Herbst, A. | bioRxiv Science

bioRxiv2019

Methods for combining multiple correlated biomarkers with application to the study of low-grade inflammation and muscle mass in senior horses

The simplest analysis of biomarker data is based on a series of single biomarker hypothesis tests, followed by correction for multiple testing. However, it is intuitively plausible that a joint analysis of multiple biomarkers will have higher statistical power and promise improved discrimination over tests based on single markers. In this article, we study analytical properties of the approach for joint analysis of correlated summary statistics based on the test for quadratic forms (TQ). Based on the derivation of the TQ-distribution, we proposed a scale-location approximation of the TQ statistic, which we call approximate TQ. We show that the approximate TQ has very similar power to the traditional TQ test under varying correlation structures among biomarkers. Our application of both the TQ and the approximate TQ test to data on biomarkers for inflamm-aging - an age-related low-grade chronic inflammation - reveals an association between the percentage of IFN{gamma} positive lymphocytes and overall muscle condition in senior horses.

genetics↗

bioRxiv2019

Brain, music and emotion: An EEG proof-of-concept study on musically continuous, non-personalized emotional responses

It has been repeatedly reported that motivation for listening to music is majorly driven by the latters emotional effect. There is a relative opposition to this approach, however, suggesting that music does not elicit true emotions. Counteracting this notion, contemporary research studies indicate that listeners do respond affectively to music providing a scientific basis in differentially approaching and registering affective responses to music as of their behavioral or biological states. Nevertheless, no studies exist that combine the behavioral and neuroscientific research domains, offering a cross-referenced neuropsychological outcome, based on a non-personalized approach specifically using a continuous response methodology with ecologically valid musical stimuli for both research domains. Our study, trying to fill this void for the first time, discusses a relevant proof-of-concept protocol, and presents the technical outline on how to multimodally measure elicited responses on evoked emotional responses when listening to music. Specifically, we showcase how we measure the structural music elements as they vary from the beginning to the end within two different compositions, suggesting how and why to analyze and compare standardized, non-personalized behavioral to electroencephalographic data. Reporting our preliminary findings based on this protocol, we focus on the electroencephalographic data collected from n=13 participants in two separate studies (i.e., different equipment and sample background), cross-referencing and cross-validating the biological side of the protocols structure. Our findings suggest (a) that all participants - irrespectively of the study - reacted consistently in terms of hemispheric lateralization for each stimulus (i.e., uniform intra-subjective emotional reaction; non-statistically significant differentiation in individual variability) and (b) that diverse patterns of biological representations emerge for each stimulus between the subjects in the two studies (variable inter-subjective emotional reaction; statistically significant differentiation in group variability) pointing towards exogenous to the measurements process factors. We conclude discussing further steps and implications of our protocol approach.

neuroscience↗