68 results on '"Miellet S"'
Search Results
2. General introduction: Urban politics of human rights
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Oomen, B., Durmuş, E., Miellet, S., Nijman, J.E., Roodenburg, L., Sociologie van de mensenrechten, Dep Rechtsgeleerdheid (external) - Roosevelt Academy, Montaigne Centrum voor Rechtspleging en conflictoplossing, Public management en publieke innovaties, UU LEG Research USG Public Matters, ACIL (FdR), and FdR overig onderzoek
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Human rights and the urban – two concepts that both seem to quiver with hope, promise and potential. Songs, selfies and cinematography praising city life conjure images of growth, freedom and emancipation. The slums behind the shiny facades, the people begging next to high rise banks, the divergent life-worlds and opportunities of children in a single city. The different contributions highlight the involvement of a myriad of actors who use human rights, for instance, to respond to urbanisation processes. At the same time, this volume is mindful of critics who argue, for instance, that human rights city initiatives may preserve the state-centric human rights framework, by emphasising local ‘state actors’ and by only indirectly recognising the role of other local actors, such as community-based groups and social movements. The urban condition is often argued to define future life on the planet.
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- 2022
3. Making neurons, made easy: The use of Neurogenin-2 in neuronal differentiation
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Hulme, AJ, Maksour, S, Glover, MS-C, Miellet, S, Dottori, M, Hulme, AJ, Maksour, S, Glover, MS-C, Miellet, S, and Dottori, M
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Directed neuronal differentiation of human pluripotent stem cells (hPSCs), neural progenitors, or fibroblasts using transcription factors has allowed for the rapid and highly reproducible differentiation of mature and functional neurons. Exogenous expression of the transcription factor Neurogenin-2 (NGN2) has been widely used to generate different populations of neurons, which have been used in neurodevelopment studies, disease modeling, drug screening, and neuronal replacement therapies. Could NGN2 be a "one-glove-fits-all" approach for neuronal differentiations? This review summarizes the cellular roles of NGN2 and describes the applications and limitations of using NGN2 for the rapid and directed differentiation of neurons.
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- 2022
4. Molecular and Functional Characterization of Neurogenin-2 Induced Human Sensory Neurons
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Hulme, AJ, McArthur, JR, Maksour, S, Miellet, S, Ooi, L, Adams, DJ, Finol-Urdaneta, RK, Dottori, M, Hulme, AJ, McArthur, JR, Maksour, S, Miellet, S, Ooi, L, Adams, DJ, Finol-Urdaneta, RK, and Dottori, M
- Abstract
Sensory perception is fundamental to everyday life, yet understanding of human sensory physiology at the molecular level is hindered due to constraints on tissue availability. Emerging strategies to study and characterize peripheral neuropathies in vitro involve the use of human pluripotent stem cells (hPSCs) differentiated into dorsal root ganglion (DRG) sensory neurons. However, neuronal functionality and maturity are limited and underexplored. A recent and promising approach for directing hPSC differentiation towards functionally mature neurons involves the exogenous expression of Neurogenin-2 (NGN2). The optimized protocol described here generates sensory neurons from hPSC-derived neural crest (NC) progenitors through virally induced NGN2 expression. NC cells were derived from hPSCs via a small molecule inhibitor approach and enriched for migrating NC cells (66% SOX10+ cells). At the protein and transcript level, the resulting NGN2 induced sensory neurons (NGN2iSNs) express sensory neuron markers such as BRN3A (82% BRN3A+ cells), ISLET1 (91% ISLET1+ cells), TRKA, TRKB, and TRKC. Importantly, NGN2iSNs repetitively fire action potentials (APs) supported by voltage-gated sodium, potassium, and calcium conductances. In-depth analysis of the molecular basis of NGN2iSN excitability revealed functional expression of ion channels associated with the excitability of primary afferent neurons, such as Nav1.7, Nav1.8, Kv1.2, Kv2.1, BK, Cav2.1, Cav2.2, Cav3.2, ASICs and HCN among other ion channels, for which we provide functional and transcriptional evidence. Our characterization of stem cell-derived sensory neurons sheds light on the molecular basis of human sensory physiology and highlights the suitability of using hPSC-derived sensory neurons for modeling human DRG development and their potential in the study of human peripheral neuropathies and drug therapies.
- Published
- 2020
5. Distribution of Particles in Human Stem Cell-Derived 3D Neuronal Cell Models: Effect of Particle Size, Charge, and Density
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Czuba-Wojnilowicz, E, Miellet, S, Glab, A, Viventi, S, Cavalieri, F, Cortez-Jugo, C, Dottori, M, Caruso, F, Czuba-Wojnilowicz, E, Miellet, S, Glab, A, Viventi, S, Cavalieri, F, Cortez-Jugo, C, Dottori, M, and Caruso, F
- Abstract
Neurodegenerative diseases are generally characterized by a progressive loss of neuronal subpopulations, with no available cure to date. One of the main reasons for the limited clinical outcomes of new drug formulations is the lack of appropriate in vitro human cell models for research and validation. Stem cell technologies provide an opportunity to address this challenge by using patient-derived cells as a platform to test various drug formulations, including particle-based drug carriers. The therapeutic efficacy of drug delivery systems relies on efficient cellular uptake of the carrier and can be dependent on its size, shape, and surface chemistry. Although considerable efforts have been made to understand the effects of the physiochemical properties of particles on two-dimensional cell culture models, little is known of their effect in three-dimensional (3D) cell models of neurodegenerative diseases. Herein, we investigated the role of particle size (235-1000 nm), charge (cationic and anionic), and density (1.05 and 1.8 g cm-3) on the interactions of particles with human embryonic stem cell-derived 3D cell cultures of sensory neurons, called sensory neurospheres (sNSP). Templated layer-by-layer particles, with silica or polystyrene cores, and self-assembled glycogen/DNA polyplexes were used. Particles with sizes <280 nm effectively penetrated sNSP. Additionally, effective plasmid DNA delivery was observed up to 6 days post-transfection with glycogen/DNA polyplexes. The findings provide guidance in nanoparticle design for therapies aimed at neurodegenerative diseases, in particular Friedreich's ataxia, whereby sensory neurons are predominantly affected. They also demonstrate the application of 3D models of human sensory neurons in preclinical drug development.
- Published
- 2020
6. Super-Memorizers Are Not Super-Recognizers
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Ramon, M., Miellet, S., Dzieciol, A.M., Konrad, B.N., Dresler, M., Caldara, R., Ramon, M., Miellet, S., Dzieciol, A.M., Konrad, B.N., Dresler, M., and Caldara, R.
- Abstract
Contains fulltext : 168165.PDF (publisher's version ) (Open Access), Humans have a natural expertise in recognizing faces. However, the nature of the interaction between this critical visual biological skill and memory is yet unclear. Here, we had the unique opportunity to test two individuals who have had exceptional success in the World Memory Championships, including several world records in face-name association memory. We designed a range of face processing tasks to determine whether superior/expert face memory skills are associated with distinctive perceptual strategies for processing faces. Superior memorizers excelled at tasks involving associative face-name learning. Nevertheless, they were as impaired as controls in tasks probing the efficiency of the face system: face inversion and the other-race effect. Super memorizers did not show increased hippocampal volumes, and exhibited optimal generic eye movement strategies when they performed complex multi-item face-name associations. Our data show that the visual computations of the face system are not malleable and are robust to acquired expertise involving extensive training of associative memory.
