WorldWideScience

Sample records for active spatial perception

  1. When endogenous spatial attention improves conscious perception: effects of alerting and bottom-up activation.

    Science.gov (United States)

    Botta, Fabiano; Lupiáñez, Juan; Chica, Ana B

    2014-01-01

    Recent studies have consistently demonstrated that conscious perception interacts with exogenous attentional orienting, but it can be dissociated from endogenous attentional orienting (Chica Lasaponara, et al., 2011; Wyart & Tallon-Baudry, 2008). It has been hypothesized that enhanced conscious processing at exogenously attended locations results from a synergistic action of spatial orienting, bottom-up activation, and phasic alerting induced by the abrupt onset of the exogenous cue (Chica, Lasaponara, et al., 2011). Instead, as endogenous cues need more time to be interpreted, the phasic alerting they produce may have dissipated when the target appears. Furthermore, endogenous cues presumably elicit a weak bottom-up activation at the cued location. Consistent with these hypotheses, we observed that endogenous attention modulated conscious perception, but only when phasic alerting or bottom-up activation was increased. Results are discussed in the context of recent theoretical models of consciousness (Dehaene, Changeux, Naccache, Sackur, & Sergent, 2006). Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Embodied Perception: A Proposal to Reconcile Affordance and Spatial Perception

    OpenAIRE

    Ca?al-Bruland, Rouwen; van der Kamp, John

    2015-01-01

    Proffitt's embodied approach to perception is deeply indebted to Gibson's ecological approach to visual perception, in particular the idea that the primary objects of perception are affordances or what the environment offers for action. Yet, rather than directly addressing affordance perception, most of the empirical work evaluating Proffitt's approach focuses on the perception of spatial properties of the environment. We propose that theoretical and empirical efforts should be directed towar...

  3. Linear multivariate evaluation models for spatial perception of soundscape.

    Science.gov (United States)

    Deng, Zhiyong; Kang, Jian; Wang, Daiwei; Liu, Aili; Kang, Joe Zhengyu

    2015-11-01

    Soundscape is a sound environment that emphasizes the awareness of auditory perception and social or cultural understandings. The case of spatial perception is significant to soundscape. However, previous studies on the auditory spatial perception of the soundscape environment have been limited. Based on 21 native binaural-recorded soundscape samples and a set of auditory experiments for subjective spatial perception (SSP), a study of the analysis among semantic parameters, the inter-aural-cross-correlation coefficient (IACC), A-weighted-equal sound-pressure-level (L(eq)), dynamic (D), and SSP is introduced to verify the independent effect of each parameter and to re-determine some of their possible relationships. The results show that the more noisiness the audience perceived, the worse spatial awareness they received, while the closer and more directional the sound source image variations, dynamics, and numbers of sound sources in the soundscape are, the better the spatial awareness would be. Thus, the sensations of roughness, sound intensity, transient dynamic, and the values of Leq and IACC have a suitable range for better spatial perception. A better spatial awareness seems to promote the preference slightly for the audience. Finally, setting SSPs as functions of the semantic parameters and Leq-D-IACC, two linear multivariate evaluation models of subjective spatial perception are proposed.

  4. The neural bases of spatial frequency processing during scene perception

    Science.gov (United States)

    Kauffmann, Louise; Ramanoël, Stephen; Peyrin, Carole

    2014-01-01

    Theories on visual perception agree that scenes are processed in terms of spatial frequencies. Low spatial frequencies (LSF) carry coarse information whereas high spatial frequencies (HSF) carry fine details of the scene. However, how and where spatial frequencies are processed within the brain remain unresolved questions. The present review addresses these issues and aims to identify the cerebral regions differentially involved in low and high spatial frequency processing, and to clarify their attributes during scene perception. Results from a number of behavioral and neuroimaging studies suggest that spatial frequency processing is lateralized in both hemispheres, with the right and left hemispheres predominantly involved in the categorization of LSF and HSF scenes, respectively. There is also evidence that spatial frequency processing is retinotopically mapped in the visual cortex. HSF scenes (as opposed to LSF) activate occipital areas in relation to foveal representations, while categorization of LSF scenes (as opposed to HSF) activates occipital areas in relation to more peripheral representations. Concomitantly, a number of studies have demonstrated that LSF information may reach high-order areas rapidly, allowing an initial coarse parsing of the visual scene, which could then be sent back through feedback into the occipito-temporal cortex to guide finer HSF-based analysis. Finally, the review addresses spatial frequency processing within scene-selective regions areas of the occipito-temporal cortex. PMID:24847226

  5. Spatial audio quality perception (part 2)

    DEFF Research Database (Denmark)

    Conetta, R.; Brookes, T.; Rumsey, F.

    2015-01-01

    location, envelopment, coverage angle, ensemble width, and spaciousness. They can also impact timbre, and changes to timbre can then influence spatial perception. Previously obtained data was used to build a regression model of perceived spatial audio quality in terms of spatial and timbral metrics...

  6. Action potential influences spatial perception: Evidence for genuine top-down effects on perception.

    Science.gov (United States)

    Witt, Jessica K

    2017-08-01

    The action-specific account of spatial perception asserts that a perceiver's ability to perform an action, such as hitting a softball or walking up a hill, impacts the visual perception of the target object. Although much evidence is consistent with this claim, the evidence has been challenged as to whether perception is truly impacted, as opposed to the responses themselves. These challenges have recently been organized as six pitfalls that provide a framework with which to evaluate the empirical evidence. Four case studies of action-specific effects are offered as evidence that meets the framework's high bar, and thus that demonstrates genuine perceptual effects. That action influences spatial perception is evidence that perceptual and action-related processes are intricately and bidirectionally linked.

  7. The role of visual spatial attention in audiovisual speech perception

    DEFF Research Database (Denmark)

    Andersen, Tobias; Tiippana, K.; Laarni, J.

    2009-01-01

    Auditory and visual information is integrated when perceiving speech, as evidenced by the McGurk effect in which viewing an incongruent talking face categorically alters auditory speech perception. Audiovisual integration in speech perception has long been considered automatic and pre-attentive b......Auditory and visual information is integrated when perceiving speech, as evidenced by the McGurk effect in which viewing an incongruent talking face categorically alters auditory speech perception. Audiovisual integration in speech perception has long been considered automatic and pre...... from each of the faces and from the voice on the auditory speech percept. We found that directing visual spatial attention towards a face increased the influence of that face on auditory perception. However, the influence of the voice on auditory perception did not change suggesting that audiovisual...... integration did not change. Visual spatial attention was also able to select between the faces when lip reading. This suggests that visual spatial attention acts at the level of visual speech perception prior to audiovisual integration and that the effect propagates through audiovisual integration...

  8. Selective spatial enhancement: Attentional spotlight size impacts spatial but not temporal perception.

    Science.gov (United States)

    Goodhew, Stephanie C; Shen, Elizabeth; Edwards, Mark

    2016-08-01

    An important but often neglected aspect of attention is how changes in the attentional spotlight size impact perception. The zoom-lens model predicts that a small ("focal") attentional spotlight enhances all aspects of perception relative to a larger ("diffuse" spotlight). However, based on the physiological properties of the two major classes of visual cells (magnocellular and parvocellular neurons) we predicted trade-offs in spatial and temporal acuity as a function of spotlight size. Contrary to both of these accounts, however, across two experiments we found that attentional spotlight size affected spatial acuity, such that spatial acuity was enhanced for a focal relative to a diffuse spotlight, whereas the same modulations in spotlight size had no impact on temporal acuity. This likely reflects the function of attention: to induce the high spatial resolution of the fovea in periphery, where spatial resolution is poor but temporal resolution is good. It is adaptive, therefore, for the attentional spotlight to enhance spatial acuity, whereas enhancing temporal acuity does not confer the same benefit.

  9. A vestibular sensation: probabilistic approaches to spatial perception.

    Science.gov (United States)

    Angelaki, Dora E; Klier, Eliana M; Snyder, Lawrence H

    2009-11-25

    The vestibular system helps maintain equilibrium and clear vision through reflexes, but it also contributes to spatial perception. In recent years, research in the vestibular field has expanded to higher-level processing involving the cortex. Vestibular contributions to spatial cognition have been difficult to study because the circuits involved are inherently multisensory. Computational methods and the application of Bayes theorem are used to form hypotheses about how information from different sensory modalities is combined together with expectations based on past experience in order to obtain optimal estimates of cognitive variables like current spatial orientation. To test these hypotheses, neuronal populations are being recorded during active tasks in which subjects make decisions based on vestibular and visual or somatosensory information. This review highlights what is currently known about the role of vestibular information in these processes, the computations necessary to obtain the appropriate signals, and the benefits that have emerged thus far.

  10. Mapping spatial patterns of people's risk perception of landslides

    Science.gov (United States)

    Kofler, Christian; Pedoth, Lydia; Elzbieta Stawinoga, Agnieszka; Schneiderbauer, Stefan

    2016-04-01

    The resilience of communities against natural hazards is largely influenced by how the individuals perceive risk. A good understanding of people's risk perception, awareness and hazard knowledge is crucial for developing and improving risk management and communication strategies between authorities and the affected population. A lot of research has been done in investigating the social aspects of risks to natural hazards by means of interviews or questionnaires. However, there is still a lack of research in the investigation of the influence of the spatial distance to a hazard event on peoples risk perception. While the spatial dimension of a natural hazard event is always assessed in works with a natural science approach, it is often neglected in works on social aspects of natural hazards. In the present study, we aimed to overcome these gaps by combining methods from different disciplines and assessing and mapping the spatial pattern of risk perception through multivariate statistical approaches based on empirical data from questionnaires. We will present results from a case study carried out in Badia, located in the Province of South Tyrol- Italy, where in December 2012 a landslide destroyed four residential buildings and led to the evacuation of 36 people. By means of questionnaires distributed to all adults living in the case study area we assessed people's risk perception and asked respondents to allocate their place of residence on a map of the case study area subdivided in 7 zones. Based on the data of the questionnaire results we developed a risk perception factor in order to express various assessed aspects linked to risk perception with one metric. We analyzed and mapped this factor according to the different zones reflecting the spatial distance to the event. Furthermore, a cluster analysis identified various risk behavior profiles within the population. We also investigated the spatial patterns of these risk profiles. We revealed that the residential

  11. Visual perception of spatial subjects

    International Nuclear Information System (INIS)

    Osterloh, K.R.S.; Ewert, U.

    2007-01-01

    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)

  12. 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)

  13. The Relative Importance of Spatial Versus Temporal Structure in the Perception of Biological Motion: An Event-Related Potential Study

    Science.gov (United States)

    Hirai, Masahiro; Hiraki, Kazuo

    2006-01-01

    We investigated how the spatiotemporal structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and temporal structure; scrambled spatial and normal temporal structure; normal spatial and scrambled temporal structure; and…

  14. Energy landscape and dynamics of brain activity during human bistable perception.

    Science.gov (United States)

    Watanabe, Takamitsu; Masuda, Naoki; Megumi, Fukuda; Kanai, Ryota; Rees, Geraint

    2014-08-28

    Individual differences in the structure of parietal and prefrontal cortex predict the stability of bistable visual perception. However, the mechanisms linking such individual differences in brain structures to behaviour remain elusive. Here we demonstrate a systematic relationship between the dynamics of brain activity, cortical structure and behaviour underpinning bistable perception. Using fMRI in humans, we find that the activity dynamics during bistable perception are well described as fluctuating between three spatially distributed energy minimums: visual-area-dominant, frontal-area-dominant and intermediate states. Transitions between these energy minimums predicted behaviour, with participants whose brain activity tend to reflect the visual-area-dominant state exhibiting more stable perception and those whose activity transits to frontal-area-dominant states reporting more frequent perceptual switches. Critically, these brain activity dynamics are correlated with individual differences in grey matter volume of the corresponding brain areas. Thus, individual differences in the large-scale dynamics of brain activity link focal brain structure with bistable perception.

  15. Influence of spatial perception abilities on reading in school-age children

    Directory of Open Access Journals (Sweden)

    Arnaud Saj

    2015-12-01

    Full Text Available Spatial perception abilities enable individuals to explore a visual field, to detect spatial position and to infer relationships between visual stimuli. Written words and text are conceptualized spatially along a horizontal mental line, but little is known about the way children develop these representations. The exact relationship between visuo-spatial perception and academic achievement has never been directly assessed. Therefore, our aim was to study the developmental trajectory of space perception abilities by assessing perceptual, attentional and memory components, the relationship between these abilities and reading achievement in school-age children. Forty-nine children aged between 6.5 and 11 years old were divided into four age groups and were assessed with visual bisection, visual search and visual memory location tasks. The results showed that the groups of older children, from the age of nine, improved significantly on the bisection and visual search tasks with respect to all visual fields, while the groups of younger children showed more errors in the left visual field (LVF. Performances on these tasks were correlated with reading level and age. Older children with a low reading score showed a LVF bias, similar to the youngest children. These results demonstrate how abnormal space perception might distort space representation and in turn affect reading and learning processes.

  16. An Adaptation-Induced Repulsion Illusion in Tactile Spatial Perception

    Directory of Open Access Journals (Sweden)

    Lux Li

    2017-06-01

    Full Text Available Following focal sensory adaptation, the perceived separation between visual stimuli that straddle the adapted region is often exaggerated. For instance, in the tilt aftereffect illusion, adaptation to tilted lines causes subsequently viewed lines with nearby orientations to be perceptually repelled from the adapted orientation. Repulsion illusions in the nonvisual senses have been less studied. Here, we investigated whether adaptation induces a repulsion illusion in tactile spatial perception. In a two-interval forced-choice task, participants compared the perceived separation between two point-stimuli applied on the forearms successively. Separation distance was constant on one arm (the reference and varied on the other arm (the comparison. In Experiment 1, we took three consecutive baseline measurements, verifying that in the absence of manipulation, participants’ distance perception was unbiased across arms and stable across experimental blocks. In Experiment 2, we vibrated a region of skin on the reference arm, verifying that this focally reduced tactile sensitivity, as indicated by elevated monofilament detection thresholds. In Experiment 3, we applied vibration between the two reference points in our distance perception protocol and discovered that this caused an illusory increase in the separation between the points. We conclude that focal adaptation induces a repulsion aftereffect illusion in tactile spatial perception. The illusion provides clues as to how the tactile system represents spatial information. The analogous repulsion aftereffects caused by adaptation in different stimulus domains and sensory systems may point to fundamentally similar strategies for dynamic sensory coding.

  17. Relative Contribution of Perception/Cognition and Language on Spatial Categorization

    Science.gov (United States)

    Choi, Soonja; Hattrup, Kate

    2012-01-01

    This study investigated the relative contribution of perception/cognition and language-specific semantics in nonverbal categorization of spatial relations. English and Korean speakers completed a video-based similarity judgment task involving containment, support, tight fit, and loose fit. Both perception/cognition and language served as resources…

  18. Multisensory perception of spatial orientation and self-motion

    NARCIS (Netherlands)

    de Winkel, K.N.

    2013-01-01

    The aim of this project was to improve our insight in how the brain combines information from different sensory systems (e.g. vestibular and visual system) into an integrated percept of self-motion and spatial orientation. Based on evidence from other research in different areas, such as hand-eye

  19. Relationships Among Peripheral and Central Electrophysiological Measures of Spatial and Spectral Selectivity and Speech Perception in Cochlear Implant Users.

    Science.gov (United States)

    Scheperle, Rachel A; Abbas, Paul J

    2015-01-01

    The ability to perceive speech is related to the listener's ability to differentiate among frequencies (i.e., spectral resolution). Cochlear implant (CI) users exhibit variable speech-perception and spectral-resolution abilities, which can be attributed in part to the extent of electrode interactions at the periphery (i.e., spatial selectivity). However, electrophysiological measures of peripheral spatial selectivity have not been found to correlate with speech perception. The purpose of this study was to evaluate auditory processing at the periphery and cortex using both simple and spectrally complex stimuli to better understand the stages of neural processing underlying speech perception. The hypotheses were that (1) by more completely characterizing peripheral excitation patterns than in previous studies, significant correlations with measures of spectral selectivity and speech perception would be observed, (2) adding information about processing at a level central to the auditory nerve would account for additional variability in speech perception, and (3) responses elicited with spectrally complex stimuli would be more strongly correlated with speech perception than responses elicited with spectrally simple stimuli. Eleven adult CI users participated. Three experimental processor programs (MAPs) were created to vary the likelihood of electrode interactions within each participant. For each MAP, a subset of 7 of 22 intracochlear electrodes was activated: adjacent (MAP 1), every other (MAP 2), or every third (MAP 3). Peripheral spatial selectivity was assessed using the electrically evoked compound action potential (ECAP) to obtain channel-interaction functions for all activated electrodes (13 functions total). Central processing was assessed by eliciting the auditory change complex with both spatial (electrode pairs) and spectral (rippled noise) stimulus changes. Speech-perception measures included vowel discrimination and the Bamford-Kowal-Bench Speech

  20. The upper spatial limit for perception of displacement is affected by preceding motion.

    Science.gov (United States)

    Stefanova, Miroslava; Mateeff, Stefan; Hohnsbein, Joachim

    2009-03-01

    The upper spatial limit D(max) for perception of apparent motion of a random dot pattern may be strongly affected by another, collinear, motion that precedes it [Mateeff, S., Stefanova, M., &. Hohnsbein, J. (2007). Perceived global direction of a compound of real and apparent motion. Vision Research, 47, 1455-1463]. In the present study this phenomenon was studied with two-dimensional motion stimuli. A random dot pattern moved alternately in the vertical and oblique direction (zig-zag motion). The vertical motion was of 1.04 degrees length; it was produced by three discrete spatial steps of the dots. Thereafter the dots were displaced by a single spatial step in oblique direction. Each motion lasted for 57ms. The upper spatial limit for perception of the oblique motion was measured under two conditions: the vertical component of the oblique motion and the vertical motion were either in the same or in opposite directions. It was found that the perception of the oblique motion was strongly influenced by the relative direction of the vertical motion that preceded it; in the "same" condition the upper spatial limit was much shorter than in the "opposite" condition. Decreasing the speed of the vertical motion reversed this effect. Interpretations based on networks of motion detectors and on Gestalt theory are discussed.

  1. Spatial and temporal variation in evacuee risk perception throughout the evacuation and return-entry process.

    Science.gov (United States)

    Siebeneck, Laura K; Cova, Thomas J

    2012-09-01

    Developing effective evacuation and return-entry plans requires understanding the spatial and temporal dimensions of risk perception experienced by evacuees throughout a disaster event. Using data gathered from the 2008 Cedar Rapids, Iowa Flood, this article explores how risk perception and location influence evacuee behavior during the evacuation and return-entry process. Three themes are discussed: (1) the spatial and temporal characteristics of risk perception throughout the evacuation and return-entry process, (2) the relationship between risk perception and household compliance with return-entry orders, and (3) the role social influences have on the timing of the return by households. The results indicate that geographic location and spatial variation of risk influenced household risk perception and compliance with return-entry plans. In addition, sociodemographic characteristics influenced the timing and characteristics of the return groups. The findings of this study advance knowledge of evacuee behavior throughout a disaster and can inform strategies used by emergency managers throughout the evacuation and return-entry process. © 2012 Society for Risk Analysis.

  2. [Development of spatial orientation during pilot training].

    Science.gov (United States)

    Ivanov, V V; Vorob'ev, O A; Snipkov, Iu Iu

    1988-01-01

    The problem of spatial orientation of pilots flying high-altitude aircraft is in the focus of present-day aviation medicine because of a growing number of accidents in the air. One of the productive lines of research is to study spatial orientation in terms of active formation and maintenance of its imagery in a complex environment. However investigators usually emphasize the role of visual (instrumental) information in the image construction, almost ignoring the sensorimotor component of spatial orientation. The theoretical analysis of the process of spatial orientation has facilitated the development of the concept assuming that the pattern of space perception changes with growing professional experience. The concept is based on an active approach to the essence, emergence, formation and variation in the pattern of sensory perception of space in man's consciousness. This concept asserts that as pilot's professional expertise increases, the pattern of spatial orientation becomes geocentric because a new system of spatial perception evolves which is a result of the development of a new (instrumental) type of motor activity in space. This finds expression in the fact that perception of spatial position inflight occurs when man has to resolve a new motor task--movement along a complex trajectory in the three-dimensional space onboard a flying vehicle. The meaningful structure of this problem which is to be implemented through controlling movements of the pilot acts as a factor that forms this new system of perception. All this underlies the arrangement of meaningful collection of instrumental data and detection of noninstrumental signals in the comprehensive perception of changes in the spatial position of a flying vehicle.

  3. Effects of hearing-aid dynamic range compression on spatial perception in a reverberant environment

    DEFF Research Database (Denmark)

    Hassager, Henrik Gert; Wiinberg, Alan; Dau, Torsten

    2017-01-01

    This study investigated the effects of fast-acting hearing-aid compression on normal-hearing and hearing-impaired listeners’ spatial perception in a reverberant environment. Three compression schemes—independent compression at each ear, linked compression between the two ears, and “spatially ideal......” compression operating solely on the dry source signal—were considered using virtualized speech and noise bursts. Listeners indicated the location and extent of their perceived sound images on the horizontal plane. Linear processing was considered as the reference condition. The results showed that both...... independent and linked compression resulted in more diffuse and broader sound images as well as internalization and image splits, whereby more image splits were reported for the noise bursts than for speech. Only the spatially ideal compression provided the listeners with a spatial percept similar...

  4. The spatially asymmetric cost of memory load on visual perception: transient stimulus-centered neglect.

    Science.gov (United States)

    Gozli, Davood G; Wilson, Kristin E; Ferber, Susanne

    2014-04-01

    Recent evidence suggests that visual working memory (VWM) load reduces performance accuracy on a concurrent visual recognition task, particularly for objects presented in the left hemifield. It has also been shown that high VWM load causes suppression of activity in the right temporoparietal junction (TPJ). Given the resemblance of VWM load effects to symptoms of unilateral neglect (i.e., impaired perception on the left side and lesion to the right TPJ), we investigated whether VWM load effects are restricted to the left side of space or extend to object-centered reference frames. In other words, akin to object-centered neglect, can high VWM load cause a perceptual cost in attending to the left side of the stimulus? We addressed this question using an object recognition task (Experiment 1) and a visual search task (Experiment 2) showing that this transient left-neglect can indeed be modulated by an object-centered frame of reference. These findings suggest that load-induced impairments of visual attention are spatially asymmetric and can emerge within multiple spatial reference frames. Therefore, the attentional consequences of high VWM load on conscious perception may serve as a useful model of unilateral perceptual neglect.

  5. Shape perception simultaneously up- and downregulates neural activity in the primary visual cortex.

    Science.gov (United States)

    Kok, Peter; de Lange, Floris P

    2014-07-07

    An essential part of visual perception is the grouping of local elements (such as edges and lines) into coherent shapes. Previous studies have shown that this grouping process modulates neural activity in the primary visual cortex (V1) that is signaling the local elements [1-4]. However, the nature of this modulation is controversial. Some studies find that shape perception reduces neural activity in V1 [2, 5, 6], while others report increased V1 activity during shape perception [1, 3, 4, 7-10]. Neurocomputational theories that cast perception as a generative process [11-13] propose that feedback connections carry predictions (i.e., the generative model), while feedforward connections signal the mismatch between top-down predictions and bottom-up inputs. Within this framework, the effect of feedback on early visual cortex may be either enhancing or suppressive, depending on whether the feedback signal is met by congruent bottom-up input. Here, we tested this hypothesis by quantifying the spatial profile of neural activity in V1 during the perception of illusory shapes using population receptive field mapping. We find that shape perception concurrently increases neural activity in regions of V1 that have a receptive field on the shape but do not receive bottom-up input and suppresses activity in regions of V1 that receive bottom-up input that is predicted by the shape. These effects were not modulated by task requirements. Together, these findings suggest that shape perception changes lower-order sensory representations in a highly specific and automatic manner, in line with theories that cast perception in terms of hierarchical generative models. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Spatial attention in written word perception.

    Science.gov (United States)

    Montani, Veronica; Facoetti, Andrea; Zorzi, Marco

    2014-01-01

    The role of attention in visual word recognition and reading aloud is a long debated issue. Studies of both developmental and acquired reading disorders provide growing evidence that spatial attention is critically involved in word reading, in particular for the phonological decoding of unfamiliar letter strings. However, studies on healthy participants have produced contrasting results. The aim of this study was to investigate how the allocation of spatial attention may influence the perception of letter strings in skilled readers. High frequency words (HFWs), low frequency words and pseudowords were briefly and parafoveally presented either in the left or the right visual field. Attentional allocation was modulated by the presentation of a spatial cue before the target string. Accuracy in reporting the target string was modulated by the spatial cue but this effect varied with the type of string. For unfamiliar strings, processing was facilitated when attention was focused on the string location and hindered when it was diverted from the target. This finding is consistent the assumptions of the CDP+ model of reading aloud, as well as with familiarity sensitivity models that argue for a flexible use of attention according with the specific requirements of the string. Moreover, we found that processing of HFWs was facilitated by an extra-large focus of attention. The latter result is consistent with the hypothesis that a broad distribution of attention is the default mode during reading of familiar words because it might optimally engage the broad receptive fields of the highest detectors in the hierarchical system for visual word recognition.

  7. Spatial attention in written word perception

    Directory of Open Access Journals (Sweden)

    Veronica eMontani

    2014-02-01

    Full Text Available The role of attention in visual word recognition and reading aloud is a long debated issue. Studies of both developmental and acquired reading disorders provide growing evidence that spatial attention is critically involved in word reading, in particular for the phonological decoding of unfamiliar letter strings. However, studies on healthy participants have produced contrasting results. The aim of this study was to investigate how the allocation of spatial attention may influence the perception of letter strings in skilled readers. High frequency words, low frequency words and pseudowords were briefly and parafoveally presented either in the left or the right visual field. Attentional allocation was modulated by the presentation of a spatial cue before the target string. Accuracy in reporting the target string was modulated by the spatial cue but this effect varied with the type of string. For unfamiliar strings, processing was facilitated when attention was focused on the string location and hindered when it was diverted from the target. This finding is consistent the assumptions of the CDP+ model of reading aloud, as well as with familiarity sensitivity models that argue for a flexible use of attention according with the specific requirements of the string. Moreover, we found that processing of high-frequency words was facilitated by an extra-large focus of attention. The latter result is consistent with the hypothesis that a broad distribution of attention is the default mode during reading of familiar words because it might optimally engage the broad receptive fields of the highest detectors in the hierarchical system for visual word recognition.

  8. Investigating Effect of Origami-Based Instruction on Elementary Students' Spatial Skills and Perceptions

    Science.gov (United States)

    Cakmak, Sedanur; Isiksal, Mine; Koc, Yusuf

    2014-01-01

    The authors' purpose was to investigate the effect of origami-based instruction on elementary students' spatial ability. The students' self-reported perceptions related to the origami-based instruction were also examined. Data was collected via purposive sampling techniques from students enrolled in a private elementary school. A spatial ability…

  9. Common mechanisms of spatial attention in memory and perception: a tactile dual-task study.

    Science.gov (United States)

    Katus, Tobias; Andersen, Søren K; Müller, Matthias M

    2014-03-01

    Orienting attention to locations in mnemonic representations engages processes that functionally and anatomically overlap the neural circuitry guiding prospective shifts of spatial attention. The attention-based rehearsal account predicts that the requirement to withdraw attention from a memorized location impairs memory accuracy. In a dual-task study, we simultaneously presented retro-cues and pre-cues to guide spatial attention in short-term memory (STM) and perception, respectively. The spatial direction of each cue was independent of the other. The locations indicated by the combined cues could be compatible (same hand) or incompatible (opposite hands). Incompatible directional cues decreased lateralized activity in brain potentials evoked by visual cues, indicating interference in the generation of prospective attention shifts. The detection of external stimuli at the prospectively cued location was impaired when the memorized location was part of the perceptually ignored hand. The disruption of attention-based rehearsal by means of incompatible pre-cues reduced memory accuracy and affected encoding of tactile test stimuli at the retrospectively cued hand. These findings highlight the functional significance of spatial attention for spatial STM. The bidirectional interactions between both tasks demonstrate that spatial attention is a shared neural resource of a capacity-limited system that regulates information processing in internal and external stimulus representations.

  10. Effect of gel texture and sucrose spatial distribution on sweetness perception

    NARCIS (Netherlands)

    Mosca, A.C.; Velde, van de F.; Bult, J.H.F.; Boekel, van M.A.J.S.; Stieger, M.A.

    2012-01-01

    Layered gels differing in mechanical and breakdown properties (soft, medium and hard gels) and in the distribution of sucrose in the matrix (homogeneous and inhomogeneous distributions) were used to investigate the effects of texture and spatial distribution of sucrose on sweetness perception.

  11. Photography activities for developing students’ spatial orientation and spatial visualization

    Science.gov (United States)

    Hendroanto, Aan; van Galen, Frans; van Eerde, D.; Prahmana, R. C. I.; Setyawan, F.; Istiandaru, A.

    2017-12-01

    Spatial orientation and spatial visualization are the foundation of students’ spatial ability. They assist students’ performance in learning mathematics, especially geometry. Considering its importance, the present study aims to design activities to help young learners developing their spatial orientation and spatial visualization ability. Photography activity was chosen as the context of the activity to guide and support the students. This is a design research study consisting of three phases: 1) preparation and designing 2) teaching experiment, and 3) retrospective analysis. The data is collected by tests and interview and qualitatively analyzed. We developed two photography activities to be tested. In the teaching experiments, 30 students of SD Laboratorium UNESA, Surabaya were involved. The results showed that the activities supported the development of students’ spatial orientation and spatial visualization indicated by students’ learning progresses, answers, and strategies when they solved the problems in the activities.

  12. Multisensory Rehabilitation Training Improves Spatial Perception in Totally but Not Partially Visually Deprived Children

    Directory of Open Access Journals (Sweden)

    Giulia Cappagli

    2017-10-01

    Full Text Available Since it has been shown that spatial development can be delayed in blind children, focused sensorimotor trainings that associate auditory and motor information might be used to prevent the risk of spatial-related developmental delays or impairments from an early age. With this aim, we proposed a new technological device based on the implicit link between action and perception: ABBI (Audio Bracelet for Blind Interaction is an audio bracelet that produces a sound when a movement occurs by allowing the substitution of the visuo-motor association with a new audio-motor association. In this study, we assessed the effects of an extensive but entertaining sensorimotor training with ABBI on the development of spatial hearing in a group of seven 3–5 years old children with congenital blindness (n = 2; light perception or no perception of light or low vision (n = 5; visual acuity range 1.1–1.7 LogMAR. The training required the participants to play several spatial games individually and/or together with the psychomotor therapist 1 h per week for 3 months: the spatial games consisted of exercises meant to train their ability to associate visual and motor-related signals from their body, in order to foster the development of multisensory processes. We measured spatial performance by asking participants to indicate the position of one single fixed (static condition or moving (dynamic condition sound source on a vertical sensorized surface. We found that spatial performance of congenitally blind but not low vision children is improved after the training, indicating that early interventions with the use of science-driven devices based on multisensory capabilities can provide consistent advancements in therapeutic interventions, improving the quality of life of children with visual disability.

  13. Influence of the Quality of Consumer Headphones in the Perception of Spatial Audio

    Directory of Open Access Journals (Sweden)

    Pablo Gutierrez-Parera

    2016-04-01

    Full Text Available High quality headphones can generate a realistic sound immersion reproducing binaural recordings. However, most people commonly use consumer headphones of inferior quality, as the ones provided with smartphones or music players. Factors, such as weak frequency response, distortion and the sensitivity disparity between the left and right transducers could be some of the degrading factors. In this work, we are studying how these factors affect spatial perception. To this purpose, a series or perceptual tests have been carried out with a virtual headphone listening test methodology. The first experiment focuses on the analysis of how the disparity of sensitivity between the two transducers affects the final result. The second test studies the influence of the frequency response relating quality and spatial impression. The third test analyzes the effects of distortion using a Volterra kernels scheme for the simulation of the distortion using convolutions. Finally, the fourth tries to relate the quality of the frequency response with the accuracy on azimuth localization. The conclusions of the experiments are: the disparity between both transducers can affect the localization of the source; the perception of quality and spatial impression has a high correlation; the distortion produced by the range of headphones tested at a fixed level does not affect the perception of binaural sound; and that some frequency bands have an important role in the front-back confusions.

  14. A Common Representation of Spatial Features Drives Action and Perception

    DEFF Research Database (Denmark)

    Christiansen, Jens H; Christensen, Jeppe Høy; Grünbaum, Thor

    2014-01-01

    Spatial features of an object can be specified using two different response types: either by use of symbols or motorically by directly acting upon the object. Is this response dichotomy reflected in a dual representation of the visual world: one for perception and one for action? Previously, symb...... of matching object-processing characteristics is also in agreement with the idea of a common representation driving both response types....

  15. Entrepreneurial Activity, Self-Perception and Gender

    OpenAIRE

    Verheul, Ingrid; Uhlaner, Lorraine; Thurik, Roy

    2002-01-01

    textabstractDrawing on Bem's psychological theory of self-perception, this paper presents and tests a model that examines the impact of gender and entrepreneurial activity on entrepreneurial self-perception. Based on a sample of alumni of a large Midwestern U.S. university, regression techniques are used to identify those activities associated with self-perceptions of entrepreneurship, as well as direct and indirect effects of gender. Results support the model of both direct and indirect effe...

  16. Dynamic Stimuli And Active Processing In Human Visual Perception

    Science.gov (United States)

    Haber, Ralph N.

    1990-03-01

    Theories of visual perception traditionally have considered a static retinal image to be the starting point for processing; and has considered processing both to be passive and a literal translation of that frozen, two dimensional, pictorial image. This paper considers five problem areas in the analysis of human visually guided locomotion, in which the traditional approach is contrasted to newer ones that utilize dynamic definitions of stimulation, and an active perceiver: (1) differentiation between object motion and self motion, and among the various kinds of self motion (e.g., eyes only, head only, whole body, and their combinations); (2) the sources and contents of visual information that guide movement; (3) the acquisition and performance of perceptual motor skills; (4) the nature of spatial representations, percepts, and the perceived layout of space; and (5) and why the retinal image is a poor starting point for perceptual processing. These newer approaches argue that stimuli must be considered as dynamic: humans process the systematic changes in patterned light when objects move and when they themselves move. Furthermore, the processing of visual stimuli must be active and interactive, so that perceivers can construct panoramic and stable percepts from an interaction of stimulus information and expectancies of what is contained in the visual environment. These developments all suggest a very different approach to the computational analyses of object location and identification, and of the visual guidance of locomotion.

  17. Increased fusiform area activation in schizophrenia during processing of spatial frequency-degraded faces, as revealed by fMRI.

    Science.gov (United States)

    Silverstein, S M; All, S D; Kasi, R; Berten, S; Essex, B; Lathrop, K L; Little, D M

    2010-07-01

    People with schizophrenia demonstrate perceptual organization impairments, and these are thought to contribute to their face processing difficulties. We examined the neural substrates of emotionally neutral face processing in schizophrenia by investigating neural activity under three stimulus conditions: faces characterized by the full spectrum of spatial frequencies, faces with low spatial frequency information removed [high spatial frequency (HSF) condition], and faces with high spatial frequency information removed [low spatial frequency (LSF) condition]. Face perception in the HSF condition is more reliant on local feature processing whereas perception in the LSF condition requires greater reliance on global form processing. Past studies of perceptual organization in schizophrenia indicate that patients perform relatively more poorly with degraded stimuli but also that, when global information is absent, patients may perform better than controls because of their relatively increased ability to initially process individual features. Therefore, we hypothesized that people with schizophrenia (n=14) would demonstrate greater face processing difficulties than controls (n=13) in the LSF condition, whereas they would demonstrate a smaller difference or superior performance in the HSF condition. In a gender-discrimination task, behavioral data indicated high levels of accuracy for both groups, with a trend toward an interaction involving higher patient performance in the HSF condition and poorer patient performance in the LSF condition. Patients demonstrated greater activity in the fusiform gyrus compared to controls in both degraded conditions. These data suggest that impairments in basic integration abilities may be compensated for by relatively increased activity in this region.

  18. Spatially Rearranged Object Parts Can Facilitate Perception of Intact Whole Objects

    Directory of Open Access Journals (Sweden)

    Laura eCacciamani

    2014-05-01

    Full Text Available The familiarity of an object depends on the spatial arrangement of its parts; when the parts are spatially rearranged, they form a novel, unrecognizable configuration. Yet the same collection of parts comprises both the familiar and novel configuration. Is it possible that the collection of familiar parts activates a representation of the intact familiar configuration even when they are spatially rearranged? We presented novel configurations as primes before test displays that assayed effects on figure-ground perception from memories of intact familiar objects. In our test displays, two equal-area regions shared a central border; one region depicted a portion of a familiar object. Previous research with such displays has shown that participants are more likely to perceive the region depicting a familiar object as the figure and the abutting region as its ground when the familiar object is depicted in its upright orientation rather than upside down. The novel primes comprised either the same or a different collection of parts as the familiar object in the test display (part-rearranged and control primes, respectively. We found that participants were more likely to perceive the familiar region as figure in upright vs. inverted displays following part-rearranged primes but not control primes. Thus, priming with a novel configuration comprising the same familiar parts as the upcoming figure-ground display facilitated orientation-dependent effects of object memories on figure assignment. Similar results were obtained when the spatially rearranged collection of parts was suggested on the groundside of the prime’s border, suggesting that familiar parts in novel configurations access the representation of their corresponding intact whole object before figure assignment. These data demonstrate that familiar parts access memories of familiar objects even when they are arranged in a novel configuration.

  19. Spatially rearranged object parts can facilitate perception of intact whole objects.

    Science.gov (United States)

    Cacciamani, Laura; Ayars, Alisabeth A; Peterson, Mary A

    2014-01-01

    The familiarity of an object depends on the spatial arrangement of its parts; when the parts are spatially rearranged, they form a novel, unrecognizable configuration. Yet the same collection of parts comprises both the familiar and novel configuration. Is it possible that the collection of familiar parts activates a representation of the intact familiar configuration even when they are spatially rearranged? We presented novel configurations as primes before test displays that assayed effects on figure-ground perception from memories of intact familiar objects. In our test displays, two equal-area regions shared a central border; one region depicted a portion of a familiar object. Previous research with such displays has shown that participants are more likely to perceive the region depicting a familiar object as the figure and the abutting region as its ground when the familiar object is depicted in its upright orientation rather than upside down. The novel primes comprised either the same or a different collection of parts as the familiar object in the test display (part-rearranged and control primes, respectively). We found that participants were more likely to perceive the familiar region as figure in upright vs. inverted displays following part-rearranged primes but not control primes. Thus, priming with a novel configuration comprising the same familiar parts as the upcoming figure-ground display facilitated orientation-dependent effects of object memories on figure assignment. Similar results were obtained when the spatially rearranged collection of parts was suggested on the groundside of the prime's border, suggesting that familiar parts in novel configurations access the representation of their corresponding intact whole object before figure assignment. These data demonstrate that familiar parts access memories of familiar objects even when they are arranged in a novel configuration.

  20. Embodied perception: A proposal to reconcile affordance and spatial perception

    NARCIS (Netherlands)

    Canal Bruland, R.; van der Kamp, J.

    2015-01-01

    Proffitt's embodied approach to perception is deeply indebted to Gibson's ecological approach to visual perception, in particular the idea that the primary objects of perception are affordances or what the environment offers for action. Yet, rather than directly addressing affordance perception,

  1. Area PEc Neurons Use a Multiphasic Pattern of Activity to Signal the Spatial Properties of Optic Flow

    Directory of Open Access Journals (Sweden)

    Milena Raffi

    2017-01-01

    Full Text Available The cortical representation of visual perception requires the integration of several-signal processing distributed across many cortical areas, but the neural substrates of such perception are largely unknown. The type of firing pattern exhibited by single neurons is an important indicator of dynamic circuitry within or across cortical areas. Neurons in area PEc are involved in the spatial mapping of the visual field; thus, we sought to analyze the firing pattern of activity of PEc optic flow neurons to shed some light on the cortical processing of visual signals. We quantified the firing activity of 152 optic flow neurons using a spline interpolation function, which allowed determining onset, end, and latency of each neuronal response. We found that many PEc neurons showed multiphasic activity, which is strictly related to the position of the eye and to the position of the focus of expansion (FOE of the flow field. PEc neurons showed a multiphasic activity comprised of excitatory phases interspersed with inhibitory pauses. This phasic pattern seems to be a very efficient way to signal the spatial location of visual stimuli, given that the same neuron sends different firing patterns according to a specific combination of FOE/eye position.

  2. Benefit of spatial filtering for visual perception with a subretinal implant.

    Science.gov (United States)

    Rieger, Viola; Aryan, Naser Pour; Brendler, Christian; Rothermel, Albrecht

    2014-01-01

    Subretinal implants have proven to be capable of restoring vision to patients suffering from hereditary retinal degeneration diseases like retinitis pigmentosa and cone-rod dystrophy. Although they already provide basic visual perception, there is still much room for improvement in this field. Effects like electric field interference limit the visual acuity and may be the cause of the perceived vision to be blurred. This influence could be reduced by means of highpass spatial filtering. In this paper, based on the available reports about the visual perception parameters from the patients using the alpha-IMS subretinal implant, a model for the blurring effect of the patients retina is proposed. On this basis, highpass filters are suggested which will compensate the obscuring effect of the stimulator device plus retina system to some extent.

  3. Entrepreneurial Activity, Self-Perception and Gender

    NARCIS (Netherlands)

    I. Verheul (Ingrid); L.M. Uhlaner (Lorraine); A.R. Thurik (Roy)

    2002-01-01

    textabstractDrawing on Bem's psychological theory of self-perception, this paper presents and tests a model that examines the impact of gender and entrepreneurial activity on entrepreneurial self-perception. Based on a sample of alumni of a large Midwestern U.S. university, regression techniques are

  4. RELIABILITY OF THE DYNAMIC OCCUPATIONAL THERAPY COGNITIVE ASSESSMENT FOR CHILDREN (DOTCA-CH: THAI VERSION OF ORIENTATION, SPATIAL PERCEPTION, AND THINKING OPERATIONS SUBTESTS

    Directory of Open Access Journals (Sweden)

    Suchitporn Lersilp

    2014-06-01

    Full Text Available The Dynamic Occupational Therapy Cognitive Assessment for Children (DOTCA-Ch is a tool for finding out about cognitive problems in school-aged children. However, the DOTCA-Ch was developed in English for Western children. For this reason, it’s not appropriate for Thai children because of the differences of culture and language. The objectives of this study were aimed at translating the DOTCA-Ch in Orientation, Spatial Perception, and Thinking Operations subtests to a Thai version with a World Health Organization back-translation process, and to examine its internal consistency, inter-rater reliability and test-retest reliability. The participants consisted of 38 intellectually impaired and learning disabled individuals between the ages of 6–12. Results from this study revealed high internal consistency in the Orientation subtest (α=.83 Spatial Perception subtest (α=.82 and Thinking Operations subtest (α=.82, high inter-rater reliability in the Orientation subtest (ICC =.83, Spatial Perception subtest (ICC =.84 and Thinking Operations subtest (ICC =.74 and high test-retest reliability in the Orientation subtest (ICC =.84 Spatial Perception subtest (ICC =.86 and Thinking Operations subtest (ICC =.85. These results indicate that the Thai version of the DOTCA-Ch in Orientation, Spatial Perception, and Thinking Operations subtests  might be used as an appropriate assessment tool for Thai children, based on psychometric evidence including internal consistency, inter-rater reliability and test-retest reliability. However, additional study of other psychometric properties, including, predictive validity, concurrent reliability, and inter-rater reliability during the mediation process of this assessment tool needs to be carried out.

  5. INVESTIGATING THE EFFECT OF EMPLOYING IMMERSIVE VIRTUAL ENVIRONMENT ON ENHANCING SPATIAL PERCEPTION WITHIN DESIGN PROCESS

    Directory of Open Access Journals (Sweden)

    Rawan Taisser Abu Alatta

    2017-07-01

    Full Text Available The recent developments in Information Technology (IT and digital media have introduced new opportunities to design studio and new dimensions to design and architecture. The current research studies how the immersion of Virtual Reality (VR in architectural design studio affects spatial perception through the design process. The aim of this study is to investigate the effect of using such environments on changing the way how to design for human experience: how it will improve students' spatial understanding of Three Dimensions (3D volumes, and how it will enhance their imagination, enrich their creativity and promote their ability to experience their design's sensations. This study hypothesizes that using an immersive virtual environment in design studio will empower students' imaginations and give them the ability to understand and experience their ideas. It will give them the opportunity to check their design's validity with greater 3D exploration, understanding and comprehension of spatial volumes.  Within a framework of an experimental design research, a series of experiments was conducted to evaluate what had been assumed.  The research used teaching, monitoring, explanatory observation and evaluation methods. The results showed that VR can not only enhance spatial perception and improve the design, but also it can affect the design process and make changes in the architectural design way of thinking. It can help designers to incorporate human experience within the design process.

  6. Is attention based on spatial contextual memory preferentially guided by low spatial frequency signals?

    Science.gov (United States)

    Patai, Eva Zita; Buckley, Alice; Nobre, Anna Christina

    2013-01-01

    A popular model of visual perception states that coarse information (carried by low spatial frequencies) along the dorsal stream is rapidly transmitted to prefrontal and medial temporal areas, activating contextual information from memory, which can in turn constrain detailed input carried by high spatial frequencies arriving at a slower rate along the ventral visual stream, thus facilitating the processing of ambiguous visual stimuli. We were interested in testing whether this model contributes to memory-guided orienting of attention. In particular, we asked whether global, low-spatial frequency (LSF) inputs play a dominant role in triggering contextual memories in order to facilitate the processing of the upcoming target stimulus. We explored this question over four experiments. The first experiment replicated the LSF advantage reported in perceptual discrimination tasks by showing that participants were faster and more accurate at matching a low spatial frequency version of a scene, compared to a high spatial frequency version, to its original counterpart in a forced-choice task. The subsequent three experiments tested the relative contributions of low versus high spatial frequencies during memory-guided covert spatial attention orienting tasks. Replicating the effects of memory-guided attention, pre-exposure to scenes associated with specific spatial memories for target locations (memory cues) led to higher perceptual discrimination and faster response times to identify targets embedded in the scenes. However, either high or low spatial frequency cues were equally effective; LSF signals did not selectively or preferentially contribute to the memory-driven attention benefits to performance. Our results challenge a generalized model that LSFs activate contextual memories, which in turn bias attention and facilitate perception.

  7. Obama cares about visuo-spatial attention: perception of political figures moves attention and determines gaze direction.

    Science.gov (United States)

    Mills, Mark; Smith, Kevin B; Hibbing, John R; Dodd, Michael D

    2015-02-01

    Processing an abstract concept such as political ideology by itself is difficult but becomes easier when a background situation contextualizes it. Political ideology within American politics, for example, is commonly processed using space metaphorically, i.e., the political "left" and "right" (referring to Democrat and Republican views, respectively), presumably to provide a common metric to which abstract features of ideology can be grounded and understood. Commonplace use of space as metaphor raises the question of whether an inherently non-spatial stimulus (e.g., picture of the political "left" leader, Barack Obama) can trigger a spatially-specific response (e.g., attentional bias toward "left" regions of the visual field). Accordingly, pictures of well-known Democrats and Republicans were presented as central cues in peripheral target detection (Experiment 1) and saccadic free-choice (Experiment 2) tasks to determine whether perception of stimuli lacking a direct association with physical space nonetheless induce attentional and oculomotor biases in the direction compatible with the ideological category of the cue (i.e., Democrat/left and Republican/right). In Experiment 1, target detection following presentation of a Democrat (Republican) was facilitated for targets appearing to the left (right). In Experiment 2, participants were more likely to look left (right) following presentation of a Democrat (Republican). Thus, activating an internal representation of political ideology induced a shift of attention and biased choice of gaze direction in a spatially-specific manner. These findings demonstrate that the link between conceptual processing and spatial attention can be totally arbitrary, with no reference to physical or symbolic spatial information. Published by Elsevier B.V.

  8. Spatial Narrative and Perception of Space in Historical and Contemporary Architectural Compositions

    Directory of Open Access Journals (Sweden)

    Gytis Oržikauskas

    2013-10-01

    Full Text Available One of the most important features in historical architectural compositions is geometrical rendition of architectural space and volume. This feature was highlighted in terms of architecture of Modernism. According to the theory of modern architecture and Geschtalt Psychology, elementary geometrical forms and main spatial features were underlined and accepted as anthropomorphic principle of architecture. Even today main spatial characteristics are accepted as a key principle of architectural composition. However, architects and critics of contemporary – post-modern and deconstructive – architecture emphasize the value of architectural narrative achieved not only through perception of space, but also by its relationship to social and cultural meanings and subtext of architecture. A narrative, as architectural feature, is realized in some compositions of the deconstructivist and postmodern architecture, both worldwide and in Lithuania

  9. Revisiting the role of language in spatial cognition: Categorical perception of spatial relations in English and Korean speakers.

    Science.gov (United States)

    Holmes, Kevin J; Moty, Kelsey; Regier, Terry

    2017-12-01

    The spatial relation of support has been regarded as universally privileged in nonlinguistic cognition and immune to the influence of language. English, but not Korean, obligatorily distinguishes support from nonsupport via basic spatial terms. Despite this linguistic difference, previous research suggests that English and Korean speakers show comparable nonlinguistic sensitivity to the support/nonsupport distinction. Here, using a paradigm previously found to elicit cross-language differences in color discrimination, we provide evidence for a difference in sensitivity to support/nonsupport between native English speakers and native Korean speakers who were late English learners and tested in a context that privileged Korean. Whereas the former group showed categorical perception (CP) when discriminating spatial scenes capturing the support/nonsupport distinction, the latter did not. An additional group of native Korean speakers-relatively early English learners tested in an English-salient context-patterned with the native English speakers in showing CP for support/nonsupport. These findings suggest that obligatory marking of support/nonsupport in one's native language can affect nonlinguistic sensitivity to this distinction, contra earlier findings, but that such sensitivity may also depend on aspects of language background and the immediate linguistic context.

  10. Student Perceptions of Social Justice and Social Justice Activities

    Science.gov (United States)

    Torres-Harding, Susan R.; Steele, Cheronda; Schulz, Erica; Taha, Farah; Pico, Chantal

    2014-01-01

    Encouraging students to engage in activities that actively seek to promote social justice is a goal of many educators. This study analyzed college student perceptions around social justice and related activities in a medium-sized, urban university in the United States. Students' open-ended responses to questions assessing their perceptions of…

  11. Modulating Spatial Processes and Navigation via Transcranial Electrical Stimulation: A Mini Review

    Directory of Open Access Journals (Sweden)

    Tad T. Brunyé

    2018-01-01

    Full Text Available Transcranial electrical stimulation (tES uses low intensity current to alter neuronal activity in superficial cortical regions, and has gained popularity as a tool for modulating several aspects of perception and cognition. This mini-review article provides an overview of tES and its potential for modulating spatial processes underlying successful navigation, including spatial attention, spatial perception, mental rotation and visualization. Also considered are recent advances in empirical research and computational modeling elucidating several stable cortical-subcortical networks with dynamic involvement in spatial processing and navigation. Leveraging these advances may prove valuable for using tES, particularly transcranial direct and alternating current stimulation (tDCS/tACS, to indirectly target subcortical brain regions by altering neuronal activity in distant yet functionally connected cortical areas. We propose future research directions to leverage these advances in human neuroscience.

  12. The relationship between subjective perception and the psychological effects of patients in spatial isolation

    Directory of Open Access Journals (Sweden)

    Ibert, Fabienne

    2017-08-01

    Full Text Available Background: Spatial isolation is a common infection control measure, but negative psychological effects are often neglected. We investigated which factors influence the perception of single room isolated patients.Methods: In the present correlative cross-sectional study, 32 isolated patients have been interviewed within three departments of the Heidelberg University Hospital, one of Germany’s largest hospitals. The following questionnaires were used: 10-Item Big Five Inventory (BFI-10, Positive and Negative Affect Schedule (PANAS, Hospital Anxiety and Depression Scale (HADS and a self-developed questionnaire to evaluate the individual experience of isolation. Data were analysed using correlation and regression analysis.Results: A significant positive correlation was found between the isolation period and anxiety (r=.42, p<.05. Interestingly, a significant positive correlation was demonstrated between the duration of contact to nursing staff and negative daydreaming (r=.89, p<.01. The activity watching television was associated with higher levels of anxiety (r=.38, p<.05. Surfing the internet had a positive relationship with thinking about beautiful things (r=.41, p<.05. Conclusions: Our study results have implications how to improve the psychological situation of patients during spatial isolation. Contact between nursing staff and patients is crucial, since this contact significantly associated with negative daydreaming, probably due to increased neediness of emotional and physical care in some patients. The duration of the isolation has an influence on the experience of anxiety. Activities to cope with the isolation, however, not always have positive effects on the well-being of the patient.

  13. [The impact of psilocybin on visual perception and spatial orientation--neuropsychological approach].

    Science.gov (United States)

    Jastrzebski, Mikolaj; Bala, Aleksandra

    2013-01-01

    Psilocybin is a substance of natural origin, occurring in hallucinogenic mushrooms (most common in the Psilocybe family). After its synthesis in 1958 research began on its psychoactive properties, particularly strong effects on visual perception and spatial orientation. Due to the very broad spectrum of psilocybin effects research began on the different ranges of its actions--including the effect on physiological processes (such as eye saccada movements). Neuro-imaging and neurophysiological research (positron emission tomography-PET and electroencephalography-EEG), indicate a change in the rate of metabolism of the brain and desync cerebral hemispheres. Experimental studies show the changes in visual perception and distortion from psilocybin in the handwriting style of patients examined. There are widely described subjective experiences reported by the subjects. There are also efforts to apply testing via questionnaire on people under the influence of psilocybin, in the context of the similarity of psilocybin-induced state to the initial stages of schizophrenia, as well as research aimed at creating an 'artificial' model of the disease.

  14. Old cortex, new contexts: Re-purposing spatial perception for social cognition

    Directory of Open Access Journals (Sweden)

    Carolyn eParkinson

    2013-10-01

    Full Text Available Much of everyday mental life involves information that we cannot currently perceive directly, from contemplating the strengths of friendships to reasoning about the contents of other minds. Despite their primacy to everyday human functioning, and in particular, to human sociality, the mechanisms that support abstract thought are poorly understood. An explanatory framework that has gained traction recently in cognitive neuroscience is exaptation, or the re-purposing of evolutionarily old circuitry to carry out new functions. We argue for the utility of applying this concept to social cognition. Convergent behavioral and neuroscientific evidence suggests that humans co-opt mechanisms originally devoted to spatial perception for more abstract domains of cognition (e.g., temporal reasoning. Preliminary evidence suggests that some aspects of social cognition also involve the exaptation of substrates originally evolved for processing physical space. We discuss the potential for future work to test more directly if cortical substrates for spatial processing were exapted for social cognition, and in so doing, to improve our understanding of how humans evolved mechanisms for navigating an exceptionally complex social world.

  15. EGFR Activation by Spatially Restricted Ligands

    National Research Council Canada - National Science Library

    Clouse, Katherine N; Goodrich, Jennifer S

    2006-01-01

    ...) activity has been associated with an increased prognosis of breast cancer. During cogenesis in Drosophila melanogaster local Egfr activation by the spatially-restricted TGFalpha-like ligand Gurken (Grk...

  16. EGFR Activation by Spatially Restricted Ligands

    National Research Council Canada - National Science Library

    Goodrich, Jennifer S

    2005-01-01

    ...) activity has been associated with an increased prognosis of breast cancer. During oogenesis in Drosophila melanogaster, local EGFR activation by the spatially restricted TGF alpha-like ligand, Gurken (Grk...

  17. Interactive activation and mutual constraint satisfaction in perception and cognition.

    Science.gov (United States)

    McClelland, James L; Mirman, Daniel; Bolger, Donald J; Khaitan, Pranav

    2014-08-01

    In a seminal 1977 article, Rumelhart argued that perception required the simultaneous use of multiple sources of information, allowing perceivers to optimally interpret sensory information at many levels of representation in real time as information arrives. Building on Rumelhart's arguments, we present the Interactive Activation hypothesis-the idea that the mechanism used in perception and comprehension to achieve these feats exploits an interactive activation process implemented through the bidirectional propagation of activation among simple processing units. We then examine the interactive activation model of letter and word perception and the TRACE model of speech perception, as early attempts to explore this hypothesis, and review the experimental evidence relevant to their assumptions and predictions. We consider how well these models address the computational challenge posed by the problem of perception, and we consider how consistent they are with evidence from behavioral experiments. We examine empirical and theoretical controversies surrounding the idea of interactive processing, including a controversy that swirls around the relationship between interactive computation and optimal Bayesian inference. Some of the implementation details of early versions of interactive activation models caused deviation from optimality and from aspects of human performance data. More recent versions of these models, however, overcome these deficiencies. Among these is a model called the multinomial interactive activation model, which explicitly links interactive activation and Bayesian computations. We also review evidence from neurophysiological and neuroimaging studies supporting the view that interactive processing is a characteristic of the perceptual processing machinery in the brain. In sum, we argue that a computational analysis, as well as behavioral and neuroscience evidence, all support the Interactive Activation hypothesis. The evidence suggests that

  18. Using neuronal populations to study the mechanisms underlying spatial and feature attention

    Science.gov (United States)

    Cohen, Marlene R.; Maunsell, John H.R.

    2012-01-01

    Summary Visual attention affects both perception and neuronal responses. Whether the same neuronal mechanisms mediate spatial attention, which improves perception of attended locations, and non-spatial forms of attention has been a subject of considerable debate. Spatial and feature attention have similar effects on individual neurons. Because visual cortex is retinotopically organized, however, spatial attention can co-modulate local neuronal populations, while feature attention generally requires more selective modulation. We compared the effects of feature and spatial attention on local and spatially separated populations by recording simultaneously from dozens of neurons in both hemispheres of V4. Feature and spatial attention affect the activity of local populations similarly, modulating both firing rates and correlations between pairs of nearby neurons. However, while spatial attention appears to act on local populations, feature attention is coordinated across hemispheres. Our results are consistent with a unified attentional mechanism that can modulate the responses of arbitrary subgroups of neurons. PMID:21689604

  19. Can thermal perception in a building be predicted by the perceived spatial openness of a building in a hot and humid climate?

    NARCIS (Netherlands)

    Du, X.; Bokel, R.M.J.; van den Dobbelsteen, A.A.J.F.; Brotas, Luisa; Roaf, Susan; Nicol, Fergus

    2017-01-01

    The authors wanted to prove that there is a large correlation between the concepts spatial openness and comfort (visual, wind speed and thermal) perception in people’s minds in a hot and humid climate in summer in order to be able to use spatial configuration parameters such as openness,

  20. Speech perception as an active cognitive process

    Directory of Open Access Journals (Sweden)

    Shannon eHeald

    2014-03-01

    Full Text Available One view of speech perception is that acoustic signals are transformed into representations for pattern matching to determine linguistic structure. This process can be taken as a statistical pattern-matching problem, assuming realtively stable linguistic categories are characterized by neural representations related to auditory properties of speech that can be compared to speech input. This kind of pattern matching can be termed a passive process which implies rigidity of processingd with few demands on cognitive processing. An alternative view is that speech recognition, even in early stages, is an active process in which speech analysis is attentionally guided. Note that this does not mean consciously guided but that information-contingent changes in early auditory encoding can occur as a function of context and experience. Active processing assumes that attention, plasticity, and listening goals are important in considering how listeners cope with adverse circumstances that impair hearing by masking noise in the environment or hearing loss. Although theories of speech perception have begun to incorporate some active processing, they seldom treat early speech encoding as plastic and attentionally guided. Recent research has suggested that speech perception is the product of both feedforward and feedback interactions between a number of brain regions that include descending projections perhaps as far downstream as the cochlea. It is important to understand how the ambiguity of the speech signal and constraints of context dynamically determine cognitive resources recruited during perception including focused attention, learning, and working memory. Theories of speech perception need to go beyond the current corticocentric approach in order to account for the intrinsic dynamics of the auditory encoding of speech. In doing so, this may provide new insights into ways in which hearing disorders and loss may be treated either through augementation or

  1. Exploration, anxiety, and spatial memory in transgenic anophthalmic mice.

    Science.gov (United States)

    Buhot, M C; Dubayle, D; Malleret, G; Javerzat, S; Segu, L

    2001-04-01

    Contradictory results are found in the literature concerning the role of vision in the perception of space or in spatial navigation, in part because of the lack of murine models of total blindness used so far. The authors evaluated the spatial abilities of anophthalmic transgenic mice. These mice did not differ qualitatively from their wild-type littermates in general locomotor activity, spontaneous alternation, object exploration, or anxiety, but their level of exploratory activity was generally lower. In the spatial version of the water maze, they displayed persistent thigmotaxic behavior and showed severe spatial learning impairments. However, their performances improved with training, suggesting that they may have acquired a rough representation of the platform position. These results suggest that modalities other than vision enable some degree of spatial processing in proximal and structured spaces but that vision is critical for accurate spatial navigation.

  2. SoftAR: visually manipulating haptic softness perception in spatial augmented reality.

    Science.gov (United States)

    Punpongsanon, Parinya; Iwai, Daisuke; Sato, Kosuke

    2015-11-01

    We present SoftAR, a novel spatial augmented reality (AR) technique based on a pseudo-haptics mechanism that visually manipulates the sense of softness perceived by a user pushing a soft physical object. Considering the limitations of projection-based approaches that change only the surface appearance of a physical object, we propose two projection visual effects, i.e., surface deformation effect (SDE) and body appearance effect (BAE), on the basis of the observations of humans pushing physical objects. The SDE visualizes a two-dimensional deformation of the object surface with a controlled softness parameter, and BAE changes the color of the pushing hand. Through psychophysical experiments, we confirm that the SDE can manipulate softness perception such that the participant perceives significantly greater softness than the actual softness. Furthermore, fBAE, in which BAE is applied only for the finger area, significantly enhances manipulation of the perception of softness. We create a computational model that estimates perceived softness when SDE+fBAE is applied. We construct a prototype SoftAR system in which two application frameworks are implemented. The softness adjustment allows a user to adjust the softness parameter of a physical object, and the softness transfer allows the user to replace the softness with that of another object.

  3. Depth Perception in Cave and Panorama

    DEFF Research Database (Denmark)

    Mullins, Michael; Strojan, Tadeja Zupancic

    2004-01-01

    This study compares aspects of spatial perception in a physical environment and its virtual representations in a CAVE and Panorama, derived from recent research. To measure accuracy of spatial perception, participants in an experiment were asked to look at identical objects in the three environme......, learning and training in virtual environments; in architectural education; and participatory design processes, in which the dialogue between real and imagined space may take place in virtual . reality environments...... environments and then locate them and identify their shape on scaled drawings.  Results are presented together with statistical analysis. In a discussion of the results, the paper addresses the two hypothetical assertions ? that depth perception in physical reality and its virtual representations in CAVE......This study compares aspects of spatial perception in a physical environment and its virtual representations in a CAVE and Panorama, derived from recent research. To measure accuracy of spatial perception, participants in an experiment were asked to look at identical objects in the three...

  4. Exploring Uncertainty Perception as a Driver of Design Activity

    DEFF Research Database (Denmark)

    Cash, Philip; Kreye, Melanie

    2018-01-01

    , and representation action. We bring together prior works on uncertainty perception in the design and management literatures to derive three contributions. First, we describe how uncertainty perception is associated with activity progression, linking all three core actions. Second, we identify characteristic patterns...

