Related Experiment Video
Updated: Aug 15, 2025
10:07
Using Fiberless, Wearable fNIRS to Monitor Brain Activity in Real-world Cognitive Tasks
Published on: December 2, 2015
27.1K
Estimation of neuronal task information in fMRI using zero frequency resonator.
Sukesh Kumar Das1, Anil K Sao2, Bharat B Biswal3
1Indian Institute of Technology Mandi, Mandi, HP 175005, Himachal Pradesh, India.
Neuroimage
|January 7, 2023
Summary
This study introduces a novel zero frequency resonator (ZFR) method to accurately estimate temporal onsets of blood oxygen level-dependent (BOLD) events in functional magnetic resonance imaging (fMRI). This approach improves functional connectivity analysis by identifying true neural activity more reliably.
Area of Science:
- Neuroimaging
- Signal Processing
- Biophysics
Background:
- Accurate estimation of temporal onsets of blood oxygen level-dependent (BOLD) events in functional magnetic resonance imaging (fMRI) is critical for analyzing functional connectivity (FC).
- Conventional methods for BOLD event onset estimation often rely on high BOLD signal values, which can lead to inaccuracies due to non-neuronal activity or exclusion of low-valued true signals.
Purpose of the Study:
- To present a novel approach for estimating BOLD event temporal onsets using a zero frequency resonator (ZFR) without requiring experimental paradigm (EP) information.
- To leverage the impulse-like characteristics of neural activity for precise onset detection.
- To improve the accuracy of functional connectivity (FC) analysis in fMRI.
Main Methods:
- Utilized a zero frequency resonator (ZFR), a technique from speech signal processing, to identify temporal onsets of BOLD events.
- Exploited the principle that ideal neuronal impulses possess energy across all frequencies, including zero frequency, preserving onset information.
- Estimated task-induced temporal onsets and high signal-to-noise ratio (HSNR) regions around BOLD events for FC analysis.
Main Results:
- The ZFR-based approach successfully estimated BOLD event onsets and HSNR regions from both synthetic and experimental fMRI data (event-related finger tapping, block design working memory).
- Demonstrated that a minimal set of ZFR-identified time points effectively captures activation patterns.
- Showcased the superiority of the ZFR method over conventional correlation and threshold-based conditional rate analyses for FC estimation.
Conclusions:
- The proposed ZFR-based method offers a robust and accurate way to estimate BOLD event onsets in fMRI, independent of experimental paradigms.
- The identified BOLD events and HSNR regions using ZFR provide sufficient information to characterize brain functionality during task performance.
- This novel approach enhances the reliability and precision of functional connectivity analysis in neuroimaging studies.
