www.astralcodexten.com/p/consciousness-as-recursive-reflections
1 correction found
fMRI shows the slow-changing anatomy of biological neural networks, and how they change on a timeframe of months and years as a nervous system learns, matures and incurs damage.
This misdescribes fMRI. Standard MRI is used for detailed anatomical images, but fMRI measures short-timescale changes in blood oxygenation/blood flow associated with brain activity.
Full reasoning
This sentence conflates structural MRI with functional MRI (fMRI).
- The NIH explains that ordinary MRI produces detailed anatomical images of internal tissues.
- By contrast, fMRI is specifically used to identify brain areas where blood oxygenation or blood flow changes during cognitive activity.
- These fMRI signals occur on the scale of seconds, not only over "months and years."
So the claim is incorrect in two ways: it attributes anatomical imaging to fMRI, and it describes fMRI as tracking only slow, long-term changes, when fMRI is in fact used to measure relatively rapid functional changes linked to brain activity.
A more accurate version would be: structural MRI shows anatomy, while fMRI measures task-related changes in blood oxygenation/blood flow to infer brain function.
3 sources
- Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging (MRI) is a non-invasive imaging technology that produces three dimensional detailed anatomical images... One kind of specialized MRI is functional Magnetic Resonance Imaging (fMRI.) This is used to observe brain structures and determine which areas of the brain 'activate' (consume more oxygen) during various cognitive tasks.
- Magnetic Resonance Imaging (MRI) | Health
MRI produces three-dimensional, detailed anatomical images... Functional MRI (fMRI) uses the blood's magnetic properties to create real-time images of blood flow to specific areas of the brain. fMRI can pinpoint areas of the brain where blood oxygenation changes, giving insights into brain activity and function.
- Functional MRI (fMRI) of the brain
Functional magnetic resonance imaging (fMRI) measures the small changes in blood flow that occur with brain activity... uses MR imaging to measure the tiny changes in blood flow that take place when a certain part of your brain is working.