Ways of Investigating the Brain (Biopsychology) Flashcards
fMRI scans
- Detects blood flow in the brain
- More active areas of the brain need more blood
- These activation areas can bbe compared with a lower blood supply and displayed on an fMRI image
3 Strengths of fMRI scans
- fMRI has good spatial resolution of approximately 1mm
- Non-invasive and virtually risk free
- Therefore has good ethical validity
3 Weaknesses of fMRI scans
- Poor temporal resolution as images are taken every few seconds
- Expensive to build and operate
- Participant needs to be still for the scan to work
Electroencephalogram (EEG) and uses
The use of an EEG involves the placing of electrodes on the scalp along with a conductive gel which record brain activity
The electrodes measure the activity of the cells directly below them
Brain activity is shown via brain waves
The amplitude shows the brain intensity and the frequency shows the speed of activation
this indicates the nature of the brain activity
EEGs may be used to investigate sleep disorders, seizures, memory problems
The Lobes of the Brain
• frontal
• temporal
• parietal
• occipital
Brain wave types
• Alpha
• Beta
• Delta
• Theta
3 Strengths of Electroencephalogram (EEG)
- Invaluable in the diagnosis of conditions such as epilepsy.
- Cheaper than alternatives like fMRI
- Extremely high temporal accuracy can measure brain activation measured in milliseconds
2 Weaknesses of Electroencephalogram
- Poor spatial activity as pattern is sum of a large number of neurons
- EEG can’t give insight into deeper regions of the brain such as the amygdala
Event-related potentials (ERPs)
- Use the same technique and equipment as EEG
- ERPs record when there is activity in response to a stimulus
- The EEG’s waveform peaks and dips show exactly when cognitive processes happen after the stimulus is presented
Strengths of Event-related Potentials
- Excellent temporal resolution with a millisecond sampling rate
- Cheaper than fMRI scanning
->more readily and widely available
2 Weaknesses of Event-related Potentials
- Poor spatial resolution
- Participants may find wearing the electrode cap very uncomfortable
->lead to scratching and alter validity of findings
Post mortem examinations
Involves removing the brain, preserving it, splicing it and observing where there was damage, activity etc
Brown et al. (1986) discovered that patients who have schizophrenia had enlarged ventricles in their brains through his patient ‘Tan’
2 Strengths of Post-mortem examinations
- Enables researchers to study a brain without inflicting any harm on the living person
- Helps clinicians cofirm a diagnosis
2 Weakness of Post-mortem examinations
- PM is not conducted on living brain, unusual behaviour in life and damage found is correlational
- Not always possible for patient to give informed consent
