Biopsychology- Ways of studying the brain- TB Flashcards
How many ways of studying the brain are there?
4
What are the 4 ways to study the brain?
1) Post-mortem examination
2) Scanning techniques- Functional magnetic resonance imaging (fMRI)
3) Electroencephalograms
4)Event related potentials
What is a post-mortem examination?
A study of the brain done after an individual has died if it is suspected that their behaviour was caused by brain damage
What 2 things does a post-mortem examination allow?
1) Make it possible to identify brain structures involved in memory
2) Establish a link between psychiatric disorders & underlying brain abnormalities
What happens in a MRI?
Measures changes in blood flow & oxygen, indicating increased neural activity in specific areas whilst the person is actually performing the task
What are MRI’s useful for?
Identifying which areas of the brain are involved in particular mental activities
What happens in electroencephalograms?
Measures electric activity in the brain using electrodes on scalp, showing brainwaves over time
What are 2 examples of the use of electroencephalograms?
1) Individuals with epilepsy show spikes of electrical activity
2) Alzheimer patients show slowing of electrical activity in the brain
What happens in ‘event related potentials’?
Takes raw electroencephalogram data & averages multiple readings (repeated task) to investigate the cognitive processing of a specific event. It measures very small voltage changes triggered by specific stimuli/ cognitive activity
When do ‘Sensory ERP’s’ occur?
Within the first 100ms after stimulus presentation
When do ‘Cognitive ERP’s’ occur?
After first 100ms of stimulus presentation
What can be revealed in a post-mortem exam that can’t when the person is alive?
Underlying neurology of a behaviour
What are Broca’s findings?
Her patient (speech problems) was found to have a lesion (damage) of Broca’s area of brain- important for speech production
What is used to measure electrical charges using an EEG?
Electrodes on scalp
What are the 4 basic EEG patters?
1) Alpha waves
2) Beta waves
3) Delta waves
4) Theta waves
How do ERP’s establish a specific response?
Many presentations of stimulus & responses are averaged together & unrelated date is filtered out
What are 2 strengths of fMRI as a way of studying the brain?
1) Non-invasive- doesn’t expose brain to radiation
2) Objective & reliable measure compared to verbal reports
What are 2 limitations of fMRI as a way of studying the brain?
1) Not a direct measure of neural activity
2) Overlooks networked nature of brain activity
What are 2 strengths of electroencephalograms as a way of studying the brain?
1) Recording of brain activity in real time
2) Useful in clinical diagnosis e.g. abnormal neural activity in epilepsy
What are 2 limitations of electroencephalograms as a way of studying the brain?
1) Doesn’t reveal deeper regions e.g. hypothalamus (would be too invasive-ethics)
2) EEG signal not useful for pinpointing exact location of activity
What are 2 strengths of ERP’s as a way of studying the brain?
1) Continuous measure of processing in response to a stimulus- can determine how it is affected by specific experiment manipulation
2) Measure processing of stimuli in absence of a behavioural response
What are 2 limitations of ERP’s as a way of studying the brain?
1) Large no. of trials needed- limitation on type of questions ERP’s can answer
2) Deep, important brain activities not recorded e.g. hypothalamus
What are 2 strengths of post-mortem examinations as a way of studying the brain?
1) More detailed explanation of anatomical & neurochemical aspects of the brain than would be with non-invasive scans
2) Played a centre part (Harrison 2000) in understanding of schizophrenia origin
