Methods Lecture Flashcards
(14 cards)
Examples of non invasive methods of investigating the brain
EEG, MRI, fMRI, CT, PET, fNIRS, optical signals
What does an EEG do?
Records synchronised post-synaptic activity
What does a MEG do?
Measures changes in the magnet field generated by the same neural populations with sensors
What does Fourier transform do?
Decomposes any waveform into its constituent frequencies
What disorder is studies using invasive methods?
Epilepsy
How does an MRI scan work?
Hydrogen protons line up and spin when placed in a strong magnetic field. Energy is applied eliminating longitudinal magnetisation vector. After the radio frequency pulse protons return and an electrical signal is induced through free induction decay
4 structures and functions of the MRI machine?
Magnet - creates the magnetic field
Gradient coils - varies the magnetic field to localise the region to be scanned
RF coils - sends the RF pulse and detects the emitted signal
Shim coils - for correcting inhomogeneities in the magnetic field
What is neurovascular coupling?
Blood flow increases to active brain regions, oxygenated blood to the firing neurons, increases in oxygenated haemoglobin concentration
Differences between oxygenated blood and deoxygenated blood?
Different magnetic properties, oxy does not distort fields, deoxy does
What is transracial magnetic stimulation for?
Excite neuron’s using electromagnetic induction. Electric current travels through brain to trigger action potentials
Two different types of TMS
Single pulse TMS
repetitive TMS
Which two non invasive brain methods can be combined?
EEG and TMS
What is transracial electrical stimulation?
Delivering a weak electric current to the scalp to modulate resting membrane potentials
What are the three different types of TES
Transcranial direct current stimulation
Transcranial alternating current stimulation
Transcranial random noise stimulation
