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fMRI: Functional Magnetic Resonance Imaging

JoVE 5212

Functional magnetic resonance imaging (fMRI) is a non-invasive neuroimaging technique used to investigate human brain function and cognition in both healthy individuals and populations with abnormal brain states. Functional MRI utilizes a magnetic resonance signal to detect changes in blood flow that are coupled to neuronal activation when a specific task is performed. This is possible because hemoglobin within the blood has different magnetic properties depending on whether or not it is bound to oxygen. When a certain task is performed, there is an influx of oxygenated blood to brain regions responsible for that function, and this influx can then be detected with specific MRI scan parameters. This phenomenon is termed the blood oxygen level ependent (BOLD) effect, and can be used to create maps of brain activity. This video begins with a brief overview of how MRI and fMRI signal is obtained. Then, basic experimental design is reviewed, which involves first setting up a stimulus presentation that is specifically designed to test the function that will be mapped. Next, key steps involved in performing the fMRI scan are introduced, including subject safety and setting up at the scanner. Commonly used steps for data processing are then presented, including pre-processing and statistical analysis with the general linear


 Neuroscience

fMRI Validation of fNIRS Measurements During a Naturalistic Task

1Department of Psychiatry, Yale School of Medicine, 2Department of Electronics and Bioinformatics, Meiji University, 3Department of Histology and Neurobiology, Dokkyo Medical University School of Medicine, 4ADAM Center, Department of Physical Therapy, Movement and Rehabilitation Sciences, Northeastern University, 5Department of Neurobiology, Yale School of Medicine

JoVE 52116


 Behavior

Motor Maps

JoVE 10175

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

One principle of brain organization is the topographic mapping of information. Especially in sensory and motor cortices, adjacent regions of the brain tend to represent information from adjacent parts of the body, resulting in maps of the body expressed on the surface of the brain. The primary sensory and motor maps in the brain surround a prominent sulcus known as the central sulcus. The cortex anterior to the central sulcus is known as the precentral gyrus and contains the primary motor cortex, while the cortex posterior to the central sulcus is known as the postcentral gyrus and contains the primary sensory cortex (Figure 1). Figure 1: Sensory and motor maps around the central sulcus. The primary motor cortex, which contains a motor map of the body's effectors, is anterior to the central sulcus, in the precentral gyrus of the frontal lobe. The primary somesthetic (sensory) cortex, which receives touch, pain, and temperature information from the external parts of the body, is located posterior to the central sulcus, in the postcentral gyrus of the parietal lobe.

Microstate and Omega Complexity Analyses of the Resting-state Electroencephalography

1Department of Pain Medicine, Peking University People's Hospital, 2Key Laboratory of Child Development and Learning Science of Ministry of Education, Research Center for Learning Science, School of Biological Sciences & Medical Engineering, Southeast University

Video Coming Soon

JoVE 56452


 JoVE In-Press

Finding Your Blind Spot and Perceptual Filling-in

JoVE 10195

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University

In the back of everyone's eye is a small piece of neural tissue called the retina. The retina has photosensitive cells that respond to stimulation by light. The responses of these cells are sent into the brain through the optic nerve, a bundle of neural fibers. In each retina there is a place somewhere in the periphery where the outputs from retinal cells collect and the bundled optic nerve exits to the brain. At that location, there is no photosensitivity-whatever light reflects from the world and lands in that position does not produce a signal in the brain. As a result, humans have a blind spot, a place in the visual field for which they don't process incoming stimuli. However, people are not aware that they have blind spots; there is not an empty hole in the visual images in front of the eyes. So what do people see in their blind spots? The brain actually fills-in missing input based on the surroundings. This video demonstrates how to find a person's blind spot, and how to investigate the mechanisms of perceptual filling-in.


 Sensation and Perception

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