Biopsychology-What are the ways of studying the brain?

Question 1

What is spatial resolution?

Answer 1

Level of accuracy in identifying the exact location of a brain structure or brain activity in space (where the activity happened)

Question 2

What is temporal resolution?

Answer 2

Level of accuracy in identifying the exact location of a brain activity in time (when the activity happened)

Question 3

What are the different ways of studying the brain?

Answer 3

Invasive methods and non-invasive methods

Question 4

What is an invasive method?

Answer 4

When body is ‘invaded’ or entered by a needle, tube, device or scope

Question 5

What is an example of an invasive method?

Answer 5

Post Mortem Dissection

Question 6

What is Post Mortem Dissection?

Answer 6

• Examination of a corpse’s brain to determine cause of death
• Unusual brains are dissected such as brains that suffered trauma, or from individuals with mental illnesses- these brains compared with neurotypical

Question 7

What has post mortem dissection led to?

Answer 7

Broca’s area- responsible for language production was discovered using post-mortem on patient called Tan, who could only say Tan; damage in area of frontal lobe was found after Tan’s death

Question 8

What are the advantages of post-mortem dissection?

Answer 8

-The high spatial resolution of post-mortem allows study of microscopic brain structures down to neuronal
level
-Post-mortem techniques have been significant e.g. discovery of language centres and Broca’s area

Question 9

What are the disadvantages of post-mortem dissection?

Answer 9

• As post-mortem is not conducted on living brain, unusual behaviour in life and damage is correlation (so cannot establish cause + effect)
• Lack validity due to small sample size/individual patients

Question 10

What are non-invasive methods?

Answer 10

Methods of scanning the brain that do not involve penetration of skin or entering the body

Question 11

What examples are there of non-invasive methods?

Answer 11

FMRI, EEG, ERP

Question 12

What does FMRI do?

Answer 12

• Detects blood flow in the brain
• As more active areas of brain need more blood, these active areas can be compared to low activation areas with lower blood supply and displayed on FMRI image

Question 13

What are the advantages of FMRI?

Answer 13

• Good spatial resolution (1mm); precisely identifying active brain regions and patterns of activation over time
• Safe techniques for participants

Question 14

What are the disadvantages of FMRI?

Answer 14

• Poor temporal resolution as image is taken every few seconds and delay in blood flow after activity
• Expensive to build and to operate- also participants need to be still, experiments with body movements are not possible

Question 15

What is the EEG?

Answer 15

A device which is a collection of between 22-32 electrodes that are attached to a cap and fitted with conductive gel

Question 16

How does the EEG work?

Answer 16

• Read out from each electrode is sum total of activation of brain cortex under electrode- displayed as series of lines showing patterns called brain waves
• Amplitude (size of waves) show brain wave intensity, frequency (distance between each wave) shows speed of activation

Question 17

Advantages of EEG?

Answer 17

• Important in areas such as sleep research and medical diagnosis
• Cheaper than alternatives such as FMRI
• Very good temporal accuracy, measuring brain activation with a resolution measured in milliseconds

Question 18

Disadvantages of EEG?

Answer 18

Poor spatial activity as pattern is sum of large number of neurons in cortex under electrode- also cannot detect activity deep within brain

Question 19

What is the ERP?

Answer 19

• Uses same technique and equipment as EEG, but presents stimulus many times, creating smooth curve of activation by combining data; removes background noise unrelated to stimulus
• Waveform’s peaks and dips show exactly when cognitive processes in brain happen after stimulus is presented

Question 20

Advantages of ERP?

Answer 20

• ERP’s allow researches to isolate and study how individual cognitive processes take place in brain, while EEG’s record general brain activity
• Good temporal resolution with millisecond sampling rate

Question 21

Disadvantages of ERP?

Answer 21

Very poor spatial resolution- some processes cannot be studied by ERP as cannot be presented large number of times with same response