Publications

Abstract

Tzeltal, a Mayan language spoken in southern Mexico, exhibits allo-morphy of an unusual type. The vowel quality of the perfective suffix is determined by the number of syllables in the stem to which it is attaching. This paper presents previously unpublished data of this allomorphy and demonstrates that a syllable-count analysis of the phenomenon is the proper one. This finding is put in a more general context of segment-prosody interaction in allomorphy.

Abstract

Readers and listeners actively predict upcoming words during language processing. These predictions might serve to support the unification of incoming words into sentence context and thus rely on interactions between areas in the language network. In the current magnetoencephalography study, participants read sentences that varied in contextual constraints so that the predictability of the sentence-final words was either high or low. Before the sentence-final words, we observed stronger alpha power suppression for the highly compared with low constraining sentences in the left inferior frontal cortex, left posterior temporal region, and visual word form area. Importantly, the temporal and visual word form area alpha power correlated negatively with left frontal gamma power for the highly constraining sentences. We suggest that the correlation between alpha power decrease in temporal language areas and left prefrontal gamma power reflects the initiation of an anticipatory unification process in the language network.

Abstract

Using magnetoencephalography, the current study examined gamma activity associated with language prediction. Participants read high- and low-constraining sentences in which the final word of the sentence was either expected or unexpected. Although no consistent gamma power difference induced by the sentence-final words was found between the expected and unexpected conditions, the correlation of gamma power during the prediction and activation intervals of the sentence-final words was larger when the presented words matched with the prediction compared with when the prediction was violated or when no prediction was available. This suggests that gamma magnitude relates to the match between predicted and perceived words. Moreover, the expected words induced activity with a slower gamma frequency compared with that induced by unexpected words. Overall, the current study establishes that prediction is related to gamma power correlations and a slowing of the gamma frequency.

Abstract

The blocked cyclic naming paradigm has been increasingly employed to investigate the mechanisms underlying spoken word production. Semantic homogeneity typically elicits longer naming latencies than heterogeneity; however, it is debated whether competitive lexical selection or incremental learning underlies this effect. The current study manipulated both semantic and phonological homogeneity and used behavioural and electrophysiological measurements to provide evidence that can distinguish between the two accounts. Results show that naming latencies are longer in semantically homogeneous blocks, but shorter in phonologically homogeneous blocks, relative to heterogeneity. The semantic factor significantly modulates electrophysiological waveforms from 200 ms and the phonological factor from 350 ms after picture presentation. A positive component was demonstrated in both manipulations, possibly reflecting a task-related top-down bias in performing blocked cyclic naming. These results provide novel insights into the neural correlates of blocked cyclic naming and further contribute to the understanding of spoken word production.

Abstract

Neurodevelopmental disorders have a strong genetic component, but despite widespread efforts, the specific genetic factors underlying these disorders remain undefined for a large proportion of affected individuals. Given the accessibility of exome-sequencing, this problem has thus far been addressed from a protein-centric standpoint; however, protein-coding regions only make up ∼1-2% of the human genome. With the advent of whole-genome sequencing we are in the midst of a paradigm shift as it is now possible to interrogate the entire sequence of the human genome (coding and non-coding) to fill in the missing heritability of complex disorders. These new technologies bring new challenges, as the number of non-coding variants identified per individual can be overwhelming, making it prudent to focus on non-coding regions of known function, for which the effects of variation can be predicted and directly tested to assess pathogenicity. The 3’UTRome is a region of the non-coding genome that perfectly fulfils these criteria and is of high interest when searching for pathogenic variation related to complex neurodevelopmental disorders. Herein, we review the regulatory roles of the 3’UTRome as binding sites for microRNAs, RNA binding proteins or during alternative polyadenylation. We detail existing evidence that these regions contribute to neurodevelopmental disorders and outline strategies for identification and validation of novel putatively pathogenic variation in these regions. This evidence suggests that studying the 3’UTRome will lead to the identification of new risk factors, new candidate disease genes and a better understanding of the molecular mechanisms contributing to NDDs.

