Search results for "MISMATCH NEGATIVITY"
showing 10 items of 182 documents
Examining task-dependencies of different attentional processes as reflected in the P3a and reorienting negativity components of the human event-relat…
2005
Abstract Unexpected changes in task-irrelevant auditory stimuli are capable to distract processing of task-relevant visual information. This effect is accompanied by the elicitation of event-related potential (ERP) components associated with attentional orientation, i.e. P3a and reorienting negativity (RON). In the present study we varied the demands of a visual task in order to test whether the RON component – as an index of attentional reorientation after distraction – is confined to a semantic task requiring working memory. In two ERP experiments we applied an auditory-visual distraction paradigm in which subjects were instructed to discriminate visual stimuli preceded by a task-irreleva…
Position but not color deviants result in visual mismatch negativity in an active oddball task.
2009
Changes in the visual environment might be detected automatically. This function is provided by the sensory systems and showed, for instance, by the pop-out phenomenon. Automatic change detection is also observable within visual oddball paradigms, where rare changes are introduced in an irrelevant stimulus feature; the detection of deviant stimuli is accompanied by a negative component (so-called visual mismatch negativity) in the human event-related brain potential. In this study, the deviating stimulus feature was embedded in a task-relevant object presented in the focus of attention. With this, visual mismatch negativity was observable only with position deviants presented in the upper v…
Amplitude envelope correlation detects coupling among incoherent brain signals.
2000
Event-related potentials (ERPs) to changes in the visual environment were recorded in rabbits. In the oddball condition, infrequently presented (deviant) stimuli occurred in a series of frequently presented (standard) stimuli. In the deviant-alone condition, standards were omitted. ERPs to oddball-deviants differed from those to standards in all recording sites (cerebellar cortex, visual cortex, dentate gyrus). No corresponding differences were found between ERPs to deviants in the oddball condition and those in the deviant-alone condition. However, because ERPs to deviants in the deviant-alone condition and those to standards did not differ either, ERPs to stimulus changes in the oddball c…
Preattentive and attentive responses to changes in small numerosities of tones in adult humans
2016
The brain hosts a primitive number sense to non-symbolically represent numerosities of objects or events. Small exact numerosities (~4 or less) can be individuated in parallel. In contrast, large numerosities (more than ~4) can only be approximated. However, whether small numerosities can be approximated without their parallel individuation remains unclear. Parallel individuation is suggested to be an attentive process and numerical approximation an automatic process. We, therefore, tested whether small numerosities can be represented preattentively. We recorded adult humans׳ event-related potentials (ERPs) and behavioral responses to 300-ms sequences of six tones (each of either 440 Hz or …
ERP and EOG responses elicited by deviant tones when presented with and without standard tones to reading subjects
2002
Event-related potentials (ERPs) and horizontal electro-oculograms (HEOGs) were recorded in 11 subjects to infrequently presented spatially deviant tones (oddball-deviants) embedded in a series of frequently presented standard tones and also to these deviant tones when presented without the standard tones (alone-deviants). Subjects were instructed to read a self-selected book during the stimulus presentation. The mismatch negativity (MMN), a component of the ERP, was elicited by the oddball-deviants, whereas ERPs to the alone-deviants were characterized by a prominent N1. In an additional counting condition (subjects counting the oddball-deviants), the MMN to the oddball-deviants was followe…
From spatial acoustic changes to attentive behavioral responses within 200 ms in humans
1999
Human event-related potentials (ERPs) and electro-oculograms (EOGs) were recorded in 14 subjects presented with spatially deviant tones in a series of standard tones. In separate sessions, they were instructed to read a book, to count the deviant tones, and to respond to the deviant tones by shifting the eyes towards them from the standard tone source. When reading a book, the mismatch negativity (MMN) of ERP, reflecting pre-attentive detection of acoustic changes, was elicited to the deviant tones at approximately 105-180 ms. No deviance related EOGs were observed in the reading or counting conditions. When the subjects responded behaviorally to the deviant tones, EOGs revealed that the ey…
Bottom-up influences on working memory: behavioral and electrophysiological distraction varies with distractor strength.
2004
Abstract. The present study investigates bottom-up effects serving the optimal balance between focusing attention on relevant information and distractibility by potentially significant events outside the focus of attention. We tested whether distraction, indicated by behavioral and event-related brain potential (ERP) measures, varies with the strength of task-irrelevant deviances. Twenty subjects performed a tone-duration discrimination task (200 or 400 ms sinusoidal tones presented equiprobably). The stimuli were presented with frequent standard (p = 0.84; 1000 Hz) or infrequent deviant (p = 0.16) pitch. These task-irrelevant pitch changes consisted in a frequency increase/decrease of 1%,…
Auditory Mismatch Negativity and Repetition Suppression Deficits in Schizophrenia Explained by Irregular Computation of Prediction Error
2015
Background The predictive coding model is rapidly gaining attention in schizophrenia research. It posits the neuronal computation of residual variance (‘prediction error’) between sensory information and top-down expectation through multiple hierarchical levels. Event-related potentials (ERP) reflect cortical processing stages that are increasingly interpreted in the light of the predictive coding hypothesis. Both mismatch negativity (MMN) and repetition suppression (RS) measures are considered a prediction error correlates based on error detection and error minimization, respectively. Methods Twenty-five schizophrenia patients and 25 healthy controls completed auditory tasks designed to el…
Age dependent changes of distractibility and reorienting of attention revisited: an event-related potential study.
2012
Adults of three age groups (18-27, 39-45, and 59-66 years) performed an auditory duration discrimination task with short (200 ms) or long (400 ms) sinusoidal tones. Performance was highly accurate and reaction times were on the same level in all groups, indicating no differences in auditory duration processing. Task irrelevant rare changes of the frequency of the stimuli were introduced to check whether the subjects, firstly, were distracted by changes in the environment while focusing on the task relevant information (indicated by prolonged responses), and, secondly, could re-focus on the relevant task after distraction. The results show that a distraction effect is present in all groups. …
Neural discrimination of nonprototypical chords in music experts and laymen:an MEG study
2009
Abstract At the level of the auditory cortex, musicians discriminate pitch changes more accurately than nonmusicians. However, it is not agreed upon how sound familiarity and musical expertise interact in the formation of pitch-change discrimination skills, that is, whether musicians possess musical pitch discrimination abilities that are generally more accurate than in nonmusicians or, alternatively, whether they may be distinguished from nonmusicians particularly with respect to the discrimination of nonprototypical sounds that do not play a reference role in Western tonal music. To resolve this, we used magnetoencephalography (MEG) to measure the change-related magnetic mismatch response…