2,148 research outputs found
Recommended from our members
The multisensory attentional consequences of tool use : a functional magnetic resonance imaging study
Background: Tool use in humans requires that multisensory information is integrated across different locations, from objects
seen to be distant from the hand, but felt indirectly at the hand via the tool. We tested the hypothesis that using a simple tool
to perceive vibrotactile stimuli results in the enhanced processing of visual stimuli presented at the distal, functional part of the
tool. Such a finding would be consistent with a shift of spatial attention to the location where the tool is used.
Methodology/Principal Findings: We tested this hypothesis by scanning healthy human participantsâ brains using
functional magnetic resonance imaging, while they used a simple tool to discriminate between target vibrations,
accompanied by congruent or incongruent visual distractors, on the same or opposite side to the tool. The attentional
hypothesis was supported: BOLD response in occipital cortex, particularly in the right hemisphere lingual gyrus, varied
significantly as a function of tool position, increasing contralaterally, and decreasing ipsilaterally to the tool. Furthermore,
these modulations occurred despite the fact that participants were repeatedly instructed to ignore the visual stimuli, to
respond only to the vibrotactile stimuli, and to maintain visual fixation centrally. In addition, the magnitude of multisensory
(visual-vibrotactile) interactions in participantsâ behavioural responses significantly predicted the BOLD response in occipital
cortical areas that were also modulated as a function of both visual stimulus position and tool position.
Conclusions/Significance: These results show that using a simple tool to locate and to perceive vibrotactile stimuli is
accompanied by a shift of spatial attention to the location where the functional part of the tool is used, resulting in
enhanced processing of visual stimuli at that location, and decreased processing at other locations. This was most clearly
observed in the right hemisphere lingual gyrus. Such modulations of visual processing may reflect the functional
importance of visuospatial information during human tool use
Evaluating the impact of the Alcohol Act on off-trade alcohol sales: a natural experiment in Scotland
<b>Background and aims</b>
A ban on multi-buy discounts of off-trade alcohol was introduced as part of the Alcohol Act in Scotland in October 2011. The aim of this study was to assess the impact of this legislation on alcohol sales, which provide the best indicator of population consumption.<p></p>
<b>Design Setting and Participants</b>
Interrupted time-series regression was used to assess the impact of the Alcohol Act on alcohol sales among off-trade retailers in Scotland. Models accounted for underlying seasonal and secular trends and were adjusted for disposable income, alcohol prices and substitution effects. Data for off-trade retailers in England and Wales combined (EW) provided a control group.<p></p>
<b>Measurements</b>
Weekly data on the volume of pure alcohol sold by off-trade retailers in Scotland and EW between January 2009 and September 2012.<p></p>
<b>Findings</b>
The introduction of the legislation was associated with a 2.6% (95% CI -5.3 to 0.2%, P = 0.07) decrease in off-trade alcohol sales in Scotland, but not in EW (-0.5%, -4.6 to 3.9%, P = 0.83). A statistically significant reduction was observed in Scotland when EW sales were adjusted for in the analysis (-1.7%, -3.1 to -0.3%, P = 0.02). The decline in Scotland was driven by reduced off-trade sales of wine (-4.0%, -5.4 to -2.6%, P < 0.001) and pre-mixed beverages (-8.5%, -12.7 to -4.1%, P < 0.001). There were no associated changes in other drink types in Scotland, or in sales of any drink type in EW.<p></p>
<b>Conclusions</b>
The introduction of the Alcohol Act in Scotland in 2011 was associated with a decrease in total off-trade alcohol sales in Scotland, largely driven by reduced off-trade wine sales
Delhi Flag Handover Ceremony 2010 volunteer project
The Delhi Flag Handover Ceremony (DFHC) was a project delivered by Glasgow Life on behalf of the Glasgow 2014 Organising Committee. The Handover Ceremony took place towards the end of the 2010 Commonwealth Games in Delhi and reflects the passing of responsibility for the Games from one host to the next (i.e. Glasgow). This report reflects on Glasgowâs approach to the DFHC, specifically its recruitment of a Mass Cast of 348 volunteers to participate in an 8-minute performance in Delhi. Glasgow sought to secure participation from across Scotland drawing on both semi-professional and amateur performers