Abstract

In processing connected speech, listeners must parse a highly variable signal. We investigate processing of a particular type of production variability, namely epenthetic stops between nasals and obstruents. Using a phoneme monitoring task and a dictation task, we test listeners' perception of epenthetic stops (which are not part of the string of segments intended by the speaker). We confirm that the epenthetic stop perceived is the one predicted by articulatory accounts of how such stops are produced, and that the likelihood of an epenthetic stop being perceived as a real stop is related to the strength of acoustic cues in the signal. We show that the probability of listeners mis-parsing epenthetic stops as real is influenced by language-specific syllable structure constraints, and depends on processing demands. We further show, through reaction time data, that even when epenthetic stops are perceived, they impose a greater processing load than stops which were intended by the speaker. These results show that processing of phonetic variability is affected by several factors, including language-specific phonology, even though the mis-timing of articulations that creates epenthetic stops is universally possible.

Abstract

In this paper, we use articulatory measures to determine whether Dutch schwa epenthesis is an abstract phonological process or a concrete phonetic process depending on articulatory timing. We examine tongue position during /l/ before underlying schwa and epenthetic schwa and in coda position. We find greater tip raising before both types of schwa, indicating light /l/ before schwa and dark /l/ in coda position. We argue that the ability of epenthetic schwa to condition the /l/ alternation shows that Dutch schwa epenthesis is an abstract phonological process involving insertion of some unit, and cannot be accounted for within Articulatory Phonology.

Abstract

Articulatory data are used to address the question of whether Dutch schwa insertion is a phonological or a phonetic process. By investigating tongue tip raising and dorsal lowering, we show that /l/ when it appears before inserted schwa is a light /l/, just as /l/ before an underlying schwa is, and unlike the dark /l/ before a consonant in non-insertion productions of the same words. The fact that inserted schwa can condition the light/dark /l/ alternation shows that schwa insertion involves the phonological insertion of a segment rather than phonetic adjustments to articulations.

Abstract

This study investigates whether the mora is used in controlling timing in Japanese speech, or is instead a structural unit in the language not involved in timing. Unlike most previous studies of mora-timing in Japanese, this article investigates timing in spontaneous speech. Predictability of word duration from number of moras is found to be much weaker than in careful speech. Furthermore, the number of moras predicts word duration only slightly better than number of segments. Syllable structure also has a significant effect on word duration. Finally, comparison of the predictability of whole words and arbitrarily truncated words shows better predictability for truncated words, which would not be possible if the truncated portion were compensating for remaining moras. The results support an accumulative model of variance with a final lengthening effect, and do not indicate the presence of any compensation related to mora-timing. It is suggested that the rhythm of Japanese derives from several factors about the structure of the language, not from durational compensation.

Abstract

The establishment of a reliable model for the study of Purkinje cells in vitro is of particular importance, given their central role in cerebellar function and pathology. Recent advances in induced pluripotent stem cell (iPSC) technology offer the opportunity to generate multiple neuronal subtypes for study in vitro. However, to date, only a handful of studies have generated Purkinje cells from human pluripotent stem cells, with most of these protocols proving challenging to reproduce. Here, we describe a simplified method for the reproducible generation of Purkinje cells from human iPSCs. After 21 days of treatment with factors selected to mimic the self-inductive properties of the isthmic organiser—insulin, fibroblast growth factor 2 (FGF2), and the transforming growth factor β (TGFβ)-receptor blocker SB431542—hiPSCs could be induced to form En1-positive cerebellar progenitors at efficiencies of up to 90%. By day 35 of differentiation, subpopulations of cells representative of the two cerebellar germinal zones, the rhombic lip (Atoh1-positive) and ventricular zone (Ptf1a-positive), could be identified, with the latter giving rise to cells positive for Purkinje cell progenitor-specific markers, including Lhx5, Kirrel2, Olig2 and Skor2. Further maturation was observed following dissociation and co-culture of these cerebellar progenitors with mouse cerebellar cells, with 10% of human cells staining positive for the Purkinje cell marker calbindin by day 70 of differentiation. This protocol, which incorporates modifications designed to enhance cell survival and maturation and improve the ease of handling, should serve to make existing models more accessible, in order to enable future advances in the field.

