Blood Oxygen Level-Dependent Functional Magnetic Resonance Imaging of the Visual Cortex

Abstract

Source: Galenchik-Chan, A., et al. Functional Magnetic Resonance Imaging (fMRI) of the Visual Cortex with Wide-View Retinotopic Stimulation. J. Vis. Exp. (2023).

The video demonstrates functional magnetic resonance imaging (fMRI) of the visual cortex to map activity based on blood oxygenation levels. Structural MRI images are acquired as anatomical references, followed by fMRI scans. Visual stimuli are displayed to activate retinotopic neurons in the visual cortex. The increased energy demand of these stimulated neurons drives the flow of oxygenated blood, reducing deoxyhemoglobin and enhancing the fMRI signal to measure activity.

Protocol

All procedures involving human participants have been performed in compliance with the institutional, national, and international guidelines for human welfare and have been reviewed by the local institutional review board.

Results

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
3T MRI scanner	Siemens
6-32 nylon machine screws, rounded head			to attach mirror/screen to rod
8-channel head array coil	Siemens
Acrylic mirror			Width and length of 25-30cm
E-Prime	Psychology Software Tools		to prepare and present visual stimuli paradigms
Rear projection screen			Size should be at least as large as the scanner bore