Assessing Time Series Correlation Significance: A Parametric Approach with Application to Physiological Signals

Fuente: arXiv
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Main Authors: Medrano, Johan, Kheddar, Abderrahmane, Ramdani, Sofiane
Format: Preprint
Published: 2024
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author Medrano, Johan
Kheddar, Abderrahmane
Ramdani, Sofiane
author_facet Medrano, Johan
Kheddar, Abderrahmane
Ramdani, Sofiane
contents Correlation coefficients play a pivotal role in quantifying linear relationships between random variables. Yet, their application to time series data is very challenging due to temporal dependencies. This paper introduces a novel approach to estimate the statistical significance of correlation coefficients in time series data, addressing the limitations of traditional methods based on the concept of effective degrees of freedom (or effective sample size, ESS). These effective degrees of freedom represent the independent sample size that would yield comparable test statistics under the assumption of no temporal correlation. We propose to assume a parametric Gaussian form for the autocorrelation function. We show that this assumption, motivated by a Laplace approximation, enables a simple estimator of the ESS that depends only on the temporal derivatives of the time series. Through numerical experiments, we show that the proposed approach yields accurate statistics while significantly reducing computational overhead. In addition, we evaluate the adequacy of our approach on real physiological signals, for assessing the connectivity measures in electrophysiology and detecting correlated arm movements in motion capture data. Our methodology provides a simple tool for researchers working with time series data, enabling robust hypothesis testing in the presence of temporal dependencies.
format Preprint
id arxiv_https___arxiv_org_abs_2401_02387
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Assessing Time Series Correlation Significance: A Parametric Approach with Application to Physiological Signals
Medrano, Johan
Kheddar, Abderrahmane
Ramdani, Sofiane
Methodology
Quantitative Methods
Applications
Correlation coefficients play a pivotal role in quantifying linear relationships between random variables. Yet, their application to time series data is very challenging due to temporal dependencies. This paper introduces a novel approach to estimate the statistical significance of correlation coefficients in time series data, addressing the limitations of traditional methods based on the concept of effective degrees of freedom (or effective sample size, ESS). These effective degrees of freedom represent the independent sample size that would yield comparable test statistics under the assumption of no temporal correlation. We propose to assume a parametric Gaussian form for the autocorrelation function. We show that this assumption, motivated by a Laplace approximation, enables a simple estimator of the ESS that depends only on the temporal derivatives of the time series. Through numerical experiments, we show that the proposed approach yields accurate statistics while significantly reducing computational overhead. In addition, we evaluate the adequacy of our approach on real physiological signals, for assessing the connectivity measures in electrophysiology and detecting correlated arm movements in motion capture data. Our methodology provides a simple tool for researchers working with time series data, enabling robust hypothesis testing in the presence of temporal dependencies.
title Assessing Time Series Correlation Significance: A Parametric Approach with Application to Physiological Signals
topic Methodology
Quantitative Methods
Applications
url https://arxiv.org/abs/2401.02387