Method Of Event-related Brain Potentials Research Articles

Word stress representations are language-specific: Evidence from event-related brain potentials.

Understanding speech at the basic levels entails the simultaneous and independent processing of phonemic and prosodic features. While it is well-established that phoneme perception relies on language-specific long-term traces, it is unclear if the processing of prosodic features similarly involves language-specific representations. In the present study, we investigated the processing of a specific prosodic feature, word stress, using the method of event-related brain potentials (ERPs) employing a cross-linguistic approach. Hungarian participants heard disyllabic pseudowords stressed either on the first (legal stress) or on the second (illegal stress) syllable, pronounced either by a Hungarian or a German speaker. Results obtained using a data-driven ERP analysis methodology showed that all pseudowords in the deviant position elicited an Early Differentiating Negativity and a Mismatch Negativity component, except for the Hungarian pseudowords stressed on the first syllable. This suggests that Hungarian listeners did not process the native legal stress pattern as deviant, but the same stress pattern with a nonnative accent was processed as deviant. This implies that the processing of word stress was based on language-specific long-term memory traces.

Electrophysiological Evidence for Elimination of the Positive Bias in Elderly Adults with Depressive Symptoms.

Depressed populations demonstrate a greater tendency to have negative interpretations on ambiguous situations. Cognitive theories concerning depression proposed that such a negative bias plays an important role in developing and maintaining depression. There is now fairly consistent evidence arising from different stimuli and assessment methods that depression is featured by such a bias. The current study aimed to explore the neural signatures associated with the interpretation bias in the elderly with depressive symptoms confronted with different facial expressions using event-related brain potentials (ERPs). Participants were 14 community-dwelling older adults with depressive symptoms assessed by the Center for Epidemiologic Studies Depression scale scores. We collected event-related potentials of their brain compared to that of 14 healthy aged-matched adults. The late positive potential (LPP) was used to examine cognitive-affective processes associated with judgment of emotional facial expressions between the two groups. Old adults with depressive symptoms have much smaller amplitude than healthy older adults irrespective of the prime types. When processing the targets, the two groups showed different patterns regarding the LPP. The healthy control group revealed no differences between ambiguous and happy primes, irrespective of whether the targets were sad or happy facial expressions. However, significant differences were found between happy and sad and between ambiguous and sad primes. Such a pattern indicates a positive bias in healthy elderly adults. Regarding the elderly with depressive symptoms, there were no significant differences between ambiguous versus happy, ambiguous versus sad primes, and happy versus sad primes. Concerning reaction times, there was no group difference. Thus, the findings provide some support for cognitive theories of depression. The current study shows that there is an association between interpretative biases and depressive symptoms in the elderly by using the neuroscientific method of ERPs. The results suggest that ERPs are sensitive to explore the interpretation bias in depressed populations.

Executive control, ERP and pro-inflammatory activity in emotionally exhausted middle-aged employees. Comparison between subclinical burnout and mild to moderate depression

Burnout is a syndrome occurring mainly in individuals with long-term stressful work. The main complaints are emotional exhaustion and reduced performance. Burnout also largely overlaps with depression. Both are characterized by increased incidence of infections due to dysregulation of the immune system, overexpression of pro-inflammatory cytokines and cognitive deficits, particularly related to executive functions. To distinguish between burnout and depression already at the pre-clinical stage, the present double-blinded study compared immunological and cognitive parameters in seventy-six employees from emotionally demanding occupations who were post-hoc subdivided into two groups scoring low (EE−) and high (EE+) in emotional exhaustion and low (DE−) and high (DE+) in depression. Immunological parameters were measured from blood samples. Executive functions were studied by analyzing event-related brain potentials (ERPs) and performance during a task switching paradigm. Psychosocial job parameters were measured with standardized questionnaires.Burnout and mild to moderate depression largely overlapped. However, several subjects showed burnout without depressive symptoms. Higher levels of the pro-inflammatory cytokines IL-6 and IL-12 were correlated with burnout severity and depressive symptoms in male individuals. In the switch task a trend for lower performance in the EE+ vs. EE− group and no difference between DE+ and DE− groups were found. In the ERPs, however, differences were observed which distinguished between subclinical burnout and depression: the terminal contingent negative variation (CNV), indicating preparatory activity and the P3b, related to allocation of cognitive resources were generally reduced in EE+ vs. EE−, whereas no differences were found in the DE+ vs. DE− groups. The frontal P3a was selectively reduced in switch trials in the EE+ vs. EE− group and showed only a trend in DE+ vs. DE−, indicating impairment of executive control in subclinical burnout. Taken together, the results unveil specific immunological changes and declines in brain functions in employees with subclinical burnout that are not apparent in persons with moderate depression. Hence, the combination of immunological, behavioral and ERP methods renders a promising method for distinguishing both syndromes and for improving an early diagnosis of burnout before a clinical stage is reached.

