Oddball Condition Research Articles

Mismatch negativity to pitch contours is influenced by language experience

A cross-language study utilizing the mismatch negativity (MMN) evoked response was conducted to explore the influence of language experience on the preattentive cortical processing of linguistically relevant pitch contours. Chinese and English subjects were presented with Mandarin Chinese tones while the mismatch negativity (MMN) response was elicited using a passive oddball paradigm. Two oddball conditions were constructed with a common deviant, a low falling rising contour tone (T3). One condition consisted of two tones that are acoustically similar to one another (T2/T3: T2, high rising contour = standard). The other condition consisted of two tones that are acoustically dissimilar to one another (T1/T3: T1, high level = standard). These tonal pairs enabled us to assess whether different degrees of similarity between pitch movements exert a differential influence on preattentive pitch processing. Results showed that the mean MMN amplitude of the Chinese group was larger than that of the English group for the T1/T3 condition. No group differences were found for the T2/T3 condition. The mean MMN amplitude was larger for the T1/T3 relative to the T2/T3 condition for the Chinese group only. By virtue of these language group differences, we infer that early cortical processing of pitch contours may be shaped by the relative saliency of acoustic dimensions underlying the pitch patterns of a particular language.

Oddball and incongruity effects during Stroop task performance: A comparative fMRI study on selective attention

The aim of this fMRI study was to investigate and compare the neural mechanisms of selective attention during two different operationalizations of competition between task-relevant and task-irrelevant information: Stroop-incongruity and oddballs. For this purpose, we employed a Stroop-like oddball task in which subjects responded to the font size of presented word stimuli. Stroop-incongruity was created by (response-)incongruent word information while oddballs comprised low-frequency events in a task-irrelevant, unattended dimension. Thereby, in order to elucidate the influence of processing domain from which competition emanates, oddball conditions were created in two different attribute dimensions, color and word meaning. Either oddball condition was expected to evoke an orienting response, which participants would have to override in order to maintain adequate performance. Incongruent Stroop trials were expected to produce Stroop-interference so that subjects would have to override the predominant tendency to read and respond to word meaning. All competition conditions exhibited significantly prolonged reaction times compared to control trials, demonstrating that our experimental manipulation was indeed effective. fMRI data analyses delineated two discriminative components of competition: one component mainly related to motor preparation and another, primarily attentional component. Regarding the first, Stroop-interference increased activation mainly in regions implicated in motor control or response preparation. Regarding the second, Word-oddballs increased activation in a frontoparietal “attention network”. Furthermore, Word-oddballs and Color-oddballs exhibited striking activation overlap mainly in prefrontal regions but also in posterior processing areas. Here, the data emphasized a prominent role of posterior lateral PFC in implementing top–down attentional control.

Active attention modulates passive attention-related neural responses to sudden somatosensory input against a silent background

To reveal whether active attention modulates neuronal responses related to passive attention to somatosensory stimuli presented suddenly against a silent background, we examined the passive attention-related change in amplitude of the event-related brain potentials (ERPs), caused by temporal infrequency of stimuli. Eighteen healthy subjects performed passive and active attention tasks in two stimulus conditions. In the oddball condition, frequent (80%, standard) and infrequent (20%, deviant) electrical stimuli were randomly delivered to the second and third digits of the left hand. In the deviant-alone condition, the deviant stimulus (deviant-alone stimulus) was delivered with the same timing and sequence as in the oddball condition without standard stimuli. The P100, N140, and P200 elicited by the deviant-alone stimulus were enhanced in amplitude compared to those evoked by the oddball deviant stimulus in both the active and passive tasks. Moreover, active attention increased the enhancement of P100 and N140. The difference waveform (deviant-alone minus oddball deviant) provided similar findings. In conclusion, active attention enhances neural responses related to passive shifts of attention to somatosensory signals suddenly presented against a silent background. The results indicate that top-down signals for detecting target stimuli interact with passive shifts of attention caused by bottom-up signals.

