Publications

Abstract

We used ERPs to investigate the pre-activation of form and meaning in language comprehension. Participants read high-cloze sentence contexts (e.g., “The student is going to the library to borrow a…”), followed by a word that was predictable (book), form-related (hook) or semantically related (page) to the predictable word, or unrelated (sofa). At a 500 ms SOA (Experiment 1), semantically related words, but not form-related words, elicited a reduced N400 compared to unrelated words. At a 700 ms SOA (Experiment 2), semantically related words and form-related words elicited reduced N400 effects, but the effect for form-related words occurred in very high-cloze sentences only. At both SOAs, form-related words elicited an enhanced, post-N400 posterior positivity (Late Positive Component effect). The N400 effects suggest that readers can pre-activate meaning and form information for highly predictable words, but form pre-activation is more limited than meaning pre-activation. The post-N400 LPC effect suggests that participants detected the form similarity between expected and encountered input. Pre-activation of word forms crucially depends upon the time that readers have to make predictions, in line with production-based accounts of linguistic prediction.

Abstract

Coevolving systems are notoriously difficult to understand. This is largely due to the Red Queen effect that dictates heterospecific fitness interdependence. In simulation studies of coevolving systems, master tournaments are often used to obtain more informed fitness measures by testing evolved individuals against past and future opponents. However, such tournaments still contain certain ambiguities. We introduce the use of a phenotypic cluster analysis to examine the distribution of opponent categories throughout an evolutionary sequence. This analysis, adopted from widespread usage in the bioinformatics community, can be applied to master tournament data. This allows us to construct behavior-based category trees, obtaining a hierarchical classification of phenotypes that are suspected to interleave during cyclic evolution. We use the cluster data to establish the existence of switching-genes that control opponent specialization, suggesting the retention of dormant genetic adaptations, that is, genetic memory. Our overarching goal is to reiterate how computer simulations may have importance to the broader understanding of evolutionary dynamics in general. We emphasize a further shift from a component-driven to an interaction-driven perspective in understanding coevolving systems. As yet, it is unclear how the sudden development of switching-genes relates to the gradual emergence of genetic adaptability. Likely, context genes gradually provide the appropriate genetic environment wherein the switching-gene effect can be exploited

Abstract

The authors report six implicit priming experiments that examined the production of inflected forms. Participants produced words out of small sets in response to prompts. The words differed in form or shared word-initial segments, which allowed for preparation. In constant inflectional sets, the words had the same number of inflectional suffixes, whereas in variable sets the number of suffixes differed. In the experiments, preparation effects were obtained, which were larger in the constant than in the variable sets. Control experiments showed that this difference in effect was not due to syntactic class or phonological form per se. The results are interpreted in terms of a slot-and-filler model of word production, in which inflectional frames, on the one hand, and stems and affixes, on the other hand, are independently spelled out on the basis of an abstract morpho-syntactic specification of the word, which is followed by morpheme-to-frame association.