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- 2016
7. iMap Motion: Validating a Novel Method for Statistical Fixation Mapping of Temporal Eye Movement Data
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Liu, Y., primary, Lao, J., additional, Miellet, S., additional, Kuhn, G., additional, and Caldara, R., additional
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- 2013
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8. Visual and embodied perception of others: The neural correlates of the "Body Gestalt" effect
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Miellet, S., primary, Hoogenboom, N., additional, and Kessler, K., additional
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- 2012
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9. Local Jekyll and global Hyde: The dual identity of face identification
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Miellet, S., primary, Caldara, R., additional, and Schyns, P. G., additional
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- 2011
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10. Eyes like it, brain likes it: Tracking the neural tuning of cultural diversity in eye movements for faces
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Lao, J., primary, Miellet, S., additional, Vizioli, L., additional, Fusco, R., additional, and Caldara, R., additional
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- 2011
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11. Perceiving Conspecifics is Not Purely Visual: “Body Gestalt” Completion is Influenced by the Body Posture of the Observer
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Kessler, K, primary, Miellet, S, additional, and Hoogenboom, N, additional
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- 2011
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12. When East meets West: gaze-contingent Blindspots abolish cultural diversity in eye movements for faces
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Miellet, S., primary and Caldara, R., additional
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- 2010
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13. Tracking qualitative and quantitative information use during face recognition with a dynamic Spotlight
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Vizioli, L., primary, Miellet, S., additional, and Caldara, R., additional
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- 2010
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14. Investigating cultural diversity for extrafoveal information use in visual scenes
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Miellet, S., primary, Zhou, X., additional, He, L., additional, Rodger, H., additional, and Caldara, R., additional
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- 2010
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15. Face recognition subserves nature not nurture
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Caldara, R., primary, Miellet, S., additional, and Zhou, X., additional
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- 2010
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16. Cultural diversity in eye movements extends across biological and artificial visual categories
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Kelly, D. J., primary, Miellet, S., additional, and Caldara, R., additional
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- 2010
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17. Social experience does not abolish cultural diversity in eye movements for faces
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De Luca, E., primary, Kelly, D. J., additional, Miellet, S., additional, Foreman, K., additional, and Caldara, R., additional
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- 2010
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18. Face information sampling in super-recognizers
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Dunn, JD, de Lima Varela, VP, Nicholls, VI, Papinutto, M, White, D, Miellet, S, Dunn, JD, de Lima Varela, VP, Nicholls, VI, Papinutto, M, White, D, and Miellet, S
- Abstract
Perceptual processes underlying individual differences in face recognition ability remain poorly understood. We compared visual sampling of 37 super-recognizers – individuals with superior face recognition ability – to typical viewers by measuring gaze position as they learned and recognized unfamiliar faces. In both phases, participants viewed faces through ‘spotlight’ apertures that varied in size, with face information restricted in real-time around their point of fixation. We found higher accuracy in super-recognizers at all aperture sizes – showing their superiority does not rely on global sampling of face information, but is also evident when forced to adopt piecemeal sampling. In addition, super-recognizers made more fixations, focused less on the eye region and distributed their gaze more broadly than typical viewers. These differences were most apparent when learning faces, and were consistent with trends we observed across the broader ability spectrum, suggesting that they are reflective of factors that vary dimensionally in the broader population.
19. Visual information sampling of faces by super-recognisers
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Dunn, JD, Nicholls, VI, Papinutto, M, Varela, VPL, White, D, Miellet, S, Dunn, JD, Nicholls, VI, Papinutto, M, Varela, VPL, White, D, and Miellet, S
20. The impact of perceptual complexity on road crossing decisions in younger and older adults.
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Nicholls, V. I., Wiener, Jan, Meso, A. I., Miellet, S., Nicholls, V. I., Wiener, Jan, Meso, A. I., and Miellet, S.
- Abstract
Cognitive abilities decline with healthy ageing which can have a critical impact on day-to-day activities. One example is road crossing where older adults (OAs) disproportionally fall victim to pedestrian accidents. The current research examined two virtual reality experiments that investigated how the complexity of the road crossing situation impacts OAs (N = 19, ages 65-85) and younger adults (YAs, N = 34, ages 18-24) with a range of executive functioning abilities (EFs). Overall, we found that OAs were able to make safe crossing decisions, and were more cautious than YAs. This continued to be the case in high cognitive load situations. In these situations, safe decisions were associated with an increase in head movements for participants with poorer attention switching than participants with better attention switching suggesting these groups developed compensation strategies to continue to make safe decisions. In situations where participants had less time to make a crossing decision all participants had difficulties making safe crossing decisions which was amplified for OAs and participants with poorer EFs. Our findings suggest more effort should be taken to ensure that road crossing points are clear of visual obstructions and more speed limits should be placed around retirement or care homes, neither of which are legislated for in the UK and Australia.
21. Exploring the relevance of NUP93 variants in steroid-resistant nephrotic syndrome using next generation sequencing and a fly kidney model.
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Bierzynska, A., Bull, K., Miellet, S., Dean, P., Neal, C., Colby, E., McCarthy, H. J., Hegde, S., Sinha, M. D., Bugarin Diz, C., Stirrups, K., Megy, K., Mapeta, R., Penkett, C., Marsh, S., Forrester, N., Afzal, M., Stark, H., BioResource, N., Williams, M., Welsh, G. I., Koziell, A. B., Hartley, Paul S., Saleem, M. A., Bierzynska, A., Bull, K., Miellet, S., Dean, P., Neal, C., Colby, E., McCarthy, H. J., Hegde, S., Sinha, M. D., Bugarin Diz, C., Stirrups, K., Megy, K., Mapeta, R., Penkett, C., Marsh, S., Forrester, N., Afzal, M., Stark, H., BioResource, N., Williams, M., Welsh, G. I., Koziell, A. B., Hartley, Paul S., and Saleem, M. A.
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BACKGROUND: Variants in genes encoding nuclear pore complex (NPC) proteins are a newly identified cause of paediatric steroid-resistant nephrotic syndrome (SRNS). Recent reports describing NUP93 variants suggest these could be a significant cause of paediatric onset SRNS. We report NUP93 cases in the UK and demonstrate in vivo functional effects of Nup93 depletion in a fly (Drosophila melanogaster) nephrocyte model. METHODS: Three hundred thirty-seven paediatric SRNS patients from the National cohort of patients with Nephrotic Syndrome (NephroS) were whole exome and/or whole genome sequenced. Patients were screened for over 70 genes known to be associated with Nephrotic Syndrome (NS). D. melanogaster Nup93 knockdown was achieved by RNA interference using nephrocyte-restricted drivers. RESULTS: Six novel homozygous and compound heterozygous NUP93 variants were detected in 3 sporadic and 2 familial paediatric onset SRNS characterised histologically by focal segmental glomerulosclerosis (FSGS) and progressing to kidney failure by 12 months from clinical diagnosis. Silencing of the two orthologs of human NUP93 expressed in D. melanogaster, Nup93-1, and Nup93-2 resulted in significant signal reduction of up to 82% in adult pericardial nephrocytes with concomitant disruption of NPC protein expression. Additionally, nephrocyte morphology was highly abnormal in Nup93-1 and Nup93-2 silenced flies surviving to adulthood. CONCLUSION: We expand the spectrum of NUP93 variants detected in paediatric onset SRNS and demonstrate its incidence within a national cohort. Silencing of either D. melanogaster Nup93 ortholog caused a severe nephrocyte phenotype, signaling an important role for the nucleoporin complex in podocyte biology. A higher resolution version of the Graphical abstract is available as Supplementary information.
22. In pursuit of visual attention: SSVEP frequency-tagging moving targets.
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de Lissa, P., Caldara, R., Nicholls, Victoria, Miellet, S., de Lissa, P., Caldara, R., Nicholls, Victoria, and Miellet, S.
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Previous research has shown that visual attention does not always exactly follow gaze direction, leading to the concepts of overt and covert attention. However, it is not yet clear how such covert shifts of visual attention to peripheral regions impact the processing of the targets we directly foveate as they move in our visual field. The current study utilised the co-registration of eye-position and EEG recordings while participants tracked moving targets that were embedded with a 30 Hz frequency tag in a Steady State Visually Evoked Potentials (SSVEP) paradigm. When the task required attention to be divided between the moving target (overt attention) and a peripheral region where a second target might appear (covert attention), the SSVEPs elicited by the tracked target at the 30 Hz frequency band were significantly, but transiently, lower than when participants did not have to covertly monitor for a second target. Our findings suggest that neural responses of overt attention are only briefly reduced when attention is divided between covert and overt areas. This neural evidence is in line with theoretical accounts describing attention as a pool of finite resources, such as the perceptual load theory. Altogether, these results have practical implications for many real-world situations where covert shifts of attention may discretely reduce visual processing of objects even when they are directly being tracked with the eyes.
