Mismatch Negativity Peak Latency Research Articles

Neural mechanisms of auditory sensory processing in children with high intelligence

To investigate the differences in event-related potential parameters related to children's intelligence, 18 intellectually gifted children and 18 average children participated in this study. The electroencephalograms were recorded the auditory sensory memory that elicited the mismatch negativity (MMN) and late discriminative negativity (LDN), as well as involuntary attention switch that elicited the P3a and early MMN were analyzed. The results indicated that children with high intelligence had comparatively larger MMN, LDN, early MMN, P3a amplitudes, and earlier peak latency in LDN than average children. The enhanced neural function of the intellectually gifted children might be due to more spatially and temporally coordinated neural network, faster neural processing speed and more efficient neural activation functions.

Does Mismatch Negativity Show Differences in Reading-Disabled Children Compared to Normal Children and Children with Attention Deficit?

An auditory event-related potential (ERP) component called mismatch negativity (MMN) was examined in three groups of children (n = 63) aged 8–14 years. A control group comprised healthy children in second or sixth grade of comprehensive school (n = 21). The two clinical groups included children with reading disability (RD) (n = 21) and children with attention deficit (AD) (n = 21). MMN was elicited in a passive oddball paradigm by duration changes in a continuous sound, consisting of two alternating (600 and 800 Hz) 100 msec tones. The deviant tones were either 30 or 50 msec in duration. Both deviants elicited a clear MMN in all groups. Statistical analyses showed no systematic difference in the MMN peak latencies or amplitudes between the groups. A significant difference between the RD group and the control group was observed in the lateralization of the MMN peak amplitudes.

An electrophysiological measure of temporal resolution in normal subjects using frequency modulated signals.

This investigation was conducted to determine whether an exogenous event-related potential called the mismatch negativity (MMN) would change systematically in response to frequency-modulated signals with varying temporal properties. Both N1 and P2 waveforms were recorded for 50-ms frequency-modulated signals from normal hearing listeners. The standard stimuli for this investigation were continuous sweep tones with center frequencies of 1000 Hz that traversed a frequency range of 200 Hz in a single step. The rare stimuli were signals that traversed the same frequency range in two, four, six, or eight discrete steps. Results suggest that for the 10 participants, 1) the mean MMN peak-to-peak amplitude and mean area decreased significantly with decreases in step duration, 2) MMN area amplitude was the best indicator of psychophysical performance for the two magnitude measures, and 3) MMN onsets and peak latencies did not show either a significant increase or decrease in latency as step duration decreased.

Temporal resolution in young and elderly subjects as measured by mismatch negativity and a psychoacoustic gap detection task

Objectives: The speech understanding difficulties of elderly persons with age-related hearing loss may be related in part to reduced auditory temporal resolution. To investigate the effects of aging on temporal resolution, the electrophysiological and psychoacoustic detection thresholds for a very short silent gap within a pure tone were determined, and the relation between the two test results was examined. Methods: Behavioral gap detection thresholds were determined in 10 young and 10 elderly normally hearing subjects using an adaptive test procedure. To elicit mismatch negativity (MMN), deviant stimuli with gap durations varying from 6 to 24 ms in 3 ms steps were presented in separate test blocks. Results: There were no significant differences in the psychoacoustic gap detection thresholds between young and elderly subjects. In contrast, longer gaps were needed to elicit MMN in elderly subjects. They also had significantly reduced MMN peak amplitudes, increased MMN peak latencies, a significantly smaller P2 amplitude and longer P2 latency in their responses to the standard stimulus when compared to the same measures in young subjects. Conclusions: Processing of basic temporal stimulus features in elderly subjects is considerably more reduced at the preattentive level (as indicated by MMN), than when attention is directed to the task (as indicated by the psychoacoustic results).

