil for the treatment of subjective tinnitus: a controlled pilot study

    Directory of Open Access Journals (Sweden)

    Stöver Timo

    2009-02-01

    Full Text Available Abstract Background Vardenafil (Levitra® represents a potent and highly selective phosphodiesterase type 5 (PDE5 inhibitor, which is established for treatment of various diseases. There are several unpublished reports from patients stating that vardenafil has a considerable therapeutic effect on their concomitant tinnitus. This pilot study was conducted to specifically assess the effect of vardenafil in patients with chronic tinnitus. Methods This trial was based on a prospective, randomized, double-blind, placebo-controlled, parallel group design. Fourty-two consecutive subjects with mon- or binaural chronic tinnitus received 10 mg vardenafil (N = 21 or matching placebo tablets (N = 21 administered orally twice a day over a period of 12 weeks. Clinical examination and data acquisition took place at each visit: at baseline, after 4 weeks, after 12 weeks (end of treatment with study medication, and at non-medicated follow-up after 16 weeks. Assessment of clinical effectiveness was based on a standardized tinnitus questionnaire (TQ, the Short Form 36 health survey (SF-36, audiometric measurements (mode, pitch and loudness of tinnitus; auditory thresholds and biomarkers of oxidative stress in patients' blood (malondialdehyde, protein carbonyl, homocysteine and total antioxidative status. Therapeutic efficacy was evaluated by comparison of subjective and objective parameters with baseline data between both treatment groups (ANCOVA. Results Vardenafil had no superior efficacy over placebo in the treatment of chronic tinnitus during this study. The primary efficacy criterion 'TQ total score' failed to demonstrate significant improvement compared to placebo. Subjective reports of TQ subscales and general quality of life areas (SF-36, objective audiometric examinations as well as investigated biomarkers for oxidative stress did not reveal any significant treatment effects. The safety profile was favorable and consistent with that in other vardenafil

  2. The impact of cataract surgery on visual functioning, vision-related disability and psychological distress: a randomized controlled trial.

    Science.gov (United States)

    Walker, Janine G; Anstey, Kaarin J; Hennessy, Michael P; Lord, Stephen R; von Sanden, Chwee

    2006-11-01

    Determine whether there are changes in visual functioning, vision-related disability, health status and mood after cataract surgery. 45 adults (mean age = 73.7 years) with bilateral cataract needing surgery for the first eye were recruited from public ophthalmology clinics. The Visual Functioning-14 survey assessed visual disability. Minimal angle of resolution tested visual acuity, and the Melbourne Edge Test examined contrast sensitivity. Demographic, psychological, health and medication use variables were examined. Participants were randomized to either an intervention or control arm. Controls were assessed on two occasions at a 3-month interval before having surgery. The intervention group was assessed 1-2 weeks before surgery and then reassessed 3 months after surgery. Visual functioning improved for those who had cataract surgery with better visual acuity in the better (P = 0.010) and worse (P = 0.028) eye compared with controls. The intervention group reported fewer difficulties with overall vision-related disability (P = 0.0001), reading (P = 0.004) and instrumental activities of daily living (P = 0.010) post-surgery compared with controls. People with improved depression scores (P = 0.048) after surgery had less difficulty with reading compared with those with unchanged or worsened depression scores. Cataract surgery did not improve health status. First eye cataract surgery is effective in improving outcomes in visual functioning and disability. Improved mood after surgery was related to less vision-related disability compared with unchanged or worse depression.

  3. How the range effect contaminates control scores in studies of visual illusions.

    Science.gov (United States)

    Hotopf, W H; Brown, S A

    1993-01-01

    The relationship between mean control scores and mean experimental scores in 23 experiments on alignment illusions has been examined. Evidence is presented to show that, through the operation of the range effect, control scores are biased to a significant degree in the direction of experimental scores. The implications of this are considered, not only as regards the value of control scores in psychophysical studies, but also as further evidence of the dangers of within-subjects experimental designs when issues depend upon the values of extreme points in a range of values.

