MMN Studies Research Articles

Effects of attention on the processing of physical and abstract auditory regularities: An exploratory MMN study

The mismatch-negativity (MMN) component of the auditory event-related potential (ERP) reflects preattentive memory mechanisms encoding various types of regularities in the auditory environment. In an oddball paradigm, two types of deviant stimuli (in separate blocks) were presented among frequent standard stimuli: physical deviants (higher in pitch than the standards) and more complex, “abstract” deviants (tone pairs descending in pitch, presented among ascending standard tone pairs). The attentional load of the participant was manipulated under three conditions, where the participants either (1) watched a silent video, (2) played a computer game (Tetris) or (3) attended to the auditory stimuli and tried to detect infrequent target stimuli which were of lower intensity than the standard stimuli. The goal was to find out, whether the possible attention effects (suppression/enhancement) on the MMN are similar or different to stimuli requiring the extraction of either physical or abstract invariances. Both the physical and abstract deviants elicited in all conditions MMNs but no statistically significant amplitude differences between the conditions were found. The N2b and P3b components were elicited only in the attend condition and only by the soft target tones. The results further confirm that the MMN is a robust response to various types of regularity violations, showing no major effects of attentional manipulations. The results also suggest that the most commonly used primary task in MMN experiments, watching a silent video, usually keeps the participants' attention well enough directed away from the auditory stimuli. However, in cases where a cognitively more demanding but still participant-friendly primary task is needed, a simple computer game such as Tetris can be used, enabling better control of the participants’ attention and vigilance.

Statistical Learning of Chord-Transition Regularities in a Novel Equitempered Scale: An MMN Study

Statistical Learning of Chord-Transition Regularities in a Novel Equitempered Scale: An MMN Study

Features of Duration Mismatch Negativity Around the Onset of Overt Psychotic Disorders: A Longitudinal Study.

Reduced amplitude of duration mismatch negativity (dMMN) has been reported in psychotic disorders and at-risk mental state (ARMS); however, few longitudinal MMN studies have examined the amplitude changes during the course of psychosis. We compared dMMN amplitude between ARMS individuals with later psychosis onset and those without, and we longitudinally examined potential dMMN changes around psychosis onset. Thirty-nine ARMS subjects and 22 healthy controls participated in this study. Of the 39 ARMS subjects, 11 transitioned to psychosis (at-risk mental state with later psychosis onset [ARMS-P]) during follow-up and 28 did not (at-risk mental state without later psychosis onset [ARMS-NP]). dMMN was measured twice using an auditory oddball paradigm with a mean interval of 2years. Follow-up dMMN data were available for all but four ARMS-P subjects. dMMN amplitude at baseline was smaller in ARMS-P subjects compared with control and ARMS-NP subjects. Additionally, ARMS-P subjects displayed a longitudinal decline in dMMN amplitude, which was not present in control and ARMS-P subjects. We also observed a progressive decline in dMMN amplitude during the transition period, suggesting dynamic brain changes associated with the psychosis onset. Our findings implicate dMMN amplitude as a biological predictor of future psychosis onset in high-risk individuals, which may be used for early detection and intervention of psychosis.

Dysfunctional frontal activation of mismatch negativity in panic disorder: A magnetoencephalographic study

BackgroundMismatch negativity (MMN) or its magnetic counterpart (MMNm) is a neurophysiological signal to reflect the automatic change-detection ability. However, MMN studies in patients with panic disorder (PD) showed contrasting results using electroencephalographic (EEG) recordings. The present study attempted to overcome the limitations of EEG methodology by means of a whole-head magnetoencephalography (MEG) combined with the depth-weighted minimum norm estimate method to conduct an in-depth investigation on the MMNm at the cortical level in patients with PD. MethodsWe recruited 22 healthy controls (HC) and 20 patients with PD to perform auditory oddball paradigm during MEG recordings. The cortical MMNm amplitudes and latencies in the superior temporal gyrus, inferior parietal lobule, and inferior frontal gyrus (IFG) were compared between the HC and PD groups. The correlations between MMNm responses and clinical measurement were also examined. ResultsCompared with the HC group, the PD group demonstrated significantly reduced MMNm amplitudes in the IFG. Furthermore, higher trait scores of the State-Trait Anxiety Inventory were associated with lower MMNm amplitudes of the right IFG among patients with PD. LimitationsGeneralization of the current results to other settings or samples should be made cautiously due to the use of different medication regimens and presence of comorbidities in our patients. ConclusionsOur data suggest dysfunctional pre-attentive change-detection ability in patients with PD, particularly in the IFG.

