85 research outputs found

    Volitional control of anticipatory ocular smooth pursuit after viewing, but not pursuing, a moving target: evidence for a re-afferent velocity store

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    Although human subjects cannot normally initiate smooth eye movements in the absence of a moving target, previous experiments have established that such movements can be evoked if the subject is required to pursue a regularly repeated, transient target motion stimulus. We sought to determine whether active pursuit was necessary to evoke such an anticipatory response or whether it could be induced after merely viewing the target motion. Subjects were presented with a succession of ramp target motion stimuli of identical velocity and alternating direction in the horizontal axis. In initial experiments, the target was exposed for only 120 ms as it passed through centre, with a constant interval between presentations. Ramp velocity was varied from +/- 9 to 45 degrees/s in one set of trials; the interval between ramp presentations was varied from 640 to 1920 ms in another. Subjects were instructed either to pursue the moving target from the first presentation or to hold fixation on another, stationary target during the first one, two or three presentations of the moving display. Without fixation, the first smooth movement was initiated with a mean latency of 95 ms after target onset, but with repeated presentations anticipatory smooth movements started to build up before target onset. In contrast, when the subjects fixated the stationary target for three presentations of the moving target, the first movement they made was already anticipatory and had a peak velocity that was significantly greater than that of the first response without prior fixation. The conditions of experiment 1 were repeated in experiment 3 with a longer duration of target exposure (480 ms), to allow higher eye velocities to build up. Again, after three prior fixations, the anticipatory velocity measured at 100 ms after target onset (when visual feedback would be expected to start) was not significantly different to that evoked after the subjects had made three active pursuit responses to the same target motion, reaching a mean of 20 degrees/s for a 50 degrees/s target movement. In a further experiment, we determined whether subjects could use stored information from prior active pursuit to generate anticipatory pursuit in darkness if there was a high expectancy that the target would reappear with identical velocity. Subjects made one predictive response immediately after target disappearance, but very little response thereafter until the time at which they expected the target to reappear, when they were again able to re-vitalize the anticipatory response before target appearance. The findings of these experiments provide evidence that information related to target velocity can be stored and used to generate future anticipatory responses even in the absence of eye movement. This suggests that information for storage is probably derived from a common pre-motor drive signal that is inhibited during fixation, rather than an efference copy of eye movement itself. Furthermore, a high level of expectancy of target appearance can facilitate the release of this stored information in darkness

    Mind-body and creative arts therapies for people with aphasia: a mixed-method systematic review

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    Background. In the context of aphasia rehabilitation there is a perceived need for interventions with a reduced linguistic demand targeting well-being. Mind-body and creative arts approaches are holistic and person-centred approaches, primarily relying on means other than verbal exchanges, and promoting self-regulation strategies. Aims. This mixed-method systematic review aimed to evaluate the availability, feasibility, and effectiveness of mind-body and creative arts therapies in promoting well-being for people with aphasia. Eight databases were searched using subject headings and key words. Full-text screening, critical appraisal and data extraction were conducted independently by two reviewers. A segregated synthesis approach was used (i.e. Revised Effect Direction Plot technique; Thematic Synthesis approach). Findings are presented in a narrative and visual form. Main Contribution. Twenty-two studies were included (Mind-body: n=11; Creative-arts: n=11). Heterogeneity of study design and quality, intervention type, procedures and dosage, outcomes, and level of offered communication support were identified. Improvements were noted across a wide range of well-being outcomes with more consistent positive results for anxiety and communication. 128 findings were extracted and synthetised in three broad themes: positive impact on self, empowering multifaceted experience, the relevance of needs-centred adjustments. Conclusion. Provisional findings about the benefits of mind-body and creative arts interventions on aspects of well-being for some individuals with aphasia were identified. However, findings are complex and need to be interpreted cautiously. Facilitators and barriers to these therapies are highlighted with related recommendations for practice. The review poses a demand for further research in the field, implementing rigorous methodology and aphasia-specific support to facilitate inclusion and engagement

    HEADS : UP Aphasia: co-creating a mindfulness-based course for stroke survivors with aphasia. Findings from a professional stakeholder survey

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    Background and aims: One third of stroke survivors lives with aphasia. Although anxiety and depression are common among people with aphasia (pwa), due to their complex communication needs these individuals are frequently excluded from therapeutic interventions with negative consequences on their mental health. HEADS: UP Aphasia is a Stroke Association-funded PhD research study which aims to co-create an aphasia-friendly version of HEADS: UP (Helping Ease Anxiety and Depression following Stroke; https://bit.ly/2QbB0cV), a stroke-specific adaptation of Kabat-Zinn's Mindfulness-based Stress Reduction (MBSR) course. Methods: The study was conducted online. In stage 3 of the research a social media strategy was used to recruit health professionals (HPs). Participants were invited to complete a 10-min bespoke questionnaire structured around the TIDieR checklist (Hoffmann et al., 2014) and delivered via RedCap. Questions focused on potential adjustments to be considered during subsequent co-creation/adaptation work. Closed questions were supplement by the option to 'comment'. Quantitative questionnaire data were analysed using descriptive statistics e.g. distribution and frequency; qualitative data using thematic analysis. Results: Twenty-eight HPs were recruited; n=25 professionals completed the survey (n=3 not completed). Key findings: delivery mode: 48% (n=12) 'blended'; setting: 68% (n=17) 'mix of 1:1 and group sessions'; session frequency: 44.4% (n=12) 'once weekly'. Explanatory comments helped identify potential facilitators and barriers e.g. group for peer support. Conclusions: The results offer a professional perspective of pwa's needs and priorities in the context of a complex psychosocial self-management intervention, and will guide the decision-making during subsequent HEADS: UP Aphasia co-development processes

    Cattle Embryo Growth Development and Viabilty.

