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1.
Artigo em Inglês | MEDLINE | ID: mdl-38703197

RESUMO

PURPOSE: Perceived social support has been shown to positively correlate with health-related quality of life (HR-QoL) in a variety of conditions. This study investigated whether perceived social support is affecting HR-QoL of patients who receive a cochlear implant (CI) for deafness. METHODS: Eighty eight adults (56 males, 32 females; mean age: 60 years) with a uni- or bilateral CI for bilateral high-grade hearing loss were administered two questionnaires: a questionnaire for perceived social support (FSU-14) and the Nijmegen Cochlear Implant Questionnaire (NCIQ) for hearing-specific HR-QoL. Administration of the questionnaires occurred at four points in time: before implantation and three, 12 and 24 months after implant activation. RESULTS: The CI patients had quite high levels of perceived social support (mean percentile rank: 71), which remained stable at all four measurement points. Multivariate Analysis showed a significant interaction between perceived social support and HR-QoL indicating that higher perceived social support lead to higher improvement of HR-QoL after cochlear implantation. CONCLUSION: The CI patients in this study had higher than average levels of perceived social support, which did not change before and after cochlear implantation. Perceived social support and HR-QoL were related such that patients with high levels of perceived social support experienced greater improvement of their HR-QoL after cochlear implantation than patients with low levels of perceived social support. Based on this finding, perceived social support must be considered as an important factor for HR-QoL after cochlear implantation.

2.
Eur J Neurol ; 31(5): e16224, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38308469

RESUMO

BACKGROUND AND PURPOSE: Dysphagia is associated with poor outcome, higher mortality, reduced quality of life, and social isolation. We investigate the relationship between swallowing impairment and symptoms of anxiety and depression after ischemic stroke. METHODS: Consecutive patients with ischemic stroke participating in the prospective STROKE-CARD Registry study from 2020 to 2022 were assessed for dysphagia on hospital admission (clinical swallowing assessment) and for persistence until discharge and 3-month follow-up (SINGER Independency Index). Anxiety and depression symptoms were recorded using Beck Depression Inventory (BDI) and Hospital Anxiety and Depression Scale (HADS) at 3-month follow-up. RESULTS: Of 648 patients, 19.3% had dysphagia on admission, persisting in 14.8% at discharge and 6.8% at 3-month follow-up. With the presence or duration of dysphagia (no dysphagia, dysphagia at baseline, at discharge, at 3 months), score (mean ± SD) increased on the BDI (7.9 ± 6.7, 12.5 ± 8.7, 13.5 ± 9.0, 16.5 ± 10.2), HADS-D (4.4 ± 3.7, 7.1 ± 4.2, 7.7 ± 4.4, 9.8 ± 4.3), and HADS-A (4.4 ± 3.5, 5.4 ± 3.6, 6.0 ± 3.6, 7.0 ± 3.6). In linear regression analysis adjusting for age, sex, diabetes, dementia, and either functional disability or stroke severity, BDI and HADS-D scores were significantly higher in patients with dysphagia across all points in time (admission, discharge, 3-month follow-up). An independent association with HADS-A scores was only evident in patients with persisting dysphagia after 3 months. Patients with dysphagia were more likely to receive antidepressants, antipsychotics, or benzodiazepines at discharge and 3-month follow-up. CONCLUSIONS: Dysphagia after stroke is common and severely affects psychosocial functioning of individuals. Our results highlight swallowing impairment as an independent predictor for poststroke depressive and, to a lesser extent, anxiety symptoms.


Assuntos
Transtornos de Deglutição , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Depressão/etiologia , Depressão/psicologia , AVC Isquêmico/complicações , Transtornos de Deglutição/etiologia , Qualidade de Vida , Ansiedade/etiologia , Ansiedade/psicologia , Acidente Vascular Cerebral/diagnóstico
3.
Otol Neurotol ; 45(3): e228-e233, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38238908