23. Flexible use of facial features supports face identity processing.
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Dunn JD, Towler A, Popovic B, de Courcey A, Lee NY, Kemp RI, Miellet S, and White D
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- Humans, Female, Adult, Young Adult, Male, Adolescent, Recognition, Psychology physiology, Facial Recognition physiology
- Abstract
People prioritize diagnostic features in classification tasks. However, it is not clear whether this priority is fixed or is flexibly applied depending on the specific classification decision, or how feature use behavior contributes to individual differences in performance. Here we examined whether flexibility in features used in a face identification task supports face recognition ability. In Experiment 1, we show that the facial features most useful for identification vary-to a surprising degree-depending on the specific face identity comparison at hand. While the ears and eyes were the most diagnostic for face identification in general, they were the most diagnostic feature for just 22% and 14% of identity decisions, respectively. In three subsequent experiments, we find that flexibility in feature use contributes to an individual's face identity matching ability. Higher face identification accuracy was associated with being aware of (Experiments 2 and 4) and attending to (Experiments 3 and 4) the most diagnostic features for a specific facial comparison. This conferred an enhanced benefit relative to focusing on features that were diagnostic of face identity decisions in general (Experiment 4). We conclude that adaptability in information sampling supports face recognition ability and discuss theoretical and applied implications. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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- 2024
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24. Information sampling differences supporting superior face identity processing ability.
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Dunn JD, Miellet S, and White D
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Face recognition in humans is often cited as a model example of perceptual expertise that is characterized by an increased tendency to process faces as holistic percepts. However emerging evidence across different domains of expertise points to a critical role of feature-based processing strategies during the initial encoding of information. Here, we examined the eye-movement patterns of super-recognisers-individuals with extremely high face identification ability compared with the average person-using gaze-contingent "spotlight" apertures that restrict visual face information in real time around their point of fixation. As an additional contrast, we also compared their performance with that of facial examiners-highly trained individuals whose superiority has been shown to rely heavily on featural processing. Super-recognisers and facial examiners showed equivalent face matching accuracy in both spotlight aperture and natural viewing conditions, suggesting that they were equally adept at using featural information for face identity processing. Further, both groups sampled more information across the face than controls. Together, these results show that the active exploration of facial features is an important determinant of face recognition ability that generalizes across different types of experts., (© 2024. The Author(s).)
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- 2024
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25. Generation of genetically modified Friedreich's ataxia induced pluripotent stem cell lines and isogenic control lines carrying an inducible neurogenin-2 expression cassette.
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Miellet S, Maddock M, Napierala JS, Napierala M, and Dottori M
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- Humans, Cell Line, Cell Differentiation, Frataxin, Friedreich Ataxia genetics, Friedreich Ataxia pathology, Friedreich Ataxia metabolism, Induced Pluripotent Stem Cells metabolism, Basic Helix-Loop-Helix Transcription Factors metabolism, Basic Helix-Loop-Helix Transcription Factors genetics, Nerve Tissue Proteins metabolism, Nerve Tissue Proteins genetics
- Abstract
Friedreich's ataxia (FRDA) is a rare neurodegenerative disease caused by an expansion of a GAA repeat sequence within the Frataxin (FXN) gene. Prominent regions of neurodegeneration include sensory neurons within the dorsal root ganglia. Here we present a set of genetically modified FRDA induced pluripotent stem cell (iPSC) lines that carry an inducible neurogenin-2 (NGN2) expression cassette. Exogenous expression of NGN2 in iPSC derived neural crest progenitors efficiently generates functionally mature sensory neurons. These cell lines will provide a streamlined source of FRDA iPSC sensory neurons for studying both disease mechanism and screening potential therapeutics., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: M Dottori collaborates with Dmitry A. Ovchinnikov, who is an editor for Stem Cell Research. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
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- 2024
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26. Parsing the effect of co-culture with brain organoids on Diffuse Intrinsic Pontine Glioma (DIPG) using quantitative proteomics.
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Prior VG, Maksour S, Miellet S, Hulme AJ, Chen Y, Mirzaei M, Wu Y, Dottori M, and O'Neill GM
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- Humans, Diffuse Intrinsic Pontine Glioma pathology, Diffuse Intrinsic Pontine Glioma metabolism, Diffuse Intrinsic Pontine Glioma genetics, Cell Line, Tumor, Brain metabolism, Brain pathology, Proteome metabolism, Glioma pathology, Glioma metabolism, Tumor Microenvironment, Coculture Techniques, Organoids metabolism, Organoids pathology, Proteomics methods, Brain Stem Neoplasms pathology, Brain Stem Neoplasms metabolism, Brain Stem Neoplasms genetics
- Abstract
Diffuse Intrinsic Pontine Gliomas (DIPGs) are deadly brain cancers in children for which there is no effective treatment. This can partly be attributed to preclinical models that lack essential elements of the in vivo tissue environment, resulting in treatments that appear promising preclinically, but fail to result in effective cures. Recently developed co-culture models combining stem cell-derived brain organoids with brain cancer cells provide tissue dimensionality and a human-relevant tissue-like microenvironment. As these models are technically challenging, we aimed to establish whether interaction with the organoid influences DIPG biology and thus warrants their use. To address this question DIPG24 cells were cultured with pluripotent stem cell-derived cortical organoids. We created "mosaic" co-cultures enriched for tumour cell-neuronal cell interactions versus "assembloid" co-cultures enriched for tumour cell-tumour cell interactions. Sequential window acquisition of all theoretical mass spectra (SWATH-MS) was used to analyse the proteomes of DIPG fractions isolated by flow-assisted cell sorting. Control proteomes from DIPG spheroids were compared with DIPG cells isolated from mosaic and assembloid co-cultures. This suggested changes in cell interaction with the external environment reflected by decreased gene ontology terms associated with adhesion and extracellular matrix, and increased DNA synthesis and replication, in DIPG24 cells under either co-culture condition. By contrast, the mosaic co-culture was associated with neuron-specific brahma-associated factor (nBAF) complex signalling, a process associated with neuronal maturation. We propose that co-culture with brain organoids is a valuable tool to parse the contribution of the brain microenvironment to DIPG tumour biology., Competing Interests: Declaration of Competing Interest The authors have no relevant financial or non-financial interests to disclose., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)
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- 2024
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27. Efficient fabrication of 3D bioprinted functional sensory neurons using an inducible Neurogenin-2 human pluripotent stem cell line.
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St Clair-Glover M, Finol-Urdaneta RK, Maddock M, Wallace E, Miellet S, Wallace G, Yue Z, and Dottori M
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- Humans, Cell Line, Pluripotent Stem Cells cytology, Pluripotent Stem Cells metabolism, Cell Differentiation, Tissue Engineering methods, Gelatin chemistry, Neural Crest cytology, Neural Crest metabolism, Printing, Three-Dimensional, Bioprinting methods, Basic Helix-Loop-Helix Transcription Factors metabolism, Basic Helix-Loop-Helix Transcription Factors genetics, Sensory Receptor Cells metabolism, Sensory Receptor Cells cytology, Nerve Tissue Proteins metabolism, Tissue Scaffolds chemistry
- Abstract
Three-dimensional (3D) tissue models have gained recognition for their improved ability to mimic the native cell microenvironment compared to traditional two-dimensional models. This progress has been driven by advances in tissue-engineering technologies such as 3D bioprinting, a promising method for fabricating biomimetic living tissues. While bioprinting has succeeded in generating various tissues to date, creating neural tissue models remains challenging. In this context, we present an accelerated approach to fabricate 3D sensory neuron (SN) structures using a transgenic human pluripotent stem cell (hPSC)-line that contains an inducible Neurogenin-2 (NGN2) expression cassette. The NGN2 hPSC line was first differentiated to neural crest cell (NCC) progenitors, then incorporated into a cytocompatible gelatin methacryloyl-based bioink for 3D bioprinting. Upregulated NGN2 expression in the bioprinted NCCs resulted in induced SN (iSN) populations that exhibited specific cell markers, with 3D analysis revealing widespread neurite outgrowth through the scaffold volume. Calcium imaging demonstrated functional activity of iSNs, including membrane excitability properties and voltage-gated sodium channel (Na
V ) activity. This efficient approach to generate 3D bioprinted iSN structures streamlines the development of neural tissue models, useful for the study of neurodevelopment and disease states and offering translational potential., (Creative Commons Attribution license.)- Published
- 2024
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28. A confirmation of the predictive utility of the Antibiotic Use Questionnaire.
