Mismatch Negativity Peak Research Articles

Comparison of dry and wet electroencephalography for the assessment of cognitive evoked potentials and sensor-level connectivity

BackgroundMultipin dry electrodes (dry EEG) provide faster and more convenient application than wet EEG, enabling extensive data collection. This study aims to compare task-related time-frequency representations and resting-state connectivity between wet and dry EEG methods to establish a foundation for using dry EEG in investigations of brain activity in neuropsychiatric disorders.MethodsIn this counterbalanced cross-over study, we acquired wet and dry EEG in 33 healthy participants [n = 22 females, mean age (SD) = 24.3 (± 3.4) years] during resting-state and an auditory oddball paradigm. We computed mismatch negativity (MMN), theta power in task EEG, and connectivity measures from resting-state EEG using phase lag index (PLI) and minimum spanning tree (MST). Agreement between wet and dry EEG was assessed using Bland–Altman bias.ResultsMMN was detectable with both systems in time and frequency domains, but dry EEG underestimated MMN mean amplitude, peak latency, and theta power compared to wet EEG. Resting-state connectivity was reliably estimated with dry EEG using MST diameter in all except the very low frequencies (0.5–4 Hz). PLI showed larger differences between wet and dry EEG in all frequencies except theta.ConclusionDry EEG reliably detected MMN and resting-state connectivity despite a lower signal-to-noise ratio. This study provides the methodological basis for using dry EEG in studies investigating the neural processes underlying psychiatric and neurological conditions.

Automated ABR and MMN extraction using a customized headband for hearing screening

ObjectiveStimuli-elicited EEG responses, known as Event-Related Potentials (ERPs), reflect the health status of underlying electrophysiological processes and are frequently used for scanning sensory pathways. Current ERP extraction systems are expensive, complex, and bulky. This study aims to overcome these limitations by developing and validating a bimodal auditory ERP extractor headband. MethodsAn affordable, portable bimodal auditory ERP extractor was developed and validated for ABR (Auditory Brainstem Response) and MMN (Mismatch Negativity) response interpretation. Auditory stimuli were created using Presentation software. Adaptive filtering-based extraction was performed in EEGLAB (MATLAB) to derive the neural inferences. Extracted responses from n = 5 young adults were validated against CE-certified acquisition systems used in clinical practice. ResultsValidation results showed the grand average responses of ABR and MMN for n = 5 subjects matched. Furthermore, with and without stimuli ERP analysis showed significant differences for identified features (p = 0.00794 for ABR wave-V amplitudes, p = 1.22 * 10−5, and p = 2.62 * 10−5 for MMN peak latencies and area under the curves), ensuring that the response was due to the presented auditory stimuli. ConclusionThe results confirm the competency of the developed system to obtain MMN and ABR from young adults. A clear contrast between latency-amplitude scatter plots further ensures the competency of a developed system to acquire ABR and MMN. SignificanceThe novelty of the study is an easy-to-operate, affordable ERP extractor with adaptive filtering, wearable design, and configurable stimuli. This system can be a potential solution for large-scale hearing screening, providing detailed neural insights, including averaged responses and inter-trial variabilities.

Altered auditory processes pattern predicts cognitive decline in older adults: different modalities with aging.

Cohort studies have shown that older adults with hearing impairment as assessed by self-report or behavioral measures are at higher risk of developing dementia many years later. A fine-grained examination of auditory processing holds promise for more effective screening of older adults at risk of cognitive decline. The auditory mismatch negativity (MMN) measure enables one to gain insights into the neurobiological substrate of central auditory processing. We hypothesized that older adults showing compromised indexes of MMN at baseline would exhibit cognitive decline at the one-year follow-up. We performed cognitive evaluations with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS; Form A and Form B) in 108 community-dwelling older adults and acquired EEG via the classic passive auditory oddball paradigm at baseline and 12-month follow-up. The results showed that young-old adults with future cognitive decline showed a decrease in MMN peak amplitude, accompanied by a forward-shifting latency, whereas in older adults it showed a delay in MMN latency, and unchanged MMN peak amplitude at midline electrodes (Fz, FCz and Cz). Furthermore, the peak amplitude of the MMN decreases with age in older adults aged 70-80 years rather than 60-70 years or > 80 years. The altered MMN model exists in different aging stages and it's a promising electrophysiological predictor of cognitive decline in older adults. In addition, further research is needed to determine the neural mechanisms and potential implications of the accelerated decline in MMN in older adults.

