PD Dr Gabriele Lohmann | Cylarim: A novel Software for Spatially-Resolved Statistical Inference in Laminar fMRI

Laminar fMRI offers a powerful approach to investigate brain function by resolving neural activity across

the distinct layers of the cortical gray matter. However, current laminar fMRI analysis methods often rely

on predefined regions of interest (ROIs), which introduces subjectivity and bias due to arbitrary spatial delineation.

To address this limitation, we present Cylarim, a novel software package that not only eliminates dependence

on rigid ROI definitions but, critically, is also the first of its kind to provide spatially-resolved

statistical inference for laminar fMRI.

Cylarim employs small, overlapping cylinders that systematically traverse the cortical ribbon,

enabling unbiased, large-scale mapping of laminar-specific hemodynamic activity.

This approach supports comprehensive sampling of cortical depth-resolved signals across extensive regions,

generating entire statistical maps rather than just single p-values. By circumventing the need for manual

or atlas-driven ROI selection, Cylarim facilitates the study of feedforward and feedback pathways in

diverse cortical areas without compromising spatial coverage.

Results on publicly available data demonstrate Cylarim's ability

to accurately localize layer-dependent responses, providing a robust framework for advancing

ultrahigh-resolution fMRI research in neuroscience.