Mapping the Brain

Question 1

What are 2 approaches to studying the brain?

Answer 1

• 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)

Question 2

What are electrodes?

Answer 2

-coin-shaped devices that can probe the brain

Question 3

How do electrodes probe the brain?

Answer 3

-they detect electrical activity of neurons

Question 4

How do we interpret the information electrodes give us?

Answer 4

-electrodes are connected to a machine that translates the electrical energy into wave patterns, known as “brain waves”

Question 5

Define: EEG (electroencephalogram)

Answer 5

• 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

Question 6

What are 2 specific types of electrodes?

Answer 6

• needle electrodes

- microelectrodes

Question 7

Define: needle electrodes

Answer 7

• 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

Question 8

Define: microelectrodes

Answer 8

-they can be inserted into single cells

Question 9

Define: TMS (transcranial magnetic simulation)

Answer 9

• a newer method of brain stimulation
• delivers a current through a wire coil placed on a person’s head
• procedure causes neurons to fire

Question 10

What is known as a “virtual lesion method”?

Answer 10

-TMS (transcranial magnetic simulation)

Question 11

Describe: PET Scan (positron-emission topography)

Answer 11

• 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

Question 12

Describe: MRI (magnetic resonance imaging)

Answer 12

• 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

Question 13

Describe: fMRI (functional MRI)

Answer 13

• ultra-fast version of MRI

- scans to correlate activity in specific brain areas

Question 14

What do brain scans tell us exactly?

Answer 14

-they tell us WHERE an activity is happening, but not HOW or WHY