Do bilingual children lag behind? A study of morphological encoding using ERPs.

The current study investigates how bilingual children encode and produce morphologically complex words. We employed a silent-production-plus-delayed-vocalization paradigm in which event-related brain potentials (ERPs) were recorded during silent encoding of inflected words which were subsequently cued to be overtly produced. The bilingual children's spoken responses and their ERPs were compared to previous datasets from monolingual children on the same task. We found an enhanced negativity for regular relative to irregular forms during silent production in both bilingual children's languages, replicating the ERP effect previously obtained from monolingual children. Nevertheless, the bilingual children produced more morphological errors (viz. over-regularizations) than monolingual children. We conclude that mechanisms of morphological encoding (as measured by ERPs) are parallel for bilingual and monolingual children, and that the increased over-regularization rates are due to their reduced exposure to each of the two languages (relative to monolingual children).

Intermuscular technique for implantation of the subcutaneous implantable cardioverter defibrillator: long-term performance and complications.

AIMS: The subcutaneous cardioverter defibrillator was designed to overcome electrode complications of transvenous defibrillation systems. While largely achieved, pocket complications have increased. Subcutaneous implantation of the pulse generator leaves it prone to erosion, extrusion, discomfort, and poor cosmesis. METHODS AND RESULTS: We use a demonstration electrode and pulse generator with fluoroscopy, prior to prepping and draping, to maximize the left ventricular mass between them. We adapted a submuscular abdominal ICD technique to implant the S-ICD intermuscularly between the anterior surface of serratus anterior and the posterior surface of latissimus dorsi. Surgery in our patients beyond the subcutaneous tissue was bloodless, as muscle layers were carefully separated but not incised, which also protected the long thoracic nerve. Two layers of muscle protect the pulse generator. We have implanted 82 consecutive patients with this technique, taking ∼65 min. All patients were converted with 65 J standard polarity shock during induced arrhythmia conversion testing, with six (7.3%) patients requiring a repositioning of the pulse generator prior to successful conversion. Seven spontaneous episodes of ventricular fibrillation were detected in three (3.6%) patients, all successfully converted back to sinus rhythm. Long-term patient outcomes have been good with low complication rates over the mean ± standard deviation 3.6 ± 1.2 years. CONCLUSION: Our intermuscular technique and implant methodology is successful for placement of the subcutaneous defibrillator pulse generator. Our technique leads to an excellent cosmetic result and high levels of patient satisfaction. Rates of first shock conversion during defibrillation testing, inappropriate shocks, and complications during follow-up compare favourably with previous published case series. There were no left arm movement limitations post-operatively.

Morphological encoding in German children's language production: evidence from event-related brain potentials.

This study reports developmental changes in morphological encoding across late childhood. We examined event-related brain potentials (ERPs) during the silent production of regularly vs. irregularly inflected verb forms (viz. -t vs. -n participles of German) in groups of eight- to ten-year-olds, eleven- to thirteen-year-olds, and adults. The adult data revealed an enhanced (right-frontal) negativity 300-450 ms after cue onset for the (silent) production of -t relative to -n past participle forms (e.g. geplant vs. gehauen 'planned' vs. 'hit'). For the eleven- to thirteen-year-olds, the same enhanced negativity was found, with a more posterior distribution and a longer duration (=300-550 ms). The eight- to ten-year-olds also showed this negativity, again with a posterior distribution, but with a considerably delayed onset (800-1,000 ms). We suggest that this negativity reflects combinatorial processing required for producing -t participles in both children and adults and that the spatial and temporal modulations of this ERP effect across the three participant groups are due to developmental changes of the brain networks involved in processing morphologically complex words.

Morphological priming in child German.

Regular and irregular inflection in children's production has been examined in many previous studies. Yet, little is known about the processes involved in children's recognition of inflected words. To gain insight into how children process inflected words, the current study examines regular -t and irregular -n participles of German using the cross-modal priming technique testing 108 monolingual German-speaking children in two age groups (group I, mean age: 8;4, group II, mean age: 9;9) and a control group of 72 adults. Although both age groups of children had the same full priming effect as adults for -t forms, only children of age group II showed an adult-like (partial) priming effect for -n participles. We argue that children (within the age range tested) employ the same mechanisms for regular inflection as adults but that the lexical retrieval processes required for irregular forms become more efficient when children get older.

Linguistic markers of specific language impairment in bilingual children: the case of verb morphology.

