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- Abbott, Max, et al.
(författare)
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Conceptual Framework of Harmful Gambling: An International Collaboration
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- While seen by many as a form of leisure and recreation, gambling can have serious repercussions for individuals, families, and society as a whole. The harmful effects of gambling have been studied for decades to attempt to understand individual differences in gambling engagement and the life- course of gamblingrelated problems. In this publication, we present a comprehensive, internationally relevant conceptual framework of “harmful gambling” that moves beyond a symptoms-based view of harm and addresses a broad set of factors related to population risk, community and societal effects. Interactive factors represented in the framework represent major themes in gambling that range from specific (gambling environment, exposure, types, and resources) to general (cultural, social, psychological, and biological). This framework has been created by international and interdisciplinary experts from a variety of stakeholder perspectives - including researchers, treatment providers, operators, policy makers, and individuals and their families - to facilitate an understanding of harmful gambling. It not only reflects the state of knowledge as it relates to factors influencing harmful gambling, but also acts to guide the development of future research programs and educate policy makers on issues related to harmful gambling. The Ontario Problem Gambling Research Centre (Guelph, Ontario, Canada) has facilitated the development of the Conceptual Framework of Harmful Gambling and is committed to updating it over time.
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| 2. |
- Smith, Michael, et al.
(författare)
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Physiological reaction thresholds to vibration during sleep : Vibrationsnivåer som framkallar fysiologisk reaktion under sömn
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The World Health Organization Night Noise Guidelines for Europe 2009 report that there is sufficient evidence for biological effects of noise on sleep, starting at LAF,max,inside=32 dB [1]. Alterations in sleep structure and electroencephalogram (EEG) awakenings start to occur at LAF,max,inside=35 dB. Changes in cardiovascular activity during sleep also occur as a result of noise exposure, but threshold levels have not been determined. Noise from freight trains in particular has been found to cause more frequent awakenings [2] and stronger cardiac response [3] than passenger trains. In the field, freight trains are often accompanied by low frequency vibration, with amplitudes commonly around 0.4 – 1.5 mm/s (comfort weighted [4]) near railway lines [5]. As with noise, moderate to high level vibration from freight has been shown to contribute towards cortical EEG reactions and changes of heart rate during sleep [6-8]. However, it is not presently known at what threshold levels physiological effects due to vibration begin to occur. The research group aimed to identify a physiological reaction threshold to vibration during sleep. An initial pilot study was conducted to give a first indication of where such a threshold might lie. A subsequent larger-scale main study further investigated the vibration level response threshold, and also provided knowledge regarding what physiological response occur at 0.4 mm/s, the current lowest limit value enforced for new railway lines in Sweden [9]. Changes in sleep stage and awakenings were observed at 0.4 mm/s, while indications were seen at 0.3 mm/s but not 0.2 mm/s (see Figure 1). Changes in heart rate were seen at 0.3 and 0.4 mm/s, but not at 0.2 mm/s (see Figure 2). This study found that the physiological effects and threshold levels for these WHO defined effects were 0.3 mm/s for changes in cardiac activity, and 0.4 mm/s for EEG awakenings and changes in sleep structure and fragmentation of sleep (see Table 2).
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| 3. |
- Lindeberg, Tony, 1964-, et al.
(författare)
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Foveal scale-space and the linear increase of receptive field size as a function of eccentricity
- 1994
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper addresses the formulation of a foveal scale-space and its relation to the scaling property of receptive field sizes with eccentricity. It is shown how the notion of a fovea can be incorporated into conventional scale-space theory leading to a foveal log-polar scale-space. Natural assumptions about uniform treatment of structures over scales and finite processing capacity imply a linear increase of minimum receptive field size as a function of eccentricity. These assumptions are similar to the ones used for deriving linear scale-space theory and the Gaussian receptive field model for an idealized visual front-end.
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| 4. |
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| 5. |
- Lindeberg, Tony, Professor, 1964-
(författare)
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Covariance properties under natural image transformations for the generalized Gaussian derivative model for visual receptive fields
- 2023
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Ingår i: Frontiers in Computational Neuroscience. - : Frontiers Media SA. - 1662-5188. ; 17, s. 1189949-1-1189949-23
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The property of covariance, also referred to as equivariance, means that an image operator is well-behaved under image transformations, in the sense that the result of applying the image operator to a transformed input image gives essentially a similar result as applying the same image transformation to the output of applying the image operator to the original image. This paper presents a theory of geometric covariance properties in vision, developed for a generalized Gaussian derivative model of receptive fields in the primary visual cortex and the lateral geniculate nucleus, which, in turn, enable geometric invariance properties at higher levels in the visual hierarchy.It is shown how the studied generalized Gaussian derivative model for visual receptive fields obeys true covariance properties under spatial scaling transformations, spatial affine transformations, Galilean transformations and temporal scaling transformations. These covariance properties imply that a vision system, based on image and video measurements in terms of the receptive fields according to the generalized Gaussian derivative model, can, to first order of approximation, handle the image and video deformations between multiple views of objects delimited by smooth surfaces, as well as between multiple views of spatio-temporal events, under varying relative motions between the objects and events in the world and the observer.We conclude by describing implications of the presented theory for biological vision, regarding connections between the variabilities of the shapes of biological visual receptive fields and the variabilities of spatial and spatio-temporal image structures under natural image transformations. Specifically, we formulate experimentally testable biological hypotheses as well as needs for measuring population statistics of receptive field characteristics, originating from predictions from the presented theory, concerning the extent to which the shapes of the biological receptive fields in the primary visual cortex span the variabilities of spatial and spatio-temporal image structures induced by natural image transformations, based on geometric covariance properties.