EEG-based Objective Quality Assessment of Interrupted Speech.

As an important dimension of speech degradation, interruption destroys the acoustic waveform information of a speech signal and seriously affects the quality rating in speech perception. Existing studies assessing the quality of interrupted speech mainly focus on subjective methods. This work used event-related potentials (ERPs) to objectively investigate the effects of two interruption factors (i.e., interruption duty cycle and interruption rate) on the perceived quality of the periodically interrupted speech. An oddball-paradigm based ERP experiment was designed, and the periodically interrupted stimuli were presented to participants in the ERP experiment. Meanwhile, participants were instructed to provide their subjective quality ratings of interrupted speech under the same interruption conditions. The experimental results showed that the degree of both interruption duty cycle and interruption rate affected the peak latency of mismatch negativity (MMN) of the collected ERP response, with a smaller MMN peak latency under conditions with a smaller interruption duty cycle or a larger interruption rate. These findings are largely consistent with the subjective quality rating results, suggesting that the peak latency of MMN response can be potentially used as an objective quality indicator of the periodically interrupted speech.

Capturing the attentional response to clinical auditory alarms: An ERP study on priority pulses.

Clinical auditory alarms are often found in hospital wards and operating rooms. In these environments, regular daily tasks can result in having a multitude of concurrent sounds (from staff and patients, building systems, carts, cleaning devices, and importantly, patient monitoring devices) which easily amount to a prevalent cacophony. The negative impact of this soundscape on staff and patients' health and well-being, as well as in their performance, demand for accordingly designed sound alarms. The recently updated IEC60601-1-8 standard, in guidance for medical equipment auditory alarms, proposed a set of pointers to distinctly convey medium or high levels of priority (urgency). However, conveying priority without compromising other features, such as ease of learnability and detectability, is an ongoing challenge. Electroencephalography, a non-invasive technique for measuring the brain response to a given stimulus, suggests that certain Event-Related Potentials (ERPs) components such as the Mismatch Negativity (MMN) and P3a may be the key to uncovering how sounds are processed at the pre-attentional level and how they may capture our attention. In this study, the brain dynamics in response to the priority pulses of the updated IEC60601-1-8 standard was studied via ERPs (MMN and P3a), for a soundscape characterised by the repetition of a sound (generic SpO2 "beep"), usually present in operating and recovery rooms. Additional behavioural experiments assessed the behavioural response to these priority pulses. Results showed that the Medium Priority pulse elicits a larger MMN and P3a peak amplitude when compared to the High Priority pulse. This suggests that, at least for the applied soundscape, the Medium Priority pulse is more easily detected and attended at the neural level. Behavioural data supports this indication, showing significantly shorter reaction times for the Medium Priority pulse. The results pose the possibility that priority pointers of the updated IEC60601-1-8 standard may not be successfully conveying their intended priority levels, which may not only be due to design properties but also to the soundscape in which these clinical alarms are deployed. This study highlights the need for intervention in both hospital soundscapes and auditory alarm design settings.

Altered evoked responses for motor-related words in children with upper limb motor impairments

ObjectiveObstetric brachial plexus palsy (OBPP) and amyoplasia, the classical type of arthrogryposis multiplex congenita, manifest themselves as highly limited mobility of the upper limb. At the same time, according to the embodiment cognition theories, the motor impairments might lead to the alteration of cognitive functions in OBPP/amyoplasia patients. In the current study, we examined whether OBPP/amyoplasia children exhibit altered processing of motor-related verbs. MethodsWe conducted a case-control study using clinical population and control children. Oddball series were used to elicit mismatch negativity (MMN) EEG responses. The series consisted of limb-related verbs (deviant stimuli) and matched pseudowords (standard stimuli). 27 patients and 32 control children were included in the analysis. ResultsWe showed that MMN waveforms differed between OBPP/amyoplasia children and their control peers in the frontal and temporal electrodes when the stimuli contained hand-related verbs. In particular, the MMN peak latency in the OBPP/amyoplasia children was significantly delayed as compared with the healthy controls. At the same time, neither series with leg-related verbs nor series of pseudowords resulted in statistically significant differences. ConclusionsOur findings suggest altered processing of hand-related verbs in OBPP/amyoplasia children with hand-related disabilities. SignificanceOur results contribute to the growing evidence in support of the theory of embodied cognition, which proposes that various domains of cognition are shaped by bodily interactions with the environment.