This study investigates verbal morphology in Specific Language Impairment (SLI) in German, focusing on past participle inflection. Longitudinal data from 12 German-speaking children with SLI, six monolingual and six Turkish-German sequential bilingual children, were examined, plus an additional group of six typically developing Turkish-German sequential bilingual children. In a recent study (Rothweiler, M., Chilla, S., & H. Clahsen. (2012). Subject verb agreement in Specific Language Impairment: A study of monolingual and bilingual German-speaking children. Bilingualism: Language and Cognition, 15, 39-57), the same children with SLI were found to be severely impaired in reliably producing correct agreement-marked verb forms. By contrast, the new results reported in this study show that both the monolingual and the bilingual children with SLI produce participle inflection according to their language age. Our results strengthen the case of difficulties with agreement as a linguistic marker of SLI in German and show that it is possible to identify SLI from an early sequential bilingual child's performance in one of her two languages.

Improvement of tendon repair using muscle grafts transduced with TGF-ß1 cDNA.

Tendon rupture is a common injury. Inadequate endogenous repair often leaves patients symptomatic, with tendons susceptible to re-rupture. Administration of certain growth factors improves tendon healing in animal models, but their delivery remains a challenge. Here we evaluated the delivery of TGF-ß1 to tendon defects by the implantation of genetically modified muscle grafts. Rat muscle biopsies were transduced with recombinant adenovirus encoding TGF-ß1 and grafted onto surgically transected Achilles tendons in recipient animals. Tissue regenerates were compared to those of controls by biomechanical testing as well as histochemical and immunohistochemical analyses. Healing was greatly accelerated when genetically modified grafts were implanted into tendon defects, with the resulting repair tissue gaining nearly normal histological appearance as early as 2 weeks postoperatively. This was associated with decreased deposition of type III collagen in favour of large fibre bundles indicative of type I collagen. These differences in tendon composition coincided with accelerated restoration of mechanical strength. Tendon thickness increased in gene-treated animals at weeks 1 and 2, but by week 8 became significantly lower than that of controls suggesting accelerated remodelling. Thus localised TGF-ß1 delivery via adenovirus-modified muscle grafts improved tendon healing in this rat model and holds promise for clinical application.

The perfective past tense in Greek adolescents with Down syndrome.

This study investigates the ability of a group of eight Greek-speaking adolescents with Down Syndrome (DS) (aged 12.1-18.7) to handle the perfective past tense using an acceptability judgement task. The performance of the DS participants was compared with that of 16 typically-developing children whose chronological age was matched with the mental age of the DS group. For existing verbs, both groups showed high accuracy scores for the sigmatic past tense whilst for (potential but non-existing) nonce verbs the DS group performed differently from the controls. Specifically, their judgements were unaffected by a nonce verb's similarity to existing verbs, unlike those of the controls, suggesting that the DS participants were less reliant on similarity-based generalisations when encountering a nonce word than the controls. Apart from that, it was found that people with DS did not show any kind of morphological impairment, replicating previous findings on past tense production in DS.

Grammatical processing of spoken language in child and adult language learners.

This article presents a selective overview of studies that have investigated auditory language processing in children and late second-language (L2) learners using online methods such as event-related potentials (ERPs), eye-movement monitoring, or the cross-modal priming paradigm. Two grammatical phenomena are examined in detail, children's and adults' processing of German plural inflections (Lück et al. Brain Res 1077:144-152, 2006; Hahne et al. J Cognitive Neurosci 18:121-134, 2006; Clahsen et al. J Child Language 34:601-622, 2007) and language learners' processing of filler-gap dependencies in English (Felser C, Roberts L Second Language Res 23:9-36, 2007; Roberts et al. J Psycholinguist Res 36:175-188, 2007). The results from these studies reveal clear differences between native and nonnative processing in both domains of grammar, suggesting that nonnative listeners rely less on grammatical parsing routines during processing than either child or adult native listeners. We also argue that factors such as slower processing speed or cognitive resource limitations only provide a partial account of our findings.

Universal and particular in morphological processing: Evidence from Hebrew.

Do properties of individual languages shape the mechanisms by which they are processed? By virtue of their non-concatenative morphological structure, the recognition of complex words in Semitic languages has been argued to rely strongly on morphological information and on decomposition into root and pattern constituents. Here, we report results from a masked priming experiment in Hebrew in which we contrasted verb forms belonging to two morphological classes, Paal and Piel, which display similar properties, but crucially differ on whether they are extended to novel verbs. Verbs from the open-class Piel elicited familiar root priming effects, but verbs from the closed-class Paal did not. Our findings indicate that, similarly to other (e.g., Indo-European) languages, down-to-the-root decomposition in Hebrew does not apply to stems of non-productive verbal classes. We conclude that the Semitic word processor is less unique than previously thought: Although it operates on morphological units that are combined in a non-linear way, it engages the same universal mechanisms of storage and computation as those seen in other languages.

