ways of studying the brain

Question 1

what is temporal resolution?

Answer 1

-the accuracy of the scanner in relation to time
-how quickly the scanner can detect changes in brain activity

Question 2

what is spatial resolution?

Answer 2

-the smallest feature or measurement that a scanner can detect

Question 3

what does fMRI stand for?

Answer 3

functional MRI/ functional magnetic resonance imaging

Question 4

how does an fMRI work?

Answer 4

-measures blood flow in the brain while a person performs a task
-Neurons in the brain that are the most active use the most energy, which requires glucose and oxygen.
-Oxygen is released for use by these active neurons at which point the haemoglobin becomes deoxygenated.
-Deoxygenated haemoglobin has a different magnetic quality from
oxygenated haemoglobin- an fMRI can detect these different magnetic qualities to create a dynamic 3D map of the brain.

Question 5

what is the end product of an fMRI/ what does it create?

Answer 5

-a dynamic 3D map of the brain

Question 6

what does eeg stand for?

Answer 6

Electroencephalogram

Question 7

how does an EEG work?

Answer 7

-measure electrical activity through electrodes attached to the scalp
-Information is processed in the brain as electrical activity in the form of action potentials or nerve impulses.
-Small electrical charges are detected by the electrodes and graphed over a period of time, indicating the level of activity.

Question 8

How many different types of EEG patterns are there? What are they?

Answer 8

-4
-Alpha, Beta, Theta, Delta

Question 9

what is the end product of an EEG/ what does it create?

Answer 9

-There are 4 types of EEG patterns: alpha, beta, theta and delta waves.
-EEG patterns produce two distinctive states: synchronized patterns (a recognizable waveform such as alpha, beta, delta and gamma) and desynchronized patterns (no pattern).

Question 10

what does ERP stand for?

Answer 10

Event Related Potential

Question 11

how does an ERP work?

Answer 11

-use similar equipment to EEGs (electrodes attached to the scalp)
-a stimulus is presented to a participant (for example a picture or sound) and the researcher looks for activity related to that stimulus.
-‘Averaging’ is used- the stimulus is presented multiple times (usually hundreds), and an average
response is graphed. The time/ interval between the presentation of the stimulus and the response is
referred to as latency.

Question 12

what is the end product of an ERP/ what does it create?

Answer 12

A graph of average responses to the stimulus

Question 13

True or False? For an ERP, a stimulus is presented 3 times and the average is graphed.

Answer 13

False! The stimulus is presented LOADS, maybe even hundreds of times!

Question 14

What are the temporal and spatial resolutions of an ERP?

Answer 14

-Temporal Resolution: EEGs show activity every millisecond, recording activity in nearly real time
-Spatial Resolution: EEGs only detect activity in superficial, general areas of the brain.

Question 15

What are the temporal and spatial resolutions of an EEG?

Answer 15

-Temporal Resolution: EEGs show activity every millisecond, recording activity in nearly real time
-Spatial Resolution: EEGs only detect activity in superficial, general areas of the brain.

Question 16

What are the temporal and spatial resolutions of an fMRI?

Answer 16

-Temporal Resolution: images show activity up to 5 second after it occurs
-Spatial Resolution: thought to be accurate within 1-2mm

Question 17

What is a Post-Mortem?

Answer 17

-Researchers study the physical brain of a person who displayed a particular behaviour while they were alive

Question 18

What are the ways of studying the brain?

Answer 18

-fMRI
-EEG
-ERP
-Post Mortem

Question 19

How many ways are there to study the brain?

Answer 19

4

Question 20

What are the strengths of fMRIs?

Answer 20

-good spatial resolution
-non invasive

Question 21

What are the strengths of EEGs?

Answer 21

-good temporal resolution
-non invasive

Question 22

What are the strengths of ERPs?

Answer 22

-good temporal resolution
-non invasive

Question 23

What are the strengths of Post-Mortems?

Answer 23

-Allow for a more detailed examination of anatomical and neurochemical aspects of the brain than would be possible with other techniques
-Have contributed to our understanding of many disorders, such as Iverson + schizophrenia
-Allow for an understanding of the anatomy of the brain, and even now give us a more detailed examination of anatomical and neurochemical aspects than would be possible with other techniques

Question 24

What are the limitations of fMRIs?

Answer 24

-poor temporal resolution
-cannot show causation

Question 25

What are the limitations of EEGs?

Answer 25

-poor spatial resolution
-inability to show causation

Question 26

What are the limitations of ERPs?

Answer 26

-poor spatial resolution
-inability to show causation

Question 27

What are the limitations of Post-Mortems?

Answer 27

-ethical issues

Question 28

Explain the strength of post-mortems that they have contributed to our understanding of many disorders?

Answer 28

-Iverson examined the brains of deceased schizophrenic patients and found a higher concentration of
dopamine, especially in the limbic system, compared to non-
schizophrenics. This allowed psychologists to understand the
disorder more, and helped develop the treatment of it.
-Broca’s post-mortem study of his patient ‘Tan’, where he found a lesion in the area of the brain now called ‘Broca’s Area’, that he came to understand was responsible for speech-production.
-This is a strength as it shows the value post-mortems have had in understanding howe the brain and particular disorders work.

Question 29

Explain the limitation that they are unable to show cause and effect?

Answer 29

-fMRI scans do not provide a direct measure of neural activity- they
simply measure changes in blood flow; therefore, it is impossible to
infer causation at a neural level.
-EEGs often detect electrical activity in several regions of the brain simultaneously, limiting them.
-This means that psychologists are unable to conclude whether particular brain regions are associated with specific functions (in the case of fMRI) and which area/region the electrical
activity took place (in the case of EEG), making solid cause and effect conclusions impossible.