Eye-selective fMRI activity in human primary visual cortex: Comparison between 3 T and 9.4 T, and effects across cortical depth
| Autor: | Andreas Bartels, Klaus Scheffler, N Zaretskaya, Jonathan R. Polimeni, Jonas Bause, P Grassi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Adult
Male genetic structures Ultrahigh field MRI Cognitive Neuroscience media_common.quotation_subject Partial volume Field strength computer.software_genre Signal 050105 experimental psychology Ocular dominance lcsh:RC321-571 03 medical and health sciences Young Adult 0302 clinical medicine Nuclear magnetic resonance Voxel medicine Image Processing Computer-Assisted Contrast (vision) Humans 0501 psychology and cognitive sciences lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry media_common Visual Cortex Physics V1 Cortical layers 05 social sciences fMRI Magnetic Resonance Imaging eye diseases Visual cortex medicine.anatomical_structure 9.4 T Neurology Female sense organs computer 030217 neurology & neurosurgery Ocular dominance column |
| Zdroj: | NeuroImage, Vol 220, Iss, Pp 117078-(2020) NeuroImage |
| ISSN: | 1095-9572 |
| Popis: | The primary visual cortex of humans contains patches of neurons responding preferentially to stimulation of one eye (the ocular dominance columns). Multiple previous studies attempted to detect their activity using fMRI. The majority of these fMRI studies used magnetic field strengths of 4 T and higher. However, there have been reports of reliable eye-selective activations at 3 T as well. In this study we investigated the possibility of detecting eye-selective V1 activity using high-resolution GE-EPI fMRI at 3 T and sub-millimeter resolution fMRI at ultrahigh 9.4 T magnetic field strengths with acquisition parameters optimized for each field strength. High-resolution fMRI at 9.4 T also allowed us to examine the eye-selectivity responses across the cortical depth, which are expected to be strongest in the middle layers. We observed a substantial increase in the percentage of eye-selective voxels, as well as a doubling in run-to-run consistency of eye preference at ultrahigh field compared to 3 T. We also found that across cortical depth, eye selectivity increased towards the superficial layers, and that signal contrast increased while noise remained nearly constant towards the surface. The depth-resolved results are consistent with a distortion of spatial specificity of the GE-EPI signal by ascending venules and large draining veins on the cortical surface. The effects of larger vessels cause increasing signal amplitude, but also displacement of the maximum BOLD signal relative to neural activity. In summary, our results show that increase in spatial resolution, reduced partial volume effects, and improved sensitivity at 9.4 T allow for better detection of eye-selective signals related to ocular dominance columns. However, although ultrahigh field yields higher sensitivity to the ocular dominance signal, GE-EPI still suffers from specificity issues, with a prominent signal contribution at shallow depths from larger cortical vessels. |
| Databáze: | OpenAIRE |
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