Morphological encoding beyond slots and fillers: An ERP study of comparative formation in English.

One important organizational property of morphology is competition. Different means of expression are in conflict with each other for encoding the same grammatical function. In the current study, we examined the nature of this control mechanism by testing the formation of comparative adjectives in English during language production. Event-related brain potentials (ERPs) were recorded during cued silent production, the first study of this kind for comparative adjective formation. We specifically examined the ERP correlates of producing synthetic relative to analytic comparatives, e.g. angrier vs. more angry. A frontal, bilaterally distributed, enhanced negative-going waveform for analytic comparatives (vis-a-vis synthetic ones) emerged approximately 300ms after the (silent) production cue. We argue that this ERP effect reflects a control mechanism that constrains grammatically-based computational processes (viz. more comparative formation). We also address the possibility that this particular ERP effect may belong to a family of previously observed negativities reflecting cognitive control monitoring, rather than morphological encoding processes per se.

How native-like is non-native language processing?

Following several decades of research on native language (L1) processing, psycholinguists have more recently begun to investigate how non-native language (L2) speakers comprehend and process language in real time. Regarding the traditional assumption that L2 learners have 'difficulty with grammar', this new research has revealed some unexpected similarities and differences between L1 and L2 processing. Specifically, it appears that L2 processing can become native-like in some linguistic subdomains (including certain aspects of grammar) but that L1 and L2 processing differences persist in the domain of complex syntax, even in highly proficient L2 speakers. Thus, more subtle linguistic distinctions seem to be required to understand the nature of non-native language processing.

The time-course of morphological constraints: evidence from eye-movements during reading.

Lexical compounds in English are constrained in that the non-head noun can be an irregular but not a regular plural (e.g. mice eater vs. *rats eater), a contrast that has been argued to derive from a morphological constraint on modifiers inside compounds. In addition, bare nouns are preferred over plural forms inside compounds (e.g. mouse eater vs. mice eater), a contrast that has been ascribed to the semantics of compounds. Measuring eye-movements during reading, this study examined how morphological and semantic information become available over time during the processing of a compound. We found that the morphological constraint affected both early and late eye-movement measures, whereas the semantic constraint for singular non-heads only affected late measures of processing. These results indicate that morphological information becomes available earlier than semantic information during the processing of compounds.

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.

Stem allomorphy in the Spanish mental lexicon: evidence from behavioral and ERP experiments.

This study presents results from a nonce-word elicited production task and a reading experiment using event-related brain potentials (ERPs) investigating finite forms of Spanish verbs which consist of marked stems and regular person and number agreement suffixes. The first experiment showed that unmarked stems are productively extended to nonce words, whereas marked stems generalize more restrictively to nonce words, based on lexical similarity to existing stem forms. The second experiment yielded a lexical ERP signature for stem violations and an ERP pattern signaling morpho-syntactic (rule-based) processing for suffix violations. We argue that stem allomorphy is lexically represented in the Spanish mental lexicon, with marked stems forming subnodes of structured lexical entries.

How Orthography Modulates Morphological Priming: Subliminal Kanji Activation in Japanese.

The current study investigates to what extent masked morphological priming is modulated by language-particular properties, specifically by its writing system. We present results from two masked priming experiments investigating the processing of complex Japanese words written in less common (moraic) scripts. In Experiment 1, participants performed lexical decisions on target verbs; these were preceded by primes which were either (i) a past-tense form of the same verb, (ii) a stem-related form with the epenthetic vowel -i, (iii) a semantically-related form, and (iv) a phonologically-related form. Significant priming effects were obtained for prime types (i), (ii), and (iii), but not for (iv). This pattern of results differs from previous findings on languages with alphabetic scripts, which found reliable masked priming effects for morphologically related prime/target pairs of type (i), but not for non-affixal and semantically-related primes of types (ii), and (iii). In Experiment 2, we measured priming effects for prime/target pairs which are neither morphologically, semantically, phonologically nor - as presented in their moraic scripts-orthographically related, but which-in their commonly written form-share the same kanji, which are logograms adopted from Chinese. The results showed a significant priming effect, with faster lexical-decision times for kanji-related prime/target pairs relative to unrelated ones. We conclude that affix-stripping is insufficient to account for masked morphological priming effects across languages, but that language-particular properties (in the case of Japanese, the writing system) affect the processing of (morphologically) complex words.