Abstract

In Iterated Learning (IL) experiments, a participant’s learned output serves as the next participant’s learning input (Kirby et al., 2014). IL can be used to model cultural transmission and has indicated that weak biases can be amplified through repeated cultural transmission (Kirby et al., 2007). So, for example, structural language properties can emerge over time because languages come to reflect the cognitive constraints in the individuals that learn and produce the language. Similarly, we propose that languages may also reflect certain anatomical biases. Do sound systems adapt to the affordances of the articulation space induced by the vocal tract?
The human vocal tract has inherent nonlinearities which might derive from acoustics and aerodynamics (cf. quantal theory, see Stevens, 1989) or biomechanics (cf. Gick & Moisik, 2015). For instance, moving the tongue anteriorly along the hard palate to produce a fricative does not result in large changes in acoustics in most cases, but for a small range there is an abrupt change from a perceived palato-alveolar [ʃ] to alveolar [s] sound (Perkell, 2012). Nonlinearities such as these might bias all human speakers to converge on a very limited set of phonetic categories, and might even be a basis for combinatoriality or phonemic ‘universals’.
While IL typically uses discrete symbols, Verhoef et al. (2014) have used slide whistles to produce a continuous signal. We conducted an IL experiment with human subjects who communicated using a digital slide whistle for which the degree of nonlinearity is controlled. A single parameter (α) changes the mapping from slide whistle position (the ‘articulator’) to the acoustics. With α=0, the position of the slide whistle maps Bark-linearly to the acoustics. As α approaches 1, the mapping gets more double-sigmoidal, creating three plateaus where large ranges of positions map to similar frequencies. In more abstract terms, α represents the strength of a nonlinear (anatomical) bias in the vocal tract.
Six chains (138 participants) of dyads were tested, each chain with a different, fixed α. Participants had to communicate four meanings by producing a continuous signal using the slide-whistle in a ‘director-matcher’ game, alternating roles (cf. Garrod et al., 2007).
Results show that for high αs, subjects quickly converged on the plateaus. This quick convergence is indicative of a strong bias, repelling subjects away from unstable regions already within-subject. Furthermore, high αs lead to the emergence of signals that oscillate between two (out of three) plateaus. Because the sigmoidal spaces are spatially constrained, participants increasingly used the sequential/temporal dimension. As a result of this, the average duration of signals with high α was ~100ms longer than with low α. These oscillations could be an expression of a basis for phonemic combinatoriality.
We have shown that it is possible to manipulate the magnitude of an articulator-induced non-linear bias in a slide whistle IL framework. The results suggest that anatomical biases might indeed constrain the design space of language. In particular, the signaling systems in our study quickly converged (within-subject) on the use of stable regions. While these conclusions were drawn from experiments using slide whistles with a relatively strong bias, weaker biases could possibly be amplified over time by repeated cultural transmission, and likely lead to similar outcomes.

Abstract

Many factors have been proposed to explain why groups of people use different speech sounds in their language. These range from cultural, cognitive, environmental (e.g., Everett, et al., 2015) to anatomical (e.g., vocal tract (VT) morphology). How could such anatomical properties have led to the similarities and differences in speech sound distributions between human languages?

It is known that hard palate profile variation can induce different articulatory strategies in speakers (e.g., Brunner et al., 2009). That is, different hard palate profiles might induce a kind of bias on speech sound production, easing some types of sounds while impeding others. With a population of speakers (with a proportion of individuals) that share certain anatomical properties, even subtle VT biases might become expressed at a population-level (through e.g., bias amplification, Kirby et al., 2007). However, before we look into population-level effects, we should first look at within-individual anatomical factors. For that, we have developed a computer-simulated analogue for a human speaker: an agent. Our agent is designed to replicate speech sounds using a production and cognition module in a computationally tractable manner.

Previous agent models have often used more abstract (e.g., symbolic) signals. (e.g., Kirby et al., 2007). We have equipped our agent with a three-dimensional model of the VT (the production module, based on Birkholz, 2005) to which we made numerous adjustments. Specifically, we used a 4th-order Bezier curve that is able to capture hard palate variation on the mid-sagittal plane (XXX, 2015). Using an evolutionary algorithm, we were able to fit the model to human hard palate MRI tracings, yielding high accuracy fits and using as little as two parameters. Finally, we show that the samples map well-dispersed to the parameter-space, demonstrating that the model cannot generate unrealistic profiles. We can thus use this procedure to import palate measurements into our agent’s production module to investigate the effects on acoustics. We can also exaggerate/introduce novel biases.

Our agent is able to control the VT model using the cognition module.

Previous research has focused on detailed neurocomputation (e.g., Kröger et al., 2014) that highlights e.g., neurobiological principles or speech recognition performance. However, the brain is not the focus of our current study. Furthermore, present-day computing throughput likely does not allow for large-scale deployment of these architectures, as required by the population model we are developing. Thus, the question whether a very simple cognition module is able to replicate sounds in a computationally tractable manner, and even generalize over novel stimuli, is one worthy of attention in its own right.

Our agent’s cognition module is based on running an evolutionary algorithm on a large population of feed-forward neural networks (NNs). As such, (anatomical) bias strength can be thought of as an attractor basin area within the parameter-space the agent has to explore. The NN we used consists of a triple-layered (fully-connected), directed graph. The input layer (three neurons) receives the formants frequencies of a target-sound. The output layer (12 neurons) projects to the articulators in the production module. A hidden layer (seven neurons) enables the network to deal with nonlinear dependencies. The Euclidean distance (first three formants) between target and replication is used as fitness measure. Results show that sound replication is indeed possible, with Euclidean distance quickly approaching a close-to-zero asymptote.

