47 research outputs found

    Do synaesthesia and mental imagery tap into similar cross-modal processes?

    Get PDF
    Synaesthesia has previously been linked with imagery abilities, although an understanding of a causal role for mental imagery in broader synaesthetic experiences remains elusive. This can be partly attributed to our relatively poor understanding of imagery in sensory domains beyond vision. Investigations into the neural and behavioural underpinnings of mental imagery have nevertheless identified an important role for imagery in perception, particularly in mediating cross-modal interactions. However, the phenomenology of synaesthesia gives rise to the assumption that associated cross-modal interactions may be encapsulated and specific to synaesthesia. As such, evidence for a link between imagery and perception may not generalize to synaesthesia. Here, we present results that challenge this idea: first, we found enhanced somatosensory imagery evoked by visual stimuli of body parts in mirror-touch synaesthetes, relative to other synaesthetes or controls. Moreover, this enhanced imagery generalized to tactile object properties not directly linked to their synaesthetic associations. Second, we report evidence that concurrent experience evoked in grapheme-colour synaesthesia was sufficient to trigger visual-to-tactile correspondences that are common to all. Together, these findings show that enhanced mental imagery is a consistent hallmark of synaesthesia, and suggest the intriguing possibility that imagery may facilitate the cross-modal interactions that underpin synaesthesic experiences. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'

    Perceptual learning shapes multisensory causal inference via two distinct mechanisms

    Get PDF
    To accurately represent the environment, our brains must integrate sensory signals from a common source while segregating those from independent sources. A reasonable strategy for performing this task is to restrict integration to cues that coincide in space and time. However, because multisensory signals are subject to differential transmission and processing delays, the brain must retain a degree of tolerance for temporal discrepancies. Recent research suggests that the width of this 'temporal binding window' can be reduced through perceptual learning, however, little is known about the mechanisms underlying these experience-dependent effects. Here, in separate experiments, we measure the temporal and spatial binding windows of human participants before and after training on an audiovisual temporal discrimination task. We show that training leads to two distinct effects on multisensory integration in the form of (i) a specific narrowing of the temporal binding window that does not transfer to spatial binding and (ii) a general reduction in the magnitude of crossmodal interactions across all spatiotemporal disparities. These effects arise naturally from a Bayesian model of causal inference in which learning improves the precision of audiovisual timing estimation, whilst concomitantly decreasing the prior expectation that stimuli emanate from a common source

    Infrared thermography as a tool to detect hoof lesions in sheep

    Get PDF
    peer-reviewedLameness has a major negative impact on sheep production. The objective of this study was to 1) quantify the repeatability of sheep hoof temperatures estimated using infrared thermography (IRT); 2) determine the relationship between ambient temperature, sheep hoof temperature, and sheep hoof health status; and 3) validate the use of IRT to detect infection in sheep hooves. Three experiments (a repeatability, exploratory, and validation experiment) were conducted over 10 distinct nonconsecutive days. In the repeatability experiment, 30 replicate thermal images were captured from each of the front and back hooves of nine ewes on a single day. In the exploratory experiment, hoof lesion scores, locomotion scores, and hoof thermal images were recorded every day from the same cohort of 18 healthy ewes in addition to a group of lame ewes, which ranged from one to nine ewes on each day. Hoof lesion and locomotion scores were blindly recorded by three independent operators. In the validation experiment, all of the same procedures from the exploratory experiment were applied to a new cohort of 40 ewes across 2 d. The maximum and average temperature of each hoof was extracted from the thermal images. Repeatability of IRT measurements was assessed by partitioning the variance because of ewe and error using mixed models. The relationship between ambient temperature, hoof temperature, and hoof health status was quantified using mixed models. The percentage of hooves correctly classified as healthy (i.e., specificity) and infected (i.e., sensitivity) was calculated for a range of temperature thresholds. Results showed that a small-to-moderate proportion of the IRT-estimated temperature variability in a given hoof was due to error (1.6% to 20.7%). A large temperature difference (8.5 °C) between healthy and infected hooves was also detected. The maximum temperature of infected hooves was unaffected by ambient temperature (P > 0.05), whereas the temperature of healthy hooves was associated with ambient temperature. The best sensitivity (92%) and specificity (91%) results in the exploratory experiment were observed when infected hooves were defined as having a maximum hoof temperature ≥9 °C above the average of the five coldest hooves in the flock on that day. When the same threshold was applied to the validation dataset, a sensitivity of 77% and specificity of 78% was achieved, indicating that IRT could have the potential to detect infection in sheep hooves

