methods of studying brain structure and function

Question 1

phrenology - historical

Answer 1

bulges and dips on the skull correspond to brain areas and specific behaviours

Question 2

staining techniques

Answer 2

cell body stains - reveals cells in brain tissue
myelin stains - bundles of myelinated nerve fibres
membrane stains - reveals dendrites and there spines

Question 3

histochemical techniques

Answer 3

locate specific neurons and neurotransmitters
- does not tell living brain

Question 4

immunocytochemical techniques

Answer 4

take advantange of normal immune reactions
- does not tell living brain

Question 5

CT/CAT scans

Answer 5

living brain
x-ray passes through head and image is produced
whiter = denser - good for diagnosis on tumours

Question 6

MRI - magnetic resonance imaging

Answer 6

uses magnet to observe radiation from hydrogen atoms which are present in all cells at diff concerntrations

Question 7

FMRI - frontal magnetic resonance imaging

Answer 7

adds to MRI as shows function
measures metabolic activity as active brain areas consume more oxygen

Question 8

PET scan - positron emission tomography

Answer 8

glucose injected into patient and active cells take this up - shows which areas are active and which areas are healthy or in decline

Question 9

advantages of brain imaging

Answer 9

non-invasive
good spatial resolution
can be used to compare

Question 10

disadvantages of brain imaging

Answer 10

risk from xrays and radiation
poor temp resolution
noisy, scary, claustrophobic
expensive in time and money

Question 11

what does measuring electrical activity tell us?

Answer 11

which structures are used for particular functions

Question 12

measuring brain activity with microelectrodes

Answer 12

implanted in brain to monitor activity of neurons
records very precise activity
but highly invasive

Question 13

measuring brain activity with macroelectrodes

Answer 13

EEG - attach to scalp in areas of expected activity and neutral areas
see diff between active and neural electrodes measured

Question 14

EEG waves

Answer 14

beta - actively attending to events and aware
alpha - awake but not processing, relaxed
theta - light sleep
delta - deep sleep

Question 15

advantages of macroelectrodes (EEG)

Answer 15

non-invasive
can differentiate between different conditions and behavioural states

Question 16

disadvantages of macroelectrodes (EEG)

Answer 16

time consuming, labour intensive, lots of equipment needed
requires high levels of experience
averaging does not allow to establish activity in specific region or behaviours

Question 17

experimental brain damage

Answer 17

controlled and localised damage to specific areas
if behaviour changes then damaged area is involved

Question 18

problems with experimental brain damage

Answer 18

ETHICS
brain is interconnected so damage at one site may effect function of another
artificial damage vs natural damage

Question 19

using SNS to measure brain activity

Answer 19

HR and blood pressure

Question 20

using galvanic skin response to measure brain activity

Answer 20

activation of SNS increases sweat levels

Question 21

using endocrine system to measure brain activity

Answer 21

hormones sampled in saliva and blood and urine etc