  5. Spatial distribution of enzyme activities in the rhizosphere

    Science.gov (United States)

    Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2015-04-01

    The rhizosphere, the tiny zone of soil surrounding roots, certainly represents one of the most dynamic habitat and interfaces on Earth. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. That is why there is an urgent need in spatially explicit methods for the determination of the rhizosphere extension and enzyme distribution. Recently, zymography as a new technique based on diffusion of enzymes through the 1 mm gel plate for analysis has been introduced (Spohn & Kuzyakov, 2013). We developed the zymography technique to visualize the enzyme activities with a higher spatial resolution. For the first time, we aimed at quantitative imaging of enzyme activities as a function of distance from the root tip and the root surface in the soil. We visualized the two dimensional distribution of the activity of three enzymes: β-glucosidase, phosphatase and leucine amino peptidase in the rhizosphere of maize using fluorogenically labelled substrates. Spatial-resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography visualized heterogeneity of enzyme activities along the roots. The activity of all enzymes was the highest at the apical parts of individual roots. Across the roots, the enzyme activities were higher at immediate vicinity of the roots (1.5 mm) and gradually decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify spatial distribution of enzyme activities in the rhizosphere hotspots. References Spohn, M., Kuzyakov, Y., 2013. Phosphorus mineralization can be driven by microbial need for carbon. Soil Biology & Biochemistry 61: 69-75

  6. Perceptual spatial differentiation of Ljubljana

    Directory of Open Access Journals (Sweden)

    Marko Krevs

    2004-12-01

    Full Text Available Geographical studies of human perception of places at local scale are usually aimed at bet-ter understanding of human spatial perception and knowledge about the places, and of using this knowledge in spatial decision-making or spatial behaviour. Our focus on the first part of these general research aims is presented based on a case study, revealing how residents of the Municipality of Ljubljana perceive and value neighbourhoods of “their” municipality at the beginning of the century1.

  7. Reward associations magnify memory-based biases on perception.

    Science.gov (United States)

    Doallo, Sonia; Patai, Eva Zita; Nobre, Anna Christina

    2013-02-01

    Long-term spatial contextual memories are a rich source of predictions about the likely locations of relevant objects in the environment and should enable tuning of neural processing of unfolding events to optimize perception and action. Of particular importance is whether and how the reward outcome of past events can impact perception. We combined behavioral measures with recordings of brain activity with high temporal resolution to test whether the previous reward outcome associated with a memory could modulate the impact of memory-based biases on perception, and if so, the level(s) at which visual neural processing is biased by reward-associated memory-guided attention. Data showed that past rewards potentiate the effects of spatial memories upon the discrimination of target objects embedded within complex scenes starting from early perceptual stages. We show that a single reward outcome of learning impacts on how we perceive events in our complex environments.

  8. The rod orientation test in patients with right-hemisphere infarction : a clinical study of spatial perception in 154 subjects

    NARCIS (Netherlands)

    J.D. Meerwaldt (Johannes David (Jan))

    1982-01-01

    textabstractThis thesis describes a clinical study of disturbances of spatial perception. Chapter I gives a short review of hemispheric asymmetry. For a long time the right hemisphere was regarded as the minor hemisphere, of which substantial regions were thought to have no specific function.

  9. The Relation between Childhood Spatial Activities and Spatial Abilities in Adulthood

    Science.gov (United States)

    Doyle, Randi A.; Voyer, Daniel; Cherney, Isabelle D.

    2012-01-01

    This study investigated the relation between childhood spatial activities and cognitive gender differences in adults through the validation of the Childhood Activities Questionnaire developed by Cherney and Voyer (2010). A sample of 403 (133 males, 270 females) undergraduates in Introductory Psychology courses at University of New Brunswick, NB,…

  10. West African spatial patterns of economic activities

    DEFF Research Database (Denmark)

    Walther, Olivier; Howard, Allen; Retaillé, Denis

    2015-01-01

    Over the last 30 years, two different bodies of literature developed by both US historians and francophone geographers have moved toward similar conclusions regarding West African economic spatial patterns. Despite their different backgrounds, both the ‘spatial factor’ approach promoted by histor......Over the last 30 years, two different bodies of literature developed by both US historians and francophone geographers have moved toward similar conclusions regarding West African economic spatial patterns. Despite their different backgrounds, both the ‘spatial factor’ approach promoted...... by historians and the ‘mobile space’ approach developed by geographers view exchange centres as nodes of transnational trade networks and places in production territories, and perceive spatial dynamics as highly dependent on shifts of trade flows and production activities. The objective of this article...

  11. Temporal ventriloquism along the path of apparent motion: speed perception under different spatial grouping principles.

    Science.gov (United States)

    Ogulmus, Cansu; Karacaoglu, Merve; Kafaligonul, Hulusi

    2018-03-01

    The coordination of intramodal perceptual grouping and crossmodal interactions plays a critical role in constructing coherent multisensory percepts. However, the basic principles underlying such coordinating mechanisms still remain unclear. By taking advantage of an illusion called temporal ventriloquism and its influences on perceived speed, we investigated how audiovisual interactions in time are modulated by the spatial grouping principles of vision. In our experiments, we manipulated the spatial grouping principles of proximity, uniform connectedness, and similarity/common fate in apparent motion displays. Observers compared the speed of apparent motions across different sound timing conditions. Our results revealed that the effects of sound timing (i.e., temporal ventriloquism effects) on perceived speed also existed in visual displays containing more than one object and were modulated by different spatial grouping principles. In particular, uniform connectedness was found to modulate these audiovisual interactions in time. The effect of sound timing on perceived speed was smaller when horizontal connecting bars were introduced along the path of apparent motion. When the objects in each apparent motion frame were not connected or connected with vertical bars, the sound timing was more influential compared to the horizontal bar conditions. Overall, our findings here suggest that the effects of sound timing on perceived speed exist in different spatial configurations and can be modulated by certain intramodal spatial grouping principles such as uniform connectedness.

  12. EGFR Activation by Spatially Restricted Ligands

    National Research Council Canada - National Science Library

    Clouse, Katherine N; Goodrich, Jennifer S

    2006-01-01

    ...) functions in the localization and translational regulation of grk mRNA. The purpose of this project is to identify factors that function with Sqd to produce spatially-restricted Egfr activation...

  13. EGFR Activation by Spatially Restricted Ligands

    National Research Council Canada - National Science Library

    Goodrich, Jennifer S

    2005-01-01

    ...) functions in the localization and translational regulation of grk mRNA. The purpose of this project is to identify factors that function with Squid to produce spatially-restricted EGFR activation...

  14. Explaining sex differences in mental rotation: role of spatial activity experience.

    Science.gov (United States)

    Nazareth, Alina; Herrera, Asiel; Pruden, Shannon M

    2013-05-01

    Males consistently outperform females on mental rotation tasks, such as the Vandenberg and Kuse (1978) Perceptual and Motor Skills, 47(2), 599-604, mental rotation test (MRT; e.g. Voyer et al. 1995) in Psychological Bulletin, 117, 250-265. The present study investigates whether these sex differences in MRT scores can be explained in part by early spatial activity experience, particularly those spatial activities that have been sex-typed as masculine/male-oriented. Utilizing an online survey, 571 ethnically diverse adult university students completed a brief demographic survey, an 81-item spatial activity survey, and the MRT. Results suggest that the significant relation between sex of the participant and MRT score is partially mediated by the number of masculine spatial activities participants had engaged in as youth. Closing the gap between males and females in spatial ability, a skill linked to science, technology, engineering, and mathematics success, may be accomplished in part by encouraging female youth to engage in more particular kinds of spatial activities.

  15. Spatial frequency tuning during the conscious and non-conscious perception of emotional facial expressions—an intracranial ERP study

    Directory of Open Access Journals (Sweden)

    Verena eWillenbockel

    2012-07-01

    Full Text Available Previous studies have shown that complex visual stimuli, such as emotional facial expressions, can influence brain activity independently of the observers’ awareness. Little is known yet, however, about the informational correlates of consciousness—i.e., which low-level information correlates with brain activation during conscious vs. non-conscious perception. Here, we investigated this question in the spatial frequency (SF domain. We examined which SFs in disgusted and fearful facial expressions modulate activation in the insula and amygdala over time and as a function of awareness, using a combination of intracranial event-related potentials (ERPs, SF Bubbles (Willenbockel et al., 2010a, and Continuous Flash Suppression (CFS; Tsuchiya and Koch, 2005. Patients implanted with electrodes for epilepsy monitoring viewed face photographs (13° x 7° that were randomly SF filtered trial-by-trial. In the conscious condition, the faces were visible; in the non-conscious condition, they were rendered invisible using CFS. Data were analyzed by performing multiple linear regressions on the SF filters from each trial and the transformed ERP amplitudes across time. The resulting classification images suggest that many SFs are involved in the conscious and non-conscious perception of emotional expressions, with those between 6 and 10 cycles per face width being particularly important early on. The results also revealed qualitative differences between the awareness conditions for both regions. Non-conscious processing relied on low SFs more and was faster than conscious processing. Overall, our findings are consistent with the idea that different pathways are employed for the processing of emotional stimuli under different degrees of awareness. The present study represents a first step to mapping with a high temporal resolution how SF information flows through the emotion-processing network and to shedding light on the informational correlates of

  16. The Importance of Spatiotemporal Information in Biological Motion Perception: White Noise Presented with a Step-like Motion Activates the Biological Motion Area.

    Science.gov (United States)

    Callan, Akiko; Callan, Daniel; Ando, Hiroshi

    2017-02-01

    Humans can easily recognize the motion of living creatures using only a handful of point-lights that describe the motion of the main joints (biological motion perception). This special ability to perceive the motion of animate objects signifies the importance of the spatiotemporal information in perceiving biological motion. The posterior STS (pSTS) and posterior middle temporal gyrus (pMTG) region have been established by many functional neuroimaging studies as a locus for biological motion perception. Because listening to a walking human also activates the pSTS/pMTG region, the region has been proposed to be supramodal in nature. In this study, we investigated whether the spatiotemporal information from simple auditory stimuli is sufficient to activate this biological motion area. We compared spatially moving white noise, having a running-like tempo that was consistent with biological motion, with stationary white noise. The moving-minus-stationary contrast showed significant differences in activation of the pSTS/pMTG region. Our results suggest that the spatiotemporal information of the auditory stimuli is sufficient to activate the biological motion area.

  17. Staff members' perceptions of an animal-assisted activity.

    Science.gov (United States)

    Bibbo, Jessica

    2013-07-01

    To examine the perceptions of staff members toward the implementation of an animal-assisted activity (AAA) in an outpatient regional cancer center. Quasi-experimental, post-test design. An adult outpatient regional cancer center in northern California. 34 facility staff members. Self-report questionnaire following four weeks of AAA visitation. Visits took place three times a week for a total of 12 visits. Perceptions of the AAA. Previous perceptions toward AAA influenced the perceptions of the visitation's efficacy. Direct and indirect interaction with the visiting AAA teams was positively associated with perceptions of the AAA. A disagreement occurred that the AAA had caused extra stress or work for staff. Enjoyment of interacting with the dog handler was not significantly different from interacting with the dog; however, it was more positively correlated to acceptance of the AAA. The study provided evidence that the AAA was generally accepted by staff members. Individual staff members' perceptions of dogs and AAAs can influence their receptivity to AAA interventions. Interaction with AAA teams should be voluntary and available for patients and staff members. AAA may be introduced into facilities without creating the perception of extra stress or work for staff members. Providing staff the opportunity to interact with visiting AAA teams may be beneficial for the success of such programs. The human handler in AAA teams may play a vital role in the staff acceptance of such programs.

  18. Adolescents' Perceptions of a Gardening Activity at a Juvenile Justice Center.

    Science.gov (United States)

    Hardin-Fanning, Frances; Adegboyega, Adebola O; Rayens, Mary Kay

    2018-06-01

    The purpose of this study was to elicit participants' ( N = 16) perceptions of a gardening activity at a juvenile justice center and to determine whether past exposure to gardening and farmers markets was associated with their perceptions of the gardening experience. This cross-sectional, exploratory program evaluation was conducted in partnership with the Kentucky Department of Juvenile Justice. Adolescents completing the Cadet Leadership and Education Program participated in gardening in order to provide produce to a local farmers' market. After the growing season, participants were asked to complete a nine-item questionnaire about the gardening activity during one of their usual classes at the facility. The questionnaire assessed perception of the experience and past exposure to gardening and farmers' markets. Participants reported favorably about their participation in the activity, knowledge gained from the activity, and their intent to garden in the future. Those who had previously gardened had more favorable perception of gardening than those who had never gardened. Gardening is an inexpensive means of teaching teamwork and delayed gratification and providing a sense of empowerment and may benefit at-risk adolescents during incarceration.

  19. Neural Activity Patterns in the Human Brain Reflect Tactile Stickiness Perception

    Science.gov (United States)

    Kim, Junsuk; Yeon, Jiwon; Ryu, Jaekyun; Park, Jang-Yeon; Chung, Soon-Cheol; Kim, Sung-Phil

    2017-01-01

    Our previous human fMRI study found brain activations correlated with tactile stickiness perception using the uni-variate general linear model (GLM) (Yeon et al., 2017). Here, we conducted an in-depth investigation on neural correlates of sticky sensations by employing a multivoxel pattern analysis (MVPA) on the same dataset. In particular, we statistically compared multi-variate neural activities in response to the three groups of sticky stimuli: A supra-threshold group including a set of sticky stimuli that evoked vivid sticky perception; an infra-threshold group including another set of sticky stimuli that barely evoked sticky perception; and a sham group including acrylic stimuli with no physically sticky property. Searchlight MVPAs were performed to search for local activity patterns carrying neural information of stickiness perception. Similar to the uni-variate GLM results, significant multi-variate neural activity patterns were identified in postcentral gyrus, subcortical (basal ganglia and thalamus), and insula areas (insula and adjacent areas). Moreover, MVPAs revealed that activity patterns in posterior parietal cortex discriminated the perceptual intensities of stickiness, which was not present in the uni-variate analysis. Next, we applied a principal component analysis (PCA) to the voxel response patterns within identified clusters so as to find low-dimensional neural representations of stickiness intensities. Follow-up clustering analyses clearly showed separate neural grouping configurations between the Supra- and Infra-threshold groups. Interestingly, this neural categorization was in line with the perceptual grouping pattern obtained from the psychophysical data. Our findings thus suggest that different stickiness intensities would elicit distinct neural activity patterns in the human brain and may provide a neural basis for the perception and categorization of tactile stickiness. PMID:28936171

  20. Perceptions of STEM-based outreach activities in secondary education

    NARCIS (Netherlands)

    Vennix, J.; den Brok, P.J.; Taconis, R.

    2017-01-01

    We investigated and compared the learning environment perceptions of students, teachers and guides who participated in Science, Technology, Engineering and Mathematics (STEM)-based outreach activities in secondary education. In outreach activities, schools and teachers work together with companies

  1. Teachers' Perceptions and Practices of Active Learning in ...

    African Journals Online (AJOL)

    Teachers' Perceptions and Practices of Active Learning in Haramaya ... Science, Technology and Arts Research Journal ... traditional/lecture method, lack of students' interest, shortage of time, lack of instructional material and large class size.

  2. High and low spatial frequencies in website evaluations.

    Science.gov (United States)

    Thielsch, Meinald T; Hirschfeld, Gerrit

    2010-08-01

    Which features of websites are important for users' perceptions regarding aesthetics or usability? This study investigates how evaluations of aesthetic appeal and usability depend on high vs. low spatial frequencies. High spatial frequencies convey information on fine details, whereas low spatial frequencies convey information about the global layout. Participants rated aesthetic appeal and usability of 50 website screenshots from different domains. Screenshots were presented unfiltered, low-pass filtered with blurred targets or high-pass filtered with high-pass filtered targets. The main result is that low spatial frequencies can be seen to have a unique contribution in perceived website aesthetics, thus confirming a central prediction from processing fluency theory. There was no connection between low spatial frequencies and usability evaluations, whereas strong correlations were found between ratings of high-pass filtered websites and those of unfiltered websites in aesthetics and usability. This study thus offers a new perspective on the biological basis of users' website perceptions. This research links ergonomics to neurocognitive models of visual processing. This paper investigates how high and low spatial frequencies, which are neurologically processed in different visual pathways, independently contribute to users' perceptions of websites. This is very relevant for theories of website perceptions and for practitioners of web design.

  3. Direct electrical stimulation of human cortex evokes high gamma activity that predicts conscious somatosensory perception

    Science.gov (United States)

    Muller, Leah; Rolston, John D.; Fox, Neal P.; Knowlton, Robert; Rao, Vikram R.; Chang, Edward F.

    2018-04-01

    Objective. Direct electrical stimulation (DES) is a clinical gold standard for human brain mapping and readily evokes conscious percepts, yet the neurophysiological changes underlying these percepts are not well understood. Approach. To determine the neural correlates of DES, we stimulated the somatosensory cortex of ten human participants at frequency-amplitude combinations that both elicited and failed to elicit conscious percepts, meanwhile recording neural activity directly surrounding the stimulation site. We then compared the neural activity of perceived trials to that of non-perceived trials. Main results. We found that stimulation evokes distributed high gamma activity, which correlates with conscious perception better than stimulation parameters themselves. Significance. Our findings suggest that high gamma activity is a reliable biomarker for perception evoked by both natural and electrical stimuli.

  4. Parents' perceptions of skin cancer threat and children's physical activity.

    Science.gov (United States)

    Tran, Alexander D; Aalborg, Jenny; Asdigian, Nancy L; Morelli, Joseph G; Mokrohisky, Stefan T; Dellavalle, Robert P; Berwick, Marianne; Box, Neil F; Crane, Lori A

    2012-01-01

    Sun exposure is a major risk factor for skin cancer, but without physical activity, children are at risk of childhood obesity. The objective of this study was to explore relationships between parental perceptions of skin cancer threat, sun protection behaviors, physical activity, and body mass index (BMI) in children. This is a cross-sectional analysis nested within the Colorado Kids Sun Care Program sun safety intervention trial. In summer 2007, parent telephone interviews provided data on demographics, perceptions of skin cancer threat, sun protection behaviors, and physical activity. Physical examinations provided data on phenotype, freckling, and BMI. Data from 999 Colorado children born in 1998 were included in analysis. We used analysis of variance, Spearman's rho (ρ) correlation, and multivariable linear regression analysis to evaluate relationships with total amount of outdoor physical activity. After controlling for sex, race/ethnicity, skin color, and sun protection, regression analysis showed that each unit increase in perceived severity of nonmelanoma skin cancer was associated with a 30% increase in hours of outdoor physical activity (P = .005). Hours of outdoor physical activity were not related to perceived severity of melanoma or perceived susceptibility to skin cancer. BMI-for-age was not significantly correlated with perceptions of skin cancer threat, use of sun protection, or level of physical activity. The promotion of sun safety is not likely to inhibit physical activity. Skin cancer prevention programs should continue to promote midday sun avoidance and sun protection during outdoor activities.

  5. Perceptions of Active Versus Passive Risks, and the Effect of Personal Responsibility.

    Science.gov (United States)

    Keinan, Ruty; Bereby-Meyer, Yoella

    2017-07-01

    Not getting vaccinated or not backing up computer files are examples of passive risk taking: risk brought on or magnified by inaction. We suggest the difficulty in paying attention to absences, together with the reduced agency and responsibility that is associated with passive choices, leads to the perception of passive risks as being less risky than equivalent active risks. Using scenarios in which risk was taken either actively or passively, we demonstrate that passive risks are judged as less risky than equivalent active risks. We find the perception of personal responsibility mediates the differences between the perception of passive and active risks. The current research offers an additional explanation for omission or default biases: The passive nature of these choices causes them to appear less risky than they really are.

  6. Directional loudness perception

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka

    developed. The research and modeling of loudness have mainly been concerned with the temporal and spectral aspects of sounds, while the spatial aspects have mostly been overlooked. This PhD thesis investigates the spatial aspects of loudness perception, namely, how does the direction from which a sound...

  7. Alpha-Band Activity Reveals Spontaneous Representations of Spatial Position in Visual Working Memory.

    Science.gov (United States)

    Foster, Joshua J; Bsales, Emma M; Jaffe, Russell J; Awh, Edward

    2017-10-23

    An emerging view suggests that spatial position is an integral component of working memory (WM), such that non-spatial features are bound to locations regardless of whether space is relevant [1, 2]. For instance, past work has shown that stimulus position is spontaneously remembered when non-spatial features are stored. Item recognition is enhanced when memoranda appear at the same location where they were encoded [3-5], and accessing non-spatial information elicits shifts of spatial attention to the original position of the stimulus [6, 7]. However, these findings do not establish that a persistent, active representation of stimulus position is maintained in WM because similar effects have also been documented following storage in long-term memory [8, 9]. Here we show that the spatial position of the memorandum is actively coded by persistent neural activity during a non-spatial WM task. We used a spatial encoding model in conjunction with electroencephalogram (EEG) measurements of oscillatory alpha-band (8-12 Hz) activity to track active representations of spatial position. The position of the stimulus varied trial to trial but was wholly irrelevant to the tasks. We nevertheless observed active neural representations of the original stimulus position that persisted throughout the retention interval. Further experiments established that these spatial representations are dependent on the volitional storage of non-spatial features rather than being a lingering effect of sensory energy or initial encoding demands. These findings provide strong evidence that online spatial representations are spontaneously maintained in WM-regardless of task relevance-during the storage of non-spatial features. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Working women's perceptions of participation in physical activity and ...

    African Journals Online (AJOL)

    Participation in physical activity helps one to address and reduce health risk behaviours thereby improving the quality of one's life. The current study explored the relationship between satisfaction with life and working women's perception of their participation in physical activity in the Gauteng Province, South Africa. Using a ...

  9. Virtual Reality Learning Activities for Multimedia Students to Enhance Spatial Ability

    Directory of Open Access Journals (Sweden)

    Rafael Molina-Carmona

    2018-04-01

    Full Text Available Virtual Reality is an incipient technology that is proving very useful for training different skills. Our hypothesis is that it is possible to design virtual reality learning activities that can help students to develop their spatial ability. To prove the hypothesis, we have conducted an experiment consisting of training the students using an on-purpose learning activity based on a virtual reality application and assessing the possible improvement of the students’ spatial ability through a widely accepted spatial visualization test. The learning activity consists of a virtual environment where some simple polyhedral shapes are shown and manipulated by moving, rotating and scaling them. The students participating in the experiment are divided into a control and an experimental group, carrying out the same learning activity with the only difference of the device used for the interaction: a traditional computer with screen, keyboard and mouse for the control group, and virtual reality goggles with a smartphone for the experimental group. To assess the experience, all the students have completed a spatial visualization test twice: just before performing the activities and four weeks later, once all the activities were performed. Specifically, we have used the well-known and widely used Purdue Spatial Visualization Test—Rotation (PSVT-R, designed to test rotational visualization ability. The results of the test show that there is an improvement in the test results for both groups, but the improvement is significantly higher in the case of the experimental group. The conclusion is that the virtual reality learning activities have shown to improve the spatial ability of the experimental group.

  10. Problem-Based Group Activities for Teaching Sensation and Perception

    Science.gov (United States)

    Kreiner, David S.

    2009-01-01

    This article describes 14 problem-based group activities for a sensation and perception course. The intent was to provide opportunities for students to practice applying their knowledge to real-world problems related to course content. Student ratings of how effectively the activities helped them learn were variable but relatively high. Students…

  11. Brain mechanisms for simple perception and bistable perception.

    Science.gov (United States)

    Wang, Megan; Arteaga, Daniel; He, Biyu J

    2013-08-27

    When faced with ambiguous sensory inputs, subjective perception alternates between the different interpretations in a stochastic manner. Such multistable perception phenomena have intrigued scientists and laymen alike for over a century. Despite rigorous investigations, the underlying mechanisms of multistable perception remain elusive. Recent studies using multivariate pattern analysis revealed that activity patterns in posterior visual areas correlate with fluctuating percepts. However, increasing evidence suggests that vision--and perception at large--is an active inferential process involving hierarchical brain systems. We applied searchlight multivariate pattern analysis to functional magnetic resonance imaging signals across the human brain to decode perceptual content during bistable perception and simple unambiguous perception. Although perceptually reflective activity patterns during simple perception localized predominantly to posterior visual regions, bistable perception involved additionally many higher-order frontoparietal and temporal regions. Moreover, compared with simple perception, both top-down and bottom-up influences were dramatically enhanced during bistable perception. We further studied the intermittent presentation of ambiguous images--a condition that is known to elicit perceptual memory. Compared with continuous presentation, intermittent presentation recruited even more higher-order regions and was accompanied by further strengthened top-down influences but relatively weakened bottom-up influences. Taken together, these results strongly support an active top-down inferential process in perception.

  12. Spatial consequences of bridging the saccadic gap

    DEFF Research Database (Denmark)

    Yarrow, Kielan; Whiteley, Louise Emma; Rothwell, John C

    2006-01-01

    with the post-saccadic image. We first demonstrate that this illusion holds for moving objects, implying that the perception of time, velocity, and distance traveled become discrepant. We then show that this discrepancy is partially resolved up to 500 ms after a saccade: the perceived offset position of a post......We report six experiments suggesting that conscious perception is actively redrafted to take account of events both before and after the event that is reported. When observers saccade to a stationary object they overestimate its duration, as if the brain were filling in the saccadic gap......-saccadic moving stimulus shows a greater forward mislocalization when pursued after a saccade than during pursuit alone. These data are consistent with the idea that the temporal bias is resolved by the subsequent spatial adjustment to provide a percept that is coherent in its gist but inconsistent in its detail....

  13. Why Change to Active Learning? Pre-Service and In-Service Science Teachers' Perceptions

    Science.gov (United States)

    O'Grady, Audrey; Simmie, Geraldine Mooney; Kennedy, Therese

    2014-01-01

    This article explores pre-service and in-service science teachers' perceptions on active learning, and examines the effectiveness of active learning by pre-service science teachers in the Irish second level classroom through a two-phase study. In the first phase, data on perceptions were gathered from final year pre-service teachers and in-service…

  14. Spatial heterogeneity analysis of brain activation in fMRI

    Directory of Open Access Journals (Sweden)

    Lalit Gupta

    2014-01-01

    Full Text Available In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD activation maps appear more (diffusively distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness, complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix, and gappiness between activated regions (lacunarity. To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70% and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients.

  15. PETE Students' Perceptions of a Healthy and Active Lifestyle

    Science.gov (United States)

    Wilkinson, Carol; Pennington, Todd; Barney, David; Lockhart, Barbara; Hager, Ron; Prusak, Keven

    2014-01-01

    Participants were male and female students (n = 12) in a physical education teacher education (PETE) program with a healthy and active lifestyle management (HALM) focus, at a university in the Intermountain West. The purpose of the study was to examine PETE students' perceptions of a healthy and active lifestyle (HAL). Following inductive content…

  16. Effects of spatial scale on the perception and assessment of risk of natural disturbance in forested ecosystems: examples from northeastern Oregon

    Science.gov (United States)

    R. James Barbour; Miles Hemstrom; Alan Ager; Jane L. Hayes

    2005-01-01

    The perception and measurement of the risk of natural disturbances often varies depending on the spatial and temporal scales over which information is collected or analyzed. This can lead to conflicting conclusions about severity of current or past disturbances or the risk of future ones. Failure to look across scales also complicates local implementation of policies...

  17. The Invisible Employee: University Housekeeping Employees' Perceptions of Physical Activity.

    Science.gov (United States)

    Das, Bhibha M; Sartore-Baldwin, Melanie; Mahar, Matthew T

    2016-09-01

    A significant literature links race and socioeconomic status with physical inactivity and negative health outcomes. The aim of this study was to explore physical activity (PA) perceptions of an underserved, lower socioeconomic minority sector of the workforce. Two focus groups were conducted to examine university housekeepers' perceptions of physical activity. Demographic and anthropometric data were also obtained. Participants (N = 12; 100% female, 100% African-American) overwhelmingly associated PA with traditional exercise (eg, going to a gym). The most important barrier to PA was the perception of being active on the job, thus not needing to do leisure time PA. The most important perceived benefit to PA was improvement of physical and mental health. Employees perceived that a university investment in employees' health might improve morale, especially within low-pay employee sectors where low levels of job satisfaction may be present. Although perceived benefits to PA in this population are consistent with other employee sectors, perceived barriers to PA may be unique to this sector of the workforce. PA promotion programs should focus on providing resources as well as guidelines that demonstrate the need for PA outside of the workplace setting. Such programs may improve employee health, morale, and productivity.

  18. Developmental changes in ERP responses to spatial frequencies

    NARCIS (Netherlands)

    van den Boomen, Carlijn; Jonkman, Lisa M; Jaspers-Vlamings, Petra H J M; Cousijn, Janna; Kemner, Chantal

    2015-01-01

    Social interaction starts with perception of other persons. One of the first steps in perception is processing of basic information such as spatial frequencies (SF), which represent details and global information. However, although behavioural perception of SF is well investigated, the developmental

  19. Attention to Hierarchical Level Influences Attentional Selection of Spatial Scale

    Science.gov (United States)

    Flevaris, Anastasia V.; Bentin, Shlomo; Robertson, Lynn C.

    2011-01-01

    Ample evidence suggests that global perception may involve low spatial frequency (LSF) processing and that local perception may involve high spatial frequency (HSF) processing (Shulman, Sullivan, Gish, & Sakoda, 1986; Shulman & Wilson, 1987; Robertson, 1996). It is debated whether SF selection is a low-level mechanism associating global…

  20. Parental Perceptions of Physical Activity Benefits for Youth with Developmental Disabilities

    Science.gov (United States)

    Pitchford, E. Andrew; Siebert, Erin; Hamm, Jessica; Yun, Joonkoo

    2016-01-01

    Physical activity promotion is of need for youth with developmental disabilities. Parental perceptions of physical activity benefits may influence youth behaviors. This study investigated the relationship between parental beliefs on the importance of physical activity and physical activity levels among youth with disabilities. Parents and…

  1. Spatial diversity of spontaneous activity in the cortex

    Directory of Open Access Journals (Sweden)

    Andrew Yong-Yi Tan

    2015-09-01

    Full Text Available The neocortex is a layered sheet across which a basic organization is thought to widely apply. The variety of spontaneous activity patterns is similar throughout the cortex, consistent with the notion of a basic cortical organization. However, the basic organization is only an outline which needs adjustments and additions to account for the structural and functional diversity across cortical layers and areas. Such diversity suggests that spontaneous activity is spatially diverse in any particular behavioral state. Accordingly, this review summarizes the laminar and areal diversity in cortical activity during fixation and slow oscillations, and the effects of attention, anesthesia and plasticity on the cortical distribution of spontaneous activity. Among questions that remain open, characterizing the spatial diversity in spontaneous membrane potential may help elucidate how differences in circuitry among cortical regions supports their varied functions. More work is also needed to understand whether cortical spontaneous activity not only reflects cortical circuitry, but also contributes to determining the outcome of plasticity, so that it is itself a factor shaping the functional diversity of the cortex.

  2. Enrolment Purposes, Instructional Activities, and Perceptions of Attitudinal Learning in a Human Trafficking MOOC

    Science.gov (United States)

    Watson, Sunnie Lee; Kim, Woori

    2016-01-01

    This study examines learner enrolment purposes, perceptions on instructional activities and their relationship to learning gains in a Massive Open Online Course (MOOC) for attitudinal change regarding human trafficking. Using an author-developed survey, learners reported their perceptions on instructional activities and learning gains within the…

  3. Networking activities and perceptions of HIV risk among male migrant market vendors in China.

    Science.gov (United States)

    Wang, Wenqing; Muessig, Kathryn E; Li, Mingqiang; Zhang, Ying-Xia; Zhang, Yingxia

    2014-02-01

    HIV research among internal migrants in China has not fully explored the contexts and perceptions of "risk". In 2011, urban markets in Liuzhou, China were mapped, and sixty male vendors, age 22-56, were selected for in-depth interviews on migration, social and family life, and perceptions and practices of sexual risk behavior. Participants were evenly divided among higher income shop and small stall vendors. All men were sexually active. Only the shop vendors reported non-marital sexual partners, including concurrent partners (n = 15), commercial partners (n = 10), and other sexual relationships (n = 11). Shop vendors engaged in networking activities that facilitated commercial and non-commercial high-risk sex. Perceptions of HIV risk from commercial sex led some men to doubt the protective ability of condoms and rely on local (unproven) self-protection techniques. Networking activities played a role in high-risk sex and shaping migrants' risk perceptions and health practices. The networks created through these processes could also be used to facilitate health promotion activities.

  4. The Effect of Employees’ Perceptions of CSR Activities on Employee Deviance: The Mediating Role of Anomie

    Directory of Open Access Journals (Sweden)

    Yun Hyeok Choi

    2018-02-01

    Full Text Available This study hypothesizes that employees’ positive perceptions of corporate social responsibility (CSR activities at the individual level have a negative effect on employee deviance—a negative job-related behavior—and that anomie plays a mediating role in this relationship. In order to verify the relationship, this study conducts an empirical analysis with a questionnaire survey on employees of firms that implement CSR activities at the company level. Based on Social identity theory, this study examines the causal relationship between the employees’ perceptions of CSR activities and their deviance, and mechanisms by which anomie decreases in the process. The findings are as follows. First, employees’ perceptions of CSR activities had a negative effect on employee deviance. Second, employees’ perceptions of CSR activities had a negative effect on anomie. Third, anomie had a positive effect on employee deviance. Fourth, anomie fully mediated the relationship between employees’ perceptions of CSR activities and employee deviance. This study is the first to document this relationship, which has great practical and academic significance, as it indicates the importance for companies to consider employees’ perceptions of CSR activities. In addition, the study identifies the mediating role of anomie as mentioned above. The results suggest that methodological considerations of CSR awareness enhancement at the company level be discussed more in depth, helping top management and middle managers understand that enhancing employees’ positive perceptions of CSR activities should be the first priority for reducing collective normlessness under the pressure of goal attainment and resolving ethical conflicts among employees.

  5. The perceptual basis of spatial sound perception

    NARCIS (Netherlands)

    Kohlrausch, A.G.

    2003-01-01

    Our ability to derive spatial impressions from a sound field is based on the facts that we have two sensors which are spatially separated by typically 18 cm and that the space in between these sensors is filled by acoustically nontransparant material. The first fact leads to a time difference at the

  6. Meaningful spatial and temporal sequences of activities in dwelling

    NARCIS (Netherlands)

    Hematalikeikha, M.A.; Coolen, H.C.C.H.; Pourdeihimi, S.

    2014-01-01

    Human activities based on human needs are affected by affordances and meanings that occur in the dwelling. Activities over time and space have meaningful sequences. The meaningfulness of activities in the cultural framework is conditioned by its special temporality and spatiality. Also, temporal or

  7. Spatial and Social Aspects of Crowding Perception

    Science.gov (United States)

    Baum, Andrew; Davis, Glenn E.

    1976-01-01

    This paper discusses mediation of the crowding experience in architectural interiors by three environmental variables: setting orientation, room color, and visual complexity of the interior. Data indicated interior design does influence space perception and crowding thresholds. (RH)

  8. Longitudinal changes in physical self-perceptions and associations with physical activity during adolescence.

    Science.gov (United States)

    Inchley, Jo; Kirby, Jo; Currie, Candace

    2011-05-01

    The purpose of this study was to examine adolescents' physical self-perceptions and their associations with physical activity using a longitudinal perspective. Utilizing data from the Physical Activity in Scottish Schoolchildren (PASS) study, changes in exercise self-efficacy, perceived competence, global self-esteem and physical self-worth were assessed among a sample of 641 Scottish adolescents from age 11-15 years. Girls reported lower levels of perceived competence, self-esteem and physical self-worth than boys at each age. Furthermore, girls' physical self-perceptions decreased markedly over time. Among boys, only perceived competence decreased, while global self-esteem increased. Baseline physical activity was a significant predictor of later activity levels for both genders. Findings demonstrate the importance of physical self-perceptions in relation to physical activity behavior among adolescents. Among older boys, high perceived competence increased the odds of being active by 3.8 times. Among older girls, high exercise self-efficacy increased the odds of being active by 5.2 times. There is a need for early interventions which promote increased physical literacy and confidence, particularly among girls.

  9. A comparison of pharmacy students' and active older adults' perceptions regarding geriatric quality of life.

    Science.gov (United States)

    Gilligan, Adrienne M; Loui, James Aaron; Mezdo, Ashorena; Patel, Nikita; Lee, Jeannie K

    2014-02-12

    To measure perceptions of quality of life (QOL) in an active geriatric population and compare their responses with pharmacy students' perceptions of older adult QOL. Pharmacy students and active older adults completed the modified and standard version of a validated health survey instrument, respectively, and their responses were compared. Eighty-six students and 20 active older adults participated. Student perceptions of geriatric QOL were significantly lower in all domains except health change compared to older adult perceptions (p<0.001 for all domains). Interest in a geriatric pharmacy career (p=0.04) and previously having taken the Perspectives in Geriatrics course and laboratory (p=0.05 and 0.02, respectively) were significantly associated with higher student scores on the physical component portion of the survey. Stronger emphasis on geriatric QOL within pharmacy curricula may improve pharmacy students' perceptions regarding outcomes related to healthy older adults.

  10. Evaluating Risk Perception based on Gender Differences for Mountaineering Activity

    Science.gov (United States)

    Susanto, Novie; Susatyo, Nugroho W. P.; Rizkiyah, Ega

    2018-02-01

    In average 26 death events in mountaineering per year for the time span from 2003 to 2012 is reported. The number of women dying during the mountaineering is significantly smaller than males (3.5 deaths male for one female death). This study aims to analyze the differences of risk perception based on gender and provide recommendations as education basic to prevent accidents in mountaineering. This study utilizes the Kruskal-Wallis test and the Delphi Method. A total of 200 mountaineer respondents (100 males and 100 females) participated in this study. The independent variable in this study was gender. The dependent variable was risk perception including perception toward the serious accident, perception toward the probability of accident event as well as anxiety level and perception of efficacy and self-efficacy. The study result showed that the risk perception of women is higher than men with significant difference (p-value = 0.019). The recommendations from Delphi method result are by developing a positive mental attitude, showing about the risks that exist in nature, implementing Cognitive Behaviour Therapy (CBT) to raise awareness of the safety of ownself, following the climbing or mountaineer school, and using instructors to give lessons about safety in outdoor activities.

  11. Evaluating Risk Perception based on Gender Differences for Mountaineering Activity

    Directory of Open Access Journals (Sweden)

    Susanto Novie

    2018-01-01

    Full Text Available In average 26 death events in mountaineering per year for the time span from 2003 to 2012 is reported. The number of women dying during the mountaineering is significantly smaller than males (3.5 deaths male for one female death. This study aims to analyze the differences of risk perception based on gender and provide recommendations as education basic to prevent accidents in mountaineering. This study utilizes the Kruskal-Wallis test and the Delphi Method. A total of 200 mountaineer respondents (100 males and 100 females participated in this study. The independent variable in this study was gender. The dependent variable was risk perception including perception toward the serious accident, perception toward the probability of accident event as well as anxiety level and perception of efficacy and self-efficacy. The study result showed that the risk perception of women is higher than men with significant difference (p-value = 0.019. The recommendations from Delphi method result are by developing a positive mental attitude, showing about the risks that exist in nature, implementing Cognitive Behaviour Therapy (CBT to raise awareness of the safety of ownself, following the climbing or mountaineer school, and using instructors to give lessons about safety in outdoor activities.

  12. Pubertal development, physical self-perception, and motivation toward physical activity in girls.

    Science.gov (United States)

    Labbrozzi, Dina; Robazza, Claudio; Bertollo, Maurizio; Bucci, Ines; Bortoli, Laura

    2013-08-01

    We examined the differences in physical self-perception and motivation toward physical activity in early- and mid-adolescent girls. Body Mass Index (BMI) and pubertal status, assessed by means of the Tanner scale, were collected in 11-year-old (n=74) and 13-year-old girls (n=60). The assessment included six scales from the Physical Self-Description Questionnaire, the Physical Activity Enjoyment Scale, and the Situational Intrinsic Motivation Scale. Age differences emerged, with older girls showing a poorer physical perception and lower scores in intrinsic motivation and enjoyment of physical activity. In the subsample of 11-year-olds, findings showed that more developed girls reported a poorer physical perception on the scales of body fat, global physical self-concept, and appearance, and a lower score in the PACES positive scale. Results underscore the need to promote interventions aimed at encouraging active lifestyles among children and adolescent girls, in order to prevent overweight prior to pubertal onset. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  13. The relationship between subjective perception and the psychological effects of patients in spatial isolation.

    Science.gov (United States)

    Ibert, Fabienne; Eckstein, Monika; Günther, Frank; Mutters, Nico T

    2017-01-01

    Background: Spatial isolation is a common infection control measure, but negative psychological effects are often neglected. We investigated which factors influence the perception of single room isolated patients. Methods: In the present correlative cross-sectional study, 32 isolated patients have been interviewed within three departments of the Heidelberg University Hospital, one of Germany's largest hospitals. The following questionnaires were used: 10-Item Big Five Inventory (BFI-10), Positive and Negative Affect Schedule (PANAS), Hospital Anxiety and Depression Scale (HADS) and a self-developed questionnaire to evaluate the individual experience of isolation. Data were analysed using correlation and regression analysis. Results: A significant positive correlation was found between the isolation period and anxiety (r=.42, pSurfing the internet had a positive relationship with thinking about beautiful things (r=.41, pwell-being of the patient.

  14. Comparing spatial tuning curves, spectral ripple resolution, and speech perception in cochlear implant users.

    Science.gov (United States)

    Anderson, Elizabeth S; Nelson, David A; Kreft, Heather; Nelson, Peggy B; Oxenham, Andrew J

    2011-07-01

    Spectral ripple discrimination thresholds were measured in 15 cochlear-implant users with broadband (350-5600 Hz) and octave-band noise stimuli. The results were compared with spatial tuning curve (STC) bandwidths previously obtained from the same subjects. Spatial tuning curve bandwidths did not correlate significantly with broadband spectral ripple discrimination thresholds but did correlate significantly with ripple discrimination thresholds when the rippled noise was confined to an octave-wide passband, centered on the STC's probe electrode frequency allocation. Ripple discrimination thresholds were also measured for octave-band stimuli in four contiguous octaves, with center frequencies from 500 Hz to 4000 Hz. Substantial variations in thresholds with center frequency were found in individuals, but no general trends of increasing or decreasing resolution from apex to base were observed in the pooled data. Neither ripple nor STC measures correlated consistently with speech measures in noise and quiet in the sample of subjects in this study. Overall, the results suggest that spectral ripple discrimination measures provide a reasonable measure of spectral resolution that correlates well with more direct, but more time-consuming, measures of spectral resolution, but that such measures do not always provide a clear and robust predictor of performance in speech perception tasks. © 2011 Acoustical Society of America

  15. Spatial Frequency Discrimination : Effects of Age, Reward, and Practice

    OpenAIRE

    van den Boomen, Carlijn; Peters, Judith Carolien

    2017-01-01

    Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effec...

  16. Feeling form: the neural basis of haptic shape perception.

    Science.gov (United States)

    Yau, Jeffrey M; Kim, Sung Soo; Thakur, Pramodsingh H; Bensmaia, Sliman J

    2016-02-01

    The tactile perception of the shape of objects critically guides our ability to interact with them. In this review, we describe how shape information is processed as it ascends the somatosensory neuraxis of primates. At the somatosensory periphery, spatial form is represented in the spatial patterns of activation evoked across populations of mechanoreceptive afferents. In the cerebral cortex, neurons respond selectively to particular spatial features, like orientation and curvature. While feature selectivity of neurons in the earlier processing stages can be understood in terms of linear receptive field models, higher order somatosensory neurons exhibit nonlinear response properties that result in tuning for more complex geometrical features. In fact, tactile shape processing bears remarkable analogies to its visual counterpart and the two may rely on shared neural circuitry. Furthermore, one of the unique aspects of primate somatosensation is that it contains a deformable sensory sheet. Because the relative positions of cutaneous mechanoreceptors depend on the conformation of the hand, the haptic perception of three-dimensional objects requires the integration of cutaneous and proprioceptive signals, an integration that is observed throughout somatosensory cortex. Copyright © 2016 the American Physiological Society.

  17. A Spatial Analysis of Tourism Activity in Romania

    Directory of Open Access Journals (Sweden)

    Daniela Luminita Constantin

    2018-02-01

    Full Text Available Location is a key concept in tourism sector analysis, given the dependence of this activity on the natural, built, cultural and social characteristics of a certain territory. As a result, the tourist zoning is an important instrument for delimiting tourist areas in accordance with multiple criteria, so as to lay the foundations for finding the most suitable solutions of turning to good account the resources in this field. The modern approaches proposed in this paper use a series of analytical tools that combine GIS and spatial agglomeration analysis based techniques. They can be also employed in order to examine and explain the differences between tourist zones (and sub-zones in terms of economic and social results and thus to suggest realistic ways to improve the efficiency and effectiveness of tourist activities in various geographical areas. In the described context this paper proposes an interdisciplinary perspective (spatial statistics and Geographical Information Systems for analysing the tourism activity in Romania, mainly aiming to identify the agglomerations of companies acting in this industry and assess their performance and contribution to the economic development of the corresponding regions. It also intends to contribute to a better understanding of the way in which tourism related business activities develop, in order to enhance appropriate support networks. Territorial and spatial statistics, as well as GIS based analyses are applied, using data about all companies acting in tourism industry in Romania provided by the National Authority for Tourism as well as data from the Environmental Systems Research Institute (ESRI.

  18. The Influence of Eye Closure on Somatosensory Discrimination: A Trade-off Between Simple Perception and Discrimination.

    Science.gov (United States)

    Götz, Theresa; Hanke, David; Huonker, Ralph; Weiss, Thomas; Klingner, Carsten; Brodoehl, Stefan; Baumbach, Philipp; Witte, Otto W

    2017-06-01

    We often close our eyes to improve perception. Recent results have shown a decrease of perception thresholds accompanied by an increase in somatosensory activity after eye closure. However, does somatosensory spatial discrimination also benefit from eye closure? We previously showed that spatial discrimination is accompanied by a reduction of somatosensory activity. Using magnetoencephalography, we analyzed the magnitude of primary somatosensory (somatosensory P50m) and primary auditory activity (auditory P50m) during a one-back discrimination task in 21 healthy volunteers. In complete darkness, participants were requested to pay attention to either the somatosensory or auditory stimulation and asked to open or close their eyes every 6.5 min. Somatosensory P50m was reduced during a task requiring the distinguishing of stimulus location changes at the distal phalanges of different fingers. The somatosensory P50m was further reduced and detection performance was higher during eyes open. A similar reduction was found for the auditory P50m during a task requiring the distinguishing of changing tones. The function of eye closure is more than controlling visual input. It might be advantageous for perception because it is an effective way to reduce interference from other modalities, but disadvantageous for spatial discrimination because it requires at least one top-down processing stage. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Spatial relationship between climatologies and changes in global vegetation activity.

    Science.gov (United States)

    de Jong, Rogier; Schaepman, Michael E; Furrer, Reinhard; de Bruin, Sytze; Verburg, Peter H

    2013-06-01

    Vegetation forms a main component of the terrestrial biosphere and plays a crucial role in land-cover and climate-related studies. Activity of vegetation systems is commonly quantified using remotely sensed vegetation indices (VI). Extensive reports on temporal trends over the past decades in time series of such indices can be found in literature. However, little remains known about the processes underlying these changes at large spatial scales. In this study, we aimed at quantifying the spatial relationship between changes in potential climatic growth constraints (i.e. temperature, precipitation and incident solar radiation) and changes in vegetation activity (1982-2008). We demonstrate an additive spatial model with 0.5° resolution, consisting of a regression component representing climate-associated effects and a spatially correlated field representing the combined influence of other factors, including land-use change. Little over 50% of the spatial variance could be attributed to changes in climatologies; conspicuously, many greening trends and browning hotspots in Argentina and Australia. The nonassociated model component may contain large-scale human interventions, feedback mechanisms or natural effects, which were not captured by the climatologies. Browning hotspots in this component were especially found in subequatorial Africa. On the scale of land-cover types, strongest relationships between climatologies and vegetation activity were found in forests, including indications for browning under warming conditions (analogous to the divergence issue discussed in dendroclimatology). © 2013 Blackwell Publishing Ltd.

  20. Spatial specificity of working memory representations in the early visual cortex.

    Science.gov (United States)

    Pratte, Michael S; Tong, Frank

    2014-03-19

    Recent fMRI decoding studies have demonstrated that early retinotopic visual areas exhibit similar patterns of activity during the perception of a stimulus and during the maintenance of that stimulus in working memory. These findings provide support for the sensory recruitment hypothesis that the mechanisms underlying perception serve as a foundation for visual working memory. However, a recent study by Ester, Serences, and Awh (2009) found that the orientation of a peripheral grating maintained in working memory could be classified from both the contralateral and ipsilateral regions of the primary visual cortex (V1), implying that, unlike perception, feature-specific information was maintained in a nonretinotopic manner. Here, we evaluated the hypothesis that early visual areas can maintain information in a spatially specific manner and will do so if the task encourages the binding of feature information to a specific location. To encourage reliance on spatially specific memory, our experiment required observers to retain the orientations of two laterally presented gratings. Multivariate pattern analysis revealed that the orientation of each remembered grating was classified more accurately based on activity patterns in the contralateral than in the ipsilateral regions of V1 and V2. In contrast, higher extrastriate areas exhibited similar levels of performance across the two hemispheres. A time-resolved analysis further indicated that the retinotopic specificity of the working memory representation in V1 and V2 was maintained throughout the retention interval. Our results suggest that early visual areas provide a cortical basis for actively maintaining information about the features and locations of stimuli in visual working memory.

  1. Self-perceptions and physical activity in children with and without motor problems

    NARCIS (Netherlands)

    Noordstar, J.J.

    2017-01-01

    Self-perceptions influence global self-esteem and intrinsic motivation for achievement behavior (e.g., physical activity). Physical activity is an important component of a healthy lifestyle. Participation in physical activity is preventive against obesity and positively influences mental health

  2. 77 FR 7244 - Agency Information Collection (Supplier Perception Survey) Activity Under OMB Review

    Science.gov (United States)

    2012-02-10

    ... Perception Survey) Activity Under OMB Review AGENCY: Office of Acquisition, Logistics and Construction... Veterans Affairs Supplier Perception Survey. OMB Control Number: 2900-2900-0751. Type of Review: Extension... and logistics operations across VA enterprise. An agency may not conduct or sponsor, and a person is...

  3. 75 FR 1119 - Agency Information Collection (Supplier Perception Survey) Activity Under OMB Review

    Science.gov (United States)

    2010-01-08

    ... (Supplier Perception Survey) Activity Under OMB Review AGENCY: Office of Acquisition, Logistics and...).'' SUPPLEMENTARY INFORMATION: Title: Department of Veterans Affairs Supplier Perception Survey. OMB Control Number..., and a person is not required to respond to a collection of information unless it displays a currently...

  4. Spatial Attention and Audiovisual Interactions in Apparent Motion

    Science.gov (United States)

    Sanabria, Daniel; Soto-Faraco, Salvador; Spence, Charles

    2007-01-01

    In this study, the authors combined the cross-modal dynamic capture task (involving the horizontal apparent movement of visual and auditory stimuli) with spatial cuing in the vertical dimension to investigate the role of spatial attention in cross-modal interactions during motion perception. Spatial attention was manipulated endogenously, either…

  5. Dissociable cerebellar activity during spatial navigation and visual memory in bilateral vestibular failure.

    Science.gov (United States)

    Jandl, N M; Sprenger, A; Wojak, J F; Göttlich, M; Münte, T F; Krämer, U M; Helmchen, C

    2015-10-01

    Spatial orientation and navigation depends on information from the vestibular system. Previous work suggested impaired spatial navigation in patients with bilateral vestibular failure (BVF). The aim of this study was to investigate event-related brain activity by functional magnetic resonance imaging (fMRI) during spatial navigation and visual memory tasks in BVF patients. Twenty-three BVF patients and healthy age- and gender matched control subjects performed learning sessions of spatial navigation by watching short films taking them through various streets from a driver's perspective along a route to the Cathedral of Cologne using virtual reality videos (adopted and modified from Google Earth). In the scanner, participants were asked to respond to questions testing for visual memory or spatial navigation while they viewed short video clips. From a similar but not identical perspective depicted video frames of routes were displayed which they had previously seen or which were completely novel to them. Compared with controls, posterior cerebellar activity in BVF patients was higher during spatial navigation than during visual memory tasks, in the absence of performance differences. This cerebellar activity correlated with disease duration. Cerebellar activity during spatial navigation in BVF patients may reflect increased non-vestibular efforts to counteract the development of spatial navigation deficits in BVF. Conceivably, cerebellar activity indicates a change in navigational strategy of BVF patients, i.e. from a more allocentric, landmark or place-based strategy (hippocampus) to a more sequence-based strategy. This interpretation would be in accord with recent evidence for a cerebellar role in sequence-based navigation. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. Cortical oscillatory activity during spatial echoic memory.

    Science.gov (United States)

    Kaiser, Jochen; Walker, Florian; Leiberg, Susanne; Lutzenberger, Werner

    2005-01-01

    In human magnetoencephalogram, we have found gamma-band activity (GBA), a putative measure of cortical network synchronization, during both bottom-up and top-down auditory processing. When sound positions had to be retained in short-term memory for 800 ms, enhanced GBA was detected over posterior parietal cortex, possibly reflecting the activation of higher sensory storage systems along the hypothesized auditory dorsal space processing stream. Additional prefrontal GBA increases suggested an involvement of central executive networks in stimulus maintenance. The present study assessed spatial echoic memory with the same stimuli but a shorter memorization interval of 200 ms. Statistical probability mapping revealed posterior parietal GBA increases at 80 Hz near the end of the memory phase and both gamma and theta enhancements in response to the test stimulus. In contrast to the previous short-term memory study, no prefrontal gamma or theta enhancements were detected. This suggests that spatial echoic memory is performed by networks along the putative auditory dorsal stream, without requiring an involvement of prefrontal executive regions.

  7. Identifying clusters of active transportation using spatial scan statistics.

    Science.gov (United States)

    Huang, Lan; Stinchcomb, David G; Pickle, Linda W; Dill, Jennifer; Berrigan, David

    2009-08-01

    There is an intense interest in the possibility that neighborhood characteristics influence active transportation such as walking or biking. The purpose of this paper is to illustrate how a spatial cluster identification method can evaluate the geographic variation of active transportation and identify neighborhoods with unusually high/low levels of active transportation. Self-reported walking/biking prevalence, demographic characteristics, street connectivity variables, and neighborhood socioeconomic data were collected from respondents to the 2001 California Health Interview Survey (CHIS; N=10,688) in Los Angeles County (LAC) and San Diego County (SDC). Spatial scan statistics were used to identify clusters of high or low prevalence (with and without age-adjustment) and the quantity of time spent walking and biking. The data, a subset from the 2001 CHIS, were analyzed in 2007-2008. Geographic clusters of significantly high or low prevalence of walking and biking were detected in LAC and SDC. Structural variables such as street connectivity and shorter block lengths are consistently associated with higher levels of active transportation, but associations between active transportation and socioeconomic variables at the individual and neighborhood levels are mixed. Only one cluster with less time spent walking and biking among walkers/bikers was detected in LAC, and this was of borderline significance. Age-adjustment affects the clustering pattern of walking/biking prevalence in LAC, but not in SDC. The use of spatial scan statistics to identify significant clustering of health behaviors such as active transportation adds to the more traditional regression analysis that examines associations between behavior and environmental factors by identifying specific geographic areas with unusual levels of the behavior independent of predefined administrative units.

  8. Geo-spatial Cognition on Human's Social Activity Space Based on Multi-scale Grids

    Directory of Open Access Journals (Sweden)

    ZHAI Weixin

    2016-12-01

    Full Text Available Widely applied location aware devices, including mobile phones and GPS receivers, have provided great convenience for collecting large volume individuals' geographical information. The researches on the human's society behavior space has attracts an increasingly number of researchers. In our research, based on location-based Flickr data From 2004 to May, 2014 in China, we choose five levels of spatial grids to form the multi-scale frame for investigate the correlation between the scale and the geo-spatial cognition on human's social activity space. The HT-index is selected as the fractal inspired by Alexander to estimate the maturity of the society activity on different scales. The results indicate that that the scale characteristics are related to the spatial cognition to a certain extent. It is favorable to use the spatial grid as a tool to control scales for geo-spatial cognition on human's social activity space.

  9. Reproductive experience modified dendritic spines on cortical pyramidal neurons to enhance sensory perception and spatial learning in rats.

    Science.gov (United States)

    Chen, Jeng-Rung; Lim, Seh Hong; Chung, Sin-Cun; Lee, Yee-Fun; Wang, Yueh-Jan; Tseng, Guo-Fang; Wang, Tsyr-Jiuan

    2017-01-27

    Behavioral adaptations during motherhood are aimed at increasing reproductive success. Alterations of hormones during motherhood could trigger brain morphological changes to underlie behavioral alterations. Here we investigated whether motherhood changes a rat's sensory perception and spatial memory in conjunction with cortical neuronal structural changes. Female rats of different statuses, including virgin, pregnant, lactating, and primiparous rats were studied. Behavioral test showed that the lactating rats were most sensitive to heat, while rats with motherhood and reproduction experience outperformed virgin rats in a water maze task. By intracellular dye injection and computer-assisted 3-dimensional reconstruction, the dendritic arbors and spines of the layer III and V pyramidal neurons of the somatosensory cortex and CA1 hippocampal pyramidal neurons were revealed for closer analysis. The results showed that motherhood and reproductive experience increased dendritic spines but not arbors or the lengths of the layer III and V pyramidal neurons of the somatosensory cortex and CA1 hippocampal pyramidal neurons. In addition, lactating rats had a higher incidence of spines than pregnant or primiparous rats. The increase of dendritic spines was coupled with increased expression of the glutamatergic postsynaptic marker protein (PSD-95), especially in lactating rats. On the basis of the present results, it is concluded that motherhood enhanced rat sensory perception and spatial memory and was accompanied by increases in dendritic spines on output neurons of the somatosensory cortex and CA1 hippocampus. The effect was sustained for at least 6 weeks after the weaning of the pups.

  10. Modulation of the Object/Background Interaction by Spatial Frequency

    Directory of Open Access Journals (Sweden)

    Yanju Ren

    2011-05-01

    Full Text Available With regard to the relationship between object and background perception in the natural scene images, functional isolation hypothesis and interactive hypothesis were proposed. Based on previous studies, the present study investigated the role of spatial frequency in the relationship between object and background perception in the natural scene images. In three experiments, participants reported the object, background, or both after seeing each picture for 500 ms followed by a mask. The authors found that (a backgrounds were identified more accurately when they contained a consistent rather than an inconsistent object, independently of spatial frequency; (b objects were identified more accurately in a consistent than an inconsistent background under the condition of low spatial frequencies but not high spatial frequencies; (c spatial frequency modulation remained when both objects and backgrounds were reported simultaneously. The authors conclude that object/background interaction is partially dependent on spatial frequency.

  11. Parents' Perceptions of Physical Activity for Their Children with Visual Impairments

    Science.gov (United States)

    Perkins, Kara; Columna, Luis; Lieberman, Lauren; Bailey, JoEllen

    2013-01-01

    Introduction: Ongoing communication with parents and the acknowledgment of their preferences and expectations are crucial to promote the participation of physical activity by children with visual impairments. Purpose: The study presented here explored parents' perceptions of physical activity for their children with visual impairments and explored…

  12. Maternal perception of fetal activity and late stillbirth risk: findings from the Auckland Stillbirth Study.

    Science.gov (United States)

    Stacey, Tomasina; Thompson, John M D; Mitchell, Edwin A; Ekeroma, Alec; Zuccollo, Jane; McCowan, Lesley M E

    2011-12-01

      Maternal perception of decreased fetal movements has been associated with adverse pregnancy outcomes, including stillbirth. Little is known about other aspects of perceived fetal activity. The objective of this study was to explore the relationship between maternal perception of fetal activity and late stillbirth (≥28 wk gestation) risk.   Participants were women with a singleton, late stillbirth without congenital abnormality, born between July 2006 and June 2009 in Auckland, New Zealand. Two control women with ongoing pregnancies were randomly selected at the same gestation at which the stillbirth occurred. Detailed demographic and fetal movement data were collected by way of interview in the first few weeks after the stillbirth, or at the equivalent gestation for control women.   A total of 155/215 (72%) women who experienced a stillbirth and 310/429 (72%) control group women consented to participate in the study. Maternal perception of increased strength and frequency of fetal movements, fetal hiccups, and frequent vigorous fetal activity were all associated with a reduced risk of late stillbirth. In contrast, perception of decreased strength of fetal movement was associated with a more than twofold increased risk of late stillbirth (aOR: 2.37; 95% CI: 1.29-4.35). A single episode of vigorous fetal activity was associated with an almost sevenfold increase in late stillbirth risk (aOR: 6.81; 95% CI: 3.01-15.41) compared with no unusually vigorous activity.   Our study suggests that maternal perception of increasing fetal activity throughout the last 3 months of pregnancy is a sign of fetal well-being, whereas perception of reduced fetal movements is associated with increased risk of late stillbirth. © 2011, Copyright the Authors. Journal compilation © 2011, Wiley Periodicals, Inc.

  13. Brain Activity Stimulated by Prism Adaptation Tasks Utilized for the Treatment of Unilateral Spatial Neglect: A Study with fNIRS

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    Hiroshi Taniguchi

    2012-01-01

    Full Text Available We investigated the neurological basis for efficacy of prism adaptation therapy, which is used for the treatment of poststroke unilateral spatial neglect (USN. Study subjects were 6 USN-positive (+, 6 USN-negative patients, and 6 healthy volunteer control subjects. USN was identified by the Behavioural Inattention Test (BIT. During the tasks, brain activity was assessed with fNIRS via changes in oxyHb concentration per unit length. There was no significant difference in the number of errors in the task between the 3 groups. However, in the USN(+ group there was a significantly greater reduction in oxyHb levels in the right parietal association cortex during the prism adaptation task than in the other 2 groups (<0.05. There was an immediate improvement in USN symptoms as well as a significant increase in oxyHb levels during the prism adaptation in the channels covering the right frontal and parietal lobes in 2 patients in the USN(+ group (<0.05. This result suggested that decreased activity in the right parietal association cortex, which is related to spatial perception, during the prism adaptation task and task-induced reorganization of the right frontal and parietal areas were involved in improvement in USN symptoms.

  14. Space perception and William James's metaphysical presuppositions.

    Science.gov (United States)

    Farrell, Martin J

    2011-05-01

    William James's overtly philosophical work may be more continuous with his psychological work than is sometimes thought. His Essays in Radical Empiricism can be understood as an explicit statement of the absolute presupposition that formed the basis of Jamesian psychology: that direct experience is primary and has to be taken at face value. An examination of James's theory of space perception suggests that, even in his early work, he presupposed the primacy of direct experience, and that later changes in his account of space perception can be understood as making his view more consistent with this presupposition. In his earlier view of space perception, James argued that sensations were directly experienced as spatial, though he accepted that spatial relations between sensations may be constructed by higher order thought. In his later view, however, James argued that spatial relations were just as directly experienced as sensations. The work of T. H. Green may have prompted James to recognize the full consequence of his ideas and to realize that taking experience at face value required that spatial relations be thought of as intrinsic to experience rather than the result of intellectual construction.

  15. The WLC principle for action-oriented perception

    Science.gov (United States)

    Arena, Paolo; Fortuna, Luigi; Lombardo, Davide; Patané, Luca; Velarde, Manuel G.