RESUMO

BACKGROUND AND OBJECTIVES: The ability to localize sounds is partly recovered in patients using a cochlear implant (CI) in one ear and a hearing aid (HA) on the contralateral side. Binaural processing seems effective at least to some extent, despite the difference between electric and acoustic stimulation in each ear. To obtain further insights into the mechanisms of binaural hearing in these listeners, localization of low- and high-frequency sounds was tested. STUDY DESIGN: The study used a within-subject design, where participants were tasked with localizing sound sources in the horizontal plane. The experiment was conducted in an anechoic chamber, where an array of seven loudspeakers was mounted along the 24 azimuthal angle span from -90° to +90°. Stimuli were applied with different frequencies: broadband noise and high- and low-frequency noise. SUBJECTS: Ten CI recipients participated in the study. All had an asymmetric hearing loss with a CI in the poorer ear and an HA on the contralateral side. MAIN OUTCOME MEASURES: Accuracy of sound localization in terms of angular error and percentage of correct localization scores. RESULTS: The median angular error was 40° in bimodal conditions for both broadband noise and high-frequency noise stimuli. The angular error increased to 47° for low-frequency noise stimuli. In the unilaterally aided condition with an HA, only a median angular error of 78° was observed. CONCLUSIONS: Irrespective of the frequency composition of the stimuli, this group of bimodal listeners showed some ability to localize sounds. Angular errors were larger than those reported in the literature for bilateral CI users or single-sided deaf listeners with a CI. In the unilateral listening condition with HA, only localization of sounds was not possible for most subjects.


Assuntos
Implante Coclear , Implantes Cocleares , Auxiliares de Audição , Localização de Som , Percepção da Fala , Humanos , Audição
4.
Brain Sci ; 11(5)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33925958

RESUMO

Impaired cognitive control plays a crucial role in anxiety disorders and is associated with deficient neural mechanisms in the fronto-parietal network. Usually, these deficits were found in tasks with an emotional context. The present study aimed at investigating electrophysiological and vascular signatures from event-related brain potentials (ERPs) and functional near-infrared spectroscopy (fNIRS) in anxiety patients versus healthy controls during an inhibition task integrated in an emotionally neutral context. Neural markers were acquired during the completion of a classical Eriksen flanker task. The focus of data analysis has been the ERPs N200 and P300 and fNIRS activations in addition to task performance. No behavioral or neural group differences were identified. ERP findings showed a larger N2pc and a delayed and reduced P300 for incongruent stimuli. The N2pc modulation suggests the reorienting of attention to salient stimuli, while the P300 indicates longer lasting stimulus evaluation processes due to increased task difficulty. FNIRS did not result in any significant activation potentially suggesting a contribution from deeper brain areas not measurable with fNIRS. The missing group difference in our non-emotional task indicates that no generalized cognitive control deficit but rather a more emotionally driven deficit is present in anxiety patients.

5.
PLoS One ; 16(2): e0246421, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33606715

RESUMO

Being proficient in several foreign languages is an essential part of every-day life. In contrast to childhood, learning a new language can be highly challenging for adults. The present study aims at investigating neural mechanisms supporting very initial foreign language learning in adulthood. For this reason, subjects underwent an implicit semantic associative training in which they had to learn new pseudoword-picture pairings. Learning success was measured via a recognition experiment presenting learned versus new pseudoword-picture pairings. Neural correlates were assessed by an innovative multi-methodological approach simultaneously applying electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). Results indicate memory-related processes based on familiarity and mechanisms of cognitive control to be present during initial vocabulary learning. Findings underline the fascinating plasticity of the adult brain during foreign language learning, even after a short semantic training of only 18 minutes as well as the importance of comparing evidence from different neuroscientific methods and behavioral data.


Assuntos
Idioma , Aprendizagem , Reconhecimento Visual de Modelos , Adulto , Fatores Etários , Mapeamento Encefálico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Brain Sci ; 10(12)2020 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-33291489

RESUMO

Studies in adults showed differential neural processing between overt and inner speech. So far, it is unclear whether inner and overt speech are processed differentially in children. The present study examines the pre-activation of the speech network in order to disentangle domain-general executive control from linguistic control of inner and overt speech production in 6- to 7-year-olds by simultaneously applying electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). Children underwent a picture-naming task in which the pure preparation of a subsequent speech production and the actual execution of speech can be differentiated. The preparation phase does not represent speech per se but it resembles the setting up of the language production network. Only the fNIRS revealed a larger activation for overt, compared to inner, speech over bilateral prefrontal to parietal regions during the preparation phase. Findings suggest that the children's brain can prepare the subsequent speech production. The preparation for overt and inner speech requires different domain-general executive control. In contrast to adults, the children´s brain did not show differences between inner and overt speech when a concrete linguistic content occurs and a concrete execution is required. This might indicate that domain-specific executive control processes are still under development.

