EEG (Okt 29 lecture)

Question 1

What is Ohm’s law?

Answer 1

Voltage(E) = Current(I) x Resistance(R)

Question 2

How is current measured?

Answer 2

in Ampres

Question 3

What is current a measure of?

Answer 3

The actual flow of electricity through a conductor

Question 4

What letter represents current in Ohm’s law:

E = I x R ?

Answer 4

Current is represented by I (Intensity)

Question 5

How is voltage measured?

Answer 5

in Volts

Question 6

What is voltage a measure of?

Answer 6

Electromotive force (pressure that pushes the current through the conductor)–NOT a measure of flow of electricity

Question 7

What letter represents voltage in Ohm’s law:

E = I x R ?

Answer 7

Voltage is represented by E (Electromotive Force)

Question 8

Which part of Ohm’s law can be explained by a “water tank on the hill” analogy, where there is potential for water to flow, even if no water is actually flowing?

Answer 8

Voltage (E; Electromotive Force)

Question 9

How is resistance measured?

Answer 9

in Ohms

Question 10

What is resistance a measure of?

Answer 10

The ability of the substance to keep charged articles from passing

Question 11

What letter represents resistance in Ohm’s law:

E = I x R ?

Answer 11

Resistance is represented by R

Question 12

What 3 factors influence resistance?

Answer 12

(1) composition of a substance (e.g. copper vs. zinc)
(2) its length
(3) its diameter

Question 13

What is Impendance (Z)?

Answer 13

The resistance to the flow of alternating current (AC)

Question 14

If a magnetic field passes through a conductor, it…..

Answer 14

induces an electrical current

this is how devices can cause interference

Question 15

How is a neuronal dipole created?

Answer 15

Negativity at apical dendrites and positivity at the soma

Question 16

Which cells are best for ERP recordings?

Answer 16

Pyramidal cortical cells

Question 17

Which cells are most unlikely to be recorded with an ERP?

Answer 17

Cerebellar cells (bc highly folded surface may result in nearby cortical patches cancelling)

Question 18

EEG is sensitive to….?

Answer 18

Excitatory & inhibitory postsynaptic potentials at apical dendrites (of massively synchronized cortical neurons

Question 19

Is EEG sensitive to action potentials?

Answer 19

NO

Question 20

Increasing the number of trials also increases…

Answer 20

Signal-to-Noise Ratio (SNR)

Question 21

Doubling the SNR _____ noise about 30%, but requires _____ times as many trials?

Answer 21

Reduces noise about 30%, but requires 4x as many trials!

Question 22

What are the 3 types of electrodes used?

Answer 22

Active (A), Reference (R), & Ground (G)

Question 23

What is the standard placement system for EEG?

Answer 23

The 10-20 System

Question 24

Electrode Labeling: F stands for?

Answer 24

Frontal

Question 25

Electrode Labeling: C stands for?

Answer 25

Central

Question 26

Electrode Labeling: T stands for?

Answer 26

Temporal

Question 27

Electrode Labeling: P stands for?

Answer 27

Parietal

Question 28

Electrode Labeling: O stands for?

Answer 28

Occipital

Question 29

Electrode Labeling: Fp stands for?

Answer 29

Fronto-polar | front-most electrodes

Question 30

Electrode Labeling: AF stands for?

Answer 30

Anterior-Frontal

Question 31

Electrode Labeling: FC stands for?

Answer 31

Fronto-Central

Question 32

Electrode Labeling: CP stands for?

Answer 32

Centro-Parietal

Question 33

Electrode Labeling: PO stands for?

Answer 33

Parieto-Occipital

Question 34

Electrode Labeling: ODD numbers represent which hemisphere?

Answer 34

Left hemisphere

Question 35

Electrode Labeling: EVEN numbers represent which hemisphere?

Answer 35

Right hemisphere

Question 36

Signal transmission between neurons is _____ and within neurons it is _______?

Answer 36

Chemical between neurons; | electrical within a neuron

Question 37

Neurons: Where is information from other neurons collected?

Answer 37

Dendrites

Question 38

Neurons: Where is information processed?

Answer 38

Cell Body (Soma)

Question 39

Neurons: Where is information from one neuron passed on to a target neuron?

Answer 39

Axon

Question 40

What is the voltage of the resting potential?

Answer 40

-70mV

Question 41

Which ions produce the resting potential?

Answer 41

Sodium (Na+), Chlorid (Cl-), Potassium (K+), and Protein Anions (A-)

Question 42

A- ions (protein anions) and K+ ions have higher concentrations ______ (inside/outside) the axon

Answer 42

Inside

Question 43

Cl- and Na+ ions are more concetrated ______ (inside/outside) the axon

Answer 43

Outside

Question 44

The action potential makes the inside _______ (pos/neg) relative to the outside, and then abruptly reverses again?

Answer 44

APs make the inside POSITIVE relative to the outside

Question 45

What are the 3 phases of an action potential?

Answer 45

(1) Depolarization (2) Repolarization (3) Hyperpolarization

Question 46

What occurs in depolarization?

Answer 46

Initiated by opening of Na+ channels | Na+ influx

Question 47

What occurs in repolarization?

Answer 47

Closing of Na+ channels and opening of K+ channels (K+ efflux)

Question 48

What occurs in hyperpolarization?

Answer 48

The extra-cellular side becomes more positive due to K+ efflux

Question 49

Do ERPs reflect action potentials, or postsynaptic potentials?

Answer 49

Postsynaptic potentials!!