biopsychology: ways of investigating the brain Flashcards
(22 cards)
What is cognitive neuroscience?
The scientific study of the influence of brain structures on mental processes
Emerged in the early 1860s
Define brain imaging techniques.
Techniques that allow doctors and researchers to view activity or problems within the human brain
Examples include MRI, fMRI, PET, CAT
state the 4 scanning techniques
- fMRI
- EEG
- ERP
- post-mortem exam
What is fMRI used for?
To measure brain activity while a person is performing a task > This enables researchers to detect which regions of the brain are rich in oxygen and thus are active
What does fMRI produce?
3D images (activation maps) showing which parts of the brain are involved in a particular mental process
What is the function of EEG?
Used to measure and find problems related to electrical activity of the brain > Tracks and records brain wave patterns using electrodes placed on the scalp
different number of electrodes can be used depending on the research
What can EEG detect?
Problems in the electrical activity of the brain that may be associated with certain brain disorders
What are Event-Related Potentials (ERP)?
Brainwaves triggered by particular events, measured using electrodes attached to the scalp > Involves presenting a stimulus multiples times and averaging responses over many trials
What is the purpose of averaging in ERP studies?
To separate event-related potentials from background EEG data
What cognitive processes are linked to ERPs?
- Attention
- Memory
What are post-mortem examinations used for?
To analyze the brain after death to link certain behaviors during a patient’s lifetime to abnormalities in the brain
Who are post-mortem examinations often conducted on?
Individuals who had a rare disorder to establish the likely cause of the disease
define temporal resolution
a measurement with respect to time
define spatial resolution
the size of the smallest object that can be detected in an image
AO3: fMRI weakness
Do not provide a direct measure of neural activity. fMRI scans simply measure changes in blood flow.
WEAKNESS as it is impossible to infer causation. While any change in blood flow may indicate activity within a
certain brain area, psychologists are unable to
conclude whether this brain region is associated with a particular function
AO3: fMRI strength
-
Good spatial resolution
fMRI scans have a spatial resolution of approximately 1-2 mm which is significantly greater than the other techniques (EEG, ERP, etc.). Psychologists can determine the activity of different brain regions with greater accuracy. - Is non-invasive
Unlike other scanning techniques, fMRI does not use
radiation or involve inserting instruments directly into the brain, and is therefore virtually risk-free. This should allow more patients to undertake fMRI scans which could help psychologists to gather further
data on the functioning human brain
AO3: EEG weakness
Electrical activity is often detected in several regions of the brain simultaneously. Consequently, it can be difficult pinpoint the exact area/region of activity, making it difficult for researchers to draw accurate conclusions.
AO3: EEG strengths
Real life application: EEGs are important in the diagnosis of conditions such as epilepsy, a disorder characterised by random burst of activity in the brain that can be easily detected.
It has good temporal resolution: it takes readings every millisecond, meaning it can record the brain’s activity in real time. This leads to an** accurate measurement of electrical activity** when undertaking a specific task.
AO3: ERP weaknesses
- ERPs have poor spatial resolution.
ERPs only detect the activity in superficial regions
of the brain. Consequently, ERPs are unable to provide information on what is happening in the deeper regions of the brain (such as the hypothalamus), making this technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm. - ERP is uncomfortable for the participant, as electrodes are attached to the scalp.
This could result in unrepresentative readings as the patient’s discomfort may be affecting cognitive responses to situations
AO3: ERP strengths
- ERPs takes readings every millisecond, meaning it can record the brain’s activity in real time as opposed to looking at a passive brain. This suggests they have excellent temporal resolution. This leads to an accurate measurement of electrical activity when undertaking a specific task.
- non-invasive. Unlike other scanning techniques, such as (PET), ERP do not use radiation or involve inserting instruments directly into the brain and are therefore virtually risk-free.
- ERPs enable the determination of how processing is affected by a specific experimental manipulation. This makes ERP use a more experimentally robust method as it can eliminate extraneous neutral activity, something that other scanning techniques (and EEG) may struggle to do.
AO3: post-mortem weaknesses
- There is an issue of causation. The deficit a patient displays during their lifetime (e.g. an inability to
speak) may not be linked to the deficits found in
the brain (e.g. a damaged Broca’s area). The deficits
reported could have been the result of another
illness, and therefore psychologists are unable to
conclude that the deficit is caused by the damage
found in the brain - There are ethical issues, patients may not be able to provide informed consent.
AO3: post-mortem strengths
- Helped the understanding of key processes in the brain. Both Broca and Wernicke relied on PM studies in establishing links between language, brain, and behaviour. PM studies improve medical knowledge and help generate hypotheses for further study.
- Can access areas like the hypothalamus and
hippocampus, which other scanning techniques
cannot, and therefore provide researchers with an
insight into these deeper brain regions, which often provide a useful basis for further research.
