Ways of Studying the Brain Flashcards
(14 cards)
Outline post-mortems as a way of studying the brain.
Post-mortem examinations are carried out on individuals who displayed abnormal behaviour during their lifetime. Upon their death, their brain is physically examined and compared to a neurotypical brain to assess structural damage. Any observed damage is assumed to be responsible for the abnormal behaviour displayed in life.
Example: If a patient had speech production difficulties and had damage to Broca’s area, it could be assumed that Broca’s area is responsible for speech production.
What is a strength of post-mortems as a way of studying the brain?
✅ Informs localisation and hemispheric lateralisation. Post-mortems have helped us understand the localisation of functions in the brain.
Example: Broca’s post-mortem research showed that damage to Broca’s area caused speech production difficulties.
What is a limitation of post-mortems as a way of studying the brain?
❌ Difficulty establishing cause and effect. Confounding variables like natural decay of the brain after death could affect the results. The structural damage found may be unrelated to the abnormal behaviour observed during the patient’s lifetime, as brain decay could have caused the damage post-mortem.
What is another limitation of post-mortems as a way of studying the brain?
❌ Small sample sizes. Post-mortems require informed consent, which can be difficult to obtain from patients with disorders of interest. This reduces the generalizability of findings and questions the credibility of conclusions drawn from post-mortem studies.
What are the three main brain scanning techniques?
fMRI, EEG, ERP
Outline fMRI as a scanning technique.
fMRI examines the structure and function of the brain. It uses a large magnetic field and radio frequency waves to create a 3D image of the brain, showing which areas are most active. It measures blood flow since active neurons require oxygen, leading to more blood flow in those areas.
What is a strength of fMRI as a scanning technique?
✅ High spatial resolution. fMRI produces a 3D image that can locate brain activity within 1mm of its location.
What is a limitation of fMRI as a scanning technique?
❌ Low temporal resolution. fMRI is an indirect measure of brain activity since it measures blood flow, not direct neuron firing.
What is another limitation of fMRI as a scanning technique?
❌ Practical limitations. fMRI requires patients to stay still, which can be difficult for young children or individuals with movement disorders. It is expensive to run, making it difficult to include large sample sizes in studies.
Outline EEGs as a scanning technique.
EEGs measure whether brain wave activity is rhythmic, often used to study general brain activity, such as that during sleep. Electrodes are placed on the scalp to directly measure neural activity in the cortex.
Outline ERPs as a scanning technique.
ERPs measure how quickly cortical brain regions respond to sensory stimuli. Electrodes are placed on the scalp to directly measure neural activity in response to a stimulus.
What is a strength of EEGs and ERPs as scanning techniques?
✅ High temporal resolution. EEGs and ERPs are direct measures of brain activity, allowing them to detect changes within milliseconds.
What is another strength of EEGs and ERPs as scanning techniques?
✅ Cheap and cost-effective. EEGs and ERPs require less technological equipment compared to methods like fMRI.
What is a limitation of EEGs and ERPs as scanning techniques?
❌ Low spatial resolution. EEGs and ERPs measure general brain activity in the outer surface (cortex) of the brain and cannot detect activity in deeper brain regions.
