Biomedical subjects

Anja Hahne

Publications and source records attributed to Anja Hahne.

At least 19 recordsLinked to original sources

PubMed2006

Neurodynamics of sentence interpretation: ERP evidence from French.

Sentence interpretation was examined with event-related brain potentials (ERPs). The ERPs were recorded while participants listened to French sentences containing a subject-modifying relative clause (SRC). These were either correct, semantically incorrect, syntactically incorrect, or doubly (syntactically and semantically) incorrect. The semantic anomaly realized as a selectional restriction violation was associated with an N400. The syntactic anomaly realized as a phrase structure violation in the SRC elicited a frontal negativity between 150 and 600 ms. This negativity was more pronounced in the left than in the right hemisphere in the early time window (150-300 ms). In a later time window (300-600 ms), it was more broadly distributed including anterior and posterior regions, but with a maximum over the anterior recording sites. Finally, a centro-parietal late positivity (P600) was found between 600 and 1000 ms. While syntactic and semantic information in the double violation condition did not interact between 150 and 300 ms, they did interact between 300 and 600 ms. This finding supports serial models of sentence processing that postulate an initial autonomous stage of phrase structure building and a late stage of interaction.

Adult↗

PubMed2006

Lexical-semantic processes in children with specific language impairment.

The current study used event-related brain potentials to investigate lexical-semantic processing of words in sentences spoken by children with specific language impairment and children with normal language development. Children heard correct sentences and sentences with a violation of the selectional restriction of the verb. Control children showed an N400 effect followed by a late positivity for the incorrect sentences. In contrast, children with specific language impairment showed no N400 effect but did show a late, broadly distributed positivity. This absence of the N400 effect is due to a relatively large negativity for correct sentences, suggesting weaker lexical-semantic representations of the verbs and their selectional restrictions in children with specific language impairment.

Acoustic Stimulation↗

PubMed2006

Localizing the distributed language network responsible for the N400 measured by MEG during auditory sentence processing.

We studied auditory sentence comprehension using magnetoencephalography while subjects listened to sentences whose correctness they had to judge subsequently. The localization and the time course of brain electrical activity during processing of correct and semantically incorrect sentences were estimated by computing a brain surface current density within a cortical layer for both conditions. Finally, a region of interest (ROI) analysis was conducted to determine the time course of specific locations. A magnetic N400 was present in six spatially different ROIs. Semantic anomalies caused an exclusive involvement of the ventral portion of the left inferior frontal gyrus (BA 47) and left pars triangularis (BA 45). The anterior parts of the superior (BA 22) and inferior (BA 20/21) temporal gyri bilaterally were activated by both conditions. The activation for the correct condition, however, peaked earlier in both left temporal regions (approximately 32 ms). In general, activation due to semantic violations was more pronounced, started later, and lasted longer as compared to correct sentences. The findings reveal a clear left-hemispheric dominance during language processing indicated firstly by the mere number of activated regions (four in the left vs. two in the right hemisphere) and secondly by the observed specificity of the left inferior frontal ROIs to semantic violations. The temporal advantage observed for the correct condition in the left temporal regions is supporting the notion that the established context eases the processing of the final word. Semantically incorrect words that do not fit into the context result in longer integration times.

Adolescent↗

PubMed2006

Brain potentials to morphologically complex words during listening.

This study uses event-related brain potentials (ERPs) to investigate the processing of morphologically regular and irregular words during auditory comprehension. ERPs were recorded, while 23 German-speaking subjects listened to correctly and incorrectly inflected noun plural forms presented in sentential contexts. ERP responses to violations of morphological structure were different to those of lexical (word-level) violations: the former elicited LAN/P600 effects, and the latter an enhanced N400 component relative to the correctly inflected plural forms. This difference replicates previous results from visual ERP studies and supports the distinction between combinatorial and memory-based processing of morphologically complex words. In addition, LAN/P600 effects were found to be more prominent in the auditory domain than in a previous visual study using similar materials.

