Lesson 9: Studying the brain Flashcards

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1
Q

What are the 4 ways of studying the brain
(Hint: PEEF)

A

1) Post-mortem examinations
2) Functional magnetic resonance imaging (fMRI)
3) Electroencephalogram (EEG)
4) Event-Related potentials (ERP)

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2
Q

What is a post-mortem examination?

A

when researchers study the BRAIN of a person who displayed a particular behaviour while they were alive

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3
Q

Why are post-mortem examinations important?

A

it has allowed links between BRAIN ABNORMALITIES and psychiatric disorders to be established

e.g reduced level of GLIAL CELLS in the FRONTAL LOBE of patients with depression

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4
Q

State a POSITIVE EVALUATION of post-mortem examinations
(hint: detailed examination)

A

Post-mortem studies have allowed for a more DETAILED examination of ANATOMICAL and NEUROCHEMICAL aspects of the brain that would NOT be possible with other methods of studying the brain

-> enabled researchers to examine deeper regions e.g hypothalamus + hippocampus

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5
Q

State a NEGATIVE evaluation of post-mortem examinations
(hint: validity+ circumstance of death)

A

Post-mortems may lack VALIDITY as people die in a variety of CIRCUMSTANCES and at varying stages of DISEASE.

Similarly, the length of time between DEATH + POST-MORTEM, and drug trearments can all affect the brain

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6
Q

State a NEGATIVE evaluation of post-mortem examinations
(Hint: small sample sizes)

A
  • Post-Mortem studies have very SMALLsample sizes (as special permission needs
    to be granted).

This means the sample cannot be said to be representative of the TARGET population and so it is PROBLEMATIC to generalise the findings to the wider population

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7
Q

What is fMRI

A

It’s a NEUROIMAGING technique that provides an INDIRECT measure of NEURAL activity

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8
Q

How does fMRI work?

A

uses MAGNETIC fields and RADIO waves to monitor BLOOD flow in the brain

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9
Q

What does fMRI measure?

A

measures the change in the ENERGY released by HAEMOGLOBIN + it does this by REFLECTING activity of the BRAIN (oxygen consumption) to give a moving picture of the brain

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10
Q

State a POSITIVE evaluation of fMRI
(hint: brain activity)

A

+ fMRIs captures dynamic brain ACTIVITY as opposed to a post-mortem examination which purely show the PHYSIOLOGY of the brain.

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11
Q

State a POSITIVE evaluation of fMRI
(hint: spatial resolution)

A

+ fMRIs have good spatial resolution (refers to the smallest feature that a measurement can detect).

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12
Q

State a NEGATIVE evaluation of fMRI
(hint: temporal resolution)

A
  • Interpretation of fMRI is complex and is AFFECTED by poor TEMPORAL resolution (resolution of a measurement with respect to time), BIASED interpretation, and by the base line task used
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13
Q

State a NEGATIVE evaluation of fMRI
(Hint: expense + sample size)

A
  • fMRI research is EXPENSIVE leading to REDUCED sample sizes which negatively impact the VALIDITY of the research
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14
Q

What does an electroencephalogram (EEG) do?

A

DIRECTLY measures GENERAL NEURAL activity in the brain, usually linked to states such as sleep and arousal.

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15
Q

How doe EEGs work?

A

Electrodes are placed on the SCALP and detect NEURONAL activity directly below where they are placed

(differing numbers of electrodes can be used depending on focus of the research.)

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16
Q

What are EEG patterns?

A

When electrical signals from the different electrodes are GRAPHED over a period of time

17
Q

What do EEG patterns of patients with epilepsy show

A

SPIKES of electrical activity

18
Q

What do EEG patterns of those with brain injury show?

A

a SLOWING of electrical activity.

19
Q

State a POSITIVE evaluation of EEG
(Hint: clinical diagnosis)

A

EEG is USEFUL in clinical diagnosis-> can be used to record NEURAL ACTIVITY associated with epilepsy so that doctors can confirm the person is EXPERIENCING seizures

20
Q

State a POSITIVE evaluation of EEG
(Hint: cost)

A

+ EEGs are CHEAPER than an fMRI so can be used more widely in research.

21
Q

State a NEGATIVE evaluation of EEG
(Hint: spatial resolution)

A

EEGs have a POOR spatial resolution (refers to the smallest feature that a measurement can detect)

22
Q

What are event-related potentials? (ERP)

A

patterns of NEURAL brain activity that are recorded through EEG in response to a SPECIFIC event or stimuli

23
Q

How do ERPs work?

A

Electrodes are placed on the scalp and DIRECTLY measure neural activity (below where they are placed) in response to a SPECIFIC stimulus introduced by the researcher.

24
Q

How are event-related potentials measured if it is difficult to distinguish all the other electrical activity being generated within the brain?

A

1) To establish a SPECIFIC response to a target stimulus it requires many TRIALS of the same experimental STIMULUS

2) RESPONSES are then AVERAGED together and any INCONSISTENT neural activity is NOT related to that specific stimuli

25
Q

State a POSITIVE evaluation of ERPs
(hint: processing of a stimulus)

A

+ ERPs can measure the processing of a stimulus even in the absence of a behavioural response. Therefore it is possible to measure ‘covertly’ the processing of a stimulus.

26
Q

State a POSITIVE evaluation of ERPs
(hint: cheaper)

A

+ ERPs are cheaper than an fMRI so can be used more widely in research.

27
Q

State a POSITIVE evaluation of ERPs
(hint: temporal resolution)

A

+ ERPs have good temporal resolution (unlike fMRIs).

28
Q

State a NEGATIVE evaluation of ERPs
(hint: spatial resolution)

A
  • ERPs have poor spatial resolution (unlike fMRIs).