Finiteness and verb-second in German agrammatism.

This study presents results from sentence-completion and grammaticality-judgement tasks with seven German-speaking agrammatic aphasics and seven age-matched control subjects examining verb finiteness marking and verb-second (V2) placement. The patients were found to be selectively impaired in tense marking in the face of preserved mood and agreement marking. Moreover, our results revealed that V2 scores varied across our patients, with some showing impaired and others preserved V2 performance. These findings will be discussed in the light of different syntactic accounts of agrammatism.

Producing morphologically complex words: an ERP study with children and adults.

A widely studied morphological phenomenon in psycholinguistic research is the plurals-inside-compounds effect in English, which is the avoidance of regular plural modifiers within compounds (e.g., *rats hunter). The current study employs event-related brain potentials (ERPs) to investigate the production of plurals-inside-compounds in children and adults. We specifically examined the ERP correlates of producing morphologically complex words in 8-year-olds, 12-year-olds and adults, by recording ERPs during the silent production of compounds with plural or singular modifiers. Results for both children and adults revealed a negativity in response to compounds produced from regular plural forms when compared to compounds formed from irregular plurals, indicating a highly specific brain response to a subtle linguistic contrast. Although children performed behaviourally with an adult-like pattern in the task, we found a broader distribution and a considerably later latency in children's brain potentials than in adults', indicating that even in late childhood the brain networks involved in language processing are subject to subtle developmental changes.

Tense and agreement in German agrammatism.

This study presents results from sentence-completion and grammaticality-judgment tasks with 7 German-speaking agrammatic aphasics and 7 age-matched control subjects examining tense and subject-verb agreement marking. For both experimental tasks, we found that the aphasics achieved high correctness scores for agreement, while tense marking was severely impaired. To account for the observed tense-agreement dissociation, we suggest that the functional category T(ense)/INFL(ection) is tense-defective in agrammatic aphasia, i.e., it is specified for [+/-Realis], but not for [+/-Past]. It will also be argued that other accounts, specifically the tree-pruning model, do not explain our findings.

Storage and integration in the processing of filler-gap dependencies: an ERP study of topicalization and wh-movement in German.

We recorded event-related brain potentials (ERPs) during the processing of unambiguous German sentences containing different types of filler-gap dependency. Both topicalization constructions and wh-questions were found to elicit a left-anterior negativity (LAN) prior to the processing of the subcategorizing verb, relative to a gap-free control condition. At the subcategorizing verb, sentences containing a wh-dependency produced a parietal positivity (P600) relative to topicalization structures. These results support the claim that separable parsing processes are involved in the processing of syntactic dependencies, with working memory based processes being reflected in an LAN, and the relative difficulty of integrating the filler with its subcategorizer reflected in a P600. Integration cost but not memory cost was found to be influenced by the type of filler-gap dependency involved.

Brain potentials to inflected adjectives: beyond storage and decomposition.

This study uses event-related brain potentials (ERPs) to investigate the temporal sequencing of structural (grammatical) and lexical (semantic) properties of complex words during language comprehension. Morphologically complex words do not only consist of stems and affixes (e.g., 'feel'+'-s'), but affixes also contain grammatical structure, viz. feature bundles specifying their morpho-syntactic functions (e.g., -s= [3rd person, singular, present tense]). We examined inflected adjectives of German, which consist of an unaltered stem plus a portmanteau affix encoding case, number and gender. The same group of 24 adult native speakers was tested in two cross-modal ERP priming experiments separately studying effects of lexical-semantic relatedness and related affixes. The results of these experiments revealed clearly distinct brain potentials. Prime-target overlap with respect to morpho-syntactic features was associated with a reduced positivity, whereas lexical-level priming led to a reduced negativity. The former was most pronounced between 200 and 300 ms and the latter in a later time window, between 300 and 400 ms. We interpret the reduced early positivity as reflecting ease of grammatical processing effort in case of primed (relative to unprimed) morpho-syntactic features and the reduced negativity as signaling facilitation in lexical retrieval for primed (compared to unprimed) words. Our ERP results indicate that grammatical information becomes available earlier than semantic information providing support for structure-first models of language processing.