Evaluation of multi-attribute auditory discrimination in dyslexia with the mismatch negativity

Objective Dyslexia is associated with impairments in the phonological system or with more general auditory dysfunctions. We determined the discrimination of 5 sound contrasts (pitch, duration, intensity, location, and the presence of a gap) in dyslexia with the mismatch negativity (MMN). Methods We compared MMNs of 9 adult dyslexic and 11 control subjects with a new 5-deviant paradigm which enables one to assess the discrimination of each of these features in 15 min. Also, a control oddball condition with pitch and duration deviants was included. In the new paradigm, all deviant stimuli are presented in the same stimulus block so that the standard stimuli, of which there are 50%, alternate with the deviant stimuli. Results In the 5-deviant paradigm, a diminished pitch-MMN and an enhanced location-MMN were found in dyslexic individuals. Furthermore, pitch and duration MMNs in this and in the oddball paradigms suggested that smaller MMNs are elicited in the new than oddball paradigm in dyslexic subjects. Conclusions Pitch discrimination is impaired in dyslexia. However, location discrimination, not addressed previously with MMN, is enhanced. Furthermore, dyslexic subjects are more impaired in detecting changes in sound streams with than without variation. Significance In dyslexia research, the new 5-deviant MMN paradigm is feasible and even more sensitive than the traditional oddball paradigm.

Effects of Self-Evaluation on the P300 Event-Related Potential

The effects of self evaluation on the P300 event-related potential (ERP) were explored with 56 participants (16 men, 40 women; M age = 23.4 yr., SD = 1.2) across three conditions. The conditions included (1) a standard ERP auditory oddball discrimination between a random target (15% occurrence) and standard stimuli (85% occurrence), (2) the oddball task followed by the additional cognitive task of maintaining a mental count of the target tones, and (3) the oddball task followed by the additional cognitive task of self-evaluating whether they felt surprised by the current occurrence of the target tone. The added cognitive requirements for Conditions 2 and 3 required the subjects to maintain a cognitive readiness for the secondary stimulus-related task during their sensory discrimination response for the standard oddball task. During the self-evaluation condition, the P300 amplitude was significantly larger across all recording locations than the regular oddball condition and the cognitive count condition.

Event-related potentials in an auditory oddball situation in the rat

Evoked potentials were recorded from the auditory cortex of both freely moving and anesthetized rats when deviant sounds were presented in a homogenous series of standard sounds (oddball condition). A component of the evoked response to deviant sounds, the mismatch negativity (MMN), may underlie the ability to discriminate acoustic differences, a fundamental aspect of auditory perception. Whereas most MMN studies in animals have been done using simple sounds, this study involved a more complex set of sounds (synthesized vowels). The freely moving rats had previously undergone behavioral training in which they learned to respond differentially to these sounds. Although we found little evidence in this preparation for the typical, epidurally recorded, MMN response, a significant difference between deviant and standard evoked potentials was noted for the freely moving animals in the 100–200 ms range following stimulus onset. No such difference was found in the anesthetized animals.

The human brain processes visual changes that are not cued by attended auditory stimulation

Event-related potentials (ERPs) to visual stimuli were recorded from the scalp of eight adult humans performing a task in which they counted vowels from a heard story. In the oddball condition, a repeated (standard) light bar of 50 ms in duration was rarely ( P = 0.1) replaced by a (deviant) one differing in orientation from the standard. In the control condition, standards were simply omitted from the series and only (alone-) deviants retained. In both conditions, visual stimuli were asynchronous with auditory-task-relevant stimuli. ERPs to deviants significantly differed in amplitude from those to standards in the midline electrodes centrally, parietally and occipitally at 160–200 ms from stimulus onset. Occipitally, such a difference was absent between ERPs to alone-deviants and those to standards. The occipital differential ERPs to deviants, which thus could be found only when standards were present in the series, are discussed in the context of the mismatch negativity (MMN).

ERP Effects of Subject—Verb Agreement Violations in Patients with Broca's Aphasia

This article presents electrophysiological data on on-line syntactic processing during auditory sentence comprehension in patients with Broca's aphasia. Event-related brain potentials (ERPs) were recorded from the scalp while subjects listened to sentences that were either syntactically correct or contained violations of subject-verb agreement. Three groups of subjects were tested: Broca patients (n = 10), nonaphasic patients with a right-hemisphere (RH) lesion (n = 5), and healthy aged-matched controls (n = 12). The healthy, control subjects showed a P600/SPS effect as response to the agreement violations. The nonaphasic patients with an RH lesion showed essentially the same pattern. The overall group of Broca patients did not show this sensitivity. However, the sensitivity was modulated by the severity of the syntactic comprehension impairment. The largest deviation from the standard P600/SPS effect was found in the patients with the relatively more severe syntactic comprehension impairment. In addition, ERPs to tones in a classical tone oddball paradigm were also recorded. Similar to the normal control subjects and RH patients, the group of Broca patients showed a P300 effect in the tone oddball condition. This indicates that aphasia in itself does not lead to a general reduction in all cognitive ERP effects. It was concluded that deviations from the standard P600/SPS effect in the Broca patients reflected difficulties with on-line maintaining of number information across clausal boundaries for establishing subject-verb agreement.