Statistical analysis should reveal if the agent can also: a) Generalize: Can it replicate sounds not exposed to during learning? b) Replicate consistently: Do different, isolated agents always converge on the same sounds? c) Deal with consolidation: Can it still learn new sounds after an extended learning phase (‘infancy’) has been terminated? Finally, a comparison with more complex models will be used to demonstrate robustness.

Abstract

The present study describes how three now almost forgotten mid-20th-century logicians, the American Paul Jacoby and the Frenchmen Augustin Sesmat and Robert Blanché, all three ardent Catholics, tried to restore traditional predicate logic to a position of respectability by expanding the classic Square of Opposition to a hexagon of logical relations, showing the logical and cognitive advantages of such an expansion. The nature of these advantages is discussed in the context of modern research regarding the relations between logic, language, and cognition. It is desirable to call attention to these attempts, as they are, though almost totally forgotten, highly relevant against the backdrop of the clash between modern and traditional logic. It is argued that this clash was and is unnecessary, as both forms of predicate logic are legitimate, each in its own right. The attempts by Jacoby, Sesmat, and Blanché are, moreover, of interest to the history of logic in a cultural context in that, in their own idiosyncratic ways, they fit into the general pattern of the Catholic cultural revival that took place roughly between the years 1840 and 1960. The Catholic Church had put up stiff resistance to modern mathematical logic, considering it dehumanizing and a threat to Catholic doctrine. Both the wider cultural context and the specific implications for logic are described and analyzed, in conjunction with the more general philosophical and doctrinal issues involved.

Abstract

One debate in mathematical cognition centers on the single-representation model versus the two-representation model. Using an improved number Stroop paradigm (i.e., systematically manipulating physical size distance), in the present study we tested the predictions of the two models for number magnitude processing. The results supported the single-representation model and, more importantly, explained how a design problem (failure to manipulate physical size distance) and an analytical problem (failure to consider the interaction between congruity and task-irrelevant numerical distance) might have contributed to the evidence used to support the two-representation model. This study, therefore, can help settle the debate between the single-representation and two-representation models. © 2015 The Author(s)

Abstract

In this study, we use the association between various measures of the morphological family and decision latencies to reveal the way in which the components of Dutch and English compounds are processed. The results show that for constituents of concatenated compounds in both languages, a position-related token count of the morphological family plays a role, whereas English open compounds show an effect of a type count, similar to the effect of family size for simplex words. When Dutch compounds are written with an artificial space, they reveal no effect of type count, which shows that the differential effect for the English open compounds is not superficial. The final experiment provides converging evidence for the lexical consequences of the space in English compounds. Decision latencies for English simplex words are better predicted from counts of the morphological family that include concatenated and hyphenated but not open family members.

Abstract

Words can occur as constituents of other words. Some words have a high morphological productivity, in that they occur in many complex words, whereas others are morphological islands. Previous studies have found that the size of a word's morphological family can co-determine response latencies in lexical decision tasks. This thesis shows, using lexical decision as well as otherexperimental tasks, that the effect of family size is a semantic effect,reflecting the spreading of activation in the mental lexicon along the lines of morphological and semantic relatedness between words.

Abstract

We studied mutual influences between native and non-native vowel production during learning, i.e., before and after short-term visual articulatory feedback training with non-native sounds. Monolingual French speakers were trained to produce two non-native vowels: the Danish /ɔ/, which is similar to the French /o/, and the Russian /ɨ/, which is dissimilar from French vowels. We examined relationships between the production of French and non-native vowels before training, and the effects of training with non-native vowels on the production of French ones. We assessed for each participant the acoustic position and compactness of the trained vowels, and of the French /o/, /ø/, /y/ and /i/ vowels, which are acoustically closest to the trained vowels. Before training, the compactness of the French vowels was positively related to the accuracy and compactness in the production of non-native vowels. After training, French speakers’ accuracy and stability in the production of the two trained vowels improved on average by 19% and 37.5%, respectively. Interestingly, the production of native vowels was also affected by this learning process, with a drift towards non-native vowels. The amount of phonetic drift appears to depend on the degree of similarity between the native and non-native sounds.