S137. LEFT HEMISPHERE MEG DEFICIT IN PITCH AND DURATION MISMATCH NEGATIVITY IN FIRST EPISODE PSYCHOSIS

BackgroundMismatch negativity (MMN) is an event-related potential (ERP) that is severely impaired in long-term schizophrenia. However, though largely debated, numerous electroencephalography (EEG) studies suggest that MMN is less reduced in individuals at their first episode of psychosis (FEP). Pitch MMN (pMMN) is not reduced, although duration MMN (dMMN) may be reduced compared to healthy controls (HC), and may show left hemisphere deficits early on. Few MMN studies in FEP have utilized magnetoencephalography (MEG). MEG could potentially be more sensitive to circumscribed differences, given its ability to more effectively localize MMN sources within the auditory cortex. Using MEG, we compared pMMN and dMMN between FEP and HC to identify potential source location- and timing-dependent differences in early disease course.MethodsSimultaneous MEG and EEG recordings of pMMN and dMMN were obtained with an oddball paradigm from 15 FEP and 19 HC. Of those, 12 FEP and 11 HC had usable EEG recordings, with the remainder lost due to a circuit board failure. MMN was calculated by subtraction of the sensor-space average to the standard tones from the average to the deviant tones. For EEG, mean amplitudes across fronto-central electrodes (F1, Fz, F2, FC1, FCz, FC2) were calculated over a 30 msec window at group peak latency. For MEG data, source activity was determined in Brainstorm using minimum norm estimation, multisphere head models, and individual MRI cortical surface reconstructions. Using the HCP Brain Atlas, regions of interest (ROIs) were determined based on areas of peak activity at two time windows for each task: an Early time window of 105–115 ms for both pMMN and dMMN, and a Late time window of 125–135 ms for pMMN and 155–165 ms for dMMN. Mean amplitudes were calculated over six auditory cortex ROIs: A1, Brodmann’s Area 43, Brodmann’s Area 52, Lateral Belt, Medial Belt, and Parabelt. Mixed-model ANOVA was then used to compare groups, regions, hemispheres, time windows, and tasks using SPSS software.ResultsFor EEG peak MMNs, there were no significant differences between groups in pMMN or dMMN (p’s > 0.1). For MEG sources, however, ANOVA indicated a Region x Hemisphere x Group interaction (p = 0.038), but no significant regional differences between Pitch and Duration or for either Early or Late time windows (p’s > 0.1). When ROI data were averaged across tasks and time windows, the right hemisphere showed no difference between groups, whereas the left hemisphere showed a trend for reduced MMN activity in FEP (p = 0.069). Post-hoc comparisons of the six left hemisphere ROIs revealed that all regions but Brodmann’s Area 43 showed significant reduction in FEP (p’s < 0.05).DiscussionThese findings support previous literature that indicate relatively preserved EEG scalp measures of MMN in FEP. However, the MEG source data indicate a deficit in the left hemisphere auditory cortex of FEP. This left hemisphere reduction was observed in 5 out of 6 source regions and at both time windows. This suggests broad left hemisphere auditory cortex pathophysiology early in disease course to which EEG may be relatively less sensitive by comparison with MEG. In conclusion, FEP may be associated with a selective left hemisphere MMN deficit in auditory regions on the superior temporal plane, but not the opercular cortex (i.e. Brodmann’s Area 43).

Gender Differences in Global Functional Connectivity During Facial Emotion Processing: A Visual MMN Study.

To investigate gender differences in functional connectivity during the unattended processing of facial expressions, we recorded visual mismatch negativity (vMMN) in 34 adults using a deviant-standard reverse oddball paradigm. Using wavelet analysis, we calculated the time-frequency (TF) power at each electrode associated with happy-deviant, sad-deviant, happy-standard and sad-standard conditions. We also calculated the phase lag index (PLI) between electrode pairs and analyzed the dynamic network topologies of the functional connectivity for happy and sad vMMNs in the delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), beta (13–30 Hz) and gamma (30–45 Hz) bands. The results showed that females induced stronger TF power and PLI values than males in only the alpha band over the whole brain regarding the vMMN. Moreover, females had a higher ratio of the number of connections between long-distance electrode pairs than males. While theoretical analysis of dynamic network topologies indicated that high node degree values were found in local brain regions of males and in almost the entire female brain, our findings suggested that female brain activation and connections between brain regions are not only stronger but also more widely distributed during the unattended processing of facial expressions than those in males.

