Search results for "mismatch"

Detrimental noise effects on brain's speech functions.

2009

Background noise has become part of our everyday life in modern societies. Its presence affects both the ability to concentrate and communicate. Some individuals, like children, the elderly, and non-native speakers have pronounced problems in noisy environments. Here we review evidence suggesting that background noise has both transient and Sustained detrimental effects on central speech processing. Studies on the effects of noise on neural processes have demonstrated hemispheric reorganization in speech processing in adult individuals during background noise. During noise, the well-known left hemisphere dominance in speech discrimination became right hemisphere preponderant. Furthermore, l…

Lung Size Mismatch In Bilateral Lung Transplantation Is Associated With Allograft Function And Bronchiolitis Obliterans Syndrome

2011

Deviance detection in sound frequency in simple and complex sounds in urethane-anesthetized rats

2019

Mismatch negativity (MMN), which is an electrophysiological response demonstrated in humans and animals, reflects memory-based deviance detection in a series of sounds. However, only a few studies on rodents have used control conditions that were sufficient in eliminating confounding factors that could also explain differential responses to deviant sounds. Furthermore, it is unclear if change detection occurs similarly for sinusoidal and complex sounds. In this study, we investigated frequency change detection in urethane-anesthetized rats by recording local-field potentials from the dura above the auditory cortex. We studied change detection in sinusoidal and complex sounds in a series of …

Separating mismatch negativity (MMN) from obligatory brain responses for speech and non-speech sounds in school-aged children

2010

Revealing “genuine” mismatch negativity (MMN) in school-aged children

2010

Independent component analysis on the mismatch negativity in an uninterrupted sound paradigm.

2008

We compared the efficiency of the independent component analysis (ICA) decomposition procedure against the difference wave (DW) and optimal digital filtering (ODF) procedures in the analysis of the mismatch negativity (MMN). The comparison was made in a group of 54 children aged 8-16 years. The MMN was elicited in a passive oddball protocol presenting uninterrupted auditory stimulation consisting of two frequent alternating tones (600 and 800 Hz) of 100 ms duration each. Infrequently, one of the 600 Hz tones was shortened to 50 or 30 ms. The event related potentials (ERPs) were decomposed into the MMN-like and non-MMN-like independent components (ICs) through the FastICA algorithm. The ICA …

Event‐related brain potentials to change in rapidly presented acoustic stimuli in newborns

1997

Event-related brain potentials of 28 newborns to pitch change were studied during quiet sleep under stimulus conditions that typically elicit mismatch negativity in adults. Rarely occurring deviant tones of 1100 Hz (probability 12%) were embedded among repeated standard tones of 1000 Hz in an oddball-sequence with an interstimulus interval of 425 ms. Two control conditions were also employed: In the first, the 1100-Hz stimulus was presented alone without the intervening standard stimuli, and in the second the deviant stimulus had a pitch of 1300 Hz. In all conditions the infrequent stimulus elicited in most newborns a slow positive deflection peaking at a latency of 250-350 ms. The response…

Auditory evoked potentials to changes in speech sound duration in anesthetized mice

2018

AbstractElectrophysiological response termed mismatch negativity (MMN) indexes auditory change detection in humans. An analogous response, called the mismatch response (MMR), is also elicited in animals. Mismatch response has been widely utilized in investigations of change detection in human speech sounds in rats and guinea pigs, but not in mice. Since e.g. transgenic mouse models provide important advantages for further studies, we studied processing of speech sounds in anesthetized mice. Auditory evoked potentials were recorded from the dura above the auditory cortex to changes in duration of a human speech sound /a/. In oddball stimulus condition, the MMR was elicited at 53-259 ms laten…

Mismatch negativity (MMN) elicited by changes in phoneme length: A cross-linguistic study

2006

Speech sounds representing different phonetic categories are typically easier to discriminate than sounds belonging to the same category. This phenomenon is referred to as the phoneme boundary effect. We aimed to determine whether, at neural level, this effect is indeed due to crossing the phoneme boundary. The mismatch negativity (MMN) brain response was measured for across- and within-category changes in Finnish phoneme length in native speakers and second-language users of Finnish as well as non-Finnish-speaking subjects. The results showed that the MMN amplitude was enhanced in the native speakers in comparison with the two non-native groups which, in turn, did not differ from each othe…

Auditory cortical and hippocampal local-field potentials to frequency deviant tones in urethane-anesthetized rats: An unexpected role of the sound fr…

2015

Abstract The human brain can automatically detect auditory changes, as indexed by the mismatch negativity of event-related potentials. The mechanisms that underlie this response are poorly understood. We recorded primary auditory cortical and hippocampal (dentate gyrus, CA1) local-field potentials to serial tones in urethane-anesthetized rats. In an oddball condition, a rare (deviant) tone ( p  = 0.11) randomly replaced a repeated (standard) tone. The deviant tone was either lower (2200, 2700, 3200, 3700 Hz) or higher (4300, 4800, 5300, 5800 Hz) in frequency than the standard tone (4000 Hz). In an equiprobability control condition, all nine tones were presented at random ( p  = 0.11). Diffe…