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    End of Project ReportA major problem for the cattle breeding industry is the high rate of early embryo loss which compromises reproductive efficiency and genetic improvement, resulting in serious financial loss to farmers. An important part of the Teagasc research programme in this area is the investigation of basic parameters of cattle embryo growth, development and viability during the critical period when most of the embryo loss occurs. We have now characterised this period of embryo development and to our knowledge, this is the first report describing the morphology, growth rate, protein content and metabolic activity of cattle embryos during this period. The main results are summarised here and detailed results have been published in the papers listed at the end of this report. Embryo growth rate and protein content increased exponentially between days 8 and 13 after fertilisation. Furthermore, there was a high rate of protein synthetic activity, energy and amino acid metabolism and signal transduction activity, all reaching a peak between days 8 and 13 after fertilisation. Because of the high rate of metabolic activity evident during this time it is likely that the embryos are very susceptible to environmental changes that have the potential to interfere with normal developmental mechanisms. The results arising from this project suggest that the critical period of early embryo loss in cattle may now be narrowed to a time window of day 8 to 13 rather than day 8 to 16 as presumed up to now. The main results are summarised.European Union 4th Framework Programme (Contract CT-95-0190)

    Insights into design concept similarity judgements

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    Similarity has been shown to influence various measures of outcome creativity in combinatorial design tasks, but the role of similarity during the combination of design concepts is unknown. As an initial step towards understanding design concept similarity we review prominent models of similarity processing, highlight challenges with adoption in a design context, and carry out an exploratory experimental investigation of design concept similarity perception. Similarity may be the result of structural alignment processing and similarity ratings appear to vary with the number of commonalities

    Plasma levels of matrix metalloproteinase-2, -3, -10, and tissue inhibitor of metalloproteinase-1 are associated with vascular complications in patients with type 1 diabetes: The EURODIAB Prospective Complications Study

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    Impaired regulation of extracellular matrix remodeling by matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) may contribute to vascular complications in patients with type 1 diabetes. We investigated associations between plasma MMP-1, -2, -3, -9, -10 and TIMP-1, and cardiovascular disease (CVD) or microvascular complications in type 1 diabetic patients. We also evaluated to which extent these associations could be explained by low-grade inflammation (LGI) or endothelial dysfunction (ED). Methods: 493 type 1 diabetes patients (39.5 ± 9.9 years old, 51% men) from the EURODIAB Prospective Complications Study were included. Linear regression analysis was applied to investigate differences in plasma levels of MMP-1, -2, -3, -9, -10, and TIMP-1 between patients with and without CVD, albuminuria or retinopathy. All analyses were adjusted for age, sex, duration of diabetes, Hba1c and additionally for other cardiovascular risk factors including LGI and ED. Results: Patients with CVD (n = 118) showed significantly higher levels of TIMP-1 [β = 0.32 SD (95%CI: 0.12; 0.52)], but not of MMPs, than patients without CVD (n = 375). Higher plasma levels of MMP-2, MMP-3, MMP-10 and TIMP-1 were associated with higher levels of albuminuria (p-trends were 0.028, 0.004, 0.005 and 0.001, respectively). Severity of retinopathy was significantly associated with higher levels of MMP-2 (p-trend = 0.017). These associations remained significant after further adjustment for markers of LGI and ED. Conclusions: These data support the hypothesis that impaired regulation of matrix remodeling by actions of MMP-2, -3 and-10 and TIMP-1 contributes to the pathogenesis of vascular complications in type 1 diabetes

    Relationship Between Risk Factors and Mortality in Type 1 Diabetic Patients in Europe: The EURODIAB Prospective Complications Study (PCS)

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    OBJECTIVE—The purpose of this study was to examine risk factors for mortality in patients with type 1 diabetes

    Perceiving What Is Reachable Depends on Motor Representations: Evidence from a Transcranial Magnetic Stimulation Study

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    Background: Visually determining what is reachable in peripersonal space requires information about the egocentric location of objects but also information about the possibilities of action with the body, which are context dependent. The aim of the present study was to test the role of motor representations in the visual perception of peripersonal space. Methodology: Seven healthy participants underwent a TMS study while performing a right-left decision (control) task or perceptually judging whether a visual target was reachable or not with their right hand. An actual grasping movement task was also included. Single pulse TMS was delivered 80 % of the trials on the left motor and premotor cortex and on a control site (the temporo-occipital area), at 90 % of the resting motor threshold and at different SOA conditions (50ms, 100ms, 200ms or 300ms). Principal Findings: Results showed a facilitation effect of the TMS on reaction times in all tasks, whatever the site stimulated and until 200ms after stimulus presentation. However, the facilitation effect was on average 34ms lower when stimulating the motor cortex in the perceptual judgement task, especially for stimuli located at the boundary of peripersonal space. Conclusion: This study provides the first evidence that brain motor area participate in the visual determination of what is reachable. We discuss how motor representations may feed the perceptual system with information about possibl
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