S1 Wk 10 - Methods and techniques in Biological Psychology Flashcards
what is electroencephalogram (EEG)
records post-synaptic voltage changes
pyramidal cells transmits electrical activity to the scalp
EEG frequency bands - 5
Gamma
Beta
Alpha
Theta
Delta
Clinical applications of EEG
Epilepsy
Sleep - used to characterise sleep stages
linked with sensory and cognitive processing
Sleep EEG polysomnography steps
narcolepsy - sudden falling asleep
sleep apnoea - breathing stops during sleep
insomnia - difficulty falling asleep / staying asleep
parasomnia - terrors; nightmares; Sleepwalking / paralysis
advantages of EEG
Excellent temporal resolution (milliseconds) > ‘online’ functioning
Distinguish timing of different processes (sensory > cognitive)
Low cost
Mobile - but with limitations
disadvantages of EEG
Poor spatial resolutions
Numbers of individual trials needed for averaging (40+ pp x condition)
Fatigue and boredom
Movement artefacts
what does Positron emission tomography (PET) do
involves injection of a radioactive tracer
can look at glucose metabolism
what does magnetic resonance imaging (MRI) do
can examine any part of the body
detailed images of inside body
what does Function magnetic resonance imaging (fMRI) do
looking at a hemodynamic response
evaluates blood flow in the brain called the blood oxygenation level dependent (BOLD) contrast technique
PET pros
Widely used in oncology (diagnosis, staging and treatment)
Distinguish areas of hypometabolism / AB deposition in the brain (e.g., AD)
Identify areas of activity with cognitive processes
Examination of neurotransmitter systems
- Dopamine, serotonin and opioid receptors (ligand
binding to receptors)
PET cons
Radiotracer is radioactive (109 minutes half-life)
- Unable to be used in some populations (e.g.,
during pregnancy)
High cost:
- Creation of isotopes and ligands
- Medical team / environment needed
MRI pros
Excellent spatial resolution
Calculation of GM and WM volumes; correlations with cognitive functions
Non-invasive and does not involve radiotracers
MRI cons
Only informs on structure, not function
Lengthy scanning time (40-60) minutes
Expensive
Not suitable for young children, people with claustrophobia, pacemakers, metal implants etc.
Due to noise, bore (60cm), magnetisation of metal objects
fMRI pro and con
excellent spatial resolution
poor temporal resolution
research applications ERP
cognitive and neural development
