The Experts below are selected from a list of 56952 Experts worldwide ranked by ideXlab platform
Trevor J Wardill - One of the best experts on this subject based on the ideXlab platform.
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a novel setup for simultaneous two photon functional imaging and precise spectral and spatial Visual Stimulation in drosophila
Scientific Reports, 2020Co-Authors: Rachael C Feord, Trevor J WardillAbstract:Motion vision has been extensively characterised in Drosophila melanogaster, but substantially less is known about how flies process colour, or how spectral information affects other Visual modalities. To accurately dissect the components of the early Visual system responsible for processing colour, we developed a versatile Visual Stimulation setup to probe combined spatial, temporal and spectral response properties. Using flies expressing neural activity indicators, we tracked Visual responses in the medulla, the second Visual neuropil, to a projected colour stimulus. The introduction of custom bandpass optical filters enables simultaneous two-photon imaging and Visual Stimulation over a large range of wavelengths without compromising the temporal Stimulation rate. With monochromator-produced light, any spectral bandwidth and centre wavelength from 390 to 730 nm can be selected to produce a narrow spectral hue. A specialised screen material scatters each band of light across the visible spectrum equally at all locations of the screen, thus enabling presentation of spatially structured stimuli. We show layer-specific shifts of spectral response properties in the medulla correlating with projection regions of photoreceptor terminals.
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a novel setup for simultaneous two photon functional imaging and precise spectral and spatial Visual Stimulation in drosophila
bioRxiv, 2020Co-Authors: Rachael C Feord, Trevor J WardillAbstract:Motion vision has been extensively characterized in Drosophila melanogaster, but substantially less is known about how flies process colour, or how spectral information affects other Visual modalities. To accurately dissect the components of the early Visual system responsible for processing colour, we developed a versatile Visual Stimulation setup to probe combined spatial, temporal and spectral response properties. Using flies expressing neural activity indicators, we tracked Visual responses in the medulla to a projected colour stimulus (i.e. narrow bands of light). The introduction of custom Semrock bandpass optical filters enables simultaneous two-photon imaging and Visual Stimulation over a large range of wavelengths. A specialized screen material scatters each band of light across the spectrum equally at all locations of the screen, thus enabling presentation of spatially structured stimuli. We show layer-specific shifts of spectral response properties in the medulla correlating with projection regions of photoreceptor terminals.
Kamil Ugurbil - One of the best experts on this subject based on the ideXlab platform.
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mapping of lateral geniculate nucleus activation during Visual Stimulation in human brain using fmri
Magnetic Resonance in Medicine, 1998Co-Authors: Wei Chen, S Ogawa, Toshinori Kato, John Strupp, Kamil UgurbilAbstract:Functional magnetic resonance imaging has been successfully used to map the activation in the lateral geniculate nucleus (LGN) in both hemispheres as well as the primary Visual cortex (V1) during a checkerboard Visual Stimulation. The average blood oxygenation level dependent (BOLD) change in LGN was less than that in V1. However, the BOLD temporal responses were similar between LGN and V1. The activation in the pulvinar nucleus during Visual perception was also detected, and its activated location could be separated from LGN in 3D images. The LGN activation between intersubject and intrasubject multiple trials was compared. The results demonstrate that fMRI can reliably and robustly detect small subcortical nucleus activation in the human brain.
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functional brain mapping using magnetic resonance imaging signal changes accompanying Visual Stimulation
Investigative Radiology, 1992Co-Authors: Ravi S Menon, S Ogawa, Seonggi Kim, Jutta M Ellermann, Hellmut Merkle, David W Tank, Kamil UgurbilAbstract:Menon RS, Ogawa S, Kim S-G, Ellermann JM, Merkle H, Tank DW, Ugurbil K. Functional brain mapping using magnetic resonance imaging: signal changes accompanying Visual Stimulation. Invest Radiol 1992;27:S47-S53.Easily detectable (5%-20%) transient increases in the intensity of water proton magnetic re
Rachael C Feord - One of the best experts on this subject based on the ideXlab platform.
