Infants’ brain responses for speech sound changes in fast multifeature MMN paradigm

ObjectiveWe investigated whether newborn speech-sound discrimination can be studied in 40 min using fast multifeature mismatch negativity (MMN) paradigm and do the results differ from those obtained with the traditional oddball paradigm.MethodsNewborns’ MMN responses to five types of changes (consonant identity, F0, intensity, vowel duration and vowel identity) were recorded in the multifeature group (N = 15) and vowel duration and vowel identity changes in the oddball group (N = 13), after which the MMNs from both groups were compared with each others.ResultsStatistically significant MMNs in the 190–600 ms time range from the stimulus onset were found for most change types in both paradigms. Newborn MMN responses were predominantly positive but a small number of participants elicited negative MMNs instead. MMN amplitudes did not differ between the multifeature and oddball groups.ConclusionsNewborn speech-sound discrimination can be assessed in a short recording time using the fast multifeature paradigm.SignificanceThe paradigm presented here can be used to record extensive auditory discrimination profiles in newborns and assess development of speech-sound discrimination and its difficulties.     

Speech-feature discrimination in children with Asperger syndrome as determined with the multi-feature mismatch negativity paradigm

ObjectiveAsperger syndrome, belonging to the autistic spectrum of disorders, involves deficits in social interaction and prosodic use of language but normal development of formal language abilities. Auditory processing involves both hyper- and hypoactive reactivity to acoustic changes.MethodsResponses composed of mismatch negativity (MMN) and obligatory components were recorded for five types of deviations in syllables (vowel, vowel duration, consonant, syllable frequency, syllable intensity) with the multi-feature paradigm from 8–12-year old children with Asperger syndrome.ResultsChildren with Asperger syndrome had larger MMNs for intensity and smaller MMNs for frequency changes than typically developing children, whereas no MMN group differences were found for the other deviant stimuli. Furthermore, children with Asperger syndrome performed more poorly than controls in Comprehension of Instructions subtest of a language test battery.ConclusionsCortical speech-sound discrimination is aberrant in children with Asperger syndrome. This is evident both as hypersensitive and depressed neural reactions to speech-sound changes, and is associated with features (frequency, intensity) which are relevant for prosodic processing.SignificanceThe multi-feature MMN paradigm, which includes variation and thereby resembles natural speech hearing circumstances, suggests abnormal pattern of speech discrimination in Asperger syndrome, including both hypo- and hypersensitive responses for speech features.     

The right profile: mismatch negativity in schizophrenia with and without auditory hallucinations as measured by a multi-feature paradigm.

ObjectiveTo examine pre-attentive acoustic change detection in schizophrenia patients with and without auditory hallucinations via mismatch negativity (MMN) extracted from a multi-feature paradigm.MethodsThis study examined the electroencephalograph (EEG)-derived MMN, recorded across 32 sites, in 12 hallucinating patients (HPs) with schizophrenia, 12 non-hallucinating patients (NPs) with schizophrenia and 12 healthy controls (HCs). MMN was recorded in response to a multi-feature MMN paradigm [Näätänen, R., et al., 2004. The mismatch negativity (MMN): towards the optimal paradigm. Clin. Neurophys. 115, 140–144] which employs frequency, duration, intensity, location and gap deviants. Differences in source localization were probed using standardized low resolution brain electromagnetic tomography (sLORETA).ResultsHPs showed significantly smaller MMNs to duration deviants compared to HCs and NPs, as well as smaller MMNs to intensity deviants compared to HCs. Regionalized differences between HCs and each of the patient groups were observed in response to frequency deviants. There were no significant group effects for location or gap deviants, or for MMN latency. Source localization using sLORETA showed no significant differences in MMN generator location across groups for any of the deviant stimuli.ConclusionsThe often-reported robust MMN deficit to duration deviants may be specific to schizophrenia patients afflicted with auditory hallucinations. Furthermore, by using symptom-specific groups, novel deficits of pre-attentive auditory processing, such as that observed to intensity deviants in HPs, may be revealed.SignificanceThe differential responding observed between both groups of patients with schizophrenia has implications for automatic processing within the auditory cortex of hallucinating patients and suggests that care must be taken when recruiting participants in studies involving schizophrenia to ensure consistent, replicable results.     

