Left hemispheric dipole locations of the neuromagnetic mismatch negativity to frequency, intensity and duration deviants
Department of Psychiatry, Friedrich-Schiller-University, Philosophenweg 3, D-07743, Jena, Germany.Cognitive Brain Research (Impact Factor: 3.77). 04/2003; 16(1):83-90. DOI: 10.1016/S0926-6410(02)00222-7
The aim of the current study was to differentiate the sources of neuromagnetic mismatch negativity (MMNm) to deviants of different features. For this purpose, the MMNm of twenty-one healthy subjects (seven males) were recorded left-hemispherically. Subjects were stimulated monaurally in an oddball paradigm with standard tones of 1000 Hz and three different kinds of mismatch tones (frequency, duration and intensity deviants). Data analysis revealed mean MMNm dipole locations anterior, inferior and more medial than the N100m dipoles. The mean difference between the N100m and MMNm dipoles was in the range of up to 6 mm in one dimension. The dipole locations of all three kinds of deviants differed significantly from each other. The MMNm dipoles of both frequency and duration deviants were found to be significantly inferior to the corresponding source of intensity deviants, while the MMNm dipoles of duration and frequency deviants significantly differed in anterior-posterior direction. This differentiation between sources emphasizes the importance of feature analysis in MMN(m) generation.
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- "As the larger responses to deviants in the oddball condition could be 'mimicked' by the responses to the same, infrequent, tones under the control condition, the differential responses to standards and deviants in the oddball condition could be fully explained by SSA (i.e., the attenuated responses to the frequently occurring standards). In addition to oddball paradigms involving a change in tone frequency, Farley and colleagues tested oddball paradigms involving a change in sound intensity and duration, as examined in previous MMN studies in humans (e.g., Sams et al. 1991; Rosburg 2003). Responses elicited in the intensity and duration oddball paradigms were again fully consistent with SSA and showed no evidence for the operation of ''genuine'' deviance detection mechanisms in A1. "
ABSTRACT: Abstract The mismatch negativity (MMN) is a pre-attentive auditory event-related potential (ERP) component that is elicited by a change in a repetitive acoustic pattern. It is obtained by subtracting responses evoked by frequent 'standard' sounds from responses evoked by infrequent 'deviant' sounds that differ from the standards along some acoustic dimension, e.g., frequency, intensity, or duration, or abstract feature. The MMN has been attributed to neural generators within the temporal and frontal lobes. The mechanisms and meaning of the MMN continue to be debated. Two dominant explanations for the MMN have been proposed. According to the "neural adaptation" hypothesis, repeated presentation of the standards results in adapted (i.e., attenuated) responses of feature-selective neurons in auditory cortex. Rare deviant sounds activate neurons that are less adapted than those stimulated by the frequent standard sounds, and thus elicit a larger 'obligatory' response, which yields the MMN following the subtraction procedure. In contrast, according to the "sensory memory" hypothesis, the MMN is a 'novel' (non-obligatory) ERP component that reflects a deviation between properties of an incoming sound and those of a neural 'memory trace' established by the preceding standard sounds. Here, we provide a selective review of studies which are relevant to the controversy between proponents of these two interpretations of the MMN. We also present preliminary neurophysiological data from monkey auditory cortex with potential implications for the debate. We conclude that the mechanisms and meaning of the MMN are still unresolved and offer remarks on how to make progress on these important issues.Brain Topography 07/2014; 27(4):500-526. · 3.47 Impact Factor
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- "In contrast, duration representations are more widely distributed and computationally complex as has been suggested by He , . Furthermore, studies evaluating MMNm sources , dipole modeling , PET  and fMRI  provided converging evidence of differential sensitivity of cortical fields in superior temporal regions with respect to different types of auditory change in healthy controls. "
