Beyond the canonical HRF: Flexible temporal modeling reveals unconstrained BOLD profiles during naturalistic viewing.

Overview

1. Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States

Abstract

Naturalistic stimuli, such as movies and narratives, are increasingly used in cognitive neuroscience to map cognitive and affective processes onto brain activity measured with functional MRI (fMRI). Features extracted from movies span multiple levels, from computational visual and auditory inputs to physiological signals and subjective ratings. However, the temporal alignment between these features and the blood-oxygen-level-dependent (BOLD) response varies considerably, and the commonly used canonical hemodynamic response function (HRF) with temporal derivatives may not adequately capture these delays. In this study, we analyzed three movie-watching datasets using cross-correlation and finite impulse response (FIR) deconvolution to map the unconstrained temporal dynamics of visual, auditory, pupillary, and Theory of Mind (ToM) features across the brain. Our results demonstrate that while the canonical HRF effectively captures basic sensory features, it introduces systematic misalignments for inherently delayed signals. Because physiological markers (pupil size) and subject reports (ToM) intrinsically lag the underlying neural events, standard HRF convolution overcompensates for their biological latency, introducing a redundant phase mismatch or “double-delay.” Furthermore, our unconstrained FIR models revealed distinct inter-regional temporal hierarchies across the cortex. Given the inherent collinearity of real-world stimuli, these estimated profiles capture the bundled, multi-dimensional dynamics of naturalistic processing rather than perfectly isolated feature effects. Overall, these findings highlight the necessity of flexible, reliability-tested temporal modeling to accurately map the complex processing timescales engaged during naturalistic viewing.

Reproduced under the paper's license (CC BY), from the paper cited above.

Code

No file of the authors' code could be read here: it is described below, and read at its source.

The paper's code and data availability statement is in the Data section.

Tracing map

Proposed by the machine: these links were found in the paper and verified at the source, without human review. The map will receive a Zenodo DOI once one of the paper's authors has validated it with their ORCID.

What the map holds:

• 1 repository of the authors' code, each at its verified commit, with its license and how the link was found in the paper;
• 0 scripts, each with its path and the digest of its content;
• no match between paragraphs and code yet;
• neither the text of the paper nor the code itself.

Its JSON (tracing-map.json) is deposited on Zenodo with its DOI once the map is validated.

Data

Datasets cited

• openneuro:ds000228, at OpenNeuro; found in the text, “Partly cloudy dataset”

Data and Code Availability

MRI and pupil size data were obtained from publicly available sources: the Healthy Brain Network (HBN) dataset (http://fcon_1000.projects.nitrc.org/indi/cmi_healthy_brain_network/) and the OpenNeuro repository (https://openneuro.org/datasets/ds000228). The Theory of Mind (ToM) rating data and analysis scripts are publicly available on the Open Science Framework (OSF) repository: https://osf.io/qky8p.

Reproduced under the paper's license (CC BY), from the paper cited above.

Versions

The history of this record: each version stored by the harvester or made by a correction of its authors or of the maintainers of its code, and what changed in its facts. The texts of the paper (its abstract, its availability statements) are not part of it; versions that changed only those are not listed.

Version 1, 27 September 2026: the first record

Recorded: type, language, journal, volume, pages, dates, 3 authors, 7 keywords, 2 funders, 52 references.

Cite

This paper

Di, X., Hanna, G. B., & Biswal, B. B. (2026). Beyond the canonical HRF: Flexible temporal modeling reveals unconstrained BOLD profiles during naturalistic viewing. Imaging neuroscience (Cambridge, Mass.), 4, IMAG.a.1331. https://doi.org/10.1162/imag.a.1331

The tracing map gets a citation of its own once an author has validated it and it has a DOI.

Similar papers

The papers with a page that share the most with this one: the tools found in their code, their categories, datasets, cited references and authors, the rarest counting most.

[1] doi:10.1093/psyrad/kkag026 [code]

fMRI-based prediction of eye gaze during naturalistic movie viewing reveals eye-movement-related brain activity.

Journal: Psychoradiology

In common: OpenNeuro ds000228, fMRI, 4 references, author Xin Di

[2] doi:10.1111/ejn.70543 [code]

Neural Oscillations Track Subjective and Pupillary Arousal During Naturalistic Movie Viewing.

Journal: The European journal of neuroscience

In common: 8 references

[3] doi:10.1162/imag.a.1347 [code]

Neural and behavioural correlates of theory of mind reasoning in five-year-old children born preterm.

Journal: Imaging neuroscience (Cambridge, Mass.)

In common: OpenNeuro ds000228, fMRI, 4 references

[4] doi:10.1038/s41467-026-71151-2 [code]

Common and distinct neural correlates of social interaction processing and theory of mind in narratives.

Journal: Nature communications

In common: 6 references

[5] doi:10.1162/imag.a.1300 [code]

Mapping the movie-watching brain with AI-derived semantics.

Journal: Imaging neuroscience (Cambridge, Mass.)

In common: fMRI, 5 references

[6] doi:10.1371/journal.pone.0355165 [code]

Pupillary dynamics during hands-off L2 driving and transitions of control under high cognitive load.

Journal: PloS one

In common: 6 references

[7] doi:10.7554/elife.99278 [code]

Brain-wide arousal signals are segregated from movement planning in the superior colliculus of the macaque.

Journal: eLife

In common: 6 references

[8] doi:10.7554/elife.110294 [code]

Arousal modulates functional connectivity through structured and hemispherically asymmetric community architecture during wakefulness.

Journal: eLife

In common: fMRI, 5 references

[9] doi:10.1038/s41597-026-07676-4 [code]

A neuroimaging dataset combining movie-watching, eye-tracking, sensorimotor mapping, and cognitive tasks.

Journal: Scientific data

In common: 5 references

[10] doi:10.1016/j.dcn.2026.101765 [code]

Fusiform face area development correlates with development in higher-order social brain regions.

Journal: Developmental cognitive neuroscience

In common: OpenNeuro ds000228, fMRI, 1 reference

Contribute

The authors of this paper can claim it, correct its record and validate its tracing map, and the maintainers of its code (its owner, or a public member of its organization) correct what it says of their repository; anyone signed in can ask for its removal. Every request goes to OSCR's own machine, which answers it; your account page follows them.

Request its removal

To ask OSCR to remove this record, the copies of its authors' scripts or its tracing map, use the removal request page: signed in, you say who you are, what to remove and why, then review and confirm the request. Published rules decide every request (how).

Discussion: questions and error reports about this paper and its code, from signed-in readers and its authors. It opens with sign-in.

Reproductions: reports from readers who ran the authors' code: what they reproduced, with which environment, commit and data. It opens with sign-in.

Activity: what happens around this paper: new versions of its record, its map's validation, discussions and reproductions. It opens with sign-in.