Laminar specific fMRI reveals directed interactions in distributed networks during language processing

Research output: Contribution to journalArticle

Authors

  • Daniel Sharoh
  • Tim van Mourik
  • Lauren Bains
  • Kirsten Weber
  • Peter Hagoort
  • David G Norris

Abstract

Interactions between top-down and bottom-up information streams are integral to brain function but challenging to measure noninvasively. Laminar resolution, functional MRI (lfMRI) is sensitive to depth-dependent properties of the blood oxygen level-dependent (BOLD) response, which can be potentially related to top-down and bottom-up signal contributions. In this work, we used lfMRI to dissociate the top-down and bottom-up signal contributions to the left occipitotemporal sulcus (LOTS) during word reading. We further demonstrate that laminar resolution measurements could be used to identify condition-specific distributed networks on the basis of whole-brain connectivity patterns specific to the depth-dependent BOLD signal. The networks corresponded to top-down and bottom-up signal pathways targeting the LOTS during word reading. We show that reading increased the top-down BOLD signal observed in the deep layers of the LOTS and that this signal uniquely related to the BOLD response in other language-critical regions. These results demonstrate that lfMRI can reveal important patterns of activation that are obscured at standard resolution. In addition to differences in activation strength as a function of depth, we also show meaningful differences in the interaction between signals originating from different depths both within a region and with the rest of the brain. We thus show that lfMRI allows the noninvasive measurement of directed interaction between brain regions and is capable of resolving different connectivity patterns at submillimeter resolution, something previously considered to be exclusively in the domain of invasive recordings.

Details

Original languageEnglish
Pages (from-to)21185-21190
Number of pages6
JournalNational Academy of Sciences. Proceedings
Volume116
Issue number42
Publication statusPublished - 15 Oct 2019

Keywords

  • laminar fMRI, systems neuroscience, BOLD, biophysics, directed connectivity, language

ASJC Scopus subject areas