N100

There are three subtypes of adult auditory N100.

• N100b or vertex N100, peaking at 100 ms.
• T-complex N100a, largest at temporal electrodes at 75 ms
• T-complex N100c, follows N100a and peaks at about 130 ms. The two T-complex N100 evoked potentials are created by auditory association cortices in the superior temporal gyri.

The N100 is often known as the "auditory N100" because it is elicited by perception of auditory stimuli. Specifically, it has been found to be sensitive to things such as the predictability of an auditory stimulus, and special features of speech sounds such as voice onset time.

It occurs during both REM and NREM stages of sleep though its time is slightly delayed.{{Cite journal

| doi = 10.1097/00001756-199604100-00026

| last1 = Nordby | first1 = H.

| last2 = Hugdahl | first2 = K.

| last3 = Stickgold | first3 = R.

| last4 = Bronnick | first4 = K. S.

| last5 = Hobson | first5 = J. A.

| title = Event-related potentials (ERPs) to deviant auditory stimuli during sleep and waking

| journal = NeuroReport

| volume = 7

| issue = 5

| pages = 1082–1086

| year = 1996

| pmid = 8804056

| s2cid = 40303719 }} During stage 2 NREM it seems responsible for the production of K-complexes.{{Cite journal

| doi = 10.1016/0013-4694(96)95103-2

| last1 = Niiyama | first1 = Y.

| last2 = Satoh | first2 = N.

| last3 = Kutsuzawa | first3 = O.

| last4 = Hishikawa | first4 = Y.

| title = Electrophysiological evidence suggesting that sensory stimuli of unknown origin induce spontaneous K-complexes

| journal = Electroencephalography and Clinical Neurophysiology

| volume = 98

| issue = 5

| pages = 394–400

| year = 1996

| pmid = 8647042

}} N100 is reduced following total sleep deprivation and this associates with an impaired ability to consolidate memories.{{Cite journal

| doi = 10.1016/j.nlm.2009.01.008

| last1 = Mograss | first1 = M. A.

| last2 = Guillem | first2 = F.

| last3 = Brazzini-Poisson | first3 = V.

| last4 = Godbout | first4 = R.

| title = The effects of total sleep deprivation on recognition memory processes: A study of event-related potential

| journal = Neurobiology of Learning and Memory

| volume = 91

| issue = 4

| pages = 343–352

| year = 2009

| pmid = 19340944

| s2cid = 35985772 }}

The N100 depends upon unpredictability of stimulus: it is weaker when stimuli are repetitive, and stronger when they are random. When subjects are allowed to control stimuli, using a switch, the N100 may decrease. This effect has been linked to intelligence, as the N100 attenuation for self-controlled stimuli occurs the most strongly (i.e., the N100 shrinks the most) in individuals who are also evaluated as having high intelligence. Indeed, researchers have found that in those with Down syndrome "the amplitude of the self-evoked response actually exceeded that of the machine-evoked potential". Being warned about an upcoming stimulus also reduces its N100.{{Cite journal

| doi = 10.1016/0013-4694(81)90183-8

| last1 = Schafer | first1 = E. W.

| last2 = Amochaev | first2 = A.

| last3 = Russell | first3 = M. J.

| title = Knowledge of stimulus timing attenuates human evoked cortical potentials

| journal = Electroencephalography and Clinical Neurophysiology

| volume = 52

| issue = 1

| pages = 9–17

| year = 1981

| pmid = 6166459

}}

The amplitude of N100 shows refractoriness upon repetition of a stimulus; in other words, it decreases at first upon repeated presentations of the stimulus, but after a short period of silence it returns to its previous level. Paradoxically, at short repetition the second N100 is enhanced both for sound{{Cite journal

| doi = 10.1097/00001756-199412000-00027

| last1 = Budd | first1 = T. W.

| last2 = Michie | first2 = P. T.

| title = Facilitation of the N1 peak of the auditory ERP at short stimulus intervals

| journal = NeuroReport

| volume = 5

| issue = 18

| pages = 2513–2516

| year = 1994

| pmid = 7696592

}} and somatosensory stimuli.

