Improving standards in brain-behavior correlation analyses

Front Hum Neurosci. 2012 May 3;6:119. doi: 10.3389/fnhum.2012.00119. eCollection 2012.

Abstract

Associations between two variables, for instance between brain and behavioral measurements, are often studied using correlations, and in particular Pearson correlation. However, Pearson correlation is not robust: outliers can introduce false correlations or mask existing ones. These problems are exacerbated in brain imaging by a widespread lack of control for multiple comparisons, and several issues with data interpretations. We illustrate these important problems associated with brain-behavior correlations, drawing examples from published articles. We make several propositions to alleviate these problems.

Keywords: Pearson correlation; Spearman correlation; confidence intervals; multiple comparisons; multivariate statistics; outliers; robust statistics; skipped correlation.