Audiovisual high variability phonetic training promotes second language lexical tone learning: An event-related potential study

This study investigated the efficacy of a modified high variability phonetic training (HVPT) protocol in second language learning. The target Mandarin lexical tones in the training stimuli were acoustically exaggerated at four levels in terms of duration, pitch range, and pitch contour. Seven audiovisual perceptual training sessions were designed to deliver the training stimuli adaptively based on the listener's identification score. Pre- and post-tests used behavioral identification and discrimination tasks with natural speech, synthetic speech, and non-speech control stimuli. ERP experiments were also conducted with synthetic speech stimuli in a passive listening oddball paradigm. A total of 24 adult monolingual American English speakers were randomly assigned to the training group and control group. Behavioral data showed significant improvement in identifying the four lexical tones in the trainees but not in the controls. There was also training-induced enhancement of categorical perception of the lexical tones for the synthetic speech stimuli. Posttest versus pretest comparison in the trainees showed an increased mismatch negativity (MMN) response with decreased MMN peak latency for the across-category lexical tone stimuli. Collectively, the results demonstrate fundamental neural sensitivity changes at the pre-attentive level underlying training-induced behavioral identification and discrimination changes in second language learners.

Aberrant Frequency Related Change-Detection Activity in Chronic Tinnitus.

Tinnitus is the perception of sound without the occurrence of an acoustic event. The deficit in auditory sensory or echoic memory may be the cause of the perception of tinnitus. This study considered the mismatch negativity (MMN) to investigate the potential difference between and within groups of persons with normal hearing (NH) and tinnitus. Using an auditory multi-feature paradigm to elicit the MMN, this study considered the MMN peak amplitude at two central frequencies for two MMN subcomponents. These central frequencies were 1 and 5 kHz, which the latter was closer to the perceived tinnitus frequency in the group with tinnitus. The deviants were higher frequency, lower frequency, higher intensity, lower intensity, duration, location (left), location (right), and gap. The pure tone audiometry (PTA) test and distortion product otoacoustic emissions (DPOAE) test showed no meaningful difference between the two groups. For the frontal subcomponent, the mean amplitudes of the MMN peak for the two groups illustrated less negative meaningful MMN peak amplitudes in the group of persons with tinnitus. For the supratemporal component at 5 kHz central frequency, amplitudes were lower for the group of persons with tinnitus, whereas for the central frequency of 1 kHz, most deviants exhibited meaningful differences. Additionally, within-group comparisons indicated that mean amplitudes for both groups were more negative at the central frequency of 1 kHz for the frontal MMN subcomponent. In comparison, the supratemporal component illustrated a lower peak amplitude at 5 kHz central frequency in the group of persons with tinnitus and no difference in the NH group, which is a unique observation of this study. Results of the between-groups are in accordance with previous studies and within-group comparisons consider the probability of decreasing the change detection capability of the brain. The results of this study indicate that increasing the frequency of the stimuli close to the tinnitus perceived frequencies decreases the prediction error, including the prediction error of the silence. Such a decrease may cause the prediction error of the spontaneous neural activity in the auditory pathway to exceed the silence prediction error, and as a result, increases the probability of occurrence of tinnitus in higher frequencies according to the predictive coding model.

Studying the Effect of Carrier Type on the Perception of Vocoded Stimuli via Mismatch Negativity.