With paired clicks, the second N100 is reduced due to sensory gating.{{Cite journal

| last1 = Hanlon | first1 = F. M.

| last2 = Miller | first2 = G. A.

| last3 = Thoma | first3 = R. J.

| last4 = Irwin | first4 = J.

| last5 = Jones | first5 = A.

| last6 = Moses | first6 = S. N.

| last7 = Huang | first7 = M.

| last8 = Weisend | first8 = M. P.

| last9 = Paulson | first9 = K. M.

| last10 = Edgar

| doi = 10.1111/j.1469-8986.2005.00299.x | first10 = J. C.

| last11 = Adler | first11 = L. E.

| last12 = Cañive | first12 = J. M.

| title = Distinct M50 and M100 auditory gating deficits in schizophrenia

| journal = Psychophysiology

| volume = 42

| issue = 4

| pages = 417–427

| year = 2005

| pmid = 16008770

| pmc =

}}

The difference between many consonants is their voice onset time (VOT), the interval between consonant release (onset) and the start of rhythmic vocal cord vibrations in the vowel. The voiced stop consonants /b/, /d/ and /g/ have a short VOT, and unvoiced stop consonants /p/, /t/ and /k/ long VOTs. The N100 plays a role in recognizing the difference and categorizing these sounds: speech stimuli with a short 0 to +30 ms voice onset time evoke a single N100 response but those with a longer (+30 ms and longer) evoked two N100 peaks and these are linked to the consonant release and vocal cord vibration onset.{{Cite journal

| last1 = Steinschneider | first1 = M.

| last2 = Volkov | first2 = I. O.

| last3 = Fishman | first3 = Y. I.

| last4 = Oya | first4 = H.

| last5 = Arezzo | first5 = J. C.

| last6 = Howard III | first6 = M. A.

| title = Intracortical Responses in Human and Monkey Primary Auditory Cortex Support a Temporal Processing Mechanism for Encoding of the Voice Onset Time Phonetic Parameter

| doi = 10.1093/cercor/bhh120

| journal = Cerebral Cortex

| volume = 15

| issue = 2

| pages = 170–186

| year = 2004

| pmid = 15238437

| pmc =

| doi-access = free

}}{{Cite journal

| last1 = Steinschneider | first1 = M.

| last2 = Volkov | first2 = I. O.

| last3 = Noh | first3 = M. D.

| last4 = Garell | first4 = P. C.

| last5 = Howard III | first5 = M. A.

| title = Temporal encoding of the voice onset time phonetic parameter by field potentials recorded directly from human auditory cortex

| journal = Journal of Neurophysiology

| volume = 82

| issue = 5

| pages = 2346–2357

| year = 1999

| pmid = 10561410

| doi = 10.1152/jn.1999.82.5.2346

}}

Traditionally, 50 to 150 ms evoked potentials were considered too short to be influenced by top-down influences from the prefrontal cortex. However, it is now known that sensory input is processed by the occipital cortex by 56 ms and this is communicated to the dorsolateral frontal cortex where it arrives by 80 ms.{{Cite journal

| last1 = Foxe | first1 = J.

| last2 = Simpson | first2 = G.

| doi = 10.1007/s00221-001-0906-7

| title = Flow of activation from V1 to frontal cortex in humans

| journal = Experimental Brain Research

| volume = 142

| issue = 1

| pages = 139–150

| year = 2002

| pmid = 11797091

| pmc =

| s2cid = 25506401

}} Research also finds that the modulation effects upon N100 are affected by prefrontal cortex lesions.{{Cite journal

| doi = 10.3109/00207459408986053

| last1 = Blenner | first1 = J. L.

| last2 = Yingling | first2 = C. D.