    2007-05-01

    In this paper a new methodology for action-oriented perception will be introduced. It is based on a previous method that used Turing Patterns in CNNs for the arousal of "perceptual states" as representation of the environmental condition. The emerging patterns were associated to codes which gave rise to learnable actions on a moving robot. Recently the new paradigm of Winnerless Competition (WLC) was taken into consideration to represent a suitable, bioinspired and efficient method to generate sequences of neural activations, strictly related to the spatial-temporal activity of input sensors. This fascinating property was recently peculiarly measured in the olfactory system, in particular in groups of neurons belonging to the insects' Antennal Lobe and to the mammalians' Olfactory Bulb. Taking inspiration from these experimental results and from the analytical model of the WLC, a cellular nonlinear model generating sequences of cell activation, representing the input pattern at the sensory level, will be used in an action-oriented perception framework. In fact simulation results showed the potentiality of the WLC approach to design dynamic networks for discrimination and classification, with a potentially huge memory capacity. In the present manuscript the WLC principle, implemented in a network of FitzHugh Nagumo neurons will be used within the whole framework for action-oriented perception, and the results will be applied to a roving robot.

  16. Active biofeedback changes the spatial distribution of upper trapezius muscle activity during computer work

    DEFF Research Database (Denmark)

    Samani, Afshin; Holtermann, Andreas; Søgaard, Karen

    2010-01-01

    The aim of this study was to investigate the spatio-temporal effects of advanced biofeedback by inducing active and passive pauses on the trapezius activity pattern using high-density surface electromyography (HD-EMG). Thirteen healthy male subjects performed computer work with superimposed...... benefit of superimposed muscle contraction in relation to the spatial organization of muscle activity during computer work....

  17. Perceptions of Active Learning between Faculty and Undergraduates: Differing Views among Departments

    Science.gov (United States)

    Patrick, Lorelei E.; Howell, Leigh Anne; Wischusen, William

    2016-01-01

    There have been numerous calls recently to increase the use of active learning in university science, technology, engineering, and math (STEM) classrooms to more actively engage students and enhance student learning. However, few studies have investigated faculty and student perceptions regarding the effectiveness of active learning or the…

  18. Thinking Egyptian: Active Models for Understanding Spatial Representation.

    Science.gov (United States)

    Schiferl, Ellen

    This paper highlights how introductory textbooks on Egyptian art inhibit understanding by reinforcing student preconceptions, and demonstrates another approach to discussing space with a classroom exercise and software. The alternative approach, an active model for spatial representation, introduced here was developed by adapting classroom…

  19. Hilar GABAergic interneuron activity controls spatial learning and memory retrieval.

    Directory of Open Access Journals (Sweden)

    Yaisa Andrews-Zwilling

    Full Text Available Although extensive research has demonstrated the importance of excitatory granule neurons in the dentate gyrus of the hippocampus in normal learning and memory and in the pathogenesis of amnesia in Alzheimer's disease (AD, the role of hilar GABAergic inhibitory interneurons, which control the granule neuron activity, remains unclear.We explored the function of hilar GABAergic interneurons in spatial learning and memory by inhibiting their activity through Cre-dependent viral expression of enhanced halorhodopsin (eNpHR3.0--a light-driven chloride pump. Hilar GABAergic interneuron-specific expression of eNpHR3.0 was achieved by bilaterally injecting adeno-associated virus containing a double-floxed inverted open-reading frame encoding eNpHR3.0 into the hilus of the dentate gyrus of mice expressing Cre recombinase under the control of an enhancer specific for GABAergic interneurons. In vitro and in vivo illumination with a yellow laser elicited inhibition of hilar GABAergic interneurons and consequent activation of dentate granule neurons, without affecting pyramidal neurons in the CA3 and CA1 regions of the hippocampus. We found that optogenetic inhibition of hilar GABAergic interneuron activity impaired spatial learning and memory retrieval, without affecting memory retention, as determined in the Morris water maze test. Importantly, optogenetic inhibition of hilar GABAergic interneuron activity did not alter short-term working memory, motor coordination, or exploratory activity.Our findings establish a critical role for hilar GABAergic interneuron activity in controlling spatial learning and memory retrieval and provide evidence for the potential contribution of GABAergic interneuron impairment to the pathogenesis of amnesia in AD.

  20. Cultural differences in room size perception.

    Science.gov (United States)

    Saulton, Aurelie; Bülthoff, Heinrich H; de la Rosa, Stephan; Dodds, Trevor J

    2017-01-01

    Cultural differences in spatial perception have been little investigated, which gives rise to the impression that spatial cognitive processes might be universal. Contrary to this idea, we demonstrate cultural differences in spatial volume perception of computer generated rooms between Germans and South Koreans. We used a psychophysical task in which participants had to judge whether a rectangular room was larger or smaller than a square room of reference. We systematically varied the room rectangularity (depth to width aspect ratio) and the viewpoint (middle of the short wall vs. long wall) from which the room was viewed. South Koreans were significantly less biased by room rectangularity and viewpoint than their German counterparts. These results are in line with previous notions of general cognitive processing strategies being more context dependent in East Asian societies than Western ones. We point to the necessity of considering culturally-specific cognitive processing strategies in visual spatial cognition research.

  1. Cultural differences in room size perception.

    Directory of Open Access Journals (Sweden)

    Aurelie Saulton

    Full Text Available Cultural differences in spatial perception have been little investigated, which gives rise to the impression that spatial cognitive processes might be universal. Contrary to this idea, we demonstrate cultural differences in spatial volume perception of computer generated rooms between Germans and South Koreans. We used a psychophysical task in which participants had to judge whether a rectangular room was larger or smaller than a square room of reference. We systematically varied the room rectangularity (depth to width aspect ratio and the viewpoint (middle of the short wall vs. long wall from which the room was viewed. South Koreans were significantly less biased by room rectangularity and viewpoint than their German counterparts. These results are in line with previous notions of general cognitive processing strategies being more context dependent in East Asian societies than Western ones. We point to the necessity of considering culturally-specific cognitive processing strategies in visual spatial cognition research.

  2. The hippocampus and visual perception

    Science.gov (United States)

    Lee, Andy C. H.; Yeung, Lok-Kin; Barense, Morgan D.

    2012-01-01

    In this review, we will discuss the idea that the hippocampus may be involved in both memory and perception, contrary to theories that posit functional and neuroanatomical segregation of these processes. This suggestion is based on a number of recent neuropsychological and functional neuroimaging studies that have demonstrated that the hippocampus is involved in the visual discrimination of complex spatial scene stimuli. We argue that these findings cannot be explained by long-term memory or working memory processing or, in the case of patient findings, dysfunction beyond the medial temporal lobe (MTL). Instead, these studies point toward a role for the hippocampus in higher-order spatial perception. We suggest that the hippocampus processes complex conjunctions of spatial features, and that it may be more appropriate to consider the representations for which this structure is critical, rather than the cognitive processes that it mediates. PMID:22529794

  3. The hippocampus and visual perception

    Directory of Open Access Journals (Sweden)

    Andy C. H. Lee

    2012-04-01

    Full Text Available In this review, we will discuss the idea that the hippocampus may be involved in both memory and perception, contrary to theories that posit functional and neuroanatomical segregation of these processes. This suggestion is based on a number of recent neuropsychological and functional neuroimaging studies that have demonstrated that the hippocampus is involved in the visual discrimination of complex spatial scene stimuli. We argue that these findings cannot be explained by long-term memory or working memory processing or, in the case of patient findings, dysfunction beyond the medial temporal lobe. Instead, these studies point towards a role for the hippocampus in higher-order spatial perception. We suggest that the hippocampus processes complex conjunctions of spatial features, and that it may be more appropriate to consider the representations for which this structure is critical, rather than the cognitive processes that it mediates.

  4. Synchronous retinotopic frontal-temporal activity during long-term memory for spatial location.

    Science.gov (United States)

    Slotnick, Scott D

    2010-05-12

    Early visual areas in occipital cortex are known to be retinotopic. Recently, retinotopic maps have been reported in frontal and parietal cortex during spatial attention and working memory. The present event-related potential (ERP) and functional magnetic resonance imaging (fMRI) study determined whether spatial long-term memory was associated with retinotopic activity in frontal and parietal regions, and assessed whether retinotopic activity in these higher level control regions was synchronous with retinotopic activity in lower level visual sensory regions. During encoding, abstract shapes were presented to the left or right of fixation. During retrieval, old and new shapes were presented at fixation and participants classified each shape as old and previously on the "left", old and previously on the "right", or "new". Retinotopic effects were manifested by accurate memory for items previously presented on the left producing activity in the right hemisphere and accurate memory for items previously presented on the right producing activity in the left hemisphere. Retinotopic ERP activity was observed in frontal regions and visual sensory (occipital and temporal) regions. In frontal cortex, retinotopic fMRI activity was localized to the frontal eye fields. There were no significant ERP or fMRI retinotopic memory effects in parietal regions. The present long-term memory retinotopic effects complement previous spatial attention and working memory findings (and suggest retinotopic activity in parietal cortex may require an external peripheral stimulus). Furthermore, ERP cross-correlogram analysis revealed that retinotopic activations in frontal and temporal regions were synchronous, indicating that these regions interact during retrieval of spatial information. (c) 2010 Elsevier B.V. All rights reserved.

  5. Spatial Frequency Discrimination : Effects of Age, Reward, and Practice

    NARCIS (Netherlands)

    van den Boomen, Carlijn; Peters, Judith Carolien

    2017-01-01

    Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of

  6. Spatial Frequency Discrimination : Effects of Age, Reward, and Practice

    NARCIS (Netherlands)

    van den Boomen, Carlijn; Peters, Judith Carolien

    Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of

  7. The Effects of Spatial Enclosure on Social Interaction Between Older Adults With Dementia and Young Children.

    Science.gov (United States)

    Cerruti, Minyoung S; Shepley, Mardelle M

    2016-04-01

    To examine the impact of spatial enclosures on social interaction between older adults with early stage dementia and young children. Intergenerational interaction through meaningful activities can promote positive affects and behaviors of children and older adults. The development of social interaction is closely related to the physical environment in association with personal competence of older adults with dementia and young children. However, minimal attention has been given to the role of physical environment in influencing intergenerational interaction. A quasi-experiment examined the functional relationship between the amount of spatial enclosure and the types of social behaviors of older adults with dementia and young children. Semi-structured interviews, aided by a photographic simulation, were developed to explore the participants' perceptions of and experiences with the different degrees of spatial enclosure. Findings showed that the semienclosed spatial plan impacted both prosocial and antisocial behaviors of older adults with dementia in their interactions with young children. This apparent discrepancy was associated with two conflicting perceptions: a sense of openness and the lack of control due to distraction created by the loose visual boundary. There was no correlation between the elder-child neutral behaviors and the degrees of spatial enclosure. This study suggests that spaces with moderate openness without visual and acoustic distraction are the most desirable to promote prosocial behaviors of older adults with dementia and young children. Additionally, elder-child prosocial behaviors were likely facilitated by specific design features such as adequate personal space, the perception of openness, and possible spaces that provide both prospect and refuge in relation to spatial enclosure. © The Author(s) 2016.

  8. Hilar GABAergic Interneuron Activity Controls Spatial Learning and Memory Retrieval

    Science.gov (United States)

    Andrews-Zwilling, Yaisa; Gillespie, Anna K.; Kravitz, Alexxai V.; Nelson, Alexandra B.; Devidze, Nino; Lo, Iris; Yoon, Seo Yeon; Bien-Ly, Nga; Ring, Karen; Zwilling, Daniel; Potter, Gregory B.; Rubenstein, John L. R.; Kreitzer, Anatol C.; Huang, Yadong

    2012-01-01

    Background Although extensive research has demonstrated the importance of excitatory granule neurons in the dentate gyrus of the hippocampus in normal learning and memory and in the pathogenesis of amnesia in Alzheimer's disease (AD), the role of hilar GABAergic inhibitory interneurons, which control the granule neuron activity, remains unclear. Methodology and Principal Findings We explored the function of hilar GABAergic interneurons in spatial learning and memory by inhibiting their activity through Cre-dependent viral expression of enhanced halorhodopsin (eNpHR3.0)—a light-driven chloride pump. Hilar GABAergic interneuron-specific expression of eNpHR3.0 was achieved by bilaterally injecting adeno-associated virus containing a double-floxed inverted open-reading frame encoding eNpHR3.0 into the hilus of the dentate gyrus of mice expressing Cre recombinase under the control of an enhancer specific for GABAergic interneurons. In vitro and in vivo illumination with a yellow laser elicited inhibition of hilar GABAergic interneurons and consequent activation of dentate granule neurons, without affecting pyramidal neurons in the CA3 and CA1 regions of the hippocampus. We found that optogenetic inhibition of hilar GABAergic interneuron activity impaired spatial learning and memory retrieval, without affecting memory retention, as determined in the Morris water maze test. Importantly, optogenetic inhibition of hilar GABAergic interneuron activity did not alter short-term working memory, motor coordination, or exploratory activity. Conclusions and Significance Our findings establish a critical role for hilar GABAergic interneuron activity in controlling spatial learning and memory retrieval and provide evidence for the potential contribution of GABAergic interneuron impairment to the pathogenesis of amnesia in AD. PMID:22792368

  9. College students’ perceptions of a caring climate in group physical activity classes

    Directory of Open Access Journals (Sweden)

    Newland Aubrey

    2017-02-01

    Full Text Available Study aim: Research suggests that physical activity rates decline sharply after high school. The pattern of activity or inactivity during college tends to persist into adulthood. A critical need exists for examination of strategies to engage college-age students in physical activity habits. One way to do this is through physical activity courses offered in colleges. This study examines the relationship between perceptions of a caring psychological climate and group connectedness, enjoyment, and attitudes toward classmates and the instructor in group physical activity courses. Material and methods: Participants were 174 students (107 males and 67 females; Mage = 21.71 enrolled in exercise, martial arts, and sports courses at a large university in the Mountain West. Results: Perceptions of a caring climate were significantly related to enhanced feelings of group connectedness, heightened enjoyment, and more positive attitudes toward classmates and instructor. Discussion: These findings suggest that a strategy to foster engagement in physical activity courses on campus is to train instructors to value, support, and welcome students.

  10. Levels and properties of map perception

    Directory of Open Access Journals (Sweden)

    Żyszkowska Wiesława

    2017-03-01

    Full Text Available Map perception consists of numerous processes of information processing, taking place almost simultaneously at different levels and stages which makes it conditioned by many factors. In the article, a review of processes related to the perception of a map as well as levels and properties of perception which impact its course and the nature of information obtained from a map is presented. The most important process constituting the basis of a map perception is a visual search (eye movement. However, as stated based on the studies, the process is individual depending on the purpose of map perception and it may be guided by its image (visual search guidance or by the knowledge of users (cognitive search guidance. Perception can take place according to various schemes – “local-to-global” or “global-to-local”, or in accordance with the guided search theory. Perception is divided into three processes: perceiving, distinguishing and identifying, which constitute the basis to interpret and understand a map. They are related to various degrees of intellectual involvement of the user and to various levels of questions concerning the relations between signs and their content. Identification involves referring a sign to its explanation in the legend. Interpretation means transformation of the initial information collected from the map into derivative information in which two basic types of understanding take place: deductive and inductive. Identification of geographical space objects on the map and the interpretation of its content constitute the basis to introduce information into memory structures. In the brain a resource of information is generated called geographic knowledge or spatial representation (mental map which may have a double nature – verbal or pictorial. An important feature of mental maps is organization of spatial information into hierarchical structures, e.g. grouping towns into regions as well as deformation of spatial

  11. County-Scale Spatial Distribution of Soil Enzyme Activities and Enzyme Activity Indices in Agricultural Land: Implications for Soil Quality Assessment

    Directory of Open Access Journals (Sweden)

    Xiangping Tan

    2014-01-01

    Full Text Available Here the spatial distribution of soil enzymatic properties in agricultural land was evaluated on a county-wide (567 km2 scale in Changwu, Shaanxi Province, China. The spatial variations in activities of five hydrolytic enzymes were examined using geostatistical methods. The relationships between soil enzyme activities and other soil properties were evaluated using both an integrated total enzyme activity index (TEI and the geometric mean of enzyme activities (GME. At the county scale, soil invertase, phosphatase, and catalase activities were moderately spatially correlated, whereas urease and dehydrogenase activities were weakly spatially correlated. Correlation analysis showed that both TEI and GME were better correlated with selected soil physicochemical properties than single enzyme activities. Multivariate regression analysis showed that soil OM content had the strongest positive effect while soil pH had a negative effect on the two enzyme activity indices. In addition, total phosphorous content had a positive effect on TEI and GME in orchard soils, whereas alkali-hydrolyzable nitrogen and available potassium contents, respectively, had negative and positive effects on these two enzyme indices in cropland soils. The results indicate that land use changes strongly affect soil enzyme activities in agricultural land, where TEI provides a sensitive biological indicator for soil quality.

  12. Action during body perception: processing time affects self-other correspondences.

    Science.gov (United States)

    Reed, Catherine L; McGoldrick, John E

    2007-01-01

    The accurate perception of other people and their postures is essential for functioning in a social world. Our own bodies organize information from others to help us respond appropriately by creating self-other mappings between bodies. In this study, we investigated mechanisms involved in the processing of self-other correspondences. Reed and Farah (1995) showed that a multimodal, articulated body representation containing the spatial relations among parts of the human body was accessed by both viewing another's body and moving one's own. Use of one part of the body representation facilitated the perception of homologous areas of other people's bodies, suggesting that inputs from both the self and other activated the shared body representation. Here we investigated whether this self-other correspondence produced rapid facilitation or required additional processing time to resolve competing inputs for a shared body representation. Using a modified Reed and Farah dual-task paradigm, we found that processing time influenced body-position memory: an interaction between body-part moved and body-part attended revealed a relative facilitation effect at the 5 s ISI, but interference at the 2 s ISI. Our results suggest that effective visual-motor integration from the self and other requires time to activate shared portions of the spatial body representation.

  13. Hippocampal spatial mechanisms relate to the development of arithmetic symbol processing in children.

    Science.gov (United States)

    Mathieu, Romain; Epinat-Duclos, Justine; Léone, Jessica; Fayol, Michel; Thevenot, Catherine; Prado, Jérôme

    2017-06-13

    Understanding the meaning of abstract mathematical symbols is a cornerstone of arithmetic learning in children. Studies have long focused on the role of spatial intuitions in the processing of numerals. However, it has been argued that such intuitions may also underlie symbols that convey fundamental arithmetic concepts, such as arithmetic operators. In the present cross-sectional study, we used fMRI to investigate how and when associations between arithmetic operators and brain regions processing spatial information emerge in children from 3 rd to 10 th grade. We found that the mere perception of a '+' sign elicited grade-related increases of spatial activity in the right hippocampus. That is, merely perceiving '+' signs - without any operands - elicited enhanced hippocampal activity after around 7 th grade (12-13 years old). In these children, hippocampal activity in response to a '+' sign was further correlated with the degree to which calculation performance was facilitated by the preview of that sign before an addition problem, an effect termed operator-priming. Grade-related increases of hippocampal spatial activity were operation-specific because they were not observed with '×' signs, which might evoke rote retrieval rather than numerical manipulation. Our study raises the possibility that hippocampal spatial mechanisms help build associations between some arithmetic operators and space throughout age and/or education. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Barriers Affecting Physical Activity in Rural Communities: Perceptions of Parents and Children

    Science.gov (United States)

    McWhinney, Sharon; McDonald, Andrea; Dawkins-Moultin, Lenna; Outley, Corliss; McKyer, E. Lisako; Thomas, Audrene

    2011-01-01

    A comprehensive understanding of the barriers inhibiting physical activity among children is critical in the fight against childhood obesity. This qualitative interview study examined parents' and children's perceptions of the barriers to physical activity in rural communities of low socioeconomic status. Parents and children concurred that the…

  15. Spatial distribution of enzyme activities along the root and in the rhizosphere of different plants

    Science.gov (United States)

    Razavi, Bahar S.; Zarebanadkouki, Mohsen; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2015-04-01

    Extracellular enzymes are important for decomposition of many biological macromolecules abundant in soil such as cellulose, hemicelluloses and proteins. Activities of enzymes produced by both plant roots and microbes are the primary biological drivers of organic matter decomposition and nutrient cycling. So far acquisition of in situ data about local activity of different enzymes in soil has been challenged. That is why there is an urgent need in spatially explicit methods such as 2-D zymography to determine the variation of enzymes along the roots in different plants. Here, we developed further the zymography technique in order to quantitatively visualize the enzyme activities (Spohn and Kuzyakov, 2013), with a better spatial resolution We grew Maize (Zea mays L.) and Lentil (Lens culinaris) in rhizoboxes under optimum conditions for 21 days to study spatial distribution of enzyme activity in soil and along roots. We visualized the 2D distribution of the activity of three enzymes:β-glucosidase, leucine amino peptidase and phosphatase, using fluorogenically labelled substrates. Spatial resolution of fluorescent images was improved by direct application of a substrate saturated membrane to the soil-root system. The newly-developed direct zymography shows different pattern of spatial distribution of enzyme activity along roots and soil of different plants. We observed a uniform distribution of enzyme activities along the root system of Lentil. However, root system of Maize demonstrated inhomogeneity of enzyme activities. The apical part of an individual root (root tip) in maize showed the highest activity. The activity of all enzymes was the highest at vicinity of the roots and it decreased towards the bulk soil. Spatial patterns of enzyme activities as a function of distance from the root surface were enzyme specific, with highest extension for phosphatase. We conclude that improved zymography is promising in situ technique to analyze, visualize and quantify

  16. Is the perception of time pressure a barrier to healthy eating and physical activity among women?

    Science.gov (United States)

    Welch, Nicky; McNaughton, Sarah A; Hunter, Wendy; Hume, Clare; Crawford, David

    2009-07-01

    To describe the proportion of women reporting time is a barrier to healthy eating and physical activity, the characteristics of these women and the perceived causes of time pressure, and to examine associations between perceptions of time as a barrier and consumption of fruit, vegetables and fast food, and physical activity. A cross-sectional survey of food intake, physical activity and perceived causes of time pressure. A randomly selected community sample. A sample of 1580 women self-reported their food intake and their perceptions of the causes of time pressure in relation to healthy eating. An additional 1521 women self-reported their leisure-time physical activity and their perceptions of the causes of time pressure in relation to physical activity. Time pressure was reported as a barrier to healthy eating by 41% of the women and as a barrier to physical activity by 73%. Those who reported time pressure as a barrier to healthy eating were significantly less likely to meet fruit, vegetable and physical activity recommendations, and more likely to eat fast food more frequently. Women reporting time pressure as a barrier to healthy eating and physical activity are less likely to meet recommendations than are women who do not see time pressure as a barrier. Further research is required to understand the perception of time pressure issues among women and devise strategies to improve women's food and physical activity behaviours.

  17. Multimodal sensory integration during sequential eating--linking chewing activity, aroma release, and aroma perception over time.

    Science.gov (United States)

    Leclercq, Ségolène; Blancher, Guillaume

    2012-10-01

    The respective effects of chewing activity, aroma release from a gelled candy, and aroma perception were investigated. Specifically, the study aimed at 1) comparing an imposed chewing and swallowing pattern (IP) and free protocol (FP) on panelists for in vivo measurements, 2) investigating carryover effects in sequential eating, and 3) studying the link between instrumental data and their perception counterpart. Chewing activity, in-nose aroma concentration, and aroma perception over time were measured by electromyography, proton transfer reaction-mass spectrometry, and time intensity, respectively. Model gel candies were flavored at 2 intensity levels (low-L and high-H). The panelists evaluated 3 sequences (H then H, H then L, and L then H) in duplicates with both IP and FP. They scored aroma intensity over time while their in-nose aroma concentrations and their chewing activity were measured. Overall, only limited advantages were found in imposing a chewing and swallowing pattern for instrumental and sensory data. In addition, the study highlighted the role of brain integration on perceived intensity and dynamics of perception, in the framework of sequential eating without rinsing. Because of the presence of adaptation phenomena, contrast effect, and potential taste and texture cross-modal interaction with aroma perception, it was concluded that dynamic in-nose concentration data provide only one part of the perception picture and therefore cannot be used alone in prediction models.

  18. Lamp spectrum and spatial brightness at photopic levels

    DEFF Research Database (Denmark)

    Fotios, Steve; Atli, Deniz; Cheal, Chris

    2015-01-01

    Light sources are available in a variety of spectral power distributions (SPDs) and this affects spatial brightness in a manner not predicted by quantities such as illuminance. Tuning light source SPD to better match the sensitivity of visual perception may allow the same spatial brightness but a...

  19. Setting them up for lifetime activity: Play competence perceptions and physical activity in young children.

    Science.gov (United States)

    Barnett, Lisa M; Ridgers, Nicola D; Hesketh, Kylie; Salmon, Jo

    2017-09-01

    Possessing positive physical perceived competence is important for physical activity in older children. Young children are primarily physically active through play-based behaviour rather than through organised sports and activities, so understanding how play perceptions might influence physical activity behaviour is important. The study purpose was to assess if perceived active play competence is associated with young children's physical activity. Cross sectional study. This paper uses two different samples drawn from the same Australian city, both collected in 2013. The first sample included 152 children (49% boys) aged 4-5 years (M=4.7, SD=0.47), the second sample included 78 children (55% boys) aged 5-8 years (M=6.6, SD=0.93). The Pictorial Scale of Perceived Movement Skill Competence was used to assess children's perceived competence in six skill-related play activities. Moderate- to vigorous-intensity physical activity (MVPA) was assessed for 8 consecutive days via accelerometers. A general linear model with the mean minutes in MVPA per day as the outcome, perceived play competence as the independent variable and adjusting for relevant confounders was performed in each sample. Perceived active play competence was not related to MVPA min/day (B=0.44, p=0.323) in the younger sample, but was in the older sample (B=1.53, p=0.026), explaining 24% of adjusted variance. Positive findings in the older sample show school-aged children need exposure to play based activities in order to develop the positive self-perception needed to engage in MVPA every day. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  20. Maturational differences in physical self- perceptions and the relationship with physical activity in early adolescent girls.

    Science.gov (United States)

    Niven, Alisa G; Fawkner, Samantha G; Knowles, Anne-Marie; Stephenson, Claire

    2007-11-01

    This cross-sectional study examined the relationship between physical self-perceptions (PSPs), maturation, and physical activity and compared the strength of the relationships of biological and chronological age with PSPs in early adolescent girls (N = 208; mean age = 11.83 +/- 0.39 years). Participants completed the Physical Activity Questionnaire for Older Children, the Children's Physical Self-Perception Profile, and the Pubertal Development Scale. Results indicated that PSPs were significantly and moderately correlated with physical activity. There were no differences in physical activity between maturation stages. Girls who were in the early stages of maturation had significantly more positive perceptions of body attractiveness and physical self-worth than girls in the mid stages of maturation. There was no evidence of a relationship between PSPs and chronological age. This study provided further support for the relationship between PSPs and physical activity and the relationship between maturation and aspects of PSPs. In this age group, maturation does not appear to be related to physical activity or the PSPs most strongly influential on physical activity behavior.

  1. Hypnosis and pain perception: An Activation Likelihood Estimation (ALE) meta-analysis of functional neuroimaging studies.

    Science.gov (United States)

    Del Casale, Antonio; Ferracuti, Stefano; Rapinesi, Chiara; De Rossi, Pietro; Angeletti, Gloria; Sani, Gabriele; Kotzalidis, Georgios D; Girardi, Paolo

    2015-12-01

    Several studies reported that hypnosis can modulate pain perception and tolerance by affecting cortical and subcortical activity in brain regions involved in these processes. We conducted an Activation Likelihood Estimation (ALE) meta-analysis on functional neuroimaging studies of pain perception under hypnosis to identify brain activation-deactivation patterns occurring during hypnotic suggestions aiming at pain reduction, including hypnotic analgesic, pleasant, or depersonalization suggestions (HASs). We searched the PubMed, Embase and PsycInfo databases; we included papers published in peer-reviewed journals dealing with functional neuroimaging and hypnosis-modulated pain perception. The ALE meta-analysis encompassed data from 75 healthy volunteers reported in 8 functional neuroimaging studies. HASs during experimentally-induced pain compared to control conditions correlated with significant activations of the right anterior cingulate cortex (Brodmann's Area [BA] 32), left superior frontal gyrus (BA 6), and right insula, and deactivation of right midline nuclei of the thalamus. HASs during experimental pain impact both cortical and subcortical brain activity. The anterior cingulate, left superior frontal, and right insular cortices activation increases could induce a thalamic deactivation (top-down inhibition), which may correlate with reductions in pain intensity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. The Effect of Melodic Activity, Tempo Change, and Audible Beat on Tempo Perception of Elementary School Students.

    Science.gov (United States)

    Kuhn, Terry Lee; Booth, Gregory D.

    1988-01-01

    Investigated the influence of melodic activity (ornamented and plain) on students' perception of tempo. Third, fifth, and sixth graders indicated whether the tempo of the second example in each paired comparison item was faster, slower, or stayed the same. Suggests that tempo perception lessons be preceded by instruction on melodic activity and…

  3. Spatial patterns of high Aedes aegypti oviposition activity in northwestern Argentina.

    Directory of Open Access Journals (Sweden)

    Elizabet Lilia Estallo

    Full Text Available BACKGROUND: In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. METHODOLOGY: Oviposition activity was detected in Orán City (Salta province using ovitraps, weekly replaced (October 2005-2007. Spatial autocorrelation was measured with Moran's Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. PRINCIPAL FINDINGS: Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC=0.77, obtaining 99% of sensitivity and 75.29% of specificity. CONCLUSIONS: Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist

  4. Spatial Disorientation Training – Demonstration and Avoidance

    NARCIS (Netherlands)

    Bles, W.

    2008-01-01

    Acclimatization ; Aerospace medicine ; Attitude indicators ; Aviation accidents ; Flight maneuvers ; Flight simulators ; Human factors engineering ; Orientation ; Perception ; Physiological effects ; Pilot training ; Pilots (personnel) ; Responses ; Reviews ; Situational awareness ; Spatial

  5. Spatial attention enhances the selective integration of activity from area MT.

    Science.gov (United States)

    Masse, Nicolas Y; Herrington, Todd M; Cook, Erik P

    2012-09-01

    Distinguishing which of the many proposed neural mechanisms of spatial attention actually underlies behavioral improvements in visually guided tasks has been difficult. One attractive hypothesis is that attention allows downstream neural circuits to selectively integrate responses from the most informative sensory neurons. This would allow behavioral performance to be based on the highest-quality signals available in visual cortex. We examined this hypothesis by asking how spatial attention affects both the stimulus sensitivity of middle temporal (MT) neurons and their corresponding correlation with behavior. Analyzing a data set pooled from two experiments involving four monkeys, we found that spatial attention did not appreciably affect either the stimulus sensitivity of the neurons or the correlation between their activity and behavior. However, for those sessions in which there was a robust behavioral effect of attention, focusing attention inside the neuron's receptive field significantly increased the correlation between these two metrics, an indication of selective integration. These results suggest that, similar to mechanisms proposed for the neural basis of perceptual learning, the behavioral benefits of focusing spatial attention are attributable to selective integration of neural activity from visual cortical areas by their downstream targets.

  6. Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Amir Kheradmand

    2017-10-01

    Full Text Available We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such “orientation constancy” is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i neurobehavioral aspects of orientation constancy, (ii sensory models that address the neurophysiology underlying perception of upright, and (iii the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function.

  7. Brain activity during auditory and visual phonological, spatial and simple discrimination tasks.

    Science.gov (United States)

    Salo, Emma; Rinne, Teemu; Salonen, Oili; Alho, Kimmo

    2013-02-16

    We used functional magnetic resonance imaging to measure human brain activity during tasks demanding selective attention to auditory or visual stimuli delivered in concurrent streams. Auditory stimuli were syllables spoken by different voices and occurring in central or peripheral space. Visual stimuli were centrally or more peripherally presented letters in darker or lighter fonts. The participants performed a phonological, spatial or "simple" (speaker-gender or font-shade) discrimination task in either modality. Within each modality, we expected a clear distinction between brain activations related to nonspatial and spatial processing, as reported in previous studies. However, within each modality, different tasks activated largely overlapping areas in modality-specific (auditory and visual) cortices, as well as in the parietal and frontal brain regions. These overlaps may be due to effects of attention common for all three tasks within each modality or interaction of processing task-relevant features and varying task-irrelevant features in the attended-modality stimuli. Nevertheless, brain activations caused by auditory and visual phonological tasks overlapped in the left mid-lateral prefrontal cortex, while those caused by the auditory and visual spatial tasks overlapped in the inferior parietal cortex. These overlapping activations reveal areas of multimodal phonological and spatial processing. There was also some evidence for intermodal attention-related interaction. Most importantly, activity in the superior temporal sulcus elicited by unattended speech sounds was attenuated during the visual phonological task in comparison with the other visual tasks. This effect might be related to suppression of processing irrelevant speech presumably distracting the phonological task involving the letters. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. "No Time to Play": Perceptions toward Physical Activity in Youth with Cystic Fibrosis

    Science.gov (United States)

    Moola, Fiona; Faulkner, Guy E. J.; Schneiderman, Jane E.

    2012-01-01

    Although physical activity may reduce lung function decline in youth with cystic fibrosis (CF), most patients are inactive. Little is known about why youth with CF are inactive or how to facilitate physical activity. This study explored perceptions toward physical activity in 14 youth with CF at a Canadian Hospital. Qualitative interviews were…

  9. Pre-Service Physics Teachers’ Perception toward Hands-on Lab Activity and 21st Century Skills

    Science.gov (United States)

    Putri, D. H.; Risdianto, E.; Sutarno, S.

    2017-09-01

    This study aimed to describe the hands-on lab activities and 21st century skills of pre-service physics teachers at a university in Bengkulu. The respondents of this study were 113 students who have been finished and were following the laboratory course. The research instrument was questionnaire. The explored aspects of laboratory activities were motivation, the importance of laboratory activities, equipment, laboratory activities process, suitability of curriculum, assessment, laboratory design, and the 21st century skills training. The 21st century skills explored consist of learning and innovation skills, life and careers skills, and media, information and technology skills. The data obtained will be analyzed descriptively. Based on the results of data analysis was obtained that they have a good perception toward the aspect of motivation, the importance of hands-on lab activities, and laboratory activities process; and the perception was fair for other aspects. The lowest perception score was obtained in the aspects of the 21st century skills training. This result was in accordance with the 21st century skills of pre-service physics teachers which were still in moderate category. So it is necessary to develop a model of laboratory activities design that can training and enhancing the 21st century skills for pre-service physics teachers.

  10. Schools, Air Pollution, and Active Transportation: An Exploratory Spatial Analysis of Calgary, Canada.

    Science.gov (United States)

    Bertazzon, Stefania; Shahid, Rizwan

    2017-07-25

    An exploratory spatial analysis investigates the location of schools in Calgary (Canada) in relation to air pollution and active transportation options. Air pollution exhibits marked spatial variation throughout the city, along with distinct spatial patterns in summer and winter; however, all school locations lie within low to moderate pollution levels. Conversely, the study shows that almost half of the schools lie in low walkability locations; likewise, transitability is low for 60% of schools, and only bikability is widespread, with 93% of schools in very bikable locations. School locations are subsequently categorized by pollution exposure and active transportation options. This analysis identifies and maps schools according to two levels of concern: schools in car-dependent locations and relatively high pollution; and schools in locations conducive of active transportation, yet exposed to relatively high pollution. The findings can be mapped and effectively communicated to the public, health practitioners, and school boards. The study contributes with an explicitly spatial approach to the intra-urban public health literature. Developed for a moderately polluted city, the methods can be extended to more severely polluted environments, to assist in developing spatial public health policies to improve respiratory outcomes, neurodevelopment, and metabolic and attention disorders in school-aged children.

  11. Schools, Air Pollution, and Active Transportation: An Exploratory Spatial Analysis of Calgary, Canada

    Science.gov (United States)

    Bertazzon, Stefania; Shahid, Rizwan

    2017-01-01

    An exploratory spatial analysis investigates the location of schools in Calgary (Canada) in relation to air pollution and active transportation options. Air pollution exhibits marked spatial variation throughout the city, along with distinct spatial patterns in summer and winter; however, all school locations lie within low to moderate pollution levels. Conversely, the study shows that almost half of the schools lie in low walkability locations; likewise, transitability is low for 60% of schools, and only bikability is widespread, with 93% of schools in very bikable locations. School locations are subsequently categorized by pollution exposure and active transportation options. This analysis identifies and maps schools according to two levels of concern: schools in car-dependent locations and relatively high pollution; and schools in locations conducive of active transportation, yet exposed to relatively high pollution. The findings can be mapped and effectively communicated to the public, health practitioners, and school boards. The study contributes with an explicitly spatial approach to the intra-urban public health literature. Developed for a moderately polluted city, the methods can be extended to more severely polluted environments, to assist in developing spatial public health policies to improve respiratory outcomes, neurodevelopment, and metabolic and attention disorders in school-aged children. PMID:28757577

  12. An fMRI study of sex differences in regional activation to a verbal and a spatial task.

    Science.gov (United States)

    Gur, R C; Alsop, D; Glahn, D; Petty, R; Swanson, C L; Maldjian, J A; Turetsky, B I; Detre, J A; Gee, J; Gur, R E

    2000-09-01

    Sex differences in cognitive performance have been documented, women performing better on some phonological tasks and men on spatial tasks. An earlier fMRI study suggested sex differences in distributed brain activation during phonological processing, with bilateral activation seen in women while men showed primarily left-lateralized activation. This blood oxygen level-dependent fMRI study examined sex differences (14 men, 13 women) in activation for a spatial task (judgment of line orientation) compared to a verbal-reasoning task (analogies) that does not typically show sex differences. Task difficulty was manipulated. Hypothesized ROI-based analysis documented the expected left-lateralized changes for the verbal task in the inferior parietal and planum temporal regions in both men and women, but only men showed right-lateralized increase for the spatial task in these regions. Image-based analysis revealed a distributed network of cortical regions activated by the tasks, which consisted of the lateral frontal, medial frontal, mid-temporal, occipitoparietal, and occipital regions. The activation was more left lateralized for the verbal and more right for the spatial tasks, but men also showed some left activation for the spatial task, which was not seen in women. Increased task difficulty produced more distributed activation for the verbal and more circumscribed activation for the spatial task. The results suggest that failure to activate the appropriate hemisphere in regions directly involved in task performance may explain certain sex differences in performance. They also extend, for a spatial task, the principle that bilateral activation in a distributed cognitive system underlies sex differences in performance. Copyright 2000 Academic Press.

  13. Effects of dynamic range compression on spatial selective auditory attention in normal-hearing listeners.

    Science.gov (United States)

    Schwartz, Andrew H; Shinn-Cunningham, Barbara G

    2013-04-01

    Many hearing aids introduce compressive gain to accommodate the reduced dynamic range that often accompanies hearing loss. However, natural sounds produce complicated temporal dynamics in hearing aid compression, as gain is driven by whichever source dominates at a given moment. Moreover, independent compression at the two ears can introduce fluctuations in interaural level differences (ILDs) important for spatial perception. While independent compression can interfere with spatial perception of sound, it does not always interfere with localization accuracy or speech identification. Here, normal-hearing listeners reported a target message played simultaneously with two spatially separated masker messages. We measured the amount of spatial separation required between the target and maskers for subjects to perform at threshold in this task. Fast, syllabic compression that was independent at the two ears increased the required spatial separation, but linking the compressors to provide identical gain to both ears (preserving ILDs) restored much of the deficit caused by fast, independent compression. Effects were less clear for slower compression. Percent-correct performance was lower with independent compression, but only for small spatial separations. These results may help explain differences in previous reports of the effect of compression on spatial perception of sound.

  14. Sticking with the nice guy: trait warmth information impairs learning and modulates person perception brain network activity.

    Science.gov (United States)

    Lee, Victoria K; Harris, Lasana T

    2014-12-01

    Social learning requires inferring social information about another person, as well as evaluating outcomes. Previous research shows that prior social information biases decision making and reduces reliance on striatal activity during learning (Delgado, Frank, & Phelps, Nature Neuroscience 8 (11): 1611-1618, 2005). A rich literature in social psychology on person perception demonstrates that people spontaneously infer social information when viewing another person (Fiske & Taylor, 2013) and engage a network of brain regions, including the medial prefrontal cortex, temporal parietal junction, superior temporal sulcus, and precuneus (Amodio & Frith, Nature Reviews Neuroscience, 7(4), 268-277, 2006; Haxby, Gobbini, & Montgomery, 2004; van Overwalle Human Brain Mapping, 30, 829-858, 2009). We investigate the role of these brain regions during social learning about well-established dimensions of person perception-trait warmth and trait competence. We test the hypothesis that activity in person perception brain regions interacts with learning structures during social learning. Participants play an investment game where they must choose an agent to invest on their behalf. This choice is guided by cues signaling trait warmth or trait competence based on framing of monetary returns. Trait warmth information impairs learning about human but not computer agents, while trait competence information produces similar learning rates for human and computer agents. We see increased activation to warmth information about human agents in person perception brain regions. Interestingly, activity in person perception brain regions during the decision phase negatively predicts activity in the striatum during feedback for trait competence inferences about humans. These results suggest that social learning may engage additional processing within person perception brain regions that hampers learning in economic contexts.

  15. Online Collaborative Learning Activities: The Perceptions of Culturally Diverse Graduate Students

    Science.gov (United States)

    Kumi-Yeboah, Alex; Yuan, Guangji; Dogbey, James

    2017-01-01

    This exploratory study examined the perceptions of minority graduate students toward online collaborative learning activities. The participants were 20 minority graduate students from diverse cultural backgrounds (10 African Americans, 5 Hispanics, and 5 international students from Africa) enrolled in online graduate instructional technology and…

  16. Perceptual asymmetry in texture perception.

    OpenAIRE

    Williams, D; Julesz, B

    1992-01-01

    A fundamental property of human visual perception is our ability to distinguish between textures. A concerted effort has been made to account for texture segregation in terms of linear spatial filter models and their nonlinear extensions. However, for certain texture pairs the ease of discrimination changes when the role of figure and ground are reversed. This asymmetry poses a problem for both linear and nonlinear models. We have isolated a property of texture perception that can account for...

  17. Volumetric 3D display with multi-layered active screens for enhanced the depth perception (Conference Presentation)

    Science.gov (United States)

    Kim, Hak-Rin; Park, Min-Kyu; Choi, Jun-Chan; Park, Ji-Sub; Min, Sung-Wook

    2016-09-01

    Three-dimensional (3D) display technology has been studied actively because it can offer more realistic images compared to the conventional 2D display. Various psychological factors such as accommodation, binocular parallax, convergence and motion parallax are used to recognize a 3D image. For glass-type 3D displays, they use only the binocular disparity in 3D depth cues. However, this method cause visual fatigue and headaches due to accommodation conflict and distorted depth perception. Thus, the hologram and volumetric display are expected to be an ideal 3D display. Holographic displays can represent realistic images satisfying the entire factors of depth perception. But, it require tremendous amount of data and fast signal processing. The volumetric 3D displays can represent images using voxel which is a physical volume. However, it is required for large data to represent the depth information on voxel. In order to simply encode 3D information, the compact type of depth fused 3D (DFD) display, which can create polarization distributed depth map (PDDM) image having both 2D color image and depth image is introduced. In this paper, a new volumetric 3D display system is shown by using PDDM image controlled by polarization controller. In order to introduce PDDM image, polarization states of the light through spatial light modulator (SLM) was analyzed by Stokes parameter depending on the gray level. Based on the analysis, polarization controller is properly designed to convert PDDM image into sectioned depth images. After synchronizing PDDM images with active screens, we can realize reconstructed 3D image. Acknowledgment This work was supported by `The Cross-Ministry Giga KOREA Project' grant from the Ministry of Science, ICT and Future Planning, Korea

  18. Risk perception of heat waves and its spatial variation in Nanjing, China

    Science.gov (United States)

    Huang, Lei; Yang, Qianqi; Li, Jie; Chen, Jin; He, Ruoying; Zhang, Can; Chen, Kai; Dong, Steven Guanpeng; Liu, Yang

    2018-05-01

    The intensity, frequency, and duration of heat waves are expected to increase with climate change. In this study, we found a significant difference of public perceived effects of heat waves and trust in government among urban, suburban, and rural districts. Rural residents had a significant higher effect perception than urbanites and also showed stronger willingness to have medical insurance or regular physical examinations. Meanwhile, suburban residents had the lowest trust perception in government among these three districts, which may be due to suburban districts' unique social structure and complex social issues. Besides, we assessed the relationship between the factor effect and demographic variables. The results showed that urban respondents' effect perception was significantly related to heat wave experiences. Suburban respondents' effect perception was significantly related to age, income, and heat wave experiences. And rural respondents' effect perception was significantly related to income and chronic diseases. Based on our results, much more attention needs to be paid to rural districts. The government should strengthen infrastructure construction such as cooling centers, improve emergency response plans and mechanisms, and increase reserves of emergency supplies in rural districts. Also, targeted risk communication is of the equal importance to aid the policy-makers improving the relationship with the public and regaining the public's trust and support.

  19. Risk perception of heat waves and its spatial variation in Nanjing, China

    Science.gov (United States)

    Huang, Lei; Yang, Qianqi; Li, Jie; Chen, Jin; He, Ruoying; Zhang, Can; Chen, Kai; Dong, Steven Guanpeng; Liu, Yang

    2017-12-01

    The intensity, frequency, and duration of heat waves are expected to increase with climate change. In this study, we found a significant difference of public perceived effects of heat waves and trust in government among urban, suburban, and rural districts. Rural residents had a significant higher effect perception than urbanites and also showed stronger willingness to have medical insurance or regular physical examinations. Meanwhile, suburban residents had the lowest trust perception in government among these three districts, which may be due to suburban districts' unique social structure and complex social issues. Besides, we assessed the relationship between the factor effect and demographic variables. The results showed that urban respondents' effect perception was significantly related to heat wave experiences. Suburban respondents' effect perception was significantly related to age, income, and heat wave experiences. And rural respondents' effect perception was significantly related to income and chronic diseases. Based on our results, much more attention needs to be paid to rural districts. The government should strengthen infrastructure construction such as cooling centers, improve emergency response plans and mechanisms, and increase reserves of emergency supplies in rural districts. Also, targeted risk communication is of the equal importance to aid the policy-makers improving the relationship with the public and regaining the public's trust and support.

  20. The Multidimensional Spectrum of Imagination: Images, Dreams, Hallucinations, and Active, Imaginative Perception

    Directory of Open Access Journals (Sweden)

    Nigel J.T. Thomas

    2014-04-01

    Full Text Available A theory of the structure and cognitive function of the human imagination that attempts to do justice to traditional intuitions about its psychological centrality is developed, largely through a detailed critique of the theory propounded by Colin McGinn. Like McGinn, I eschew the highly deflationary views of imagination, common amongst analytical philosophers, that treat it either as a conceptually incoherent notion, or as psychologically trivial. However, McGinn fails to develop his alternative account satisfactorily because (following Reid, Wittgenstein and Sartre he draws an excessively sharp, qualitative distinction between imagination and perception, and because of his flawed, empirically ungrounded conception of hallucination. His arguments in defense of these views are rebutted in detail, and the traditional, passive, Cartesian view of visual perception, upon which several of them implicitly rely, is criticized in the light of findings from recent cognitive science and neuroscience. It is also argued that the apparent intuitiveness of the passive view of visual perception is a result of mere historical contingency. An understanding of perception (informed by modern visual science as an inherently active process enables us to unify our accounts of perception, mental imagery, dreaming, hallucination, creativity, and other aspects of imagination within a single coherent theoretical framework.

  1. Power Perceptions and Negotiations in a Cross-National Email Writing Activity

    Science.gov (United States)

    Liu, Yichun

    2011-01-01

    The present study investigates EFL students' perceptions of power differentials and their negotiation strategies when communicating with native English-speaking students via emails. The study involved 28 Taiwanese and American undergraduates who participated in a semester-long cross-national email writing activity. Findings show that students in…

  2. Qualitative Spatial Reasoning for Visual Grouping in Sketches

    National Research Council Canada - National Science Library

    Forbus, Kenneth D; Tomai, Emmett; Usher, Jeffrey

    2003-01-01

    We believe that qualitative spatial reasoning provides a bridge between perception and cognition, by using visual computations to construct structural descriptions that have functional significance...

  3. Toward understanding the active SETI debate: Insights from risk communication and perception

    Science.gov (United States)

    Korbitz, Adam

    2014-12-01

    Insights from the robust field of risk communication and perception have to date been almost totally absent from the policy debate regarding the relative risks and merits of Active SETI or Messaging to Extraterrestrial Intelligence (METI). For many years, the practice (or proposed practice) of Active SETI has generated a vigorous and sometimes heated policy debate within the scientific community. There have also been some negative reactions in the media toward the activities of those engaged in Active SETI. Risk communication is a scientific approach to communication regarding situations involving potentially sensitive or controversial situations in which there may be high public concern and low public trust. The discipline has found wide acceptance and utility in fields such as public health, industrial regulation and environmental protection. Insights from the scientific field of risk communication (such as omission bias, loss aversion, the availability heuristic, probability neglect, and the general human preference for voluntary over involuntary risks) may help those who have participated in either side of the debate over Active SETI to better understand why the debate has taken on this posture. Principles of risk communication and risk perception may also help those engaged in Active SETI to communicate more effectively with other scientists, the public, with the media, and with policy makers regarding their activities and to better understand and respond to concerns expressed regarding the activity.

  4. A comprehensive model of audiovisual perception: both percept and temporal dynamics.

    Directory of Open Access Journals (Sweden)

    Patricia Besson

    Full Text Available The sparse information captured by the sensory systems is used by the brain to apprehend the environment, for example, to spatially locate the source of audiovisual stimuli. This is an ill-posed inverse problem whose inherent uncertainty can be solved by jointly processing the information, as well as introducing constraints during this process, on the way this multisensory information is handled. This process and its result--the percept--depend on the contextual conditions perception takes place in. To date, perception has been investigated and modeled on the basis of either one of two of its dimensions: the percept or the temporal dynamics of the process. Here, we extend our previously proposed audiovisual perception model to predict both these dimensions to capture the phenomenon as a whole. Starting from a behavioral analysis, we use a data-driven approach to elicit a bayesian network which infers the different percepts and dynamics of the process. Context-specific independence analyses enable us to use the model's structure to directly explore how different contexts affect the way subjects handle the same available information. Hence, we establish that, while the percepts yielded by a unisensory stimulus or by the non-fusion of multisensory stimuli may be similar, they result from different processes, as shown by their differing temporal dynamics. Moreover, our model predicts the impact of bottom-up (stimulus driven factors as well as of top-down factors (induced by instruction manipulation on both the perception process and the percept itself.

  5. Physical activity perceptions and behaviors among young adults with congenital heart disease: A mixed-methods study.

    Science.gov (United States)

    McKillop, Adam; McCrindle, Brian W; Dimitropoulos, Gina; Kovacs, Adrienne H

    2018-03-01

    A physically active lifestyle can help maintain positive physical and psychosocial health outcomes among adults with congenital heart disease (CHD). This study explored the physical activity perceptions and behaviors among young adults with CHD. This was a cross-sectional, mixed-methods study that included objectively measured physical activity assessment (accelerometer), individual semistructured interviews, and psychosocial questionnaires. Fifteen participants (67% male; 21 ± 3 years old) with moderate (n = 10) or complex (n = 5) CHD were recruited from an outpatient adult CHD clinic. Participants accumulated 26 ± 16 minutes of moderate-to-vigorous physical activity per day, and reported a high quality of life, moderate self-efficacy for exercise, and low cardiac-focused anxiety. Qualitative data indicated that participants reported more positive perceptions toward activity if their family members encouraged physical activity participation, including siblings that engaged in physical activity alongside participants. Participants described parents as supportive rather than overprotective. Activity precautions were perceived by participants as being instructions from cardiologists rather than restrictions by parents. Participants described some physical limitations compared to peers, but managed challenges by either working within their limitations or choosing activities that met their expectations and/or in which they could fully participate. Participants often described childhood physical activity in the context of school, physical education, and organized sports. Whereas physical activity in childhood was viewed as recreational, the cardiac health-promoting aspects became more prominent in adulthood. Activities performed during one's employment were considered sufficient to meet physical activity recommendation levels, and participants reported limited time and/or energy to participate in activity outside of work. The influence of family

  6. 78 FR 58343 - Information Collection Activities: Visitor Perceptions of Climate Change in U.S. National Parks

    Science.gov (United States)

    2013-09-23

    ....NM0000] Information Collection Activities: Visitor Perceptions of Climate Change in U.S. National Parks... Information Collection 1024-NEW, Visitor Perceptions of Climate Change in U.S. National Parks in the subject line. FOR FURTHER INFORMATION CONTACT: Angie Richman, Communication Specialist, Climate Change Response...

  7. Spatial Hearing with Incongruent Visual or Auditory Room Cues

    DEFF Research Database (Denmark)

    Gil Carvajal, Juan Camilo; Cubick, Jens; Santurette, Sébastien

    2016-01-01

    In day-to-day life, humans usually perceive the location of sound sources as outside their heads. This externalized auditory spatial perception can be reproduced through headphones by recreating the sound pressure generated by the source at the listener’s eardrums. This requires the acoustical...... the recording and playback room did affect distance perception. Consequently, the external perception of virtual sounds depends on the degree of congruency between the acoustical features of the environment and the stimuli....

  8. Hippocampal activation during retrieval of spatial context from episodic and semantic memory.

    Science.gov (United States)

    Hoscheidt, Siobhan M; Nadel, Lynn; Payne, Jessica; Ryan, Lee

    2010-10-15

    The hippocampus, a region implicated in the processing of spatial information and episodic memory, is central to the debate concerning the relationship between episodic and semantic memory. Studies of medial temporal lobe amnesic patients provide evidence that the hippocampus is critical for the retrieval of episodic but not semantic memory. On the other hand, recent neuroimaging studies of intact individuals report hippocampal activation during retrieval of both autobiographical memories and semantic information that includes historical facts, famous faces, and categorical information, suggesting that episodic and semantic memory may engage the hippocampus during memory retrieval in similar ways. Few studies have matched episodic and semantic tasks for the degree to which they include spatial content, even though spatial content may be what drives hippocampal activation during semantic retrieval. To examine this issue, we conducted a functional magnetic resonance imaging (fMRI) study in which retrieval of spatial and nonspatial information was compared during an episodic and semantic recognition task. Results show that the hippocampus (1) participates preferentially in the retrieval of episodic memories; (2) is also engaged by retrieval of semantic memories, particularly those that include spatial information. These data suggest that sharp dissociations between episodic and semantic memory may be overly simplistic and that the hippocampus plays a role in the retrieval of spatial content whether drawn from a memory of one's own life experiences or real-world semantic knowledge. Published by Elsevier B.V.

  9. Spatial Thinking: Precept for Understanding Operational Environments

    Science.gov (United States)

    2016-06-10

    A Computer Movie Simulating Urban Growth in the Detroit Region,” 236. 29 U.S. National Research Council, Learning to Think Spatially: GIS as a... children and spatial language, the article focuses on the use of geospatial information systems (GIS) as a support mechanism for learning to think...Thinking, Cognition, Learning , Geospatial, Operating Environment, Space Perception 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18

  10. A spatial analysis of variations in health access: linking geography, socio-economic status and access perceptions

    Science.gov (United States)

    2011-01-01

    Background This paper analyses the relationship between public perceptions of access to general practitioners (GPs) surgeries and hospitals against health status, car ownership and geographic distance. In so doing it explores the different dimensions associated with facility access and accessibility. Methods Data on difficulties experienced in accessing health services, respondent health status and car ownership were collected through an attitudes survey. Road distances to the nearest service were calculated for each respondent using a GIS. Difficulty was related to geographic distance, health status and car ownership using logistic generalized linear models. A Geographically Weighted Regression (GWR) was used to explore the spatial non-stationarity in the results. Results Respondent long term illness, reported bad health and non-car ownership were found to be significant predictors of difficulty in accessing GPs and hospitals. Geographic distance was not a significant predictor of difficulty in accessing hospitals but was for GPs. GWR identified the spatial (local) variation in these global relationships indicating locations where the predictive strength of the independent variables was higher or lower than the global trend. The impacts of bad health and non-car ownership on the difficulties experienced in accessing health services varied spatially across the study area, whilst the impacts of geographic distance did not. Conclusions Difficulty in accessing different health facilities was found to be significantly related to health status and car ownership, whilst the impact of geographic distance depends on the service in question. GWR showed how these relationships were varied across the study area. This study demonstrates that the notion of access is a multi-dimensional concept, whose composition varies with location, according to the facility being considered and the health and socio-economic status of the individual concerned. PMID:21787394

  11. Magnetoencephalographic activity related to conscious perception is stable within individuals across years but not between individuals

    DEFF Research Database (Denmark)

    Sandberg, Kristian; Barnes, Gareth Robert; Rees, Geraint

    2014-01-01

    Studies indicate that conscious perception is related to changes in neural activity within a time window that varies between 130 and 320 msec after stimulus presentation, yet it is not known whether such neural correlates of conscious perception are stable across time. Here, we examined the gener...

  12. Commonalities between perception and cognition

    Directory of Open Access Journals (Sweden)

    Michela C. Tacca

    2011-11-01

    Full Text Available Perception and cognition are highly interrelated. Given the influence that these systems exert on one another, it is important to explain how perceptual representations and cognitive representations interact. In this paper, I analyze the similarities between visual perceptual representations and cognitive representations in terms of their structural properties and content. Specifically, I argue that the spatial structure underlying visual object representation displays systematicity—a property that is considered to be characteristic of propositional cognitive representations. To this end, I propose a logical characterization of visual feature binding as described by Treisman’s Feature Integration Theory and argue that systematicity is not only a property of language-like representations, but also of spatially organized visual representations. Furthermore, I argue that if systematicity is taken to be a criterion to distinguish between conceptual and nonconceptual representations, then visual representations, that display systematicity, might count as an early type of conceptual representations. Showing these analogies between visual perception and cognition is an important step towards understanding the interface between the two systems. The ideas here presented might also set the stage for new empirical studies that directly compare binding (and other relational operations in visual perception and higher cognition.

  13. Implementing a Public Bicycle Share Program: Impact on Perceptions and Support for Public Policies for Active Transportation.

    Science.gov (United States)

    Bélanger-Gravel, Ariane; Gauvin, Lise; Fuller, Daniel; Drouin, Louis

    2015-04-01

    Favorable public opinion and support for policies are essential to favor the sustainability of environmental interventions. This study examined public perceptions and support for active living policies associated with implementing a public bicycle share program (PBSP). Two cross-sectional population-based telephone surveys were conducted in 2009 and 2010 among 5011 adults in Montréal, Canada. Difference-in-differences analyses tested the impact of the PBSP on negative perceptions of the impact of the PBSP on the image of the city, road safety, ease of traveling, active transportation, health, and resistance to policies. People living closer to docking stations were less likely to have negative perceptions of the effect of the PBSP on the image of the city (OR = 0.5; 95% CI, 0.4-0.8) and to be resistant to policies (OR = 0.8; 95% CI, 0.6-1.0). The likelihood of perceiving negative effects on road safety increased across time (OR = 1.4; 95% CI, 1.2-1.8). Significant interactions were observed for perceptions of ease of traveling (OR = 0.5; 95% CI, 0.4-0.8), active transportation (OR = 0.6; 95% CI, 0.4-1.0), and health (OR = 0.6; 95% CI, 0.4-0.8): likelihood of negative perceptions decreased across time among people exposed. Findings indicate that negative perceptions were more likely to abate among those living closer to the PBSP.

  14. The Characteristics Of Malay House Spatial Layout Of Pekanbaru In Accordance With Islamic Values

    Science.gov (United States)

    Samra, Boby

    2017-12-01

    House is not only is a place to get rest and do activities bu also treated as a pride for the Malay community. The values contained in the spatial layout of the house have specific meaning to the owners. This makes the Malay house becomes the symbol of pride to uphold the “tuah” and dignity of the owner. This research is conducted using qualitative approach through management and data management available through several methods such as observation, interview, documentation and group discussion. This is expected to provide understanding of the perception of Islam dealing with the characteristics of the spatial layout of the Malay house of Pekanbaru.

  15. Spatial Representations in Local Field Potential Activity of Primate Anterior Intraparietal Cortex (AIP.

    Directory of Open Access Journals (Sweden)

    Sebastian J Lehmann

    Full Text Available The execution of reach-to-grasp movements in order to interact with our environment is an important subset of the human movement repertoire. To coordinate such goal-directed movements, information about the relative spatial position of target and effector (in this case the hand has to be continuously integrated and processed. Recently, we reported the existence of spatial representations in spiking-activity of the cortical fronto-parietal grasp network (Lehmann & Scherberger 2013, and in particular in the anterior intraparietal cortex (AIP. To further investigate the nature of these spatial representations, we explored in two rhesus monkeys (Macaca mulatta how different frequency bands of the local field potential (LFP in AIP are modulated by grip type, target position, and gaze position, during the planning and execution of reach-to-grasp movements. We systematically varied grasp type, spatial target, and gaze position and found that both spatial and grasp information were encoded in a variety of frequency bands (1-13Hz, 13-30Hz, 30-60Hz, and 60-100Hz, respectively. Whereas the representation of grasp type strongly increased towards and during movement execution, spatial information was represented throughout the task. Both spatial and grasp type representations could be readily decoded from all frequency bands. The fact that grasp type and spatial (reach information was found not only in spiking activity, but also in various LFP frequency bands of AIP, might significantly contribute to the development of LFP-based neural interfaces for the control of upper limb prostheses.

  16. A geo-spatial data management system for potentially active volcanoes—GEOWARN project

    Science.gov (United States)

    Gogu, Radu C.; Dietrich, Volker J.; Jenny, Bernhard; Schwandner, Florian M.; Hurni, Lorenz

    2006-02-01

    Integrated studies of active volcanic systems for the purpose of long-term monitoring and forecast and short-term eruption prediction require large numbers of data-sets from various disciplines. A modern database concept has been developed for managing and analyzing multi-disciplinary volcanological data-sets. The GEOWARN project (choosing the "Kos-Yali-Nisyros-Tilos volcanic field, Greece" and the "Campi Flegrei, Italy" as test sites) is oriented toward potentially active volcanoes situated in regions of high geodynamic unrest. This article describes the volcanological database of the spatial and temporal data acquired within the GEOWARN project. As a first step, a spatial database embedded in a Geographic Information System (GIS) environment was created. Digital data of different spatial resolution, and time-series data collected at different intervals or periods, were unified in a common, four-dimensional representation of space and time. The database scheme comprises various information layers containing geographic data (e.g. seafloor and land digital elevation model, satellite imagery, anthropogenic structures, land-use), geophysical data (e.g. from active and passive seismicity, gravity, tomography, SAR interferometry, thermal imagery, differential GPS), geological data (e.g. lithology, structural geology, oceanography), and geochemical data (e.g. from hydrothermal fluid chemistry and diffuse degassing features). As a second step based on the presented database, spatial data analysis has been performed using custom-programmed interfaces that execute query scripts resulting in a graphical visualization of data. These query tools were designed and compiled following scenarios of known "behavior" patterns of dormant volcanoes and first candidate signs of potential unrest. The spatial database and query approach is intended to facilitate scientific research on volcanic processes and phenomena, and volcanic surveillance.

  17. Do Perceptions of Competence Mediate The Relationship Between Fundamental Motor Skill Proficiency and Physical Activity Levels of Children in Kindergarten?

