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Photography on the brain
Published in Lester D. Friedman, Therese Jones, Routledge Handbook of Health and Media, 2022
The MRI technique, dating from 1977, is analogous to still photography in that it focuses on brain anatomy while the fMRI technique, dating from 1990, is analogous to cinematography in that it follows neural activity. In other words, MRI studies static anatomy, while fMRI studies physiological function. MRI uses radio waves and magnetic fields to image the brain, while fMRI uses the same techniques to measure changes in oxygen in the blood, thus determining blood flow and, by extension, brain function. There are other brain imaging techniques, but MRI and fMRI are the safest methods and, therefore, are widely used not only for medical diagnosis but also research, including studies intended to visualize and understand how thought works. (Computed tomography (CT) or computed axial tomography (CAT) scans rely upon x-rays of the head from many angles, subjecting the patient to radiation, while positron emission tomography (PET) scans require radioactive material to be injected into the bloodstream.) Magnetic resonance imaging strays from traditional photography in a much greater way than x-rays do, but it is still subject to processes of collecting, processing, and interpreting data through systems comprising cultural biases just as older photographic techniques and practices do. On a basic level, MRI strives for the same thing that Diamond set out to accomplish using photography: to visualize the invisible workings of the mind.
Health, wealth and power
Published in Nigel Crisp, Turning the World Upside Down Again, 2022
Medical imaging has developed enormously with scanners using X-rays, magnetic resonance, positron emissions and sound waves able to assist diagnosis and reduce the need for investigative surgery or for time-consuming biological and chemical tests. As the capability of these grows, scientists and clinicians are able to discover more and more about how our bodies work and interact with the environment. Functional magnetic resonance imaging (fMRI) scanners now allow us to see what brain activity corresponds with our moods and feelings and offers the promise of better understanding of the physical aspects of mental illness.
Introduction
Published in Shoogo Ueno, Bioimaging, 2020
Seiji Ogawa (1934–) in Japan invented fMRI based on blood oxygenation level dependent (BOLD) effects to visualize the functional organizations in the brain in 1990 (Ogawa et al., 1990), and demonstrated the usefulness of fMRI using human subjects (Ogawa et al., 1992). fMRI has been used in a variety of fields from basic brain research to cognitive and social sciences because of its usefulness and non-invasive imaging methodology without any injection of contrast agencies into human subjects. Using the BOLD effect, fMRI is able to detect the functional signals in the brain related to the changes in magnetic susceptibility of oxyhemoglobin (diamagnetism) and deoxyhemoglobin (para-magnetism) in the blood. The BOLD effect reflects on the local spin-spin relaxation T2*, and the changes in T2* are detected as the functional signals associated with neuronal electrical activities.
Altered brain activity and functional connectivity in migraine without aura during and outside attack
Published in Neurological Research, 2023
Luping Zhang, Wenjing Yu, Zhengxiang Zhang, Maosheng Xu, Feng Cui, Wenwen Song, Zhijian Cao
Functional magnetic resonance imaging (fMRI) is the most commonly used method for assessing brain activity. It indirectly measures neural activity by measuring the local changes in blood oxygenation. The amplitude low-frequency fluctuations (ALFF) derived from the resting-state fMRI signals can reflect the regional spontaneous neural activity [8,9]. Functional connectivity (FC) is a method to characterize the temporal neurophysiological activities interactions between brain regions that are spatially remote [10]. Thus, in this study, we used the resting-state functional magnetic resonance imaging (rs-fMRI) method to detect cortical excitability changes and abnormal FC in MWoA-DA and MWoA-DI groups to explore the pathophysiological mechanism of migraine. Additionally, we assessed the relationships between neuroimaging findings and clinical parameters to further explore the relationship between these parameters and the role of these changes in the migraine pathophysiology.
Comparison of Functional Connectivity during Visual-Motor Illusion, Observation, and Motor Execution
Published in Journal of Motor Behavior, 2022
Katsuya Sakai, Junpei Tanabe, Keisuke Goto, Ken Kumai, Yumi Ikeda
The present study has some limitations. First, we did not measure all the ROIs due to the small number of fNIRS probes, and their spatial resolution was wider than other devices (i.e., fMRI). These limitations can be solved by simultaneously including fMRI measurements in future studies. Second, in the OB group, subjects held their right hand in front of the monitor while watching the video image. We had to investigate subject own upper limb had to be considered for inclusion under the monitor using anatomically incongruent video. We speculated that future studies could add an anatomically incongruent video condition to clearly contrast with the IL group. Third, the assessment of degree of kinesthetic illusion and a sense of body ownership was one statement without control statements. Therefore, this assessment method increased the risk of the results being confounded by demand characteristics and suggestion. Finally, this study has a small number of subjects, we will increase the number of subjects in future studies.
Intragastric fructose administration interacts with emotional state in homeostatic and hedonic brain regions
Published in Nutritional Neuroscience, 2022
Julie Iven, Jessica R. Biesiekierski, Dongxing Zhao, Jan Tack, Lukas Van Oudenhove
This study used a randomized, placebo-controlled, single blind, crossover design (2 × 2 within-subject factorial design, partially counterbalanced using Latin Square). The protocol was approved by the Ethics Committee of the Leuven University Hospital, Belgium (Identification Number: S57996) and registered at ClinicalTrials.gov (NCT02946983). Subjects were studied at 8 am after an overnight fast (12 h) on four separate occasions. The study paradigm is summarized in Figure 1. A nasogastric feeding tube (RT8/801, Medicina) and an intravenous cannula were placed at least 15 min before subjects entered the scanner room. The fMRI scan lasted for 50 min, including a baseline scan of 10 min. After the baseline scan, either fructose (25 g, Prodia) dissolved in 250 mL Milli-Q water (Millipore Corporation) or 250 mL Milli-Q water (placebo) was intragastrically administered at body temperature, using a syringe, over a period of 2 min (t = 0). Three minutes before the infusion, induction of sad or neutral emotional state started. Emotion induction was only interrupted briefly at t = 0, 10, 20, 30 and 40 to give participants the opportunity to rate appetite-related sensations and emotional state. Blood samples were collected at t = −10, 10, 20, 30, 40 and 50. After scanning, emotion induction was re-started before the ad libitum milkshake drinking test, where subjects had to drink a rewarding chocolate milkshake until maximal satiation.