  4. Visual control of wheeled mobile robots unifying vision and control in generic approaches

    CERN Document Server

    Becerra, Héctor M

    2014-01-01

    Vision-based control of wheeled mobile robots is an interesting field of research from a scientific and even social point of view due to its potential applicability. This book presents a formal treatment of some aspects of control theory applied to the problem of vision-based pose regulation of wheeled mobile robots. In this problem, the robot has to reach a desired position and orientation, which are specified by a target image. It is faced in such a way that vision and control are unified to achieve stability of the closed loop, a large region of convergence, without local minima, and good robustness against parametric uncertainty. Three different control schemes that rely on monocular vision as unique sensor are presented and evaluated experimentally. A common benefit of these approaches is that they are valid for imaging systems obeying approximately a central projection model, e.g., conventional cameras, catadioptric systems and some fisheye cameras. Thus, the presented control schemes are generic approa...

  5. Whole Grain Intake and Glycaemic Control in Healthy Subjects: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Stefano Marventano

    2017-07-01

    Full Text Available Backgrounds: There is growing evidence from both observational and intervention studies that Whole Grain (WG cereals exert beneficial effects on human health, especially on the metabolic profile. The aim of this study was to perform a meta-analysis of randomised controlled trials (RCT to assess the acute and medium/long-term effect of WG foods on glycaemic control and insulin sensitivity in healthy individuals. Methods: A search for all the published RCT on the effect of WG food intake on glycaemic and insulin response was performed up to December 2016. Effect size consisted of mean difference (MD and 95% CI between the outcomes of intervention and the control groups using the generic inverse-variance random effects model. Results: The meta-analysis of the 14 studies testing the acute effects of WG foods showed significant reductions of the post-prandial values of the glucose iAUC (0–120 min by −29.71 mmol min/L (95% CI: −43.57, −15.85 mmol min/L, the insulin iAUC (0–120 min by −2.01 nmol min/L (95% CI: −2.88, −1.14 nmol min/L, and the maximal glucose and insulin response. In 16 medium- and long-term RCTs, effects of WG foods on fasting glucose and insulin and homeostatic model assessment-insulin resistance values were not significant. Conclusions: The consumption of WG foods is able to improve acutely the postprandial glucose and insulin homeostasis compared to similar refined foods in healthy subjects. Further research is needed to better understand the long-term effects and the biological mechanisms.

  6. Self-Control and Impulsiveness in Nondieting Adult Human Females: Effects of Visual Food Cues and Food Deprivation

    Science.gov (United States)

    Forzano, Lori-Ann B.; Chelonis, John J.; Casey, Caitlin; Forward, Marion; Stachowiak, Jacqueline A.; Wood, Jennifer

    2010-01-01

    Self-control can be defined as the choice of a larger, more delayed reinforcer over a smaller, less delayed reinforcer, and impulsiveness as the opposite. Previous research suggests that exposure to visual food cues affects adult humans' self-control. Previous research also suggests that food deprivation decreases adult humans' self-control. The…

  7. Effects of a Psychoeducational Group on Mood and Glycemic Control in Adults with Diabetes and Visual Impairments.

    Science.gov (United States)

    Trozzolino, Linda; Thompson, Pamela S.; Tansman, Mara S.; Azen, Stanley P.

    2003-01-01

    This study evaluated the effectiveness of a 12-week psychoeducational group therapy program in improving mood and glycemic control in 48 adults with diabetes and visual impairments. Participants made statistically significant gains in glycemic control. There was a significant positive relationship between control and improvement in depression, but…

  8. Visual analytics of geo-social interaction patterns for epidemic control.

    Science.gov (United States)

    Luo, Wei

    2016-08-10

    Human interaction and population mobility determine the spatio-temporal course of the spread of an airborne disease. This research views such spreads as geo-social interaction problems, because population mobility connects different groups of people over geographical locations via which the viruses transmit. Previous research argued that geo-social interaction patterns identified from population movement data can provide great potential in designing effective pandemic mitigation. However, little work has been done to examine the effectiveness of designing control strategies taking into account geo-social interaction patterns. To address this gap, this research proposes a new framework for effective disease control; specifically this framework proposes that disease control strategies should start from identifying geo-social interaction patterns, designing effective control measures accordingly, and evaluating the efficacy of different control measures. This framework is used to structure design of a new visual analytic tool that consists of three components: a reorderable matrix for geo-social mixing patterns, agent-based epidemic models, and combined visualization methods. With real world human interaction data in a French primary school as a proof of concept, this research compares the efficacy of vaccination strategies between the spatial-social interaction patterns and the whole areas. The simulation results show that locally targeted vaccination has the potential to keep infection to a small number and prevent spread to other regions. At some small probability, the local control strategies will fail; in these cases other control strategies will be needed. This research further explores the impact of varying spatial-social scales on the success of local vaccination strategies. The results show that a proper spatial-social scale can help achieve the best control efficacy with a limited number of vaccines. The case study shows how GS-EpiViz does support the design