    Science.gov (United States)

    Crane, Jeff R; Naylor, Patti J; Cook, Ryan; Temple, Viviene A

    2015-07-01

    Perceptions of competence mediate the relationship between motor skill proficiency and physical activity among older children and adolescents. This study examined kindergarten children's perceptions of physical competence as a mediator of the relationship between motor skill proficiency as a predictor variable and physical activity levels as the outcome variable; and also with physical activity as a predictor and motor skill proficiency as the outcome. Participants were 116 children (mean age = 5 years 7 months, 58% boys) from 10 schools. Motor skills were measured using the Test of Gross Motor Development-2 and physical activity was monitored through accelerometry. Perceptions of physical competence were measured using The Pictorial Scale of Perceived Competence and Social Acceptance for Young Children, and the relationships between these variables were examined using a model of mediation. The direct path between object control skills and moderate-vigorous physical activity (MVPA) was significant and object control skills predicted perceived physical competence. However, perceived competence did not mediate the relationship between object control skills and MVPA. The significant relationship between motor proficiency and perceptions of competence did not in turn influence kindergarten children's participation in physical activity. These findings support concepts of developmental differences in the structure of the self-perception system.

  18. Malawian parents' perceptions of physical activity and child development: a qualitative study.

    Science.gov (United States)

    Pulakka, A; Ashorn, P; Gondwe, A; Phiri, N; Ashorn, U

    2015-11-01

    In scientific studies, physical activity is measured by the amount of bodily movement, but lay perceptions of physical activity might be different. Parental influence is important for the development of children's physical activity behaviour, and parental perceptions of facilitators of physical activity are context specific. We aimed to investigate how parents of young Malawian children conceptualize physical activity in childhood, situate it in child development and understand its facilitators. We used convenience sampling to identify parents of young children from different socio-economic backgrounds and age groups in semi-rural area of Malawi. We conducted in-depth interviews with 16 parents, a focus group discussion with six parents and key informant interviews with two nurses in Malawi. Six of the participants were fathers. We analysed the data with conventional qualitative content analysis by inductive approach. The parents emphasized practical skills, education and proper behaviour as goals for their children. They viewed activity as encompassing both mental and physical qualities and they perceived it as a positive attribute of children. The parents discussed skills acquisition, social competence, health and bodily movement as signs for being active. As facilitators of physical activity the parents mentioned balanced diet, good health and stimulation. The main concerns of the parents in regard to facilitators of physical activity and good child development were the availability of food and the child being healthy. Malawian parents' concept of children's physical activity is more comprehensive than scientific definition and includes aspects of both physical and mental activity. © 2014 John Wiley & Sons Ltd.

  19. Long-term heavy ketamine use is associated with spatial memory impairment and altered hippocampal activation

    Directory of Open Access Journals (Sweden)

    Celia J A Morgan

    2014-12-01

    Full Text Available Ketamine, a non-competitive N-methyl-D-aspartate receptor antagonist, is rising in popularity as a drug of abuse. Preliminary evidence suggests that chronic, heavy ketamine use may have profound effects on spatial memory but the mechanism of these deficits is as yet unclear. This study aimed to examine the neural mechanism by which heavy ketamine use impairs spatial memory processing. In a sample of 11 frequent ketamine users and 15 polydrug controls, matched for IQ, age and years in education. We used fMRI utilising an ROI approach to examine the neural activity of three regions known to support successful navigation; the hippocampus, parahippocampal gyrus and the caudate nucleus during a virtual reality task of spatial memory. Frequent ketamine users displayed spatial memory deficits, accompanied by and related to, reduced activation in both the right hippocampus and left parahippocampal gyrus during navigation from memory, and in the left caudate during memory updating, compared to controls. Ketamine users also exhibited schizotypal and dissociative symptoms that were related to hippocampal activation. Impairments in spatial memory observed in ketamine users are related to changes in medial temporal lobe activation. Disrupted medial temporal lobe function may be a consequence of chronic ketamine abuse and may relate to schizophrenia-like symptomatology observed in ketamine users.

  20. Collective Activity of Many Bistable Assemblies Reproduces Characteristic Dynamics of Multistable Perception.

    Science.gov (United States)

    Cao, Robin; Pastukhov, Alexander; Mattia, Maurizio; Braun, Jochen

    2016-06-29

    The timing of perceptual decisions depends on both deterministic and stochastic factors, as the gradual accumulation of sensory evidence (deterministic) is contaminated by sensory and/or internal noise (stochastic). When human observers view multistable visual displays, successive episodes of stochastic accumulation culminate in repeated reversals of visual appearance. Treating reversal timing as a "first-passage time" problem, we ask how the observed timing densities constrain the underlying stochastic accumulation. Importantly, mean reversal times (i.e., deterministic factors) differ enormously between displays/observers/stimulation levels, whereas the variance and skewness of reversal times (i.e., stochastic factors) keep characteristic proportions of the mean. What sort of stochastic process could reproduce this highly consistent "scaling property?" Here we show that the collective activity of a finite population of bistable units (i.e., a generalized Ehrenfest process) quantitatively reproduces all aspects of the scaling property of multistable phenomena, in contrast to other processes under consideration (Poisson, Wiener, or Ornstein-Uhlenbeck process). The postulated units express the spontaneous dynamics of attractor assemblies transitioning between distinct activity states. Plausible candidates are cortical columns, or clusters of columns, as they are preferentially connected and spontaneously explore a restricted repertoire of activity states. Our findings suggests that perceptual representations are granular, probabilistic, and operate far from equilibrium, thereby offering a suitable substrate for statistical inference. Spontaneous reversals of high-level perception, so-called multistable perception, conform to highly consistent and characteristic statistics, constraining plausible neural representations. We show that the observed perceptual dynamics would be reproduced quantitatively by a finite population of distinct neural assemblies, each with

  1. The change in spatial distribution of upper trapezius muscle activity is correlated to contraction duration.

    Science.gov (United States)

    Farina, Dario; Leclerc, Frédéric; Arendt-Nielsen, Lars; Buttelli, Olivier; Madeleine, Pascal

    2008-02-01

    The aim of the study was to confirm the hypothesis that the longer a contraction is sustained, the larger are the changes in the spatial distribution of muscle activity. For this purpose, surface electromyographic (EMG) signals were recorded with a 13 x 5 grid of electrodes from the upper trapezius muscle of 11 healthy male subjects during static contractions with shoulders 90 degrees abducted until endurance. The entropy (degree of uniformity) and center of gravity of the EMG root mean square map were computed to assess spatial inhomogeneity in muscle activation and changes over time in EMG amplitude spatial distribution. At the endurance time, entropy decreased (mean+/-SD, percent change 2.0+/-1.6%; Pgrid) root mean square was positively correlated with the shift in the center of gravity (R(2)=0.51, P<0.05). Moreover, the shift in the center of gravity was negatively correlated to both initial and final (at the endurance) entropy (R(2)=0.54 and R(2)=0.56, respectively; P<0.01 in both cases), indicating that subjects with less uniform root mean square maps had larger shift of the center of gravity over time. The spatial changes in root mean square EMG were likely due to spatially-dependent changes in motor unit activation during the sustained contraction. It was concluded that the changes in spatial muscle activity distribution play a role in the ability to maintain a static contraction.

  2. Theories of Person Perception Predict Patterns of Neural Activity During Mentalizing.

    Science.gov (United States)

    Thornton, Mark A; Mitchell, Jason P

    2017-08-22

    Social life requires making inferences about other people. What information do perceivers spontaneously draw upon to make such inferences? Here, we test 4 major theories of person perception, and 1 synthetic theory that combines their features, to determine whether the dimensions of such theories can serve as bases for describing patterns of neural activity during mentalizing. While undergoing functional magnetic resonance imaging, participants made social judgments about well-known public figures. Patterns of brain activity were then predicted using feature encoding models that represented target people's positions on theoretical dimensions such as warmth and competence. All 5 theories of person perception proved highly accurate at reconstructing activity patterns, indicating that each could describe the informational basis of mentalizing. Cross-validation indicated that the theories robustly generalized across both targets and participants. The synthetic theory consistently attained the best performance-approximately two-thirds of noise ceiling accuracy--indicating that, in combination, the theories considered here can account for much of the neural representation of other people. Moreover, encoding models trained on the present data could reconstruct patterns of activity associated with mental state representations in independent data, suggesting the use of a common neural code to represent others' traits and states. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. A longitudinal examination of the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls.

    Science.gov (United States)

    Knowles, Ann-Marie; Niven, Ailsa G; Fawkner, Samantha G; Henretty, Joan M

    2009-06-01

    This longitudinal study investigated the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls (N=150; mean age=12.79+/-0.31). Physical characteristics were measured and participants completed the Physical Activity Questionnaire for Children, the Children and Youth Physical Self-Perception Profile and the Pubertal Development Scale on two occasions 12 months apart. The results demonstrated a decrease in overall physical activity levels over 12 months which was not influenced by maturational status or physical characteristics. Additional analysis indicated that physical self-perceptions partially accounted for the explained variance in physical activity change, with physical condition being an important individual predictor of physical activity. Further analysis indicated that body mass was an important individual predictor of changes in perceptions of body attractiveness and physical self-worth. At this age maturation has a limited influence on the physical activity behaviours of early adolescent girls and although the variance in physical activity was partly accounted for by physical self-perceptions, this was a relatively small contribution and other factors related to this drop in physical activity need to be considered longitudinally.

  4. Parametric time-frequency domain spatial audio

    CERN Document Server

    Delikaris-Manias, Symeon; Politis, Archontis

    2018-01-01

    This book provides readers with the principles and best practices in spatial audio signal processing. It describes how sound fields and their perceptual attributes are captured and analyzed within the time-frequency domain, how essential representation parameters are coded, and how such signals are efficiently reproduced for practical applications. The book is split into four parts starting with an overview of the fundamentals. It then goes on to explain the reproduction of spatial sound before offering an examination of signal-dependent spatial filtering. The book finishes with coverage of both current and future applications and the direction that spatial audio research is heading in. Parametric Time-frequency Domain Spatial Audio focuses on applications in entertainment audio, including music, home cinema, and gaming--covering the capturing and reproduction of spatial sound as well as its generation, transduction, representation, transmission, and perception. This book will teach readers the tools needed...

  5. Physical Activity and Health Perception in Aging: Do Body Mass and Satisfaction Matter? A Three-Path Mediated Link.

    Science.gov (United States)

    Condello, Giancarlo; Capranica, Laura; Stager, Joel; Forte, Roberta; Falbo, Simone; Di Baldassarre, Angela; Segura-Garcia, Cristina; Pesce, Caterina

    2016-01-01

    Although ageing people could benefit from healthy diet and physical activity to maintain health and quality of life, further understandings of the diet- and physical activity-related mechanisms that may cause changes in health and quality of life perception are necessary. The purpose of the study was to investigate the effect of eating attitudes, body mass and image satisfaction, and exercise dependence in the relationship between physical activity and health and quality of life perception in older individuals. Hundred and seventy-nine late middle-aged, (55-64 yrs), young-old (65-74 yrs), and old (75-84 yrs) senior athletes (n = 56), physically active (n = 58) or sedentary adults (n = 65) were submitted to anthropometric evaluations (body mass, height) and self-reported questionnaires: Body Image Dimensional Assessment, Exercise Dependence Scale, Eating Attitude Test, and Short Form Health Survey (Physical Component Summary [PCS] and Mental Component Summary [MCS] of and health and quality of life perception). Senior athletes, physically active, and sedentary participants subgroups differed (Psatisfaction. Findings confirm the relevant role of physically active life habits for older individuals to perceive good physical and mental health. The novelty of the three-path mediated link between physical activity level and mental health perception suggests that the beneficial effect of a physically active lifestyle on weight control can positively impinge on the cognitive-emotional dimension of mental health by ensuring the maintenance, also at older age, of a satisfactory body image.

  6. Effects of a physical activity programme on body perception and composition in overweight adolescents

    Directory of Open Access Journals (Sweden)

    Onofre Ricardo Contreras-Jordán

    2017-03-01

    Full Text Available Background The purpose of this study was to examine the effectiveness of a six months' physical activity programme for overweight and obese adolescents, in order to improve the perception of their own body image and composition between two groups of adolescents, and to check possible gender differences. Aims The aim is to improve the body perception and composition in overweight adolescents with a physical activity programme. Methods It was a quasi-experimental design, with a control group and intervention group. Measures of pre-test and post-test were taken. A total of 38 adolescents that belong to the first cycle of Compulsory Secondary aged 12–15, with a body mass index (BMI higher than the 85th percentile according to the WHO (World Health Organization, participated in the intervention. The anthropometric variables, height, weight, BMI, body fat percentage, and the circumference of the waist, hip, arm and medial calf, were measured pre- and post-treatment. The body image perception was measured using the Gardner test. The experimental group participated in the physical activity programme for a six months period. The physical activity intervention consisted of three sessions of 90 minutes each week in a sports centre. The structure of the sessions consisted of a warm-up (5–10 minutes, a main activity (60–70 minutes, combineding strength and cardiovascular training and a cool-down (7–10 minutes. Results After physical activity intervention the results showed significant improvements in the experimental group compared to the control group in the circumference of the waist, the hip, the arm, the medial calf (p<0.01 and as well as the fat percentage, the percentage of muscle mass (p<0.05. The results showed how the body image distortion presented a significant and negative correlation with the circumference of the waist (p<0.001, of the hips (p<0.01, and of the arm (p<0.001, differences were observed between gender. Conclusion Our study

  7. Cellular activation of hypothalamic hypocretin/orexin neurons facilitates short-term spatial memory in mice.

    Science.gov (United States)

    Aitta-Aho, Teemu; Pappa, Elpiniki; Burdakov, Denis; Apergis-Schoute, John

    2016-12-01

    The hypothalamic hypocretin/orexin (HO) system holds a central role in the regulation of several physiological functions critical for food-seeking behavior including mnemonic processes for effective foraging behavior. It is unclear however whether physiological increases in HO neuronal activity can support such processes. Using a designer rM3Ds receptor activation approach increasing HO neuronal activity resulted in improved short-term memory for novel locations. When tested on a non-spatial novelty object recognition task no significant difference was detected between groups indicating that hypothalamic HO neuronal activation can selectively facilitate short-term spatial memory for potentially supporting memory for locations during active exploration. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The Role of Schools in Children's Physical Activity Participation: Staff Perceptions

    Science.gov (United States)

    Huberty, J.; Dinkel, D.; Coleman, J.; Beighle, A.; Apenteng, B.

    2012-01-01

    The school setting provides a promising environment to increase children's physical activity (PA), however, staff often impact the success of PA within schools. The purpose of this article was to describe the knowledge of elementary school staff related to PA and their perception of the importance of the school environment being conducive to PA…

  9. Meet Seymour Safely. Seymour Safely Activity Book I.

    Science.gov (United States)

    American Optometric Association, St. Louis, MO.

    This activity book teaches elementary school students about good vision and eye safety through a combination of puppet plays, stories, songs, and games. Nine games are provided to help children develop vision skills including visual memory, visual perception, directionality, spatial orientation, and visual-motor responses. Master Plans for making…

  10. Auditory perception and the control of spatially coordinated action of deaf and hearing children.

    Science.gov (United States)

    Savelsbergh, G J; Netelenbos, J B; Whiting, H T

    1991-03-01

    From birth onwards, auditory stimulation directs and intensifies visual orientation behaviour. In deaf children, by definition, auditory perception cannot take place and cannot, therefore, make a contribution to visual orientation to objects approaching from outside the initial field of view. In experiment 1, a difference in catching ability is demonstrated between deaf and hearing children (10-13 years of age) when the ball approached from the periphery or from outside the field of view. No differences in catching ability between the two groups occurred when the ball approached from within the field of view. A second experiment was conducted in order to determine if differences in catching ability between deaf and hearing children could be attributed to execution of slow orientating movements and/or slow reaction time as a result of the auditory loss. The deaf children showed slower reaction times. No differences were found in movement times between deaf and hearing children. Overall, the findings suggest that a lack of auditory stimulation during development can lead to deficiencies in the coordination of actions such as catching which are both spatially and temporally constrained.

  11. Older Adults' Perceptions of Physical Activity and Cognitive Health: Implications for Health Communication

    Science.gov (United States)

    Price, Anna E.; Corwin, Sara J.; Friedman, Daniela B.; Laditka, Sarah B.; Colabianchi, Natalie; Montgomery, Kara M.

    2011-01-01

    Messages promoting physical activity (PA) to maintain cognitive health (CH) may increase PA and enhance CH among older persons. This study examined older adults' perceptions of PA and CH. We conducted 10 focus groups with irregularly active older Black and White women and men (N = 55), ages 65 to 74 in South Carolina. Constant comparison methods…

  12. Self-perception and dissatisfaction with weight does not depend on the frequency of physical activity

    Directory of Open Access Journals (Sweden)

    Araújo Denise Sardinha Mendes Soares de

    2003-01-01

    Full Text Available OBJECTIVE: To evaluate the level of satisfaction with body weight and the self-perception of the weight/height ratio and to verify the influence of the frequency of present and past physical activity on these variables. METHODS: Using questionnaires or interviews, we obtained height data, reported and desired weight, self-perception of the weight/height ratio, and the frequency of current physical activity in 844 adults (489 women. Of these, evaluated the frequency of physical activity during high school of 193 individuals,and we measured their height and weight. RESULTS: Less than 2/3 of the individuals had body mass index between 20 and 24.9 kg/m2. A tendency existed to overestimate height by less than 1 cm and to underestimate weight by less than 1kg. Desired weight was less than that reported (p<0.001, and only 20% were satisfied with their current weight. Only 42% of men and 25% of women exercised regularly. No association was found between the frequency of physical activity and the variables height, weight, and body mass index, and the level of satisfaction with current weight. CONCLUSION: Height and weight reported seem to be valid for epidemological studies, and great dissatisfaction with body weight and a distorted self-perception of height/weight ratio exists, especially in women, regardless of the frequency of physical activity.

  13. Fear of falling and self-perception of health in older participants and non-participants of physical activity programs

    Directory of Open Access Journals (Sweden)

    Carolina Kruleske da Silva

    2013-12-01

    Full Text Available Fear of falling, self-perception of health, and participation in physical activity programs have been associated with several variables related to health and performance in older adults. The purpose of this study was to evaluate self-perception of health and fear of falling in older adult participants and non-participants of physical activity programs, and to verify the relationship between these variables. A total of 40 healthy but sedentary older adults, and 45 physically active older adults were assessed through the Falls Efficacy Scale International-Brazil (FES-I and a questionnaire that measured their self-perception of health. The older adults that did not participate in regular physical activity programs presented higher scores of fear of falling, which, in turn, is associated with an increase of risk for falls. Moreover, older adults, participants in regular physical activity programs exhibited a more positive health perception than did the non-participants. Also, non-participants of physical activity programs perceived their health status as being poor or very poor as well as expressing great concern about falling compared to those who considered their health as excellent, good or regular. The results of this study have important implications for making clinical decisions in prevention or rehabilitation of older people, and they justify recommendations to the public health system.

  14. Modeling human perception of orientation in altered gravity

    Science.gov (United States)

    Clark, Torin K.; Newman, Michael C.; Oman, Charles M.; Merfeld, Daniel M.; Young, Laurence R.

    2015-01-01

    Altered gravity environments, such as those experienced by astronauts, impact spatial orientation perception, and can lead to spatial disorientation and sensorimotor impairment. To more fully understand and quantify the impact of altered gravity on orientation perception, several mathematical models have been proposed. The utricular shear, tangent, and the idiotropic vector models aim to predict static perception of tilt in hyper-gravity. Predictions from these prior models are compared to the available data, but are found to systematically err from the perceptions experimentally observed. Alternatively, we propose a modified utricular shear model for static tilt perception in hyper-gravity. Previous dynamic models of vestibular function and orientation perception are limited to 1 G. Specifically, they fail to predict the characteristic overestimation of roll tilt observed in hyper-gravity environments. To address this, we have proposed a modification to a previous observer-type canal-otolith interaction model based upon the hypothesis that the central nervous system (CNS) treats otolith stimulation in the utricular plane differently than stimulation out of the utricular plane. Here we evaluate our modified utricular shear and modified observer models in four altered gravity motion paradigms: (a) static roll tilt in hyper-gravity, (b) static pitch tilt in hyper-gravity, (c) static roll tilt in hypo-gravity, and (d) static pitch tilt in hypo-gravity. The modified models match available data in each of the conditions considered. Our static modified utricular shear model and dynamic modified observer model may be used to help quantitatively predict astronaut perception of orientation in altered gravity environments. PMID:25999822

  15. Modeling Human Perception of Orientation in Altered Gravity

    Directory of Open Access Journals (Sweden)

    Torin K. Clark

    2015-05-01

    Full Text Available Altered gravity environments, such as those experienced by astronauts, impact spatial orientation perception and can lead to spatial disorientation and sensorimotor impairment. To more fully understand and quantify the impact of altered gravity on orientation perception, several mathematical models have been proposed. The utricular shear, tangent, and the idiotropic vector models aim to predict static perception of tilt in hyper-gravity. Predictions from these prior models are compared to the available data, but are found to systematically err from the perceptions experimentally observed. Alternatively, we propose a modified utricular shear model for static tilt perception in hyper-gravity. Previous dynamic models of vestibular function and orientation perception are limited to 1 G. Specifically, they fail to predict the characteristic overestimation of roll tilt observed in hyper-gravity environments. To address this, we have proposed a modification to a previous observer-type canal otolith interaction model based upon the hypothesis that the central nervous system treats otolith stimulation in the utricular plane differently than stimulation out of the utricular plane. Here we evaluate our modified utricular shear and modified observer models in four altered gravity motion paradigms: a static roll tilt in hyper-gravity, b static pitch tilt in hyper-gravity, c static roll tilt in hypo-gravity, and d static pitch tilt in hypo-gravity. The modified models match available data in each of the conditions considered. Our static modified utricular shear model and dynamic modified observer model may be used to help quantitatively predict astronaut perception of orientation in altered gravity environments.

  16. Associations between physical activity parenting practices and adolescent girls' self-perceptions and physical activity intentions.

    Science.gov (United States)

    Sebire, Simon J; Haase, Anne M; Montgomery, Alan A; McNeill, Jade; Jago, Russ

    2014-05-01

    The current study investigated cross-sectional associations between maternal and paternal logistic and modeling physical activity support and the self-efficacy, self-esteem, and physical activity intentions of 11- to 12-year-old girls. 210 girls reported perceptions of maternal and paternal logistic and modeling support and their self-efficacy, self-esteem and intention to be physically active. Data were analyzed using multivariable regression models. Maternal logistic support was positively associated with participants' self-esteem, physical activity self-efficacy, and intention to be active. Maternal modeling was positively associated with self-efficacy. Paternal modeling was positively associated with self-esteem and self-efficacy but there was no evidence that paternal logistic support was associated with the psychosocial variables. Activity-related parenting practices were associated with psychosocial correlates of physical activity among adolescent girls. Logistic support from mothers, rather than modeling support or paternal support may be a particularly important target when designing interventions aimed at preventing the age-related decline in physical activity among girls.

  17. A jacket for assisting sensorimotor-related impairments and spatial perception

    International Nuclear Information System (INIS)

    Blumenstein, Tobias; Turova, Varvara; Alves-Pinto, Ana; Lampe, Renée

    2017-01-01

    A sensorimotor jacket, which is able to measure distances to nearby objects with ultrasonic sensors and to transmit information about distances via vibrating transducers, has been designed with the aim of improving the spatial awareness of patients with cerebral palsy and to facilitate spatial orientation for blind people. The efficiency was tested for patients diagnosed with cerebral palsy, blind participants and healthy people. A positive impact of the sensorimotor jacket on the performance in a spatial task has been established both in patients with cerebral palsy and blind participants. Moreover, for patients with cerebral palsy, the training effect was visible after only three training exercises. (paper)

  18. Strengthening physical self-perceptions through exercise.

    Science.gov (United States)

    Caruso, C M; Gill, D L

    1992-12-01

    Two studies examined the effects of physical activity/exercise on physical self-perceptions, self-efficacy, body satisfaction, fitness and relationships among these variables. In study 1, 34 female undergraduates participated in a 10-week exercise/activity program. Participants were selected from existing classes forming a weight training, aerobic exercise and activity control group. Results revealed changes in physical self-perceptions, strength, and body composition over the 10-weeks. Improvements in physical self-perceptions and fitness occurred independent of exercise/activity group. Groups differed in the perceived importance attached to physical self-perceptions. Correlations among the measures revealed relationships among physical self-perceptions, body satisfaction, global self-esteem, and fitness. In study 2, we hypothesized that weight training would have a greater effect on physical self-perceptions and body image perceptions than physical education activity classes. Thirty-seven males and 28 females were selected from existing classes forming a weight training and activity group. Results revealed no significant changes in physical self-perceptions, body image, or global self-esteem over the 10-week program, while strength and physical self-efficacy improved. Correlations among measures from both studies offer preliminary support for Sonstroem and Morgan's model for the examination of self-esteem in exercise settings.

  19. Rapid encoding and perception of novel odors in the rat.

    Directory of Open Access Journals (Sweden)

    Daniel W Wesson

    2008-04-01

    Full Text Available To gain insight into which parameters of neural activity are important in shaping the perception of odors, we combined a behavioral measure of odor perception with optical imaging of odor representations at the level of receptor neuron input to the rat olfactory bulb. Instead of the typical test of an animal's ability to discriminate two familiar odorants by exhibiting an operant response, we used a spontaneously expressed response to a novel odorant-exploratory sniffing-as a measure of odor perception. This assay allowed us to measure the speed with which rats perform spontaneous odor discriminations. With this paradigm, rats discriminated and began responding to a novel odorant in as little as 140 ms. This time is comparable to that measured in earlier studies using operant behavioral readouts after extensive training. In a subset of these trials, we simultaneously imaged receptor neuron input to the dorsal olfactory bulb with near-millisecond temporal resolution as the animal sampled and then responded to the novel odorant. The imaging data revealed that the bulk of the discrimination time can be attributed to the peripheral events underlying odorant detection: receptor input arrives at the olfactory bulb 100-150 ms after inhalation begins, leaving only 50-100 ms for central processing and response initiation. In most trials, odor discrimination had occurred even before the initial barrage of receptor neuron firing had ceased and before spatial maps of activity across glomeruli had fully developed. These results suggest a coding strategy in which the earliest-activated glomeruli play a major role in the initial perception of odor quality, and place constraints on coding and processing schemes based on simple changes in spike rate.

  20. African American and White women׳s perceptions of weight gain, physical activity, and nutrition during pregnancy.

    Science.gov (United States)

    Whitaker, Kara M; Wilcox, Sara; Liu, Jihong; Blair, Steven N; Pate, Russell R

    2016-03-01

    To describe African American and White women's perceptions of weight gain, physical activity, and nutrition during pregnancy and to explore differences in perceptions by race. Qualitative interview study. Two Ob/Gyn clinics in South Carolina, USA. Thirty pregnant women (15 African American, 15 White) between 20 and 30 weeks gestation, equally represented across pre-pregnancy BMI categories (10 normal weight, 10 overweight, and 10 obese). White women more frequently described intentions to meet weight gain, physical activity, and dietary guidelines in pregnancy than African American women. African American women were more concerned with inadequate weight gain while White women more commonly expressed concerns about excessive weight gain. More White women discussed the importance of physical activity for weight management. Regardless of race, few women described risks of excessive weight gain or benefits of physical activity as it relates to the baby's health. The primary cited barrier of healthy eating was the high cost of fresh produce. Several knowledge gaps as well as race differences were identified in women's perceptions and intentions toward weight gain, physical activity, and nutrition during pregnancy. Future interventions should seek to educate women about common misperceptions. It may be necessary to culturally tailor gestational weight gain interventions to optimise health outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Educational Administrators’ Technological Leadership Efficacy and Perceptions towards Implementation Levels of Teaching and Learning Activities

    Directory of Open Access Journals (Sweden)

    Fatih ULUKAYA

    2017-12-01

    Full Text Available The aim of this study is to identify the educational administrators’ technological leadership efficacy (TLE and perceptions towards implementation levels of teaching and learning activities (ITLA, and then to present the contribution of the TLE as a predictor of the ITLA. We collected data from 112 educational administrators who are working in Tokat. According to the results of this study, educational administrators’ TLE level was “adequate” for only Digital age learning culture, for the other factors and the total of the TLE levels were “intermediate” level. According to ITLA results, all the sub-factors and total of the scale were “strongly agree” level. The technological leadership efficacy and perceptions towards implementation levels of teaching and learning activities differ according to educational administrators’ age, school type and working in town/city. There is a positive, medium level and significant correlation between educational administrators’ total scores of the TLE and ITLA. A simple linear regression was calculated to predict administrators’ perceptions towards implementation levels of teaching and learning activities based on their technological leadership efficacy, and TLE explains only 29% of the variation in ITLA.

  2. Fusing a Reversed and Informal Learning Scheme and Space: Student Perceptions of Active Learning in Physical Chemistry

    Science.gov (United States)

    Donnelly, Julie; Hernández, Florencio E.

    2018-01-01

    Physical chemistry students often have negative perceptions and low expectations for success in physical chemistry, attitudes that likely affect their performance in the course. Despite the results of several studies indicating increased positive perception of physical chemistry when active learning strategies are used, a recent survey of faculty…

  3. Speech perception in autism spectrum disorder: An activation likelihood estimation meta-analysis.

    Science.gov (United States)

    Tryfon, Ana; Foster, Nicholas E V; Sharda, Megha; Hyde, Krista L

    2018-02-15

    Autism spectrum disorder (ASD) is often characterized by atypical language profiles and auditory and speech processing. These can contribute to aberrant language and social communication skills in ASD. The study of the neural basis of speech perception in ASD can serve as a potential neurobiological marker of ASD early on, but mixed results across studies renders it difficult to find a reliable neural characterization of speech processing in ASD. To this aim, the present study examined the functional neural basis of speech perception in ASD versus typical development (TD) using an activation likelihood estimation (ALE) meta-analysis of 18 qualifying studies. The present study included separate analyses for TD and ASD, which allowed us to examine patterns of within-group brain activation as well as both common and distinct patterns of brain activation across the ASD and TD groups. Overall, ASD and TD showed mostly common brain activation of speech processing in bilateral superior temporal gyrus (STG) and left inferior frontal gyrus (IFG). However, the results revealed trends for some distinct activation in the TD group showing additional activation in higher-order brain areas including left superior frontal gyrus (SFG), left medial frontal gyrus (MFG), and right IFG. These results provide a more reliable neural characterization of speech processing in ASD relative to previous single neuroimaging studies and motivate future work to investigate how these brain signatures relate to behavioral measures of speech processing in ASD. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Vicarious motor activation during action perception: beyond correlational evidence

    Directory of Open Access Journals (Sweden)

    Alessio eAvenanti

    2013-05-01

    Full Text Available Neurophysiological and imaging studies have shown that seeing the actions of other individuals brings about the vicarious activation of motor regions involved in performing the same actions. While this suggests a simulative mechanism mediating the perception of others’ actions, one cannot use such evidence to make inferences about the functional significance of vicarious activations. Indeed, a central aim in social neuroscience is to comprehend how vicarious activations allow the understanding of other people’s behavior, and this requires to use stimulation or lesion methods to establish causal links from brain activity to cognitive functions. In the present work we review studies investigating the effects of transient manipulations of brain activity or stable lesions in the motor system on individuals’ ability to perceive and understand the actions of others. We conclude there is now compelling evidence that neural activity in the motor system is critical for such cognitive ability. More research using causal methods, however, is needed in order to disclose the limits and the conditions under which vicarious activations are required to perceive and understand actions of others as well as their emotions and somatic feelings.

  5. School Administrators' Perceptions of Factors that Influence Children's Active Travel to School

    Science.gov (United States)

    Price, Anna E.; Pluto, Delores M.; Ogoussan, Olga; Banda, Jorge A.

    2011-01-01

    Background: Increasing children's active travel to school may be 1 strategy for addressing the growing prevalence of obesity among school age children. Using the School Travel Survey, we examined South Carolina school district leaders' perceptions of factors that influence elementary and middle school students walking to school. Methods: Frequency…

  6. METHOD FOR DETERMINING THE SPATIAL COORDINATES IN THE ACTIVE STEREOSCOPIC SYSTEM

    Directory of Open Access Journals (Sweden)

    Valery V. Korotaev

    2014-11-01

    Full Text Available The paper deals with the structural scheme of active stereoscopic system and algorithm of its operation, providing the fast calculation of the spatial coordinates. The system includes two identical cameras, forming a stereo pair, and a laser scanner, which provides vertical scanning of the space before the system by the laser beam. A separate synchronizer provides synchronous operation of the two cameras. The developed algorithm of the system operation is implemented in MATLAB. In the proposed algorithm, the influence of background light is eliminated by interframe processing. The algorithm is based on precomputation of coordinates for epipolar lines and corresponding points in stereoscopic image. These data are used to quick calculation of the three-dimensional coordinates of points that form the three-dimensional images of objects. Experiment description on a physical model is given. Experimental results confirm the efficiency of the proposed active stereoscopic system and its operation algorithm. The proposed scheme of active stereoscopic system and calculating method for the spatial coordinates can be recommended for creation of stereoscopic systems, operating in real time and at high processing speed: devices for face recognition, systems for the position control of railway track, automobile active safety systems.

  7. Lost in Virtual Space: Studies in Human and Ideal Spatial Navigation

    Science.gov (United States)

    Stankiewicz, Brian J.; Legge, Gordon E.; Mansfield, J. Stephen; Schlicht, Erik J.

    2006-01-01

    The authors describe 3 human spatial navigation experiments that investigate how limitations of perception, memory, uncertainty, and decision strategy affect human spatial navigation performance. To better understand the effect of these variables on human navigation performance, the authors developed an ideal-navigator model for indoor navigation…

  8. Context-dependent spatially periodic activity in the human entorhinal cortex.

    Science.gov (United States)

    Nadasdy, Zoltan; Nguyen, T Peter; Török, Ágoston; Shen, Jason Y; Briggs, Deborah E; Modur, Pradeep N; Buchanan, Robert J

    2017-04-25

    The spatially periodic activity of grid cells in the entorhinal cortex (EC) of the rodent, primate, and human provides a coordinate system that, together with the hippocampus, informs an individual of its location relative to the environment and encodes the memory of that location. Among the most defining features of grid-cell activity are the 60° rotational symmetry of grids and preservation of grid scale across environments. Grid cells, however, do display a limited degree of adaptation to environments. It remains unclear if this level of environment invariance generalizes to human grid-cell analogs, where the relative contribution of visual input to the multimodal sensory input of the EC is significantly larger than in rodents. Patients diagnosed with nontractable epilepsy who were implanted with entorhinal cortical electrodes performing virtual navigation tasks to memorized locations enabled us to investigate associations between grid-like patterns and environment. Here, we report that the activity of human entorhinal cortical neurons exhibits adaptive scaling in grid period, grid orientation, and rotational symmetry in close association with changes in environment size, shape, and visual cues, suggesting scale invariance of the frequency, rather than the wavelength, of spatially periodic activity. Our results demonstrate that neurons in the human EC represent space with an enhanced flexibility relative to neurons in rodents because they are endowed with adaptive scalability and context dependency.

  9. Perception of activity based costing in Australian universities

    Directory of Open Access Journals (Sweden)

    Monir Zaman

    2011-07-01

    Full Text Available The study examines the perception of activity based costing (ABC in Australian universities. Using a questionnaire survey, data was collected from twenty-six finance directors and/or chief financial officers in Australian universities. The perception of ABC implementation in Australian universities depends on many variables including the understanding of ABC, consideration of ABC as a strategic cost management system, the role of ABC in reduction of expenses, consideration of ABC as a valuable tool to enhance overhead cost allocation, and consideration of ABC as an effective strategic cost management system designed to incorporate the university’s critical input, output, and process variables resulting in value creation. The result of regression analysis provides significant and positive association between the decision to implement ABC in Australian universities and both the treatment of ABC as a strategic cost management system and the degree of both senior management and internal champion support. The findings indicate substantial differences in the allocation of the overhead costs between ABC and traditional costing systems. The result also reveals that many Australian universities using the ABC method receive benefits in improving cost reduction and better resource allocation with revenue surplus. Furthermore, the study develops a generic model of cost pools and drivers of ABC implementation in Australian universities.

  10. What we remember affects how we see: spatial working memory steers saccade programming.

    Science.gov (United States)

    Wong, Jason H; Peterson, Matthew S

    2013-02-01

    Relationships between visual attention, saccade programming, and visual working memory have been hypothesized for over a decade. Awh, Jonides, and Reuter-Lorenz (Journal of Experimental Psychology: Human Perception and Performance 24(3):780-90, 1998) and Awh et al. (Psychological Science 10(5):433-437, 1999) proposed that rehearsing a location in memory also leads to enhanced attentional processing at that location. In regard to eye movements, Belopolsky and Theeuwes (Attention, Perception & Psychophysics 71(3):620-631, 2009) found that holding a location in working memory affects saccade programming, albeit negatively. In three experiments, we attempted to replicate the findings of Belopolsky and Theeuwes (Attention, Perception & Psychophysics 71(3):620-631, 2009) and determine whether the spatial memory effect can occur in other saccade-cuing paradigms, including endogenous central arrow cues and exogenous irrelevant singletons. In the first experiment, our results were the opposite of those in Belopolsky and Theeuwes (Attention, Perception & Psychophysics 71(3):620-631, 2009), in that we found facilitation (shorter saccade latencies) instead of inhibition when the saccade target matched the region in spatial working memory. In Experiment 2, we sought to determine whether the spatial working memory effect would generalize to other endogenous cuing tasks, such as a central arrow that pointed to one of six possible peripheral locations. As in Experiment 1, we found that saccade programming was facilitated when the cued location coincided with the saccade target. In Experiment 3, we explored how spatial memory interacts with other types of cues, such as a peripheral color singleton target or irrelevant onset. In both cases, the eyes were more likely to go to either singleton when it coincided with the location held in spatial working memory. On the basis of these results, we conclude that spatial working memory and saccade programming are likely to share common

  11. PERCEPTION STIMULATION GROUP ACTIVITY THERAPY INCREASES E CHILDREN SELF ESTEEM AT PRISON

    Directory of Open Access Journals (Sweden)

    Ah. Yusuf

    2017-07-01

    Full Text Available Introduction: Prison is societal implementer unit which accommodate care and develop the delinquent children. It was recorded that 57% of children at Blitar Child Prison undergo some self concept problems such as low self esteem. This was caused by some factors such as society’s stigmatization toward criminals, development pattern and education, and less support from family. If the self esteem problem is not being overcome soon, the children may  fell useless, disable to control their self and recrime when they are back to society. The objective of this study was to analyze the influence of  GAT (Group Activity Therapy perception stimulation in increasing the children  self esteem at prison. Method:  A quasy experimental pre post control design was used in this study. Samples were recruited by using total sampling and there were 22 samples as on inclusion criteria. The independent variable was GAT perception stimulation and the dependent variable was increasing self esteem of these childen. Data were collected by using questionnare and analyzed by using Wilcoxon Signed Ranks Test and Mann Whitney U Test with the significance level α≤0.05.Result:  The result showed that controlled group has significance level was p=0.654, it is mean there was no self esteem change before and after GAT perception stimulation was given. Whereas treatment group has significance level was p=0.001, it revealed that  there was self esteem change before and after GAT perception stimulation was given. The result of Mann Whitney U Test showed p=0.000 which means was accepted. Discussion: It can be concluded that perception stimulation can increase the children self esteem at prison. Further studies are recommended to study the effect of GAT perception stimulation modified by skill therapy in increasing children self esteem in prison.

  12. Social dataset analysis and mapping tools for Risk Perception: resilience, people preparation and communication tools

    Science.gov (United States)

    Peters-Guarin, Graciela; Garcia, Carolina; Frigerio, Simone

    2010-05-01

    Perception has been identified as resource and part of the resilience of a community to disasters. Risk perception, if present, may determine the potential damage a household or community experience. Different levels of risk perception and preparedness can influence directly people's susceptibility and the way they might react in case of an emergency caused by natural hazards. In spite of the profuse literature about risk perception, works to spatially portray this feature are really scarce. The spatial relationship to danger or hazard is being recognised as an important factor of the risk equation; it can be used as a powerful tool either for better knowledge or for operational reasons (e.g. management of preventive information). Risk perception and people's awareness when displayed in a spatial format can be useful for several actors in the risk management arena. Local authorities and civil protection can better address educational activities to increase the preparation of particularly vulnerable groups of clusters of households within a community. It can also be useful for the emergency personal in order to optimally direct the actions in case of an emergency. In the framework of the Marie Curie Research Project, a Community Based Early Warning System (CBEWS) it's been developed in the Mountain Community Valtellina of Tirano, northern Italy. This community has been continuously exposed to different mass movements and floods, in particular, a large event in 1987 which affected a large portion of the valley and left 58 dead. The actual emergency plan for the study area is composed by a real time, highly detailed, decision support system. This emergency plan contains detailed instructions for the rapid deployment of civil protection and other emergency personal in case of emergency, for risk scenarios previously defined. Especially in case of a large event, where timely reaction is crucial for reducing casualties, it is important for those in charge of emergency

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

    Science.gov (United States)

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

    2016-02-01

    When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Elementary Schoolchildren's Perceived Competence and Physical Activity Involvement: The Influence of Parents' Role Modelling Behaviours and Perceptions of their Child's Competence

    OpenAIRE

    Bois, Julien; Sarrazin, Philippe; Brustad, Robert; Trouilloud, David; Cury, François

    2005-01-01

    International audience; Objectives. To study the influence of fathers' and mothers' physical activity involvement and perceptions of their children's physical competence upon children's perceptions of competence and children's time spent in physical activity. Two forms of parental socialization influence were assessed: the direct influence of parents' actual physical activity (PA) behaviour (role modelling) on children's physical activity and the indirect influence of parents' beliefs systems...

  15. Characterizing permafrost active layer dynamics and sensitivity to landscape spatial heterogeneity in Alaska

    Science.gov (United States)

    Yi, Yonghong; Kimball, John S.; Chen, Richard H.; Moghaddam, Mahta; Reichle, Rolf H.; Mishra, Umakant; Zona, Donatella; Oechel, Walter C.

    2018-01-01

    An important feature of the Arctic is large spatial heterogeneity in active layer conditions, which is generally poorly represented by global models and can lead to large uncertainties in predicting regional ecosystem responses and climate feedbacks. In this study, we developed a spatially integrated modeling and analysis framework combining field observations, local-scale ( ˜ 50 m resolution) active layer thickness (ALT) and soil moisture maps derived from low-frequency (L + P-band) airborne radar measurements, and global satellite environmental observations to investigate the ALT sensitivity to recent climate trends and landscape heterogeneity in Alaska. Modeled ALT results show good correspondence with in situ measurements in higher-permafrost-probability (PP ≥ 70 %) areas (n = 33; R = 0.60; mean bias = 1.58 cm; RMSE = 20.32 cm), but with larger uncertainty in sporadic and discontinuous permafrost areas. The model results also reveal widespread ALT deepening since 2001, with smaller ALT increases in northern Alaska (mean trend = 0.32±1.18 cm yr-1) and much larger increases (> 3 cm yr-1) across interior and southern Alaska. The positive ALT trend coincides with regional warming and a longer snow-free season (R = 0.60 ± 0.32). A spatially integrated analysis of the radar retrievals and model sensitivity simulations demonstrated that uncertainty in the spatial and vertical distribution of soil organic carbon (SOC) was the largest factor affecting modeled ALT accuracy, while soil moisture played a secondary role. Potential improvements in characterizing SOC heterogeneity, including better spatial sampling of soil conditions and advances in remote sensing of SOC and soil moisture, will enable more accurate predictions of active layer conditions and refinement of the modeling framework across a larger domain.

  16. Spatial variability of caesium-137 activities in soils in the Jura mountains

    International Nuclear Information System (INIS)

    Pimou-Heumou, G.; Lucot, E.; Crini, N.; Briot, M.; Badot, P.M.

    2011-01-01

    275 soil samples were taken in the catchment area of the upper part of the Doubs river located in the Jura mountains according to a sampling strategy designed to evaluate the extent of the spatial variability of 137 Cs activities and to identify its main sources. 137 Cs activities ranged between about 1000 and 12000 Bq.m -2 with an average of approximately 3600 Bq.m -2 . The spatial variability of the contamination is high: 137 Cs activity shows statistically significant links with altitude, soil organic matter and land cover, whereas the other studied parameters, i.e. soil type and topographic position, do not constitute significant sources of variation. These results are discussed in terms of evaluation of the radioactive contamination on a regional scale. They show that to be satisfactory, a sampling strategy must necessarily take into account the various types of land cover. (authors)

  17. Inquiring Sport and Physical Activity students’ perceptions using metaphors as research tools

    OpenAIRE

    Martínez Ruiz, María Ángeles; Ávalos Ramos, María Alejandra; Merma Molina, Gladys

    2017-01-01

    The aim of this study is to analyse the metaphorical expressions designed by Science of Sport and Physical Activity university students, as a tool of inquiring two research questions: their perceptions of their physical education teachers, and the meaning physical activity has in students’ personal life. 51 students from the University of Alicante have participated in the study. Qualitative data analysis software AQUAD 6 was used for data processing. The results obtained from the analysis of ...

  18. Reentrant processing in intuitive perception.

    Directory of Open Access Journals (Sweden)

    Phan Luu

    Full Text Available The process of perception requires not only the brain's receipt of sensory data but also the meaningful organization of that data in relation to the perceptual experience held in memory. Although it typically results in a conscious percept, the process of perception is not fully conscious. Research on the neural substrates of human visual perception has suggested that regions of limbic cortex, including the medial orbital frontal cortex (mOFC, may contribute to intuitive judgments about perceptual events, such as guessing whether an object might be present in a briefly presented fragmented drawing. Examining dense array measures of cortical electrical activity during a modified Waterloo Gestalt Closure Task, results show, as expected, that activity in medial orbital frontal electrical responses (about 250 ms was associated with intuitive judgments. Activity in the right temporal-parietal-occipital (TPO region was found to predict mOFC (approximately 150 ms activity and, in turn, was subsequently influenced by the mOFC at a later time (approximately 300 ms. The initial perception of gist or meaning of a visual stimulus in limbic networks may thus yield reentrant input to the visual areas to influence continued development of the percept. Before perception is completed, the initial representation of gist may support intuitive judgments about the ongoing perceptual process.

  19. The Active Duty Primigravada's Perception of Prenatal Care in the Military Health Care System

    National Research Council Canada - National Science Library

    Brady, Vicki

    1998-01-01

    .... In this study a qualitative descriptive design using the active duty primigravada as the population of interest was used to explore perceptions of and satisfaction with prenatal care in the military health care system...

  20. The spatial structure of transnational human activity.

    Science.gov (United States)

    Deutschmann, Emanuel

    2016-09-01

    Starting from conflictive predictions of hitherto disconnected debates in the natural and social sciences, this article examines the spatial structure of transnational human activity (THA) worldwide (a) across eight types of mobility and communication and (b) in its development over time. It is shown that the spatial structure of THA is similar to that of animal displacements and local-scale human motion in that it can be approximated by Lévy flights with heavy tails that obey power laws. Scaling exponent and power-law fit differ by type of THA, being highest in refuge-seeking and tourism and lowest in student exchange. Variance in the availability of resources and opportunities for satisfying associated needs appears to explain these differences. Over time (1960-2010), the Lévy-flight pattern remains intact and remarkably stable, contradicting the popular notion that socio-technological trends lead to a "death of distance." Humans have not become more "global" over time, they rather became more mobile in general, i.e. they move and communicate more at all distances. Hence, it would be more adequate to speak of "mobilization" than of "globalization." Longitudinal change occurs only in some types of THA and predominantly at short distances, indicating regional rather than global shifts. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. The role of physical activity, body mass index and maturity status in body-related perceptions and self-esteem of adolescents.

    Science.gov (United States)

    Altıntaş, A; Aşçı, F H; Kin-İşler, A; Güven-Karahan, B; Kelecek, S; Özkan, A; Yılmaz, A; Kara, F M

    2014-01-01

    Adolescence represents a transitional period which is marked by physical, social and psychological changes. Changes in body shape and physical activity especially alter and shape the psychological well-being of adolescents. The purpose of this study was to determine the role of physical activity level, body mass index and maturity status in body-related perception and self-esteem of 11-18 years old adolescents. A total of 1012 adolescents participated in this study. The "Social Physique Anxiety Scale", "Body Image Satisfaction Scale", "Physical Self-Perception Profile for Children" and "Rosenberg Self-Esteem Inventory" were administered. Physical activity level and body mass index were assessed using the "Physical Activity Questionnaire" and "Bioelectrical Impedance Analyzer", respectively. Regression analysis indicated that body mass index was the only predictor of perceived body attractiveness, social physique anxiety, body image satisfaction and self-esteem for female adolescents. For male adolescents, both physical activity and body mass index were correlated with perceived body attractiveness and social physique anxiety. Pubertal status were not correlated with self-esteem and body-related perceptions for both males and females adolescents. In summary, body mass index and physical activity plays an important role in body-related perceptions and self-esteem of adolescents.

  2. Non-Critical-Care Nurses' Perceptions of Facilitators and Barriers to Rapid Response Team Activation.

    Science.gov (United States)

    Jenkins, Sheryl Henry; Astroth, Kim Schafer; Woith, Wendy Mann

    2015-01-01

    Rapid response teams can save lives but are only effective when activated. We surveyed 50 nurses for their perceptions of facilitators and barriers to activation. Findings showed that participants need more education on their role and when to activate the rapid response team. Nurses who comprise the team need help building their communication skills. We recommend nursing professional development specialists increase the frequency of offerings and expand the focus on roles, activation criteria, and communication skills.

  3. An Analysis of Piecewise-Linear and Convex Value Functions for Active Perception POMDPs

    NARCIS (Netherlands)

    Satsangi, Y.; Whiteson, S.; Spaan, M.T.J.

    2015-01-01

    In active perception tasks, an agent aims to select actions that reduce its uncertainty about a hidden state. While partially observable Markov decision processes (POMDPs) are a natural model for such problems, reward functions that directly penalize uncertainty in the agent's belief can remove the

  4. Are kids too busy?: early adolescents' perceptions of discretionary activities, overscheduling, and stress.

    Science.gov (United States)

    Brown, Stephen L; Nobiling, Brandye D; Teufel, James; Birch, David A

    2011-09-01

    The activity patterns of children, especially after-school patterns, are receiving more professional attention. However, evidence regarding the value of various activities in children's lives is contradictory. The purpose of this study was to assess perceptions of discretionary activities, overscheduling, and levels of stress from adolescents' perspective. A sample of 882 children, ages 9 to 13, recruited at 9 health education centers in the United States was selected for this study. Children answered questionnaires using remote, handheld devices. Data were analyzed using descriptive statistics and multivariate logistic regression. The outcomes of interest were activity-based stress and desire for more free time. The primary predictor for the desire for more free time was hours of screen time (television, computer, video games): those who reported 3 or more hours were nearly 3 times more likely to desire more free time. Further, children who chose their own activities experienced more activity-related stress than those who shared decisions with parents. The single greatest predictor of activity-related stress was the reported number of hours spent on homework. Students who averaged at least 2 hours on homework per night were nearly twice as likely to report frequent activity-related stress. Parents of school-aged children should assess activity-related stress and the degree to which children perceive they are busy. Teachers, school counselors, and school administrators should be aware of these perceptions as they are making decisions regarding school schedules and should teach personal skills such as time management and stress control. © 2011, American School Health Association.

  5. Spatial Abilities of High-School Students in the Perception of Geologic Structures.

    Science.gov (United States)

    Kali, Yael; Orion, Nir

    1996-01-01

    Characterizes specific spatial abilities required in geology studies through the examination of the performance of high school students in solving structural geology problems on the geologic spatial ability test (GeoSAT). Concludes that visual penetration ability and the ability to perceive the spatial configuration of the structure are…

  6. From left to right: Processing acronyms referring to names of political parties activates spatial associations

    NARCIS (Netherlands)

    Elk, M. van; Schie, H.T. van; Bekkering, H.

    2010-01-01

    In line with previous studies, showing that abstract concepts like opowero or ogodo implicitly activate spatial associations, in the present study we hypothesized that spatial associations are coactivated during the processing of acronyms referring to names of political parties as well. In four

  7. An analysis of weight perception and physical activity and dietary behaviours among youth in the COMPASS study

    Directory of Open Access Journals (Sweden)

    Karen A. Patte

    2016-12-01

    Full Text Available Purpose: Weight misperceptions appear common among youth, potentially influencing their motivation to engage in health-related behaviours; however, the direction of impact remains unclear. The current study examined how weight perception influences physical activity (PA and diet among youth. Methods: This study used 2-year linked data of 19,322 grade 9–12 students from Year 2 (Y2:2013-2014 and 3 (Y3:2014-2015 of the COMPASS study. Generalized Estimating Equation models tested the effect of Y3 weight perception on the various Y3 PA and dietary behaviour measures, adjusting for Y3 covariates (grade, race/ethnicity, weekly spending money, school cluster, school area median household income, and the Y2 outcome. Models were stratified by gender and body mass index (BMI classification. Results: Regardless of BMI status, overweight perceptions among boys and girls were associated with lower likelihoods of playing school sports, physical education class enrollment, meeting resistance exercise recommendations, eating breakfast regularly, and less vigorous-intensity PA, and among boys only, lower odds of meeting PA guidelines, compared to their peers who perceived their weight as “about right”. In boys with normal-weight BMIs, underweight perceptions predicted less vigorous-intensity PA, and lower odds of physical education class enrollment, and of meeting PA and resistance exercise recommendations, than “about right” perceptions. Among girls, underweight perceptions predicted lower likelihoods of engaging in adequate resistance exercise and playing intramurals, and greater odds of eating fast food on weekends, purchasing snacks, and drinking energy drinks and sugar-sweetened beverages. Girls with overweight/obese BMIs who perceived their weight as such were less likely to consume adequate fruits and vegetables relative to their counterparts with “about right” weight perceptions. Conclusions: Overall, weight perceptions of “about right

  8. MEG source localization of spatially extended generators of epileptic activity: comparing entropic and hierarchical bayesian approaches.

    Science.gov (United States)

    Chowdhury, Rasheda Arman; Lina, Jean Marc; Kobayashi, Eliane; Grova, Christophe

    2013-01-01

    Localizing the generators of epileptic activity in the brain using Electro-EncephaloGraphy (EEG) or Magneto-EncephaloGraphy (MEG) signals is of particular interest during the pre-surgical investigation of epilepsy. Epileptic discharges can be detectable from background brain activity, provided they are associated with spatially extended generators. Using realistic simulations of epileptic activity, this study evaluates the ability of distributed source localization methods to accurately estimate the location of the generators and their sensitivity to the spatial extent of such generators when using MEG data. Source localization methods based on two types of realistic models have been investigated: (i) brain activity may be modeled using cortical parcels and (ii) brain activity is assumed to be locally smooth within each parcel. A Data Driven Parcellization (DDP) method was used to segment the cortical surface into non-overlapping parcels and diffusion-based spatial priors were used to model local spatial smoothness within parcels. These models were implemented within the Maximum Entropy on the Mean (MEM) and the Hierarchical Bayesian (HB) source localization frameworks. We proposed new methods in this context and compared them with other standard ones using Monte Carlo simulations of realistic MEG data involving sources of several spatial extents and depths. Detection accuracy of each method was quantified using Receiver Operating Characteristic (ROC) analysis and localization error metrics. Our results showed that methods implemented within the MEM framework were sensitive to all spatial extents of the sources ranging from 3 cm(2) to 30 cm(2), whatever were the number and size of the parcels defining the model. To reach a similar level of accuracy within the HB framework, a model using parcels larger than the size of the sources should be considered.

  9. MEG source localization of spatially extended generators of epileptic activity: comparing entropic and hierarchical bayesian approaches.

    Directory of Open Access Journals (Sweden)

    Rasheda Arman Chowdhury

    Full Text Available Localizing the generators of epileptic activity in the brain using Electro-EncephaloGraphy (EEG or Magneto-EncephaloGraphy (MEG signals is of particular interest during the pre-surgical investigation of epilepsy. Epileptic discharges can be detectable from background brain activity, provided they are associated with spatially extended generators. Using realistic simulations of epileptic activity, this study evaluates the ability of distributed source localization methods to accurately estimate the location of the generators and their sensitivity to the spatial extent of such generators when using MEG data. Source localization methods based on two types of realistic models have been investigated: (i brain activity may be modeled using cortical parcels and (ii brain activity is assumed to be locally smooth within each parcel. A Data Driven Parcellization (DDP method was used to segment the cortical surface into non-overlapping parcels and diffusion-based spatial priors were used to model local spatial smoothness within parcels. These models were implemented within the Maximum Entropy on the Mean (MEM and the Hierarchical Bayesian (HB source localization frameworks. We proposed new methods in this context and compared them with other standard ones using Monte Carlo simulations of realistic MEG data involving sources of several spatial extents and depths. Detection accuracy of each method was quantified using Receiver Operating Characteristic (ROC analysis and localization error metrics. Our results showed that methods implemented within the MEM framework were sensitive to all spatial extents of the sources ranging from 3 cm(2 to 30 cm(2, whatever were the number and size of the parcels defining the model. To reach a similar level of accuracy within the HB framework, a model using parcels larger than the size of the sources should be considered.

  10. Spatial Change as Drivers of Risk and Vulnerability in South Africa: Spatial trends in the 3 metropolitan cities of Gauteng

    CSIR Research Space (South Africa)

    Pieterse, Amy

    2016-07-01

    Full Text Available Urban spatial change trends manifest most noticeably in Gauteng. This not only confirms perceptions about metros as increasingly being the spaces where the future of South Africa's youth will be determined, but also once again rings the alarm bells...

  11. Is there a role of visual cortex in spatial hearing?

    Science.gov (United States)

    Zimmer, Ulrike; Lewald, Jörg; Erb, Michael; Grodd, Wolfgang; Karnath, Hans-Otto

    2004-12-01

    The integration of auditory and visual spatial information is an important prerequisite for accurate orientation in the environment. However, while visual spatial information is based on retinal coordinates, the auditory system receives information on sound location in relation to the head. Thus, any deviation of the eyes from a central position results in a divergence between the retinal visual and the head-centred auditory coordinates. It has been suggested that this divergence is compensated for by a neural coordinate transformation, using a signal of eye-in-head position. Using functional magnetic resonance imaging, we investigated which cortical areas of the human brain participate in such auditory-visual coordinate transformations. Sounds were produced with different interaural level differences, leading to left, right or central intracranial percepts, while subjects directed their gaze to visual targets presented to the left, to the right or straight ahead. When gaze was to the left or right, we found the primary visual cortex (V1/V2) activated in both hemispheres. The occipital activation did not occur with sound lateralization per se, but was found exclusively in combination with eccentric eye positions. This result suggests a relation of neural processing in the visual cortex and the transformation of auditory spatial coordinates responsible for maintaining the perceptual alignment of audition and vision with changes in gaze direction.

  12. Visual-Spatial Art and Design Literacy as a Prelude to Aesthetic Growth

    Science.gov (United States)

    Lerner, Fern

    2018-01-01

    In bridging ideas from the forum of visual-spatial learning with those of art and design learning, inspiration is taken from Piaget who explained that the evolution of spatial cognition occurs through perception, as well as through thought and imagination. Insights are embraced from interdisciplinary educational theorists, intertwining and…

  13. Merger and Acquisition Activity as Driver of Spatial Clustering : The Spatial Evolution of the Dutch Banking Industry, 1850-1993

    NARCIS (Netherlands)

    Boschma, Ron; Hartog, Matté

    2014-01-01

    This article investigates the extent to which merger and acquisition (M&A) activity contributed to the spatial clustering of the Dutch banking industry in Amsterdam. This analysis is based on a unique database of all banks in the Netherlands that existed in the period 1850-1993. We found that

  14. Spatial resolution dependence on spectral frequency in human speech cortex electrocorticography

    Science.gov (United States)

    Muller, Leah; Hamilton, Liberty S.; Edwards, Erik; Bouchard, Kristofer E.; Chang, Edward F.

    2016-10-01

    Objective. Electrocorticography (ECoG) has become an important tool in human neuroscience and has tremendous potential for emerging applications in neural interface technology. Electrode array design parameters are outstanding issues for both research and clinical applications, and these parameters depend critically on the nature of the neural signals to be recorded. Here, we investigate the functional spatial resolution of neural signals recorded at the human cortical surface. We empirically derive spatial spread functions to quantify the shared neural activity for each frequency band of the electrocorticogram. Approach. Five subjects with high-density (4 mm center-to-center spacing) ECoG grid implants participated in speech perception and production tasks while neural activity was recorded from the speech cortex, including superior temporal gyrus, precentral gyrus, and postcentral gyrus. The cortical surface field potential was decomposed into traditional EEG frequency bands. Signal similarity between electrode pairs for each frequency band was quantified using a Pearson correlation coefficient. Main results. The correlation of neural activity between electrode pairs was inversely related to the distance between the electrodes; this relationship was used to quantify spatial falloff functions for cortical subdomains. As expected, lower frequencies remained correlated over larger distances than higher frequencies. However, both the envelope and phase of gamma and high gamma frequencies (30-150 Hz) are largely uncorrelated (<90%) at 4 mm, the smallest spacing of the high-density arrays. Thus, ECoG arrays smaller than 4 mm have significant promise for increasing signal resolution at high frequencies, whereas less additional gain is achieved for lower frequencies. Significance. Our findings quantitatively demonstrate the dependence of ECoG spatial resolution on the neural frequency of interest. We demonstrate that this relationship is consistent across patients and

  15. The connection between the primary care and the physical activity sector: professionals' perceptions

    NARCIS (Netherlands)

    Leenaars, K.E.; Florisson, A.M.; Smit, E.; Wagemakers, A.; Molleman, G.R.M.; Koelen, M.A.

    2016-01-01

    BACKGROUND: To stimulate physical activity (PA) and guide primary care patients towards local PA facilities, Care Sport Connectors (CSC), to whom a broker role has been ascribed, were introduced in 2012 in the Netherlands. The aim of this study is to assess perceptions of primary care, welfare, and

  16. School climate in peer bullying: observers' and active participants' perceptions

    Directory of Open Access Journals (Sweden)

    Sonja Pečjak

    2017-09-01

    Full Text Available Peer bullying is a phenomenon present in all schools. The school as an institution has a major role in limiting peer bullying. The primary goal of the study was to determine how different groups of students perceived school climate in relation to peer bullying regarding their role in peer bullying (active participants: bullies, victims, bully-victims and non-active participants: observers. 414 students (from 18 primary and secondary schools responded to The School Climate Bullying Survey (SCBS; Cornell, 2012, which measures the incidence of various forms of peer bullying and three dimensions of school climate (prevalence of teasing and bullying, aggressive attitudes, and willingness to seek help. The results showed that the active participants in peer bullying report a frequent presence of verbal and social bullying (54% and 40%, respectively and a significantly lower frequency of physical and cyber bullying (14%. The largest differences between the groups of students were found in their perceptions of the prevalence of aggressive attitudes and willingness to seek help in a school context. In the perceptions of both of these dimensions we found a high degree of similarity between the groups of bullies and victim-bullies, and between the groups of victims and observers. The first two groups, when compared to the victims and observers, perceived to a greater extent that school allows aggression as a way of affirmation among peers and in school in general, and that neither teachers nor peers do not stop the bullying, which discourages the victims from seeking help from them. The results confirmed the existence of the association between students’ perceived school climate by bullying and their behavior (roles in peer bullying.