Latencies of the Sensory and Cognitive Components of Event-Related Potentials on Perception of Verbal Stimuli in Health and Schizophrenia

We report here studies of the early and later stages of cerebral information processes during passive reading of concrete words in healthy subjects and patients with schizophrenia using an event-related brain potentials method. Comparative analysis of the P100, N170, P200, and P300 components in the implicit situation showed that the latencies of the early components P100 and N170 were shorter in schizophrenia patients, while the latencies of the later P200 and P300 components were longer than those in healthy subjects. This suggests that schizophrenia involves a deficit in automated sensory processing of the stimulus, apparent as a shorter latency for the sensory components of the event-related potential, with the result that sensory analysis of the stimulus was incomplete and imprecise. The negative correlations between the latencies of the P100 and P200 components (“recognition potentials”) detected here in healthy subjects supported the hypothesis that the longer-lasting sensory processing of verbal stimuli shortens the time taken for its recognition. In schizophrenia patients, the ratio of the durations of the sensory and cognitive components of the event-related potential was impaired. A positive correlation was found between measures of the early and late components of potentials, perhaps because of the presence of nonsensory elements in the structure of the early components of event-related potentials.

Ereigniskorrelierte Potenziale (EKPs)

AbstractIn this article we give a short introduction to the online method of event-related (brain) potentials (ERPs) and their importance for our understanding of language structure and grammar. This methodology places high demands on (technical) requirements for laboratory equipment as well as on the skills of the investigator. However, the high costs are relatively balanced compared to the advantages of this experimental method. By using ERPs, it becomes possible to monitor the electrophysiological brain activity associated with speech processing in real time (millisecond by millisecond) and to draw conclusions on human language processing and the human parser.First, we present briefly how this method works and how ERPs can be classified (Section 1 and 2). In the following, we show that the ERP method can be used to study the processing of e. g. semantic, pragmatic and syntactic information (Section 3). Crucial for our discussion will be the interpretation of the so-called ERP components and their connection and importance for psycholinguistics and theoretical linguistics. In our presentation, we emphasize, that the electrophysiological brain activity in relation to specific (e. g. linguistic) stimuli can be used to identify distinct processes, which give a deeper insight into the different processing steps of language. At the end of this article (Section 4), we present some results from ERP studies of German negative-polar elements. Additionally, we highlight the advantage and benefits of an alternative method to analyze ERP data compared to the more ‘classical’ average technique.

Increased attention but more efficient disengagement: Neuroscientific evidence for defensive processing of threatening health information.

Previous studies indicate that people respond defensively to threatening health information, especially when the information challenges self-relevant goals. The authors investigated whether reduced acceptance of self-relevant health risk information is already visible in early attention processes, that is, attention disengagement processes. In a randomized, controlled trial with 29 smoking and nonsmoking students, a variant of Posner's cueing task was used in combination with the high-temporal resolution method of event-related brain potentials (ERPs). Reaction times and P300 ERP. Smokers showed lower P300 amplitudes in response to high- as opposed to low-threat invalid trials when moving their attention to a target in the opposite visual field, indicating more efficient attention disengagement processes. Furthermore, both smokers and nonsmokers showed increased P300 amplitudes in response to the presentation of high- as opposed to low-threat valid trials, indicating threat-induced attention-capturing processes. Reaction time measures did not support the ERP data, indicating that the ERP measure can be extremely informative to measure low-level attention biases in health communication. The findings provide the first neuroscientific support for the hypothesis that threatening health information causes more efficient disengagement among those for whom the health threat is self-relevant.

Effects of Musical Expertise and Boundary Markers on Phrase Perception in Music

A neural correlate for phrase boundary perception in music has recently been identified in musicians. It is called music closure positive shift ("music CPS") and has an equivalent in the perception of speech ("language CPS"). The aim of the present study was to investigate the influence of musical expertise and different phrase boundary markers on the music CPS, using event-related brain potentials (ERPs) and event-related magnetic fields (ERFs). Musicians and nonmusicians were tested while listening to binary phrased melodies. ERPs and ERFs of both subject groups differed considerably from each other. Phrased melody versions evoked an electric CPS and a magnetic CPSm in musicians, but an early negativity and a less pronounced CPSm in nonmusicians, suggesting different perceptual strategies for both subject groups. Musicians seem to process musical phrases in a structured manner similar to language. Nonmusicians, in contrast, are thought to detect primarily discontinuity in the melodic input. Variations of acoustic cues in the vicinity of the phrase boundary reveal that the CPS is influenced by a number of parameters that are considered to indicate phrasing in melodies: pause length, length of the last tone preceding the pause, and harmonic function of this last tone. This is taken as evidence that the CPS mainly reflects higher cognitive processing of phrasing, rather than mere perception of pauses. Furthermore, results suggest that the ERP and MEG methods are sensitive to different aspects within phrase perception. For both subject groups, qualitatively different ERP components (CPS and early negativity) seem to reflect a top-down activation of general but different phrasing schemata, whereas quantitatively differing MEG signals appear to reflect gradual differences in the bottom-up processing of acoustic boundary markers.

