Mismatch Negativity to Different Time-frequency Distribution Complex Tones

Mismatch negativity (MMN) is a component of auditory event-related potentials that reflects automatic change detection in the brain, showing qualities of endophenotypes in schizophrenia. MMN deficiency is one of the robust findings in patients, and it reflects both cognitive and functional decline. Catechol-o-methyltransferase (COMT) is a key enzyme involved in regulating dopamine transmission within the prefrontal cortex. A preliminary study suggested that the COMTVal108/158Met genotype (rs4680) is related to cognitive function in schizophrenia. Both the COMTVal108/158Met genotype and MMN are related to cognitive function, but no studies have reported on the relationship between MMN and the COMTVal108/158Met genotype in schizophrenia. This study therefore examined the relationship between COMTVal108/158Met genotype and MMN. The duration of MMN was measured, and the COMTVal108/158Met polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism in 49 Japanese schizophrenia patients (Val/Val, n = 21; Met carriers, n = 28). Amplitude and latency of MMN were compared between Val/Val and Met carriers.

<p class="abstract"><strong>Background:</strong> Cochlear implant provides a great opportunity for children with severe to profound sensorineural hearing loss to restore normal hearing. Identifying mismatch negativity (MMN) in cochlear implant recipients helps to assess the role of central auditory structures in processing speech stimuli in those patients. The objective of the present study is to evaluate tone and speech discrimination in cochlear implanted children using mismatch negativity test.</p><p class="abstract"><strong>Methods:</strong> MMN was recorded in 35 children. They were divided into two groups. Control group consisted of 15 normal hearing children, their age ranged from 3-11 years. Study group consisted of 20 children fitted with unilateral CI, and their age matched the control group. Two oddball paradigms were used; the first was tone bursts (1000 Hz as standard stimulus and 1050 Hz as deviant stimulus). The second was synthesized speech stimuli (/da/ as standard stimulus and /ga/ as deviant one). Both paradigms were presented at 75dB SPL.</p><p class="abstract"><strong>Results:</strong> All cochlear implanted children included showed MMN on using both oddball paradigms. Comparing results of both groups revealed statistically significant differences in MMN latency and amplitude. There was a significant positive correlation between MMN latencies and the implantation age as well as the duration of hearing loss before implantation.</p><p><strong>Conclusions:</strong> MMN provides an objective tool to assess the auditory discrimination abilities in cochlear implanted children which may help in their rehabilitation and also in the optimum setting of their devices.</p>

Hierarchical MMN subcomponents in schizophrenia: Predictive coding biomarkers and clinical translation.

ObjectiveThe mismatch negativity (MMN) event-related potential is an index of the pre-attentive stage of neural auditory information processing and an electrophysiological signal indicative of the integrity of auditory information processing with regard to the attention deficit symptom of attention deficit hyperactivity disorder (ADHD). We investigated the association between the MMN amplitude and latency in frontal brain regions and symptom severity in children with ADHD and subclinical ADHD symptoms.MethodsThis study included 29 children: 16 (10 boys; mean age, 13.06 ± 3.67 years) with ADHD (ADHD group) and 13 (eight boys; mean age, 13.40 ± 3.31 years) with sub-clinical ADHD symptoms (subclinical ADHD group). We performed the following assessments: Korean ADHD rating scale-IV (K-ARS-IV), children depression inventory, state/trait anxiety inventory for children, and MMN (measured at Fz, FCz, Cz, and CPz).ResultsThere were no sex or mean age differences between the groups (c2 = −0.01, p = 0.958; Z = −1.88, p = 0.060, respectively). The ADHD group had a significantly higher mean K-ARS-IV score (26.13 ± 9.56 vs. 17.15 ± 11.73, Z = −2.11, p = 0.035). Significant differences were found according to symptom severity in the MMN amplitude at FCz (Z = −2.11, p = 0.035) and MMN latency at Fz and FCz (Z = −2.48, p = 0.013; Z = −2.57, p = 0.010). The K-ARS-IV, K-ARS inattention subscale, and K-ARS hyperactivity-impulsivity subscale scores in the ADHD group correlated significantly with the MMN amplitude at Cz and CPz.ConclusionThis study found differences in the MMN amplitude and latency according to the severity of ADHD symptoms and identified MMN as a potential adjunct to the diagnosis of ADHD.