Vocoder processing has been long used in many studies to examine how acoustic cues affect speech understanding and auditory processing. Early behavioral studies have shown that the type of carrier (i.e., pure-tone or noise) used in vocoding process affected the intelligibility of the perceived speech, and tone-vocoded stimuli had a perceptual advantage over noise-vocoded stimuli. This work further assessed whether the auditory evoked cortical response could objectively measure the perceptual difference between the two types of vocoded stimuli using an oddball-paradigm based event-related potential (ERP) experiment. A vowel stimulus was processed by noise- and tone-vocoding processes, and the processed stimuli were presented to normal-hearing listeners in an ERP experiment. The noise-vocoded and tone-vocoded vowel stimuli served as the deviant stimuli and the non-vocoded vowel stimulus as the standard stimulus. Experimental results showed that tone-vocoded stimulus evoked a significantly larger mismatch negativity (MMN) amplitude and a significantly shorter MMN peak latency than noise-vocoded stimulus did. Results in this work suggested that compared to noise-vocoded stimulus, tone-vocoded stimulus had a larger perceptual difference relative to the reference stimulus, and this effect caused by the usage of different carrier signals could be reflected by the MMN response.

한국인들과 영어원어민들의 영어 고모음 인지에 관한 사건관련 뇌전위 연구

This study examined English and Korean speakers" brain responses to English high vowels. An ERP experiment was conducted using synthesized vowels to obtain brain waves and find their differences called mismatch negativity (MMN). The experiment results showed that both English and Korean speakers" brain waves had negative peaks around the same time after they heard the stimuli. However, the MMN peak of the English speakers was higher during longer periods than that of the Korean speakers. This is assumed to be a typical pattern for native speakers when they involuntarily hear phonemes of their mother tongue. There was no statistical difference between the Korean speakers" brain responses based on English proficiency levels.

One Way or Another: Evidence for Perceptual Asymmetry in Pre-attentive Learning of Non-native Contrasts.

Research investigating listeners’ neural sensitivity to speech sounds has largely focused on segmental features. We examined Australian English listeners’ perception and learning of a supra-segmental feature, pitch direction in a non-native tonal contrast, using a passive oddball paradigm and electroencephalography. The stimuli were two contours generated from naturally produced high-level and high-falling tones in Mandarin Chinese, differing only in pitch direction (Liu and Kager, 2014). While both contours had similar pitch onsets, the pitch offset of the falling contour was lower than that of the level one. The contrast was presented in two orientations (standard and deviant reversed) and tested in two blocks with the order of block presentation counterbalanced. Mismatch negativity (MMN) responses showed that listeners discriminated the non-native tonal contrast only in the second block, reflecting indications of learning through exposure during the first block. In addition, listeners showed a later MMN peak for their second block of test relative to listeners who did the same block first, suggesting linguistic (as opposed to acoustic) processing or a misapplication of perceptual strategies from the first to the second block. The results also showed a perceptual asymmetry for change in pitch direction: listeners who encountered a falling tone deviant in the first block had larger frontal MMN amplitudes than listeners who encountered a level tone deviant in the first block. The implications of our findings for second language speech and the developmental trajectory for tone perception are discussed.

Sensory Intelligence for Extraction of an Abstract Auditory Rule: A Cross-Linguistic Study

In a complex linguistic environment, while speech sounds can greatly vary, some shared features are often invariant. These invariant features constitute so-called abstract auditory rules. Our previous study has shown that with auditory sensory intelligence, the human brain can automatically extract the abstract auditory rules in the speech sound stream, presumably serving as the neural basis for speech comprehension. However, whether the sensory intelligence for extraction of abstract auditory rules in speech is inherent or experience-dependent remains unclear. To address this issue, we constructed a complex speech sound stream using auditory materials in Mandarin Chinese, in which syllables had a flat lexical tone but differed in other acoustic features to form an abstract auditory rule. This rule was occasionally and randomly violated by the syllables with the rising, dipping or falling tone. We found that both Chinese and foreign speakers detected the violations of the abstract auditory rule in the speech sound stream at a pre-attentive stage, as revealed by the whole-head recordings of mismatch negativity (MMN) in a passive paradigm. However, MMNs peaked earlier in Chinese speakers than in foreign speakers. Furthermore, Chinese speakers showed different MMN peak latencies for the three deviant types, which paralleled recognition points. These findings indicate that the sensory intelligence for extraction of abstract auditory rules in speech sounds is innate but shaped by language experience.

