scholarly journals Integrating somatosensory information over time

2019 ◽  
Author(s):  
Raúl Hernández-Pérez ◽  
Eduardo Rojas-Hortelano ◽  
Victor de Lafuente

AbstractOur choices are often informed by temporally integrating streams of sensory information. This has been well demonstrated in the visual and auditory domains, but the integration of tactile information over time has been less studied. We designed an active touch task in which subjects explored a spheroid-shaped object to determine its inclination with respect to the horizontal plane (inclined to the left or to the right). In agreement with previous findings, our results show that more errors, and longer decision times, accompany difficult decisions (small inclination angles). To gain insight into the decision-making process, we used a task in which the time available for tactile exploration was varied by the experimenter, in a trial-by-trial basis. The behavioral results were fit with a model of bounded accumulation, and also with an independent-sampling model which assumes no sensory accumulation. The results of model fits favor an accumulation-to-bound mechanism, and suggest that participants integrate the first 600 ms of 1800 ms-long stimuli. This means that the somatosensory system benefits from longer streams of information although it does not make use of all available evidence.HighlightsThe somatosensory system integrates information streams through time.Somatosensory discrimination thresholds decrease with longer stimuli.A bounded accumulation model is favored over independent sampling.Humans accumulate up to 600 ms, out of 1800 ms-long stimuli.

2019 ◽  
Author(s):  
Sonia Ponzo ◽  
Louise P. Kirsch ◽  
Aikaterini Fotopoulou ◽  
Paul M. Jenkinson

AbstractBackgroundThe vestibular system has been shown to contribute to multisensory integration by balancing conflictual sensory information. It remains unclear whether such modulation of exteroceptive (e.g. vision), proprioceptive and interoceptive (e.g. affective touch) sensory sources is influenced by epistemically different aspects of tactile stimulation (i.e. felt from within vs seen, vicarious touch).ObjectiveWe aimed to i) replicate previous findings regarding the effects of galvanic stimulation of the right vestibular network (i.e. LGVS) in multisensory integration and ii) examine vestibular contributions to multisensory integration when touch is felt but not seen (and vice-versa).MethodDuring artificial vestibular stimulation (LGVS, RGVS and Sham), healthy participants (N=36, Experiment 1; N=37, Experiment 2) looked at a rubber hand while either their own unseen hand or the rubber hand were touched by affective or neutral touch.ResultsWe found that i) LGVS led to enhancement of vision over proprioception during visual only conditions (replicating our previous findings), and ii) LGVS (vs Sham) favoured proprioception over vision when touch was felt (Experiment 1), with the opposite results when touch was vicariously perceived via vision (Experiment 2), and with no difference between affective and neutral touch.ConclusionsWe showed how vestibular signals modulate the weight of each sensory modality according to the context in which they are perceived and that such modulation extends to different aspects of tactile stimulation: felt and seen touch are differentially balanced in multisensory integration according to their epistemic relevance.HighlightsLGVS increased proprioceptive drift during vision of a rubber handTouch on participant’s hand decreased proprioceptive drift during LGVSVicarious touch on the Rubber Hand increased proprioceptive drift during LGVSVestibular signals differently balance sensory sources in multisensory integration


2020 ◽  
pp. 1-9
Author(s):  
Daniel Bergé ◽  
Tyler A. Lesh ◽  
Jason Smucny ◽  
Cameron S. Carter

Abstract Background Previous research in resting-state functional magnetic resonance imaging (rs-fMRI) has shown a mixed pattern of disrupted thalamocortical connectivity in psychosis. The clinical meaning of these findings and their stability over time remains unclear. We aimed to study thalamocortical connectivity longitudinally over a 1-year period in participants with recent-onset psychosis. Methods To this purpose, 129 individuals with recent-onset psychosis and 87 controls were clinically evaluated and scanned using rs-fMRI. Among them, 43 patients and 40 controls were re-scanned and re-evaluated 12 months later. Functional connectivity between the thalamus and the rest of the brain was calculated using a seed to voxel approach, and then compared between groups and correlated with clinical features cross-sectionally and longitudinally. Results At baseline, participants with recent-onset psychosis showed increased connectivity (compared to controls) between the thalamus and somatosensory and temporal regions (k = 653, T = 5.712), as well as decreased connectivity between the thalamus and left cerebellum and right prefrontal cortex (PFC; k = 201, T = −4.700). Longitudinal analyses revealed increased connectivity over time in recent-onset psychosis (relative to controls) in the right middle frontal gyrus. Conclusions Our results support the concept of abnormal thalamic connectivity as a core feature in psychosis. In agreement with a non-degenerative model of illness in which functional changes occur early in development and do not deteriorate over time, no evidence of progressive deterioration of connectivity during early psychosis was observed. Indeed, regionally increased connectivity between thalamus and PFC was observed.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2573
Author(s):  
Yi-Hsiu Chung ◽  
Cheng-Kun Tsai ◽  
Ching-Fang Yu ◽  
Wan-Ling Wang ◽  
Chung-Lin Yang ◽  
...  

