Using fMRI to study cognitive neuroscience Flashcards Preview

Physiology and Neuroscience > Using fMRI to study cognitive neuroscience > Flashcards

Flashcards in Using fMRI to study cognitive neuroscience Deck (24)
Loading flashcards...
1
Q

What can you measure in the brain?

A
Blood flow
Oxygen level
Electrical activity
Magnetic field
Neurotransmitter
2
Q

What is Functional magnetic resonance imaging (fMRI)?

A

A strong magnet detects slight changes in local magnetic fields caused by changes in blood oxygenation
Oxygen level in blood translates how active a brain area is

3
Q

What does active brain tissue use more of?

A

Blood i.e. glucose/O2

I.e. Hemodynamic response (HDR)

4
Q

What does fMRI measure?

A

Blood Oxygenation Level Dependent (BOLD) signal

Changes in deoxygenated and oxygenated haemoglobin ratio

5
Q

What is the difference between deoxygenated and oxygenated haemoglobin?

A

Different magnetic properties

6
Q

What regions do the functional face localiser scan pick up?

A

Occipital face area, fusiform face area, posterior superior temporal sulcus, amygdala, posterior cingulate cortex and medial orbitofrontal cortex, and inferior frontal gyrus

7
Q

What are things to consider when designing an fMRI experiment?

A

Haemodynamic response- astrocytes function as link between synapses and blood vessels
Temporal resolution only sufficient for longer trials

8
Q

What is the fMRI technique?

A

Strong magnet to detect oxygen changes in blood; BOLD signal, haemodynamic response
–> indirect measurement of neuronal activty

9
Q

What are the resolutions for fMRI?

A

Spatial resolution- excellent

Temporal resolution- okay for longer trials or blocks

10
Q

What are the limitations of fMRI?

A

No ferromagnetic objects
Discomfort for larger participants or individuals suffering from claustrophobia
Long scanning time

11
Q

What is Event Related Potentials?

A

Electrodes on scalp surface measure electrical activity generated by neurons

12
Q

What is measured in ERPs?

A

Secondary current from many neurons

We measure the difference between “target” electrode and a neutral “reference” electrode

13
Q

What is the resolution of ERPs?

A

Spatial resolution- okay-poo, depends on number of electrodes used; signal comes from many neurons
Temporal resolution- excellent (ms)

14
Q

What are the limitations of ERPs?

A

Long preparation time and long experiments; many trials needed for averaging
Artefacts caused by movement, eye blinks etc

15
Q

What is magnetoencephalography (MEG)?

A

Measures magnetic field that is generated by neural activity

16
Q

What do magnetic fields on surface of scalp measured by what detectors?

A

Superconducting
Quantum
Interference
Device

17
Q

What technique is measured for MEG?

A

SQUIDs measure the magnetic field on surface of scalp (generated by primary current)

18
Q

What is the resolutions of MEG?

A

Spatial resolution- good, large number of detectors

Temporal resolution- excellent

19
Q

What are the risks/discomforts of MEG?

A

Artefacts caused by movement, ferromagnetic objects etc
Long scanning time
Expensive

20
Q

What can be used to measure blood flow?

A

Transcranial Dopler Sonogrpahy (fTCD)

21
Q

What can be used to measure oxygen level?

A

fMRI

22
Q

What can be used to measure electrical activity?

A

EEG/ERP

23
Q

What can be used to measure magnetic field?

A

MEG

24
Q

What can be used to measure neurotransmitters?

A

Positron Emissions Tomography (PET)