    Genetic and economic benefits of foreign sire contributions to a domestic sheep industry; including an Ireland-New Zealand case study

    Get PDF
    peer-reviewedBackground Importation of foreign genetics is a widely used genetic improvement strategy. However, even if the foreign genetic merit is currently greater than the domestic genetic merit, differences in foreign and domestic trends mean that the long-term competitiveness of an importation strategy cannot be guaranteed. Gene flow models are used to quantify the impact that a specific subpopulation, such as foreign genetics, can have over time on the genetic or economic benefit of a domestic industry. Methods We used a deterministic recursive gene flow model to predict the commercial performance of lambs born across various subpopulations. Numerous breeding strategies were evaluated by varying market share, proportions of rams selected for mating, genetic trend, superiority of foreign genetics over domestic genetics and frequency of importation. Specifically, an Ireland-New Zealand case study was simulated to quantify the potential gain that could be made by using foreign sire contributions (New Zealand) in a domestic sheep industry (Ireland). Results Genetic and economic gains were generated from alternative breeding strategies. The ‘base scenario’ (i.e. representing the current industry) predicted an average genetic merit value of €2.51 for lambs born and an annualised cumulative benefit of €45 million (m) after 20 years. Maximum genetic (€9.45 for lambs born) and economic (annualised cumulative benefit of €180 m after 20 years) benefits were achieved by implementing the ‘PRO-intense-market scenario’ which involved shifting market share away from conservative domestic breeders and reducing the proportion of rams that were selected for mating by progressive domestic breeders from the top 40% to the top 20%, without the use of any foreign genetics. The ‘PROFOR scenario’, which considered the use of foreign and progressive domestic genetics, predicted an average genetic merit value of €7.37 for lambs born and an annualised cumulative benefit of €144 m, after 20 years. Conclusions Our results demonstrate that there is opportunity for a domestic industry to increase industry benefits without the use of foreign genetics but through an attempt to shift the market share away from conservative domestic breeders towards progressive domestic breeders. However, the importation and use of progressive foreign genetics may be an effective method to trigger a change in behaviour of conservative domestic breeders towards the use of progressive genetics

    Catchment approach to passive sampling of Irish waters

    Get PDF
    The challenges of monitoring our waters for compliance with WFD and the expansion of the list of organic chemicals that are to be added for monitoring, provides impetus for investigation of alternative monitoring approaches such as passive sampling. The work being carried out represents an important collaboration between two research centres (DCU & MI) together with agency (EA UK and Inland Fisheries Ireland) and industry (TelLab) to assess the potential of passive sampling in monitoring priority pollutants in Ireland. The impact of this study may lie in the establishment of a capability to utilise passive sampling in the monitoring programme in Ireland for WFD. This project pilots the use of passive sampling technology (PDMS and POCIS) combined with biota monitoring to assess the presence of priority substances in Irish surface waters. The project focuses in particular on new pollutants earmarked as candidates for the Annex X priority substances list under the EU Water Framework Directive e.g. E2 and EE2, pharmaceuticals, pesticides, PFOS etc. This considers the implications for compliance with current and proposed EQS and investigates the potential for incorporating passive sampling and biota testing in future compliance, investigative and trend monitoring. . Results of water, biota and passive sampling will be presented together for samples collected in the Dublin catchment. A separate study on the occurrence of the pyrethroid pesticide cypermethrin was also conducted. Several sites along the River Liffey, Dublin, were sampled for pharmaceutical as well as other organic pollutants. A POCIS device was deployed at each location and water samples were collected at T-0 and T-4weeks. There are a number of potential point sources of pollution to this catchment with 3 wastewater treatment plants in the area. Pyrethroids have a low toxicity relative to other pesticides (specifically the organochlorines) so have recently been used in place of more toxic pesticides. Cypermethrin has been shown to accumulate in passive sampling devices. This study involved collection of water samples alongside PDMS and SPMD samplers. Cypermethrin was detected in high levels in the water and PDMS samplers. Passive sampling devices can be a useful supporting technique in a ‘toolbox’ for monitoring within the WFD and other environmental programs. From the investigation of work to date it is clear that passive sampling can play an important role in screening of waters for emerging contaminants, especially for hydrophobic subtances where they could be incorporated into a risk based approach to monitoring. Also, passive sampling has demonstrated that it has a role to play in trend monitoring to illustrate where waters are improving in quality over time, thereby offering the WFD monitoring programme a valuable tool. Keywords: passive sampling, surface waters, coastal waters, WFD