Abstract

Pinpointing genes involved in non-right-handedness has the potential to clarify developmental contributions to human brain lateralization. Major-gene models have been considered for human handedness which allow for phenocopy and reduced penetrance, i.e. an imperfect correspondence between genotype and phenotype. However, a recent genome-wide association scan did not detect any common polymorphisms with substantial genetic effects. Previous linkage studies in families have also not yielded significant findings. Genetic heterogeneity and/or polygenicity are therefore indicated, but it remains possible that relatively rare, or even unique, major-genetic effects may be detectable in certain extended families with many non-right-handed members. Here we applied whole exome sequencing to 17 members from a single, large consanguineous family from Pakistan. Multipoint linkage analysis across all autosomes did not yield clear candidate genomic regions for involvement in the trait and single-point analysis of exomic variation did not yield clear candidate mutations/genes. Any genetic contribution to handedness in this unusual family is therefore likely to have a complex etiology, as at the population level.

Abstract

We describe a reaction time study in which listeners detected word or nonword syllable targets (e.g. zoo, trel) in sequences consisting of the target plus a consonant or syllable residue (trelsh, trelshek). The pattern of responses differed from an earlier word-spotting study with the same material, in which words were always harder to find if only a consonant residue remained. The earlier results should thus not be viewed in terms of syllabic parsing, but in terms of a universal role for syllables in speech perception; words which are accidentally present in spoken input (e.g. sell in self) can be rejected when they leave a residue of the input which could not itself be a word.

Abstract

Day-to-day interpretations of “space” are enmeshed in specific cultural and linguistic practices. For example, many cultures have an association between vertical height and social standing; more powerful people may be placed literally higher than others at social gatherings, and be spoken of as having higher status. This questionnaire is a guide for exploring relationships between space, language, and social structure. The goal is to better understand how space is organised in the focus community, and to investigate the extent to which space is used as a model for reproducing social forms.

Abstract

In Korean, focus is expressed in accentual phrasing. To ascertain whether words focused in this manner enjoy a processing advantage analogous to that conferred by focus as expressed in, e.g, English and Dutch, we devised sentences with target words in one of four conditions: prosodic focus, syntactic focus, prosodic + syntactic focus, and no focus as a control. 32 native speakers of Korean listened to blocks of 10 sentences, then were presented visually with words and asked whether or not they had heard them. Overall, words with focus were recognised significantly faster and more accurately than unfocused words. In addition, words with syntactic focus or syntactic + prosodic focus were recognised faster than words with prosodic focus alone. As for other languages, Korean focus confers processing advantage on the words carrying it. While prosodic focus does provide an advantage, however, syntactic focus appears to provide the greater beneficial effect for recognition memory

Abstract

In this paper we present a definition of Performance Grammar (PG), a psycholinguistically motivated syntax formalism, in declarative terms. PG aims not only at describing and explaining intuitive judgments and other data concerning the well–formedness of sentences of a language, but also at contributing to accounts of syntactic processing phenomena observable in language comprehension and language production. We highlight two general properties of human sentence generation, incrementality and late linearization,which make special demands on the design of grammar formalisms claiming psychological plausibility. In order to meet these demands, PG generates syntactic structures in a two-stage process. In the first and most important ‘hierarchical’ stage, unordered hierarchical structures (‘mobiles’) are assembled out of lexical building blocks. The key operation at work here is typed feature unification, which also delimits the positional options of the syntactic constituents in terms of so-called topological features. The second, much simpler stage takes care of arranging the branches of the mobile from left to right by ‘reading–out’ one positional option of every constituent. In this paper we concentrate on the structure assembly formalism in PG’s hierarchical component. We provide a declarative definition couched in an HPSG–style notation based on typed feature unification. Our emphasis throughout is on linear order constraints.

Abstract

Essays van psychologen en linguı̈sten over de relatie hersens-computers.