Abstract

Four phoneme-detection studies tested the conclusion from recent research that spoken-language processing is inhibited by violation of obligatory assimilation processes in the listeners’ native language. In Experiment 1, native listeners of German detected a target fricative in monosyllabic Dutch nonwords, half of which violated progressive German fricative place assimilation. In contrast to the earlier findings, listeners detected the fricative more quickly when assimilation was violated than when no violation occurred. This difference was not due to purely acoustic factors, since in Experiment 2 native Dutch listeners, presented with the same materials, showed no such effect. In Experiment 3, German listeners again detected the fricative more quickly when violation occurred in both monosyllabic and bisyllabic native nonwords, further ruling out explanations based on non-native input or on syllable structure. Finally Experiment 4 tested whether the direction in which the rule operates (progressive or regressive) controls the direction of the effect on phoneme detection responses.When regressive German place assimilation for nasals was violated, German listeners detected stops more slowly, exactly as had been observed in previous studies of regressive assimilation. It is argued that a combination of low expectations in progressive assimilation and novel popout causes facilitation of processing,whereas not fulfilling high expectations in regressive assimilation causes inhibition.

Abstract

Reports of an advantage of bilingualism on brain structure in young adult participants
are inconsistent. Abutalebi et al. (2012) reported more efficient monitoring of conflict during the
Flanker task in young bilinguals compared to young monolingual speakers. The present study
compared young adult (mean age = 24) Cantonese-English bilinguals in Hong Kong and young
adult monolingual speakers. We expected (a) differences in metabolites in neural tissue to result
from bilingual experience, as measured by 1H-MRS at 3T, (b) correlations between metabolic
levels and Flanker conflict and interference effects (c) different associations in bilingual and
monolingual speakers. We found evidence of metabolic differences in the ACC due to bilingualism,
specifically in metabolites Cho, Cr, Glx and NAA. However, we found no significant correlations
between metabolic levels and conflict and interference effects and no significant evidence of
differential relationships between bilingual and monolingual speakers. Furthermore, we found no
evidence of significant differences in the mean size of conflict and interference effects between
groups i.e. no bilingual advantage. Lower levels of Cho, Cr, Glx and NAA in bilingual adults
compared to monolingual adults suggest that the brains of bilinguals develop greater adaptive
control during conflict monitoring because of their extensive bilingual experience.

Abstract

How do languages express ideas of movement, and how do they package features that can be part of motion, such as path and cause? This questionnaire is used to gain a picture of the lexical resources a language draws on for motion expressions. It targets issues of semantic conflation (i.e., what other semantic information besides motion may be encoded in a verb root) and patterns of semantic distribution (i.e., what types of information are encoded in the morphemes that come together to build a description of a motion event). It was originally designed for Australian languages, but has since been used around the world.

Abstract

Contrastive reference, where a speaker presents or identifies one item in explicit contrast to another (I like this book but that one is boring), has special communicative and information structure properties. This can be reflected in rules of demonstrative use. For example, in some languages, terms equivalent to this and that can be used for contrastive reference in almost any spatial context. But other two-term languages stick more closely to “distance rules” for demonstratives, allowing a this-like term in close space only. This task elicits data concerning one context of contrastive reference, focusing on whether (and how) non-proximal demonstratives can be used to distinguish objects within a proximal area. The task runs like a memory game, with the consultant being asked to identify the locations of two or three hidden items arranged within arm’s reach.

Abstract

Demonstrative terms (e.g., this and that) are key to understanding how a language constructs and interprets spatial relationships. They are tricky to pin down, typically having functions that do not match “idealized” uses, and that can become invisible in narrow elicitation settings. This questionnaire is designed to identify the range(s) of use of certain spatial demonstrative terms, and help assess the roles played by gesture, access, attention, and addressee knowledge in demonstrative use. The stimuli consist of 25 diagrammed “elicitation settings” to be created by the researcher.

