lecture 11

Question 1

what is EEG

Answer 1

non invasive method that measures electrical activity in the brain
- electrodes on the scalp to measure local electric fields (dipolels) in hte brain
- great temporal resolution but low spatial
used for attentional processes, sleep disorders, epilepsy

Question 2

EEG history

Answer 2

Hans berger invented the technique

- investigating telepathy

Question 3

neurophysiologiy of EEG

Answer 3

summation of IPSP and EPSP

• summate across pyramidal cells that produce dipoles
• require large number of neurons to be active and must be lined up (- on top + on bottom)

Question 4

EEG positive/negative deflections

Answer 4

cannot determine if activity is excitatory or inhibitory

- only have to do with where EPSP or IPSP occurs on cell

Question 5

negative deflection

Answer 5

negative ions at dendrites

Question 6

positive deflection

Answer 6

positive ions at dendrites

Question 7

units of EEG

Answer 7

microvolts uV

- require powerful amplifier and electrode gell because skull membranes weaken signal

Question 8

inverse problem

Answer 8

impossible to go from electrical activity on scalp to determine electircal activity in brain

• going from set of observations to causal relationship
• source localization algorithims change this
• fMRI is better at spatial resolution

Question 9

compliment behavior

Answer 9

EEG cannot be used on its own, only to compliment behavior

- need an idea of what youre looking for

Question 10

oscillatory activity

Answer 10

repetitive frequency patterns that occur within brain

• vary in amplitude, location and frequency
• functionally relevant and related to behavior (mostly)
• represent synchronization of neural activity in brain

Question 11

types of oscilatory activity

Answer 11

delta- sleep and motivated behavior
theta- cognitive control/effort, memory, goal completion
alpha- attention/wakefulness
beta- alertness, GABA and inhibitory processing, motor system
gamma- memory formation and processing

Question 12

problem with oscillatory activity

Answer 12

many tasks elicit same levels- debate to what it emans

same oscilatory activity at different parts of scalp means different things

Question 13

ERPs

Answer 13

time locked - large amount of identical trials averaged

positive- down, negative- up

Question 14

oddball paradigm- ERP task

Answer 14

people see two different stimuli, one common and other odd

• can be active/passive
• visualm auditory or tactile

Question 15

p300

Answer 15

oddball task elicits measurable brain response - P300

• positive bump around 300ms after simulus seen
• signal of surprise or context updating
• linked to attention and NE system

Question 16

doors paradigm- ERP task

Answer 16

person has to choose between doors and get feedback about desicion

• identify which door leads to winds more often
• linked to reward learning and decision making
• elicits reward positivity around 250-350ms

Question 17

reward positivity

Answer 17

FRN- feedback related negativity

• gain/win feedback slightly more positive than loss
• represents reward prediction error with links to dopamine and how we make predictions about environment

Question 18

lateralized readiness potential

Answer 18

represents the beginning of movements

- libets clock study suggests voluntary action preceded by brain activity

Question 19

error related negativity

Answer 19

linked to error processing

- when people make errors their EEG is more negative