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Miellet S, Byrne MK, Reynolds N, and Sweetnam T
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- Humans, Surveys and Questionnaires, Female, Male, Adult, Middle Aged, Australia, Health Knowledge, Attitudes, Practice, Cohort Studies, Reproducibility of Results, Young Adult, Pilot Projects, Aged, China, Anti-Bacterial Agents therapeutic use
- Abstract
Background: The change in the efficacy of antimicrobial agents due to their misuse is implicated in extensive health and mortality related concerns. The Antibiotics Use Questionnaire (AUQ) is a theory driven measure based on the Theory of Planned Behaviour (TpB) factors that is designed to investigate drivers of antibiotic use behaviour. The objective of this study is to replicate the factor structure from the pilot study within a similar Australian confirmation cohort, and to extend this through investigating if the factor structure holds in a Chinese-identifying cohort., Methods: The AUQ was disseminated to two cohorts: a confirmation cohort similar to the original study, and a Chinese identifying cohort. Data analysis was completed on the two data sets independently, and on a combined data set. An orthogonal principal components analysis with varimax rotation was used to assess the factor structure, followed by general linear models to determine the influence of the TpB factors on reported antibiotic use., Results: 370 participant responses from the confirmation cohort, and 384 responses from the Chinese-identifying cohort were retained for analysis following review of the data. Results showed modest but acceptable levels of internal reliability across both cohorts. Social norms, and the interaction between attitudes and beliefs and knowledge were significant predictors of self-reported antibiotic use in both cohorts. In the confirmation cohort healthcare training was a significant predictor, and in the Chinese-identifying cohort education was a significant predictor. All other predictors tested produced a nonsignificant relationship with the outcome variable of self-reported antibiotic use., Conclusions: This study successfully replicated the factor structure of the AUQ in a confirmation cohort, as well as a cohort that identified as culturally or legally Chinese, determining that the factor structure is retained when investigated across cultures. The research additionally highlights the need for a measure such as the AUQ, which can identify how differing social, cultural, and community factors can influence what predicts indiscriminate antibiotic use. Future research will be required to determine the full extent to which this tool can be used to guide bespoke community level interventions to assist in the management of antimicrobial resistance., (© 2024. The Author(s).)
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- 2024
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29. REST and RCOR genes display distinct expression profiles in neurons and astrocytes using 2D and 3D human pluripotent stem cell models.
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Maksour S, Ng N, Hulme AJ, Miellet S, Engel M, Muñoz SS, Balez R, Rollo B, Finol-Urdaneta RK, Ooi L, and Dottori M
- Abstract
Repressor element-1 silencing transcription factor (REST) is a transcriptional repressor involved in neurodevelopment and neuroprotection. REST forms a complex with the REST corepressors, CoREST1, CoREST2, or CoREST3 (encoded by RCOR1 , RCOR2 , and RCOR3 , respectively). Emerging evidence suggests that the CoREST family can target unique genes independently of REST, in various neural and glial cell types during different developmental stages. However, there is limited knowledge regarding the expression and function of the CoREST family in human neurodevelopment. To address this gap, we employed 2D and 3D human pluripotent stem cell (hPSC) models to investigate REST and RCOR gene expression levels. Our study revealed a significant increase in RCOR3 expression in glutamatergic cortical and GABAergic ventral forebrain neurons, as well as mature functional NGN2-induced neurons. Additionally, a simplified astrocyte transdifferentiation protocol resulted in a significant decrease in RCOR2 expression following differentiation. REST expression was notably reduced in mature neurons and cerebral organoids. In summary, our findings provide the first insights into the cell-type-specific expression patterns of RCOR genes in human neuronal and glial differentiation. Specifically, RCOR3 expression increases in neurons, while RCOR2 levels decrease in astrocytes. The dynamic expression patterns of REST and RCOR genes during hPSC neuronal and glial differentiation underscore the potential distinct roles played by REST and CoREST proteins in regulating the development of these cell types in humans., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)
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- 2024
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30. Generation of a gene-edited H9 embryonic stem cell line carrying a DOX-inducible NGN2 expression cassette in the CLYBL locus.
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Miellet S, St Clair-Glover M, Maddock M, and Dottori M
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- Humans, Cell Line, Transcription Factors genetics, Transcription Factors metabolism, Embryonic Stem Cells metabolism, Cell Differentiation physiology, Doxycycline pharmacology, Gene Editing
- Abstract
The pro-neural transcription factor neurogenin-2 (NGN2) possesses the ability to rapidly and effectively transform stem cells into fully operational neurons. Here we report the successful generation of a modified H9 human embryonic H9 stem cell line containing a doxycycline (DOX) inducible NGN2 expression construct featuring a floxed Blasticidin/mApple selection module in the safe-harbor locus CLYBL. This cell line retains its pluripotent state in the absence of DOX, yet readily transitions into a neuronal state upon DOX introduction., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mirella Dottori reports financial support was provided by Freidreich’s Ataxia Research Alliance (FARA). Mirella Dottori reports financial support was provided by Friedrich Ataxia Research Association. Mirella Dottori reports financial support was provided by Australian Research Council. Mirella Dottori reports financial support was provided by Medical Research Future Fund Stem Cells Mission. M Dottori has collaborated with Dr Dmitry A. Ovchinnikov, who is an Editor for Stem Cell Research. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
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31. The impact of perceptual complexity on road crossing decisions in younger and older adults.
- Author
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Nicholls VI, Wiener J, Meso AI, and Miellet S
- Subjects
- Humans, Aged, Cognition, Attention, Executive Function, Walking psychology, Accidents, Traffic psychology, Virtual Reality
- Abstract
Cognitive abilities decline with healthy ageing which can have a critical impact on day-to-day activities. One example is road crossing where older adults (OAs) disproportionally fall victim to pedestrian accidents. The current research examined two virtual reality experiments that investigated how the complexity of the road crossing situation impacts OAs (N = 19, ages 65-85) and younger adults (YAs, N = 34, ages 18-24) with a range of executive functioning abilities (EFs). Overall, we found that OAs were able to make safe crossing decisions, and were more cautious than YAs. This continued to be the case in high cognitive load situations. In these situations, safe decisions were associated with an increase in head movements for participants with poorer attention switching than participants with better attention switching suggesting these groups developed compensation strategies to continue to make safe decisions. In situations where participants had less time to make a crossing decision all participants had difficulties making safe crossing decisions which was amplified for OAs and participants with poorer EFs. Our findings suggest more effort should be taken to ensure that road crossing points are clear of visual obstructions and more speed limits should be placed around retirement or care homes, neither of which are legislated for in the UK and Australia., (© 2024. The Author(s).)
- Published
- 2024
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32. Insect nephrocyte function is regulated by a store operated calcium entry mechanism controlling endocytosis and Amnionless turnover.
