Frequency spectrum might act as communication code between retina and visual cortex Ⅰ

AIM: To explore changes and possible communication relationship of local potential signals recorded simultaneously from retina and visual cortex I(V1).·METHODS: Fourteen C57BL/6J mice were measured with pattern electroretinogram(PERG) and pattern visually evoked potential(PVEP) and fast Fourier transform has been used to analyze the frequency components of those signals.· RESULTS: The amplitude of PERG and PVEP was measured at about 36.7 μV and 112.5 μV respectively and the dominant frequency of PERG and PVEP, however,stay unchanged and both signals do not have second, or otherwise, harmonic generation.· CONCLUSION: The results suggested that retina encodes visual information in the way of frequency spectrum and then transfers it to primary visual cortex.The primary visual cortex accepts and deciphers the input visual information coded from retina. Frequency spectrum may act as communication code between retina and V1.

Visual Functions and TraceElement Metabolism in Tobacco-toxic Optic Neuropathy

Visual functions and nutrition metabolic characteristics werestudied in 8 subjects(16 eyes)with tobacco-toxic optic neuropathy(TTON).Their visual functions tested by psychophysical and electrophysiologicmethods showed that:1.central vision diminished in 16 eyes,2.dyschromatopsias were found in 14 tested eyes,3.bilateral symmetricalcentral or cecocentral scotomas were the visual field characteristics in allcases,4.PVEP were severe abnormal in 3 spatial frequencies in all cases and56.3% of 15' checkboard ...

Evaluation of a Pointwise Local Visual Pattern Exploration Method

Sensitivity analysis is a powerful method for discovering the significant factors that contribute to understanding the interaction between variables in multivariate datasets. A number of sensitivity analysis methods fall into the class of local analysis, in which the sensitivity is defined as the partial derivatives of a target variable with respect to a group of independent variables. In a recent paper, we presented a novel pointwise local pattern exploration system for visual sensitivity analysis. Using this system, analysts are able to explore local patterns and the sensitivity at individual data points, which reveals the relationships between a focal point and its neighbors this paper we present several evaluations of the system, including case studies with real datasets, user studies the effectiveness of the visualizations and interactions, and a detailed description of the experience of a user In on

Visual polysemy and synonymy:toward near-duplicate image retrieval

that are duplicate or near duplicate to a query image.One of the most popular and practical methods in near-duplicate image retrieval is based on bag-of-words(BoW)model.However,the fundamental deficiency of current BoW method is the gap between visual word and image’s semantic meaning.Similar problem also plagues existing text retrieval.A prevalent method against such issue in text retrieval is to eliminate text synonymy and polysemy and therefore improve the whole performance.Our proposed approach borrows ideas from text retrieval and tries to overcome these deficiencies of BoW model by treating the semantic gap problem as visual synonymy and polysemy issues.We use visual synonymy in a very general sense to describe the fact that there are many different visual words referring to the same visual meaning.By visual polysemy,we refer to the general fact that most visual words have more than one distinct meaning.To eliminate visual synonymy,we present an extended similarity function to implicitly extend query visual words.To eliminate visual polysemy,we use visual pattern and prove that the most efficient way of using visual pattern is merging visual word vector together with visual pattern vector and obtain the similarity score by cosine function.In addition,we observe that there is a high possibility that duplicates visual words occur in an adjacent area.Therefore,we modify traditional Apriori algorithm to mine quantitative pattern that can be defined as patterns containing duplicate items.Experiments prove quantitative patterns improving mean average precision(MAP)significantly.

Single-Trial Estimation and Analysis of PVEP Based on Independent Component Analysis

A novel method based on the extended infomax approach of independent component analysis (ICA) is proposed for the single trial estimation of multi channel pattern reversal visual evoked potential (PVEP). The clinical applications illustrate the encouraging performance of the method. The number of trials needed is reduced to 3, but the estimated VEP complex is clearer than that obtained by conventional ensemble averaging with 50 trials. By analyzing the time course and spatial pattern of the independent components (ICs) of the multi channel PVEP, one component is found to be reasonably related to the P100 peak.