Processing of word stress related acoustic information: A multi-feature MMN study

In the present study, we investigated the processing of word stress related acoustic features in a word context. In a passive oddball multi-feature MMN experiment, we presented a disyllabic pseudo-word with two acoustically similar syllables as standard stimulus, and five contrasting deviants that differed from the standard in that they were either stressed on the first syllable or contained a vowel change. Stress was realized by an increase of f0, intensity, vowel duration or consonant duration. The vowel change was used to investigate if phonemic and prosodic changes elicit different MMN components. As a control condition, we presented non-speech counterparts of the speech stimuli.Results showed all but one feature (non-speech intensity deviant) eliciting the MMN component, which was larger for speech compared to non-speech stimuli. Two other components showed stimulus related effects: the N350 and the LDN (Late Discriminative Negativity). The N350 appeared to the vowel duration and consonant duration deviants, specifically to features related to the temporal characteristics of stimuli, while the LDN was present for all features, and it was larger for speech than for non-speech stimuli. We also found that the f0 and consonant duration features elicited a larger MMN than other features.These results suggest that stress as a phonological feature is processed based on long-term representations, and listeners show a specific sensitivity to segmental and suprasegmental cues signaling the prosodic boundaries of words. These findings support a two-stage model in the perception of stress and phoneme related acoustical information.

Variability in L2 phonemic learning originates from speech-specific capabilities: An MMN study on late bilinguals

People differ in their ability to perceive second language (L2) sounds. In early bilinguals the variability in learning L2 phonemes stems from speech-specific capabilities (Díaz, Baus, Escera, Costa &amp; Sebastián-Gallés, 2008). The present study addresses whether speech-specific capabilities similarly explain variability in late bilinguals. Event-related potentials were recorded (using a design similar to Díaz et al., 2008) in two groups of late Dutch–English bilinguals who were good or poor in overtly discriminating the L2 English vowels /ε-æ/. The mismatch negativity, an index of discrimination sensitivity, was similar between the groups in conditions involving pure tones (of different length, frequency, and presentation order) but was attenuated in poor L2 perceivers for native, unknown, and L2 phonemes. These results suggest that variability in L2 phonemic learning originates from speech-specific capabilities and imply a continuity of L2 phonemic learning mechanisms throughout the lifespan.

Hypersensitivity to change in children with autism spectrum disorder: Convergent evidence from visual and auditory MMN studies

Several electrophysiological studies found response differences to a given stimulus when it is repeated frequently as compared to when it occurs rarely in oddball sequences. Initially defined in acoustic perception, such difference also exists in the visual modality and is referred to as visual mismatch negativity (vMMN). However, the repetition of a stimulus also leads to the reduction of the blood oxygen-level dependent (BOLD) signal (fMRI adaptation, fMRIa) when compared to alternating stimuli in fMRI experiments. So far no study compared the vMMN to fMRIa within the same paradigm and participants. Here we tested the possible connection between fMRIa and vMMN in a visual oddball paradigm in two separate sessions, acquiring electrophysiological and neuroimaging data for real and false characters from the same participants. We found significant visual mismatch response (vMM) as well as fMRIa for both character types. Importantly, the magnitude of the vMM over the CP1 electrode cluster showed a significant correlation with the fMRIa within the letter form area, for real characters. This finding suggests that similar neural mechanisms are responsible for the two phenomena.

Automatic detection of orientation changes of faces versus non-face objects: A visual MMN study

To investigate the automatic change detection of faces versus non-face objects, the visual mismatch negativity (vMMN) elicited by deviant orientation (90° versus 0°) for faces and houses, respectively, was recorded using the deviant-standard-reversed paradigm. The present face stimuli elicited larger N170 than did houses, regardless of the orientation. A larger and delayed N170 for deviant rotated faces was elicited than that for standard rotated faces, whereas the N170 did not differ between deviant and standard rotated houses. The rotated faces elicited increased vMMN amplitude and decreased vMMN latency than did the rotated houses. The face-MMN with a right occipito-temporal scalp distribution was larger for the rotated than upright conditions but the orientation did not modulate the amplitudes of house MMN. These data provided electrophysiological evidence for larger sensitivity for orientation changes of faces than those of objects even in the absence of attention, due to the disruption of configural processing caused by face rotation.

