Summary
EEG, fMRI and PET reveal brain activity by electrical, blood flow or metabolic signals.
In depth
EEG records electrical activity with millisecond resolution; fMRI measures blood oxygen (BOLD signal) with good spatial resolution; PET uses radiotracers; MEG detects magnetic fields; CT shows structure.
Techniques differ in time and space resolution. fMRI is indirect, measuring blood flow. Combining methods gives better insight.
Common mistake: bright spots on fMRI don't show 'the' area for a function; they show activity changes.
Methods differ in space and time: EEG and MEG (millisecond resolution but poor localisation), fMRI (BOLD, millimetre, a few seconds), PET (tracers, molecular targets such as dopamine receptors or amyloid), CT (structure), structural MRI, diffusion tensor imaging (tracts), and NIRS (portable). Invasive methods include electrocorticography and single-neuron recording. TMS stimulates cortex non-invasively to test causality. Advances include 7-tesla MRI and high-density EEG.
Uses: diagnosing tumours, stroke and dementia, mapping language before surgery, and research on cognition. Cautions: fMRI shows correlates, not mechanisms; colourful blobs require statistical correction (the dead salmon study showed false positives); reverse inference is risky; and small samples hamper reproducibility.
Example: in epilepsy surgery, EEG helps localise where seizures begin.
Frequently asked questions
What is Brain Imaging?
EEG, fMRI and PET reveal brain activity by electrical, blood flow or metabolic signals.
Which area of biology covers Brain Imaging, and how advanced is it?
Brain Imaging is one of the 54 topics in Neuroscience. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Basal Ganglia, Neuropharmacology, Connectomics.
Can you give an example of Brain Imaging?
FMRI showed language areas activate while people speak.
What should I learn before Brain Imaging?
Work through the Beginner topics in Neuroscience first, such as Nervous System, Neuron, Central and Peripheral Nervous Systems, then return to Brain Imaging. Intermediate topics assume the Beginner vocabulary.
What topics are related to Brain Imaging?
The closest topics to Brain Imaging are Basal Ganglia, Neuropharmacology, Connectomics, Neurodegenerative Diseases. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Brain Imaging?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Brain Imaging. To practise the whole of Neuroscience, use the Neuroscience quiz.
How is Brain Imaging different from Basal Ganglia?
Brain Imaging: EEG, fMRI and PET reveal brain activity by electrical, blood flow or metabolic signals. Basal Ganglia: Deep nuclei that select and initiate actions, disrupted in Parkinson's and Huntington's diseases. Read both side by side and note what each one explains.
What is a common mistake about Brain Imaging?
Bright spots on fMRI don't show 'the' area for a function; they show activity changes.
How should I study Brain Imaging step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Basal Ganglia and explain the difference aloud. Finally, take the Neuroscience quiz and come back to this page for any question you miss.