Characterization of the hemodynamic response function in default mode network subregions for task-evoked negative BOLD responses
Hengda He, B. G. Yazdi, Amir Sedaghat, S. H. Hojjati, S. Ozoria, Peter Chernek, Jenseric Calimag, F. Feiz, Q. Razlighi
bioRxiv September 19, 2025 preprint DOI: 10.1101/2025.09.19.677202 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational fMRI study |
|---|---|
| Topics | Default mode network |
| Key findings | The authors report that the negative BOLD response is linear with respect to stimulus duration, and that each default mode network sub-region has a unique hemodynamic response function distinct from the positive BOLD HRF and from other DMN regions. Inter-regional variability exceeded inter-task variability, and HRFs were not biased by task performance. They suggest each DMN node may have different neural or vascular mechanisms. |
Abstract
While the hemodynamic response function (HRF) of the positive blood oxygenated level dependent (BOLD) signal is well characterized in the functional magnetic resonance imaging (fMRI) field, studies investigating the shape and properties of the negative BOLD HRF, often observed in the default mode network (DMN) regions, are rare. In this study, we first investigated the linearity of the task-evoked negative BOLD response (NBR) with respect to stimulus duration. Then, we obtained the shape of the HRF from each region of the DMN, using an in-house developed unbiased and robust iterative deconvolution technique. Our results demonstrated that each region of the DMN represented a unique HRF, which was not only substantially different from the HRF of the positive BOLD signal, but also different from the HRF extracted from the other DMN regions. We replicated these findings using different fMRI datasets with distinct task paradigms. When comparing the HRF across DMN sub-regions and across tasks, our results demonstrated a significantly higher inter-regional variability compared to inter-task variability. Furthermore, our performance correlation analysis illustrated that the HRFs in the DMN sub-regions extracted by our iterative FIR method were not biased by the task performance level. Altogether, we demonstrated the linearity of the NBR, introduced a robust HRF extraction approach to obtain a distinct HRF for each DMN sub-regions, which were different from the HRF of the positive BOLD signal. The results suggest there is possibility that each node of the DMN might have different underlying neural and/or vascular mechanisms.
Comparable studies
Other experimental studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Functional connectivity of default mode network components: Correlation, anticorrelation, and causality Healthy subjects | 2008 | Observational study using resting-state fMRI and seed correlation analysis | |
| Patterns of Brain Activity Supporting Autobiographical Memory, Prospection, and Theory of Mind, and Their Relationship to the Default Mode Network Healthy subjects | 2009 | Experimental study using fMRI | |
| Dynamic reconfiguration of the default mode network during narrative comprehension Human subjects | 2016 | Experimental study | |
| Broadband Cortical Desynchronization Underlies the Human Psychedelic State Healthy human participants | 2013 | Experimental study | |
| The brain on art: intense aesthetic experience activates the default mode network Human observers | 2012 | Observational study with fMRI and behavioral analysis |
Citations in the library
Cites 7
- A default mode of brain function Proceedings of the National Academy of Sciences January 16, 2001
- Functional connectivity of default mode network components: Correlation, anticorrelation, and causality Human Brain Mapping January 24, 2008
- Fractionating the Default Mode Network: Distinct Contributions of the Ventral and Dorsal Posterior Cingulate Cortex to Cognitive Control Journal of Neuroscience March 2, 2011
- Deactivation of the Default Mode Network as a Marker of Impaired Consciousness: An fMRI Study PLoS One October 19, 2011
- Dopamine Transporters in Striatum Correlate with Deactivation in the Default Mode Network during Visuospatial Attention PLoS One June 30, 2009
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