Ways of studying the brain - EEG, ERP, post mortums

Question 1

What does EEG stand for?

Answer 1

electroencephalogram

Question 2

Who developed Electroencephalograms?

Answer 2

Hans Berger in 1929

Question 3

What do Electroencephalograms provide a view of?

Answer 3

the overall brain electrical activity

Question 4

How do electroencephalograms (EEGs) work?

Answer 4

A large number of small recording electrodes (24/32) are distributed over the surface of the skull and these pick up the electrical activity of millions of neurons

Question 5

What are the basic properties of electroencephalograms (EEGs) that are used to characterise brain states?

Answer 5

Amplitude (size or intensity) and frequency (speed or rapidity)

Question 6

What are the two distinctive states of the EEG?

Answer 6

Synchronised pattern and Desynchronised pattern

Question 7

What is a synchronised pattern?

Answer 7

where a recognised waveform can be detected in the EEG recording

Question 8

What is a desynchronised pattern?

Answer 8

where there is no recognisable waveform

Question 9

what can EEG detect?

Answer 9

various types of brain disorder (epilepsy) or other disorders that influence brain disease (alzheimer’s), showing the overall slowing of electrical activity

Question 10

What are the types of waves shown in Electroencephalograms (EEGs)

Answer 10

Beta, Alpha, Theta, Delta

Question 11

What are Electroencephalograms (EEGs) useful for?

Answer 11

the general state of the brain and studying sleep

Question 12

Beta waves (EEG)

Answer 12

15-30Hz

Question 13

Awake, normal alert consciousness

Question 14

Alpha waves (EEG)

Answer 14

9-14Hz

Question 15

Relaxed, calm, meditation, creative visualisation

Question 16

Theta waves (EEG)

Answer 16

4-8Hz

Question 17

Deep relaxation and meditation, problem solving

Question 18

Delta waves (EEG)

Answer 18

Deep, dreamless sleep

Question 19

What are the strengths of Electroencephalograms (EEGs)?

Answer 19

+ Good temporal resolution

Question 20

+ Helped provide invaluable diagnosis (conditions like epilepsy) and understanding sleep stages

Question 21

Why is the fact that EEG’s have good temporal resolution beneficial?

Answer 21

Provides recording of the brains activity in real time rather than a still image. The researcher can accurately measure an activity.

Question 22

What are the weaknesses of Electroencephalograms (EEGs)?

Answer 22

• Only detects activity in superficial regions and not deeper (like hypothalamus or hippocampus)

Question 23

• Poor spatial resolution

Question 24

Why is the fact that EEGs have poor spatial resolution bad?

Answer 24

It isn’t useful for pinpointing the exact source of neural activity so researcher can’t distinguish between activities originating in different but adjacent locations

Question 25

What is the issue with the fact that EEGs don't show activity in deeper regions?

Answer 25

They are also important as for example the hippocampus is really important in helping us maintain our long term memories so it's hard to understand the functioning of LTM's through EEGs

Question 26

What does ERP stand for?

Answer 26

Event related potentials

Question 27

What are ERPs?

Answer 27

Small voltage changes in the brain triggered by specific events or stimuli such as cognitive processing or specific stimuli

Question 28

How do ERPs work?

Answer 28

Electrodes are put on the scalp and they are presented with a sequence of stimuli, the brains electrical impulses are recorded. They are presented with one familiar stimuli (their own name) and four unfamiliar stimuli (random names)

Question 29

Each stimuli is repeated 30 times and the reaction is recorded (in total 150 times)

Question 30

ERPs test if all information presented is recognised by the person is extremely accurate by comparing the average brain waves for four unfamiliar and familiar stimuli

Question 31

What are the strengths of ERPs?

Answer 31

+ can reflect early stages of cognitive processing

Question 32

+ can measure processing of stimuli in the absence of a behavioural response

Question 33

Why can ERP's reflect early stages of cognitive processing?

Answer 33

they have a short latency of response (interval between stimulus presentation and beginning of ERP) in milliseconds

Question 34

What are the weaknesses of ERPs?

Answer 34

- poor spatial resolution

Question 35

- lack of standardisation in ERP methodology

Question 36

Why do ERPs have poor spatial resolution?

Answer 36

Recording electrodes are spread all over the scalp so it is possible to localise components to general cortex areas but not to specific areas

Question 37

Why is the poor spatial resolution of ERP's bad?

Answer 37

Wee can't be sure about what brain areas are responsible for specific behaviours

Question 38

Why is the lack of standardisation of ERPs a weakness?

Answer 38

findings can't be confirmed or generalised. to get correct data extraneous variables must be minimised (like background noise)

Question 39

What is another word for post-mortems?

Answer 39

Autopsies

Question 40

How are post mortems used?

Answer 40

When a person dies the researcher can compare their brain to look for abnormalities that may explain behaviours compared to controls without it

Question 41

How have post mortems proved to be important?

Answer 41

Has contributed to the understanding of many disorders like schizophrenia and allow for detailed examinations of anatomical and neurochemistry aspects of the brain and enable researches to examine deeper regions of the brain (hippocampus and hypothalamus)

Question 42

Iverson

Answer 42

examined brains of dead schizophrenic patients and found that they all have a higher concentration of dopamine especially in the limbic system

Question 43

What are the strengths of post mortems?

Answer 43

+ allow for more detailed examinations of anatomical and neurochemical aspects than fMRIs and EEGs

Question 44

+ Harrison (2002) claims they played a central part in our understanding of origins of schizophrenia and other mental illnesses

Question 45

What are the weaknesses of post mortems?

Answer 45

- too many individual differences in how people die and this can affect the brain

Question 46

- ethical issues like informed consent

Question 47

- limited as its retrospective so follow ups can't be made