Biopsychology: Ways of studying the brain

Question 1

What is the purpose of scanning in psychological research?

Answer 1

To investigate localisation - to determine which parts of the brain do what

Question 2

What are the 4 ways of studying the brain?

Answer 2

1. fMRI
2. EEG
3. ERP
4. Post-mortem examination

Question 3

Post-mortem examination

Answer 3

• Analysis of a person’s brain following their death
• normally used for people with rare disorders & unusual deficits in cognitive processes or behaviour during their lifetime
• Areas of damage in brain are examined after death as it can establish likely cause of the affliction the person experienced
• may also involve comparison with a neurotypical brain to see extent of difference

Question 4

fMRI

Answer 4

• detects changes in blood flow that occurs as a result of neural (brain) activity
• active brain area consumes more oxygen= blood flow directed to active area
• produces 3D images showing which parts of the brain are involved in particular mental process
• has important implications for our understanding of localisation of function

Question 5

EEG

Answer 5

• measures electrical activity within the brain
• does this using electrodes that are fixed to an individual’s scalp using a skull cap
• scan recording shows brainwave patterns
• provides an overall account of brain activity
• may indicate neurological abnormalities such as epilepsy

Question 6

ERP

Answer 6

• uses same equipment & technique as EEG
• BUT presents a stimulus many times
• creates smooth curve of activation by combing the data (process called statistical averaging)
• removes background electrical noise unrelated to stimulus

Question 7

Strength and Limitation of fMRI

Answer 7

Strength: Can safely provide a clear picture of brain activity

• does not rely on use of radiation (virtually risk-free)
• straightforward to use
• produces images with high spatial resolution (lots of detail)
• provides a clear picture of how brain activity is localised

Limitation: May not truly represent moment-to-moment brain activity

• expensive compared to others
• poor temporal resolution (5-second time lag behind the image on screen and initial firing of neuronal activity)

Question 8

Strength and Limitation of EEG

Answer 8

Strength: Is useful in the real-world

• useful in studying stages of sleep & diagnosis of conditions such as epilepsy
• extremely high temporal resolution

Limitation: Hard to distinguish exact location of neural activity

• EEG signal is not useful for pinpointing exact source of neural activity
• does not allow researchers to distinguish between activities originating in different but adjacent locations

Question 9

Strength and Limitation of ERP

Answer 9

Strength
- bring more specificity to the measurement of neural processes that could never be achieved using raw EEG data
- excellent temporal resolution
- frequently used to measure cognitive functions and deficits (e.g. maintenance of working memory)

Limitation
- lack of standardisation in ERP methodology
- so makes it difficult to confirm findings
- background ‘noise’ and extraneous materials must be completely eliminated for pure ERP datA (which may not always be easy to achieve)

Question 10

Strength and Limitation of Post-mortem examinations

Answer 10

Strength: Provide useful information

• evidence was vital in providing a foundation for early understanding of key processes in the brain
• Paul Broca & Karl Wernick relied on post-mortem studies
• also used to study HM’s brain to identify areas of damage, which could then be associated with his memory deficits

Limitation: Usefulness of post-mortem studies in psychological research is challenged

• Causation as damage may be linked to unrelated trauma or decay instead of deficits
• ethical issues of consent are raised as participants may have not provide informed consent when alive (e.g. case of HM)