Abstract

Background

The biological mechanisms of headache chronification are poorly understood. We aimed to identify changes in DNA methylation associated with the transformation from episodic to chronic headache.
Methods

Participants were recruited from the population-based Norwegian HUNT Study. Thirty-six female headache patients who transformed from episodic to chronic headache between baseline and follow-up 11 years later were matched against 35 controls with episodic headache. DNA methylation was quantified at 485,000 CpG sites, and changes in methylation level at these sites were compared between cases and controls by linear regression analysis. Data were analyzed in two stages (Stages 1 and 2) and in a combined meta-analysis.
Results

None of the top 20 CpG sites identified in Stage 1 replicated in Stage 2 after multiple testing correction. In the combined meta-analysis the strongest associated CpG sites were related to SH2D5 and NPTX2, two brain-expressed genes involved in the regulation of synaptic plasticity. Functional enrichment analysis pointed to processes including calcium ion binding and estrogen receptor pathways.
Conclusion

In this first genome-wide study of DNA methylation in headache chronification several potentially implicated loci and processes were identified. The study exemplifies the use of prospectively collected population cohorts to search for epigenetic mechanisms of disease

Abstract

Researchers have suggested that the vocabularies of languages are oriented towards the communicative needs of language users. Here, we provide evidence demonstrating that the higher frequency of visual words in a large variety of English corpora is reflected in greater lexical differentiation—a greater number of unique words—for the visual domain in the English lexicon. In comparison, sensory modalities that are less frequently talked about, particularly taste and smell, show less lexical differentiation. In addition, we show that even though sensory language can be expected to change across historical time and between contexts of use (e.g., spoken language versus fiction), the pattern of visual dominance is a stable property of the English language. Thus, we show that across the board, precisely those semantic domains that are more frequently talked about are also more lexically differentiated, for perceptual experiences. This correlation between type and token frequencies suggests that the sensory lexicon of English is geared towards communicative efficiency.

Abstract

Angelika Wittek untersuchte Zustandsveränderungsverben bei vier- bis sechsjährigen Kindern. Englischsprechende Kinder verstehen bis zum Alter von 8 Jahren diese Verben als Bewegungsverben und ignorieren, daß sie zusätzlich die Information über einen Endzustand im Sinne der Negation des Ausgangszustands beeinhalten. Wittek zeigte, daß entgegen der Erwartung transparente, morphologisch komplexe Formen (wachmachen), in denen die Partikel den Endzustand explizit macht, nicht besser verstanden werden als Simplizia (wecken). Zudem diskutierte sie, inwieweit die Verwendung des Adverbs wieder in restitutiver Lesart Hinweise auf den Erwerb dieser Verben geben kann.

Abstract

Spinocerebellar ataxia type 14 (SCA14) is a subtype of the autosomal dominant cerebellar ataxias that is characterized by slowly progressive cerebellar dysfunction and neurodegeneration. SCA14 is caused by mutations in the PRKCG gene, encoding protein kinase C gamma (PKCγ). Despite the identification of 40 distinct disease-causing mutations in PRKCG, the pathological mechanisms underlying SCA14 remain poorly understood. Here we report the molecular neuropathology of SCA14 in post-mortem cerebellum and in human patient-derived induced pluripotent stem cells (iPSCs) carrying two distinct SCA14 mutations in the C1 domain of PKCγ, H36R and H101Q. We show that endogenous expression of these mutations results in the cytoplasmic mislocalization and aggregation of PKCγ in both patient iPSCs and cerebellum. PKCγ aggregates were not efficiently targeted for degradation. Moreover, mutant PKCγ was found to be hyper-activated, resulting in increased substrate phosphorylation. Together, our findings demonstrate that a combination of both, loss-of-function and gain-of-function mechanisms are likely to underlie the pathogenesis of SCA14, caused by mutations in the C1 domain of PKCγ. Importantly, SCA14 patient iPSCs were found to accurately recapitulate pathological features observed in post-mortem SCA14 cerebellum, underscoring their potential as relevant disease models and their promise as future drug discovery tools.

Abstract

Electroencephalography (EEG) provides high temporal resolution cognitive information from non-invasive recordings. However, one of the common practices-using a subset of sensors in ERP analysis is hard to provide a holistic and precise dynamic results. Selecting or grouping subsets of sensors may also be subject to selection bias, multiple comparison, and further complicated by individual differences in the group-level analysis. More importantly, changes in neural generators and variations in response magnitude from the same neural sources are difficult to separate, which limit the capacity of testing different aspects of cognitive hypotheses. We introduce EasyEEG, a toolbox that includes several multivariate analysis methods to directly test cognitive hypotheses based on topographic responses that include data from all sensors. These multivariate methods can investigate effects in the dimensions of response magnitude and topographic patterns separately using data in the sensor space, therefore enable assessing neural response dynamics. The concise workflow and the modular design provide user-friendly and programmer-friendly features. Users of all levels can benefit from the open-sourced, free EasyEEG to obtain a straightforward solution for efficient processing of EEG data and a complete pipeline from raw data to final results for publication.

