PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 10092031

Simple and powerful visual stimulus generator.

J Kremlácek·M Kuba·Z Kubová·F Vít
View original source ↗Export metadata ↓

Abstract

We describe a cheap, simple, portable and efficient approach to visual stimulation for neurophysiology which does not need any special hardware equipment. The method based on an animation technique uses the FLI autodesk animator format. This form of the animation is replayed by a special program ('player') providing synchronisation pulses toward recording system via parallel port. The 'player is running on an IBM compatible personal computer under MS-DOS operation system and stimulus is displayed on a VGA computer monitor. Various stimuli created with this technique for visual evoked potentials (VEPs) are presented.

Explore related subjects

ColorComputer GraphicsDiagnosis, Computer-AssistedEvoked Potentials, VisualHumansMicrocomputersPhotic StimulationReproducibility of ResultsSoftware ValidationJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J Kremlácek, M Kuba, Z Kubová, F Vít. 1999. Simple and powerful visual stimulus generator.. https://doi.org/10.1016/s0169-2607(98)00074-1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2001

Negative frequency-dependent selection maintains a dramatic flower color polymorphism in the rewardless orchid Dactylorhiza sambucina (L.) Soo.

The orchid Dactylorhiza sambucina shows a stable and dramatic flower-color polymorphism, with both yellow- and purple-flowered individuals present in natural populations throughout the range of the species in Europe. The evolutionary significance of flower-color polymorphisms found in many rewardless orchid species has been discussed at length, but the mechanisms responsible for their maintenance remain unclear. Laboratory experiments have suggested that behavioral responses by pollinators to lack of reward availability might result in a reproductive advantage for rare-color morphs. Consequently, we performed an experiment varying the relative frequency of the two color morphs of D. sambucina to test whether rare morph advantage acted in the natural habitat of the species. We show here clear evidence from this manipulative experiment that rare-color morphs have reproductive advantage through male and female components. This is the first demonstration, to our knowledge, that negative frequency-dependent selection through pollinator preference for rare morphs can cause the maintenance of a flower-color polymorphism.

Color↗
PubMed2001

Prediction of principal metal-binding solid phases in estuarine sediments from color image analysis.

A novel application of image analysis technology to the semiquantitative determination of the strong metal-binding phases of hydrous ferric oxides and acid-volatile sulfides in muddy estuarine sediments is presented. Sediment cores were split in the laboratory, photographed in cross-section, and subsampled for solid-phase analyses. The images were processed using commercially available software packages. Concentrations of FeOOH and AVS were found to be linearly related to elementary color parameters (saturation and intensity, respectively) at corresponding points on the images. Spatially resolved information on metal-binding capacity can thereby be estimated from such images; selected depth profiles are generated as examples.

Color↗
PubMed2001

[Epiluminescent microscopy aspects of initial cutaneous melanoma metastases].

BACKGROUND AND OBJECTIVE: Especially small and initial cutaneous melanoma metastases (CMMs) are tumours with inconspicuous clinical and sometimes histological features which may be difficult to differentiate from other melanocytic lesions. The present study was performed to determine whether epiluminescence microscopic (ELM) criteria could increase the accuracy in preoperative evaluation of CMMs. PATIENTS/METHODS: Thirty photographed and histologically verified CMMs were examined retrospectively using ELM in order to visualize a multitude of morphological features permitting the recognition of malignancy. The colour slides obtained by the photography were subjected to a secondary 30-80 fold magnification in order to conduct a visual analysis. The 50 naevi in the control group were all histologically benign. RESULTS: Five of the 15 features studied were shown to differ significantly between the two groups. Polymorphic angiectatic base pattern and vascular aneurysms, areas of polymorphic and horizontally dilated capillaries, peripheral erythema, saccular pattern and a light brown halo had a specificity of 90-98% and a sensitivity of 40-46% for CMMs (p<0.001). Peripheral grayish patches, lesions surrounded by gray streaks and microscopic ovoid blood lakes were absent in the benign group. CONCLUSIONS: The prevalence of distinct ELM criteria in CMMs enhances the diagnostic accuracy of malignancy in melanocytic skin lesions.

Color↗