Early integration of vowel and pitch processing: A mismatch negativity study

ObjectiveSeveral studies have explored the processing specificity of music and speech, but only a few have addressed the processing autonomy of their fundamental components: pitch and phonemes. Here, we examined the additivity of the mismatch negativity (MMN) indexing the early interactions between vowels and pitch when sung.MethodsEvent-related potentials (ERPs) were recorded while participants heard frequent sung vowels and rare stimuli deviating in pitch only, in vowel only, or in both pitch and vowel. The task was to watch a silent movie while ignoring the sounds.ResultsAll three types of deviants elicited both an MMN and a P3a ERP component. The observed MMNs were of similar amplitude for the three types of deviants and the P3a was larger for double deviants. The MMNs to deviance in vowel and deviance in pitch were not additive.ConclusionsThe underadditivity of the MMN responses suggests that vowel and pitch differences are processed by interacting neural networks.SignificanceThe results indicate that vowel and pitch are processed as integrated units, even at a pre-attentive level. Music-processing specificity thus rests on more complex dimensions of music and speech.     

Children’s brain responses to sound changes in pseudo words in a multifeature paradigm

ObjectiveThe multifeature mismatch negativity (MMN) paradigm has previously been used to study MMN responses to changes in tones or isolated syllables. We tested 4–12 year old children’s MMNs to changes in a naturally produced pseudo word context.MethodsWe studied preschoolers’ (under the age of 7 years, N = 15, mean age 5 years 4 months) and school childrens’ (over the age of 7 years, N = 15, mean age 9 years 3 months) MMNs to five types of changes (vowel duration, fundamental frequency, gap, intensity, vowel identity) in the middle syllable of a pseudo word [tɑtɑtɑ] using a multifeature paradigm.ResultsVowel duration and gap changes elicited larger frontocentral MMN responses than other change types and the vowel identity change also produced an early positive p-MMR. The presence of the MMN was also determined at the individual level, and it was found that vowel duration and gap deviants produced MMNs in most of the participants.ConclusionsThe current study shows that children’s neural speech sound discrimination can be assessed in a word context in a short recording time (30 min) by using the multifeature paradigm.SignificanceA paradigm which can be used to investigate the discrimination of several change types of speech-sounds in a natural context can be useful for investigating speech development and deficits.     

Measurement of extensive auditory discrimination profiles using the mismatch negativity (MMN) of the auditory event-related potential (ERP)

ObjectiveMismatch negativity (MMN), a change-specific component of the auditory event-related potential (ERP), is sensitive to deficits in central auditory processing associated with many clinical conditions. The aim of this study was to obtain a comprehensive multi-dimensional profile of central auditory processing by extending the recently developed fast multi-feature MMN paradigm [Näätänen R, Pakarinen S, Rinne T, Takegata R. The mismatch negativity (MMN): towards the optimal paradigm. Clin Neurophysiol 2004;115:140–144].MethodsMMN responses to changes in sound duration, frequency, intensity, and perceived sound-source location at six different magnitudes of deviation were recorded from healthy young adults by using the multi-feature MMN paradigm. In addition, behavioural discrimination accuracy and speed were measured to examine the relationship between MMN and behavioural performance.ResultsAll the 24 sound changes elicited significant MMNs. MMN amplitude increased and latency decreased with increasing magnitude of sound change. Furthermore, the MMN amplitude and latency predicted the subjects’ accuracy and speed in detecting these deviations.ConclusionsThis new paradigm provides an extensive auditory discrimination profile for several auditory attributes at different deviation magnitudes in a minimal recording time.SignificanceThe auditory discrimination profiles can offer a comprehensive view of the development, plasticity, and deficits of central auditory processing.     

The mismatch negativity (MMN) with no standard stimulus

ObjectiveThe recent fast multi-feature mismatch negativity (MMN) paradigms rest on the assumption that the deviant stimuli, alternating with the standard tone, strengthen the memory trace of the standard in respect to those attributes they have in common. In the present study, we tested whether the MMN can be recorded even without the standard stimulus, with the invariant properties of the deviant stimuli serving as a standard against which to detect the sound changes.MethodsMMN was recorded for changes in sound duration, frequency, intensity, location, gap, brightness, density, and noise level in a new multi-feature paradigm where no standard stimuli were used. In addition, these MMNs were compared with those recorded in the conventional multi-feature paradigm.ResultsAll sound changes elicited significant MMN responses that were highly similar between paradigms.ConclusionsThe MMN can be recorded even without the standard stimulus, as an accurate memory trace is constructed for the invariant features of the auditory input.SignificanceOmitting the standard stimuli results in almost 50% shorter recording time and the larger selection of deviant types with the newly introduced brightness, density, and noise-level changes provides even more information on the individual perceptual profiles than conventional multi-feature paradigms.     