  17. Sudanese Students' Perceptions of Their Class Activities: Psychometric Properties and Measurement Invariance of My Class Activities--Arabic Language Version

    Science.gov (United States)

    Pereira, Nielsen; Bakhiet, Salaheldin Farah; Gentry, Marcia; Balhmar, Tahani Abdulrahman; Hakami, Sultan Mohammed

    2017-01-01

    This study examined the psychometric properties and measurement invariance of the Arabic version of "My Class Activities" (MCA), an instrument designed to measure students' perceptions of interest, challenge, choice, and enjoyment in classrooms. Scores of 3,516 Sudanese students in Grades 2 to 8 were used. Confirmatory factor analysis…

  18. Activity limitations in the lower extremities in patients with osteoarthritis: the modifying effects of illness perceptions and mental health.

    Science.gov (United States)

    Botha-Scheepers, S; Riyazi, N; Kroon, H M; Scharloo, M; Houwing-Duistermaat, J J; Slagboom, E; Rosendaal, F R; Breedveld, F C; Kloppenburg, M

    2006-11-01

    Using the International Classification of Functioning, Disability and Health as framework, we evaluated modifying effects of illness perceptions and mental health on the association between impairments in body structures and functions due to osteoarthritis (OA) and limitation in activities in the lower extremities. Self-reported limitation in activities was assessed by the Western Ontario and McMaster Universities OA index (WOMAC) function subscale in 316 patients with knee or hip pain or evidence of OA on knee or hip radiographs. Body structures and functions were evaluated during clinical and radiological assessments. Illness perceptions and mental health were assessed with the revised Illness Perception Questionnaire (IPQ-R) and the mental component summary score of the RAND 36-item Health Survey, respectively. For each patient an expected WOMAC function score was calculated, using an equation based on a multivariate model of the association of body structures and functions with limitation in activities. The median (interquartile) self-reported WOMAC function score was 22.2 (9.6-43.5). Ninety-one patients reported more and 120 patients reported less limitation in activities than expected. Patients with lumbar spine degeneration, physical or exercise therapy and high IPQ-R identity, consequences and chronic timeline scores had an increased risk to report more limitation in activities than the expected range. Low IPQ-R identity, consequences and emotional representation scores and better mental health were associated with reporting less limitation in activities than the expected range. Illness perceptions and mental health modify the association between self-reported limitation in activities and calculated limitation in activities based on impairments in body structures and functions due to OA.

  19. Research progress of functional magnetic resonance imaging in cross-modal activation of visual cortex during tactile perception

    International Nuclear Information System (INIS)

    Zhan Jie; Gong Honghan

    2013-01-01

    An increasing amount of neuroimaging studies recently demonstrated activation of visual cortex in both blind and sighted participants when performing a variety of tactile tasks such as Braille reading and tactile object recognition, which indicates that visual cortex not only receives visual information, but may participate in tactile perception. To address these cross-modal changes of visual cortex and the neurophysiological mechanisms, many researchers conducted explosive studies using functional magnetic resonance imaging (fMRI) and have made some achievements. This review focuses on cross-modal activation of visual cortex and the underlying mechanisms during tactile perception in both blind and sighted individuals. (authors)

  20. Perception of built environmental factors and physical activity among adolescents in Nigeria

    Science.gov (United States)

    2014-01-01

    Background Understanding environmental factors related to adolescents’ physical activity can inform intervention for obesity control and prevention, but virtually no study has been conducted in the African region, where adolescents’ physical inactivity and chronic diseases rates are rising. This study assessed associations between perceived built environmental variables and adolescents’ physical activity (active transportation to school and leisure-time moderate-to- vigorous physical activity), and the moderating effects of neighborhood-level income on association between environmental variables and physical activity among Nigerian boys and girls. Methods Participants were 1006 adolescents (12–19 years, 50.4% girls) randomly selected from 11 secondary schools in Maiduguri city, Nigeria. Physical activity and perceptions of environmental characteristics were assessed by validated self-report questionnaires. Separate gender-based, hierarchical multiple moderated linear regression analyses were used to examine the direct associations between the environmental perceptions and physical activity variables (active transportation and leisure-time MVPA; dependent variables), as well as the moderating effects of neighborhood-level income. Results Only in boys were direct associations and interaction effect of neighborhood-level income found. Access to destinations was positively associated with active transportation to school (β = 0.18; CI = 0.67, 2.24); while residential density (β = 0.10; CI = 0.01, 1.74) and availability/quality of infrastructures (β = 0.14; CI = 0.49, 2.68) were positively associated with leisure-time MVPA. Also, neighborhood-level income moderated the association between perceived safety and leisure-time MVPA, with more perceived safety related to less MVPA (β = -0.16; CI = -0.01, -0.70) in boys living in high SES neighborhood but marginally related to more MVPA (β = 0.11; CI = -0.04, 2.88, p = 0

  1. Student Perceptions of Auditor Responses to Evidence of Suspicious Activities: An Experimental Assessment

    Directory of Open Access Journals (Sweden)

    David S Murphy

    2015-12-01

    Full Text Available This study assessed student perceptions of auditor responses to evidence that a client failed to respond appropriately to suspicious activities that could indicate money laundering. Subjects were presented with a series of randomized cases in which partner type (new vs. experienced, firm type (regional vs. international and audit fee materiality (not material, material to the local office only, material to the firm were manipulated asked to indicate their perceptions of the likelihood that an audit partner would discuss such evidence with the client, and the likelihood that the issue would be disclosed by the auditor. Both partner type and audit fee materiality was found to have significant effects on perceived likelihoods.

  2. Spatial auditory attention is modulated by tactile priming.

    Science.gov (United States)

    Menning, Hans; Ackermann, Hermann; Hertrich, Ingo; Mathiak, Klaus

    2005-07-01

    Previous studies have shown that cross-modal processing affects perception at a variety of neuronal levels. In this study, event-related brain responses were recorded via whole-head magnetoencephalography (MEG). Spatial auditory attention was directed via tactile pre-cues (primes) to one of four locations in the peripersonal space (left and right hand versus face). Auditory stimuli were white noise bursts, convoluted with head-related transfer functions, which ensured spatial perception of the four locations. Tactile primes (200-300 ms prior to acoustic onset) were applied randomly to one of these locations. Attentional load was controlled by three different visual distraction tasks. The auditory P50m (about 50 ms after stimulus onset) showed a significant "proximity" effect (larger responses to face stimulation as well as a "contralaterality" effect between side of stimulation and hemisphere). The tactile primes essentially reduced both the P50m and N100m components. However, facial tactile pre-stimulation yielded an enhanced ipsilateral N100m. These results show that earlier responses are mainly governed by exogenous stimulus properties whereas cross-sensory interaction is spatially selective at a later (endogenous) processing stage.

  3. The importance of vertical buildings in perception and memorising the city

    Science.gov (United States)

    Alihodzic, Rifat; Zupančič, Domen

    2018-03-01

    Being aware of the surrounding we live in, among other things, means establishing of spatial relationships between oneself and the environment, equally important as relationship between oneself and others. Environment consists of facilities and space. Space, "gift by itself", is defined by terrain topography, sky horizon, plants and animals. The architecture, as a profession, is interested in space created distinctively. Perception, as elementary process of consciousness and psychological life, deals with being conscious about something. In this case, physical structures that create a city. Psychological experience of urban environment is important factor having effect on perception, memorising and orientation in urban space. Gestalt psychology of perceiving is area applying to and significant for architecture either. The importance of vertical lies in its perceiving the gravitation, forming perceiving focus, landmark, for urban units and subunits to be memorised, creating spatial hierarchy and perception logics, remembering and orientation in space. This work analyses reasons for building upright with comparative analyses in their participation in space and on human psychology. This paper's purpose is to, using fundamental facts, show the importance of vertical buildings, not as a spatial use phenomenon, but also as significant phenomenon.

  4. Performing Perception - Staging Aesthetics of Interaction

    DEFF Research Database (Denmark)

    Dalsgaard, Peter; Hansen, Lone Koefoed

    2008-01-01

    In interaction design for experience-oriented uses of technology, a central facet of aesthetics of interaction is rooted in the user's experience of herself “performing her perception.” By drawing on performance (theater) theory, phenomenology and sociology and with references to recent HCI...... experience. We argue that this 3-in-1 is always already shaping the user's understanding and perception of her interaction as it is staged through her experience of the object's form and expression. Through examples ranging from everyday technologies utilizing performances of interaction to spatial...... contemporary artworks, digital as well as analogue, we address the notion of the performative spectator and the spectating performer. We demonstrate how perception is also performative and how focus on this aspect seems to be crucial when designing experience-oriented products, systems and services....

  5. Cortical visual prostheses: from microstimulation to functional percept

    Science.gov (United States)

    Najarpour Foroushani, Armin; Pack, Christopher C.; Sawan, Mohamad

    2018-04-01

    Cortical visual prostheses are intended to restore vision by targeted electrical stimulation of the visual cortex. The perception of spots of light, called phosphenes, resulting from microstimulation of the visual pathway, suggests the possibility of creating meaningful percept made of phosphenes. However, to date electrical stimulation of V1 has still not resulted in perception of phosphenated images that goes beyond punctate spots of light. In this review, we summarize the clinical and experimental progress that has been made in generating phosphenes and modulating their associated perceptual characteristics in human and macaque primary visual cortex (V1). We focus specifically on the effects of different microstimulation parameters on perception and we analyse key challenges facing the generation of meaningful artificial percepts. Finally, we propose solutions to these challenges based on the application of supervised learning of population codes for spatial stimulation of visual cortex.

  6. Testing the generality of the zoom-lens model: Evidence for visual-pathway specific effects of attended-region size on perception.

    Science.gov (United States)

    Goodhew, Stephanie C; Lawrence, Rebecca K; Edwards, Mark

    2017-05-01

    There are volumes of information available to process in visual scenes. Visual spatial attention is a critically important selection mechanism that prevents these volumes from overwhelming our visual system's limited-capacity processing resources. We were interested in understanding the effect of the size of the attended area on visual perception. The prevailing model of attended-region size across cognition, perception, and neuroscience is the zoom-lens model. This model stipulates that the magnitude of perceptual processing enhancement is inversely related to the size of the attended region, such that a narrow attended-region facilitates greater perceptual enhancement than a wider region. Yet visual processing is subserved by two major visual pathways (magnocellular and parvocellular) that operate with a degree of independence in early visual processing and encode contrasting visual information. Historically, testing of the zoom-lens has used measures of spatial acuity ideally suited to parvocellular processing. This, therefore, raises questions about the generality of the zoom-lens model to different aspects of visual perception. We found that while a narrow attended-region facilitated spatial acuity and the perception of high spatial frequency targets, it had no impact on either temporal acuity or the perception of low spatial frequency targets. This pattern also held up when targets were not presented centrally. This supports the notion that visual attended-region size has dissociable effects on magnocellular versus parvocellular mediated visual processing.

  7. An understanding of Japanese children's perceptions of fun, barriers, and facilitators of active free play.

    Science.gov (United States)

    Lee, YingHua; Takenaka, Koji; Kanosue, Kazuyuki

    2015-09-01

    Physical activity contributes to children's physical and mental well-being. Research suggests that active free play helps to maintain and increase physical activity in children and also contributes to social and emotional well-being. To date, these studies have focused on Western countries. Thus, this study was conducted to gain insights into the factors of perceptions of fun, barriers, and facilitators affecting active free play from the perspective of Japanese children using focus group interviews. In Japan, 12 focus groups were conducted with 60 children aged 9-11 years. Children's perceptions of fun in active free play were categorized into socializing, achievement, emotions, and freedom. Additionally, active boys' groups were interested in free play and adventure play; girls' groups were interested in free play with less physical movement and challenges; inactive boys' groups were interested in relaxing and competitive play with bodily contact. However, children mentioned that busy schedules, weather, and health-related factors acted as main barriers. Lastly, children noted facilitators include setting schedules, having access to equipment and playgrounds, and holding special events. The findings provide insights into active free play-related factors for active and inactive Japanese children and also clarify the differences between Japanese and Western children. Such findings will contribute to designing interventions to increase active free play. © The Author(s) 2013.

  8. Students’ Perception on Pre-reading Activities in Basic Reading II Class of the English Language Education Study Program of Sanata Dharma University

    Directory of Open Access Journals (Sweden)

    Vindy Cahya Ekaningrum

    2016-12-01

    Full Text Available The students’ perception on the teacher instruction shows whether the teaching techniques meet the students’ need or not. Because of this reason, the researcher wants to find out the varieties of pre-reading activities used by the teacher and the students’ perception on the implementation of the pre-reading activities. There were two problem formulations in this study: 1 What kinds of pre-reading activities that are used by Basic Reading II teacher in the English Language Education Study Program of Sanata Dharma University? 2 How is the students’ perception on pre-reading activities used by the teacher? This research was a survey research. In gathering the data, there were two instruments used in this research. They were interview and questionnaire. The interview was done by interviewing the teacher of Basic Reading II Class. The interview was used to answer the first research question about the varieties of pre-reading activities in Basic Reading II class. Then, the researcher distributed the questionnaire to 56 students of Basic Reading II class. The questionnaire was used to answer the second research question about the students’ perception on pre-reading activities used by the teacher. The result of this research showed that brainstorming, pre-teaching vocabulary, pre-questioning, visual aids, and KWL strategy were the varieties of pre-reading activities used by the teacher. There were two different implementation of pre-teaching vocabulary. There were also two activities combined together, they were the use of visual aids and KWL strategy. The students had positive perception on the implementation of pre-reading activities in Basic Reading II Class.   DOI: https://doi.org/10.24071/llt.2015.180206

  9. Perception of 3-D location based on vision, touch, and extended touch.

    Science.gov (United States)

    Giudice, Nicholas A; Klatzky, Roberta L; Bennett, Christopher R; Loomis, Jack M

    2013-01-01

    Perception of the near environment gives rise to spatial images in working memory that continue to represent the spatial layout even after cessation of sensory input. As the observer moves, these spatial images are continuously updated. This research is concerned with (1) whether spatial images of targets are formed when they are sensed using extended touch (i.e., using a probe to extend the reach of the arm) and (2) the accuracy with which such targets are perceived. In Experiment 1, participants perceived the 3-D locations of individual targets from a fixed origin and were then tested with an updating task involving blindfolded walking followed by placement of the hand at the remembered target location. Twenty-four target locations, representing all combinations of two distances, two heights, and six azimuths, were perceived by vision or by blindfolded exploration with the bare hand, a 1-m probe, or a 2-m probe. Systematic errors in azimuth were observed for all targets, reflecting errors in representing the target locations and updating. Overall, updating after visual perception was best, but the quantitative differences between conditions were small. Experiment 2 demonstrated that auditory information signifying contact with the target was not a factor. Overall, the results indicate that 3-D spatial images can be formed of targets sensed by extended touch and that perception by extended touch, even out to 1.75 m, is surprisingly accurate.

  10. GENDER DIFFERENCES AMONGST AFRICAN GENERATION Y STUDENTS’ PERCEPTIONS OF FASHION MARKETING ACTIVITIES

    Directory of Open Access Journals (Sweden)

    Heleneze-Tiane Lues

    2016-07-01

    Full Text Available The purpose of this study was to determine whether gender differences existamongst African Generation Y students’ perceptions concerning selectedmarketing activities of their preferred clothing brand. The African Generation Ycohort (individuals born between 1986 and 2005 in South Africa, represents animportant market segment in that it makes up 32 per cent of the country’spopulation. As one of the largest contributors to the South African economy, thefashion retail industry is experiencing intense competition amongst fashion brandsand retailers due to an increased amount of national and international brandsavailable to consumers. Consequently, the need for effective differentiation, suchas branding, is becoming more significant. In light of this, it is increasinglyimportant for marketers and brand managers to define their target market clearly,which requires a sound understanding of their target market’s needs and thecontributors of consumer behaviour, of which gender is a key factor. This studyused a self-administered questionnaire to collect data from a convenience sampleof 750 students across three South African public higher education institution’campuses situated in the Gauteng province. The collected data were analysedusing descriptive statistics and a two independent-samples t-test. The findings suggest that while there is no statistically significant difference between male andfemale participants’ perceptions concerning their preferred clothing brands’advertising and product activities, statistically significant differences were foundconcerning the store image and pricing activities of their preferred clothing brand.

  11. Physical Activity and Health Perception in Aging: Do Body Mass and Satisfaction Matter? A Three-Path Mediated Link.

    Directory of Open Access Journals (Sweden)

    Giancarlo Condello

    Full Text Available Although ageing people could benefit from healthy diet and physical activity to maintain health and quality of life, further understandings of the diet- and physical activity-related mechanisms that may cause changes in health and quality of life perception are necessary. The purpose of the study was to investigate the effect of eating attitudes, body mass and image satisfaction, and exercise dependence in the relationship between physical activity and health and quality of life perception in older individuals. Hundred and seventy-nine late middle-aged, (55-64 yrs, young-old (65-74 yrs, and old (75-84 yrs senior athletes (n = 56, physically active (n = 58 or sedentary adults (n = 65 were submitted to anthropometric evaluations (body mass, height and self-reported questionnaires: Body Image Dimensional Assessment, Exercise Dependence Scale, Eating Attitude Test, and Short Form Health Survey (Physical Component Summary [PCS] and Mental Component Summary [MCS] of and health and quality of life perception. Senior athletes, physically active, and sedentary participants subgroups differed (P<0.05 from each other in body mass index (BMI and several components of body image and exercise dependence. Senior athletes showed, compared to their sedentary counterparts, further differences (P<0.05 in eating attitudes and in both PCS and MCS. Mediation analysis showed that the relationship between physical activity habit and MCS, but not PCS, was indirectly explained by a serial mediation chain composed of objective BMI and subjective body image (dissatisfaction. Findings confirm the relevant role of physically active life habits for older individuals to perceive good physical and mental health. The novelty of the three-path mediated link between physical activity level and mental health perception suggests that the beneficial effect of a physically active lifestyle on weight control can positively impinge on the cognitive-emotional dimension of mental health

  12. Can a school physical activity intervention improve physical self-perception and enjoyment?

    DEFF Research Database (Denmark)

    Lund-Cramer, Pernille; Christiansen, Lars Breum Skov; Smedegaard, Søren

    Purpose Physical activity at school can improve mental health of all children – especially if it is targeted to children’s needs and executed in a positive social climate. The purpose of the present study was to examine the effect of a multicomponent school-based physical activity intervention...... activity in recess. Using a cluster-randomized design, 24 Danish schools were randomized to either intervention or control. Study population included 3.136 children aged 10-13 years at baseline. Survey data (socio-demographics, physical activity, self-efficacy, physical enjoyment, physical self...... on physical self-perception and enjoyment of physical activity among children aged 10-13 years. Methods An intervention based on Self-Determination Theory was developed and pilot tested in close co-operation with schools and targeted 1) physical education lessons, 2) in-class activity, and 3) physical...

  13. Hippocampal activation during the recall of remote spatial memories in radial maze tasks.

    Science.gov (United States)

    Schlesiger, Magdalene I; Cressey, John C; Boublil, Brittney; Koenig, Julie; Melvin, Neal R; Leutgeb, Jill K; Leutgeb, Stefan

    2013-11-01

    Temporally graded retrograde amnesia is observed in human patients with medial temporal lobe lesions as well as in animal models of medial temporal lobe lesions. A time-limited role for these structures in memory recall has also been suggested by the observation that the rodent hippocampus and entorhinal cortex are activated during the retrieval of recent but not of remote memories. One notable exception is the recall of remote memories for platform locations in the water maze, which requires an intact hippocampus and results in hippocampal activation irrespective of the age of the memory. These findings raise the question whether the hippocampus is always involved in the recall of spatial memories or, alternatively, whether it might be required for procedural computations in the water maze task, such as for calculating a path to a hidden platform. We performed spatial memory testing in radial maze tasks to distinguish between these possibilities. Radial maze tasks require a choice between spatial locations on a center platform and thus have a lesser requirement for navigation than the water maze. However, we used a behavioral design in the radial maze that retained other aspects of the standard water maze task, such as the use of multiple start locations and retention testing in a single trial. Using the immediate early gene c-fos as a marker for neuronal activation, we found that all hippocampal subregions were more activated during the recall of remote compared to recent spatial memories. In areas CA3 and CA1, activation during remote memory testing was higher than in rats that were merely reexposed to the testing environment after the same time interval. Conversely, Fos levels in the dentate gyrus were increased after retention testing to the extent that was also observed in the corresponding exposure control group. This pattern of hippocampal activation was also obtained in a second version of the task that only used a single start arm instead of multiple

  14. The influence of a working memory task on affective perception of facial expressions.

    Directory of Open Access Journals (Sweden)

    Seung-Lark Lim

    Full Text Available In a dual-task paradigm, participants performed a spatial location working memory task and a forced two-choice perceptual decision task (neutral vs. fearful with gradually morphed emotional faces (neutral ∼ fearful. Task-irrelevant word distractors (negative, neutral, and control were experimentally manipulated during spatial working memory encoding. We hypothesized that, if affective perception is influenced by concurrent cognitive load using a working memory task, task-irrelevant emotional distractors would bias subsequent perceptual decision-making on ambiguous facial expression. We found that when either neutral or negative emotional words were presented as task-irrelevant working-memory distractors, participants more frequently reported fearful face perception - but only at the higher emotional intensity levels of morphed faces. Also, the affective perception bias due to negative emotional distractors correlated with a decrease in working memory performance. Taken together, our findings suggest that concurrent working memory load by task-irrelevant distractors has an impact on affective perception of facial expressions.

  15. Brain activity dynamics in human parietal regions during spontaneous switches in bistable perception.

    Science.gov (United States)

    Megumi, Fukuda; Bahrami, Bahador; Kanai, Ryota; Rees, Geraint

    2015-02-15

    The neural mechanisms underlying conscious visual perception have been extensively investigated using bistable perception paradigms. Previous functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies suggest that the right anterior superior parietal (r-aSPL) and the right posterior superior parietal lobule (r-pSPL) have opposite roles in triggering perceptual reversals. It has been proposed that these two areas are part of a hierarchical network whose dynamics determine perceptual switches. However, how these two parietal regions interact with each other and with the rest of the brain during bistable perception is not known. Here, we investigated such a model by recording brain activity using fMRI while participants viewed a bistable structure-from-motion stimulus. Using dynamic causal modeling (DCM), we found that resolving such perceptual ambiguity was specifically associated with reciprocal interactions between these parietal regions and V5/MT. Strikingly, the strength of bottom-up coupling between V5/MT to r-pSPL and from r-pSPL to r-aSPL predicted individual mean dominance duration. Our findings are consistent with a hierarchical predictive coding model of parietal involvement in bistable perception and suggest that visual information processing underlying spontaneous perceptual switches can be described as changes in connectivity strength between parietal and visual cortical regions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  16. The determinants of total entrepreneurial activity : a spatial approach / by Albertus Jacobus Meintjes

    OpenAIRE

    Meintjes, Albertus Jakobus

    2006-01-01

    Various bodies and governments from around the world have recognised the importance of entrepreneurship in economic growth and job creation. The rate of start-up businesses and entrepreneurial activity is crucial in every country. The Global Entrepreneurship Monitor (GEM) recognises the contribution of entrepreneurial activity to economic growth and measures it by means of the total entrepreneurial activity (TEA) index. Most recent evidence suggests that regional (or spatial...

  17. Lung cancer risk perception and distress: difference by smoking status, and role of physical activity and race among US population

    Directory of Open Access Journals (Sweden)

    Sunil Mathur

    2013-06-01

    Full Text Available Background: cigarette smoking is the greatest known risk factor for lung cancer, and people with different smoking status may process risk information differently. While psychological distress has been linked with smoking status, little is known about the impact of distress on lung cancer perception or the moderating role of physical activity and race. This study explores the association of lung cancer perception and distress and investigates the effects of physical activity and race on that association.Methods: the study uses a national, biennial survey (the Health Information National Trends Survey that was designed to collect nationally representative data on the American public’s need for, access to, and use of cancer-related information using a cross-sectional, complex sample survey design. Out of 5 586 participants, 1 015 were current smokers, 1 599 were former smokers, 2 877 were never smokers. Of the sample, 1 765 participants answered the lung cancer risk perception question and had no personal history of lung cancer. Statistical analysis contrasts smokers, former smokers, and never smokers to examine the association of lung cancer perception and distress and the moderating role of physical activity and race.Results: distress and lung cancer risk perception were significantly positively associated (p value < 0.001. Respondents who were current smokers and were distressed had very high odds of agreeing that they have a somewhat high chance (odds ratio=900.8, CI: 94.23, 8 611.75; p value < 0.001 or a very high chance (odds ratio=500.44 CI: 56.53, 4 430.02, p value < 0.001 of developing lung cancer in the future as compared to not distressed never smokers. However, race and physical activity status did not significantly affect perception of risk. Perceptions of risk are important precursors of health change.Conclusions: elevated distress level and higher perceived risk, in addition to physical activity status and race, could potentially

  18. Representations and processes of human spatial competence.

    Science.gov (United States)

    Gunzelmann, Glenn; Lyon, Don R

    2011-10-01

    This article presents an approach to understanding human spatial competence that focuses on the representations and processes of spatial cognition and how they are integrated with cognition more generally. The foundational theoretical argument for this research is that spatial information processing is central to cognition more generally, in the sense that it is brought to bear ubiquitously to improve the adaptivity and effectiveness of perception, cognitive processing, and motor action. We describe research spanning multiple levels of complexity to understand both the detailed mechanisms of spatial cognition, and how they are utilized in complex, naturalistic tasks. In the process, we discuss the critical role of cognitive architectures in developing a consistent account that spans this breadth, and we note some areas in which the current version of a popular architecture, ACT-R, may need to be augmented. Finally, we suggest a framework for understanding the representations and processes of spatial competence and their role in human cognition generally. Copyright © 2011 Cognitive Science Society, Inc.

  19. Environment perception and leisure-time physical activity in Portuguese high school students

    Directory of Open Access Journals (Sweden)

    Rita Pereira

    2018-06-01

    Full Text Available This study aims to analyze the association between perceived environmental factors and leisure-time physical activity (PA among adolescents of both genders. Data were collected in autumn of 2011 from 866 adolescents (412 girls and 454 boys 12- to 18-years-old, from four Portuguese cities. Perception of environmental factors was assessed by Assessing Levels of Physical Activity and Fitness (ALPHA questionnaire (Spittaels et al., 2010, IJBNPA. PA was assessed by a questionnaire that evaluated PA during leisure-time and participants were assigned into the following categories: sedentary; low active; moderate active; and very active. Boys presented higher levels of structured PA, frequency and intensity of PA, and level of sport competition than girls (p<0.001. Distance to local facilities (p=0.001 for girls; p<0.001 for boys and home environment (p=0.004 for girls; p=0.015 for boys were negatively associated with PA. Total, cycling and walking infrastructures (p<0.001, as well as cycling and walking network (p=0.049 and connectivity (p=0.034 showed a positive association with PA in boys. Analysis of variance showed significant differences between girls' PA regarding aesthetics (p=0.013, study environment (p=0.023, home environment (p=0.014 and whether it is pleasant or not (p=0.023. Differences between boys' PA were observed for distance to local facilities (p=0.003, total, cycling and walking infrastructures (p<0.001 and home environment (p=0.002. This study results support that some environmental factors are associated with adolescents' PA levels, with relevant differences between genders. Therefore, these gender differences must be taken into account, in order to increase levels of PA in Portuguese youth, especially in girls. Keywords: Environment perception, Physical activity, Adolescents, ALPHA questionnaire

  20. Health perceptions, self and body image, physical activity and nutrition among undergraduate students in Israel.

    Science.gov (United States)

    Korn, Liat; Gonen, Ester; Shaked, Yael; Golan, Moria

    2013-01-01

    This study examines health perceptions, self and body image, physical exercise and nutrition among undergraduate students. A structured, self-reported questionnaire was administered to more than 1500 students at a large academic institute in Israel. The study population was heterogenic in both gender and fields of academic study. High correlations between health perceptions, appropriate nutrition, and positive self and body image were found. The relationships between these variables differed between the subpopulation in the sample and the different genders. Engagement in physical exercise contributed to positive body image and positive health perceptions more than engagement in healthy nutrition. Nutrition students reported higher frequencies of positive health perceptions, positive self and body image and higher engagement in physical exercise in comparison to all other students in the sample. This study suggests, as have many before, that successful health promotion policy should reflect a collectivist rather than an individualist ethos by providing health prerequisites through a public policy of health-promotion, where the academic settings support a healthy lifestyle policy, by increasing availability of a healthy, nutritious and varied menu in the cafeterias, and offering students various activities that enhance healthy eating and exercise. IMPLICATIONS AND CONTRIBUTION: This study examined health perceptions, self-image, physical exercise and nutrition among undergraduate students and found high correlations between these topics. Nutrition students reported higher frequencies of positive health perceptions, and positive self and body image and engaged more in physical exercise when compared with all other students in the sample.

  1. Pre-Service Teachers' Perception of Quick Response (QR) Code Integration in Classroom Activities

    Science.gov (United States)

    Ali, Nagla; Santos, Ieda M.; Areepattamannil, Shaljan

    2017-01-01

    Quick Response (QR) codes have been discussed in the literature as adding value to teaching and learning. Despite their potential in education, more research is needed to inform practice and advance knowledge in this field. This paper investigated the integration of the QR code in classroom activities and the perceptions of the integration by…

  2. A case study on the perception of aging and participation in physical activities of older Chinese immigrants in Australia.

    Science.gov (United States)

    Koo, Fung Kuen

    2011-10-01

    This qualitative study explores how older Hong Kong ChineseAustralians perceive aging and to what extent this perception affects their participation in physical activities. The main methods used were in-depth interviews with 22 participants ranging in age from 60 to 91 years. Interviews were translated from Chinese (Cantonese) and transcribed into English. Content analysis was used to find recurring themes from the interview data. The main findings indicate that the perception of aging is to some extent influenced by culture. Some participants defined aging as being measured in years, and others defined it by the state of one's physical health, appearance, and capacity to continue fulfilling one's social roles. These perceptions strongly influenced their preferences for and participation in physical activities. Acknowledging the fact that Chinese-speaking people are not culturally homogeneous, this article makes some recommendations to health service providers with regard to the development of appropriate physical activity programs.

  3. Feature integration and spatial attention: common processes for endogenous and exogenous orienting.

    Science.gov (United States)

    Henderickx, David; Maetens, Kathleen; Soetens, Eric

    2010-05-01

    Briand (J Exp Psychol Hum Percept Perform 24:1243-1256, 1998) and Briand and Klein (J Exp Psychol Hum Percept Perform 13:228-241, 1987) demonstrated that spatial cueing effects are larger for detecting conjunction of features than for detecting simple features when spatial attention is oriented exogenously, and not when attention is oriented endogenously. Their results were interpreted as if only exogenous attention affects the posterior spatial attention system that performs the feature binding function attributed to spatial attention by Treisman's feature integration theory (FIT; 1980). In a series of 6 experiments, we attempted to replicate Briand's findings. Manipulations of distractor string size and symmetry of stimulus presentation left and right from fixation were implemented in Posner's cueing paradigm. The data indicate that both exogenous and endogenous cueing address the same attentional mechanism needed for feature binding. The results also limit the generalisability of Briand's proposal concerning the role of exogenous attention in feature integration. Furthermore, the importance to control the effect of unintended attentional capture in a cueing task is demonstrated.

  4. Experiments with a First Prototype of a Spatial Model of Cultural Meaning through Natural-Language Human-Robot Interaction

    Directory of Open Access Journals (Sweden)

    Oliver Schürer

    2018-01-01

    Full Text Available When using assistive systems, the consideration of individual and cultural meaning is crucial for the utility and acceptance of technology. Orientation, communication and interaction are rooted in perception and therefore always happen in material space. We understand that a major problem lies in the difference between human and technical perception of space. Cultural policies are based on meanings including their spatial situation and their rich relationships. Therefore, we have developed an approach where the different perception systems share a hybrid spatial model that is generated by artificial intelligence—a joint effort by humans and assistive systems. The aim of our project is to create a spatial model of cultural meaning based on interaction between humans and robots. We define the role of humanoid robots as becoming our companions. This calls for technical systems to include still inconceivable human and cultural agendas for the perception of space. In two experiments, we tested a first prototype of the communication module that allows a humanoid to learn cultural meanings through a machine learning system. Interaction is achieved by non-verbal and natural-language communication between humanoids and test persons. This helps us to better understand how a spatial model of cultural meaning can be developed.

  5. Spatially Dispersed Employee Recovery

    DEFF Research Database (Denmark)

    Hvass, Kristian Anders; Torfadóttir, Embla

    2014-01-01

    Employee recovery addresses either employee well-being or management's practices in aiding employees in recovering themselves following a service failure. This paper surveys the cabin crew at a small, European, low-cost carrier and investigates employees' perceptions of management practices to aid...... personnel achieve service recovery. Employee recovery within service research often focuses on front-line employees that work in a fixed location, however a contribution to the field is made by investigating the recovery of spatially dispersed personnel, such as operational personnel in the transport sector......, who have a work place away from a fixed or central location and have minimal management contact. Results suggest that the support employees receive from management, such as recognition, information sharing, training, and strategic awareness are all important for spatially dispersed front...

  6. Geographic information systems, remote sensing, and spatial analysis activities in Texas, 2002-07

    Science.gov (United States)

    Pearson, D.K.; Gary, R.H.; Wilson, Z.D.

    2007-01-01

    Geographic information system (GIS) technology has become an important tool for scientific investigation, resource management, and environmental planning. A GIS is a computer-aided system capable of collecting, storing, analyzing, and displaying spatially referenced digital data. GIS technology is particularly useful when analyzing a wide variety of spatial data such as with remote sensing and spatial analysis. Remote sensing involves collecting remotely sensed data, such as satellite imagery, aerial photography, or radar images, and analyzing the data to gather information or investigate trends about the environment or the Earth's surface. Spatial analysis combines remotely sensed, thematic, statistical, quantitative, and geographical data through overlay, modeling, and other analytical techniques to investigate specific research questions. It is the combination of data formats and analysis techniques that has made GIS an essential tool in scientific investigations. This document presents information about the technical capabilities and project activities of the U.S. Geological Survey (USGS) Texas Water Science Center (TWSC) GIS Workgroup from 2002 through 2007.

  7. Citizen science: A new perspective to advance spatial pattern evaluation in hydrology.

    Science.gov (United States)

    Koch, Julian; Stisen, Simon

    2017-01-01

    Citizen science opens new pathways that can complement traditional scientific practice. Intuition and reasoning often make humans more effective than computer algorithms in various realms of problem solving. In particular, a simple visual comparison of spatial patterns is a task where humans are often considered to be more reliable than computer algorithms. However, in practice, science still largely depends on computer based solutions, which inevitably gives benefits such as speed and the possibility to automatize processes. However, the human vision can be harnessed to evaluate the reliability of algorithms which are tailored to quantify similarity in spatial patterns. We established a citizen science project to employ the human perception to rate similarity and dissimilarity between simulated spatial patterns of several scenarios of a hydrological catchment model. In total, the turnout counts more than 2500 volunteers that provided over 43000 classifications of 1095 individual subjects. We investigate the capability of a set of advanced statistical performance metrics to mimic the human perception to distinguish between similarity and dissimilarity. Results suggest that more complex metrics are not necessarily better at emulating the human perception, but clearly provide auxiliary information that is valuable for model diagnostics. The metrics clearly differ in their ability to unambiguously distinguish between similar and dissimilar patterns which is regarded a key feature of a reliable metric. The obtained dataset can provide an insightful benchmark to the community to test novel spatial metrics.

  8. A Mechanistic Link from GABA to Cortical Architecture and Perception.

    Science.gov (United States)

    Kolasinski, James; Logan, John P; Hinson, Emily L; Manners, Daniel; Divanbeighi Zand, Amir P; Makin, Tamar R; Emir, Uzay E; Stagg, Charlotte J

    2017-06-05

    Understanding both the organization of the human cortex and its relation to the performance of distinct functions is fundamental in neuroscience. The primary sensory cortices display topographic organization, whereby receptive fields follow a characteristic pattern, from tonotopy to retinotopy to somatotopy [1]. GABAergic signaling is vital to the maintenance of cortical receptive fields [2]; however, it is unclear how this fine-grain inhibition relates to measurable patterns of perception [3, 4]. Based on perceptual changes following perturbation of the GABAergic system, it is conceivable that the resting level of cortical GABAergic tone directly relates to the spatial specificity of activation in response to a given input [5-7]. The specificity of cortical activation can be considered in terms of cortical tuning: greater cortical tuning yields more localized recruitment of cortical territory in response to a given input. We applied a combination of fMRI, MR spectroscopy, and psychophysics to substantiate the link between the cortical neurochemical milieu, the tuning of cortical activity, and variability in perceptual acuity, using human somatosensory cortex as a model. We provide data that explain human perceptual acuity in terms of both the underlying cellular and metabolic processes. Specifically, higher concentrations of sensorimotor GABA are associated with more selective cortical tuning, which in turn is associated with enhanced perception. These results show anatomical and neurochemical specificity and are replicated in an independent cohort. The mechanistic link from neurochemistry to perception provides a vital step in understanding population variability in sensory behavior, informing metabolic therapeutic interventions to restore perceptual abilities clinically. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  9. Crowding in Visual Working Memory Reveals Its Spatial Resolution and the Nature of Its Representations.

    Science.gov (United States)

    Tamber-Rosenau, Benjamin J; Fintzi, Anat R; Marois, René

    2015-09-01

    Spatial resolution fundamentally limits any image representation. Although this limit has been extensively investigated for perceptual representations by assessing how neighboring flankers degrade the perception of a peripheral target with visual crowding, the corresponding limit for representations held in visual working memory (VWM) is unknown. In the present study, we evoked crowding in VWM and directly compared resolution in VWM and perception. Remarkably, the spatial resolution of VWM proved to be no worse than that of perception. However, mixture modeling of errors caused by crowding revealed the qualitatively distinct nature of these representations. Perceptual crowding errors arose from both increased imprecision in target representations and substitution of flankers for targets. By contrast, VWM crowding errors arose exclusively from substitutions, which suggests that VWM transforms analog perceptual representations into discrete items. Thus, although perception and VWM share a common resolution limit, exceeding this limit reveals distinct mechanisms for perceiving images and holding them in mind. © The Author(s) 2015.

  10. Influence of parental perception of school safety and gender on children's physical activity in Mexico: A cross sectional study.

    Science.gov (United States)

    Hutchens, Amy; Soltero, Erica G; Barquera, Simón; Lévesque, Lucie; Jauregui, Edtna; López Y Taylor, Juan; Lee, Rebecca E

    2016-01-01

    This cross sectional study aims to determine the effects of gender and parental perception of safety at school on children's physical activity (PA) levels. Parents of school aged Mexican children residing in Guadalajara, Mexico City, and Puerto Vallarta, completed surveys about their children's PA measures. The physical activity indicators were evaluated using linear and logistical regression models. Analysis did not indicate that gender moderated the relationship between parental perception of safety and PA measures, but significant gender issues exist with girls participating less than boys in the three measures of PA in this study (p<0.001). Results suggest the need for additional interventions promoting physical activity in girls in Mexico.

  11. Perceptions, Expectations, and Informal Supports Influence Exercise Activity in Frail Older Adults

    Directory of Open Access Journals (Sweden)

    Louise Broderick

    2015-04-01

    Full Text Available This study aims to explore frail older adults’ perceptions of what influences their exercise behaviors. A qualitative descriptive design was used. Semi-structured, open-ended interviews were conducted with 29 frail older adults. Thematic content analysis established the findings. Frail older adults perceive exercise as a by-product of other purposeful activities such as manual work or social activities. Progression into frailty appears to be associated with a decline in non-family support, changing traditional roles within family support networks, and lower baseline activity levels. Frail older adults perceive exercise as incidental to more purposeful activities rather than an endpoint in itself. Therefore, exercise programs concentrating on functional outcomes may be more relevant for this population. Strategies that educate and promote social support networks may also benefit frail older adults.

  12. Disease insight and treatment perception of men on active surveillance for early prostate cancer

    NARCIS (Netherlands)

    van den Bergh, Roderick C. N.; van Vugt, Heidi A.; Korfage, Ida J.; Steyerberg, Ewout W.; Roobol, Monique J.; Schröder, Fritz H.; Essink-Bot, Marie-Louise

    2010-01-01

    OBJECTIVE To investigate the levels of knowledge of prostate cancer and the perception of active surveillance (AS) in men on AS, as AS for early prostate cancer instead of radical treatment might partly solve the over-treatment dilemma in this disease, but might be experienced as a complex and

  13. Do You Hear What I Hear? Overweight Children's Perceptions of Different Physical Activity Settings

    Science.gov (United States)

    Meaney, Karen; Hart, Melanie A.; Griffin, L. Kent

    2011-01-01

    Social-Cognitive Theory (Bandura, 1986, 1999) served as the framework to explore overweight children's perceptions of different physical activity settings. Participants were children (n = 67) enrolled in an after-school and summer program for overweight African-American and Hispanic-American children from low-income families. To gain insight into…

  14. Associations between parents' perception of neighbourhood environments and safety with physical activity of primary school children in Klang, Selangor, Malaysia.

    Science.gov (United States)

    Tung, S E H; Ng, X H; Chin, Y S; Mohd Taib, M N

    2016-07-01

    This study aimed to evaluate parental perception of neighbourhood environments and safety in association with children's physical activity among primary school children in Klang, Selangor, Malaysia. A total of 250 children (9-12 years of age) and their parents participated in this cross-sectional study. Physical Activity Questionnaire for Older Children and Neighbourhood Environmental Walkability Scale as well as questions on constrained behaviours (avoidance and defensive behaviours) were used to assess the children's physical activity and parental perception of neighbourhood environment and safety, respectively. More than one-third (36.0%) of the children were physically inactive compared with only a small percentage (4.8%) who were physically active, with boys achieving higher physical activity levels than girls (t = 2.564, P = 0.011). For the environmental scale, parents' perception of land-use mix (access) (r = 0.173, P = 0.006), traffic hazards (r = -0.152, P = 0.016) and defensive behaviour (r = -0.024, P = 0.143) correlated significantly with children's physical activity. In multiple linear regression analysis, child's gender (β = -0.226; P = 0.003), parent's education (β = 0.140; P = 0.001), household income (β = 0.151; P = 0.024), land-use mix (access) (β = 0.134; P = 0.011) and defensive behaviour (β = -0.017; P = 0.038) were significantly associated with physical activity in children (R = 0.349, F = 6.760; P safety and constrained behaviours with their children's participation in active play. Interventions aimed to increase actual and perceived safety and reduce perceptions of risk by parents in safe neighbourhoods can be targeted to increase children's physical activity in their local neighbourhoods. © 2016 John Wiley & Sons Ltd.

  15. Intelligent judgements over health risks in a spatial agent-based model.

    Science.gov (United States)

    Abdulkareem, Shaheen A; Augustijn, Ellen-Wien; Mustafa, Yaseen T; Filatova, Tatiana

    2018-03-20

    Millions of people worldwide are exposed to deadly infectious diseases on a regular basis. Breaking news of the Zika outbreak for instance, made it to the main media titles internationally. Perceiving disease risks motivate people to adapt their behavior toward a safer and more protective lifestyle. Computational science is instrumental in exploring patterns of disease spread emerging from many individual decisions and interactions among agents and their environment by means of agent-based models. Yet, current disease models rarely consider simulating dynamics in risk perception and its impact on the adaptive protective behavior. Social sciences offer insights into individual risk perception and corresponding protective actions, while machine learning provides algorithms and methods to capture these learning processes. This article presents an innovative approach to extend agent-based disease models by capturing behavioral aspects of decision-making in a risky context using machine learning techniques. We illustrate it with a case of cholera in Kumasi, Ghana, accounting for spatial and social risk factors that affect intelligent behavior and corresponding disease incidents. The results of computational experiments comparing intelligent with zero-intelligent representations of agents in a spatial disease agent-based model are discussed. We present a spatial disease agent-based model (ABM) with agents' behavior grounded in Protection Motivation Theory. Spatial and temporal patterns of disease diffusion among zero-intelligent agents are compared to those produced by a population of intelligent agents. Two Bayesian Networks (BNs) designed and coded using R and are further integrated with the NetLogo-based Cholera ABM. The first is a one-tier BN1 (only risk perception), the second is a two-tier BN2 (risk and coping behavior). We run three experiments (zero-intelligent agents, BN1 intelligence and BN2 intelligence) and report the results per experiment in terms of

  16. Spatial summation and spatial discrimination of cold pain: effect of spatial configuration and skin type.

    Science.gov (United States)

    Defrin, Ruth; Sheraizin, Anat; Malichi, Liron; Shachen, Orit

    2011-12-01

    Spatial summation (SS) and spatial discrimination (SD) are essential for pain perception. In the cold-pain sensation, these processes have hardly been studied. Our aim was to study the SS and SD of cold pain, as well as the SS of cold-pain threshold (CPT) in hairy and glabrous skin. Two discrete stimuli (9 cm(2) each) were applied to the forearm with separation distances of 0-40 cm and in addition, a single stimulus on each forearm. For each configuration, the CPT, suprathreshold cold-pain ratings, and the reported number of activated stimuli (SD) were obtained. In another experiment, SS of CPT was tested in the hairy and glabrous skin of the hand using small (2.25 cm(2)) and large (9 cm(2)) probe sizes. The SS of CPT and of cold pain existed over separation distances of up to 30-40 cm, at which point SD became better than chance. When the 2 forearms were stimulated, SS was abolished and cold pain was inhibited. CPT was significantly higher in hairy than glabrous skin, but the amount of SS of CPT was similar in the 2 skin types. Noxious cold-evoked thermal qualities were more common in the glabrous than the hairy skin. (1) SS and SD of cold pain are reciprocal; (2) whereas cold pain can summate over large distances, the SD of cold pain is poor; (3) SS of cold pain does not exist between contralateral body sides, however, inhibition occurs; (4) SS is independent of skin type and sensitivity to cold pain; (5) differences in pain quality between hairy and glabrous skin may reflect innervation differences. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  17. Adapted Physical Activity Programme and Self-Perception in Obese Adolescents with Intellectual Disability: Between Morphological Awareness and Positive Illusory Bias

    Science.gov (United States)

    Salaun, Laureline; Reynes, Eric; Berthouze-Aranda, Sophie E.

    2014-01-01

    Background: In adolescents with intellectual disability, the management of obesity is a crucial issue, yet also quite complex because of their particular perception of themselves. This study investigated the relationship between self-perception variables and morphological variables and their changes after a 9-month Adapted Physical Activity (APA)…

  18. Language, Perception, and the Schematic Representation of Spatial Relations

    Science.gov (United States)

    Amorapanth, Prin; Kranjec, Alexander; Bromberger, Bianca; Lehet, Matthew; Widick, Page; Woods, Adam J.; Kimberg, Daniel Y.; Chatterjee, Anjan

    2012-01-01

    Schemas are abstract nonverbal representations that parsimoniously depict spatial relations. Despite their ubiquitous use in maps and diagrams, little is known about their neural instantiation. We sought to determine the extent to which schematic representations are neurally distinguished from language on the one hand, and from rich perceptual…

  19. How community environment shapes physical activity: perceptions revealed through the PhotoVoice method.

    Science.gov (United States)

    Belon, Ana Paula; Nieuwendyk, Laura M; Vallianatos, Helen; Nykiforuk, Candace I J

    2014-09-01

    A growing body of evidence shows that community environment plays an important role in individuals' physical activity engagement. However, while attributes of the physical environment are widely investigated, sociocultural, political, and economic aspects of the environment are often neglected. This article helps to fill these knowledge gaps by providing a more comprehensive understanding of multiple dimensions of the community environment relative to physical activity. The purpose of this study was to qualitatively explore how people's experiences and perceptions of their community environments affect their abilities to engage in physical activity. A PhotoVoice method was used to identify barriers to and opportunities for physical activity among residents in four communities in the province of Alberta, Canada, in 2009. After taking pictures, the thirty-five participants shared their perceptions of those opportunities and barriers in their community environments during individual interviews. Using the Analysis Grid for Environments Linked to Obesity (ANGELO) framework, themes emerging from these photo-elicited interviews were organized in four environment types: physical, sociocultural, economic, and political. The data show that themes linked to the physical (56.6%) and sociocultural (31.4%) environments were discussed more frequently than the themes of the economic (5.9%) and political (6.1%) environments. Participants identified nuanced barriers and opportunities for physical activity, which are illustrated by their quotes and photographs. The findings suggest that a myriad of factors from physical, sociocultural, economic, and political environments influence people's abilities to be physically active in their communities. Therefore, adoption of a broad, ecological perspective is needed to address the barriers and build upon the opportunities described by participants to make communities more healthy and active. Copyright © 2014 Elsevier Ltd. All rights

  20. Evidence for cue-independent spatial representation in the human auditory cortex during active listening.

    Science.gov (United States)

    Higgins, Nathan C; McLaughlin, Susan A; Rinne, Teemu; Stecker, G Christopher

    2017-09-05

    Few auditory functions are as important or as universal as the capacity for auditory spatial awareness (e.g., sound localization). That ability relies on sensitivity to acoustical cues-particularly interaural time and level differences (ITD and ILD)-that correlate with sound-source locations. Under nonspatial listening conditions, cortical sensitivity to ITD and ILD takes the form of broad contralaterally dominated response functions. It is unknown, however, whether that sensitivity reflects representations of the specific physical cues or a higher-order representation of auditory space (i.e., integrated cue processing), nor is it known whether responses to spatial cues are modulated by active spatial listening. To investigate, sensitivity to parametrically varied ITD or ILD cues was measured using fMRI during spatial and nonspatial listening tasks. Task type varied across blocks where targets were presented in one of three dimensions: auditory location, pitch, or visual brightness. Task effects were localized primarily to lateral posterior superior temporal gyrus (pSTG) and modulated binaural-cue response functions differently in the two hemispheres. Active spatial listening (location tasks) enhanced both contralateral and ipsilateral responses in the right hemisphere but maintained or enhanced contralateral dominance in the left hemisphere. Two observations suggest integrated processing of ITD and ILD. First, overlapping regions in medial pSTG exhibited significant sensitivity to both cues. Second, successful classification of multivoxel patterns was observed for both cue types and-critically-for cross-cue classification. Together, these results suggest a higher-order representation of auditory space in the human auditory cortex that at least partly integrates the specific underlying cues.

  1. Coarse-to-Fine Encoding of Spatial Frequency Information into Visual Short-Term Memory for Faces but Impartial Decay

    Science.gov (United States)

    Gao, Zaifeng; Bentin, Shlomo

    2011-01-01

    Face perception studies investigated how spatial frequencies (SF) are extracted from retinal display while forming a perceptual representation, or their selective use during task-imposed categorization. Here we focused on the order of encoding low-spatial frequencies (LSF) and high-spatial frequencies (HSF) from perceptual representations into…

  2. [Parents´perception of childhood overweight and obesity and eating behaviors, physical activity and sedentary lifestyle of their children. Spain].

    Science.gov (United States)

    Rodríguez Martín, Amelia; Novalbos Ruiz, José P; Villagran Pérez, Sergio; Martínez Nieto, José M; Lechuga Campoy, José L

    2012-10-01

    Parents often do not perceive their children's excess weight, and therefore not modified their lifestyles. We study how often this actually occurs and whether this perception is associated with differences in dietary habits, physical activity and sedentary in children. Cross-sectional study of 1620 children aged 3-16 years selected by multi-stage sampling (2008-2010) of which 454 children had excess weight. We studied family anthropometric characteristics, dietary habits, physical activity (adapted questionnaires Cindi/Marathon), and sedentary lifestyle. We analyze the differences in children with normal weight, unperceived and perceived excess weight (chi² test and ANOVA). Parents receive 34.7% of overweight cases and 72.3% obesity cases of their sons, and a 10.8% and 53,8% respectively in daughters. Obese parents recognize a 54.5% and 57,7% of cases of excess weight in sons, compared to 23.8% and 27,8% in daughters. Perception of excess weight was associated with the professional qualifications of the father (47%) and be a housewife (40%). Excess weight parents' perception coincided with more compliance with physical activity recommendations in younger's sons (67.5% vs. 77.3%) and daughters (47.5% vs. 55.6%), and a lower frequency of sedentary in 3-9 years girls (42.6% vs. 38.9%). According to parents' excess weight perception we found slight differences in dietary by gender and age group of children. A significant percentage of children´s excess weight is not perceived by the parents, being due to study the causes and why parent's perception does not determine differences in dietary habits, physical activity and sedentary habits in their children.

  3. Spatially Resolved Imaging and Spectroscopy of Candidate Dual Active Galactic Nuclei

    Science.gov (United States)

    McGurk, R. C.; Max, C. E.; Medling, A. M.; Shields, G. A.; Comerford, J. M.

    2015-09-01

    When galaxies merge, both central supermassive black holes are immersed in a dense and chaotic environment. If there is sufficient gas in the nuclear regions, one expects to see close pairs of active galactic nuclei (AGNs), or dual AGNs, in a fraction of galaxy mergers. However, finding them remains a challenge. The presence of double-peaked [O iii] emission lines has been proposed as a technique to select dual AGNs efficiently. We studied a sample of double-peaked narrow [O iii] emitting AGNs from Sloan Digital Sky Survey (SDSS) DR7. By obtaining new and archival high spatial resolution images taken with the Keck II Laser Guide Star Adaptive Optics system and the near-infrared camera NIRC2, we show that 30% of 140 double-peaked [O iii] emission line SDSS AGNs have two spatial components within a 3″ radius. However, spatially resolved spectroscopy or X-ray observations are needed to confirm these galaxy pairs as systems containing two AGNs. We followed up three spatially double candidate dual AGNs with integral field spectroscopy from Keck OSIRIS and 10 candidates with long-slit spectroscopy from the Shane Kast Double Spectrograph at Lick Observatory. We find that the double-peaked emission lines in our sample of 12 candidates are caused by: one dual AGN (SDSS J114642.47+511029.6), one confirmed outflow and four likely outflows, two pairs of star-forming galaxies, one candidate indeterminate due to sky line interference, and three AGNs with spatially coincident double [O iii] peaks, likely due to unresolved complex narrow line kinematics, outflows, binary AGN, or small-scale jets.

  4. SPATIALLY RESOLVED IMAGING AND SPECTROSCOPY OF CANDIDATE DUAL ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    McGurk, R. C.; Max, C. E. [Astronomy Department and UCO-Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Medling, A. M. [Research School of Astronomy and Astrophysics, Australian National University, Mount Stromlo Observatory, Cotter Road, Weston Creek, ACT 2611 (Australia); Shields, G. A. [Laguna Falls Institute for Astrophysics, Austin, TX 78746 (United States); Comerford, J. M., E-mail: rosalie.mcgurk@gmail.com, E-mail: max@ucolick.org, E-mail: anne.medling@anu.edu.au, E-mail: shields@lfastro.org, E-mail: julie.comerford@colorado.edu [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

    2015-09-20

    When galaxies merge, both central supermassive black holes are immersed in a dense and chaotic environment. If there is sufficient gas in the nuclear regions, one expects to see close pairs of active galactic nuclei (AGNs), or dual AGNs, in a fraction of galaxy mergers. However, finding them remains a challenge. The presence of double-peaked [O iii] emission lines has been proposed as a technique to select dual AGNs efficiently. We studied a sample of double-peaked narrow [O iii] emitting AGNs from Sloan Digital Sky Survey (SDSS) DR7. By obtaining new and archival high spatial resolution images taken with the Keck II Laser Guide Star Adaptive Optics system and the near-infrared camera NIRC2, we show that 30% of 140 double-peaked [O iii] emission line SDSS AGNs have two spatial components within a 3″ radius. However, spatially resolved spectroscopy or X-ray observations are needed to confirm these galaxy pairs as systems containing two AGNs. We followed up three spatially double candidate dual AGNs with integral field spectroscopy from Keck OSIRIS and 10 candidates with long-slit spectroscopy from the Shane Kast Double Spectrograph at Lick Observatory. We find that the double-peaked emission lines in our sample of 12 candidates are caused by: one dual AGN (SDSS J114642.47+511029.6), one confirmed outflow and four likely outflows, two pairs of star-forming galaxies, one candidate indeterminate due to sky line interference, and three AGNs with spatially coincident double [O iii] peaks, likely due to unresolved complex narrow line kinematics, outflows, binary AGN, or small-scale jets.

  5. SPATIALLY RESOLVED IMAGING AND SPECTROSCOPY OF CANDIDATE DUAL ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    McGurk, R. C.; Max, C. E.; Medling, A. M.; Shields, G. A.; Comerford, J. M.

    2015-01-01

    When galaxies merge, both central supermassive black holes are immersed in a dense and chaotic environment. If there is sufficient gas in the nuclear regions, one expects to see close pairs of active galactic nuclei (AGNs), or dual AGNs, in a fraction of galaxy mergers. However, finding them remains a challenge. The presence of double-peaked [O iii] emission lines has been proposed as a technique to select dual AGNs efficiently. We studied a sample of double-peaked narrow [O iii] emitting AGNs from Sloan Digital Sky Survey (SDSS) DR7. By obtaining new and archival high spatial resolution images taken with the Keck II Laser Guide Star Adaptive Optics system and the near-infrared camera NIRC2, we show that 30% of 140 double-peaked [O iii] emission line SDSS AGNs have two spatial components within a 3″ radius. However, spatially resolved spectroscopy or X-ray observations are needed to confirm these galaxy pairs as systems containing two AGNs. We followed up three spatially double candidate dual AGNs with integral field spectroscopy from Keck OSIRIS and 10 candidates with long-slit spectroscopy from the Shane Kast Double Spectrograph at Lick Observatory. We find that the double-peaked emission lines in our sample of 12 candidates are caused by: one dual AGN (SDSS J114642.47+511029.6), one confirmed outflow and four likely outflows, two pairs of star-forming galaxies, one candidate indeterminate due to sky line interference, and three AGNs with spatially coincident double [O iii] peaks, likely due to unresolved complex narrow line kinematics, outflows, binary AGN, or small-scale jets

  6. Explaining Spatial Variation in Real Estate Development Activity in Turkey

    OpenAIRE

    Elif Alkay; Berna Keskin; Craig Watkins

    2015-01-01

    There is a strong policy discourse at local and national level in Turkey that ascribes considerable economic benefits to new construction activity. Critics, however, argue that this policy discourse has led to a mismatch between public policy and market fundamentals in many cities. It has been suggested that policy intentions might be driving construction levels above demand levels and could be contributing to uneven spatial development between regions. This paper seeks to shed light on this ...

  7. Seeing and Feeling for Self and Other: Proprioceptive Spatial Location Determines Multisensory Enhancement of Touch

    Science.gov (United States)

    Cardini, Flavia; Haggard, Patrick; Ladavas, Elisabetta

    2013-01-01

    We have investigated the relation between visuo-tactile interactions and the self-other distinction. In the Visual Enhancement of Touch (VET) effect, non-informative vision of one's own hand improves tactile spatial perception. Previous studies suggested that looking at "another"person's hand could also enhance tactile perception, but did not…

  8. Children's perceptions of weight, obesity, nutrition, physical activity and related health and socio-behavioural factors.

    Science.gov (United States)

    Economos, Christina D; Bakun, Peter J; Herzog, Julia Bloom; Dolan, Peter R; Lynskey, Vanessa M; Markow, Dana; Sharma, Shanti; Nelson, Miriam E

    2014-01-01

    Approximately one-third of children in the USA are either overweight or obese. Understanding the perceptions of children is an important factor in reversing this trend. An online survey was conducted with children to capture their perceptions of weight, overweight, nutrition, physical activity and related socio-behavioural factors. Within the USA. US children (n 1224) aged 8-18 years. Twenty-seven per cent of children reported being overweight; 47·1% of children overestimated the rate of overweight/obesity among US children. A higher percentage of self-classified overweight children (81·9%) worried about weight than did self-classified under/normal weight children (31·1%). Most children (91·1%) felt that it was important to not be overweight, for both health-related and social-related reasons. The majority of children believed that if someone their age is overweight they will likely be overweight in adulthood (93·1%); get an illness such as diabetes or heart disease in adulthood (90·2%); not be able to play sports well (84·5%); and be teased or made fun of in school (87·8%). Children focused more on food/drink than physical activity as reasons for overweight at their age. Self-classified overweight children were more likely to have spoken with someone about their weight over the last year than self-classified under/normal weight children. Children demonstrated good understanding of issues regarding weight, overweight, nutrition, physical activity and related socio-behavioural factors. Their perceptions are important and can be helpful in crafting solutions that will resonate with children.

  9. Improving children's physical self-perception through a school-based physical activity intervention

    DEFF Research Database (Denmark)

    Christiansen, Lars B.; Lund-Cramer, Pernille; Brondeel, Ruben

    2018-01-01

    Purpose Physical activity at school can improve the mental health of all children – especially if it targets children's developmental needs and is carried out in a positive social climate. The purpose of the present study was to examine the effect of a 9-month school intervention focusing......) PE lessons, 2) in-class activity outside PE, and 3) physical activity during break-time. It used a cluster-randomized design to select 24 Danish schools either for intervention or for control. Survey data on self-perception variables, socio-demographics and physical activity was collected prior...... on physical self-worth, self-perceived sport competence, body attractiveness, social competences and global self-worth in children aged 10–13 years. Methods Taking self-determination theory as its starting point, the intervention was developed and pilot-tested in close co-operation with schools. It targeted 1...

  10. Ambiguities and conventions in the perception of visual art.

    Science.gov (United States)

    Mamassian, Pascal

    2008-09-01

    Vision perception is ambiguous and visual arts play with these ambiguities. While perceptual ambiguities are resolved with prior constraints, artistic ambiguities are resolved by conventions. Is there a relationship between priors and conventions? This review surveys recent work related to these ambiguities in composition, spatial scale, illumination and color, three-dimensional layout, shape, and movement. While most conventions seem to have their roots in perceptual constraints, those conventions that differ from priors may help us appreciate how visual arts differ from everyday perception.

  11. Multiagent-Based Simulation of Temporal-Spatial Characteristics of Activity-Travel Patterns Using Interactive Reinforcement Learning

    Directory of Open Access Journals (Sweden)

    Min Yang

    2014-01-01

    Full Text Available We propose a multiagent-based reinforcement learning algorithm, in which the interactions between travelers and the environment are considered to simulate temporal-spatial characteristics of activity-travel patterns in a city. Road congestion degree is added to the reinforcement learning algorithm as a medium that passes the influence of one traveler’s decision to others. Meanwhile, the agents used in the algorithm are initialized from typical activity patterns extracted from the travel survey diary data of Shangyu city in China. In the simulation, both macroscopic activity-travel characteristics such as traffic flow spatial-temporal distribution and microscopic characteristics such as activity-travel schedules of each agent are obtained. Comparing the simulation results with the survey data, we find that deviation of the peak-hour traffic flow is less than 5%, while the correlation of the simulated versus survey location choice distribution is over 0.9.

  12. Perceptual asymmetry in texture perception.

    Science.gov (United States)

    Williams, D; Julesz, B

    1992-07-15

    A fundamental property of human visual perception is our ability to distinguish between textures. A concerted effort has been made to account for texture segregation in terms of linear spatial filter models and their nonlinear extensions. However, for certain texture pairs the ease of discrimination changes when the role of figure and ground are reversed. This asymmetry poses a problem for both linear and nonlinear models. We have isolated a property of texture perception that can account for this asymmetry in discrimination: subjective closure. This property, which is also responsible for visual illusions, appears to be explainable by early visual processes alone. Our results force a reexamination of the process of human texture segregation and of some recent models that were introduced to explain it.

