Research methods in Neuroscience Flashcards
Methods
Visualising and stimulating
recording psychophysiological activity
invasive methods
pharmacological methods
genetic manipulations
Contrast x-ray techniques
Inject contrast agent, can see intravascular and extravascular compartment
MRI
Radiofrequency waves sent in, some absorbed. Detects how much passes through to build picture. High spatial resolution but just a brain “structure”
Functional MRI (fMRI)
Similar to normal MRI except you ‘tune’ the scanner to be sensitive to something
eg blood because the haemoglobin contains iron. Can detect when oxygen is ‘hiding’ the iron so is good for picking up the oxygenation of blood in the tissue - this is Blood Oxygen Level Dependent (BOLD) fMRI
Activated brain cells call up more oxygenated blood so fMRI can tell us about brain activity.
Positron Emission Tomography (PET)
Contrast agent targeted to biological process being investigated by using a chemical that binds to target.
Attach a radioisotope (radiation emitting molecule) to the chemical (a positron emitter).
Can then detect emitted radiation via computer to see where it is coming from.
Good for informing specific biological processes but spatial and temporal resolution not great.
Radiation used so more limited in research applications.
EEG
regional brain activity underlying electrodes - good temporal resolution but poor spatial resolution.
Good for detecting epilepsy
Analysis complex and takes long time
Signals separated into different frequency bands. These related to distinct neurophysiological processes.
EEG can also be used to see response to specific stimuli
MEG (magnetoencephalography)
Electrical current of large number of cells and white matter induces a magnetic field. Can be detected.
Very small and hard to detect these signals.
Better spatial resolution due to less interference by scalp and skull than electrical signals.