Mismatch Negativity (MMN) evoked by sound duration contrasts: An unexpected major effect of deviance direction on amplitudes

ObjectiveVerify and explore unexpected results suggesting an effect of deviance direction (shorter or longer deviants) on the amplitude of MMNs evoked by sound duration contrasts.MethodsMMNs were recorded using the oddball paradigm on ten adults. Four standard stimulus durations (100, 150, 200 and 250 ms) were used and deviants were 50% shorter or longer. Behavioral data (hit rates, d′, and reaction times) were collected after the electrophysiological sessions.ResultsMMNs were larger for short than for long deviants. There was no effect on MMN latencies. Hit rates and d′ data were almost at ceiling level for all conditions even for the longest standard – long deviant combination in which the MMN was abolished.ConclusionsWe argue that the deviance direction effect on MMN amplitudes can be explained by the delay between the moment of deviance detection and the end of the deviance quantification process.SignificanceA major effect of deviance direction on amplitudes was confirmed. This effect, which was confined to electrophysiological data, is to be taken into account when using duration contrasts to probe the processing of temporal information.     

Deficit in the preattentive processing of syllabic duration and VOT in children with dyslexia

The aim of this experiment was to examine the preattentive processing of syllables in 9-11-year-old children with dyslexia and matched controls using the Mismatch Negativity (MMN), an auditory Event-Related brain potential (ERP) related to preattentive discrimination. Children were presented with a sequence of syllables that included standards (the syllable "Ba") and deviants in vowel frequency, vowel duration and Voice Onset Time (VOT) that were either close to or far from the standard (Small and Large deviants). No between-group differences were found for frequency deviants. However, whilst normal-reading children showed larger MMNs to Large than to Small deviants in vowel duration and VOT, no such deviance size effect was found in children with dyslexia. These results are taken to indicate that the preattentive processing of vowel duration and VOT is impaired in children with dyslexia, with no impairment in the processing of vowel frequency deviants. By revealing processing deficits of both duration and VOT deviants, these results suggest a strong link between acoustical and phonological processing.     

Event-related potential indices of auditory vowel processing in 3-year-old children

Objective: To determine the ERP characteristics and ERP indices of central speech sound encoding and discrimination in young children.Methods: Auditory sensory event-related potentials (ERPs) and the ERP index of auditory sensory discrimination (the mismatch negativity, MMN) were elicited by vowel stimuli in 3-year-old children. In an oddball paradigm, the standard stimulus was vowel /a/, one deviant stimulus was vowel /o/ (the across-category change), and the other was nasalized vowel /a/ (within-category change). In addition, the ERP changes occurring during the 14 min uninterrupted recording were examined.Results: As indexed by the sensory P1, N2, and N4 peaks, the 3-year-old children's transient neural encoding of vowels was comparable to that earlier registered in 1-year-old children but also showed vowel-specific characteristics observed in school-age children. The 3-year-old's MMN was comparable in amplitude to the school-age children's MMN and appeared to be sensitive to the across-category aspects of vowel changes. However, its latency was longer in the 3-year-olds than in school-age children. Among the sensory ERPs, only the N4 peak showed significant diminution during the experiment. The across-category change MMN diminished after 10 min of the recording, however, over the frontal areas only.Conclusions: In the 3-year-old children, the sensory processing of vowels exhibited transitional characteristics between those observed in infants and school-age children. The auditory sensory discrimination in the 3-year-olds appeared to be sensitive to the phonemic aspects of stimulus change. The frontally-predominant MMN diminution during the experiment might indicate the greater refractoriness of its frontal-lobe generators. In general, the auditory sensory ERPs show distinct maturational profiles from that of the MMN.     

