What Is the Test Retest Reliability of Common Task Functional MRI Measures? New Empirical Evidence and a Meta Analysis
Identifying brain biomarkers of disease risk is a growing priority in neuroscience. The ability to identify meaningful biomarkers is limited by measurement reliability; unreliable measures are unsuitable for predicting clinical outcomes. Measuring brain activity using task functional MRI (fMRI) is a major focus of biomarker development; however, the reliability of task fMRI has not been systematically evaluated. We present converging evidence demonstrating poor reliability of task fMRI measures. First, a meta analysis of 90 experiments (N 1,008) revealed poor overall reliability mean intraclass correlation coefficient (ICC) .397. Second, the test retest reliabilities of activity in a priori regions of interest across 11 common fMRI tasks collected by the Human Connectome Project (N 45) and the Dunedin Study (N 20) were poor (ICCs .067 .485) Collectively, these findings demonstrate that common task fMRI measures are not currently suitable for brain biomarker discovery or for individual differences research. We review how this state of affairs came to be and highlight avenues for improving task fMRI reliability.
Psychological science