Adolescent↗

PubMed2006

Model-generated lexical activity predicts graded ERP amplitudes in lexical decision.

Recent neurocognitive studies of visual word recognition provide information about neuronal networks correlated with processes involved in lexical access and their time course (e.g., [Holcomb, Ph.J., Grainger J. and O'Rourke, T. (2002). An Electrophysiological Study of the Effects of Orthographic Neighborhood Size on Printed Word Perception, J. of Cogn. Neurosci. 14 938-950; Binder, J.R., McKiernan, K.A., Parsons, M.E., Westbury, C.F., Possing, E.T., Kaufman, J.N. and Buchanan, L. (2003). Neural Correlates of Lexical Access during Visual Word Recognition, J. Cogn. Neurosci. 15 372-393.]). These studies relate the orthographic neighborhood density of letter strings to the amount of global lexical activity in the brain, generated by a hypothetical mental lexicon as speculated in an early paper by [Jacobs, A.M. and Carr, T.H. (1995). Mind mappers and cognitive modelers: Toward cross-fertilization, Behav. Brain. Sci. 18 362-363]. The present study uses model-generated stimuli theoretically eliciting graded global lexical activity and relates this activity to activation of lexical processing networks using event-related potentials (ERPs). The results from a lexical decision task provide evidence for an effect of lexicality around 350 ms post-stimulus and also a graded effect of global lexical activity for nonwords around 500 ms post-stimulus. The data are interpreted as reflecting two different decision processes: an identification process based on local lexical activity underlying the 'yes' response to words and a temporal deadline process underlying the 'no' response to nonwords based on global lexical activity.

Adult↗

PubMed2006

Phonological activation of category coordinates during speech planning is observable in children but not in adults: evidence for cascaded processing.

There is a long-standing debate in the area of speech production on the question of whether only words selected for articulation are phonologically activated (as maintained by serial-discrete models) or whether this is also true for their semantic competitors (as maintained by forward-cascading and interactive models). Past research has addressed this issue by testing whether retrieval of a target word (e.g., cat) affects--or is affected by--the processing of a word that is phonologically related to a semantic category coordinate of the target (e.g., doll, related to dog) and has consistently failed to obtain such mediated effects in adult speakers. The authors present a series of experiments demonstrating that mediated effects are present in children (around age 7) and diminish with increasing age. This observation provides further evidence for cascaded models of lexical retrieval.

Adult↗

PubMed2006

Morphological processing in a second language: behavioral and event-related brain potential evidence for storage and decomposition.

This study reports the results of two behavioral and two event-related brain potential experiments examining the processing of inflected words in second-language (L2) learners with Russian as their native language. Two different subsystems of German inflection were studied, participial inflection and noun plurals. For participial forms, L2 learners were found to widely generalize the -t suffixation rule in a nonce-word elicitation task, and in the event-related brain potential experiment, they showed an anterior negativity followed by a P600-both results resembling previous findings from native speakers of German on the same materials. For plural formation, the L2 learners displayed different preference patterns for regular and irregular forms in an off-line plural judgment task. Regular and irregular plural forms also differed clearly with regard to their brain responses. Whereas overapplications of the -s plural rule produced a P600 component, overapplications of irregular patterns elicited an N400. In contrast to native speakers of German, however, the L2 learners did not show an anterior negativity for -s plural overapplications. Taken together, the results show clear dissociations between regular and irregular inflection for both morphological subsystems. We argue that the two processing routes posited by dual-mechanism models of inflection (lexical storage and morphological decomposition) are also employed by L2 learners.

Adult↗

PubMed2006

The impact of proficiency on syntactic second-language processing of German and Italian: evidence from event-related potentials.

