Introducing MRI: Functional MRI (55 of 56) 

This is a very cohesive explanation. Thank You!

a really clear explanation of fMRI! Thanks

How the fmri fails to explain the brain In general, naming areas of the brain that light up during different behavioral and affective states, from lassitude to anxiety to just thinking, doesn’t really explain anything because it makes no testable predictions. However, a saving grace is that even intelligent audiences think that it does explain something after all. Indeed, it has been noted that college students more readily accept explanations attended by superfluous or irrelevant information on the brain because of the lay belief that citing activated parts of the brain is the best explanation for mental phenomena. This is akin to knowing anatomically which parts of the body are in motion, but not knowing how these parts work intrinsically and work together to achieve locomotion. These process level distinctions are important but often subtle and require a bit more explanation and fine grain analysis than the mere observation that the shin bone is connected to the ankle bone, or for that matter that the anterior cingulate cortex is connected to the neocortex. The overwhelming reliance on fmri and similar brain scans marginalizes the subtler processes that account for behavior that cannot be measured by the procedure, such as the interconnectedness of neural networks and neurochemical activity in the brain, and the fact that activation of certain areas of the brain can be manifested by widely different affective outcomes. For example, activation of the amygdala can reflect “anxiety” about a particular candidate, but amygdala activation can also be caused by arousal and positive emotions. Overall, the fmri has its uses, but must be qualified by what it actually observes and measures, which is localized brain activity measured indirectly by oxygen content in cranial blood flow and not by measuring any real-time, chemical or electrical neural activity. To infer from fmri more fine-grained neural processes leaps past what the technique can actually do, and must be supplemented by a more granular analysis of brain activity that is often absent in fmri studies. Without that it descends to mere neuro-babble, a philosophical blight that doesn’t need a brain scan to understand. From: Galileo’s Lament and the collapse of the social sciences on scribd

come on class!! the teacher loves it when you ask questions !! try to get engaged, Dr. Michael is very good and he probably is just as nervous as the rest of the class. so please try to tango ;) because it really takes two

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Can fmri detect multiple concussion?????

I, a researcher in the field, estimate that 95% (possibly all in humans) of all published fMRI studies are worthless. The reason is that subject motion creates signal variance that swamps the BOLD signal. Although motion correction algorithms are applied to the data they simply do not work well enough to reduce the motion variance to an insignificant value. Most researchers know this to be true but carry on regardless because their career depends upon doing so. Other researchers are simply ignorant of the artifacts that make this method junk.