7.
Sci Rep ; 10(1): 17976, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087750

RESUMO

Similar to sleeping after learning, a brief period of wakeful resting after encoding new information supports memory retention in contrast to task-related cognition. Recent evidence suggests that working memory capacity (WMC) is related to sleep-dependent declarative memory consolidation. We tested whether WMC moderates the effect of a brief period of wakeful resting compared to performing a distractor task subsequent to encoding a word list. Participants encoded and immediately recalled a word list followed by either an 8 min wakeful resting period (eyes closed, relaxed) or by performing an adapted version of the d2 test of attention for 8 min. At the end of the experimental session (after 12-24 min) and again, after 7 days, participants were required to complete a surprise free recall test of both word lists. Our results show that interindividual differences in WMC are a central moderating factor for the effect of post-learning activity on memory retention. The difference in word retention between a brief period of wakeful resting versus performing a selective attention task subsequent to encoding increased in higher WMC individuals over a retention interval of 12-24 min, as well as over 7 days. This effect was reversed in lower WMC individuals. Our results extend findings showing that WMC seems not only to moderate sleep-related but also wakeful resting-related memory consolidation.


Assuntos
Aprendizagem/fisiologia , Consolidação da Memória/fisiologia , Memória de Curto Prazo/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Descanso/fisiologia , Fatores de Tempo , Vigília/fisiologia , Testes de Associação de Palavras , Adulto Jovem
8.
Dev Cogn Neurosci ; 43: 100784, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32510350

RESUMO

The present study investigated neural correlates of implicit phonotactic processing in 18-month-old children that just reached an important step in language development: the vocabulary spurt. Pseudowords, either phonotactically legal or illegal with respect to their native language, were acoustically presented to monolingually German raised infants. Neural activity was simultaneously assessed by means of electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). The former method excellently tracks fast processing mechanisms, whereas the latter reveals brain areas recruited. Results of the present study indicate that 18-month-olds recognize the linguistic properties of their native language based on phonotactics. This manifested in an increased N400 for legal compared to illegal pseudowords in the EEG conforming to adult-like mechanisms. Unfortunately, fNIRS findings did not support this discrimination ability. Possible methodological and brain maturational reasons might explain this null finding. This study provides evidence for the advantage of a multi-methodological approach in order to get a clear picture on neural language development.


Assuntos
Eletroencefalografia/métodos , Desenvolvimento da Linguagem , Feminino , Humanos , Lactente , Masculino
9.
Sci Rep ; 10(1): 5807, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242032

RESUMO

The capability of differentiating between various emotional states in speech displays a crucial prerequisite for successful social interactions. The aim of the present study was to investigate neural processes underlying this differentiating ability by applying a simultaneous neuroscientific approach in order to gain both electrophysiological (via electroencephalography, EEG) and vascular (via functional near-infrared-spectroscopy, fNIRS) responses. Pseudowords conforming to angry, happy, and neutral prosody were presented acoustically to participants using a passive listening paradigm in order to capture implicit mechanisms of emotional prosody processing. Event-related brain potentials (ERPs) revealed a larger P200 and an increased late positive potential (LPP) for happy prosody as well as larger negativities for angry and neutral prosody compared to happy prosody around 500 ms. FNIRS results showed increased activations for angry prosody at right fronto-temporal areas. Correlation between negativity in the EEG and activation in fNIRS for angry prosody suggests analogous underlying processes resembling a negativity bias. Overall, results indicate that mechanisms of emotional and phonological encoding (P200), emotional evaluation (increased negativities) as well as emotional arousal and relevance (LPP) are present during implicit processing of emotional prosody.