    Task-specific transfer of perceptual learning across sensory modalities

    Get PDF
    It is now widely accepted that primary cortical areas of the brain that were once thought to be sensory-specific undergo significant functional reorganisation following sensory deprivation. For instance, loss of vision or audition leads to the brain areas normally associated with these senses being recruited by the remaining sensory modalities [1]. Despite this, little is known about the rules governing crossmodal plasticity in people who experience typical sensory development, or the potential behavioural consequences. Here, we used a novel perceptual learning paradigm to assess whether the benefits associated with training on a task in one sense transfer to another sense. Participants were randomly assigned to a spatial or temporal task that could be performed visually or aurally, which they practiced for five days; before and after training, we measured discrimination thresholds on all four conditions and calculated the extent of transfer between them. Our results show a clear transfer of learning between sensory modalities; however, generalisation was limited to particular conditions. Specifically, learned improvements on the spatial task transferred from the visual domain to the auditory domain, but not vice versa. Conversely, benefits derived from training on the temporal task transferred from the auditory domain to visual domain, but not vice versa. These results suggest a unidirectional transfer of perceptual learning from dominant to non-dominant sensory modalities and place important constraints on models of multisensory processing and plasticity

    Investigation of intra-day variability of gaseous measurements in sheep using portable accumulation chambers

    Get PDF
    peer-reviewedPortable accumulation chambers (PAC) enable short-term spot measurements of gaseous emissions including methane (CH4), carbon dioxide (CO2), and oxygen (O2) consumption from small ruminants. To date the differences in morning and evening gaseous measurements in the PAC have not been investigated. The objectives of this study were to investigate: 1) the optimal measurement time in the PAC, 2) the appropriate method of accounting for the animal’s size when calculating the animal’s gaseous output, and 3) the intra-day variability of gaseous measurements. A total of 12 ewe lambs (c. 10 to 11 months of age) were randomly selected each day from a cohort of 48 animals over nine consecutive days. Methane emissions from the 12 lambs were measured in 12 PAC during two measurement runs daily, AM (8 to 10 h) and PM (14 to 16 h). Animals were removed from Perennial ryegrass silage for at least 1 h prior to measurements in the PAC and animals were assigned randomly to each of the 12 chambers. Methane (ppm) concentration, O2 and CO2 percentage were measured at 5 time points (T1 = 0.0 min, T2 = 12.5 min, T3 = 25.0 min, T4 = 37.5 min, and T5 = 50.0 min from entry of the first animal into the first chamber) using an Eagle 2 monitor. The correlation between time points T5-T1 (i.e., 50 min minus 0 min after entry of the animal to the chamber) and T4-T1 was 0.95, 0.92, and 0.77 for CH4, O2, and CO2, respectively (P < 0.01). The correlation between CH4 and CO2 output and O2 consumption, calculated with live-weight and with body volume was 0.99 (P < 0.001). The correlation between the PAC measurement recorded on the same animal in the AM and PM measurement runs was 0.73. Factors associated with CH4 production included: day and time of measurement, the live-weight of the animal and the hourly relative humidity. Results from this study suggest that the optimal time for measuring an animal’s gaseous output in the PAC is 50 min, that live-weight should be used in the calculation of gaseous output from an animal and that the measurement of an animal’s gaseous emissions in either the AM or PM does not impact on the ranking of animals when gaseous emissions are measured using the feeding and measurement protocol outlined in the present study.Irish Department of Agricultur

    Phenotypic factors associated with lamb live weight and carcass composition measurements in an Irish multi-breed sheep population

    Get PDF
    peer-reviewedUnderstanding the phenotypic factors that affect lamb live weight and carcass composition is imperative to generating accurate genetic evaluations and further enables implementation of functional management strategies. This study investigated phenotypic factors affecting live weight across the growing season and traits associated with carcass composition in lambs from a multibreed sheep population. Four live weight traits and two carcass composition traits were considered for analysis namely; birth, preweaning, weaning, and postweaning weight, and ultrasound muscle depth and fat depth. A total of 427,927 records from 159,492 lambs collected from 775 flocks between the years 2016 and 2019, inclusive were available from the Irish national sheep database. Factors associated with live weight and carcass composition were determined using linear mixed models. The heaviest birth, preweaning, and weaning weights were associated with single born lambs (P 0.01). Breed class affected lamb live weight and carcass composition with terminal lambs weighing heaviest and having greater muscle depth than all other breed classes investigated (P 90% and ≤100%) resulted in heavier lambs at weaning compared with lambs with lower levels of heterosis coefficients (P < 0.001). A heterosis coefficient class <10% resulted in lambs with greater muscle depth while recombination loss of <10% increased ultrasound fat depth (P < 0.001). Results from this study highlight the impact of multiple animal level factors on lamb live weight and carcass composition which will enable more accurate bio-economic models and genetic evaluations going forward.Irish Department of Agriculture, Food and Marine Research Stimulus Fun