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Sivakumar S, Miellet S, Clarke C, and Hartley PS
- Subjects
- Animals, Albumins metabolism, Calcium Signaling, Egtazic Acid metabolism, Endocytosis, Larva metabolism, Mammals metabolism, Drosophila melanogaster genetics, Drosophila Proteins metabolism
- Abstract
Insect nephrocytes are ultrafiltration cells that remove circulating proteins and exogenous toxins from the haemolymph. Experimental disruption of nephrocyte development or function leads to systemic impairment of insect physiology as evidenced by cardiomyopathy, chronic activation of immune signalling and shortening of lifespan. The genetic and structural basis of the nephrocyte's ultrafiltration mechanism is conserved between arthropods and mammals, making them an attractive model for studying human renal function and systemic clearance mechanisms in general. Although dynamic changes to intracellular calcium are fundamental to the function of many cell types, there are currently no studies of intracellular calcium signalling in nephrocytes. In this work we aimed to characterise calcium signalling in the pericardial nephrocytes of Drosophila melanogaster. To achieve this, a genetically encoded calcium reporter (GCaMP6) was expressed in nephrocytes to monitor intracellular calcium both in vivo within larvae and in vitro within dissected adults. Larval nephrocytes exhibited stochastically timed calcium waves. A calcium signal could be initiated in preparations of adult nephrocytes and abolished by EGTA, or the store operated calcium entry (SOCE) blocker 2-APB, as well as RNAi mediated knockdown of the SOCE genes Stim and Orai. Neither the presence of calcium-free buffer nor EGTA affected the binding of the endocytic cargo albumin to nephrocytes but they did impair the subsequent accumulation of albumin within nephrocytes. Pre-treatment with EGTA, calcium-free buffer or 2-APB led to significantly reduced albumin binding. Knock-down of Stim and Orai was non-lethal, caused an increase to nephrocyte size and reduced albumin binding, reduced the abundance of the endocytic cargo receptor Amnionless and disrupted the localisation of Dumbfounded at the filtration slit diaphragm. These data indicate that pericardial nephrocytes exhibit stochastically timed calcium waves in vivo and that SOCE mediates the localisation of the endocytic co-receptor Amnionless. Identifying the signals both up and downstream of SOCE may highlight mechanisms relevant to the renal and excretory functions of a broad range of species, including humans., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2022
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33. Exploring the relevance of NUP93 variants in steroid-resistant nephrotic syndrome using next generation sequencing and a fly kidney model.
- Author
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Bierzynska A, Bull K, Miellet S, Dean P, Neal C, Colby E, McCarthy HJ, Hegde S, Sinha MD, Bugarin Diz C, Stirrups K, Megy K, Mapeta R, Penkett C, Marsh S, Forrester N, Afzal M, Stark H, BioResource N, Williams M, Welsh GI, Koziell AB, Hartley PS, and Saleem MA
- Subjects
- Adult, Animals, Child, Disease Models, Animal, Drug Resistance genetics, Glucocorticoids adverse effects, Glucocorticoids therapeutic use, High-Throughput Nucleotide Sequencing, Humans, Mutation, Drosophila melanogaster genetics, Nephrotic Syndrome drug therapy, Nephrotic Syndrome genetics, Nephrotic Syndrome metabolism, Nuclear Pore Complex Proteins genetics, Podocytes metabolism
- Abstract
Background: Variants in genes encoding nuclear pore complex (NPC) proteins are a newly identified cause of paediatric steroid-resistant nephrotic syndrome (SRNS). Recent reports describing NUP93 variants suggest these could be a significant cause of paediatric onset SRNS. We report NUP93 cases in the UK and demonstrate in vivo functional effects of Nup93 depletion in a fly (Drosophila melanogaster) nephrocyte model., Methods: Three hundred thirty-seven paediatric SRNS patients from the National cohort of patients with Nephrotic Syndrome (NephroS) were whole exome and/or whole genome sequenced. Patients were screened for over 70 genes known to be associated with Nephrotic Syndrome (NS). D. melanogaster Nup93 knockdown was achieved by RNA interference using nephrocyte-restricted drivers., Results: Six novel homozygous and compound heterozygous NUP93 variants were detected in 3 sporadic and 2 familial paediatric onset SRNS characterised histologically by focal segmental glomerulosclerosis (FSGS) and progressing to kidney failure by 12 months from clinical diagnosis. Silencing of the two orthologs of human NUP93 expressed in D. melanogaster, Nup93-1, and Nup93-2 resulted in significant signal reduction of up to 82% in adult pericardial nephrocytes with concomitant disruption of NPC protein expression. Additionally, nephrocyte morphology was highly abnormal in Nup93-1 and Nup93-2 silenced flies surviving to adulthood., Conclusion: We expand the spectrum of NUP93 variants detected in paediatric onset SRNS and demonstrate its incidence within a national cohort. Silencing of either D. melanogaster Nup93 ortholog caused a severe nephrocyte phenotype, signaling an important role for the nucleoporin complex in podocyte biology. A higher resolution version of the Graphical abstract is available as Supplementary information., (© 2022. The Author(s).)
- Published
- 2022
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34. Face-Information Sampling in Super-Recognizers.
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Dunn JD, Varela VPL, Nicholls VI, Papinutto M, White D, and Miellet S
- Subjects
- Adult, Humans, Individuality, Facial Recognition
- Abstract
Perceptual processes underlying individual differences in face-recognition ability remain poorly understood. We compared visual sampling of 37 adult super-recognizers-individuals with superior face-recognition ability-with that of 68 typical adult viewers by measuring gaze position as they learned and recognized unfamiliar faces. In both phases, participants viewed faces through "spotlight" apertures that varied in size, with face information restricted in real time around their point of fixation. We found higher accuracy in super-recognizers at all aperture sizes-showing that their superiority does not rely on global sampling of face information but is also evident when they are forced to adopt piecemeal sampling. Additionally, super-recognizers made more fixations, focused less on eye region, and distributed their gaze more than typical viewers. These differences were most apparent when learning faces and were consistent with trends we observed across the broader ability spectrum, suggesting that they are reflective of factors that vary dimensionally in the broader population.
- Published
- 2022
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35. The Relative Contribution of Executive Functions and Aging on Attentional Control During Road Crossing.
- Author
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Nicholls VI, Wiener JM, Meso AI, and Miellet S
- Abstract
As we age, many physical, perceptual and cognitive abilities decline, which can critically impact our day-to-day lives. However, the decline of many abilities is concurrent; thus, it is challenging to disentangle the relative contributions of different abilities in the performance deterioration in realistic tasks, such as road crossing, with age. Research into road crossing has shown that aging and a decline in executive functioning (EFs) is associated with altered information sampling and less safe crossing decisions compared to younger adults. However, in these studies declines in age and EFs were confounded. Therefore, it is impossible to disentangle whether age-related declines in EFs impact on visual sampling and road-crossing performance, or whether visual exploration, and road-crossing performance, are impacted by aging independently of a decline in EFs. In this study, we recruited older adults with maintained EFs to isolate the impacts of aging independently of a decline EFs on road crossing abilities. We recorded eye movements of younger adults and older adults while they watched videos of road traffic and were asked to decide when they could cross the road. Overall, our results show that older adults with maintained EFs sample visual information and make similar road crossing decisions to younger adults. Our findings also reveal that both environmental constraints and EF abilities interact with aging to influence how the road-crossing task is performed. Our findings suggest that older pedestrians' safety, and independence in day-to-day life, can be improved through a limitation of scene complexity and a preservation of EF abilities., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Nicholls, Wiener, Meso and Miellet.)
- Published
- 2022
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36. Making neurons, made easy: The use of Neurogenin-2 in neuronal differentiation.
- Author
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Hulme AJ, Maksour S, St-Clair Glover M, Miellet S, and Dottori M
- Subjects
- Animals, Basic Helix-Loop-Helix Transcription Factors metabolism, Biomarkers, Cell Culture Techniques, Cell Lineage genetics, Cell- and Tissue-Based Therapy, Gene Expression Regulation, High-Throughput Screening Assays, Humans, Nerve Tissue Proteins metabolism, Neural Stem Cells cytology, Neural Stem Cells metabolism, Neurogenesis genetics, Pluripotent Stem Cells cytology, Pluripotent Stem Cells metabolism, Basic Helix-Loop-Helix Transcription Factors genetics, Cell Differentiation genetics, Nerve Tissue Proteins genetics, Neurons cytology, Neurons metabolism
- Abstract
Directed neuronal differentiation of human pluripotent stem cells (hPSCs), neural progenitors, or fibroblasts using transcription factors has allowed for the rapid and highly reproducible differentiation of mature and functional neurons. Exogenous expression of the transcription factor Neurogenin-2 (NGN2) has been widely used to generate different populations of neurons, which have been used in neurodevelopment studies, disease modeling, drug screening, and neuronal replacement therapies. Could NGN2 be a "one-glove-fits-all" approach for neuronal differentiations? This review summarizes the cellular roles of NGN2 and describes the applications and limitations of using NGN2 for the rapid and directed differentiation of neurons., Competing Interests: Conflicts of interest The authors have no financial interests to declare., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2022
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37. The impact of cognitive aging on route learning rate and the acquisition of landmark knowledge.