The interaction between phonological information and pitch type at pre-attentive stage: an ERP study of lexical tones

ABSTRACTPrevious studies on the processing of lexical tones have typically confounded effects due to phonological information (different meanings of words signalled by syllables with different tonal categories) with effects due to specific acoustic information (pitch type: pitch height/pitch contour). The present study is designed to dissociate these two kinds of effects and further investigate the processing of lexical tones at pre-attentive stage by mismatch negativity (MMN). We chose level tones and contour tones in Cantonese to differentiate pitch height from pitch contour, and manipulated tonal category (within-category/across-category) to distinguish phonological information from acoustic information. The results showed clear interactions between tonal category and pitch type in MMN mean amplitude and peak latency, suggesting the interaction between phonological information and pitch type in the pre-attentive processing of lexical tones. These results are discussed in light of cognitive and neural mechanisms underlying auditory processing of lexical tones.

Mismatch negativity as a potential neurobiological marker of early-stage Alzheimer disease and vascular dementia

Alzheimer's disease (AD) and vascular dementia (VD) are serious, irreversible forms of cognitive impairment, which means that an early diagnosis is essential to slow down their progression. One potential neurophysiological biomarker of these diseases is the mismatch negativity (MMN) event-related potentials (ERP) component, which reflects an automatic detection mechanism at the pre-attentive stages of information processing. We evaluated the auditory MMN response in individuals from two patient groups: those in the prodromal stages of AD (P-AD) and those in the prodromal stages of VD (P-VD). Thirty patients (15 P-AD patients and 15 P-VD patients) and 30 age-matched controls were recruited to undergo electrophysiological recordings during the presentation of an auditory deviant-standard-reverse oddball paradigm that was used to elicit genuine MMN responses. We show that over the frontal–central area, the mean amplitude of the MMN was significantly reduced in both the P-AD (p=0.017) and P-VD groups (p=0.013) compared with controls. The MMN peak latency in P-VD patients was significantly shorter than in controls (p=0.027). No MMN response differences between the P-AD and P-VD were found in either the frontal–central or the temporal areas. These results indicate that P-AD and P-VD patients exhibit impaired pre-attentive information processing mechanisms as revealed by the frontal–central area MMN response, which is associated with sensory memory and cognitive deficits.

Comparison of Pre-Attentive Auditory Discrimination at Gross and Fine Difference between Auditory Stimuli.

Introduction Mismatch Negativity is a negative component of the event-related potential (ERP) elicited by any discriminable changes in auditory stimulation. Objective The present study aimed to assess pre-attentive auditory discrimination skill with fine and gross difference between auditory stimuli. Method Seventeen normal hearing individual participated in the study. To assess pre-attentive auditory discrimination skill with fine difference between auditory stimuli, we recorded mismatch negativity (MMN) with pair of stimuli (pure tones), using /1000 Hz/ and /1010 Hz/ with /1000 Hz/ as frequent stimulus and /1010 Hz/ as infrequent stimulus. Similarly, we used /1000 Hz/ and /1100 Hz/ with /1000 Hz/ as frequent stimulus and /1100 Hz/ as infrequent stimulus to assess pre-attentive auditory discrimination skill with gross difference between auditory stimuli. The study included 17 subjects with informed consent. We analyzed MMN for onset latency, offset latency, peak latency, peak amplitude, and area under the curve parameters. Result Results revealed that MMN was present only in 64% of the individuals in both conditions. Further Multivariate Analysis of Variance (MANOVA) showed no significant difference in all measures of MMN (onset latency, offset latency, peak latency, peak amplitude, and area under the curve) in both conditions. Conclusion The present study showed similar pre-attentive skills for both conditions: fine (1000 Hz and 1010 Hz) and gross (1000 Hz and 1100 Hz) difference in auditory stimuli at a higher level (endogenous) of the auditory system.