The present study investigated the role of proficiency in late second-language (L2) processing using comparable stimuli in German and Italian. Both sets of stimuli consisted of simple active sentences including a word category violation, a morphosyntactic agreement violation, or a combination of the two. Four experiments were conducted to study high- and low-proficiency L2 learners of German as well as high- and low-proficiency L2 learners of Italian. High-proficiency L2 learners in both languages showed the same event-related potential (ERP) components as native speakers for all syntactic violations. For the word category violation, they displayed an early anterior negativity (ELAN), an additional negativity reflecting reference-related processes, and a late P600 evidencing processes of reanalysis. For the processing of the morphosyntactic error, an anterior negativity (LAN) and a P600 were observed, whereas for the combined violation, the same ERP components were found as in the pure category violation. In high-proficiency L2 learners, the timing of the processing steps was equivalent to that of native speakers, although some amplitude differences were present. Low-proficiency L2 learners, however, showed qualitative differences in the agreement violation characterized by the absence of the LAN and quantitative differences reflected in a delayed P600 in every violation condition. These findings emphasize that with a high proficiency, late L2 learners can indeed show native-like neural responses with the timing approximating that of native speakers. This challenges the idea that there are fundamental differences in language processing in the brain between natives and late L2 learners.

Adult↗

PubMed2005

When word category information encounters morphosyntax: an ERP study.

The present study investigated the relationship between two different syntactic information types, namely word category and morphosyntax. The event-related brain potential (ERP) pattern of acoustically presented sentences containing two syntactic anomalies (word category and subject-verb agreement) was compared to the ERP response to sentences containing a single violation. The ERPs for the agreement violation revealed a left anterior negativity (LAN) indicating the detection of the morphosyntactic error, followed by a P600 reflecting processes of reanalysis. The ERPs for both the category and the combined violation showed an early negativity reflecting processes of phrase structure building, followed by a P600 indicating syntactic reanalysis. Additionally, a broadly distributed negativity following the early negativity and preceding the P600 was observed. This ERP component is suggested to reflect reference specification processes arising from the specific sentence structure used in the present study. The ERP pattern for the combined violation suggests no additivity or interaction between the two syntactic anomalies in the early time windows (early negativity, reference-related negativity, and LAN), whereas interactive effects are observed in a late time range (P600).

Adolescent↗

PubMed2005

Reduced stress pattern discrimination in 5-month-olds as a marker of risk for later language impairment: neurophysiologial evidence.

The study at hand investigates prosodic abilities of infants as early predictors of Specific Language Impairment (SLI), which is commonly diagnosed at a later age. The study is based on the hypothesis that the prosodic abilities of infants at risk for SLI are less elaborated than those of controls due to less efficient processing of the relevant acoustic cues. One of the most critical prosodic cues for word segmentation is stress pattern. In German as well as in English, the most frequent stress pattern of bisyllabics is the trochee, in which stress is placed on the first syllable. Using a passive oddball design, German 5-month-olds were examined with respect to their ability to discriminate different stress patterns of bisyllabics. Infants were grouped retrospectively based on their production performance at the ages of 12 and 24 months. In contrast to matched controls, infants with very low word production displayed event-related brain potentials with a significantly reduced amplitude of the discrimination response, i.e. a Mismatch Negativity (MMN), to the trochaic stress pattern. This amplitude difference indicates impaired prosodic processing of word stress during early development and may thus be taken as an early marker of risk for SLI.

Acoustic Stimulation↗

PubMed2005

Prosody-driven sentence processing: an event-related brain potential study.

Four experiments systematically investigating the brain's response to the perception of sentences containing differing amounts of linguistic information are presented. Spoken language generally provides various levels of information for the interpretation of the incoming speech stream. Here, we focus on the processing of prosodic phrasing, especially on its interplay with phonemic, semantic, and syntactic information. An event-related brain potential (ERP) paradigm was chosen to record the on-line responses to the processing of sentences containing major prosodic boundaries. For the perception of these prosodic boundaries, the so-called closure positive shift (CPS) has been manifested as a reliable and replicable ERP component. It has mainly been shown to correlate to major intonational phrasing in spoken language. However, to define this component as exclusively relying on the prosodic information in the speech stream, it is necessary to systematically reduce the linguistic content of the stimulus material. This was done by creating quasi-natural sentence material with decreasing semantic, syntactic, and phonemic information (i. e., jabberwocky sentences, in which all content words were replaced by meaningless words; pseudoword sentences, in which all function and all content words are replaced by meaningless words; and delexicalized sentences, hummed intonation contour of a sentence removing all segmental content). The finding that a CPS was identified in all sentence types in correlation to the perception of their major intonational boundaries clearly indicates that this effect is driven purely by prosody.