Assuntos
Circulação Cerebrovascular , Emoções , Potenciais Evocados , Fonação , Percepção da Fala , Adulto , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espectroscopia de Luz Próxima ao Infravermelho
10.
Brain Sci ; 10(3)2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32143405

RESUMO

Speech production not only relies on spoken (overt speech) but also on silent output (inner speech). Little is known about whether inner and overt speech are processed differently and which neural mechanisms are involved. By simultaneously applying electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS), we tried to disentangle executive control from motor and linguistic processes. A preparation phase was introduced additionally to the examination of overt and inner speech directly during naming (i.e., speech execution). Participants completed a picture-naming paradigm in which the pure preparation phase of a subsequent speech production and the actual speech execution phase could be differentiated. fNIRS results revealed a larger activation for overt rather than inner speech at bilateral prefrontal to parietal regions during the preparation and at bilateral temporal regions during the execution phase. EEG results showed a larger negativity for inner compared to overt speech between 200 and 500 ms during the preparation phase and between 300 and 500 ms during the execution phase. Findings of the preparation phase indicated that differences between inner and overt speech are not exclusively driven by specific linguistic and motor processes but also impacted by inhibitory mechanisms. Results of the execution phase suggest that inhibitory processes operate during phonological code retrieval and encoding.

11.
Brain Sci ; 10(1)2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31936356

RESUMO

The present study investigates whether meaning is similarly extracted from spoken and sung sentences. For this purpose, subjects listened to semantically correct and incorrect sentences while performing a correctness judgement task. In order to examine underlying neural mechanisms, a multi-methodological approach was chosen combining two neuroscientific methods with behavioral data. In particular, fast dynamic changes reflected in the semantically associated N400 component of the electroencephalography (EEG) were simultaneously assessed with the topographically more fine-grained vascular signals acquired by the functional near-infrared spectroscopy (fNIRS). EEG results revealed a larger N400 for incorrect compared to correct sentences in both spoken and sung sentences. However, the N400 was delayed for sung sentences, potentially due to the longer sentence duration. fNIRS results revealed larger activations for spoken compared to sung sentences irrespective of semantic correctness at predominantly left-hemispheric areas, potentially suggesting a greater familiarity with spoken material. Furthermore, the fNIRS revealed a widespread activation for correct compared to incorrect sentences irrespective of modality, potentially indicating a successful processing of sentence meaning. The combined results indicate similar semantic processing in speech and song.

12.
Brain Sci ; 9(8)2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31430984

RESUMO

Anxiety disorders are the most common psychological disorders worldwide resulting in a great demand of adequate and cost-effective treatment. New short-term interventions can be used as an effective adjunct or alternative to pharmaco- and psychotherapy. One of these approaches is therapeutic tapping. It combines somatic stimulation of acupressure points with elements from Cognitive Behavioral Therapy (CBT). Tapping reduces anxiety symptoms after only one session. Anxiety is associated with a deficient emotion regulation for threatening stimuli. These deficits are compensated e.g., by CBT. Whether Tapping can also elicit similar modulations and which dynamic neural correlates are affected was subject to this study. Anxiety patients were assessed listening to pseudowords with a different emotional prosody (happy, angry, fearful, and neutral) prior and after one Tapping session. The emotion-related component Late Positive Potential (LPP) was investigated via electroencephalography. Progressive Muscle Relaxation (PMR) served as control intervention. Results showed LPP reductions for negative stimuli after the interventions. Interestingly, PMR influenced fearful and Tapping altered angry prosody. While PMR generally reduced arousal for fearful prosody, Tapping specifically affected fear-eliciting, angry stimuli, and might thus be able to reduce anxiety symptoms. Findings highlight the efficacy of Tapping and its impact on neural correlates of emotion regulation.

13.
Brain Sci ; 9(2)2019 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-30759804

RESUMO

Studies of novel noun learning show bilingual children rely less on the Mutual Exclusivity Constraint (MEC) for word learning than monolinguals. Shifting the focus to learning novel property terms (adjectives), the present study compared 3.5- and five-year-old bilingual and monolingual preschoolers' adherence to the MEC. We found no bilingual-monolingual differences on a behavioral forced-choice task for the 3.5-year-olds, but five-year-old monolinguals adhered more to the MEC than bilinguals did. Older bilinguals adhered less to the MEC than younger ones, while there was no difference in MEC adherence between the younger and older monolinguals. In the 5-year-olds, we additionally acquired neurophysiological data using functional near-infrared spectroscopy (fNIRS) to allow for a first explorative look at potential neuronal underpinnings. The data show that, compared to bilinguals, monolinguals reveal higher activation over three brain regions (right frontal, left temporo-parietal, and left prefrontal) that may be involved in exploiting the MEC, building on conflict detection, inhibition, solution of a disjunction, and working memory processes. Taken together, our behavioral and neurophysiological findings reveal different paths towards novel property term learning depending on children's language acquisition context.