| title = Effects of prefrontal cortex lesions on visual evoked potential augmenting/reducing

| journal = The International Journal of Neuroscience

| volume = 78

| issue = 3–4

| pages = 145–156

| year = 1994

| pmid = 7883451

}} These higher-level areas create the attentive, repetition, and arousal modulations upon the sensory area processing reflected in N100.{{Cite journal

| doi = 10.1016/S0301-0082(98)00011-2

| last1 = Coull | first1 = J. T.

| title = Neural correlates of attention and arousal: Insights from electrophysiology, functional neuroimaging and psychopharmacology

| journal = Progress in Neurobiology

| volume = 55

| issue = 4

| pages = 343–361

| year = 1998

| pmid = 9654384

| s2cid = 26194262 }} [http://sites.univ-provence.fr/lnc/intranet/user/biblio/images/ProgNeurobiol98.pdf PDF]

Another top-down influence upon N100 has been suggested to be efference copies from a person's intended movements so that the stimulation that results from them are not processed.{{Cite journal

| doi = 10.1016/j.neures.2003.09.008

| last1 = Kudo | first1 = N.

| last2 = Nakagome | first2 = K.

| last3 = Kasai | first3 = K.

| last4 = Araki | first4 = T.

| last5 = Fukuda | first5 = M.

| last6 = Kato | first6 = N.

| last7 = Iwanami | first7 = A.

| title = Effects of corollary discharge on event-related potentials during selective attention task in healthy men and women

| journal = Neuroscience Research

| volume = 48

| issue = 1

| pages = 59–64

| year = 2004

| pmid = 14687881

| s2cid = 37957344 }} A person's own voice produces a reduced N100 as does the effect of a self-initiated compared to externally created perturbation upon balance.{{Cite journal

| last1 = Mochizuki | first1 = G.

| last2 = Sibley | first2 = K. M.

| last3 = Cheung | first3 = H. J.

| last4 = McIlroy | first4 = W. E.

| title = Cortical activity prior to predictable postural instability: Is there a difference between self-initiated and externally-initiated perturbations?

| doi = 10.1016/j.brainres.2009.04.050

| journal = Brain Research

| volume = 1279

| pages = 29–36

| year = 2009

| pmid = 19422812

| pmc =

| s2cid = 12170405

}}

The N100 is a slow-developing evoked potential. From one to four years of age, a positive evoked potential, P100, is the predominant peak.{{Cite journal

| doi = 10.1097/00001756-200201210-00014

| last1 = Kushnerenko | first1 = E.

| last2 = Ceponiene | first2 = R.

| last3 = Balan | first3 = P.

| last4 = Fellman | first4 = V.

| last5 = Huotilaine | first5 = M.

| last6 = Näätäne | first6 = R.

| title = Maturation of the auditory event-related potentials during the first year of life

| journal = NeuroReport

| volume = 13

| issue = 1

| pages = 47–51

| year = 2002

| pmid = 11924892

| s2cid = 33934033 }} Older children start to develop a negative evoked potential at 200 ms that dominates evoked potentials until adolescence;{{Cite journal

| doi = 10.1016/S1388-2457(99)00259-X

| last1 = Pang | first1 = E. W.

| last2 = Taylor | first2 = M. J.

| title = Tracking the development of the N1 from age 3 to adulthood: An examination of speech and non-speech stimuli

| journal = Clinical Neurophysiology

| volume = 111

| issue = 3

| pages = 388–397

| year = 2000

| pmid = 10699397

| s2cid = 37029252 }} this potential is identical to the adult N100 in scalp topography and elicitation, but with a much later onset. The magnetic M100 (measured by MEG rather than EEG) is, likewise, less robust in children than in adults.{{Cite journal

| doi = 10.1097/00004691-199503000-00008

| last1 = Paetau | first1 = R.

| last2 = Ahonen | first2 = A.

