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A Riquenes

Publications and source records attributed to A Riquenes.

2 recordsLinked to original sources

Automatic detection of auditory brainstem responses using feature vectors.

The efficiency of several methods for the automatic detection of near threshold auditory brainstem responses (ABRs), based on feature vectors, was assessed on a sample of 374 recordings obtained from neonates. Features are quantitative descriptors of different aspects of the response commonly taken into consideration by expert ABR judges, such as: similarity with a template, reliability of the response, and intrinsic morphological characteristics. The classification methods used were: comparisons of individual features with a threshold, linear discriminant functions based on combination of features, artificial neural networks (ANNs) based on the raw ABR, and ANNs based on combinations of features. The network used was a modified version of the Fuzzy ART Map model. The accuracy of the classification into normal and abnormal (as previously scored by a panel of experts) was assessed with methods from signal detection theory. Our results showed that the approaches based on feature vectors (discriminant function and ANN) performed more efficiently than the ANN with raw data, or the individual features.

Algorithms↗

A global scale factor in brain topography.

In this paper statistical resampling techniques are used to support the presence of an equiangular first principal component in EEG log spectra and therefore the existence of a global scale factor in EEG recordings. the Log transformed spectra from a normal sample (n = 211, age 5-97) were analyzed. To reach this conclusion a method for estimating the scale factor is introduced. It is also shown that this factor remains constant in each individual for all derivations and frequencies and across functional states. The contribution of this scale factor to the overall variance of the normal EEG reaches 42% of the total variance of age corrected data. Part of the variance of the scale factor exhibits age dependency. Scale factor correction of EEG spectra data improves the diagnostic accuracy for detecting pathological EEG spectra from an almost random level (Area under the ROC curve = .6) to .84.

Adolescent↗