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Hilton C, Johnson A, Slattery TJ, Miellet S, and Wiener JM
- Subjects
- Aged, Aging, Cognition, Humans, Knowledge, Learning, Cognitive Aging
- Abstract
Aging is accompanied by changes in general cognitive functioning which may impact the learning rate of older adults; however, this is often not controlled for in cognitive aging studies. We investigated the contribution of differences in learning rates to age-related differences in landmark knowledge acquired from route learning. In Experiment 1 we used a standard learning procedure in which participants received a fixed amount of exposure to a route. Consistent with previous research, we found age-related deficits in associative cue and landmark sequence knowledge. Experiment 2 controlled for differences in learning rates by using a flexible exposure learning procedure. Specifically, participants were trained to a performance criterion during route learning before being tested on the content of their route knowledge. While older adults took longer to learn the route than younger adults, the age-related differences in associative cue knowledge were abolished. The deficit in landmark sequence knowledge, however, remained. Experiment 3 replicated these results and introduced a test situation in which a deficit in landmark sequence knowledge yielded an increased likelihood of disorientation in older adults. The findings of this study suggest that age-related deficits in landmark associative cue knowledge are attenuated by controlling for learning rates. In contrast, landmark sequence knowledge deficits persist and are best explained by changes in the learning strategy of older adults to acquire task essential associative cue knowledge at the expense of supplementary sequence knowledge., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
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38. Molecular and Functional Characterization of Neurogenin-2 Induced Human Sensory Neurons.
- Author
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Hulme AJ, McArthur JR, Maksour S, Miellet S, Ooi L, Adams DJ, Finol-Urdaneta RK, and Dottori M
- Abstract
Sensory perception is fundamental to everyday life, yet understanding of human sensory physiology at the molecular level is hindered due to constraints on tissue availability. Emerging strategies to study and characterize peripheral neuropathies in vitro involve the use of human pluripotent stem cells (hPSCs) differentiated into dorsal root ganglion (DRG) sensory neurons. However, neuronal functionality and maturity are limited and underexplored. A recent and promising approach for directing hPSC differentiation towards functionally mature neurons involves the exogenous expression of Neurogenin-2 (NGN2). The optimized protocol described here generates sensory neurons from hPSC-derived neural crest (NC) progenitors through virally induced NGN2 expression. NC cells were derived from hPSCs via a small molecule inhibitor approach and enriched for migrating NC cells (66% SOX10+ cells). At the protein and transcript level, the resulting NGN2 induced sensory neurons (
NGN2 iSNs) express sensory neuron markers such as BRN3A (82% BRN3A+ cells), ISLET1 (91% ISLET1+ cells), TRKA, TRKB, and TRKC. Importantly,NGN2 iSNs repetitively fire action potentials (APs) supported by voltage-gated sodium, potassium, and calcium conductances. In-depth analysis of the molecular basis ofNGN2 iSN excitability revealed functional expression of ion channels associated with the excitability of primary afferent neurons, such as Nav1.7, Nav1.8, Kv1.2, Kv2.1, BK, Cav2.1, Cav2.2, Cav3.2, ASICs and HCN among other ion channels, for which we provide functional and transcriptional evidence. Our characterization of stem cell-derived sensory neurons sheds light on the molecular basis of human sensory physiology and highlights the suitability of using hPSC-derived sensory neurons for modeling human DRG development and their potential in the study of human peripheral neuropathies and drug therapies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Hulme, McArthur, Maksour, Miellet, Ooi, Adams, Finol-Urdaneta and Dottori.)- Published
- 2020
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39. Differences in Encoding Strategy as a Potential Explanation for Age-Related Decline in Place Recognition Ability.
- Author
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Hilton C, Muffato V, Slattery TJ, Miellet S, and Wiener J
- Abstract
The ability to recognise places is known to deteriorate with advancing age. In this study, we investigated the contribution of age-related changes in spatial encoding strategies to declining place recognition ability. We recorded eye movements while younger and older adults completed a place recognition task first described by Muffato et al. (2019). Participants first learned places, which were defined by an array of four objects, and then decided whether the next place they were shown was the same or different to the one they learned. Places could be shown from the same spatial perspective as during learning or from a shifted perspective (30° or 60°). Places that were different to those during learning were changed either by substituting an object in the place with a novel object or by swapping the locations of two objects. We replicated the findings of Muffato et al. (2019) showing that sensitivity to detect changes in a place declined with advancing age and declined when the spatial perspective was shifted. Additionally, older adults were particularly impaired on trials in which object locations were swapped; however, they were not differentially affected by perspective changes compared to younger adults. During place encoding, older adults produced more fixations and saccades, shorter fixation durations, and spent less time looking at objects compared to younger adults. Further, we present an analysis of gaze chaining, designed to capture spatio-temporal aspects of gaze behaviour. The chaining measure was a significant predictor of place recognition performance. We found significant differences between age groups on the chaining measure and argue that these differences in gaze behaviour are indicative of differences in encoding strategy between age groups. In summary, we report a direct replication of Muffato et al. (2019) and provide evidence for age-related differences in spatial encoding strategies, which are related to place recognition performance., (Copyright © 2020 Hilton, Muffato, Slattery, Miellet and Wiener.)
- Published
- 2020
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40. Are age-related deficits in route learning related to control of visual attention?
- Author
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Hilton C, Miellet S, Slattery TJ, and Wiener J
- Subjects
- Aged, Eye Movements physiology, Female, Humans, Male, Reaction Time physiology, Virtual Reality, Young Adult, Aging physiology, Attention physiology, Learning physiology, Spatial Navigation physiology, Visual Perception physiology
- Abstract
Typically aged adults show reduced ability to learn a route compared to younger adults. In this experiment, we investigate the role of visual attention through eye-tracking and engagement of attentional resources in age-related route learning deficits. Participants were shown a route through a realistic virtual environment before being tested on their route knowledge. Younger and older adults were compared on their gaze behaviour during route learning and on their reaction time to a secondary probe task as a measure of attentional engagement. Behavioural results show a performance deficit in route knowledge for older adults compared to younger adults, which is consistent with previous research. We replicated previous findings showing that reaction times to the secondary probe task were longer at decision points than non-decision points, indicating stronger attentional engagement at navigationally relevant locations. However, we found no differences in attentional engagement and no differences for a range of gaze measures between age groups. We conclude that age-related changes in route learning ability are not reflected in changes in control of visual attention or regulation of attentional engagement.
- Published
- 2020
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41. Distribution of Particles in Human Stem Cell-Derived 3D Neuronal Cell Models: Effect of Particle Size, Charge, and Density.
- Author
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Czuba-Wojnilowicz E, Miellet S, Glab A, Viventi S, Cavalieri F, Cortez-Jugo C, Dottori M, and Caruso F
- Subjects
- Humans, Neurons, Particle Size, Silicon Dioxide, Stem Cells, Nanoparticles
- Abstract
Neurodegenerative diseases are generally characterized by a progressive loss of neuronal subpopulations, with no available cure to date. One of the main reasons for the limited clinical outcomes of new drug formulations is the lack of appropriate in vitro human cell models for research and validation. Stem cell technologies provide an opportunity to address this challenge by using patient-derived cells as a platform to test various drug formulations, including particle-based drug carriers. The therapeutic efficacy of drug delivery systems relies on efficient cellular uptake of the carrier and can be dependent on its size, shape, and surface chemistry. Although considerable efforts have been made to understand the effects of the physiochemical properties of particles on two-dimensional cell culture models, little is known of their effect in three-dimensional (3D) cell models of neurodegenerative diseases. Herein, we investigated the role of particle size (235-1000 nm), charge (cationic and anionic), and density (1.05 and 1.8 g cm
-3 ) on the interactions of particles with human embryonic stem cell-derived 3D cell cultures of sensory neurons, called sensory neurospheres (sNSP). Templated layer-by-layer particles, with silica or polystyrene cores, and self-assembled glycogen/DNA polyplexes were used. Particles with sizes <280 nm effectively penetrated sNSP. Additionally, effective plasmid DNA delivery was observed up to 6 days post-transfection with glycogen/DNA polyplexes. The findings provide guidance in nanoparticle design for therapies aimed at neurodegenerative diseases, in particular Friedreich's ataxia, whereby sensory neurons are predominantly affected. They also demonstrate the application of 3D models of human sensory neurons in preclinical drug development.- Published
- 2020
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42. In pursuit of visual attention: SSVEP frequency-tagging moving targets.