| last3 = Salonen | first3 = O.

| last4 = Sams | first4 = M.

| title = Auditory evoked magnetic fields to tones and pseudowords in healthy children and adults

| journal = Journal of Clinical Neurophysiology

| volume = 12

| issue = 2

| pages = 177–185

| year = 1995

| pmid = 7797632

| s2cid = 33059979 }} An adult-like N100-P200 complex only develops after 10 years of age.{{Cite journal

| doi = 10.1097/00004691-199207010-00007

| last1 = Shibasaki | first1 = H.

| last2 = Miyazaki | first2 = M.

| title = Event-related potential studies in infants and children

| journal = Journal of Clinical Neurophysiology

| volume = 9

| issue = 3

| pages = 408–418

| year = 1992

| pmid = 1517407

}}

The various types of N100 mature at different times. Their maturation also varies with the side of the brain: N100a in the left hemisphere is mature before three years of age but this does not happen in the right hemisphere until seven or eight years of age.

The N100 may be used to test for abnormalities in the auditory system where verbal or behavioral responses cannot be used,{{Cite journal

| doi = 10.1159/000259253

| last1 = Hyde | first1 = M.

| title = The N1 response and its applications

| journal = Audiology and Neuro-Otology

| volume = 2

| issue = 5

| pages = 281–307

| year = 1997

| pmid = 9390837

}} such with individuals in coma; in such cases, it can help predict the probability of recovery.{{Cite journal

| doi = 10.1159/000013880

| last1 = Fischer | first1 = C.

| last2 = Morlet | first2 = D.

| last3 = Giard | first3 = M.

| title = Mismatch negativity and N100 in comatose patients

| journal = Audiology and Neuro-Otology

| volume = 5

| issue = 3–4

| pages = 192–197

| year = 2000

| pmid = 10859413

| s2cid = 42959451 }}{{Cite journal

| last1 = Fischer | first1 = C.

| last2 = Luauté | first2 = J.

| last3 = Adeleine | first3 = P.

| last4 = Morlet | first4 = D.

| title = Predictive value of sensory and cognitive evoked potentials for awakening from coma

| journal = Neurology

| volume = 63

| issue = 4

| pages = 669–673

| year = 2004

| pmid = 15326240 | doi=10.1212/01.wnl.0000134670.10384.e2

| s2cid = 31825723

}} Another application is in assessing the optimal level of sedation in intensive critical care.{{Cite journal

| last1 = Yppärilä | first1 = H.

| last2 = Nunes | first2 = S.

| last3 = Korhonen | first3 = I.

| last4 = Partanen | first4 = J.

| last5 = Ruokonen | first5 = E.

| title = The effect of interruption to propofol sedation on auditory event-related potentials and electroencephalogram in intensive care patients

| journal = Critical Care

| volume = 8

| issue = 6

| pages = R483–R490

| year = 2004

| doi = 10.1186/cc2984

| pmid = 15566595

| pmc =1065074

| doi-access = free

}}

High density mapping of the location of the generators of M100 is being researched as a means of presurgical neuromapping needed for neurosurgery.{{Cite journal

| last1 = Cheyne | first1 = D.

| last2 = Bostan | first2 = A. C.

| last3 = Gaetz | first3 = W.

| last4 = Pang | first4 = E. W.

| title = Event-related beamforming: A robust method for presurgical functional mapping using MEG

| doi = 10.1016/j.clinph.2007.05.064

| journal = Clinical Neurophysiology

| volume = 118

| issue = 8

| pages = 1691–1704

| year = 2007

| pmid = 17587643

| pmc =

| s2cid = 5900519

}}

Many cognitive or other mental impairments are associated with changes in the N100 response, including the following:

