Biopsychology - Ways Of Investigating the Brain Flashcards
What is functional magnetic resonance imaging (fMRI)?
fMRI detects changes in blood oxygenation and flow that occur due to neural activity in specific brain regions. Active brain areas consume more oxygen, increasing blood flow, which is known as the haemodynamic response. fMRI produces 3D activation maps showing which brain regions are involved in mental processes, aiding localisation of function.
What is one strength of fMRI?
fMRI has high spatial resolution, showing detail by the millimeter, which provides a clear picture of how brain activity is localised. It also avoids the use of radiation, making it virtually risk-free if administered correctly.
What is one weakness of fMRI?
fMRI is expensive compared to other neuroimaging techniques and can only capture a clear image if the person stays perfectly still. Additionally, it has poor temporal resolution, as there is a 5-second lag between neural activity and the image on the screen.
What is an electroencephalogram (EEG)?
EEG measures electrical activity in the brain using electrodes fixed to the scalp. It records brainwave patterns generated by millions of neurons, providing an overall account of brain activity. EEG is used to diagnose conditions such as epilepsy, sleep disorders, and brain tumours by identifying unusual patterns of activity.
What is one strength of EEG?
EEG has high temporal resolution, detecting brain activity at a resolution of a single millisecond. It has proven invaluable in diagnosing conditions like epilepsy and has also contributed to understanding stages of sleep and ultradian rhythms.
What is one weakness of EEG?
The generalised nature of EEG signals means it is not useful for pinpointing the exact source of neural activity. It also cannot distinguish between activities originating in different but adjacent brain regions.
What are event-related potentials (ERPs)?
ERPs are derived from EEG data by filtering out extraneous brain activity to leave only responses related to specific stimuli or tasks. They are brainwave types linked to cognitive processes such as attention and perception, offering insight into these mental functions.
What is one strength of ERPs?
ERPs have high temporal resolution and greater specificity for measuring neural processes than raw EEG data. For example, they have been used to identify the role of the P300 component in attention allocation and decision-making.
What is one weakness of ERPs?
ERPs are criticised for a lack of standardisation in their methodology across studies, making it difficult to confirm findings. Additionally, background noise and extraneous material must be eliminated, which can be challenging.
What are post-mortem examinations?
Post-mortem examinations involve analysing the brain after death, typically of individuals with rare disorders or unusual deficits in mental processes or behaviour. This helps identify areas of damage and link them to observed deficits, often compared to neurotypical brains for further analysis.
What is one strength of post-mortem examinations?
Post-mortem studies have been key in advancing understanding of brain processes. For instance, Broca and Wernicke used them to establish links between specific brain areas and language functions. Such studies help generate hypotheses for further research.
What is one weakness of post-mortem examinations?
Observed damage in the brain may not be linked to deficits experienced during life, as the individual may have suffered unrelated trauma or decay. Additionally, causation cannot be established since post-mortems only offer correlational data.
