. 2020 Dec 17;29:102537. doi: 10.1016/j.nicl.2020.102537

Table 4.

Details of the main ERP components assessed by the studies included in the systematic review.

ERP	Time window	Polarity	Distribution	Source	Functional Meaning
¹P1	Auditory ≈ 50 ms post-stimulus onset Visual ≈ 100 ms post-stimulus onset	Positive	Auditory: Fronto-Central Visual: Occipital	Auditory: superior temporal gyrus and medial frontal cortex Visual: extrastriate occipital cortex and posterior parietal regions	P1 represents a basic perceptual processing of the stimulus and provides a quantitative measure of the functional integrity of the sensory pathways. Additionally, it is usually interpreted as a neurophysiological indicator of preferential attention to sensory inputs and as an index of alertness status and attention.
²N1	Auditory: 75–150 ms post-stimulus onset Visual: 100–175 ms post-stimulus onset	Negative	Auditory: Fronto-Central Visual: Temporo-Occipital	Auditory: Primary auditory cortex and frontal regions. Visual: Inferior occipital cortex and the occipito-temporal junction	N1 is assumed to reflect selective attention to basic stimulus characteristics, an initial selection for later pattern recognition, which is modulated by the arousal and emotional salience of the stimulus.
³N170	125–225 ms post-stimulus onset	Negative	Occipito-Temporal	Posterior fusiform and inferior-temporal gyri	N170 is a component mainly associated with visual processing of human faces. It reflects the identification and structural encoding of faces and eyes, being considerably reduced for non-facial stimuli.
⁴VPP	140–180 ms post-stimulus onset	Positive	Central	Inferior temporal cortex	VPP is evoked during the processing of single images, exhibiting its largest amplitude response for faces. The functional similarity and the temporal coincidence with N170 have led to consider that both are flip sides of the same neural generators.
⁵P2	150–250 ms post-stimulus onset	Positive	Auditory: Central Visual: Frontal	Auditory: Primary and associative auditory cortex. Visual: inferior occipital cortex	P2 represents higher order perceptual processing modulated by attention and linked to memory. This component is part of a cognitive matching system that compares sensory inputs with stored memory, being involved in stimulus classification and attention modulation of nontarget stimuli.
N2	200–350 ms post-stimulus onset	Negative			N2 is considered to be a family of responses that differ in their distribution, source and interpretation, based on the features of the eliciting task, possibly reflecting task demands. However, all of them are part of the attentional processing and appear to indicate a detection of a deviation between a particular stimulus and the participant’s expectation.
⁶N2b	200–350 ms post-stimulus onset	Negative	Fronto-Central	Anterior cingulate, frontal and superior temporal cortex	N2b is mainly elicited during the Stop Signal, Eriksen Flanker and Go/NoGo (NoGo-N2) tasks. It is associated with several processes such detection of response conflict (conflict monitoring), response inhibition or error detection. It is larger for non-targets (which do not require response) and it is usually observed along with the P3a component.
⁷N2c	200–350 ms post-stimulus onset	Negative	Auditory: Central Visual: Parieto-Occipital	Auditory: supratemporal auditory cortex Visual: occipito-temporal regions	N2c is most frequently elicited during the Continuous Performance and Oddball tasks. It partly reflects the conscious allocation of attentional resources to stimuli indicated as salient, as well as the voluntary switch of attention operated. It is larger for targets and observed along with P3b component.

ERP	Time window	Polarity	Distribution	Source	Interpretation
⁸ERN	80–150 ms after an erroneous response	Negative	Fronto-Central	Anterior cingulate cortex	ERN represents the early automatic detection of an error. This component is considered to reflect a process involved in evaluating the need for, or in implementing, control. The Flanker, Go/NoGo, Stop Signal and Stroop tasks (i.e. paradigms requiring speeded responses) are the most commonly used paradigms for assessing error processing.
⁹Pe	200–400 ms after response onset	Positive		Caudal and rostral portions of anterior cingulate cortex	Pe is a slow wave that reflects conscious error recognition. Similar to the ERN, the Flanker, Go/NoGo, Stop Signal and Stroop tasks are the most commonly used paradigms for eliciting this component.
¹⁰FRN	250–300 ms after feedback presentation	Negative	Fronto-Central	Anterior mid cingulate cortex	FRN follows the performance feedback, being linked to its valence and magnitude. Indexes an early evaluation, through a bottom-up mechanism of the feedback provided by the environment. It may also be an indicator of reward prediction and expectancy violation.
¹¹P3	250–600 ms post-stimulus onset	Positive			P3 (or P300) is considered to index a wide variety of neurocognitive processes, including context processing, attention, working memory, response selection, stimulus salience, response inhibition and reward or emotional processing, depending on the type of cognitive processes required by the task. This component is usually divided into two subcomponents: P3a and P3b.
P3a	250–350 ms after the stimulus onset	Positive	Fronto-Central	Prefrontal cortex	P3a is mainly elicited by novelty oddball paradigms. This waveform has been associated with the involuntary attention orienting in response to changes in the environment. It reflects the bottom-up saliency that is determined by the novelty of the stimulus.
P3b	300–600 ms after the stimulus onset	Positive	Parietal	Temporo-parietal junction and deeper sources in the thalamus and hippocampus	P3b is frequently elicited by oddball and stimulus selection paradigms. This component has been associated with the voluntary attention and the updating of the stimulus representation in the working memory–usually indicating the top-down classification of the stimulus as relevant or target. In Go/NoGo paradigms, P3b elicited by NoGo stimulus may reflects response inhibition (NoGo-P3) and involve prefrontal regions. Sometimes this component is simply called P3.
¹²N400	300–600 ms post stimulus	Negative	Centro-Parietal	Anterior pre-frontal, superior temporo-parietal cortex and hippocampus and cingulate regions	N400 is a component commonly related to semantic incongruence in language paradigms, it is also typically observed in recognition–recall memory paradigms and is often referred to as an old–new effect. This component is associated with stimulus familiarity and memory trace strength.
¹³LPC	500–800 ms post stimulus	Positive	Centro-Parietal	Prefrontal cortex	LPC is related to higher order cognitive processes, such as recognition of the stimuli and decision accuracy/confidence. This component reflects the selection of a response category and the evaluation of the success of a category-related decision or memory match. Sometimes this component is also called P600.