Purpose: By taking advantage of 18F-FDG PET imaging and tissue nuclear magnetic resonance (NMR) metabolomics, we examined the dynamic metabolic alterations induced by liver irradiation in a mouse model for hepatocellular carcinoma (HCC). Methods: After orthotopic implantation with the mouse liver cancer BNL cells in the right hepatic lobe, animals were divided into two experimental groups. The first received irradiation (RT) at 15 Gy, while the second (no-RT) did not. Intergroup comparisons over time were performed, in terms of 18F-FDG PET findings, NMR metabolomics results, and the expression of genes involved in inflammation and glucose metabolism. Results: As of day one post-irradiation, mice in the RT group showed an increased 18F-FDG uptake in the right liver parenchyma compared with the no-RT group. However, the difference reached statistical significance only on the third post-irradiation day. NMR metabolomics revealed that glucose concentrations peaked on day one post-irradiation both, in the right and left lobes—the latter reflecting a bystander effect. Increased pyruvate and glutamate levels were also evident in the right liver on the third post-irradiation day. The expression levels of the glucose-6-phosphatase (G6PC) and fructose-1, 6-bisphosphatase 1 (FBP1) genes were down-regulated on the first and third post-irradiation days, respectively. Therefore, liver irradiation was associated with a metabolic shift from an impaired gluconeogenesis to an enhanced glycolysis from the first to the third post-irradiation day. Conclusion: Radiation-induced metabolic alterations in the liver parenchyma occur as early as the first post-irradiation day and show dynamic changes over time.


2019 ◽  
Vol 24 ◽  
Author(s):  
R. Egan ◽  
S. Cartagena ◽  
R. Mohamed ◽  
V. Gosrani ◽  
J. Grewal ◽  
...  

AbstractCyber Operational Risk: Cyber risk is routinely cited as one of the most important sources of operational risks facing organisations today, in various publications and surveys. Further, in recent years, cyber risk has entered the public conscience through highly publicised events involving affected UK organisations such as TalkTalk, Morrisons and the NHS. Regulators and legislators are increasing their focus on this topic, with General Data Protection Regulation (“GDPR”) a notable example of this. Risk actuaries and other risk management professionals at insurance companies therefore need to have a robust assessment of the potential losses stemming from cyber risk that their organisations may face. They should be able to do this as part of an overall risk management framework and be able to demonstrate this to stakeholders such as regulators and shareholders. Given that cyber risks are still very much new territory for insurers and there is no commonly accepted practice, this paper describes a proposed framework in which to perform such an assessment. As part of this, we leverage two existing frameworks – the Chief Risk Officer (“CRO”) Forum cyber incident taxonomy, and the National Institute of Standards and Technology (“NIST”) framework – to describe the taxonomy of a cyber incident, and the relevant cyber security and risk mitigation items for the incident in question, respectively.Summary of Results: Three detailed scenarios have been investigated by the working party:∙Employee leaks data at a general (non-life) insurer: Internal attack through social engineering, causing large compensation costs and regulatory fines, driving a 1 in 200 loss of £210.5m (c. 2% of annual revenue).∙Cyber extortion at a life insurer: External attack through social engineering, causing large business interruption and reputational damage, driving a 1 in 200 loss of £179.5m (c. 6% of annual revenue).∙Motor insurer telematics device hack: External attack through software vulnerabilities, causing large remediation / device replacement costs, driving a 1 in 200 loss of £70.0m (c. 18% of annual revenue).Limitations: The following sets out key limitations of the work set out in this paper:∙While the presented scenarios are deemed material at this point in time, the threat landscape moves fast and could render specific narratives and calibrations obsolete within a short-time frame.∙There is a lack of historical data to base certain scenarios on and therefore a high level of subjectivity is used to calibrate them.∙No attempt has been made to make an allowance for seasonality of renewals (a cyber event coinciding with peak renewal season could exacerbate cost impacts)∙No consideration has been given to the impact of the event on the share price of the company.∙Correlation with other risk types has not been explicitly considered.Conclusions: Cyber risk is a very real threat and should not be ignored or treated lightly in operational risk frameworks, as it has the potential to threaten the ongoing viability of an organisation. Risk managers and capital actuaries should be aware of the various sources of cyber risk and the potential impacts to ensure that the business is sufficiently prepared for such an event. When it comes to quantifying the impact of cyber risk on the operations of an insurer there are significant challenges. Not least that the threat landscape is ever changing and there is a lack of historical experience to base assumptions off. Given this uncertainty, this paper sets out a framework upon which readers can bring consistency to the way scenarios are developed over time. It provides a common taxonomy to ensure that key aspects of cyber risk are considered and sets out examples of how to implement the framework. It is critical that insurers endeavour to understand cyber risk better and look to refine assumptions over time as new information is received. In addition to ensuring that sufficient capital is being held for key operational risks, the investment in understanding cyber risk now will help to educate senior management and could have benefits through influencing internal cyber security capabilities.


