176 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

    Get PDF
    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

    A systematic review of protocol studies on conceptual design cognition: design as search and exploration

    Get PDF
    This paper reports findings from the first systematic review of protocol studies focusing specifically on conceptual design cognition, aiming to answer the following research question: What is our current understanding of the cognitive processes involved in conceptual design tasks carried out by individual designers? We reviewed 47 studies on architectural design, engineering design and product design engineering. This paper reports 24 cognitive processes investigated in a subset of 33 studies aligning with two viewpoints on the nature of designing: (V1) design as search (10 processes, 41.7%); and (V2) design as exploration (14 processes, 58.3%). Studies on search focused on solution search and problem structuring, involving: long-term memory retrieval; working memory; operators and reasoning processes. Studies on exploration investigated: co-evolutionary design; visual reasoning; cognitive actions; and unexpected discovery and situated requirements invention. Overall, considerable conceptual and terminological differences were observed among the studies. Nonetheless, a common focus on memory, semantic, associative, visual perceptual and mental imagery processes was observed to an extent. We suggest three challenges for future research to advance the field: (i) developing general models/theories; (ii) testing protocol study findings using objective methods conducive to larger samples and (iii) developing a shared ontology of cognitive processes in design

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

    Get PDF
    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

    A novel systematic approach for analysing exploratory design ideation

    Get PDF
    Two kinds of design ideation process may be distinguished in terms of the problems addressed: (i) solution-focused, i.e. generating solutions to address a fixed problem specifying a desired output; and (ii) exploratory, i.e. considering different interpretations of an open-ended problem and generating associated solutions. Existing systematic analysis approaches focus on the former; the literature is lacking such an approach for the latter. In this paper, we provide a means to systematically analyse exploratory ideation for the first time through a new approach: Analysis of Exploratory Design Ideation (AEDI). AEDI involves: (1) open-ended ideation tasks; (2) coding of explored problems and solutions from sketches; and (3) evaluating ideation performance based on coding. We applied AEDI to 812 concept sketches from 19 open-ended tasks completed during a neuroimaging study of 30 professional product design engineers. Results demonstrate that the approach provides: (i) consistent tasks that stimulate problem exploration; (ii) a reliable means of coding explored problems and solutions; and (iii) an appropriate way to rank/compare designers’ performance. AEDI enables the benefits of systematic analysis (e.g. greater comparability, replicability, and efficiency) to be realised in exploratory ideation research, and studies using open-ended problems more generally. Future improvements include increasing coding validity and reliability