- Author
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de Lissa P, Caldara R, Nicholls V, and Miellet S
- Subjects
- Adult, Electroencephalography, Female, Humans, Male, Visual Fields, Young Adult, Attention, Evoked Potentials, Visual, Eye Movements, Visual Perception
- Abstract
Previous research has shown that visual attention does not always exactly follow gaze direction, leading to the concepts of overt and covert attention. However, it is not yet clear how such covert shifts of visual attention to peripheral regions impact the processing of the targets we directly foveate as they move in our visual field. The current study utilised the co-registration of eye-position and EEG recordings while participants tracked moving targets that were embedded with a 30 Hz frequency tag in a Steady State Visually Evoked Potentials (SSVEP) paradigm. When the task required attention to be divided between the moving target (overt attention) and a peripheral region where a second target might appear (covert attention), the SSVEPs elicited by the tracked target at the 30 Hz frequency band were significantly, but transiently, lower than when participants did not have to covertly monitor for a second target. Our findings suggest that neural responses of overt attention are only briefly reduced when attention is divided between covert and overt areas. This neural evidence is in line with theoretical accounts describing attention as a pool of finite resources, such as the perceptual load theory. Altogether, these results have practical implications for many real-world situations where covert shifts of attention may discretely reduce visual processing of objects even when they are directly being tracked with the eyes., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2020
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43. The paradoxical decline and growth of trust as a function of borderline personality disorder trait count: Using discontinuous growth modelling to examine trust dynamics in response to violation and repair.
- Author
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Abramov G, Miellet S, Kautz J, Grenyer BFS, and Deane FP
- Subjects
- Female, Humans, Male, Young Adult, Borderline Personality Disorder psychology, Models, Biological, Trust psychology
- Abstract
Borderline personality disorder (BPD) is associated with paradoxical trust cognitions and behaviours. While BPD is associated with difficulty forming trust and maintaining cooperation in trust-based exchanges, design and analytical methodology best suited to reveal the temporal ebb and flow of trust have been underutilized. We used an economic game to examine the trajectories of trust as it forms, dissolves, and restores in response to trust violation and repair, and to explain how these vary as a function of borderline pathology. Young adults (N = 234) played a 15-round trust game in which partner trustworthiness was varied to create three phases: trust formation, trust violation, and trust restoration. Discontinuous growth modelling was employed to capture the trends in trust over time and their relationship with BPD trait count. BPD trait count was associated with an incongruous pattern of trust behaviour in the form of declining trust when interacting with a new and cooperative partner, and paradoxically, increasing trust following multiple instances of trust violation by that partner. BPD trait count was also associated with trust restoring at a faster rate than it was originally formed. By adopting a methodology that recognizes the dynamic nature of trust, this study illustrated at a micro level how relational disturbances may be produced and maintained in those with a moderate to high BPD trait count. Further investigation of the factors and processes that underlie these incongruous trust dynamics is recommended., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2020
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44. The drivers of antibiotic use and misuse: the development and investigation of a theory driven community measure.
- Author
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Byrne MK, Miellet S, McGlinn A, Fish J, Meedya S, Reynolds N, and van Oijen AM
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cross-Sectional Studies, Drug Resistance, Bacterial, Family, Female, Health Personnel, Humans, Male, Middle Aged, Psychometrics, Public Health, Reproducibility of Results, Social Norms, Young Adult, Anti-Bacterial Agents therapeutic use, Drug Misuse, Health Behavior, Health Knowledge, Attitudes, Practice, Surveys and Questionnaires
- Abstract
Background: Antimicrobial resistance is a global public health concern, with extensive associated health and economic implications. Actions to slow and contain the development of resistance are imperative. Despite the fact that overuse and misuse of antibiotics are highlighted as major contributing factors to this resistance, no sufficiently validated measures aiming to investigate the drivers behind consumer behaviour amongst the general population are available. The objective of this study was to develop and investigate the psychometric properties of an original, novel and multiple-item questionnaire, informed by the Theory of Planned Behaviour, to measure factors contributing to self-reported antibiotic use within the community., Method: A three-phase process was employed, including literature review and item generation; expert panel review; and pre-test. Investigation of the questionnaire was subsequently conducted through a cross-sectional, anonymous survey. Orthogonal principal analysis with varimax rotation, cronbach alpha and linear mixed-effects modelling analyses were conducted. A 60 item questionnaire was produced encompassing demographics, social desirability, three constructs of the Theory of Planned Behaviour including: attitudes and beliefs; subjective norm; perceived behavioural control; behaviour; and a covariate - knowledge., Results: Three hundred seventy-three participants completed the survey. Eighty participants (21%) were excluded due to social desirability concerns, with data from the remaining 293 participants analysed. Results showed modest but acceptable levels of internal reliability, with high inter-item correlations within each construct. All four variables and the outcome variable of antibiotic use behaviour comprised four items with the exception of social norms, for which there were two items, producing a final 18 item questionnaire. Perceived behavioural control, social norms, the interaction between attitudes and beliefs and knowledge, and the presence of a healthcare worker in the family were all significant predictors of antibiotic use behaviour. All other predictors tested produced a nonsignificant relationship with the outcome variable of self-reported antibiotic use., Conclusion: This study successfully developed and validated a novel tool which assesses factors influencing community antibiotic use and misuse. The questionnaire can be used to guide appropriate intervention strategies to reduce antibiotic misuse in the general population. Future research is required to assess the extent to which this tool can guide community-based intervention strategies.
- Published
- 2019
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45. Multilevel regulation of the glass locus during Drosophila eye development.
- Author
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Fritsch C, Bernardo-Garcia FJ, Humberg TH, Mishra AK, Miellet S, Almeida S, Frochaux MV, Deplancke B, Huber A, and Sprecher SG
- Subjects
- Alternative Splicing, Animals, Cell Differentiation, Drosophila melanogaster genetics, Drosophila melanogaster growth & development, Drosophila melanogaster metabolism, Enhancer Elements, Genetic, Eye metabolism, Gene Expression Regulation, Developmental, Mutagenesis, Site-Directed, Photoreceptor Cells metabolism, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Drosophila Proteins genetics, Drosophila Proteins metabolism, Eye growth & development
- Abstract
Development of eye tissue is initiated by a conserved set of transcription factors termed retinal determination network (RDN). In the fruit fly Drosophila melanogaster, the zinc-finger transcription factor Glass acts directly downstream of the RDN to control identity of photoreceptor as well as non-photoreceptor cells. Tight control of spatial and temporal gene expression is a critical feature during development, cell-fate determination as well as maintenance of differentiated tissues. The molecular mechanisms that control expression of glass, however, remain largely unknown. We here identify complex regulatory mechanisms controlling expression of the glass locus. All information to recapitulate glass expression are contained in a compact 5.2 kb cis-acting genomic element by combining different cell-type specific and general enhancers with repressor elements. Moreover, the immature RNA of the locus contains an alternative small open reading frame (smORF) upstream of the actual glass translation start, resulting in a small peptide instead of the three possible Glass protein isoforms. CRISPR/Cas9-based mutagenesis shows that the smORF is not required for the formation of functioning photoreceptors, but is able to attenuate effects of glass misexpression. Furthermore, editing the genome to generate glass loci eliminating either one or two isoforms shows that only one of the three proteins is critical for formation of functioning photoreceptors, while removing the two other isoforms did not cause defects in developmental or photoreceptor function. Our results show that eye development and function is largely unaffected by targeted manipulations of critical features of the glass transcript, suggesting a strong selection pressure to allow the formation of a functioning eye., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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46. Developing attentional control in naturalistic dynamic road crossing situations.
