Ways To Study The Brains Flashcards
What are the 2 key concepts
Temporal resolution and spatial resolution
What is temporal resolution
the accuracy of the scanner in relation of time: or how quickly the scanner can detect changes in brain activity
What is spatial resolution
the smallest feature (or measurement) that a scanner can detect, and is an important feature of brain scanning techniques
What is fMRI
It’s a machine that produces 3d images that show which parts of the brain are using larger amounts of oxygen and are therefore more active
How does fMRI work
It detects the changes in blood oxygenation and flow that occurs as a result of neural (brain) activity in specific parts of the brain.
How can you tell that a brain area is more active in an fMRI
More oxygen is consumed and shown
How are dynamic 3d maps of the brain shown in an fMRI
Deoxygenated haemoglobin has a different magnetic quality from oxygenated haemoglobin. An fMRI can detect these different magnetic qualities
What is the temporal resolution of fmris
1-4 seconds after it occurs
What is the spatial resolution of fmris
1-2mm
What re 3 strengths of an fmri
.dont rely on the use of radiation so its safer
.risk free, non invasive and straightforward
.good spatial resolution therefore very detailed
What are 4 weaknesses of fmris
.expensive
.can only capture a clear image if person stays still
.poor temporal resolution so there can be a lag
.only measures blood flowing and not neurons so the type of brain activity can’t be presented
What is an EEG
Machine which measure electrical activity within the brain via electrodes that are fixed on the scalp, usually using a skull cap
What does the EEG scan recording show
Brainwave patterns that’s are generated from the actions of millions of neurons
What are the 4 types of EEG patterns
alpha, beta, theta and delta waves
Why do clinicians tend to use EEGs
Because they pick up on unusual arrhythmic patterns which may indicate neurological abnormalities such as epilepsy, tumours, or sleep disorders
What are the 2 distinctive states of EEG patterns
Synchronised and desynchronised
What is a synchronised pattern
Recognisable waveform
What is a desynchronised pattern
Where there is no pattern
What does amplitude and frequency show
The intensity of the activity and the speed or quantity of the activity
What are 3 strengths of an EEG
.important in diagnosis of several conditions such as epilepsy
.contributed in understanding sleep stages
.extremely high temporal resolution and can detect brain activity at a resolution of one ms
What are 2 weaknesses of EEGs
.produces very generalised information so its not useful for finding source of neural activity
.can’t distinguish between activity originating in different but adjacent locations of the brain
What are ERPs
a way of teasing out and isolating specific neural responses associated with sensory, cognitive, and motor events with equipment similar to EEGs
How does an ERP work
A stimulus is presented to a participant (for example a picture/sound) and the researcher looks for
activity related to that stimulus
What is the temporal resolution of a EEG and ERP
Every millisecond
What is the spatial resolution of a EEG and ERP
Activity only detected in superficial and general areas of the brain
What are 3 strengths of ERPs
● ERPs bring much more specificity to the measurement of neural processes than could be
achieved using raw EEG data.
● The excellent temporal resolution of ERPs have led to their widespread use in the measurement
of cognitive functions and deficits.
● Researchers have been able to identify many different types of ERP and describe the precise
role of these in cognitive functioning including parts of working memory.
What are the 2 limitations of ERPs
.it is harder to do properly as all background noise and extraneous material need to b eliminated in order to establish pure data
.lack o standardisation therefore harder to confirm findings
What is post-mortem examination
Analysing a persons brain after their death to identify causes of afflictions and any unusual details which could identify causes of certain living behaviours
What did Iverson find in the brans of schizophrenic patients
High conc of dopamine especially in the limbic system
What are the 3 strengths of post-mortem analysis
. evidence was vital in providing a foundation for early understanding of key processes in the brain.
.Both Broca and Wernicke relied on PM studies in establishing links between language, brain, and behaviour decades before neuroimaging began.
.improve medical knowledge and help generate hypotheses for further study.
What are the weaknesses of post mortem analysis
● Causation is an issue: Observed damage to the brain may not be linked to the deficits under review but to some
other unrelated trauma or decay.
● PM studies raise ethical issues of consent from the patient before death.