With long intervals, inter-stimulus interval is the critical determinant of the human P300 amplitude

Previous research, using short inter-stimulus intervals (1–4 s), suggests that the P300 of the human event-related potential during oddball and single-stimulus tasks is mainly affected by target-to-target interval (TTI). The present study tested the validity of this claim at longer intervals in a learning task. Participants were assigned to either an oddball task with an inter-stimulus interval (ISI) of 9–20 s or a single-stimulus task with an ISI of 9–20 or 40–90 s and had to learn when to respond to the stimuli. In the oddball task, the target elicited larger amplitudes than did the standard. When comparing the stimuli from the short- and long-ISI conditions with the target from the oddball condition, it was found that the P300 was more positive at long-ISI stimuli than at short-ISI stimuli or oddball targets, and short-ISI stimuli and oddball targets elicited equally large P300 amplitudes. These results suggest that, in oddball tasks with long intervals, besides cognitive factors, ISI rather than TTI affects the P300 amplitude.

Event-related potentials elicited by non-target tones in an auditory oddball paradigm in schizophrenia

It has been reported that in event-related potentials (ERPs) elicited by non-target tones in oddball paradigms, the superimposition of a negative component on the descending slope of N100 depends on subjects’ attention to the task. We tested the possibility that this attention-related change is abnormal for patients with schizophrenia. ERPs induced by non-target, frequent tones were measured for 52 patients and 31 healthy controls under two oddball conditions: a passive condition where the subjects were told to disregard the tones, and an active condition where they were instructed to respond to infrequent tones. For both groups, a negative component was superimposed from the descending slope of N100 to the end of P150 (latency, 120–200 ms) for the active condition. The peak latency of this attention-related negative component was longer for the patients than for the controls, while the amplitude showed no group difference. In addition, the active P150 for the patients was more enlarged than that for the controls. Furthermore, the active P150 amplitude for the patients correlated positively with the score for the negative symptom factor of the Positive and Negative Syndrome Scale. These findings suggest that the enlargement of non-target P150 observed in conjunction with the latency prolongation of the attention-related negative component may be a biological marker for the severity of the negative symptoms in schizophrenia.

Visual and auditory event-related brain potentials in schizophrenia

Behavioral research has produced little evidence on sound feature discrimination in neonates. Sensory processes underlying sound perception can be studied using the mismatch negativity (MMN) component of auditory event-related potentials (ERPs), which is not contingent on conscious perception and response. Thus, MMN is suitable for studying newborns, who are difficult to obtain behavioral responses from. The present study thus utilized spectrally rich sounds, known to elicit the most replicable MMN in adults, to investigate newborns’ preattentive analysis of sound duration and frequency changes. An attempt was also made to control for the obligatory ERP effects on the MMN. Three-partial harmonic tones were presented in Duration and in Frequency oddball conditions to 55 newborns. In the other two, Equiprobable duration and Equiprobable frequency, conditions frequency and duration deviants of the oddball paradigms were presented with equal probabilities among sounds of other durations and frequencies. MMN was elicited in 81% of newborns in Frequency oddball condition and in 78% of newborns in Duration oddball condition. No significant amplitude differences between the duration and frequency MMNs were found, but MMN latency was delayed in Duration condition. The obligatory components seemed to contribute significantly to the deviant-standard difference in Duration but not in Frequency condition. The majority of neonates appear to possess effective sound frequency and duration discrimination mechanisms. Their preattentive sound discrimination is facilitated by spectrally rich sound content. The present findings support a change-detection nature of MMN in neonates; however, sound duration-related obligatory effects need to be taken into account in infant MMN studies.

A transient dominance of theta event-related brain potential component characterizes stimulus processing in an auditory oddball task.

