measuring brain activity Flashcards
aim of brain imaging
attempting to assess the activity within the brain without being invasive.
EEG strengths
- good temporal resolution (can determine very brief events in time)
- cheap
- portable’- safe and well tolerated by participants
EEG weakness
- has poor spacial resolution, its hard to detect where the signals are coming from in the brain
Electrophysiology
stick a large electrode into the brain,
Electrophysiology - strengths
records directly from individual neurons so is the best method to use for what neurons are doing
Electrophysiology - weakness
high risks of infection as the technique is highly invasive and it penetrates the brain.
MRI
exploits the magnetic properties of the brain tissue.
- generates a very strong magnetic field and works out there are some parts of the brain with different levels of water
DTI
uses the same MRI to detect white matter which flows through the brain to connect different regions of the cortex
fMRI
the increase in the blood flow detects what parts of the brain are in use. cognitive processes require blood, which needs oxygen, so it can detect where the brain uses energy by detecting oxygen.
MRI strengths
very high spatial resolution (identifies what brain areas are being used)
=- valuable tool because it can identify specific structural and functional properties of different brain regions.
MRI limitations
- very expensive
- large equipment
- safety rooms
PET scan
uses radioactive substances as traces visualize glucose metabolism or the neurotransmitter/ receptor function.
- can use to detect Alzheimer’s
strengths of PET scan
- can detect different chemicals in the brain associated with either metabolism (energy consumption), or functional properties such as specific neurotransmitter levels of proteins.
limitations of PET
- expensive and requires specialist facilities and staff
Ablation= ‘to carry away’
the method of surgically removing aspects of the brain to determine the roles of brain parts