1992 ◽  
Vol 68 (2) ◽  
pp. 518-527 ◽  
Author(s):  
T. P. Pons ◽  
P. E. Garraghty ◽  
M. Mishkin

1. Selective ablations of the hand representations in postcentral cortical areas 3a, 3b, 1, and 2 were made in different combinations to determine each area's contribution to the responsivity and modality properties of neurons in the hand representation in SII. 2. Ablations that left intact only the postcentral areas that process predominantly cutaneous inputs (i.e., areas 3b and 1) yielded SII recording sites responsive to cutaneous stimulation and none driven exclusively by high-intensity or "deep" stimulation. Conversely, ablations that left intact only the postcentral areas that process predominantly deep receptor inputs (i.e., areas 3a and 2) yielded mostly SII recording sites that responded exclusively to deep stimulation. 3. Ablations that left intact only area 3a or only area 2 yielded substantial and roughly equal reductions in the number of deep receptive fields in SII. By contrast, ablations that left intact only area 3b or only area 1 yielded unequal reductions in the number of cutaneous receptive fields in SII: a small reduction when area 3b alone was intact but a somewhat larger one when only area 1 was intact. 4. Finally, when the hand representation in area 3b was ablated, leaving areas 3a, 1, and 2 fully intact, there was again a substantial reduction in the encounter rate of cutaneous receptive fields. 5. The partial ablations often led to unresponsive sites in the SII hand representation. In SII representations other than of the hand no such unresponsive sites were found and there were no substantial changes in the ratio of cutaneous to deep receptive fields, indicating that the foregoing results were not due to long-lasting postsurgical depression or effects of anesthesia. 6. The findings indicate that modality-specific information is relayed from postcentral cortical areas to SII along parallel channels, with cutaneous inputs transmitted via areas 3b and 1, and deep inputs via areas 3a and 2. Further, area 3b provides the major source of cutaneous input to SII, directly and perhaps also via area 1. 7. The results are in line with accumulating anatomic and electrophysiologic evidence pointing to an evolutionary shift in the organization of the somatosensory system from the general mammalian plan, in which tactile information is processed in parallel in SI and SII, to a new organization in higher primates in which the processing of tactile information proceeds serially from SI to SII. The presumed functional advantages of this evolutionary shift are unknown.


1990 ◽  
Vol 80 ◽  
pp. 74-96 ◽  
Author(s):  
Elizabeth A. Meyer

It is now notorious that the production of inscriptions in the Roman Empire was not constant over time, but rose over the first and second centuries A.D. and fell in the third. Ramsay MacMullen pointed this out more than five years ago, with conclusions more cautionary than explanatory: ‘history is not being written in the right way’, he said, for historians have deduced Rome's decline from evidence that–since it appears only epigraphically–has merely disappeared for its own reasons, or have sought general explanations of decline in theories political, economic, or even demographic in nature, none of which can, in turn, explain the disappearance of epigraphy itself. Why this epigraphic habit rose and fell MacMullen left open to question, although he did postulate control by a ‘sense of audience’. The purpose of this paper is to propose that this ‘sense of audience’ was not generalized or generic, but depended on a belief in the value of romanization, of which (as noted but not explained by MacMullen's article) the epigraphic habit is also a rough indicator. Epitaphs constitute the bulk of all provincial inscriptions and in form and number are (generally speaking) the consequence of a provincial imitation of characteristically Roman practices, an imitation that depended on the belief that Roman legal status and style were important, and that may indeed have ultimately depended, at least in North Africa, on the acquisition or prior possession of that status. Such status-based motivations for erecting an epitaph help to explain not only the chronological distribution of epitaphs but also the differences in the type and distribution of epitaphs in the western and eastern halves of the empire. They will be used here moreover to suggest an explanation for the epigraphic habit as a whole.


2015 ◽  
Vol 86 (1) ◽  
pp. 94-100 ◽  
Author(s):  
Christos Livas ◽  
Nikolaos Pandis ◽  
Johan Willem Booij ◽  
Demetrios J. Halazonetis ◽  
Christos Katsaros ◽  
...  

