What are 2 approaches to studying the brain?
- studying patients with damages or diseased parts of the brain
- lesion method (damaging or removing sections of the brain in animals and observing the effects)
What are electrodes?
-coin-shaped devices that can probe the brain
How do electrodes probe the brain?
-they detect electrical activity of neurons
How do we interpret the information electrodes give us?
-electrodes are connected to a machine that translates the electrical energy into wave patterns, known as “brain waves”
Define: EEG (electroencephalogram)
- a brain wave recording
- reflects activity of many cells at once (not precise)
- combined with computer technology, it can suppress background noise, leaving only electrical responses to the specific event being studied
What are 2 specific types of electrodes?
- needle electrodes
Define: needle electrodes
- wires or hollow glass tubes inserted directly into an exposed brain, or through tiny holes in the skull
- they can also be used to stimulate the brain with weak electrical currents
-they can be inserted into single cells
Define: TMS (transcranial magnetic simulation)
- a newer method of brain stimulation
- delivers a current through a wire coil placed on a person’s head
- procedure causes neurons to fire
What is known as a “virtual lesion method”?
-TMS (transcranial magnetic simulation)
Describe: PET Scan (positron-emission topography)
- records biochemical changes in the brain as they are happening
- uses radioactive glucose-like injections to observe activity levels in different parts of the brain
- color coded
Describe: MRI (magnetic resonance imaging)
- uses magnetic fields and radio frequencies to produce vibrations in the nuclei of atoms that make up bodily organs
- signals are converted into a high-contrast image
Describe: fMRI (functional MRI)
- ultra-fast version of MRI
- scans to correlate activity in specific brain areas
What do brain scans tell us exactly?
-they tell us WHERE an activity is happening, but not HOW or WHY