L10 neuroimaging techniques

Question 1

Explain the use of an EEG

Answer 1

Measures the electrial activation (post synaptic potentials) of large groups of synchronously activated neurons

(Neurons communicate via electrical signals)

Question 2

Explain the two types of EEG caps

Answer 2

Traditional (swimming cap)

• electrodes on cap
• requires abrasion to scalp
• e;ectrolyte gel for good contact to the scalp and electrodes
• less sensitive to noise

Geodesic sensor net

• electrodes embeded in sponges inside elasticated net
• electrolyte solution soaked by sponges
• no abrasion only adjustment and addition of water
• more noise sensitive
• for children mostly

Dont work well when lots of hair

Question 3

What is analysed during an EEG

Answer 3

Frequency bands, different frequency bands serve different functions

Question 4

Advantages of EEG

Answer 4

Non invasive
Cheaper than FMRI
High temporal resolution
Quiet

Question 5

Disadvantages of EEG

Answer 5

Sensitive to artefacts
Poor spatial resolution
Hard to determine the source of observed electrical activation
Not a unique neuroimaging technique

Question 6

What is an ERP used for?

Answer 6

Along side the EEG
It averages the neural responses to a certain stimulus
This removes the background information/activation through multiple trials and averaging the neural response

Question 7

Explain what MEG is

Answer 7

Measures the magnetic field generated by neural activation

Question 8

Advantages and disadvantages of MEG

Answer 8

Advanatge
-better spatial resolution than EEG

Disadvantage
Expensive
Can measure deeper sources
Not portable due to size

Question 9

Explain neuromuscular coupling

Answer 9

Neural activation in increased demand for oxygenated blood
Results in the haemodynamic responce
Used oxygenated blood which means less is present

Question 10

Explain what a PET scan is

Answer 10

Detects radiation given off by injected radiotracer

Question 11

PET disadvantages

Answer 11

Costly

Invasive

Question 12

When are PET scans used?

Answer 12

Not often due to price

Medical scans eg alzeimer disease

Question 13

Explain MRI

Answer 13

Big magnet
Studies the brains anatomy
Energy of moving atoms from radio frequency pulse being applied and turned off.
Computer used maths formula to convert signal to image

Question 14

What does fmri do

Answer 14

Studies brains function

Question 15

Resolution fo fmri and mri

Answer 15

Mri is high resolution
(1mm)

Fmri is low(3mm)

Question 16

Explains the fmris subtraction method

Answer 16

Initial condition of holding an object
Then test consition of manipulating the object
And ssubtract the associated with manipulated object

Question 17

Fmris advantages and disadvanatges

Answer 17

Pros
Non invasive
High spatial res

Cons
Spenny
Poor temporal res
Noisy
Sensitive to movement

Question 18

Is a mri safe?

Answer 18

Yes

Question 19

What is an fnir

Answer 19

Optical technique measuring heomodynamic neuronal activaiton

Changes o2 blood to no 02 blood
The blood in brain is measured by detecting changes in absorption of near infrered light

Question 20

Fnir pro and con

Answer 20

Pro
Non invasive
High spatial res
Allows for movement

Disadvanatges
Poor temporal res
Not as good as an eeg- only see what occurs within a small window

Question 21

What is tms

Answer 21

Helps draw causal inferences about function of brain areas

Magnetic pulse indcues electrical activation in brain
Can have inhibitory or excititory effects

Can inc or dec brain activatoin of apreas and impact catagoriseation