Abstract

Comments on a study by Frazier and others on Dutch-language lexical processing. Claims that the control condition in the experiment was inadequate and that an assumption made by Frazier about closed class verbal items is inaccurate, and proposes an alternative account of a subset of the data from the experiment

Abstract

Raises objections to L. Frazier et al's (see record 1994-32229-001) report of an experimental study intended to test Schreuder's (1990) Morphological Integration (MI) model concerning the processing of separable and inseparable verbs and shows that the logic of the experiment is flawed. The problem is rooted in the notion of a separable complex verb. The conclusion is drawn that Frazier et al's experimental data cannot be taken as evidence for the theoretical propositions they develop about the MI model.

Abstract

Four probe latency experiments show that the ‘constituent boundary effect’ (transitions between constituents are more difficult than within constituents) is a retrieval and not a storage phenomenon. The experimental logic used is called paraphrastic reproduction: after verbatim memorization of some sentences, subjects were instructed to reproduce them both in their original wording and in the form of sentences that, whilst preserving the original meaning, embodied different syntactic constructions. Syntactic constructions are defined as pairs which consist of a pattern of conceptual information and a syntactic scheme, i.e. a sequence of syntactic word categories and function words. For example, the sequence noun + finite intransitive main verb (‘John runs’) expresses a conceptual actor-action relationship. It is proposed that for each overlearned and simple syntactic construction there exists a retrieval plan which does the following. It searches through the long-term memory information that has been designated as the conceptual content of the utterance(s) to be produced, looking for a token of its conceptual pattern. The retrieved information is then cast into the format of its syntactic scheme. The organization of such plans is held responsible for the constituent boundary effect.

Abstract

In present-day spoken German, subordinate clauses introduced by the connector weil ‘because’ occur with two orders of subject, finite verb, and object(s). In addition to weil clauses with verb-final word order (“VF”; standard in subordinate clauses) one often hears weil clauses with SVO, the standard order of main clauses (“verb-second”, V2). The “weil-V2” phenomenon is restricted to sentences where the weil clause follows the main clause, and is virtually absent from formal (written, edited) German, occurring only in extemporaneous speech. Extant accounts of weil-V2 focus on the interpretation of weil-V2 clauses by the hearer, in particular on the type of discourse relation licensed by weil-V2 vs. weil-VF: causal/propositional or inferential/epistemic. Focusing instead on the production of weil clauses by the speaker, we examine a collection of about 1,000 sentences featuring a causal connector (weil, da or denn) after the main clause, all extracted from a corpus of spoken German dialogues and annotated with tags denoting major prosodic and syntactic boundaries, and various types of disfluencies (pauses, hesitations). Based on the observed frequency patterns and on known linguistic properties of the connectors, we propose that weil-V2 is caused by miscoordination between the mechanisms for lexical retrieval and grammatical encoding: Due to its high frequency, the lexical item weil is often selected prematurely, while the grammatical encoder is still working on the syntactic shape of the weil clause. Weil-V2 arises when pragmatic and processing factors drive the encoder to discontinue the current sentence, and to plan the clause following weil in the form of the main clause of an independent, new sentence. Thus, the speaker continues with a V2 clause, seemingly in violation of the VF constraint imposed by the preceding weil. We also explore implications of the model regarding the interpretation of sentences containing causal connectors.

Abstract

In this article, we examine methods that participants use to resolve troubles in the realization of practical courses of action. The concept of recruitment is developed to encompass the linguistic and embodied ways in which assistance may be sought – requested or solicited – or in which we come to perceive another’s need and offer or volunteer assistance. We argue that these methods are organized as a continuum, from explicit requests, to practices that elicit offers, to anticipations of need. We further identify a class of subsidiary actions that can precede recruitment and that publicly expose troubles and thereby create opportunities for others to assist. Data in American and British English.

Abstract

In their commentaries, both Heritage (2016/this issue) and Zinken and Rossi (2016/this issue) provide some context for our concept of and approach to recruitment in terms of previous research into requesting and offering. In doing so, they usefully consider what might be the boundaries of recruitmentwhat might be included and what might not be included or treated as recruitment. We respond here to their suggestions concerning these boundaries.