14.
Front Psychiatry ; 9: 62, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29556204

RESUMO

BACKGROUND: 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). METHODS: 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. RESULTS: 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. CONCLUSION: 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.

15.
Front Psychol ; 8: 595, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28473786

RESUMO

Two experiments aimed at investigating how working memory capacity (WMC) related to processing wh-extractions in both a grammatical judgment and a translation task by using the Operation Span task. A self-paced paradigm was used to collect response times and accuracy rates. In Experiment 1, results showed that high WMC was related to faster grammatical judgment of the critical region in subject- and object-extractions. In Experiment 2, high WMC was only related to high accuracy in translating wh-extractions. These results indicate that individual differences in WMC play a certain role during L2 sentence processing, and experimental tasks can modulate this effect.

16.
Dev Cogn Neurosci ; 25: 185-197, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27692617

RESUMO

During early language development native phonotactics are acquired in a 'bottom-up' fashion, relying on exquisite auditory differentiation skills operational from birth. Since basic lexico-semantic abilities have been demonstrated from 6 months onwards, 'top-down' influences on phonotactic learning may complement the extraction of transitional probabilities in phonotactic learning. Such a bidirectional acquisition strategy predicts, that familiarization with (proto)words should affect processing of untrained word-forms of similar phonological structure. We investigated 6-month-old infants undergoing an associative training to establish a pseudoword-pseudoobject link. Comparison between pre- and post-training responses to trained and untrained items allowed investigating training effects. Additionally phonotactic status (50% legal, 50% illegal with regard to German) allowed investigating influences of previous language experience. EEG and functional near-infrared spectroscopy (fNIRS) provided measures of electrophysiological and hemodynamic responses. We find evidence for a robust effect of associative training on pseudoword processing when presented in isolation. This transferred to untrained items. Previous linguistic experience showed a much weaker effect. Taken together the results suggest that sensitivity to phonotactic contrasts is present at 6 months, but that acceptance as lexical candidates is rapidly modulated when word forms following non-native phonotactics become potentially meaningful due to repeated exposure in a semantic context.


Assuntos
Eletroencefalografia/métodos , Desenvolvimento da Linguagem , Fonética , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Feminino , Humanos , Lactente , Aprendizagem , Masculino
17.
BMC Psychiatry ; 16: 219, 2016 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-27389007

RESUMO

BACKGROUND: Hippocampal/parahippocampal structural changes accompany major depressive disorders in the elderly, but whether subthreshold depression (StD) at an advanced age is also accompanied by similar changes in hippocampal/parahippocampal volumes is still unknown. By using voxel-based morphometry (VBM) analysis of the gray matter, we explored whether there are structural alterations of the hippocampus/parahippocampus and the correlations between its volume and participants' self-reported depressive symptoms. METHODS: Participants were 19 community-dwelling older adults with StD assessed by the Center for Epidemiologic Studies Depression scale (CES-D) scores. We collected magnetic resonance images of their brain compared to images of 17 healthy aged-matched adults. We used VBM to analyze differences in gray matter volume (GMV) of the hippocampus/parahippocampus between the two groups. Moreover, we examined the correlation between the GMV of the hippocampus/parahippocampus and participants' self-reported depressive symptoms. RESULTS: VBM revealed that elderly individuals with StD had substantially reduced volumes of the right parahippocampus compared to healthy controls. Furthermore, the volumes of the hippocampus/parahippocampus were significantly associated with participants' self-reported depressive symptoms in StD. CONCLUSIONS: Gray matter volume alterations in the hippocampus/parahippocampus are correlated with subthreshold depression suggesting that early structural changes in the hippocampus/parahippocampus can constitute a risk indicator of depression.


Assuntos
Depressão/patologia , Substância Cinzenta/patologia , Hipocampo/patologia , Giro Para-Hipocampal/patologia , Idoso , Atrofia/patologia , Estudos de Casos e Controles , Estudos Transversais , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Neuroimagem , Sintomas Prodrômicos , Fatores de Risco
18.
Brain ; 139(Pt 6): 1800-16, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27190021