An evaluation of the domestic pre-event social representations of the Glasgow 2014 Commonwealth Games
An evaluation of the domestic pre-event social representations of the Glasgow 2014 Commonwealth Game
The image impact of second-order mega-events: a case study of the 2014 Commonwealth Games
The overall aim of this research, located within the critical realist research paradigm, and underpinned by social representation theory, is to evaluate the domestic image impact of hosting the 2014 CG for the city of Glasgow, and
in doing so, determine the extent to which hosting this event represents an appropriate strategy to improve the cityâs domestic image
Lateral parietal contributions to memory impairment in posterior cortical atrophy
Objective: Posterior cortical atrophy (PCA) is a neurodegenerative syndrome characterised by progressive impairment in visuospatial and perceptual function. Recent findings show that memory functioning can also be compromised early in the course of disease. In this study, we investigated the neural basis of memory impairment in PCA, and hypothesised that correlations would be observed with parietal cortex rather than classic medial temporal memory structures. Methods: Eighteen PCA patients, 15 typical Alzheimer's disease (tAD) patients and 21 healthy controls underwent memory testing with the Rey Auditory Verbal Learning Test (RAVLT) word list and MRI. Voxel-based morphometry (VBM) was used to identify regions in the parietal and medial temporal lobes that correlated with memory performance. Results: Compared with controls, PCA patients were impaired at learning, immediate and delayed recall and recognition of the RAVLT. Learning rate and immediate recall was significantly better in PCA compared to tAD, whereas there was no difference in delayed recall. Recognition memory also was not statistically different between patient groups, but PCA patients made significantly more false positive errors than tAD patients. VBM analysis in the PCA patients revealed a significant correlation between total learning and grey matter density in the right supramarginal gyrus, right angular gyrus and left postcentral gyrus. The left post central gyrus also significantly correlated with immediate and delayed recall and with recognition memory. No correlations were detected in the medial temporal lobe. Conclusions: The findings provide novel evidence that early verbal memory impairment is frequently observed in PCA, and is associated with damage to lateral parietal structures. The results have implications for the diagnosis and management of PCA
Structural brain correlates of interpersonal violence: systematic review and voxel-based meta-analysis of neuroimaging studies
Owing to inconsistent nomenclature and results, we have undertaken a label-based review and anatomical likelihood estimation (ALE) meta-analysis of studies measuring the quantitative association between regional grey matter (GM) volume and interpersonal violence. Following PRISMA guidelines, we identified studies by searching 3 online databases (Embase, Medline, PsycInfo) and reference lists. Thirty-five studies were included in the label-based review, providing information for 1288 participants and 86 brain regions. Per region, 0â57% of the results indicated significant reductions in GM volume, while 0â23% indicated significant increases. The only region for which more than half of all results indicated significant reductions was the parietal lobe. However, these results were dispersed across subregions. The ALE meta-analysis, which included 6 whole-brain voxel-based morphometry studies totaling 278 participants and reporting 144 foci, showed no significant clusters of reduced GM volume. No material differences were observed when excluding experiments using reactive violence as outcome or subjects diagnosed with psychopathy. Possible explanations for these findings are phenomenological and etiological heterogeneity, and insufficient power in the label-based review and ALE metaanalysis to detect small effects. We recommend that future studies distinguish between subtypes of interpersonal violence, and investigate mediation by underlying emotional and cognitive processes
A comprehensive analysis of APOE genotype effects on human brain structure in the UK Biobank