Abstract

Our analysis proceeds from the question that if grammar alone is insuffi- cient to identify the action of an imperative (e.g., offering, directing, warn- ing, begging, etc.), how can interlocutors come to recognize the specific action being performed by a given imperative? We argue that imperative directives that occur after the directed action could have first been rele- vantly performed explicitly to direct the actions of the recipient and tacitly treat the absence of the action as a failure for which the recipient is accountable. The tacit nature of the accountability orientation enables both parties to focus on restoring progressivity to the directed course of action rather than topicalizing a transgression. Data are from everyday interactions in British and American English.

Abstract

Children must possess some ability to process input in a meaningful manner to acquire language. The present study reports on data from an experiment investigating 3- to 5-year-old English-speaking children's understanding of restrictive relative clauses manipulated for embeddedness and focus. The results of the study showed that English-speaking children acquire right-branching before center-embedded structures. Comparisons made with data from Portuguese-speaking children suggest general-cognitive and language-specific constraints on development, and with respect to English, a “clause expansion” approach to processing in development

Abstract

Variability in children's language acquisition is likely due to a number of cognitive and social variables. The current study investigated whether individual differences in statistical learning (SL), which has been implicated in language acquisition, independently predicted 6- to 8-year-old's comprehension of syntax. Sixty-eight (N = 68) English-speaking children completed a test of comprehension of four syntactic structures, a test of SL utilizing nonlinguistic visual stimuli, and several additional control measures. The results revealed that SL independently predicted comprehension of two syntactic structures that show considerable variability in this age range: passives and object relative clauses. These data suggest that individual differences in children's capacity for SL are associated with the acquisition of the syntax of natural languages.

Abstract

Languages are strong markers of social identity. Multiple features of language and speech, from accent to lexis to grammatical constructions, mark speakers as members of specific cultural groups. In the current article, we present two confederate-scripted studies that investigated the social effects of the Australian hypocoristic use (e.g., uggie, uni, derro)—a lexical category emblematic of Australian culture. Participants took turns with a confederate directing each other through locations on a map. In their directions, the confederate used either hypocoristic (e.g., uni) or standard forms (e.g., university). The confederate’s cultural group membership and member prototypicality were manipulated by ethnic background and accent: In a highly prototypical in-group condition, the confederate had an Anglo-Celtic background and Australian English (AusE) accent; in a low prototypical in-group condition, the confederate had an Asian background and AusE accent; and in the out-group condition, the confederate had an Asian background and non-AusE accent. Hypocoristic use resulted in significantly higher participant-rated perceived common ground with the confederate when the confederate was an in-group but not an out-group member, which in some instances was moderated by in-group identification. The results suggest that like accents, culturally significant lexical categories function as markers of in-group identity, which influence perceived social closeness during interaction.

Abstract

This task investigates the expression of “enter” and “exit” events, and is a supplement to the Motion Elicitation task (https://doi.org/10.17617/2.3003391). Consultants are asked to describe a series of animated clips where a man moves into or out of a house. The clips focus on contrasts to do with perspective (e.g., whether the man appears to move away or towards the viewer) and transitional movement (e.g., whether the man walks or “teleports” into his new location).

Abstract

Do our hands 'speak the same language' across cultures? Gesture is the silent partner of spoken languages in face-to-face interaction, but we still have a lot to learn about gesture practices in different speech communities. The primary purpose of this task is to collect data in naturalistic settings that can be used to investigate the linguistic and cultural relativity of gesture performance, especially spatially indicative gestures. It involves video-recording pairs of speakers in both free conversation and more structured communication tasks (e.g., describing film plots).

Please note: the stimuli mentioned in this entry are available elsewhere: 'The Pear Story', a short film made at the University of California at Berkeley; "Frog, where are you?" from the original Mayer (1969) book, as published in the Appendix of Berman & Slobin (1994).

Abstract

It is generally assumed that verbs have an ‘argument structure’, which imposes various constraints on the noun phrases that can or must go with the verb, and an ‘event structure’, which characterises the particular temporal characteristics of the ‘event’ which the verb relates to: this event may be a state, a process, an activity, an ‘event in the narrow sense’, and others. In this paper, it is argued that that argument structure and event structure should be brought together. The lexical content of a verb assigns descriptive properties to one or more arguments at one or more times, hence verbs have an ‘argument time-structure’ (AT-structure). Numerous morphological and syntactical operations, such as participle formation or complex verb constructions, modify this AT-structure. This is illustrated with German recipient constructions such as ein Buch geschenkt bekommen or das Fenster geöffnet kriegen.

