The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform

Stuart L Graham - One of the best experts on this subject based on the ideXlab platform.

  • improving reproducibility of vep recording in rats electrodes Stimulus Source and peak analysis
    Documenta Ophthalmologica, 2011
    Co-Authors: Yuyi You, Johnson Thie, Stuart L Graham, Alexander Klistorner
    Abstract:

    The aims of this study were to evaluate and improve the reproducibility of visual evoked potential (VEP) measurement in rats and to develop a mini-Ganzfeld stimulator for rat VEP recording. VEPs of Sprague–Dawley rats were recorded on one randomly selected eye on three separate days within a week, and the recordings were repeated three times on the first day to evaluate the intrasession repeatability and intersession reproducibility. The VEPs were recorded with subdermal needle and implanted skull screw electrodes, respectively, to evaluate the effect of electrode configuration on VEP reproducibility. We also designed a mini-Ganzfeld stimulator for rats, which provided better eye isolation than the conventional visual stimuli such as flash strobes and large Ganzfeld systems. The VEP responses from mini-Ganzfeld were compared with PS33-PLUS photic strobe and single light-emitting diode (LED). The latencies of P1, N1, P2, N2, and P3 and the amplitude of each component were measured and analysed. Intrasession and intersession within-subject standard deviations (Sw), coefficient of variation, repeatability (R95) and intraclass correlation coefficient (ICC) were calculated. The VEPs recorded using the implanted skull electrodes showed significantly larger amplitude and higher reproducibility compared to the needle electrodes (P < 0.05). The mini-Ganzfeld stimulator showed superior repeatability and reproducibility in VEP recording. The intra/intersession ICCs of latency were 0.85/0.70 for mini-Ganzfeld, 0.72/0.62 for PS33-PLUS and only 0.59/0.42 for single LED. The latencies of the early peaks (N1 and P2) demonstrated better reproducibility than the later waves. The mean intrasession and intersession ICCs were 0.96 and 0.86 for the early peaks. Using a combination of skull screw electrodes, mini-Ganzfeld stimulator and early peak analysis, we achieved a high reproducibility in the rat VEP measurement. The latencies of the early peaks of rat VEPs were more consistent, which may be due to their generation in the primary visual cortex via the retino-geniculate fibres.

  • Improving reproducibility of VEP recording in rats: Electrodes, Stimulus Source and peak analysis
    Documenta Ophthalmologica, 2011
    Co-Authors: Yuyi You, Johnson Thie, Alexander Klistorner, Stuart L Graham
    Abstract:

    The aims of this study were to evaluate and improve the reproducibility of visual evoked potential (VEP) measurement in rats and to develop a mini-Ganzfeld stimulator for rat VEP recording. VEPs of Sprague-Dawley rats were recorded on one randomly selected eye on three separate days within a week, and the recordings were repeated three times on the first day to evaluate the intrasession repeatability and intersession reproducibility. The VEPs were recorded with subdermal needle and implanted skull screw electrodes, respectively, to evaluate the effect of electrode configuration on VEP reproducibility. We also designed a mini-Ganzfeld stimulator for rats, which provided better eye isolation than the conventional visual stimuli such as flash strobes and large Ganzfeld systems. The VEP responses from mini-Ganzfeld were compared with PS33-PLUS photic strobe and single light-emitting diode (LED). The latencies of P1, N1, P2, N2, and P3 and the amplitude of each component were measured and analysed. Intrasession and intersession within-subject standard deviations (Sw), coefficient of variation, repeatability (R95) and intraclass correlation coefficient (ICC) were calculated. The VEPs recorded using the implanted skull electrodes showed significantly larger amplitude and higher reproducibility compared to the needle electrodes (P

Jérôme Casas - One of the best experts on this subject based on the ideXlab platform.

  • Relative roles of reSource Stimulus and vegetation architecture on the paths of flies foraging for fruit
    Oikos, 2014
    Co-Authors: Oriol Verdeny-vilalta, Martín Aluja, Jérôme Casas
    Abstract:

    Many animals use their perceptual abilities to orient and locate reSources in architecturally complex environments. However, it is not well known how the strength of a Stimulus Source affects the geometry of animal movement in architecturally complex environments. We mapped the 3D vegetation architecture of four apple trees of varying morphology and age and recorded the paths of apple maggot flies Rhagoletis pomonella foraging for artificial fruit. We compared the observed movement with the one obtained from a random walk model on a graph to estimate both 1) the attraction radius and strength of a fruit and 2) the relative roles of the architecture of vegetation and of the strength of attraction of a fruit on the movement of flies. The attraction radius is the maximal distance at which a Stimulus Source biases the movement of individuals and the attraction strength measures how strong this bias is. Plant architectural complexity is defined according to both foliage density and its 3D distribution within the canopy. A single fruit induces a bias in the path orientation of an insect that is at a large distance, relative to a tree volume, but it has no effect on the step length of moves. The plant complexity makes a minor contribution to defining the radius of the sphere of attraction, but a large contribution to the attraction strength. Conditional on visiting the location, the plant architecture plays a minor role compared to that of the presence of the fruit. Our findings show that the complexity of the environment can alter the use of sensory information, which has important implications for animal movements in complex environments. The importance of our results in animal dispersal and foraging is considered.

  • Orientation towards prey in antlions: efficient use of wave propagation in sand.
    Journal of Experimental Biology, 2007
    Co-Authors: Arnold Fertin, Jérôme Casas
    Abstract:

    SUMMARY Substrate-borne vibration for locating mates, predators and prey is widespread in the animal kingdown. Antlion larvae dig funnel-shaped traps to catch ants and they are totally immersed in dry sand. We used a playback setup reproducing an ant walking on sand to clearly demonstrate that antlions use sand-borne vibrations to locate their prey. Half the tested animals moved towards the Stimulus Source. The shoot angle of sand tossing was very close to the target angle, indicating excellent ability to perceive Stimulus direction. We also discuss orientation mechanisms in sand, a medium with highly unusual wave propagation properties.

René J. Wubbels - One of the best experts on this subject based on the ideXlab platform.

Alexander Klistorner - One of the best experts on this subject based on the ideXlab platform.

  • improving reproducibility of vep recording in rats electrodes Stimulus Source and peak analysis
    Documenta Ophthalmologica, 2011
    Co-Authors: Yuyi You, Johnson Thie, Stuart L Graham, Alexander Klistorner
    Abstract:

    The aims of this study were to evaluate and improve the reproducibility of visual evoked potential (VEP) measurement in rats and to develop a mini-Ganzfeld stimulator for rat VEP recording. VEPs of Sprague–Dawley rats were recorded on one randomly selected eye on three separate days within a week, and the recordings were repeated three times on the first day to evaluate the intrasession repeatability and intersession reproducibility. The VEPs were recorded with subdermal needle and implanted skull screw electrodes, respectively, to evaluate the effect of electrode configuration on VEP reproducibility. We also designed a mini-Ganzfeld stimulator for rats, which provided better eye isolation than the conventional visual stimuli such as flash strobes and large Ganzfeld systems. The VEP responses from mini-Ganzfeld were compared with PS33-PLUS photic strobe and single light-emitting diode (LED). The latencies of P1, N1, P2, N2, and P3 and the amplitude of each component were measured and analysed. Intrasession and intersession within-subject standard deviations (Sw), coefficient of variation, repeatability (R95) and intraclass correlation coefficient (ICC) were calculated. The VEPs recorded using the implanted skull electrodes showed significantly larger amplitude and higher reproducibility compared to the needle electrodes (P < 0.05). The mini-Ganzfeld stimulator showed superior repeatability and reproducibility in VEP recording. The intra/intersession ICCs of latency were 0.85/0.70 for mini-Ganzfeld, 0.72/0.62 for PS33-PLUS and only 0.59/0.42 for single LED. The latencies of the early peaks (N1 and P2) demonstrated better reproducibility than the later waves. The mean intrasession and intersession ICCs were 0.96 and 0.86 for the early peaks. Using a combination of skull screw electrodes, mini-Ganzfeld stimulator and early peak analysis, we achieved a high reproducibility in the rat VEP measurement. The latencies of the early peaks of rat VEPs were more consistent, which may be due to their generation in the primary visual cortex via the retino-geniculate fibres.

