Resting state fMRI-based temporal coherence mapping

TL;DR

This paper introduces a novel method called temporal coherence mapping (TCM) to quantify long-range temporal coherence in resting state fMRI data, providing insights into brain organization, function, and cognition.

Contribution

The paper presents the first method to explicitly measure LRTC in the brain using phase space correlation analysis of resting state fMRI signals.

Findings

TCM metrics differentiate signals with varying temporal coherence.

High test-retest reproducibility of TCM metrics in human brain data.

TCM metrics are related to age, sex, and cognitive scores.

Abstract

Long-range temporal coherence (LRTC) is quite common to dynamic systems and is fundamental to the system function. LRTC in the brain has been shown to be important to cognition. Assessing LRTC may provide critical information for understanding the potential underpinnings of brain organization, function, and cognition. To facilitate this overarching goal, we provide a method, which is named temporal coherence mapping (TCM), to explicitly quantify LRTC using resting state fMRI. TCM is based on correlation analysis of the transit states of the phase space reconstructed by temporal embedding. A few TCM properties were collected to measure LRTC, including the averaged correlation, anti-correlation, the ratio of correlation and anticorrelation, the mean coherent and incoherent duration, and the ratio between the coherent and incoherent time. TCM was first evaluated with simulations and then with the large Human Connectome Project data. Evaluation results showed that TCM metrics can successfully differentiate signals with different temporal coherence regardless of the parameters used to reconstruct the phase space. In human brain, TCM metrics except the ratio of the coherent/incoherent time showed high test-retest reproducibility; TCM metrics are related to age, sex, and total cognitive scores. In summary, TCM provides a first-of-its-kind tool to assess LRTC and the imbalance between coherence and incoherence; TCM properties are physiologically and cognitively meaningful.