  13. Audiovisual perception in amblyopia: A review and synthesis.

    Science.gov (United States)

    Richards, Michael D; Goltz, Herbert C; Wong, Agnes M F

    2018-05-17

    Amblyopia is a common developmental sensory disorder that has been extensively and systematically investigated as a unisensory visual impairment. However, its effects are increasingly recognized to extend beyond vision to the multisensory domain. Indeed, amblyopia is associated with altered cross-modal interactions in audiovisual temporal perception, audiovisual spatial perception, and audiovisual speech perception. Furthermore, although the visual impairment in amblyopia is typically unilateral, the multisensory abnormalities tend to persist even when viewing with both eyes. Knowledge of the extent and mechanisms of the audiovisual impairments in amblyopia, however, remains in its infancy. This work aims to review our current understanding of audiovisual processing and integration deficits in amblyopia, and considers the possible mechanisms underlying these abnormalities. Copyright © 2018. Published by Elsevier Ltd.

  14. Children's perceptions of their home and neighborhood environments, and their association with objectively measured physical activity: a qualitative and quantitative study.

    Science.gov (United States)

    Hume, C; Salmon, J; Ball, K

    2005-02-01

    Environmental factors may have an important influence on children's physical activity, yet children's perspectives of their home and neighborhood environments have not been widely assessed. The aim of this study was to investigate children's perceptions of their environments, and to examine associations between these perceptions and objectively measured physical activity. The sample consisted of 147, 10-year-old Australian children, who drew maps of their home and neighborhood environments. A subsample of children photographed places and things in these environments that were important to them. The maps were analyzed for themes, and for the frequency with which particular objects and locations appeared. Physical activity was objectively measured using accelerometers. Six themes emerged from the qualitative analysis of the maps and photographs: the family home; opportunities for physical activity and sedentary pursuits; food items and locations; green space and outside areas; the school and opportunities for social interaction. Of the 11 variables established from these themes, one home and two neighborhood factors were associated with children's physical activity. These findings contribute to a broader understanding of children's perceptions of their environment, and highlight the potential importance of the home and neighborhood environments for promoting physical activity behavior.

  15. Faculty and second-year medical student perceptions of active learning in an integrated curriculum.

    Science.gov (United States)

    Tsang, Alexander; Harris, David M

    2016-12-01

    Patients expect physicians to be lifelong learners who are able to interpret and evaluate diagnostic tests, and most medical schools list the development of lifelong learning in their program objectives. However, lecture is the most often utilized form of teaching in the first two years and is considered passive learning. The current generation of medical students has many characteristics that should support active learning pedagogies. The purpose of this study was to analyze student and faculty perceptions of active learning in an integrated medical curriculum at the second-year mark, where students have been exposed to multiple educational pedagogies. The first hypothesis of the study was that faculty would favor active learning methods. The second hypothesis was that Millennial medical students would favor active learning due to their characteristics. Primary faculty for years 1 and 2 and second-year medical students were recruited for an e-mail survey consisting of 12 questions about active learning and lecture. Students perceived that lecture and passive pedagogies were more effective for learning, whereas faculty felt active and collaborative learning was more effective. Students believed that more content should be covered by lecture than faculty. There were also significant differences in perceptions of what makes a good teacher. Students and faculty both felt that lack of time in the curriculum and preparation time were barriers for faculty. The data suggest that students are not familiar with the process of learning and that more time may be needed to help students develop lifelong learning skills. Copyright © 2016 The American Physiological Society.

  16. Competing sound sources reveal spatial effects in cortical processing.

    Directory of Open Access Journals (Sweden)

    Ross K Maddox

    Full Text Available Why is spatial tuning in auditory cortex weak, even though location is important to object recognition in natural settings? This question continues to vex neuroscientists focused on linking physiological results to auditory perception. Here we show that the spatial locations of simultaneous, competing sound sources dramatically influence how well neural spike trains recorded from the zebra finch field L (an analog of mammalian primary auditory cortex encode source identity. We find that the location of a birdsong played in quiet has little effect on the fidelity of the neural encoding of the song. However, when the song is presented along with a masker, spatial effects are pronounced. For each spatial configuration, a subset of neurons encodes song identity more robustly than others. As a result, competing sources from different locations dominate responses of different neural subpopulations, helping to separate neural responses into independent representations. These results help elucidate how cortical processing exploits spatial information to provide a substrate for selective spatial auditory attention.

  17. Geographic information systems, remote sensing, and spatial analysis activities in Texas, 2008-09

    Science.gov (United States)

    ,

    2009-01-01

    Geographic information system (GIS) technology has become an important tool for scientific investigation, resource management, and environmental planning. A GIS is a computer-aided system capable of collecting, storing, analyzing, and displaying spatially referenced digital data. GIS technology is useful for analyzing a wide variety of spatial data. Remote sensing involves collecting remotely sensed data, such as satellite imagery, aerial photography, or radar images, and analyzing the data to gather information or investigate trends about the environment or the Earth's surface. Spatial analysis combines remotely sensed, thematic, statistical, quantitative, and geographical data through overlay, modeling, and other analytical techniques to investigate specific research questions. It is the combination of data formats and analysis techniques that has made GIS an essential tool in scientific investigations. This fact sheet presents information about the technical capabilities and project activities of the U.S. Geological Survey (USGS) Texas Water Science Center (TWSC) GIS Workgroup during 2008 and 2009. After a summary of GIS Workgroup capabilities, brief descriptions of activities by project at the local and national levels are presented. Projects are grouped by the fiscal year (October-September 2008 or 2009) the project ends and include overviews, project images, and Internet links to additional project information and related publications or articles.

  18. Music Alters Visual Perception

    NARCIS (Netherlands)

    Jolij, Jacob; Meurs, Maaike

    2011-01-01

    Background: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e. g., memory) and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the

  19. Students’ Spatial Performance: Cognitive Style and Sex Differences

    Science.gov (United States)

    Hanifah, U.; Juniati, D.; Siswono, T. Y. E.

    2018-01-01

    This study aims at describing the students’ spatial abilities based on cognitive styles and sex differences. Spatial abilities in this study include 5 components, namely spatial perception, spatial visualization, mental rotation, spatial relations, and spatial orientation. This research is descriptive research with qualitative approach. The subjects in this research were 4 students of junior high school, there were 1 male FI, 1 male FD, 1 female FI, and 1 female FI. The results showed that there are differences in spatial abilities of the four subjects that are on the components of spatial visualization, mental rotation, and spatial relations. The differences in spatial abilities were found in methods / strategies used by each subject to solve each component problem. The differences in cognitive styles and sex suggested different choice of strategies used to solve problems. The male students imagined the figures but female students needed the media to solve the problem. Besides sex, the cognitive style differences also have an effect on solving a problem. In addition, FI students were not affected by distracting information but FD students could be affected by distracting information. This research was expected to contribute knowledge and insight to the readers, especially for math teachers in terms of the spatial ability of the students so that they can optimize their students’ spatial ability.

  20. Physical Activity and Self-Perceptions among Hong Kong Chinese with an Acquired Physical Disability

    Science.gov (United States)

    Sit, Cindy H. P.; Lau, Caren H. L.; Vertinsky, Patricia

    2009-01-01

    This study investigated the association between physical activity and self-perceptions such as body image, physical self-concept, and self-esteem among persons with an acquired physical disability in a non-Western population. Other personal variables such as gender and time of onset of disability were also examined. A convenience sample of 66 Hong…

  1. Sensory Entrainment Mechanisms in Auditory Perception: Neural Synchronization Cortico-Striatal Activation.

    Science.gov (United States)

    Sameiro-Barbosa, Catia M; Geiser, Eveline

    2016-01-01

    The auditory system displays modulations in sensitivity that can align with the temporal structure of the acoustic environment. This sensory entrainment can facilitate sensory perception and is particularly relevant for audition. Systems neuroscience is slowly uncovering the neural mechanisms underlying the behaviorally observed sensory entrainment effects in the human sensory system. The present article summarizes the prominent behavioral effects of sensory entrainment and reviews our current understanding of the neural basis of sensory entrainment, such as synchronized neural oscillations, and potentially, neural activation in the cortico-striatal system.

  2. Sensory Entrainment Mechanisms in Auditory Perception: Neural Synchronization Cortico-Striatal Activation

    Science.gov (United States)

    Sameiro-Barbosa, Catia M.; Geiser, Eveline

    2016-01-01

    The auditory system displays modulations in sensitivity that can align with the temporal structure of the acoustic environment. This sensory entrainment can facilitate sensory perception and is particularly relevant for audition. Systems neuroscience is slowly uncovering the neural mechanisms underlying the behaviorally observed sensory entrainment effects in the human sensory system. The present article summarizes the prominent behavioral effects of sensory entrainment and reviews our current understanding of the neural basis of sensory entrainment, such as synchronized neural oscillations, and potentially, neural activation in the cortico-striatal system. PMID:27559306

  3. Teacher’s Perception about the Use of E-Learning/Edmodo in Educational Activities

    Science.gov (United States)

    Yanti, H.; Setiawan, A.; Nurhabibah; Yannuar

    2018-02-01

    This study examined the perception of the teachers about the use of e- learning/Edmodo in their educational activities. The teachers consist of diverse subject. Their perceptions were investigated in terms of three aspects: effects of the use of this technology on their perceived motivation, the perceived usefulness and the perceived ease of use of this technology. Edmodo was set up a Learning Management System (LMS) in an online discussion group of subject. The study was conducted in descriptive method. The data were collected by using a questionnaire, interview, and documentation technique. The findings of the study indicated that the teachers perceived that e-learning/Edmodo is a useful and also easy to use technology. It was found out that the teachers are satisfied with advantages of the use of this new technology in their LMS.

  4. Relationships between spatial activities and scores on the mental rotation test as a function of sex.

    Science.gov (United States)

    Ginn, Sheryl R; Pickens, Stefanie J

    2005-06-01

    Previous results suggested that female college students' scores on the Mental Rotations Test might be related to their prior experience with spatial tasks. For example, women who played video games scored better on the test than their non-game-playing peers, whereas playing video games was not related to men's scores. The present study examined whether participation in different types of spatial activities would be related to women's performance on the Mental Rotations Test. 31 men and 59 women enrolled at a small, private church-affiliated university and majoring in art or music as well as students who participated in intercollegiate athletics completed the Mental Rotations Test. Women's scores on the Mental Rotations Test benefitted from experience with spatial activities; the more types of experience the women had, the better their scores. Thus women who were athletes, musicians, or artists scored better than those women who had no experience with these activities. The opposite results were found for the men. Efforts are currently underway to assess how length of experience and which types of experience are related to scores.

  5. On Alternative Approaches to 3D Image Perception: Monoscopic 3D Techniques

    Science.gov (United States)

    Blundell, Barry G.

    2015-06-01

    In the eighteenth century, techniques that enabled a strong sense of 3D perception to be experienced without recourse to binocular disparities (arising from the spatial separation of the eyes) underpinned the first significant commercial sales of 3D viewing devices and associated content. However following the advent of stereoscopic techniques in the nineteenth century, 3D image depiction has become inextricably linked to binocular parallax and outside the vision science and arts communities relatively little attention has been directed towards earlier approaches. Here we introduce relevant concepts and terminology and consider a number of techniques and optical devices that enable 3D perception to be experienced on the basis of planar images rendered from a single vantage point. Subsequently we allude to possible mechanisms for non-binocular parallax based 3D perception. Particular attention is given to reviewing areas likely to be thought-provoking to those involved in 3D display development, spatial visualization, HCI, and other related areas of interdisciplinary research.

  6. The perception of spatial layout in real and virtual worlds.

    Science.gov (United States)

    Arthur, E J; Hancock, P A; Chrysler, S T

    1997-01-01

    As human-machine interfaces grow more immersive and graphically-oriented, virtual environment systems become more prominent as the medium for human-machine communication. Often, virtual environments (VE) are built to provide exact metrical representations of existing or proposed physical spaces. However, it is not known how individuals develop representational models of these spaces in which they are immersed and how those models may be distorted with respect to both the virtual and real-world equivalents. To evaluate the process of model development, the present experiment examined participant's ability to reproduce a complex spatial layout of objects having experienced them previously under different viewing conditions. The layout consisted of nine common objects arranged on a flat plane. These objects could be viewed in a free binocular virtual condition, a free binocular real-world condition, and in a static monocular view of the real world. The first two allowed active exploration of the environment while the latter condition allowed the participant only a passive opportunity to observe from a single viewpoint. Viewing conditions were a between-subject variable with 10 participants randomly assigned to each condition. Performance was assessed using mapping accuracy and triadic comparisons of relative inter-object distances. Mapping results showed a significant effect of viewing condition where, interestingly, the static monocular condition was superior to both the active virtual and real binocular conditions. Results for the triadic comparisons showed a significant interaction for gender by viewing condition in which males were more accurate than females. These results suggest that the situation model resulting from interaction with a virtual environment was indistinguishable from interaction with real objects at least within the constraints of the present procedure.

  7. Object Persistence Enhances Spatial Navigation: A Case Study in Smartphone Vision Science.

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    Liverence, Brandon M; Scholl, Brian J

    2015-07-01

    Violations of spatiotemporal continuity disrupt performance in many tasks involving attention and working memory, but experiments on this topic have been limited to the study of moment-by-moment on-line perception, typically assessed by passive monitoring tasks. We tested whether persisting object representations also serve as underlying units of longer-term memory and active spatial navigation, using a novel paradigm inspired by the visual interfaces common to many smartphones. Participants used key presses to navigate through simple visual environments consisting of grids of icons (depicting real-world objects), only one of which was visible at a time through a static virtual window. Participants found target icons faster when navigation involved persistence cues (via sliding animations) than when persistence was disrupted (e.g., via temporally matched fading animations), with all transitions inspired by smartphone interfaces. Moreover, this difference occurred even after explicit memorization of the relevant information, which demonstrates that object persistence enhances spatial navigation in an automatic and irresistible fashion. © The Author(s) 2015.

  8. Percepts, not acoustic properties, are the units of auditory short-term memory.

    Science.gov (United States)

    Mathias, Samuel R; von Kriegstein, Katharina

    2014-04-01

    For decades, researchers have sought to understand the organizing principles of auditory and visual short-term memory (STM). Previous work in audition has suggested that there are independent memory stores for different sound features, but the nature of the representations retained within these stores is currently unclear. Do they retain perceptual features, or do they instead retain representations of the sound's specific acoustic properties? In the present study we addressed this question by measuring listeners' abilities to keep one of three acoustic properties (interaural time difference [ITD], interaural level difference [ILD], or frequency) in memory when the target sound was followed by interfering sounds that varied randomly in one of the same properties. Critically, ITD and ILD evoked the same percept (spatial location), despite being acoustically different and having different physiological correlates, whereas frequency evoked a different percept (pitch). The results showed that listeners found it difficult to remember the percept of spatial location when the interfering tones varied either in ITD or ILD, but not when they varied in frequency. The study demonstrates that percepts are the units of auditory STM, and provides testable predictions for future neuroscientific work on both auditory and visual STM.

  9. Implied motion language can influence visual spatial memory.

    Science.gov (United States)

    Vinson, David W; Engelen, Jan; Zwaan, Rolf A; Matlock, Teenie; Dale, Rick

    2017-07-01

    How do language and vision interact? Specifically, what impact can language have on visual processing, especially related to spatial memory? What are typically considered errors in visual processing, such as remembering the location of an object to be farther along its motion trajectory than it actually is, can be explained as perceptual achievements that are driven by our ability to anticipate future events. In two experiments, we tested whether the prior presentation of motion language influences visual spatial memory in ways that afford greater perceptual prediction. Experiment 1 showed that motion language influenced judgments for the spatial memory of an object beyond the known effects of implied motion present in the image itself. Experiment 2 replicated this finding. Our findings support a theory of perception as prediction.

  10. Body-Selective Areas in the Visual Cortex are less active in Children than in Adults

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    Paddy D Ross

    2014-11-01

    Full Text Available Our ability to read other people’s non-verbal signals gets refined throughout childhood and adolescence. How this is paralleled by brain development has been investigated mainly with regards to face perception, showing a protracted functional development of the face-selective visual cortical areas. In view of the importance of whole-body expressions in interpersonal communication it is important to understand the development of brain areas sensitive to these social signals.Here we used functional magnetic resonance imaging (fMRI to compare brain activity in a group of 24 children (age 6-11 and 26 adults while they passively watched short videos of body or object movements. We observed activity in similar regions in both groups; namely the extra-striate body area (EBA, fusiform body area (FBA, posterior superior temporal sulcus (pSTS, amygdala and premotor regions. Adults showed additional activity in the inferior frontal gyrus. Within the main body-selective regions (EBA, FBA and pSTS, the strength and spatial extent of fMRI signal change was larger in adults than in children. Multivariate Bayesian analysis showed that the spatial pattern of neural representation within those regions did not change over age.Our results indicate, for the first time, that body perception, like face perception, is still maturing through the second decade of life.

  11. Tinnitus perception and distress is related to abnormal spontaneous brain activity as measured by magnetoencephalography.

    Directory of Open Access Journals (Sweden)

    2005-06-01

    Full Text Available BACKGROUND: The neurophysiological mechanisms underlying tinnitus perception are not well understood. Surprisingly, there have been no group studies comparing abnormalities in ongoing, spontaneous neuronal activity in individuals with and without tinnitus perception. METHODS AND FINDINGS: Here, we show that the spontaneous neuronal activity of a group of individuals with tinnitus (n = 17 is characterised by a marked reduction in alpha (8-12 Hz power together with an enhancement in delta (1.5-4 Hz as compared to a normal hearing control group (n = 16. This pattern was especially pronounced for temporal regions. Moreover, correlations with tinnitus-related distress revealed strong associations with this abnormal spontaneous activity pattern, particularly in right temporal and left frontal areas. Overall, effects were stronger for the alpha than for the delta frequency band. A data stream of 5 min, recorded with a whole-head neuromagnetometer under a resting condition, was sufficient to extract the marked differences. CONCLUSIONS: Despite some limitations, there are arguments that the regional pattern of abnormal spontaneous activity we found could reflect a tinnitus-related cortical network. This finding, which suggests that a neurofeedback approach could reduce the adverse effects of this disturbing condition, could have important implications for the treatment of tinnitus.

  12. Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

    Directory of Open Access Journals (Sweden)

    Carlijn van den Boomen

    Full Text Available Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed in a higher spatial frequency (reference frequency: 6 cycles per degree discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135. Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28 punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be

  13. Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

    Science.gov (United States)

    van den Boomen, Carlijn; Peters, Judith Carolien

    2017-01-01

    Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed) in a higher spatial frequency (reference frequency: 6 cycles per degree) discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135). Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28) punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials) and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be used in future

  14. Imaging cortical activity following affective stimulation with a high temporal and spatial resolution

    Directory of Open Access Journals (Sweden)

    Catani Claudia

    2009-07-01

    Full Text Available Abstract Background The affective and motivational relevance of a stimulus has a distinct impact on cortical processing, particularly in sensory areas. However, the spatial and temporal dynamics of this affective modulation of brain activities remains unclear. The purpose of the present study was the development of a paradigm to investigate the affective modulation of cortical networks with a high temporal and spatial resolution. We assessed cortical activity with MEG using a visual steady-state paradigm with affective pictures. A combination of a complex demodulation procedure with a minimum norm estimation was applied to assess the temporal variation of the topography of cortical activity. Results Statistical permutation analyses of the results of the complex demodulation procedure revealed increased steady-state visual evoked field amplitudes over occipital areas following presentation of affective pictures compared to neutral pictures. This differentiation shifted in the time course from occipital regions to parietal and temporal regions. Conclusion It can be shown that stimulation with affective pictures leads to an enhanced activity in occipital region as compared to neutral pictures. However, the focus of differentiation is not stable over time but shifts into temporal and parietal regions within four seconds of stimulation. Thus, it can be crucial to carefully choose regions of interests and time intervals when analyzing the affective modulation of cortical activity.

  15. High spatial correspondence at a columnar level between activation and resting state fMRI signals and local field potentials.

    Science.gov (United States)

    Shi, Zhaoyue; Wu, Ruiqi; Yang, Pai-Feng; Wang, Feng; Wu, Tung-Lin; Mishra, Arabinda; Chen, Li Min; Gore, John C

    2017-05-16

    Although blood oxygenation level-dependent (BOLD) fMRI has been widely used to map brain responses to external stimuli and to delineate functional circuits at rest, the extent to which BOLD signals correlate spatially with underlying neuronal activity, the spatial relationships between stimulus-evoked BOLD activations and local correlations of BOLD signals in a resting state, and whether these spatial relationships vary across functionally distinct cortical areas are not known. To address these critical questions, we directly compared the spatial extents of stimulated activations and the local profiles of intervoxel resting state correlations for both high-resolution BOLD at 9.4 T and local field potentials (LFPs), using 98-channel microelectrode arrays, in functionally distinct primary somatosensory areas 3b and 1 in nonhuman primates. Anatomic images of LFP and BOLD were coregistered within 0.10 mm accuracy. We found that the point spread functions (PSFs) of BOLD and LFP responses were comparable in the stimulus condition, and both estimates of activations were slightly more spatially constrained than local correlations at rest. The magnitudes of stimulus responses in area 3b were stronger than those in area 1 and extended in a medial to lateral direction. In addition, the reproducibility and stability of stimulus-evoked activation locations within and across both modalities were robust. Our work suggests that the intrinsic resolution of BOLD is not a limiting feature in practice and approaches the intrinsic precision achievable by multielectrode electrophysiology.

  16. Aging and exercise: Perceptions of the active lived-body.

    Science.gov (United States)

    Fougner, Marit; Bergland, Astrid; Lund, Anne; Debesay, Jonas

    2018-03-30

    Exploring older people's evocation of their positive experiences of aging has been proposed as a counterweight to the Western stereotype of aging as a process of decline. The aim of this article is to explore how aging women, who participate regularly in group exercise classes, perceive their own bodies and the bodies of others. This article reports on the findings from interviews with 16 women between the age of 70 and 85. We analyzed the data using qualitative content analysis. Two overarching and interrelated themes concerning body perception emerged from the interviews: "The aging body and appearance" and "The body as subject and object." The binary discourse of old age, as either a decline or a success appears in our findings. The training contributes to a sense of well-being experienced through perceived increased physical abilities, self- image and self-esteem. Physical ability was perceived as being more important than appearance by the participants in this study, considering their preconception of an association between declining health, abilities, and older age. Involvement in physical activity appears to play a significant role in the perception of the women's own aging. Although physical attractiveness is a desirable outcome, the most important positive impact of the group exercise was related to increased social belonging and well-being, physical abilities, and capabilities. Thus implications for practice suggests that an intensive group training contributes to the opinion that an aging body is not necessarily a barrier to positive and successful aging.

  17. Perceptions of Physical Activity and Influences of Participation in Young African-American Adolescent Girls.

    Science.gov (United States)

    Morrison, Shannon; Knight, Candace; Crew-Gooden, Annette

    2015-12-01

    The purpose of this study was to explore African-American adolescent girls' perceptions of physical activity participation, examine how physical activity is defined and identify the most preferred forms of physical activity. Qualitative focus group interviews of a convenience sample (N = 30; Mean age = 14.3 years) were used to identifyfactors that influence African-American girls' physical activity participation as well as to explore how physical activity is defined within this population. Four themes emerged: (a) benefits and motivation to engage in physical activity, (b) behaviors consistent with perceived physical activity, (c) most enjoyable physical activity/activities, and (d) barriers to physical activity. Physical activities that promoted normative adolescent development (i.e., autonomy) were perceived as most beneficial, desirable, and most likely to be sustained. Implications of these findings highlight the importance of the incorporation of socialization and peer engagement in physical activity programs designed for African-American adolescent girls.

  18. The spatial comfort study of shophouse at Kampung Madras

    Science.gov (United States)

    Ginting, Y. U. U.; Ginting, N.; Zahrah, W.

    2018-03-01

    This Research comes from the increasing quantity of shophouse in downtown Medan and the suburban area. The condition of shophouse tend to have narrowly spaced rooms, the middle area of the house are poorly lighted, and lots of space left unused. This research is supported by many spatial issues from previous studies. This study is conducted to determine the level of comfort of shophouse as a function of living space and focused on the spatial aspect namely anthropometry, indoor space circulation, space requirement and function, spatial design and indoor visual. This study uses the descriptive method with the qualitative and quantitative approach. Data collection technique is done by field observation, questionnaire method is also used to get the respondent perception of the spatial comfort of a shophouse. The result indicates that the level of spatial comfort of the shophouse is an uncomfort. So the improvements in the circulation of access to the building, spatial design, lighting, and aeration are needed to improve the spatial comfort of a shophouse.

  19. Suppressive mechanisms in visual motion processing: From perception to intelligence.

    Science.gov (United States)

    Tadin, Duje

    2015-10-01

    Perception operates on an immense amount of incoming information that greatly exceeds the brain's processing capacity. Because of this fundamental limitation, the ability to suppress irrelevant information is a key determinant of perceptual efficiency. Here, I will review a series of studies investigating suppressive mechanisms in visual motion processing, namely perceptual suppression of large, background-like motions. These spatial suppression mechanisms are adaptive, operating only when sensory inputs are sufficiently robust to guarantee visibility. Converging correlational and causal evidence links these behavioral results with inhibitory center-surround mechanisms, namely those in cortical area MT. Spatial suppression is abnormally weak in several special populations, including the elderly and individuals with schizophrenia-a deficit that is evidenced by better-than-normal direction discriminations of large moving stimuli. Theoretical work shows that this abnormal weakening of spatial suppression should result in motion segregation deficits, but direct behavioral support of this hypothesis is lacking. Finally, I will argue that the ability to suppress information is a fundamental neural process that applies not only to perception but also to cognition in general. Supporting this argument, I will discuss recent research that shows individual differences in spatial suppression of motion signals strongly predict individual variations in IQ scores. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Parents' perceptions of their children's weight, eating habits, and physical activities at home and at school.

    Science.gov (United States)

    Jaballas, Elvira; Clark-Ott, Dorothy; Clasen, Carla; Stolfi, Adrienne; Urban, Marianne

    2011-01-01

    Parental perceptions of their young children's weight and habits may play an important role in determining whether children develop and maintain healthy lifestyles. This study was conducted to determine perceptions of parents of third-grade children in an urban school setting regarding their children's weight, eating habits, and physical activities. Parents anonymously completed surveys about their child's weight, eating habits, and daily activities. The survey also asked about how schools could encourage healthy eating and increased physical activity. Overall, 26% of the parents perceived their child to be overweight and expressed concern, but 40% of these parents believed that overweight is a condition that will be outgrown. Parents who reported eating more than eight meals per week with their child were less likely to report their child as overweight and more likely to believe that their child's physical activity level was appropriate. Most parents of third-grade students demonstrated concern regarding their child's weight and perceive obesity as a problem. Parents support school interventions such as nutrition education and fitness classes. Copyright © 2011 National Association of Pediatric Nurse Practitioners. Published by Mosby, Inc. All rights reserved.

  1. Perception of the Body in Space: Mechanisms

    Science.gov (United States)

    Young, Laurence R.

    1991-01-01

    The principal topic is the perception of body orientation and motion in space and the extent to which these perceptual abstraction can be related directly to the knowledge of sensory mechanisms, particularly for the vestibular apparatus. Spatial orientation is firmly based on the underlying sensory mechanisms and their central integration. For some of the simplest situations, like rotation about a vertical axis in darkness, the dynamic response of the semicircular canals furnishes almost enough information to explain the sensations of turning and stopping. For more complex conditions involving multiple sensory systems and possible conflicts among their messages, a mechanistic response requires significant speculative assumptions. The models that exist for multisensory spatial orientation are still largely of the non-rational parameter variety. They are capable of predicting relationships among input motions and output perceptions of motion, but they involve computational functions that do not now and perhaps never will have their counterpart in central nervous system machinery. The challenge continues to be in the iterative process of testing models by experiment, correcting them where necessary, and testing them again.

  2. Visceral perceptions and gastric myoelectrical activity in healthy women and in patients with bulimia nervosa.

    Science.gov (United States)

    Koch, K L; Bingaman, S; Tan, L; Stern, R M

    1998-02-01

    Bulimia nervosa remains a common eating disorder in young women. Little is known about upper gastrointestinal symptoms or gastric motility in patients with bulimia nervosa. The aim of this study was to measure gastric myoelectrical activity and hunger/satiety and stomach emptiness/fullness before and after a non-nutrient water load and solid-phase gastric emptying in hospitalized patients with bulimia nervosa (n = 12) and in healthy women (n = 13). Gastric myoelectrical activity was measured by means of cutaneous electrodes; visual analogue scales were used to measure perceptions of hunger/satiety and stomach emptiness/fullness. Before and after a standard water load the bulimia patients reported significantly greater stomach fullness and satiety compared with control subjects (P scrambled eggs showed the lag phase was shortened in the bulimic patients (16 +/- 4 min vs 31 +/- 4 min in controls, P < 0.01), but the percentage of meal emptied at 2 h was similar to control values. bulimia patients had exaggerated perceptions of stomach fullness and satiety in response to water; and abnormal gastric myoelectrical activity and accelerated lag phase of gastric emptying were objective stomach abnormalities detected in hospitalized patients with bulimia nervosa.

  3. Active and passive spatial learning in human navigation: acquisition of graph knowledge.

    Science.gov (United States)

    Chrastil, Elizabeth R; Warren, William H

    2015-07-01

    It is known that active exploration of a new environment leads to better spatial learning than does passive visual exposure. We ask whether specific components of active learning differentially contribute to particular forms of spatial knowledge-the exploration-specific learning hypothesis. Previously, we found that idiothetic information during walking is the primary active contributor to metric survey knowledge (Chrastil & Warren, 2013). In this study, we test the contributions of 3 components to topological graph and route knowledge: visual information, idiothetic information, and cognitive decision making. Four groups of participants learned the locations of 8 objects in a virtual hedge maze by (a) walking or (b) watching a video, crossed with (1) either making decisions about their path or (2) being guided through the maze. Route and graph knowledge were assessed by walking in the maze corridors from a starting object to the remembered location of a test object, with frequent detours. Decision making during exploration significantly contributed to subsequent route finding in the walking condition, whereas idiothetic information did not. Participants took novel routes and the metrically shortest routes on the majority of both direct and barrier trials, indicating that labeled graph knowledge-not merely route knowledge-was acquired. We conclude that, consistent with the exploration-specific learning hypothesis, decision making is the primary component of active learning for the acquisition of topological graph knowledge, whereas idiothetic information is the primary component for metric survey knowledge. (c) 2015 APA, all rights reserved.

  4. Feature-based attentional modulation of orientation perception in somatosensation

    Directory of Open Access Journals (Sweden)

    Meike Annika Schweisfurth

    2014-07-01

    Full Text Available In a reaction time study of human tactile orientation detection the effects of spatial attention and feature-based attention were investigated. Subjects had to give speeded responses to target orientations (parallel and orthogonal to the finger axis in a random stream of oblique tactile distractor orientations presented to their index and ring fingers. Before each block of trials, subjects received a tactile cue at one finger. By manipulating the validity of this cue with respect to its location and orientation (feature, we provided an incentive to subjects to attend spatially to the cued location and only there to the cued orientation. Subjects showed quicker responses to parallel compared to orthogonal targets, pointing to an orientation anisotropy in sensory processing. Also, faster reaction times were observed in location-matched trials, i.e. when targets appeared on the cued finger, representing a perceptual benefit of spatial attention. Most importantly, reaction times were shorter to orientations matching the cue, both at the cued and at the uncued location, documenting a global enhancement of tactile sensation by feature-based attention. This is the first report of a perceptual benefit of feature-based attention outside the spatial focus of attention in somatosensory perception. The similarity to effects of feature-based attention in visual perception supports the notion of matching attentional mechanisms across sensory domains.

  5. Towards a fourth spatial dimension of brain activity.

    Science.gov (United States)

    Tozzi, Arturo; Peters, James F

    2016-06-01

    Current advances in neurosciences deal with the functional architecture of the central nervous system, paving the way for general theories that improve our understanding of brain activity. From topology, a strong concept comes into play in understanding brain functions, namely, the 4D space of a "hypersphere's torus", undetectable by observers living in a 3D world. The torus may be compared with a video game with biplanes in aerial combat: when a biplane flies off one edge of gaming display, it does not crash but rather it comes back from the opposite edge of the screen. Our thoughts exhibit similar behaviour, i.e. the unique ability to connect past, present and future events in a single, coherent picture as if we were allowed to watch the three screens of past-present-future "glued" together in a mental kaleidoscope. Here we hypothesize that brain functions are embedded in a imperceptible fourth spatial dimension and propose a method to empirically assess its presence. Neuroimaging fMRI series can be evaluated, looking for the topological hallmark of the presence of a fourth dimension. Indeed, there is a typical feature which reveal the existence of a functional hypersphere: the simultaneous activation of areas opposite each other on the 3D cortical surface. Our suggestion-substantiated by recent findings-that brain activity takes place on a closed, donut-like trajectory helps to solve long-standing mysteries concerning our psychological activities, such as mind-wandering, memory retrieval, consciousness and dreaming state.

  6. Direct Evidence for the Economy of Action: Glucose and the Perception of Geographical Slant

    Science.gov (United States)

    Schnall, Simone; Zadra, Jonathan R.; Proffitt, Dennis R.

    2012-01-01

    When locomoting in a physically challenging environment, the body draws upon available energy reserves to accommodate increased metabolic demand. Ingested glucose supplements the body’s energy resources, whereas non-caloric sweetener does not. Two experiments demonstrate that participants who had consumed a glucose-containing drink perceived a hills slant to be less steep than did participants who had consumed a drink containing non-caloric sweetener. The glucose manipulation influenced participants’ explicit awareness of hill slant but, as predicted, it did not affect a visually-guided action of orienting a tilting palmboard to be parallel to the hill. Measured individual differences in factors related to bioenergetic state such as fatigue, sleep quality, fitness, mood, and stress also affected perception such that lower energetic states were associated with steeper perceptions of hill slant. This research shows that the perception of the environment’s spatial layout is influenced by the energetic resources available for locomotion within it. Our findings are consistent with the view that spatial perceptions are influenced by bioenergetic factors. PMID:20514996

  7. Phantom auditory perception (tinnitus): mechanisms of generation and perception.

    Science.gov (United States)

    Jastreboff, P J

    1990-08-01

    Phantom auditory perception--tinnitus--is a symptom of many pathologies. Although there are a number of theories postulating certain mechanisms of its generation, none have been proven yet. This paper analyses the phenomenon of tinnitus from the point of view of general neurophysiology. Existing theories and their extrapolation are presented, together with some new potential mechanisms of tinnitus generation, encompassing the involvement of calcium and calcium channels in cochlear function, with implications for malfunction and aging of the auditory and vestibular systems. It is hypothesized that most tinnitus results from the perception of abnormal activity, defined as activity which cannot be induced by any combination of external sounds. Moreover, it is hypothesized that signal recognition and classification circuits, working on holographic or neuronal network-like representation, are involved in the perception of tinnitus and are subject to plastic modification. Furthermore, it is proposed that all levels of the nervous system, to varying degrees, are involved in tinnitus manifestation. These concepts are used to unravel the inexplicable, unique features of tinnitus and its masking. Some clinical implications of these theories are suggested.

  8. Earthworm activities in cassava and egusi melon fields in the transitional zone of Benin: linking farmers' perceptions with field studies

    NARCIS (Netherlands)

    Saïdou, A.; Kossou, D.; Brussaard, L.; Richards, P.; Kuyper, T.W.

    2008-01-01

    Farmers' perceptions of earthworm activities were studied in the transitional zone of Benin and linked to scientific explanations of earthworm casting activities. Earthworm activity was assessed in farmers' fields with three different cassava cultivars and in a field experiment with three different

  9. Neighbourhood social trust and youth perceptions of safety during daily activities.

    Science.gov (United States)

    Flynn, Kalen; Richmond, Therese S; Branas, Charles C; Wiebe, Douglas J

    2017-10-07

    Exposure to adverse neighbourhood conditions can negatively impact adolescent well-being and perceived safety. However, the impact of neighbourhood social trust on perceived safety is largely unknown. We studied 139 adolescent men to investigate how their perceptions of safety varied as a function of social trust levels in the neighbourhoods they traversed; neighbourhoods that were not necessarily their own. Adolescents mapped their minute-by-minute activities over a recent day and rated their perceived safety on a 10-point scale during in-person interviews. Neighbourhood social trust was measured via a citywide random sample survey. Mixed effects regression showed that, compared with their safety perceptions when in areas of low social trust, older adolescents were 73% more likely to feel unsafe when in areas of medium social trust, and 89% more likely to feel unsafe when in areas of high social trust. Inverse relationships between neighbourhood social trust and adolescents' perceived safety highlight the complex interplay between youth, environmental contexts and safety. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. SOCIO-SPATIAL INTEGRATION OF LANDSCAPE BACK LANE OF HOUSING AT BANDAR BARU NILAI: PRIVACY AND COMMUNITY

    Directory of Open Access Journals (Sweden)

    SITI F. M. LIAS

    2016-05-01

    Full Text Available Urban informal spaces in the form of back lane tend to promote socio-spatial integration between neighbourhood communities. The Back Lane Planning Design Guidelines issued in 2014 by Town and Country Planning Department of Malaysia identified back lane as such a place to encourage communal lifestyle whereas an area of owns residents privacy. In reality, back lane portrays as the wasted unfavourable paths thus several social concerns of safety, security, health issues as well as invading privacy and sense of deficiency community bonding issues arise. This study quantitatively analyses dwellers perception focusing to level of visual privacy and level of spiritual neighbourhood interaction towards effectiveness of newly landscape back lane (LBL in contemporary urban dwellings. Comparison of socio-spatial integration between two types of back lane design in grid-linear housing scheme ; the pleasing greenery landscape back lane (LBL and the plain empty bare paved back lane (PBL in residential area of Kota Seriemas, Nilai, Negeri Sembilan . Structured questionnaire distributed to 115 respondents to assess on privacy and comfort level, neighbourhood activities and communal lifestyle, back -lane usage, resident’s perception and expectation.The study proved the landscape design back lane (LBL is ensuring own right privacy lacking in promoting community interaction among the residents due to contemporary urban lifestyles.

  11. Maternal immune activation in rats produces temporal perception impairments in adult offspring analogous to those observed in schizophrenia.

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    Ashley R Deane

    Full Text Available The neurophysiology underlying temporal perception significantly overlaps with areas of dysfunction identified in schizophrenia. Patients commonly exhibit distorted temporal perception, which likely contributes to functional impairments. Thus, study of temporal perception in animal models of the disease may help to understand both cognitive and neurobiological factors involved in functional impairments in patients. As maternal immune activation (MIA has been shown to be a significant etiological risk factor in development of schizophrenia and other developmental psychiatric diseases, we tested interval timing in a rat model of MIA that has previously been shown to recapitulate several behavioural and neurophysiological impairments observed in the disease. Rats were tested on a temporal-bisection task, in which temporal duration stimuli were categorized as either "short" or "long" by responding to a corresponding lever. Data from this task were modeled to provide estimates of accuracy and sensitivity of temporal perception. Parameter estimates derived from the model fitting showed that MIA rats significantly overestimated the passage of time compared to controls. These results indicate that the MIA rat paradigm recapitulates timing distortions that are phenotypical of schizophrenia. These findings lend further support to the epidemiological validity of this MIA rat model, supporting its relevance for future research into the role of maternal immune activation in producing neurobiological and behavioural impairments in schizophrenia.

  12. Active sensing associated with spatial learning reveals memory-based attention in an electric fish.

    Science.gov (United States)

    Jun, James J; Longtin, André; Maler, Leonard

    2016-05-01

    Active sensing behaviors reveal what an animal is attending to and how it changes with learning. Gymnotus sp, a gymnotiform weakly electric fish, generates an electric organ discharge (EOD) as discrete pulses to actively sense its surroundings. We monitored freely behaving gymnotid fish in a large dark "maze" and extracted their trajectories and EOD pulse pattern and rate while they learned to find food with electrically detectable landmarks as cues. After training, they more rapidly found food using shorter, more stereotyped trajectories and spent more time near the food location. We observed three forms of active sensing: sustained high EOD rates per unit distance (sampling density), transient large increases in EOD rate (E-scans) and stereotyped scanning movements (B-scans) were initially strong at landmarks and food, but, after learning, intensified only at the food location. During probe (no food) trials, after learning, the fish's search area and intense active sampling was still centered on the missing food location, but now also increased near landmarks. We hypothesize that active sensing is a behavioral manifestation of attention and essential for spatial learning; the fish use spatial memory of landmarks and path integration to reach the expected food location and confine their attention to this region. Copyright © 2016 the American Physiological Society.

  13. Past and future effects of climate change on spatially heterogeneous vegetation activity in China

    Science.gov (United States)

    Gao, Jiangbo; Jiao, Kewei; Wu, Shaohong; Ma, Danyang; Zhao, Dongsheng; Yin, Yunhe; Dai, Erfu

    2017-07-01

    Climate change is a major driver of vegetation activity but its complex ecological relationships impede research efforts. In this study, the spatial distribution and dynamic characteristics of climate change effects on vegetation activity in China from the 1980s to the 2010s and from 2021 to 2050 were investigated using a geographically weighted regression (GWR) model. The GWR model was based on combined datasets of satellite vegetation index, climate observation and projection, and future vegetation productivity simulation. Our results revealed that the significantly positive precipitation-vegetation relationship was and will be mostly distributed in North China. However, the regions with temperature-dominated distribution of vegetation activity were and will be mainly located in South China. Due to the varying climate features and vegetation cover, the spatial correlation between vegetation activity and climate change may be altered. There will be different dominant climatic factors for vegetation activity distribution in some regions such as Northwest China, and even opposite correlations in Northeast China. Additionally, the response of vegetation activity to precipitation will move southward in the next three decades. In contrast, although the high warming rate will restrain the vegetation activity, precipitation variability could modify hydrothermal conditions for vegetation activity. This observation is exemplified in the projected future enhancement of vegetation activity in the Tibetan Plateau and weakened vegetation activity in East and Middle China. Furthermore, the vegetation in most parts of North China may adapt to an arid environment, whereas in many southern areas, vegetation will be repressed by water shortage in the future.

  14. Abstract spatial concept priming dynamically influences real-world actions

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    Sarah M Tower-Richardi

    2012-09-01

    Full Text Available Experienced regularities in our perceptions and actions play important roles in grounding abstract concepts such as social status, time, and emotion. Might we similarly ground abstract spatial concepts in more experienced-based domains? The present experiment explores this possibility by implicitly priming abstract spatial terms (north, south, east, west and then measuring participants’ hand movement trajectories while they respond to a body-referenced spatial target (up, down, left, right in a verbal (Exp. 1 or spatial (Exp. 2 format. Results from two experiments demonstrate temporally-dynamic and prime-biased movement trajectories when the primes are incongruent with the targets (e.g., north – left, west – up. That is, priming abstract coordinate directions influences subsequent actions in response to concrete target directions. These findings provide the first evidence that abstract concepts of world-centered coordinate axes are implicitly understood in the context of concrete body-referenced axes; critically, this abstract-concrete relationship manifests in motor movements, and may have implications for spatial memory organization.

  15. Spatial representation of organic carbon and active-layer thickness of high latitude soils in CMIP5 earth system models

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Umakant; Drewniak, Beth; Jastrow, Julie D.; Matamala, Roser M.; Vitharana, U. W. A.

    2017-08-01

    Soil properties such as soil organic carbon (SOC) stocks and active-layer thickness are used in earth system models (F.SMs) to predict anthropogenic and climatic impacts on soil carbon dynamics, future changes in atmospheric greenhouse gas concentrations, and associated climate changes in the permafrost regions. Accurate representation of spatial and vertical distribution of these soil properties in ESMs is a prerequisite for redudng existing uncertainty in predicting carbon-climate feedbacks. We compared the spatial representation of SOC stocks and active-layer thicknesses predicted by the coupled Modellntercomparison Project Phase 5 { CMIP5) ESMs with those predicted from geospatial predictions, based on observation data for the state of Alaska, USA. For the geospatial modeling. we used soil profile observations {585 for SOC stocks and 153 for active-layer thickness) and environmental variables (climate, topography, land cover, and surficial geology types) and generated fine-resolution (50-m spatial resolution) predictions of SOC stocks (to 1-m depth) and active-layer thickness across Alaska. We found large inter-quartile range (2.5-5.5 m) in predicted active-layer thickness of CMIP5 modeled results and small inter-quartile range (11.5-22 kg m-2) in predicted SOC stocks. The spatial coefficient of variability of active-layer thickness and SOC stocks were lower in CMIP5 predictions compared to our geospatial estimates when gridded at similar spatial resolutions (24.7 compared to 30% and 29 compared to 38%, respectively). However, prediction errors. when calculated for independent validation sites, were several times larger in ESM predictions compared to geospatial predictions. Primaly factors leading to observed differences were ( 1) lack of spatial heterogeneity in ESM predictions, (2) differences in assumptions concerning environmental controls, and (3) the absence of pedogenic processes in ESM model structures. Our results suggest that efforts to incorporate

  16. Parental and Adolescent Perceptions of Neighborhood Safety Related to Adolescents' Physical Activity in Their Neighborhood

    Science.gov (United States)

    Esteban-Cornejo, Irene; Carlson, Jordan A.; Conway, Terry L.; Cain, Kelli L.; Saelens, Brian E.; Frank, Lawrence D.; Glanz, Karen; Roman, Caterina G.; Sallis, James F.

    2016-01-01

    Purpose: The purpose of this study was to examine the association between adolescent and parental perceptions of neighborhood safety and adolescents' physical activity in multiple locations and to investigate the moderating effect of sex within this association. Method: This cross-sectional study was conducted with 928 adolescents aged 12 to 16…

  17. Effectiveness and student perceptions of an active learning activity using a headline news story to enhance in-class learning of cell cycle regulation.

    Science.gov (United States)

    Dirks-Naylor, Amie J

    2016-06-01

    An active learning activity was used to engage students and enhance in-class learning of cell cycle regulation in a PharmD level integrated biological sciences course. The aim of the present study was to determine the effectiveness and perception of the in-class activity. After completion of a lecture on the topic of cell cycle regulation, students completed a 10-question multiple-choice quiz before and after engaging in the activity. The activity involved reading of a headline news article published by ScienceDaily.com entitled "One Gene Lost Equals One limb Regained." The name of the gene was deleted from the article and, thus, the end goal of the activity was to determine the gene of interest by the description in the story. The activity included compiling a list of all potential gene candidates before sufficient information was given to identify the gene of interest (p21). A survey was completed to determine student perceptions of the activity. Quiz scores improved by an average of 20% after the activity (40.1 ± 1.95 vs. 59.9 ± 2.14,Pactivity, found the news article interesting, and believed that the activity improved their understanding of cell cycle regulation. The majority of students agreed that the in-class activity piqued their interest for learning the subject matter and also agreed that if they understand a concept during class, they are more likely to want to study that concept outside of class. In conclusion, the activity improved in-class understanding and enhanced interest in cell cycle regulation. Copyright © 2016 The American Physiological Society.

  18. Changes in physical activity, physical fitness, self-perception and quality of life following a 6-month physical activity counseling and cognitive behavioral therapy program in outpatients with binge eating disorder.

    Science.gov (United States)

    Vancampfort, Davy; Probst, Michel; Adriaens, An; Pieters, Guido; De Hert, Marc; Stubbs, Brendon; Soundy, Andy; Vanderlinden, Johan

    2014-10-30

    The aim of the current study was to explore the associations between changes in the number of binges, physical activity participation, physical fitness, physical self-perception and quality of life following a 6-month physical activity counseling and cognitive behavioral program in patients with binge eating disorder (BED). In total 34 (31 women) outpatients with BED (38.5±10.7 years) completed a 6-month 1-day per week group-based program. Participants completed the 36-item Short Form Health Survey, the Baecke Physical Activity questionnaire, the Physical Self Perception Profile and performed a 6-min walk test (6MWT) at baseline, after 3 and 6 months. Except for physical activity at work, physical strength and self-worth perception, all parameters significantly improved after 6 months. The effect sizes ranged from -0.33 for the number of binges to 1.67 for participation in sports activities. Significant increases in leisure time physical activity were associated with significant improvements in physical health related quality of life, perceived sports competence and physical fitness and in perceived body attractiveness. The significant reduction in the number of binges was associated with significant improvements in physical health related quality of life. Future research should focus on detailing which techniques can stimulate physical activity participation in patients with BED. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Tunnel vision: sharper gradient of spatial attention in autism.

    Science.gov (United States)

    Robertson, Caroline E; Kravitz, Dwight J; Freyberg, Jan; Baron-Cohen, Simon; Baker, Chris I

    2013-04-17

    Enhanced perception of detail has long been regarded a hallmark of autism spectrum conditions (ASC), but its origins are unknown. Normal sensitivity on all fundamental perceptual measures-visual acuity, contrast discrimination, and flicker detection-is strongly established in the literature. If individuals with ASC do not have superior low-level vision, how is perception of detail enhanced? We argue that this apparent paradox can be resolved by considering visual attention, which is known to enhance basic visual sensitivity, resulting in greater acuity and lower contrast thresholds. Here, we demonstrate that the focus of attention and concomitant enhancement of perception are sharper in human individuals with ASC than in matched controls. Using a simple visual acuity task embedded in a standard cueing paradigm, we mapped the spatial and temporal gradients of attentional enhancement by varying the distance and onset time of visual targets relative to an exogenous cue, which obligatorily captures attention. Individuals with ASC demonstrated a greater fall-off in performance with distance from the cue than controls, indicating a sharper spatial gradient of attention. Further, this sharpness was highly correlated with the severity of autistic symptoms in ASC, as well as autistic traits across both ASC and control groups. These findings establish the presence of a form of "tunnel vision" in ASC, with far-reaching implications for our understanding of the social and neurobiological aspects of autism.

  20. The spatial impact of neighbouring on the exports activities of COMESA countries by using spatial panel models

    Science.gov (United States)

    Hamzalouh, L.; Ismail, M. T.; Rahman, R. A.

    2017-09-01

    In this paper, spatial panel models were used and the method for selecting the best model amongst the spatial fixed effects model and the spatial random effects model to estimate the fitting model by using the robust Hausman test for analysis of the exports pattern of the Common Market for Eastern and Southern African (COMESA) countries. And examine the effects of the interactions of the economic statistic of explanatory variables on the exports of the COMESA. Results indicated that the spatial Durbin model with fixed effects specification should be tested and considered in most cases of this study. After that, the direct and indirect effects among COMESA regions were assessed, and the role of indirect spatial effects in estimating exports was empirically demonstrated. Regarding originality and research value, and to the best of the authors’ knowledge, this is the first attempt to examine exports between COMESA and its member countries through spatial panel models using XSMLE, which is a new command for spatial analysis using STATA.

  1. Dose Response Association between Physical Activity and Biological, Demographic, and Perceptions of Health Variables

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    Paul D. Loprinzi

    2013-08-01

    Full Text Available Background: Few population-based studies have examined the association between physical activity (PA and cardiovascular disease risk factors, demographic variables, and perceptions of health status, and we do not have a clear understanding of the dose-response relationship among these variables. Methods: Data from the 2003-2006 National Health and Nutrition Examination Survey was used to examine the dose-response relationship between objectively measured PA and metabolic syndrome (and its individual cardiovascular disease risk factors, demographic variables, and perceptions of health. After exclusions, 5,538 participants 18 years or older were included in the present study, with 2,538 participants providing fasting glucose and 2,527 providing fasting triglyceride data. PA was categorized into deciles. Results: Overall, the health benefits showed a general pattern of increase with each increasing levels of PA. Of the ten PA classifications examined, participants in the highest moderate-to-vigorous physical activity (MVPA category (at least 71 min/day had the lowest odds of developing metabolic syndrome. Conclusion: At a minimum, sedentary adults should strive to meet current PA guidelines (i.e., 150 min/week of MVPA, with additional positive benefits associated with engaging in three times this level of PA.

  2. Chinese Tourists’ Perceptions of Climate Change and Mitigation Behavior: An Application of Norm Activation Theory

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    Guiqiang Qiao

    2017-07-01

    Full Text Available It is well recognized that tourism development is a prominent contributor to climate change, but is also a “victim” of climate change. Therefore, to mitigate climate change is of great importance for the sustainability of tourism. Yet extant studies regarding tourism and climate change tend to be dominated by a supply-side stance, albeit the core role of the tourist in the tourism industry. While researchers are increasingly adopting a tourist perspective, few seek to understand the linkage between climate change and tourists’ specific mitigation behaviors in a tourism context; this is especially so in China. This study investigates the impact of Chinese tourists’ perceptions of climate change on their mitigation behaviors based on norm activation theory. Drawing on 557 self-administrated questionnaires collected in China, it finds that tourists’ perceptions of climate change and perceived contribution of tourism to climate change both positively affect energy saving and carbon reduction behavior in tourism. Yet, compared with perceived contribution of tourism to climate change, tourists’ perceptions of climate change are found to be a much stronger predictor for energy saving and carbon reduction behavior. Therefore, it suggests that tourists’ perceptions of climate change in a general context is more strongly related to climate change mitigation behavior in tourism, calling for attention to go beyond the tourism context to alleviate the negative impacts of tourism on climate change.

  3. Perception of illusory contour figures: Microgenetic analysis

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    Gvozdenović Vasilije P.

    2004-01-01

    Full Text Available Microgenetic analysis was used to investigate perception of illusory contour figures which represent whole, completed forms on the basis of segmented, incomplete stimulation. The analysis provided an experimental approach to this phenomenon which was standardly investigated phenomenologically. Experimental procedure consisted of two phases: a priming phase and b test phase which consisted of visual search task. Two types of visual search tasks were applied: (i classic detection, in which subjects were detecting presence or absence of the target stimuli and (ii two-alternative forced choice, 2AFC, in which subjects performed discrimination between two concurrent targets (target A vs. target B. Variation of exposition of prim stimuli was used as an indication of the percept formation period. Concepts like early vision, visual attention and feature binding were investigated. Four experiments were conducted. Their outcome showed that (i perception of amodal figure requires visual attention, (ii features binding precedes spatial attention and (iii time period of percept formation is dependent of task properties and varies between 50 - 150 ms. Some results obtained in this research could be explained by feature-integration theory (Treisman & Gelade, 1980; Treisman, 1986. Furthermore, percept formation period data comply with data acquired in Elliott & Müller's psychophysical research (1998.

  4. Inducible Knockout of the Cyclin-Dependent Kinase 5 Activator p35 Alters Hippocampal Spatial Coding and Neuronal Excitability

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    Eriko Kamiki

    2018-05-01

    Full Text Available p35 is an activating co-factor of Cyclin-dependent kinase 5 (Cdk5, a protein whose dysfunction has been implicated in a wide-range of neurological disorders including cognitive impairment and disease. Inducible deletion of the p35 gene in adult mice results in profound deficits in hippocampal-dependent spatial learning and synaptic physiology, however the impact of the loss of p35 function on hippocampal in vivo physiology and spatial coding remains unknown. Here, we recorded CA1 pyramidal cell activity in freely behaving p35 cKO and control mice and found that place cells in the mutant mice have elevated firing rates and impaired spatial coding, accompanied by changes in the temporal organization of spiking both during exploration and rest. These data shed light on the role of p35 in maintaining cellular and network excitability and provide a physiological correlate of the spatial learning deficits in these mice.

  5. Inducible Knockout of the Cyclin-Dependent Kinase 5 Activator p35 Alters Hippocampal Spatial Coding and Neuronal Excitability

    Science.gov (United States)

    Kamiki, Eriko; Boehringer, Roman; Polygalov, Denis; Ohshima, Toshio; McHugh, Thomas J.

    2018-01-01

    p35 is an activating co-factor of Cyclin-dependent kinase 5 (Cdk5), a protein whose dysfunction has been implicated in a wide-range of neurological disorders including cognitive impairment and disease. Inducible deletion of the p35 gene in adult mice results in profound deficits in hippocampal-dependent spatial learning and synaptic physiology, however the impact of the loss of p35 function on hippocampal in vivo physiology and spatial coding remains unknown. Here, we recorded CA1 pyramidal cell activity in freely behaving p35 cKO and control mice and found that place cells in the mutant mice have elevated firing rates and impaired spatial coding, accompanied by changes in the temporal organization of spiking both during exploration and rest. These data shed light on the role of p35 in maintaining cellular and network excitability and provide a physiological correlate of the spatial learning deficits in these mice. PMID:29867369

  6. Time Perception and Psychiatric Disorders

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    Hatice Ceviz

    2013-09-01

    Full Text Available Time perception is an ability which we use in every moment of daily life, that guides the formation and continuation of our behaviors and from an evolutionary perspective ensures survival. Internal clock models help us to understand time perception. Time perception is known to vary between individuals and particular situations. This variability is explained with the mechanisms which is associated with the processes related to attention, the speed of the internal clock and the memory unit. It is suggested that time perception is mainly associated with the activities of dopamine and acetylcholine. Some dopaminergic psychoactive substances like cocaine and amphetamine have all been shown to change time perception by increasing the speed of internal clock while on the other hand some antipsychotic drugs make an opposite change in time perception by descreasing the speed of the clock. Similarly, time perception is affected in some psychiatric disorders and an ethiopathological relationship between time perception disturbances and psychiatric disorders is suggested. In this article time perception changes in schizophrenia, attention deficit/hyperactivity syndrome, depression, anxiety disorders and personality disorders are briefly reviewed.

  7. Influence of parental perception of school safety and gender on children’s physical activity in Mexico: A cross sectional study

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    Amy Hutchens

    2016-01-01

    Full Text Available Objective. This cross sectional study aims to determine the effects of gender and parental perception of safety at school on children’s physical activity (PA levels. Materials and methods. Parents of school aged Mexican children residing in Guadalajara, Mexico City, and Puerto Vallarta, completed surveys about their children’s PA measures. The physical activity indicators were evaluated using linear and logistical regression models. Results. Analysis did not indicate that gender moderated the relationship between parental perception of safety and PA measures, but significant gender issues exist with girls participating less than boys in the three measures of PA in this study (p<0.001. Conclusion. Results suggest the need for additional interventions promoting physical activity in girls in Mexico.

  8. On the number of neurons and time scale of integration underlying the formation of percepts in the brain.

    Science.gov (United States)

    Wohrer, Adrien; Machens, Christian K

    2015-03-01

    All of our perceptual experiences arise from the activity of neural populations. Here we study the formation of such percepts under the assumption that they emerge from a linear readout, i.e., a weighted sum of the neurons' firing rates. We show that this assumption constrains the trial-to-trial covariance structure of neural activities and animal behavior. The predicted covariance structure depends on the readout parameters, and in particular on the temporal integration window w and typical number of neurons K used in the formation of the percept. Using these predictions, we show how to infer the readout parameters from joint measurements of a subject's behavior and neural activities. We consider three such scenarios: (1) recordings from the complete neural population, (2) recordings of neuronal sub-ensembles whose size exceeds K, and (3) recordings of neuronal sub-ensembles that are smaller than K. Using theoretical arguments and artificially generated data, we show that the first two scenarios allow us to recover the typical spatial and temporal scales of the readout. In the third scenario, we show that the readout parameters can only be recovered by making additional assumptions about the structure of the full population activity. Our work provides the first thorough interpretation of (feed-forward) percept formation from a population of sensory neurons. We discuss applications to experimental recordings in classic sensory decision-making tasks, which will hopefully provide new insights into the nature of perceptual integration.

  9. Geostatistical analysis of the flood risk perception queries in the village of Navaluenga (Central Spain)

    Science.gov (United States)

    Guardiola-Albert, Carolina; Díez-Herrero, Andrés; Amérigo, María; García, Juan Antonio; María Bodoque, José; Fernández-Naranjo, Nuria

    2017-04-01

    Flash floods provoke a high average mortality as they are usually unexpected events which evolve rapidly and affect relatively small areas. The short time available for minimizing risks requires preparedness and response actions to be put into practice. Therefore, it is necessary the development of emergency response plans to evacuate and rescue people in the context of a flash-flood hazard. In this framework, risk management has to integrate the social dimension of flash-flooding and its spatial distribution by understanding the characteristics of local communities in order to enhance community resilience during a flash-flood. In this regard, the flash-flood social risk perception of the village of Navaluenga (Central Spain) has been recently assessed, as well as the level of awareness of civil protection and emergency management strategies (Bodoque et al., 2016). This has been done interviewing 254 adults, representing roughly 12% of the population census. The present study wants to go further in the analysis of the resulting questionnaires, incorporating in the analysis the location of home spatial coordinates in order to characterize the spatial distribution and possible geographical interpretation of flood risk perception. We apply geostatistical methods to analyze spatial relations of social risk perception and level of awareness with distance to the rivers (Alberche and Chorrerón) or to the flood-prone areas (50-year, 100-year and 500-year flood plains). We want to discover spatial patterns, if any, using correlation functions (variograms). Geostatistical analyses results can help to either confirm the logical pattern (i.e., less awareness further to the rivers or high return period of flooding) or reveal departures from expected. It can also be possible to identify hot spots, cold spots, and spatial outliers. The interpretation of these spatial patterns can give valuable information to define strategies to improve the awareness regarding preparedness and

  10. Clear signals or mixed messages: inter-individual emotion congruency modulates brain activity underlying affective body perception

    Science.gov (United States)

    de Gelder, B.

    2016-01-01

    The neural basis of emotion perception has mostly been investigated with single face or body stimuli. However, in daily life one may also encounter affective expressions by groups, e.g. an angry mob or an exhilarated concert crowd. In what way is brain activity modulated when several individuals express similar rather than different emotions? We investigated this question using an experimental design in which we presented two stimuli simultaneously, with same or different emotional expressions. We hypothesized that, in the case of two same-emotion stimuli, brain activity would be enhanced, while in the case of two different emotions, one emotion would interfere with the effect of the other. The results showed that the simultaneous perception of different affective body expressions leads to a deactivation of the amygdala and a reduction of cortical activity. It was revealed that the processing of fearful bodies, compared with different-emotion bodies, relied more strongly on saliency and action triggering regions in inferior parietal lobe and insula, while happy bodies drove the occipito-temporal cortex more strongly. We showed that this design could be used to uncover important differences between brain networks underlying fearful and happy emotions. The enhancement of brain activity for unambiguous affective signals expressed by several people simultaneously supports adaptive behaviour in critical situations. PMID:27025242

  11. The Perception of Physical Activity in Ambulatory Persons with Late Effects of Polio: A Qualitative Study.

    Science.gov (United States)

    Winberg, Cecilia; Carlsson, Gunilla; Brogårdh, Christina; Lexell, Jan

    2017-01-01

    Maintaining regular physical activity (PA) can be challenging for persons with late effects of polio. This qualitative study of ambulatory persons with late effects of polio explored their perceptions of PA, as well as facilitators of and barriers to PA. Semistructured interviews were conducted with 15 persons and analyzed with content analysis using the International Classification of Functioning, Disability and Health (ICF) as a framework. The participants described positive perceptions of PA and its health benefits. PA was used to prevent further decline in functioning, and the type and frequency of activities had changed over time. Past experiences and personal characteristics impacted PA. Support from close relatives, knowledgeable health care professionals, mobility devices, and accessible environments facilitated PA, whereas impairments, inaccessible environments, and cold weather were the main barriers. To perform PA regularly, persons with late effects of polio may benefit from individualized advice based on their disability and personal and environmental factors.