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a novel setup for simultaneous two photon functional imaging and precise spectral and spatial Visual Stimulation in drosophila
Scientific Reports, 2020Co-Authors: Rachael C Feord, Trevor J WardillAbstract:Motion vision has been extensively characterised in Drosophila melanogaster, but substantially less is known about how flies process colour, or how spectral information affects other Visual modalities. To accurately dissect the components of the early Visual system responsible for processing colour, we developed a versatile Visual Stimulation setup to probe combined spatial, temporal and spectral response properties. Using flies expressing neural activity indicators, we tracked Visual responses in the medulla, the second Visual neuropil, to a projected colour stimulus. The introduction of custom bandpass optical filters enables simultaneous two-photon imaging and Visual Stimulation over a large range of wavelengths without compromising the temporal Stimulation rate. With monochromator-produced light, any spectral bandwidth and centre wavelength from 390 to 730 nm can be selected to produce a narrow spectral hue. A specialised screen material scatters each band of light across the visible spectrum equally at all locations of the screen, thus enabling presentation of spatially structured stimuli. We show layer-specific shifts of spectral response properties in the medulla correlating with projection regions of photoreceptor terminals.
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a novel setup for simultaneous two photon functional imaging and precise spectral and spatial Visual Stimulation in drosophila
bioRxiv, 2020Co-Authors: Rachael C Feord, Trevor J WardillAbstract:Motion vision has been extensively characterized in Drosophila melanogaster, but substantially less is known about how flies process colour, or how spectral information affects other Visual modalities. To accurately dissect the components of the early Visual system responsible for processing colour, we developed a versatile Visual Stimulation setup to probe combined spatial, temporal and spectral response properties. Using flies expressing neural activity indicators, we tracked Visual responses in the medulla to a projected colour stimulus (i.e. narrow bands of light). The introduction of custom Semrock bandpass optical filters enables simultaneous two-photon imaging and Visual Stimulation over a large range of wavelengths. A specialized screen material scatters each band of light across the spectrum equally at all locations of the screen, thus enabling presentation of spatially structured stimuli. We show layer-specific shifts of spectral response properties in the medulla correlating with projection regions of photoreceptor terminals.
Sylvain Baillet - One of the best experts on this subject based on the ideXlab platform.
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Phase delays within Visual cortex shape the response to steady-state Visual Stimulation.
NeuroImage, 2010Co-Authors: Benoit Cottereau, Jean Lorenceau, Alexandre Gramfort, Bertrand Thirion, Maureen Clerc, Sylvain BailletAbstract:Although the spatial organization of Visual areas can be revealed by functional Magnetic Resonance Imaging (fMRI), the synoptic, non-invasive access to the temporal characteristics of the information flow amongst distributed Visual processes remains a technical and methodological challenge. Using frequency-encoded steady-state Visual Stimulation together with a combination of time-resolved functional magnetic source imaging from magnetoencephalography (MEG) and anatomical magnetic resonance imaging (MRI), this study evidences maps of visuotopic sustained oscillatory neural responses distributed across the Visual cortex. Our results further reveal relative phase delays across responding striate and extra-striate Visual areas, which thereby shape the chronometry of neural processes amongst these regions. The methodology developed in this study points at further developments in time-resolved analyses of distributed Visual processes in the millisecond range, and to new ways of exploring the dynamics of functional processes within the human Visual cortex non-invasively.
Henk Spekreijse - One of the best experts on this subject based on the ideXlab platform.
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Visual Stimulation reduces EEG activity in man.
Brain research, 1991Co-Authors: Peter C. M. Vijn, Bob W. Van Dijk, Henk SpekreijseAbstract:Abstract Data are presented which show that background electric activity of the human brain is reduced by Visual Stimulation. Occipital EEG amplitude decreases 5–15% for all frequencies analyzed (0.2–40 Hz) upon pattern Stimulation. The reduction is stimulus-specific, i.e. is the strongest for stimuli that activate a large number of Visual cortical neurons.
