ways of investigating the brain ao1 Flashcards
Spatial resolution
Smallest feature or measurement scanner can detect
More spatial resolution means psychologists can discriminate between different brain regions with greater accuracy
4 ways to study the brain
fmri
eeg
erp
post mortem examination
Temporal resolution
Accuracy of scanner in relation to time
How quickly can scanner detect changes in brain activity
fMRI
- used to measure changes in brain activity while a task is being performed
- detects changes in oxygenated blood flow whereby increased activity leads to increased need for o2
- produces a 3D image of the active areas in the brain
- shows activity about 1 second after it occurs
- it’s also accurate to within 1-2 mm within the brain
Fmris temporal and spatial res
Bad temporal resolution
Good spatial resolution
What is an EEG
electrodes placed on the scalp and they record the electrical activity of the brain
Electrodes measure the activity of the cells immediately under the electrode
Often used as a diagnostic tool eg for epilepsy and alzheimers
List 4 types of EEG patterns and what do they give us info about
Alpha waves
Beta waves
Theta waves
Delta waves
each pattern indicates different level of activity
2 properties of waves looked at in EEG
Amplitude - intensity or size of activity
Frequency - speed/how many are happening in a given time
ERPS
Very small voltage changes in the brain triggered by specific events
a stimulus is presented many times and the researcher looks for a response
Responses are averaged together
Latency : the time or interval between the presentation of the stimulus and the response
- sensory ERPs occur within 100 ms
- cognitive ERPs occur after 100 ms
Post mortem examinations
Examining brain after person died
Used to see where damage had occurred in the brain and how that might explain behvaiour exhibited by the individual prior to death
Feature of fMRI
Indirectly measuring the electrical activity of neurons by recording changes in brain blood flow
Difference between EEGS and ERPS
ERPS look at the response presented due to stimuli
EEGS don’t include a stimuli just look at brain waves
Fmris detect changes in _______ to produce _______ in about ______ second
Fmris detect changes in blood oxygenation and flow to produce 3D images in about 1 second
In an EEG______ to record _______. There are ______ types of _______. These are called…
In an EEG *electrodes are placed on scalp * to record electrical activity in the brain There are 4 types of waves These are called alpha, beta, theta, delta
_____ is similar to EEGS, but a key difference is ______
It has 2 types of latency measure. The first is ______ and the second is _______
ERPS is similar to EEGS, but a key difference is *a stimulus is presented in ERPS but not EEGS, whereby researcher looks for a response *
It has 2 types of latency measure. The first is *sensory ERPS - within 100 milliseconds * and the second is cogntive ERPS after 100 ms
Post mortem examinations are when ______ They can be used to _____
Such as in the case study of ______
Post mortem examinations are when a person is dead They can be used to see where damage has occured
Such as in the case study of deborgne
Cortical specialisation means
Specific jobs each area of cortex performs
Briefly evaluate the use if EEGs as a way of identifying cortical specialisation in the brain (3)
A limitation is the generalised nature of EEGS as no stimulus is given for researchers to record responses to like in ERPS, information found can be generalised to thousands of neurons. It’s not useful in finding which part of the brain is responsible for the brain activity. So it doesn’t allow researchers to link specific parts of the brain to specific functions or differentiate between activities in adjacent parts if the brain. Reducing its precision and efficiency.