    A study of the SOURCE-TO-SEA occurrence of poly- and perfluoroalkyl substances (PFASs) of emerging concern in Ireland

    Get PDF
    Perfluorinated compounds are ubiquitous. Approximately 4,700 PFAS have been identified to date. Some examples of these products include carpets, glass, paper, clothing, and other textiles, cookware, food packaging, electronics, and personal care products. PFAS have been used in industrial and consumer products since the 1950s due to their physical and chemical properties. PFAS molecules can include oxygen, hydrogen, sulphur, and/or nitrogen atoms, whereas perfluorocarbon molecules contain only carbon and fluorine atoms. Perfluorinated compounds (PFAS) contain a fully fluorinated hydrophobic linear carbon chain attached to one or more hydrophilic head groups. The carbon-fluorine bond is so strong that these chemicals do not degrade in the environment. They are often referred to as ‘forever chemicals’. Some PFAS have been linked to an increased risk of cancer, high cholesterol, reproductive disorders, hormonal disruption or endocrine disruption, and weakening of the immune system. Currently, two PFAS are restricted under the international Stockholm Convention on POPs and the EU POPs Regulation. PFOS (perfluoroctanesulfonic acid) and its derivatives have been restricted since 2009/2010. PFOA (perfluorooctanoic acid), its salts, and related compounds are also regulated as of 4th July 2020. Over the past decades, global manufacturers have started to substitute long-chain PFAS with shorter-chain PFAS or with non-fluorinated substances. This trend has been driven by the fact that the undesired effects of long-chain PFAS on human health and the environment were assessed and recognised first by scientists and authorities around the globe. However short-chain PFAS are now thought to have similar or other properties of concern such as fluorinated compounds like Gen X and ADONA. The combined effects of PFAS are not widely studied and relatively unknown. There is also little biological assessment currently done for drinking water and especially marine water. These are both research gaps, by using biological assessment one can study the cumulative and combined effect of various PFAS on marine species which is what we aim to do in this stud

    Age-Related Sexual Dimorphism in Temporal Discrimination and in Adult-Onset Dystonia Suggests GABAergic Mechanisms

    Get PDF
    Background: Adult-onset isolated focal dystonia (AOIFD) presenting in early adult life is more frequent in men, whereas in middle age it is female predominant. Temporal discrimination, an endophenotype of adult-onset idiopathic isolated focal dystonia, shows evidence of sexual dimorphism in healthy participants. Objectives: We assessed the distinctive features of age-related sexual dimorphism of (i) sex ratios in dystonia phenotypes and (ii) sexual dimorphism in temporal discrimination in unaffected relatives of cervical dystonia patients. Methods: We performed (i) a meta-regression analysis of the proportion of men in published cohorts of phenotypes of adult-onset dystonia in relation to their mean age of onset and (ii) an analysis of temporal discrimination thresholds in 220 unaffected first-degree relatives (125 women) of cervical dystonia patients. Results: In 53 studies of dystonia phenotypes, the proportion of men showed a highly significant negative association with mean age of onset (p \u3c 0.0001, pseudo-R2 = 59.6%), with increasing female predominance from 40 years of age. Age of onset and phenotype together explained 92.8% of the variance in proportion of men. Temporal discrimination in relatives under the age of 35 years is faster in women than men but the age-related rate of deterioration in women is twice that of men; after 45 years of age, men have faster temporal discrimination than women. Conclusion: Temporal discrimination in unaffected relatives of cervical dystonia patients and sex ratios in adult-onset dystonia phenotypes show similar patterns of age-related sexual dimorphism. Such age-related sexual dimorphism in temporal discrimination and adult-onset focal dystonia may reflect common underlying mechanisms. Cerebral GABA levels have been reported to show similar age-related sexual dimorphism in healthy participants and may be the mechanism underlying the observed age-related sexual dimorphism in temporal discrimination and the sex ratios in AOIFD
    corecore