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

Stabilize the participant's head on the posterior half of the head coil of a Magnetic resonance imaging, or MRI, machine.

Place a mirror to reflect visual stimuli from a screen to stimulate the brain's visual cortex.

The visual cortex processes visual information from the eye's retina.

Acquire structural images of the brain to serve as anatomical references.

Acquire functional MRI images to measure baseline brain activity.

Without stimulation, neurons require less oxygen for metabolism, resulting in deoxygenated blood in the brain.

The magnetic properties of deoxygenated hemoglobin in the blood distort the MRI magnetic field, resulting in a weak signal.

Next, display visual stimuli to stimulate neurons in the visual cortex.

The increased energy demand of the stimulated neurons prompts a flow of oxygenated blood. Lowering deoxygenated hemoglobin levels reduces distortion in the magnetic field, enhancing the signal strength.

Using the blood oxygen level-dependent signal, measure activity in the stimulated visual cortex.

Begin by instructing the participant to fixate on the central cross during the imaging scans. Briefly demonstrate the visual stimulation to familiarize the participant with th