  12. Agritourism activities in the Mopani District Municipality, Limpopo Province, South Africa: perceptions and opportunities

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    S L Myer

    2013-12-01

    Full Text Available Farms in South Africa have to compete in a very hostile agricultural economic environment and it has become imperative for farmers to find new ways of generating additional income. Research undertaken in the Mopani District Municipality (MDM in the Limpopo Province of South Africa identified agritourism as a potential means to this end. The main aim of this primarily qualitative study was to gain a better understanding of the perceptions and opportunities for agritourism in the study area. Data were mainly collected through interviews and questionnaires. Participants consisted of farmers and tourists, as well as owners of existing agritourism farms within the MDM. Five current active agritourism establishments were identified. Key fidnings revealed that agritourism is not being utilised to its full potential. Although perceptions of respondents towards agritourism are positive, marketing around it is insufficient and not all farmers are willing to host agritourism activities on their farms for various reasons. However, the MDM is a tourist hub with many visitors passing through various reasons. However, the MDM is a tourist hub with many visitors passing through the area en route to the Kruger National Park. Therefore, the potential already exists to host agritourism activities that will benefit farmers in various ways. By developing farm trails, scheduling daily farm activities, using information brochures, forming networks with existing tourist establishments, encouraging the use of local and fresh produce and providing good roadside signage, farmers can gain increased exposure and recognition for what they do and opportunities for growth and development may be realised.  Keywords: Agritourism, farm tourism, alternative tourism, farm activities, tourism

  13. Mapping Muscles Activation to Force Perception during Unloading.

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    Simone Toma

    Full Text Available It has been largely proved that while judging a force humans mainly rely on the motor commands produced to interact with that force (i.e., sense of effort. Despite of a large bulk of previous investigations interested in understanding the contributions of the descending and ascending signals in force perception, very few attempts have been made to link a measure of neural output (i.e., EMG to the psychophysical performance. Indeed, the amount of correlation between EMG activity and perceptual decisions can be interpreted as an estimate of the contribution of central signals involved in the sensation of force. In this study we investigated this correlation by measuring the muscular activity of eight arm muscles while participants performed a quasi-isometric force detection task. Here we showed a method to quantitatively describe muscular activity ("muscle-metric function" that was directly comparable to the description of the participants' psychophysical decisions about the stimulus force. We observed that under our experimental conditions, muscle-metric absolute thresholds and the shape of the muscle-metric curves were closely related to those provided by the psychophysics. In fact a global measure of the muscles considered was able to predict approximately 60% of the perceptual decisions total variance. Moreover the inter-subjects differences in psychophysical sensitivity showed high correlation with both participants' muscles sensitivity and participants' joint torques. Overall, our findings gave insights into both the role played by the corticospinal motor commands while performing a force detection task and the influence of the gravitational muscular torque on the estimation of vertical forces.

  14. Optimal rotation sequences for active perception

    Science.gov (United States)

    Nakath, David; Rachuy, Carsten; Clemens, Joachim; Schill, Kerstin

    2016-05-01

    One major objective of autonomous systems navigating in dynamic environments is gathering information needed for self localization, decision making, and path planning. To account for this, such systems are usually equipped with multiple types of sensors. As these sensors often have a limited field of view and a fixed orientation, the task of active perception breaks down to the problem of calculating alignment sequences which maximize the information gain regarding expected measurements. Action sequences that rotate the system according to the calculated optimal patterns then have to be generated. In this paper we present an approach for calculating these sequences for an autonomous system equipped with multiple sensors. We use a particle filter for multi- sensor fusion and state estimation. The planning task is modeled as a Markov decision process (MDP), where the system decides in each step, what actions to perform next. The optimal control policy, which provides the best action depending on the current estimated state, maximizes the expected cumulative reward. The latter is computed from the expected information gain of all sensors over time using value iteration. The algorithm is applied to a manifold representation of the joint space of rotation and time. We show the performance of the approach in a spacecraft navigation scenario where the information gain is changing over time, caused by the dynamic environment and the continuous movement of the spacecraft

  15. Spatial patterns of persistent neural activity vary with the behavioral context of short-term memory.

    Science.gov (United States)

    Daie, Kayvon; Goldman, Mark S; Aksay, Emre R F

    2015-02-18

    A short-term memory can be evoked by different inputs and control separate targets in different behavioral contexts. To address the circuit mechanisms underlying context-dependent memory function, we determined through optical imaging how memory is encoded at the whole-network level in two behavioral settings. Persistent neural activity maintaining a memory of desired eye position was imaged throughout the oculomotor integrator after saccadic or optokinetic stimulation. While eye position was encoded by the amplitude of network activity, the spatial patterns of firing were context dependent: cells located caudally generally were most persistent following saccadic input, whereas cells located rostrally were most persistent following optokinetic input. To explain these data, we computationally identified four independent modes of network activity and found these were differentially accessed by saccadic and optokinetic inputs. These results show how a circuit can simultaneously encode memory value and behavioral context, respectively, in its amplitude and spatial pattern of persistent firing. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Spatial ability of slow learners based on Hubert Maier theory

    Science.gov (United States)

    Permatasari, I.; Pramudya, I.; Kusmayadi, T. A.

    2018-03-01

    Slow learners are children who have low learning achievement (under the average of normal children) in one or all of the academic field, but they are not classified as a mentally retarded children. Spatial ability developed according to age and level of knowledge possessed, both from the neighborhood and formal education. Analyzing the spatial ability of students is important for teachers, as an effort to improve the quality of learning for slow learners. Especially on the implementation of inclusion school which is developing in Indonesia. This research used a qualitative method and involved slow learner students as the subject. Based on the data analysis it was found the spatial ability of slow learners, there were: spatial perception, students were able to describe the other shape of object when its position changed; spatial visualisation, students were able to describe the materials that construct an object; mental rotation, students cannot describe the object being rotated; spatial relation, students cannot describe the relations of same objects; spatial orientation, students were able to describe object from the others perspective.

  17. Incorporating twitter-based human activity information in spatial analysis of crashes in urban areas.

    Science.gov (United States)

    Bao, Jie; Liu, Pan; Yu, Hao; Xu, Chengcheng

    2017-09-01

    The primary objective of this study was to investigate how to incorporate human activity information in spatial analysis of crashes in urban areas using Twitter check-in data. This study used the data collected from the City of Los Angeles in the United States to illustrate the procedure. The following five types of data were collected: crash data, human activity data, traditional traffic exposure variables, road network attributes and social-demographic data. A web crawler by Python was developed to collect the venue type information from the Twitter check-in data automatically. The human activities were classified into seven categories by the obtained venue types. The collected data were aggregated into 896 Traffic Analysis Zones (TAZ). Geographically weighted regression (GWR) models were developed to establish a relationship between the crash counts reported in a TAZ and various contributing factors. Comparative analyses were conducted to compare the performance of GWR models which considered traditional traffic exposure variables only, Twitter-based human activity variables only, and both traditional traffic exposure and Twitter-based human activity variables. The model specification results suggested that human activity variables significantly affected the crash counts in a TAZ. The results of comparative analyses suggested that the models which considered both traditional traffic exposure and human activity variables had the best goodness-of-fit in terms of the highest R 2 and lowest AICc values. The finding seems to confirm the benefits of incorporating human activity information in spatial analysis of crashes using Twitter check-in data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. A CROSS-CULTURAL COMPARISON OF TOURISTS’ PERCEPTIONS OF HOTEL LOBBIES

    Directory of Open Access Journals (Sweden)

    Emine Köseoglu

    2012-11-01

    Full Text Available This study examines cultural differences in the perception of hotel lobbies. It aims to determine the differences/similarities within spatial preferences in hotel lobbies by focusing on three aspects of space: physical appearance, configuration, and usage and privacy arrangements. To measure the differences, a survey is conducted in Sultanahmet, Istanbul with tourists within two focus groups from Asian and European countries (n= 30 each. They are asked to rate their agreement with each statement about the spatial features on a 5-point Likert scale. As a result, both differences and similarities in the perception of the tourists from different cultures are found. It can be noted that there are statistically significant differences between the two groups in terms of configurational features and usage and privacy arrangement of lobbies. The results provide designers some data to create a space for similar user profiles.

  19. Experimental investigation on spontaneously active hippocampal cultures recorded by means of high-density MEAs: analysis of the spatial resolution effects

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    Alessandro Maccione

    2010-05-01

    Full Text Available Based on experiments performed with high-resolution Active Pixel Sensor microelectrode arrays (APS-MEAs coupled with spontaneously active hippocampal cultures, this work investigates the spatial resolution effects of the neuroelectronic interface on the analysis of the recorded electrophysiological signals. The adopted methodology consists, first, in recording the spontaneous activity at the highest spatial resolution (inter-electrode separation of 21 µm from the whole array of 4096 microelectrodes. Then, the full resolution dataset is spatially down sampled in order to evaluate the effects on raster plot representation, array-wide spike rate (AWSR, mean firing rate (MFR and mean bursting rate (MBR. Furthermore, the effects of the array-to-network relative position are evaluated by shifting a subset of equally spaced electrodes on the entire recorded area. Results highlight that MFR and MBR are particularly influenced by the spatial resolution provided by the neuroelectronic interface. On high-resolution large MEAs, such analysis better represent the time-based parameterization of the network dynamics. Finally, this work suggest interesting capabilities of high-resolution MEAs for spatial-based analysis in dense and low-dense neuronal preparation for investigating signalling at both local and global neuronal circuitries.

  20. Measuring teacher regulating activities concerning student learning in secondary education classrooms : Reliability and validity of student perceptions

    NARCIS (Netherlands)

    van Beek, J. A.; de Jong, F. P. C. M.; Wubbels, Th.; Minnaert, A. E. M. G.

    2014-01-01

    This article describes the use and validation of the Pedagogical Practices Inventory, which uses student perceptions arranged into five subscales to measure teacher activities concerning the regulation of student learning in secondary education. To determine the reliability and validity of the

  1. A Rehabilitation Protocol for Empowering Spatial Orientation in MCI. A Pilot Study.

    Science.gov (United States)

    Gadler, Erminia; Grassi, Alessandra; Riva, Giuseppe

    2009-01-01

    Spatial navigation is among the first cognitive functions to be impaired in Alzheimer's disease [1] and deficit in this domain is detectable earlier in patients with Mild Cognitive Impairment [2]. Since efficacy of cognitive training in persons with MCI was successfully assessed [3], we developed a multitasking training protocol using virtual environments for stimulating attention, perception and visuo-spatial cognition in order to empower spatial orientation in MCI. Two healthy elders were exposed to the training over a period of four weeks and both showed improved performances in attention and orientation after the end of the intervention.

  2. The problems of peculiarity regeneration of architectural-spatial environment of demolished cities

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    Babakhanyans Dalar

    2017-01-01

    Full Text Available Boundaries of national and international, typical and peculiar, individual and mass are ignored in the present conditions of battles (globalization, leakage of information, loss of technology, fast programs and the observation and regeneration of architectural-spatial environments has become very important. The article observes the revelation of this problem with regeneration of architectural-spatial environment of Gyumri city. The goal is to determine modern approaches of observance of the peculiarity of cities. The problem is to study development demands of architectural-spatial environment in modern and historical cities, to study its perception mechanisms , the main factors and patterns.

  3. Global-local visual biases correspond with visual-spatial orientation.

    Science.gov (United States)

    Basso, Michael R; Lowery, Natasha

    2004-02-01

    Within the past decade, numerous investigations have demonstrated reliable associations of global-local visual processing biases with right and left hemisphere function, respectively (cf. Van Kleeck, 1989). Yet the relevance of these biases to other cognitive functions is not well understood. Towards this end, the present research examined the relationship between global-local visual biases and perception of visual-spatial orientation. Twenty-six women and 23 men completed a global-local judgment task (Kimchi and Palmer, 1982) and the Judgment of Line Orientation Test (JLO; Benton, Sivan, Hamsher, Varney, and Spreen, 1994), a measure of visual-spatial orientation. As expected, men had better performance on JLO. Extending previous findings, global biases were related to better visual-spatial acuity on JLO. The findings suggest that global-local biases and visual-spatial orientation may share underlying cerebral mechanisms. Implications of these findings for other visually mediated cognitive outcomes are discussed.

  4. Synaptic Correlates of Low-Level Perception in V1.

    Science.gov (United States)

    Gerard-Mercier, Florian; Carelli, Pedro V; Pananceau, Marc; Troncoso, Xoana G; Frégnac, Yves

    2016-04-06

    The computational role of primary visual cortex (V1) in low-level perception remains largely debated. A dominant view assumes the prevalence of higher cortical areas and top-down processes in binding information across the visual field. Here, we investigated the role of long-distance intracortical connections in form and motion processing by measuring, with intracellular recordings, their synaptic impact on neurons in area 17 (V1) of the anesthetized cat. By systematically mapping synaptic responses to stimuli presented in the nonspiking surround of V1 receptive fields, we provide the first quantitative characterization of the lateral functional connectivity kernel of V1 neurons. Our results revealed at the population level two structural-functional biases in the synaptic integration and dynamic association properties of V1 neurons. First, subthreshold responses to oriented stimuli flashed in isolation in the nonspiking surround exhibited a geometric organization around the preferred orientation axis mirroring the psychophysical "association field" for collinear contour perception. Second, apparent motion stimuli, for which horizontal and feedforward synaptic inputs summed in-phase, evoked dominantly facilitatory nonlinear interactions, specifically during centripetal collinear activation along the preferred orientation axis, at saccadic-like speeds. This spatiotemporal integration property, which could constitute the neural correlate of a human perceptual bias in speed detection, suggests that local (orientation) and global (motion) information is already linked within V1. We propose the existence of a "dynamic association field" in V1 neurons, whose spatial extent and anisotropy are transiently updated and reshaped as a function of changes in the retinal flow statistics imposed during natural oculomotor exploration. The computational role of primary visual cortex in low-level perception remains debated. The expression of this "pop-out" perception is often assumed

  5. Independent mobility, perceptions of the built environment and children's participation in play, active travel and structured exercise and sport: the PEACH Project

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    Griew Pippa

    2010-02-01

    Full Text Available Abstract Background Independent mobility (IM and perceptions of the built environment may relate differentially to children's participation in various physical activity contexts. This cross-sectional study investigated whether independent mobility and perceptions of the built environment in boys and girls were related to physical activity in three different contexts (outdoor play, structured exercise/sport, active commuting. Methods Thirteen hundred and seven 10-11 year old boys and girls from 23 schools in a large UK city completed a computerised questionnaire. Independent variables in logistic regression analyses were weekly self-reported frequency of participation in outdoor play, structured exercise/sport and mode of travel home from school. Dependent variables were perceptions of the environment (aesthetics, nuisance, safety, social norm, constraint, play space, accessibility, local and area independent mobility and linear distance from home to school. Analyses were adjusted for body mass index, minutes of daylight after school, level of neighbourhood deprivation and pubertal status. Results For boys, local independent mobility (Local-IM was related to an increased likelihood of everyday participation in play (OR 1.58: 95% CI 1.19-2.10, structured exercise/sport (OR 1.42: 1.06-1.89 and active commuting (OR 1.40: 1.07-1.87 but was only related to active commuting for girls (OR1.49: 1.07-2.07. Boys and girls were more likely to report playing out every day if they had higher scores for Social Norm (Boys: OR 1.63 (1.12-2.37; Girls: OR 1.53 (1.01-2.31 and, for girls only, more positive perceptions of traffic safety (OR 1.63: 1.14-2.34. Easy access to a range of destinations was the dominant predictor for taking part in structured exercise/sport everyday (Boys: OR 1.62 (1.01-2.66; Girls: OR 1.65 (1.07-2.53. Shorter distance from home to school (OR 0.99: 0.98-0.99 and, for boys only, greater perceived accessibility (OR 1.87: 1.04-3.36 were

  6. The perception of prosody and associated auditory cues in early-implanted children: the role of auditory working memory and musical activities.

    Science.gov (United States)

    Torppa, Ritva; Faulkner, Andrew; Huotilainen, Minna; Järvikivi, Juhani; Lipsanen, Jari; Laasonen, Marja; Vainio, Martti

    2014-03-01

    To study prosodic perception in early-implanted children in relation to auditory discrimination, auditory working memory, and exposure to music. Word and sentence stress perception, discrimination of fundamental frequency (F0), intensity and duration, and forward digit span were measured twice over approximately 16 months. Musical activities were assessed by questionnaire. Twenty-one early-implanted and age-matched normal-hearing (NH) children (4-13 years). Children with cochlear implants (CIs) exposed to music performed better than others in stress perception and F0 discrimination. Only this subgroup of implanted children improved with age in word stress perception, intensity discrimination, and improved over time in digit span. Prosodic perception, F0 discrimination and forward digit span in implanted children exposed to music was equivalent to the NH group, but other implanted children performed more poorly. For children with CIs, word stress perception was linked to digit span and intensity discrimination: sentence stress perception was additionally linked to F0 discrimination. Prosodic perception in children with CIs is linked to auditory working memory and aspects of auditory discrimination. Engagement in music was linked to better performance across a range of measures, suggesting that music is a valuable tool in the rehabilitation of implanted children.

  7. Uncertainty in spatial planning proceedings

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    Aleš Mlakar

    2009-01-01

    Full Text Available Uncertainty is distinctive of spatial planning as it arises from the necessity to co-ordinate the various interests within the area, from the urgency of adopting spatial planning decisions, the complexity of the environment, physical space and society, addressing the uncertainty of the future and from the uncertainty of actually making the right decision. Response to uncertainty is a series of measures that mitigate the effects of uncertainty itself. These measures are based on two fundamental principles – standardization and optimization. The measures are related to knowledge enhancement and spatial planning comprehension, in the legal regulation of changes, in the existence of spatial planning as a means of different interests co-ordination, in the active planning and the constructive resolution of current spatial problems, in the integration of spatial planning and the environmental protection process, in the implementation of the analysis as the foundation of spatial planners activities, in the methods of thinking outside the parameters, in forming clear spatial concepts and in creating a transparent management spatial system and also in the enforcement the participatory processes.

  8. Optic Flow Information Influencing Heading Perception during Rotation

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    Diederick C. Niehorster

    2011-05-01

    Full Text Available We investigated what roles global spatial frequency, surface structure, and foreground motion play in heading perception during simulated rotation from optic flow. The display (110°Hx94°V simulated walking on a straight path over a ground plane (depth range: 1.4–50 m at 2 m/s while fixating a target off to one side (mean R/T ratios: ±1, ±2, ±3 under six display conditions. Four displays consisted of nonexpanding dots that were distributed so as to manipulate the amount of foreground motion and the presence of surface structure. In one further display the ground was covered with disks that expanded during the trial and lastly a textured ground display was created with the same spatial frequency power spectrum as the disk ground. At the end of each 1s trial, observers indicated their perceived heading along a line at the display's center. Mean heading biases were smaller for the textured than for the disk ground, for the displays with more foreground motion and for the displays with surface structure defined by dot motion than without. We conclude that while spatial frequency content is not a crucial factor, dense motion parallax and surface structure in optic flow are important for accurate heading perception during rotation.

  9. Active and passive spatial learning in human navigation: acquisition of survey knowledge.

    Science.gov (United States)

    Chrastil, Elizabeth R; Warren, William H

    2013-09-01

    It seems intuitively obvious that active exploration of a new environment would lead to better spatial learning than would passive visual exposure. It is unclear, however, which components of active learning contribute to spatial knowledge, and previous literature is decidedly mixed. This experiment tests the contributions of 4 components to metric survey knowledge: visual, vestibular, and podokinetic information and cognitive decision making. In the learning phase, 6 groups of participants learned the locations of 8 objects in a virtual hedge maze by (a) walking, (b) being pushed in a wheelchair, or (c) watching a video, crossed with (1) making decisions about their path or (2) being guided through the maze. In the test phase, survey knowledge was assessed by having participants walk a novel shortcut from a starting object to the remembered location of a test object, with the maze removed. Performance was slightly better than chance in the passive video condition. The addition of vestibular information did not improve performance in the wheelchair condition, but the addition of podokinetic information significantly improved angular accuracy in the walking condition. In contrast, there was no effect of decision making in any condition. The results indicate that visual and podokinetic information significantly contribute to survey knowledge, whereas vestibular information and decision making do not. We conclude that podokinetic information is the primary component of active learning for the acquisition of metric survey knowledge. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  10. Perception of the older adults regarding the practise of physical activity and healthy eating

    OpenAIRE

    de Rosso Krug, Rodrigo; Rodrigues Barbosa, Aline; Aita Monego, Estela; Ferreira de Mello, Ana Lúcia Schaefer; Francielle França, Vivian

    2015-01-01

    Objective: To understand the perception of regular physical activity and healthy eating among the older adults. Methods: This descriptive study (qualitative approach) included 36 older adults (69 to 91 years) residents in a rural community in southern Brazil. A semi-structured interview was used and the information were recorded, transcribed and interpreted (content analysis technique). Results: The following categories of analysis were identified: a) facilitators and barriers for the practis...

  11. Genre Differences on Visual Perception of Color Range and Depth of Field

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    Luisa Ballesteros

    2003-07-01

    Full Text Available Visual perception is the result of the integration of various related factors of the observed object and its environment. In this study we evaluated the impact of tridimensional form on color perception and the angle from the horizontal plane of a set of similar objets on the depth of field perception between young men and women. A panel half magenta and half white placed at the end of a black box, folded either concaved or convexed to alter the chromatic effect perceived were used to determine tridimensional form on color perception. Four sets of identical sticks where the angle from the horizontal plane varied for each, were used to determine the effect of spatial distribution of depth of field perception. The parameters taking into account were age, genre, associated visual defects for each individual evaluated. Our results show that the tridimensional form alters color perception but the range of color perceived was larger for women whereas depending on the angle from the horizontal plane we found genre differences on the depth of field perception.

  12. Daily practical activities and science teaching at EJA: Teacher and students' perception

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    Denise Westphal Merazzi

    2007-06-01

    Full Text Available The main theme of this paper is the science teaching in Adults and Youth Education. It was investigated the students' perceptions of adult and youth education (elementary school and their teachers, from science content's development through the works involving practical activities of everyday life. In this context, the methodology used in the research process was based on a survey of qualitative and quantitative approach, with hermeneutic content analysis' methodology and technique. In quantitative terms, we used the average ranking and statistical tests of Wilcoxon. Analyzing the data obtained, it was observed that the use of practical activities in science teaching in adult education is a satisfactory strategy for teaching and learning process and that there is a need to instill these practices in young and adults' education

  13. Human hippocampal and parahippocampal activity during visual associative recognition memory for spatial and nonspatial stimulus configurations.

    Science.gov (United States)

    Düzel, Emrah; Habib, Reza; Rotte, Michael; Guderian, Sebastian; Tulving, Endel; Heinze, Hans-Jochen

    2003-10-15

    Evidence from animal studies points to the importance of the parahippocampal region (PHR) [including entorhinal, perirhinal, and parahippocampal (PHC) cortices] for recognition of visual stimuli. Recent findings in animals suggest that PHR may also be involved in visual associative recognition memory for configurations of stimuli. Thus far, however, such involvement has not been demonstrated in humans. In fact, it has been argued that associative recognition in humans is critically dependent on the hippocampal formation (HF). To better understand the division of function between HF and PHR during recognition memory in humans, we measured the activity of both areas in healthy young adults during an associative recognition memory task using functional magnetic resonance imaging. To more precisely characterize the nature of the associations that might be coded by the HF and PHR during recognition, subjects were required to learn and were later tested for associations based on either the spatial arrangements of two stimuli or the identity of two stimuli (a face and a tool). An area in the PHC was found to be more active for recognized old configurations than new configurations in both the spatial and identity conditions. The HF, on the other hand, was more active for recognition of new configurations than old configurations and also more active in the spatial than the identity condition. These data highlight the involvement of PHR in the long-term coding of associative relationships between stimuli and help to clarify the nature of its functional distinction from the HF.

  14. Spatial vision in insects is facilitated by shaping the dynamics of visual input through behavioural action

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    Martin eEgelhaaf

    2012-12-01

    Full Text Available Insects such as flies or bees, with their miniature brains, are able to control highly aerobatic flight manoeuvres and to solve spatial vision tasks, such as avoiding collisions with obstacles, landing on objects or even localizing a previously learnt inconspicuous goal on the basis of environmental cues. With regard to solving such spatial tasks, these insects still outperform man-made autonomous flying systems. To accomplish their extraordinary performance, flies and bees have been shown by their characteristic behavioural actions to actively shape the dynamics of the image flow on their eyes (optic flow. The neural processing of information about the spatial layout of the environment is greatly facilitated by segregating the rotational from the translational optic flow component through a saccadic flight and gaze strategy. This active vision strategy thus enables the nervous system to solve apparently complex spatial vision tasks in a particularly efficient and parsimonious way. The key idea of this review is that biological agents, such as flies or bees, acquire at least part of their strength as autonomous systems through active interactions with their environment and not by simply processing passively gained information about the world. These agent-environment interactions lead to adaptive behaviour in surroundings of a wide range of complexity. Animals with even tiny brains, such as insects, are capable of performing extraordinarily well in their behavioural contexts by making optimal use of the closed action–perception loop. Model simulations and robotic implementations show that the smart biological mechanisms of motion computation and visually-guided flight control might be helpful to find technical solutions, for example, when designing micro air vehicles carrying a miniaturized, low-weight on-board processor.

  15. Yersinia pseudotuberculosis Spatially Controls Activation and Misregulation of Host Cell Rac1.

    Directory of Open Access Journals (Sweden)

    2005-10-01

    Full Text Available Yersinia pseudotuberculosis binds host cells and modulates the mammalian Rac1 guanosine triphosphatase (GTPase at two levels. Activation of Rac1 results from integrin receptor engagement, while misregulation is promoted by translocation of YopE and YopT proteins into target cells. Little is known regarding how these various factors interplay to control Rac1 dynamics. To investigate these competing processes, the localization of Rac1 activation was imaged microscopically using fluorescence resonance energy transfer. In the absence of translocated effectors, bacteria induced activation of the GTPase at the site of bacterial binding. In contrast, the entire cellular pool of Rac1 was inactivated shortly after translocation of YopE RhoGAP. Inactivation required membrane localization of Rac1. The translocated protease YopT had very different effects on Rac1. This protein, which removes the membrane localization site of Rac1, did not inactivate Rac1, but promoted entry of cleaved activated Rac1 molecules into the host cell nucleus, allowing Rac1 to localize with nuclear guanosine nucleotide exchange factors. As was true for YopE, membrane-associated Rac1 was the target for YopT, indicating that the two translocated effectors may compete for the same pool of target protein. Consistent with the observation that YopE inactivation requires membrane localization of Rac1, the presence of YopT in the cell interfered with the action of the YopE RhoGAP. As a result, interaction of target cells with a strain that produces both YopT and YopE resulted in two spatially distinct pools of Rac1: an inactive cytoplasmic pool and an activated nuclear pool. These studies demonstrate that competition between bacterial virulence factors for access to host substrates is controlled by the spatial arrangement of a target protein. In turn, the combined effects of translocated bacterial proteins are to generate pools of a single signaling molecule with distinct localization and

  16. Body image and weight perceptions in relation to actual measurements by means of a new index and level of physical activity in Italian university students.

    Science.gov (United States)

    Zaccagni, Luciana; Masotti, Sabrina; Donati, Roberta; Mazzoni, Gianni; Gualdi-Russo, Emanuela

    2014-02-11

    Body image perception depends on anthropometric and psychological factors. Body dissatisfaction is influenced by the socio-cultural environment and is associated with eating disorders and low self-esteem. This study examined the body image perception, the degree of dissatisfaction and the weight status perception inconsistency in relation to sex, weight status and amount of physical activity in a sample of university students. The participants were 734 university students (354 females aged 21.5 ± 2.9 yrs and 380 males aged 22.1 ± 3.6 yrs) recruited from the second year of the Sport Sciences degree program. A self-administered questionnaire was used to acquire socio-demographic and sport participation information. Height, weight, BMI and weight status were considered for each subject. Body image perception was assessed by a silhouette matching technique. A new index, FAI (Feel status minus Actual status Inconsistency), was used to assess weight status perception inconsistency. A large proportion of the sample had normal weight status. On average, females chose as feel status a significantly higher figure than the males (4.7 versus 3.8) and they would have liked to have a significantly thinner figure than the males (3.4 versus 3.6). Therefore, the mean FID (Feel minus Ideal Discrepancy) values (positive in both sexes) were significantly higher in females than in males, meaning higher dissatisfaction. The mean FAI values were positive in females and negative in males, indicating a tendency of the women to overestimate their weight status and of the men to underestimate it. Men were more physically active than women. Less active women showed significantly lower body weight and BMI than more active women. Men less engaged in physical activity showed significantly higher FID than more active men. These results show greater dissatisfaction and higher weight status perception consistency in females than in males among Italian university students examined. Our findings

  17. Perceptions of preclinical medical students towards extracurricular activities.

    Science.gov (United States)

    Almasry, Mazen; Kayali, Zeina; Alsaad, Rakan; Alhayaza, Ghada; Ahmad, Mohammad Sharique; Obeidat, Akef; Abu-Zaid, Ahmed

    2017-08-16

    To determine the percentage of students involved in extracurricular activities (EAs), explore relationships between participation in EAs and students' characteristics, and investigate students' perceptions (i.e., motives and barriers) towards participation in EAs. An online, anonymous, random, cross-sectional, self-rating survey was administered during spring 2015-2016 to second-year and third-year students (n=340). Chi-square test was used to explore relationships between participation in EAs and students' characteristics. Mann-Whitney U-test was used to compare the mean 5-point Likert scale responses according to students' characteristics. Statistical significance was determined as pstudents participated in the survey (n=237/340, response rate: 69.7%). Only 143 students (60.3%, n=140/237) participated in EAs, and this percentage significantly differed by gender (χ 2 (1, N=237)=4.3205, pstudents regarding the following barrier: "affect academic performance negatively" (U=5389.5, psatisfactory, and positively related to students' characteristics of male gender, non-Saudi nationality and high cGPA. Medical schools should facilitate all potential motives and resolve all associated barriers towards participation in EAs.

  18. Clear signals or mixed messages: inter-individual emotion congruency modulates brain activity underlying affective body perception.

    Science.gov (United States)

    de Borst, A W; de Gelder, B

    2016-08-01

    The neural basis of emotion perception has mostly been investigated with single face or body stimuli. However, in daily life one may also encounter affective expressions by groups, e.g. an angry mob or an exhilarated concert crowd. In what way is brain activity modulated when several individuals express similar rather than different emotions? We investigated this question using an experimental design in which we presented two stimuli simultaneously, with same or different emotional expressions. We hypothesized that, in the case of two same-emotion stimuli, brain activity would be enhanced, while in the case of two different emotions, one emotion would interfere with the effect of the other. The results showed that the simultaneous perception of different affective body expressions leads to a deactivation of the amygdala and a reduction of cortical activity. It was revealed that the processing of fearful bodies, compared with different-emotion bodies, relied more strongly on saliency and action triggering regions in inferior parietal lobe and insula, while happy bodies drove the occipito-temporal cortex more strongly. We showed that this design could be used to uncover important differences between brain networks underlying fearful and happy emotions. The enhancement of brain activity for unambiguous affective signals expressed by several people simultaneously supports adaptive behaviour in critical situations. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  19. Face processing is gated by visual spatial attention

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    Roy E Crist

    2008-03-01

    Full Text Available Human perception of faces is widely believed to rely on automatic processing by a domain-specifi c, modular component of the visual system. Scalp-recorded event-related potential (ERP recordings indicate that faces receive special stimulus processing at around 170 ms poststimulus onset, in that faces evoke an enhanced occipital negative wave, known as the N170, relative to the activity elicited by other visual objects. As predicted by modular accounts of face processing, this early face-specifi c N170 enhancement has been reported to be largely immune to the infl uence of endogenous processes such as task strategy or attention. However, most studies examining the infl uence of attention on face processing have focused on non-spatial attention, such as object-based attention, which tend to have longer-latency effects. In contrast, numerous studies have demonstrated that visual spatial attention can modulate the processing of visual stimuli as early as 80 ms poststimulus – substantially earlier than the N170. These temporal characteristics raise the question of whether this initial face-specifi c processing is immune to the infl uence of spatial attention. This question was addressed in a dual-visualstream ERP study in which the infl uence of spatial attention on the face-specifi c N170 could be directly examined. As expected, early visual sensory responses to all stimuli presented in an attended location were larger than responses evoked by those same stimuli when presented in an unattended location. More importantly, a signifi cant face-specifi c N170 effect was elicited by faces that appeared in an attended location, but not in an unattended one. In summary, early face-specifi c processing is not automatic, but rather, like other objects, strongly depends on endogenous factors such as the allocation of spatial attention. Moreover, these fi ndings underscore the extensive infl uence that top-down attention exercises over the processing of

  20. Multimodal Hierarchical Dirichlet Process-Based Active Perception by a Robot

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    Tadahiro Taniguchi

    2018-05-01

    Full Text Available In this paper, we propose an active perception method for recognizing object categories based on the multimodal hierarchical Dirichlet process (MHDP. The MHDP enables a robot to form object categories using multimodal information, e.g., visual, auditory, and haptic information, which can be observed by performing actions on an object. However, performing many actions on a target object requires a long time. In a real-time scenario, i.e., when the time is limited, the robot has to determine the set of actions that is most effective for recognizing a target object. We propose an active perception for MHDP method that uses the information gain (IG maximization criterion and lazy greedy algorithm. We show that the IG maximization criterion is optimal in the sense that the criterion is equivalent to a minimization of the expected Kullback–Leibler divergence between a final recognition state and the recognition state after the next set of actions. However, a straightforward calculation of IG is practically impossible. Therefore, we derive a Monte Carlo approximation method for IG by making use of a property of the MHDP. We also show that the IG has submodular and non-decreasing properties as a set function because of the structure of the graphical model of the MHDP. Therefore, the IG maximization problem is reduced to a submodular maximization problem. This means that greedy and lazy greedy algorithms are effective and have a theoretical justification for their performance. We conducted an experiment using an upper-torso humanoid robot and a second one using synthetic data. The experimental results show that the method enables the robot to select a set of actions that allow it to recognize target objects quickly and accurately. The numerical experiment using the synthetic data shows that the proposed method can work appropriately even when the number of actions is large and a set of target objects involves objects categorized into multiple classes

  1. Modulation frequency as a cue for auditory speed perception.

    Science.gov (United States)

    Senna, Irene; Parise, Cesare V; Ernst, Marc O

    2017-07-12

    Unlike vision, the mechanisms underlying auditory motion perception are poorly understood. Here we describe an auditory motion illusion revealing a novel cue to auditory speed perception: the temporal frequency of amplitude modulation (AM-frequency), typical for rattling sounds. Naturally, corrugated objects sliding across each other generate rattling sounds whose AM-frequency tends to directly correlate with speed. We found that AM-frequency modulates auditory speed perception in a highly systematic fashion: moving sounds with higher AM-frequency are perceived as moving faster than sounds with lower AM-frequency. Even more interestingly, sounds with higher AM-frequency also induce stronger motion aftereffects. This reveals the existence of specialized neural mechanisms for auditory motion perception, which are sensitive to AM-frequency. Thus, in spatial hearing, the brain successfully capitalizes on the AM-frequency of rattling sounds to estimate the speed of moving objects. This tightly parallels previous findings in motion vision, where spatio-temporal frequency of moving displays systematically affects both speed perception and the magnitude of the motion aftereffects. Such an analogy with vision suggests that motion detection may rely on canonical computations, with similar neural mechanisms shared across the different modalities. © 2017 The Author(s).

  2. Focusing elementary students with active classrooms: exploring teachers’ perceptions of self-initiated practices

    Directory of Open Access Journals (Sweden)

    Christine A. Foran

    2017-09-01

    Full Text Available The aim of our study was to explore the perceptions of elementary teachers who routinely prioritized physical activity in their classrooms. Researchers are reporting improved student academic test results following physical activity sessions, however, classroom teachers are challenged in balancing curricular and other expectations. Hence, teachers who voluntarily implement physical activity have views that are unique and important for promoting the practice to others. We interviewed seven teachers from grades 1-6, using the qualitative constructivist approach to grounded theory qualitative research. Teachers valued physical activity because it enhanced their students’ focus on classroom activities. Common attributes amongst the teachers were active lifestyles, previous employment experiencesusing physical activity, and a pedagogical approach prioritizing physical activity throughout the day. Additionally, the teachers perceived that belonging to schools with a culture of movement was important. Teachers view physical activity as a teaching asset when they perceive a positive impact on their students’ ability to focus. Specific teacher attributes and a school environment that embraces physical activity may predispose teachers to these views, and represent areas that should be further explored. Pre-service courses could be one way to provide teachers with experience and a repertoire of easy physical activities.

  3. A Self-Categorization Explanation for Opinion Consensus Perceptions

    Science.gov (United States)

    Zhang, Jinguang; Reid, Scott A.

    2013-01-01

    The public expression of opinions (and related communicative activities) hinges upon the perception of opinion consensus. Current explanations for opinion consensus perceptions typically focus on egocentric and other biases, rather than functional cognitions. Using self-categorization theory we showed that opinion consensus perceptions flow from…

  4. Perceptions of diet, physical activity, and obesity-related health among black daughter-mother pairs in Soweto, South Africa: a qualitative study

    Directory of Open Access Journals (Sweden)

    Emily A. Phillips

    2016-08-01

    Full Text Available Abstract Background The prevalence of overweight and obesity is on the rise in South Africa, particularly among females living in urban environments. The purpose of this qualitative study was to explore the emic perspectives of black young adult daughter and mother pairs living in Soweto, South Africa on diet, physical activity, and obesity-related health within their social and cultural context. Methods Purposeful sampling was used to recruit daughters with a normal body mass index (BMI who have obese mothers. Individual semi-structured in-depth interviews were conducted with 17 daughters (age 24 years and 15 of their mothers in Soweto, South Africa. Interview questions related to: a eating and physical activity behaviors and perceptions, b perceptions of social and community level factors, c cultural beliefs about diet and body image, and d intergenerational relationships. Data were analyzed using four-phases of thematic analysis and the constant comparison approach. Results Daughters and mothers had similar ideas of the definition of healthy food and the importance of eating healthy, but mothers were more likely to report eating healthy because of their age, adverse health experiences, and a desire to live longer. Daughters and mothers engaged in physical activity for reasons related to weight maintenance and feeling better, but mothers reported being more likely to start exercising as a result of a health concern. Daughters and mothers had comparable views of what makes a person healthy. Daughters and mothers relied on each other for food purchasing and food preparation. Conclusion Daughters and mothers shared some similar perceptions of diet, physical activity, and health that were rooted in their daily life in Soweto. However, mothers generally reported being more likely to exhibit healthy eating and physical activity behaviors despite being obese. The mothers may have adopted these perceptions and behaviors later in life linked to ageing

  5. Daughters and mothers exercising together (DAMET): a 12-week pilot project designed to improve physical self-perception and increase recreational physical activity.

    Science.gov (United States)

    Ransdell, L B; Dratt, J; Kennedy, C; O'Neill, S; DeVoe, D

    2001-01-01

    This paper presents the results of a 12-week single-sex, family-based physical activity intervention grounded in Social Cognitive Theory. Mother/daughter pairs and triads (n = 20) attended physical activity and classroom sessions twice weekly. Physiological data (VO2peak, height, and weight), psychological data (physical self-perception profile subscale scores), information about physical activity participation (PAP, d x wk(-1)) and qualitative impressions (QI) of the program were collected pre- and post-intervention. PAP and QI were also collected 6-months after completing the intervention. Although no significant increases in physical activity were reported, significant improvements in perceived sport competence, physical condition, and strength and muscularity were reported over time. The social cognitive theory, as used to plan this physical activity intervention, offered a promising theoretical perspective for facilitating improved physical self-perception in adolescent girls and their mothers.

  6. Visitor Perceptions on the Impacts of Tourism Activities, Development and Infrastructure on the Environment of Perhentian Islands

    Directory of Open Access Journals (Sweden)

    Ramdas M.

    2014-01-01

    Full Text Available Tourism is one of the leading contributors to service industry in Malaysia and is gradually growing. The growth of this industry brings impact towards the environment, specifically islands. This study views into the tourists’ perception on the impact of tourism activities, development and infrastructure to the environment of Perhentian Islands. A total number of 258 questionnaires were distributed to tourists in Perhentian Islands which is a popular tourist island destination in Malaysia. The results indicate that there is a significant number of moderate and high level of agreement that tourism activities, development and infrastructure are effecting the island’s environment. It was also found that foreign tourist had significantly higher level of agreement for both variables than local tourist. However, it was found that there was no significant difference among gender for both variables. Establishing carrying capacity and embedding environmental education in sustainable tourism management would help broaden the perception of tourists.

  7. Spatial Uncertainty Model for Visual Features Using a Kinect™ Sensor

    Directory of Open Access Journals (Sweden)

    Jae-Han Park

    2012-06-01

    Full Text Available This study proposes a mathematical uncertainty model for the spatial measurement of visual features using Kinect™ sensors. This model can provide qualitative and quantitative analysis for the utilization of Kinect™ sensors as 3D perception sensors. In order to achieve this objective, we derived the propagation relationship of the uncertainties between the disparity image space and the real Cartesian space with the mapping function between the two spaces. Using this propagation relationship, we obtained the mathematical model for the covariance matrix of the measurement error, which represents the uncertainty for spatial position of visual features from Kinect™ sensors. In order to derive the quantitative model of spatial uncertainty for visual features, we estimated the covariance matrix in the disparity image space using collected visual feature data. Further, we computed the spatial uncertainty information by applying the covariance matrix in the disparity image space and the calibrated sensor parameters to the proposed mathematical model. This spatial uncertainty model was verified by comparing the uncertainty ellipsoids for spatial covariance matrices and the distribution of scattered matching visual features. We expect that this spatial uncertainty model and its analyses will be useful in various Kinect™ sensor applications.

  8. Spatial uncertainty model for visual features using a Kinect™ sensor.

    Science.gov (United States)

    Park, Jae-Han; Shin, Yong-Deuk; Bae, Ji-Hun; Baeg, Moon-Hong

    2012-01-01

    This study proposes a mathematical uncertainty model for the spatial measurement of visual features using Kinect™ sensors. This model can provide qualitative and quantitative analysis for the utilization of Kinect™ sensors as 3D perception sensors. In order to achieve this objective, we derived the propagation relationship of the uncertainties between the disparity image space and the real Cartesian space with the mapping function between the two spaces. Using this propagation relationship, we obtained the mathematical model for the covariance matrix of the measurement error, which represents the uncertainty for spatial position of visual features from Kinect™ sensors. In order to derive the quantitative model of spatial uncertainty for visual features, we estimated the covariance matrix in the disparity image space using collected visual feature data. Further, we computed the spatial uncertainty information by applying the covariance matrix in the disparity image space and the calibrated sensor parameters to the proposed mathematical model. This spatial uncertainty model was verified by comparing the uncertainty ellipsoids for spatial covariance matrices and the distribution of scattered matching visual features. We expect that this spatial uncertainty model and its analyses will be useful in various Kinect™ sensor applications.

  9. School Nutrition Employees' Perceptions of Farm to School (FTS) Activities Differ Based on Management Type and FTS Participation Length

    Science.gov (United States)

    Kang, Sangwook; Arendt, Susan W.; Stokes, Nathan M.

    2016-01-01

    Purpose: The purpose of this study was to explore school nutrition employees' perceptions of FTS activities and whether the numbers of activities differ based on management type of school foodservice operation and length of FTS participation. Methods: The state with the most FTS programs from each of the eight national FTS regions was selected. A…

  10. Risk perception in the public: Results of a survey

    International Nuclear Information System (INIS)

    Bastide, S.; Brenot, J.

    1989-01-01

    At first, some approaches used to study risk perception are briefly reviewed. Then, results of a survey devoted to general public risk perception, are presented. Risky activities are ranked. Clusters of activities which are judged similar for danger, are given. The relations between perception of danger, trust in the safety organization and the characteristics of the interviewed people are emphasized. The nuclear and chemical sectors are shortly compared. (author)

  11. A comparative study of aroma-active compounds between dark and milk chocolate: relationship to sensory perception.

    Science.gov (United States)

    Liu, Jianbin; Liu, Mengya; He, Congcong; Song, Huanlu; Guo, Jia; Wang, Ye; Yang, Haiying; Su, Xiaoxia

    2015-04-01

    The most important aroma-active compounds of two types of chocolate and cocoa liquor used for their production were analysed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and aroma extract dilution analysis (AEDA). Furthermore, the relationship between odorants and sensory perception of chocolate was measured by quantitative analysis, sensory evaluation and correlation analysis. In addition, some chemicals were added to the original dark or milk chocolate to validate their roles in the aroma property of chocolate. A total of 32 major aroma-active compounds were identified in the chocolate with the flavour dilution factors of 27-729 by AEDA, including seven aldehydes, six pyrazines, three pyrroles, four carboxylic acids, four lactones, two alcohols, two ketones, one ester, one pyrone, one furan and one sulfur-containing compound. Further quantitative analysis showed that dark chocolate had higher contents of pyrazine, pyrrole, carboxylic acids, alcohols and Strecker aldehydes, whereas the concentration of lactones, esters, long chain aldehydes and ketones were higher in the milk type. Differences in volatile composition and descriptive flavour attributes between the dark and milk chocolate were observed. The relationship between aroma-active compounds and sensory perception in the chocolate was verified. © 2014 Society of Chemical Industry.

  12. Positional information generated by spatially distributed signaling cascades.

    Directory of Open Access Journals (Sweden)

    Javier Muñoz-García

    2009-03-01

    Full Text Available The temporal and stationary behavior of protein modification cascades has been extensively studied, yet little is known about the spatial aspects of signal propagation. We have previously shown that the spatial separation of opposing enzymes, such as a kinase and a phosphatase, creates signaling activity gradients. Here we show under what conditions signals stall in the space or robustly propagate through spatially distributed signaling cascades. Robust signal propagation results in activity gradients with long plateaus, which abruptly decay at successive spatial locations. We derive an approximate analytical solution that relates the maximal amplitude and propagation length of each activation profile with the cascade level, protein diffusivity, and the ratio of the opposing enzyme activities. The control of the spatial signal propagation appears to be very different from the control of transient temporal responses for spatially homogenous cascades. For spatially distributed cascades where activating and deactivating enzymes operate far from saturation, the ratio of the opposing enzyme activities is shown to be a key parameter controlling signal propagation. The signaling gradients characteristic for robust signal propagation exemplify a pattern formation mechanism that generates precise spatial guidance for multiple cellular processes and conveys information about the cell size to the nucleus.

  13. Public perception of the activities of the Nuclear Energy and Advanced Technologies Agency of Cuba

    International Nuclear Information System (INIS)

    Contreras, Marta; Arencibia, Alois; Alvarado, Jorge; Garcia, Dulce; Rodriguez, Ingrids; Hernandez, Noslen; Aguilar, Aurora; Perera, Maricela; Rodriguez, Ramon; Alonso, Ivonne; Quintana, Natacha; Cardenas, Juan; Ramos, Odalys; Elias, Lidia Lauren

    2013-01-01

    The work presents the results of a study of perception of the nuclear activities of the Nuclear Energy and Advanced Technologies Agency of Cuba, carried out by means of a study of image. The public object was a wide group of clients, providers, journalists and experts of the governing and regulatory organs which constitute its external public. For the investigation a methodology was prepared with a questionnaire and a semi structured interview, which allowed to obtain complementary information of qualitative character. In general, the perception of the Agency turned out to be positive and the human resources were the best evaluated aspect. Nevertheless, the visibility of the Agency in the public day pupils is considered to be insufficient. The study provided the necessary information so as to design the strategy of communication of the Agency. (author)

  14. Public perception of the activities of the Nuclear Energy and Advanced Technologies Agency of Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Contreras, Marta; Arencibia, Alois; Alvarado, Jorge; Garcia, Dulce; Rodriguez, Ingrids; Hernandez, Noslen [Centro de Gestion de la Informacion y Desarrollo de la Energia (CUBAENERGIA), La Habana (Cuba); Aguilar, Aurora; Perera, Maricela [Centro de Investigaciones Psicologicas y Sociologicas (CIPS), La Habana, (Cuba); Rodriguez, Ramon [Agencia de Energia Nuclear y Tecnologias de Avanzada (AENTA), La Habana, (Cuba); Alonso, Ivonne [Centro Nacional de Seguridad Nuclear (CNSN), La Habana, (Cuba); Quintana, Natacha [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), La Habana, (Cuba); Cardenas, Juan; Ramos, Odalys [Centro de Proteccion e Higiene de las Radiaciones (CPHR), La Habana, (Cuba); Elias, Lidia Lauren [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana, (Cuba)

    2013-07-01

    The work presents the results of a study of perception of the nuclear activities of the Nuclear Energy and Advanced Technologies Agency of Cuba, carried out by means of a study of image. The public object was a wide group of clients, providers, journalists and experts of the governing and regulatory organs which constitute its external public. For the investigation a methodology was prepared with a questionnaire and a semi structured interview, which allowed to obtain complementary information of qualitative character. In general, the perception of the Agency turned out to be positive and the human resources were the best evaluated aspect. Nevertheless, the visibility of the Agency in the public day pupils is considered to be insufficient. The study provided the necessary information so as to design the strategy of communication of the Agency. (author)

  15. Emotion Discrimination using spatially Compact Regions of Interest extracted from Imaging EEG Activity

    Directory of Open Access Journals (Sweden)

    Jorge Ivan Padilla-Buritica

    2016-07-01

    Full Text Available Lately, research on computational models of emotion had been getting much attention due to their potential for understanding the mechanisms of emotions and their promising broad range of applications that potentially bridge the gap between human and machine interactions. We propose a new method for emotion classification that relies on features extracted from those active brain areas that are most likely related to emotions. To this end, we carry out the selection of spatially compact regions of interest that are computed using the brain neural activity reconstructed from electroencephalography data. Throughout this study, we consider three representative feature extraction methods widely applied to emotion detection tasks, including Power spectral density, Wavelet, and Hjorth parameters. Further feature selection is carried out using principal component analysis. For validation purpose, these features are used to feed a support vector machine classifier that is trained under the leave-one-out cross-validation strategy. Obtained results on real affective data show that incorporation of the proposed training method in combination with the enhanced spatial resolution provided by the source estimation allows improving the performed accuracy of discrimination in most of the considered emotions, namely: dominance, valence, and linking.

  16. Estimating perception of scene layout properties from global image features.

    Science.gov (United States)

    Ross, Michael G; Oliva, Aude

    2010-01-08

    The relationship between image features and scene structure is central to the study of human visual perception and computer vision, but many of the specifics of real-world layout perception remain unknown. We do not know which image features are relevant to perceiving layout properties, or whether those features provide the same information for every type of image. Furthermore, we do not know the spatial resolutions required for perceiving different properties. This paper describes an experiment and a computational model that provides new insights on these issues. Humans perceive the global spatial layout properties such as dominant depth, openness, and perspective, from a single image. This work describes an algorithm that reliably predicts human layout judgments. This model's predictions are general, not specific to the observers it trained on. Analysis reveals that the optimal spatial resolutions for determining layout vary with the content of the space and the property being estimated. Openness is best estimated at high resolution, depth is best estimated at medium resolution, and perspective is best estimated at low resolution. Given the reliability and simplicity of estimating the global layout of real-world environments, this model could help resolve perceptual ambiguities encountered by more detailed scene reconstruction schemas.

  17. Towards a neural basis of music perception.

    Science.gov (United States)

    Koelsch, Stefan; Siebel, Walter A

    2005-12-01

    Music perception involves complex brain functions underlying acoustic analysis, auditory memory, auditory scene analysis, and processing of musical syntax and semantics. Moreover, music perception potentially affects emotion, influences the autonomic nervous system, the hormonal and immune systems, and activates (pre)motor representations. During the past few years, research activities on different aspects of music processing and their neural correlates have rapidly progressed. This article provides an overview of recent developments and a framework for the perceptual side of music processing. This framework lays out a model of the cognitive modules involved in music perception, and incorporates information about the time course of activity of some of these modules, as well as research findings about where in the brain these modules might be located.

  18. Discrete capacity limits and neuroanatomical correlates of visual short-term memory for objects and spatial locations.

    Science.gov (United States)

    Konstantinou, Nikos; Constantinidou, Fofi; Kanai, Ryota

    2017-02-01

    Working memory is responsible for keeping information in mind when it is no longer in view, linking perception with higher cognitive functions. Despite such crucial role, short-term maintenance of visual information is severely limited. Research suggests that capacity limits in visual short-term memory (VSTM) are correlated with sustained activity in distinct brain areas. Here, we investigated whether variability in the structure of the brain is reflected in individual differences of behavioral capacity estimates for spatial and object VSTM. Behavioral capacity estimates were calculated separately for spatial and object information using a novel adaptive staircase procedure and were found to be unrelated, supporting domain-specific VSTM capacity limits. Voxel-based morphometry (VBM) analyses revealed dissociable neuroanatomical correlates of spatial versus object VSTM. Interindividual variability in spatial VSTM was reflected in the gray matter density of the inferior parietal lobule. In contrast, object VSTM was reflected in the gray matter density of the left insula. These dissociable findings highlight the importance of considering domain-specific estimates of VSTM capacity and point to the crucial brain regions that limit VSTM capacity for different types of visual information. Hum Brain Mapp 38:767-778, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Socio-Spatial Typology In Karanrang Island

    Directory of Open Access Journals (Sweden)

    Amin Ishak Rahmi

    2018-01-01

    Full Text Available The phenomenon of community life on the small island is influenced by the stimulating factor of harmonious social interaction system through cooperation, kinship, economic activity, children playing, transportation system, religion and other social activities. The social dynamics of small island communities appear in the layout and environment in which they live, how they manage and utilize space, both indoors and outdoors. The purpose of this paper is to describe the socio-spatial typology of settlements on Karanrang Island, including a description of the spatial pattern of communalenvironments. Research approaches through spatial similarities and differences in the classification of behavioral setting, including physical, non-physical, socio-spatial arrangements. Karanrang Island as a research focus which has an area of 7.8 Ha is one of small islands inhabited in cluster PangkajeneIslands (Pangkep South Sulawesi, with characteristic of dense settlement, and diversity of tribe, also inhabited by 434 families. The method of this research is observation, data collection through field survey with descriptive analysis based on empirical data on meso / environment which is divided into:1 inter building space; 2 Space in the building; 3 Open space, and; 4 Environmental facilities. The results showed that classification of socio-spatial typology of communal environment is divided into four types of socio-spatial models based on the configuration of social interaction activities, namely:1 Type of Linear Centripetal, at the inter buildings space; 2 Type of Centripetal Cluster, space on the building; 3 Type of Centrifugal Cluster, at green open space/field; 4 Type of cluster Centripetal, at environmental facilities. The socio-spatial type based on actor’s activities, occupancy, and territory, can be distinguished on: 1 Type of children’s activity; 2 Type of mother’sactivity; 3 Type of father’s activity, and 4 Type of combination activity.

  20. The Parkinson's experience of group physical activity: Understanding social support, social comparison, physical self-perceptions, and posttraumatic growth

    OpenAIRE

    Sheehy, Tammy L

    2014-01-01

    Group physical activity programs for clinical populations can provide opportunities for adaptive social interactions, improving perceptions of competence, and may facilitate posttraumatic growth (positive psychological changes resulting from traumatic life experiences). Therefore, the purpose of this study was to examine how people with Parkinson's experience social interactions and physical challenges in a group physical activity program, and to investigate what role they think those experie...

  1. Enhancing learning with the social media: student teachers’ perceptions on Twitter in a debate activity

    Directory of Open Access Journals (Sweden)

    Gemma Tur

    2015-01-01

    Full Text Available This paper presents research focused on the educational experience of students using the microblogging platform Twitter for debate activities in three groups in different teacher education programmes at the University of the Balearic Islands, Spain. The implementation of this technology-based task in a face-to-face class was introduced as an innovative experience as a way of enhancing student learning and fostering participation in the context of formal learning. The educational objectives of these activities, besides working on the topics of the debate, were to empower student teachers’ Personal Learning Environments, engage student participation and enhance their use of social media and mobile devices for learning. Student perceptions were assessed by means of a questionnaire completed by them at the end of the courses. Tweets related to the debate were also collected in order to obtain some statistical data on student participation. Data collected allowed the researchers to observe student teacher engagement with the use of Twitter for the debate activity and its impact on their learning and understanding of the debate topic. Results also showed positive perceptions towards the use of social media in education and students’ willingness for future use, learning opportunities from Twitter and the use of mobile technology were also envisioned. Finally, conclusions argue the implications for practice of the current study and highlight some issues for further research, such as the exploration of new and innovative uses for teachers’ professional development and the empowerment of new activities and habits in learning on the move.

  2. Racial Differences in Neighborhood Perceptions and their Influences on Physical Activity among Urban Older Women

    Directory of Open Access Journals (Sweden)

    Wenjun Li

    2017-04-01

    Full Text Available Background: Proper levels of physical activity (PA are important to healthy aging. Little is known about racial differences in influences of neighborhood perceptions (NP on PA and use of neighborhood resources among community-dwelling older women. Materials and methods: In 2014 and 2015, 49 white and 44 black women of age 65 and older living in Washington, DC were queried about their PA, NP, use of neighborhood resources and sociodemographic characteristics. They wore an accelerometer and a Global Positioning System device concurrently for 7 consecutive days. Data were analyzed by race. Results: Compared to Whites, Blacks had lower NP scores (71% positive vs. 77%, p = 0.01, lower mean daily step counts (mean (SD: 3256 (1918 vs. 5457 (2989, p < 0.001, and lower frequencies of all exercise activities combined (19.7 (8.7 vs. 25.2 (11.8 per week, p = 0.01. For both Whites and Blacks, better NPs were associated with more frequent PA both at (p = 0.05 and away from home (p = 0.01. However, better NPs were associated with higher frequencies of exercise activities, moderate-to-high intensity activities, and utilitarian walking for Whites but not Blacks (p < 0.05 for race-perception interaction terms. Conclusions: In an urban setting, older Black women were more likely than older White women to have poor NPs, less PA, and weaker or no association of positive NPs with higher levels of certain PAs. Such substantial racial differences warrant further investigation and consideration in health promotion programs.

  3. Spatial attention facilitates assembly of the briefest percepts : Electrophysiological evidence from color fusion

    NARCIS (Netherlands)

    Akyürek, Elkan G.; van Asselt, E. Manon

    2015-01-01

    When two different color stimuli are presented in rapid succession, the resulting percept is sometimes that of a mixture of both colors, due to a perceptual process called color fusion. Although color fusion might seem to occur very early in the visual pathway, and only happens across the briefest

  4. Illness Perceptions and Fatigue in Systemic Vasculitis

    Science.gov (United States)

    Grayson, Peter C.; Amudala, Naomi A.; McAlear, Carol A.; Leduc, Renée L.; Shereff, Denise; Richesson, Rachel; Fraenkel, Liana; Merkel, Peter A.

    2014-01-01

    Objective To compare illness perceptions among patients with different forms of vasculitis, identify risk factors for negative illness perceptions, and determine the association between illness perceptions and fatigue. Methods Participants were recruited from an online registry in vasculitis to complete the revised Illness Perception Questionnaire (IPQ-R). Mean scores on each IPQ-R dimension were compared across types of vasculitis. Cluster analysis and stepwise regression identified predictors of negative illness perception. Fatigue was measured using the general subscale of the Multidimensional Fatigue Inventory (MFI). Patient-reported measures of disease activity and IPQ-R dimensions were assessed in relation to MFI scores using linear regression in sequential, additive models with model-fit comparisons. Results 692 participants with 9 forms of vasculitis completed the IPQ-R. For 6 out of 8 IPQ-R dimensions, there were no significant differences in mean scores between the different vasculitides. Scores in identity and cyclical dimensions were significantly higher in Behçet’s disease compared to other types of vasculitis (13.5 vs 10.7; 4.0 vs 3.2, pvasculitis, and younger age is a risk factor for negative illness perceptions. Illness perceptions explain differences in fatigue scores beyond what can be explained by measures of disease activity. PMID:23861259

  5. Marine spatial planning and Good Environmental Status: a perspective on spatial and temporal dimensions

    Directory of Open Access Journals (Sweden)

    Alison J. Gilbert

    2015-03-01

    Full Text Available The European Union Marine Strategy Framework Directive requires the Good Environmental Status of marine environments in Europe's regional seas; yet, maritime activities, including sources of marine degradation, are diversifying and intensifying in an increasingly globalized world. Marine spatial planning is emerging as a tool for rationalizing competing uses of the marine environment while guarding its quality. A directive guiding the development of such plans by European Union member states is currently being formulated. There is an undeniable need for marine spatial planning. However, we argue that considerable care must be taken with marine spatial planning, as the spatial and temporal scales of maritime activities and of Good Environmental Status may be mismatched. We identify four principles for careful and explicit consideration to align the requirements of the two directives and enable marine spatial planning to support the achievement of Good Environmental Status in Europe's regional seas.

  6. Spatial accessibility to physical activity facilities and to food outlets and overweight in French youth.

    Science.gov (United States)

    Casey, R; Chaix, B; Weber, C; Schweitzer, B; Charreire, H; Salze, P; Badariotti, D; Banos, A; Oppert, J-M; Simon, C

    2012-07-01

    Some characteristics of the built environment have been associated with obesity in youth. Our aim was to determine whether individual and environmental socio-economic characteristics modulate the relation between youth overweight and spatial accessibility to physical activity (PA) facilities and to food outlets. Cross-sectional study. 3293 students, aged 12 ± 0.6 years, randomly selected from eastern France middle schools. Using geographical information systems (GIS), spatial accessibility to PA facilities (urban and nature) was assessed using the distance to PA facilities at the municipality level; spatial accessibility to food outlets (general food outlets, bakeries and fast-food outlets) was calculated at individual level using the student home address and the food outlets addresses. Relations of weight status with spatial accessibility to PA facilities and to food outlets were analysed using mixed logistic models, testing potential direct and interaction effects of individual and environmental socio-economic characteristics. Individual socio-economic status modulated the relation between spatial accessibility to PA facilities and to general food outlets and overweight. The likelihood of being overweight was higher when spatial accessibility to urban PA facilities and to general food outlets was low, but in children of blue-collar-workers only. The odds ratio (OR) (95% confidence interval) for being overweight of blue-collar-workers children compared with non-blue-collar-workers children was 1.76 (1.25-2.49) when spatial accessibility to urban PA facilities was low. This OR was 1.86 (1.20-2.86) when spatial accessibility to general food outlets was low. There was no significant relationship of overweight with either nature PA facilities or other food outlets (bakeries and fast-food outlets). These results indicate that disparities in spatial accessibility to PA facilities and to general food outlets may amplify the risk of overweight in socio

  7. Spatially parallel processing of within-dimension conjunctions.

    Science.gov (United States)

    Linnell, K J; Humphreys, G W

    2001-01-01

    Within-dimension conjunction search for red-green targets amongst red-blue, and blue-green, nontargets is extremely inefficient (Wolfe et al, 1990 Journal of Experimental Psychology: Human Perception and Performance 16 879-892). We tested whether pairs of red-green conjunction targets can nevertheless be processed spatially in parallel. Participants made speeded detection responses whenever a red-green target was present. Across trials where a second identical target was present, the distribution of detection times was compatible with the assumption that targets were processed in parallel (Miller, 1982 Cognitive Psychology 14 247-279). We show that this was not an artifact of response-competition or feature-based processing. We suggest that within-dimension conjunctions can be processed spatially in parallel. Visual search for such items may be inefficient owing to within-dimension grouping between items.

