Ways of Studying the Brain

Question 1

outline the function of fmri scans

Answer 1

• used for measuring changes on brain activity while an individual performs a task

It does this by measuring changes in blood flow to particular areas in the brain
If an area is more active there is more of a demand for oxygen and therefore blood flow is increased
and we learn about the brain regions involved in performance of these tasks

Question 2

EEG

Answer 2

measures electrical activity in the brain through electrodes attached to the scalp

Data can be used to indicate different brain disorders such as epilepsy or alzheimers

Question 3

4 basic EEG patterns

Answer 3

Alpha waves- when a person is awake and relaxed
Beta waves- when a person is physiologically aroused, low amp fast freq waves. Also found in REM sleep.
Delta and theta- occur during sleep.

Question 4

event related potentials

Answer 4

ERPs Small voltage changes in the brain triggered by a specific stimulus. it takes EEG data to investigate cognitive processing of a specific event through averaging multiple readings

Question 5

Issues of causation in fMRIs and EEGs

Inability to show causation.

Answer 5

fMRIs don’t provide a direct measure of neural activity. They simply measure changes in blood flow - impossible to infer causation at neural level.

EEGs often detect electrical activity in several regions of the brain simultaneously. Unable to conclude whether particular brain regions are associated with specific regions (fMRI) and which region the electrical activity took place (EEG) making solid cause effect conclusions impossible.

Question 6

Studying the brain :)- EEGs have good temporal resolution

Answer 6

EEGs, in comparison to fMRI, have good temporal resolution
Temporal resolution refers to the accuracy of the scanner in relation to how quickly the scanner can detect changes in the brain activity.

EEG scanners take readings every millisecond, meaning they can record the brain’s activity in real-time as opposed to fMRI scans have a temporal resolution of 1-4 seconds
Suggests EEGs provide a high degree of accuracy when examining the onset of brain activity, allowing psychologists to make accurate conclusions in relation to the timing neural activity, in comparison to fMRI.

Question 7

limitations of fmri scans- poor temporal resolution

Answer 7

only one image is taken every few seconds so there’s a delay in blood flow activity. many brain processes are too fast to study. thus doesn’t provide a real time picture of brain activity unlike EEGs

Question 8

limitation of EEG

Answer 8

poor spatial accuracy as the pattern is a sum of a large number of neurons in the cortex under electrodes. this means they cannot detect activity deep within the brain which in turn only provides a limited picture of brain activity

Question 9

Studying the brain :)- fMRIs have good spatial resolution

Answer 9

fMRI, in comparison to EEG, is that it has a good spatial resolution.
Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy.
fMRI scans have a spatial resolution of approximately 1-2 mm which is significantly greater than the other techniques.
EEG can only detect the activity in superficial regions of the brain.