Activation in the anterior left auditory cortex associated with phonological analysis of speech input: localization of the phonological mismatch negativity response with MEG

Background. The mismatch negativity (MMN) brainwave indexes novelty detection. MMN to infrequent pitch (pMMN) and duration (dMMN) deviants is reduced in long-term schizophrenia. Although not reduced at first psychosis, pMMN is inversely associated with left hemisphere Heschl’s gyrus (HG) gray matter volume within 1 year of first hospitalization for schizophrenia-spectrum psychosis, consistent with pathology of left primary auditory cortex early in disease course. We examined whether the relationship was present earlier, at first psychiatric contact for psychosis, and whether the same structural-functional association was apparent for dMMN. Method. Twenty-seven first-episode schizophrenia-spectrum (FESz) and 27 matched healthy comparison (HC) individuals were compared. EEG-derived pMMN and dMMN were measured by subtracting the standard tone waveform (80%) from the pitch- and duration-deviant waveforms (10% each). HG volumes were calculated from T1-weighted structural magnetic resonance imaging using Freesurfer. Results. In FESz, pMMN amplitudes at Fz were inversely associated with left HG (but not right) gray matter volumes, and dMMN amplitudes were associated significantly with left HG volumes and at trend-level with right HG. There were no structural-functional associations in HC. Conclusions. pMMN and dMMN index gray matter reduction in left hemisphere auditory cortex early in psychosis, with dMMN also marginally indexing right HG volumes. This suggest conjoint functional and structural pathology that affects the automatic detection of novelty with varying degrees of penetrance prior to psychosis. These brainwaves are sensitive biomarkers of pathology early in the psychotic disease course, and may serve as biomarkers of disease progression and as therapeutic outcome measures.

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Mismatch Negativity and Stimulus-Specific Adaptation in Animal Models

Journal of Psychophysiology ◽

10.1027/0269-8803.21.34.214 ◽

2007 ◽

Vol 21 (3-4) ◽

pp. 214-223 ◽

Cited By ~ 120

Author(s):

Israel Nelken ◽

Nachum Ulanovsky

Keyword(s):

Animal Models ◽

Auditory Cortex ◽

Change Detection ◽

Neural Activity ◽

Mismatch Negativity ◽

Single Neuron ◽

Neural Processing ◽

Sensory Coding ◽

Methodological Issues ◽

Specific Adaptation

Animal models of MMN may serve both to further our understanding of neural processing beyond pure sensory coding and for unraveling the neural and pharmacological processes involved in the generation of MMN. We start this review by discussing the methodological issues that are especially important when pursuing a single-neuron correlate of MMN. Correlates of MMN have been studied in mice, rats, cats, and primates. Whereas essentially all of these studies demonstrated the presence of stimulus-specific adaptation, in the sense that responses to deviant tones are larger than the responses to standard tones, the presence of real MMN has been established only in a few. We argue for the use of more and better controls in order to clarify the situation. Finally, we discuss in detail the relationships between stimulus-specific adaptation of single-neuron responses, as established in the cat auditory cortex, and MMN. We argue that this is currently the only fully established correlate of true change detection, and hypothesize that it precedes and probably induces the neural activity that is eventually measured as MMN.

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Neural origin of mismatch negativity-like response in rat auditory cortex

Neuroscience Research ◽

10.1016/j.neures.2010.07.1217 ◽

2010 ◽

Vol 68 ◽

pp. e273-e274

Author(s):

Tomoyo Isoguchi ◽

Ryohei Kanzaki ◽

Hirokazu Takahashi

Keyword(s):

Auditory Cortex ◽

Mismatch Negativity ◽

Neural Origin

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Event-Related Potentials to Infrequent Changes in Synthesized Phonetic Stimuli

Journal of Cognitive Neuroscience ◽

10.1162/jocn.1990.2.4.344 ◽

1990 ◽

Vol 2 (4) ◽

pp. 344-357 ◽

Cited By ~ 81

Author(s):

Mikko Sams ◽

Reijo Aulanko ◽

Olli Aaltonen ◽

Risto Näätänen

Keyword(s):

Neural Networks ◽

Auditory Cortex ◽

Auditory Stimulus ◽

Mismatch Negativity ◽

Event Related Potentials ◽

Related Potentials ◽

Stimulus Features

Event-related potentials (ERPs) to synthetic consonant–vowel syllables were recorded. Infrequent changes in such a syllable elicited a "mismatch negativity" as well as an enhanced N100 component of the ERP even when subjects did not pay attention to the stimuli. Both components are probably generated in the supratemporal auditory cortex suggesting that in these areas there are neural networks that are automatically activated by speech-specific auditory stimulus features such as formant transitions.

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