• There is some evidence that the N100 is affected in those with dyslexia and specific language impairment.Shaul S. (2007). Evoked response potentials (ERPs) in the study of dyslexia: A review. pp. 51–91. In (Breznitz Z. Editor) Brain Research in Language. Springer {{ISBN|978-0-387-74979-2}}
• The sensory gating effect upon N100 with paired clicks is reduced in those with schizophrenia.
• In individuals with tinnitus, those with smaller N100 are less distressed than those with larger amplitudes.{{Cite journal

| last1 = Delb | first1 = W.

| last2 = Strauss | first2 = D. J.

| last3 = Low | first3 = Y. F.

| last4 = Seidler | first4 = H.

| last5 = Rheinschmitt | first5 = A.

| last6 = Wobrock | first6 = T.

| last7 = d’Amelio | first7 = R.

| doi = 10.1007/s10484-008-9065-y

| title = Alterations in Event Related Potentials (ERP) Associated with Tinnitus Distress and Attention

| journal = Applied Psychophysiology and Biofeedback

| volume = 33

| issue = 4

| pages = 211–221

| year = 2008

| pmid = 18836827

| pmc =

| doi-access = free

}}

• Migraine is associated with an increase rather than decrease in N100 amplitude with repetition of the high-intensity stimulation.{{Cite journal

| last1 = Wang | first1 = W.

| last2 = Timsit-Berthier | first2 = M.

| last3 = Schoenen | first3 = J.

| title = Intensity dependence of auditory evoked potentials is pronounced in migraine: An indication of cortical potentiation and low serotonergic neurotransmission?

| journal = Neurology

| volume = 46

| issue = 5

| pages = 1404–1409

| year = 1996

| pmid = 8628490

| doi=10.1212/wnl.46.5.1404

| s2cid = 2645081

}}

• Headache sufferers also have more reactive N100 to somatosensory input than nonsufferers{{Cite journal

| last1 = Marlowe | first1 = N.

| title = Somatosensory evoked potentials and headache: A further examination of the central theory

| journal = Journal of Psychosomatic Research

| volume = 39

| issue = 2

| pages = 119–131

| year = 1995

| pmid = 7595870

| doi=10.1016/0022-3999(94)00072-d

}}

The N100 is 10 to 20% larger than normal when the auditory stimulus is synchronized with the diastolic phase of the cardiac blood pressure pulse.{{Cite journal

| doi = 10.1126/science.6729458

| last1 = Sandman | first1 = C. A.

| last2 = O'Halloran | first2 = J. P.

| last3 = Isenhart | first3 = R.

| title = Is there an evoked vascular response?

| journal = Science

| volume = 224

| issue = 4655

| pages = 1355–1357

| year = 1984

| pmid = 6729458

| bibcode = 1984Sci...224.1355S | url = http://www.escholarship.org/uc/item/1889h4km }}

The Mismatch negativity (MMN) is an evoked potential that occurs at roughly the same time as N100 in response to rare auditory events. It differs from the N100 in that:

• They are generated in different locations.{{Cite journal

| last1 = Alho | first1 = K.

| title = Cerebral generators of mismatch negativity (MMN) and its magnetic counterpart (MMNm) elicited by sound changes

| journal = Ear and Hearing

| volume = 16

| issue = 1

| pages = 38–51

| year = 1995

| pmid = 7774768

| doi=10.1097/00003446-199502000-00004

| s2cid = 31698419

}}

• The MMN occurs too late to be an N100.{{Cite journal

| last1 = Näätänen | first1 = R.

| last2 = Alho | first2 = K.

| title = Mismatch negativity—a unique measure of sensory processing in audition

| journal = The International Journal of Neuroscience

| volume = 80

| issue = 1–4

| pages = 317–337

| year = 1995

| pmid = 7775056

| doi=10.3109/00207459508986107

}}

• The MMN, unlike N100, may be elicited by stimulus omissions (i.e., not hearing a stimulus when you expect to hear one).{{Cite journal

| last1 = Yabe | first1 = H.

| last2 = Tervaniemi | first2 = M.