Domain-specific suppression of auditory mismatch negativity with transcranial direct current stimulation

ObjectiveTo evaluate the influence of frontal transcranial direct current stimulation (tDCS) on auditory mismatch negativity (MMN).MethodsMMN is an event related potential calculated by subtracting the amplitude of the evoked potentials in response to a “standard” stimulus from the evoked potentials produced by a rare “oddball” stimulus. Here we assessed the influence of anodal tDCS, cathodal tDCS or sham stimulation delivered over the right inferior frontal cortex on MMN in response to duration and frequency auditory deviants in 10 healthy subjects.ResultsMMN to frequency deviants was significantly reduced after anodal tDCS compared with sham or cathodal stimulation which did not change MMN to frequency deviants. Neither anodal nor cathodal tDCS had any effect on MMN to duration deviants.ConclusionsNon-invasive brain stimulation with tDCS can influence MMN. The differing networks known to be activated by duration and frequency deviants could account for the differential effect of tDCS on duration and frequency MMN.SignificanceNon-invasive brain stimulation could be a useful method to manipulate MMN for experimental purposes.     

An extensive pattern of atypical neural speech-sound discrimination in newborns at risk of dyslexia

ObjectiveIdentifying early signs of developmental dyslexia, associated with deficient speech-sound processing, is paramount to establish early interventions. We aimed to find early speech-sound processing deficiencies in dyslexia, expecting diminished and atypically lateralized event-related potentials (ERP) and mismatch responses (MMR) in newborns at dyslexia risk.MethodsERPs were recorded to a pseudoword and its variants (vowel-duration, vowel-identity, and syllable-frequency changes) from 88 newborns at high or no familial risk. The response significance was tested, and group, laterality, and frontality effects were assessed with repeated-measures ANOVA.ResultsAn early positive and right-lateralized ERP component was elicited by standard pseudowords in both groups, the response amplitude not differing between groups. Early negative MMRs were absent in the at-risk group, and MMRs to duration changes diminished compared to controls. MMRs to vowel changes had significant laterality × group interactions resulting from right-lateralized MMRs in controls.ConclusionsThe MMRs of high-risk infants were absent or diminished, and morphologically atypical, suggesting atypical neural speech-sound discrimination.SignificanceThis atypical neural basis for speech discrimination may contribute to impaired language development, potentially leading to future reading problems.     

Memory-based mismatch response to changes in duration of auditory stimuli: An MEG study

ObjectiveDifferences in physical features and occurrence probability between standards and deviants in oddball paradigms provide contributions to magnetic mismatch negativity (MMNm). We aimed to reduce these influential factors and extract memory-based MMNm by adding a control paradigm.MethodsMagnetoencephalographic responses were recorded in 13 healthy adults with an oddball paradigm (125-ms standard and 50-ms deviant tones) and an equiprobable control paradigm (50-ms control and four other duration-varying tones). The stimulus onset asynchrony was 500 ms. Controlled MMNm was obtained by subtracting control-evoked responses from deviant-evoked responses.ResultsWith respect to the onset of stimulus difference, the peak latency of controlled MMNm was compatible with previous intracranial MMN recordings. Both controlled and traditional MMNm were generated around the superior temporal cortex, whereas the controlled MMNm amplitude was about 70% of traditional MMNm amplitude. Right-hemispheric dominance was observed in traditional MMNm but not in controlled MMNm. N100m amplitude was smaller in standard-evoked than in deviant- or control-evoked responses.ConclusionsControlled MMNm reflects memory-based processing of duration changes, whereas traditional MMNm additionally involves non-memory activations related to differential refractoriness states and physical properties between standard and deviant stimuli.SignificanceThe memory-based processing of auditory deviants may be preferentially extracted by adding a control paradigm.     

Event-related potential features indexing central auditory discrimination by newborns

Behavioral research has produced little evidence on sound feature discrimination in neonates. Sensory processes underlying sound perception can be studied using the mismatch negativity (MMN) component of auditory event-related potentials (ERPs), which is not contingent on conscious perception and response. Thus, MMN is suitable for studying newborns, who are difficult to obtain behavioral responses from. The present study thus utilized spectrally rich sounds, known to elicit the most replicable MMN in adults, to investigate newborns' preattentive analysis of sound duration and frequency changes. An attempt was also made to control for the obligatory ERP effects on the MMN. Three-partial harmonic tones were presented in Duration and in Frequency oddball conditions to 55 newborns. In the other two, Equiprobable duration and Equiprobable frequency, conditions frequency and duration deviants of the oddball paradigms were presented with equal probabilities among sounds of other durations and frequencies. MMN was elicited in 81% of newborns in Frequency oddball condition and in 78% of newborns in Duration oddball condition. No significant amplitude differences between the duration and frequency MMNs were found, but MMN latency was delayed in Duration condition. The obligatory components seemed to contribute significantly to the deviant-standard difference in Duration but not in Frequency condition. The majority of neonates appear to possess effective sound frequency and duration discrimination mechanisms. Their preattentive sound discrimination is facilitated by spectrally rich sound content. The present findings support a change-detection nature of MMN in neonates; however, sound duration-related obligatory effects need to be taken into account in infant MMN studies.     

