Temporospatial components of brain ERPs as biomarkers for Alzheimer's disease

IntroductionDeveloping biomarkers that distinguish individuals with Alzheimer's disease (AD) from those with normal cognition remains a crucial goal for improving the health of older adults. We investigated adding brain spatial information to temporal event-related potentials (ERPs) to increase AD identification accuracy over temporal ERPs alone.MethodsWith two-step principal components analysis, we applied multivariate analyses that incorporated temporal and spatial ERP information from a cognitive task. Discriminant analysis used temporospatial ERP scores to classify participants as belonging to either the AD or healthy control group.ResultsTemporospatial ERPs produced a cross-validated area under the curve of 0.84. Adding spatial information through a formal procedure significantly improves classification accuracy.DiscussionA weighted combination of temporospatial ERP markers performs well in detecting AD. Because ERPs are noninvasive and inexpensive, they may be promising biomarkers for AD that can add functional information to other biomarker systems while providing the individual's probability of correct classification

The construction of sex discriminant functions from a large collection of skulls of known sex

Abstract The suitability of the large collection of skulls of known sex (n?=357, n?=213), housed in the Department of Anthropology of the University of Coimbra, as a reference series for sex diagnosis from skulls, was investigated. This was done by calculating estimates for the maximum actual discriminatory value for samples being diagnosed. here called Dt max. The estimates for this statistic were found to be relatively low. Depending on the estimation procedure used, values of 1.68 and 1.64, were obtained, which correspond with theoretical percentages of correct classification of 79.8 and 79.3, respectively. An attempt was then made to investigate whether the low level of sexual dimorphism was due to heterogeneity in the series, which was therefore partitioned into Northern, Central and Southern groups according to place of birth. Only in the Southern group was the level of sexual dimorphism found to be slightly higher than in the whole series. The need for large well documented reference series for deriving techniques for sex determination from the skull and other skeletal elements is discussed and an extensive description of the methods emploved in this study is given

A Research Note on Discrimination in Mortgage Lending

This paper examines the hypothesis that mortgage lenders rank applications from better to worst and encourage the better ones to apply. A second ranking occurs when the application is ranked by the loan committee and funds are approved from the top of the list until exhausted. A theoretically correct procedure for analyzing the resulting multivariate ordinal data is the little known rank multiple discriminant analysis. Preliminary results have revealed that this technique produces a "best" model with fewer variables and a higher classification rate than the commonly known multiple discriminant analysis, logit, or probit. Copyright American Real Estate and Urban Economics Association.