Alzheimerâs disease (AD) risk is increased in carriers of the apolipoprotein E (APOE) Δ4 allele and decreased in Δ2 allele carriers compared with the Δ3Δ3 genotype. The aim of this study was to determine whether: the APOE genotype affects brain grey (GM) or white matter (WM) structure; and if differences exist, the age when they become apparent and whether there are differential effects by sex. We used cross-sectional magnetic resonance imaging data from ~43,000 (28,494 after pre-processing) white British cognitively healthy participants (7,446 APOE Δ4 carriers) aged 45â80 years from the UK Biobank cohort and investigated image-derived phenotypes (IDPs). We observed no statistically significant effects of APOE genotype on GM structure volumes or median T2* in subcortical structures, a measure related to iron content. The volume of white matter hyperintensities differed significantly between APOE genotype groups with higher volumes in APOE Δ4Δ4 (effect size 0.14 standard deviations [SD]) and Δ3Δ4 carriers (effect size 0.04âSD) but no differences in Δ2 carriers compared with Δ3Δ3 carriers. WM integrity measures in the dorsal (mean diffusivity [MD]) and ventral cingulum (MD and intracellular volume fraction), posterior thalamic radiation (MD and isotropic volume fraction) and sagittal stratum (MD) indicated lower integrity in APOE Δ4Δ4 carriers (effect sizes around 0.2â0.3âSD) and Δ3Δ4 (effect sizes around 0.05âSD) carriers but no differences in Δ2 carriers compared with the APOE Δ3Δ3 genotype. Effects did not differ between men and women. APOE Δ4 homozygotes had lower WM integrity specifically at older ages with a steeper decline of WM integrity from the age of 60 that corresponds to around 5 years greater âbrain ageâ. APOE genotype affects various white matters measures, which might be indicative of preclinical AD processes. This hypothesis can be assessed in future when clinical outcomes become available
A systematic review of the association between dementia risk factors and cerebrovascular reactivity
Cumulative evidence suggests that impaired cerebrovascular reactivity (CVR), a regulatory response critical for maintaining neuronal health, is amongst the earliest pathological changes in dementia. However, we know little about how CVR is affected by dementia risk, prior to disease onset. Understanding this relationship would improve our knowledge of disease pathways and help inform preventative interventions. This systematic review investigates 59 studies examining how CVR (measured by magnetic resonance imaging) is affected by modifiable, non-modifiable, and clinical risk factors for dementia. We report that non-modifiable risk (older age and apolipoprotein Δ4), some modifiable factors (diabetes, traumatic brain injury, hypertension) and some clinical factors (stroke, carotid artery occlusion, stenosis) were consistently associated with reduced CVR. We also note a lack of conclusive evidence on how other behavioural factors such as physical inactivity, obesity, or depression, affect CVR. This review explores the biological mechanisms underpinning these brain-behaviour associations, highlights evident gaps in the literature, and identifies the risk factors that could be managed to preserve CVR in an effort to prevent dementia
The lifetime accumulation of multimorbidity and its influence on dementia risk: a UK Biobank study
The number of people living with dementia worldwide is projected to reach 150 million by 2050, making prevention a crucial priority for health services. The co-occurrence of two or more chronic health conditions, termed multimorbidity, occurs in up to 80% of dementia patients, raising the potential of multimorbidity as an important risk factor for dementia. However, precise understanding of which specific conditions, as well as their age of onset, drive the link between multimorbidity and dementia is unclear. We defined the patterns of accumulation of 46 chronic conditions over their lifetime in 282,712 individuals from the UK Biobank. By grouping individuals based on their life-history of chronic illness, we show here that risk of incident dementia can be stratified by both the type and timing of their accumulated chronic conditions. We identified several distinct clusters of multimorbidity, and their associated risks varied in an age-specific manner. Compared to low multimorbidity, cardiometabolic and neurovascular conditions acquired before 55 years were most strongly associated with dementia. Acquisition of mental health and neurovascular conditions between the ages of 55 and 70 was associated with an over two-fold increase in dementia risk compared to low multimorbidity. The age-dependent role of multimorbidity in predicting dementia risk could be used for early stratification of individuals into high and low risk groups and inform targeted prevention strategies based on a personâs prior history of chronic disease
- âŠ