Nicotine and the hallucinating brain: effects on mismatch negativity (MMN) in schizophrenia

Elevated smoking rates have been noted in schizophrenia, and it has been hypothetically attributed to nicotine's ameliorating abnormal brain processes in this illness. There is some preliminary evidence that nicotine may alter pre-attentive auditory change detection, as indexed by the EEG-derived mismatch negativity (MMN), but no previous study has examined what role auditory verbal hallucinations (AVH) may have on these effects. The objective of this study was to examine MMN-indexed acoustic change detection in schizophrenia (SZ) following nicotine administration and elucidate its association with AVH. Using a modified multi-feature paradigm, MMNs to duration, frequency and intensity deviants were recorded in 12 schizophrenia outpatients (SZ) with persistent AVHs following nicotine (6mg) and placebo administration. Electrical activity was recorded from 32 scalp electrodes; MMN amplitudes and latencies for each deviant were compared between treatments and were correlated with trait (PSYRATS) and state measures of AVH severity and Positive and Negative Syndrome Scale (PANSS) ratings. Nicotine administration resulted in a shortened latency for intensity MMN. Additionally, nicotine-related change in MMN amplitude was correlated with nicotine-related change in subjective measures of hallucinatory state. In summary, nicotine did not affect MMN amplitudes in schizophrenia patients with persistent AVHs, however this study reports accelerated auditory change detection to intensity deviants with nicotine in this group. Additionally, nicotine appeared to induce a generalized activation of the auditory cortex in schizophrenia, resulting in a concurrent increase in intensity MMN amplitude and subjective clarity of AVHs.     

Emotional MMN: Anxiety and heart rate correlate with the ERP signature for auditory change detection

ObjectivePrevious work established the mismatch negativity (MMN) as a correlate of pre-attentive auditory change detection. The present study aimed at investigating the relationship between the MMN and emotional processes associated with the detection of change.MethodsTo this end, we assessed state anxiety with a questionnaire and subsequently recorded the electroencephalogram (EEG) and heart rate while participants watched a silent movie and listened to a task-irrelevant auditory oddball sequence. The oddball sequence comprised meaningless syllables of which some were deviants spoken with an angry or neutral voice.ResultsThe MMN to angry voice deviants was larger than that to neutral deviants and correlated positively with ensuing heart rate acceleration. Additionally, both the MMN and heart rate acceleration to angry voice deviants were increased with increasing state anxiety. A similar effect for neutral voice deviants was non-significant.ConclusionTaken together, these results suggest that the pre-attentive processing of threat, as reflected by the MMN, is linked to an activation of the sympathetic nervous system. Moreover, this link is more strongly activated in individuals with high state anxiety.SignificanceThus, the MMN may be used as a marker for an individual’s state dependent sensitivity to unattended, emotionally relevant change.     

New fast mismatch negativity paradigm for determining the neural prerequisites for musical ability

Studies have consistently shown that the mismatch negativity (MMN) for different auditory features correlates with musical skills, and that this effect is more pronounced for stimuli integrated in complex musical contexts. Hence, the MMN can potentially be used for determining the development of auditory skills and musical expertise. MMN paradigms, however, are typically very long in duration, and far from sounding musical. Therefore, we developed a novel multi-feature MMN paradigm with 6 different deviant types integrated in a complex musical context of no more than 20 min in duration. We found significant MMNs for all 6 deviant types. Hence, this short objective measure can putatively be used as an index for auditory and musical development.     