ABSTRACT: The Mismatch Negativity (MMN) is an event-related potential (ERP) sensitive to early auditory deviance detection and has been shown to be reduced in schizophrenia patients. Moreover, MMN amplitude reduction to duration deviant tones was found to be related to functional outcomes particularly, to neuropsychological (working memory and verbal domains) and psychosocial measures. While MMN amplitude is thought to be correlated with deficits of early sensory processing, the functional significance of MMN latency remains unclear so far. The present study focused on the investigation of MMN in relation to neuropsychological function in schizophrenia. Forty schizophrenia patients and 16 healthy controls underwent a passive oddball paradigm (2400 binaural tones; 88% standards [1 kHz, 80 db, 80 ms], 11% frequency deviants [1.2 kHz], 11% duration deviants [40 ms]) and a neuropsychological test-battery. Patients were assessed with regard to clinical symptoms. Compared to healthy controls schizophrenia patients showed diminished MMN amplitude and shorter MMN latency to both deviants as well as an impaired neuropsychological test performance. Severity of positive symptoms was related to decreased MMN amplitude to duration deviants. Furthermore, enhanced verbal memory performance was associated with prolonged MMN latency to frequency deviants in patients. The present study corroborates previous results of a diminished MMN amplitude and its association with positive symptoms in schizophrenia patients. Both, the findings of a shorter latency to duration and frequency deviants and the relationship of the latter with verbal memory in patients, emphasize the relevance of the temporal aspect of early auditory discrimination processing in schizophrenia.PLoS ONE 04/2014; 9(4):e84536. DOI:10.1371/journal.pone.0084536 · 3.23 Impact Factor
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- "In contrast, vMMN studies based on feature (orientation and/or color)-related regularities localized deviant-specific activity to earlier anatomical structures of the cortical visual system (occipital lobe—BA 19—Kimura et al., 2010; middle occipital gyrus—Urakawa et al., 2010a,b; occipital fusiform regions—BA 17, 18, 19/7—Yucel et al., 2007). The activation of different feature-/stimulus-specific cortical structures by different types of deviants parallels results from irregularity detection in the auditory modality (e.g., Alain et al., 1999; Rosburg, 2003; Grimm et al., 2006). Interestingly, in all of the vMMN studies cited above deviant-specific activity based on higher-order irregularities or on feature irregularities was additionally found in prefrontal cortical regions (mainly the inferior frontal/medial frontal cortex). "
ABSTRACT: One of the most challenging tasks of our visual systems is to structure and integrate the enormous amount of incoming information into distinct coherent objects. It is an ongoing debate whether or not the formation of visual objects requires attention. Implicit behavioral measures suggest that object formation can occur for task-irrelevant and unattended visual stimuli. The present study investigated pre-attentive visual object formation by combining implicit behavioral measures and an electrophysiological indicator of pre-attentive visual irregularity detection, the visual mismatch negativity (vMMN) of the event-related potential. Our displays consisted of two symmetrically arranged, task-irrelevant ellipses, the objects. In addition, there were two discs of either high or low luminance presented on the objects, which served as targets. Participants had to indicate whether the targets were of the same or different luminance. In separate conditions, the targets either usually were enclosed in the same object or in two different objects (standards). Occasionally, the regular target-to-object assignment was changed (deviants). That is, standards and deviants were exclusively defined on the basis of the task-irrelevant target-to-object assignment but not on the basis of some feature regularity. Although participants did not notice the regularity nor the occurrence of the deviation in the sequences, task-irrelevant deviations resulted in increased reaction times. Moreover, compared with physically identical standard displays deviating target-to-object assignments elicited a negative potential in the 246-280 ms time window over posterio-temporal electrode positions which was identified as vMMN. With variable resolution electromagnetic tomography (VARETA) object-related vMMN was localized to the inferior temporal gyrus. Our results support the notion that the visual system automatically structures even task-irrelevant aspects of the incoming information into objects.Frontiers in Human Neuroscience 06/2013; 7:259. DOI:10.3389/fnhum.2013.00259 · 3.63 Impact Factor
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