  • Improving reproducibility of VEP recording in rats: Electrodes, Stimulus Source and peak analysis
    Documenta Ophthalmologica, 2011
    Co-Authors: Yuyi You, Johnson Thie, Alexander Klistorner, Stuart L Graham
    Abstract:

    The aims of this study were to evaluate and improve the reproducibility of visual evoked potential (VEP) measurement in rats and to develop a mini-Ganzfeld stimulator for rat VEP recording. VEPs of Sprague-Dawley rats were recorded on one randomly selected eye on three separate days within a week, and the recordings were repeated three times on the first day to evaluate the intrasession repeatability and intersession reproducibility. The VEPs were recorded with subdermal needle and implanted skull screw electrodes, respectively, to evaluate the effect of electrode configuration on VEP reproducibility. We also designed a mini-Ganzfeld stimulator for rats, which provided better eye isolation than the conventional visual stimuli such as flash strobes and large Ganzfeld systems. The VEP responses from mini-Ganzfeld were compared with PS33-PLUS photic strobe and single light-emitting diode (LED). The latencies of P1, N1, P2, N2, and P3 and the amplitude of each component were measured and analysed. Intrasession and intersession within-subject standard deviations (Sw), coefficient of variation, repeatability (R95) and intraclass correlation coefficient (ICC) were calculated. The VEPs recorded using the implanted skull electrodes showed significantly larger amplitude and higher reproducibility compared to the needle electrodes (P

Yuyi You - One of the best experts on this subject based on the ideXlab platform.

  • improving reproducibility of vep recording in rats electrodes Stimulus Source and peak analysis
    Documenta Ophthalmologica, 2011
    Co-Authors: Yuyi You, Johnson Thie, Stuart L Graham, Alexander Klistorner
    Abstract:

    The aims of this study were to evaluate and improve the reproducibility of visual evoked potential (VEP) measurement in rats and to develop a mini-Ganzfeld stimulator for rat VEP recording. VEPs of Sprague–Dawley rats were recorded on one randomly selected eye on three separate days within a week, and the recordings were repeated three times on the first day to evaluate the intrasession repeatability and intersession reproducibility. The VEPs were recorded with subdermal needle and implanted skull screw electrodes, respectively, to evaluate the effect of electrode configuration on VEP reproducibility. We also designed a mini-Ganzfeld stimulator for rats, which provided better eye isolation than the conventional visual stimuli such as flash strobes and large Ganzfeld systems. The VEP responses from mini-Ganzfeld were compared with PS33-PLUS photic strobe and single light-emitting diode (LED). The latencies of P1, N1, P2, N2, and P3 and the amplitude of each component were measured and analysed. Intrasession and intersession within-subject standard deviations (Sw), coefficient of variation, repeatability (R95) and intraclass correlation coefficient (ICC) were calculated. The VEPs recorded using the implanted skull electrodes showed significantly larger amplitude and higher reproducibility compared to the needle electrodes (P < 0.05). The mini-Ganzfeld stimulator showed superior repeatability and reproducibility in VEP recording. The intra/intersession ICCs of latency were 0.85/0.70 for mini-Ganzfeld, 0.72/0.62 for PS33-PLUS and only 0.59/0.42 for single LED. The latencies of the early peaks (N1 and P2) demonstrated better reproducibility than the later waves. The mean intrasession and intersession ICCs were 0.96 and 0.86 for the early peaks. Using a combination of skull screw electrodes, mini-Ganzfeld stimulator and early peak analysis, we achieved a high reproducibility in the rat VEP measurement. The latencies of the early peaks of rat VEPs were more consistent, which may be due to their generation in the primary visual cortex via the retino-geniculate fibres.

  • Improving reproducibility of VEP recording in rats: Electrodes, Stimulus Source and peak analysis
    Documenta Ophthalmologica, 2011
    Co-Authors: Yuyi You, Johnson Thie, Alexander Klistorner, Stuart L Graham
    Abstract:

    The aims of this study were to evaluate and improve the reproducibility of visual evoked potential (VEP) measurement in rats and to develop a mini-Ganzfeld stimulator for rat VEP recording. VEPs of Sprague-Dawley rats were recorded on one randomly selected eye on three separate days within a week, and the recordings were repeated three times on the first day to evaluate the intrasession repeatability and intersession reproducibility. The VEPs were recorded with subdermal needle and implanted skull screw electrodes, respectively, to evaluate the effect of electrode configuration on VEP reproducibility. We also designed a mini-Ganzfeld stimulator for rats, which provided better eye isolation than the conventional visual stimuli such as flash strobes and large Ganzfeld systems. The VEP responses from mini-Ganzfeld were compared with PS33-PLUS photic strobe and single light-emitting diode (LED). The latencies of P1, N1, P2, N2, and P3 and the amplitude of each component were measured and analysed. Intrasession and intersession within-subject standard deviations (Sw), coefficient of variation, repeatability (R95) and intraclass correlation coefficient (ICC) were calculated. The VEPs recorded using the implanted skull electrodes showed significantly larger amplitude and higher reproducibility compared to the needle electrodes (P