| last3 = Sinkkonen | first3 = J.

| last4 = Huotilainen | first4 = M.

| last5 = Ilmoniemi | first5 = R. J.

| last6 = Näätänen | first6 = R.

| title = Temporal window of integration of auditory information in the human brain

| journal = Psychophysiology

| volume = 35

| issue = 5

| pages = 615–619

| year = 1998

| pmid = 9715105 | doi=10.1017/s0048577298000183

}}

Though this suggests that they are separate processes, arguments have been made that this is not necessarily so and that they are created by the "relative activation of multiple cortical areas contributing to both of these 'components'".{{Cite journal

| last1 = May | first1 = P. J.

| last2 = Tiitinen | first2 = H.

| title = The MMN is a derivative of the auditory N100 response

| journal = Neurology & Clinical Neurophysiology

| volume = 2004

| pages = 20

| year = 2004

| pmid = 16012601

}}

Pauline A. Davis at Harvard University first recorded the wave peak now identified with N100.Davis PA. (1939). Effects of acoustic stimuli on the waking human brain. J Neurophysiol 2: 494–499 [http://jn.physiology.org/cgi/content/citation/2/6/494 abstract] The present use of the N1 to describe this peak originates in 1966{{cite journal|pmid=5904525|year=1966|last1=Davis|first1=H|title=Acoustic relations of the human vertex potential|journal=The Journal of the Acoustical Society of America|volume=39|issue=1|pages=109–16|last2=Zerlin|first2=S|doi=10.1121/1.1909858|bibcode=1966ASAJ...39..109D}} and N100 later in the mid 1970s.{{Cite journal

| last1 = Donchin | first1 = E.

| last2 = Tueting | first2 = P.

| last3 = Ritter | first3 = W.

| last4 = Kutas | first4 = M.

| last5 = Heffley | first5 = E.

| title = On the independence of the CNV and the P300 components of the human averaged evoked potential

| journal = Electroencephalography and Clinical Neurophysiology

| volume = 38

| issue = 5

| pages = 449–461

| year = 1975

| pmid = 50170 | doi=10.1016/0013-4694(75)90187-x

}} The origin of the wave for a long time was unknown and only linked to the auditory cortex in 1970.{{Cite journal

| last1 = Vaughan Jr | first1 = H. G.

| last2 = Ritter | first2 = W.

| title = The sources of auditory evoked responses recorded from the human scalp

| journal = Electroencephalography and Clinical Neurophysiology

| volume = 28

| issue = 4

| pages = 360–367

| year = 1970

| pmid = 4191187

| doi=10.1016/0013-4694(70)90228-2

}}

Due to magnetoencephalography, research is increasingly done upon M100, the magnetic counterpart of the electroencephalographic N100. Unlike electrical fields which face the high resistance of the skull and generate secondary or volume currents, magnetic fields which are orthogonal to them have a homogeneous permeability through the skull. This enables the location of sources generating fields that are tangent to the head surface with an accuracy of a few millimeters.Hämäläinen M, Hari R, Ilmoniemi RJ, Knuutila J. (1993). Magnetoencephalography-theory, instrumentation, and applications to noninvasive studies of the working human brain. Reviews of modern Physics. 65: 413–497. {{OCLC|197237696}} New techniques, such as event-related beam-forming with magnetoencephalography, allow sufficiently accurate location of M100 sources to be clinically useful for preparing surgery upon the brain.

{{div col|colwidth=22em}}

• Bereitschaftspotential
• C1 and P1
• Contingent negative variation
• Difference due to memory
• Early left anterior negativity
• Error-related negativity
• Late positive component
• Lateralized readiness potential
• Mismatch negativity
• N2pc
• N170
• N200
• N400
• P3a
• P3b
• P200
• P300 (neuroscience)
• P600
• Somatosensory evoked potential
• Visual N1

{{div col end}}

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Category:Electroencephalography

Category:Evoked potentials