  8. A hierarchical stochastic model for bistable perception.

    Directory of Open Access Journals (Sweden)

    Stefan Albert

    2017-11-01

    Full Text Available Viewing of ambiguous stimuli can lead to bistable perception alternating between the possible percepts. During continuous presentation of ambiguous stimuli, percept changes occur as single events, whereas during intermittent presentation of ambiguous stimuli, percept changes occur at more or less regular intervals either as single events or bursts. Response patterns can be highly variable and have been reported to show systematic differences between patients with schizophrenia and healthy controls. Existing models of bistable perception often use detailed assumptions and large parameter sets which make parameter estimation challenging. Here we propose a parsimonious stochastic model that provides a link between empirical data analysis of the observed response patterns and detailed models of underlying neuronal processes. Firstly, we use a Hidden Markov Model (HMM for the times between percept changes, which assumes one single state in continuous presentation and a stable and an unstable state in intermittent presentation. The HMM captures the observed differences between patients with schizophrenia and healthy controls, but remains descriptive. Therefore, we secondly propose a hierarchical Brownian model (HBM, which produces similar response patterns but also provides a relation to potential underlying mechanisms. The main idea is that neuronal activity is described as an activity difference between two competing neuronal populations reflected in Brownian motions with drift. This differential activity generates switching between the two conflicting percepts and between stable and unstable states with similar mechanisms on different neuronal levels. With only a small number of parameters, the HBM can be fitted closely to a high variety of response patterns and captures group differences between healthy controls and patients with schizophrenia. At the same time, it provides a link to mechanistic models of bistable perception, linking the group

  9. A hierarchical stochastic model for bistable perception.

    Science.gov (United States)

    Albert, Stefan; Schmack, Katharina; Sterzer, Philipp; Schneider, Gaby

    2017-11-01

    Viewing of ambiguous stimuli can lead to bistable perception alternating between the possible percepts. During continuous presentation of ambiguous stimuli, percept changes occur as single events, whereas during intermittent presentation of ambiguous stimuli, percept changes occur at more or less regular intervals either as single events or bursts. Response patterns can be highly variable and have been reported to show systematic differences between patients with schizophrenia and healthy controls. Existing models of bistable perception often use detailed assumptions and large parameter sets which make parameter estimation challenging. Here we propose a parsimonious stochastic model that provides a link between empirical data analysis of the observed response patterns and detailed models of underlying neuronal processes. Firstly, we use a Hidden Markov Model (HMM) for the times between percept changes, which assumes one single state in continuous presentation and a stable and an unstable state in intermittent presentation. The HMM captures the observed differences between patients with schizophrenia and healthy controls, but remains descriptive. Therefore, we secondly propose a hierarchical Brownian model (HBM), which produces similar response patterns but also provides a relation to potential underlying mechanisms. The main idea is that neuronal activity is described as an activity difference between two competing neuronal populations reflected in Brownian motions with drift. This differential activity generates switching between the two conflicting percepts and between stable and unstable states with similar mechanisms on different neuronal levels. With only a small number of parameters, the HBM can be fitted closely to a high variety of response patterns and captures group differences between healthy controls and patients with schizophrenia. At the same time, it provides a link to mechanistic models of bistable perception, linking the group differences to

  10. Spatial Frequency Requirements and Gaze Strategy in Visual-Only and Audiovisual Speech Perception

    Science.gov (United States)

    Wilson, Amanda H.; Alsius, Agnès; Parè, Martin; Munhall, Kevin G.

    2016-01-01

    Purpose: The aim of this article is to examine the effects of visual image degradation on performance and gaze behavior in audiovisual and visual-only speech perception tasks. Method: We presented vowel-consonant-vowel utterances visually filtered at a range of frequencies in visual-only, audiovisual congruent, and audiovisual incongruent…

  11. The regulation of ant colony foraging activity without spatial information.

    Directory of Open Access Journals (Sweden)

    Balaji Prabhakar

    Full Text Available Many dynamical networks, such as the ones that produce the collective behavior of social insects, operate without any central control, instead arising from local interactions among individuals. A well-studied example is the formation of recruitment trails in ant colonies, but many ant species do not use pheromone trails. We present a model of the regulation of foraging by harvester ant (Pogonomyrmex barbatus colonies. This species forages for scattered seeds that one ant can retrieve on its own, so there is no need for spatial information such as pheromone trails that lead ants to specific locations. Previous work shows that colony foraging activity, the rate at which ants go out to search individually for seeds, is regulated in response to current food availability throughout the colony's foraging area. Ants use the rate of brief antennal contacts inside the nest between foragers returning with food and outgoing foragers available to leave the nest on the next foraging trip. Here we present a feedback-based algorithm that captures the main features of data from field experiments in which the rate of returning foragers was manipulated. The algorithm draws on our finding that the distribution of intervals between successive ants returning to the nest is a Poisson process. We fitted the parameter that estimates the effect of each returning forager on the rate at which outgoing foragers leave the nest. We found that correlations between observed rates of returning foragers and simulated rates of outgoing foragers, using our model, were similar to those in the data. Our simple stochastic model shows how the regulation of ant colony foraging can operate without spatial information, describing a process at the level of individual ants that predicts the overall foraging activity of the colony.

  12. Human Perception of Ambiguous Inertial Motion Cues

    Science.gov (United States)

    Zhang, Guan-Lu

    2010-01-01

    Human daily activities on Earth involve motions that elicit both tilt and translation components of the head (i.e. gazing and locomotion). With otolith cues alone, tilt and translation can be ambiguous since both motions can potentially displace the otolithic membrane by the same magnitude and direction. Transitions between gravity environments (i.e. Earth, microgravity and lunar) have demonstrated to alter the functions of the vestibular system and exacerbate the ambiguity between tilt and translational motion cues. Symptoms of motion sickness and spatial disorientation can impair human performances during critical mission phases. Specifically, Space Shuttle landing records show that particular cases of tilt-translation illusions have impaired the performance of seasoned commanders. This sensorimotor condition is one of many operational risks that may have dire implications on future human space exploration missions. The neural strategy with which the human central nervous system distinguishes ambiguous inertial motion cues remains the subject of intense research. A prevailing theory in the neuroscience field proposes that the human brain is able to formulate a neural internal model of ambiguous motion cues such that tilt and translation components can be perceptually decomposed in order to elicit the appropriate bodily response. The present work uses this theory, known as the GIF resolution hypothesis, as the framework for experimental hypothesis. Specifically, two novel motion paradigms are employed to validate the neural capacity of ambiguous inertial motion decomposition in ground-based human subjects. The experimental setup involves the Tilt-Translation Sled at Neuroscience Laboratory of NASA JSC. This two degree-of-freedom motion system is able to tilt subjects in the pitch plane and translate the subject along the fore-aft axis. Perception data will be gathered through subject verbal reports. Preliminary analysis of perceptual data does not indicate that

  13. Patients' perceptions of physical activity before and after joint replacement: a systematic review with meta-ethnographic analysis.

    Science.gov (United States)

    Smith, Toby O; Latham, Sarah; Maskrey, Vivienne; Blyth, Annie

    2015-09-01

    It has been perceived that people following total hip arthroplasty (THA) or total knee arthroplasty (TKA) have the capability, with reduced pain, to increase their levels of physical activity. To determine the attitudes and perceptions of people awaiting or having undergone THA or TKA to physical activity post-arthroplasty and to identify potential facilitators or barriers to engage in active living and physical activity pursuits. Systematic review of published and unpublished databases was undertaken from their inception to November 2014. Studies exploring the attitudes and perceptions of people awaiting or having undergone THA or TKA to physical activity post-arthroplasty were included. Data were analysed through a meta-ethnography approach. From 528 citations, 13 papers were eligible, sampling 282 people post-THA or TKA. The literature was judged moderate to high quality. Following THA and TKA, people either wished to return to their pre-pathology level of physical activity or simply be able to engage in less physically demanding activities that are meaningful to them and their lifestyles. Barriers to engaging in higher levels of physical activity were largely related to limited information, which culminated in fear surrounding 'doing the right thing' both for individual's recovery and the longevity of the joint replacement. While many people post-THA or TKA wish to return to pre-pathological physical activity status, there is limited interest in actually undertaking greater levels of physical activity post-arthroplasty either for pleasure or health gains. Improvement in education and awareness of this may be key drivers to improve habitualisation of physical activity post-arthroplasty. CRD42014014995. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. City of Zagreb Spatial Data Infrastructure

    Directory of Open Access Journals (Sweden)

    Darko Šiško

    2011-12-01

    Full Text Available Through the establishment of the Coordination Group for the City of Zagreb Spatial Management IT System, the City of Zagreb has become actively involved in the wider global community by setting up the Zagreb Spatial Data Infrastructure (ZSDI service. In the City of Zagreb, many bodies of city administration use and create spatial data and services daily in their work. All are ZSDI users and obviously have to make data mutually available. Without spatial data and services, it would be impossible to manage space effectively, plan city development, monitor the situation on the ground, or carry out many other activities. This paper gives an overview of ZSDI set-up activities so far, as well as plans for the future. 

  15. The Impact of Early Visual Deprivation on Spatial Hearing: A Comparison between Totally and Partially Visually Deprived Children

    Science.gov (United States)

    Cappagli, Giulia; Finocchietti, Sara; Cocchi, Elena; Gori, Monica

    2017-01-01

    The specific role of early visual deprivation on spatial hearing is still unclear, mainly due to the difficulty of comparing similar spatial skills at different ages and to the difficulty in recruiting young blind children from birth. In this study, the effects of early visual deprivation on the development of auditory spatial localization have been assessed in a group of seven 3–5 years old children with congenital blindness (n = 2; light perception or no perception of light) or low vision (n = 5; visual acuity range 1.1–1.7 LogMAR), with the main aim to understand if visual experience is fundamental to the development of specific spatial skills. Our study led to three main findings: firstly, totally blind children performed overall more poorly compared sighted and low vision children in all the spatial tasks performed; secondly, low vision children performed equally or better than sighted children in the same auditory spatial tasks; thirdly, higher residual levels of visual acuity are positively correlated with better spatial performance in the dynamic condition of the auditory localization task indicating that the more residual vision the better spatial performance. These results suggest that early visual experience has an important role in the development of spatial cognition, even when the visual input during the critical period of visual calibration is partially degraded like in the case of low vision children. Overall these results shed light on the importance of early assessment of spatial impairments in visually impaired children and early intervention to prevent the risk of isolation and social exclusion. PMID:28443040

  16. Sensory adaptation for timing perception.

    Science.gov (United States)

    Roseboom, Warrick; Linares, Daniel; Nishida, Shin'ya

    2015-04-22

    Recent sensory experience modifies subjective timing perception. For example, when visual events repeatedly lead auditory events, such as when the sound and video tracks of a movie are out of sync, subsequent vision-leads-audio presentations are reported as more simultaneous. This phenomenon could provide insights into the fundamental problem of how timing is represented in the brain, but the underlying mechanisms are poorly understood. Here, we show that the effect of recent experience on timing perception is not just subjective; recent sensory experience also modifies relative timing discrimination. This result indicates that recent sensory history alters the encoding of relative timing in sensory areas, excluding explanations of the subjective phenomenon based only on decision-level changes. The pattern of changes in timing discrimination suggests the existence of two sensory components, similar to those previously reported for visual spatial attributes: a lateral shift in the nonlinear transducer that maps relative timing into perceptual relative timing and an increase in transducer slope around the exposed timing. The existence of these components would suggest that previous explanations of how recent experience may change the sensory encoding of timing, such as changes in sensory latencies or simple implementations of neural population codes, cannot account for the effect of sensory adaptation on timing perception.

  17. Criterion-free measurement of motion transparency perception at different speeds

    Science.gov (United States)

    Rocchi, Francesca; Ledgeway, Timothy; Webb, Ben S.

    2018-01-01

    Transparency perception often occurs when objects within the visual scene partially occlude each other or move at the same time, at different velocities across the same spatial region. Although transparent motion perception has been extensively studied, we still do not understand how the distribution of velocities within a visual scene contribute to transparent perception. Here we use a novel psychophysical procedure to characterize the distribution of velocities in a scene that give rise to transparent motion perception. To prevent participants from adopting a subjective decision criterion when discriminating transparent motion, we used an “odd-one-out,” three-alternative forced-choice procedure. Two intervals contained the standard—a random-dot-kinematogram with dot speeds or directions sampled from a uniform distribution. The other interval contained the comparison—speeds or directions sampled from a distribution with the same range as the standard, but with a notch of different widths removed. Our results suggest that transparent motion perception is driven primarily by relatively slow speeds, and does not emerge when only very fast speeds are present within a visual scene. Transparent perception of moving surfaces is modulated by stimulus-based characteristics, such as the separation between the means of the overlapping distributions or the range of speeds presented within an image. Our work illustrates the utility of using objective, forced-choice methods to reveal the mechanisms underlying motion transparency perception. PMID:29614154

  18. Re-examining the automaticity and directionality of the activation of the spatial-valence "good is up" metaphoric association.

    Directory of Open Access Journals (Sweden)

    Yanli Huang

    Full Text Available According to the Conceptual Metaphor Theory, people understand abstract concepts depending on the activation of more concrete concepts, but not vice versa. The present research aims to investigate the role of directionality and automaticity regarding the activation of the conceptual metaphor "good is up". Experiment 1 tested the automaticity of the spatial-to-valence metaphoric congruency effect by having participants judge the valence of a positive or negative word that appeared either at the top or at the bottom of the screen. They performed the task concurrently with a 6-digit verbal rehearsal task in the working-memory-load (WML blocks and without this task in the non-WML blocks. The spatial-to-valence metaphoric congruency effect occurred for the positive words in the non-WML blocks (i.e., positive words are judged more quickly when they appeared at the top than at the bottom of the screen, but not in the WML blocks, suggesting that this metaphoric association might not be activated automatically. Experiments 2-6 investigated the valence-to-spatial metaphoric association and its automaticity. Participants processed a positive or negative prime, which appeared at the center of the screen, and then identified a letter (p/q that subsequently appeared at the top or bottom of the screen. The valence-to-spatial metaphoric congruency effect did not occur in the WML (6-digit verbal rehearsal or non-WML blocks, whether response modality to the prime was key-press or vocal, or whether the prime was a word or a picture. The effect only unexpectedly occurred when the task was simultaneously performed with a 4-dot-position visuospatial rehearsal task. Nevertheless, the data collapsed across multiple experiments showed a null valence-to-spatial metaphoric congruency effect, suggesting the absence of the valence-to-spatial metaphoric association in general. The implications of the current findings for the Conceptual Metaphor Theory and its alternatives

  19. Japanese EFL Teachers' Perceptions of Communicative, Audiolingual and Yakudoku Activities

    Directory of Open Access Journals (Sweden)

    Greta Gorsuch

    2001-03-01

    Full Text Available In recent years, the learning of English as a Foreign Language in Japanese high schools has become the focus of new educational policies applied at the national level. One of these is The Course of Study issue by the Ministry of Education, in which teachers are, for the first time in a long series of curriculum guidelines, adjured to develop students' "positive attitudes towards communicating in English." Another is the JET program, which has put thousands of native English speaking assistant language teachers (ALTs into Japanese secondary classrooms for the purpose of team teaching with Japanese teachers. Data resulting from a survey project of 876 Japanese high school English teachers was used to provide empirical evidence of teachers' levels of approval of communicative, audiolingual and traditional (yakudoku activities. Teachers were also asked to rate the strengths of a variety of influences on their instruction, including university entrance exams, and pre- and in-service teacher education programs. Teachers' perceptions of both activities and instructional influences were examined in light of teachers' length of career, type of school (private versus public, academic versus vocational, and level of contact with an ALT. The data revealed the complexities of imposing broad, national educational policies on a diverse group of teachers, and in an educational culture which likely precludes teachers' use of communicative activities.

  20. The role of working memory in spatial S-R correspondence effects.

    Science.gov (United States)

    Wühr, Peter; Biebl, Rupert

    2011-04-01

    This study investigates the impact of working memory (WM) load on response conflicts arising from spatial (non) correspondence between irrelevant stimulus location and response location (Simon effect). The dominant view attributes the Simon effect to automatic processes of location-based response priming. The automaticity view predicts insensitivity of the Simon effect to manipulations of processing load. Four experiments investigated the role of spatial and verbal WM in horizontal and vertical Simon tasks by using a dual-task approach. Participants maintained different amounts of spatial or verbal information in WM while performing a horizontal or vertical Simon task. Results showed that high load generally decreased, and sometimes eliminated, the Simon effect. It is interesting to note that spatial load had a larger impact than verbal load on the horizontal Simon effect, whereas verbal load had a larger impact than spatial load on the vertical Simon effect. The results highlight the role of WM as the perception-action interface in choice-response tasks. Moreover, the results suggest spatial coding of horizontal stimulus-response (S-R) tasks, and verbal coding of vertical S-R tasks.

  1. Recent developments in spatial analysis spatial statistics, behavioural modelling, and computational intelligence

    CERN Document Server

    Getis, Arthur

    1997-01-01

    In recent years, spatial analysis has become an increasingly active field, as evidenced by the establishment of educational and research programs at many universities. Its popularity is due mainly to new technologies and the development of spatial data infrastructures. This book illustrates some recent developments in spatial analysis, behavioural modelling, and computational intelligence. World renown spatial analysts explain and demonstrate their new and insightful models and methods. The applications are in areas of societal interest such as the spread of infectious diseases, migration behaviour, and retail and agricultural location strategies. In addition, there is emphasis on the uses of new technologoies for the analysis of spatial data through the application of neural network concepts.

  2. Where Is the Square? Activities to Stimulate Spatial Reasoning

    Science.gov (United States)

    Obara, Samuel

    2013-01-01

    The National Council of Teachers of Mathematics (NCTM, 1989, 2000) and the new "Australian Curriculum: Mathematics" for senior secondary (ACARA, 2010) highlight the importance of teaching spatial reasoning as early as preschool when mathematics is introduced. Studies have shown that there is a relationship between spatial abilities and…

  3. Identifying barriers to remaining physically active after rehabilitation: differences in perception between physical therapists and older adult patients.

    Science.gov (United States)

    Zalewski, Kathryn; Alt, Carlynn; Arvinen-Barrow, Monna

    2014-06-01

    Cross-sectional study. To describe readiness for change and barriers to physical activity in older adults and to contrast perceptions of physical therapists and patients using the Barriers to Being Active Quiz. Regular physical activity is vital to recovery after discharge from physical therapy. Physical therapists are positioned to support change in physical activity habits for those transitioning to home care. Understanding of readiness for change and barriers to physical activity could optimize recovery. Thirteen physical therapists enrolled in the study and invited patients who met the inclusion criteria to enroll (79 patients enrolled). The physical therapists provided the ICD-9 code, the physical therapist diagnosis, and completed the Barriers to Being Active Quiz as they perceived their patients would. The enrolled patients provided demographics and filled out the Satisfaction With Life Scale, the stages-of-change scale for physical activity, and the Barriers to Being Active Quiz. Patients were predominantly in the early stages of readiness for change. Both patients and physical therapists identified lack of willpower as the primary barrier to physical activity. Patients identified lack of willpower and social influence as critical barriers more often than physical therapists, whereas physical therapists identified fear of injury and lack of time more often than their patients did. Differences between physical therapists and their patients were noted for fear of injury (z = 2.66, P = .008) and lack of time (z = 3.46, P = .001). The stage of change for physical activity impacted perception of social influence (χ2 = 9.64, Pbarriers to physical activity may allow physical therapists to better tailor intervention strategies to impact physical activity behavior change.

  4. Active Learning Environments with Robotic Tangibles: Children's Physical and Virtual Spatial Programming Experiences

    Science.gov (United States)

    Burleson, Winslow S.; Harlow, Danielle B.; Nilsen, Katherine J.; Perlin, Ken; Freed, Natalie; Jensen, Camilla Nørgaard; Lahey, Byron; Lu, Patrick; Muldner, Kasia

    2018-01-01

    As computational thinking becomes increasingly important for children to learn, we must develop interfaces that leverage the ways that young children learn to provide opportunities for them to develop these skills. Active Learning Environments with Robotic Tangibles (ALERT) and Robopad, an analogous on-screen virtual spatial programming…

  5. [Spatial organization of bioelectrical brain activity in epilepsy and amenorrhea of central genesis].

    Science.gov (United States)

    Avakian, G N; Oleĭnikova, O M; Nerobkova, L N; Dovletkhanova, E R; Mitrofanov, A A; Gusev, E I

    2002-01-01

    The study aimed at modification of co-herent analysis (CA), as a mathematical method for EEG data processing for objective evaluation of bioelectric brain activity spatial organization in women with epilepsy and secondary amenorrhea of central genesis. One hundred sixty one women (30 with epilepsy, 116 with amenorrhea and 115 controls aged 15 to 41 years) have been examined. Characteristic changes of cortico-cortical inter- and intra-hemisphere relations for patients with catamenial (CTM) and noncatamenial (NCTM) epilepsy in different menstrual cycle terms were found. The most distinct changes were detected in theta-activity analysis. In the beginning of menstrual cycle, the patients with CTM epilepsy exhibited higher CA indices in theta-rhythm range in all right hemisphere pairs studied. On the contrary, patients with NCTM epilepsy exhibited lower CA indices mainly in the right brain hemisphere. alpha-rhythm spatial organization analysis in the same patients showed similar correlations, but they were better expressed in alpha-rhythm generation zone: in the beginning of menstrual cycle CA indices were high in patients with CTM epilepsy and low in those with NCTM epilepsy. Comparing to controls, patients with secondary amenorrhea of central genesis showed most distinct changes in theta-activity towards the CA indices increase in the majority of the leads. In patients with epilepsy and amenorrhea, CA indices of right brain hemisphere and intra-central temporal lead pairs were lower than in patients with amenorrhea without epilepsy by both alpha- and theta-rhythms.

  6. Cortical dynamics of three-dimensional figure-ground perception of two-dimensional pictures.

    Science.gov (United States)

    Grossberg, S

    1997-07-01

    This article develops the FACADE theory of 3-dimensional (3-D) vision and figure-ground separation to explain data concerning how 2-dimensional pictures give rise to 3-D percepts of occluding and occluded objects. The model describes how geometrical and contrastive properties of a picture can either cooperate or compete when forming the boundaries and surface representation that subserve conscious percepts. Spatially long-range cooperation and spatially short-range competition work together to separate the boundaries of occluding figures from their occluded neighbors. This boundary ownership process is sensitive to image T junctions at which occluded figures contact occluding figures. These boundaries control the filling-in of color within multiple depth-sensitive surface representations. Feedback between surface and boundary representations strengthens consistent boundaries while inhibiting inconsistent ones. Both the boundary and the surface representations of occluded objects may be amodally completed, while the surface representations of unoccluded objects become visible through modal completion. Functional roles for conscious modal and amodal representations in object recognition, spatial attention, and reaching behaviors are discussed. Model interactions are interpreted in terms of visual, temporal, and parietal cortices.

  7. Integrated circuit-based electrochemical sensor for spatially resolved detection of redox-active metabolites in biofilms.

    Science.gov (United States)

    Bellin, Daniel L; Sakhtah, Hassan; Rosenstein, Jacob K; Levine, Peter M; Thimot, Jordan; Emmett, Kevin; Dietrich, Lars E P; Shepard, Kenneth L

    2014-01-01

    Despite advances in monitoring spatiotemporal expression patterns of genes and proteins with fluorescent probes, direct detection of metabolites and small molecules remains challenging. A technique for spatially resolved detection of small molecules would benefit the study of redox-active metabolites that are produced by microbial biofilms and can affect their development. Here we present an integrated circuit-based electrochemical sensing platform featuring an array of working electrodes and parallel potentiostat channels. 'Images' over a 3.25 × 0.9 mm(2) area can be captured with a diffusion-limited spatial resolution of 750 μm. We demonstrate that square wave voltammetry can be used to detect, identify and quantify (for concentrations as low as 2.6 μM) four distinct redox-active metabolites called phenazines. We characterize phenazine production in both wild-type and mutant Pseudomonas aeruginosa PA14 colony biofilms, and find correlations with fluorescent reporter imaging of phenazine biosynthetic gene expression.

  8. Escitalopram Ameliorates Tau Hyperphosphorylation and Spatial Memory Deficits Induced by Protein Kinase A Activation in Sprague Dawley Rats.

    Science.gov (United States)

    Ren, Qing-Guo; Wang, Yan-Juan; Gong, Wei-Gang; Xu, Lin; Zhang, Zhi-Jun

    2015-01-01

    Here, we investigated the effect of escitalopram pretreatment on protein kinase A (PKA)-induced tau hyperphosphorylation and spatial memory deficits in rats using western blot and behavioral tests, respectively. We demonstrated that escitalopram effectively ameliorated tau hyperphosphorylation and the spatial memory deficits induced by PKA activation. We measured the total and activity-dependent Ser9-phosphorylated levels of glycogen synthase kinase (GSK)-3β in hippocampal extracts. No significant change in the total level of GSK-3β was observed between the different groups. However, compared with forskolin injection alone, pretreatment with escitalopram increased the level of Ser9-phosphorylated GSK-3β. We also demonstrated that escitalopram increased Akt phosphorylation at Ser473 (the active form of Akt). Furthermore, we identified other important kinases and phosphatases, such as protein phosphatase 2A, extracellular signal-regulated kinases 1 and 2, and MAP kinase kinase-1/2, that have previously been reported to play a crucial role in tau phosphorylation; however, we did not detect any significant change in the activation of these kinases or phosphatases in our study. We unexpectedly demonstrated that forskolin caused anxiety-like behavior in rats, and pretreatment with escitalopram did not significantly ameliorate the anxiety-like behavior induced by forskolin. These data provide the first evidence that escitalopram ameliorates forskolin-induced tau hyperphosphorylation and spatial memory impairment in rats; these effects do not occur via the anti-anxiety activity of escitalopram but may involve the Akt/GSK-3β signaling pathway.

  9. Perception of nuclear risks

    International Nuclear Information System (INIS)

    Brenot, J.; Bonnefous, S.; Hubert, Ph.

    1996-01-01

    Many factors are involved in the perception of a risk by individuals. Some are individual related (psychology, knowledge, experience), others describe the social environment (culture, ideology), others at end precise the nature of the risk. The word risk has various meanings and is understood differently by the three main categories involved in risk management, that is engineers, administrators and lay public. Several models which describe the perception phenomenon are presented. The dimensions affecting perception are listed. Based on public opinion poll data, a risk taxonomy is proposed, perceived nuclear risks are compared with other risks, and results are given concerning trust in the information diffused and the credibility of those in charge of nuclear activities. (author)

  10. Chronic exposure to glufosinate-ammonium induces spatial memory impairments, hippocampal MRI modifications and glutamine synthetase activation in mice.

    Science.gov (United States)

    Calas, André-Guilhem; Richard, Olivier; Même, Sandra; Beloeil, Jean-Claude; Doan, Bich-Thuy; Gefflaut, Thierry; Même, William; Crusio, Wim E; Pichon, Jacques; Montécot, Céline

    2008-07-01

    Glufosinate-ammonium (GLA), the active compound of a worldwide-used herbicide, acts by inhibiting the plant glutamine synthetase (GS) leading to a lethal accumulation of ammonia. GS plays a pivotal role in the mammalian brain where it allows neurotransmitter glutamate recycling within astroglia. Clinical studies report that an acute GLA ingestion induces convulsions and memory impairment in humans. Toxicological studies performed at doses used for herbicidal activity showed that GLA is probably harmless at short or medium range periods. However, effects of low doses of GLA on chronically exposed subjects are not known. In our study, C57BL/6J mice were treated during 10 weeks three times a week with 2.5, 5 and 10mg/kg of GLA. Effects of this chronic treatment were assessed at behavioral, structural and metabolic levels by using tests of spatial memory, locomotor activity and anxiety, hippocampal magnetic resonance imaging (MRI) texture analysis, and hippocampal GS activity assay, respectively. Chronic GLA treatments have effects neither on anxiety nor on locomotor activity of mice but at 5 and 10mg/kg induce (1) mild memory impairments, (2) a modification of hippocampal texture and (3) a significant increase in hippocampal GS activity. It is suggested that these modifications may be causally linked one to another. Since glutamate is the main neurotransmitter in hippocampus where it plays a crucial role in spatial memory, hippocampal MRI texture and spatial memory alterations might be the consequences of hippocampal glutamate homeostasis modification revealed by increased GS activity in hippocampus. The present study provides the first data that show cerebral alterations after chronic exposure to GLA.

  11. Perception without self-matching in conditional tag based cooperation.

    Science.gov (United States)

    McAvity, David M; Bristow, Tristen; Bunker, Eric; Dreyer, Alex

    2013-09-21

    We consider a model for the evolution of cooperation in a population where individuals may have one of a number of different heritable and distinguishable markers or tags. Individuals interact with each of their neighbors on a square lattice by either cooperating by donating some benefit at a cost to themselves or defecting by doing nothing. The decision to cooperate or defect is contingent on each individual's perception of its interacting partner's tag. Unlike in other tag-based models individuals do not compare their own tag to that of their interaction partner. That is, there is no self-matching. When perception is perfect the cooperation rate is substantially higher than in the usual spatial prisoner's dilemma game when the cost of cooperation is high. The enhancement in cooperation is positively correlated with the number of different tags. The more diverse a population is the more cooperative it becomes. When individuals start with an inability to perceive tags the population evolves to a state where individuals gain at least partial perception. With some reproduction mechanisms perfect perception evolves, but with others the ability to perceive tags is imperfect. We find that perception of tags evolves to lower levels when the cost of cooperation is higher. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Visual-vestibular cue integration for heading perception: applications of optimal cue integration theory.

    Science.gov (United States)

    Fetsch, Christopher R; Deangelis, Gregory C; Angelaki, Dora E

    2010-05-01

    The perception of self-motion is crucial for navigation, spatial orientation and motor control. In particular, estimation of one's direction of translation, or heading, relies heavily on multisensory integration in most natural situations. Visual and nonvisual (e.g., vestibular) information can be used to judge heading, but each modality alone is often insufficient for accurate performance. It is not surprising, then, that visual and vestibular signals converge frequently in the nervous system, and that these signals interact in powerful ways at the level of behavior and perception. Early behavioral studies of visual-vestibular interactions consisted mainly of descriptive accounts of perceptual illusions and qualitative estimation tasks, often with conflicting results. In contrast, cue integration research in other modalities has benefited from the application of rigorous psychophysical techniques, guided by normative models that rest on the foundation of ideal-observer analysis and Bayesian decision theory. Here we review recent experiments that have attempted to harness these so-called optimal cue integration models for the study of self-motion perception. Some of these studies used nonhuman primate subjects, enabling direct comparisons between behavioral performance and simultaneously recorded neuronal activity. The results indicate that humans and monkeys can integrate visual and vestibular heading cues in a manner consistent with optimal integration theory, and that single neurons in the dorsal medial superior temporal area show striking correlates of the behavioral effects. This line of research and other applications of normative cue combination models should continue to shed light on mechanisms of self-motion perception and the neuronal basis of multisensory integration.

  13. Perception of Natural Hazards and Risk among University of Washington Students

    Science.gov (United States)

    Herr, K.; Brand, B.; Hamlin, N.; Ou, J.; Thomas, B.; Tudor, E.

    2012-12-01

    Familiarity with a given population's perception of natural hazards and the threats they present is vital for the development of effective education prior to and emergency management response after a natural event. While much work has been done in other active tectonic regions, perception of natural hazards and risk among Pacific Northwest (PNW) residents is poorly constrained. The objective of this work is to assess the current perception of earthquake and volcanic hazards and risk in the PNW, and to better understand the factors which drive the public's behavior concerning preparedness and response. We developed a survey to assess the knowledge of natural hazards common to the region, their perception of risk concerning these hazards, and their level of preparedness should a natural hazard occur. The survey was distributed to University of Washington students and employees via an internet link as part of a class project in 'Living with Volcanoes' (ESS 106) in March of 2012, which returned more than 900 responses. The UW student population was chosen as our first "population" to assess because of their uniqueness as a large, semi-transient population (typical residence of less than 5 years). Only 50% of participants correctly reported their proximity to an active volcano, indicating either lack of knowledge of active volcanoes in the region or poor spatial awareness. When asked which area were most at risk to lahars, respondents indicated that all areas close to the hazard source, including topographically elevated regions, were at a higher risk than more distal and low-lying localities that are also at high risk, indicating a lack of knowledge concerning the topographic dependency of this hazard. Participants perceived themselves to be able to cope better with an earthquake than a volcanic event. This perception may be due to lack of knowledge of volcanic hazards and their extent or due to a false sense of security concerning earthquakes fostered by regular

  14. An Examination of Police Officers' Perceptions of Effective School Responses to Active Shooter Scenarios: A Phenomenological Narrative Study

    Science.gov (United States)

    Adkins, Florence E.

    2015-01-01

    This qualitative phenomenological research study used narrative inquiry to examine police officer perceptions of effective school responses to active shooting scenarios. Creswell's (2013) six step process for analyzing and interpreting qualitative data was used to examine the interview information. The study results support the idea that changes…

  15. Frontoparietal cortex mediates perceptual transitions in bistable perception.

    Science.gov (United States)

    Weilnhammer, Veith A; Ludwig, Karin; Hesselmann, Guido; Sterzer, Philipp

    2013-10-02

    During bistable vision, perception oscillates between two mutually exclusive percepts despite constant sensory input. Greater BOLD responses in frontoparietal cortex have been shown to be associated with endogenous perceptual transitions compared with "replay" transitions designed to closely match bistability in both perceptual quality and timing. It has remained controversial, however, whether this enhanced activity reflects causal influences of these regions on processing at the sensory level or, alternatively, an effect of stimulus differences that result in, for example, longer durations of perceptual transitions in bistable perception compared with replay conditions. Using a rotating Lissajous figure in an fMRI experiment on 15 human participants, we controlled for potential confounds of differences in transition duration and confirmed previous findings of greater activity in frontoparietal areas for transitions during bistable perception. In addition, we applied dynamic causal modeling to identify the neural model that best explains the observed BOLD signals in terms of effective connectivity. We found that enhanced activity for perceptual transitions is associated with a modulation of top-down connectivity from frontal to visual cortex, thus arguing for a crucial role of frontoparietal cortex in perceptual transitions during bistable perception.

  16. Rocking or rolling--perception of ambiguous motion after returning from space.

    Directory of Open Access Journals (Sweden)

    Gilles Clément

    Full Text Available The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the low-frequency range (i.e., at about 0.3 Hz where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1-2 days. During dynamic linear acceleration (0.15-0.6 Hz, ±1.7 m/s2 perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore-aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions.

  17. Psychological Perception of Space and Time in the Historical Process

    Directory of Open Access Journals (Sweden)

    Konstantin V. Minyar-Beloruchev

    2015-06-01

    Full Text Available The paper is devoted to psychological aspects and psychological perception of spatial and temporal dimensions of the historical process. Space and time do not exist separately, they are closely interconnected: everything that happens in history has certain spatial and temporal position. From historical perspective spatial characteristics of a particular territory are twofold: territory’s psychical position remains unperturbed, while its political status and national affiliation are revised in the course of time. Territories vary in their value: the most valuable objects of physical environment such as sea-coasts, courses and estuaries of rivers, mineral deposits, industrial regions, etc. serve as objects of contention on the international arena, while areas that do not possess such characteristics can be of no interest to international actors. Historical time does not necessarily coincide with chronological time. For example, according to Eric Hobsbawm, the so-called long Nineteenth Century lasted from 1789 to 1914, while the short Twentieth Century lasted only from 1914 to 1991. Psychological time should also be taken into account – perception of relation between past, present, and future developments, as well as perception of chronological intervals within which certain historical developments take place. Time sets chronological framework for the historical process, it can be both cyclical and linear at the same time. Progress in transportation and communication leads to the situation where linear characteristics of space and time remain the same, while space compresses and time accelerates: movement of physical objects and information transfer take less and less time. Such process was ushered in during the Nineteenth Century (Transportation and Communication Revolutions and it accelerated in the Twentieth and Twenty-First Centuries. Present wars can last only months and days, not years; negotiations are conducted directly by chief

  18. Oscillatory activity reflects differential use of spatial reference frames by sighted and blind individuals in tactile attention.

    Science.gov (United States)

    Schubert, Jonathan T W; Buchholz, Verena N; Föcker, Julia; Engel, Andreas K; Röder, Brigitte; Heed, Tobias

    2015-08-15

    Touch can be localized either on the skin in anatomical coordinates, or, after integration with posture, in external space. Sighted individuals are thought to encode touch in both coordinate systems concurrently, whereas congenitally blind individuals exhibit a strong bias for using anatomical coordinates. We investigated the neural correlates of this differential dominance in the use of anatomical and external reference frames by assessing oscillatory brain activity during a tactile spatial attention task. The EEG was recorded while sighted and congenitally blind adults received tactile stimulation to uncrossed and crossed hands while detecting rare tactile targets at one cued hand only. In the sighted group, oscillatory alpha-band activity (8-12Hz) in the cue-target interval was reduced contralaterally and enhanced ipsilaterally with uncrossed hands. Hand crossing attenuated the degree of posterior parietal alpha-band lateralization, indicating that attention deployment was affected by external spatial coordinates. Beamforming suggested that this posture effect originated in the posterior parietal cortex. In contrast, cue-related lateralization of central alpha-band as well as of beta-band activity (16-24Hz) were unaffected by hand crossing, suggesting that these oscillations exclusively encode anatomical coordinates. In the blind group, central alpha-band activity was lateralized, but did not change across postures. The pattern of beta-band activity was indistinguishable between groups. Because the neural mechanisms for posterior alpha-band generation seem to be linked to developmental vision, we speculate that the lack of this neural mechanism in blind individuals is related to their preferred use of anatomical over external spatial codes in sensory processing. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. The impact of the quality of life perception on the self-esteem of physically active adults

    Directory of Open Access Journals (Sweden)

    Daniel Vicentini de Oliveira

    2017-05-01

    Full Text Available This study aimed at investigating the impact of the quality of life perception on the self-esteem of physically active adults. A total of 63 male and female swimming practitioners (38.13 ± 11.72 were evaluated. A socio-demographic questionnaire, WHOQOL-Bref Scale, and the Rosenberg Self-Esteem Scale were used as tools. For data analysis the descriptive statistics, Kolmogorov-Smirnov Test, Mann-Whitney U Test, Spearman’s Rank Correlation Coefficient, and the Univariate Multiple Regression were used. No significant differences were found either for the quality of life or the self-esteem between sexes; there was a significant positive correlation (p < 0.05 among the physical (r = 0.37, psychological (r = 0.36 and environmental (r = 0.30 domains with self-esteem. The regression model explained 20% of the self-esteem variability, with moderate and significant pathways of the physical (β = 0.23 and psychological (β = 0.23 domains, whereas the environmental domain did not show a significant predictive relation (p = 0.988 with self-esteem. It is concluded that a higher quality of life perception may result in a higher self-esteem for physically active adults.

  20. Soil pH, total phosphorus, climate and distance are the major factors influencing microbial activity at a regional spatial scale

    DEFF Research Database (Denmark)

    Cao, Haichuan; Chen, Ruirui; Wang, Libing

    2016-01-01

    Considering the extensive functional redundancy in microbial communities and great difficulty in elucidating it based on taxonomic structure, studies on the biogeography of soil microbial activity at large spatial scale are as important as microbial community structure. Eighty-four soil samples...... scaling clearly revealed that soil microbial activities showed distinct differentiation at different sites over a regional spatial scale, which were strongly affected by soil pH, total P, rainfall, temperature, soil type and location. In addition, microbial community structure was greatly influenced...... scales. There are common (distance, climate, pH and soil type) but differentiated aspects (TP, SOC and N) in the biogeography of soil microbial community structure and activity....

  1. The perceptions of caregivers toward physical activity and health in youth with congenital heart disease.

    Science.gov (United States)

    Moola, Fiona; Fusco, Caroline; Kirsh, Joel A

    2011-02-01

    Medical advances have reduced mortality in youth with congenital heart disease (CHD). Although physical activity is associated with enhanced quality of life, most patients are inactive. By addressing medical and psychological barriers, previous literature has reproduced discourses of individualism which position cardiac youth as personally responsible for physical inactivity. Few sociological investigations have sought to address the influence of social barriers to physical activity, and the insights of caregivers are absent from the literature. In this study, caregiver perceptions toward physical activity for youth with CHD were investigated at a Canadian hospital. Media representations, school liability, and parental overprotection construct cardiac youth as "at risk" during physical activity, and position their health precariously. Indeed, from the perspective of hospital staff, the findings indicate the centrality of sociological factors to the physical activity experiences of youth with CHD, and the importance of attending to the contextual barriers that constrain their health and physical activity.

  2. Visualizing the Perception Filter and Breaching It with Active-Learning Strategies

    Science.gov (United States)

    White, Harold B.

    2012-01-01

    Teachers' perception filter operates in all realms of their consciousness. It plays an important part in what and how students learn and should play a central role in what and how they teach. This may be obvious, but having a visual model of a perception filter can guide the way they think about education. In this article, the author talks about…

  3. Spatial and temporal characteristics of V1 microstimulation during chronic implantation of a microelectrode array in a behaving macaque

    Science.gov (United States)

    Davis, T. S.; Parker, R. A.; House, P. A.; Bagley, E.; Wendelken, S.; Normann, R. A.; Greger, B.

    2012-12-01

    Objective. It has been hypothesized that a vision prosthesis capable of evoking useful visual percepts can be based upon electrically stimulating the primary visual cortex (V1) of a blind human subject via penetrating microelectrode arrays. As a continuation of earlier work, we examined several spatial and temporal characteristics of V1 microstimulation. Approach. An array of 100 penetrating microelectrodes was chronically implanted in V1 of a behaving macaque monkey. Microstimulation thresholds were measured using a two-alternative forced choice detection task. Relative locations of electrically-evoked percepts were measured using a memory saccade-to-target task. Main results. The principal finding was that two years after implantation we were able to evoke behavioural responses to electric stimulation across the spatial extent of the array using groups of contiguous electrodes. Consistent responses to stimulation were evoked at an average threshold current per electrode of 204 ± 49 µA (mean ± std) for groups of four electrodes and 91 ± 25 µA for groups of nine electrodes. Saccades to electrically-evoked percepts using groups of nine electrodes showed that the animal could discriminate spatially distinct percepts with groups having an average separation of 1.6 ± 0.3 mm (mean ± std) in cortex and 1.0° ± 0.2° in visual space. Significance. These results demonstrate chronic perceptual functionality and provide evidence for the feasibility of a cortically-based vision prosthesis for the blind using penetrating microelectrodes.

  4. The Solar System Ballet: A Kinesthetic Spatial Astronomy Activity

    Science.gov (United States)

    Heyer, Inge; Slater, T. F.; Slater, S. J.; Astronomy, Center; Education ResearchCAPER, Physics

    2011-05-01

    The Solar System Ballet was developed in order for students of all ages to learn about the planets, their motions, their distances, and their individual characteristics. To teach people about the structure of our Solar System can be revealing and rewarding, for students and teachers. Little ones (and some bigger ones, too) often cannot yet grasp theoretical and spatial ideas purely with their minds. Showing a video is better, but being able to learn with their bodies, essentially being what they learn about, will help them understand and remember difficult concepts much more easily. There are three segments to this activity, which can be done together or separately, depending on time limits and age of the students. Part one involves a short introductory discussion about what students know about the planets. Then students will act out the orbital motions of the planets (and also moons for the older ones) while holding a physical model. During the second phase we look at the structure of the Solar System as well as the relative distances of the planets from the Sun, first by sketching it on paper, then by recreating a scaled version in the class room. Again the students act out the parts of the Solar System bodies with their models. The third segment concentrates on recreating historical measurements of Earth-Moon-Sun system. The Solar System Ballet activity is suitable for grades K-12+ as well as general public informal learning activities.

  5. Hue-specific colour memory impairment in an individual with intact colour perception and colour naming.

    Science.gov (United States)

    Jakobson, L S; Pearson, P M; Robertson, B

    2008-01-15

    Cases of hue-selective dyschomatopsias, together with the results of recent optical imaging studies [Xiao, Y., Casti, A. R. R., Xiao, J., & Kaplan, E. (2006). A spatially organized representation of colour in macaque primary visual cortex. Perception, 35, ECVP Abstract Supplement; Xiao, Y., Wang, Y., & Felleman, D. J. (2003). A spatially organized representation of colour in macaque cortical area V2. Nature, 421, 535-539], have provided support for the idea that different colours are processed in spatially distinct regions of extrastriate cortex. In the present report, we provide evidence suggesting that a similar, but distinct, map may exist for representations of colour in memory. This evidence comes from observations of a young woman (QP) who demonstrates an isolated deficit in colour memory secondary to a concussive episode. Despite having normal colour perception and colour naming skills, and above-average memory skills in other domains, QP's ability to recall visually encoded colour information over short retention intervals is dramatically impaired. Her long-term memory for colour and her colour imagery skills are also abnormal. Surprisingly, however, these impairments are not seen with all hues; specifically, her ability to remember or imagine blue shades is spared. This interesting case contributes to the literature suggesting that colour perception, naming, and memory can be clinically dissociated, and provides insights into the organization of colour information in memory.

  6. Spatial Planning and Geo-ICT: How Spatial Planners Invented GIS and Are Still Learning How to Use It

    NARCIS (Netherlands)

    Wit, de A.; Brink, van den A.; Bregt, A.K.; Velde, van de R.

    2009-01-01

    Location is a fundamental aspect of spatial planning. It is subject to, and the result of, planning activities. It is therefore not surprising that the first incentives for the development of tools for spatial data management and spatial analysis came from professionals who were engaged in spatial

  7. Deconstruction of spatial integrity in visual stimulus detected by modulation of synchronized activity in cat visual cortex.

    Science.gov (United States)

    Zhou, Zhiyi; Bernard, Melanie R; Bonds, A B

    2008-04-02

    Spatiotemporal relationships among contour segments can influence synchronization of neural responses in the primary visual cortex. We performed a systematic study to dissociate the impact of spatial and temporal factors in the signaling of contour integration via synchrony. In addition, we characterized the temporal evolution of this process to clarify potential underlying mechanisms. With a 10 x 10 microelectrode array, we recorded the simultaneous activity of multiple cells in the cat primary visual cortex while stimulating with drifting sine-wave gratings. We preserved temporal integrity and systematically degraded spatial integrity of the sine-wave gratings by adding spatial noise. Neural synchronization was analyzed in the time and frequency domains by conducting cross-correlation and coherence analyses. The general association between neural spike trains depends strongly on spatial integrity, with coherence in the gamma band (35-70 Hz) showing greater sensitivity to the change of spatial structure than other frequency bands. Analysis of the temporal dynamics of synchronization in both time and frequency domains suggests that spike timing synchronization is triggered nearly instantaneously by coherent structure in the stimuli, whereas frequency-specific oscillatory components develop more slowly, presumably through network interactions. Our results suggest that, whereas temporal integrity is required for the generation of synchrony, spatial integrity is critical in triggering subsequent gamma band synchronization.

  8. Stress through the mind of the beholder: preliminary differences in child and maternal perceptions of child stress in relation to child cortisol and cardiovascular activity.

    Science.gov (United States)

    Allwood, Maureen A; Gaffey, Allison E; Vergara-Lopez, Chrystal; Stroud, Laura R

    2017-07-01

    The present study examined associations among parent and child reports of youth's stressful life events (SLEs), perceived stress, and biological measures of stress activity (i.e. cortisol and cardiovascular activity). Examining these aspects of youth stress presents several challenges. Unlike adult studies of individual differences in which information regarding SLEs, perceptions of events, and biological activity are gathered from one individual, assessment of individual differences among children usually involves other informants (e.g. parent). However, parent and child reports of SLEs and the child's psychological response to such events are often discordant. Moreover, examinations of youth perception of stress are hampered by limitations of child cognitive processes, as well as parents' limited knowledge of their child's perception of stress. In a preliminary effort to unscramble the complex effects of youth SLEs and perceived stress in relation to biological response to acute stressors, this study examined 51 boys and girls aged 7-16, with no history of psychopathology or medical concerns. Contrary to hypotheses, findings revealed that compared to actual experiences of stress, perceived stress has greater associations with both cortisol and cardiovascular activity. That is, perceived stress is more biologically salient relative to actual stress. Results also suggest that informant differences may explain some previous inconsistent findings in studies of youth's stress reactivity. The current findings mirror the adult studies that show appraisal and perception of traumatic and stressful events may be more predictive of negative health and mental health outcomes than the severity of the events. Further studies are needed to understand the impact of youth's perceptions of stress on their biological stress reactions and later health outcomes such as clinical disorders.

  9. Self-Motion Perception: Assessment by Real-Time Computer Generated Animations

    Science.gov (United States)

    Parker, Donald E.

    1999-01-01

    Our overall goal is to develop materials and procedures for assessing vestibular contributions to spatial cognition. The specific objective of the research described in this paper is to evaluate computer-generated animations as potential tools for studying self-orientation and self-motion perception. Specific questions addressed in this study included the following. First, does a non- verbal perceptual reporting procedure using real-time animations improve assessment of spatial orientation? Are reports reliable? Second, do reports confirm expectations based on stimuli to vestibular apparatus? Third, can reliable reports be obtained when self-motion description vocabulary training is omitted?

  10. Designing Customer Education Activities to Change People’s Perception of Catfish

    Directory of Open Access Journals (Sweden)

    Stevanus Pratama Suwito

    2017-06-01

    Full Text Available Most people see catfish as an unhygienic fish, so less people want to consume it. In fact, catfish has better nutrition compared to Gourami. Therefore, catfish producers need to educate people. The purpose of this research is to design customer education activities to change people’s perception towards catfish using marketing communication mix. This research is a qualitative research and it uses in-depth interview method in gathering the required data. Based on the preliminary survey conducted to 50 people in Surabaya, it is known that Surabaya people are considered novice customers. As such, catfish producers can conduct customer education activities until people want to taste the catfish. The company can add picture, video, and oral information about the benefits in consuming catfish or the nutrition and the certificate of hygienic cultivation system. The producers can provide tester for the catfish and show the customers the comparison between good and bad quality catfish. The producers can also add two more marketing communication activities i.e. events and experiences as well as public relations and publicity. The producers need to use reliable sources in informing the catfish’s nutrition facts such as the certificate of catfish breeder, and certification from BPOM.

  11. Shared memories reveal shared structure in neural activity across individuals

    Science.gov (United States)

    Chen, J.; Leong, Y.C.; Honey, C.J.; Yong, C.H.; Norman, K.A.; Hasson, U.

    2016-01-01

    Our lives revolve around sharing experiences and memories with others. When different people recount the same events, how similar are their underlying neural representations? Participants viewed a fifty-minute movie, then verbally described the events during functional MRI, producing unguided detailed descriptions lasting up to forty minutes. As each person spoke, event-specific spatial patterns were reinstated in default-network, medial-temporal, and high-level visual areas. Individual event patterns were both highly discriminable from one another and similar between people, suggesting consistent spatial organization. In many high-order areas, patterns were more similar between people recalling the same event than between recall and perception, indicating systematic reshaping of percept into memory. These results reveal the existence of a common spatial organization for memories in high-level cortical areas, where encoded information is largely abstracted beyond sensory constraints; and that neural patterns during perception are altered systematically across people into shared memory representations for real-life events. PMID:27918531

  12. Engaging narratives evoke similar neural activity and lead to similar time perception.

    Science.gov (United States)

    Cohen, Samantha S; Henin, Simon; Parra, Lucas C

    2017-07-04

    It is said that we lose track of time - that "time flies" - when we are engrossed in a story. How does engagement with the story cause this distorted perception of time, and what are its neural correlates? People commit both time and attentional resources to an engaging stimulus. For narrative videos, attentional engagement can be represented as the level of similarity between the electroencephalographic responses of different viewers. Here we show that this measure of neural engagement predicted the duration of time that viewers were willing to commit to narrative videos. Contrary to popular wisdom, engagement did not distort the average perception of time duration. Rather, more similar brain responses resulted in a more uniform perception of time across viewers. These findings suggest that by capturing the attention of an audience, narrative videos bring both neural processing and the subjective perception of time into synchrony.

  13. Physical activity and sedentary time: male perceptions in a university work environment.

    Science.gov (United States)

    George, Emma S; Kolt, Gregory S; Rosenkranz, Richard R; Guagliano, Justin M

    2014-03-01

    Promoting physical activity and reducing sedentary time in males can be challenging, and interventions tailored specifically for males are limited. Understanding male perceptions of physical activity and sedentary behavior is important to inform development of relevant interventions, especially for males working in an office setting. As part of a larger intervention study to increase physical activity and reduce sedentary time, male university employees aged 35 to 64 years were invited to partake in focus groups to discuss benefits, motivators, and barriers related to physical activity and sedentary time. Five semistructured focus group sessions, ranging from 50 to 70 minutes in duration, were conducted on two campuses at an Australian university. A total of 15 participants (9 academic/faculty staff and 6 professional staff), with a mean (± SD) age of 46.1 (±8.0) years took part in the study. Health and family were commonly discussed motivators for physical activity, whereas time constraints and work commitments were major barriers to physical activity participation. Sedentary time was a perceived "by-product" of participants' university employment, as a substantial proportion of their days were spent sitting, primarily at a computer. Participants believed that physical activity should be recognized as a legitimate activity at work, embedded within the university culture and endorsed using a top-down approach. It is important to encourage breaks in sedentary time and recognize physical activity as a legitimate health-promoting activity that is supported and encouraged during working hours. These findings can be used as a platform from which to develop targeted strategies to promote physical activity in male university employees.

  14. Tactile spatial working memory activates the dorsal extrastriate cortical pathway in congenitally blind individuals.

    Science.gov (United States)

    Bonino, D; Ricciardi, E; Sani, L; Gentili, C; Vanello, N; Guazzelli, M; Vecchi, T; Pietrini, P

    2008-09-01

    In sighted individuals, both the visual and tactile version of the same spatial working memory task elicited neural responses in the dorsal "where" cortical pathway (Ricciardi et al., 2006). Whether the neural response during the tactile working memory task is due to visually-based spatial imagery or rather reflects a more abstract, supramodal organization of the dorsal cortical pathway remains to be determined. To understand the role of visual experience on the functional organization of the dorsal cortical stream, using functional magnetic resonance imaging (fMRI) here we examined brain response in four individuals with congenital or early blindness and no visual recollection, while they performed the same tactile spatial working memory task, a one-back recognition of 2D and 3D matrices. The blind subjects showed a significant activation in bilateral posterior parietal cortex, dorsolateral and inferior prefrontal areas, precuneus, lateral occipital cortex, and cerebellum. Thus, dorsal occipito-parietal areas are involved in mental imagery dealing with spatial components in subjects without prior visual experience and in response to a non-visual task. These data indicate that recruitment of the dorsal cortical pathway in response to the tactile spatial working memory task is not mediated by visually-based imagery and that visual experience is not a prerequisite for the development of a more abstract functional organization of the dorsal stream. These findings, along with previous data indicating a similar supramodal functional organization within the ventral cortical pathway and the motion processing brain regions, may contribute to explain how individuals who are born deprived of sight are able to interact effectively with the surrounding world.

  15. Contribution of self-motion perception to acoustic target localization.

    Science.gov (United States)

    Pettorossi, V E; Brosch, M; Panichi, R; Botti, F; Grassi, S; Troiani, D

    2005-05-01

    The findings of this study suggest that acoustic spatial perception during head movement is achieved by the vestibular system, which is responsible for the correct dynamic of acoustic target pursuit. The ability to localize sounds in space during whole-body rotation relies on the auditory localization system, which recognizes the position of sound in a head-related frame, and on the sensory systems, namely the vestibular system, which perceive head and body movement. The aim of this study was to analyse the contribution of head motion cues to the spatial representation of acoustic targets in humans. Healthy subjects standing on a rotating platform in the dark were asked to pursue with a laser pointer an acoustic target which was horizontally rotated while the body was kept stationary or maintained stationary while the whole body was rotated. The contribution of head motion to the spatial acoustic representation could be inferred by comparing the gains and phases of the pursuit in the two experimental conditions when the frequency was varied. During acoustic target rotation there was a reduction in the gain and an increase in the phase lag, while during whole-body rotations the gain tended to increase and the phase remained constant. The different contributions of the vestibular and acoustic systems were confirmed by analysing the acoustic pursuit during asymmetric body rotation. In this particular condition, in which self-motion perception gradually diminished, an increasing delay in target pursuit was observed.

  16. Spatial and Temporal Variations in the Occurrence and Foraging Activity of Coastal Dolphins in Menai Bay, Zanzibar, Tanzania.

    Directory of Open Access Journals (Sweden)

    Andrew J Temple

    Full Text Available Understanding temporal patterns in distribution, occurrence and behaviour is vital for the effective conservation of cetaceans. This study used cetacean click detectors (C-PODs to investigate spatial and temporal variation in occurrence and foraging activity of the Indo-Pacific bottlenose (Tursiops aduncus and Indian Ocean humpback (Sousa plumbea dolphins resident in the Menai Bay Conservation Area (MBCA, Zanzibar, Tanzania. Occurrence was measured using detection positive minutes. Inter-click intervals were used to identify terminal buzz vocalisations, allowing for analysis of foraging activity. Data were analysed in relation to spatial (location and temporal (monsoon season, diel phase and tidal phase variables. Results showed significantly increased occurrence and foraging activity of dolphins in southern areas and during hours of darkness. Higher occurrence at night was not explained by diel variation in echolocation rate and so were considered representative of occurrence patterns. Both tidal phase and monsoon season influenced occurrence but results varied among sites, with no general patterns found. Foraging activity was greatest during hours of darkness, High water and Flood tidal phases. Comparisons of echolocation data among sites suggested differences in the broadband click spectra of MBCA dolphins, possibly indicative of species differences. These dolphin populations are threatened by unsustainable fisheries bycatch and tourism activities. The spatial and temporal patterns identified in this study have implications for future conservation and management actions with regards to these two threats. Further, the results indicate future potential for using passive acoustics to identify and monitor the occurrence of these two species in areas where they co-exist.

  17. Dissociable influences of auditory object vs. spatial attention on visual system oscillatory activity.

    Directory of Open Access Journals (Sweden)

    Jyrki Ahveninen

    Full Text Available Given that both auditory and visual systems have anatomically separate object identification ("what" and spatial ("where" pathways, it is of interest whether attention-driven cross-sensory modulations occur separately within these feature domains. Here, we investigated how auditory "what" vs. "where" attention tasks modulate activity in visual pathways using cortically constrained source estimates of magnetoencephalograpic (MEG oscillatory activity. In the absence of visual stimuli or tasks, subjects were presented with a sequence of auditory-stimulus pairs and instructed to selectively attend to phonetic ("what" vs. spatial ("where" aspects of these sounds, or to listen passively. To investigate sustained modulatory effects, oscillatory power was estimated from time periods between sound-pair presentations. In comparison to attention to sound locations, phonetic auditory attention was associated with stronger alpha (7-13 Hz power in several visual areas (primary visual cortex; lingual, fusiform, and inferior temporal gyri, lateral occipital cortex, as well as in higher-order visual/multisensory areas including lateral/medial parietal and retrosplenial cortices. Region-of-interest (ROI analyses of dynamic changes, from which the sustained effects had been removed, suggested further power increases during Attend Phoneme vs. Location centered at the alpha range 400-600 ms after the onset of second sound of each stimulus pair. These results suggest distinct modulations of visual system oscillatory activity during auditory attention to sound object identity ("what" vs. sound location ("where". The alpha modulations could be interpreted to reflect enhanced crossmodal inhibition of feature-specific visual pathways and adjacent audiovisual association areas during "what" vs. "where" auditory attention.

  18. Perception and psychological evaluation for visual and auditory environment based on the correlation mechanisms

    Science.gov (United States)

    Fujii, Kenji

    2002-06-01

    In this dissertation, the correlation mechanism in modeling the process in the visual perception is introduced. It has been well described that the correlation mechanism is effective for describing subjective attributes in auditory perception. The main result is that it is possible to apply the correlation mechanism to the process in temporal vision and spatial vision, as well as in audition. (1) The psychophysical experiment was performed on subjective flicker rates for complex waveforms. A remarkable result is that the phenomenon of missing fundamental is found in temporal vision as analogous to the auditory pitch perception. This implies the existence of correlation mechanism in visual system. (2) For spatial vision, the autocorrelation analysis provides useful measures for describing three primary perceptual properties of visual texture: contrast, coarseness, and regularity. Another experiment showed that the degree of regularity is a salient cue for texture preference judgment. (3) In addition, the autocorrelation function (ACF) and inter-aural cross-correlation function (IACF) were applied for analysis of the temporal and spatial properties of environmental noise. It was confirmed that the acoustical properties of aircraft noise and traffic noise are well described. These analyses provided useful parameters extracted from the ACF and IACF in assessing the subjective annoyance for noise. Thesis advisor: Yoichi Ando Copies of this thesis written in English can be obtained from Junko Atagi, 6813 Mosonou, Saijo-cho, Higashi-Hiroshima 739-0024, Japan. E-mail address: atagi\\@urban.ne.jp.

  19. Computational analysis of network activity and spatial reach of sharp wave-ripples.

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    Sadullah Canakci

    Full Text Available Network oscillations of different frequencies, durations and amplitudes are hypothesized to coordinate information processing and transfer across brain areas. Among these oscillations, hippocampal sharp wave-ripple complexes (SPW-Rs are one of the most prominent. SPW-Rs occurring in the hippocampus are suggested to play essential roles in memory consolidation as well as information transfer to the neocortex. To-date, most of the knowledge about SPW-Rs comes from experimental studies averaging responses from neuronal populations monitored by conventional microelectrodes. In this work, we investigate spatiotemporal characteristics of SPW-Rs and how microelectrode size and distance influence SPW-R recordings using a biophysical model of hippocampus. We also explore contributions from neuronal spikes and synaptic potentials to SPW-Rs based on two different types of network activity. Our study suggests that neuronal spikes from pyramidal cells contribute significantly to ripples while high amplitude sharp waves mainly arise from synaptic activity. Our simulations on spatial reach of SPW-Rs show that the amplitudes of sharp waves and ripples exhibit a steep decrease with distance from the network and this effect is more prominent for smaller area electrodes. Furthermore, the amplitude of the signal decreases strongly with increasing electrode surface area as a result of averaging. The relative decrease is more pronounced when the recording electrode is closer to the source of the activity. Through simulations of field potentials across a high-density microelectrode array, we demonstrate the importance of finding the ideal spatial resolution for capturing SPW-Rs with great sensitivity. Our work provides insights on contributions from spikes and synaptic potentials to SPW-Rs and describes the effect of measurement configuration on LFPs to guide experimental studies towards improved SPW-R recordings.

  20. Human activities on the deep seafloor in the North East Atlantic: an assessment of spatial extent.

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    Angela R Benn

    Full Text Available BACKGROUND: Environmental impacts of human activities on the deep seafloor are of increasing concern. While activities within waters shallower than 200 m have been the focus of previous assessments of anthropogenic impacts, no study has quantified the extent of individual activities or determined the relative severity of each type of impact in the deep sea. METHODOLOGY: The OSPAR maritime area of the North East Atlantic was chosen for the study because it is considered to be one of the most heavily impacted by human activities. In addition, it was assumed data would be accessible and comprehensive. Using the available data we map and estimate the spatial extent of five major human activities in the North East Atlantic that impact the deep seafloor: submarine communication cables, marine scientific research, oil and gas industry, bottom trawling and the historical dumping of radioactive waste, munitions and chemical weapons. It was not possible to map military activities. The extent of each activity has been quantified for a single year, 2005. PRINCIPAL FINDINGS: Human activities on the deep seafloor of the OSPAR area of the North Atlantic are significant but their footprints vary. Some activities have an immediate impact after which seafloor communities could re-establish, while others can continue to make an impact for many years and the impact could extend far beyond the physical disturbance. The spatial extent of waste disposal, telecommunication cables, the hydrocarbon industry and marine research activities is relatively small. The extent of bottom trawling is very significant and, even on the lowest possible estimates, is an order of magnitude greater than the total extent of all the other activities. CONCLUSIONS/SIGNIFICANCE: To meet future ecosystem-based management and governance objectives for the deep sea significant improvements are required in data collection and availability as well as a greater awareness of the relative impact of