Lecture 3 - Brain Scans

How does Spatial resolution relate to brain scans

relates to location during a scan

How does Temporal resolution relate to brain scans

relates to time during a scan

How does poor resolution limit use of spatial resolution

when poor, can’t tell where in brain/which neurons firing

How does poor resolution limit use of temporal resolution

when poor, can’t tell when/how quickly firing, might miss things that happen faster than tech has time to detect.

what is measured with EEG brain scans

Electrical activity in brain via electrodes on scalp, identifies epilepsy, measured in microvolts

How does an MRI operate

magnetic field forces protons in body to line up, pulses of radio into field bounces protons around,, they emit a signal while returning to normal spot, decoded into map, like X ray of soft tissues.

what information does MRI scans provide from the brain

detects brain disease, tumors and anatomical differences

MRIs have great

Spatial Resolution

How does an fMRI operate

Same as MRI with different analysis/results

what information does fMRI scans provide from the brain

shows BOLD signals. shows that more active neurons recruit more blood, fMRI measures blood flow, looks at difference between CONTROL/EXPERIMENTAL scan to tell which areas….. One scan will tell you nothing

What does BOLD stand for

Blood Oxygen Level Dependent

Why is the difference map important for indentifying the function of brain areas

Color variations on the map show statistically different areas between conditions, map would be different if “experimental” condition was applied, must be in the same location to scan 2x and compare it, otherwise no good /not same brain slice

What is the relationship between the colors drawn on a fMRI scan result and brain activation?

Colors show strongest “responses”or greatest significant differences of activity. blue/green = normal blood flow while red/black = bad

Explain some of the limitations about brain scanning techniques

Does NOT tell HOW brain works, does tell WHERE and sometimes WHEN, but NOT exactly the place.

Explain some of the misconceptions about brain scanning techniques

Misconception is that brain scans demonstrate a physiological basis to things that were thought to be emotionally/cognitively based (we know this from independent brain scan data)

Discuss some misconceptions about brain scans that you may hear in popular press

Science uncover’s apes’ hidden soul. Sex: it’s all in the mind. Pain: is it all in your head?