Acoustic Stimulation↗

PubMed2005

Native and nonnative speakers' processing of a miniature version of Japanese as revealed by ERPs.

Several event-related potential (ERP) studies in second language (L2) processing have revealed a differential vulnerability of syntax-related ERP effects in contrast to purely semantic ERP effects. However, it is still debated to what extent a potential critical period for L2 acquisition, as opposed to the attained proficiency level in the L2, contributes to the pattern of results reported in previous ERP studies. We studied L2 processing within the model of a miniature version of a natural language, namely Japanese, specifically constructed to assure high proficiency of the learners. In an auditory ERP experiment, we investigated sentence processing of the "Mini-Japanese" in Japanese native speakers and German volunteers before and after training. By making use of three different types of violation, namely, word category, case, and classifier violations, native and nonnative ERP patterns were compared. The three types of violation elicited three characteristic ERP patterns in Japanese native speakers. The word category violation elicited an anteriorly focused, broadly distributed early negativity followed by a P600, whereas the case violation evoked a P600 which was preceded by an N400. The classifier violation led solely to a late left distributed negativity with an anterior focus. Although the P600 was similar for Japanese natives and learners, the N400 and the anterior negativities were not present in the learner group. The differences across groups suggest deviant neural processes in on-line syntactic and thematic processing in the L2 learners despite high behavioral skills.

Acoustic Stimulation↗

PubMed2004

Music perception in cochlear implant users: an event-related potential study.

OBJECTIVE: Compare the processing of music-syntactic irregularities and physical oddballs between cochlear implant (CI) users and matched controls. METHODS: Musical chord sequences were presented, some of which contained functionally irregular chords, or a chord with an instrumental timbre that deviated from the standard timbre. RESULTS: In both controls and CI users, functionally irregular chords elicited early (around 200 ms) and late (around 500 ms) negative electric brain responses (early right anterior negativity,ERAN and N5). Amplitudes of effects depended on the degree of music-syntactic irregularity in both groups; effects elicited in CI users were distinctly smaller than in controls. Physically deviant chords elicited a timbre-mismatch negativity (MMN) and a P3 in both groups, again with smaller amplitudes in CI users. CONCLUSIONS: ERAN and N5 (as well as timbre-MMN and P3), can be elicited in CI users. Although amplitudes of effects were considerably smaller in the CI group, the presence of MMN and ERAN indicates that neural mechanisms of both physical and music-syntactic irregularity-detection were active in this group.

Acoustic Stimulation↗

PubMed2004

Discrimination of word stress in early infant perception: electrophysiological evidence.

Language acquisition crucially depends on the ability of the child to segment the incoming speech stream. Behavioral evidence supports the hypothesis that infants are sensitive to the rhythmic properties of the language input. We recorded event-related potentials (ERPs) to varying stress patterns of two syllable items in adults as well as in 4- and 5-month-old infants using a mismatch negativity (MMN) paradigm. Adult controls displayed a typical MMN to the trochaic item (stress on the first syllable) as well as to the iambic (stress on the second syllable) item. At the age of 4 months, no reliable discrimination response was seen. However, at the age of 5 months, a significant mismatch response (MMR) was observed for the trochaic item, indicating that the trochee, i.e. the most common stress pattern in German, was separated consistently from the iambic item. Hence, the present data demonstrate a clear development between 4 and 5 months with respect to the processing of different stress patterns relevant for word recognition. Moreover, possible contributions of different filter settings to the morphology of the mismatch response in infants are discussed.

Acoustic Stimulation↗

PubMed2004

Word category and verb--argument structure information in the dynamics of parsing.

