Methods of Research

Question 1

What can be used to measure structures in the brain?

Answer 1

Computerized Tomography (CT or “CAT”)
Magnetic Resonance Imaging (MRI)
Diffusion Tensor Imaging (DTI)

Question 2

Strength of CT scans:

Answer 2

Cheap and easy; usually first scan given after injury.

Question 3

Weakness of CT scans:

Answer 3

not very detailed pictures.

Question 4

What is a MRI?

Answer 4

Uses an interaction between radio waves and a strong magnetic field to reproduce a picture of body tissue.

Question 5

Strength of using an MRI?

Answer 5

High resolution pictures.
Can measure size of brain structures.
3-D representation from many angles.

Question 6

What is DTI?

Answer 6

A type of MRI that measures movement of water through the brain

Question 7

What is a DTI good for?

Answer 7

Great for reproducing a picture of white matter tracts.
Can measure thickness and how tightly packed the tracts are.
Gives you info about the quality of connections between brain regions.

Question 8

Water in _________ tends to move faster and in straighter lines.

Answer 8

white matter

Question 9

What are the 6 measuring functions of the brain?

Answer 9

1. Ablation
2. Transcranial Magnetic Stimulation (TMS)
3. Microelectrodes
4. Macroelectrodes – Electroencephalography (EEG)
5. Functional MRI (fMRI)
6. Positron Emission Tomography

Question 10

What is ablation?

Answer 10

Disrupt brain functioning by removing part of the brain and measure behavior.

Question 11

What is an example of ablation?

Answer 11

Split brain

Question 12

What is a weakness of ablation?

Answer 12

You cannot do it experimentally on humans, only animals.

Question 13

_______= Can measure effects in people who have had part of their brain damaged or removed for medical reasons.

Answer 13

Ablation

Question 14

What is TMS (Trascranial Magnetic Stimulation)?

Answer 14

Disrupt brain functioning by stimulating neurons with electrical current from outside of the skull and measure behavior.

Question 15

What are microelectrodes?

Answer 15

Records the activity of individual neurons from inside the brain.

Question 16

Strengths of using microelectrodes?

Answer 16

measure exactly what a neuron is doing.

Question 17

Weakness of using microelectrodes?

Answer 17

Invasive

Question 18

Give an example of a macroelectrode:

Answer 18

EEG

Question 19

What does an EEG do?

Answer 19

Record electrical activity of groups of neurons (inside or outside of the brain). (Thousands or millions of neurons).

Question 20

Weakness of an EEG:

Answer 20

can’t localize which part of the brain the signal came from aka bad spatial resolution.

Question 21

Strength of EEG:

Answer 21

Records very quickly (milliseconds) aka good temporal resolution.

Question 22

What does a functional MRI (fMRI) do?

Answer 22

Measures the amount of oxygenated blood in your brain.

Question 23

Why is a fMRI important?

Answer 23

More oxygen is very closely related to more neuronal activity

Question 24

Strengths of fMRI:

Answer 24

can localize where the changes in oxygenated blood flow (aka neuronal activity) happened aka good spatial resolution
Can measure the entire brain.

Question 25

Weakness of fMRI:

Answer 25

can’t record very quickly (blow flow is slow) aka poor temporal resolution.
indirect measure of neuronal function (it can be wrong).

Question 26

What does a Positron emission tomography test do?

Answer 26

Inject radioactive glucose in to brain

Question 27

_______ _______ is very closely related to neuronal activity.

Answer 27

Glucose consumption

Question 28

Weaknesses of a Positron emission tomography test?

Answer 28

Worse temporal and spatial resolution than fMRI.

Radioactivity isn’t safe to do many times within a short period of time.

Question 29

__________ - study of the microscopic structure of tissues

Answer 29

Histology

Question 30

1. Fixative – A chemical such as formalin; used to prepare and preserve body tissue.
2. Slice brain into thin sections (about 1/100th of a millimeter)
3. Attach a stain (either has a color or a fluorescent protein) to an antibody that binds to your protein of interest.

Answer 30

Histology

Question 31

What do targeted mutations do?

Answer 31

Remove (knockout) or over activate (over express)a gene and measure behavior.
Only done in animals.
Can also insert a gene in an animal related to a disease in humans to make a “model” of the disease.