The mismatch negativity as a measure of auditory stream segregation in a simulated “cocktail-party” scenario: effect of age

With age the ability to understand speech in multitalker environments usually deteriorates. The central auditory system has to perceptually segregate and group the acoustic input into sequences of distinct auditory objects. The present study used electrophysiological measures to study effects of age on auditory stream segregation in a multitalker scenario. Younger and older adults were presented with streams of short speech stimuli. When a single target stream was presented, the occurrence of a rare (deviant) syllable among a frequent (standard) syllable elicited the mismatch negativity (MMN), an electrophysiological correlate of automatic deviance detection. The presence of a second, concurrent stream consisting of the deviant syllable of the target stream reduced the MMN amplitude, especially when located nearby the target stream. The decrease in MMN amplitude indicates that the rare syllable of the target stream was less perceived as deviant, suggesting reduced stream segregation with decreasing stream distance. Moreover, the presence of a concurrent stream increased the MMN peak latency of the older group but not that of the younger group. The results provide neurophysiological evidence for the effects of concurrent speech on auditory processing in older adults, suggesting that older adults need more time for stream segregation in the presence of concurrent speech.

A systematic review of the mismatch negativity as an index for auditory sensory memory: From basic research to clinical and developmental perspectives

Auditory sensory memory is an important ability for successful language acquisition and processing. The mismatch negativity (MMN) in response to auditory stimuli has been proposed as an objective tool to measure the existence of auditory sensory memory traces. By increasing interstimulus intervals, attenuation of MMN peak amplitude and increased MMN peak latency have been suggested to reflect duration and decay of sensory memory traces. The aim of the present study is to conduct a systematic review of studies investigating sensory memory duration with MMN. Searches of electronic databases yielded 743 articles. Of these, 37 studies met final eligibility criteria. Results point to maturational changes in the time span of auditory sensory memory from birth on with a peak in young adulthood, as well as to a decrease of sensory memory duration in healthy aging. Furthermore, this review suggests that sensory memory decline is related to diverse neurological, psychiatric, and pediatric diseases, including Alzheimer's disease, alcohol abuse, schizophrenia, and language disorders. This review underlines that the MMN provides a unique window to the cognitive processes of auditory sensory memory. However, further studies combining electrophysiological and behavioral data, and further studies in clinical populations are needed, also on individual levels, to validate the MMN as a clinical tool for the assessment of sensory memory duration.

Neural correlates of individual differences in processing of rising tones in Cantonese: Implications for speech perception and production

Neural correlates of individual differences in processing of rising tones in Cantonese: Implications for speech perception and production

Wavelet Decomposition-Based Analysis of Mismatch Negativity Elicited by a Multi-Feature Paradigm

In this study, event-related potentials (ERPs) collected from normally hearing subjects and elicited by a multi-feature paradigm were investigated, and mismatch negativity (MMN) was detected. Standard stimuli and five types of deviant stimuli were presented in a specified sequence, while EEG data were recorded digitally at a 1024 sec–1 sampling rate. Two wavelet analyses were compared with a traditional difference-wave (DW) method. The Reverse biorthogonal wavelet ot the order of 6.8 and the quadratic B-Spline wavelet were applied for seven-level decomposition. The sixth-level approximation coefficients were appropriate for extracting the MMN from the averaged trace. The results obtained showed that wavelet decomposition (WLD) methods extract MMN as well as a band-pass digital filter (DF). The differences of the MMN peak latency between deviant types elicited by B-Spline WLD were more significant than those extracted by the DW, DF, or Reverse biorthogonal WLD. Also, wavelet coefficients of the delta-theta range indicated good discrimination between some combinations of the deviant types.

Impaired mismatch negativity is associated with current functional status rather than genetic vulnerability to schizophrenia

The aim of this study is to investigate whether mismatch negativity (MMN) is associated with functional status or is a state-independent trait for schizophrenia. We assessed MMN in 26 patients with schizophrenia, 20 healthy subjects with high genetic loading, and 48 healthy controls. Repeated measures analysis of variance and Pearson׳s correlations were used to test the hypothesis that MMN is not state-independent. We found a significant main effect of group, indicating differences in the peak amplitudes of the MMN among the three groups. Post-hoc analyses revealed that schizophrenia patients showed a significant reduction in the peak amplitude of MMN, but subjects at high genetic risk and healthy controls did not. Additionally, significant correlations between Global Assessment of Functioning scores and MMN peak amplitude at Fz and Cz were found in patients with schizophrenia. These findings suggest that MMN may reflect current functional status rather than a genetic risk for schizophrenia.