Module 2

Question 1

What is EEG?

Answer 1

Electroencephalography. It measures the movement of ions inside, across, and outside neural cell membranes.

Question 2

What is an ERP?

Answer 2

An event related potential. AKA electrical changes as a result of a stimulus/making a movement.

Question 3

How is the ERP extracted?

Answer 3

Taking the average of ‘time locked’ slices of multiple trials.

Question 4

What is the CNV?

Answer 4

The contingent negative variation. It is dependent on action anticipation.

Question 5

What is the RP?

Answer 5

Volitional preparation and initiation - or the readiness potential. Extracted when movements are volitional.

Question 6

What is the LRP?

Answer 6

The lateralized readiness potential. We can use this to determine when we decide which hand to use in a movement.

Question 7

How does the length of the foreperiod affect the CNV?

Answer 7

No CNV will develop if the foreperiod is too short.

If the foreperiod is too long, the CNV will flatten quickly. A state of anticipation is hard to maintain.

Question 8

What is premotoric processing?

Answer 8

Pre-motor processing between stimulus onset and LRP onset (encompasses SI and RS).

Question 9

What is motoric processing?

Answer 9

Pre-motor processing between the LRP and EMG onset (programming).

Question 10

What is stimulus locked LRP?

Answer 10

Time locking the LRP to the onset of the stimulus. This tells us how long SI and RS take.

Question 11

What is response-locked LRP?

Answer 11

Time locking the LRP to the response, and interpreting how long it took to get there. Measures length of the response programming stage.

Question 12

LRP onset occurs at what stage of information processing?

Answer 12

After response selection.

Question 13

What happens to the CNV when we know more precues to a task?

Answer 13

It increases. More information = more anticipation.

Question 14

What happens to the LRP if we know more precues to a task?

Answer 14

It is larger during the foreperiod, as you already know which hand to use.

Question 15

What is the same/different about the LRPs of compatible and incompatible mappings?

Answer 15

Processing stage/onset is the same (no difference in SI and RS).

Incompatible LRP goes in the wrong direction, then corrects. This is due to the wrong hand being anticipated first.

Question 16

Why do compatible and incompatible LRPs start at the same time?

Answer 16

Dual process model: automatic process finishes first.

Question 17

What is TMS, and what does it measure?

Answer 17

Transcranial magnetic stimulation.

By magnetically stimulating cortex neurons, an EMG response is recorded in the muscle.

Question 18

What is the MEP?

Answer 18

Motor evoked potential. It is the EMG response in the muscle as a result of TMS stimulation.

Question 19

What is the silent period (SP)?

Answer 19

The refractory period and activation of inhibitory interneurons of the motor cortex. Needs background activity to be observed.

Question 20

What is the Hoffman reflex (H-reflex)?

Answer 20

Direct electrical activation of an afferent nerve.

Question 21

What does the M-wave represent?

Answer 21

The size of the electrical stimulus by the H-reflex.

Question 22

What does the H-wave represent?

Answer 22

Indicates the size of the reflex response to a given stimulus. AKA the size of the muscle response.

Question 23

What is sub-threshold TMS?

Answer 23

TMS is added to existing excitability in order to produce a twitch. The goal is not to produce a twitch directly from TMS.

Question 24

What happens to an MEP if there is a long foreperiod?

Answer 24

MEP does not vary. SP is longer, as we are waiting longer for activation.

Question 25

What happens to an MEP if there is a short foreperiod?

Answer 25

A smaller MEP, which indicates inhibition.

A shorter silent period, which means more activation.

Question 26

Why is there both inhibition and activation when a foreperiod is short?

Answer 26

Both excitatory and inhibitory neurons are inhibited during preparation.

Inhibit the excitatory neurons -> get a smaller MEP.

Inhibit the inhibitory neurons -> shorter SP, more excitation.

Question 27

Why is there MEP suppression during movement preparation?

Answer 27

In order to not preemptively make a response.