RESUMO

SEE CAPPA DOI101093/BRAIN/AWW090 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE : The phonological structure of speech supports the highly automatic mapping of sound to meaning. While it is uncontroversial that phonotactic knowledge acts upon lexical access, it is unclear at what stage these combinatorial rules, governing phonological well-formedness in a given language, shape speech comprehension. Moreover few studies have investigated the neuronal network affording this important step in speech comprehension. Therefore we asked 70 participants-half of whom suffered from a chronic left hemispheric lesion-to listen to 252 different monosyllabic pseudowords. The material models universal preferences of phonotactic well-formedness by including naturally spoken pseudowords and digitally reversed exemplars. The latter partially violate phonological structure of all human speech and are rich in universally dispreferred phoneme sequences while preserving basic auditory parameters. Language-specific constraints were modelled in that half of the naturally spoken pseudowords complied with the phonotactics of the native language of the monolingual participants (German) while the other half did not. To ensure universal well-formedness and naturalness, the latter stimuli comply with Slovak phonotactics and all stimuli were produced by an early bilingual speaker. To maximally attenuate lexico-semantic influences, transparent pseudowords were avoided and participants had to detect immediate repetitions, a task orthogonal to the contrasts of interest. The results show that phonological 'well-formedness' modulates implicit processing of speech at different levels: universally dispreferred phonological structure elicits early, medium and late latency differences in the evoked potential. On the contrary, the language-specific phonotactic contrast selectively modulates a medium latency component of the event-related potentials around 400 ms. Using a novel event-related potential-lesion approach allowed us to furthermore supply first evidence that implicit processing of these different phonotactic levels relies on partially separable brain areas in the left hemisphere: contrasting forward to reversed speech the approach delineated an area comprising supramarginal and angular gyri. Conversely, the contrast between legal versus illegal phonotactics consistently projected to anterior and middle portions of the middle temporal and superior temporal gyri. Our data support the notion that phonological structure acts on different stages of phonologically and lexically driven steps of speech comprehension. In the context of previous work we propose context-dependent sensitivity to different levels of phonotactic well-formedness.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiologia , Dominância Cerebral , Eletroencefalografia , Idioma , Psicoacústica , Percepção da Fala/fisiologia , Estimulação Acústica , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Estudos de Casos e Controles , Sinais (Psicologia) , Potenciais Evocados Auditivos/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
PLoS One ; 9(10): e110887, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25343253

RESUMO

This paper presents an experiment that explored the role of domain-general inhibitory control on language switching. Reaction times (RTs) and event-related brain potentials (ERPs) were recorded when low-proficient bilinguals with high and low inhibitory control (IC) switched between overt picture naming in both their L1 and L2. Results showed that the language switch costs of bilinguals with high-IC were symmetrical, while that of bilinguals with low-IC were not. The N2 component failed to show a significant interaction between group, language and task, indicating that inhibition may not comes into play during the language task schema competition phase. The late positive component (LPC), however, showed larger amplitudes for L2 repeat and switch trials than for L1 trials in the high-IC group, indicating that inhibition may play a key role during the lexical response selection phase. These findings suggest that domain-general inhibitory control plays an important role in modulating language switch costs and its influence can be specified in lexical selection phase.


Assuntos
Potenciais Evocados/fisiologia , Idioma , Multilinguismo , Inibição Neural/fisiologia , Adolescente , Comportamento , Eletroencefalografia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Adulto Jovem
20.
Brain Lang ; 127(3): 404-14, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23489581

RESUMO

In two experiments we investigate how repeated exposure to native and non-native phonotactic regularities alters the N400, an event-related potential related to lexico-semantic access. Participants underwent a Passive Listening (Experiment 1) or a Categorization Training (Experiment 2) for monosyllabic pseudowords over 3 days. During Passive Listening participants solely listened to the stimuli while for Categorization Training they learned to assign items to two arbitrary categories by feedback. Notably, this task did not rely on phonotactic regularities. Before training, N400 was larger for legal compared to illegal items. Over the 3-day exposure Passive Listening yielded a significant decrease in N400-amplitude for illegal pseudowords, however, this effect was abolished and partially inverted by the Categorization Training. We suggest the decrease in N400-amplitude indicates more efficient discrimination between native and non-native pseudowords since only the former are potential lexical candidates. On the contrary, Categorization Training introduces a 'protosemantic' context overriding prelexical selection processes.


Assuntos
Percepção Auditiva/fisiologia , Encéfalo/fisiologia , Potenciais Evocados/fisiologia , Fonética , Adolescente , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Semântica , Adulto Jovem
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