The intensity of masking noise affects the mismatch negativity to speech sounds in human subjects

The present study investigated the effects of decreased audibility of the speech sounds ‘ba’ and ‘da’ on the mismatch negativity (MMN). Audibility was altered by varying the intensity of the masking noise to be either 0 (no noise), 65, 70 or 75 dB speech perception level. Cortical event-related potentials were recorded while normal listeners ( n=7) were instructed to ignore the stimuli. In a separate condition, subjects were asked to signal detection of the deviant stimulus by button-press. As audibility of speech sounds was decreased, MMN peak amplitude decreased and MMN peak latency increased. Behavioral responses were in accordance with the MMN data. Hit rates decreased as audibility decreased. These results suggest that both pre-attentive and attentive speech discrimination deteriorate following a reduction in audibility.

Adenosine A1/A2a receptors mediate suppression of mismatch negativity by ethanol in humans

Acute alcohol challenge suppresses the mismatch negativity (MMN) component of the auditory event-related potential (ERP), however, the transmitter systems underlying MMN generation/mediating this effect have remained vague. To test adenosinergic contribution, 12 healthy social drinkers participated in four sessions, ingesting: (1) placebo pill and placebo beverage; (2) caffeine (100 mg) and placebo beverage; (3) placebo pill and alcohol (0.55 g/kg in 10% (v/v) solution); or (4) both caffeine and alcohol. ERP measured during a dichotic-listening task disclosed increased MMN and P3b peak latencies, and diminished amplitude of processing negativity (PN) with alcohol, however, only the increase in MMN peak latency was significantly antagonized by caffeine. The results suggest that A1 and A2a receptors play a role in the generation of, and mediate partly the suppressant effect of ethanol on, the MMN.

Effects of naltrexone and ethanol on auditory event-related brain potentials

Acute effects of ethanol (0.55 g/kg) and the opioid antagonist naltrexone (50 mg) on auditory event-related brain potentials (ERP) (i.e., electrical brain activity time-locked to sensory stimuli) were investigated in 13 healthy social drinkers, using a double-blind, placebo-controlled, design. The subjects' task was to attend to tones presented to a designated ear while ignoring tones to the other, and to detect deviant tones among the attended tones. When administered alone, naltrexone significantly reduced the amplitude of the later part of negative difference (Nd 1), suggesting impaired selective attention. However, this effect might have been caused by naltrex-one-induced nausea. Ethanol, when ingested alone, attenuated the amplitude of the N1, and increased the peak latencies of the mismatch negativity (MMN) and N2b that have been suggested to reflect automatic change detection in audition and allocation of attentional resources to processing of stimulus deviance, respectively. In contrast, the P1 amplitude was augmented by alcohol, but only when the tones were attended. When ethanol and naltrexone were simultaneously ingested, however, the alcohol-induced P1 amplitude augmentation was canceled, thus tentatively suggesting opioidergic mediation of this alcohol effect. In contrast, the MMN peak latency was increased significantly more in the interaction condition than in the ethanol condition, thus suggesting that the detrimental effects of alcohol on involuntary attention switching were augmented by naltrexone. Furthermore, the N2b amplitude was significantly suppressed in the interaction condition, suggesting attentional impairment.

Mismatch negativity area and age-related auditory memory

The deviant tones embedded in a sequence of standard tones elicit an event-related potential (ERP) component called mismatch negativity (MMN). Because MMN is partly overlapped by other ERP components at 100–200 msec latency (N1 and P2) and its shape varies, MMN peak latency and amplitude may be ambiguous. We used the difference area between the deviant and standard ERP to evaluate the age and interstimulus interval (ISI) dependence of MMN. Sequences of standard (85%) and deviant (15%) tones were presented to 27 normal subjects (age 18–85 years) using 1 sec and 3 sec ISIs and to 6 young subjects using an additional ISI of 5 sec. With this method MMN was clearly seen in 26 out of 27 healthy subjects (96.3%). MMN area was quite stable regardless of age with 1 sec ISI. With 3 sec ISI MMN area was significantly smaller in the old than in the young subjects. This may reflect the shortening of the sensory auditory memory trace with increasing age.