Mismatch negativity to different deviant changes in autism spectrum disorders: A meta-analysis

ObjectiveMismatch negativity (MMN) has been continuously used to evaluate the functional integrity of central auditory processing. However, it still remains inconclusive whether patients with autism spectrum disorder (ASD) demonstrate reduced MMN responses in all deviant types.MethodsTo reconcile the previous controversial findings, we performed a meta-analysis of peer-reviewed MMN articles concerning ASD. The potential moderators regarding different deviant types, diagnosis, and age on the effect sizes (Hedges’ g) were also assessed.ResultsCompared to the controls, ASD patients showed reduced MMN amplitudes (g = −0.37, p = 0.001) and prolonged latencies (g = −0.33, p = 0.041) in response to speech-sound deviants. Children/adolescents with ASD manifested reduced MMN amplitudes in response to tone-duration deviants (g = −0.46, p = 0.014). Furthermore, the results showed significantly shortened MMN latencies to tone-frequency deviants in patients with autism (g = 0.29, p = 0.038) and, in contrast, prolonged MMN latencies (g = −0.74, p = 0.001) in patients with Asperger syndrome.ConclusionMMN deficits are robust in ASD patients, suggesting an altered central ability in auditory discrimination.SignificanceMMN alterations were displayed in different profiles with respect to frequency, duration and phoneme changes.     

Alterations of mismatch negativity (MMN) in schizophrenia patients with auditory hallucinations experiencing acute exacerbation of illness

Auditory verbal hallucinations (AHs), or hearing 'voices', are one of the hallmark symptoms of patients with schizophrenia. The primary objective of this study was to compare hallucinating schizophrenia patients with respect to differences in deviance detection, as indexed by the auditory mismatch negativity (MMN). Patients were recruited during an acute psychotic episode requiring hospitalization, during which time symptoms of psychosis, including auditory hallucinations, are likely to be at their most severe. MMNs to duration, frequency, gap, intensity and location deviants (as elicited by the 'optimal' multi-feature paradigm) were recorded in 12 acutely ill schizophrenia patients (SZ) with persistent AHs and 15 matched healthy controls (HC). Electrical activity was recorded from 32 scalp electrodes. MMN amplitudes and latencies for each deviant were compared between groups and were correlated with trait (PSYRATS) and state measures of AH severity and Positive and Negative Syndrome Scale (PANSS) ratings in SZs. There were significant group differences for duration, gap, intensity and location MMN amplitudes, such that SZs exhibited reduced MMNs compared to HCs. Additionally, gap MMN amplitudes were correlated with measures of hallucinatory state and frequency of AHs, while location MMN was correlated with perceived location of AHs. In summary, this study corroborates previous research reporting a robust duration MMN deficit in schizophrenia, as well as reporting gap, intensity and location MMN deficits in acutely ill schizophrenia patients with persistent AHs. Additionally, MMN amplitudes were correlated with state and trait measures of AHs. These findings offer further support to previous work suggesting that the presence of auditory hallucinations may make a significant contribution to the widely reported MMN deficits in schizophrenia.     

Discrimination of auditory motion patterns: The mismatch negativity study

The aim of the present study is to test whether mismatch negativity (MMN) response can be elicited by changes in auditory motion dynamics. The discrimination of auditory motion patterns was investigated using psychophysical and electrophysiological methods in the same group of subjects. Auditory event-related potentials (ERP) were recorded for stationary midline noises and moving noises shifting to the left/right from the head midline. Two patterns of auditory motion were used with gradual (Motion) and stepwise (Step) movements which started and ended at the same loci. Auditory motion was produced by linear and abrupt changes of interaural time differences (ITD) in binaurally presented stimuli. In Experiment 1, ERPs were recorded for stationary midline standards and for Motion and Step deviants. It was found that Step deviants result in larger MMN amplitudes than Motion deviants with the same distance travelled, which implies that information contained in the stimulus midportion could be involved in the processing of the auditory motion. The threshold ITD values for the detection of Step and Motion stimuli displacement obtained during psychoacoustic tests were greater than the minimal ITD changes which elicited significant MMN. Experiment 2 demonstrated that Step deviants elicited significant MMNs in the context of Motion standards, although these stimuli could not be discriminated behaviourally. MMNs elicited by Step deviants in different acoustic contexts are discussed from the viewpoint of different brain processes underlying the discrimination of the abrupt ITD change. These results suggest that the early cortical mechanism of auditory motion processing reflected by MMN could not be considered as a spatial discriminator of the onset/offset stimulus positions, that is, a simple onset-offset detector. Combining psychoacoustic data with MMN results we may conclude that motion discrimination in auditory system might be better at the preattentive level.