Down syndrome (DS) is associated with an ultra-high risk of developing Alzheimer's disease (AD). Understanding variability in pre-AD cognitive abilities may help understand cognitive decline in this population. The mismatch negativity (MMN) is an event-related potential component reflecting the detection of deviant stimuli that is thought to represent underlying memory processes, with reduced MMN amplitudes being associated with cognitive decline. To further understand the MMN in adults with DS without AD, we explored the relationships between MMN, age, and cognitive abilities (memory, language, and attention) in 27 individuals (aged 17-51) using a passive auditory oddball task. Statistically significant MMN was present only in 18 individuals up to 41years of age and the latency were longer than canonical parameters reported in the literature. Reduced MMN amplitude was associated with lower memory scores, while longer MMN latencies were associated with poorer memory, verbal abilities, and attention. Therefore, the MMN may represent a valuable index of cognitive abilities in DS. In combination with previous findings, we hypothesize that while MMN response and amplitude may be associated with AD-related memory loss, MMN latency may be associated with speech signal processing. Future studies may explore the potential impact of AD on MMN in people with DS.

Introduction Mismatch Negativity (MMN) corresponds to a response of the central auditory nervous system.Objective The objective of this study is to analyze MMN latencies and amplitudes in normal-hearing adults and compare the results between ears, gender and hand dominance.Methods This is a cross-sectional study. Forty subjects participated, 20 women and 20 men, aged 18 to 29 years and having normal auditory thresholds. A frequency of 1000Hz (standard stimuli) and 2000Hz (deviant stimuli) was used to evoked the MMN.Results Mean latencies in the right ear were 169.4ms and 175.3ms in the left ear, with mean amplitudes of 4.6µV in the right ear and 4.2µV in the left ear. There was no statistically significant difference between ears. The comparison of latencies between genders showed a statistically significant difference for the right ear, being higher in the men than in women. There was no significant statistical difference between ears for both right-handed and left-handed group. However, the results indicated that the latency of the right ear was significantly higher for the left handers than the right handers. We also found a significant result for the latency of the left ear, which was higher for the right handers.Conclusion It was possible to obtain references of values for the MMN. There are no differences in the MMN latencies and amplitudes between the ears. Regarding gender, the male group presented higher latencies in relation to the female group in the right ear. Some results indicate that there is a significant statistical difference of the MMN between right- and left-handed individuals.

Dyslexia affects 5–10% of school-aged children and is therefore one of the most common learning disorders. Research on auditory event related potentials (AERP), particularly the mismatch negativity (MMN) component, has revealed anomalies in individuals with dyslexia to speech stimuli. Furthermore, candidate genes for this disorder were found through molecular genetic studies. A current challenge for dyslexia research is to understand the interaction between molecular genetics and brain function, and to promote the identification of relevant endophenotypes for dyslexia. The present study examines MMN, a neurophysiological correlate of speech perception, and its potential as an endophenotype for dyslexia in three groups of children. The first group of children was clinically diagnosed with dyslexia, whereas the second group of children was comprised of their siblings who had average reading and spelling skills and were therefore “unaffected” despite having a genetic risk for dyslexia. The third group consisted of control children who were not related to the other groups and were also unaffected. In total, 225 children were included in the study. All children showed clear MMN activity to/da/−/ba/contrasts that could be separated into three distinct MMN components. Whilst the first two MMN components did not differentiate the groups, the late MMN component (300–700 ms) revealed significant group differences. The mean area of the late MMN was attenuated in both the dyslexic children and their unaffected siblings in comparison to the control children. This finding is indicative of analogous alterations of neurophysiological processes in children with dyslexia and those with a genetic risk for dyslexia, without a manifestation of the disorder. The present results therefore further suggest that the late MMN might be a potential endophenotype for dyslexia.

Mismatch negativity in tobacco-naïve cannabis users and its alteration with acute nicotine administration

Alcohol has been shown to impair involuntary attention studied by event-related potentials using mismatch negativity (MMN) and P3a. However, no studies have investigated whether alcohol affects the magnetic counterparts of N1 (N1m), MMN (MMNm) and P3a (P3am). Auditory evoked potentials and magnetic fields elicited by infrequent deviant tones differing in frequency (5% and 20% change) and novel sounds were recorded with whole-head magnetoencephalography (MEG) and electroencephalography (EEG). Stimuli were presented separately to the left and right ear. Eleven right-handed subjects were studied in a double-blind, placebo-controlled (0.8 g/kg ethanol or juice), cross-over design. N1m, MMNm, and P3am were calculated from the channel pair at the temporal cortex showing the strongest responses in the hemisphere contralateral to the stimulation. N1, MMN and P3a were analyzed from 12 electrodes at the midline frontocentral area. Alcohol reduced bilaterally N1, N1m, MMN and MMNm amplitudes. P3a amplitudes, but not P3am amplitudes were also significantly decreased. No effects of alcohol on the latencies of N1, MMN and P3a or their magnetic counterparts were observed. Alcohol impairs the processing of tones, frequency change and novel sounds at different phases of auditory processing similarly in both hemispheres. MEG provides us with additional information unobtainable with EEG about the effects of alcohol on the neural correlates of cognition.

