EEG and ERP

Question 1

What does EEG and ERP both measure?

Answer 1

Record brain waves in neurones

Question 2

What is the stop signal that makes neurones fire

Answer 2

Inhibitory GABAnergic

Question 3

What is electrophysiology?

Answer 3

measure of brain activity during events

Question 4

What is membrane potential?

Answer 4

The driving force for all electrical and magnetic events

Question 5

What is EEG?

Answer 5

Measuring the current between electrodes on the scalp and surface
Minimum of 3 electrodes
There is the measure of ongoing tasks
Any movement of the eye causes such as blink will produce an artefact/response
Direct measure
Can give info on Arousal, Attention and Affect

Question 6

Different brain waves in EEG

Answer 6

Delta waves-0-4HZ
Theta waves-4-8HZ
Alpha waves-8-13HZ
Beta waves-13-30HZ
Gamma waves-30+HZ

Question 7

EEG changes during sleep

Answer 7

Alertness-beta waves
Relaxing- Alpha waves
Sleeping-Theta waves
Light sleep
deep sleep-Delta waves
REM sleep-dreaming

Question 8

Pathologic oscillations

Answer 8

EEG is used for Parkinsons, stroke, schizophrenia

It is also used especially for Epilepsy

Question 9

Where does the EEG signal come from?

Answer 9

Local field potentials
When excitatory inputs come through into the cell releasing glutamate(due to influx from sodium and calcium)
Little negative charge occurs outside
Flow of current around the neurone creating a dipole
Negative voltage is then recorded on the cortical surface
Skull can block the cortical surface

Question 10

Neural basis of EEG

Answer 10

Summation of post synaptic transmission(inhibitory and excitatory
Pyramidal neurones are a major part of the cortex and make up large sum of the EEG
Around 108 neurones is needed to create an EEG image
Cell bodies in layer 6 and dendrites coming up to L1
L1 is where EEG is recorded

Question 11

Event Related Potential

Answer 11

Provide a direct measure of brains response to stimuli

Question 12

ERP components to true signal

Answer 12

Raw EEG is the data collected that needs to be processed
The average would need around 200 trails to reduce noise from raw EEG
True signal is when there is the fusion of the raw EEG and average

Question 13

What evoked Potential

Answer 13

electrical potential in a specific pattern recorded from a specific part of the nervous system(stimulus)-Early response

Question 14

Event related Potential

Answer 14

are very small voltages generated in the brain structures in response to specific events or stimuli(Late response)

Question 15

What is P and N waves

Answer 15

P waves have downwards action

N waves have upwards action

Question 16

Relevant and irrelevant tasks in ERP

Answer 16

We have to stimuli present were one is irrelevant and one is relevant and is used to compare

Question 17

The Irreversible problem

Answer 17

Depending on where you put the electrode there can be slight differences in charges of the dipole
Folds in the cortex may have aligned differences

Question 18

ERP/EEG pros

Answer 18

Good time resolution
Portable 
Affordable
Silent so can be used for auditory processing
Can be combined with fMRI

Question 19

Simultaneous Resting-State EEG-fMRI

Answer 19

EG recording through the detection of neural waves with different frequency and amplitude and by fMRI through the estimation of different resting state networks linked to specific cerebral functions.