- Author
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Nicholls VI, Jean-Charles G, Lao J, de Lissa P, Caldara R, and Miellet S
- Subjects
- Adolescent, Adult, Algorithms, Child, Child, Preschool, Decision Making, Eye Movements physiology, Fixation, Ocular physiology, Humans, Photic Stimulation, Young Adult, Attention physiology, Pedestrians
- Abstract
In the last 20 years, there has been increasing interest in studying visual attentional processes under more natural conditions. In the present study, we propose to determine the critical age at which children show similar to adult performance and attentional control in a visually guided task; in a naturalistic dynamic and socially relevant context: road crossing. We monitored visual exploration and crossing decisions in adults and children aged between 5 and 15 while they watched road traffic videos containing a range of traffic densities with or without pedestrians. 5-10 year old (y/o) children showed less systematic gaze patterns. More specifically, adults and 11-15 y/o children look mainly at the vehicles' appearing point, which is an optimal location to sample diagnostic information for the task. In contrast, 5-10 y/os look more at socially relevant stimuli and attend to moving vehicles further down the trajectory when the traffic density is high. Critically, 5-10 y/o children also make an increased number of crossing decisions compared to 11-15 y/os and adults. Our findings reveal a critical shift around 10 y/o in attentional control and crossing decisions in a road crossing task.
- Published
- 2019
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47. The impact of SPARC on age-related cardiac dysfunction and fibrosis in Drosophila.
- Author
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Vaughan L, Marley R, Miellet S, and Hartley PS
- Subjects
- Animals, Collagen metabolism, Drosophila melanogaster, Fibrosis, Humans, Aging, Heart Failure etiology, Myocardium pathology, Osteonectin physiology
- Abstract
Tissue fibrosis, an accumulation of extracellular matrix proteins such as collagen, accompanies cardiac ageing in humans and this is linked to an increased risk of cardiac failure. The mechanisms driving age-related tissue fibrosis and cardiac dysfunction are unclear, yet clinically important. Drosophila is amenable to the study of cardiac ageing as well as collagen deposition; however it is unclear whether collagen accumulates in the ageing Drosophila heart. This work examined collagen deposition and cardiac function in ageing Drosophila, in the context of reduced expression of collagen-interacting protein SPARC (Secreted Protein Acidic and Rich in Cysteine) an evolutionarily conserved protein linked with fibrosis. Heart function was measured using high frame rate videomicroscopy. Collagen deposition was monitored using a fluorescently-tagged collagen IV reporter (encoded by the Viking gene) and staining of the cardiac collagen, Pericardin. The Drosophila heart accumulated collagen IV and Pericardin as flies aged. Associated with this was a decline in cardiac function. SPARC heterozygous flies lived longer than controls and showed little to no age-related cardiac dysfunction. As flies of both genotypes aged, cardiac levels of collagen IV (Viking) and Pericardin increased similarly. Over-expression of SPARC caused cardiomyopathy and increased Pericardin deposition. The findings demonstrate that, like humans, the Drosophila heart develops a fibrosis-like phenotype as it ages. Although having no gross impact on collagen accumulation, reduced SPARC expression extended Drosophila lifespan and cardiac health span. It is proposed that cardiac fibrosis in humans may develop due to the activation of conserved mechanisms and that SPARC may mediate cardiac ageing by mechanisms more subtle than gross accumulation of collagen., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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48. The Facespan-the perceptual span for face recognition.
- Author
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Papinutto M, Lao J, Ramon M, Caldara R, and Miellet S
- Subjects
- Female, Humans, Male, Psychomotor Performance physiology, Reaction Time, Saccades physiology, Young Adult, Face physiology, Facial Recognition physiology, Fixation, Ocular physiology, Visual Perception physiology
- Abstract
In reading, the perceptual span is a well-established concept that refers to the amount of information that can be read in a single fixation. Surprisingly, despite extensive empirical interest in determining the perceptual strategies deployed to process faces and an ongoing debate regarding the factors or mechanism(s) underlying efficient face processing, the perceptual span for faces-the Facespan-remains undetermined. To address this issue, we applied the gaze-contingent Spotlight technique implemented in an old-new face recognition paradigm. This procedure allowed us to parametrically vary the amount of facial information available at a fixated location in order to determine the minimal aperture size at which face recognition performance plateaus. As expected, accuracy increased nonlinearly with spotlight size apertures. Analyses of Structural Similarity comparing the available information during spotlight and natural viewing conditions indicate that the Facespan-the minimum spatial extent of preserved facial information leading to comparable performance as in natural viewing-encompasses 7° of visual angle in our viewing conditions (size of the face stimulus: 15.6°; viewing distance: 70 cm), which represents 45% of the face. The present findings provide a benchmark for future investigations that will address if and how the Facespan is modulated by factors such as cultural, developmental, idiosyncratic, or task-related differences.
- Published
- 2017
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49. iMap4: An open source toolbox for the statistical fixation mapping of eye movement data with linear mixed modeling.
- Author
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Lao J, Miellet S, Pernet C, Sokhn N, and Caldara R
- Subjects
- Humans, Monte Carlo Method, Statistics, Nonparametric, User-Computer Interface, Biometry methods, Eye Movements physiology, Linear Models, Software
- Abstract
A major challenge in modern eye movement research is to statistically map where observers are looking, by isolating the significant differences between groups and conditions. As compared to the signals from contemporary neuroscience measures, such as magneto/electroencephalography and functional magnetic resonance imaging, eye movement data are sparser, with much larger variations in space across trials and participants. As a result, the implementation of a conventional linear modeling approach on two-dimensional fixation distributions often returns unstable estimations and underpowered results, leaving this statistical problem unresolved (Liversedge, Gilchrist, & Everling, 2011). Here, we present a new version of the iMap toolbox (Caldara & Miellet, 2011) that tackles this issue by implementing a statistical framework comparable to those developed in state-of-the-art neuroimaging data-processing toolboxes. iMap4 uses univariate, pixel-wise linear mixed models on smoothed fixation data, with the flexibility of coding for multiple between- and within-subjects comparisons and performing all possible linear contrasts for the fixed effects (main effects, interactions, etc.). Importantly, we also introduced novel nonparametric tests based on resampling, to assess statistical significance. Finally, we validated this approach by using both experimental and Monte Carlo simulation data. iMap4 is a freely available MATLAB open source toolbox for the statistical fixation mapping of eye movement data, with a user-friendly interface providing straightforward, easy-to-interpret statistical graphical outputs. iMap4 matches the standards of robust statistical neuroimaging methods and represents an important step in the data-driven processing of eye movement fixation data, an important field of vision sciences.
- Published
- 2017
- Full Text
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50. Super-Memorizers Are Not Super-Recognizers.
- Author
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Ramon M, Miellet S, Dzieciol AM, Konrad BN, Dresler M, and Caldara R
- Subjects
- Adult, Eye Movements, Female, Humans, Male, Young Adult, Face, Memory, Visual Perception
- Abstract
Humans have a natural expertise in recognizing faces. However, the nature of the interaction between this critical visual biological skill and memory is yet unclear. Here, we had the unique opportunity to test two individuals who have had exceptional success in the World Memory Championships, including several world records in face-name association memory. We designed a range of face processing tasks to determine whether superior/expert face memory skills are associated with distinctive perceptual strategies for processing faces. Superior memorizers excelled at tasks involving associative face-name learning. Nevertheless, they were as impaired as controls in tasks probing the efficiency of the face system: face inversion and the other-race effect. Super memorizers did not show increased hippocampal volumes, and exhibited optimal generic eye movement strategies when they performed complex multi-item face-name associations. Our data show that the visual computations of the face system are not malleable and are robust to acquired expertise involving extensive training of associative memory.
- Published
- 2016
- Full Text
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