ERP Components

Question 1

Visual C1

Answer 1

primary visual cortex
posterior midline sites
Negative for upper field, positive for lower field stimuli (can merge with P1)
40-60ms onset, 80-100ms peak
effected by sensory factors, not task

Question 2

Visual P1

Answer 2

extrastriate visual cortex
lateral occipital sites
60-90ms onset, 100-130ms peak
effected by stimulus parameters, direction of attention, arousal

Question 3

Visual Anterior N1

Answer 3

central and midline sites
100-150ms peak
response preparation
effected by spatial attention

Question 4

Visual Posterior N1

Answer 4

parietal and lateral occipital cortex sites
150-200ms peak
larger in discrimination tasks (because choice is higher)
effected by spatial attention

Question 5

Visual N170

Answer 5

lateral occipitotemporal sites in right hemisphere
170ms peak, 150-200ms onset
larger for faces but not specific
part of posterior N1

Question 6

Visual P2

Answer 6

frontal sites
peak 200ms
cognitive matching system - recognition
further research needed

Question 7

Visual Posterior N2

Answer 7

or N2b

larger for targets especially when infrequent

Question 8

Visual Anterior N2

Answer 8

larger for arrays containing pop out items and incompatible trials in Stroop tasks

Question 9

Visual N2pc

Answer 9

posterior sites contralateral to attended objects
followed by sustained negativity
selection process where objects stored in memory
not impacted by probability

Question 10

Contralateral Delay Activity

Answer 10

sustained activity
memory storage
increases to 4 items then plateaus

Question 11

Auditory Mismatch Negativity

Answer 11

N2a
automatic response to deviant stimulus
160-220ms peak, sustained activity
frontal/ central regions
auditory cortex
comparison of incoming stimulus with echoic memory
attenuated when attention strongly focused on a different auditory source

Question 12

Higher Cognitive Responses P3

Answer 12

peak 350ms for auditory, 400ms for visual
decision making, updating of working memory
modality independent
larger as more resources devoted to task
size inversely related to probability + uncertainty
increased task difficulty may increase or decrease as effort and uncertainty affected

Question 13

Higher Cognitive Responses P3a, P3b

Answer 13

P3a = parietal sites, for novel distractors 
P3b = frontal/ central sites, for infrequent targets, more common

Question 14

Higher Cognitive Responses N400

Answer 14

left temporal lobe, PFC
for meaningful stimuli
semantic analysis, sensitive to semantic incongruity
word or picture stimuli