Abstract

Objectives: To investigate the time resolution of different methods for the computation of event-related desynchronization/synchronization (ERD/ERS), including one based on Hilbert transform. Methods: In order to better understand the time resolution of ERD/ERS, which is a function of factors such as the exact computation method, the frequency under study, the number of trials, and the sampling frequency, we simulated sudden changes in oscillation amplitude as well as very short and closely spaced events. Results: Hilbert-based ERD yields very similar results to ERD integrated over predefined time intervals (block ERD), if the block length is half the period length of the studied frequency. ERD predicts the onset of a change in oscillation amplitude with an error margin of only 10–30 ms. On the other hand, the time the ERD response needs to climb to its full height after a sudden change in oscillation amplitude is quite long, i.e. between 200 and 500 ms. With respect to sensitivity to short oscillatory events, the ratio between sampling frequency and electroencephalographic frequency band plays a major role. Conclusions: (1) The optimal time interval for the computation of block ERD is half a period of the frequency under investigation. (2) Due to the slow impulse response, amplitude effects in the ERD may in reality be caused by duration differences. (3) Although ERD based on the Hilbert transform does not yield any significant advantages over classical ERD in terms of time resolution, it has some important practical advantages.

Abstract

This study investigates the effect of speech rate on spoken word recognition across the adult life span. Contrary to previous studies, conversational materials with a natural variation in speech rate were used rather than lab-recorded stimuli that are subsequently artificially time-compressed. It was investigated whether older adults' speech recognition is more adversely affected by increased speech rate compared to younger and middle-aged adults, and which individual listener characteristics (e.g., hearing, fluid cognitive processing ability) predict the size of the speech rate effect on recognition performance. In an eye-tracking experiment, participants indicated with a mouse-click which visually presented words they recognized in a conversational fragment. Click response times, gaze, and pupil size data were analyzed. As expected, click response times and gaze behavior were affected by speech rate, indicating that word recognition is more difficult if speech rate is faster. Contrary to earlier findings, increased speech rate affected the age groups to the same extent. Fluid cognitive processing ability predicted general recognition performance, but did not modulate the speech rate effect. These findings emphasize that earlier results of age by speech rate interactions mainly obtained with artificially speeded materials may not generalize to speech rate variation as encountered in conversational speech.

Abstract

The Acceptable Noise Level (ANL) test, in which individuals indicate what level of noise they are willing to put up with while following speech, has been used to guide hearing aid fitting decisions and has been found to relate to prospective hearing aid use. Unlike objective measures of speech perception ability, ANL outcome is not related to individual hearing loss or age, but rather reflects an individual's inherent acceptance of competing noise while listening to speech. As such, the measure may predict aspects of hearing aid success. Crucially, however, recent studies have questioned its repeatability (test-retest reliability). The first question for this study was whether the inconsistent results regarding the repeatability of the ANL test may be due to differences in speech material types used in previous studies. Second, it is unclear whether meaningfulness and semantic coherence of the speech modify ANL outcome. To investigate these questions, we compared ANLs obtained with three types of materials: the International Speech Test Signal (ISTS), which is non-meaningful and semantically non-coherent by definition, passages consisting of concatenated meaningful standard audiology sentences, and longer fragments taken from conversational speech. We included conversational speech as this type of speech material is most representative of everyday listening. Additionally, we investigated whether ANL outcomes, obtained with these three different speech materials, were associated with self-reported limitations due to hearing problems and listening effort in everyday life, as assessed by a questionnaire. ANL data were collected for 57 relatively good-hearing adult participants with an age range representative for hearing aid users. Results showed that meaningfulness, but not semantic coherence of the speech material affected ANL. Less noise was accepted for the non-meaningful ISTS signal than for the meaningful speech materials. ANL repeatability was comparable across the speech materials. Furthermore, ANL was found to be associated with the outcome of a hearing-related questionnaire. This suggests that ANL may predict activity limitations for listening to speech-in-noise in everyday situations. In conclusion, more natural speech materials can be used in a clinical setting as their repeatability is not reduced compared to more standard materials.