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

    Get PDF
    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

    Primitive Shape Imagery Classification from Electroencephalography

    Get PDF
    Introduction: Brain-computer interfaces (BCIs) augment traditional interfaces for human-computer interaction and provide alternative communication devices to enable the physically impaired to work. Imagined object/shape classification from electroencephalography (EEG) may lead, for example, to enhanced tools for fields such as engineering, design, and the visual arts. Evidence to support such a proposition from non-invasive neuroimaging techniques to date has mainly involved functional magnetic resonance tomography (fMRI) [1] indicating that visual perception and mental imagery show similar brain activity patterns [2] and, although the primary visual cortex has an important role in mental imagery and perception, the occipitotemporal cortex also encodes sensory, semantic and emotional properties during shape imagery [3]. Here we investigate if five imagined primitive shapes (sphere, cone, pyramid, cylinder, cube) can be classified from EEG using filter bank common spatial patterns (FBCSP) [4]. Material, Methods, and Results: Ten healthy volunteers (8 males and 2 females, aged 26-44) participated in a single session study (three runs, four blocks/run, 30 trials/block (i.e., six repetitions of five primitive shapes in random order)). Trials lasted 7s as shown in Fig. 1 and ended with an auditory tone. Thirty EEG channels were recorded with a g.BSamp EEG system using active electrodes (g.tec, Austria). EEG channels with high-level noise were removed. Signals were band-pass filtered in six non-overlapped, 4Hz width bands covering the 4-40Hz frequency range. Filter bank common spatial pattern (FBCSP) based feature extraction and mutual information (MI) based feature selection methods provided input features for 2-class classification using linear discriminant analysis (LDA) for target shape versus the rest, separately. The final 5-class classification was decided by assessing the signed distance in the 2-class discriminant hyperplane for each of the five binary classifiers as shown in Fig. 1. Classifiers were trained on two runs and tested on the one unseen run (i.e., 3 fold cross-validation). A Wilcoxon non-parametric test was used to validate the difference of DA at end of the resting period (-1s) and at the maximal peak accuracy occurring during the shape imagery task (0-3s) is significant (p<0.001). Fig. 1 shows the between-subject average time-varying classification accuracies with standard deviation (shaded area). Discussion: The results indicate that there is separability provided by the shape imagery and there is significantly higher accuracy compared to the ~20% chance level prior the display period with maximum accuracy reaching 34%. In [5] classification of five imagined primitive and complex shapes with 44% accuracy is reported using a 14 channel Emotiv headset. Differences in performance reported may be influenced by EEG recording (EEG in [5] appears to have different dynamics (significant mean shifts)), the study had more sessions/trials, applied ICA for noise removal and the participants had designer experience whilst our study did not. Improvement of our methods is required to achieve higher accuracy rate. It is unclear if an online feedback to shape imagery training and learning will an impact performance – a multisession online study with feedback is the next step in this research. Significance: To best of our knowledge this is only the second study of shape imagery classification from EEG

    Cattle Embryo Growth Development and Viabilty.

    Get PDF
    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)

    Subsistence practices, past biodiversity, and anthropogenic impacts revealed by New Zealand-wide ancient DNA survey

    Get PDF
    New Zealand's geographic isolation, lack of native terrestrial mammals, and Gondwanan origins make it an ideal location to study evolutionary processes. However, since the archipelago was first settled by humans 750 y ago, its unique biodiversity has been under pressure, and today an estimated 49% of the terrestrial avifauna is extinct. Current efforts to conserve the remaining fauna rely on a better understanding of the composition of past ecosystems, as well as the causes and timing of past extinctions. The exact temporal and spatial dynamics of New Zealand's extinct fauna, however, can be difficult to interpret, as only a small proportion of animals are preserved as morphologically identifiable fossils. Here, we conduct a large-scale genetic survey of subfossil bone assemblages to elucidate the impact of humans on the environment in New Zealand. By genetically identifying more than 5,000 nondiagnostic bone fragments from archaeological and paleontological sites, we reconstruct a rich faunal record of 110 species of birds, fish, reptiles, amphibians, and marine mammals. We report evidence of five whale species rarely reported from New Zealand archaeological middens and characterize extinct lineages of leiopelmatid frog (Leiopelma sp.) and kakapo (Strigops habroptilus) haplotypes lost from the gene pool. Taken together, this molecular audit of New Zealand's subfossil record not only contributes to our understanding of past biodiversity and precontact Maori subsistence practices but also provides a more nuanced snapshot of anthropogenic impacts on native fauna after first human arrival

    The effect of vitamin K1 supplemention for 12 months on bone mineral density and indices of vitamin K status and bone turnover in adult Crohn s disease patients

    Get PDF
    peer-reviewedAdult patients with Crohn’s disease (CD), even those in remission, have been shown to have higher circulating under-g-carboxylated osteocalcin (ucOC) concentrations, a sensitive marker of vitamin K nutritional status(1), compared to age- and sex-matched healthy control subjects(2,3). Increased concentrations of ucOC in CD patients in these studies appear to be positively and negatively associated with the rate of bone turnover(3) and bone mineral density (BMD) at some sites(2), respectively. The aim of our study was to investigate whether supplementation with vitamin K1 (1000 mg/d) for 12 months had a positive effect on the rate of bone turnover and BMD in CD patients. We have previously shown that this level of supplementation maximally suppresses the degree of ucOC in CD patients(4).PUBLISHEDpeer-reviewe
    • …
    corecore