ABSTRACT Objective:  To assess the maxillary second molar (M2) and third molar (M3) inclination following orthodontic treatment of Class II subdivision malocclusion with unilateral maxillary first molar (M1) extraction. Materials and Methods:  Panoramic radiographs of 21 Class II subdivision adolescents (eight boys, 13 girls; mean age, 12.8 years; standard deviation, 1.7 years) before treatment, after treatment with extraction of one maxillary first molar and Begg appliances and after at least 1.8 years in retention were retrospectively collected from a private practice. M2 and M3 inclination angles (M2/ITP, M2/IOP, M3/ITP, M3/IOP), constructed by intertuberosity (ITP) and interorbital planes (IOP), were calculated for the extracted and nonextracted segments. Random effects regression analysis was performed to evaluate the effect on the molar angulation of extraction, time, and gender after adjusting for baseline measurements. Results:  Time and extraction status were significant predictors for M2 angulation. M2/ITP and M2/IOP decreased by 4.04 (95% confidence interval [CI]: −6.93, 1.16; P  =  .001) and 3.67 (95% CI: −6.76, −0.58; P  =  .020) in the extraction group compared to the nonextraction group after adjusting for time and gender. The adjusted analysis showed that extraction was the only predictor for M3 angulation that reached statistical significance. M3 mesial inclination increased by 7.38° (95% CI: −11.2, −3.54; P < .001) and 7.33° (95% CI: −11.48, −3.19; P  =  .001). Conclusions:  M2 and M3 uprighting significantly improved in the extraction side after orthodontic treatment with unilateral maxillary M1 extraction. There was a significant increase in mesial tipping of maxillary second molar crowns over time.


2019 ◽  
Vol 15 (S367) ◽  
pp. 402-403
Author(s):  
Natalia Guevara ◽  
Rodrigo F. Haack ◽  
Victoria B. Acosta ◽  
María A. Senn ◽  
Carolina A. Silva ◽  
...  

AbstractThe “Right to the night sky” outreach project holds astronomy workshops for children and teens deprived of their liberty in juvenile detention centers. It is carried out by an interdisciplinary group of students, graduates, and teachers of Astronomy, Geophysics, Educational Science, Law, Psychology, Social Work, and Social Communication. It’s has been accredited and recognized by the Faculty of Astronomical and Geophysical Sciences, and the National University of La Plata (Argentina) since the year 2014. This work presents the diverse activities developed in the project, the methodologies used, and an analysis of how the project evolved, grew, and expanded over time, continuing what has already been presented by Charalambous et al. (2014) and Haack et al. (2019)


Author(s):  
Zhichao Geng ◽  
Ping Zhou ◽  
Lei Meng ◽  
Ying Yan ◽  
Dongming Guo

Abstract Lapping has a history of hundreds of years, yet it still relies on the experience of workers. To improve the automaticity and controllability of the lapping process, a modeling method of friction and wear is developed to predict the surface profile evolution of the workpiece and lapping plate in the lapping process. In the proposed method, by solving the balance equations of resultant force and moment, the inclination angles of the workpiece can be calculated, thus more accurate contact pressure distribution of the workpiece/lapping plate interface can be calculated. Combined with the material removal rate model, the continuous evolution process of the workpiece and lapping plate can be predicted in the lapping process. The modeling method was validated by a lapping test of a flat optical glass (Φ 100 mm) with a composite copper plate. The results show that the proposed method can predict the evolution of the surface profile of the workpiece and lapping plate with high accuracy. Consequently, the lapping plate can be dressed at the right time point. Benefit from this, in the validation test the PV value of the workpiece (with 5 mm edge exclusion) was reduced from 5.279 μm to 0.267 μm in 30 min. The proposed surface profile evolution modeling method not only improves the lapping efficiency but also provides an opportunity to understand the lapping process.


2021 ◽  
pp. tobaccocontrol-2021-056628
Author(s):  
Mônica Nunes-Rubinstein ◽  
Teresa Leão

ObjectivesTo identify proponents and opponents of the commercialisation and marketing of e-cigarettes and heated tobacco products (HTPs), identify the arguments used on both sides and compare how the arguments have changed over time, we analysed three policy discussions occurring in 2009, 2018 and 2019.MethodsWe conducted a content analysis of one document and six videos from these discussions, provided on the Brazilian Health Regulatory Agency website, or upon request.ResultsThe arguments most used by tobacco companies were related to claims that the use of e-cigarettes and HTPs is less harmful than conventional tobacco. Unions that support its commercialisation also argued that lifting the ban would prevent smuggling and guarantee their quality. On the other side, universities, medical and anti-tobacco institutions argued that such devices may have health risks, including the risk of inducing cigarette smoking. In 2009, most arguments belonged to the ‘health’ theme, while in 2018 and 2019 economic arguments and those related to morals and ethics were frequently used.ConclusionsThose that supported the commercialisation and marketing of e-cigarettes and HTPs first focused on arguments of harm reduction, while 10 years later the right to access and potential economic consequences also became common. Public health agents and academics must gather evidence to effectively respond to these arguments and discuss these policies, and must prepare themselves to use and respond to arguments related to moral and economic themes.


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