Following external stimulation, electroencephalographic (EEG) responses from different frequency bands occur simultaneously, but little is known about whether and how concurrent multi-frequency responses depend on each other during stimulus information processing. The present study assessed the effects of task stimulus relevance on locally co-existent time-frequency components of event-related brain potentials (ERPs). The wavelet entropy (WE) of ERPs was used as an analytical tool because low entropy values correspond to a narrow-band (mono-frequency) activity characterizing highly ordered (regularized) bioelectric states. The minimum of WE in the ERPs (WEmin) was identified to reflect a transient dominance of one particular frequency ERP component over other frequency components. In an auditory oddball condition, effects of stimulus relevance were analyzed for the timing, rate of decrease, and frequency determinants of WEmin in 10 subjects. Major results demonstrate that a highly ordered EEG microstate emerged in response to both target and non-target stimuli, as evidenced by the substantial decrement of ERP entropy. This microstate (1) was short lasting as indexed by the transitory entropy decrease, (2) had a functionally specific time-localization as reflected by stimulus and electrode effects on WEmin latency, and (3) for both stimulus types was determined by a pronounced dominance of locally synchronized theta (4-8 Hz) oscillations. These results reveal a new neuroelectric correlate of stimulus processing and suggest that a theta-dominated microstate in the ERP may reflect a basic processing stage of stimulus evaluation, during which interfering activations from other frequency networks are minimized. In the framework of event-related brain dynamics, this study provides evidence that during stimulus processing, there is an interaction of locally co-existent multiple frequency ERP components. It is characterized by a transitory dominance of synchronized theta oscillations over other frequency ERP components emerging irrespective of stimulus task relevance and frequency ERP content, which may reflect basic processing mechanisms.

Developmental dyslexics show altered allocation of attention in visual classification tasks

Event-related brain potentials (ERPs) were recorded to investigate allocation of attention in adult developmental dyslexics. Twelve adult developmental dyslexics and 12 matched normal controls performed three visual choice reaction tasks. In the passive oddball condition, subjects watched two different simple visual stimuli presented with 87.5 and 12.5% probability. In the active oddball condition, participants responded to the low-probability target stimulus. In the active 50/50-condition, both stimuli were presented with 50% probability and a response was required to the target stimulus only. No group differences emerged for performance, P300 latency or laterality and for N200 amplitude, latency or laterality. An enhancement of P300 amplitude with a frontal distribution was found for NoGo (standard)-stimuli in both active conditions for the dyslexic sample. Results are discussed in the context of deviances in allocation of attentional resources in dyslexic readers.

Memory-based detection of task-irrelevant visual changes.

Colored grating patterns were presented to 8 participants in a passive oddball condition (standard, 87.5% and deviant, 12.5%, differing in their color). In the corresponding multicolor condition, grating patterns of eight different colors were presented, their probabilities set equal both to each other and to that of the deviant in the oddball task. Compared with the ERP response elicited by the standard stimulus, the deviant response was negatively displaced over posterior areas, the difference wave peaking at 136 ms. A similar negative wave was obtained when the ERP response to the deviant was compared with the ERP elicited by the same stimulus in the multicolor condition. This result rules out stimulus- (color-) specific refractoriness as a major factor in the generation of the deviance-related posterior negativity. The observed posterior negativity can therefore be regarded as a visual analog of the mismatch negativity (vMMN).

Event-related potential features indexing central auditory discrimination by newborns

Behavioral research has produced little evidence on sound feature discrimination in neonates. Sensory processes underlying sound perception can be studied using the mismatch negativity (MMN) component of auditory event-related potentials (ERPs), which is not contingent on conscious perception and response. Thus, MMN is suitable for studying newborns, who are difficult to obtain behavioral responses from. The present study thus utilized spectrally rich sounds, known to elicit the most replicable MMN in adults, to investigate newborns’ preattentive analysis of sound duration and frequency changes. An attempt was also made to control for the obligatory ERP effects on the MMN. Three-partial harmonic tones were presented in Duration and in Frequency oddball conditions to 55 newborns. In the other two, Equiprobable duration and Equiprobable frequency, conditions frequency and duration deviants of the oddball paradigms were presented with equal probabilities among sounds of other durations and frequencies. MMN was elicited in 81% of newborns in Frequency oddball condition and in 78% of newborns in Duration oddball condition. No significant amplitude differences between the duration and frequency MMNs were found, but MMN latency was delayed in Duration condition. The obligatory components seemed to contribute significantly to the deviant-standard difference in Duration but not in Frequency condition. The majority of neonates appear to possess effective sound frequency and duration discrimination mechanisms. Their preattentive sound discrimination is facilitated by spectrally rich sound content. The present findings support a change-detection nature of MMN in neonates; however, sound duration-related obligatory effects need to be taken into account in infant MMN studies.