Abstract

The three Olutec stories from Oluta, Veracruz, werenarrated by Antonio Asistente Maldonado. Roberto Zavala presents amorpheme-by-morpheme analysis of the texts with a sketch of the majorgrammatical and typological features of this language. Olutec is spoken bythree dozen speakers. The grammatical structure of this language has not beendescribed before. The sketch contains information on verb and noun morphology,verb dasses, clause types, inverse/direct patterns, grammaticalizationprocesses, applicatives, incorporation, word order type, and discontinuousexpressions. The stories presented here are the first Olutec texts everpublished. The motifs of the stories are well known throughout Middle America.The story of "the Rabbit who wants to be big" explains why one of the mainprotagonists of Middle American folktales acquired long ears. The story of "theDevil who is inebriated by the people of a village" explains how theinhabitants of a village discover the true identity of a man who likes to dancehuapango and decide to get rid of him. Finally the story of "theshit-sellers" presents two compadres, one who is lazy and the otherone who works hard. The hard-worker asks the lazy compadre how he surviveswithout working. The latter lies to to him that he sells shit in theneighboring village. The hard-working compadre decides to become a shit-sellerand in the process realizes that the lazy compadre deceived him. However, he islucky and meets with the Devil who offers him money in compensation for havingbeen deceived. When the lazy compadre realizes that the hard-working compadrehas become rich, he tries to do the same business but gets beaten in theprocess.

Abstract

Although bilingual speakers are very good at selectively using one language rather than another, sometimes language selection errors occur. To investigate how bilinguals monitor their speech errors and control their languages in use, we recorded event-related potentials (ERPs) in unbalanced Dutch-English bilingual speakers in a cued language-switching task. We tested the conflict-based monitoring model of Nozari and colleagues by investigating the error-related negativity (ERN) and comparing the effects of the two switching directions (i.e., to the first language, L1 vs. to the second language, L2). Results show that the speakers made more language selection errors when switching from their L2 to the L1 than vice versa. In the EEG, we observed a robust ERN effect following language selection errors compared to correct responses, reflecting monitoring of speech errors. Most interestingly, the ERN effect was enlarged when the speakers were switching to their L2 (less conflict) compared to switching to the L1 (more conflict). Our findings do not support the conflict-based monitoring model. We discuss an alternative account in terms of error prediction and reinforcement learning.

Abstract

Although bilingual speakers are very good at selectively using one language rather than another, sometimes language selection errors occur. We examined the relative contribution of top-down cognitive control and bottom-up language priming to these errors. Unbalanced Dutch-English bilinguals named pictures and were cued to switch between languages under time pressure. We also manipulated the number of same-language trials before a switch (long vs. short runs). Results show that speakers made more language selection errors when switching from their second language (L2) to the first language (L1) than vice versa. Furthermore, they made more errors when switching to the L1 after a short compared to a long run of L2 trials. In the reverse switching direction (L1 to L2), run length had no effect. These findings are most compatible with an account of language selection errors that assigns a strong role to top-down processes of cognitive control.

Abstract

It is undisputed that presenting a rhythmic stimulus leads to a measurable brain response that follows the rhythmic structure of this stimulus. What is still debated, however, is the question whether this brain response exclusively reflects a regular repetition of evoked responses, or whether it also includes entrained oscillatory activity. Here we systematically present evidence in favor of an involvement of entrained neural oscillations in the processing of rhythmic input while critically pointing out which questions still need to be addressed before this evidence could be considered conclusive. In this context, we also explicitly discuss the potential functional role of such entrained oscillations, suggesting that these stimulus-aligned oscillations reflect, and serve as, predictive processes, an idea often only implicitly assumed in the literature.