Involuntary attention in essential tremor: A MMN study

Involuntary attention in essential tremor: A MMN study

Human Visual System Automatically Encodes Sequential Regularities of Discrete Events

For our adaptive behavior in a dynamically changing environment, an essential task of the brain is to automatically encode sequential regularities inherent in the environment into a memory representation. Recent studies in neuroscience have suggested that sequential regularities embedded in discrete sensory events are automatically encoded into a memory representation at the level of the sensory system. This notion is largely supported by evidence from investigations using auditory mismatch negativity (auditory MMN), an event-related brain potential (ERP) correlate of an automatic memory-mismatch process in the auditory sensory system. However, it is still largely unclear whether or not this notion can be generalized to other sensory modalities. The purpose of the present study was to investigate the contribution of the visual sensory system to the automatic encoding of sequential regularities using visual mismatch negativity (visual MMN), an ERP correlate of an automatic memory-mismatch process in the visual sensory system. To this end, we conducted a sequential analysis of visual MMN in an oddball sequence consisting of infrequent deviant and frequent standard stimuli, and tested whether the underlying memory representation of visual MMN generation contains only a sensory memory trace of standard stimuli (trace-mismatch hypothesis) or whether it also contains sequential regularities extracted from the repetitive standard sequence (regularity-violation hypothesis). The results showed that visual MMN was elicited by first deviant (deviant stimuli following at least one standard stimulus), second deviant (deviant stimuli immediately following first deviant), and first standard (standard stimuli immediately following first deviant), but not by second standard (standard stimuli immediately following first standard). These results are consistent with the regularity-violation hypothesis, suggesting that the visual sensory system automatically encodes sequential regularities. In combination with a wide range of auditory MMN studies, the present study highlights the critical role of sensory systems in automatically encoding sequential regularities when modeling the world.

Arabic Morphology in the Neural Language System

There are two views about morphology, the aspect of language concerned with the internal structure of words. One view holds that morphology is a domain of knowledge with a specific type of neurocognitive representation supported by specific brain mechanisms lateralized to left fronto-temporal cortex. The alternate view characterizes morphological effects as being a by-product of the correlation between form and meaning and where no brain area is predicted to subserve morphological processing per se. Here we provided evidence from Arabic that morphemes do have specific memory traces, which differ as a function of their functional properties. In an MMN study, we showed that the abstract consonantal root, which conveys semantic meaning (similarly to monomorphemic content words in English), elicits an MMN starting from 160 msec after the deviation point, whereas the abstract vocalic word pattern, which plays a range of grammatical roles, elicits an MMN response starting from 250 msec after the deviation point. Topographically, the root MMN has a symmetric fronto-central distribution, whereas the word pattern MMN lateralizes significantly to the left, indicating stronger involvement of left peri-sylvian areas. In languages with rich morphologies, morphemic processing seems to be supported by distinct neural networks, thereby providing evidence for a specific neuronal basis for morphology as part of the cerebral language machinery.

Predicting coma and other low responsive patients outcome using event-related brain potentials: A meta-analysis

Objective A meta-analysis was performed to estimate the predictive power (odd ratio, OR) for awakening of auditory event-related potential (ERP) components in low responsive patients with stroke or hemorrhage, trauma, anoxic, post-operative, and metabolic encephalopathy etiologies. Methods We reviewed MEDLINE and analyzed citations for retrieved articles. Logistic regressions were applied on patient samples (Glasgow Coma Scale <12) across and for separate etiologies. Results For stroke and hemorrhage the ORs with 95% confidence intervals were: 2.05 [1.12–3.75] (N100), 4.47 [1.92–10.44] (MMN), 10.29 [2.00–52.79] (P300), for trauma: 1.63 [0.70–3.80] (N100), 4.72 [1.35–16.44] (MMN), 12.89 [4.82–34.43] (P300), anoxic: 8.03 [2.83–22.75] (N100), 15.50 [4.27–56.26] (MMN), 5.93 [2.38–14.77] (P300), post-operative: 10.66 [1.98–57.50] (N100), metabolic encephalopathy: 2.12 [0.34–13.13] (N100), 3.60 [0.28–46.36] (MMN), 7.71 [0.75–79.77] (P300), and all etiologies: 2.85 [1.91–4.27] (N100), 6.53 [3.55–12.01] (MMN), and 8.79 [4.88–15.83] (P300). Based on six N100 studies ( N = 548 patients), five MMN studies ( N = 470), and six P300 studies ( N = 313), the N100, MMN, or P300, when present, significantly predicted awakening, P300 and MMN being significantly better predictors than N100. Conclusions The MMN and P300 appear to be reliable predictors of awakening. Significance The prognostic assessment of low responsive patients with auditory ERP should take into account both MMN and P300.

ERP Repetition Effects and Mismatch Negativity Generation

Neuronal adaptation is a ubiquitous property of the cortex. This review presents evidence from MMN studies that show ERP components with similar adaptive properties. Specifically, I consider the empirical evidence from the perspective of a predictive coding model of perceptual learning and inference. Within this framework, ERP and neuronal repetition effects (repetition suppression) are seen as reductions in prediction error, a process that requires synaptic modifications. Repetition positivity is a human auditory ERP component, which shows similar properties to stimulus-specific adaptation of auditory cortex neurons; a candidate mechanism for auditory trace formation.