Abstract

A steady accumulation of experimental data argues that protein synthesis in neurons is not merely restricted to the somatic compartment, but also occurs in several discrete cellular micro-domains. Local protein synthesis is critical for the establishment of synaptic plasticity in mature dendrites and in directing the growth cones of immature axons, and has been associated with cognitive impairment in mice and humans. Although in recent years a number of important mechanisms governing this process have been described, it remains technically challenging to precisely monitor local protein synthesis in individual neuronal cell parts independent from the soma. This report presents the utility of employing microfluidic chambers for the isolation and treatment of single neuronal cellular compartments. Furthermore, it is demonstrated that a protein synthesis assay, based on fluorescent non-canonical amino acid tagging (FUNCAT), can be combined with this cell culture system to label nascent proteins within a discrete structural and functional domain of the neuron. Together, these techniques could be employed for the detection of protein synthesis within developing and mature neurites, offering an effective approach to elucidate novel mechanisms controlling synaptic maintenance and plasticity.

Abstract

During speech listening, the brain parses a continuous acoustic stream of information into computational units (e.g. syllables or words) necessary for speech comprehension. Recent neuroscientific hypotheses propose that neural oscillations contribute to speech parsing, but whether they do so on the basis of acoustic cues (bottom-up acoustic parsing) or as a function of available linguistic representations (top-down linguistic parsing) is unknown. In this magnetoencephalography study, we contrasted acoustic and linguistic parsing using bistable speech sequences. While listening to the speech sequences, participants were asked to maintain one of the two possible speech percepts through volitional control. We predicted that the tracking of speech dynamics by neural oscillations would not only follow the acoustic properties but also shift in time according to the participant’s conscious speech percept. Our results show that the latency of high-frequency activity (specifically, beta and gamma bands) varied as a function of the perceptual report. In contrast, the phase of low-frequency oscillations was not strongly affected by top-down control. While changes in low-frequency neural oscillations were compatible with the encoding of pre-lexical segmentation cues, high-frequency activity specifically informed on an individual’s conscious speech percept.

Abstract

Coronary Artery Disease (CAD) remains the leading cause of mortality worldwide. Mortality rates associated with CAD have shown an exceptional increase particularly in fast developing economies like the Kingdom of Saudi Arabia (KSA). Over the past twenty years, CAD has become the leading cause of death in KSA and has reached epidemic proportions. This rise is undoubtedly caused by fast urbanization that is associated with a life-style that promotes CAD. However, the question remains whether genetics play a significant role and whether genetic susceptibility is increased in KSA compared to the well-studied Western European populations. Therefore, we performed an Exome-wide association study (EWAS) in 832 patients and 1,076 controls of Saudi Arabian origin to test whether population specific, strong genetic risk factors for CAD exist, or whether the polygenic risk score for known genetic risk factors for CAD, lipids, and Type 2 Diabetes show evidence for an enriched genetic burden. Our results do not show significant associations for a single genetic locus. However, the heritability estimate for CAD for this population was high (h2 = 0.53, S.E. = 0.1, p = 4e-12) and we observed a significant association of the polygenic risk score for CAD that demonstrates that the population of KSA, at least in part, shares the genetic risk associated to CAD in Western populations.

Abstract

Background Many genes are candidates for involvement in epileptic encephalopathy (EE) because one or a few possibly pathogenic variants have been found in patients, but insufficient genetic or functional evidence exists for a definite annotation. Methods To increase the number of validated EE genes, we sequenced 26 known and 351 candidate genes for EE in 360 patients. Variants in 25 genes known to be involved in EE or related phenotypes were followed up in 41 patients. We pri- oritized the candidate genes, and followed up 31 variants in this prioritized subset of candidate genes. Results Twenty-nine genotypes in known genes for EE (19) or related diseases (10), dominant as well as recessive or X-linked, were classified as likely pathogenic variants. Among those, likely pathogenic de novo variants were found in EE genes that act dominantly, including the recently identified genes EEF1A2, KCNB1 and the X-linked gene IQSEC2 .A de novo frameshift variant in candi- date gene HNRNPU was the only de novo variant found among the followed- up candidate genes, and the patient’s phenotype was similar to a few recent publication