BackgroundThe mismatch negativity (MMN) is an electrophysiological index of early auditory attention and has repeatedly been suggested to be associated with cognitive functioning. Despite the frequently reported finding of reduced MMN amplitude in schizophrenia, up to now, studies assessing the impact of perceptual discrimination training aiming to improve MMN measures in schizophrenia patients are scarce. MethodIn the present study, the effect of auditory training (AUD, n=14) on the MMN was compared to that of visual-spatial training (VIS, n=14) and a treatment-as-usual (TAU, n=14) condition in schizophrenia patients. Training consisted of ten 50-min sessions over two weeks. Assessments took place before and after training and at a two-month follow-up. They comprised clinical measures and MMN recordings to frequency and duration deviant stimuli. ResultsThere was a significant main effect for type of stimulus deviance with a more negative MMN to frequency than duration deviants. In contrast to our hypotheses, we did not find training specific effects on MMN amplitude or latency. ConclusionThe visual, as well as the auditory training program failed to result in treatment related MMN changes in schizophrenia patients when compared to treatment-as-usual as a control condition. In contrast to reports in healthy subjects, the induction of training related MMN changes in schizophrenia patients may constitute a specific challenge and require more extensive training protocols.

The effect of deviance predictability on mismatch negativity in schizophrenia patients

Mismatch negativity to slight pitch changes outside strong attentional focus

Effects of auditory hallucinations on the mismatch negativity (MMN) in schizophrenia as measured by a modified ‘optimal’ multi-feature paradigm

This study examined how discriminability and prototypicality of nonnative phones modulate the amplitude of the Mismatch Negativity (MMN) event-related brain potential. We hypothesized that if a frequently occurring (standard) stimulus is not prototypical to a listener, a weaker predictive memory trace will be formed and a smaller MMN will be generated for a phonetic deviant, regardless of the discriminability between the standard and deviant stimuli. The MMN amplitudes of Japanese speakers hearing the English vowels /æ/ and /ɑ/ as standard stimuli and /ʌ/ as a deviant stimulus in an oddball paradigm were measured. Although the English /æ/-/ʌ/ contrast was more discriminable than the English /ɑ/-/ʌ/ contrast for Japanese speakers, when Japanese speakers heard the /æ/ standard stimulus (i.e., less prototypical as Japanese /a/) and the /ʌ/ deviant stimulus, their MMN amplitude was smaller than the one elicited when they heard /ɑ/ as a standard stimulus (i.e., more prototypical as Japanese /a/) and /ʌ/ as a deviant stimulus. The prototypicality of the standard stimuli in listeners’ phonological representations modulates the MMN amplitude more robustly than does the discriminability between standard and deviant stimuli.

An auditory oddball paradigm in humans generates a long-duration cortical negative potential, often referred to as mismatch negativity. Similar negativity has been documented in monkeys and cats, but it is controversial whether mismatch negativity also exists in awake rodents. To this end, we recorded cortical and hippocampal evoked responses in rats during alert immobility under a typical passive oddball paradigm that yields mismatch negativity in humans. The standard stimulus was a 9 kHz tone and the deviant either 7 or 11 kHz tone in the first condition. We found no evidence of a sustained potential shift when comparing evoked responses to standard and deviant stimuli. Instead, we found repetition-induced attenuation of the P60 component of the combined evoked response in the cortex, but not in the hippocampus. The attenuation extended over three days of recording and disappeared after 20 intervening days of rest. Reversal of the standard and deviant tones resulted is a robust enhancement of the N40 component not only in the cortex but also in the hippocampus. Responses to standard and deviant stimuli were affected similarly. Finally, we tested the effect of scopolamine in this paradigm. Scopolamine attenuated cortical N40 and P60 as well as hippocampal P60 components, but had no specific effect on the deviant response. We conclude that in an oddball paradigm the rat demonstrates repetition-induced attenuation of mid-latency responses, which resembles attenuation of the N1-component of human auditory evoked potential, but no mismatch negativity.