Editing Event-related potential (section)

== Research ==
ERPs are used extensively in [[neuroscience]], [[cognitive psychology]], [[cognitive science]], and [[Psychophysiology|psycho-physiological]] research. [[Experimental psychology|Experimental psychologists]] and [[neuroscientist]]s have discovered many different stimuli that elicit reliable ERPs from participants. The timing of these responses is thought to provide a measure of the timing of the brain's communication or timing of information processing. For example, in the checkerboard paradigm described above, healthy participants' first response of the visual cortex is around 50–70 ms. This would seem to indicate that this is the amount of time it takes for the [[Transduction (physiology)|transduced]] visual stimulus to reach the [[telencephalon|cortex]] after [[light]] first enters the [[eye]]. Alternatively, the [[P300 (neuroscience)|P300]] response occurs at around 300ms in the [[oddball paradigm]], for example, regardless of the type of stimulus presented: [[Visual system|visual]], [[tactition|tactile]], [[sound|auditory]], [[olfaction|olfactory]], [[gustatory]], etc. Because of this general invariance with regard to stimulus type, the P300 component is understood to reflect a higher cognitive response to unexpected and/or cognitively [[Salience (neuroscience)|salient]] stimuli. The P300 response has also been studied in the context of information and memory detection.<ref>{{cite journal | vauthors = McCormick B |year=2006 |title=Your Thoughts May Deceive You: The Constitutional Implications of Brain Fingerprinting Technology and How It May Be Used to Secure Our Skies |journal=Law & Psychology Review |volume=30 |pages=171–84 }}</ref> In addition, there are studies on abnormalities of P300 in depression. Depressed patients tend to have a reduced P200 and P300 amplitude and a prolonged P300 latency.<ref name=":0" />

Due to the consistency of the P300 response to novel stimuli, a [[brain–computer interface]] can be constructed which relies on it. By arranging many signals in a grid, randomly flashing the rows of the grid as in the previous paradigm, and observing the P300 responses of a subject staring at the grid, the subject may communicate which stimulus he is looking at, and thus slowly "type" words.<ref>{{cite journal | vauthors = Farwell LA, Donchin E | title = Talking off the top of your head: toward a mental prosthesis utilizing event-related brain potentials | journal = Electroencephalography and Clinical Neurophysiology | volume = 70 | issue = 6 | pages = 510–23 | date = December 1988 | pmid = 2461285 | doi = 10.1016/0013-4694(88)90149-6 | s2cid = 4547500 }}</ref>

Another area of research in the field of ERP lies in the [[efference copy]]. This predictive mechanism plays a central role in for example human verbalization.<ref>{{cite journal | vauthors = Roach BJ, Ford JM, Biagianti B, Hamilton HK, Ramsay IS, Fisher M, Loewy R, Vinogradov S, Mathalon DH | display-authors = 6 | title = Efference copy/corollary discharge function and targeted cognitive training in patients with schizophrenia | journal = International Journal of Psychophysiology | volume = 145 | pages = 91–98 | date = November 2019 | pmid = 30599145 | pmc = 6616012 | doi = 10.1016/j.ijpsycho.2018.12.015 }}</ref><ref>{{cite journal | vauthors = Brumberg JS, Pitt KM | title = Motor-Induced Suppression of the N100 Event-Related Potential During Motor Imagery Control of a Speech Synthesizer Brain–Computer Interface | journal = Journal of Speech, Language, and Hearing Research | volume = 62 | issue = 7 | pages = 2133–2140 | date = July 2019 | pmid = 31306609 | pmc = 6808362 | doi = 10.1044/2019_JSLHR-S-MSC18-18-0198 }}</ref> Efference copies, however, do not only occur with spoken words, but also with inner language - i.e. the quiet production of words - which has also been proven by event-related potentials.<ref>{{cite journal | vauthors = Whitford TJ, Jack BN, Pearson D, Griffiths O, Luque D, Harris AW, Spencer KM, Le Pelley ME | display-authors = 6 | title = Neurophysiological evidence of efference copies to inner speech | journal = eLife | volume = 6 | date = December 2017 | pmid = 29199947 | pmc = 5714499 | doi = 10.7554/eLife.28197 | doi-access = free }}</ref>

Other ERPs used frequently in research, especially [[neurolinguistics|neurolinguistics research]], include the [[ELAN (neurolinguistics)|ELAN]], the [[N400 (neuroscience)|N400]], and the [[P600 (neuroscience)|P600/SPS]]. The analysis of ERP data is also increasingly supported by machine learning algorithms.<ref>{{cite journal | vauthors = Mueller A, Candrian G, Kropotov JD, Ponomarev VA, Baschera GM | title = Classification of ADHD patients on the basis of independent ERP components using a machine learning system | journal = Nonlinear Biomedical Physics | volume = 4 | issue = Suppl 1 | pages = S1 | date = June 2010 | pmid = 20522259 | pmc = 2880795 | doi = 10.1186/1753-4631-4-S1-S1 | doi-access = free }}</ref><ref>{{cite conference | vauthors = Frick J, Rieg T, Buettner R | title = Detection of schizophrenia: a machine learning algorithm for potential early detection and prevention based on event-related potentials. | conference = Proceedings of the 54th Hawaii International Conference on System Sciences | date = 2021 | doi = 10.24251/HICSS.2021.460 | doi-access = free | hdl = 10125/71076 | hdl-access = free }}</ref>

=== Number of trials ===
A common issue in ERP studies is whether the observed data have a sufficient number of trials to support statistical analysis.<ref name=":1">{{Cite journal |last=Clayson |first=Peter E. |date=2024 |title=The psychometric upgrade psychophysiology needs |journal=[[Psychophysiology]] |language=en |volume=61 |issue=3 |pages=e14522 |doi=10.1111/psyp.14522 |pmid=38228400 |pmc=10922751 |issn=0048-5772}}</ref> The background noise in any ERP for any individual can vary. Therefore simply characterizing the number of ERP trials needed for a robust component response is inadequate. ERP researchers can use metrics like the standardized measurement error (SME) to justify the examination of between-condition or between-group differences<ref>{{cite journal | vauthors = Luck SJ, Stewart AX, Simmons AM, Rhemtulla M | title = Standardized measurement error: A universal metric of data quality for averaged event-related potentials | journal = Psychophysiology | volume = 58 | issue = 6 | pages = e13793 | date = June 2021 | pmid = 33782996 | pmc = 8169536 | doi = 10.1111/psyp.13793 }}</ref> or estimates of internal consistency to justify the examination of individual differences.<ref>{{cite journal | vauthors = Clayson PE, Miller GA | title = Psychometric considerations in the measurement of event-related brain potentials: Guidelines for measurement and reporting | journal = International Journal of Psychophysiology | volume = 111 | pages = 57–67 | date = January 2017 | pmid = 27619493 | doi = 10.1016/j.ijpsycho.2016.09.005 }}</ref><ref>{{cite journal | vauthors = Clayson PE, Brush CJ, Hajcak G | title = Data quality and reliability metrics for event-related potentials (ERPs): The utility of subject-level reliability | journal = International Journal of Psychophysiology | volume = 165 | pages = 121–136 | date = July 2021 | pmid = 33901510 | doi = 10.1016/j.ijpsycho.2021.04.004 | s2cid = 233408794 | url = https://psyarxiv.com/ja6bw/download | url-access = subscription }}</ref><ref name=":1" />