Brain potentials in human patients with extremely severe diffuse brain damage

To test higher cortical functions of neurological patients, oddball tasks are often used in which a frequent and a rare stimulus are randomly presented and a P3 brain wave is recorded to the rare stimulus. We examined 33 patients with extremely severe brain injury. Three oddball conditions were used: with two sine tones (ST), with two complex tones (CT) and with vowels ‘o’ and ‘i’. Across all patients, CT elicited P3 more often than ST, and the occurrence of the P3 after vowels was intermediate. However, among patients who showed a distinct P3 wave, its amplitude in the subgroup with traumatic brain injury was larger to vowels than to CT. In patients with non-traumatic etiology, CT and vowels elicited a P3 of a nearly equal amplitude. Stimuli of sufficient complexity should be used when the P3 technique is applied for assessment of cortical functions in severely impaired patients.

Somatosensory event-related potentials in the rabbit cerebral and cerebellar cortices: a correspondence with mismatch responses in humans

Somatosensory event-related potentials (ERPs) were recorded from the cerebellar (CerCx), somatosensory (SomCx) and visual (VCx) cortices in rabbits in two stimulus conditions. In the oddball condition, airpuffs to two different locations in the rabbit's muzzle corresponded to infrequently presented deviant stimuli (oddball-deviants) interspersed with frequently presented standard stimuli. In the deviant-alone condition, deviants (alone-deviants) were presented without standards. ERPs to oddball-deviants differed significantly from those to standards in CerCx and SomCx, but not in VCx. Furthermore, some of these differences were not found between ERPs to alone-deviants and those to standards. Thus, ERPs to oddball-deviants contributing these differences were dependent on the presence of preceding standards. The results are in line with the elicitation of mismatch negativity-like ERPs to somatosensory changes in humans.

P300 and alpha event‐related desynchronization (ERD)

In the present study we evaluated the relationships between the P300 event-related potential and event-related desynchronization (ERD) of electroencephalographic alpha activity by simultaneously analyzing P300 as well as 7-10- and 10-14-Hz alpha ERD responses from auditory passive and active oddball conditions. We compared the effects of task (target vs. nontarget) and electrode (Fz, Cz, Pz) on P300 and ERD, and correlated P300 amplitude/latency with ERD maximal amplitude/latency across individuals. The major findings were that P300 as well as slow and fast alpha ERD manifested similar task and electrode effects. P300 preceded ERD and predicted individual variance of both slow and fast alpha ERD. The relationships of P300 with alpha ERD were different for the slow and fast alpha frequencies. These findings indicate that P300 and ERD are related such that slow and fast alpha ERDs are specifically guided or modified by the internal event(s) indexed by P300.

Time–Frequency Analysis of Single-Sweep Event-Related Potentials by Means of Fast Wavelet Transform

A time–frequency decomposition was applied to the event-related potentials (ERPs) elicited in an auditory oddball condition to assess differences in cognitive information processing. Analysis in the time domain has revealed that cognitive processes are reflected by various ERP components such as N1, P2, N2, P300, and late positive complex. However, the heterogeneous nature of these components has been strongly emphasized due to simultaneously occurring processes. The wavelet transform (WT), which decomposes the signal onto the time–frequency plane, allows the time-dependent and frequency-related information in ERPs to be captured and precisely measured. A four-octave quadratic B-spline wavelet transform was applied to single-sweep ERPs recorded in an auditory oddball paradigm. Frequency components in delta, theta, and alpha ranges reflected specific aspects of cognitive information processing. Furthermore, the temporal position of these components was related to specific cognitive processes.

Effects of aging on the novelty P3 during attend and ignore oddball tasks

The effects of attention were assessed on novelty P3 amplitude and scalp distribution elicited by environmental sounds in young and elderly volunteers who participated in either actively attended or ignored oddball conditions. For the young, novelty P3 amplitude decreased with time on task during both attend and ignore sequences. Amplitude decrements were greatest at frontal sites during the attend condition, but at all sites during the ignore condition. A reliable amplitude decrement was not observed for the elderly in either the attend or ignore oddball series. The data suggest that attention differentially activates multiple generators that contribute to scalp-recorded novelty P3 activity. The lack of novelty P3 habituation seen in the elderly is consistent with changes in frontal lobe function as age increases.