Effects of Musical Expertise and Boundary Markers on Phrase Perception in Music

Abstract A neural correlate for phrase boundary perception in music has recently been identified in musicians. It is called music closure positive shift (“music CPS”) and has an equivalent in the perception of speech (“language CPS”). The aim of the present study was to investigate the influence of musical expertise and different phrase boundary markers on the music CPS, using event-related brain potentials (ERPs) and event-related magnetic fields (ERFs). Musicians and nonmusicians were tested while listening to binary phrased melodies. ERPs and ERFs of both subject groups differed considerably from each other. Phrased melody versions evoked an electric CPS and a magnetic CPSm in musicians, but an early negativity and a less pronounced CPSm in nonmusicians, suggesting different perceptual strategies for both subject groups. Musicians seem to process musical phrases in a structured manner similar to language. Nonmusicians, in contrast, are thought to detect primarily discontinuity in the melodic input. Variations of acoustic cues in the vicinity of the phrase boundary reveal that the CPS is influenced by a number of parameters that are considered to indicate phrasing in melodies: pause length, length of the last tone preceding the pause, and harmonic function of this last tone. This is taken as evidence that the CPS mainly reflects higher cognitive processing of phrasing, rather than mere perception of pauses. Furthermore, results suggest that the ERP and MEG methods are sensitive to different aspects within phrase perception. For both subject groups, qualitatively different ERP components (CPS and early negativity) seem to reflect a top-down activation of general but different phrasing schemata, whereas quantitatively differing MEG signals appear to reflect gradual differences in the bottom-up processing of acoustic boundary markers.

Phonotactic Knowledge and Lexical-Semantic Processing in One-year-olds: Brain Responses to Words and Nonsense Words in Picture Contexts

During their first year of life, infants not only acquire probabilistic knowledge about the phonetic, prosodic, and phonotactic organization of their native language, but also begin to establish first lexical-semantic representations. The present study investigated the sensitivity to phonotactic regularities and its impact on semantic processing in 1-year-olds. We applied the method of event-related brain potentials to 12- and 19-month-old children and to an adult control group. While looking at pictures of known objects, subjects listened to spoken nonsense words that were phonotactically legal (pseudowords) or had phonotactically illegal word onsets (nonwords), or to real words that were either congruous or incongruous to the picture contents. In 19-month-olds and in adults, incongruous words and pseudowords, but not nonwords, elicited an N400 known to ref lect mechanisms of semantic integration. For congruous words, the N400 was attenuated by semantic priming. In contrast, 12-month-olds did not show an N400 difference, neither between pseudo- and nonwords nor between incongruous and congruous words. Both 1-year-old groups and adults additionally displayed a lexical priming effect for congruous words, that is, a negativity starting around 100 msec after words onset. One-year-olds, moreover, displayed a phonotactic familiarity effect, that is, a widely distributed negativity starting around 250 msec in 19-month-olds but occurring later in 12-month-olds. The results imply that both lexical priming and phonotactic familiarity already affect the processing of acoustic stimuli in children at 12 months of age. In 19-month-olds, adult-like mechanisms of semantic integration are present in response to phonotactically legal, but not to phonotactically illegal, nonsense words, indicating that children at this age treat pseudowords, but not nonwords, as potential word candidates.

Electrophysiology of normal and pathological language processing

The paper describes the three language-related event-related brain potentials (ERP) components: the N400 correlated with processes of semantic integration, the early mainly left accentuated anterior negativity correlated with initial structure building processes and the P600 reflecting processes of syntactic integration. These components are functionally specified with respect to normal comprehension. Moreover, the modulation of these components as well as their absence is discussed with respect to pathological language behavior. It is shown that the high temporal resolution of the ERP method allows not only to differentiate between early and late syntactic processes in normals, but also to specify the pathological changes of particular processes in patient groups.

The application of cognitive event-related brain potentials (ERPs) in language-impaired individuals: review and case studies

There is a substantial body of basic research that has utilized ERPs to investigate the neurological basis of cognition. This research has, in turn, led to the development of practical applications of cognitive ERPs in patient populations. In particular, recent work has focused on the development of ERP-based assessment measures for the neuropsychological assessment of dyslexia and language impairments secondary to stroke. This review describes the innovative assessment methods program (IAMP), an initiative to utilize ERPs for a neuropsychological assessment of patients who cannot be evaluated by traditional methods. The success of this program has demonstrated that ERPs can be used to reliably evaluate an individual’s reading and speech comprehension abilities, independent of behavioral and speech production impediments. In contrast to traditional neuropsychological assessment, these ERP methods can discern the cognitive strategies used by an individual to perform a task.