One of the core issues in psycholinguistic research concerns the relationship between word category information and verb-argument structure (e.g. transitivity) information of verbs in the process of sentence parsing. In two experiments (visual versus auditory presentation) using event-related brain potentials (ERPs), we addressed this question by presenting sentences in which the critical word simultaneously realized both a word category and a transitivity violation. ERPs for sentences with both types of violation clustered with the patterns for sentences with a word category violation only, but were different from the patterns elicited by argument structure violations in isolation, since only the latter elicited an N400 ERP component. The finding that an argument structure violation evoked an N400 only if the phrase structure of the respective sentence was correct suggests that a successful integration of the word category information of a verb functionally precedes the application of its argument structure information.

Adult↗

PubMed2004

Brain signatures of syntactic and semantic processes during children's language development.

Developmental aspects of language comprehension were investigated using event-related brain potentials. Children between the ages of 6 and 13 listened to passive sentences that were correct, semantically incorrect, or syntactically incorrect, and data in each condition were compared with those of adults. For semantic violations, adults demonstrated a negativity (N400), as did children, but the latency decreased with age. For syntactic violations, adults displayed an early left anterior negativity (ELAN) and a late centro-parietal positivity (P600). A syntactic negativity and a late positivity were also present for children between 7 and 13 years, again with latency decreasing with age. Six-year-olds, in contrast, did not demonstrate an ELAN effect, but a late, reduced P600 pattern for the syntactic violation condition. In the early time window, the 6-year-olds displayed a widely distributed negativity that was larger for the correct than for the syntactically incorrect condition. These data indicate that the neurophysiological basis for semantic processes during auditory sentence comprehension does not change dramatically between early childhood and adulthood. Syntactic processes for passive sentences appear to differ between early and late childhood, at least with respect to those processes reflected in the ELAN component. As there is evidence that the ELAN reflects highly automatic structure-building processes, we conclude that these processes are not yet established at age 7, but gradually develop toward adult-like processing during late childhood.

Acoustic Stimulation↗

PubMed2003

Children processing music: electric brain responses reveal musical competence and gender differences.

Numerous studies investigated physiological correlates of the processing of musical information in adults. How these correlates develop during childhood is poorly understood. In the present study, we measured event-related electric brain potentials elicited in 5- and 9-year-old children while they listened to (major-minor tonal) music. Stimuli were chord sequences, infrequently containing harmonically inappropriate chords. Our results demonstrate that the degree of (in)appropriateness of the chords modified the brain responses in both groups according to music-theoretical principles. This suggests that already 5-year-old children process music according to a well-established cognitive representation of the major-minor tonal system and according to music-syntactic regularities. Moreover, we show that, in contrast to adults, an early negative brain response was left predominant in boys, whereas it was bilateral in girls, indicating a gender difference in children processing music, and revealing that children process music with a hemispheric weighting different from that of adults. Because children process, in contrast to adults, music in the same hemispheres as they process language, results indicate that children process music and language more similarly than adults. This finding might support the notion of a common origin of music and language in the human brain, and concurs with findings that demonstrate the importance of musical features of speech for the acquisition of language.

Acoustic Stimulation↗

PubMed2003

The brain generates its own sentence melody: a Gestalt phenomenon in speech perception.

Brain processes underlying spoken language comprehension comprise auditory encoding, prosodic analysis and linguistic evaluation. Auditory encoding usually activates both hemispheres while language-specific stages are lateralized: analysis of prosodic cues are right-lateralized while linguistic evaluation is left-lateralized. Here, we investigated to what extent the absence of prosodic information influences lateralization. MEG brain-responses indicated that syntactic violations lead to early bi-lateral brain responses for syntax violations. When the pitch of sentences was flattened to diminish prosodic cues, the brain's syntax response was lateralized to the right hemisphere, indicating that the missing pitch was generated automatically by the brain when it was absent. This represents a Gestalt phenomenon, since we perceive more than is actually presented.

Adult↗