  9. EMG and kinematic analysis of sensorimotor control for patients after stroke using cyclic voluntary movement with visual feedback

    Directory of Open Access Journals (Sweden)

    Song Rong

    2013-02-01

    Full Text Available Abstract Background Clinical scales are often used to evaluate upper-limb deficits. The objective of this study is to investigate the parameters during voluntary arm tracking at different velocities for evaluating motor control performance after stroke. Methods Eight hemiplegic chronic stroke subjects were recruited to perform voluntary movements of elbow flexion and extension by following sinusoidal trajectories from 30 deg to 90 deg at six velocities in the horizontal plane by completing 3, 6, 8, 12, 15, 18 flexion and extension cycles in 36 seconds in a single trial, and the peak velocities ranged from 15.7 to 94.2 deg/s. The actual elbow angle and the target position were displayed as real-time visual feedback. The angular displacement of the arm and electromyographic (EMG signals of biceps and triceps were captured to evaluate the sensorimotor control of the affected and unaffected side. Results The results showed significant differences in the root mean square error (RMSE, response delay (RD and cocontraction index (CI when the affected and unaffected sides were compared during the arm tracking experiment (P Conclusions The method and parameters have potential for clinical use in quantitatively evaluating the sensorimotor deficiencies for patients after stroke about the accuracy of motion, response delay and cocontraction between muscle pairs.

  10. Lactate: Brain Fuel in Human Traumatic Brain Injury: A Comparison with Normal Healthy Control Subjects

    Science.gov (United States)

    Martin, Neil A.; Horning, Michael A.; McArthur, David L.; Hovda, David A.; Vespa, Paul; Brooks, George A.

    2015-01-01

    Abstract We evaluated the hypothesis that lactate shuttling helps support the nutritive needs of injured brains. To that end, we utilized dual isotope tracer [6,6-2H2]glucose, that is, D2-glucose, and [3-13C]lactate techniques involving arm vein tracer infusion along with simultaneous cerebral (arterial [art] and jugular bulb [JB]) blood sampling. Traumatic brain injury (TBI) patients with nonpenetrating brain injuries (n=12) were entered into the study following consent of patients' legal representatives. Written and informed consent was obtained from control volunteers (n=6). Patients were studied 5.7±2.2 (mean±SD) days post-injury; during periods when arterial glucose concentration tended to be higher in TBI patients. As in previous investigations, the cerebral metabolic rate for glucose (CMRgluc, i.e., net glucose uptake) was significantly suppressed following TBI (pcerebral lactate uptake related to systemic lactate supply, approximated 11% in both healthy control subjects and TBI patients. Further, neither the CMR for lactate (CMRlac, i.e., net lactate release), nor the tracer-measured cerebral lactate uptake differed between healthy controls and TBI patients. The percentages of lactate tracer taken up and released as 13CO2 into the JB accounted for 92% and 91% for control and TBI conditions, respectively, suggesting that most cerebral lactate uptake was oxidized following TBI. Comparisons of isotopic enrichments of lactate oxidation from infused [3-13C]lactate tracer and 13C-glucose produced during hepatic and renal gluconeogenesis (GNG) showed that 75–80% of 13CO2 released into the JB was from lactate and that the remainder was from the oxidation of glucose secondarily labeled from lactate. Hence, either directly as lactate uptake, or indirectly via GNG, peripheral lactate production accounted for ∼70% of carbohydrate (direct lactate uptake+uptake of glucose from lactate) consumed by the injured brain. Undiminished cerebral lactate fractional

  11. Static and dynamic posture control in postlingual cochlear implanted patients: effects of dual-tasking, visual and auditory inputs suppression.

    Science.gov (United States)

    Bernard-Demanze, Laurence; Léonard, Jacques; Dumitrescu, Michel; Meller, Renaud; Magnan, Jacques; Lacour, Michel

    2013-01-01

    Posture control is based on central integration of multisensory inputs, and on internal representation of body orientation in space. This multisensory feedback regulates posture control and continuously updates the internal model of body's position which in turn forwards motor commands adapted to the environmental context and constraints. The peripheral localization of the vestibular system, close to the cochlea, makes vestibular damage possible following cochlear implant (CI) surgery. Impaired vestibular function in CI patients, if any,