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| 6. |
- Lindeberg, Tony, 1964-
(författare)
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Normative theory of visual receptive fields
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This article gives an overview of a normative computational theory of visual receptive fields, by which idealized shapes of early spatial, spatio-chromatic and spatio-temporal receptive fields can be derived in an axiomatic way based on structural properties of the environment in combination with assumptions about the internal structure of a vision system to guarantee consistent handling of image representations over multiple spatial and temporal scales. Interestingly, this theory leads to predictions about visual receptive field shapes with qualitatively very good similarity to biological receptive fields measured in the retina, the LGN and the primary visual cortex (V1) of mammals.
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| 8. |
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| 9. |
- Thaung, Jörgen, 1965, et al.
(författare)
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Retinal injuries from handheld lasers: An updated report.
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Background Handheld lasers, or powerful laser pointers, continue to cause eye injuries around the world. In 2013 the Swedish Radiation Safety Authority (SSM) published a report on eye injuries from handheld lasers (Löfgren et al. 2013). Objectives The purpose of this study was to update the previous report by examining the medical case histories of retinal injuries during the recent 2-3 years. The main focus was misuse of continuous wave handheld lasers leading to eye injuries. Inclusion criteria were primarily laser exposures using visible and near-infrared radiation (400-1400 nm) and short durations (0.05-1 s). Comparisons of the newly described laser exposures with exposure limits and eye injuries need to be re-examined. Also a timeline overview of the identifiable organic damages needed to be developed. Results A total of 47 new cases were found in the scientific literature. Unfortunately, many of them were described with insufficient data regarding the laser exposure. Analysis of estimated laser exposure were performed in eight cases and compared to international laser exposure limits. In four of the eight cases the exposures were estimated to be more than 100 times higher than the limits, and in one case the exposure was estimated to be 300+ times the safety limit. We found an increase in the number of reported cases with severe retinal injury. Need for further research We have previously identified topics for future research. For example, a national database of laser incidents, studies of photochemical effects, how visual aids can influence retinal exposure, treatments of laser retinal damages, secondary injuries (e.g. by glare), and long term or permanent functional deficits. In this report we have, in addition to the above topics, proposed a study to investigate the increased risk of retinal damage in cases when green handheld laser pointers are leaking infrared radiation.
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| 10. |
- Sjölie, Daniel, 1977-, et al.
(författare)
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Capturing neural correlates of disrupted presence ina naturalistic virtual environment
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The concept of presence is commonly related to whether or not a user feels, acts, and reacts as if he/she were in a real familiar environment when using a virtual reality (VR) application. Understanding the neural correlates of presence may provide a foundation for objective measurements of presence and important constraints for theoretical explanations of presence. Discussions about the neural basis for presence are relatively common, but brain imaging has rarely been applied to investigating this issue. Previous studies have focused on detecting average differences between conditions that correlate with differences in reported presence. In this study we focused on breaks in presence and associated periods of disrupted presence as an important complement to previous work. Specifically, we measured brain activity with functional magnetic resonance imaging (fMRI) during execution of an everyday task in a naturalistic virtual environment (VE). Time periods of disrupted presence were identified by subject reports indicating something strange in the current environment, interpreted as a violation of expectations related to the sense of presence. Disrupted presence was associated with increased activity in the frontopolar cortex (FPC), lateral occipito-temporal cortex (LOTC), the temporal poles (TP), and the posterior superior temporal cortex (pSTC). We relate these areas to integration of key aspects of a presence experience, relating the (changing) situation to management of task and goals (FPC), interpretation of visual input (LOTC), emotional evaluation of the context (TP) and possible interactions (pSTC). Modulation of the activity level in these brain areas is consistent with an interpretation of disrupted presence as a re-evaluation of key aspects of a subjective mental reality, updating the synchronization with the virtual environment as previous predictions fail. Such a subjective mental reality may also be related to a self-centered type of mentalization, providing a link to accounts of presence building on the self.
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